Abstract: Trypsin was irmobilized on chitosan and crosslinked with glutaraldehyde. The optimum conditions for immobilization were as follows: Chitosan was treated with 5% solution of qlutaraldehyde at 30℃ for 8h, then 10ml solution of trypsin (0.3mg/ml pH7. 0 ) was inunobilized on the carrier. Enzyme activity recovery was 67 %～75%. Apparent Michealis constant of ianobilized trypsln k’m=66.67mg/ml, and that of nature trypsin k’m=4.17mg/ml. The optimum temperature of immoilized trypsin was 80t℃, i. e 30℃ higher than natural trypsin 30℃. The optimum pH’s for irmobilized trypsin and natural trypsin were 7.5 and 8.0 respectively. The stability of immobilized trysin was high after storage.

Key words: Chitosan, Immobilizetion, Trypase