Dataset Information

Diverse methylotrophic methanogenic archaea cause high methane emissions from seagrass meadows.

ABSTRACT: Marine coastlines colonized by seagrasses are a net source of methane to the atmosphere. However, methane emissions from these environments are still poorly constrained, and the underlying processes and responsible microorganisms remain largely unknown. Here, we investigated methane turnover in seagrass meadows of Posidonia oceanica in the Mediterranean Sea. The underlying sediments exhibited median net fluxes of methane into the water column of ca. 106 µmol CH4 ⋅ m-2 ⋅ d-1 Our data show that this methane production was sustained by methylated compounds produced by the plant, rather than by fermentation of buried organic carbon. Interestingly, methane production was maintained long after the living plant died off, likely due to the persistence of methylated compounds, such as choline, betaines, and dimethylsulfoniopropionate, in detached plant leaves and rhizomes. We recovered multiple mcrA gene sequences, encoding for methyl-coenzyme M reductase (Mcr), the key methanogenic enzyme, from the seagrass sediments. Most retrieved mcrA gene sequences were affiliated with a clade of divergent Mcr and belonged to the uncultured Candidatus Helarchaeota of the Asgard superphylum, suggesting a possible involvement of these divergent Mcr in methane metabolism. Taken together, our findings identify the mechanisms controlling methane emissions from these important blue carbon ecosystems.

SUBMITTER: Schorn S

PROVIDER: S-EPMC8892325 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature

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Diverse methylotrophic methanogenic archaea cause high methane emissions from seagrass meadows.

Schorn Sina S Ahmerkamp Soeren S Bullock Emma E Weber Miriam M Lott Christian C Liebeke Manuel M Lavik Gaute G Kuypers Marcel M M MMM Graf Jon S JS Milucka Jana J

Proceedings of the National Academy of Sciences of the United States of America 20220301 9

Marine coastlines colonized by seagrasses are a net source of methane to the atmosphere. However, methane emissions from these environments are still poorly constrained, and the underlying processes and responsible microorganisms remain largely unknown. Here, we investigated methane turnover in seagrass meadows of Posidonia oceanica in the Mediterranean Sea. The underlying sediments exhibited median net fluxes of methane into the water column of ca. 106 µmol CH4 ⋅ m-2</sup ...[more]

PMID: 35165204

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Dataset Information

Diverse methylotrophic methanogenic archaea cause high methane emissions from seagrass meadows.

Publications

Diverse methylotrophic methanogenic archaea cause high methane emissions from seagrass meadows.

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