Denaturing Gradient Gel Electrophoresis Analysis of Lactic Acid Bacteria and Yeasts in Traditional Mongolian Fermented Milk

We analyzed lactic acid bacteria (LAB) and yeast populations in samples of airag, undaa, and hoormog, which are varieties of traditional fermented milk produced in Mongolia. To effectively detect lactobacilli, lactococci/streptococci/enterococci, and leuconostocs for complete analysis of the complex LAB population in airag, we developed two new primer sets and examined these primer sets in three different combinations using denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed the diversity of the LAB and yeast populations in these traditional fermented milk samples; six to 11 LAB and yeast species were detected. The species common to all samples include Lactobacillus helveticus, Leuconostoc mesenteroides, Lactococcus lactis, and Kluyveromyces marxianus. Lc. raffinolactis, Enterococcus faecium/hirae/durans/villoram/ratti, Streptococcus thermophilus, L. kefiranofaciens, L. kefiri/buchneri, Lea. citreum, and Lea. locus were detected in multiple samples, while lactose non-fermenting Saccharomyces cerevisiae was only detected in one sample of hoormog.