Study On Immobilization Technology Of Trichoderma Virde

Cellulase is an important industrial enzyme, and Trichoderma viride produces high level cellulase. As we all known, Cellulase has the great ability of degrading cellulose. It is impotant to immobilize Trichoderma viride for producing cellulase, which probabily have a broad prospect. At present, the embedding method is mainly adopted to immobilize Trichoderma viride. The embedding method can effectively enhance the adaptability of Trichoderma viride against environment. It solves the problem of separating the fermentation liquid from Trichoderma viride and improves the cellulase activity. However, this method is expensive and the immobilized process is complex, what is more, the immobilized gel ball gradually becomes smaller and finally disappears with the application time increase. So the embedding immobilized Trichoderma viride is difficult for large-scale industrial producting cellulase. In order to solve those issues, this paper studied the method of self-flocculation immobilization Trichoderma viride, and then optimized the fermentation medium for producing high activity cellulase.The optimum conditions of producing green spore by Trichoderma viride in PDA solid medium is 10 mL of PDA culture medium in 100 mL Erlenmeyer flask, shading and 25℃. Five days later, the green spores of Trichoderma viride was found distributing in the surface of the culture medium.The Trichoderma viride immobilization conditions were optimized by single factor and orthogonal test methods. The optimization conditions of self-flocculation immobilized Trichoderma viride was pH 6.0,70 mL medium,2.25% glucose,1.50% peptone and immobilization time for six days. The cellulase activity secreted by self-flocculating immobilization Trichoderma viride was about 3.6 U, and the peptone dramatically affected the cellulase activity.After self-flocculation immobilization, the fermentation conditions for producing cellulase by Trichoderma viride was optimized by single factor, orthogonal test and response surface methods. And it was found that the optimization conditions was 4 days, pH 5.0,28℃,60 mL of fermentation medium which constituted by 5% corn flour, 0.15%(NH4)2SO4,0.02% CaCl2,0.11% KH2PO4. Under above fermentation conditions, the cellulase activity could reach 7 U. The factor contribution rate tested by response surface method was (NH4)2SO4> KH2PO4>CaCl2.The cellulase activity produced by free Trichoderma viride, free Aspergillus niger and embedding immobilization Trichoderma viride was 6.4 U,6.19 U and 9.24 U respectively. And the cellulase activity secreted by mobilization Trichoderma viride produced by Jinning Changtai Biological Technological Co. LTD and Yiyuan Kangyuang Bio-Technology Co. LTD was 2.73 U and 2.99 U respectively. It was clear that the cellulase activity secreted by self-flocculation immobilized Trichoderma viride was higher than that secreted both by commercialization immobilized Trichoderma viride and free Trichoderma viride and Aspergillus niger. However, it was lower than that secreted by embedding immobilization Trichoderma viride. It indicated that the technology of self-flocculation immobilization Trichoderma viride had potential application, but it needed improve further.