Evaluating the ability of three in-vitro biotransformation models to remove selected antibiotics and 17 α-ethinylestradiol and identification of their respective transformation products

LUCAS SOSA ALDERETE ; ANDRÉS SAUVÊTRE ; SERGE CHIRON ; ĐORđE TADIć

Congreso; LIX Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research (SAIB); 2023

Three in-vitro biotransformation models (i.e., pure enzymes, hairy root and Trichoderma asperellum cultures) were used to evaluate the degradation of three antibiotics (sulfamethoxazole, trimethoprim and ofloxacin) and one synthetic hormone (17 α-ethinylestradiol); and investigated the relevance of the formation of transformation products (TPs) in constructed wetlands (CWs) bioaugmented with T. asperellum fungus. The identification of TPs was carried by high resolution mass spectrometry, using databases or by interpreting MS/MS spectra. Enzymatic assays with pure enzymes, such as peroxidase, laccase and β-glucosidase were performed to confirm the presence of TPs corresponding to phase I and II from metabolism of xenobiotic compounds (MXC), respectively. Results showed synergies in the transformation mechanisms between these three models. Phase II conjugation reactions and mainly glycosylation reactions were predominating in hairy root cultures while phase I metabolization reactions (e.g., hydroxylation and N-dealkylation) were predominating in T. asperellum culture. Following their accumulation/degradation kinetic profiles helped in determining the most relevant TPs. Identified TPs contributed to the overall residual antimicrobial activity because phase I metabolites can be more reactive and glucose-conjugated TPs can be transformed back into parent compounds. Similar to other biological treatments, the formation of TPs in CWs is of concern and deserves to be investigated with simple in-vitro models to avoid the complexity of the studies at field-scale. This work brings new findings on the emerging pollutants metabolic pathways established between T. asperellum and model plants, including extracellular secreted enzymes.