Immobilization of inulinase for sucrose hydrolysis

摘要

A commercial inulinase preparation immobilized on various supports was used for sucrose hydrolysis. Entrapment and encapsulation in Ca-alginate and entrapment in an alginate-silicate sol-gel matrix were evaluated. Best results were obtained with Ca-alginate beads. The influence of sodium-alginate concentration on the immobilization yield was assessed. Inulinase entrapped in Ca-alginate beads displayed high activity in the range 50-60℃, whereas the optimum for the free enzyme was 60℃. The optimum pH of the immobilized enzyme was slightly more acidic (4.0) than the one observed for the free form (4.5). The apparent K_M for sucrose of the immobilized inulinase was 184 mM, as compared to 82 mM for free inulinase, as a result of diffusion resistances.