REPEATED UTILIZATION OF BETA-GLUCOSIDASE IMMOBILIZED ON A REVERSIBLY SOLUBLE-INSOLUBLE POLYMER FOR HYDROLYSIS OF PHLORHIZIN AS A MODEL REACTION PRODUCING A WATER-INSOLUBLE PRODUCT

beta-Glucosidase immobilized on a reversibly soluble-insoluble polymer , G-AS, was utilized for the hydrolysis of phloridzin. The solubility of the immobilized enzyme was dependent on pH and temperature of the s olution: its responsive ranges was between pH 4.0 and 5.0 at 50 degree s C and between pH 3.5 and 4.5 at 4 degrees C. Soluble G-AS had a high er specific activity toward phloridzin than that of the conventional e nzyme immobilized on a water-insoluble carrier. For the hydrolysis of phloridzin at a concentration of 5 g/l (the reaction produces a water- insoluble product from a water-soluble substrate), G-AS was used repea tedly and was easily separated by centrifugation from the reaction mix ture containing a water-insoluble product. In addition, for the hydrol ysis of phloridzin at a concentration of 50 g/l (the reaction produces a water-insoluble product from a slightly water-soluble substrate), G -AS was also used repeatedly and was separated for reuse from the mixt ure of unreacted phloridzin, glucose, and phloretin. The reaction meth od using such a reversibly soluble-insoluble enzyme in a heterogeneous reaction with a water-insoluble product is a potential procedure for repeatedly utilizing the enzyme and separating the water-insoluble pro duct from the suspended mixture.