@article {421,
	title = {Anaerobic oxidation of benzene by the hyperthermophilic archaeon Ferroglobus placidus.},
	journal = {Appl Environ Microbiol},
	volume = {77},
	year = {2011},
	month = {2011 Sep},
	pages = {5926-33},
	abstract = {Anaerobic benzene oxidation coupled to the reduction of Fe(III) was studied in Ferroglobus placidus in order to learn more about how such a stable molecule could be metabolized under strict anaerobic conditions. F. placidus conserved energy to support growth at 85{\textdegree}C in a medium with benzene provided as the sole electron donor and Fe(III) as the sole electron acceptor. The stoichiometry of benzene loss and Fe(III) reduction, as well as the conversion of [(14)C]benzene to [(14)C]carbon dioxide, was consistent with complete oxidation of benzene to carbon dioxide with electron transfer to Fe(III). Benzoate, but not phenol or toluene, accumulated at low levels during benzene metabolism, and [(14)C]benzoate was produced from [(14)C]benzene. Analysis of gene transcript levels revealed increased expression of genes encoding enzymes for anaerobic benzoate degradation during growth on benzene versus growth on acetate, but genes involved in phenol degradation were not upregulated during growth on benzene. A gene for a putative carboxylase that was more highly expressed in benzene- than in benzoate-grown cells was identified. These results suggest that benzene is carboxylated to benzoate and that phenol is not an important intermediate in the benzene metabolism of F. placidus. This is the first demonstration of a microorganism in pure culture that can grow on benzene under strict anaerobic conditions and for which there is strong evidence for degradation of benzene via clearly defined anaerobic metabolic pathways. Thus, F. placidus provides a much-needed pure culture model for further studies on the anaerobic activation of benzene in microorganisms.},
	keywords = {Anaerobiosis, Archaeoglobales, Benzene, Carbon Radioisotopes, Ferric Compounds, Gene Expression Profiling, Hot Temperature, Isotope Labeling, Oxidation-Reduction},
	issn = {1098-5336},
	doi = {10.1128/AEM.05452-11},
	author = {Holmes, Dawn E and Risso, Carla and Smith, Jessica A and Lovley, Derek R}
}
@article {434,
	title = {The genome of Geobacter bemidjiensis, exemplar for the subsurface clade of Geobacter species that predominate in Fe(III)-reducing subsurface environments.},
	journal = {BMC Genomics},
	volume = {11},
	year = {2010},
	month = {2010},
	pages = {490},
	abstract = {BACKGROUND: Geobacter species in a phylogenetic cluster known as subsurface clade 1 are often the predominant microorganisms in subsurface environments in which Fe(III) reduction is the primary electron-accepting process. Geobacter bemidjiensis, a member of this clade, was isolated from hydrocarbon-contaminated subsurface sediments in Bemidji, Minnesota, and is closely related to Geobacter species found to be abundant at other subsurface sites. This study examines whether there are significant differences in the metabolism and physiology of G. bemidjiensis compared to non-subsurface Geobacter species.

RESULTS: Annotation of the genome sequence of G. bemidjiensis indicates several differences in metabolism compared to previously sequenced non-subsurface Geobacteraceae, which will be useful for in silico metabolic modeling of subsurface bioremediation processes involving Geobacter species. Pathways can now be predicted for the use of various carbon sources such as propionate by G. bemidjiensis. Additional metabolic capabilities such as carbon dioxide fixation and growth on glucose were predicted from the genome annotation. The presence of different dicarboxylic acid transporters and two oxaloacetate decarboxylases in G. bemidjiensis may explain its ability to grow by disproportionation of fumarate. Although benzoate is the only aromatic compound that G. bemidjiensis is known or predicted to utilize as an electron donor and carbon source, the genome suggests that this species may be able to detoxify other aromatic pollutants without degrading them. Furthermore, G. bemidjiensis is auxotrophic for 4-aminobenzoate, which makes it the first Geobacter species identified as having a vitamin requirement. Several features of the genome indicated that G. bemidjiensis has enhanced abilities to respire, detoxify and avoid oxygen.

CONCLUSION: Overall, the genome sequence of G. bemidjiensis offers surprising insights into the metabolism and physiology of Geobacteraceae in subsurface environments, compared to non-subsurface Geobacter species, such as the ability to disproportionate fumarate, more efficient oxidation of propionate, enhanced responses to oxygen stress, and dependence on the environment for a vitamin requirement. Therefore, an understanding of the activity of Geobacter species in the subsurface is more likely to benefit from studies of subsurface isolates such as G. bemidjiensis than from the non-subsurface model species studied so far.},
	keywords = {Aldehyde Oxidoreductases, Biodegradation, Environmental, Carbohydrate Metabolism, Carbon Dioxide, Cell Wall, Electrons, Environmental Microbiology, Fatty Acids, Frameshift Mutation, Fumarates, Genes, Bacterial, Genome, Bacterial, Geobacter, Glucose, Iron, Metabolic Networks and Pathways, Multienzyme Complexes, Multigene Family, Osmosis, Oxidation-Reduction, Oxo-Acid-Lyases, Propionic Acids, Pyruvic Acid, Species Specificity, Surface Properties},
	issn = {1471-2164},
	doi = {10.1186/1471-2164-11-490},
	author = {Aklujkar, Muktak and Young, Nelson D and Holmes, Dawn and Chavan, Milind and Risso, Carla and Kiss, Hajnalka E and Han, Cliff S and Land, Miriam L and Lovley, Derek R}
}
@article {456,
	title = {Genome-scale comparison and constraint-based metabolic reconstruction of the facultative anaerobic Fe(III)-reducer Rhodoferax ferrireducens.},
	journal = {BMC Genomics},
	volume = {10},
	year = {2009},
	month = {2009},
	pages = {447},
	abstract = {BACKGROUND: Rhodoferax ferrireducens is a metabolically versatile, Fe(III)-reducing, subsurface microorganism that is likely to play an important role in the carbon and metal cycles in the subsurface. It also has the unique ability to convert sugars to electricity, oxidizing the sugars to carbon dioxide with quantitative electron transfer to graphite electrodes in microbial fuel cells. In order to expand our limited knowledge about R. ferrireducens, the complete genome sequence of this organism was further annotated and then the physiology of R. ferrireducens was investigated with a constraint-based, genome-scale in silico metabolic model and laboratory studies.

RESULTS: The iterative modeling and experimental approach unveiled exciting, previously unknown physiological features, including an expanded range of substrates that support growth, such as cellobiose and citrate, and provided additional insights into important features such as the stoichiometry of the electron transport chain and the ability to grow via fumarate dismutation. Further analysis explained why R. ferrireducens is unable to grow via photosynthesis or fermentation of sugars like other members of this genus and uncovered novel genes for benzoate metabolism. The genome also revealed that R. ferrireducens is well-adapted for growth in the subsurface because it appears to be capable of dealing with a number of environmental insults, including heavy metals, aromatic compounds, nutrient limitation and oxidative stress.

CONCLUSION: This study demonstrates that combining genome-scale modeling with the annotation of a new genome sequence can guide experimental studies and accelerate the understanding of the physiology of under-studied yet environmentally relevant microorganisms.},
	keywords = {Comamonadaceae, Comparative Genomic Hybridization, DNA, Bacterial, Ferric Compounds, Genome, Bacterial, Genomics, Models, Biological, Oxidation-Reduction, Sequence Analysis, DNA},
	issn = {1471-2164},
	doi = {10.1186/1471-2164-10-447},
	author = {Risso, Carla and Sun, Jun and Zhuang, Kai and Mahadevan, Radhakrishnan and DeBoy, Robert and Ismail, Wael and Shrivastava, Susmita and Huot, Heather and Kothari, Sagar and Daugherty, Sean and Bui, Olivia and Schilling, Christophe H and Lovley, Derek R and Meth{\'e}, Barbara A}
}
