重金属膜輸送遺伝子とキナーゼ遺伝子の共クローニングによる重金属とリン除去の研究

点击翻译按钮获取中文摘要

The purpose of the research project was to develop a technology for simultaneous removal of phosphorus and heavy metals with biotechnological methods. The researcher focused on the phenomenon that bacteria accumulate divalent cations such as Mg^<2+> and Ca^<2+> when they are accumulate polyphosphate in the cells. Therefore, bacterial potential capability of bio-accumulation of divalent heavy metal cations such as Hg^<2+> and Cd^<2+> was investigated.Hg^<2+> and Cd^<2+> resistance of bacterial plasmids were characterized at the first stage of this research project. Phosphate transport genes, a pst operon, were cloned in the most stable cells of an E.coli strain, in the second stage of this project. Thereafter, a mercury resistance operon of Pseudomonas strain were challenged to co-clone the mercury influx transport genes with a polyphosphate kinase gene in a same E.coli strain. The research results obtained from this project were as follows.(1) Transcriptional regulatory protein of the product of cadC gene was characterized as a repressor protein for Cd resistance.(2) One of E.coli strain can possess pst operon and polyphosphate kinase gene stably and can grow actively in diluted LB broth. This bacterial strain uptook phosphate from the medium constitutively.(3) Hyper-sensitive E.coli strain for mercury chloride and methyl mercury was constructed by sitederected deletion of mercury reducing gene (merA).(4) The possibility of simultaneous accumulation of polyphosphate and mercury in the co-cloned E.coli cells was recognized.