为构建细菌总肽酶活力的测定方法,筛选出肽酶高产的益酵细菌,采用单因素试验和L9(34)正交试验,以反应体系中游离氨基酸总量为肽酶活力指标,对细菌细胞破碎条件进行优化并测定供试菌株的总肽酶活力。结果表明,超声-酶解法破碎细菌细胞的最佳条件为:溶菌酶添加量200μL、超声功率400 W、时间4 min、时间间隔3 s。在此条件下测定153株革兰氏阳性杆菌的总肽酶活力,筛选出肽酶高产革兰氏阳性杆菌11株,分别是DF2-1、ZM1-1、ZM2-1、ZM3-1、DF3-1、DF3-2-1、ZMJ-5、ZMJ-2-6、ZMJ-1-1、DFM-4和WCF-2。

To construct the method of determining global peptidase activity on gram-positive bacillus,a L_9(3~4) orthogonal test based on single-factor experiments was designed to optimize the condition of gram-positive bacillus disruption.The content of total free amino is the main evaluation index.As results,the optimum conditions were additive volume of lysozyme 200 μL,ultrasonic power 400W,ultrasonic time 4 min,time interval 3s.11 G+ bacillus with high global peptidase were obtained from 153 strains through this method,numbered DF2-1,ZM1-1,ZM2-1,ZM3-1,DF3-1,DF3-2-1,ZMJ-5,ZMJ-2-6,ZMJ-1-1,DFM-4,WCF-2.