Remediation of environmetal pollution by the recombinant Escherichia coli accumulating cesium in the cell

本研究的目的是设计和构建重组大肠杆菌，在细胞中积累铯离子。我们发现，在钼和锰的情况下，金属转运体和金属结合蛋白的基因组变化增加了大肠杆菌细胞内金属的水平。为了鉴定大肠杆菌中铯转运体和铯结合蛋白的基因，我们进行了转录组分析。结果表明，添加氯化铯后，三个基因（每个基因编码一个假定的金属结合转录因子）增加。这些基因的缺失增加了对高浓度铯的敏感性。这些结果表明，所鉴定的基因参与了大肠杆菌对细胞外铯的反应，并且是细胞内铯离子在细胞内积累的基因组变化的靶点。

The purpose of this study is to design and construct the recombinant Escherichia coli, accumulating cesium ion in the cell. We showed genomic changes of metal-transporter and metal-binding protein increase the level of intracellular metal in E. coli in the cases of molybdenum and manganese. To identify the genes for cesium-transporter and cesium-binding protein in E. coli, we carried out transcriptome analysis. The result showed three genes, each encoding a putative metal-binding transcription factor, were increased by addition of cesium chloride. The deletion of these genes each increased the sensibility to high concentration of cesium. These results suggest that the identified genes involved in response to extracellular cesium in E. coli and are targets for genomic change to accumulate intracellular cesium ion in a cell.