Publications

cadmium-regulated gene fusions in pseudomonas fluorescens.	to study the mechanisms soil bacteria use to cope with elevated concentrations of heavy metals in the environment, a mutagenesis with the lacz-based reporter gene transposon tn5b20 was performed. random gene fusions in the genome of the common soil bacterium pseudomonas fluorescens strain atcc 13525 were used to create a bank of 5,000 p. fluorescens mutants. this mutant bank was screened for differential gene expression in the presence of the toxic metal cadmium. fourteen mutants were identified ...	2000	11234925
modification of the aggregation behaviour of the environmental ralstonia eutropha-like strain ae815 is reflected by both surface hydrophobicity and amplified fragment length polymorphism (aflp) patterns.	after inoculation of the plasmid-free non-aggregative ralstonia eutropha-like strain ae815 in activated sludge, followed by reisolation on a selective medium, a mutant strain a3 was obtained, which was characterized by an autoaggregative behaviour. strain a3 had also acquired an incp1 plasmid, plme1, co-aggregated with yeast cells when co-cultured, and stained better with congo red than did the ae815 strain. contact angle measurements showed that the mutant strain was considerably more hydrophob ...	2000	11243262
control of virulence and pathogenicity genes of ralstonia solanacearum by an elaborate sensory network.	ralstonia solanacearum causes a lethal bacterial wilt disease of diverse plants. it invades the xylem vessels of roots and disseminates into the stem where it multiplies and wilts by excessive exopolysaccharide production. many of its key extracytoplasmic virulence and pathogenicity factors are transcriptionally controlled by an extensive network of distinct, interacting signal transduction pathways. the core of this sensory network is the five-gene phc system that regulates exopolysaccharide, c ...	2000	11701844
kinetic and mechanistic characterization of the polyhydroxybutyrate synthase from ralstonia eutropha.	purified ralstonia eutropha polyhydroxybutyrate (phb) synthase from recombinant cells can exist as monomer and dimer. the polymerization reaction catalyzed by this enzyme displays a lag phase, which causes difficulties for kinetic and mechanistic characterization of the enzymatic polymerization reaction. in this study, we developed a method to eliminate the lag phase of phb synthase by physical means, i.e., adding multihydroxyl compounds to the enzyme solution. this method allows us to recognize ...	2000	11710107
in vitro polymerization and copolymerization of 3-hydroxypropionyl-coa with the phb synthase from ralstonia eutropha.	the poly(3-hydroxybutyrate) (phb) synthase of ralstonia eutropha, which was produced by a recombinant strain of escherichia coli and purified in one step with a methyl-hic column to a purity of more than 90%, was used to polymerize 3-hydroxypropionyl-coa (3hpcoa) and to copolymerize 3hpcoa with 3-hydroxybutyryl-coa (3hbcoa). a km of 189 microm and a kcat of 10 s-1 were determined for the activity of the enzyme in the polymerization reaction of 3hpcoa based on the assumption that the dimer form o ...	2000	11710134
biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyalkanoates) by recombinant bacteria expressing the pha synthase gene phac1 from pseudomonas sp. 61-3.	pseudomonas sp. 61-3 accumulated a blend of poly(3-hydroxybutyrate) [p(3hb)] homopolymer and a random copolymer consisting of 3-hydroxyalkanoate (3ha) units of 4-12 carbon atoms. the genes encoding beta-ketothiolase (phba(re)) and nadph-dependent acetoacetyl-coa reductase (phbb(re)) from ralstonia eutropha were expressed under the control of promoters for pseudomonas sp. 61-3 pha locus or r. eutropha phb operon together with phac1(ps) gene (pha synthase 1 gene) from pseudomonas sp. 61-3 in pha-n ...	2000	10803895
sequence of pha synthase gene from two strains of rhodospirillum rubrum and in vivo substrate specificity of four pha synthases across two heterologous expression systems.	a 3.0-kb genomic fragment has been isolated from rhodospirillum rubrum (atcc 25903) that contains an open reading frame (orf) with strong homology to other known polyhydroxyalkanoate (pha) synthase genes. this orf has lower homology to the r. rubrum strain ha pha synthase than would be expected within the same species. we have conducted a series of heterologous expression studies evaluating the in vivo substrate specificity of pha synthase genes from rhodobacter sphaeroides, ralstonia eutropha ( ...	2000	10803898
polyhydroxyalkanoate accumulation in burkholderia sp.: a molecular approach to elucidate the genes involved in the formation of two homopolymers consisting of short-chain-length 3-hydroxyalkanoic acids.	burkholderia sp. accumulates polyhydrox-yalkanoates (phas) containing 3-hydroxybutyrate and 3-hydroxy-4-pentenoic acid when grown on mineral media under limited phosphate or nitrogen, and using sucrose or gluconate as a carbon and energy source. solvent fractionation and nmr spectroscopic characterization of these polyesters revealed the simultaneous accumulation of two homopolyesters rather than a co-polyester with random sequence distribution of the monomers [valentin he, berger pa, gruys kj, ...	2000	10803903
heavy metal-resistant bacteria as extremophiles: molecular physiology and biotechnological use of ralstonia sp. ch34.	in contrast to thermophilic or psychrophilic organisms, heavy metal-resistant bacteria do not supply enzymes that are active under harsh conditions, but are themselves tools for the evaluation and remediation of heavy metal-contaminated environments. ralstonia sp. ch34 is a gram-negative bacterium with a remarkable set of resistance determinants, allowing this bacterium to live in extreme environments that are heavily contaminated with toxic metal ions. these heavy metal ions are mostly detoxifi ...	2000	10805561
a bacterial sensor of plant cell contact controls the transcriptional induction of ralstonia solanacearum pathogenicity genes.	the hrp genes of the plant pathogen ralstonia solanacearum are key pathogenicity determinants; they encode a type iii protein secretion machinery involved in the secretion of mediators of the bacterium-plant interaction. these hrp genes are under the genetic control of the hrpb regulatory gene, expression of which is induced when bacteria are co-cultivated with plant cell suspensions. in this study, we used hrp-gfp transcriptional fusions to demonstrate that the expression of the hrpb and type i ...	2000	10811621
acidovorax anthurii sp. nov., a new phytopathogenic bacterium which causes bacterial leaf-spot of anthurium.	the bacterial leaf-spot of anthurium emerged during the 1980s, in the french west indies and trinidad. this new bacterial disease is presently wide spread and constitutes a serious limiting factor for commercial anthurium production. twenty-nine strains isolated from leaf-spots of naturally infected anthurium were characterized and compared with reference strains belonging to the comamonadaceae family, the genera ralstonia and burkholderia, and representative fluorescent pseudomonads. from artif ...	2000	10826809
engineering a mouse metallothionein on the cell surface of ralstonia eutropha ch34 for immobilization of heavy metals in soil.	here we describe targeting of the mouse metallothionein i (mt) protein to the cell surface of the heavy metal-tolerant ralstonia eutropha (formerly alcaligenes eutrophus) ch34 strain, which is adapted to thrive in soils highly polluted with metal ions. dna sequences encoding mt were fused to the autotransporter beta-domain of the iga protease of neisseria gonorrhoeae, which targeted the hybrid protein toward the bacterial outer membrane. the translocation, surface display, and functionality of t ...	2000	10835606
construction of recombinant escherichia coli strains for polyhydroxybutyrate production using soy waste as nutrient.	construction and comparison of recombinant escherichia coli strains harboring the polyhydroxybutyrate (phb) operon from ralstonia eutropha using vectors possessing different promotors, as well as the production of phb from soy waste by the recombinant strain, are reported. the lac promotor was the most efficient on expression of the phb operon among the three promotors studied: i.e., lac promotor, t7 promotor and the normal sigma 70 promotor. the pks/phb was the most efficient plasmid for phb op ...	2000	10849804
polyhydroxybutyrate production from carbon dioxide by cyanobacteria.	genetic characterization and enhancement of polyhydroxybutyrate (phb) accumulation in cyanobacteria were investigated for efficient phb production from co2. the genome dnas in the phb-accumulating strains synechococcus sp. ma19 and spirulina platensis nies46 retained the highly homologous region to phac of synechocystis pcc6803, whereas low homology was detected in the nonaccumulating strains synechococcus sp. pcc7942 and anabaena cylindrica nies19. synechococcus sp. ma19, which accumulates phb ...	2000	10849853
phosphotransacetylase as a key factor in biological production of polyhydroxybutyrate.	phosphotransacetylase (pta) catalyzes the reversible conversion of acetyl-coenzyme a (coa) to acetyl phosphate. polyhydroxybutyrate (phb) synthase and accumulation were compared between a pta-deficient mutant and the wild-type escherichia coli, which were transformed with pae100, coding for 3-ketothiolase, nadph-dependent acetoacetyl-coa reductase, and phb synthase from ralstonia eutropha. during the growth period, phb synthase activity in the pta-deficient mutant was lower than that in the wild ...	2000	10849856
deletions of mob and tra pjp4 transfer functions after mating of ralstonia eutropha jmp134 (pjp4) with escherichia coli harboring f'::tn10.	one-tenth of escherichia coli transconjugants resulting from the transfer of the catabolic plasmid pjp4 from ralstonia eutropha jmp134 to e. coli xl1blue, contained pjp4 derivatives with deletions (approximately 15-30 kb). the occurrence of these deletions is probably associated with the presence of tn10 in the recipient. dna endonuclease restriction analysis of the pjp4 deletion derivatives showed the absence of sphi and ecori fragments previously reported to hybridize with incp tra dna probes. ...	2000	10872085
detection of ralstonia solanacearum strains with a quantitative, multiplex, real-time, fluorogenic pcr (taqman) assay.	a fluorogenic (taqman) pcr assay was developed to detect ralstonia solanacearum strains. two fluorogenic probes were utilized in a multiplex reaction; one broad-range probe (rs) detected all biovars of r. solanacearum, and a second more specific probe (b2) detected only biovar 2a. amplification of the target was measured by the 5' nuclease activity of taq dna polymerase on each probe, resulting in emission of fluorescence. taqman pcr was performed with dna extracted from 42 r. solanacearum and g ...	2000	10877778
genetic diversity of ralstonia solanacearum as assessed by pcr-rflp of the hrp gene region, aflp and 16s rrna sequence analysis, and identification of an african subdivision.	the genetic diversity among strains in a worldwide collection of ralstonia solanacearum, causal agent of bacterial wilt, was assessed by using three different molecular methods. pcr-rflp analysis of the hrp gene region was extended from previous studies to include additional strains and showed that five amplicons were produced not only with all r. solanacearum strains but also with strains of the closely related bacteria pseudomonas syzygii and the blood disease bacterium (bdb). however, the thr ...	2000	10878132
characterization of a second tfd gene cluster for chlorophenol and chlorocatechol metabolism on plasmid pjp4 in ralstonia eutropha jmp134(pjp4).	within the 5.9-kb dna region between the tfdr and tfdk genes on the 2,4-dichlorophenoxyacetic acid (2,4-d) catabolic plasmid pjp4 from ralstonia eutropha jmp134, we identified five open reading frames (orfs) with significant homology to the genes for chlorocatechol and chlorophenol metabolism (tfdcdef and tfdb) already present elsewhere on pjp4. the five orfs were organized and assigned as follows: tfdd(ii)c(ii)e(ii)f(ii) and tfdb(ii) (in short, the tfd(ii) cluster), by analogy to tfdcdef and tf ...	2000	10894723
biochemical-genetic characterization and distribution of oxa-22, a chromosomal and inducible class d beta-lactamase from ralstonia (pseudomonas) pickettii.	from genomic dna of ralstonia pickettii isolate pic-1, a beta-lactamase gene was cloned that encodes the oxacillinase oxa-22. it differs from known oxacillinases, being most closely related to oxa-9 (38% amino acid identity). the hydrolytic spectrum of oxa-22 is limited mostly to benzylpenicillin, cloxacillin, and restricted-spectrum cephalosporins. oxa-22-like genes were identified as single chromosomal copies in five other r. pickettii clinical isolates. the expression of oxa-22-like beta-lact ...	2000	10898703
novel insertion sequence elements associated with genetic heterogeneity and phenotype conversion in ralstonia solanacearum.	three insertion sequences (is) elements were isolated from the phytopathogen ralstonia solanacearum. southern hybridization using these is elements as probes revealed hybridization profiles that varied greatly between different strains of the pathogen. during a spontaneous phenotype conversion event, the promoter of the phca gene was interrupted by one of these is elements.	2000	10913109
comparison of 2,4-dichlorophenoxyacetic acid degradation and plasmid transfer in soil resulting from bioaugmentation with two different pjp4 donors.	a pilot field study was conducted to assess the impact of bioaugmentation with two plasmid pjp4-bearing microorganisms: the natural host, ralstonia eutropha jmp134, and a laboratory-generated strain amenable to donor counterselection, escherichia coli d11. the r. eutropha strain contained chromosomal genes necessary for mineralization of 2,4-dichlorophenoxyacetic acid (2,4-d), while the e. coli strain did not. the soil system was contaminated with 2,4-d alone or was cocontaminated with 2,4-d and ...	2000	10919798
kinetics of biodegradation of p-nitrophenol by different bacteria.	three bacterial species, i.e., ralstonia sp. sj98, arthrobacter protophormiae rkj100, and burkholderia cepacia rkj200, have been examined for their efficiency and kinetics behavior toward pnp degradation. all the three bacteria utilized pnp as the sole source of carbon, nitrogen, and energy. the rates of radiolabeled [u-(14)c]pnp degradation by all the bacteria were higher in the nitrogen-free medium compared to the medium with nitrogen. the apparent k(m) values of pnp degradation by sj98, rkj10 ...	2000	10924328
a comparison of the microcount digital system to plate count and membrane filtration methods for the enumeration of microorganisms in water for pharmaceutical purposes.	the enumeration of microorganisms in water for pharmaceutical purposes using the microcount digital system (millipore corporation, bedford, ma) was compared to the usp-recommended pour plate and membrane filtration count methods. a study, using a pure culture of buckholderia cepacia, atcc#25416, showed that the accuracy, precision, reproducibility and linearity of the microcount atp bioluminescence system was equivalent to or better than the traditional methods. when the microcount system was us ...	2000	10927910
taxonomic position of "pseudomonas oxalaticus" strain ox14t (dsm 1105t) (khambata and bhat, 1953) and its description in the genus ralstonia as ralstonia oxalatica comb. nov.	"pseudomonas oxalaticus" strain ox1t (= dsm 1105t), which was described as an oxalate-decomposing bacterium, was reinvestigated to clarify its taxonomic position. 16s ribosomal dna sequence comparisons demonstrated that this species is phylogenetically related to the species of the genus ralstonia. and represents a new species. the result of the dna-dna hybridization value was supported in this placement. strain ox1t is closely related to ralstonia eutropha with a less than 60% dna-dna hybridiza ...	2000	10930072
rapid detection of polyhydroxyalkanoate-accumulating bacteria isolated from the environment by colony pcr.	colony pcr and semi-nested pcr techniques were employed for screening polyhydroxyalkanoate (pha) producers isolated from the environment. three degenerate primers were designed based on multiple sequence alignment results and were used as pcr primers to detect pha synthase genes. optimized colony pcr conditions were achieved by adding 3% dmso combined with 1 m betaine to the reaction mixture. the sensitivity limit of the colony pcr was 1x 10(5) viable cells for ralstonia eutropha. nineteen pha-p ...	2000	10931906
recovery of poly(3-hydroxybutyrate) from coagulated ralstonia eutropha using a chemical digestion method.	for economic recovery of poly(3-hydroxybutyrate) (phb) from culture broths of ralstonia eutropha containing phb, al-based and fe-based coagulants were used in the pretreatment step. the coagulated cells were then separated by centrifugation, and phb was extracted by chemical digestion with a sodium hypochlorite/chloroform dispersion solution. the practical upper limits of dosage were found to be 1, 500 mg-al/l and 1,000 mg-fe/l, respectively, for al- and fe-based coagulants. when the harvested c ...	2000	10933846
phosphoenolpyruvate is a signal metabolite in transcriptional control of the cbb co2 fixation operons in ralstonia eutropha.	the two highly homologous cbb operons of the facultative chemoautotroph ralstonia eutropha h16 encode most enzymes of the calvin-benson-bassham carbon reduction cycle. their transcriptional regulation was investigated both in vitro and in vivo to identify a metabolic signal involved in this process. for this purpose an in vitro transcription system employing the dna-dependent rna polymerase purified from r. eutropha was established. the enzyme from escherichia coli was also used in verifying com ...	2000	10937440
chemotaxis and biodegradation of 3-methyl- 4-nitrophenol by ralstonia sp. sj98.	3-methyl-4-nitrophenol is one of the major breakdown products of fenitrothion [o,o-dimethyl o-(3-methyl-4-nitrophenyl) thiophosphate], a recalcitrant organophosphate insecticide used in agriculture. being the non-polar methylated aromatic compound, 3-methyl-4-nitrophenol is highly toxic and, therefore, a complete degradation of this compound is important for environmental decontamination/bioremediation purposes. a gram negative, motile ralstonia sp. sj98 was isolated by selective screening from ...	2000	10944453
gonococcal nitric oxide reductase is encoded by a single gene, norb, which is required for anaerobic growth and is induced by nitric oxide.	the gene encoding a nitric oxide reductase has been identified in neisseria gonorrhoeae. the norb gene product shares significant identity with the nitric oxide reductases in ralstonia eutropha and synechocystis sp. and, like those organisms, the gonococcus lacks a norc homolog. the gonococcal norb gene was found to be required for anaerobic growth, but the absence of norb did not dramatically decrease anaerobic survival. in a wild-type background, induction of norb expression was seen anaerobic ...	2000	10948150
in vitro synthesis of poly(3-hydroxydecanoate): purification and enzymatic characterization of type ii polyhydroxyalkanoate synthases phac1 and phac2 from pseudomonas aeruginosa.	for the first time, the purification has been achieved of the type ii polyhydroxyalkanoate (pha) synthases phac1 and phac2 from pseudomonas aeruginosa applying n-terminal his6-tag fusions and metal chelate affinity chromatography. in vivo his6-tagged pha synthase activity was confirmed by functional expression of the corresponding genes in escherichia coli, and pha synthase activity could also be measured in vitro with the enzymes. the specific enzyme activity of pha synthases phac1 and phac2 wa ...	2000	10952003
a broad-host-range plasmid for isolating mobile genetic elements in gram-negative bacteria.	plasmid pgbg1 was constructed to isolate mobile genetic elements in a wide variety of gram-negative bacteria. the mutation target, carried on a broad-host-range vector, allows positive selection for tetracycline resistance. in tests using several gram-negative bacteria we could detect transposition events of either insertion sequences or transposons. a new insertion sequence (is) element was identified in ralstonia eutropha.	2000	10964631
starvation improves survival of bacteria introduced into activated sludge.	a phenol-degrading bacterium, ralstonia eutropha e2, was grown in luria-bertani (lb) medium or in an inorganic medium (called mp) supplemented with phenol and harvested at the late-exponential-growth phase. phenol-acclimated activated sludge was inoculated with the e2 cells immediately after harvest or after starvation in mp for 2 or 7 days. the densities of the e2 populations in the activated sludge were then monitored by quantitative pcr. the e2 cells grown on phenol and starved for 2 days (p- ...	2000	10966407
toluene-degrading bacteria are chemotactic towards the environmental pollutants benzene, toluene, and trichloroethylene.	the bioremediation of polluted groundwater and toxic waste sites requires that bacteria come into close physical contact with pollutants. this can be accomplished by chemotaxis. five motile strains of bacteria that use five different pathways to degrade toluene were tested for their ability to detect and swim towards this pollutant. three of the five strains (pseudomonas putida f1, ralstonia pickettii pko1, and burkholderia cepacia g4) were attracted to toluene. in each case, the response was de ...	2000	10966434
plant genome complexity may be a factor limiting in situ the transfer of transgenic plant genes to the phytopathogen ralstonia solanacearum.	the development of natural competence by bacteria in situ is considered one of the main factors limiting transformation-mediated gene exchanges in the environment. ralstonia solanacearum is a plant pathogen that is also a naturally transformable bacterium that can develop the competence state during infection of its host. we have attempted to determine whether this bacterium could become the recipient of plant genes. we initially demonstrated that plant dna was released close to the infecting ba ...	2000	10966449
factors influencing the biosorption of gadolinium by micro-organisms and its mobilisation from sand.	the present work was devoted to the study of the biosorption capacities of various microbial species (bacillus subtilis, pseudomonas aeruginosa, ralstonia metallidurans ch34 previously alcaligenes eutrophus ch34, mycobacterium smegmatis, saccharomyces cerevisiae) for ions of the lanthanide gadolinium (gd3+). the uptake by sand of this element was also measured. saturation curves and scatchard models were established for all biosorbants used in this work. the results enabled us to determine the b ...	2000	10968643
degradation of 2,4,6-trichlorophenol via chlorohydroxyquinol in ralstonia eutropha jmp134 and jmp222.	the aim of this work was to study the catabolic pathway of the pollutant 2,4,6-trichlorophenol in ralstonia eutropha jmp134. 2,6-dichlorohydroquinone was detected as transient intermediate. enzymatic transformations of 6-chlorohydroxyquinol to 2-chloromaleylacetate, and of this compound to maleylacetate were detected in crude extracts. therefore, the degradation of 2,4,6-trichlorophenol proceeded through an hydroxyquinol pathway, different from the other chloroaromatic pathways reported in this ...	2000	10986670
mobilization of poly(3-hydroxybutyrate) in ralstonia eutropha.	ralstonia eutropha h16 degraded (mobilized) previously accumulated poly(3-hydroxybutyrate) (phb) in the absence of an exogenous carbon source and used the degradation products for growth and survival. isolated native phb granules of mobilized r. eutropha cells released 3-hydroxybutyrate (3hb) at a threefold higher rate than did control granules of nonmobilized bacteria. no 3hb was released by native phb granules of recombinant escherichia coli expressing the phb biosynthetic genes. native phb gr ...	2000	11004196
substrate specificity of atrazine chlorohydrolase and atrazine-catabolizing bacteria.	bacterial atrazine catabolism is initiated by the enzyme atrazine chlorohydrolase (atza) in pseudomonas sp. strain adp. other triazine herbicides are metabolized by bacteria, but the enzymological basis of this is unclear. here we begin to address this by investigating the catalytic activity of atza by using substrate analogs. purified atza from pseudomonas sp. strain adp catalyzed the hydrolysis of an atrazine analog that was substituted at the chlorine substituent by fluorine. atza did not cat ...	2000	11010866
cometabolic degradation of dibenzofuran by biphenyl-cultivated ralstonia sp. strain sbug 290.	cells of the gram-negative bacterium ralstonia sp. strain sbug 290 grown in the presence of biphenyl are able to cooxidize dibenzofuran which has been 1,2-hydroxylated. meta cleavage of the 1, 2-dihydroxydibenzofuran between carbon atoms 1 and 9b produced 2-hydroxy-4-(3'-oxo-3'h-benzofuran-2'-yliden)but-2-enoic acid, which was degraded completely via salicylic acid. the presence of these intermediates indicates a degradation mechanism for dibenzofuran via lateral dioxygenation by ralstonia sp. s ...	2000	11010910
a bioluminescent whole-cell reporter for detection of 2, 4-dichlorophenoxyacetic acid and 2,4-dichlorophenol in soil.	a bioreporter was made containing a tfdrp(dii)-luxcdabe fusion in a modified mini-tn5 construct. when it was introduced into the chromosome of ralstonia eutropha jmp134, the resulting strain, jmp134-32, produced a sensitive bioluminescent response to 2, 4-dichlorophenoxyacetic acid (2,4-d) at concentrations of 2.0 microm to 5.0 mm. this response was linear (r(2) = 0.9825) in the range of 2.0 microm to 1.1 x 10(2) microm. saturation occurred at higher concentrations, with maximal bioluminescence ...	2000	11010925
ralstonia pickettii colonization of patients in an obstetric ward caused by a contaminated irrigation system.		2000	11023730
exogenous isolation of antibiotic resistance plasmids from piggery manure slurries reveals a high prevalence and diversity of incq-like plasmids.	antibiotic resistance plasmids were exogenously isolated in biparental matings with piggery manure bacteria as plasmid donors in escherichia coli cv601 and pseudomonas putida uwc1 recipients. surprisingly, incq-like plasmids were detected by dot blot hybridization with an incq oriv probe in several p. putida uwc1 transconjugants. the capture of incq-like plasmids in biparental matings indicates not only their high prevalence in manure slurries but also the presence of efficiently mobilizing plas ...	2000	11055935
regulation of hrp genes and type iii protein secretion in erwinia amylovora by hrpx/hrpy, a novel two-component system, and hrps.	two novel regulatory components, hrpx and hrpy, of the hrp system of erwinia amylovora were identified. the hrpxy operon is expressed in rich media, but its transcription is increased threefold by low ph, nutrient, and temperature levels--conditions that mimic the plant apoplast. hrpxy is autoregulated and directs the expression of hrpl; hrpl, in turn, activates transcription of other loci in the hrp gene cluster (z.-m. wei and s. v. beer, j. bacteriol. 177:6201-6210, 1995). the deduced amino -a ...	2000	11059492
evidence that ralstonia eutropha (alcaligenes eutrophus) contains a functional homologue of the ralstonia solanacearum phc cell density sensing system.	in the phytopathogen ralstonia (pseudomonas) solanacearum, control of many virulence genes is partly mediated by the phc cell density sensing system. phc uses a novel self-produced signal molecule [3-hydroxypalmitic acid methyl ester (3-oh pame)], an atypical two-component system (phcs/phcr), and a lysr-type activator (phca) to regulate a reversible switching between two different physiological states. while phc is present in most r. solanacearum strains, it is apparently absent from other pseud ...	2000	11069661
a novel no-responding regulator controls the reduction of nitric oxide in ralstonia eutropha.	ralstonia eutropha h16 mediates the reduction of nitric oxide (no) to nitrous oxide (n2o) with two isofunctional single component membrane-bound no reductases (norb1 and norb2). this reaction is integrated into the denitrification pathway that involves the successive reduction of nitrate to dinitrogen. the norb1 gene is co-transcribed with nora1 from a sigma54 (rpon)-dependent promoter, located upstream of nora1. with the aid of nora1'-lacz transcriptional fusions and the generation of regulator ...	2000	11069685
multicomponent transcriptional regulation at the complex promoter of the exopolysaccharide i biosynthetic operon of ralstonia solanacearum.	high-level transcription of eps, an operon encoding biosynthesis of an exopolysaccharide virulence factor of the phytopathogen ralstonia (pseudomonas) solanacearum, requires the products of at least seven regulatory genes (phca, phcb, xpsr, vsra-vsrd, and vsrb-vsrc), which are organized in three converging signal transduction cascades. because xpsr and the vsrb-vsrc two-component system are the most downstream cascade components required for activation of eps, we explored how these components co ...	2000	11073909
improvement of vitamin b(12) fermentation by reducing the inhibitory metabolites by cell recycle system and a mixed culture.	the major problem in vitamin b(12) production using propionibacterium is the growth inhibition of the cell due to the accumulation of inhibitory metabolites such as propionic acid and acetic acid. in the present paper, we considered several approaches of controlling the propionic acid concentration at low level. namely: (1) the periodic cultivation of propionibacterium where dissolved oxygen (do) concentration was alternatively changed between 0 and 1ppm; (2) cell recycle system using hollow fib ...	2000	11080651
footprinting with an automated capillary dna sequencer.	footprinting is a valuable tool for studying dna-protein contacts. however, it usually involves expensive, tedious and hazardous steps such as radioactive labeling and analyses on polyacrylamide sequencing gels. we have developed an easy four-step footprinting method involving (i) the generation and purification of a pcr fragment that is fluorescently labeled at one end with 6-carboxyfluorescein; (ii) brief exposure of the fragment to a dna-binding protein and then dnase i; (iii) spin-column pur ...	2000	11084866
learning from hydrogenases: location of a proton pump and of a second fmn in bovine nadh--ubiquinone oxidoreductase (complex i).	hydrogenases have clear evolutionary links to the much more complex nadh-ubiquinone oxidoreductases (complex i). certain membrane-bound [nife]-hydrogenases presumably pump protons. from a detailed comparison of hydrogenases and complex i, it is concluded here that the tyky subunit in these enzymes is a special 2[4fe-4s] ferredoxin, which functions as the electrical driving unit for a proton pump. the comparison further revealed that the flavodoxin fold from [nife]-hydrogenases is presumably cons ...	2000	11086155
application of a propionyl coenzyme a synthetase for poly(3-hydroxypropionate-co-3-hydroxybutyrate) accumulation in recombinant escherichia coli.	the genetic operon for propionic acid degradation in salmonella enterica serovar typhimurium contains an open reading frame designated prpe which encodes a propionyl coenzyme a (propionyl-coa) synthetase (a. r. horswill and j. c. escalante-semerena, microbiology 145:1381-1388, 1999). in this paper we report the cloning of prpe by pcr, its overexpression in escherichia coli, and the substrate specificity of the enzyme. when propionate was utilized as the substrate for prpe, a k(m) of 50 microm an ...	2000	11097899
sequencing bands of ribosomal intergenic spacer analysis fingerprints for characterization and microscale distribution of soil bacterium populations responding to mercury spiking.	two major emerging bands (a 350-bp band and a 650-bp band) within the risa (ribosomal intergenic spacer analysis) profile of a soil bacterial community spiked with hg(ii) were selected for further identification of the populations involved in the response of the community to the added metal. the bands were cut out from polyacrylamide gels, cloned, characterized by restriction analysis, and sequenced for phylogenetic affiliation of dominant clones. the sequences were the intergenic spacer between ...	2000	11097911
16s rdna analysis for characterization of denitrifying bacteria isolated from three agricultural soils.	bacteria capable of denitrification are spread among phylogenetically diverse groups. in the present investigation, molecular methods (amplified ribosomal dna restriction analysis (ardra) and partial 16s rdna gene sequencing) were used to determine the genetic diversity of culturable denitrifying soil bacteria. the purpose of this work was to study the microbial density and diversity of denitrifying communities isolated from two luvisols and a rendosol. the denitrifying bacterial density was sig ...	2000	11102689
partial sequencing of the hrpb and endoglucanase genes confirms and expands the known diversity within the ralstonia solanacearum species complex.	we determined partial hrpb and endoglucanase genes sequences for 30 strains of ralstonia solanacearum and one strain of the blood disease bacterium (bdb), a close relative of ralstonia solanacearum. sequence comparisons showed high levels of variability within these two regions of the genome involved in pathogenicity. phylogenetic analysis based upon sequence comparisons of these two regions revealed three major clusters comprising all ralstonia solanacearum isolates, the bdb strain constituted ...	2000	11249017
the rfae gene from escherichia coli encodes a bifunctional protein involved in biosynthesis of the lipopolysaccharide core precursor adp-l-glycero-d-manno-heptose.	the intermediate steps in the biosynthesis of the adp-l-glycero-d-manno-heptose precursor of inner core lipopolysaccharide (lps) are not yet elucidated. we isolated a mini-tn10 insertion that confers a heptoseless lps phenotype in the chromosome of escherichia coli k-12. the mutation was in a gene homologous to the previously reported rfae gene from haemophilus influenzae. the e. coli rfae gene was cloned into an expression vector, and an in vitro transcription-translation experiment revealed a ...	2000	10629197
ralstonia eutropha tf93 is blocked in tat-mediated protein export.	ralstonia eutropha (formerly alcaligenes eutrophus) tf93 is pleiotropically affected in the translocation of redox enzymes synthesized with an n-terminal signal peptide bearing a twin arginine (s/t-r-r-x-f-l-k) motif. immunoblot analyses showed that the catalytic subunits of the membrane-bound [nife] hydrogenase (mbh) and the molybdenum cofactor-binding periplasmic nitrate reductase (nap) are mislocalized to the cytoplasm and to the inner membrane, respectively. moreover, physiological studies s ...	2000	10633089
nickel transport systems in microorganisms.	the transition metal ni is an essential cofactor for a number of enzymatic reactions in both prokaryotes and eukaryotes. molecular analyses have revealed the existence of two major types of high-affinity ni2+ transporters in bacteria. the nik system of escherichia coli is a member of the abc transporter family and provides ni2+ ion for the anaerobic biosynthesis of hydrogenases. the periplasmic binding protein of the transporter, nika, is likely to play a dual role. it acts as the primary binder ...	2000	10648098
resistance of tomato line hawaii7996 to ralstonia solanacearum pss4 in taiwan is controlled mainly by a major strain-specific locus.	bacterial wilt caused by the soilborne bacterium ralstonia solanacearum attacks hundreds of plant species, including many agriculturally important crops. natural resistance to this disease has been found in some species and is usually inherited as a polygenic trait. in tomato, a model crop plant, genetic analysis previously revealed the involvement of several qtl (quantitative trait loci) controlling resistance and, in all of these studies with different strains of the pathogen, loci on chromoso ...	2000	10656580
characterization and role of tbux in utilization of toluene by ralstonia pickettii pko1.	the tbu regulon of ralstonia pickettii pko1 encodes enzymes involved in the catabolism of toluene, benzene, and related alkylaromatic hydrocarbons. the first operon in this regulon contains genes that encode the tbu pathway's initial catabolic enzyme, toluene-3-monooxygenase, as well as tbut, the ntrc-like transcriptional activator for the entire regulon. it has been previously shown that the organization of tbut, which is located immediately downstream of tbua1ubva2c, and the associated promote ...	2000	10671442
regulation of the cnr cobalt and nickel resistance determinant from ralstonia sp. strain ch34.	ralstonia sp. strain ch34 is resistant to nickel and cobalt cations. resistance is mediated by the cnr determinant located on plasmid pmol28. the cnr genes are organized in two clusters, cnryxh and cnrcba. as revealed by reverse transcriptase pcr and primer extension, transcription from these operons is initiated from promoters located upstream of the cnry and cnrc genes. these two promoters exhibit conserved sequences at the -10 (ccgtata) and -35 (craggggrag) regions. the cnrh gene product, whi ...	2000	10671463
regulation of the cnr cobalt and nickel resistance determinant of ralstonia eutropha (alcaligenes eutrophus) ch34.	the linked resistance to nickel and cobalt of ralstonia eutropha-like strain ch34 (alcaligenes eutrophus ch34) is encoded by the cnr operon, which is localized on the megaplasmid pmol28. the regulatory genes cnryxh have been cloned, overexpressed, and purified in escherichia coli. cnry fractionated as a 10.7-kda protein in in vitro translation assays. cnrx, a periplasmic protein of 16.5 kda, was overproduced and purified as a histidine-tagged fusion protein in e. coli. his-cnrx was found to poss ...	2000	10671464
bacterial triterpenoids of the hopane series as biomarkers for the chemotaxonomy of burkholderia, pseudomonas and ralstonia spp.	hopanoid fingerprints allowed to differentiate bacteria formerly connected to the genus pseudomonas. whereas all strains related to pseudomonas and ralstonia were devoid of any detectable hopanoid, these pentacyclic triterpenoids were found in the burkholderia species and in related soil isolates, which contained as main hopanoid a bacteriohopanetetrol carbapseudopentose ether, accompanied by significant amounts of its novel delta(6) unsaturated homologue. unsaturated hopanoids represent an extr ...	2000	10675600
calorimetrically recognized maximum yield of poly-3-hydroxybutyrate (phb) continuously synthesized from toxic substrates.	the broader usage of poly-beta-hydroxybutyrate (phb), for instance as bulk plastics, calls for cheap raw materials and greater overall process efficiency. the bacterial synthesis is generally induced and promoted by the limitation of growth via nitrogen, oxygen or phosphate depletion with the simultaneous excess and higher concentration of the carbon substrate. consequently, toxic substrates have been considered unsuitable for phb synthesis. nevertheless, a single-stage continuous process for pr ...	2000	10682283
unusual ftir and epr properties of the h2-activating site of the cytoplasmic nad-reducing hydrogenase from ralstonia eutropha.	soluble nad-reducing [nife]-hydrogenase (sh) from ralstonia eutropha (formerly alcaligenes eutrophus) has an infrared spectrum with one strong band at 1956 cm(-1) and four weak bands at 2098, 2088, 2081 and 2071 cm(-1) in the 2150-1850 cm(-1) spectral region. other [nife]-hydrogenases only show one strong and two weak bands in this region, attributable to the nife(cn)2(co) active site. the position of these three bands is highly sensitive to redox changes of the active site. in contrast, reducti ...	2000	10682839
chemotaxis of a ralstonia sp. sj98 toward different nitroaromatic compounds and their degradation.	a ralstonia sp. sj98, isolated by a chemotactic enrichment technique, was capable of utilizing different nitroaromatic compounds (nacs). it utilized p-nitrophenol, 4-nitrocatechol, o-nitrobenzoic acid, and p-nitrobenzoic acid as the sole source of carbon and energy. it was observed that ralstonia sp. sj98 was chemotactic to the above-mentioned nacs as tested by the drop assay, swarm plate assay, and capillary assay. however, it failed to show chemotactic behavior toward those compounds which wer ...	2000	10694487
the hrpb and hrpg regulatory genes of ralstonia solanacearum are required for different stages of the tomato root infection process.	hrp genes, encoding type iii secretion machinery, have been shown to be key determinants for pathogenicity in the vascular phytopathogenic bacterium ralstonia solanacearum gmi1000. here, we show phenotypes of r. solanacearum mutant strains disrupted in the prhj, hrpg, or hrpb regulatory genes with respect to root infection and vascular colonization in tomato plants. tests of bacterial colonization and enumeration in tomato plants, together with microscopic observations of tomato root sections, r ...	2000	10707351
production of polyhydroxyalkanoic acids by ralstonia eutropha and pseudomonas oleovorans from an oil remaining from biotechnological rhamnose production.	screening experiments identified several bacteria which were able to use residual oil from biotechnological rhamnose production as a carbon source for growth. ralstonia eutropha h16 and pseudomonas oleovorans were able to use this waste material as the sole carbon source for growth and for the accumulation of polyhydroxyalkanoic acids (pha). r. eutropha and p. oleovorans accumulated pha amounting to 41.3% and 38.9%, respectively, of the cell dry mass, when these strains were cultivated in minera ...	2000	10709978
novel regioselective hydroxylations of pyridine carboxylic acids at position c2 and pyrazine carboxylic acids at position c3.	we have previously described the isolation of the new bacterial species, ralstonia/burkholderia sp. strain dsm 6920, which grows with 6-methylnicotinate and regioselectively hydroxylates this substrate in the c2 position by the action of 6-methylnicotinate-2-oxidoreductase to yield 2-hydroxy-6-methylnicotinate (tinschert et al. 1997). in the present study we show that this enzymatic activity can be used for the preparation of a series of hydroxylated heterocyclic carboxylic acid derivatives. the ...	2000	10709981
identification of two novel hrp-associated genes in the hrp gene cluster of xanthomonas oryzae pv. oryzae.	we have cloned a hrp gene cluster from xanthomonas oryzae pv. oryzae. bacteria with mutations in the hrp region have reduced growth in rice leaves and lose the ability to elicit a hypersensitive response (hr) on the appropriate resistant cultivars of rice and the nonhost plant tomato. a 12,165-bp portion of nucleotide sequence from the presumed left end and extending through the hrpb operon was determined. the region was most similar to hrp genes from xanthomonas campestris pv. vesicatoria and r ...	2000	10714988
transformation of 1,1-dichloro-2,2-(4-chlorophenyl)ethane (ddd) by ralstonia eutropha strain a5.	evidence is presented demonstrating the ability of ralstonia eutropha a5 to degrade 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (ddd) aerobically. strain a5 was able to effect significant transformation of [(14)c]ddd: the hexane extractable radioactivity decreased to approximately 50% of the controls while more than 25% of the total radioactivity became associated with the acidified culture supernatant. there was also an increase in the amount of radioactivity associated with the cell pellet when ...	2000	10719206
detection of type iii secretion system genes in animal isolates of bordetella bronchiseptica.	a cosmid clone bank of bordetella bronchiseptica genomic dna was screened for the presence of type iii secretion (tts) genes using a probe derived from the tts system genes of ralstonia solanacearum. a 3.35kb psti fragment, sub-cloned from a hybridising cosmid clone, was sequenced and found to contain a 97bp overlap with the previously reported b. bronchiseptica bscijklno tts gene cluster. dna and predicted protein homology analysis suggests that a bscpqrst cluster lies immediately downstream of ...	2000	10727842
properties of engineered poly-3-hydroxyalkanoates produced in recombinant escherichia coli strains.	to prepare medium-chain-length poly-3-hydroxyalkanoates (phas) with altered physical properties, we generated recombinant escherichia coli strains that synthesized phas with altered monomer compositions. experiments with different substrates (fatty acids with different chain lengths) or different e. coli hosts failed to produce phas with altered physical properties. therefore, we engineered a new potential pha synthetic pathway, in which ketoacyl-coenzyme a (coa) intermediates derived from the b ...	2000	10742205
role of tfdc(i)d(i)e(i)f(i) and tfdd(ii)c(ii)e(ii)f(ii) gene modules in catabolism of 3-chlorobenzoate by ralstonia eutropha jmp134(pjp4).	the enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow ralstonia eutropha jmp134(pjp4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-cb). there are two gene modules located in plasmid pjp4, tfdc(i)d(i)e(i)f(i) (module i) and tfdd(ii)c(ii)e(ii)f(ii) (module ii), putatively encoding these enzymes. to assess the role of both tfd modules in the degradation of chloroaro ...	2000	10742248
biodegradation of carbazole by ralstonia sp. rjgii.123 isolated from a hydrocarbon contaminated soil.	the use of microorganisms for bioremediation of contaminated soils may be enhanced with an understanding of the pathways involved in their degradation of hazardous compounds. ralstonia sp. strain rjgii.123 was isolated from soil located at a former coal gasification plant, based on its ability to mineralize carbazole, a three-ring n-heterocyclic pollutant. experiments were carried out with strain rjghii.123 and 14c-carbazole (2 mg/l and 500 mg/l) as the sole organic carbon source. at 15 days, 80 ...	2000	10749540
detection and characterization of plasmid pjp4 transfer to indigenous soil bacteria.	prior to gene transfer experiments performed with nonsterile soil, plasmid pjp4 was introduced into a donor microorganism, escherichia coli atcc 15224, by plate mating with ralstonia eutropha jmp134. genes on this plasmid encode mercury resistance and partial 2, 4-dichlorophenoxyacetic acid (2,4-d) degradation. the e. coli donor lacks the chromosomal genes necessary for mineralization of 2,4-d, and this fact allows presumptive transconjugants obtained in gene transfer studies to be selected by p ...	2000	10618238
poly(3-hydroxybutyrate-co-4-hydroxybutyrate) formation from gamma-aminobutyrate and glutamate.	to provide 4-hydroxybutyryl-coa for poly(3-hydroxybutyrate-co-4-hydroxybutyrate) formation from glutamate in escherichia coli, an acetyl-coa:4-hydroxybutyrate coa transferase from clostridium kluyveri, a 4-hydroxybutyrate dehydrogenase from ralstonia eutropha, a gamma-aminobutyrate:2-ketoglutarate transaminase from escherichia coli, and glutamate decarboxylases from arabidopsis thaliana or e. coli were cloned and functionality tested by expression of single genes in e. coli to verify enzymatic a ...	2000	10620259
analysis of in vivo substrate specificity of the pha synthase from ralstonia eutropha: formation of novel copolyesters in recombinant escherichia coli.	in order to investigate the in vivo substrate specificity of the type i polyhydroxyalkanoate (pha) synthase from ralstonia eutropha, we functionally expressed the pha synthase gene in various escherichia coli mutants affected in fatty acid beta-oxidation and the wild-type. the pha synthase gene was expressed either solely (pbhr70) or in addition to the r. eutropha genes encoding beta-ketothiolase and acetoacetyl-coenzyme a (coa) reductase comprising the entire phb operon (pbhr68) as well as in c ...	2000	10612741
biosynthesis and properties of poly(3-hydroxybutyrate-co-3-hydroxyalkanoates) by recombinant strains of pseudomonas sp. 61-3.	pseudomonas sp. 61-3 (phbc::tet) strain, which is a phbcps-disrupted mutant, accumulated a random copolymer consisting of (r)-3-hydroxybutyrate (3hb) and (r)-medium-chain-length 3-hydroxyalkanoate (3ha) units of 6-12 carbon atoms, but the 3hb fraction in the copolymer was less than 50 mol %, resulting in the formation of an amorphus polymer. therefore, the genes encoding beta-ketothiolase (phbare) and nadph-dependent acetoacetyl-coa reductase (phbbre) from ralstonia eutropha were expressed under ...	2000	11709837
catabolic and genetic diversity of degradative bacteria from fuel-hydrocarbon contaminated aquifers.	a bstractsubsurface sediments were recovered from two aquifers contaminated with petroleum hydrocarbons in order to isolate and characterize indigenous microorganisms capable of biodegrading fuel-related compounds. these sediments had been previously studied using catabolic gene probes providing putative demonstration of significant biodegradation potential. based on 16s rdna sequence analysis, the isolates were phylogenetically similar to common soil microorganisms, including members of the gen ...	2000	12035098
synthesis of microbial poly(beta-hydroxybutyrate) modified with oligo(pentaerythritol ethoxylate) by ralstonia eutropha.	poly(beta-hydroxybutyrate) (phb) modified with different amounts of pentaerythritol ethoxylate (pee) has been synthesized using ralstonia eutropha. the growth kinetics and the synthesis of phb in the presence of pee were modeled using appropriate differential equations for the mass balance of the two-stage process. the influence of pee addition on the morphology of phb was studied by various microscopic and scattering techniques. light microscopic and wide-angle x-ray measurements indicated that ...	2001	11710010
biosynthesis of poly(3-hydroxybutyrate-co-3-mercaptobutyrate) as a sulfur analogue to poly(3-hydroxybutyrate) (phb).	a hitherto unknown copolymer that contains sulfur in the backbone linking 3-hydroxybutyrate and 3-mercaptobutyrate by thioester linkages, poly(3hb-co-3mb), was synthesized by the polyhydroxyalkanoate-(pha-) accumulating bacterium ralstonia eutropha, when 3-mercaptobutyric acid was fed as the carbon source in addition to gluconate. the chemical structure of this novel polymer was confirmed by gas chromatography/mass spectrometry, infrared spectroscopy, 1h and 13c nuclear magnetic resonance spectr ...	2001	11710011
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 ...	2001	11710052
a local accumulation of the ralstonia solanacearum popa protein in transgenic tobacco renders a compatible plant-pathogen interaction incompatible.	plants activate disease resistance responses when they recognize pathogen-derived molecules (elicitors). frequently, recognition results in a hypersensitive response (hr), which is characterized by local host cell death at the infection site. here we describe a genetic engineering approach to generate an hr in plants, whether or not an invading micro-organism produces a recognized elicitor. to that aim we created transgenic tobacco plants in which the pathogen-inducible promoter of the hsr203j g ...	2001	11737779
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 ...	2001	11739754
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 ...	2001	11739767
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 ...	2001	11749154
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 ...	2001	11749180
molecular cloning and sequencing of the gene encoding an exopolygalacturonase of a bacillus isolate and properties of its recombinant enzyme.	an exopolygalacturonase (exo-pgase; ec 3.2.1.82) was found in the culture broth of a bacillus isolate. the gene encoding the exo-pgase, pehk, was cloned by polymerase chain reaction using mixed primers designed from n-terminal and internal amino acid (aa) sequences of the enzyme (pehk). the determined nucleotide (nt) sequence of pehk revealed a 2940 bp open reading frame (980 aa) that encoded a putative signal sequence (27 aa) and a mature protein (953 aa; 103810 da). the recombinant enzyme was ...	2001	11750764
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 ...	2001	11846762
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 ...	2001	11846770
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 ...	2001	11846772
comonomer unit composition and thermal properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)s biosynthesized by ralstonia eutropha.	a series of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)s [p(3hb-co-4hb)s] with different 4hb content, biosynthesized by ralstonia eutropha h16 with mixed carbon sources of 4-hydroxybutyric acid (4hba) and butyric acid, were fractionated by solvent/nonsolvent fractionation into copolyester fractions with different 4hb content and narrower compositional distribution. the fractions obtained were classified into two groups, 3hb- and 4hb-rich p(3hb-co-4hb)s. the thermal properties were investigated ...	2001	11777405
heterologous expression of cyanophycin synthetase and cyanophycin synthesis in the industrial relevant bacteria corynebacterium glutamicum and ralstonia eutropha and in pseudomonas putida.		2001	11777412
relationships within the proteobacteria of plant pathogenic acidovorax species and subspecies, burkholderia species, and herbaspirillum rubrisubalbicans by sequence analysis of 16s rdna, numerical analysis and determinative tests.	sequence data for 16s rdna of the type strains of acidovorax avenae subsp. avenae, a. avenae subsp. cattleyae, a. avenae subsp. citrulli, a. konjaci and herbaspirillum rubrisubalbicans were compared with genbank library accessions of burkholderia spp., comamonas sp., ralstonia solanacearum and variovorax sp. maximum parsimony analysis produced two clusters: 1. acidovorax spp., comamonas sp., and variovorax sp. (all in the comamonadaceae), and 2. burkholderia spp., ralstonia solanacearum, and her ...	2001	11827206
rapid identification of ralstonia eutropha strain ch34 using monoclonal antibodies.	ralstonia eutropha strain ch34 (formerly alcaligenes eutrophus ch34) is an aerobic gram-negative and facultative chemolithotrophic bacteria with plasmid-bound resistance to heavy metals. the presence of ralstonia eutropha strain ch34 is an indication of environmental heavy metals pollution. the major purpose of this work was to produce monoclonal antibodies (mabs) against the metal transport outer membrane proteins. in this way, bacteria outer membranes, grown with or without iron, were purified ...	2001	11839250
[cloning and sequencing of the gene encoding esterase esta from ralstonia eutropha ch34].	an esterase-positive clone was isolated by screening a genomic library of ralstonia eutropha ch34 constructed in escherichia coli s17-1 with top agar containing alpha-naphtyl acetate and fast blue rr. a gne encoding esterase activity, esta was subcloned from this clone. nucleotide sequencing of esta showed that it was a 825 bp open reading frame, encoding an esterase esta, composed of 275 amino acids with a predicted molecular mass of 30,785 d. homology analysis revealed that esta exhibited sign ...	2001	12552903
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 ...	2001	11278039
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 ...	2001	11278570
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 ...	2001	11281329
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 ...	2001	11282658