Production and characterization of Laccase from Lentinus berteroi and applications for biodegradation of organic micropollutants.

This study aimed to produce, purify, and characterize laccase from Lentinus berteroi U21-2, for its potential application in the biodegradation of micropollutants. The fungus was cultivated in a liquid medium for 15 days at 28 °C in the dark. The enzymatic extract was purified using chromatographic techniques, and its molecular mass was determined through gel filtration, SDS-PAGE, and peptide mass fingerprint analysis. The optimum pH, temperature, and residual activity were evaluated using ABTS, guaiacol, and syringaldazine as substrates. UV-Vis spectroscopy and LC-MS/MS techniques were used to assess the laccase biodegradation of micropollutants. The laccase was 3.2-fold purified, and gel filtration estimated its molecular mass at 79.7 kDa, while SDS-PAGE revealed two bands of approximately 66 kDa and 50 kDa, being the ~50 kDa band a fragment. The purified enzyme demonstrated maximum activity at pH 4.5 and 30 °C, retaining 80% of its activity for 58 hours, and a higher affinity for syringaldazine as indicated by the K_M. The purified laccase effectively reduced the initial concentration of β-estradiol by 82%, diclofenac by 70%, and bisphenol-A by 30%, but showed no degradation of ibuprofen. These findings highlight the potential of L. berteroi laccase as a promising biocatalyst for the biodegradation of micropollutants.