Profiling of Koumiss Microbiota and Organic Acids and their Effects on Koumiss Taste

Abstract

Koumiss, a naturally fermented mare’s milk with a distinctive flavor, has been consumed for thousands of years by Mongolian people. To clarify the contribution of microbiota to the taste of koumiss, bacterial and yeast diversity in koumiss were investigated by single-molecule real-time sequencing; the organic acid content was quantified by HPLC, and the taste was analyzed using the SA402B taste-sensing system. The dominant bacterial species in koumiss were Lactobacillus helveticus, Lactobacillus kefiranofaciens, Lactococcus lactis, Lactococcus raffinolactis, and Citrobacter freundii. The main yeast species were Dekkera anomala, Kazachstania unispora, Meyerozyma caribbica, Pichia sp.BZ159, Kluyveromyces marxianus, and unculturedGuehomyces. The most dominant organic acids were lactic, acetic, tartaric, and malic acids. Organic acid accumulation in koumiss was mainly correlated with bacterial, but not yeast, species abundance. Redundancy analysis suggested that both bacteria and yeast respond to koumiss flavor. To prevent excessive sourness, astringency, and bitter taste during koumiss production, the abundance of Lactobacillus helveticus and Dekkera anomala can be controlled; alternatively, Lactococcus lactis and Kazachstania unispora could be increased in the artificial starter culture.