| properties of a novel intracellular poly(3-hydroxybutyrate) depolymerase with high specific activity (phazd) in wautersia eutropha h16. | a novel intracellular poly(3-hydroxybutyrate) (phb) depolymerase (phazd) of wautersia eutropha (formerly ralstonia eutropha) h16 which shows similarity with the catalytic domain of the extracellular phb depolymerase in ralstonia pickettii t1 was identified. the positions of the catalytic triad (ser190-asp266-his330) and oxyanion hole (his108) in the amino acid sequence of phazd deduced from the nucleotide sequence roughly accorded with those of the extracellular phb depolymerase of r. pickettii ... | 2005 | 16199568 |
| integrated recombinant protein expression and purification platform based on ralstonia eutropha. | protein purification of recombinant proteins constitutes a significant cost of biomanufacturing and various efforts have been directed at developing more efficient purification methods. we describe a protein purification scheme wherein ralstonia eutropha is used to produce its own "affinity matrix," thereby eliminating the need for external chromatographic purification steps. this approach is based on the specific interaction of phasin proteins with granules of the intracellular polymer polyhydr ... | 2005 | 16204482 |
| organization of polyhydroxyalkanoate synthase for in vitro polymerization as revealed by atomic force microscopy. | individual polyhydroxyalkanoate synthase molecules from ralstonia eutropha (phacre) were directly visualized on highly oriented pyrolytic graphite (hopg) by atomic force microscopy (afm). phacre molecule was observed as a spherical particle of 2.9 +/- 0.4 nm in height and 28 +/- 4 nm in width. in vitro polymerization reaction on hopg was carried out for 5 min by reacting the phacre molecules with (r)-3-hydroxybutyryl-coa monomers. the reaction product was then observed after the removal of water ... | 2005 | 16208629 |
| surface active properties of bacterial strains isolated from petroleum hydrocarbon-bioremediated soil. | two bacterial strains identified as ralstonia picketti (bp 20) and alcaligenes piechaudii (czor l-1b) were isolated from petroleum hydrocarbon-contaminated soil following bioremediation treatment. the surface active properties, e.g. surface tension, emulsification and foamability of their culture filtrates were evaluated. bacterial cell-surface hydrophobicity (bah) as measured by analyzing cell affinity towards aliphatic and aromatic compounds was also determinated. the bacteria grew in liquid c ... | 2005 | 16209110 |
| repeated batch cultivation of ralstonia eutropha for poly (beta-hydroxybutyrate) production. | batch cultivation of ralstonia eutropha nrrl b14690 attained 21 g biomass l(-1) and 9.4 g poly(beta-hydroxybutyrate) l(-1) (0.45 g phb g(-1 )dry wt(-1)) in 60 h. repeated batch operation (empty-and-fill protocol) to remove 20% (v/v) of the culture broth and to supplement an equal volume of fresh media resulted in 49 g biomass l(-1) and 25 g phb l(-1) (0.51 g phb g(-1) dry wt(-1)) with an overall productivity of 0.42 g phb l(-1 )h(-1 )in 67 h. in the two cycles of repeated batch fermentation ther ... | 2005 | 16215857 |
| biosynthesis and characterization of poly(3-hydroxybutyrate-co-3- hydroxyhexanoate) from palm oil products in a wautersia eutropha mutant. | palm kernel oil, palm olein, crude palm oil and palm acid oil were used for the synthesis of poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) [p(3hb-co-3hhx)] by a mutant strain of wautersia eutropha (formerly ralstonia eutropha) harboring the aeromonas caviae polyhydroxyalkanoate (pha) synthase gene. palm kernel oil was an excellent carbon source for the production of cell biomass and p(3hb-co-3hhx). about 87% (w/w) of the cell dry weight as p(3hb-co-3hhx) was obtained using 5 g palm kernel oil/l ... | 2005 | 16215858 |
| the rhizosphere as a reservoir for opportunistic human pathogenic bacteria. | during the last years, the number of human infections caused by opportunistic pathogens has increased dramatically. one natural reservoir of opportunistic pathogens is the rhizosphere, the zone around roots that is influenced by the plant. due to a high content of nutrients, this habitat is a 'microbial hot-spot', where bacterial abundances including those with strong antagonistic traits are enhanced. various bacterial genera, including burkholderia, enterobacter, herbaspirillum, ochrobactrum, p ... | 2005 | 16232283 |
| cloning and sequence analysis of hydroxyquinol 1,2-dioxygenase gene in 2,4,6-trichlorophenol-degrading ralstonia pickettii dtp0602 and characterization of its product. | a gene encoding hydroxyquinol 1,2-dioxygenase was cloned from 2,4,6-trichlorophenol-degrading ralstonia (pseudomonas) pickettii strain dtp0602. cell-free extracts of escherichia coli containing a cloned 1.4-kb stui-xhoi dna fragment of r. pickettii dtp0602 hydroxyquinol 1,2-dioxygenase converted hydroxyquinol into maleylacetate and also degraded 6-chlorohydroxyquinol. the 1.4-kb dna fragment contained one open reading frame (designated hadc) composed of 948 nucleotides. the molecular mass of 34, ... | 1999 | 16232466 |
| effect of modifying metabolic network on poly-3-hydroxybutyrate biosynthesis in recombinant escherichia coli. | the regulatory mechanism for poly-3-hydroxybutyrate (phb) biosynthesis in recombinant escherichia coli is markedly different from that of ralstonia eutropha (formerly, alcaligenes eutrophus) since the former efficiently synthesizes phb during growth without any nutrient limitation. to analyze how the central metabolic pathways should be balanced with pathways necessary for cell growth and phb formation, a stoichiometric model was developed to predict the theoretical maximum phb production capaci ... | 1999 | 16232536 |
| constitutive trichloroethylene degradation led by tac promoter chromosomally integrated upstream of phenol hydroxylase genes of ralstonia sp. kn1 and its nucleotide sequence analysis. | ralstonia sp. kn1-10a is a strain capable of degrading trichloroethylene (tce) constitutively due to the tac promoter (ptac) integrated upstream of the phenol hydroxylase genes (phy) in its chromosome. the expression of ptac was analyzed using luxab of vibrio harveyi as a reporter. after determining the nucleotide sequence of phyabcde required for tce degradation, a luxab-encoding fragment was integrated downstream of phye by homologous recombination in strain kn1-10a, obtaining strain kn1-10a-l ... | 2000 | 16232697 |
| effect of controlling lactate concentration and periodic change in do concentration on fermentation characteristics of a mixed culture of lactobacillus delbrueckii and ralstonia eutropha for phb production. | a mixed culture system was considered in the present research where sugars such as glucose were converted to lactate by lactobacillus delbrueckii and the lactate was converted to poly beta-hydroxybutyrate (phb) by ralstonia eutropha in one fermentor. based on the experimental studies on the effect of lactate concentration on the cell growth of both microorganisms, the lactate concentration was controlled at less than 5 g/l using an on-line enzymatic lactate and glucose sensors with the fia (flow ... | 2000 | 16232753 |
| regulating the molar fraction of 4-hydroxybutyrate in poly(3-hydroxybutyrate-4-hydroxybutyrate) biosynthesis by ralstonia eutropha using propionate as a stimulator. | the regulation of the molar fraction of 4-hydroxybutyrate (4-hb) in the poly(3-hydroxybutyrate-4-hydroxybutyrate) [p(3hb-4hb)] biosynthesis by ralstonia eutropha (formerly alcaligenes eutrophus) was attempted by the supplemental addition of propionate. the molar fraction of 4-hb in p(3hb-4hb) was increased significantly from 12.3 to 51.8 mol% by the addition of a small amount of propionate along with gamma-butyrolactone commonly used as a precursor for the biosynthesis of p(3hb-4hb). the mechani ... | 2000 | 16232763 |
| trichloroethylene degradation by ralstonia sp. kn1-10a constitutively expressing phenol hydroxylase: transformation products, nadh limitation, and product toxicity. | ralstonia sp. kn1-10a, which was constructed by inserting the tac promoter upstream of the phenol hydroxylase (ph) gene in the chromosomal dna of the wild-type strain, ralstonia sp. kn1, is a useful recombinant strain for eliminating trichloroethylene (tce) from contaminated sites because it exhibits constitutive tce oxidation activity. during tce degradation by ralstonia sp. kn1-10a, noxious chlorinated compounds, such as dichloroacetic acid, trichloroacetic acid, 2,2,2-trichloroethanol, and ch ... | 2000 | 16232774 |
| utilization of oxidative pressure for enhanced production of poly-beta-hydroxybutyrate and poly(3-hydroxybutyrate-3-hydroxyvalerate) in ralstonia eutropha. | ralstonia eutropha was cultivated under oxidative conditions in the presence of hydrogen peroxide and methyl viologen to stimulate the flux of nadph to the pha biosynthesis pathway. the effects of oxidants on the biosynthesis of poly-beta-hydroxybutyrate(phb) and poly(3-hydroxybutyrate-3-hydroxyvalerate)[p(3hb-3hv)] were investigated. the biosynthesis rate and concentrations of phb and its copolymer p(3hb-3hv) increased significantly under the oxidative pressure of methyl viologen, meanwhile, th ... | 2000 | 16232855 |
| development of a novel method for feeding a mixture of l-lactic acid and acetic acid in fed-batch culture of ralstonia eutropha for poly-d-3-hydroxybutyrate production. | fermentative production of poly-d-3-hydroxybutyrate [p(3hb)] from a mixture of l-lactic acid and acetic acid by ralstonia eutropha was investigated. for fed-batch culture with cell density, it is necessary to control the concentration of these organic acids in the culture medium below the inhibitory level for cell growth. therefore, a novel feeding method, termed the computer-controlled ph-stat substrate feeding method, was developed using the rate of increase of the ph (ph-increasing rate) of t ... | 2001 | 16233037 |
| amplification of the nadph-related genes zwf and gnd for the oddball biosynthesis of phb in an e. coli transformant harboring a cloned phbcab operon. | nadph, a major reducing power in microorganisms, is mostly generated from the pentose phosphate (pp) pathway by glucose-6-phosphate dehydrogenase (g6pdh) and 6-phosphogluconate dehydrogenase (6pgdh) expressed by the zwf and gnd genes, respectively. the characteristics of these two genes in escherichia coli were compared after their re-introduction into the parent strain for over-expression. zwf encoding g6pdh increased the level of nadph 3 folds compared to gnd encoding 6pgdh. an excess of nadph ... | 2002 | 16233247 |
| cloning of an intracellular d(-)-3-hydroxybutyrate-oligomer hydrolase gene from ralstonia eutropha h16 and identification of the active site serine residue by site-directed mutagenesis. | an intracellular d(-)-3-hydroxybutyrate (3hb)-oligomer hydrolase gene from ralstonia eutropha (formerly alcaligenes eutrophus) h16 was cloned, sequenced, and characterized. as a hybridization probe to screen restriction digests of chromosomal dna, an extracellular 3hb-oligomer hydrolase gene from ralstonia pickettii strain (formerly pseudomonas sp. strain) a1 was used. a specific hybridization signal was obtained and a 6.5-kbp smai fragment was cloned in an escherichia coli phagemid vector. the ... | 2002 | 16233278 |
| isolation and characterization of bacillus sp. int005 accumulating polyhydroxyalkanoate (pha) from gas field soil. | a gram-positive bacterium (designated strain int005) that accumulated polyhydroxyalkanoate (pha) was isolated from gas field soil. from its morphological and physiological properties and the partial nucleotide sequence (about 500 bp) of its 16s rdna, it was suggested that strain int005 was similar to several species of the genus bacillus. we confirmed that strain int005 is a bacillus sp. the pha productivities of strain int005 were higher than those of bacillus megaterium and ralstonia eutropha ... | 2003 | 16233370 |
| enzyme-catalyzed poly(3-hydroxybutyrate) synthesis from acetate with coa recycling and nadph regeneration in vitro. | we established a novel enzyme-catalyzed poly(3-hydroxybutyrate) [p(3hb)] synthesis system capable of recycling coa on the basis of the p(3hb) biosynthetic pathway in ralstonia eutropha. the system includes purified beta-ketothiolase (phaa), nadph-dependent acetoacetyl-coa reductase (phab), pha synthase (phac), acetyl-coa synthetase (acs) and glucose dehydrogenase (gdh). in this system, acetyl-coa was synthesized from acetate and coa by acs and atp, and then two molecules of acetyl-coa were conde ... | 2003 | 16233416 |
| catalytic triad of intracellular poly(3-hydroxybutyrate) depolymerase (phaz1) in ralstonia eutropha h16. | the amino acid sequence of an intracellular poly[d(-)-3-hydroxybutyrate] (phb) depolymerase (phaz1) from ralstonia eutropha h16 was compared with the sequences of various proteins using the blast search. it showed a number of matches including with intracellular phb depolymerases, conserved hypothetical proteins, and phb synthases. from an alignment of these proteins, we constructed nine mutants: c87a, s118a, h120q, c183a, c183s, d355a, d356a, c370a, and h388q. the c183a, d355a, and h388q mutant ... | 2003 | 16233560 |
| biochemical and genetic characterization of a d(-)-3-hydroxybutyrate dehydrogenase from acidovorax sp. strain sa1. | d(-)-3-hydroxybutyrate dehydrogenase (bdh; ec 1.1.1.30) from a poly(d(-)-3-hydroxybutyrate) (phb) degrading bacterium, acidovorax sp. sa1, was purified using toyopearl deae-650m, red-sepharose cl-4b, and q sepharose ff. the molecular mass of the enzyme was estimated as 27 kda by sds-page and 110 kda by gel filtration. the gene encoding bdh was cloned and sequenced, and expressed in escherichia coli. the gene product was purified in two steps with a high yield. the n-terminal amino acid sequence ... | 2004 | 16233594 |
| ralstonia associated with vapotherm oxygen delivery device--united states, 2005. | in august 2005, a health-care facility in pennsylvania reported the occurrence of ralstonia spp. in six patients aged 21 days to 8 years to the philadelphia department of health and cdc. preliminary laboratory and epidemiologic investigation identified the vapotherm 2000i oxygen delivery device (vapotherm inc., stevensville, maryland) as an associated risk factor for recovery of the organism from blood and respiratory tract samples. although the source of ralstonia has not yet been identified, v ... | 2005 | 16237377 |
| correlation between solid-state structures and enzymatic degradability of cocrystallized blends. | solid-state structures and enzymatic degradability have been investigated for cocrystallized blends between poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [phbv] and poly(3-hydroxybutyrate-co-3-hydroxypropionate) [phbp]. from wide-angle x-ray diffraction patterns, small-angle x-ray scattering data, and the comparison of the enzymatic degradability of these blends, the solid-state structures of phbv/phbp blend samples, in which the phbv component has higher isothermal crystal growth rate (g) value ... | 2005 | 16245274 |
| [cloning and characterization of an harpin-encoding gene from xanthomonas axonopodis pv. glycines required for hypersensitive response on nonhost plant tobacco]. | an hpa1 gene was cloned into an expression vector, pet30a(+), from the genomic dna of xanthomonas axonopodis pv. glycines (xag), the causal agent of soybean bacterial pustule, with degenerated primers by polymerase amplification reaction (pcr). the gene product was extracted from the conjugate (bhr-3) of bl21 (des) with the recombined vector phr3 after the engineering strain was induced by iptg in lb medium. the sds-page gel showed that the gene product was 15.1kd. the product was heat-stable (1 ... | 2005 | 16245857 |
| [cloning and analysis of genes encoding 2-naphthoate monooxygenase and nadh:flavin oxidoreductase]. | in burkholderia sp. jt1500, a key step of 2-naphthoate biodegradation pathway is carried out by 2-naphthoate monooxygenase (nmo) in which 2-naphthoate is oxidized to 1-hydroxy-2-naphthoate. a gene cluster of 4.8kb from burkholderia sp. jt1500 was cloned and sequenced, four open reading frames named orfb, orfc, orfd and orfa were identified in this region. sequence alignment showed that orfa had a high homology of nucleotide acid composition to monooxygenase genes from both japonicum usda 110 and ... | 2005 | 16245870 |
| production and purification of self-assembling peptides in ralstonia eutropha. | self-assembling peptides have emerged as an attractive scaffold material for tissue engineering, yet the expense associated with solid phase chemical synthesis has limited their broad use. in addition, the fidelity of chemical synthesis constrains the length of polypeptides that can be produced homogeneously by this method. template-derived biosynthesis by recombinant dna technology may overcome both of these problems. however, recovery of polypeptides from recombinant protein expression systems ... | 2006 | 16249097 |
| biodegradation of dichloromethane by the polyvinyl alcohol-immobilized methylotrophic bacterium ralstonia metallidurans pd11. | a dichloromethane (dcm)-degrading bacterium, ralstonia metallidurans pd11 nbrc 101272, was immobilized in a polyvinyl alcohol (pva) gel to use in a bioreactor for dcm treatment. after 4-month incubation of pva gel beads with r. metallidurans pd11 and dcm in a mineral salt medium, the cells were tightly packed in the mesh of the gel. forty beads of the gel in 10 ml of a batch system model showed effective activity degrading 500 and 1,000 mg l(-1) dcm within 2 and 3 h, respectively. although reduc ... | 2006 | 16249875 |
| [characterization and identification of ralstonia solanacearum by ion-exchange chromatography]. | ralstonia solanacearum, a widely distributed and economically important plant pathogen, was characterized by ion-exchange chromatography (iec). ralstonia solanacearum was chromatographed on a toyopearl superq-650 c column (200 mm x 4. 6 mm i. d. ) with gradient elution by a (0.02 mol/l piperazidine-chlorhydric acid buffer (ph 8.0) ) and b (a + 1 mol/l nacl). the pure culture of r. solanacearum was separated into three fractions on a superq-650 c column. they were found all belong to r. solanacea ... | 2005 | 16250457 |
| enzymatic recovery and purification of polyhydroxybutyrate produced by ralstonia eutropha. | polyhydroxybutyrate (phb) is the most studied among a wide variety of polyhydroxyalkanoates, bacterial biodegradable polymers known as potential substitutes for conventional plastics. this work aimed at evaluating the use of enzymes to recover and purify the phb produced by ralstonia eutropha dsm545. screening experiments allowed the selection of trypsin, bromelain and lysozyme among six enzymes, based on their efficiency in lysing cells of a non-phb producing r. eutropha strain. then, process c ... | 2006 | 16253372 |
| differential staining of western blots of human secreted glycoproteins from serum, milk, saliva, and seminal fluid using lectins displaying diverse sugar specificities. | human milk, serum, saliva, and seminal fluid glycoproteins (gps) nourish and protect newborn and adult tissues. their saccharides, which resemble cell membrane components, may block pathogen adhesion and infection. in the present study, they were examined by a battery of lectins from plants, animals, and bacteria, using hemagglutination inhibition and western blot analyses. the lectins included galactophilic ones from aplysia gonad, erythrina corallodendron, maclura pomifera (mpl), peanut, and p ... | 2005 | 16259015 |
| electrocatalytic hydrogen oxidation by an enzyme at high carbon monoxide or oxygen levels. | use of hydrogen in fuel cells requires catalysts that are tolerant to oxygen and are able to function in the presence of poisons such as carbon monoxide. hydrogen-cycling catalysts are widespread in the bacterial world in the form of hydrogenases, enzymes with unusual active sites composed of iron, or nickel and iron, that are buried within the protein. we have established that the membrane-bound hydrogenase from the beta-proteobacterium ralstonia eutropha h16, when adsorbed at a graphite electr ... | 2005 | 16260746 |
| nitrogen-fixing nodules from rose wood legume trees (dalbergia spp.) endemic to madagascar host seven different genera belonging to alpha- and beta-proteobacteria. | although legume biodiversity is concentrated in tropical regions, the majority of studies on legume nodulating bacteria (lnb) are focused on cultivated leguminous plants from temperate regions. however, recent works on tropical regions tend to indicate that the actual diversity of lnb is largely underestimated. in this study, we report the isolation and characterization of 68 nitrogen-fixing root nodule bacteria collected from eight endemic tree species of dalbergia in madagascar. the isolates w ... | 2005 | 16262864 |
| application of a kdpg-aldolase gene-dependent addiction system for enhanced production of cyanophycin in ralstonia eutropha strain h16. | two different recombinant plasmids both containing the cyanophycin synthetase gene (cpha) of synechocystis sp. strain pcc6308 but differing concerning the resistance marker gene were tested for their suitability to produce high amounts of cyanophycin in recombinant strains of ralstonia eutropha. various cultivation experiments at the 30-l scale revealed very low cyanophycin contents of the cells ranging from 4.6% to 6.2% (w/w) of cellular dry weight (cdw) only, most probably because most cells h ... | 2006 | 16266816 |
| update: ralstonia species associated with vapotherm oxygen delivery devices--united states, 2005. | this report updates information on ralstonia species associated with vapotherm oxygen delivery devices (vapotherm inc., stevensville, maryland). cdc has obtained new information from a test developed by cdc and performed by the children's hospital of philadelphia (pennsylvania) to assess the efficacy of the new chlorine dioxide disinfection protocol recommended by vapotherm. although limited, this information suggests that the new protocol for disinfecting vapotherm devices and cartridges might ... | 2005 | 16267498 |
| [from the mailing list sin: epidemic of infections caused by 'aquatic' bacteria in patients undergoing hemodialysis via central venous catheters]. | bacteremia due to central venous catheter (cvc) infection is the most frequent complication of cvc use as vascular access for hemodialysis (hd). we report a case of an epidemic of cvc infections caused by 3 strains of unusual bacteria: ralstonia pickettii (rp), leifsonia xyli/leifsonia aquatica (lxa), tsuckamurella strandjordae (ts). from 20/8/01 to 30/9/01, 23 of 35 patients dialyzed via cvcs experienced intra-hd pyrogenic reactions. their hemocultures were positive for: rp (14 pts), lxa (3 pts ... | 2005 | 16267809 |
| polyphenol oxidase activity expression in ralstonia solanacearum. | sequencing of the genome of ralstonia solanacearum revealed several genes that putatively code for polyphenol oxidases (ppos). to study the actual expression of these genes, we looked for and detected all kinds of ppo activities, including laccase, cresolase, and catechol oxidase activities, in cellular extracts of this microorganism. the conditions for the ppo assays were optimized for the phenolic substrate, ph, and sodium dodecyl sulfate concentration used. it was demonstrated that three diff ... | 2005 | 16269713 |
| [cloning and expression of a 2-naphthoate monooxygenase gene (nmo) in burkholderia sp. jt1500]. | a 4.8kb dna fragment from one blue colony of the plarf1 gene library of burkholderia sp. jt1500 was subcloned to puc18, designated as pek123. the sequence of the inserted 4.8kb dna' of pek123 was analyzed and submitted to embl nucleotide database, the accession # is aj566333. the transformants of pek123 could also become blue in lb agar and sequence analysis showed that three open reading frames and a putative promoter sequence were located in this inserted fragment. then the 4.4kb insert fragme ... | 2003 | 16281557 |
| dispersion optimization to enhance phb production in fed-batch cultures of ralstonia eutropha. | despite its many useful properties, microbial production of poly-beta-hydroxybutyrate (phb) is not yet commercially competitive with synthetic polymers. one reason is inadequate optimization of the fermentation under industrial conditions. in this study, a physiologically reasonable and experimentally validated kinetic model for phb synthesis by ralstonia eutropha was incorporated into a dispersion model to simulate a large fed-batch bioreactor. solutions of the model indicated that cell growth ... | 2006 | 16289872 |
| effect of expressing polyhydroxybutyrate synthesis genes (phbcab) in streptococcus zooepidemicus on production of lactic acid and hyaluronic acid. | hyaluronic acid (ha) has been industrially produced using the gram-positive bacterium streptococcus zooepidemicus. large amount of lactic acid formation was one of the important factors that restricted cell growth and ha productivity and lowered the substrate to ha conversion efficiency in a fermentor. in this study, polyhydroxybutyrate (phb) synthesis genes (phbcab) of ralstonia eutropha were cloned from the plasmid pbhr68 and were inserted into the plasmid peu308, an expression vector for gram ... | 2006 | 16292535 |
| antimicrobial susceptibility patterns of unusual nonfermentative gram-negative bacilli isolated from latin america: report from the sentry antimicrobial surveillance program (1997-2002). | the antimicrobial susceptibility of 176 unusual non-fermentative gram-negative bacilli (nf-gnb) collected from latin america region through the sentry program between 1997 and 2002 was evaluated by broth microdilution according to the national committee for clinical laboratory standards (nccls) recommendations. nearly 74% of the nf-bgn belonged to the following genera/species: burkholderia spp. (83), achromobacter spp. (25), ralstonia pickettii (16), alcaligenes spp. (12), and cryseobacterium sp ... | 2005 | 16302068 |
| sequential removal of heavy metals ions and organic pollutants using an algal-bacterial consortium. | the residual algal-bacterial biomass from photosynthetically supported, organic pollutant biodegradation processes, in enclosed photobioreactors, was tested for its ability to accumulate cu(ii), ni(ii), cd(ii), and zn(ii). salicylate was chosen as a model contaminant. the algal-bacterial biomass combined the high adsorption capacity of microalgae with the low cost of the residual biomass, which makes it an attractive biosorbent for environmental applications. cu(ii) was preferentially taken-up f ... | 2006 | 16307789 |
| microbial and kinetic characterization of pure and mixed cultures aerobically degrading 4-nitrophenol. | the molecular and kinetic characterization of a microorganism able to aerobically degrade 4-nitrophenol (4np) is presented. the microorganism was isolated from a mixed culture operating in a laboratory-scale sequencing batch reactor with an aerobic anoxic cycle. it was identified as a member of ralstonia genus within betaproteobacteria. it is a gram negative coccobacillum (cell length of 2-3 microm) able to aerobically store lipid inclusions when grown aerobically on nitrophenol as the sole carb ... | 2006 | 16309731 |
| ca2+-dependent lipid binding and membrane integration of popa, a harpin-like elicitor of the hypersensitive response in tobacco. | popa is released by type iii secretion from the bacterial plant pathogen ralstonia solanacearum and triggers the hypersensitive response (hr) in tobacco. the function of popa remains obscure, mainly because mutants lacking this protein are not altered in their ability to interact with plants. in an attempt to identify the site of popa activity in plant cells, we generated transgenic tobacco plants expressing the popa gene under the control of an inducible promoter. immunocytologic analysis revea ... | 2005 | 16313625 |
| interaction between poly[(r)-3-hydroxybutyrate] depolymerase and biodegradable polyesters evaluated by atomic force microscopy. | adsorption of phb depolymerase from ralstonia pickettii t1 to biodegradable polyesters such as poly[(r)-3-hydroxybutyrate] (phb) and poly(l-lactic acid) (plla) was investigated by atomic force microscopy (afm). the substrate-binding domain (sbd) with histidines within the n-terminus was prepared and immobilized on the afm tip surface via a self-assembled monolayer with a nitrilotriacetic acid group. using the functionalized afm tips, the force-distance measurements for polyesters were carried ou ... | 2005 | 16316121 |
| symbiotic association in chlorella culture. | chlorella sorokiniana iam c-212 has long been maintained in slant culture as a mixed strain, representing an associated natural microbial consortium. in this study, the consortium was separated and five nonalgal constituents, a fungal strain (cssf-1), and four bacterial strains (cssb-1, cssb-2, cssb-3, and cssb-4) were isolated and identified. 16s rdna sequence analysis revealed that strains cssb-1, cssb-2, cssb-3, and cssb-4 were close to ralstonia pickettii (99.8% identity), sphingomonas sp. d ... | 2005 | 16329867 |
| ralstonia pickettii: a persistent gram-negative nosocomial infectious organism. | non-fermenting gram-negative bacilli create a significant problem in clinical settings, being a widespread cause of nosocomial infections. they are opportunistic pathogens that take advantage of underlying conditions and diseases. ralstonia pickettii, a non-fermenting gram-negative bacillus, is regarded as being of minor clinical significance; however, many instances of infections with this organism are reported in the literature. infections can include bacteraemia/septicaemia caused by contamin ... | 2006 | 16337309 |
| electrochemical definitions of o2 sensitivity and oxidative inactivation in hydrogenases. | a new strategy is described for comparing, quantitatively, the ability of hydrogenases to tolerate exposure to o2 and anoxic oxidizing conditions. using protein film voltammetry, the inherent sensitivities to these challenges (thermodynamic potentials and rates of reactions) have been measured for enzymes from a range of mesophilic microorganisms. in the absence of o2, all the hydrogenases undergo reversible inactivation at various potentials above that of the h+/h2 redox couple, and h2 oxidatio ... | 2005 | 16366571 |
| outbreak of ralstonia pickettii bacteremia in a neonatal intensive care unit. | ralstonia pickettii is a gram-negative bacillus commonly found in soil and moist environments; however, r. pickettii is rarely isolated from clinical specimens. in august 2001, a cluster of r. pickettii bacteremia occurred among neonatal intensive care unit (nicu) infants at a california hospital. | 2005 | 16371873 |
| the effects of cyanobacterial exudates on bacterial growth and biodegradation of organic contaminants. | the pulp and paper industry largely depends on the biodegradation activities of heterotrophic bacteria to remove organic contaminants in wastewater prior to discharge. our recent discovery of extensive cyanobacterial communities in pulp and paper waste treatment systems led us to investigate the potential impacts of cyanobacterial exudates on growth and biodegradation efficiency of three bacterial heterotrophs. each of the three assessed bacteria represented different taxa commonly found in pulp ... | 2006 | 16382284 |
| growth in stewart's medium is a simple, rapid and inexpensive screening tool for the identification of burkholderia cepacia complex. | ninety-one percent of burkholderia cepacia complex reference strains (66 out of 72) displayed a yellow slope-green butt colour reaction after growth in stewart's medium indicating the oxidation of glucose and the absence of an arginine dihydrolase system. this same colour reaction was observed for burkholderia gladioli and several ralstonia species, but not for pseudomonas aeruginosa, stenotrophomonas, achromobacter, pandoraea and several other gram-negative non-fermenting bacilli. we therefore ... | 2006 | 16386966 |
| engineering the monomer composition of polyhydroxyalkanoates synthesized in saccharomyces cerevisiae. | polyhydroxyalkanoates (phas) have received considerable interest as renewable-resource-based, biodegradable, and biocompatible plastics with a wide range of potential applications. we have engineered the synthesis of pha polymers composed of monomers ranging from 4 to 14 carbon atoms in either the cytosol or the peroxisome of saccharomyces cerevisiae by harnessing intermediates of fatty acid metabolism. cytosolic pha production was supported by establishing in the cytosol critical beta-oxidation ... | 2006 | 16391089 |
| involvement of quinolinate phosphoribosyl transferase in promotion of potato growth by a burkholderia strain. | burkholderia sp. strain psjn stimulates root growth of potato explants compared to uninoculated controls under gnotobiotic conditions. in order to determine the mechanism by which this growth stimulation occurs, we used tn5 mutagenesis to produce a mutant, h41, which exhibited no growth-promoting activity but was able to colonize potato plants as well as the wild-type strain. the gene associated with the loss of growth promotion in h41 was shown to exhibit 65% identity at the amino acid level to ... | 2006 | 16391116 |
| effect of ph on the toxicity of nickel and other divalent metals to burkholderia cepacia pr1(301). | nickel (ni) is a common cocontaminant at many waste sites where the soils and sediments often are acidic, thereby influencing metal availability. growth of burkholderia cepacia pr1(301) was not affected at 3.41 mm ni at ph 5, but was inhibited by 73.2% at ph 6 and inhibited completely at ph 7 compared to growth without ni. this ph effect was not observed in the ni-resistant strains, ralstonia metallidurans ch34 and 31a. predicted ni speciation did not explain the observed toxicity trends. sorpti ... | 2005 | 16398108 |
| [physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, ralstonia eutropha b8562]. | the physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain ralstonia eutropha b8562 were investigated in comparison with the parent strain r. eutropha b5786. the morphological, cultural, and biochemical characteristics of strain r. eutropha b8562 were similar to those of strain r. eutropha b5786. genetic analysis revealed differences between the 16s rrna gene sequences of these strains. the growth characteristics of the mutant using glucose as th ... | 2005 | 16400989 |
| a tyrosinase with an abnormally high tyrosine hydroxylase/dopa oxidase ratio. | the sequencing of the genome of ralstonia solanacearum[salanoubat m, genin s, artiguenave f, et al. (2002) nature 415, 497-502] revealed several genes that putatively code for polyphenol oxidases (ppos). this soil-borne pathogenic bacterium withers a wide range of plants. we detected the expression of two ppo genes (accession numbers np_518458 and np_519622) with high similarity to tyrosinases, both containing the six conserved histidines required to bind the pair of type-3 copper ions at the ac ... | 2006 | 16403014 |
| identification of open reading frames unique to a select agent: ralstonia solanacearum race 3 biovar 2. | an 8x draft genome was obtained and annotated for ralstonia solanacearum race 3 biovar 2 (r3b2) strain uw551, a united states department of agriculture select agent isolated from geranium. the draft uw551 genome consisted of 80,169 reads resulting in 582 contigs containing 5,925,491 base pairs, with an average 64.5% gc content. annotation revealed a predicted 4,454 protein coding open reading frames (orfs), 43 trnas, and 5 rrnas; 2,793 (or 62%) of the orfs had a functional assignment. the uw551 ... | 2006 | 16404955 |
| bioluminescent monitoring of turbulent bioconvection. | under adjusted experimental conditions, open-to-air cultures of lux gene-engineered ralstonia eutropha (wholecell biosensors of copper) exhibit bioconvection, which accounts for fluctuating bioluminescence. the power spectrum of bioluminescence intensity fluctuations recorded from a cylindrical sample 9 mm in diameter and approximately 10 mm in height is characterized by a dominant low-frequency oscillation (with a characteristic period of approximately 8-12 min), which is occasionally accompani ... | 2006 | 16416487 |
| no-dependent transcriptional activation of gene expression in ralstonia eutropha h16. | the sigma54-dependent transcriptional regulator norr of ralstonia eutropha h16 activates gene expression in response to nitric oxide (no). the n-terminal domain of norr is thought to be involved in signal perception. a c112s exchange within this domain abolished promoter activation by the mutated protein, indicating that cys(112) is essential for the signalling mechanism of norr. the dna region recognized by norr contains three copies of a conserved element termed the norr-box. alteration of bas ... | 2006 | 16417516 |
| an improved purification procedure for the soluble [nife]-hydrogenase of ralstonia eutropha: new insights into its (in)stability and spectroscopic properties. | infrared (ir) spectra in combination with chemical analyses have recently shown that the active ni-fe site of the soluble nad(+)-reducing [nife]-hydrogenase from ralstonia eutropha contains four cyanide groups and one carbon monoxide as ligands. experiments presented here confirm this result, but show that a variable percentage of enzyme molecules loses one or two of the cyanide ligands from the active site during routine purification. for this reason the redox conditions during the purification ... | 2006 | 16418856 |
| site-directed mutagenesis of gentisate 1,2-dioxygenases from klebsiella pneumoniae m5a1 and ralstonia sp. strain u2. | gentisate 1,2-dioxygenase (gdo, ec 1.13.11.4) is the first enzyme in gentisate pathway that catalyses the ring fission of gentisate to form maleylpyruvate. phylogenetic tree of amino acid sequences from 11 gdos demonstrates that the gdos from different genus share identities between 12.1% and 64.8%. according to the alignment result, four highly conserved histidine residues in gdo from klebsiella pneumoniae m5a1 and ralstonia sp. strain u2 were chosen to be substituted with aspartate residues. e ... | 2006 | 16427517 |
| optimization of cyanophycin production in recombinant strains of pseudomonas putida and ralstonia eutropha employing elementary mode analysis and statistical experimental design. | elementary mode analysis was applied to simulate conditions for cyanophycin (cgp) biosynthesis and to optimize its production in bacteria. the conclusions from these simulations were confirmed by experiments with recombinant strains of the wild types and polyhydroxyalkanoate (pha)-negative mutants of ralstonia eutropha and pseudomonas putida expressing cgp synthetase genes (cpha) of synechocystis sp. strain pcc6308 or anabaena sp. strain pcc7120. in particular, the effects of suitable precursor ... | 2006 | 16435401 |
| production and properties of the native chromobacterium violaceum fucose-binding lectin (cv-iil) compared to homologous lectins of pseudomonas aeruginosa (pa-iil) and ralstonia solanacearum (rs-iil). | chromobacterium violaceum is a versatile, violet pigment (violacein)-producing beta-proteobacterium, confined to tropical and subtropical regions, dwelling in soil and water, like pseudomonas aeruginosa and ralstonia solanacearum. these three bacteria are saprophytes that occasionally become aggressive opportunistic pathogens virulently attacking animals (the first two) and plants (the third). the recent availability of their genome sequences enabled identification in the c. violaceum genome of ... | 2006 | 16436433 |
| ralstonia pickettii-innocent bystander or a potential threat? | | 2006 | 16441445 |
| nitrous oxide reductase genes (nosz) of denitrifying microbial populations in soil and the earthworm gut are phylogenetically similar. | earthworms emit nitrous oxide (n2o) and dinitrogen (n2). it has been hypothesized that the in situ conditions of the earthworm gut activates ingested soil denitrifiers during gut passage and leads to these in vivo emissions (m. a. horn, a. schramm, and h. l. drake, appl. environ. microbiol. 69:1662-1669, 2003). this hypothesis implies that the denitrifiers in the earthworm gut are not endemic to the gut but rather are regular members of the soil denitrifier population. to test this hypothesis, t ... | 2006 | 16461644 |
| the naphthalene catabolic (nag) genes of polaromonas naphthalenivorans cj2: evolutionary implications for two gene clusters and novel regulatory control. | polaromonas naphthalenivorans cj2, found to be responsible for the degradation of naphthalene in situ at a coal tar waste-contaminated site (c.-o. jeon et al., proc. natl. acad. sci. usa 100:13591-13596, 2003), is able to grow on mineral salts agar media with naphthalene as the sole carbon source. beginning from a 484-bp nagac-like region, we used a genome walking strategy to sequence genes encoding the entire naphthalene degradation pathway andadditional flanking regions. we found that the naph ... | 2006 | 16461653 |
| pyramiding unmarked deletions in ralstonia solanacearum shows that secreted proteins in addition to plant cell-wall-degrading enzymes contribute to virulence. | ralstonia solanacearum, like many phytopathogenic bacteria, makes multiple extracellular plant cell-wall-degrading enzymes (cwde), some of which contribute to its ability to cause wilt disease. cwde and many other proteins are secreted to the milieu via the highly conserved type ii protein secretion system (t2ss). r. solanacearum with a defective t2ss is weakly virulent, but it is not known whether this is due to absence of all the cwde or the loss of other secreted proteins that contribute to d ... | 2005 | 16478049 |
| utilization of capsaicin and vanillylamine as growth substrates by capsicum (hot pepper)-associated bacteria. | capsaicin contributes to the organoleptic attributes of hot peppers. here, we show that capsaicin is utilized as a growth nutrient by certain bacteria. enrichment cultures utilizing capsaicin were successfully initiated using capsicum-derived plant material or leaves of tomato (a related solanaceae) as inocula. no other sources of inoculum examined yielded positive enrichments. of 25 isolates obtained from enrichments: all utilized 8-methylnonanoic acid; nine were found capable of degrading caps ... | 2006 | 16478462 |
| tetratricopeptide repeats are essential for pcrh chaperone function in pseudomonas aeruginosa type iii secretion. | the type iii secretion system (t3ss) is a specialized apparatus evolved by gram-negative bacteria to deliver effector proteins into host cells, thus facilitating the establishment of an infection. effector translocation across the target cell plasma membrane is believed to occur via pores formed by at least two secreted translocator proteins, the functions of which are dependent upon customized class ii t3ss chaperones. recently, three internal tetratricopeptide repeats (tprs) were identified in ... | 2006 | 16487320 |
| biotoxicity assessment on reusability of municipal solid waste incinerator (mswi) ash. | this study provides a first attempt of dose-response analysis and margin of safety using escherichia coli dh5alpha, bacillus subtilis as indicator microorganisms to put forward, in general terms and explanations, the toxicity rankings of various ashes of municipal solid waste incinerator (mswi) for feasibility in further applications. since the mswi ash often contains cations of si, ca, al and fe, it is frequently considered to be recycled for construction building-materials. growth inhibition o ... | 2006 | 16490305 |
| a lower specificity phac2 synthase from pseudomonas stutzeri catalyses the production of copolyesters consisting of short-chain-length and medium-chain-length 3-hydroxyalkanoates. | a polyhydroxyalkanoate (pha) synthase gene phac2 (ps) from pseudomonas stutzeri strain 1317 was introduced into a pha synthase gene phbc (re) negative mutant, ralstonia eutropha phb(-)4. it conferred on the host strain the ability to synthesize pha, the monomer compositions of which varied widely when grown on different carbon sources. during cultivation on gluconate, the presence of phac2 (ps) in r. eutropha phb(-)4 led to the accumulation of polyhydroxybutyrate (phb) homopolymer in an amount o ... | 2006 | 16496091 |
| assessing nickel bioavailability in smelter-contaminated soils. | metal contaminants in soil environments derived from industrial pollution have clearly established the need for research on bioavailability and potential health risks. much research has been conducted on metal sorption in soils. however, there is still a need to better understand the availability of metal contaminants to plants and microbes. such information will enhance both human health and decisions about remediation efforts. in this study, welland loam (typic epiaquoll) and quarry muck (terr ... | 2006 | 16499951 |
| differentiation of species combined into the burkholderia cepacia complex and related taxa on the basis of their fatty acid patterns. | using the established commercial system sherlock (midi, inc.), cellular fatty acid methyl ester analysis for differentiation among burkholderia cepacia complex species was proven. the identification key based on the diagnostic fatty acids is able to discern phenotypically related ralstonia pickettii and pandoraea spp. and further distinguish burkholderia pyrrocinia, burkholderia ambifaria, and burkholderia vietnamiensis. | 2006 | 16517920 |
| crystal structure of 3-hydroxyanthranilic acid 3,4-dioxygenase from saccharomyces cerevisiae: a special subgroup of the type iii extradiol dioxygenases. | 3-hydroxyanthranilic acid 3,4-dioxygenase (3hao) is a non-heme ferrous extradiol dioxygenase in the kynurenine pathway from tryptophan. it catalyzes the conversion of 3-hydroxyanthranilate (haa) to quinolinic acid (quin), an endogenous neurotoxin, via the activation of n-methyl-d-aspartate (nmda) receptors and the precursor of nad(+) biosynthesis. the crystal structure of 3hao from s. cerevisiae at 2.4 a resolution shows it to be a member of the functionally diverse cupin superfamily. the struct ... | 2006 | 16522801 |
| an endoglucanase is involved in infection of rice roots by the not-cellulose-metabolizing endophyte azoarcus sp. strain bh72. | the nitrogen-fixing endophyte azoarcus sp. strain bh72 infects roots of kallar grass and rice inter- and intra-cellularly and can spread systemically into shoots without causing symptoms of plant disease. although cellulose or its breakdown products do not support growth, this strain expresses an endoglucanase, which might be involved in infection. sequence analysis of egla places the secreted 34-kda protein into the glycosyl hydrolases family 5, with highest relatedness (40% identity) to endogl ... | 2006 | 16529380 |
| differential expression of virulence genes and motility in ralstonia (pseudomonas) solanacearum during exponential growth. | a complex network regulates virulence in ralstonia solanacearum (formerly pseudomonas solanacearum); central to this system is phca, a lysr-type transcriptional regulator. we report here that two phca-regulated virulence factors, endoglucanase (egl) and acidic exopolysaccharide i (eps i), and motility are expressed differentially during exponential growth in batch cultures. tests with strains carrying lacz fusions in a wild-type genetic background revealed that expression (on a per-cell basis) o ... | 1997 | 16535550 |
| catabolism of 3-nitrophenol by ralstonia eutropha jmp 134. | ralstonia eutropha jmp 134 utilizes 3-nitrophenol as the sole source of nitrogen, carbon, and energy. the entire catabolic pathway of 3-nitrophenol is chromosomally encoded. an initial nadph-dependent reduction of 3-nitrophenol was found in cell extracts of strain jmp 134. by use of a partially purified 3-nitrophenol nitroreductase from 3-nitrophenol-grown cells, 3-hydroxylaminophenol was identified as the initial reduction product. resting cells of r. eutropha jmp 134 metabolized 3-nitrophenol ... | 1997 | 16535572 |
| bacterial metabolism of chlorinated dehydroabietic acids occurring in pulp and paper mill effluents. | chlorinated dehydroabietic acids are formed during the chlorine bleaching of wood pulp and are very toxic to fish. thus, destruction of these compounds is an important function of biological treatment systems for pulp and paper mill effluents. in this study, 12 strains of diverse, aerobic resin acid-degrading bacteria were screened for the ability to grow on chlorinated dehydroabietic acids as sole organic substrates. all seven strains of the class proteobacteria able to use dehydroabietic acid ... | 1997 | 16535663 |
| coliform bacteria in sierra nevada wilderness lakes and streams: what is the impact of backpackers, pack animals, and cattle? | the presence of coliform bacteria indicates a watershed risk for harboring microbes capable of causing human disease. we hypothesized that water from watersheds that have different human- or animal-use patterns would have differing risks for the presence of coliform bacteria. methods; water was collected in wilderness areas of the sierra nevada range in california. a total of 60 sites from lakes or streams were selected to statistically differentiate the risk categories: 1) high use by backpacke ... | 2006 | 16538940 |
| light-driven hydrogen production by a hybrid complex of a [nife]-hydrogenase and the cyanobacterial photosystem i. | in order to generate renewable and clean fuels, increasing efforts are focused on the exploitation of photosynthetic microorganisms for the production of molecular hydrogen from water and light. in this study we engineered a 'hard-wired' protein complex consisting of a hydrogenase and photosystem i (hydrogenase-psi complex) as a direct light-to-hydrogen conversion system. the key component was an artificial fusion protein composed of the membrane-bound [nife] hydrogenase from the beta-proteobact ... | 2006 | 16542111 |
| molecular dynamics simulations of a cyclic-beta-(1-->2) glucan containing an alpha-(1-->6) linkage as a 'molecular alleviator' for the macrocyclic conformational strain. | the conformational preferences of a cyclic osmoregulated periplasmic glucan of ralstonia solanacearum (opgr), which is composed of 13 glucose units and linked entirely via beta-(1-->2) linkages excluding one alpha-(1-->6) linkage, were characterized by molecular dynamics simulations. of the three force fields modified for carbohydrates that were applied to select a suitable one for the cyclic glucan, the carbohydrate solution force field (csff) was found to most accurately simulate the cyclic mo ... | 2006 | 16546149 |
| thiolysis of poly(3-hydroxybutyrate) with polyhydroxyalkanoate synthase from ralstonia eutropha. | poly(3-hydroxybutyrate) (phb) is synthesized from 3-hydroxybutyryl-coa by polyhydroxyalkanoate synthase and hydrolyzed by phb depolymerase. in this study, we focused on the reverse reaction of polyhydroxyalkanoate synthase, and propose the possibility that phb can be degraded through a novel process, that is thiolysis of phb with coash. polyhydroxyalkanoate synthase of ralstonia eutropha was incubated with 14c-labeled phb and coash. the reaction mixture was fractionated by hplc and then analyzed ... | 2006 | 16567428 |
| identification of genomic islands in six plant pathogens. | genomic islands (gis) play important roles in microbial evolution, which are acquired by horizontal gene transfer. in this paper, the gis of six completely sequenced plant pathogens are identified using a windowless method based on z curve representation of dna sequences. consequently, four, eight, four, one, two and four gis are recognized with the length greater than 20-kb in plant pathogens agrobacterium tumefaciens str. c58, rolstonia solanacearum gmi1000, xanthomonas axonopodis pv. citri st ... | 2006 | 16581205 |
| sequencing and heterologous expression of an epimerase and two lyases from iminodisuccinate-degrading bacteria. | recently, degradation of all existing epimers of the complexing agent iminodisuccinate (ids) in the bacterial strain agrobacterium tumefaciens by6 was proven to depend on an epimerase and a c-n lyase (cokesa et al., appl. environ. microbiol. 70:3941-3947, 2004). in the bacterial strain ralstonia sp. strain slrs7, a corresponding c-n lyase is responsible for the initial degradation step (cokesa et al., biodegradation 15:229-239, 2004). the ite gene, encoding the ids-transforming epimerase, and th ... | 2006 | 16597988 |
| bacteriological urinalysis in patients after renal transplantation. | the study consisted of microbiological urinalysis performed in 269 patients after renal transplantation who remained under medical care at the outpatient service of the transplantation institute in warsaw. the patients enrolled into the study had undergone renal transplantation 6 to 72 months before urine samples were collected. 304 urinalysis were performed. in the group of 269 patients, 42 individuals had bacteria in their urine what was confirmed in 47 urine cultures. cases of bacteriuria wer ... | 2005 | 16599304 |
| identification of qtls for ralstonia solanacearum race 3-phylotype ii resistance in tomato. | resistance against a ralstonia solanacearum race 3-phylotype ii strain jt516 was assessed in a f(2:3) and a population of inbred lines (ril), both derived from a cross between l. esculentum cv. hawaii 7996 (partially resistant) and l. pimpinellifolium wva700 (susceptible). resistance criteria used were the percentage of wilted plants to calculate the audpc value, and bacterial colonization scores in roots and stem (hypocotyl and epicotyl) assessed in two independent greenhouse experiments conduc ... | 2006 | 16614830 |
| molecular analysis of microbial communities identified in different developmental stages of ixodes scapularis ticks from westchester and dutchess counties, new york. | ixodes scapularis ticks play an important role in the transmission of a wide variety of pathogens between various mammalian species, including humans. pathogens transmitted by ticks include borrelia, anaplasma and babesia. although ticks may harbour both pathogenic and non-pathogenic microflora, little is known about how the diversity of the microflora within ticks may influence the transmission of pathogens. to begin addressing this question, we examined the composition of bacterial communities ... | 2006 | 16623735 |
| cupriavidus pinatubonensis sp. nov. and cupriavidus laharis sp. nov., novel hydrogen-oxidizing, facultatively chemolithotrophic bacteria isolated from volcanic mudflow deposits from mt. pinatubo in the philippines. | taxonomic studies were performed on ten hydrogen-oxidizing, facultatively chemolithotrophic bacteria that were isolated from volcanic mudflow deposits derived from the eruption of mt. pinatubo in the philippines in 1991. phylogenetic analysis based on 16s rrna gene sequences indicated that these isolates belonged to the genus cupriavidus of the betaproteobacteria; sequence similarity values with their nearest phylogenetic neighbour, cupriavidus basilensis, were 97.1-98.3 %. in addition to phylog ... | 2006 | 16627640 |
| survival of gfp-tagged antagonistic bacteria in the rhizosphere of tomato plants and their effects on the indigenous bacterial community. | the survival and colonization patterns of pseudomonas putida prd16 and enterobacter cowanii prf116 in the rhizosphere of greenhouse-grown tomato plants and the effects of their inoculation on the indigenous bacterial community were followed by selective plating, molecular fingerprinting, and confocal laser scanning microscopy (clsm) over 3 weeks. both strains, which showed in vitro antagonistic activity against ralstonia solanacearum, were previously tagged with gfp. seed and root inoculation we ... | 2006 | 16629751 |
| biodegradation of vinyl chloride and cis-dichloroethene by a ralstonia sp. strain trw-1. | an aerobic bacterium, ralstonia sp. strain trw-1, that assimilates vinyl chloride (vc) or ethene (eth) as the sole carbon source was isolated from a chloroethene-degrading enrichment culture. phylogenetic analysis of 16s rdna sequence of the isolate revealed almost 99% sequence similarity to ralstonia pickettii. to our knowledge, this is the first report describing the isolation of a member of ralstonia that can degrade vc as the growth substrate. the measured growth yield values for vc and eth ... | 2006 | 16642331 |
| [nife]-hydrogenases of ralstonia eutropha h16: modular enzymes for oxygen-tolerant biological hydrogen oxidation. | recent research on hydrogenases has been notably motivated by a desire to utilize these remarkable hydrogen oxidation catalysts in biotechnological applications. progress in the development of such applications is substantially hindered by the oxygen sensitivity of the majority of hydrogenases. this problem tends to inspire the study of organisms such as ralstonia eutropha h16 that produce oxygen-tolerant [nife]-hydrogenases. r. eutropha h16 serves as an excellent model system in that it produce ... | 2005 | 16645314 |
| population dynamics within a microbial consortium during growth on diesel fuel in saline environments. | the diversity and dynamics of a bacterial community extracted from an exploited oil field with high natural soil salinity near comodoro rivadavia in patagonia (argentina) were investigated. community shifts during long-term incubation with diesel fuel at four salinities between 0 and 20% nacl were monitored by single-strand conformation polymorphism community fingerprinting of the pcr-amplified v4-v5 region of the 16s rrna genes. information obtained by this qualitative approach was extended by ... | 2006 | 16672500 |
| chemotaxis is required for virulence and competitive fitness of the bacterial wilt pathogen ralstonia solanacearum. | ralstonia solanacearum, a soilborne plant pathogen of considerable economic importance, invades host plant roots from the soil. qualitative and quantitative chemotaxis assays revealed that this bacterium is specifically attracted to diverse amino acids and organic acids, and especially to root exudates from the host plant tomato. exudates from rice, a nonhost plant, were less attractive. eight different strains from this heterogeneous species complex varied significantly in their attraction to a ... | 2006 | 16672623 |
| mutation on n-terminus of polyhydroxybutyrate synthase of ralstonia eutropha enhanced phb accumulation. | polyhydroxyalkanoate (pha) synthase is the central enzyme involved in the biosynthesis of pha, a family of bacterial biodegradable polyesters. due to its high variability, the n-terminal fragment of this enzyme was previously considered as unnecessary for a functionally active enzyme. in this study, polyhydroxybutyrate synthase from ralstonia eutropha (phbc(re)) with a deletion on n-terminal 88 amino acid residues showed a significant reduced activity, as reflected by only 1.5% phb accumulation ... | 2006 | 16673109 |
| utilizing ultrafiltration to remove alkaline phosphatase from clinical analyzer water. | alkaline phosphatase (alp) conjugated to antibodies is often used in enzyme immunoassays (eias). these assays are notably sensitive to experimental conditions. a possible source of interference is bacterial alp, which is released when bacterial contamination occurs in clinical analyzers. preliminary experiments led to the selection of a detection kit, alp source, and specific types of tubes for collecting water samples and performing assays. the release of alp from various strains of bacteria id ... | 2006 | 16681431 |
| modeling and optimization of biopolymer (polyhydroxyalkanoates) production from ice cream residue by novel statistical experimental design. | polyhydroxyalkanoates (phas) are thermoplastic polyesters synthesized by ralstonia eutropha and other bacteria as a form of intracellular carbon and energy storage and are accumulated as lipid inclusions in the cytoplasm of these bacteria. the modeling and optimization of pha production by fermentation from industrial waste (ice cream residue) was studied by employing statistical experimental design methods. a series of iterative experimental designs was used to find optimal factor conditions (m ... | 2006 | 16702606 |
| 2,4-dichlorophenoxyacetic acid (2,4-d) utilization by delftia acidovorans mc1 at alkaline ph and in the presence of dichlorprop is improved by introduction of the tfdk gene. | growth of delftia acidovorans mc1 on 2,4-dichlorophenoxyacetic acid (2,4-d) and on racemic 2-(2,4-dichlorophenoxy)propanoic acid ((rs)-2,4-dp) was studied in the perspective of an extension of the strain's degradation capacity at alkaline ph. at ph 6.8 the strain grew on 2,4-d at a maximum rate (mu max) of 0.158 h(-1). the half-maximum rate-associated substrate concentration (ks) was 45 microm. at ph 8.5 mu max was only 0.05 h(-1) and the substrate affinity was mucher lower than at ph 6.8. the i ... | 2006 | 16715405 |
| transcriptomic and proteomic analyses of the pmol30-encoded copper resistance in cupriavidus metallidurans strain ch34. | the four replicons of cupriavidus metallidurans ch34 (the genome sequence was provided by the us department of energy-university of california joint genome institute) contain two gene clusters putatively encoding periplasmic resistance to copper, with an arrangement of genes resembling that of the copsrabcd locus on the 2.1 mb megaplasmid (mpl) of ralstonia solanacearum, a closely related plant pathogen. one of the copsrabcd clusters was located on the 2.6 mb mpl, while the second was found on t ... | 2006 | 16735739 |
| preliminary electrochemical studies of the flavohaemoprotein from ralstonia eutropha entrapped in a film of methyl cellulose: activation of the reduction of dioxygen. | a flavohaemoprotein (fhp) from ralstonia eutropha, obtained in a pure and active form, has been entrapped in a film of methyl cellulose on the electrode surface and gives a stable and reproducible electrochemical response at ph 7.00 when subject to cyclic voltammetry using a glassy carbon electrode. to our knowledge, no previous direct electrochemistry had been achieved with a bacterial flavohaemoglobin, which possess both a fad and a haem. a single couple is observed which is assigned to the ha ... | 2007 | 16750432 |
| subterfuge and manipulation: type iii effector proteins of phytopathogenic bacteria. | diverse gram-negative bacteria deliver effector proteins into the cells of their eukaryotic hosts using the type iii secretion system. collectively, these type iii effector proteins function to optimize the host cell environment for bacterial growth. type iii effector proteins are essential for the virulence of pseudomonas syringae, xanthomonas spp., ralstonia solanacearum and erwinia species. type iii secretion systems are also found in nonpathogenic pseudomonads and in species of symbiotic nit ... | 2006 | 16753033 |
| outbreak of ralstonia pickettii pseudobacteremia among patients with hematological malignancies. | | 2006 | 16755490 |