<?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%">Zhou, Enze</style></author><author><style face="normal" font="default" size="100%">Li, Feng</style></author><author><style face="normal" font="default" size="100%">Zhang, Dawei</style></author><author><style face="normal" font="default" size="100%">Xu, Dake</style></author><author><style face="normal" font="default" size="100%">Li, Zhong</style></author><author><style face="normal" font="default" size="100%">Jia, Ru</style></author><author><style face="normal" font="default" size="100%">Jin, Yuting</style></author><author><style face="normal" font="default" size="100%">Song, Hao</style></author><author><style face="normal" font="default" size="100%">Li, Huabing</style></author><author><style face="normal" font="default" size="100%">Wang, Qiang</style></author><author><style face="normal" font="default" size="100%">Wang, Jianjun</style></author><author><style face="normal" font="default" size="100%">Li, Xiaogang</style></author><author><style face="normal" font="default" size="100%">Gu, Tingyue</style></author><author><style face="normal" font="default" size="100%">Homborg, Axel M</style></author><author><style face="normal" font="default" size="100%">Mol, Johannes M C</style></author><author><style face="normal" font="default" size="100%">Smith, Jessica A</style></author><author><style face="normal" font="default" size="100%">Wang, Fuhui</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%">Direct microbial electron uptake as a mechanism for stainless steel corrosion in aerobic environments.</style></title><secondary-title><style face="normal" font="default" size="100%">Water Res</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Water Res</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biofilms</style></keyword><keyword><style  face="normal" font="default" size="100%">Corrosion</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Metals</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Stainless Steel</style></keyword><keyword><style  face="normal" font="default" size="100%">Steel</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2022</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2022 Jul 01</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">219</style></volume><pages><style face="normal" font="default" size="100%">118553</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Shewanella oneidensis MR-1 is an attractive model microbe for elucidating the biofilm-metal interactions that contribute to the billions of dollars in corrosion damage to industrial applications each year. Multiple mechanisms for S. oneidensis-enhanced corrosion have been proposed, but none of these mechanisms have previously been rigorously investigated with methods that rule out alternative routes for electron transfer. We found that S. oneidensis grown under aerobic conditions formed thick biofilms (∼50 µm) on stainless steel coupons, accelerating corrosion over sterile controls. H and flavins were ruled out as intermediary electron carriers because stainless steel did not reduce riboflavin and previous studies have demonstrated stainless does not generate H. Strain ∆mtrCBA, in which the genes for the most abundant porin-cytochrome conduit in S. oneidensis were deleted, corroded stainless steel substantially less than wild-type in aerobic cultures. Wild-type biofilms readily reduced nitrate with stainless steel as the sole electron donor under anaerobic conditions, but strain ∆mtrCBA did not. These results demonstrate that S. oneidensis can directly consume electrons from iron-containing metals and illustrate how direct metal-to-microbe electron transfer can be an important route for corrosion, even in aerobic environments.&lt;/p&gt;</style></abstract><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/35561622?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%">Lovley, Derek R</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Electrotrophy: Other microbial species, iron, and electrodes as electron donors for microbial respirations.</style></title><secondary-title><style face="normal" font="default" size="100%">Bioresour Technol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Bioresour Technol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil Microbiology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2022</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2022 Feb</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">345</style></volume><pages><style face="normal" font="default" size="100%">126553</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Electrotrophy, the growth of microbes on extracellular electron donors, drives important biogeochemical cycles and has practical applications. Studies of Fe(II)-based electrotrophy have provided foundational cytochrome-based mechanistic models for electron transport into cells. Direct electron uptake from other microbial species, Fe(0), or cathodes is of intense interest due to its potential roles in the production and anaerobic oxidation of methane, corrosion, and bioelectrochemical technologies. Other cells or Fe(0) can serve as the sole electron donor supporting the growth of several Geobacter and methanogen strains that are unable to use H as an electron donor, providing strong evidence for electrotrophy. Additional evidence for electrotrophy in Geobacter strains and Methanosarcina acetivorans is a requirement for outer-surface c-type cytochromes. However, in most instances claims for electrotrophy in anaerobes are based on indirect inference and the possibility that H is actually the electron donor supporting growth has not been rigorously excluded.&lt;/p&gt;</style></abstract><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/34906705?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%">Liu, Xinying</style></author><author><style face="normal" font="default" size="100%">Walker, David J F</style></author><author><style face="normal" font="default" size="100%">Nonnenmann, Stephen S</style></author><author><style face="normal" font="default" size="100%">Sun, Dezhi</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%">Direct Observation of Electrically Conductive Pili Emanating from .</style></title><secondary-title><style face="normal" font="default" size="100%">mBio</style></secondary-title><alt-title><style face="normal" font="default" size="100%">mBio</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electric Conductivity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Escherichia coli</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Atomic Force</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021 Aug 31</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">e0220921</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Geobacter sulfurreducens is a model microbe for elucidating the mechanisms for extracellular electron transfer in several biogeochemical cycles, bioelectrochemical applications, and microbial metal corrosion. Multiple lines of evidence previously suggested that electrically conductive pili (e-pili) are an essential conduit for long-range extracellular electron transport in G. sulfurreducens. However, it has recently been reported that G. sulfurreducens does not express e-pili and that filaments comprised of multi-heme -type cytochromes are responsible for long-range electron transport. This possibility was directly investigated by examining cells, rather than filament preparations, with atomic force microscopy. Approximately 90% of the filaments emanating from wild-type cells had a diameter (3 nm) and conductance consistent with previous reports of e-pili harvested from G. sulfurreducens or heterologously expressed in Escherichia coli from the G. sulfurreducens pilin gene. The remaining 10% of filaments had a morphology consistent with filaments comprised of the -type cytochrome OmcS. A strain expressing a modified pilin gene designed to yield poorly conductive pili expressed 90% filaments with a 3-nm diameter, but greatly reduced conductance, further indicating that the 3-nm diameter conductive filaments in the wild-type strain were e-pili. A strain in which genes for five of the most abundant outer-surface -type cytochromes, including OmcS, were deleted yielded only 3-nm-diameter filaments with the same conductance as in the wild type. These results demonstrate that e-pili are the most abundant conductive filaments expressed by G. sulfurreducens, consistent with previous functional studies demonstrating the need for e-pili for long-range extracellular electron transfer.  Electroactive microbes have significant environmental impacts, as well as applications in bioenergy and bioremediation. The composition, function, and even existence of electrically conductive pili (e-pili) has been one of the most contentious areas of investigation in electromicrobiology, in part because e-pili offer a mechanism for long-range electron transport that does not involve the metal cofactors common in much of biological electron transport. This study demonstrates that e-pili are abundant filaments emanating from Geobacter sulfurreducens, which serves as a model for long-range extracellular electron transfer in direct interspecies electron transfer, dissimilatory metal reduction, microbe-electrode exchange, and corrosion caused by direct electron uptake from Fe(0). The methods described in this study provide a simple strategy for evaluating the distribution of conductive filaments throughout the microbial world with an approach that avoids artifactual production and/or enrichment of filaments that may not be physiologically relevant.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/34465020?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%">Liang, Dandan</style></author><author><style face="normal" font="default" size="100%">Liu, Xinying</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Smith, Jessica A</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Feng, Yujie</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%">Extracellular Electron Exchange Capabilities of  and .</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Sci Technol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ Sci Technol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Desulfovibrio</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021 Dec 07</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">55</style></volume><pages><style face="normal" font="default" size="100%">16195-16203</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microbial extracellular electron transfer plays an important role in diverse biogeochemical cycles, metal corrosion, bioelectrochemical technologies, and anaerobic digestion. Evaluation of electron uptake from pure Fe(0) and stainless steel indicated that, in contrast to previous speculation in the literature,  and  are not able to directly extract electrons from solid-phase electron-donating surfaces.  grew with Fe(III) as the electron acceptor, but  did not.  reduced Fe(III) oxide occluded within porous alginate beads, suggesting that it released a soluble electron shuttle to promote Fe(III) oxide reduction. Conductive atomic force microscopy revealed that the  pili are electrically conductive and the expression of a gene encoding an aromatics-rich putative pilin was upregulated during growth on Fe(III) oxide. The expression of genes for multi-heme -type cytochromes was not upregulated during growth with Fe(III) as the electron acceptor, and genes for a porin-cytochrome conduit across the outer membrane were not apparent in the genome. The results suggest that  has adopted a novel combination of strategies to enable extracellular electron transport, which may be of biogeochemical and technological significance.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">23</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/34748326?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%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Zhou, Jinjie</style></author><author><style face="normal" font="default" size="100%">Ueki, Toshiyuki</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor</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%">Mechanisms for Electron Uptake by Methanosarcina acetivorans during Direct Interspecies Electron Transfer.</style></title><secondary-title><style face="normal" font="default" size="100%">mBio</style></secondary-title><alt-title><style face="normal" font="default" size="100%">mBio</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Archaeal Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Methane</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanosarcina</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcriptome</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021 Oct 26</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">12</style></volume><pages><style face="normal" font="default" size="100%">e0234421</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Direct interspecies electron transfer (DIET) between bacteria and methanogenic archaea appears to be an important syntrophy in both natural and engineered methanogenic environments. However, the electrical connections on the outer surface of methanogens and the subsequent processing of electrons for carbon dioxide reduction to methane are poorly understood. Here, we report that the genetically tractable methanogen Methanosarcina acetivorans can grow via DIET in coculture with Geobacter metallireducens serving as the electron-donating partner. Comparison of gene expression patterns in  grown in coculture versus pure-culture growth on acetate revealed that transcripts for the outer-surface multiheme type cytochrome MmcA were higher during DIET-based growth. Deletion of  inhibited DIET. The high aromatic amino acid content of  archaellins suggests that they might assemble into electrically conductive archaella. A mutant that could not express archaella was deficient in DIET. However, this mutant grew in DIET-based coculture as well as the archaellum-expressing parental strain in the presence of granular activated carbon, which was previously shown to serve as a substitute for electrically conductive pili as a conduit for long-range interspecies electron transfer in other DIET-based cocultures. Transcriptomic data suggesting that the membrane-bound Rnf, Fpo, and HdrED complexes also play a role in DIET were incorporated into a charge-balanced model illustrating how electrons entering the cell through MmcA can yield energy to support growth from carbon dioxide reduction. The results are the first genetics-based functional demonstration of likely outer-surface electrical contacts for DIET in a methanogen.  The conversion of organic matter to methane plays an important role in the global carbon cycle and is an effective strategy for converting wastes to a useful biofuel. The reduction of carbon dioxide to methane accounts for approximately a third of the methane produced in anaerobic soils and sediments as well as waste digesters. Potential electron donors for carbon dioxide reduction are H or electrons derived from direct interspecies electron transfer (DIET) between bacteria and methanogens. Elucidating the relative importance of these electron donors has been difficult due to a lack of information on the electrical connections on the outer surfaces of methanogens and how they process the electrons received from DIET. Transcriptomic patterns and gene deletion phenotypes reported here provide insight into how a group of  organisms that play an important role in methane production in soils and sediments participate in DIET.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/34607451?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%">Tang, Hai-Yan</style></author><author><style face="normal" font="default" size="100%">Yang, Chuntian</style></author><author><style face="normal" font="default" size="100%">Ueki, Toshiyuki</style></author><author><style face="normal" font="default" size="100%">Pittman, Conor C</style></author><author><style face="normal" font="default" size="100%">Xu, Dake</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Gu, Tingyue</style></author><author><style face="normal" font="default" size="100%">Wang, Fuhui</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%">Stainless steel corrosion via direct iron-to-microbe electron transfer by Geobacter species.</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%">Corrosion</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Stainless Steel</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2021</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2021 Oct</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">15</style></volume><pages><style face="normal" font="default" size="100%">3084-3093</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microbial corrosion of iron-based materials is a substantial economic problem. A mechanistic understanding is required to develop mitigation strategies, but previous mechanistic studies have been limited to investigations with relatively pure Fe(0), which is not a common structural material. We report here that the mechanism for microbial corrosion of stainless steel, the metal of choice for many actual applications, can be significantly different from that for Fe(0). Although H is often an intermediary electron carrier between the metal and microbes during Fe(0) corrosion, we found that H is not abiotically produced from stainless steel, making this corrosion mechanism unlikely. Geobacter sulfurreducens and Geobacter metallireducens, electrotrophs that are known to directly accept electrons from other microbes or electrodes, extracted electrons from stainless steel via direct iron-to-microbe electron transfer. Genetic modification to prevent H consumption did not negatively impact on stainless steel corrosion. Corrosion was inhibited when genes for outer-surface cytochromes that are key electrical contacts were deleted. These results indicate that a common model of microbial Fe(0) corrosion by hydrogenase-positive microbes, in which H serves as an intermediary electron carrier between the metal surface and the microbe, may not apply to the microbial corrosion of stainless steel. However, direct iron-to-microbe electron transfer is a feasible route for stainless steel corrosion.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/33972726?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%">Zheng, Shiling</style></author><author><style face="normal" font="default" size="100%">Liu, Fanghua</style></author><author><style face="normal" font="default" size="100%">Wang, Bingchen</style></author><author><style face="normal" font="default" size="100%">Zhang, Yuechao</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%"> Capable of Direct Interspecies Electron Transfer.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Sci Technol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ Sci Technol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Methane</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanobacterium</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2020 Dec 01</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">54</style></volume><pages><style face="normal" font="default" size="100%">15347-15354</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Direct interspecies electron transfer (DIET) from bacteria to methanogens is a revolutionary concept for syntrophic metabolism in methanogenic soils/sediments and anaerobic digestion. Previous studies have indicated that the potential for DIET is limited to methanogens in the , leading to the assumption that an abundance of other types of methanogens, such as  species, indicates a lack of DIET. We report here on a strain of , designated strain YSL, that grows via DIET in defined cocultures with . The cocultures formed aggregates, in which cells of strain YSL and  were uniformly dispersed throughout. This close association of the two species is the likely explanation for the ability of a strain of  that could not express electrically conductive pili to grow in coculture with strain YSL. Granular activated carbon promoted the initial formation of the DIET-based cocultures. The discovery of DIET in , the genus of methanogens that has been the exemplar for interspecies electron transfer  H, suggests that the capacity for DIET is much more broadly distributed among methanogens than previously considered. More innovative approaches to microbial isolation and characterization are needed in order to better understand how methanogenic communities function.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">23</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/33205658?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%">Walker, David J F</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Rotaru, Amelia-Elena</style></author><author><style face="normal" font="default" size="100%">Ward, Joy E</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Zhu, Jiaxin</style></author><author><style face="normal" font="default" size="100%">Ueki, Toshiyuki</style></author><author><style face="normal" font="default" size="100%">Nonnenmann, Stephen S</style></author><author><style face="normal" font="default" size="100%">McInerney, Michael J</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%">Syntrophus conductive pili demonstrate that common hydrogen-donating syntrophs can have a direct electron transfer option.</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%">Deltaproteobacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Electric Conductivity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Formates</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2020 Mar</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">14</style></volume><pages><style face="normal" font="default" size="100%">837-846</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Syntrophic interspecies electron exchange is essential for the stable functioning of diverse anaerobic microbial communities. Hydrogen/formate interspecies electron transfer (HFIT), in which H and/or formate function as diffusible electron carriers, has been considered to be the primary mechanism for electron transfer because most common syntrophs were thought to lack biochemical components, such as electrically conductive pili (e-pili), necessary for direct interspecies electron transfer (DIET). Here we report that Syntrophus aciditrophicus, one of the most intensively studied microbial models for HFIT, produces e-pili and can grow via DIET. Heterologous expression of the putative S. aciditrophicus type IV pilin gene in Geobacter sulfurreducens yielded conductive pili of the same diameter (4 nm) and conductance of the native S. aciditrophicus pili and enabled long-range electron transport in G. sulfurreducens. S. aciditrophicus lacked abundant c-type cytochromes often associated with DIET. Pilin genes likely to yield e-pili were found in other genera of hydrogen/formate-producing syntrophs. The finding that DIET is a likely option for diverse syntrophs that are abundant in many anaerobic environments necessitates a reexamination of the paradigm that HFIT is the predominant mechanism for syntrophic electron exchange within anaerobic microbial communities of biogeochemical and practical significance.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/31896792?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%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Ueki, Toshiyuki</style></author><author><style face="normal" font="default" size="100%">Tang, Hai-Yan</style></author><author><style face="normal" font="default" size="100%">Zhou, Jinjie</style></author><author><style face="normal" font="default" size="100%">Smith, Jessica A</style></author><author><style face="normal" font="default" size="100%">Chaput, Gina</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%">A Membrane-Bound Cytochrome Enables  To Conserve Energy from Extracellular Electron Transfer.</style></title><secondary-title><style face="normal" font="default" size="100%">mBio</style></secondary-title><alt-title><style face="normal" font="default" size="100%">mBio</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetates</style></keyword><keyword><style  face="normal" font="default" size="100%">Anthraquinones</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Archaeal</style></keyword><keyword><style  face="normal" font="default" size="100%">Gram-Negative Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Membranes</style></keyword><keyword><style  face="normal" font="default" size="100%">Mesna</style></keyword><keyword><style  face="normal" font="default" size="100%">Methane</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanol</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanosarcina</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidoreductases</style></keyword><keyword><style  face="normal" font="default" size="100%">Transcriptome</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2019</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2019 Aug 20</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">10</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Extracellular electron exchange in  species and closely related  plays an important role in the global carbon cycle and enhances the speed and stability of anaerobic digestion by facilitating efficient syntrophic interactions. Here, we grew  with methanol provided as the electron donor and the humic analogue, anthraquione-2,6-disulfonate (AQDS), provided as the electron acceptor when methane production was inhibited with bromoethanesulfonate. AQDS was reduced with simultaneous methane production in the absence of bromoethanesulfonate. Transcriptomics revealed that expression of the gene for the transmembrane, multiheme, -type cytochrome MmcA was higher in AQDS-respiring cells than in cells performing methylotrophic methanogenesis. A strain in which the gene for MmcA was deleted failed to grow via AQDS reduction but grew with the conversion of methanol or acetate to methane, suggesting that MmcA has a specialized role as a conduit for extracellular electron transfer. Enhanced expression of genes for methanol conversion to methyl-coenzyme M and the Rnf complex suggested that methanol is oxidized to carbon dioxide in AQDS-respiring cells through a pathway that is similar to methyl-coenzyme M oxidation in methanogenic cells. However, during AQDS respiration the Rnf complex and reduced methanophenazine probably transfer electrons to MmcA, which functions as the terminal reductase for AQDS reduction. Extracellular electron transfer may enable the survival of methanogens in dynamic environments in which oxidized humic substances and Fe(III) oxides are intermittently available. The availability of tools for genetic manipulation of  makes it an excellent model microbe for evaluating -type cytochrome-dependent extracellular electron transfer in  The discovery of a methanogen that can conserve energy to support growth solely from the oxidation of organic carbon coupled to the reduction of an extracellular electron acceptor expands the possible environments in which methanogens might thrive. The potential importance of -type cytochromes for extracellular electron transfer to syntrophic bacterial partners and/or Fe(III) minerals in some  was previously proposed, but these studies with  provide the first genetic evidence for cytochrome-based extracellular electron transfer in  The results suggest parallels with Gram-negative bacteria, such as  and  species, in which multiheme outer-surface -type cytochromes are an essential component for electrical communication with the extracellular environment.  offers an unprecedented opportunity to study mechanisms for energy conservation from the anaerobic oxidation of one-carbon organic compounds coupled to extracellular electron transfer in  with implications not only for methanogens but possibly also for  that anaerobically oxidize methane.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/31431545?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%">Liu, Fanghua</style></author><author><style face="normal" font="default" size="100%">Rotaru, Amelia-Elena</style></author><author><style face="normal" font="default" size="100%">Shrestha, Pravin M</style></author><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</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%">Magnetite compensates for the lack of a pilin-associated c-type cytochrome in extracellular electron exchange.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ Microbiol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferrosoferric Oxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression Regulation, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Heme</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxides</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015 Mar</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">648-55</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Nanoscale magnetite can facilitate microbial extracellular electron transfer that plays an important role in biogeochemical cycles, bioremediation and several bioenergy strategies, but the mechanisms for the stimulation of extracellular electron transfer are poorly understood. Further investigation revealed that magnetite attached to the electrically conductive pili of Geobacter species in a manner reminiscent of the association of the multi-heme c-type cytochrome OmcS with the pili of Geobacter sulfurreducens. Magnetite conferred extracellular electron capabilities on an OmcS-deficient strain unable to participate in interspecies electron transfer or Fe(III) oxide reduction. In the presence of magnetite wild-type cells repressed expression of the OmcS gene, suggesting that cells might need to produce less OmcS when magnetite was available. The finding that magnetite can compensate for the lack of the electron transfer functions of a multi-heme c-type cytochrome has implications not only for the function of modern microbes, but also for the early evolution of microbial electron transport mechanisms.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/24725505?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%">Lovley, Derek R</style></author><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Seeing is believing: novel imaging techniques help clarify microbial nanowire structure and function.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ Microbiol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cytochromes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electric Conductivity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Atomic Force</style></keyword><keyword><style  face="normal" font="default" size="100%">Nanowires</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxides</style></keyword><keyword><style  face="normal" font="default" size="100%">Periplasm</style></keyword><keyword><style  face="normal" font="default" size="100%">Shewanella</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2015</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2015 Jul</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">17</style></volume><pages><style face="normal" font="default" size="100%">2209-15</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Novel imaging approaches have recently helped to clarify the properties of 'microbial nanowires'. Geobacter sulfurreducens pili are actual wires. They possess metallic-like conductivity, which can be attributed to overlapping pi-pi orbitals of key aromatic amino acids. Electrostatic force microscopy recently confirmed charge propagation along the pili, in a manner similar to carbon nanotubes. The pili are essential for long-range electron transport to insoluble electron acceptors and interspecies electron transfer. Previous claims that Shewanella oneidensis also produce conductive pili have recently been recanted, based on novel live-imaging studies. The putative pili are, in fact, long extensions of the cytochrome-rich outer membrane and periplasm that, when dried, collapse to form filaments with dimensions similar to pili. It has yet to be demonstrated whether the cytochrome-to-cytochrome electron hopping documented in the dried membrane extensions takes place in intact hydrated membrane extensions or whether the membrane extensions enhance electron transport to insoluble electron acceptors such as Fe(III) oxides or electrodes. These findings demonstrate that G. sulfurreducens conductive pili and the outer membrane extensions of S. oneidensis are fundamentally different in composition, mechanism of electron transport and physiological role. New methods for evaluating filament conductivity will facilitate screening the microbial world for nanowires and elucidating their function.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/25384844?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%">Malvankar, Nikhil S</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%">Microbial nanowires for bioenergy applications.</style></title><secondary-title><style face="normal" font="default" size="100%">Curr Opin Biotechnol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Curr Opin Biotechnol</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Bioelectric Energy Sources</style></keyword><keyword><style  face="normal" font="default" size="100%">Biofilms</style></keyword><keyword><style  face="normal" font="default" size="100%">Electric Conductivity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electricity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Methane</style></keyword><keyword><style  face="normal" font="default" size="100%">Nanowires</style></keyword><keyword><style  face="normal" font="default" size="100%">Shewanella</style></keyword><keyword><style  face="normal" font="default" size="100%">Synthetic Biology</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2014 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">27</style></volume><pages><style face="normal" font="default" size="100%">88-95</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Microbial nanowires are electrically conductive filaments that facilitate long-range extracellular electron transfer. The model for electron transport along Shewanella oneidensis nanowires is electron hopping/tunneling between cytochromes adorning the filaments. Geobacter sulfurreducens nanowires are comprised of pili that have metal-like conductivity attributed to overlapping pi-pi orbitals of aromatic amino acids. The nanowires of Geobacter species have been implicated in direct interspecies electron transfer (DIET), which may be an important mode of syntrophy in the conversion of organic wastes to methane. Nanowire networks confer conductivity to Geobacter biofilms converting organic compounds to electricity in microbial fuel cells (MFCs) and increasing nanowire production is the only genetic manipulation shown to yield strains with improved current-producing capabilities. Introducing nanowires, or nanowire mimetics, might improve other bioenergy strategies that rely on extracellular electron exchange, such as microbial electrosynthesis. Similarities between microbial nanowires and synthetic conducting polymers suggest additional energy-related applications.&lt;/p&gt;</style></abstract><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/24863901?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%">Chen, Shanshan</style></author><author><style face="normal" font="default" size="100%">Rotaru, Amelia-Elena</style></author><author><style face="normal" font="default" size="100%">Shrestha, Pravin Malla</style></author><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</style></author><author><style face="normal" font="default" size="100%">Liu, Fanghua</style></author><author><style face="normal" font="default" size="100%">Fan, Wei</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</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%">Promoting interspecies electron transfer with biochar.</style></title><secondary-title><style face="normal" font="default" size="100%">Sci Rep</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Sci Rep</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Charcoal</style></keyword><keyword><style  face="normal" font="default" size="100%">Coculture Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ethanol</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Methanosarcina barkeri</style></keyword><keyword><style  face="normal" font="default" size="100%">Soil</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2014</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2014 May 21</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">4</style></volume><pages><style face="normal" font="default" size="100%">5019</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Biochar, a charcoal-like product of the incomplete combustion of organic materials, is an increasingly popular soil amendment designed to improve soil fertility. We investigated the possibility that biochar could promote direct interspecies electron transfer (DIET) in a manner similar to that previously reported for granular activated carbon (GAC). Although the biochars investigated were 1000 times less conductive than GAC, they stimulated DIET in co-cultures of Geobacter metallireducens with Geobacter sulfurreducens or Methanosarcina barkeri in which ethanol was the electron donor. Cells were attached to the biochar, yet not in close contact, suggesting that electrons were likely conducted through the biochar, rather than biological electrical connections. The finding that biochar can stimulate DIET may be an important consideration when amending soils with biochar and can help explain why biochar may enhance methane production from organic wastes under anaerobic conditions.&lt;/p&gt;</style></abstract><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/24846283?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%">Shrestha, Pravin Malla</style></author><author><style face="normal" font="default" size="100%">Rotaru, Amelia-Elena</style></author><author><style face="normal" font="default" size="100%">Aklujkar, Muktak</style></author><author><style face="normal" font="default" size="100%">Liu, Fanghua</style></author><author><style face="normal" font="default" size="100%">Shrestha, Minita</style></author><author><style face="normal" font="default" size="100%">Summers, Zarath M</style></author><author><style face="normal" font="default" size="100%">Malvankar, Nikhil</style></author><author><style face="normal" font="default" size="100%">Flores, Dan Carlo</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%">Syntrophic growth with direct interspecies electron transfer as the primary mechanism for energy exchange.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Microbiol Rep</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ Microbiol Rep</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetates</style></keyword><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Citrate (si)-Synthase</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Energy Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Ethanol</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Formate Dehydrogenases</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2013</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2013 Dec</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">5</style></volume><pages><style face="normal" font="default" size="100%">904-10</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Direct interspecies electron transfer (DIET) through biological electrical connections is an alternative to interspecies H2 transfer as a mechanism for electron exchange in syntrophic cultures. However, it has not previously been determined whether electrons received via DIET yield energy to support cell growth. In order to investigate this, co-cultures of Geobacter metallireducens, which can transfer electrons to wild-type G. sulfurreducens via DIET, were established with a citrate synthase-deficient G. sulfurreducens strain that can receive electrons for respiration through DIET only. In a medium with ethanol as the electron donor and fumarate as the electron acceptor, co-cultures with the citrate synthase-deficient G. sulfurreducens strain metabolized ethanol as fast as co-cultures with wild-type, but the acetate that G. metallireducens generated from ethanol oxidation accumulated. The lack of acetate metabolism resulted in less fumarate reduction and lower cell abundance of G. sulfurreducens. RNAseq analysis of transcript abundance was consistent with a lack of acetate metabolism in G. sulfurreducens and revealed gene expression levels for the uptake hydrogenase, formate dehydrogenase, the pilus-associated c-type cytochrome OmcS and pili consistent with electron transfer via DIET. These results suggest that electrons transferred via DIET can serve as the sole energy source to support anaerobic respiration.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/24249299?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%">Rotaru, Amelia-Elena</style></author><author><style face="normal" font="default" size="100%">Shrestha, Pravin M</style></author><author><style face="normal" font="default" size="100%">Liu, Fanghua</style></author><author><style face="normal" font="default" size="100%">Ueki, Toshiyuki</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly</style></author><author><style face="normal" font="default" size="100%">Summers, Zarath M</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%">Interspecies electron transfer via hydrogen and formate rather than direct electrical connections in cocultures of Pelobacter carbinolicus and Geobacter sulfurreducens.</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%">Coculture Techniques</style></keyword><keyword><style  face="normal" font="default" size="100%">Deltaproteobacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Electricity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Formates</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%">Microbial Interactions</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012 Nov</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">78</style></volume><pages><style face="normal" font="default" size="100%">7645-51</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Direct interspecies electron transfer (DIET) is an alternative to interspecies H(2)/formate transfer as a mechanism for microbial species to cooperatively exchange electrons during syntrophic metabolism. To understand what specific properties contribute to DIET, studies were conducted with Pelobacter carbinolicus, a close relative of Geobacter metallireducens, which is capable of DIET. P. carbinolicus grew in coculture with Geobacter sulfurreducens with ethanol as the electron donor and fumarate as the electron acceptor, conditions under which G. sulfurreducens formed direct electrical connections with G. metallireducens. In contrast to the cell aggregation associated with DIET, P. carbinolicus and G. sulfurreducens did not aggregate. Attempts to initiate cocultures with a genetically modified strain of G. sulfurreducens incapable of both H(2) and formate utilization were unsuccessful, whereas cocultures readily grew with mutant strains capable of formate but not H(2) uptake or vice versa. The hydrogenase mutant of G. sulfurreducens compensated, in cocultures, with significantly increased formate dehydrogenase gene expression. In contrast, the transcript abundance of a hydrogenase gene was comparable in cocultures with that for the formate dehydrogenase mutant of G. sulfurreducens or the wild type, suggesting that H(2) was the primary electron carrier in the wild-type cocultures. Cocultures were also initiated with strains of G. sulfurreducens that could not produce pili or OmcS, two essential components for DIET. The finding that P. carbinolicus exchanged electrons with G. sulfurreducens via interspecies transfer of H(2)/formate rather than DIET demonstrates that not all microorganisms that can grow syntrophically are capable of DIET and that closely related microorganisms may use significantly different strategies for interspecies electron exchange.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">21</style></issue><custom1><style face="normal" font="default" size="100%">https://www.ncbi.nlm.nih.gov/pubmed/22923399?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%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Hensley, Sarah A</style></author><author><style face="normal" font="default" size="100%">Franks, Ashley E</style></author><author><style face="normal" font="default" size="100%">Summers, Zarath M</style></author><author><style face="normal" font="default" size="100%">Ou, Jianhong</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Snoeyenbos-West, Oona L</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%">Electrosynthesis of organic compounds from carbon dioxide is catalyzed by a diversity of acetogenic microorganisms.</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%">Acetobacterium</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Clostridium</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Moorella</style></keyword><keyword><style  face="normal" font="default" size="100%">Organic Chemicals</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Veillonellaceae</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">77</style></volume><pages><style face="normal" font="default" size="100%">2882-6</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Microbial electrosynthesis, a process in which microorganisms use electrons derived from electrodes to reduce carbon dioxide to multicarbon, extracellular organic compounds, is a potential strategy for capturing electrical energy in carbon-carbon bonds of readily stored and easily distributed products, such as transportation fuels. To date, only one organism, the acetogen Sporomusa ovata, has been shown to be capable of electrosynthesis. The purpose of this study was to determine if a wider range of microorganisms is capable of this process. Several other acetogenic bacteria, including two other Sporomusa species, Clostridium ljungdahlii, Clostridium aceticum, and Moorella thermoacetica, consumed current with the production of organic acids. In general acetate was the primary product, but 2-oxobutyrate and formate also were formed, with 2-oxobutyrate being the predominant identified product of electrosynthesis by C. aceticum. S. sphaeroides, C. ljungdahlii, and M. thermoacetica had high (&gt;80%) efficiencies of electrons consumed and recovered in identified products. The acetogen Acetobacterium woodii was unable to consume current. These results expand the known range of microorganisms capable of electrosynthesis, providing multiple options for the further optimization of this process.</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21378039?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%">Strycharz, Sarah M</style></author><author><style face="normal" font="default" size="100%">Glaven, Richard H</style></author><author><style face="normal" font="default" size="100%">Coppi, Maddalena V</style></author><author><style face="normal" font="default" size="100%">Gannon, Sarah M</style></author><author><style face="normal" font="default" size="100%">Perpetua, Lorrie A</style></author><author><style face="normal" font="default" size="100%">Liu, Anna</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</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%">Gene expression and deletion analysis of mechanisms for electron transfer from electrodes to Geobacter sulfurreducens.</style></title><secondary-title><style face="normal" font="default" size="100%">Bioelectrochemistry</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Bioelectrochemistry</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Biofilms</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochromes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Gene Expression</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Graphite</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%">Sequence Deletion</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Feb</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">80</style></volume><pages><style face="normal" font="default" size="100%">142-50</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Geobacter sulfurreducens is one of the few microorganisms available in pure culture known to directly accept electrons from a negatively poised electrode. Microarray analysis was used to compare gene transcript abundance in biofilms of G. sulfurreducens using a graphite electrode as the sole electron donor for fumarate reduction compared with transcript abundance in biofilms growing on the same material, but not consuming current. Surprisingly, genes for putative cell-electrode connections, such as outer-surface cytochromes and pili, which are highly expressed in current-producing biofilms, were not highly expressed in current-consuming biofilms. Microarray analysis of G. sulfurreducens gene transcript abundance in current-consuming biofilms versus current-producing biofilms gave similar results. In both comparative studies current-consuming biofilms had greater transcript abundance for a gene (GSU3274) encoding a putative monoheme, c-type cytochrome. Deletion of genes for outer-surface proteins previously shown to be essential for optimal electron transfer to electrodes had no impact on electron transfer from electrodes. Deletion of GSU3274 completely inhibited electron transfer from electrodes, but had no impact on electron transfer to electrodes. These differences in gene expression patterns and the impact of gene deletions suggest that the mechanisms for electron transfer from electrodes to G. sulfurreducens differ significantly from the mechanisms for electron transfer to electrodes.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20696622?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%">Lovley, Derek R</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">A shift in the current: new applications and concepts for microbe-electrode electron exchange.</style></title><secondary-title><style face="normal" font="default" size="100%">Curr Opin Biotechnol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Curr. Opin. Biotechnol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation, Environmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Biofuels</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Electricity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Environmental Pollutants</style></keyword><keyword><style  face="normal" font="default" size="100%">Fungi</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbiological Phenomena</style></keyword><keyword><style  face="normal" font="default" size="100%">Organic Chemicals</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2011</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2011 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">22</style></volume><pages><style face="normal" font="default" size="100%">441-8</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Perceived applications of microbe-electrode interactions are shifting from production of electric power to other technologies, some of which even consume current. Electrodes can serve as stable, long-term electron acceptors for contaminant-degrading microbes to promote rapid degradation of organic pollutants in anaerobic subsurface environments. Solar and other forms of renewable electrical energy can be used to provide electrons extracted from water to microorganisms on electrodes at suitably low potentials for a number of groundwater bioremediation applications as well as for the production of fuels and other organic compounds from carbon dioxide. The understanding of how microorganisms exchange electrons with electrodes has improved substantially and is expected to be helpful in optimizing practical applications of microbe-electrode interactions, as well as yielding insights into related natural environmental phenomena.</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21333524?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%">Summers, Zarath M</style></author><author><style face="normal" font="default" size="100%">Fogarty, Heather E</style></author><author><style face="normal" font="default" size="100%">Leang, Ching</style></author><author><style face="normal" font="default" size="100%">Franks, Ashley E</style></author><author><style face="normal" font="default" size="100%">Malvankar, Nikhil S</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%">Direct exchange of electrons within aggregates of an evolved syntrophic coculture of anaerobic bacteria.</style></title><secondary-title><style face="normal" font="default" size="100%">Science</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Science</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%">Biological Evolution</style></keyword><keyword><style  face="normal" font="default" size="100%">Culture Media</style></keyword><keyword><style  face="normal" font="default" size="100%">Cytochrome c Group</style></keyword><keyword><style  face="normal" font="default" size="100%">Electron Transport</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ethanol</style></keyword><keyword><style  face="normal" font="default" size="100%">Fimbriae Proteins</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%">Microbial Consortia</style></keyword><keyword><style  face="normal" font="default" size="100%">Microbial Interactions</style></keyword><keyword><style  face="normal" font="default" size="100%">Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Selection, Genetic</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010 Dec 3</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">330</style></volume><pages><style face="normal" font="default" size="100%">1413-5</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Microbial consortia that cooperatively exchange electrons play a key role in the anaerobic processing of organic matter. Interspecies hydrogen transfer is a well-documented strategy for electron exchange in dispersed laboratory cultures, but cooperative partners in natural environments often form multispecies aggregates. We found that laboratory evolution of a coculture of Geobacter metallireducens and Geobacter sulfurreducens metabolizing ethanol favored the formation of aggregates that were electrically conductive. Sequencing aggregate DNA revealed selection for a mutation that enhances the production of a c-type cytochrome involved in extracellular electron transfer and accelerates the formation of aggregates. Aggregate formation was also much faster in mutants that were deficient in interspecies hydrogen transfer, further suggesting direct interspecies electron transfer.</style></abstract><issue><style face="normal" font="default" size="100%">6009</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21127257?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%">Aklujkar, Muktak</style></author><author><style face="normal" font="default" size="100%">Young, Nelson D</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn</style></author><author><style face="normal" font="default" size="100%">Chavan, Milind</style></author><author><style face="normal" font="default" size="100%">Risso, Carla</style></author><author><style face="normal" font="default" size="100%">Kiss, Hajnalka E</style></author><author><style face="normal" font="default" size="100%">Han, Cliff S</style></author><author><style face="normal" font="default" size="100%">Land, Miriam L</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%">The genome of Geobacter bemidjiensis, exemplar for the subsurface clade of Geobacter species that predominate in Fe(III)-reducing subsurface environments.</style></title><secondary-title><style face="normal" font="default" size="100%">BMC Genomics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">BMC Genomics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Aldehyde Oxidoreductases</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation, Environmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbohydrate Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Wall</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Environmental Microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Fatty Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Frameshift Mutation</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Genes, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Genome, Bacterial</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Glucose</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Metabolic Networks and Pathways</style></keyword><keyword><style  face="normal" font="default" size="100%">Multienzyme Complexes</style></keyword><keyword><style  face="normal" font="default" size="100%">Multigene Family</style></keyword><keyword><style  face="normal" font="default" size="100%">Osmosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxo-Acid-Lyases</style></keyword><keyword><style  face="normal" font="default" size="100%">Propionic Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Pyruvic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Species Specificity</style></keyword><keyword><style  face="normal" font="default" size="100%">Surface Properties</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">490</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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.</style></abstract><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/20828392?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%">Yang, Tae Hoon</style></author><author><style face="normal" font="default" size="100%">Coppi, Maddalena V</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author><author><style face="normal" font="default" size="100%">Sun, Jun</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Metabolic response of Geobacter sulfurreducens towards electron donor/acceptor variation.</style></title><secondary-title><style face="normal" font="default" size="100%">Microb Cell Fact</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Microb. Cell Fact.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Acetic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Acetyl Coenzyme A</style></keyword><keyword><style  face="normal" font="default" size="100%">Amino Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Isotopes</style></keyword><keyword><style  face="normal" font="default" size="100%">Citric Acid Cycle</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</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%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Gluconeogenesis</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Phosphoenolpyruvate Carboxykinase (GTP)</style></keyword><keyword><style  face="normal" font="default" size="100%">Pyruvates</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2010</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">9</style></volume><pages><style face="normal" font="default" size="100%">90</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">BACKGROUND: Geobacter sulfurreducens is capable of coupling the complete oxidation of organic compounds to iron reduction. The metabolic response of G. sulfurreducens towards variations in electron donors (acetate, hydrogen) and acceptors (Fe(III), fumarate) was investigated via (13)C-based metabolic flux analysis. We examined the (13)C-labeling patterns of proteinogenic amino acids obtained from G. sulfurreducens cultured with (13)C-acetate.

RESULTS: Using (13)C-based metabolic flux analysis, we observed that donor and acceptor variations gave rise to differences in gluconeogenetic initiation, tricarboxylic acid cycle activity, and amino acid biosynthesis pathways. Culturing G. sulfurreducens cells with Fe(III) as the electron acceptor and acetate as the electron donor resulted in pyruvate as the primary carbon source for gluconeogenesis. When fumarate was provided as the electron acceptor and acetate as the electron donor, the flux analysis suggested that fumarate served as both an electron acceptor and, in conjunction with acetate, a carbon source. Growth on fumarate and acetate resulted in the initiation of gluconeogenesis by phosphoenolpyruvate carboxykinase and a slightly elevated flux through the oxidative tricarboxylic acid cycle as compared to growth with Fe(III) as the electron acceptor. In addition, the direction of net flux between acetyl-CoA and pyruvate was reversed during growth on fumarate relative to Fe(III), while growth in the presence of Fe(III) and acetate which provided hydrogen as an electron donor, resulted in decreased flux through the tricarboxylic acid cycle.

CONCLUSIONS: We gained detailed insight into the metabolism of G. sulfurreducens cells under various electron donor/acceptor conditions using (13)C-based metabolic flux analysis. Our results can be used for the development of G. sulfurreducens as a chassis for a variety of applications including bioremediation and renewable biofuel production.</style></abstract><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/21092215?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%">Hedrick, D B</style></author><author><style face="normal" font="default" size="100%">Peacock, A D</style></author><author><style face="normal" font="default" size="100%">Lovley, D R</style></author><author><style face="normal" font="default" size="100%">Woodard, T L</style></author><author><style face="normal" font="default" size="100%">Nevin, K P</style></author><author><style face="normal" font="default" size="100%">Long, P E</style></author><author><style face="normal" font="default" size="100%">White, D C</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Polar lipid fatty acids, LPS-hydroxy fatty acids, and respiratory quinones of three Geobacter strains, and variation with electron acceptor.</style></title><secondary-title><style face="normal" font="default" size="100%">J Ind Microbiol Biotechnol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Ind. Microbiol. Biotechnol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Culture Media</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Environmental Microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">Fatty Acids</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferrous Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipids</style></keyword><keyword><style  face="normal" font="default" size="100%">Lipopolysaccharides</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrates</style></keyword><keyword><style  face="normal" font="default" size="100%">Quinones</style></keyword><keyword><style  face="normal" font="default" size="100%">Vitamin K 2</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 Feb</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">36</style></volume><pages><style face="normal" font="default" size="100%">205-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The polar lipid fatty acids, lipopolysaccharide hydroxy-fatty acids, and respiratory quinones of Geobacter metallireducens str. GS-15, Geobacter sulfurreducens str. PCA, and Geobacter bemidjiensis str. Bem are reported. Also, the lipids of G. metallireducens were compared when grown with Fe(3+) or nitrate as electron acceptors and G. sulfurreducens with Fe(3+) or fumarate. In all experiments, the most abundant polar lipid fatty acids were 14:0, i15:0, 16:1 omega 7c, 16:1 omega 5c, and 16:0; lipopolysaccharide hydroxy-fatty acids were dominated by 3oh16:0, 3oh14:0, 9oh16:0, and 10oh16:0; and menaquinone-8 was the most abundant respiratory quinone. Some variation in lipid profiles with strain were observed, but not with electron acceptor.</style></abstract><issue><style face="normal" font="default" size="100%">2</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18846396?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%">Richter, Hanno</style></author><author><style face="normal" font="default" size="100%">McCarthy, Kevin</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Johnson, Jessica P</style></author><author><style face="normal" font="default" size="100%">Rotello, Vincent M</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%">Electricity generation by Geobacter sulfurreducens attached to gold electrodes.</style></title><secondary-title><style face="normal" font="default" size="100%">Langmuir</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Langmuir</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Gold</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Confocal</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Electron, Scanning</style></keyword><keyword><style  face="normal" font="default" size="100%">Surface Properties</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 Apr 15</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">24</style></volume><pages><style face="normal" font="default" size="100%">4376-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The versatility of gold for electrode manufacture suggests that it could be an ideal material for some microbial fuel cell applications. However, previous studies have suggested that microorganisms that readily transfer electrons to graphite do not transfer electrons to gold. Investigations with Geobacter sulfurreducens demonstrated that it could grow on gold anodes producing current nearly as effectively as with graphite anodes. Current production was associated with the development of G. sulfurreducens biofilms up to 40 microm thick. No current was produced if pilA, the gene for the structural protein of the conductive pili of G. sulfurreducens, was deleted. The finding that gold is a suitable anode material for microbial fuel cells offers expanded possibilities for the construction of microbial fuel cells and the electrochemical analysis of microbe-electrode interactions.</style></abstract><issue><style face="normal" font="default" size="100%">8</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18303924?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%">Strycharz, Sarah M</style></author><author><style face="normal" font="default" size="100%">Woodard, Trevor L</style></author><author><style face="normal" font="default" size="100%">Johnson, Jessica P</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Sanford, Robert A</style></author><author><style face="normal" font="default" size="100%">Löffler, Frank E</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%">Graphite electrode as a sole electron donor for reductive dechlorination of tetrachlorethene by Geobacter lovleyi.</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%">Acetic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Biofilms</style></keyword><keyword><style  face="normal" font="default" size="100%">Biomass</style></keyword><keyword><style  face="normal" font="default" size="100%">Electricity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ethylene Dichlorides</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Graphite</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Electron, Scanning</style></keyword><keyword><style  face="normal" font="default" size="100%">Succinic Acid</style></keyword><keyword><style  face="normal" font="default" size="100%">Tetrachloroethylene</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 Oct</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">5943-7</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The possibility that graphite electrodes can serve as the direct electron donor for microbially catalyzed reductive dechlorination was investigated with Geobacter lovleyi. In an initial evaluation of whether G. lovleyi could interact electronically with graphite electrodes, cells were provided with acetate as the electron donor and an electrode as the sole electron acceptor. Current was produced at levels that were ca. 10-fold lower than those previously reported for Geobacter sulfurreducens under similar conditions, and G. lovleyi anode biofilms were correspondingly thinner. When an electrode poised at -300 mV (versus a standard hydrogen electrode) was provided as the electron donor, G. lovleyi effectively reduced fumarate to succinate. The stoichiometry of electrons consumed to succinate produced was 2:1, the ratio expected if the electrode served as the sole electron donor for fumarate reduction. G. lovleyi effectively reduced tetrachloroethene (PCE) to cis-dichloroethene with a poised electrode as the sole electron donor at rates comparable to those obtained when acetate serves as the electron donor. Cells were less abundant on the electrodes when the electrodes served as an electron donor than when they served as an electron acceptor. PCE was not reduced in controls without cells or when the current supply to cells was interrupted. These results demonstrate that G. lovleyi can use a poised electrode as a direct electron donor for reductive dechlorination of PCE. The ability to colocalize dechlorinating microorganisms with electrodes has several potential advantages for bioremediation of subsurface chlorinated contaminants, especially in source zones where electron donor delivery is challenging and often limits dechlorination.</style></abstract><issue><style face="normal" font="default" size="100%">19</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/18658278?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%">Ahrendt, Angela J</style></author><author><style face="normal" font="default" size="100%">Tollaksen, Sandra L</style></author><author><style face="normal" font="default" size="100%">Lindberg, Carl</style></author><author><style face="normal" font="default" size="100%">Zhu, Wenhong</style></author><author><style face="normal" font="default" size="100%">Yates, John R</style></author><author><style face="normal" font="default" size="100%">Nevin, Kelly P</style></author><author><style face="normal" font="default" size="100%">Babnigg, György</style></author><author><style face="normal" font="default" size="100%">Lovley, Derek R</style></author><author><style face="normal" font="default" size="100%">Giometti, Carol S</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Steady state protein levels in Geobacter metallireducens grown with iron (III) citrate or nitrate as terminal electron acceptor.</style></title><secondary-title><style face="normal" font="default" size="100%">Proteomics</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Proteomics</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Bacterial Proteins</style></keyword><keyword><style  face="normal" font="default" size="100%">Cell Proliferation</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrophoresis, Gel, Two-Dimensional</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Hydrogen-Ion Concentration</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrates</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Proteomics</style></keyword><keyword><style  face="normal" font="default" size="100%">Tandem Mass Spectrometry</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 Nov</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">7</style></volume><pages><style face="normal" font="default" size="100%">4148-57</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Geobacter species predominate in aquatic sediments and submerged soils where organic carbon sources are oxidized with the reduction of Fe(III). The natural occurrence of Geobacter in some waste sites suggests this microorganism could be useful for bioremediation if growth and metabolic activity can be regulated. 2-DE was used to monitor the steady state protein levels of Geobacter metallireducens grown with either Fe(III) citrate or nitrate to elucidate metabolic differences in response to different terminal electron acceptors present in natural environments populated by Geobacter. Forty-six protein spots varied significantly in abundance (p&lt;0.05) between the two growth conditions; proteins were identified by tryptic peptide mass and peptide sequence determined by MS/MS. Enzymes involved in pyruvate metabolism and the tricarboxylic acid (TCA) cycle were more abundant in cells grown with Fe(III) citrate, while proteins associated with nitrate metabolism and sensing cellular redox status along with several proteins of unknown function were more abundant in cells grown with nitrate. These results indicate a higher level of flux through the TCA cycle in the presence of Fe(III) compared to nitrate. The oxidative stress response observed in previous studies of Geobacter sulfurreducens grown with Fe(III) citrate was not seen in G. metallireducens.</style></abstract><issue><style face="normal" font="default" size="100%">22</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/17994620?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%">Gregory, Kelvin B</style></author><author><style face="normal" font="default" size="100%">Bond, Daniel R</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%">Graphite electrodes as electron donors for anaerobic respiration.</style></title><secondary-title><style face="normal" font="default" size="100%">Environ Microbiol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Environ. Microbiol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Geologic Sediments</style></keyword><keyword><style  face="normal" font="default" size="100%">Graphite</style></keyword><keyword><style  face="normal" font="default" size="100%">Kinetics</style></keyword><keyword><style  face="normal" font="default" size="100%">Microscopy, Electron, Scanning</style></keyword><keyword><style  face="normal" font="default" size="100%">Nitrates</style></keyword><keyword><style  face="normal" font="default" size="100%">Phylogeny</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Ribosomal, 16S</style></keyword><keyword><style  face="normal" font="default" size="100%">Sequence Analysis, DNA</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004 Jun</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">6</style></volume><pages><style face="normal" font="default" size="100%">596-604</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">It has been demonstrated previously that Geobacter species can transfer electrons directly to electrodes. In order to determine whether electrodes could serve as electron donors for microbial respiration, enrichment cultures were established from a sediment inoculum with a potentiostat-poised graphite electrode as the sole electron donor and nitrate as the electron acceptor. Nitrate was reduced to nitrite with the consumption of electrical current. The stoichiometry of electron and nitrate consumption and nitrite accumulation were consistent with the electrode serving as the sole electron donor for nitrate reduction. Analysis of 16 rRNA gene sequences demonstrated that the electrodes supplied with current were specifically enriched in microorganisms with sequences most closely related to the sequences of known Geobacter species. A pure culture of Geobacter metallireducens was shown to reduce nitrate to nitrite with the electrode as the sole electron donor with the expected stoichiometry of electron consumption. Cells attached to the electrode appeared to be responsible for the nitrate reduction. Attached cells of Geobacter sulfurreducens reduced fumarate to succinate with the electrode as an electron donor. These results demonstrate for the first time that electrodes may serve as a direct electron donor for anaerobic respiration. This finding has implications for the harvesting of electricity from anaerobic sediments and the bioremediation of oxidized contaminants.</style></abstract><issue><style face="normal" font="default" size="100%">6</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15142248?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%">Esteve-Núñez, Abraham</style></author><author><style face="normal" font="default" size="100%">Núñez, Cinthia</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%">Preferential reduction of FeIII over fumarate by Geobacter sulfurreducens.</style></title><secondary-title><style face="normal" font="default" size="100%">J Bacteriol</style></secondary-title><alt-title><style face="normal" font="default" size="100%">J. Bacteriol.</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Fumarates</style></keyword><keyword><style  face="normal" font="default" size="100%">Geobacter</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Succinate Dehydrogenase</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2004 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">186</style></volume><pages><style face="normal" font="default" size="100%">2897-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">The presence of Fe(III), but not that of Fe(II), resulted in ca. 20-fold-lower levels of mRNA for fumarate reductase, inhibiting fumarate reduction and favoring utilization of fumarate as an electron donor in chemostat cultures of Geobacter sulfurreducens, despite the fact that growth yield with fumarate was 3-fold higher than with Fe(III).</style></abstract><issue><style face="normal" font="default" size="100%">9</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/15090532?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%">Bond, Daniel R</style></author><author><style face="normal" font="default" size="100%">Holmes, Dawn E</style></author><author><style face="normal" font="default" size="100%">Tender, Leonard M</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%">Electrode-reducing microorganisms that harvest energy from marine sediments.</style></title><secondary-title><style face="normal" font="default" size="100%">Science</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Science</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Aerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Anaerobiosis</style></keyword><keyword><style  face="normal" font="default" size="100%">Anthraquinones</style></keyword><keyword><style  face="normal" font="default" size="100%">Benzoates</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation, Environmental</style></keyword><keyword><style  face="normal" font="default" size="100%">Carbon Dioxide</style></keyword><keyword><style  face="normal" font="default" size="100%">Colony Count, Microbial</style></keyword><keyword><style  face="normal" font="default" size="100%">Deltaproteobacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">DNA, Ribosomal</style></keyword><keyword><style  face="normal" font="default" size="100%">Electricity</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrodes</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Energy Metabolism</style></keyword><keyword><style  face="normal" font="default" size="100%">Geologic Sediments</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">RNA, Ribosomal, 16S</style></keyword><keyword><style  face="normal" font="default" size="100%">Seawater</style></keyword><keyword><style  face="normal" font="default" size="100%">Sodium Acetate</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002 Jan 18</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">295</style></volume><pages><style face="normal" font="default" size="100%">483-5</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Energy in the form of electricity can be harvested from marine sediments by placing a graphite electrode (the anode) in the anoxic zone and connecting it to a graphite cathode in the overlying aerobic water. We report a specific enrichment of microorganisms of the family Geobacteraceae on energy-harvesting anodes, and we show that these microorganisms can conserve energy to support their growth by oxidizing organic compounds with an electrode serving as the sole electron acceptor. This finding not only provides a method for extracting energy from organic matter, but also suggests a strategy for promoting the bioremediation of organic contaminants in subsurface environments.</style></abstract><issue><style face="normal" font="default" size="100%">5554</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11799240?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%">Nevin, Kelly P</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%">Mechanisms for accessing insoluble Fe(III) oxide during dissimilatory Fe(III) reduction by Geothrix fermentans.</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%">Bacteria</style></keyword><keyword><style  face="normal" font="default" size="100%">Electrons</style></keyword><keyword><style  face="normal" font="default" size="100%">Ferric Compounds</style></keyword><keyword><style  face="normal" font="default" size="100%">Iron Chelating Agents</style></keyword><keyword><style  face="normal" font="default" size="100%">Oxidation-Reduction</style></keyword><keyword><style  face="normal" font="default" size="100%">Solubility</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2002 May</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">68</style></volume><pages><style face="normal" font="default" size="100%">2294-9</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Mechanisms for Fe(III) oxide reduction were investigated in Geothrix fermentans, a dissimilatory Fe(III)-reducing microorganism found within the Fe(III) reduction zone of subsurface environments. Culture filtrates of G. fermentans stimulated the reduction of poorly crystalline Fe(III) oxide by washed cell suspensions, suggesting that G. fermentans released one or more extracellular compounds that promoted Fe(III) oxide reduction. In order to determine if G. fermentans released electron-shuttling compounds, poorly crystalline Fe(III) oxide was incorporated into microporous alginate beads, which prevented contact between G. fermentans and the Fe(III) oxide. G. fermentans reduced the Fe(III) within the beads, suggesting that one of the compounds that G. fermentans releases is an electron-shuttling compound that can transfer electrons from the cell to Fe(III) oxide that is not in contact with the organism. Analysis of culture filtrates by thin-layer chromatography suggested that the electron shuttle has characteristics similar to those of a water-soluble quinone. Analysis of filtrates by ion chromatography demonstrated that there was as much as 250 microM dissolved Fe(III) in cultures of G. fermentans growing with Fe(III) oxide as the electron acceptor, suggesting that G. fermentans released one or more compounds capable of chelating and solubilizing Fe(III). Solubilizing Fe(III) is another strategy for alleviating the need for contact between cells and Fe(III) oxide for Fe(III) reduction. This is the first demonstration of a microorganism that, in defined medium without added electron shuttles or chelators, can reduce Fe(III) derived from Fe(III) oxide without directly contacting the Fe(III) oxide. These results are in marked contrast to those with Geobacter metallireducens, which does not produce electron shuttles or Fe(III) chelators. These results demonstrate that phylogenetically distinct Fe(III)-reducing microorganisms may use significantly different strategies for Fe(III) reduction. Thus, it is important to know which Fe(III)-reducing microorganisms predominate in a given environment in order to understand the mechanisms for Fe(III) reduction in the environment of interest.</style></abstract><issue><style face="normal" font="default" size="100%">5</style></issue><custom1><style face="normal" font="default" size="100%">http://www.ncbi.nlm.nih.gov/pubmed/11976100?dopt=Abstract</style></custom1></record></records></xml>