Preparation of chitosan / CMC capsule and immobilized sucrase

摘要

The immobilized sucrase capsule of 3.0mm diameter was prepared by chitosan and sodium carboxymethyl cellulose (CMC) ion interaction. The immobilization conditions were optimized as following: The sucrase was dissolved in chitosan solution with the concentration of 2.0%. The solution was dropped into the CMC solution with concentration of 1.5%, and the formed capsules were kept hardening for 24h at room temperature. The immobilized enzyme more stable to pH values, the optimum pH of the immobilized sucrase for the enzyme activity was at 3.6∼5.0, and the activity of free enzyme at pH=3.6 became 63% of maximum activity. The immobilize sucrase stored at room temperature retained 80% of its initial activity even after 6d, and free enzyme retained 15% of its initial activity. The enzyme activity of the immobilized sucrase retained almost the same after repeated use, and leaching of the enzyme after 5 cycles of reuse.