Triazine-functionalized chitosan-encapsulated superparamagnetic nanoparticles as reusable and robust nanocarrier for glucoamylase immobilization

Abstract

Aspergillus niger glucoamylase (GLA) was covalently immobilized on 1,3,5-triazine-functionalized chitosan coated superparamagnetic nanoparticles (MNPCh-CC). The morphology, structure and properties of functionalized nanocomposite were investigated, as well as GLA immobilization process, through different analytical tools. Different experimental parameters such as optimum temperature, pH, reaction time and enzyme concentration were studied for free and immobilized enzyme. The GLA immobilized on nanocarrier exhibited excellent catalytic activity at pH 4.5 and 60 °C. Notably, the immobilized GLA showed quite impressive stability, even after 10 reaction cycles, it could still retain about 70% of the initial activity. The results showed that immobilization process couldn't significantly inhibit enzyme-substrate interaction and subsequently retained its effective catalytic activity. The substantial improvement of reactivity, reusability, and stability of this biocatalyst system may confer it a wider range of applications in industrial processes. © 2017 Elsevier B.V.