<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Mouser, Paula J</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Perpetua, Lorrie A</style></author><author><style face="normal" font="default" size="100%">DiDonato, Raymond</style></author><author><style face="normal" font="default" size="100%">Postier, Brad</style></author><author><style face="normal" font="default" size="100%">Liu, Anna</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Quantifying expression of Geobacter spp. oxidative stress genes in pure culture and during in situ uranium bioremediation.</style></title><secondary-title><style face="normal" font="default" size="100%">ISME J</style></secondary-title><alt-title><style face="normal" font="default" size="100%">ISME J</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation, Environmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Colorado</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Profiling</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidative Stress</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil Microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Uranium</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2009 Apr</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">3</style></volume><pages><style face="normal" font="default" size="100%">454-65</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">As part of an effort to diagnose the physiological status of Geobacter species during in situ bioremediation of uranium-contaminated groundwater, transcript levels for two genes potentially associated with oxidative stress, cydA and sodA, were quantified throughout a bioremediation field study in Rifle, CO, USA. Despite the accumulation of Fe(II) in the groundwater, which is inconsistent with the presence of dissolved oxygen, both genes were highly expressed during the bioremediation process. Therefore, the response to oxidative stress was further evaluated with Geobacter uraniireducens, an isolate from the Rifle site. When G. uraniireducens cultured with fumarate as the electron acceptor was exposed to 5% oxygen for 8 h, there was a significant increase in cydA and sodA transcripts as well as other genes associated with oxygen respiration or oxidative stress. Oxygen-exposed cells had lower transcript abundance for genes associated with anaerobic respiration, metabolism and motility. Short-term oxygen exposure had little impact on cydA transcript levels, as more than 1 h was required for increases to levels comparable to the subsurface. Abundance of cydA and sodA transcripts for the isolate G. sulfurreducens were always higher in cells cultured with Fe(III) compared with fumarate as an electron acceptor, even when fumarate-grown cells were exposed to oxygen, and Fe(III)-grown cells were grown anaerobically. These results suggest that the apparently high Geobacter cydA and sodA expression during bioremediation cannot necessarily be attributed to oxidative stress and demonstrate that diagnosis of the metabolic status of subsurface microorganisms through transcript analysis should be coupled with appropriate geochemical analyses.</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/19129865?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Haveman, Shelley A</style></author><author><style face="normal" font="default" size="100%">Didonato, Raymond J</style></author><author><style face="normal" font="default" size="100%">Villanueva, Laura</style></author><author><style face="normal" font="default" size="100%">Shelobolina, Evgenya S</style></author><author><style face="normal" font="default" size="100%">Postier, Bradley L</style></author><author><style face="normal" font="default" size="100%">Xu, Bo</style></author><author><style face="normal" font="default" size="100%">Liu, Anna</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Genome-wide gene expression patterns and growth requirements suggest that Pelobacter carbinolicus reduces Fe(III) indirectly via sulfide production.</style></title><secondary-title><style face="normal" font="default" size="100%">Appl Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Appl. Environ. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetoin</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group</style></keyword><keyword><style  face="normal" font="default" size="100%">Deltaproteobacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Ethanol</style></keyword><keyword><style  face="normal" font="default" size="100%">Fermentation</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Profiling</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrilotriacetic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligonucleotide Array Sequence Analysis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Reverse Transcriptase Polymerase Chain Reaction</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Substrate Specificity</style></keyword><keyword><style  face="normal" font="default" size="100%">Sulfides</style></keyword><keyword><style  face="normal" font="default" size="100%">Sulfur</style></keyword><keyword><style  face="normal" font="default" size="100%">Sulfur-Reducing Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Thioredoxins</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2008</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2008 Jul</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">4277-84</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Although Pelobacter species are closely related to Geobacter species, recent studies suggested that Pelobacter carbinolicus may reduce Fe(III) via a different mechanism because it lacks the outer-surface c-type cytochromes that are required for Fe(III) reduction by Geobacter sulfurreducens. Investigation into the mechanisms for Fe(III) reduction demonstrated that P. carbinolicus had growth yields on both soluble and insoluble Fe(III) consistent with those of other Fe(III)-reducing bacteria. Comparison of whole-genome transcript levels during growth on Fe(III) versus fermentative growth demonstrated that the greatest apparent change in gene expression was an increase in transcript levels for four contiguous genes. These genes encode two putative periplasmic thioredoxins; a putative outer-membrane transport protein; and a putative NAD(FAD)-dependent dehydrogenase with homology to disulfide oxidoreductases in the N terminus, rhodanese (sulfurtransferase) in the center, and uncharacterized conserved proteins in the C terminus. Unlike G. sulfurreducens, transcript levels for cytochrome genes did not increase in P. carbinolicus during growth on Fe(III). P. carbinolicus could use sulfate as the sole source of sulfur during fermentative growth, but required elemental sulfur or sulfide for growth on Fe(III). The increased expression of genes potentially involved in sulfur reduction, coupled with the requirement for sulfur or sulfide during growth on Fe(III), suggests that P. carbinolicus reduces Fe(III) via an indirect mechanism in which (i) elemental sulfur is reduced to sulfide and (ii) the sulfide reduces Fe(III) with the regeneration of elemental sulfur. This contrasts with the direct reduction of Fe(III) that has been proposed for Geobacter species.</style></abstract><issue><style face="normal" font="default" size="100%">14</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18515480?dopt=Abstract</style></custom1></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Coppi, Maddalena V</style></author><author><style face="normal" font="default" size="100%">O'Neil, Regina A</style></author><author><style face="normal" font="default" size="100%">Leang, Ching</style></author><author><style face="normal" font="default" size="100%">Kaufmann, Franz</style></author><author><style face="normal" font="default" size="100%">Methé, Barbara A</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Liu, Anna</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Involvement of Geobacter sulfurreducens SfrAB in acetate metabolism rather than intracellular, respiration-linked Fe(III) citrate reduction.</style></title><secondary-title><style face="normal" font="default" size="100%">Microbiology</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Microbiology (Reading, Engl.)</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetates</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acid Transport Systems</style></keyword><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Membrane</style></keyword><keyword><style  face="normal" font="default" size="100%">Citric Acid Cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytoplasm</style></keyword><keyword><style  face="normal" font="default" size="100%">Energy Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Formic Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Deletion</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Profiling</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">NADH, NADPH Oxidoreductases</style></keyword><keyword><style  face="normal" font="default" size="100%">Oligonucleotide Array Sequence Analysis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2007 Oct</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">153</style></volume><pages><style face="normal" font="default" size="100%">3572-85</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A soluble ferric reductase, SfrAB, which catalysed the NADPH-dependent reduction of chelated Fe(III), was previously purified from the dissimilatory Fe(III)-reducing micro-organism Geobacter sulfurreducens, suggesting that reduction of chelated forms of Fe(III) might be cytoplasmic. However, metabolically active spheroplast suspensions could not catalyse acetate-dependent Fe(III) citrate reduction, indicating that periplasmic and/or outer-membrane components were required for Fe(III) citrate reduction. Furthermore, phenotypic analysis of an SfrAB knockout mutant suggested that SfrAB was involved in acetate metabolism rather than respiration-linked Fe(III) reduction. The mutant could not grow via the reduction of either Fe(III) citrate or fumarate when acetate was the electron donor but could grow with either acceptor if either hydrogen or formate served as the electron donor. Following prolonged incubation in acetate : fumarate medium in the absence of hydrogen and formate, an 'acetate-adapted' SfrAB-null strain was isolated that was capable of growth on acetate : fumarate medium but not acetate : Fe(III) citrate medium. Comparison of gene expression in this strain with that of the wild-type revealed upregulation of a potential NADPH-dependent ferredoxin oxidoreductase as well as genes involved in energy generation and amino acid uptake, suggesting that NADPH homeostasis and the tricarboxylic acid (TCA) cycle were perturbed in the 'acetate-adapted' SfrAB-null strain. Membrane and soluble fractions prepared from the 'acetate-adapted' strain were depleted of NADPH-dependent Fe(III), viologen and quinone reductase activities. These results indicate that cytoplasmic, respiration-linked reduction of Fe(III) by SfrAB in vivo is unlikely and suggest that deleting SfrAB may interfere with growth via acetate oxidation by interfering with NADP regeneration.</style></abstract><issue><style face="normal" font="default" size="100%">Pt 10</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17906154?dopt=Abstract</style></custom1></record></records></xml>