Degradation of 17α-ethynylestradiol by isolated cultures from activated sludge in wastewater treatment plants

In the present study, two different cultures (mixed and purified) were isolated from the activated sludge of the wastewater treatment plant of an oral contraceptives producing factory. The cultures were identified with the ability of 17α-ethynylestradiol (EE2, a steroidal estrogen capable of inducing biological effects at the environmentally relevant concentrations) degradation as sole source of carbon and energy. The mixed culture (containing two bacterial strains) metabolized 82-100% of the substrate added (0-4 mg l-1) within 4 d at 30°C, while the pure culture (containing the strain with comparable degradation activity) metabolized the substrate almost completely at all initial concentrations. Clear increase in the biomass concentration was also observed at both cultures.