Effect of ADH7 gene loss on fusel oil metabolism of Saccharomyces cerevisiae for Huangjiu fermentation

Abstract

Hongqu Huangjiu is considered to have higher fusel oil content than other alcoholic beverages. Saccharomyces cerevisiae is the microorganism most responsible for fusel oil production during fermentation. We found that ADH7 gene loss might be closely related to low fusel oil production of S. cerevisiae. The aim of this study was to determine the effect of ADH7 gene on the fusel oil metabolism of S. cerevisiae. S. cerevisiae strain JH301 was used as the research strain with low fusel oil production, S. cerevisiae model strain S288c was used as the control strain. ADH7 gene complementation in the strains JH301-A1, JH301-A2, and JH301-A3 was carried out by rDNA-mediated multicopy integration. The effect of ADH7 gene loss on fusel oil metabolism of S. cerevisiae was analyzed by measuring fusel oil production of gene complementation strains, JH301 and S288c. The results showed that ADH7 gene loss reduced the production of six compounds, mainly including 3-methyl-1-butanol and 2-methyl-1-propanol. In addition, it had a significant effect on fusel oil formed by amino acids rather than formed by glucose. To conclude, these findings show the importance of understanding the molecular mechanism of low fusel oil production in S. cerevisiae.