Decolourisation of textile dye by laccase: Process evaluation and assessment of its degradation bioproducts.

Biodegradation of environmentally hazardous synthetic dyes by enzymes has been achieved the highest interest in recent years. In this work, we optimized Remazol Brilliant Blue R (RBBR) dye biodegradation by Arthrographis kalrae derived laccase via the Box-Behnken design (BBD) approach of the surface response methodology (RSM). Optimization of dye decolourisation by one variable at a time (OVAT) approach resulted in optimal dye decolourisation at laccase dose (2 IU mL-1), pH (7.0), temperature (35 °C), incubation time (240 min), and initial dye concentration (100 mg L-1). The optimized process through BBD enhanced dye decolourisation (97.18%). Fourier Transform Infrared Spectroscopy and UV-Visible Spectrophotometry have proven biodegradation. In addition, in comparison to untreated samples, the laccase-treated dye sample showed relatively less phyto- and cytotoxic effect on Allium cepa L. Extra Precision Glide docking exhibited the binding affinity score of -5.355 kcal mol-1, between laccase-RBBR complex.