The impact of endocrine-disrupting chemicals on the environment and their potential biotransformation by white-rot fungi and their oxidative enzymes.

Taboada-Puig, Roberto Moreira, Maria-Teresa Agathos, Spiros N. [UCL] Lema, Juan M.

e search of new technologies suitable for the treatment of wastewater containing endocrine disrupting chemicals (EDCs) such as bisphenol A (BPA), triclosan (TCS), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) is a challenge since existing traditional wastewater treatment plants (WWTPs) are not able to eliminate them completely. Even at concentrations of ng/L, EDCs have an impact in the endocrine system of the fauna producing morphological deformities, reduced overall growth, reduced sperm quality and delayed ovulation, sex reversal male to female, among others. Efforts have been put in the study of different post-treatments to remove the residual concentration of EDCs present in WWTP effluents. The most frequently used technologies are advanced oxidation processes (AOPs) such as photocatalysis, photodegradation, sonolysis, ozonolysis, amongst others. In general, these processes have high degradation rate but they have low selectivity and high costs. In addition, AOPs can be a cause of concern itself since they may render harmful by-products or transformation products which can have similar or increased estrogenicity of that of the parent compound. A biological alternative may be use of white-rot fungi (WRF) or their lignin modifying enzymes (LMEs) to treat wastewater containing EDCs. From an operational point of view, the use of LMEs in in vitro systems, compared to the use of WRF in in vivo systems, is easier and cheaper since no aseptic conditions are needed. Among the LMEs, laccase is the most extensively studied enzyme for the degradation of BPA, TCS, E1, E2 and EE2 whereas peroxidases (LiP, MnP and VP) have not been studied in such level of detail.