Table 4.

Microbial diversity of fermented yak dairy products and the isolation and identification of lactic acid bacteria.

Yak Dairy Products	Region	Separation and identification technique	Microbial composition	References
Fermented Yak Milk	Tibet	Pure culture method	The dominant flora are 3 species of Lactobacillus (Lactobacillus fermentum, Lactobacillus helveticus and Lactobacillus curvatus) and 5 species of yeast (Saccharomyces cerevisiae, Candida kefyr, Candida lambica, Candida famat and Candida holmii)	(Wu et al., 2009)
	Central Tibet	16S rRNA gene sequence analysis and denaturing gradient gel electrophoresis	The 211 isolated Lactobacillus strains were identified into 6 genera and 22 species and subspecies, among which 117 strains of Lactobacillus species, mainly Lactobacillus and Bifidobacterium	(Ren et al., 2017)
	Gansu	Pure culture method and 16S rRNA gene sequence analysis	The 195 isolated lactic acid bacteria were screened to obtain 5 strains, which were finally identified as Lactococcus lactis subsp. lactis, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus	(Qin et al., 2013)
	Qinghai	16S rRNA gene sequence analysis	The 148 Lactobacillus strains identified belonged to 5 genera and 13 species and subspecies, of which 52 strains were Lactobacillus and 96 strains were coccoid LAB	(Sun et al., 2010)
	Sichuan Qinghai-Tibet Plateau Pastoral Area	Pure culture method and 16S rDNA gene sequence analysis	The 56 isolated strains were further screened and 7 lactic acid bacteria were identified as Lactobacillus paracei, Lactobacillus casei, Enterococcus faecium and Enterococcus stoica	(Wu et al., 2013)
Qu la	Tibet	16S rRNA gene sequence analysis	Isolation of 14 strains of lactic acid bacteria, including Leuconostoc mesenteroides subsp. dextranicum, Leuconostoc pseudomesenteroides, Enterococcus faecium and Lactobacillus plantarum	(Duan et al., 2008)
	Tibet	Pure culture method and ITS/5.8S rDNA gene sequence analysis	The 91 yeast colonies isolated were classified into 7 genera and 10 species, including Kluyveromyces lactis, Pichia fermentans, Saccharomyces cerevisiae, Rhodotorula mucilaginosa, Kluyveromyces marxianus	(Yang et al., 2014)
	three areas in Linzhi, Tibet	High-throughput sequencing technology	The taxonomic composition and abundance of the bacterial communities differed among the samples from the three regions, with the Proteobacteria and Firmicutes being the dominant phylum and the genus Lactobacillus being the dominant genus in all samples	(Chi et al., 2021)
	Tibet	High-throughput sequencing technology	Bacterial diversity and richness in all the samples of Qu la showed a decreasing trend with increasing altitude, and the dominant genera were Lactococcus and Lactobacillus	(Xue et al., 2022)
	Gannan, Gansu	High-throughput sequencing technology	The dominant bacterial phylum were Firmicutes and Proteobacteria, and the dominant genera are Lactobacillus, Acetobacter and Lactococcus	(Cao et al., 2019)
	Gannan, Gansu	Pure culture method and 16S rRNA gene sequence analysis	The 97 isolated lactic acid bacteria were further screened and identified to obtain 6 strains of lactic acid bacteria, including Streptococcus thermophilus, Enterococcus durans and Lactobacillus rei (strains G1, G2, G3 and G4)	(Wen et al., 2020)