Fungal transformation of 17α-ethinylestradiol in the presence of various concentrations of sodium chloride

Abstract

17α-Ethinylestradiol (EE2) is a commonly used synthetic estrogen, which is resistant to degradation and accumulates in all parts of the environment. In this work the capability of thirty eight fungal strains to remove this xenobiotic from culture medium was checked. Nine out of the tested strains were able to completely remove EE2 (at initial concentration 10 mg l−1) from the culture medium during 3 d of incubation. The most efficient were two Aspergillus strains (Aspergillus fumigatus IM 6510 and Aspergillus versicolor IM 2161) which also possess the ability to eliminate the xenoestrogen in the presence of NaCl. A. versicolor seems to be less vulnerable to salinity and the transformation process was completed after 3 d of incubation in all tested NaCl concentrations. This strain transformed EE2 and formed its metabolites detected during liquid chromatography–(electrospray) triple quadrupole–mass spectrometry (LC–(ESI)MS–MS) analysis. The quantitative analyses revealed that the EE2 subsequent decrease in samples with or without salinity was accompanied by an increase in the concentrations of estrone (E1) and estradiol (E2). The presence of NaCl slightly inhibited E2 to E1 transformation during the first 24 h of incubation but at the end of the experiment the amount of nontoxic E1 prevailed in all tested samples. The results of this study suggest that Aspergillus sp. possesses an ability to utilize EE2 in the presence of NaCl.