A simple

effective

green and economic approach of lipase immobilization is provided in this article.Single-crystal

hydrophilic

biocompatible Fe3O4magnetic nanoparticles as good carriers were prepared via a solvothermal reduction method.Microsphere diameters were observed to be about 200 nm by transmission electron microscopy (TEM).Superior monodispersity was demonstrated

and saturation magnetization was found to be 83.7 emug-1.The resulting products were modified directly with -aminopropyltriethoxysilane (APTS).Porcine pancreas lipase (PPL) was covalently immobilized on the obtained particles using glutaraldehyde as a coupling reagent.The enzymatic activities of free and immobilized PPL were measured by titration of fatty acid which came from the hydrolysis of olive oil and the amount of protein was determined by the Bradford method using bovine serum albumin (BSA) as a standard.The factors related with the activity of the immobilized lipase on prior carriers

such as the pH value of the immobilized reaction

the concentration of glutaraldehyde and the amount of enzyme were investigated.The immobilized lipase exhibited excellent thermal stability and reusability in comparison with free enzyme.High activity recovery (54.8%) of the immobilized lipase was achieved and the amount of protein was up to 120 mg/g.This immobilized lipase can be reused 10 times with the enzymatic activity remained above 90%.