A remarkable variability in the beta-glucosidase activity was observed between 10 wild strains of Oenococcus oeni isolated from wines of the Valpolicella area. The activity occurred in both whole and sonicated cells (intercellular and parietal activities) but not in the supernatants of the cultures. The properties of beta-glucosidase produced by DSTVR 7 and 10 strains include its activation in the presence of ethanol. These strains retained the enzyme activity at oenological conditions (pH value, temperature and ethanol) and showed good malolactic performance when inoculated in wine. None of the tested strains possessed anthocyanase activity. (C) 2003 Elsevier Inc. All rights reserved.