Geobacter sulfurreducens is a wellstudied representative of the geobacteraceae, which play a critical role in organic matter oxidation coupled to feiii reduction, bioremediation of groundwater contaminated with organics or metals, and electricity production from waste organic matter. Full text the full text of this article is available as a pdf 201k. Geobacter sulfurreducens was the first geobacter family member for which genetic manipulation methods were developed. Geobacter metallireducens accesses insoluble fe iii oxide. The ironreducing bacterium geobacter metallireducens was hypothesized to repress utilization of less preferred substrates in the presence of. This strict anaerobe oxidizes several shortchain fatty acids, alcohols, and monoaromatic compounds with feiii as the sole electron acceptor. Vanadium can be an important contaminant in groundwaters impacted by mining activities. Geobacter metallireducens metabolizes many aromatic compounds, but the enzymes involved are not well known. Genetic identification of a pilt motor in geobacter sulfurreducens. Expressing the geobacter metallireducens pila in geobacter. Cocultures formed aggregates that shared electrons via diet during the. Anaerobic phenol oxidation by geobacter metallireducens using various electron acceptors article pdf available in environmental engineering. Direct interspecies electron transfer between geobacter metallireducens and methanosarcina barkeri. Therefore, benzene metabolism was investigated in geobacter metallireducens, the only genetically tractable organism known to anaerobically degrade benzene.
Geobacter can be harnessed as microbial fuel cells to generate electricity from soil and food waste. Frontiers geobacter protein nanowires microbiology. A new species name, geobacter sulfurreducens, is proposed. Anaerobic benzene oxidation via phenol in geobacter. The genus geobacter represents the type genus of the family geobacteraceae which includes also the genera desulfuromonas, desulfuromusa, geoalkalibacter, geopsychrobacter, geothermobacter, malonomonas, and. The isolation of these organisms demonstrates that geobacter species are widely distributed in a diversity of sedimentary environments in which feiii reduction is an important process. Some of the geobacter species isolated to date can also reduce nitrate to ammonia geobacter argillaceus, g. The strict anaerobe geobacter metallireducens was cultivated in retentostats under acetate and acetate plus. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate allowed us to. Genetic evidence that the degradation of paracresol by.
Sep 30, 2011 geobacter are the junk food connoisseurs of the bacterial kingdom. Geobacter metallireducens was hypothesized to repress utilization of less preferred substrates in the presence of high concentrations of. In order to better understand this electron transfer process for energy production, geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate or. The metalreducing bacterium geobacter sulfurreducens requires the expression of conductive. The pilideficient strains of both geobacter species were able to form syntrophic growth with direct interspecies electron transfer. Characterization of metabolism in the feiiireducing. In our experiments, acetate and ethanol were preferred over benzoate, but benzoate was coconsumed with toluene and. In order to better understand this electron transfer process for energy production, geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served as the sole electron acceptor and acetate or hydrogen was the electron donor. Geobacter metallireducens gs15, a model of dissimilatory iron. Direct interspecies electron transfer diet is potentially an effective form of syntrophy in methanogenic communities, but little is known about the diversity of methanogens capable of diet. It is able to gain energy through the dissimilatory reduction of iron, manganese, uranium and other metals.
Flavinbased electron bifurcation fbeb is a longhidden mode of energetic coupling in which an endergonic electron transfer process is coupled to an exergonic one. It is rodshaped, obligately anaerobic, nonfermentative, has flagellum and type four pili, and is closely related to geobacter metallireducens. Anaerobic phenol oxidation by geobacter metallireducens using various electron acceptors article pdf available in environmental engineering science 224. A strain of geobacter, designated strain ben, was isolated from sediments from the feiiireducing zone of a. Frontiers identification of genes specifically required. Until recently, electrically conductive pili epili, assembled from the pila pilin monomer, were. Geobacter is rodshaped with flagella and is known to have unusual electron transfer and environmental restorative capabilities, giving it several industrial uses. Consequently, it has been used as the first choice for genomic and proteomic studies aiming to elucidate the bacterias metabolism, gene regulation and extracellular electron transfer mechanisms 1118. Thermodynamic and functional characterization of the.
Geobacter metallireducens gs15 jgi genome portal home. Geobacter is the name of a genus that is located within the deltaproteobacteria comprising several species of feiiireducing bacteria lovley et al. Geobacter a rod from the earth proteobacteria deltaproteobacteria desulfuromonales geobacteraceae geobacter. In fact, they can link together with neighboring geobacter buddies and transfer electrons through each other. Nevin and derek lovley department of microbiology, university of massachusetts, amherst, ma, usa. Pdf the genome sequence of geobacter metallireducens. Full text get a printable copy pdf file of the complete article 1.
The family is described as one of 22 families in the class deltaproteobacteria, although one of these families family nitrospinaceae has been tentatively reclassified to a candidate phylum and class in the bacteria roling, 2014. This approach to the use of an insoluble electron acceptor may explain why geobacter species predominate over. The geobacter metallireducens bacterium can couple the oxidation of a wide range of compounds to the reduction of several extracellular electron acceptors, including pollutants or electrode surfaces for current production in microbial fuel cells. The purified cytochrome c showed absorption peaks at 530 and 409 nm in the oxidized form and 552, 522, and 418 nm in the reduced form. The junk food connoisseurs of the bacterial kingdom. Syntrophic growth with direct interspecies electron.
Geobacter metallireducens is a rod shaped, gramnegative, anaerobic bacteria and can be seen to have flagella and pili. The ironreducing bacterium geobacter metallireducens was hypothesized to repress utilization of less preferred substrates in the presence of high concentrations of easily degradable compounds. Electricity production by geobacter sulfurreducens attached. Geobacter are the junk food connoisseurs of the bacterial kingdom. Geobacter was found to be the first organism with the ability to oxidize organic compounds and metals, including iron, radioactive metals, and petroleum compounds into. Previous studies have suggested that members of the geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. Cost procedure for growing geobacter sulfurreducens cell cultures and biofilms in bioelectrochemical systems j. Geobacter was found to be the first organism with the ability to oxidize organic compounds and metals, including iron, radioactive metals, and petroleum compounds into environmentally benign carbon dioxide. The goal of this project was to isolate representative feiiireducing bacteria from kaolin clays that may influence iron mineralogy in kaolin. In order to determine if microorganisms of the geobacteraceae, the predominant dissimilatory metal reducers in many subsurface environments, were capable of reducing vanadiumv, geobacter metallireducens was inoculated into a medium in which acetate was. The sequencing of geobacter sulfurreducens has led to new discoveries about the capabilities of geobacter.
How the emerging contaminant microplastics involved in the iron cycling are driven by microbes on the microscale remains unknown. Geobacter can remove radioactive metals from ground water by reducing metal ions as well. In order to determine if microorganisms of the geobacteraceae, the predominant dissimilatory metal reducers in many subsurface environments, were capable of reducing vanadiumv, geobacter metallireducens was inoculated into a medium in which acetate was the electron donor and vanadiumv was the sole. Geobacter is known as a type of bacteria that is able to conduct levels of electricity, and the species g. One of these microorganisms, geobacter metallireducens, has an unusual survival tactic for life in the underworld. Aug 05, 2005 geobacter sulfurreducens is a wellstudied representative of the geobacteraceae, which play a critical role in organic matter oxidation coupled to feiii reduction, bioremediation of groundwater contaminated with organics or metals, and electricity production. Genomic and microarray analysis of aromatics degradation.
Two novel dissimilatory feiiireducing bacteria, strains g12t and gt, were isolated from sedimentary kaolin strata in georgia usa. It can produce high current densities 20, and it has the ability to forge direct electrical connections with methanogenic microorganisms 25, 26 for direct interspecies electron transfer diet. Geobacter metallireducens is an important model organism for many novel aspects of extracellular electron exchange and the anaerobic degradation of aromatic compounds, but studies of its physiology have been limited by a lack of techniques for gene deletion and replacement. Syntrophic growth with direct interspecies electron transfer. Pdf direct interspecies electron transfer between geobacter. It is a strict anaerobe that oxidizes several shortchain fatty acids, alcohols, and monoaromatic compounds with feiii as the sole electron acceptor. Geobacter metallireducens strain gs15 atcc 53774 dsm 7210. Thermodynamic and functional characterization of the periplasmic. They have a healthy appetite for all sorts of unhealthy foods, including uranium and petroleum compounds like oil. Geobacter sulfurreducens is an anaerobic species of bacteria that comes from the family of bacteria called geobacteraceae. One such compound is petroleum contaminants in polluted ground water, which geobacter destroys through oxidation. Pdf anaerobic phenol oxidation by geobacter metallireducens. Piltmediated pilus retraction in geobacter sulfurreducens. Geobacter metallireducens, and probably also other geobacter species, requires physical attachment to the manganese or iron oxide surface childers et al.
Physiology of geobacter metallireducens under excess and. Geobacter metallireducens an overview sciencedirect topics. On the other hand, geobacter metallireducens was the. Geobacter metallireducens is a gramnegative metalreducing proteobacterium. Trace amounts pdf and any associated supplements and figures for a period of 48 hours. Summary geobacter metallireducens is an important model. The electrically conductive pili epili of geobacter sulfurreducens serve as a. Anaerobic activation of benzene is expected to represent a novel biochemistry of environmental significance. It can also use uranium for its growth and convert uvi to uiv geobacter metallireducens was discovered by derek lovley at umass amherst in 1993. Jan 15, 2020 geobacter metallireducens strain gs15 atcc 53774 dsm 7210 was isolated in the potomac river just downstream from washington d.
Geobacter metallireducens, the first organism found to completely oxidize organic compounds to carbon dioxide with feiii oxide serving as the electron acceptor 9,10,11, was previously reported. Furthermore, acetate is also oxidized with the reduction of mn iv, u vi, and nitrate. The function of the few fbeb complexes described so far is to achieve ferredoxin reduction at the negative redox limit of the biological redox window. Direct interspecies electron transfer diet was first demonstrated in the cocultures of geobacter metallireducens with geobacter sulfurreducens. Groundwater and subsurface environments contaminated with aromatic compounds can be remediated in situ by geobacter species that couple oxidation of these compounds to reduction of feiiioxides. Trace amounts mar, 2017 these pili, named nanowires, can be produced by ironreducing bacteria such as geobacter metallireducens 6 or geobacter sulfurreducens 7 that are even able to connect bacteria up to a centimetre. The study of electrically conductive protein nanowires in geobacter sulfurreducens has led to new concepts for longrange extracellular electron transport, as well as for the development of sustainable conductive materials and electronic devices with novel functions. The genus geobacter represents the type genus of the family geobacteraceae which includes also the genera desulfuromonas, desulfuromusa, geoalkalibacter, geopsychrobacter, geothermobacter, malonomonas, and pelobacter. The geobacter metallireducens bacterium can couple the oxidation of a wide range of. Cells of strains g12t and gt were motile, nonsporeforming regular rods, 12. Geobacter is the type and sole genus in the family geobacteraceae, one of two families in the order desulfuromonadales table 1. The ability of methanosarcina barkeri to participate in diet was evaluated in coculture with geobacter metallireducens.
Purification and characterization of triheme cytochrome c7. Inhibition effect of polyvinyl chloride on ferrihydrite. View enhanced pdf access article on wiley online library html view download pdf for offline viewing. Geobacter metallireducens atcc 53774 and dsm 7210 lovley et al. Direct interspecies electron transfer between geobacter. Patrick obrien department of molecular biophysics and biochemistry, microbial sciences institute, yale university, west haven, connecticut. Geobacter sulfurreducens is a rodshaped microbe with a gramnegative cell wall. Anaerobic benzene oxidation by geobacter species applied. Pdf the genome sequence of geobacter metallireducens is the second to be completed from the metalrespiring genus geobacter. Electricity production by geobacter sulfurreducens. The gramnegative metalreducing microorganism, previously known as strain gs15, was further characterized. Apr 18, 2002 geobacter metallireducens, the first organism found to completely oxidize organic compounds to carbon dioxide with feiii oxide serving as the electron acceptor 9,10,11, was previously reported.
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