نوع مقاله : مقاله پژوهشی
1 دانش آموخته کارشناسی ارشد، سازمان پژوهش های علمی و صنعتی ایران
2 عضو هیات علمی، سازمان پژوهش های علمی و صنعتی ایران
3 دانش آموخته دکتری، سازمان پژوهش های علمی و صنعتی ایران
عنوان مقاله [English]
In this study, Inulinase enzyme was immobilized on the magnetite nanoparticles functionalized with protein nanoparticles through covalent attachment to improve the stability of the enzyme. The Inulinase was immobilized in order to increase enzyme stability under extreme conditions of industrial processes, reusability, reducing the cost of the final products and the ability to use of continuous bioreactors with immobilized enzyme. In addition, the immobilized enzyme on magnetite nanoparticles can separate from the reaction medium by the magnetic field. Therefore, at the first step, the magnetite nanoparticles were prepared by co-precipitation method. Then, in the second step, a mixture of soy protein isolate and bovine serum albumin nanoparticles were synthesized by desolvation method and then the magnetite nanoparticle’s surface were coated for modification and stabilization. In The third step, the enzyme was immobilized on the surface of the magnetite carrier. In this study, scanning electron microscope (SEM) and dynamic light scattering (DLS) were used for analyze the particle size, shape, morphology and functional characteristics of magnetite and protein nanoparticles and enzyme immobilization in all steps of preparation. After enzyme immobilization the properties were compared with the free enzyme. The results implied that the immobilized enzyme retained more than 50% of its initial activity at 650C while the free enzyme retained only 17% of its activity. The half-life of immobilized enzyme at 650C, increased up to 6 times in comparison with the free enzyme. The immobilized inulinase retained more than 60% of its activity after 12 cycles. The activity of the enzyme, kinetic parameters (Vmax, Km) were assayed and the results revealed better operational stability compared to free enzyme.