1993 Fiscal Year Final Research Report Summary
Study on the enzymatic bleaching of kraft pulp
| Project/Area Number |
04660191
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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 |
林産学
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KONDO Ryuichiro Kyushu University, Faculty of Agriculture, Associate Professor, 農学部, 助教授 (80091370)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Enzyme bleaching / Kraft pulp / Phanerochaete sordida / Brightness / Manganese peroxidase |
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| Research Abstract |
To Clarify the role of the excreted extracellular enzymes during long-term incubation in a pulp biobleaching system with white-rot fungi, we have developed a cultivation system using a membrane filter which can prevent the direct contact between hyphae and kraft pulp, but allows extracellular enzymes to attack the kraft pulp. Phanerochaete sordida YK-624 brightened the pulp 21.4points to 54.0% brightness after 5-day in vitro treatment, which was significantly higher than phanerochaete chrysosporium and Coriolus versicolor did during 7-day treatment. These results indicate that cell-free, membrane-filtered components from the in vitro bleaching system are capable of delignifying unbleached kraft pulp. Obvious candidates for filterable reagents capable of delignifying and bleaching kraft pulp are peroxidase and phenoloxidase proteins. Secreted manganese peroxidase activity in the filterable components was substantial during the fungus YK-624 in vitro bleaching. A positive correlation between the level of manganese peroxidase and brightening of the pulp was observed.
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