益生菌Lactobacillus casei Zhang增殖培养基的优化

Study on the Optimization of Enrichment Medium of Lactobacillus casei Zhang

Lactobacillus casei Zhang是一株分离自传统酸马奶中的益生菌。本文研究了不同碳源、氮源、碳氮比例、微量元素及缓冲盐对Lactobacillus casei Zhang增殖培养的效果,并采用响应面法对优选的碳源、氮源和缓冲盐类的组成含量进行优化,得到Lactobacillus casei Zhang的增殖培养基为:葡萄糖20.9g/L、大豆蛋白胨10.45g/L、酵母粉10.45g/L、K2HPO43.5g/L、醋酸钠14.6g/L、柠檬酸钠2.3g/L、MgSO4·7H2O1g/L、MnSO4·5H2O54mg/L、CuSO4·5H2O10mg/L、吐温80为1g/L。LactobacilluscaseiZhang在此增殖培养基中经37℃18h培养活菌数可达到4.78×109CFU/mL,比在MRS中(4.8×108CFU/mL)提高近10倍。

The effects of different carbon source, nitrogen source, proportion of carbon and nitrogen source, microelement and buffer salts on the growth of Lactobacillus casei Zhang isolated from Koumiss were studied. The enrichment medium for Lactobacillus casei Zhang was optimized by response surface methodology and its composition was glucose 20.9 g/L, soy peptone 10.45 g/L, yeast extract 10.45 g/L, K2HPO4 3.5 g/L, sodium acetate 14.6 g/L, sodium citrate 2.35 g/L, MgSO4·7H2O 1.0 g/L, MnSO4·5H2O 54 mg/L, CuSO4·5H2O 10 mg/L, tween 80 1.0 g/L. After cultivated in enrichment medium for 18h at 37℃, the living cells of Lactobacillus casei Zhang were 4.78×10^9 CFU/mL, which was about 10 times higher than in MRS （4.8 ×10^8 CFU/mL）.