Improvement of stability and reusability of α-amylase immobilized on naringin functionalized magnetic nanoparticles: A robust nanobiocatalyst

Enzyme immobilized on magnetic nanoparticles (MNPs) can be used as efficient recoverable biocatalysts under strong magnetic responses. In the present work, alpha-amylase was immobilized onto naringin functionalized MNPs via ionic interactions. For this purpose, the MNPs were functionalized with naringin, as a biocompatible flavonoid. The morphology, structure, and properties of functionalized MNPs and the immobilization of alpha-amylase on synthesized nanocomposite were characterized through different analytical tools including TGA, VSM, FTIR, SEM-EDX and TEM. Furthermore, the optimum conditions of temperature, pH, reaction time and enzyme concentration for immobilization process were investigated. The results showed that the optimal conditions for immobilization of alpha-amylase onto synthesized nanocarrier occurred at pH 6.5 and 55 degrees C. The reusability experiments revealed high activity maintenance of immobilized alpha-amylase even after 10 reaction cycles. Moreover, the storage stability of immobilized enzyme improved via immobilization in comparison with free one and it maintained 60% of its initial activity after 6 weeks storage at 4 degrees C. The improvements in enzyme catalytic properties via immobilization made this nanobiocatalyst as a good candidate in bio-industrial applications. Furthermore, the synthesized nanocomposite would have the potential for practical applications in other and binary enzyme immobilization. (C) 2018 Elsevier B.V. All rights reserved.