1993 Fiscal Year Final Research Report Summary
Ultrastructural Studies on The Protection Mechanism of Chitosan Treated Wood from Fungal Attack and lts Application for Wood Preserving Treatment
| Project/Area Number |
04660189
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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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| Research Field |
材料力学
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| Research Institution | TOTTORI UNIVERSITY |
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Principal Investigator |
SAKUNO Tomoyasu Tottori Univ., Fac.Agriculture, Professor, 農学部, 教授 (10032567)
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| Co-Investigator(Kenkyū-buntansha) |
FURUKAWA Ikuo Tottori Univ., Fac.Agriculture, Professor, 農学部, 教授 (50032313)
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| Project Period (FY) |
1992 – 1993
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| Keywords | Chitosan / Protection Mechanism / Wood Destroying Fungi / Anti-fungal Effects / Combined Treatment / Wood Preservng Method / 抗菌性 |
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| Research Abstract |
In this study, several experiments were carried out. First, the anti-fungal effects of chitosan against typical wood destroying fungi and wood disocoloring molds were investigated. The protection mechanism of chitosan-coated wood surface from fungal attack was then estimated based on the micro-morphological changes. Second, the possibility of developing the lower-toxicity wood-preserving-method (LTWPM) was discussed based on the results of the combined treatment of chitosan and some commercial water-soluble preservatives used for protecting wood surface from fungal attack. The following results were obtained : (1) The anti-fungal spectrum of chitosan was fairly narrowed and selective against the wood rotting fungi. However, chitosan remarkably inhibited the growth of the white-rot fungi, Coriolus versicolor (COV) and Lentinus edodes (LEE).(2) The chitosan-coated wood pieces showed high resistance to COV and the mechansm of which was considered as follows : chitosan inhibits the external secretion of the lignin degradating enzyme, but promotes the secretion of chitosanase, It may have been difficult therefore for the COV fungi to degrade the polysaccharides embedded in the ligni material. In addition, the fungal bodies may have been seriously damaged by its self-secreted chitosanase. (3) The combined application of chitosan and low-concentration CCA solutions to the wood surface showed a remarkable effect in protecting the cell wall materals from the attack f the brown-rot fungi. This experiment suggests the pssibility of developing the LTWPM by supplementing the undergoing wood preserving method with chitosan pre-treatment. (4) The treatment of chitosan on the inoculation surface of the seed-fungal wood pegs (Tanekoma) used in the cultivation of edible mushroom was effective in protecting the pegs from the invasion of harmful mycelia (Trichoderma spp.) thus promoting the mycelial growth of edible fungi within the bed logs.
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