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. 1985 Aug;50(2):498–502. doi: 10.1128/aem.50.2.498-502.1985

Sulfate-Reducing Bacteria: Principal Methylators of Mercury in Anoxic Estuarine Sediment †

G C Compeau 1, R Bartha 1,*
PMCID: PMC238649  PMID: 16346866

Abstract

Substrate-electron acceptor combinations and specific metabolic inhibitors were applied to anoxic saltmarsh sediment spiked with mercuric ions (Hg2+) in an effort to identify, by a direct approach, the microorganisms responsible for the synthesis of hazardous monomethylmercury. 2-Bromoethane sulfonate (30 mM), a specific inhibitor of methanogens, increased monomethylmercury synthesis, whereas sodium molybdate (20 mM), a specific inhibitor of sulfate reducers, decreased Hg2+ methylation by more than 95%. Anaerobic enrichment and isolation procedures yielded a Desulfovibrio desulfuricans culture that vigorously methylated Hg2+ in culture solution and also in samples of presterilized sediment. The Hg2+ methylation activity of sulfate reducers is fully expressed only when sulfate is limiting and fermentable organic substrates are available. To date, sulfate reducers have not been suspected of Hg2+ methylation. Identification of these bacteria as the principal methylators of Hg2+ in anoxic sediments raises questions about the environmental relevance of previous pure culture-based methylation work.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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