The study of Fe₃O₄@SiO₂-NH₂ nano-magnetic composite modified by glutaraldehyde to immobilized penicillin G acylase

Authors: MONIER ALHADI ABDELRAHMAN MOHAMMED, ZHENBIN CHEN, KE LI, BOYUAN ZHANG

Abstract: Preparation of biocatalyst dependent on immobilized penicillin G acylase (PGA) was of substantial importance for proteomic research, organic synthesis, and industrial applications. Herein, we developed an easy method for nano-magnetic composite to immobilize PGA. Fe₃O₄ nano-magnetic particles were co-precipitated with Fe³⁺ and Fe²⁺ in an ammonia solution (NH₃) and treated with silicon dioxide (SiO₂), which was developed using the sol-gel process. Thereafter, 3-aminopropyltriethoxysilane (APTES) was used to modify the silica-coated Fe₃O₄, which would result in the attachment of the primary amine groups to the particle surface. After that, the attachment of primary amine group was reacted with glutaraldehyde (Glu) to immobilize PGA; the products related to each step were confirmed by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibration sample magnetometer (VSM), and scanning electron microscope-energy spectroscopy of dispersive x-rays (SEM-EDS). Condition investigation results revealed that the suitable pH value, reaction time, and immobilization temperature were 8.0, 6 h, and 40 °C, respectively, under optimal conditions. Enzyme loading capacity (ELC), enzyme activity (EA), and enzyme activity retention ratio (EAR) of PGA were 9198 U, 14602 U/g, and 87.7% respectively. Reusability findings showed that the immobilization PGA preserved 79% of its activity after 11 cycles of repeating.

Keywords: Penicillin G acylase, immobilization, nano-magnetic composite, activity, reusability

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