The corrinoid protein, HgcA has been shown to be essential for Hg methylation in anaerobic bacteria. We investigated the diversity of hgcA from temperate and tropical wetland soils where Hg methylation is demonstrated. Sequences obtained from both environments clustered with those from the δ‐Proteobacteria, Chloroflexi and Methanomicrobia with significant overlap in hgcA phylogeny between libraries. Clear differences in hgcA distribution were observed between two highly contrasting sites within a tropical wetland in Everglades National Park, USA. hgcA sequences obtained from the northern site clustered primarily with those of methanogens, while sequences from the estuarine site clustered primarily with sulphate‐reducing bacteria and syntrophs in the δ‐Proteobacteria. Libraries obtained from soils collected from a temperate swamp in Sweden were dominated by hgcA sequences within the δ‐Proteobacteria with hgcA sequences clustering primarily with iron reducers in the upstream portion of the swamp and with sulphate reducers in the downstream portion of the swamp. Interestingly, enrichments prepared from the lower portion of this temperate wetland contained a high abundance of hgcA sequences clustering with methanogens. This first report on hgcA diversity in environmental samples suggests a role in Hg methylation for various phenotypic groups in different portions of wetlands.

中文翻译：

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在湿地土壤中检测关键的Hg甲基化基因hgcA。

业已表明，类固醇蛋白HgcA对于厌氧细菌中的Hg甲基化至关重要。我们调查了温汞和热带湿地土壤中汞甲基化的hgcA多样性。从与来自群集两种环境获得的序列δ-P roteobacteria，Ç hloroflexi和中号ethanomicrobia与显著重叠HGCA库之间的系统发育。在美国大沼泽国家公园的热带湿地中，两个高度对比的站点之间观察到了hgcA分布的明显差异。糖化血红蛋白从北部站点获得的序列主要与产甲烷菌聚在一起，而从河口站点获得的序列主要与δ-P轮状细菌中的硫酸盐还原细菌和突触类聚在一起。从瑞典温带沼泽收集土壤获得文库通过主导HGCA的内序列δ-P roteobacteria与HGCA主要与在沼泽的上游部分，并与在沼泽的下游部分硫酸盐还原铁减速器聚类的序列。有趣的是，从该温带湿地的下部制备的浓缩物含有大量的hgcA序列与产甲烷菌聚类。关于环境样品中hgcA多样性的第一份报告表明，在湿地不同部分的各种表型群体中，汞在甲基化中的作用。