优良乳酸球菌的筛选及增殖研究

Studies on Selection and Enumberation of Favorable Lactococcus

对本实验室保存的几种能用于酸奶发酵的菌种进行比较,并对其中发酵效果最好的菌种的培养基进行优化。结果表明乳酸球菌Q26的发醇效果最好,其最佳培养基组成为:0.5%蔗糖,1%酪蛋白胨,1%牛肉膏,0.5%酵母膏,2.5%碳酸钙,1%抗坏血酸,5.5%甘薯汁,2.5%番茄汁。用此培养基培养进行增殖,Q26的最高菌数达2.36×109个/mL,比基础培养基的2.74×108个/mL提高约9倍。另生长因子的组成对菌种的增殖有一定的影响。

The selection and enumberation ofLactococcus Q26 was studied. The results showed that the sucrose, N-sources, the ratio of Peptone and Beef extract and Yeast extract, Yam extract, CaCO3, Vc, and Tomato extract of culture medium is 0.5 %, 2.5 %, 2：2：1 （m/m/m）, 5 %, 0.3 %, 0.3 % and 2.5 %, respectively. The highest number of Lactococcus can reach 2.36×10^9/mL.