Basic study on lipase-immobilized magnetic nanoparticles

Abstract

Herein, the magnetic nanoparticles (MNPs) were produced by the solgel technique. This magnetic carrier was characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy and X-ray diffraction. The size of the MNPs was determined to be 10.33 nm from the diffraction patterns, and also, least agglomeration was observed in TEM. The presence of required peaks in FT-IR confirmed MNPs formation, and their significant shifts confirmed the lipase binding. Then, lipase was immobilized onto MNPs by covalent attachment following surface modification and activation. The study reported maximum immobilization percentage as 92.3% which reduced on successive lipase loadings. Excellent thermostability and reusability were exhibited by the lipase-bound MNPs in the activity assay. At optimum pH (7.5), relative activity of the immobilized lipase showed no notable change, whereas, at higher temperature, it was higher than that of free lipase. This can be inferred that good thermal resistance was provided by the MNPs to lipase from unconditional disturbances. Increased Vmax showed the negligible steric hindrance in the active sites of immobilized lipase. At the eighth cycle of the process, it was observed that enzyme attained half of its maximum activity. Hence, this magnetite carrier may be considered as the best choice for immobilization of industrially important enzyme such as lipase and their efficient application.