Evaluation of ppk-Specified Polyphosphate as a Mercury Remedial Tool

概要

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To evaluate the utility of polyphosphate kinase gene(ppk)-specified polyphosphate in mercury remediation, a fusion plasmid, pMK27, with ppk from Klebsiella aerogenes and mercury transport genes, merT and merP, from Pseudomonas K-62, was constructed. The transcription and translation of ppk, merT and merP were found to be mercury-inducible. The ppk-specified polyphosphate was identified in cells preinduced hy Hg^<2+> but not in cells without mercury induction, suggesting that the synthesis of polyphosphate is regulated by merR. The hypersensitive phenotype to Hg^<2+> shown by bacteria with pMRD141, which contains merT and merP, was almost completely restored to its original levels when the ppk was introduced into the plasmid, suggesting that the Hg^<2+>-toxicity was reduced by the polyphosphafe, probably via chelation formation. Bacteria with pMK27 accumulated approximately 6-fold more mercury than the bacteria with cloning vector, pUC119. These results clearly demonstrate that the polyphosphate is capable of retaining mercury in the Cells without taxing the cells. Based on the results obtained in the present study, the fusion plasmid pMH27 may serve as a strategy for mercury remediation.
公益社団法人日本薬学会の論文
2001-12-01