Correlation between Microbial Community Structure And Flavor Components of Traditional Fermented Yak Milk in Gannan

This study aimed to investigate the microbial community structure and flavor compounds, including amino acids, fatty acids, and volatile compounds in traditional fermented yak milk from three distinct regions of Gannan, as well as their relationship. The findings revealed significant variations in flavor compounds, particularly amino acids among the three regions. Similar with the variation in flavor profile, there was also a significant variation in bacterial microbiota among the three regions. The dominant species were identified as Streptococcus salivarius subsp. Thermophiles, Lactobacillus helveticus and Kluyveromyces marxinu, Tausania pullulans in fermented yak milk. Bidirectional orthogonal partial least squares identified five bacterial and three fungi genera as contributors to flavor production, including ethyl acetate and some fatty acids. Furthermore, through regression analysis, we associated the genera of Lactobacillus and Streptococcus with 2,3-pentanedione via 8 KEGG pathways predicted by PICRUST2, such as fatty acid biosynthesis, pentose phosphate, and Alanine, aspartate and glutamate metabolism.