Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil
Arctic tundra soils store a globally significant amount of mercury (Hg), which could be transformed to the neurotoxic methylmercury (MeHg) upon warming and thus poses serious threats to the Arctic ecosystem. However, our knowledge of the biogeochemical drivers of MeHg production is limited in these...
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2022
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ftcdlib:oai:escholarship.org:ark:/13030/qt6cp5h5j8 2024-01-14T10:04:13+01:00 Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil Zhang, Lijie Philben, Michael Taş, Neslihan Johs, Alexander Yang, Ziming Wullschleger, Stan D Graham, David E Pierce, Eric M Gu, Baohua 2022-04-01 application/pdf https://escholarship.org/uc/item/6cp5h5j8 unknown eScholarship, University of California qt6cp5h5j8 https://escholarship.org/uc/item/6cp5h5j8 public Environmental Sciences Pollution and Contamination Life Below Water Mercury Methylmercury Compounds Microbiota Soil Soil Pollutants Wetlands Methylation Acetate Sulfate Microbial community Syntrophy article 2022 ftcdlib 2023-12-18T19:06:41Z Arctic tundra soils store a globally significant amount of mercury (Hg), which could be transformed to the neurotoxic methylmercury (MeHg) upon warming and thus poses serious threats to the Arctic ecosystem. However, our knowledge of the biogeochemical drivers of MeHg production is limited in these soils. Using substrate addition (acetate and sulfate) and selective microbial inhibition approaches, we investigated the geochemical drivers and dominant microbial methylators in 60-day microcosm incubations with two tundra soils: a circumneutral fen soil and an acidic bog soil, collected near Nome, Alaska, United States. Results showed that increasing acetate concentration had negligible influences on MeHg production in both soils. However, inhibition of sulfate-reducing bacteria (SRB) completely stalled MeHg production in the fen soil in the first 15 days, whereas addition of sulfate in the low-sulfate bog soil increased MeHg production by 5-fold, suggesting prominent roles of SRB in Hg(II) methylation. Without the addition of sulfate in the bog soil or when sulfate was depleted in the fen soil (after 15 days), both SRB and methanogens contributed to MeHg production. Analysis of microbial community composition confirmed the presence of several phyla known to harbor microorganisms associated with Hg(II) methylation in the soils. The observations suggest that SRB and methanogens were mainly responsible for Hg(II) methylation in these tundra soils, although their relative contributions depended on the availability of sulfate and possibly syntrophic metabolisms between SRB and methanogens. Article in Journal/Newspaper Arctic Nome Tundra Alaska University of California: eScholarship Arctic |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Environmental Sciences Pollution and Contamination Life Below Water Mercury Methylmercury Compounds Microbiota Soil Soil Pollutants Wetlands Methylation Acetate Sulfate Microbial community Syntrophy |
spellingShingle |
Environmental Sciences Pollution and Contamination Life Below Water Mercury Methylmercury Compounds Microbiota Soil Soil Pollutants Wetlands Methylation Acetate Sulfate Microbial community Syntrophy Zhang, Lijie Philben, Michael Taş, Neslihan Johs, Alexander Yang, Ziming Wullschleger, Stan D Graham, David E Pierce, Eric M Gu, Baohua Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
topic_facet |
Environmental Sciences Pollution and Contamination Life Below Water Mercury Methylmercury Compounds Microbiota Soil Soil Pollutants Wetlands Methylation Acetate Sulfate Microbial community Syntrophy |
description |
Arctic tundra soils store a globally significant amount of mercury (Hg), which could be transformed to the neurotoxic methylmercury (MeHg) upon warming and thus poses serious threats to the Arctic ecosystem. However, our knowledge of the biogeochemical drivers of MeHg production is limited in these soils. Using substrate addition (acetate and sulfate) and selective microbial inhibition approaches, we investigated the geochemical drivers and dominant microbial methylators in 60-day microcosm incubations with two tundra soils: a circumneutral fen soil and an acidic bog soil, collected near Nome, Alaska, United States. Results showed that increasing acetate concentration had negligible influences on MeHg production in both soils. However, inhibition of sulfate-reducing bacteria (SRB) completely stalled MeHg production in the fen soil in the first 15 days, whereas addition of sulfate in the low-sulfate bog soil increased MeHg production by 5-fold, suggesting prominent roles of SRB in Hg(II) methylation. Without the addition of sulfate in the bog soil or when sulfate was depleted in the fen soil (after 15 days), both SRB and methanogens contributed to MeHg production. Analysis of microbial community composition confirmed the presence of several phyla known to harbor microorganisms associated with Hg(II) methylation in the soils. The observations suggest that SRB and methanogens were mainly responsible for Hg(II) methylation in these tundra soils, although their relative contributions depended on the availability of sulfate and possibly syntrophic metabolisms between SRB and methanogens. |
format |
Article in Journal/Newspaper |
author |
Zhang, Lijie Philben, Michael Taş, Neslihan Johs, Alexander Yang, Ziming Wullschleger, Stan D Graham, David E Pierce, Eric M Gu, Baohua |
author_facet |
Zhang, Lijie Philben, Michael Taş, Neslihan Johs, Alexander Yang, Ziming Wullschleger, Stan D Graham, David E Pierce, Eric M Gu, Baohua |
author_sort |
Zhang, Lijie |
title |
Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
title_short |
Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
title_full |
Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
title_fullStr |
Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
title_full_unstemmed |
Unravelling biogeochemical drivers of methylmercury production in an Arctic fen soil and a bog soil |
title_sort |
unravelling biogeochemical drivers of methylmercury production in an arctic fen soil and a bog soil |
publisher |
eScholarship, University of California |
publishDate |
2022 |
url |
https://escholarship.org/uc/item/6cp5h5j8 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Nome Tundra Alaska |
genre_facet |
Arctic Nome Tundra Alaska |
op_relation |
qt6cp5h5j8 https://escholarship.org/uc/item/6cp5h5j8 |
op_rights |
public |
_version_ |
1788058823169146880 |