Identification and characterization of lactic acid bacteria isolated from Tibetan Qula cheese

[摘要] Fourteen strains of Lactic Acid Bacteria (LAB) isolated from Qula, a Tibetan traditional yak cheese, were divided into four groups (A–D) according to morphological and biochemical characteristics. On the basis of the 16S rRNA gene sequence analysis, group A and group B strains were placed in the cluster making up the genus Leuconostoc, which together with Leuconostoc mesenteroides and Leuconostoc pseudomesenteroides, formed a distinct cluster. The group C strain was clearly identified as Enterococcus faecium by forming a very well defined cluster with this species. The group D strains were placed in the lactobacilli cluster with Lactobacillus plantarum and Lactobacillus pentosus being the closely related species. On the basis of DNA-DNA hybridization, strains in the groups A, B, C and D were identified as Leuconostoc mesenteroides subsp. dextranicum, Leuconostoc pseudomesenteroides, Enterococcus faecium and Lactobacillus plantarum, respectively. Leuconostoc mesenteroides subsp. dextranicum was the dominate member of the population.

[学科分类] 微生物学和免疫学

[关键词] DNA-DNA hybridization;lactic acid bacteria;Qula cheese;16S rRNA gene sequence;yak milk