title: Microbial ecotoxicity and mutagenicity of 1-hydroxypyrene and its photoproducts.
abstract: 1-Hydroxypyrene (1-HP) is a carcinogenic and slightly water-soluble polycyclic aromatic hydrocarbon. Ecotoxicity and mutagenicity of 1-HP and its photoproducts, and the effect of Mn2+ and Cu2+ on their mutagenicity were measured with microbial assay in this study. The assay includes spread plate counting, direct counting, microbial mineralization of 14C-UL-D-glucose and Mutatox Test. At the concentration examined (0.8 microM), the photoproducts (after 1.5 h solar irradiation) of 1-HP inhibited microbial glucose mineralization activity (by 64%) after microbial assemblages of a local reservoir site were exposed for 1 day. However, heterotrophic bacteria were able to utilize 1-HP photoproducts as the growth substrates and increase viability counts by up to 4.75-folds. 1-HP exhibited positive response to Mutatox Test in both direct medium and S-9 medium, with the lowest observable effective concentration of 0.625 microM in the test with direct medium. After photolysis, 1-HP decreased its mutagenicity. Mn2+ (312.5 microM-5 mM) and Cu2+ (6.25-100 microM) themselves are not mutagenic. However, addition of the metal ions before or after photolysis modifies the light readings of 1-HP during the test. Therefore, presence of metal ions could affect the genotoxicity of 1-HP in aquatic environments, depending on timing of the addition.
authors.affiliation: Department of Biology, Jackson State University, MS 39217, USA. hwang@ccaix.jsums.edu
authors.forename: H M
authors.initials: HM
authors.lastname: Hwang
authors.forename: X
authors.initials: X
authors.lastname: Shi
authors.forename: I
authors.initials: I
authors.lastname: Ero
authors.forename: A
authors.initials: A
authors.lastname: Jayasinghe
authors.forename: S
authors.initials: S
authors.lastname: Dong
authors.forename: H
authors.initials: H
authors.lastname: Yu
mesh_terms: D001681:Biological Assay; D003300:Copper / Q000737:chemistry*; D005947:Glucose / Q000378:metabolism*; D008345:Manganese / Q000737:chemistry*; D009153:Mutagens / Q000633:toxicity*; D010777:Photochemistry; D011721:Pyrenes / Q000737:chemistry / Q000633:toxicity*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009153:Mutagens; D011721:Pyrenes; D014874:Water Pollutants, Chemical; D008345:Manganese; D003300:Copper; D005947:Glucose; C033146:1-hydroxypyrene