Document Type : Regular Article
Payame Noor University
payame Noor University
In this paper, covalent immobilization of beta amylase enzyme on the surface of modified magnetic nano particles (ZnFe2O4@SiO2-NH2) is reported. For doing so, at first, the magnetic nanoparticles of ZnFe2O4 were synthesized by chemical co-precipitation method and then tetraethyl orthosilicate (TEOS) and 3-aminopropyltriethoxy silane (APTES) were used for modification of ZnFe2O4 nanoparticles with silica and amine groups (ZnFe2O4@SiO2-NH2). Then, the aminated surface of ZnFe2O4 nanoparticles was exposed to beta amylase immobilization using trichlorotriazine (TCT) as covalent agent. The immobilized beta-amylase enzyme was characterized by techniques such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The kinetics studies corroborate the Michaelis-Menten model and show much progress in the efficiency of immobilized enzyme compared to the free enzyme. Also, the thermal stability of the beta-amylase enzyme is increased after immobilization. By applying a magnetic active support, simple and facile separation of beta-amylase from the reaction mixture and higher catalytic activity is possible. The highest activity for immobilized beta-amylase enzyme is observed at pH and temperature of 7.0 and 40 °C, respectively.