Kinetic Profiling and Substrate Specificity Optimization of a Novel Fungal Laccase from Trametes versicolor for Enhanced Degradation of Bisphenol A

Bisphenol A (BPA), a ubiquitous endocrine-disrupting chemical, poses significant environmental and health risks due to its widespread use and persistence. This study investigates the kinetic properties and substrate specificity optimization of a novel laccase isolated from the white-rot fungus Trametes versicolor for enhanced BPA degradation. The purified laccase exhibited optimal activity at pH 5.0 and 45°C, demonstrating a V_max of 125 U/mg and K_m of 55 µM for ABTS. For BPA, initial kinetic analysis revealed a K_m of 1.2 mM and a V_max of 0.8 U/mg. To improve BPA degradation efficiency, reaction parameters including pH, temperature, and the presence of low-molecular-weight redox mediators were systematically optimized. The addition of 1-hydroxybenzotriazole (HBT) at 0.5 mM significantly enhanced BPA degradation, achieving over 90% removal within 8 hours under optimized conditions (pH 5.5, 40°C). HPLC analysis confirmed the substantial reduction of BPA, indicating the potential of this laccase system for effective bioremediation. This research provides valuable insights into the enzymatic degradation of BPA and highlights the promising application of optimized fungal laccases in environmental biotechnology.