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Danovaro R, Levin LA, Fanelli G, Scenna L, Corinaldesi C. Microbes as marine habitat formers and ecosystem engineers. Nat Ecol Evol 2024; 8:1407-1419. [PMID: 38844822 DOI: 10.1038/s41559-024-02407-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 03/12/2024] [Indexed: 08/10/2024]
Abstract
Despite their small individual size, marine prokaryotic and eukaryotic microbes can form large 3D structures and complex habitats. These habitats contribute to seafloor heterogeneity, facilitating colonization by animals and protists. They also provide food and refuge for a variety of species and promote novel ecological interactions. Here we illustrate the role of microbes as ecosystem engineers and propose a classification based on five types of habitat: microbial mats, microbial forests, microbial-mineralized habitats, microbial outcrops and microbial nodules. We also describe the metabolic processes of microbial habitat formers and their ecological roles, highlighting current gaps in knowledge. Their biogeography indicates that these habitats are widespread in all oceans and are continuously being discovered across latitudes and depths. These habitats are also expected to expand under future global change owing to their ability to exploit extreme environmental conditions. Given their high ecological relevance and their role in supporting endemic species and high biodiversity levels, microbial habitats should be included in future spatial planning, conservation and management measures.
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Affiliation(s)
- Roberto Danovaro
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy.
- National Biodiversity Future Center, Palermo, Italy.
| | - Lisa A Levin
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, CA, USA
| | - Ginevra Fanelli
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Lorenzo Scenna
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Cinzia Corinaldesi
- National Biodiversity Future Center, Palermo, Italy.
- Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, Ancona, Italy.
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2
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Groups of Geomicrobiological Indicators Are Spread across Gas-Hydrate and Non-Gas-Hydrate Areas in the Northern Part of the Sea of Japan. BIOLOGY 2022; 11:biology11121802. [PMID: 36552312 PMCID: PMC9774978 DOI: 10.3390/biology11121802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/03/2022] [Accepted: 12/07/2022] [Indexed: 12/15/2022]
Abstract
The bioindication of oil and gas fields is a field of geomicrobiology that is mainly devoted to the detection of hydrocarbon-oxidizing microbial indicator species or functional genes in total DNA. However, it appears promising to use the physiological properties of microorganisms detection deposit type of hydrocarbons, in particular their ability to oxidize hydrocarbons under aerobic and anaerobic conditions. In this study, the most promising approach in this area was the method used for assessing the anaerobic degradation of hydrocarbons. When comparing molecular genetics and cultured methods of bioindication, it can be concluded that molecular biomarkers of functional genes for the anaerobic destruction of hydrocarbons (masD) make it possible to separate areas with traditional and gas-hydrate types of deposits. Using cultured methods, we found that representatives of the Nocardiaceae family of the phylum Actinomycetota were tied to the areas where gas hydrates were found. The ability of aerobic and facultative anaerobic hydrocarbon-oxidizing microorganisms to anaerobically utilize hydrocarbons was determined with cultured methods. For the first time, this ability was revealed for the genera Stenotrophomonas, Psychrobacter, Micrococcus and Peribacillus. The wide distribution of this ability that we found in strains isolated from both study regions suggests its prominent role in the destruction of hydrocarbons in marine sediments.
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3
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Dominance of Sulfurospirillum in Metagenomes Associated with the Methane Ice Worm (Sirsoe methanicola). Appl Environ Microbiol 2022; 88:e0029022. [PMID: 35867581 PMCID: PMC9365241 DOI: 10.1128/aem.00290-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Sirsoe methanicola, commonly known as the methane ice worm, is the only macrofaunal species known to inhabit the Gulf of Mexico methane hydrates. Little is known about this elusive marine polychaete that can colonize rich carbon and energy reserves. Metagenomic analysis of gut contents and worm fragments predicted diverse metabolic capabilities with the ability to utilize a range of nitrogen, sulfur, and organic carbon compounds through microbial taxa affiliated with Campylobacterales, Desulfobacterales, Enterobacterales, SAR324, Alphaproteobacteria, and Mycoplasmatales. Entomoplasmatales and Chitinivibrionales were additionally identified from extracted full-length 16S rRNA sequences, and read analysis identified 196 bacterial families. Overall, the microbial community appeared dominated by uncultured Sulfurospirillum, a taxon previously considered free-living rather than host-associated. Metagenome-assembled genomes (MAGs) classified as uncultured Sulfurospirillum predicted thiosulfate disproportionation and the reduction of tetrathionate, sulfate, sulfide/polysulfide, and nitrate. Microbial amino acid and vitamin B12 biosynthesis genes were identified in multiple MAGs, suggesting nutritional value to the host. Reads assigned to aerobic or anaerobic methanotrophic taxa were rare. IMPORTANCE Methane hydrates represent vast reserves of natural gas with roles in global carbon cycling and climate change. This study provided the first analysis of metagenomes associated with Sirsoe methanicola, the only polychaete species known to colonize methane hydrates. Previously unrecognized participation of Sulfurospirillum in a gut microbiome is provided, and the role of sulfur compound redox reactions within this community is highlighted. The comparative biology of S. methanicola is of general interest given research into the adverse effects of sulfide production in human gut microbiomes. In addition, taxonomic assignments are provided for nearly 200 bacterial families, expanding our knowledge of microbiomes in the deep sea.
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Cold Seeps on the Passive Northern U.S. Atlantic Margin Host Globally Representative Members of the Seep Microbiome with Locally Dominant Strains of Archaea. Appl Environ Microbiol 2022; 88:e0046822. [PMID: 35607968 DOI: 10.1128/aem.00468-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Marine cold seeps are natural sites of methane emission and harbor distinct microbial communities capable of oxidizing methane. The majority of known cold seeps are on tectonically active continental margins, but recent discoveries have revealed abundant seeps on passive margins as well, including on the U.S. Atlantic Margin (USAM). We sampled in and around four USAM seeps and combined pore water geochemistry measurements with amplicon sequencing of 16S rRNA and mcrA (DNA and RNA) to investigate the microbial communities present, their assembly processes, and how they compare to communities at previously studied sites. We found that the USAM seeps contained communities consistent with the canonical seep microbiome at the class and order levels but differed markedly at the sequence variant level, especially within the anaerobic methanotrophic (ANME) archaea. The ANME populations were highly uneven, with just a few dominant mcrA sequence variants at each seep. Interestingly, the USAM seeps did not form a distinct phylogenetic cluster when compared with other previously described seeps around the world. Consistent with this, we found only a very weak (though statistically significant) distance-decay trend in seep community similarity across a global data set. Ecological assembly indices suggest that the USAM seep communities were assembled primarily deterministically, in contrast to the surrounding nonseep sediments, where stochastic processes dominated. Together, our results suggest that the primary driver of seep microbial community composition is local geochemistry-specifically methane, sulfide, nitrate, acetate, and ammonium concentrations-rather than the geologic context, the composition of nearby seeps, or random events of dispersal. IMPORTANCE Cold seeps are now known to be widespread features of passive continental margins, including the northern U.S. Atlantic Margin (USAM). Methane seepage is expected to intensify at these relatively shallow seeps as bottom waters warm and underlying methane hydrates dissociate. While methanotrophic microbial communities might reduce or prevent methane release, microbial communities on passive margins have rarely been characterized. In this study, we investigated the Bacteria and Archaea at four cold seeps on the northern USAM and found that despite being colocated on the same continental slope, the communities significantly differ by site at the sequence variant level, particularly methane-cycling community members. Differentiation by site was not observed in similarly spaced background sediments, raising interesting questions about the dispersal pathways of cold seep microorganisms. Understanding the genetic makeup of these discrete seafloor ecosystems and how their microbial communities develop will be increasingly important as the climate changes.
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Chen SC, Ji J, Popp D, Jaekel U, Richnow HH, Sievert SM, Musat F. Genome and proteome analyses show the gaseous alkane degrader Desulfosarcina sp. strain BuS5 as an extreme metabolic specialist. Environ Microbiol 2022; 24:1964-1976. [PMID: 35257474 DOI: 10.1111/1462-2920.15956] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/23/2022] [Indexed: 11/30/2022]
Abstract
The metabolic potential of the sulfate-reducing bacterium Desulfosarcina sp. strain BuS5, currently the only pure culture able to oxidize the volatile alkanes propane and butane without oxygen, was investigated via genomics, proteomics and physiology assays. Complete genome sequencing revealed that strain BuS5 encodes a single alkyl-succinate synthase, an enzyme which apparently initiates oxidation of both propane and butane. The formed alkyl-succinates are oxidized to CO2 via beta oxidation and the oxidative Wood-Ljungdahl pathways as shown by proteogenomics analyses. Strain BuS5 conserves energy via the canonical sulfate reduction pathway and electron bifurcation. An ability to utilize long-chain fatty acids, mannose and oligopeptides, suggested by automated annotation pipelines, was not supported by physiology assays and in-depth analyses of the corresponding genetic systems. Consistently, comparative genomics revealed a streamlined BuS5 genome with a remarkable paucity of catabolic modules. These results establish strain BuS5 as an exceptional metabolic specialist, able to grow only with propane and butane, for which we propose the name Desulfosarcina aeriophaga BuS5. This highly restrictive lifestyle, most likely the result of habitat-driven evolutionary gene loss, may provide D. aeriophaga BuS5 a competitive edge in sediments impacted by natural gas seeps. Etymology: Desulfosarcina aeriophaga, aério (Greek): gas; phágos (Greek): eater; D. aeriophaga: a gas eating or gas feeding Desulfosarcina.
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Affiliation(s)
- Song-Can Chen
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Jiaheng Ji
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | | | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Florin Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania
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6
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Pereira OS, Gonzalez J, Mendoza GF, Le J, Coscino CL, Lee RW, Cortés J, Cordes EE, Levin LA. The dynamic influence of methane seepage on macrofauna inhabiting authigenic carbonates. Ecosphere 2021. [DOI: 10.1002/ecs2.3744] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Olívia S. Pereira
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
| | - Jennifer Gonzalez
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
| | - Guillermo F. Mendoza
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
| | - Jennifer Le
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
| | - Connor L. Coscino
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
| | - Raymond W. Lee
- School of Biological Sciences Washington State University Pullman Washington USA
| | - Jorge Cortés
- Centro de Investigación en Ciencias del Mar y Limnología Universidad de Costa Rica San José Costa Rica
| | - Erik E. Cordes
- Department of Biology Temple University Philadelphia Pennsylvania USA
| | - Lisa A. Levin
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation Scripps Institution of Oceanography University of California San Diego San Diego California USA
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7
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Expanding the repertoire of electron acceptors for the anaerobic oxidation of methane in carbonates in the Atlantic and Pacific Ocean. THE ISME JOURNAL 2021; 15:2523-2536. [PMID: 33712702 PMCID: PMC8397759 DOI: 10.1038/s41396-021-00918-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 01/21/2021] [Accepted: 01/29/2021] [Indexed: 01/31/2023]
Abstract
Authigenic carbonates represent a significant microbial sink for methane, yet little is known about the microbiome responsible for the methane removal. We identify carbonate microbiomes distributed over 21 locations hosted by seven different cold seeps in the Pacific and Atlantic Oceans by carrying out a gene-based survey using 16S rRNA- and mcrA gene sequencing coupled with metagenomic analyses. Based on 16S rRNA gene amplicon analyses, these sites were dominated by bacteria affiliated to the Firmicutes, Alpha- and Gammaproteobacteria. ANME-1 and -2 archaeal clades were abundant in the carbonates yet their typical syntrophic partners, sulfate-reducing bacteria, were not significantly present. Based on mcrA amplicon analyses, the Candidatus Methanoperedens clades were also highly abundant. Our metagenome analysis indicated that methane oxidizers affiliated to the ANME-1 and -2, may be capable of performing complete methane- and potentially short-chain alkane oxidation independently using oxidized sulfur and nitrogen compounds as terminal electron acceptors. Gammaproteobacteria are hypothetically capable of utilizing oxidized nitrogen compounds and may be involved in syntrophy with methane-oxidizing archaea. Carbonate structures represent a window for a more diverse utilization of electron acceptors for anaerobic methane oxidation along the Atlantic and Pacific Margin.
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8
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Marlow JJ, Hoer D, Jungbluth SP, Reynard LM, Gartman A, Chavez MS, El-Naggar MY, Tuross N, Orphan VJ, Girguis PR. Carbonate-hosted microbial communities are prolific and pervasive methane oxidizers at geologically diverse marine methane seep sites. Proc Natl Acad Sci U S A 2021; 118:e2006857118. [PMID: 34161255 PMCID: PMC8237665 DOI: 10.1073/pnas.2006857118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
At marine methane seeps, vast quantities of methane move through the shallow subseafloor, where it is largely consumed by microbial communities. This process plays an important role in global methane dynamics, but we have yet to identify all of the methane sinks in the deep sea. Here, we conducted a continental-scale survey of seven geologically diverse seafloor seeps and found that carbonate rocks from all sites host methane-oxidizing microbial communities with substantial methanotrophic potential. In laboratory-based mesocosm incubations, chimney-like carbonates from the newly described Point Dume seep off the coast of Southern California exhibited the highest rates of anaerobic methane oxidation measured to date. After a thorough analysis of physicochemical, electrical, and biological factors, we attribute this substantial metabolic activity largely to higher cell density, mineral composition, kinetic parameters including an elevated Vmax, and the presence of specific microbial lineages. Our data also suggest that other features, such as electrical conductance, rock particle size, and microbial community alpha diversity, may influence a sample's methanotrophic potential, but these factors did not demonstrate clear patterns with respect to methane oxidation rates. Based on the apparent pervasiveness within seep carbonates of microbial communities capable of performing anaerobic oxidation of methane, as well as the frequent occurrence of carbonates at seeps, we suggest that rock-hosted methanotrophy may be an important contributor to marine methane consumption.
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Affiliation(s)
- Jeffrey J Marlow
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138;
| | - Daniel Hoer
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Sean P Jungbluth
- Department of Energy, Joint Genome Institute, Walnut Creek, CA 94720
| | - Linda M Reynard
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Amy Gartman
- US Geological Survey Pacific Coastal and Marine Science Center, Santa Cruz, CA 95060
| | - Marko S Chavez
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089
| | - Noreen Tuross
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138;
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9
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Leprich DJ, Flood BE, Schroedl PR, Ricci E, Marlow JJ, Girguis PR, Bailey JV. Sulfur bacteria promote dissolution of authigenic carbonates at marine methane seeps. ISME JOURNAL 2021; 15:2043-2056. [PMID: 33574572 PMCID: PMC8245480 DOI: 10.1038/s41396-021-00903-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 12/21/2020] [Accepted: 01/20/2021] [Indexed: 01/04/2023]
Abstract
Carbonate rocks at marine methane seeps are commonly colonized by sulfur-oxidizing bacteria that co-occur with etch pits that suggest active dissolution. We show that sulfur-oxidizing bacteria are abundant on the surface of an exemplar seep carbonate collected from Del Mar East Methane Seep Field, USA. We then used bioreactors containing aragonite mineral coupons that simulate certain seep conditions to investigate plausible in situ rates of carbonate dissolution associated with sulfur-oxidizing bacteria. Bioreactors inoculated with a sulfur-oxidizing bacterial strain, Celeribacter baekdonensis LH4, growing on aragonite coupons induced dissolution rates in sulfidic, heterotrophic, and abiotic conditions of 1773.97 (±324.35), 152.81 (±123.27), and 272.99 (±249.96) μmol CaCO3 • cm−2 • yr−1, respectively. Steep gradients in pH were also measured within carbonate-attached biofilms using pH-sensitive fluorophores. Together, these results show that the production of acidic microenvironments in biofilms of sulfur-oxidizing bacteria are capable of dissolving carbonate rocks, even under well-buffered marine conditions. Our results support the hypothesis that authigenic carbonate rock dissolution driven by lithotrophic sulfur-oxidation constitutes a previously unknown carbon flux from the rock reservoir to the ocean and atmosphere.
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Affiliation(s)
- Dalton J Leprich
- Department of Earth and Environmental Sciences, University of Minnesota Twin-Cities, Minneapolis, MN, 55455, USA.
| | - Beverly E Flood
- Department of Earth and Environmental Sciences, University of Minnesota Twin-Cities, Minneapolis, MN, 55455, USA
| | - Peter R Schroedl
- Department of Earth and Environmental Sciences, University of Minnesota Twin-Cities, Minneapolis, MN, 55455, USA
| | - Elizabeth Ricci
- Department of Earth and Environmental Sciences, University of Minnesota Twin-Cities, Minneapolis, MN, 55455, USA
| | - Jeffery J Marlow
- Department of Biology, Boston University, Boston, MA, 02215, USA
| | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA
| | - Jake V Bailey
- Department of Earth and Environmental Sciences, University of Minnesota Twin-Cities, Minneapolis, MN, 55455, USA.
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10
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Metcalfe KS, Murali R, Mullin SW, Connon SA, Orphan VJ. Experimentally-validated correlation analysis reveals new anaerobic methane oxidation partnerships with consortium-level heterogeneity in diazotrophy. THE ISME JOURNAL 2021; 15:377-396. [PMID: 33060828 PMCID: PMC8027057 DOI: 10.1038/s41396-020-00757-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 07/28/2020] [Accepted: 08/21/2020] [Indexed: 02/08/2023]
Abstract
Archaeal anaerobic methanotrophs ("ANME") and sulfate-reducing Deltaproteobacteria ("SRB") form symbiotic multicellular consortia capable of anaerobic methane oxidation (AOM), and in so doing modulate methane flux from marine sediments. The specificity with which ANME associate with particular SRB partners in situ, however, is poorly understood. To characterize partnership specificity in ANME-SRB consortia, we applied the correlation inference technique SparCC to 310 16S rRNA amplicon libraries prepared from Costa Rica seep sediment samples, uncovering a strong positive correlation between ANME-2b and members of a clade of Deltaproteobacteria we termed SEEP-SRB1g. We confirmed this association by examining 16S rRNA diversity in individual ANME-SRB consortia sorted using flow cytometry and by imaging ANME-SRB consortia with fluorescence in situ hybridization (FISH) microscopy using newly-designed probes targeting the SEEP-SRB1g clade. Analysis of genome bins belonging to SEEP-SRB1g revealed the presence of a complete nifHDK operon required for diazotrophy, unusual in published genomes of ANME-associated SRB. Active expression of nifH in SEEP-SRB1g within ANME-2b-SEEP-SRB1g consortia was then demonstrated by microscopy using hybridization chain reaction (HCR-) FISH targeting nifH transcripts and diazotrophic activity was documented by FISH-nanoSIMS experiments. NanoSIMS analysis of ANME-2b-SEEP-SRB1g consortia incubated with a headspace containing CH4 and 15N2 revealed differences in cellular 15N-enrichment between the two partners that varied between individual consortia, with SEEP-SRB1g cells enriched in 15N relative to ANME-2b in one consortium and the opposite pattern observed in others, indicating both ANME-2b and SEEP-SRB1g are capable of nitrogen fixation, but with consortium-specific variation in whether the archaea or bacterial partner is the dominant diazotroph.
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Affiliation(s)
- Kyle S Metcalfe
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E California Blvd, Mail Code 170-25, Pasadena, CA, 91125, USA.
| | - Ranjani Murali
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E California Blvd, Mail Code 170-25, Pasadena, CA, 91125, USA
| | - Sean W Mullin
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E California Blvd, Mail Code 170-25, Pasadena, CA, 91125, USA
| | - Stephanie A Connon
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E California Blvd, Mail Code 170-25, Pasadena, CA, 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E California Blvd, Mail Code 170-25, Pasadena, CA, 91125, USA.
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11
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Mullin SW, Wanger G, Kruger BR, Sackett JD, Hamilton-Brehm SD, Bhartia R, Amend JP, Moser DP, Orphan VJ. Patterns of in situ Mineral Colonization by Microorganisms in a ~60°C Deep Continental Subsurface Aquifer. Front Microbiol 2020; 11:536535. [PMID: 33329414 PMCID: PMC7711152 DOI: 10.3389/fmicb.2020.536535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 09/24/2020] [Indexed: 11/13/2022] Open
Abstract
The microbial ecology of the deep biosphere is difficult to characterize, owing in part to sampling challenges and poorly understood response mechanisms to environmental change. Pre-drilled wells, including oil wells or boreholes, offer convenient access, but sampling is frequently limited to the water alone, which may provide only a partial view of the native diversity. Mineral heterogeneity demonstrably affects colonization by deep biosphere microorganisms, but the connections between the mineral-associated and planktonic communities remain unclear. To understand the substrate effects on microbial colonization and the community response to changes in organic carbon, we conducted an 18-month series of in situ experiments in a warm (57°C), anoxic, fractured carbonate aquifer at 752 m depth using replicate open, screened cartridges containing different solid substrates, with a proteinaceous organic matter perturbation halfway through this series. Samples from these cartridges were analyzed microscopically and by Illumina (iTag) 16S rRNA gene libraries to characterize changes in mineralogy and the diversity of the colonizing microbial community. The substrate-attached and planktonic communities were significantly different in our data, with some taxa (e.g., Candidate Division KB-1) rare or undetectable in the first fraction and abundant in the other. The substrate-attached community composition also varied significantly with mineralogy, such as with two Rhodocyclaceae OTUs, one of which was abundant on carbonate minerals and the other on silicic substrates. Secondary sulfide mineral formation, including iron sulfide framboids, was observed on two sets of incubated carbonates. Notably, microorganisms were attached to the framboids, which were correlated with abundant Sulfurovum and Desulfotomaculum sp. sequences in our analysis. Upon organic matter perturbation, mineral-associated microbial diversity differences were temporarily masked by the dominance of putative heterotrophic taxa in all samples, including OTUs identified as Caulobacter, Methyloversatilis, and Pseudomonas. Subsequent experimental deployments included a methanogen-dominated stage (Methanobacteriales and Methanomicrobiales) 6 months after the perturbation and a return to an assemblage similar to the pre-perturbation community after 9 months. Substrate-associated community differences were again significant within these subsequent phases, however, demonstrating the value of in situ time course experiments to capture a fraction of the microbial assemblage that is frequently difficult to observe in pre-drilled wells.
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Affiliation(s)
- Sean W Mullin
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Greg Wanger
- Jet Propulsion Laboratory, Pasadena, CA, United States
| | - Brittany R Kruger
- Department of Microbiology, Southern Illinois University Carbondale, Carbondale, IL, United States
| | - Joshua D Sackett
- Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV, United States
| | - Scott D Hamilton-Brehm
- Department of Microbiology, Southern Illinois University Carbondale, Carbondale, IL, United States
| | - Rohit Bhartia
- Jet Propulsion Laboratory, Pasadena, CA, United States
| | - Jan P Amend
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, United States
| | - Duane P Moser
- Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV, United States
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
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12
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Jones DS, Johnson NW, Mitchell CPJ, Walker GM, Bailey JV, Pastor J, Swain EB. Diverse Communities of hgcAB+ Microorganisms Methylate Mercury in Freshwater Sediments Subjected to Experimental Sulfate Loading. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14265-14274. [PMID: 33138371 DOI: 10.1021/acs.est.0c02513] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Methylmercury (MeHg) is a bioaccumulative neurotoxin produced by certain sulfate-reducing bacteria and other anaerobic microorganisms. Because microorganisms differ in their capacity to methylate mercury, the abundance and distribution of methylating populations may determine MeHg production in the environment. We compared rates of MeHg production and the distribution of hgcAB genes in epilimnetic sediments from a freshwater lake that were experimentally amended with sulfate levels from 7 to 300 mg L-1. The most abundant hgcAB sequences were associated with clades of Methanomicrobia, sulfate-reducing Deltaproteobacteria, Spirochaetes, and unknown environmental sequences. The hgcAB+ communities from higher sulfate amendments were less diverse and had relatively more Deltaproteobacteria, whereas the communities from lower amendments were more diverse with a larger proportion of hgcAB sequences affiliated with other clades. Potential methylation rate constants varied 52-fold across the experiment. Both potential methylation rate constants and % MeHg were the highest in sediments from the lowest sulfate amendments, which had the most diverse hgcAB+ communities and relatively fewer hgcAB genes from clades associated with sulfate reduction. Although pore water sulfide concentration covaried with hgcAB diversity across our experimental sulfate gradient, major changes in the community of hgcAB+ organisms occurred prior to a significant buildup of sulfide in pore waters. Our results indicate that methylating communities dominated by diverse anaerobic microorganisms that do not reduce sulfate can produce MeHg as effectively as communities dominated by sulfate-reducing populations.
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Affiliation(s)
- Daniel S Jones
- BioTechnology Institute, University of Minnesota, Saint Paul 55108, Minnesota, United States
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis 55455, Minnesota, United States
- Department of Earth and Environmental Science, New Mexico Institute of Mining and Technology, Socorro 87801, New Mexico, United States
- National Cave and Karst Research Institute, Carlsbad, New Mexico 88220, United States
| | - Nathan W Johnson
- Department of Civil Engineering, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Carl P J Mitchell
- Department of Physical and Environmental Sciences, University of Toronto-Scarborough, Toronto, Ontario M1C 1A4, Canada
| | - Gabriel M Walker
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis 55455, Minnesota, United States
| | - Jake V Bailey
- Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis 55455, Minnesota, United States
| | - John Pastor
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Edward B Swain
- Minnesota Pollution Control Agency, Saint Paul, Minnesota 55155, United States
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13
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Dean RK, Schneider CR, Almnehlawi HS, Dawson KS, Fennell DE. 2,3,7,8-Tetrachlorodibenzo- p-dioxin Dechlorination is Differentially Enhanced by Dichlorobenzene Amendment in Passaic River, NJ Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:8380-8389. [PMID: 32432863 DOI: 10.1021/acs.est.0c00876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Polychlorinated dibenzo-p-dioxins (PCDDs) are a class of toxic organic compounds released by a number of industrial processes. Sediments of the Passaic River in New Jersey are contaminated by these compounds. To explore the ability of native organohalide respiring bacteria to dechlorinate PCDDs, we first enriched bacteria from sediments of the Passaic River on two organohalides, trichloroethene (TCE) and 1,2-dichlorobenzene (DCB). We then used these enriched sediment cultures and original, unamended sediment as the inocula in a secondary experiment with 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TeCDD), 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TeCDD), and 2,7-dichlorodibenzo-p-dioxin (2,7-DiCDD) as target organohalides. We observed dechlorination of 1,2,3,4-TeCDD by all inocula, although to different extents. We observed progressive dechlorination of 2,3,7,8-TeCDD only in bottles inoculated with the DCB enrichment culture, and dechlorination of 2,7-DiCDD almost exclusively in bottles inoculated with the original, unamended river sediment. Dechlorination of 1,2,3,4-TeCDD was more rapid than that of the other amended congeners. Phylotypes within the class Dehalococcoidia associated with organohalide dechlorination were differentially enriched in DCB versus TCE enrichment cultures, indicating that they may play a role in dechlorination of the PCDDs.
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Affiliation(s)
- Rachel K Dean
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Cassidy R Schneider
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Haider S Almnehlawi
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
- College of Science, Al-Muthanna University, Samawah, AL-Muthanna 66001 Iraq
| | - Katherine S Dawson
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Donna E Fennell
- Department of Environmental Sciences, Rutgers University, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
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14
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Abstract
The marine subsurface is one of the largest habitats on Earth composed exclusively of microorganisms and harboring on the order of 1029 microbial cells. It is unclear if deep subsurface life impacts overlying seafloor diversity and biogeochemical cycling in the deep ocean. We analyzed the microbial communities of 172 seafloor surface sediment samples, including gas and oil seeps as well as sediments not subject to upward fluid flow. A strong correlation between typical subsurface clades and active geofluid seepage suggests that subsurface life is injected into the deep ocean floor at hydrocarbon seeps, a globally widespread hydrogeological phenomenon. This supply of subsurface-derived microbial populations, biomass, and metabolic potential thus increases biodiversity and impacts carbon cycling in the deep ocean. Marine cold seeps transmit fluids between the subseafloor and seafloor biospheres through upward migration of hydrocarbons that originate in deep sediment layers. It remains unclear how geofluids influence the composition of the seabed microbiome and if they transport deep subsurface life up to the surface. Here we analyzed 172 marine surficial sediments from the deep-water Eastern Gulf of Mexico to assess whether hydrocarbon fluid migration is a mechanism for upward microbial dispersal. While 132 of these sediments contained migrated liquid hydrocarbons, evidence of continuous advective transport of thermogenic alkane gases was observed in 11 sediments. Gas seeps harbored distinct microbial communities featuring bacteria and archaea that are well-known inhabitants of deep biosphere sediments. Specifically, 25 distinct sequence variants within the uncultivated bacterial phyla Atribacteria and Aminicenantes and the archaeal order Thermoprofundales occurred in significantly greater relative sequence abundance along with well-known seep-colonizing members of the bacterial genus Sulfurovum, in the gas-positive sediments. Metabolic predictions guided by metagenome-assembled genomes suggested these organisms are anaerobic heterotrophs capable of nonrespiratory breakdown of organic matter, likely enabling them to inhabit energy-limited deep subseafloor ecosystems. These results point to petroleum geofluids as a vector for the advection-assisted upward dispersal of deep biosphere microbes from subsurface to surface environments, shaping the microbiome of cold seep sediments and providing a general mechanism for the maintenance of microbial diversity in the deep sea.
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15
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Bird LR, Dawson KS, Chadwick GL, Fulton JM, Orphan VJ, Freeman KH. Carbon isotopic heterogeneity of coenzyme F430 and membrane lipids in methane-oxidizing archaea. GEOBIOLOGY 2019; 17:611-627. [PMID: 31364272 DOI: 10.1111/gbi.12354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 06/17/2019] [Accepted: 06/23/2019] [Indexed: 06/10/2023]
Abstract
Archaeal ANaerobic MEthanotrophs (ANME) facilitate the anaerobic oxidation of methane (AOM), a process that is believed to proceed via the reversal of the methanogenesis pathway. Carbon isotopic composition studies indicate that ANME are metabolically diverse and able to assimilate metabolites including methane, methanol, acetate, and dissolved inorganic carbon (DIC). Our data support the interpretation that ANME in marine sediments at methane seeps assimilate both methane and DIC, and the carbon isotopic compositions of the tetrapyrrole coenzyme F430 and the membrane lipids archaeol and hydroxy-archaeol reflect their relative proportions of carbon from these substrates. Methane is assimilated via the methyl group of CH3 -tetrahydromethanopterin (H4 MPT) and DIC from carboxylation reactions that incorporate free intracellular DIC. F430 was enriched in 13 C (mean δ13 C = -27‰ for Hydrate Ridge and -80‰ for the Santa Monica Basin) compared to the archaeal lipids (mean δ13 C = -97‰ for Hydrate Ridge and -122‰ for the Santa Monica Basin). We propose that depending on the side of the tricarboxylic acid (TCA) cycle used to synthesize F430, its carbon was derived from 76% DIC and 24% methane via the reductive side or 57% DIC and 43% methane via the oxidative side. ANME lipids are predicted to contain 42% DIC and 58% methane, reflecting the amount of each assimilated into acetyl-CoA. With isotope models that include variable fractionation during biosynthesis for different carbon substrates, we show the estimated amounts of DIC and methane can result in carbon isotopic compositions of - 73‰ to - 77‰ for F430 and - 105‰ for archaeal lipids, values close to those for Santa Monica Basin. The F430 δ13 C value for Hydrate Ridge was 13 C-enriched compared with the modeled value, suggesting there is divergence from the predicted two carbon source models.
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Affiliation(s)
- Laurence R Bird
- Department of Geosciences, the Pennsylvania State University, University Park, PA, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Katherine S Dawson
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Grayson L Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - James M Fulton
- Department of Geosciences, the Pennsylvania State University, University Park, PA, USA
- Department of Geosciences, Baylor University, Waco, TX, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Katherine H Freeman
- Department of Geosciences, the Pennsylvania State University, University Park, PA, USA
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16
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Endolithic Microbial Habitats Hosted in Carbonate Nodules Currently Forming within Sediment at a High Methane Flux Site in the Sea of Japan. GEOSCIENCES 2019. [DOI: 10.3390/geosciences9110463] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Concretionary carbonates in deep-sea methane seep fields are formed as a result of microbial methane degradation, called anaerobic oxidation of methane (AOM). Recently, active microorganisms, including anaerobic methanotrophic archaea, were discovered from methane seep-associated carbonate outcroppings on the seafloor. However sedimentary buried carbonate nodules are a hitherto unknown microbial habitat. In this study, we investigated the microbial community structures in two carbonate nodules collected from a high methane flux site in a gas hydrate field off the Oki islands in the Sea of Japan. The nodules were formed around sulfate-methane interfaces (SMI) corresponding to 0.7 and 2.2 m below the seafloor. Based on a geochemical analysis, light carbon isotopic values ranging from −54.91‰ to −37.32‰ were found from the nodules collected at the shallow SMI depth, which were attributed to the high contributions of AOM-induced carbonate precipitation. Signatures of methanotrophic archaeal populations within the sedimentary buried nodule were detected based on microbial community composition analyses and quantitative real-time PCR targeted 16S rRNA, and functional genes for AOM. These results suggest that the buried carbonate nodule currently develops AOM-related microbial communities, and grows depending on the continued AOM under high methane flux conditions.
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17
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Chen SC, Musat N, Lechtenfeld OJ, Paschke H, Schmidt M, Said N, Popp D, Calabrese F, Stryhanyuk H, Jaekel U, Zhu YG, Joye SB, Richnow HH, Widdel F, Musat F. Anaerobic oxidation of ethane by archaea from a marine hydrocarbon seep. Nature 2019; 568:108-111. [PMID: 30918404 DOI: 10.1038/s41586-019-1063-0] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/27/2019] [Indexed: 11/09/2022]
Abstract
Ethane is the second most abundant component of natural gas in addition to methane, and-similar to methane-is chemically unreactive. The biological consumption of ethane under anoxic conditions was suggested by geochemical profiles at marine hydrocarbon seeps1-3, and through ethane-dependent sulfate reduction in slurries4-7. Nevertheless, the microorganisms and reactions that catalyse this process have to date remained unknown8. Here we describe ethane-oxidizing archaea that were obtained by specific enrichment over ten years, and analyse these archaea using phylogeny-based fluorescence analyses, proteogenomics and metabolite studies. The co-culture, which oxidized ethane completely while reducing sulfate to sulfide, was dominated by an archaeon that we name 'Candidatus Argoarchaeum ethanivorans'; other members were sulfate-reducing Deltaproteobacteria. The genome of Ca. Argoarchaeum contains all of the genes that are necessary for a functional methyl-coenzyme M reductase, and all subunits were detected in protein extracts. Accordingly, ethyl-coenzyme M (ethyl-CoM) was identified as an intermediate by liquid chromatography-tandem mass spectrometry. This indicated that Ca. Argoarchaeum initiates ethane oxidation by ethyl-CoM formation, analogous to the recently described butane activation by 'Candidatus Syntrophoarchaeum'9. Proteogenomics further suggests that oxidation of intermediary acetyl-CoA to CO2 occurs through the oxidative Wood-Ljungdahl pathway. The identification of an archaeon that uses ethane (C2H6) fills a gap in our knowledge of microorganisms that specifically oxidize members of the homologous alkane series (CnH2n+2) without oxygen. Detection of phylogenetic and functional gene markers related to those of Ca. Argoarchaeum at deep-sea gas seeps10-12 suggests that archaea that are able to oxidize ethane through ethyl-CoM are widespread members of the local communities fostered by venting gaseous alkanes around these seeps.
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Affiliation(s)
- Song-Can Chen
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Niculina Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Oliver J Lechtenfeld
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Heidrun Paschke
- Department of Analytical Chemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Matthias Schmidt
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Nedal Said
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Federica Calabrese
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ulrike Jaekel
- Max Planck Institute for Marine Microbiology, Bremen, Germany.,Department for Research Infrastructures, The Research Council of Norway, Oslo, Norway
| | - Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China.,Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Samantha B Joye
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | | | - Florin Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany. .,Max Planck Institute for Marine Microbiology, Bremen, Germany.
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18
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Pasulka A, Hu SK, Countway PD, Coyne KJ, Cary SC, Heidelberg KB, Caron DA. SSU-rRNA Gene Sequencing Survey of Benthic Microbial Eukaryotes from Guaymas Basin Hydrothermal Vent. J Eukaryot Microbiol 2019; 66:637-653. [PMID: 30620427 DOI: 10.1111/jeu.12711] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/09/2018] [Accepted: 12/16/2018] [Indexed: 12/21/2022]
Abstract
Microbial eukaryotes have important roles in marine food webs, but their diversity and activities in hydrothermal vent ecosystems are poorly characterized. In this study, we analyzed microbial eukaryotic communities associated with bacterial (Beggiatoa) mats in the 2,000 m deep-sea Guaymas Basin hydrothermal vent system using 18S rRNA gene high-throughput sequencing of the V4 region. We detected 6,954 distinct Operational Taxonomic Units (OTUs) across various mat systems. Of the sequences that aligned with known protistan phylotypes, most were affiliated with alveolates (especially dinoflagellates and ciliates) and cercozoans. OTU richness and community structure differed among sediment habitats (e.g. different mat types and cold sediments away from mats). Additionally, full-length 18S rRNA genes amplified and cloned from single cells revealed the identities of some of the most commonly encountered, active ciliates in this hydrothermal vent ecosystem. Observations and experiments were also conducted to demonstrate that ciliates were trophically active and ingesting fluorescent bacteria or Beggiatoa trichomes. Our work suggests that the active and diverse protistan community at the Guaymas Basin hydrothermal vent ecosystem likely consumes substantial amounts of bacterial biomass, and that the different habitats, often defined by distances of just a few 10s of cm, select for particular assemblages and levels of diversity.
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Affiliation(s)
- Alexis Pasulka
- Biological Sciences Department, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, California, USA
| | - Sarah K Hu
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - Peter D Countway
- Bigelow Laboratory for Ocean Sciences, 60 Bigelow Drive, East Boothbay, Maine, USA
| | - Kathryn J Coyne
- College of Earth, Ocean, and Environment, University of Delaware, 700 Pilottown Road, Lewes, Delaware, USA
| | - Stephen C Cary
- Department of Biological Sciences, The University of Waikato, Private Bag 3105, Hamilton, New Zealand
| | - Karla B Heidelberg
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, 3616 Trousdale Parkway, AHF 301 Los Angeles, Los Angeles, California, USA
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19
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Cui H, Su X, Chen F, Holland M, Yang S, Liang J, Su P, Dong H, Hou W. Microbial diversity of two cold seep systems in gas hydrate-bearing sediments in the South China Sea. MARINE ENVIRONMENTAL RESEARCH 2019; 144:230-239. [PMID: 30732863 DOI: 10.1016/j.marenvres.2019.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/29/2018] [Accepted: 01/14/2019] [Indexed: 05/05/2023]
Abstract
Cold seep is a unique habitat for microorganisms in deep marine sediments, and microbial communities and biogeochemical processes are still poorly understood, especially in relation to hydrate-bearing geo-systems. In this study, two cold seep systems were sampled and microbial diversity was studied at Site GMGS2-08 in the northern part of the South China Sea (SCS) during the GMGS2 gas hydrate expedition. The current cold seep system was composed of a sulfate methane transition zone (SMTZ) and an upper gas hydrate zone (UGHZ). The buried cold seep system was composed of an authigenic carbonate zone (ACZ) and a lower gas hydrate zone (LGHZ). These drill core samples provided an excellent opportunity for analyzing the microbial abundance and diversity based on quantitative polymerase chain reaction (qPCR) and high-throughput 16S rRNA gene sequencing. Compared to previous studies, the high relative abundance of ANME-1b, a clade of anaerobic methanotrophic archaea (ANME), may perform anaerobic oxidation of methane (AOM) in collaboration with ANME-2c and Desulfobacteraceae in the SMTZ, and the high relative abundances of Hadesarchaea, ANME-1b archaea and Aerophobetes bacteria were found in the gas hydrate zone (GHZ) at Site GMGS2-08. ANME-1b, detected in the GHZ, might mainly mediate the AOM process, and the process might occur in a wide depth range within the LGHZ. Moreover, bacterial communities were significantly different between the GHZ and non-GHZ sediments. In the ACZ, archaeal communities were different between the two samples from the upper and the lower layers, while bacterial communities shared similarities. Overall, this new record of cold seep microbial diversity at Site GMGS2-08 showed the complexity of the interaction between biogeochemical reactions and environmental conditions.
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Affiliation(s)
- Hongpeng Cui
- School of Ocean Sciences, China University of Geosciences, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China
| | - Xin Su
- School of Ocean Sciences, China University of Geosciences, Beijing, 100083, China; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China.
| | - Fang Chen
- Guangzhou Marine Geological Survey, Guangzhou, 510075, China
| | | | - Shengxiong Yang
- Guangzhou Marine Geological Survey, Guangzhou, 510075, China
| | - Jinqiang Liang
- Guangzhou Marine Geological Survey, Guangzhou, 510075, China.
| | - Pibo Su
- Guangzhou Marine Geological Survey, Guangzhou, 510075, China
| | - Hailiang Dong
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China; Department of Geology and Environmental Earth Science, Miami University, OH, 45056, USA
| | - Weiguo Hou
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing, 100083, China
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20
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Zoss R, Medina Ferrer F, Flood BE, Jones DS, Louw DC, Bailey J. Microbial communities associated with phosphogenic sediments and phosphoclast-associated DNA of the Benguela upwelling system. GEOBIOLOGY 2019; 17:76-90. [PMID: 30369004 DOI: 10.1111/gbi.12318] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 07/20/2018] [Accepted: 08/21/2018] [Indexed: 06/08/2023]
Abstract
The processes that lead to the precipitation of authigenic calcium phosphate minerals in certain marine pore waters remain poorly understood. Phosphogenesis occurs in sediments beneath some oceanic upwelling zones that harbor polyphosphate-accumulating bacteria. These bacteria are believed to concentrate phosphate in sediment pore waters, creating supersaturated conditions with respect to apatite precursors. However, the relationship between microbes and phosphorite formation is not fully resolved. To further study this association, we examined microbial community data generated from two sources: sediment cores recovered from the shelf of the Benguela upwelling region where phosphorites are currently forming, and DNA preserved within phosphoclasts recovered from a phosphorite deposit along the Benguela shelf. iTag and clone library sequencing of the 16S rRNA gene showed that many of our sediment-hosted communities shared large numbers of phylotypes with one another, and that the same metabolic guilds were represented at localities across the shelf. Sulfate-reducing bacteria and sulfur-oxidizing bacteria were particularly abundant in our datasets, as were phylotypes that are known to carry out nitrification and the anaerobic oxidation of ammonium. The DNA extracted from phosphoclasts contained the signature of a distinct microbial community from those observed in the modern sediments. While some aspects of the modern and phosphoclast communities were similar, we observed both an enrichment of certain common microbial classes found in the modern phosphogenic sediments and a relative depletion of others. The phosphoclast-associated DNA could represent a relict signature of one or more microbial assemblages that were present when the apatite or its precursors precipitated. While these taxa may or may not have contributed to the precipitation of the apatite that now hosts their genetic remains, several groups represented in the phosphoclast extract dataset have the genetic potential to metabolize polyphosphate, and perhaps modulate phosphate concentrations in pore waters where carbonate fluorapatite (or its precursors) are known to be precipitating.
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Affiliation(s)
- Roman Zoss
- Department of Earth Sciences, University of Minnesota, Minnesota, Minneapolis
| | | | - Beverly E Flood
- Department of Earth Sciences, University of Minnesota, Minnesota, Minneapolis
| | - Daniel S Jones
- Department of Earth Sciences, University of Minnesota, Minnesota, Minneapolis
- BioTechnology Institute, University of Minnesota, St. Paul, Minneapolis
| | - Deon C Louw
- Ministry of Fisheries and Marine Resources, National Marine Information and Research Centre, Swakopmund, Namibia
| | - Jake Bailey
- Department of Earth Sciences, University of Minnesota, Minnesota, Minneapolis
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21
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Yu H, Susanti D, McGlynn SE, Skennerton CT, Chourey K, Iyer R, Scheller S, Tavormina PL, Hettich RL, Mukhopadhyay B, Orphan VJ. Comparative Genomics and Proteomic Analysis of Assimilatory Sulfate Reduction Pathways in Anaerobic Methanotrophic Archaea. Front Microbiol 2018; 9:2917. [PMID: 30559729 PMCID: PMC6286981 DOI: 10.3389/fmicb.2018.02917] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Accepted: 11/13/2018] [Indexed: 01/17/2023] Open
Abstract
Sulfate is the predominant electron acceptor for anaerobic oxidation of methane (AOM) in marine sediments. This process is carried out by a syntrophic consortium of anaerobic methanotrophic archaea (ANME) and sulfate reducing bacteria (SRB) through an energy conservation mechanism that is still poorly understood. It was previously hypothesized that ANME alone could couple methane oxidation to dissimilatory sulfate reduction, but a genetic and biochemical basis for this proposal has not been identified. Using comparative genomic and phylogenetic analyses, we found the genetic capacity in ANME and related methanogenic archaea for sulfate reduction, including sulfate adenylyltransferase, APS kinase, APS/PAPS reductase and two different sulfite reductases. Based on characterized homologs and the lack of associated energy conserving complexes, the sulfate reduction pathways in ANME are likely used for assimilation but not dissimilation of sulfate. Environmental metaproteomic analysis confirmed the expression of 6 proteins in the sulfate assimilation pathway of ANME. The highest expressed proteins related to sulfate assimilation were two sulfite reductases, namely assimilatory-type low-molecular-weight sulfite reductase (alSir) and a divergent group of coenzyme F420-dependent sulfite reductase (Group II Fsr). In methane seep sediment microcosm experiments, however, sulfite and zero-valent sulfur amendments were inhibitory to ANME-2a/2c while growth in their syntrophic SRB partner was not observed. Combined with our genomic and metaproteomic results, the passage of sulfur species by ANME as metabolic intermediates for their SRB partners is unlikely. Instead, our findings point to a possible niche for ANME to assimilate inorganic sulfur compounds more oxidized than sulfide in anoxic marine environments.
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Affiliation(s)
- Hang Yu
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States.,Ronald and Maxine Linde Center for Global Environmental Science, California Institute of Technology, Pasadena, CA, United States
| | - Dwi Susanti
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, United States
| | - Shawn E McGlynn
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Connor T Skennerton
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Karuna Chourey
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Ramsunder Iyer
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Silvan Scheller
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Patricia L Tavormina
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Biswarup Mukhopadhyay
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, United States.,Biocomplexity Institute, Virginia Tech, Blacksburg, VA, United States.,Virginia Tech Carilion School of Medicine, Virginia Tech, Blacksburg, VA, United States
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
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22
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Michel AJ, Ward LM, Goffredi SK, Dawson KS, Baldassarre DT, Brenner A, Gotanda KM, McCormack JE, Mullin SW, O'Neill A, Tender GS, Uy JAC, Yu K, Orphan VJ, Chaves JA. The gut of the finch: uniqueness of the gut microbiome of the Galápagos vampire finch. MICROBIOME 2018; 6:167. [PMID: 30231937 PMCID: PMC6146768 DOI: 10.1186/s40168-018-0555-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 09/05/2018] [Indexed: 05/13/2023]
Abstract
BACKGROUND Darwin's finches are a clade of 19 species of passerine birds native to the Galápagos Islands, whose biogeography, specialized beak morphologies, and dietary choices-ranging from seeds to blood-make them a classic example of adaptive radiation. While these iconic birds have been intensely studied, the composition of their gut microbiome and the factors influencing it, including host species, diet, and biogeography, has not yet been explored. RESULTS We characterized the microbial community associated with 12 species of Darwin's finches using high-throughput 16S rRNA sequencing of fecal samples from 114 individuals across nine islands, including the unusual blood-feeding vampire finch (Geospiza septentrionalis) from Darwin and Wolf Islands. The phylum-level core gut microbiome for Darwin's finches included the Firmicutes, Gammaproteobacteria, and Actinobacteria, with members of the Bacteroidetes at conspicuously low abundance. The gut microbiome was surprisingly well conserved across the diversity of finch species, with one exception-the vampire finch-which harbored bacteria that were either absent or extremely rare in other finches, including Fusobacterium, Cetobacterium, Ureaplasma, Mucispirillum, Campylobacter, and various members of the Clostridia-bacteria known from the guts of carnivorous birds and reptiles. Complementary stable isotope analysis of feathers revealed exceptionally high δ15N isotope values in the vampire finch, resembling top marine predators. The Galápagos archipelago is also known for extreme wet and dry seasons, and we observed a significant seasonal shift in the gut microbial community of five additional finch species sampled during both seasons. CONCLUSIONS This study demonstrates the overall conservatism of the finch gut microbiome over short (< 1 Ma) divergence timescales, except in the most extreme case of dietary specialization, and elevates the evolutionary importance of seasonal shifts in driving not only species adaptation, but also gut microbiome composition.
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Affiliation(s)
- Alice J Michel
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Lewis M Ward
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Shana K Goffredi
- Department of Biology, Occidental College, Los Angeles, CA, 90041, USA
| | - Katherine S Dawson
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
- School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ, 08901, USA
| | - Daniel T Baldassarre
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, 08544, USA
| | - Alec Brenner
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Kiyoko M Gotanda
- Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, England
| | - John E McCormack
- Department of Biology, Occidental College, Los Angeles, CA, 90041, USA
| | - Sean W Mullin
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Ariel O'Neill
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Gabrielle S Tender
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - J Albert C Uy
- Department of Biology, University of Miami, Coral Gables, FL, 33146, USA
| | - Kristie Yu
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.
| | - Jaime A Chaves
- Colegio de Ciencias Biológicas y Ambientales, Universidad San Francisco de Quito, Diego de Robles y Pampite, Quito, Ecuador.
- Galápagos Science Center, Puerto Baquerizo Moreno, Galápagos, Ecuador.
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23
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Angermeyer A, Crosby SC, Huber JA. Salt marsh sediment bacterial communities maintain original population structure after transplantation across a latitudinal gradient. PeerJ 2018; 6:e4735. [PMID: 29736349 PMCID: PMC5935077 DOI: 10.7717/peerj.4735] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/19/2018] [Indexed: 12/25/2022] Open
Abstract
Dispersal and environmental selection are two of the most important factors that govern the distributions of microbial communities in nature. While dispersal rates are often inferred by measuring the degree to which community similarity diminishes with increasing geographic distance, determining the extent to which environmental selection impacts the distribution of microbes is more complex. To address this knowledge gap, we performed a large reciprocal transplant experiment to simulate the dispersal of US East Coast salt marsh Spartina alterniflora rhizome-associated microbial sediment communities across a latitudinal gradient and determined if any shifts in microbial community composition occurred as a result of the transplantation. Using bacterial 16S rRNA gene sequencing, we did not observe large-scale changes in community composition over a five-month S. alterniflora summer growing season and found that transplanted communities more closely resembled their origin sites than their destination sites. Furthermore, transplanted communities grouped predominantly by region, with two sites from the north and three sites to the south hosting distinct bacterial taxa, suggesting that sediment communities transplanted from north to south tended to retain their northern microbial distributions, and south to north maintained a southern distribution. A small number of potential indicator 16S rRNA gene sequences had distributions that were strongly correlated to both temperature and nitrogen, indicating that some organisms are more sensitive to environmental factors than others. These results provide new insight into the microbial biogeography of salt marsh sediments and suggest that established bacterial communities in frequently-inundated environments may be both highly resistant to invasion and resilient to some environmental shifts. However, the extent to which environmental selection impacts these communities is taxon specific and variable, highlighting the complex interplay between dispersal and environmental selection for microbial communities in nature.
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Affiliation(s)
- Angus Angermeyer
- Ecology and Evolutionary Biology, Brown University, Providence, RI, USA.,Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Sarah C Crosby
- Ecology and Evolutionary Biology, Brown University, Providence, RI, USA.,Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Harbor Watch, Earthplace Inc., Westport, CT, USA
| | - Julie A Huber
- Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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24
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Marlow JJ, Kumar A, Enalls BC, Reynard LM, Tuross N, Stephanopoulos G, Girguis P. Harnessing a methane-fueled, sediment-free mixed microbial community for utilization of distributed sources of natural gas. Biotechnol Bioeng 2018; 115:1450-1464. [PMID: 29460958 PMCID: PMC5947824 DOI: 10.1002/bit.26576] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/29/2018] [Accepted: 02/08/2018] [Indexed: 01/26/2023]
Abstract
Harnessing the metabolic potential of uncultured microbial communities is a compelling opportunity for the biotechnology industry, an approach that would vastly expand the portfolio of usable feedstocks. Methane is particularly promising because it is abundant and energy‐rich, yet the most efficient methane‐activating metabolic pathways involve mixed communities of anaerobic methanotrophic archaea and sulfate reducing bacteria. These communities oxidize methane at high catabolic efficiency and produce chemically reduced by‐products at a comparable rate and in near‐stoichiometric proportion to methane consumption. These reduced compounds can be used for feedstock and downstream chemical production, and at the production rates observed in situ they are an appealing, cost‐effective prospect. Notably, the microbial constituents responsible for this bioconversion are most prominent in select deep‐sea sediments, and while they can be kept active at surface pressures, they have not yet been cultured in the lab. In an industrial capacity, deep‐sea sediments could be periodically recovered and replenished, but the associated technical challenges and substantial costs make this an untenable approach for full‐scale operations. In this study, we present a novel method for incorporating methanotrophic communities into bioindustrial processes through abstraction onto low mass, easily transportable carbon cloth artificial substrates. Using Gulf of Mexico methane seep sediment as inoculum, optimal physicochemical parameters were established for methane‐oxidizing, sulfide‐generating mesocosm incubations. Metabolic activity required >∼40% seawater salinity, peaking at 100% salinity and 35 °C. Microbial communities were successfully transferred to a carbon cloth substrate, and rates of methane‐dependent sulfide production increased more than threefold per unit volume. Phylogenetic analyses indicated that carbon cloth‐based communities were substantially streamlined and were dominated by Desulfotomaculum geothermicum. Fluorescence in situ hybridization microscopy with carbon cloth fibers revealed a novel spatial arrangement of anaerobic methanotrophs and sulfate reducing bacteria suggestive of an electronic coupling enabled by the artificial substrate. This system: 1) enables a more targeted manipulation of methane‐activating microbial communities using a low‐mass and sediment‐free substrate; 2) holds promise for the simultaneous consumption of a strong greenhouse gas and the generation of usable downstream products; and 3) furthers the broader adoption of uncultured, mixed microbial communities for biotechnological use.
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Affiliation(s)
- Jeffrey J Marlow
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Amit Kumar
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts.,Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Brandon C Enalls
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Linda M Reynard
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Noreen Tuross
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Gregory Stephanopoulos
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Peter Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts
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25
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Case DH, Ijiri A, Morono Y, Tavormina P, Orphan VJ, Inagaki F. Aerobic and Anaerobic Methanotrophic Communities Associated with Methane Hydrates Exposed on the Seafloor: A High-Pressure Sampling and Stable Isotope-Incubation Experiment. Front Microbiol 2017; 8:2569. [PMID: 29312247 PMCID: PMC5742206 DOI: 10.3389/fmicb.2017.02569] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 12/11/2017] [Indexed: 01/26/2023] Open
Abstract
High-pressure (HP) environments represent the largest volumetric majority of habitable space for microorganisms on the planet, including the deep-sea and subsurface biosphere. However, the importance of pressure as an environmental variable affecting deep microbial life and their biogeochemical functions in carbon cycling still remains poorly understood. Here, we designed a new high-volume HP-sediment core sampler that is deployable on the payload of a remotely operated vehicle and can maintain in situ HP conditions throughout multi-month enrichment incubations including daily amendments with liquid media and gases and daily effluent sampling for geochemical or microbiological analysis. Using the HP core device, we incubated sediment and overlying water associated with methane hydrate-exposed on the seafloor of the Joetsu Knoll, Japan, at 10 MPa and 4°C for 45 days in the laboratory. Diversity analyses based on 16S rRNA and methane-related functional genes, as well as carbon isotopic analysis of methane and bicarbonate, indicated the stimulation of both aerobic and anaerobic methanotrophy driven by members of the Methylococcales, and ANME, respectively: i.e., aerobic methanotrophy was observed upon addition of oxygen whereas anaerobic processes subsequently occurred after oxygen consumption. These laboratory-measured rates at 10 MPa were generally in agreement with previously reported rates of methane oxidation in other oceanographic locations.
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Affiliation(s)
- David H Case
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Akira Ijiri
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, Nankoku, Japan.,Geobiotechnology Group, Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Yuki Morono
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, Nankoku, Japan.,Geobiotechnology Group, Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Patricia Tavormina
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Fumio Inagaki
- Geomicrobiology Group, Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology, Nankoku, Japan.,Geobiotechnology Group, Research and Development Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan.,Research and Development Center for Ocean Drilling Science, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
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26
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Dawson KS, Scheller S, Dillon JG, Orphan VJ. Stable Isotope Phenotyping via Cluster Analysis of NanoSIMS Data As a Method for Characterizing Distinct Microbial Ecophysiologies and Sulfur-Cycling in the Environment. Front Microbiol 2016; 7:774. [PMID: 27303371 PMCID: PMC4881376 DOI: 10.3389/fmicb.2016.00774] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/09/2016] [Indexed: 11/24/2022] Open
Abstract
Stable isotope probing (SIP) is a valuable tool for gaining insights into ecophysiology and biogeochemical cycling of environmental microbial communities by tracking isotopically labeled compounds into cellular macromolecules as well as into byproducts of respiration. SIP, in conjunction with nanoscale secondary ion mass spectrometry (NanoSIMS), allows for the visualization of isotope incorporation at the single cell level. In this manner, both active cells within a diverse population as well as heterogeneity in metabolism within a homogeneous population can be observed. The ecophysiological implications of these single cell stable isotope measurements are often limited to the taxonomic resolution of paired fluorescence in situ hybridization (FISH) microscopy. Here we introduce a taxonomy-independent method using multi-isotope SIP and NanoSIMS for identifying and grouping phenotypically similar microbial cells by their chemical and isotopic fingerprint. This method was applied to SIP experiments in a sulfur-cycling biofilm collected from sulfidic intertidal vents amended with 13C-acetate, 15N-ammonium, and 33S-sulfate. Using a cluster analysis technique based on fuzzy c-means to group cells according to their isotope (13C/12C, 15N/14N, and 33S/32S) and elemental ratio (C/CN and S/CN) profiles, our analysis partitioned ~2200 cellular regions of interest (ROIs) into five distinct groups. These isotope phenotype groupings are reflective of the variation in labeled substrate uptake by cells in a multispecies metabolic network dominated by Gamma- and Deltaproteobacteria. Populations independently grouped by isotope phenotype were subsequently compared with paired FISH data, demonstrating a single coherent deltaproteobacterial cluster and multiple gammaproteobacterial groups, highlighting the distinct ecophysiologies of spatially-associated microbes within the sulfur-cycling biofilm from White Point Beach, CA.
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Affiliation(s)
- Katherine S Dawson
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
| | - Silvan Scheller
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
| | - Jesse G Dillon
- Department of Biological Sciences, California State University Long Beach Long Beach, CA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
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27
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Marlow JJ, Skennerton CT, Li Z, Chourey K, Hettich RL, Pan C, Orphan VJ. Proteomic Stable Isotope Probing Reveals Biosynthesis Dynamics of Slow Growing Methane Based Microbial Communities. Front Microbiol 2016; 7:563. [PMID: 27199908 PMCID: PMC4850331 DOI: 10.3389/fmicb.2016.00563] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 04/04/2016] [Indexed: 01/02/2023] Open
Abstract
Marine methane seep habitats represent an important control on the global flux of methane. Nucleotide-based meta-omics studies outline community-wide metabolic potential, but expression patterns of environmentally relevant proteins are poorly characterized. Proteomic stable isotope probing (proteomic SIP) provides additional information by characterizing phylogenetically specific, functionally relevant activity in mixed microbial communities, offering enhanced detection through system-wide product integration. Here we applied proteomic SIP to 15NH4+ and CH4 amended seep sediment microcosms in an attempt to track protein synthesis of slow-growing, low-energy microbial systems. Across all samples, 3495 unique proteins were identified, 11% of which were 15N-labeled. Consistent with the dominant anaerobic oxidation of methane (AOM) activity commonly observed in anoxic seep sediments, proteins associated with sulfate reduction and reverse methanogenesis—including the ANME-2 associated methylenetetrahydromethanopterin reductase (Mer)—were all observed to be actively synthesized (15N-enriched). Conversely, proteins affiliated with putative aerobic sulfur-oxidizing epsilon- and gammaproteobacteria showed a marked decrease over time in our anoxic sediment incubations. The abundance and phylogenetic range of 15N-enriched methyl-coenzyme M reductase (Mcr) orthologs, many of which exhibited novel post-translational modifications, suggests that seep sediments provide niches for multiple organisms performing analogous metabolisms. In addition, 26 proteins of unknown function were consistently detected and actively expressed under conditions supporting AOM, suggesting that they play important roles in methane seep ecosystems. Stable isotope probing in environmental proteomics experiments provides a mechanism to determine protein durability and evaluate lineage-specific responses in complex microbial communities placed under environmentally relevant conditions. Our work here demonstrates the active synthesis of a metabolically specific minority of enzymes, revealing the surprising longevity of most proteins over the course of an extended incubation experiment in an established, slow-growing, methane-impacted environmental system.
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Affiliation(s)
- Jeffrey J Marlow
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
| | - Connor T Skennerton
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
| | - Zhou Li
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Karuna Chourey
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Chongle Pan
- Chemical Sciences Division, Oak Ridge National Laboratory Oak Ridge, TN, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology Pasadena, CA, USA
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28
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Ruff SE, Kuhfuss H, Wegener G, Lott C, Ramette A, Wiedling J, Knittel K, Weber M. Methane Seep in Shallow-Water Permeable Sediment Harbors High Diversity of Anaerobic Methanotrophic Communities, Elba, Italy. Front Microbiol 2016; 7:374. [PMID: 27065954 PMCID: PMC4814501 DOI: 10.3389/fmicb.2016.00374] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/08/2016] [Indexed: 11/13/2022] Open
Abstract
The anaerobic oxidation of methane (AOM) is a key biogeochemical process regulating methane emission from marine sediments into the hydrosphere. AOM is largely mediated by consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB), and has mainly been investigated in deep-sea sediments. Here we studied methane seepage at four spots located at 12 m water depth in coastal, organic carbon depleted permeable sands off the Island of Elba (Italy). We combined biogeochemical measurements, sequencing-based community analyses and in situ hybridization to investigate the microbial communities of this environment. Increased alkalinity, formation of free sulfide and nearly stoichiometric methane oxidation and sulfate reduction rates up to 200 nmol g-1 day-1 indicated the predominance of sulfate-coupled AOM. With up to 40 cm thickness the zones of AOM activity were unusually large and occurred in deeper sediment horizons (20–50 cm below seafloor) as compared to diffusion-dominated deep-sea seeps, which is likely caused by advective flow of pore water due to the shallow water depth and permeability of the sands. Hydrodynamic forces also may be responsible for the substantial phylogenetic and unprecedented morphological diversity of AOM consortia inhabiting these sands, including the clades ANME-1a/b, ANME-2a/b/c, ANME-3, and their partner bacteria SEEP-SRB1a and SEEP-SRB2. High microbial dispersal, the availability of diverse energy sources and high habitat heterogeneity might explain that the emission spots shared few microbial taxa, despite their physical proximity. Although the biogeochemistry of this shallow methane seep was very different to that of deep-sea seeps, their key functional taxa were very closely related, which supports the global dispersal of key taxa and underlines strong selection by methane as the predominant energy source. Mesophilic, methane-fueled ecosystems in shallow-water permeable sediments may comprise distinct microbial habitats due to their unique biogeochemical and physical characteristics. To link AOM phylotypes with seep habitats and to enable future meta-analyses we thus propose that seep environment ontology needs to be further specified.
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Affiliation(s)
- S Emil Ruff
- Department for Molecular Ecology, Max Planck Institute for Marine MicrobiologyBremen, Germany; HGF MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine MicrobiologyBremen, Germany
| | - Hanna Kuhfuss
- Department for Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Gunter Wegener
- HGF MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine MicrobiologyBremen, Germany; MARUM Center for Marine Environmental Sciences, University of BremenBremen, Germany
| | - Christian Lott
- HYDRA Institute for Marine Sciences, Elba Field Station Campo nell'Elba, Italy
| | - Alban Ramette
- HGF MPG Group for Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Johanna Wiedling
- HYDRA Institute for Marine Sciences, Elba Field StationCampo nell'Elba, Italy; Department of Biogeochemistry, Max Planck Institute for Marine MicrobiologyBremen, Germany
| | - Katrin Knittel
- Department for Molecular Ecology, Max Planck Institute for Marine Microbiology Bremen, Germany
| | - Miriam Weber
- HYDRA Institute for Marine Sciences, Elba Field StationCampo nell'Elba, Italy; Department of Biogeochemistry, Max Planck Institute for Marine MicrobiologyBremen, Germany
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29
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Pasulka AL, Levin LA, Steele JA, Case DH, Landry MR, Orphan VJ. Microbial eukaryotic distributions and diversity patterns in a deep-sea methane seep ecosystem. Environ Microbiol 2016; 18:3022-43. [PMID: 26663587 DOI: 10.1111/1462-2920.13185] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/03/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
Although chemosynthetic ecosystems are known to support diverse assemblages of microorganisms, the ecological and environmental factors that structure microbial eukaryotes (heterotrophic protists and fungi) are poorly characterized. In this study, we examined the geographic, geochemical and ecological factors that influence microbial eukaryotic composition and distribution patterns within Hydrate Ridge, a methane seep ecosystem off the coast of Oregon using a combination of high-throughput 18S rRNA tag sequencing, terminal restriction fragment length polymorphism fingerprinting, and cloning and sequencing of full-length 18S rRNA genes. Microbial eukaryotic composition and diversity varied as a function of substrate (carbonate versus sediment), activity (low activity versus active seep sites), sulfide concentration, and region (North versus South Hydrate Ridge). Sulfide concentration was correlated with changes in microbial eukaryotic composition and richness. This work also revealed the influence of oxygen content in the overlying water column and water depth on microbial eukaryotic composition and diversity, and identified distinct patterns from those previously observed for bacteria, archaea and macrofauna in methane seep ecosystems. Characterizing the structure of microbial eukaryotic communities in response to environmental variability is a key step towards understanding if and how microbial eukaryotes influence seep ecosystem structure and function.
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Affiliation(s)
- Alexis L Pasulka
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA. .,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Lisa A Levin
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Josh A Steele
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.,Southern California Coastal Water Research Project, Costa Mesa, CA, USA
| | - David H Case
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Michael R Landry
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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