Mutation breeding of endoglucanase high production strain

Abstract:

[Objective] To establish the rapid screening method of mutant strain of Trichoderma reesei and to screen out mutants with high yield endoglucanase. [Methods] The screening medium of Trichoderma reesei T306 was optimized to establish the rapid screening method, and the mutant strain with high-production endoglucanase was screened through UV mutation. Furthermore, the fermentation medium of mutant strain was optimized. [Results] Addition of 0.1% (w/v) lactose, peptone and sodium deoxycholate was beneficial for the screening of mutants. The mutant strain 0516 was obtained, which had higher production of endoglucanase and obviously varied in colony morphology. The CMCase activity of the mutant was increased by 38.9% compared with original strain. The optimum carbon source and nitrogen source of culture medium were as follows: lactose 1.50%, ammonium sulfate 0.14%, urea 0.05%, and peptone 0.10%. Under these conditions, the CMCase activity of mutant 0516 reached 64.2 U/ mL, which was 2.3 times higher than before. [Conclusion] A method for rapidly screening mutant of Trichoderma reesei with high production endoglucanase was established, and mutant 0516 with higher production of endoglucanase and genetic stability was obtained after UV mutation.