Appraisal of malachite green biodegradation and detoxification potential of laccase from Trametes cubensis

[Display omitted] •First report on malachite green degradation by T. cubensis laccase.•Maximum laccase production by SSF was 6577.00 ± 14.32 U/g at 8 d.•89 and 86 % decolorization in 2 h by free and chitosan immobilized laccase.•Non-toxicity of malachite green degradation confirmed by toxicological studies.•Pathway for malachite green degradation by laccase deduced by GC–MS analysis. The laccase from the newly isolated Trametes cubensis was investigated for its potential to degrade malachite green (MG) dye. Optimized solid-substrate fermentation enhanced laccase production by 8.8-fold, reaching an activity of 6577.0 ± 14.3 U/g. Proteomic characterization identified enzyme with 4 % sequence coverage, molecular weight of 43.1 kDa, and alignment with multicopper oxidases. Using one-factor-at-a-time optimization, MG decolorization was maximized at 89 % under optimal conditions: 20 U/mL enzyme dose, 0.1 mg/mL dye concentration, pH 5.0, and 2 h incubation at 50 °C. Crosslinking the laccase onto chitosan beads resulted in 82 % immobilization efficiency, with high recyclability and reusability, retaining over 52 % activity after 7 cycles and demonstrating similar (p