| Project/Area Number |
17510069
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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 technology/Environmental materials
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| Research Institution | Okayama University |
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Principal Investigator |
TAKEUCHI Fumiaki Okayama University, Health and Environment Center, Associate Professor (90294446)
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| Co-Investigator(Kenkyū-buntansha) |
SUGIO Tsuyoshi OKAYAMA UNIVERSITY, Graduate School of Natural Science and Technology, Technology Professor (20033269)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥4,040,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥240,000)
Fiscal Year 2007: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | iron oxidizing bacterium / Acidithiohacillus ferrooxidans / Bioleaching / Rioremediation / Mercury-Resistant Strains / Electrochemical cultivation / Mercury-polluted soil treatment / Conner bioleaching |
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| Research Abstract |
Iron-oxidizing bacterium, Acidithiobacillus ferrooxidans, is one of the most important bacteria for the bioleaching of copper and gold ores. In order to use the mercury reducing activity of A. ferrooxidans for the bioremediation of mercury, mercury-resistant A. ferrooxidans strains SUG 2-2 and MON-1 were screened among 150 strains of iron-oxidizing bacteria isolated from natural environments. It was found that strains SUG 2-2 and MON-1 have a novel ferrous iron-dependent mercury volatilization activity as well as an NADPH-dependent mercury reductase activity. Strain MON-I has volatilization activity an organomercurial lyase-like activity by cytochrome c oxidase. Nearly 100% of the total mercury in mercury-polluted soil or mercury wastewater was volatilized and recovered by incubating SUG 2-2 or MON-1 cells. suggesting that these mercury-resistant strains can be used for the bioremediation of inorganic and organic mercurial compounds.
A. ferrooxidans strain D3-2, which has a high copper bioleaching activity, was isolated from a low-grade sulfide are dump in Chile. Since sulfite ion is a highly toxic intermediate produced during sulfur oxidation that strongly inhibits iron oxidase activity, these results confirm hat strain D3-2, with a unique sulfite resistant-sulfite oxidase, was able to solubilize more copper from chalcopyrite than strain ATCC 23270, with a sulfite-sensitive sulfite oxidase. An electric cultivation device was developed. This was useful for the enzymatic refinement and the Applied technology.
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