@article {3045,
	title = {H Is a Major Intermediate in  Corrosion of Iron.},
	journal = {mBio},
	volume = {14},
	year = {2023},
	month = {2023 Apr 25},
	pages = {e0007623},
	abstract = {<p>Desulfovibrio vulgaris has been a primary pure culture sulfate reducer for developing microbial corrosion concepts. Multiple mechanisms for how it accepts electrons from Fe have been proposed. We investigated Fe oxidation with a mutant of  in which hydrogenase genes were deleted. The hydrogenase mutant grew as well as the parental strain with lactate as the electron donor, but unlike the parental strain, it was not able to grow on H. The parental strain reduced sulfate with Fe as the sole electron donor, but the hydrogenase mutant did not. H accumulated over time in Fe cultures of the hydrogenase mutant and sterile controls but not in parental strain cultures. Sulfide stimulated H production in uninoculated controls apparently by both reacting with Fe to generate H and facilitating electron transfer from Fe to H. Parental strain supernatants did not accelerate H production from Fe, ruling out a role for extracellular hydrogenases. Previously proposed electron transfer between Fe and  via soluble electron shuttles was not evident. The hydrogenase mutant did not reduce sulfate in the presence of Fe and either riboflavin or anthraquinone-2,6-disulfonate, and these potential electron shuttles did not stimulate parental strain sulfate reduction with Fe as the electron donor. The results demonstrate that  primarily accepts electrons from Fe via H as an intermediary electron carrier. These findings clarify the interpretation of previous  corrosion studies and suggest that H-mediated electron transfer is an important mechanism for iron corrosion under sulfate-reducing conditions.  Microbial corrosion of iron in the presence of sulfate-reducing microorganisms is economically significant. There is substantial debate over how microbes accelerate iron corrosion. Tools for genetic manipulation have only been developed for a few Fe(III)-reducing and methanogenic microorganisms known to corrode iron and in each case those microbes were found to accept electrons from Fe via direct electron transfer. However, iron corrosion is often most intense in the presence of sulfate-reducing microbes. The finding that Desulfovibrio vulgaris relies on H to shuttle electrons between Fe and cells revives the concept, developed in some of the earliest studies on microbial corrosion, that sulfate reducers consumption of H is a major microbial corrosion mechanism. The results further emphasize that direct Fe-to-microbe electron transfer has yet to be rigorously demonstrated in sulfate-reducing microbes.</p>},
	keywords = {Corrosion, Desulfovibrio, Desulfovibrio vulgaris, Hydrogenase, Iron, Lactic Acid, Oxidation-Reduction, Sulfates},
	issn = {2150-7511},
	doi = {10.1128/mbio.00076-23},
	author = {Woodard, Trevor L and Ueki, Toshiyuki and Lovley, Derek R}
}
@article {3135,
	title = {Sulfur oxidation to sulfate coupled with electron transfer to electrodes by Desulfuromonas strain TZ1.},
	journal = {Microbiology (Reading)},
	volume = {160},
	year = {2014},
	month = {2014 Jan},
	pages = {123-129},
	abstract = {<p>Microbial oxidation of elemental sulfur with an electrode serving as the electron acceptor is of interest because this may play an important role in the recovery of electrons from sulfidic wastes and for current production in marine benthic microbial fuel cells. Enrichments initiated with a marine sediment inoculum, with elemental sulfur as the electron donor and a positively poised (+300 mV versus Ag/AgCl) anode as the electron acceptor, yielded an anode biofilm with a diversity of micro-organisms, including Thiobacillus, Sulfurimonas, Pseudomonas, Clostridium and Desulfuromonas species. Further enrichment of the anode biofilm inoculum in medium with elemental sulfur as the electron donor and Fe(III) oxide as the electron acceptor, followed by isolation in solidified sulfur/Fe(III) medium yielded a strain of Desulfuromonas, designated strain TZ1. Strain TZ1 effectively oxidized elemental sulfur to sulfate with an anode serving as the sole electron acceptor, at rates faster than Desulfobulbus propionicus, the only other organism in pure culture previously shown to oxidize S{\textdegree} with current production. The abundance of Desulfuromonas species enriched on the anodes of marine benthic fuel cells has previously been interpreted as acetate oxidation driving current production, but the results presented here suggest that sulfur-driven current production is a likely alternative.</p>},
	keywords = {Bioelectric Energy Sources, Desulfuromonas, DNA, Bacterial, Electricity, Electrodes, Geologic Sediments, Molecular Sequence Data, Oxidation-Reduction, Sequence Analysis, DNA, Sulfates, Sulfur},
	issn = {1465-2080},
	doi = {10.1099/mic.0.069930-0},
	author = {Zhang, Tian and Bain, Timothy S and Barlett, Melissa A and Dar, Shabir A and Snoeyenbos-West, Oona L and Nevin, Kelly P and Lovley, Derek R}
}
@article {474,
	title = {Quantification of Desulfovibrio vulgaris dissimilatory sulfite reductase gene expression during electron donor- and electron acceptor-limited growth.},
	journal = {Appl Environ Microbiol},
	volume = {74},
	year = {2008},
	month = {2008 Sep},
	pages = {5850-3},
	abstract = {Previous studies have suggested that levels of transcripts for dsrA, a gene encoding a subunit of the dissimilatory sulfite reductase, are not directly related to the rates of sulfate reduction in sediments under all conditions. This phenomenon was further investigated with chemostat-grown Desulfovibrio vulgaris. Under sulfate-limiting conditions, dsrA transcript levels increased as the bulk rates of sulfate reduction in the chemostat increased, but transcript levels were similar at all sulfate reduction rates under electron donor-limiting conditions. When both electron donor- and electron acceptor-limiting conditions were considered, there was a direct correspondence between dsrA transcript levels and the rates of sulfate reduction per cell. These results suggest that dsrA transcript levels may provide important information on the metabolic state of sulfate reducers.},
	keywords = {Desulfovibrio vulgaris, Electron Transport, Gene Expression, Geologic Sediments, Hydrogensulfite Reductase, Oxidation-Reduction, RNA, Bacterial, RNA, Messenger, Sulfates},
	issn = {1098-5336},
	doi = {10.1128/AEM.00399-08},
	author = {Villanueva, Laura and Haveman, Shelley A and Summers, Zara M and Lovley, Derek R}
}
@article {482,
	title = {Sustained removal of uranium from contaminated groundwater following stimulation of dissimilatory metal reduction.},
	journal = {Environ Sci Technol},
	volume = {42},
	year = {2008},
	month = {2008 Apr 15},
	pages = {2999-3004},
	abstract = {Previous field studies on in situ bioremediation of uranium-contaminated groundwater in an aquifer in Rifle, Colorado identified two distinct phases following the addition of acetate to stimulate microbial respiration. In phase I, Geobacter species are the predominant organisms, Fe(III) is reduced, and microbial reduction of soluble U(VI) to insoluble U(IV) removes uranium from the groundwater. In phase II, Fe(III) is depleted, sulfate is reduced, and sulfate-reducing bacteria predominate. Long-term monitoring revealed an unexpected third phase during which U(VI) removal continues even after acetate additions are stopped. All three of these phases were successfully reproduced in flow-through sediment columns. When sediments from the third phase were heat sterilized, the capacity for U(VI) removal was lost. In the live sediments U(VI) removed from the groundwater was recovered as U(VI) in the sediments. This contrasts to the recovery of U(IV) in sediments resulting from the reduction of U(VI) to U(IV) during the Fe(III) reduction phase in acetate-amended sediments. Analysis of 16S rRNA gene sequences in the sediments in which U(VI) was being adsorbed indicated that members of the Firmicutes were the predominant organisms whereas no Firmicutes sequences were detected in background sediments which did not have the capacity to sorb U(VI), suggesting that the U(VI) adsorption might be due to the presence of these living organisms or at least their intact cell components. This unexpected enhanced adsorption of U(VI) onto sediments following the stimulation of microbial growth in the subsurface may potentially enhance the cost effectiveness of in situ uranium bioremediation.},
	keywords = {Acetates, Adsorption, Bacteria, Colorado, Geologic Sediments, Oxidation-Reduction, RNA, Ribosomal, 16S, Sulfates, Uranium, Water Pollutants, Radioactive, Water Supply},
	issn = {0013-936X},
	author = {N{\textquoteright}guessan, Lucie A and Vrionis, Helen A and Resch, Charles T and Long, Philip E and Lovley, Derek R}
}
@article {530,
	title = {Microbiological and geochemical heterogeneity in an in situ uranium bioremediation field site.},
	journal = {Appl Environ Microbiol},
	volume = {71},
	year = {2005},
	month = {2005 Oct},
	pages = {6308-18},
	abstract = {The geochemistry and microbiology of a uranium-contaminated subsurface environment that had undergone two seasons of acetate addition to stimulate microbial U(VI) reduction was examined. There were distinct horizontal and vertical geochemical gradients that could be attributed in large part to the manner in which acetate was distributed in the aquifer, with more reduction of Fe(III) and sulfate occurring at greater depths and closer to the point of acetate injection. Clone libraries of 16S rRNA genes derived from sediments and groundwater indicated an enrichment of sulfate-reducing bacteria in the order Desulfobacterales in sediment and groundwater samples. These samples were collected nearest the injection gallery where microbially reducible Fe(III) oxides were highly depleted, groundwater sulfate concentrations were low, and increases in acid volatile sulfide were observed in the sediment. Further down-gradient, metal-reducing conditions were present as indicated by intermediate Fe(II)/Fe(total) ratios, lower acid volatile sulfide values, and increased abundance of 16S rRNA gene sequences belonging to the dissimilatory Fe(III)- and U(VI)-reducing family Geobacteraceae. Maximal Fe(III) and U(VI) reduction correlated with maximal recovery of Geobacteraceae 16S rRNA gene sequences in both groundwater and sediment; however, the sites at which these maxima occurred were spatially separated within the aquifer. The substantial microbial and geochemical heterogeneity at this site demonstrates that attempts should be made to deliver acetate in a more uniform manner and that closely spaced sampling intervals, horizontally and vertically, in both sediment and groundwater are necessary in order to obtain a more in-depth understanding of microbial processes and the relative contribution of attached and planktonic populations to in situ uranium bioremediation.},
	keywords = {Acetates, Biodegradation, Environmental, Deltaproteobacteria, DNA, Bacterial, DNA, Ribosomal, Ferric Compounds, Fresh Water, Geologic Sediments, Phylogeny, Polymerase Chain Reaction, RNA, Ribosomal, 16S, Sulfates, Uranium, Water Pollution},
	issn = {0099-2240},
	doi = {10.1128/AEM.71.10.6308-6318.2005},
	author = {Vrionis, Helen A and Anderson, Robert T and Ortiz-Bernad, Irene and O{\textquoteright}Neill, Kathleen R and Resch, Charles T and Peacock, Aaron D and Dayvault, Richard and White, David C and Long, Philip E and Lovley, Derek R}
}
@article {559,
	title = {Electron transfer by Desulfobulbus propionicus to Fe(III) and graphite electrodes.},
	journal = {Appl Environ Microbiol},
	volume = {70},
	year = {2004},
	month = {2004 Feb},
	pages = {1234-7},
	abstract = {Desulfobulbus propionicus was able to grow with Fe(III), the humic acids analog anthraquinone-2,6-disulfonate (AQDS), or a graphite electrode as an electron acceptor. These results provide an explanation for the enrichment of Desulfobulbaceae species on the surface of electrodes harvesting electricity from anaerobic marine sediments and further expand the diversity of microorganisms known to have the ability to use both sulfate and Fe(III) as an electron acceptor.},
	keywords = {Culture Media, Deltaproteobacteria, Electrodes, Electron Transport, Ferric Compounds, Graphite, Oxidation-Reduction, Pyruvic Acid, Sulfates},
	issn = {0099-2240},
	author = {Holmes, Dawn E and Bond, Daniel R and Lovley, Derek R}
}
@article {566,
	title = {Metabolism of organic compounds in anaerobic, hydrothermal sulphate-reducing marine sediments.},
	journal = {Environ Microbiol},
	volume = {5},
	year = {2003},
	month = {2003 Jul},
	pages = {583-91},
	abstract = {Previous studies of hot (>80 degrees C) microbial ecosystems have primarily relied on the study of pure cultures or analysis of 16S rDNA sequences. In order to gain more information on anaerobic metabolism by natural communities in hot environments, sediments were collected from a shallow marine hydrothermal vent system in Baia di Levante, Vulcano, Italy and incubated under strict anaerobic conditions at 90 degrees C. Sulphate reduction was the predominant terminal electron-accepting process in the sediments. The addition of molybdate inhibited sulphate reduction in the sediments and resulted in a linear accumulation of acetate and hydrogen over time. [U-14C]- acetate was completely oxidized to 14CO2, and the addition of molybdate inhibited 14CO2 production by 60\%. [U-14C]-glucose was oxidized to 14CO2, and this was inhibited when molybdate was added. When the pool sizes of short-chain fatty acids were artificially increased, radiolabel from [U-14C]-glucose accumulated in the acetate pool. L-[U-14C]-glutamate, [ring-14C]-benzoate and [U-14C]-palmitate were also anaerobically oxidized to 14CO2 in the sediments, but molybdate had little effect on the oxidation of these compounds. These results demonstrate that natural microbial communities living in a hot, microbial ecosystem can oxidize acetate and a range of other organic electron donors under sulphate-reducing conditions and suggest that acetate is an important extracellular intermediate in the anaerobic degradation of organic matter in hot microbial ecosystems.},
	keywords = {Acetates, Anaerobiosis, Bacteria, Anaerobic, Benzoates, Carbon Dioxide, Ecosystem, Geologic Sediments, Glucose, Glutamic Acid, Hot Temperature, Hydrogen, Italy, Molybdenum, Organic Chemicals, Oxidation-Reduction, Palmitates, Seawater, Sulfates, Water Microbiology},
	issn = {1462-2912},
	author = {Tor, Jason M and Amend, Jan P and Lovley, Derek R}
}
@article {563,
	title = {Stimulating the in situ activity of Geobacter species to remove uranium from the groundwater of a uranium-contaminated aquifer.},
	journal = {Appl Environ Microbiol},
	volume = {69},
	year = {2003},
	month = {2003 Oct},
	pages = {5884-91},
	abstract = {The potential for removing uranium from contaminated groundwater by stimulating the in situ activity of dissimilatory metal-reducing microorganisms was evaluated in a uranium-contaminated aquifer located in Rifle, Colo. Acetate (1 to 3 mM) was injected into the subsurface over a 3-month period via an injection gallery composed of 20 injection wells, which was installed upgradient from a series of 15 monitoring wells. U(VI) concentrations decreased in as little as 9 days after acetate injection was initiated, and within 50 days uranium had declined below the prescribed treatment level of 0.18 micro M in some of the monitoring wells. Analysis of 16S ribosomal DNA (rDNA) sequences and phospholipid fatty acid profiles demonstrated that the initial loss of uranium from the groundwater was associated with an enrichment of Geobacter species in the treatment zone. Fe(II) in the groundwater also increased during this period, suggesting that U(VI) reduction was coincident with Fe(III) reduction. As the acetate injection continued over 50 days there was a loss of sulfate from the groundwater and an accumulation of sulfide and the composition of the microbial community changed. Organisms with 16S rDNA sequences most closely related to those of sulfate reducers became predominant, and Geobacter species became a minor component of the community. This apparent switch from Fe(III) reduction to sulfate reduction as the terminal electron accepting process for the oxidation of the injected acetate was associated with an increase in uranium concentration in the groundwater. These results demonstrate that in situ bioremediation of uranium-contaminated groundwater is feasible but suggest that the strategy should be optimized to better maintain long-term activity of Geobacter species.},
	keywords = {Acetates, DNA, Ribosomal, Ecosystem, Fatty Acids, Ferric Compounds, Fresh Water, Geobacter, Mining, Oxidation-Reduction, Phospholipids, RNA, Ribosomal, 16S, Sulfates, Uranium, Water Pollution, Chemical},
	issn = {0099-2240},
	author = {Anderson, Robert T and Vrionis, Helen A and Ortiz-Bernad, Irene and Resch, Charles T and Long, Philip E and Dayvault, Richard and Karp, Ken and Marutzky, Sam and Metzler, Donald R and Peacock, Aaron and White, David C and Lowe, Mary and Lovley, Derek R}
}
@article {579,
	title = {Rapid evolution of redox processes in a petroleum hydrocarbon-contaminated aquifer.},
	journal = {Ground Water},
	volume = {40},
	year = {2002},
	month = {2002 Jul-Aug},
	pages = {353-60},
	abstract = {Ground water chemistry data collected over a six-year period show that the distribution of contaminants and redox processes in a shallow petroleum hydrocarbon-contaminated aquifer has changed rapidly over time. Shortly after a gasoline release occurred in 1990, high concentrations of benzene were present near the contaminant source area. In this contaminated zone, dissolved oxygen in ground water was depleted, and by 1994 Fe(III) reduction and sulfate reduction were the predominant terminal electron accepting processes. Significantly, dissolved methane was below measurable levels in 1994, indicating the absence of significant methanogenesis. By 1996, however, depletion of solid-phase Fe(III)-oxyhydrox ides in aquifer sediments and depletion of dissolved sulfate in ground water resulted in the onset of methanogenesis. Between 1996 and 2000, water-chemistry data indicated that methanogenic metabolism became increasingly prevalent. Molecular analysis of 16S-rDNA extracted from sediments shows the presence of a more diverse methanogenic community inside as opposed to outside the plume core, and is consistent with water-chemistry data indicating a shift toward methanogenesis over time. This rapid evolution of redox processes reflects several factors including the large amounts of contaminants, relatively rapid ground water flow (approximately 0.3 m/day [approximately foot/day]), and low concentrations of microbially reducible Fe(III) oxyhydroxides ( approximately 1 micromol/g) initially present in aquifer sediments. These results illustrate that, under certain hydrologic conditions, redox conditions in petroleum hydrocarbon-contaminated aquifers can change rapidly in time and space, and that the availability of solid-phase Fe(III)-oxyhydroxides affects this rate of change.},
	keywords = {Hydrocarbons, Iron, Methane, Oxidation-Reduction, Petroleum, Soil Pollutants, Solubility, Sulfates, Water Pollutants, Water Supply},
	issn = {0017-467X},
	author = {Chapelle, Francis H and Bradley, Paul M and Lovley, Derek R and O{\textquoteright}Neill, Kathleen and Landmeyer, James E}
}
