磁性壳聚糖微球的制备及其固定化乳糖酶的研究

Preparation of magnetic chitosan microspheres and study on immobilized lactase

采用水热法制备得到磁性Fe3O4纳米粒子,以壳聚糖、制备的Fe3O4为原料,采用乳化交联法成功制备了磁性壳聚糖微球,并通过SEM、FTIR、VSM、XRD对其进行表征。进一步以制备的磁性壳聚糖微球为载体,采用吸附法制备磁性壳聚糖微球固定化乳糖酶。以酶活力为考察指标,研究了不同固定化条件对制备固定化酶的影响,以及固定化酶的酶学性质。结果表明,乳糖酶的最佳固定化条件为:固定化时间4 h,pH为7.0,乳糖酶酶液浓度为0.6 mg/mL,固定化酶相对于游离酶的pH稳定性和温度稳定性均有一定程度的提高,固定化酶重复使用5次后,酶活仍保留65%以上。

Magnetic Fe3O4 nanoparticles were prepared by hydrothermal method.Chitosan and Fe3O4 as raw materials,magnetic chitosan microspheres were successfully prepared by emulsifying cross-linking method and characterized by SEM,FTIR,VSM,XRD.The magnetic chitosan microspheres were used as carriers to immobilize lactase.The effects of different immobilization conditions on the preparation of immobilized enzyme were studied.The results showed that the optimal conditions for the immobilization of lactase were as follows:the immobilization time was 4 h,the pH was 7.0,the concentration of lactase solution was 0.6 mg/mL,the stability of the immobilized enzyme relative to the free enzyme was improved to a certain extent in both pH and temperature,and the enzyme activity remained above 65% after the immobilized enzyme was used for 5 times.