Environmental formation of methylmercury is controlled by synergy of inorganic mercury bioavailability and microbial mercury‐methylation capacity
Environmental formation of methylmercury is controlled by synergy of inorganic mercury bioavailability and microbial mercury‐methylation capacity
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甲基汞的环境形成受无机汞生物利用度和微生物汞甲基化能力的协同控制
DOI：
10.1111/1462-2920.16364
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发表时间：
2023
影响因子：
5.1
通讯作者：
Poulin, Brett A.
中科院分区：
文献类型：
--
作者：
Peterson, Benjamin D.;Krabbenhoft, David P.;McMahon, Katherine D.;Ogorek, Jacob M.;Tate, Michael T.;Orem, William H.;Poulin, Brett A.
甲基汞（MeHg）的产生受无机二价汞（Hg（II）i）的生物利用度和微生物群落的汞甲基化能力（由hgcAB基因簇赋予）控制。然而，这些因素的相对重要性及其在环境中的相互作用仍然知之甚少。在这里，宏基因组测序和全因子甲基汞形成实验进行了跨湿地硫酸盐梯度与不同的微生物群落和孔隙水化学。从这个实验中，每个因素对甲基汞形成的相对重要性被分离出来。Hg（II）i生物有效性与溶解有机物组成相关，而微生物Hg甲基化能力与hgcA基因丰度相关。甲基汞的形成对这两个因素有协同作用。值得注意的是，hgcA序列来自不同的分类群，其中没有一个包含异化硫酸盐还原基因。这项工作扩大了我们的地球化学和微生物的限制甲基汞形成原位的理解，并提供了进一步的机制研究的实验框架。
Methylmercury (MeHg) production is controlled by the bioavailability of inorganic divalent mercury (Hg(II)i) and Hg‐methylation capacity of the microbial community (conferred by thehgcABgene cluster). However, the relative importance of these factors and their interaction in the environment remain poorly understood. Here, metagenomic sequencing and a full‐factorial MeHg formation experiment were conducted across a wetland sulfate gradient with different microbial communities and pore water chemistries. From this experiment, the relative importance of each factor on MeHg formation was isolated. Hg(II)ibioavailability correlated with the dissolved organic matter composition, while the microbial Hg‐methylation capacity correlated with the abundance ofhgcAgenes. MeHg formation responded synergistically to both factors. Notably,hgcAsequences were from diverse taxonomic groups, none of which contained genes for dissimilatory sulfate reduction. This work expands our understanding of the geochemical and microbial constraints on MeHg formation in situ and provides an experimental framework for further mechanistic studies.