Methane-oxidizing seawater microbial communities from an Arctic shelf
Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydr...
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ftdoajarticles:oai:doaj.org/article:5f02b65ec4eb4d3795e587d9e4434a2b 2023-05-15T15:00:38+02:00 Methane-oxidizing seawater microbial communities from an Arctic shelf C. Uhlig J. B. Kirkpatrick S. D'Hondt B. Loose 2018-06-01T00:00:00Z https://doi.org/10.5194/bg-15-3311-2018 https://doaj.org/article/5f02b65ec4eb4d3795e587d9e4434a2b EN eng Copernicus Publications https://www.biogeosciences.net/15/3311/2018/bg-15-3311-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-3311-2018 1726-4170 1726-4189 https://doaj.org/article/5f02b65ec4eb4d3795e587d9e4434a2b Biogeosciences, Vol 15, Pp 3311-3329 (2018) Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.5194/bg-15-3311-2018 2022-12-31T02:42:21Z Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydrate. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L −1 , approximately 4.8 times oversaturated relative to atmospheric equilibrium. The group of methane-oxidizing bacteria (MOB) in the natural seawater and incubated seawater was > 97 % dominated by Methylococcales ( γ -Proteobacteria). Incubations of seawater under a range of methane concentrations led to loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5 % at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were 4 times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotroph sequences correlated tightly with the rate constant ( k ox ) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg −1 were found, Methylobacterium ( α -Proteobacteria) was the dominant MOB with a relative abundance of 80 %. Total MOB abundances were very low in sea ice, with maximal fractions found at the ice–snow interface (0.1 %), while non-MOB methylotrophs were present in abundances similar to natural seawater communities. The dissimilarities in MOB taxa, methane concentrations, and stable isotope ratios between the sea ice and water column point toward different methane dynamics in the two environments. Article in Journal/Newspaper Arctic Global warming Ice permafrost Sea ice Alaska Directory of Open Access Journals: DOAJ Articles Arctic Biogeosciences 15 11 3311 3329 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
spellingShingle |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 C. Uhlig J. B. Kirkpatrick S. D'Hondt B. Loose Methane-oxidizing seawater microbial communities from an Arctic shelf |
topic_facet |
Ecology QH540-549.5 Life QH501-531 Geology QE1-996.5 |
description |
Marine microbial communities can consume dissolved methane before it can escape to the atmosphere and contribute to global warming. Seawater over the shallow Arctic shelf is characterized by excess methane compared to atmospheric equilibrium. This methane originates in sediment, permafrost, and hydrate. Particularly high concentrations are found beneath sea ice. We studied the structure and methane oxidation potential of the microbial communities from seawater collected close to Utqiagvik, Alaska, in April 2016. The in situ methane concentrations were 16.3 ± 7.2 nmol L −1 , approximately 4.8 times oversaturated relative to atmospheric equilibrium. The group of methane-oxidizing bacteria (MOB) in the natural seawater and incubated seawater was > 97 % dominated by Methylococcales ( γ -Proteobacteria). Incubations of seawater under a range of methane concentrations led to loss of diversity in the bacterial community. The abundance of MOB was low with maximal fractions of 2.5 % at 200 times elevated methane concentration, while sequence reads of non-MOB methylotrophs were 4 times more abundant than MOB in most incubations. The abundances of MOB as well as non-MOB methylotroph sequences correlated tightly with the rate constant ( k ox ) for methane oxidation, indicating that non-MOB methylotrophs might be coupled to MOB and involved in community methane oxidation. In sea ice, where methane concentrations of 82 ± 35.8 nmol kg −1 were found, Methylobacterium ( α -Proteobacteria) was the dominant MOB with a relative abundance of 80 %. Total MOB abundances were very low in sea ice, with maximal fractions found at the ice–snow interface (0.1 %), while non-MOB methylotrophs were present in abundances similar to natural seawater communities. The dissimilarities in MOB taxa, methane concentrations, and stable isotope ratios between the sea ice and water column point toward different methane dynamics in the two environments. |
format |
Article in Journal/Newspaper |
author |
C. Uhlig J. B. Kirkpatrick S. D'Hondt B. Loose |
author_facet |
C. Uhlig J. B. Kirkpatrick S. D'Hondt B. Loose |
author_sort |
C. Uhlig |
title |
Methane-oxidizing seawater microbial communities from an Arctic shelf |
title_short |
Methane-oxidizing seawater microbial communities from an Arctic shelf |
title_full |
Methane-oxidizing seawater microbial communities from an Arctic shelf |
title_fullStr |
Methane-oxidizing seawater microbial communities from an Arctic shelf |
title_full_unstemmed |
Methane-oxidizing seawater microbial communities from an Arctic shelf |
title_sort |
methane-oxidizing seawater microbial communities from an arctic shelf |
publisher |
Copernicus Publications |
publishDate |
2018 |
url |
https://doi.org/10.5194/bg-15-3311-2018 https://doaj.org/article/5f02b65ec4eb4d3795e587d9e4434a2b |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Global warming Ice permafrost Sea ice Alaska |
genre_facet |
Arctic Global warming Ice permafrost Sea ice Alaska |
op_source |
Biogeosciences, Vol 15, Pp 3311-3329 (2018) |
op_relation |
https://www.biogeosciences.net/15/3311/2018/bg-15-3311-2018.pdf https://doaj.org/toc/1726-4170 https://doaj.org/toc/1726-4189 doi:10.5194/bg-15-3311-2018 1726-4170 1726-4189 https://doaj.org/article/5f02b65ec4eb4d3795e587d9e4434a2b |
op_doi |
https://doi.org/10.5194/bg-15-3311-2018 |
container_title |
Biogeosciences |
container_volume |
15 |
container_issue |
11 |
container_start_page |
3311 |
op_container_end_page |
3329 |
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1766332709495373824 |