Abstract:

Two lactic acid bacteria (LAB) strains and one yeast strain, previously isolated from traditional fermented
koumiss in Xinjiang, were inoculated into pasteurized mare’s milk in both single and co-cultures to study their growth and
interactions. The LAB strains consisted of Lactobacillus casei MLS5 and Lactococcus lactis WLB5. The yeast strain used
was Kluyveromyces marxianus. The results showed that the growth of Lactobacillus casei MLS5 during fermentation was
significantly promoted by Kluyveromyces marxianus. K. marxianus was significantly inhibited by Lactobacillus casei MLS5,
but was significantly enhanced by Lactococcus lactis WLB5. The viable LAB count of the co-culture of Lactobacillus casei
MLS5 with Lactococcus lactis WLB5 in koumiss was increased when compared with that of the single cultures. The results
of this study can provide useful references to apply yeasts in fermented dairy products and develop new dairy products.

Key words: koumiss, lactic acid bacteria, yeast, interaction