SULFATE-REDUCING BACTERIA - PRINCIPAL METHYLATORS OF MERCURY IN ANOXIC ESTUARINE SEDIMENT
SULFATE-REDUCING BACTERIA - PRINCIPAL METHYLATORS OF MERCURY IN ANOXIC ESTUARINE SEDIMENT
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DOI：
10.1128/aem.50.2.498-502.1985
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发表时间：
1985-01-01
影响因子：
4.4
通讯作者：
BARTHA, R
中科院分区：
文献类型：
--
作者：
COMPEAU, GC;BARTHA, R
底物-电子受体组合和特定的代谢抑制剂被施加到缺氧盐沼沉积物中掺入汞2+的努力，以确定，通过直接的方法，微生物负责合成有害的一甲基汞。2-溴乙烷磺酸盐（30 mM），一种产甲烷菌的特异性抑制剂，增加了一甲基汞的合成，而硫酸氢钠（20 mM），一种硫酸盐还原剂的特异性抑制剂，减少了Hg 2+甲基化> 95%。厌氧富集和分离程序产生了脱硫弧菌文化，大力甲基化汞2+在培养液中，也在预消毒的沉积物样品。硫酸盐还原剂的Hg 2+甲基化活性仅在硫酸盐受限且可发酵有机底物可用时才充分表达。到目前为止，硫酸盐还原剂尚未被怀疑与Hg 2+甲基化有关。鉴定这些细菌作为缺氧沉积物中Hg 2+的主要甲基化剂提出了以前纯培养甲基化工作的环境相关性的问题。
Substrate-electron acceptor combinations and specific metabolic inhibitors were applied to anoxic saltmarsh sediment spiked with 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 > 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 substates 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.