A 17β-estradiol (E2)-degrading bacterium E2S was isolated from the activated sludge in a sewage treatment plant (STP). The morphology, biological characteristics, and 16S ribosomal RNA (rRNA) gene sequence of strain E2S indicated that it belonged to the genus Novosphingobium. The optimal degrading conditions were 30 °C and pH 7.0. The ideal inoculum volume was 5% (v/v), and a 20-mL degradation system was sufficient to support the removal ability of strain E2S. The addition of extra NaCl to the system did not benefit the E2 degradation in batch culture by this strain. Strain E2S exhibited high degradation efficiency with initial substrate concentrations of 10–50 mg·L−1. For example, in mineral salt medium containing 50 mg·L−1 of E2, the degradation efficiency was 63.29% after seven days. In cow manure samples supplemented with 50 mg·L−1 of E2, strain E2S exhibited 66.40% degradation efficiency after seven days. The finding of the E2-degrading strain E2S provided a promising method for removing E2 from livestock manure in order to reduce the potential environmental risks of E2.

The presence of estrogens in livestock excrement has raised concerns about their potential negative influence on animals and the overall food cycle. This is the first investigation to simultaneously remove estrogens, including estriol (E3), bisphenol A (BPA), diethylstilbestrol (DES), estradiol (E2), and ethinyl estradiol (EE2), from cow manure using a Fenton oxidation technique. Based on the residual concentrations and removal efficiency of estrogens, the Fenton oxidation reaction conditions were optimized as follows: a H2O2 dosage of 2.56 mmol/g, a Fe(II) to H2O2 molar ratio of 0.125 M/M, a solid to water mass ratio of 2 g/mL, an initial pH of 3, and a reaction time of 24 h. Under these conditions, the simultaneous removal efficiencies of E3, BPA, DES, E2, and EE2, with initial concentrations in cow manure of 97.40, 96.54, 100.22, 95.01, and 72.49 mg/kg, were 84.9%, 99.5%, 99.1%, 97.8%, and 84.5%, respectively. We clarified the possible Fenton oxidation reaction mechanisms that governed the degradation of estrogens. We concluded that Fenton oxidation technique could be effective for efficient removal of estrogens in livestock excrement. Results are of great importance for cow manure reuse in agricultural management, and can be used to reduce the threat of environmental estrogens to human health and ecological safety.

In this study we investigated the prevalence of antimicrobial resistance in clinical isolates of Gram-negative bacteria obtained from intensive care units (ICUs) in the People's Liberation Army (PLA) 309 Hospital located in beijing, China. between 2007 and 2010, a total of 1949 isolates of Gram-negative bacteria were collected and tested using an antibiotic susceptibility assay. A marked decrease was observed in the susceptibility of Acinetobacter baumannii to imipenem and amikacin as compared to that described in a previous report in China. Similar results were obtained for Pseudomonas aeruginosa. However, imipenem and amikacin showed strong activity against Escherichia coli and Klebsiella pneumoniae. Overall, the high rates of antimicrobial resistance against ICU pathogens in our hospital indicated a critical condition in Beijing, China. Development of a national control and monitoring system by the government may be an ideal method to solve the present problem of managing infections due to Gram-negative bacterial pathogens.