Polymer-assisted iron oxide magnetic nanoparticle immobilized keratinase

Abstract

Nanotechnology holds the prospect for avant-garde changes to improve the performance ofmaterials in various sectors. The domain of enzyme biotechnology is no exception.Immobilization of industrially important enzymes onto nanomaterials, with improvedperformance, would pave the way to myriad application-based commercialization. Keratinaseproduced by Bacillus subtilis was immobilized onto poly(ethylene glycol)-supportedFe3O4 superparamagnetic nanoparticles. The optimization process showed that the highest enzyme activitywas noted when immobilized onto cyanamide-activated PEG-assisted MNP prepared under conditionsof 25 °C and pH 7.2 of the reaction mixture before addition ofH2O2 (3% w/w),2% (w/v)PEG6000 and 0.062:1 molarratio of PEG to FeCl2·4H2O. Further statistical optimization using response surface methodology yielded anR2 value that could explain more than 94% of the sample variations. Along with themagnetization studies, the immobilization of the enzyme onto the PEG-assisted MNP wascharacterized by UV, XRD, FTIR and TEM. The immobilization process had resulted inan almost fourfold increase in the enzyme activity over the free enzyme. Furthermore, theimmobilized enzyme exhibited a significant thermostability, storage stability andrecyclability. The leather-industry-oriented application of the immobilized enzyme wastested for the dehairing of goat-skin.