Purification of β-Glucosidase from Saccharomyces lactis Strains Y-14 and Y-1057A

Two strains of Saccharomyces lactis (Y-14 and Y-1057A), medium (B(m)) and low (B(1)) constitutive producers of beta-glucosidase, were grown in enriched medium. beta-Glucosidase was extracted by autolysis and purified by ammonium sulfate precipitation, gel filtration, and calcium phosphate gel adsorption-elution. The kinetics of release, purification, and stability of beta-glucosidase from strains Y-14 and Y-1057A were compared with the enzyme from strain Y-123. The ability of glycerol, sorbitol, and mannitol to stabilize the beta-glucosidases is presented. A lower molecular weight, labile form of the Y-14 enzyme is demonstrated. Differences in the initial specific activites of beta-glucosidase among the three strains are discussed.