Enhanced Biodiesel\nProduction with Eversa Transform\n2.0 Lipase on Magnetic Nanoparticles

This research investigated\nthe usefulness of magnetic iron oxide\nnanoparticles (Fe<sub>3</sub>O<sub>4</sub>) as a support to immobilize\nthe lipase Eversa Transform 2.0 (ET 2.0) to obtain an active and stable\nbiocatalyst, easily recoverable from the reaction medium for applications\nin the production of biodiesel. Biodiesel was an alternative fuel\ncomposed mainly of fatty acid esters with strong transesterification\nand esterification capabilities. The study focused on the esterification\nof oleic acid with ethanol to synthesize ethyl oleate. Magnetic nanoparticles\nwere prepared by coprecipitation, then activated with glutaraldehyde\nand functionalized with γ-aminopropyltriethoxysilane (APTES).\nThe optimal conditions for immobilizing ET 2.0 were pH 10, 25 mM sodium\ncarbonate buffer, an enzymatic load of 200 U/g, and 1 h of contact\ntime, obtaining 78% yield and enzymatic activity of 205.9 U/g. Postimmobilization\nevaluation showed that the immobilized enzyme performed better than\nits free form. Kinetic studies were conducted under these optimized\nconditions (2–96 h at 150 rpm and 37 °C). The biocatalyst\nwas tested for the synthesis of ethyl oleate using oleic acid as the\nsubstrate and ethanol, achieving a conversion of 88.1%. Subsequent\nrecirculation tests maintained approximately 80% conversion until\nthe fourth cycle, confirming the sustainability of ester production.\nMolecular docking studies revealed that the binding affinity for the\nenzyme-docked oil composition was estimated at −5.8 kcal/mol,\nsuggesting that the combination of the substrate and lipase was stable\nand suitable for esterification.