Succinic acid production by wine yeasts and the influence of GABA and glutamic acid

As a consequence of alcoholic fermentation (AF) in wine, several compounds are released by yeasts, and some of them are linked to the general quality and mouthfeel perceptions in wine. However, others, such as succinic acid, act as inhibitors, mainly of malolactic fermentation. Succinic acid is produced by non-Saccharomyces and Saccharomyces yeasts during the initial stages of AF, and the presence of some amino acids such as & gamma;-aminobutyric acid (GABA) and glutamic acid can increase the concentration of succinic acid. However, the influence of these amino acids on succinic acid production has been studied very little to date. In this work, we studied the production of succinic acid by different strains of non-Saccharomyces and Saccharomyces yeasts during AF in synthetic must, and the influence of the addition of GABA or glutamic acid or a combination of both. The results showed that succinic acid can be produced by non-Saccharomyces yeasts with values in the range of 0.2-0.4 g/L. Moreover, the addition of GABA or glutamic acid can increase the concentration of succinic acid produced by some strains to almost 100 mg/L more than the control, while other strains produce less. Consequently, higher succinic acid production by non-Saccharomyces yeast in coinoculated fermentations with S. cerevisiae strains could represent a risk of inhibiting Oenococcus oeni and therefore the MLF.

Automated summary

Alcoholic fermentation in wine releases various compounds, some of which are linked to wine's quality and mouthfeel, while others, such as succinic acid, act as inhibitors of malolactic fermentation. Succinic acid is produced by non-Saccharomyces and Saccharomyces yeasts during the initial stages of alcoholic fermentation, and the presence of certain amino acids like γ-aminobutyric acid (GABA) and glutamic acid can increase succinic acid concentration. However, the impact of these amino acids on succinic acid production has been minimally studied. This study investigated succinic acid production by different strains of non-Saccharomyces and Saccharomyces yeasts during alcoholic fermentation in synthetic must, and the influence of adding GABA, glutamic acid, or a combination of both. Results showed that non-Saccharomyces yeasts can produce succinic acid in the range of 0.2-0.4 g/L. Furthermore, adding GABA or glutamic acid increased succinic acid concentration by nearly 100 mg/L for some strains compared to the control, while other strains produced less. Consequently, the higher succinic acid production by non-Saccharomyces yeasts in co-inoculated fermentations with S. cerevisiae strains could pose a risk of inhibiting Oenococcus oeni and thus malolactic fermentation.