乳酸乳球菌的高密度发酵研究

Study on the high cell density culture of Lactococcus lactis

摘要: 为了提高一株乳酸乳球菌(Lactococcus lactis SYFS 1.009)单位体积活菌数,通过单因素和正交实验对培养基中各组分进行了研究,并在此基础上,利用3L发酵罐进行恒pH补料实验。结果表明,优化后确定最优的培养基组成为:葡萄糖30g/L,酵母膏40g/L,磷酸二氢钾40g/L,MgSO40.6g/L,MnSO4·H2O 0.1g/L,吐温80 0.5mL/L。此条件下,30℃发酵14h后菌体干重为3.1g/L,是MRS培养基培养条件下的3.4倍(菌体浓度0.9g/L)。在发酵罐恒pH补料12h后,发酵液OD600达到15.3,菌体干重为7.3g/L。

Abstract: In order to improve the cell density of Lactococcus lactis SYFS1.009, the fermentation culture medium and fed-batch culture conditions were studied. The optimum fermentation conditions by single-factor experiment and orthogonal experiment were determined:glucose 30g/L, yeast extract 40g/L, K2HPO440g/L, MgSO40.6g/L, MnSO4·H2O 0.1g/L, Tween 80 0.5mL/L. After cultivated in this medium for 14h at 30℃, DCW (dry cell weight) was 3.1g/L, which was about 3.4 times higher than in MRS (DCW 0.9g/L) . After 12h culture, the DCW was up to7.3g/L and OD600was 15.3.