title: Persistence of polycyclic aromatic hydrocarbon components of creosote under anaerobic enrichment conditions.
abstract: Anaerobic biodegradation of an artificial mixture of polycyclic aromatic hydrocarbons (PAHs), which simulates the PAH component of creosote, was examined under methanogenic, sulfidogenic, and nitrate-reducing conditions using creosote-contaminated sediment as the source of inoculum. PAH degradation, CH4 formation and ion reduction were monitored for up to one year. Despite demonstrating active methanogenic and nitrate-reducing anaerobic bacterial communities, only limited degradation of a few PAHs was observed. Under methanogenic conditions limited degradation of all bicyclic (naphthalene, 1-and 2-methylnaphthalene, biphenyl, and 2,6-dimethylnaphthalene) and one tricyclic PAH, anthraquinone, was detected. 2-Methylanthracene was apparently degraded under nitrate-reducing conditions. Anthraquinone declined in sulfate enrichments, but this decline was not dependent upon sulfate reduction. None of the 4- or 5-ring PAHs were degraded under any of the enrichment conditions. These data indicate that under the anaerobic conditions tested there is only a limited potential to degrade PAHs which must be considered when proposing bioremediation technologies for PAH-contaminated sites, especially if high-molecular-weight PAHs are present.
authors.affiliation: Center for Environmental Diagnostics and Bioremediation, University of West Florida, Pensacola, Florida 32514, USA.
authors.forename: B R
authors.initials: BR
authors.lastname: Sharak Genthner
authors.forename: G T
authors.initials: GT
authors.lastname: Townsend
authors.forename: S E
authors.initials: SE
authors.lastname: Lantz
authors.forename: J G
authors.initials: JG
authors.lastname: Mueller
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism; D001673:Biodegradation, Environmental; D003407:Creosote / Q000737:chemistry / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D008970:Molecular Weight; D009566:Nitrates / Q000378:metabolism; D010084:Oxidation-Reduction; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D009566:Nitrates; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D003407:Creosote; D008697:Methane