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influence of substrate exposure history on biodegradation in a porous medium.this study investigates the influence of fluctuating toluene concentrations on aerobic toluene degradation in a sandy porous medium colonized with ralstonia pickettii pko1. column effluent toluene concentrations were found to increase after a temporary decrease in influent toluene concentration. subsequent examination of the spatial gradient of toluene degradative activity in the column suggested that the observed increase in effluent toluene concentrations was attributable to an adverse effect ...200111588828
ralstonia taiwanensis sp. nov., isolated from root nodules of mimosa species and sputum of a cystic fibrosis patient.a polyphasic taxonomic study, including 16s rdna sequence analysis, dna-dna hybridizations, dna base ratio determinations, amplified 165 rdna restriction analysis, whole-cell protein analyses and extensive biochemical characterization, was conducted to clarify the relationships of eight isolates from root nodules of mimosa species and one isolate from sputum of a cystic fibrosis patient. all nine isolates were classified as a novel ralstonia species, for which the name ralstonia taiwanensis sp. ...200111594603
detection and activity of insertion sequences in environmental strains of burkholderia.the presence of two insertion sequences, is406 and is407, was tested by polymerase chain reaction (pcr) amplification in 25 strains representing 15 burkholderia species and the close relative ralstonia pickettii. a total of 50% of the 25 strains contained at least one of the two insertion sequences (iss) and a statistically significant correlation was found between the occurrences of is406 and is407. moreover, pcr-rflp studies of the amplified fragments showed that is406 is largely conserved amo ...200111846770
strain characterization and 16s-23s probe development for differentiating geographically dispersed isolates of the phytopathogen ralstonia solanacearum.the causative agent of potato brown rot and bacterial wilt, ralstonia solanacearum, results in serious world-wide economic losses, particularly in the tropics. in the last decade, however, the incidence of bacterial wilt in potatoes grown in northern europe has increased, presenting an interesting epidemiological puzzle. its occurrence may be as a result of changes in agricultural practice or the emergence of a novel bacterial variety, better adapted to cooler conditions. to understand the distr ...200111846772
classification of metal-resistant bacteria from industrial biotopes as ralstonia campinensis sp. nov., ralstonia metallidurans sp. nov. and ralstonia basilensis steinle et al. 1998 emend.thirty-one heavy-metal-resistant bacteria isolated from industrial biotopes were subjected to polyphasic characterization, including 16s rdna sequence analysis, dna-dna hybridizations, biochemical tests, whole-cell protein and fatty-acid analyses. all strains were shown to belong to the ralstonia branch of the beta-proteobacteria. whole-cell protein profiles and dna-dna hybridizations revealed two clearly distinct groups, showing low similarity to known ralstonia species. these two groups, of 8 ...200111594608
production of catechol from benzoate by the wild strain ralstonia species ba-0323 and characterization of its catechol 1,2-dioxygenase.ralstonia sp. ba-0323, a wild strain isolated from soil, produced catechol from benzoate and accumulated it outside the cells. the bacterium produced a maximal amount of catechol (1.6 mg/ml) from 3 mg/ml of sodium benzoate in a 20-h growing culture. the conversion rate of benzoate to catechol was 70% on a molar basis. the catechol production by the resting cells increased in the presence of glycerol, and the maximal amount of catechol produced from 3 mg/ml of sodium benzoate reached 1.9 mg/ml at ...200111676005
biomonitoring of pjp4-carrying pseudomonas chlororaphis with trb protein-specific antisera.the transfer of catabolic genes on conjugative plasmids to indigenous organisms from which they may spread further into the community allows the introduction of new biodegradative pathways for metabolic conversion of pollutants to the community. biomonitoring of incp plasmid pjp4-carrying pseudomonas chlororaphis from the rhizosphere of arabidopsis thaliana was achieved using antisera specific for proteins from the plasmid transfer machinery. antisera were generated that recognized trbc and trbf ...200111846762
analysis of mutational effects of a polyhydroxybutyrate (phb) polymerase on bacterial phb accumulation using an in vivo assay system.polymerase is a central enzyme involved in the biosynthesis of polyhydroxybutyrate (phb), a well-known bacterial biodegradable polyester. in this study, we have established an in vivo assay system to analyze mutational effects of ralstonia eutropha polymerase (termed phbc(re)) on the level of phb accumulation in recombinant strains of escherichia coli. this in vitro evolution system consists of a polymerase chain reaction-mediated random mutagenesis and two assay procedures, a plate assay using ...200111325555
heterologous expression of the acyl-acyl carrier protein thioesterase gene from the plant umbellularia californica mediates polyhydroxyalkanoate biosynthesis in recombinant escherichia coli.the acyl-acyl carrier protein (acp) thioesterase cdna from the plant umbellularia californica was functionally expressed in various recombinant escherichia coli strains in order to establish a new metabolic route toward medium-chain-length polyhydroxyalkanoate (pha(mcl)) biosynthesis from non-related carbon sources. coexpression of the pha synthase genes from ralstonia eutropha and pseudomonas aeruginosa, or only the pha synthase gene from p. aeruginosa, respectively, showed pha(mcl) accumulatio ...200111330715
a calorimetrically based method to convert toxic compounds into poly-3-hydroxybutyrate and to determine the efficiency and velocity of conversion.a fed-batch method for converting toxic substrates into poly-3-hydroxybutyrate is presented. the method involves a series of batch-growth processes, regulated by adding small amounts of carbon substrate, during the course of which the concentration of the nitrogen source decreases and controls the distribution of the substrate-carbon assimilated. the addition of carbon substrate is controlled, and the small changes that occur in the growth pattern are interpreted using high-resolution reaction c ...200111330720
metabolic flux modeling of detoxification of acetic acid by ralstonia eutropha at slightly alkaline ph levels.ralstonia eutropha grows on and produces polyhydroxyalkanoates (phas) from fermentation acids. acetic acid, one major organic acid from acidogenesis of organic wastes, has an inhibitory effect on the bacterium at slightly alkaline ph (6 g hac/l at ph 8). the tolerance of r. eutropha to acetate, however, was increased significantly up to 15 g/l at the slightly alkaline ph level with high cell mass concentration. a metabolic cell model with five fluxes is proposed to depict the detoxification mech ...200111344450
an aerobic fixed-phase biofilm reactor system for the degradation of the low-molecular weight aromatic compounds occurring in the effluents of anaerobic digestors treating olive mill wastewaters.an aerobic co-culture, prepared by combining ralstonia sp. ld35 and pseudomonas putida dsm1868, was recently found to be capable of extensively degrading many of the hydroxylated and/or methoxylated benzoic, phenylacetic and 3-phenyl-2-propenoic acids occurring in the olive mill wastewaters (omws). in the perspective of developing a biotechnological process for the degradation of low-molecular weight (mw) aromatic compounds occurring in the effluents of anaerobic digestors treating omws, the cap ...200111278039
the h2 sensor of ralstonia eutropha. biochemical characteristics, spectroscopic properties, and its interaction with a histidine protein kinase.previous genetic studies have revealed a multicomponent signal transduction chain, consisting of an h(2) sensor, a histidine protein kinase, and a response regulator, which controls hydrogenase gene transcription in the proteobacterium ralstonia eutropha. in this study, we isolated the h(2) sensor and demonstrated that the purified protein forms a complex with the histidine protein kinase. biochemical and spectroscopic analysis revealed that the h(2) sensor is a cytoplasmic [nife]-hydrogenase wi ...200111278570
biodegradation of hydroxylated and methoxylated benzoic, phenylacetic and phenylpropenoic acids present in olive mill wastewaters by two bacterial strains.two aerobic bacterial strains, a chlorophenol-degrading bacterium characterized in this work as a ralstonia sp. ld35 on the basis of the sequence of the gene encoding for 16s ribosomal rna, and pseudomonas putida dsm 1868, capable of metabolizing 4-methoxybenzoic acid, were tested for their capacity to degrade monocyclic aromatic acids responsible for the toxicity of olive mill wastewaters (omws). both strains possess interesting and complementary degradation capabilities in resting cell conditi ...200111281329
cloning and expression of a ralstonia eutropha hf39 gene mediating indigo formation in escherichia coli.on complex medium escherichia coli strains carrying hybrid plasmid pbec/ee:11.0, pskbec/be:9.0, pskbec/pp:3.3, or pskbec/pp:2.4 harboring genomic dna of ralstonia eutropha hf39 produced a blue pigment characterized as indigo by several chemical and spectroscopic methods. a 1,251-bp open reading frame (bec) was cloned and sequenced. the deduced amino acid sequence of bec showed only weak similarities to short-chain acyl-coenzyme a dehydrogenases, and the gene product catalyzed formation of indoxy ...200111282658
nickel-resistance-based minitransposons: new tools for genetic manipulation of environmental bacteria.the ncc and nre nickel resistance determinants from ralstonia eutropha-like strain 31a were used to construct mini-tn5 transposons. broad host expression of nickel resistance was observed for the nre minitransposons in members of the alpha, beta, and gamma subclasses of the proteobacteria, while the ncc minitransposons expressed nickel resistance only in r. eutropha-like strains.200111157282
sera from adult patients with cystic fibrosis contain antibodies to pseudomonas aeruginosa type iii apparatus.expression of type iii proteins of pseudomonas aeruginosa in patients with cystic fibrosis (cf) was investigated by measuring the immune response against components of the type iii pathway. twenty-three of the 33 sera contained antibodies against pcrv, a protein involved in translocation of type iii cytotoxins into eukaryotic cells, and 11 of 33 had antibodies against exos, while most cf sera contained antibodies against popb and popd, components of the type iii apparatus. these data indicate th ...200111160019
identification of a new class of biopolymer: bacterial synthesis of a sulfur-containing polymer with thioester linkages.this is the first report on the biosynthesis of a hitherto unknown, sulfur-containing polyester and also the first report on a bacterial polymer containing sulfur in the backbone. the gram-negative polyhydroxyalkanoate (pha)-accumulating bacterium ralstonia eutropha synthesized a copolymer of 3-hydroxybutyrate and 3-mercaptopropionate, poly(3hb-co-3mp), when 3-mercaptopropionic acid or 3,3'-thiodipropionic acid was provided as carbon source in addition to fructose or gluconic acid under nitrogen ...200111160796
occurrence of tn4371-related mobile elements and sequences in (chloro)biphenyl-degrading bacteria.tn4371, a 55-kb transposable element involved in the degradation and biphenyl or 4-chlorobiphenyl identified in ralstonia eutropha a5, displays a modular structure including a phage-like integrase gene (int), a pseudomonas-like (chloro)biphenyl catabolic gene cluster (bph), and rp4- and ti-plasmid-like transfer genes (trb) (c. merlin, d. springael, and a. toussaint, plasmid 41:40-54, 1999). southern blot hybridization was used to examine the presence of different regions of tn4371 in a collectio ...200111133426
nag genes of ralstonia (formerly pseudomonas) sp. strain u2 encoding enzymes for gentisate catabolism.ralstonia sp. strain u2 metabolizes naphthalene via gentisate to central metabolites. we have cloned and sequenced a 21.6-kb region spanning the nag genes. upstream of the pathway genes are nagy, homologous to chemotaxis proteins, and nagr, a regulatory gene of the lysr family. divergently transcribed from nagr are the genes for conversion of naphthalene to gentisate (nagaaghabacadbfcqed) (s. l. fuenmayor, m. wild, a. l. boyes, and p. a. williams, j. bacteriol. 180:2522-2530, 1998), which except ...200111133965
ralstonia paucula (formerly cdc group iv c-2): unsuccessful strain differentiation with pcr-based methods, study of the 16s-23s spacer of the rrna operon, and comparison with other ralstonia species (r. eutropha, r. pickettii, r. gilardii, and r. solanacearum).ralstonia paucula (formerly cdc group iv c-2) can cause serious human infections. confronted in 1995 with five cases of nosocomial bacteremia, we found that pulsed-field gel electrophoresis could not distinguish between the isolates and that randomly amplified polymorphic dna analysis was poorly discriminatory. in this study, we used pcr-ribotyping and pcr-restriction fragment length polymorphism analysis of the spacer 16s-23s ribosomal dna (rdna); both methods were unable to differentiate r. pa ...200111136807
cloning of an intracellular poly[d(-)-3-hydroxybutyrate] depolymerase gene from ralstonia eutropha h16 and characterization of the gene product.an intracellular poly[d(-)-3-hydroxybutyrate] (phb) depolymerase gene (phaz) has been cloned from ralstonia eutropha h16 by the shotgun method, sequenced, and characterized. nucleotide sequence analysis of a 2.3-kbp dna fragment revealed an open reading frame of 1,260 bp, encoding a protein of 419 amino acids with a predicted molecular mass of 47,316 da. the crude extract of escherichia coli containing the phb depolymerase gene digested artificial amorphous phb granules and released mainly oligo ...200111114905
new insight into the role of the phap phasin of ralstonia eutropha in promoting synthesis of polyhydroxybutyrate.phasins are proteins that are proposed to play important roles in polyhydroxyalkanoate synthesis and granule formation. here the phasin phap of ralstonia eutropha has been analyzed with regard to its role in the synthesis of polyhydroxybutyrate (phb). purified recombinant phap, antibodies against phap, and an r. eutropha phap deletion strain have been generated for this analysis. studies with the phap deletion strain show that phap must accumulate to high levels in order to play its normal role ...200111244085
transformation of chlorinated benzenes and toluenes by ralstonia sp. strain ps12 teca (tetrachlorobenzene dioxygenase) and tecb (chlorobenzene dihydrodiol dehydrogenase) gene products.the tecb gene, located downstream of teca and encoding tetrachlorobenzene dioxygenase, in ralstonia sp. strain ps12 was cloned into escherichia coli dh5alpha together with the teca gene. the identity of the tecb gene product as a chlorobenzene dihydrodiol dehydrogenase was verified by transformation into the respective catechols of chlorobenzene, the three isomeric dichlorobenzenes, as well as 1,2,3- and 1,2,4-trichlorobenzenes, all of which are transformed by teca into the respective dihydrodih ...200111526005
identification of strains of alcaligenes and agrobacterium by a polyphasic approach.the number of stable discriminant biochemical characters is limited in the genera alcaligenes and agrobacterium, whose species are consequently difficult to distinguish from one another by conventional tests. moreover, genomic studies have recently drastically modified the nomenclature of these genera; for example, alcaligenes xylosoxidans was transferred to the genus achromobacter in 1998. twenty-five strains of achromobacter xylosoxidans, three strains of an agrobacterium sp., five strains of ...200111526136
phylogenetic analysis of the succession of bacterial communities in the great south bay (long island).bacterial community composition and succession were examined over the course of the summer season in the great south bay, long island, ny, usa, using a 16s rdna clone library approach. there was a progression of changes in dominant species in the libraries during the summer of 1997. the july library had several groups dominant, the sar407 relatives of the alpha-proteobacteria (24%) and the sar86 (18%), sulfur-oxidizing symbiont relatives (8%) of the gamma-proteobacteria, and unidentified cytopha ...200111248393
development of a process for the biotechnological large-scale production of 4-hydroxyvalerate-containing polyesters and characterization of their physical and mechanical properties.a process for the large-scale production of 4-hydroxyvalerate (4hv)-containing biopolyesters with a new monomer composition was developed by means of high-cell-density cultivation applying recombinant strains of pseudomonas putida and ralstonia eutropha, harboring the pha-biosynthesis genes phac and phae of thiocapsa pfennigii. cell densities of about 20 g/l revealing a pha content of 52% (w/w) and a molar fraction of 4hv of up to 15.4 mol % were obtained by a two-stage fed-batch cultivation pro ...200111749154
production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) by metabolically engineered escherichia coli strains.recombinant escherichia coli strains harboring a plasmid containing a novel artificial polyhydroxyalkanoate (pha) operon consisting of the aeromonas pha biosynthesis related genes and ralstonia eutropha reductase gene were developed for the production of poly(3-hydroxybutyrate-co-hydroxyhexanoate) [p(3hb-co-3hhx)] from dodecanoic acid. by applying stepwise reduction of dissolved oxygen concentration (doc) during the fermentation, the final dry cell weight, pha concentration, and pha content of 7 ...200111749180
isolation of an insertion sequence from ralstonia solanacearum race 1 and its potential use for strain characterization and detection.a new insertion sequence (is), is1405, was isolated and characterized from a ralstonia solanacearum race 1 strain by the method of insertional inactivation of the sacb gene. sequence analysis indicated that the is is closely related to the members of is5 family, but the extent of nucleotide sequence identity in 5' and 3' noncoding regions between is1405 and other members of is5 family is only 23 to 31%. nucleotide sequences of these regions were used to design specific oligonucleotide primers fo ...200111525989
cloning and functional analysis of the pbr lead resistance determinant of ralstonia metallidurans ch34.the lead resistance operon, pbr, of ralstonia metallidurans (formerly alcaligenes eutrophus) strain ch34 is unique, as it combines functions involved in uptake, efflux, and accumulation of pb(ii). the pbr lead resistance locus contains the following structural resistance genes: (i) pbrt, which encodes a pb(ii) uptake protein; (ii) pbra, which encodes a p-type pb(ii) efflux atpase; (iii) pbrb, which encodes a predicted integral membrane protein of unknown function; and (iv) pbrc, which encodes a ...200111544228
involvement of hyp gene products in maturation of the h(2)-sensing [nife] hydrogenase of ralstonia eutropha.the biosynthesis of [nife] hydrogenases is a complex process that requires the function of the hyp proteins hypa, hypb, hypc, hypd, hype, hypf, and hypx for assembly of the h(2)-activating [nife] site. in this study we examined the maturation of the regulatory hydrogenase (rh) of ralstonia eutropha. the rh is a h(2)-sensing [nife] hydrogenase and is required as a constituent of a signal transduction chain for the expression of two energy-linked [nife] hydrogenases. here we demonstrate that the r ...200111717266
nad(p)-dependent aldehyde dehydrogenases induced during growth of ralstonia eutropha strain bo on tetrahydrofurfuryl alcohol.different aldehyde dehydrogenases (aldhs) were formed during growth of ralstonia eutropha bo on tetrahydrofurfuryl alcohol (thfa). one of these enzymes, aldh 4, was purified and characterized as a homodimer containing no prosthetic groups, showing a strong substrate inhibition, and having an n-terminal sequence similar to those of various nad(p)-dependent aldhs. the conversion rate of thfa by the quinohemoprotein thfa dehydrogenase was increased by aldh 4.200111717302
identification of pandoraea species by 16s ribosomal dna-based pcr assays.the recently described genus pandoraea contains five named species (pandoraea apista, pandoraea pulmonicola, pandoraea pnomenusa, pandoraea sputorum, and pandoraea norimbergensis) and four unnamed genomospecies. pandoraea spp. have mainly been recovered from the respiratory tracts of cystic fibrosis (cf) patients. accurate genus- and species-level identification by routine clinical microbiology methods is difficult, and differentiation from burkholderia cepacia complex organisms may be especiall ...200111724860
comparative study of the relationship between monomer structure and reactivity for two polyhydroxyalkanoate synthases.using organically synthesized hydroxyalkanoate coenzyme a thioesters, the activities of two short-chain polyhydroxalkanoate (pha) synthases were investigated--ralstonia eutropha pha synthase (a type i pha synthase) and ectothiorhodospira shaposhnikovii pha synthase (a type iii synthase). the results indicate that the two synthases have similar activities towards most of the monomers tested. 3-hydroxybutyryl coa was found to be the most efficient substrate for both synthases. changes in the side- ...200111499920
one case each of recurrent meningitis and hemoperitoneum infection with ralstonia mannitolilytica.two clinical cases of infection with ralstonia mannitolilytica are described: a recurrent meningitis on an implanted intraventricular catheter and an infected hemoperitoneum as a complication of a cholangiocarcinoma. the strains were first misidentified as pseudomonas fluorescens and burkholderia cepacia. further testing lead to the identification as ralstonia pickettii biovar 3/"thomasii," which was recently shown to represent a separate species, r. mannitolilytica (list editor n. weiss, int. j ...200111724893
quorum-sensing in gram-negative bacteria.it has become increasingly and widely recognised that bacteria do not exist as solitary cells, but are colonial organisms that exploit elaborate systems of intercellular communication to facilitate their adaptation to changing environmental conditions. the languages by which bacteria communicate take the form of chemical signals, excreted from the cells, which can elicit profound physiological changes. many types of signalling molecules, which regulate diverse phenotypes across distant genera, h ...200111524130
the viable but nonculturable state of ralstonia solanacearum may be involved in long-term survival and plant infection.the role of the dormant-like viable but nonculturable (vbnc) condition in the etiology of bacterial infection was examined using a plant system. the plant-pathogenic bacterium ralstonia solanacearum was first shown to enter into the vbnc state both in response to cupric sulfate when in a saline solution and when placed in autoclaved soil. to determine if the vbnc condition is related to pathogenesis, the physiological status of bacteria recovered from different regions of inoculated tomato plant ...200111525979
twitching motility of ralstonia solanacearum requires a type iv pilus system.twitching motility is a form of bacterial translocation over firm surfaces that requires retractile type iv pili. microscopic colonies of ralstonia solanacearum strains aw1, k60 and gmi1000 growing on the surface of a rich medium solidified with 1.6% agar appeared to exhibit twitching motility, because early on they divided into motile 'rafts' of cells and later developed protruding 'spearheads' at their margins. individual motile bacteria were observed only when they were embedded within masses ...200111739754
polyhydroxybutyrate biosynthesis in caulobacter crescentus: molecular characterization of the polyhydroxybutyrate synthase.caulobacter crescentus was investigated with respect to polyhydroxybutyrate (phb) biosynthesis. polyhydroxyalkanoate (pha) accumulation contributing to approximately 18% of the cell dry weight was obtained in the presence of glucose. gas chromatography-mass spectrometry and gel permeation chromatography of the purified pha showed that this polyester was solely composed of 3-hydroxybutyrate and had a weight average molar mass of 5.5 x 10(5) g mol(-1) and a polydispersity of 1.6. an orf encoding a ...200111739767
rapid phenotypic change and diversification of a soil bacterium during 1000 generations of experimental evolution.evolutionary pathways open to even relatively simple organisms, such as bacteria, may lead to complex and unpredictable phenotypic changes, both adaptive and non-adaptive. the evolutionary pathways taken by 18 populations of ralstonia strain tfd41 while they evolved in defined environments for 1000 generations were examined. twelve populations evolved in liquid media, while six others evolved on agar surfaces. phenotypic analyses of these derived populations identified some changes that were con ...200111283295
[avoidable "fever of unknown origin" due to ralstonia pickettii bacteremia].ralstonia pickettii bacteraemia from the atrial part of a ventriculo-atrial shunt was diagnosed as the cause of recurring febrile episodes with systemic toxicity in a 38-year old female. a prior neurosurgical resection of intracerebral cavernoma was complicated by postoperative recurrent meningitis with this non-fermenting gram-negative rod, due to an intra-operative contamination of a in situ shunt, from which only the intracerebral part of the ventriculo-atriostomy had been removed, following ...200111307484
burkholderia cepacia genomovar vi, a new member of the burkholderia cepacia complex isolated from cystic fibrosis patients.a polyphasic taxonomic study was performed on 23 strains isolated from cystic fibrosis (cf) patients in the usa. these strains were tentatively identified as burkholderia cepacia, burkholderia vietnamiensis and burkholderia or ralstonia sp. using biochemical tests and 16s rdna-based pcr assays. visual comparison of protein profiles indicated that they belonged to a single new group ('group 13'). the polyphasic taxonomic data showed that 18 of these strains represent a new member of the b. cepaci ...200111321071
classification of ralstonia pickettii biovar 3/'thomasii' strains (pickett 1994) and of new isolates related to nosocomial recurrent meningitis as ralstonia mannitolytica sp. nov.strains isolated independently from two patients could be recognized as ralstonia pickettii biovar 3/'thomasii'. the 16s rdna sequences of these strains and two other strains of r. pickettii biovar 3/'thomasii' clustered at less than 98% similarity versus all other described ralstonia species and at less than 97 % versus the two other r. pickettii biovars. the separate species status of r. pickettii biovar 3/'thomasii' was confirmed by dna-dna hybridization, indicating less than 60% dna homology ...200111321101
a microbial biosensor to predict bioavailable nickel in soil and its transfer to plants.ralstonia eutropha strain ae2515 was constructed and optimised to serve as a whole-cell biosensor for the detection of bioavailable concentrations of ni2+ and co2+ in soil samples. strain ae2515 is a ralstonia eutropha ch34 derivative containing pmol1550, in which the cnryxh regulatory genes are transcriptionally fused to the bioluminescent luxcdabe reporter system. strain ae2515 was standardised for its specific responses to co2+ and ni2+. the detection limits for ae2515 were 0.1 microm ni2+ an ...200111351758
cloning, nucleotide sequencing, and functional analysis of a novel, mobile cluster of biodegradation genes from pseudomonas aeruginosa strain jb2.we have identified in pseudomonas aeruginosa strain jb2 a novel cluster of mobile genes encoding degradation of hydroxy- and halo-aromatic compounds. nineteen open reading frames were located and, based on sequence similarities, were putatively identified as encoding a ring hydroxylating oxygenase (hybabcd), an atp-binding cassette-type transporter, an extradiol ring-cleavage dioxygenase, transcriptional regulatory proteins, enzymes mediating chlorocatechol degradation, and transposition functio ...200111571162
2,4-dichlorophenoxyacetate/alpha-ketoglutarate dioxygenases from burkholderia cepacia 2a and ralstonia eutropha jmp134.2,4-dichlorophenoxyacetate (2,4-d)/alpha-ketoglutarate (alpha-kg) dioxygenase has been purified to apparent homogeneity from burkholderia cepacia strain 2a, which utilizes 2,4-d as sole carbon source. the enzyme required ferrous ions, and was a homodimer composed of subunits having an mr of approximately 32,000. the reaction catalysed consumed one mol each of 2,4-d, alpha-kg and dioxygen, with the production of one mol each of succinate, 2,4-dichlorophenol and glyoxylate. maximum activity was ex ...200111368091
novel hemoglobins to enhance microaerobic growth and substrate utilization in escherichia coli.limited oxygen availability is a prevalent problem in microbial biotechnology. recombinant escherichia coli expressing the hemoglobin from vitreoscilla (vhb) or the flavohemoglobin from ralstonia eutropha (formerly alcaligenes eutrophus) (fhp) demonstrate significantly increased cell growth and productivity under microaerobic conditions. we identify novel bacterial hemoglobin-like proteins and examine if these novel bacterial hemoglobins can elicit positive effects similar to vhb and fhp and if ...200111587567
the chlorocatechol degradative genes, tfdt-cdef, of burkholderia sp. strain nk8 are involved in chlorobenzoate degradation and induced by chlorobenzoates and chlorocatechols.the modified-ortho pathway genes responsible for the degradation of chlorocatechols produced from 3- and 4-chlorobenzoate in burkholderia sp. nk8 were cloned and analyzed. the five genes predicted to encode a lysr-type transcriptional regulator, chlorocatechol 1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase were designated tfdt, tfdc, tfdd, tfde, and tfdf, respectively since they show the highest similarity to the corresponding genes of the chl ...200111368916
surfactant protein interactions with neutral and acidic phospholipid films.the captive bubble tensiometer was employed to study interactions of phospholipid (pl) mixtures of dipalmitoylphosphatidylcholine (dppc) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (popc) or 1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (popg) at 50 microg/ml with physiological levels of the surfactant protein (sp) a sp-b, and sp-c alone and in combination at 37 degrees c. all surfactant proteins enhanced lipid adsorption to equilibrium surface tension (gamma), with sp-c ...200111404266
effects of 2,2',5,5'-tetrachlorobiphenyl and biphenyl on cell membranes of ralstonia eutropha h850.the effects of 2,2',5,5'-tetrachlorobiphenyl (tecb), a pcb congener, and biphenyl on the cytoplasmic membranes of ralstonia eutropha h850 were investigated by measuring fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene (dph) as the probe, and determining the cellular fatty acid compositions. tecb significantly affected the membrane of r. eutropha h850 cells grown on fructose by decreasing dph fluorescence polarization. in contrast, the membrane of cells grown on biphenyl showed a con ...200111410343
albibacter methylovorans gen. nov., sp. nov., a novel aerobic, facultatively autotrophic and methylotrophic bacterium that utilizes dichloromethane.a novel genus, albibacter, with one species, albibacter methylovorans sp. nov., is proposed for a facultatively chemolithotrophic and methylotrophic bacterium (strain dm10t) with the ribulose bisphosphate (rubp) pathway of c1 assimilation. the bacterium is a gram-negative, aerobic, asporogenous, nonmotile, colourless rod that multiplies by binary fission. the organism utilizes dichloromethane, methanol, methylamine, formate and co2/h2, as well as a variety of polycarbon compounds, as carbon and ...200111411673
characterization of the reduction of selenate and tellurite by nitrate reductases.preliminary studies showed that the periplasmic nitrate reductase (nap) of rhodobacter sphaeroides and the membrane-bound nitrate reductases of escherichia coli are able to reduce selenate and tellurite in vitro with benzyl viologen as an electron donor. in the present study, we found that this is a general feature of denitrifiers. both the periplasmic and membrane-bound nitrate reductases of ralstonia eutropha, paracoccus denitrificans, and paracoccus pantotrophus can utilize potassium selenate ...200111679335
poly(3-hydroxybutyrate) synthesis genes in azotobacter sp. strain fa8.genes responsible for the synthesis of poly(3-hydroxybutyrate) (phb) in azotobacter sp. fa8 were cloned and analyzed. a phb polymerase gene (phbc) was found downstream from genes coding for beta-ketothiolase (phba) and acetoacetyl-coenzyme a reductase (phbb). a phb synthase mutant was obtained by gene inactivation and used for genetic studies. the phbc gene from this strain was introduced into ralstonia eutropha phb-4 (phbc-negative mutant), and the recombinant accumulated phb when either glucos ...200111679365
kinetic analysis on formation of poly(3-hydroxybutyrate) from acetic acid by ralstonia eutropha under chemically defined conditions.batch cultures of ralstonia eutropha in chemically defined media with acetic acid (hac) as the sole carbon source were conducted to investigate acetate utilization, formation of poly(3-hydroxybutyrate) (phb) and growth of active biomass (abm) under different carbon to nitrogen (c/n) weight ratios. the specific acetate utilization rate based on abm approached 0.16 g/g abm h(-1), which was not affected very much by the extracellular hac concentration from 1 to 5 g/l, but was affected by the c/n we ...200111420650
ralstonia metallidurans ch34 rpon sigma factor and the control of nitrogen metabolism and biphenyl utilization.ralstonia metallidurans ch34 can use biphenyl as carbon and energy source when provided with the catabolic transposon tn4371. previous results suggested that this property was dependent on the rna polymerase subunit sigma(54). the authors sequenced the ch34 rpon gene and flanking dna and isolated a ch34 rpon-deficient strain. analysis of the sequence revealed a set of features conserved in all rpon genes and flanking dna regions previously analysed in other bacterial species. nevertheless, despi ...200111429471
dual-bioaugmentation strategy to enhance remediation of cocontaminated soil.although metals are thought to inhibit the ability of microorganisms to degrade organic pollutants, several microbial mechanisms of resistance to metal are known to exist. this study examined the potential of cadmium-resistant microorganisms to reduce soluble cadmium levels to enhance degradation of 2,4-dichlorophenoxyacetic acid (2,4-d) under conditions of cocontamination. four cadmium-resistant soil microorganisms were examined in this study. resistant up to a cadmium concentration of 275 micr ...200111425743
in vivo detection of the cyclic osmoregulated periplasmic glucan of ralstonia solanacearum by high-resolution magic angle spinning nmr.we investigate the mobility of the osmoregulated periplasmic glucans of ralstonia solanacearum in the bacterial periplasm through the use of high-resolution (hr) nmr spectroscopy under static and magic angle spinning (mas) conditions. because the nature of periplasm is far from an isotropic aqueous solution, the molecules could be freely diffusing or rather associated to a periplasmic protein, a membrane protein, a lipid, or the peptidoglycan. hr mas nmr spectroscopy leads to more reproducible r ...200111444945
assessment of a simple, non-toxic alamar blue cell survival assay to monitor tomato cell viability.the alamar blue (ab) assay, which incorporates a medox indicator that changes colour or fluorescence in response to metabolic activity, is commonly used to assess quantitatively the viability and/or proliferation of mammalian cells and micro-organisms. in this study the ab assay was adapted for the determination of the viability of plant cells. cell suspension cultures of tomato, lycopersicon esculentum, l., with differing viabilities, served as the experimental model for a comparison of the ab ...200111705263
[ralstonia pickettii pneumonia in an inmunocompetent adult]. 200111707228
production of poly(3-hydroxybutyrateco-3-hydroxyvalerate) from cottonseed oil and valeric acid in batch culture of raistonia sp. strain jc-64.a ralstonia sp. strain jc-64 that is capable of accumulating poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (p[3hb-co-3hv]) from cottonseed oil and valeric acid was isolated. by using a high limiting-nitrogen (hln) mineral medium as the medium for the second stage of the fermentation process and by adding the two carbon sources at different times, a range of copolymers with 12-62 mol% of 3hv were produced from a series of hln mineral mediums containing different compositions of cottonseed oil and ...200111456295
a physical map of the megaplasmid phg1, one of three genomic replicons in ralstonia eutropha h16.we have used pulsed field gel electrophoresis and megabase dna techniques to investigate the basic genomic organization of ralstonia eutropha h16, and to construct a physical map of its indigenous megaplasmid phg1. this gram-negative, soil-dwelling bacterium is a facultative chemolithoautotroph and a denitrifier. in the absence of organic substrates it can grow on h2 as its sole energy source and co2 as its sole source of carbon. under anaerobic conditions it can utilize nitrate as a terminal el ...200111470364
ethanedisulfonate is degraded via sulfoacetaldehyde in ralstonia sp. strain eds1.aerobic enrichment cultures (11) yielded three cultures able to utilise ethane-1,2-disulfonate as sole source of carbon and energy in salts medium. two pure cultures were obtained and we worked with strain eds1, which was assigned to the genus ralstonia on the basis of its 16s rdna sequence and simple taxonomic tests. strain eds1 utilised at least seven alkane(di)sulfonates, ethane-1,2-disulfonate, taurine, isethionate, sulfoacetate, sulfoacetaldehyde and propane-1,3-disulfonate, as well as meth ...200111479707
identification and characterization of a periplasmic nitrate reductase in azospirillum brasilense sp245.the azospirillum brasilense sp245 napabc genes, encoding nitrate reductase activity, were isolated and sequenced. the derived protein sequences are very similar throughout the whole nap segment to the napabc protein sequences of escherichia coli, pseudomonas sp. g-179, ralstonia eutropha, rhodobacter sphaeroides, and paracoccus denitrificans. based on whole-cell nitrate reductase assays with the artificial electron donors benzyl viologen and methyl viologen, and assays with periplasmic cell-free ...200111409544
metabolic and kinetic analysis of poly(3-hydroxybutyrate) production by recombinant escherichia coli.a quantitatively repeatable protocol was developed for poly(3-hydroxybutyrate) (phb) production by escherichia coli xl1-blue (psyl107). two constant-glucose fed-batch fermentations of duration 25 h were carried out in a 5-l bioreactor, with the measured oxygen volumetric mass-transfer coefficient (k(l)a) held constant at 1.1 min(-1). all major consumption and production rates were quantified. the intracellular concentration profiles of acetyl-coa (300 to 600 microg x g rcm(-1)) and 3-hydroxybuty ...200111353412
characterization of (r/s)-mecoprop [2-(2-methyl-4-chlorophenoxy) propionic acid]-degrading alcaligenes sp.cs1 and ralstonia sp. cs2 isolated from agricultural soils.the herbicide mecoprop [2-(2-methyl-4-chlorophenoxy) propionic acid] is widely applied to corn fields in order to control broad-leaved weeds. however, it is often detected in groundwater where it can be a persistent contaminant. two mecoprop-degrading bacterial strains were isolated from agricultural soils through their capability to degrade (r/s)-mecoprop rapidly. 16s rdna sequencing of the isolates demonstrated that one was closely related to the genera alcaligenes sp. (designated cs1) and the ...200111359515
catalytic and molecular properties of the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase from ralstonia eutropha strain bo.the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (thfa-dh) from ralstonia eutropha strain bo was investigated for its catalytic properties. the apparent k(cat)/k(m) and k(i) values for several substrates were determined using ferricyanide as an artificial electron acceptor. the highest catalytic efficiency was obtained with n-pentanol exhibiting a k(cat)/k(m) value of 788 x 10(4) m(-1) s(-1). the enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes inve ...200111222593
phenotypic methods for determining genomovar status of the burkholderia cepacia complex.recent taxonomic advances have demonstrated that burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) collectively referred to as the b. cepacia complex, all of which may cause infections among cystic fibrosis patients and other vulnerable individuals. thus, it is important for clinical microbiologists to be able to differentiate genomovars. prior to this study, 361 b. cepacia complex isolates and 51 isolates easily confused with b. cepacia complex ...200111230429
generation of pcr-based dna fragments for specific detection of streptomyces saraceticus n45.streptomyces saraceticus strain n45, a saprophytic gram-positive bacteria, has been shown to harbor high chitinase activity. due to its potential use in biological control, the cloning of chitinase genes and the development of methods to quickly and precisely detect its presence have become necessary. in this study, pcr-based random amplified polymorphic dna (rapd) and pcr strategies were used to amplify random dna fragments from the genome of s. saraceticus n45. three amplified dna fragments, 4 ...200111370759
bacteriophage p4282, a parasite of ralstonia solanacearum, encodes a bacteriolytic protein important for lytic infection of its host.to enhance bacterial wilt resistance in tobacco expressing a foreign protein, we isolated the bacteriolytic gene from a bacteriophage that infects ralstonia solanacearum. the bacteriolytic protein of phage p4282 isolated in tochigi prefecture was purified from a lysate of r. solanacearum m4s cells infected with the phage, and its bacteriolytic activity was assayed by following the decrease in the turbidity of suspensions of r. solancacearum m4s cells. the molecular weight of the bacteriolytic pr ...200111370877
ralstonia solanacearum needs motility for invasive virulence on tomato.ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. by examining bacteria from the xylem vessels of infected plants, we found that r. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. to determine the role of pathogen motility in this disease, we cloned, charac ...200111371523
transposon mutagenesis in purple sulfur photosynthetic bacteria: identification of hypf, encoding a protein capable of processing [nife] hydrogenases in alpha, beta, and gamma subdivisions of the proteobacteria.a random transposon-based mutagenesis system was optimized for the purple sulfur phototrophic bacterium thiocapsa roseopersicina bbs. screening for hydrogenase-deficient phenotypes resulted in the isolation of six independent mutants in a mini-tn5 library. one of the mutations was in a gene showing high amino acid sequence similarity to hypf proteins in other organisms. inactivation of hydrogen uptake activity in the hypf-deficient mutant resulted in a dramatic increase in the hydrogen evolution ...200111375153
continuous production of poly-3-hydroxybutyrate by ralstonia eutropha in a two-stage culture system.poly-3-hydroxybutyrate (phb) is mainly accumulated by ralstonia eutropha under unbalanced growth conditions, which limits its production in batch or fed-batch modes. the continuous production of phb was investigated in a two-stage continuous culture system. the first-stage produced cell mass giving the maximal cell dry weight of 27.1 g l(-1) at 0.21 h(-1) of dilution rate. high specific cell growth rate results in the decrease of phb synthesis under glucose-limited and nitrogen-rich conditions i ...200111377765
frankia kb5 possesses a hydrogenase immunologically related to membrane-bound.the immunological relationship of the hydrogenase in frankia kb5 to hydrogenases in other microorganisms was investigated using antisera raised against holo-[nife]-hydrogenases isolated from alcaligenes latus, azotobacter vinelandii, ralstonia eutropha, and the small and large hydrogenase subunits from bradyrhizobium japonicum. the antisera raised against the a. latus, r. eutropha, and b. japonicum (large subunit) polypeptides were found to recognize two polypeptides, corresponding to the unproc ...200111381338
isolation and characterization of a thermotolerant bacterium ralstonia sp. strain phs1 that degrades benzene, toluene, ethylbenzene, and o-xylene.a thermotolerant bacterium, designated as phs1, was isolated from a hot spring in pohang, korea, on the basis of its ability to grow on benzene, toluene, ethylbenzene, and xylenes (btex) as a sole carbon source. strain phs1 is a gram-negative, rod-shaped aerobe and grows optimally at 42 degrees c and ph 7.2. according to 16 s rdna analysis, strain phs1 showed highest similarity to ralstonia eutropha (previously named alcaligenes eutrophus). unlike its closest known ralstonia species, however, st ...200111499943
polychlorinated biphenyl degradation activities and hybridization analyses of fifteen aerobic strains isolated from a pcb-contaminated site.fifteen bacterial strains using biphenyl as sole carbon and energy source, obtained from different positions and depths of a polychlorinated biphenyl (pcb)-contaminated area, were analyzed for their basic metabolic phenotypes and subjected to genomic dna hybridization screening for the presence of well characterized bph operons such as those of pseudomonas pseudoalcaligenes kf707 and rhodococcus globerulus p6. most of the isolates belonged to the gamma-subdivision (pseudomonas stutzeri, p. pluti ...200111501677
molecular characterization and heterologous expression of hypcd, the first two [nife] hydrogenase accessory genes of thermococcus litoralis.the hypcd genes, encoding the counterparts of mesophilic proteins involved in the maturation of [nife] hydrogenases, were isolated from the hyperthermophilic archaeon thermococcus litoralis. the deduced gene products showed 30-40% identity to the corresponding mesophilic proteins. hypc and hypd were synthesized by the t7 expression system. heterologous complementation experiments were done in escherichia coli and ralstonia eutropha strains lacking functionally active hypc and hypd genes. only th ...200111511872
mobilization of selenite by ralstonia metallidurans ch34.ralstonia metallidurans ch34 (formerly alcaligenes eutrophus ch34) is a soil bacterium characteristic of metal-contaminated biotopes, as it is able to grow in the presence of a variety of heavy metals. r. metallidurans ch34 is reported now to resist up to 6 mm selenite and to reduce selenite to elemental red selenium as shown by extended x-ray absorption fine-structure analysis. growth kinetics analysis suggests an adaptation of the cells to the selenite stress during the lag-phase period. depen ...200111157242
source of resistance against ralstonia solanacearum in fertile somatic hybrids of eggplant (solanum melongena l.) with solanum aethiopicum l.solanum aethiopicum is reported to carry resistance to bacterial wilt disease caused by ralstonia solanacearum, which is one of the most important diseases of eggplant (solanum melongena). these two species can sexually be crossed but the fertility of their progeny is very low. in order to transfer the resistance and improve the fertility, somatic hybrids between s. melongena cv. dourga and two groups of s. aethiopicum were produced by electrical fusion of mesophyll protoplasts. thirty hybrid pl ...200111164602
mechanistic studies on class i polyhydroxybutyrate (phb) synthase from ralstonia eutropha: class i and iii synthases share a similar catalytic mechanism.the class i and iii polyhydroxybutyrate (phb) synthases from ralstonia eutropha and chromatium vinosum, respectively, catalyze the polymerization of beta-hydroxybutyryl-coenzyme a (hbcoa) to generate phb. these synthases have different molecular weights, subunit composition, and kinetic properties. recent studies with the c. vinosum synthase suggested that it is structurally homologous to bacterial lipases and allowed identification of active site residues important for catalysis [jia, y., kappo ...200111170423
molecular characterization of a deletion/duplication rearrangement in tfd genes from ralstonia eutropha jmp134(pjp4) that improves growth on 3-chlorobenzoic acid but abolishes growth on 2,4-dichlorophenoxyacetic acid.ralstonia eutropha jmp134(pjp4) is able to grow on minimal media containing the pollutants 3-chlorobenzoate (3-cb) or 2,4-dichlorophenoxyacetate (2,4-d). tfd genes from the 88 kb plasmid pjp4 encode enzymes involved in the degradation of these compounds. during growth of strain jmp134 in liquid medium containing 3-cb, a derivative strain harbouring a approximately 95 kb plasmid was isolated. this derivative, designated jmp134(pjp4-f3), had an improved ability to grow on 3-cb, but had lost the ab ...200111495991
the methylcitric acid pathway in ralstonia eutropha: new genes identified involved in propionate metabolism.from ralstonia eutropha hf39 null-allele mutants were created by tn5 mutagenesis and by homologous recombination which were impaired in growth on propionic acid and levulinic acid. from the molecular, physiological and enzymic analysis of these mutants it was concluded that in this bacterium propionic acid is metabolized via the methylcitric acid pathway. the genes encoding enzymes of this pathway are organized in a cluster in the order prpr, prpb, prpc, acnm, orf5 and prpd, with prpr transcribe ...200111495997
biodegradation of synthetic and naturally occuring mixtures of mono-cyclic aromatic compounds present in olive mill wastewaters by two aerobic bacteria.two bacterial strains, ralstonia sp. ld35 and pseudomonas putida dsm 1868, were assayed for their ability to degrade the monocyclic aromatic compounds commonly found in olive mill wastewaters (omws). the goal was to study the possibility of employing the two strains in the removal of these recalcitrant and toxic compounds from the effluents of anaerobic treatment plants fed with omws. at first, the two strains were separately assayed for their ability to degrade a synthetic mixture of nine aroma ...200111414330
accumulation of the phap phasin of ralstonia eutropha is dependent on production of polyhydroxybutyrate in cells.polyhydroxyalkanoates (phas) are polyoxoesters that are produced by diverse bacteria and that accumulate as intracellular granules. phasins are granule-associated proteins that accumulate to high levels in strains that are producing phas. the accumulation of phasins has been proposed to be dependent on pha production, a model which is now rigorously tested for the phasin phap of ralstonia eutropha. r. eutropha phac pha synthase and phap phasin gene replacement strains were constructed. the strai ...200111418562
isafe1, an isl3 family insertion sequence from acidithiobacillus ferrooxidans atcc 19859.a 1.3-kb insertion sequence, termed isafe1 (u66426), from acidithiobacillus ferrooxidans atcc 19859 is described. isafe1 exhibits the features of a typical bacterial insertion sequence. it has 26-bp, imperfectly matched, terminal inverted repeats and an open reading frame (orf) that potentially encodes a transposase (tpase) of 404 amino acids (aab07489) with significant similarity to members of the isl3 family of insertion sequences. a potential ribosome-binding site and potential -10 and -35 pr ...200111418574
construction and characterization of a xanthomonas oryzae pv. oryzae bacterial artificial chromosome library.xanthomonas oryzae pv. oryzae is an important plant pathogen which causes bacterial blight of rice. to facilitate genome studies of this bacterium, we have constructed a bacterial artificial chromosome (bac) library of strain maff 311018. it consisted of 750 clones representing 16 genome equivalents, and had an insert size ranging from 20 to 220 kb with an average size of 107 kb. this library is the first to be constructed from a x. oryzae pv. oryzae strain. the usefulness of this library was de ...200111410350
methanogen and bacterial diversity and distribution in deep gas hydrate sediments from the cascadia margin as revealed by 16s rrna molecular analysis.the microbial community of a deep (to 234 m below the sea floor) sediment gas hydrate deposit (cascadia margin ocean drilling program site 889/890, leg 146) was analysed for the first time by molecular genetic techniques. both bacterial and methanogen diversity were determined by phylogenetic analysis of ribosomal dna sequences. high molecular mass dna, indicative of active bacteria, was present in all of the samples. ribosomal rna genes were amplified from extracted dna extracted from sediment ...200111137602
genetic diversity of japanese strains of ralstonia solanacearum.abstract the genetic diversity of 74 japanese strains of ralstonia solanacearum was assessed by pathogenicity tests and the repetitive sequencebased polymerase chain reaction (rep-pcr) fingerprint method. based on their genomic fingerprints, biovar n2 strains were divided into two distinct groups, one consisting of potato isolates belonging to race 3, and the other consisting of tomato, eggplant, pepper, and tobacco isolates belonging to race 1. biovar 3 strains had low average similarity and we ...200118943853
biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyalkanoates) copolymer from sugars by recombinant ralstonia eutropha harboring the phac1ps and the phagps genes of pseudomonas sp. 61-3.heterologous expression of the phagps and the phaclps genes encoding 3-hydroxyacyl acyl carrier protein-coenzyme a transacylase and polyhydroxyalkanoate (pha) synthase from pseudomonas sp. 61-3, respectively, was performed in the phbcre negative mutant, ralstonia eutropha phb-4. the recombinant strain of the r. eutropha phb-4 produced pha copolymers consisting of 3-hydroxybutyrate (3hb) and medium-chain-length 3-hydroxyalkanoate (mcl-3ha) units of 6-12 carbon atoms from sugars. the 3hb fraction ...200111710052
development of a novel method for feeding a mixture of l-lactic acid and acetic acid in fed-batch culture of ralstonia eutropha for poly-d-3-hydroxybutyrate production.fermentative production of poly-d-3-hydroxybutyrate [p(3hb)] from a mixture of l-lactic acid and acetic acid by ralstonia eutropha was investigated. for fed-batch culture with cell density, it is necessary to control the concentration of these organic acids in the culture medium below the inhibitory level for cell growth. therefore, a novel feeding method, termed the computer-controlled ph-stat substrate feeding method, was developed using the rate of increase of the ph (ph-increasing rate) of t ...200116233037
amplification of the nadph-related genes zwf and gnd for the oddball biosynthesis of phb in an e. coli transformant harboring a cloned phbcab operon.nadph, a major reducing power in microorganisms, is mostly generated from the pentose phosphate (pp) pathway by glucose-6-phosphate dehydrogenase (g6pdh) and 6-phosphogluconate dehydrogenase (6pgdh) expressed by the zwf and gnd genes, respectively. the characteristics of these two genes in escherichia coli were compared after their re-introduction into the parent strain for over-expression. zwf encoding g6pdh increased the level of nadph 3 folds compared to gnd encoding 6pgdh. an excess of nadph ...200216233247
cloning of an intracellular d(-)-3-hydroxybutyrate-oligomer hydrolase gene from ralstonia eutropha h16 and identification of the active site serine residue by site-directed mutagenesis.an intracellular d(-)-3-hydroxybutyrate (3hb)-oligomer hydrolase gene from ralstonia eutropha (formerly alcaligenes eutrophus) h16 was cloned, sequenced, and characterized. as a hybridization probe to screen restriction digests of chromosomal dna, an extracellular 3hb-oligomer hydrolase gene from ralstonia pickettii strain (formerly pseudomonas sp. strain) a1 was used. a specific hybridization signal was obtained and a 6.5-kbp smai fragment was cloned in an escherichia coli phagemid vector. the ...200216233278
delayed symptom development in ein2-1, an arabidopsis ethylene-insensitive mutant, in response to bacterial wilt caused by ralstonia solanacearum.abstract wilt disease caused by the phytopathogenic bacterium ralstonia solanacearum is poorly understood at the molecular level. the possible roles of salicylic acid, jasmonic acid, and ethylene, compounds commonly associated with the plant response to pathogens, in wilt symptom development were investigated using various arabidopsis thaliana mutants in a col-0 background, an ecotype that develops wilt symptoms in response to the virulent gmi1000 strain. following root inoculation, wilt symptom ...200218944225
expression of tfda genes in aquatic microbial communities during acclimation to 2,4-dichlorophenoxyacetic acid.the role of gene expression during acclimation of aquatic microbial communities was examined by relating transcription of tfda to the degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-d). the tfda gene encodes for a 2,4-d/2-oxoglutarate dioxygenase that transforms 2,4-d to 2,4-dichlorophenol. transcription of tfda, the abundance of tfda genes and 2,4-d degrading populations, and the rate of 2,4-d disappearance were followed in laboratory incubations of two pond water samples that ...200219709228
interactions of earthworms with indigenous and bioaugmented pcb-degrading bacteria.partial bioremediation of polychlorinated biphenyl (pcb)-contaminated soils has been achieved using bioaugmentation with pcb-degrading bacteria and earthworms. to further study the contribution of earthworms to bioremediation, an experiment was conducted in which the changes in indigenous and bioaugmented pcb-degrading bacteria were analyzed during treatment of contaminated soil using earthworms (pheretima hawayana) alone or in combination with the pcb-degrading bacteria, ralstonia eutrophus and ...200219709253
the ralstonia eutropha phar protein couples synthesis of the phap phasin to the presence of polyhydroxybutyrate in cells and promotes polyhydroxybutyrate production.polyhydroxyalkanoates (phas) are polyoxoesters that are produced by many bacteria and that accumulate as intracellular granules. phasins (phap) are proteins that accumulate during pha synthesis, bind pha granules, and promote further pha synthesis. interestingly, phap accumulation seems to be strictly dependent on pha synthesis, which is catalyzed by the phac pha synthase. here we have tested the effect of the ralstonia eutropha phar protein on the regulation of phap accumulation. r. eutropha st ...200211741844
novel 2,4-dichlorophenoxyacetic acid degradation genes from oligotrophic bradyrhizobium sp. strain hw13 isolated from a pristine environment.the tfd genes of ralstonia eutropha jmp134 are the only well-characterized set of genes responsible for 2,4-dichlorophenoxyacetic acid (2,4-d) degradation among 2,4-d-degrading bacteria. a new family of 2,4-d degradation genes, cadrabkc, was cloned and characterized from bradyrhizobium sp. strain hw13, a strain that was isolated from a buried hawaiian soil that has never experienced anthropogenic chemicals. the cadr gene was inferred to encode an arac/xyls type of transcriptional regulator from ...200211751829
chimeric vitreoscilla hemoglobin (vhb) carrying a flavoreductase domain relieves nitrosative stress in escherichia coli: new insight into the functional role of vhb.dimeric hemoglobin (vhb) from the bacterium vitreoscilla sp. strain c1 displays 30 to 53% sequence identity with the heme-binding domain of flavohemoglobins (flavohbs) and exhibits the presence of potential sites for the interaction with its fad/nadh reductase partner. the intersubunit contact region of vhb indicates a small interface between two monomers of the homodimer, suggesting that the vhb dimers may dissociate easily. gel filtration chromatography of vhb exhibited a 25 to 30% monomeric p ...200211772621
identification of the 2-methylcitrate pathway involved in the catabolism of propionate in the polyhydroxyalkanoate-producing strain burkholderia sacchari ipt101(t) and analysis of a mutant accumulating a copolyester with higher 3-hydroxyvalerate content.burkholderia sacchari ipt101(t) induced the formation of 2-methylcitrate synthase and 2-methylisocitrate lyase when it was cultivated in the presence of propionic acid. the prp locus of b. sacchari ipt101(t) is required for utilization of propionic acid as a sole carbon source and is relevant for incorporation of 3-hydroxyvalerate (3hv) into copolyesters, and it was cloned and sequenced. five genes (prpr, prpb, prpc, acnm, and orf5) exhibited identity to genes located in the prp loci of other gr ...200211772636
infection by ralstonia species in cystic fibrosis patients: identification of r. pickettii and r. mannitolilytica by polymerase chain reaction.the frequency of respiratory tract infections caused by ralstonia species in persons with cystic fibrosis (cf) and the role of these species in cf pulmonary disease are not well documented. in part, this lack of documentation may be attributed to the difficulty in accurately identifying ralstonia species; r. mannitolilytica and r. pickettii in particular may be misidentified as other closely related species, particularly those of the burkholderia cepacia complex. we used polyphasic analyses to i ...200212095436
characterization of microbial polythioesters: physical properties of novel copolymers synthesized by ralstonia eutropha.various samples of polythioesters with different contents of 3-mercaptopropionic acid (3mp) or 3-mercaptobutyric acid (3mb) as one comonomer and with 3-hydroxybutyric acid (3hb) as the second constituent were produced by cultivating cells of ralstonia eutropha strain h16 in mineral salts medium containing 3mp or 3mb plus gluconate as carbon sources. fermentations were done also at the 30-l scale. the various samples were cast as films from chloroform and the following were recorded: melting poin ...200211866569
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