Untargeted LC-HRMS analyses reveal metabolomic specificities between wine yeast strains selected for their malic acid production

Abstract

The alcoholic fermentation of wine is mostly achieved by the species Saccharomyces cerevisiae that display a large variability for their ability to consume or produce malic acid. To better characterize the metabolism of such group of strains we explored their non-volatile metabolome using an untargeted LC-HRMS approach. The chemical classes and the putative structures of several hundred compounds where annotated using MS2 spectra using the SIRIUS software. By using both supervised and univariate statistical analyses, several metabolic features able to discriminate the two group of strains in several wines were listed. Quantitative enrichment analyses pointed out drastic differences in pantothenic acid metabolism between the two group of strains. In addition, the produced showed important change in their nitrogen composition that might be due to the pH difference in the resulting wines. Altogether this work paves the avenue for better characterizing the biochemical impact of yeast strains that modulate wine acidity.

Keywords: LC-HRMS; Malic acid production; Metabolomics; Pantothenate; Saccharomyces cerevisiae; Wine fermentation.