Immobilized Glucose Isomerase on DEAE Cellulose Beads

Abstract

AbstractPurified glucose isomerase from Actinoplanes missouriensis was immobilized on porous DEAE‐cellulose beads by simple adsorption. The immobilized glucose isomerase retained over 70% of its original activity. The hinderance of immobilized enzyme activity due to pore diffusion and film diffusion was insignificant with the bead size at 35 mesh or smaller. The relative substrate flow rate can be kept at 0.04 cm/s or higher. The optimum pH of the imobilized enzyme did not change, however, the optimum pH range became broader. The broader pH profile indicated that immobilized enzymes are less sensitive to pH change in the substrate. The half life of the immobilized enzyme was at around 1,000 h at 60°C. Cobalt ions are not required for enzyme stability. The cost of using immobilized enzyme on DEAE cellulose beads should be less be than that of the whole cell immobilization system due primarily to the fact that DEAE‐cellulose beads are reusable for immobilization as well as for enzyme purification.