鼠李糖乳杆菌耐酸及胆盐能力研究

本实验对来源于婴儿粪便鼠李糖乳杆菌进行耐酸、耐胆盐能力表征及模拟胃液和模拟肠液实验。结果获得鼠李糖乳杆菌菌株B在pH1.8条件下,维持2h,活菌数达到107CFU/ml以上;在pH值为2.2以上的培养基中生长良好,而且随着时间的延长菌株的数量增加。在胆盐浓度在0.5%以下的MRS-broth培养基中鼠李糖乳杆菌B菌株维持4h,活菌数均达到108CFU/ml以上,而且随着时间的延长活菌数均有所增加。模拟胃液和模拟肠液实验结果表明该菌株能够有效通过胃环境,并能在肠道中繁殖。结果可见,鼠李糖乳杆菌B具有较强的酸的胆盐的耐受能力,符合微生态制剂和乳酸菌发酵功能食品菌种的要求。

Study on Acid and Bile Salt Tolerance of Lactobacillus rhamnosus

In this study,effects of different pH,bile salt concentration and simulation human body gastric juice and intestinal tract circumstance on Lactobacillus rhamnosus B from infant intestine were charactered. Under the condition of pH 1.8 maintained for 2 h,the viable count of Lactobacillui rhamnosus strain B reaches more than 107 CFU/ml,and being cultured for 4 h in the MRS-broth(less than 0.5% bile salt),the viable count reach more than 108 CFU/ml,and it increases as time prolonging. The results of simulated gastric juice and intestinal juice experiments showed that the strain can multiply in gastric and intestinal circumstance. The Lactobacillus rhamnosus strain B has strong acid and bile salt tolerance ability and grows better in the circumstance of simulation human body intestinal tract. It is favourable strain for lactic acid bacteria-fermented food.