乳酸链球菌素由于对革兰氏阳性腐败和致病菌的广谱抗菌活性而作为天然防腐剂在食品工业中广泛使用.为提高乳酸链球菌素发酵水平,以乳酸乳球菌(Lactococcus lactis subsp.lactis) TCCC12001为生产菌株,采用响应面法对发酵培养基进行了优化,确定了该菌发酵的最佳培养基配方(g/L):蔗糖20、酵母粉10、蛋白胨9、牛肉膏5、K2HPO4·12H2O 10、NaCl2、MgSO4·7H2O 0.2.最适发酵条件为:培养基初始pH值7.0,发酵温度30c,种龄10h,接种量3％,培养10h.在此条件下乳酸链球菌素的效价最高达1436IU/mL,比初始效价提高了69％.

Nisin is widely used in the food industry as a natural preservativedue to its broad antibacterial activity against Gram-positive spoilage and pathogenic bacteria. Using Lactococcus lactis subsp. lactis TCCC12001 as the fermentation strain, culture medium composition was optimized by response surface methodology, which contained 20g/L sucrose, 10g/L yeast, 9g/L peptone, 5g/L beef extract, 10g/L K2HPO4·12H2O, 2g/L NaCl and 0.2g/L MgSO4·7H2O. At optimal fermentation condition (initial pH 7.0, fermentation temperature 30℃, seed age 10h and inoculum density 3%). When cultured in the optimum medium, the nisin yield could reach up to 1436IU/ml, which was 69% higher than that without optimization.