Impact of inhibitory peptides released by Saccharomyces cerevisiae BDX on the malolactic fermentation performed by Oenococcus oeni Vitilactic F

Abstract

A previous study has shown that the malolactic fermentation (MLF) was inhibited during sequential fermentations performed with the pair Saccharomyces cerevisiae BDX/Oenococcus oeni Vitilactic F in synthetic grape juices. A yeast peptidic fraction with an apparent MW of 5-10kDa was involved in the inhibition. In the present study, the MLF was also inhibited in Cabernet Sauvignon and Syrah wines. The inhibition due to the peptidic fraction was maintained despite high phenolic contents. Kinetic studies showed that the peptidic fraction was gradually released during the alcoholic fermentation (AF). Its highest anti-MLF effect was reached when isolated from late stages of the AF stationary phase. The peptidic fraction was tested in vitro on cell-free bacterial cytosolic extracts containing the malolactic enzyme in a pH range between 3.5 and 6.7. Results showed that it was able to directly inhibit the malolactic enzyme activity with an increasing inhibitory kinetic correlated to the AF time at which it was collected.

Identification of multiple-derived peptides produced by Saccharomyces cerevisiae involved in malolactic fermentation inhibition

“…Since MLF is one of the main energy sources during winemaking, the inhibition of the bacterial growth can be a consequence of the MLF inhibition. Rizk et al (2016) also showed that the same pairing (S. cerevisiae Uvaferm BDX/O. oeni Vitilactic F) maintained the MLF inhibition in Cabernet Sauvignon and Syrah wines.…”

“…This method was implemented and fully described by Rizk et al (2016). It consisted of preparing a cell-free enzymatic extract containing the malolactic enzyme of O. oeni Vitilactic F. The enzymatic extract was recovered in 2 mL of a buffer (0.1 M of citrate buffer pH 3.5, phosphate buffer pH 6 or phosphate buffer pH 6.7).…”

“…However, the experiments were only conducted on yeasts and not on O. oeni. Nehme, Mathieu and Taillandier (2010) demonstrated that S. cerevisiae Uvaferm BDX released a 5-10 kDa peptidic fraction that strongly inhibited the growth and the malate consumption during the MLF performed by O. oeni Vitilactic F. Later on, Rizk et al (2016) showed that this fraction was gradually released during alcoholic fermentation (AF) and reached its highest concentration at late stages of the stationary phase (120 h). It was able to directly inhibit the malolactic enzyme activity in vitro at a pH range between 3.5 and 6.7.…”

“…It was able to directly inhibit the malolactic enzyme activity in vitro at a pH range between 3.5 and 6.7. Rizk et al (2016) were the first researchers to demonstrate that AMPs can inhibit the malate consumption by directly inhibiting the malolactic reaction. These results suggest that in vivo the peptides would enter the cells by mechanisms yet to be identified in order to inhibit MLF.…”

Alternative Methods to SO2 for Microbiological Stabilization of Wine

“…Later, it was found that this fraction reached its highest concentration at late stages of the stationary phase and that it was able to directly inhibit the malolactic enzyme activity in vitro (Rizk et al., ). These results suggest that the peptide enter in the bacterial cytoplasm, by mechanisms yet to be identified, in order to reach the malolactic enzyme.…”