PAM 2017 Programme and Abstract Book

Programme

7th International Conference on Polar & Alpine Microbiology

PAM 2017

8 - 12 September 2017 Nuuk · Greenland

www.pam2017.org Index Welcome to PAM 2017

It is a pleasure to welcome you to the Welcome 3 7th International Conference on Polar and Alpine Microbiology

General Information 4 in Nuuk, Greenland 8 - 12 September 2017 Scientific Programme 5

Social Programme 9 Increasing focus on the Arctic region due to climate change and natural resources such as oil and minerals has made Greenland a hot topic recently and it is of course an excellent place to Oral Abstracts 11 meet and discuss polar and alpine microbiology.

Poster Abstracts 49 The theme of PAM 2017 will be Coming in from the cold: Microbial roles in the warming cryosphere

This theme should reflect that PAM 2017 will place emphasis on novel research showcasing the roles of microbes in the rapidly changing polar and alpine environments. Greenland-related research will be prominent throughout the conference.

We hope you will enjoy the exciting conference programme and the beautiful nature of Nuuk and Greenland!

Kind regards from the Organising Committee

Carsten Suhr Jacobsen (Chairman) Peter Stougaard Aarhus University University of Copenhagen

Aviaja Lyberth Hauptmann Anders Priemé University of Greenland University of Copenhagen

Marek Stibal Tina Santl-Temkiv Charles University in Prague Aarhus University

Graphic Design: viah.dk / Photos: Visit Greenland 3 General Information Scientific Programme

Friday 8 September Information for speakers Please upload your presentation on the pc in the 15.30 - 17.00 Registration and coffee conference hall in the break before the session 17.00 - 17.15 Welcome Mayor of Nuuk Asii Chemnitz Narup & in which you are presenting (at the latest). Conference Chair Carsten Suhr Jacobsen A technician will be there to help you transfer 17.15 - 18.00 Opening keynote: Professor Fernando Ugarte, the presentation to the computer. Please bring Greenland Institute of Natural Ressources your presentation on a USB stick. 18.30 - Welcome reception at conference venue Venue Katuaq After the conference, all presentations will be Saturday 9 September Imaneq 21 deleted from the computer in the conference Postboks 1622 hall in order to secure that no copyright issues 8.30 - 10.30 Session 1: Permafrost microbiology Chair: Anders Priemé and Rachel Mackelprang 3900 Nuuk will arise. Life in pleistocene permafrost: Invited speaker: A tale of survival strategies and carbon metabolism Rachel Mackelprang Certificates of attendance California State University If you wish to have a certificate of attendance, Northridge, USA please contact the PAM 2017 Conference Abstract 1 Metagenomic insights into changing Arctic permafrost Oliver Müller communities Secretariat at [email protected] and we will Tatiana Vishnivetskaya send one to you. Abstract 2 Understanding the persistence of DNA in permafrost of different ages Abstract 3 Distinct microbial communities associated with Jiri Barta cryoturbated organic matter in the Arctic permafrost soils Abstract 4 Active microbial community of denitrifiers, nitrogen Ianina Altshuler fixing-bacteria, and methanotrophs and their effect on the N2O and CH4 soil gas flux in the High Arctic Abstract 5 Dispersal limitation and thermodynamic constraints Eric Bottos govern permafrost community composition across landscape gradients 10.30 - 11.00 Coffee break & exhibition 11.00 - 12.00 Poster flash talks Posters 1-42 12.00 - 13.30 Lunch break & exhibition 13.30 - 15.30 Session 2: Interactions between psychrophilic microorganisms and the environment Chairs: Don Cowan, Oddur Vilhelmsson Structure, function, response and resilience of microbial Invited speaker: Professor Don communities in Antarctic terrestrial soils Cowan, University of Pretoria, South Africa Abstract 6 Interaction of the psychrotroph Pseudomonas Rosanna Hennessy fluorescens In5 with phytopathogens in cold soils Abstract 7 Grazing causes changes in methane production and the Edda Marie Rainer microbial methane filter of High Arctic peatland soils Abstract 8 Some like it cold, some like it colder - strong regionality in Riitta Nissinen the diazotrophic bacterial communities associated with arcto-alpine pioneer plants Abstract 9 Bioremediation pilot scale study of petroleum Robyn Barbato contaminated soils in Utqiagvik, Alaska Abstract 10 Microbial response to glacial/Interglacial periods in Dirk Wagner permafrost deposits - implications for future greenhouse gas production Abstract 11 Biodegradation of pesticides on glaciers Roberto Ambrosini 15.30 - 16.00 Coffee break & exhibition 16.00 - 16.45 Poster flash talks Posters 21-36 16.45 - 18.45 Poster session

5 Scientific Programme Scientific Programme

Sunday 10 September Monday 11 September 8.30 - 9.30 08.30 - 10.30 Session 5: Physiology and evolution of psychrophilic microorganisms 9.30 - 10.00 Coffee break & exhibition Chairs: Lyle G. Whyte, Nina Gunde-Cimerman 10.00 - Session 3: Glacier and snow microbiology Adaptations in cryophilic microorganisms for life in Invited speaker: Professor Lyle 11.45 Chairs: Alexandre M. Anesio, Marek Stibal extreme polar environments G. Whyte, McGill University, The biome of glaciers and ice sheets Invited speaker: Professor Canada Alexandre M. Anesio, Abstract 22 Multiple origins and adaptive strategies of diatoms in Angela Zoumplis University of Bristol, UK the meltwater streams of the McMurdo Dry Valleys, Abstract 12 Co-occurrence networks demonstrate microbial Benoît Bergk-Pinto Antarctica community shifts in arctic snow Abstract 23 Comparative genomics of the polyextremotolerant black Cene Gostinčar Abstract 13 Biogeography of cryoconite bacerial communities on Yongqin Liu yeast Aureobasidium pullulans glaciers of the Tibetan Plateau Abstract 24 Microbial exopolysaccharides from the cold-adapted Maria Michela Corsaro Abstract 14 Metabolically active, rare bacterial taxa underpin Jarishma Gokul Psychrobacter arcticus 273-4 community stability on the Greenland Ice Sheet Abstract 25 What color should snow algae be? Roman Dial Abstract 15 Ecological modelling of the Greenland ice sheet Marek Stibal Abstract 26 Investigation of cold adaptation in Arctic permafrost Isabelle Raymond surface ecosystem bacteria through comparative genome and amino acid 11.45 - 13.00 Lunch break & exhibition analyses 13.00 - 14.00 Session 3: Glacier and snow microbiology continued 10.30 - 11.00 Coffee break & exhibition Chairs: Alexandre M. Anesio, Marek Stibal 11.00 - 12.30 Public poster session Abstract 16 Structural and Functional Characterization of the Soil Johanna Donhauser 12.30 - 13.30 Lunch break & exhibition Microbiome along a Glacier Forefield Chronosequence 13.30 - 15.00 Session 6: Methods to measure Microbial activity at polar including Sources of Colonizers and alpine systems Abstract 17 Craig Cary Chairs: Tim Urich, Carsten Suhr Jacobsen Abstract 18 Snow algae increase melt on the Harding Icefield Gerard Ganey Response of Arctic permafrost soil microbiomes to Invited speaker: Professor elevated temperatur Tim Urich Ernst-Moritz-Arndt 14.00 - 14.30 Coffee break & exhibition University of Greifswald, 14.30 - 16.00 Session 4: Microbiology of sea ice and cold oceans Germany Chairs: Jody Deming, Peter Stougaard Abstract 27 Assessment of the phototrophic potential in the Klemens Weisleitner Microbial adaptations that enable life in subzero brines Invited speaker: cryosphere by laser-induced-fluorescence emission Professor Jody Deming, (L.I.F.E.) Washington State University, Abstract 28 Metagenomic insights into nitrogen fixation in glacial Maisie Nash USA forefields Abstract 19 Microbial functional diversity and resilience in Polar David Pearce Abstract 29 Exploring the Diversity and Functional Capacity of Arctic Rose Layton ecosystems Plasmids Through Cultivation-Independent Approaches Abstract 20 Prokaryotic community structures along salinity Gwangil Jang 15.00 - 15.45 Coffee break & exhibition gradients of melt ponds on sea-ice floes in the Chukchi 15.45 - 17.15 Wild card presentations / Hot topics in cold microbiology Sea Chairs: David Pearce Alexander Michaud Abstract 21 Glacial controls on microbial competition and Abstract 30 Investigating genetic adaptations of airborne Tina Šantl-Temkiv biogeochemical cycles in Arctic fjords microorganisms to long-distance aeolian transport and 16.00 - 18.00 Poster session their impact on atmospheric processes in the high Arctic Abstract 32 New terrestrial Mars analog habitat sites in the Jean-Pierre de Vera Permafrost of Continental Antarctica Abstract 33 Microbial transcriptional responses to thawing and Anders Priemé freezing of active layer soil Abstract 34 The microbiota of on-shore natural gas seepage Oddur Vilhelmsson pockmarks in northern Iceland Abstract 35 Black Bloom Penicillium sp. on the Greenland ice sheet Nina Gunde-Cimerman 18.00 - 18.30 Closing session & announcement of the next PAM conference 19:00 - Conference Dinner at conference venue

7 Scientific Programme Social Programme

Tuesday 12 September Thursday 7 September 2017 14.00 EXCURSION DAY Tour to the Greenland Ice Sheet Margin Tour to Nuuk Basic Research station or Cinema: “Ekspeditionen til verdens ende” / “The expedition to the end of the world” Introduction by Minik Rosing A half-day trip from Kangerlussuaq to the Greenland ice sheet margin, which includes a 1-2 hour walk on the ice, demonstrating the various glacier surface- and marginal habitats with stunning views of Russell Glacier. The tour starts at 14.00 am on 7 September from Kangerlussuaq.

Friday 8 September 2017 18.30 Welcome reception at Katuaq

The welcome reception will be held at the conference venue Katuaq, and it will be an excellent opportunity to catch up with old and new colleagues. Drinks and canapes will be served and participants will have the chance to enjoy live music by a local band playing popular music. The welcome reception is included in the registration fee.

Monday 11 September 19.00-24.00 Conference dinner at Katuaq

The conference dinner will be held at Katuaq and will be an evening of good food and drinks in the company of fellow conference participants. Please note that apart from the welcome drink you will need to buy your own drinks.

Tuesday 12 September 2017 10.00 - 15.00 Tour to the Nuuk basic research station

The tour will be a half day boat trip departing from Nuuk at 10:00 to the Nuuk Basic research station in Kobbefjord. This is an interdisciplinary ecological monitoring station, where impact of climate change on terrestrial and marine ecosystems is studied. You can find more information about the station here: http://nuuk-basic.dk/. The tour will include a guided tour giving an introduction to main research activities at the station, a return boat trip (approx. 30 min. each way) and free tea and coffee during the boat trip. Tickets must be purchased at 750 DKK (incl. VAT) via the online registration prior to the conference.

NB! Please note that all the mentioned tours may be cancelled at short notice due to poor/ dangerous weather conditions. Should this occur, participants will get their tickets reimbursed.

9 Oral Abstracts

11 Oral Abstracts Oral Abstracts

[1] METAGENOMIC INSIGHTS INTO CHANGING ARCTIC PERMAFROST COMMUNITIES [2] UNDERSTANDING THE PERSISTENCE OF DNA IN PERMAFROST OF DIFFERENT AGES

Oliver Müller1, Richard Allen White III2, Janet Jansson2, Bo Elberling3, Lise Ovreas4 Tatiana Vishnivetskaya1, Alexander Eddie1, Daniel Williams1, Elena Spirina2, Elizaveta Rivkina2, Tullis Onstott3, Maggie Lau3, Renxing Liang3, Susan Pfiffner1, Karen Lloyd1 1 University of Bergen, Department of Biology, Bergen, Norway 2 Pacific Northwest National Laboratory, United States 1 University of Tennessee, Knoxville, United States 3 Center for Permafrost; University of Copenhagen, Denmark 2 Institute of Physicochemical and Biological Problems in Soil Science, Pushchino, Russian Federation 4 University of Bergen, Forskergruppen for Marin Mikrobiologi, Institutt for Biologi, ., Norway 3 Princeton University, Princeton, United States

Aim: Thawing permafrost has been found to stimulate microbial activity and cause an increase in greenhouse Aim: Isolation of nucleic acids from permafrost presents a challenge. Permafrost samples differ in origin, gases released to the atmosphere. Detailed knowledge about the microbial community composition and their composition, physicochemical properties, and freezing age, therefore the DNA isolation method that works biogeochemical processes within these changing ecosystems is lacking. To address the implications of thawing for permafrost from one site may be not suitable for sediments from other sites and requires modifications. permafrost, it is important to precisely capture the changes in microbial diversity at a high resolution throug- While frozen in permafrost for thousands to millions of years, the DNA gradually undergoes degradation. hout the soil core and combine this with the metabolic responses upon thaw. Degraded environmental DNA may not provide meaningful genetic information. However, genomic DNA inside viable cells may experience repair of some damage, thereby preserving genetic information. But still this DNA Method: In this study we have applied high throughput sequencing of 16S rRNA genes along a Svalbard soil may be sensitive to mechanical impact and could be sheared to short fragments in bead-beating step during core transect spanning from the active surface layer (AL), via the transition zone (TZ) to the permafrost layer DNA isolation, reducing the possibility of obtaining satisfactory DNA quality. Current research aims to improve (PL) down to two meter, where changes in microbial community composition were documented. Parallel our knowledge of DNA persistence in permafrost in order to compare microbial communities in permafrost of samples were thawed and incubated at 4-6°C and microbial activity response was measured, using gas flux different ages. analysis (CO2; CH4 and N2O) over intervals of hours to months. DNA was extracted after the incubation was terminated and the metagenome sequenced. Method: We collected 132 permafrost samples from a remote site on the right bank of Alazeya River in Northeastern Siberia. The samples have a freshwater lake-alluvial origin with different freezing ages (3 Results / Discussion: The high sampling resolution allowed us to closely follow continuing community thousand to 3 million years old). Permafrost cores were collected with a slow rotary drill that prevented changes within the soil profile, showing significant differences between the AL and the PL (ANOSIM;R =1, down-hole contamination using quality assurance and quality control procedures. The permafrost cores were p=<0.001), which was highly dominated by Intrasporangiaceae and an abrupt shift between 75 and 78 cm, aseptically subsampled in the mobile field laboratory and stored frozen during transportation to the Institute revealing a Bacteroidetes dominated community spanning a ~8cm TZ. In the AL a mean CO2 production rate of Physicochemical and Biological Problems in Soil Science, Pushchino, Russia and from there to the University of ~4.1 µg C g-1 d-1 was measured, whereas in the PL a lower long term production rate (~1.7 µg C -1g d-1) and of Tennessee, TN, USA. For isolation of the total community genomic DNA (gDNA) from permafrost samples, -1 ® an initial burst of CO2 within 24hrs (~15 µg C g ) was observed. Regardless of soil depth, CO2 release was we used PowerSoil® DNA Extraction Kit (MO BIO Laboratories) with modified protocol and FastDNA SPIN Kit much higher under aerobic incubations and CH4 fluxes remained under the detection limit in all samples. for Soil (MP Biomedicals). The extraction efficiency and quality of gDNA extracted by these methods were Metagenomic analysis showed changes in the microbial communities due to thawing, depending on aerobic assessed by fluorescence spectroscopic measurements using PicoGreen assay and quantitative real-time PCR or anaerobic incubation conditions. Genes and their anticipated processes from the deep PL, assumed to be assays. involved in carbon cycling, showed similarities to AL samples, after 16 days of thawing conditions, indicating a future reservoir of function and processes upon predicted thawing. Especially the TZ is revealing a highly Results / Discussion: Adding a bead-beating step increased gDNA recovery from cryosol by 16% (MoBio diverse and active environment with elevated genes mapping to various carbon cycling pathways, enabling PowerSoil) and 37% (FastDNA_SPIN), and ranged from 7-19 µg/g. Yields of gDNA from permafrost samples ® ® the degradation of diverse substrates to CO2. Of particular interest, several iron transporters were identified were lower and ranged from 0.04-0.3 µg/g for FastDNA Spin kit to 0.2-0.5 µg/g for MoBio PowerSoil DNA and the genome from the iron oxidizing Gallionellaceae (family) was recovered, likely explaining the lack of kit. It was observed that purification step of the total genomic DNA from ancient permafrost samples with the

CH4 production. Genomic DNA Clean & Concentrator® Kit (Zymo Research) decreased DNA concentration by 36-85%.

Conclusion: Together, our results indicate that this spatial and temporal variability of CO2 and absent CH4 flu- Conclusion: When working with gDNA from ancient permafrost samples it is essential to decrease the num- xes are reflected in the fine scale variations of microbial communities throughout the permafrost core, where ber of preparation steps between isolation and sequencing. The MoBio PowerSoil® DNA kit gave better results communities and their metabolic activity can change dramatically within 3 cm. Our results lay the foundation in terms of PCR amplification and metagenome sequencing. for a more predictive understanding of how soil microbial communities respond to permafrost thawing and how this ultimately lead to changes in soil biogeochemical processes. This research is supported by NSF DEB 1442262 and NSF IIA 1358155.

13 Oral Abstracts Oral Abstracts

[3] DISTINCT MICROBIAL COMMUNITIES ASSOCIATED WITH CRYOTURBATED ORGANIC MATTER [4] ACTIVE MICROBIAL COMMUNITY OF DENITRIFIERS, NITROGEN FIXING-BACTERIA, AND IN THE ARCTIC PERMAFROST SOILS METHANOTROPHS AND THEIR EFFECT ON THE N2O AND CH4 SOIL GAS FLUX IN THE HIGH ARCTIC. Jiri Barta1, Tim Urich2, Antje Gittel3 1 2 3 4 2 1 University of South Bohemia, České Budějovice, Czech Republic Ianina Altshuler , Jen Ronholm , Chales Greer , Tullis Onstott , Lyle Whyte 2 University of Greifswald, Germany 1 Mcgill University, Ste Anne De Bellevue, Canada 3 Aarhus University, Denmark 2 Mcgill University, Montreal, Canada 3 National Research Council of Canada, Canada Aim: Arctic permafrost soils contain more than 1300 Pg of organic carbon (C) about half of the global soil 4 Princeton University, United States C and twice as much as is currently contained in the atmosphere. Substantial amount of this C is stored in buried pockets of organic matter (OM) by the process of cryoturbation. Besides abiotic conditions, microbial Aim: Climate warming and subsequent permafrost thaw allows the currently frozen carbon and nutrient community structure and the accessibility of OM to the decomposer community are hypothesized to control stores to become available for metabolism by microbial communities. This can result in a positive feedback OM decomposition. loop of greenhouse gas (GHG) soil emissions. Nitrous oxide (N2O) and methane (CH4) are two of the most important GHGs after carbon dioxide. Understanding the flux of these GHGs in the High Arctic and how this Method: We have recently described the composition of microbial communities in cryoturbated OM using flux is related to the active microbial community is key for predicting future GHG emissions and climatic- war high-throughput sequencing and quantification of bacterial, archaeal and fungal marker genes. ming. We aimed to characterize the community of denitrifiers, nitrogen-fixing bacteria, and methanotrophs to

determine the effect this portion of the microbial community has on the2 N O and CH4 gas flux at an ice-wedge Results / Discussion: We found that bacterial abundances in cryoturbations were as high as in organic top- polygon site in the Canadian High Arctic. soils and correlated with the amount of C and N. However, fungi decreased with depth and were significantly lower in cryoturbations than in topsoils. Bacterial community in cryoturbated OM was dominated by Actino- Method: Through a combination of Metatranscriptomics, qPCR, gas flux data, functional gene sequencing, bacteria while fungal community profiling revealed a decrease in ectomycorrhizal fungi. and in situ stable isotope probing (SIP) we demonstrate a functional community of high affinity methanotr-

ophs, denitrifiers, and nitrogen-fixing bacteria which are potentially responsible for a positive N2O flux and a Conclusion: Our study expands the knowledge on the microbial community structure in soils of Northern negative CH4 flux at the High Arctic site. latitude permafrost regions, and attributes the delayed decomposition of OM in buried soils to specific microbial taxa, and particularly to a decrease in abundance and activity of ECM fungi, and to the extent to which Results / Discussion: Metatranscriptome RNA sequencing of soils overlaying permafrost identified the fun- bacterial decomposers are able to act as their functional substitutes. ctional microbes currently present in two soil types at the site: the drier soil of the polygon interior and the wetter trough soil that overlays the ice-wedges. We detected functional gene transcripts involved in nitrogen fixation, denitrification, and methanotrophy processes in both soil types. Quantitative PCR indicated a higher relative abundance of denitrificationNirS ( , NosZ) and methanotrophy (PmoA, MmoX) genes in the wetter trough soils compared to the drier polygon interior soils. Furthermore, there was a higher relative abundance of these genes in surface soils compared to deeper soils close to the permafrost table. This coincided with -2 -1 -2 -1 ● ● ● ● higher N2O emissions (1.33 mg m day ) and higher CH4 uptake (-124.73 mg m day ) in the trough soils compared to polygon interior soils. Functional gene sequencing of denitrificationNirS gene and nitrogen fixationHifH gene also reflected the differences in the microbial community between the polygon interior and the trough soils. The microbial community containing NirS genes was dominated by Rhodocyclaceae in trough soils, while the polygon soils were dominated by Rhizobiales and Acidiferrobacteraceae. The NifH containing microbial members in trough soils were dominated by Desulfobacterales, Rhizobiales, and Gallionellaceae, while in the polygon soils only the Rhizobiales were dominant. Finally, in situ SIP with heavy C13 methane and subsequent methanemonooxygenase (PmoA) amplicon sequencing was able to demonstrate that all the labelled PmoA genes in the soils were related to high-affinity methanotrophs (USCα cluster), with the closest phylogenetic relationship being to Methylocapsa acidiphila. This suggests that this group of organism is responsible for the apparent methane sink in the soils.

Conclusion: The active microbial community in the High Arctic ice-wedge polygon soils is likely responsible for

apparent N2O emissions and CH4 uptake in the Canadian High Arctic. The differences between the observed flux of N2O and CH4 between the wetter through soils overlaying the ice-wedges and the drier polygon interior soils is mirrored in the differences of the dominant microbial community members and the relative abundance of functional genes responsible for these biogeochemical processes in these soils. Furthermore, based on in situ SIP labeling, the dominant active methanotrophic community in the soils are related to the proposed

high-affinity methanotrophs of the USCα cluster which are thought to be capable of atmospherics 4CH uptake.

15 Oral Abstracts Oral Abstracts

[5] DISPERSAL LIMITATION AND THERMODYNAMIC CONSTRAINTS GOVERN PERMAFROST [6] INTERACTION OF THE PSYCHROTROPH PSEUDOMONAS FLUORESCENS IN5 WITH COMMUNITY COMPOSITION ACROSS LANDSCAPE GRADIENTS PHYTOPATHOGENS IN COLD SOILS

Eric Bottos1, Elvira Romero1, Lisa Bramer1, Sarah Fansler1, Joe Brown1, David Kennedy1, Rosalie Chu2, Malak Rosanna Hennessy1, Stefan Olsson2, Peter Stougaard3 Tfaily2, Janet Jansson1, James Stegen1 1 University of Copenhagen, Department of Plant and Environmental Science, Department of Plant and Environmental 1 Pacific Northwest National Laboratory, Richland, United States Sciences, Frederiksberg C, Denmark 2 Environmental Molecular Sciences Laboratory, Richland, United States 2 State Key Laboratory of Ecological Pest Control of Fujian and Taiwan Crops, Fuijan Agriculture and Forestry University, Fuijan, China 3 University of Copenhagen, Department of Plant and Environmental Sciences, Frederiksberg, Denmark Aim: Our aim was to improve understanding of the ecological processes and environmental factors influencing patterns of community composition in permafrost-affected soils across landscape gradients; specifically, Aim: Potato cultivation in southwest Greenland, at Inneruulalik, omits the use of pesticides while relying on we test our hypothesis that microbial community composition in permafrost soils is decoupled from physico- limited crop rotations and despite the presence of plant pathogens in the soil does not suffer from major disease chemical conditions that are found to be important in non-permafrost soils, and is instead similarly shaped by outbreaks. Previously, we have shown that the soil at Inneruulalik is disease suppressive owing to the presence shared constraints imposed by prolonged freezing. of diverse antimicrobial microorganisms. Using culture-based approaches, the psychrotrophPseuomonas fluorescens In5 was previously isolated from the soil microbiome. The aim of this study is to unravel key biocontrol Method: We characterized patterns of environmental variation and microbial community composition along traits underpinning the antagonistic activity of this cold-active bacterium against phytopathogens. a hydrological gradient in a boreal forest ecosystem in Alaska. We used a null modelling approach to estimate the relative importance of dispersal and selection on variation in community composition (which returns Method: A combination of different technologies including genomics, transcriptomics and metabolomics are values from 0 to 1 indicating the relative influence of different processes), and linked the variation explained being used to explore the interaction of the psychrotrophP. fluorescens In5 in dual-culture with diverse plant by selective influences to environmental characteristics through regression and structural equation modelling. pathogens. To date, molecular genetics coupled with MALDI imaging mass spectrometry (MALDI-IMS) have Environmental variables included in the analyses consisted of physicochemical factors such as pH, water con- successfully identified a large antifungal genomic island encoding two secondary metabolites (nunamycin and tent, soil geochemistry (anions and cations), texture, and bulk carbon and nitrogen measurements, as well as nunapeptin) assembled by non-ribosomal peptide synthetases (NRPS). Functional analysis of genes located characterization of soil organic matter composition, determined by Fourier transform ion cyclotron resonance on the island uncovered a LuxR-type regulator required for secondary metabolite biosynthesis. The develop- mass spectrometry (FTICR-MS) and high performance liquid chromatography (HPLC). ment of reporter strains and a microplate reader-based method for studying microbial interactions enabled further characterization of the regulator during bacterial-fungal interactions. Finally, whole-transcriptome Results / Discussion: The null modeling results indicated the strongest single processes influencing commu- analysis using RNA sequencing was conducted to investigate the response of the bacterium to different plant nity composition was dispersal limitation (0.36), while the signal for homogenizing dispersal was lowest (0.05). pathogens in dual-culture. The signal for homogenous selection (0.21) was slightly higher than for variable selection (0.16), contributing to a signal of 0.37 for total selection. Fe(II) content, used to indicate soil redox conditions, was the most -im Results / Discussion: Key biocontrol components of P. fluorescens In5 identified to date include the two secon- portant variable explaining variation in total selection, and the only variable found to be significantly associa- dary metabolites nunamycin and nunapeptin that form part of a complex interaction whereby nunamycin -ap ted with total selection by univariate regression (R2=0.14, p=0.003). Our data supported a structural equation pears most active against the basidiomyceteRhizoctonia solani in contrast to nunapeptin, which is most potent model in which carbon composition, particularly the average Gibbs free energy of the carbon pool and organic against the oomycete Pythium aphanidermatum. Regulation of peptide synthesis is mediated by a LuxR-type acid content, influences Fe(II) content and total selection. regulator that switches on when the bacterium enters the deceleration growth phase and upon physical encounter with fungal hyphae. Furthermore, the regulator is strongly upregulated in response to carbon sources Conclusion: These findings suggest that microbial community composition in permafrost soils is uniquely indicating the presence of a fungus suggesting that environmental elicitors may also influence regulator expres- influenced by a balance between dispersal limitation and deterministic selection, with soil redox conditions sion, which upon activation controls nunamycin and nunapeptin production required for the growth inhibition likely to be the most important aspect of the environment deterministically influencing community compositi- of phytopathogens. Recent transcriptomic profiling of In5 in dual-culture with two different phytopathogens on. This work improves understanding of permafrost microbial ecology and is being used to inform incubation revealed the specific response of the bacterium toR. solani and identified novel gene targets for functional experiments aimed at determining how pre-thaw soil conditions and microbial community characteristics may analysis that may play specific roles in the bioactivity or alternatively defense of In5 against phytopathogens. influence post-thaw microbial community structure and function in permafrost environments. Conclusion: Climate change is altering the Arctic at a rate unmatched anywhere in the world with global warming paving the way for new agricultural opportunities in Low Arctic and Subarctic regions. However, rising temperatures could lead to increased problems with soil-borne pathogens and importantly the application of synthetic fungicides in cold areas may be problematic due to slow degradation. Thus, the application of- en vironmentally friendly biological control agents may provide an alternative sustainable solution for combatting plant pathogenic fungi. Current studies are aimed at unravelling further the complex mode of action underpinning the antagonistic activity of In5 in order to develop effective microbial biocontrol agents (mBCAs) for the management of soil-borne plant diseases.

Key References Hennessy RC, Stougaard P and Olsson S. A Microplate Reader-Based System for Visualizing Transcriptional Activity During in vivo Microbial Interactions in Space and Time. Scientific Reports 2017; doi:10.1038/ s41598-017-00296-4.

Michelsen CF, Watrous J, Glaring MA, Kersten R, Koyama N, Dorrestein PC, Stougaard P. Nonribosomal peptides, key biocontrol components for Pseudomonas fluorescens In5, isolated from a Greenlandic suppressive soil. mBio 2015; doi:10.1128/mBio.00079-15. 17 Oral Abstracts Oral Abstracts

[7] GRAZING CAUSES CHANGES IN METHANE PRODUCTION AND THE MICROBIAL METHANE [8] SOME LIKE IT COLD, SOME LIKE IT COLDER - STRONG REGIONALITY IN THE DIAZOTROPHIC FILTER OF HIGH ARCTIC PEATLAND SOILS BACTERIAL COMMUNITIES ASSOCIATED WITH ARCTO-ALPINE PIONEER PLANTS

Edda Marie Rainer1, Alexander Tøsdal Tveit1, Mette Marianne Svenning1 Riitta Nissinen1, Manoj Kumar2, Günter Brader3, Angela Sessitsch3, Jan Dirk van Elsas4 1 Uit - The Arctic University of Norway, Tromsø, Norway 1 University of Jyväskylä, Dept Biol Env Sci, Jyväskylä, Finland 2 University of Jyväskylä, Department of Biological and Environmental Sciences, Jyväskylä, Finland Aim: The population of Arctic breeding geese has increased drastically the last 100 years, most likely due to a 3 Austrian Institute of Technology, Tulln, Austria warming climate, changes in land-use and protection from hunting1 . With geese being one of the dominant 4 University of Groningen, Groningen, Netherlands groups of terrestrial herbivores in the Arctic, shifts from grass- to moss- dominated peatland vegetation occur due to increased grazing pressure. The soil organic carbon pool in Arctic peatlands is influenced by geese gra- Aim: Arctic and alpine biomes cover 8% of the terrestrial surface. Both biomes are characterized by low temperatures and short growing season, but they differ in seasonality of solar radiation and in soil water zing, which reduces plant biomass and hence reduces CO2 uptake and results in increased carbon loss due to soil erosion 2,3. Aerobic Methane Oxidizing Bacteria (MOB) located at the oxic-anoxic interface in peat soils are balance due to underlying permafrost in the Arctic. Arcto-alpine plant species are well adapted to prevailing low temperatures in their habitats, and plant growth is mainly limited by availability of nutrients, in particular the only sink for biogenic methane (CH4) produced anaerobically from organic carbon degradation. The MOB nitrogen, due to slow mineralization. community composes a crucial CH4 filter, reducing CH4 emissions from soil to the atmosphere. An important MOB is Methylobacter tundripaludum SV96, repeatedly identified in neutral high-latitude ecosystems in the Northern hemisphere and proven active in situ 4-6. Plant associated microbiota are known to be vital in the nutrient acquisition and stress tolerance of their host plants in all climates. Arcto-alpine plants are known to host endophytic bacterial communities resembling their temperate counterparts in richness and diversity. Phylogenetic studies indicate that these bacteria are Knowledge about how herbivore pressure affects the MOB community and the CH4 filter efficiency is lacking. Our aim in this study was to investigate the response of the MOB community to changes in plant composition, closely related to plant associated bacteria from other cold climates (Nissinen et al., 2012), and that these endophytic communities are shaped by host plant species as well as geoclimatic regions (Kumar et al., 2017). soil structure, hydrology, oxygen (O2) and CH4 availability related to geese grazing. However, relatively little is known of their functions. Method: The Solvatn peatland close to the research settlement Ny-Ålesund, Svalbard was selected as study site. In this peatland, fenced exclosures were established in 1998 2 to protect parts of the peatland from In this study, we characterized the potential nitrogen fixing bacterial (PNFB) communities associated with two grazing. In our study, exclosed and grazed control sites were compared. We measured temperature, water arcto-alpine pioneer plant species, Oxyria digyna (mountain sorrel) and Saxifraga oppositifolia (blue saxifrage) in three climate regions. Both of these plants readily colonize low nutrient mineral soils. Our goal was to investi- content, O2 concentrations and CH4 pore water concentration along vertical soil gradients. Microcosms were gate, how (1) soil properties (2) climate (region) and (3) host plant and plant species shape these communities. set up ex situ to measure CH4 oxidation potentials along the vertical soil gradients from exclosures and grazed sites. Soil samples from selected depths were enriched for MOB under selective conditions. The bacterial community in situ and in microcosm experiments was identified by 16S-rDNA andpmoA -cDNA amplicon Method: We sampled root endosphere, rhizosphere and bulk soils in all three regions in late June-early July, sequencing to elucidate the active MOB responsible for when the target plant species were flowering, and characterized the communities by massive parallel sequencing of nifH amplicon libraries. We used an optimized PCR program with nested approach to achieve as high coverage as possible. Results / Discussion: The grazed sites had lower O2 concentrations and higher water table, indicating favo- rable conditions for CH4 production, also supported by higher CH4 pore water concentrations compared to Results / Discussion: The data revealed strong regional effects on the PNFB communities. Species richness exclosed sites. The microcosm experiment revealed a shift in the vertical position of the aerobic CH4 filter, as and diversity of soil PNFB communities decreased significantly towards high latitudes (suggesting smaller highest CH4 oxidation rates were measured at 0-2 cm depth in grazed ecosystems compared to 4-8 cm depth -1 selection of available PNFB partners for the plants in the High Arctic). In contrast, the diversity of endosphere in exclosed ecosystems. The CH4 oxidation activity was higher in grazed ecosystems (114,5 – 318,1 µg 4CH /h -1 -1 -1 PNFB communities was highest in the low Arctic in Kilpisjärvi. g dry soil) than in exclosed ecosystems (21,73– 105,2 µg CH4/h g dry soil). In both ecosystems, the strains responsible for methane oxidation were M. tundripaludum SV96 (99-100% pmoA sequence identity)6 , and another Methylobacter strain identical to sequences from the Canadian High Arctic (99-100%pmoA sequence Climate and region strongly shaped the taxonomic composition and community structures of the PNFB 7 communities: proteobacterial genera were prevalent in Mayrhofen plant and soil identity) . Currently, we are sequencing pmoA transcripts from zones of maximal CH4 oxidation to map the Geobacter and Leptothrix communities, while members of the were more abundant in the arctic regions (Kilpisjärvi and strain diversity of the active CH4 filter. Clostridiales Ny-Ålesund), and were virtually absent in Mayrhofen samples.

Conclusion: We have shown that Arctic MOBs efficiently oxidize CH4 in both grazed and non-grazed ecosy- The regionality in PNFB correlated with 16S rRNA gene based analyses of these endosphere communities stems. The activity of the microbial filter varies dependent on plant community, hydrology,2 O and CH4 availa- (Kumar et al., 2017), suggesting a major role for nitrogen fixing bacteria for these plants. Overall, anaerobic bility, thus geese grazing indirectly influences both the CH4 filter activity and vertical soil depth position bacterial taxa dominated the PNFB communities of the endo- and rhizospheres of the two plant species in References: all study sites, especially in High Arctic. We speculate that this is due to anoxic conditions created by melting 1. D. O. Hessen, et al., Ambio, 2017, 46, 40-47 snow and underlying permafrost in the arctic soils at the time of sampling (early growth season). 2. S. Sjogersten, et al., Biogeochemistry, 2011, 106, 357-370 3. R. van der Wal, et al., Glob. Change Biol., 2007, 13, 539-545 Plant and soil (bulk or rhizosphere soil) communities in the Arctic were highly divergent. For example, 4. C. Graef, et al., Environ. Microbiol. Rep., 2011, 3, 466-472 Clostridia spp. were detected mainly in the endorhiza. Interestingly, the major PNFB genera identified in this 5. A. Tveit, et al., Isme Journal, 2013, 7, 299-311 study have been previously identified as members of conserved core microbiome in the endosphere and 6. I. Wartiainen, et al.,International Journal of Systematic and Evolutionary Microbiology, 2006, 56, seeds of these plants by 16S rRNA based analyses and bacterial isolation, suggesting a very tight interaction 109-113 between diazotrophic bacteria and these arctic pioneer plants. 7. C. Martineau,Applied and Environmental Microbiology, 2010, 76, 5773-5784 Conclusion: Potential nitrogen fixing bacterial communities associated with arctic plants are climate specific. Many of them are also tightly associated with their host plants, being part of the core microbiome and seed transmitted, indicating their importance to the host plants in the nitrogen limited arctic biomes. 19 Oral Abstracts Oral Abstracts

[9] BIOREMEDIATION PILOT SCALE STUDY OF PETROLEUM CONTAMINATED SOILS IN [10] MICROBIAL RESPONSE TO GLACIAL/INTERGLACIAL PERIODS IN PERMAFROST DEPOSITS - UTQIAGVIK, ALASKA IMPLICATIONS FOR FUTURE GREENHOUSE GAS PRODUCTION

Robyn Barbato1, Stacey Jarvis1, Robert Jones1, Karen Foley1, Charles Reynolds1 Dirk Wagner1, Alawi Mashal1, Patryk Krauze1, Nadja Torres Reyes1, Janina Stapel1, Fabian Horn2, Svetlana Evgrafova3, Lutz Schirrmeister4, Paul Overduin4, Kai Mangelsdorf2, Sizhong Yang2, Susanne Liebner 3 1 US Army Cold Regions Research and Engineering Laboratory, Hanover, United States 1 Gfz, German Research Center for Geosciences, Potsdam, Germany Aim: Sites at the former Naval Arctic Research Laboratory (NARL) have been historically contaminated with 2 Gfz German Research Centre for Geosciences, Section 5.3 Geomicrobiology,, Potsdam, Germany petroleum hydrocarbons. This laboratory, located between the village of Utqiagvik and Point Utqiagvik the 3 Sukachev Institute of Forest Fic Sb Ras, Krasnoyarsk, Russian Federation northernmost point of Alaska, was a center for scientific study in the region. Here, historical fuel contaminati- 4 Alfred Wegener Institute on has occurred at the Powerhouse (PH) and Airstrip (AS) sites. Because of the unique conditions at the sites, namely the cold, dry climate, oligotrophic soils, and permafrost, these weathered petroleum products have Aim: The currently observed climate change due to global warming is expected to have a strong impact, remained in the soils for over fifty years. The purpose of our field study was to implement bioremediation notably on Arctic permafrost environments. The thawing of permafrost is suggested to be associated with a technologies to stimulate hydrocarbon degradation in contaminated soils at the PH and AS Sites by adding massive release of greenhouse gases, in particular carbon dioxide and methane. Thus, Arctic permafrost regi- fertilizer, a mixture of cold-tolerant plants, and a combination of both. ons play a fundamental role within the global carbon cycle and the future development of Earth’s climate. To understand how the system will respond to climate changes it is not only important to investigate the current Method: During a field campaign from in 2016, 15 remediation blocks each containing four treatment plots status of carbon turnover but also how the system reacted to previous climate changes. were constructed at the AS and PH sites in elevated contaminant plume areas. Each block consisted of a Con- trol Plot (CTRL) where no amendment was added, a Nutrient Plot (N) where fertilizer was added dependent The aim of this study is to investigate the role of microorganisms involved in the transformation of organic on soil moisture, a Plant Plot (P) where a mixture of plant seeds was evenly applied, and a Nutrient and Plant carbon with special emphasis on Arctic warming and to understand the link between substrate composition Plot (N+P) where both the nutrient and plant applications were combined. Composite soil samples were colle- and bioavailability in the microbial metabolic pathways within the carbon cycle. cted immediately after treatment implementation and then at the end of the growing season (approximately 2.5 months later), mixed well, and subsampled for petroleum chemistry (aliphatic and aromatic fractions of Method: Two permafrost cores were derived by drilling campaigns at the coast of Buor Khaya and on the hydrocarbons), soil properties (pH, water content, and organic matter content), and soil biological analysis island Bol’shoy-Lyakhovsky in the North-Eastern Siberian Arctic. The study areas are underlain by continuous (respiration, gene abundance, and bacterial community composition). permafrost with ground temperatures less than -11°C and an estimated thickness of 450 to 650 m. The core of Buor Khaya was 20 m long and contained an ice wedge between 3.5 and 8.5 m, separating Holocene from Results / Discussion: Concentrations of at least one or more petroleum compounds were detected in these deeper Late Pleistocene deposits. The total organic carbon (TOC) in the permafrost sequence ranges between soils. The combination of N+P was the most effective treatment in the contaminated PH and AS soils. In the 0.5 to 5.6%. On Bol’shoy-Lyakhovsky four cores were drilled on different terraces covering permafrost from PH soils, the N+P treatment effectively promoted the reduction of gasoline range organics, diesel range orga- different climate periods reaching from Eemian deposits (130 ka – 115 ka) to Holocene sediments. For these nics, residual range organics compounds, heavy aliphatic fractions, and heavy aromatic fractions. The addition deposits TOC contents ranged between 0.1% and 4.8%.To get a comprehensive insight into the community of nutrients alone was also effective for the lighter aromatic fractions. At AS, the N+P treatment enhanced the structure of the microbial population of the permafrost deposits, Illumina MiSeq DNA sequencing of the 16S degradation of volatile organic compounds, heavier range organics, and many of the aliphatic and aromatic rRNA gene was conducted. Quantitative PCR was used to determine the general abundances of bacteria and fractions. The P treatment was superior in removing lighter range organics. archaea and of specific functional genes. To assess the abundance and distribution of living and past microbial communities in permafrost sequences microbial lipid biomarkers were investigated. Generally, the treatments stimulated microbial activity at both sites. Two alkane-degrading genesCYP153 ( and alkB) were detected in high numbers in these soils, particularly in the N and N+P treatments at PH, likely Results / Discussion: Deposits from glacial and interglacial periods differed in terms of their respective micro- because soil bacteria have been exposed to elevated concentrations of hydrocarbons for decades. The en- bial community compositions and their biomarker inventory. The relative abundances of Firmicutes increased richment of genes capable of degrading alkanes was further supported by the strong correlation between the in interglacial sediments, whereas Chloroflexi showed higher abundances in glacial deposits. This observation CYP153 gene and total aliphatic hydrocarbons. was confirmed by statistical analyses on a whole community level. Thereby, a clustering of microbial communities from the different localities according to the glacial/interglacial chronosequence was revealed. Intere- Bacterial sequencing was used to assess whether the treatment implementation affected microbial diversity stingly, elevated abundances of Bacteroidetes and Proteobacteria were observed in active layer associated in the soils. In PH soils, microbial composition clearly shifted as a function of treatment implementation, while soils. In addition, substantially higher 16S rRNA gene quantities were observed in the active layers. These AS soils only showed minor clustering. At the conclusion of the study, the composition of known hydrocarbon findings indicate changes to community structure and microbial activity, once permafrost starts to thaw. Life degrading organisms was higher in the treated soils when compared to the control in all soils tested. markers show highest abundance and activity of microorganisms in the active layer. Past microbial biomarkers are associated with organic carbon rich permafrost deposits. In contrast to the interglacial Eemian sediments, Conclusion: The field study demonstrated the success of treatment implementation under challenging Arctic especially the glacial Yedoma deposits are rich in OM of high quality with respect to microbial degradation conditions and fluctuating environmental variables. Degradation patterns were heterogeneous, but overall, and methane generation when thawed during ongoing global warming. the N+P treatment was most effective at stimulating degradation of range organics as well as particular -alipha tic and aromatic fractions of hydrocarbons. In some zones, the selection of treatments is highly dependent on Conclusion: Our results contribute to the understanding of the role of permafrost in the global system and the highest priority range organics and fractions of petroleum hydrocarbons. These results are comparable to possible feedbacks by organic matter transformation and greenhouse gas emissions. our laboratory study, which demonstrated the efficacy of the N+P treatment under controlled conditions.

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[11] BIODEGRADATION OF PESTICIDES ON GLACIERS [12] CO-OCCURRENCE NETWORKS DEMONSTRATE MICROBIAL COMMUNITY SHIFTS IN ARCTIC SNOW Claudia Ferrario1, Francesca Pittino1, Ilario Tagliaferri1, Isabella Gandolfi1, Giuseppina Bestetti1, Roberto Sergio Azzoni2, Guglielmina Diolaiuti2, Andrea Franzetti1, Roberto Ambrosini1, Sara Villa1 Benoît Bergk Pinto1, Timothy Vogel1, Catherine Larose1 1 University of Milano Bicocca, Milano, Italy 1 Environmental Microbial Genomics, Laboratoire Ampère, , Ecole Centrale de Lyon, Université de Lyon, Lyon, France 2 University of Milan, Milano, Italy

Aim: To investigate biodegradative processes of organic contaminants deposited on glacier snow and ice. -In Aim: Snow is a dynamic environment undergoing changes due to climate change. Both bacterial interactions deed, in all environments, organic contaminants undergo different partition and degradation processes, which and biogeochemical processes could be influenced by these changes. Here, we present the dynamic evolution ultimately determine their environmental fate and accumulation. High mountains act as cold condensers of of bacterial interactions within snow microbial communities from Svalbard during the spring season. semi volatile organic compounds, which can be efficiently scavenged from the atmosphere by snow. When delivered on glaciers, pollutants undergo partitioning among different environmental matrices (e.g. snow, ice, Method: We tracked the bacterial composition of snow communities by 16S rRNA gene sequencing and the water, atmosphere and supraglacial sediments) and post-depositional alteration processes. Currently, models potential biological activity by generating metagenomic and metatranscriptomic profiles from snow in -Sval of environmental fate of these contaminants in glacier environments focus on physical-chemical post-depositi- bard during the early spring (ES) and the late spring (LS). In parallel, the snow physico-chemical characteristics onal alterations (such as photodegradation, hydrolysis and revolatilization). In contrasts, the biodegradation of were determined by measuring anions, cations, organic acids, carbon and contaminants in snow melt water. organic contaminants, by supraglacial bacteria has been neglected so far. Then, we assessed a surrogate level of competition within these communities by following changes in antibiotic resistance gene determinant (ARGD) abundance. We built co-occurrence networks of gene expression for Method: We investigated biodegradative processes by microcosm experiments simulating a cryoconite hole the 16S rRNA gene based taxonomy, and metagenomic and metatranscriptomic profiles to evaluate possible system conducted in situ to on the Forni glacies (Italian Alps), which is exposed to the organophosphorus interactions between the environmental parameters tracked during this study and biological indicators. insecticide chlorpyrifos (CPF), a xenobiotic tracer that accumulates on glaciers after atmospheric medium- and long-range transport. Results / Discussion: We observed a significant difference between the ES and LS samples in terms of chemistry, functional profiles and gene expression in addition to changes in bacterial co-occurrence networks. These Results / Discussion: Biodegradation was the most efficient process contributing to the removal of CPF on results suggest that bacterial interactions are dynamic across environmental gradients and their network glacier surface. The high concentrations of CPF detected in cryoconite holes and its estimated half-life (35–69 densities fluctuate as a function of microbial community activity. days) indicated that biodegradation can significantly reduce CPF transported on glaciers and contrast its release to downstream ecosystems. Results also showed that cryoconite concentrated CPF at high levels (2-3 Conclusion: This study is the first, to our knowledge, to explore dynamic changes of bacterial interactions as mg/kg). well as the possible coupling of biogeochemical processes by bacterial communities in polar snow environments. Metagenomic data of natural cryoconite from Forni glacies allowed reconstructing and annotating 65 partial genomes. Searching for genes involved in CPF biodegradation allowed identifying the reconstructed genome “bin 6”, one of the most abundant in the metagenome, as potentially involved in CPF biodegradation. Bin 6, which is phylogenetically related to Burkholderiales, also harbored pufML genes, which code for photosynthetic reaction center L and M subunits and were used as marker genes for the detection of aerobic anoxy- genic phototrophs (AAPs). AAPs are obligate aerobic bacteria, which use light to supplement their metabolic demands and organic molecules as carbon source. These evidences suggest that AAPs might be involved in CPF biodegradation.

Conclusion: The metabolic versatility of cryoconite bacteria suggests that these habitats might contribute to the degradation of a wide class of pollutants with different physical–chemical properties. Cryoconite therefore acts as a “biofilter” for organic pollutants on glaciers. The contribution of cryoconite to the removal of organic pollutants should therefore be included in the models predicting the environmental fate of these compounds in cold areas.

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[13] BIOGEOGRAPHY OF CRYOCONITE BACERIAL COMMUNITIES ON GLACIERS OF THE TIBETAN [14] METABOLICALLY ACTIVE, RARE BACTERIAL TAXA UNDERPIN COMMUNITY STABILITY ON PLATEAU THE GREENLAND ICE SHEET

Yongqin Liu1, Vick-Majors Trista2, Priscu John3, Yao Tandong4 Jarishma Gokul1, Karen Cameron2, Matt Hegarty3, Tristram D. L. Irvine-Fynn4, Joseph Cook5, Luis Mur6, Arwyn Edwards1 1 Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China 2 Université du Québec À Montréal, Canada 1 Institute of Biological, Rural and Environmental Sciences, Cledwyn Building, Aberystwyth University, United Kingdom 3 4. Department of Land Resources and Environmental Sciences, Montana State University, United States 2 Institute of Biological, Rural and Environmental Sciences, New Ibers Building, Aberystwyth University, United Kingdom 4 Institute of Tibetan Plateau Research, Chinese Academy of Sciences, China 3 Institute of Biological, Rural and Environmental Sciences, Phenomics Centre, Aberystwyth University, United Kingdom 4 Institute of Geography and Earth Sciences, Llandinam Building, Aberystwyth University, United Kingdom Aim: Cryoconite material decreases surface albedo and accelerates glacier mass loss, a problem of particular 5 Department of Geography, University of Sheffield, United Kingdom importance in the rapidly melting Tibetan Plateau. No studies have addressed the microbial community com- 6 Institute of Biological, Rural and Environmental Sciences, Edward Llwyd Building, Aberystwyth University, United Kingdom position of cryoconite holes and their associated ecosystem processes on Tibetan glaciers. To further enhance our understanding of these glacial ecosystems on the Tibetan Plateau and to examine how geographic distan- Aim: The surface of the Greenland Ice Sheet is a biologically active locale supporting many diverse microbial ce and glacier environmental variable drive distribution pattern of cryoconite bacterial communities at 1000 taxa. Bacterial communities across the ice sheet are spatially variable and significantly influenced by bioge- km regional scale glaciers on the Tibetan Plateau, we explored the bacterial communities within cryoconite ography and biogeochemistry. In summer, the ice surface reveals extensive cryoconite hole coverage that is holes associated with three climatically distinct Tibetan Plateau glaciers. directly correlated to surface albedo, melt rate, mass balance and biological activity. However, the relative importance of temporal changes on bacterial community composition and activity in these supraglacial niches Method: Illumina sequencing of the V4 region of the 16S rRNA gene have yet to be determined. To enhance this knowledge, community dynamics of bacteria in cryoconite, snow and meltwater streams were investigated. Results / Discussion: Cryoconite bacterial communities were dominated by Cyanobacteria, Chloroflexi, Betaproteobacteria , Bacteroidetes and Actinobacteria. The relative abundances of theCyanobacteria , Method: A localised area of the Greenland Ice Sheet within the ablation zone of its south-western margin, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria were significantly correlated with the latitude, weather station S6 on the Kangerlussuaq transect, was studied for seven weeks during the 2014 Arctic sum- longitude, TOC, TN, and S concentrations. The NMDS ordination analysis clearly revealed differences in the mer. Illumina MiSeq high throughput sequencing was successfully performed on libraries generated from 16S cryoconite bacterial communities among the three glaciers. Analysis of similarity demonstrated that the rRNA genes (total 16S DNA) and cDNA from 16S rRNA (active 16S DNA) alongside negative controls. These glacier was an important determinant of community composition. A distance decay of similarity model and were interpreted as markers of relative abundance within the total community and taxon-specific protein mantel tests indicated the geographic distance effect on the cryoconite bacterial β-diversity. The complete synthesis potential (PSP), respectively. set of geographic distance and cryoconite environmental variables (TOC, altitude, and conductivity) explained 61.91% of the variation in the bacterial communities. The geographic distance alone explained 8.81% of the Results / Discussion: The investigation revealed communities within the supraglacial habitats are influen- variations, and the cryoconite environmental variables explained 9.45%. The interactions between environ- ced by rare active taxa that contribute disproportionately to protein synthesis potential and are temporally mental variables and geographic distance explained 43.53% of the variation, indicating that the geographic variable despite their low observed abundance. Cryoconite and its hydrologically linked habitats are largely distance and environmental variables were strongly dependent on each other. Both cryoconite environmental colonised by OTUs associated with the filamentous cyanobacterial taxon Phormidesmis priestleyi, providing variables and geographic distance were important factors shaping bacterial community composition. stable community diversity during periods of high incident radiation and albedo in the boreal summer in addition to primary production in ice surface microhabitats. The increase in protein synthesis potential of these Conclusion: Cryoconite bacterial community composition varied according to their geographical locations, freeze thaw-tolerant cyanobacteria early in the summer season is typical as they are known to swiftly adapt exhibiting significant differences among glaciers studied on the Tibetan Plateau. Regional beta diversity was to favourable environmental conditions. Stream and snow habitats have a more diverse distribution of high driven by the interaction between geographic distance and environmental variables, the latter of which contri- protein synthesis potential taxa over the duration of the summer months, and are dominated by a member buted more than geographic distance to the variation in cryoconite microbial communities. of the Alphaproteobacteria species Methylobacterium during early summer, which changes to Granulicella aggregans and Spartobacterium (Acidobacteria) in snow and stream communities respectively towards late summer. Lack of mechanical stability incurred from physical displacement during seasonal glacial melt, runoff and wind perturbation renders them susceptible to immediate changes in community structure and function, causing high fluctuation in the rare biosphere. Peaks in activity of the abundantAlphaproteobacteria OTUs and rarer Acidobacteria, Bacteroidetes, Betaproteobacteria, Verrucomicrobia and candidate phyla at various periods during the Arctic summer also implies that biotic controls may dynamically affect microbial growth and/or cellular reproduction rates. Members of these phyla have been identified as key potentially active members of the GrIS surface, strategically evolved to survive and dominate in extreme environmental conditions due to their ability to degrade and uptake biopolymers Bacteroidetes( ) and monomers (Alphapro- teobacteria) as carbon and energy sources in marine ecosystems. In addition, these phyla act as mediators of biological control (Cytophaga) for the biosynthesis of lipids and fatty acids, for carbohydrate metabolism, nitrate reduction, EPS production, environmental signalling, signal transduction, and DNA mobilisation.

Conclusion: Overall, the heterotrophic bacteria on the surface of the Greenland ice sheet show distinct transient behaviour as taxa appear selective to their physical environment and biogeochemical state in the cryosphere, with integral associations with photoautotrophicCyanobacteria known to contribute to the formation of a robust microhabitat conglomerated with humics, polymers and minerals that are essential to the maintenance of a diverse and productive cryoconite community. The rare biosphere provides a source for bacterial recruitment in cryoconite, snow and stream habitats. These taxa may be the key players responsible for the observed seasonal shifts of PSP in favourable conditions, while generating the essential nutrient reserves required during winter dormancy periods. 25 Oral Abstracts Oral Abstracts

[15] ECOLOGICAL MODELLING OF THE GREENLAND ICE SHEET SURFACE ECOSYSTEM [16] STRUCTURAL AND FUNCTIONAL CHARACTERIZATION OF THE SOIL MICROBIOME ALONG A GLACIER FOREFIELD CHRONOSEQUENCE INCLUDING SOURCES OF COLONIZERS M. Stibal¹, J. A. Bradley², J. E. Box³ Johanna Donhauser1, Arwyn Edwards2, Thomas Rime1, Beat Frey1 1Department of Ecology, Faculty of Science, Charles University, Prague, Czechia Forest Soils and Biogeochemistry, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland1 2Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA Institute of Biological, Rural and Environmental Sciences, Cledwyn Building, Aberystwyth University2, Aberystwyth, UK 3Department of Glaciology and Climate, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark

Aim: Climate change has led to substantial retreat of both Alpine and Arctic glaciers exposing large areas The Greenland ice sheet (GrIS) is the largest supraglacial (glacier surface) ecosystem on Earth due to its high of barren bedrock. Exposed rock material is rapidly colonized by microorganisms and subject to weathering surface melting. The GrIS supraglacial ecosystem is changing rapidly due to climate warming, causing retreat processes giving rise to soil formation. As glaciers retreat over time, soil development takes place in a suc- of the margins of the ice sheet and an inward expansion of the biologically active ablation area, with poten- cessional manner on the deglaciated area. Here, we assess the microbial community structure and diversity tially significant impacts on the Arctic. in different stages of soil development and between soil depths. Moreover, we identify microbial functions associated with each stage of soil development. As microbes play a crucial role as pioneer organisms in the in Microorganisms in supraglacial ecosystems cycle carbon and nutrients and may also affect the physical early stages of soil development, in addition, we elucidate sources and identities of microbial colonizers. behaviour of glaciers by increasing melt via lowering the surface reflectivity of ice. Moreover, supraglacial ecosystems may significantly impact downstream terrestrial and marine ecosystems via meltwater export of Method: Bacterial and fungal diversity was assessed in four distinct stages of soil development (10, 60, 80, live cells and nutrients. 110 years) ranging from barren to densely vegetated soil and at two depths (surface, 5 cm, 20 cm depth) in the forefield of Damma glacier, Switzerland, using Illumina amplicon sequencing of ribosomal markers. Insights into the supraglacial ecosystem have been driven mostly by empirical approaches relying on field In addition, microbial diversity in endogenous glacier habitats (ice, sub-, supraglacial sediments and glacier sampling and laboratory measurements. However, these are often constrained by patchy spatial and temporal stream leaving the glacier forefront) and exogenous sources (atmospheric deposition: snow, rain and aeolian coverage, limiting their appropriateness for upscaling. Mathematical models are ideally suited to studying the dust) were compared with those occurring in recently deglaciated barren soils before and after snow melt in supraglacial ecosystem of the GrIS since they can disentangle and quantify the interplay of various biogeo- order to identify sources of microbial colonizers. Moreover, we applied shotgun metagenomics to elucidate chemical and physical processes, bridge the vast spatial scale of the ice sheet, make scenario-based predicti- microbial functions related to different stages of soil development along the chronosequence. ons, identify gaps in the current understanding and thus help design future sampling and laboratory analyses. Despite increasing data on sources, sinks, and transformations of carbon and nutrients in the GrIS supraglacial Results / Discussion: Bacterial and fungal community structures differed among stages of soil development ecosystem, few attempts of linking them together into an ecosystem model have been made to date. As a re- and depths shifting along with changes in soil chemical properties and increasing vegetation cover. Soil sult, estimates of microbial activity and associated carbon and nutrient transformations on an ice sheet scale depth influenced bacterial and fungal communities in barren and sparsely vegetated soils, whereas vegeta- are highly uncertain, and predictions of future ecosystem change are virtually impossible. ted soils did not differ between soil depths. Endogenous glacier habitats were identified as most probable sources of microbial colonizers in newly developing soils. Atmospheric bacteria and fungi were dominated by Here we provide a theoretical framework of the supraglacial ecosystem of the GrIS to facilitate ecological plant-epiphytic microorganisms and differed from endogenous glacier habitats and barren soils indicating that modelling as a tool for understanding present day and future ecosystem dynamics. To do so, we review the atmospheric input of microorganisms is not a major source of microbial pioneers in newly formed soils. We supraglacial ecosystem of the GrIS and present three conceptual models of the GrIS microbial ecosystem. found, however, that bacterial communities in newly exposed soils resembled those of endogenous habitats, These models focus on organic carbon transformations but differ in complexity by the detail that biological which suggests that bacterial pioneers originating from sub- and supraglacial sediments contributed to the processes are represented. We assess the strengths and weaknesses of each modelling approach, their role colonization of newly exposed soils. in improving the understanding of carbon cycling and ecosystem dynamics, and the necessary integration of these modelling approaches with field data to parameterise and validate numerical output. In addition, application of shotgun metagenomics will give insights into microbial processes related to important ecosystem functions such as major biogeochemical cycles developing along the chronosequence.

Conclusion: The disintegration of the cryosphere in response to global warming will lead to exposure of bedrock at large scale areas in the future imposing a need to enhance our understanding of ecological processes in these newly developing ecosystems. This study provides important information on how microorganisms contribute to the formation of soil ecosystems in deglaciated areas revealing changes of microbial diversity and function along the chronosequence and identifying sources of microbial colonizers.

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[17] CHARACTERISATION OF YEAST AND FILAMENTOUS FUNGI OF ARCTIC CRYOCONITES [18] SNOW ALGAE INCREASE MELT ON THE HARDING ICEFIELD

PURNIMA SINGH1, UTPAL ROY1 Gerard Ganey1, Roman Dial1, Michael Loso2, Anne Burgess3 1 Birla Institute of Technology and Science (Bits), Pilani-K.K. Birla Goa Campus, , Goa, India 1 Alaska Pacific University, Anchorage, United States 2 National Park Service, Wrangell St. Elias National Park and Reserve Aim: Characterisation of yeast and filamentous fungi of Arctic Cryoconites 3 Earth Science Information Partners, Boulder, Co, United States Method: Sampling of cryoconites, Phenotypic characterization of the yeasts and filamentous fungi, Screening for enzymatic activities, DNA extraction, Polymerase chain reaction (pcr) and sequencing, Sequence align- Aim: Snow algae are an important microbial component of glaciers in Alaska where they inhabit the equili- ment and Phylogenetic analysis brium line altitude (ELA) between the zone of accumulation and ablation. The ELA roughly marks the snow line where low-albedo bare ice contributes substantially more meltwater than high-albedo snow. Because of Results / Discussion: This abstract presents results on culturable cryophilic yeasts and filamentous fungi the high albedo of snow-covered glaciers and ice sheets, the presence of algae reduces albedo and increases isolated from cryoconite holes at Austre Brøggerbreen, Vestre Brøggerbreen and Midre Lovenbreen gla- melt. Like all organisms, snow algae require liquid water and nutrients for growth and reproduction. This study ciers, Svalbard. Based on DNA sequence data, these were identified asCryptococcus gilvescens, Mrakia presents data collected from three glaciers in Alaska and provides experimental evidence that snow algae sp., Rhodotorula sp., Thelebolus sp., and Articulospora tetracladiaand Phialophora alba. Amongst these, increase snowmelt. Articulospora tetracladia is a novel species. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activity were carried out indicating varying amounts of enzyme production at different Method: Standard variables for mass balance on glaciers and interval photography were collected on the temperatures. Filamentous fungus Articulosporasp. Cry-FB1 and Cry-FB2, expressed high amylase, cellulase, Eklutna Glacier. On the Harding Icefield we established 21 experimental blocks in a 0.5 km^2 area with four lipase and protease activities while yeastRhodotorula sp. Cry-FB3 showed high amylase and cellulase activity. treatments per bock (bleach, fertilizer, water, and control) and measured melt from May through August on Thelebolus sp. Cry-YB240 and Cry-YB241 showed protease and urease activities.Mrakia sp. showed phosphate the Harding Icefield. In addition, we sampled snow algae to determine if our experimental treatments effecti- solubilization between 4 and 15oC. The effects of temperature, and salt on the growth of the cultures were vely manipulated algae abundance. Using a spectrometer, cell area, and Landsat 8 satellite imagery we built a studied. Optimum temperature of growth was on 10ºC at pH 7.0. The extracellular and intracellular filtrate of spatial model of the contribution of algal surface area to meltwater across the Harding Icefield. the cultures showed positive antifreeze protein (AFP) activity. Chemical analysis of cryoconites revealed the presence of organic carbon, Nitrogen, phosphorus and several elements in substantial amounts. Filamentous Results / Discussion: The temporal correspondence of red snow, melt-predictors, and melt-rate are consi- fungi and yeast in the cryoconite holes possibly drive the process of organic macromolecule degradation stent with red snow algae as both cause and effect of snowmelt. We found that there was no difference in through cold-adapted enzyme secretion, thereby assisting in nutrient cycling in these supraglacial environ- melt among treatments from May — July when algae were not visible on the surface of the snow, but that ments. Further, these cryophilic fungi, due to their enzyme producing ability, may provide an opportunity for during the month of July when algae bloomed that the fertilizer treatments had both significantly more melt biotechnological research in the Arctic. and more algae than controls. Similarly bleach plots had significantly less melt and less algae than controls. Manipulated alga abundance explained 34% of variability in snowmelt. While NPK addition increased alga Conclusion: The present study was focused on characterizing the fungal communities present in the glacier cell counts nearly four-fold, similar to NP-enriched lakes, water alone increased counts 50%. By August snow cryoconites of Svalbard, Arctic. The isolates also show varied responses to enzyme producing ability, demon- in the study area had melted to ice and there were no significant differences among treatment types in melt strates their biotechnological potential. High amylase, lipase and protease activities expressed by most of -iso rate. Because red snow communities are reliably detectable through remote sensing, estimates of microbial lates provide a clue to the potential applications of cryoconites fungi. The detailed studies of these cold active impacts, such as contribution to discharge, are feasible. Using Landsat-8 imagery calibrated by a normalized enzymes needs carried out in future for the prospect of its application in Agriculture and industries. difference index for alga abundance, we estimated snow-algae’s contribution to snowmelt across a 2,000 square-kilometer Harding icefield.

Conclusion: These results show experimentally that snow algae are nutrient limited and increase snowmelt. Remote sensing can be used to detect areas of red snow. The melt effect of algae can be modeled on large-scale areas such as Greenland.

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[19] MICROBIAL FUNCTIONAL DIVERSITY AND RESILIENCE IN POLAR ECOSYSTEMS [20] PROKARYOTIC COMMUNITY STRUCTURES ALONG SALINITY GRADIENTS OF MELT PONDS ON SEA-ICE FLOES IN THE CHUKCHI SEA David Pearce1, Maria Luisa Avila Jimenez2 1 2 2 2 1 University of Northumbria at Newcastle, Newcastle Upon Tyne, United Kingdom Gwangil Jang , Eun Jin Yang , Sung‐Ho Kang , Chung Yeon Hwang 2 Na (Consultant), United Kingdom 1 Korea Polar Research Institute, Incheon, Korea, Rep. of South 2 Korea Polar Research Institute, Korea, Rep. of South Aim: Functional diversity reflects the variety of biological processes performed within an ecosystem [1]. Fun- ctionally diverse ecosystems are considered resilient to change[2]; however, ecosystem resilience estimates Sea-ice floes in the Arctic Ocean are extreme environments with variable nutrients, light availability and sali- based on biological diversity implicitly assume that functionality is somewhat homogeneously distributed nity. Melt ponds are formed on sea-ice in summer by thawing of surface ice and melting snow. Recently, melt across species. Here, we aimed to understand how microbiological networks organize at the functional level pond areas have increased in Arctic summer. In the present study, we had questions (1) who “seed prokaryo- to address this question. tes” (Bacteria and Archaea) are in fresh melt ponds in an early stage of development, (2) how they change in community compositions with development of melt ponds, and (3) which environmental factors drive Method: We use weighted gene co-expression network analyses (WGCNA), K-means++ cluster analysis and the change of prokaryotic communities. To answer the questions, prokaryotic community structures were association algorithms to analyze the diversity patterns of over 20.000 functional genes in a Geo-chip microar- investigated using pyrosequencing of 16S rRNA gene for 27 melt ponds (salinity of 0.2-26.8) on 2 sea-ice floes ray, developed from samples from 10 locations from the Arctic and the Southern oceans. along with ambient seawater in the Chukcki Sea in August, 2014. Eleven and two phyla belonging to Bacteria and Archaea, respectively, were identified in melt ponds. The “seed prokaryotes” in melt ponds (salinity of Results / Discussion: The genes analyzed arrange in a modular Erdős–Rényi (ER) random network composed 0.2-5) were predominantly comprised of Bacteroidetes (44-90%). A drastic change of prokaryotic community of 21 independent modules. A similar pattern was obtained from the K++ means analysis. The level of hete- structures was observed along the salinity gradient of melt ponds. In the presentation, results will be shown in rogeneity within modules is low, with most nodes presenting an equally high level of connectivity. Within the detail and discussed. modules, different functions also organize following ER random networks. As opposed to any other biological network studied to date, microbial communities do not appear to organize as scale-free networks. The results to this point suggest that microbial networks are highly unstable; however, the functions also distribute homogeneously across geographical locations. At the phylogenetic level, only three distinct networks are found within the genes included in the microarray, suggesting that the functional units found do not correspond to species or taxonomic units.

Conclusion: Our analyses show no evidence of recent environmental impact on Polar marine microbial communities at the functional level, unless all communities analyzed have changed exactly in the same direction and intensity, which is unlikely as we are comparing areas changing at different paces. Therefore, even if microbial communities are fast changing in these regions due to climate warming, the change is as yet not obvious at the functional level. Furthermore, the pattern we see here is not what could be expected from a genetic erosion scenario, as all sites include tightly packed complex networks of essential genes and a series of smaller, but well-structured and homogeneously present, clusters of less frequent genes. Genetic erosion will not only be expected to homogenise the landscape, but to reduce functional diversity throughout. The scenario we see here is that of diverse functionally redundant clusters homogeneously distributed across Polar Ocean surface waters; therefore, this pattern is more likely to reflect the very nature of functional distribution in microbial communities than a consequence of genetic erosion.

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[21] GLACIAL CONTROLS ON MICROBIAL COMPETITION AND BIOGEOCHEMICAL CYCLES IN [22] MULTIPLE ORIGINS AND ADAPTIVE STRATEGIES OF DIATOMS IN THE MELTWATER STREAMS ARCTIC FJORDS OF THE MCMURDO DRY VALLEYS, ANTARCTICA

Alexander Michaud1, Katja Laufer1, Hans Røy1, Bo Barker Jørgensen1 Angela Zoumplis1, Andrew Allen1 1 Center for Geomicrobiology, Department of Bioscience, Aarhus University, Aarhus, Denmark 1 Scripps Institution of Oceanography, San Diego, United States

Aim: Arctic fjords are a biogeochemically-active interface between terrestrial subglacial processes and the Aim: During the early Pliocene, warm average global temperatures and a rising sea level produced substantial marine shelf environment. The supply of iron from the fjord to the Arctic shelf environment is dependent on flooding within the Antarctic Dry Valleys network that persisted for millions of years. The current warming the microbial reactions that catalyze metal transformations in the fjord sediment. Iron and sulfate reducti- trend has resulted in increased glacial meltwater flood pulse events and aeolian transport of coastal evapo- on are quantitatively the most important organic carbon mineralization pathways in marine sediments. The rates, which in turn are predicted to enhance microbiota connectivity. The paleohistory of the Dry Valleys balance or competition between iron and sulfate reduction is driven by thermodynamic favorability, the combined with intensified dispersal mechanisms make it likely that some diatoms in this landscape are marine presence of terminal electron acceptors, and supply of electron donors. Iron reduction yields higher free in origin and have evolved distinct ecophysiological properties energy than sulfate reduction when reactive, poorly crystalline Fe(III)-oxides are present. Thus, the delivery of reactive metal oxides from glacial runoff may influence the distribution of terminal oxidation processes. The Method: Samples were collected from Ross Sea ice cores and meltwater stream algal mats in the lower three investigated fjords of western Spitsbergen, Svalbard differ in their bedrock lithologies, glacial catchment Garwood and Miers valleys (sea level), Taylor Valley (20m-100m), Wright Valley (180m-600m) and Victoria Val- area and quantity of glacially-derived, clastic material delivery; therefore, they represent a natural laboratory ley (400m-900m). Diatom community samples from these distinct marine and freshwater environments were to address the hypothesis that glacial discharge quantity and composition impacts microbial competition and processed for RNA extraction and sequencing. An 18S rRNA gene phylogenetic analysis generated enough biogeochemical cycling in permanently cold marine sediments. signal to assess evolutionary relationships and transcript profiles were compared.

Method: We determined the porewater geochemistry from 1 m sediment cores from three contrasting fjords Results / Discussion: RAxML Maximum Likelihood and Bayesian trees display the formation of monophyletic along the west coast of Spitsbergen, Svalbard. We quantified the concentration of dissolved Fe2+, Mn2+, dis- Dry Valleys, Ross Sea and global marine diatom clades with significant bootstrap/posterior probability support. 2- + The trees also provide evidence for freshwater colonization events of multiple taxa of diatoms stemming from solved inorganic carbon (DIC), SO4 , NH4 in sediment porewater and determined the rate of bacterial sulfate reduction. To complement the porewater geochemistry measurements, we set up long-term, anoxic bag incu- marine ancestors. Comparative transcriptome profiles of both marine and meltwater diatom communities bations and amended these bags with excess poorly-crystalline Fe-oxide (ferrihydrite), molybdate (to inhibit identified similarities in function but also evolution of distinct adaptive strategies. sulfate reduction) or organic carbon. We monitored these bags for total organic carbon mineralization (volatile + 2+ 2+ Conclusion: These results suggest the possibility of multiple origins of Dry Valley diatoms and bring insight to fatty acids, DIC and NH4 ), iron reduction (Fe , sequential Fe extractions), manganese reduction (Mn ) and 35 2- the divergence of diatom taxa. With the predicted amplification of dispersal mechanisms, this baseline data sulfate reduction ( S-SO4 reduction rates). on diatom distribution patterns will ultimately be utilized in determining increased connectivity among valley Results / Discussion: Areal sulfate reduction rates increased with increasing distance from the terminus of landscapes. the glacier at the head of the fjord. This trend may be due to increased organic carbon input to outer fjord stations or greater delivery of poorly crystalline metal oxides near the glacier terminus. Our bag incubations show that sulfate reduction increases in the presence of organic carbon addition, while sulfate reduction is suppressed in non-sulfidic sediment after the addition of ferrihydrite. In the fjord with high organic carbon content and free sulfide, the addition of ferrihydrite only partially inhibited sulfate reduction.

Conclusion: We show that increased delivery of organic carbon and Fe(III) minerals to fjord sediments impact the balance between iron and sulfate reduction as the dominant carbon oxidation pathway. Glacial retreat and sea ice loss will change the delivery of electron donors and acceptors to fjord sediments and impact carbon mineralization pathways and the flux of metals to the Arctic shelf environment.

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[23] COMPARATIVE GENOMICS OF THE POLYEXTREMOTOLERANT BLACK YEAST [24] MICROBIAL EXOPOLYSACCHARIDES FROM THE COLD-ADAPTED PSYCHROBACTER ARCTICUS AUREOBASIDIUM PULLULANS 273-4

Cene Gostinčar1, Martina Turk1, Janja Zajc1, Nina Gunde-Cimerman1 Maria Michela Corsaro1, Angela Casillo1, Marcello Ziaco1, Maria Luisa Tutino1, Ermenegilda Parrilli1, Matthew Gibson2, Daniel Mitchell2 1 Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia 1 Federico II University of Naples , Department of Chemical Sciences, Naples, Italy Aureobasidium pullulans is a black yeast of considerable interest due to its ubiquitous distribution, polyextre- 2 University of Warwick, United Kingdom motolerant physiology and great biotechnological potential. It is best known as an epiphyte species, inhabiting various plant surfaces, but it is also frequently found in certain types of glacial ice, in domestic environments Aim: Cold-adaptation is currently studied at various molecular levels, including genetics,1 metagenomics,2 and in food, in coastal ponds of hypersaline water and a number of other peculiar habitats. It is used for the and proteomics.3 Unsaturated fatty acids, cold shock proteins, anti-freeze proteins, ice-nucleating proteins, production of pullulan and aureobasidin A and is commercially available as a biocontrol agent used in agricul- and exopolysaccharides (EPS) contribute in different ways to cope with low temperature constraints.4 EPS ture to limit the damage caused by several plant pathogens (both bacterial and fungal). In 2014 we published produced by both psychrophilic and psychrotolerant bacteria are thought to function as cryoprotectans and/ a de novo genome sequence of A. pullulans and three closely related species, revealing a redundancy in se- or to constitute an essential component of biofilm. Microorganisms colonizing permanently cold environ- veral gene families that could be linked to the nutritional versatility of these species and their particular stress ments, such as sea-ice and permafrost, are reported to produce a large amount of both capsular and medium tolerance. Now we are resequencing other A. pullulans strains from our collection, which includes a large released polysaccharides.4 number of isolates from glacial ice. Our aim is to investigate the genomic signatures behind the extraordinary adaptability of this species to different environments. These efforts should also open new possibilities for the In the last years, our team has been involved in an in-depth study of carbohydrate polymers structural charac- biotechnological exploitation ofA. pullulans. Results of the comparative genomics will be presented with a terization from cold-adapted microorganisms,5-7 to give insight into their ecological role. Our main goal was to special focus on identification of differences between the glacial strains and isolates from temperate regions find relationships between the structure and the antifreeze activity of these macromolecules. (e.g. isolates from plant surfaces, fresh water and domestic environments). In this communication, I will illustrate our results about the characterization and the antifreeze activity of Gostinčar, Cene; Ohm, Robin A; Kogej, Tina; Sonjak, Silva; Turk, Martina; Zajc, Janja; Zalar, Polona; Grube, both capsular and medium released polysaccharides isolated from Psychrobacter arcticus 273-4, a permafrost Martin; Sun, Hui; Han, James; Sharma, Aditi; Chiniquy, Jennifer; Ngan, Chew Yee; Lipzen, Anna; Barry, Kerrie; isolate. Grigoriev, Igor V; Gunde-Cimerman, Nina (2014). Genome sequencing of four Aureobasidium pullulans varie- ties: biotechnological potential, stress tolerance, and description of new species. BMC Genomics. 15 (1): 549. Method: Bacteria cells were grown in Luria-Bertani broth at 4°C in aerobic condition. The capsular polysaccha- doi:10.1186/1471-2164-15-549. PMID 24984952. ride was extracted from dried cells by phenol/water method, while the extracellular polysaccharide was purified from the medium by gel-filtration chromatography. Both polymers were characterized by chemical analysis and NMR spectroscopy. Ice recrystallization inhibition activity was measured using a modified splat assay.

Results / Discussion: Dried cells were extracted by hot phenol/water method as reported.5 The water extract was analyzed by DOC-PAGE electrophoresis, and the alcian blue staining showed the presence of high molecular masses anionic polysaccharide, while the silver staining indicated the lipooligosaccharide,8 too. After acetic acid hydrolysis and a gel-filtration column, the chemical analysis indicated, for the first eluted peak, glucose as the only component; in contrast, NMR data revealed another monosaccharide with a carboxyl group. When the extracellular medium was considered, the chemical analysis indicated mannose as the most abundant monosaccharide for the purified polysaccharide. The two polysaccharides were extensively studied by two-dimensional NMR spectroscopy, revealing two completely different structures. Preliminary IRI assays indicated an interesting activity for the mannan polysaccharide.

Conclusion: In this study, the extracellular carbohydrate polymers isolated from the cold-adapted Psychrobacter arcticus 273-4 have been characterized. The production of both capsular and extracellular polysaccharides resembles the cold-adaptation strategy already found for Colwellia psychrerythraea 34H, a sea-ice living bacterium.

References

[1] P. De Maayer, D. Anderson, C. Cary, D. A Cowan, EMBO Reports 2014, 15, 508-517. [2] M. Baweja, L. Nain, Y. Kawarabayasi, P. Shukla, Front. Microbiol. 2016, 7, 965. [3] T. J. Williams, F.M. Lauro, H. Ertan, D.W. Burg, A. Poljak, M.J. Raftery, R. Cavicchioli,Environ. Microbiol. 2011, 13, 2186-2203. [4] J.W. Deming In Encyclopedia of Microbiology; Shaechter, M., Ed.; Elsevier: Oxford, UK, 2009; 147-158. [5] S. Carillo, A. Casillo, G. Pieretti, E. Parrilli, F. Sannino, M. Bayer-Giraldi, S. Cosconati, E. Novellino, M. Ewert, J.W. Deming, R. -Lan zetta, G. Marino, M. Parrilli, A. Randazzo, M.L. Tutino, M.M. Corsaro,J. Am. Chem. Soc. 2015, 137, 179-189. [6] A. Casillo, E. Parrilli, F. Sannino, D.E. Mitchell, M.I. Gibson, G. Marino, R. Lanzetta, M. Parrilli, S. Cosconati, E. Novellino, A. Randaz- zo, M.L. Tutino, M.M. Corsaro,Carbohyd. Pol. 2017, 156, 364–371. [7] A. Casillo, J. Ståhle, E. Parrilli, F. Sannino, D. E. Mitchell, G. Pieretti, M. I. Gibson, G. Marino, R. Lanzetta, M. Parrilli, G. Widmalm, M. L. Tutino, M. M. Corsaro Anton. Leeuw. Int. J. G., 2017, DOI 10.1007/s10482-017-0834-6. [8] A. Casillo, E. Parrilli, S. Filomena, B. Lindner, R. Lanzetta, M. Parrilli, M.L. Tutino, M.M. Corsaro Mar. Drugs 2015, 13, 4539-4555. 35 Oral Abstracts Oral Abstracts

[25] WHAT COLOR SHOULD SNOW ALGAE BE? [26] INVESTIGATION OF COLD ADAPTATION IN ARCTIC PERMAFROST BACTERIA THROUGH COMPARATIVE GENOME AND AMINO ACID ANALYSES. Roman Dial1, Gerard Ganey1, S. McKenzie Skiles2 1 2 2 2 2 1 Alaska Pacific University, Anchorage, United States Isabelle Raymond , Jacqueline Goordial , Yevgen Zolotarov , Jennifer Ronholm , Martina Stromvik , Corien 3 1 2 Department of Earth Science, Utah Valley University, United States Bakermans , Lyle Whyte 1 Mcgill University - Macdonald Campus, Ste-Anne-de-Bellevue, Canada 2 Mcgill University - Macdonald Campus Aim: Recent theoretical and experimental studies show an important role for red snow algae in glacial melt 3 The Pennsylvania State University, Altoona, United States because red snow algae measurably reduce snow surface albedo. However, a direct role of secondary caro- tenoids, primarily astaxanthin, in the melting of ice and snow crystals has not yet been explored. The snow- Aim: Permafrost accounts for 26% of all soil ecosystems on earth and is home to diverse and unique microbial pack surface environment is often both frozen and well-drained, suggesting it is liquid-water limited. Organis- communities. Our understanding of microbial life in these environments, their growth, activities, and adap- ms situated on the snow surface during daylight are subject to both strong irradiation and drought conditions, tations, remains limited. We aim to increase our understanding of cold adaptation and growth in permafrost often near freezing temperatures. Astaxanthin is known to shield photosynthetic apparatus in the snow alga subzero growing (cryophilic) bacteria. With new genome sequences from Arctic permafrost cryophiles, we in- cell. We wished to investigate the hypothesis that the astaxanthin itself plays an active role melting proximal vestigated 1) genome-wide features of cold adaptation present in permafrost cryophilic bacteria; 2) the extent ice and snow crystals both by heat dissipated during photo-protection and through florescence of visible light of amino acid adaptations, imparting greater protein flexibility at cold temperatures, across several genera of at wavelength that are absorbed by snow. permafrost bacteria; 3) potentially conserved or important adaptive traits present in cryophiles.

Method: We used solar irradiance at the earth surface and the absorption spectra of snow across optical Method: As part of a Joint Genome Institute (JGI) Community Sequencing Project, 5 Arctic subzero growing grain sizes to model the expected value of solar power density absorbed by snow as a function of wavelength. strains were sequenced, an Actinotalea sp., Methylobacterium sp., Kocuria sp., Polaromonas sp., and Pae- We then compared these wavelengths of peak power density to published fluorescent wavelengths for resting nisporosarcina sp. Genome sequencing and annotation was performed by JGI. Analysis of the genomes was red cells of the algae Haematococcus pluvialis, a commercial source of astaxanthin, that served as a model for carried out using in-house python scripts, bioinformatics programs, and JGI online database tools. Characteri- red snow alga cells. We also performed a simple experiment where we deposited powdered pigments of blue, stics of cold adaptation, such as presence/absence of genes known to be important for cold growth, genomic red, and black on snow surface and qualitatively observed the melt results. redundancy, and differences in protein flexibility, as evidenced by amino acid modifications (fewer salt bridges and proline residues, increased serine and glycine content, less hydrogen bonds and hydrophobicity, and a reduced Arg/Lys ratio), was investigated in the cryophiles through comparative analyses with known mesophi- Results / Discussion: The global maximum solar power absorption by snow occurred in the near infrared at lic relatives. about 1000 nm. There were four local maxima at wavelengths less than 1000 nm, which varied only slightly by optical grain size. For large grain snow (1 mm), for instance, a possible late summer, peak melt size, we Results / Discussion: The cryophiles possess many genes typically associated with cold adaptation includ- identified solar power density peaks at 870, 795, 745, and 665 nm. If the power density maximum at ~1000 ing cold shock proteins, RNA helicases, osmotic and oxidative stress, carotenoid synthesis, and cell wall and nm is scaled to one, then the scaled power density values were about 0.6 at 795 nm, 0.5 at 745 nm, and 0.4 membrane modifications. Most cryophiles have higher transposase copy numbers then their respective at 665 nm. These three wavelengths are either within or slightly longer than visible red spectrum. Resting red mesophilic relatives. A higher abundance of genes for compatible solute and sodium transport, important for cells of Haematococcus pluvialis, high in astaxanthin, fluoresce an excitation wavelength of 436 nm at 680-730 osmoregulation, was observed, likely necessary for survival in the salty brine veins of permafrost. We did not nm fully in the red spectrum. Results of the powdered pigment deposition field experiment showed that black see genome-wide cold adaptation for most of the amino acid features we investigated in the cryophiles, an pigments melted to the soil surface more quickly than blue or red, but red melted to the surface faster than indication that adaptation may be protein specific and not easily detectable on a large genome-wide scale. blue pigment. However, there were notable exceptions. We found significantly higher proportions of cold adapted proteins, with less proline residues, in Polaromonas sp. Eur3 1.2.1 compared to mesophiles. Kocuria sp. KROCY2, Astaxanthin is known to shield photosynthetic apparatus in the snow alga cell. As a fluorescent molecule, it Actinotalea sp. KRMCY2, and Methylobacterium sp. EUR3 AL-11 were cold adapted for serine and aromaticity, absorbs shorter wavelengths and re-radiates them at longer wavelengths and as heat. Longer wavelengths serine and glycine, and glycine and aromaticity, respectively. Comparing all cryophiles to all mesophiles, we and heat are more likely absorbed by ice and snow than short wavelengths, and this absorbed energy may found, on average, that cryophiles had a much higher ratio of cold adapted genes for serine, and to a lesser generate liquid water proximal to red algae cells. In contrast, green or yellow pigments would reflect wave- extent, proline and acidic residues. lengths less likely to be absorbed by ice and snow, and black-bodied alga cells run the risk of overheating. Conclusion: We found evidence for many cold adaptation genes in the cryophilic genomes, as well as genomic redundancy, theorized to be an important feature of cold adapted organisms. We also identified potentially Conclusion: We present preliminary theoretical, experimental, and field observations in support of the hy- conserved amino acid adaptations, important to maintain protein flexibility at low temperatures. This study pothesis that natural selection favors astaxanthin as a pigment that not only protects snow alga cells from has increased our understanding of the genetic basis of cold adaptation in permafrost microbes, and thus high levels of irradiance, but one that also acts as a direct mechanism of melting to produce liquid water in helps up better understand how these organisms behave and grow at subzero temperatures. a water-limited environment.

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[27] ASSESSMENT OF THE PHOTOTROPHIC POTENTIAL IN THE CRYOSPHERE BY LASER-INDUCED- [28] METAGENOMIC INSIGHTS INTO NITROGEN FIXATION IN GLACIAL FOREFIELDS FLUORESCENCE EMISSION (L.I.F.E.) Maisie Nash1, Alexandre M. Anesio2, Gary Barker3, Emiley Eloe-Fadrosh4, Liane G. Benning4, Patricia Sanchez- Klemens Weisleitner1, Birgit Sattler1, Marco Feldmann2, Gero Francke2, Clemens Espe2, Lars Hunger3, Michael Baracaldo2 4 5 6 Storrie-Lombardi , Albert Frisch , Christoph Kohstall 1 University of Bristol, United Kingdom 2 1 University of Innsbruck, Institute of Ecology, Austrian Polar Research Institute, Innsbruck, Austria University of Bristol 3 2 Fh Aachen University of Applied Sciences Faculty of Aerospace Engineering, Aachen, Germany Joint Genome Institute 4 3 University of Freiburg, Brainlinks-Braintools, Freiburg I.Br. , Germany University of Leeds 4 Kinohi Institute, Pasadena, United States 5 University of Innsbruck, Institute of Astro- and Particle Physics, Innsbruck, Austria Currently Arctic glaciers are undergoing retreat, stimulated by global climate change, with a likely increase in 6 Stanford University, Department of Physics, Stanford, United States the extent of deglaciation in future decades. Glacier retreat exposes soils which have been locked under ice for thousands of years, expanding the proglacial forefield. This newly exposed soil provides an opportunity to Aim: The standard methodology to detect microbial life in icy environments implies a severe manipulation of study how microbial communities colonise, modify soil biogeochemical cycles and influence the establishment the ecosystem and laboratory based approaches often lead to a falsification insituof conditions. Further, lo- of higher plants during succession. This is important for understanding the ecological significance of microbial gistic constraints at cryospheric study sites lead to data sets with low spatial and temporal resolution. Hence, communities in soil development, and the development of life in extreme environments. The evolving field data up-scaling and sample manipulation is not avoidable with common methods. Here, we present a novel of metagenomics allows the gene composition of entire microbial communities to be investigated. Metagen- prototype for the non-invasive in situ quantification of porphyrin biomarker molecules which are considered omics has yet to be applied to bacterial community succession in glacier forefields. Identifying the presence as indicators for the phototrophic potential in ecosystems. of functional genes using metagenomics will help isolate the importance of bacterial communities over successional gradients. For example, nitrogen fixing bacteria may be crucial in building labile nitrogen stocks in newly exposed soils, facilitating heterotroph and higher plant colonisation. Whilst SSU rRNA has been used Method: The prototype instrument detects and quantifies chlorophylla and B-phycoerythrin by using laser-induced fluorescence emission technology. L.I.F.E. occurs when matter absorbs a fraction of an incident laser to isolate nitrogen fixers in early soils, metagenomics can identify key functional genes for nitrogen fixation, beam and emits a longer wavelength (lower energy) photon. This method does not require sample preparati- providing genomic support for the presence of this process. However, metagenomic DNA sequencing supplies on, sample destruction, or consumable resources other than power. short read fragments, which limits downstream functional annotation. Consequently, metagenomic sequence assembly can be used to generate longer, more useful sequences for ecological analysis. Thus far, there has Results / Discussion: Based on previous prototypes we improved the hardware design and handling for work been no identification of the best assembler or assembly algorithm for complex soils data. This is important under extreme conditions. The main features include a temperature stabilized 16 bit Raman spectrometer, as more contiguous and comprehensive assemblies will elicit higher quality functional annotations and more temperature stabilized lasers (405nm and 532nm), a GPS unit, autofocus and a resistive touchscreen that reliable ecological conclusions. Furthermore, ecological studies utilising metagenome data have typically used can be controlled with gloves. It can be used as a handheld device or mounted on a tripod. Field tests were unassembled sequences. Whilst this can provide functional annotation, the quality and accuracy is restricted. performed during the TAWANI 2015 expedition at Lake Untersee, Dronning Maud Land, Antarctica. Here, we aimed to test current metagenome assemblers for complex soils data and apply the best performing assemblers to investigate microbial nitrogen fixation in glacier forefields. Conclusion: Spatial quantification of photo pigments in extreme habitats is of crucial importance in context with global change. Future climate models will benefit from our monitoring tool because high resolution data This study applied four artificially curated metagenomes of increasing complexity to five currently available from biological processes at the ice-atmosphere boundary have not been implemented in any climate models metagenome assemblers, spanning three assembly algorithms (de Bruijn Graph, Overlap Layout Consensus yet. Moreover, non-invasive tools provide far more reliable data of sensitive environments due to the lack of and Greedy). Overall, the ideal assembler produces the longest sequence lengths (contiguity) and incorpora- manipulation and should be the way to go when it comes to monitoring of subzero temperature habitats. tes all the input genomes (completeness). Findings show CLC and SPAdes assemblers, based on the de Bruijn Graph algorithm, perform best in both these metrics across all metagenomes. SPAdes assembler was subsequently used to assemble soil metagenomes sampled from glacial forefields in Greenland, Sweden and Sval- bard. The potential for nitrogen fixation was highlighted by BLAST searching 5 key nif genes (H,D,K,N,E) in each metagenome. Preliminary data identifies the presence of these genes in early soils in Svalbard, however these are absent from older, more established soils. This indicates that bacterial nitrogen fixers may have an important role in facilitating the build-up of early labile nitrogen stocks, facilitating further successional colonisation. The isolated nif genes were subsequently used in a BLASTp search against the NCBI-nr database, identifying a dominant group of the nitrogen fixing cyanobacteria, Nostocales, such asCalothrix, Scytonema and Nodularia. Overall, this analysis has identified suitable metagenome assemblers for soil bacterial communities, alongside applying these assemblers to highlight the role of bacterial communities in early nitrogen fixation.

39 Oral Abstracts Oral Abstracts

[29] EXPLORING THE DIVERSITY AND FUNCTIONAL CAPACITY OF ARCTIC PLASMIDS THROUGH [30] INVESTIGATING GENETIC ADAPTATIONS OF AIRBORNE MICROORGANISMS TO LONG- CULTIVATION-INDEPENDENT APPROACHES DISTANCE AEOLIAN TRANSPORT AND THEIR IMPACT ON ATMOSPHERIC PROCESSES IN THE HIGH ARCTIC Rose Layton1, Cédric Malandain1, Timothy Vogel2, Catherine Larose2 1 2 3 4 1 Enoveo, Lyon, France Tina Šantl-Temkiv , Ian Marshall , Stephanie Pilgaard , Kai Finster 2 Environmental Microbial Genomics, Laboratoire Ampère, Ecole Centrale de Lyon, Université de Lyon, Lyon, France 1 Dept. of Bioscience, Aarhus University, Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus, Denmark Aim: Plasmid-mediated gene transfer via conjugation is one of the most important mechanisms of horizontal 2 Center for Geomicrobiology, Aarhus University, Denmark gene transfer (HGT); a ubiquitous and central mechanism of bacterial adaption. Yet, the role of plasmids in 3 Department of Bioscience, Aarhus University , Denmark arctic microbial communities has received almost no attention. The presence of plasmids in arctic microbial 4 Aarhus University, Bioscience, Aarhus, Denmark isolates has confirmed their existence and ability to carry numerous genes of potential benefit to their host but very little is known about the plasmid population. Therefore, the main aim of this research was to elucida- Aim: Due to remote location and harsh conditions, studies of the Arctic atmosphere are difficult to carry out te and emphasize the role of plasmids in adaptation of arctic microbial communities. Our study also validated and thus our understanding of the Arctic meteorology and climate is limited. Studies in temperate regions a cultivation-independent method for detection and quantification of plasmid occurrence and abundance. have provided insights leading to the conclusion that airborne microorganisms impact weather and climate, as they may control the lifetime and extent of clouds. Thus, airborne microorganisms might also be an important Method: Existing metagenomes derived from a variety of habitats were mined for plasmid marker genes using missing link for predicting radiation budgets in the Arctic. In spite of their importance for the Arctic atmosphe- our self-curated database. In addition, plasmid DNA was isolated from total community DNA of snow meltwa- re, the quantities, sources, adaptations, and activity of airborne microorganisms and their atmospheric role ter and Arctic lake water samples, which were subsequently subjected to metagenomic sequencing. The deri- are not understood. We address this question by using a combination of cultivation, next-generation sequen- ved sequences were annotated functionally and compared to previously published plasmid metagenomes. cing, genome analysis, and ice-nucleation assays on atmospheric communities in the high Arctic.

Results / Discussion: Mining of metagenomic datasets for plasmid marker genes demonstrated that plasmid Method: The Villum Research Station provides unprecedented infrastructure for studying effects of airbor- populations were distinct between environments; a result later mirrored in the plasmid metagenomes. Func- ne microorganisms on cloud processes in the high Arctic. Over a period of 3 weeks, we collected a series of tionally, the arctic plasmid metagenomes differ significantly from plasmid metagenomes from other environ- air samples using high-volume impinger and filter samplers. Surface snow samples were also collected in a ments supporting selection of plasmids at a community level. The wide range of functions observed in plas- 50-km-long transect. The samples were collected for cell quantification, total nucleic acid (DNA and RNA) -ana mid metagenomes is an indication of their potential role as major contributors to arctic microbial adaptation. lysis, cultivation, and ice-nucleation assays. We quantified airborne bacteria and community activity potential by fluorescent microscopy and by qPCR targeting 16S rRNA and 16S rRNA genes. An ice-nucleation assay was Conclusion: For the first time, the functional capacity of the arctic plasmid metagenome has been elucidated. used to determine the number of total and proteinaceous ice nuclei. We described the cultivable microbial This work not only validated a method for the isolation of plasmid communities from habitats of low bacterial community and screened the isolates for ice nucleation activity. The genomes of 11 selected isolates were abundance but emphasized the importance of plasmids for arctic microbial community adaptation, and thus, sequenced and the presence of stress-related genes (cryoprotection, cold- and heat-shock genes, UV-damage provides a springboard for further research in this field. repair, oxidation protection, and pigment biosynthesis) was compared to genomes of their closest relatives from temperate environments, in order to infer adaptations that allow these strains to survive their long-distance transport.

Results / Discussion: We found a high air-concentration of bacterial cells (3.000–80.000 cells/m3) in this high Arctic region, indicating a large input of microorganisms, likely arriving there after long-distance aeolian transport. Surface snow cover (upper 10 cm) contained 100-1000 cells/mL, which were deposited there from the atmosphere. Over 180 isolates were found, belonging to Actinobacteria, Firmicutes, Alpha-, Beta, and Gammaproteobacteria. Although we could demonstrate that large proportion of total IN were proteinaceous, none of the bacterial strains either carried the ice-nucleation activity gene or had the phenotype. Stress-related genes that were found in high Arctic atmospheric strains were not more common compared to stress-related genes in strains from temperate regions, which implies that there has been no genetic adaptation in these dispersing cells. Thus, a variety of strains from temperate environments can serve as a source for cells found at this very remote and extreme Arctic location. Our aim is to compare the genomic data obtained so far with the metagenomic study of these communities, to investigate how common are these stress-related genes in these bacterial communities. Finally, qPCR and next-generation amplicon sequencing that will target 16S rRNA and 16S rRNA gene will be used to quantify the activity potential of these communities and to identify taxa with a high potential to express their genetic potential.

Conclusion: The results obtained in this study will contribute to understanding the importance of long distance dispersal of microbial cells to the Arctic and their role in high Arctic atmospheric processes.

41 Oral Abstracts Oral Abstracts

[31] UNIQUE BACTERIAL FE-REDOX CYCLING CHEMOLITHOTROPHIC COMMUNITIES BENEATH [32] NEW TERRESTRIAL MARS ANALOG HABITAT SITES IN THE PERMAFROST OF CONTINENTAL GREENLAND ICE SHEET IN THE NGRIP BEDROCKWATER ANTARCTICA

Sergey Bulat1, Elizabeth Rudaya1, Maxim Doronin1, Denis Karlov1, Robert Afasizhev1, Danyl Sumbatyan1, Jean-Pierre de Vera1, Schmitz Nicole1, Kounaves Samuel2, Läufer Andreas3, Hauber Ernst1 Dominique Marie2, Jean Martins3, Jean-Robert Petit3, Jorgen Peder Steffensen4, Dorthe Dahl-Jensen4 1 German Aerospace Center (Dlr), Berlin, Germany 1 Petersburg Nuclear Physics Institute, Nrc ‘kurchatov’ Institute, Gatchina, Russian Federation 2 Tufts University, Medford MA, United States 2 Station Biologique de Roscoff, Roscoff Cedex, France 3 Federal Institute for Geosciences and Natural Resources (Bgr), Hannover, Germany 3 Ige, Cnrs, Grenoble Inp, Ird, Uga Bo Box 96 , St Martin D’hères Cedex, France 4 Niels Bohr Institute, Copenhagen, Denmark Aim: Astrobiological investigations were performed in the Transantarctic Mountains within the study sites located in the Northern Helliwell Hills, Sothern Helliwell Hills (Boggs Valley) and in the Morozumi Range in North Aim: The objective was to recover bacterial life existing beneath the Greenland Ice Sheet (GIS) using the -se Victoria Land (~71.73°S/161.38°E) and were visited in the framework of the 10th and 11th German Antarctic quencing of bacterial 16S rRNA genes recovered in the NGRIP ice core sample originating from bedrock water North Victoria Land Expedition (GANOVEX X and XI) during the austral summer of 2009/2010 and 2015/2016. containing numerous reddish mineral inclusions. The local bedrock consists mostly of sedimentary rocks (sandstones) of the Beacon Supergroup and mafic igneous intrusions (Ferrar Dolerites). Within these rocks a variety of micro-niches such as fissures, cracks and Method: The sample was the moon-shaped ice segment (Bag15) from the 3045m depth. The ‘red’ part of the some structural micro-cavities within the fine-grained sedimentary rocks are colonized by a diversity of micro- segment was cut off, strictly decontaminated and treated under ‘clean room’ conditions. The cell concen- organisms. These micro-niches are protecting the organisms against extreme desiccation and UV-irradiation. trations were estimated by flow fluorocytometry and fluorescent microscopy. The SEM studies of particles Collected microorganisms of these Mars-analogue field sites are checked if they are able to survive or to be were performed using Jeon JSM-6400 (beam 1µm) scanning electron microscopy (UGA, Grenoble, France). metabolically active under simulated Mars-like conditions in the lab and in space. Different regions of 16S rRNA genes of bacteria (v3-v5, v4-v8, v4-v6, v4) and archaea (v1-v5и v3-v5) were amplified, clones and Sanger sequenced. Method: Through comparison to the surface of the planet Mars the geologically and geomorphologically well-defined macro- and micro-habitats can be classified as Mars-analogs, particularly due to the presence Results / Discussion: The cell concentrations failed to estimate due to particle autofluorescence. The SEM of liquid water at an air temperature below zero and the presence of perchlorates. A test series on collected studies of particles resulted in finding of Fe and Fe oxide everywhere. and isolated microorganisms from these potential Mars analog field sites started for checks on the ability to survive or even to live under simulated Mars-like conditions both in the laboratories and in space (de Vera et The comprehensive DNA analyses were conducted on 16S rRNA genes amplificons following DNA sequeincing. al. 2014). Metabolic activity and vitality tests were performed (CFU, CLSM, photosynthetic activity etc.). Archaea were not detected while bacteria gave a signal for all 4 gene regions tested. Of them two regions (v4 and v4-v8) gave only contaminant phylotypes while regions v4-v6 and v3-v5 allowed to recover 4 bacterial Results / Discussion: Some of the samples which were tested for 1.5 years on the International Space Station phylotypes all passing our contaminant criteria including the Contaminant Library (300 bacterial phylotypes). (ISS) in the frame of the ESA/DLR-space experiment BIOMEX (BIOlogy and Mars EXperiment, 2014-2016, de These 4 non-contaminant phylotypes were pulling out from 15 phylotypes in total. Vera et al. 2012)) show the high resistance of polar microorganisms to Mars-like environmental conditions simulated by Mars-like space exposure on the ISS. They mainly survive the conditions of simulated Mars The only v4-v6 region phylotype showed the conspecificity with the type culture ofRhodoferax saidenbachensis environment either in the lab or in space. of Beta-proteobacteria (Comamonadaceae) (Kaden et al., 2014) and identity with the Antarctic strain ofAlbi - diferax (Rhodoferax) sp (Peeters et al., 2011). The phylogenetic assessment of this phylotype showed its reliable Conclusion: These simulation experiments in the laboratory and these space tests performed by ESA, NASA clustering with the type culture of Rhodoferax ferrireducens, which can reduce Fe(III) (Finneran et al., 2003). and DLR additionally highlight how important the collaboration between Polar Research and Space Research is as a prerequisite to investigating the habitability of Mars and the ability of instruments to detect life in a very The sequencing of v3-v5 region resulted in discovery of 3 unknowns bacterial phylotypes (<80% similarity with extreme environment. The cooperation of these disciplines is also mandatory to find out if new investigated known taxa). The 1st phylotype assigning to Planctomycetes showed <98% similarity with DNA clones involved field sites are from a biological point of view real Mars-analogues and if microorganisms in these areas might in Fe-phyllosilicate redox cycling in sediments (Converse et al., 2015). The 2nd phylotype assigning to Parcubac- have relevance to survival or to be metabolic active on Mars. teria showed the family level similarity (<92%) with one soil DNA clone (Dunaj et al., 2012). Its phylogenetic assessment demonstrated reliable clustering with single DNA clones originating from the Fe-ions stratified Lake Pavin (Busigny et al., 2016) and iron-rich snow (Kojima et al., 2009). The 3rd phylotype remained uniden- tified and unclassified. The only closest DNA clone (91% - family level similarity) originated from pyroclastic surface (containing iron) following a volcano eruption Zeglin( et al., 2016).

Conclusion: Thus, 4 revealed phylotypes could testify for unknown bacterial Fe redox cycling chemolithotrophic communities existing beneath the GIS which are distinct from those thriving beneath Antarctic Ice Sheet (Beta-proteobacteria of Gallionellaceae (Bulat et al., 2016)).

Kaden et al. 2014. IJSEM 64:1186-1193 Peeters et al. 2011. Microb Ecol 62:399-413 Finneran et al. 2003. IJSEM 53:669–673 Converse et al. 2015. Front Microbiol 6:858 Dunaj et al. 2012. Environ Sci Technol 46:1914-1922 Busigny et al. 2016. In Lake Pavin (Sime-Ngando et al., eds), Springer, p. 205-220 Kojima et al. 2009. Syst Applied Microbiol 32:429-437 Zeglin et al. 2016. Environ Microbiol 18:146-158 Bulat et al. 2016. 34th SCAR OSC 2016, Kuala Lumpur, Malaysia, Aug 20-30, 2016, p. 136 43 Oral Abstracts Oral Abstracts

[33] MICROBIAL TRANSCRIPTIONAL RESPONSES TO THAWING AND FREEZING OF ACTIVE LAYER SOIL [34] THE MICROBIOTA OF ON-SHORE NATURAL GAS SEEPAGE POCKMARKS IN NORTHERN ICELAND Morten Schostag1, Carsten Suhr Jacobsen2, Samuel J.A. Jacquiod3, Flemming Ekelund3, Jakob Russel3, Cathrine Larose4, Timothy M. Vogel4, Lorrie Maccario4, Samuel Faucherre1, Anders Priemé5 Oddur Vilhelmsson1, Gudny Vala Thorsteinsdottir1, Anett Blischke2 1 Center for Permafrost, University of Copenhagen, Denmark 1 The University of Akureyri, Akureyri, Iceland 2 Aarhus University, Denmark 2 Iceland Geosurvey, Akureyri, Iceland 3 Department of Biology, University of Copenhagen, Denmark 4 Environmental Microbial Genomics, Université de Lyon, France Aim: Natural gas seepage pockmarks, thought to be at least partly derived from thermogenic gas, are found 5 University of Copenhagen, Section of Microbiology, Center for Permafrost (Cenperm), København K, Denmark on shore at two sites by Öxarfjörður bay in northeastern Iceland. These pockmarks are thought to harbour a microbiota adapted to continuous flushing with natural gas composed of short-chain alkanes and simple Aim: To investigate the transcriptional responses of microorganisms at different temperatures during warming aromatics. They thus present a rich environment for investigating natural populations of microbial degraders and freezing of active layer soil from Svalbard. of alkanes and aromatic compounds. The aim of the study was to characterize and compare the microbiotas at the two pockmark sites, which differ widely in terms of vegetation and geothermal input, as well as to Method: Metatranscriptomic data were obtained by extracting RNA from 2 gram of soil sample, cDNA and bioprospect them for hydrocarbon degraders. library production using NebNext Ultra Directional RNA library prep kit, and sequenced using Illumina HiSeq 150-bp paired-end technology.

Results / Discussion: The mRNA- and rRNA-based data revealed very small changes when warming from Method: Community analysis was conducted by QIIME on MiSeq libraries of 16S-targeted amplicons. o o o o -10 C to -2 C and when freezing from -2 C to -10 C. In contrast, we observed substantial changes when Thermogenic vs. biogenic gas origin was determined by δ13C analysis of gas collected from the pockmarks. Gas o o warming from -2 C to +2 C (e.g. an increase in mRNAs involved in production of stress related protein folding composition was assessed by GC analysis. Enricment and culturing of isolates was carried out under modified, o proteins, chaperones, and a dramatic decrease in fungal rRNA), when incubating at +2 C for 16 days (e.g. propane-enriched atmosphere. Hydrocarbon degradation was assessed in minimal media. an increase in ribosomal production, a large decrease in stress response, an increase inr -selected bacterial taxa, even more dramatic decrease in fungal rRNA and an increase in protozoa), and to a minor extent when Results / Discussion: Community analysis by 16S rDNA tag sequencing of DNA extracted from seepage pock- o o freezing from +2 C to -2 C (a small increase in stress response). In addition, the total amount of RNA did not mark samples reveal a strong dominance of anaerobic, dehalorespiring bacteria from the class Dehalococ- change during the experiment; the expression of genes involved in microbial stress response was higher du- coidia, suggesting a microbial ecosystem characterized primarily by anaerobic methane oxidation fuelled by ring the initial warming period compared to the subsequent freezing period; and we only found little evidence reductive dehalogenation. Several facultatively dehalorespiring bacteria are also present among the cultured of increased expression of genes involved in degradation of plant litter following thawing. Our data revealed bacteria, which also comprise a large number of facultatively lithotrophic Alphaproteobacteria and Betapro- that immediately upon soil thawing the bacteria expressed a stress response, which was followed by an teobacteria, suggesting considerable biogeochemical activity in the pockmarks, such as bioweathering and increase in potential activity of presumedr -selected bacteria and an increase in potential activity of protozoa. biodeposition activities. Preliminary investigations on the bioremediation potential of the isolated bacteria We hypothesize that protozoan grazing was not limited to the surge in r-selected bacteria, but also affected from the seepage pockmarks at both sites have revealed degraders of naphthalene, hexane and propane. presumed K-selected bacterial taxa that are likely to possess important roles in degradation of plant litter and soil organic matter. Conclusion: The methane seepage pockmarks of Öxarfjörður are host to fairly homogeneous populations of hydrocarbon-oxidizing and facultatively lithotrophic bacteria, some of which are easily cultured and may be Conclusion: Thus, the combination of initial stress response, decrease in potential fungal activity, initiation useful for bioremediation of hydrocarbons in oligotrophic environments. The populations appear dominated of general intracellular metabolism, and grazing of bacteria by protozoa potentially delay the degradation of by members of the class Dehalococcoidia. litter and soil organic matter upon thawing of active layer soil, which may have implications for our understanding and modelling of plant nutrient availability and CO emission from Arctic soils. 2

45 Oral Abstracts

[35] “BLACK BLOOM” PENICILLIUM SP. ON THE GREENLAND ICE SHEET

Laura Perini1, Jens Christian Frisvad2, Polona Zalar1, Cene Gostinčar1, Alexandre Anesio3, Nina Gunde- Cimerman1 FEMS MICROBIOLOGY ECOLOGY 1 Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia 2 Technical University of Denmark, Dept. of Microbial Ecology and Chemistry, Fungal Chemodiversity , Lyngby, Denmark Editor in Chief Max M. Häggblom 3 School of Geographical Sciences, University of Bristol, Bristol, United Kingdom

Melting of the Greenland Ice Sheet is accelerating. Part of the reason is the lowering of the ice albedo due to dark coloration of ice, which is most pronounced in SW Greenland. Dark ice absorbs more of the solar irradiation, facilitating the melting. Microbiologists and glaciologists assume that the darkening of the ice is caused Your natural research habitat by either or a combination of the presence of blooms of dark pigmented snow and ice algae, bacteria, dust and black carbon. Currently very little is known about the bacteria and algae that live on ice sheet surfaces and even less about saprotrophic fungi that might contribute to the control of the algal and bacterial growth and play a role in their degradation. Targeted sampling of fungal populations on Greenland black ice resulted so far in isolation of one overall dominant Penicillium species from the section Brevicompacta, most similar to P. bialowiezense and P. biourgeianum. This new psychrotolerant species differs from other known species in the sequences of the phylogenetic markers ITS, beta tubulin and RPB2, in the sporulation pattern and in the array of the produced secondary metabolites. The analysed secondary metabolite profile of the new species CALL FOR PAPERS: revealed that most strains produce antibiotic, antiviral and antifungal mycophenolic acid, antibiotic xanthoe- pocin, raistrick phenols, asperphenamate, quinolactacins, and phytotoxic and potentially antialgal breviones. POLAR AND ALPINE MICROBIOLOGY The production of secondary metabolites was very consistent between all 39 examined isolates. All isolates produced several derivatives of mycophenolic acid, including mycochromenic acid, mycophenolic acid diol lactone and ethylmycophenolate. The new species appears to be specifically associated to the ice algae and may play a role in its biocontrol and degradation or maybe in its protection and proliferation. The study of the enzymatic profiles and transcriptomes of this newPenicillium sp. are in progress. Submit your research to a thematic issue that will focus on the roles of microorganisms in the warming cryosphere. Microorganisms are dominant in these cold environments, which span from Arctic to Antarctic, high mountain ranges the deep ocean, including permafrost, marine sediments, sea- and glacial ice, and snow. Knowledge of the distribution, biodiversity and functional roles of microorganisms inhabiting polar and alpine environments is essential to our understanding of ecosystem processes in a changing climate. Poster Abstracts

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Microbial_AD.indd 1 25/08/2017 11.21 Poster Presentations Poster Presentations

No. Title Presenting author No. Title Presenting author 1 Contamination of the Arctic reflected in microbial metagenomes Aviaja Hauptmann 21 Standardized Pipeline for FULL RNA no PCR Biased Analysis of the Muhammad Zohaib Anwar from the Greenland ice sheet Microbial populations in Arctic Environment 3 Microbial community development during the glacial-proglacial Petra Vinšová 22 The Geochemistry of Surface Ice on the Greenland Ice Sheet and Alexandra Holland ecosystem transition its effect on the Primary Production of Microbes 4 Microbial diversity of glacier ice and subglacial streams from Cristina Purcarea 23 Greenlandic enzymes for biocatalysis of prebiotic oligosaccharides Mariane Schmidt Thøgersen King George Island 24 Bioprospecting for novel antimicrobial drugs from microbes in glacial Aliyah Debbonaire 6 Microbial communities from a surging glacier stream network on Tyler J. Kohler environments Qeqertarsuaq (Disko Island), West Greenland 25 Mining the Arctic microbial metagenome for industrially useful Melanie Hay 7 Environmental factors associated with snow algal bloom in the Akane Watanabe cold-active enzymes deciduous forest of Mt. Gassan, Yamagata prefecture, Japan 29 The effect of permafrost thaw on circum-Arctic methanogenic Stine Holm 8 Hortaea thailandica, a tropical fungus in Arctic glaciers Polona Zalar communities 9 Reconstruction of Scarisoara ice cave microbiome based on 16S Cristina Purcarea 30 Genomic analyses of Psychrobacter species from permafrost Corien Bakermans rRNA gene sequencing and shotgun metagenomics 31 Identifying Changes in the Active, Dead, and Dormant Microbial Alex Burkert 10 Analyses of bacterial community structures associated with Takumi Murakami Community Structures Across a Chronosequence of Ancient glacier-adapted invertebrates Alaskan Permafrost 11 Establishment of functional microbial communities and nutrient Silvia Gschwendtner 32 Shifts in microbial and plant diversity above thawing discontinuous Robyn Barbato cycling processes during ecosystem development permafrost in high latitude ecotones 12 A computational pipeline for taxon, gene and allelic analysis of Gilda Varliero 33 Carbon Metabolism in Pleistocene Permafrost Microbial Tara Mahendrarajah microbial metagenomes Communities 13 Geochemical and microbiological gradients along an Arctic Lucie Malard 34 Physiological adaptations of cryoconite microorganisms to Ewa Poniecka chronosequence anoxia 14 Lipopolysaccharide molecular structure from the cold-adapted Angela Casillo 35 Molecular diversity snapshot of glacial algae Jakub Žárský Shewanella sp. HM13 36 A model of virus-host interactions in sea ice brines incorporating Gordon Showalter 15 Symbiotic nitrogen fixation in lichens and bryophytes in a warming Ingeborg Klarenberg dynamics of cold-adapted Colwellia psychrerythraea strain 34H Arctic and Colwelliaphage 9A 16 The functional profiles of endophytic bacteria associated with Cindy Given arcto-alpine plant: Oxyria digyna 17 Abundance and diversity of potentially pathogenic bacteria from Diana Mogrovejo Arctic environments and the risks they pose 18 Warming and reduction of precipitations affect the microbiome Aline Frossard of recently deglaciated soils in the Swiss Alps 19 Vegetation changes arising from grazing alters the SOC composition, Kathrin Bender the microbiota and its activity in High-Arctic peatlands 20 Optimization of Air Sampling Efficiency at Subzero Temperatures Nora Els applying Liquid Impinging and Membrane Filtration

51 Poster Abstracts Poster Abstracts

[P1] CONTAMINATION OF THE ARCTIC REFLECTED IN MICROBIAL METAGENOMES FROM THE [P2] PSYCHROTROPHIC FUNGI FROM TIRICH MIR GLACIER (PAKISTAN), THEIR ANTIMICROBIAL GREENLAND ICE SHEET ACTIVITY AND PRODUCTION OF INDUSTRIALLY IMPORTANT ENZYMES

Aviaja Hauptmann1, Thomas Sicheritz-Pontén2, Karen A. Cameron3, Jacob Bælum4, Damian R. Plichta5, Muhammad Rafiq1, Shaukat Nadeem2, Noor Hassan2, Aamer Ali Shah2, Fariha Hasan2 Marlene Dalgaard2, Marek Stibal6 1 Department of Microbiology, Quaid-I-Azam University, Islamabad, Pakistan, Department of Microbiology, Abdul Wali Khan 1 Ilisimatusarfik , Nuuk, Greenland University, Mardan, Pakistan, Pakistan 2 The Technical University of Denmark, Kgs. Lyngby, Denmark 2 Department of Microbiology, Quaid-I-Azam University, Islamabad, Pakistan 3 Aberystwyth University, Aberystwyth, United Kingdom 4 Chr. Hansen A/S, Hørsholm, Denmark Aim: The potential of psychrotrophic fungi from Tirich Mir glacier, Hindu Kush (Pakistan), to demonstrate 5 Clinical-Microbiomics, Copenhagen, Denmark antimicrobial activity and production of extracellular enzymes, was evaluated. 6 Charles University, Prague, Czech Republic Method: The samples (glacier sediments, ice) were collected aseptically from Tirich Mir glacier of the Hindu Aim: Assess the microbial potential for resistance to and degradation of contaminants including PAHs, PCB, Kush Range. Sabouraud Dextrose Agar (SDA), Potato Dextrose Agar (PDA) and Malt Extract Agar were used for mercury and lead in microbial communities from cryoconite on the Greenland ice sheet. the fungal isolation. Two different incubation temperatures (4°C and 15°C) were used for isolation. CFU/ml or g was determined for all the samples. The morphological characteristics were recorded in terms of colony Method: Metagenomic data was used to look for microbial genes that confer resistance to and degradation of growth. DNA of all the fungal isolates was extracted and PCR amplification of the extracted DNA was done contaminants as well as bioinformatical binning of full microbial genomes from metagenomic data. using ITS1 and ITS4. The amplified fungal DNA was sequenced and analyzed. The fungal isolates were characterized on different physiological parameters including growth at different temperature (4, 15, 37, 45 and Results / Discussion: Of 24 annotated genomes bins 13 were complete based on their content of marker 50°C), pH (1-11), media (SDA, TSA and PDA) and salt concentration (2-20%). ATCC bacterial strains, clinically genes. Seven of the genomes had closest neighbors isolated from contaminated habitats. Samples from isolated bacterial and fungal strains were selected such as Bacillus sp. ATCC 6633, E. coli ATCC 10536, Staphy- Tasiilaq (SE) had the highest read counts of genes for degradation of PCB and resistance to mercury. PCB and lococcus aureus ATCC 6538, Klebsiella pnuemonae (clinical isolate), Pseudomonas aeruginosa (clinical isolate), mercury contamination is also the highest among Inuit in Tasiilaq. Kangerlussuaq (W) and Thule (N), sites with Candida albicans (clinical isolate) and Aspergillus flavus (clinical isolate). The antimicrobial activity procedure the largest airports of Greenland, had highest read counts of genes for degradation of PAHs, a byproduct of was carried out by point inoculation method. All fungal isolates were checked for amylase, cellulase, deoxyri- incomplete combustion of fuels. Dark Site (W) had the highest read counts of genes for resistance to lead. All bonuclease and lipase activities. samples had above 8000 reads mapping to heavy metal resistance genes and a couple of samples from Tasii- laq had above 18000 reads. Using human gut metagenomic samples as negative control none of the above Results / Discussion: A total of 44 fungi representing 16 genera, 1 family, 1 order and 1 class, were isolated genes were found in these samples. from all the samples. Penicillium was found to be the dominant genus followed by Cladosporium, Didymel- la, Phoma, Coprinopsis, Epicoccum, Ulocladium, Onygenales (family), Ascochyta, Aspergillus, Comoclathris, Conclusion: There is a microbial potential for resistance to and degradation of contaminants on the Greenland Davidiella, Geomyces, Irpex, Pseudogymnoascus, Scopulariopsis, Tomicus, Davidiellaceae (order) and Dothi- ice sheet. The potential is variable but is found at all sampling regions including the North, South, Southeast deomycetes (class). Fungal isolates showed remarkable growth on different pH (2-11), temperatures (4-37°C) and West. The Greenland ice sheet should be disregarded as a pristine environment. More attention should and NaCl concentrations (2-18%). Fungal isolates,Comoclathris spartiiand Davidiella tassiana tolerated up to be paid to the potential release of contaminants from the ice sheet. 18% of NaCl and pH from 2-11, respectively. Antimicrobial activities of fungal isolates against ATCC bacterial strains, clinically isolated bacterial and fungal strains were quite promising. Ulocladium sp. and Onygenales sp. showed activities against both bacterial (Gram positive and Gram negative) and fungal strains. Fungal isolates were also checked for their ability to produce various industrially important extracellular enzymes (amylase, cellulase, deoxyribonuclease and lipase). Penicillium chrysogenum produced three important enzymes i.e. amylase, cellulase and deoxyribonuclease.

Conclusion: It is the first report regarding isolation of psychrotrophic fungi from Tirich Mir glacier. Morp- hological and molecular analysis revealed Penicillium as most an abundant isolated genus. They were very adaptable by growing at a wide range of temperature, pH and salt conditions, and were also proficient in antimicrobial metabolites and enzyme production at low temperatures.

53 Poster Abstracts Poster Abstracts

[P3] MICROBIAL COMMUNITY DEVELOPMENT DURING THE GLACIAL-PROGLACIAL ECOSYSTEM [P4] MICROBIAL DIVERSITY OF GLACIER ICE AND SUBGLACIAL STREAMS FROM KING GEORGE TRANSITION ISLAND

Petra Vinšová1, Lukáš Falteisek1, Tyler J. Kohler1, Jakub D. Žárský1, Jacob C. Yde2, Marek Stibal1 Corina Itcus1, Constantin Marin2, Soon Gyu Hong3, Cristian Coman4, Iris Tusa1, Manuela E Sidoroff1, Cristina Purcarea5 1 Charles University, Faculty of Science, Department of Ecology, Prague 2, Czech Republic 2 Western Norway University of Applied Sciences, Faculty of Engineering and Science, Sogndal, Norway 1 National Institute of Research and Development for Biological Sciences, Bucharest, Romania 2 Emil Racovita Institute of Speleology, Bucharest, Romania As a glacier retreats, its subglacial ecosystem becomes exposed to the atmosphere, forming a proglacial 3 Korean Polar Research Institute, Division of Life Science, Incheon, Korea, Rep. of South ecosystem standing at the onset of ecological succession (microbes, plants) and soil formation (pedogenesis). 4 Institute of Biological Research, Cluj Napoca, Romania The environment changes drastically, from the dark, mostly anoxic, and nutrient-poor subglacial environment 5 Institute of Biology, Bucharest, Romania to the oxygenated and irradiated proglacial environment. Traces of supraglacial habitats (e.g. cryoconite holes) are also left behind the retreating glacier, with the remaining supraglacial material mixing with subglacial Aim: To investigate the impact of glacier retreat on perennial ice-embedded microbial communities, we sediments. examined the microbial diversity from glacier ice and subglacial streams of various locations of King George Island, NW Antarctica, in two consecutive years. These newly exposed and formed habitat at the glacier front is colonized by microbes. The structure of the developing microbial community changes rapidly, accompanied by changes in metabolic activity due to the Method: Glacier ice and subglacial stream samples were collected from Barton Peninsula, Weaver Peninsula changing carbon and nutrient sources. At present, it is not clear whether the glacial-to-proglacial transition and Potter Cove areas during ROICE 2015 and ROICE 2016 field trips at King Sejong Station KOPRI. Cultu- in the microbial community composition and activity is mostly due to an aerial input of new cells, or if it is a red microbiota was obtained at 4°C and 15°C using 1 x R2B and 1:50 diluted media. Resulted colonies were result of changes in the active members from the original glacial communities. analyzed by Scanning Electron Microscopy and identified by 16S rRNA gene sequencing. Physicochemical and chemical analyses were carried out for both stream water and melted ice samples. Genomic DNA was isolated To improve our understanding of the glacial-proglacial transition process and the associated changes in micro- in triplicate from all ice and subglacial stream samples, and the diversity of prokaryotes (bacteria and archaea) bial diversity and activity, we present here a set of long-term laboratory experiments designed to simulate the and fungi from these glacial habitats based on 16S rRNA and ITS2 genes, respectively, was determined using merging of the supra- and subglacial ecosystems and to monitor the development of the microbial community an Illumina MiSeq platform. in the new ecosystem. We hypothesize that the resulting microbial community will be a mixture of the most successful competitors from ecosystems merged, and that it gives rise to the proglacial community. Results / Discussion: Cultured bacteria was obtained at both low and high temperatures, with isolation of 102 colonies from glacier ice and 88 colonies from subglacial streams. SEM analysis of both microbial communities and isolated colonies revealed the presence of cocci, bacilli and filamentous microorganisms, the dominant morphotype varying with the sample location. The identified bacterial strains based on 16S rRNA gene- se quence belonged to Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria phyla, with a high represen- tion ofGammaproteobacteria, the majority being homologous to cold environments bacteria. Geochemical parameters of melted ice samples showed significantly lower pH, TDS and TOC values of glacier ice relative to those of the subglacier water, suggesting the enrichment of the latter one with geochemical compounds at the interface glacier/forefield with expected impact on its microcosm. All glacier ice samples were rather

homogenous, belonging to Na-HCO3 type, with a higher Ca content in the vecinity of subglacier streams, while the stream water was more heterogenous, corresponding to Na-Ca-HCO3 and Na-Cl types. Trace elements analysis revealed the presence of high concentrations of Al, Fe and Sr, in particular in the subglacial stream water. Illumina MiSeq sequencing of 51 glacier ice samples and 42 subglacial water and sequence analysis for both 16S rRNA and ITS2 amplicons is currently underway, revealing structural and temporal variations of microbial communities between the two types of habitats. Conclusion: Spatial distribution of microbial communities in glacier transects of Barton and Weaver peninsu- las and comparison of subglacial streams microbiome collected during 2 successive days and years, contributes to understanding the putative impact of melting glaciers on microbial community structure and their resilience, in correlation with the geochemistry of the these glacial habitats.

This study was financially supported by INCDSB Core Project PN 0936108 and H2020 EraNet-LAC ELAC2014/ DCC0178 Joint Program. We thank the team of King Sejong Station (KOPRI, Republic of Korea) for logistic support.

55 Poster Abstracts Poster Abstracts

[P5] CULTURABLE MICROBIAL DIVERSITY OF HIMALAYAN CRYOCONITES [P6] MICROBIAL COMMUNITIES FROM A SURGING GLACIER STREAM NETWORK ON QEQERTARSUAQ (DISKO ISLAND), WEST GREENLAND Shiv Mohan Singh1, Alok Kumar Srivastava2 1 2 3 2 4 1 National Centre for Antarctic & Ocean Research, Ministry of Earth Sciences, Govt of India, Vasco-Da-Gama, India Tyler J. Kohler , Jakub D. Žárský , Jacob C. Yde , Lukas Falteisek , Guillaume Lamarche-Gagnon , Jon 4 2 2 Icar-National Bureau of Agriculturally Important Microorganisms (Nbaim) , Kusmaur, , Mau Nath Bhanjan, Uttar Pradesh, Hawkings , Marek Stibal India 1 Charles University, Faculty of Science, Department of Ecology, Prague, Czech Republic 2 Charles University, Prague, Czech Republic Aim: Culturable microbial diversity of Himalayan Cryoconites 3 Western Norway University of Applied Sciences, Sogndal, Norway 4 University of Bristol, Bristol, United Kingdom Method: Sampling, Phenotypic characterization of the bacterial strains, Screening for enzymatic activities, Antibiotic susceptibility, DNA extraction, Polymerase chain reaction (pcr) and sequencing, Sequence align- Aim: Bacterioplankton plays critical functional roles in aquatic ecosystems, yet much remains to be lear- ment and Phylogenetic analysis, ned about how these communities are formed. Previous studies of temperate streams have found greatest microbial diversity at headwaters, which is hypothesized to be due to the high drainage area-to-stream width Results / Discussion: Cryoconite holes have biogeochemical and ecological importance. Culturable bacterial ratio, favoring the outcomes of dispersal over competition. Similar to temperate headwaters, glacial meltwa- diversity from Himalayan cryoconites was assessed. A total of 105 morphologically distinct bacterial isolates ters drain large areas of ice surface area relative to stream width, and contain high proportions of supra- and were isolated. Based on 16S rRNA gene sequence data, the identified species belonged to eight genera name- subglacially derived cells. Because of this, glacial meltwater assemblages are also suggested to be a product ly Cryobacterium, Janthinobacterium, Duganella, Pseudomonas and Psychrobacter. Among these of origins, though studies addressing this question, and its downstream implications, are wanting. Here, we Janthinobacterium is the most dominant genus. The isolates varied in their growth temperature, NaCl toleran- compare the meltwater communities of tributary glaciers with the river into which they drain to evaluate if ce, growth pH, enzyme activities, carbon utilization and antibiotic sensitivity tests. Fatty acid profiles indicate microbial diversity accumulates or is lost downstream within a glacial river catchment. We hypothesized that if the predominance of branched fatty acids in the isolates. Based on ITS/D1/D2 gene sequence data, the identi- dispersal is the dominant structuring mechanism, we should see greater diversity in the larger river compared fied fungal species belonged to nine genera namelyAlternaria, Cystofilobasidium, Cystofilobasidium, Cryp- to its tributaries. For further insights into possible sources, we also compared meltwater communities with tococcus, Leucosporidium, Rhodotorula., Mortierella, Glaciozyma, Preussia. Among these Cryptococcus and those from recently exposed subglacial sediment to assess the relative contribution of this compartment to Rhodoturala are the most dominant genera. To the best of our knowledge, this is the first record of culturable the assemblages in transport. bacterial communities and their characterization from glacier cryoconites from Himalaya. Method: Our survey was conducted within the Kuannersuit Valley on central Qeqertarsuaq (Disko Island), Conclusion: The present study was focused on characterizing the bacterial communities present in the glacier West Greenland. We sampled meltwater microbial communities from four tributary glacier outlets (numbe- cryoconites of Himalaya. To the best of our knowledge this is the first record of culturable bacterial commu- red 6, 10, 11, and 13), as well as the much larger Kuannersuit (KG) River into which they drain. Briefly, three nities and their chronological characterization rom the cryoconites of Himalaya. Carbon utilization abilities of replicate microbiological samples were taken from the water column of each stream near the glacial outlet the isolates indicate that the bacterial isolates prefer varied forms of carbon sources. The isolates also show by sterile syringe and passed through Sterivex filters. To compare meltwater communities with corresponding varied responses to antibiotics indicating that although the bacterial diversity in these microhabitats is limited, sediment samples, we transferred recently exposed sediments into sterile Eppendorf tubes. All samples were the strains differ widely in their antibiotic sensitivity characteristics. This adaptation strategy most likely helps promptly treated with nucleic acid preservative and frozen in the field. In the laboratory, nucleic acids were the microbial strains to overcome the antagonistic stresses and survive in all possible unique environments. extracted and sequenced for the 16S rRNA gene with Illumina MiSeq. Resulting sequences were assigned to Enzyme producing ability of the isolates demonstrates their biotechnological potential. High cellulose and OTUs, quality checked, and analyzed with multivariate statistical methods. lipase activities expressed by most of isolates provide a clue to the potential applications of these microbes. The organisms have probably evolved adaptation mechanisms for carrying out metabolic activities for growth Results / Discussion: We found meltwater communities to be comprised of taxa typical of glacial meltwater and survival at low and even at sub-zero temperatures. This ecological behaviour is of great interest and futu- streams reported previously. Expectedly, when plotted in an nMDS ordination, the tributary streams clustered re studies on this aspect needs carried out to understand their functioning at molecular level. more closely together, while the KG River clustered apart. However un-expectedly, individual tributary glaciers each had greater diversity than that draining from the KG River. In addition, tributary water column communities were distinct from corresponding marginal sediment communities, though were more similar in the case of the KG River. These results (along with complementary water chemistry data) suggest that the smaller glaciers had greater supraglacial inputs, which likely increased the overall diversity. In the case of the KG River, the lower diversity, distinct flora, and similarity to marginal sediments may be a result of proportionally greater subglacially-sourced sediment in transport, which dilutes the signature of other incoming microbes entering the river at lower concentrations.

Conclusion: While we maintain that glacial meltwater streams are formed through high dispersal rates, the tributaries of the Kuannersuit Valley catchment exhibited greater diversity than the KG River into which they drain. This pattern is consistent with that observed for temperate rivers, though due to very different mechanisms. We suggest that, in this case, the downstream reduction in diversity is due to a proportionally more homogeneous source, rather than competition, which is thought to reduce diversity in temperate streams.

57 Poster Abstracts Poster Abstracts

[P7] ENVIRONMENTAL FACTORS ASSOCIATED WITH SNOW ALGAL BLOOM IN THE DECIDUOUS [P8] HORTAEA THAILANDICA, A TROPICAL FUNGUS IN ARCTIC GLACIERS FOREST OF MT. GASSAN, YAMAGATA PREFECTURE, JAPAN Polona Zalar1, Cene Gostinčar1, Nina Gunde-Cimerman1 1 1 2 Akane Watanabe , Nozomu Takeuchi , Jun Uetake 1 Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia 1 Graduate School of Science, Chiba University, Chiba, Japan 2 National Institute of Polar Research, Japan Aim: The black yeast genus Hortaea (Teratosphaeriaceae, Capnodiales) currently comprises three species: halophilic Hortaea werneckii (Gunde-Cimerman and Zalar, 2015), acidophilic Hortaea acidophila (Hölker et Aim: Blooms of snow algae visibly appear on open snowfields in polar and alpine regions as usually red snow, al. 2004) and phylloplane inhabitingHortaea thailandica (Crous et al. 2009). H. werneckii and H. thailandica but also on snow at the forest floor as mostly green snow. Such snow algae at the forest floor may have a are closely related, whereas H. acidophila is only distantly related and needs reassignment to another genus different life history from those on open snowfields since the snow at the forest floor may be associated with (Selbman et al., 2008). Hortaea werneckii is the dominant fungus in brines all over the world and thus well trees and other organisms living in the forest. However, their life history and the conditions of their blooms at adapted to environments with low water activities. It is the model organism for the study of adaptations to the forest floor are still not understood well. This study aims to describe the temporal change of snow algae hypersaline environments. Adaptations were studied on the level of plasma membrane composition, intracel- and physical and chemical conditions of snow in the deciduous forest in Japan and discuss the conditions lular osmolyte composition and concentration of ions, structure and melanization of the cell wall, high osmo- causing the algal bloom. larity glycerol signaling pathway and differential gene expression, etc. all reviewed in Gostinčar et al (2011).H. werneckii was the first halophilc fungus for which the genome of was published (Lenassi et al. 2013). To our Method: The field investigations were conducted three times (11, 25 April, and 9 May in 2016) over the surprise the genome showed an almost complete duplication, an extraordinary feature in fungi that was besi- melting season in Mt. Gassan, Yamagata prefecture, Japan. Study site is located an elevation of 750 m a.s.l. des for H. werneckii so far described only for Rhizopus oryzae (Dujon, 2015). The genome of H. acidophila was in the Japanese beech forest, where more than 3 m of snow is accumulated in winter. We collected snow sequenced, but not yet published, while the genome of the extremely rare black yeast Hortaea thailandica, of samples from the surface and a vertical snow pit. Chlorophyll-a, EC, pH, and major soluble ions in the samples which only 2 strains are known, is in progress. were measured. Algae in the samples were observed with a microscope and were identified with 18S rRNA gene. Method: Morphology, temperature profile, and NaCl tolerance, enzymatic profile of H. thailandica isolate EXF-4028 (from Ex culture collection: http://www.ex-genebank.com/index.php/en/) will be studied and com- Results / Discussion: Green algal snow was not observed on 11 April, but appeared patchy on 25 April at the pared to selected Hortaea werneckii strains. Comparative genomic analyses will be performed. forest floor. The green snow mainly contained spherical and oval shaped green algal cells. 18S rRNA gene analysis revealed that the snow algae were dominated by Chloromonas platystigma and Chloromonas miwae. The Results / Discussion: The above mentioned study is in progress. algal patches were observed often on the surface under the trees compared with on the open sunny surface. The chlorophyll-a concentration gradually increased in the snow under the trees during the study period. The References: Crous PW, Schoch CL, Hyde KD, Wood AR, Gueidan C, de Hoog GS, Groenewald JZ (2009) Phyloge- phosphate concentrations were low at the beginning of the study period in the snow both under the tree (< netic lineages in the Capnodiales. StudieS in Mycology 64:17–47 11.2 μeq/L) and open area (< 12.5 μeq/L), but increased up to 51.4 μeq/L under the trees while kept low va- Dujon B (2015) Basic principles of yeast genomics, a personal recollection. FEMS Yeast Research 15, fov047 lue in the open snow surface. These results suggest that the phosphate was supplied by the canopy drip from the trees to the snow surface and induced the algal bloom. Gostinčar C, Lenassi M, Gunde-Cimerman N, Plemenitaš A (2011) Fungal adaptation to extremely high salt concentrations. Advances in applied microbiology 77:71-96 Conclusion: Snow algae inhabiting in deciduous forest are likely to use phosphate supplied by the trees. Gunde-Cimerman N, Zalar P (2014) Extremely halotolerant and halophilic fungi inhabit brine in solar salterns around the globe. Food technology and biotechnology 52:170-179 Lenassi M, Gostinčar C, Jackman S, Turk M, Sadowski I, Nislow C, Jones S, Birol I, Gunde Cimerman N, Pleme- nitaš A (2013) Whole genome duplication and enrichment of metal cation transporters revealed by de novo genome sequencing of extremely halotolerant black yeast Hortaea werneckii. PLoS One 8 (8):e71328 Selbmann L, de Hoog GS, Zucconi L, Isola D, Ruisi S, Gerrits van den Ende AHG, Ruibal C, De Leo F, Urzì C, On- ofri S (2008). Drought meets acid: three new genera in a dothidealean clade of extremotolerant fungi. Studies in Mycology 61:1–20

59 Poster Abstracts Poster Abstracts

[P9] RECONSTRUCTION OF SCARISOARA ICE CAVE MICROBIOME BASED ON 16S RRNA GENE [P10] ANALYSES OF BACTERIAL COMMUNITY STRUCTURES ASSOCIATED WITH GLACIER- SEQUENCING AND SHOTGUN METAGENOMICS ADAPTED INVERTEBRATES

Corina Itcus1, Madalina D Pascu1, Victoria I Paun1, Aurel Persoiu2, Alexandra Hillebrand-Voiculescu2, Traian Takumi Murakami1, Takahiro Segawa2, Nozomu Takeuchi3, Roman Dial4, Pedro Labarca5, Gonzalo Barcaza Brad3, Cristina Purcarea1 Sepulveda6, Shiro Kohshima7, Yuichi Hongoh8 1 Institute of Biology, Bucharest, Romania 1 Tokyo Institute of Technology, O-Okayama, Meguro-Ku, Tokyo, Japan 2 Emil Racovita Institute of Speleology, Bucharest, Romania 2 Yamanashi University, Japan 3 Emil Racovita Institute of Speleology, Cluj Napoca, Romania 3 Chiba University, Japan 4 Alaska Pacific University, United States Aim: Glacial habitats represent an important model for exobiology and palaeoclimate reconstruction, and a 5 Centro de Estudios Cientificos, Chile major source of microbial strains and extremozymes for biotechnologies. Our study focused on characterizing 6 Dirección General de Aguas, Chile the structural and functional microbial diversity from the perennial ice block harbored in Scarisoara Ice Cave, 7 Kyoto University, Japan Romania, in relation to climatic aspects, and the age and geochemical composition of the ice substrate. 8 Tokyo Institute of Technology, Japan

Method: Ice samples of 1, 400, 900, 1500 and 2000 years BP of high and low organic sediment content were Aim: In recently decades, microbiological investigations on glaciers have intensely been conducted; never- collected by vertical drilling of the cave ice block. Microbial cell content was quantitated by flow cytometry. theless, glacier invertebrates and their association with microorganisms have scarcely been studied. Since gla- Cultured bacteria were obtained in R2B medium at 4°C and 15°C, and isolated colonies were analyzed by cier invertebrates are the putative predominant consumers on glaciers, it would be important to take their ac- scanning electron microscopy and identified by 16S rRNA gene sequencing. Bacterial and fungal diversity of tivity into account for the comprehensive understanding of the glacier ecosystem. To understand the ecology ice samples up to 2000 years old were determined by 454 pyrosequencing of 16S rDNA and Illumina MiSeq of these glacier invertebrates in detail, we have been focusing on microbial consortium associated with them. sequencing of ITS amplicons, respectively. Geochemical analyses of the ice substrate were performed and Many studies have reported that microbial symbiosis have large influence on the host activity and ecosystems correlated with the microbial diversity pattern. Shotgun metagenomic sequencing was carried out using an through nutrient supply and material cycles. Given that the glacier is a harsh environment (i.e. cold, low Illumina HiSeq platform. nutrient and low biodiversity), the association between glacier invertebrates and microbiota would contribute to the adaptation of invertebrates to the glacier environment and the material cycles in the glacier ecosystem. Results / Discussion: The microbial content of different layers of Scarisoara ice block ranged in the 104-106 In this study, in order to obtain fundamental information on the association between glacier invertebrates and cells mL-1 interval. Bacterial OTUs identified throughout the ice block belonged to Gammaproteobacteria, microbiota, we analysed the bacterial community structures physically associated with the glacier ice worm Firmicutes, Bacteroidetes, and Actinobacteriarepresentatives reported in various cold environments and Mesenchytraeus solifugus and glacier stonefly Andiperla willinki based on the 16S rRNA sequences. karst habitats. While recent ice embedded microbiota was dominated by Gammaproteobacteria, Firmicutes constituted the major phylum of Little Ice Age formed ice. BothBacteroidetes and Gammaproteobacteria Method: DNA and RNA were simultaneously extracted from the entire body of ice worms, or the gut and showed dominated the ice layers formed during the warmer Medieval Warm Period. The dominant bacterial feces of the glacier stoneflies. Amplified bacterial 16S rRNA were deeply sequenced with the Illumina MiSeq. phyla showed variations with both the age and C/N content of the ice substrate. Archaeal phylotypes were We also analysed the bacterial community structures of habitat glacier surfaces for comparison. Additionally, identified only in old ice strata, with a higher representation of autotrophic or heterotrophic metabolism the localization of several dominant phylotypes in the host’s gut/body were identified by using fluorescence in depending on the organic content of ice substrate. The fungal community present in the cave ice belonged situ hybridization (FISH). to Ascomycota, Basidiomycota, Cryptomycota, Zygomycota, Cercozoa, with a high representation ofMrakia, Aureobasidium, Teberdinium and Mucorales genera. Shotgun sequencing of 7 ice samples gDNA resulted Results / Discussion: Bacterial community structures associated with ice worms and glacier stoneflies were in 33,000-39,000 reads and 9-10 million bases, and the metagenome reconstitution of their microbiome is distinct from those on their respective habitat glacier surfaces. In the ice worms, both glacier-indigenous currently underway in order to unravel the functional variability of microbial communities across the cave ice and animal -associated bacterial lineages were detected. By using FISH, a Mollicutes phylotype, which was block. affiliated with an animal-gut-associated bacterial lineage, and putatively glacier-derivedArcicella phylotypes were specifically detected on the gut wall and epidermis of ice worms, respectively. Both of them were almost Conclusion: Our data on the microbial diversity from Scarisoara ice block, based on 16S gene pyrosequencing, exclusively detected from ice worm samples and scarcely detected from habitat glacier surface samples, sug- ITS2 Illumina sequencing and metagenome shotgun sequencing, provides a first overview of the cave ice gesting that not only animal-associated bacterial lineages but also glacier-derived bacteria could make specific microbiome structural and functional variability that could be used for assessing the impact of climatic and associations with ice worms. In the glacier stonefly, animal-gut-specific bacterial lineages such as environmental changes recorded up to at least 10,000 years in this alpine icy habitat. Lachnospiraceae and Porphyromonadaceae were the predominant members of the gut bacterial consortium. FISH analysis revealed that these gut-specific bacterial lineages were densely colonized in the gut of the This study was financially supported by ANCS-UEFISCDI PN-II-ID-PCE-2011-3-0742 grant and H2020 Era- glacier stoneflies. Net-LAC ELAC2014/DCC0178 Joint Program. These results suggest that there are unique niches inside the gut or body surface of glacier invertebrates (e.g. nutrient concentration, oxygen availability, and host’s immune system), which are different from those on the glacier surfaces.

Conclusion: Structures of bacterial communities associated with the glacier invertebrates are distinct from those on the glacier surfaces. These results imply that glacier invertebrates and their associated bacteria occupy the unique niches in the glacier environments. We are currently performing the metagenomic analyses of the gut microbiota of glacier stoneflies to investigate the metabolic capability of them. I will include preliminary results of these analyses.

61 Poster Abstracts Poster Abstracts

[P11] ESTABLISHMENT OF FUNCTIONAL MICROBIAL COMMUNITIES AND NUTRIENT CYCLING [P12] A COMPUTATIONAL PIPELINE FOR TAXON, GENE AND ALLELIC ANALYSIS OF MICROBIAL PROCESSES DURING ECOSYSTEM DEVELOPMENT METAGENOMES

Silvia Gschwendtner1, Jens Boy2, Roberto Godoy3 Gilda Varliero1, Joshua Blacker2, Alex Anesio3, Liane Benning4, Gary Barker5 1 Helmholtz Zentrum München, Neuherberg, Germany 1 School of Biological Sciences, University of Bristol, Bristol, United Kingdom 2 Leibniz Universität Hannover 2 School of Earth & Environment, University of Leeds, Leeds, United Kingdom 3 Universidad Austral de Chile 3 School of Geographical Sciences, University of Bristol, Bristol, United Kingdom 4 German Research Centre for Geosciences, Helmholtz Centre Potsdam, Potsdam, Germany Aim: Natural and anthropogenic activities lead permanently to the exposition of new terrain for soil develop- 5 University of Bristol, Bristol, United Kingdom ment. In the context of soil formation, which is driven by a complex network of biological as well as physical and chemical processes, the role of microorganisms is of high interest as they are responsible for most bio- Aim: Characterising microbial communities through analysis of their nucleic acid content allows us to gain an logical transformations and the establishment of carbon (C), nitrogen (N) and other nutrient pools. Thus, soil understanding of the processes they perform, without restricting our attention to cultivable taxa. We have microbes drive the transformation from barren substrate to nutrient-enriched soil and facilitate subsequent now reached the point where the increased read-length and accuracy of Illumina sequencing allows us to colonization by plant communities. When investigating the establishment of nutrient turnover processes and produce millions of shotgun metagenome sequences from tens of samples in a single multiplexed run. This the underlying functional microbial communities in the initial steps of soil formation, chronosequences of allows us to ask not only “what microbes are present in our samples?” – addressable with cheaper 16S-ampli- different soil development stages like forefields of receding glaciers are ideal study sites. Although most initial con sequencing, but also “what metabolic capabilities do they have?” Most importantly we can ask, “How do ecosystems are characterized by nutrient shortage, especially N, microbial N demands are often covered by biotic and abiotic factors of interest affect the relative abundance of taxa and their corresponding metabolic aerial N deposition, leading to a highly active heterotrophic community of mineralizing microbes feeding on repertoire?” There are many excellent tools for the visualisation of such complex datasets, with MEGAN and ancient and allochthonous carbon. In contrast to other terrestrial habitats, Antarctic ecosystems lack this MG-RAST focussing on the taxonomic and high-level (gene ontology) functional annotation of individual shot- continuous N deposition (except in areas in proximity of bird colonies), which makes them an ideal playground gun sequences. More recently the JGI’s Elviz 2.0 tool has provided an excellent visual browser for assembled to study the establishment of nutrient cycles and their microbial key players without aerial N input. contigs. The existing pipelines are not, however, designed to perform gene-wise statistically-based analyses of microbial communities. Method: To overcome spatial heterogeneity, different soil chronosequences of the maritime Antarctic defined by different deglaciation schemes (directly as uncovered substrate or indirectly as raised Palaeobeaches) Method: Using an appropriate statistical framework, incorporating replicates and environmental covariates along succession gradients are investigated. Using next-generation sequencing and real-time PCR, the esta- where appropriate, we can ask questions such as “what genes are differentially abundant between recent blishment and evolution of microbial communities and their role in nutrient transformation during ecosystem and older exposed forefields after glacial retreat?” We have developed a pipeline to efficiently annotate development could be followed. assembled metagenome contigs using DIAMOND blast, to map raw shotgun reads back their identified gene models and to identify significant differential gene abundance using a flexible General Linear Model approach, Results / Discussion: We observed that (1) different steps of nutrient cycling processes dominated different implemented in R and PERL. This approach relies on assembling all samples to create a common reference soil development stages, (2) microbial communities differed significantly between different soil chronose- metagenome on which all sequences can be mapped and quantified. quences and development stages and (3) bacteria and fungi showed clear succession trends. Detailed results on the establishment of nutrient turnover and microbial diversity pattern will be presented at the conference. Results / Discussion: Our pipeline is able to identify differential abundance of Single Nucleotide Polymorphis- ms (SNPs) between sample factor levels – a hitherto unexplored source of variation. In order to demonstrate the utility of this approach, we present an analysis of a dataset of 20 metagenomes collected along a glacial forefield chronosequence from Svalbard. We are also able to identify differentially abundant taxa at phylogenetic levels from phylum to species and individual genes.

Conclusion: This approach provides new insights into differential gene and allelic abundance due to factors of interest to polar microbiologists.

63 Poster Abstracts Poster Abstracts

[P13] GEOCHEMICAL AND MICROBIOLOGICAL GRADIENTS ALONG AN ARCTIC [P14] LIPOPOLYSACCHARIDE MOLECULAR STRUCTURE FROM THE COLD-ADAPTED SHEWANELLA CHRONOSEQUENCE SP. HM13

Lucie Malard1, Robin Wojcik2, Johanna Donhauser3, Stine Holm2, Alexandra Holland4, Beat Frey3, Dirk Angela Casillo1, Maria Michela Corsaro2, Marcello Ziaco2, Jun Kawamoto3, Tatsuo Kurihara3, Chen Chen3 Wagner2, David Pearce5, Alexandre Anesio6, Liane Benning7 1 Department of Chemical Sciences, Federico II University, Naples, Italy 1 Northumbria University, Newcastle Upon Tyne, United Kingdom 2 Federico II University of Naples , Department of Chemical Sciences, Naples, Italy 2 Gfz, German Research Center for Geosciences, Potsdam, Germany 3 University of Kyoto, Japan 3 Swiss Federal Research Institute Wsl, Birmensdorf, Switzerland 4 University of Bristol, Bristol, United Kingdom Aim: The cryosphere, covering about one-fifth of the surface of the Earth, comprises several components: 5 University of Northumbria at Newcastle, Newcastle Upon Tyne, United Kingdom snow, river and lake ice, sea ice, ice sheets, ice shelves, glaciers and ice caps, and frozen ground which exist, 6 School of Geographical Sciences, University of Bristol, Bristol, United Kingdom both on land and beneath the oceans.[1] All these habitats, combining the low temperature and the low liquid 7 Gfz, German Research Centre for Geosciences, Free University of Berlin, Germany water activity, are challenging for all the forms of life.[2] Cold-adapted organisms have successfully evolved adaptation mechanisms to overcome key barriers related to the survival in cold environments. This ability Glaciers and ice sheets are increasingly retreating in response to climate change. As glaciers retreat, recently implies the up-regolation of cold shock enzymes and the production of extracellular polymeric substances. deglaciated bedrock is exposed and thus, affected by weathering and colonized by pioneer microorganisms. In addition, for cold-adaptation mechanisms the macromolecules belonging to the external layer are funda- Therefore, glacier forefields provide unique environments to study the initial and successional geochemical mental. Among these, the lipopolysaccharides (LPSs), which constitute the 75% of Gram-negative bacteria and microbiological stages of soil formation. outer membrane, may contribute to the adaptation. Lipopolysaccharides are heat-stable complex amphiphilic macromolecules indispensable for the bacterial growth, viability and for the correct assembly of the external Aim: Investigate the relationship between geochemical and microbiological processes driving soil develop- membrane. The LPSs, through their negatively charged groups, create a highly ordered structure, stabilized by ment along a recently deglaciated Arctic chronosequence. electrostatic interactions with divalent cations. The LPS is composed of three different domains: a hydrophilic O-specific polysaccharide (O-chain), and a core oligosaccharide that in turn is covalently linked to the third do- Method: In this study, we sampled 9 sites during the winter season, representing 3 different developmental main, the lipid A. It has been reported that unsaturated fatty acids belonging to both phospholipids and LPSs stages along a chronosequence in the proglacial area of Longyearbreen, Svalbard. The chemical, mineralogical are responsible of the fluidity membrane enhancement when bacteria thrive at low temperature. [3] In this and isotopic composition of the different size fraction of the samples were determined using X-ray fluorescen- communication, the molecular characterization of LPSs from the cold-adaptedShewanella sp. HM13 isolated ce, X-ray diffraction and mass spectroscopy elemental analyses. Nutrient composition analyses were carried from fish intestine is reported. using a Gallery Plus Automated Photometric Analyser. Microbial communities (both Bacteria and Archaea) were quantified using qPCR and sequenced with Illumina MiSeq. Method: Cold adapted bacteria Shewanella sp. HM13 were grown in LB medium at 4°C. Lipopolysaccharides were extracted by the phenol/chloroform/light petroleum (PCP) method and analyzed by SDS-PAGE. The Results / Discussion: Geochemical analyses showed that soil particle size as well as conductivity and pH -de monosaccharides composition was performed by GC-MS of the acetylated methyl glycosides. The LPS was creased with age (e.g. pH/conductivity were 8.8 and 380 mS.cm-1 in ‘young’ samples but 7.4 and 86 mS.cm-1 deacylated by alkaline treatment. The obtained product was characterized by Mass Spectrometry and NMR in the ‘older’ samples). Nutrients measured included nitrate and nitrite, which were below detection levels, spectroscopy. ammonia (8-67ppb) and phosphate (0-196ppb). Nutrients did not present any detectable patterns of variation with soil age. Bacterial gene copy numbers increased 1000-fold from soils in the youngest developmental Results/Discussion: The SDS-PAGE revealed that the LPS lacks of the O-chain portion (rough-LPS). The sugar stages to intermediate stages. Surprisingly, the highest abundance was recorded in intermediate stages and composition was obtained by GC–MS and revealed the occurrence glucose (Glc), 2-deoxy-2-amino-glucose did not increase further in older stages of development. Preliminary sequencing analyses showed a variation (GlcN), heptose (Hep), and 3-deoxy-manno-oct-2-ulopyranosonic acid (Kdo). The LPS was treated with hydrazi- in microbial communities along the chronosequence. Despite Proteobacteria dominating communities at all ne, and then with KOH, obtaining the totally deacylated oligosaccharide. The proton NMR spectrum confir- developmental stages, microbial communities of young soils were different from older soils.Bacteroidetes med the sugar composition. decreased in abundance with increasing distance to the glacier while Actinobacteria increased in abundance following the same gradient. Conclusion: Although only few LPS structures from cold-adapted bacteria have been characterized, [4-8] an interesting common feature is the production of rough lipopolysaccharides. Preliminary data for Shewanella sp. Conclusion: Linking geochemical parameters with microbial community structure was an essential element HM13 LPS showed the presence of glucose, heptose, Kdo and GlcN. The characterization of other LPS structu- of this study. From preliminary results, we can observe shifts in microbial communities and geochemical res from cold-adapted bacteria can shed light on the interaction between the cell and the environment. gradients along the chronosequence. Further analyses will assess the distribution pattern of OTUs across sites and identify functional groups that may be associated with specific geochemical conditions. The combination References of geochemical and microbiological analyses will inform on the processes involved in soil formation once glaciers retreat. The carbon sink associated with weathering in forefields may provide negative feedbacks on the [1] Vaughan D.G., et al. Observations: Cryosphere.2013 pp. 317-382. climate, particularly since glaciers are expected to retreat at increasing rates in the future. Understanding the [2] Casanueva A. et al., Trends Microbiol 2010 18:374-381. factors involved in soil development along with the microbial communities and functional groups present may [3] De Maayer et al., EMBO reports 2014 15(5): 508-517. inform on the potential impact of deglaciation on carbon dynamics. [4] Corsaro M.M. et al., Eur. J. Biochem. 2001 268: 5092-5097. [5] Corsaro M.M. et al., Chemistry 2008 14: 9368-9376. [6] Carillo S. et al., Chemistry 2011 17: 7053-7060. [7] Carillo S. et al., Eur J Org Chem 2013 18: 3771-3779. [8] Casillo A. et al., Mar. Drugs 2015 13: 4539-4555.

65 Poster Abstracts Poster Abstracts

[P15] SYMBIOTIC NITROGEN FIXATION IN LICHENS AND BRYOPHYTES IN A WARMING ARCTIC [P16] THE FUNCTIONAL PROFILES OF ENDOPHYTIC BACTERIA ASSOCIATED WITH ARCTO-ALPINE PLANT: OXYRIA DIGYNA Ingeborg Klarenberg1, Oddur Vilhemsson1 1 2 1 1 University of Akureyri (Iceland), University of Iceland, Akureyri, Iceland Cindy Given , Elina Häikiö , Riitta Nissinen 1 University of Jyväskylä, Dept Biol Env Sci, Jyväskylä, Finland Aim: Biological nitrogen fixation is an important process for nitrogen availability in nitrogen limited Arctic eco- 2 University of Eastern Finland, Dept Env Biol Sci, Kuopio, Finland systems. Bacteria (cyanobacteria, but potentially also other taxa) associated with lichens and bryophytes are important contributors to nitrogen fixation, especially in arctic environments in which lichens and bryophytes Aim: Plants in arctic biome have to face many challenges e.g. short and cold growing season, water stress and are highly abundant. Lichens are generally described as a mutualistic association of a fungus and an alga and/ low nutrient level in soils. Endophytic bacteria are known to associate with plants in all climates and promote or a cyanobacterium. However, lichens are also known to harbor species-specific bacterial communities which plant growth via e.g. biological nitrogen fixation, and phosphate mineralization. However, relatively little is are typically dominated by Proteobacteria. Among the potential functional roles of these lichen-associated known about the endophytic bacteria in cold climates. The conditions for aboveground and belowground bacteria are biopolymer hydrolytic activity, inorganic phosphate mobilization and nitrogen fixation. In the light plant tissues in cold climates can differ considerably. In such manner, we would expect different endophytes of climate change and the effect on Arctic ecosystems, the question rises what the consequence is of increa- and different functions are at play in different tissues. In this study we wanted to address the putative differen- sing temperatures on symbiotic nitrogen fixation with lichens and bryophytes. ces in the functional profiles between leaf and root endophytic communities of an arctic pioneer plant species Oxyria digyna (mountain sorrel) and between bait- and wild- plant bacterial communities. The main aim of the present study, which forms a part of the MicroArctic network on the microbial ecology of the warming Arctic, is to characterize and compare the composition and nitrogen-fixing activities of lichen- Method: The micropropagated plants with minimal bacterial load (referred to as bait plant) were potted in and bryophyte-associated microbiotas differentially impacted by a warming climate. net pots filled with sterile sand in Kuopio, Central Finland (62oN) and after acclimation were transported to Kilpisjärvi, North-western Finland (69oN), and planted in native soil in the tundra vegetation zone in fell Jehkas Method: In this study, we compare lichen- and moss-associated nitrogen fixation inside and outside open in July 2013. Plants were harvested in August, together with wild O. digyna (referred to as wild plant) growing top chambers in Iceland. Nitrogen fixation rates are measured using acetylene reduction assays. Microbial adjacent to the plots. The endophytic bacteria were isolated from leaves and roots and identified by 16S rRNA communities are assessed by taxonomic analysis of MiSeq libraries of 16S-targeted amplicons. Quantitative sequencing before characterized for their ability to hydrolyze chitin, starch, and cellulose, solubilize organic reverse transcription polymerase chain reaction (RT-qPCR) is used to determine the ratios between molyb- and inorganic phosphate and nitrogen fixation. Additionally, their growth at three temperatures (5°C, 20°C, denum nitrogenase (nif) and vanadium-dependent nitrogenase (vnf) gene expression. In addition, nitrogen and 37°C) was tested. fixation capability of selected isolates is tested in culture-based experiments. Results / Discussion: In total, 126 unique endophytic bacterial isolates were obtained. Several genera showed Results / Discussion: The lichen-associated microbiomes are strongly dominated by Proteobacteria, with tissue-specificity e.g.Sphingomonas sp. was detected only in leaf samples, while Flavobacterium sp. was isola- members of the orders Rhizobiales, Sphingomonadales and Burkholderiales particularly prominent. Changes ted only from root samples. Interestingly, the majority of the isolates, especially from wild plants, were closely in relative abundance of individual taxa when comparing open top chamber lichens to those from outside the related to bacterial isolates from other cold environments such as other cold-adapted plants, arctic and alpine chambers are expected to reflect the different living conditions expected in the warming Arctic. Nitrogenase soils, and glaciers, indicating a presence of group of plant-associated bacteria endemic to cold climates. expression levels, and quantitative acetylene reduction data will further support changes in the overall function and importance of the endolichenic microbiota. Functional profiles and their affiliation with different tissues of bacterial isolates from wild plants differed from those from bait plants. For example, the ability to fix atmospheric nitrogen was more prominent among Conclusion: The present study will improve our understanding of the lichen- and bryophyte-associated micro- leaf isolates from wild plants. In bait plants, however, N-fixation was more common among root isolates. This biome, and elucidate how temperature rise is affecting lichen and bryophyte associated bacterial communiti- shows that both plants have communities with this ability but the communities in the bait plants are in dif- es and their relevance for the nitrogen cycle in the Arctic. ferent tissues than in wild plants. Possible explanation is that bait plants acquired at least some diazotrophic bacteria from rhizosphere soil after being planted in the field and that the plant colonization is still in progress.

All isolates grew well at 20°C. Interestingly, while all bait plant isolates were able to grow well at 37°C, only 23% of the wild plant isolates could. In contrast, 85% of the wild plant isolates grew well at 4°C compared to 55% of bait plant isolates, suggesting that the endophytic bacteria in bait plants were adapted to warmer temperatures, and were likely acquired from the environment in Kuopio where the plants were acclimated. Importantly, these resident endophytes were not replaced in the field.

Conclusion: The difference in the functional profiles between bait and wild plant isolates indicates that bait plants acquired the endophytic bacterial communities from a different source i.e. air or water while the plants were in Kuopio. Our previous work on the succession of endophytic bacterial community had shown the increasing of similarity in the community compositions from control plant to bait plant to similar to wild plant type communities. When combining these two results, we can say that the endophytic bacterial communities are resistant to the changing of community members.

67 Poster Abstracts Poster Abstracts

[P17] ABUNDANCE AND DIVERSITY OF POTENTIALLY PATHOGENIC BACTERIA FROM ARCTIC [P18] WARMING AND REDUCTION OF PRECIPITATIONS AFFECT THE MICROBIOME OF RECENTLY ENVIRONMENTS AND THE RISKS THEY POSE DEGLACIATED SOILS IN THE SWISS ALPS

Diana Mogrovejo1, Florian Brill2, Nina Gunde-Cimerman3 Aline Frossard1, Johanna Donhauser1, Pascal Niklaus2, Thomas Rime1, Beat Frey1 1 University of Potsdam, Hamburg, Germany 1 Swiss Federal Research Institute Wsl, Birmensdorf, Switzerland 2 Dr. Brill + Partner, GmbH, Germany 2 University of Zürich, Switzerland 3 University of Ljubljana, Slovenia Aim: The impact of climate change is particularly strong in Alpine regions, causing potential important ecolo- Aim: The aim of this project is to determine the abundance and diversity of potentially pathogenic bacteria in gical and socio-economic consequences. The glacier retreat is one of the most visible effect of the increase of warming Arctic environments and what are the risks they pose. global temperature, leaving behind large areas of a barren landscape, physically and ecologically unstable. In the absence of vegetation, the soil microbial communities, constituted of about 10% by cyanobacteria and- al Method: Snow and sea water samples from Svalbard, Norway and Akureyri, Iceland have been taken so far. In gae, is especially important for initial soil formation and ecosystem functioning in this deglaciated terrain. The order to estimate the abundance/diversity of potentially pathogenic bacteria, the samples have been cultured microbial communities inhabiting these soils were found to be directly affected by variation of soil tempera- in several minimal media (solid and liquid) with different concentrations and incubated at different temperature and moisture. However, little is known on the impact of climate change on the diversity and functions of tures to promote the isolation of psychrotolerant and mesophilic microorganisms. microbial communities in these newly exposed barren soils, especially from in situ experiments in the Alpine environment. In order to determine the risk posed by the isolates, antimicrobial resistance assays are performed with the isolates. Method: A long-term field experiment was set-up in the Damma glacier forefield in the central Alps (Switzer- land), where 4 open-top chambers (OTCs) and 4 roofed plots (RPs) simulating an increase of temperature or a Metagenomic DNA has been extracted to analyze the community’s diversity. Several analyses for pathogenici- reduction of precipitation, respectively. Soils beside each open-top chamber was also monitored and used as ty factors and antimicrobial resistance genes will be carried out too. a control.

The results of each sampling site and sample type are being compared to draw conclusions on the diversity Results / Discussion: Data collected over a 3 consecutive summer seasons showed an average increase of and potential for spreading of the pathogenic microorganisms. temperature of 1.3°C in the OTCs and a reduction of soil moisture of 10% in the roofed plots. Net ecosystem production was clearly lower in the OTCs compared to the control plots, due to a lower gross primary pro- Expected Results: Several isolates have been obtained, some of which are capable of growing in a wide range duction and higher soil microbial respiration. Measurements of greenhouse gases showed an increase of CH4 of temperatures (5-37°C). Several isolates present antagonistic (suppressive) behaviors, are pigment-produ- emissions from the soil in the OTCs, while the soil effluxes of N2O were larger in the RPs. Functional genes as- cing and/or present several degrees of resistance against antimicrobials. sociated with denitrification were decreased in the RPs, but increased in the OTCs. Contrastingly, no significant changes were detected neither in the bacterial nor in the fungal community structure among the treatments. The community composition goes in accordance with what has been reported for cold environments in the literature, with the Proteobacteria being present in the largest proportion. Conclusion: All together our findings demonstrate the high sensibility of the microbiome in recently deglaciated soils, responding to climate change. This experiment also highlights the importance of long-term in situ Patterns have been extrapolated from the same type of sample from different locations. field experiments to assess the effects of climate change on the soil ecosystem functioning.

Discussion/Conclusion: A considerable number of research efforts have been oriented towards the determi- nation of the diversity of the microflora in extreme, cold environments. Early on, these studies used culturing and isolation techniques to assess such diversity. Nowadays, metagenomic approaches are more commonly used and continue to provide useful information about the bacterial communities and their interactions. As a result, psychrophilic organisms and communities have proven to be not only abundant but also incredibly diverse. It is worth noticing, however, that in spite of the great interest for the study of bacteria in cold environments, the research which specifically studies their pathogenicity is rather uncommon.

Bacteria inhabiting cold environments have to survive in adverse environmental conditions and require specific strategies to achieve a competitive advantage. For this reason, it is believed that the occurrence of antibiotic resistance among bacteria that has minimal or no exposure to antibiotics is probably intrinsic or selected due to the antagonistic interactions among bacteria. In fact, it has been found that bacteria are resistant to antibiotics despite the absence of selective pressure or contact with antibiotics. The risk of these bacteria being released into the environment, and transported to other regions of the globe, is a realistic possibility that must be studied.

All in all, this work aims at encouraging further research on the assessment of the diversity and risks posed by these organisms in the Arctic region as well as providing insight into the possibility to use cold-adapted bacteria as a new source of industrially exploitable antibiotics.

69 Poster Abstracts Poster Abstracts

[P19] VEGETATION CHANGES ARISING FROM GRAZING ALTERS THE SOC COMPOSITION, THE References: MICROBIOTA AND ITS ACTIVITY IN HIGH-ARCTIC PEATLANDS 1. Ims, R. A., Jepsen, J. U., Stien, A. & Yoccoz, N. G.Science Plan for COAT: Climate Ecological Observatory for Arctic Tundra. (Fram Centre by the University of Tromsø, 2013). Kathrin Bender1, Mette M. Svenning1, Julia Schückel2, Susanne Liebner3, Alexander T. Tveit1 2. Kuijper, D. P. J. Intensive grazing by Barnacle geese depletes High Arctic seed bank. 1 et al. Can. J. Bot. Department of Arctic and Marine Biology, Uit The Arctic University of Norway, Tromsø, Norway 84, 995–1004 (2006). 2 Department of Plant and Environmental Sciences, Section for Plant Glycobiology, University of Copenhagen 3 Section of Geomicrobioloy, Gfz German Research Center for Geosciences, Potsdam, Germany 3. Sjögersten, S., van der Wal, R., Loonen, M. J. J. E. & Woodin, S. J. Recovery of ecosystem carbon fluxes and storage from herbivory. Biogeochemistry 106, 357–370 (2011). Aim: Arctic terrestrial peatlands store 30-40 % of the world`s soil organic carbon (SOC), the fate of which is determined by the balance between plant growth, herbivore grazing and microbial decomposition. Barnacle 4. Sarkar, P., Bosneaga, E. & Auer, M. Plant cell walls throughout evolution: towards a molecular under- geese and reindeer grazing causes a shift in the vegetation of Arctic peatlands1,2, from species-rich to moss standing of their design principles. J. Exp. Bot. 60, 3615–35 (2009). dominated3. Mosses and vascular plants possesses different ratios of cell wall polysaccharides, proteins and phenolic polymers4plants typically remain in one location utilizing sunlight for the synthesis of carbohydrates, which serve as their sole source of energy as well as building blocks of a protective extracellular matrix, called the cell wall. During the course of evolution, plants have repeatedly adapted to their respective niche, which is reflected in the changes of their body plan and the specific design of cell walls. Cell walls not only changed throughout evolution but also are constantly remodelled and reconstructed during the development of an individual plant, and in response to environmental stress or pathogen attacks. Carbohydrate-rich cell walls display complex designs, which together with the presence of phenolic polymers constitutes a barrier for microbes, fungi, and animals. Throughout evolution microbes have co-evolved strategies for efficient breakdown of cell walls. Our current understanding of cell walls and their evolutionary changes are limited as our knowledge is mainly derived from biochemical and genetic studies, complemented by a few targeted yet very informa- tive imaging studies. Comprehensive plant cell wall models will aid in the re-design of plant cell walls for the purpose of commercially viable lignocellulosic biofuel production as well as for the timber, textile, and paper industries. Such knowledge will also be of great interest in the context of agriculture and to plant biologists in general. It is expected that detailed plant cell wall models will require integrated correlative multimodal, multiscale imaging and modelling approaches, which are currently underway, but the molecular composition of the Arctic peatland flora is not well described. Thus, grazing alters the input of organic matter and nutrients to the soil microbes, but the extent of the alteration and the effect on the soil microbes is unknown.

Method: The fieldwork was carried out in a High-Arctic peatland, Ny-Ålesund, Svalbard (78°55’N, 11°56’E) in August 2016. Experimental sites had been maintained for 18 years by fences prohibiting grazing by Barnacle geese. Heavily grazed control sites were located next to the experimental sites. We observed higher abundances of vascular plants at the fenced sites than in the control sites as reported previously3. In total, we collected four biological replicates of soil from the fenced areas and four replicates from the grazed controls. We sampled the upper soil layer at 2cm depth. The polysaccharide composition of the soil matrix was determined using Comprehensive Microarray Polymer Profiling (CoMPP). Extracellular enzyme activities for polysaccharide degradation was measured using GlycoSpotTM. The microbial community composition, functional potential and gene transcription for polysaccharide degradation was studied using shotgun metagenomics and metatranscriptomics, respectively.

Results / Discussion: Our results show that the vegetation composition corresponds to the soil content of different polysaccharides as the amounts of xylan, arabinoxylan and xyloglucans were higher in the fenced sites richer in vascular plants. Metagenomic and metatranscriptomic analyses showed a substantial increase in the abundance and activity of the polysaccharide degrading microbiota in the fenced sites. Correspondingly, the potential activity of extracellular enzymes for the degradation of cell wall polymers were higher in the fenced sites. However, we observed no changes in the composition of the prokaryotic microbiota, but we identified significantly higher abundance of fungi in the fenced site.

Conclusion: We show that vegetation changes arising from herbivore grazing alters the composition, size, gene transcription and activity of the polysaccharide degrading microbial community. These animal-plant-mi- crobe interactions influence the role of Arctic peatlands as either sources or sinks for greenhouse gases in the atmosphere.

71 Poster Abstracts Poster Abstracts

[P20] OPTIMIZATION OF AIR SAMPLING EFFICIENCY AT SUBZERO TEMPERATURES APPLYING [P21] STANDARDIZED PIPELINE FOR FULL RNA NO PCR BIASED ANALYSIS OF THE MICROBIAL LIQUID IMPINGING AND MEMBRANE FILTRATION POPULATIONS IN ARCTIC ENVIRONMENT

Nora Els1, Birgit Sattler1, Marina Fernández-Delgado Juárez2, María Gómez-Brandón2, Arwyn Edwards3 Muhammad Zohaib Anwar1, Carsten Suhr Jacobsen2, Toke Bang-Andreasen3, Anders Lanzen4 1 University of Innsbruck, Institute of Ecology, Austrian Polar Research Institute, Innsbruck, Austria 1 Mbioinform Aps, Aarhus University,, Copenhagen, Denmark 2 University of Innsbruck, Institute of Microbiology, Austria 2 Dep.of Environmental Science, Au, 4. Center for Permafrost (Cenperm), University of Copenhagen, Roskilde, Denmark 3 Aberystwyth University, Institute of Biological, Rural and Environmental Sciences, UK 3 Aarhus University, Roskilde, Denmark 4 Neiker-Tecnalia, Bilbao, Spain Aim: Aerial input is considered a major inoculation and nutrient source to diverse microbial communities of ice and snow surfaces. Yet, deposition and colonization processes are not totally understood or quantified. Aim: The Arctic plays a key role in Earth’s climate system and is a geographical area of growing strategic Recent developments of mobile, high volume air sampling methods enable insights in diversity, abundance importance for European policy. It bears great potential to identify the community structure and functional and activity of airborne microbes present in ambient air at remote places. profile of microbial communities that are involved in changing weather in the warming Arctic. Studying the Arctic requires meta-omic approaches on high throughput sequencing technologies which produce gigantic However, in pronounced cold and dry environments like alpine and polar regions, constraining factors like amount of raw data. To date, many open source standalone tools are built for different exercises like SortMeR- freezing, sublimation and evaporation of sample medium or filter clogging and desiccation may considerably NA [1], MaxBin [2], Diamond [3] and Trinity [4]. A pipeline MetaTrans [5] which includes multiple steps from detract sampling yields. Additionally, the lack of consistent sampling protocols hampers the comparability quality filtering, separation of types of RNA and performing RNA-seq analyses on taxonomic and gene expres- between studies. sion using few of above mentioned tools is present. However, to date a thorough independent benchmark comparing state-of-the-art Metatranscriptomics analysis tools is lacking. Method: Here, we compare adaption strategies for air sampling at subzero temperatures for gelatine membrane filtration (Sartorius AirPort MD8) and liquid impinging (Bertin Coriolis µ) regarding sampling efficiency Method: Here, we present a benchmark where the most widely used tools are tested on complex, realistic and methodical impact on microbial abundance and diversity, culturability and productivity. data sets from Arctic and soil environment along with simulated communities with controlled differential expression. We here lean towards answering the long-standing questions like Binning or assembly of raw Special focus was brought to the improvement of liquid impinging results by application of a heat source at reads provide better resolution of functional profile? ii) Which databases to be used for reference? different heat levels, freezing point depression of sample medium and particle collection without impinging medium at different flow rates. Results / Discussion: Promising results are seen by applying the mentioned methodology on Permafrost soil and Danish forest soil. Results / Discussion: Flow rates of incoming air flows, choice of sampling media, total sampled volume, freezing or evaporation of medium impacted on the sampling success and vitality of organisms. However, the The functional annotations of the putative functional genes of these samples could be identified with more extent of effects varies highly between parameters. specialist level in the functional hierarchy.

It is not only sampling procedures which require a thorough evaluation but also the processing methodologies Conclusion: This study will provide a comprehensive comparison and will help the community to better un- such as bacterial cell counting. Large amounts of airborne aggregates impede a sound distinction between derstand the functional profile of Arctic. cells. Here, we demonstrate potential to improve filtration protocols by application of ultrasound treatment as well as chemical reduction of the surface tension.

Conclusion: The results imply a high potential for improvement of bioaerosol sampling yields in extreme environments contrasting several options to adapt sampling parameters and processing methodology as well as the need to address sampling objective and encountered environmental conditions.

High discrepancies in sampling efficiency and effects between sampling parameter modifications stress the importance to establish consistent sampling protocols.

73 Poster Abstracts Poster Abstracts

[P22] THE GEOCHEMISTRY OF SURFACE ICE ON THE GREENLAND ICE SHEET AND ITS EFFECT ON [P23] GREENLANDIC ENZYMES FOR BIOCATALYSIS OF PREBIOTIC OLIGOSACCHARIDES THE PRIMARY PRODUCTION OF MICROBES Mariane Schmidt Thøgersen 1, Morten Jepsen1, Peter Stougaard1 1 2 2 2 2 Alexandra Holland , Christopher Williamson , Fotis Sgouridis , Martyn Tranter , Alexandre Anesio 1 University of Copenhagen, Department of Plant and Environmental Sciences, Frederiksberg, Denmark 1 University of Bristol, Bristol, United Kingdom 2 School of Geographical Sciences, University of Bristol, Bristol, United Kingdom Aim: The aim of this study was to investigate bacteria isolated from cold (0-5°C) and warm (50-60°C) habitats in Greenland for their ability to produce enzymes with industrial potential and to characterize such enzymes. Aim: Microbial communities have recently been shown to play key roles in the bio-albedo of the Greenland Ice Sheet (GrIs) and consequently melt rates. As such, there is significant interest in understanding how these Method: Bacteria were collected from the ikaite columns in the Ikka Fjord, Southwest Greenland (<5°C, pH microbial communities survive and thrive in such harsh and oligotrophic conditions. Current knowledge gaps 10.4), and from hot springs in East Greenland (49-60°C, pH ~7) from 2001-2006. Strains were isolated on include the effect of nutrient limitation on the primary production of surface ice microbial communites, and R2agar media at pH 10, 5-15°C for the Ikka bacteria, and at pH 7, 50-55°C for the hot spring bacteria. All stra- the impact of microbial production on dissolved organic carbon (DOC) concentrations. ins were subsequently screened for enzymatic activities on modified R2agar using AZCL- (azurine crosslinked) or X- (5-Bromo-4-chloro-3-indolyl) linked substrates. Selected enzymes were expressed recombinantly in E. Method: This study sampled a small section of the GrIS surface, approximately 35km inland from the margin, coli and B. subtilisand purified enzymes were assayed using SDS-PAGE, TLC, and HPLC. throughout the 2016 melt season. We report nutrient [phosphate, ammonium, nitrite, nitrate, total phosphorus, and total nitrogen] and DOC concentrations. Sampling focused on five main habitats representative of Results / Discussion: Galacto-oligosaccharides (GOS) are sugar chains composed of the monosaccharide the supraglacial landscape, namely: surface ice with low, medium and high levels of visible particles, supragla- galactose attached to glucose [Galn-Glc, n=2-4] and are produced by a group of enzymes called glycoside cial stream water and cryoconite hole water. hydrolases (GHs) using lactose as a substrate. GOS have through several studies been established as prebiotics by stimulating growth of certain beneficial members of the gut microbiota affiliated to Bifidobacteria and 3- + Lactobacilli, while simultaneously reducing the adherence and growth of potentially pathogenic bacteria such Results / Discussion: Concentrations of inorganic nutrients ranged 0.5-3ppb for PO4 , 13-22ppb for NH4 , and 1 as Escherichia coli and Salmonella enterica serovar Typhimurium, hence preventing the production of toxic 0-9.5ppb for NO3 across the five representative habitats. In contrast, nutrients were found in higher concentrations in their respective dissolved organic phases with TP reaching 1.5-7ppb and TN reaching 8.5-250ppb. metabolites in the gut. Furthermore, GOS are not absorbed by the intestines and therefore cannot be utilized Concentrations of dissolved organic phosphorus (DOP) were found to be 2-3 times higher than inorganic by the host, making them popular low-calorie food ingredients and sweeteners. fractions, while close to 99% of nitrogen was found in the dissolved organic phase (DON). DOC concentrations ranged from 80ppb to as high as 7ppm. In this study, we identified and characterized a cold-active β-galactosidase (GH family 2) from the psychrophilic bacterium Alkalilactibacillus ikkensis isolated from an ikaite column in the Ikka Fjord in Southwest Green- Conclusion: High relative concentrations of DON, DOP, and DOC, provide strong evidence for efficient nutrient land. The ikaite columns are, with their interior pH of 10.4 and constant low temperature, the ideal place to cycling by microbial communities on the ice surface. Relatively low concentrations of DON, DOP and DOC isolate extremophilic bacteria with industrial potential. ThisA. ikkense β-galactosidase shows optimal activity in supraglacial stream water suggest that microbial habitats facilitate retention of such nutrients within the at 20 °C, but retains 60-65 % of its activity at 0-5 °C, making it an attractive enzyme for the dairy industry. ice surface, permitting their continual reuse and recycling. Hence, microbial processes increase the localised In addition to lactose hydrolysis, further potential applications include the production of lactose-free milk concentration of both nutrients and DOC in ice surface habitats on the GrIS. products at fridge-temperature and enzyme-based production of GOS with a degree of polymerization (DP)

up to DP5 [Gal4-Glc]. Cold-active enzymes such as the β-galactosidase described here are also attractive enzymes for use in fresh food products (e.g. milk) for which low temperatures are desirable in order to preserve both product quality and reduce energy consumption required during production. For the production of prebiotics for products with a longer shelf life such as milk powder for use in instant milk formula, heat-stable enzymes are desirable due to the increased solubility of lactose at elevated temperatures. Therefore, we also screened thermo-tolerant bacteria from hot springs in East Greenland for enzymes able to catalyze the formation of human milk oligosaccharides (HMOs) for use in milk formula. This resulted in the isolation of a thermostable α-L-fucosidase (GH family 29) from the bacterium Paenibacillus dendritiformis, which is able to hydrolyze α-L-fucoside bonds and catalyze the formation of trans-fucosylated oligosaccharides at 50-60 °C.

Conclusion: With this study, we have shown the application potential of two enzymes produced by bacteria isolated in Greenland: a cold-active β-galactosidase and a thermostable α-L-fucosidase, showing that bacteria from Greenland indeed have an extensive scientific and industrial potential due to the broad variety in physical and chemical conditions throughout the various habitats in the country, affecting the characteristics and properties of the bacteria and the bioactive compounds that they produce.

75 Poster Abstracts Poster Abstracts

[P24] BIOPROSPECTING FOR NOVEL ANTIMICROBIAL DRUGS FROM MICROBES IN GLACIAL [P25] MINING THE ARCTIC MICROBIAL METAGENOME FOR INDUSTRIALLY USEFUL COLD-ACTIVE ENVIRONMENTS ENZYMES

Aliyah Debbonaire1, Luis Mur1, Arwyn Edwards1 Melanie Hay1, Sara Rassner1, Andrew Mitchell1, Arwyn Edwards2 1 Aberystwyth University, Ceredigion, United Kingdom 1 Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, UK 2 Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, UK, United Kingdom Aim: Given the alarming levels of global antimicrobial resistance, there is an urgent need for novel antimicrobial drugs. This is a global problem and one of the main worries is the lack of new antibiotic drugs currently Aim: Arctic microorganisms are subject to a range of environmental stressors, such as permanently cold in development. One of the reasons for this absence is a need of untapped environments to exploit. Many temperatures, low nutrient availability, high desiccation, high summer UV exposure, and 24-hour winter dark- current antibiotic drugs currently in use have been isolated from soil environments, but these have now been ness. Various structural and metabolic adaptations to these stressors make them ideal organisms from which extensively mined, creating a need for a novel environment to exploit. Extreme ecosystems such as glaciers to base biotechnological tools (Cavicchioli et al., 2002). As climate change continues to disproportionately are a poorly developed resource for antimicrobial discovery. Glaciers make up ~10% of the Earth’s surface and affect the polar regions, environmental conditions will likely select for a different set of biological adaptations. contain diverse microbial life. Given the harsh conditions these microbes experience it is thought they may Therefore, the opportunity to discover the unique ways that life has evolved to withstand cold may be lost as produce stress response compounds which could possess antimicrobial properties. the world warms.

Method: The first phase of the research has involved establishing an optimised cultivation technique, by Arctic microorganisms require continued metabolic activity at close to freezing temperatures, and are there- conducting a large-scale growth experiment testing several treatments and their effect on over growth and fore an ideal resource from which to source industrially useful cold-active enzymes. Cold-active enzymes have diversity of growth. Samples were collected in August 2016 from Longyearbyen, Svalbard. These have been high catalytic activity at low temperatures and are therefore more energy efficient, cheaper, safer and more cultured in many different conditions e.g. temperatures, dilution factors, novel media, totalling inoculation environmentally sustainable than current chemical methods (Santiago et al., 2016). Additionally, because they and subculture of over 1200 culture plates. can be heat-inactivated, they remove the need for chemical inactivation or purification steps. Consequently, it has been estimated that up to 40% of the bulk chemical synthesis processes requiring environmentally dama- Results / Discussion: Results from the large-scale culture have been promising, with several pigmented ging substances and high energy inputs could be replaced by enzymatic catalysts by 2030 (Ferrer et al., 2016). morphotypes isolated for further study. For this, we have designed a high throughput approach to screen all isolates for activity. We will initially search for isolates with any bioactivity against key organisms:Escherichia Method: This study used a sequence-based metagenomic approach to screen seven metagenomes from coli, Staphylococcus aureus (MRSA), Pseudomonas aeruginosa (from cystic fibrosis patients) and Svalbard for genes encoding putative cold-active enzymes. Metagenomes were sequenced on an Illumina Mycobacterium smegmatis. Our pilot studies reveal isolates demonstrating antimicrobial activity against the MiSeq using paired end sequencing. Sequences were trimmed, based on quality and reads were assembled important human pathogen Pseudomonas aeruginosa. into contigs. Assembled sequence data were used to query specific enzyme sequence databases such as Car- bohydrate-Active Enzyme (CAZyme) (Cantarel et al., 2009), Lipase Engineering Database (Fischer and Pleiss, Conclusion: Now an optimised cultivation and high throughput antimicrobial activity screening assay has been 2003), the Laccase Engineering Database (Sirim et al., 2011), PeroxiBase (Passardi et al., 2007) and AromaDeg established, we are utilising previous bulk stocks of cryoconite collected from many diverse geographical loca- (Duarte et al., 2014). tions, including Sweden, Greenland and the Antarctic. These will be systematically explored using the methods described above and any isolates showing high levels of activity will be selected for downstream chemical Results / Discussion: The metagenomes, collected in Svalbard in 2013, ranged in size from 18,7 MB to 499,0 analysis to purify and identify the bioactive compounds. Purified compounds may undergo cytotoxic testing MB. All metagenomes contained sequences for numerous putative enzyme-encoding genes. Enzymes of inte- and further safety assessments to verify their potential as novel antimicrobial drugs. rest come from industrially relevant enzyme classes such as acylases, phosphatases, proteases, oxidoreducta- ses, glycosyl hydrolases and lipases/esterases. This work has already allowed the identification of a bottleneck in antimicrobial discovery: the time- consu ming nature of cultivation. Therefore, we are using metagenomic techniques in parallel to explore these -mi Conclusion: In addition to finding a number of candidate genes for further investigation, this study also provi- crobial communities and any potential bioactivity. We will mine genomic sequence data for novel biosynthetic des gene clusters that may be associated with antimicrobial activity. This will be complemented by activity based functional metagenomic screening using Fosmid vectors.

A combination of culture-dependent and culture independent methods are being used in our search for drug leads.

77 Poster Abstracts Poster Abstracts

[P26] HYPOGEOUS FUNGI AT THE UPPER TIMBER LINE - RECENT FINDINGS AND NEW SPECIES [P27] MOLECULAR DIVERSITY OF AMMONIA OXIDIZING ARCHAEAL ASSEMBLAGES IN AN ARCTIC POLAR FJORD Tine Grebenc1, Tina Unuk1, Marcelo Sulzbacher2, Sana Jabeen3, Abdul Nasir Khalid4, Mitko Karadelev5 1 2 1 Slovenian Forestry Institute, Ljubljana, Slovenia Kumari Richa , Punyasloke Bhadury 2 Universidade Federal de Santa Maria, Centro de Ciências Rurais, Departamento de Solos, Santa Maria Rs, Brazil 1 Stazione Zoologica Anton Dohrn, Naples, Italy 3 University of Education, Faisalabad Campus, Faisalabad, Pakistan 2 Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, India 4 Department of Botany, University of the Punjab, Lahore, Pakistan 5 Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss Cyril and Methodius University, Skopje, Macedonia Aim: Arctic ecosystem is a unique environment that can act as a proxy of climate change at global scale. The- refore, it is crucial to study elemental biogeochemical cycling, in particular nitrogen cycle from this environ- Hypogeous fungi (truffles s. l.) are traditionally known to occur mainly in the Mediterranean climates. In ment and the microbial groups that mediate these processes and ultimately contribute to climate patterns recent decade, the cultivation efforts and large-scale sampling activities disclosed that hypogeous fungi are globally. Crenarchaeota, an abundant and widely distributed group of archaea play an important role in the present in large areas in the mesic climates of the northern hemisphere. Shamekh et al (2013) were first to first step of nitrification (i.e. conversion of ammonia to nitrite), a key process in nitrogen cycle. They have prove that commercial truffles can be successfully cultivated also in the boreal zones. been increasingly recognized in Arctic region during recent years (Kalanetra et al., 2009; Sintes et al., 2013; Pednault et al., 2014; McCann et al., 2016). In this study, we investigated presence of ammonia oxidizing The upper timber lane was never of interest of commercial truffle hunters thus it remained understudied until archaeal assemblages in Kongsfjorden, a Norwegian Arctic fjord, during the late winter of 2010. The study site recently. The review study is focusing on several potential areas around the globe where hypogeous fungi, in is characterized by unique hydrological and geochemical fluxes with the union of temperate water of Atlantic particular true truffles (the genusTuber ) are expected to grow. Applying a purposive sampling approach, we and freezing water of Arctic Ocean, making it an ideal site for harbouring unique microbial community compo- have intensively investigated the areas with potential ectomycorrhiza vegetation and preferably on calcium sition. rich rock-bases in the SE central Alps, Dinarides (or. Dinaric Alps) and the part of the western Himalayan area. Hypogeous genera were recorded either as ectomycorrhiza or as sporocarps found by specially trained truffle Method: We employed PCR clone library and Sanger sequencing of ammonia monooxygenase gene subunit A hunting dogs. (amoA), a functional key gene involved in the oxidation of ammonia during nitrification, using archaeal specific amoA primers. The analysed areas were either covered with forest vegetation Fagus( sylvatica, Abies alba, Larix decidua, Pinus mugo, Cedrus deodara) or with shrub species (Salix herbacea, Alnus viridis, Betula nana, Results / Discussion: The preliminary results based on phylogenetic analyses of the archaealamo A sequences Dryas octopetala). All the species can form either solely ectomycorrhizal or combined with arbuscular mycor- generated during this study revealed that they are indigenous to the study site and different from previously rhiza. Among commercial truffle species onlyTuber aestivum was collected in organic soils developed at high published uncultured archaeal amoA sequences from other geographic locations, at the nucleotide level. altitude (> 1500 m a.s.l.) areas in Macedonia, covered with beech forest or mixed beech and silver fir forests (Grebenc et al., 2011). Also in the Dinaric Alps under similar vegetation but different ecology in Serbia a novel Conclusion: The sequence diversity was low, nevertheless the molecular detection of ammonia oxidizing true truffle speciesTuber petrophylum, a species closely related to T. melanosporum, was described (Milen- Crenarchaeal community in the polar fjord of Norwegian Arctic indicated their significance and potential role ković et al., 2015). Further collections were not thoroughly characterised not published. In particular, in SE in mediating global nitrogen cycle. Alps Hydnotrya cerebriformis appears to be a common species with Larix and Salix spp. Novel ectomycorrizae from the genus Tuber were retrieved also from Salix and Cedrus locations in W Himalayas, where one or more References: new species are foreseen, based on the morphotyping and DNA sequencing (Ilyas 2013; Jabeen and Khalid, 2014). A novel Tuber species with Salix spp. was also collected over the range of sites in Julian Alps in Slovenia, Kalanetra, K. M., Bano, N., & Hollibaugh, J. T. (2009). Ammonia‐oxidizing Archaea in the Arctic Ocean and geographically limited only to sites about 1200 m and up to the timber line. Then new species will be briefly Antarctic coastal waters. Environmental microbiology, 11(9), 2434-2445. described and supported with molecular data in the presentation. Other collections recorded infrequently or as solitary collections were alsoAlpova alpestris and Glomus sp. (as “sporocarp”) both under Alnus viridis Sintes, E., Bergauer, K., De Corte, D., Yokokawa, T., & Herndl, G. J. (2013). Archaeal amoA gene diversity points and annual ground vegetation. All unpublished collections are stored at the Herbarium and Mycoheca at the to distinct biogeography of ammonia‐oxidizing Crenarchaeota in the ocean. Environmental Slovenian Forestry Institute. microbiology, 15(5), 1647-1658.

Ilyas, S. (2013). Molecular investigations to characterize ectomycorrhizal fungal communities associated with Pedneault, E., Galand, P. E., Potvin, M., Tremblay, J. É., & Lovejoy, C. (2014). Archaeal amoA and ureC genes some deciduous trees of Galyat, Pakistan. PhD. Thesis, Department of Botany, University of Punjab, Lahore, and their transcriptional activity in the Arctic Ocean. Scientific reports, 4, 4661. Pakistan, pp. 1–150. McCann, C. M., Wade, M. J., Gray, N. D., Roberts, J. A., Hubert, C. R., & Graham, D. W. (2016). Microbial com- Jabeen S, Khalid AN 2014. Community structure of ectomycorrhizae associated with Salix spp. growing in two munities in a High Arctic polar desert landscape. Frontiers in microbiology, 7. different climatic regions of Pakistan. International Journal of Agriculture & Biology 16: 480–488.

Shamekh S, Grebenc T, Leisola M, Turunen, O 2013. The cultivation of oak seedlings inoculated withTuber aestivum Vittad. in the boreal region of Finland. Mycological Progress 13(2): 373-380.

Grebenc T, Kajevska I, Rusevska K, Karadelev M 2011. Hypogenous fungi diversity and their habitats in FYROM. In: Book of abstracts: XVI Congress of European Mycologists, Halkidiki, Porto Carras, 19-23/9/2011. Thessalo- niki, p. 265.

Milenković M, Grebenc T, Marković M, Ivančevič B 2015. Tuber petrophilum, a new truffle species from Serbia. Mycotaxon 130: 1141-1152.

79 Poster Abstracts Poster Abstracts

[P28] MULTIOMICS AND SINGLE-CELL GENOMICS ALONG A THAW GRADIENT OF ALASKAN [P29] THE EFFECT OF PERMAFROST THAW ON CIRCUM-ARCTIC METHANOGENIC COMMUNITIES PERMAFROST REVEAL MICROBIAL SURVIVAL STRATEGIES Stine Holm1, Susanne Liebner 1, Mattias Winkel1, Julia Magritz1, Christian Lehr2, Michael Fritz3, Jaroslav Obu4, Jenni Hultman1, Janet Jansson2 Hugues Lantuit3, Joanna Heslop5, Katey Walter Anthony5, Fabian Horn1, Christian Knoblauch6, Dirk Wagner1 1 University of Helsinki, Helsinki, Finland 1 Gfz German Research Centre for Geosciences, Section 5.3 Geomicrobiology,, Potsdam, Germany 2 Pnnl, United States 2 Leibniz-Centre for Agricultural Landscape Research (Zalf) , Müncheberg, Germany 3 Alfred Wegener Institute, Potsdam, Germany Aim: The fate of organic carbon reserves sequestered in permafrost is uncertain yet critically important for 4 University of Oslo, Department of Geosciences, Oslo, Norway addressing terrestrial feedbacks to climate change. With warming there is an increased probability of ther- 5 University of Alaska Fairbanks,Water and Environmental Research Center (Werc), Fairbanks, United States 6 mokarst formation, and an increase in greenhouse gas fluxes. However, we understand little of the underlying University of Hamburg, Institute of Soil Science, Hamburg, Germany microbial controls in permafrost soils. In high arctic permafrost landscapes, up to 1300 Gt of organic carbon are estimated to be stored. In the Method: We applied a variety of omics methods to study microbial communities, their functions and activity predicted thawing of permafrost, microbial degradation of previously frozen permafrost organic matter will lead to the production of the greenhouse gases (GHG) CO and CH . A study of 1200 days long term in permafrost soils collected from Alaska. 2 4 -1 incubation of permafrost showed CH4 production rates of up to 0.37 mg CH4 -C gdw . CH4 is a greenhouse gas ~25 times more potent than CO on a 100-year time horizon. Results / Discussion: Each zone (active layer, permafrost, and bog) had a unique complement of genes, tran- 2 scripts and proteins, indicative of differences in microbial community composition and their functional poten- The methane production has previously been shown to be constrained by the initial methanogenic commu- tials. The most abundant bacteria in permafrost soil, based on 16S rRNA gene sequences, were members of nity size, which itself is constrained by carbon density. Therefore, carbon density has been suggested a good phyla Chloroflexi, Proteobacteria and Actinobacteria. Similar phylogenetic distributions were observed in- me predictor for methanogenic abundance. tagenome and metatranscriptome datasets. Of the functions iron reduction emerged as a potential metabolic strategy employed by microbes in permafrost. By contrast, the active layer communities expressed genes and With previous studies focusing on the methane production rates, an understanding of the diversity and proteins involved in obtaining energy and nutrients from a diversity of aerobic and anaerobic processes and dynamics of methane producing microbial communities is needed. According to our current understanding, were equipped with functions for survival under freeze-thaw conditions. The thermokarst bog was dominated methanogenic archaea are the most relevant microorganisms able to produce methane under anaerobic by anaerobic methanogens that support high rates of methanogenesis. conditions.

We sequenced single cells from permafrost samples. The Chloroflexi SAG had genes for iron and nitrate Consequently, this study aims to map the archaeal community in circumarctic ecosystems and to provide reduction, and mechanisms to tolerate oxidative and redox stress. The Deltaproteobacteria SAG contained for insight into the changes of the community composition after permafrost thawing to answer the following nitrogen fixation, carbohydrate and sulfate transporters and osmoprotectants as well as pathways to tolerate questions: i) To what extent does the methanogenic community composition and diversity explain the poten- various stressors in freezing soil. tial methane production, both on the short and on the long term, and ii) which impact does the incubation temperature, the incubation time and the origin of permafrost deposits have on changes in the methanogenic Conclusion: These analyses reveal energy-yielding microbial processes and potential strategies for microbial community during thaw? survival in permafrost soils, and linkages between biogeochemical process rates and omics measurements. The multi-omics strategy demonstrated here enables better mechanistic understanding of the ecological Therefore, circum Arctic permafrost cores from Alaska, Canada and Siberia of both Holocene and Pleistocene strategies utilized by soil microbial communities in response to future climate change. origin were analyzed taking into account previously derived methane production rates during long term incubation over a time period of 7 months - 7 years. Methane production was measured by gas chromatography. The enumeration of methanogenic and bacterial gene copies was performed by quantitative PCR (qPCR). Selected samples, based on methane production, soil organic carbon (SOC) content and methanogenic abundance, were sequenced with specific archaeal and bacterial primers applying Illumina MiSeq sequencing.

To our knowledge, this is the first study that extends the analysis of permafrost incubations with the analysis of how microbial community composition, diversity and population size respond to short and long term

permafrost thawing. It thereby provides valuable input for a better projection on CH4 emissions from thawing permafrost.

81 Poster Abstracts Poster Abstracts

[P30] GENOMIC ANALYSES OF PSYCHROBACTER SPECIES FROM PERMAFROST [P31] IDENTIFYING CHANGES IN THE ACTIVE, DEAD, AND DORMANT MICROBIAL COMMUNITY STRUCTURES ACROSS A CHRONOSEQUENCE OF ANCIENT ALASKAN PERMAFROST Corien Bakermans1 1 1 1 1 The Pennsylvania State University, Altoona, United States Alex Burkert , Tara Mahendrarajah , Rachel Mackelprang 1 Csu Northridge, Northridge, United States Aim: As the Arctic warms and permafrost thaws, it is essential to examine the genetic basis of thermal adaptation and carbon metabolism of microorganisms that inhabit permafrost and are responsible for carbon Aim: Microbial communities within permafrost survive and reproduce for millennia despite extreme con- mineralization, transformation and release to the atmosphere. Here we present results from the comparison ditions such as water stress, subzero temperatures, high salinity, and low nutrient availability. However, we of the genome sequences of three Psychrobacter species isolated from Siberian permafrost and capable of do not fully understand how these organisms are able to survive. Previous studies have used metagenomic reproduction at low temperatures with 23 otherPsychrobacter genomes. and 16S rRNA gene sequencing to characterize community structure and functional potential in attempts to understand how these organisms adapt to the challenges associated with long-term survival in a permanently Results / Discussion: Principal component analysis (PCA) of the amino acid composition (average mol%) of frozen environment. However, freezing temperatures preserve DNA from dead organisms for extended peri- all protein coding genes revealed two clusters: marine and polar isolates with amino acid compositions more ods of time. Because metagenomic and 16S rRNA gene sequencing do not distinguish between active, dead, typical of psychrophiles (low P, more R than K) as separate from mesophilic host-associated isolates. A neigh- and dormant cells, it is difficult to determine which organisms are viable. This study focused on developing bor-joining tree of pairwise distances based on average nucleotide identity between genomes showed similar strategies to differentiate the active, dead, and dormant populations of low biomass permafrost microbial clustering of isolates. PCA of the relative abundance of genes in COG categories discerned two clusters of communities across a chronosequence (19 kyr, 27 kyr, and 33 kyr) of Pleistocene permafrost located near host-associated isolates (warm hosts such as human, seal, and tropical fish versus marine sponges from Antar- Fairbanks, Alaska. ctica) distinct from other Psychrobacter isolates (from marine, polar soil, or other frozen habitats). In addition, a 16S rRNA gene tree of 32 type strains of Psychrobacter species revealed some robust clusters associated Method: Fluorescence microscopy coupled with Live/Dead staining revealed that live cells exist in ancient with maximum growth temperature or habitat type. Initial assessment of paralogs revealed that permafrost permafrost and allowed us to observe how the number of total cells and the proportion of live cells changed isolates have more paralogs than other Psychrobacter species. Paralogs (multiple copies of a gene) may be a in increasingly ancient permafrost. Specifically, we saw a significantly higher number of cells in our interme- means to evolve enzymes that function at distinct temperatures. diate age samples, which could potentially be explained by the differing carbon chemistry and ice content of those samples. However, there were no significant differences between the cell counts from our youngest and Conclusion: These analyses suggest that habitat-specific signatures may exist; ongoing detailed analyses may oldest samples. To determine whether the active taxa differ across the three age groups, various strategies reveal specific factors (specific genes, HGT, paralogs, etc.) underlying these trends. have been developed to physically separate the active, dead, and dormant populations. Enrichment for endo- spores was done using treatments that enzymatically and physically lyse vegetative cells. In addition, inhibiting PCR amplification of DNA from dead cells was achieved using the nucleic acid stain, propidium monoazide, which is too large to pass through intact cell membranes but can pass through the ruptured membranes of dead cells. In the presence of bright light, it covalently cross-links DNA rendering it unable to be amplified by conventional PCR and thereby removing it from downstream analysis.

Results / Discussion: These combined protocols were performed on our low biomass permafrost chronosequence and the 16S rRNA gene of the active, dead, and dormant cell populations was sequenced to observe changes over geologic time. This approach allowed us to determine how community structure changed across the chronosequence. In addition, we identified changes in the relative abundance of dominant taxa within the active and dormant communities across the three age groups.

Conclusion: The strategies used in this study could be applied to a wide variety of low biomass environmental samples to distinguish between active, dead, and dormant members. Furthermore, identifying taxa enriched in older permafrost samples provides evidence as to whether the extremely cold environments, characteristic of permafrost, are selective for certain microbes over geologic timescales.

83 Poster Abstracts Poster Abstracts

[P32] SHIFTS IN MICROBIAL AND PLANT DIVERSITY ABOVE THAWING DISCONTINUOUS [P33] CARBON METABOLISM IN PLEISTOCENE PERMAFROST MICROBIAL COMMUNITIES PERMAFROST IN HIGH LATITUDE ECOTONES Tara Mahendrarajah1, Alexander Burkert2, Rachel Mackelprang2, Rakesh Mogul3 1 1 2 3 4 1 Robyn Barbato , Robert Jones , Thomas Douglas , John Anderson , Natalia Vinas , Karen Foley , Ruth 1 Csu Northridge, Northridge, United States 5 5 1 4 Nichols , Beth Shapiro , Steve Newman , Edward Perkins 2 California State University, Northridge, Northridge, United States 3 1 US Army Cold Regions Research and Engineering Laboratory, Hanover, United States California State Polytechnic University, Pomona, United States 2 US Army Cold Regions Research and Engineering Laboratory, Fairbanks, United States 3 US Army Geospatial Research Laboratory, Alexandria, United States Aim: Permafrost is gaining interest as a model for astrobiology. Since six of the other eight planets in our solar 4 US Army Environmental Laboratory, Vicksburg, United States system, as well as their moons, asteroids, and comets are permanently frozen, life on these celestial bodies 5 University of California- Santa Cruz, Santa Cruz, United States is most likely to be found in a subzero environment. On Earth, life can exist in permafrost for millennia and may act as an analogue reflecting potential inhabitants on extraterrestrial cryogenic bodies. Active microbial Aim: Climate projections for the 21st century forecast the potential for a pronounced warming in Arctic and life exists in even the most ancient permafrost, but we know little about the metabolic strategies utilized by sub-Arctic regions. Particularly, interior Alaska is expected to warm approximately 5°C by 2100, resulting in permafrost microbes that enable survival through millennia entrained in ice. Even in nutrient rich permafrost, significant changes to the landscape. The warmer temperatures and altered precipitation regime are expected most resources are sequestered away from the microorganisms by freezing conditions. to initiate changes in soil biogeochemical attributes in addition to biodiversity of plants and animals in these ecosystems. There is already evidence of permafrost thaw and vegetation shifts with a progression from fore- Method: To investigate community activity and metabolic strategies through geologic time with no influx sted ecotones to tussock tundra wetlands in interior Alaska and these ecosystems harbor complex associati- energy or new material we sampled from a chronosequence of Pleistocene permafrost ranging in age from ons between plants and soil microflora. The objective of this research was to investigate the soil biochemical 19,000 - 33,000 years before present. We measured extracellular enzyme activity specific to carbon metabolic response to permafrost degradation in response to the changing climate. processes using a fluorometric enzyme assay.

Method: Quadruplicate samples were carefully collected from active layer soils in three ecotones and per- Results / Discussion: Across all age categories, enzyme activities indicated the communities were capable mafrost from a nearby site in interior Alaska in the summer of 2015. Samples were immediately analyzed for of metabolizing a variety of carbohydrate and amino acid substrates. Highly active enzymes included those pH, redox, biochemical activity, and substrate utilization and stored frozen until DNA extractions were perfor- involved in the degradation of cellulose indicating the presence of carbon-associated metabolic strategies in med for follow-on amplicon and metagenomics sequence analysis. permafrost microbial consortia. As permafrost age increased, enzyme diversity, taxonomic diversity, enzyme activity, and ATPase activity decreased, which is consistent with previously collected metagenomic data. These Results / Discussion: Our results demonstrated differences in biochemical activity between ecotones, with data likely reflect lower biomass in older samples but shows maintenance of cellular activity over time. the sample plots that harbored the deepest permafrost exhibiting comparatively lower biochemical activity and substrate utilization. Vegetation in these plots was less diverse and dominated by cotton grass and Conclusion: Taken together these data demonstrate that active, carbon-utilizing microbial communities exist silvery sedge. Alternatively, the plots with shallow permafrost exhibited a higher plant diversity dominated by in Pleistocene permafrost despite limited nutrients and increasingly stressful conditions. birch, reducing conditions, elevated biological activity, and substrate utilization. Vegetative and soil bacterial composition patterns were similar across the sites, with environmental variables such as water content and permafrost driving bacterial and plant community composition at the site with deep permafrost and pH and redox driving biological composition at the site with shallow permafrost. Because deeper permafrost near these sites traps biochemical evidence that may reflect past climate conditions, prior relationships between plant and microflora were investigated. Our analysis of nearby permafrost showed that permafrost representing the time period between the last glacial maximum (cool, dry climate) and following glacial retreat (moist climate) contained a core paleomicrobiome dominated by Proteobacteria and Actinobacteria and vegetation dominated by willow. Actinobacteria in particular suggest the potential anabolism of bioactive metabolites and catabolism of complex carbon substrates.

Conclusion: Abiotic and biotic variables were measured to understand the impact of the changing climate on biodiversity in Alaska. Results from active layer soils provided insight into how thawing had impacted both vegetative and microflora patterns in similar ways. Furthermore, a deeper investigation of permafrost enabled insight into past community assemblages based on past climate trends. Together, these data will serve to forecast ecosystem changes as the climate warms.

85 Poster Abstracts Poster Abstracts

[P34] PHYSIOLOGICAL ADAPTATIONS OF CRYOCONITE MICROORGANISMS TO ANOXIA [P35] MOLECULAR DIVERSITY SNAPSHOT OF GLACIAL ALGAE

Ewa Poniecka1, Elizabeth Bagshaw2, Martyn Tranter3, Henrik Sass2, Alexandre Anesio3, Christopher Jakub Žárský1, Tyler Kohler1, Marek Stibal1, Adam Petrusek1 Williamson3 1 Charles University, Faculty of Science, Department of Ecology, Prague 2, Czech Republic 1 School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom 2 Cardiff University Aim: Glacial algae have recently received increased attention after a long period of being nearly neglected. 3 University of Bristol Interestingly, it happened for two independent reasons. The first is their contribution to the darkening of the Greenland ice sheet (GrIS) ablation zone as a result of their protective pigments, and thus increasing surface Aim: Microorganisms play a significant role in changing the physical properties of ice sheet surfaces. Cryoco- melt rates. The second reason is their taxonomical affiliation to the family Mesotaeniaceae (Conjugatophyceae nite holes are hotspots of microbial activity on glacier surfaces worldwide, yet little is known about the effects (=Zygnematophyceae), Streptophyta), which is according to current knowledge, the probable phylogenetically of redox conditions that develop within them on the microbial community. In this study, we aim to assess the closest algal lineage to land plants. presence of redox gradients and the presence of microbial communities adapted to the varying conditions along these gradients in samples of cryoconite from Greenland and Antarctica. Our research is motivated by the fact that the recent dating based on distances of different lineages of extant Streptophyta suggests a much deeper origin of the lineage splits leading to plants than the previous estimates Method: We used a combination of oxygen microsensor analyses and microbiological cultivation-based te- supported by paleontological records and previous molecular-clock-based studies. This timing in fact places chniques. A series of oxygen profiles was measured in Greenland and Antarctic cryoconite sediment incubat- the early evolution of terrestrial plants to the cryogenian era (Neoproterozoic, 720-635 million years ago), ions and in situ on Greenland Ice Sheet. Subsequently, microbial communities in cryoconite sediments were which permits us to assume the extant glacial algae to be possible inheritors of some ecological or physiologi- investigated by a most probable number (MPN) approach. In the MPN series, samples are serially diluted in cal traits, which might reveal new perspectives on the evolution of early land floras. parallel cultures and growth is assessed. This allows the estimation of the number of viable cells that can grow under the cultivation conditions. MPN series were incubated at a range of temperatures, and under oxic and Here we use the term “glacial algae” for a group of three genera of Mesotaeniaceae, which are regularly anoxic conditions. Pure cultures were isolated from the highest positive dilutions of the MPN series, represen- reported from different glacial systems around the globe. The term “ice algae” used some times in recent ting the most abundant microorganisms for each physiological condition. The strains were used to investigate literature, causes confusion with the sea-ice algal communities, typically dominated by diatoms. The compo- the adaptation of the cryoconite community to the fluctuating environmental conditions, particularly to the sition of phototrophic component of the microbiome of the bare ice is very different from snow microbiome dynamics of oxygen concentrations in the supraglacial system. dominated typically by the chlorophycean genera Chlamydomonas and Chloromonas and from cryoconite communities with the dominance of cyanobacterial phototrophs. Results / Discussion: We measured for the first time anoxic conditions at the microscale within cryoconite sediment and inside cryoconite granules from both poles, revealing a niche for anaerobic microorganisms Method: The most challenging aspect of examining these algae is the fact that they are resistant to cultivation and processes. The development of an anoxic zone within a thick layer of cryoconite sediment was observed attempts, and according to our best knowledge, no pure and sustainable culture of glacial algae is available to within an hour of mixing, showing unexpectedly rapid consumption of oxygen. Long-term (half year) incuba- science yet. tions of Greenland cryoconite material showed a peak of oxygen production and consumption after 40 days and reached a low-activity, steady state by Day 116, with a persisting anoxic zone. Anaerobic microorganisms We sampled a starting boom of glacial algae in the GrIS ablation zone in August 2015 from pooled replicates are therefore considered an important component of the cryoconite ecosystem which have received little at- for three localities adjacent to the “point 660” about 1 km apart of each other. The sampling was conducted tention to date. In the anoxic series, MPN numbers were elevated at 0.2°C and dropped significantly at higher by scraping the upper layer of ice with vegatation coloration with a clean tool from three different spots ca temperatures. Under oxic conditions, MPN numbers were highest at 10°C throughout the first three months 20 m apart at each locality and the samples were collected into sterile Whirl-pak bags. The samples were of the experiment. Subsequent physiological experiments on pure cultures reveal surprising versatility and left to melt gently on ice and to sediment. After they completely melted, the supernatant was decanted, the broad adaptation for a various condition of cryoconite bacterial species. concentrated suspension was examined microscopically, aliquoted into 2 ml eppendorf tubes, preserved with a nucleic acid preservative (LifeGuard®:suspension 1:3) and frozen in a portable freezer. The samples were Conclusion: We infer that anoxic zones are an important factor in the development of cryoconite microbial transported and stored frozen until the eDNA extraction. The extracted eDNA from replicate samples for each communities, and that microorganisms are well-adapted to the physiological challenges posed by the extreme locality was pooled and used as a template for 5 PCR reactions, targeting five markers (rbcL, 23S, cox III and polar environment. 2 overlapping regions of 18S), using HiFi polymerase with proof reading function. The amplified material was purified, quantified and sequenced using Illumina platform.

Results / Discussion: We observed large proportionAncylonema and Mesotaenium with occasional occurrence of cells of Cylindrocystisfound in all of the samples. We expect these sequence data should represent a snapshot of molecular diversity of glacial algal assemblages, providing some basic information on the community inhabitants as well as the molecular diversity of the algae. We received the raw sequencing data shortly before the abstract submission deadline and the conclusions will therefore be presented in September 2017 in Nuuk.

87 Poster Abstracts Poster Abstracts

[P36] A model of virus-host interactions in sea ice brines incorporating dynamics of cold- [P37] Cold-active enzymes from the psychrophilic bacterium glaciibacter superstes involved in adapted Colwellia psychrerythraea strain 34H and Colwelliaphage 9A pyrimidine nucleotide biosynthesis

Gordon Showalter1, Jody Deming1 Antonio Mondini¹ , Cristina Purcarea¹ 1 University of Washington 1 Institute of Biology, Bucharest, Romania

Aim: Bacteriophage, viruses that infect bacteria, are important drivers of gene exchange, population dynamics, Aim: Psychrophiles have evolved by producing cold-active enzymes able to cope with the reduction of and elemental cycling in marine environments. It has been observed that phages are unusually concentrated in chemical reaction rates induced by low temperatures. To unravel the thermal adaptation mechanisms of DNA sea ice and therefore likely to play an important role in sea ice microbial ecosystems. The population dynamics synthesis in psychrophilic bacteria, we investigate the structural and functional properties of the key enzymes within sea ice leading to these high concentrations are unknown. We seek to understand factors contributing catalyzing the first steps of pyrimidine biosynthesis, aspartate transcarbamoylase (ATC), and dihydroorotase to high virus to bacteria ratios in sea ice. (DHO) from Glaciibacter superstes. The genome of this psychrophilic strain isolated from a permafrost ice wedge in Alaska indicated a particular gene composition for this pathway. Method: To elucidate the governing mechanisms of virus to bacteria ratios in sea ice brines, we have coupled an existing model of virus-host encounter rates in brines as a function of temperature to a population model Method: Protein sequence analysis structure was carried out using EMBL-EBI Clustal Omega and Emboss constrained by laboratory and field observations. This population model is the first to incorporate parameters Needle softwares, and ExPASy ProtParam computational tool. Cloning of the ATC and DHO genes of G. superstes was performed by PCR amplification and insertion in pHAT2 expression vector. The genes were from our model cold-adapted bacterium, Colwellia psychrerythraea strain 34H, and its cold-active phage, Col- 2+ welliaphage 9A, for multiple scenarios of temperature, exopolymer production, and lifetime of the ice. expressed in E. coli BL21(DE3), and the proteins were purified in one step by affinity chromatography on Ni - chelating resin. Results / Discussion: Results from this model indicate that controls on the bacterial population, rather than high rates of viral production or slow rates of viral decay, may be the leading contributor to the high virus to bac- Results / Discussion: Sequence analysis of the two enzymes revealed the conservation of active site residues, teria ratios observed in sea ice. Final virus to bacteria ratios are sensitive to initial conditions, however, which and of the ATC-DHO interface of the stable complex of these two catalysts found in the hyperthermophilic may explain variable field observations in the literature. bacterium Aquifex aeolicus. Aminoacid composition of bothG. superstes enzymes revealed the absence (ATC) or a reduced content (DHO) of Cys, an increased Gly content and a reduced content of Phe residues, structural Conclusion: This model provides an opportunity to develop hypotheses on the role of bacteriophage in sea features correlated with the cold-adapted enzyme flexibility. The activity and regulatory response of individual ice brines over highly variable conditions, and can be used to inform future field work and laboratory studies. and associated recombinant enzymes, in addition to their thermal stability, are currently under investigation. Furthermore, results from this model may have implications for understanding phage-driven water column processes, as melting sea ice seeds polar oceans with both bacteria and viruses. Conclusion: Corroboration of the structural and functional properties of these key enzymes of thede novo synthesis of pyrimidine nucleotides in a cold-adapted bacterium will contribute to understand the phylogeny and adaptation mechanisms to extreme environmental conditions of this class of enzymes. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 675546

89 Poster Abstracts Poster Abstracts

[P38] Coverage of glacial surfaces with industrial fleece to reduce ablation: economic blessing [P39] On developing a genetic transformation system for the psychrophilic marine bacterium or ecological spell? colwellia psychrerythraea 34h

Sabrina Obwegeser¹ Zachary Cooper¹, Jody Deming¹ 1 University of Innsbruck; Innsbruck, Austria 1 University of Washington, United States

Climate change affects the alpine region in several ways. Due to increasing temperatures the year round usage Aim: Genetic transformation involves the directed alteration of a genome in vivo using external gene of ski slopes of glacial areas in the Alps is endangered implying enormous economic as well as ecological constructs which is useful for understanding physiology on the level of individual genes. Colwellia consequences. In the last decades, all tyrolean glacial skiing areas suffer from a large loss of snow and ice psychrerythraea 34H is a marine psychrophile isolated from subzero Arctic sediments, with closely related resources. Thus, large areas in the skiing regions are covered by an industrial fleece made of polypropylene. strains found in sea ice and cold seawater. In developing an efficient system for genetic transformation in This strategy can help to reduce ablation and preserve approx. 1.5 m of snow during the summer period this organism, our long-term aim is to conduct targeted analyses of important biochemical pathways and to from May-September per year. The economic gain is evident, however, there are serious ecological concerns determine the role of lateral gene exchange at low temperature using this bacterium as a model. regarding the usage of this fleece on snow. As a harsh but biologically active living environment harboring Method: Conventional electroporation techniques for genetic transformation pose a dilemma in bacteria numerous communities consisting of microbes and metazoa, it is necessary to investigate the consequences requiring at least moderate salt concentrations to prevent lysis from osmotic stress because ion-free medium of this fleece coverage on the living condition as well as community composition. Liquid water is a limiting is generally required to prevent undesired electrical shocks during electroporation. Herein, we use a modified factor in this extreme ecosystem and therefor the coverage during the main growth period most likely medium containing the osmoprotectant glycine betaine to help avoid osmotic shock during electroporation. changes a multitude of parameters such as biogeochemistry, biological activity and biodiversity. Though, Uracil biosynthesis is targeted for the creation of an auxotrophic mutant by using 5-fluoroorotic acid to select another alarming fact is the presence of a lubricant in the fleece. This component is known to be water for the deletion of an essential gene in this pathway. soluble and is determined as hazardous to water in the European Union. During melting phases and precipitation events this lubricant will be dissolved from the fleece and potentially will not only affect the Results / Discussion: These and other methods under development will allow for the alteration of the living communities concerning biodiversity and activity but also the water chemistry which is also altering genome of C. pyschrerythraea 34H. Initial targets include genes for compatible solute transporters, viral downstream waters to the valleys. The investigations took place on a glacial area in the Stubai Alps, Austria. receptor proteins, and proteins involved in the production and release of cryoprotectants. The optimized The fleece coverage at our study area was present from May-September 2016 simulating the standard transformation system is expected to be used to explore lateral gene transfer in the cold and across disciplines covering period in the Tyrolean Alps on all glacial skiing resorts. To obtain an overall examination of the where low-temperature production of biological substances is of interest. various effect of the fleece coverage we arranged 3 different situations including a control area with no fleece Conclusion: Combining physiological knowledge of bacterial behavior under stress (e.g., osmotic pressure) cover, a fleece covered area with the conventional polypropylene fleece as well as a fleece covered area with conventional transformation techniques (e.g., electroporation) can lead to a novel transformation system using a washed fleece to remove the lubricant. Snow and ice samples of uncovered and covered areas were and thus a new avenue for the study of low-temperature microbiology. Developing a genetic system for collected in triplicates every third week until final snow melt. In addition to an extensive biogeochemical 34H will provide a unique model system to fill this niche. investigation, we aimed for a detailed biodiversity survey via NGS. Bacterial numbers were quantified via Colwellia psychrerythraea epifluorescence microscopy and bacterial productivity was measured by incorporation of 3H-leucine. Furthermore, we are investigating the effects of the water soluble lubricant on occurring microorganisms using cultivation experiments. Based on results of a pilot study on a test field we are expecting significant differences between covered and uncovered glacier areas concerning their nutrient availability as well as microbial community composition. The lack of incoming radiation, nutrient deficiency and additional impurity with the potentially deleterious lubricant may lead to a reduction or shift of biodiversity, activity and water quality within such a sensitive ecosystem. Thus, this measure to preserve glacial areas for skiing requires a serious reassessment. KEYWORDS: GLACIERS, ABLATION CONTROL, CLIMATE CHANGE, LUBRICANT,

91 Poster Abstracts Poster Abstracts

[P40] Darkening of greenland ice sheet driven by photo-inhibition of ice algal communities [P41] Distinctive characters of symbiotic Nostoc cyanobacteria

Christopher Williamson1, Alexandre Anesio1, Ewa Poniecka2, Joseph Cook3, Andrew Tedstone1, Rupert Ólafur Andrésson1, Andrey Gagunashvili Perskins2, Daniel Fagan1, Martyn Tranter1, Marian Yallop1 1 Institut: University of Iceland, Iceland 1 University of Bristol, Bristol, United Kingdom 2 Cardiff University, Cardiff, United Kingdom 3 University of Sheffield, Sheffield, United Kingdom

Aim: Given their significant contribution to bio-albedo and consequently melt, it is fundamental to constrain Aim: Cyanobacteria of the genus Nostoc can form symbioses and close associations with a number of the factors regulating ice algal assemblages that dominate surface habitats of the Greenland Ice Sheet different organisms, including lichens, mosses and biological soil crusts, often predominant in cold terrestrial (GrIS). Within such habitats, ice algae must navigate a myriad of abiotic stressors to maintain productivity habitats. Only a restricted group of Nostoc strains have the ability to form symbioses. In order to elucidate and thus survival, including freeze-thaw cycles, nutrient limitation, and excessive exposure to both UV- and what characterizes symbiotic Nostoc we have sequenced and annotated the genomes of five lichen-derived photosynthetically active-radiation (PAR, 400 – 700nm). Whilst initial research indicated the production of strains and compared them to other symbiotic and non-symbiotic Nostoc genomes. specialist (albedo-reducing) pigments that facilitate algal existence on the GrIS, a comprehensive examination Method: Nostoc cyanobacteria from Peltigera membranacea and Lobaria pulmonaria were isolated and of ice algal ecophysiology under in-situ conditions has been lacking until now. cultured on BG11 medium without fixed nitrogen, DNA extracted and sequenced on the Illumina platform, the Method: Here we report the outcomes of a combined approach to constrain the balance between abiotic reads assembled and annotated with reference to well annotated bacterial genomes. stressors and maintenance of robust assemblages, by pairing assessments of photophysiology, productivity, and pigment regulation, with both experimental manipulations of key abiotic stressors, and monitoring of ice Results / Discussion: Comparison of six symbiotic vs. eight non-symbiotic Nostoc and Anabaena genomes allowed identification of several unique gene clusters. One of them had been identified and experimentally surface habitats. All work was performed in-situ on the GrIS, ~35 km inland of the western margin, as part of the inaugural field campaign of the Black and Bloom project during July/August 2016. verified in the cycad symbiont Nostoc punctiforme ATCC 29133. Three of the lichen Nostoc strains harbored an alternative nitrogenase system based on vanadium in addition to the canonical molybdenum based system. Results / Discussion: Our data demonstrate the mechanisms of photo-acclimation and -regulation that underlie the ability of ice algae to persist despite significant photo-stress, though highlight the paradoxical Conclusion: A distinctive set of genes enables Nostoc cyanobacteria to form symbioses with a wide range of role of irradiance in limiting productivity, and thus ultimately algal biomass, in surface habitats. With hosts, including cryptogams common and characteristic for polar and alpine regions. These cyanobacteria also manipulative reductions in irradiance, but maintenance of ambient nutrient concentrations, consistent frequently contain a second nitrogenase system utilizing vanadium rather than molybdenum, most likely due increases in the maximum light utilisation efficiency ( ) and maximum electron transport rates ( ) of either shortage of molybdenum or an advantage in cold habitats. Fv/Fm ETRmax photosystem-II were evident, revealing an inverse relationship between carbon fixation and PAR above ~50% ambient levels. Ice algal productivity under ambient ice sheet conditions is thus limited by excess irradiance, i.e. photo-inhibition. Oximetry based measurements provided confirmation, with maximal rates of net production (1.09 ± 0.02 mg C -1l d-1) apparent at 50% ambient PAR, and 62% of maximal productivity achieved with just 13% PAR. Non-regulated non-photochemical quenching (Y[NO]) is effectively exhausted underin-situ conditions, with production and inter-conversion of carotenoid pigments during regulated non-photochemical quenching (Y[NPQ]) serving as the primary mechanism underlying ice algal photo-regulation. This results in the accumulation of specific albedo-reducing pigments in GrIS surface ice habitats. Conclusion: By combining this new knowledge of pigment dynamics, with regular assessments of cell sizes, biomass concentrations and spectral reflectance measurements taken across the 2016 melt season, we are able to characterize the influence of ice algae on the surface albedo, including absorption at specific wavelengths due to particular pigments. This enables us to characterize the biological drivers of ice surface albedo reduction.

93 Poster Abstracts Notes

[P42] "Tropical diversity" of Arctic penicillia

L. Perini¹, J.C. Frisvad², P. Zalar¹, C. Gostinčar¹, N. Gunde – Cimerman¹ 1 Chair of Molecular Genetics and Biology of Microorganisms, dept. Biology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia. 2 Dept. of Microbial Ecology and Chemistry, Fungal Chemodiversity, Technical University of Denmark, Søltofts Plads, Building 221, 2800 Kgs. Lyngby, Denmark.

Previous studies of penicillia from alpine and polar areas demonstrated a very high biological and chemical diversity usually ascribed to tropical environments. They have been isolated from glacial and sub-glacial ice, marine water, sea-ice, snow, melt-water, clouds and permafrost, carcasses of animals and plant material. The isolates can be broadly divided into two groups: (i) ubiquitous mesophilic species and (ii) quasi-psychrophilic or psychrotolerant ones. Representative species of the (i) mesophilic ubiquitous group, such as P. crustosum, P. nordicum and P. solitum displayed some minor distinguishing phenotypic differences from food-borne isolates of the same species originating from temperate areas. Additionally, while these species tipically show a high chemical diversity, polar isolates produced some metabolites, such as andrastine, with an even higher frequency compared to isolates from temperate areas (1,2). Within the quasi-psychrophilic and psychrotolerant group many new species were discovered. Those that were already formally described, such as P. spatulatum, P. buchwaldii and P. jamesonlandense, showed a surprisingly high chemodiversity and bioactivity, not expected in cold environments. For example, only the Arctic quasi-psychrophilic and psychrotolerant species produced the unique cyclic peptides psychrophilins and cycloaspeptides and some other interesting metabollites. Within this group many species still await to be described, foremost in the Ramosa section of Penicillium, but also in the section Brevicompacta.

Sonjak S., J.C. Frisvad, N. Gunde – Cimerman. Comparison of secondary metabolite production by Penicillium crustosum strains, isolated from Arctic and other various ecological niches. FEMS Microbiol Ecol (2005) 53 (1): 51-60. Frisvad, J.C., Larsen, T.O., Dalsgaard, P.W., Seifert, K.A., Louis-Seize, G., Lyhne, E.K., Jarvis, B.B., Fettinger, J.C. and Overy, D.P 2006. Four psychrotolerant species with high chemical diversity consistently producing cycloaspeptide A, P. jamesonlandense sp. nov., P. ribium sp. nov., P. soppii and P. lanosum. International Journal of Systematic and Evolutionary Microbiology 56: 1427-1437.

Frisvad, J.C., Houbraken, J., Popma, S. and Samson, R.A. 2013. Two new Penicillium species P. buchwaldii and P. spathulatum, producing the anticancer compound asperphenamate. FEMS Microbiology Letters 339: 77-92. Notes Notes Sponsors & Supporters