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为将脂肪酶固定化,以提高酶的稳定性、使酶可以重复利用和降低生产成本,采用化学共沉淀法制备Fe3O4,以透射电镜、X-射线粉末衍射和红外光谱对所得产品进行表征,并且采用硅烷-戊二醛偶联法和壳聚糖包埋法分别将脂肪酶固定于磁球表面,再以生物拆分(R,S)-1-苯乙醇为模型考察了各种因素对转酯反应的影响。结果表明:化学共沉淀法制备Fe3O4为粒径小于20 nm的磁性纳米粒子;壳聚糖包埋法操作简单、酶载量大;扫描电镜分析揭示固定酶的磁球表面含有大量微孔结构。在最佳条件下,1-苯乙醇的转化率达44.3%,对映体过量值eep为99%,酶的半衰期为121h。反应完成后,施加外磁场可使酶与反应体系迅速分离,固定化酶重复使用11次酶的活性没有明显减少,说明壳聚糖-Fe3O4超顺磁微球固定脂肪酶具有高的活性和稳定性。
In order to immobilize the lipase to improve the stability of the enzyme, make the enzyme reusable and reduce the production cost, Fe3O4 was prepared by the chemical coprecipitation method. The obtained product was characterized by transmission electron microscopy, X-ray powder diffraction and infrared spectroscopy, The lipase was immobilized on the surface of the magnetic sphere by silane-glutaraldehyde coupling method and chitosan embedding method, respectively. The biodegradation (R, S) -1-phenylethanol was used as a model to investigate the effect of various factors Effect of transesterification. The results showed that Fe3O4 was prepared by chemical coprecipitation method. The chitosan embedding method was simple in operation and large in enzyme loading. Scanning electron microscopy analysis revealed that the immobilized enzyme contained a large number of micropores on the magnetic sphere surface. Under the optimal conditions, the conversion of 1-phenyl ethanol reached 44.3%, the enantiomeric excess eep was 99% and the half-life of the enzyme was 121h. After the completion of the reaction, the application of an external magnetic field allows rapid separation of the enzyme and the reaction system, and the activity of the 11-fold enzyme immobilized enzyme was not significantly reduced, indicating that the chitosan-Fe3O4 superparamagnetic microparticle immobilized lipase has high activity and stability Sex.