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cell-secreted flavins bound to membrane cytochromes dictate electron transfer reactions to surfaces with diverse charge and ph.the variety of solid surfaces to and from which microbes can deliver electrons by extracellular electron transport (eet) processes via outer-membrane c-type cytochromes (om c-cyts) expands the importance of microbial respiration in natural environments and industrial applications. here, we demonstrate that the bifurcated eet pathway of om c-cyts sustains the diversity of the eet surface in shewanella oneidensis mr-1 via specific binding with cell-secreted flavin mononucleotide (fmn) and riboflav ...201425012073
managing oxidative stresses in shewanella oneidensis: intertwined roles of the oxyr and ohrr regulons.shewanella oneidensis, renowned for its remarkable respiratory abilities, inhabit redox-stratified environments prone to reactive oxygen species (ros)formation. two major oxidative stress regulators,analogues of oxyr and ohrr, specifically respond to h(2)o(2) and organic peroxides (op), respectively, are encoded in the genome based on sequence comparison to well-studied models. presumably, these analogues provide protection from ros. an understanding of s. oneidensis oxyr has been established re ...201425009841
conservation of transcription start sites within genes across a bacterial genus.transcription start sites (tsss) lying inside annotated genes, on the same or opposite strand, have been observed in diverse bacteria, but the function of these unexpected transcripts is unclear. here, we use the metal-reducing bacterium shewanella oneidensis mr-1 and its relatives to study the evolutionary conservation of unexpected tsss. using high-resolution tiling microarrays and 5'-end rna sequencing, we identified 2,531 tsss in s. oneidensis mr-1, of which 18% were located inside coding se ...201424987095
possible dynamically gated conductance along heme wires in bacterial multiheme cytochromes.the staggered cross decaheme configuration of electron transfer cofactors in the outer-membrane cytochrome mtrf serves as a prototype for conformationally gated multiheme electron transport. derived from the bacterium shewanella oneidensis, the staggered cross configuration reveals intersecting c-type octaheme and tetraheme "wires" containing thermodynamic "hills" and "valleys" (proc. natl. acad. sci. u. s. a. 2014, 11, 611-616), suggesting that the protein structure may include a dynamical mech ...201424975678
iron triggers λso prophage induction and release of extracellular dna in shewanella oneidensis mr-1 biofilms.prophages are ubiquitous elements within bacterial chromosomes and affect host physiology and ecology in multiple ways. we have previously demonstrated that phage-induced lysis is required for extracellular dna (edna) release and normal biofilm formation in shewanella oneidensis mr-1. here, we investigated the regulatory mechanisms of prophage λso spatiotemporal induction in biofilms. to this end, we used a functional fluorescence fusion to monitor λso activation in various mutant backgrounds an ...201424951794
colorimetric detection of shewanella oneidensis based on immunomagnetic capture and bacterial intrinsic peroxidase activity.rapid detection and enumeration of target microorganisms is considered as a powerful tool for monitoring bioremediation process that typically involves cleaning up polluted environments with functional microbes. a novel colorimetric assay is presented based on immunomagnetic capture and bacterial intrinsic peroxidase activity for rapidly detecting shewanella oneidensis, an important model organism for environmental bioremediation because of its remarkably diverse respiratory abilities. analyte b ...201424898751
photoenhanced electrochemical interaction between shewanella and a hematite nanowire photoanode.here we report the investigation of interplay between light, a hematite nanowire-arrayed photoelectrode, and shewanella oneidensis mr-1 in a solar-assisted microbial photoelectrochemical system (solar mps). whole cell electrochemistry and microbial fuel cell (mfc) characterization of shewanella oneidensis strain mr-1 showed that these cells cultured under (semi)anaerobic conditions expressed substantial c-type cytochrome outer membrane proteins, exhibited well-defined redox peaks, and generated ...201424875432
microbial nanowires for bioenergy applications.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 e ...201424863901
promotion and nucleation of carbonate precipitation during microbial iron reduction.iron-bearing early diagenetic carbonate cements are common in sedimentary rocks, where they are thought to be associated with microbial iron reduction. however, little is yet known about how local environments around actively iron-reducing cells affect carbonate mineral precipitation rates and compositions. precipitation experiments with the iron-reducing bacterium shewanella oneidensis mr-1 were conducted to examine the potential role of cells in promoting precipitation and to explore the possi ...201424862734
facile method to stain the bacterial cell surface for super-resolution fluorescence microscopy.a method to fluorescently stain the surfaces of both gram-negative and gram-positive bacterial cells compatible with super-resolution fluorescence microscopy is presented. this method utilizes a commercially-available fluorescent probe to label primary amines at the surface of the cell. we demonstrate efficient staining of two bacterial strains, the gram-negative shewanella oneidensis mr-1 and the gram-positive bacillus subtilis 168. using structured illumination microscopy and stochastic optica ...201424816810
sulfur-mediated electron shuttling during bacterial iron reduction.microbial reduction of ferric iron [fe(iii)] is an important biogeochemical process in anoxic aquifers. depending on groundwater ph, dissimilatory metal-reducing bacteria can also respire alternative electron acceptors to survive, including elemental sulfur (s(0)). to understand the interplay of fe/s cycling under alkaline conditions, we combined thermodynamic geochemical modeling with bioreactor experiments using shewanella oneidensis mr-1. under these conditions, s. oneidensis can enzymaticall ...201424789972
the x-ray crystal structure of shewanella oneidensis omca reveals new insight at the microbe-mineral interface.the x-ray crystal structure of shewanella oneidensis omca, an extracellular decaheme cytochrome involved in mineral reduction, was solved to a resolution of 2.7 å. the four omca molecules in the asymmetric unit are arranged so the minimum distance between heme 5 on adjacent omca monomers is 9 å, indicative of a transient omca dimer capable of intermolecular electron transfer. a previously identified hematite binding motif was identified near heme 10, forming a hydroxylated surface that would bri ...201424747425
d-optcom: dynamic multi-level and multi-objective metabolic modeling of microbial communities.most microbial communities change with time in response to changes and/or perturbations in environmental conditions. temporal variations in interspecies metabolic interactions within these communities can significantly affect their structure and function. here, we introduce d-optcom, an extension of the optcom procedure, for the dynamic metabolic modeling of microbial communities. it enables capturing the temporal dynamics of biomass concentration of the community members and extracellular conce ...201424742179
two residues predominantly dictate functional difference in motility between shewanella oneidensis flagellins flaa and flab.nearly half of flagellated microorganisms possess a multiple-flagellin system. although a functional filament can be formed from one of multiple flagellins alone in many bacteria, it is more common that one flagellin is the major constituent and others contribute. underlying mechanisms proposed for such scenarios cover flagellin regulation of various levels, including transcription, translation, post-translational modification, secretion, and filament assembly. in shewanella oneidensis, the flag ...201424733391
innovative statistical interpretation of shewanella oneidensis microbial fuel cells data.the last decade of research has made significant strides toward practical applications of microbial fuel cells (mfcs); however, design improvements and operational optimization cannot be realized without equally considering engineering designs and biological interfacial reactions. in this study, the main factors contributing to mfcs' overall performance and their influence on mfc reproducibility are discussed. two statistical approaches were used to create a map of mfc components and their expan ...201424691574
evidence for function overlapping of cyma and the cytochrome bc1 complex in the shewanella oneidensis nitrate and nitrite respiration.shewanella oneidensis is an important model organism for its versatility of anaerobic respiration. cyma, a cytoplasmic membrane-bound tetraheme c-type cytochrome, plays a central role in anaerobic respiration by transferring electrons from the quinone pool to a variety of terminal reductases. although loss of cyma results in defect in respiration of many electron acceptors (eas), a significant share of the capacity remains in general. in this study, we adopted a transposon random mutagenesis met ...201424650148
shewanella oneidensis cytochrome c nitrite reductase (ccnir) does not disproportionate hydroxylamine to ammonia and nitrite, despite a strongly favorable driving force.cytochrome c nitrite reductase (ccnir) from shewanella oneidensis, which catalyzes the six-electron reduction of nitrite to ammonia in vivo, was shown to oxidize hydroxylamine in the presence of large quantities of this substrate, yielding nitrite as the sole free nitrogenous product. uv-visible stopped-flow and rapid-freeze-quench electron paramagnetic resonance data, along with product analysis, showed that the equilibrium between hydroxylamine and nitrite is fairly rapidly established in the ...201424645742
highly active bidirectional electron transfer by a self-assembled electroactive reduced-graphene-oxide-hybridized biofilm.low extracellular electron transfer performance is often a bottleneck in developing high-performance bioelectrochemical systems. herein, we show that the self-assembly of graphene oxide and shewanella oneidensis mr-1 formed an electroactive, reduced-graphene-oxide-hybridized, three-dimensional macroporous biofilm, which enabled highly efficient bidirectional electron transfers between shewanella and electrodes owing to high biomass incorporation and enhanced direct contact-based extracellular el ...201424644059
functional expression of carassius auratus cytochrome p4501a in a novel shewanella oneidensis expression system and application for the degradation of benzo[a]pyrene.cytochrome p4501a (cyp1a) in fish has attracted an increasing interest because of its important roles in the metabolic activation of certain xenobiotics such as aromatic hydrocarbons. cyps are reported to be expressed in yeast, insect cells and escherichia coli, but are critical for high-level expression. besides, this study found that the purification of recombinant goldfish cyp1a would result in a loss of enzyme activity. because large quantities of functional cyp1a are required, it is necessa ...201424637371
the impact of enzyme orientation and electrode topology on the catalytic activity of adsorbed redox enzymes.it is well established that the structural details of electrodes and their interaction with adsorbed enzyme influences the interfacial electron transfer rate. however, for nanostructured electrodes, it is likely that the structure also impacts on substrate flux near the adsorbed enzymes and thus catalytic activity. furthermore, for enzymes converting macro-molecular substrates it is possible that the enzyme orientation determines the nature of interactions between the adsorbed enzyme and substra ...201324634538
cell growth and protein expression of shewanella oneidensis in biofilms and hydrogel-entrapped cultures.the performance of biofilm-based bioprocesses is difficult to predict and control because of the intrinsic heterogeneous and dynamic properties of microbial biofilms. biofilm mimics, such as microbial cells entrapped in polymeric scaffolds that are permeable for nutrients, have been proposed to replace real biofilms to achieve long-term robust performance in engineering applications. however, the physiological differences between cells that are physically entrapped in a synthetic polymeric matri ...201424626808
comparisons of shewanella strains based on genome annotations, modeling, and experiments.shewanella is a genus of facultatively anaerobic, gram-negative bacteria that have highly adaptable metabolism which allows them to thrive in diverse environments. this quality makes them an attractive bacterial target for research in bioremediation and microbial fuel cell applications. constraint-based modeling is a useful tool for helping researchers gain insights into the metabolic capabilities of these bacteria. however, shewanella oneidensis mr-1 is the only strain with a genome-scale metab ...201424621294
signatures for mass spectrometry data quality.ensuring data quality and proper instrument functionality is a prerequisite for scientific investigation. manual quality assurance is time-consuming and subjective. metrics for describing liquid chromatography mass spectrometry (lc-ms) data have been developed; however, the wide variety of lc-ms instruments and configurations precludes applying a simple cutoff. using 1150 manually classified quality control (qc) data sets, we trained logistic regression classification models to predict whether a ...201424611607
uranium reduction by shewanella oneidensis mr-1 as a function of nahco3 concentration: surface complexation control of reduction kinetics.it is crucial to determine the controls on the kinetics of u(vi) bioreduction in order to understand and model the fate and mobility of u in groundwater systems and also to enhance the effectiveness of u bioremediation strategies. in this study, we measured the rate of u(vi) reduction by shewanella oneidensis strain mr-1 as function of nahco3 concentration. the experiments demonstrate that increasing concentrations of nahco3 in the system lead to slower u(vi) reduction kinetics. the nahco3 conce ...201424576101
characterization of microbial current production as a function of microbe-electrode-interaction.microbe-electrode-interactions are keys for microbial fuel cell technology. nevertheless, standard measurement routines to analyze the interplay of microbial physiology and material characteristics have not been introduced yet. in this study, graphite anodes with varying surface properties were evaluated using pure cultures of shewanella oneidensis and geobacter sulfurreducens, as well as defined and undefined mixed cultures. the evaluation routine consisted of a galvanostatic period, a current ...201424566287
a biochemical approach to study the role of the terminal oxidases in aerobic respiration in shewanella oneidensis mr-1.the genome of the facultative anaerobic γ-proteobacterium shewanella oneidensis mr-1 encodes for three terminal oxidases: a bd-type quinol oxidase and two heme-copper oxidases, a a-type cytochrome c oxidase and a cbb 3-type oxidase. in this study, we used a biochemical approach and directly measured oxidase activities coupled to mass-spectrometry analysis to investigate the physiological role of the three terminal oxidases under aerobic and microaerobic conditions. our data revealed that the cbb ...201424466040
improving the efficiency of plasmid transformation in shewanella oneidensis mr-1 by removing clai restriction site.here we demonstrate that elimination of clai restriction site from the sequence of a plasmid dna increases the efficiency of transformation of shewanella oneidensis mr-1 significantly. to achieve reliable transformation of s. oneidensis mr-1 plasmids either lacking clai site or isolated from primary transformants of s. oneidensis should be used.201424462975
[research on the bioaccesibility of hgs by shewanella oneidensis mr-1].the biological dissolution and methylation of solid hgs by shewanella oneidensis mr-1 and influenced factors under laboratory conditions were studied. results showed that s. oneidensis mr-1 could grow well at the low concentration of na2s, but its growth was inhibited at the high concentration of na2s, which mainly happened in the prolonged lag phase. iron reducing bacteria s. oneidensis mr-1 could access the solid mercuric sulfide, and rapidly promote the biological dissolution and methylation ...201324455961
tolerance of anaerobic bacteria to chlorinated solvents.the aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (cahs), perchloroethene (pce), carbon tetrachloride (ct), chloroform (cf) and 1,2-dichloroethane (1,2-dca), on the growth of eight anaerobic bacteria: four fermentative species (escherichia coli, klebsiella sp., clostridium sp. and paenibacillus sp.) and four respiring species (pseudomonas aeruginosa, geobacter sulfurreducens, shewanella oneidensis and desulfovibrio vulgaris). effective concentrations ...201424441515
selenite reduction by shewanella oneidensis mr-1 is mediated by fumarate reductase in periplasm.in situ reduction of selenite to elemental selenium (se(0)), by microorganisms in sediments and soils is an important process and greatly affects the environmental distribution and the biological effects of selenium. however, the mechanism behind such a biological process remains unrevealed yet. here we use shewanella oneidensis mr-1, a widely-distributed dissimilatory metal-reducing bacterium with a powerful and diverse respiration capability, to evaluate the involvement of anaerobic respiratio ...201424435070
a stable synergistic microbial consortium for simultaneous azo dye removal and bioelectricity generation.microbial species coexist in natural or engineered settings, where they encounter extensive competition and cooperation. interactions occurring through metabolite exchange or direct contact might be important in establishment of functional biodegradation consortium. understanding these interactions can facilitate manipulation of selected communities and exploitation of their capacity for specific industrial applications. here, a simple dual-species consortium (pseudomonas putida and shewanella o ...201424434696
metabolically engineered glucose-utilizing shewanella strains under anaerobic conditions.comparative genome analysis of shewanella strains predicted that the strains metabolize preferably two- and three-carbon carbohydrates as carbon/electron source because many shewanella genomes are deficient of the key enzymes in glycolysis (e.g., glucokinase). in addition, all shewanella genomes are known to have only one set of genes associated with the phosphotransferase system required to uptake sugars. to engineer shewanella strains that can utilize five- and six-carbon carbohydrates, we con ...201424384311
contributions of the [nife]- and [fefe]-hydrogenase to h2 production in shewanella oneidensis mr-1 as revealed by isotope ratio analysis of evolved h(2).shewanella oneidensis mr-1 encodes both a [nife]- and an [fefe]-hydrogenase. while the output of these proteins has been characterized in mutant strains expressing only one of the enzymes, the contribution of each to h2 synthesis in the wild-type organism is not clear. here, we use stable isotope analysis of h2 in the culture headspace, along with transcription data and measurements of the concentrations of gases in the headspace, to characterize h2 production in the wild-type strain. after most ...201424372594
disruption of putrescine biosynthesis in shewanella oneidensis enhances biofilm cohesiveness and performance in cr(vi) immobilization.although biofilm-based bioprocesses have been increasingly used in various applications, the long-term robust and efficient biofilm performance remains one of the main bottlenecks. in this study, we demonstrated that biofilm cohesiveness and performance of shewanella oneidensis can be enhanced through disrupting putrescine biosynthesis. through random transposon mutagenesis library screening, one hyperadherent mutant strain, cp2-1-s1, exhibiting an enhanced capability in biofilm formation, was o ...201424362428
biomog: a computational framework for the de novo generation or modification of essential biomass components.the success of genome-scale metabolic modeling is contingent on a model's ability to accurately predict growth and metabolic behaviors. to date, little focus has been directed towards developing systematic methods of proposing, modifying and interrogating an organism's biomass requirements that are used in constraint-based models. to address this gap, the biomass modification and generation (biomog) framework was created and used to generate lists of biomass components de novo, as well as to mod ...201324339916
roles of unda and mtrc of shewanella putrefaciens w3-18-1 in iron reduction.the completion of genome sequencing in a number of shewanella species, which are most renowned for their metal reduction capacity, offers a basis for comparative studies. previous work in shewanella oneidensis mr-1 has indicated that some genes within a cluster (mtrbac-omca-mtrfed) were involved in iron reduction. to explore new features of iron reduction pathways, we experimentally analyzed shewanella putrefaciens w3-18-1 since its gene cluster is considerably different from that of mr-1 in tha ...201324274142
molecular mechanisms of heme based sensors from sediment organisms capable of extracellular electron transfer.bioelectrochemical systems (bes) rely on the metabolism of sediment bacteria capable of forming electrogenic biofilms to generate electrical work. the environment across the thickness of the biofilm is variable and in order for the cells to maintain their viability they require molecular sensors that allow them to adapt their metabolism to their respective environment. the dcra sensor from desulfovibrio vulgaris and the gsu 0582 and 0935 sensor domains from geobacter sulfurreducens appear to fun ...201424268904
effects of bio-au nanoparticles on electrochemical activity of shewanella oneidensis wild type and δomca/mtrc mutant.both shewanella oneidensis mr-1 wild type and its mutant δomca/mtrc are capable of transforming au(iii) into au nanoparticles (aunps). cyclic voltammetry reveals a decrease in redox current after the wild type is exposed to au(iii) but an increase in oxidation current for the mutant. the peak current of the wild type is much higher than that of the mutant before the exposure of au(iii), but lower than that of the mutant after the formation of aunps. this suggests that damage to the electron tran ...201324264440
promotion of iron oxide reduction and extracellular electron transfer in shewanella oneidensis by dmso.the dissimilatory metal reducing bacterium shewanella oneidensis mr-1, known for its capacity of reducing iron and manganese oxides, has great environmental impacts. the iron oxides reducing process is affected by the coexistence of alternative electron acceptors in the environment, while investigation into it is limited so far. in this work, the impact of dimethyl sulphoxide (dmso), a ubiquitous chemical in marine environment, on the reduction of hydrous ferric oxide (hfo) by s. oneidensis mr-1 ...201324244312
biogenic tellurium nanorods as a novel antivirulence agent inhibiting pyoverdine production in pseudomonas aeruginosa.while antibiotic resistance in bacteria is rapidly increasing, the development of new antibiotics has decreased in recent years. antivirulence drugs disarming rather than killing pathogens have been proposed to alleviate the problem of resistance inherent to existing biocidal antibiotics. here, we report a nontoxic biogenic nanomaterial as a novel antivirulence agent to combat bacterial infections caused by pseudomonas aeruginosa. we synthesized, in an environmentally benign fashion, tellurium n ...201424222554
phosphorylation-dependent derepression by the response regulator hnoc in the shewanella oneidensis nitric oxide signaling network.nitric oxide (no) is an important signaling molecule that regulates diverse physiological processes in all domains of life. in many gammaproteobacteria, no controls behavioral responses through a complex signaling network involving heme-nitric oxide/oxygen binding (h-nox) domains as selective no sensors. in shewanella oneidensis, h-nox-mediated no sensing increases biofilm formation, which is thought to serve as a protective mechanism against no cytotoxicity. the h-nox/no-responsive (hno) signal ...201324218564
protection from oxidative stress relies mainly on derepression of oxyr-dependent katb and dps in shewanella oneidensis.shewanella thrives in redox-stratified environments where accumulation of h2o2 becomes inevitable because of the chemical oxidation of reduced metals, sulfur species, or organic molecules. as a research model, the representative species shewanella oneidensis has been extensively studied for its response to various stresses. however, little progress has been made toward an understanding of the physiological and genetic responses of this bacterium to oxidative stress, which is critically relevant ...201424214945
identification of a molecular signature unique to metal-reducing gammaproteobacteria.functional genes required for microbial (dissimilatory) metal reduction display high sequence divergence, which limits their utility as molecular biomarkers for tracking the presence and activity of metal-reducing bacteria in natural and engineered systems. in the present study, homologs of the outer membrane beta-barrel protein mtrb of metal-reducing gammaproteobacteria were found to contain a unique n-terminal cxxc motif that was missing from mtrb homologs of nonmetal-reducing gammaproteobacte ...201424188569
the impact of ionic mercury on antioxidant defenses in two mercury-sensitive anaerobic bacteria.while the toxicological effects of mercury (hg) are well studied in mammals, little is known about the mechanisms of toxicity to bacterial cells lacking an hg resistance (mer) operon. we determined that shewanella oneidensis mr-1 is more sensitive to ionic mercury [hg(ii)] under aerobic conditions than in fumarate reducing conditions, with minimum inhibitory concentrations of 0.25 and 2 μm respectively. this increased sensitivity in aerobic conditions is not due to increased import, as more hg i ...201324150569
quinone-mediated microbial synthesis of reduced graphene oxide with peroxidase-like activity.the effects of different quinones on graphene oxide (go) reduction by shewanella oneidensis mr-1 and the peroxidase activity of the resultant reduced graphene oxide (qrgo) were studied. the presence of 100 μm anthraquinone-2-sulfonate (aqs), anthraquinone-2,6-disulfonate and 5-hydroxy-1,4-naphthoquinone could lead to 1.6-2.8-fold increase in go reduction rate, whereas anthraquinone-2-carboxylate slowed down the reduction. the stimulating effects of aqs increased with the increase of its concentr ...201324140856
oxygen allows shewanella oneidensis mr-1 to overcome mediator washout in a continuously fed bioelectrochemical system.many bioelectrochemical systems (bess) harness the ability of electrode-active microbes to catalyze reactions between electrodes and chemicals, often to perform useful functions such as wastewater treatment, fuel production, and biosensing. a microbial fuel cell (mfc) is one type of bes, which generates electric power through microbial respiration with an anode as the electron acceptor, and typically with oxygen reduction at the cathode to provide the terminal electron acceptor. oxygen intrusion ...201424122485
modeling biofilms with dual extracellular electron transfer mechanisms.electrochemically active biofilms have a unique form of respiration in which they utilize solid external materials as terminal electron acceptors for their metabolism. currently, two primary mechanisms have been identified for long-range extracellular electron transfer (eet): a diffusion- and a conduction-based mechanism. evidence in the literature suggests that some biofilms, particularly shewanella oneidensis, produce the requisite components for both mechanisms. in this study, a generic model ...201324113651
"replica-extraction-transfer" nanostructure-initiator mass spectrometry imaging of acoustically printed bacteria.traditionally, microbes are studied under controlled laboratory conditions as isolates in planktonic culture. however, this is a vast extrapolation from their natural state; development of new techniques is required to decipher the largely unknown world of microbial chemical interactions in more realistic environments. the field of mass spectrometry imaging has made significant progress in localizing metabolites in and around bacterial colonies, primarily by using maldi and esi-based techniques ...201324111681
description of a riboflavin biosynthetic gene variant prevalent in the phylum proteobacteria.riboflavin (vitamin b2) is the precursor of flavin mononucleotide and flavin adenine dinucleotide, which are cofactors essential for a host of intracellular redox reactions. microorganisms synthesize flavins de novo to fulfill nutritional requirements, but it is becoming increasingly clear that flavins play a wider role in cellular physiology than was previously appreciated. flavins mediate diverse processes beyond the cytoplasmic membrane, including iron acquisition, extracellular respiration, ...201324097946
changes in translational efficiency is a dominant regulatory mechanism in the environmental response of bacteria.to understand how cell physiological state affects mrna translation, we used shewanella oneidensis mr-1 grown under steady state conditions at either 20% or 8.5% o2. using a combination of quantitative proteomics and rna-seq, we generated high-confidence data on >1000 mrna and protein pairs. by using a steady state model, we found that differences in protein-mrna ratios were primarily due to differences in the translational efficiency of specific genes. when oxygen levels were lowered, 28% of th ...201324081429
h₂-dependent azoreduction by shewanella oneidensis mr-1: involvement of secreted flavins and both [ni-fe] and [fe-fe] hydrogenases.in this paper, the hydrogen (h2)-dependent discoloration of azo dye amaranth by shewanella oneidensis mr-1 was investigated. experiments with hydrogenase-deficient strains demonstrated that periplasmic [ni-fe] hydrogenase (hyab) and periplasmic [fe-fe] hydrogenase (hyda) are both respiratory hydrogenases of dissimilatory azoreduction in s. oneidensis mr-1. these findings suggest that hyab and hyda can function as uptake hydrogenases that couple the oxidation of h2 to the reduction of amaranth to ...201424081321
combined geochemical and electrochemical methodology to quantify corrosion of carbon steel by bacterial activity.the availability of respiratory substrates, such as h2 and fe(ii,iii) solid corrosion products within nuclear waste repository, will sustain the activities of hydrogen-oxidizing bacteria (hob) and iron-reducing bacteria (irb). this may have a direct effect on the rate of carbon steel corrosion. this study investigates the effects of shewanella oneidensis (an hob and irb model organism) on the corrosion rate by looking at carbon steel dissolution in the presence of h2 as the sole electron donor. ...201424064199
electrode assemblies composed of redox cascades from microbial respiratory electron transfer chains.respiratory and photosynthetic electron transfer chains are dependent on vectorial electron transfer through a series of redox proteins. examples include electron transfer from napc to napab nitrate reductase in paracoccus denitrificans and from cyma to fcc3 (flavocytochrome c3) fumarate reductase in shewanella oneidensis mr-1. in the present article, we demonstrate that graphite electrodes can serve as surfaces for the stepwise adsorption of napc and napab, and the stepwise adsorption of cyma a ...201324059515
high power density microbial fuel cell with flexible 3d graphene-nickel foam as anode.the structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (mfcs). in this study, we developed a three-dimensional (3d) reduced graphene oxide-nickel (denoted as rgo-ni) foam as an anode for mfc through controlled deposition of rgo sheets onto the nickel foam substrate. the loading amount of rgo sheets and electrode surface area can be controlled by the number of rgo loading cycles. 3d rgo-ni foam anode provides not only a large acc ...201324057049
metabolic profiling directly from the petri dish using nanospray desorption electrospray ionization imaging mass spectrometry.understanding molecular interaction pathways in complex biological systems constitutes a treasure trove of knowledge that might facilitate the specific, chemical manipulation of the countless microbiological systems that occur throughout our world. however, there is a lack of methodologies that allow the direct investigation of chemical gradients and interactions in living biological systems, in real time. here, we report the use of nanospray desorption electrospray ionization (nanodesi) imaging ...201324047514
unique organizational and functional features of the cytochrome c maturation system in shewanella oneidensis.shewanella are renowned for their ability to respire on a wide range of electron acceptors, which has been partially accredited to the presence of a large number of the c-type cytochromes. in the model species s. oneidensis mr-1, at least 41 genes encode c-type cytochromes that are predicted to be intact, thereby likely functional. previously, in-frame deletion mutants for 36 of these genes were obtained and characterized. in this study, first we completed the construction of an entire set of c- ...201324040415
analyzing the modification of the shewanella oneidensis mr-1 flagellar filament.the unsheathed flagellar filament of shewanella oneidensis mr-1 is composed of two highly homologous flagellins, flaa, and the major structural unit, flab. we identified a gene cluster, so_3261-so_3265 (now sfmabcde), that is required for the formation of a fully functional filament and for motility. the predicted function of the corresponding gene products strongly indicated a role in flagellin modification. accordingly, loss of sfmabcde results in a significant mass shift of both flaa and flab ...201324039942
bacterial-fungal interactions enhance power generation in microbial fuel cells and drive dye decolourisation by an ex situ and in situ electro-fenton process.in this work, the potential for sustainable energy production from wastes has been exploited using a combination fungus-bacterium in microbial fuel cell (mfc) and electro-fenton technology. the fungus trametes versicolor was grown with shewanella oneidensis so that the bacterium would use the networks of the fungus to transport the electrons to the anode. this system generated stable electricity that was enhanced when the electro-fenton reactions occurred in the cathode chamber. this configurati ...201324035817
self-biased solar-microbial device for sustainable hydrogen generation.here we demonstrate the feasibility of continuous, self-sustained hydrogen gas production based solely on solar light and biomass (wastewater) recycling, by coupling solar water splitting and microbial electrohydrogenesis in a photoelectrochemical cell-microbial fuel cell (pec-mfc) hybrid device. the pec device is composed of a tio2 nanowire-arrayed photoanode and a pt cathode. the mfc is an air cathode dual-chamber device, inoculated with either shewanella oneidensis mr-1 (batch-fed on artifici ...201324025029
graphene oxide as nanogold carrier for ultrasensitive electrochemical immunoassay of shewanella oneidensis with silver enhancement strategy.the genus shewanella is ubiquitous in environment and has been extensively studied for their applications in bioremediation. a novel immunoassay for ultrasensitive detection of shewanella oneidensis was presented based on graphene oxide (go) as nanogold carrier with silver enhancement strategy. the enhanced sensitivity was achieved by employing conjugate-featuring gold nanoparticles (aunps) and antibodies (ab) assembled on bovine serum albumin (bsa)-modified go (ab/aunps/bsa/go). after a sandwic ...201424016538
generalized bacterial genome editing using mobile group ii introns and cre-lox.efficient bacterial genetic engineering approaches with broad-host applicability are rare. we combine two systems, mobile group ii introns ('targetrons') and cre/lox, which function efficiently in many different organisms, into a versatile platform we call getr (genome editing via targetrons and recombinases). the introns deliver lox sites to specific genomic loci, enabling genomic manipulations. efficiency is enhanced by adding flexibility to the rna hairpins formed by the lox sites. we use the ...201324002656
efficacy of a 3rd generation high-throughput sequencing platform for analyses of 16s rrna genes from environmental samples.longer sequences of the bacterial 16s rrna gene could provide greater phylogenetic and taxonomic resolutions and advance knowledge of population dynamics within complex natural communities. we assessed the accuracy of a pacific biosciences (pacbio) single molecule, real time (smrt) sequencing based on dna polymerization, a promising 3rd generation high-throughput technique, and compared this to the 2nd generation roche 454 pyrosequencing platform. amplicons of the 16s rrna gene from a known isol ...201323999276
exploring the roles of dna methylation in the metal-reducing bacterium shewanella oneidensis mr-1.we performed whole-genome analyses of dna methylation in shewanella oneidensis mr-1 to examine its possible role in regulating gene expression and other cellular processes. single-molecule real-time (smrt) sequencing revealed extensive methylation of adenine (n6ma) throughout the genome. these methylated bases were located in five sequence motifs, including three novel targets for type i restriction/modification enzymes. the sequence motifs targeted by putative methyltranferases were determined ...201323995632
unveiling the details of electron transfer in multicenter redox proteins.metalloproteins modulate the intrinsic properties of transition metals to achieve controlled catalysis, electron transfer, or structural stabilization. those performing electron transport, redox proteins, are a diverse class of proteins with central roles in numerous metabolic and signaling pathways, including respiration and photosynthesis. many redox proteins have applications in industry, especially biotechnology, making them the focus of intense research. redox proteins may contain one or mu ...201423984680
physicochemical characterization of uridine phosphorylase from shewanella oneidensis mr-1. 201723975397
decolorization of textile azo dye and congo red by an isolated strain of the dissimilatory manganese-reducing bacterium shewanella xiamenensis bc01.shewanella xiamenensis bc01 (sxm) was isolated from sediment collected off xiamen, china and was identified based on the phylogenetic tree of 16s rrna sequences and the gyrb gene. this strain showed high activity in the decolorization of textile azo dyes, especially methyl orange, reactive red 198, and recalcitrant dye congo red, decolorizing at rates of 96.2, 93.0, and 87.5%, respectively. sxm had the best performance for the specific decolorization rate (sdr) of azo dyes compared to proteus ha ...201423974367
systematic screening of carbon-based anode materials for microbial fuel cells with shewanella oneidensis mr-1.we present a systematic screening of carbon-based anode materials for microbial fuel cells with shewanella oneidensis mr-1. under anoxic conditions nanoporous activated carbon cloth is a superior anode material in terms of current density normalized to the projected anode area and anode volume (24.0±0.3 μa cm(-2) and 482±7 μa cm(-3) at -0.2 vs. sce, respectively). the good performance can be attributed to the high specific surface area of the material, which is available for mediated electron tr ...201323954244
immobilization of whole cells by chemical vapor deposition of silica.effective entrapment of whole bacterial cells onto solid-phase materials can significantly improve bioprocessing and other biotechnology applications. cell immobilization allows integration of biocatalysts in a manner that maintains long-term cell viability and typically enhances process output. a wide variety of functionalized materials have been explored for microbial cell immobilization, and specific advantages and limitations were identified. the method described here is a simple, versatile, ...201323934813
investigation of roles of divalent cations in shewanella oneidensis pellicle formation reveals unique impacts of insoluble iron.bacteria adopt a variety of lifestyles in their natural habitats and can alternate among different lifestyles in response to environmental changes. at high cell densities, bacteria can form extracellular matrix encased cell population on submerged tangible surfaces (biofilms), or at the air-liquid interface (pellicles). compared to biofilm, pellicle lifestyle allows for better oxygen access, but is metabolically more costly to maintain. further understanding of pellicle formation and environment ...201323911985
structural insights into substrate recognition in proton-dependent oligopeptide transporters.short-chain peptides are transported across membranes through promiscuous proton-dependent oligopeptide transporters (pots)--a subfamily of the major facilitator superfamily (mfs). the human pots, pept1 and pept2, are also involved in the absorption of various drugs in the gut as well as transport to target cells. here, we present a structure of an oligomeric pot transporter from shewanella oneidensis (peptso2), which was crystallized in the inward open conformation in complex with the peptidomi ...201323867627
fate of arsenic during microbial reduction of biogenic versus abiogenic as-fe(iii)-mineral coprecipitates.fe(iii) (oxyhydr)oxide minerals exhibit a high sorption affinity for arsenic (as) and the reductive dissolution of as-bearing fe(iii) (oxyhydr)oxides is considered to be the primary mechanism for as release into groundwater. to date, research has focused on the reactivity of abiogenic fe(iii) (oxyhydr)oxides, yet in nature biogenic fe(iii) (oxyhydr)oxides, precipitated by fe(ii)-oxidizing bacteria are also present. these biominerals contain cell-derived organic matter (cdom), leading to differen ...201323806105
differential arsenic mobilization from as-bearing ferrihydrite by iron-respiring shewanella strains with different arsenic-reducing activities.arsenic immobilization and release in the environment is significantly influenced by bacterial oxidation and reduction of arsenic and arsenic-bearing minerals. in this study, we tested three iron-reducing bacteria, shewanella oneidensis mr-1, shewanella sp. hn-41, and shewanella putrefaciens 200, which have diverse arsenate-reducing activities with regard to reduction of an as-bearing ferrihydrite slurry. in the cultures of s. oneidensis mr-1 and shewanella sp. hn-41, which are not capable of re ...201323802758
promoted reduction of tellurite and formation of extracellular tellurium nanorods by concerted reaction between iron and shewanella oneidensis mr-1.the reduction of tellurite (te(iv)) by dissimilatory metal reducing bacterium, shewanella oneidensis mr-1, was promoted in the presence of fe(iii) in comparison with te(iv) bioreduction in the absence of fe(iii). electron microscopic analyses revealed that iron promoted te(iv) reduction led to form exclusively extracellular crystalline te(0) nanorods, as compared to the mostly intracellular formation of te(0) nanorods in the absence of fe(iii). the te k-edge x-ray absorption spectrometric analys ...201323802169
protein-protein interaction regulates the direction of catalysis and electron transfer in a redox enzyme complex.protein-protein interactions are well-known to regulate enzyme activity in cell signaling and metabolism. here, we show that protein-protein interactions regulate the activity of a respiratory-chain enzyme, cyma, by changing the direction or bias of catalysis. cyma, a member of the widespread napc/nirt superfamily, is a menaquinol-7 (mq-7) dehydrogenase that donates electrons to several distinct terminal reductases in the versatile respiratory network of shewanella oneidensis . we report the inc ...201323799249
pdeb, a cyclic di-gmp-specific phosphodiesterase that regulates shewanella oneidensis mr-1 motility and biofilm formation.shewanella oneidensis mr-1, a gammaproteobacterium with respiratory versatility, forms biofilms on mineral surfaces through a process controlled by the cyclic dinucleotide messenger c-di-gmp. cellular concentrations of c-di-gmp are maintained by proteins containing ggdef and eal domains, which encode diguanylate cyclases for c-di-gmp synthesis and phosphodiesterases for c-di-gmp hydrolysis, respectively. the s. oneidensis mr-1 genome encodes several ggdef and eal domain proteins (50 and 31, resp ...201323794617
oxygen consumption rates of bacteria under nutrient-limited conditions.many environments on earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. to better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. the oxygen consumption and population density of batch cultures of escherichia coli k-12, shewanella oneidensis mr-1, and marinobacter aquaeolei vt8 were tracked for up to 200 days. t ...201323770901
microbial-enzymatic-hybrid biological fuel cell with optimized growth conditions for shewanella oneidensis dsp-10.in this work we present a biological fuel cell fabricated by combining a shewanella oneidensis microbial anode and a laccase-modified air-breathing cathode. this concept is devised as an extension to traditional biochemical methods by incorporating diverse biological catalysts with the aim of powering small devices. in preparing the biological fuel cell anode, novel hierarchical-structured architectures and biofilm configurations were investigated. a method for creating an artificial biofilm bas ...201323769313
the roles of outer membrane cytochromes of shewanella and geobacter in extracellular electron transfer.as key components of the electron transfer (et) pathways used for dissimilatory reduction of solid iron [fe(iii)] (hydr)oxides, outer membrane multihaem c-type cytochromes mtrc and omca of shewanella oneidensis mr-1 and omce and omcs of geobacter sulfurreducens mediate et reactions extracellularly. both mtrc and omca are at least partially exposed to the extracellular side of the outer membrane and their translocation across the outer membrane is mediated by bacterial type ii secretion system. p ...200923765850
aerotaxis governs floating biofilm formation in shewanella oneidensis.floating biofilm, or pellicle, is a biofilm found at the air-liquid interface. here, we show that pellicle development of the aquatic bacterium shewanella oneidensis is under the control of the chemotaxis system (che3), a regulatory system known to pilot planktonic cell motion according to environmental cues. deletion of the histidine kinase chea3 or the response regulator chey3 gene led to a heterogeneous pellicle or to the absence of pellicle respectively. in addition, a non-phosphorylatable c ...201323751053
conserved inhibitory mechanism and competent atp binding mode for adenylyltransferases with fic fold.the ubiquitous fic domain is evolutionarily conserved from bacteria to human and has been shown to catalyze amp transfer onto protein side-chain hydroxyl groups. recently, it was predicted that most catalytically competent fic proteins are inhibited by the presence of an inhibitory helix αinh that is provided by a cognate anti-toxin (class i), or is part of the n- or c-terminal part of the fic protein itself (classes ii and iii). in vitro, inhibition is relieved by mutation of a conserved glutam ...201323738009
effects of the anaerobic respiration of shewanella oneidensis mr-1 on the stability of extracellular u(vi) nanofibers.uranium (vi) is considered to be one of the most widely dispersed and problematic environmental contaminants, due in large part to its high solubility and great mobility in natural aquatic systems. we previously reported that under anaerobic conditions, shewanella oneidensis mr-1 grown in medium containing uranyl acetate rapidly accumulated long, extracellular, ultrafine u(vi) nanofibers composed of polycrystalline chains of discrete meta-schoepite (uo(3)·2h2o) nanocrystallites. wild-type mr-1 f ...201323719584
the mxd operon in shewanella oneidensis mr-1 is induced in response to starvation and regulated by arcs/arca and bara/uvry.s. oneidensis mr-1 is a dissimilatory metal-reducing bacterium. under anoxic conditions s. oneidensis mr-1 attaches to and uses insoluble minerals such as fe(iii) and mn(iv) oxides as electron acceptors. in the laboratory, s. oneidensis mr-1 forms biofilms under hydrodynamic flow conditions on a borosilicate glass surface; formation of biofilms was previously found to be dependent on the mxd gene cluster (mxdabcd).201323705927
shewanella oneidensis mr-1 bacterial nanowires exhibit p-type, tunable electronic behavior.the study of electrical transport in biomolecular materials is critical to our fundamental understanding of physiology and to the development of practical bioelectronics applications. in this study, we investigated the electronic transport characteristics of shewanella oneidensis mr-1 nanowires by conducting-probe atomic force microscopy (cp-afm) and by constructing field-effect transistors (fets) based on individual s. oneidensis nanowires. here we show that s. oneidensis nanowires exhibit p-ty ...201323701405
impact of tio2 nanoparticles on growth, biofilm formation, and flavin secretion in shewanella oneidensis.understanding of nanoparticle impacts on critical bacteria functions allows us to gain a mechanistic understanding of toxicity and guides us toward design rules for creating safe nanomaterials. herein, biofilm formation, a general bacteria function, and riboflavin secretion, a species-specific function, were monitored in shewanella oneidensis, a metal reducing bacterium, following exposure to a variety of tio2 nanoparticle types (synthesized, aeroxide p25, and t-eco). transmission electron micro ...201323701037
bacterial recognition of silicon nanowire arrays.understanding how living cells interact with nanostructures is integral to a better understanding of the fundamental principles of biology and the development of next-generation biomedical/bioenergy devices. recent studies have demonstrated that mammalian cells can recognize nanoscale topographies and respond to these structures. from this perspective, there is a growing recognition that nanostructures, along with their specific physicochemical properties, can also be used to regulate the respon ...201323682751
tuning promoter strengths for improved synthesis and function of electron conduits in escherichia coli.introduction of the electron transfer complex mtrcab from shewanella oneidensis mr-1 into a heterologous host provides a modular and molecularly defined route for electrons to be transferred to an extracellular inorganic solid. however, an escherichia coli strain expressing this pathway displayed limited control of mtrcab expression and impaired cell growth. to overcome these limitations and to improve heterologous extracellular electron transfer, we used an e. coli host with a more tunable indu ...201323656438
electrochemical analysis of shewanella oneidensis engineered to bind gold electrodes.growth in three-electrode electrochemical cells allows quantitative analysis of mechanisms involved in electron flow from dissimilatory metal reducing bacteria to insoluble electron acceptors. in these systems, gold electrodes are a desirable surface to study the electrophysiology of extracellular respiration, yet previous research has shown that certain shewanella species are unable to form productive biofilms on gold electrodes. to engineer attachment of shewanella oneidensis to gold, five rep ...201223656372
impacts of nitrate and nitrite on physiology of shewanella oneidensis.shewanella oneidensis exhibits a remarkable versatility in anaerobic respiration, which largely relies on its diverse respiratory pathways. some of these are expressed in response to the existence of their corresponding electron acceptors (eas) under aerobic conditions. however, little is known about respiration and the impact of non-oxygen eas on the physiology of the microorganism when oxygen is present. here we undertook a study to elucidate the basis for nitrate and nitrite inhibition of gro ...201323626841
mislocalization of rieske protein peta predominantly accounts for the aerobic growth defect of tat mutants in shewanella oneidensis.shewanella oneidensis exhibits a remarkable versatility in respiration, which largely relies on its various respiratory pathways. most of these pathways are composed of secretory terminal reductases and multiple associated electron transport proteins that contain cofactors such as fe-s, molybdopterin, and nife. the majority of these cofactors are inserted enzymatically in the cytoplasm, and thus are substrates of the twin-arginine translocation (tat) protein export system, which transports fully ...201323593508
indirect and suboptimal control of gene expression is widespread in bacteria.gene regulation in bacteria is usually described as an adaptive response to an environmental change so that genes are expressed when they are required. we instead propose that most genes are under indirect control: their expression responds to signal(s) that are not directly related to the genes' function. indirect control should perform poorly in artificial conditions, and we show that gene regulation is often maladaptive in the laboratory. in shewanella oneidensis mr-1, 24% of genes are detrim ...201323591776
proof of principle for an engineered microbial biosensor based on shewanella oneidensis outer membrane protein complexes.shewanella oneidensis is known for its ability to respire on extracellular electron acceptors. the spectrum of these acceptors also includes anode surfaces. based on this activity, a versatile s. oneidensis based biosensor strain was constructed in which electricity production can be modulated. construction started with the identification of a usable rate-limiting step of electron transfer to an anode. thereafter, the sensor strain was genetically engineered to produce a protein complex consisti ...201323584391
rate enhancement of bacterial extracellular electron transport involves bound flavin semiquinones.extracellular redox-active compounds, flavins and other quinones, have been hypothesized to play a major role in the delivery of electrons from cellular metabolic systems to extracellular insoluble substrates by a diffusion-based shuttling two-electron-transfer mechanism. here we show that flavin molecules secreted by shewanella oneidensis mr-1 enhance the ability of its outer-membrane c-type cytochromes (om c-cyts) to transport electrons as redox cofactors, but not free-form flavins. whole-cell ...201323576738
role of electricity production in the anaerobic decolorization of dye mixture by exoelectrogenic bacterium shewanella oneidensis mr-1.this study investigated the anaerobic decolorization of the dye mixture containing methyl orange (mo) and naphthol green b (ngb) by shewanella oneidensis mr-1. s. oneidensis mr-1 showed a strong ability to decolorize the dye mixture. mo was easier to get the electrons and inhibited the reduction of ngb, despite of its lower redox potential than ngb. the mtr respiratory pathway played an important role in this process. meantime, addition of extracellular electron shuttles accelerated the decolori ...201323567679
iron and copper act synergistically to delay anaerobic growth of bacteria.transition metals are known to cause toxic effects through their interaction with oxygen, but toxicity under anoxic conditions is poorly understood. here we investigated the effects of iron (fe) and copper (cu) on the anaerobic growth and gene expression of the purple phototrophic bacterium rhodopseudomonas palustris tie-1. we found that fe(ii) and cu(ii) act synergistically to delay anaerobic growth at environmentally relevant metal concentrations. cu(i) and cu(ii) had similar effects both alon ...201323563938
phenothiazine derivative-accelerated microbial extracellular electron transfer in bioelectrochemical system.in bioelectrochemical system (bes) the extracellular electron transfer (eet) from bacteria to anode electrode is recognized as a crucial step that governs the anodic reaction efficiency. here, we report a novel approach to substantially enhance the microbial eet by immobilization of a small active phenothiazine derivative, methylene blue, on electrode surface. a comparison of the currents generated by shewanella oneidensis mr-1 and its mutants as well as the electrochemical analytical results re ...201323563590
electron acceptor dependence of electron shuttle secretion and extracellular electron transfer by shewanella oneidensis mr-1.shewanella oneidensis mr-1 is an extensively studied dissimilatory metal-reducing bacterium with a great potential for bioremediation and electricity generation. it secretes flavins as electron shuttles which play an important role in extracellular electron transfer. however, the influence of various environmental factors on the secretion of flavins is largely unknown. here, the effects of electron acceptors, including fumarate, ferrihydrite, fe(iii)-nitrilotriacetic acid (nta), nitrate and trim ...201323558182
expression of blaa underlies unexpected ampicillin-induced cell lysis of shewanella oneidensis.shewanella oneidensis is a facultative anaerobic γ-proteobacterium possessing remarkably diverse respiratory capacities for reducing various organic and inorganic substrates. as a veteran research model for investigating redox transformations of environmental contaminants the bacterium is well known to be a naturally ampicillin-resistant microorganism. however, in this study we discovered that ampicillin has a significant impact on growth of s. oneidensis. particularly, cell lysis occurred only ...201323555975
investigating the structural dependence of protein stabilization by amino acid substitution.a goal of protein engineering technology is developing methods to increase protein stability. however, rational design of stable proteins is difficult because the stabilization mechanism of proteins is not fully understood. in this study, we examined the structural dependence of protein stabilization by introducing single amino acid substitution into ribonuclease h1 from the psychotropic bacterium shewanella oneidensis mr-1 (so-rnase h1), which was our model protein. we performed saturation muta ...201323547982
posttranslational modification of flagellin flab in shewanella oneidensis.shewanella oneidensis is a highly motile organism by virtue of a polar, glycosylated flagellum composed of flagellins flaa and flab. in this study, the functional flagellin flab was isolated and analyzed with nano-liquid chromatography-mass spectrometry (ms) and tandem ms. in combination with the mutational analysis, we propose that the flab flagellin protein from s. oneidensis is modified at five serine residues with a series of novel o-linked posttranslational modifications (ptms) that differ ...201323543712
accelerated removal of sudan dye by shewanella oneidensis mr-1 in the presence of quinones and humic acids.although there have been many studies on bacterial removal of soluble azo dyes, much less information is available for biological treatment of water-insoluble azo dyes. the few bacterial species capable of removing sudan dye generally require a long time to remove low concentrations of insoluble dye particles. the present work examined the efficient removal of sudan i by shewanella oneidensis mr-1 in the presence of redox mediator. it was found that the microbially reduced anthraquinone-2,6-disu ...201323539152
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