Isolation and Identification of a High-yield Ethyl Alcohol Yeast in Aerobic Conditions and Its Biological Characteristics

A yeast named YF1914 with high-yield for ethyl alcohol in aerobic conditions was isolated from laobaigan-flavor Daqu by traditional microbial separation. The yeast was identified as Saccharomyces cerevisiae by colony morphology, microscopic morphology, physiological characteristics and 26S rDNA D1/D2 sequence. The biological characteristics ethanol tolerance, glucose tolerance, acetic acid tolerance, growth temperature and pH were investigated by liquid culture method. The results showed that, the strain was Saccharomyces cerevisiae with high tolerant yeast of ethanol. The highest tolerance of ethanol volume concentration was 18%. It also had high NaCl and glucose tolerance with the highest tolerance concentration of 15% and 80%, respectively. It could grow at 20~50℃ and pH1~10, which indicated a wide temperature and pH adaptability. In summary, these excellent characteristies of the yeast would be conducive to its role in the future changes in Baijiu brewing methods.