壳聚糖酶高产菌株的冷源等离子体诱变及发酵条件的优化

摘要

为获得高产壳聚糖酶的菌株,以实验室分离纯化的鹿皮曲霉(Aspergillus cervinus)ZJOU-AC1为原料,对其进行冷源等离子体诱变和筛选,并设计单因素试验和L9(34)正交试验对诱变菌株进行发酵条件优化.通过实验,确定最佳诱变时间为90 s,获得了1株稳定遗传的突变菌株鹿皮曲霉(Aspergillus cervinus)ZJOU-AC2,其壳聚糖酶活力比原始菌株提高了50.7％,优化后最佳发酵条件为发酵温度为30℃,初始pH 6.0,发酵时间为80h,接种量为3％,此时发酵液中的壳聚糖酶活力比优化前提高了15.07％.%In order to obtain a chitosanase high-yield strain,separated and purified Aspergillus cervinus ZJOUAC1 was used as raw material to carry out cold source plasma mutagenesis and screening,then the single factor and L9 (34) orthogonal tests were used to optimize the fermentation conditions of the mutant strain.Through the experiment,the optimal mutation time was set as 90s.The stable mutant strain of Aspergillus cervinus,ZJOU-AC2,was obtained and its chitosanase activity was increased by 50.7％ compared with the original strain.The optimum fermentation conditions were as follows:the fermentation temperature was 30℃,the initial pH was 6.0,the fermentation time was 90h and the inoculation amount was 3％.At this time,the chitosanase activity in the fermentation broth was improved by 15.07 ％.