Characterization of the beta-glucosidase activity produced by enological strains of non-saccharomyces yeasts

Abstract

The beta-glucosidase activities of 20 wine-related non-Saccharomyces yeasts were quantified, characterized,and assessed for their efficiency in releasing aroma-enhancing compounds during the winemaking process. Of these enzymatic activities, the beta-glucosidase activity of Debaryomyces pseudopolymorphus revealed the most suitable combination of properties in terms of functionality at wine pH, resistance to wine-associated inhibitory compounds (glucose, ethanol, and sulfur dioxide), high substrate affinity, and large aglycone-substrate recognition. Its potential as a wine aroma–enhancing enzyme was confirmed by the significantly increasing concentrations of free volatiles (citronellol, nerol, and geraniol) during the fermentation of Chardonnay juice inoculated with both D. pseudopolymorphus and a widely used commercial starter culture strain of Saccharomyces cerevisiae, VIN13.R.R. Cordero Otero, J.F. Ubeda Iranzo, A.I. Briones-Perez, N. Potgieter, M.A. Villena, I.S. Pretorius, and P. van Rensbur