Improving flavor metabolism of Saccharomyces cerevisiae by mixed culture with Wickerhamomyces anomalus for Chinese Baijiu making

Yeasts are the most important microorganisms in the fermentation of Chinese Baijiu and the interaction of these yeasts could impact the quality of Baijiu. In this study, we initially characterized the Baijiu yeasts and evaluated their fermentation potential. Wickerhamomyces anomalus GZ3 and Saccharomyces cerevisiae G20 were found to generate high yields of ethyl acetate (2.76 g/L) and 2-phenylethanol, respectively. Results also indicated that the use of W. anomalus along with S. cerevisiae increased volatile compounds production, the maximum ethyl acetate production was observed in S. cerevisiae and W. anomalus at 10(6) :10(6) ratio and have increased by 33 % compared with single culture of W. anomalus. Besides, there was a significant increase of 2-phenylethanol (3.29 g/L) production in single culture of S. cerevisiae with the addition of L-phenylalanine. However, the conversion of L-phenylalanine in mixed culture had significant impact on the yeasts interaction and end flavor of Baijiu. Thus, the present study provided new insights into yeasts interactions in Baijiu fermentation and the effect of some primary metabolites on the end flavor and Baijiu quality. (C) 2018, The Society for Biotechnology, Japan. All rights reserved.