中文摘要：

本研究对采集自蒙古国地区牧民家庭中17份发酵乳样品中的乳杆菌进行了分离、鉴定、生物学特性和耐酸性研究。共分离出45株乳杆菌。通过形态观察、生理生化试验、糖发酵试验及16S rDNA序列分析等研究将这些菌株鉴定为Lactobacillum fermentum（L. fermentum）31 株, L. helveticus 12株, L. plantarum 1株 和L. casei 1株, 所以认为L. fermentum是蒙古国地区传统酸乳中的优势菌群。经pH 为3.0 的人工胃液耐受性试验复筛后发现, 存活率在80%以上的仅1株, IMAU20085的存活率高达81.44%。菌株的分离鉴定以及高耐酸性菌株的筛选, 对我国益生菌资源的保藏和开发有重要的意义, 对我国未来益生菌的开发具有重要价值。

英文摘要：

45 strains of Lactobacillus were isolated from 17 samples of traditional fermented milk in Gobi region of Mongolia. Based on morphological, physiological, biochemistry test and 16S rDNA sequencing analysis, identified as 31 strains of Lactobacillus fermentum（L. fermentum）, 12 strains of L. helveticus, one strain of L. plantarum and 1 strain of L. casei. Survival rate of IMAU20085 is 81.44% in the screening experiment of resistance to the artificial gastric juice （pH 3.0）. The isolation and identification of these strains and the screening of high acid-tolerant strains have important meaning to the preservation and exploitation of probiotic resource.