| Project/Area Number |
07808063
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境保全
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| Research Institution | Tohoku Gakuin University |
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Principal Investigator |
ENDO Ginro Tohoku Gakuin University, Dept.of Civil Engineering, Professor, 工学部, 教授 (80194033)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIBASHI Yoshinobu Tohoku Gakuin University, Dept.of Civil Engineering, Professor (10111246)
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| Project Period (FY) |
1995 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1996: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1995: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Heavy metal removal / Mercury transport gene / Polyphosphate kinase gene / Co-cloning, and / Genetic Engineering / heavy metal / mercurials / genetic engineering / plyphosphate / gene cloning / stable expression |
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| Research Abstract |
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.
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