Friendly yeasts for winemaking: flavours involved in yeast interactions mediated by cooperation or competition events

Abstract

In the last decade yeasts diversity in wine fermentation begun to be considered an alternative to traditional inoculation using pure Saccharomyces cerevisiae strains. Particularly, the non-Saccharomyces yeast Hanseniaspora vineae has been characterized by allowing the growth of other native yeasts compared to the competitive behaviour of most selected Saccharomyces strains. Therefore H. vineae has been considered a friendly yeast for vinification1, being successfully used in winemaking through mixed cultures, giving desirable aromas to wine. In fact, some flavour molecules have been described as potential mediators in yeast interaction. Among them, some positive flavour compounds such as benzenoids and acetate esters of higher alcohols are produced at significantly higher levels in H. vineae compared to S. cerevisiae. By contrast, the production of higher alcohols and short chain fatty acids have been related with more competitive strains that reduce the natural biodiversity in fermentations. The present study focuses on evaluating the impact of higher alcohols derived from aromatic amino acids and their corresponding acetates on the growth of different yeast strains. Three H. vineae and four S. cerevisiae strains applied in oenology were grown in microplates, their optical density was monitored at 620nm for 48 hours in presence of different higher alcohols and their acetylated derivatives in order to analyse their effect. The results obtained suggest that high levels of alcohols and mixed alcohols and acetates caused a decrease in yeast growth for some strains compared with pure acetates. Highly acetylation capacity could be related with the friendly character of H. vineae.

1 Carrau, F. & Henschke, P. A. Hanseniaspora vineae and the concept of friendly yeasts to increase autochthonous wine flavor diversity. Front. Microbiol. 12, 1–8 (2021).