Diversity analysis and function prediction of lactic acid bacteria in natural fermented dairy products in Mongolia

Abstract

This study focused on the research of lactic acid bacteria (LAB) diversity and its function of Mongolian natural fermented dairy products. A total of 24 samples of airag (fermented mare milk) and 15 samples of tarag (fermented cow milk) were gathered from multiple regions. Based on pure culture technology, 489 strains of LAB were isolated and preserved, among which Lactobacillus helveticus and Lacticaseibacillus paracasei were the dominant species of culturable LAB. The dominant species in culture-independent results are consistent with pure culture. We observed significant variations in the abundance of Lactobacillus kefiranofaciens, Lactobacillus delbrueckii, and Streptococcus thermophilus across diverse dairy sources. We also found that there were abundant tetrahydrofolate synthesis pathways in Mongolian airag, and many metabolic pathways related to antioxidant, anti-inflammatory and cholesterol-lowering effects through the functional annotation. In conclusion, the diversity of LAB in Mongolian fermented dairy products was influenced by the milk source. It supplemented the understanding of microbial diversity and functional characteristics in natural fermented dairy product in remote areas of Mongolia.