Biodiversity study of the yeast in fresh and fermented camel and mare's milk by denaturing gradient gel electrophoresis

Abstract

Shubat and Koumiss are traditional fermented products widely consumed in Kazakhstan and Central Asia. Microflora of those fermented products is composed of bacteria and yeasts, which could have deep impacts on beverages quality. Although, the known presence of yeast in such fermented foods, few studies on yeast microflora of Shubat and Koumiss were available. The aim of the study was to identify the main indigenous yeasts in these traditional beverages and additionally, the differences between these 2 types of fermented products. Five samples of fresh and fermented camel and mare's milk from tank were collected in 5 different farms, located in South of Kazakhstan. Farms were selected because of their importance of production of fermented milk at the regional level and the reputation of these products among the consumers. Yeast biodiversity in Shubat and Koumiss was studied using denaturing gradient gel electrophoresis (DGGE). Target DNA bands were identified according to the reference species ladder, constructed in this study. Co-migrating bands present in the DGGE profiles were resolved by species-specific PCR. Galactomyces geotrichum, Kluyveromyces marxianus, Kazachstania unispora, Saccharomyces cerevisiae, Dekkera anomala, Dekkera bruxellensis yeast were identified. Some yeasts were not identified by used primers. In all samples of Shubat and Koumiss the dominant yeast species were Kazakhstania unispora, Kluyveromyces marxianu. Other species were not present in all samples. (Résumé d'auteur

Bacterial microbiota of Kazakhstan cheese revealed by single molecule real time (SMRT) sequencing and its comparison with Belgian, Kalmykian and Italian artisanal cheeses

“…Cheeses, as one of the oldest fermented foods, have a long history from approximately the early Bronze Age [3, 4]. Moreover, the classical Kazakhstan diet comprises a large proportion of local dairy products [5], so the cheese processing technology is traditional. They are often produced by individual households or small regional factories; and they are made in a small scale with naturally occurring bacteria [6].…”

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

“…Yeasts producing koumiss (alcoholic) can ferment lactose or galactose. In the current study, the anomala was isolated from kefir, koumiss, and Shubat [25,32,39]. Feta cheese made from pasteurized ewe's milk contains D. anomala.…”

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

“…Many studies on koumiss bacterial or yeast diversity used culture-or molecular biology-based methods; however, results varied significantly due to differences in the analysis techniques applied, research approaches, and geographic regions [23][24][25][26]. In the current study, we applied long-read SMRT sequencing technology (Pac Bio) with high-resolution phylogenetic microbial community profiling [27] to identify a novel dominant bacterial species, Citrobacter freundii that had not been reported previously; the dominant yeast species were M. caribbica and uncultured Guehomyces.…”

“…D. anomala isolates were obtained from Inner Mongolia Koumiss samples and shown by polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) to be present in an amount of 7.29% [9]; this differs from our sequencing results, which showed amounts of 13-83%. In other milk products, D. anomala was isolated from kefir, koumiss, and Shubat [25,32,38]. Feta cheese made from pasteurized ewe's milk contains D. anomala.…”