Biofilm of Oenococcus oeni on yeast derivatives: An innovation to trigger malolactic fermentation and modulate the molecular fingerprint of wines

• Innovative ferment using biofilm-immobilized O. oeni on inactivated or hulls yeast. • Efficient malolactic fermentation of O. oeni developed with yeast derivatives. • Chemical changes in wines depend on the yeast derivative used. The wine industry is undergoing a major transformation and faces a number of challenges. One of these is climate change, which will significantly increase the alcohol content of wines over the coming decades. This rise in alcohol content will be particularly detrimental to the yeasts and bacteria involved in fermentation, especially those responsible for malolactic fermentation (MLF). To remedy this situation, winemakers are already adopting various strategies, such as using ferments selected for their stress resistance and fermentation efficiency. Among these solutions, the use of ferments under the form of single ( O. oeni ) or mixte biofilm combining Saccharomyces cerevisiae and Oenococcus oeni , have demonstrated their ability to trigger MLF and influence the organoleptic characteristics of the wine. In this context, the aim of this research is to design new, innovative and easy-to-use ferments, by developing an O. oeni biofilm on a biotic support consisting of inactivated yeast in the form of bark. The effectiveness of these formulations was evaluated in microvinification, analyzing their impact on MLF and on the molecular diversity of wines (metabolome and volatilome). The results show an acceleration of MLF, attributed to the presence of yeast derivatives, as well as a complexification of the wine’s chemical properties, favored by the effect of biofilm and yeast derivatives. These new starters thus represent a promising solution for optimizing vinification and enriching the sensory profile of wines.