Chitosan-coated Lentinus polychrous Lév.: Integrated biosorption and biodegradation systems for decolorization of anionic reactive dyes

• Development of effective anionic reactive dye removal systems.
• Integration of biosorption capacity of chitosan and biodegradation ability of fungi.
• Effects of chitosan coating on decolorization performance of Lentinus polychrous Lév.
• Dominant biosorption in case of high chitosan concentration.
• Dominant biodegradation by ligninolytic enzymes in case of uncoated fungi.

Research and development of an effective color removal system is needed to reduce the severity of water pollution caused by effluent that contains dyes. In this study, the integrated biosorption and biodegradation system of chitosan coated Lentinus polychrous Lév. was developed and evaluated for its decolorization efficiency with regard to anionic reactive dye mixtures of Reactive Blue 19, 160, and 198. The fungi were coated with 0.1, 0.5, and 1.0% w/v of low molecular weight chitosan. The scanning electron micrographs confirmed that chitosan was successfully coated on the surface of the fungi. Studies of changes in UV–visible absorption spectra, dye desorption, ligninolytic enzyme activity, and Fourier transform infrared spectroscopy showed that within 6 h, the biosorption was the control mechanism and the dyes were reduced to 91.50, 77.66, 37.39, and 26.93% by the fungi coated with 0, 0.1, 0.5, and 1.0% w/v chitosan, respectively. From the 36th hour to the end of colorization at the 72nd hour, the fungal biodegradation by laccase and manganese peroxidase was dominant and all treatments had 5–8% of the dye remaining. Therefore, the chitosan coat acted as an efficient biosorbent for the anionic reactive dyes, thereby effectively improving the decolorization efficiency of the white rot fungus.