Widespread microbial mercury methylation genes in the global ocean
Methylmercury is a neurotoxin that bioaccumulates from seawater to high concentrations in marine fish, putting human and ecosystem health at risk. High methylmercury levels have been found in the oxic subsurface waters of all oceans, but only anaerobic microorganisms have been shown to efficiently p...
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ftird:oai:ird.fr:fdi:010077976 2023-05-15T13:47:50+02:00 Widespread microbial mercury methylation genes in the global ocean Villar, E. Cabrol, Léa Heimburger-Boavida, L. E. MONDE 2020 http://www.documentation.ird.fr/hor/fdi:010077976 EN eng http://www.documentation.ird.fr/hor/fdi:010077976 oai:ird.fr:fdi:010077976 Villar E., Cabrol Léa, Heimburger-Boavida L. E. Widespread microbial mercury methylation genes in the global ocean. Environmental Microbiology Reports, 2020, [Early Access], [11 p.] text 2020 ftird 2020-09-22T22:51:58Z Methylmercury is a neurotoxin that bioaccumulates from seawater to high concentrations in marine fish, putting human and ecosystem health at risk. High methylmercury levels have been found in the oxic subsurface waters of all oceans, but only anaerobic microorganisms have been shown to efficiently produce methylmercury in anoxic environments. The microaerophilic nitrite-oxidizing bacteria Nitrospina have previously been suggested as possible mercury methylating bacteria in Antarctic sea ice. However, the microorganisms responsible for processing inorganic mercury into methylmercury in oxic seawater remain unknown. Here, we show metagenomic and metatranscriptomic evidence that the genetic potential for microbial methylmercury production is widespread in oxic seawater. We find high abundance and expression of the key mercury methylating genes hgcAB across all ocean basins, corresponding to the taxonomic relatives of known mercury methylating bacteria from Deltaproteobacteria, Firmicutes and Chloroflexi. Our results identify Nitrospina as the predominant and widespread microorganism carrying and actively expressing hgcAB. The highest hgcAB abundance and expression occurs in the oxic subsurface waters of the global ocean where the highest MeHg concentrations are typically observed. Text Antarc* Antarctic Sea ice IRD (Institute de recherche pour le développement): Horizon Antarctic |
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IRD (Institute de recherche pour le développement): Horizon |
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English |
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Methylmercury is a neurotoxin that bioaccumulates from seawater to high concentrations in marine fish, putting human and ecosystem health at risk. High methylmercury levels have been found in the oxic subsurface waters of all oceans, but only anaerobic microorganisms have been shown to efficiently produce methylmercury in anoxic environments. The microaerophilic nitrite-oxidizing bacteria Nitrospina have previously been suggested as possible mercury methylating bacteria in Antarctic sea ice. However, the microorganisms responsible for processing inorganic mercury into methylmercury in oxic seawater remain unknown. Here, we show metagenomic and metatranscriptomic evidence that the genetic potential for microbial methylmercury production is widespread in oxic seawater. We find high abundance and expression of the key mercury methylating genes hgcAB across all ocean basins, corresponding to the taxonomic relatives of known mercury methylating bacteria from Deltaproteobacteria, Firmicutes and Chloroflexi. Our results identify Nitrospina as the predominant and widespread microorganism carrying and actively expressing hgcAB. The highest hgcAB abundance and expression occurs in the oxic subsurface waters of the global ocean where the highest MeHg concentrations are typically observed. |
format |
Text |
author |
Villar, E. Cabrol, Léa Heimburger-Boavida, L. E. |
spellingShingle |
Villar, E. Cabrol, Léa Heimburger-Boavida, L. E. Widespread microbial mercury methylation genes in the global ocean |
author_facet |
Villar, E. Cabrol, Léa Heimburger-Boavida, L. E. |
author_sort |
Villar, E. |
title |
Widespread microbial mercury methylation genes in the global ocean |
title_short |
Widespread microbial mercury methylation genes in the global ocean |
title_full |
Widespread microbial mercury methylation genes in the global ocean |
title_fullStr |
Widespread microbial mercury methylation genes in the global ocean |
title_full_unstemmed |
Widespread microbial mercury methylation genes in the global ocean |
title_sort |
widespread microbial mercury methylation genes in the global ocean |
publishDate |
2020 |
url |
http://www.documentation.ird.fr/hor/fdi:010077976 |
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MONDE |
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Antarctic |
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Antarctic |
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Antarc* Antarctic Sea ice |
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Antarc* Antarctic Sea ice |
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http://www.documentation.ird.fr/hor/fdi:010077976 oai:ird.fr:fdi:010077976 Villar E., Cabrol Léa, Heimburger-Boavida L. E. Widespread microbial mercury methylation genes in the global ocean. Environmental Microbiology Reports, 2020, [Early Access], [11 p.] |
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