Olive mill waste (OMW) as raw material for bio-lubricant production by an innovative immobilized lipase

In the present paper, bio-lubricant was obtained by Olive Mill Waste (OMW) by using a novel enzyme-immobilized nanocatalyst. Indeed, OMWs, which present critical environmental problems and for which different disposal approaches have been proposed and adopted by the legislation of different countries, but failed to find a definitive solution, contain compounds with high added value such as residual oil. An "eco-friendly" approach consists of the preparation of citrate-zinc ferrite nanoparticles (ZnFe2O4 NPs), for the direct physical immobilization of Thermomyces lanuginosus lipase (TLL). Zn anion is a co-factor that can contribute with additional sites to improve enzymatic adsorption and maintain the structure and activity of the enzyme. The maximum activity recovery was 89 % +/- 2 SD at 0.1 mg/ml, with protein loading of more than 17 mg enzyme/gNPs. Moreover, the optimal reaction condition for bio-lubricant synthesis has been identified in this study. The response surface analysis predicted the optimum point for a 96.1 % yield at a temperature of 44 degrees C and a molar ratio of 4.9:1 after 24 h. This immobilization approach allows for a brilliant catalytic activity and reusability nanocatalyst to produce bio-lubricants with useful properties without deforesting or competing with food sources.