Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| involvement of a membrane-bound class iii adenylate cyclase in regulation of anaerobic respiration in shewanella oneidensis mr-1. | unlike other bacteria that use fnr to regulate anaerobic respiration, shewanella oneidensis mr-1 uses the cyclic amp receptor protein (crp) for this purpose. three putative genes, cyaa, cyab, and cyac, predicted to encode class i, class iv, and class iii adenylate cyclases, respectively, have been identified in the genome sequence of this bacterium. functional validation through complementation of an escherichia coli cya mutant confirmed that these genes encode proteins with adenylate cyclase ac ... | 2009 | 19395492 |
| motx and moty are required for flagellar rotation in shewanella oneidensis mr-1. | the single polar flagellum of shewanella oneidensis mr-1 is powered by two different stator complexes, the sodium-dependent pomab and the proton-driven motab. in addition, shewanella harbors two genes with homology to motx and moty of vibrio species. in vibrio, the products of these genes are crucial for sodium-dependent flagellar rotation. resequencing of s. oneidensis mr-1 moty revealed that the gene does not harbor an authentic frameshift as was originally reported. mutational analysis demons ... | 2009 | 19502394 |
| the agglutination protein agga from shewanella oneidensis mr-1 is a tolc-like protein and forms active channels in vitro. | type i secretion systems (tiss) are associated with the virulence of gram-negative bacteria and the secretion of pathogenic molecular determinants. the shewanella oneidensis mr-1 outer-membrane protein agga is part of a tiss. recombinant agga expressed in escherichia coli as inclusion bodies can be efficiently refolded in vitro, and can form active channel-tunnels as shown by proteoliposome swelling assays and electrophysiological measurements in lipid bilayers. structure-based sequence alignmen ... | 2009 | 19524550 |
| anaerobic respiration of elemental sulfur and thiosulfate by shewanella oneidensis mr-1 requires psra, a homolog of the phsa gene of salmonella enterica serovar typhimurium lt2. | shewanella oneidensis mr-1, a facultatively anaerobic gammaproteobacterium, respires a variety of anaerobic terminal electron acceptors, including the inorganic sulfur compounds sulfite (so3(2-)), thiosulfate (s2o3(2-)), tetrathionate (s4o6(2-)), and elemental sulfur (s(0)). the molecular mechanism of anaerobic respiration of inorganic sulfur compounds by s. oneidensis, however, is poorly understood. in the present study, we identified a three-gene cluster in the s. oneidensis genome whose trans ... | 2009 | 19542325 |
| kinetic characterization of omca and mtrc, terminal reductases involved in respiratory electron transfer for dissimilatory iron reduction in shewanella oneidensis mr-1. | we have used scaling kinetics and the concept of kinetic competence to elucidate the role of hemeproteins omca and mtrc in iron reduction by shewanella oneidensis mr-1. second-order rate constants for omca and mtrc were determined by single-turnover experiments. for soluble iron species, a stopped-flow apparatus was used, and for the less reactive iron oxide goethite, a conventional spectrophotometer was used to measure rates. steady-state experiments were performed to obtain molecular rate cons ... | 2009 | 19542342 |
| on-line digestion system for protein characterization and proteome analysis. | an efficient on-line digestion system that reduces the number of sample manipulation steps has been demonstrated for high-throughput proteomics. by incorporating a pressurized sample loop into a liquid chromatography-based separation system, both sample and enzyme (e.g., trypsin) can be simultaneously introduced to produce a complete, yet rapid digestion. both standard proteins and a complex shewanella oneidensis global protein extract were digested and analyzed using the automated online pressu ... | 2008 | 19551971 |
| evaluation of a high-intensity focused ultrasound-immobilized trypsin digestion and 18o-labeling method for quantitative proteomics. | a new method that uses immobilized trypsin concomitant with ultrasonic irradiation results in ultrarapid digestion and more thorough (18)o labeling for quantitative protein comparisons. the method was reproducible and provided effective digestions within <1 min with lower amounts of enzyme, compared to traditional methods. this method was demonstrated for digestion of both simple and complex protein mixtures, including bovine serum albumin, a global proteome extract from the bacteria shewanella ... | 2009 | 19555078 |
| unexpected chemoreceptors mediate energy taxis towards electron acceptors in shewanella oneidensis. | shewanella oneidensis uses a wide range of terminal electron acceptors for respiration. in this study, we show that the chemotactic response of s. oneidensis to anaerobic electron acceptors requires functional electron transport systems. deletion of the genes encoding dimethyl sulphoxide and trimethylamine n-oxide reductases, or inactivation of these molybdoenzymes as well as nitrate reductase by addition of tungstate, abolished electron acceptor taxis. moreover, addition of nigericin prevented ... | 2009 | 19555457 |
| remediation of trichloroethylene by bio-precipitated and encapsulated palladium nanoparticles in a fixed bed reactor. | trichloroethylene is a toxic and recalcitrant groundwater pollutant. palladium nanoparticles bio-precipitated on shewanella oneidensis were encapsulated in polyurethane, polyacrylamide, alginate, silica or coated on zeolites. the reactivity of these bio-pd beads and zeolites was tested in batch experiments and trichloroethylene dechlorination followed first order reaction kinetics. the calculated k-values of the encapsulated catalysts were a factor of six lower compared to non-encapsulated bio-p ... | 2009 | 19560796 |
| the role of 4-hydroxyphenylpyruvate dioxygenase in enhancement of solid-phase electron transfer by shewanella oneidensis mr-1. | we hypothesized that shewanella oneidensis mr-1, a model dissimilatory metal-reducing bacterium, could utilize environmentally relevant concentrations of tyrosine to produce pyomelanin for enhanced fe(iii) oxide reduction. because homogentisate is an intermediate of the tyrosine degradation pathway, and a precursor of a redox-cycling metabolite, pyomelanin, we evaluated the process of homogentisate production by s. oneidensis mr-1, in order to identify the key steps involved in pyomelanin produc ... | 2009 | 19573203 |
| impedance spectroscopy as a tool for non-intrusive detection of extracellular mediators in microbial fuel cells. | endogenously produced, diffusible redox mediators can act as electron shuttles for bacterial respiration. accordingly, the mediators also serve a critical role in microbial fuel cells (mfcs), as they assist extracellular electron transfer from the bacteria to the anode serving as the intermediate electron sink. electrochemical impedance spectroscopy (eis) may be a valuable tool for evaluating the role of mediators in an operating mfc. eis offers distinct advantages over some conventional analyti ... | 2009 | 19585525 |
| intermittent energy harvesting improves the performance of microbial fuel cells. | in this study, we compare the efficiencies of harvesting energy from microbial fuel cells (mfc) using two modes of operation: (1) continuous-passing the current through an electrical load-and (2) intermittent-first accumulating the energy in a capacitor and then discharging it through the load. each of these two modes of operation has advantages and disadvantages: the first mode of operation allows the continuous powering of low-power-consuming devices, and the second mode of operation allows th ... | 2009 | 19603683 |
| invariability of central metabolic flux distribution in shewanella oneidensis mr-1 under environmental or genetic perturbations. | an environmentally important bacterium with versatile respiration, shewanella oneidensis mr-1, displayed significantly different growth rates under three culture conditions: minimal medium (doubling time approximately 3 h), salt stressed minimal medium (doubling time approximately 6 h), and minimal medium with amino acid supplementation (doubling time approximately 1.5 h). (13)c-based metabolic flux analysis indicated that fluxes of central metabolic reactions remained relatively constant under ... | 2009 | 19610125 |
| electrochemical measurement of electron transfer kinetics by shewanella oneidensis mr-1. | shewanella oneidensis strain mr-1 can respire using carbon electrodes and metal oxyhydroxides as electron acceptors, requiring mechanisms for transferring electrons from the cell interior to surfaces located beyond the cell. although purified outer membrane cytochromes will reduce both electrodes and metals, s. oneidensis also secretes flavins, which accelerate electron transfer to metals and electrodes. we developed techniques for detecting direct electron transfer by intact cells, using turnov ... | 2009 | 19661057 |
| microfabricated microbial fuel cell arrays reveal electrochemically active microbes. | microbial fuel cells (mfcs) are remarkable "green energy" devices that exploit microbes to generate electricity from organic compounds. mfc devices currently being used and studied do not generate sufficient power to support widespread and cost-effective applications. hence, research has focused on strategies to enhance the power output of the mfc devices, including exploring more electrochemically active microbes to expand the few already known electricigen families. however, most of the mfc de ... | 2009 | 19668333 |
| shewanella xiamenensis sp. nov., isolated from coastal sea sediment. | a gram-negative, motile, rod-shaped bacterium, strain s4(t), was isolated from coastal sediment collected off xiamen, china. the physiological and biochemical features of strain s4(t), determined using the api 20ne, api zym and biolog gn2 systems, were similar to those of members of the genus shewanella. phylogenetic analyses based on 16s rrna and gyrb gene sequences placed strain s4(t) in the genus shewanella, and it was most closely related to shewanella oneidensis and related species. dna-dna ... | 2010 | 19684319 |
| biogenic formation of as-s nanotubes by diverse shewanella strains. | shewanella sp. strain hn-41 was previously shown to produce novel, photoactive, as-s nanotubes via the reduction of as(v) and s(2)o(3)(2-) under anaerobic conditions. to determine if this ability was unique to this bacterium, 10 different shewanella strains, including shewanella sp. strain hn-41, shewanella sp. strain pv-4, shewanella alga bry, shewanella amazonensis sb2b, shewanella denitrificans os217, shewanella oneidensis mr-1, shewanella putrefaciens cn-32, s. putrefaciens ir-1, s. putrefac ... | 2009 | 19717628 |
| power production in mfcs inoculated with shewanella oneidensis mr-1 or mixed cultures. | power densities and oxidation-reduction potentials (orps) of mfcs containing a pure culture of shewanella oneidensis mr-1 were compared to mixed cultures (wastewater inoculum) in cube shaped, 1-, 2-, and 3-bottle batch-fed mfc reactor configurations. the reactor architecture influenced the relative power produced by the different inocula, with the mixed culture generating 68-480% more power than mr-1 in each mfc configuration. the mixed culture produced the maximum power density of 858 +/- 9 mw ... | 2010 | 19787640 |
| crystal structure of 4-hydroxybutyrate coa-transferase from clostridium aminobutyricum. | 4-hydroxybutyrate coa-transferases (4-hb-coat) takes part in the fermentation of 4-aminobutyrate to ammonia, acetate, and butyrate in anaerobic bacteria such as clostridium aminobutyricum and porphyromonas gingivalis or facultative anaerobic bacteria such as shewanella oneidensis. site-directed mutagenesis of the highly active enzyme has identified the catalytic glutamate residue as e238. crystal structure of this enzyme has been determined at a resolution of 1.85 a. the 438-amino acid residue p ... | 2009 | 19804364 |
| a 1.5 microl microbial fuel cell for on-chip bioelectricity generation. | we have developed a dual-chamber microfluidic microbial fuel cell (mfc) system that allows on-chip bacterial culture and conversion of bacterial metabolism into electricity. the micro-mfc contains a vertically stacked 1.5 microl anode chamber and 4 microl cathode chamber, and represents the smallest mfc device to our knowledge. microfluidic deliveries of growth medium and catholyte were achieved in separate flow channels without cross-channel mass exchange. after inoculation of electrogenic shew ... | 2009 | 19823722 |
| periplasmic electron transfer via the c-type cytochromes mtra and fcca of shewanella oneidensis mr-1. | dissimilatory microbial reduction of insoluble fe(iii) oxides is a geochemically and ecologically important process which involves the transfer of cellular, respiratory electrons from the cytoplasmic membrane to insoluble, extracellular, mineral-phase electron acceptors. in this paper evidence is provided for the function of the periplasmic fumarate reductase fcca and the decaheme c-type cytochrome mtra in periplasmic electron transfer reactions in the gammaproteobacterium shewanella oneidensis. ... | 2009 | 19837833 |
| analyses of current-generating mechanisms of shewanella loihica pv-4 and shewanella oneidensis mr-1 in microbial fuel cells. | although members of the genus shewanella have common features (e.g., the presence of decaheme c-type cytochromes [c-cyts]), they are widely variable in genetic and physiological features. the present study compared the current-generating ability of s. loihica pv-4 in microbial fuel cells (mfcs) with that of well-characterized s. oneidensis mr-1 and examined the roles of c-cyts in extracellular electron transfer. we found that strains pv-4 and mr-1 exhibited notable differences in current-generat ... | 2009 | 19837834 |
| carbon nanotubes as electrode modifier promoting direct electron transfer from shewanella oneidensis. | this study compared voltammetric behavior and catalytic current generation of shewanella oneidensis on glassy carbon electrode (gce) with and without carbon nanotube (cnt) modifier. a bare gce in an electrochemical cell inoculated with s. oneidensis delivered a low current density of 0.117+/-0.006 microa/cm(2) after being anodically polarized for 15h. cyclic voltammogram suggested current generation could be attributed to s. oneidensis's cell surface cytochromes. but the cytochromes demonstrated ... | 2010 | 19897352 |
| the mtr respiratory pathway is essential for reducing flavins and electrodes in shewanella oneidensis. | the mtr respiratory pathway of shewanella oneidensis strain mr-1 is required to effectively respire both soluble and insoluble forms of oxidized iron. flavins (riboflavin and flavin mononucleotide) recently have been shown to be excreted by mr-1 and facilitate the reduction of insoluble substrates. other shewanella species tested accumulated flavins in supernatants to an extent similar to that of mr-1, suggesting that flavin secretion is a general trait of the species. external flavins have been ... | 2010 | 19897659 |
| piezo-adapted 3-isopropylmalate dehydrogenase of the obligate piezophile shewanella benthica db21mt-2 isolated from the 11,000-m depth of the mariana trench. | 3-isopropylmalate dehydrogenase (ipmdh)-encoding leub genes were obtained from the obligate piezophile shewanella benthica db21mt-2 and non-piezophile shewanella oneidensis mr-1. the genes were expressed in escherichia coli and the proteins were purified using his-tag. the estimated kinetic parameters of these enzymes indicated that ipmdh of s. benthica db21mt-2 is more tolerant of high pressure than that of s. oneidensis mr-1. thus such an adaptation is one of the mechanisms bacteria utilize fo ... | 2009 | 19897891 |
| microbesonline: an integrated portal for comparative and functional genomics. | since 2003, microbesonline (http://www.microbesonline.org) has been providing a community resource for comparative and functional genome analysis. the portal includes over 1000 complete genomes of bacteria, archaea and fungi and thousands of expression microarrays from diverse organisms ranging from model organisms such as escherichia coli and saccharomyces cerevisiae to environmental microbes such as desulfovibrio vulgaris and shewanella oneidensis. to assist in annotating genes and in reconstr ... | 2010 | 19906701 |
| a structural basis for h-nox signaling in shewanella oneidensis by trapping a histidine kinase inhibitory conformation. | heme nitric oxide/oxygen (h-nox) proteins are found in eukaryotes where they are typically part of a larger protein such as soluble guanylate cyclase and in prokaryotes where they are often found in operons with a histidine kinase, suggesting that h-nox proteins serve as sensors for no and o(2) in signaling pathways. the fe(ii)-no complex of the h-nox protein from shewanella oneidensis inhibits the autophosphorylation of the operon-associated histidine kinase, whereas the ligand-free h-nox has n ... | 2009 | 19918063 |
| bacterial responses to cu-doped tio(2) nanoparticles. | the toxicity of cu-doped tio(2) nanoparticles (nps, 20nm), synthesized by a flame aerosol reactor, to mycobacterium smegmatis and shewanella oneidensis mr-1, is the primary focus of this study. both doped and non-doped tio(2) nps (20nm) tended to agglomerate in the medium solution, and therefore did not penetrate into the cell and damage cellular structures. tio(2) particles (<100mg/l) did not apparently interfere with the growth of the two species in aqueous cultures. cu-doped tio(2) nps (20mg/ ... | 2010 | 19931887 |
| investigating different mechanisms for biogenic selenite transformations: geobacter sulfurreducens, shewanella oneidensis and veillonella atypica. | the metal-reducing bacteria geobacter sulfurreducens, shewanella oneidensis and veillonella atypica, use different mechanisms to transform toxic, bioavailable sodium selenite to less toxic, non-mobile elemental selenium and then to selenide in anaerobic environments, offering the potential for in situ and ex situ bioremediation of contaminated soils, sediments, industrial effluents, and agricultural drainage waters. the products of these reductive transformations depend on both the organism invo ... | 2009 | 19950474 |
| the periplasmic nitrate reductase in shewanella: the resolution, distribution and functional implications of two nap isoforms, napedabc and napdaghb. | in the bacterial periplasm, the reduction of nitrate to nitrite is catalysed by a periplasmic nitrate reductase (nap) system, which is a species-dependent assembly of protein subunits encoded by the nap operon. the reduction of nitrate catalysed by nap takes place in the 90 kda napa subunit, which contains a mo-bis-molybdopterin guanine dinucleotide cofactor and one [4fe-4s] iron-sulfur cluster. a review of the nap operons in the genomes of 19 strains of shewanella shows that most genomes contai ... | 2010 | 19959582 |
| aerated shewanella oneidensis in continuously fed bioelectrochemical systems for power and hydrogen production. | we studied the effects of aeration of shewanella oneidensis on potentiostatic current production, hydrogen production in a microbial electrolysis cell, and electric power generation in a microbial fuel cell (mfc). the potentiostatic performance of aerated s. oneidensis was considerably enhanced to a maximum current density of 0.45 a/m(2) or 80.3 a/m(3) (mean: 0.34 a/m(2), 57.2 a/m(3)) compared to anaerobically grown cultures. biocatalyzed hydrogen production rates with aerated s. oneidensis were ... | 2010 | 19998276 |
| role of outer-membrane cytochromes mtrc and omca in the biomineralization of ferrihydrite by shewanella oneidensis mr-1. | in an effort to improve the understanding of electron transfer mechanisms at the microbe-mineral interface, shewanella oneidensis mr-1 mutants with in-frame deletions of outer-membrane cytochromes (omcs), mtrc and omca, were characterized for the ability to reduce ferrihydrite (fh) using a suite of microscopic, spectroscopic, and biochemical techniques. analysis of purified recombinant proteins demonstrated that both cytochromes undergo rapid electron exchange with fh in vitro with mtrc displayi ... | 2010 | 20002197 |
| impact of silver(i) on the metabolism of shewanella oneidensis. | anaerobic cultures of shewanella oneidensis mr-1 reduced toxic ag(i), forming nanoparticles of elemental ag(0), as confirmed by x-ray diffraction analyses. the addition of 1 to 50 microm ag(i) had a limited impact on growth, while 100 microm ag(i) reduced both the doubling time and cell yields. at this higher ag(i) concentration transmission electron microscopy showed the accumulation of elemental silver particles within the cell, while at lower concentrations the metal was exclusively reduced a ... | 2010 | 20008067 |
| electrokinesis is a microbial behavior that requires extracellular electron transport. | we report a previously undescribed bacterial behavior termed electrokinesis. this behavior was initially observed as a dramatic increase in cell swimming speed during reduction of solid mno(2) particles by the dissimilatory metal-reducing bacterium shewanella oneidensis mr-1. the same behavioral response was observed when cells were exposed to small positive applied potentials at the working electrode of a microelectrochemical cell and could be tuned by adjusting the potential on the working ele ... | 2010 | 20018675 |
| the 285 kda bap/rtx hybrid cell surface protein (so4317) of shewanella oneidensis mr-1 is a key mediator of biofilm formation. | shewanella oneidensis, a gram-negative bacterium with unusual respiratory versatility, is found in soil and sediment environments, and sporadically as an opportunistic pathogen in humans and aquatic animals. the ability to form biofilms is a critical factor in the environmental spread and survival of this bacterium. we subjected s. oneidensis mr-1 to random transposon insertion mutagenesis to identify genes contributing to the ability of the organism to form biofilms on polystyrene surfaces. fol ... | 2010 | 20034561 |
| hydrous manganese oxide doped gel probe sampler for measuring in situ reductive dissolution rates. 1. laboratory development. | reductive dissolution of redox-sensitive minerals such as manganese (mn) oxides in natural sediments is an important mechanism for trace element mobilization into groundwater. a gel probe sampler has been constructed to study in situ reductive dissolution of mn oxides. the gel consists of a polyacrylamide polymer matrix doped with hydrous mn oxide (hmo). gel slabs are mounted into a probe, which is designed to be inserted into the sediments. the amount of mn released from the gel by reductive di ... | 2010 | 20039731 |
| outer membrane-associated serine protease involved in adhesion of shewanella oneidensis to fe(iii) oxides. | the facultative anaerobe shewanella oneidensis mr-1 respires a variety of anaerobic electron acceptors, including insoluble fe(iii) oxides. s. oneidensis employs a number of novel strategies for respiration of insoluble fe(iii) oxides, including localization of respiratory proteins to the cell outer membrane (om). the molecular mechanism by which s. oneidensis adheres to and respires fe(iii) oxides, however, remains poorly understood. in the present study, whole cell fractionation and maldi-tof- ... | 2010 | 20039735 |
| towards structural studies of the old yellow enzyme homologue sye4 from shewanella oneidensis and its complexes at atomic resolution. | shewanella oneidensis is an environmentally versatile gram-negative gamma-proteobacterium that is endowed with an unusually large proteome of redox proteins. of the four old yellow enzyme (oye) homologues found in s. oneidensis, sye4 is the homologue most implicated in resistance to oxidative stress. sye4 was recombinantly expressed in escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. the crystals belonged to the orthorhombic space group p2(1)2(1)2(1) an ... | 2010 | 20057079 |
| shewanella oneidensis mr-1 mutants selected for their inability to produce soluble organic-fe(iii) complexes are unable to respire fe(iii) as anaerobic electron acceptor. | recent voltammetric analyses indicate that shewanella putrefaciens strain 200 produces soluble organic-fe(iii) complexes during anaerobic respiration of sparingly soluble fe(iii) oxides. results of the present study expand the range of shewanella species capable of producing soluble organic-fe(iii) complexes to include shewanella oneidensis mr-1. soluble organic-fe(iii) was produced by s. oneidensis cultures incubated anaerobically with fe(iii) oxides, or with fe(iii) oxides and the alternate el ... | 2010 | 20089045 |
| molecular basis for directional electron transfer. | biological macromolecules involved in electron transfer reactions display chains of closely packed redox cofactors when long distances must be bridged. this is a consequence of the need to maintain a rate of transfer compatible with metabolic activity in the framework of the exponential decay of electron tunneling with distance. in this work intermolecular electron transfer was studied in kinetic experiments performed with the small tetraheme cytochrome from shewanella oneidensis mr-1 and from s ... | 2010 | 20089857 |
| comparative eco-toxicities of nano-zno particles under aquatic and aerosol exposure modes. | the antimicrobial activity of zno nanoparticles (nps) was investigated under aquatic and aerosol exposure modes. zno nps in aquatic media aggregated to micrometer-sized particles and did not interact with microorganisms effectively. hence, the inhibition of microbial growth by nano-zno nps (e.g., mycobacterium smegmatis and cyanothece 51142) in aquatic media was mainly attributable to dissolved zinc species. shewanella oneidensis mr-1 and escherichia coli were able to produce large amounts of ex ... | 2010 | 20102184 |
| adhesion of shewanella oneidensis mr-1 to iron (oxy)(hydr)oxides: microcolony formation and isotherm. | the adhesion of dissimilatory metal reducing bacteria (dmrb) to iron (oxy)(hydr)oxides may play an important role in their respiration on ferric iron-containing minerals, but few quantitative surface cell density measurements have been made thus far. we used confocal microscopy to examine the adhesion of a common dmrb species, shewanella oneidensis mr-1, onto iron (oxy)(hydr)oxide particulate-coated glass slides across a broad range of bulk (i.e., solution phase) cell densities from 10(5) cells/ ... | 2010 | 20131792 |
| siderophores are not involved in fe(iii) solubilization during anaerobic fe(iii) respiration by shewanella oneidensis mr-1. | shewanella oneidensis mr-1 respires a wide range of anaerobic electron acceptors, including sparingly soluble fe(iii) oxides. in the present study, s. oneidensis was found to produce fe(iii)-solubilizing organic ligands during anaerobic fe(iii) oxide respiration, a respiratory strategy postulated to destabilize fe(iii) and produce more readily reducible soluble organic fe(iii). in-frame gene deletion mutagenesis, siderophore detection assays, and voltammetric techniques were combined to determin ... | 2010 | 20190086 |
| shewregdb: database and visualization environment for experimental and predicted regulatory information in shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is an important model organism for environmental research as it has an exceptional metabolic and respiratory versatility regulated by a complex regulatory network. we have developed a database to collect experimental and computational data relating to regulation of gene and protein expression, and, a visualization environment that enables integration of these data types. the regulatory information in the database includes predictions of dna regulator binding sites, sig ... | 2009 | 20198195 |
| quantification of electron transfer rates to a solid phase electron acceptor through the stages of biofilm formation from single cells to multicellular communities. | microbial fuel cell (mfc) technology has enabled new insights into the mechanisms of electron transfer from dissimilatory metal reducing bacteria to a solid phase electron acceptor. using solid electrodes as electron acceptors enables quantitative real-time measurements of electron transfer rates to these surfaces. we describe here an optically accessible, dual anode, continuous flow mfc that enables real-time microscopic imaging of anode populations as they develop from single attached cells to ... | 2010 | 20199066 |
| the effect of detergents and lipids on the properties of the outer-membrane protein omca from shewanella oneidensis. | the protein omca from the bacterium shewanella oneidensis was purified to homogeneity, and characterized using uv-vis spectroelectrochemistry, epr, and circular dichroism (far- and near-uv regions). epr spectroscopy showed that many different c-type hemes are present in the protein: high-spin, low-spin, and highly anisotropic low-spin hemes were all detected. the protein was shown to bind tightly to artificial membranes (liposomes) composed of dioleoylphosphatidylglycerol and 1-palmitoyl-2-oleoy ... | 2010 | 20229092 |
| the chemical-in-plug bacterial chemotaxis assay is prone to false positive responses. | abstract: | 2010 | 20233446 |
| arcs, the cognate sensor kinase in an atypical arc system of shewanella oneidensis mr-1. | the availability of oxygen is a major environmental factor for many microbes, in particular for bacteria such as shewanella species, which thrive in redox-stratified environments. one of the best-studied systems involved in mediating the response to changes in environmental oxygen levels is the arc two-component system of escherichia coli, consisting of the sensor kinase arcb and the cognate response regulator arca. an arca ortholog was previously identified in shewanella, and as in escherichia ... | 2010 | 20348304 |
| probing the ternary complexes of indoleamine and tryptophan 2,3-dioxygenases by cryoreduction epr and endor spectroscopy. | we have applied cryoreduction/epr/endor techniques to characterize the active-site structure of the ferrous-oxy complexes of human (hido) and shewanella oneidensis (sido) indoleamine 2,3-dioxygenases, xanthomonas campestris (xctdo) tryptophan 2,3-dioxygenase, and the h55s variant of xctdo in the absence and in the presence of the substrate l-trp and a substrate analogue, l-me-trp. the results reveal the presence of multiple conformations of the binary ferrous-oxy species of the idos. in more pop ... | 2010 | 20353179 |
| involvement and specificity of shewanella oneidensis outer membrane cytochromes in the reduction of soluble and solid-phase terminal electron acceptors. | the formation of outer membrane (om) cytochromes seems to be a key step in the evolution of dissimilatory iron-reducing bacteria. they are believed to be the endpoints of an extended respiratory chain to the surface of the cell that establishes the connection to insoluble electron acceptors such as iron or manganese oxides. the gammaproteobacterium shewanella oneidensis mr-1 contains the genetic information for five putative om cytochromes. in this study, the role and specificity of these protei ... | 2010 | 20370837 |
| quantitative analysis of cell surface membrane proteins using membrane-impermeable chemical probe coupled with 18o labeling. | we report a mass spectrometry-based strategy for quantitative analysis of cell surface membrane proteome changes. the strategy includes enrichment of surface membrane proteins using a membrane-impermeable chemical probe followed by stable isotope (18)o labeling and lc-ms analysis. we applied this strategy for enriching membrane proteins expressed by shewanella oneidensis mr-1, a gram-negative bacterium with known metal-reduction capability via extracellular electron transfer between outer membra ... | 2010 | 20380418 |
| imaging metals in proteins by combining electrophoresis with rapid x-ray fluorescence mapping. | growing evidence points toward a very dynamic role for metals in biology. this suggests that physiological circumstance may mandate metal ion redistribution among ligands. this work addresses a critical need for technology that detects, identifies, and measures the metal-containing components of complex biological matrixes. we describe a direct, user-friendly approach for identifying and quantifying metal-protein adducts in complex samples using native- or sds-page, blotting, and rapid synchrotr ... | 2010 | 20392082 |
| substrate-level phosphorylation is the primary source of energy conservation during anaerobic respiration of shewanella oneidensis strain mr-1. | it is well established that respiratory organisms use proton motive force to produce atp via f-type atp synthase aerobically and that this process may reverse during anaerobiosis to produce proton motive force. here, we show that shewanella oneidensis strain mr-1, a nonfermentative, facultative anaerobe known to respire exogenous electron acceptors, generates atp primarily from substrate-level phosphorylation under anaerobic conditions. mutant strains lacking acka (so2915) and pta (so2916), gene ... | 2010 | 20400539 |
| arcb1, a homolog of escherichia coli arcb, regulates dimethyl sulfoxide reduction in shewanella oneidensis mr-1. | shewanella oneidensis is a metal reducer that uses the cyclic amp receptor protein, crp, to regulate anaerobic respiration. in addition, arca(so) is required for anaerobic growth with dimethyl sulfoxide (dmso) and plays a role in aerobic respiration. the sensor kinase that activates arca(so) in s. oneidensis is not known. arcb1(so), a homolog of the escherichia coli sensor kinase arcb(ec), was identified and found to be required for dmso reductase gene expression. in combination with hpta, arcb1 ... | 2010 | 20400540 |
| widespread head-to-head hydrocarbon biosynthesis in bacteria and role of olea. | previous studies identified the oleabcd genes involved in head-to-head olefinic hydrocarbon biosynthesis. the present study more fully defined the oleabcd protein families within the thiolase, alpha/beta-hydrolase, amp-dependent ligase/synthase, and short-chain dehydrogenase superfamilies, respectively. only 0.1 to 1% of each superfamily represents likely ole proteins. sequence analysis based on structural alignments and gene context was used to identify highly likely ole genes. selected microor ... | 2010 | 20418421 |
| structure, function, and insights into the biosynthesis of a head-to-head hydrocarbon in shewanella oneidensis strain mr-1. | a polyolefinic hydrocarbon was found in nonpolar extracts of shewanella oneidensis mr-1 and identified as 3,6,9,12,15,19,22,25,28-hentriacontanonaene (compound i) by mass spectrometry, chemical modification, and nuclear magnetic resonance spectroscopy. compound i was shown to be the product of a head-to-head fatty acid condensation biosynthetic pathway dependent on genes denoted as ole (for olefin biosynthesis). four ole genes were present in s. oneidensis mr-1. deletion of the entire oleabcd ge ... | 2010 | 20418444 |
| in-situ magnetic susceptibility measurements as a tool to follow geomicrobiological transformation of fe minerals. | fe minerals sorb nutrients and pollutants and participate in microbial and abiotic redox reactions. formation and transformation of fe minerals is typically followed by mineral analysis at different time points. however, in lab studies the available sample amount is often limited and sampling may even influence the experimental conditions. we therefore evaluated the suitability of in situ magnetic susceptibility (ms) measurements, which do not require sampling, as an alternative tool to follow f ... | 2010 | 20426439 |
| electrode potential regulates cytochrome accumulation on shewanella oneidensis cell surface and the consequence to bioelectrocatalytic current generation. | this study investigated the physiological response of shewanella oneidensis to the electrode potential and its effect on biological current generation. the electrode-attached s. oneidensis cells expressed cytochromes omca/mtrc at the bacteria-electrode interface when the electrode was poised at 0v (vs. sce), but not when the poised potential was -0.24v. cytochromes that had already been deposited on the interface were eliminated under -0.24v. unexpectedly, current density under the higher poised ... | 2010 | 20427175 |
| disruption of the putative cell surface polysaccharide biosynthesis gene so3177 in shewanella oneidensis mr-1 enhances adhesion to electrodes and current generation in microbial fuel cells. | a microbial fuel cell (mfc) was inoculated with a random transposon insertion mutant library of shewanella oneidensis mr-1 and operated with lactate as the sole fuel to select for mutants that preferentially grew in it. agar plate cultivation of the resultant mfc enrichment culture detected an increased number of colonies exhibiting rough morphology. one such isolate, strain 4a, generated 50% more current in an mfc than wild-type mr-1. determination of the transposon insertion site in strain 4a ... | 2010 | 20453127 |
| enhancement of survival and electricity production in an engineered bacterium by light-driven proton pumping. | microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. the discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. here, we describe functional expression of proteorhodopsin and light-induced changes in membr ... | 2010 | 20453141 |
| comparative analysis of highly homologous shewanella cytochromes c5 for stability and function. | homologous cytochromes c(5) from a mesophile, shewanella amazonensis (sa cytc(5)), and a psychrophile, shewanella violacea (sv cytc(5)), were compared to elucidate the molecular mechanisms underlying protein stability and function. cyclic voltammetry revealed that the two proteins had the same redox potential value. differential scanning calorimetry showed that sv cytc(5) was more stable than sa cytc(5) in an enthalpic manner. these results and the structure model of shewanella oneidensis cytoch ... | 2010 | 20460724 |
| spatiotemporal activity of the msha gene system in shewanella oneidensis mr-1 biofilms. | type iv pili and a putative eps biosynthetic gene cluster (mxdabcd) have been implicated previously in biofilm formation in shewanella oneidensis mr-1. here, we report that the mannose-sensitive hemagglutinin (msha) pilus mediates a reversible, d-mannose-sensitive association of cells to the substratum surface or to other cells that is critical within the first 5 microm of the biofilm from the substratum. the presence of the msha pilus alone is insufficient to confer biofilm-forming capacity; it ... | 2010 | 20487019 |
| genome-wide expression links the electron transfer pathway of shewanella oneidensis to chemotaxis. | by coupling the oxidation of organic substrates to a broad range of terminal electron acceptors (such as nitrate, metals and radionuclides), shewanella oneidensis mr-1 has the ability to produce current in microbial fuel cells (mfcs). omca, mtra, omcb (also known as mtrc), mtrb, and gspf are some known genes of s. oneidensis mr-1 that participate in the process of electron transfer. how does the cell coordinate the expression of these genes? to shed light on this problem, we obtain the gene expr ... | 2010 | 20492688 |
| a universal tagmodule collection for parallel genetic analysis of microorganisms. | systems-level analyses of non-model microorganisms are limited by the existence of numerous uncharacterized genes and a corresponding over-reliance on automated computational annotations. one solution to this challenge is to disrupt gene function using dna tag technology, which has been highly successful in parallelizing reverse genetics in saccharomyces cerevisiae and has led to discoveries in gene function, genetic interactions and drug mechanism of action. to extend the yeast dna tag methodol ... | 2010 | 20494978 |
| silver nanocrystallites: biofabrication using shewanella oneidensis, and an evaluation of their comparative toxicity on gram-negative and gram-positive bacteria. | microorganisms have long been known to develop resistance to metal ions either by sequestering metals inside the cell or by effluxing them into the extracellular media. here we report the biosynthesis of extracellular silver-based single nanocrystallites of well-defined composition and homogeneous morphology utilizing the gamma-proteobacterium, shewanella oneidensis mr-1, upon incubation with aqueous silver nitrate solution. further characterization of these particles revealed that the crystals ... | 2010 | 20509652 |
| shifts in the host range of a promiscuous plasmid through parallel evolution of its replication initiation protein. | the ability of bacterial plasmids to adapt to novel hosts and thereby shift their host range is key to their long-term persistence in bacterial communities. promiscuous plasmids of the incompatibility group p (incp)-1 can colonize a wide range of hosts, but it is not known if and how they can contract, shift or further expand their host range. to understand the evolutionary mechanisms of host range shifts of incp-1 plasmids, an incp-1β mini-replicon was experimentally evolved in four hosts in wh ... | 2010 | 20520653 |
| a versatile miniature bioreactor and its application to bioelectrochemistry studies. | often, reproducible investigations on bio-microsystems essentially require a flexible but well-defined experimental setup, which in its features corresponds to a bioreactor. we therefore developed a miniature bioreactor with a volume in the range of a few millilitre that is assembled by alternate stacking of individual polycarbonate elements and silicone gaskets. all the necessary supply pipes are incorporated as bore holes or cavities within the individual elements. their combination allows for ... | 2010 | 20537883 |
| nanoparticle decorated anodes for enhanced current generation in microbial electrochemical cells. | the development of highly efficient anode materials is critical for enhancing the current output of microbial electrochemical cells. in this study, au and pd nanoparticle decorated graphite anodes were developed and evaluated in a newly designed multi-anode microbial electrolysis cell (mec). the anodes decorated with au nanoparticles produced current densities up to 20-fold higher than plain graphite anodes by shewanella oneidensis mr-1, while those of pd-decorated anodes with similar morphologi ... | 2011 | 20542420 |
| characterization of the decaheme c-type cytochrome omca in solution and on hematite surfaces by small angle x-ray scattering and neutron reflectometry. | the outer membrane protein omca is an 85 kda decaheme c-type cytochrome located on the surface of the dissimilatory metal-reducing bacterium shewanella oneidensis mr-1. it is assumed to mediate shuttling of electrons to extracellular acceptors that include solid metal oxides such as hematite (alpha-fe(2)o(3)). no information is yet available concerning omca structure in physiologically relevant conditions such as aqueous environments. we purified omca and characterized its solution structure by ... | 2010 | 20550916 |
| methods for imaging shewanella oneidensis mr-1 nanofilaments. | nanofilament production by shewanella oneidensis mr-1 was evaluated as a function of lifestyle (planktonic vs. sessile) under aerobic and anaerobic conditions using different sample preparation techniques prior to imaging with scanning electron microscopy. nanofilaments could be imaged on mr-1 cells grown in biofilms or planktonically under both aerobic and anaerobic batch culture conditions after fixation, critical point drying and coating with a conductive metal. critical point drying was a re ... | 2010 | 20561956 |
| a support vector machine model for the prediction of proteotypic peptides for accurate mass and time proteomics. | the standard approach to identifying peptides based on accurate mass and elution time (amt) compares profiles obtained from a high resolution mass spectrometer to a database of peptides previously identified from tandem mass spectrometry (ms/ms) studies. it would be advantageous, with respect to both accuracy and cost, to only search for those peptides that are detectable by ms (proteotypic). | 2010 | 20568665 |
| standardized microbial fuel cell anodes of silica-immobilized shewanella oneidensis. | populations of metabolically active bacteria were associated at an electrode surface via vapor-deposition of silica to facilitate in situ characterization of bacterial physiology and bio-electrocatalytic activity in microbial fuel cells. | 2010 | 20574569 |
| constraint-based model of shewanella oneidensis mr-1 metabolism: a tool for data analysis and hypothesis generation. | shewanellae are gram-negative facultatively anaerobic metal-reducing bacteria commonly found in chemically (i.e., redox) stratified environments. occupying such niches requires the ability to rapidly acclimate to changes in electron donor/acceptor type and availability; hence, the ability to compete and thrive in such environments must ultimately be reflected in the organization and utilization of electron transfer networks, as well as central and peripheral carbon metabolism. to understand how ... | 2010 | 20589080 |
| in situ effective diffusion coefficient profiles in live biofilms using pulsed-field gradient nuclear magnetic resonance. | diffusive mass transfer in biofilms is characterized by the effective diffusion coefficient. it is well documented that the effective diffusion coefficient can vary by location in a biofilm. the current literature is dominated by effective diffusion coefficient measurements for distinct cell clusters and stratified biofilms showing this spatial variation. regardless of whether distinct cell clusters or surface-averaging methods are used, position-dependent measurements of the effective diffusion ... | 2010 | 20589671 |
| modularity of the mtr respiratory pathway of shewanella oneidensis strain mr-1. | summary four distinct pathways predicted to facilitate electron flow for respiration of externally located substrates are encoded in the genome of shewanella oneidensis strain mr-1. although the pathways share a suite of similar proteins, the activity of only two of these pathways has been described. respiration of extracellular substrates requires a mechanism to facilitate electron transfer from the quinone pool in the cytoplasmic membrane to terminal reductase enzymes located on the outer leaf ... | 2010 | 20598084 |
| shewanella knowledgebase: integration of the experimental data and computational predictions suggests a biological role for transcription of intergenic regions. | shewanellae are facultative gamma-proteobacteria whose remarkable respiratory versatility has resulted in interest in their utility for bioremediation of heavy metals and radionuclides and for energy generation in microbial fuel cells. extensive experimental efforts over the last several years and the availability of 21 sequenced shewanella genomes made it possible to collect and integrate a wealth of information on the genus into one public resource providing new avenues for making biological d ... | 2010 | 20627862 |
| the utility of shewanella japonica for microbial fuel cells. | shewanella-containing microbial fuel cells (mfcs) typically use the fresh water wild-type strain shewanella oneidensis mr-1 due to its metabolic diversity and facultative oxidant tolerance. however, s. oneidensis mr-1 is not capable of metabolizing polysaccharides for extracellular electron transfer. the applicability of shewanella japonica (an agar-lytic shewanella strain) for power applications was analyzed using a diverse array of carbon sources for current generation from mfcs, cellular phys ... | 2011 | 20663660 |
| phenotypic characterization of shewanella oneidensis mr-1 under aerobic and anaerobic growth conditions by using fourier transform infrared spectroscopy and high-performance liquid chromatography analyses. | shewanella oneidensis is able to conserve energy for growth by reducing a wide variety of terminal electron acceptors during anaerobic respiration, including several environmentally hazardous pollutants. this bacterium employs various electron transfer mechanisms for anaerobic respiration, including cell-bound reductases and secreted redox mediators. the aim of this study was to develop rapid tools for profiling the key metabolic changes associated with these different growth regimes and physiol ... | 2010 | 20675447 |
| mapping the subcellular proteome of shewanella oneidensis mr-1 using sarkosyl-based fractionation and lc-ms/ms protein identification. | a simple and effective subcellular proteomic method for fractionation based on osmotic lysis, differential centrifugation, and sarkosyl solubilization was applied to the gram-negative bacterium shewanella oneidensis to gain insight into its subcellular architecture. global differences in bacterial cytoplasm, inner membrane, periplasm, and outer membrane protein fractions were observed by sds page and heme staining, and tryptic peptides were analyzed using high-resolution liquid chromatography-ta ... | 2010 | 20690604 |
| to boost c-type cytochrome wire efficiency of electrogenic bacteria with fe3o4/au nanocomposites. | a significant increase (ca. 22-fold) in the electricity generation due to a shewanella oneidensis mr-1 biofilm was observed in the presence of fe(3)o(4)/au nanocomposites. | 2010 | 20717577 |
| a gold-sputtered carbon paper as an anode for improved electricity generation from a microbial fuel cell inoculated with shewanella oneidensis mr-1. | gold is among the highly conductive and stable materials, which are ideal anodes for microbial fuel cells (mfcs). however, previous studies have shown that bare gold surface is recalcitrant for the colonization of some exoelectrogens, e.g., shewanella putrefacians. in this work, the problem regarding the poor bio-compatibility of gold as an anode material was sorted out through coupling it with carbon paper. a new composite anode material was fabricated through sputtering gold layer homogeneousl ... | 2010 | 20801013 |
| an essential role for usha in processing of extracellular flavin electron shuttles by shewanella oneidensis. | the facultative anaerobe shewanella oneidensis can reduce a number of insoluble extracellular metals. direct adsorption of cells to the metal surface is not necessary, and it has been shown that s. oneidensis releases low concentrations flavins, including riboflavin and flavin mononucleotide (fmn), into the surrounding medium to act as extracellular electron shuttles. however, the mechanism of flavin release by shewanella remains unknown. we have conducted a transposon mutagenesis screen to iden ... | 2010 | 20807196 |
| probing electron transfer mechanisms in shewanella oneidensis mr-1 using a nanoelectrode platform and single-cell imaging. | microbial fuel cells (mfcs) represent a promising approach for sustainable energy production as they generate electricity directly from metabolism of organic substrates without the need for catalysts. however, the mechanisms of electron transfer between microbes and electrodes, which could ultimately limit power extraction, remain controversial. here we demonstrate optically transparent nanoelectrodes as a platform to investigate extracellular electron transfer in shewanella oneidensis mr-1, whe ... | 2010 | 20837546 |
| identification of in vivo hsp90-interacting proteins reveals modularity of hsp90 complexes is dependent on the environment in psychrophilic bacteria. | heat shock protein 90 (hsp90) is a conserved molecular chaperone that functions as part of complexes in which different client proteins target it to diverse sets of substrates. in this paper, hsp90 complexes were investigated in γ-proteobacteria from mild (shewanella oneidensis) and cold environments (shewanella frigidimarina and psychrobacter frigidicola), to determine changes in hsp90 interactions with client proteins in response to the adaptation to cold environments. hsp90 participation in c ... | 2010 | 20890740 |
| electrical transport along bacterial nanowires from shewanella oneidensis mr-1. | bacterial nanowires are extracellular appendages that have been suggested as pathways for electron transport in phylogenetically diverse microorganisms, including dissimilatory metal-reducing bacteria and photosynthetic cyanobacteria. however, there has been no evidence presented to demonstrate electron transport along the length of bacterial nanowires. here we report electron transport measurements along individually addressed bacterial nanowires derived from electron-acceptor-limited cultures ... | 2010 | 20937892 |
| solar-driven microbial photoelectrochemical cells with a nanowire photocathode. | we report a self-biased, solar-driven microbial photoelectrochemical cell (solar mpc) that can produce sustainable energy through coupling the microbial catalysis of biodegradable organic matter with solar energy conversion. the solar mpc consists of a p-type cuprous oxide nanowire-arrayed photocathode and an electricigen (shewanella oneidensis mr-1)-colonizing anode, which can harvest solar energy and bioenergy, respectively. the photocathode and bioanode are interfaced by matching the redox po ... | 2010 | 20939571 |
| the tricarboxylic acid cycle in shewanella oneidensis is independent of fur and ryhb control. | it is well established in e. coli and vibrio cholerae that strains harboring mutations in the ferric uptake regulator gene (fur) are unable to utilize tricarboxylic acid (tca) compounds, due to the down-regulation of key tca cycle enzymes, such as acna and sdhabcd. this down-regulation is mediated by a fur-regulated small regulatory rna named ryhb. it is unclear in the γ-proteobacterium s. oneidensis whether tca is also regulated by fur and ryhb. | 2010 | 20950482 |
| effects of engineered cerium oxide nanoparticles on bacterial growth and viability. | interest in engineered nanostructures has risen in recent years due to their use in energy conservation strategies and biomedicine. to ensure prudent development and use of nanomaterials, the fate and effects of such engineered structures on the environment should be understood. interactions of nanomaterials with environmental microorganisms are inevitable, but the general consequences of such interactions remain unclear, due to a lack of standard methods for assessing such interactions. therefo ... | 2010 | 20952651 |
| engineering of a synthetic electron conduit in living cells. | engineering efficient, directional electronic communication between living and nonliving systems has the potential to combine the unique characteristics of both materials for advanced biotechnological applications. however, the cell membrane is designed by nature to be an insulator, restricting the flow of charged species; therefore, introducing a biocompatible pathway for transferring electrons across the membrane without disrupting the cell is a significant challenge. here we describe a geneti ... | 2010 | 20956333 |
| phage-induced lysis enhances biofilm formation in shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is capable of forming highly structured surface-attached communities. by dnase i treatment, we demonstrated that extracellular dna (edna) serves as a structural component in all stages of biofilm formation under static and hydrodynamic conditions. we determined whether edna is released through cell lysis mediated by the three prophages lambdaso, muso1 and muso2 that are harbored in the genome of s. oneidensis mr-1. mutant analyses and infection studies revealed that al ... | 2010 | 20962878 |
| shewanella oneidensis in a lactate-fed pure-culture and a glucose-fed co-culture with lactococcus lactis with an electrode as electron acceptor. | bioelectrochemical systems (bess) employing mixed microbial communities as biocatalysts are gaining importance as potential renewable energy, bioremediation, or biosensing devices. while we are beginning to understand how individual microbial species interact with an electrode as electron donor, little is known about the interactions between different microbial species in a community: sugar fermenting bacteria can interact with current producing microbes in a fashion that is either neutral, posi ... | 2010 | 21036604 |
| viability and metal reduction of shewanella oneidensis mr-1 under co2 stress: implications for ecological effects of co2 leakage from geologic co2 sequestration. | to study potential ecological impacts of co(2) leakage to shallow groundwater and soil/sediments from geologic co(2) sequestration (gcs) sites, this work investigated the viability and metal reduction of shewanella oneidensis mr-1 under co(2) stress. while mr-1 could grow under high-pressure nitrogen gas (500 psi), the mix of 1% co(2) with n(2) at total pressures of 15 or 150 psi significantly suppressed the growth of mr-1, compared to the n(2) control. when co(2) partial pressures were over 15 ... | 2010 | 21058700 |
| enabling unbalanced fermentations by using engineered electrode-interfaced bacteria. | cellular metabolism is a series of tightly linked oxidations and reductions that must be balanced. recycling of intracellular electron carriers during fermentation often requires substrate conversion to undesired products, while respiration demands constant addition of electron acceptors. the use of electrode-based electron acceptors to balance biotransformations may overcome these constraints. to test this hypothesis, the metal-reducing bacterium shewanella oneidensis was engineered to stoichio ... | 2010 | 21060736 |
| pellicle formation in shewanella oneidensis. | although solid surface-associated biofilm development of s. oneidensis has been extensively studied in recent years, pellicles formed at the air-liquid interface are largely overlooked. the goal of this work was to understand basic requirements and mechanism of pellicle formation in s. oneidensis. | 2010 | 21080927 |
| crystal structure of a prokaryotic homologue of the mammalian oligopeptide-proton symporters, pept1 and pept2. | pept1 and pept2 are major facilitator superfamily (mfs) transporters that utilize a proton gradient to drive the uptake of di- and tri-peptides in the small intestine and kidney, respectively. they are the major routes by which we absorb dietary nitrogen and many orally administered drugs. here, we present the crystal structure of pept(so), a functionally similar prokaryotic homologue of the mammalian peptide transporters from shewanella oneidensis. this structure, refined using data up to 3.6 å ... | 2010 | 21131908 |
| an innovative miniature microbial fuel cell fabricated using photolithography. | recently microbial fuel cells (mfcs) have attracted increasing interests in both environmental and energy fields. among the various mfc configurations, miniature microbial fuel cell (mini-mfc) has a great potential for the application in medical, communication and other areas because of its miniature volume and high output power density. in this work, a 25-μl single-chamber mini-mfc was fabricated using the photolithography technique. the plate-shaped gold anodic electrode in the mini-mfc showed ... | 2010 | 21169010 |
| involvement of the shewanella oneidensis decaheme cytochrome mtra in the periplasmic stability of the beta-barrel protein mtrb. | the shewanella oneidensis outer membrane β-barrel protein mtrb is part of a membrane-spanning protein complex (mtrabc) which is necessary for dissimilatory iron reduction. quantitative pcr, heterologous gene expression, and mutant studies indicated that mtra is required for periplasmic stability of mtrb. degp depletion compensated for this mtra dependence. | 2010 | 21169449 |
| current production by bacterial communities in microbial fuel cells enriched from wastewater sludge with different electron donors. | electricity production by bacterial communities enriched from wastewater sludge with lactate, succinate, n-acetyl-d-glucosamine (nag), acetate, formate, and uridine were monitored in dual-chamber microbial fuel cells (mfcs). stable electricity production was observed after 300 h for communities enriched from lactate, acetate, and formate, while communities enriched with succinate, nag, and uridine stabilized only after 700 h. the average peak current densities and maximum power densities generat ... | 2010 | 21171663 |
| shewanella oneidensis mr-1 chemotaxis in a diffusion gradient chamber. | to obtain a systems-level understanding of shewanella biology and ecology, the influence of electron acceptor availability on shewanella's growth, metabolism, and transport needs to be elucidated. the diffusion gradient chamber (dgc) is an experimental tool developed to study population-level microbial growth and motility in response to concentration gradients. in this paper, the response of populations of shewanella oneidensis mr-1 cells to an applied single gradient of the electron acceptor fu ... | 2010 | 21174460 |
| the octahaem sira catalyses dissimilatory sulfite reduction in shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is a metal reducer that uses a large number of electron acceptors including thiosulfate, polysulfide and sulfite. the enzyme required for thiosulfate and polysulfide respiration has been recently identified, but the mechanisms of sulfite reduction remained unexplored. analysis of mr-1 cultures grown anaerobically with sulfite suggested that the dissimilatory sulfite reductase catalyses six-electron reduction of sulfite to sulfide. reduction of sulfite required menaquin ... | 2011 | 21199252 |