Laccase Fermentation Process By Trametes Pubescens

Laccase is a kind of p-diphenol oxidase widely distributed in nature, which has a variety of biological function and can oxidise six kinds of the substrate. Therefore Laccase has a wide application prospect in the food industry, pulp and paper industry, textile industry, synthetic compounds fields. It has been reported that antibacterial activity and oxidation resistance of δ-viniferin is very good. Laccase produced by T. pubescens can be used in catalysis of δ-viniferin synthesis. Therefore in this experiment we used the t. pubescens as strains which can produce Laccase, and studied the culture conditions, laccase purification, enzyme properties, which will lay the foundations for the enzyme production and application.Through activation and inserting law training of T.pubescens, we observed mycelium morphologic by microscope. T. pubescens mycelia filamentous were branches, septate and had conidiosporangium. Colonial morphology was white villous.Through the research on the fermentation of T. pubescens, we found out the optimum cultivation condition of the T. pubescens. This strain could reach the later log phase after5days cultivation. Optimum cultivation conditions were oscillation cultivation,5%(v/v)inoculation amount,35/250mL fluid amount,28℃, pH6.5,120r/min, CUSO4as best inducers. On the optimum cultivation conditions we could obtain the most laccase activity which was approximately1300U/LThe laccase from T. pubescens was purified using fractional ammonium sulfate precipitation, dialysis, polyethylene glycol condensation. Compared to the crude extract, its purity exhibited a eight-fold improvement and the recovery rate of enzyme activity was68.2%The optimum pH and temperature for the lactase catalyzed the oxidation of methyl catechol are pH4.5and30～60℃respectively. Furthermore, the laccase activity exhibited excellent stability below60℃and pH4.0-5.0.