Statistical Optimization of Bacillus alcalophilus α-amylase Immobilization on Iron-oxide Magnetic Nanoparticles

We report the statistical optimization of the immobilization of alkaline a-amylase [E C 3 2 1 1] from Bacillus alcalophilus onto nano-sized supermagnetic iron-oxide nanoparticles (MNPs) for augmenting the cost effective industrial application of MNP-bound a-amylase Both Plackett-Burman factorial design and response surface methodology (RSM) were employed to screen the influence of different parameters and the central effect of response on the a-amylase-iron oxide MNP binding process The high coefficient of determination (R-2) and analysis of variance (ANOVA) of the quadratic model indicated the competence of the proposed model The size of the MNPs was confirmed by X-ray diffraction and scanning electron microscope analyses in which Fourier transform infrared spectroscopy suggested immobilization of the enzyme on iron-oxide MNPs A significant improvement (similar to 26-fold) in specific activity, thermal and storage stability, and reusability of a-amylase after binding with iron-oxide MNP reinforced the improved biotechnological potential of the cc-amylase iron-oxide MNP bioconjugate compared to free a-amylase These results open new avenues for applying this MNP immobilized enzyme in different industrial sectors, notably in the paper and brewing industries