2004 Fiscal Year Final Research Report Summary
INVOLVEMENT IN SOFT-ROT WOOD DECAY AND APPLICATION OF LACCASE
| Project/Area Number |
13660170
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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 |
林産学
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| Research Institution | KINKI UNIVERSITY |
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Principal Investigator |
TANAKA Hiromi KINKI UNIVERSITY, AGRICULTURE, PROFESSOR, 農学部, 教授 (30140338)
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| Project Period (FY) |
2001 – 2004
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| Keywords | LACCASE / SOFT-ROT / PHENOL OXIDASE / WOOD DECAY / ONE-ELECTRON OXIDATION / HYDROXYL RADICAL |
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| Research Abstract |
The study investigates the possible role of laccase in soft-rot wood decay and examine physical and chemical properties of the enzyme from cultures of soft-rot deuteromycete Graphium sp.M-1-9.
1.The soft-rot deuteromycete Graphium sp. M-1-9 which degraded Japanese beech wood significantly and produced laccase with high activity was selected.
2.The fungus was grown on Duncan's medium containing small wood pieces. Culture filtrate was extracted and obtained ammonium sulfate precipitates.
3.The sample was applied to a Phenyl Sepharose, DEAE Sephaose Cl-6B, and Hi Load 16/10 Phenyl Sepharose HP column chromatographies for purification. The two bands were detected using SDS-PAGE and gel filtration on Superdex 75 PC 3.2/30.
4.Kinetic parameters of the partially purified laccase for oxidation of several substrates were determined. The pH optimum for the partially purified laccase was 4.5.
5.Low-molecular-weight substance that catalyzes a redox reaction to produce hydroxyl radical between oxygen and electron donors was isolated from cultures of the fungus. Hydroxyl radical produced by the low-molecular-weight substance in concert with laccase may play an important role in soft-rot wood decay as in white-rot wood decay.
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