Ameliorating the activity and stability of beta galactosidase by tailoring potential nanobiocatalyst on functionalized nanographene: Headway to lactose hydrolysis

摘要

The ever-growing occurrence of intolerance to dairy products has led to an enormous requirement for immobilization of beta galactosidase. In this report, we have shown the immobilization of beta galactosidase onto polyaniline doped magnetic graphene (Fe3O4@PANI-GO) nanocomposite. A comparative analysis has been carried out for the integration via physical adsorption and covalent binding methods onto functionalized graphene nanocomposite for analytical application based on lactose reduction. The higher immobilization yield was exhibited in the case of the covalently bound enzyme with eta (effectiveness factor) value of 1.49. Characterization of functionalized graphene was studied by scanning and transmission electron microscope, and Fourier-transform infrared spectroscopy studies. Shift of pH optima was observed for covalently bound enzyme from pH 4.5 to 5. The immobilized beta galactosidase displayed temperature optima similar to the soluble enzyme at 50 degrees C. Covalently bound enzyme retained 80% activity even after its 10th successive reuse. The immobilized enzyme displayed higher lactose reduction from milk than the free enzyme. Our conclusions have framed the way for the establishment of graphene-based nanobiosensor to upgrade the quality of milk and its products for easy assimilation by the lactose intolerant patients.