Abstract:

Based on the Aspergillus niger AS3.350, the mutants were brewed through inducing five treatments.The effect of different mutation methods on enzyme production ability of Xylanase was disscused and obtained mutant strain of xylanase production high ability. The results indicate that, the mutagenesis of UV irradiation was most obvious, and the xylanase activity was 2.18 times of the original strain.Mutagenic effect of the fast neutron irradiation mutagenesis was second, the xylanase activity was 1.72 times of the original strain.After mutagenesis by diethyl sulfatemutagenesis, sodium nitrite, nitrosoguanidine, xylanase activity of the best mutant strains were 1.51 times, 1.46 times, 1.38 times.Physical mutation is more sensitive than chemical mutagenesis on increasing xylanase activity by Aspergillus niger .

Key words: Uvirradiation, Fast neutron irradiation, Nitrosoguanidine mutation, Diethyl sulfate mutagenesis, Sodium nitrite induced