从发酵食品虾酱中筛选到1株高产γ-谷氨酰转肽酶(GGT)的菌株,根据其形态特征、生理生化特性和16SrRNA序列分析鉴定该菌株为枯草芽孢杆菌,并命名为Bacillus subtilis SK11.004。摇瓶实验确定该菌株的优化发酵培养基及发酵条件为:蔗糖25g/L,胰蛋白胨5g/L,玉米浆15g/L,MgSO4.7H2O0.5g/L,K2HPO4.3H2O1g/L,起始pH为7.2,250mL三角瓶装液量30mL,培养温度37℃,发酵培养时间16h,此优化条件下,GGT酶活力可达4.07U/mL。Bacillus subtilis SK11.004菌株生长周期短,产酶量高,应用前景良好。

A strain which produce high γ-glutamyltmnspeptidase (GGT) was isolated from an Asian traditional fermented shrimp paste and was identified taxonomically as Bacillus subtilis according to morphological,physiological and biochemical characters and 16S rRNA sequence analysis.The optimal medium and the optimal fermentation condition were determined in this paper:sucrose 25 g/L,tryptone 5 g/L,corn step liquor 15 g/L,MgSO4·7H2O 0.5 g/L and K2HPO4·3H2O 1 g/L ,30 mL medium in 250 mL flask with initial pH 7.2,37 ℃ incubating temperature and shaking cultivation for 16h. Under optimized conditions,the GGT activity could reach 4.07 U/mL. With short-growth cycle and high GGT-producing ability,Bacillus subtilis SK11.004 presented many potential advantages in food industries.