Optimization of ethyl hexanoate production in Saccharomyces cerevisiae by metabolic engineering

Abstract

Ethyl hexanoate is one of the most important esters in the strong aromatic Baijiu. In this study, Saccharomyces cerevisiae AY14α was engineered to improve the production of ethyl hexanoate. The CRISPR/Cas9 system was constructed for strain AY14α, and the gene expression intensity was compared at the different integration sites. The hexanoyl-CoA synthesis pathway and alcohol acyltransferase gene were introduced into AY14α, and the recombinant strain Rb-HCSTB accumulated 8.76 ± 1.53 mg/L of ethyl hexanoate. The genes of the hexanoyl-CoA synthesis pathway from different microorganisms and the genes encoding alcohol acyltransferase from different fruits were introduced into AY14α to study their functions. The synthetic pathway of ethyl hexanoate was optimized, and the production of ethyl hexanoate reached 42.35 ± 1.75 mg/L by using the recombinant strain Ck-HCVB-2CbeTer. This work provided a reference for the construction of microorganisms producing ethyl hexanoate and the improvement of ethyl hexanoate production in Baijiu fermentation.