壳聚糖载体的制备及脲酶的固定化研究

Preparation of Chitosan Carrier and Immobilization of Urease

以甲壳素为原料,制备出壳聚糖载体,并对脲酶进行固定化。通过测量悬挂醛基探讨了交联条件对载体性能的影响,优化了脲酶的固定化条件,研究了固定化酶的酶学性质,并与游离酶进行了比较。结果表明,制备载体的最优条件是将微球用6%的戊二醛活化2h,最佳联酶条件是载体与脲酶共反应1h。该固定化酶的最适温度为65℃,最适pH值为6.6,米氏常数为0.009mol/L,较游离酶均有较大改善。热稳定性较游离酶有很大的提高,且具有良好的操作稳定性。

The chitosan beads carrier was prepared with chitin and urease was immobilized on it.The suspension aldehyde group was measured to study the impact of cross-linking condition on carrier characterizations.The immobilization condition for urease was optimized.The characterizations of immobilized enzyme were also measured and compared with the free enzyme.It showed that the optimum condition for carrier preparation was to activate the beads with 6% glutaraldehyde for 2h.Reacting the carrier with urease for 1h could achieve the highest enzyme activity.The optimum temperature was 65℃ and the optimum pH was 6.6.The Km value was 0.009mol/L.The temperature stability of the immobilized enzyme was much better than the free enzyme.And the immobilized enzyme also showed a good operation stability.