Researchers have homed in on the yeast genes that give beer and wine a trace of rose or honey flavors.
A KU Leuven-led team used pooled-segregant whole-genome sequencing analysis to uncover Saccharomyces cerevisiae genes that influence the production of phenylethyl acetate, which imparts that rose or honey taste. As they report in mBio this week, they uncovered four quantitative trait loci linked to high phenylethyl acetate production and traced them to two genes, TOR1 and FAS2. TOR1 encodes a phosphatidylinositol kinase homologue, while FAS2 encodes the alpha subunit of fatty acid synthetase.
When the researchers used the CRISPR/Cas9 gene-editing tool to add the TOR1 and FAS2 alleles to parental strains, those strains' production of phenylethyl acetate increased by some 70 percent. This indicated to the researchers that gene editing could speed up the process in which desirable brewing traits are engineering in yeast. "With CRISPR, we never leave a scar," says VIB's Maria Foulquié-Moreno in a statement.
The researchers add that they've partnered with a local Belgian brewery to test how their experimental yeast strains taste.