title: Role of biotransformation, sorption and mineralization of (14)C-labelled sulfamethoxazole under different redox conditions.
abstract: (14)C-sulfamethoxazole biotransformation, sorption and mineralization was studied with heterotrophic and autotrophic biomass under aerobic and anoxic conditions, as well as with anaerobic biomass. The (14)C-radiolabelled residues distribution in the solid, liquid and gas phases was closely monitored along a total incubation time of 190 h. Biotransformation was the main removal mechanism, mineralization and sorption remaining below 5% in all the cases, although the presence of a carbon source exerted a positive effect on the mineralization rate by the aerobic heterotrophic bacteria. In fact, an influence of the type of primary substrate and the redox potential was observed in all cases on the biotransformation and mineralization rates, since an enhancement of the removal rate was observed when an external carbon source was used as a primary substrate under aerobic conditions, while a negligible effect was observed under nitrifying conditions. In the liquid phases collected from all assays, up to three additional peaks corresponding to (14)C-radiolabelled residues were detected. The highest concentration was observed under anaerobic conditions, where two radioactive metabolites were detected representing each around 15% of the total applied radioactivity after 180 h incubation. One of the metabolites detected under anoxic and anaerobic conditions, is probably resulting from ring cleavage of the isoxazole ring.
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain. Electronic address: teresa.alvarino@usc.es.
authors.forename: T
authors.initials: T
authors.lastname: Alvarino
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, 40 Grundenstrasse, CH 4132 Muttenz, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Nastold
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Suarez
authors.affiliation: Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, E-15782 Santiago de Compostela, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Omil
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, 40 Grundenstrasse, CH 4132 Muttenz, Switzerland; State Key Laboratory for Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: P F X
authors.initials: PF
authors.lastname: Corvini
authors.affiliation: Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, 40 Grundenstrasse, CH 4132 Muttenz, Switzerland.
authors.forename: H
authors.initials: H
authors.lastname: Bouju
mesh_terms: D000327:Adsorption; D000890:Anti-Infective Agents / Q000737:chemistry / Q000378:metabolism*; D001420:Bacteria, Aerobic; D001673:Biodegradation, Environmental; D001711:Biotransformation; D002250:Carbon Radioisotopes; D010084:Oxidation-Reduction; D013420:Sulfamethoxazole / Q000737:chemistry / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D002250:Carbon Radioisotopes; D013420:Sulfamethoxazole
keywords: Biotransformation; Metabolite; Mineralization; Redox potential; Sulfamethoxazole