1988 Fiscal Year Final Research Report Summary
Properties of ferric-ion reducing system of T. ferrooxidans and molecular cloning of this enzyme
| Project/Area Number |
62560107
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
発酵・醸造
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| Research Institution | Okayama University |
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Principal Investigator |
SUGIO Tsuyoshi Faculty of Agriculture, Okayama University Associate Professor, 農学部, 助教授 (20033269)
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| Co-Investigator(Kenkyū-buntansha) |
KENJI Inagaki Faculty of Agriculture, Okayama University Instructor, 大学院自然科学研究科, 助手 (80184711)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Thiobacillus ferrooxidans / sulfur oxidation / sulur:ferric ion oxidoreductase / バクテリアリーチング |
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| Research Abstract |
The iron-oxidizing bacterium Thiobacillus ferrooxidans inhabits drainage in acid mines and plays a crucial role in the bacterial leaching of sulfide ores. The value of T. ferrooxidans in bacterial leaching may be due to the ability of this bacterium to oxidize both ferrous ions and reduced sulfur compounds. In order to obtain more valuable strains for bacterial leaching, it is important to study the mechanism of sulfur-oxidation in T. ferrooxidans. The folloing results were obtained in this project. (1) The existence of a novel sulfur-oxidizing enzymes or sulfur:ferric ion oxidoreductase (SFORase) was clarified in T. ferrooxidans AP19-3 and it was purified to an electrophoretically homogenous state. (2) A new route for sulfur oxidation other than that previously reported was proposed in T. ferrooxidans, in which elemental sulfur is oxidized by the cooperation of three enzymes, namely, the SFORase, sulfite:ferric ion oxidoreductase and iron oxidase, and Fe^<3+> and Fe^<2+> play a role as mediator of electrons among these enzymes. (3) Evidence that this new sulfur oxidation route actually involves in aerobic sulfur oxidation by this bacterium was pressented. (4) The mechanism for the inhibition by Cu^<2+> and Co^<2+> of the sulfur metabolism of T. ferrooxidans was clarified. (5) The mechanisms for Mn^<4+> and Mo^<6+> reduction with elemental sulfur by T. ferrooxidans were clarified. (6) N-terminal amino acid sequence of SFORase was determined.
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