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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.

  1. Blum J. E., Bartha R. Effect of salinity on methylation of mercury. Bull Environ Contam Toxicol. 1980 Sep;25(3):404–408. doi: 10.1007/BF01985546. [DOI] [PubMed] [Google Scholar]
  2. Bradford M. M. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976 May 7;72:248–254. doi: 10.1006/abio.1976.9999. [DOI] [PubMed] [Google Scholar]
  3. Compeau G., Bartha R. Effects of sea salt anions on the formation and stability of methylmercury. Bull Environ Contam Toxicol. 1983 Oct;31(4):486–493. doi: 10.1007/BF01622282. [DOI] [PubMed] [Google Scholar]
  4. Compeau G., Bartha R. Methylation and demethylation of mercury under controlled redox, pH and salinity conditions. Appl Environ Microbiol. 1984 Dec;48(6):1203–1207. doi: 10.1128/aem.48.6.1203-1207.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Gunsalus R. P., Romesser J. A., Wolfe R. S. Preparation of coenzyme M analogues and their activity in the methyl coenzyme M reductase system of Methanobacterium thermoautotrophicum. Biochemistry. 1978 Jun 13;17(12):2374–2377. doi: 10.1021/bi00605a019. [DOI] [PubMed] [Google Scholar]
  6. Jensen S., Jernelöv A. Biological methylation of mercury in aquatic organisms. Nature. 1969 Aug 16;223(5207):753–754. doi: 10.1038/223753a0. [DOI] [PubMed] [Google Scholar]
  7. Ridley W. P., Dizikes L. J., Wood J. M. Biomethylation of toxic elements in the environment. Science. 1977 Jul 22;197(4301):329–332. doi: 10.1126/science.877556. [DOI] [PubMed] [Google Scholar]
  8. Robinson J. B., Tuovinen O. H. Mechanisms of microbial resistance and detoxification of mercury and organomercury compounds: physiological, biochemical, and genetic analyses. Microbiol Rev. 1984 Jun;48(2):95–124. doi: 10.1128/mr.48.2.95-124.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Smith R. L., Klug M. J. Reduction of sulfur compounds in the sediments of a eutrophic lake basin. Appl Environ Microbiol. 1981 May;41(5):1230–1237. doi: 10.1128/aem.41.5.1230-1237.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Wood J. M., Kennedy F. S., Rosen C. G. Synthesis of methyl-mercury compounds by extracts of a methanogenic bacterium. Nature. 1968 Oct 12;220(5163):173–174. doi: 10.1038/220173a0. [DOI] [PubMed] [Google Scholar]

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