Enhancing purification of α-amylase by superparamagnetic complex with alginate/chitosan/β-cyclodextrin/TPP

The main aim of this study was to synthesize the superparamagnetic nanoparticles coated by alginate/chitosan/beta-cyclodextrin to purify alpha-amylase. Isolated bacteria were identified by morphological, biochemical and taxonomic molecular studies. FTIR- spectrometer, VSM, X-ray instruments and Malvern Zetasizer were used to characterize nanoparticles characteristics. The morphological structures and the elemental composition of the nanoparticles were studied by using FESEM and EDS, respectively. The molecular weight of enzyme was determined using SDS-PAGE, and the enzyme activity detected by zymographic analysis. FTIR studies showed the presence of Fe-O-Fe in the Fe3O4 and verified the interaction between chitosan, beta-cyclodextrin and alginate. The saturation magnetization for superparamagnetic and coated superparamagnetic nanoparticles was indicated 39 and 1.9 emu g(-1), respectively. The maximum intensity of the XRD peak indicated the presence of the Fe3O4. FESEM and EDS analysis showed that the nanoparticles were regular and spherical in shape and corresponded to the Fe and O elements. Enzyme purification by synthesized nanoparticles was achieved 13.84 U mg(-1); purification fold of 3.50. The molecular weight of alpha-amylase was about 22 kDa. The highest activity of alpha-amylase was observed at 70 degrees C, pH 9.3 and Ca2+-independent. As a conclusion, the coated superparamagnetic nanoparticles showed more applications in enzyme purification comparing to the conventional methods.