Metagenetic analysis of the bacterial diversity of Kazakh koumiss and assessment of its anti-Candida albicans activity.

Koumiss, a five-thousand-year-old fermented mare's milk beverage, is widely recognized for its beneficial nutrient and medicinal properties. The microbiota of Chinese and Mongolian koumiss have been largely characterized in recent years, but little is known concerning Kazakh koumiss despite this drink historically originates from the modern Kazakhstan territory. In addition, while koumiss is regarded as a drink with therapeutic potential, there are also no data on koumiss anti-Candida activity. In this context, the aims of the present study were to investigate the bacterial diversity and anti-Candida albicans activity of homemade Kazakh koumiss samples as well as fermented whey and cow's milk, derived from koumiss and propagated for several months. Koumiss bacterial communities were largely dominated by lactic acid bacteria including Lactobacillus sensu lato spp. (69% of total reads), Streptococcus (8.0%) and Lactococcus (6.1%), while other subdominant genera included Acetobacter (2.6%), Enterobacter (2.4%), and Klebsiella (1.5%). Several but not all koumiss samples as well as fermented whey and cow's milk showed antagonistic activities towards C. albicans. Linear discriminant effect size (LEfSe) analysis showed that their bacterial communities were characterized by a significantly higher abundance of amplicon sequence variants (ASV) belonging to the genus Acetobacter. In conclusion, this study allowed to identify the key microorganisms of Kazakh koumiss and provided new information on the possible underestimated contribution of acetic acid bacteria to its probiotic properties.

Profiling of koumiss microbiota and organic acids and their effects on koumiss taste.

BACKGROUND: Koumiss is a naturally fermented mare's milk. Over recent decades, numerous studies have revealed the diversity of lactic acid bacteria in koumiss. However, there is limited information available regarding its secondary major component yeast profile. RESULTS: A total of 119 bacterial and 36 yeast species were identified among the 14 koumiss samples. 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 uncultured Guehomyces. The bacterial and yeast Shannon diversity of the Xilinhaote-urban group were higher than those of the Xilingol-rural group. The most dominant organic acids were lactic, acetic, tartaric, and malic acids. Lactic acid bacteria species were mostly responsible for the accumulation of those organic acids, although Kazachstania unispora, Dekkera anomala, and Meyerozyma caribbica may also have contributed. Redundancy analysis suggested that both bacteria and yeast respond to koumiss flavor, such as Lactobacillus helveticus and Dekkera anomala are associated with sourness, astringency, bitterness, and aftertaste, whereas Lactococcus lactis and Kazachstania unispora are associated with umami. CONCLUSIONS: Our results suggest that differences were observed in koumiss microbiota of Xilinhaote-urban and Xilingol-rural samples. The biodiversity of the former was higher than the latter group. Positive or negative correlations between bacteria and yeast species and taste also were found.

A UPLC-Q-TOF-MS-based metabolomics approach for the evaluation of fermented mare's milk to koumiss.

The fermentation of mare's milk into koumiss produces many beneficial functional compounds depending on the metabolism of the initial microbial flora. In this study, metabolites found in mare's milk and resulting koumiss were identified. Major metabolic pathways in the fermentation were also identified using an UPLC-Q-TOF-MS-based metabolomics method. In total, 354 metabolites were identified: 61 were up-regulated and 105 were down-regulated. Metabolic pathway analyses revealed that c-5-branched dibasic acid metabolism, valine, leucine and isoleucine degradation, arginine and proline metabolism, valine, leucine and isoleucine biosynthesis, vascular smooth muscle contraction, aminoacyl-tRNA biosynthesis and ß-alanine metabolism showed significant increases. A hierarchical cluster analysis of metabolites indicated a clear grouping pattern in which the relative concentrations of p-pyruvate, 20-HETE, 4-aminobutanoate, uracil, acetoacetate, and γ-linolenic acid differed significantly between milk and koumiss. This study provides reference values for metabolic isolates and bioactive compounds purification in mare's milk and koumiss.

Comparison of backslopping and two-stage fermentation methods for koumiss powder production based on chemical composition and nutritional properties.

BACKGROUND: Koumiss is a traditional fermented beverage made from mare's milk. The traditional backslopping method for koumiss production has shortcomings in terms of microbiological diversity and nutritional characteristics. In this study, a two-stage fermentation method was established to scale up the production of koumiss powder. The chemical composition and nutritional properties of a novel two-stage fermentation koumiss powder (TKP) were compared with backslopping koumiss powder (BKP). RESULTS: The TKP exhibited important nutritional and functional properties, including a high percentage of essential amino acids, and high polyunsaturated fatty acid, vitamin, and mineral content. The essential amino acid content of TKP was not significantly different from that of BKP. The oleic acid, linoleic acid, linolenic acid, and water-soluble vitamin content of TKP was higher than that of BKP. The Ca:P ratio of TKP was also close to the optimal Ca:P ratio in humans. CONCLUSION: The novel method could be applied for the scaled-up production of koumiss powder with similar nutritional properties to traditional backslopping koumiss powder. The successful production of koumiss powder could also promote the development of the koumiss industry. © 2019 Society of Chemical Industry.