Fabrication of Magnetic Nano Enzyme Fe3O4-CS-Lipase and Testing its Catalytic Activity for Triglyceride Tranesterification Reaction with Methanol in Biodiesel Production

Nguyen Vuong Hoai Thu, Hoang Ngoc Anh Nhan, Nguyen Ba Trung

Abstract: This work demonstrates herein a method to fabricate Fe3O4-CS-lipase NPs for triglyceride transesterification reaction and test its catalytic activity via reaction of soybean oil with methanol. The magnetic portion Fe3O4NP was synthesized from the mixture of Fe2+ and Fe3+ in alkaline medium using co-precipitation method, which was later coated with chitosan and then functionalized with glutaraldehyde as a cross-linking agent for lipase immobilization. Physical characterization by Fourier transform infrared spectroscopy (FT-IR), magnetic saturation, X-ray powder diffraction (XRD) showed that lipase was successfully immobilized on Fe3O4-CS NPs and the immobilized enzyme Fe3O4-CS-lipase NPs still showed good magnetic performance with a magnetic saturation value of 34.2 emu.g-1. Transmission electron microscopy (TEM) image a revealed spherical shape of Fe3O4-CS-lipase NPs with size in the range of 17 ? 28 nm. Using the immobilized lipase based catalyst, the conversion of soybean oil to fatty acid methyl esters was successfully performed under the reaction temperature of 45oC, reaction duration of 36 hours, molar ratio of methanol: oil of 3:1, and n-hexane as a co-solvent.

Keywords: Magnetic nanoparticles, immobilized lipase, enzymatic transesterification, biodiesel, fatty acid methyl esters