| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Research Abstract |
Laccase-mediator system is one of the most powerful lignin degrading systems. However, the natural laccase mediator from the culture of lignin-degrading fungi has been not reported yet. To address this question, we considered the assay systems for searching the mediator. First, we developed an assay system using the breaching abilities (brightness and Kappa number) of unbleached kraft pulp treated with laccase-mediator system. However, we rejected this system for the complicated operation. Second, we planed an assay system by using of anthracene oxidation. Laccase could only oxidized anthracene in the presence of mediator, for example 1-hydroxybenzotriazole (HBT). Consequently, this system was simple and quick assay system by using HPLC.
For the mediator candidates, we prepared the ultrafiltration permeate of Trametes versicolor laccase (Fr. B) and water extracts of its fungus (Fr. F). They could act as the laccase mediator for anthracene oxidation (Degradation rate, F : 67.3%, B : 75.5 %). Then, these extracts were fractionated to hexane-soluble (Hex) and ethyl acetate-soluble (EtOAc). Three fractions of them have mediator activities (Degradation rate, F-Hex : 70.0%, B-Hex : 70.0 %, B-EtOAc : 75.6 %). The existence of mediator in these extractives is seen as a strong possibility.
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