Abstract:

The aim was to increase the cellulase activity of Aspergillus niger No.Q9, and apply it in the degradation of cellulose resources. Single factor and orthogonal experiments were applied to screen of carbon and nitrogen sources and optimize the fermentation medium and culture conditions of Aspergillus niger No.Q9. The results showed that the optimal carbon source was wheat straw powder and bran, and nitrogen source was (NH4)2SO4. The optimized medium contained 2.00% straw power, 1.50% bran and 1.20% (NH4)2SO4, with pH 5.5. The optimum culture conditions contained 5% inoculum, 170 r/min rotation speed, on 30℃and culturing 3 days. The cellulase activity was increased by 33.46 % from 123.79 to 165.21 U/mL. Aspergillus niger No.Q9 had higher CMCase activity, and its enzyme activity could be enhanced through mutation experiments.