Kinetic study on the cometabolic degradation of 17-estradiol and 17-ethinylestradiol by an Acinetobacter sp strain isolated from activated sludge

摘要

A bacterial strain has been isolated from activated sludge and was demonstrated to be capable of cometabolic biodegradation of 17-estradiol (E2) and 17-ethinylestradiol (EE2). Strain LY1, identified as Acinetobacter, can use E2 as the sole carbon source, while was unable to grow on EE2. However, with E2 (1-60mg/L) as the growth substrate, the strain was capable of cometabolizing EE2 (1-20mg/L) under the concentration ratio of EE2/E2 varying from 0.25 to 5.00. It was observed that the EE2 removal efficiency increased with the increasing excess of E2, whereas the E2 removal efficiency decreased with the increasing amounts of EE2. The kinetic model of cometabolic biodegradation of E2 and EE2 was proposed on the basis of our previous studies for the first time, considering the substrate interaction occurring, and satisfactorily predicted the cometabolic degradation progress with correlation coefficient (R-2) larger than 0.90 in batches.