Acetaldehyde tolerance in Saccharomyces cerevisiae involves the pentose phosphate pathway and oleic acid biosynthesis

To identify genes responsible for acetaldehyde tolerance, genome-wide screening was performed using a collection of haploid Saccharomyces cerevisiae strains deleted in single genes. The screen identified 49 genes whose deletion conferred acetaldehyde sensitivity, and these were termed the genes required for acetaldehyde tolerance. We focused on six of these genes required for acetaldehyde tolerance, ZWF1, GND1, RPE1, TKL1 and TAL1, which encode enzymes in the pentose phosphate pathway (PPP), and OAR1, which encodes for NADPH-dependent 3-oxoacyl-(acyl-carrier-protein) reductase. These genes were not only responsible for acetaldehyde tolerance but also turned out to be induced by acetaldehyde. Moreover, the content of oleic acid was remarkably increased in yeast cells under acetaldehyde stress, and supplementation of oleic acid into the media partially alleviated acetaldehyde stress-induced growth inhibition of strains disrupted in the genes required for acetaldehyde tolerance and OLE1. Taken together, our data suggest that the supply of NADPH and the process of fatty acid biosynthesis are the key factors in acetaldehyde tolerance in the yeast, and that oleic acid plays an important role in acetaldehyde tolerance.