Efficient removal of endocrine disrupting compounds 17 α-ethynyl estradiol and 17 β-estradiol by Enterobacter sp. strain BHUBP7 and elucidation of the degradation pathway by HRAMS analysis

Owing to the increased population and their overuse, estrogens are being detected in the environment at alarming levels. They act as endocrine disrupting compounds (EDC's) posing adverse effects on animals and humans. In this study, a strain belonging to Enterobacter sp. strain BHUBP7 was recovered from a Sewage Treatment Plant (STP) situated in Varanasi city, U.P., India, and was capable of metabolizing both 17 α-Ethynylestradiol (EE2) and 17 β-Estradiol (E2) separately as a sole carbon source. The strain BHUBP7 exhibited high rates of E2 degradation as compared to EE2 degradation. The degradation of E2 (10 mg/L) was 94.3% after four days of incubation, whereas the degradation of EE2 (10 mg/L) under similar conditions was 98% after seven days of incubation. The kinetics of EE2 and E2 degradation fitted well with the first-order reaction rate. FTIR analysis revealed the involvement of functional groups like C = O, C-C, C-OH during the degradation process. The metabolites generated during degradation of EE2 and E2 were identified using HRAMS and a plausible pathway was elucidated. It was observed that metabolism of both E2 and EE2 proceeded with the formation of estrone, which was then hydroxylated to 4-hydroxy estrone, followed by ring opening at the C4-C5 position, and was further metabolized by the 4,5 seco pathway leading to the formation of 3-(7a-methyl-1,5-dioxooctahydro-1H-inden-4-yl) propanoic acid (HIP). It is the first report on the complete pathway of EE2 and E2 degradation in Enterobacter sp. strain BHUBP7. Moreover, the formation of Reactive Oxygen Species (ROS) during the degradation of EE2 and E2 was observed. It was concluded that both hormones elicited the generation of oxidative stress in the bacterium during the degradation process.

Biodegradation of 17 β-estradiol by Serratia marcescens and Stenotrophomonas tumulicola co-culture isolated from a sewage treatment plant in Upper Egypt

Background and Objectives

17 β-estradiol (E2) is an important pollutant of the aquatic system. It is responsible for sexual disruptions in the majority of aquatic organisms. This study aimed to search for bacteria with high potential degradation of E2 as an important method for bioremediation.

Materials and Methods

Sewage water samples were collected and treated to isolate bacterial strains which were identified by conventional methods and 16S ribosomal RNA gene sequence analysis. The biodegradation of E2 by the isolated strains was evaluated under different environmental conditions.

Results

Two bacterial strains were recovered from sewage water samples and identified as Stenotrophomonas tumulicola and Serratia marcescens, (named ASc2 and ASc5 respectively). Co-culture of the two strains showed biodegradation of approximately 93.6 % of E2 (50 mg. L^-1) within 48 hours. However, the biodegradation capacity of the same E2 concentration was 69.4% and 71.2% for ASc2 and ASc5 each alone, respectively. The optimum cultivation conditions for efficient E2 biodegradation by co-culture were 5% (v/v) inoculation volume with 50 mg. L^-1 of E2 as the initial concentration at pH 7 and 30°C within 48 hours inoculation period.

Conclusion

This study detected new bacterial strains that are capable of rapid degradation of estrogen as an environmental pollutant.

Highly Sensitive Detection of Hormone Estradiol E2 Using Surface-Enhanced Raman Scattering Based Immunoassays for the Clinical Diagnosis of Precocious Puberty

The hormone estradiol (17β-estradiol, E2) plays an important role in sexual development and serves as an important diagnostic biomarker of various clinical conditions. Particularly, the serum E2 concentration is very low (<10 pg/mL) in prepubertal girls. Accordingly, many efforts to develop a sensitive method of detection and quantification of E2 in human serum have been made. Nonetheless, current clinical detection methods are insufficient for accurate assessment of E2 at low concentrations (<10 pg/mL). Thus, there is an urgent need for new technologies with efficient and sensitive detection of E2 for use in routine clinical diagnostics. In this study, we introduce a new E2 assay technique using a surface-enhanced Raman scattering (SERS)-based detection method. The SERS-based assay was performed with 30 blood samples to assess its clinical feasibility, and the results were compared with data obtained using the ARCHITECT chemiluminescence immunoassay. Whereas the commercial assay system was unable to quantify serum levels of E2 lower than 10 pg/mL, the limit of detection of E2 using the novel SERS-based assay described in this study was 0.65 pg/mL. Thus, the proposed SERS-based assay has a strong potential to be a valuable tool in the early diagnosis of precocious puberty due to its excellent analytical sensitivity.