壳聚糖固定化α-葡萄糖苷酶的研究

以粉末状壳聚糖为载体 ,采用吸附 交联的方法将α 葡萄糖苷酶固定化。在最适固定化条件下 ,室温吸附 6h ,然后与 3 5%的戊二醛在 4 5℃交联 6h ,可得到固定化酶的活力为1430 0U ,酶活力回收率为 59 6 %。通过实验发现 ,与游离酶相比 ,固定化酶的最适 pH向酸性方向移动 0 5pH单位 ,为 pH 4 5;最适作用温度达到 70℃ ,比游离α 葡萄糖苷酶提高 5℃ ;酸碱稳定性、热稳定性及贮存稳定性均有较大提高 ;在 6 0℃操作半衰期为 16 8h

Immobilization of α-Glucosidase on Chitosan

The α-glucosidase (EC 3.2.1.20) was immobilized on chitosan by adsorption and crosslinking. The optimum condition of immobilization was investigated, and the result showed that when 24000U a-glucosidase (0.08mL) was adsorbed with 0.1g dry chitosan at pH6.0 and at room temperature for 6 hours, then treated with 3.5% glutaraldehyde at 45℃ for 6 hours, the activity of immobilized α-glucosidase was 14300 U and the recovery ratio of the activity of nature enzyme was 59.6%. Some properties of the immobilized enzyme were compared with the nature one. The optimum pH of the immobilized enzyme was 4.5, which was 0.5 lower than the nature one's; its optimum action temperature was 70℃, which was 5℃ higher than the nature one's;its stability for enduring pH changing, heat, and long-time storing was much better than the nature one's; and its half-life was 168 hours at 60℃.