Investigation on Cultiurable Microflora in Tibetan Kefir Grains from Different Areas of China

摘要

Four samples of Tibetan kefir grains (TK-ZJUJ 01-04) from Tibet and surrounding areas were investigated via phenotypic and genotypic methods to compare and analyze the diversity of culturable microflora among different origins. As a result, 4 genera of microorganisms from TK-ZJUJ01: Bacillus subtilis (2.9 × 10~7 cfu/mL), Lactococcus lactis (8.2 x 107 cfu/mL), Kluyveromyces marxianus (3.0 × 10~6 cfu/mL), Saccharomyces cerevisiae (9.0 × 10~6 cfu/mL); 4 genera from TK-ZJUJ02: Lactobadllus kefiri (1.0 × 10~8 cfu/mL), Pichia kudriavzevii (5.0 × 10~6 cfu/mL), K. marxianus (1.9 × 10~7 cfu/mL), Kazachstania unispora (6.2 × 10~7 cfu/mL); 6 genera from TK-ZJUJ03: Leuconostoc lactis (4.6 × 10~7 cfu/mL), L. lactis (3.0 × 10~7 cfu/mL), Lactobadllus plantarum (3.0 × 10~7 cfu/mL), K. unispora (3.0 × 10~6 cfu/mL), K. marxianus (2.0 × 10~6 cfu/mL), (1.7 × 10~7 cfu/mL); and 4 genera from TK-ZJUJ04: L. plantarum (1.8 × 10~7 cfu/mL), Acetobacter fabarum (5.0 × 10~6 cfu/mL), K. unispora (6.2 × 10~7 cfu/mL), Pichia guilliermondii (6.2 × 10~7 cfu/mL) were identified. Yeasts like P. kudriavzevii and P. guilliermondii isolated in this study were the first time reported in Tibetan kefir grains. For TK-ZJUJ 01-03, lactic acid bacteria were the major microorganisms, which accounted for more than 50% of all the microbial population, while for TK-ZJUJ04, the largest microbial group was yeasts which accounted for more than 50%. In a word, study of diversity and composition of microflora provided us theoretical foundation for further investigation and application of Tibetan kefir grains.