New efficient laccase immobilization strategy using ionic liquids for biocatalysis and microbial fuel cells applications

Abstract

AbstractBACKGROUNDLaccases belong to the family of blue multicopper oxidases, these enzymes are efficient in many applications, including in biofuel cells to produce electricity through chemical reactions. Several laccase immobilization methods have been elucidated, such as covalent link and entrapment.RESULTSThe present work describes how, for the first time, laccase was successfully immobilized by entrapment into polymer inclusion ionic liquid membranes (PILMs) based on ionic liquids and polyvinylchloride. The immobilization rate was very high in all cases (99.2 ± 0.6%), so that the enzyme entrapment strategy described can be considered as successful and one of the best methods for laccases immobilization that have been reported to date. The assayed membranes were evaluated as performing carrier for laccase by means of the ABTS oxidation. Four screened ionic liquids were used for the first time for this purpose: [OMIM][NTf2], [EMIM][NTf2], [Epy][NTf2] and [Chol][NTf2]. This work demonstrated the efficiency in terms of the activity rate and stability of the enzyme versus IL concentrations. The most suitable IL as regards activity [Chol][NTf2]. However, the reuse assays showed that the most stable PILM was the one constituted by 50% [Epy][NTf2]. For physical resistance and water insolubility, the [OMIM][NTf2] based PILM was selected for microbial fuel cell (MFC) application.CONCLUSIONThis is the first report describing this original entrapment strategy for laccase immobilization into PILM. The application of this laccase‐membrane in MFC showed high stability during almost one week of use and good efficiency in producing bio‐energy and removing COD from industrial wastewater. © 2017 Society of Chemical Industry