Isolation and Identification of new Lactic Acid Bacteria with Potent Biological Activity and Yeasts in Airag, a Traditional Mongolian Fermented Beverage

Abstract

Thirty-five predominant lactic acid bacteria (LAB) were isolated from six samples of traditional Mongolian Airag (fermented mare's milk) collected in four provinces near Ulaanbaatar, and the bacteria were classified into ten types of LAB by 16S rDNA sequencing. Two types of yeast were also isolated and identified by 26S rDNA sequencing. Two supernatants produced by Lactobacillus hilgardii (Uvu-21) and L. diolivorans (Tuv-33) were found to have potent antibacterial and proteolytic activities, with high thermal and wide pH range stabilities. The activities disappeared after protease treatment, suggesting that the biological activity originated from peptides produced by the LAB. In addition, the fermentation ability of the yeasts was weaker than that of K7 yeast used in sake brewing. These results provide useful information about Airag as a healthy daily beverage in Mongolia.