Removal of ochratoxin A by wine Saccharomyces cerevisiae strains

The aim of this work was to examine two wine strains of Saccharomyces cerevisiae (Syrena LOCK 0201 and Malaga LOCK 0173 strains) and thermally inactivated biomass of bakery yeast (BS strain) for their ability to remove ochratoxin A (OTA) from model YPG, white grape GM, and blackcurrant BM media. The media was initially contaminated by 1 mu g/mL OTA. The influence of OTA on yeast growth parameters, kinetic of fermentation, and amount of ethanol, glycerol, and acids were determined. It was found that both yeast strains were able to decrease the toxin amount in YPG, GM, and BM media. Strain Malaga LOCK 0173 was able to remove 82.8 and 10.7 % ochratoxin A from grape and blackcurrant medium, respectively. In case of Syrena LOCK 0201 strain, the OTA reduction was higher: 85.1 % for grape and 65.2 % for blackcurrant media. From 54.1 to 64.4 % of initial ochratoxin A concentration was removed after the contaminated wine treatment by thermally inactivated baker's yeast strain (BS) cells. The elongation of lag phase in contaminated YPG medium compared on toxin-free medium was noted. In white grape and blackcurrant medium, the differences between the final cell number, fermentation rate, moreover the ethanol, glycerol, and acids production in the medium with OTA and the control were not statistically significant. The results showed that the application of selected strains of yeasts in winemaking involving raw material contaminated with OTA might reduce the toxin contamination as well as the health risk related to human exposure to this toxin. Moreover, the application of heat-inactivated yeast's biomass for toxin adsorption gives new possibilities in oenology.