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inactivation of pqq genes of enterobacter intermedium 60-2g reduces antifungal activity and induction of systemic resistance.enterobacter intermedium 60-2g, a phosphate solubilizing bacterium, has the ability to induce systemic resistance in plants against soft rot pathogen erwinia carotovora. glucose dehydrogenase, an enzyme that utilizes pyrroloquinoline quinone (pqq) as a cofactor, is required for the synthesis of gluconic acid by e. intermedium 60-2g. here, we report that the pqqa and pqqb genes are required for phosphate solubilization and induced systemic resistance against a soft rot pathogen in tobacco. mutati ...200818355275
synthesis and biological activity of analogues of vanchrobactin, a siderophore from vibrio anguillarum serotype o2.several analogues of vanchrobactin, a catechol siderophore isolated from the bacterial fish pathogen vibrio anguillarum serotype o2 strain rv22, have been synthesized. the biological evaluation of these novel compounds showed that most of them are active as siderophores, as determined by growth promotion assays using the producer strain, as well as v. anguillarum serotype o1, salmonella enterica, and erwinia chrysanthemi. these compounds also gave a positive chrome azurol-s (cas) test. on the ba ...200818362969
carbohydrate and ethane release with erwinia carotovora subspecies betavasculorum--induced necrosis.erwinia carotovora subspecies betavasculorum, also known as e. betavasculorum and pectobacterium betavasculorum, is a soil bacterium that has the capacity to cause root rot necrosis of sugarbeets. the qualitatively different pathogenicity exhibited by the virulent e. carotovora strain and two avirulent strains, a citrobacter sp. and an enterobacter cloacae, was examined using digital analysis of photographic evidence of necrosis as well as for carbohydrate, ethane, and ethylene release compared ...200818066619
two xanthomonas extracellular polygalacturonases, pghaxc and pghbxc, are regulated by type iii secretion regulators hrpx and hrpg and are required for virulence.xanthomonas campestris pv. campestris, the causal agent of black rot disease, produces a suite of extracellular cell-wall degrading enzymes (cwde) that are involved in bacterial virulence. polygalacturonase (pg) is an important cwde and functions to degrade the pectic layers of plant cell walls. although previous studies have documented the virulence functions of pg in erwinia and ralstonia species, the regulation of pg genes still needs to be elucidated. in this study, we identified two novel p ...200818393615
natural variation of potato allene oxide synthase 2 causes differential levels of jasmonates and pathogen resistance in arabidopsis.natural variation of plant pathogen resistance is often quantitative. this type of resistance can be genetically dissected in quantitative resistance loci (qrl). to unravel the molecular basis of qrl in potato (solanum tuberosum), we employed the model plant arabidopsis thaliana for functional analysis of natural variants of potato allene oxide synthase 2 (staos2). staos2 is a candidate gene for qrl on potato chromosome xi against the oömycete phytophthora infestans causing late blight, and the ...200818431595
expression of a harpin-encoding gene in rice confers durable nonspecific resistance to magnaporthe grisea.engineering durable nonspecific resistance to phytopathogens is one of the ultimate goals of plant breeding. however, most attempts to reach this goal fail as a result of rapid changes in pathogen populations and the sheer diversity of pathogen infection mechanisms. in this study, we show that the expression of a harpin-encoding gene (hrf1), derived from xanthomonas oryzae pv. oryzae, confers nonspecific resistance in rice to the blast fungus magnaporthe grisea. transgenic plants and their t1-t7 ...200818005094
enterobacteriaceae and related organisms isolated from shell eggs collected during commercial processing.in the united states, commercial shell eggs are washed and graded before retail. since passage of the egg products inspection act in 1971, processing guidelines have been set to ensure that external and internal characteristics are maintained. however, less is known about how commercial processing affects the safety of shell eggs. to identify enteric bacteria entering plants and persisting throughout processing, eggs were collected from 3 us commercial shell egg-processing plants on 3 separate v ...200818493013
is 16s rdna a reliable phylogenetic marker to characterize relationships below the family level in the enterobacteriaceae?the phylogenetic relationships of multiple enterobacterial species were reconstructed based on 16s rdna gene sequences to evaluate the robustness of this housekeeping gene in the taxonomic placement of the enteric plant pathogens erwinia, brenneria, pectobacterium, and pantoea. four data sets were compiled, two of which consisted of previously published data. the data sets were designed in order to evaluate how 16s rdna gene phylogenies are affected by the use of different plant pathogen accessi ...200818504519
functional diversity among metallo-beta-lactamases: characterization of the car-1 enzyme of erwinia carotovora.metallo-beta-lactamases (mbls) are zinc-dependent bacterial enzymes characterized by an efficient hydrolysis of carbapenems and a lack of sensitivity to commercially available beta-lactamase inactivators. apart from the acquired subclass b1 enzymes, which exhibit increasing clinical importance and whose evolutionary origin remains unclear, most mbls are encoded by resident genes found in the genomes of organisms belonging to at least three distinct phyla. using genome database mining, we identif ...200818443127
analysis of bacterial community during the fermentation of pulque, a traditional mexican alcoholic beverage, using a polyphasic approach.in this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional mexican alcoholic beverage from maguey (agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. the work included the isolation of lactic acid bacteria (lab), aerobic mesophiles, and 16s rdna clone libraries from total dna extracted from the maguey sap (aguamiel) used as substrate, after inoculati ...200818450312
cloning of a putative hypersensitive induced reaction gene from wheat infected by stripe rust fungus.the hypersensitive response (hr) is one of the most efficient forms of plant defense against biotrophic pathogens and results in localized cell death and the formation of necrotic lesions. in this study, a novel putative hypersensitive induced reaction (hir) gene from wheat leaves infected by incompatible stripe rust pathogen cy23, designated as ta-hir1, was identified by using rapid amplification of cdna ends (race). ta-hir1 encodes 284 amino acids, with a predicted molecular mass of 31.31 kda. ...200817980516
the acyl-homoserine lactone-type quorum-sensing system modulates cell motility and virulence of erwinia chrysanthemi pv. zeae.erwinia chrysanthemi pv. zeae is one of the erwinia chrysanthemi pathovars that infects on both dicotyledons and monocotyledons. however, little is known about the molecular basis and regulatory mechanisms of its virulence. by using a transposon mutagenesis approach, we cloned the genes coding for an e. chrysanthemi pv. zeae synthase of acyl-homoserine lactone (ahl) quorum-sensing signals (expi(ecz)) and a cognate response regulator (expr(ecz)). chromatography analysis showed that expi(ecz) enco ...200818083823
secondary structures and functional requirements for thim riboswitches from desulfovibrio vulgaris, erwinia carotovora and rhodobacter spheroides.abstract bacterial thim riboswitches contain aptamer domains that bind the metabolite thiamine pyrophosphate (tpp). binding of tpp to the aptamer domain induces structural rearrangements that are relayed to the expression domain, thereby interfering with gene expression. here, we report identification of three putative thim riboswitches from different bacteria and analysis of their secondary structures. chemical probing revealed that the riboswitches share similar secondary structures in their a ...200818163882
differential role of ferritins in iron metabolism and virulence of the plant-pathogenic bacterium erwinia chrysanthemi 3937.during infection, the phytopathogenic enterobacterium erwinia chrysanthemi has to cope with iron-limiting conditions and the production of reactive oxygen species by plant cells. previous studies have shown that a tight control of the bacterial intracellular iron content is necessary for full virulence. the e. chrysanthemi genome possesses two loci that could be devoted to iron storage: the bfr gene, encoding a heme-containing bacterioferritin, and the ftna gene, coding for a paradigmatic ferrit ...200818165304
onion thrips, thrips tabaci, have gut bacteria that are closely related to the symbionts of the western flower thrips, frankliniella occidentalis.it has been shown that many insects have enterobacteriaceae bacteria in their gut system. the western flower thrips, frankliniella occidentalis pergande [thysanoptera: thripidae], has a symbiotic relation with erwinia species gut bacteria. to determine if other thripidae species have similar bacterial symbionts, the onion thrips, thrips tabaci, was studied because, like f. occidentalis, it is phytophagous. contrary to f. occidentalis, t. tabaci is endemic in europe and biotypes have been describ ...200820298113
early responses of tobacco suspension cells to rhizobacterial elicitors of induced systemic resistance.colonization of roots by selected strains of fluorescent pseudomonas spp. can trigger induced systemic resistance (isr) against foliar pathogens in a plant species-specific manner. it has been suggested that early responses in cell suspension cultures in response to rhizobacterial elicitors, such as generation of active oxygen species (aos) and extracellular medium alkalinization (ma), are linked to the development of isr in whole plants. perception of flagellin was demonstrated to elicit isr in ...200818986257
kunitz trypsin inhibitor: an antagonist of cell death triggered by phytopathogens and fumonisin b1 in arabidopsis.programmed cell death (pcd) is a central regulatory process in both plant development and in plant responses to pathogens. pcd requires a coordinate activation of pro-apoptotic factors such as proteases and suppressors inhibiting and modulating these processes. in plants, various caspase-like cysteine proteases as well as serine proteases have been implicated in pcd. here, we show that a serine protease (kunitz trypsin) inhibitor (kti1) of arabidopsis acts as a functional kti when produced in ba ...200819825555
wtse, an avre-family type iii effector protein of pantoea stewartii subsp. stewartii, causes cell death in non-host plants.pantoea stewartii subsp. stewartii (pnss) causes stewart's bacterial wilt of sweet corn and leaf blight of maize. the pathogenicity of pnss depends on synthesis of extracellular polysaccharide and an hrp type iii secretion system. wtse, a type iii secreted effector protein, is essential for the virulence of pnss on corn. it belongs to the avre family of effectors, which includes dspa/e from erwinia amylovora and avre1 from pseudomonas syringae. previously, wtse was shown to cause disease-associa ...200819018993
erwinia amylovora strains isolated in romania from outbreaks of fire blight disease: phenotypic characterization.the fire blight disease was described for the first time in romania, in 1992. since then by continuous spreading, this disease has caused severe damages of the fruit trees production, particularly of the pear and quince orchards in different regions of the country, being advantaged by certain weather conditions (high temperatures and humidity). an epidemiological surveillance of this disease that was spreading over different regions of the country, has been instituted since 2002. during the year ...200819496475
harpins and ion channels modulations: many ways to die.harpins are type three secretion system (ttss) effectors. while few harpins are thought to be translocators of ttss effectors through the host plasma membrane during plant/bacteria interactions, functions of many harpins remain for the moment mysterious. we recently showed that the hrpw(ea) harpin from erwinia amylovora, at subnamolar concentration, was able to decrease defense responses triggered by another harpin from this bacteria, hrpn(ea). this antagonism could be the result of opposed anio ...200819841656
hypersensitive response and acyl-homoserine lactone production of the fire blight antagonists erwinia tasmaniensis and erwinia billingiae.fire blight caused by the gram-negative bacterium erwinia amylovora can be controlled by antagonistic microorganisms. we characterized epiphytic bacteria isolated from healthy apple and pear trees in australia, named erwinia tasmaniensis, and the epiphytic bacterium erwinia billingiae from england for physiological properties, interaction with plants and interference with growth of e. amylovora. they reduced symptom formation by the fire blight pathogen on immature pears and the colonization of ...200821261861
analyses of the secretomes of erwinia amylovora and selected hrp mutants reveal novel type iii secreted proteins and an effect of hrpj on extracellular harpin levels.summary erwinia amylovora is a plant pathogenic enterobacterium that causes fire blight disease of apple, pear and other rosaceous plants. a type iii (t3) secretion system, encoded by clustered, chromosomal hrp genes (hypersensitive response and pathogenicity), is essential for infection, but only a few proteins are known that are secreted through this pathway (the t3 'secretome'). we developed an efficient protocol for purification and concentration of extracellular proteins and used it to char ...200720507478
disease resistance to bacterial pathogens affected by the amount of ferredoxin-i protein in plants.summary ferredoxin-i (fd-i) is a fundamental protein that is involved in several metabolic pathways. the amount of fd-i found in plants is generally regulated by environmental stress, including biotic and abiotic events. in this study, the correlation between quantity of fd-i and plant disease resistance was investigated. fd-i levels were increased by inoculation with pseudomonas syringae pv. syringae but were reduced by erwinia carotovora ssp. carotovora. transgenic tobacco over-expressing fd-i ...200720507485
dspa/e, a type iii effector of erwinia amylovora, is required for early rapid growth in nicotiana benthamiana and causes nbsgt1-dependent cell death.summary dspa/e is a pathogenicity factor of erwinia amylovora that is translocated into the plant cell cytoplasm through an hrp type iii secretion system. transient expression of dspa/e in nicotiana benthamiana or yeast induced cell death, as it does in n. tabacum and apple as described previously. dspa/e-induced cell death in n. benthamiana was not inhibited by coexpression of avrptob of pseudomonas syringae pv. tomato, which inhibits programmed cell death (pcd) induced by several other elicito ...200720507497
development of molecular markers linked to the 'fiesta' linkage group 7 major qtl for fire blight resistance and their application for marker-assisted selection.a fire blight resistance qtl explaining 34.3%-46.6% of the phenotypic variation was recently identified on linkage group 7 of apple cultivar 'fiesta' (f7). however, markers flanking this qtl were aflp and rapd markers unsuitable for marker-assisted selection (mas). two rapd markers bracketing the qtl have been transformed into scar (sequence-characterized amplified region) markers, and an ssr marker specific for the region was developed. pedigree analysis of 'fiesta' with these markers enabled t ...200717632578
rela-dependent (p)ppgpp production controls exoenzyme synthesis in erwinia carotovora subsp. atroseptica.in this report, we investigate the link between nutrient limitation, rela-mediated (p)ppgpp production, and virulence in the phytopathogen erwinia carotovora subsp. atroseptica. a rela null mutant (jwc7) was constructed by allelic exchange, and we confirmed that, unlike the wild-type progenitor, this mutant did not produce elevated levels of (p)ppgpp upon nutrient downshift. however, (p)ppgpp production could be restored in strain jwc7 during nutrient limitation by supplying rela in trans. durin ...200717766416
allergic reactions to e. coli l-asparaginase do not affect outcome in childhood b-precursor acute lymphoblastic leukemia: a children's oncology group study.we describe the outcome of children with b-precursor acute lymphoblastic leukemia registered on pediatric oncology group 8602 who switched to erwinia asparaginase (asp) due to an allergy to the escherichia coli product. between february 1986 and january 1991, children in complete remission after induction that included intramuscular e. coli asp (6000 u/m2x6) were randomized for consolidation. one regimen included intensive weekly intramuscular e. coli asp (25,000 u/m2/wkx24). in case of an aller ...200717805038
evaluation of two surface sampling methods for detection of erwinia herbicola on a variety of materials by culture and quantitative pcr.this research was designed to evaluate surface sampling protocols for use with culture and quantitative pcr (qpcr) amplification assay for detection of the gram-negative bacterial biothreat simulant erwinia herbicola on a variety of surface materials. surfaces selected for evaluation were wood laminate, glass and computer monitor screens, metal file cabinets, plastic arena seats, nylon seat cushions, finished concrete flooring, and vinyl tile flooring. laboratory and test chamber studies were pe ...200717416685
overexpression of the apple mpnpr1 gene confers increased disease resistance in malus x domestica.the npr1 gene plays a pivotal role in systemic acquired resistance in plants. its overexpression in arabidopsis and rice results in increased disease resistance and elevated expression of pathogenesis-related (pr) genes. an npr1 homolog, mpnpr1-1, was cloned from apple (malus x domestica) and overexpressed in two important apple cultivars, galaxy and m26. apple leaf pieces were transformed with the mpnpr1 cdna under the control of the inducible pin2 or constitutive cauliflower mosaic virus (camv ...200717990964
[modification of recombinant asparaginase from erwinia carotovora with polyethylene glycol 5000].a method for polyethylene conjugation with recombinant asparaginase has been developed to improve therapeutically important properties of this enzyme. methoxy-nitrophenyl carbamate of polyethylene glycol with molecular weight 5000 was employed as the modification reagent. optimization of pegylation procedure allowed achieving high level of the enzyme modification. under 4.5 molar excess of modification reagent more than 10 molecules of methoxy-polyethylene bound per one asparaginase molecular. t ...200717436691
specific recognition of saturated and 4,5-unsaturated hexuronate sugars by a periplasmic binding protein involved in pectin catabolism.the process of pectin depolymerization by pectate lyases and glycoside hydrolases produced by pectinolytic organisms, particularly the phytopathogens from the genus erwinia, is reasonably well understood. indeed each extracellular and intracellular catabolic stage has been identified using either genetic, bioinformatic or biochemical approaches. nevertheless, the molecular details of many of these stages remain unknown. in particular, the mechanism and ligand binding profiles for the transport o ...200717451747
relationships of plant pathogenic enterobacteria based on partial atpd, cara, and reca as individual and concatenated nucleotide and peptide sequences.relationships of the genera in the enterobacteriaceae containing plant pathogenic species: brenneria, dickeya, enterobacter, erwinia, pantoea, pectobacterium, and samsonia, were investigated by comparison of their nucleotide and peptide sequences of atpd, cara, reca, and the concatenated sequences. erwinia spp. and pantoea spp., with pectobacterium cypripedii, formed a group distinct from other pathogenic taxa. pectobacterium, brenneria, dickeya, and samsonia formed a contiguous clade. samsonia ...200717451899
[study of hrpn(csds001) and the gene expression profile of arabidopsis thaliana induced by harpin(csds001)].erwinia carotovora subsp. carotovora csds001 elicits hypersensitive reaction (hr) in tobacco. from the genomic libraries of erwinia carotovora subsp. carotovora csds001, the hrpncsds001 gene (genbank number ay939927), was isolated. the hrpncsds001 fusion protein was produced in escherichia coli, and was used to induce hr by injecting into tobacco. we further examined the global regulation of arabidopsis thaliana genes in response to harpincsds001 at a concentration of 30 miccrog/ml. we indicated ...200717548335
the heterologous expression of polysaccharidase-encoding genes with oenological relevance in saccharomyces cerevisiae.the main objective of this study was to develop polysaccharide-degrading wine strains of saccharomyces cerevisiae, which are able to improve aspects of wine processing and clarification, as well as colour extraction and stabilization during winemaking.200718045408
resistance to erwinia carotovora of plants associated with modified bacteria, which have lost their pathogenicity. 200718047035
[isolation and identification of rhodosporidium toruloides r1 degrading n-acyl homoserine lactone].in the present study, a ahl-utilizing strain ri was isolated and identified as the genus rhodosporidium toruloides r1 by physi-biochemical approaches and 18s rdna sequence analysis, and this strain was designated as r. toruloides r1. results showed that r. toruloides r1 exhibited the ability to utilize and degrade the all n-acyl homoserine lactones tested in this study. coculture of r. toruloides r1 with erwinia carotovora subsp. carotovora effectively inhibit the soft rot disease of patato caus ...200717552249
directed evolution for increased chitinase activity.directed evolution through dna shuffling and screening was used to enhance the catalytic ability of a fungal, beauveria bassiana, chitinase, bbchit1. the bbchit gene was first linked to various prokaryotic signal sequences and expressed in escherichia coli. the signal peptide, pelb, from erwinia carotovora resulted in greatest chitinase secretion into broth. the nucleotide sequence expressing pelb signal peptide was then incorporated into an e. coli vector to express bbchit1 variants generated b ...200717468866
cloning and expression of streptomycin inactivating enzymes aph(6)-ia and aph(6)-id.discovered in the 1940s by selman waksman, the aminoglycoside antibiotic streptomycin is clinically important in the treatment of tuberculosis worldwide. however, strains of mycobacterium tuberculosis and other pathogenic bacteria have become resistant to streptomycin. one mechanism by which this can occur is through the action of phosphotransferases that attach a phosphate group to position 6 of the streptidine ring of streptomycin, thereby inactivating it. two such phosphotransferases are aph( ...200717531152
efflux pump gene expression in erwinia chrysanthemi is induced by exposure to phenolic acids.salicylic acid (sa) is an important signaling molecule in local and systemic plant resistance. following infection by microbial pathogens and the initial oxidative burst in plants, sa accumulation functions in the amplification of defense gene expression. production of pathogenesis-related proteins and toxic antimicrobial chemicals serves to protect the plant from infection. successful microbial pathogens utilize a variety of mechanisms to rid themselves of toxic antimicrobial compounds. importa ...200717378434
cloning and expression of the erwinia carotovora subsp. carotovora gene encoding the low-molecular-weight bacteriocin carocin s1.the purpose of this study was to clone the carocin s1 gene and express it in a non-carocin-producing strain of erwinia carotovora. a mutant, th22-10, which produced a high-molecular-weight bacteriocin but not a low-molecular-weight bacteriocin, was obtained by tn5 insertional mutagenesis using h-rif-8-2 (a spontaneous rifampin-resistant mutant of erwinia carotovora subsp. carotovora 89-h-4). using thermal asymmetric interlaced pcr, the dna sequence from the tn5 insertion site and the dna sequenc ...200717071754
athipm, an ortholog of the apple hrpn-interacting protein, is a negative regulator of plant growth and mediates the growth-enhancing effect of hrpn in arabidopsis.hrpn (harpin) protein is critical to the virulence of the fire blight pathogen erwinia amylovora in host plants like apple (malus x domestica). moreover, exogenous treatment of arabidopsis (arabidopsis thaliana), a nonhost plant, with partially purified hrpn enhances growth. to address the bases of the effects of hrpn in disease, we sought a hrpn-interacting protein(s) in apple, using a yeast two-hybrid assay. a single positive clone, designated hipm (hrpn-interacting protein from malus), was fo ...200717704235
one step engineering of t7-expression strains for protein production: increasing the host-range of the t7-expression system.the t7-expression system has been very useful for protein expression in escherichia coli. however, it is often desirable to over-express proteins in species other than e. coli. here, we constructed an inducible broad-host-range t7-expression transposon, which allows simple one-step construction of t7-expression strains in various species, providing the option to over-express proteins of interest in a broader host-range. this transposon contains the t7 rna polymerase driven by the lacuv5 promoter ...200717716915
identification of a key functional region in harpins from xanthomonas that suppresses protein aggregation and mediates harpin expression in e. coli.in the current study, we identified a key functional region in harpins from xanthomonas that suppressed protein aggregation and mediated its expression in e. coli. our data suggested that the presence of two common features in harpins [wei et al. (1992) science 257:85-88], namely, high glycine content and lack of cysteine residues, were not sufficient for xanthomonas to elicit hypersensitive response (hr) activity or heat stability. additionally, bioinformatic analyses revealed that the secondar ...200717180733
global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of erwinia chrysanthemi 3937.production of the plant hormone indole-3-acetic acid (iaa) is widespread among plant-associated microorganisms. the non-gall-forming phytopathogen erwinia chrysanthemi 3937 (strain ech3937) possesses iaam (asap16562) and iaah (asap16563) gene homologues. in this work, the null knockout iaam mutant strain ech138 was constructed. the iaa production by ech138 was reduced in m9 minimal medium supplemented with l-tryptophan. compared with wild-type ech3937, ech138 exhibited reduced ability to produce ...200717189441
at-line coupling of uplc to chip-electrospray-fticr-ms.since highly sensitive on-line coupling of uplc with fticr-ms is technically infeasible due to their different scan rates, at-line coupling of these techniques was developed for rapid analysis. to enable cutting of one peak of the chromatogram into one fraction, several conditions and relationships were investigated, e.g. the optimum volume of the inserted delay loop, the relationship between retention time, loop outlet drop speed, individual drop volume versus mobile phase composition under con ...200717849105
identification of harpins in pseudomonas syringae pv. tomato dc3000, which are functionally similar to hrpk1 in promoting translocation of type iii secretion system effectors.harpins are a subset of type iii secretion system (t3ss) substrates found in all phytopathogenic bacteria that utilize a t3ss. pseudomonas syringae pv. tomato dc3000 was previously reported to produce two harpins, hrpz1 and hrpw1. dc3000 was shown here to deploy two additional proteins, hopak1 and hopp1, which have the harpin-like properties of lacking cysteine, eliciting the hypersensitive response (hr) when partially purified and infiltrated into tobacco leaves, and possessing a two-domain str ...200717873033
identification of bacteria from clinical samples using bartonella alpha-proteobacteria growth medium.in an effort to overcome historical problems associated with the isolation of bartonella species from animal and human blood samples, our laboratory developed a novel, chemically modified, insect-based, liquid culture medium (bartonella alpha-proteobacteria growth medium, bapgm). in this study, we describe the isolation of non-bartonella bacteria from aseptically obtained human blood and tissue samples that were inoculated into bapgm pre-enrichment culture medium, and were obtained during attemp ...200717889384
porin isolated from the outer membrane of erwinia amylovora and its encoding gene.a major erwinia amylovora outer-membrane protein (omp-ea) and the gene encoding for this protein (omp-ea) were isolated and characterized. the native omp-ea protein forms a trimeric structure of approximately 114 kda. this protein demonstrated high resistance to detergents such as sds and octyl-glucopyranoside, but disaggregated to monomers with a molecular weight (mw) of approximately 39 kda after heating at 95 degrees c for 10 minutes in sample buffer. the pore-forming ability of the oligomeri ...200717211539
tailoring structure-function properties of l-asparaginase: engineering resistance to trypsin cleavage.bacterial l-asnases (l-asparaginases) catalyse the conversion of l-asparagine into l-aspartate and ammonia, and are widely used for the treatment of all (acute lymphoblastic leukaemia). in the present paper, we describe an efficient approach, based on protein chemistry and protein engineering studies, for the construction of trypsin-resistant pegylated l-asnase from erwinia carotovora (ecal-asnase). limited proteolysis of ecal-asnase with trypsin was found to be associated with a first cleavage ...200717313368
amyloidogenesis of type iii-dependent harpins from plant pathogenic bacteria.harpins are heat-stable, glycine-rich type iii-secreted proteins produced by plant pathogenic bacteria, which cause a hypersensitive response (hr) when infiltrated into the intercellular space of tobacco leaves; however, the biochemical mechanisms by which harpins cause plant cell death remain unclear. in this study, we determined the biochemical characteristics of hpag, the first harpin identified from a xanthomonas species, under plant apoplast-like conditions using electron microscopy and cir ...200717314101
erwinia carotovora elicitors and botrytis cinerea activate defense responses in physcomitrella patens.vascular plants respond to pathogens by activating a diverse array of defense mechanisms. studies with these plants have provided a wealth of information on pathogen recognition, signal transduction and the activation of defense responses. however, very little is known about the infection and defense responses of the bryophyte, physcomitrella patens, to well-studied phytopathogens. the purpose of this study was to determine: i) whether two representative broad host range pathogens, erwinia carot ...200717922917
fusion of the genes for ahl-lactonase and s-layer protein in bacillus thuringiensis increases its ability to inhibit soft rot caused by erwinia carotovora.two genes, ctc and ctc2, responsible for surface layer (s-layer) protein synthesis in bacillus thuringiensis ctc, were mutated and resulted in b. thuringiensis tr5. to synthesize and express the n-acyl-homoserine lactonase (ahl-lactonase) in the extracellular space of b. thuringiensis, the aiia ( 4q7 ) gene (an ahl-lactonase gene from b. thuringiensis 4q7), which confers the ability to inhibit plant soft rot disease in b. thuringiensis 4q7, was fused with the upstream sequence of the ctc gene, w ...200717216466
anti-ice nucleation activity in xylem extracts from trees that contain deep supercooling xylem parenchyma cells.boreal hardwood species, including japanese white birch (betula platyphylla sukat. var. japonica hara), japanese chestnut (castanea crenata sieb. et zucc.), katsura tree (cercidiphyllum japonicum sieb. et zucc.), siebold's beech (fagus crenata blume), mulberry (morus bombycis koidz.), and japanese rowan (sorbus commixta hedl.), had xylem parenchyma cells (xpcs) that adapt to subfreezing temperatures by deep supercooling. crude extracts from xylem in all these trees were found to have anti-ice nu ...200717936742
exploring diversity among spanish strains of erwinia amylovora and possible infection sources.we have examined the intraspecific diversity of a collection of 63 spanish strains of erwinia amylovora, isolated from 1995 to 2001, to determine whether or not they could be grouped based on phenotypic or genotypic criteria and to investigate the sources of inoculum for fire blight dissemination in spain.200717953575
isomaltulose production using free cells: optimisation of a culture medium containing agricultural wastes and conversion in repeated-batch processes.the enzyme glucosyltransferase is an industrially important enzyme since it produces non-cariogenic isomaltulose (6-o-alpha-d-glucopyronosyl-1-6-d-fructofuranose) from sucrose by intramolecular transglucosylation. the experimental designs and response surface methodology (rsm) were applied for the optimisation of the nutrient concentrations in the culture medium for the production of glucosyltransferase by erwinia sp. d12 in shaken flasks at 200 rpm and 30 degrees c. a statistical analysis of th ...200717186209
increasing survival and efficacy of a bacterial biocontrol agent of fire blight of rosaceous plants by means of osmoadaptation.the efficacy of pseudomonas fluorescens eps62e in the biocontrol of erwinia amylovora, the causal agent of fire blight of apple and pear, depends on the colonization of plant surfaces after spray application. a procedure to increase cell survival in the phyllosphere was developed consisting of saline stress and osmolyte amendment to the growth medium during inoculum preparation. hyperosmotic stress induced the synthesis of the osmolytes trehalose, n-acetylglutaminylglutamine amide and glucosyl-g ...200717391328
transgenic tobacco expressing the hrpn(ep) gene from erwinia pyrifoliae triggers defense responses against botrytis cinerea.hrpn(ep), from the gram-negative pathogen, erwinia pyrifoliae, is a member of the harpin group of proteins, inducing pathogen resistance and hypersensitive cell death in plants. when the hrpn(ep) gene driven by the oscc1 promoter was introduced into tobacco plants via agrobacterium-mediated transformation, their resistance to the necrotrophic fungal pathogen, botrytis cinerea, increased. resistance to b. cinerea was correlated with enhanced induction of sa-dependent genes such as pr-1a, pr2, pr3 ...200717978576
rpos as an intermediate in rsma-dependent regulation of secondary antifungal metabolites biosynthesis in pseudomonas sp. m18.to investigate the regulatory mechanism governing antifungal metabolite biosynthesis, two kinds of global regulator genes in pseudomonas sp. m18, an rpos and an rsma gene, were cloned and mutated by inserting with an aacc1 cassette, respectively. two mutants showed the same regulatory mode with repression of phenazine-1-carboxylic acid and remarkable enhancement of pyoluteorin. in the rpos-mutant, a translational rsma'-'lacz fusion was expressed at the same level corresponding to that in the wil ...200717263850
quorum sensing in erwinia species.the term quorum sensing (qs) refers to the ability of bacteria to regulate gene expression according to the accumulation of signalling molecules that are made by every cell in the population. the erwiniae group of bacteria are often phytopathogens and the expression of a number of their important virulence determinants and secondary metabolites is under qs control. the erwiniae utilise two types of qs signalling molecules: n-acyl homoserine lactones and ai-2-type signalling molecules. here, we r ...200716943991
proteomic analysis of a non-virulent mutant of the phytopathogenic bacterium erwinia chrysanthemi deficient in osmoregulated periplasmic glucans: change in protein expression is not restricted to the envelope, but affects general metabolism.osmoregulated periplasmic glucans (opgs) are general constituents of the envelope of gram-negative bacteria. they are required for full virulence of bacterial phytopathogens such as pseudomonas syringae, xanthomonas campestris and erwinia chrysanthemi. e. chrysanthemi is a pectinolytic gamma-proteobacterium that causes soft rot disease on a wide range of plant species. in addition to the loss of virulence, opg mutants exhibit a pleiotropic phenotype that affects motility, bile-salt resistance, e ...200717322196
quorum sensing, virulence and secondary metabolite production in plant soft-rotting bacteria.quorum sensing describes the ability of bacteria to sense their population density and respond by modulating gene expression. in the plant soft-rotting bacteria, such as erwinia, an arsenal of plant cell wall-degrading enzymes is produced in a cell density-dependent manner, which causes maceration of plant tissue. however, quorum sensing is central not only to controlling the production of such destructive enzymes, but also to the control of a number of other virulence determinants and secondary ...200717360277
early chloroplastic alterations analysed by optical coherence tomography during a harpin-induced hypersensitive response.the hypersensitive response has been mostly studied by molecular and biochemical methods after sample destruction. the development of imaging techniques allows the monitoring of physiological changes before any signs of cell death. here, we follow the early steps of a hypersensitive-like response induced by the bacterial elicitor harpin in nicotiana sp. we describe cytological modifications after inoculation of the harpin protein, using confocal fluorescence microscopy (cfm) and optical coherenc ...200717376167
mode of action of glycoside hydrolase family 5 glucuronoxylan xylanohydrolase from erwinia chrysanthemi.the mode of action of xylanase a from a phytopathogenic bacterium, erwinia chrysanthemi, classified in glycoside hydrolase family 5, was investigated on xylooligosaccharides and polysaccharides using tlc, maldi-tof ms and enzyme treatment with exoglycosidases. the hydrolytic action of xylanase a was found to be absolutely dependent on the presence of 4-o-methyl-d-glucuronosyl (meglca) side residues in both oligosaccharides and polysaccharides. neutral linear beta-1,4-xylooligosaccharides and est ...200717381510
metabolic engineering of potato carotenoid content through tuber-specific overexpression of a bacterial mini-pathway.since the creation of "golden rice", biofortification of plant-derived foods is a promising strategy for the alleviation of nutritional deficiencies. potato is the most important staple food for mankind after the cereals rice, wheat and maize, and is extremely poor in provitamin a carotenoids.200717406674
clinical pharmacology of asparaginases in the united states: asparaginase population pharmacokinetic and pharmacodynamic (pk-pd) models (nonmem) in adult and pediatric all patients.in the past 25 years, effective new drugs along with better treatment decisions based on disease factors have resulted in significantly improved clinical outcomes in acute lymphoblastic leukemia. despite these successes in the last 2 decades, 15% to 25% of acute lymphoblastic leukemia patients relapse. therefore, better dosing therapies are still needed. insights in the pharmacokinetic and pharmacodynamic (pk-pd) contributions of licensed drugs may guide us into better protocol design and optima ...200717414566
a simple enzymatic synthesis of 4-nitrophenyl beta-1,4-d-xylobioside, a chromogenic substrate for assay and differentiation of endoxylanases.a simple procedure has been elaborated for preparation of 4-nitrophenyl beta-d-xylopyranosyl-1,4-beta-d-xylopyranoside (npx(2)), a chromogenic substrate of some endo-beta-1,4-xylanases. the procedure is based on a self-transfer reaction from 4-nitrophenyl beta-d-xylopyranoside catalyzed by an aureobasidium pullulans and aspergillus niger beta-xylosidases. both enzymes catalyzed only the formation of 4-nitrophenyl glycosides of beta-1,4-xylobiose with a small admixture of 4-nitrophenyl glycoside ...200717223215
epiphytic fitness of a biological control agent of fire blight in apple and pear orchards under mediterranean weather conditions.the behaviour of pseudomonas fluorescens eps62e was investigated in apple and pear orchards under mediterranean climatic conditions. the trials studied the influence of weather conditions, plant host species, presence of indigenous microbial community and spread from treated to nontreated trees on colonization and survival. population dynamics were assessed by real-time pcr and cfu-counting methods. with inoculated flowers, weather conditions were optimal for colonization, and eps62e established ...200717233751
contained metabolic engineering in tomatoes by expression of carotenoid biosynthesis genes from the plastid genome.applications of chloroplast engineering in agriculture and biotechnology will depend critically on success in extending the crop range of chloroplast transformation, and on the feasibility of expressing transgenes in edible organs (such as tubers and fruits), which often are not green and thus are much less active in chloroplast gene expression. we have improved a recently developed chloroplast-transformation system for tomato plants and applied it to engineering one of the central metabolic pat ...200717241450
the hrpn(ea) harpin from erwinia amylovora triggers differential responses on the nonhost arabidopsis thaliana cells and on the host apple cells.erwinia amylovora is a gram-negative necrogenic bacterium causing fire blight of the maloideae subfamily of rosaceae such as apple and pear. it provokes progressive necrosis in aerial parts of susceptible host plants (compatible interaction) and a hypersensitive reaction (hr) when infiltrated in nonhost plants (incompatible interaction). the hrpn(ea) harpin is a type three secretion system effector secreted by e. amylovora. this protein is involved in pathogenicity and hr-eliciting capacity of e ...200717249426
identification and functional analysis of a phytoene desaturase gene from the extremely radioresistant bacterium deinococcus radiodurans.the phytoene-related desaturases are the key enzymes in the carotenoid biosynthetic pathway. the gene encoding phytoene desaturase in the deinoxanthin synthesis pathway of deinococcus radiodurans was identified and characterized. two putative phytoene desaturase homologues (dr0861 and dr0810) were identified by analysis of conserved amino acid regions, and the former displayed the highest identity (68 %) with phytoene desaturase of the cyanobacterium gloeobacter violaceus. dr0861 gene knockout a ...200717464079
[physico-chemical properties of temperate bacteriophage zf40 of erwinia carotovora].a method of efficient purification of the extremely instable virions of the temperate bacteriophage zf40 of erwinia carotovora was proposed in the work. the stage-by-stage centrifugation in mentrizamide and caesium chloride gradients permitted to obtain highly purified phage preparations which were used for studying the protein composition of the studied erwiniophage. it was established that the buoyant density of the phage zf40 was 1.23 g/cm3, 1.49 g/cm3 and 1.27 g/cm3 in the gradients of metri ...200717494330
[nature of the cryptic plasmid pca25 of erwinia carotovora subsp. carotovora 48a].high specificity of tn9 transposition into the cryptic plasmid pca25 of erwinia carotovora subsp. carotovora 48a was established on the basis of the comparative restriction analysis of dna by endonucleases ecorv and psti. under the extremal conditions of growth (1% sds) the plasmid pca25:: tn9 loses about 50 % of transpozone sequence, however the cells are not healed of extrachromosomal dna. the inheritance stability, side by side with site-specific transposition and deleting of tn9, confirms a ...200717494331
the map kinase kinase mkk2 affects disease resistance in arabidopsis.the arabidopsis mitogen-activated protein kinase (mapk) kinase 2 (mkk2) was shown to mediate cold and salt stress responses through activation of the two map kinases mpk4 and mpk6. transcriptome analysis of plants expressing constitutively active mkk2 (mkk2-ee plants) showed altered expression of genes induced by abiotic stresses but also a significant number of genes involved in defense responses. both mpk4 and mpk6 became rapidly activated upon pseudomonas syringae pv. tomato dc3000 infection ...200717506336
recombinant dna technology in apple.this review summarizes the achievements of almost 20 years of recombinant dna technology applied to apple, grouping the research results into the sections: developing the technology, insect resistance, fungal disease resistance, self-incompatibility, herbicide resistance, fire blight resistance, fruit ripening, allergens, rooting ability, and acceptance and risk assessment. the diseases fire blight, caused by erwinia amylovora, and scab, caused by venturia inaequalis, were and still are the prim ...200717522823
results of the dana-farber cancer institute all consortium protocol 95-01 for children with acute lymphoblastic leukemia.the dana-farber cancer institute (dfci) childhood all consortium protocol 95-01 was designed to minimize therapy-related morbidity for children with newly diagnosed all without compromising efficacy. patients participated in randomized comparisons of (1) doxorubicin given with or without dexrazoxane, a cardioprotectant (high-risk patients), (2) intensive intrathecal chemotherapy and cranial radiation (standard-risk patients), and (3) erwinia and escherichia coli asparaginase (all patients). betw ...200717003366
characterization of a broad range antibacterial substance from a new bacillus species isolated from amazon basin.a bacillus sp. strain producing a bacteriocin-like substance was characterized by biochemical profiling and 16s rdna sequencing. the phylogenetic analysis indicated that this strain has low sequence similarity with most bacillus spp., suggesting a new species was isolated. the antimicrobial activity was detected starting at the exponential growth phase, and maximum activity was observed at stationary phase. the substance was inhibitory to a broad range of indicator strains, including pathogenic ...200717534601
identification and characterization of a novel periplasmic polygalacturonic acid binding protein from yersinia enterolitica.a number of bacteria in the family enterobacteriaceae harbor the genes comprising well-developed pectinolytic pathways (e.g. erwinia sp.) or abridged versions of this pathway (e.g. yersinia sp.). one of the most enigmatic components present in some of these pathways is a small gene that encodes a predicted secreted protein of approximately 160 amino acid residues with unknown function. this protein shows distant amino acid sequence similarity over its entire length to galactose-specific family 3 ...200717292916
modeling the onset of virulence in a pectinolytic bacterium.building up from experimental knowledge of the regulatory network of the pel genes in the bacteria e. chrysanthemi, we propose for the first time a qualitative modeling of the infectious transition of this bacteria when it is hosted in a plant. we show that this infectious transition can be understood as the excitable dynamics of a metabolico-genetic network. our mathematical model can account for the main phases which are observed in the onset of the pathogenecity by erwinia chrysanthemi, namel ...200717005207
differential regulation of two oligogalacturonate outer membrane channels, kdgn and kdgm, of dickeya dadantii (erwinia chrysanthemi).the entry of oligogalacturonates into dickeya dadantii occurs through the specific channel kdgm. the genome of the bacterium encodes a second member of this family of outer membrane proteins, kdgn. we showed that this protein is also involved in the uptake of oligogalacturonates. when kdgn was reconstituted in proteoliposomes, it formed channels with a conductance of about 450 ps at a positive potential. these channels had weak anionic selectivity. the regulation of kdgn is complex, and five gen ...200717573480
comparison of specificity and sensitivity of immunochemical and molecular techniques for reliable detection of erwinia amylovora.erwinia amylovora [(burrill) winslow et al.] (ea), the causal agent of fire blight, was detected in plant samples and pure bacterial cultures by means of pcr, ifas and elisa. polyclonal antibodies of neogen europe ltd. were used for ifas and pta-elisa and laboratory-generated primers eaf72 and ear560 for pcr. using the biolog system and an immature pear fruit assay, identities of all ea strains were confirmed as the fire blight bacterium. in assays of pure ea cultures, pta-elisa, and both ifas a ...200717575916
inhibition of quorum sensing-regulated behaviors by scorzonera sandrasica.many gram-negative bacteria use n-acyl homoserine lactone signal molecules to monitor their own population density and coordinate gene regulation in a process called quorum sensing (qs). increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested 46 terrestrial plants materials for their ability to inhibit qs-regulated behaviors in different bacterial species. plant materials were dried and extracted using different solvents. the chloroform-solubl ...200717597339
using aqueous chlorine dioxide to prevent contamination of tomatoes with salmonella enterica and erwinia carotovora during fruit washing.chlorine dioxide (clo2) is an antimicrobial agent recognized for its disinfectant properties. in this study, the sanitizing effects of clo2 solutions against salmonella enterica and erwinia carotovora in water, on tomato surfaces, and between loads of tomatoes were evaluated. in water, clo2 at 5, 10, and 20 ppm caused a > or = 5-log reduction of s. enterica within 6, 4, and 2 s, respectively. higher lethality was observed with e. carotovora; a 5-log reduction was achieved after only 2 s with 10 ...200717388051
sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related prms protein in rice plants.expression of pathogenesis-related (pr) genes is part of the plant's natural defense response against pathogen attack. the prms gene encodes a fungal-inducible pr protein from maize. here, we demonstrate that expression of prms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (magnaporthe oryzae, fusarium verticillioides, and helminthosporium oryzae) and bacterial (erwinia chrysanthemi) pathogens. the prms-mediated disease resistance in rice plants is asso ...200717601170
characterization of the erwinia chrysanthemi gan locus, involved in galactan catabolism.beta-1,4-galactan is a major component of the ramified regions of pectin. analysis of the genome of the plant pathogenic bacteria erwinia chrysanthemi revealed the presence of a cluster of eight genes encoding proteins potentially involved in galactan utilization. the predicted transport system would comprise a specific porin ganl and an abc transporter made of four proteins, ganfgk(2). degradation of galactans would be catalyzed by the periplasmic 1,4-beta-endogalactanase gana, which released o ...200717644603
gliding arc discharge in the potato pathogen erwinia carotovora subsp. atroseptica: mechanism of lethal action and effect on membrane-associated molecules.gliding arc (glidarc) discharge is a physicochemical technique for decontamination at atmospheric pressure and ambient temperature. it leads to the destruction of bacterial phytopathogens responsible for important losses in industrial agriculture, namely, erwinia spp., without the formation of resistant forms. we investigated the effect of a novel optimized prototype allowing bacterial killing without lag time. this prototype also decreases the required duration of treatment by 50%. the study of ...200717644644
distinct and overlapping binding sites of pseudomonas aeruginosa hfq and rsma proteins on the non-coding rna rsmy.in pseudomonas aeruginosa the rsm system is involved in regulation of quorum-sensing and virulence gene expression. our recent studies revealed that the stability and abundance of the non-coding rna rsmy, which antagonizes the translational regulator rsma, is dependent on hfq. here, we show that hfq and rsma bind concurrently to rsmy. enzymatic probing of rsmy rna in the presence of rsma and hfq verified the proposed -gga- motifs as rsma binding sites and located hfq binding sites in single-stra ...200717141182
[preliminary characteristic of dna-containing virus-like particles of erwinia carotovora].dna-containing particles formed by the expression of the defect prophages of e. carotovora subsp. carotovora (ecc) have been revealed for the first time. two types of virus-like particles (vlp) occur in this phytopathogenic bacterium. capsides of the first type vlp are weakly identified at agarose electrophoretic separation while dna released from them are presented by distinct reflexes. mobility of the second type particles is close to that of separate capsids of the temperate phage zf40. dna p ...200717682527
atptr3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in arabidopsis.mutation in the wound-induced peptide transporter gene atptr3 (at5g46050) of arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. the heterologous expression in yeast was utilized to verify that the atptr3 protein transports di-and tripeptides. the t-dna insert in the atptr3-1 mutant in the arabidopsis ecotype c24 revealed two t-dna copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the atptr3 gene. an a ...200717143616
pharmacoanalytical assays of erwinia asparaginase (erwinase) and pharmacokinetic results in high-risk acute lymphoblastic leukemia (hr all) patients: simulations of erwinase population pk-pd models.asparaginases are the cornerstone therapy of many successful combination regimens for the treatment of acute lymphoblastic leukemia (all), the most common malignancy in children and adolescents. currently, two asparaginase formulations are available in the us, native escherichia coli asparaginase (asnase) and pegaspargase. a third formulation native erwinia asparaginase (erwinase, erw) has recently been made available under a licensing exception for personal use. we report here the development a ...200717695416
involvement of cathepsin b in the plant disease resistance hypersensitive response.a diverse range of plant proteases are implicated in pathogen perception and in subsequent signalling and execution of disease resistance. we demonstrate, using protease inhibitors and virus-induced gene silencing (vigs), that the plant papain cysteine protease cathepsin b is required for the disease resistance hypersensitive response (hr). vigs of cathepsin b prevented programmed cell death (pcd) and compromised disease resistance induced by two distinct non-host bacterial pathogens. it also su ...200717697096
erwinia carotovora evf antagonizes the elimination of bacteria in the gut of drosophila larvae.erwinia virulence factor (evf) has been identified in erwinia carotovora carotovora 15 (ecc15) as a virulence factor that promotes colonization of the drosophila larval gut and provokes the triggering of a systemic immune response. here we have analysed how evf promotes persistence and colonization of bacteria inside the larval gut. erwinia evf mutants do not persist in immune-deficient drosophila, indicating that evf does not act by counteracting immunity. the results indicated that evf is not ...200716879453
production of soft rot resistant calla lily by expressing a ferredoxin-like protein gene (pflp) in transgenic plants.an efficient protocol for the agrobacterium tumefaciens-mediated transformation of calla lily (zantedeschia elliottiana (w. wats.) engl. cultivar 'florex gold') is described. shoot basal discs were co-cultivated with a. tumefaciens c58c1 carrying a plasmid containing neomycin phosphotransferase (nptii) and plant ferredoxin-like protein (pflp) genes. after agrobacterium co-cultivation, the shoot basal discs were exposed to 100 mg l(-1) kanamycin for selection. twenty-eight out of 260 discs (10.8% ...200717033825
l-asparaginase from erwinia chrysanthemi 3937: cloning, expression and characterization.bacterial l-asparaginases (l-asnases) catalyze the conversion of l-asparagine to l-aspartate and ammonia. in the present work, we report the cloning and expression of l-asparaginase from erwinia chrysanthemi 3937 (erl-asnase) in escherichia coli bl21(de3)plyss. the enzyme was purified to homogeneity in a single-step procedure involving cation exchange chromatography on an s-sepharose ff column. the enzymatic and structural properties of the recombinant enzyme were investigated and the kinetic pa ...200716984804
autoinducer-2 of the fire blight pathogen erwinia amylovora and other plant-associated bacteria.autoinducers are important for cellular communication of bacteria. the luxs gene has a central role in the synthesis of autoinducer-2 (ai-2). the gene was identified in a shotgun library of erwinia amylovora and primers designed for pcr amplification from bacterial dna. supernatants of several erwinia amylovora strains were assayed for ai-2 activity with a vibrio harveyi mutant and were positive. many other plant-associated bacteria also showed ai-2 activity such as erwinia pyrifoliae and erwini ...200717092294
application of response surface methodology to cell immobilization for the production of palatinose.response surface methodology (rsm), based on multivariate non-linear model, was applied to study the interactions and optimization of the immobilization parameters for cell entrapment, namely alginate concentration, cell loading and bead diameter using erwinia rhapontici ncppb 1578 that produced palatinose. anova analysis and statistical parameters calculations showed that rsm could be used effectively to model and improve a complex system like cell immobilization. palatinose yield was increased ...200717113282
tobacco nectaries express a novel nadph oxidase implicated in the defense of floral reproductive tissues against microorganisms.hydrogen peroxide produced from the nectar redox cycle was shown to be a major factor contributing to inhibition of most microbial growth in floral nectar; however, this obstacle can be overcome by the floral pathogen erwinia amylovora. to identify the source of superoxide that leads to hydrogen peroxide accumulation in nectary tissues, nectaries were stained with nitroblue tetrazolium. superoxide production was localized near nectary pores and inhibited by diphenylene iodonium but not by cyanid ...200717114277
bacteria associated with orchid roots and microbial production of auxin.associative bacteria of terrestrial (paphiopedilum appletonianum) and epiphytic (pholidota articulata) tropical orchids were investigated. microbial community of epiphytic plant differed from that of the terrestrial one. streptomyces, bacillus, pseudomonas, burkholderia, erwinia and nocardia strains populated paphiopedilum roots, whereas pseudomonas, flavobacterium, stenotrophomonas, pantoea, chryseobacterium, bacillus, agrobacterium, erwinia, burkholderia and paracoccus strains colonized pholid ...200717140781
investigations into the in vitro antimicrobial activity and mode of action of the phenazine antibiotic d-alanylgriseoluteic acid.d-alanylgriseoluteic acid (aga) is a potent antimicrobial phenazine compound produced by pantoea agglomerans (erwinia herbicola) eh1087. susceptibility tests against a range of microbes indicated that aga had a broad spectrum of antimicrobial activity and was particularly active against gram-positive pathogens. comparison of the in vitro efficacy of aga with eight other antibiotics against 119 clinical isolates of streptococcus pneumoniae demonstrated that all were inhibited by low concentration ...200717189100
proteomic analysis of the carbonate insoluble outer membrane fraction of the soft-rot pathogen dickeya dadantii (syn. erwinia chrysanthemi) strain 3937.we present results of the first comprehensive proteomic analysis of the outer membrane of the bacterial phytopathogen dickeya dadantii strain 3937 and its response to virulence-contributing factors such as host plant extract, acidic stress, and iron starvation. we analyzed the carbonate-insoluble membrane fractions, which are highly enriched for outer membrane proteins, using two-dimensional electrophoresis and identified the proteins by maldi-tof ms. forty unique proteins were identified, some ...200717203949
a comparison of enzymatic phosphorylation and phosphatidylation of beta-l- and beta-d-nucleosides.enzymatic 5'-monophosphorylation and 5'-phosphatidylation of a number of beta-l- and beta-d-nucleosides was investigated. the first reaction, catalyzed by nucleoside phosphotransferase (npt) from erwinia herbicola, consisted of the transfer of the phosphate residue from p-nitrophenylphosphate (p-npp) to the 5'-hydroxyl group of nucleoside; the second was the phospholipase d (pld)-catalyzed transphosphatidylation of l-alpha-lecithin with a series of beta-l- and beta-d-nucleosides as the phosphati ...200717206374
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