Removal of 17α-ethinylestradiol from a sterile WC medium by the cyanobacteria Microcystis novacekii.
An unprecedented investigation dealing with the removal of 17α-ethinylestradiol (EE2, a contraceptive hormone) by the cyanobacteria Microcystis novacekii (a species that is abundant and easily accessible in Brazilian lakes) from a sterile WC medium is described herein. The results indicated that whereas EE2 experienced insignificant spontaneous degradation, Microcystis novacekii was capable of removing ca. 65% of the hormone from the culture medium. Furthermore, no metabolites were detected at the concentration levels evaluated (0.10 to 0.17 mg L(-1)) as verified by the use of GC-MS, a quite sensitive analytical technique, and adequate pre-concentration procedures (SPME and liquid extraction). Elucidative experiments, including an appropriate cell lyses procedure, indicated that EE2 was likely accumulated within the cells (bioaccumulation) rather than adsorbed on the cellular membrane (biosorption). Moreover, the intra- and extracellular contents of EE2 were shown to be roughly complementary. Finally, the species was found to be highly tolerant to the hormone as its growth rates were higher in the test than in the control experiments. All these findings, therefore, point to the use of Microcystis novacekii as a potential agent to treat effluents contaminated with EE2.
Laboratory of Mass Spectrometry, Department of Chemistry, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais 31270-901, Brazil. isabelafioravante@yahoo.com.br
Isabela Araujo
IA
Fioravante
Bruna
B
Albergaria
Taciane Silveira
TS
Teodoro
Sérgia Maria
SM
Starling Magalhães
Francisco
F
Barbosa
Rodinei
R
Augusti
D001673:Biodegradation, Environmental; D001938:Brazil; D003470:Culture Media / Q000737:chemistry; D004997:Ethinyl Estradiol / Q000032:analysis / Q000378:metabolism*; D046931:Microcystis / Q000254:growth & development / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
D003470:Culture Media; D014874:Water Pollutants, Chemical; D004997:Ethinyl Estradiol