Abstract: The objectives of this study were to reveal the diversity of lactic acid bacteria in the traditional fermented yogurts, and to accumulate food microbial resources. Two fermented yogurt samples were collected from Zhenglan Banner of Xilin Gol League of Inner Mongolia. The lactic acid bacteria in the samples were isolated with traditional purification and culture techniques, and were subsequently identified using 16S rDNA gene PCR and sequencing in combination with the construction of phylogenetic tree. The results showed that a total of 15 strains of lactic acid bacteria were isolated and identified as 9 species belonging to 3 genera. The 3 identified genera were Lactococcus, Leuconostoc and Lactobacillus, and the 9 observed species were Lactococcus lactis subsp. hordniae （n=3）, Lactococcus lactis （n=1）, Lactococcus lactis subsp. cremoris （n=1）, Leuconostoc lactis （n=3）, Leuconostoc mesenteroides subsp. mesenteroides （n=1）, Leuconostoc mesenteroides subsp. dextranicum （n=1）, Lactobacillus plantarum （n=1）, Lactobacillus paracasei （n=3）, and Lactobacillus casei （n=1）. In summary, the collected yogurt samples are rich in lactic acid bacteria resources, and are potential microbial resources for the research, development and industrial production of excellent fermenting agents for traditional dairy products in Inner Mongolia.

Key words: fermented yogurt；lactic acid bacteria；isolation and identification