C. Caldini et al., KINETIC AND IMMOBILIZATION STUDIES ON FUNGAL GLYCOSIDASES FOR AROMA ENHANCEMENT IN WINE, Enzyme and microbial technology, 16(4), 1994, pp. 286-291
The biochemical properties of a commercial glycosidase from Aspergillu
s niger (Cytolase PCL5, Genencor) were investigated. The product conta
ins beta-glucosidase, alpha-arabinosidase, and alpha-rhamnosidase acti
vities in a ratio considered ed suitable for aroma enhancement in wine
-making. A kinetic study of these three activities was carried out, wh
ich included determination of kinetic constants; dependence of enzyme
activity and stability on pH and temperature; and enzyme inhibition by
glucose, fructose, glycerol, and sulfurous anhydride. These glycosida
se activities were immobilized to a solid carrier with the aim of deve
loping a continuous process for wine aroma enhancement. Immobilization
was best achieved with silanized bentonite as the solid, activated ca
rrier, with bound glutaraldehyde as the reactive arm at a protein:carr
ier ratio of 0.11. Immobilization reaction was carried out for 48 h at
pH 4 and 30 degrees C. Under these conditions, 16 units of beta-gluco
sidase, 2 units of alpha-arabinosidase, and 4.5 units of alpha-rhamnos
idase per gram of bentonite were immobilized.