@article {593,
	title = {Anaerobic benzene degradation.},
	journal = {Biodegradation},
	volume = {11},
	year = {2000},
	month = {2000},
	pages = {107-16},
	abstract = {Although many studies have indicated that benzene persists under anaerobic conditions in petroleum-contaminated environments, it has recently been documented that benzene can be anaerobically oxidized with most commonly considered electron acceptors for anaerobic respiration. These include: Fe(III), sulfate, nitrate, and possibly humic substances. Benzene can also be converted to methane and carbon dioxide under methanogenic conditions. There is evidence that benzene can be degraded under in situ conditions in petroleum-contaminated aquifers in which either Fe(III) reduction or methane production is the predominant terminal electron-accepting process. Furthermore, evidence from laboratory studies suggests that benzene may be anaerobically degraded in petroleum-contaminated marine sediments under sulfate-reducing conditions. Laboratory studies have suggested that within the Fe(III) reduction zone of petroleum-contaminated aquifers, benzene degradation can be stimulated with the addition of synthetic chelators which make Fe(III) more available for microbial reduction. The addition of humic substances and other compounds that contain quinone moieties can also stimulate anaerobic benzene degradation in laboratory incubations of Fe(III)-reducing aquifer sediments by providing an electron shuttle between Fe(III)-reducing microorganisms and insoluble Fe(III) oxides. Anaerobic benzene degradation in aquifer sediments can be stimulated with the addition of sulfate, but in some instances an inoculum of benzene-oxidizing, sulfate-reducing microorganisms must also be added. In a field trial, sulfate addition to the methanogenic zone of a petroleum-contaminated aquifer stimulated the growth and activity of sulfate-reducing microorganisms and enhanced benzene removal. Molecular phylogenetic studies have provided indications of what microorganisms might be involved in anaerobic benzene degradation in aquifers. The major factor limiting further understanding of anaerobic benzene degradation is the lack of a pure culture of an organism capable of anaerobic benzene degradation.},
	keywords = {Bacteria, Anaerobic, Benzene, Biodegradation, Environmental, Oxidation-Reduction},
	issn = {0923-9820},
	author = {Lovley, D R}
}
@article {619,
	title = {Microbial communities associated with anaerobic benzene degradation in a petroleum-contaminated aquifer.},
	journal = {Appl Environ Microbiol},
	volume = {65},
	year = {1999},
	month = {1999 Jul},
	pages = {3056-63},
	abstract = {Microbial community composition associated with benzene oxidation under in situ Fe(III)-reducing conditions in a petroleum-contaminated aquifer located in Bemidji, Minn., was investigated. Community structure associated with benzene degradation was compared to sediment communities that did not anaerobically oxidize benzene which were obtained from two adjacent Fe(III)-reducing sites and from methanogenic and uncontaminated zones. Denaturing gradient gel electrophoresis of 16S rDNA sequences amplified with bacterial or Geobacteraceae-specific primers indicated significant differences in the composition of the microbial communities at the different sites. Most notable was a selective enrichment of microorganisms in the Geobacter cluster seen in the benzene-degrading sediments. This finding was in accordance with phospholipid fatty acid analysis and most-probable-number-PCR enumeration, which indicated that members of the family Geobacteraceae were more numerous in these sediments. A benzene-oxidizing Fe(III)-reducing enrichment culture was established from benzene-degrading sediments and contained an organism closely related to the uncultivated Geobacter spp. This genus contains the only known organisms that can oxidize aromatic compounds with the reduction of Fe(III). Sequences closely related to the Fe(III) reducer Geothrix fermentans and the aerobe Variovorax paradoxus were also amplified from the benzene-degrading enrichment and were present in the benzene-degrading sediments. However, neither G. fermentans nor V. paradoxus is known to oxidize aromatic compounds with the reduction of Fe(III), and there was no apparent enrichment of these organisms in the benzene-degrading sediments. These results suggest that Geobacter spp. play an important role in the anaerobic oxidation of benzene in the Bemidji aquifer and that molecular community analysis may be a powerful tool for predicting a site{\textquoteright}s capacity for anaerobic benzene degradation.},
	keywords = {Anaerobiosis, Benzene, Biodegradation, Environmental, Culture Media, DNA, Bacterial, DNA, Ribosomal, Fresh Water, Geologic Sediments, Gram-Negative Anaerobic Bacteria, Molecular Sequence Data, Oxidation-Reduction, Petroleum, Phylogeny, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Sequence Analysis, DNA, Water Pollutants},
	issn = {0099-2240},
	author = {Rooney-Varga, J N and Anderson, R T and Fraga, J L and Ringelberg, D and Lovley, D R}
}
@article {626,
	title = {Anaerobic benzene degradation in petroleum-contaminated aquifer sediments after inoculation with a benzene-oxidizing enrichment.},
	journal = {Appl Environ Microbiol},
	volume = {64},
	year = {1998},
	month = {1998 Feb},
	pages = {775-8},
	abstract = {Sediments from the sulfate-reduction zone of a petroleum-contaminated aquifer, in which benzene persisted, were inoculated with a benzene-oxidizing, sulfate-reducing enrichment from aquatic sediments. Benzene was degraded, with apparent growth of the benzene-degrading population over time. These results suggest that the lack of benzene degradation in the sulfate-reduction zones of some aquifers may result from the failure of the appropriate benzene-degrading sulfate reducers to colonize the aquifers rather than from environmental conditions that are adverse for anaerobic benzene degradation.},
	keywords = {Anaerobiosis, Benzene, Biodegradation, Environmental, Fresh Water, Geologic Sediments, Iron, Oxidation-Reduction, Petroleum, Sulfates},
	issn = {0099-2240},
	author = {Weiner, JM and Lovley, D R}
}
@article {643,
	title = {Stimulated anoxic biodegradation of aromatic hydrocarbons using Fe(III) ligands.},
	journal = {Nature},
	volume = {370},
	year = {1994},
	month = {1994 Jul 14},
	pages = {128-31},
	abstract = {Contamination of ground waters with water-soluble aromatic hydrocarbons, common components of petroleum pollution, often produces anoxic conditions under which microbial degradation of the aromatics is slow. Oxygen is often added to contaminated ground water to stimulate biodegradation, but this can be technically difficult and expensive. Insoluble Fe(III) oxides, which are generally abundant in shallow aquifers, are alternative potential oxidants, but are difficult for microorganisms to access. Here we report that adding organic ligands that bind to Fe(III) dramatically increases its bioavailability, and that in the presence of these ligands, rates of degradation of aromatic hydrocarbons in anoxic aquifer sediments are comparable to those in oxic sediments. We find that even benzene, which is notoriously refractory in the absence of oxygen, can be rapidly degraded. Our results suggest that increasing the bioavailability of Fe(III) by adding suitable ligands provides a potential alternative to oxygen addition for the bioremediation of petroleum-contaminated aquifers.},
	keywords = {Benzene, Biodegradation, Environmental, Ferric Compounds, Hydrocarbons, Ligands, Methane, Nitrilotriacetic Acid, Oxidation-Reduction, Toluene, Water Pollutants, Chemical},
	issn = {0028-0836},
	doi = {10.1038/370128a0},
	author = {Lovley, D R and Woodward, J C and Chapelle, F H}
}
