玉米、豆粕和麦麸抽提物对4株猪源乳酸杆菌耐酸能力的影响

Effect of Corn,Soybean Meal and Wheat Bran Extracts on Viability of Probiotic Lactobacilli under Acidic Conditions

采用模拟胃酸环境,检测饲料原料玉米、豆粕和麦麸抽提物对4株猪源乳酸杆菌耐酸性能的影响。结果表明:在pH 2.5模拟胃酸环境中处理3 h,约氏乳酸杆菌JJB3、SNZ10,罗伊氏乳酸杆菌MNZ8、KNZ4分别经90、30、60 min和30 min完全失活。添加豆粕和麦麸抽提物后,4株乳酸杆菌在pH 2.5模拟胃酸环境中处理3 h后活菌数没有显著变化。玉米抽提物只对JJB3具有很好的保护作用,可以延长SNZ10和KNZ4在酸性环境中的存活时间30 min,对MNZ8 30 min的成活率有一定的提高作用,但是不能延长它的存活时间。进一步的单因子分析表明,葡萄糖浓度变化显著影响乳酸杆菌的耐酸性,游离氨基氮含量对乳酸杆菌成活率几乎无影响。证明饲料原料豆粕和麦麸抽提物作为载体对4株乳酸杆菌耐酸性具有很好的保护作用,可作为提高乳酸杆菌制剂成活率的过瘤胃保护剂。

In this study, the effecs of feed extracts, used as delivery vehicles for probiotic lactobacilli, on the acid tolerance of the cells were evaluated under conditions that simulate the gastric tract. More specifically, the effects of corn, soybean meal and wheat bran extracts on the viability of Lactobacillus johnsonii JJB3, SNZ10, and Lactobacillus reuteri MNZ8, KNZ4 during exposure for 3 h at pH 2.5 were investigated. In the absence of feed extracts Lactobacillus johnsonii JJB3, SNZ10 and Lactobacillus reuteri MNZ8, KNZ4 were demonstrated a significant reduction in their cell population, existing 90, 30, 60 rain and 30 min, respectively. The viability of 4 strains was protected perfectly in the presence of soybean meal and wheat bran extracts. The survival of L. johnsonii JJB3 was very good upon addition of corn extracts, but there were almost no protective effect on L. johnsonii SNZIO and Lactobacillus reuteri MNZ8, KNZ4. In order to evaluate the contribution of the feed constituents on cell survival, the individual effect of glucose and free amino nitrogen （FAN）, which were added at concentrations that correlated to the reducing sugar and FAN content of the feed extracts, was examined. The viability of 4 strains was progressively improved as the glucose concentration increased. Addition of yeast extract, used as sources of FAN, but did not affect 4 strains acid tolerance. The results presented in this study indicated that soybean meal and wheat bran extracts exhibit a significant protective effect on the viability of 4 strains of L. johnsonii and L. reuteri under acidic conditions, which would be used as good delivery vehicles for probiotic Lactobacillus.