双歧杆菌胡萝卜复合汁增菌培养基的优化筛选

The optimization of reproducible carrot juice medium for Bifidobacteria

选择胡萝卜为主要原料,以两歧双歧杆菌(Bbm)和长双歧杆菌(Blm)为试验菌株,研究了胡萝卜汁基础培养基中添加单一营养因子对Bbm菌细胞生长量的影响,进一步利用正交实验筛选出Bbm菌胡萝卜复合汁增菌培养基;利用优选的胡萝卜复合汁增菌培养基对Blm菌进行验证性增菌试验。结果表明:大豆蛋白胨、牛肉浸膏、酵母膏、玉米浆可显著促进双歧杆菌Bbm的细胞增殖(P<0.01)而磷酸氢二钾既能促进Bbm生长,又有缓冲培养基pH值的作用;利用L934筛选出Bbm的胡萝卜复合汁增菌培养基的最佳配比为:在胡萝卜汁中添加0.3%大豆蛋白胨,0.6%牛肉浸膏,0.5%酵母膏,0.4%玉米浆,0.2%磷酸氢二钾,将此培养基经37℃培养12 h,Bbm活菌数4.75×109cfu/mL,Blm活菌数4.82×109cfu/mL。

Carrot was chosen for the experiment. Effects of adding different nutriments in carrot juice （CJ） on the growth of Bbm were examined. The optimum enrichment medium of Bbm was screened by orthogonality test. Blm was validated in the optimum enrichment medium. The results showed that Soya peptone, beef extract, yeast extract, maize hydrolyzates in CJ promoted the growth of Bbm （P〈0.01）, and the addition of K2HPO4 played a role to buffer the medium pH. The optimum enrichment medium obtained by orthogonality test consisted of adding Soya peptone 0.3%, beef extract 0.6%, yeast extract 0.5%, maize hydrolyzates 0.4%, K2HPO4 0.2% in CJ. The live counts cultivated in the optimum enrichment medium for 12 hours at 37℃ were 4.75 × 10^9 cfu/mL of Bbm and 4.82× 10^9 cfu/mL of Blm.