Screening of Aspergillus niger mutants with high activity of cellulase

A mutant strain named ZM-8 with high activity of cellulase was selected from Aspergillus niger by space-flight mutation.The conditions of solid fermentation for cellulose production were corn stalk power 60%,wheat bran 40%,and tap water 250%(v/w),(NH4)3PO4 2%,pH6.0 at 30℃ for 72 hours.Under these conditions,its enzyme activities of cellobiohydrolase(C1),exoglucanase(CMCase) and β-glucosaccharase(β-Glase)toward filter paper reached 110.2 U/g,389.9 U/g,489.3 U/g and 1208.1 U/g and increased respectively by 2.1,3.5,1.7,1.8 times compared to parent strain.It has very high stability of cellulase production after transferring for 5 generations and fermentation in solid medium.The results showed that the mutant A.niger is a preferable strain for the further application of crop stalks.