Study on solid-state fermentation conditions of space mutated Aspergillus niger ZM-8 for cellulase production

Using wheat stalk and wheat bran as the materials, the conditions for producing cellulase by solid fermentation of the space mutant strain Aspergillus niger ZM-8 were studied. The results indicated that the optimum medium for cellulase production were as follow: the mass ratio of wheat stalk to wheat bran was 8:2, 4% (NH4)2SO4 was used as nitrogen source, and the ratio of material to water was 1:2. The optimum culture conditions were as follows: the inoculum was 6%, the initial pH was 6.5, the culture temperature was 28℃ and the culture time was 96 h. Under above condi-tions, the enzyme activity of FPA, CMCase and β-glucosidase was 7.90 U/g, 24.99U/g, and 21.74 U/g, and was increased by 3.0 times, 1.66 times and 2.24 times as compared with the parent strain, respectively.