Detoxification and elimination of xenoestrogen nonylphenol by the filamentous fungus Aspergillus versicolor

Abstract 4-nonylophenol (4-NP) is a mixture of toxic degradation intermediates of non-ionic surfactants used worldwide, showing endocrine disrupting activity. Biodegradation of one of 4-NP isomers – 4- n -NP (non-branched isomer of 4-NP), was studied using the filamentous fungus Aspergillus versicolor IM 2161, which demonstrates high detoxification and mineralization capacity in cultures supplemented with 4- n -NP at an initial concentration of 100 mg L −1 . During 24 h of incubation in flasks or bioreactor (pO 2  ≥ 20%), 63 and 87.5% (respectively) of the toxic substrate was eliminated with nine by-products determined. Additional experiments with radioactive 4- n -NP [ring- 14 C(U)] showed that this xenobiotic is completely mineralized with the formation of CO 2 . Microscope inspection and yeast estrogen assay (YES) revealed direct correlation between 4- n -NP biodegradation and a decrease in toxicity in the fungus cultures. The final reduction in endocrine activity was 70.1 and 88.7% after 48 and 72 h of incubation (respectively) which indicates that the investigated strain of A. versicolor IM 2161 can be a convenient tool for decontamination of areas polluted with 4-NP.