Immobilization of laccase on modified Fe3O4@SiO2@Kit-6 magnetite nanoparticles for enhanced delignification of olive pomace bio-waste

Abstract Lignocellulose is considered a major source for the production of valuable chemicals. Efficient degradation of lignin as the natural carrier of the lignocellulosic biomass represents a key limiting factor in biomass digestibility. Recently, biological delignification methods have been promoted as sustainable and environmentally friendly alternatives to the traditional technologies. In this study, porous nanocomposite of Fe 3 O 4 @SiO 2 @KIT-6 with magnetic properties was synthesized. The immobilized laccase supported on nanocomposite with enhanced stability in a hydrophobic ionic liquid has been developed for both olive pomace delignification and degradation of phenolic extracts from the pomace. After 6 h incubation, the degradation rate of lignin and phenol by the immobilized laccase was estimated to be 77.3% and 76.5%, respectively. The immobilized laccase retained 70% of its initial degradation ability after 11 successive batch treatments of olive pomace. Furthermore, the immobilized laccase retained >70% of its initial activity after 21 days of storage at room temperature. The obtained results indicated that the immobilized laccase on magnetic mesoporous support together with (1-Butyl-3-methylimidazolium hexafluorophosphate) ([Bmim][PF 6 ]) could potentially provide a promising procedure for an improved enzymatic degradation of lignin and phenol in the related industries.