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a comparative study of virulent and avirulent strains of chromobacterium violaceum.a clinical isolate and a soil isolate of chromobacterium violaceum were compared to determine differences in virulence-related characteristics. purified lipopolysaccharide (endotoxin) from the virulent, clinical strain was more reactive than that from the avirulent soil strain as determined by the limulus amebocyte lysate assay. there were no differences in hemolysin or cyanide production between the two strains. the virulent strain was more resistant to phagocytosis and intracellular killing by ...19882843271
aerocavin, a new antibiotic produced by chromobacterium violaceum.a new antibiotic, aerocavin, has been isolated from fermentation broths of a non-pigmented strain of chromobacterium violaceum. the structure 1 was deduced from its spectroscopic properties and x-ray diffraction analysis. aerocavin exhibits activity in vitro against gram-positive and gram-negative bacteria.19883372350
aerocyanidin, a new antibiotic produced by chromobacterium violaceum.aerocyanidin, a new antibiotic containing an isonitrile group, has been isolated from fermentations of chromobacterium violaceum atcc 53434. structure 1 was assigned on the bais of spectroscopic characterization of the antibiotic and of a degradation product that results from treatment with base. the antibiotic is primarily active against gram-positive bacteria.19883372351
comparison of the in vitro activity of ciprofloxacin and 24 other antimicrobial agents against clinical strains of chromobacterium violaceum.eleven clinical strains of chromobacterium violaceum were tested for their susceptibility to 25 antimicrobial agents. ciprofloxacin was the most active of the compounds tested although norfloxacin and pefloxacin were highly active. no resistance was detected to mezlocillin, piperacillin, apalcillin, imipenem, and aztreonam while a single strain was resistant to ticarcillin. among the cephalosporin/cephamycin group only cefotetan showed good in vitro activity. gentamicin was more active than amik ...19883168426
production of biosurfactants from sugar alcohols and vegetable oils catalyzed by lipases in a nonaqueous medium.porcine pancreatic and chromobacterium viscosum lipases catalyze transesterification reactions between a number of sugar alcohols and various plant and animal oils in dry pyridine. the products of this process have been identified as primary monoesters of sugar alcohols and fatty acids. these enzymatically prepared sugar alcohol esters have been found to be excellent surfactants in terms of their ability to reduce interfacial and surface tensions and to stabilize emulsions.198818584594
bacterial chemistry-iii: preliminary studies on trypanosomal activities of chromobacterium violaceum products.it has been found that the pigment-i from chromobacterium violaceum, 3-[1,2-dihydro5-(5-hydroxy-1h-indol-3-yl)-2-oxo-3h-pyrrol-3-yli diene] 1,3-dihydro-2h-indol-2-one, has trypanocide activity. the formylated derivatives, pigment-iii, immobilized 100% of the trypanosoma cruzi at a level of 46 microm after 48 h of interaction with a total growth inhibition in the same period. pigment-i exhibited low toxicity and a dna synthesis inhibition similar to that of nifurtimox, a known trypanocide compoun ...19892512826
near-fatal septicaemia with chromobacterium violaceum.chromobacterium violaceum is a gram-negative organism which normally inhabits water and soil. human infection is unusual and is associated with a high mortality rate. we describe a typical case of disseminated infection with chr. violaceum in a male carpet cleaner. the possible origin and treatment of the infection is discussed.19892733620
an acute pleuropneumonia in a pig caused by chromobacterium violaceum.a 2.5-month-old, 30 kg duroc pig died 10 days after showing clinical signs of dyspnoea and diarrhoea. acute necrotizing and fibrinous pleuropneumonia with locally extensive lesions was found. chromobacterium violaceum was isolated from pneumonic lung tissues and intratracheal inoculation of a pure culture into two spf pigs reproduced lesions similar to those found in the natural infection.19892760278
the use of tween 20 in a sensitive turbidimetric assay of lipolytic enzymes.a turbidimetric esterase assay was developed using a tween 20 solution in the presence of cacl2 and lysobacter enzymogenes esterase (ec 3.1.1.1) as the enzyme source. the reaction was followed by measuring the increase in the optical density at 500 nm (od500) due to the hydrolytic release of the fatty acids from tween 20 and their precipitation as the calcium salts. concentrations of 1.8% tween and 3 mm cacl2 were found to be optimal for the assay of 0.036 to 0.15 esterase units in a 4-ml reacti ...19892501015
bacterial ethylene synthesis from 2-oxo-4-thiobutyric acid and from methionine.the ability of selected bacterial cultures to synthesize ethylene during growth in nutrient broth supplemented with methionine or 2-oxo-4-methylthiobutyric acid (kmba) was examined. although most cultures transformed kmba into ethylene, only those of escherichia coli spao and chromobacterium violaceum were able to convert exogenously added methionine to ethylene. in chemically defined media, e. coli spao produced the highest amounts of ethylene from methionine and kmba. this capability was affec ...19892559143
effect of growth conditions on production of violacein by chromobacterium violaceum (bb-78 strain).1. chromobacterium violaceum (strain bb-78 isolated in brazil) produces violacein, a substance potentially useful in phototherapy and with antibiotic and trypanocide activity. culture conditions were optimized for the production of violacein and changes in nutrients, temperature and ph were correlated to cellular growth. 2. methionine was the only absolute requirement for growth. alanine, arginine, tryptophan and vitamin b12 stimulated growth and the microorganism utilized both the d and l forms ...19892620169
mechanistic studies on phenylalanine hydroxylase from chromobacterium violaceum. evidence for the formation of an enzyme-oxygen complex.steady-state kinetic analysis of pterin-dependent phenylalanine hydroxylase from chromobacterium violaceum indicated that the enzyme follows a partially ordered reaction mechanism. the data suggested that oxygen is the first substrate to bind to the enzyme. this result was further supported by rapid-quench experiments in which the enzyme-oxygen complex was trapped to yield product. additional support for the presence of an enzyme-oxygen complex was derived from magnetic susceptibility measuremen ...19892719947
temperature-dependent incorporation of 4-amino-l-arabinose in lipid a of distinct gram-negative bacteria.the presence and the relative amount of 4-amino-l-arabinose in lipopolysaccharides of members of the enterobacteriaceae family and in a single strain of chromobacterium violaceum has been studied with regard to growth-temperature dependent variations. changes in the presence and the amount of 4-amino-l-arabinose (4-aa) were observed in almost all cases, but the variations observed were not consistent among different species. while salmonella minnesota and proteus mirabilis showed higher levels o ...19892583477
bacterial colonization of domestic reverse-osmosis water filtration units.we have analyzed the bacterial content of water from the reservoirs of 300 reverse-osmosis units installed in households. the heterotrophic plate counts on r2a medium (20 and 35 degrees c) ranged from 0 to 10(7) colony forming units per millilitre (cfu/ml). most reservoirs contained water with bacterial counts between 10(4) and 10(5) cfu/ml. the bacteria identified were pseudomonas (not aeruginosa), alcaligenes or moraxella, acinetobacter, flavobacterium, and chromobacterium. this report emphasi ...19892611732
occurrence of drug-resistant bacteria in communal well water around port harcourt, nigeria.a total of 108 raw water samples was collected from 36 wells at nine shanty settlements around port harcourt, nigeria, over a period of 7 months. samples were analysed for their bacteriological quality. selected bacterial strains isolated from the samples were tested for their susceptibility to ten commonly used antibiotics. the organisms isolated include pseudomonas spp., klebsiella spp., staphylococcus spp., proteus spp., enterococcus faecalis, aeromonas spp., escherichia coli, chromobacterium ...19892776852
the pattern of protein synthesis induced by heat-shock of the moderately halophilic bacterium chromobacterium marismortui: protective effect of high salt concentration against the thermal shock.the protein synthetic response to heat shock of the moderately halophilic bacterium chromobacterium marismortui was examined. upon exposure to elevated temperature there is an increased synthesis of a specific subset of proteins (heat shock proteins-hsps) in the molecular weight region of 15 to 90 kd, while normal protein synthesis is severely repressed. the synthesis of hsps reaches a maximum 5 min after heat shock at 42 degrees c. cells recovered their normal protein synthesis patterns rapidly ...19892716536
pneumonia and meningitis caused by a new nonfermentative unknown gram-negative bacterium.seven isolates of an unclassified bacterium resembling flavobacterium spp. were characterized by growth requirements, microscopic examination, biochemical characteristics, antimicrobial susceptibility tests, protein profile analysis, and serologic data. the unclassified isolates were differentiated from flavobacterium meningosepticum, flavobacterium odoratum, flavobacterium balustinum, flavobacterium strain iib, chromobacterium violaceum, aquaspirillum serpens, and pseudomonas spp. the bacterium ...19892504766
endotoxin size in hemodialysis solutions: modifications in presence of concentrated salt solutions and bacterial products. 19902183572
isolation and characterization of acetonitrile utilizing bacteria.bacteria utilizing high concentrations of acetonitrile as the sole carbon source were isolated and identified as chromobacterium sp. and pseudomonas aeruginosa. maximum growth was attained after 96 h of incubation and p. aeruginosa grew slightly faster than chromobacterium sp. the strains were able to grow and oxidize acetonitrile at concentrations as high as 600 mm. however, higher concentrations inhibited growth and oxygen uptake. degradation studies with (14c)acetonitrile indicated 57% of ace ...19901367463
hydrodynamic characterization of chromobacter viscosum lipase. 19902083651
comparative genetic organization of incompatibility group p degradative plasmids.plasmids that encode genes for the degradation of recalcitrant compounds are often examined only for characteristics of the degradative pathways and ignore regions that are necessary for plasmid replication, incompatibility, and conjugation. if these characteristics were known, then the mobility of the catabolic genes between species could be predicted and different catabolic pathways might be combined to alter substrate range. two catabolic plasmids, pss50 and pss60, isolated from chlorobipheny ...19902254257
[first isolation of chromobacterium violaceum strains, also achromogenic, in drinking water]. 19901715722
solution behaviour of chromobacter viscosum and pseudomonas sp. lipases. no evidence of self-association.1. the size of two bacterial lipases was studied by sds/page, sedimentation velocity and sedimentation equilibrium to test for possible self-association behaviour. 2. mr values of selected lipases were obtained from sds/page and sedimentation-velocity measurements, together with an absolute determination by sedimentation equilibrium 3. the mr values obtained in a variety of aqueous solvents indicate that lipases do not self-associate in solution, suggesting the absence of surface hydrophobic pat ...19911996958
cloning and expression of chromobacterium violaceum phenylalanine hydroxylase in escherichia coli and comparison of amino acid sequence with mammalian aromatic amino acid hydroxylases.the complete amino acid sequence (296 amino acids) of chromobacterium violaceum phenylalanine hydroxylase (pah) was determined by nucleotide analysis of a dna clone isolated using both a synthetic oligonucleotide probe based on the nh2-terminal amino acid sequence and an antibody against this enzyme. the apal i fragment (approximately 1.9 kilobase pairs) containing the entire pah gene was subcloned in pbluescript ii and induced by isopropyl-beta-d-thiogalactopyranoside. in order to eliminate fus ...19911655752
reverse enzyme synthesis in microemulsion-based organo-gels.lipase from three different sources has been immobilised in microemulsion-based gels (mbgs) with retention of catalytic activity. such lipase-containing mbgs prove to be novel solid-phase catalysts for use in apolar organic solvents such as n-heptane. using these systems, preparative-scale synthesis of a wide variety of esters under mild conditions was possible with products easily isolated and obtained in high yield. stereoselective esterification of octan-2-ol was observed for all three lipase ...19911707672
survival of the fish pathogen aeromonas salmonicida in seawater.survival of aeromonas salmonicida in natural (non-sterile) seawater, as determined from colony counts on marine agar, was found to be influenced by the presence of potentially inhibitory organisms, i.e., acinetobacter, aeromonas hydrophila, chromobacterium, escherichia coli, flavobacterium and pseudomonas, and their metabolites. yet, samples, thought to be devoid of culturable a. salmonicida, were found to contain cells, which were filterable through 0.22 and 0.45 microns millipore millex porosi ...19911769545
beta-d-glucuronidase (bdg) activity of gram-negative bacteria.bdg is an inducible enzyme that is encoded by the uida gene in escherichia coli. genetic sequences of this gene are present in most if not all e. coli strains regardless of the bdg phenotype. expression of bdg activity can be influenced by lactose-induced catabolite repression or genetic mutations. salmonella, shigella and yersinia strains frequently exhibit positive bdg reaction. bdg activity of strains belonging to genus edwardsiella, serratia, yersinia, vibrio, erwinia, alcaligenes, acinetoba ...19911817425
continuous glycerolysis of olive oil by chromobacterium viscosum lipase immobilized in liposome in reversed micelles.chromobacterium viscosum lipase which has adsorbed on liposome and solubilized in microemulsion droplets of glycerol containing a little amount of water could catalyze the glycerolysis of olive oil. studies on the continuous glycerolysis of olive oil by the immobilized enzyme was done at 37 degrees c in continuous stirred vessel bioreactor with polysulfone membrane. the effect of the flow rate of substrate (olive oil) in isooctane on the conversion and composition of the outlet was investigated ...199118600711
selective separation and purification of two lipases from chromobacterium viscosum using aot reversed micelles.selective separation and purification of two lipases form chromobacterium viscosum were carried out by liquid-liquid extraction using a reversed micellar system. optimum parameters for extraction were determined using a 250 mm aot micellar solution in isooctane. complete separation of the two lipases was achieved at ph 6.0 with a 50mm potassium phosphate buffer solution containing 50 mm kci. by adding 2.5% by volume of ethanol to the lipase-loaded micellar solution, 85% of the extracted lipase c ...199118600731
x-ray absorption studies of the cu-dependent phenylalanine hydroxylase from chromobacterium violaceum. comparison of the copper coordination in oxidized and dithionite-reduced enzymes.the coordination chemistry of the cu sites of phenylalanine hydroxylase (pah) from chromobacterium violaceum has been studied by x-ray absorption spectroscopy (xas). the exafs of the cu(ii) form of the enzyme resembles that of other non-blue copper proteins such as plasma amine oxidases and dopamine-beta-hydroxylase and is characteristic of a mixed n/o coordination shell containing histidine ligation. detailed simulations of the raw exafs data have been carried out using full curved-wave restrai ...19921606153
identification of a neutral lipid core in a transiently expressed and secreted lipoprotein containing an apob-48-like apolipoprotein.the presence of core lipids in lipoproteins expressed and secreted by transfected hepg2 cells was demonstrated by measuring the densities of these lipoproteins before and after treatment with a bacterial lipase specific for neutral lipids. hepg2 cells were reproducibly transfected with prsv/b48, containing a truncated human apolipoprotein b-100 (apob-100) cdna (nucleotides 1 to 6860, where nucleotide 129 is the start of translation). northern blots of cellular message probed with apob-48 showed ...19921569375
chemical and cultural characterization of cdc group wo-1, a weakly oxidative gram-negative group of organisms isolated from clinical sources.ninety-six strains of weakly oxidative gram-negative rods isolated primarily from clinical specimens form a distinct group that has been designated centers for disease control (cdc) group wo-1 (wo stands for weak oxidizer). the phenotypic characteristics of cdc group wo-1 were most similar to those of comamonas acidovorans, pseudomonas mallei, and cdc pink coccoid group iii. the wo-1 group can be differentiated from c. acidovorans by the oxidation of glucose (often weak and sometimes delayed), m ...19921537895
fatal chromobacterium violaceum infections associated with exposure to stagnant waters. 19921528650
stereoselectivity of lipases: esterification reactions of octadecylglycerol.stereoselectivity of several triacylglycerol lipases (ec 3.1.1.3) has been investigated in the enzymatic esterification of rac-1-o-octadecylglycerol with oleic acid in the presence of organic solvents, such as hexane. x-1(3)-o-octadecylmonooleoylglycerols were the only products formed with most lipases; considerable proportions of x-1(3)-o-octadecyldioleoylglycerols were also formed with the lipase from candida cylindracea. the mixtures of unesterified enantiomeric substrates, i.e., x-1(3)-o-oct ...19921511492
high resolution analysis of carotenoids in human plasma by high-performance liquid chromatography. 19921435309
modulation of endotoxin-induced monokine release in human monocytes by lipid a partial structures that inhibit binding of 125i-lipopolysaccharide.we have previously shown that the synthetic tetraacyl precursor ia (compound 406, la-14-pp, or lipid iva) was not able to induce the production of tumor necrosis factor, interleukin-1, and interleukin-6 in human monocytes but strongly antagonized lipopolysaccharide (lps)-induced formation of these monokines. this inhibition was detectable at the level of mrna production. to achieve a better understanding of molecular basis of this inhibition, we investigated whether lipid a precursor ia (la-14-p ...19921280625
chromobacterium violaceum septicaemia: the intensive care management of two cases.the first human infection with chromobacterium violaceum was recorded in 1927, but since then there have been about 33 cases reported worldwide, including two from australia. chr. violaceum occurs in the tropics and subtropics and is generally considered to be nonpathogenic, but infection can occur in patients who are immunosuppressed and it has a high mortality rate. this paper presents the intensive care management of two cases of chr. violaceum infection occurring in far north queensland. the ...19921609950
kinetics and stability of a chromobacterium viscosum lipase in reversed micellar and aqueous media.the lipolytic activity of chromobacterium viscosum lipase b (ec 3.1.1.3.; triacylglycerol hydrolase) solubilized both in water and aot/isooctane reversed micelles has been investigated using triolein as a substrate. the influence of relevant parameters in the catalytic activity such as temperature, ph, surfactant and substrate concentrations, and water content was tested and compared in both media. a study of stability of the lipase was carried out, with particular reference to the influence of ...19921368011
bacterial chemistry. vi. biological activities and cytotoxicity of 1,3-dihydro-2h-indol-2-one derivatives.the biosynthetic pigment from chromobacterium violaceum bb-78, 1,3-dihydro-2h-indol-2-one and its derivatives exhibit biological activities such as antimicrobial action, low hemolytic effects on red blood cells and in vitro trypanocide activity. a relatively high cytotoxicity on v-79 hamster fibroblast cells of the biosynthetic pigment was found, although with the methylol derivative the toxicity was almost eliminated. the methylol derivative exhibited similar toxicity as nifurtimox, a known, co ...19921341576
metabolites formed during anaerobic transformation of toluene and o-xylene and their proposed relationship to the initial steps of toluene mineralization.strain t1 is a facultative bacterium that is capable of anaerobic toluene degradation under denitrifying conditions. while 80% of the carbon from toluene is either oxidized to carbon dioxide or assimilated into cellular carbon, a significant portion of the remainder is transformed into two dead-end metabolites. these metabolites were produced simultaneous to the mineralization of toluene and were identified as benzylsuccinic acid and benzylfumaric acid. identification was based on comparison of ...19921610173
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
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
[chromobacterium violaceum, opportunist pathogenic bacteria in tropical and subtropical regions].chromobacterium violaceum is isolated from soil and waters in tropical and subtropical areas. this gram negative bacillus is considered as a saprophyte, but occasionally it can act as an opportunistic pathogen for animals and man, and cause fatal septicaemia from skin lesion with many liver and lung abscesses. classification, nomenclature, media used to isolation, characters useful to identification (morphology, cultural and biochemical traits, violacein pigmentation), differentiation from relat ...19938219788
identification of the intersubunit binding region in rat tyrosine hydroxylase.limited proteolysis converts the 39200 molecular weight catalytic domain of rat tyrosine hydroxylase to a monomer with a molecular weight of 37600. the purified monomer is almost fully active, with minor changes in kinetic parameters at ph 7. mass spectral analysis and n-terminal sequencing of the proteolytically generated species establish that 20 amino acids have been removed from the carboxyl terminus and five from the amino terminus. based on these results, the carboxyl terminus is responsib ...19937904160
[the antagonistic activity of the bacterial flora in feed in relation to the causative agent of diarrhea in calves].antagonistic activity of 264 strains (6 species) of aerobic bacilli as well as 45 strains (3 species) of bacteria from genera chromobacterium and pseudomonas has been studied. they were isolated from the fodder at the farms of ukraine five regions in 1986-1992 in respect to 128 strains (17 species) of genera escherichia, proteus, salmonella, shigella and pasteurella, isolated by the authors from feces of calf with symptoms of diarrhea. high antagonistic activity of bacillus polymyxa 168 (zone of ...19938025695
a re-examination of the metal requirement of chromobacterium violaceum phenylalanine hydroxylase. 19938304197
histidines 138 and 143 are copper binding ligands in chromobacterium violaceum phenylalanine hydroxylase. 19938304204
phylogenetic position of taylorella equigenitalis determined by analysis of amplified 16s ribosomal dna sequences.the 16s ribosomal dna sequence of taylorella equigenitalis (formerly haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. a phylogenetic analysis of this sequence revealed a phylogenetic position of t. equigenitalis in the beta subclass of the class proteobacteria apart from the position of haemophilus influenzae, which belongs to the gamma subclass of proteobacteria. a close phylogenetic relationship among t. equigenitalis, alcaligenes xylosoxidans, ...19938347520
nonfatal and fatal infections caused by chromobacterium violaceum.human infection caused by chromobacterium violaceum is rare, but when it occurs it is associated with a high mortality rate. we report the cases of two patients with infection due to chromobacterium violaceum. one patient presented early in the course of disease and survived after receiving appropriate antibiotic therapy. the other patient presented late in the course of disease and died of fulminant sepsis with abscesses in multiple organs. we discuss the similarity between c. violaceum infecti ...19938218697
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
an ultrafiltration membrane bioreactor for the lipolysis of olive oil in reversed micellar media.the enzymatic hydrolysis of olive oil using chromobacterium viscosum lipase b encapsulated in reversed micelles of dioctyl sodium sulfosuccinate (aot) in isooctane was investigated in an ultrafiltration ceramic membrane reactor of tubular type, operating in a batch mode. water concentration was found to be a critical parameter in the enzyme kinetics and hydrolysis yield of the reaction. the size of micelles, recirculation rate, and substrate concentration were found to be the major factors affec ...199318609620
modeling lipolysis in a reversed micellar system: part i. conventional batch reactor.triglyceride hydrolysis using chromobacterium viscosum lipase b in a reversed micellar media was investigated in a batch-type reactor. the dynamic evolution of the product concentration was analyzed using several mechanistic models, both from the literature and developed in this work. a kinetic model with nonlinear product inhibition was found to be the most adequate for the description of batch hydrolysis data over an extensive range of time and substrate concentration. the obtained rate equati ...199318613109
modeling lipolysis in a reversed micellar system: part ii-membrane reactor.olive oil hydrolysis using chromobacterium viscosum lipase b in a reversed micellar media was investigated in a membrane reactor. the dynamic evolution of the product concentration both in the concentrate and permeate stream was analyzed using a mechanistic model previously developed by us and further modified in this work. a kinetic law with a second-order dependence in the substrate concentration and nonlinear product inhibition was found to be the most adequate for the description of the hydr ...199318613110
crystallization and preliminary x-ray analysis of a lipase from chromobacterium viscosum.lipase from chromobacterium viscosum has been purified to homogeneity and crystallized in a form suitable for x-ray diffraction analysis from 10-14% polyethylene glycol 4000 and 10-14% 2-methyl-2,4-pentane diol at ph 6.4 in the presence of 0.25%(w/v) n-octyl-beta-d-glucopyranoside. these crystals belong to space group p2(1)2(1)2 with refined lattice constants a = 41.1 a, b= 156.8, c = 43.6 a, indicating a cell content of one monomer per asymmetric unit of the crystal. the crystals diffract to a ...199415299463
chromobacterium violaceum septicaemia in malaysia. 19947899912
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
fr901228, a novel antitumor bicyclic depsipeptide produced by chromobacterium violaceum no. 968. ii. structure determination. 19948175483
fr901228, a novel antitumor bicyclic depsipeptide produced by chromobacterium violaceum no. 968. iii. antitumor activities on experimental tumors in mice.the antitumor activities of fr901228, (e)-(1s,4s,10s,21r)-7-[(z)- ethylidene]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23- tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,19,22-pentanone, isolated from chromobacterium violaceum no. 968, were studied in animals. fr901228 (ip) prolonged the life of mice bearing such murine ascitic tumors as p388 and l1210 leukemias and b16 melanoma, and inhibited (iv) the growth of murine solid tumors (colon 38 carcinoma, m5076 reticulum cell sarcoma and meth a fibro ...19948175484
molecular structures that influence the immunomodulatory properties of the lipid a and inner core region oligosaccharides of bacterial lipopolysaccharides.the relationship between chain length as well as the position of fatty acyl groups to the ability of lipid a to abolish the expression of suppressor t-cell (ts) activity was examined. fatty acyl chain lengths of c12 to c14, as in the lipid a of escherichia coli and salmonella minnesota, appear to be optimal for this bioactivity, since lipid a preparations with fatty acyl groups of relatively short chain length (c10 to c12 for pseudomonas aeruginosa and chromobacterium violaceum) or predominantly ...19948188347
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
action of fr901228, a novel antitumor bicyclic depsipeptide produced by chromobacterium violaceum no. 968, on ha-ras transformed nih3t3 cells.fr901228, a novel antitumor antibiotic, reversed the transformed morphology of the ha-ras transformants, ras-1 cells, and inhibited their growth. the reduction of c-myc expression was observed in fr901228-treated ras-1 cells by rna dot-blot hybridization. this reduction of c-myc expression and morphological reversion of the transformed cells to normal were correlated with growth inhibition (g0/g1 arrest in cell cycle).19947765477
the structure of the o-specific polysaccharide of the lipopolysaccharide from chromobacterium violaceum nctc 9694. 19947528643
fr901228, a novel antitumor bicyclic depsipeptide produced by chromobacterium violaceum no. 968. i. taxonomy, fermentation, isolation, physico-chemical and biological properties, and antitumor activity.a novel antitumor bicyclic depsipeptide, fr901228, was isolated from a broth culture of chromobacterium violaceum no. 968 as colorless prisms and the molecular formula was determined as c24h36n4o6s2. this antibiotic reverted the transformed morphology of a ha-ras transformant to normal, and exhibited prominent antitumor activities against murine and human tumor cell lines both in vitro and in vivo.19947513682
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
third generation cephalosporin-resistant gram-negative bacilli in the feces of hospitalized children.in 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
preparative-scale kinetic resolutions catalysed by microbial lipases immobilised in aot-stabilised microemulsion-based organogels: cryoenzymology as a tool for improving enantioselectivity.gelatin-containing microemulsion based organogels have been used as an immobilisation matrix for lipases from a number of different sources. kinetic resolutions of octan-3-ol, 1-octen-3-ol and 1-octyn-3-ol by esterification with decanoic acid have been performed using chromobacterium viscosum (cv) lipase. cv lipase is highly enantioselective in favour of the (r)-(-) isomer of octan-3-ol, but the enantioselectivity is both reversed and decreased by the introduction of unsaturation at the 1-positi ...19957492618
inversion of lipase stereospecificity for fluorogenic alkyldiacyl glycerols. effect of substrate solubilization.we synthesized enantiomeric 1-o-alkyl-2,3-diacyl-sn-glycerol and 3-o-alkyl-1,2-diacyl-sn-glycerol containing pyrene as a fluorescent reporter and the trinitrophenylamino residue as a fluorescence quencher; both reporter groups were covalently bound to the omega end of the acyl chains at positions sn-2 and sn-3(1), respectively. the fluorescence of the intact substrate molecules was very low. chemical or enzymic release of the fatty acyl chains lead to fluorescence dequenching. the rate of lipoly ...19957628484
macrocyclic lactone synthesis by lipases in water-in-oil microemulsions.five microbial lipases from chromobacterium viscosum, candida cylindracea, pseudomonas (source fluka), pseudomonas (source genzyme) and lipoprotein lipase ex microbial (genzyme) have been screened for lactonisation activity towards 16-hydroxyhexadecanoic acid (hha) in a variety of different w/o microemulsion systems. with the exception of candida cylindracea (cc), all the lipases exhibited lactonisation activity although they were inherently more active in microemulsion systems based on the anio ...19957544159
taxonomic study of bacteria isolated from plants: proposal of sphingomonas rosa sp. nov., sphingomonas pruni sp. nov., sphingomonas asaccharolytica sp. nov., and sphingomonas mali sp. nov.the taxonomic positions of 10 strains of 3-ketolactose-forming bacteria which were isolated from the roots of plants (rosa sp., psychotria nairobiensis, ardisia crispa, prunus persica, and apple trees) were investigated. the dna base compositions of these strains ranged from 64.0 to 65.7 mol%, the isoprenoid quinone of each strain was ubiquinone 10, 3-hydroxy fatty acids were lacking in the cellular fatty acids of these organisms, and all of the strains contained a sphingolipid with the long-cha ...19957537068
phylogenetic inferences and taxonomic consequences of 16s ribosomal dna sequence comparison of chromohalobacter marismortui, volcaniella eurihalina, and deleya salina and reclassification of v. eurihalina as halomonas eurihalina comb. nov.the phylogenetic positions of the moderately halophilic bacteria chromohalobacter marismortui, volcaniella eurihalina, and deleya salina were determined by pcr amplification of rrna genes and direct sequencing. the resulting data were compared with data for other bacteria obtained from 16s rrna sequence databases. c. marismortui, v. eurihalina, and d. salina clustered phylogenetically within the gamma subclass of the proteobacteria and are closely related to other species on the halomonas-deleya ...19957547290
l-tryptophan 2',3'-oxidase from chromobacterium violaceum. substrate specificity and mechanistic implications.l-tryptophan 2',3'-oxidase, an amino acid alpha,beta-dehydrogenase isolated from chromobacterium violaceum, catalyzes the formation of a double bond between the c alpha and c beta carbons of various tryptophan derivatives provided that they possess: (i) a l-enantiomeric configuration, (ii) an alpha-carbonyl group, and (iii) an unsubstituted and unmodified indole nucleus. kinetic parameters were evaluated for a series of tryptophan analogues, providing information on the contribution of each chem ...19957559518
stereoselectivity of microbial lipases. the substitution at position sn-2 of triacylglycerol analogs influences the stereoselectivity of different microbial lipases.in the present study, the stereoselectivity of purified lipases from candida rugosa, chromobacterium viscosum, pseudomonas species and rhizopus arrhizus towards triacylglycerols in comparison to various structural analogs were investigated. different triacylglycerol analogs with distinct polarities at position sn-2 of the glycerol backbone (1,3-diacyl-2-x-glycerol, where 2-x = 2-acyloxy, 2-alkyloxy, 2-deoxy-2-alkyl, or 2-deoxy-2-phenyl) were synthesized. substrate hydrophobicity and steric requi ...19957851405
lipase from chromobacterium viscosum: biochemical characterization indicating homology to the lipase from pseudomonas glumae.previous purification of a commercial lipolytic preparation from chromobacterium viscosum using gel filtration chromatography yielded two enzymatically active fractions, named lipases a and b. characterization of these fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that lipase a consisted of a high molecular weight aggregate of lipase protein with lipopolysaccharides. this complex could be dissociated by treatment with edta-tris buffer containing the non-ionic de ...19957786905
mechanism of metal-independent hydroxylation by chromobacterium violaceum phenylalanine hydroxylase.phenylalanine hydroxylase converts phenylalanine to tyrosine utilizing a tetrahydrobiopterin cofactor. several key mechanistic questions have yet to be resolved, specifically the identity of the hydroxylating species and the role of the non-heme iron which is present in all of the mammalian pahs. recently, we have demonstrated that a bacterial pah from chromobacterium violaceum does not require any redox active metal for activity [carr, r. t., & benkovic, s. j. (1993) biochemistry 32, 14132-1413 ...19957779797
a study of reversibly inactivated lipases for use in a morphine-triggered naltrexone delivery system.a key component of an implant that can be triggered by external morphine to release naltrexone is an inactivated enzyme that can be activated by morphine and which can then rapidly remove a protective coating surrounding a bioerodible polymer containing dispersed naltrexone. in this article we describe a lipase that has been conjugated with o3-carboxymethylmorphine, morphine-beta-3-glucuronide and o3-carboxypropylmorphine. the enzyme conjugate was then inactivated by complexation with affinity-p ...19958582907
effects of sorbitol addition on the action of free and immobilized hydrolytic enzymes in organic media.the effect of the addition of sorbitol on the activity and stability of enzymes was examined by monitoring transesterification reactions performed in organic media at various water activities (a(w) = 0.08 to 0.97). lipases from chromobacterium viscosum and candida rugosa immobilized on celite, and chymotrypsin, free or immobilized on celite, were used. when the sorbitol-containing enzymes were employed, higher reaction rates and less hydrolysis were observed. immobilization of chymotrypsin resul ...199518623233
esterification reactions catalyzed by chromobacterium viscosum lipase in ctab-based microemulsion systems.chromobacterium viscosum (cv) lipase solubilized in water-in-oil (w/o) microemulsions based on the cationic surfactant hexadecyltrimethylammonium bromide (ctab) have been used for multigram-scale ester synthesis, including the kinetic resolution of a secondary alcohol. the stability of cv lipase in all the ctab microemulsions studied was excellent and was superior to that observed in aqueous buffer at the same ph and temperature. kinetic studies were performed using the synthesis of ethylhexadec ...199518623188
hydrolysis and esterification of acylglycerols and analogs in aqueous medium catalyzed by microbial lipases.the stereoselectivity of microbial lipases from chromobacterium viscosum (cvl) and rhizopus arrhizus (ral) towards monoacylglycerols (rac-1(3)-oleoylglycerol and 2-oleoylglycerol), diacylglycerols (1,3-dioleoylglycerol and rac-1,2(2,3)-dioleoylglycerol) and 2-o-ether analogs (rac-1(3)-oleoyl-2-o-hexadecylglycerol and rac-1(3)-octanoyl-2-o-hexadecylglycerol) was determined. the results of the hydrolysis of 2-o-ether analogs confirmed the importance of the substituent at c-2 of acylglycerols in th ...19968652651
acute pleuropneumonia in barbary sheep (amnotragus lervia) associated with chromobacterium violaceum. 19968736506
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
isolation and identification of poly(3-hydroxyvalerate)-degrading strains of pseudomonas lemoignei.by using selective enrichment of polyhydroxyalkanoate-degrading bacteria and poly(3-hydroxyvalerate)-containing granules from chromobacterium violaceum as the carbon source, 10 new pseudomonas lemoignei strains were isolated; these strains were able to degrade poly(3-hydroxyvalerate), as well as poly(3-hydroxybutyrate), in vitro. the new isolates were characterized and identified by comparing them with p. lemoignei lmg 2207(t) (t = type strain). like p. lemoignei lmg 2207(t) cells, the cells of ...19968782688
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
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
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
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
biocatalysis using gelatin microemulsion-based organogels containing immobilized chromobacterium viscosum lipase.chromobacterium viscosum (cv) lipase was immobilized in gelatin-containing aerosol-ot (aot) microemulsion-based organogels (mbgs). the behavior of this novel, predominantly hydrophobic matrix as an esterification catalyst has been examined. the biocatalyst was most effective when the mbg was granulated to yield gel particles of approximately 500 mum diameter, providing a total surface area of ca. 10(6) mm(2) per 10 cm(3) of gel. the gel was generally contacted with a solution of the substrate(s) ...199718633956
lipase-catalysed resolution of gamma- and delta-lactones.lipase-catalysed stereoselective hydrolysis of a family of saturated gamma- and delta-lactones was investigated. increasing the chain length from delta-octalactone to delta-dodecalactone leads to higher enantiomeric excess. best results were found using a lipase from pseudomonas species (kw51) yielding highest enantiomeric excesses (greater than 99% ee at 50% conversion, e > 100) at short reaction times (10 h) for delta-undecalactone and delta-dodecalactone. in contrast, gamma-lactones were reso ...19979304874
on the inhibition of microbial lipases by tetrahydrolipstatin. 19979309654
chromobacterium violaceum infection of the deep neck tissues in a traveler to thailand. 19979332541
systematic study of the genus vogesella gen. nov. and its type species, vogesella indigofera comb. nov.a blue-pigmented colony that had a metallic copper-colored sheen was isolated in 1973 from a standard spread plate count preparation of oxidation pond sediment. over the next 11 years, an additional 12 strains of blue-pigmented bacteria were isolated from freshwater samples and compared to several reference strains of bacteria. morphological and biochemical tests revealed that these 13 isolates were very similar to [pseudomonas] indigofera atcc 19706t (t = type strain) and atcc 14036. a numerica ...19978995797
the crystal structure of a triacylglycerol lipase from pseudomonas cepacia reveals a highly open conformation in the absence of a bound inhibitor.. lipases, a family of enzymes which catalyze the hydrolysis of triglycerides, are widely distributed in many organisms. true lipases are distinguished from esterases by the characteristic interfacial activation they exhibit at an oil-water interface. lipases are one of the most frequently used biocatalysts for organic reactions performed under mild conditions. their biotechnological applications include food and oil processing and the preparation of chiral intermediates for the synthesis of ena ...19979032073
the open conformation of a pseudomonas lipase.. the interfacial activation of lipases results primarily from conformational changes in the enzymes which expose the active site and provide a hydrophobic surface for interaction with the lipid substrate. comparison of the crystallization conditions used and the structures observed for a variety of lipases suggests that the enzyme conformation is dependent on solution conditions. pseudomonas cepacia lipase (pcl) was crystallized in conditions from which the open, active conformation of the enzy ...19979032074
chemoenzymatic synthesis of chiral biologically active heterocycles.the chemoenzymatic approach to the preparation of some chiral biologically active heterocycles is discussed. synthetic strategies took advantage of enantioselective bioconversion processes carried out on suitable reaction intermediates. reductions of carbonyl compounds catalyzed by different alcohol dehydogenases (tbadh from thermoanaerobium brockii, 20 beta-hsdh from streptomyces hydrogenans, beta-hsdh from pseudomonas testosteroni) allowed the preparation with high enantiomeric purity of the e ...19979274001
kinetic studies of chromobacterium viscosum lipase in aot water in oil microemulsions and gelatin microemulsion-based organogels.kinetic studies have shown that octyl decanoate synthesis by chromobacterium viscosum (cv) lipase in sodium bis-2-(ethylhexyl) sulfosuccinate (aot) water in oil (w/o) microemulsions occurs via the nonsequential (ping-pong) bi bi mechanism. there was evidence of single substrate inhibition by decanoic acid at high concentrations. initial rate data yielded estimates for acid and alcohol michaelis constants of ca. 10(-1) mol dm(-3) and a maximum rate under saturation conditions of ca. 10(-3) mol dm ...199718634134
chromobacterium violaceum in tropical northern australia.chromobacterium violaceum is an unusual cause of infection which may have fatality rates of over 60% when systemic illness occurs. we describe four patients infected with this organism who were successfully treated at royal darwin hospital between 1991 and 1996. in tropical australia, c. violaceum infection should be considered along with melioidosis in patients who present with a septic illness with skin lesions and/or organ abscesses after exposure to soil in the wet season.19989577444
chromobacterium violaceum infection.chromobacterium violaceum infection is confined to the tropical and subtropical areas, with almost all reported cases occurring in the southeast. the most common feature of this infection is sepsis, followed by cutaneous involvement and liver abscesses. treatment consists of surgical drainage of purulent collections and appropriate antimicrobial therapy, such as chloramphenicol, gentamicin, imipenem, trimethoprim-sulfamethoxazole, or ciprofloxacin. although c violaceum infection is rare, it is p ...19989598856
chitinolytic activity in chromobacterium violaceum: substrate analysis and regulation by quorum sensing.quorum sensing control mediated by n-acyl homoserine lactone (ahl) signaling molecules has been established as a key feature of the regulation of exoenzyme production in many gram-negative bacteria. in chromobacterium violaceum atcc 31532 a number of phenotypic characteristics, including production of the purple pigment violacein, hydrogen cyanide, antibiotics, and exoproteases are known to be regulated by the endogenous ahl n-hexanoyl-l-homoserine lactone (hhl). in this study we show that c. vi ...19989721280
potential misidentification of burkholderia pseudomallei by api 20ne.biochemical confirmation of the identity of burkholderia pseudomallei in singapore previously relied on the api 20ne panel of tests. after introducing an alternative proprietary biochemical panel, the microbact 24e (medvet, adelaide, australia), we noted that the api panel identified some presumptive b. pseudomallei isolates as other species. we therefore compared the performance of the api 20ne against the microbact 24e with 50 distinct clinical isolates of b. pseudomallei, after 24 hours and a ...19989534210
airways microbial flora in copd patients in stable clinical conditions and during exacerbations: a bronchoscopic investigation.patients affected with chronic obstructive pulmonary disease (copd) undergo frequent exacerbations of their illness characterized by increased cough and expectoration. the precise aetiology of these episodes often remains unknown. in the absence of clinical or radiographic signs of pneumonia, bacterial or viral cultures of sputum usually provide little useful information. thus, we performed fibreoptic bronchoscopy using a protected specimen brush (psb) to obtain uncontaminated secretions for cul ...19989785808
production of acyl-homoserine lactone quorum-sensing signals by gram-negative plant-associated bacteria.many gram-negative bacteria regulate expression of specialized gene sets in response to population density. this regulatory mechanism, called autoinduction or quorum-sensing, is based on the production by the bacteria of a small, diffusible signal molecule called the autoinducer. in the most well-studied systems the autoinducers are n-acylated derivatives of l-homoserine lactone (acyl-hsl). signal specificity is conferred by the length, and the nature of the substitution at c-3, of the acyl side ...19989805399
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