CHARACTERIZATION OF LACTASE IMMOBILIZED ON COLLAGEN: CONVERSION OF WHEY LACTOSE BY SOLUBLE AND IMMOBILIZED LACTASE

Abstract

ABSTRACTS The enzymatic hydrolysis of lactose has been studied using β‐galactosidase ( Aspergillus niger ) immobilized on collagen. The immobilization process employs simple and inexpensive techniques to bind the enzyme to collagen through noncovalent bond formation. The stability and reusability of collagen bound lactase membranes was evaluated in a biocatalytic modular reactor. Little or no loss in reactor activity was observed after storage for a period of 90 days. Following an initial decrease in activity, stable limit activity was maintained over a number of reactor volume replacements. The activity of the fungal lactase in both the soluble and bound states was determined in ultrafiltered acid whey. The catalytic potency of the enzyme, in both states, showed inhibited enzyme activity in acid whey, as compared to aqueous lactose. In the bound state, the enzyme experienced a partial irreversible inhibition.