Magnetic Nanoparticles Functionalized And Modified With Cross-Linking To Improve The Invertase Immobilization

G. ROMANELLI; J. MARTINEZ; A. VARGAS

Ciencia en Desarrollo

UPTC

Año: 2021 vol. 12 p. 61 - 67

0121-7488

Procedures of immobilization invertase have been developed using different supports. However, disadvantages such as use of smallparticles for invertase immobilizations in packed-bed reactors are being solved using magnetic particles. In this study, compositescontaining Fe3O4 were prepared by incorporation of a polysiloxane layer required for the physical adsorption of the invertase.Besides, the functionalized magnetite was activated with glutaraldehyde and polyethylenimine (PEI) with the aim of performinga covalent immobilization. The effect of different conditions such as enzyme: support ratio, pH, and temperature were analyzedin the preservation of invertase. The results demonstrated that the optimum enzyme:support ratio is higher for covalent bondingthan for physical adsorption. The ideal pH for the immobilized enzyme is 5.0, and the enzymatic activity is retained until 70 ◦C.The values of km are similar in both immobilization methods. The analysis of the effect of pH and thermostability showed thatthe catalytic activity of invertase is not affected in comparison with the free enzyme. The covalent immobilization displays higherefficiency in the immobilization process (Fε), less inhibition and twice as much stability. The enzymes immobilized by physicaland covalent methods can be reused for up to four cycles and can be removed from the reaction medium by applying an externalmagnetic field.Keywords: invertase, Fe3O4, immobilization, composites