ZIF-8原位自封装固定化脂肪酶的研究

Study on Immobilization of Lipase by In-situ Encapsulation in ZIF-8

该研究使用沸石-咪唑框架-8(zeolitic imidazolate framework-8,ZIF-8)多孔结构材料原位自封装皱褶假丝酵母源脂肪酶(Candida rugosa lipase,CRL)制备固定化脂肪酶(CRL@ZIF-8),利用红外光谱(Fourier transform infrared spectroscopy,FT-IR)、X-射线衍射(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscopy,SEM)等技术研究金属离子来源、反应时间、金属离子浓度和有机连接体的浓度等因素对固定化酶催化活性和形貌特征的影响。确定固定化脂肪酶的最适合成条件:2-甲基咪唑浓度为1.0 mol/L,醋酸锌浓度为0.5 mol/L,反应时间为30 min。在该条件下制备的固定化脂肪酶CRL@ZIF-8酶活力可达到9.8 U/g,其温度稳定性有显著的提高。

In the present study,Candida rugosa lipase(CRL)was immobilized into ZIF-8 by in-situ encapsulation.The effects of metal ion source,reaction time,concentrations of metal ion and organic ligands on the catalytic activity and morphology of immobilized enzyme CRL@ZIF-8 were studied by using Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and scanning electron microscopy(SEM).The conditions of immobilized lipase were obtained:the concentration of 2-methylimidazole was 1.0 mol/L,the concentration of zinc acetate was 0.5 mol/L,and the reaction time was 30 min.The activity of the synthesized CRL@ZIF-8 enzyme reached 9.8 U/g.The temperature stability of the immobilized lipase CRL@ZIF-8 was significantly improved compared with free CRL.