| dual-bioaugmentation strategy to enhance remediation of cocontaminated soil. | although metals are thought to inhibit the ability of microorganisms to degrade organic pollutants, several microbial mechanisms of resistance to metal are known to exist. this study examined the potential of cadmium-resistant microorganisms to reduce soluble cadmium levels to enhance degradation of 2,4-dichlorophenoxyacetic acid (2,4-d) under conditions of cocontamination. four cadmium-resistant soil microorganisms were examined in this study. resistant up to a cadmium concentration of 275 micr ... | 2001 | 11425743 |
| ralstonia metallidurans ch34 rpon sigma factor and the control of nitrogen metabolism and biphenyl utilization. | ralstonia metallidurans ch34 can use biphenyl as carbon and energy source when provided with the catabolic transposon tn4371. previous results suggested that this property was dependent on the rna polymerase subunit sigma(54). the authors sequenced the ch34 rpon gene and flanking dna and isolated a ch34 rpon-deficient strain. analysis of the sequence revealed a set of features conserved in all rpon genes and flanking dna regions previously analysed in other bacterial species. nevertheless, despi ... | 2001 | 11429471 |
| in vivo detection of the cyclic osmoregulated periplasmic glucan of ralstonia solanacearum by high-resolution magic angle spinning nmr. | we investigate the mobility of the osmoregulated periplasmic glucans of ralstonia solanacearum in the bacterial periplasm through the use of high-resolution (hr) nmr spectroscopy under static and magic angle spinning (mas) conditions. because the nature of periplasm is far from an isotropic aqueous solution, the molecules could be freely diffusing or rather associated to a periplasmic protein, a membrane protein, a lipid, or the peptidoglycan. hr mas nmr spectroscopy leads to more reproducible r ... | 2001 | 11444945 |
| production of poly(3-hydroxybutyrateco-3-hydroxyvalerate) from cottonseed oil and valeric acid in batch culture of raistonia sp. strain jc-64. | a ralstonia sp. strain jc-64 that is capable of accumulating poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (p[3hb-co-3hv]) from cottonseed oil and valeric acid was isolated. by using a high limiting-nitrogen (hln) mineral medium as the medium for the second stage of the fermentation process and by adding the two carbon sources at different times, a range of copolymers with 12-62 mol% of 3hv were produced from a series of hln mineral mediums containing different compositions of cottonseed oil and ... | 2001 | 11456295 |
| a physical map of the megaplasmid phg1, one of three genomic replicons in ralstonia eutropha h16. | we have used pulsed field gel electrophoresis and megabase dna techniques to investigate the basic genomic organization of ralstonia eutropha h16, and to construct a physical map of its indigenous megaplasmid phg1. this gram-negative, soil-dwelling bacterium is a facultative chemolithoautotroph and a denitrifier. in the absence of organic substrates it can grow on h2 as its sole energy source and co2 as its sole source of carbon. under anaerobic conditions it can utilize nitrate as a terminal el ... | 2001 | 11470364 |
| ethanedisulfonate is degraded via sulfoacetaldehyde in ralstonia sp. strain eds1. | aerobic enrichment cultures (11) yielded three cultures able to utilise ethane-1,2-disulfonate as sole source of carbon and energy in salts medium. two pure cultures were obtained and we worked with strain eds1, which was assigned to the genus ralstonia on the basis of its 16s rdna sequence and simple taxonomic tests. strain eds1 utilised at least seven alkane(di)sulfonates, ethane-1,2-disulfonate, taurine, isethionate, sulfoacetate, sulfoacetaldehyde and propane-1,3-disulfonate, as well as meth ... | 2001 | 11479707 |
| hsr203 antisense suppression in tobacco accelerates development of hypersensitive cell death. | activation of the tobacco gene hsr203 is rapid, highly localized, specific for incompatible plant-pathogen interactions, and strongly correlated with programmed cell death occurring in response to diverse pathogens. functional characterization of hsr203 gene product has shown that hsr203 is a serine hydrolase that displays esterase activity. we show here that transgenic tobacco plants deficient in hsr203 protein exhibit an accelerated hypersensitive response when inoculated with an avirulent str ... | 2001 | 11489189 |
| molecular characterization of a deletion/duplication rearrangement in tfd genes from ralstonia eutropha jmp134(pjp4) that improves growth on 3-chlorobenzoic acid but abolishes growth on 2,4-dichlorophenoxyacetic acid. | ralstonia eutropha jmp134(pjp4) is able to grow on minimal media containing the pollutants 3-chlorobenzoate (3-cb) or 2,4-dichlorophenoxyacetate (2,4-d). tfd genes from the 88 kb plasmid pjp4 encode enzymes involved in the degradation of these compounds. during growth of strain jmp134 in liquid medium containing 3-cb, a derivative strain harbouring a approximately 95 kb plasmid was isolated. this derivative, designated jmp134(pjp4-f3), had an improved ability to grow on 3-cb, but had lost the ab ... | 2001 | 11495991 |
| the methylcitric acid pathway in ralstonia eutropha: new genes identified involved in propionate metabolism. | from ralstonia eutropha hf39 null-allele mutants were created by tn5 mutagenesis and by homologous recombination which were impaired in growth on propionic acid and levulinic acid. from the molecular, physiological and enzymic analysis of these mutants it was concluded that in this bacterium propionic acid is metabolized via the methylcitric acid pathway. the genes encoding enzymes of this pathway are organized in a cluster in the order prpr, prpb, prpc, acnm, orf5 and prpd, with prpr transcribe ... | 2001 | 11495997 |
| comparative study of the relationship between monomer structure and reactivity for two polyhydroxyalkanoate synthases. | using organically synthesized hydroxyalkanoate coenzyme a thioesters, the activities of two short-chain polyhydroxalkanoate (pha) synthases were investigated--ralstonia eutropha pha synthase (a type i pha synthase) and ectothiorhodospira shaposhnikovii pha synthase (a type iii synthase). the results indicate that the two synthases have similar activities towards most of the monomers tested. 3-hydroxybutyryl coa was found to be the most efficient substrate for both synthases. changes in the side- ... | 2001 | 11499920 |
| isolation and characterization of a thermotolerant bacterium ralstonia sp. strain phs1 that degrades benzene, toluene, ethylbenzene, and o-xylene. | a thermotolerant bacterium, designated as phs1, was isolated from a hot spring in pohang, korea, on the basis of its ability to grow on benzene, toluene, ethylbenzene, and xylenes (btex) as a sole carbon source. strain phs1 is a gram-negative, rod-shaped aerobe and grows optimally at 42 degrees c and ph 7.2. according to 16 s rdna analysis, strain phs1 showed highest similarity to ralstonia eutropha (previously named alcaligenes eutrophus). unlike its closest known ralstonia species, however, st ... | 2001 | 11499943 |
| polychlorinated biphenyl degradation activities and hybridization analyses of fifteen aerobic strains isolated from a pcb-contaminated site. | fifteen bacterial strains using biphenyl as sole carbon and energy source, obtained from different positions and depths of a polychlorinated biphenyl (pcb)-contaminated area, were analyzed for their basic metabolic phenotypes and subjected to genomic dna hybridization screening for the presence of well characterized bph operons such as those of pseudomonas pseudoalcaligenes kf707 and rhodococcus globerulus p6. most of the isolates belonged to the gamma-subdivision (pseudomonas stutzeri, p. pluti ... | 2001 | 11501677 |
| molecular characterization and heterologous expression of hypcd, the first two [nife] hydrogenase accessory genes of thermococcus litoralis. | the hypcd genes, encoding the counterparts of mesophilic proteins involved in the maturation of [nife] hydrogenases, were isolated from the hyperthermophilic archaeon thermococcus litoralis. the deduced gene products showed 30-40% identity to the corresponding mesophilic proteins. hypc and hypd were synthesized by the t7 expression system. heterologous complementation experiments were done in escherichia coli and ralstonia eutropha strains lacking functionally active hypc and hypd genes. only th ... | 2001 | 11511872 |
| quorum-sensing in gram-negative bacteria. | it has become increasingly and widely recognised that bacteria do not exist as solitary cells, but are colonial organisms that exploit elaborate systems of intercellular communication to facilitate their adaptation to changing environmental conditions. the languages by which bacteria communicate take the form of chemical signals, excreted from the cells, which can elicit profound physiological changes. many types of signalling molecules, which regulate diverse phenotypes across distant genera, h ... | 2001 | 11524130 |
| the viable but nonculturable state of ralstonia solanacearum may be involved in long-term survival and plant infection. | the role of the dormant-like viable but nonculturable (vbnc) condition in the etiology of bacterial infection was examined using a plant system. the plant-pathogenic bacterium ralstonia solanacearum was first shown to enter into the vbnc state both in response to cupric sulfate when in a saline solution and when placed in autoclaved soil. to determine if the vbnc condition is related to pathogenesis, the physiological status of bacteria recovered from different regions of inoculated tomato plant ... | 2001 | 11525979 |
| isolation of an insertion sequence from ralstonia solanacearum race 1 and its potential use for strain characterization and detection. | a new insertion sequence (is), is1405, was isolated and characterized from a ralstonia solanacearum race 1 strain by the method of insertional inactivation of the sacb gene. sequence analysis indicated that the is is closely related to the members of is5 family, but the extent of nucleotide sequence identity in 5' and 3' noncoding regions between is1405 and other members of is5 family is only 23 to 31%. nucleotide sequences of these regions were used to design specific oligonucleotide primers fo ... | 2001 | 11525989 |
| transformation of chlorinated benzenes and toluenes by ralstonia sp. strain ps12 teca (tetrachlorobenzene dioxygenase) and tecb (chlorobenzene dihydrodiol dehydrogenase) gene products. | the tecb gene, located downstream of teca and encoding tetrachlorobenzene dioxygenase, in ralstonia sp. strain ps12 was cloned into escherichia coli dh5alpha together with the teca gene. the identity of the tecb gene product as a chlorobenzene dihydrodiol dehydrogenase was verified by transformation into the respective catechols of chlorobenzene, the three isomeric dichlorobenzenes, as well as 1,2,3- and 1,2,4-trichlorobenzenes, all of which are transformed by teca into the respective dihydrodih ... | 2001 | 11526005 |
| identification of strains of alcaligenes and agrobacterium by a polyphasic approach. | the number of stable discriminant biochemical characters is limited in the genera alcaligenes and agrobacterium, whose species are consequently difficult to distinguish from one another by conventional tests. moreover, genomic studies have recently drastically modified the nomenclature of these genera; for example, alcaligenes xylosoxidans was transferred to the genus achromobacter in 1998. twenty-five strains of achromobacter xylosoxidans, three strains of an agrobacterium sp., five strains of ... | 2001 | 11526136 |
| cloning and functional analysis of the pbr lead resistance determinant of ralstonia metallidurans ch34. | the lead resistance operon, pbr, of ralstonia metallidurans (formerly alcaligenes eutrophus) strain ch34 is unique, as it combines functions involved in uptake, efflux, and accumulation of pb(ii). the pbr lead resistance locus contains the following structural resistance genes: (i) pbrt, which encodes a pb(ii) uptake protein; (ii) pbra, which encodes a p-type pb(ii) efflux atpase; (iii) pbrb, which encodes a predicted integral membrane protein of unknown function; and (iv) pbrc, which encodes a ... | 2001 | 11544228 |
| involvement of an unusual mol operon in molybdopterin cofactor biosynthesis in ralstonia eutropha. | in contrast to its parent strain, transposon tn5-mob insertion mutant hb6 of the facultative chemoautotroph ralstonia eutropha was unable to grow organoautotrophically on formate and exhibited no activity of mo-dependent, membrane-bound formate dehydrogenase (m-fdh) when cultivated mixotrophically on fructose plus formate. the activity of another molybdoenzyme, the soluble, nad+-linked formate dehydrogenase which is the key enzyme of formate utilization in r. eutropha, was greatly diminished in ... | 2001 | 11545279 |
| excess sludge reduction in activated sludge processes by integrating biomass alkaline heat treatment. | with new ec regulations, alternative treatment and disposal techniques of the excess sludge produced by activated sludge wastewater treatment plants have to be developed. to decrease activated sludge production yield, microbial cell lysis can be amplified to enhance cryptic growth (biomass growth on lysates). cell breakage techniques (thermal, alkaline and a combination) were studied to generate ralstonia eutropha (strain model) and waste activated sludge lysates and to evaluate their biodegrada ... | 2001 | 11548016 |
| a putative type iii secretion gene cluster is widely distributed in the burkholderia cepacia complex but absent from genomovar i. | using probes constructed from ralstonia solanacearum and burkholderia pseudomallei, putative type iii secretion (tts) genes were identified in burkholderia cepacia j2315 (genomovar iii). a cosmid clone containing dna with homology to five tts genes was sub-cloned and regions were sequenced in order to design oligonucleotides for polymerase chain reaction assays. these indicated that two putative tts genes (bcscq and bcscv) were present in all members of the b. cepacia complex with the exception ... | 2001 | 11557147 |
| a dynamic study and modeling of the formation of polyhydroxyalkanoates combined with treatment of high strength wastewater. | production of biodegradable thermoplastics, polyhydroxyalkanoates (phas), from organic wastes may provide multiple benefits to environmental conservation efforts. in this study, microfiltration-coupled reactors were set up to study the dynamic behavior of a typical pha-producing bacteria, ralstonia eutropha, fed with a real acidic solution from starch acidogenesis in a continuous flow system. the majorfermentation acids (butyric and acetic acids) were utilized by the pha producers at a high conv ... | 2001 | 11563668 |
| class i and iii polyhydroxyalkanoate synthases from ralstonia eutropha and allochromatium vinosum: characterization and substrate specificity studies. | class i and iii polyhydroxyalkanoate (pha) synthases catalyze the conversion of beta-hydroxybutyryl coenzyme a (hbcoa) to polyhydroxybutyrate. the class i pha synthase from ralstonia eutropha has been purified by numerous labs with reported specific activities that vary between 1 and 160 u/mg. an n-terminal (his)6-pha synthase was constructed and purified with specific activity of 40 u/mg. the variable activity is shown to be related to the protein's propensity to aggregate and not to incomplete ... | 2001 | 11566031 |
| [current concepts on the pathogenicity of phytopathogenic bacteria]. | what are the molecular determinants that make a bacterium a plant pathogen? in the last 10-20 years, important progress has been made in answering this question. in the early 20th century soon after the discovery of infectious diseases, the first studies of pathogenicity were undertaken. these early studies relied mostly on biochemistry and led to the discovery of several major pathogenicity determinants, such as toxins and hydrolytic enzymes which govern the production of major disease symptoms ... | 2001 | 11570279 |
| cloning, nucleotide sequencing, and functional analysis of a novel, mobile cluster of biodegradation genes from pseudomonas aeruginosa strain jb2. | we have identified in pseudomonas aeruginosa strain jb2 a novel cluster of mobile genes encoding degradation of hydroxy- and halo-aromatic compounds. nineteen open reading frames were located and, based on sequence similarities, were putatively identified as encoding a ring hydroxylating oxygenase (hybabcd), an atp-binding cassette-type transporter, an extradiol ring-cleavage dioxygenase, transcriptional regulatory proteins, enzymes mediating chlorocatechol degradation, and transposition functio ... | 2001 | 11571162 |
| prevalence of type iii secretion genes in clinical and environmental isolates of pseudomonas aeruginosa. | the type iii secretion system of pseudomonas aeruginosa transports four known effector proteins: exos, exot, exou and exoy. however, the prevalence of the type iii secretion system genes or the effector-encoding genes in clinical and environmental isolates of p. aeruginosa has not been well studied. southern hybridization analyses and pcr were performed on over 100 p. aeruginosa isolates to determine the distribution of these genes. clinical isolates were obtained from urine, endotracheal, blood ... | 2001 | 11577145 |
| novel hemoglobins to enhance microaerobic growth and substrate utilization in escherichia coli. | limited oxygen availability is a prevalent problem in microbial biotechnology. recombinant escherichia coli expressing the hemoglobin from vitreoscilla (vhb) or the flavohemoglobin from ralstonia eutropha (formerly alcaligenes eutrophus) (fhp) demonstrate significantly increased cell growth and productivity under microaerobic conditions. we identify novel bacterial hemoglobin-like proteins and examine if these novel bacterial hemoglobins can elicit positive effects similar to vhb and fhp and if ... | 2001 | 11587567 |
| influence of substrate exposure history on biodegradation in a porous medium. | this study investigates the influence of fluctuating toluene concentrations on aerobic toluene degradation in a sandy porous medium colonized with ralstonia pickettii pko1. column effluent toluene concentrations were found to increase after a temporary decrease in influent toluene concentration. subsequent examination of the spatial gradient of toluene degradative activity in the column suggested that the observed increase in effluent toluene concentrations was attributable to an adverse effect ... | 2001 | 11588828 |
| ralstonia taiwanensis sp. nov., isolated from root nodules of mimosa species and sputum of a cystic fibrosis patient. | a polyphasic taxonomic study, including 16s rdna sequence analysis, dna-dna hybridizations, dna base ratio determinations, amplified 165 rdna restriction analysis, whole-cell protein analyses and extensive biochemical characterization, was conducted to clarify the relationships of eight isolates from root nodules of mimosa species and one isolate from sputum of a cystic fibrosis patient. all nine isolates were classified as a novel ralstonia species, for which the name ralstonia taiwanensis sp. ... | 2001 | 11594603 |
| classification of metal-resistant bacteria from industrial biotopes as ralstonia campinensis sp. nov., ralstonia metallidurans sp. nov. and ralstonia basilensis steinle et al. 1998 emend. | thirty-one heavy-metal-resistant bacteria isolated from industrial biotopes were subjected to polyphasic characterization, including 16s rdna sequence analysis, dna-dna hybridizations, biochemical tests, whole-cell protein and fatty-acid analyses. all strains were shown to belong to the ralstonia branch of the beta-proteobacteria. whole-cell protein profiles and dna-dna hybridizations revealed two clearly distinct groups, showing low similarity to known ralstonia species. these two groups, of 8 ... | 2001 | 11594608 |
| production of catechol from benzoate by the wild strain ralstonia species ba-0323 and characterization of its catechol 1,2-dioxygenase. | ralstonia sp. ba-0323, a wild strain isolated from soil, produced catechol from benzoate and accumulated it outside the cells. the bacterium produced a maximal amount of catechol (1.6 mg/ml) from 3 mg/ml of sodium benzoate in a 20-h growing culture. the conversion rate of benzoate to catechol was 70% on a molar basis. the catechol production by the resting cells increased in the presence of glycerol, and the maximal amount of catechol produced from 3 mg/ml of sodium benzoate reached 1.9 mg/ml at ... | 2001 | 11676005 |
| characterization of the reduction of selenate and tellurite by nitrate reductases. | preliminary studies showed that the periplasmic nitrate reductase (nap) of rhodobacter sphaeroides and the membrane-bound nitrate reductases of escherichia coli are able to reduce selenate and tellurite in vitro with benzyl viologen as an electron donor. in the present study, we found that this is a general feature of denitrifiers. both the periplasmic and membrane-bound nitrate reductases of ralstonia eutropha, paracoccus denitrificans, and paracoccus pantotrophus can utilize potassium selenate ... | 2001 | 11679335 |
| poly(3-hydroxybutyrate) synthesis genes in azotobacter sp. strain fa8. | genes responsible for the synthesis of poly(3-hydroxybutyrate) (phb) in azotobacter sp. fa8 were cloned and analyzed. a phb polymerase gene (phbc) was found downstream from genes coding for beta-ketothiolase (phba) and acetoacetyl-coenzyme a reductase (phbb). a phb synthase mutant was obtained by gene inactivation and used for genetic studies. the phbc gene from this strain was introduced into ralstonia eutropha phb-4 (phbc-negative mutant), and the recombinant accumulated phb when either glucos ... | 2001 | 11679365 |
| effects of ecological factors on the survival and physiology of ralstonia solanacearum bv. 2 in irrigation water. | the fate of ralstonia solanacearum bv. 2, the causative agent of brown rot in potato, in aquatic habitats of temperate climate regions is still poorly understood. in this study, the population dynamics and the physiological response of r. solanacearum bv. 2 were tested in sterile pure water and in agricultural drainage water obtained from waterways near potato cropping fields in the netherlands. the behaviour of five different biovar 2 isolates in drainage water at 20 degrees c was very similar ... | 2001 | 11683466 |
| microbial production of poly-d-3-hydroxybutyrate from co2. | this short review covers the biotechnological aspects of the production of poly-d-3-hydroxybutyric acid, p(3hb), from h2, o2 and co2 by autotrophic culture of the hydrogen-oxidizing bacterium, ralstonia eutropha. considering the efficiency of utilization of a gas mixture as substrate, a practical fermentation process using r. eutropha for the mass production of p(3hb) from co2 should be designed on the basis of a recycled-gas, closed-circuit culture system. also, maintaining the o2 concentration ... | 2001 | 11693935 |
| 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 |
| tropical plant pathology: at home and abroad. | i first describe my introduction to plant pathology and early experiences with employment, the environment, diseases, pests, and various plant pathologists. then i recount a decade of stimulating studies at the university of minnesota and the route i followed to a career in international agriculture with the rockefeller foundation in colombia and later at cornell university. my appreciation for and knowledge of traditional farmers and sustainable agriculture occurred as a slow awakening. comment ... | 2001 | 11701856 |
| assessment of a simple, non-toxic alamar blue cell survival assay to monitor tomato cell viability. | the alamar blue (ab) assay, which incorporates a medox indicator that changes colour or fluorescence in response to metabolic activity, is commonly used to assess quantitatively the viability and/or proliferation of mammalian cells and micro-organisms. in this study the ab assay was adapted for the determination of the viability of plant cells. cell suspension cultures of tomato, lycopersicon esculentum, l., with differing viabilities, served as the experimental model for a comparison of the ab ... | 2001 | 11705263 |
| [ralstonia pickettii pneumonia in an inmunocompetent adult]. | | 2001 | 11707228 |
| 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 |
| 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 |
| 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 |
| involvement of hyp gene products in maturation of the h(2)-sensing [nife] hydrogenase of ralstonia eutropha. | the biosynthesis of [nife] hydrogenases is a complex process that requires the function of the hyp proteins hypa, hypb, hypc, hypd, hype, hypf, and hypx for assembly of the h(2)-activating [nife] site. in this study we examined the maturation of the regulatory hydrogenase (rh) of ralstonia eutropha. the rh is a h(2)-sensing [nife] hydrogenase and is required as a constituent of a signal transduction chain for the expression of two energy-linked [nife] hydrogenases. here we demonstrate that the r ... | 2001 | 11717266 |
| nad(p)-dependent aldehyde dehydrogenases induced during growth of ralstonia eutropha strain bo on tetrahydrofurfuryl alcohol. | different aldehyde dehydrogenases (aldhs) were formed during growth of ralstonia eutropha bo on tetrahydrofurfuryl alcohol (thfa). one of these enzymes, aldh 4, was purified and characterized as a homodimer containing no prosthetic groups, showing a strong substrate inhibition, and having an n-terminal sequence similar to those of various nad(p)-dependent aldhs. the conversion rate of thfa by the quinohemoprotein thfa dehydrogenase was increased by aldh 4. | 2001 | 11717302 |
| identification of pandoraea species by 16s ribosomal dna-based pcr assays. | the recently described genus pandoraea contains five named species (pandoraea apista, pandoraea pulmonicola, pandoraea pnomenusa, pandoraea sputorum, and pandoraea norimbergensis) and four unnamed genomospecies. pandoraea spp. have mainly been recovered from the respiratory tracts of cystic fibrosis (cf) patients. accurate genus- and species-level identification by routine clinical microbiology methods is difficult, and differentiation from burkholderia cepacia complex organisms may be especiall ... | 2001 | 11724860 |
| case of catheter sepsis with ralstonia gilardii in a child with acute lymphoblastic leukemia. | acute lymphoblastic leukemia was diagnosed in a 7-year-old girl. two months after insertion of a central venous catheter, she developed fever and complained of headache and abdominal pain. physical examination revealed no focus of infection. a gram-negative nonfermenting bacillus was recurrently cultured from blood. extensive biochemical testing and 16s ribosomal dna sequencing led to the identification of ralstonia gilardii. | 2001 | 11724891 |
| one case each of recurrent meningitis and hemoperitoneum infection with ralstonia mannitolilytica. | two clinical cases of infection with ralstonia mannitolilytica are described: a recurrent meningitis on an implanted intraventricular catheter and an infected hemoperitoneum as a complication of a cholangiocarcinoma. the strains were first misidentified as pseudomonas fluorescens and burkholderia cepacia. further testing lead to the identification as ralstonia pickettii biovar 3/"thomasii," which was recently shown to represent a separate species, r. mannitolilytica (list editor n. weiss, int. j ... | 2001 | 11724893 |
| a polyphasic approach for studying the interaction between ralstonia solanacearum and potential control agents in the tomato phytosphere. | ralstonia solanacearum biovar 2, the causative agent of brown rot in potato, has been responsible for large crop losses in northwest europe during the last decade. knowledge on the ecological behaviour of r. solanacearum and its antagonists is required to develop sound procedures for its control and eradication in infested fields.a polyphasic approach was used to study the invasion of plants by a selected r. solanacearum biovar 2 strain, denoted 1609, either or not in combination with the antago ... | 2002 | 11733083 |
| 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 |
| the ralstonia eutropha phar protein couples synthesis of the phap phasin to the presence of polyhydroxybutyrate in cells and promotes polyhydroxybutyrate production. | polyhydroxyalkanoates (phas) are polyoxoesters that are produced by many bacteria and that accumulate as intracellular granules. phasins (phap) are proteins that accumulate during pha synthesis, bind pha granules, and promote further pha synthesis. interestingly, phap accumulation seems to be strictly dependent on pha synthesis, which is catalyzed by the phac pha synthase. here we have tested the effect of the ralstonia eutropha phar protein on the regulation of phap accumulation. r. eutropha st ... | 2002 | 11741844 |
| 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 |
| phylogeny and functional expression of ribulose 1,5-bisphosphate carboxylase/oxygenase from the autotrophic ammonia-oxidizing bacterium nitrosospira sp. isolate 40ki. | the autotrophic ammonia-oxidizing bacteria (aob), which play an important role in the global nitrogen cycle, assimilate co(2) by using ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco). here we describe the first detailed study of rubisco (cbb) genes and proteins from the aob. the cbbls genes from nitrosospira sp. isolate 40ki were cloned and sequenced. partial sequences of the rubisco large subunit (cbbl) from 13 other aob belonging to the beta and gamma subgroups of the class proteobac ... | 2002 | 11751824 |
| novel 2,4-dichlorophenoxyacetic acid degradation genes from oligotrophic bradyrhizobium sp. strain hw13 isolated from a pristine environment. | the tfd genes of ralstonia eutropha jmp134 are the only well-characterized set of genes responsible for 2,4-dichlorophenoxyacetic acid (2,4-d) degradation among 2,4-d-degrading bacteria. a new family of 2,4-d degradation genes, cadrabkc, was cloned and characterized from bradyrhizobium sp. strain hw13, a strain that was isolated from a buried hawaiian soil that has never experienced anthropogenic chemicals. the cadr gene was inferred to encode an arac/xyls type of transcriptional regulator from ... | 2002 | 11751829 |
| chimeric vitreoscilla hemoglobin (vhb) carrying a flavoreductase domain relieves nitrosative stress in escherichia coli: new insight into the functional role of vhb. | dimeric hemoglobin (vhb) from the bacterium vitreoscilla sp. strain c1 displays 30 to 53% sequence identity with the heme-binding domain of flavohemoglobins (flavohbs) and exhibits the presence of potential sites for the interaction with its fad/nadh reductase partner. the intersubunit contact region of vhb indicates a small interface between two monomers of the homodimer, suggesting that the vhb dimers may dissociate easily. gel filtration chromatography of vhb exhibited a 25 to 30% monomeric p ... | 2002 | 11772621 |
| identification of the 2-methylcitrate pathway involved in the catabolism of propionate in the polyhydroxyalkanoate-producing strain burkholderia sacchari ipt101(t) and analysis of a mutant accumulating a copolyester with higher 3-hydroxyvalerate content. | burkholderia sacchari ipt101(t) induced the formation of 2-methylcitrate synthase and 2-methylisocitrate lyase when it was cultivated in the presence of propionic acid. the prp locus of b. sacchari ipt101(t) is required for utilization of propionic acid as a sole carbon source and is relevant for incorporation of 3-hydroxyvalerate (3hv) into copolyesters, and it was cloned and sequenced. five genes (prpr, prpb, prpc, acnm, and orf5) exhibited identity to genes located in the prp loci of other gr ... | 2002 | 11772636 |
| monitoring of ralstonia eutropha kt1 in groundwater in an experimental bioaugmentation field by in situ pcr. | ralstonia eutropha kt1, which degrades trichloroethylene, was injected into the aquifer after activation with toluene, and then the number of bacteria was monitored by in situ pcr targeting the phenol hydroxylase gene and by fluorescent in situ hybridization (fish) targeting 16s rrna. before injection of the bacterial suspension, the total concentration of bacteria in the groundwater was approximately 3 x 10(5) cells/ml and the amount of ralstonia and bacteria carrying the phenol hydroxylase gen ... | 2002 | 11772654 |
| 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 |
| expression of a functional nad-reducing [nife] hydrogenase from the gram-positive rhodococcus opacus in the gram-negative ralstonia eutropha. | the actinomycete rhodococcus opacus mr11 harbors a bidirectional nad-reducing [nife] hydrogenase (sh). this cytoplasmic enzyme is composed of two heterodimeric modules which catalyze distinct enzymatic activities. the hydrogenase moiety mediates h(2):benzyl viologen oxidoreductase activity and the fmn-containing diaphorase module displays nadh:benzyl viologen oxidoreductase activity. the sh of rh. opacus resembles [nife] hydrogenases present in strains of the proteobacterium ralstonia eutropha a ... | 2002 | 11807565 |
| characterization of the norb gene, encoding nitric oxide reductase, in the nondenitrifying cyanobacterium synechocystis sp. strain pcc6803. | a norb gene encoding a putative nitric oxide reductase is present in the genome of the nondenitrifying cyanobacterium synechocystis sp. strain pcc6803. the gene product belongs to the quinol-oxidizing single-subunit class of nitric oxide reductases, discovered recently in the denitrifier ralstonia eutropha. heterologous complementation of a nitric oxide reductase-negative mutant of r. eutropha with norb from synechocystis restored nitric oxide reductase activity. with reduced menadione as the el ... | 2002 | 11823206 |
| chemotaxis of ralstonia eutropha jmp134(pjp4) to the herbicide 2,4-dichlorophenoxyacetate. | ralstonia eutropha jmp134(pjp4) and several other species of motile bacteria can degrade the herbicide 2,4-dichlorophenoxyacetate (2,4-d), but it was not known if bacteria could sense and swim towards 2,4-d by the process of chemotaxis. wild-type r. eutropha cells were chemotactically attracted to 2,4-d in swarm plate assays and qualitative capillary assays. the chemotactic response was induced by growth with 2,4-d and depended on the presence of the catabolic plasmid pjp4, which harbors the tfd ... | 2002 | 11823246 |
| genome sequence of the plant pathogen ralstonia solanacearum. | ralstonia solanacearum is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. it is a model system for the dissection of molecular determinants governing pathogenicity. we present here the complete genome sequence and its analysis of strain gmi1000. the 5.8-megabase (mb) genome is organized into two replicons: a 3.7-mb chromosome and a 2.1-mb megaplasmid. both replicons have a mosaic structure providing evidence for the acquisition of genes throu ... | 2002 | 11823852 |
| molecular characterization of the poly(3-hydroxybutyrate) (phb) synthase from ralstonia eutropha: in vitro evolution, site-specific mutagenesis and development of a phb synthase protein model. | a threading model of the ralstonia eutropha polyhydroxyalkanoate (pha) synthase was developed based on the homology to the burkholderia glumae lipase, whose structure has been resolved by x-ray analysis. the lid-like structure in the model was discussed. in this study, various r. eutropha pha synthase mutants were generated employing random as well as site-specific mutagenesis. four permissive mutants (double and triple mutations) were obtained from single gene shuffling, which showed reduced ac ... | 2002 | 11825620 |
| 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 |
| endotoxin levels in steam and reservoirs of table-top steam sterilizers. | to document endotoxin levels in "statim" cassette sterilizer reservoirs and in steam delivered to the cassette in the unwrapped instrument cycle. to document endotoxin levels in sterilizer reservoir water using different management protocols. | 2002 | 11828908 |
| 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 |
| ralstonia pickettii bacteraemia in a cord blood transplant recipient. | a seven-year old boy with acute lymphoblastic leukemia underwent an hla mismatched cord blood transplant. he developed grade 2 mucositis requiring morphine infusion and grade 3-4 hyperacute graft-versus-host disease affecting the skin, gastrointestinal tract, and liver requiring pulse methylprednisolone. on days 21, 23, and 24 post-transplant, blood culture obtained through the central line and periphery were positive for ralstonia pickettii. the same strain (with the same biochemical profile an ... | 2002 | 11841049 |
| resistance to ralstonia solanacearum in arabidopsis thaliana is conferred by the recessive rrs1-r gene, a member of a novel family of resistance genes. | the identification of two arabidopsis thaliana genes involved in determining recessive resistance to several strains of the causal agent of bacterial wilt, ralstonia solanacearum, is reported. dominant (rrs1-s) and recessive (rrs1-r) alleles from susceptible and resistant accessions encode highly similar predicted proteins differing in length and which present a novel structure combining domains found in plant toll-il-1 receptor-nucleotide binding site-leucin-rich repeat resistance proteins and ... | 2002 | 11842188 |
| 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 |
| characterization of microbial polythioesters: physical properties of novel copolymers synthesized by ralstonia eutropha. | various samples of polythioesters with different contents of 3-mercaptopropionic acid (3mp) or 3-mercaptobutyric acid (3mb) as one comonomer and with 3-hydroxybutyric acid (3hb) as the second constituent were produced by cultivating cells of ralstonia eutropha strain h16 in mineral salts medium containing 3mp or 3mb plus gluconate as carbon sources. fermentations were done also at the 30-l scale. the various samples were cast as films from chloroform and the following were recorded: melting poin ... | 2002 | 11866569 |
| formation of short chain length/medium chain length polyhydroxyalkanoate copolymers by fatty acid beta-oxidation inhibited ralstonia eutropha. | ralstonia eutropha has been considered as a bacterium, incorporating hydroxyalkanoates of less than six carbons only into polyhydroxyalkanoates (phas). cells of the wild type cultivated with sodium octanoate as the carbon source in the presence of the fatty acid beta-oxidation inhibitor sodium acrylate synthesized phas composed of the medium chain length hydroxyalkanoates (3ha(mcl)) 3-hydroxyhexanoate (3hhx) and 3-hydroxyoctanoate (3ho) as well as of 3-hydroxybutyrate and 3-hydroxyproprionate as ... | 2002 | 11866575 |
| long pcr-amplified rdna for pcr-rflp- and rep-pcr-based approaches to recognize closely related microbial species. | long pcr was used to amplify a 5-kb fragment of the bacterial ribosomal operon (16s-intergenic spacer region (isr)-23s) from several ralstonia eutropha strains (16s rdna sequence similarity: 97-99%). due to the large product size, amplicons from the different strains could be distinguished using restriction enzyme fragment length polymorphisms (rflp) and repetitive pcr analysis (rep-pcr) with the primer 1492r. these methods may prove useful in differentiating other bacterial strains with highly ... | 2002 | 11869797 |
| salicylate 5-hydroxylase from ralstonia sp. strain u2: a monooxygenase with close relationships to and shared electron transport proteins with naphthalene dioxygenase. | the genes from the oxygenase cluster nagaaghabacad of naphthalene-degrading ralstonia sp. strain u2 were cloned and overexpressed. salicylate 5-hydroxylase (s5h) activity, converting salicylate to gentisate, was present in vitro only in the single extract of cells with overexpressed nagaaghab or in a mixture of three cell extracts containing, respectively, naggh (the oxygenase components), nagaa (ferredoxin reductase), and nagab (ferredoxin). each of the three extracts required for s5h activity ... | 2002 | 11872705 |
| molecular detection and diversity of polycyclic aromatic hydrocarbon-degrading bacteria isolated from geographically diverse sites. | nineteen polycyclic aromatic hydrocarbon (pah)-degrading bacteria were isolated from environmental samples in kuwait, indonesia, thailand, and japan by enrichment with either naphthalene or phenanthrene as a sole carbon source. sequence analyses of the 16-s rrna gene indicated that at least seven genera (ralstonia, sphingomonas, burkholderia, pseudomonas, comamonas, flavobacterium, and bacillus) were present in this collection. determination of the ability of the isolates to use pah and its pres ... | 2002 | 11876413 |
| a signal transfer system through three compartments transduces the plant cell contact-dependent signal controlling ralstonia solanacearum hrp genes. | ralstonia solanacearum hrp genes encode a type iii secretion system required for disease development in host plants and for hypersensitive response elicitation on non-hosts. hrp genes are expressed in the presence of plant cells through the hrpb regulator. this activation, which requires physical interaction between the bacteria and the plant cell, is sensed by the outer membrane receptor prha. prha transduces the plant cell contact-dependent signal through a complex regulatory cascade integrate ... | 2002 | 11876423 |
| cloning, characterization and comparison of the pseudomonas mendocina polyhydroxyalkanoate synthases phac1 and phac2. | this study describes a comparison of the polyhydroxyalkanoate (pha) synthases phac1 and phac2 of pseudomonas mendocina. the p mendocina pha gene locus, encoding two pha synthase genes [phac1pm and phac2pm flanking a pha depolymerase gene (phaz)], was cloned, and the nucleotide sequences of phac1pm (1,677 bp), phaz (1,034 bp), and phac2pm (1,680 bp) were determined. the amino acid sequences deduced from phac1pm and phac2pm showed highest similarities to the corresponding pha synthases from other ... | 2002 | 11878309 |
| characterization of the zat1p zinc transporter from arabidopsis thaliana in microbial model organisms and reconstituted proteoliposomes. | the zat1p zinc transporter from arabidopsis thaliana (l.) heynh. is a member of the cation diffusion facilitator (cdf) protein family. when heterologously expressed in escherichia coli, zat1p bound zinc in a metal blot. binding of zinc occurred mainly to the hydrophilic amino acid region from h182 to h232. a zat1p/zat1p*delta(m1-i25) protein mixture was purified and reconstituted into proteoliposomes. uptake of zinc into the proteoliposomes did not require a proton gradient across the liposomal ... | 2002 | 11882948 |
| characterization of tdt genes for the degradation of tricyclic diterpenes by pseudomonas diterpeniphila a19-6a. | resin acids are tricyclic diterpenes that are toxic to aquatic life when released in high concentrations in pulp mill effluents. these naturally formed organic acids are readily degraded by bacteria and fungi; nevertheless, many of the mechanisms involved are still unknown. we report the localization, cloning, and sequencing of genes for abietane degradation (9.18 kb; designated tdt (tricyclic diterpene) lrsabcd) from the gamma-proteobacterium pseudomonas diterpeniphila a19-6a. using gene knocko ... | 2002 | 11888163 |
| snakin-2, an antimicrobial peptide from potato whose gene is locally induced by wounding and responds to pathogen infection. | the peptide snakin-2 (stsn2) has been isolated from potato (solanum tuberosum cv jaerla) tubers and found to be active (ec(50) = 1-20 microm) against fungal and bacterial plant pathogens. it causes a rapid aggregation of both gram-positive and gram-negative bacteria. the corresponding stsn2 cdna encodes a signal sequence followed by a 15-residue acidic sequence that precedes the mature stsn2 peptide, which is basic (isoelectric point = 9.16) and 66 amino acid residues long (molecular weight of 7 ... | 2002 | 11891250 |
| identification and characterization of poly-3-hydroxybutyrate granule-associated protein, pga12 and pga16 in zoogloea ramigera i-16-m. | poly-3-hydroxybutyrate (phb) granules of zoogloea ramigera i-16-m contained two major phb granule-associated proteins (pga12 and pga16) as revealed by sodium dodecyl sulfate-polyacrylamide gel elecrophoresis. n-terminal amino acid sequences of these proteins were determined. the genes encoding these proteins were cloned and sequenced. the structural genes of pga12 and pga16 were 351 and 447 bp long, which encode polypeptides with deduced molecular masses of 12.3 and 16.0 kda, respectively. pga12 ... | 2002 | 11893394 |
| effect of increased pha synthase activity on polyhydroxyalkanoates biosynthesis in synechocystis sp. pcc6803. | polyhydroxyalkanoate (pha) synthase activity in synechocystis sp. pcc6803 was increased two-fold by introducing the pha biosynthetic genes of ralstonia eutropha. the resulting recombinant synechocystis sp. pcc6803 strain was subjected to conditions that favor pha accumulation and the effects of various carbon sources were studied. in addition, the fine structure of both wild-type and recombinant synechocystis sp. pcc6803 was examined using freeze-fracture electron microscopy technique. the pha g ... | 2002 | 11911900 |
| analysis of bacteria contaminating ultrapure water in industrial systems. | bacterial populations inhabiting ultrapure water (upw) systems were investigated. the analyzed upw systems included pilot scale, bench scale, and full size upw plants employed in the semiconductor and other industries. bacteria present in the polishing loop of the upw systems were enumerated by both plate counts and epifluorescence microscopy. assessment of bacterial presence in upw by epifluorescence microscopy (cyanotolyl tetrazolium chloride [ctc] and dapi [4',6'-diamidino-2-phenylindole] sta ... | 2002 | 11916667 |
| development and characterization of a green fluorescent protein-based bacterial biosensor for bioavailable toluene and related compounds. | a green fluorescent protein-based pseudomonas fluorescens strain a506 biosensor was constructed and characterized for its potential to measure benzene, toluene, ethylbenzene, and related compounds in aqueous solutions. the biosensor is based on a plasmid carrying the toluene-benzene utilization (tbu) pathway transcriptional activator tbut from ralstonia pickettii pko1 and a transcriptional fusion of its promoter ptbua1 with a promoterless gfp gene on a broad-host-range promoter probe vector. tbu ... | 2002 | 11916719 |
| the hydrogen-sensing apparatus in ralstonia eutropha. | molecular hydrogen is widely used by microorganisms as a source of energy. one of the best studied aerobic hydrogen oxidizers, the beta-proteobacterium ralstonia eutropha (formerly alcaligenes eutrophus), harbors two distinct [nife]-hydrogenases which catalyze the heterolytic cleavage of h2 into 2h+ and 2e-. the genes encoding the hydrogenase subunits are arranged in two large operons together with accessory and regulatory genes involved in hydrogenase biosynthesis. both operons are transcribed ... | 2002 | 11931556 |
| nitric oxide signaling and no dependent transcriptional control in bacterial denitrification by members of the fnr-crp regulator family. | bacterial denitrification transforms nitrate to dinitrogen. the process is expressed facultatively in response to environmental conditions. around 50 components make up the denitrification apparatus and its assembly pathways. we are beginning to understand how exogenous signals provided by oxygen and n oxides are processed for activating the underlying gene programs. key signals are provided by nitrate, nitric oxide, and a low oxygen tension. in the genus pseudomonas the nitrate signal is proces ... | 2002 | 11931559 |
| [chemical characterisation and serological activity of lipopolysaccharides of ralstonia solanacearum]. | lipopolysaccharides (lps) of 8 strains of ralstonia solanacearum (767, 4157, 5712, 7944, 7945, 7955, 8089 and 8110) characterized by different types of the structures of o-specific polysaccharide chains have been investigated. the elisa and elisa-inhibition methods were used to investigate the extent of antigenic activity of the presented lps with respect to the obtained polyclonal o-antisera to the above strains. when analyzing the results obtained the strains were divided into five serogroups ... | 2002 | 11944345 |
| cell-specific transgene expression from a widely transcribed promoter using cre/lox in mice. | mice carrying two or more transgenes are used frequently to evaluate oncogene interactions during carcinogenesis. however, neoplastic transformation typically results in reduced expression both of differentiation-specific genes and of transgenes that use their promoters. in contrast, the more widely expressed metallothionein (mt) gene remains expressed at a high level in certain neoplasms, including those developing in pancreas. we have developed a system to maintain high-level, tissue-specific ... | 2002 | 11948915 |
| a molybdenum-containing dehydrogenase catalyzing an unusual 2-hydroxylation of nicotinic acid. | an enzyme of ralstonia/ burkholderia strain dsm 6920 catalyzing the initial hydroxylation of 6-methylnicotinic acid at position 2 was purified to apparent homogeneity. it also catalyzed the unusual conversion of nicotinic acid to 2-hydroxynicotinic acid and was therefore designated as nicotinic acid dehydrogenase (ndh). native ndh had a molecular mass of 280 kda and was composed of subunits of 75, 30 and 16 kda. it contained molybdenum, iron, acid-labile sulfur and fad in a ratio of 1.6:7.3:8.0: ... | 2002 | 11956743 |
| autotrophic synthesis of polyhydroxyalkanoates by the bacteria ralstonia eutropha in the presence of carbon monoxide. | it has been found that the carbon monoxide (co)-resistant strain of the hydrogen bacteria ralstonia eutropha b5786 is able to synthesise polyhydroxyalkanoates (phas) in the presence of co under autotrophic conditions. this strain, grown on model gas mixtures containing 5-25% co (v/v), accumulates up to 70-75% (of absolutely dry matter) pha, without significant variation in the yield coefficient on hydrogen. no suppression of the activities of the key enzymes of pha synthesis ( beta-ketothiolase, ... | 2002 | 11956753 |
| community shifts in a seeded 3-chlorobenzoate degrading membrane biofilm reactor: indications for involvement of in situ horizontal transfer of the clc-element from inoculum to contaminant bacteria. | pseudomonas putida bn210, carrying the self- transferable clc-element encoding degradation of 3-chlorobenzoate on the chromosome, was used as inoculum in different membrane biofilm reactors treating 3-chlorobenzoate-contaminated model wastewater. analysis of the bacterial population in the effluent and in the biofilm showed the loss of bn210 beyond detection from the reactors and the appearance of several novel 3-chlorobenzoate mineralizing bacteria mainly belonging to the beta-proteobacteria. i ... | 2002 | 11972616 |