title: Identification of mutagens in freshwater sediments by the Ames-fluctuation assay using nitroreductase and acetyltransferase overproducing test strains.
abstract: Extracts of sediments from an area of concern in the Elbe river basins (Spittelwasser creek) were analyzed with the Ames-fluctuation test and in parallel with gas chromatography/mass spectrometry for compound identification. The standard test strains TA 98 and TA 100 showed mutagenicity mainly in medium-polar fractions of the sediment extracts. PAHs contribute to the overall mutagenic potential of the sample. Especially, cyclopenta[c,d]pyrene that was previously not defined as a priority hazardous substance has to be considered as well. The addition of metabolically competent test strains, which overexpress nitroreductase and acetyltransferase (e.g., YG1041 and YG1042) to the test battery, increased significantly the sensitivity of the Ames test for medium polar to polar genotoxins. The increased mutagenicity that was found in these bacterial strains indicates the presence of nitroarenes and/or aromatic amines. In fact, a number of heterocyclic and nitrogen-substituted aromatic compounds were identified in the sediments of the Spittelwasser creek of which methyl parathion, 1-naphthylamine, and N-phenyl-2-naphthylamine are mutagenic.
authors.affiliation: Division of Qualitative Hydrology, German Federal Institute of Hydrology (BfG), Am Mainzer Tor 1, Koblenz 56068, Germany. reifferscheid@bafg.de
authors.forename: Georg
authors.initials: G
authors.lastname: Reifferscheid
authors.forename: Sebastian
authors.initials: S
authors.lastname: Buchinger
authors.forename: Zhi
authors.initials: Z
authors.lastname: Cao
authors.forename: Evelyn
authors.initials: E
authors.lastname: Claus
mesh_terms: D000123:Acetyltransferases / Q000378:metabolism*; D000588:Amines / Q000032:analysis / Q000633:toxicity; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water; D019015:Geologic Sediments; D009152:Mutagenicity Tests / Q000379:methods*; D009153:Mutagens / Q000032:analysis* / Q000633:toxicity; D009601:Nitroreductases / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D012486:Salmonella typhimurium / Q000187:drug effects / Q000201:enzymology
chemical_list: D000588:Amines; D009153:Mutagens; D011084:Polycyclic Aromatic Hydrocarbons; D009601:Nitroreductases; D000123:Acetyltransferases