| 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 |
| cloning of an intracellular poly[d(-)-3-hydroxybutyrate] depolymerase gene from ralstonia eutropha h16 and characterization of the gene product. | an intracellular poly[d(-)-3-hydroxybutyrate] (phb) depolymerase gene (phaz) has been cloned from ralstonia eutropha h16 by the shotgun method, sequenced, and characterized. nucleotide sequence analysis of a 2.3-kbp dna fragment revealed an open reading frame of 1,260 bp, encoding a protein of 419 amino acids with a predicted molecular mass of 47,316 da. the crude extract of escherichia coli containing the phb depolymerase gene digested artificial amorphous phb granules and released mainly oligo ... | 2001 | 11114905 |
| hrpb2 and hrpf from xanthomonas are type iii-secreted proteins and essential for pathogenicity and recognition by the host plant. | the interaction between the plant pathogen xanthomonas campestris pv. vesicatoria and its host plants is controlled by hrp genes (hypersensitive reaction and pathogenicity), which encode a type iii protein secretion system. among type iii-secreted proteins are avirulence proteins, effectors involved in the induction of plant defence reactions. using non-polar mutants, we investigated the role of 12 hrp genes in the secretion of the avirulence protein avrbs3 from x. c. pv. vesicatoria and a heter ... | 2000 | 11115117 |
| simultaneous detection of gfp-marked moraxella sp. g21r and lux-marked ralstonia eutrophas h850lr using most-probable-number method. | the green fluorescent protein encoded by gfp gene and the luminescent protein encoded by luxab genes were used as markers to detect p-nitrophenol (pnp)-degrading moraxella sp. g21r and polychlorinated biphenyl (pcb)-degrading ralstonia eutrophas h850lr cells, respectively, in mixed liquid cultures and in soil samples using a most-probable-number (mpn) assay. population estimates for both gfp-marked g21r and lux-marked h850lr by using mpn assays were similar to viable colony counts. the mpn assay ... | 2000 | 11121604 |
| ralstonia solanacearum--a plant pathogen in touch with its host. | | 2000 | 11121751 |
| occurrence of tn4371-related mobile elements and sequences in (chloro)biphenyl-degrading bacteria. | tn4371, a 55-kb transposable element involved in the degradation and biphenyl or 4-chlorobiphenyl identified in ralstonia eutropha a5, displays a modular structure including a phage-like integrase gene (int), a pseudomonas-like (chloro)biphenyl catabolic gene cluster (bph), and rp4- and ti-plasmid-like transfer genes (trb) (c. merlin, d. springael, and a. toussaint, plasmid 41:40-54, 1999). southern blot hybridization was used to examine the presence of different regions of tn4371 in a collectio ... | 2001 | 11133426 |
| nag genes of ralstonia (formerly pseudomonas) sp. strain u2 encoding enzymes for gentisate catabolism. | ralstonia sp. strain u2 metabolizes naphthalene via gentisate to central metabolites. we have cloned and sequenced a 21.6-kb region spanning the nag genes. upstream of the pathway genes are nagy, homologous to chemotaxis proteins, and nagr, a regulatory gene of the lysr family. divergently transcribed from nagr are the genes for conversion of naphthalene to gentisate (nagaaghabacadbfcqed) (s. l. fuenmayor, m. wild, a. l. boyes, and p. a. williams, j. bacteriol. 180:2522-2530, 1998), which except ... | 2001 | 11133965 |
| ralstonia paucula (formerly cdc group iv c-2): unsuccessful strain differentiation with pcr-based methods, study of the 16s-23s spacer of the rrna operon, and comparison with other ralstonia species (r. eutropha, r. pickettii, r. gilardii, and r. solanacearum). | ralstonia paucula (formerly cdc group iv c-2) can cause serious human infections. confronted in 1995 with five cases of nosocomial bacteremia, we found that pulsed-field gel electrophoresis could not distinguish between the isolates and that randomly amplified polymorphic dna analysis was poorly discriminatory. in this study, we used pcr-ribotyping and pcr-restriction fragment length polymorphism analysis of the spacer 16s-23s ribosomal dna (rdna); both methods were unable to differentiate r. pa ... | 2001 | 11136807 |
| methanogen and bacterial diversity and distribution in deep gas hydrate sediments from the cascadia margin as revealed by 16s rrna molecular analysis. | the microbial community of a deep (to 234 m below the sea floor) sediment gas hydrate deposit (cascadia margin ocean drilling program site 889/890, leg 146) was analysed for the first time by molecular genetic techniques. both bacterial and methanogen diversity were determined by phylogenetic analysis of ribosomal dna sequences. high molecular mass dna, indicative of active bacteria, was present in all of the samples. ribosomal rna genes were amplified from extracted dna extracted from sediment ... | 2001 | 11137602 |
| bioremediation of polychlorinated biphenyl-contaminated soil using carvone and surfactant-grown bacteria. | partial bioremediation of polychlorinated biphenyl (pcb)-contaminated soil was achieved by repeated applications of pcb-degrading bacteria and a surfactant applied 34 times over an 18-week period. two bacterial species, arthrobacter sp. strain b1b and ralstonia eutrophus h850, were induced for pcb degradation by carvone and salicylic acid, respectively, and were complementary for the removal of different pcb congeners. a variety of application strategies was examined utilizing a surfactant, sorb ... | 2000 | 11152078 |
| mobilization of selenite by ralstonia metallidurans ch34. | ralstonia metallidurans ch34 (formerly alcaligenes eutrophus ch34) is a soil bacterium characteristic of metal-contaminated biotopes, as it is able to grow in the presence of a variety of heavy metals. r. metallidurans ch34 is reported now to resist up to 6 mm selenite and to reduce selenite to elemental red selenium as shown by extended x-ray absorption fine-structure analysis. growth kinetics analysis suggests an adaptation of the cells to the selenite stress during the lag-phase period. depen ... | 2001 | 11157242 |
| nickel-resistance-based minitransposons: new tools for genetic manipulation of environmental bacteria. | the ncc and nre nickel resistance determinants from ralstonia eutropha-like strain 31a were used to construct mini-tn5 transposons. broad host expression of nickel resistance was observed for the nre minitransposons in members of the alpha, beta, and gamma subclasses of the proteobacteria, while the ncc minitransposons expressed nickel resistance only in r. eutropha-like strains. | 2001 | 11157282 |
| sera from adult patients with cystic fibrosis contain antibodies to pseudomonas aeruginosa type iii apparatus. | expression of type iii proteins of pseudomonas aeruginosa in patients with cystic fibrosis (cf) was investigated by measuring the immune response against components of the type iii pathway. twenty-three of the 33 sera contained antibodies against pcrv, a protein involved in translocation of type iii cytotoxins into eukaryotic cells, and 11 of 33 had antibodies against exos, while most cf sera contained antibodies against popb and popd, components of the type iii apparatus. these data indicate th ... | 2001 | 11160019 |
| identification of a new class of biopolymer: bacterial synthesis of a sulfur-containing polymer with thioester linkages. | this is the first report on the biosynthesis of a hitherto unknown, sulfur-containing polyester and also the first report on a bacterial polymer containing sulfur in the backbone. the gram-negative polyhydroxyalkanoate (pha)-accumulating bacterium ralstonia eutropha synthesized a copolymer of 3-hydroxybutyrate and 3-mercaptopropionate, poly(3hb-co-3mp), when 3-mercaptopropionic acid or 3,3'-thiodipropionic acid was provided as carbon source in addition to fructose or gluconic acid under nitrogen ... | 2001 | 11160796 |
| resistance to bacterial wilt in somatic hybrids between solanum tuberosum and solanum phureja. | somatic hybrid plants were produced after protoplast electrofusion between a dihaploid potato, cv. bf15, and a wild tuber-bearing relative, solanum phureja, with a view to transferring bacterial wilt resistance into potato lines. a total of ten putative hybrids were selected. dna analysis using flow cytometry revealed that six were tetraploids, two mixoploids, one amphiploid and one octoploid. in the greenhouse, the putative hybrids exhibited strong vigor and were morphologically intermediate, i ... | 2000 | 11164589 |
| source of resistance against ralstonia solanacearum in fertile somatic hybrids of eggplant (solanum melongena l.) with solanum aethiopicum l. | solanum aethiopicum is reported to carry resistance to bacterial wilt disease caused by ralstonia solanacearum, which is one of the most important diseases of eggplant (solanum melongena). these two species can sexually be crossed but the fertility of their progeny is very low. in order to transfer the resistance and improve the fertility, somatic hybrids between s. melongena cv. dourga and two groups of s. aethiopicum were produced by electrical fusion of mesophyll protoplasts. thirty hybrid pl ... | 2001 | 11164602 |
| mechanistic studies on class i polyhydroxybutyrate (phb) synthase from ralstonia eutropha: class i and iii synthases share a similar catalytic mechanism. | the class i and iii polyhydroxybutyrate (phb) synthases from ralstonia eutropha and chromatium vinosum, respectively, catalyze the polymerization of beta-hydroxybutyryl-coenzyme a (hbcoa) to generate phb. these synthases have different molecular weights, subunit composition, and kinetic properties. recent studies with the c. vinosum synthase suggested that it is structurally homologous to bacterial lipases and allowed identification of active site residues important for catalysis [jia, y., kappo ... | 2001 | 11170423 |
| 100th american society for microbiology annual meeting. | the 100th asm annual meeting, attended by approximately 10,000 delegates, continued the trend of concentrating on bacteria and antibacterial therapy, mixed with genomics and a diverse number of additional topics. of the various marketable drug classes, the quinolones received attention with respect to susceptibility studies and several drug comparison studies. new marketable drugs were also of interest, especially given the reservoirs of resistance presented by several speakers. drugs in develop ... | 2000 | 11203475 |
| catalytic and molecular properties of the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase from ralstonia eutropha strain bo. | the quinohemoprotein tetrahydrofurfuryl alcohol dehydrogenase (thfa-dh) from ralstonia eutropha strain bo was investigated for its catalytic properties. the apparent k(cat)/k(m) and k(i) values for several substrates were determined using ferricyanide as an artificial electron acceptor. the highest catalytic efficiency was obtained with n-pentanol exhibiting a k(cat)/k(m) value of 788 x 10(4) m(-1) s(-1). the enzyme showed substrate inhibition kinetics for most of the alcohols and aldehydes inve ... | 2001 | 11222593 |
| phenotypic methods for determining genomovar status of the burkholderia cepacia complex. | recent taxonomic advances have demonstrated that burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) collectively referred to as the b. cepacia complex, all of which may cause infections among cystic fibrosis patients and other vulnerable individuals. thus, it is important for clinical microbiologists to be able to differentiate genomovars. prior to this study, 361 b. cepacia complex isolates and 51 isolates easily confused with b. cepacia complex ... | 2001 | 11230429 |
| 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 |
| new insight into the role of the phap phasin of ralstonia eutropha in promoting synthesis of polyhydroxybutyrate. | phasins are proteins that are proposed to play important roles in polyhydroxyalkanoate synthesis and granule formation. here the phasin phap of ralstonia eutropha has been analyzed with regard to its role in the synthesis of polyhydroxybutyrate (phb). purified recombinant phap, antibodies against phap, and an r. eutropha phap deletion strain have been generated for this analysis. studies with the phap deletion strain show that phap must accumulate to high levels in order to play its normal role ... | 2001 | 11244085 |
| phylogenetic analysis of the succession of bacterial communities in the great south bay (long island). | bacterial community composition and succession were examined over the course of the summer season in the great south bay, long island, ny, usa, using a 16s rdna clone library approach. there was a progression of changes in dominant species in the libraries during the summer of 1997. the july library had several groups dominant, the sar407 relatives of the alpha-proteobacteria (24%) and the sar86 (18%), sulfur-oxidizing symbiont relatives (8%) of the gamma-proteobacteria, and unidentified cytopha ... | 2001 | 11248393 |
| 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 |
| 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 |
| rapid phenotypic change and diversification of a soil bacterium during 1000 generations of experimental evolution. | evolutionary pathways open to even relatively simple organisms, such as bacteria, may lead to complex and unpredictable phenotypic changes, both adaptive and non-adaptive. the evolutionary pathways taken by 18 populations of ralstonia strain tfd41 while they evolved in defined environments for 1000 generations were examined. twelve populations evolved in liquid media, while six others evolved on agar surfaces. phenotypic analyses of these derived populations identified some changes that were con ... | 2001 | 11283295 |
| [avoidable "fever of unknown origin" due to ralstonia pickettii bacteremia]. | ralstonia pickettii bacteraemia from the atrial part of a ventriculo-atrial shunt was diagnosed as the cause of recurring febrile episodes with systemic toxicity in a 38-year old female. a prior neurosurgical resection of intracerebral cavernoma was complicated by postoperative recurrent meningitis with this non-fermenting gram-negative rod, due to an intra-operative contamination of a in situ shunt, from which only the intracerebral part of the ventriculo-atriostomy had been removed, following ... | 2001 | 11307484 |
| burkholderia cepacia genomovar vi, a new member of the burkholderia cepacia complex isolated from cystic fibrosis patients. | a polyphasic taxonomic study was performed on 23 strains isolated from cystic fibrosis (cf) patients in the usa. these strains were tentatively identified as burkholderia cepacia, burkholderia vietnamiensis and burkholderia or ralstonia sp. using biochemical tests and 16s rdna-based pcr assays. visual comparison of protein profiles indicated that they belonged to a single new group ('group 13'). the polyphasic taxonomic data showed that 18 of these strains represent a new member of the b. cepaci ... | 2001 | 11321071 |
| classification of ralstonia pickettii biovar 3/'thomasii' strains (pickett 1994) and of new isolates related to nosocomial recurrent meningitis as ralstonia mannitolytica sp. nov. | strains isolated independently from two patients could be recognized as ralstonia pickettii biovar 3/'thomasii'. the 16s rdna sequences of these strains and two other strains of r. pickettii biovar 3/'thomasii' clustered at less than 98% similarity versus all other described ralstonia species and at less than 97 % versus the two other r. pickettii biovars. the separate species status of r. pickettii biovar 3/'thomasii' was confirmed by dna-dna hybridization, indicating less than 60% dna homology ... | 2001 | 11321101 |
| analysis of mutational effects of a polyhydroxybutyrate (phb) polymerase on bacterial phb accumulation using an in vivo assay system. | polymerase is a central enzyme involved in the biosynthesis of polyhydroxybutyrate (phb), a well-known bacterial biodegradable polyester. in this study, we have established an in vivo assay system to analyze mutational effects of ralstonia eutropha polymerase (termed phbc(re)) on the level of phb accumulation in recombinant strains of escherichia coli. this in vitro evolution system consists of a polymerase chain reaction-mediated random mutagenesis and two assay procedures, a plate assay using ... | 2001 | 11325555 |
| heterologous expression of the acyl-acyl carrier protein thioesterase gene from the plant umbellularia californica mediates polyhydroxyalkanoate biosynthesis in recombinant escherichia coli. | the acyl-acyl carrier protein (acp) thioesterase cdna from the plant umbellularia californica was functionally expressed in various recombinant escherichia coli strains in order to establish a new metabolic route toward medium-chain-length polyhydroxyalkanoate (pha(mcl)) biosynthesis from non-related carbon sources. coexpression of the pha synthase genes from ralstonia eutropha and pseudomonas aeruginosa, or only the pha synthase gene from p. aeruginosa, respectively, showed pha(mcl) accumulatio ... | 2001 | 11330715 |
| a calorimetrically based method to convert toxic compounds into poly-3-hydroxybutyrate and to determine the efficiency and velocity of conversion. | a fed-batch method for converting toxic substrates into poly-3-hydroxybutyrate is presented. the method involves a series of batch-growth processes, regulated by adding small amounts of carbon substrate, during the course of which the concentration of the nitrogen source decreases and controls the distribution of the substrate-carbon assimilated. the addition of carbon substrate is controlled, and the small changes that occur in the growth pattern are interpreted using high-resolution reaction c ... | 2001 | 11330720 |
| metabolic flux modeling of detoxification of acetic acid by ralstonia eutropha at slightly alkaline ph levels. | ralstonia eutropha grows on and produces polyhydroxyalkanoates (phas) from fermentation acids. acetic acid, one major organic acid from acidogenesis of organic wastes, has an inhibitory effect on the bacterium at slightly alkaline ph (6 g hac/l at ph 8). the tolerance of r. eutropha to acetate, however, was increased significantly up to 15 g/l at the slightly alkaline ph level with high cell mass concentration. a metabolic cell model with five fluxes is proposed to depict the detoxification mech ... | 2001 | 11344450 |
| a microbial biosensor to predict bioavailable nickel in soil and its transfer to plants. | ralstonia eutropha strain ae2515 was constructed and optimised to serve as a whole-cell biosensor for the detection of bioavailable concentrations of ni2+ and co2+ in soil samples. strain ae2515 is a ralstonia eutropha ch34 derivative containing pmol1550, in which the cnryxh regulatory genes are transcriptionally fused to the bioluminescent luxcdabe reporter system. strain ae2515 was standardised for its specific responses to co2+ and ni2+. the detection limits for ae2515 were 0.1 microm ni2+ an ... | 2001 | 11351758 |
| metabolic and kinetic analysis of poly(3-hydroxybutyrate) production by recombinant escherichia coli. | a quantitatively repeatable protocol was developed for poly(3-hydroxybutyrate) (phb) production by escherichia coli xl1-blue (psyl107). two constant-glucose fed-batch fermentations of duration 25 h were carried out in a 5-l bioreactor, with the measured oxygen volumetric mass-transfer coefficient (k(l)a) held constant at 1.1 min(-1). all major consumption and production rates were quantified. the intracellular concentration profiles of acetyl-coa (300 to 600 microg x g rcm(-1)) and 3-hydroxybuty ... | 2001 | 11353412 |
| characterization of (r/s)-mecoprop [2-(2-methyl-4-chlorophenoxy) propionic acid]-degrading alcaligenes sp.cs1 and ralstonia sp. cs2 isolated from agricultural soils. | the herbicide mecoprop [2-(2-methyl-4-chlorophenoxy) propionic acid] is widely applied to corn fields in order to control broad-leaved weeds. however, it is often detected in groundwater where it can be a persistent contaminant. two mecoprop-degrading bacterial strains were isolated from agricultural soils through their capability to degrade (r/s)-mecoprop rapidly. 16s rdna sequencing of the isolates demonstrated that one was closely related to the genera alcaligenes sp. (designated cs1) and the ... | 2001 | 11359515 |
| 2,4-dichlorophenoxyacetate/alpha-ketoglutarate dioxygenases from burkholderia cepacia 2a and ralstonia eutropha jmp134. | 2,4-dichlorophenoxyacetate (2,4-d)/alpha-ketoglutarate (alpha-kg) dioxygenase has been purified to apparent homogeneity from burkholderia cepacia strain 2a, which utilizes 2,4-d as sole carbon source. the enzyme required ferrous ions, and was a homodimer composed of subunits having an mr of approximately 32,000. the reaction catalysed consumed one mol each of 2,4-d, alpha-kg and dioxygen, with the production of one mol each of succinate, 2,4-dichlorophenol and glyoxylate. maximum activity was ex ... | 2001 | 11368091 |
| the chlorocatechol degradative genes, tfdt-cdef, of burkholderia sp. strain nk8 are involved in chlorobenzoate degradation and induced by chlorobenzoates and chlorocatechols. | the modified-ortho pathway genes responsible for the degradation of chlorocatechols produced from 3- and 4-chlorobenzoate in burkholderia sp. nk8 were cloned and analyzed. the five genes predicted to encode a lysr-type transcriptional regulator, chlorocatechol 1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase were designated tfdt, tfdc, tfdd, tfde, and tfdf, respectively since they show the highest similarity to the corresponding genes of the chl ... | 2001 | 11368916 |
| generation of pcr-based dna fragments for specific detection of streptomyces saraceticus n45. | streptomyces saraceticus strain n45, a saprophytic gram-positive bacteria, has been shown to harbor high chitinase activity. due to its potential use in biological control, the cloning of chitinase genes and the development of methods to quickly and precisely detect its presence have become necessary. in this study, pcr-based random amplified polymorphic dna (rapd) and pcr strategies were used to amplify random dna fragments from the genome of s. saraceticus n45. three amplified dna fragments, 4 ... | 2001 | 11370759 |
| bacteriophage p4282, a parasite of ralstonia solanacearum, encodes a bacteriolytic protein important for lytic infection of its host. | to enhance bacterial wilt resistance in tobacco expressing a foreign protein, we isolated the bacteriolytic gene from a bacteriophage that infects ralstonia solanacearum. the bacteriolytic protein of phage p4282 isolated in tochigi prefecture was purified from a lysate of r. solanacearum m4s cells infected with the phage, and its bacteriolytic activity was assayed by following the decrease in the turbidity of suspensions of r. solancacearum m4s cells. the molecular weight of the bacteriolytic pr ... | 2001 | 11370877 |
| ralstonia solanacearum needs motility for invasive virulence on tomato. | ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. by examining bacteria from the xylem vessels of infected plants, we found that r. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. to determine the role of pathogen motility in this disease, we cloned, charac ... | 2001 | 11371523 |
| transposon mutagenesis in purple sulfur photosynthetic bacteria: identification of hypf, encoding a protein capable of processing [nife] hydrogenases in alpha, beta, and gamma subdivisions of the proteobacteria. | a random transposon-based mutagenesis system was optimized for the purple sulfur phototrophic bacterium thiocapsa roseopersicina bbs. screening for hydrogenase-deficient phenotypes resulted in the isolation of six independent mutants in a mini-tn5 library. one of the mutations was in a gene showing high amino acid sequence similarity to hypf proteins in other organisms. inactivation of hydrogen uptake activity in the hypf-deficient mutant resulted in a dramatic increase in the hydrogen evolution ... | 2001 | 11375153 |
| continuous production of poly-3-hydroxybutyrate by ralstonia eutropha in a two-stage culture system. | poly-3-hydroxybutyrate (phb) is mainly accumulated by ralstonia eutropha under unbalanced growth conditions, which limits its production in batch or fed-batch modes. the continuous production of phb was investigated in a two-stage continuous culture system. the first-stage produced cell mass giving the maximal cell dry weight of 27.1 g l(-1) at 0.21 h(-1) of dilution rate. high specific cell growth rate results in the decrease of phb synthesis under glucose-limited and nitrogen-rich conditions i ... | 2001 | 11377765 |
| frankia kb5 possesses a hydrogenase immunologically related to membrane-bound. | the immunological relationship of the hydrogenase in frankia kb5 to hydrogenases in other microorganisms was investigated using antisera raised against holo-[nife]-hydrogenases isolated from alcaligenes latus, azotobacter vinelandii, ralstonia eutropha, and the small and large hydrogenase subunits from bradyrhizobium japonicum. the antisera raised against the a. latus, r. eutropha, and b. japonicum (large subunit) polypeptides were found to recognize two polypeptides, corresponding to the unproc ... | 2001 | 11381338 |
| surfactant protein interactions with neutral and acidic phospholipid films. | the captive bubble tensiometer was employed to study interactions of phospholipid (pl) mixtures of dipalmitoylphosphatidylcholine (dppc) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (popc) or 1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (popg) at 50 microg/ml with physiological levels of the surfactant protein (sp) a sp-b, and sp-c alone and in combination at 37 degrees c. all surfactant proteins enhanced lipid adsorption to equilibrium surface tension (gamma), with sp-c ... | 2001 | 11404266 |
| identification and characterization of a periplasmic nitrate reductase in azospirillum brasilense sp245. | the azospirillum brasilense sp245 napabc genes, encoding nitrate reductase activity, were isolated and sequenced. the derived protein sequences are very similar throughout the whole nap segment to the napabc protein sequences of escherichia coli, pseudomonas sp. g-179, ralstonia eutropha, rhodobacter sphaeroides, and paracoccus denitrificans. based on whole-cell nitrate reductase assays with the artificial electron donors benzyl viologen and methyl viologen, and assays with periplasmic cell-free ... | 2001 | 11409544 |
| effects of 2,2',5,5'-tetrachlorobiphenyl and biphenyl on cell membranes of ralstonia eutropha h850. | the effects of 2,2',5,5'-tetrachlorobiphenyl (tecb), a pcb congener, and biphenyl on the cytoplasmic membranes of ralstonia eutropha h850 were investigated by measuring fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene (dph) as the probe, and determining the cellular fatty acid compositions. tecb significantly affected the membrane of r. eutropha h850 cells grown on fructose by decreasing dph fluorescence polarization. in contrast, the membrane of cells grown on biphenyl showed a con ... | 2001 | 11410343 |
| construction and characterization of a xanthomonas oryzae pv. oryzae bacterial artificial chromosome library. | xanthomonas oryzae pv. oryzae is an important plant pathogen which causes bacterial blight of rice. to facilitate genome studies of this bacterium, we have constructed a bacterial artificial chromosome (bac) library of strain maff 311018. it consisted of 750 clones representing 16 genome equivalents, and had an insert size ranging from 20 to 220 kb with an average size of 107 kb. this library is the first to be constructed from a x. oryzae pv. oryzae strain. the usefulness of this library was de ... | 2001 | 11410350 |
| albibacter methylovorans gen. nov., sp. nov., a novel aerobic, facultatively autotrophic and methylotrophic bacterium that utilizes dichloromethane. | a novel genus, albibacter, with one species, albibacter methylovorans sp. nov., is proposed for a facultatively chemolithotrophic and methylotrophic bacterium (strain dm10t) with the ribulose bisphosphate (rubp) pathway of c1 assimilation. the bacterium is a gram-negative, aerobic, asporogenous, nonmotile, colourless rod that multiplies by binary fission. the organism utilizes dichloromethane, methanol, methylamine, formate and co2/h2, as well as a variety of polycarbon compounds, as carbon and ... | 2001 | 11411673 |
| biodegradation of synthetic and naturally occuring mixtures of mono-cyclic aromatic compounds present in olive mill wastewaters by two aerobic bacteria. | two bacterial strains, ralstonia sp. ld35 and pseudomonas putida dsm 1868, were assayed for their ability to degrade the monocyclic aromatic compounds commonly found in olive mill wastewaters (omws). the goal was to study the possibility of employing the two strains in the removal of these recalcitrant and toxic compounds from the effluents of anaerobic treatment plants fed with omws. at first, the two strains were separately assayed for their ability to degrade a synthetic mixture of nine aroma ... | 2001 | 11414330 |
| accumulation of the phap phasin of ralstonia eutropha is dependent on production of polyhydroxybutyrate in cells. | polyhydroxyalkanoates (phas) are polyoxoesters that are produced by diverse bacteria and that accumulate as intracellular granules. phasins are granule-associated proteins that accumulate to high levels in strains that are producing phas. the accumulation of phasins has been proposed to be dependent on pha production, a model which is now rigorously tested for the phasin phap of ralstonia eutropha. r. eutropha phac pha synthase and phap phasin gene replacement strains were constructed. the strai ... | 2001 | 11418562 |
| isafe1, an isl3 family insertion sequence from acidithiobacillus ferrooxidans atcc 19859. | a 1.3-kb insertion sequence, termed isafe1 (u66426), from acidithiobacillus ferrooxidans atcc 19859 is described. isafe1 exhibits the features of a typical bacterial insertion sequence. it has 26-bp, imperfectly matched, terminal inverted repeats and an open reading frame (orf) that potentially encodes a transposase (tpase) of 404 amino acids (aab07489) with significant similarity to members of the isl3 family of insertion sequences. a potential ribosome-binding site and potential -10 and -35 pr ... | 2001 | 11418574 |
| kinetic analysis on formation of poly(3-hydroxybutyrate) from acetic acid by ralstonia eutropha under chemically defined conditions. | batch cultures of ralstonia eutropha in chemically defined media with acetic acid (hac) as the sole carbon source were conducted to investigate acetate utilization, formation of poly(3-hydroxybutyrate) (phb) and growth of active biomass (abm) under different carbon to nitrogen (c/n) weight ratios. the specific acetate utilization rate based on abm approached 0.16 g/g abm h(-1), which was not affected very much by the extracellular hac concentration from 1 to 5 g/l, but was affected by the c/n we ... | 2001 | 11420650 |