Dynamic of Lachancea thermotolerans Population in Monoculture and Mixed Fermentations: Impact on Wine Characteristics

Abstract

Lachancea thermotolerans is a non-Saccharomyces yeast appreciated for its potential of acidification due to the production of lactic acid; however, this species also synthetizes other metabolites that modulate organoleptic wine properties. The aim of this study was to evaluate the strain L. thermotolerans Lt93 to ferment ‘Treixadura’ and ‘Mencía’ musts and its impact on yeast population dynamics and wine characteristics. Fermentations using monocultures of L. thermotolerans Lt93 and S. cerevisiae strains, sequential inoculation and spontaneous process were performed. The dynamic of yeast population and wine composition were analyzed following standard methodology. L. thermotolerans Lt93 was unable to overgrow wild yeast population in ‘Treixadura’ white must; however, with ‘Mencía’ red must, Lt93 was the predominant yeast at the beginning of fermentation and remained at high frequency until the end. Lt93 Treixadura wines had slightly higher acidity and higher content of esters and acids than ScXG3 wines. Lt93 Mencía wines presented higher acidity (10.1 g/L) and 0.8% (v/v) lower ethanol content than Sc71B wines. The content of esters and fatty acids was 3.3 and 4.0 times lower, respectively, in Lt93 than in Sc71B Mencía wines. It was possible to increase wine acidity and modulate the chemical wine profile by using Lt93.