Song Hai L, Yang Xiao L, Xia Ming Q, Chen Ming
a School of Energy and Environment , Southeast University , Nanjing , China.
b Key Laboratory of Environmental Medicine Engineering of Ministry of Education , Southeast University , Nanjing , China.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2017 Jul 3;52(8):778-784. doi: 10.1080/10934529.2017.1305168. Epub 2017 Apr 3.
Three membrane bioreactors (MBRs) with different carbon/nitrogen ratios were operated in parallel to investigate the effects of heterotrophic bacteria and nitrifying bacteria on the co-metabolic degradation of the steroid estrogens (SEs) estrone (E1) and 17α-ethinylestradiol (EE2). The functional community structures of the MBRs were analyzed using fluorescence in situ hybridization, and correlations between the functional community structures and SE removal efficiencies were established. The results showed that α-Proteobacteria, β-Proteobacteria, and γ-proteobacteria were responsible for the removal of E1, whereas ammonia-oxidizing bacteria, Nitrosomonas sp., Nitrosospira sp., Nitrospira sp., and Nitrobacter sp. were responsible for EE2 removal. Nitrifying activated sludge degraded E1 and EE2 alone, with degradation efficiencies of 71.04 and 65.51%, respectively. Moreover, biodegradation of E1 and EE2 was reduced significantly (by 30.30 and 34.03%, respectively) when nitrification was inhibited. Heterotrophic and nitrifying bacteria were responsible for E1 and EE2 degradation, but nitrification was considered to be the key process in the enhancement of SE degradation. Organic co-metabolism by heterotrophic bacteria had a significant effect on E1 removal, and nitrification co-metabolism by nitrifying bacteria had a significant effect on EE2 removal. These results improve our understanding of the co-metabolic degradation of SEs, which is useful for improving SE removal and guaranteeing the health of aqueous environments.
运行了三个具有不同碳氮比的膜生物反应器（MBR），以平行方式研究异养细菌和硝化细菌对甾体雌激素（SEs）雌酮（E1）和17α-乙炔雌二醇（EE2）共代谢降解的影响。使用荧光原位杂交分析了MBR的功能群落结构，并建立了功能群落结构与SE去除效率之间的相关性。结果表明，α-变形菌、β-变形菌和γ-变形菌负责E1的去除，而氨氧化细菌、亚硝化单胞菌属、亚硝化螺菌属、硝化螺菌属和硝化杆菌属负责EE2的去除。硝化活性污泥单独降解E1和EE2，降解效率分别为71.04%和65.51%。此外，当硝化作用受到抑制时，E1和EE2的生物降解显著降低（分别降低30.30%和34.03%）。异养细菌和硝化细菌负责E1和EE2的降解，但硝化作用被认为是增强SE降解的关键过程。异养细菌的有机共代谢对E1的去除有显著影响，硝化细菌的硝化共代谢对EE2的去除有显著影响。这些结果增进了我们对SEs共代谢降解的理解，这对于提高SE去除率和保障水环境健康很有用。
