一株异肠球菌SJR-16-1胞外多糖合成条件的研究

Study on the Conditions of Exopolysaccharide Biosynthesis of Enterococcus SJR-16-1

针对分离自内蒙古锡林郭勒牧区马奶酒中的41株乳酸菌进行胞外多糖生物合成能力的的研究,筛选出一株胞外多糖产量高的菌株异肠球菌SJR-16-1,分别改变基础培养基的碳源、氮源以及发酵温度、时间、pH等条件,探讨其对异肠球菌SJR-16-1胞外多糖生物合成能力的影响。优化的培养基的组成为蛋白胨2.0%;葡萄糖1.5%;麦芽糖1.5%;K2HPO40.2%;MnSO.44H2O 0.02%;MgSO.47H2O 0.02%;醋酸钠0.5%;酵母粉0.5%;Tween80 1 mL/L。确定其胞外多糖的最佳生物合成条件为:初始pH6.0,发酵温度35℃,发酵时间14 h,优化的条件显著提高了EPS的合成量。

41strains of lactic acid bacterium comed from Kumiss of the pastoral area in Xilin Guole had been examined for its exopolysaccharide production capacities.It was proved that Enterococcus SJR-16-1 was more procreative.The effects of carbon source,nitrogen source,temperature,culture time and optimum initial pH value of medium on exopolysaccharide produced were studied and a new culture medium for the biosynthesis of exopolysaccharide was formulated.The medium had following composition： peptone,2.0 %;glucose,1.5 %;maltose1.5 %;K2HPO40.2 %;MnSO4·4H2O,0.02 %;MgSO4·7H2O0.02 %;Sodium acetace0.5 %;yeast0.5 %;Tween80,1 mL/L.The best culture conditions for Enterococcus SJR-16-1 to biosynthesis EPS was the constant pH 6.0 of medium with fermentation at 35 ℃ for 14 h.