Identification and biodiversity of yeasts from Qula in Tibet and milk cake in Yunnan of China
西藏曲拉和云南乳饼中酵母菌的鉴定及其生物多样性

Abstract: Objective] To analyze the biodiversity and distribution of the yeast species of Qula in Tibet and milk cake in Yunnan, and to provide essential data for the utilization of yeasts in the traditional dairy products of China. Methods] Forty-one yeast strains were isolated from 5 samples of Qula in Tibet and 8 samples of milk cake in Yunnan. The isolates were identified by the large-subunit (26S) rDNA gene D1/D2 domain sequences analysis. Results] The population of yeast in Qula varied from 106 cfu/g to 107 cfu/g. The content of yeast ranged from 102 cfu/g to 106 cfu/g in milk cake. The average population of yeast in Qula was higher than milk cake for 34 folds. These strains were grouped in 12 species belonging to 10 genera. The dominant species in Qula were Pichia fermentans and Saccharomyces cerevisiae, but Candida zeylanoides and Pichia cactophila were major population in milk cake. The results showed that Pichia was the dominant genera both in Qula and milk cake. Conclusion] There existed that yeasts of great biodiversity both of Qula in Tibet and milk cake in Yunnan, but quite different from each other.