Entrap-Immobilization of Invertase on Composite Gel Fiber of Cellulose Acetate and Zirconium Alkoxide by Sol-Gel Process

摘要

We prepared a composite gel fiber by the gel formation of cellulose acetate and zirconium tetra-n-butoxide. Gel fiber is stable in common solvents, phosphate solution, and electrolyte solution. Invertase was entrap-immobilized on the gel fiber. The immobilization was easily performed under the mild conditions. The apparent Michaelis constant (K_m) and maximum reaction velocity (V_(max)) were estimated from Eadie-Hofstee plot for immobilized invertase. The K_m of immobilized invertase was larger than that of native invertase, while the opposite tendency was observed for the V_(max). The activity for the immobilized invertase became higher with increasing fiber diameter. It indicates that the hydrolysis of sucrose occurs in the neighborhood of the fiber surface. The thermal stability of the immobilized invertase was higher than those ofits native counterpart.