Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin
In deep ocean hypersaline basins, the combination of high salinity, unusual ionic composition and anoxic conditions represents significant challenges for microbial life. We used geochemical porewater characterization and DNA sequencing based taxonomic surveys to enable environmental and microbial ch...
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ftpubmed:oai:pubmedcentral.nih.gov:7173876 2023-05-15T17:53:14+02:00 Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin Nigro, Lisa M. Elling, Felix J. Hinrichs, Kai-Uwe Joye, Samantha B. Teske, Andreas 2020-04-21 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173876/ http://www.ncbi.nlm.nih.gov/pubmed/32315331 https://doi.org/10.1371/journal.pone.0231676 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173876/ http://www.ncbi.nlm.nih.gov/pubmed/32315331 http://dx.doi.org/10.1371/journal.pone.0231676 © 2020 Nigro et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Research Article Text 2020 ftpubmed https://doi.org/10.1371/journal.pone.0231676 2020-05-03T00:30:51Z In deep ocean hypersaline basins, the combination of high salinity, unusual ionic composition and anoxic conditions represents significant challenges for microbial life. We used geochemical porewater characterization and DNA sequencing based taxonomic surveys to enable environmental and microbial characterization of anoxic hypersaline sediments and brines in the Orca Basin, the largest brine basin in the Gulf of Mexico. Full-length bacterial 16S rRNA gene clone libraries from hypersaline sediments and the overlying brine were dominated by the uncultured halophilic KB1 lineage, Deltaproteobacteria related to cultured sulfate-reducing halophilic genera, and specific lineages of heterotrophic Bacteroidetes. Archaeal clones were dominated by members of the halophilic methanogen genus Methanohalophilus, and the ammonia-oxidizing Marine Group I (MG-I) within the Thaumarchaeota. Illumina sequencing revealed higher phylum- and subphylum-level complexity, especially in lower-salinity sediments from the Orca Basin slope. Illumina and clone library surveys consistently detected MG-I Thaumarchaeota and halotolerant Deltaproteobacteria in the hypersaline anoxic sediments, but relative abundances of the KB1 lineage differed between the two sequencing methods. The stable isotopic composition of dissolved inorganic carbon and methane in porewater, and sulfate concentrations decreasing downcore indicated methanogenesis and sulfate reduction in the anoxic sediments. While anaerobic microbial processes likely occur at low rates near their maximal salinity thresholds in Orca Basin, long-term accumulation of reaction products leads to high methane concentrations and reducing conditions within the Orca Basin brine and sediments. Text Orca PubMed Central (PMC) PLOS ONE 15 4 e0231676 |
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Research Article Nigro, Lisa M. Elling, Felix J. Hinrichs, Kai-Uwe Joye, Samantha B. Teske, Andreas Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
topic_facet |
Research Article |
description |
In deep ocean hypersaline basins, the combination of high salinity, unusual ionic composition and anoxic conditions represents significant challenges for microbial life. We used geochemical porewater characterization and DNA sequencing based taxonomic surveys to enable environmental and microbial characterization of anoxic hypersaline sediments and brines in the Orca Basin, the largest brine basin in the Gulf of Mexico. Full-length bacterial 16S rRNA gene clone libraries from hypersaline sediments and the overlying brine were dominated by the uncultured halophilic KB1 lineage, Deltaproteobacteria related to cultured sulfate-reducing halophilic genera, and specific lineages of heterotrophic Bacteroidetes. Archaeal clones were dominated by members of the halophilic methanogen genus Methanohalophilus, and the ammonia-oxidizing Marine Group I (MG-I) within the Thaumarchaeota. Illumina sequencing revealed higher phylum- and subphylum-level complexity, especially in lower-salinity sediments from the Orca Basin slope. Illumina and clone library surveys consistently detected MG-I Thaumarchaeota and halotolerant Deltaproteobacteria in the hypersaline anoxic sediments, but relative abundances of the KB1 lineage differed between the two sequencing methods. The stable isotopic composition of dissolved inorganic carbon and methane in porewater, and sulfate concentrations decreasing downcore indicated methanogenesis and sulfate reduction in the anoxic sediments. While anaerobic microbial processes likely occur at low rates near their maximal salinity thresholds in Orca Basin, long-term accumulation of reaction products leads to high methane concentrations and reducing conditions within the Orca Basin brine and sediments. |
format |
Text |
author |
Nigro, Lisa M. Elling, Felix J. Hinrichs, Kai-Uwe Joye, Samantha B. Teske, Andreas |
author_facet |
Nigro, Lisa M. Elling, Felix J. Hinrichs, Kai-Uwe Joye, Samantha B. Teske, Andreas |
author_sort |
Nigro, Lisa M. |
title |
Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
title_short |
Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
title_full |
Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
title_fullStr |
Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
title_full_unstemmed |
Microbial ecology and biogeochemistry of hypersaline sediments in Orca Basin |
title_sort |
microbial ecology and biogeochemistry of hypersaline sediments in orca basin |
publisher |
Public Library of Science |
publishDate |
2020 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173876/ http://www.ncbi.nlm.nih.gov/pubmed/32315331 https://doi.org/10.1371/journal.pone.0231676 |
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Orca |
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Orca |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7173876/ http://www.ncbi.nlm.nih.gov/pubmed/32315331 http://dx.doi.org/10.1371/journal.pone.0231676 |
op_rights |
© 2020 Nigro et al http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
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CC-BY |
op_doi |
https://doi.org/10.1371/journal.pone.0231676 |
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PLOS ONE |
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15 |
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4 |
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e0231676 |
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