A Multi-Component Reaction for Covalent Immobilization of Lipases on Amine-Functionalized Magnetic Nanoparticles: Production of Biodiesel from Waste Cooking Oil

Abstract A new approach was used for the immobilization of Thermomyces lanuginosa lipase (TLL), Candida antarctica lipase B (CALB) and Rhizomucor miehei lipase (RML) on amine-functionalized magnetic nanoparticles (Fe3O4@SiO2-NH2) via a multi-component reaction route (using cyclohexyl isocyanide). The used method offered a single-step and very fast process for covalent attachment of the lipases under extremely mild reaction conditions (25°C, water pH 7.0). Rapid and simple immoblization of 20 mg of RML, TLL and CALB on 1g of the support after 2h of incubation produced 100%, 98.5% and 99.2% immobilization yields, respectively. Thermal and co-solvent stability of the derivatives showed. The immobilized derivatives were then used for biodiesel production from waste cooking oil. Response Surface Methodology (RSM) in combination with central composite rotatable design (CCRD) was employed to evaluate and optimize the biodiesel production. The effect of some parameters such as catalyst amount, reaction temperature, amount of methanol, water content for TLL or water adsorbent for RML and CALB and ratio of t-butanol (wt%) was investigated on the fatty acid methyl esters (FAME) yield. For immobilized RML, TLL and CALB the maximum FAME yield was 74%, 81% and 78% respectively.