2002 Fiscal Year Final Research Report Summary
DEVELOPMENT OF A NEW BIOTECHNOLOGY FOR REMEDIATION OF MERCURIALS IN ENVIRONMENT
| Project/Area Number |
13672354
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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 |
Environmental pharmacy
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| Research Institution | SETSUNAN UNIVERSITY |
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Principal Investigator |
HOU Hidemitsu SETSUNAN UNIVERSITY, PHARMACEUTICAL SCIENCES, PRPFESSOR, 薬学部, 教授 (80101294)
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| Co-Investigator(Kenkyū-buntansha) |
KIYONO Masako SETSUNAN UNIVERSITY, PHARMACEUTICAL SCIENCES, ASSISTANT, 薬学部, 助手 (30239842)
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| Project Period (FY) |
2001 – 2002
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| Keywords | BIOREMEDIATION OF MERCURY / POLYPHOSPHATE / MERCURIALS / BIOACCUMULATION OF MERCURY / IMMOBILIZED CELL / mert-merP / merB / ppk |
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| Research Abstract |
To prevent the environmental mercury poisoning incidents, a new biotechnology for treating mercury-polluted environment is becoming increasingly urgent. The present study aims to develop a new biotechnology for mercury remediation.
A new biocatalyst was constructed for mercury bioaccumulation by using a fusion of the merR-o/p-merT-merP-merB gene from Pseudomonas K-62 plasmid pMR26 with a polyphosphate kinase gene, ppk determining polyphosphate kinase from Klebsiella aerogenes. The transcription and transiation of ppk, merT, merP and merB were found to be mercury-inducible. The ppk-specified polyphosphate was identified in cells preinduced by mercury, but not in cells without mercury induction, suggesting that the synthesis of polyphosphate is regulated by merR. In addition, we found the constructed biocatalyst with mer-ppk fusion could accumulate more mercury from the mercury-containing medium, probably via chelation with the ppk-specified polyphosphate.
Next, the feasibility of biological mercury removal from wastewater was examined by using alginate-immobilized bacteria carrying mer-ppk fusion. The immobilized bacteria engineered to express mercury-transport system, organomercurial lyase and polyphosphate efficiently removed organic and inorganic mercury from contaminated wastewater over a wide concentration range of mercurials. Bioaccumulation of mercury was selective comparing to other metals such as Cd^<2+>, Pb^<2+> and Cr^<6+>. The immobilized bacteria could be used repeatedly at least three times without large loss of the activity of mercury removal. From these results, it is concluded that the mer-ppk fusion and the immobilized cells are useful for simultaneous removal of organic and inorganic mercury from contaminated wastewater.
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Research Products
(7 results)
