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Immobilization of organophosphohydrolase OpdA from Agrobacterium radiobacter by overproduction at the surface of polyester inclusions inside engineered Escherichia coli.Organophosphorus pesticides (OP) are highly toxic and are widely used as insecticides. Bacterial organophosphohydrolases which hydrolyse a variety of OPs have been considered for the clean-up of polluted environments. This study describes the engineering of Escherichia coli towards the overproduction of the organophosphohydrolase (OpdA) from A. radiobacter at the surface of polyester inclusions. The OpdA was N-terminally fused via a designed linker region to the C-terminus of polyester inclusion ...201122170266
identification and clarification of the role of key active site residues in bacterial glutathione s-transferase zeta/maleylpyruvate isomerase.the maleylpyruvate isomerase nagl from ralstonia sp. strain u2, which has been structurally characterized previously, catalyzes the isomerization of maleylpyruvate to fumarylpyruvate. it belongs to the class zeta glutathione s-transferases (gstzs), part of the cytosolic gst family (cgsts). in this study, site-directed mutagenesis was conducted to probe the functions of 13 putative active site residues. steady-state kinetic information for mutants in the reduced glutathione (gsh) binding site, su ...201121672526
production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by ralstonia eutropha in high cell density palm oil fermentations.improved production costs will accelerate commercialization of polyhydroxyalkanoate (pha) polymer and pha-based products. plant oils are considered favorable feedstocks, due to their high carbon content and relatively low price compared to sugars and other refined carbon feedstocks. different pha production strategies were compared using a recombinant strain of ralstonia eutropha that produces high amounts of p(hb-co-hhx) when grown on plant oils. this r. eutropha strain was grown to high cell d ...201121809332
isolation and characterization of a novel virulent podovirus which infects burkholderia pseudomallei.abstract: burkholderia pseudomallei is a saprophytic soil bacterium and the etiological agent that causes melioidosis. it is naturally resistant to many antibiotics and therefore is difficult to treat. bacteriophages may provide an alternative source of treatment. we have isolated and characterised the bacteriophage phi bp-amp1. the phage is a member of the podoviridae family and has a genome size of ~ 45 kb. molecular data based on the gene which encodes for the phage tail tubular protein sugge ...201121791081
prediction of protein-protein interactions between ralstonia solanacearum and arabidopsis thaliana.ralstonia solanacearum is a devastating bacterial pathogen that has an unusually wide host range. r. solanacearum, together with arabidopsis thaliana, has become a model system for studying the molecular basis of plant-pathogen interactions. protein-protein interactions (ppis) play a critical role in the infection process, and some ppis can initiate a plant defense response. however, experimental investigations have rarely addressed such ppis. using two computational methods, the interolog and t ...201121786137
Isolation and characterization of a soluble and thermostable phosphite dehydrogenase from Ralstonia sp. strain 4506.Phosphite dehydrogenase (PtxD), which catalyzes the nearly irreversible oxidation of phosphite to phosphate with the concomitant reduction of NAD(+) to NADH, has great potential for NADH regeneration in industrial biocatalysts. Here, we isolated a soil bacterium, Ralstonia sp. strain 4506, that grew at 45°C on a minimal medium containing phosphite as the sole source of phosphorus. A recombinant PtxD of Ralstonia sp. (PtxD(R4506)) appeared in the soluble fraction in Escherichia coli. The purified ...201122197497
diversity analysis of diazotrophic bacteria associated with the roots of tea (camellia sinensis (l.) o. kuntze).the diversity elucidation by amplified ribosomal dna restriction analysis and 16s rdna sequencing of 96 associative diazotrophs, isolated from the feeder roots of tea on enriched nitrogen-free semisolid media, revealed the predominance of gram-positive over gram-negative bacteria within the kangra valley in himachal pradesh, india. the gram-positive bacteria observed belong to two taxonomic groupings; firmicutes, including the genera bacillus and paenibacillus; and actinobacteria, represented by ...201121715960
surveillance of single-cell behavior in different subpopulations of ralstonia pickettii ar1 during growth and polyhydroxybutyrate production phases by flow cytometry.most bacterial strains accumulate intracellular polyhydroxybutyrate (phb) granules as an energy reservoir, in response to fluctuations in their microenvironment. flow cytometry was applied for the analysis of single cells of ralstonia pickettii ar1 in response to changes in the culture conditions. two parameters, the phb production-related fl2 and side scatter (ssc) parameters, were used to monitor, distinguish and characterize different subpopulations in the growth and phb production phases. a ...201121780145
lobar pneumonia caused by ralstonia pickettii in a sixty-five-year-old han chinese man: a case report.abstract:201121843320
insights into the structure of the active site of the o(2)-tolerant membrane bound [nife] hydrogenase of r. eutropha h16 by molecular modelling.structural models for the ni-b state of the wild-type and c81s protein variant of the membrane-bound [nife] hydrogenase from ralstonia eutropha h16 were derived by applying the homology model technique combined with molecular simulations and a hybrid quantum mechanical/molecular mechanical approach. the active site structure was assessed by comparing calculated and experimental ir spectra, confirming the view that the active site structure is very similar to those of anaerobic standard hydrogena ...201121833416
the yopj superfamily in plant-associated bacteria.bacterial pathogens employ the type iii secretion system to secrete and translocate effector proteins into their hosts. the primary function of these effector proteins is believed to be the suppression of host defence responses or innate immunity. however, some effector proteins may be recognized by the host and consequently trigger a targeted immune response. the yopj/hopz/avrrxv family of bacterial effector proteins is a widely distributed and evolutionarily diverse family, found in both anima ...201121726386
complete genome sequence of the plant pathogen ralstonia solanacearum strain po82.ralstonia solanacearum strain po82, a phylotype iib/sequevar 4 strain, was found to be pathogenic to both solanaceous plants and banana. here, we report the complete genome sequence of po82 and its comparison with seven published r. solanacearum genomes.201121685279
priming by rhizobacterium protects tomato plants from biotrophic and necrotrophic pathogen infections through multiple defense mechanisms.a selected strain of rhizobacterium, pseudomonas putida strain lsw17s (lsw17s), protects tomato plants (lycopersicon esculentum l. cv. seokwang) from bacterial speck by biotrophic pseudomonas syringae pv. tomato strain dc3000 (dc3000) and bacterial wilt by necrotrophic ralstonia solanacearum kacc 10703 (rs10703). to investigate defense mechanisms induced by lsw17s in tomato plants, transcription patterns of pathogenesis-related (pr) genes and h(2)o(2) production were analyzed in plants treated w ...201121710203
biosynthesis of polyhydroxyalkanoates containing 2-hydroxybutyrate from unrelated carbon source by metabolically engineered escherichia coli.we have previously reported in vivo biosynthesis of polylactic acid (pla) and poly(3-hydroxybutyrate-co-lactate) [p(3hb-co-la)] employing metabolically engineered escherichia coli strains by the introduction of evolved clostridium propionicum propionyl-coa transferase (pct( cp )) and pseudomonas sp. mbel 6-19 polyhydroxyalkanoate (pha) synthase 1 (phac1( ps6-19)). using this in vivo pla biosynthesis system, we presently report the biosynthesis of phas containing 2-hydroxybutyrate (2hb) monomer b ...201121842437
the fucose-binding lectin from opportunistic pathogen burkholderia ambifaria binds to both plant and human oligosaccharidic epitopes.burkholderia ambifaria is generally associated with the rhizosphere of plants where it has biocontrol effects on other microorganisms. it is also a member of the burkhoderia cepacia complex, a group of closely related bacteria that causes lung infections in immunocompromised patients, as well as patients with granulomatous disease or cystic fibrosis. our previous work indicated that fucose on human epithelia is a frequent target for lectins and adhesins of lung pathogens (sulak et al., plos path ...201122170069
characterization and quantification of the nickel resistant microbial community in activated sludge using 16s rdna and nickel resistance genes.the effect of nickel on the microbial community in the activated sludge of a sequencing batch reactor (sbr) reactor was investigated by continuously dosing nickel from 60 to 240 mg ni(ii) l(-1). the diversity of the microbial community was investigated by polymerase chain reaction (pcr) and denaturing gradient gel electrophoresis of the variable v3 region of the bacterial 16s rdna. the experimental results showed that the community structure changed significantly after dosing with nickel with a ...201121877534
Comparative and functional genomics of Rhodococcus opacus PD630 for biofuels development.The Actinomycetales bacteria Rhodococcus opacus PD630 and Rhodococcus jostii RHA1 bioconvert a diverse range of organic substrates through lipid biosynthesis into large quantities of energy-rich triacylglycerols (TAGs). To describe the genetic basis of the Rhodococcus oleaginous metabolism, we sequenced and performed comparative analysis of the 9.27 Mb R. opacus PD630 genome. Metabolic-reconstruction assigned 2017 enzymatic reactions to the 8632 R. opacus PD630 genes we identified. Of these, 261 ...201121931557
Functional diversification of the GALA type III effector family contributes to Ralstonia solanacearum adaptation on different plant hosts.Type III effectors from phytopathogenic bacteria exhibit a high degree of functional redundancy, hampering the evaluation of their precise contribution to pathogenicity. This is illustrated by the GALA type III effectors from Ralstonia solanacearum, which have been shown to be collectively, but not individually, required for disease on Arabidopsis thaliana and tomato. We investigated evolution, redundancy and diversification of this family in order to understand the individual contribution of th ...201121902695
lc-ms/ms quantification of short-chain acyl-coa's in escherichia coli demonstrates versatile propionyl-coa synthetase substrate specificity.aims:  this paper utilized quantitative lc-ms/ms to profile the short-chain acyl-coa levels of several strains of escherichia coli engineered for heterologous polyketide production. to further compare and potentially expand the levels of available acyl-coa molecules, a propionyl-coa synthetase gene from ralstonia solanacearum (prpe-rs) was synthesized and expressed in the engineered strain bap1. methods and results:  upon feeding propionate, the engineered e. coli strains had increased the level ...201122118660
only one of the five ralstonia solanacearum long-chain 3-ketoacyl-acp synthase homologues functions in fatty acid synthesis.ralstonia solanacearum, a major phytopathogenic bacterium, causes a bacterial wilt disease in diverse plants. although fatty acid analyses of r. solanacearum showed that they contain primarily palmitic (c16:0), palmitoleic (c16: 1) and cis-vaccenic (c18: 1) acid, little is known of r. solanacearum fatty acid synthesis. the r. solanacearum gmi1000 genome is unusual in that it contains four genes (fabf1, fabf2, fabf3 and fabf4) annotated as encoding 3-ketoacyl-acyl carrier protein synthase ii homo ...201122194290
The crystal structure of an oxygen-tolerant hydrogenase uncovers a novel iron-sulphur centre.Hydrogenases are abundant enzymes that catalyse the reversible interconversion of H(2) into protons and electrons at high rates. Those hydrogenases maintaining their activity in the presence of O(2) are considered to be central to H(2)-based technologies, such as enzymatic fuel cells and for light-driven H(2) production. Despite comprehensive genetic, biochemical, electrochemical and spectroscopic investigations, the molecular background allowing a structural interpretation of how the catalytic ...201122002606
ralstonia mannitolilytica and copd: a case report. 201122130767
Cupriavidus and Burkholderia species associated with agricultural plants that grow in alkaline soils.The presence of Burkholderia, Cupriavidus, and Ralstonia species in northeastern Mexico was investigated. An analysis of the root surrounding soil from different agricultural plants led to the isolation of Burkholderia and Cupriavidus species but no Ralstonia strains. Most Cupriavidus species were unknown and grouped into two clusters according to ARDRA profiles. The 16S rRNA sequence analysis showed that the Cupriavidus isolates were highly related among them and with different Cupriavidus spec ...201122203548
detection and functional characterization of a large genomic deletion resulting in decreased pathogenicity in ralstonia solanacearum race 3 biovar 2 strains.bacterial wilt (brown rot) disease of potato caused by ralstonia solanacearum is one of the most important bacterial diseases and a major constraint on potato production worldwide. through a comparative genomic analysis between r. solanacearum'race 3 biovar 2' (r3bv2) strains, we identified a 77 kb region in strain uw551 which is specifically absent in the hypoaggressive strain ipo1609. we proved that ipo1609 indeed carries a 77 kb genomic deletion and provide genetic evidence that occurrence of ...201122050636
structure and molecular evolution of cdgsh iron-sulfur domains.the recently discovered cdgsh iron-sulfur domains (cisds) are classified into seven major types with a wide distribution throughout the three domains of life. the type 1 protein mitoneet has been shown to fold into a dimer with the signature cdgsh motif binding to a [2fe-2s] cluster. however, the structures of all other types of cisds were unknown. here we report the crystal structures of type 3, 4, and 6 cisds determined at 1.5 å, 1.8 å and 1.15 å resolution, respectively. the type 3 and 4 cisd ...201121949752
interaction between poly(3-hydroxybutyrate) granule-associated proteins as revealed by two-hybrid analysis and identification of a new phasin in ralstonia eutropha.a large number of polypeptides are attached to phb granules of ralstonia eutropha such as phb synthase (phac1), several phb depolymerases (phazs) and phasins (phaps), regulator protein pharreu and possibly others. in this study we used the bacterial adenylate cyclase-based two hybrid assay to investigate interactions between known phb granule associated proteins (pgaps) and to screen for new pgaps. the utility of the system was tested by in vivo verification of previously postulated interaction ...201121737497
Implications of various phosphoenolpyruvate-carbohydrate phosphotransferase system mutations on glycerol utilization and poly(3-hydroxybutyrate) accumulation in Ralstonia eutropha H16.ABSTRACT: The enhanced global biodiesel production is also yielding increased quantities of glycerol as main coproduct. An effective application of glycerol, for example, as low-cost substrate for microbial growth in industrial fermentation processes to specific products will reduce the production costs for biodiesel. Our study focuses on the utilization of glycerol as a cheap carbon source during cultivation of the thermoplastic producing bacterium Ralstonia eutropha H16, and on the investigati ...201121906371
growth and localization of polyhydroxybutyrate granules in ralstonia eutropha.the bacterium ralstonia eutropha forms cytoplasmic granules of polyhydroxybutyrate that are a source of biodegradable thermoplastic. while much is known about the biochemistry of polyhydroxybutyrate production, the cell biology of granule formation and growth remain unclear. previous studies have suggested that granules form either in the inner membrane, on a central scaffold, or in the cytoplasm. here we used electron cryo-tomography to monitor granule genesis and development in 3-d in a near-n ...201122178974
microbial preference for different size classes of organic carbon: a study from antarctic snow.significance of carbon cycling in polar ecosystems is well recognized. yet, bacteria in surface snow have received less attention in terms of their potential in carbon cycling. here, we present results on carbon utilization by bacterial communities in three surface snow samples from antarctica collected along a coastal to inland transect. microcosm studies were conducted over 8 days at 5 ± 1°c to study carbon metabolism in different combinations of added low molecular weight (lmw (glucose, <1 kd ...201122037862
antibacterial activity of the flavonoids from dalbergia odorifera on ralstonia solanacearum.phytohemical investigation on the heartwood of dalbergia odorifera resulted in the isolation of nine flavonoids. their structures were elucidated as sativanone (1), (3r)-vestitone (2), (3r)-2',3',7-trihydroxy-4'-methoxyisoflavanone (3), (3r)-4'-methoxy-2',3,7-trihydroxyisoflavanone (4), carthamidin (5), liquiritigenin (6), isoliquiritigenin (7), (3r)-vestitol (8), and sulfuretin (9) based on their spectral data. all compounds were evaluated for their inhibitory activity against ralstonia solanac ...201122117168
a chromosomal insertion toolbox for promoter probing, mutant complementation and pathogenicity studies in ralstonia solanacearum.we describe here the construction of a delivery system for stable and directed insertion of gene constructs in a permissive chromosomal site of the bacterial wilt pathogen ralstonia solanacearum. the system consists of a collection of suicide vectors -the prc series- that carry an integration element flanked by transcription terminators and two sequences of homology to the chromosome of strain gmi1000, where the integration element is inserted through a double recombination event. unique restric ...201122122329
production of 3-hydroxypropionate homopolymer and poly(3-hydroxypropionate-co-4-hydroxybutyrate) copolymer by recombinant escherichia coli.conversion of 3-hydroxypropionate (3hp) from 1,3-propanediol (pdo) was improved by expressing dehydratase gene (dhat) and aldehyde dehydrogenase gene (aldd) of pseudomonas putida kt2442 under the promoter of phacab operon from ralstonia eutropha h16. expression of these genes in aeromonas hydrophila 4ak4 produced up to 21 g/l 3hp in a fermentation process. to synthesize homopolymer poly(3-hydroxypropionate) (p3hp), and copolymer poly(3-hydroxypropionate-co-3-hydroxybutyrate) (p3hp4hb), dhat and ...201122024131
nad(h)-coupled hydrogen cycling - structure-function relationships of bidirectional [nife] hydrogenases.hydrogenases catalyze the activation or production of molecular hydrogen. due to their potential importance for future biotechnological applications, these enzymes have been in the focus of intense research for the past decades. bidirectional [nife] hydrogenases are of particular interest as they couple the reversible cleavage of hydrogen to the redox conversion of nad(h). in this account, we review the current state of knowledge about mechanistic aspects and structural determinants of these com ...201122056977
inhibition of tobacco bacterial wilt with sulfone derivatives containing an 1,3,4-oxadiazole moiety.a series of new sulfone compounds containing the 1,3,4-oxadiazole moiety were designed and synthesized. their structures were identified by (1)h and (13)c nuclear magnetic resonance and elemental analyses. antibacterial bioassays indicated that most compounds exhibited promising in vitro antibacterial bioactivities against tobacco bacterial wilt at 200 μg/ml. the relationship between structure and antibacterial activity was also discussed. among the title compounds, 5'c, 5'h, 5'i, and 5'j could ...201122208183
improved biovar test for ralstonia solanacearum.race 3, biovar 2 strains of ralstonia solanacearum are quarantined pathogens in europe and canada and select agent pathogens in the united states. the biovar classification of r. solanacearum strains is based on their biochemical abilities to utilize a carbohydrate panel. the standard biovar test uses bromothymol blue as a ph indicator in 15ml culture tubes containing 3 to 5ml of test media, and takes weeks to complete at 24 or 28°c. we improved the biovar test by using phenol red as a ph indica ...201122200550
ralstonia syzygii, the blood disease bacterium and some asian r. solanacearum strains form a single genomic species despite divergent lifestyles.the ralstonia solanacearum species complex includes r. solanacearum, r. syzygii, and the blood disease bacterium (bdb). all colonize plant xylem vessels and cause wilt diseases, but with significant biological differences. r. solanacearum is a soilborne bacterium that infects the roots of a broad range of plants. r. syzygii causes sumatra disease of clove trees and is actively transmitted by cercopoid insects. bdb is also pathogenic to a single host, banana, and is transmitted by pollinating ins ...201121931687
ralstonia solanacearum δpgi-1 strain kzr-5 is affected in growth, response to cold stress and invasion of tomato.the survival and persistence of ralstonia solanacearum biovar 2 in temperate climates is still poorly understood. to assess whether genomic variants of the organism show adaptation to local conditions, we compared the behaviour of environmental strain kzr-5, which underwent a deletion of the 17.6 kb genomic island pgi-1, with that of environmental strain kzr-1 and potato-derived strains 1609 and 715. pgi-1 harbours two genes of potential ecological relevance, i.e. one encoding a hypothetical pro ...201120717661
ralstonia solanacearum virulence increased following large interstrain gene transfers by natural transformation.horizontal gene transfer (hgt) is a major driving force of evolution and is also likely to play an important role in the threatening emergence of novel pathogens, especially if it involves distantly related strains with substantially different pathogenicity. in this study, the impact of natural transformation on pathogenicity in six strains belonging to the four phylotypes of the plant-pathogenic bacterium ralstonia solanacearum was investigated. the study focused on genomic regions that vary be ...201121190441
the maturation factors hoxr and hoxt contribute to oxygen tolerance of membrane-bound [nife] hydrogenase in ralstonia eutropha h16.the membrane-bound [nife] hydrogenase (mbh) of ralstonia eutropha h16 undergoes a complex maturation process comprising cofactor assembly and incorporation, subunit oligomerization, and finally twin-arginine-dependent membrane translocation. due to its outstanding o(2) and co tolerance, the mbh is of biotechnological interest and serves as a molecular model for a robust hydrogen catalyst. adaptation of the enzyme to oxygen exposure has to take into account not only the catalytic reaction but als ...201121441514
structure of ralstonia eutropha flavohemoglobin in complex with three antibiotic azole compounds.flavohemoglobins (flavohbs) are enzymes that operate primarily as nitric oxide dioxygenases and shuttle thereby electrons among nad(p)h, fad, heme, and a ligated redox-active substrate such as o(2). they function in the bacterial defense against nitrosative stress and are therefore considered as targets for new antibiotic drugs. recently, azole derivatives were proven to be attractive nitric oxide dioxygenase inhibitors, and to explore their binding characteristics, we determined the x-ray struc ...201121210640
ralfuranone biosynthesis in ralstonia solanacearum suggests functional divergence in the quinone synthetase family of enzymes.ralstonia solanacearum is a destructive crop plant pathogen and produces ralfuranone, i.e., a monophenyl-substituted furanone. extensive feeding experiments with (13)c-labeled l-phenylalanine now proved that all carbon atoms of the heterocycle derive, after deamination, from this aromatic amino acid. a genetic locus was identified which encodes the aminotransferase rald and the furanone synthetase rala. the latter is a tridomain nonribosomal peptide synthetase (nrps)-like enzyme which was charac ...201121439480
a unique iron-sulfur cluster is crucial for oxygen tolerance of a [nife]-hydrogenase.hydrogenases are essential for h(2) cycling in microbial metabolism and serve as valuable blueprints for h(2)-based biotechnological applications. however, most hydrogenases are extremely oxygen sensitive and prone to inactivation by even traces of o(2). the o(2)-tolerant membrane-bound [nife]-hydrogenase of ralstonia eutropha h16 is one of the few examples that can perform h(2) uptake in the presence of ambient o(2). here we show that o(2) tolerance is crucially related to a modification of the ...201121390036
new detection systems of bacteria using highly selective media designed by smart: selective medium-design algorithm restricted by two constraints.culturing is an indispensable technique in microbiological research, and culturing with selective media has played a crucial role in the detection of pathogenic microorganisms and the isolation of commercially useful microorganisms from environmental samples. although numerous selective media have been developed in empirical studies, unintended microorganisms often grow on such media probably due to the enormous numbers of microorganisms in the environment. here, we present a novel strategy for ...201121304596
endo- and exopolygalacturonases of ralstonia solanacearum are inhibited by polygalacturonase-inhibiting protein (pgip) activity in tomato stem extracts.polygalacturonases (pgs) of wild-type and non-virulent phenotype conversion mutant (pc) strains of ralstonia solanacearum were compared by investigating their activities and their inhibition by polygalacturonase-inhibiting proteins (pgips) from tomato stems. in cultures of wild-type strain toudk2, slimy (s), retarded slimy (rs) and non-slimy (ns) colonies appeared. the conversion of the 's' into the 'rs' colony form coincided with the beginning of pg production. pg activity of the pc strain incr ...201121367611
facultative methylotrophs from the human oral cavity and methylotrophy in strains of gordonia, leifsonia, and microbacterium.we show that bacteria with methylotrophic potential are ubiquitous in the human mouth microbiota. numerous strains of actinobacteria (brevibacterium, gordonia, leifsonia, microbacterium, micrococcus, rhodococcus) and proteobacteria (achromobacter, klebsiella, methylobacterium, pseudomonas, ralstonia) were isolated, and one strain of each of the eleven genera was studied in detail. these strains expressed enzymes associated with methylotrophic metabolism (methanol, methylamine, and formate dehydr ...201121374057
growth and polyhydroxybutyrate production by ralstonia eutropha in emulsified plant oil medium.polyhydroxyalkanoates (phas) are natural polyesters synthesized by bacteria for carbon and energy storage that also have commercial potential as bioplastics. one promising class of carbon feedstocks for industrial pha production is plant oils, due to the high carbon content of these compounds. the bacterium ralstonia eutropha accumulates high levels of pha and can effectively utilize plant oil. growth experiments that include plant oil, however, are difficult to conduct in a quantitative and rep ...201121279345
versatile metabolic adaptations of ralstonia eutropha h16 to a loss of pdhl, the e3 component of the pyruvate dehydrogenase complex.a previous study reported that the tn5-induced poly(3-hydroxybutyric acid) (phb)-leaky mutant ralstonia eutropha h1482 showed a reduced phb synthesis rate and significantly lower dihydrolipoamide dehydrogenase (dhldh) activity than the wild-type r. eutropha h16 but similar growth behavior. insertion of tn5 was localized in the pdhl gene encoding the dhldh (e3 component) of the pyruvate dehydrogenase complex (pdhc). taking advantage of the available genome sequence of r. eutropha h16, observation ...201121296938
ralstonia solanacearum extracellular polysaccharide is a specific elicitor of defense responses in wilt-resistant tomato plants.ralstonia solanacearum, which causes bacterial wilt of diverse plants, produces copious extracellular polysaccharide (eps), a major virulence factor. the function of eps in wilt disease is uncertain. leading hypotheses are that eps physically obstructs plant water transport, or that eps cloaks the bacterium from host plant recognition and subsequent defense. tomato plants infected with r. solanacearum race 3 biovar 2 strain uw551 and tropical strain gmi1000 upregulated genes in both the ethylene ...201121253019
improved detergent-based recovery of polyhydroxyalkanoates (phas).extracting polyhydroxyalkanoate (pha) polymer from bacterial cells often involves harsh conditions, including use of environmentally harmful solvents. we evaluated different detergents under various conditions to extract pha from ralstonia eutropha and escherichia coli cells. most detergents tested recovered highly pure pha polymer from cells in amounts that depended on the percentage of polymer present in the cell. detergents such as linear alkylbenzene sulfonic acid (las-99) produced a high yi ...201121207109
production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in recombinant corynebacterium glutamicum using propionate as a precursor.lipopolysaccharides free p[3-hydroxybutyrate (3hb)-co-3-hydroxyvalerate (3hv)] production was achieved using recombinant corynebacterium glutamicum harboring polyhydroxyalkanoate (pha) biosynthetic genes from ralstonia eutropha. cells grown on glucose with feeding of propionate as a precursor of 3hv unit accumulated 8-47wt% of p(3hb-co-3hv). the 3hv fraction in the copolymer was varied from 0 to 28mol% depending on the propionate concentrations.201120692303
complex function by design using spatially pre-structured synthetic microbial communities: degradation of pentachlorophenol in the presence of hg(ii).naturally occurring microbes perform a variety of useful functions, with more complex processes requiring multiple functions performed by communities of multiple microbes. synthetic biology via genetic engineering may be used to achieve desired multiple functions, e.g. multistep chemical and biological transformations, by adding genes to a single organism, but this is sometimes not possible due to incompatible metabolic requirements or not desirable in certain applications, especially in medical ...201120717565
bacterial wilt resistance in tomato, pepper, and eggplant: genetic resources respond to diverse strains in the ralstonia solanacearum species complex.bacterial wilt, caused by strains belonging to the ralstonia solanacearum species complex, inflicts severe economic losses in many crops worldwide. host resistance remains the most effective control strategy against this disease. however, wilt resistance is often overcome due to the considerable variation among pathogen strains. to help breeders circumvent this problem, we assembled a worldwide collection of 30 accessions of tomato, eggplant and pepper (core-tep), most of which are commonly used ...201120795852
characterization and functional analyses of r-specific enoyl coenzyme a hydratases in polyhydroxyalkanoate-producing ralstonia eutropha.a genome survey of polyhydroxyalkanoate (pha)-producing ralstonia eutropha h16 detected the presence of 16 orthologs of r-specific enoyl coenzyme a (enoyl-coa) hydratase, among which three proteins shared high homologies with the enzyme specific to enoyl-coas of medium chain length encoded by phaj4 from pseudomonas aeruginosa (phaj4(pa)). the recombinant forms of the three proteins, termed phaj4a(re) to phaj4c(re), actually showed enoyl-coa hydratase activity with r specificity, and the catalyti ...201222081565
predicting metabolic pathways by sub-network extraction.various methods result in groups of functionally related genes obtained from genomes (operons, regulons, syntheny groups, and phylogenetic profiles), transcriptomes (co-expression groups) and proteomes (modules of interacting proteins). when such groups contain two or more enzyme-coding genes, graph analysis methods can be applied to extract a metabolic pathway that interconnects them. we describe here the way to use the pathway extraction tool available on the neat web server ( ...201222144151
Coupling of permeabilized cells of Gluconobacter oxydans and Ralstonia eutropha for asymmetric ketone reduction using H(2) as reductant.A combined two-cell reaction system containing Gluconobacter oxydans and Ralstonia eutropha was evaluated with regard to asymmetric ketone reduction using H(2) as the reductant. Whole cells permeabilized by EDTA/toluene were used, and synthesis was performed in a biphasic aqueous/organic reaction medium. The two-cell system was compared with a system in which G. oxydans alone was used for both ketone reduction and cofactor regeneration, using an alcohol as co-substrate. The two-cell system exhib ...201222001848
characterization of biofumigated ralstonia solanacearum cells using micro-raman spectroscopy and electron microscopy.essential oils of palmarosa, lemongrass, and eucalyptus have shown promise as biofumigants for control of the bacterial wilt disease of edible ginger (zingiber officinale) caused by ralstonia solanacearum race 4 in previous potting medium studies. biochemical changes in r. solanacearum cells were evaluated with micro-raman spectroscopy following treatment with essential oils at different concentrations (0.04, 0.07, and 0.14% [vol/vol] of culture medium) and changes in cell structure were observe ...201221899389
the origin and ecological significance of multiple branches for histidine utilization in pseudomonas aeruginosa pao1.pseudomonas proliferate in a wide spectrum of harsh and variable environments. in many of these environments, amino acids, such as histidine, are a valuable source of carbon, nitrogen and energy. here, we demonstrate that the histidine uptake and utilization (hut) pathway of pseudomonas aeruginosa pao1 contains two branches from the intermediate formiminoglutamate to the product glutamate. genetic analysis revealed that the four-step route is dispensable as long as the five-step route is present ...201222225844
Rapid selection of glucose-utilizing variants of the polyhydroxyalkanoate producer Ralstonia eutropha H16 by incubation with high substrate levels.Aims: The application of Ralstonia eutropha H16 for producing polyhydroxyalkanoates as bioplastics is limited by the incapability of the bacterium to utilize glucose as a growth substrate. This study aims in characterizing glucose-utilizing strains that arose after incubation with high glucose levels, in comparison with previously published mutants, generated either by mutagenesis or by metabolic engineering. Methods and Results: Cultivations on solid and liquid media showed that the applicati ...201222044343
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