Breeding of a High Cellulase Producing Strain Aspergillus niger

[Objective] The aim was to lay the theoretical basis for the further development and utilization of cellulase.[Method] Selecting Aspergillus niger W1 with large diameter as original strain,the cellulase activity in different fermentation time of the mutant strain was detected after ultraviolet mutation.[Result] The lethality of A.nige W1 reached 92% through ultraviolet mutation for 10 min.During the 108 h detecting period,the enzyme activity of the original strain W1 and the screened high cellulase producing strain NW1 increased with the prolonging of culture time in certain extent.The enzyme activity of NW1 was highest(1.515U/ml) after culture 84 h with 100 r/min at 28 ℃ and that of W1 reached 0.958 U/ml after culture 84 h,and then that of the two strains decreased slightly with the prolonging of culture time in the following time.The secretion of cellulase from A.nige for 10 min mutation was detected initially by 0.1% Congo red dyeing solution and the result showed that the ability of cellulase secreted by the mutant strain NW1 was strongest and increased 1.62 times than that of the original strain W1.[Conclusion] The mutant strain of A.nige had strong ability of secreting cellulase.