Modulation of a defined community of Oenococcus oeni strains by Torulaspora delbrueckii and its impact on malolactic fermentation

Identifier:  imarina:9231648

Handle: https://hdl.handle.net/20.500.11797/imarina9231648

Authors:  Balmaseda, Aitor; Rozes, Nicolas; Bordons, Albert; Reguant, Cristina

Abstract:
Background and Aims Torulaspora delbrueckii is being used increasingly as a starter for alcoholic fermentation (AF) because of its chemical modulation of wine. Previous studies on this yeast in a natural must have shown a different Oenococcus oeni population by the end of MLF. In this study we aim to evaluate this aspect in a defined O. oeni strain consortium in a sterile grape must during winemaking. Methods and Results Before commencing AF with either S. cerevisiae or both T. delbrueckii and S. cerevisiae, the must was inoculated with a defined population of O. oeni strains. The use of T. delbrueckii determined the bacterial population at the end of MLF. Also, the inoculation of a selected strain after AF produced wines with different chemical composition to those fermented with the initial bacterial community. Conclusions Different yeast inoculation strategies modulate the O. oeni population, and this has an impact on the chemical composition of the wines. Moreover, the inoculation of a small O. oeni population in must leads to a process similar to spontaneous MLF. Significance of the Study Torulaspora delbrueckii can be used as a tool to modulate the O. oeni population and enhance the aromas related to MLF.