Comparative analyses of microbial community diversities of Tibetan kefir grains from three geographic regions

Abstract

Tibetan kefir grains are the traditional starter for fermented milk products in Tibet, China. To gain a deeper understanding of their bacterial and fungal community diversities, we compared kefir grains from three different regions, Nyingchi, Lhasa and Yangbajing, using high‐throughput sequencing. The results of sequence analysis grouped the reads into four bacterial and four fungal phyla, comprising 34 bacterial and 139 fungal genera, and 44 bacterial and 195 fungal species. Firmicutes and Proteobacteria were two dominant bacterial phyla, and Lactobacillus and Acetobacter were the dominant bacterial genera. Basidiomycota and Ascomycota were the dominant fungal phyla. There was significant difference in the Basidiomycota and Ascomycota among three regions (P < 0.05). A significant difference in genera was observed in the percentage of Saccharomyces, Trichosporon, Aspergillus and Candida between the samples from Nyingchi, Lhasa and Yangbajing (P < 0.05). Based on principal component analysis (PCA), the Tibetan kefir grain samples from Nyingchi could be distinctly differentiated from the other two regions in term of fungal community, but no obvious difference existed in the bacterial population of samples from the three regions.