Trametes cingulata: A white rot fungus in decolorization of azo dye reactive red 239

Abstract

Background

Azo dyes in textile effluents represent a particular health concern because they include azo groups (NN), which are reactive with DNA nucleic acids. The enzymes produced by white rot fungi can biodegrade a broad range of environmental contaminants. This work addresses this by concentrating on novel and effective optimal conditions for Trametes cingulata to produce oxidative enzymes and the capacity to decolorize the azo dye reactive red 239.

Results

A multifactorial experimental design optimized enzymatic activity and azo dye decolorization. Concentrations of 2.5 g L⁻¹ of copper sulfate (CS) and 3.0 g L⁻¹ of yeast extract (YS) for 16 days produced 100% decolorization, with 7.72 U mL⁻¹ of laccase (Lac) and 0.013 U mL⁻¹ of lignin peroxidase (Lip). These were found to be the ideal conditions for the decolorization process. The maximal Lac activity was 12.22 U mL⁻¹ with 2.5 g L⁻¹ CS, 25.0 g L⁻¹ YS and 16 days, in addition to 0.14 U mL⁻¹ Lip activity and 59% decolorization. It was possible to ascertain that the dye's functional groups had been adsorbed to the fungal mycelium by employing Fourier transform infrared spectroscopy. Images obtained from scanning electron microscopy analyses enable the distinction of certain features that signify the adsorption process. Additionally, under ideal decolorization conditions, a 55% chemical oxygen demand decrease was noted.

Conclusion

The findings reported show that T. cingulata may decolorize effluents containing azo dyes using two distinct processes: fungal mycelium biosorption and enzymatic degradation. © 2025 Society of Chemical Industry (SCI).