Semicontinual synthesis of alkyl galactosides using -galactosidase entrapped in polyvinylalcohol hydrogel

Fungal -galactosidase from Aspergillus oryzae was immobilized into polyvinylalcohol (PVA) hydrogel by LentiKats (R) technology and used for the production of short-chain alkyl glycosides. Ethyl- and propyl--d-galactopyranosides were prepared from lactose (100g/L) and varying initial amounts of alcohol (10-30% v/v) at 40 degrees C and pH 4.5. The entrapped -galactosidase preserved 50% of the initial transgalactosylation activity after 25 repeated cycles in the production of ethyl -d-galactopyranoside. When 5% (v/v) propanol was used as an acceptor, the enzyme activity (30-32U/g immobilized enzyme) remained constant for 25 repeated batch runs. These findings suggest that entrapped -galactosidase into LentiKats (R) has a great potential to be one effective, reusable and easy producible biocatalyst for the production of alkyl glycosides in a large scale.