Cellulase production with mixed-culture fermentation of Trichoderma viride and Aspergillus niger

For improving the capability of cellulase production with the mixed-culture fermentation of Trichoderma viride and Aspergillus niger, the inoculation time of A. niger and mixed-culture fermentation time were optimized. The characteristics of cellulase production with mono-fermentation of four strains from T. viride and A. niger and mixed-culture fermentation were studied, and the balance point of the mixed-culture fermentation was established by delaying the inoculation time of A. niger NH11-1. The results showed that the optimal conditions were obtained when the delayed time for A. niger NH11-1 inoculation was 48 h. The optimum conditions for mixed-culture fermentation were as follows: temperature 30 ℃, shaking speed200 r/min, and cultivation time 5 d. Under these conditions, the filter paper activity(FPA) of mixed-culture fermentation was 242.80 U/ml, which was2.66 times than the original strain A. niger NH11-1. The β-glucosidase activity(β-GA) of mixed-culture fermentation reached 297.35 U/ml, which was 1.94 times than the original strain T. viride NM01. The ratio of β-GA to FPA was 1.22, which was in the optimal proportion range of cellulase hydrolysis of natural cellulose(0.12-1.50).