Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria
Cyanobacteria are thought to be the main N2-fixing organisms (diazotrophs) in marine pelagic waters, but recent molecular analyses indicate that non-cyanobacterial diazotrophs are also present and active. Existing data are, however, restricted geographically and by limited sequencing depths. Our ana...
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ftpubmed:oai:pubmedcentral.nih.gov:3084785 2023-05-15T15:13:07+02:00 Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria Farnelid, Hanna Andersson, Anders F. Bertilsson, Stefan Al-Soud, Waleed Abu Hansen, Lars H. Sørensen, Søren Steward, Grieg F. Hagström, Åke Riemann, Lasse 2011-04-29 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3084785 http://www.ncbi.nlm.nih.gov/pubmed/21559425 https://doi.org/10.1371/journal.pone.0019223 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3084785 http://www.ncbi.nlm.nih.gov/pubmed/21559425 http://dx.doi.org/10.1371/journal.pone.0019223 Farnelid et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. CC-BY Research Article Text 2011 ftpubmed https://doi.org/10.1371/journal.pone.0019223 2013-09-03T13:58:38Z Cyanobacteria are thought to be the main N2-fixing organisms (diazotrophs) in marine pelagic waters, but recent molecular analyses indicate that non-cyanobacterial diazotrophs are also present and active. Existing data are, however, restricted geographically and by limited sequencing depths. Our analysis of 79,090 nitrogenase (nifH) PCR amplicons encoding 7,468 unique proteins from surface samples (ten DNA samples and two RNA samples) collected at ten marine locations world-wide provides the first in-depth survey of a functional bacterial gene and yield insights into the composition and diversity of the nifH gene pool in marine waters. Great divergence in nifH composition was observed between sites. Cyanobacteria-like genes were most frequent among amplicons from the warmest waters, but overall the data set was dominated by nifH sequences most closely related to non-cyanobacteria. Clusters related to Alpha-, Beta-, Gamma-, and Delta-Proteobacteria were most common and showed distinct geographic distributions. Sequences related to anaerobic bacteria (nifH Cluster III) were generally rare, but preponderant in cold waters, especially in the Arctic. Although the two transcript samples were dominated by unicellular cyanobacteria, 42% of the identified non-cyanobacterial nifH clusters from the corresponding DNA samples were also detected in cDNA. The study indicates that non-cyanobacteria account for a substantial part of the nifH gene pool in marine surface waters and that these genes are at least occasionally expressed. The contribution of non-cyanobacterial diazotrophs to the global N2 fixation budget cannot be inferred from sequence data alone, but the prevalence of non-cyanobacterial nifH genes and transcripts suggest that these bacteria are ecologically significant. Text Arctic PubMed Central (PMC) Arctic PLoS ONE 6 4 e19223 |
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Research Article Farnelid, Hanna Andersson, Anders F. Bertilsson, Stefan Al-Soud, Waleed Abu Hansen, Lars H. Sørensen, Søren Steward, Grieg F. Hagström, Åke Riemann, Lasse Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
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Research Article |
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Cyanobacteria are thought to be the main N2-fixing organisms (diazotrophs) in marine pelagic waters, but recent molecular analyses indicate that non-cyanobacterial diazotrophs are also present and active. Existing data are, however, restricted geographically and by limited sequencing depths. Our analysis of 79,090 nitrogenase (nifH) PCR amplicons encoding 7,468 unique proteins from surface samples (ten DNA samples and two RNA samples) collected at ten marine locations world-wide provides the first in-depth survey of a functional bacterial gene and yield insights into the composition and diversity of the nifH gene pool in marine waters. Great divergence in nifH composition was observed between sites. Cyanobacteria-like genes were most frequent among amplicons from the warmest waters, but overall the data set was dominated by nifH sequences most closely related to non-cyanobacteria. Clusters related to Alpha-, Beta-, Gamma-, and Delta-Proteobacteria were most common and showed distinct geographic distributions. Sequences related to anaerobic bacteria (nifH Cluster III) were generally rare, but preponderant in cold waters, especially in the Arctic. Although the two transcript samples were dominated by unicellular cyanobacteria, 42% of the identified non-cyanobacterial nifH clusters from the corresponding DNA samples were also detected in cDNA. The study indicates that non-cyanobacteria account for a substantial part of the nifH gene pool in marine surface waters and that these genes are at least occasionally expressed. The contribution of non-cyanobacterial diazotrophs to the global N2 fixation budget cannot be inferred from sequence data alone, but the prevalence of non-cyanobacterial nifH genes and transcripts suggest that these bacteria are ecologically significant. |
format |
Text |
author |
Farnelid, Hanna Andersson, Anders F. Bertilsson, Stefan Al-Soud, Waleed Abu Hansen, Lars H. Sørensen, Søren Steward, Grieg F. Hagström, Åke Riemann, Lasse |
author_facet |
Farnelid, Hanna Andersson, Anders F. Bertilsson, Stefan Al-Soud, Waleed Abu Hansen, Lars H. Sørensen, Søren Steward, Grieg F. Hagström, Åke Riemann, Lasse |
author_sort |
Farnelid, Hanna |
title |
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
title_short |
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
title_full |
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
title_fullStr |
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
title_full_unstemmed |
Nitrogenase Gene Amplicons from Global Marine Surface Waters Are Dominated by Genes of Non-Cyanobacteria |
title_sort |
nitrogenase gene amplicons from global marine surface waters are dominated by genes of non-cyanobacteria |
publisher |
Public Library of Science |
publishDate |
2011 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3084785 http://www.ncbi.nlm.nih.gov/pubmed/21559425 https://doi.org/10.1371/journal.pone.0019223 |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3084785 http://www.ncbi.nlm.nih.gov/pubmed/21559425 http://dx.doi.org/10.1371/journal.pone.0019223 |
op_rights |
Farnelid et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, 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.0019223 |
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e19223 |
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