Wax esters from waste fish oil catalysed by immobilized Candida rugosa lipase

Herein, the evaluation of waste fish (WF) oils as feedstock for the production of wax esters through transesterification reactions was reported. In particular, the synthesis of an emollient ester in the presence of oleyl alcohol and using an immobilized lipase catalyst was proposed. Lipase from Candida rugosa (CRL) was immobilized (0.5 enzyme/support wt. ratio) on a magnetic amino-functionalized hypercross-linked resin (M-HCLR-NH2) by ion exchange, interfacial activation, and covalent anchoring, mediated by 1-ethyl-3-(3-dimethyl-aminopropyl)carbodiimide (EDC). The experimental results demonstrated the successful immobilization of lipase on the as-produced M-HCLR-NH2 with a high immobilization yield of 90%. The immobilized CRL showed very high activity and an activity recovery of ∼ 94%. The immobilized enzyme on the magnetic resin results in more stability and less sensitivity to temperature change than the free counterpart. In addition, during emollient ester synthesis in a solvent system, the immobilized enzyme exhibited very high activity, stability, and excellent reusability, with a yield of 94% after 12 h at 45 °C at an oil:alcohol molar ratio of 1:4 and an immobilized enzyme concentration of 15 wt%./wt of oil. Esters synthesized showed excellent physicochemical properties.