Immobilization of <i>Pleurotus eryngii</i> Laccase via a Protein–Inorganic Hybrid for Efficient Degradation of Bisphenol A as a Potent Xenobiotic

• Published in: Journal of Xenobiotics
• Main Authors: Sanjay K. S. Patel, Rahul K. Gupta, Jung-Kul Lee
• Format: Article
• Language: English
• Published: MDPI AG 2025-07-01
• Subjects: <i>Pleurotus eryngii</i> laccase; biocatalysts; bisphenol A; immobilization; inorganic–protein hybrids; xenobiotics
• Online Access: https://www.mdpi.com/2039-4713/15/4/108
• ISSN: 2039-4705; 2039-4713

In the present investigation, an eco-friendly biocatalyst was developed using <i>Pleurotus eryngii</i> laccase (<i>Pe</i>Lac) through a copper (Cu)-based protein–inorganic hybrid system for the degradation of bisphenol A, a representative xenobiotic. After partial purification, the specific activity of crude <i>Pe</i>Lac was 92.6 U/mg of total protein. Immobilization of <i>Pe</i>Lac as Cu₃(PO₄)₂–Lac (Cu–<i>Pe</i>Lac) nanoflowers (NFs) at 4 °C resulted in a relative activity 333% higher than that of the free enzyme. The Cu–<i>Pe</i>Lac NFs exhibited greater pH and temperature stability and enhanced catalytic activity compared to free laccase. This enhanced activity was validated through improved electrochemical properties. After immobilization, Cu–<i>Pe</i>Lac NFs retained up to 8.7-fold higher residual activity after storage at 4 °C for 30 days. Free and immobilized laccase degraded bisphenol A by 41.6% and 99.8%, respectively, after 2 h of incubation at 30 °C. After ten cycles, Cu–<i>Pe</i>Lac NFs retained 91.2% degradation efficiency. In the presence of potent laccase inhibitors, Cu–<i>Pe</i>Lac NFs exhibited a 47.3-fold improvement in bisphenol A degradation compared to free <i>Pe</i>Lac. Additionally, the synthesized Cu–<i>Pe</i>Lac NFs demonstrated lower acute toxicity against <i>Vibrio fischeri</i> than Cu nanoparticles. This study presents the first report of <i>Pe</i>Lac immobilization through an eco-friendly protein–inorganic hybrid system, with promising potential for degrading bisphenol A in the presence of inhibitors to support sustainable development.