chromobacteriosis in a chinese red panda (ailurus fulgens styani).an adult chinese red panda (ailurus fulgens styani) transported by airplane from florida to a north dakota zoo died 1 week after arrival. grossly, an interscapular abscess, subcutaneous inflammation, lymphadenitis, and pulmonary abscesses were observed. microscopic findings included necrotizing inflammation in liver, lung, lymph node, and spleen. chromobacterium violaceum was cultured from the interscapular abscess, liver, lung, and spleen and was injected into swiss webster mice. these mice die ...200010730953
extraction of violacein from chromobacterium violaceum provides a new quantitative bioassay for n-acyl homoserine lactone autoinducers.fatty acyl homoserine lactones (ahls) are used as extracellular quorum sensing signals by a variety of gram-negative bacteria. by activating proteins belonging to the luxr family of transcriptional regulators, these signal metabolites allow population density-dependent gene regulation within a species, as well as interspecies communication among different bacteria. the experimental detection of ahls is important in the identification of quorum sensing capabilities in bacteria. chromobacterium vi ...200010739342
crystal structure of a bacterial lipase from chromobacterium viscosum atcc 6918 refined at 1.6 angstroms resolution.the crystal structure of a lipase from the bacterium chromobacterium viscosum atcc 6918 (cvl) has been determined by isomorphous replacement and refined at 1.6 angstroms resolution to an r-factor of 17.8%. the lipase has the overall topology of an alpha/beta type protein, which was also found for previously determined lipase structures. the catalytic triad of the active center consists of the residues ser87, asp263 and his285. these residues are not exposed to the solvent, but a narrow channel c ...19968683577
acute pleuropneumonia in barbary sheep (amnotragus lervia) associated with chromobacterium violaceum. 19968736506
sq 26,180, a novel monobactam. i taxonomy, fermentation and biological properties.strains of chromobacterium violaceum, isolated from various environments, were found to produce a novel monocyclic beta-lactam antibiotic. the antibiotic, sq 26,180 was weakly active against gram-positive and gram-negative bacteria with the exception of mutants hypersensitive to beta-lactam antibiotics. the compound was highly stable to beta-lactamases and acted as an inhibitor of the p99 enzyme from enterobacter cloacae. sq 26,180 showed affinity for penicillin-binding proteins 1a, 4 and 5/6 of ...19826978877
inhibition of microbial lipases with stereoisomeric triradylglycerol analog phosphonates.1,2(2,3)-diradylglycero o-(p-nitrophenyl) n-hexylphosphonates were synthesized, with the diradylglycerol moiety being di-o-octylglycerol, 1-o-hexadecyl-2-o-pyrenedecanylglycerol, or 1-o-octyl-2-oleoyl-glycerol, and tested for their ability to inactivate lipases from chromobacterium viscosum (cvl) and rhizopus oryzae (rol). the experimental data indicate the formation of stable, covalent 1:1 enzyme-inhibitor adducts with the di-o-alkylglycero phosphonates. the differences in reactivity of diaster ...19968982269
chromobacterium violaceum diarrhea.this is the first case of chromobacterium violaceum diarrhoea from coastal karnataka reported in a 2 year 10 months old girl. stool culture yielded chromobacterium violaceum and was sensitive to ampicillin, gentamicin, chloramphenicol, erythromycin and septran. patient completely recovered with ampicillin and gentamicin.200010885215
diversity of culturable heterotrophic aerobic bacteria in pristine stream bed sediments.more than 900 culturable, heterotrophic aerobic isolates were obtained from the sediments of a forested, pristine stream and analyzed using three classical microbiological tests: api 20e, amplified ribosomal dna restriction analysis (ardra), and fatty acid analysis. gram-negative bacteria comprised most of the heterotrophic aerobic isolates (66.7%), similar to other oligotrophic environments. the isolates were assigned to the genus level as pseudomonas, flavobacterium, micrococcus, bacillus, chr ...199910907425
skin infections and infestations in aboriginal communities in northern australia.the most important skin infections in aboriginal communities in central and northern australia are scabies and streptococcal pyoderma. scabies is endemic in many remote aboriginal communities, with prevalences in children up to 50%. the cycles of scabies transmission underlie much of the pyoderma. up to 70% of children have skin sores, with group a streptococcus (gas) the major pathogen. group a streptococcus is responsible for the continuing outbreaks of post-streptococcal glomerulonephritis an ...200010954983
fatal and non-fatal chromobacterial septicemia: report of two cases.chromobacterium violaceum is frequently found in soil and water in tropical and subtropical regions. the organism rarely causes infection in humans, but is associated with a high mortality rate when it occurs. septicemia associated with abscess in multiple organs such as the liver, skin, lungs, spleen, lymph nodes, and brain has been reported. we report on 2 patients with systemic infections with chromobacterium violaceum. one presented with a fulminant course with multiple organ involvement and ...200011039252
sequence analysis and functional characterization of the violacein biosynthetic pathway from chromobacterium violaceum.violacein is a purple-colored, broad-spectrum antibacterial pigment that has a dimeric structure composed of 5-hydroxyindole, oxindole and 2-pyyrolidone subunits formed by the condensation of two modified tryptophan molecules. the violacein biosynthetic gene cluster from chromobacterium violaceum was characterized by dna sequencing, transposon mutagenesis, and chemical analysis of the pathway intermediates produced heterologously in escherichia. coli. the violacein biosynthetic gene cluster span ...200011075927
quorum sensing in vibrio anguillarum: characterization of the vani/vanr locus and identification of the autoinducer n-(3-oxodecanoyl)-l-homoserine lactone.certain gram-negative pathogens are known to control virulence gene expression through cell-cell communication via small diffusible signal molecules termed autoinducers. this intercellular signal transduction mechanism termed quorum sensing depends on the interaction of an n-acylhomoserine lactone (ahl) auto-inducer molecule with a receptor protein belonging to the luxr family of positive transcriptional activators. vibrio anguillarum is a gram-negative pathogen capable of causing a terminal hem ...19979139920
development of small-size tubular-flow continuous reactors for the analysis of operational stability of enzymes in low-water systems.a very small-scale continuous flow reactor has been designed for use with enzymes in organic media, particularly for operational stability studies. it is constructed from fairly inexpensive components, and typically uses 5 mg of catalyst and flow rates of 1 to 5 ml/h, so only small quantities of feedstock need to be handled. the design allows control of the thermodynamic water activity of the feed, and works with temperatures up to at least 80 degrees c. the reactor has been operated with both n ...200111114661
enzyme immobilization in silica-hardened this study we describe a novel method for immobilizing enzymes in a solid nanocomposite matrix based on gelatin gels, which are subsequently hardened by in situ polymerization of tetraethoxysilane (teos). chromobacterium viscosum lipase is taken as the example. this immobilization method possesses the advantages of enzyme entrapment in microemulsions, together with newly beneficial qualities, such as transparency, which permits direct spectroscopic investigation, and considerable mechanical s ...200111114662
increased activity of chromobacterium viscosum lipase in aerosol ot reverse micelles in the presence of nonionic surfactants.modification of aot reverse micellar systems with various alkyl glucosides and nonionic surfactants was attempted in order to improve the activity to chromobacterium viscosum lipase. tweens and tritons, having the poly(oxyethylene) chain, have been shown to be solubilized at the oil-water interface of aot micelles. alkyl glucosides were also solubilized at the interface. these additives form mixed micelles with aot and increase the concentration of the micelles. in contrast, spans were found to ...19937692888
fatty acid steryl, stanyl, and steroid esters by esterification and transesterification in vacuo using candida rugosa lipase as catalyst.sterols (sitosterol, cholesterol, stigmasterol, ergosterol, and 7-dehydrocholesterol) and sitostanol have been converted in high to near-quantitative yields to the corresponding long-chain acyl esters via esterification with fatty acids or transesterification with methyl esters of fatty acids or triacylglycerols using lipase from candida rugosa as biocatalyst in vacuo (20-40 mbar) at 40 degrees c. neither organic solvent nor water is added in these reactions. under similar conditions, cholestero ...200111170561
third generation cephalosporin-resistant gram-negative bacilli in the feces of hospitalized view of the widespread use of third generation cephalosporins in hospitalized infants, we attempted to determine whether their use was associated with the emergence of resistance in fecal gram-negative bacilli. stools from infants hospitalized for varying durations were cultured on macconkey agar containing 4 micrograms/ml of cefotaxime. all isolates growing on this medium were identified and their susceptibilities to 29 antimicrobial agents were determined. sixty-five infants were studied of ...19957746715
methods for detecting acylated homoserine lactones produced by gram-negative bacteria and their application in studies of ahl-production the process of evaluating the role of acylated homoserine lactones (ahls) in food-spoiling gram-negative bacteria, we have combined a range of bacterial ahl monitor systems to determine the ahl-profile and the kinetics of ahl-production. ahl production from 148 strains of enterobacteriaceae isolated from foods was tested using escherichia coli psb403 (luxr), agrobacterium tumefaciens a136 (trar) and both induction and inhibition of chromobacterium violaceum cv026 (cvir). all strains except on ...200111240047
successful treatment of an infant with chromobacterium violaceum sepsis.chromobacterium violaceum sepsis, a rarely reported phenomenon, has a high mortality rate. we report a unique case of c. violaceum sepsis in an infant. a 4-month-old girl presented to our institution with fever, pustular skin lesions, and distended abdomen, as well as diminished activity and mental status. radiological investigation revealed brain, lung, and hepatic abscesses. the infant was successfully treated with trimethoprim-sulfamethoxazole and ciprofloxacin.200111247733
expression and partial characterization of an elastase from chromobacterium violaceum.chromobacterium violaceum was recovered at necropsy from the lungs, liver, spleen, and an interscapular abscess of a chinese red panda (strain 98-9187) [j. vet. diagn. invest. 12 (2000) 177]. as the lungs exhibited extensive, necrotizing lesions harboring bacterial aggregates, we sought to determine whether c. violaceum produced an elastase that might in part account for these lesions. the c. violaceum type strain (atcc 12472(t)) and strain 98-9187 were shown to exhibit elastolytic activity by e ...200111278124
crystallization and preliminary x-ray analysis of ind, an enzyme with indole oxygenase activity from chromobacterium violaceum.ind, a redox flavoprotein from chromobacterium violaceum has been crystallized in the presence and absence of nadh. the crystals belong to the space group p41212 or its enantiomorph p43212 with a = 73.9 and c = 153.6 a. there is one molecule per asymmetric unit and the crystals diffract beyond 2.1 a resolution.19989761866
molecular basis for enantioselectivity of lipase from chromobacterium viscosum toward the diesters of 2,3-dihydro-3-(4'-hydroxyphenyl)-1,1,3-trimethyl-1h-inden-5-ol.2,3-dihydro-3-(4'-hydroxyphenyl)-1,1,3-trimethyl-1h-inden-5-ol, 1, is a chiral bisphenol useful for preparation of polymers. previous screening of commercial hydrolases identified lipase from chromobacterium viscosum (cvl) as a highly regio- and enantioselective catalyst for hydrolysis of diesters of 1. the regioselectivity was > or =30:1 favoring the ester at the 5-position, while the enantioselectivity varied with acyl chain length, showing the highest enantioselectivity (e = 48 +/- 20 s) for ...200111325269
gene synthesis, expression in e. coli, and in vitro refolding of pseudomonas sp. kwi 56 and chromobacterium viscosum lipases and their chaperones.pseudomonas lipases are industrially used as detergent additives, in the food industry, and in organic synthesis. currently, these lipases are either isolated from wild-type strains or overexpressed in recombinant pseudomonas host strains which may be subject to special safety regulations and thus be unsuitable for enzyme engineering via directed evolution. here we describe the heterologous expression of two pseudomonas lipases in escherichia coli. the lipase genes of pseudomonas sp. kwi 56 (rec ...200111330714
case report and review of chromobacterium sepsis--a gram-negative sepsis mimicking melioidosis.chromobacterium violaceum has recently been recognised as a pathogen which can cause life-threatening disease. it is the only chromobacterium species which is pathogenic to humans. due to its unfamiliarity, clinicians often do not appreciate its importance when it is isolated in sterile cultures and may dismiss it as a "containment". it is therefore important for us to be aware of this infection and its clinical spectrum since it is a disease of the tropics. we report a paediatric case of docume ...19979294341
on the inhibition of microbial lipases by tetrahydrolipstatin. 19979309654
inhibition of lipases from chromobacterium viscosum and rhizopus oryzae by tetrahydrolipstatin.tetrahydrolipstatin is known as an inhibitor for pancreatic lipase but not for microbial lipases. in this paper we demonstrate that in the presence of water-insoluble substrates like tributyrin or olive oil, tetrahydrolipstatin inhibits the lipases of chromobacterium viscosum and rhizopus oryzae, although with different potency. in contrast to porcine pancreatic lipase, which forms an irreversible and covalent enzyme-inhibitor complex with tetrahydrolipstatin, the inhibition of the microbial lip ...19989461253
regioselectivity and fatty acid specificity of chromobacterium viscosum lipase.the fatty acid specificity of chromobacterium viscosum lipase was studied by comparing the pseudo-first-order rate constants for the transesterification of different fatty acid methyl esters with 1-propanol in dry acetonitrile as solvent. it was found that this enzyme shows a significant preference towards long chain fatty acids and, for chains with the same length, towards saturated ones. the same enzyme was used to study the esterification of sorbitol and decanoic acid. a mixture of mono-, di- ...19947858979
production of n-acyl homoserine lactones by gram-negative bacteria isolated from contact lens wearers.the purpose of this study was to investigate the production of n-acyl-homoserine lactone (ahl) signal molecules in ocular gram-negative bacteria. a total of 91 ocular strains isolated from contact lens adverse response patients and asymptomatic subjects were used in the study. these included acinetobacter, aeromonas hydrophila, escherichia coli, haemophilus influenzae, klebsiella oxytoca, pseudomonas aeruginosa, serratia liquefaciens, serratia marcescens, and stenotrophomonas maltophilia. the bi ...200111446456
a second quorum-sensing system regulates cell surface properties but not phenazine antibiotic production in pseudomonas aureofaciens.the root-associated biological control bacterium pseudomonas aureofaciens 30-84 produces a range of exoproducts, including protease and phenazines. phenazine antibiotic biosynthesis by phzxyfabcd is regulated in part by the phzr-phzi quorum-sensing system. mutants defective in phzr or phzi produce very low levels of phenazines but wild-type levels of exoprotease. in the present study, a second genomic region of strain 30-84 was identified that, when present in trans, increased beta-galactosidase ...200111526037
antileishmanial activity of the violacein extracted from chromobacterium violaceum. 200111533018
preliminary study on hydrophobic interaction chromatography of chromobacterium viscosum lipase on polypropylene glycol immobilized on sepharose.the purification of chromobacterium viscosum lipase was performed using a polypropylene glycol-sepharose gel. the influence of the mobile phase composition on the chromatographic behaviour of chromobacterium viscosum lipase was studied and it was found that the retention of lipase depends on the salt used and increased with ionic strength. using 20% (w/v) ammonium sulphate in the eluent, a total retention of lipase on the column was obtained.19989513291
[pleural empyema caused by flavimonas oryzihabitans in a healthy male]. 200111562334
purification and partial characterization of an amino acid alpha,beta- dehydrogenase, l-tryptophan 2',3'-oxidase from chromobacterium violaceum.l-tryptophan 2',3'-oxidase is a novel enzyme that specifically catalyzes the alpha,beta-dehydrogenation of l-tryptophan derivatives. it was extracted from chromobacterium violaceum and purified 108-fold to apparent homogeneity with a 34% overall recovery. the molecular weight of the native enzyme is approximately 680,000, and its isoelectric point is nearly equal to 4. sds-polyacrylamide gel electrophoresis showed that the enzyme is composed of two components with molecular weight of approximate ...19948027079
laribacter hongkongensis gen. nov., sp. nov., a novel gram-negative bacterium isolated from a cirrhotic patient with bacteremia and empyema.a bacterium was isolated from the blood and empyema of a cirrhotic patient. the cells were facultatively anaerobic, nonsporulating, gram-negative, seagull shaped or spiral rods. the bacterium grows on sheep blood agar as nonhemolytic, gray colonies 1 mm in diameter after 24 h of incubation at 37 degrees c in ambient air. growth also occurs on macconkey agar and at 25 and 42 degrees c but not at 4, 44, and 50 degrees c. the bacterium can grow in 1 or 2% but not 3, 4, or 5% nacl. no enhancement of ...200111724825
molecular cloning and expression of mn(2+)-dependent sphingomyelinase/hemolysin of an aquatic bacterium, pseudomonas sp. strain tk4.we report here the molecular cloning and expression of a hemolytic sphingomyelinase from an aquatic bacterium, pseudomonas sp. strain tk4. the sphingomyelinase gene was found to consist of 1,548 nucleotides encoding 516 amino acid residues. the recombinant 57.7-kda enzyme hydrolyzed sphingomyelin but not phosphatidylcholine, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, or phosphatidylethanolamine, indicating that the enzyme is a sphingomyelin-specific sphingomyelinase c. the hydr ...200211751833
identification of metal ligands in cu(ii)-inhibited chromobacterium violaceum phenylalanine hydroxylase by electron spin echo envelope modulation analysis of histidine to serine mutations.phenylalanine hydroxylase from chromobacterium violaceum (cvpah) is known to bind an equivalent of divalent copper. the "metal-free" form of the protein is fully active, and cu(ii) is now shown to be an inhibitor of cvpah rather than an activator of the enzyme [carr, r. t., & benkovic, s. j. (1994) biochemistry 32, 14132-14138]. on the basis of amino acid sequence homology, the metal binding site may be related to those of rat liver pah and other eukaryotic pterin-dependent hydroxylases, which r ...19948031788
fatal chromobacterium violaceum septicaemia.a 19-year-old malay male succumbed to a septicaemia caused by chromobacterium violaceum 11 days after onset of illness. the organism is a common soil saprophyte and may be considered as contaminant on culture. it is essential to recognise its clinical significance in purulent processes so that appropriate therapy can be instituted. we report the first fatal case of chromobacterium violaceum infection in the university hospital, kuala lumpur.19938153700
effect of enzymes on the composition and structure of chromobacterium violaceum cell envelopes.cell envelopes of chromobacterium violaceum were isolated and treated under controlled conditions with trypsin, pronase, lipase, phospholipase c, lysozyme, and a mixture of enzymes produced by a bacteriolytic pseudomonas sp. after each enzyme treatment, losses in dry weight, protein, lipid, carbohydrate, 2,6-diaminopimelic acid, and total phosphorus were determined. electron-microscopic examination of the enzyme-treated envelopes indicated complete or partial loss of envelope rigidity or some en ...19695776532
characterization of n-acyl homoserine lactone overproducing mutants of burkholderia multivorans atcc 17616.burkholderia multivorans atcc 17616 ordinarily produces insufficient amounts of n-acyl homoserine lactones (ahls) to promote ahl-dependent formation of the pigment violacein by the reporter strain chromobacterium violaceum cv026. we have isolated ahl-overproducing mutants of strain 17616 by screening for variants which do cross-feed ahls to strain cv026. nucleotide-sequence analysis of the bmuir locus which specifies ahl synthase (bmui) and ahl-binding transcriptional activator protein (bmur) in ...200211814664
effect of cold temperatures on the viability of chromobacterium violaceum.the effect of low, nonfreezing temperatures on the viability of five strains of chromobacterium violaceum was studied. the viability of cultures grown at 30 c was determined after exposure to various diluents held at 0 to 2 c. a culture diluted at its growth temperature served as the control. cells of strain n were most sensitive in the early part of the exponential phase of growth. cells of strains 252 and 341 were most sensitive in the late exponential, early stationary phase of growth. cells ...19695774755
fluorescent inhibitors reveal solvent-dependent micropolarity in the lipid binding sites of lipases.triacylglycerol analogue p-nitrophenyl phosphonates specifically react with the active-site serine of lipolytic enzymes to give covalent lipase-inhibitor complexes, mimicking the first transition state which is involved in lipase-mediated ester hydrolysis. here we report on a new type of phosphonate inhibitors containing a polarity-sensitive fluorophore to monitor micropolarity around the active site of the enzyme in different solvents. the respective compounds are hexyl and methyl dimethylamino ...200212009403
[synthesis of signaling n-acyl-homoserine-lactones participating in quorum sensing in rhizosphere and soil bacteria pseudomonas and xanthomonas].signaling molecules assigned to n-acyl-homoserine-lactones (ahl) serve as autoinducers for the genes controlling the quorum sensing regulatory system. in many gram-negative bacteria, ahl are the key factors responsible for density-dependent regulation of exoenzyme and secondary metabolite production; they also participate in interaction between bacteria and higher organisms. the soil and rhisosphere bacteria pseudomonas and xanthomonas from different geographical zones of russia and the former u ...200212018176
chromobacterium violaceum septicemia.chromobacterium violaceum is an extremely rare human pathogen. we report a rare case of septicemia with multiple abscesses and otitis media in a newborn caused by chromobacterium violaceum.200212019559
building blocks for the solution phase synthesis of oligonucleotides: regioselective hydrolysis of 3',5'-di-o-levulinylnucleosides using an enzymatic approach.a short and convenient synthesis of 3'- and 5'-o-levulinyl-2'-deoxynucleosides has been developed from the corresponding 3',5'-di-o-levulinyl derivatives by regioselective enzymatic hydrolysis, avoiding several tedious chemical protection/deprotection steps. thus, candida antartica lipase b (cal-b) was found to selectively hydrolyze the 5'-levulinate esters, furnishing 3'-o-levulinyl-2'-deoxynucleosides 3 in >80% isolated yields. on the other hand, immobilized pseudomonas cepacia lipase (psl-c) ...200212076150
[bromo- and iodo-containing alkaloids from marine microorganisms and sponges].the taxonomic distribution, structure, and biological activity of halogenated alkaloids isolated from marine microorganisms and sponges are reviewed. the structures of nearly 140 natural bromo- and iodo-containing alkaloids are shown.200212077845
multiple intensified performance of an enzyme-catalyzed reaction in organic medium.a lipase-catalyzed glycerolysis reaction (a transesterification between polyunsaturated fatty acid ethyl ester [pufa] and glycerol) was investigated. its performance was multiply intensified by (1) using a lipase having high specific activity, high activity in organic solvent, and high tolerance in organic solvent; (2) immobilization on fine caco3 powder (cheap and safe material, easy physical adsorption method of immobilization, reusable); (3) reaction in vacuo resulting in 100% conversion and ...199810075632
molecular dynamics of microbial lipases as determined from their intrinsic tryptophan fluorescence.we have studied the intrinsic tryptophan fluorescence of the lipases from chromobacterium viscosum (cvl), pseudomonas species (psl), and rhizopus oryzae (rol) in aqueous buffer, zwitterionic detergent micelles, and isopropanol-water mixtures. it was the purpose of this study to obtain information about biophysical properties of the respective enzymes under conditions that modulate enzyme activities and stereoselectivities to a significant extent. according to their decay-associated emission spec ...199910388774
an examination of the copper requirement of phenylalanine hydroxylase from chromobacterium violaceum.phenylalanine hydroxylase from chromobacterium violaceum (cvpah) was classified as a copper metalloenzyme by virtue of a 1/1 cu/enzyme stoichiometry and its inhibition with various chelators [pember, s. o., villafranca, j. j., & benkovic, s. j. (1986) biochemistry 25, 6611]. we have prepared "copper-free" cvpah by extraction with dtt. these preparations retained full activity though the cu/enzyme ratio averaged 0.015. reconstitution by extraneous copper was disproved by measuring a cu/enzyme rat ...19938260496
chromobacterium violaceum: a case of diarrhea in senegal.a 5-year-old infant with diarrhea had heavy growth of chromobacterium violaceum cultured from stool. this organism is restricted geographically between latitudes 35 degrees n and 35 degrees s. it can cause sepsis and various focal infections but is not a well-known cause of diarrhea.200212182388
chromobacterium violaceum infection in children: a case of fatal septicemia with nasopharyngeal abscess and literature review.this previously healthy 5-year-old boy initially presented with fever and purulent conjunctivitis. the course evolved rapidly into preseptal and facial cellulitis, nasopharyngeal abscess and sepsis. chromobacterium violaceum was isolated from conjunctival exudate and blood cultures. he received intravenous cefazolin therapy for 2 days, followed by penicillin, oxacillin and netilmicin. however, no improvement was noted, and he died on the fifth days of illness.200212237610
chromobacterium violaceum sepsis accompanied by bacteria-associated hemophagocytic syndrome in a japanese man. 199910421288
mechanism, regulation, and ecological role of bacterial cyanide biosynthesis.a few bacterial species are known to produce and excrete hydrogen cyanide (hcn), a potent inhibitor of cytochrome c oxidase and several other metalloenzymes. in the producer strains, hcn does not appear to have a role in primary metabolism and is generally considered a secondary metabolite. hcn synthase of proteobacteria (especially fluorescent pseudomonads) is a membrane-bound flavoenzyme that oxidizes glycine, producing hcn and co2. the hcnabc structural genes of pseudomonas fluorescens and p. ...200010763748
intrinsic conformation of lipid a is responsible for agonistic and antagonistic activity.lipopolysaccharides (lps, endotoxin) represent a major virulence factor of gram-negative bacteria, which can cause septic shock in mammals, including man. the lipid anchor of lps to the bacterial outer membrane, lipid a, exhibits a peculiar chemical structure, harbours the 'endotoxic principle' of lps and is also responsible for the expression of pathophysiological effects. chemically modified lipid a can be endotoxically inactive, but may express strong antagonistic activity against endotoxical ...200010806403
order of substrate binding in bacterial phenylalanine hydroxylase and its mechanistic implication for pterin-dependent oxygenases.phenylalanine hydroxylase (pah) is a pterin-dependent non-heme metalloenzyme that catalyzes the oxidation of phenylalanine to tyrosine, which is the rate-limiting step in the catabolism of phe. chromobacterium violaceum phenylalanine hydroxylase (cpah) has been prepared and its steady-state mechanism has been investigated. the enzyme requires iron for maximal activity. initial rate measurements, done in the presence of the 6,7-dimethyl-5,6,7,8-tetrahydropterin (dmph(4)) cofactor, yielded an aver ...200312459906
phagocyte nadph oxidase, but not inducible nitric oxide synthase, is essential for early control of burkholderia cepacia and chromobacterium violaceum infection in mice.reactive oxygen and nitrogen intermediates have critical, partially overlapping roles in host defense against a variety of pathogens. using mice deficient in generating phagocyte superoxide (p47(phox)(-/-)) and mice deficient in generating inducible nitric oxide synthase (inos(-/-)), we examined the roles of these reactive species in host defense against burkholderia cepacia and chromobacterium violaceum, organisms known to have unusual virulence in chronic granulomatous disease. intraperitoneal ...200312496167
a spectroscopic analysis of thermal stability of the chromobacterium viscosum lipase.the thermal stability of the lipase from chromobacterium viscosum was assessed by deactivation (loss of activity), fluorescence, circular dichroism (cd) and static light scattering (sls) measurements. lipase fluorescence emission is dominated by the tryptophyl contribution. an increase in the tyrosyl contribution from 2 to 16% was only observed upon prolonged incubation at 60 degrees c. the effect of temperature on the tryptophyl quantum yield was studied and two activation energies were calcula ...200011099174
pcr-assisted contig extension: stepwise strategy for bacterial genome closure.finishing is rate limiting for genome projects, and improvements in the efficiency of complete genome-sequence compilation will require improved protocols for gap closure. here we report a novel approach for extending shotgun contigs and closing gaps that we termed pcr-assisted contig extension (pace). pace depends on the capture of rare mismatched interactions that occur between arbitrary primers and template dna of unknown sequence, even under highly stringent conditions, by means of elevated ...200312661167
detection and characterization of quorum sensing signal molecules in acinetobacter strains.quorum sensing is a widespread regulatory mechanism among gram-negative bacteria. in this study, acinetobacter strains were assayed for the presence of quorum sensing signal molecules capable of activating n-acylhomoserine lactone biosensors. by using an agrobacterium tumefaciens reporter strain it was shown that all the cultures produced two to four detectable signal molecules with different chromatographic patterns. in a. calcoaceticus bd413 supernatants four compounds were detected in a time- ...200111297357
fatal septicaemia caused by chromobacterium violaceum.we report a case of chromobacterium violaceum septicaemia in a 10-year old boy admitted to hospital in september 2001, two weeks after he suffered a crush injury of the left foot. in spite of surgical debridement and antibiotics his condition worsened and he developed multiple liver and lung abscesses. he died one week after admission and a blood culture grew chromobacterium violaceum.200312795018
[the inhibitory effect of extracts from galla chinensis on marine fouling bacteria].to observe the activity of extracts from galla chinensis with different solvents against marine fouling bacteria in vitro.200312795221
quorum sensing and chromobacterium violaceum: exploitation of violacein production and inhibition for the detection of n-acylhomoserine lactones.quorum sensing relies upon the interaction of a diffusible signal molecule with a transcriptional activator protein to couple gene expression with cell population density. in gram-negative bacteria, such signal molecules are usually n-acylhomoserine lactones (ahls) which differ in the structure of their n-acyl side chains. chromobacterium violaceum, a gram-negative bacterium commonly found in soil and water, produces the characteristic purple pigment violacein. previously the authors described a ...19979421896
chromobacterium violaceum bacteremia: a case report.chromobacterium violaceum is confined in tropical and subtropical regions, which can cause life-threatening disease. it is the only chromobacterium species that is pathogenic to humans. because of its rarity, clinicians often do not appreciate its importance when it is isolated. we report a fulminate fatal case of c. violaceum bacteremia in a 20-year-old male taiwanese. the clinical manifestations were fever and abdominal pain, followed by shock and pulmonary septic embolism. emergent laparotomy ...200312886967
novel bacteria degrading n-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria.bacteria degrading the quorum-sensing (qs) signal molecule n-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic rep-pcr and rrs pcr-rflp profiles. representative strains from each group were identified as members of the genera pseudomonas, comamonas, variovorax and rhodococcus: all these isolates degraded n-acylhomoserine lactones other than the hexanoic acid derivative, albei ...200312904538
chromobacterial infections. 195212981933
reaction of acylated homoserine lactone bacterial signaling molecules with oxidized halogen antimicrobials.oxidized halogen antimicrobials, such as hypochlorous and hypobromous acids, have been used extensively for microbial control in industrial systems. recent discoveries have shown that acylated homoserine lactone cell-to-cell signaling molecules are important for biofilm formation in pseudomonas aeruginosa, suggesting that biofouling can be controlled by interfering with bacterial cell-to-cell communication. this study was conducted to investigate the potential for oxidized halogens to react with ...200111425738
fatal infection by chromobacterium violaceum. 195313085740
variation in pigmentation and morphology of colonies of gelatinous strains of chromobacterium species from soil. 195313096508
bacterial endocarditis due to chromobacterium prodigiosum; report of a case. 195413149883
outbreaks of disease in animals associated with chromobacterium violaceum. i. the disease in swine. 195413162910
[the effect of chromobacterium prodigiosum on the growth of bacterium bifidum]. 195413188176
[biological research on gelatinolytic, fibrinolytic and antidotal enzymes present in culture filtrates of certain microorganisms and in particular in penicillium notatum, actinomyces griseus, bacillus subtilis, pseudomonas aeruginosa, proteus, chromobacterium prodigiosum and staphylococcus pyogenes]. 195413195286
[isolation of chromobacterium violaceum from hepatic lesions seen in a monkey cercopithecus cephus; study and pathogenecity]. 195413218378
morphological and physiological characteristics of the genus chromobacterium. 195613319251
[not available]. 195513329728
nitrate reduction in the genus chromobacterium. 195613340700
violacein biotransformation by basidiomycetes and bacteria.the biotransformation study of the pigment (violacein) produced by chromobacterium violaceum, was verified by its decolorization utilizing six different organisms in liquid and solid media.200111559408
cultural and biochemical characteristics of the genus chromobacterium. 195613357716
the change from polar to peritrichous flagellation in chromobacterium spp. 195613357717
pseudohaemoptysis due to chromobacterium prodigiosum. 195713417607
the isolation of d-glycero-d-galactoheptose and other sugar components from the specific polysaccharide of chromobacterium violaceum (bn). 195713459897
[classification of pseudomonadaceae]. 195713470460
[chromobacteria in human pathology; human chromobacterium infections]. 195813543121
a water-soluble, diffusible pigment produced by a strain of serratia marcescens (chromobacterium prodigiosum). 195813590216
[culture of bacteria by symbiotic procedure with a new form of metagenetic plate. i]. 195813595734
[culture of bacteria by symbiotic procedure with a new form of metagenetic plate. ii]. 195813595735
the isolation of d-fucosamine from the specific polysaccharide of chromobacterium violaceum (nctc 7917). 195813607435
production of hemolysis by chromobacterium violaceum. 195913626901
phenylalanine hydroxylase from chromobacterium violaceum. uncoupled oxidation of tetrahydropterin and the role of iron in hyroxylation.a gene encoding phenylalanine hydroxylase has been cloned from chromobacterium violaceum and expressed in escherichia coli. the purified phenylalanine hydroxylase contains copper, which does not support enzymatic activity. upon removal of copper by dithiothreitol (dtt), the enzyme contains substoichiometric amounts of calcium and zinc but little or no redox-active metal ions. the copper-depleted hydroxylase catalyzes the phenylalanine-dependent oxidation of 6, 7-dimethyltetrahydropterin (dmph4) ...19989748224
chromobacterium violaceum infection in brazil. a case report.we report the second case of infection with chromobacterium violaceum that occurred in brazil. a farm worker living in the state of são paulo presented fever and severe abdominal pain for four days. at hospitalization the patient was in a toxemic state and had a distended and painful abdomen. chest x-ray and abdominal ultrasound revealed bilateral pneumonia and hypoechoic areas in the liver. the patient developed failure of multiple organs and died a few hours later. blood culture led to isolati ...200010810326
plants secrete substances that mimic bacterial n-acyl homoserine lactone signal activities and affect population density-dependent behaviors in associated gram-negative bacteria, many important changes in gene expression and behavior are regulated in a population density-dependent fashion by n-acyl homoserine lactone (ahl) signal molecules. exudates from pea (pisum sativum) seedlings were found to contain several separable activities that mimicked ahl signals in well-characterized bacterial reporter strains, stimulating ahl-regulated behaviors in some strains while inhibiting such behaviors in others. the chemical nature of the active mimic com ...200010830263
violacein cytotoxicity and induction of apoptosis in v79 cells.violacein, a pigment produced by chromobacterium violaceum, is reported to be a potential drug for the treatment of chagas' disease. violacein is also effective against leukemia and lymphoma cells in culture (ic50 10(-8) m). changes in the nuclear acid content, 3-(4,5-dimethylthiazole-2-yl)-2,5-biphenyl tetrazolium bromide reduction and neutral red uptake in these cells were used to evaluate the cytotoxicity of violacein in v79 chinese hamster (m-8) fibroblasts. violacein was highly cytotoxic to ...200011149754
acyl-homoserine lactone production is more common among plant-associated pseudomonas spp. than among soilborne pseudomonas spp.a total of 137 soilborne and plant-associated bacterial strains belonging to different pseudomonas species were tested for their ability to synthesize n-acyl-homoserine lactones (nahl). fifty-four strains synthesized nahl. interestingly, nahl production appears to be more common among plant-associated than among soilborne pseudomonas spp. indeed, 40% of the analyzed pseudomonas syringae strains produced nahl which were identified most often as the short-chain nahl, n-hexanoyl-l-homoserine lacton ...200111229911
biodegradation of poly(tetramethylene succinate-co-tetramethylene adipate) and poly(tetramethylene succinate) through water-soluble products.poly(tetramethylene succinate-co-tetramethylene adipate) (pbsa) and poly(tetramethylenesuccinate) (pbs) were hydrolyzed experimentally into water-soluble oligomers and monomers by chromobacterium extracellular lipase. the oligomers were identified by high-performance liquid chromatography-mass spectrometry and 1h-nuclear magnetic resonance, which indicated that a total of 28 oligomer species were liberated from pbsa, and that 13 of them were identical to the hydrolysates from pbs. moreover, 20 o ...200111337881
alginate as a macroaffinity ligand and an additive for enhanced activity and thermostability of lipases.lipases are being employed increasingly for the synthesis of drug intermediates and pharmaceutically important molecules as well as for the resolution of racemic mixtures for obtaining physiologically active enantiomers. alginate was used as a macroaffinity ligand to purify lipases from chromobacterium viscosum, porcine pancreas and wheatgerm by employing the technique of affinity precipitation. in all the cases, the purified preparation showed a single band on sds/page. the process gave adequat ...200111389669
biogenic production of cyanide and its application to gold recovery.chromobacterium violaceum is a cyanogenic (cyanide-producing) microorganism. cyanide is used on an industrial scale to complex and recover gold from ores or concentrates of ores bearing the precious metal. a potentially useful approach in gold mining operations could be to produce cyanide biologically in relatively small quantities at the ore surface. in this study, c. violaceum grown in nutrient broth formed a biofilm and could complex and solubilize 100% of the gold on glass test slides within ...200111420652
chromobacterium violaceum: a review of pharmacological and industiral perspectives.violet-pigmented bacteria, which have been described since the end of the 19th century, are occasionally the causative agent of septicemia and sometimes cause fatal infection in human and animals. bacteria, producing violet colonies due to the production of a nondiffusible pigment violacein, were classified as a redefined genus chromobacterium. chromobacterium violaceum is gram-negative, and saprophyte from soil and water is normally considered nonpathogenic to human, but is an opportunistic pat ...200111596879
histone deacetylase inhibitor fk228 inhibits tumor angiogenesis.fk228 (formerly fr901228) was recently isolated from chromobacterium violaceum as a potent antitumor agent and its biologic target protein was identified as histone deacetylase (hdac). because of its unique chemical structure (i.e., bicyclic depsipeptide) and activity profile in the national cancer institute's developmental therapeutics program, fk228 is currently in a phase i clinical trial for cancer therapy. in the present study, we investigated the antiangiogenic activity of fk228 in vivo an ...200211774279
chromobacterium violaceum infection: a rare but frequently fatal disease.the authors report a rare case of chromobacterium violaceum infection in a 2-month-old child. she presented with an apparently localized abscess, which appeared to respond well to therapy. however, the infection recurred later with a fulminant course. the organism frequently is dismissed as a contaminant or not identified properly, and the fatality rates are high. a high degree of awareness about this infection needs to be created, especially among pediatricians and pediatric surgeons, because c ...200211781998
a comparison of lipase-catalysed ester and lactone synthesis in low-water systems: analysis of optimum water activity.we investigated the effects of the lyophilisation medium (enzyme plus buffer salt and additives) and of water activity (a(w)) on the catalytic properties of lipase from chromobacterium viscosum (lipase cv) in organic solvents; catalysis of ester and lactone synthesis were compared and, despite the similarities of the reactive groups involved in these reactions, some interesting differences were observed. including 2-[n-morpholino]ethanesulfonic acid (mes) buffer in the lyophilisation medium of l ...200211807759
synthesis of monoacyl a-ring precursors of 1alpha,25-dihydroxyvitamin d3 through selective enzymatic efficient synthesis of monoacylated 1alpha,25-dihydroxyvitamin d3 a-ring precursors 15, 16, 18, and 19 has been described through an enzymatic hydrolysis process. candida antarctica a lipase (cal-a) hydrolyzes the c-5 acetate ester in trans stereoisomers 9 and 13, with complete and high selectivity, respectively. in the case of cis isomers 11 and 14, chromobacterium viscosum lipase (cvl) is the enzyme of choice, exhibiting opposite selectivity for these two enantiomers. this lipase selectivel ...200211846672
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