Fermentative aptitude of non-Saccharomyces wine yeast for reduction in the ethanol content in wine

Over the last few decades, there has been a progressive increase in the ethanol content in wines due to global climate change and to the new wine styles that are associated with increased grape maturity. This increased ethanol content can have negative consequences on the sensory properties of the wines, human health, and economic aspects. Several microbiological approaches for decreasing the ethanol content have been suggested, such as strategies based on genetically modified yeasts, the adaptive evolution of yeasts, and the use of non-Saccharomyces yeast. In the present study, we investigated the interspecies and intraspecies variability of some non-Saccharomyces wine yeast species under anaerobic fermentation conditions. Across different grape juices and fermentation trials, Hanseniaspora uvarum, Zygosaccharomyces sapae, Zygosaccharomyces bailii, and Zygosaccharomyces bisporus promoted significant reductions in ethanol yield and fermentation efficiency in comparison with Saccharomyces cerevisiae. The diversion of alcoholic fermentation and the abundant formation of secondary compounds might explain the marked reduction in ethanol yield, as determined through the segregation of the majority of the strains according to their species attributes observed using principal component analysis. These data suggest that careful evaluation of interspecies and intraspecies biodiversity can be carried out to select yeast that produces low-ethanol yields.