Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing
Lakes are currently responsible for a significant amount of total natural methane emission. Microbial oxidation of methane plays a central role in Arctic carbon cycling, potentially reducing methane emissions from lakes, though little is known about methane cycling in the water column of Arctic lake...
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2022
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Online Access: | https://doi.org/10.3389/fenvs.2022.884133 https://doaj.org/article/aa39b8f1365b4646b55ad164dc8b78bf |
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fttriple:oai:gotriple.eu:oai:doaj.org/article:aa39b8f1365b4646b55ad164dc8b78bf 2023-05-15T14:31:47+02:00 Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing Sarah B. Cadieux Ursel M. E. Schütte Chris Hemmerich Sarah Powers Jeffrey R. White 2022-10-01 https://doi.org/10.3389/fenvs.2022.884133 https://doaj.org/article/aa39b8f1365b4646b55ad164dc8b78bf en eng Frontiers Media S.A. 2296-665X doi:10.3389/fenvs.2022.884133 https://doaj.org/article/aa39b8f1365b4646b55ad164dc8b78bf undefined Frontiers in Environmental Science, Vol 10 (2022) methane oxidation methanotrophs isotopes lake arctic methane cycling envir geo Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2022 fttriple https://doi.org/10.3389/fenvs.2022.884133 2023-01-22T19:11:33Z Lakes are currently responsible for a significant amount of total natural methane emission. Microbial oxidation of methane plays a central role in Arctic carbon cycling, potentially reducing methane emissions from lakes, though little is known about methane cycling in the water column of Arctic lakes. We previously detected surprisingly large enrichments of heavy carbon and hydrogen isotopes of methane in three small lakes in Greenland suggesting unusually efficient methanotrophic communities in these Arctic lakes. Using stable isotope and 16S rRNA gene sequencing we determined carbon and hydrogen isotopes and microbial community composition down the water column of Teardrop lake, under open-water conditions. We found that isotopic values of methane in Teardrop lake were again highly enriched 13C and 2H at 4 m depth with −13.2‰ and −27.1‰ values for carbon and hydrogen isotopes, respectively. Methane concentrations slightly increased at the depth interval with isotope enrichment, not typical of classic methanotrophy. Consistent with isotopic enrichment of the heavy isotopes we detected the highest relative abundance of putative methanotrophs, in particular Methylovulum at 4 m. The highest relative abundance of putative methanogens was detected at 3 m as well as at 5 m. At the same depth interval, temperature and oxidation reduction potential also increase, supporting increased microbial activity within the water column. Based on geochemical and microbial observations, we suggest that the methane cycling in Teardrop lake is decoupled from a traditional depth dependent model where the dominant source of methane is in the anoxic sediments. Instead, methane in the water column is likely from a combination of anoxic sediment, littoral transport and oxic methanogenesis in the mid-water column, and recycling of carbon within the water column is leading to extreme isotope enrichments. Thus, understanding linkages between depth-dependent microbial dynamics and methane biogeochemistry are necessary to constrain the ... Article in Journal/Newspaper arctic methane Arctic Greenland Kangerlussuaq Unknown Arctic Arctic Lake ENVELOPE(-130.826,-130.826,57.231,57.231) Greenland Kangerlussuaq ENVELOPE(-55.633,-55.633,72.633,72.633) Teardrop ENVELOPE(163.917,163.917,-78.150,-78.150) Teardrop Lake ENVELOPE(-94.983,-94.983,74.683,74.683) Frontiers in Environmental Science 10 |
institution |
Open Polar |
collection |
Unknown |
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fttriple |
language |
English |
topic |
methane oxidation methanotrophs isotopes lake arctic methane cycling envir geo |
spellingShingle |
methane oxidation methanotrophs isotopes lake arctic methane cycling envir geo Sarah B. Cadieux Ursel M. E. Schütte Chris Hemmerich Sarah Powers Jeffrey R. White Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
topic_facet |
methane oxidation methanotrophs isotopes lake arctic methane cycling envir geo |
description |
Lakes are currently responsible for a significant amount of total natural methane emission. Microbial oxidation of methane plays a central role in Arctic carbon cycling, potentially reducing methane emissions from lakes, though little is known about methane cycling in the water column of Arctic lakes. We previously detected surprisingly large enrichments of heavy carbon and hydrogen isotopes of methane in three small lakes in Greenland suggesting unusually efficient methanotrophic communities in these Arctic lakes. Using stable isotope and 16S rRNA gene sequencing we determined carbon and hydrogen isotopes and microbial community composition down the water column of Teardrop lake, under open-water conditions. We found that isotopic values of methane in Teardrop lake were again highly enriched 13C and 2H at 4 m depth with −13.2‰ and −27.1‰ values for carbon and hydrogen isotopes, respectively. Methane concentrations slightly increased at the depth interval with isotope enrichment, not typical of classic methanotrophy. Consistent with isotopic enrichment of the heavy isotopes we detected the highest relative abundance of putative methanotrophs, in particular Methylovulum at 4 m. The highest relative abundance of putative methanogens was detected at 3 m as well as at 5 m. At the same depth interval, temperature and oxidation reduction potential also increase, supporting increased microbial activity within the water column. Based on geochemical and microbial observations, we suggest that the methane cycling in Teardrop lake is decoupled from a traditional depth dependent model where the dominant source of methane is in the anoxic sediments. Instead, methane in the water column is likely from a combination of anoxic sediment, littoral transport and oxic methanogenesis in the mid-water column, and recycling of carbon within the water column is leading to extreme isotope enrichments. Thus, understanding linkages between depth-dependent microbial dynamics and methane biogeochemistry are necessary to constrain the ... |
format |
Article in Journal/Newspaper |
author |
Sarah B. Cadieux Ursel M. E. Schütte Chris Hemmerich Sarah Powers Jeffrey R. White |
author_facet |
Sarah B. Cadieux Ursel M. E. Schütte Chris Hemmerich Sarah Powers Jeffrey R. White |
author_sort |
Sarah B. Cadieux |
title |
Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
title_short |
Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
title_full |
Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
title_fullStr |
Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
title_full_unstemmed |
Exploring methane cycling in an arctic lake in Kangerlussuaq Greenland using stable isotopes and 16S rRNA gene sequencing |
title_sort |
exploring methane cycling in an arctic lake in kangerlussuaq greenland using stable isotopes and 16s rrna gene sequencing |
publisher |
Frontiers Media S.A. |
publishDate |
2022 |
url |
https://doi.org/10.3389/fenvs.2022.884133 https://doaj.org/article/aa39b8f1365b4646b55ad164dc8b78bf |
long_lat |
ENVELOPE(-130.826,-130.826,57.231,57.231) ENVELOPE(-55.633,-55.633,72.633,72.633) ENVELOPE(163.917,163.917,-78.150,-78.150) ENVELOPE(-94.983,-94.983,74.683,74.683) |
geographic |
Arctic Arctic Lake Greenland Kangerlussuaq Teardrop Teardrop Lake |
geographic_facet |
Arctic Arctic Lake Greenland Kangerlussuaq Teardrop Teardrop Lake |
genre |
arctic methane Arctic Greenland Kangerlussuaq |
genre_facet |
arctic methane Arctic Greenland Kangerlussuaq |
op_source |
Frontiers in Environmental Science, Vol 10 (2022) |
op_relation |
2296-665X doi:10.3389/fenvs.2022.884133 https://doaj.org/article/aa39b8f1365b4646b55ad164dc8b78bf |
op_rights |
undefined |
op_doi |
https://doi.org/10.3389/fenvs.2022.884133 |
container_title |
Frontiers in Environmental Science |
container_volume |
10 |
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1766305319949959168 |