汞胁迫对Geobacter sulfurreducens PCA汞甲基化作用的代谢组影响

采用新兴的代谢组学技术, 筛选差异性细胞代谢物, 分析甲基汞生成和调控的关键代谢通路。在典型环境污染 浓度 (0~100 μg/L) Hg(II)的 胁迫下, 汞甲基 化微 生物Geobacter sulfurreducens PCA吸附/吸收的Hg(II)成为参与汞还原和甲基化的主要反应物质。初始 Hg(II)浓度为10 μg/L时, G. sulfurreducens PCA达到最高汞甲基化效率3.09%±0.16%。代谢组学数据显示, Hg(II)胁迫对胞内的碳水化合物代谢、核苷酸代谢和氨基酸代谢造成干扰。为了应对Hg(II)胁迫, G. sulfurreducens PCA增大了对能量的需求, 用来调控汞生物甲基化反应, 并对受损DNA进行修复。

Metabolic Influence of Mercury Contamination on Bacterial MercuryMethylation by Geobacter sulfurreducens PCA

Metabolomics, a rising omics approach, was employed to screen out cellular significantly differential metabolites and analyze related metabolic pathways in bacterial Hg-methylating process. Under the stress of Hg(II) at environmentally relevant concentrations (0?100 μg/L), the adsorbed/assimilated Hg(II) was utilized by Hg-methylator of Geobacter sulfurreducens PCA to reduce and methylate Hg(II). The highest efficiency of 3.09%± 0.16% was achieved for bacterial Hg-methylation upon exposure to 10 μg/L Hg(II). Metabolomics data showed that carbohydrate metabolism, amino acid metabolism and nucleotide metabolism were disturbed by Hg(II) stress in the PCA cells. To withstand the stress of Hg(II), G. sulfurreducens PCA increased energy demand for Hg methylation and DNA repair.