Anaerobic bacteria are known to produce neurotoxic methylmercury [MeHg] when elemental mercury [Hg(0)] is provided as the sole mercury source. In this study, we examined the formation of MeHg in anaerobic incubations of sediment collected from the San Jacinto River estuary (Texas, USA) amended with aqueous Hg(0) to investigate the microbial communities involved in the conversion of Hg(0) to MeHg. The results show that the addition of the methanogen inhibitor 2-bromoethanesulfonate (BES) significantly decreased MeHg production. The mercury methylation gene, hgcA, was detected in these sediments using archaeal specific primers, and 16S rRNA sequencing showed that a member of the Methanosarcinaceae family of methanogens was active. These results suggest that methanogenic archaea play an underappreciated role in the production of MeHg in estuarine sediments contaminated with Hg(0).

中文翻译：

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受汞污染的河口沉积物中产甲烷菌生产甲基汞

众所周知，当元素汞 [Hg(0)] 作为唯一的汞来源时，厌氧细菌会产生具有神经毒性的甲基汞 [MeHg]。在这项研究中，我们检查了从圣哈辛托河河口（美国德克萨斯州）收集的沉积物在厌氧培养中的形成，这些沉积物用 Hg(0) 水溶液修正，以研究参与 Hg(0) 转化为 MeHg 的微生物群落. 结果表明，添加产甲烷菌抑制剂 2-溴乙磺酸盐 (BES) 显着降低了甲基汞的产量。使用古菌特异性引物在这些沉积物中检测到汞甲基化基因hgcA，16S rRNA 测序显示甲烷八叠球菌科的一个成员产甲烷菌家族活跃。这些结果表明，产甲烷古细菌在受 Hg(0) 污染的河口沉积物中甲基汞的生产中发挥了未被充分认识的作用。