Research on Cellulase-producing Conditions by Solid Fermentation of Mixed Strains

Straw stalk powder was used as carbon source,and cellulase-producing conditions by solid fermentation of Aspergillus niger and Tri-choderma viride were investigated.The solid fermentation conditions of mixed strains were optimized by single factorexperiments and orthogonal experiments in four aspects including the inoculation ratio,the mass ratio of bran and straw powder,fermentation time and the filled content of flask.Finally the optimum solid fermentation conditions were summed up as follows: the inoculation ratio(Trichoderma viride∶Aspergillus niger) was 1∶1,the mass ratio of bran and straw powderwas 1∶3,fermentation time was 4 d,and the filled content of flask was 50 mL /1000 mL.Under the above conditions,the activity of FPAase,CMCase and β-Gase were 5.29 IU/mL,9.33 IU/mL and 49.91 IU/mL respectively,which were 2.28～2.47 times,2.39～2.45 times and 1.38～2.09 times as high as that by single strain fermentation.In conclusion,enzyme activity by mixed strains fermentation was higherthan that by single strain fermentation.