双歧杆菌培养基的优化

Optimization of medium for Bifidobacterium infantis

针对双歧杆菌的营养需要,分别采用单因素试验和正交试验,优化培养基成分及用量。得出最优培养基(CPT)配比:大豆蛋白胨1.67%,酪蛋白胨0.83%,乳糖0.5%,酵母浸出粉0.5%,低聚糖0.7%,胡萝卜汁15%。最后测定双歧杆菌在最优培养基中的生长曲线,并同时测定pH和吸光值的变化,确定培养终止时间为12h,菌数可达2.18×109CFU/mL,且发酵培养基具有极显著的增菌效果(p<0.01)。

According to the nutritional needs of B. infantis, the ingredient and dosage of medium were optimized by single factor experimentation and quadratic design respectively. The optimum reproducible medium was as follows： 1.67 % soya peptone, 0.83 % casein peptone, 0.5 % lactose, 0.5 % yeast extract, 0.7 % oligofructose, 15 % carrot juice. Growth curve with optimized reproducible medium were determined, with the change of pH and optics density. According to the growth curve, 12 hours was the terminal time. B. infantis got to 2.18 × 10^9 CFU/mL, and the population of B. infantis were boosted significantly （p〈 0. 01 ）.