N^+离子注入诱变选育中性蛋白酶高产菌株及发酵条件的研究  

Breeding of neutral protease producing bacteria by low energy ions implantation in Bacillus subtilis

作　　者：赵丛[1] 张敏[1] 王建玲[1] 杜连祥[1] 

机构地区：[1]天津科技大学生物工程学院天津市工业微生物重点实验室

出　　处：《工业微生物》2008年第3期12-16,共5页Industrial Microbiology

摘　　要：对产中性蛋白酶的枯草芽孢杆菌(Bacillus subtilis)AS1.398进行离子注入诱变,从正突变率较高的注入剂量30~50×1014ions/cm2范围内,筛选出一株高产菌株ZC-7。该菌株在优化了的摇瓶培养基中,培养42h,产酶可达16900U/mL。在7L发酵罐上控制pH6.0~7.0,溶氧10%~20%,以32℃~40℃~30℃变温发酵42h,酶活力最高可达19680U/mL,为初始菌株的2.1倍。An industrial strain with the neutral protease activity of 9360 U/mL was mutagenized by ion beam to increase the production of neutral protease. Mutagenic effects of the mutant were investigated. The experimental results indicated that the survival rate curve took a ＂saddle＂ shape and the activity of neutral protease produced by the mutant strain was up to 16900 U/mL, showing that unique mutation effects of ion implantation were presented. Temperature variation 32℃ --40℃ --30℃, DO （ dissolved oxygen） 10% --20% and pH 6.0--7.0 were estimated as suitable parameters for producing protease after combining with such optimized process as fermentation oscillatory temperature, different original DO and pH. Ultimately, compared with the original bacterium, the activity was up to 19680U/mL which increased with 110.3 percent. The mutant could produce neutral protease stably after 5 passages which indicated that this strain was well adapted to industrial production.

关 键 词：枯草芽孢杆菌 中性蛋白酶 离子注入 诱变选育 

分 类 号：TQ925.2[轻工技术与工程—发酵工程] TQ920.1