Influence of succinic acid on <i>Oenococcus oeni</i> and malolactic fermentation

As a consequence of the alcoholic fermentation carried out by yeasts in wine, several compounds can be delivered to medium, promoting or inhibiting malolactic (MLF) and lactic acid bacteria, mainly Oenococcus oeni. Succinic is one these an example interaction between yeasts, including non-Saccharomyces species, O. However, influence succinic on MLF has been researched very little as yet. In this work, we study pH oeni CH11 PSU-1 strains, both during resting cell experiments. Moreover, analysed relative expression some significant genes related stress activity determine how strains were affected acid. The results showed that could act inhibitor at concentrations higher than 1 g/L, but it beneficial 0.5 g/L. This variable effect also depends other winemaking conditions, pH, which influences dissociated undissociated forms acids. seems clearer when molar concentration L-malic Experiments with cells have confirmed consumes less Genetic experiments presence (2 g/L), gene hsp18 encoding protein was up-regulated strain CH11, suggesting good response adaptation stress. On hand, mleA mleP, are activity, not acid, except for 4.0. Further research necessary understand better effects MLF.