Superparamagnetic iron oxide nanoparticles (SPIONs) conjugated with lipase Candida antarctica A for biodiesel synthesis

Abstract

Biodiesel is an alternative biodegradable and non-toxic fuel, with a low emission profile and capable of reducing significantly the level of carcinogenic pollutants released into the atmosphere. A newly designed nano-biocatalyst prepared by conjugation of lipase A on superparamagnetic iron oxide nanoparticles (SPIONs) demonstrated high efficiency for production of biodiesel by the reaction of soybean oil with anhydrous methanol. The nanomaterial was characterized by FTIR, TGA and XRD, and its enzymatic activity compared with Lipozyme 435, a commercial gold standard from Novozyme™, which presented average enzymatic activity of 4559 ± 75 only twice as large as that of the SPION-CAL-A catalyst (2283 ± 249 PLU g⁻¹), whereas Lipozyme TLIM showed a much lower activity of 588 ± 16 PLU g⁻¹. These results were confirmed in the transesterification reaction for production of biodiesel where a yield of 11.4% was achieved with Lipozyme 435 and 4.6 ± 0.5% with the nano-biocatalyst. Such an improved performance associated with easy magnetic recovery and reuse make the material potentially interesting for production of biodiesel from used cooking oil, adding value to this abundant resource.