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Schedule
Wednesday June 30th
8.30-8.50: Opening of the Scientific Days 2021 edition 8.50: Welcome of the participants on Zoom 9:00: Welcome by the ED EGAAL Director 9:10-9:25: Explanation of the course of the days / Getting to grips with Zoom 9:25-9:30: Distribution of participants in the rooms 9:35-10:50: Oral presentations n°1 (4 parallel sessions: O1S1, O1S2, O1S3, O1S4) 10.50-11.00: Coffee break 11-11:45: Poster presentations (1 plenary session: PS1) 11:45-13:30: Lunch break 13:30-13:45: Welcome of the participants on Zoom 13:45-14:45: Plenary conference - Speech by Maja Ilić 14:45-14:50: Distribution in the rooms 15-16:45: Oral presentations n°2 (4 parallel sessions: O2S1, O2S2, O2S3, O2S4) 16:45-17:00: Coffee break 17:00-17:45: Poster presentations (1 plenary session: PS2) 17:45-18:00: End of the day – Schedule of day 2
Thursday July 1st
8:30-8:55: Welcome of participants on Zoom 8:55-9:00: Distribution in the rooms 9:00-11:00: Oral presentations n°3 (4 parallel sessions: O3S1, O3S2, O3S3, O3S4) 11:00-11:15: Coffee break 11:15-11:55: Poster presentations (1 plenary session: PS3) 11:55-13:30: Lunch break 13:30-13:45: Welcome of the participants on Zoom 13:45-14:45: Plenary conference - Speech by Jeanne Ropars 14:45-14:50: Coffee break 14:50-15:30: Poster presentations (1 plenary session: PS4) 15:35-15:45: Coffee break / Prize deliberation 15:45-16:45: Plenary conference - Speech by Stéphane Le Mouélic 16:50: Awards ceremony - Conclusion of the Scientific Days 2021
JS Organizing Comittee
Nabil ABAAB Léa MOUNIER PhD Student PhD Student Le Mans Université– France Univeristé de Rennes 1 Université de Gabès – Tunisia
Marie BELAIR Elisa NEVES PhD Student PhD Student Université de Bretagne Occidentale Université de Rennes 1
Valentine BOUJU Stéphane PERRIER PhD Student PhD Student Université de Rennes 1 Université d’Angers
Maryse CHARPENTIER NOYER Mathilde PETITPAS PhD Student PhD Student Université de Nantes Agrocampus Ouest
Julie LEGROS Louisa RAMAROSON PhD Student PhD Student Agrocampus Ouest Université d’Angers
Nathan MARTIN Nolwenn ROLLAND PhD Student PhD Student Le Mans Université Université de Bretagne Occidentale
Solène MAUGER Margot WAGNER PhD Student PhD Student Université de Rennes 1 Agrocampus Ouest
Table of contents Oral Presentation 1 (O1) – 30th June ...... 1 Session 1 (O1S1) ...... 1 Prediction of magnetite (Fe3O4) nanoparticles transformation to maghemite (Fe2O3) in aqueous solutions ...... 2 Effect of Heat Stress and Feeding Management on Growth and Physiological Responses of Finishing Pigs ...... 3 Analyzing Free JAR data by combining lexical preprocessing and machine learning strategies .... 4
How to enhance N2 fixation and N accumulation in oilseed rape-service plant mixtures intercropping? ...... 5 Phylogenetic isolation of host-trees reduces resource tracking by herbivorous insects and their parasitoids ...... 6 Oral Presentation 1 (O1) – 30th June ...... 7 Session 2 (O1S2) ...... 7 Functional and molecular characterization of Anopheles gambiae muscarinic receptors ...... 8 Study of fresh cheese volatile compound release while chewing and influence of aroma molecule equilibrium on flavour perception ...... 9 Effects of macrophytes on lentic macroinvertebrate assemblage and implications for water management ...... 10 Geologically recent earthflow-like landslides on Mars ...... 11 Impact of temperature and concentration of four surface disinfectants on spoilage mold dry spores ...... 12 Oral Presentation 1 (O1) – 30th June ...... 13 Session 3 (O1S3) ...... 13 Design of a participatory approach with consumers and winegrowers for the deployment of more respectful practices in the vineyard: a case study within the Cabernet d’Anjou ...... 14 Organic agriculture and hedgerows uphold endospheric wheat microbiota at field and landscape scale...... 15 Flavonoids and resistance of the carrot (Daucus carota) to Alternaria dauci ...... 16 Landscape structure influences grassland productivity through changes in plant functional diversity...... 17 An overview of Pickering nanoemulsions: manufacturing processes, formulation and applications ...... 18 Oral Presentation 1 (O1) – 30th June ...... 19 Session 4 (O1S4) ...... 19
Organic dairy calves reared with nurse cows and their impacts on Cryptosporidium infection ...... 20 Bioavailability of amino acids, especially of tryptophan, in human milk and infant formulas .... 21 Disentanglign the effects of farming intensity and semi natural habitats ar deifferent spatial scales on multifonctionality including both ecological and socio economic functions ...... 22 Development of a new plant protection strategy through the screening and formulation of plant extracts active on the adaptative mechanisms of fungal plant pathogens ...... 23 Biomimetic semi-permeable vesicles as microreactors to modulate the phase behaviour of macromolecules ...... 24 Posters Presentation 1 (PS1) – 30th June ...... 25 Size fractionation highlights the mobility of copper from urban stormwater to river ...... 26 The rheological properties of rennet gels depend on the divalent cation distribution in the casein micelles ...... 27 Hydrogeological controls on stream discharge dynamics in bedrock catchments: exploring the combined effects of seepage development and heterogeneity ...... 28 Elaboration of innovative multi-layered materials based on functionalized α-glucans ...... 29 Realistic model for Environmental NanoPlastics (ENPs) ...... 30 Biomarkers of seed quality using isotope assisted metabolomics in Medicago truncatula ...... 31 Investigating the origin of soft cheeses color defect ...... 32 Developing a multihost African swine fever transmission model at the domestic-wildlife interface ...... 33 Effect of abiotic factors and culture media on the growth of cheese- associated Nectriaceae spp...... 34 Oral Presentation 2 (O2) – 30th June ...... 35 Session 1 (O2S1) ...... 35 Helium Charge Transfer Dissociation: an emerging fragmentation method Applied for a better understanding of the structure-function relationships in carrageenans ...... 36 Successive inoculations of pigs with porcine reproductive and respiratory syndrome virus and swine influenza A virus result in a two-way interference between both infections ...... 37 Assessing the impacts of hydromorphological restoration in headwater streams ...... 38 Skin formation in drying droplets of dairy proteins ...... 39 Contribution of earthworm bioturbation to the structure of engineered soils ...... 40 Genetic variability of nesting behavior and egg production traits for laying hens raised in a cage- free system ...... 41 A novel mediator of rhizospheric plant-microbe interactions: microRNAs ...... 42 Oral Presentation 2 (O2) – 30th June ...... 43
Session 2 (O2S2) ...... 43 Environnemental assessment of contrasted organic vegetable farms in France ...... 44 Positive interactions between lactic acid bacteria promoted by nitrogen-based nutritional dependencies ...... 45 Rift Valley fever hosts are not equal – Modelling infectiousness at the individual level ...... 46 Transport and reactivity of dissolved oxygen in fractured- bedrock aquifers ...... 47 Role of nitrogen in the plant-fungal pathogen interaction during seedling establishment ...... 48 Sequential natural deep eutectic solvents pretreatment/water extraction: a novel way to extract and select pectin according to its main structural domain ...... 49 Decrypting the mechanisms of host recognition and acceptance by a phytophagous insect ...... 50 Oral Presentation 2 (O2) – 30th June ...... 51 Session 3 (O2S3) ...... 51 Modeling plant-soil systems using Structural Equation Models ...... 52 Synoptic 3D landslide volume calculation from repeat LiDAR data ...... 53 SCOOP12 moderates cell elongation by controlling ROS homeostasis and promotes plant defenses through a wide transcriptional impact in Arabidopsis ...... 54 Effect of the distance from trophic resources provided to parasitoids on the regulation of aphid pests in a plum-tree orchard in Chile ...... 55 Estimation of crossbreed beef half-carcass chemical composition by dual-energy X-ray absorptiometry (DXA) scan of half-carcass or 11th rib ...... 56 Molecular networking of tandem ion mobility data and its implications for glycomics ...... 57 Exploiting favourable alleles in apple genetic resources using genomic selection ...... 58 Oral Presentation 2 (O2) – 30th June ...... 59 Session 4 (O2S4) ...... 59 Effects of acid environment on digestate and reconstituted ration in a batch hydrolysis/acidogenic reactor ...... 60 Single seed microbiota: dynamics and transmission from mother plant to seedling ...... 61 CAKERS – Cake reduced in sugar sweet and sour...... 62 Specialized metabolism in Brassica napus: a multi-omic approach for the characterization of phytochemical diversity, its genetic determinants and its regulation by pathogen infection ...... 63 ...... 64 Coastal sand dune monitoring using hyperspectral and full-waveform LiDAR synchronized remote sensing: low vegetation cover classification and digital terrain model improvement ...... 64
In-depth analysis of the flax fibre intricate microstructure in relationship with ist mechanical behaviour...... 65 Posters Presentation 2 (PS2) – 30th June ...... 66 Nanoplastics' Behavior in Polar Waters: Modeling the Interface between Saltwater and Sea Ice 67 Multicriteria definition of small-scale biorefineries based on a statistical classification ...... 68 Screening and investigating starch structure and enzymatic degradability in a wheat MAGIC population ...... 69 Understanding the compensatory mechanisms in resistant Anopheles gambiae AcerKis and KdrKis neurons is essential to adapt insecticide-based mosquito control ...... 70 A Specific Rhizomicrobiome Selected by a Long-lived Endemic Plant in the Sub-Antarctic Kerguelen Islands ...... 71 Sedimentary breccias: a marker of lithospheric extension? ...... 72 The drivers of vine-plant root microbiota endosphere composition include both abiotic and plant- specific factors ...... 73 Origin of the gypsum veins associated with the early Cretaceous Bouhedma formation, Northern Chotts range, Southern Tunisia ...... 74 Omics metrics for ecological niche potential and metabolic interactions ...... 75 Oral Presentation 3 (O3) – 1st July ...... 76 Session 1 (O3S1) ...... 76 The impact of housing conditions on porcine adult stem cell populations differ between adipose tissue and skeletal muscle ...... 77 Understanding the resistance mechanisms of the white mustard (Sinapis alba) to the pollen beetle (Brassicogethes aeneus) ...... 78 Carbon and dry matter losses during composting of date palm residues with rock phosphate and sheep manure as additives ...... 79 Simplified spectrophotometric acid-base titrations to assess organic matter reactivity ...... 80 Inability of natural mutant population of aphids to switch their reproductive mode is probably due to alteration of genetics programs required for sexual embryogenesis...... 81 The importance of tertiary roots in young peas for future service legume selection ...... 82 Recurring Campylobacter jejuni lineages causing human infection in Luxembourg and revealed by Whole Genome Sequencing ...... 83 Oral Presentation 3 (O3) – 1st July ...... 84 Session 2 (O3S2) ...... 84 Microwave Coagulable Alveolar Foams ...... 85
Formation of subglacial triangular-shaped bedforms: indicators of hydrological changes during ice sheet retreats ...... 86 Statistical modelling of in vitro pepsinolysis using peptidomic data ...... 87 Three is bigger than two and four: impact of the ploidy level on the recombination landscape in Brassica...... 88 In vitro incorporation of fat-soluble vitamins in mixed bile assemblies ...... 89 Quantification and modeling of the climatic services provided by trees in a canyon street ...... 90 Soil aggregate stability dynamics of an agricultural silt soil following application of different digestates ...... 91 Oral Presentation 3 (O3) – 1st July ...... 92 Session 3 (O3S3) ...... 92 High-resolution study of the Middle Eocene deposits of the Paris Basin ...... 93 Three Oilseed rape soil microorganisms promote the establishment of parasitic plant Phelipanche ramose on host plant Brassica napus...... 94 Development of new typing tools for Clostridium botulinum group III strains responsible for animal botulism outbreaks ...... 95 Apple trees in garden-orchard systems improve soil quality and yield of organic radish crop ..... 96 Rheological properties of lactoferrin/β-lactoglobulin complex coacervates ...... 97 Individualization of flax tows promoted by physical pre-treatments: Impact on mechanical properties of a flax/PLA non-woven composite ...... 98 Functional characterization of BnD22 a Brassica napus PI- WSCPs “Protease Inhibitors-Water Soluble Chlorophyll binding Proteins” ...... 99 Plasma Amino Acid and Metabolite Profiles of Adult and Growing Pigs after Feeding a Diet with Hydrolysed Feather Meal with a Balanced or Unbalanced Amino Acid Profile ...... 100 Oral Presentation 3 (O3) – 1st July ...... 101 Session 4 (O3S4) ...... 101 Apple agglutinins (MdAGGs), a new mechanism of resistance against ...... 102 Energy-efficient superconcentration-granulation based process to manufacture dairy powders: 103 P and Fe speciation in pre-precipitated sewage sludge: Effect of iron salts' type and concentration ...... 104 Multi-agent, multi-level modelling of PRRSv transmission in highly structured farms ...... 105 Fossil inclusions in amber, a window to the past: The study of Miocene Ethiopian amber (Africa) ...... 106 Immune priming and the limited diversity of resistance genes in host mixtures...... 107
Effects of self-produced compost and biochar amendments on mobility and uptake of metals and metalloids in moderately contaminated soil of an allotment garden ...... 108 Posters Presentation 3 (PS3) – 1st July ...... 109 Does encapsulation of DHA with heat-denatured whey proteins in Pickering emulsions improve its bioaccessibility? ...... 110 Vulnerability of coastal areas to increased aquifer saturation due to climate change ...... 111 Role of microRNAs in the photo-control of bud burst in Rosa ‘Radrazz’ ...... 112 Long-term changes in marine growth modulates maturation schedule in Atlantic salmon ...... 113 Evaluation of three short-range (0-6h) rain ensemble ... forecasts: study of the Aude October 2018 flash floods (southeastern France) 114 Does your origin determines your fate: a tale of gene duplication in Rosaceae ...... 115 Impact of iron oxide nanoparticles on Pb leaching and phytoextraction by Helianthus annuus . 116 Spatial variability and changes in storage-discharge relationships of crystalline catchments: implications for resilience and water resources management of Rennes area ...... 117 Posters Presentation 4 (PS4) – 1st July ...... 118 The particle shape of peats: a complementary analysis for their characterization ...... 119 Pepsin hydrolysis is possible from pH 5 to pH 2 on caseins, contrarely to egg-white proteins and the hemoglobin standard of activity measurements...... 120 Plastic debris distribution and behaviour in soil: new key insights from a household wastes- contaminated soil...... 121 How to explain QTL imbalance between ohnologous chromosomes in apple ? ...... 122 Exploration of the potential for biosurfactant production by fungi from oil-contaminated environments ...... 123 Survival of Campylobacter jeuni cocultured with Salmonella spp. in aerobic condition ...... 124 Performance of automated methods for flash flood inundation mapping: a comparison of a DTM filling and two hydrodynamic methods ...... 125 Tidal dissipation in Io and Europa’s silicate mantle: Influence of a partially molten layer ...... 126 Schedule - 30th June ...... 127 Schedule -1st July 2021 ...... 131
Oral Presentation 1 (O1) – 30th June
Session 1 (O1S1)
Prediction of magnetite (Fe3O4) nanoparticles transformation to maghemite (Fe2O3) in aqueous solutions
a* a b c a Phoomipat Jungcharoen , Mathieu Pédrot , Frank Heberling , Fadi Choueikani , Rémi Marsac
a*UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France b Karlsruhe Institute of Technology, Institut für Nukleare Entsorgung, P.O. Box 3640, D-76021 Karlsruhe, Germany cSynchrotron SOLEIL, L'ormes des Merisiers, Saint Aubin BP48, 91192 Gif sur Yvette cedex, France Keywords: geoscience, solubility, nanoparticle Abstract: Magnetite (Fe3O4) nanoparticle, which is ubiquitous in subsurface and highly sensitive to various environmental conditions, is of great scientific interest due to its magnetic, optic, semiconductor, and redox properties. Magnetite contains one Fe(II) and two Fe(III) in its structure (R = Fe(II)/Fe(III) = 0.5) and many of its interesting properties are due to the presence of Fe(II). However, Fe(II) can be easily (under air) oxidized to Fe(III), which leads to the formation of maghemite (γ-Fe2O3) (R = 0). This transformation is complex because magnetite and maghemite form a solid solution, that is, a continuum of intermediate compounds so-called non-stoichiometric magnetite (Fe3-xO4) can form with 0 < R < 0.5. In addition, while Fe(III) is poorly soluble, Fe(II) can be dissolved in highly acidic conditions:
Fe3O4 + 2 H+ ⇌ Fe2O3 + H2O + Fe2+
Although several studies focused on the impact of R on magnetite reactivity, no investigation of the impact of pH on magnetite transformation to maghemite has been performed under environmentally relevant conditions. Currently, experimental studies are conducted over a large pH range (3-11) in 10 mM NaCl solution under anaerobic condition, assuming that magnetite stoichiometry remains the same as the synthesized (pristine) one. The present study demonstrates that R is strongly affected by pH and redox conditions. Stoichiometric nano-magnetite (≈10 nm) cannot not exist at moderately acidic pH (< 7) despite a high magnetite concentration (2.5 g/L) or an excess amount of 2500 µM dissolved Fe(II). These findings might question mechanistic interpretations of magnetite physico-chemical behavior in many studies: in such conditions, nano-magnetites suspensions are no more than quasi-maghemite ones with dissolved Fe2+. We also showed that Fe2+ amendment can recharge maghemite to magnetite at pH > 7. All data were then used to develop a predictive model of the effect of pH, concentration, magnetite and maghemite mixtures, and dissolved Fe (II) addition. This study indicates that magnetite stoichiometry should be carefully monitored for appropriate applications such as environmental treatment, groundwater remediation, biomedical process, and catalysis.
2
Effect of Heat Stress and Feeding Management on Growth and Physiological Responses of Finishing Pigs
Aira Maye Servientoa,b,*, Etienne Labussièrea, Mathieu Castexb, David Renaudeaua aPEGASE, INRAE, Institut Agro, 35590 Saint-Gilles, France bLallemand SAS, 19 rue des Briquetiers, BP59, 31702 Blagnac, France *Presenting PhD student
Keywords: heat stress, pigs, alimentation
Abstract: The objective of the study was to determine whether heat stress (HS) effects in pigs were caused directly by heat exposure (regardless of feeding level and pattern) or indirectly due to the reduction of feed intake, and to determine if splitting heat increments via increasing feeding frequency can improve pig response to HS. A total of 48 female pigs (66.1 ± 1.7 kg) were allotted to 4 groups in 3 replicates. After 7 d in thermoneutral conditions (TN; 22°C; P1), pigs were placed in either TN or HS (32°C) conditions for 20 d (P2). The diet was provided either ad libitum (AL; 2 distributions/d) or pair-fed (PF8; 8 distributions/d) using HS-AL pigs as the reference group. Thus, the 4 experimental groups were TN-AL, HS-AL, TN-PF8, and HS-PF8. Daily ration of PF8 pigs was distributed at every 90-min intervals from 09h00 to 19h30. Data was analyzed using the PROC MIXED procedure with replicate (n=3), experimental group (n=4), and their interactions as fixed effects and the REPEATED statement was used to for repeated measures data. Pigs had similar ADFI during P1 (P>0.05), while HS- AL and PF8 pigs had lower ADFI (-19%), ADG (-25%), and final BW (-6.1 kg) than TN-AL pigs (P<0.01) during P2. TN-AL pigs had thicker backfat than TN-PF8 pigs (P<0.05) while the HS pigs had intermediate results. HS pigs had higher perirenal fat percentage based on the contrast analysis between PF8 pigs (P<0.05). Thermoregulatory responses of pigs increased with HS exposure but did not differ between HS nor between TN groups (P>0.05). Muscle temperature (Tmuscle) variation depended on feeding and physical activity for TN pigs while Tmuscle gradually increased throughout the day for HS pigs. Increase in Tmuscle for each meal was lower in HS-PF8 than TN-PF8 (P<0.05). Exposure to HS decreased plasma T3 and T4 (P<0.05), and increased plasma creatinine (P<0.05). Between the PF8 groups, HS pigs also had a transient increase in plasma insulin on d 8 (P<0.05). The effect of HS on feed intake decreased growth rate of pigs but there are heat-induced effects such as altered physiological responses which might explain direct HS effects seen in other literature especially in terms of increased adiposity. The increased feed provision frequency in the present study did not improve HS response of pigs.
3
Analyzing Free JAR data by combining lexical preprocessing and machine learning strategies
Alexiane Lucabc*, Sébastien Lêc, Mathilde Philippeb, El Mostafa Qannaria, Evelyne Vigneaua (* = presenting PhD student, subsequent authors optional) a Laboratoire StatSC, ONIRIS, Rue de la Géraudière, 44300 Nantes, France b Strategir, 5 rue Foy, 33000 Bordeaux, France c Laboratoire de Mathématiques appliquées, Agrocampus Ouest, 65 rue de Saint Brieuc, 35000 Rennes, France
Keywords: Alimentation; sensory data analysis; Natural Language Processing
Abstract: Sensory protocols used for product characterization have considerably changed over the past two decades. Profiling methods such as QDA (Stone et al. 1974) or the Spectrum procedure (Meilgaard, Civille, and Carr 2007), which highlight sensory perceptions in a precise way with the use of trained panels, were hitherto very popular. However, they have become less and less flexible in a changing sensory world, in favor of more adaptable and fast methods, more suitable to the new issues and constraints. The Free JAR procedure (Luc, Lê, and Philippe 2020) is one of them: consumers are, firstly, invited to sort the products into three hedonic categories and, secondly, to describe the products using their own attributes, but based on a JAR structuration. This means that they are encouraged to use the terms “too much”, “just about right”, “not enough” or equivalent structure. By so doing, the aim is to get the consumers elicit the products’ assets and weaknesses. The data analysis focuses on expressing consumers’ assessments into valency scores that reflect the positive or negative aspects associated with the products. Natural Language Processing (NLP) methods could help us achieve this goal. In particular, two NLP approaches are considered herein. While the lexical approach focusses on the meaning given to words, the machine learning approach aims to understand the link between the words used to describe the products and the hedonic categorization, without heavy data preprocessing. However, in sensory evaluation, surveys generally yield data with a few hundred comments: this is insufficient to run robust machine learning algorithms and, by contrast, it may be too excessive for a lexical approach, where all the comments have to be studied one by one. In this presentation, a hybrid approach is explored to overcome this issue. In particular, investigations will be carried out in order to strike a proper balance between algorithms automation and lexical preprocessing, which aims to improve the performance of the analysis approach.
4
How to enhance N2 fixation and N accumulation in oilseed rape-service plant mixtures intercropping?
Xavier Bousselina, b, *, Alice Bauxb, Muriel Valantin-Morisonc, Mathieu Lorina, Nathalie Cassagnea, Joëlle Fusteca a USC 1432 LEVA, Ecole Supérieure d’Agricultures, INRAE, SFR 4207 QUASAV, 55 rue Rabelais, 49100 Angers, France b Agroscope, Plants and plants products, Route de Duillier 50, 1260 Nyon, Switzerland c UMR Agronomie, INRAE, AgroParisTech, Université Paris-Saclay, 78850, Thiverval-Grignon, France
Keywords: Agronomy, agroecology, intercropping
Abstract: Swiss farmers often grow winter oilseed rape (Brassica napus L.) intercropped with frost sensitive service plant mixtures. It represented about 10 % of the 25 000 ha of oilseed rape sown in Switzerland in 2020. This service plants are mostly used in order to compete against weeds and avoid the use of herbicide (Baux and Schumacher 2019 ; Lorin et al. 2015). Moreover, they are also known to provide nitrogen to oilseed rape in spring and could allow a reduction of the use of nitrogen fertilization of up to 30 to 40 kg per hectare (Lorin et al. 2016 ; Verret et al. 2017). A greenhouse and a field experiments were undertaken in order to assess the capacity of different service plant mixtures to accumulate and fix nitrogen. The legumes currently used in service plant mixtures intercropped with oilseed rape were not similar in terms of nitrogen accumulation and fixation potential. These experiments showed the high potential of fixation of both faba bean (Vicia faba L.) and Berseem clover (Trifolium alexandrinum L.) either intercropped alone with oilseed rape, or in more complex mixtures. The grass pea (Lathyrus sativus L.) biomass was badly affected by competition with oilseed rape resulting in low N accumulation and fixation. Both in greenhouse and field experiments, the completion with oilseed rape did increase the proportion of nitrogen coming from symbiotic N2 fixation (%Ndfa) of legumes. The addition of a non-legume service plant, the niger (Guizotia abyssinica (L.f.)), to legume-oilseed rape intercropping did not further increase the legumes %Ndfa. Finally, even if non-legumes such as niger are good competitors against weeds, these species are not positively contributing to nitrogen accumulation in the service plant mixtures compared to pure legumes.
Baux and Schumacher, 2019. Rech. Agron. Suisse. 10, 128-133. Lorin et al., 2015. Eur. J. Agron. 71, 96-105 Lorin et al., 2016. Field Crops Res. 193, 24-33 Verret et al., 2017. Eur. J. Agron. 91, 93-103
5
Phylogenetic isolation of host-trees reduces resource tracking by herbivorous insects and their parasitoids
Soumen Mallicka*, Freerk Mollemanb, Benjamin Yguela,c, Richard Baileya,d, Jörg Müllere,f, Thomas Cahona, Frédéric Jeana and Andreas Prinzinga a* Centre National de la Recherche Scientifique, Research Unit UMR 6553, Ecosystèmes Biodiversité Evolution (ECOBIO), Université de Rennes 1, Campus de Beaulieu, 35042 Rennes, France. b Department of Systematic Zoology, Institute of Environmental Biology, Faculty of Biology, A. Mickiewicz University, Ul. Uniwersytetu Poznańskiego 6, PL-61-614 Poznań, Poland c (present address) Centre d’Ecologie et des Sciences de la Conservation (CESCO-UMR 7204), Sorbonne Universités-MNHN- CNRS-UPMC, CP51, 55-61rue Buffon, Paris, 75005, France d (present address) Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Ło´dź, Lodz, Poland e Field Station Fabrikschleichach, Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Glashüttenstraße 5, 96181 Rauhenebrach, Germany f Bavarian Forest National Park, Freyunger Str. 2, 94481 Grafenau, Germany
Keywords: Ecology, Resource tracking, Insect herbivore
Abstract: Parasites use movements and sensory capabilities in foraging strategies that enable them to track host-resources. Such resource tracking may be limited by spatial isolation of hosts due to limited movements and sensory information. However, even spatially proximate hosts can be difficult to track. We hypothesise that when host-trees in a forest are phylogenetically isolated i.e. surrounded by phylogenetically distant neighbours, specialized herbivorous insects might find it difficult to track resources due to odour masking, or dispersal limitation imposed by the neighbouring trees. We studied resource tracking by groups of herbivorous insects and their parasitoids on individual oak trees that differed in the degree of phylogenetic isolation. For 4 years, we determined abundance of groups of herbivorous insects, the extent of herbivory, and potentially important leaf parameters. We also reared the sampled ectophagous Lepidoptera to determine parasitisation. Phylogenetic isolation reduced the tracking of resource quantity by ectophagous Lepidoptera and their parasitoids. Tracking of resource quality by ectophagous Lepidoptera as well as the resource tracking by endophagous herbivores were not affected by phylogenetic isolation. Our results suggest that host trees should escape from their relatives to avoid tracking of their resources by herbivorous insects.
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Oral Presentation 1 (O1) – 30th June
Session 2 (O1S2)
7 Functional and molecular characterization of Anopheles gambiae muscarinic receptors
Alexandre Pilon*, Delphine Goven, Valérie Raymond
UPRES EA 2647, USC INRA 1330,SFR QUASAV 4207, Laboratoire “Signalisation Fonctionnelle des Canaux Ioniques et Récepteurs » (SiFCIR), Université d’Angers, UFR Sciences 2 Boulevard Lavoisier 49045 ANGERS CEDEX, France
Keywords: Agronomy, Insect muscarinic receptors, Calcium imaging
Abstract: Agriculture has to face a great challenge: it must be ensured that enough high-quality food is available to meet the needs of a continuously growing population. Even if chemical pesticides such as insecticides have been used successfully in controlling several pest insects, their widespread uses have led to environmental and health concerns. It is then necessary to develop new strategies in order to reduce the use of pesticides in accordance with the Ecophyto 2+ program. The strategies developed in the laboratory are based on the intracellular calcium increase which modulates the sensitivity of insecticide targets. Indeed, it has been shown on Periplaneta americana neurones that intracellular calcium increase via muscarinic receptors (mAChRs) activation elicited by repellent leads to increase the insecticide neuronal target sensitivity. Muscarinic receptors could then be good candidates to develop a strategy leading to enhancement of the efficiency of insecticide treatment which can be used in pest control. In this study, we propose to characterize mAChRs in one of our insect models present in the laboratory which is the mosquitoes Anopheles gambiae. Insects mAChRs are known only in a few species and their molecular characterization remains to be explored. In Drosophila melanogaster, three types of mAChRs named mAChR-A, mAChR-B and mAChR-C have been found. Whereas the mAChR-A and mAChR-C are coupled to calcium signalling across Gαq/11 protein activation, the mAChR- B is linked to AMPc signalling across Gαi/0 protein activation. Our study consists in the molecular, functional, and pharmacological characterization of An. gambiae mAChRs. Using a bioinformatic approach, we shown the existence of a mAChR-A, two variants of mAChR-B (mAChR-B1 and mAChR-B2), and one mAChR-C in the anopheles which are homologous to their drosophila counterpart. To explore the signalling pathway of mAChR- A and its pharmacology, this receptor was expressed in Sf9 cell line. Using calcium imaging, we shown that mAChR-A is activated by acetylcholine, muscarine and oxotremorine and blocked by atropine. Using proteins inhibitors, we demonstrated that mAChR-A activation leads to an increase of intracellular calcium induced by the activation of the phosphoinositide pathway. Thus, in this study, we demonstrate that as the activation of anopheles mAChR-A induces the increase of cytoplasmic calcium, this receptor could be considered as a key element in a strategy to enhance insecticide treatment while reducing doses.
8 Study of fresh cheese volatile compound release while chewing and influence of aroma molecule equilibrium on flavour perception
Coline Caille a,b*, Cécile Rannou a, Angélique Villière a, Araceli Lagadec-Marquezb, Julia Bechauxb , Philippe Courcouxc, Carole Prosta aOniris-UMR CNRS 6144 GEPEA – MAPS² - Flaveur, France bGroupe Bel, France cOniris-INRA-StatSC, France
Keywords: alimentation, cheese, flavor
Abstract:
Food aroma compounds are release in the mouth while chewing. The mastication phenomenon depends both on the product and on the consumers who present an important variability. Therefore, standardizing this process with the use of an in vitro device can be useful. The first part of this research project consists in investigating, on the one hand, in vivo fresh cheese oral processing, both for children and adults as the product studied is consumed by these two populations. On the other hand, the aim is to optimize an artificial mouth to recreate as faithfully as possible the human mastication of the sticky homogenous cheese studied. In this way, in vivo masticatory parameters are measured on children and adults, and then transposed to the in vitro device. In vivo and in vitro boli are collected at different chewing stages to determine in vitro parameters that closely represent the mastication of these two populations. As children and adults present different chewing behaviours, two ways of in vitro mastication are set up. The second part of the study consists in studying the influence of texture and mastication temporality on fresh cheese volatile compound release. Thus, products presenting different textures are produced according to an experimental design. Cheeses are destructured through the artificial mouth previously set up and their volatile compounds are analysed. These instrumental data are then compared to the flavor perception of the products to determine which aroma molecules contribute the most to the cheese flavor. The impact of texture and mastication time on aroma release and flavour perception are also modeled. The last part, currently in reflection, will consist in investigating the influence of volatile compounds equilibrium on fresh cheese flavor perception. Olfactometry analysis and aromatic recombinations will be performed to elucidate the main odorant components and the impact of their relative abundance on the flavour perception. By better understanding the impact of product textural properties and chewing behaviour on aroma release and flavor perception, this work will able to improve the quality of industrial cheeses with a zero additive approach.
9 Effects of macrophytes on lentic macroinvertebrate assemblage and implications for water management
Benjamin Misteli1*, Gabrielle Thiebaut1, Alexandrine Pannard1, Christophe Piscart1 (* = presenting PhD student)
1 University of Rennes, CNRS, ECOBIO UMR 6553, 35042 Rennes, France
Keywords: Ecology, Macrophytes, Macroinvertebrates
Abstract: The structure and complexity of freshwater ecosystems shape the macroinvertebrate community inhabiting this environment. Macrophytes can play an important role in structuring aquatic communities by increasing heterogeneity, especially in lentic ecosystems. They can modify environmental conditions such as the availability of oxygen, nutrients, and light. Furthermore, macrophytes can provide additional habitat, shelter against predators, and food resources for macroinvertebrates. Aquatic macrophytes can thus promote diversity and abundance of macroinvertebrates but results vary strongly among different freshwaters ecosystems, plant types, and plant density. In this study, we sampled macroinvertebrates within macrophyte stands and in nearby plant-free habitats from multiple study sites in Africa and Europe. The aim of this cross-continent study was to find global and local patterns of the effects of macrophytes on macroinvertebrates. Overall, we found higher macroinvertebrate diversity and abundance within macrophyte stands. Furthermore, we identified the plant’s growth form (e.g. submerged or floating) as an important explanatory variable determining the magnitude of the impact. Differences found in macroinvertebrate communities with and without macrophytes also provide new insights into the sampling efficiency across different habitats. To fully cover the increased macroinvertebrate diversity, one can expect that more samples should be collected from macrophyte stands compared to plant-free sites. Our results therefore not only provide insight into the effect of macrophytes on macroinvertebrate communities but also support water managers and researchers to improve assessment of these communities in freshwater sites harboring macrophytes.
10
Geologically recent earthflow-like landslides on Mars
Anthony Guimpiera*, Susan. J. Conwaya, Axel Nobleta and Nicolas Mangolda aLaboratoire de Planétologie et Géodynamique CNRS UMR6112, Université de Nantes, France. Keywords: Geoscience, Landslides, Mars Abstract: Given the hyperarid climate that is believed to dominate the late Amazonian on Mars from 400 Ma to present day, landslides are generally interpreted as forming without liquid water [e.g., [1,2]. This study focuses on four small martian landslides of less than 20 Ma [3] with volumes <107 m3 located in a crater in the Nilosyrtis Mensae region at 27°N, 76°W. Using orbital images with a resolution from 6 m/pix to 25 cm/pix [4–6], we compared the morphology and inferred rheology of these landslides with terrestrial analogues. Located inside an impact crater of 25 km in diameter, these landslides have the following characteristics: (1) a lobate flow front, (2) lateral levees, (3) a sinusoidal longitude profile implying the absence of residual material in the landslide erosion zone and its accumulation in the deposition zone, (4) they occur mid-way down hillslopes between 20 and 25° in inclination, and (4) compression ridges are present on their deposits. These morphological characteristics are also expressed by terrestrial earthflows witch propagate over a wide range of slopes between 15° and 40° [7].
Terrestrial earthflows require liquid water to form. The similarities observed between these late Amazonian martian landslides and terrestrial earthflows, raises the question of the potential origin of liquid water to mobilise these landslides on Mars in such a recent period, when Mars is believed to be hyperarid. Two hypotheses can explain the origin of this liquid water: 1) the water comes from an underground aquifer or 2) from the local melting of ground ice under previous favourable climate conditions. Given the morphological observations on the area, we propose a blend of these two hypotheses. We identify sublimation surface textures which indicate the past presence of ice in the area. Moreover, the landslides are located below the elevation of the surrounding terrains, this opens up the possibility of migration of water in the subsurface, which then initiated these failures. We also consider the possibility that the clays that have previously been detected in this region [3] may have favoured failure via swelling on contact with water.
References: [1] C. Quantin et al. (2004) Planetary and Space Science, 52, 1011–1022. [2] V. Soukhovitskaya and M. Manga (2006) Icarus, 180, 348–352. [3] A. Guimpier et al. (In review) Planetary and Space Science. [4] M.C. Malin et al. (2007) J. Geophys. Res., 112, E05S04. [5] N. Thomas et al. (2017) Space Sci Rev, 212, 1897–1944. [6] A.S. McEwen et al. (2007) Journal of Geophysical Research: Planets, 112. [7] D.K. Keefer and A.M. Johnson (1983) U.S. G.P.O., Professional Paper.
11 Impact of temperature and concentration of four surface disinfectants on spoilage mold dry spores
Vincent VISCONTI, Karim RIGALMA, Emmanuel COTON and Philippe DANTIGNY
Univ Brest, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, F-29280 Plouzané, France
Keywords: Disinfectants, fungal control, alimentation
Abstract: In the dairy industry, the presence of spoilage molds cause economic losses. Airborne spores are an important source of contamination. To prevent the risk of contamination, commercial sanitizers capable of reducing the number of viable fungal spores are used either by direct surface contact or sprayed. In this presentation, four commercial sanitizers based on the following fungicide molecules (ethanol, sodium hypochlorite, hydrogen peroxide and triamine) were tested on dry-harvested spores of Aspergillus flavus, Cladosporium cladosporioides, Mucor circinelloides and two isolates of Penicillium commune. For each disinfectant, the most resistant isolate to recommended fungicidal concentration was selected to evaluate the efficacy of two additional concentrations at room temperature (20°C) and two additional temperatures (8°C and 15°C) at the recommended concentration. T4D was determined by non-linear regression. At the recommended concentration at 20°C, P. commune strain UBOCC-A-116003 was the most resistant to 60% ethanol and 0.075-0.1% triamine with T4D of 2.14 and 82.8 min respectively. P. commune strain UBOCC-A-112059 was the most resistant to 0.24% active chlorine with a T4D of 7.35 min. M. cicirnelloides was the most resistant mold to 7.9% hydrogen peroxide with a T4D of 39.3 min. At the reduced concentration tested, T4D was increased by factor 1.9 for 0.24% active chlorine and 6.32% hydrogen peroxide with T4D values of 13.2 and 71.8 min respectively. For 54% ethanol T4D was increased by factor 9.9 with T4D value of 21.2 min. Triamine based disinfectant was the least effective active substance. Increase to 1.8 times the recommended concentration reduced T4D by factor 1.3 with a T4D value of 63.2 min for 0.135-0.18% triamine. The decrease in temperature had a significant impact on the increase in T4D value. At 8°C the T4D value increased by factor 3.2 for active chlorine with T4D value of 23.8 min to factor 65.1 for hydrogen peroxide with a T4D value of 2558 min. For ethanol, the most effective disinfectant at room temperature, at 8°C the T4D value was increased by factor 21.9 with a T4D value of 47 min. At 20°C, ethanol and active chlorine were fast-acting disinfectants while hydrogen peroxide and triamine were long-acting disinfectants. The fungicidal concentrations recommended by the suppliers must be respected for optimal fungicidal efficacy. Decreasing temperature greatly reduces the effectiveness of biocides. To ensure the fungicidal activity of the product, it is necessary to apply longer contact times than those recommended by the suppliers, which are tested at 20 °C.
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Oral Presentation 1 (O1) – 30th June
Session 3 (O1S3)
13 Design of a participatory approach with consumers and winegrowers for the deployment of more respectful practices in the vineyard: a case study within the Cabernet d’Anjou
Diana Ugalde*, Ronan Symoneaux,
USC 1422 GRAPPE, INRAE, Ecole Supérieure d’Agricultures (ESA), SensoVeg, SFR 4207 QUASAV, 55 rue Rabelais 49007 Angers, France
Keywords: Sustainable wine, participatory approach, wine buyers
Abstract: Viticulture, like any agricultural activity, has impacts on the environment. At each stage of wine production, there are different impacts. Viticulture and packaging are one of the stages with the most negative impact on the environment because of the use of fuel and pesticides on the one hand, and the production and transport of glass bottles on the other. However, practices are evolving, and environmental concerns are intensifying with increasingly strict restrictions on phytosanitary products, a multiplication of environmental certifications, and more recently, the INAO and the IFV have published a Guide to Agroecology in viticulture to integrate more environmentally friendly practices in the specifications of appellations. One way to work on changing agricultural practices, is through participatory approaches, but these often only include producers, researchers, and agricultural advisors. In parallel, consumers are increasingly concerned about the effects of agriculture on human health and the environment (Forbes et al, 2009). There is also a strong demand for more information about provenance, production method, and sustainability of purchases (Ethicity, 2016; Feldmann & Hamm, 2015; Zhang et al, 2020., Walaszczyk et al, 2020). In wine, consumer interest and willingness to pay for sustainable wines is also confirmed (Bazoche et al, 2015; Galati et al, 2019; Lanfranchi et al, 2019; Palmieri & Perito, 2020; Schäufele & Hamm, 2017; Sellers, 2016; Tait et al, 2019). This shows that consumers can be prescribers of more sustainable wines and questions are raised about their integration in participatory approaches with winemakers to improve the deployment and valorization of more environmentally friendly practices in the vineyard and more specifically in Cabernet d'Anjou.
14 Organic agriculture and hedgerows uphold endospheric wheat microbiota at field and landscape scale
Claire Ricono a*, Philippe Vandenkoornhuyse a,d, Stéphanie Aviron b,c, Olivier Jambon a, Sophie Michon-Coudouel d, Romain Causse Vedrines d, Solene Mauger d, Cendrine Mony a,b
a* UMR CNRS 6553 ECOBIO, Université de Rennes 1, Campus Beaulieu, Avenue Leclerc, 35042 Rennes Cedex (France) b LTSER ZA Armorique, c INRAE agrocampus ouest d Plateforme génomique EcogenO
Keywords: Endophytes, Agricultural practices, Ecology
Abstract:
Agricultural intensification has been demonstrated to induce a loss of biodiversity in agroecosystems. Despite the key role of symbiotic microorganisms in plant nutrition and protection, the impact of agricultural intensification on microorganism diversity has been to some extent overlooked. Organic agriculture and field edges (as semi-natural elements) may promote a higher diversity in microorganisms because of lower anthropic and chemical disturbance and higher plant diversity. We sampled wheat individuals in pairs of wheat fields (one organic and one conventional) along a distance gradient to the edges (hedgerow versus grassy), in 20 landscapes selected along an uncorrelated gradient of organic agriculture and hedgerow density. Using a mass-sequencing approach, we analyzed the root endophytic microbiota (bacteria and fungi) of wheat. We demonstrated a higher fungal richness in organic fields (+9.3% for all fungi) and a decrease with the distance to the field edge at the field scale (-12% for all fungi). We also demonstrated a higher bacterial richness in fields surrounded with a high percent cover of organic agriculture at the landscape scale (+13%). Organic agriculture and field edges are thus refuges for microorganisms at both field and landscape scale. This work highlighted the influence of agricultural management on microorganisms that can occur at larger spatial scales than the field scale. Organic agriculture in the landscape might have a rescue effect of the field microbial assemblage even if landscapes are dominated by conventional agriculture.
15
Flavonoids and resistance of the carrot (Daucus carota) to Alternaria dauci
Marie-Louisa Ramaroson 1, Jean-Jacques Helesbeux 2, Latifa Hamama 1 and Mathilde Briard 1
1 Univ Angers, L’institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
2 Univ Angers, SONAS, SFR QUASAV, F-49000 Angers, France
Keywords: Specialized metabolites, plant defense, Agronomy
Abstract: Flavonoids are derived from the phenylpropanoid pathway in plant specialized metabolism. They are known to be involved in various processes in plant development and its interaction with the environment. Recent discoveries in carrot genotypes revealed a relationship between the accumulation of three candidate flavonoids and an improved resistance to Alternaria dauci. The present work aims to validate previous observations through i) the screening of a diversity set of carrot, ii) the follow up of the accumulation kinetics of the candidate metabolites along developmental stages, iii) the study of the control of their accumulation and iv) the investigation of their mode of action. First results will be presented.
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Landscape structure influences grassland productivity through changes in plant functional diversity
Lecoq Lucie1,2, Ernoult Aude1,2, Fabre Elodie3, Rapinel Sébastien3, Hubert-Moy Laurence 3, Mony Cendrine1,2
1: UMR CNRS ECOBIO, University of Rennes 1, Avenue du Général Leclerc, 35042 Rennes Cedex, France 2 : LTSER site « Zone Atelier Armorique » 3 : UMR CNRS LETG, University of Rennes 2, Avenue Gaston Berger, 35000 Rennes, France
Keywords: Ecology, landscape structure, functional trait, gamma diversity, primary productivity
Abstract: Agriculture intensification led to the gradual destruction of semi-natural habitats and landscape simplification in the landscapes of North-Western Europe. All these profound changes affected grassland plant assemblages. It could in fine have negative effects on the plant diversity and the related ecosystem functions, such as primary productivity. At the landscape scale this biodiversity-productivity relationship still have to be tested in real-world systems. It could have important economic implications concerning fodder production.
We used a large-scale sampling design (30 landscape windows – 1km²) to quantify landscape structure variables (semi-natural habitat amounts and landscape heterogeneity), grassland plant functional diversity calculated from multidimensional functional spaces (functional richness, evenness, dispersion), and grassland productivity (annual mean, temporal stability, spatial variability).
Functional diversity of grassland plant assemblages was related to semi-natural habitat amount but not to landscape heterogeneity. The three functional diversity indices decreased with grassland amount whereas the functional evenness increased with hedgerow amount. Grassland plant assemblages with a higher functional evenness displayed a higher annual mean productivity and lower spatial variability at the landscape scale.
We demonstrated the effect of landscape structure on grassland productivity at the landscape scale, with a functional-mediated effect through the amount of semi-natural habitats. Agricultural landscapes would benefit from the preservation and restoration of hedgerows, to ensure high plant functional diversity at the landscape scale, and to maintain efficient and resilient production of fodder in the future.
17
An overview of Pickering nanoemulsions: manufacturing processes, formulation and applications
Gaëlle Gauthier*, Isabelle Capron (* = presenting PhD student)
UR 1268 Biopolymères Interactions Assemblages, INRAE, 44316 Nantes, France Keywords: agronomy, Pickering nanoemulsion, wetting property. Abstract: Emulsions are metastable mixtures of two immiscible liquids, used for an increasing range of applications in food, cosmetics, pharmaceutics, agriculture and construction industry. For those industrial applications, products with long shelf-life are required. For high stability, a strategy is to obtain nano-sized dispersed droplets, with an average diameter below 200 nm. This low dimension prevents creaming and sedimentation, and limits thereby destabilization. However, it results in a large water-oil interface, and requires a big quantity of surfactant. But the use of surfactant is pointed out by regulations (i.e. REACH since 2007) for concerns on health and environment. For more eco-friendly emulsions, surfactants can be substituted by particles, forming Pickering emulsion. Another advantage of Pickering emulsion is their very high stability because particles are considered irreversibly anchored at the interface (contrary to small surfactants). Since their first apparition in 2012, the attention on Pickering nanoemulsions (NanoPickering) is growing. But depending on particle wetting properties, they do not necessarily spontaneously adsorb at the interface. Consequently, NanoPickering formulation could be more energy-intensive than surfactant nanoemulsions. Their manufacturing processes are divided in two categories: high-energy methods, using high shear processes, and low-energy methods, where nanodroplet formation is based on raw material physical chemistry. To stabilize the water-oil interface, inorganic (i.e. silica) and organic (i.e. cellulose derivative or solid lipid nanoparticles) particles are used. To improve their wetting properties, their surface chemistry can be tuned. Particles are also blended with surfactants to favour their anchoring at the interface and to increase emulsion stability. Then, the oil is carefully chosen to increase durability. With the appropriate formulation, it is possible to design complex responsive systems that respond for example to environmental modification, such as pH and temperature. Those emulsions are interesting for the local delivery of active-ingredient in pharmaceutics. Then, food shelf-life can be improved thanks to packaging enriched with NanoPickering in which agents such as anti-oxidant or antibacterial substances are encapsulated.
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Oral Presentation 1 (O1) – 30th June
Session 4 (O1S4)
19 Organic dairy calves reared with nurse cows and their impacts on Cryptosporidium infection
a* a a a Caroline Constancis , Christophe Chartier , Marion Bernard , Nadine Ravinet (* = presenting PhD student, subsequent authors optional) a* INRAE, Oniris, BIOEPAR, 44300, Nantes, France
Keywords: Agronomy, Cow-calf contact, Cryptosporidium
Abstract: Rearing dairy calves with nurse cows has been increasingly adopted by French farmers especially in organic farming and is characterized by a fostering of two to four calves during the first month of life by an unmilked lactating cow. This type of rearing remains poorly documented regarding its impact on calf health, such as cryptosporidiosis. The objectives of our study were to describe practices related to rearing dairy calves with nurse cows and to evaluate the prevalence, intensity and risk factors for Cryptosporidium infection in calf neonates. Between January and September 2019, the rearing practices of calves were described in 20 organic French farms and faeces were sampled once from 611 animals aged between 5 and 21 days. Cryptosporidium oocyst shedding was identified by modified Ziehl-Neelsen technique and scored semi-quantitatively (score 0– 4). The risk of excretion (score 0 versus 1–4) was analysed using multivariate logistic regression models. This cow-calf rearing system usually consisted of a first phase with the dam, followed by an optional phase of artificial milk feeding (calves being fed with whole milk of the farm) and a final phase of fostering by a nurse cow. Each nurse was suckled from one to five calves of close age with a fostering age of 8 days on average. The oocyst shedding prevalence was 40.2 % and similar to classically reared calves, but the intensity of shedding and the prevalence of diarrhoea appeared to be lower. The identified six risk factors for oocyst shedding were: born in the last two thirds of the birth order, born between January and July versus August and September, calf with its dam in the barn versus on pasture, having an artificial milk feeding phase versus being with the dam only, and contact between peer calves and notably the presence of an oocyst excretory calf fostered by the same nurse. These results emphasize the role of the environment for the direct and indirect contamination, particularly that related to the accumulation of oocysts from previous or peer calves facilitating the faecal-oral route of trans- mission. This highlights the crucial role of the premises used intensively during the winter and spring months with higher densities of calves in the barn compared to outdoor situations promoted by this rearing.
20 Bioavailability of amino acids, especially of tryptophan, in human milk and infant formulas
Elise Chartonab a UMR STLO 1253 Science et Technologie du Lait et de l’Œuf, INRAE, Institut Agro-Agrocampus Ouest, Rennes, 65 rue de Saint Brieuc, 35042 Rennes cedex, France b Institut NuMeCan, INRAE, INSERM, Univ Rennes, Domaine de la Prise - 35590 Saint Gilles, France
Keywords: Nutrition, Human milk, Amino acids bioavailability
Abstract: Human milk (HM) is considered as the “gold standard” for infant nutrition. Breastfeeding is recommended up to 6 months by the WHO and up to 4 months by the French PNNS. Despite these recommendations, breastfeeding rates in France decrease remain too low. The Epiphane study (2015) showed that only 21% of the 3 months-old infants were still predominantly breastfed. Hence, HM substitutes such as Infant formulas (IF) are required to feed infant who are not breastfeeding. IF composition aims to mime HM composition. HM amino acids bioavailability is the digested and absorbed peptidic and free amino acids fraction used for metabolism. However, the true availability of tryptophan is not known with certainty. Tryptophan is an essential amino acid that cannot be synthesized by the organism and need to be provided by the diet. It is involved in protein synthesis and in production of beneficial metabolites for infant growth, particularly for brain development (e.g.: serotonin (behaviour hormone)) and intestinal maturation (e.g.: indole).
Tryptophan, as an essential amino acid, is the limiting factor for establishing the protein value of standard IF (based on bovine whey proteins). Consequently, the knowledge improvement on tryptophan digestibility in HM and in IF will help to optimise the IF protein content. Furthermore, a better knowledge of the impact of the nature of milk (HM and IF) on tryptophan metabolism and production of derived metabolites is required to improve the growth and physiological properties of IF.
The main objective of the thesis is to determine the amino acids, and specifically tryptophan, digestibility in HM and IF using an in vivo infant model, the Yucatan mini-piglet. The second objective is to provide in- depth knowledge on the role of tryptophan in infant gut and brain development according to the nature of milk. The presentation will first introduce the context of the study and then, the first results of the thesis will be presented
21 Disentanglign the effects of farming intensity and semi natural habitats ar deifferent spatial scales on multifonctionality including both ecological and socio economic functions
Eloïse Couthouisa,b,c,*, Stéphanie Aviron a,c, Julien Pétillonb,c, Audrey Aligniera,c a UMR BAGAP, INRAE - Agrocampus Ouest – ESA, 35042 Rennes, France b UMR ECOBIO, CNRS – Université de Rennes 1, 35042 Rennes, France c LTSER Zone Atelier Armorique, 35042 Rennes, France
Keywords: Multifunctionality, Ecology, Agricultural landscapes
Abstract: In Europe, agriculture intensification has been pointed out a major driver of the decline of biodiversity and of the alteration of ecosystem services. Restoring biodiversity and associated services is crucial to allow the development of more sustainable farming systems and agricultural landscapes. Several strategies have been proposed to counteract this decline in agricultural landscapes. Among them, some rely on the extensification of management practices through the diminution of pesticide use, or on the maintenance/restoration of semi- natural elements in the close vicinity of fields i.e., planting hedgerows. The effects of these strategies are well documented for many biodiversity taxa, but they remain poorly understood from a multifunctional point of view. Here, we investigated the contribution of farming type (organic vs. conventional) and hedgerows at both local and landscape scale on both ecological functions (i.e. pest regulation, pollination and conservation) and socio-economic functions (i.e. agronomic, economic and social performances). We selected 40 crop fields, 20 under organic farming and 20 under conventional farming. Fields were distributed along two orthogonal gradients, one of proportion of semi-natural elements and one of proportion of organic farming measured in a 500m radius centred on each field in the Zone Atelier Armorique, north-western France. Vascular plant species and Arthropods (carabids, spiders, ladybird larvae, staphylinds, domestic and solitary bees, bumblebees, syrphids) are monitored along two transects, one located in the center of each field, another located along the hedgerow bordering each field, from May to July 2020. The hierarchical, pseudo- experimental design will allow to disentangle the effects of factors acting at different spatial scales (from local to landscape scale) on arthropod communities. Our study will thus arise critical issues regarding which strategies are relevant for enhancing the conservation of biodiversity, as well as pest regulation and pollination services and thus multifunctionality in agricultural landscapes.
22 Development of a new plant protection strategy through the screening and formulation of plant extracts active on the adaptative mechanisms of fungal plant pathogens Ophélie Dubreuab*, Thomas Guillemettea, Marie-Noëlle Brisseta, Emmanuel Pajotb a UMR 1345, INRA, Université d’Angers, Agrocampus-Ouest, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 Beaucouzé Cedex, Angers, France b Green Impulse, 1 rue Alexandre Flemming, 49000 Angers, France
Keywords: Agronomy, Phytopathology, Plant protection.
Abstract: Each year, more than a quarter of crop yield are lost, half of those due to diseases, especially fungal pathogens. Phytosanitary products are commonly used to control these pests but are however progressively removed from the market due to environment and human health impacts. Enhancing the quality and productivity of crops with minimal chemical inputs will be notably achieved by the development of new crop protection strategies. To date, several alternatives to standard chemicals, such as Plant Resistance Inducers (PRI), are being deployed but they are currently less efficient as phytosanitary products. The aim of this project is to develop a new strategy of plant protection aimed at exploiting a patent filed by the University of Angers in 2012, which could complement the use of PRI. This patent described molecules called Sensitines® able at low concentration to weaken the fungal adaptative response to stress by targeting specific pathways. Those molecules are adaptative response pathway inhibitors (ARPI). Once the fungi weakened, applying additional biocontrol products should be more efficient, especially those targeting the induction of plant defenses such as PRI. A synergistic effect is therefore expected which could allow to reach the efficiency of phytosanitary products. To develop the Sensitines® concept, various plant extracts has been studied to determine their potential as active substance. First, the global chemical composition of the extracts has been identified followed by the in vitro assessment of their inhibitory effect on fungal growth. Both results led to select one plant extract called Sensitines®QBA. The minimum inhibitory concentrations (MIC) have been determined in vitro against two plant pathogens: Alternaria brassicicola and Venturia inaequalis, respectively. MIC have been then used to investigate in vitro the ability of Sensitines®QBA to enhance the sensitivity of fungi to phytoalexins, which are plant defense molecules. An increased letal effect has been thus demonstrated for two indolic phytoalexins from Brassicaceae (brassinin and camalexin) against Alternaria brassicicola. Assessment of a synergistic effect in planta between Sensitines®QBA and various commercial PRI is currently in progress. After defining the doses to be applied and testing different formulations on the Venturia inaequalis / apple pathosystem, preliminary results showed a potential synergy and allowed to specifically target the most compatible PRI.
23
Biomimetic semi-permeable vesicles as microreactors to modulate the phase behaviour of macromolecules
Rémy Cochereaua*, Adeline Boirea, Denis Renarda
a INRAE, UR BIA, Impasse Thérèse Bertrand-Fontaine, 44000 Nantes, France
Keywords: Alimentation, Microreactors, Macromolecular assembly
Abstract: The understanding of the dynamics of the macromolecular assembly in solution, like liquid-liquid phase separation (LLPS), represents challenges in many fields. In cell biology, they represent a great interest, because of their involvement in subcellular processes [1] and human diseases [2,3].
To investigate these assemblies, we have developed a microfluidics method to produce biomimetic microreactors, called osmosomes [4]. These microreactors are vesicles composed of a lipid bilayer, made semi-permeable to small molecules (< 2 kDa), with the help of the membrane pore protein α-hemolysin [5]. They allow (1) encapsulating macromolecules in their ideal solubilization conditions, (2) to modify the quality of the solvent (pH, ionic strength, reducing agents, etc.) by controlled exchanges through the membrane pores, and (3) to probe the phase transitions of macromolecules. We demonstrated that the osmosomes solvent exchange rates can be less than 1 min. This allows to tune the macromolecules assembly with control of the thermodynamic pathway as observed for the pH-induced LLPS of wheat proteins (Figure).
Figure: Solvent-triggered LLPS of wheat proteins within an osmosome.
[1] T. Kojima and S. Takayama, ACS Appl. Mater. Interfaces. 10, 32782 (2018). [2] W. M. Babinchak, R. Haider, B. K. Dumm, P. Sarkar, K. Surewicz, J. K. Choi, and W. K. Surewicz, J. Biol. Chem. 294, 6306 (2019). [3] S. Ambadipudi, J. Biernat, D. Riedel, E. Mandelkow, and M. Zweckstetter, Nat. Commun. 8, 275 (2017). [4] R. Cochereau, D. Renard, C. Noûs and A. Boire, J. Colloid Interface Sci. 580, 709 (2020). [5] L. Song, M. R. Hobaugh, C. Shustak, S. Cheley, H. Bayley, and J. E. Gouaux, Science. 274, 1859 (1996).
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Posters Presentation 1 (PS1) – 30th June
25 Size fractionation highlights the mobility of copper from urban stormwater to river
Du Phuc Tho Dang, Béatrice Béchet, Liliane Jean-Soro
GERS LEE, Université Gustave Eiffel, Campus de Nantes, Allée des ponts et chaussées – CS 5004, F-44344 Bouguenais Cedex, France Keywords: geosciences, copper, physical speciation
Abstract: Copper is a ubiquitous essential element but also toxic to aquatic organisms, Environmental Quality Standards being 1 µg.L-1 for surface water (annual mean concentration). Rivers and estuaries are mainly concerned by copper accumulation in sediment and in organisms. Copper can originate from various manufactured products (antifouling painting, vineyards fungicides, brake linings….) and anthropic activities (industrial, landfills…). As a result, copper French median concentration in oysters is about 200 mg.kg-1 DM (Ifremer, 2017). Transportation, especially road transport, is the main French source of copper air emissions (92% of total emissions) (CITEPA, 2019). Then, urban areas, mainly impervious, constitute a major non-point source of copper from abrasion of brake pads and tires, and fuels. This contaminant is released from the road surfaces through stormwater runoff directly to water bodies or after collection in sustainable urban drainage systems (SUDS). As the epuration performance of SUDS for copper was shown to be low, this study is carried out to evaluate if copper mobility can be explained by its physical speciation. The distribution of copper among dissolved, colloidal and particulate fractions is studied by size fractionation, assuming that the mobility of copper is related to a high dissolved and colloidal occurrence. The study site is a retention-infiltration basin collecting the runoff water of the main bridge of Nantes (France; about 90 000 vehicles/day), and overflowing to the Loire river. Size fractionation by in series filtration and ultrafiltration was performed on stormwater runoff and surface waters sampled within the basin. Five fractions were analyzed for major and trace elements: ] ; 8µm ], ] 8µm ; 1,2µm ], ] 1,2µm ; 0,45µm ], ] 0,45µm ; 5kDa ] and ] 5kDa. Among these fractions ] ; 8µm ] correspond to particulate copper, ] 8µm ; 1,2µm ], ] 1,2µm ; 0,45µm ], ] 0,45µm ; 5kDa ] to colloidal copper and ] 5kDa ; [ to dissolved copper. Size fractionations were implemented for 8 samples with 2 replicates for each and over one year. 0.45 µm filtrations were also conducted as a reference. The total copper concentration in runoff was around 170 µg. L-1, which is in the upper part of the concentrations observed in the area of Nantes in SUDS. The results of the size fractionation are as follows: 1) for the runoff water, particulate copper is about 60% of the total amount, colloidal copper is present for 20% and 20% of dissolved copper is measured. Thus 40 % of copper are mobile; 2) for the surface water in the basin, the distribution of copper among the dissolved, colloidal and particulate fractions, is respectively 20 %, 75 % and 5 %. 95 % of copper are mobile in surface water; 3) for the infiltration water through a sandy substrate, 55 % of copper are in particulate form and 45 % of copper are mobile, with 30 % colloidal and 15 % dissolved. We concluded that 1) the concentration of copper is 100 times higher the regulation value for natural environment, and 2) particulate fractions of copper are trapped at the entrance of the basin, and a high content of mobile copper (dissolved and colloidal fractions) is observed in the basin that could either be overflowed or infiltrated in the sub-soil of the basin.
CITEPA, 2019. Gaz à effet de serre et polluants atmosphériques. Bilan des émissions en France de 1990 à 2017. Rapport national d’inventaire/Format secten. Ifremer, 2017. Qualité du milieu marin littoral. Bulletin de la surveillance 2016. Départements de Loire Atlantique et Vendée (partie Nord).
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The rheological properties of rennet gels depend on the divalent cation distribution in the casein micelles
Julien Bauland*ab, Marie-Hélène Famelart a, Fanny Guyomarc’h a, Romain Jeantet a, Saïd Bouhallab a, Thomas Croguennec a aSTLO, INRAE, Institut Agro, 35042, Rennes, France bCHR-HANSEN, 2970 Hoersholm, Danemark
Keywords: rennet gel; casein; mineral equilibria; rheology; Alimentation
Abstract: Milk rennet gels belong to the category of transient gels and their structure continues to rearrange after the gel setting. The dynamic character of the gel structure is of crucial importance for cheese-making as it is responsible for the gel firming before cutting and for the curd particle syneresis after cutting. The rearrangement of the gel structure is allowed by the viscoelastic nature of the bonds between particles building the gel, which eventually relax, allowing the mobility of the particles and the formation of additional bonds. At macroscopic scale, the gel viscoelastic properties can be assessed by small angle shear oscillatory rheology. The value of the phase angle can reflect the dynamic properties at microscopic scale. It has been hypothesized that the micellar calcium content affects the gel rheological properties by controlling the mechanical properties of the casein micelles. However, the rennet gel is built by cluster-cluster aggregation, and relevant structural scales to explain the macroscopic rheological properties of the gel are not yet clear. In this study, the mineral equilibria of milk samples were varied by adding different salts (CaCl2, MgCl2, Na2HPO4, CitNa3) or by varying the milk pH. These variations aimed at producing different partitions between precipitated and associated divalent cations in casein micelle. The mineral equilibria were modelled with the MilkSalts GLM software. The milk samples were gelled by rennet addition and a frequency sweep was initiated 120 min after rennet addition. Principal component analysis revealed that the dynamic properties of the gel indeed correlate with the micellar calcium content, whereas the absolute value of the shear moduli correlates with the concentration of divalent cations directly bound to phosphoserine, aspartic and glutamic residues of caseins. These results raise questions about the importance of intra- particle interactions for the gel rheological properties.
27 Hydrogeological controls on stream discharge dynamics in bedrock catchments: exploring the combined effects of seepage development and heterogeneity
Nicolas Cornettea,b*, Clément Roquesa, Alexandre Boissonb, Josette Launayc, Guillaume Pajotc,d and Jean-Raynald de Dreuzya,d a* Univ Rennes, CNRS, Geosciences Rennes - UMR 6118, F-35000 Rennes, France b BRGM – DAT Bretagne, Rennes, France c CRESEB, Rennes, France d OSUR, Rennes, France
Keywords: Geosciences, Hydrological modeling, Stream discharge dynamics.
Abstract: Surface/subsurface interactions and geological heterogeneity have important effects on the dynamics of streamflows. Surface/subsurface interactions speed up transfers through the development of seepage zones, which reduce the response time of the aquifer. On top of it, geological heterogeneity modulates spatially the extent of the seepage zones as well as the intensity of drainage of the underlying aquifer. We investigated the combined effect of the surface/subsurface interactions and geological heterogeneity in a crystalline basement region under temperate climate (Brittany, France). We analysed 40-year of discharge data monitored on two catchments (Arguenon 104 km2 and Nancon 67 km2) using 1D hillslope models (hs1D). The hs1D hillslope model resolves the vertically integrated Boussinesq subsurface flows with a spatially and temporally varying saturation-limited boundary condition on equivalent 1D hillslope structures. We specifically analysed the effect of accounting for heterogeneity on improving the discharge predictions, accounting for the presence of 2 equivalent hillslope with different hydraulic properties. Calibration was performed by a systematic parameter space exploration. The calibrated models display significant differences between the two catchments. In the Nancon catchment, the homogeneous and heterogeneous hillslope models had very close performances showing an effective geological homogenization of the hydraulic conductivity and porosity. In the Arguenon catchment, the heterogeneous model outperformed the homogeneous model with a 46% increase of the Nash-log criterion showing persistant and significant differences in hydraulic conductivities and porosity. Successful calibration in both cases demonstrated by Nash-log values larger than 0.75-0.8 showed the overall relevance of the hillslope approach and its capacity to check for the presence of hydraulic heterogeneity at the catchment scale. Differences between catchments hints on the potential identification of hydrogeological properties at the regional scale.
28 Elaboration of innovative multi-layered materials based on functionalized α-glucans
Delvart A.*, Moreau C., Leray N. and Cathala B.
INRAE, UR BIA, F-44316 Nantes, France
Keywords: polysaccharides, nanomaterials, ecology
Abstract: Over the last decades, interest for biobased polymers have grown due to the need to replace oil-based ones. Α-glucans exhibit high potential as candidates for the elaboration of innovative materials and surface assembly. Indeed, beyond from their large availability in nature, α-glucans display a large structural variability: large molar mass variation, various branching patterns, ramifications and chemical compositions with numerous possibilities of functional groups. In this context, functionalized α-glucans is of interest for designing news α- glucans based materials with innovative properties using manly layer-by-layer technique [1]. Dextrans sulfate are the most used α-glucans for layered assemblies elaboration since they display large panel of structures and attractive biological properties [2][3]. This presentation will focus on (i) the understanding of interactions between DexS with different charge densities and cationic polyelectrolytes through the screening of their adsorption mechanisms using Quartz Crystal Microbalance with Dissipation (QCM-D) and Surface Plasmon Resonance (SPR), (ii) the elaboration of multi-layered thin films preparation. Using DexS low sulfate content (DexS L40) and DexS high sulfate content (DexS H40) display different behaviour leading to contrasted architecture; DexS H40 presents linear growth of highly viscoelastic films and hydrated films while DexS L40 shows exponential growth of more rigid films and less hydrated structure. Our studies offer a simple method to control the structure of multilayered thin films opening the way to tunable functional materials.
[1] Decher, G.; Hong, J.-D. Makromol. Chem. Macromol. Symp. 1991, 46 (1), 321–327. [2] Heinze, T.; Liebert, T.; Heublein, B.; Hornig, S. In Polysaccharides II; Klemm, D., Ed.; Advances in Polymer Science; Springer Berlin Heidelberg, 2006; Vol. 205, pp 199–291. [3] Naessens, M.; Cerdobbel, A.; Soetaert, W.; Vandamme, E. J. J. Chem. Technol. Biotechnol. 2005, 80 (8), 845–860.
29
Realistic model for Environmental NanoPlastics (ENPs)
Florent Blancho a*, Mélanie Davranche a*, Julien Gigault b* a Géosciences Rennes,Université Rennes 1, 35042 Rennes, France b TAKUVIK, Université Laval/CNRS, Québec (Québec) G1V 0A6, Canada
Keywords: Geosciences, Nanoplastics, relevant model, environmental risk assessment
Abstract: Despite the increase in nanoplastic studies, a considerable lack of knowledge remains notably on their physicochemical properties. Indeed, environmental nanoplastics (ENPs) present a polymorphic structure/shape [1], that strongly differ from the polystyrene nanoparticle model (perfectly spherical) used for ecotoxicology studies [2]. While using such spherical nanoparticles is interesting to study the environmental risk of manufactured nanoplastics, they are not representative of ENPs. Therefore, closer ENPs models are needed to investigate the environmental behaviour of nanoplastics. The present study proposed a protocol to produce representative ENPs directly from aged plastic debris. This new ENPs models opens the door to further studies and new results concerning the environmental impact evaluation of plastic debris. References : [1] Gigault J, ter Halle A, Baudrimont M, et al. 2018. Environmental Pollution 235: 1030-34. [2] Bhattacharya P, Lin S, Turner JP, et Ke PC. 2010. The Journal of Physical Chemistry C 114 (39): 16556-61.
30
Biomarkers of seed quality using isotope assisted metabolomics in Medicago truncatula
Jean-Baptiste Domerguea*, Guillaume Tcherkeza a*UMR 1345 IRHS, Université d’Angers, 42 rue george morel 49071 Beaucouzé cedex
Keywords: Agronomy, seed quality, isotopes
Abstract: Seed quality plays a major role in modern agriculture, in particular in the present context of climate change and transitions in agricultural practices. The term "quality" is broad and includes varietal or specific purity of seeds lots, phytosanitary quality, germinative vigor and resistance to ageing, stress and diseases. Having seeds of sufficient quality is therefore essential for crop production (yield) and food industry. As such, it has been suggested that "good quality seeds are the basic source of a secure food supply" (Wimalasekera, 2015). Understandably, many research projects are devoted to molecular and genetic determinants of seed quality in crops. However, despite the importance of metabolism in germination (energy generation and reserve remobilization) and seedling establishment (anabolism and development of autotrophy), little is known on metabolic determinants of seed quality. To address this question, we propose the use of natural variability (in germination performance and velocity of seedling establishment) in barrel clover (Medicago truncatula). To do so we exploit a "core collection" of M. truncatula to study the natural variability in metabolic parameters (metabolite content, natural isotope abundance) and how it relates to quality indicators. This involves techniques such as GC-MS, EA-IRMS and GC-C-IRMS, i.e. mass spectrometry techniques allowing metabolomics profiling and measurements of natural isotope abundance (delta values). Isotope‐ assisted metabolomic data can then be linked to physiological aspects such as germination performance, nitrogen use efficiency, seedling growth rate, etc. using statistical tools (including machine-learning) associating quantitative physiological traits with metabolic features. Here, the use of isotopes is an important objective because we might be able to find simple relationships between quality of seeds and delta values, while delta values are easy to measure and therefore have a significant potential for agronomic application. As we showed in our recent review (Domergue et al., PC&E), it seems that there is no general rule for pool sizes of metabolites in their relationship to seed vigor. There is thus a need for techniques that will allow identification of biomarkers reflecting functional properties, and that is what isotopes will help achieving.
31 Investigating the origin of soft cheeses color defect
Marion Valle a,b, Nicolas Nguyen Van Long b, Jean-Luc Jany a, Karim Rigalma a, Valérie Vasseur a, Véronique Huchet b, Louis Coroller a a Université de Brest, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, UMT ALTER’IX, F-29000 Quimper, France b ADRIA Développement, UMT ACTIA 19.03 ALTER’IX, Quimper, France Keywords: alimentation ; fungi ; water activity. Abstract: In food industry, filamentous fungi can be used for the production of fermented products, e.g. Penicillium camemberti and Geotrichum candidum are usually used as culture adjunct to ripen soft cheeses (e.g. Camembert, Brie). In some cases, an undesirable yellow or brown color can appear on the cheese surface. According to different authors, Penicillium camemberti was hypothesized to play a role in this coloration defect. The present case-study aimed to investigate a specific color defect issue observed at the manufacturing level. Samples of spoiled and non-spoiled (controls) industrial cheeses were collected. This study was focused on Brie (30 samples) for which enough crust was available for all analyses. Microbiological, colorimetric and physico-chemical analyses (measurements of water activity, pH, dry matter and volatile fatty acid, NaCl, lactates and tyrosine contents) were performed on cheese surface. The data collected were analysed by a Principal Component Analysis (PCA). Two types of cheese were identified with the PCA : i) cheeses with an undesirable yellow color (spoiled cheeses) and ii) control cheeses without visible and detectable spoilage. Compared to control cheeses, the yellow cheeses are associated with a relative high presence of Penicillium camemberti and high contents of NaCl, L-lactates, acetic acid, isovaleric acid and iso butyric acid. In addition, these cheeses had low values of pH, water activity, relative presence of Geotrichum candidum and contents of butyric acid and caproic acid. The water activity of yellow cheeses was lower than in control cheeses explained by a high salt content. G. candidum is described as a salt sensitive species. Therefore, we assumed that this defect may be probably due to an inhibition of G. candidum growth by high salt content. Therefore, the fungi could not cover the cheese surface. Moreover, the pH and the content of butyric acid of yellow cheeses were lower than in control cheeses. G. candidum is described as a species which consumes lactate but not lactose and produces butyric acid. If G. candidum growth was inhibited by high salt content there were not lactate consumption (linked to a low pH) and butyric acid production. High salt content might be due to a salting step of cheeses which was not homogenous or the curd was not homogenous which leading to a heterogeneous diffusion of salt in the cheese matrix.
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Developing a multihost African swine fever transmission model at the domestic-wildlife interface
Brandon Hayesab* , Timothée Vergnea , Nicolas Roseb , Mathieu Andraudb (* = presenting PhD student) aUMR ENVT-INRAE 1225, Ecole Nationale Veterinaire de Toulouse, Toulouse, France bAgence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Ploufragan, France
Keywords: Ecology, African swine fever, mathematical modelling
Abstract:
African swine fever (ASF) is one of the highest consequence diseases of domestic pigs. With a case-fatality rate approaching 100% for highly-virulent strains - including the current strain responsible for the on-going Eurasian pandemic - and severe trade restrictions wherever its emergence is recognized, ASF poses a grave threat to the global swine industry. Without an available vaccine, understanding transmission dynamics is essential for designing effective prevention, surveillance, and intervention strategies. Mathematical modelling has proven useful for quantifying disease transmission and informing control strategies among domestic pigs and wild boars separately. Such models are sufficient for regions where ASF is restricted to a single ecological compartment, however for areas where spillover between hosts is suspected — as in Romania where exists a predominance of low biosecurity backyard pig holdings — a multihost approach is likely needed. Past epidemic analyses revealed disease spread could not be explained exclusively by anthropogenic movements. To explain the spatio-temporal infection pattern among commercial and backyard pig farms and wild boar hosts, a discrete stochastic space-time survival model was developed. Domestic pig herds were modelled using coordinate data and their level of biosecurity (industrial or backyard holding), and wild boar presence was represented through ecological habitat variables. Model fitting will be performed through approximate Bayesian computation – sequential Monte-Carlo methodology. The model outputs will be used to quantify the influence of wild boar on ASF spread among domestic pigs and assess the effectiveness of various control strategies during the initial phase of the epidemic.
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Effect of abiotic factors and culture media on the growth of cheese- associated
Nectriaceae spp.
Océane Savarya*, Monika Cotona, Jean-Luc Janya, Louis Corollera and Emmanuel Cotona# aUniv Brest, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, F-29280 Plouzané, France
Keywords: Fungal growth, cheese, alimentation
Abstract: Bisifusarium domesticum is a fungal species used for its technological role in various cheese productions. This species is of particular interest as it has, so far, only been isolated from the cheese environment and, until recently, was the only Nectriaceae species described in cheese. However, investigation of various cheese rinds for B. domesticum isolate collection revealed an unexpected diversity of Fusarium-like fungi with putative novel cheese-associated species. Based on a combination of multi-gene phylogenetic analysis, morphological description and metabolite profiling, four novel species were described, namely Bisifusarium allantoides, Bisifusarium penicilloides, Longinectria lagenoides, Longinectria verticilliforme, the two latter belonging to a novel genus (Longinectria gen. nov.). These species, along with B. domesticum, represent the only cheese-associated Nectriaceae species to this date while other members of this family have been described in various natural environments (soil, decaying wood, plants), or as plant or human pathogens. This variety of biotopes raise questions concerning the potential adaptation of the cheese-associated species to this food matrix. In this context, this study focused first on the impact of abiotic factors on the growth of the five cheese-associated species but also of other phylogenetically close species for comparison purposes. To do so, a nephelometric method was applied to determine fungal growth kinetics in liquid medium (Potato Dextrose Broth) at different temperatures, pH and water activities. Growth rates were determined for each condition to estimate cardinal values for a given abiotic factor. Secondly, the growth of selected representative strains was evaluated on various media, namely Potato Dextrose Agar (synthetic), Cheese Agar (cheese-mimicking) and Raclette de Savoie cheese (actual cheese). Overall, this study highlighted the existence of four novel Nectriaceae species in cheese and physiological differences in growth characteristics between the cheese-associated Nectriaceae species and the other studied species suggesting an adaptation to this food matrix.
34
Oral Presentation 2 (O2) – 30th June
Session 1 (O2S1)
35
Helium Charge Transfer Dissociation: an emerging fragmentation method Applied for a better understanding of the structure-function relationships in carrageenans
Lissarrague A.*ab, Jam M.c, Mangiante G.d, Fanuel M.ab, Boulenguer P.d, Ropartz D.ab, Hervé C.c, Rogniaux H.ab
a INRAE, UR BIA, F-44316 NANTES b INRAE, BIBS platform, F-44316 NANTES c CNRS, UMR 8227, Station Biologique de Roscoff, F-29680 ROSCOFF d Product & Processes Development Center, Cargill Starches Sweeteners & Texturizers, F-50500 BAUPTE
Keywords: Alimentation; Chemistry; Carbohydrates
Abstract: Carrageenans are heterogeneous polysaccharides present in the cell wall of some red seaweeds. They are made of building blocks consisting of galactose disaccharides, with various and disparate moieties (sulphation, anhydrous bridges, etc.). Carrageenans have many potential1 and actual applications in industry, such as food or cosmetic industries2 where they are massively used as texturing agents. The functional properties of carrageenans—and thus their end-uses—are closely related to their structure (i.e., their degree of polymerization (DP), sequence and type of blocks in the chain). However, there is a large heterogeneity of natural carrageenan motifs (which can be present within the same macromolecule), and their exact structure remains partly unknown. Developing new applications of carrageenans, or optimizing existing ones, requires improving this knowledge, as well as improving our understanding of their structure-property relationship. To achieve this goal, we need to be as precise and comprehensive as possible in determining structures of carrageenans.
Structural complexity of carbohydrates has long challenged analytical sciences. But, recent advances in mass spectrometry ha considerably improved the analytical toolkit in glycosciences. Indeed, helium charge transfer dissociation (He-CTD) is an emerging useful fragmentation method3, resulting in many informative cross-ring fragments while maintaining labile modifications. This makes it possible to localize the modifications carried by the galactoses and finally to reach a complete structure determination for oligo- carrageenans up to DP 18. Moreover, we now have access to several enzymes capable of hydrolysing the raw polymer into oligosaccharides of such DPs, with a defined specificity4. In this talk, we will see some characterized structures of oligo-carrageenans from genetically characterized pools of Chondrus Crispus (a genomic model for red algae) and industrial extracts from other seaweed species.
References:
[1] Pacheco-Quito E.-M., Ruiz-Caro R. & Veiga M.-D., Mar. Drugs., 18, 583, 2020 [2] Zamorano J. & Canivet F., Techniques de l’ingénieur, 2018 [3] Ropartz D., Li P., Jackson G. P. & Rogniaux H., Anal. Chem., 89, 3824-3828, 2017 [4] Jouanneau D., Boulenguer P., Mazoyer J. & Helbert W., J. Appl. Phycol., 23, 105, 2011
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Successive inoculations of pigs with porcine reproductive and respiratory syndrome virus and swine influenza A virus result in a two-way interference between both infections
Juliette Bougon1,2*, Céline Deblanc1, Patricia Renson1, Stéphane Quéguiner1, Stéphane Gorin1, Sophie Mahé1, Mireille Le Dimna1, Nicolas Barbier1, Frédéric Paboeuf3, Gaëlle Simon1, Olivier Bourry1 (* = presenting PhD student)
1ANSES, Ploufragan-Plouzané-Niort Laboratory, Swine Virology Immunology Unit, BP53, 22440 Ploufragan, France 2University of Rennes 1, Cité Internationale, 1 Place Paul Ricoeur, CS 54417, 35044 Rennes, France 3ANSES, Ploufragan-Plouzané-Niort Laboratory, SPF Pig Production and Experimentation Unit, BP53, 22440 Ploufragan, France
Keywords: Porcine respiratory disease complex, viral interference, agronomy
Abstract: In pigs, respiratory diseases are commonly owed to association of viral and/or bacterial pathogens under the porcine respiratory disease complex (PRDC). PRDC is a major issue for producers because of economic impacts and public health concerns due to zoonotic pathogens. PRRSV and swIAV are among leading players in PRDC, frequently detected in the same production areas and regularly encountered simultaneously in herds. As studying single infections neglect the virus-virus interactions that may occur, we set-up an experimental model to study both the effect of PRRSV infection on a subsequent swIAV infection and the impact of swIAV infection on the ongoing PRRSV infection.
Twenty-four specific pathogen-free piglets were distributed into four groups of six: one inoculated with PRRSV-1 at study day (SD) 0; one inoculated with swIAV (H1huN2) at SD8; one successively inoculated with PRRSV and swIAV one week apart at SD0 and SD8; one mock-inoculated. Clinical parameters were measured daily and nasal swabs, bronchoalveolar lavages and blood samples were collected regularly to measure virological and immunological parameters at both systemic and pulmonary levels.
In the PRRSV/swIAV group, contrasting with the swIAV group, the clinical signs usually observed after swIAV inoculation were attenuated. Virological monitoring indicated that swIAV nasal shedding was slightly delayed in PRRSV pre-infected pigs, whereas PRRSV replication in lungs was highly disrupted following swIAV super-infection. Antiviral (IFN-α) and inflammatory (haptoglobin) responses were reduced in PRRSV/swIAV group, as compared to swIAV group, while a slight anti-inflammatory (IL-10) response was induced in the lung of co-infected animals. In addition, the influx of granulocytes were limited at systemic and pulmonary levels in PRRSV/swIAV group, as compared to swIAV group. Also, a stronger humoral response against swIAV in lungs from PRRSV/swIAV group was observed, as compared to swIAV group. In addition, the cell-mediated response specific to PRRSV was induced faster and stronger in PRRSV/swIAV group, as compared to single-infection group. Correlation analyses evidenced a pivotal role of the antiviral cytokine, IFN-α, in the impacts one virus infection had on the other one.
Thus, this study highlighted a two-way interference between PRRSV-1 and swIAV (H1N2) infections, suggesting the co-infected host could take some advantage of such an antagonistic virus-virus interaction.
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Assessing the impacts of hydromorphological restoration in headwater streams
Gbenga E. Omoniyi a*, Benjamin Bergerota, Christophe Piscarta (* = presenting PhD student) a*UMR CNRS 6553 ECOBIO, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France
Keywords: ecology, stream restoration, bio-indicators
Abstract: The assessment of restoration activities in streams has mostly relied on biodiversity with results riddled with many uncertainties. Consequently, there has been a growing call for a more robust bio-assessment protocol that integrates ecosystem functioning with biodiversity for the assessment of the ecological status of restored streams. In addition to macroinvertebrate biodiversity, we proposed a suite of complementary bio- indicator tools for the assessment of the ecological status of restored streams. These include an integrative ecosystem-level process – leaf litter decomposition using the litter bag experiment, sediment oxygenation taken by measuring the depth of oxygen band on hypoxia sticks installed in the streambed for 30 days and lastly, macroinvertebrates species functional traits. These were monitored on two restored streams in Brittany, Northwest France. The restoration works involved the removal of artificial obstruction to flow. Sites were monitored both pre- and post-project for at least 18 months in each case. Sediment oxygenation was measured every season, leaf litter assay every winter and macroinvertebrate samples were taken in spring and autumn. We observed increased depths of sediment oxygenation in restored stream sections comparable to the depths in reference sites. The depth also increases upstream with increasing distance from the site of restoration suggestive of an improved sediment transport downstream. Also, the rate of litter breakdown was higher post restoration than before restoration even though values at reference sites remain higher than values in impacted sections both pre- and post- restoration. The trend in litter composition was strongly correlated to the functional composition of macroinvertebrate shredders rather than the structural assemblages. While the classical biodiversity metrics have historically proved useful in assessing the ecological status of streams, incorporating ecological processes and functional traits of biota into the assessment protocols of restored streams will provide a more integrative and mechanistic assessment of ecological responses.
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Skin formation in drying droplets of dairy proteins
Ming Yua*, Cécile Le Floch-Fouéréa, Françoise Boissela, Ludovic Pauchardb, Arnaud Saint-Jalmesc, Romain Jeanteta, Luca Lanottea a*STLO, INRAE, Institut Agro, 35042 Rennes (France) bLaboratoire FAST, UMR 7608, CNRS – Université Paris-Saclay, 91405 Orsay (France) cInstitut de Physique de Rennes (IPR), UMR 6251, CNRS – Université de Rennes, 35000 Rennes (France)
Keywords: dairy colloids, skin formation, Food sciences
Abstract: The evaporation of a colloidal dispersion is characterized by solute accumulation at the air- liquid interface, leading to the gradual formation of a gelled skin. From the preliminary colloid deposit to complete solidification, the development of this layer affects the overall drying process and final sample morphology. Despite progress in the last decades, the mechanisms governing skin formation in drying colloidal suspensions have not yet been fully clarified, especially in complex polydisperse systems. This work investigates droplet skin formation in a binary dairy proteins system, i.e. whey proteins isolates (WPI), and native phosphocaseinates (NPC). A single droplet approach was used to explore both droplet morphology evolution and drying kinetics as a function of WPI relative fraction in the overall protein content (WPI%R). The observation of the evaporation stages highlighted the separate role of WPI and NPC on drying dynamics, leading to two shape categories characterized by skin buckling (WPI%R≤20%) and rigid convex shell (WPI%R≥50%), respectively. Mainly, estimating droplet drying kinetics and sol-gel transition characteristic times highlighted WPI significant impact above a critical value (WPI%Rc), resulting in a rigid skin with high resistance to buckling. Such enhanced mechanical properties suggest WPI external segregation during skin formation, whose evidence was provided by the direct observation of dry skin section structure. The hypothesis of protein stratification by size was corroborated by the agreement with recent predictive models on the evaporation of bidisperse model colloidal suspensions. Finally, the organization of protein molecules throughout the interface gelification process was also investigated by interfacial rheology tests, stressing significant similarities between ageing- induced and drying-induced gelled interface behavior above WPI%Rc. This study contributes to a better understanding of the competitive drying mechanisms occurring in binary colloidal systems.
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Contribution of earthworm bioturbation to the structure of engineered soils
Jeanne Maréchala,b*, Denis Pirona, Kevin Hoeffnera, Xavier Mariéb, Daniel Cluzeaua a* UMR ECOBIO 6553, Université de Rennes 1, Station biologique de Paimpont, 35380 Paimpont b* Sol Paysage, 8 bis boulevard Dubreuil, 91 400 Orsay
Keywords: Ecology, Earthworms, Bioturbation
Abstract: The demand for urban green spaces is growing to improve life quality in cities, leading to higher awareness of the pedological engineering of urban soils. To ensure plant growth in constrained environments, pedological engineering is focusing on ensuring adapted soil structure. In temperate climates, soil structure is highly modified by earthworm bioturbation. However, little is known about the proportion of soil structured by earthworm bioturbation and how physical, chemical and, microbiological properties are modified in soils by earthworm bioturbation. The main objectives of this study were to (i) quantify bioturbation patterns at the profile scale (0 to 50 cm deep); to (ii) compare physical (texture, bulk density, water retention), chemical (pH, organic carbon, nitrogen, CEC, phosphorus, exchangeable cations), and microbiological properties (microbial biomass, respiration, nitrification, denitrification) between bioturbation patterns and bulk soil. We selected two types of engineered soils: (1) 30-year-old Anthropised Luvisols (30AL) from a shallow stripping of the existing soil and an addition of 30 cm of topsoil, and (2) 20-year-old Reconstructed Anthroposoils (20RA) from a deep stripping of the existing soil and an addition of 150 cm of topsoil, amended with compost in the 25 first cm. Pedological pits were dug and a grid frame (1.2 cm x 1.2 cm) was placed vertically against the surface of the soil profile to map bioturbation patterns on a square surface of 50 cm x 50 cm. According to the typology of bioturbation patterns established by Piron et al. (2012), each cell of the grid was associated with the major pattern of casts (i.e., more or less coalescent) observed at the location of the cell. Briefly, the proportion of casts was significantly higher in 20RA than in 30AL (resp. 71% and 59%), showing that deep reconstructed soils with soil-compost mixture can be more favourable to earthworm bioturbation (e.g., less compacted horizons, more available food resources) than lightly modified Luvisols. No differences were observed between properties of casts and bulk soil of 20RA and 30AL, highlighting a homogenisation of engineered soil properties with time. Overall, this study showed that a significant proportion of the soil is impacted by earthworm bioturbation, highlighting the key role of earthworms in the structuration of engineered soils.
40
Genetic variability of nesting behavior and egg production traits for laying hens raised in a cage-free system
Lorry Bécotab*, Nicolas Bédèrea, Jenna Cotonb, Thierry Burlotb, Pascale Le Roya a PEGASE, INRAE, Institut Agro, F-35590, Saint-Gilles, France b NOVOGEN, F-22960, Plédran, France * Presenting PhD student Keywords: Agronomy, quantitative genetics, laying hens
Abstract: In laying hens, the importance of cage-free systems (barn, free-range and organic) has increased in recent years. These systems require that laying hens lay their eggs in nests. Indeed, off-nest laid eggs impair the production performance of the flock because they are most of the time downgraded or lost. Consequently, select laying hens on nesting behavior would be a good opportunity to reduce off-nest laid eggs and improve egg production. However, little is known about such traits. Our study aimed at estimating genetic parameters of nesting behavior traits and their genetic correlations with a production trait, in order to evaluate their potential inclusion in breeding programs. Data were continuously recorded on laying hens raised in a barn thanks to individual electronic nests, which use radio-frequency identification of hens. Nesting behavior and production traits were recorded between 24 (peak of egg production) and 64 (middle of egg production) weeks of age on two pure lines: 1,430 Rhode Island Red hens (RIR) and 1,008 White Leghorn hens (WL). The nesting behavior traits studied were the mean laying duration (MLD), i.e. the mean time spent in the nests to lay, the mean distance between nests of laying (MDN) and the rhythm of lay, like clutch number and the mean oviposition time (MOT). The egg production trait studied was the laying rate in the nests (LRN). Genetic parameters were estimated by applying the restricted maximum likelihood method to an animal model. High (0.55 and 0.68) and moderate (0.32 and 0.37) heritability estimates were found for MLD and MDN respectively. For these two traits, null or favorable genetic correlations with LRN were estimated. Select laying hens with a low MLD and high MDN, i.e. high exploratory behavior, could help to reduce off-nest laid eggs. In the two lines, high heritability estimates were found for clutch number and MOT with values between 0.40 and 0.66. For LRN, heritability estimates were 0.09 and 0.25 for RIR and WL respectively. Strong negative genetic correlations (-0.72 and -0.61) were estimated between clutch number and LRN, indicating that select laying hens with a low clutch number could increase LRN. Genetic correlations between MOT and LRN were lower with estimates values from -0.04 and -0.44 for RIR and WL respectively. The existence of a genetic background for nesting behavior traits is promising to identify quantitative traits locus and candidate genes implicated in the expression of such traits.
41
A novel mediator of rhizospheric plant-microbe interactions: microRNAs
Harriet Middleton1,2,*, Virginie Daburon1, Emmanuel Clostres1, Christophe Penno1, Étienne Yergeau2, Cécile Monard1, Abdelhak El Amrani1
*Presenting PhD student 1University of Rennes 1, CNRS/UMR 6553/OSUR, Ecosystems - Biodiversity - Evolution, 35042 Rennes Cedex, France 2Institut National de la Recherche Scientifique, Centre Armand-Frappier Santé Biotechnologie, Laval, H7V 1B7, Canada
Keywords: Ecology, microRNAs, plant-microbe interactions
Abstract: The rhizosphere is a dynamic interface between plant and soil, crucial not only for nutritional purposes, but also for interactions between the plant root and microorganisms. The current paradigm is that the rhizospheric microbial communities are under stringent selection caused by plant root exudates. We hypothesize that small non-coding RNAs, namely microRNAs (miRNAs), are also implicated in defining the composition and activity of the rhizospheric microbiota. Indeed, (i) the cross-kingdom exchange of small RNAs between plants and fungal pathogens (Wang et al. 2016) and (ii) the impact of host fecal miRNAs on the composition of the gut microbiota (Liu et al. 2016) points toward the existence of a similar mechanism between plants and their rhizospheric microbiota. The rhizospheres of the model plants Arabidopsis thaliana and Brachypodium distachyon were therefore sampled and their miRNA content sequenced. Two independent experiments similarly showed that there is an abundance of plant- specific miRNAs in the rhizosphere, absent from unplanted soils, many of which were shared by both plants. We have further shown that many of these miRNAs can be found inside bacteria that were isolated from the rhizosphere of A. thaliana, suggesting that bacteria do incorporate plant rhizospheric miRNAs. The rhizosphere microbial communities from mutant Arabidopsis plants, affected in their miRNA and/or siRNA (small interfering RNA) pathways, were severely affected. In order to confirm the role of plant miRNAs on rhizospheric microbes, we are currently investigating, in vitro, the effect of synthetic ath-miRNAs on the development of soil bacteria. Our investigation is in its early stages and many complementary experiments are ongoing to decipher the intricacies of miRNA exchanges in the rhizosphere, which could lead to a paradigm shift in plant-microbe interactions, with many potential applied consequences.
42
Oral Presentation 2 (O2) – 30th June
Session 2 (O2S2)
43 Environnemental assessment of contrasted organic vegetable farms in France
Antonin Pépina,b*, Kevin Morelc, Hayo M.G.van der Werfb a * CTIFL Ctr St Remy, Route Mollèges, 13210 St Remy de Provence, France b UMR SAS, INRAE, Institut Agro, 35000 Rennes, France c UMR SADAPT, INRAE, AgroParisTech, Université Paris-Saclay, 75005 Paris, France
Keywords: Agronomy, Life Cycle Assessment, Organic Vegetable Production
Abstract: In France, 11% of vegetable farms are organic (Dedieu et al., 2017). These farms are very diverse, both in terms of farm structure and farming practices, ranging from large farms growing few crops with a high level of external inputs –close to conventional agriculture – to biodiversity-based microfarms. Microfarms are characterized by a wide variety of vegetables produced - more than 30 - on small acreage - less than 1.5 ha per full-time equivalent (Morel and Leger, 2016). These systems are often conducted by farmers aiming to minimize environmental impacts, however, late adopters of organic farming have been shown to be less concerned about the environment than early adopters (Best, 2008). After characterizing the farming systems through a typology, we assessed the environmental performance of these systems using life cycle assessment (LCA). LCA of agricultural systems still raises methodological challenges, especially when it comes to complex and diversified systems, which rely heavily on the services provided by biodiversity (Foresi et al., 2017). We compared the environmental impacts of different farm types at farm scale based on case studies, for several impact categories (e.g. climate change, marine and fresh water eutrophication, land use). We also compared the environmental impacts of vegetables produced in different farming systems and highlighted the main contributors to the environmental burden.
44
Positive interactions between lactic acid bacteria promoted by nitrogen-based nutritional dependencies
Fanny Canon1*, Marie-Bernadette Maillard1, Gwénaële Henry1, Anne Thierry1, Valérie Gagnaire1 1UMR STLO, INRAE, Institut Agro, F35000, Rennes, France
Keywords: lactic acid bacteria, positive interactions, alimentation
Abstract: Lactic acid bacteria (LAB) interactions are often studied in association with yeasts or propionibacteria in various fermented food products and the mechanisms underlying their interactions are being quite well characterized. Concerning interactions between LAB, which are responsible for the sanitary, organoleptic, and health properties of most fermented products, they have mainly been investigated to test antagonistic interactions. Understanding how they can positively interact could be useful in multiple food-related fields: production of fermented food products with enhanced functional properties or fermentation of new food matrices. Nutritional dependencies, especially those regarding nitrogen sources, govern numerous microbial positive interactions. As for LAB, such positive interactions, have previously been studied between yogurt bacteria. However, they have never been exploited to create artificial co-cultures of LAB that would not necessarily coexist naturally, i.e from different biotopes. The objective of this study was to promote LAB positive interactions based on nitrogen dependencies in co-cultures to increase acidification rates, carbohydrate consumption, and volatile compound production. The strategy was to exploit both proteolytic activities and amino acid auxotrophies of LAB. A chemically defined medium was thus developed to specifically allow the growth of six LAB strains used, three proteolytic and three non-proteolytic. Each of the proteolytic strains, Enterococcus faecalis CIRM-BIA2412, Lactococcus lactis NCDO2125, and CIRM-BIA244, was co-cultured with each one of the non-proteolytic LAB strains: L. lactis NCDO2111, Lactiplantibacillus plantarum CIRM-BIA465 and CIRM-BIA1524. Bacterial growth was monitored using compartmented chambers to compare growth in mono- and co- cultures. Acidification, carbohydrate consumption and volatile compound production was evaluated in direct co-cultures. Each proteolytic strain induced different types of interactions: either strongly positive, weakly positive, or no interactions, with E. faecalis CIRM-BIA2412, L. lactis NCDO2125 and L. lactis CIRM-BIA244, respectively. Strong interactions were associated with higher concentrations in tryptophan, valine, phenylalanine, leucine, isoleucine, and peptides. They led to faster acidification rates, lower final pH, higher raffinose utilization, and higher concentrations in five volatile compounds.
45 Rift Valley fever hosts are not equal – Modelling infectiousness at the individual level
Hélène Cecilia*a, Roosmarie Vriensb, Raphaëlle Métrasc, Jeroen Kortekaasd,e, Paul Wichgers Schreurd, Mariken de Witb, Pauline Ezannoa, Quirine ten Boschb
a INRAE, Oniris, BIOEPAR, 44300, Nantes, France b Wageningen University and Research, Quantitative Veterinary Epidemiology, Wageningen, The Netherlands c Inserm, Sorbonne Université, Institut Pierre Louis d’Epidémiologie et de Santé Publique (IPLESP), F-75012, Paris, France d Wageningen Bioveterinary Research, Lelystad, The Netherlands e Laboratory of Virology, Wageningen University & Research, Wageningen, The Netherlands
Keywords : ecology ; mathematical model ; mosquito-borne disease
Abstract: Rift Valley fever is a viral, mosquito-borne, zoonotic disease transmitted to sheep, cattle, goats, and ultimately, humans. Initially constrained to eastern and southern Africa, it is now present in most of the continent including the south west Indian Ocean islands, and has more recently spread to western Asia.
It is still unclear whether some livestock species play a more prominent role in Rift Valley fever virus (RVFV) transmission than others. It has been pointed out that trophic preferences of vectors, as well as husbandry and trading practices, are important to consider. But at the individual scale, there is a critical knowledge gap regarding the quantification of different host species infectiousness. This issue comes down to determining patterns of viral load dynamics in different susceptible species, and the associated probability to infect mosquitoes, which we aim to assess here.
We developed a mechanistic, compartmental, within-host model, representing the infection of target cells and the subsequent production of viral particles, not all of which are infectious. We also reviewed the literature to study the relationship between infectious titers and transmission to mosquitoes.
We fitted this model to time-series of total viral loads (RT-qPCR) and infectious titers (TCID50), measured during experimental RVFV challenge infections performed on calves, lambs, and young goats. We compared the cell-level basic reproduction number and mean generation time, between host species. We then computed the overall infectiousness of these species over the course of their infection, using the dose-response curve fitted to literature data.
We find that lambs have the highest infectiousness to mosquitoes, due to higher peak viremia and a longer infection. Differences between Aedes and Culex spp. infection rates were significant, and further studies should investigate how this impacts transmission rates. Exploring the effect of these results at the population scale could help design targeted control strategies.
46
Transport and reactivity of dissolved oxygen in fractured- bedrock aquifers
Ivan Osorio * a , Camille Bouchez a, Eliot Chattona, Julien Farasin a, Thierry Labasque a, Nicolas Lavenant a, Laurent Longuevergne a, Tanguy Le Borgne a a*UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France
Keywords: Dissolved Oxygen, Biogeochemical Reactivity, Geosciences.
Abstract: The persistence of dissolved oxygen (DO) in deep groundwater, sustains microbial life and biogeochemical reactivity, with potential impacts on large scale nutrient cycling. In aquifers, DO distribution is often heterogeneous and intermittent, but the driving factors of this variation remain poorly constrained. This study is based in two comparable fractured-bedrock catchments in Brittany, a Natural-Flow Regime (NFR) and a Pumping Regime (PR) catchment. Multi-parameter borehole-logs, groundwater residence-time tracers (CFC and 36퐶푙 ), dissolved gases, cations and anions concentrations were analyzed over 34 piezometers located both in recharge and discharge zones of the catchments. Opposing gradients of DO and dissolved iron concentrations show that, at catchment-scale, DO reactivity is closely linked to Fe(II) oxidation. The depth distribution of DO concentrations depends on groundwater flow regime. In the NFR catchment, DO is readily consumed in the first 70 m below surface. DO concentrations are shaped by a different chemical reactivity linked to the average weathering- front’s depth. Conversely, in the PR catchment DO spreads over a wider range of depths with detectable DO concentrations as deep as 300 m. Resulting from the competitive effects of transport and reactivity, the observed distribution of DO concentrations with depth was modelled with an analytical solution of a first-order reactive- transport model, which allowed constraining Damköhler numbers (퐷푎) related to DO in groundwater. DO concentrations in the NFR catchment are transport-limited (퐷푎 > 1): reaction rates are faster than transport ones and DO is consummed at shallow depths. On the other hand, stronger hydraulic gradients in the PR catchment enhance advection velocities and the DO distribution becomes reaction-limited. The present study shows how the groundwater flow regime impacts the distribution of DO in the deep Critical Zone, as it affects the balance between transport and reactive processes. Enhanced hydraulic gradients under pumping conditions or preferential transport through fractures allow deep oxygen delivery with potential impacts on biogeochemical reactivity and microaerobic microbial hot-spots formation in subsurface.
47
Role of nitrogen in the plant-fungal pathogen interaction during seedling establishment
Thibault Barrit*, Elisabeth Planchet, Claire Campion, Béatrice Teulat
Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
Keywords: Agronomy, Nitrogen, Plant-pathogen interactions
Abstract: Seed germination and seedling growth are early phases of plant development highly susceptible to environmental factors such as soil nitrogen availability or presence of seed- borne pathogens. The development of a more resilient agriculture creates a real interest in studying the role of nitrogen fertilization on plant-fungal pathogen interactions during seedling establishment. Indeed, nitrogen plays a central role in these interactions, not only as an essential nutrient for the development of plants and fungi, but also as a constituent of many plant defense molecules. Nitrogen can, depending on the pathosystem and the forms it takes (ammonium, nitrate, amino acids), favor either the plant or the fungus. In addition, the role of nitrogen in these interactions has never been studied during seed germination and seedling development. In this context, this work aims at studying the role of nitrogen in the interaction between Arabidopsis thaliana and Alternaria brassicicola, a seed transmitted necrotrophic fungus. For this, a new in vitro pathosystem was developed, allowing the study of seed germination, and the accurate determination of seedling growth characteristics (both on shoot and root parts) and symptoms, using different concentrations and forms of nitrogen (ammonium or nitrate) on a panel of genotypes presenting contrasting susceptibility to the fungus. While the presence of fungus didn’t affect seed germination, the nitrogen medium had an effect, with seeds germinating faster on ammonium than on nitrate. The seedling development was strongly and negatively affected by the presence of the fungus. However, the seedlings grown in nitrate condition were more resistant to the fungus than those cultivated in ammonium condition, which differs from what is observed with adult plants.
48 Sequential natural deep eutectic solvents pretreatment/water extraction: a novel way to extract and select pectin according to its main structural domain
Chen Mingrui*, Lahaye Marc
INRAe, UR BIA, F-44316, Nantes, France
Keywords: Natural deep eutectic solvent, pectin extraction, Alimentation
Abstract: As a widely produced and processed fruit in the world, apple pomace is a traditional source of pectin. Natural deep eutectic solvents (NADES) formed by hydrogen bonding acceptor and hydrogen bonding donor metabolites emerged as innovative solvents for extracting diverse molecules from biomass and were explored for extracting polysaccharides from food related wastes. In the present study, to establish a greener biorefinery process of apple pomace, pectin from the by-product was sequentially pretreated with three different natural deep eutectic solvents (NADES, choline chloride (CC): glycerol (G); CC: lactic acid (LA); potassium carbonate (K): G) prior to hot water extraction. Moreover, classical extraction methods (including water, mineral acid, chelating agents) were realized as a mean of comparison. The extraction yield and monosaccharides composition were analyzed to assess extraction efficiency. The molecular weight distribution and degree of esterification of pectin recovered were characterized. Lastly, the cell wall structural changes of residual pomace from different NADESs pretreatment/water extraction method were characterized by CP/MAS 13C NMR spectroscopy. Results showed that the highest pectin yield was recovered by sequential NADES pretreatment/hot water extraction. They revealed a synergistic effect of CC:G and CC:LA - sequential pretreatment on pectin yield. The effect of individual NADES components together with ion exchange were proposed to change cell wall organization to the benefit of water diffusion and pectin extraction. Pectin extracted following CC:G pretreatment was enriched in homogalacturonan (HG) structural domains while that recovered after CC:LA and K:G pretreatments was enriched in rhamnogalacturonan I (RGI) domains. RGI galactan and arabinan side chains were degraded to various degree by different NADES pretreatment. CC:G and CC:LA pretreatments followed by hot water extraction afforded to recover high molecular weight (MW) and high methylesterified pectin, while saponification occurring 13 퐻 during K:G pretreatment led to low MW and low methylesterified pectin. The C ssNMR 푇1p and 푇퐻퐻 parameters indicated a reorganization of cellulose in the residues following extraction of pectin, notably after alkaline K:G pretreatment/water extraction. Hence, sequential NADES pretreatments/water extraction represents a "green" alternative to mild mineral acid to extract pectin and to select for pectin according to their main structures, while the residual pomace can be further sources of valuable compounds and polymers.
49
Decrypting the mechanisms of host recognition and acceptance by a phytophagous insect
Kathleen Menacera*, Maxime R. Hervéa and Anne Marie Corteseroa a* IGEPP-UMR 1349, INRAE, Institut Agro, Univ Rennes 1, 35000 Rennes, France
Keywords: ecology, plant-insect interactions, host recognition
Abstract: In phytophagous insects, key behaviors that influence insect fitness such as feeding, mating and oviposition are influenced by plant-related cues. Along evolutionary times, the majority of these phytophagous insects have reduced their host range, leading to a specialization in the exploitation of one plant family or even few species. Some insects have even developed a preference for a given species or between different genotypes of the same species. Specialized phytophagous insects have therefore developed the ability to detect and recognize distance and contact chemical cues produced and emitted by the plants of their host range. This recognition is partly based on the presence of host-characteristic chemical compounds (qualitative aspect) but also on specific relative proportions of different compounds (quantitative aspect). However, the extreme complexity of chemical blends produced by plants remains a major difficulty in the comprehension of the quantitative dimension of host recognition processes. This PhD project aims to study the quantitative dimension of host recognition processes in phytophagous insect by focusing on a Brassicaceae specialist, the cabbage root fly (Delia radicum) and three of its host species: broccoli (Brassica oleracea), white mustard (Sinapis alba) and Chinese cabbage (Brassica rapa). Distance recognition is currently studied through olfactometry experiments, which assess host plant attractiveness for the insects. In addition, a device allowing the capture of volatile compounds is being designed, which extracts the olfactory message produced by the host plants. To study contact acceptance, oviposition experiments have been performed and have shown a gradient of female preference. A whole- plant development experiment was also conducted to study the relationship between female preference and offspring performance. Moreover, two electrophysiological techniques coupled to analytical techniques (GC-EAD/GC-MS and EAG) allowed showing the females’ ability to detect several molecules present in the blend of the three tested host plant species. Finally, in order to identify the nature and proportions of the molecules acting as cues, different approaches specific to each type of cues (volatile or contact) are being developed. These will allow fractionating the blend of plant molecules and testing the effect of the proportions of these molecules on the host plant selection behavior.
50
Oral Presentation 2 (O2) – 30th June
Session 3 (O2S3)
51
Modeling plant-soil systems using Structural Equation Models
Sébastian Mira1, 3*, Mathieu Emily2, Guillaume Gasc3, Edith Le Cadre1
1 UMR SAS, INRAE, Institut Agro, INRAE, 35042 Rennes, France
2 Institut Agro, CNRS, Univ Rennes, IRMAR [(Institut de Recherche Mathématique de Rennes)] UMR 6625, 35000 Rennes, France
3 EUREDEN Innovation, 29206 Landerneau, France
Keywords: Ecology, Rhizosphere, Plant functional traits Abstract: In a context of agroecological transition, plant-soil studies may help to understand complex interactions between roots and rhizosphere enhancing plant performances. Indeed, the volume of soil influenced by root activity, called the rhizosphere, is a vital interface for plants to acquire resources and to enhance plant health thanks to the plant microbiota, and is altered by the plant itself and many other biotic and abiotic factors. In addition to the difficulty of rhizosphere soil sampling, the rhizosphere involves complex root-soil interactions challenging our ability to understand plant-soil systems. Coupled to the impact of farming practices on these interactions, agroecological research should address new statistical tools able to model the complexity of plant-soil systems. Recent studies using Structural Equation Modelling (SEM) demonstrated the value of this statistical tool to explore complex ecological interactions in holistic approaches by the identification of causal links between latent variables of interest (Lamb et al., 2011; Cantarel et al., 2015; Schmidt et al., 2019). We conducted a controlled experiment in order to measure variability in plant performances due to plant-soil interactions only. SEM was used to describe causal relationships between wheat performances, root functional traits and rhizosphere properties. Our study revealed the potential of SEM in modeling complex systems and highlighted the influence of the rhizosphere on plant performances. These results pave the way for future on-field experimentations of plant-soil studies.
52
Synoptic 3D landslide volume calculation from repeat LiDAR data
Thomas Bernard, Dimitri Lague, Philippe Steer UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France
Keywords: Geosciences, Landslides, LiDAR
Abstract:
Efficient and robust landslide mapping and volume estimation is essential to rapidly infer landslide spatial distribution, to quantify the role of triggering events on landscape changes and to assess direct and secondary landslide-related geomorphic hazards. Many efforts have been made to develop landslide mapping methods, based on 2D satellite or aerial images, and to constrain the empirical volume-area (V-A) relationship allowing in turn to offer indirect estimates of landslide volume. Despite these efforts, major issues remain including the uncertainty of the V-A scaling, landslide amalgamation and the under-detection of landslides. To address these issues, we propose a new semi-automatic 3D point cloud differencing method to detect geomorphic changes, obtain robust landslide inventories with an uncertainty metric and directly measure the volume and geometric properties of landslides. This method is based on the M3C2 algorithm and was applied to a multi-temporal airborne LiDAR dataset of the Kaikoura region, New Zealand, following the Mw 7.8 earthquake of 14 November 2016. In a 5 km² area, our 3D workflow detects 524 landslide sources and 304 deposits with a minimum size of 20 m² and a total volume of 752,616 ± 154,165 m3 and 949,742 ± 150,014 m3, respectively. Geometric properties of the 3D inventory, including the V-A relationship, are consistent with previous results. A 2D inventory hand-crafted from aerial image comparison only identified 258 landslide scars severely underestimates the total area and volume of 3D detected sources by 75 % and 60 %, respectively. Detection and delimitation errors in 2D occurs in areas with limited texture change and at the transition between sources and deposits that the 3D method accurately captures. Large rotational/translational landslides are missed in the 2D inventory owing to the dominant vertical topographic change. Our data show a systematic size- dependent under-detection in the 2D inventory below 200 m² that may explain all or part of the classical rollover observed in 2D landslide source area distribution. We demonstrate that 3D point cloud differencing offers a greater sensitivity to detect small changes than a classical difference of digital elevation models. Our results underline the vast potential of 3D-derived inventories in quantifying the impact of extreme events on topographic change in regions prone to landsliding and to explore in new ways the scaling properties of landslides.
53
SCOOP12 moderates cell elongation by controlling ROS homeostasis and promotes plant defenses through a wide transcriptional impact in Arabidopsis
Marie-Charlotte Guillou*a, Emilie Vergnea, Sophie Aligona, Sandra Pelletiera, Kay Gullyc, Philippe Grappina, Salem Chaboutb, Gregory Mouilleb, David Rousseaua, Elia Stahlc, Philippe Reymondc, Elisabeth Jametd, Françoise Montricharda, Sébastien Aubourga, Jean-Pierre Renoua*. 1 IRHS (Institut de Recherche en Horticulture et Semences), UMR 1345, Université d’Angers, INRAE, Institut Agro, SFR 4207 QuaSaV, F-49071, Beaucouzé, France. 2 IJPB (Institut Jean-Pierre Bourgin), INRA Centre de Versailles-Grignon, Route de St-Cyr, 78026 Versailles Cedex, France. 3 Department of Plant Molecular Biology, University of Lausanne, CH-1015 Lausanne, Switzerland 4 Université de Toulouse ; UPS, UMR 5546, Laboratoire de Recherche en Sciences Végétales, BP 42617 Auzeville, F-31326 Castanet-Tolosan, France.
Keywords: Secreted peptides, root elongation, ROS homeostasis, glucosinolates, agronomy
Abstract: Plant development and stress response are controlled by complex signaling networks and regulatory mechanisms. Many actors are involved and small secreted peptides have stimulated research thanks to their putative role in both pathways. Nevertheless, the biological functions of many of them are still unknown. The PROSCOOP family encodes precursors of secreted peptides, names SCOOPs, in Arabidopsis thaliana. Among them, the SCOOP12 peptide regulates the defense response through a strong induction of reactive oxygen species (ROS) in the aerial parts, in presence of pathogens. In this study, we assumed that this ROS regulation by SCOOP12 was also involved in the control of root development and we report a series of signaling events induced by SCOOP12 activity. We compared the metabolic pathways induced by the PROSCOOP12 precursor between proscoop12 mutant and wild-type and we showed that the longer primary root phenotype of proscoop12 is due to a greater cell size in the elongation .- zone (EZ). It is also strongly correlated with a higher superoxide anion (O2 ) accumulation in the meristematic zone (MZ) and a lower hydrogen peroxide (H2O2) accumulation in the EZ, highlighting the link between the gene and the ROS homeostasis in root development. The mutation also decreased the expression of key genes of the glucosinolate pathway and made the mutant more susceptible to generalist insects. On the contrary, the shorter roots phenotype induced by the scoop12 treatment was caused by a disruption of the MZ structure and a higher H2O2 accumulation, which is supported by significant modifications of the cell wall structure. Finally, SCOOP12 application induced a massive transcriptional reprogramming as the activation of many defense genes of ethylene, jasmonic acid, salicylic acid and glucosinolate pathways. This study points the pleiotropic effect of SCOOP12 and demonstrates the need for the plant to control its expression in order to tune both its development and defense responses
54 Effect of the distance from trophic resources provided to parasitoids on the regulation of aphid pests in a plum- tree orchard in Chile
Louise Léraulta*, Elsa Clavela, Cinthya Villegasb, Nuri Cabrerab, Manuel Plantegenesta, Bruno Jalouxa, Blas Lavanderob a* UMR IGEPP, Université Rennes 1 & Institut Agro, Agrocampus Ouest, Rennes/Angers, France b Laboratorio de Control Biológico, Instituto de Ciencias Biológicas, Universidad de Talca, Chile
Keywords: ecology, intercropping, pest regulation
Abstract: The conservation of parasitoids populations by providing complementary or supplementary resources is considered as an alternative to pesticides in diverse cropping systems. The efficiency of these natural enemies depends on the diversity, abundance and spatial-temporal distribution of their trophic resources: hosts (pest or alternative) and food (nectar, honeydew). The hypothesis stating that providing these resources improves parasitism has been tested many times, sometimes confirmed, sometimes refuted. A decrease of the positive effect of a provided resource on the attraction and maintenance of parasitoids is often observed with an increase of the distance from that resource, but is it not well known how far from the resource its effect can still be detected when there is one, nor if it can be complementary to another resource’s effect. In this study, the effect of the distance from two types of provided resources on the populations of parasitoids and their parasitism activity has been evaluated, along with the possible complementarity of those two trophic resources: alternative aphid hosts, and extrafloral nectar. Three modalities of two intercrops were replicated three times in the same inter-row: pure oats (for alternative hosts), pure vetch (for nectar), and a total mixture of both. We checked for the presence of aphids on oats, and the release of extrafloral nectar on vetch. On plum-trees, the incidence of aphids and an estimation of the parasitism were measured, by observation and by using exclusion cages, at four distances from the central inter-row. Results show that, despite the function of trophic resource providers being effective for the intercrops chosen, no general effect of the modality nor the distance from the inter-row was observed. This suggests, among other possible explanations, that parasitoids might not change from a vegetation level to another, and that they seem to be relying on other carbohydrate resources than extrafloral nectar in the orchard to survive. This experiment underlines the importance to study the spatial range of the effect of a provided resource on natural enemies.
55
Estimation of crossbreed beef half-carcass chemical composition by dual-energy X-ray absorptiometry (DXA) scan of half-carcass or 11th rib
Caroline Xavier*a,b, Isabelle Morela, Raphael Siegenthalera, Frigga Dohme-Meiera, Yannick Le Cozlerb, Sylvain Lercha a Agroscope, Ruminants Research Unit, Tioleyre 4, 1725 Posieux, Switzerland, bPEGASE, INRAE-Institut Agro, 16 Le Clos, 35590 Saint Gilles, France;
Keywords: Agronomy, carcass composition, imaging technic
Abstract: The aim was to estimate beef cold half carcass (CHC) composition from dual X-ray absorptiometry (DXA) scans of either CHC or 11th rib. Forty-two left CHC (94±49 kg, 17 to 157 kg) and their 11th rib were obtained from bulls of the three most Swiss-widespread crossbreeds in dairy herds (♀ Brown Swiss x ♂ Angus, Limousin or Simmental). Lean, fat, bone mineral content (BMC) and total masses of CHC and 11th rib were determined with a DXA scanner (iLunar, GE, “Right Arm” mode). CHC was then grinded, before chemical analyses (lipid: Soxhlet, protein: Dumas, ash: 550°C). Regressions (R software, v3.6.3) were tested between the CHC and 11th rib DXA variates and CHC chemical composition. Cold half carcass contained 11±8.3 (0.8 to 29.1) kg lipid, 18±9.2 (3.1 to 30.6) kg protein and 4±1.8 (0.8 to 6.5) kg ash. The CHC weight explained a large part of chemical component masses (lipid: R²=0.884, residual coefficient of variation (rCV)=25.3%; protein R²=0.996, rCV=3.4%; ash R²=0.971, rCV=7.8%). It was also well estimated from CHC DXA total mass with a R2 of 0.999 (rCV=1.3%). Estimations of lipid, protein and ash masses with a single CHC DXA variate were precise with fat (R²=0.983, rCV=9.7%), lean (R²=0.996, rCV=3.4%) and BMC (R²=0.975, rCV=7.8%), respectively. Multiple models were even more accurate with CHC DXA fat, lean and BMC masses for lipid mass (R2=0.990, rCV=7.7%), CHC weight and DXA fat mass for protein mass (R2=0.997 and rCV=2.9%), and CHC weight, DXA fat and BMC masses for ash mass (R2=0.979 and rCV=7.2%). Multiple regressions for estimations of CHC lipid and protein masses from 11th rib DXA variates provided R2 very close to the previous ones established from CHC DXA scan. Nonetheless, the rCV was twice higher for lipid mass (rCV=14.8%), whereas it remained equal for protein mass (rCV=2.9%). Crossbreed effect was rarely significant in models and only improved slightly their accuracy (maximum of +1% for the R2 and -1.5% for rCV for CHC lipid mass from 11th rib DXA variates). A single rib cut DXA scan appears to be a promising method to estimate carcass composition in a simple, quick, reproducible, accurate and non-destructive way.
56
Molecular networking of tandem ion mobility data and its implications for glycomics
Simon Olliviera,b*, Mathieu Fanuela,b, David Ropartza,b, Hélène Rogniauxa,b a INRAE, UR BIA, F-44316 Nantes b INRAE, PROBE research infrastructure, BIBS facility, F-44316 Nantes
Keywords: Alimentation; Chemistry; Carbohydrates
Abstract:
Introduction – Data organization through molecular networking (MN) has been used in “omics” sciences over the past years as a way to efficiently mine the massive amount of spectral information produced by tandem mass spectrometry (MS). However, glycomics lags a step behind: carbohydrate structures involve numerous levels of isomerism, making MS and tandem MS blind to many key structural features of glycans. This roadblock can in part be alleviated with gas-phase ion mobility spectrometry (IMS), a method highly sensitive to isomerism. Notably, the last generation of high-resolution IMS-MS spectrometers now offers the possibility to perform tandem IMS or IMS/IMS. We will show how IMS/IMS can be integrated in the MN strategy. Methods – We analyzed a set of oligosaccharide standards, representative of plant carbohydrates, using IMS/IMS on a Select Series Cyclic IMS mass spectrometer (Waters, Wilmslow, UK). Briefly, an IMS/IMS experiment consists of: (i) selecting a precursor ion according to its mass and ion mobility arrival time, (ii) collisionally fragmenting the precursor, and (iii) performing ion mobility analysis of the fragments. This generates an ion mobility spectrum, which contains ion mobility data for all the fragments. The experiment- dependent drift time values of the fragments were further calibrated to give repeatable collision cross section (CCS) values, in Ų, which represent the surface of an ion that interacts with the buffer gas during IM separation. IMS/IMS spectra containing CCS and intensity values could then be exported to the GNPS platform (https://gnps.ucsd.edu) for MN analysis. Results – We built molecular networks using our IMS/IMS-based approach and the classical MS/MS-based approach. The classical approach gave minimal information about the structure of the oligosaccharides, the clustering being based solely on the nature of the subunits (pentose or hexose). In contrast, our ion mobility- molecular networking strategy generated structurally relevant clusters that accurately reflected the structural diversity of the oligosaccharide standards and their isomerism, with regard to the nature of both the subunits and the glycosidic bond. Oligosaccharides indeed clustered according the main pattern in their backbone, regardless of lateral branching by other subunits. Conclusions – We present a novel workflow for the organization of IMS/IMS spectra that should be of future use in the field of glycomics. We demonstrate that—when it comes to oligosaccharides and their numerous levels of isomerisms—molecular networks based on IMS/IMS spectra are widely superior to classical MS/MS-based networks to sort and organize molecules with a high degree of structural relevance.
57
Exploiting favourable alleles in apple genetic resources using genomic selection
Xabi Cazenavea*, Charles-Eric Durela, Hélène Murantya a IRHS, INRAE, Agrocampus-Ouest, Université d’Angers, SFR 4207 QuaSaV, 49071, Beaucouzé, France
Keywords: Agronomy, apple breeding, genomic selection
Abstract: Although more than 10,000 apple cultivars have been documented worldwide, modern commercial apple production is dominated by only a few cultivars. Broadening the genetic diversity used in breeding programs thus appears as a necessity in order to reduce the vulnerability resulting from genetic uniformity. In this context, the identification of genetic resources that contain favourable alleles absent or rare in elite material is of primary importance for breeders. Harnessing this genetic diversity will probably require several generations of crosses starting from genetic resources before parents carrying the identified favourable alleles are ready to be used in breeding programs. In order to speed up the process and efficiently transfer these alleles, we propose to use genomic selection, a breeding approach that aims to estimate the breeding value of selection candidates using only genetic markers information. To do so, apple genetic resources (i.e. old varieties), elite material and hybrids between them have been genotyped and phenotyped so that prediction equations can be developed in order to predict the potential of selection candidates. These equations were built within and across populations and the predictive ability of such equations was compared to the one obtained with equations built with both. In this last case, the proportion of each population that would allow the highest predictive ability was also investigated. To further improve the choice of the individuals used to build the prediction equations, various optimisation algorithms were also used before estimating these predictive abilities. Overall, the obtained results should help us identify breeding strategies intended to efficiently transfer interesting alleles from genetic resources into elite material.
58
Oral Presentation 2 (O2) – 30th June
Session 4 (O2S4)
59 Effects of acid environment on digestate and reconstituted ration in a batch hydrolysis/acidogenic reactor
Gauthier Gensollena, Pascal Peub, Anne-Marie Pourcherc, Anne-Laure Duedald
a ED EGAAL, AgroCampus Ouest, 65 Rue de Saint-Brieuc, 35042 Rennes, France b, c INRAE Bretagne-Normandie, UR OPAALE, 17 avenue de Cucillé, 35 044 Rennes Cedex, France d Evalor, 1 Rue Georges Guynemer, 22190 Plérin, France
Keywords: Two-step anaerobic digestion, Pre-treatment, Agronomy Abstract: This R&D project focuses on bio resources’ waste management such as agricultural crops, livestock manure or industrial waste to produce energy generated from bio-methane. The studied process is an innovative two step- anaerobic digestion engineered by Evalor (Plérin, France) called BOOST©. It is composed of a classic anaerobic digester with a hydrolysis/acidogenic tank placed upwind. In addition, part of the main digester digestate sludge recirculates to the hydrolysis/acidogenic tank to mix dry substrates in liquid phase (dry matter content calculated around 10 %). The main characteristics of the BOOST© tank are an acid environment and a low hydraulic retention time. Moreover, the hydrolysis/acidogenic tank allows a 15 % increase of the global yield in term of bio-methane production. Two hypotheses are formulated to explain this global yield increase: i) The sludge digestate exposed to an acid environment allows the recovery of some organic material assumed inert ii) There is an acid pre-treatment on the solid substrates. In order to test these hypotheses, the following experiments reproduce these conditions in a batch reactor perfectly stirred. First, the sludge digestate from the recirculation and then the substrates with the digestate are exposed to a defined pH range for a period equal to one hydraulic retention time. For the first experiment, the acidification process on the digestate shows no change. Indeed, Volatile Fatty Acids (VFA) are stable (mostly acetic and propionic acid around 1 g/L) and Bio-Methane Potential (BMP) before and after the acidification are identical. It suggests that an acid environment does not allow to recover some inert organic material and that the change of pH does not change the sludge’s biological behaviour. For the second experiment, the acidification process shows a significant impact on the biological behaviour. Indeed, after less than a day of pre-treatment, lactic acid is generated (up to 15 g/L) accompanied by hydrogen production in the biogas (up to 22 %). This sudden production lasts 18 hours leading to the lactic acid consumption to form butyric and acetic acid in a 0.5 molar ratio. At this range of pH, this ratio is well-known in scientific literature [1] and is a fermentation indicator [2]. Unfortunately, the acid pre-treatment does not affect the BMP. Finally, it is not possible to conclude regarding the effect of a physicochemical pre-treatment. In conclusion, the digestate obtained thanks to the recirculation does not increase the global yield but dilutes solid substrates and brings microorganisms into the hydrolysis/acidogenic tank. Regarding the substrates, the pH effect should be studied in terms of biology even if it is now possible to conclude that the dark fermentation step allows bio-hydrogen production [2]. Therefore, further analysis on different pH range will be carried out within this thesis completion.
References: [1] Anish Ghimire. Dark fermentative biohydrogen production from organic waste and application of by-products in a biorefinery concept. Material chemistry. Université Paris-Est, 2015.
[2] Ding, L., Chen, Y., Xu, Y., & Hu, B. (2021). Improving treatment capacity and process stability via a two- stage anaerobic digestion of food waste combining solid-state acidogenesis and leachate methanogenesis/recirculation. Journal of Cleaner Production, 279.
60
Single seed microbiota: dynamics and transmission from mother plant to seedling
Guillaume Chesneaua*, Béatrice Larocheb, Anne Préveauxa, Coralie Maraisa, Martial Brianda, Brice Marolleaua, Marie Simonina, Matthieu Barreta a* IRHS, Agrocampus-Ouest, INRAE, Université d’Angers, SFR 4207 QuaSaV, 42 rue Georges Morel, 49071 BEAUCOUZE CEDEX, France. b Département de Mathématiques Informatiques Appliquées, INRAE, Jouy-en-Josas, France
Keywords: Ecology, Seed microbiota, Bacterial transmission
Abstract: Seed microbiota contributes to the improvement of seed vigor and the development of healthy seedlings. These two steps are economically essential for crop establishment and future agricultural yields. To date, improving crop establishment via modification of seed microbiota composition require to gain basic understanding of the origin and transmission pathways (Floral, systemic or external) of seed associated taxa. In addition, knowledge’s on ecological processes and the order and timing of microbial taxa immigration during seed microbiota assembly from the mother plant to the seedling stay understudied and need to be investigated. In this study, we assessed the dynamic of seed microbiota assembly of common bean (Phaseolus vulgaris), and the influence of seed microbiota on seedling phenotype. In a first step, we estimated the structure of bean (n=600) individual seed bacterial communities during four seed developmental stages. We assessed the relative contribution of stochastic and deterministic processes with null community model, and evaluate the bacterial seed transmission routes through sampling of flowers, stems, and atmosphere. In a second step we studied the microbiota transmission from seed to seedling, to finally assess the impact of seed microbiota on seedling phenotype. Origin of seed-associated taxa was mainly associated with the external environment. An average of four bacterial taxa were detected per individual seed, with a single dominant taxon per seed representing between 75 to 100% of all reads. Variation of seed bacterial community structure was not only important between plants but also within the same plant whatever the stage of development considered. B-null deviation measure indicated that selective processes were primary driving seed bacterial communities structure at the plant level at each seed developmental stage. Seed microbiota composition do not differ according to the seedling phenotype in contrary to individual taxa. We confirmed the detrimental impact of an ASV of Pantoea agglomerans and the beneficial impact of two ASVs of Firmicutes on seedling phenotype via in vitro inoculation on seeds. In conclusion, seeds are endowed with a single dominant bacterial taxon, whose phylogenetic identity is highly variable. Even if bacterial transmission from seed to seedling is low, two taxa (Firmicutes) showed a significant beneficial impact on the seedling phenotype and are promising candidates for the design of seed-microbial consortia to improve plant growth and health.
61 CAKERS – Cake reduced in sugar sweet and sour
Juliette Palierab*, Alain Le-Bailb, Catherine Loiselb, Patricia Le-Baila
*presentating PhD student a INRAE UR-1268 Biopolymères Interactions et Assemblages, 3 impasse Yvette Cauchois La Géraudière, CS 71627, 44316 Nantes Cedex, France b Oniris, UMR 6144 GEPEA CNRS, Nantes, Rue de la Géraudière, CS 82225, 44322 Nantes, France
Keywords: Alimentation, pound cake, sugar reduction
Abstract: Sugar has become an ingredient “under high oversight”. It is necessary for the body and in reasonable quantities for a balanced diet. However, its excessive use by the food industry has led to the issuance of nutritional recommendations and consumption limits. A great challenge for the food industry is therefore to reduce the sugar content in products without adversely affecting the taste or altering the functionality of the product. Cakes contain about 25% sugar and sucrose plays a very important functional role in the manufacture of cakes, its reduction in the batter leads to a change in the rheology and to a drop in the gelatinization temperature of the starch. It will also increase aw with an increased risk of microbiological instability. This study aims to develop a cake reduced in sugar with a reduced caloric response. This main objective will be achieved by reformulating the cake with specific sweeteners and a bulking agent. A first originality of the project lies in the fact that the acidification of the cake will be targeted; this acidification will serve as a means to control the gelatinization temperature of the starch and reduce its depression when adding sweeteners potentially leading to a lower glycemic response and to extend the shelf life of the cake. However, acidification induces a premature reaction of sodium bicarbonate (blowing agent) which will lead to dense products. The second originality of this thesis remains in the use of a gas pressure kneading process which makes it possible to dispense with baking powders. The first task was to remove the baking powders. To do this, the paste was mixed using three pressurized gases: air, nitrogen, and carbon dioxide (CO2), all of which are inert gases. The mixing was carried out in batch using a prototype mixer (VMI -France). Several parameters were studied to compare cakes with and without baking powders. Mixing in air or under nitrogen does not seem to improve the aeration of the cakes. On the other hand, CO2 cakes have an interesting volume and porosity. The second task was to reformulate a four-quarter dough to obtain an acidified lemon cake thanks to the mixture of the dough under CO2 pressure and without baking powder. The acidic cake was then reduced to sugar by replacing the sugar with maltitol and a bulking agent. The batter properties and cake structure and texture have been studied.
62 Specialized metabolism in Brassica napus: a multi-omic approach for the characterization of phytochemical diversity, its genetic determinants and its regulation by pathogen infection
Anani Amegan Missinou *a, Anne Levrel a, Youcef Haddad a, Nathalie Marnet b, Mélanie Lagarrigue-Reboutier c, Régis Lavigne c, Yann Guitton e, Clément Orione f, Thomas Delhaye d, Julie Ferreira de Carvalho a, Anne Laperche a, Alain Bouchereau ab, Régine Delourme a, Anne Siegel g, Maria Manzanares-Dauleux a, Antoine Gravot ab a UMR1349 IGEPP, Institute for Genetics, Environment and Plant. Protection, Agrocampus ouest, INRAE, Le Rheu, France b Plateform P2M2, Profiling Platform of Metabolic and Metabolomic, UMR1349 IGEPP, INRAE, Le Rheu, France c Plateform PROTIM, Proteomes and Images, IRSET, INSERM U1085, University of Rennes 1, Rennes, France d Plateform M²ARS, Manufacturing Measurement Analysis of Radiating Systems, UMR CNRS 6164, Rennes, France e UMR1329 LABERCA, Laboratory for the Study of Residues and Contaminants in Foods, INRAE, ONIRIS, Nantes, France f Plateform CRMPO, Regional Centre for Physical Measurements of Western, University of Rennes 1, Rennes, France g DYLISS, Dynamics, Logics and Inference for biological Systems and Sequences, IRISA, CNRS, INRIA, Rennes, France.
Keywords: Ecology, specialized metabolism, fungus infection Abstract: A key challenge in plant chemical ecology in the post-genomic era is to extend our knowledge of plant specialized metabolite (SM) diversity, and to improve the identification of genomic determinants influencing their biosynthesis in order to increase our understanding of their roles in biotic interactions. In the crop Brassica napus (oilseed rape), defensive phytochemicals are only partially characterized and offer substantial differences with the closely related model of Arabidopsis. Improving our understanding of the SM repertoire and its regulation in B. napus, are needed to unlock functional genomics studies on biological interactions in this crop. In this work, a combination of metabolomics and genomics was used to investigate the chemical diversity and the factors involved in the constitutive and inducible regulation of secondary metabolites in roots, stems, and leaves of B. napus.
The first chapter was dedicated to the study of constitutively accumulated SM and their genetic control. A combination of liquid chromatography-tandem mass spectrometry (LC-MS) and purification/nuclear magnetic resonance strategies was used to develop a method for the profiling of 37 glucosinolates (GLSs) and 78 UV-absorbing compounds B. napus roots and leaves. This approach notably highlighted the importance of a series of previously not documented metabolites in the roots of B. napus, and will eventually enable the testing of biological activity of purified compounds. A metabolite-based genome-wide association study (mGWAS) of the control of these SMs among a panel of 300 accessions of B. napus identified quantitative trait locus (QTLs) of the genetic determinant. A bioinformatics approach is under way to search candidate genes or physically clustered biosynthetic genes at same chromosome and possibly included in these metabolic QTLs. In the second chapter, we tried to understand how B. napus establishes a chemical defense during stem infection by the fungus Leptosphaeria maculans (causal agent of Blackleg), by comparing responses in one partially resistant and in one susceptible B. napus variety. Targeted profiling of GLSs revealed a strong biosynthesis shift in favor of indole GLSs in these two groups, that was consistent with transcriptomics regulation of related biosynthetic genes. The complexity of metabolomic response to infection was complemented by untargeted LC-MS analysis. FBMN (feature-based molecular networking) annotation is in progress to characterize the series of previously unknown phytoalexins and identify resistant specific responses. Finally, a mass spectrometry imaging (MSI) approach on cross-sectioning infected stems revealed that metabolic responses are specific to areas surrounding necrosis, especially in moderately resistant genotypes, thus suggesting a potential role in the resistance to the Blackleg.
63
Coastal sand dune monitoring using hyperspectral and full-waveform LiDAR synchronized remote sensing: low vegetation cover classification and digital terrain model improvement Giovanni Frati1,2, Patrick Launeau1, Marc Robin3, Manuel Giraud1, Martin Juigner3, Françoise Debaine3, Cyril Michon2
1 Laboratoire de Planétologie et Géodynamique (LPG) CNRS: UMR6112, INSU, Université de Nantes, OSUNA, Université d’Angers 2 Rue de la Houssinière—BP 92208 44322 NANTES CEDEX 3 2 bd Lavoisier, CEDEX, 49045 Angers, France.
2 GEOFIT-Expert, 1 Route de Gachet, CEDEX 3, 44307 Nantes, France.
3 Institut de Géographie et d’Aménagement Régional de l’Université de Nantes (IGARUN/Géolittomer- UMR6554, LETG CNRS) CNRS: UMR6554 Chemin de la Censive du Tertre BP 81227, CEDEX, 44312 Nantes, France. Keywords: Geoscience; airborne remote-sensing ; coastal monitoring Abstract: The coastal sand dunes, formed by accumulation of aeolian sands taken from their associated beaches, are very important both for the preservation of the littoral itself and for the protection of the backcountry against marine hazards. The monitoring of these dunes, along the whole Pays-de-La-Loire coastline requires the accurate mapping of its morphology and its low vegetation cover, in order to assess sedimentary stocks/fluxes. Using an aircraft, 250 km of coast are acquired each year by combining 1) laser raging (LiDAR), which provides the light- vegetation-soil interaction’s height, with 2) hyperspectral imaging (HSI), given access to the surface mean physico-chemical properties for each pixel. In facts, the LiDAR 1064 nm laser scanner is aligned on the hyperspectral swath, making both following the same emergence angle. Signal (both spectral and ranging) shape variations were summarized into series of indices, then assemblies into a single pseudo-cube per acquisition year. These latter then served as inputs bases for a hierarchical classification, allowing the direct mapping of the main dunar structures and their associated vegetation cover, independently of the considered acquisition year. Results were then used to correct topographical errors induced by Ammophila arenaria, proxy of the white dune and principal actor of its stability, on the Digital Terrain Model (DTM). However, the small scale complexity of the imbrications between Ammophila arenaria, of the stabilized dune and Elymus farctus, of the incipient one, locally led few confusions. The use of the object-base would help to overcome this issue and improve the quality of coastaline monitoring.
64
In-depth analysis of the flax fibre intricate microstructure in relationship with ist mechanical behaviour
Emmanuelle Richelya*, Alexander Kaob, Hom Dhakalc, Alain Bourmaudd, Johnny Beaugranda, Sofiane Guessasmaa aUR1268 BIA. INRAE Nantes, France bElettra Sincrotrone Trieste, Italy cAMM Research Group, Portsmouth, United Kingdom dUniv. Bretagne Sud, UMR CNRS 6027, IRDL, Lorient, France
Keywords: flax, mechanical properties, agronomy
Abstract: This work investigates the relationships between the complex flax fibre microstructure and its mechanical behaviour under tensile testing. X-ray microtomography swept across the submicronic scales broadly defined the intricate shape of the flax fibre and its main internal porosity, the lumen. The tensile test results reveal a complex mechanical behaviour that is further implemented and investigated through a finite element model. Strongly linked to industrial development in the biocomposite field, plant fibres, and especially flax, require a deep understanding of the relationships between their submicronic structure and mechanical properties. Flax individual fibres are organized in bundles that are extracted from the stems by a mechanical process, and those fibre elements can be used for composite reinforcement. They exhibit an intricate and hierarchical structure leading to a complex mechanical response to external stresses. In this study, the relationships between the flax fibre structure and tensile performance is investigated. Some of the key links that are revealed are the sub-micronic porosity, the main internal porosity being the central lumen, and process-induced defects of the fibre microstructure. These are correlated to the tensile response of flax fibre using an original approach that combines experimental and numerical work conducted at the sub-micronic scale. In particular, a mechanical model is developed based on the finite element approach where the geometry of the fibre is embedded in the model using X-ray micro- tomography data at a voxel size as small as 150 nm. The model takes into account the experimentally determined structure and tensile behaviour of a high quality fibre batch. This work concludes on a better understanding of the tensile behaviour of unitary fibres if the submicronic structure of the fibre is fully considered. It opens the way to a more thriving investigation at the bundle scale.
65
Posters Presentation 2 (PS2) – 30th June
66
Nanoplastics' Behavior in Polar Waters: Modeling the Interface between Saltwater and Sea Ice
Pradel Alice*1,2, Gautier Maud1, Bavay Dominique1, Gigault Julien1,2
1 Univ Rennes, CNRS, Géosciences Rennes - UMR 6118, 35000 Rennes, France
2 TAKUVIK, CNRS, Université Laval – UMI 3376, Quebec, Canada
Keywords: Plastic debris, Arctic, Sea ice, Transfer, Geosciences
Abstract: Polar ecosystems play key roles in many Earth-system processes, such as the redistribution of particulate material throughout the water column and across ocean surfaces during the freeze-thaw cycles of sea ice. It has become clear that this particulate material now inevitably includes microplastics (1µm-5mm) and nanoplastics (<1µm). Indeed, during their long journey from continental source to the poles, plastic waste is degraded to particulate sizes. Once in polar seas, this degradation is enhanced by strong UV radiation. Microplastic concentrations in the Arctic ocean range from 102 to 103 particles per m3 and are expected to rise. In particular, the Barents and Greenland seas will form zones of plastic accumulation. Strikingly, microplastic concentrations in sea ice are consistently higher, by a factor approximately 100, compared to seawater. However, while nanoplastics could represent an important proportion of the ocean’s total plastic budget, their fate in polar waters remains unknown. This study provides the first mechanistic description of nanoplastic transfer between saltwater and ice. A freezing reactor was conceived which progressively and partially froze microplastic and nanoplastic dispersions, after which their affinity for ice and liquid was quantified. The particles used had different degrees of environmental relevance: spherical polystyrene (PS) with diameters 200 nm (nPSL-200), 350 nm (nPSL-350), PS particles with irregular shapes (nPS-360) as well as PS microplastics with sizes 150 to 400 µm (µPS). Contrary to microplastics, nanoplastics are strongly expulsed from ice. Concentrations of nanoplastics in ice is heterogenous, with accumulation zones in brine pockets. So, sea ice creates a medium-term sink for microplastics, but it accelerates nanoplastics’ journey down the water column. Microplastics and nanoplastics different behavior is explained by the colloidal properties of nanoplastics and highlights the fact that nanoplastics cannot be lumped into the same category as microplastics.
67
Multicriteria definition of small-scale biorefineries based on a statistical classification
Aicha Ait Sair1*, Franck Michaud2, Bernard Cathala1, Kamal Kansou1
1UR1268 BIA, INRAE, 44300, Nantes, France 2 Laboratoire Innovation Matériau Bois Habitat Apprentissage (LIMBHA), Ecole Supérieure du Bois, 7 rue Christian Pauc, 44306 Nantes, France
Keywords: small-scale biorefineries, classification, ecology
Abstract:
The concept of biorefinery is one of the pillars of the bioeconomy, which promotes the diversification of transformation paths of bioresources. It is in fact defined as the sustainable conversion of biomass into a multiple bio-based products. In that, it is a broad concept that encompasses a multitude of technologies, modalities and scales. Generally, the scale of a biorefinery is brought to its processing or production capacities. Other attempts linked the scale of a biorefinery to its economic viability. However, to distinguish small-scale biorefineries (SSB) from the large one remain challenging. In this paper, we propose a definition of the SSB based on a multi-factorial analysis using statistical approaches. The methodological approach consisted of collecting data on 15 operational biorefineries as case studies, the selection of the variables (investment cost, processing capacity, process complexity, mobility of the process, biomass type and added value) and their statistical analysis using factorial analysis of mixed data (FAMD) and hierarchical ascending clustering (HAC). It resulted in the clustering of biorefineries generating four clusters: The smallest scale, the small scale, the hybrid and the large scale. From that, we extracted that the small scale can be defined by a small investment cost (less than 2M€), a small processing capacity (less than 100t/day), with a low process complexity able to produce from low to high added value products. The mobility of the facilities is also a crucial element in defining the small scale, since it ensure the proximity to biomass providers, but built-on site plants respecting the above characteristics can be small-scale as well. In addition, we found that the scale of a biorefinery depend on a trade-off between the mobility, the process and the socio- economic context. This equilibrium is necessary for the biorefinery economic and sustainable viability. It is even more essential in the case of small-scale biorefineries, to encounter the effects of not benefitting from the economy of scale.
68
Screening and investigating starch structure and enzymatic degradability in a wheat MAGIC population
Yuzi Wanga*, Kamal Kansoua, Jean-Philippe Ralb, Luc Saulniera a* INRAE – Biopolymères Interactions Assemblages (UR1268), F-44300 Nantes, France b Commonwealth Scientific and Industrial Research Organization, GPO Box 1600, Canberra ACT 2601, Australia
Keywords: alimentation, starch hydrolysis, multivariate analysis
Abstract: Starch degradation is an important feature of starch processing both on nutritional or industrial aspects. Starch degradability can be impacted by starch structure and composition that is in turn influenced by genetic and environmental conditions. The common challenges faced by studies investigating the “structure-degradability” interaction include the experimental condition limiting the number of samples and the interdependency between the various structural features of native starch. This study aimed to tackle these two challenges by (1) developing a method allowing enzymatic accurate and reproduceable hydrolysis screening of large sample sets and (2) combining this method to a multivariate analysis to untangle the “structure-degradability” complexity. From a 4-way MAGIC (Multi-Allelic-Genetic-InterCross) population (CSIRO, Australia), 224 wheat starches from 156 cultivars were accessed for their structural attributes and degradation profiles, followed by a hierarchical clustering on principal components (HCPC) to explore the role of structural features in degradation. The results suggested that the enzymatic hydrolysis of MAGIC wheat starch was biphasic with degradability varied from 63.6% to 79.9%. The HCPC highlighted the impact of the combination between granule size distribution and amylopectin chain length distribution on degradation kinetics, as well as a negative correlation between amylose content and hydrolysis rate, which may therefore provide important information to improve starch selection for specific end-uses. 69
Understanding the compensatory mechanisms in resistant Anopheles gambiae AcerKis and KdrKis neurons is essential to adapt insecticide-based mosquito control
Stéphane Perrier1a, Eléonore Moreau1, Caroline Deshayes1, Fabrice Chandre2 & Bruno Lapied1*
1Laboratoire Signalisation Fonctionnelle des Canaux Ioniques et des Récepteurs (SiFCIR), UPRES EA 2647, USC INRAE 1330, SFR QUASAV 4207, UFR Sciences, Université d’Angers, 2 boulevard Lavoisier, 49045 Angers, cedex, France. 2MIVEGEC, UMR IRD 224-CNRS 5290-Université de Montpellier, 911 avenue Agropolis, 34394 Montpellier Cedex 05, France. a presenting 3rd year PhD student *Corresponding author: Prof. B. Lapied, laboratoire SiFCIR, UFR Sciences, 2 boulevard Lavoisier, 49045 Angers, cedex, France; E-mail adress : [email protected]
Keywords: Ecology, Mosquitoes, Anopheles gambiae, Vector control, Insecticide resistance
Abstract:
Malaria is mostly transmitted by Anopheles gambiae mosquitoes. It accounts for a total of about 405,000 deaths and 228 million contamination cases each year. Malaria transmission is controlled via the use of insecticide-treated bed nets (ITNs) integrated in insecticide-based mosquito control. However, insecticide resistance arises massively in vector mosquitoes, causing control failure and resurgence of malaria. Previous studies highlighted that these resistance mechanisms are very complex since they induce unexpected compensation mechanism that strengthen mutation-altered physiological functions. Compensatory mechanisms obviously impact the effectivness of Insect Resistance Managment (IRM) and insecticide-based strategies. As silent point mutations are the most common resistance phenomenon, we investigated the compensatory neuronal mechanisms following the development of resistance-associated point mutations in two strains of Anopheles gambiae resistant to two distinct class of insecticides : 1) Acerkis strain, resistant to organophosphates and carbamates (Ace-1R, G119S substitution in acetylcholinesterase 1) and 2) KdrKis strain, resistant to pyrethroids (kdr, L1014F substitution in voltage-gated sodium-channels). We use RT-qPCR, electrophysiological and calcium imaging approaches adapted to isolated Anopheles gambiae neurons to characterize changes in the expression and pharmacological profile of neuronal nicotinic acetylcholine receptors (nAChR) following the mutations G119S in AcerKis strain and L1014F in KdrKis strain compared to the laboratory reference Anopheles gambiae Kis strain. We report that 1) higher nAChR density associated with reduced AChE1 activity is observed in AcerKis strain, and 2) modification of biophysical properties of the voltage-gated sodium current impacts nAChR sensitivity to acetylcholine, the most abundant endogenous excitatory neurotransmitter. These physiological modifications act as compensatory mechanism in the cholinergic system upon resistance-associated mutation appearance. They need to be taken into account to adapt vector control strategies.
70
A Specific Rhizomicrobiome Selected by a Long-lived Endemic Plant in the Sub-Antarctic Kerguelen Islands
L. J. Marchand1*, F. Hennion1, M. Tarayre1, M.-C. Martin1, B. R. Martins12 and C. Monard1 * = presenting PhD student
1 University of Rennes, CNRS, ECOBIO (Ecosystèmes, Biodiversité, Evolution) UMR 6553, Rennes, France
2 Helmholtz Zentrum München, Research Unit Comparative Microbiome Analysis, Neuherberg, Germany Keywords: rhizomicrobiome, plant vigour, ecology
Abstract: The rhizomicrobiome selected by plants among the bulk soil microorganisms harbours valuable functions for plants. For perennial species, we expect this selection to be strong due to plant development over time. This association between plants and their rhizomicrobiome might be even more valuable in harsh environments (e.g. cold and windy conditions) such as in the sub- Antarctic Kerguelen Islands. These islands harbour a unique biodiversity, in particular a strict endemic, long-lived cushion plant Lyallia kerguelensis which lives at least 20 years. Recently, necrotic parts were observed on cushions of this species which might be related to water stress that increased during the last decade in these islands subject to rapid climate change. We hypothesized that the rhizomicrobiome of L. kerguelensis could be involved in plants’ vigour facing necrosis. The objectives of this study were (i) to describe the microbial communities in soils from different sites in the Kerguelen Islands and determine the corresponding rhizomicrobiome selected by L. kerguelensis and (ii) to determine if the relative abundance of some microorganisms was correlated to necrosis extent. Bulk soil and the rhizosphere of ten L. kerguelensis plants were sampled in five sites across the islands to analyse bacterial and fungal diversities using a metabarcoding approach. Both soil physicochemical properties and the necrosis extent of each sampled plant were determined. Microbial communities in both the bulk soils and the rhizosphere of L. kerguelensis were site- specific and bacterial and fungal assemblages were not driven by the same soil properties. For most plants, microbial richness in the rhizosphere was similar to the one observed in the corresponding bulk soil. Forty three microbial OTUs were correlated to necrosis extent, suggesting an involvement in plant vigour. These microorganisms were related to N2 fixation or saprophytic functions, which might help the plant to respond to stresses. In the context of climate change, the rhizomicrobiome should play a key role for L. kerguelensis to cope with increased stresses and enhance the response potential of this long-lived and endemic species. 71
Sedimentary breccias: a marker of lithospheric extension?
Tarik Kernifa*, Thierry Nalpasa, Pierre Gautiera, Sylvie Bourquina, Marc Poujola *[email protected] a Univ Rennes, CNRS, Géosciences Rennes, UMR 6118, 35000 Rennes, France. Keywords: Geosciences, sedimentary breccias, extension
Abstract: A breccia is a rock made up of angular clasts, produced through a large variety of processes: they can have a sedimentary, tectonic, karstic, hydrothermal, magmatic or impact origin. As a result, breccias may be found in a wide range of geodynamic environments. However, in the same way that the presence of flyschs and molasses is commonly viewed as having a specific geodynamic significance during the evolution of foreland basins, the idea grounding this study is that the formation and preservation of sedimentary breccias may also be typical of specific tectonic conditions. If this is true, what type of information could be gathered from the preserved bodies of sedimentary breccias in order to constrain the tectonic evolution of a given region? In this study, we are interested in the formation and preservation processes of sedimentary carbonate breccias that occur as large masses. In sedimentary carbonate breccias, limestone or dolomitic clasts are very angular to sub-angular, with sizes ranging from granules to huge blocks. The binding phase (or interclastic space) can be either a matrix (micrite), granular (calcisiltite, calcarenite or µ-clasts), or/and chemical precipitate (cement). Two examples of large masses of sedimentary breccias were studied: Late Jurassic deposits of the Bas Agly syncline, in the northeastern Pyrenees (France), and Pleistocene deposits along the southern coast of Crete (Greece). The results of our sedimentological study have allowed us to understand how the various breccias facies observed were formed over time as well as their spatial and temporal distribution. Based on the vertical and horizontal relationship between the different breccia facies, we were able to describe the processes of the deposit and to construct a geological deposition model. This study shows that the sedimentary breccias formed during extensional tectonics are spatially associated with large-throw normal faults. According to our observations, active normal faults with large throws provide the conditions for the formation and preservation of large volumes of sedimentary breccias through the following processes: i) footwall uplift, creating a pronounced topography with steep slopes, giving rise to major rockfalls, ii) hanging wall rapid subsidence, which allows for the accumulation and preservation of the breccias without the clasts being reworked by the drainage systems. Therefore, sedimentary breccias are readily formed as thick syn-tectonic deposits during the early stages of extensional basin development. Thus, they may be considered as a marker of lithospheric extension.
72 The drivers of vine-plant root microbiota endosphere composition include both abiotic and plant-specific factors
Biget Marinea*, Mony Cendrinea, Jambon Oliviera , Chable Véroniqueb, Pernet Sabrinac, Vandenkoornhuyse Philippea
(* = presenting PhD student, subsequent authors optional) a* UMR CNRS 6553 ECOBIO, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France b INRA UMR BAGAP INRAE Centre Bretagne-Normandie c Château Palmer, lieu dit Issan, Margaux
Keywords: Ecology, root microbiota, local factors
Abstract: Microorganisms associated with plants are determinant for their fitness, but also in the case of vine grapes, for the quality and quantity of the wine. Plant microbiota is however highly variable in space despite a deterministic recruitment from the soil reservoir. Therefore, understanding the drivers that shape this microbiota is a key issue. Most studies which have analysed microorganisms associated with vines have been conducted at large scales (e.g. over 100 km) and have analysed the bulk soil and the rhizosphere. In this study, we focused on the root-microbiota endosphere, the most intimate fraction of microorganisms associated with plants. We sampled vine roots in 37 fields distributed throughout a vineyard to investigate drivers shaping the grapevine microbiota at the α- (i.e. within-field) and γ- (i.e. between-field) diversity scales . We demonstrated that vine endospheric microbiota differed according to both the edaphic and plant-specific parameters including cultivars and age. This work supports the idea of an existing microbial terroir occurring within a domain and offers a new perspective for winemakers to include the microbial terroir in their management practices.
73
Origin of the gypsum veins associated with the early Cretaceous Bouhedma formation, Northern Chotts range, Southern Tunisia Nabil ABAAB 1,2,3*, Alain ZANELLA 1, Dhaou AKROUT 2,3,4, Régis MOURGUES 1, Mabrouk MONTACER2 1 Le Mans Université, Géosciences Le Mans - LPG UMR 6112, 72085, Le Mans, France 2 U.R: 3G – Géosystèmes, Géo-ressources et Géo-environnements, UR13ES80, Faculté des Sciences de Gabès, Tunisie. 3 Institut Supérieur des Sciences et Techniques des Eaux de Gabès, Université de Gabès, Gabès, Tunisie. 4 École Supérieure polytechniques, 4303 Cité Cadres, Sebkha Nouakchott, Mauritanie.
Keywords: fluid-assisted fracturing, gypsum vein, geosciences Abstract: Bedding-parallel fibrous gypsum veins, “BPV”, which occur in evaporite basins worldwide, provide significant in-sights into host rock deformation and fluid flow, although the genetic mechanism remains obscure. BPVs in the evaporite and mudstones of the upper Hauterivian - Barremian Bouhedma Fm of the Northern Chotts range were characterized in the context of regional and local setting. In order to investigate the origin as well as the timing of formation of “BPV” of the Bouhedma Fm, we performed a field work analysis. In our study our first describe the petrology of BPV, then the morphological criteria and their distribution in the sedimentary sequence. Finally, we pay attention to their relationship with tectonic structures as folds and faults. BPV exclusively appear in the Bouhedma Fm, which is time of vast evaporite production and a high rate of sedimentation in relation to a syn-sedimentary fault affecting the Zemlet El Beidha Anticline Structure “ZBAS”. The host rocks for BPV are mostly mudstones and evaporites, or less commonly carbonates. BPV contain typical fibrous crystals of gypsum and anhydrite. At the center of the veins, the median zone is often composed by fragments of mudstones. BPV are not randomly distributed through the sedimentary succession. Thus, they mainly occur at mudstones/gypsum boundaries as well as within gypsum beds. At boundaries, BPV are thick and very continuous (up to 40 cm thick). However, in evaporitic layers dense anastomosing networks of BPV occur but the they are very discontinuous (no more than 1 m in length) and thin (up to 6 cm thick). Within the mudstones BPV are also present and exhibit often more than 5 cm of thickness. Regarding the time of generation, BPV are affected by the Miocene compressional deformation (folding) event as well as by the Villafranchian contraction. As consequence, oblique filled fractures cross-cut and thus post-date, the BPV of the Bouhedma Fm with a direction of N135-N185. Our observations demonstrate that BPV in the Bouhedma Fm have been developed from Miocene to the post-Villafranchian times with a minimum of 3 stages of formations. We infer that BPV are the result of fluid overpressures in low-permeable mudstones and evaporites. Because the fractures initiated in response to fluid overpressures, they provide a useful analog to subsurface fluid-assisted fracture systems in low-permeability rocks subjected to tectonic compression.
74 Omics metrics for ecological niche potential and metabolic interactions
Hacquard S., Max Planck Institute for Plant Breeding Research (Germany), Group Leader Mataigne V., UMR ECOBIO, Université de Rennes I (France), PhD student Vandenkoornhuyse P. UMR ECOBIO, Université de Rennes I (France), Professor Vannier N., Max Planck Institute for Plant Breeding Research (Germany), PhD
Abstract: Metabolic interactions among microbes are frequently investigated to explain microbiome dynamics and structure. We explored bacterial genomes with phylogenetic and metabolic metrics, in an attempt to investigate niche potential and find patterns for putative metabolic dependencies. In this aim, genomes of a culture collection of 193 bacteria of the Arabidopsis thaliana root microbiome were used. We found that the absence or presence of chemical reactions within genomes is clustered by phylogeny, highlighting metabolism specialization and differentiation respectively within and between taxonomic groups. We also modeled all strains’ production ability of relevant compounds (amino acids, vitamins, phytohormones) in a non-constrained rich medium and a constrained minimum medium mimicking a rhizosphere environment. Many strains could produce most targeted compounds on the non-constrained medium, and lost this ability on the constrained-one medium, suggesting dependencies on the secretome of producer strains (i.e. cross-feeding). Moreover, the differentiation of metabolism according to taxonomy weakens when considering only the capacity of producing the targeted compounds. This suggests the importance of available nutrients in the media for niche -potential, -realization, - differentiation, and -overlap. We can also hypothesize that the chosen targets are too ubiquitous to distinguish the strains, i.e. part of their core metabolism, and that niche differentiation appeared to be linked to secondary metabolism. From the 193 strains collection, several metrics applied on random bacterial communities indicated that the number of different reactions in the genomes notably increases with average phylogenetic distance, with an optimum reach for small-sized communities (community and genomes sizes also have an influence). The shared reactions (core metabolism) decreases along the same metrics, without optimum. The biological meaning of these findings is still unclear, but the observed optimum could be interpreted as a niche overlap optimum, a trade-off between metabolic dependencies and competition. Despite these patterns, the relevance of these metrics obtained by microbial system ecology has to be demonstrated. Experimental validation of some synthetic communities are currently being carried out. In any case, it opens new routes of research to understand co-existence and functional interdependence in the root microbiome.
75 Oral Presentation 3 (O3) – 1st July
Session 1 (O3S1) 76
The impact of housing conditions on porcine adult stem cell populations differ between adipose tissue and skeletal muscle
Audrey Quéméner*, Frédéric Dessauge, Marie-Hélène Perruchot, Nathalie Le Floc’h, Isabelle Louveau PEGASE, INRAE, Institut Agro, Saint Gilles, France
Keywords: Alimentation, pig, adult stem cells
Abstract: Background. In pigs, the ratio between lean mass and fat mass determines production efficiency and is strongly influenced by the number and size of cells in tissues. During growth, the increase in the number of cells results from the recruitment of different populations of multipotent adult stem cells residing in the tissues. We hypothesized that the impact of a hygiene challenge on the proportions of adult stem cells in adipose tissue and skeletal muscle may differ between pigs with different residual feed intake (RFI), a measure of feed efficiency. Methods. At the age of 11 weeks, Large White pigs from two lines divergently selected for low and high RFI were housed in two contrasting hygiene conditions (good vs poor). After six weeks of challenge, pigs were slaughtered (n = 5-9/group). Samples of subcutaneous adipose tissue and longissimus muscle were collected, and cells from the stromal vascular fraction (FSV), which includes adult stem cell populations, were isolated from each tissue. Adipose and muscle cell populations from the FSV were phenotyped by flow cytometry using antibodies that targeted different cell surface markers (CD45 to identify hematopoietic cells; CD34, CD38, CD56 and CD140a to identify mesenchymal stem cells (MSC) with adipogenic and/or myogenic potential). Results. Adipose tissue and muscle shared some common MSC populations although MSC diversity was higher in muscle than in adipose tissue. In muscle, the CD45-CD56+CD34- CD140a+ and CD45-CD56+CD34+CD140a+ cell populations were abundant. Of these two cell populations, only the proportions of CD45-CD56+CD34+CD140a+ cells increased (P < 0.05) in pigs housed in poor hygiene compared with good hygiene conditions. For the CD45-CD56- CD34- cell population, present in low proportion, there was an interaction between hygiene condition and genetic line (P < 0.05) with a decrease in low RFI pigs housed in poor hygiene conditions. In adipose tissue, the two abundant MSC populations were CD45-CD56-CD34- and CD45-CD56+CD34-. Moreover, the proportion of CD45-CD56-CD34- cells increased (P < 0.05) whereas the proportion of CD45-CD56+CD34- tended to decrease (P < 0.1) in pigs housed in poor conditions. This study shows that the proportions of some MSC populations were affected by hygiene of housing conditions in a tissue-dependent manner in pigs of both RFI lines. Therefore, these cell populations could be targeted to modulate growth and body composition in growing animals.
77
Understanding the resistance mechanisms of the white mustard (Sinapis alba) to the pollen beetle (Brassicogethes aeneus)
Laura BELLECab*, Sébastien FAUREa, Maxime HERVÉb, Anne Marie CORTESEROb a Innolea, 6 Chemin de Panedautes, 31700 Mondonville, France b IGEPP, INRAE, Institut Agro, Univ Rennes, 35000, Rennes, France
Keywords: Ecology, Plant-insect interactions, chemical ecology, quantitative genetic
Abstract: The decision of a phytophagous insect to feed or not on a plant depends both on its physiological state and on plant’s traits. These traits can be either phagostimulants such as sugars or phagodeterrents such as physical barriers or defense compounds. Plants have evolved resistance mechanisms based on these phagodetererent traits, which limit injuries caused by herbivores. The identification of plant traits causing resistance as well as their genetic determinism would be of great interest, particularly to control insect pests that cause up to 16 % annual yield loss worldwide. These pests are classically controlled with synthetic insecticides, which negative impacts on health and biodiversity and limited efficacy is well documented. Alternative control methods are needed, among which resistance-based genetic control that aims at selecting plants showing traits limiting insects’ feeding.
In this PhD we work on developing such a method to protect oilseed rape (Brassica napus) against one of its major pests, the pollen beetle (Brassicogethes aeneus). Before blossoming, pollen beetles destroy flower buds to feed on the pollen they contain, which can cause serious yield losses. The only current control method of pollen beetles is the spraying of insecticides. However, resistance to insecticides has gradually become widespread and alternative strategies are urgently needed. So far, no resistance has been found in oilseed rape that could be introduced into elite varieties. However, the white mustard (Sinapis alba), a relative brassicaceous species, has been shown to possess partial and variable levels of resistance. The first objective of this PhD is then to better understand pollen beetle’s nutritional ecology to identify key traits responsible for white mustard’s resistance. A second objective is to understand the genetic determinism of these traits. Previous studies have shown that the resistance of the white mustard is expressed once the pollen beetle comes into contact with flower buds. A bio-guided fractionation approach of buds’ surface and internal compounds is being performed using feeding tests on artificial substrates. The composition of the fraction responsible for resistance will then be identified by metabolomics. In parallel, quantitative genetic approaches using segregated populations derived from crosses between contrasted genotypes is being conducted to identify regions of the white mustard’s genome correlating with pollen beetle resistance.
78
Carbon and dry matter losses during composting of date palm residues with rock phosphate and sheep manure as additives
Mustapha El Janati (1,2,3) *, Paul Robin (2), Nouraya Akkal-Corfini (2), Ahmed Bouaziz (1), Ahmed Sabri (4), Zahra Thomas (2) and Abdallah Oukarroum (3)
1 Institut Agronomique et Vétérinaire Hassan II, Rabat, Morocco 2 Agrocampus-ouest, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnemen/UMR SAS, Rennes, France 3 Polytechnic Mohammed VI University, Benguerir, Morocco 4 Institut National de Recherche Agronomique/Errachidia, Morocco
Corresponding author, email: [email protected]
Keywords: composting, agronomy, date palm residues Abstract
The Oasis region faces low soil fertility and harsh environmental conditions. Date palm is the main crop in oasis agroecosystem, which produces large quantity of Date Palm Residues DPR. They could be converted to organic fertilizer throughout the process of composting to return back into the soil. The study aimed to assess the combined effect of phosphate rock RP and sheep manure SM addition on DPR composting process and final compost quality. DPR were shredded and composted alone (T1) and in mixture with sheep manure SM (T3) (70:30 % volume basis). Rock Phosphate RP was added to DPR (T2) and to the mixture of DPR and SM (T4). The four mixtures were composted in windrows system; and monitored in triplicate during 123 days including two turnings. During the composting process, chemical and physical [moisture, mass, volume, free air space] mixtures properties were examined at each turning. Windrow temperature was monitored daily. The temperature increased up to 55 °C for mixtures T1 and T2, and to 70 °C for mixtures T3 and T4, and then decreased to ambient levels by the end of the composting period for all mixtures. Losses of dry matter were higher in T1 and T2 (35 and 39% respectively) than in T3 and T4 (25 and 27% respectively). The addition of RP slightly increased the biological activity of the compost windrow, leading to increased temperature and mass loss. Organic matter decrease was significantly higher in T3 and T4 than T1 and T2. The results suggest that phosphorus availability can be a limiting factor of DPR composting. SM addition accelerated the drying process showing that careful attention should be given to free air space in dry climate, in order to avoid the limitation of biological activity due to suboptimal water availability.
79
Simplified spectrophotometric acid-base titrations to assess organic matter reactivity
a a a b Marawit Tesfa* , Rémi Marsac , Aline Dia , Fabrice Mahé a CNRS - UMR 6118 Géosciences Rennes, 35042 Rennes cedex, France b Université de Rennes, CNRS, IRMAR - UMR 6625, F-35000 Rennes, France
Keywords: Spectrophotometry, Reactivity, Geosciences Abstract: In environmental issues, including soil quality and contamination studies, Natural Organic Matter (NOM) holds a crucial role because of its size, ubiquity and high reactivity. NOM’s adsorption onto mineral surfaces and reactivity towards various contaminants and trace elements are mainly related to their acid-base groups such as, carboxylic and phenolic ones. To study these groups, different characterization and quantification methods have been developed. Acid-base potentiometric titration is the most reliable one but, is time-consuming and often impossible to apply to environmentally relevant NOM concentrations. Recent studies showed the great potential of spectrophotometric titrations in NOM analysis. UV-vis spectra of a NOM solution are recorded for different values of pH. The relative absorbance (ΔA(λ,pH)) with respect to a reference pH (e.g. pH 3) was shown to evolve according to: ΔA(λ,pH) = A1(λ)×f1(pH) + A2(λ)×f2(pH) eq.1
Where A1(λ) and A2(λ) are specific absorbance of carboxylic and phenolic groups, respectively, + + f1([H ]) and f2([H ]) are functions of pH. However, the proposed methods face some limitations. Firstly, data acquisition is time-consuming (~ 4h) and can hardly be automated. Secondly, the analysis of ΔA(λ,pH) instead of the absorbance A(λ,pH), leads to larger analytical errors and a loss of spectroscopic information. Thirdly, eq.1 is generally applied for a single wavelength, overlooking information in the rest of the spectra. Finally, absorbance data do not allow direct quantification of carboxylic and phenolic groups concentration, which requires potentiometric titration. In this study, a method based on the use of pH buffer in acid-base titration speeded up to 4 times the sample preparation, and gave similar results to the published method. Equation 1 was modified to elaborate a MATLAB script allowing the use of A(λ,pH) and the estimation of functional groups’ proportion, behavior and specific UV-vis spectrum. By analyzing NOM reactivity for seven IHSS standard samples, empirical equations are proposed for a direct estimation of carboxylic and phenolic groups concentrations. The present development will help measuring NOM reactivity, hence providing constraints for the modeling of contaminants’ fate in the environment.
80
Inability of natural mutant population of aphids to switch their reproductive mode is probably due to alteration of genetics programs required for sexual embryogenesis
Mélanie Denise Hugueta*, Julie Jaquiérya, Stéphanie Robina, Sylvie Tanguya, Sylvie Hudaverdiana, Nathalie Prunier-Letermea, Romuald Cloteaua, Patricia Legoix-Néb, Sylvain Baulandeb, Jean- Christophe Simona, Denis Tagua, Gaël Le Trionnairea.
a UMR IGEPP, INRAE - Institut Agro - Université de Rennes a, Domaine de la Motte, 35600 LE RHEU, France b NGS Platform, Institut Curie, 75005 Paris, France
Keywords: Ecology, reproductive polyphenism, RNA-seq
Abstract: Aphids are important crop pests that feed on phloem sap and can affect the physiology of the plant. They are also particularly well adapted to the fluctuations in their environment due to their remarkable ability to display phenotypic plasticity. The most striking example is the reproductive polyphenism they can display during their life cycle. Indeed, in response to the autumnal photoperiod shortening signal, they are able to switch from parthenogenetic reproduction (viviparous females) that causes most of the damages during spring and summer to sexual reproduction ended up with the production of sexual morphs (oviparous females and males) that mate to lay overwintering diapausing eggs. Lineages that are able to perform this switch are called as CP (Cyclical Parthenogenesis). In nature, some lineages lost this ability and are referred as to OP (Obligate Parthenogenesis). Population genomic studies revealed that a region under divergent selection located on the X chromosome discriminates CP and OP lineages (Jaquiéry et al., 2014). Mutations on the sequence of genes located in this region are likely to explain the inability of the OP lineages to form oviparous females. It is hypothesized that these causal mutations could affect either the perception and neuroendocrine transduction of the photoperiod signal (which occurs in the head) or the ability of embryonic germ lines to change their reproductive fate. To characterize the consequences of these mutations on the ability of lineages to produce oviparous females, heads and embryos transcriptomes in the CP and OP lineages placed under different photoperiod conditions were analyzed using RNA- seq. Interestingly, it was shown that the perception and transduction of the photoperiod signal do not seem to be altered in the OP lineage. On the other hand, the analyses showed that the causal mutations seem to prevent embryos of OP lineages to switch to oviparous production program.
81
The importance of tertiary roots in young peas for future service legume selection
Laure Boeglina,b*, Anis M. Limamib, Joëlle Fusteca a USC LEVA, Ecole Supérieure d’Agricultures, INRAE, 49007, Angers Cedex, France b Univ Angers, Institut Agro, INRAE, IRHS, 49000 Angers, France
Keywords: Agronomy, pea roots, nitrate- symbiosis signal
Abstract: Combining a legume as a service plant with a cash crop may present a double agroecological advantage: the legume may help in weed control by competing with them for light and soil elements such as nitrogen [1], while improving nitrogen use efficiency of the cropping system thanks to symbiotic nitrogen fixation [2]. Among other legume species, pea has been shown as one of the relevant species to control weeds when intercropped with rapeseed, based on its aboveground traits [1]. However, legumes are known to be poorly competitive for mineral nitrogen uptake at crop establishment [3]. A mean to increase the value and productivity of new agroecological practices such as intercropping in a context of herbicides and chemical nitrogen fertilizers limitation, is to identify relevant levers to improve weed control using intercropping with legumes such as pea. In legumes, the ability to absorb nitrate may be linked to lateral root development (LR) [4]. In this context, highly branched and fast-growing root systems would be traits of interest for a service legume [4]. The formation of LRs is itself induced by the nitrate signal, but may compete with nodule formation, which also depends on soil mineral nitrogen concentration [5]. In order to explore the trade-offs between the formation of LRs and the formation of nodules, we have phenotyped the root system architecture of 3-week-old pea plants (Pisum sativum L. 'Frisson') cultivated in greenhouse conditions under various nitrate concentrations in presence or absence of Rhizobium leguminosarum. As desired, contrasted root architectures were obtained through the different nitrate concentrations, impacting the nodules number (p<10-13), biomass ratio (p<0.01), Specific Leaf Area index (p<0.001) and root diameter (p<0.001). Among these differentiated root systems, our results highlight the Rhizobium effect on the length of primary root (p<0.03), the length of secondary roots (p<0.001), and particularly on tertiary roots. Our study demonstrated that tertiary roots of the pea are more sensitive to the presence of the bacterium compared to the primary and secondary roots through several variables: roots number (60 tertiary roots per plant on average against 90 in the presence of Rhizobium, p<0.01); which is reflected in the indexes results linked to root branching (branching ratio p<0.01); but also on the root density: root branching architecture (p<0.03) and root branching intensity (p<10-5). In conclusion, tertiary roots development must be henceforth considered as a key factor and a promising selection requirement, for an improved efficiency in weed control by a relevant service plant more suitable for the productivity of new systems, and the effectiveness of new practices such as associations crops.
[1] Lorin et al. 2015. European Journal of Agronomy, 71:96–105 ; [2] Fustec et al. 2010. Agronomy for Sustainable Development, 30(1) ; [3] Hauggaard-Nielsen et al. 2009. Field Crops Research, 70:101–109 ; [4] Dayoub et al. 2017. Heliyon, 3(2) ; [5] Herrbach et al. 2014. Journal of Plant Physiology, 171:301– 310
82
Recurring Campylobacter jejuni lineages causing human infection in Luxembourg and revealed by Whole Genome Sequencing
Morgane Nenniga-b*, Ann-Katrin Llarenac, Malte Heroldd, Joël Mossonge, Christian Pennyd, Serge Loschf, Odile Tresseb and Catherine Ragimbeaua a* Epidemiology and Microbial Genomics, Microbiology Department, Laboratoire National de Santé, Dudelange, Luxembourg b* UR 1194 INRAE, Microbiologie et Chaine alimentaire, Jouy-en-Josas, France c Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway d Luxembourg Institute of Science and Technology, Environmental Research and Innovation Department, Belvaux, Luxembourg e Health Directorate, Ministry of Health, Luxembourg, Luxembourg f Laboratoire de Médecine Vétérinaire de l’Etat, Veterinary Services Administration, Dudelange, Luxembourg
Keywords: alimentation, zoonosis, molecular surveillance
Abstract: Campylobacter spp. is the leading cause of bacterial foodborne diarrheal disease worldwide with C. jejuni species involved in more than 80% of human cases. Poultry is considered as the main reservoir of this zoonosis and the transmission is commonly associated with (cross)-contamination during handling raw meat, consumption of undercooked meat or raw drinking milk. Outbreaks caused by Campylobacter spp. are increasingly being identified and reported on a regular basis. The generally high incidence recorded in Luxembourg over the last decade has motivated the establishment of molecular surveillance from the routine collection of isolates from various sources (human, food, farm animals and environmental waters). The initial comparison of genetic profiles by an in-house typing method suggested an unexpected endemic pattern in the temporal distribution of human genotypes (genetic profiles). The aim of this study was to investigate if these strains were clonal by applying the higher resolution typing method at the genome level, namely the Whole Genome Sequencing (WGS) using the gene-by-gene approach. This pilot study assessed four currently WGS-based typing schemes to classify a panel of 108 strains previously identified as recurrent or sporadic. The strain collection included four common lineages in human infection (N = 49) and non-human samples: veterinary (N = 19), food (N = 19), and environmental (N = 2) sources. An additional set of 19 sporadic strains completed the tested panel. All the strains were processed by Next Generation Sequencing using Illumina technologies and by applying stringent quality criteria for filtering sequencing data. A great concordance between the four typing schemes, including different number of targets for comparing strains (637, 678, 1,343 and 2,795 target genes), was highlighted by calculating the adjusted Wallace coefficients. Our results indicated that, regardless of the typing scheme used, epidemic or endemic signals were detected. These findings support the clonal expansion of stable genomes in Campylobacter population exhibiting a multi-host profile and accounting for the majority of human clinical strains isolated over more than a decade in Luxembourg. Such recurring genotypes suggest persistence in reservoirs, sources or environment, inducing future investigations to understand better their survival strategy. 83
Oral Presentation 3 (O3) – 1st July
Session 2 (O3S2)
84 Microwave Coagulable Alveolar Foams
Manon Chemina,b, Olivier Paurda, Laure Villacèquea, Alain Riaublancb, Patricia Le Bailb a : NBread Process®. 17 rue des entrepreneurs, 41700 Le Controis en Sologne (France) b : INRAe, BIA/ISD. 3 impasse Yvette Cauchois, 44300 Nantes (France)
Keywords : Alimentation, Sponge cake, Microwave
Abstract :
Snacking is an increasingly coveted mode of consumption, but which often has a negative image in terms of diet. The process used in this work makes it possible to transform almost any type of food into a compact food, having the texture and appearance of sponge cake. Its principle is based on the emulsion and then expansion of a paste under the pressure of a gas, followed by coagulation in the microwave. This process has the advantage of being fast and inexpensive in energy compared to the traditional preparation method. The objective of this research is to understand the phenomena which govern the transformations of raw materials during the different stages of manufacture: formulation, cooking, cooling and storage, from a vegetable sponge recipe. The goal is to achieve a high level of knowledge on the texturing of the material, in order to optimize the process and develop a sponge cake enriched with micronutrients for athletes or the elderly.
85
Formation of subglacial triangular-shaped bedforms: indicators of hydrological changes during ice sheet retreats
Jean Vérité1*, Édouard Ravier1, Olivier Bourgeois2, Paul Bessin1, Stéphane Pochat2
1 LPG, UMR 6112, CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans CEDEX 9, France 2 LPG, UMR 6112, CNRS, Université de Nantes, 2 rue de la Houssinière, BP 92208, 44322 Nantes CEDEX 3, France
Keywords: Geosciences, Geomorphology, Glaciology Abstract: The knowledge of subglacial hydrological systems, reconstructed from the geomorphological records observable below palaeo-ice sheets, is critical to interpret basal thermal conditions, meltwater discharges and pressures and ice flow velocities. New high-resolution digital elevation models (DEMs) based on aerial LiDAR enable to better decipher the geomorphological records through higher accuracy mapping and identification of previously unrecognized glacial landforms. Recent work described hitherto unidentified triangular-shaped bedforms in Sweden and Finland (i.e. Scandinavian Ice Sheet, SIS), associated with meltwater corridors and ribbed bedforms tracts. Here we explore the subglacial environment in which the triangular-shaped bedforms develop and their genetic relationship with ribbed bedforms based on (i) an experimental model reproducing ice sheet dynamics and subglacial bedform formation and (ii) an analysis of the spatial distribution and the morphometry of triangular-shaped, ribbed and other intermediate bedforms within areas covered by the palaeo-SIS in Sweden and Finland. We find that triangular-shaped bedforms can develop subglacially from flooded ribbed bedforms during outburst floods, when the subglacial hydrological system undergoes periodic reorganizations between channelized and distributed drainage systems. The morphometric analysis of experimental and natural bedforms highlights a shape continuum ranging from high-elongation, low-circularity and low-sinuosity bedforms (i.e. ribbed bedforms) to low-elongation, high-circularity and high-sinuosity bedforms (i.e. triangular-shaped bedforms). We infer that triangular-shaped bedforms result from the remobilization of ribbed bedforms when the periodic overflows of a channelized drainage system induce repeated ice-bed coupling and decoupling phases. Erosion of ribbed bedforms and deposition processes occur during decoupling phases, whereas the stretching of ribbed bedforms in the downstream direction develop during coupling phases, progressively evolving into triangular-shaped bedforms. When ice sheets retreat during warm periods, meltwater corridors form by periodic subglacial outburst floods (i.e. high meltwater flows and high ice flow velocities) and are marked by triangular- shaped bedforms resulting from the dismantlement of ribbed bedforms fields, which formed during previous colder periods.
86
Statistical modelling of in vitro pepsinolysis using peptidomic data
Ousmane SUWAREHa*, David CAUSEURb, Françoise NAUa a STLO, INRAE, Institut Agro, 65 rue de Saint-Brieuc, 35042 Rennes, France b IRMAR UMR6625, CNRS, Institut Agro, 65 rue de Saint-Brieuc, 35042 Rennes, France
Keywords: Pepsinolysis; Cleavage specificity; Prediction model; Food sciences
Abstract:
Proteins digestion is a complex and dynamic process involving several proteases that particularly differ in their specificity. The specificity of pepsin, the major protease of gastric digestion, has been previously investigated, but only regarding the primary sequence of the protein substrates. The present study aimed to consider in addition physicochemical and structural characteristics, at the molecular and sub-molecular scales. For six different proteins submitted to in vitro gastric digestion, the peptide bonds cleaved were determined from the peptides released and identified by LC-MS/MS. An original statistical approach, based on propensity scores calculated for each amino acid residue on both sides of the peptide bonds, concluded that preferential cleavage occurred after Leu and Phe, and before Ile. Moreover, reliable statistical models developed for predicting peptide bond cleavage, highlighted the predominant role of the amino acid residues at the N-terminal side of the peptide bonds, up to the seventh position (P7 and P7’). The significant influence of hydrophobicity, charge and structural constraints around the peptide bonds was also evidenced.
87
Three is bigger than two and four: impact of the ploidy level on the recombination landscape in Brassica
Franz Boideau1*, Loeiz Maillet1, Virginie Huteau1, Gwenn Trotoux1, Maryse Taburel1, Frédérique Eber1, Marie Gilet1, Alain Bamme1, Anael Brunet1, Coleen Tanguy1, Jérôme Morice1, Julien Boutte1, Gautier Richard1, Cyril Falentin1, Olivier Coriton1, Mathieu Rousseau-Gueutin1 and Anne-Marie Chèvre1
1 IGEPP, INRAE, l’institut Agro, Université de Rennes 1, BP35327, 35653 Le Rheu Cedex, France * presenting author
Keywords: Agronomy, Polyploidy, Meiosis
Abstract:
Meiotic recombination via crossovers (COs) is a major mechanism generating new genetic diversity at each generation by reshuffling alleles inherited from the parents. Therefore, COs are highly regulated both in frequency and in distribution, with rarely more than three COs per chromosome that are almost exclusively present in subtelomeric regions. Recently, we observed that it was possible to modify this tight recombination control by creating an AAC allotriploid hybrid resulting from the cross of oilseed rape (Brassica napus, AACC, 2n=4x=38) with one of its diploid progenitors, turnip (Brassica rapa, AA, 2n=2x=20). However, it remains to be deciphered the impact of allotriploidy vs polyploidy per se (genome doubling) on this modified recombination landscape. To that purpose, we compared three Brassica F1 hybrids having different levels of ploidy: diploid (AA), allotriploid (AAC) and allotetraploid (AACC) with exactly the same A genotype. We then compared the homologous recombination landscape using a set of 202 SNPs well distributed along all A chromosomes. Our results indicate that the AAC hybrid present a 3.6-fold increase of COs all along the chromosomes compared to AA and AACC hybrids which have the same recombination profile on A genome. This highlights that allotriploidy and not polyploidy can deeply modify the recombination landscape in Brassica. This increase was cytogenetically confirmed in male meiocytes, using the immunostaining of the HEI10 protein involved in COs formation. To determine if recombination may occur in (peri)-centromere cold regions, we developed additional markers in such regions. Very interestingly, we observed that COs can arise at only 1 Mb from the centromere in the AAC allotriploid hybrid, whereas they occur (as expected) at 5 Mb from the centromere in the AACC allotetraploid hybrid. We are currently investigating if these modifications of the recombination rules in allotriploids can persist for several generations and revert when the plant recovers an AACC ploidy level, as well as the role played by epigenetic modifications in this unique phenomenon. Altogether, this study will provide new insights on meiotic recombination regulations in an interspecific hybrid and new ways to more efficiently enhance the narrow genetic diversity of a major polyploid crop.
88
In vitro incorporation of fat-soluble vitamins in mixed bile assemblies
A. El Aoud 1* E. Reboul 2 A. Dupont 3 C. Mériadec 4 F. Artzner 4 S. Marze 1
1 INRAE, BIA, F-44316 Nantes, France 2 AMU, INRAE, INSERM, C2VN, Marseille, France 3 CNRS, Biosit, UMS 3480, Université de Rennes 1, US_S 018, F-35000 Rennes, France 4 CNRS, Institut de Physique de Renne UMR 6251, Université de Rennes 1, F-35000 Rennes, France
Keywords. Lipid; fat-soluble vitamins; alimentation.
Abstract:
Background. The solubilization of fat-soluble vitamins (FSV) in supramolecular structures, usually called micelles or assemblies, is considered a critical step of intestinal digestion for high bioavailability. It was repeatedly shown that the presence in assemblies of lipid digestion products, monoglycerides (MG) and fatty acids (FA), enhances the solubilization of vitamins. The purpose of this study was to investigate the impact of the concentration and type of FA+MG on the structure of mixed bile assemblies and their solubilization capacity. Methods. DLS and turbidimetry were used to study the structural transitions due the incorporation of various digestion products or various FSV in mixed bile assemblies. Cryo- TEM and SAXS were used to resolve assembly structures at microscopic and supramolecular scales, respectively. Results. Upon FA+MG addition, a transition from ellipsoidal micelles to unilamellar vesicles (except for caprylate lipids, always yielding micelles) is observed. In these specific assemblies, increasing the concentration of a FSV either induced a systematic structural transition (vitamin E or K), or induced a structural transition only in micelles (vitamin A), or did not induce any structural transition (vitamin D). Conclusion. Our results showed that structural changes should always be considered to correctly determine the solubilization capacity in a specific assembly.
89 Quantification and modeling of the climatic services provided by trees in a canyon street S. Mballoa, S. Herpina,b, P-E. Bourneta and S. Demotes-Mainardc aEPHOR, INSTITUT AGRO, 49045 Angers, France bIRSTV, FR CNRS 2488, 44321 Nantes Cedex 3, France cINRAe, Unité Mixte de Recherche 1345, 49070 Beaucouzé, France
Keywords: microclimate, vegetation, ecology
Abstract: Growing urbanization makes the city an increasingly vulnerable area to heat. In addition to the anthropogenic cause and to the urban form that influences the wind speed and the absorption and reflection phenomena of incident solar radiation, the reduction in the proportion of vegetation is one of the main causes of urban overheating. Among the consequences of urbanization on the urban microclimate, the most known is the Urban Heat Island (UHI) phenomenon, which is a kind of heat accumulation phenomenon within urban area due to urban construction and human activities (Yang et al., 2016). UHI is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization (Rizwan et al., 2008). Extensive studies of the characteristics of UHI effect carried out in recent decades by authors such as (Arnfield, 2003; Rizwan et al., 2008) have shown that the UHI effect is closely related to urban heat release, surface properties and structure, vegetation coverage, population density and weather conditions (Yang et al., 2016). Vegetation plays an increasingly important role in urban planning policies because it helps reduce temperature peaks in cities during heat waves. Studies such as those of (Aboelata, 2020; Andreou, 2014) have been carried out on urban canyons, and others on urban areas as those of (Gebert et al., 2019; Gillner et al., 2015) to study the impact of vegetation. Many studies on the impact of vegetation on the urban microclimate have been undertaken in recent decades, but few have been carried out on tree- covered canyon streets. Canyon streets are representative places of the urban environment. The objective of my thesis is to quantify and analyze the climatic services provided by trees in urban areas and to study the impact of environmental conditions and water restrictions on these services. We carry out measurement campaigns on a canyon street on a scale of 1/5th and we also conduct numerical simulations using the ANSYS FLUENT software. A study to transpose the results into real scale will also be undertaken.
90
Soil aggregate stability dynamics of an agricultural silt soil following application of different digestates
Joshua Cookea*, Safya Menasseri-Aubreyb, Romain Giraulta, Anne Tremiera (* = presenting PhD student) a INRAE UR1466 OPAALE Optimisation des procédés en agriculture, agroalimentaire et environnement, 17 avenue de Cucillé CS 64427 35044 RENNES b INRAE UMR1069 SAS Sol Agro et hydrosystème Spatialisation, 65 rue de Saint-Brieuc 35042 Rennes
Keywords: Agronomy, Anaerobic Digestion, Soil Structure
Abstract: The digestate issue from anaerobic digestion is a nutrient rich organic material that may play an important role in the evolution of agriculture towards optimal resource management and improvement of soil health. However, their impact on soil physical properties is poorly understood, due to the complexity of the production processes involved, and the resulting variability in the properties of those digestates eventually used as fertilizer or soil amendment. The objective of this study was to understand what relationship, if any, exists between the physical and chemical properties of digestates and their eventual impact on soil physical properties – in particular soil aggregate stability. Soil aggregate stability is a rapid and sensitive measure of a soil’s ability to resist the forces of erosion and crusting, also linked to soil fertility, biological diversity, carbon storage, and water holding capacity. A panel of 17 digestates representing the diversity of those commonly used in agriculture across France were sampled from agricultural and territorial anaerobic digesters, and analyzed for their content in carbon and nitrogen forms, as well as trace elements. Organic matter composition was characterized using the “EPS” fractionation method1. Repeated long-term field application of these digestates was simulated through microcosm incubation trials under controlled laboratory conditions over a period of 3 – 6 months. Digestates were mixed at a dose of 6 gC/kg(dry soil) with aggregates of a silty agricultural soil from Brittany, France. Rates of carbon mineralization were monitored continuously over the length of the trial, while various soil properties were analyzed at fixed intervals through destructive sampling. Initial results suggest that, while digestates may have a less significant effect on soil structure for other organic amendments, an improvement in soil aggregate stability can still be observed at the application rates used. The result of digestate application varies significantly according to the type of digestate used. Cross-analysis of the characteristics of a digestate and its behavior in incubation, show that the type of substrates used, of anaerobic digester and post treatment, the mineral content, and organic carbon forms are all likely to play a role in determining the impact on aggregate stability. This research highlights promising pathways towards better observation and management of digestate impact in agriculture, as well as optimization of digestate properties to better suit use as a soil amendment.
1Jimenez, J., Gonidec, E., Cacho Rivero, J.A., Latrille, E., Vedrenne, F., Steyer, J.-P., 2014. Water Research 50, 359–372. https://doi.org/10/f5r7sr
91
Oral Presentation 3 (O3) – 1st July
Session 3 (O3S3)
92
High-resolution study of the Middle Eocene deposits of the Paris Basin
Nicolas Marie* (1), François Guillocheau (1), Justine Briais (2), Cécile Robin (1), Eric Lasseur (2).
(1) Univ Rennes, CNRS, Géosciences Rennes - UMR 6118, 35000 Rennes, France (2) BRGM, 3 avenue Claude Guillemin, 45060 Orléans CEDEX, France
Keywords: Paris Basin, Eocene, Geosciences Abstract: The Cenozoic of the Paris Basin is a period of low subsidence (200 m in 35 Ma maximum), associated with numerous sedimentary hiatus. The study of outcrops at high spatial and temporal resolution, as well as correlations by sequence stratigraphy and stacking pattern of more than 500 wells, have allowed the characterisation of the evolution of the geometry of the basin and its palaeogeography during the Middle Eocene, through the establishment of 7 sets of isopach maps and facies maps
(1) The fm. of the “Marnes et Caillasses” reputed to be characteristic of the Upper Lutetian and Lower Bartonian is in reality diachronous, passing laterally to lagoonal facies, then to protected marine facies. (2) The top of the “Marnes et Caillasses” fm. is incised by a network of multi-kilometre wide incised channels/valleys with a maximum depth of 30 m. The north-south and north-west- south-east network is presented here. The interfluves of these channels are altered. These paleo- incisions are filled in by the sediments of the Auvers Sand fm. This incision reflects an uplift of the whole basin during the Lower Bartonian and a drastic change of sedimentary system. (3) The first estuarine deposits of the Auvers Sand fm. are on onlap with the previous palaeotopography. The Bartonian is a remarkable example of a so-called low accommodation system, i.e. characterised by a low creation of available space, alternating periods of erosion, transit or non- deposition and brief periods with a high potential for sediment preservation, notably exceptional tidal facies. The extension of the different Bartonian sequences and their facies (marine, lacustrine, lagoon and eolian) is presented, in a well constrained stratigraphic context (notably the effect of volumetric partitioning). This study allows to reconstruct in 3D, at high spatial and temporal resolution, the geometry of the Middle Eocene deposits of the Paris Basin in order to predict the lateral and vertical variations of the petrophysical characteristics of the different facies studied
93
Three Oilseed rape soil microorganisms promote the establishment of parasitic plant Phelipanche ramose on host plant Brassica napus
Lisa Martineza*, Lucie Poulin a, Jean-Bernard Pouvreau a, Christophe Jestin b, Philippe Simier a, Philippe Delavaulta (* = presenting PhD student) a*Laboratoire de Biologie et de Pathologie Végétale EA1157, Université de Nantes, 2 Chemin de la Houssinière, 44322 Nantes b*Terres Inovia, 1, Avenue Lucien Bretignieres 78 850 Thiverval-Grignon Keywords: Branched broomrape, tripartite interactions, Ecology Abstract:
Parasitic plants are host-dependant angiosperms which connect to other plants for water and nutrient supply. Root parasites of the genera Orobanche and Phelipanche raise many concerns as they acquire all of their resources from a large range of economically important crops resulting in substantial yield losses. Yet, there are neither efficient nor sustainable control methods due to a complex interaction with biotic and abiotic environmental parameters which are difficult to control. Indeed, in the rhizosphere, the microbiome is likely to interfere with host-derived signal metabolites which are necessary for the parasitic plant recognition of its host - and modulates the parasite’s fitness. Our hypothesis is that native microorganisms in canola infested soil may increase parasitism in the occurrence of chemical signals. Coculture experiments were conducted in triplicates with Brassica napus as host plants and Phelipanche ramosa as parasitic plant seeds, on both native and gamma-sterilized oilseed rape originating soils. During these cocultures we monitored 1) plant parasitism through counts and development stages of P. ramosa root fixations 2) chemical signalization by analyzing the germinative power of root exudates on parasitic plant seeds and 3) bacterial community dynamics thanks to high throughput sequencing of 16S rRNA genes on bulk and rhizosphere soils. Complementary, to further comprehend the molecular dialog, we assessed the biological activities of soil. Five grams of native or sterilized soils were macerated in water and partly filtrated so that 0.22µm-filtrated extracts contained only soil metabolites whereas non-filtrated extracts contained both metabolites and living microorganisms. These soil extracts were then tested on germination and haustorium formation of parasite seeds. In the coculture experiment, P. ramosa fixation counts were higher in plants on native soils compared to sterilized soils in week 2 while there were no difference in week 5 and a slight enhancement in sterilized soils compared to native soils in week 7. Analyses of diversity indicated that native communities were stabilized in week 2 and that sterilization successfully disturbed the microbiome which displayed a later stabilization in week 5. Furthermore, co-occurrence network analysis indicated positive correlations between six modules of bacteria and germinative power of root exudates as well as broomrape attachment. This suggested that some bacterial taxa were able to promote parasitism during pre-attachment stages. Indeed, tests of non-filtrated soil extracts in the presence of glucosinolates revealed that microorganisms were directly involved in seed germination via the degradation of glucosinolates into isothiocyanates via microbial myrosinase enzymes. Additionally, they also exhibited an haustorial inducing formation (HIF) activity. On the other hand, filtrated extracts were ineffective in germination and were significantly less active for haustorium formation which showed that the microbial activity plays an important role in the crucial first step of the parasitic seed cycle. For the first time we concluded that microorganisms in the soil could improve the success of infestation during early stages via modulation of signal compounds.
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Development of new typing tools for Clostridium botulinum group III strains responsible for animal botulism outbreaks
LE GRATIET Thibault*a, ANNIBALLI Fabriziob, FELTEN Arnaudc, ROUXEL Sandraa, POEZEVARA Typhainea, HOUARD Emmanuellea, AVOUAC Amandinea, CHEMALY Mariannea, LE MARECHAL Carolinea aANSES, Laboratory of PLOUFRAGAN-PLOUZANE-NIORT, Unit of Hygiene and Quality of Poultry and Pork Products, FRANCE bNational Reference Centre for Botulism, Istituto Superiore di Sanità, 00161 Roma, ITALY cANSES, Laboratory of PLOUFRAGAN-PLOUZANE-NIORT, Unit Viral genetics and biosafety, FRANCE Key words: Clostridium botulinum group III, typing tools, MLVA Abstract: Botulism is a severe neuroparalytic disease affecting both humans and animals. This disease is caused by one of the most potent toxin called botulinum neurotoxin (BoNT), which is mainly produced by Clostridium botulinum, an anaerobic, spore-forming bacteria. Seven historical different BoNTs (A to G) have been reported, among which BoNTs type C, D and their mosaics C/D and D/C, produced by C. botulinum group III, are responsible for animal botulism. Outbreaks in animals can be associated with high mortality (up to 100% in a flock) and significant economic losses. Botulism outbreaks in wildlife can also have significant ecological impacts on wild bird populations. On a worldwide basis, botulism is one of the most important diseases of migratory birds. Despite this context, little is known about the epidemiology of animal botulism (like for example the identification of the source of contamination or monitoring of the contamination). The unavailibity of a method to isolate C. botulinum group III prevents the application of traditionnal molecular typing tools, widely used for strain tracking for other bacterial species. The objective of this project is the development of new molecular tools that could be used for typing of C. botulinum group III strains, usable under field conditions during animal botulism outbreaks. The first step was the development of a new reliable method for the isolation of C. botulinum group III strains. This method was succesfully tested on spiked samples and on naturally contaminated samples that were representative of avian botulism outbreaks detected in France in the last decade . Then, the objective of the project was to develop innovative tools suitable for epidemiological investigations during animal botulism outbreaks. A typing tool named Multi Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA), developped in Italy was transfered and evaluated on French strains isolated with the newly-developed method as well as in field conditions during outbreaks. The second strategy was the exploration of genomic data to identify relevant targets. A low number of genomes were available in public databases, more genomes were required for the project. One challenging step was to optimize an appropriate DNA extraction method to obtain high quality and quantity DNA for sequencing. Different targets are currently under investigation to provide an efficient tool usable to support investigations conducted during animal botulism outbreaks, what is crucially lacking for the management of the outbreaks at the moment.
95
Apple trees in garden-orchard systems improve soil quality and yield of organic radish crop
T. Ramananjatovo1,2*, R. Guénon1, G. Buck-Sorlin2, E. Chantoiseau1, P. Guillermin2, M. Delaire2 and P. Cannavo1
1*EPHOR, Institut Agro, SFR 4207 QuaSaV, 49045, Angers, France 2IRHS, INRAE, Institut Agro, Université d’Angers, SFR 4207 QuaSaV, 49071, Beaucouzé, France
Keywords: Soil organic matter, N mineralization, Agronomy Abstract: Maintaining healthy soil is a major challenge in agriculture. Associating annual crops with trees could be very interesting to ensure a high production and to conserve soil quality, as shown in agroforestry systems (Muchane et al., 2020). Trees improve soil fertility through the input of organic matter into the soil by litterfall and root turnover (Dupraz and Liagre, 2008) which enhance the soil microbial activities (Lagerlöf et al., 2014). This study aims at evaluating the effects of apple trees (Malus × domestica Borkh) on physical, chemical and biological soil qualities and their potential to improve the yield of an unfertilized organic radish crop (Raphanus sativus L., var. ‘Ostergruss’). To do so, from June to August 2020, we compared the soil properties and the yield of radish beds located either at 1.5 m (B1) and at 5 m (C) from a row of 20-year old apple trees. Litterfall, soil organic matter and soil bulk density were measured on each bed. To characterize the effects of apple trees on soil microbial activities biodegradation capacity, we assessed the decomposition rates of the previous crop residues (lettuce roots) on each bed using 5 mm-mesh litterbags buried at 15 cm depth. N mineralization rate was measured in-situ using PVC tubes described by Raison et al. (1987). Apple trees litterfall enriched the surface soil layer (0-30 cm) in organic matter (45 g.kg-1 soil DW on B1 vs. 35 g.kg-1 soil DW on C). Soil bulk density was significantly (p < 0.001) lower on B1 (1.2 g.cm-3) than on C (1.5 g.cm-3). Furthermore, the decomposition rate of lettuce roots was faster on B1 than on C: on B1, 50% of the initial dry mass was decomposed in two weeks and 65% after one month compared to only 35% and 48% on C bed, respectively. We also observed that net N mineralization rate was up to twice higher on B1 than on C. Consequently, soil NO3- contents in the 0-30 cm layer were significantly higher on B1 (p < 0.01). Radish yield was significantly higher on B1 (p < 0.001) due to higher soil mineral nitrogen content and lower soil bulk density. Our results suggest that tree-based intercropping is a promising option for ensuring both soil quality and productivity of organic root vegetable crops. References
Dupraz, C., Liagre, F., 2008. Agroforesterie: des arbres et des cultures. France Agricole Editions. Lagerlöf, J., Adolfsson, L., Börjesson, G., Ehlers, K., Vinyoles, G.P., Sundh, I., 2014. Land-use intensification and agroforestry in the Kenyan highland: Impacts on soil microbial community composition and functional capacity. Applied Soil Ecology 82, 93–99. Muchane, M.N., Sileshi, G.W., Gripenberg, S., Jonsson, M., Pumariño, L., Barrios, E., 2020. Agroforestry boosts soil health in the humid and sub-humid tropics: A meta-analysis. Agriculture, Ecosystems & Environment 295, 106899. Raison, R.J., Connell, M.J., Khanna, P.K., 1987. Methodology for studying fluxes of soil mineral-N in situ. Soil Biology and Biochemistry 19, 521–530.
96
Rheological properties of lactoferrin/β-lactoglobulin complex coacervates
Soussi, H.R.*, Famelart M.H., Rousseau F., Hamon, P., Bouhallab S.
INRAE, Institut Agro, STLO, F-35042 Rennes, France
Keywords: Alimentation, Complex coacervation, Rheology
Abstract: Complex coacervation is a liquid-liquid phase separation that leads to the formation of a highly concentrated phase or coacervates. The formed coacervates are proposed as carriers for bioactives because of their high encapsulation efficiency under mild processing conditions. Despite its multiple use, especially in the fields of food science, little has been reported on hetero‐ protein complex coacervation. In our previous work, we reported on the ability of two globular proteins, Lactoferrin (LF) and β-lactoglobulin (β-LG) to form coacervates under specific physicochemical conditions [1]. In the present work, we aimed to characterize the rheological properties of the formed LF/β-LG coacervates. We show that unlike some polysaccharide/protein systems, LF/β-LG coacervates has a liquid-like behavior; the loss modulus G” was 100 times higher than the storage modulus G’. This behavior was confirmed under creep-recovery tests. In addition, the coacervates exhibited a Newtonian viscous flow under low shear rate and a shear thinning behavior above 10 s-1. These results suggest a structural change probably due to the weaknesses of electrostatic interactions inside the coacervates at high shear rates. This structural change was proved to be reversible and the rearrangement of the structure was time-dependent. These results allow better understanding of the involved interactions in concentrated protein solutions and open new avenues for the use of coacervates as texturizing agents in food matrices.
References: [1]. Tavares, G. M., Croguennec, T., Hamon, P., Carvalho, A. F. & Bouhallab, S. Selective coacervation between lactoferrin and the two isoforms of β-lactoglobulin. (2015) Food Hydrocolloids 48, 238–247.
97
Individualization of flax tows promoted by physical pre-treatments: Impact on mechanical properties of a flax/PLA non-woven composite
Maxime Gautreaua(*), Antoine Kervoelenb, Fabienne Guillona, Alain Bourmaudb, Floran Pierrec, and Johnny Beaugranda a UR1268 Biopolymères Interactions Assemblages, INRAE, Nantes, France b Univ. Bretagne Sud, UMR CNRS 6027, IRDL, Lorient, France c Eco-technilin SAS, ZA Caux Multipôles, 76190 Valliquerville, France
Keywords: Flax tows - Physical pre-treatment - Ecology
Abstract: Technical fibers are composed of elementary fibers and fibers bundles. The cohesion between elementary fibers is ensured by a middle lamella. In natural fiber reinforced composites, an important parameter to have good mechanical properties is the individualization of the fibers. It has been shown that the middle lamella is an area of weakness in composites due to lower mechanical properties of this interfacial region. An aspect ratio (Length/Diameter) of the fibers greater than 10 is considered as the minimum value for good transmission of strength during mechanical stress loading. Pre-treatments on plant fibers are common to increase the individualization of the bundles. To induce this individualization of the fiber bundles, several types of pre-treatments exist. Chemical pre-treatments are very commonly used. For instance, alkaline pre- treatments of KOH or NaOH type are used to eliminate components of the fiber such as pectin and hemicelluloses. But the use of chemicals on natural fibers question about their eco-friendly aspect. That is why some physical pre-treatments are also used to increase the individualization of the fibers bundles. Microwaves partially degrade the polymers rich in water molecules mainly present in the middle lamella. In this work, two free of chemicals pre-treatments, ultrasound and gamma irradiation were applied to flax tows in order to increase the number of elementary fibers. First, the impact of the pre-treatments on the diameter of the tows was monitored using a dynamic morphological analyser. For each pre-treatment, a 20% increase in the number of elementary fibers was observed. Then, biochemical composition was investigated; exhibiting a partial elimination of sugars relating to pectin and hemicelluloses. The hygroscopic behaviour made by dynamic vapour sorption (DVS) showed a decrease of the sorption-desorption water hysteresis for both pre-treatments. Non-woven composites were produced from treated tows with a bio-based degradable matrix, poly-(lactid) (PLA). Moderate differences between the different composites was demonstrated; however, for the ultrasound pre-treatment, a significant increase of the stress at break was observed.
98
Functional characterization of BnD22 a Brassica napus PI- WSCPs “Protease Inhibitors-Water Soluble Chlorophyll binding Proteins” Youssef Bouargalnea*, Florian Guilbauda, Céline Raguénès-Nicolb, Vanessa Cloueta, Angélique Chéronc, Jean-François Hubertc, Carole Deleua and Françoise Le Cahéreca aUMR 1349 IGEPP « Institut de Génétique, Environnement et Protection des Plantes », INRAE – Institut Agro - Université de Rennes 1, 35653 Le Rheu Cedex, France bUMR_S 1085, Université de Rennes 1, Inserm, EHESP, IRSET (Institut de recherche en santé, environnement et travail) - Rennes, France cUMR 6290 IGDR « Institut de Génétique et Développement de Rennes » CNRS - Université de Rennes 1, 35043 Rennes Cedex, France *author speaker
Keywords: agronomy, chlorophyll binding affinity, proteolysis regulation Abstract: Water-soluble chlorophyll-binding proteins (WSCPs) are hydrophilic and non-photosynthetic apoproteins that interact with chlorophyll (Chl). Specific to Brassicaceae, they are induced by several abiotic stress. Their biological function remains unclear. WSCPs seems to function as Chl-scavenger after cell disruption and/or Chl-carrier during Chl biosynthesis but, until now, no chloroplast location is detected. These proteins belong to the Künitz protease inhibitor (PI) family and some PI-WSCPs show a PI function against Ser or Cyst proteases. The aim of this study is to characterize the biochemical functions of BnD22, a drought induced 22 kDa PI- WSCP protein of rapeseed (Brassica napus L.). This protein undergoes a post-translational modification by a 22 kDa C-terminal cleavage. The abundance of BnD22 in young leaves could contribute towards limiting protein and chlorophyll degradation in order to preserve metabolic activities. To gain insight into its biochemical function, recombinant BnD22-His tag proteins were produced in bacterial system in full and mature forms, BnD22F and BnD22M respectively. The impact of post-translational maturation on protease inhibitory activities and Chl-binding ability was followed in vitro. Firstly, the cleavage of C-terminal promotes drastically the production, solubility and stability of BnD22-His tag. Concerning WSCP function, we developed a new approach by thermophoresis to define precisely affinity binding between Chl and apoprotein. BnD22F-M bind preferentially Chl a compared to Chl b. As other WSCPS, the binding to Chl a or Chl b induce structural change with the formation of a tetrameric complex. Enzymatic assays identified BnD22F-M as effective inhibitor of Cys protease and no Ser protease. The post-translational maturation seems to have no effect on PI and WSCP properties. For the first time, we report that PI and WSCP properties coexist. Thus, tetrameric Chl-BnD22M complex still keep PI properties and BnD22M associated to protease is able to bind Chl and form oligomeric complex. This report on BnD22 may open new gate to understand the potent roles of PI-WSCPs in plant metabolism during stressful conditions.
99
Plasma Amino Acid and Metabolite Profiles of Adult and Growing Pigs after Feeding a Diet with Hydrolysed Feather Meal with a Balanced or Unbalanced Amino Acid Profile FA Eugenio1,2,*, J van Milgen1, J Duperray2, R Sergheraert2, N Le Floc’h1 1 PEGASE, INRAE, Institut Agro, 35590 Saint Gilles, France 2BCF Life Sciences, Boisel, 56140 Pleucadeuc, France *Presenting PhD student Keywords: amino acids, metabolism, alimentation Abstract:
High quality protein sources are important for both animals and humans and to limit their competition, animals can be fed with alternative protein sources that are not-intended for human consumption is needed. The acid hydrolysis of feathers (EHFM) produces a product with a very high protein digestibility but the amino acid (AA) profile is unbalanced for pigs. Although unbalanced dietary AA profile can negatively affect the overall metabolism of pigs, it can be corrected by supplementing the diet with synthetic AA. The objective of the experiment was to compare the postprandial plasma profiles of AA, glucose, free fatty acids, urea, lactate, and insulin of pigs with contrasting protein deposition (adult vs growing pigs) potential after feeding diets either unbalanced (UNB) or balanced (BAL) in AA using EHFM as a protein source. The UNB diet for both sets of pigs had low levels of certain essential AA like Lys, Met, Tyr, and His while having high levels of branched-chain AA except for Ile. Therefore, their BAL diet was supplemented with these AA to attain a more favourable AA profile for pigs. All diets were formulated to provide the same amount of total AA. Four adult and four growing pigs were fitted with a jugular catheter for serial blood collection. After an overnight fast, pigs were fed 75% of their meal allowance, then blood was collected during 6 h after the meal. Each pig received each diet three times. In both stages, feeding either diet did not affect (P > 0.05) the average concentrations of total plasma AA. Supplementation with essential AA in BAL resulted in greater (P > 0.05) average plasma concentrations of Lys, Met, Ile and His, and of Tyr in growing pigs. However, supplementation of non-essential AA to both diets resulted in lower (P < 0.05) plasma concentrations of Ala, Glu, and Gly (and Ser, which was not supplemented) in BAL compared to UNB. Lower Ser and Gly may be due to the use of these AA for Cys synthesis. The concentrations of Thr, Trp, and Val did not differ between diets (P > 0.05). With the exception of Arg, Asp, and Tyr, growing and adult pigs responded in a similar way to balancing of the diet. Average postprandial plasma concentrations of the other metabolites and insulin were unaffected (P > 0.10) by the diet. In conclusion, AA supplementation to balance a diet results in changes in plasma AA profile in growing and adult pigs. Changes in non-essential AA may be due to their roles in carbon and nitrogen metabolism.
100
Oral Presentation 3 (O3) – 1st July
Session 4 (O3S4)
101
Apple agglutinins (MdAGGs), a new mechanism of resistance against Erwinia amylovora clarified
Erwan Chavoneta*, Romain Warneysa, Alexandre Degravea, Marie-Noëlle Brisseta, Matthieu Gauchera, Raphaël Cournola, Christelle Heintza aUniv Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
Keywords: Agronomy, Phytopathology, Fire blight
Abstract: Fire blight is a destructive apple (Malus domestica) disease with progressive necrosis caused by the colonization of E. amylovora in aerial tissues. The two essential pathogenicity factors of this bacterium are its exopolysaccharides (EPS), a capsular layer that allows E. amylovora to progress in plant tissues, and its type III secretion system (T3SS) which delivers protein effectors in the host cell and promote cell death. Susceptible apple varieties can be protected from fire blight by eliciting their defence with acibenzolar-S-methyl (ASM), a functional analogue of the phytohormone salicylic acid naturally involved in plant defences signalling. Recently, a global analysis of the transcriptome allowed us to identify a new gene family highly responsive to ASM treatment. These genes encode agglutinins (MdAGGs), proteins thought to be involved in plant defence thanks to their ability to bind cell-surface carbohydrate. My research revealed that MdAGGs are excellent resistance markers to fire blight, in so far as their detection is systematically associated with enhanced resistance to E. amylovora. Using bacterial mutants affected either in EPS biosynthesis or T3SS function, I showed that E. amylovora uses both pathogenicity factors to repress MdAGGs expression in apple. Furthermore, structural modelling of MdAGGs suggests that these proteins form homodimers with putative carbohydrate-binding sites on both ends of the dimer. Overall, these features suggest that MdAGGs are involved in apple resistance by their ability to agglutinate bacterial cells. Using purified recombinant MdAGGs, I showed that these defence proteins bind to surface bacterial polysaccharides leading to E. amylovora agglutination. Moreover, E. amylovora was shown to counteract this defence mechanism by releasing important amounts of EPS, thereby sequestrating MdAGGs and preventing agglutination. Altogether, this work allows us to establish a working model in which plant defence activation by ASM prevents the fire blight disease by promoting MdAGGs accumulation in tissues. We hypothesize that this preventive protein accumulation aborts the spread of the disease in so far MdAGGs are rapidly mobilized to agglutinate bacterial cells, even before the bacteria had the time to mount her own counterattack mechanism, ie. to secrete enough EPS preventing MdAGGs-driven agglutination.
102 Energy-efficient superconcentration-granulation based process to manufacture dairy powders: Limiting factors
Maheshchandra Patilab*, Gaëlle Tanguya, Cécile Le Floch-Fouéréa, Romain Jeanteta, Eoin Murphyb a*STLO, INRAE, Institut Agro, 35042, Rennes, France bFood Chemistry and Technology, Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland Keywords: Superconcentration, Novel processing, Alimentation Abstract: Drying is crucial for valorization of high-moisture dairy products. Conventional processes comprise of vacuum-concentration (VC) followed by spray-drying (SD) to remove moisture. SD accounts for half the energy but only removes <10% of total moisture. Marked energy savings (10.7-23.5%) were reported for whey permeate (WP) by replacing SD with superconcentration (~80% w/w dry matter (DM)) and granulation (Towerless drying; PST). Energy savings were directly linked to superconcentration extent, i.e. concentration in excess of VC. This work investigated limiting factor for superconcentration and influence of composition. Physical properties of concentrates were characterized as a function of DM. A lab-scale model was developed to simulate PST. Four dairy products were evaluated to cover range of composition. Maximum superconcentration was linked to onset of highly cohesive (sticky) phase, wherein extreme resistance to flow was detected. Onset of cohesive phase was marked by dramatic rise in viscosity, yield-stress and cohesion. Ring-shear measurements confirmed DM range for highly cohesive phase (flowability-function <1, i.e. hardened/non-flowing state). Cohesive phase was demarcated within DM range, which was highly influenced by composition. Higher protein content resulted in earlier onset of cohesive phase (e.g. skim- milk ~62% DM), whereas higher lactose delayed onset (WP ~80% DM). Consequently, lower protein streams can be superconcentrated to higher DM compared to higher protein streams, which also reflects magnitude of energy savings achievable. Remarkably, a simple technique of measuring agitator power consumption reliably mapped the cohesive phase. Furthermore, effective granulation was related to end of cohesive phase. Interesting reconstitution behavior was revealed as a function of composition. High lactose permeates compared favorably, whereas high protein skim and fat-filled milk powders demonstrated poor solubility. Relevant tools and techniques were provided which can outline operating conditions for optimum performance and screen different ingredients to evaluate application of energy- efficient PST approach to enhance process sustainability and profitability.
103
P and Fe speciation in pre-precipitated sewage sludge: Effect of iron salts' type and concentration
Mohamed Amine SAOUDIa*, S. Picarda, F Vedrenneb, M-L Daumera a INRAE - 17 avenue de Cucillé - 35000 Rennes - France, [email protected] b Veolia Research & Innovation - 293, avenue Ducas - 78520 Limay - France
Keywords: phosphorus iron speciation; phosphorus removal; precipitation; sewage sludge, wastewater, Agronomy.
Abstract:
Phosphorus (P) recovery from sewage sludge is one of P scarcity's most promising solutions in Europe. However, P in sludge is often bound with iron (Fe), added during the P removal process from wastewater. In this study, the effect of iron salts coagulants (Ferric chloride, ferrous sulfate, and ferric/ferrous sulfate mix) at different Fe:P molar ratio (1, 1.5, and 2) on phosphorus and iron speciation of sludges produced from precipitated urban wastewater was studied using a sequential extraction method that distinguished between P bound to ferrous and ferric compounds. Fe(II) compounds were the dominant fraction, yet P bound to Fe(III) prevailed. The percentage of the extracted P and Fe species did not vary significantly with the increase of Fe concentration; however, the Fe:P molar ratio of the extracted species varied depending on the type of Fe slats. This study showed that the P bound to ferrous iron is limited regardless of the type and concentration of iron salt added and that the alternation of the oxidation and reduction phases during the aerobic and anaerobic stages in the wastewater treatment process could strongly impact the distribution of P between Fe(II) and Fe(III) compounds. Hence, strongly impacting the potential of phosphorus recovery from sewage sludge.
104
Multi-agent, multi-level modelling of PRRSv transmission in highly structured farms
Vianney Sicard*
INRAE, Oniris, BIOEPAR, 44300, Nantes, France.
Keywords: Agronomy, mechanistic epidemiological modelling, multi-level agent based simulation
Abstract: Controlling health risks at the animal, farm and territorial levels is essential for the viability of livestock farms and production chains. Porcine reproductive and respiratory syndrome (PRRS) is a recent contagious viral disease (1991 in France), extremely widespread in areas with a dense pig population (nearly 60% prevalence in Brittany), with the threat of the emergence of even more virulent Eastern European strains. The strong structure of French pig farms, i.e. batch management with a strong coupling between individuals, organizational level and environment, is suspected of playing a notable role in the transmission of the pathogen. For studying pathogen transmission and the impact of control measures, stochastic mechanistic modelling represents an efficient approach. Heretofore, it is very complex to explicitly represent the interactions between physiological states related to age, group membership (batch) and environment, as well as to take into account the different scales (batch, litter, sector, building, room, pen, etc.). We propose a generic methodological framework for introducing organizational mechanisms into multi-level multi-agent based simulation architectures, applied to mechanistic epidemiological modelling, with the aim of modelling the spread of PRRSv. This approach provides an explicit and reviewable representation of the structured management of farms by considering both spatial and social organizational aspects (housing, batch). This makes it possible to represent and take into account different pathogen transmission routes according to the spatial and social organization, especially via the environment. Moreover, this method is applied at different levels involved in the organizational structure, thus providing a modular modelling framework with different grains. The corresponding software developments are integrated into a generic epidemiological modelling platform (Emulsion), which allows them to be used for similar pathosystems, and in the longer term at other scales (inter-population or intra-host).
105
Fossil inclusions in amber, a window to the past: The study of Miocene Ethiopian amber (Africa)
Valentine Boujua a* UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France
Keywords: Geosciences, Palaeontology, Amber
Abstract:
In order to better apprehend the past history of the word, palaeontologists have been looking for clues in fossiliferous remains. Among many different process, the amber, or fossilised tree resina, is one of the most renowned, as it offers an exceptional preservation degree of its inclusions: plants, arthropods or even vertebrates, trapped in the resina flow. If numerous amber deposits are known today over the world, they are mostly found in the Northern Hemisphere, corresponding to the former Laurasia, while very few fossiliferous ambers have been found in the former Gondwanan continent. The discovery in 2010 of a new amber deposit in Ethiopia (Africa) represents a promising new source of information in order to fill in the gap of the Gondwanan history. First thought Cretaceous, Ethiopian amber dating has since been corrected to a most probable Miocene age. My research aims to retrace the palaeoenvironment of Miocene Ethiopian forest and apprehend its biodiversity. In this objective arthropod and plant inclusions have been analysed and determined. The amber inclusions, representing a valid sample of the past entomofauna, is dominated by Hymenoptera (mostly Formicidae) and Diptera. Associated to the arthropods specimens have been found fossilised remains of angiosperm plant, moss (Bryophyta), liverwort (Marchantiophyta) and lichen (Ascomycota). The determination of the amber inclusions describes a forest of tropical to sub- tropical climate.
106
Immune priming and the limited diversity of resistance genes in host mixtures
Pauline Clin*, Frédéric Grognard1, Ludovic Mailleret1, Frédéric Hamelin2.
*2IGEPP, INRAE, Institut Agro, Univ Rennes, 35000, Rennes, France; 1Université Côte d’Azur, Inria, INRAE, CNRS, Sorbonne Université, 9 Biocore, France.
Keywords: Ecology, epidemiology, induced immunity. Abstract:
Host mixtures are a promising method for agroecological plant disease control. Plant immunity is key to the success of host mixtures against polymorphic pathogen populations. This results from priming-induced cross-protection, whereby plants able to resist infection by specific pathogen genotypes become more resistant to other pathogen genotypes. Strikingly, this phenomenon was thus far absent from mathematical models aiming at designing host mixtures. First, we developed an epidemiological model in n dimensions to explore the effect of host mixtures with large resistant host genotypes on the equilibrium prevalence of the disease. A significant amount of resistance genes must be deployed to achieve low disease prevalence. Next, as in a simple case of gene-for-gene interaction model, priming minimizes the prevalence of the disease by cross-protection process (Clin et al, 2020), consider it in an n- dimensional model could reduce the number of plant genotypes needed to drop the prevalence below an acceptable level. Given the limited availability of resistance genes in cultivars, this mechanism of plant immunity would make the use of host mixtures more realistic.
107
Effects of self-produced compost and biochar amendments on mobility and uptake of metals and metalloids in moderately contaminated soil of an allotment garden
Alice KOHLI1,2,3*, Liliane JEAN-SORO1,3, René GUÉNON2,3, Laure VIDAL-BEAUDET2,3
1 GERS-LEE, Univ Gustave Eiffel, IFSTTAR, F-44344 Bouguenais, France 2 EPHOR, L’institut Agro, IRSTV, F-49045 Angers, France 3 IRSTV, Nantes, France Keywords: Agronomy; Trace metals and metalloids; allotment
Abstract:
Compost application can potentially reduce trace metals and metalloids (TMM) mobility in contaminated soils and their uptake by vegetables by altering pH and increasing sorption capacity. However, the effects of self-produced composts on TMM remain weakly understood because of their great diversity regarding to biogeochemical properties and rates of application used by gardeners. The aim of this study was to analyze 60 self- produced composts and select five contrasted composts by elemental composition and biochemical properties. These composts were used to conduct experiments on lettuce grown in pots filled by soil moderately contaminated by lead (Pb; 106 mg.kg-1). A standardized compost used as reference (R), two gardener’s composts (G1 and G2), a municipal green waste compost (MGW) and a collective food waste compost (CFW) were applied at 100 and 200 t.ha-1 i.e. 3.3 and 6.6 % dry weight (dw). MGW was also applied at 25, 50, 150 t.ha-1 to look closer into a dose effect. A biochar (B) was also tested alone at 10, 30, 100 t.ha-1 or co-added at 30 t.ha-1 with CFW at 100 t.ha-1 to test its sorption capacity. The TMM concentrations were monitored in soil pore water during 60 days and in lettuce after 35 days of growth. First results showed that CFW, R and G1 additions immediately increased trace elements concentrations in soil pore water with 100 t.ha-1 and more with 200 t.ha-1. CFW application at 200 t.ha-1 especially increased Pb, Cd, Cu and As concentrations by 10, 5, 4 and 3 fold compared to non-amended soil, reaching 3.4, 0.32, 134 and 36 µg.L-1, respectively. Overall, Pb uptake in lettuce was higher in particular for soil amended with 200 t.ha-1 of MGW (0.65 mg.kg-1 dw) and 100 t.ha-1 of CFW (0.64 mg.kg-1 dw) compared with non-amended soil (0.33 mg.kg-1 dw). Arsenic uptake was higher in particular with 200 t.ha-1 of CFW (0.28 mg.kg-1 dw), MGW (0.28 mg.kg- 1 dw), G1 (0.26 mg.kg-1 dw) and R (0.18 mg.kg-1 dw), compared with non-amended soil (0.12 mg.kg-1 dw). This study suggests that amendment by self-produced and also standardized composts of contaminated allotment garden could mobilize TMM and increase their uptake.
108
Posters Presentation 3 (PS3) – 1st July
109
Does encapsulation of DHA with heat-denatured whey proteins in Pickering emulsions improve its bioaccessibility?
Jun WANG*, Gwenaële Henry, Olivia Ménard, Jordane Ossemond, Yann Le Gouar, Didier Dupont, Frédérique Pédrono
STLO, UMR 1253, INRAE, Institut Agro, Agrocampus Ouest, Rennes, France
Keywords: Encapsulation, Digestion, Food sciences
Abstract: Docosahexaenoic acid (DHA) is the most important n-3 polyunsaturated fatty acid (PUFA), mainly known for its health benefits on cognitive development and cardiovascular functions. However, the current intake of DHA and EPA in the Western diet averages 150 mg per day, whereas the recommended daily consumption from The French Food Safety Authority is 500 mg. Therefore, enrichment of food with DHA is considered as an efficient strategy to meet the recommended intake threshold. The main challenge is to preserve DHA oil from oxidation leading to undesirable flavors and reduced bioactive functions. Encapsulation techniques seek to enhance the stability and bioavailability of bioactive food ingredients. In this study, DHA oil composed of DHA-enriched triacylglycerols (TAG) was prepared as Pickering emulsion by encapsulation with heat-denatured whey proteins. Pure oil or emulsion were then incorporated in eggs and cooked in an omelet. The effect of encapsulation of DHA oil was determined by using the static in vitro digestion model of an adult. The FA profile was followed by gas chromatography coupled with mass spectrometry, from the lipid species formed during the digestion and separated by thin layer chromatography. Firstly, results showed that the DHA concentration in omelets with unencapsulated DHA oil (UN-DHA-O) was lower than in omelets with encapsulated DHA oil (EN-DHA-O) due to the loss of unencapsulated DHA oil during the food preparation. However, the food preparation did not show any degradation of DHA in any DHA-rich omelets. Secondly, during digestion in the gastric phase, DHA-enriched TAG was not hydrolyzed in UN-DHA-O nor in EN-DHA-O. In contrast, digestion during the intestinal phase released free DHA from TAG and also from 1,2-diacylglycerols and 2- monoacylglycerols. Release of free DHA was significantly higher with EN-DHA-O than with UN-DHA-O after 2 hours (52.2% and 40.4% of total DHA, respectively). These results suggest that encapsulation through Pickering emulsion can reduce the loss of DHA oil during the food preparation and can also improve the DHA release during the intestinal phase.
110
Vulnerability of coastal areas to increased aquifer saturation due to climate change
Alexandre Gauvaina*, Jean-Raynald de Dreuzya, Luc Aquilinaa and Frédéric Gresselinb
a* Univ Rennes, CNRS, Geosciences Rennes - UMR 6118, F-35000 Rennes, France b DREAL Normandie, Caen, France
Keywords: Geosciences, Hydrological modeling, Groundwater inundation.
Abstract: Like in other relatively flat coastal areas, flooding by aquifer overflow is a recurring problem on the western coast of Normandy (France). Threats are expected to be enhanced by the rise of the sea level and to have critical consequences on the future development and management of the territory. The delineation of the increased saturation areas is a required step to assess the impact of climate change locally. Preliminary models showed that vulnerability does not result only from the sea side but also from the continental side through the modifications of the hydrological regime.
We investigate the processes controlling these coastal flooding phenomena by using hydrogeological models calibrated at large scale with an innovative method reproducing the hydrographic network. Reference study sites selected for their proven sensitivity to flooding have been used to validate the methodology and determine the influence of the different geomorphological configurations frequently encountered along the coastal line.
Hydrogeological models show that the rise of the sea level induces an irregular increase in coastal aquifer saturations extending up to several kilometers inland. Back-littoral channels traditionally used as a large-scale drainage system against high tides limits the propagation of aquifer saturation upstream, provided that channels are not dominantly under maritime influence. High seepage fed by increased recharge occurring in climatic extremes may extend the vulnerable areas and further limit the effectiveness of the drainage system. Local configurations are investigated to categorize the influence of the local geological and geomorphological structures and upscale it at the regional scale.
111
Role of microRNAs in the photo-control of bud burst in Rosa ‘Radrazz’
Julie Malleta*, Patrick Laufsb, Nathalie Leduca, José Le Gourriereca a University of Angers - IRHS 42 rue Georges Morel, 49070 Beaucouzé, France b Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, Université Paris-Saclay, 78000, Versailles, France
Keywords: Agronomy, microRNAs, Bud outgrowth
Abstract: Shoot branching is a major determinant of plant architecture, and as such impacts yield and visual quality, in order to meet consumer expectations. Architecture is an essential element in visual quality of the plant which is important in ornamental plants. Shoot branching is highly dependent of environmental factors, especially light. To study the environmental control of branching, we focus on the rosebush (Rosa ‘Radrazz’), an important plant in ornamental horticulture that has an absolute requirement of light to trigger bud burst. The main objective of our team is to tackle the complexity of the endogenous factors like hormones (SL, IAA, GA, CK, ABA), nutrient (sugar, nitrogen) and ROS regulatory network behind the branching process in response to the environment. While great progress has been made in terms of transcriptional regulation of light-regulated rose bud outgrowth, little is known about the contribution of post- transcriptional regulations to this process. To provide new insights in post- transcriptional mechanisms underlying the control of bud outgrowth, we started elucidating the role of microRNAs. In this purpose, a combined high throughput sequencing of small RNAs and mRNAs transcriptome of axillary buds under different light conditions was used. Thus, a total of 160 conserved microRNAs belonging to 47 microRNAs families and 110 putative novel microRNAs were identified and analysed based on their differential expression in dormant (dark condition) versus outgrowing buds (light condition). Their putative target genes were predicted by bioinformatics analysis. Expression patterns of selected pairs of candidates (microRNAs and target genes) were validated by qRT-PCR. In order to validate microRNAs- target gene interactions, transient co-agroinfiltration assay of Nicotania benthamania leaves were carried out with quantitative GFP fluorescence analysis. Finally, the biological role of selected microRNAs was tested by heterologous overexpression in Arabidopsis thaliana.
112
Long-term changes in marine growth modulates maturation schedule in Atlantic salmon
Tréhin Cécile 1*, Rivot Etienne 1, Santanbien Valentin 1, Lamireau Ludivine 3, Meslier Lisa 1, Besnard Anne-Laure 1, Bolstad Geir 4, Czorlich Yann 4, Gregory Stephen 5, Nevoux Marie 1,2
1* ESE, Ecology and Ecosystem Health, Institut Agro, INRAE, Rennes, France 2 Management of Diadromous Fish in their Environment, OFB, INRAE, Institut Agro, UNIV PAU & PAYS ADOUR/E2S UPPA, Rennes, France 3 U3E, INRAE, Rennes, France 4 Norwegian Institute for Nature Research (NINA), Trondheim Norway 5 Salmon and Trout Research Centre, Game and Wildlife Conservation Trust, Wareham, UK
Keywords: Ecology, life history strategy, Atlantic salmon
Abstract:
Recent decline in abundance of Atlantic salmon and concomitant change in life history may result from a decline in the growth conditions during marine migration. Available literature suggests the existence of a sex-specific reaction norm with body length at the end of first summer at sea that modulates maturation. However, the extent to which this mechanism explains variations in age at maturity remains unclear. Individual growth measurements from historical scales collected from 5 rivers in the Channel (2001-2016) were used as proxy of body length at different life stages. Over the study period, growth over first summer at sea declined in all populations affecting length at end of first summer. Results suggest that individual probability to mature and return after one year at sea increases with growth. Response strongly differ between males and females; Females need to achieve higher growth than males for the same probability to mature. This supports the hypothesis of a sex-specific probabilistic reaction norm with river specific effects, likely to explain part of temporal and spatial variations in proportion of small early maturing fish in salmon populations. Ongoing research seek to a develop a modelling approach to integrate those new knowledge and resolve the intricate mechanisms relating growth, and size selective survival and maturation to explain the variability of abundance and age composition of returns.
113 Evaluation of three short-range (0-6h) rain ensemble forecasts: study of the Aude October 2018 flash floods (southeastern France)
Charpentier--Noyer, M.1*, Payrastre, O.1, Gaume, E.1, Nicolle, P., Bouttier F. 2, Marchal H. 2
1 GERS-LEE, Univ Gustave Eiffel, IFSTTAR, F-44344 Bouguenais, France
2 CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France Keywords: Geosciences, Hydrology, Ensemble forecasting
Abstract: The Aude river flash floods that occurred on October 15 and 16, 2018 are among the most important in southeastern France in recent years. The triggering rainfall event was characterized by a very fast evolution and a low predictability. During the night, the maximum rainfall accumulation observed nearby Carcassonne reached 243.5mm in 6 hours. In addition to significant considerable material damage, 15 people lost their lives during this flood and a hundred people were injured. After the event, the CNRM proposed new forecast ensembles, targeting the possibility of short-term now casting (0- 6h of lead-time) of this phenomenon. Several NWP models of Météo-France are the basis for the creation of these ensembles:
the first ensemble corresponds to the operational AROME-PE product (12 members) the second is a combination of the AROME-PE and AROME-PI models (18 members) the last ensemble corresponds to the second one with a spatial perturbation (90 members)
The work presented here aims to evaluate, from a hydrological point of view, these three rainfall ensembles specifically designed to improve short-range rainfall now casting. Based on the CINECAR distributed hydrological model, we calculate discharge ensembles for nearly 1200 sub-watersheds with an elementary drainage area of 5km². These forecasts are compared for each sub-basin with the CINECAR simulation obtained with ANTILOPE J+1 high resolution observed precipitation data. This evaluation approach enables to compensate the lack of discharge observations during the event and to enlarge the dataset used for evaluation. The evaluation results presented combine synthetic scores (CRPS and rank diagrams) often used for ensemble forecasts, but also a user-oriented evaluation framework based on threshold exceedance detection and anticipation. Thresholds for each sub- watershed correspond to several discharge return periods (SHYREG database). ROC curves are at first established independently of the level of anticipation. In a second time, we look at the anticipation delays. This work finally reveals that (1) synthetic ensemble forecast evaluation scores are not always sufficient to evaluate forecasts; (2) the user-oriented evaluation shows a clear hierarchy between the three forecast product ensembles in terms of threshold exceedance detection, but not in terms of anticipation levels.
114 Does your origin determines your fate: a tale of gene duplication in Rosaceae
Martin LEDUCa, Jérémy CLOTAULTa, Nathalie LEDUCa and Claudine LANDÈSa aUniversité d’Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
Keywords: Agronomy; Bioinformatics; Gene duplication
Abstract: Gene duplication is known to be an important factor of evolution. Different mechanisms for gene duplication have been discovered like whole genome duplication, segmental duplication, tandem duplication, transposon-mediated duplication and retroduplication. For each of these mechanisms, the resulting duplicated region have different characteristics. For instance, the promoting region is not always duplicated alongside the coding sequence. Hence, these differences might affect the retention rate and evolution of the duplicated gene. In this study, we try to investigate if the duplication mechanism influence the evolution of the duplicated gene with an emphasis on sequence divergence and transposable element environment. We developed a pipeline which i) detectes duplicated genes, ii) infer their duplication mechanism, iii) analyse sequence evolution and transposable element environment. We used this method on seven species from the Rosaceae family which have a great diversity of sequenced diploïd, tetraploïd and octoploïd. We demonstrate how this pipeline succeed in detecting homologs using a multi-species based approach, use genomic context to infer duplication mechanisms and finally how these mechanisms affect sequence divergence and transposable element environment.
115
Impact of iron oxide nanoparticles on Pb leaching and phytoextraction by Helianthus annuus
Léa Mouniera,b*, Mathieu Pédrotb, Martine Bouhnik-Le-Cozb, Francisco Cabello Hurtadoa
a UMR CNRS 6553 ECOBIO Université Rennes1, avenue du Général Leclerc, 35042 Rennes cedex, France b UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France
Keywords: Nanoparticles, Phytoremediation and Ecology
Abstract:
Soil pollution with metallic trace elements linked to anthropogenic, urban, industrial and agricultural activities is a major problem of the current century, leading in particular to significant toxicity for the environment. Conventional methods of remediating soils polluted with trace metal elements are extremely costly. On the contrary, bioremediation methods such as phytoremediation are more profitable but take a long time to implement. Stimulation of phytoextraction by using iron oxide colloids could be an interesting alternative. This technique could allow an increase of the amount of metallic trace elements available to the plant while promoting the plant growth. Thus, the aim of this study is to assay the phytoextraction potential of lead, one of the toxic contaminants found in the environment, by sunflower (Helianthus annuus) in association with iron nanoparticles. This association was studied on a long-term (90 days) soil culture where 150 mg of lead per kg of dry soil were introduced by adding Pb(NO3)2 into pristine soil supplemented or not with iron nanoparticles. Succinct additions of Pb(NO3)2 brought the final lead concentration to 375 mg.kg-1 of dry soil. The added iron nanoparticles consisted of a solution of non-stoichiometric magnetite (Fe3-δO4) and represented 1% of the dry soil mass. Geochemical analyses were carried out on the soil as well as on the leaching solutions on a weekly basis. Weekly biological monitoring of the plants was carried out throughout the study. Physico-chemical and biochemical analyses were carried out on the plants at the end of the experiment. All the analyses thus carried out make it possible to evaluate the impact of the synergistic association of the iron nanoparticles on the phytoextraction of lead by sunflower.
116 Spatial variability and changes in storage-discharge relationships of crystalline catchments: implications for resilience and water resources management of Rennes area
Ronan Abhervéa*, Clément Roquesa, Laurent Longuevergnea, Stéphane Louaisilb, Jean-Raynald de Dreuzya, Luc Aquilinaa
a Univ Rennes, CNRS, Geosciences Rennes - UMR 6118, F-35000 Rennes, France b Eau du Bassin Rennais, Collectivité, 35000 Rennes, France
Keywords: water management, groundwater modeling, hydrological forecasting, geosciences
Abstract: While it is well understood and accepted that climate change and growing water needs affect the availability of water resources, the identification of the main physical processes involved remains challenging. It notably requires to filter interannual to interdecadal fluctuations and extreme events to isolate the underlying trends. Metropolitan areas are specifically subject to growing pressures because of the increasing demand, combined with the strong anthropization of land uses.
The Meu-Chèze-Canut catchment supplies the city of Rennes with drinking water. In this field laboratory, we explore the dynamics of the water cycle and water resources availability. In this context, water supply is mostly coming from reservoir storage for which levels shows a medium- term vulnerability in response to frequent relatively dry years. Based on retrospective data analysis, we describe the relationship between climatic forcing (precipitation, temperature) and water availability (aquifer storage, river discharge and reservoir storage) in different parts of the catchment that are characterized by distinct lithological and topographical settings. We then evaluate the resilience of both surface and groundwater resources, their past evolution and their resilience to climate change and increasing societal needs.
Water resources availability in these catchments relies on two geological formations with distinct hydrodynamics properties. To assess the resilience of the system, we specifically analyzed the relationships between monthly effective precipitation and stream discharge. We observe annual hysteresis relationships - that is, a time lag between precipitation and discharge highlighting the capacity of the landscape to temporarily store water - with significant variability in shapes across the catchments. We argue that topographic and lithological factors play key roles in controlling this variability through their impacts on subsurface storage capacity and characteristic drainage timescales. We propose perspectives based on the complementary use of calibrated groundwater models to leverage these results and provide adaptive water management strategies.
117
Posters Presentation 4 (PS4) – 1st July
118
The particle shape of peats: a complementary analysis for their characterization
Stan Duranda* and Jean-Charles Michela aL’Institut Agro, Agrocampus Ouest, Angers, France
Keywords: QicPic, dynamic image analysis, agronomy
Abstract: As for other substrates’ components, peats are classified and selected for mixes from their particle size through sieving processes. However, sieving tools and methods are often different, and, moreover, do not consider particle shape. These irregular shapes and sizes fall together to create a large pore size distribution (over 85% by volume), so that the shape and size of particles greatly influence the resulting matric structure of the materials, and therefore their physical properties (water retention, drainage). Particle size and shape of two types of Sphagnum white and black peats were studied using a dynamic image analyzer, QicPic. Shape parameters (elongation, circularity, roundness and straightness) of both peats were determined, and analyzed related to their particle size distribution. Results showed a similar PSD for both peats, but the particle shape was different: white peat was more elongated, angular and exhibited the largest diversity of shapes, whereas black peat is more rounded and regular. Moreover, particle shape varied according to particle size: larger particles were more elongated and curved, but less straight and circular..
119
Pepsin hydrolysis is possible from pH 5 to pH 2 on caseins, contrarely to egg-white proteins and the hemoglobin standard of activity measurements.
Léa SALELLES, Steven Le FEUNTEUN, Juliane FLOURY
STLO, INRAE, AGROCAMPUS OUEST, 35042, Rennes, France Keywords : Pepsin, Proteolysis, Alimentation
Abstract : Pepsin is secreted by stomach parietal cells and is the first protease encountered by alimentary proteins during digestion. The food intake is slowly acidified within the stomach and it has been demonstrated that gastric pH has a major impact on kinetics of proteolysis1. The goal of this study is to compare pepsin activity in different pH conditions on two mixed alimentary protein substrates : caseins from cow milk (CA) and Egg-white proteins (EW). Kinetics of hydrolysis of EW proteins and CA by pepsin, in a range of pH from 1 to 8, were monitored by pH-STAT during 2 hours. The final degree of hydrolysis (DH) and initial rates of hydrolysis were measured by the OPA method. Concentrations in susbstrate and pepsin were the same in all experiments, and the saline environment was made acccording to the protocole INFOGEST 4. Kinetics of hydrolysis followed power laws in function of time for the major part of the results. For EW proteins, the final DH was optimum at pH 1 (14.4%) and disminish in a linear fashion in function of pH until nearing 0% at pH ≥6. Final DH for CA were not significantly different from pH 1 to 5 (7,5 ± 1,4 %). Then, it diminished from pH 6 until near 0% pH 8. Kinetics of hydrolysis by pepsin depending on pH is different for globular proteins like EW and a mix of non globular proteins like CA. The activity depending on pH obtained is also different from the hemoglobin standard. 1. Nau, F. et al. Spatial-temporal changes in pH, structure and rheology of the gastric chyme in pigs as influenced by egg white gel properties. Food Chem. 280, 210–220 (2019). 2. Fruton, J. S. The Specificity and Mechanism of Pepsin Action. (2006). Available at: https://onlinelibrary.wiley.com/doi/abs/10.1002/9780470122785.ch9. 4. Brodkorb, A. et al. INFOGEST static in vitro simulation of gastrointestinal food digestion. Nat. Protoc. 14, 991–1014 (2019).
120
Plastic debris distribution and behaviour in soil: new key insights from a household wastes-contaminated soil.
Aurélie Wahla*, Mélanie Davranchea, Julien Gigaultb a UMR CNRS 6118 Géosciences, Université Rennes 1, avenue du Général Leclerc, 35042 Rennes cedex, France b TAKUVIK, CNRS, Université Laval – UMI3376, Quebec, Canada
Keywords : Geosciences, nanoplastics, soil contamination
Abstract : Plastic contamination is widely acknowledged as one of the major environmental and human health threats. Yet, from all environmental compartments investigated, terrestrial ecosystems, especially soils, remain poorly studied. However, considering the plastic debris budget, global inputs to soils may intuitively be greater than the ones entering into oceans. Better understanding their fate and behaviour in soils becomes therefore crucial and urgent. While the detection and distribution of microplastic in soils is improving, we have just demonstrated the nanoplastics occurrence. For this purpose, we investigated a soil contaminated with plastic debris from household wastes. To address the increasing volume of urban waste, household wastes were composted for agricultural purposes thirty years ago. However, due to a mismanagement, a large amount of plastics was crushed, composted and spread on agricultural lands. These contaminated soils can be considered as a proxy to investigate the plastics degradation as well as their fate and behaviour under natural soil conditions. Based on this site, we developed the first methodology to extract, characterise and identify nanoplastics in such a complex system. Then, as microplastics are visually identified through the soil profile, what about the nanoplastics? Are they leached to groundwater? We thus compared the nanoplastics occurrence to that of microplastics. This new extraction method was then applied to a soil profile while simultaneously, microplastics from 2 to 5 mm were extracted by sieving and density fractionation. The microplastic amount in the upper most soil horizons was higher than in the deeper. This microplastic distribution was compared to the nanoplastics presence to estimate their potential of transfer in soil. Finally, both micro- and nanoplastics compositions were compared. These results, based on both micro- and nanoplastics composition and distribution, represent the first insights on plastic debris fate and behaviour under soil conditions and allow rising both fundamental knowledge on emerging processes affecting soils and new consideration and perspectives for soil protection as well.
121
How to explain QTL imbalance between ohnologous chromosomes in apple ?
Tanguy Lallemand¹ , Sébastien Aubourg¹ , Gilles Hunault¹ , Jean-Marc Celton¹ and Claudine Landès¹ Université d’Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France.
Keywords: Agronomy; Bioinformatics, duplicated genes
Abstract: Polyploidy is a driver of genetic innovation in eukaryotic organisms, especially in plants. A high quality genome sequence was obtained recently for domesticated apple (Malus domestica Borkh). This genome sequence confirmed a Whole Genome Duplication (WGD) event that occured 50 million years ago. In apple, a Quantitative Trait Loci (QTL) imbalance has been identified. Indeed, for 7 chromosome pairs among the 14 main pairs of ohnologous chromosomes we find significantly more QTL on one chromosome compared to its ohnologue. To understand this imbalance, we studied the rate of gene sequence evolution between syntenic blocks and investigated whether ohnologous transcript expression differences could be correlated with the observed imbalance.
A turnkey snakemake pipeline was written to compute Ka/Ks between triplets composed by Malus genes of each ohnologous pair and their ortholog in Prunus persica as it was the closest related species without a WGD. First, by inputting homologous genes, a multiple alignment of the protein sequences is performed. This proteic alignment is converted into a nucleic alignment using PAL2NAL. Then, Ka/Ks rates are calculated using PAML. A paired t-test was set for a significant difference in Ka/Ks rate among triplets. To investigate a potential transcription imbalance a mapping pipeline was written and used on all publicly available RNA-Seq runs that meet our quality criteria. Pseudo-mapping data is computed with Salmon and differential analysis with DESEQ2. Rather than testing two conditions against each other we tested differential expression between pairs of ohnologous genes for each experimental condition.
Following the Ka/Ks analysis on the apple gene sequences, we conclude that the QTL imbalance cannot be explained by a sequence divergence between ohnologous genes. We then tested transcriptional imbalance by testing if more than 50% of genes were significantly over-expressed in one chromosome pair. By comparing the 16,779 gene pairs from the 122 experiments, we show that a median of 10,376 genes are differentially expressed. This makes it possible to identify several chromosome pairs including 1-7, 8-15, 4-12 6-14 and 2-15 that are transcriptionally unbalanced, which is mostly consistent with the observed QTL imbalance. In addition, we identified 814 genes which expression is systematically higher in one of the two orthologues. We plan to compare the evolution of transposable elements content located within syntenic blocks for which both QTL and transcriptional imbalance was identified.
122
Exploration of the potential for biosurfactant production by fungi from oil-contaminated environments
Mélanie Chotarda*, Marie-Elisabeth Lucchesia, Florian Lelchatb, Stéphane Le Flochb, Jérôme Mouniera a*- Univ. Brest, LUBEM, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, 29280 Plouzané, France b- Cedre, 715 Rue Alain Colas, 29200 Brest E-mail : [email protected]
Keywords: biosurfactants, ecology, fungi
Abstract:
Following oil spill in the environment, dispersants are used to spread the oil in the water column in the form of droplets which thus facilitate oil biodegradation (Dussauze et al., 2011). For now, these dispersants are synthetic and derived from petrochemicals. However, there are concerns about their toxicity and biodegradability in the marine environment. Numerous studies have highlighted biosurfactant (dispersant components) production by microorganisms and more specifically by bacteria (Desai & Banat, 1997; Rizzo et al., 2018; Xia et al., 2019). The potential of fungi has been relatively unexplored, yet they are known for their ability to produce metabolites of interest among which are surfactants (Bhardwaj et al., 2013; Dell'Anno et al., 2018). In this context, the aim of this study was to screen and select fungi able to produce surfactants. For this purpose, 701 isolates were collected at four hydrocarbon-contaminated sites at two time-periods. These isolates were cultured in different media and their supernatants were screened through two widely used tests, the Drop Collapse and Oil Spreading Tests. Among tested isolates, 25.6% were shown to possess surfactant activities and one Trichoderma citrinoviride isolate showed a very promising activity which is currently further investigated.
Références. Bhardwaj, G., Cameotra, S., & Chopra, H. (2013). Biosurfactants from Fungi: A Review. Journal of Petroleum & Environmental Biotechnology. doi:10.4172/2157-7463.1000160
Dell’Anno, F., Sansone, C., Ianora, A., & Dell’Anno, A. (2018). Biosurfactant-induced remediation of contaminated marine sediments: Current knowledge and future perspectives. Marine Environmental Research, 137, 196-205. doi:https://doi.org/10.1016/j.marenvres.2018.03.010
Desai, J. D., & Banat, I. M. (1997). Microbial production of surfactants and their commercial potential. Microbiology and molecular biology reviews : MMBR, 61(1), 47-64. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/9106364
Dussauze, M., Marguerie, J., Auffret, M., Merlin, F., & Le Floch, S. (2011). DISCOBIOL Program: Investigation of Dispersant Use in Coastal and Estuarine. International Oil Spill Conference Proceedings, 2011, abs173. doi:10.7901/2169-3358-2011-1-173
Rizzo, C., Rappazzo, A. C., Michaud, L., De Domenico, E., Rochera, C., Camacho, A., & Lo Giudice, A. (2018). Efficiency in hydrocarbon degradation and biosurfactant production by Joostella sp. A8 when grown in pure culture and consortia. Journal of Environmental Sciences, 67, 115- 126. doi:https://doi.org/10.1016/j.jes.2017.08.007
Xia, M., Fu, D., Chakraborty, R., Singh, R. P., & Terry, N. (2019). Enhanced crude oil depletion by constructed bacterial consortium comprising bioemulsifier producer and petroleum hydrocarbon degraders. Bioresource Technology, 282, 456-463. doi:https://doi.org/10.1016/j.biortech.2019.01.13
123 Survival of Campylobacter jeuni cocultured with Salmonella spp. in aerobic condition
N. Anisa*, L. Bonifaita, S. Quesnea, L. Baugéa, W. Yassineb, M. Chemalya, M. Guyard- Nicodèmea a*Anses, Laboratoire de Ploufragan-Plouzané-Niort, Unité Hygiène et Qualité des Produits Avicoles et Porcins, BP53, 22440 Ploufragan, France b Université Libanaise, Rue du musée national, Beyrouth, Liban, P.O. Box 6573/14 Badaro, Museum, Beyrouth - Lebanon
Keywords: Agronomy, Campylobacter, Salmonella.
Abstract: Campylobacter and Salmonella are both responsible for the two major foodborne zoonotic diseases in Europe with more than 220,682 and 87,923 cases reported in human in 2019 and poultry is generally recognized as the main source of infection. Campylobacter is a microaerophilic bacterium, thus it cannot grow under aerobic conditions but has already demonstrated prolonged aerobic survival when cocultured with Pseudomonas spp. ; however, interaction with Salmonella has not been studied yet. In this work, coculture of these two bacteria under aerobic conditions was performed. Different C. jejuni strains and Salmonella serotypes were tested to cover the main prevalent Campylobacter types and Salmonella serotypes in the poultry production. Campylobacter jejuni strains (4 log CFU/ml) were placed in buffered peptone water with or without Salmonella spp. (around 10 CFU) and incubated at 37 °C for 16 h. Enumerations of Campylobacter and Salmonella were performed, before and after incubation, using serial dilutions and plating on mCCDA and Rapid’Salmonella respectively. As expected, C. jejuni C97Anses640 loads were greatly reduced (3.6 log) after incubation alone in these conditions. However, this reduction was lower (1.5 log) when it was cocultured with Salmonella Blegdam (n=10, p<0.05). Nethertheless, the effect of Salmonella spp. on C. jejuni survival under aerobic conditions was different depending on the Salmonella serotype and on the C. jejuni strain. On the contrary, Salmonella spp. enumerations were not affected by the presence of Campylobacter. These results suggested potential interactions between Salmonella and Campylobacter strains that require further investigations to get a clearer understanding of the behavior of these pathogens in natural habitats such as in live animals and in poultry meat products
124
Performance of automated methods for flash flood inundation mapping: a comparison of a DTM filling and two hydrodynamic methods
Nabil Hocini a*, Olivier Payrastre a, Eric Gaume a, François Bourgin b, Philippe Davy c, Dimitri Lague c, Frédéric Pons d, Léa Poinsignon d
a* GERS-LEE, Univ Gustave Eiffel, IFSTTAR, F-44344 Bouguenais, France b University Paris-Saclay, INRAE, UR HYCAR, Antony, France c Géosciences Rennes - 263 Avenue Général Leclerc - 35042 Rennes – France d CEREMA Cerema Méditerranée - Rue Albert Einstein - 13290 Aix-en-Provence - France
Keywords: Flash Floods, Inundation Mapping, Geosciences
Abstract: Flash floods observed in headwater catchments often cause catastrophic material and human damage worldwide. Considering the large number of small watercourses possibly affected, the use of automated methods for flood inundation mapping at a regional scale can be of great help for the identification of threatened areas and the prediction of potential impacts of these floods. An application of three mapping methods of increasing level of complexity (HAND/MS, caRtino 1D, and Floodos 2D) is presented herein. These methods are used to estimate the flooded areas of three major flash floods observed during the last ten years in South-Eastern France: the 15th of June 2010 flood on the Argens river and its tributaries (585 km of river reaches), the 3rd of October 2015 flood on small coastal rivers of the French Riviera (131 km of river reaches) and the 15th of October 2018 floods on the Aude river and its tributaries (561 km of river reaches). The common features of the three mapping approaches are their high level of automation, their application based on a high-resolution (5 m) DTM, and their reasonable computation times. Hydraulic simulations are run in steady-state regime, based on peak discharges estimated using a rainfall-runoff model preliminary adjusted for each event. The simulation results are compared with the reported flood extent maps and the high water level marks. A clear grading of the tested methods is revealed, illustrating some limits of the HAND/MS approach and an overall better performance of hydraulic models solving the shallow water equations. With these methods, the inundated areas are overall well retrieved, and the errors on water levels remain mostly below 80 cm for the 2D Floodos approach. The most important remaining errors are related to limits of the digital elevation model such as the lack of bathymetric information, uncertainties on embankment elevation and to possible bridge blockages not accounted for in the models.
125
Tidal dissipation in Io and Europa’s silicate mantle: Influence of a partially molten layer
Mathilde Kervazoa*, Gabriel Tobiea, Gaël Chobleta, Caroline Dumoulina a*UMR CNRS 6112 Laboratoire de Planétologie et de Géodynamique, Université de Nantes
Keywords: Geosciences, Planetary Sciences, Jovian satellites
Abstract: The presence of a subsurface ocean on Europa (Khurana et al. 1998; Kivelson et al., 2000) in direct contact with the silicate mantle, along with the spectacular volcanic activity exhibited by its neighboring satellite Io (e.g. Carr, 1986; McEwen et al., 1998; Lopes and Williams 2005), raise the possibility of seafloor volcanic activity (Thomson and Delaney, 2001; Travis et al. 2012), which has significant implications for Europa’s ocean habitability.
Observational constraints concerning the heat budget of satellites exist only in the case of Io. The total power emitted through its surface is estimated to about 100 TW at present (e.g. Veeder et al. 1994), which is several orders of magnitude higher than can be explained by radiogenic heating alone. Unlike Io, the surface heat flux of Europa is unknown. Due to a larger distance from Jupiter and a smaller size, dissipation in Europa's mantle is expected to be considerably smaller than on Io, but still could be comparable to present-day radiogenic heating. Combined radiogenic heating and tidal heating sustain partial melting in Europa's mantle during billions of years (Běhounková et al.2020), especially during periods of enhanced eccentricity, which may lead to melt accumulation in the asthenosphere. Evaluating the coupling between melt generation and tidal heat production is thus essential to assess the possibility of seafloor volcanism on Europa.
We model the viscoelastic deformation of Europa's mantle using Andrade rheology. We test the influence of a partially molten layer, assuming rheological laws including the effect of melt on anelastic properties of rocks. We estimate the maximal heat and melt production that could be generated as a function of time, assuming different scenarios for the eccentricity evolution.
126 Schedule - 30th June
Présentations orales n°1 (O1) – 9h35/10h50
Session 1 (O1S1) Session 2 (O1S2) Session 3 (O1S3) Session 4 (O1S4) 9h35 Phoomipat Alexandre Pilon Diana Ugalde Caroline Constancis Jungcharoen Functionnal and molecular Design of a participatory Organic dairy calves Prediction of magnetite characterization of approach with consumers reared with nurse cows Anopheles gambiae and winegrowers for the and their impacts on (Fe3O4) nanoparticles transformation to muscarinic receptors deployment of more Cryptosporidium infection respectful practices in the maghemite (Fe2O3) in aqeous solutons vineyard : a case study within the Cabernet d’Anjou 9h50 Aira Maye Serviento Coline Caille Claire Ricono Élise Charton
Effect of heat stress and Study of fresh cheese Organic agriculture and Bioavailability of amino feeding management on volatile compound release hedgerows uphold acids, especially of growth and physiological while chewing and endospheric wheat tryptophan, in human milk responses of finishing pigs influence of aroma microbiota at field and and infant formulas molecule equilibruium on landscape scale flavour perception 10h05 Alexiane Luc Benjamin Misteli Marie Louisa Éloïse Couthouis Ramaroson Analyzing free JAR data Effects of macrophytes on Disentangling the effects by combining lexical lentic macroinvertebrate Flavonoids and resistance of farming intensity and preprocessing and assemblage and of the carrot to Alternaria semi-natural habitats at machine learning implications for water dauci different spatial scales on strategies management multifunctionality including both ecological and socio- economic functions
10h20 Xavier Bousselin Anthony Guimpier Lucie Lecoq Ophélie Dubreu
How to enhance N2 fixation Geologically recent Landscape structure Development of a new and N accumulation in earthflow-like landslides on influences grassland plant protection strategy oilseed rape-service plant Mars productivity through through the screening and mixtures intercropping ? changes in plant functional formulation of plant diversity extracts active on the adaptative mechanisms of fungal plant pathogens 10h35 Soumen Mallick Vincent Visconti Gaëlle Gauthier Rémy Cochereau
Phylogenetic isolation of Impact of temperature and An overview of Pickering Biomimetic semi- host-trees reduces concentration of four nanoemulsions : permeable vesicles as resource tracking by surface disinfectants on manufacturing processes, microreactors to modulate herbivorous insects and spoilage mold dry spores formulation and the phase behaviour of their parasitoids applications macromolecules
127
Présentations posters n°1 (PS1) - 11h00/11h45
Session plénière PS1 11h00 Du Phuc Tho Dang 11h25 Jean-Baptiste Domergue
Size fractionation highlights copper Biomarkers of seed quality using mobility from urban stormwater to river isotope-assisted metabolomics in Medicago truncatula
11h05 Julien Bauland 11h30 Marion Valle
The rheological properties of rennet Investigating the origin of soft gels depend on the divalent cation cheese color defect distribution in the casein micelles 11h10 Nicolas Cornette 11h35 Brandon Hayes
Hydrogeological control on stream Developing a multihost African discharge dynamics in bedrock swine fever transmission model at cathcments : exploring the combined the domestic-wildlife interface effects of seepage development and heterogeneity
11h15 Aurore Delvart 11h40 Océane Savary
Elaboration of innovative multi-layered Effect of abiotic factors and culture materials based on functionalized media on the growth of cheese- alpha-glucans associated Nectriaceae spp.
11h20 Florent Blancho
Realistic model for Environmental NanoPlastics (ENPs)
Présentations orales n°2 (O2) – 15h00/16h45
Session 1 (O2S1) Session 2 (O2S2) Session 3 (O2S3) Session 4 (O2S4) 15h00 Adrien Lissarrague Antonin Pépin Sébastian Mira Gauthier Gensollen
Helium charge transfer Environmental assessment Modeling plant-soil Effects of acid dissociation : an emerging of contrasted organic systems using structural environment on digestate fragmentation method vegetable farms in France equation models and reconstituted ration in applied for a better a batch understanding of the hydrolysis/acidogenic structure-function reactor relationships in carrageenans 15h15 Juliette Bougon Fanny Canon Thomas Bernard Guillaume Chesneau Successive inoculations of Positive interactions Synoptic 3D landslide pigs with porcine between lactic acid volume calculation from Single seed microbiota : reproductive and bacteria promoted by repeat LiDAR data dynamics and respiratory syndrome virus nitrogen-based nutritional transmission from mother and swine influenza A dependencies plant to seedling virus result in a two-way
128 interference between both infections 15h30 Gbenga Emmanuel Hélène Cecilia Marie-Charlotte Juliette Palier Omoniyi Guillou Rift Valley fever hosts are CAKERS – Cake reduced Assesing the impacts of not equal – Modelling SCOOP12 moderates cell in sugar, sweet and sour hydromorphological infectiousness at the elongation by controlling restoration in headwater individual level ROS homeostasis and streams promotes plant defenses through a wide transcriptional impact in Arabidopsis 15h45 Ming Yu Iván Osorio Louise Lérault Anani Amegan Missinou Skin formation in drying Transport and reactivity of Effect of the distance from droplets of dairy proteins dissolved oxygen in trophic resources provided Specialized metabiolism in fractured bedrock aquifers to parasitoids on the Brassica napus : a regulation of aphid pests in multiomic approach for the a plum-tree orchard in characterization of Chile phytochemical diversity, its genetic determinants and its regulation by pathogen infection 16h00 Jeanne Maréchal Thibault Barrit Caroline Xavier Giovanni Frati
Contribution of earthworm Role of nitrogen in the Estimation of crossbreed Coastal sand dune bioturbation to the plant-fungal pathogen beef half-carcass chemical monitoring using structure of engineered interaction during seedling composition by dual- hyperspectral and full- soils establishment energy X-ray waveform LiDAR absorptiometry (DXA) scan synchronized remote of halth-carcass or 11th rib sensing: low vegetation cover classification and digital terrain model improvement
16h15 Lorry Bécot Mingrui Chen Simon Ollivier Emmanuelle Richely Genetic variability of Sequential natural deep Molecular networking of nesting behavior and egg eutectic solvents tandem ion mobility data In-depth analysis of the production traits for laying pretreatment/water and its implications for flax fibre intricate hens raised in a cage-free extraction : a novel way to glycomics microstructure in system extract and select pectin relationship with its according to its main mechanical behaviour structural domain 16h30 Harriet Middleton Kathleen Menacer Xabi Cazenave /
A novel mediator of Decrypting the Exploiting favourable rhizopheric plant-microbe mechanisms of host alleles in apple genetic interactions : microRNAs recognition and resources using genomic acceptance by a selection phytophagous insect
129
Présentations posters n°2 (PS2) – 17h00/17h45
Session plénière PS2 17h00 Alice Pradel 17h25 Tarik Kernif
Nanoplastics’ behavior in polar waters: Sedimentary breccias: a marker of modeling the interface between lithospheric extension ? saltwater and sea ice 17h05 Aicha Ait Sair 17h30 Marine Biget
Multicriteria definition of small-scale The drivers of vine-plant root biorefineries based on a statistical microbiota endosphere classification composition include both abiotic and plant-specific factors 17h10 Yuzi Wang 17h35 Nabil Abaab
Screening and investigating starch Origin of the gypsum veins structure and enzymatic degradability associated with the early in a wheat MAGIC population Cretaceous Bouhedma formation, Northern Chotts range, Southern Tunisia 17h15 Stéphane Perrier 17h40 Victor Mataigne
Understanding the compensatory Omics metrics for ecological niche mechanisms in resistant Anopheles potential and metabolic gambiae AcerKis and KdrKis neurons interactions is essential to adapt insecticide-based mosquito control 17h20 Lorene Marchand
A specific rhizomicrobiome selected by a long-lived endemic plant in the sub- antartic Kerguelen Islands
130
Schedule -1st July 2021
Présentations orales n°3 (O3) – 9h00/11h00
Session 1 (O3S1) Session 2 (O3S2) Session 3 (O3S3) Session 4 (O3S4) 9h00 Audrey Quemener Manon Chemin Nicolas Marie Erwan Chavonet
The impact of housing Microwave coagulable High-resolution study of Apple agglutinins conditions on porcine adult alveolar foams the Middle Eocene (MdAGGs), a new stem cell populations differ depostis of the Paris Basin mechanism of resistance between adipose tissue against Erwinia amylovora and skeletal muscle clarified 9h15 Laura Bellec Marie Berger Lisa Martinez Maheshchandra Patil Understanding the Using darkfield and Oilseed rape soil resistance mechanisms of fluorescence macrovision microorganisms promote Energy-efficient the white mustard (Sinapis on large images to assess the establishment of superconcentration- alba) to the pollen beetle anatomical and chemical parasitic plant Phelipanche granulation based process (Brassicogethes aeneus) variability of tissues in ramose on host plant to manufacture dairy whole cross sections of Brassica napus powders : limiting factors maize stems 9h30 Mustapha El Janati Jean Vérité Thibault Le Gratiet Mohamed Amine Saoudi Carbon and dry matter Formation of subglacial Development of new losses during composting triangular-shaped typing tools for Clostridium P and Fe speciation in pre- of date palm residues with bedforms : indicators of botulinum group III strains precipitated sewage rock phosphate and sheep hydrological changes responsible for animal sludge : effect on iron manure as additives during ice sheet retreats botulism outbreaks salts’ type and concentration
9h45 Marawit Tesfa Ousmane Suwareh Toky Vianney Sicard Ramananjatovo Simplified Statistical modelling of in Multi-agent, multi-level spectrophotometric acid- vitro pepsinolysis using Apple trees in garden- modelling of PRRSv base titrations to assess peptidomic data orchard systems improve transmission in highly organic matter reactivity soil quality and yield of structured farms organic radish crop 10h00 Mélanie Huguet Franz Boideau Rima Hachfi Soussi Valentine Boujou
Inability of natural mutant Three is bigger than two Rheological properties of Fossil inclusions in amber, population of aphids to and four : impact of the lactoferrin/β-lactoglobulin a window to the past : the switch their reproductive ploidy level on the complex coacervates study of Miocene Ethiopian mode is probably due to recombination landscape amber (Africa) alteration of genetics in Brassica programs required for sexual embryogenesis 10h15 Laure Boeglin Asma El Aoud Maxime Gautreau Pauline Clin
The importance of tertiary In vitro incorporation of fat- Individualization of flax Immune priming and the roots in young peas for soluble vitamins in mixes tows promoted by physical limited diversity of future service legume bile assemblies pre-treatments : impact on resistance genes in host selection mechanical properties of a mixtures
131 flax/PLA non-woven composite 10h30 Morgane Nennig Souleymane Mballo Youssef Bouargalne Alice Kohli
Recurring Campylobacter Quantification and Functional characterization Effects of self-producted jejuni lineages causing modeling of the climatic of BnD22 a Brassica compost and biochar human infection in services provided by trees napus PI-WSCPs amendments on mobility Luxembourg and revealed in a canyon street “Protease Inhibitors-Water and uptake of metals and by Whole Genome Soluble Chlorophyll metalloids in moderately Sequencing binding Proteins” contaminated soil of an allotment garden 10h45 / Joshua Cooke Francis Amann / Eugenio Soil aggregate stability dynamics of an agricultural Plasma amino acid and silts soil following metabolite profiles of adult application of digestates and growing pigs after feeding a diet with hydrolysed feather meal with a balanced or unbalanced amino acid profile
Présentations posters n°3 (PS3) – 11h15/11h55
Session plénière PS3 11h15 Jun Wang 11h35 Maryse Charpentier- Noyer Does encapsulation of DHA with heat- denaturated whey proteins in Pickering Evaluation of three short-range (0- emulsions improve the bioaccessibility 6h) rain ensemble forecasts: study ? of the Aude October 2018 flash floods (southeastern France) 11h20 Alexandre Gauvain 11h40 Martin Leduc
Vulnerability of coastal areas to Does your origin determines your increased aquifer saturation due to fate: a tale of gene duplication in climate change Rosaceae 11h25 Julie Mallet 11h45 Léa Mounier
Role of microRNAs in the photocontrol Impact of iron oxide nanoparticles of bud outgrowth in Rose on Pb leaching and phytoextraction by Helianthus annuus 11h30 Cécile Tréhin 11h50 Ronan Abhervé
Long-term changes in marine growth Spatial variability and changes in modulates maturation schedule in storage-discharge relationships of Atlantic salmon crystalline catchments: implications for resilience and water resources management of Rennes area
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Présentations posters n°4 (PS4) – 14h50/15h30
Session plénière PS4 14h50 Stan Durand 15h10 Mélanie Chotard
The particle shape of peats: a Exploration of the potential for complementary analysis for their biosurfactant production by fungi characterization from oil-contaminated environments 14h55 Léa Salelles 15h15 Nagham Anis
Pepsin hydrolysis is possible from pH Survival of Campylobacter jejune 5 to pH 2 on casins, contrarley to egg- cocultured with Salmonella spp. in white proteins and the hemoglobin aerobic condition standard of activity measurements 15h00 Aurélie Wahl 15h20 Nabil Hocini
Plastic debris distribution and behavior Performance of automated in soil: new key insights from a methods for flash flood inundation household wastes-contaminated soil mapping: a comparison of a DTM filling and two hydrodynamic methods 15h05 Tanguy Lallemand 15h25 Mathilde Kervazo
How to explain QTL imbalance Tidal dissipation in Io and Europa’s between ohnologous chromosomes in silicate mantle; influence of a apple ? partially molten layer
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