| a fast spheroplast formation procedure in some 2,5-diketo-d-gluconate- and 2-keto-l-gulonate- producing bacteria. | calcium 2-keto-l-gulonate (ca-2-klg, a key intermediate in vitamin c synthesis) is produced from calcium 2,5-diketo d-gluconate (ca-2,5-dkg) by a variety of bacteria. a few bacterial species which efficiently convert glucose to ca-2,5-dkg have been isolated in our laboratory. our bacterial collection included species that possess the genes for production of ca-2-klg from ca-2,5-dkg; however, the yield of the former is poor. a procedure for the preparation of spheroplasts in ca-2,5-dkg- and ca-2- ... | 1989 | 2517394 |
| phospholipase c of pseudomonas chlororaphis and its toxicity for insects. | | 1973 | 4710012 |
| nitrile hydratase gene from rhodococcus sp. n-774 requirement for its downstream region for efficient expression. | for improvement of the production of nitrile hydratase (nhase) from rhodococcus sp. n-774 by recombinant dna techniques, several plasmids, each of which had a deletion of the upstream or downstream region of the genes encoding the alpha and beta subunits of nhase, were constructed. enzyme assays of recombinant r. rhodochrous and escherichia coli cells showed that a downstream region of the nhase genes was indispensable for the production of active nhase in both cells, but for the production of t ... | 1994 | 7765511 |
| physical, biochemical, and immunological characterization of a thermostable amidase from klebsiella pneumoniae nctr 1. | an amidase capable of degrading acrylamide and aliphatic amides was purified to apparent homogeneity from klebsiella pneumoniae nctr 1. the enzyme is a monomer with an apparent molecular weight of 62,000. the ph and temperature optima of the enzyme were 7.0 and 65 degrees c, respectively. the purified amidase contained 11 5,5-dithiobis(2-nitrobenzoate) (dtnb)-titratable sulfhydryl (sh) groups. in the native enzyme 1.0 sh group readily reacted with dtnb with no detectable loss of activity. titrat ... | 1996 | 8636044 |
| conservation of the multidrug resistance efflux gene oprm in pseudomonas aeruginosa. | an intragenic probe derived from the multidrug resistance gene oprm hybridized with genomic dna from all 20 serotypes of pseudomonas aeruginosa and from all 34 environmental and clinical isolates tested, indicating that the mexa-mexb-oprm multidrug efflux system is highly conserved in this organism. the oprm probe also hybridized with genomic dna from pseudomonas aureofaciens, pseudomonas chlororaphis, pseudomonas syringae, burkholderia pseudomallei, and pseudomonas putida, suggesting that efflu ... | 1997 | 9087505 |
| chlorocatechols substituted at positions 4 and 5 are substrates of the broad-spectrum chlorocatechol 1,2-dioxygenase of pseudomonas chlororaphis rw71. | the nucleotide sequence of a 10,528-bp region comprising the chlorocatechol pathway gene cluster tetrtetcdef of the 1,2,3,4-tetrachlorobenzene via the tetrachlorocatechol-mineralizing bacterium pseudomonas chlororaphis rw71 (t. potrawfke, k. n. timmis, and r.-m. wittich, appl. environ. microbiol. 64:3798-3806, 1998) was analyzed. the chlorocatechol 1,2-dioxygenase gene tetc was cloned and overexpressed in escherichia coli. the recombinant gene product was purified, and the alpha,alpha-homodimeri ... | 2001 | 11208799 |
| intact soil-core microcosms compared with multi-site field releases for pre-release testing of microbes in diverse soils and climates. | intact soil-core microcosms were used to compare persistence of pseudomonas chlororaphis 3732rn-l11 in fallow soil and on wheat roots with field releases at diverse sites. parallel field and microcosm releases at four sites in 1996 were repeated with addition of one site in 1997. microcosms were obtained fresh and maintained at 60% soil water holding capacity in a growth chamber at 70% relative humidity, a 12-hour photoperiod, and constant temperature. persistence of 3732rn-l11 was measured at e ... | 2001 | 11315115 |
| fitness of salmonella enterica serovar thompson in the cilantro phyllosphere. | the epiphytic fitness of salmonella enterica was assessed on cilantro plants by using a strain of s. enterica serovar thompson that was linked to an outbreak resulting from cilantro. salmonella serovar thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (clsm) at high densities on the veins and in natural lesions. the population sizes of two common colonizers of plant surfaces, pantoea agglomerans and pseudomonas chloro ... | 2002 | 12089050 |
| pseudomonas frederiksbergensis sp. nov., isolated from soil at a coal gasification site. | phenotypic and genotypic characterization indicated that a group of 29 closely related phenanthrene-degrading bacteria from a coal gasification site in frederiksberg, copenhagen, denmark, belonged to the genus pseudomonas. the strains were isolated at two sampling occasions 2 years apart. the isolates were phenotypically different from any known species of the genus pseudomonas and were therefore subject to further identification. colonies were smooth and pale yellowish and did not produce pigme ... | 2000 | 11155968 |
| root colonization by phenazine-1-carboxamide-producing bacterium pseudomonas chlororaphis pcl1391 is essential for biocontrol of tomato foot and root rot. | the phenazine-1-carboxamide-producing bacterium pseudomonas chlororaphis pcl1391 controls tomato foot and root rot caused by fusarium oxysporum f. sp. radicislycopersici. to test whether root colonization is required for biocontrol, mutants impaired in the known colonization traits motility, prototrophy for amino acids, or production of the site-specific recombinase, sss/xerc were tested for their root tip colonization and biocontrol abilities. upon tomato seedling inoculation, colonization muta ... | 2000 | 11106026 |
| the complex structure of ferri-ferribactins. | by comparison of the nmr data of the ferribactins from pseudomonas chlororaphis atcc 9446 and of p. fluorescens 18.1 with those of their ga3+-complexes as models for the fe3+-complexes it will be shown that only two bidentate ligands are provided for complexation, both located in the peptide chain. the two remaining free sites of the octahedral metal ion are probably occupied by solvent molecules. | 2000 | 11098840 |
| degradation of triphenyltin by a fluorescent pseudomonad. | triphenyltin (tpt)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3',4',7-tetrahydroxyflavone as a post-column reagent for determination of tpt and its metabolite, diphenyltin (dpt). an isolated strain, strain cnr15, was identified as pseudomonas chlororaphis on the basis of its morphological and biochemical features. the incubation of strain cnr15 in a medium containing glycerol, succinate, and 130 microm tpt resulted in ... | 2000 | 10919812 |
| inactivation of gacs does not affect the competitiveness of pseudomonas chlororaphis in the arabidopsis thaliana rhizosphere. | quorum-sensing-controlled processes are considered to be important for the competitiveness of microorganisms in the rhizosphere. they affect cell-cell communication, biofilm formation, and antibiotic production, and the gacs-gaca two-component system plays a role as a key regulator. in spite of the importance of this system for the regulation of various processes, strains with a gac(-) phenotype are readily recovered from natural habitats. to analyze the influence of quorum sensing and the influ ... | 2003 | 12620875 |
| the polyester polyurethanase gene (puea) from pseudomonas chlororaphis encodes a lipase. | a gene (puea, polyurethane esterase a) encoding an extracellular polyurethanase (puea) was cloned from pseudomonas chlororaphis into escherichia coli. the enzyme secreted from e. coli showed esterase activity when assayed with p-nitrophenyl acetate. subcloning of a 3. 2-kb sali-ecori fragment into a t7 rna polymerase expression vector (pt7-6) produced a (35)s-labeled protein of 65 kda. nucleotide sequencing of puea showed an open reading frame encoding a 65-kda protein of 617 amino acid residues ... | 2000 | 10754242 |
| 5-cyanovaleramide production using immobilized pseudomonas chlororaphis b23. | a biocatalytic process for the hydration of adiponitrile to 5-cyanovaleramide has been developed which can be run to higher conversion, produces more product per weight of catalyst, and generates significantly less waste products than alternate chemical processes. the biocatalyst consists of pseudomonas chlororaphis b23 microbial cells immobilized in calcium alginate beads. the cells contain a nitrile hydratase (ec 4.2.1.84) which catalyzes the hydration of adiponitrile to 5-cyanovaleramide with ... | 1999 | 10579532 |
| colonization pattern of the biocontrol strain pseudomonas chlororaphis ma 342 on barley seeds visualized by using green fluorescent protein. | pseudomonas chlororaphis ma 342 is a potent biocontrol agent that can be used against several seed-borne diseases of cereal crops, including net blotch of barley caused by the fungus drechslera teres. in this study, strain ma 342 was tagged with the gfp gene (encoding the green fluorescent protein) in order to study the fate of cells after seed inoculation. the gfp-tagged strain, ma 342g2, had the same biocontrol efficacy as the wild type when it was applied at high cell concentrations to seeds ... | 1999 | 10427065 |
| comparative taxonomy of crystallogenic strains of pseudomonas aeruginosa and pseudomon as chlororaphis. | haynes, william c. (northern utilization research and development division, peoria, ill.) and lenora j. rhodes. comparative taxonomy of crystallogenic strains of pseudomonas aeruginosa and pseudomonas chlororaphis. j. bacteriol. 84:1080-1084. 1962.-only 11 of 39 strains received in the agricultural research service culture collection under the designation pseudonomas chlororaphis proved to be authentic; 28 were typical, pyocyanogenic strains of p. aeruginosa. the reason for this disproportionate ... | 1962 | 13963593 |
| degradation of 1,2,3,4-tetrachlorobenzene by pseudomonas chlororaphis rw71 | pseudomonas chlororaphis rw71 mineralized 1,2,3,4-tetrachlorobenzene, a highly recalcitrant pollutant hitherto not known to be degraded by pure cultures, as a sole source of carbon and energy, thereby releasing stoichiometric amounts of chloride. the transient excretion of tetrachlorocatechol in the early growth phase suggests an initial attack by a dioxygenase to form the corresponding dihydrodiol which rearomatizes to the catechol. the activity of chlorocatechol 1,2-dioxygenase in crude cell e ... | 1998 | 9758802 |
| phylogenetic relationships of pseudomonas putida strains deduced from the nucleotide sequences of gyrb, rpod and 16s rrna genes. | phylogenetic analysis of 20 pseudomonas strains (pseudomonas putida, pseudomonas fluorescens and pseudomonas chlororaphis) was conducted by using the nucleotide sequences of the genes for 16s rna, dna gyrase b subunit (gyrb) and rna polymerase delta 70 factor (rpod), which have been determined by the direct sequencing of pcr-amplified fragments. on the basis of gyrb and rpod sequences, these strains were split into two major clusters: one including the type strain of p. putida and all biovar a s ... | 1998 | 9734035 |
| channel specificity and secondary structure of the glucose-inducible porins of pseudomonas spp. | the oprb porin-mediated glucose transport system was investigated in pseudomonas chlororaphis, burkholderia cepacia, and pseudomonas fluorescens. kinetic studies of [u-14c]glucose uptake revealed an inducible system of low km values (0.3-5 microm) and high specificity for glucose. oprb homologs were purified and reconstituted into proteoliposomes. the porin function and channel preference for glucose were demonstrated by liposome swelling assays. examination of the periplasmic glucose-binding pr ... | 1998 | 9733092 |
| microbial counts and invert sugars in juice extracts from stored tubers of cyperus esculentus linn. (earth almond). | the microbial populations and the levels of invert sugars in juice extracts from healthy tubers of cyperus esculentus l. stored at 10, 20, 30 and 40 degrees c were determined. bacterial counts increased with time and attained the peak on the 25th and 35th d at 40 and 30 degrees c respectively. similar trends were obtained for the yeasts, but the peak counts were recorded on the 20th and 35th d at 40 and 30 degrees c respectively. at 10 and 20 degrees c, the counts, both for bacteria and yeasts i ... | 1993 | 8121474 |
| amidase coupled with low-molecular-mass nitrile hydratase from rhodococcus rhodochrous j1. sequencing and expression of the gene and purification and characterization of the gene product. | the cloned 9.4-kb insert of plasmid pnhj20l containing low-molecular-mass nitrile hydratase (l-nhase) gene from rhodococcus rhodochrous j1 [kobayashi, m. et al. (1991) biochim. biophys. acta 1129, 23-33] was digested with various restriction enzymes, and the trimmed fragments were inserted into puc18 or puc19. a 1.96-kb ecori-sphi region located 1.9-kb downstream of the l-nhase gene was found to be essential for the expression of amidase activity in escherichia coli; the gene arrangement of the ... | 1993 | 7916690 |
| metabolism of guanidinosuccinic acid. i. characterization of a specific amidino hydrolase from pseudomonas chlororaphis. | | 1972 | 4651648 |
| phenazines and other redox-active antibiotics promote microbial mineral reduction. | natural products with important therapeutic properties are known to be produced by a variety of soil bacteria, yet the ecological function of these compounds is not well understood. here we show that phenazines and other redox-active antibiotics can promote microbial mineral reduction. pseudomonas chlororaphis pcl1391, a root isolate that produces phenazine-1-carboxamide (pcn), is able to reductively dissolve poorly crystalline iron and manganese oxides, whereas a strain carrying a mutation in o ... | 2004 | 14766572 |
| nitrile hydratase of pseudomonas chlororaphis b23. purification and characterization. | nitrile hydratase of pseudomonas chlororaphis b23 was completely stabilized by the addition of 22 mm n-butyric acid. the enzyme was purified from extracts of methacrylamide-induced cells of p. chlororaphis b23 in eight steps. at the last step, the enzyme was crystallized by adding ammonium sulfate. the crystallized enzyme appeared to be homogeneous from analysis by polyacrylamide gel electrophoresis, analytical ultracentrifuge, and double diffusion in agarose. the enzyme has a molecular mass of ... | 1987 | 3830164 |
| occurrence of a cobalt-induced and cobalt-containing nitrile hydratase in rhodococcus rhodochrous j1. | the formation of nitrile hydratase required cobalt ions in rhodococcus rhodochrous j1. no other transition-metals could replace the cobalt ion. the rhodococcus nitrile hydratase was purified to homogeneity and found to contain a cobalt atom. the occurrence of a cobalt-induced and cobalt-containing nitrile hydratase, different from the nitrile hydratases in pseudomonas chlororaphis b23 and brevibacterium r312 containing a ferric ion in their active center, has been demonstrated here for the first ... | 1988 | 3421954 |
| phosphate-selective porins from the outer membranes of fluorescent pseudomonas sp. | phosphate starvation induced oligomeric proteins from the outer membranes of pseudomonas fluorescens, pseudomonas putida, pseudomonas aureofaciens, and pseudomonas chlororaphis were purified to homogeneity. the incorporation of the purified proteins into planar lipid bilayer membranes resulted in stepwise increases in membrane conductance. single channel conductance experiments demonstrated that these proteins were all capable of forming small channels, similar to the pseudomonas aeruginosa phos ... | 1987 | 2436733 |
| cloning and characterization of genes responsible for metabolism of nitrile compounds from pseudomonas chlororaphis b23. | the nitrile hydratase (nhase) of pseudomonas chlororaphis b23, which is composed of two subunits, alpha and beta, catalyzes the hydration of nitrile compounds to the corresponding amides. the nhase gene of strain b23 was cloned into escherichia coli by the dna-probing method with the nhase gene of rhodococcus sp. strain n-774 as the hybridization probe. nucleotide sequencing revealed that an amidase showing significant similarity to the amidase of rhodococcus sp. strain n-774 was also coded by t ... | 1991 | 2013568 |
| nitrous oxide as end product of denitrification by strains of fluorescent pseudomonads. | growing cultures of several strains of pseudomonas fluorescens and pseudomonas chlororaphis produced n2o as the only detectable gaseous product of denitrification, and other strains produced n2 as the gaseous end product of denitrification. all of the nitrogen in no3- or no2- added to cell suspensions of the n2o-producing strains p. fluorescens pj 185 and p. chlororaphis b-560 was recovered as n2o. all of the nitrogen in no3- or no2- added to cell suspensions of the n2-producing strain p. fluore ... | 1977 | 195699 |
| [using lux genes marker technique to track pseudomonas chlororaphis pl9l in cotton rhizosphere]. | tn7-luxcdabe marker system was successfully transferred into pseudomonas chlororaphis (strain pl9) by means of transformation and conjugation and a stable lux-marked strain pl9l was obtained. the colonizing dynamics and distribution of the luminescent bacteria pl9l in the rhizosphere of cotton planted in pots and rhizoboxes were studied by the methods of x-ray film imaging and enumeration of luminescent colonies on agar media, the results of pot culture experiment showed that pl9l successfully c ... | 1999 | 12555400 |
| predicting survival of a genetically engineered microorganism, pseudomonas chlororaphis 3732rn-l11, in soil and wheat rhizosphere across canada with linear multiple regression models. | pseudomonas chlororaphis 3732rn-l11 survival rates in soil and wheat rhizosphere were measured using intact soil core microcosms representing 23 sites across canada. linear multiple regression (lmr) models were developed to predict the survival rate of this genetically engineered microorganism (gem) as a function of soil parameters measured at the time of microcosm inoculation. lmr models were tested by comparing their predicted survival rates with observed survival rates from environmental intr ... | 2002 | 12381028 |
| biomonitoring of pjp4-carrying pseudomonas chlororaphis with trb protein-specific antisera. | the transfer of catabolic genes on conjugative plasmids to indigenous organisms from which they may spread further into the community allows the introduction of new biodegradative pathways for metabolic conversion of pollutants to the community. biomonitoring of incp plasmid pjp4-carrying pseudomonas chlororaphis from the rhizosphere of arabidopsis thaliana was achieved using antisera specific for proteins from the plasmid transfer machinery. antisera were generated that recognized trbc and trbf ... | 2001 | 11846762 |
| functional analysis of genes for biosynthesis of pyocyanin and phenazine-1-carboxamide from pseudomonas aeruginosa pao1. | two seven-gene phenazine biosynthetic loci were cloned from pseudomonas aeruginosa pao1. the operons, designated phza1b1c1d1e1f1g1 and phza2b2c2d2e2f2g2, are homologous to previously studied phenazine biosynthetic operons from pseudomonas fluorescens and pseudomonas aureofaciens. functional studies of phenazine-nonproducing strains of fluorescent pseudomonads indicated that each of the biosynthetic operons from p. aeruginosa is sufficient for production of a single compound, phenazine-1-carboxyl ... | 2001 | 11591691 |
| phenazine-1-carboxamide production in the biocontrol strain pseudomonas chlororaphis pcl1391 is regulated by multiple factors secreted into the growth medium. | pseudomonas chlororaphis pcl1391 controls tomato foot and root rot caused by fusarium oxysporum f. sp. radicis-lycopersici. the production of phenazine-1-carboxamide (pcn) is crucial for this biocontrol activity. in vitro production of pcn is observed only at high-population densities, suggesting that production is under the regulation of quorum sensing. the main autoinducer molecule produced by pcl1391 was identified structurally as n-hexanoyl-l-homoserine lactone (c6-hsl). the two other autoin ... | 2001 | 11497469 |
| introduction of the phzh gene of pseudomonas chlororaphis pcl1391 extends the range of biocontrol ability of phenazine-1-carboxylic acid-producing pseudomonas spp. strains. | pseudomonas chlororaphis pcl1391 controls tomato foot and root rot caused by fusarium oxysporum f. sp. radicis-lycopersici. its biocontrol activity is mediated by the production of phenazine-1-carboxamide (pcn). in contrast, the take-all biocontrol strains p. fluorescens 2-79 and p. aureofaciens 30-84, which produce phenazine-1-carboxylic acid (pca), do not control this disease. to determine the role of the amide group in biocontrol, the pcn biosynthetic genes of strain pcl1391 were identified a ... | 2001 | 11497461 |
| effects of epiphytic enterobacteriaceae and pseudomonads on the growth of listeria monocytogenes in model media. | four enterobacteriaceae (enterobacter agglomerans and rhanella aquatilis) and six pseudomonads (pseudomonas fluorescens, pseudomonas chlororaphis, pseudomonas putida) isolated from minimally processed green endive were coinoculated at 10 degrees c with listeria monocytogenes in a minimal medium. pseudomonads did not modify the growth of l. monocytogenes, whereas enterobacteriaceae reduced its maximal population by 2 to 3 log cfu/ml. the same effect was observed in a diluted yeast extract medium ... | 2001 | 11348008 |
| tin-carbon cleavage of organotin compounds by pyoverdine from pseudomonas chlororaphis. | the triphenyltin (tpt)-degrading bacterium pseudomonas chlororaphis cnr15 produces extracellular yellow substances to degrade tpt. three substances (f-i, f-iia, and f-iib) were purified, and their structural and catalytic properties were characterized. the primary structure of f-i was established using two-dimensional nuclear magnetic resonance techniques; the structure was identical to that of suc-pyoverdine from p. chlororaphis atcc 9446, which is a peptide siderophore produced by fluorescent ... | 2003 | 12571007 |
| extracellular protease activity of different pseudomonas strains: dependence of proteolytic activity on culture conditions. | this study investigated the effect of growth conditions on proteolytic activity of a pseudomonas strain, named pseudomonas sp. lbsa1, isolated from bulk raw milk. it was compared with three pseudomonas chlororaphis and one pseudomonas fluorescens strain from culture collections. | 2005 | 16108806 |
| aldoxime dehydratase co-existing with nitrile hydratase and amidase in the iron-type nitrile hydratase-producer rhodococcus sp. n-771. | we identified an aldoxime dehydratase (oxd) gene in the 5'-flanking region of the nitrile hydratase-amidase gene cluster in the photoreactive iron-type nitrile hydratase-producer, rhodococcus sp. n-771. the enzyme showed 96.3%, 77.6%, and 30.4% identities with the oxds of rhodococcus globerulus a-4, pseudomonas chlororaphis b23, and bacillus sp. oxb-1, respectively. the enzyme was expressed in escherichia coli under the control of the lac- or t7 promoters in its intact and his6-tagged forms, pur ... | 2004 | 16233624 |
| the pyoverdine from pseudomonas chlororaphis d-tr133 showing mutual acceptance with the pyoverdine of pseudomonas fluorescens chao. | from pseudomonas chlororaphis d-tr 133 a pyoverdine was isolated and its primary structure were elucidated by spectroscopic methods and degradation reactions. despite some structural differences, its fe(iii) complex and that of the pyoverdine from pseudomonas fluorescens cha0 were taken up by either strain with a high rate. this is explained by a structural similarity between the two pyoverdines which were shown to differ in their structures only by the replacement of lys by ala in the c-termina ... | 2003 | 12572684 |
| expression of chlorocatechol 1,2-dioxygenase and chlorocatechol 2,3-dioxygenase genes in chlorobenzene-contaminated subsurface samples. | in order to evaluate the in situ degradative capabilities of microorganisms in an underground reactor facility housing two flowthrough columns filled with aquifer soil, we examined the distribution and phylogeny of gene transcripts encoding enzymes capable of catalyzing the cleavage of the chlorinated aromatic ring during transformation of the main pollutant, chlorobenzene. initial biostimulation of the autochthonous bacteria in the originally anaerobic reactor columns was achieved by injecting ... | 2003 | 12620818 |
| the competitiveness of pseudomonas chlororaphis carrying pjp4 is reduced in the arabidopsis thaliana rhizosphere. | the effect of the large catabolic incp plasmid pjp4 on the competitiveness of pseudomonas chlororaphis spr044 and on its derivatives spr244 (gacs deficient), spr344 (phenazine-1-carboxamide overproducer), and spr644 (phenazine-1-carboxamide deficient) in the arabidopsis thaliana rhizosphere was assessed. solitary rhizosphere colonization by the wild type, spr244, and spr644 was not affected by the plasmid. the size of the population of spr344 carrying pjp4, however, was significantly reduced com ... | 2003 | 12620876 |
| novel aldoxime dehydratase involved in carbon-nitrogen triple bond synthesis of pseudomonas chlororaphis b23. sequencing, gene expression, purification, and characterization. | analysis of the nitrile hydratase gene cluster involved in nitrile metabolism of pseudomonas chlororaphis b23 revealed that it contains one open reading frame encoding aldoxime dehydratase upstream of the amidase gene. the amino acid sequence deduced from this open reading frame shows similarity (32% identity) with that of bacillus phenylacetaldoxime dehydratase (kato, y., nakamura, k., sakiyama, h., mayhew, s. g., and asano, y. (2000) biochemistry 39, 800-809). the gene product expressed in esc ... | 2003 | 12773527 |
| optimisation of initial cell concentration enhances freeze-drying tolerance of pseudomonas chlororaphis. | the freeze-drying tolerance of pseudomonas chlororaphis, an antifungal bacterium used as biocontrol agent was investigated. p. chlororaphis is freeze-drying sensitive and the viability drops more than 3 log units in the absence of protective freeze-drying medium. of the freeze-drying media tested, lactose, sucrose, trehalose, glutamate, sucrose with glutamate, skimmed milk, and skimmed milk with trehalose, skimmed milk gave the lowest survival (0.6+/-0.2%) and sucrose the highest (6.4+/-1.2%). c ... | 2003 | 12963409 |
| total synthesis of the depsipeptide fr-901375. | the first total synthesis of fr-901375, a novel bicyclic depsipeptide isolated from the fermentation broth of pseudomonas chloroaphis no. 2522, has been achieved. the synthetic approach involves 13 reaction steps and is achieved in 12% overall yield. the key points in the successful synthetic strategy are a concise asymmetric synthesis of the key building block (3r,4e)-3-hydroxy-7-mercapto-4-heptenoic acid, a mild mitsunobu macrolactonization step, and an i(2)-mediated deprotection with concomit ... | 2003 | 14604360 |
| transcriptional regulation and mutational analysis of a dcta gene encoding an organic acid transporter protein from pseudomonas chlororaphis o6. | a dcta gene encoding a protein with identity to a c(4)-dicarboxylic acid/h(+) symporter was cloned from a beneficial root colonizer, pseudomonas chlororaphis o6 (pco6). expression of the dcta gene was induced in minimal medium by several organic acids and was repressed by glucose. highest expression was observed in early-logarithmic (log) cells grown on fumarate, acetate or succinate with decline as cells approached late-log growth phase. the dcta transcript accumulated weakly when cells were gr ... | 2003 | 14659885 |
| [the production of antifungal metabolites by pseudomonas chlororaphis grown on different nutrient sources]. | it was found that the antifungal activity of pseudomonas chlororaphis spb1217 is due to phenazine-1-carboxylic acid, phenazine-1-carboxamide, and two unidentified exometabolites. the carbon source used for the growth of this bacterial strain and iron ions present in the medium considerably influenced the proportion between the antifungal metabolites. the maximum production of phenazines was observed in the media enriched in amino acids and iron ions. the absence of correlation between the produc ... | 2003 | 14679903 |
| the global regulator gacs of a biocontrol bacterium pseudomonas chlororaphis o6 regulates transcription from the rpos gene encoding a stationary-phase sigma factor and affects survival in oxidative stress. | the global regulator, gacs (global activator for antibiotics and cyanide sensor kinase), of the rhizosphere bacterium pseudomonas chlororaphis o6 (pc o6) was required for increased resistance to hydrogen peroxide as cultures mature. specific bands of peroxidase and catalase activity were absent in the stationary-phase cells of the pc o6 gacs mutant, whereas a manganese superoxide dismutase (mnsod) isozyme was expressed earlier and to a greater extent than in the wild-type. in the wild-type cell, ... | 2004 | 14697518 |
| two azurins with unusual redox and spectroscopic properties isolated from the pseudomonas chlororaphis strains dsm 50083t and dsm 50135. | two azurins (az624 and az626) were isolated from the soluble extract of two strains of pseudomonas chlororaphis, dsm 50083(t) and dsm 50135, respectively, grown under microaerobic conditions with nitrate as final electron acceptor. the azurins, purified to electrophoretic homogeneity in three chromatographic steps, exhibit several peculiar properties. they have high reduction potentials and lower pi than most azurins described in the literature. as previously observed for pseudomonas aeruginosa ... | 2004 | 14729308 |
| using dual-bacterial denitrification to improve delta15n determinations of nitrates containing mass-independent 17o. | the bacterial denitrification method for isotopic analysis of nitrate using n(2)o generated from pseudomonas aureofaciens may overestimate delta(15)n values by as much as 1-2 per thousand for samples containing atmospheric nitrate because of mass-independent (17)o variations in such samples. by analyzing such samples for delta(15)n and delta(18)o using the denitrifier pseudomonas chlororaphis, one obtains nearly correct delta(15)n values because oxygen in n(2)o generated by p. chlororaphis is pr ... | 2004 | 14755607 |
| gene expression analysis in cucumber leaves primed by root colonization with pseudomonas chlororaphis o6 upon challenge-inoculation with corynespora cassiicola. | root colonization by pseudomonas chlororaphis o6, a non-pathogenic rhizobacterium, induced systemic resistance in cucumber against target leaf spot caused by corynespora cassiicola. a cdna library was constructed using mrna extracted from cucumber leaves 12 h after inoculation with c. cassiicola, using plants colonized by o6. to identify genes involved in o6-mediated induced systemic resistance (isr), we employed a subtractive hybridization method using mrnas extracted from pathogen-challenged c ... | 2004 | 15045660 |
| influence of environmental conditions on the production of phenazine-1-carboxamide by pseudomonas chlororaphis pcl1391. | pseudomonas chlororaphis pcl1391 produces the secondary metabolite phenazine-1-carboxamide (pcn), which is an antifungal metabolite required for biocontrol activity of the strain. identification of conditions involved in pcn production showed that some carbon sources and all amino acids tested promote pcn levels. decreasing the ph from 7 to 6 or decreasing the growth temperature from 21 to 16 degrees c decreased pcn production dramatically. in contrast, growth at 1% oxygen as well as low magnesi ... | 2004 | 15141960 |
| copper-containing nitrite reductase from pseudomonas chlororaphis dsm 50135. | the nitrite reductase (nir) isolated from pseudomonas chlororaphis dsm 50135 is a blue enzyme, with type 1 and type 2 copper centers, as in all copper-containing nirs described so far. for the first time, a direct determination of the reduction potentials of both copper centers in a cu-nir was performed: type 2 copper (t2cu), 172 mv and type 1 copper (t1cu), 298 mv at ph 7.6. although the obtained values seem to be inconsistent with the established electron-transfer mechanism, epr data indicate ... | 2004 | 15182351 |
| the pseudomonas chlororaphis pcl1391 sigma regulator psra represses the production of the antifungal metabolite phenazine-1-carboxamide. | the rhizobacterium pseudomonas chlororaphis pcl1391 produces the antifungal metabolite phenazine-1-carboxamide (pcn), which is a crucial trait in its competition with the phytopathogenic fungus fusarium oxysporum f. sp. radicis-lycopersici in the rhizosphere. the expression of the pcn biosynthetic gene cluster in pcl1391 is population density-dependent and is regulated by the quorum-sensing genes phzi and phzr via synthesis of the autoinducer n-hexanoyl-l-homoserine lactone (c6-hsl). here, we de ... | 2005 | 15782638 |
| isolation and spectroscopic characterization of the membrane-bound nitrate reductase from pseudomonas chlororaphis dsm 50135. | a nitrate reductase was solubilized with triton x-100 from the membranes of pseudomonas chlororaphis dsm 50135 grown microaerobically in the presence of nitrate. like other membrane-bound nitrate reductases, it contains three subunits, of 129, 66 (64) and 24 kda, referred to in the literature as alpha, beta and gamma, respectively. electrocatalytic studies revealed that only the membrane-bound, not the solubilized form of the enzyme, can accept electrons from a menaquinone analog, menadione, whe ... | 2005 | 15804488 |
| [trigliceropeptides from pseudomonades: new agents for biological control of phytopathogenic fungi]. | substances of peptide nature have been isolated from low-molecular-weight fraction of extracellular metabolites of pseudomonas chlororaphis (strains ib 51 and ib 6) and pseudomonas putida (strain ib 17). these substances possess antifungal activity against a broad range of phytopathogens but lack the properties of siderophores. it has been shown by hplc, ir, and 13c nmr spectroscopy that isolated metabolites are glycerol tripeptides with molecular weights in the range 2.8-3.0 kda. | 2005 | 15810738 |
| production of rhamnolipids by pseudomonas chlororaphis, a nonpathogenic bacterium. | rhamnolipids, naturally occurring biosurfactants constructed of rhamnose sugar molecules and beta-hydroxyalkanoic acids, have a wide range of potential commercial applications. in the course of a survey of 33 different bacterial isolates, we have identified, using a phenotypic assay for rhamnolipid production, a strain of the nonpathogenic bacterial species pseudomonas chlororaphis that is capable of producing rhamnolipids. rhamnolipid production by p. chlororaphis was achieved by growth at room ... | 2005 | 15870313 |
| uranium uptake by some locally isolated and some reference bacterial species. | in the present study, uranium absorption capacity of bacillus pantothenticus and bacillus megaterium, previously isolated from the environmental air surrounding the 60co gamma source, is reported. pseudomonas putida and pseudomonas chlororaphis were used as reference species. concerning uranium uptake, the local species were more efficient than the reference ones. the maximum uptake of uranium was achieved by b. megaterium and p. chlororaphis at 20 microg u ml(-1) and by b. pantothenticus at 30 ... | 2005 | 15907227 |
| exposure to airborne microorganisms, dust and endotoxin during processing of valerian roots on farms. | the aim of this study was to determine the levels of microorganisms, dust and endotoxin in the air during various stages of valerian (valeriana officinalis) roots processing by herb farmers and to examine the species composition of airborne microflora. air samples were collected on glass fibre filters by use of personal samplers on 15 farms owned by valerian cultivating farmers, located in lublin province (eastern poland). the concentrations of total viable microorganisms (bacteria + fungi) in t ... | 2005 | 16028876 |
| influence of fusaric acid on phenazine-1-carboxamide synthesis and gene expression of pseudomonas chlororaphis strain pcl1391. | production of the antifungal metabolite phenazine-1-carboxamide (pcn) by pseudomonas chlororaphis strain pcl1391 is essential for the suppression of tomato foot and root rot caused by the soil-borne fungus f. oxysporum f. sp. radicis-lycopersici. the authors have shown previously that fusaric acid (fa), a phytotoxin produced by fusarium oxysporum, represses the production of pcn and of the quorum-sensing signal n-hexanoyl-l-homoserine lactone (c(6)-hsl). here they report that pcn repression by f ... | 2005 | 16079356 |
| selection of bacteria able to control fusarium oxysporum f. sp. radicis-lycopersici in stonewool substrate. | tomato foot and root rot (tfrr), caused by fusariumoxysporum f. sp. radicis-lycopersici (forl), is an economically important disease of tomato. the aim of this study was to develop an efficient protocol for the isolation of bacteria, which controls tfrr based on selection of enhanced competitive root-colonizing bacteria from total rhizosphere soil samples. | 2007 | 17241352 |
| [effect of naphthalene biodegradation plasmids on physiological characteristics of rhizospheric bacteria of the genus pseudomonas]. | specific growth rate, duration of the lag phase, stability of plasmids, and activities of the key enzymes involved in naphthalene biodegradation were studied in rhizospheric pseudomonades carrying structurally similar plasmids pov17 and pbs216. it was demonstrated that these plasmids determined various levels of catechol 2,3-dioxygenase activities. the structural rearrangements in the plasmid pbs216 could "switch off" the genes of catechol oxidation meta-pathway. it was shown that certain combin ... | 2005 | 16240650 |
| characterization of a phenazine-producing strain pseudomonas chlororaphis gp72 with broad-spectrum antifungal activity from green pepper rhizosphere. | a new pseudomonas strain, designated gp72, was isolated from green pepper rhizosphere and identified as a member of species pseudomonas chlororaphis based on morphology; conventional biochemical and physiologic tests; biolog gn system (biolog inc., hayward, ca); and 16s rdna sequence analysis. the secondary metabolites produced by this strain have shown broad-spectrum antifungal activity against various phytopathogens of agricultural importance in vitro. two main antifungal substances produced b ... | 2007 | 17334842 |
| regulatory roles of psra and rpos in phenazine-1-carboxamide synthesis by pseudomonas chlororaphis pcl1391. | production of the secondary metabolite phenazine-1-carboxamide (pcn) by pseudomonas chlororaphis pcl1391 is crucial for biocontrol activity against the phytopathogen fusarium oxysporum f. sp. radicis lycopersici on tomato. regulation of pcn production involves the two-component signalling system gacs/gaca, the quorum-sensing system phzi/phzr and the regulator psra. this paper reports that a functional rpos is required for optimal pcn and n-hexanoyl-l-homoserine lactone (c(6)-hsl) production. con ... | 2006 | 16385114 |
| distinguishing nitrous oxide production from nitrification and denitrification on the basis of isotopomer abundances. | the intramolecular distribution of nitrogen isotopes in n2o is an emerging tool for defining the relative importance of microbial sources of this greenhouse gas. the application of intramolecular isotopic distributions to evaluate the origins of n2o, however, requires a foundation in laboratory experiments in which individual production pathways can be isolated. here we evaluate the site preferences of n2o produced during hydroxylamine oxidation by ammonia oxidizers and by a methanotroph, ammoni ... | 2006 | 16391101 |
| discovery of a reaction intermediate of aliphatic aldoxime dehydratase involving heme as an active center. | recently, we discovered an intriguing hemoprotein [aliphatic aldoxime dehydratase (oxda)] that catalyzes the dehydration of aliphatic aldoximes [r-ch=n-oh] to the corresponding nitriles [r-c identical withn] in the industrial pseudomonas chlororaphis b23 strain. unlike the utilization of h(2)o(2) or o(2) as a mediator of the catalysis by other heme-containing enzymes (e.g., p450), oxda is notable for the direct binding of a substrate to the heme iron, experimental evidence of which was obtained ... | 2006 | 16407114 |
| the dcta gene of pseudomonas chlororaphis o6 is under rpon control and is required for effective root colonization and induction of systemic resistance. | transcription from the dcta gene, which encodes an organic acid transporter in the root-colonizing bacterium pseudomonas chlororaphis o6, is under complex regulatory control. promoter sequence analysis revealed an rpon binding site. the regulation of transcript accumulation by the level of ammonium ions in the growth medium confirmed rpon regulation, even in the presence of glucose. a dcta mutant colonized tobacco roots to a lesser extent than the wild-type mutant during early seedling developme ... | 2006 | 16487325 |
| purification and characterization of an enantioselective amidase from pseudomonas chlororaphis b23. | an amidase produced by pseudomonas chlororaphis b23 was purified and characterized. the purification procedure used included ammonium sulfate precipitation and hydrophobic, anion-exchange, gel filtration, and ceramic hydroxyapatite chromatography steps. this amidase has a native molecular mass of about 105 kda and is a homodimer whose subunits have a molecular mass of 54 kda. the enzyme exhibited maximal activity at 50(deg)c and at ph values ranging from 7.0 to 8.6. we found no evidence that met ... | 1995 | 16534982 |
| [effect of catabolic plasmids on physiological parameters and efficiency of oil destruction by bacteria of the genus pseudomonas]. | the ability of microbial degraders of polycyclic aromatic hydrocarbons to grow at 24 degrees c in liquid mineral medium supplemented with oil as the sole source of carbon and energy was studied. growth characteristics (cfu) and the level of oil destruction by plasmid-bearing and plasmid-free strains were determined after seven days of cultivation. the presence of catabolic plasmids in the degrader strains, including rhizosphere pseudomonads, was shown to increase cell growth and enhance the leve ... | 2007 | 17633410 |
| variation in sensitivity of gaeumannomyces graminis to antibiotics produced by fluorescent pseudomonas spp. and effect on biological control of take-all of wheat. | isolates of gaeumannomyces graminis var. tritici, the causal agent of take-all of wheat, varied in sensitivity in vitro to the antibiotics phenazine-1-carboxylic acid (pca) and 2,4-diacetylphloroglucinol (phl) produced by fluorescent pseudomonas spp. shown previously to have potential for biological control of this pathogen. none of the four isolates of g. graminis var. avenae examined were sensitive to either of the antibiotics in vitro at the concentrations tested. the single isolate of g. gra ... | 1995 | 16535070 |
| biocontrol of avocado dematophora root rot by antagonistic pseudomonas fluorescens pcl1606 correlates with the production of 2-hexyl 5-propyl resorcinol. | a collection of 905 bacterial isolates from the rhizospheres of healthy avocado trees was obtained and screened for antagonistic activity against dematophora necatrix, the cause of avocado dematophora root rot (also called white root rot). a set of eight strains was selected on the basis of growth inhibitory activity against d. necatrix and several other important soilborne phytopathogenic fungi. after typing of these strains, they were classified as belonging to pseudomonas chlororaphis, pseudo ... | 2006 | 16610745 |
| effect of insertional mutations in the puea and pueb genes encoding two polyurethanases in pseudomonas chlororaphis contained within a gene cluster. | to better understand the role of puea and pueb from pseudomonas chlororaphis in polyurethane degradation, the present study was conducted to create insertional mutants in their respective genes. | 2007 | 18045391 |
| detection of antibiotic-related genes from bacterial biocontrol agents with polymerase chain reaction. | pseudomonas chlororaphis pa23, pseudomonas spp. strain df41, and bacillus amyloliquefaciens bs6 consistently inhibit infection of canola petals by sclerotinia sclerotiorum in both greenhouse and field experiments. bacillus thuringiensis bs8, bacillus cereus l, and bacillus mycoides s have shown significant inhibition against s. sclerotiorum on plate assays. the presence of antibiotic biosynthetic or self-resistance genes in these strains was investigated with polymerase chain reaction and, in on ... | 2006 | 16699573 |
| production of indole-3-acetic acid in the plant-beneficial strain pseudomonas chlororaphis o6 is negatively regulated by the global sensor kinase gacs. | certain plant growth-promoting bacteria, such as pseudomonas fluorescens 89b61 and bacillus pumilus se34, secreted high levels of indole-3-acetic acid (iaa) in tryptophan-amended medium in stationary phase as determined by chromogenic analysis and high-performance liquid chromatography. two other growth-promoting strains, p. chlororaphis o6 and serratia marcescens 90-166, did not produce these high levels of iaa. however, when the gacs mutant of p. chlororaphis o6 was grown in tryptophan-supplem ... | 2006 | 16732458 |
| the fate of a genetically modified pseudomonas strain and its transgene during the composting of poultry manure. | the fate of the genetically modified (gm) pseudomonas chlororaphis strain 3732 rn-l11 and its transgene (lacz insert) during composting of chicken manure was studied using plate count and nested polymerase chain reaction (pcr) methods. the detection sensitivity of the nested pcr method was 165 copies of the modified gene per gram of moist compost or soil. compost microcosms consisted of a 100-g mixture of chicken manure and peat, whereas soil microcosms were 100-g samples of sandy clay loam. eac ... | 2004 | 15284887 |
| identification of bacteria from the normal flora of perch, perca fluviatilis l., and evaluation of their inhibitory potential towards aeromonas species. | pathogenic aeromonas sobria has been identified as a causative agent of ulcerative disease in farmed european perch, perca fluviatilis l. to study the effect of the normal intestinal bacterial flora of perch against a. sobria, we sampled 193 bacterial isolates from the perch digestive tract. the isolates were identified by sequence analysis of the 16s rrna gene and their inhibitory potential against a. sobria was evaluated in vitro. nineteen of the strains isolated showed inhibition and were als ... | 2008 | 18355180 |
| nitrile pathway involving acyl-coa synthetase: overall metabolic gene organization and purification and characterization of the enzyme. | two open reading frames (nhps and acsa) were identified immediately downstream of the previously described pseudomonas chlororaphis b23 nitrile hydratase (nhase) gene cluster (encoding aldoxime dehydratase, amidase, the two nhase subunits, and an uncharacterized protein). the amino acid sequence deduced from acsa shows similarity to that of acyl-coa synthetase (acsa). the acsa gene product expressed in escherichia coli showed acyl-coa synthetase activity toward butyric acid and coa as substrates ... | 2005 | 15632196 |
| degradation of acyl-homoserine lactone molecules by acinetobacter sp. strain c1010. | a bacterium c1010, isolated from the rhizospheres of cucumbers in fields in korea, degraded the microbial quorum-sensing molecules, hexanoyl homoserine lactone (hhsl), and octadecanoyl homoserine lactone (ohsl). morphological characteristics and 16s rrna sequence analysis identified c1010 as acinetobacter sp. strain c1010. this strain was able to degrade the acyl-homoserine lactones (ahls) produced by the biocontrol bacterium, pseudomonas chlororaphis o6, and a phytopathogenic bacterium, burkhol ... | 2004 | 15644910 |
| proteomic based investigation of rhamnolipid production by pseudomonas chlororaphis strain nrrl b-30761. | we recently reported that a strain of the non-pathogenic bacterial species pseudomonas chlororaphis was capable of producing the biosurfactant molecule, rhamnolipids. previous to this report the organisms known to produce rhamnolipids were almost exclusively pathogens. the newly described p. chlororaphis strain produced rhamnolipids at room temperature in static minimal media, as opposed to previous reports of rhamnolipid production which occurred at elevated temperatures with mechanical agitati ... | 2006 | 16964509 |
| pip, a novel activator of phenazine biosynthesis in pseudomonas chlororaphis pcl1391. | secondary metabolites are important factors for interactions between bacteria and other organisms. pseudomonas chlororaphis pcl1391 produces the antifungal secondary metabolite phenazine-1-carboxamide (pcn) that inhibits growth of fusarium oxysporum f. sp. radius lycopersici the causative agent of tomato foot and root rot. our previous work unraveled a cascade of genes regulating the pcn biosynthesis operon, phzabcdefgh. via a genetic screen, we identify in this study a novel tetr/acrr regulator ... | 2006 | 16997957 |
| [quorum-sensing regulation in soil pseudomonads]. | 228 strains of soil and rhizosphere pseudomonads isolated in different geographic zones were screened, with the use of two tester systems, for the capacity to produce n-acetyl-homoserine lactones (ahls), which are autoinducers involved in quorum-sensing (qs) regulation. ahl production was found in 11.4% of the strains investigated. in five pseudomonas chlororaphis strains shown to be active ahl producers and chosen for further study, pcr identified two qs systems that involved the phzi, phzr, cs ... | 2006 | 17025170 |
| [isolation and characterization of a new pseudomonas strain against phytophthora capsici]. | one pseudomonas strain gp72, which was against phytophthora capsici, was isolated from green pepper rhizosphere in jiangsu province. it had distinctively inhibitive effect on several kinds of pathogenic fungi; mostly of them are soilborne pathogens. therefore, this strain may be used for an effective biocontrol strain in the crop protection. the morphological, biochemical and physiological characteristics, biolog gn, g + c mol% content and 16s rdna sequence analysis of this strain were studied. ... | 2006 | 17037046 |
| galactinol is a signaling component of the induced systemic resistance caused by pseudomonas chlororaphis o6 root colonization. | root colonization by pseudomonas chlororaphis o6 in cucumber elicited an induced systemic resistance (isr) against corynespora cassiicola. in order to gain insight into o6-mediated isr, a suppressive subtractive hybridization technique was applied and resulted in the isolation of a cucumber galactinol synthase (csgols1) gene. the transcriptional level of csgols1 and the resultant galactinol content showed an increase several hours earlier under o6 treatment than in the water control plants follo ... | 2008 | 18986260 |
| [quorum sensing systems of regulation, synthesis of phenazine antibiotics, and antifungal (corrected) activity in rhizospheric bacterium pseudomonas chlororaphis 449]. | strain pseudomonas chlororaphis 449, an antagonist of a broad spectrum of phytopathogenic microorganisms isolated from the maize rhizosphere, was shown to produce three phenazine antibiotics: phenazine-1-carboxylic acid (pca), 2-hydroxylphenazine-1-carboxylic acid (2-oh-pca), and 2-hydroxylphenazine (2-oh-phz). two quorum sensing (qs) systems of regulation were identified: phzir and csai/r. genes phzi and csai were cloned and sequenced. cells of strain 449 synthesize at least three types of ahl: ... | 2008 | 19178080 |
| rhizobium etli usda9032 engineered to produce a phenazine antibiotic inhibits the growth of fungal pathogens but is impaired in symbiotic performance. | phenazine production was engineered in rhizobium etli usda9032 by the introduction of the phz locus of pseudomonas chlororaphis o6. phenazine-producing r. etli was able to inhibit the growth of botrytis cinerea and fusarium oxysporum in vitro. black bean inoculated with phenazine-producing r. etli produced brownish fix(-) nodules. | 2007 | 17085692 |
| mutation in the edd gene encoding the 6-phosphogluconate dehydratase of pseudomonas chlororaphis o6 impairs root colonization and is correlated with reduced induction of systemic resistance. | the primary objective of this study was to determine the role of 6-phosphogluconate dehydratase in root colonization and the induction of systemic resistance by the rhizobacterium, pseudomonas chlororaphis o6. | 2007 | 17209815 |
| transcript accumulation from the rpos gene encoding a stationary-phase sigma factor in pseudomonas chlororaphis strain o6 is regulated by the polyphosphate kinase gene. | polyphosphate levels are modulated by the actions of polyphosphate kinase, encoded by ppk, and exopolyphosphatase, encoded by ppx. the genes ppk and ppx are adjacent to each other in the genome of the root colonizer, pseudomonas chlororaphis o6. a ppk-deficient mutant was more sensitive to oxidative stress than the wild-type and the ppx mutant. transcripts from ppx increased as cultures matured from mid- to late-logarithmic and stationary phases, whereas abundance was greater for ppk in the late ... | 2007 | 17294328 |
| a gacs deficiency does not affect pseudomonas chlororaphis pa23 fitness when growing on canola, in aged batch culture or as a biofilm. | pseudomonas chlororaphis pa23 is a biocontrol agent that protects against the fungal pathogen sclerotinia sclerotiorum. employing transposon mutagenesis, we isolated a gacs mutant that no longer exhibited antifungal activity. pseudomonas chlororaphis pa23 was previously reported to produce the nonvolatile antibiotics phenazine 1-carboxylic acid and 2-hydroxyphenazine. we report here that pa23 produces additional compounds, including protease, lipase, hydrogen cyanide, and siderophores, that may ... | 2006 | 17473887 |
| isolation and identification of a novel strain of pseudomonas chlororaphis capable of transforming isoeugenol to vanillin. | vanillin is undoubtedly one of the most popular and widely used flavoring agents in the world. taking into consideration the worldwide demand for natural vanillin and its limited supply, alternative routes for its production including biotransformation are being constantly explored. in this regard, a novel soil bacterium capable of converting isoeugenol to vanillin was isolated by conventional enrichment process from soils of ocimum field. on the basis of morphological and physiochemical charact ... | 2007 | 17487530 |
| collimonas fungivorans, an unpredicted in vitro but efficient in vivo biocontrol agent for the suppression of tomato foot and root rot. | although bacteria from the genus collimonas have demonstrated in vitro antifungal activity against many different fungi, they appeared inactive against the plant-pathogenic fungus fusarium oxysporum f.sp. radicis-lycopersici (forl), the causal agent of tomato foot and root rot (tfrr). visualization studies using fluorescently labelled organisms showed that bacterial cells attached extensively to the fungal hyphae under nutrient-poor conditions but not in glucose-rich armstrong medium. collimonas ... | 2007 | 17504497 |
| pseudomonas chlororaphis strain jf3835 reduces mortality of juvenile perch, perca fluviatilis l., caused by aeromonas sobria. | motile aeromonad septicaemia caused by aeromonas sobria is a cause of disease in farmed perch, perca fluviatilis l., in switzerland. we have evaluated the potential of a pseudomonas chlororaphis isolate, obtained from perch intestine, to control a. sobria infection. inoculation of juvenile perch with p. chlororaphis strain jf3835 prior to infection with a. sobria caused a reduction in a. sobria associated mortalities. infection of perch with xyle-labelled p. chlororaphis indicated the bacterium ... | 2009 | 19476558 |
| reclassification of pseudomonas aurantiaca as a synonym of pseudomonas chlororaphis and proposal of three subspecies, p. chlororaphis subsp. chlororaphis subsp. nov., p. chlororaphis subsp. aureofaciens subsp. nov., comb. nov. and p. chlororaphis subsp. aurantiaca subsp. nov., comb. nov. | pseudomonas chlororaphis, pseudomonas aureofaciens and pseudomonas aurantiaca were considered as separate species until 1989, when p. aureofaciens was proposed as a later heterotypic synonym of p. chlororaphis with p. aurantiaca remaining as a separate species. nevertheless, analysis of the almost complete 16s rrna gene sequences revealed that the type strain of p. aurantiaca, ncimb 10068(t), shows gene sequence similarities close to 99.5 % with respect to p. chlororaphis dsm 50083(t) and p. aur ... | 2007 | 17551044 |
| [rhizosphere strain of pseudomonas chlororaphis capable of degrading naphthalene in the presence of cobalt/nickel]. | combination of genetic systems of degradation of polyaromatic hydrocarbons, resistance to heavy metals, and promotion of plant growth/protection is one of the approaches to the creation of polyfunctional strains for phytoremediation of soils after combined contamination with organic pollutants and heavy metals. a plant-growth-promoting rhizosphere strain pseudomonas chlororaphis pcl1391 (pbs216*, pbs501) has been obtained, in which the nah operon of plasmid pbs216 provides naphthalene biodegrada ... | 2007 | 17583218 |
| quorum sensing inhibition activity of garlic extract and p-coumaric acid. | the goal of this work was to investigate the influence of dmso, garlic extract and p-coumaric acid on bacterial quorum sensing (qs). | 2009 | 19709367 |
| degradation of pathogen quorum-sensing molecules by soil bacteria: a preventive and curative biological control mechanism. | abstract the plasmid pme6863, carrying the aiia gene from the soil bacterium bacillus sp. a24 that encodes a lactonase enzyme able to degrade n-acyl-homoserine lactones (ahls), was introduced into the rhizosphere isolate pseudomonas fluorescens p3. this strain is not an effective biological control agent against plant pathogens. the transformant p. fluorescens p3/pme6863 acquired the ability to degrade ahls. in planta, p. fluorescens p3/pme6863 significantly reduced potato soft rot caused by erw ... | 2003 | 19719608 |
| freeze-thaw tolerance and clues to the winter survival of a soil community. | although efforts have been made to sample microorganisms from polar regions and to investigate a few of the properties that facilitate survival at freezing or subzero temperatures, soil communities that overwinter in areas exposed to alternate freezing and thawing caused by foehn or chinook winds have been largely overlooked. we designed and constructed a cryocycler to automatically subject soil cultures to alternating freeze-thaw cycles. after 48 freeze-thaw cycles, control escherichia coli and ... | 2006 | 16517623 |
| n-(3-hydroxyhexanoyl)-l-homoserine lactone is the biologically relevant quormone that regulates the phz operon of pseudomonas chlororaphis strain 30-84. | phenazine production by pseudomonas fluorescens 2-79 and p. chlororaphis isolates 30-84 and pcl1391 is regulated by quorum sensing through the activator phzr and acyl-homoserine lactones (acyl-hsls) synthesized by phzi. phzi from p. fluorescens 2-79 produces five acyl-hsls that include four 3-hydroxy species. of these, n-(3-hydroxyhexanoyl)-hsl is the biologically relevant ligand for phzr. the quorum-sensing systems of p. chlororaphis strains 30-84 and pcl1391 have been reported to produce and r ... | 2007 | 17921283 |
| [suggested interrelationships of rna-polymerase sigma s subunit and nitrogen control system in pseudomonas chlororaphis]. | the effect of mutation in rpos gene encoding sigma s subunit of rna-polymerase on the capacity of pseudomonas chlororaphis 449 to assimilate nitrogen was investigated. it has been shown that mutant cells with knocked-out rpos gene had significantly lower capacity to utilize the nitrogen sources such as alanine, proline, histidine, arginine, urea, and ammonium and glutamine synthetase was downregulated in their cell free extracts. both defects were abolished by glutamine supplementation to the me ... | 2007 | 17958300 |
| inhibition of seed germination and induction of systemic disease resistance by pseudomonas chlororaphis o6 requires phenazine production regulated by the global regulator, gacs. | seed coating by a phenazine-producing bacterium, pseudomonas chlororaphis o6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. in wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. deletion of the gacs gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzi gene and the biosynthetic phza gene. the inhibiti ... | 2007 | 18051268 |
| characterization of a homogentisate dioxygenase mutant in pseudomonas chlororaphis o6. | transposon mutagenesis of pseudomonas chlororaphis o6 was performed with the transposon tn5 to investigate genes involved in production of secondary metabolites. a mutant, termed org, produced intense dark-brown pigmentation on rich medium. the tn5-flanking sequence of the org mutant showed high homology with the hmga gene encoding the enzyme homogentisate dioxygenase, involved in the degradation of aromatic amino acids such as tyrosine. growth of the hmga mutant on l-tyrosine as sole carbon and ... | 2008 | 18074175 |