Integrate spectroscopic kinetic evaluation of Malachite Green and Crystal Violet biodegradation by Providencia stuartii

The discharge of dye-laden textile effluents poses a significant environmental challenge due to the persistence and toxicity of synthetic dyes such as Malachite Green (MG) and Crystal Violet (CV). This study aimed to isolate and evaluate efficient dye-degrading bacteria from contaminated textile effluents. Among eight isolates, Providencia stuartii DDB-02 exhibited the highest degradation efficiency, achieving 100% decolourization of both MG and CV within 72 h. UV–Vis with rapid degradation of MG (92% within 24 h), reduction in absorbance peaks at 618 nm (MG) and 590 nm (CV), and FTIR analyses indicated structural changes in dye molecules, suggesting biodegradation. The strain shows promising potential for wastewater treatment applications. However, further studies involving metabolite identification and large-scale validation are required to confirm its industrial applicability. • First report of Providencia stuartii exhibiting dual degradation of Malachite Green and Crystal Violet. • Achieved 100% degradation of both dyes within 72 h under unoptimized conditions. • Strain demonstrates strong biofilm formation and oxidoreductive enzyme activity. • Includes environmental risk assessment and proposed mechanistic pathway. • Potential application in sustainable textile wastewater treatment