Genes controlling hydrolysate toxin tolerance identified by QTL analysis of the natural Saccharomyces cerevisiae BCC39850

In this study, naturalSaccharomyces strains isolated from habitats in Thailand were screened for their tolerance to synthetic hydrolysate toxins (synHTs). TheSaccharomyces cerevisiae natural strain BCC39850 (toxin-tolerant) was crossed with the laboratory strain CEN.PK2-1C (toxin-sensitive), and quantitative trait locus (QTL) analysis was performed on the segregants using phenotypic scores of growth (OD600) and glucose consumption.VMS1,DET1,KCS1,MRH1,YOS9,SYO1, andYDR042C were identified from QTLs as candidate genes associated with the tolerance trait. CEN.PK2-1C knockouts of theVMS1,YOS9,KCS1, andMRH1 genes exhibited significantly greater hydrolysate toxin sensitivity to growth, whereas CEN.PK2-1C knock-ins with replacement ofVMS1 andMRH1 genes from the BCC39850 alleles showed significant increased ethanol production titers compared with the CEN.PK2-1C parental strain in the presence of synHTs. The discovery ofVMS1,YOS9,MRH1, andKCS1 genes associated with hydrolysate toxin tolerance inS. cerevisiae indicates the roles of the endoplasmic-reticulum-associated protein degradation pathway, plasma membrane protein association, and the phosphatidylinositol signaling system in this trait.Key points• QTL analysis was conducted using a hydrolysate toxin-tolerant S. cerevisiae natural strain• Deletion of VMS1,YOS9,MRH1, and KCS1 genes associated with hydrolysate toxin-sensitivity• Replacement of VMS1 and MRH1 with natural strain alleles increased ethanol production titers in the...
Source: European Journal of Applied Physiology - Category: Physiology Source Type: research