Occurrence of endocrine disrupting compounds in aqueous environment and their bacterial degradation: A review

Endocrine-disrupting compounds (EDCs), represented by steroidal estrogens (estrone (E1), 17β-estradiol (E2), estradiol (E3), and 17α-ethinylestradiol (EE2) and xenoestrogens (bisphenol A (BPA) and nonylphenol (NP)), are pollutants with estrogenic activity at very low concentrations and are emerging as a major concern for water quality. They enter into aqueous environment mainly through discharge of wastewater treatment plant (WWTP) effluents. The paper completely reviews recent studies on the occurrence of the six categories of EDCs in different aqueous environment, namely surface water, groundwater, drinking water, and wastewater in WWTPs all over the world. Furthermore, due to the high bioactivity, ubiquitous distribution, potential ecological effects, and persistence of the six categories of EDCs, the work summarizes current knowledge of their bacterial biodegradation, which is considered to be an efficient and promising method of removing EDCs. A wide range of bacteria isolated from various environments and affiliated to all kinds of genera with different degradation powers for EDCs are collected in this review in order to select specific strains adapting well to local conditions for bioremediation of freshwater, seawater, soil, sediment with low or high levels of EDCs. Finally, it emphasizes the need for further research and summarizes the future tasks that emerge from the data gathered here.