| novel precursor substrates for polythioesters (pte) and limits of pte biosynthesis in ralstonia eutropha. | a novel class of biopolymers referred to as polythioesters (pte) was recently detected when the polyhydroxyalkanoate (pha) accumulating bacterium ralstonia eutropha was cultivated in the presence of 3-mercaptopropionic acid (3mp) or 3,3'-thiodipropionic acid (tdp). in this study, 3,3'-dithiodipropionic acid (dtdp) and 3-mercaptovaleric acid (3mv) were identified as two additional precursor carbon sources for in vivo biosynthesis of pte in r. eutropha. biosynthesis of copolymers of 3-hydroxybutyr ... | 2003 | 12725926 |
| molecular organization of exopolysaccharide (eps) encoding genes on the lactococcal bacteriophage adsorption blocking plasmid, pci658. | the lactococcal plasmid pci658 (58 kb) isolated from lactococcus lactis ssp. cremoris ho2 encodes the production of a hydrophilic exopolysaccharide (eps) which consists primarily of galactose and glucuronic acid and which interferes with adsorption of phages ø712 and øc2 to cell surface receptors. examination of the nucleotide sequence of a 21.8-kb region of the plasmid revealed a large genetic cluster consisting of at least 23 putative eps biosynthetic determinants in addition to the presence o ... | 2003 | 12726766 |
| quorum sensing in plant-pathogenic bacteria. | quorum sensing (qs) allows bacteria to assess their local population density and/or physical confinement via the secretion and detection of small, diffusible signal molecules. this review describes how phytopathogenic bacteria have incorporated qs mechanisms into complex regulatory cascades that control genes for pathogenicity and colonization of host surfaces. traits regulated by qs include the production of extracellular polysaccharides, degradative enzymes, antibiotics, siderophores, and pigm ... | 2003 | 12730390 |
| bacterial conversion of hydroxylamino aromatic compounds by both lyase and mutase enzymes involves intramolecular transfer of hydroxyl groups. | hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. the origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). the conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from pseudomonas pseudoalcaligenes js45 proceeds by an intramolecular hydroxyl tr ... | 2003 | 12732549 |
| crystal structure of fungal lectin: six-bladed beta-propeller fold and novel fucose recognition mode for aleuria aurantia lectin. | aleuria aurantia lectin is a fungal protein composed of two identical 312-amino acid subunits that specifically recognizes fucosylated glycans. the crystal structure of the lectin complexed with fucose reveals that each monomer consists of a six-bladed beta-propeller fold and of a small antiparallel two-stranded beta-sheet that plays a role in dimerization. five fucose residues were located in binding pockets between the adjacent propeller blades. due to repeats in the amino acid sequence, there ... | 2003 | 12732625 |
| sepsis, multiple organ failure, and death due to pandoraea pnomenusa infection after lung transplantation. | a 30-year-old man died with pandoraea pnomenusa sepsis after lung transplantation. pandoraea species are gram-negative rods, closely related to, and commonly misidentified as, burkholderia cepacia complex or ralstonia species. heretofore considered soil bacteria and colonizers that infect patients with chronic lung diseases, pandoraea species can produce severe infections. | 2003 | 12734295 |
| mechanism of the polymerization reaction initiated and catalyzed by the polyhydroxybutyrate synthase of ralstonia eutropha. | polyhydroxybutyrate (phb) synthases (polymerases) catalyze the polymerization of the coenzyme a thioester of 3-hydroxybutyrate to phb. the ralstonia eutropha phb synthase purified from recombinant e. coli cells exists in aqueous solution in both monomeric (single subunit) and homodimeric (two subunits) forms in equilibrium. several lines of evidence suggest that the homodimer is the active form of the synthase. the initial mechanistic model for the polymerization reaction proposed that two diffe ... | 2003 | 12741763 |
| ectopic expression of ralstonia solanacearum effector protein popa early in invasion results in loss of virulence. | ralstonia solanacearum oe1-1 (oe1-1) is pathogenic to tobacco. the type iii-secreted effector protein popa of oe1-1 showed 97.6% identity to popa of r. solanacearum gmi1000, which is not pathogenic to tobacco. reverse transcription-polymerase chain reaction analysis showed that popa in oe1-1 was expressed at 3 h after inoculation (hai), but not before, in infiltrated-tobacco leaves. pathogenicity analysis using a popabc operon-deleted mutant of oe1-1 (deltaabc) showed that popabc is not directly ... | 2003 | 12744516 |
| purification and properties of an intracellular 3-hydroxybutyrate-oligomer hydrolase (phaz2) in ralstonia eutropha h16 and its identification as a novel intracellular poly(3-hydroxybutyrate) depolymerase. | an intracellular 3-hydroxybutyrate (3hb)-oligomer hydrolase (phaz2(reu)) of ralstonia eutropha was purified from escherichia coli harboring a plasmid containing phaz2(reu). the purified enzyme hydrolyzed linear and cyclic 3hb-oligomers. although it did not degrade crystalline poly(3-hydroxybutyrate) (phb), the purified enzyme degraded artificial amorphous phb at a rate similar to that of the previously identified intracellular phb (iphb) depolymerase (phaz1(reu)). the enzyme appeared to be an en ... | 2003 | 12775684 |
| characterization of the second lysr-type regulator in the biphenyl-catabolic gene cluster of pseudomonas pseudoalcaligenes kf707. | pseudomonas pseudoalcaligenes kf707 possesses a biphenyl-catabolic (bph) gene cluster consisting of bphr1a1a2-(orf3)-bpha3a4bcx0x1x2x3d. the bphr1 (formerly orf0) gene product, which belongs to the gntr family, is a positive regulator for itself and bphx0x1x2x3d. further analysis in this study revealed that a second regulator belonging to the lysr family (designated bphr2) is involved in the regulation of the bph genes in kf707. the bphr2 gene was not located near the bph gene cluster, and its p ... | 2003 | 12775695 |
| inhibitory effect of carbon dioxide on the fed-batch culture of ralstonia eutropha: evaluation by co2 pulse injection and autogenous co2 methods. | in order to see the effect of co(2) inhibition resulting from the use of pure oxygen, we carried out a comparative fed-batch culture study of polyhydroxybutyric acid (phb) production by ralstonia eutropha using air and pure oxygen in 5-l, 30-l, and 300-l fermentors. the final phb concentrations obtained with pure o(2) were 138.7 g/l in the 5-l fermentor and 131.3 g/l in the 30-l fermentor, which increased 2.9 and 6.2 times, respectively, as compared to those obtained with air. in the 300-l ferme ... | 2003 | 12783487 |
| assessment of bioavailability of soil-sorbed atrazine. | bioavailability of pesticides sorbed to soils is an important determinant of their environmental fate and impact. mineralization of sorbed atrazine was studied in soil and clay slurries, and a desorption-biodegradation-mineralization (dbm) model was developed to quantitatively evaluate the bioavailability of sorbed atrazine. three atrazine-degrading bacteria that utilized atrazine as a sole n source (pseudomonas sp. strain adp, agrobacterium radiobacter strain j14a, and ralstonia sp. strain m91- ... | 2003 | 12788728 |
| metabolic engineering of escherichia coli for production of enantiomerically pure (r)-(--)-hydroxycarboxylic acids. | a heterologous metabolism of polyhydroxyalkanoate (pha) biosynthesis and degradation was established in escherichia coli by introducing the ralstonia eutropha pha biosynthesis operon along with the r. eutropha intracellular pha depolymerase gene. by with this metabolically engineered e. coli, enantiomerically pure (r)-3-hydroxybutyric acid (r3hb) could be efficiently produced from glucose. by employing a two-plasmid system, developed as the pha biosynthesis operon on a medium-copy-number plasmid ... | 2003 | 12788745 |
| physical interaction between rrs1-r, a protein conferring resistance to bacterial wilt, and popp2, a type iii effector targeted to the plant nucleus. | rrs1-r confers broad-spectrum resistance to several strains of the causal agent of bacterial wilt, ralstonia solanacearum. although genetically defined as recessive, this r gene encodes a protein whose structure combines the tir-nbs-lrr domains found in several r proteins and a wrky motif characteristic of some plant transcriptional factors and behaves as a dominant gene in transgenic susceptible plants. here we show that popp2, a r. solanacearum type iii effector, which belongs to the yopj/avrr ... | 2003 | 12788974 |
| characterization of a ralstonia solanacearum operon required for polygalacturonate degradation and uptake of galacturonic acid. | the bacterial wilt pathogen ralstonia solanacearum produces three extracellular polygalacturonases (pgs): peha, pehb, and pehc. all three pgs hydrolyze pectin's polygalacturonic acid backbone, but each releases different reaction products. peha and pehb contribute significantly to pathogen virulence, probably by facilitating root invasion and colonization. to determine the collective contribution of pgs to virulence and saprophytic survival, we cloned, characterized, and mutated the r. solanacea ... | 2003 | 12795379 |
| tetratricopeptide-like repeats in type-iii-secretion chaperones and regulators. | efficient type-iii secretion depends on cytosolic molecular chaperones, which bind specifically to the translocators and effectors. in the past there has been a tendency to shoe-horn all type-iii-secretion chaperones into a single structural and functional class. however, we have shown that the lcrh/sycd-like chaperones consist of three central tetratricopeptide-like repeats that are predicted to fold into an all-alpha-helical array that is quite distinct from the known structure of the syce cla ... | 2003 | 12799000 |
| seminal infection with ralstonia picketti and cytolysosomal spermophagy in a previously fertile man. | to determine the origin of large plaque-like cellular and acellular masses of debris found in the semen of a patient with otherwise normal semen quality and secondary infertility. | 2003 | 12801579 |
| a chitinase with high activity toward partially n-acetylated chitosan from a new, moderately thermophilic, chitin-degrading bacterium, ralstonia sp. a-471. | a moderately thermophilic bacterium, strain a-471, capable of degrading chitin was isolated from a composting system of chitin-containing waste. analysis of the 16s rdna sequence revealed that the bacterium belongs to the genus ralstonia. a thermostable chitinase a ( ra-chia) was purified from culture fluid of the bacterium grown in colloidal chitin medium. purification of the enzyme was achieved mainly by exploiting its binding to the colloidal chitin. the molecular mass of the enzyme was estim ... | 2004 | 12802528 |
| ralstonia eutropha h16 encodes two and possibly three intracellular poly[d-(-)-3-hydroxybutyrate] depolymerase genes. | intracellular poly[d-(-)-3-hydroxybutyrate] (phb) depolymerases degrade phb granules to oligomers and monomers of 3-hydroxybutyric acid. recently an intracellular phb depolymerase gene (phaz1) from ralstonia eutropha was identified. we now report identification of candidate phb depolymerase genes from r. eutropha, namely, phaz2 and phaz3, and their characterization in vivo. phaz1 was used to identify two candidate depolymerase genes in the genome of ralstonia metallidurans. phaz1 and these genes ... | 2003 | 12813072 |
| expression of the nitroarene dioxygenase genes in comamonas sp. strain js765 and acidovorax sp. strain js42 is induced by multiple aromatic compounds. | this work reports a genetic analysis of the expression of nitrobenzene dioxygenase (nbdo) in comamonas sp. strain js765 and 2-nitrotoluene dioxygenase (2ntdo) in acidovorax sp. strain js42. strains js765 and js42 possess identical lysr-type regulatory proteins, nbzr and ntdr, respectively. nbzr/ntdr is homologous to nahr, the positive salicylate-responsive transcriptional activator of the naphthalene degradation genes in pseudomonas putida g7. the genes encoding nbdo and 2ntdo in each strain are ... | 2003 | 12813084 |
| efflux-mediated heavy metal resistance in prokaryotes. | what makes a heavy metal resistant bacterium heavy metal resistant? the mechanisms of action, physiological functions, and distribution of metal-exporting proteins are outlined, namely: cba efflux pumps driven by proteins of the resistance-nodulation-cell division superfamily, p-type atpases, cation diffusion facilitator and chromate proteins, nreb- and cnrt-like resistance factors. the complement of efflux systems of 63 sequenced prokaryotes was compared with that of the heavy metal resistant b ... | 2003 | 12829273 |
| ralstonia metallidurans, a bacterium specifically adapted to toxic metals: towards a catalogue of metal-responsive genes. | ralstonia metallidurans, formerly known as alcaligenes eutrophus and thereafter as ralstonia eutropha, is a beta-proteobacterium colonizing industrial sediments, soils or wastes with a high content of heavy metals. the type strain ch34 carries two large plasmids (pmol28 and pmol30) bearing a variety of genes for metal resistance. a chronological overview describes the progress made in the knowledge of the plasmid-borne metal resistance mechanisms, the genetics of r. metallidurans ch34 and its ta ... | 2003 | 12829276 |
| use of amplified ribosomal dna restriction analysis for identification of ralstonia and pandoraea species: interest in determination of the respiratory bacterial flora in patients with cystic fibrosis. | the recovery of ralstonia and pandoraea species from respiratory tract cultures of patients with cystic fibrosis has recently been reported. these species are difficult to identify, and especially to differentiate from burkholderia cepacia complex organisms, with classical methods. the discriminatory power of amplified ribosomal dna restriction analysis (ardra) within the two genera was assessed by comparing the restriction profiles of reference strains of each species by using a panel of six en ... | 2003 | 12843108 |
| the multifunctional isopropyl alcohol dehydrogenase of phytomonas sp. could be the result of a horizontal gene transfer from a bacterium to the trypanosomatid lineage. | isopropyl alcohol dehydrogenase (ipdh) is a dimeric mitochondrial alcohol dehydrogenase (adh), so far detected within the trypanosomatidae only in the genus phytomonas. the cloning, sequencing, and heterologous expression of the two gene alleles of the enzyme revealed that it is a zinc-dependent medium-chain adh. both polypeptides have 361 amino acids. a mitochondrial targeting sequence was identified. the mature proteins each have 348 amino acids and a calculated molecular mass of 37 kda. they ... | 2003 | 12853449 |
| quantitative structure-activity relationship (qsar) analysis of aromatic effector specificity in ntrc-like transcriptional activators from aromatic oxidizing bacteria. | a quantitative structure-activity relationship (qsar) approach was taken to provide mechanistic insights into the interaction between the chemical structure of inducing compounds and the transcriptional activation of aromatic monooxygenase operons among the xylr/dmpr subclass of bacterial ntrc-like transcriptional regulators. compared to xylr and dmpr, a broader spectrum of effector compounds was observed for the tbut system from ralstonia pickettii pko1. the results of qsar analysis for tbut su ... | 2003 | 12855166 |
| interplay of the czc system and two p-type atpases in conferring metal resistance to ralstonia metallidurans. | cadmium and zinc are removed from cells of ralstonia metallidurans by the czccba efflux pump and by two soft-metal-transporting p-type atpases, cada and znta. the czccba genes are located on plasmid pmol30, and the cada and znta genes are on the bacterial chromosome. expression of znta from r. metallidurans in escherichia coli predominantly mediated resistance to zinc, and expression of cada predominantly mediated resistance to cadmium. both transporters decreased the cellular content of zinc or ... | 2003 | 12867443 |
| purification and crystallization of a lysr-type transcriptional regulator cbnr from ralstonia eutropha nh9. | cbnr, a lysr-type transcriptional regulator from ralstonia eutropha nh9, has been crystallized by the vapor-diffusion method. it is intriguing to note that the different mixing ratios between the protein and reservoir solutions resulted in the different crystal forms. these crystals have the symmetry of the orthorhombic system with space groups p2(1)1(i)2 and p2(1)2(1)2(1). | 2003 | 12871153 |
| first step towards a quantitative model describing czc-mediated heavy metal resistance in ralstonia metallidurans. | quantitative models were derived to explain heavy metal resistance in ralstonia metallidurans. a deltaczca deletion of the gene for the central component of the co2+/zn2+/cd2+ efflux system czccba combined with the expression level of czccba as studied with a phi(czcc-lacz-czcba) operon fusion demonstrated that czccba was the only prerequisite for resistance to co2+/zn2+/cd2+ at concentrations of 200 microm and above. the cellular content of the czca protein (resistance nodulation cell division ... | 2003 | 12877469 |
| recovery of poly(3-hydroxybutyrate) from high cell density culture of ralstonia eutropha by direct addition of sodium dodecyl sulfate. | a simple and effective method for the recovery poly(3-hydroxybutyrate) [p(3hb)] directly from high cell density culture broth with no pretreatment steps has been developed. this method consists of direct addition of sodium dodecyl sulfate (sds) to the culture broth, shaking, heat treatment, and washing steps. when the sds/biomass ratio was higher than 0.4, the purity of recovered p(3hb) was over 95% for various cell concentrations of 50-300 g dry cell l(-1), with the highest value of 97%. the re ... | 2003 | 12882307 |
| substrate inhibition kinetics for toluene and benzene degrading pure cultures and a method for collection and analysis of respirometric data for strongly inhibited cultures. | we present an evaluation of the qualitative and quantitative effects that high concentrations of benzene and toluene have on the growth rate of several pure cultures that use these compounds as their sole carbon and energy source. the cultures employed were five widely studied environmental isolates: pseudomonas putida f1, p. putida mt2, p. mendocina kr, ralstonia pickettii pko1, and burkholderia cepacia g4. three cultures degraded toluene following a pattern consistent with the kinetic model of ... | 2003 | 12889020 |
| host plant-dependent phenotypic reversion of ralstonia solanacearum from non-pathogenic to pathogenic forms via alterations in the phca gene. | ralstonia solanacearum is a plant pathogenic bacterium that undergoes a spontaneous phenotypic conversion (pc) from a wild-type pathogenic to a non-pathogenic form. pc is often associated with mutations in phca, which is a key virulence regulatory gene. until now, reversion to the wild-type pathogenic form has not been observed for pc variants and the biological significance of pc has been questioned. in this study, we characterized various alterations in phca (eight is element insertions, three ... | 2003 | 12890023 |
| classification of ralstonia pickettii-like isolates from the environment and clinical samples as ralstonia insidiosa sp. nov. | thirteen ralstonia pickettii-like isolates from the environment (water, soil and activated sludge) and human clinical samples (including respiratory secretions of cystic fibrosis patients) were investigated in a polyphasic taxonomic study that employed 16s rdna sequence analysis, dna-dna hybridization, determination of dna base composition, whole-cell protein analysis, biochemical characterization and pcr-based assays. all isolates were classified as a novel ralstonia species, for which the name ... | 2003 | 12892129 |
| polychlorinated biphenyl (pcb) degradation and persistence of a gfp-marked ralstonia eutropha h850 in pcb-contaminated soil. | ralstonia eutropha h850 was labelled chromosomally with a gfp marker gene encoding for the green fluorescent protein, and designated r. eutropha h850g13. visual observation of green fluorescent cells under an epifluorescence microscope, and pcr amplification products, confirmed that the bacterium was labelled with gfp. southern blot hybridization products further confirmed the gfp was chromosomally labelled. using resting cell assays, it was determined that insertion of the gfp gene decreased th ... | 2003 | 12898060 |
| the biphenyl- and 4-chlorobiphenyl-catabolic transposon tn4371, a member of a new family of genomic islands related to incp and ti plasmids. | the nucleotide sequence of the biphenyl catabolic transposon tn4371 has been completed and analyzed. it confirmed that the element has a mosaic structure made of several building blocks. in addition to previously identified genes coding for a tyrosine recombinase related to phage integrases and for biphenyl degradation enzymes very similar to those of achromobacter georgiopolitanum kks102, tn4371 carries many plasmid-related genes involved in replication, partition, and other, as-yet-unknown, pl ... | 2003 | 12902278 |
| production of recombinant proteins using multiple-copy gene integration in high-cell-density fermentations of ralstonia eutropha. | we have previously reported the development of a novel protein expression system based on ralstonia eutropha. in this study we report on the influence of gene copynumber on recombinant protein expression in r. eutropha. we compare recombinant gene stability and expression levels of chromosomal integration with a plasmid-based expression system. single, double, and triple copies of a gene encoding organophosphohydrolase (oph), an enzyme prone to inclusion-body formation in e. coli, were integrate ... | 2003 | 12910550 |
| spatial stochastic simulation offers potential as a quantitative method for pest risk analysis. | pest risk analysis represents an emerging field of risk analysis that evaluates the potential risks of the introduction and establishment of plant pests into a new geographic location and then assesses the management options to reduce those potential risks. development of new and adapted methodology is required to answer questions concerning pest risk analysis of exotic plant pests. this research describes a new method for predicting the potential establishment and spread of a plant pest into ne ... | 2003 | 12926559 |
| a novel antimicrobial protein isolated from potato (solanum tuberosum) shares homology with an acid phosphatase. | the nucleotide and amino acids sequences for ap(1) will appear in the genbank(r) and ncbi databases under accession number ay297449. a novel antimicrobial protein (ap(1)) was purified from leaves of the potato ( solanum tuberosum, variety ms-42.3) with a procedure involving ammonium sulphate fractionation, molecular sieve chromatography with sephacryl s-200 and hydrophobic chromatography with butyl-sepharose using a fplc system. the inhibition spectrum investigation showed that ap(1) had good in ... | 2003 | 12927022 |
| complete nucleotide sequence of phg1: a ralstonia eutropha h16 megaplasmid encoding key enzymes of h(2)-based ithoautotrophy and anaerobiosis. | the self-transmissible megaplasmid phg1 carries essential genetic information for the facultatively lithoautotrophic and facultatively anaerobic lifestyles of its host, the gram-negative soil bacterium ralstonia eutropha h16. we have determined the complete nucleotide sequence of phg1. this megaplasmid is 452,156 bp in size and carries 429 potential genes. groups of functionally related genes form loose clusters flanked by mobile elements. the largest functional group consists of lithoautotrophy ... | 2003 | 12948488 |
| [phenotypic and genotypic characteristics of non fermenting atypical strains recovered from cystic fibrosis patients]. | we used partial 16s rrna gene (16s dna) sequencing for the prospective identification of nonfermenting gram-negative bacilli recovered from patients attending our cystic fibrosis center (hôpital necker-enfants malades), which gave problematic results with conventional phenotypic tests. during 1999, we recovered 1093 isolates of nonfermenting gram-negative bacilli from 702 sputum sampled from 148 patients. forty-six of these isolates (27 patients) were not identified satisfactorily in routine lab ... | 2003 | 12948761 |
| changing concepts in the systematics of bacterial nitrogen-fixing legume symbionts. | as of february 2003, bacteria that form nitrogen-fixing symbiotic associations with legumes have been confirmed in 44 species of 12 genera. phylogenies of these taxa containing legume symbionts based on the comparative analysis of 16s rdna sequences show that they are not clustered in one lineage but are distributed in the classes alphaproteobacteria and betaproteobacteria, and dispersed over the following nine monophyletic groups, being intermingled with other taxa that do not contain legume sy ... | 2003 | 12949698 |
| hydrogen-induced structural changes at the nickel site of the regulatory [nife] hydrogenase from ralstonia eutropha detected by x-ray absorption spectroscopy. | for the first time, the nickel site of the hydrogen sensor of ralstonia eutropha, the regulatory [nife] hydrogenase (rh), was investigated by x-ray absorption spectroscopy (xas) at the nickel k-edge. the oxidation state and the atomic structure of the ni site were investigated in the rh in the absence (air-oxidized, rh(ox)) and presence of hydrogen (rh(+h2)). incubation with hydrogen is found to cause remarkable changes in the spectroscopic properties. the ni-c epr signal, indicative of ni(iii), ... | 2003 | 12974636 |
| preliminary analysis of polyhydroxyalkanoate inclusions using atomic force microscopy. | atomic force microscopy analysis of polyhydroxyalkanoate (pha) inclusions isolated from sonicated ralstonia eutropha cells revealed that they exhibit two types of surface structure and shape; rough and ovoid, or smooth and spherical. smooth inclusions possessed linear surface structures that were in parallel arrays with 7-nm spacing. occasionally, cracks or fissures could be seen on the surface of the rough inclusions, which allowed a measurement of approximately 4 nm for the thickness of the bo ... | 2003 | 13129616 |
| the naphthalene catabolic (nag) genes of ralstonia sp. strain u2 are an operon that is regulated by nagr, a lysr-type transcriptional regulator. | in ralstonia sp. strain u2, the nag catabolic genes, which encode the enzymes for the pathway that catabolizes naphthalene via the alternative ring cleavage gentisate pathway, are transcribed as an operon under the same promoter. nagr, which encodes a lysr-type transcriptional regulator, is divergently transcribed compared to the nag catabolic genes. a 4-bp frameshift deletion in nagr demonstrated that nagr is required for expression of the nag operon. the transcriptional start of the nag operon ... | 2003 | 13129957 |
| ralstonia respiraculi sp. nov., isolated from the respiratory tract of cystic fibrosis patients. | five isolates recovered from the respiratory tract of cystic fibrosis patients were included in a polyphasic taxonomic study that employed 16s rdna sequence analysis, cellular protein and fatty acid analysis and biochemical characterization. four isolates were classified as a novel ralstonia species, for which the name ralstonia respiraculi sp. nov. is proposed; the other isolate was phylogenetically closely related to r. respiraculi, but is likely to represent another novel ralstonia species. t ... | 2003 | 13130016 |
| replication functions of new broad host range plasmids isolated from polluted soils. | the nucleotide sequencing of replicons isolated from three new broad host range plasmids, pmol98, pemt8, and pemt3, originating from polluted soils, showed a typical organization of iteron replicons replicating by the theta mode. in the pmol98 replicon, the origin region and the rep gene were identified in complementation experiments. sequence comparisons showed that the regions bearing these features are highly identical to regions in pip02t and psb102 and that the rep proteins (but not the ori ... | 2003 | 14499936 |
| a new and sensitive co-operational polymerase chain reaction for rapid detection of ralstonia solanacearum in water. | three primers from 16s rrna were successfully assayed simultaneously in one reaction for sensitive detection of ralstonia solanacearum in watercourses. the protocol is a modification of the co-operational polymerase chain reaction (co-pcr), which allows the simultaneous and co-operational action of the primers. it specifically amplified r. solanacearum strains belonging to biovars 1, 2 and 4. no products were obtained from any of the 162 unidentified isolates from river water. the sensitivity of ... | 2003 | 14500017 |
| effect of integration of a gfp reporter gene on fitness of ralstonia eutropha during growth with 2,4-dichlorophenoxyacetic acid. | green fluorescent proteins (gfps) are frequently used as marker and reporter systems to assess the fate and activity of microbial strains with the ability to degrade xenobiotic compounds. to evaluate the potential of this tool for tracking herbicide-degrading microorganisms in the environment a promoterless gfp was linked to the tfd c promoter, which is activated during degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-d), and integrated into the chromosome of the 2,4-d-degrading ... | 2003 | 14510841 |
| microbial characterization of the mars odyssey spacecraft and its encapsulation facility. | microbial characterization of the mars odyssey spacecraft and the kennedy space center spacecraft assembly and encapsulation facility ii (saef-ii) was carried out by both culture-based and molecular methods. the most dominant cultivable microbes were species of bacillus, with comamonads, microbacteria and actinomycetales also represented. several spore-forming isolates were resistant to gamma-radiation, uv, h2o2 and desiccation, and one acinetobacter radioresistens isolate and several aureobasid ... | 2003 | 14510851 |
| mutagenesis study on the role of a lysine residue highly conserved in formate dehydrogenases and periplasmic nitrate reductases. | lysine 85 (k85) in the primary structure of the catalytic subunit of the periplasmic nitrate reductase (nap-a) of ralstonia eutropha h16 is highly conserved in periplasmic nitrate reductases and in the structurally related catalytic subunit of the formate dehydrogenases of various bacterial species. it is located between an [4fe-4s] center and one of the molybdopterin-guanine dinucleotides mediating the through bonds electron flow to convert the specific substrate of the respective enzymes. to e ... | 2003 | 14511645 |
| poly(3-hydroxybutyrate) synthesis in fed-batch culture of ralstonia eutropha with phosphate limitation under different glucose concentrations. | poly(3-hydroxybutyrate) (phb) was produced by fed-batch cultures of ralstonia eutropha with phosphate limitation under different glucose concentrations. when glucose was kept at 2.5 g l(-1), cell growth and phb synthesis were limited due to the shortage of carbon source but a higher phb content occurred in the cell-growth stage. this shows that a low glucose concentration is favorable for phb accumulation in r. eutropha. phb obtained with glucose at 9 g l(-1) is 1.6 times that obtained with 40 g ... | 2003 | 14514042 |
| oligomerization of type iii secretion proteins popb and popd precedes pore formation in pseudomonas. | pseudomonas aeruginosa is the agent of opportunistic infections in immunocompromised individuals and chronic respiratory illnesses in cystic fibrosis patients. pseudomonas aeruginosa utilizes a type iii secretion system for injection of toxins into the host cell cytoplasm through a channel on the target membrane (the 'translocon'). here, we have functionally and structurally characterized popb and popd, membrane proteins implicated in the formation of the p.aeruginosa translocon. popb and popd f ... | 2003 | 14517235 |
| degradation of alkanes and highly chlorinated benzenes, and production of biosurfactants, by a psychrophilic rhodococcus sp. and genetic characterization of its chlorobenzene dioxygenase. | rhodococcus sp. strain ms11 was isolated from a mixed culture. it displays a diverse range of metabolic capabilities. during growth on 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene (1,2,4,5-tecb) and 3-chlorobenzoate stoichiometric amounts of chloride were released. it also utilized all three isomeric dichlorobenzenes and 1,2,3-trichlorobenzene as the sole carbon and energy source. furthermore, the bacterium grew well on a great number of n-alkanes ranging from n-heptane to n-triacontane an ... | 2003 | 14523120 |
| metabolic engineering of pentose phosphate pathway in ralstoniaeutropha for enhanced biosynthesis of poly-beta-hydroxybutyrate. | poly-beta-hydroxybutyrate (phb) biosynthesis in ralstonia eutropha from gluconate as a carbon source is carried out through the entner-doudoroff (ed) pathway and the pentose-phosphate (pp) pathway generating nadph and glyceraldehyde-3-phosphate that flows to acetyl-coa, actively in the unbalanced phb accumulation phase. the gnd gene encoding 6-phosphogluconate dehydrogenase (6pgdh) and the tkta gene encoding the transketolase (tk) in pp pathway of e. coli were transformed into r. eutropha h16 to ... | 2003 | 14524705 |
| supercritical fluid disruption of ralstonia eutropha for poly(beta-hydroxybutyrate) recovery. | a new method for disruption of gram-negative bacterium ralstonia eutropha by supercritical co(2) for poly(beta-hydroxybutyrate) (phb) recovery is proposed. the effects of different parameters such as exposure time, pressure, temperature, volume of methanol as a modifier, and culture history on cell disruption efficiency were investigated using taguchi's statistical approach to determine optimum conditions. the optimum conditions for cell disruption and phb recovery were as follows: exposure time ... | 2003 | 14524714 |
| utilization of acyl-homoserine lactone quorum signals for growth by a soil pseudomonad and pseudomonas aeruginosa pao1. | acyl-homoserine lactones (ahls) are employed by several proteobacteria as quorum-sensing signals. past studies have established that these compounds are subject to biochemical decay and can be used as growth nutrients. here we describe the isolation of a soil bacterium, pseudomonas strain pai-a, that degrades 3-oxododecanoyl-homoserine lactone (3oc12hsl) and other long-acyl, but not short-acyl, ahls as sole energy sources for growth. the small-subunit rrna gene from strain pai-a was 98.4% identi ... | 2003 | 14532048 |
| use of 16s rrna gene sequencing for rapid identification and differentiation of burkholderia pseudomallei and b. mallei. | burkholderia pseudomallei and b. mallei, the causative agents of melioidosis and glanders, respectively, are designated category b biothreat agents. current methods for identifying these organisms rely on their phenotypic characteristics and an extensive set of biochemical reactions. we evaluated the use of 16s rrna gene sequencing to rapidly identify these two species and differentiate them from each other as well as from closely related species and genera such as pandoraea spp., ralstonia spp. ... | 2003 | 14532197 |
| two phenotypically compensating isocitrate dehydrogenases in ralstonia eutropha. | the tricarboxylic acid (tca) cycle enzyme isocitrate dehydrogenase (idh) and the glyoxylate bypass enzyme isocitrate lyase are involved in catabolism of isocitrate and play a key role in controlling the metabolic flux between the tca cycle and the glyoxylate shunt. two idh genes icd1 and icd2 of ralstonia eutropha hf39, encoding isocitrate dehydrogenase 1 (idh1) and isocitrate dehydrogenase 2 (idh2), were identified and characterized. icd1 was functionally expressed in escherichia coli, whereas ... | 2003 | 14568142 |
| direct detection of a hydrogen ligand in the [nife] center of the regulatory h2-sensing hydrogenase from ralstonia eutropha in its reduced state by hyscore and endor spectroscopy. | the regulatory h2-sensing [nife] hydrogenase of the beta-proteobacterium ralstonia eutropha displays an ni-c "active" state after reduction with h2 that is very similar to the reduced ni-c state of standard [nife] hydrogenases. pulse electron nuclear double resonance (endor) and four-pulse eseem (hyperfine sublevel correlation, hyscore) spectroscopy are applied to obtain structural information on this state via detection of the electron-nuclear hyperfine coupling constants. two proton hyperfine ... | 2003 | 14570480 |
| characterization of the hrp pathogenicity cluster of erwinia carotovora subsp. carotovora: high basal level expression in a mutant is associated with reduced virulence. | extracellularly targeted proteins are crucial for virulence of gram-negative phytopathogenic bacteria. erwinia carotovora subsp. carotovora employs the so-called type ii (gsp) pathway to secrete a number of pectinases and cellulases, which cause the typical tissue maceration symptoms of soft-rot disease. the type iii (hrp) pathway is the major virulence determinant in the genera pseudomonas, ralstonia and xanthomonas, and in non-macerating species of erwinia. the hrp cluster was recently partial ... | 2003 | 14576934 |
| aerobic tryptophan degradation pathway in bacteria: novel kynurenine formamidase. | while a variety of chemical transformations related to the aerobic degradation of l-tryptophan (kynurenine pathway), and most of the genes and corresponding enzymes involved therein have been predominantly characterized in eukaryotes, relatively little was known about this pathway in bacteria. using genome comparative analysis techniques we have predicted the existence of the three-step pathway of aerobic l-tryptophan degradation to anthranilate (anthranilate pathway) in several bacteria. based ... | 2003 | 14592712 |
| microbial diversity and prevalence of virulent pathogens in biofilms developed in a water reclamation system. | bacterial biofilm is a common phenomenon in both natural and engineered systems which often becomes a source of contamination and microbially influenced corrosion. it is thought that formation of biofilm in the monoculture of several bacterial species is regulated by acylhomoserine lactone (ahl) quorum-sensing signals. in this study, we investigated the microbial diversity and existence of ahl-producing and ahl-degrading bacterial species in the biofilm samples from a water reclamation system lo ... | 2003 | 14596899 |
| chemical modification of catalytically essential functional groups of nad-dependent hydrogenase from ralstonia eutropha h16. | amino acid residues his and cys of the nad-dependent hydrogenase from the hydrogen-oxidizing bacterium ralstonia eutropha h16 were chemically modified with specific reagents. the modification of his residues of the nonactivated hydrogenase resulted in decrease in both hydrogenase and diaphorase activities of the enzyme. activation of nadh hydrogenase under anaerobic conditions led to the modification of additional his residue (or residues) significant only for the hydrogenase activity. the rate ... | 2003 | 14606942 |
| use of 3-hydroxyphenylacetylene for activity-dependent, fluorescent labeling of bacteria that degrade toluene via 3-methylcatechol. | 3-hydroxyphenylacetylene (3-hpa) served as a novel, activity-dependent, fluorogenic and chromogenic probe for bacterial enzymes known to degrade toluene via meta ring fission of the intermediate, 3-methylcatechol. by this direct physiological analysis, cells grown with an aromatic substrate to induce the synthesis of toluene-degrading enzymes were fluorescently labeled. | 2003 | 14607424 |
| analysis of bacterial dna patterns--an approach for controlling biotechnological processes. | optimisation of biotechnological processes catalysed by microbial cells requires detailed information about operational limits of the single cells. their performance is correlated with distinct physiological states. we related these states to cell cycle events, which were found to proceed extremely diversely in different bacterial strains. characteristic dna patterns were found flow cytometrically, depending on the type of strain, substrates and growth conditions involved; this information can b ... | 2003 | 14607431 |
| the glyoxylate bypass of ralstonia eutropha. | the glyoxylate bypass genes acea1 (isocitrate lyase 1, icl1), acea2 (isocitrate lyase 2, icl2) and aceb1 (malate synthase, ms1) of ralstonia eutropha hf39 were cloned, sequenced and functionally expressed in escherichia coli. interposon-mutants of all three genes (deltaacea1, deltaacea2 and deltaaceb1) were constructed, and the phenotypes of the respective mutants were investigated. whereas r. eutropha hf39deltaacea1 retained only 19% of icl activity and failed to grow on acetate, r. eutropha hf ... | 2003 | 14612238 |
| erecta, an lrr receptor-like kinase protein controlling development pleiotropically affects resistance to bacterial wilt. | bacterial wilt, one of the most devastating bacterial diseases of plants worldwide, is caused by ralstonia solanacearum and affects many important crop species. we show that several strains isolated from solanaceous crops in europe are pathogenic in different accessions of arabidopsis thaliana. one of these strains, 14.25, causes wilting symptoms in a. thaliana accession landsberg erecta (ler) and no apparent symptoms in accession columbia (col-0). disease development and bacterial multiplicatio ... | 2003 | 14617092 |
| biophysical characterization of the merp-like amino-terminal extension of the mercuric reductase from ralstonia metallidurans ch34. | the purified native mercuric reductase (mera) from ralstonia metallidurans ch34 contains an n-terminal sequence of 68 amino acids predicted to be homologous to merp, the periplasmic mercury-binding protein. this merp-like protein has now been expressed independently. the protein was named meraa by homology with ccc2a, the first soluble domain of the copper-transporting atpase from yeast. deltaa has been characterized using a set of biophysical techniques. the binding of mercury was followed usin ... | 2004 | 14624351 |
| temperature optima of enzyme-catalysed reactions in microemulsion systems. | ternary phase systems (water/surfactant/organic solvent) were utilised to increase and broaden the temperature optima of enzyme-catalysed reactions. alcohol dehydrogenases from yeast and thermoanaerobium brockii (ec 1.1.1.1 and ec 1.1.1.2), lactate dehydrogenase from lactobacillus delbrueckii (ec 1.1.1.28) and the particulate hydrogenase from ralstonia eutropha (ec 1.18.99.1) were used as model enzymes in microemulsions, consisting of the surfactant aerosol ot, and various alkane solvent and aqu ... | 2004 | 14634797 |
| legume symbiotic nitrogen fixation by beta-proteobacteria is widespread in nature. | following the initial discovery of two legume-nodulating burkholderia strains (l. moulin, a. munive, b. dreyfus, and c. boivin-masson, nature 411:948-950, 2001), we identified as nitrogen-fixing legume symbionts at least 50 different strains of burkholderia caribensis and ralstonia taiwanensis, all belonging to the beta-subclass of proteobacteria, thus extending the phylogenetic diversity of the rhizobia. r. taiwanensis was found to represent 93% of the mimosa isolates in taiwan, indicating that ... | 2003 | 14645288 |
| nodulation of mimosa spp. by the beta-proteobacterium ralstonia taiwanensis. | several beta-proteobacteria have been isolated from legume root nodules and some of these are thought to be capable of nodulating and fixing n2. however, in no case has there been detailed studies confirming that they are the active symbionts. here, ralstonia taiwanensis lmg19424, which was originally isolated from mimosa pudica nodules, was transformed to carry the green fluorescent protein (gfp) reporter gene before being used to inoculate axenically-grown seedlings of m. pudica and m. diplotr ... | 2003 | 14651338 |
| non-conventional yeasts as producers of polyhydroxyalkanoates--genetic engineering of arxula adeninivorans. | the non-conventional yeast arxula adeninivorans was equipped with the genes phba, phbb and phbc of the polyhydroxyalkanoate (pha) biosynthetic pathway of ralstonia eutropha, which encode beta-ketothiolase, nadph-linked acetoacetyl-coa reductase and pha synthase, respectively. arxula strains transformed solely with the pha synthase gene (phbc) were able to produce pha. however, the maximum content of the polymer detected in these strains was just 0.003% poly-3-hydroxybutyrate (phb) and 0.112% pol ... | 2004 | 14655026 |
| efficient degradation of 2,4,6-trichlorophenol requires a set of catabolic genes related to tcp genes from ralstonia eutropha jmp134(pjp4). | 2,4,6-trichlorophenol (2,4,6-tcp) is a hazardous pollutant. several aerobic bacteria are known to degrade this compound. one of these, ralstonia eutropha jmp134(pjp4), a well-known, versatile chloroaromatic compound degrader, is able to grow in 2,4,6-tcp by converting it to 2,6-dichlorohydroquinone, 6-chlorohydroxyquinol, 2-chloromaleylacetate, maleylacetate, and beta-ketoadipate. three enzyme activities encoded by tcp genes, 2,4,6-tcp monooxygenase (tcpa), 6-chlorohydroxyquinol 1,2-dioxygenase ... | 2003 | 14660355 |
| specific and sensitive detection of ralstonia solanacearum in soil on the basis of pcr amplification of flic fragments. | ralstonia solanacearum is the causative agent of bacterial wilt in many important crops. a specific and sensitive pcr detection method that uses primers targeting the gene coding for the flagella subunit, flic, was established. based on the first flic gene sequence of r. solanacearum strain k60 available at genbank, the ral_flic pcr primer system was designed; this system yielded a single 724-bp product with the dnas of all of the r. solanacearum strains tested. however, r. pickettii and four en ... | 2003 | 14660373 |
| production of purified polyhydroxyalkanoates (phas) for applications in contact with blood. | samples of olyhydroxyalkanoates (phas), polyhydroxybutyrate (phb) and copolymers poly(hydroxybutyrate-co-hydroxyvalerate) (phbv) with 4 and 18 mol% hydroxyvalerate, synthesized by the bacteria ralstonia eutropha b5786, were investigated. pha films in contact with blood did not activate the hemostasis system at the level of cell response, but they did activate the coagulation system and the complement reaction. to detect biologically-active components in the phas, a detailed analysis of the compo ... | 2003 | 14661877 |
| a monooxygenase catalyzes sequential dechlorinations of 2,4,6-trichlorophenol by oxidative and hydrolytic reactions. | ralstonia eutropha jmp134 2,4,6-trichlorophenol (2,4,6-tcp) 4-monooxygenase catalyzes sequential dechlorinations of 2,4,6-tcp to 6-chlorohydroxyquinol. although 2,6-dichlorohydroxyquinol is a logical metabolic intermediate, the enzyme hardly uses it as a substrate, implying it may not be a true intermediate. evidence is provided to support the proposition that the monooxygenase oxidized 2,4,6-tcp to 2,6-dichloroquinone that remained with the enzyme and got hydrolyzed to 2-chlorohydroxyquinone, w ... | 2004 | 14662756 |
| dna fingerprinting of ralstonia paucula by infrequent-restriction-site pcr and randomly amplified polymorphic dna analysis. | ralstonia paucula (formerly cdc group iv c-2) is an environmental organism that can cause serious human infections, occasionally clusters of nosocomial infections. in the present work, 26 strains of r. paucula (4 from the american centers for disease control and prevention collection, 10 from the belgian laboratorium voor microbiologie [lmg] collection, and 12 french clinical isolates) were analyzed with infrequent-restriction-site pcr and randomly amplified polymorphic dna analysis. both techni ... | 2003 | 14662974 |
| effect of temperature and dissolved oxygen on the growth kinetics of pseudomonas putida f1 growing on benzene and toluene. | batch experiments were conducted to determine the effect of temperature and dissolved oxygen concentration on the rates of growth and substrate (benzene and toluene) degradation by the toluene degrading strain, pseudomonas putida f1. over a range of temperature from 15 to 35 degrees c the maximum specific growth rate followed the topiwala-sinclair relationship when either benzene or toluene served as the sole carbon and energy source. oxygen limited growth followed monod saturation kinetics with ... | 2004 | 14664855 |
| pcrh of pseudomonas aeruginosa is essential for secretion and assembly of the type iii translocon. | pseudomonas aeruginosa harbors a type iii secretion system that translocates antihost effectors into an infected eukaryotic cell. pcrh is a key component of type iii secretion in this essential virulence strategy. in the absence of pcrh, p. aeruginosa is translocation deficient because of a specific reduction in presecretory stability and subsequent secretion of popb and popd, 2 proteins essential for the translocation process. pcrh exerts this chaperone function by binding directly to popb and ... | 2003 | 14673772 |
| mutation analysis of the different tfd genes for degradation of chloroaromatic compounds in ralstonia eutropha jmp134. | ralstonia eutropha jmp134 possesses two sets of similar genes for degradation of chloroaromatic compounds, tfdcdefb (in short: tfdi cluster) and tfddii cii eii fii bii (tfdii cluster). the significance of two sets of tfd genes for the organism has long been elusive. here, each of the tfd genes in the two clusters on the original plasmid pjp4 was replaced by double recombination with a gene fragment in which a kanamycin resistance gene was inserted into the respective tfd gene's reading frame. th ... | 2004 | 14676989 |
| expression of l-ornithine ndelta-oxygenase (pvda) in fluorescent pseudomonas species: an immunochemical and in silico study. | omega-amino acid monooxygenases (ec 1.14.13.-), catalysing the formation of hydroxamate precursors of microbial siderophores (e.g., pyoverdine), have so far eluded structural and biochemical characterisation. here, the expression of recombinant l-ornithine-ndelta-oxygenase (pvda) from pseudomonas aeruginosa pao1 is reported. a library of eight monoclonal antibodies (mabs) directed against pvda has been generated. two mab families recognising the n- and c-terminal regions of pvda were identified. ... | 2004 | 14684153 |
| ralstonia pickettii outbreak associated with contaminated distilled water used for respiratory care in a paediatric intensive care unit. | | 2004 | 14706279 |
| propionyl-coenzyme a synthetases of ralstonia solanacearum and salmonella choleraesuis display atypical kinetics. | propionyl-coenzyme a synthetases (prpe) of salmonella choleraesuis and ralstonia solanacearum sharing 62% identity in amino acid sequence to each other were cloned, expressed in escherichia coli and purified. both enzymes catalyzed acetyl-, propionyl-, butyryl- and acrylyl-coenzyme a formation with the highest k(cat)/k(m) values for propionate. they displayed sigmoidal homotrophic autoactivation kinetics for propionate but not for the other acyl substrates tested. besides, substrate inhibition k ... | 2004 | 14706841 |
| prominent roles of the norr and fur regulators in the escherichia coli transcriptional response to reactive nitrogen species. | we examined the genomewide transcriptional responses of escherichia coli treated with nitrosylated glutathione or the nitric oxide (no)-generator acidified sodium nitrite (nano(2)) during aerobic growth. these assays showed that norr, a homolog of no-responsive transcription factors in ralstonia eutrophus, and fur, the global repressor of ferric ion uptake, are major regulators of the response to reactive nitrogen species. in contrast, soxr and oxyr, regulators of the e. coli defenses against su ... | 2004 | 14718666 |
| salicylate biodegradation by various algal-bacterial consortia under photosynthetic oxygenation. | four green microalgae (chlorella sorokiniana, chlorella vulgaris, scenedesmus obliquus and selenastrum capricornutum), a wild bolivian microalga strain and two cyanobacteria (anabaena catenula and microcystis aeruginosa) were compared for tolerance to salicylate, o2 production capacity and ability to support salicylate degradation by a ralstonia basilensis strain in symbiotic microcosms with the microalgae. microcystis aeruginosa had the highest tolerance to salicylate at 500 mg l(-1) and 1500 m ... | 2003 | 14719825 |
| illuminating the molecular basis of gene-for-gene resistance; arabidopsis thaliana rrs1-r and its interaction with ralstonia solanacearum popp2. | elucidation of the molecular basis of gene-for-gene interactions between disease-resistance (r) genes and pathogen avirulence (avr) genes has been a holy grail of plant pathology for the past decade. recent studies of the r-avr interaction between rrs1-r and popp2 by laurent deslandes et al. provide new insights and suggest a direct physical association of the encoded proteins in support of a simplistic receptor-ligand model. however, careful consideration of the experimental findings reveals th ... | 2004 | 14729210 |
| global analysis of the ralstonia metallidurans proteome: prelude for the large-scale study of heavy metal response. | a proteome map of ralstonia metallidurans strain ch34 was constructed using two-dimensional (2-d) gel electrophoresis in combination with automated edman degradation and mass spectrometry (ms). r. metallidurans ch34 is the type-strain of a family of highly related strains characterized by their multiple resistance to millimolar amounts of heavy metals, conferred by two large plasmids. the protein content of this bacterium grown in minimal medium was separated by 2-d gel electrophoresis using var ... | 2004 | 14730679 |
| heterologous production and characterization of bacterial nickel/cobalt permeases. | nickel/cobalt permeases (nicots, tc 2.a.52) are a rapidly growing family of structurally related membrane transporters whose members are found in gram-negative and gram-positive bacteria, in thermoacidophilic archaea, and in fungi. previous studies have predicted two subclasses represented by hoxn of ralstonia eutropha, a selective nickel transporter, and by nhlf of rhodococcus rhodochrous, a nickel and cobalt transporter that displays a preference for the co ion. in the present study, nicot gen ... | 2004 | 14734175 |
| effects of srt and do on n2o reductase activity in an anoxic-oxic activated sludge system. | nitrous oxide (n2o) is emitted from wastewater treatment processes, and is known to be a green house gas contributing to global warming. it is thus important to develop technology that can suppress n2o emission. the effects of sludge retention time (srt) and dissolved oxygen (do) on n2o emission in an anoxic-oxic activated sludge system were estimated. moreover, the microbial community structure in the sludge, which plays an important role in n2o suppression, was clarified based on nitrous oxide ... | 2003 | 14753557 |
| the activator of the rhodospirillum rubrum phb depolymerase is a polypeptide that is extremely resistant to high temperature (121 degrees c) and other physical or chemical stresses. | hydrolysis of native (amorphous) polyhydroxybutyrate (nphb) granules isolated from different sources by soluble phb depolymerase of rhodospirillum rubrum in vitro requires the presence of a heat-stable compound (activator). the activator was purified and was resistant against various physical and chemical stresses such as heat (up to 130 degrees c), ph 1-12, dryness, oxidation by h2o2, reducing and denaturing compounds (2-mercaptoethanol, 5 m guanidinium-hcl) and many solvents including phenol/c ... | 2004 | 14757249 |
| polyhydroxyalkanoate (pha) granule formation in ralstonia eutropha cells: a computer simulation. | computer simulation of polyhydroxyalkanoate (pha) granule formation in vivo could help to design strategies to optimize the fermentation process and achieve higher yields of pha. it could also suggest biotechnological approaches to control the granule size and molecular weight of the polymer. a computer program simulating the formation of pha granules inside a ralstonia eutropha cell was developed, based on published experimental data. the results are applicable to r. eutropha cells or other mic ... | 2004 | 14758517 |
| sequential feeding of glucose and valerate in a fed-batch culture of ralstonia eutropha for production of poly(hydroxybutyrate-co-hydroxyvalerate) with high 3-hydroxyvalerate fraction. | several important properties of poly(3-hydroxybutyric-co-3-hydroxyvaleric acids) (p(3hb-co-3hv) depend mainly on the hv unit fraction of the copolymer. sequential and simultaneous feeding of glucose and valerate were employed to produce p(3hb-co-3hv) in a fed-batch culture of ralstonia eutropha, and the effects of feeding models on the cell growth, 3hv unit fraction, and copolymer productivity have been investigated. the sequential feeding of glucose and then valerate resulted in a cell density ... | 2004 | 14763836 |
| selective release and function of one of the two fmn groups in the cytoplasmic nad+-reducing [nife]-hydrogenase from ralstonia eutropha. | the soluble, cytoplasmic nad+-reducing [nife]-hydrogenase from ralstonia eutropha is a heterotetrameric enzyme (hoxfuyh) and contains two fmn groups. the purified oxidized enzyme is inactive in the h2-nad+ reaction, but can be activated by catalytic amounts of nadh. it was discovered that one of the fmn groups (fmn-a) is selectively released upon prolonged reduction of the enzyme with nadh. during this process, the enzyme maintained its tetrameric form, with one fmn group (fmn-b) firmly bound, b ... | 2004 | 14764097 |
| characterization of a gene cluster encoding the maleylacetate reductase from ralstonia eutropha 335t, an enzyme recruited for growth with 4-fluorobenzoate. | a gene cluster containing a gene for maleylacetate reductase (ec 1.3.1.32) was cloned from ralstonia eutropha 335(t) (dsm 531(t)), which is able to utilize 4-fluorobenzoate as sole carbon source. sequencing of this gene cluster showed that the r. eutropha 335(t) maleylacetate reductase gene, maca, is part of a novel gene cluster, which is not related to the known maleylacetate-reductase-encoding gene clusters. it otherwise comprises a gene for a hypothetical membrane transport protein, macb, pos ... | 2004 | 14766925 |
| outbreak of infusion-related septicemia by ralstonia pickettii in the oncology department. | hospital acquired blood stream infection by ralstonia pickettii in 9 cancer patients related to the heparin solution contamination used to flush the central venous catheter. | 2003 | 14870792 |
| antifungal activity of beta-asarone from rhizomes of acorus gramineus. | an antifungal substance was isolated from the extract of acorus gramineus using various chromatographic procedures. the antibiotic was identified as beta-asarone, cis-2,4,5-trimethoxy-1-propenylbenzene, on the basis of the high-resolution ei-mass, nmr, and uv spectral data. beta-asarone completely inhibited mycelial growth of some plant pathogenic fungi, cladosporium cucumerinum,colletotrichum orbiculare, magnaporthe grisea, and pythium ultimum, in a range of 0.5-30 microg/ml. the growth of baci ... | 2004 | 14969530 |
| trichloroethylene degradation by toluene-oxidizing bacteria grown on non-aromatic substrates. | the potential of trichloroethylene (tce) to induce and non-aromatic growth substrates to support tce degradation in five strains (pseudomonas mendocina kr1, ralstonia pickettii pko1, pseudomonas putida f1, burkholderia cepacia g4, b. cepacia pr1) of toluene-oxidizing bacteria was examined. lb broth and acetate did not support tce degradation in any of the wild-type strains. in contrast, fructose supported the highest specific levels of tce oxidation observed in each of the strains tested, except ... | 2004 | 14971854 |
| the h2-sensing complex of ralstonia eutropha: interaction between a regulatory [nife] hydrogenase and a histidine protein kinase. | two [nife] hydrogenases enable the proteobacterium ralstonia eutropha h16 to grow on molecular hydrogen as the sole energy source. a third [nife] hydrogenase (rh) acts as an h2 sensor in a multiple component signal transduction chain that controls hydrogenase gene transcription. the rh forms a dimeric heterodimer (hoxbc)2 in which hoxc contains the h2-sensing active site and hoxb the electron-transferring components including an organic, not yet identified redox cofactor. this oligomer forms a t ... | 2004 | 15009894 |
| incidence and function of sigma factors in ralstonia metallidurans and other bacteria. | bacterial sigma factors are essential for directing the bacterial rna polymerase to promoter regions during transcription initiation. genomic sequencing of the highly heavy-metal-resistant beta-proteobacterium ralstonia metallidurans strain ch34 revealed 17 candidate genes for sigma factors. this review compares the sigma factor machinery of r. metallidurans to that of other bacteria. the sigma factors of 105 bacterial genomes were assigned to sigma factor clusters and families formed around the ... | 2004 | 15022036 |
| wautersia gen. nov., a novel genus accommodating the phylogenetic lineage including ralstonia eutropha and related species, and proposal of ralstonia [pseudomonas] syzygii (roberts et al. 1990) comb. nov. | comparative 16s rdna sequence analysis indicates that two distinct sublineages, with a sequence dissimilarity of >4 % (bootstrap value, 100 %), exist within the genus ralstonia: the ralstonia eutropha lineage, which comprises ralstonia basilensis, ralstonia campinensis, r. eutropha, ralstonia gilardii, ralstonia metallidurans, ralstonia oxalatica, ralstonia paucula, ralstonia respiraculi and ralstonia taiwanensis; and the ralstonia pickettii lineage, which comprises ralstonia insidiosa, ralstoni ... | 2004 | 15023939 |
| reliable, sensitive, rapid and quantitative enzyme-based assay for gamma-hydroxybutyric acid (ghb). | several assays for gamma-hydroxybutyrate (4-hydroxybutyrate, ghb) have been developed based on the enzyme gamma-hydroxybutyrate dehydrogenase (ghb-dh). enzymatic oxidation of ghb by nad+ is coupled to diaphorase-mediated reduction of pro-dye to yield colored product. ghb-dh from ralstonia eutropha was cloned and expressed as a stable fusion protein easily purified by affinity chromatography. quantitative initial velocity and endpoint versions of the assay in solution are described. michaelis-men ... | 2004 | 15027565 |