Anaerobic biotransformation of estrogens
Anaerobic biotransformation of estrogens
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DOI：
10.1016/j.scitotenv.2006.01.021
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发表时间：
2006-08-31
影响因子：
9.8
通讯作者：
Londry, Kathleen L.
中科院分区：
文献类型：
--
作者：
Czajka, Cynthia P.;Londry, Kathleen L.
雌激素是重要的环境污染物，干扰内分泌系统和雌性化雄性鱼类。我们研究了雌激素17-α-乙炔基雌二醇（EE 2）和17-β-雌二醇（E2）的厌氧生物降解潜力，以了解它们在水生和陆地环境中的命运。使用湖水和沉积物在产甲烷、硫酸盐、铁和硝酸盐还原条件下建立培养物。在多项试验中，经过长时间的培养（三年以上），没有观察到EE 2（以5 mg/L的浓度添加）的厌氧降解。E2（以5 mg/L添加）在所有四种厌氧条件下（99-176 μ g L-1第1天）转化为雌酮（E1），但每种电子受体的转化程度不同。E1不抑制E2氧化为E1。在某些条件下，E2和E1的可逆相互转换被观察到，和E2的最终稳态浓度依赖于电子接受条件，但是独立的雌激素的总量添加。此外，发生外消旋，E1也转化为17-α-雌二醇下，但硝酸盐还原条件。虽然E2在厌氧条件下可以容易地转化为E1，并且在许多情况下转化为17-α-雌二醇，但在这些条件下雌激素的完全降解是最小的，这表明它们会在缺氧环境中积累。(c)2006 Elsevier B. V.保留所有权利。
Estrogens are important environmental contaminants that disrupt endocrine systems and feminize male fish. We investigated the potential for anaerobic biodegradation of the estrogens 17-alpha-ethynylestradiol (EE2) and 17-beta-estradiol (E2) in order to understand their fate in aquatic and terrestrial environments. Cultures were established using lake water and sediment under methanogenic, sulfate-, iron-, and nitrate-reducing conditions. Anaerobic degradation of EE2 (added at 5 mg/L) was not observed in multiple trials over long incubation periods (over three years). E2 (added at 5 mg/L) was transformed to estrone (El) under all four anaerobic conditions (99-176 mu g L-1 day 1), but the extent of conversion was different for each electron acceptor. The oxidation of E2 to E 1 was not inhibited by E1. Under some conditions, reversible inter-conversion of E2 and E1 was observed, and the final steady state concentration of E2 depended on the electron-accepting condition but was independent of the total amount of estrogens added. In addition, racemization occurred and E1 was also transformed to 17-alpha-estradiol under all but nitrate-reducing conditions. Although E2 could be readily transformed to El and in many cases 17-alpha-estradiol under anaerobic conditions, the complete degradation of estrogens under these conditions was minimal, suggesting that they would accumulate in anoxic environments. (c) 2006 Elsevier B.V. All rights reserved.