| crp regulates d-lactate oxidation in shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is a heterotrophic facultative anaerobe that respires using various organic and inorganic compounds. this organism has served as a model to study bacterial metabolic and regulatory systems that facilitate their survival in redox-stratified environments. the expression of many anaerobic respiratory genes in mr-1, including those for the reduction of fumarate, dimethyl sulfoxide, and metal oxides, is regulated by cyclic amp receptor protein (crp). however, relatively lit ... | 2017 | 28559887 |
| bacterial physiology: hsp90 is the hot guy for shewanella oneidensis. | | 2017 | 28496161 |
| optical elemental analysis of metals using shewanella oneidensis. | a simple method for the detection of metal ions in solution is proposed, using shewanella oneidensis, which has the ability to reduce metal ions into metal nanoparticles on the cell surface. the method can be used to identify metal ions in solution using the light-scattering characteristics of the metal nanoparticles formed on the cells. | 2017 | 28496057 |
| photovoltage response of (xzn)fe2o4-bifeo3 (x=mg, mn or ni) interfaces for highly selective cr3+, cd2+, co2+ and pb2+ ions detection. | high-photostability fluorescent (xzn)fe2o4 (x=mg, mn or ni) embedded in bifeo3 spinel-perovskite nanocomposites were successfully fabricated via a novel bio-induced phase transfer method using shewanella oneidensis mr-1. these nanocomposites have the near-infrared fluorescence response (xzn or fe)-o-o-(bi) interfaces (785/832nm), and the (xzn)fe2o4/bifeo3 lattices with high/low potentials (572.15-808.77mev/206.43-548.1mev). our results suggest that heavy metal ion (cr3+, cd2+, co2+ and pb2+) d↓ ... | 2017 | 28494305 |
| hsp90 is essential under heat stress in the bacterium shewanella oneidensis. | the hsp90 chaperone is essential in eukaryotes and activates a large array of client proteins. in contrast, its role is still elusive in bacteria, and only a few hsp90 bacterial clients are known. here, we found that hsp90 is essential in the model bacterium shewanella oneidensis under heat stress. a genetic screen for hsp90 client proteins identified tils, an essential protein involved in trna maturation. overexpression of tils rescued the growth defect of the hsp90 deletion strain under heat s ... | 2017 | 28445720 |
| anaerobic respiration on self-doped conjugated polyelectrolytes: impact of chemical structure. | we probe anaerobic respiration of bacteria in the presence of conjugated polyelectrolytes (cpes). three different cpes were used to probe how structural variations impact biocurrent generation from shewanella oneidensis mr-1. for the self-doped anionic cpe only, absorption spectroscopy shows that the addition of s. oneidensis mr-1 leads to the disappearance of the polaron (radical cation) band at >900 nm and an increase in the band at 735 nm due to the neutral species, consistent with electron t ... | 2017 | 28444923 |
| electrode assisted production of chemicals using shewanella oneidensis. | | 2017 | 28425632 |
| enhancing extracellular electron transfer of shewanella oneidensis mr-1 through coupling improved flavin synthesis and metal-reducing conduit for pollutant degradation. | dissimilatory metal reducing bacteria (dmrb) are capable of extracellular electron transfer (eet) to insoluble metal oxides, which are used as external electron acceptors by dmrb for their anaerobic respiration. the eet process has important contribution to environmental remediation mineral cycling, and bioelectrochemical systems. however, the low eet efficiency remains to be one of the major bottlenecks for its practical applications for pollutant degradation. in this work, shewanella oneidensi ... | 2017 | 28414427 |
| dynamics in the dual fuel flagellar motor of shewanella oneidensis mr-1. | the stator is an eminent component of the flagellar motor and determines a number of the motor's properties, such as the rotation-energizing coupling ion (h+ or na+) or the torque that can be generated. the stator consists of several units located in the cytoplasmic membrane surrounding the flagellar drive shaft. studies on flagellar motors of several bacterial species have provided evidence that the number as well as the retention time of stators coupled to the motor is highly dynamic and depen ... | 2017 | 28389963 |
| a genome-scale model of shewanella piezotolerans simulates mechanisms of metabolic diversity and energy conservation. | shewanella piezotolerans strain wp3 belongs to the group 1 branch of the shewanella genus and is a piezotolerant and psychrotolerant species isolated from the deep sea. in this study, a genome-scale model was constructed for wp3 using a combination of genome annotation, ortholog mapping, and physiological verification. the metabolic reconstruction contained 806 genes, 653 metabolites, and 922 reactions, including central metabolic functions that represented nonhomologous replacements between the ... | 2017 | 28382331 |
| electrogenic single-species biocomposites as anodes for microbial fuel cells. | integration of electrogenic microorganisms remains a challenge in biofuel cell technology. here, synthetic biocomposites ("artificial biofilms") are proposed. bacteria (shewanella oneidensis) are embedded in a hydrogel matrix (poly(vinyl alcohol)) via wet- and electrospinning, creating fibers and nonwoven gauzes. the bacteria remain viable and metabolically active. the performance is compared to s. oneidensis suspension cultures and "natural" biofilms. while lower than with the suspension cultur ... | 2017 | 28337840 |
| growth trade-offs accompany the emergence of glycolytic metabolism in shewanella oneidensis mr-1. | bacteria increase their metabolic capacity via the acquisition of genetic material or by the mutation of genes already present in the genome. here, we explore the mechanisms and trade-offs involved when shewanella oneidensis, a bacterium that typically consumes small organic and amino acids, rapidly evolves to expand its metabolic capacity to catabolize glucose after a short period of adaptation to a glucose-rich environment. using whole-genome sequencing and genetic approaches, we discovered th ... | 2017 | 28289083 |
| enhanced photocurrent production by the synergy of hematite nanowire-arrayed photoanode and bioengineered shewanella oneidensis mr-1. | coupling the light-harvesting capabilities of semiconductors with the catalytic power of bacteria is a promising way to increase the efficiency of bioelectrochemical systems. here, we reported the enhanced photocurrents produced by the synergy of hematite nanowire-arrayed photoanode and the bio-engineered shewanella oneidensis mr-1 in a solar-assisted microbial photoelectrochemical system (solar mps) under the visible light. to increase the supply of bioelectrons, the d-lactate transporter, so15 ... | 2017 | 28285200 |
| enhanced photovoltage response of hematite-x-ferrite interfaces (x = cr, mn, co, or ni). | high-fluorescent p-x-ferrites (xfe2o4; xfo; x = fe, cr, mn, co, or ni) embedded in n-hematite (fe2o3) surfaces were successfully fabricated via a facile bio-approach using shewanella oneidensis mr-1. the results revealed that the x ions with high/low work functions modify the unpaired spin fe2+-o2- orbitals in the xfe2o4 lattices to become localized paired spin orbitals at the bottom of conduction band, separating the photovoltage response signals (73.36~455.16/-72.63~-32.43 mev). these (fe2o3)- ... | 2017 | 28235371 |
| the role of riboflavin in decolourisation of congo red and bioelectricity production using shewanella oneidensis-mr1 under mfc and non-mfc conditions. | dissimilatory metal reducing bacteria can exchange electrons extracellularly and hold great promise for their use in simultaneous wastewater treatment and electricity production. this study investigated the role of riboflavin, an electron carrier, in the decolourisation of congo red in microbial fuel cells (mfcs) using shewanella oneidensis mr-1 as a model organism. the contribution of the membrane-bound protein mtrc to the decolourisation process was also investigated. within the range of ribof ... | 2017 | 28229332 |
| loss of oxyr reduces efficacy of oxygen respiration in shewanella oneidensis. | in many bacteria, oxyr is the major regulator controlling cellular response to h2o2. a common phenotype resulting from oxyr loss is reduced growth rate, but the underlying mechanism is unknown. we demonstrated in shewanella oneidensis, an important research model for applied and environmental microbes, that the defect is primarily due to an electron shortage to major terminal oxidase cytochrome cbb3. the loss of oxyr leads to enhanced production of electron carriers that compete for electrons ag ... | 2017 | 28195212 |
| investigation concerning the formation process of gold nanoparticles by shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is a facultative anaerobic bacterium that is known to transfer electrons generated during metabolism to various metal ions and produce nanoparticles on the bacterial surface. in this study, we tracked the formation of gold nanoparticles (au nps) on the s. oneidensis cell surfaces and investigated the roles of membrane proteins and extracellular polysaccharides in this process by spectrometry, zeta potential analysis, and electron microscopy. | 2017 | 28190828 |
| nitric oxide-induced conformational changes govern h-nox and histidine kinase interaction and regulation in shewanella oneidensis. | nitric oxide (no) is implicated in biofilm regulation in several bacterial families via heme-nitric oxide/oxygen binding (h-nox) protein signaling. shewanella oneidensis h-nox (so h-nox) is associated with a histidine kinase (so hnok) encoded on the same operon, and together they form a multicomponent signaling network whereby the no-bound state of so h-nox inhibits so hnok autophosphorylation activity, affecting the phosphorylation state of three response regulators. although the conformational ... | 2017 | 28170222 |
| integrated microfluidic flow-through microbial fuel cells. | this paper reports on a miniaturized microbial fuel cell with a microfluidic flow-through configuration: a porous anolyte chamber is formed by filling a microfluidic chamber with three-dimensional graphene foam as anode, allowing nutritional medium to flow through the chamber to intimately interact with the colonized microbes on the scaffolds of the anode. no nutritional media flow over the anode. this allows sustaining high levels of nutrient utilization, minimizing consumption of nutritional s ... | 2017 | 28120875 |
| a near-infrared light responsive c-di-gmp module-based and logic gate in shewanella oneidensis. | a novel, biofilm-based and logic gate was constructed in shewanella oneidensis through a near-infrared (nir) light responsive c-di-gmp module. the logic gate was demonstrated in microbial fuel cells with isopropyl β-d-thiogalactoside (iptg) and nir light as the inputs and electrical signals as the output. | 2017 | 28098272 |
| resilience, dynamics, and interactions within a model multispecies exoelectrogenic-biofilm community. | anode-associated multispecies exoelectrogenic biofilms are essential for the function of bioelectrochemical systems (bess). the individual activities of anode-associated organisms and physiological responses resulting from coculturing are often hard to assess due to the high microbial diversity in these systems. therefore, we developed a model multispecies biofilm comprising three exoelectrogenic proteobacteria, shewanella oneidensis, geobacter sulfurreducens, and geobacter metallireducens, with ... | 2017 | 28087529 |
| quantification of free polyelectrolytes present in colloidal suspension, revealing a source of toxic responses for polyelectrolyte-wrapped gold nanoparticles. | polyelectrolyte (pe) wrapping of colloidal nanoparticles (nps) is a standard method to control np surface chemistry and charge. because excess polyelectrolytes are usually employed in the surface modification process, it is critical to evaluate different purification strategies to obtain a clean final product and thus avoid ambiguities in the source of effects on biological systems. in this work, 4 nm diameter gold nanoparticles (aunps) were wrapped with 15 kda poly(allylamine hydrochloride) (pa ... | 2017 | 28078889 |
| transcriptome and metabolome responses of shewanella oneidensis mr-1 to methyl orange under microaerophilic and aerobic conditions. | shewanella oneidensis mr-1 degrades various azo dyes under microaerophilic and anaerobic conditions, but this process is inhibited under aerobic conditions. the mechanisms underlying azo dye biodegradation and inhibition remain unknown. therefore, we investigated metabolic and transcriptional changes in strain mr-1, which was cultured under different conditions, to elucidate these mechanisms. at the transcriptional level, genes involved in certain metabolic processes, particularly the tricarboxy ... | 2017 | 28070664 |
| microbial synthesis of bimetallic pdpt nanoparticles for catalytic reduction of 4-nitrophenol. | bimetallic nanoparticles are generally believed to have improved catalytic activity and stability due to geometric and electronic changes. in this work, biogenic-pd (bio-pd), biogenic-pt (bio-pt), and biogenic-pdpt (bio-pdpt) nanoparticles were synthesized by shewanella oneidensis mr-1 in the absence or presence of quinone. compared with direct microbial reduction process, the addition of anthraquinone-2,6-disulfonate (aqds) could promote the reduction efficiency of pd(ii) or/and pt(iv) and resu ... | 2017 | 28004366 |
| effective methods for extracting extracellular polymeric substances from shewanella oneidensis mr-1. | extracellular polymeric substances (eps) play crucial roles in bio-aggregate formation and survival of bacterial cells. to develop an effective but harmless method for eps extraction from shewanella oneidensis mr-1, five extraction methods, i.e. centrifugation (control), heating (40, 45, 50, and 60 °c), and treatments with h2so4, ethylenediaminetetraacetic acid (edta) and naoh, were examined, respectively. results from scanning electron microscope and flow cytometric analyses indicate that mr-1 ... | 2016 | 27997408 |
| mechanism of fluorescence enhancement of biosynthesized xfe2o4-bifeo3 (x = cr, mn, co, or ni) membranes. | ferrites-bismuth ferrite is an intriguing option for medical diagnostic imaging device due to its magnetoelectric and enhanced near-infrared fluorescent properties. however, the embedded xfo nanoparticles are randomly located on the bfo membranes, making implementation in devices difficult. to overcome this, we present a facile bio-approach to produce xfe2o4-bifeo3 (xfo-bfo) (x = cr, mn, co, or ni) membranes using shewanella oneidensis mr-1. the perovskite bfo enhances the fluorescence intensity ... | 2016 | 27928781 |
| cation-limited kinetic model for microbial extracellular electron transport via an outer membrane cytochrome c complex. | outer-membrane c-type cytochrome (om c-cyt) complexes in several genera of iron-reducing bacteria, such as shewanella and geobacter, are capable of transporting electrons from the cell interior to extracellular solids as a terminal step of anaerobic respiration. the kinetics of this electron transport has implications for controlling the rate of microbial electron transport during bioenergy or biochemical production, iron corrosion, and natural mineral cycling. herein, we review the findings fro ... | 2016 | 27924259 |
| anaerobic reduction of 2,6-dinitrotoluene by shewanella oneidensis mr-1: roles of mtr respiratory pathway and nfnb. | dinitrotoluene (dnt) is a widely present pollutant in aquatic environments, and its biodegradation is an economically attractive way to effectively removal. in aquatic environments, the presence of electrochemically active bacteria (eab) could contribute to the anaerobic bioreduction of dnt. however, the mechanism behind such a biodegradation process at gene level remains to be further elucidated. in this work, the anaerobic reduction of 2,6-dinitrotoluene (2,6-dnt) by shewanella oneidensis mr-1 ... | 2017 | 27869299 |
| extracellular biosynthesis of copper sulfide nanoparticles by shewanella oneidensis mr-1 as a photothermal agent. | photothermal therapy (ptt) is a minimally invasive and effective cancer treatment method and has a great potential for innovating the conventional chemotherapy approaches. copper sulfide (cus) exhibits photostability, low cost, and high absorption in near infrared region, and is recognized as an ideal candidate for ptt. however, cus, as a photothermal agent, is usually synthesized with traditional chemical approaches, which require high temperature, additional stabilization and hydrophilic modif ... | 2016 | 27866620 |
| napb in excess inhibits growth of shewanella oneidensis by dissipating electrons of the quinol pool. | shewanella, a group of ubiquitous bacteria renowned for respiratory versatility, thrive in environments where various electron acceptors (eas) of different chemical and physiological characteristics coexist. despite being extensively studied, we still know surprisingly little about strategies by which multiple eas and their interaction define ecophysiology of these bacteria. previously, we showed that nitrite inhibits growth of the genus representative shewanella oneidensis on fumarate and presu ... | 2016 | 27857202 |
| bioreductive deposition of highly dispersed ag nanoparticles on carbon nanotubes with enhanced catalytic degradation for 4-nitrophenol assisted by shewanella oneidensis mr-1. | biogenetic nanomaterials research provides insights and valuable implications for the green synthesis of nanomaterials and auxiliary biodegradation behaviors. ag nanoparticles (ag nps) fabricated on multiwalled carbon nanotubes (mwnts) (ag/mwnts nanocomposites) are prepared in situ assisted by shewanella oneidensis mr-1 (s. oneidensis mr-1) that provide respiratory pathway to transmit electrons. the ag/mwnts nanocomposites are characterized by a scanning electron microscopy (sem), an energy disp ... | 2017 | 27854056 |
| rapid construction of a whole-genome transposon insertion collection for shewanella oneidensis by knockout sudoku. | whole-genome knockout collections are invaluable for connecting gene sequence to function, yet traditionally, their construction has required an extraordinary technical effort. here we report a method for the construction and purification of a curated whole-genome collection of single-gene transposon disruption mutants termed knockout sudoku. using simple combinatorial pooling, a highly oversampled collection of mutants is condensed into a next-generation sequencing library in a single day, a 30 ... | 2016 | 27830751 |
| a mechanistic study of tio2 nanoparticle toxicity on shewanella oneidensis mr-1 with uv-containing simulated solar irradiation: bacterial growth, riboflavin secretion, and gene expression. | toxicity of nanomaterials to ecological systems has recently emerged as an important field of research, and thus, many researchers are exploring the mechanisms of how nanoparticles impact organisms. herein, we probe the mechanisms of bacteria-nanoparticle interaction by investigating how tio2 nanoparticles impact a model organism, the metal-reducing bacterium shewanella oneidensis mr-1. in addition to examining the effect of tio2 exposure, the effect of synergistic simulated solar irradiation co ... | 2017 | 27823777 |
| boosting power density of microbial fuel cells with 3d nitrogen-doped graphene aerogel electrode. | a 3d nitrogen-doped graphene aerogel (n-ga) as an anode material for microbial fuel cells (mfcs) is reported. electron microscopy images reveal that the n-ga possesses hierarchical porous structure that allows efficient diffusion of both bacterial cells and electron mediators in the interior space of 3d electrode, and thus, the colonization of bacterial communities. electrochemical impedance spectroscopic measurements further show that nitrogen doping considerably reduces the charge transfer res ... | 2016 | 27818911 |
| modulation of the reactivity of multiheme cytochromes by site-directed mutagenesis: moving towards the optimization of microbial electrochemical technologies. | dissimilatory metal-reducing bacteria perform extracellular electron transfer, a metabolic trait that is at the core of a wide range of biotechnological applications. to better understand how these microorganisms transfer electrons from their metabolism to an extracellular electron acceptor, it is necessary to characterize in detail the key players in this process, the multiheme c-type cytochromes. shewanella oneidensis mr-1 is a model organism for studying extracellular electron transfer, where ... | 2017 | 27817033 |
| microbial mediated iron redox cycling in fe (hydr)oxides for nitrite removal. | nitrite, at an environmentally relevant concentration, was significantly reduced with iron (hydr)oxides mediated by shewanella oneidensis mr-1. the average nitrite removal rates of 1.28±0.08 and 0.65±0.02(mgl-1)h-1 were achieved with ferrihydrite and magnetite, respectively. the results showed that nitrite removal was able to undergo multiple redox cycles with iron (hydr)oxides mediated by shewanella oneidensis mr-1. during the bioreduction of the following cycles, biogenic fe(ii) was subsequent ... | 2017 | 27806884 |
| an itraq characterisation of the role of tolc during electron transfer from shewanella oneidensis mr-1. | anodophilic bacteria have the ability to generate electricity in microbial fuel cells (mfcs) by extracellular electron transfer to the anode. we investigated the anode-specific responses of shewanella oneidensis mr-1, an exoelectroactive gammaproteobacterium, using for the first time itraq and 2d-lc ms/ms driven membrane proteomics to compare protein abundances in s. oneidensis when generating power in mfcs, and growing in a continuous culture. the regulated dataset produced was enriched in memb ... | 2016 | 27599463 |
| deletion of degq gene enhances outer membrane vesicle production of shewanella oneidensis cells. | shewanella oneidensis is a gram-negative facultative anaerobe that can use a wide variety of terminal electron acceptors for anaerobic respiration. in this study, s. oneidensis degq gene, encoding a putative periplasmic serine protease, was cloned and expressed. the activity of purified degq was inhibited by diisopropyl fluorophosphate, a typical serine protease-specific inhibitor, indicating that degq is a serine protease. in-frame deletion and subsequent complementation of the degq were carrie ... | 2017 | 27796471 |
| improving the molecular ion signal intensity for in situ liquid sims analysis. | in situ liquid secondary ion mass spectrometry (sims) enabled by system for analysis at the liquid vacuum interface (salvi) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. however, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. in addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. these two drawbacks have been the biggest obst ... | 2016 | 27600576 |
| mutations targeting the plug-domain of the shewanella oneidensis proton-driven stator allow swimming at increased viscosity and under anaerobic conditions. | shewanella oneidensis mr-1 possesses two different stator units to drive flagellar rotation, the na+ -dependent pomab stator and the h+ -driven motab stator, the latter possibly acquired by lateral gene transfer. although either stator can independently drive swimming through liquid, motab-driven motors cannot support efficient motility in structured environments or swimming under anaerobic conditions. using δpomab cells we isolated spontaneous mutants able to move through soft agar. we show tha ... | 2016 | 27611183 |
| wiring bacterial electron flow for sensitive whole-cell amperometric detection of riboflavin. | a whole-cell bioelectrochemical biosensing system for amperometric detection of riboflavin was developed. a "bioelectrochemical wire" (bw) consisting of riboflavin and cytochrome c between shewanella oneidensis mr-1 and electrode was characterized. typically, a strong electrochemical response was observed when riboflavin (vb2) was added to reinforce this bw. impressively, the electrochemical response of riboflavin with this bw was over 200 times higher than that without bacteria. uniquely, this ... | 2016 | 27750415 |
| enrofloxacin transformation on shewanella oneidensis mr-1 reduced goethite during anaerobic-aerobic transition. | antibiotics pollution has become a critical environmental issue worldwide due to its high ecological risk. in this study, rapid degradation of enrofloxacin (enr) was observed on goethite in the presence of shewanella oneidensis mr-1 during the transition from anaerobic to aerobic conditions. the abiotic reactions also demonstrated that over 70% with initial concentration of 10 mg l-1 enr was aerobically removed within 5 min by goethite with adsorbed fe(ii), without especial irradiation and stron ... | 2016 | 27635981 |
| light-induced reduction of silver ions to silver nanoparticles in aquatic environments by microbial extracellular polymeric substances (eps). | microbial extracellular polymeric substances (eps) widely exist in natural environments and affect the migration and transformation of pollutants in aquatic environments. previous works report that eps have some reducing functional groups and can reduce heavy metals. however, because of the weak reducing capability of eps, the reduction of heavy metals by eps without cells is extremely slow, and its effect on heavy metals species is insignificant. in this work, the accelerated reduction of silve ... | 2016 | 27728818 |
| comparative proteomics implicates a role for multiple secretion systems in electrode-respiring geobacter sulfurreducens biofilms. | geobacter sulfurreducens is a dissimilatory metal-reducing bacterium capable of forming thick electron-conducting biofilms on solid electrodes. here, we employ for the first time comparative proteomics to identify key physiological changes involved in g. sulfurreducens adaptation from fumarate-respiring planktonic cells to electron-conducting biofilms. increased levels of proteins involved in outer membrane biogenesis, cell motility and secretion are expressed in biofilms. of particular importan ... | 2016 | 27718580 |
| in situ molecular imaging of the biofilm and its matrix. | molecular mapping of live biofilms at submicrometer resolution presents a grand challenge. here, we present the first chemical mapping results of biofilm extracellular polymeric substance (eps) in biofilms using correlative imaging between super resolution fluorescence microscopy and liquid time-of-flight secondary ion mass spectrometry (tof-sims). shewanella oneidensis is used as a model organism. heavy metal chromate (cr2o72-) anions consisting of chromium cr(vi) was used as a model environmen ... | 2016 | 27709903 |
| microbial synthesis of highly dispersed pdau alloy for enhanced electrocatalysis. | biosynthesis based on the reducing capacity of electrochemically active bacteria is frequently used in the reduction of metal ions into nanoparticles as an eco-friendly way to recycle metal resources. however, those bionanoparticles cannot be used directly as electrocatalysts because of the poor conductivity of cell substrates. this problem was solved by a hydrothermal reaction, which also contributes to the heteroatom doping and alloying between pd and au. with the protection of graphene, the a ... | 2016 | 27704047 |
| oxygen tension and riboflavin gradients cooperatively regulate the migration of shewanella oneidensis mr-1 revealed by a hydrogel-based microfluidic device. | shewanella oneidensis is a model bacterial strain for studies of bioelectrochemical systems (bess). it has two extracellular electron transfer pathways: (1) shuttling electrons via an excreted mediator riboflavin; and (2) direct contact between the c-type cytochromes at the cell membrane and the electrode. despite the extensive use of s. oneidensis in bess such as microbial fuel cells and biosensors, many basic microbiology questions about s. oneidensis in the context of bes remain unanswered. h ... | 2016 | 27703448 |
| photoreduction of shewanella oneidensis extracellular cytochromes by organic chromophores and dye-sensitized tio2. | the transfer of photoenergized electrons from extracellular photosensitizers across a bacterial cell envelope to drive intracellular chemical transformations represents an attractive way to harness nature's catalytic machinery for solar-assisted chemical synthesis. in shewanella oneidensis mr-1 (mr-1), trans-outer-membrane electron transfer is performed by the extracellular cytochromes mtrc and omca acting together with the outer-membrane-spanning porin⋅cytochrome complex (mtrab). here we demons ... | 2016 | 27685371 |
| a re-evaluation of electron-transfer mechanisms in microbial electrochemistry: shewanella releases iron that mediates extracellular electron transfer. | exoelectrogenic bacteria can couple their metabolism to extracellular electron acceptors, including macroscopic electrodes, and this has applications in energy production, bioremediation and biosensing. optimisation of these technologies relies on a detailed molecular understanding of extracellular electron-transfer (eet) mechanisms, and shewanella oneidensis mr-1 (mr-1) has become a model organism for such fundamental studies. here, cyclic voltammetry was used to determine the relationship betw ... | 2016 | 27668145 |
| anodic biofilms as the interphase for electroactive bacterial growth on carbon veil. | the structure and activity of electrochemically active biofilms (eabs) are usually investigated on flat electrodes. however, real world applications such as wastewater treatment and bioelectrosynthesis require tridimensional electrodes to increase surface area and facilitate eab attachment. the structure and activity of thick eabs grown on high surface area electrodes are difficult to characterize with electrochemical and microscopy methods. here, the authors adopt a stacked electrode configurat ... | 2016 | 27609094 |
| heterogeneity of the electron exchange capacity of kitchen waste compost-derived humic acids based on fluorescence components. | composting is widely used for recycling of kitchen waste to improve soil properties, which is mainly attributed to the nutrient and structural functions of compost-derived humic acids (has). however, the redox properties of compost-derived has are not fully explored. here, a unique framework is employed to investigate the electron exchange capacity (eec) of has during kitchen waste composting. most components of compost-derived has hold eec, but nearly two-thirds of them are found to be easily d ... | 2016 | 27580607 |
| evolution of cell size homeostasis and growth rate diversity during initial surface colonization of shewanella oneidensis. | cell size control and homeostasis are fundamental features of bacterial metabolism. recent work suggests that cells add a constant size between birth and division ("adder" model). however, it is not known how cell size homeostasis is influenced by the existence of heterogeneous microenvironments, such as those during biofilm formation. shewanella oneidensis mr-1 can use diverse energy sources on a range of surfaces via extracellular electron transport (eet), which can impact growth, metabolism, ... | 2016 | 27571459 |
| in-situ growth of graphene/polyaniline for synergistic improvement of extracellular electron transfer in bioelectrochemical systems. | graphene composite has been widely used in various bioelectrochemical systems (bes). however, it is suffered from tedious fabrication procedure and ambiguous mechanism for its effect on bes. here, a one-step and in-situ strategy for simultaneously graphene exfoliation and aniline polymerization was developed for fabrication of graphene/pani composite electrode (go/panios). this go/panios outperformed graphite paper (gp), gp with pani (gp/pani) and gp with electrochemical exfoliated graphene (goh ... | 2017 | 27566391 |
| simultaneous transformation of commingled trichloroethylene, tetrachloroethylene, and 1,4-dioxane by a microbially driven fenton reaction in batch liquid cultures. | improper disposal of 1,4-dioxane and the chlorinated organic solvents trichloroethylene (tce) and tetrachloroethylene (also known as perchloroethylene [pce]) has resulted in widespread contamination of soil and groundwater. in the present study, a previously designed microbially driven fenton reaction system was reconfigured to generate hydroxyl (ho˙) radicals for simultaneous transformation of source zone levels of single, binary, and ternary mixtures of tce, pce, and 1,4-dioxane. the reconfigu ... | 2016 | 27542932 |
| molecular underpinnings of nitrite effect on cyma-dependent respiration in shewanella oneidensis. | shewanella exhibit a remarkable versatility of respiration, with a diverse array of electron acceptors (eas). in environments where these bacteria thrive, multiple eas are usually present. however, we know little about strategies by which these eas and their interaction affect ecophysiology of shewanella. in this study, we demonstrate in the model strain, shewanella oneidensis mr-1, that nitrite, not through nitric oxide to which it may convert, inhibits respiration of fumarate, and probably man ... | 2016 | 27493647 |
| direct conversion of cellulose and hemicellulose to fermentable sugars by a microbially-driven fenton reaction. | the aim of this work was to develop a microbially-driven fenton reaction that fragments cellulose and hemicellulose, degrades cellodextrins and xylodextrins, and produces short-chain oligosaccharides and monomeric sugars in a single bioreactor. the lignocellulose degradation system operates at neutral ph and does not require addition of conventional lignocellulose-degrading enzymes, thus avoiding problems associated with enzyme accessibility and specificity. the ability to produce useful bioprod ... | 2016 | 27469094 |
| effect of oxygen on the per-cell extracellular electron transfer rate of shewanella oneidensis mr-1 explored in bioelectrochemical systems. | extracellular electron transfer (eet) is a mechanism that enables microbes to respire solid-phase electron acceptors. these eet reactions most often occur in the absence of oxygen, since oxygen can act as a competitive electron acceptor for many facultative microbes. however, for shewanella oneidensis mr-1, oxygen may increase biomass development, which could result in an overall increase in eet activity. here, we studied the effect of oxygen on s. oneidensis mr-1 eet rates using bioelectrochemi ... | 2017 | 27399911 |
| regulation of gene expression in shewanella oneidensis mr-1 during electron acceptor limitation and bacterial nanowire formation. | in limiting oxygen as an electron acceptor, the dissimilatory metal-reducing bacterium shewanella oneidensis mr-1 rapidly forms nanowires, extensions of its outer membrane containing the cytochromes mtrc and omca needed for extracellular electron transfer. rna sequencing (rna-seq) analysis was employed to determine differential gene expression over time from triplicate chemostat cultures that were limited for oxygen. we identified 465 genes with decreased expression and 677 genes with increased ... | 2016 | 27342561 |
| iron isotope fractionations reveal a finite bioavailable fe pool for structural fe(iii) reduction in nontronite. | we report on stable fe isotope fractionation during microbial and chemical reduction of structural fe(iii) in nontronite nau-1. (56)fe/(54)fe fractionation factors between aqueous fe(ii) and structural fe(iii) ranged from -1.2 to +0.8‰. microbial (shewanella oneidensis and geobacter sulfurreducens) and chemical (dithionite) reduction experiments revealed a two-stage process. stage 1 was characterized by rapid reduction of a finite fe(iii) pool along the edges of the clay particles, accompanied b ... | 2016 | 27291525 |
| efficient respiration on tmao requires tord and tore auxiliary proteins in shewanella oneidensis. | respiration on trimethylamine oxide (tmao) allows bacterial survival under anoxia. in shewanella oneidensis, tor is the system involved in tmao respiration and it is encoded by the torecad operon. the tora and torc genes encode tora terminal reductase and the torc c-type cytochrome, respectively. sequence analysis suggests that tord is the putative specific chaperone of tora, whereas tore is of unknown function. the purpose of this study was to understand whether tord and tore are two accessory ... | 2016 | 27288570 |
| structures of kdnb and kdna from shewanella oneidensis: key enzymes in the formation of 8-amino-3,8-dideoxy-d-manno-octulosonic acid. | 8-amino-3,8-dideoxy-d-manno-octulosonic acid (kdo8n) is a unique amino sugar that has thus far only been observed on the lipopolysaccharides of marine bacteria belonging to the genus shewanella. although its biological function is still unclear, it is thought that the sugar is important for the integrity of the bacterial cell outer membrane. a three-gene cluster required for the biosynthesis of kdo8n was first identified in shewanella oneidensis. here we describe the three-dimensional structures ... | 2016 | 27275764 |
| bacteria-affinity 3d macroporous graphene/mwcnts/fe3o4 foams for high-performance microbial fuel cells. | promoting the performance of microbial fuel cells (mfcs) relies heavily on the structure design and composition tailoring of electrode materials. in this work, three-dimensional (3d) macroporous graphene foams incorporated with intercalated spacer of multiwalled carbon nanotubes (mwcnts) and bacterial anchor of fe3o4 nanospheres (named as g/mwcnts/fe3o4 foams) were first synthesized and used as anodes for shewanella-inoculated microbial fuel cells (mfcs). thanks to the macroporous structure of 3 ... | 2016 | 27266894 |
| bound flavin-cytochrome model of extracellular electron transfer in shewanella oneidensis: analysis by free energy molecular dynamics simulations. | flavins are known to enhance extracellular electron transfer (eet) in shewanella oneidensis mr-1 bacteria, which reduce electron acceptors through outer-membrane (om) cytochromes c. free-shuttle and bound-redox cofactor mechanisms were proposed to explain this enhancement, but recent electrochemical reports favor a flavin-bound model, proposing two one-electron reductions of flavin, namely, oxidized (ox) to semiquinone (sq) and semiquinone to hydroquinone (hq), at anodic and cathodic conditions, ... | 2016 | 27266856 |
| modeling of sustainable base production by microbial electrolysis cell. | a predictive model for the microbial/electrochemical base formation from wastewater was established and compared to experimental conditions within a microbial electrolysis cell. a na2 so4 /k2 so4 anolyte showed that model prediction matched experimental results. using shewanella oneidensis mr-1, a strong base (ph≈13) was generated using applied voltages between 0.3 and 1.1 v. due to the use of bicarbonate, the ph value in the anolyte remained unchanged, which is required to maintain microbial ac ... | 2016 | 27265318 |
| contribution of direct electron transfer mechanisms to overall electron transfer in microbial fuel cells utilising shewanella oneidensis as biocatalyst. | to investigate the contribution of direct electron transfer mechanisms to electricity production in microbial fuel cells by physically retaining shewanella oneidensis cells close to or away from the anode electrode. | 2016 | 27193895 |
| a decahaem cytochrome as an electron conduit in protein-enzyme redox processes. | the decahaem cytochrome mtrc from shewanella oneidensis mr-1 was employed as a protein electron conduit between a porous indium tin oxide electrode and redox enzymes. using a hydrogenase and a fumarate reductase, mtrc was shown as a suitable and efficient diode to shuttle electrons to and from the electrode with the mtrc redox activity regulating the direction of the enzymatic reactions. | 2016 | 27193068 |
| k-shell analysis reveals distinct functional parts in an electron transfer network and its implications for extracellular electron transfer. | shewanella oneidensis mr-1 is capable of extracellular electron transfer (eet) and hence has attracted considerable attention. the eet pathways mainly consist of c-type cytochromes, along with some other proteins involved in electron transfer processes. by whole genome study and protein interactions inquisition, we constructed a large-scale electron transfer network containing 2276 interactions among 454 electron transfer related proteins in s. oneidensis mr-1. using the k-shell decomposition me ... | 2016 | 27148219 |
| evolved plasmid-host interactions reduce plasmid interference cost. | antibiotic selection drives adaptation of antibiotic resistance plasmids to new bacterial hosts, but the molecular mechanisms are still poorly understood. we previously showed that a broad-host-range plasmid was poorly maintained in shewanella oneidensis, but rapidly adapted through mutations in the replication initiation gene trfa1. here we examined if these mutations reduced the fitness cost of trfa1, and whether this was due to changes in interaction with the host's dna helicase dnab. the str ... | 2016 | 27121483 |
| shewanella oneidensis mr-1-induced fe(iii) reduction facilitates roxarsone transformation. | although microbial activity and associated iron (oxy)hydroxides are known in general to affect the environmental dynamics of 4-hydroxy-3-nitrobenzenearsonic acid (roxarsone), the mechanistic understanding of the underlying biophysico-chemical processes remains unclear due to limited experimental information. we studied how shewanella oneidensis mr-1 -a widely distributed metal-reducing bacterium, in the presence of dissolved fe(iii), affects roxarsone transformations and biogeochemical cycling i ... | 2016 | 27100323 |
| trace heavy metal ions promoted extracellular electron transfer and power generation by shewanella in microbial fuel cells. | although microbial fuel cells (mfcs) is considered as one of the most promising technology for renewable energy harvesting, low power output still accounts one of the bottlenecks and limits its further development. in this work, it is found that cu(2+) (0.1μgl(-1)-0.1mgl(-1)) or cd(2+) (0.1μgl(-1)-1mgl(-1)) significantly improve the electricity generation in mfcs. the maximum power output achieved with trace level of cu(2+) (∼6nm) or cd(2+) (∼5nm) is 1.3 times and 1.6 times higher than that of t ... | 2016 | 27038263 |
| adhesion of shewanella oneidensis mr-1 to goethite: a two-dimensional correlation spectroscopic study. | bacterial adhesion to mineral surfaces is an important but underappreciated process. to decipher the molecular level process and mechanism, the adhesion of shewanella oneidensis mr-1 cells to goethite was investigated using flow-cell attenuated total reflectance (atr) fourier transform infrared (ftir) spectroscopy coupled with two-dimensional correlation spectroscopy (2d-cos) analysis. the ftir results indicate that bacterial phosphate-moieties play an important role in the formation of mono- an ... | 2016 | 27029565 |
| real-time manganese phase dynamics during biological and abiotic manganese oxide reduction. | manganese oxides are often highly reactive and easily reduced, both abiotically, by a variety of inorganic chemical species, and biologically during anaerobic respiration by microbes. to evaluate the reaction mechanisms of these different reduction routes and their potential lasting products, we measured the sequence progression of microbial manganese(iv) oxide reduction mediated by chemical species (sulfide and ferrous iron) and the common metal-reducing microbe shewanella oneidensis mr-1 under ... | 2016 | 27018915 |
| concerted action of two subunits of the functional dimer of shewanella oneidensis mr-1 uridine phosphorylase derived from a comparison of the c212s mutant and the wild-type enzyme. | uridine phosphorylase (up; ec 2.4.2.3), a key enzyme in the pyrimidine-salvage pathway, catalyzes the reversible phosphorolysis of uridine to uracil and ribose 1-phosphate. the structure of the c212s mutant of uridine phosphorylase from the facultatively aerobic gram-negative γ-proteobacterium shewanella oneidensis mr-1 (soup) was determined at 1.68 å resolution. a comparison of the structures of the mutant and the wild-type enzyme showed that one dimer in the mutant hexamer differs from all oth ... | 2016 | 26894668 |
| formate metabolism in shewanella oneidensis generates proton motive force and prevents growth without an electron acceptor. | shewanella oneidensis strain mr-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. conversely, the electron donors utilized by s. oneidensis are more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. lactate, pyruvate, and hydrogen metabolisms ins. oneidensis have been described previously, but little is known about the role of formate oxidation i ... | 2016 | 26883823 |
| ¹³c pathway analysis for the role of formate in electricity generation by shewanella oneidensis mr-1 using lactate in microbial fuel cells. | microbial fuel cell (mfc) is a promising technology for direct electricity generation from organics by microorganisms. the type of electron donors fed into mfcs affects the electrical performance, and mechanistic understanding of such effects is important to optimize the mfc performance. in this study, we used a model organism in mfcs, shewanella oneidensis mr-1, and (13)c pathway analysis to investigate the role of formate in electricity generation and the related microbial metabolism. our resu ... | 2016 | 26868848 |
| in situ monitoring of shewanella oneidensis mr-1 biofilm growth on gold electrodes by using a pt microelectrode. | much attention has been focused on electrochemically active bacteria (eab) in the application of bioelectrochemical systems (bess). studying the eab biofilm growth mechanism as well as electron transfer mechanism provides a route to upgrade bes performance. but an effective bacterial growth monitoring method on the biofilm scale is still absent in this field. in this work, electrode-attached bacterial biofilms formed by shewanella oneidensis mr-1 were dynamically monitored through a microelectro ... | 2016 | 26850925 |
| biochar-facilitated microbial reduction of hematite. | as an important component of soil organic matter (som), the transformation of pyrogenic carbon plays a critical role in the biogeochemical cycles of carbon and other redox-active elements such as iron (fe). herein, we studied the influences of wheat straw-derived biochars on the microbial reduction of 100 mm of hematite by the dissimilatory metal reducing bacteria shewanella oneidensis mr-1 under anoxic conditions. the long-term microbial reduction extent and initial reduction rate of hematite w ... | 2016 | 26836650 |
| use of an electrochemical split cell technique to evaluate the influence of shewanella oneidensis activities on corrosion of carbon steel. | microbially induced corrosion (mic) is a complex problem that affects various industries. several techniques have been developed to monitor corrosion and elucidate corrosion mechanisms, including microbiological processes that induce metal deterioration. we used zero resistance ammetry (zra) in a split chamber configuration to evaluate the effects of the facultatively anaerobic fe(iii) reducing bacterium shewanella oneidensis mr-1 on the corrosion of uns g10180 carbon steel. we show that activit ... | 2016 | 26824529 |
| expression of terminal oxidases under nutrient-starved conditions in shewanella oneidensis: detection of the a-type cytochrome c oxidase. | shewanella species are facultative anaerobic bacteria that colonize redox-stratified habitats where o2 and nutrient concentrations fluctuate. the model species shewanella oneidensis mr-1 possesses genes coding for three terminal oxidases that can perform o2 respiration: a bd-type quinol oxidase and cytochrome c oxidases of the cbb3-type and the a-type. whereas the bd- and cbb3-type oxidases are routinely detected, evidence for the expression of the a-type enzyme has so far been lacking. here, we ... | 2016 | 26815910 |
| deciphering the aggregation mechanism of bacteria (shewanella oneidensis mr1) in the presence of polyethyleneimine: effects of the exopolymeric superstructure and polymer molecular weight. | aggregation tests between bacteria and polyethyleneimine (pei) of low (600g/mol) and high (750,000g/mol) molecular weight were performed in order to address the physico-chemical mechanisms underlying the interactions between cationic polymer and bacterial membranes. the selected strain, schewanella oneidensis mr-1, produces a lipopolysaccharide (lps) of various lengths depending on the growth conditions. optical density, bioaggregate size, electrophoretic mobility measurements, tem and afm obser ... | 2016 | 26774052 |
| designed diblock hairpin probes for the nonenzymatic and label-free detection of nucleic acid. | the detection of nucleic acid sequences is of great importance in a variety of fields. an ultrasensitive dna sensing platform is constructed using elaborately designed diblock hairpin probes (dhps) that are composed of hairpin and poly-adenine blocks. the introduction of an initiator dna target triggers the catalytic assembly of probes dhp1, dhp2 and dhp3 to fabricate numerous poly-adenine-tailed branched dna junctions, which significantly amplify the signal of the target-dna-recognizing event w ... | 2016 | 26765529 |
| conjugated gold nanoparticles as a tool for probing the bacterial cell envelope: the case of shewanella oneidensis mr-1. | the bacterial cell envelope forms the interface between the interior of the cell and the outer world and is, thus, the means of communication with the environment. in particular, the outer cell surface mediates the adhesion of bacteria to the surface, the first step in biofilm formation. while a number of ligand-based interactions are known for the attachment process in commensal organisms and, as a result, opportunistic pathogens, the process of nonspecific attachment is thought to be mediated ... | 2016 | 26746161 |
| water dynamics in shewanella oneidensis at ambient and high pressure using quasi-elastic neutron scattering. | quasielastic neutron scattering (qens) is an ideal technique for studying water transport and relaxation dynamics at pico- to nanosecond timescales and at length scales relevant to cellular dimensions. studies of high pressure dynamic effects in live organisms are needed to understand earth's deep biosphere and biotechnology applications. here we applied qens to study water transport in shewanella oneidensis at ambient (0.1 mpa) and high (200 mpa) pressure using h/d isotopic contrast experiments ... | 2016 | 26738409 |
| three-dimensional graphene/pt nanoparticle composites as freestanding anode for enhancing performance of microbial fuel cells. | microbial fuel cells (mfcs) are able to directly convert about 50 to 90% of energy from oxidation of organic matters in waste to electricity and have great potential application in broad fields such as wastewater treatment. unfortunately, the power density of the mfcs at present is significantly lower than the theoretical value because of technical limitations including low bacteria loading capacity and difficult electron transfer between the bacteria and the electrode. we reported a three-dimen ... | 2015 | 26702430 |
| genomic barcode-based analysis of exoelectrogens in wastewater biofilms grown on anode surfaces. | the most energy-demanding step of wastewater treatment is the aeration-dependent elimination of organic carbon. microbial fuel cells (mfcs) offer an alternative strategy in which carbon elimination is conducted by anaerobic microorganisms that transport respiratory electrons originating from carbon oxidation to an anode. hence, chemical energy is directly transformed into electrical energy. in this study, the use and stability of barcodecontaining exoelectrogenic model biofilms under non-axenic ... | 2016 | 26699756 |
| biotransformation and biomethylation of arsenic by shewanella oneidensis mr-1. | the resistance of shewanella oneidensis mr-1 to toxic arsenic was investigated by measuring the growth of the bacteria in the presence of as(iii) and as(v) in different growth media. the bacteria were shown to biotransform arsenic through the partial methylation of inorganic arsenic into methylated metabolites. this biotransformation of inorganic arsenic by s. oneidensis mr-1 was affected by the methyl donor, the composition of the medium, and the presence of fe(iii). the relative content of met ... | 2016 | 26692509 |
| influence of riboflavin on the reduction of radionuclides by shewanella oneidenis mr-1. | uranium (as uo2(2+)), technetium (as tco4(-)) and neptunium (as npo2(+)) are highly mobile radionuclides that can be reduced enzymatically by a range of anaerobic and facultatively anaerobic microorganisms, including shewanella oneidensis mr-1, to poorly soluble species. the redox chemistry of pu is more complicated, but the dominant oxidation state in most environments is highly insoluble pu(iv), which can be reduced to pu(iii) which has a potentially increased solubility which could enhance mi ... | 2016 | 26632613 |
| iron reduction in the damo/shewanella oneidensis mr-1 coculture system and the fate of fe(ii). | dissimilatory iron reduction and anaerobic methane oxidation processes play important roles in the global iron and carbon cycle, respectively. this study explored the ferrihydrite reduction process with methane as a carbon source in a coculture system of denitrifying anaerobic methane oxidation (damo) microbes enriched in laboratory and shewanella oneidensis mr-1, and then characterized the reduced products. ferrihydrite reduction was also studied in the damo and shewanella systems alone. the fe ... | 2016 | 26599434 |
| fate of fe and cd upon microbial reduction of cd-loaded polyferric flocs by shewanella oneidensis mr-1. | polyferric sulphate has been widely used for emergent control on incidental release of heavy metals such as cd to surface water, causing precipitation of cd-loaded polyferric flocs to the sediment. to date, little is known about whether the dissolution of the flocs in the presence of dissimilatory iron reducing bacteria (dirb) can occur and how the dissolution influences the fate of fe and cd in the sediment. here, we demonstrated that shewanella oneidensis mr-1, as representative dirb, has the ... | 2016 | 26583288 |
| functionally distinct bacterial cytochrome c peroxidases proceed through a common (electro)catalytic intermediate. | the diheme cytochrome c peroxidase from shewanella oneidensis (so ccp) requires a single electron reduction to convert the oxidized, as-isolated enzyme to an active conformation. we employ protein film voltammetry to investigate the mechanism of hydrogen peroxide turnover by so ccp. when the enzyme is poised in the active state by incubation with sodium l-ascorbate, the graphite electrode specifically captures a highly active state that turns over peroxide in a high potential regime. this is the ... | 2016 | 26575087 |
| electroanalysis of shewanella oneidensis mr-1. | electrochemical parameters of bacterial cells shewanella oneidensis mr-1 were investigated. for registration of the direct electron transfer between s. oneidensis mr-1 and electrode, bacterial cells were pretreated with didodecyldimethylammonium bromide (ddab), a synthetic membrane-like substance of polycationic nature that exhibits membrane-loosening properties. such pretreatment of s. oneidensis mr-1 allowed increasing the efficiency of extracellular electron transfer by the proteobacterium du ... | 2015 | 26518560 |
| [effects of dissimilatory reduction of goethite on mercury methylation by shewanella oneidensis mr-1]. | the effects of the biological dissolution and reduction of goethite on mercury methylation by shewanella oneidensis mr-1 were studied under laboratory conditions. the results showed that s. oneidensis mr-1 could dissolve goethite, and subsequently dissolved fe3+ which was reduced to fe2+. s. oneidensis mr-1 was also a kind of mercury methylation bacterial, which had a potential to transform inorganic mercury to methylmercury. the biological dissolution and reduction of goethite declined with the ... | 2015 | 26387333 |
| positive regulation of the shewanella oneidensis omps38, a major porin facilitating anaerobic respiration, by crp and fur. | major porins are among the most abundant proteins embedded in the outer membrane (om) of gram-negative bacteria, playing crucial roles in maintenance of membrane structural integrity and om permeability. although many om proteins (especially c-type cytochromes) in shewanella oneidensis, a research model for respiratory versatility, have been extensively studied, physiological significance of major porins remains largely unexplored. in this study, we show that omps38 and ompa are two major porins ... | 2015 | 26381456 |
| carbon nanotube composite electrode coated with polypyrrole for microbial fuel cell application. | microbial fuel cells (mfcs) are bio-electrochemical system that can convert biomass spontaneously into electricity through the metabolic activity of microorganisms. we constructed mfcs of polypyrrole (ppy) coated carbon nanotube (cnt) composite as an electrode material and shewanella oneidensis as the biocatalyst to increase power density. the ppy-coated cnt were synthesized by the in-situ chemical polymerization of pyrrole on cnt, and the electrochemical properties and performance of the modifi ... | 2015 | 26328387 |
| a matter of timing: contrasting effects of hydrogen sulfide on oxidative stress response in shewanella oneidensis. | hydrogen sulfide (h2s), well known for its toxic properties, has recently become a research focus in bacteria, in part because it has been found to prevent oxidative stress caused by treatment with some antibiotics. h2s has the ability to scavenge reactive oxygen species (ros), thus preventing oxidative stress, but it is also toxic, leading to conflicting reports of its effects in different organisms. here, with shewanella oneidensis as a model, we report that the effects of h2s on the response ... | 2015 | 26324455 |
| microbial synthesis of pd/fe3o4, au/fe3o4 and pdau/fe3o4 nanocomposites for catalytic reduction of nitroaromatic compounds. | magnetically recoverable noble metal nanoparticles are promising catalysts for chemical reactions. however, the chemical synthesis of these nanocatalysts generally causes environmental concern due to usage of toxic chemicals under extreme conditions. here, pd/fe3o4, au/fe3o4 and pdau/fe3o4 nanocomposites are biosynthesized under ambient and physiological conditions by shewanella oneidensis mr-1. microbial cells firstly transform akaganeite into magnetite, which then serves as support for the fur ... | 2015 | 26310728 |
| isobutanol production from an engineered shewanella oneidensis mr-1. | shewanella oneidensis mr-1 is one of the most well-known metal-reducing bacteria and it has been extensively studied for microbial fuel cell and bioremediation aspects. in this study, we have examined s. oneidensis mr-1 as an isobutanol-producing host by assessing three key factors such as isobutanol synthetic genes, carbon sources, and electron supply systems. heterologous ehrlich pathway genes, kivd encoding ketoisovalerate decarboxylase and adh encoding alcohol dehydrogenase, were constructed ... | 2015 | 26280214 |
| lipopolysaccharide density and structure govern the extent and distance of nanoparticle interaction with actual and model bacterial outer membranes. | design of nanomedicines and nanoparticle-based antimicrobial and antifouling formulations and assessment of the potential implications of nanoparticle release into the environment requires understanding nanoparticle interaction with bacterial surfaces. here we demonstrate the electrostatically driven association of functionalized nanoparticles with lipopolysaccharides of gram-negative bacterial outer membranes and find that lipopolysaccharide structure influences the extent and location of bindi ... | 2015 | 26207769 |
| a decaheme cytochrome as a molecular electron conduit in dye-sensitized photoanodes. | in nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. here, it is aimed to mimic this by coupling dye-sensitized tio2 nanocrystals to a decaheme protein, mtrc from shewanella oneidensis mr-1, where the 10 hemes of mtrc form a ≈7-nm-long molecular wire between the tio2 and the underlying electrode. the system is assembled by forming a densely packed mtrc film on an ultra-flat gold electrode, followed by the adsorption of approximately 7 ... | 2015 | 26180522 |
| monitoring electron and proton diffusion flux through three-dimensional, paper-based, variable biofilm and liquid media layers. | the goal of this work is to pursue analytical approaches that elucidate electron and proton diffusion inside the shewanella oneidensis biofilm and bulk liquid, which will inevitably promote the translation of microbial fuel cell (mfc) technology for renewable, "green energy" solutions that are in demand to sustain the world's ever-increasing energy demands and to mitigate the depletion of current resources. this study provides a novel strategy for monitoring electron/proton fluxes in 3-d multi-l ... | 2015 | 26179156 |