Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| chemotaxis of ralstonia eutropha jmp134(pjp4) to the herbicide 2,4-dichlorophenoxyacetate. | ralstonia eutropha jmp134(pjp4) and several other species of motile bacteria can degrade the herbicide 2,4-dichlorophenoxyacetate (2,4-d), but it was not known if bacteria could sense and swim towards 2,4-d by the process of chemotaxis. wild-type r. eutropha cells were chemotactically attracted to 2,4-d in swarm plate assays and qualitative capillary assays. the chemotactic response was induced by growth with 2,4-d and depended on the presence of the catabolic plasmid pjp4, which harbors the tfd ... | 2002 | 11823246 |
| genome sequence of the plant pathogen ralstonia solanacearum. | ralstonia solanacearum is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. it is a model system for the dissection of molecular determinants governing pathogenicity. we present here the complete genome sequence and its analysis of strain gmi1000. the 5.8-megabase (mb) genome is organized into two replicons: a 3.7-mb chromosome and a 2.1-mb megaplasmid. both replicons have a mosaic structure providing evidence for the acquisition of genes throu ... | 2002 | 11823852 |
| molecular characterization of the poly(3-hydroxybutyrate) (phb) synthase from ralstonia eutropha: in vitro evolution, site-specific mutagenesis and development of a phb synthase protein model. | a threading model of the ralstonia eutropha polyhydroxyalkanoate (pha) synthase was developed based on the homology to the burkholderia glumae lipase, whose structure has been resolved by x-ray analysis. the lid-like structure in the model was discussed. in this study, various r. eutropha pha synthase mutants were generated employing random as well as site-specific mutagenesis. four permissive mutants (double and triple mutations) were obtained from single gene shuffling, which showed reduced ac ... | 2002 | 11825620 |
| [study on the heterogeneity of lipopolysaccharides of ralstonia solanacearum]. | methods of electrophoresis in polyacrylamide gel in the system of sodium dodecyl sulphate (sds-page) with immunoblotting were used to investigate heterogeneity of lipopolysaccharides (lps) of ralstonia solanacearum (icmp 8110, 767, 5712, 7955, 7945, 7944, 8089 and 4157) which were characterized by various type structure of o-specific polysaccharides chains. when carrying out sds-page, it was determined that lps of all the investigated strains display bimodal distribution, typical of s-form lps a ... | 2002 | 12664545 |
| 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 ... | 2002 | 11866569 |
| formation of short chain length/medium chain length polyhydroxyalkanoate copolymers by fatty acid beta-oxidation inhibited ralstonia eutropha. | ralstonia eutropha has been considered as a bacterium, incorporating hydroxyalkanoates of less than six carbons only into polyhydroxyalkanoates (phas). cells of the wild type cultivated with sodium octanoate as the carbon source in the presence of the fatty acid beta-oxidation inhibitor sodium acrylate synthesized phas composed of the medium chain length hydroxyalkanoates (3ha(mcl)) 3-hydroxyhexanoate (3hhx) and 3-hydroxyoctanoate (3ho) as well as of 3-hydroxybutyrate and 3-hydroxyproprionate as ... | 2002 | 11866575 |
| long pcr-amplified rdna for pcr-rflp- and rep-pcr-based approaches to recognize closely related microbial species. | long pcr was used to amplify a 5-kb fragment of the bacterial ribosomal operon (16s-intergenic spacer region (isr)-23s) from several ralstonia eutropha strains (16s rdna sequence similarity: 97-99%). due to the large product size, amplicons from the different strains could be distinguished using restriction enzyme fragment length polymorphisms (rflp) and repetitive pcr analysis (rep-pcr) with the primer 1492r. these methods may prove useful in differentiating other bacterial strains with highly ... | 2002 | 11869797 |
| salicylate 5-hydroxylase from ralstonia sp. strain u2: a monooxygenase with close relationships to and shared electron transport proteins with naphthalene dioxygenase. | the genes from the oxygenase cluster nagaaghabacad of naphthalene-degrading ralstonia sp. strain u2 were cloned and overexpressed. salicylate 5-hydroxylase (s5h) activity, converting salicylate to gentisate, was present in vitro only in the single extract of cells with overexpressed nagaaghab or in a mixture of three cell extracts containing, respectively, naggh (the oxygenase components), nagaa (ferredoxin reductase), and nagab (ferredoxin). each of the three extracts required for s5h activity ... | 2002 | 11872705 |
| molecular detection and diversity of polycyclic aromatic hydrocarbon-degrading bacteria isolated from geographically diverse sites. | nineteen polycyclic aromatic hydrocarbon (pah)-degrading bacteria were isolated from environmental samples in kuwait, indonesia, thailand, and japan by enrichment with either naphthalene or phenanthrene as a sole carbon source. sequence analyses of the 16-s rrna gene indicated that at least seven genera (ralstonia, sphingomonas, burkholderia, pseudomonas, comamonas, flavobacterium, and bacillus) were present in this collection. determination of the ability of the isolates to use pah and its pres ... | 2002 | 11876413 |
| a signal transfer system through three compartments transduces the plant cell contact-dependent signal controlling ralstonia solanacearum hrp genes. | ralstonia solanacearum hrp genes encode a type iii secretion system required for disease development in host plants and for hypersensitive response elicitation on non-hosts. hrp genes are expressed in the presence of plant cells through the hrpb regulator. this activation, which requires physical interaction between the bacteria and the plant cell, is sensed by the outer membrane receptor prha. prha transduces the plant cell contact-dependent signal through a complex regulatory cascade integrate ... | 2002 | 11876423 |
| cloning, characterization and comparison of the pseudomonas mendocina polyhydroxyalkanoate synthases phac1 and phac2. | this study describes a comparison of the polyhydroxyalkanoate (pha) synthases phac1 and phac2 of pseudomonas mendocina. the p mendocina pha gene locus, encoding two pha synthase genes [phac1pm and phac2pm flanking a pha depolymerase gene (phaz)], was cloned, and the nucleotide sequences of phac1pm (1,677 bp), phaz (1,034 bp), and phac2pm (1,680 bp) were determined. the amino acid sequences deduced from phac1pm and phac2pm showed highest similarities to the corresponding pha synthases from other ... | 2002 | 11878309 |
| characterization of the zat1p zinc transporter from arabidopsis thaliana in microbial model organisms and reconstituted proteoliposomes. | the zat1p zinc transporter from arabidopsis thaliana (l.) heynh. is a member of the cation diffusion facilitator (cdf) protein family. when heterologously expressed in escherichia coli, zat1p bound zinc in a metal blot. binding of zinc occurred mainly to the hydrophilic amino acid region from h182 to h232. a zat1p/zat1p*delta(m1-i25) protein mixture was purified and reconstituted into proteoliposomes. uptake of zinc into the proteoliposomes did not require a proton gradient across the liposomal ... | 2002 | 11882948 |
| characterization of tdt genes for the degradation of tricyclic diterpenes by pseudomonas diterpeniphila a19-6a. | resin acids are tricyclic diterpenes that are toxic to aquatic life when released in high concentrations in pulp mill effluents. these naturally formed organic acids are readily degraded by bacteria and fungi; nevertheless, many of the mechanisms involved are still unknown. we report the localization, cloning, and sequencing of genes for abietane degradation (9.18 kb; designated tdt (tricyclic diterpene) lrsabcd) from the gamma-proteobacterium pseudomonas diterpeniphila a19-6a. using gene knocko ... | 2002 | 11888163 |
| snakin-2, an antimicrobial peptide from potato whose gene is locally induced by wounding and responds to pathogen infection. | the peptide snakin-2 (stsn2) has been isolated from potato (solanum tuberosum cv jaerla) tubers and found to be active (ec(50) = 1-20 microm) against fungal and bacterial plant pathogens. it causes a rapid aggregation of both gram-positive and gram-negative bacteria. the corresponding stsn2 cdna encodes a signal sequence followed by a 15-residue acidic sequence that precedes the mature stsn2 peptide, which is basic (isoelectric point = 9.16) and 66 amino acid residues long (molecular weight of 7 ... | 2002 | 11891250 |
| identification and characterization of poly-3-hydroxybutyrate granule-associated protein, pga12 and pga16 in zoogloea ramigera i-16-m. | poly-3-hydroxybutyrate (phb) granules of zoogloea ramigera i-16-m contained two major phb granule-associated proteins (pga12 and pga16) as revealed by sodium dodecyl sulfate-polyacrylamide gel elecrophoresis. n-terminal amino acid sequences of these proteins were determined. the genes encoding these proteins were cloned and sequenced. the structural genes of pga12 and pga16 were 351 and 447 bp long, which encode polypeptides with deduced molecular masses of 12.3 and 16.0 kda, respectively. pga12 ... | 2002 | 11893394 |
| effect of increased pha synthase activity on polyhydroxyalkanoates biosynthesis in synechocystis sp. pcc6803. | polyhydroxyalkanoate (pha) synthase activity in synechocystis sp. pcc6803 was increased two-fold by introducing the pha biosynthetic genes of ralstonia eutropha. the resulting recombinant synechocystis sp. pcc6803 strain was subjected to conditions that favor pha accumulation and the effects of various carbon sources were studied. in addition, the fine structure of both wild-type and recombinant synechocystis sp. pcc6803 was examined using freeze-fracture electron microscopy technique. the pha g ... | 2002 | 11911900 |
| analysis of bacteria contaminating ultrapure water in industrial systems. | bacterial populations inhabiting ultrapure water (upw) systems were investigated. the analyzed upw systems included pilot scale, bench scale, and full size upw plants employed in the semiconductor and other industries. bacteria present in the polishing loop of the upw systems were enumerated by both plate counts and epifluorescence microscopy. assessment of bacterial presence in upw by epifluorescence microscopy (cyanotolyl tetrazolium chloride [ctc] and dapi [4',6'-diamidino-2-phenylindole] sta ... | 2002 | 11916667 |
| development and characterization of a green fluorescent protein-based bacterial biosensor for bioavailable toluene and related compounds. | a green fluorescent protein-based pseudomonas fluorescens strain a506 biosensor was constructed and characterized for its potential to measure benzene, toluene, ethylbenzene, and related compounds in aqueous solutions. the biosensor is based on a plasmid carrying the toluene-benzene utilization (tbu) pathway transcriptional activator tbut from ralstonia pickettii pko1 and a transcriptional fusion of its promoter ptbua1 with a promoterless gfp gene on a broad-host-range promoter probe vector. tbu ... | 2002 | 11916719 |
| the hydrogen-sensing apparatus in ralstonia eutropha. | molecular hydrogen is widely used by microorganisms as a source of energy. one of the best studied aerobic hydrogen oxidizers, the beta-proteobacterium ralstonia eutropha (formerly alcaligenes eutrophus), harbors two distinct [nife]-hydrogenases which catalyze the heterolytic cleavage of h2 into 2h+ and 2e-. the genes encoding the hydrogenase subunits are arranged in two large operons together with accessory and regulatory genes involved in hydrogenase biosynthesis. both operons are transcribed ... | 2002 | 11931556 |
| nitric oxide signaling and no dependent transcriptional control in bacterial denitrification by members of the fnr-crp regulator family. | bacterial denitrification transforms nitrate to dinitrogen. the process is expressed facultatively in response to environmental conditions. around 50 components make up the denitrification apparatus and its assembly pathways. we are beginning to understand how exogenous signals provided by oxygen and n oxides are processed for activating the underlying gene programs. key signals are provided by nitrate, nitric oxide, and a low oxygen tension. in the genus pseudomonas the nitrate signal is proces ... | 2002 | 11931559 |
| [chemical characterisation and serological activity of lipopolysaccharides of ralstonia solanacearum]. | lipopolysaccharides (lps) of 8 strains of ralstonia solanacearum (767, 4157, 5712, 7944, 7945, 7955, 8089 and 8110) characterized by different types of the structures of o-specific polysaccharide chains have been investigated. the elisa and elisa-inhibition methods were used to investigate the extent of antigenic activity of the presented lps with respect to the obtained polyclonal o-antisera to the above strains. when analyzing the results obtained the strains were divided into five serogroups ... | 2002 | 11944345 |
| cell-specific transgene expression from a widely transcribed promoter using cre/lox in mice. | mice carrying two or more transgenes are used frequently to evaluate oncogene interactions during carcinogenesis. however, neoplastic transformation typically results in reduced expression both of differentiation-specific genes and of transgenes that use their promoters. in contrast, the more widely expressed metallothionein (mt) gene remains expressed at a high level in certain neoplasms, including those developing in pancreas. we have developed a system to maintain high-level, tissue-specific ... | 2002 | 11948915 |
| a molybdenum-containing dehydrogenase catalyzing an unusual 2-hydroxylation of nicotinic acid. | an enzyme of ralstonia/ burkholderia strain dsm 6920 catalyzing the initial hydroxylation of 6-methylnicotinic acid at position 2 was purified to apparent homogeneity. it also catalyzed the unusual conversion of nicotinic acid to 2-hydroxynicotinic acid and was therefore designated as nicotinic acid dehydrogenase (ndh). native ndh had a molecular mass of 280 kda and was composed of subunits of 75, 30 and 16 kda. it contained molybdenum, iron, acid-labile sulfur and fad in a ratio of 1.6:7.3:8.0: ... | 2002 | 11956743 |
| autotrophic synthesis of polyhydroxyalkanoates by the bacteria ralstonia eutropha in the presence of carbon monoxide. | it has been found that the carbon monoxide (co)-resistant strain of the hydrogen bacteria ralstonia eutropha b5786 is able to synthesise polyhydroxyalkanoates (phas) in the presence of co under autotrophic conditions. this strain, grown on model gas mixtures containing 5-25% co (v/v), accumulates up to 70-75% (of absolutely dry matter) pha, without significant variation in the yield coefficient on hydrogen. no suppression of the activities of the key enzymes of pha synthesis ( beta-ketothiolase, ... | 2002 | 11956753 |
| community shifts in a seeded 3-chlorobenzoate degrading membrane biofilm reactor: indications for involvement of in situ horizontal transfer of the clc-element from inoculum to contaminant bacteria. | pseudomonas putida bn210, carrying the self- transferable clc-element encoding degradation of 3-chlorobenzoate on the chromosome, was used as inoculum in different membrane biofilm reactors treating 3-chlorobenzoate-contaminated model wastewater. analysis of the bacterial population in the effluent and in the biofilm showed the loss of bn210 beyond detection from the reactors and the appearance of several novel 3-chlorobenzoate mineralizing bacteria mainly belonging to the beta-proteobacteria. i ... | 2002 | 11972616 |
| comparative evaluation of the bd phoenix and vitek 2 automated instruments for identification of isolates of the burkholderia cepacia complex. | we evaluated two new automated identification systems, the bd phoenix (becton dickinson) and the vitek 2 (biomérieux), for identification of isolates of the burkholderia cepacia complex (bcc). the test sample included 42 isolates of the highly virulent and epidemic genomovar iii, 45 isolates of b. multivorans, and 47 isolates of other members of the bcc. rates of correct identification by the bd phoenix and vitek 2 were similar when all bcc isolates were considered (50 and 53%, respectively) but ... | 2002 | 11980954 |
| identification of novel sulfur-containing bacterial polyesters: biosynthesis of poly(3-hydroxy-s-propyl-omega-thioalkanoates) containing thioether linkages in the side chains. | this study describes the biosynthesis of novel sulfur-containing polyhydroxyalkanoates (phas), which consist exclusively of hydroxypropylthioalkanoic acid containing thioether groups in the side chains. in addition, the utilization of alkylthioalkanoic acids (=thia fatty acids) by various bacteria was investigated. based on feedings with propylthiooctanoic acid (pto) or propylthiohexanoic acid, the metabolically engineered pha-negative mutant phb(-)4 of ralstonia eutropha, which harbours plasmid ... | 2002 | 11988513 |
| distribution of type iii secretion gene clusters in burkholderia pseudomallei, b. thailandensis and b. mallei. | burkholderia pseudomallei, the causative agent of melioidosis, carries a cluster of genes closely related in organisation to the type iii secretion (tts) system gene clusters of the plant pathogens ralstonia solanacearum and xanthomonas spp. the tts gene cluster (tts1) is present only in b. pseudomallei and not in avirulent b. thailandensis. adjacent to the gene cluster encoding putative secreton structural proteins lie a number of open reading frames (orfs) encoding putative proteins with littl ... | 2002 | 11990489 |
| engineering of ralstonia eutropha for production of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) from fructose and solid-state properties of the copolymer. | recombinant ralstonia eutropha capable of producing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) copolymer [p(3hb-co-3hhx)] from fructose was engineered by introduction of genes for crotonyl-coa reductase (ccr) from streptomyces cinnamonensis (ccrsc) and for pha synthase and (r)-specific enoyl-coa hydratase from aeromonas caviae (phac-jac). in this recombinant strain, c6-acyl-coa intermediates were provided via beta-ketothiolase-mediated elongation of butyryl-coa, which was generated from croto ... | 2002 | 12005535 |
| the role of hydrogenases in the anaerobic microbiologically influenced corrosion of steels. | the direct electron transfer between 316 l stainless steel and the nad-dependent hydrogenase from ralstonia eutropha was studied by spectroelectrochemistry. the presence of hydrogenase and nad+ clearly increased the quantity of electricity, which was consumed during the electrolysis performed at potential lower than -0.70 v/sce. the involvement of hydrogenase in the cathodic depolarisation theory was discussed in the light of these results. | 2002 | 12009448 |
| the iron-containing superoxide dismutase of ralstonia metallidurans ch34. | the iron-containing superoxide dismutase (fe-sod) of ralstonia metallidurans ch34 was purified and characterised as a homodimer of 2 x 21500 da containing one iron atom per monomer and exhibiting all the characteristics of the prokaryotic fe-sods except for a higher isoelectric point. the protein was 2-fold overexpressed in the presence of selenite, zinc or paraquat. r. metallidurans ch34 was suggested to contain a gene encoding for a manganese-containing sod located in the inducible chromate re ... | 2002 | 12023089 |
| osmoregulated periplasmic glucans of the free-living photosynthetic bacterium rhodobacter sphaeroides. | the osmoregulated periplasmic glucans (opgs) produced by rhodobacter sphaeroides, a free-living organism, were isolated by trichloracetic acid treatment and gel permeation chromatography. compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance. r. sphaeroides predominantly synthesizes a cyclic glucan containing 18 glucose residues that can be substituted by one to seven succinyl esters residues ... | 2002 | 12027884 |
| phylogeny and functional expression of ribulose 1,5-bisphosphate carboxylase/oxygenase from the autotrophic ammonia-oxidizing bacterium nitrosospira sp. isolate 40ki. | the autotrophic ammonia-oxidizing bacteria (aob), which play an important role in the global nitrogen cycle, assimilate co(2) by using ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco). here we describe the first detailed study of rubisco (cbb) genes and proteins from the aob. the cbbls genes from nitrosospira sp. isolate 40ki were cloned and sequenced. partial sequences of the rubisco large subunit (cbbl) from 13 other aob belonging to the beta and gamma subgroups of the class proteobac ... | 2002 | 11751824 |
| 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 ... | 2002 | 11751829 |
| 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 ... | 2002 | 11772621 |
| 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 ... | 2002 | 11772636 |
| monitoring of ralstonia eutropha kt1 in groundwater in an experimental bioaugmentation field by in situ pcr. | ralstonia eutropha kt1, which degrades trichloroethylene, was injected into the aquifer after activation with toluene, and then the number of bacteria was monitored by in situ pcr targeting the phenol hydroxylase gene and by fluorescent in situ hybridization (fish) targeting 16s rrna. before injection of the bacterial suspension, the total concentration of bacteria in the groundwater was approximately 3 x 10(5) cells/ml and the amount of ralstonia and bacteria carrying the phenol hydroxylase gen ... | 2002 | 11772654 |
| 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 ... | 2002 | 11741844 |
| characterization of unusual bacteria isolated from respiratory secretions of cystic fibrosis patients and description of inquilinus limosus gen. nov., sp. nov. | using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16s ribosomal dna sequencing, and dna-dna hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (cf) patients. our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from cf patients. these taxa include acinetobacter sp., bordetella hinzii, burkholderia fungorum, comamonas testost ... | 2002 | 12037065 |
| opportunistic colonization of ralstonia solanacearum-infected plants by acinetobacter sp. and its natural competence development. | the behavior of the soil bacterium acinetobacter sp. bd413 was monitored in ralstonia solanacearum-infected and non-infected tomato plants after direct injection into the stem or natural infection by roots. in healthy plants, acinetobacter sp. bd413 failed to colonize plant tissue. in plants infected simultaneously by the pathogen r. solanacearum,the acinetobacter population increased linearly to about 3.1 x 10(7) cells per gram plant material and was maintained at a high level until the death o ... | 2002 | 12037607 |
| in vitro evolution of a polyhydroxybutyrate synthase by intragenic suppression-type mutagenesis. | in vitro evolution was applied to obtain highly active mutants of ralstonia eutropha polyester synthase (phbc(re)), which is a key enzyme catalyzing the formation of polyhydroxybutyrate (phb) from (r)-3-hydroxybutyryl-coa (3hb-coa). to search for beneficial mutations for activity improvement of this enzyme, we have conducted multi-step mutations, including activity loss and intragenic suppression-type activity reversion. among 259 revertants, triple mutant e11s12 was obtained as the most active ... | 2002 | 12038975 |
| genetic dissection of ralstonia solanacearum hrp gene cluster reveals that the hrpv and hrpx proteins are required for hrp pilus assembly. | in both plant and mammalian gram-negative pathogenic bacteria, type iii secretion systems (ttsss) play a crucial role in interactions with the host. all these systems share conserved proteins (called hrc in plant pathogens), but each bacterium also produces a variable number of additional type iii proteins either unique or with counterparts only in a limited number of related systems. in order to investigate the role of the different proteins encoded by the hrp gene cluster of the phytopathogeni ... | 2002 | 12046592 |
| genetic and biochemical characterization of a 2,4,6-trichlorophenol degradation pathway in ralstonia eutropha jmp134. | ralstonia eutropha jmp134 can grow on several chlorinated aromatic pollutants, including 2,4-dichlorophenoxyacetate and 2,4,6-trichlorophenol (2,4,6-tcp). although a 2,4,6-tcp degradation pathway in jmp134 has been proposed, the enzymes and genes responsible for 2,4,6-tcp degradation have not been characterized. in this study, we found that 2,4,6-tcp degradation by jmp134 was inducible by 2,4,6-tcp and subject to catabolic repression by glutamate. we detected 2,4,6-tcp-degrading activities in jm ... | 2002 | 12057943 |
| substrate specificity of nickel/cobalt permeases: insights from mutants altered in transmembrane domains i and ii. | hoxn, a high-affinity, nickel-specific permease of ralstonia eutropha h16, and nhlf, a nickel/cobalt permease of rhodococcus rhodochrous j1, are structurally related members of the nickel/cobalt transporter (nicot) family. these transporters have an eight-helix structure and are characterized by highly conserved segments with polar or charged amino acid residues in transmembrane domains (tmds) ii, iii, v, and vi. two histidine residues in a ni2+ binding motif, the signature sequence of nicots, i ... | 2002 | 12057951 |
| activation of the pseudomonas aeruginosa type iii secretion system requires an intact pyruvate dehydrogenase aceab operon. | pseudomonas aeruginosa clinical cystic fibrosis isolate cha was mutagenized with tn5tc to identify new genes involved in type iii secretion system (ttss)-dependent cytotoxicity toward human polymorphonuclear neutrophils. among 25 mutants affected in ttss function, 14 contained the insertion at different positions in the aceab operon encoding the pdh-e1 and -e2 subunits of pyruvate dehydrogenase. in pdh mutants, no transcriptional activation of ttss genes in response to calcium depletion occurred ... | 2002 | 12065547 |
| tfdd(ii), one of the two chloromuconate cycloisomerases of ralstonia eutropha jmp134 (pjp4), cannot efficiently convert 2-chloro- cis, cis-muconate to trans-dienelactone to allow growth on 3-chlorobenzoate. | ralstonia eutropha jmp134 (pjp4) harbors two functional gene clusters for the degradation of chlorocatechols, i.e. tfdcdef (in short: tfd (i)) and tfdd (ii) c (ii) e (ii) f (ii) (in short: tfd (ii)), which are both present on the catabolic plasmid pjp4. in this study, we compared the function of both gene clusters for degradation of chlorocatechols by constructing isolated and hybrid tfd (i)- tfd (ii) clusters on plasmids in r. eutropha, by activity assays of tfd enzymes, and by hplc/ms of indiv ... | 2002 | 12070765 |
| heterotrophic bacteria growing in association with methylococcus capsulatus (bath) in a single cell protein production process. | the methanotrophic bacterium methylococcus capsulatus (bath) grows on pure methane. however, in a single cell protein production process using natural gas as methane source, a bacterial consortium is necessary to support growth over longer periods in continuous cultures. in different bioreactors of norferm danmark a/s, three bacteria consistently invaded m. capsulatus cultures growing under semi-sterile conditions in continuous culture. these bacteria have now been identified as a not yet descri ... | 2002 | 12073128 |
| the copy number of the catabolic plasmid pjp4 affects growth of ralstonia eutropha jmp134 (pjp4) on 3-chlorobenzoate. | ralstonia eutropha jmp134 (pjp4) grows on 3-chlorobenzoate (3-cb) or 2,4-dichlorophenoxyacetate (2,4-d). the copy number of chlorocatechol genes has been observed to be important for allowing growth of bacterial strains on chloroaromatic compounds. despite the fact that two functional chlorocatechol degradation tfd gene clusters are harbored on plasmid pjp4, a single copy of the region comprising all tfd genes in strain jmp134-f was insufficient to allow growth on 3-cb, whereas growth on 2,4-d w ... | 2002 | 12076793 |
| in situ transfer of antibiotic resistance genes from transgenic (transplastomic) tobacco plants to bacteria. | interkingdom gene transfer is limited by a combination of physical, biological, and genetic barriers. the results of greenhouse experiments involving transplastomic plants (genetically engineered chloroplast genomes) cocolonized by pathogenic and opportunistic soil bacteria demonstrated that these barriers could be eliminated. the acinetobacter sp. strain bd413, which is outfitted with homologous sequences to chloroplastic genes, coinfected a transplastomic tobacco plant with ralstonia solanacea ... | 2002 | 12089013 |
| enrichment double-antibody sandwich indirect enzyme-linked immunosorbent assay that uses a specific monoclonal antibody for sensitive detection of ralstonia solanacearum in asymptomatic potato tubers. | sensitive and specific routine detection of ralstonia solanacearum in symptomless potato tubers was achieved by efficient enrichment followed by a reliable double-antibody sandwich indirect enzyme-linked immunosorbent assay based on the specific monoclonal antibody 8b-ivia. this monoclonal antibody reacted with 168 typical r. solanacearum strains and did not recognize 174 other pathogenic or unidentified bacteria isolated from potato. the optimized protocol included an initial enrichment step co ... | 2002 | 12089053 |
| ralstonia pickettii traced in blood culture bottles. | over a 9-month period, 14 strains of ralstonia pickettii were isolated from various biological samples inoculated in a blood culture medium. molecular epidemiological investigation confirmed the relatedness of the strains. the source of the contamination proved to be the blood culture bottle caps. | 2002 | 12089303 |
| characterization of polychlorinated biphenyl-degrading bacteria isolated from contaminated sites in czechia. | biphenyl-utilizing polychlorinated biphenyls (pcb)-degrading bacteria were isolated from sites highly contaminated by pcbs, and their degradation abilities were determined using gc for typical commercial pcb mixtures (delor 103 and delor 106). out of twelve strains which utilized biphenyl as a sole source of carbon and energy, strains pseudomonas alcaligenes kp2 and p. fluorescens kp12, characterized by the biolog identification system and the neferm test, were shown to significantly co-metaboli ... | 2002 | 12094733 |
| 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 ... | 2002 | 12095436 |
| enzymatic hydrolysis of bacterial poly(3-hydroxybutyrate-co-3-hydroxypropionate)s by poly(3-hydroxyalkanoate) depolymerase from acidovorax sp. tp4. | enzymatic degradability has been investigated for a series of bacterial poly(3-hydroxybutyrate-co-3-hydroxypropionate)s (p(3hb-co-3hp)s) with 3-hydroxypropionate (3hp) unit contents from 11 to 86 mol % as well as poly(3-hydroxybutyrate) (p(3hb)) and chemosynthesized poly(3-hydroxypropionate) (p(3hp)). the behavior of degradation by two types of extracellular poly(3-hydroxyalkanoate) (pha) depolymerases purified from ralstonia pikettii t1 and acidovorax sp. tp4, defined respectively as pha depoly ... | 2002 | 12099829 |
| importance of different tfd genes for degradation of chloroaromatics by ralstonia eutropha jmp134. | the tfdc(i)d(i)e(i)f(i,) and tfdd(ii)c(ii)e(ii)f(ii) gene modules of plasmid pjp4 of ralstonia eutropha jmp134 encode complete sets of functional enzymes for the transformation of chlorocatechols into 3-oxoadipate, which are all expressed during growth on 2,4-dichlorophenoxyacetate (2,4-d). however, activity of tfd(i)-encoded enzymes was usually higher than that of tfd(ii)-encoded enzymes, both in the wild-type strain grown on 2,4-d and in 3-chlorobenzoate-grown derivatives harboring only one tf ... | 2002 | 12107121 |
| method for qualifying microbial removal performance of 0.1 micron rated filters. part iv: retention of hydrogenophaga pseudoflava (atcc 700892) and ralstonia pickettii (atcc 700591) by 0.2 and 0.22 micron rated filters. | ralstonia pickettii has emerged as a bioburden microorganism of considerable importance in pharmaceutical processes utilizing conventional 0.2 or 0.22 micron rated "sterilizing grade" filters. in this article, we re-evaluated and studied the retention efficiencies of 0.2 micron rated nylon 6.6 and 0.22 microns rated modified polyvinylidene fluoride (pvdf) filters for hydrogenophaga pseudoflava (atcc 700892) and r. pickettii (atcc 700591). out of a total of forty-four 0.2/0.22 micron rated filter ... | 2002 | 12109335 |
| the malate dehydrogenase of ralstonia eutropha and functionality of the c(3)/c(4) metabolism in a tn5-induced mdh mutant. | the tn5-induced mutant vg12 of ralstonia eutropha hf39, which was isolated in this study, revealed an interesting phenotype: it grew on fructose and pyruvate as well as autotrophically like the wild-type, whereas growth on tricarboxylic acid intermediates and glyoxylic acid was reduced, and no growth occurred if acetate, propionate or levulinate were provided as carbon source. tn5 was mapped in a gene encoding an nad(h)-dependent malate dehydrogenase (mdh), and mdh activity was strongly diminish ... | 2002 | 12113928 |
| genetics and control of co(2) assimilation in the chemoautotroph ralstonia eutropha. | the nutritional versatility of facultative autotrophs requires efficient overall control of their metabolism. most of these organisms are proteobacteria that assimilate co(2) via the highly energy-demanding calvin-benson-bassham reductive pentose-phosphate cycle. the enzymes of the cycle are encoded by cbb genes organized in cbb operons differing in size and composition, although conserved features are apparent. transcription of the operons, which may form regulons, is strictly controlled, being ... | 2002 | 12115053 |
| biochemical and enzymological properties of the polyhydroxybutyrate synthase from the extremely halophilic archaeon strain 56. | some members of the archaebacterial family halobacteriaceae have been determined to accumulate polyhydroxyalkanoate (pha) and poly(3-hydroxybutyrate) (phb). the extremely halophilic archaebacterium strain 56 is capable of accumulating large amounts of phb. since measurements of enzyme activities related to archaebacterial phb biosynthesis have never been achieved, we investigated the enzymology of phb biosynthesis in strain 56. crude extracts of strain 56 cultivated under accumulating conditions ... | 2002 | 12139978 |
| molecular breeding of transgenic rice plants expressing a bacterial chlorocatechol dioxygenase gene. | the cbna gene encoding the chlorocatechol dioxygenase gene from ralstonia eutropha nh9 was introduced into rice plants. the cbna gene was expressed in transgenic rice plants under the control of a modified cauliflower mosaic virus 35s promoter. western blot analysis using anti-cbna protein indicated that the cbna gene was expressed in leaf tissue, roots, culms, and seeds. transgenic rice calluses expressing the cbna gene converted 3-chlorocatechol to 2-chloromucote efficiently. growth and morpho ... | 2002 | 12147507 |
| comparative genomic analysis of plant-associated bacteria. | this review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. these are the genomes of agrobacterium tumefaciens, mesorhizobium loti, sinorhizobium meliloti, xanthomonas campestris pv campestris, xanthomonas axonopodis pv citri, xylella fastidiosa, and ralstonia solanacearum. genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. despite the recognized importance of the type iii secretion sy ... | 2002 | 12147758 |
| production, properties and specificity of a new bacterial l-fucose- and d-arabinose-binding lectin of the plant aggressive pathogen ralstonia solanacearum, and its comparison to related plant and microbial lectins. | the worldwide distributed plant aggressive pathogen ralstonia solanacearum, which causes lethal wilt in many agricultural crops, produces a potent l-fucose-binding lectin (rsl) exhibiting sugar specificity similar to that of pa-iil of the human aggressive opportunistic pathogen pseudomonas aeruginosa. both lectins show l-fucose > l-galactose > d-arabinose > d-mannose specificity, but the affinities of rsl to these sugars are substantially lower. unlike ulex europaeus anti-h lectin, but like pa-i ... | 2002 | 12153735 |
| survival and nutritional requirements of three bacteria isolated from ultrapure water. | bacteria isolated previously from ultrapure water (upw) systems were examined for their ability to survive in upw, with the ultimate goal of elucidating potential carbon and energy sources for the bacteria. two strains of ralstonia pickettii isolated from different areas within the upw system (pretreatment and polishing loop, and referred to as strains 3a1 and mf254a, respectively) and a strain of bradyrhizobium sp. were compared to increase our understanding of the fundamental behavior of bacte ... | 2002 | 12161774 |
| characterization of bacterial consortia capable of degrading 4-chlorobenzoate and 4-bromobenzoate under denitrifying conditions. | 4-chlorobenzoate and 4-bromobenzoate were readily degraded in denitrifying enrichment cultures established with river sediment, estuarine sediment or agricultural soil as inoculum. stable denitrifying consortia were obtained and maintained by serial dilution and repeated feeding of substrates. microbial community analyses were performed to characterize the 4-chlorobenzoate and 4-bromobenzoate degrading consortia with terminal restriction fragment length polymorphism (t-rflp) and cloning of 16s r ... | 2002 | 12167535 |
| regulation of phasin expression and polyhydroxyalkanoate (pha) granule formation in ralstonia eutropha h16. | regulation of expression of the phasin phap, which is the major protein at the surface of polyhydroxyalkanoate (pha) granules in ralstonia eutropha h16, was studied and analysed at the molecular level. the regulation of phap expression is achieved by an autoregulated repressor, which is encoded by phar in r. eutropha. the occurrence of phar homologues and the organization of phar genes was analysed in detail in 29 different bacteria. three kinds of molecule to which phar binds were identified in ... | 2002 | 12177335 |
| characterization of copolymer hydroxybutyrate/hydroxyvalerate from saponified vernonia, soybean, and "spent" frying oils. | poly(beta-hydroxyalkanoate)s (phas) were biosynthesized by ralstonia eutropha (formerly known as alcaligenes eutrophus) by using saponified soybean, vernonia, and "spent" frying oils. these phas were isolated and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tofms), gas chromatography/mass spectrometry (gc/ms), proton nuclear magnetic resonance spectrometry (1h nmr), and 2-dimensional homonuclear (1h-1h) correlation spectroscopy (cosy). the ... | 2002 | 12180688 |
| identification of bacteria in drinking and purified water during the monitoring of a typical water purification system. | a typical purification system that provides purified water which meets ionic and organic chemical standards, must be protected from microbial proliferation to minimize cross-contamination for use in cleaning and preparations in pharmaceutical industries and in health environments. | 2002 | 12182763 |
| characterization of four olive-mill-wastewater indigenous bacterial strains capable of aerobically degrading hydroxylated and methoxylated monocyclic aromatic compounds. | seven aerobic bacterial strains capable of degrading several of the monocyclic aromatic compounds occurring in the phenolic fraction of olive-mill wastewaters (omws) were isolated from an italian omw. the results of the 16s rdna restriction analysis evidenced that these strains are distributed among four different groups. one strain of each group was taxonomically characterized by sequencing the amplified 16s rdna, and the four strains were assigned to the genera comamonas (strain av1a), ralston ... | 2002 | 12189422 |
| [the study of bacterial glycopolymers using laser spectroscopy]. | a possibility has been demonstrated to use laser spectroscopy of bacterial glycopolymers by means of measurement of their water solutions fluorescence. comparative investigations of native lipopolysaccharide (lps) ralstonia solanacearum and its structure components permits a supposition to be made that the lps total spectrum is a result of superposition of the spectrum of o-specific polysaccharide and core oligosaccharide as well as core oligosaccharide and lipid a. the lps spectrum maximum shif ... | 2002 | 12190019 |
| carbonic anhydrase is essential for growth of ralstonia eutropha at ambient co(2) concentrations. | mutant strain 25-1 of the facultative chemoautotroph ralstonia eutropha h16 had previously been shown to exhibit an obligately high-co(2)-requiring (hcr) phenotype. although the requirement varied with the carbon and energy sources utilized, none of these conditions allowed growth at the air concentration of co(2). in the present study, a gene designated can and encoding a beta-carbonic anhydrase (ca) was identified as the site altered in strain 25-1. the mutation caused a replacement of the hig ... | 2002 | 12193617 |
| biotransformation of eugenol to ferulic acid by a recombinant strain of ralstonia eutropha h16. | the gene loci ehyab, cala, and calb, encoding eugenol hydroxylase, coniferyl alcohol dehydrogenase, and coniferyl aldehyde dehydrogenase, respectively, which are involved in the first steps of eugenol catabolism in pseudomonas sp. strain hr199, were amplified by pcr and combined to construct a catabolic gene cassette. this gene cassette was cloned in the newly designed broad-host-range vector pbbr1-jo2 (pbbr1-jo2ehyabcalacalb) and transferred to ralstonia eutropha h16. a recombinant strain of r. ... | 2002 | 12200281 |
| the h(2) sensor of ralstonia eutropha: biochemical and spectroscopic analysis of mutant proteins modified at a conserved glutamine residue close to the [nife] active site. | [nife] hydrogenases contain a highly conserved histidine residue close to the [nife] active site which is altered by a glutamine residue in the h(2)-sensing [nife] hydrogenases. in this study, we exchanged the respective glutamine residue of the h(2) sensor (rh) of ralstonia eutropha, q67 of the rh large subunit hoxc, by histidine, asparagine and glutamate. the replacement by histidine and asparagine resulted in slightly unstable rh proteins which were hardly affected in their regulatory and enz ... | 2002 | 12203028 |
| enzymatic hydrolysis of chemosynthesized atactic poly(3-hydroxybutyrate) by poly(3-hydroxyalkanoate) depolymerase from acidovorax sp. tp4 and ralstonia pickettii t1. | the enzymatic degradability of chemosynthesized atactic poly([r,s]-3-hydroxybutyrate) [a-p(3hb)] by two types of extracellular poly(3-hydroxyalkanoate) (pha) depolymerases purified from ralstonia pickettii t1 (phaz(ral)) and acidovorax sp. tp4 (phaz(aci)), defined respectively as pha depolymerase types i and ii according to the position of the lipase box in the catalytic domain, were studied. the enzymatic degradation of a-p(3hb) by phaz(aci) depolymerase was confirmed from the results of weight ... | 2002 | 12217032 |
| metabolism of dichloromethylcatechols as central intermediates in the degradation of dichlorotoluenes by ralstonia sp. strain ps12. | ralstonia sp. strain ps12 is able to use 2,4-, 2,5-, and 3,4-dichlorotoluene as growth substrates. dichloromethylcatechols are central intermediates that are formed by teca tetrachlorobenzene dioxygenase-mediated activation at two adjacent unsubstituted carbon atoms followed by tecb chlorobenzene dihydrodiol dehydrogenase-catalyzed rearomatization and then are channeled into a chlorocatechol ortho cleavage pathway involving a chlorocatechol 1,2-dioxygenase, chloromuconate cycloisomerase, and die ... | 2002 | 12218011 |
| formation of protoanemonin from 2-chloro-cis,cis-muconate by the combined action of muconate cycloisomerase and muconolactone isomerase. | muconate cycloisomerases are known to catalyze the reversible conversion of 2-chloro-cis,cis-muconate by 1,4- and 3,6-cycloisomerization into (4s)-(+)-2-chloro- and (4r/5s)-(+)-5-chloromuconolactone. 2-chloromuconolactone is transformed by muconolactone isomerase with concomitant dechlorination and decarboxylation into the antibiotic protoanemonin. the low k(cat) for this compound compared to that for 5-chloromuconolactone suggests that protoanemonin formation is of minor importance. however, si ... | 2002 | 12218027 |
| evaluation of procedures for reliable pcr detection of ralstonia solanacearum in common natural substrates. | several procedures were compared for reliable pcr detection of ralstonia solanacearum in common substrates (plant, seed, water and soil). in order to prevent the inhibition of pcr by substances contained in crude extracts, numerous dna extraction procedures as well as additives to buffers or pcr mixtures were checked. our results showed that the efficiency of these methods or compounds depended greatly upon the nature of the sample. consequently, preparation of samples prior to pcr depended upon ... | 2002 | 12223295 |
| amplification of rna by nasba allows direct detection of viable cells of ralstonia solanacearum in potato. | the objective of this study was to develop a nucleic acid sequence based amplification (nasba) assay, targeting 16s rrna sequences, for direct detection of viable cells of ralstonia solanacearum, the causal organism of bacterial wilt. the presence of intact 16s rrna is considered to be a useful indicator for viability, as a rapid degradation of this target molecule is found upon cell death. | 2002 | 12234348 |
| an arsenic(iii)-oxidizing bacterial population: selection, characterization, and performance in reactors. | to select an autotrophic arsenic(iii)-oxidizing population, named caso1, and to evaluate the performance of the selected bacteria in reactors. | 2002 | 12234349 |
| heca, a member of a class of adhesins produced by diverse pathogenic bacteria, contributes to the attachment, aggregation, epidermal cell killing, and virulence phenotypes of erwinia chrysanthemi ec16 on nicotiana clevelandii seedlings. | erwinia chrysanthemi is representative of a broad class of bacterial pathogens that are capable of inducing necrosis in plants. the e. chrysanthemi ec16 heca gene predicts a 3,850-aa member of the bordetella pertussis filamentous hemagglutinin family of adhesins. a hecatn7 mutant was reduced in virulence on nicotiana clevelandii seedlings after inoculation without wounding. epifluorescence and confocal laser-scanning microscopy observations of heca and wild-type cells expressing the green fluore ... | 2002 | 12271135 |
| microbial origin of glutamate, hibernation and tissue trauma: an in vivo microdialysis study. | using quantitative microdialysis in hibernating arctic ground squirrels (ags), striatal glutamate concentrations ([glu](dia)) progressively increased to approximately 200 microm after 3 days of microdialysis in euthermic but not hibernating ground squirrels. initially, the progressive increase in [glu](dia) was thought to be related to greater tissue response in euthermic animals. alternatively, given the vastly different body temperatures between the two groups (37 vs. 3 degrees c), glutamate m ... | 2002 | 12323415 |
| carbon and hydrogen stable isotope fractionation during aerobic bacterial degradation of aromatic hydrocarbons. | 13c/(12)c and d/h stable isotope fractionation during aerobic degradation was determined for pseudomonas putida strain mt-2, pseudomonas putida strain f1, ralstonia pickettii strain pko1, and pseudomonas putida strain ncib 9816 grown with toluene, xylenes, and naphthalene. different types of initial reactions used by the respective bacterial strains could be linked with certain extents of stable isotope fractionation during substrate degradation. | 2002 | 12324375 |
| use of 16s rrna gene sequencing for identification of nonfermenting gram-negative bacilli recovered from patients attending a single cystic fibrosis center. | during 1999, we used partial 16s rrna gene sequencing for the prospective identification of atypical nonfermenting gram-negative bacilli isolated from patients attending our cystic fibrosis center. of 1,093 isolates of nonfermenting gram-negative bacilli recovered from 148 patients, 46 (4.2%) gave problematic results with conventional phenotypic tests. these 46 isolates were genotypically identified as pseudomonas aeruginosa (19 isolates, 12 patients), achromobacter xylosoxidans (10 isolates, 8 ... | 2002 | 12354883 |
| cloning of the class d beta-lactamase gene from burkholderia pseudomallei and studies on its expression in ceftazidime-susceptible and -resistant strains. | ceftazidime is the antibiotic of choice for the treatment of melioidosis. ceftazidime-resistant burkholderia pseudomallei have been identified and beta-lactamase production implicated in resistance. in this study, 25 strains of b. pseudomallei (15 clinical and 10 environmental strains) were examined for their ability to yield mutants that overexpress beta-lactamase. ceftazidime-resistant mutants were selected readily at high frequency and displayed four- to eight-fold increases in the mics of ce ... | 2002 | 12356787 |
| functional analysis by site-directed mutagenesis of the nad(+)-reducing hydrogenase from ralstonia eutropha. | the tetrameric cytoplasmic [nife] hydrogenase (sh) of ralstonia eutropha couples the oxidation of hydrogen to the reduction of nad(+) under aerobic conditions. in the catalytic subunit hoxh, all six conserved motifs surrounding the [nife] site are present. five of these motifs were altered by site-directed mutagenesis in order to dissect the molecular mechanism of hydrogen activation. based on phenotypic characterizations, 27 mutants were grouped into four different classes. mutants of the major ... | 2002 | 12399498 |
| ralstonia solanacearum requires type 4 pili to adhere to multiple surfaces and for natural transformation and virulence. | as reported previously for ralstonia solanacearum strain gmi1000, wild-type strains aw1 and k60 were shown to produce hrp pili. aw1 and k60 mutants lacking hrp pili still exhibited twitching motility, which requires type 4 pili (tfp), and electron microscopy revealed that they still made flexuous polar pili. twitching-positive cells had an extracellular 17 kda protein that was associated with piliation, and an internal 43-amino-acid sequence of this protein was typical of type 4 pilins. this ami ... | 2002 | 12406219 |
| characterization of the adaptive response to trichloroethylene-mediated stresses in ralstonia pickettii pko1. | in ralstonia pickettii pko1, a denitrifying toluene oxidizer that carries a toluene-3-monooxygenase (t3mo) pathway, the biodegradation of toluene and trichloroethylene (tce) by the organism is induced by tce at high concentrations. in this study, the effect of tce preexposure was studied in the context of bacterial protective response to tce-mediated toxicity in this organism. the results of tce degradation experiments showed that cells induced by tce at 110 mg/liter were more tolerant to tce-me ... | 2002 | 12406709 |
| a novel class of self-sufficient cytochrome p450 monooxygenases in prokaryotes. | the bacillus cytochrome p450 bm3 integrates an entire p450 system in one polypeptide and represents a convenient prokaryotic model for microsomal p450s. this self-sufficient class ii p450 is also present in actinomycetes and fungi. by genome analysis we have identified additional homologues in the pathogenic species bacillus anthracis and bacillus cereus, and in ralstonia metallidurans. this analysis also revealed a novel class of putative self-sufficient p450s, p450 pfor, comprising a class i p ... | 2002 | 12419614 |
| diversity of transconjugants that acquired plasmid pjp4 or pemt1 after inoculation of a donor strain in the a- and b-horizon of an agricultural soil and description of burkholderia hospita sp. nov. and burkholderia terricola sp. nov. | we examined the diversity of transconjugants that acquired the catabolic plasmids pjp4 or pemt1, which encode degradation of 2,4-dichlorophenoxyacetic acid (2,4-d), in microcosms with agricultural soil inoculated with a donor strain (dejonghe, w., goris, j., el fantroussi, s., höfte, m., de vos, p., verstraete, w., and top, e. m. appl. environ. microbiol. 2000, p. 3297-3304). using repetitive element pcr fingerprinting, eight different rep-clusters and six separate isolates could be discriminate ... | 2002 | 12421072 |
| change of surface structure of poly(3-hydroxybutyrate) film upon enzymatic hydrolysis by phb depolymerase. | the change in the surface structure of poly[(r)-3-hydroxybutyrate] [phb] films upon the enzymatic hydrolysis was analyzed by attenuated total reflection infrared [atr/ir] spectrometry. as enzymes, phb depolymerases isolated from ralstonia pickettii t1 and pseudomonas stutzeri were used. by curve decomposition of the carbonyl stretching band of atr/ir spectra, the change in the surface crystallinity of phb films by exposure to buffer containing 0, 1, and 4 microg of phb depolymerases was estimate ... | 2002 | 12425671 |
| novel insights into the interplay between peripheral reactions encoded by xyl genes and the chlorocatechol pathway encoded by tfd genes for the degradation of chlorobenzoates by ralstonia eutropha jmp134. | many bacteria can grow on chloroaromatic pollutants because they can transform them into chlorocatechols, which are further degraded by enzymes of a specialized ortho-cleavage pathway. ralstonia eutropha jmp134 is able to grow on 3-chlorobenzoate by using two pjp4-encoded, ortho-cleavage chlorocatechol degradation gene clusters (tfdc(i)d(i)e(i)f(i) and tfdd(ii)c(ii)e(ii)f(ii)). very little is known about the acquisition of new catabolic genes encoding enzymes that lead to the formation of chloro ... | 2002 | 12427935 |
| carbazolequinone induction of caspase-dependent cell death in src-overexpressing cells. | we previously reported that rsv-transformed quail neuroretina cells (qnr-ts68) were highly resistant to apoptosis provoked by serum withdrawal, and that this property was due to v-src kinase activity. the present study investigates the cytotoxic effect and the functional mechanism of carbazolequinone-mediated cell death in this system. qnr-ts68 cells were subjected to carbazolequinone treatment and both growth inhibition and cell death induction were examined using formazan assays. cell death me ... | 2002 | 12429350 |
| is the contribution of bacteria to terrestrial carbon budget greatly underestimated? | some commonly found species of soil bacteria use low molecular weight organic acids as their sole source of carbon and energy. this study shows that acids such as citrate and oxalate (produced in large amounts by fungi and plants) can rapidly be consumed by these bacteria. two strains, ralstonia eutropha and xanthobacter autotrophicus, were cultured on acetate- and citrate-rich media. the resulting co2 and/or hco3- reacted with calcium ions to precipitate two polymorphs of calcium carbonate (cac ... | 2002 | 12435038 |
| popp1, a new member of the yopj/avrrxv family of type iii effector proteins, acts as a host-specificity factor and modulates aggressiveness of ralstonia solanacearum. | a functional analysis of an 11-kb-long region of the genome of the plant-pathogenic bacterium ralstonia solanacearum, previously identified as an alternative codon usage region (acur), reveals that it was probably acquired through horizontal gene transfer. this acur encodes an insertion sequence and eight potential proteins, one of which is partially homologous with a host-specificity factor from a plant-pathogenic erwinia sp., and another, popp1, which is homologous to members of the yopj/avrrx ... | 2002 | 12437304 |
| chemotaxis of a ralstonia sp. sj98 toward co-metabolizable nitroaromatic compounds. | we have earlier reported chemotaxis of a gram-negative, motile ralstonia sp. sj98 towards p-nitrophenol (pnp), 4-nitrocatechol (nc), o-nitrobenzoate (onb), p-nitrobenzoate (pnb), and 3-methyl-4-nitrophenol (mnp) that also served as sole source of carbon and energy to the strain [s.k. samanta, b. bhushan, a. chauhan, r.k. jain, biochem. biophy. res. commun. 269 (2000) 117; b. bhushan, s.k. samanta, a. chauhan, a.k. chakraborti, r.k. jain, biochem. biophy. res. commun. 275 (2000) 129]. in this pap ... | 2002 | 12445815 |
| a novel high-cell-density protein expression system based on ralstonia eutropha. | we describe the development of a novel protein expression system based on the industrial fermentation organism ralstonia eutropha (formerly known as alcaligenes eutrophus) ncimb 40124. this new system overcomes some of the shortcomings of traditional escherichia coli-based protein expression systems, particularly the propensity of such systems to form inclusion bodies during high-level expression. using a proteomics approach, we identified promoters that can be induced by simple process paramete ... | 2002 | 12450812 |
| green technology for conversion of food scraps to biodegradable thermoplastic polyhydroxyalkanoates. | a new technology is developed and demonstrated that couples anaerobic digestion of food scraps with production of biodegradable thermoplastics, polyhydroxyalkanoates (phas). the food wastes were digested in an anaerobic reactor producing four major organic acids. the concentrations of acetic, propionic, butyric, and lactic acids reached 5.5, 1.8, 27.4, and 32.7 g/l, respectively. the fermentative acids were transferred through membranes via molecule diffusion into an air-bubbling reactor where t ... | 2002 | 12521183 |
| new genes involved in chromate resistance in ralstonia metallidurans strain ch34. | chromate resistance in ralstonia metallidurans ch34 is based on chromate efflux catalyzed by chra efflux pumps. the bacterium harbors two chromate resistance determinants, the previously known chr(1) on plasmid pmol28 (genes chri, chrb(1), chra(1), chrc, chre, chrf(1)) and chr(2) on the chromosome (genes chrb(2), chra(2), chrf(2)). deletion of the genes chri, chrc, chra(2), chrb(2) and chrf(2) influenced chromate resistance and transcription from a chrbp(1) ::lacz fusion. deletion of the plasmid ... | 2002 | 12471500 |
| type iv pili are not specifically required for contact dependent translocation of exoenzymes by pseudomonas aeruginosa. | the type iii secretion system (ttss) of the opportunistic pathogen pseudomonas aeruginosa enables the bacterium to deliver exoenzymes directly into the eukaryotic cell. in this study we have investigated the role of key factors involved in this process. we could demonstrate that the translocators popb, popd and pcrv are absolutely required for delivery of exoenzyme s into host cells. by analyzing different tfp (type iv pili) mutants we could establish a correlation between the frequency of bacte ... | 2002 | 12495673 |
| cloning, sequencing, and overexpression in escherichia coli of a phenylserine dehydratase gene from ralstonia pickettii ps22. | the structural gene coding for phenylserine dehydratase from ralstonia pickettii ps22 was cloned into escherichia coli cells, and the nucleotide sequence was identified. the predicted amino acid sequence had high sequence similarity to biodegradative and biosynthetic threonine dehydratases from e. coli and serine dehydratase from human liver. transformed e. coli cells overproduced phenylserine dehydratase, and the recombinant enzyme was purified to homogeneity with a high yield and characterized ... | 2002 | 12596884 |
| ralstonia basilensis m91-3, a denitrifying soil bacterium capable of using s-triazines as nitrogen sources. | the purpose of this study was to characterize the phylogenetic and phenotypic traits of m91-3, a soil bacterium capable of mineralizing atrazine (2-chloro-4-n-isopropyl-6-n-ethyl-s-triazine). the isolate was identified as ralstonia basilensis based on 99.5% homology of the 16s rrna sequence and various chemotaxonomic data. the isolate used atrazine as the sole source of energy, carbon, and nitrogen. it could also use several other s-triazines as nitrogen sources. ralstonia basilensis m91-3 was c ... | 2002 | 12619822 |