Optimization of Cultural Conditions for Ethyl Alcohol Production by Saccharomyces cerevisiae YF1914 in Aerobic Conditions and Its Aroma-Producing Characteristics

Objective:The fermentation conditions of ethyl alcohol produced by Saccharomyces cerevisiae YF1914 were optimized in aerobic conditions, and its aroma-producing characteristics were investigated. Methods:The factors including glucose concentration, nitrogen sources and concentration, temperature, pH, agitation speed and time, which affected the yield of ethyl alcohol, were studied in single factor optimization test. On the basis of single factor test, the aroma products were studied in sorghum hydrolysate medium. Results:By the experiments of single factor, the optimal conditions for ethyl alcohol production in aerobic conditions were as follows:Glucose 350 g/L, yeast extract 41.6 g/L, initial pH5.8, the inoculation ratio of 1%, the volume of liquid of 50 mL/250 mL, incubated at 30℃ for 32 h. Under the condition, the yield of ethyl alcohol reached 124.7 g/L. And, a total of 35 volatile compounds such as β-phenylethanol, ethyl acetate and 3-methylthiopropanol were detected in sorghum hydrolysate medium. Conclusion:The conditions of ethyl alcohol produced by Saccharomyces cerevisiae YF1914 and its aroma-producing characteristics were studied systematically in aerobic conditions, providing theoretical support for the future changes in Baijiu brewing methods.