Reversible Reduction of Estrone to 17β‐Estradiol by Rhizobium, Sphingopyxis, and Pseudomonas Isolates from the Las Vegas Wash

Abstract

Environmental endocrine-disrupting compounds (EDCs) are a growing concern as studies reveal their persistence and detrimental effects on wildlife. Microorganisms are known to affect the transformation of steroid EDCs; however, the diversity of estrogen-degrading microorganisms and the range of transformations they mediate remain relatively little studied. In mesocosms, low concentrations of added estrone (E1) and 17β-estradiol (E2) were removed by indigenous microorganisms from Las Vegas Wash water within 2 wk. Three bacterial isolates, sp. strain LVW-9, sp. strain LVW-12, and sp. strain LVW-PC, were enriched from Las Vegas Wash water on E1 and E2 and used for EDC transformation studies. In the presence of alternative carbon sources, LVW-9 and LVW-12 catalyzed near-stoichiometric reduction of E1 to E2 but subsequently reoxidized E2 back to E1; whereas LVW-PC minimally reduced E1 to E2 but effectively oxidized E2 to E1 after a 20-d lag. In the absence of alternative carbon sources, LVW-12 and LVW-PC oxidized E2 to E1. This report documents the rapid and sometimes reversible microbial transformation of E1 and E2 and the slow degradation of 17α-ethinylestradiol in urban stream water and extends the list of known estrogen-transforming bacteria to the genera and . These results suggest that discharge of steroid estrogens via wastewater could be reduced through tighter control of redox conditions and may assist in future risk assessments detailing the environmental fate of estrogens through evidence that microbial estrogen transformations may be affected by environmental conditions or growth status.

Degradation and transport of veterinary antibiotics and estrogens in a vegetated buffer strip system

“…However, the formation of E2β in the present study may be due to the possibility of introducing intermittent anoxic conditions in the mesocosms when adjusting their soil moisture levels during incubation. Previous studies have reported the reduction of E1 to E2β in environmental matrices such as soil columns (Goeppert et al, 2015;Du et al, 2021), suspended swine manure under anerobic conditions (Prater et al, 2015), and inoculated water under anerobic conditions (Blunt et al, 2017). In Du et al, (2021) the reduction of E1 to E2β took place in sterilized soil suggesting this is not solely a biodegradation process but has abiotic transformation contribution as well.…”