DOCSLIB.ORG

Protistan Grazing Impacts Microbial Communities and Carbon Cycling at Deep-Sea Hydrothermal Vents

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Protistan Grazing Impacts Microbial Communities and Carbon Cycling at Deep-Sea Hydrothermal Vents bioRxiv preprint doi: https://doi.org/10.1101/2021.02.08.430233; this version posted February 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Protistan grazing impacts microbial communities and carbon cycling at deep- 2 sea hydrothermal vents 3 4 Sarah K. Hu1*, Erica L. Herrera1, Amy R. Smith1, Maria G. Pachiadaki2, Virginia P. Edgcomb3, 5 Sean P. Sylva1, Eric W. Chan4, Jeffrey S. Seewald1, Christopher R. German3, Julie A. Huber1 6 7 1. Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic 8 Institution, Woods Hole, MA 02543 9 2. Department of Biology, Woods Hole Oceanographic Institution, Woods Hole MA, 02543 10 3. Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods 11 Hole, MA 02543 12 4. School of Earth, Environment & Marine Sciences, UT-RGV, Edinburg, TX 78539 13 14 15 16 17 *Corresponding author: 18 Sarah K. Hu 19 266 Woods Hole Rd MS#51 20 Woods Hole MA, 02543 21 [email protected] 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.02.08.430233; this version posted February 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 43 Abstract 44 Microbial eukaryotes (or protists) in marine ecosystems are a link between microbial primary 45 producers and all higher trophic levels. The rate at which heterotrophic protistan grazers 46 consume microbial prey and recycle organic matter is an important factor that influences marine 47 microbial food webs and carbon cycling. At deep-sea hydrothermal vents, chemosynthetic 48 bacteria and archaea form the base of a food web that functions in the absence of sunlight, but 49 the role of protistan grazers in these highly productive ecosystems is largely unexplored. Here, 50 we pair grazing experiments with a molecular survey to quantify protistan grazing and to 51 characterize the composition of vent-associated protists in low-temperature venting fluids from 52 Gorda Ridge in the North East (NE) Pacific Ocean. Results reveal protists exert higher predation 53 pressure at vents compared to the surrounding deep seawater environment and may account for 54 consuming 28-62% of the daily stock of prokaryotic biomass within the hydrothermal vent food 55 web. The vent-associated protistan community was more species rich relative to the background 56 deep sea, and patterns in the distribution and co-occurrence of vent microbes provide additional 57 insights into potential predator-prey interactions. Ciliates, followed by dinoflagellates, 58 Syndiniales, rhizaria, and stramenopiles dominated the vent protist community and included 59 bacterivorous species, species known to host symbionts, and parasites. Our findings provide an 60 estimate of protistan grazing pressure within hydrothermal vent food webs, highlighting the role 61 that diverse deep-sea protistan communities have in carbon cycling. 62 Significance 63 Heterotrophic protists are ubiquitous in all aquatic ecosystems and represent an important 64 ecological link because they transfer organic carbon from primary producers to higher trophic 65 levels. Here, we quantify the predator-prey trophic interaction among protistan grazers and 66 microbial prey at multiple sites of hydrothermal venting near the Gorda Ridge spreading center 67 in the NE Pacific Ocean. Grazing pressure was higher at the site of active diffuse flow and was 68 carried out by a highly diverse assemblage of protistan species; elevated grazing rates are 69 attributed to higher concentrations of chemosynthetic microorganisms and biological diversity 70 localized to hydrothermal vent environments. 71 72 2 bioRxiv preprint doi: https://doi.org/10.1101/2021.02.08.430233; this version posted February 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 73 Introduction 74 Mixing of venting hydrothermal fluids with surrounding seawater in the deep sea creates redox 75 gradients that promote a hub of biological activity supported by chemosynthetic primary 76 production in the absence of sunlight. These localized regions of elevated microbial biomass are 77 important sources of carbon and energy to the surrounding deep-sea ecosystem (1–5). In 78 particular, the consumption of hydrothermal vent microorganisms by single-celled microbial 79 eukaryotes (or protists) is an important link in the food web where carbon is transferred to higher 80 trophic levels or remineralized to the microbial loop. 81 82 Protistan grazing is a significant source of mortality for bacterial and archaeal 83 populations in aquatic ecosystems that also influences their composition and diversity (6). 84 Assessments of grazing in the mesopelagic and dark ocean have found that rates of consumption 85 decrease with depth and correspond to bacterial abundance (7, 8). Therefore, at sites of increased 86 biological activity and microbial biomass, such as areas of redox stratification, protistan grazing 87 is higher relative to the rest of the water column (9, 10). Comparable data have been lacking 88 from deep-sea hydrothermal vents, where the relatively high microbial biomass and rates of 89 primary productivity suggest protistan grazing should be a significant source of microbial 90 mortality and carbon transfer. Further, single-celled microbial eukaryotes can serve as a 91 nutritional resource for other larger protists and higher trophic levels (4, 11). 92 93 Early microscopic and culture-based experiments from several hydrothermal vents 94 confirmed the presence of single-celled microbial eukaryotes, with observations and enrichment 95 cultures revealing diverse assemblages of flagellated protists and ciliates (12, 13). The study of 96 protistan taxonomy and distribution via genetic analyses at deep-sea vents has uncovered a 97 community largely composed of alveolates, stramenopiles, and rhizaria (14–17). In addition to 98 many of these sequence surveys identifying known bacterivorous species, ciliates isolated from 99 Guaymas Basin were shown to consume an introduced prey analog (18). Collectively, these 100 studies provide supporting evidence of a diverse community of active protistan grazers at deep- 101 sea vents. 102 3 bioRxiv preprint doi: https://doi.org/10.1101/2021.02.08.430233; this version posted February 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 103 Here, we investigate protistan predation pressure upon microbial populations in venting 104 fluids along the Gorda Ridge to test the hypothesis that protistan grazing and diversity is elevated 105 within hydrothermal habitats compared to the surrounding deep sea due to increased prey 106 availability. Estimates of mortality via protistan phagotrophy are calculated from grazing 107 experiments conducted with low temperature diffusely venting fluid that mixes with seawater at 108 and below the seafloor. Paired 18S rRNA gene amplicon sequencing from the same experimental 109 sites and incubations reveal the in situ protistan diversity and distribution to evaluate potential 110 preferences in prey, with a focus on the protistan grazer population and their relationship to 111 bacteria and archaea. We present quantitative estimates of protistan grazing from a deep-sea 112 hydrothermal vent ecosystem, thus providing new details into the role protists play in food webs 113 and carbon cycling in the deep sea. 114 Results & Discussion 115 Sea Cliff and Apollo hydrothermal vent fields 116 Low-temperature (10-80ºC) diffusely venting fluids were collected at the Sea Cliff and Apollo 117 hydrothermal vent fields along the Gorda Ridge (Figure S1; 19, 20, 21). Hydrothermal vent 118 fluids collected for experiments and genetic analysis were geochemically distinct from plume (5 119 m above active venting), near vent bottom water (lateral to venting fluid), and background 120 seawater (outside the range of hydrothermal influence; Table 1). The concentration of bacteria 121 and archaea was 5-10 x 104 cells ml-1 in low temperature vent fluids, which was higher than 122 background seawater concentrations (3-5 x 104 cells ml-1; Table 1). Diffuse vents sampled in 123 both fields represented a mixture of nearby high temperature vent fluid (Candelabra, 298ºC and 124 Sir Ventsalot, 292ºC) with seawater (22). During sample collection (30-40 minutes), the 125 temperature of the fluid being sampled fluctuated between 3-72ºC, due to mixing (Table 1). The 126 temperature maxima at Mt. Edwards and Venti Latte were lower compared to Candelabra and Sir 127 Ventsalot, and ranged from 11-40ºC; these sites also had visible tube worm clusters 128 (Paralvinella palmiformis; Figure S1; Table 1). 4 bioRxiv preprint doi: https://doi.org/10.1101/2021.02.08.430233; this version posted February 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 129 Protistan grazers exert predation pressure on hydrothermal vent bacteria and archaea 130 Grazing incubations conducted with fluids collected from five sites within the Sea Cliff and 131 Apollo vent fields demonstrate that microbial eukaryotes actively graze microbial communities 132 in hydrothermal vent fluids at an elevated rate relative to the surrounding deep-sea environment 133 (Figure 1).
Load more

Recommended publications
  • Lipid Analysis of CO2-Rich Subsurface Aquifers Suggests an Autotrophy-Based Deep Biosphere with Lysolipids Enriched in CPR Bacteria
    The ISME Journal (2020) 14:1547–1560 https://doi.org/10.1038/s41396-020-0624-4 ARTICLE Lipid analysis of CO2-rich subsurface aquifers suggests an autotrophy-based deep biosphere with lysolipids enriched in CPR bacteria 1,2 3,4 1,3 3 3 Alexander J. Probst ● Felix J. Elling ● Cindy J. Castelle ● Qingzeng Zhu ● Marcus Elvert ● 5,6 6 1 7,9 7 Giovanni Birarda ● Hoi-Ying N. Holman ● Katherine R. Lane ● Bethany Ladd ● M. Cathryn Ryan ● 8 3 1 Tanja Woyke ● Kai-Uwe Hinrichs ● Jillian F. Banfield Received: 20 November 2018 / Revised: 5 February 2020 / Accepted: 25 February 2020 / Published online: 13 March 2020 © The Author(s) 2020. This article is published with open access Abstract Sediment-hosted CO2-rich aquifers deep below the Colorado Plateau (USA) contain a remarkable diversity of uncultivated microorganisms, including Candidate Phyla Radiation (CPR) bacteria that are putative symbionts unable to synthesize membrane lipids. The origin of organic carbon in these ecosystems is unknown and the source of CPR membrane lipids remains elusive. We collected cells from deep groundwater brought to the surface by eruptions of Crystal Geyser, sequenced 1234567890();,: 1234567890();,: the community, and analyzed the whole community lipidome over time. Characteristic stable carbon isotopic compositions of microbial lipids suggest that bacterial and archaeal CO2 fixation ongoing in the deep subsurface provides organic carbon for the complex communities that reside there. Coupled lipidomic-metagenomic analysis indicates that CPR bacteria lack complete lipid biosynthesis pathways but still possess regular lipid membranes. These lipids may therefore originate from other community members, which also adapt to high in situ pressure by increasing fatty acid unsaturation.
    [Show full text]
  • The Planktonic Protist Interactome: Where Do We Stand After a Century of Research?
    bioRxiv preprint doi: https://doi.org/10.1101/587352; this version posted May 2, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Bjorbækmo et al., 23.03.2019 – preprint copy - BioRxiv The planktonic protist interactome: where do we stand after a century of research? Marit F. Markussen Bjorbækmo1*, Andreas Evenstad1* and Line Lieblein Røsæg1*, Anders K. Krabberød1**, and Ramiro Logares2,1** 1 University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology (Evogene), Blindernv. 31, N- 0316 Oslo, Norway 2 Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, ES-08003, Barcelona, Catalonia, Spain * The three authors contributed equally ** Corresponding authors: Ramiro Logares: Institute of Marine Sciences (ICM-CSIC), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain. Phone: 34-93-2309500; Fax: 34-93-2309555. [email protected] Anders K. Krabberød: University of Oslo, Department of Biosciences, Section for Genetics and Evolutionary Biology (Evogene), Blindernv. 31, N-0316 Oslo, Norway. Phone +47 22845986, Fax: +47 22854726. [email protected] Abstract Microbial interactions are crucial for Earth ecosystem function, yet our knowledge about them is limited and has so far mainly existed as scattered records. Here, we have surveyed the literature involving planktonic protist interactions and gathered the information in a manually curated Protist Interaction DAtabase (PIDA). In total, we have registered ~2,500 ecological interactions from ~500 publications, spanning the last 150 years.
    [Show full text]
  • Microbial Carbon Metabolism Associated with Electrogenic Sulphur Oxidation in Coastal Sediments
    The ISME Journal (2015) 9, 1966–1978 & 2015 International Society for Microbial Ecology All rights reserved 1751-7362/15 OPEN www.nature.com/ismej ORIGINAL ARTICLE Microbial carbon metabolism associated with electrogenic sulphur oxidation in coastal sediments Diana Vasquez-Cardenas1,2, Jack van de Vossenberg2,6, Lubos Polerecky3, Sairah Y Malkin4,7, Regina Schauer5, Silvia Hidalgo-Martinez2, Veronique Confurius1, Jack J Middelburg3, Filip JR Meysman2,4 and Henricus TS Boschker1 1Department of Marine Microbiology, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands; 2Department of Ecosystem Studies, Royal Netherlands Institute for Sea Research (NIOZ), Yerseke, The Netherlands; 3Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands; 4Department of Environmental, Analytical and Geo-Chemistry, Vrije Universiteit Brussel (VUB), Brussels, Belgium and 5Centre of Geomicrobiology/Microbiology, Department of Bioscience, Aarhus University, Aarhus, Denmark Recently, a novel electrogenic type of sulphur oxidation was documented in marine sediments, whereby filamentous cable bacteria (Desulfobulbaceae) are mediating electron transport over cm- scale distances. These cable bacteria are capable of developing an extensive network within days, implying a highly efficient carbon acquisition strategy. Presently, the carbon metabolism of cable bacteria is unknown, and hence we adopted a multidisciplinary approach to study the carbon substrate utilization of both cable bacteria and associated microbial community in sediment incubations. Fluorescence in situ hybridization showed rapid downward growth of cable bacteria, concomitant with high rates of electrogenic sulphur oxidation, as quantified by microelectrode profiling. We studied heterotrophy and autotrophy by following 13C-propionate and -bicarbonate incorporation into bacterial fatty acids. This biomarker analysis showed that propionate uptake was limited to fatty acid signatures typical for the genus Desulfobulbus.
    [Show full text]
  • Unlocking the Genomic Taxonomy of the Prochlorococcus Collective
    bioRxiv preprint doi: https://doi.org/10.1101/2020.03.09.980698; this version posted March 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. Unlocking the genomic taxonomy of the Prochlorococcus collective Diogo Tschoeke1#, Livia Vidal1#, Mariana Campeão1, Vinícius W. Salazar1, Jean Swings1,2, Fabiano Thompson1*, Cristiane Thompson1* 1Laboratory of Microbiology. SAGE-COPPE and Institute of Biology. Federal University of Rio de Janeiro. Rio de Janeiro. Brazil. Av. Carlos Chagas Fo 373, CEP 21941-902, RJ, Brazil. 2Laboratory of Microbiology, Ghent University, Gent, Belgium. *Corresponding authors: E-mail: [email protected] , [email protected] Phone no.: +5521981041035, +552139386567 #These authors contributed equally. ABSTRACT 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.03.09.980698; this version posted March 11, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. Prochlorococcus is the most abundant photosynthetic prokaryote on our planet. The extensive ecological literature on the Prochlorococcus collective (PC) is based on the assumption that it comprises one single genus comprising the species Prochlorococcus marinus, containing itself a collective of ecotypes. Ecologists adopt the distributed genome hypothesis of an open pan-genome to explain the observed genomic diversity and evolution patterns of the ecotypes within PC.
    [Show full text]
  • Biology and Systematics of Heterokont and Haptophyte Algae1
    American Journal of Botany 91(10): 1508±1522. 2004. BIOLOGY AND SYSTEMATICS OF HETEROKONT AND HAPTOPHYTE ALGAE1 ROBERT A. ANDERSEN Bigelow Laboratory for Ocean Sciences, P.O. Box 475, West Boothbay Harbor, Maine 04575 USA In this paper, I review what is currently known of phylogenetic relationships of heterokont and haptophyte algae. Heterokont algae are a monophyletic group that is classi®ed into 17 classes and represents a diverse group of marine, freshwater, and terrestrial algae. Classes are distinguished by morphology, chloroplast pigments, ultrastructural features, and gene sequence data. Electron microscopy and molecular biology have contributed signi®cantly to our understanding of their evolutionary relationships, but even today class relationships are poorly understood. Haptophyte algae are a second monophyletic group that consists of two classes of predominately marine phytoplankton. The closest relatives of the haptophytes are currently unknown, but recent evidence indicates they may be part of a large assemblage (chromalveolates) that includes heterokont algae and other stramenopiles, alveolates, and cryptophytes. Heter- okont and haptophyte algae are important primary producers in aquatic habitats, and they are probably the primary carbon source for petroleum products (crude oil, natural gas). Key words: chromalveolate; chromist; chromophyte; ¯agella; phylogeny; stramenopile; tree of life. Heterokont algae are a monophyletic group that includes all (Phaeophyceae) by Linnaeus (1753), and shortly thereafter, photosynthetic organisms with tripartite tubular hairs on the microscopic chrysophytes (currently 5 Oikomonas, Anthophy- mature ¯agellum (discussed later; also see Wetherbee et al., sa) were described by MuÈller (1773, 1786). The history of 1988, for de®nitions of mature and immature ¯agella), as well heterokont algae was recently discussed in detail (Andersen, as some nonphotosynthetic relatives and some that have sec- 2004), and four distinct periods were identi®ed.
    [Show full text]
  • The Eastern Nebraska Salt Marsh Microbiome Is Well Adapted to an Alkaline and Extreme Saline Environment
    life Article The Eastern Nebraska Salt Marsh Microbiome Is Well Adapted to an Alkaline and Extreme Saline Environment Sierra R. Athen, Shivangi Dubey and John A. Kyndt * College of Science and Technology, Bellevue University, Bellevue, NE 68005, USA; [email protected] (S.R.A.); [email protected] (S.D.) * Correspondence: [email protected] Abstract: The Eastern Nebraska Salt Marshes contain a unique, alkaline, and saline wetland area that is a remnant of prehistoric oceans that once covered this area. The microbial composition of these salt marshes, identified by metagenomic sequencing, appears to be different from well-studied coastal salt marshes as it contains bacterial genera that have only been found in cold-adapted, alkaline, saline environments. For example, Rubribacterium was only isolated before from an Eastern Siberian soda lake, but appears to be one of the most abundant bacteria present at the time of sampling of the Eastern Nebraska Salt Marshes. Further enrichment, followed by genome sequencing and metagenomic binning, revealed the presence of several halophilic, alkalophilic bacteria that play important roles in sulfur and carbon cycling, as well as in nitrogen fixation within this ecosystem. Photosynthetic sulfur bacteria, belonging to Prosthecochloris and Marichromatium, and chemotrophic sulfur bacteria of the genera Sulfurimonas, Arcobacter, and Thiomicrospira produce valuable oxidized sulfur compounds for algal and plant growth, while alkaliphilic, sulfur-reducing bacteria belonging to Sulfurospirillum help balance the sulfur cycle. This metagenome-based study provides a baseline to understand the complex, but balanced, syntrophic microbial interactions that occur in this unique Citation: Athen, S.R.; Dubey, S.; inland salt marsh environment.
    [Show full text]
  • 176024V2.Full.Pdf
    bioRxiv preprint doi: https://doi.org/10.1101/176024; this version posted August 18, 2017. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Integrative analysis of large scale transcriptome data draws a comprehensive functional 2 landscape of Phaeodactylum tricornutum genome and evolutionary origin of diatoms 3 4 Achal Rastogi1, Uma Maheswari2, Richard G. Dorrell1, Florian Maumus3, Fabio Rocha Jimenez 5 Vieira1, Adam Kustka4, James McCarthy5, Andy E. Allen5, 6, Paul Kersey2, Chris Bowler1* and 6 Leila Tirichine1* 7 8 9 1Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l’Ecole Normale 10 Supérieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d’Ulm, F-75005 Paris, France 11 2EMBL-EBI, Wellcome Trust Genome Campus, Cambridge, CB10 1SD, United Kingdom 12 3INRA, UR1164 URGI—Research Unit in Genomics-Info, INRA de Versailles-Grignon, Route de 13 Saint-Cyr, Versailles 78026, France 14 4Earth and Environmental Sciences, Rutgers University, 101 Warren Street, 07102 Newark, 15 New Jersey, USA 16 5J. Craig Venter Institute, 10355 Science Center Drive, 92121 San Diego, California, USA 17 6Integrative Oceanography Division, Scripps Institution of Oceanography, University of 18 California San Diego, La Jolla, California, USA 19 20 * Authors for correspondence; [email protected] and [email protected] 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 1 bioRxiv preprint doi: https://doi.org/10.1101/176024; this version posted August 18, 2017.
    [Show full text]
  • A Functional Approach to Resolving the Biogeocomplexity of Two Extreme Environments Haydn Rubelmann III University of South Florida, [email protected]
    University of South Florida Scholar Commons Graduate Theses and Dissertations Graduate School 11-12-2014 A Functional Approach to Resolving the Biogeocomplexity of Two Extreme Environments Haydn Rubelmann III University of South Florida, [email protected] Follow this and additional works at: https://scholarcommons.usf.edu/etd Part of the Marine Biology Commons, and the Microbiology Commons Scholar Commons Citation Rubelmann, Haydn III, "A Functional Approach to Resolving the Biogeocomplexity of Two Extreme Environments" (2014). Graduate Theses and Dissertations. https://scholarcommons.usf.edu/etd/5432 This Dissertation is brought to you for free and open access by the Graduate School at Scholar Commons. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Scholar Commons. For more information, please contact [email protected]. A Functional Approach to Resolving the Biogeocomplexity of Two Extreme Environments by Haydn Rubelmann III A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Cell Biology, Microbiology and Molecular Biology College of Arts and Sciences University of South Florida Major Professor: James R. Garey, Ph.D. Randy Larsen, Ph.D. Kathleen Scott, Ph.D. David Merkler, Ph.D. Date of Approval: November 12, 2014 Keywords: environmental microbiology, extremophiles, shallow-water hydrothermal vents, anoxic marine pits Copyright © 2014, Haydn Rubelmann III DEDICATION I would like to dedicate this dissertation to three of my personal champions: my grandfather, Haydn Rubelmann Sr. (1929 - 2004), who encouraged me to pursue an academic career; my stepfather, Dale Jones (1954 - 2008), who was the best father anyone could ever hope for, and my husband, Eduardo Godoy, who suffered through not only 8 years of my doctoral tenure, but a grueling civil liberty injustice that almost wedged the Caribbean Sea between us.
    [Show full text]
  • Diversity Patterns and Activity of Uncultured Marine Heterotrophic Flagellates Unveiled with Pyrosequencing
    The ISME Journal (2012) 6, 1823–1833 & 2012 International Society for Microbial Ecology All rights reserved 1751-7362/12 www.nature.com/ismej ORIGINAL ARTICLE Diversity patterns and activity of uncultured marine heterotrophic flagellates unveiled with pyrosequencing Ramiro Logares1, Stephane Audic2,3, Sebastien Santini4, Massimo C Pernice1, Colomban de Vargas3 and Ramon Massana1 1Institut de Cie`ncies del Mar (CSIC), Passeig Marı´tim de la Barceloneta, Barcelona, Spain; 2CNRS, UMR 7144, Equipe Evolution du Plancton et Pale´o-Oce´ans, Roscoff, France; 3UPMC Univ Paris 06, UMR 7144, Adaptation et Diversite´ en Milieu Marin, Roscoff, France and 4CNRS, UMR 7256, Structural and Genomic Information Laboratory, Mediterranean Institute of Microbiology, Aix-Marseille University, Marseille, France Flagellated heterotrophic microeukaryotes have key roles for the functioning of marine ecosystems as they channel large amounts of organic carbon to the upper trophic levels and control the population sizes of bacteria and archaea. Still, we know very little on the diversity patterns of most groups constituting this evolutionary heterogeneous assemblage. Here, we investigate 11 groups of uncultured flagellates known as MArine STramenopiles (MASTs). MASTs are ecologically very important and branch at the base of stramenopiles. We explored the diversity patterns of MASTs using pyrosequencing (18S rDNA) in coastal European waters. We found that MAST groups range from highly to lowly diversified. Pyrosequencing (hereafter ‘454’) allowed us to approach to the limits of taxonomic diversity for all MAST groups, which varied in one order of magnitude (tens to hundreds) in terms of operational taxonomic units (98% similarity). We did not evidence large differences in activity, as indicated by ratios of DNA:RNA-reads.
    [Show full text]
  • 23.3 Groups of Protists
    Chapter 23 | Protists 639 cysts that are a protective, resting stage. Depending on habitat of the species, the cysts may be particularly resistant to temperature extremes, desiccation, or low pH. This strategy allows certain protists to “wait out” stressors until their environment becomes more favorable for survival or until they are carried (such as by wind, water, or transport on a larger organism) to a different environment, because cysts exhibit virtually no cellular metabolism. Protist life cycles range from simple to extremely elaborate. Certain parasitic protists have complicated life cycles and must infect different host species at different developmental stages to complete their life cycle. Some protists are unicellular in the haploid form and multicellular in the diploid form, a strategy employed by animals. Other protists have multicellular stages in both haploid and diploid forms, a strategy called alternation of generations, analogous to that used by plants. Habitats Nearly all protists exist in some type of aquatic environment, including freshwater and marine environments, damp soil, and even snow. Several protist species are parasites that infect animals or plants. A few protist species live on dead organisms or their wastes, and contribute to their decay. 23.3 | Groups of Protists By the end of this section, you will be able to do the following: • Describe representative protist organisms from each of the six presently recognized supergroups of eukaryotes • Identify the evolutionary relationships of plants, animals, and fungi within the six presently recognized supergroups of eukaryotes • Identify defining features of protists in each of the six supergroups of eukaryotes. In the span of several decades, the Kingdom Protista has been disassembled because sequence analyses have revealed new genetic (and therefore evolutionary) relationships among these eukaryotes.
    [Show full text]
  • Guéguen-2021-Lipid Droplets.P
    fpls-12-639276 April 19, 2021 Time: 10:44 # 1 REVIEW published: 22 April 2021 doi: 10.3389/fpls.2021.639276 Lipid Droplets in Unicellular Photosynthetic Stramenopiles Nolwenn Guéguen, Damien Le Moigne, Alberto Amato, Juliette Salvaing and Eric Maréchal* Laboratoire de Physiologie Cellulaire et Végétale, INRAE, CNRS, CEA, IRIG, CEA Grenoble, Université Grenoble Alpes, Grenoble, France The Heterokonta or Stramenopile phylum comprises clades of unicellular photosynthetic species, which are promising for a broad range of biotechnological applications, based on their capacity to capture atmospheric CO2 via photosynthesis and produce biomolecules of interest. These molecules include triacylglycerol (TAG) loaded inside specific cytosolic bodies, called the lipid droplets (LDs). Understanding TAG production and LD biogenesis and function in photosynthetic stramenopiles is therefore essential, and is mostly based on the study of a few emerging models, such as the pennate diatom Phaeodactylum tricornutum and eustigmatophytes, such as Nannochloropsis Edited by: and Microchloropsis species. The biogenesis of cytosolic LD usually occurs at the level Peter J. Lammers, of the endoplasmic reticulum. However, stramenopile cells contain a complex plastid Arizona State University, United States deriving from a secondary endosymbiosis, limited by four membranes, the outermost Reviewed by: Taraka Dale, one being connected to the endomembrane system. Recent cell imaging and proteomic Biosciences Division, Los Alamos studies suggest that at least some cytosolic LDs might be associated to the surface National Laboratory, United States of the complex plastid, via still uncharacterized contact sites. The carbon length and Inna Khozin-Goldberg, Ben-Gurion University of the Negev, number of double bonds of the acyl groups contained in the TAG molecules depend Israel on their origin.
    [Show full text]
  • Hydrothermal Activity and Water Mass Composition Shape Microbial Eukaryote Diversity and Biogeography in the Okinawa Trough Margaret Mars Brisbina, Asa E
    bioRxiv preprint doi: https://doi.org/10.1101/714816; this version posted July 25, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-ND 4.0 International license. Hydrothermal activity and water mass composition shape microbial eukaryote diversity and biogeography in the Okinawa Trough Margaret Mars Brisbina, Asa E. Conovera, Satoshi Mitaraia 5 a Marine Biophysics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan Correspondance M. Mars Brisbin, Marine Biophysics Unit, Okinawa Institute of Science and Technology 10 Graduate University, 1919-1 Tancha, Onna-son, Okinawa, Japan e-mail: [email protected] Abstract Microbial eukaryotes (protists) contribute substantially to ecological functioning in 15 marine ecosystems, but factors shaping protist diversity, such as dispersal barriers and environmental selection, remain difficult to parse. Deep-sea water masses, which form geographic barriers, and hydrothermal vents, which represent isolated productivity hotspots, are ideal opportunities for studying the effects of dispersal barriers and environmental selection on protist communities. The Okinawa Trough, a deep, back-arc 20 spreading basin, contains distinct water masses in the northern and southern regions and at least twenty-five active hydrothermal vents. In this study we used metabarcoding to characterize protistan communities from fourteen stations spanning the length of the Okinawa Trough, including three hydrothermal vent sites. Significant differences in community by region and water mass were present, and protist communities in 25 hydrothermally-influenced bottom-water were significantly different from communities in other bottom waters.
    [Show full text]