Simple fabrication of polymer-based Trametes versicolor laccase for decolorization of malachite green

A highly efficient and stable biocatalyst (denoted D201_Lac) was fabricated by encapsulating Trametes versicolor laccase within a macroporous and strongly basic exchange resin D201 through a simple adsorption process. Transmission electron micrographs and Fourier transform infrared spectra of the resultant D201_Lac proved that nanosized laccase clusters were embedded into the inner nano-pores/channels of D201. As compared to the free laccase, D201_Lac showed enhanced resistance in the pH range of 3–7 or at temperature of 30–60 °C. Besides, negligible laccase was leached out from the host polymer D201 in solution of pH 3–7 and NaCl concentration up to 0.5 M, which might be attributed to the electrostatic attraction and the possible twining between long-chain laccase and the cross-linking host resin. Continuous seven-cycle batch decoloration of malachite green demonstrates that decoloration efficiency of D201_Lac kept constant for more than 320-h operation.

► A highly efficient composite biocatalyst D201_Lac was fabricated through a simple adsorption process for dye decoloration. ► D201_Lac possesses outstanding stability and enhanced resistance against pH and temperature fluctuation. ► Negligible activity loss of the resultant D201-Lac was observed for batch continuous 320-h operation.