Quantification of glycosidase activity in selected strains of Brettanomyces bruxellensis and Oenococcus oeni

Brettanomyces bruxellensis and lactic acid bacteria are common microorganisms capable of modifying wine aroma and flavor. The activity of beta-glucosiclase against p-nitrophenyl-beta-D-glucopyranoside was determined in a model system for 14 strains of Brettanomyces bruxellensis yeast and 9 strains of lactic acid bacteria (Oenococcus oeni). All Brettanomyces strains and 7 Oenococcus strains exhibited enzymatic activity against this substrate. B. bruxellensis beta-glucosiclase activity was primarily intracellular; O. oeni showed some extracellular activity. Strains showing activity greater than 1000 nmole mL(-1) g dry cell mass(-1) 24 hr(-1) for Brettanomyces, or 100 nmole mL(-1) g dry cell mass(-1) 24 hr(-1) for Oenococcus, were evaluated for their effect on native Viognier grape glycosides. Neither genus was active on Viognier grape glycosides.