Abstract: Chitosan /sodium alginat was selected as a compound wall material of controlled- release microcapsule of glucose oxidase in this study. Influence of different factors to the recovery of enzyme activity and the controlled-release process were investigated. The results showed that the optimal conditions to prepare the controlled- release glucose oxidase were concentra- tion of sodium alginate 2.0%,concentration of chitosan 0.75%,concentration of glucose oxidase 0.6%,pH 5.0,concentration of calcium ion 0.3%,stirring speed 1200r/min. Under this condition the recovery of enzyme activity reached 93.8%,and the controlled-release GOD showed better slow release character.

Key words: glucose oxidase, chitosan /sodium alginate, controlled-release, preparation condition