Abstract: Objective: To study the enzyme properties of superoxide dismutase immobilized with chitosan. Methods: Immobilized superoxide dismutase were prepared by different processes. The methods were optimized by comparing their activities. Results: Superoxide dismutase on chitosan with glutaraldehyde as crosslinking agent showed the highest activities and recovery rates.The activity of superoxide dismutase powder immobilized under optimum conditions is 330 U/g,with the recovery rate above 58.33%.The temperature stability and the pH stability of the immobilized enzyme are much better than the free enzyme.And the immobilized enzyme also shows a good storage stability. The immobilized enzyme may be applied repeatedly. It can improve untilization rate. Conclusion: The immobilized superoxide dismutase can be prepared by crosslinking glutaraldehyde on chitosan, and it possesses good properties.

Key words: superoxide dismutase, chitosan, immobilized enzyme