Studies on the conditions of solid-state fermentation for cellulase production by Trichoderma viride and cellulase immobilization

Using wheat bran and corn straw as raw materials,the influence of the ratio of wheat bran to corn straw, fermentation temperature and time,moisture content,initial pH value,nitrogen concentration,on cellulose production by solid-state fermentation of Trichoderma viride were studied in this paper. Based on optimization of solid-state fermentation by single-factor test,orthogonal test was made. The results showed that the optimal solid-state fermentation conditions for cellulase were listed as follows: the ratio of wheat bran to corn straw powder was 4∶ 1,nitrogen concentration was 2%,culture temperature was 28℃,fermentation time was 72 h,initial pH value was 5,inoculum level was 10% and moisture content( based on solid fermentation substrate) was 175%. In this condition,maximum cellulase activity was 1 132. 5 U·g- 1,which was increased 84. 9% than 612. 4 U·g- 1 in initial fermentation condition. Cellulase was immobilized by embedding,cross-linking and embed-cross-linking method,in which embedcross-linking method was the best one.