Biodegradation and Detoxification of BPA: Involving Laccase and a Mediator

Funalia trogii was used for the first time for the removal of bisphenol A (BPA), a well known endocrine disrupting compound. Biodegradation efficiencies of commercial pure laccase from Trametes versicolor, crude extract of F. trogii and the mixture of pure laccase from T. versicolor, and thermally inactivated crude extract of F. trogii were compared. BPA was completely removed by both the crude extract and with mixture whereas only 30% was removed with pure laccase. The results showed the presence of mediator molecules in the crude extract of F. trogii and also confirm the role of laccase in BPA biodegradation. A mediator molecule, butylhydroxytoluene, was detected by GC-MS analysis of the crude extract of F. trogii. The results also proved unnecessity of enzyme isolation procedures for the enzymatic biodegradation of BPA. The BPA concentration was analyzed by HPLC and metabolites of BPA were characterized by GC-MS. The results of both analyses were correlated and BPA was completely removed after 2 h of incubation time. The reaction maximum velocity and Km values obtained from Lineweaver-Burk plots of Michaelis-Menten equation were 7.43mg L-1 min(-1) and 66.35 mg/L, respectively. The acute toxicity of BPA and its products after 6 h incubation period was 98.9 +/- 1.0 and 7.5 +/- 0.4%, respectively. The results of this study point out the use of an alternative feasible method for the complete removal of BPA from polluted environments.