Effects of IAH1 gene deletion on the profiles of Chinese yellow rice wine

Abstract

Acetate esters are the representative flavor-active esters responsible for the fruity odors of Chinese yellow rice wine. The IAH1 gene, encoding an ester-hydrolyzing esterase, was deleted in the industrial Saccharomyces cerevisiae RY-1, and the engineered strain IY-1 was obtained. Then, Chinese yellow rice wine brewing was simulated using the parental strain RY-1 and the engineered strain IY-1, respectively. The results showed that after 6 days of fermentation, fermentation profiles as well as components of the resulting yellow rice wine were so similar except for the ethyl acetate production. The content of ethyl acetate in the yellow rice wine fermented with IY-1 was 47.4 mg·L-1 which increased by 46.3 % than that of the parental strain RY-1, while isoamyl acetate and isobutyl acetate were not detected in both RY-1 and IY-1. The results demonstrate that deletion of IAH1 gene in industrial yeast strain could increase ethyl acetate production in Chinese yellow rice wine. © Springer-Verlag Berlin Heidelberg 2014.