Populations and potential association of Saccharomyces cerevisiae with lactic acid bacteria in naturally fermented Korean rice wine

Abstract

The microbial populations focused on predominant yeast species and lactic acid bacteria (LAB) in 15 commercial makgeolli brands, where a fungal starter nuruk was used were examined. Viable yeast counts were obtained on yeast potato dextrose (YPD) and MRS agar containing sodium azide. MRS-C (0.1% cycloheximide supplemented) was used for selective counts of LAB. Saccharomyces cerevisiae was found to be predominant in the 15 samples tested, with an average count of 4.6×10 7 CFU/mL. Contrary to the earlier studies, Lactobacillus plantarum and Weissella cibaria were shown as predominant LAB species with an average count of 1.7×10 7 CFU/mL. Surprisingly, as many as 7 log viable cells/mL were present at the ethyl alcohol concentration of 6-7%. The data from real-time PCR also indicated that the yeast populations remains almost constant during the refrigerated storage of 12 days, while that of LAB decrease slightly first 9 days and increase after then, despite the overall increase in acidity. Data from the differential microbial counts suggest that yeast S. cerevisiae might be associated with 2 LAB species, L. plantarum and W. cibaria, under ethyl alcohol stress during the turbid rice wine fermentation.

Effect of millimeter waves on the microbiological and physicochemical properties of Korean rice wine Makgeolli

“…In a Makgeolli produced using modified-nuruk, the numbers of LAB and yeast cells during fermentation were approximately 7 and 8 log CFU/mL, respectively (14). Consistent with the results of the present study, the numbers of LAB and yeast cells in raw Makgeolli from the market were 5-7 and 7-8 log CFU/mL, respectively (24,25). Although millimeter waves are known to affect microbial growth, both increased and decreased growth of the same microorganisms depending on the fermentation conditions have been reported (26).…”

“…In general, fungi are not detected during Makgeolli fermentation, and the major microorganisms are known to be yeasts and LAB (14,24,25). In a Makgeolli produced using modified-nuruk, the numbers of LAB and yeast cells during fermentation were approximately 7 and 8 log CFU/mL, respectively (14).…”

Pineapple Wines Obtained from Saccharification of Its Waste with Three Strains ofSaccharomyces cerevisiae

“…After 120 h, the viable yeast cells decreased in each sample up to 5.36 3 10 7 , 1.02 3 10 7 , and 2.42 3 10 7 cells/mL for TT, AW, and EM2, respectively (Table 2). These results were in line with those of Yoon et al (2012), who found S. cerevisiae to be predominant with an average count of 4.6 3 10 7 CFU/mL and an ethanol concentration of 6-7% vol/ vol. At this time, the ethanol production increased achieving the concentration of 6.59 and 7.35% vol/vol for AW and TT, respectively (Table 2).…”

“…These results were in line with those of Yoon et al . (), who found S. cerevisiae to be predominant with an average count of 4.6 × 10 7 CFU/mL and an ethanol concentration of 6–7% vol/vol. At this time, the ethanol production increased achieving the concentration of 6.59 and 7.35% vol/vol for AW and TT, respectively (Table ).…”

Development of species-specific PCR primers and polyphasic characterization of Lactobacillus sanfranciscensis isolated from Korean sourdough

“…The diversity of L. sanfranciscensis strains in traditional Korean sourdough could be derived from the broad microbial spectrum in the nuruk used in this study (Jung-Hun, 2000;Song et al, 2013;Yoon et al, 2012). Nuruk is a traditional natural fermentation starter that possesses a diverse microbial population, since various microorganisms are incorporated from the surrounding environment during its production.…”