Reduction of sulfur dioxide during winemaking is a request from the wine industry. To replace sulfur dioxide, various alternatives exist, including bioprotection by yeast inoculation. This practice consists in adding non-Saccharomyces yeasts directly on the grapes or must.
Controlling the speed of alcoholic (AF) and malolactic (MLF) fermentations in wine can be an important challenge for the production of certain short rotation wines for entry-level market segments. Immobilization techniques for Saccharomyces cerevisiae and Œnococcus œni, the microorganisms responsible for these fermentations, are widely studied for industrial applications. Indeed, these processes allow to accumulate biomass and thus to increase cell densities inducing high fermentation velocities. Recent works have shown the performance of MLF carried out with biofilms of O. œni, immobilized on various supports in a rich medium (MRSm: modified MRS broth with malic acid and fructose).
Currently, to consistently ensure the maintenance of a wine-style while benefiting from the utmost rigor made possible by the winemaking process, the composition of the wine blend is made using sensory control. This is performed after the wine is made with no real possibility of deterministic intervention.
Insufficient acidity in grapes from warm climates/vintages is commonly corrected through addition of tartaric acid during vinification, and less so with other organic acids. An alternative approach involves bio-acidification with the yeast Lachancea thermotolerans (LT) via lactic acid production during fermentation.
Vitamins are major compounds, involved in several prime yeast metabolic pathways. Yet, their significance in oenology has remained mostly unexplored for several decades and our current knowledge on the matter still remaining obscure to this day. While the vitaminic contents of grape musts have been approached in these ancient investigation