title: Antibiotics and sweeteners in the aquatic environment: biodegradability, formation of phototransformation products, and in vitro toxicity.
abstract: In the present study, in vitro toxicity as well as biopersistence and photopersistence of four artificial sweeteners (acesulfame, cyclamate, saccharine, and sucralose) and five antibiotics (levofloxacin, lincomycin, linezolid, marbofloxacin, and sarafloxacin) and of their phototransformation products (PTPs) were investigated. Furthermore, antibiotic activity was evaluated after UV irradiation and after exposure to inocula of a sewage treatment plant. The study reveals that most of the tested compounds and their PTPs were neither readily nor inherently biodegradable in the Organisation for Economic Co-operation and Development (OECD)-biodegradability tests. The study further demonstrates that PTPs are formed upon irradiation with an Hg lamp (UV light) and, to a lesser extent, upon irradiation with a Xe lamp (mimics sunlight). Comparing the nonirradiated with the corresponding irradiated solutions, a higher chronic toxicity against bacteria was found for the irradiated solutions of linezolid. Neither cytotoxicity nor genotoxicity was found in human cervical (HeLa) and liver (Hep-G2) cells for any of the investigated compounds or their PTPs. Antimicrobial activity of the tested fluoroquinolones was reduced after UV treatment, but it was not reduced after a 28-day exposure to inocula of a sewage treatment plant. This comparative study shows that PTPs can be formed as a result of UV treatment. The study further demonstrated that UV irradiation can be effective in reducing the antimicrobial activity of antibiotics, and consequently may help to reduce antimicrobial resistance in wastewaters. Nevertheless, the study also highlights that some PTPs may exhibit a higher ecotoxicity than the respective parent compounds. Consequently, UV treatment does not transform all micropollutants into harmless compounds and may not be a large-scale effluent treatment option.
authors.affiliation: Department of Environmental Health Sciences, Section of Toxicology, University Medical Center Freiburg, Breisacher Strasse 115B, 79106, Freiburg, Germany. marlies.bergheim@gmail.com.|Institute of Earth and Environmental Sciences, University of Freiburg, Albertstrasse 23b, 79104, Freiburg, Germany. marlies.bergheim@gmail.com.
authors.forename: Marlies
authors.initials: M
authors.lastname: Bergheim
authors.affiliation: Department of Environmental Health Sciences, Section of Toxicology, University Medical Center Freiburg, Breisacher Strasse 115B, 79106, Freiburg, Germany. richard.gminski@uniklinik-freiburg.de.
authors.forename: Richard
authors.initials: R
authors.lastname: Gminski
authors.affiliation: Process Engineering and Environmental Technologies, University of Applied Sciences, Badstrasse 24, 77652, Offenburg, Germany. spangenberg@hs-offenburg.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Spangenberg
authors.affiliation: Molecular Toxicology Group, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany. debiakma@yahoo.com.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Debiak
authors.affiliation: Molecular Toxicology Group, Department of Biology, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany. Alexander.Buerkle@uni-konstanz.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bürkle
authors.affiliation: Department of Environmental Health Sciences, Section of Toxicology, University Medical Center Freiburg, Breisacher Strasse 115B, 79106, Freiburg, Germany. volker.mersch-sundermann@uniklinik-freiburg.de.
authors.forename: Volker
authors.initials: V
authors.lastname: Mersch-Sundermann
authors.affiliation: Department of Environmental Health Sciences, Section of Toxicology, University Medical Center Freiburg, Breisacher Strasse 115B, 79106, Freiburg, Germany. Klaus.Kuemmerer@uni.leuphana.de.|Institute of Sustainable and Environmental Chemistry, Leuphana University Lüneburg, Scharnhorststraße 1/C13, 21335, Lueneburg, Germany. Klaus.Kuemmerer@uni.leuphana.de.
authors.forename: Klaus
authors.initials: K
authors.lastname: Kümmerer
authors.affiliation: Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA, 19104-6316, USA. giere@sas.upenn.edu.
authors.forename: Reto
authors.initials: R
authors.lastname: Gieré
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D001673:Biodegradation, Environmental; D006367:HeLa Cells; D056945:Hep G2 Cells; D006801:Humans; D055668:Photochemical Processes; D012722:Sewage / Q000737:chemistry; D013549:Sweetening Agents / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D014466:Ultraviolet Rays; D018505:Waste Management; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity
chemical_list: D000900:Anti-Bacterial Agents; D012722:Sewage; D013549:Sweetening Agents; D014874:Water Pollutants, Chemical; D014867:Water
keywords: HeLa cells; Hep-G2 cells; Irradiation; Micropollutants; Photodegradation; UV; Vibrio fischeri