Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| an fad-dependent pyridine nucleotide-disulfide oxidoreductase is involved in disulfide bond formation in fk228 anticancer depsipeptide. | disulfide bonds are rare in bacterial natural products, and the mechanism of disulfide bond formation in those products is unknown. here we characterize a gene and its product critical for a disulfide bond formation in fk228 anticancer depsipeptide in chromobacterium violaceum. deletion of deph drastically reduced fk228 production, whereas complementation of the deph-deletion mutant with a copy of deph on a medium copy-number plasmid not only fully restored the fk228 production but also signific ... | 2009 | 19549597 |
| characteristics and biotechnological applications of microbial cholesterol oxidases. | microbial cholesterol oxidase is an enzyme of great commercial value, widely employed by laboratories routinely devoted to the determination of cholesterol concentrations in serum, other clinical samples, and food. in addition, the enzyme has potential applications as a biocatalyst which can be used as an insecticide and for the bioconversion of a number of sterols and non-steroidal alcohols. the enzyme has several biological roles, which are implicated in the cholesterol metabolism, the bacteri ... | 2009 | 19495743 |
| structural basis for the erythro-stereospecificity of the l-arginine oxygenase vioc in viomycin biosynthesis. | the nonheme iron oxygenase vioc from streptomyces vinaceus catalyzes fe(ii)-dependent and alpha-ketoglutarate-dependent cbeta-hydroxylation of l-arginine during the biosynthesis of the tuberactinomycin antibiotic viomycin. crystal structures of vioc were determined in complexes with the cofactor fe(ii), the substrate l-arginine, the product (2s,3s)-hydroxyarginine and the coproduct succinate at 1.1-1.3 a resolution. the overall structure reveals a beta-helix core fold with two additional helical ... | 2009 | 19490124 |
| the origin of the electrostatic perturbation in acetoacetate decarboxylase. | acetoacetate decarboxylase (aadase) has long been cited as the prototypical example of the marked shifts in the pk(a) values of ionizable groups that can occur in an enzyme active site. in 1966, it was hypothesized that in aadase the origin of the large pk(a) perturbation (-4.5 log units) observed in the nucleophilic lys 115 results from the proximity of lys 116, marking the first proposal of microenvironment effects in enzymology. the electrostatic perturbation hypothesis has been demonstrated ... | 2009 | 19458715 |
| a probable aculeacin a acylase from the ralstonia solanacearum gmi1000 is n-acyl-homoserine lactone acylase with quorum-quenching activity. | the infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by n-acylhomoserine lactones (ahls) acting as signal molecules. ahl-acylase is a quorum quenching enzyme and degrades ahls by removing the fatty acid side chain from the homoserine lactone ring of ahls. this blocks ahl accumulation and pathogenic phenotypes in quorum sensing bacteria. | 2009 | 19426552 |
| oxidative dna damage protective activity, antioxidant and anti-quorum sensing potentials of moringa oleifera. | the aqueous extract of leaf (le), fruit (fe) and seed (se) of moringa oleifera was assessed to examine the ability to inhibit the oxidative dna damage, antioxidant and anti-quorum sensing (qs) potentials. it was found that these extracts could significantly inhibit the oh-dependent damage of puc18 plasmid dna and also inhibit synergistically with trolox, with an activity sequence of le > fe > se. hplc and ms/ms analysis was carried out, which showed the presence of gallic acid, chlorogenic acid, ... | 2009 | 19425184 |
| recurrent chromobacterium violaceum infection in a patient with chronic granulomatous disease. | we report a rare case of recurrent infection of chromobacterium violaceum in an immunocompromised patient. despite the high mortality rate associated with this infection as reported in the literature, this patient survived three episodes of recurrent infection. we believe that with high clinical suspicion, prompt treatment and appropriate antimicrobial agents, it is possible for clinicians to treat this infection effectively and reduce the mortality rate. | 2008 | 19385503 |
| comparative metagenomics of daphnia symbionts. | shotgun sequences of dna extracts from whole organisms allow a comprehensive assessment of possible symbionts. the current project makes use of four shotgun datasets from three species of the planktonic freshwater crustaceans daphnia: one dataset from clones of d. pulex and d. pulicaria and two datasets from one clone of d. magna. we analyzed these datasets with three aims: first, we search for bacterial symbionts, which are present in all three species. second, we search for evidence for cyanob ... | 2009 | 19383155 |
| chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | chromobacterium violaceum infection is uncommon but potentially fatal, with a clinical picture similar to melioidosis but with different antibiotic sensitivities and treatment. this infection can involve any organ, but we believe this is the first reported case of c. violaceum endocarditis. | 2009 | 19351314 |
| violacein extracted from chromobacterium violaceum inhibits plasmodium growth in vitro and in vivo. | violacein is a violet pigment extracted from the gram-negative bacterium chromobacterium violaceum. it presents bactericidal, tumoricidal, trypanocidal, and antileishmanial activities. we show that micromolar concentrations efficiently killed chloroquine-sensitive and -resistant plasmodium falciparum strains in vitro; inhibited parasitemia in vivo, even after parasite establishment; and protected plasmodium chabaudi chabaudi-infected mice from a lethal challenge. | 2009 | 19273690 |
| is gas-discharge plasma a new solution to the old problem of biofilm inactivation? | conventional disinfection and sterilization methods are often ineffective with biofilms, which are ubiquitous, hard-to-destroy microbial communities embedded in a matrix mostly composed of exopolysaccharides. the use of gas-discharge plasmas represents an alternative method, since plasmas contain a mixture of charged particles, chemically reactive species and uv radiation, whose decontamination potential for free-living, planktonic micro-organisms is well established. in this study, biofilms wer ... | 2009 | 19246743 |
| species distribution and antimicrobial susceptibility of gram-negative aerobic bacteria in hospitalized cancer patients. | nosocomial infections pose significant threats to hospitalized patients, especially the immunocompromised ones, such as cancer patients. | 2009 | 19228413 |
| chromobacterium violaceum infection in a provincial hospital in sri lanka. | 2008 | 19189802 | |
| enhanced production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer with manipulated variables and its properties. | cupriavidus sp. usmaa1020, a local isolate was able to biosynthesis poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [p(3hb-co-4hb)] copolymer with various 4hb precursors as the sole carbon source. manipulation of the culture conditions such as cell concentration, phosphate ratio and culture aeration significantly affected the synthesis of p(3hb-co-4hb) copolymer and 4hb composition. p(3hb-co-4hb) copolymer with 4hb compositions ranging from 23 to 75 mol% 4hb with various mechanical and thermal prop ... | 2009 | 19189144 |
| septicemia in a neonatal calf associated with chromobacterium violaceum. | chromobacterium violaceum infections are highly fatal and rarely reported in domestic animals. this report describes a fatal case of c. violaceum septicemia in a 7-day-old female beef calf. the calf had necrosuppurative omphalophlebitis, necrotizing interstitial pneumonia, necrosuppurative hepatitis and splenitis, anterior uveitis with hypopyon, suppurative polyarthritis, and disseminated hemorrhagic meningitis with multifocal necrotizing encephalitis. histologically, clusters of gram-negative b ... | 2009 | 19112118 |
| secondary metabolites produced by the marine bacterium halobacillus salinus that inhibit quorum sensing-controlled phenotypes in gram-negative bacteria. | certain bacteria use cell-to-cell chemical communication to coordinate community-wide phenotypic expression, including swarming motility, antibiotic biosynthesis, and biofilm production. here we present a marine gram-positive bacterium that secretes secondary metabolites capable of quenching quorum sensing-controlled behaviors in several gram-negative reporter strains. isolate c42, a halobacillus salinus strain obtained from a sea grass sample, inhibits bioluminescence production by vibrio harve ... | 2009 | 19060172 |
| diversity of chromobacterium violaceum isolates from aquatic environments of state of pará, brazilian amazon. | the present study intended to characterize the phenotypic and genetic diversity of brazilian isolates of chromobacterium violaceum from aquatic environments within the amazon region. nineteen isolates showed morphological properties of c. violaceum and the majority grew at 44 degrees c. low temperatures, in contrast, showed to be inhibitory to their growth, as eleven isolates did not grow at 10 degrees c and nine did not produce pigmentation, clearly indicating an inhibition of their metabolism. ... | 2008 | 19057818 |
| cloning, sequence analysis, and expression of a gene encoding chromobacterium sp. ds-1 cholesterol oxidase. | chromobacterium sp. strain ds-1 produces an extracellular cholesterol oxidase that is very stable at high temperatures and in the presence of organic solvents and detergents. in this study, we cloned and sequenced the structural gene encoding the cholesterol oxidase. the primary translation product was predicted to be 584 amino acid residues. the mature product is composed of 540 amino acid residues. the amino acid sequence of the product showed significant similarity (53-62%) to the cholesterol ... | 2009 | 19015844 |
| anthranilate synthase subunit organization in chromobacterium violaceum. | tryptophan is an aromatic amino acid used for protein synthesis and cellular growth. chromobacterium violaceum atcc 12472 uses two tryptophan molecules to synthesize violacein, a secondary metabolite of pharmacological interest. the genome analysis of this bacterium revealed that the genes trpa-f and paba-b encode the enzymes of the tryptophan pathway in which the first reaction is the conversion of chorismate to anthranilate by anthranilate synthase (as), an enzyme complex. in the present study ... | 2008 | 18949702 |
| amphibian chemical defense: antifungal metabolites of the microsymbiont janthinobacterium lividum on the salamander plethodon cinereus. | disease has spurred declines in global amphibian populations. in particular, the fungal pathogen batrachochytrium dendrobatidis has decimated amphibian diversity in some areas unaffected by habitat loss. however, there is little evidence to explain how some amphibian species persist despite infection or even clear the pathogen beyond detection. one hypothesis is that certain bacterial symbionts on the skin of amphibians inhibit the growth of the pathogen. an antifungal strain of janthinobacteriu ... | 2008 | 18949519 |
| pseudogulbenkiania subflava gen. nov., sp. nov., isolated from a cold spring. | a yellow-coloured bacterial strain, designated bp-5(t), was isolated from a water sample of a cold spring located in the hsinchu area of northern taiwan. cells of the strain were gram-negative, non-spore-forming rods with a polar flagellum. the isolate was able to grow at 15-42 degrees c, 0-1 % nacl and ph 6-8. the predominant fatty acids were summed feature 3 (c(16 : 1)omega7c and/or iso-c(15 : 0) 2-oh), c(16 : 0) and c(18 : 1)omega7c. the major respiratory quinone was ubiquinone 8. the dna g+c ... | 2008 | 18842860 |
| cellulose biosynthesis by the beta-proteobacterium, chromobacterium violaceum. | the chromobacterium violaceum atcc 12472 genome was sequenced by the brazilian national genome project consortium. previous annotation reported the presence of cellulose biosynthesis genes in that genome. analysis of these genes showed that, as observed in other bacteria, they are organized in two operons. in the present work, experimental evidences of the presence of cellulose in the extracellular matrix of the biofilm produced by c. violaceum in static cultures are shown. biofilm samples were ... | 2008 | 18820969 |
| kinetic isotope effects on aromatic and benzylic hydroxylation by chromobacterium violaceum phenylalanine hydroxylase as probes of chemical mechanism and reactivity. | phenylalanine hydroxylase from chromobacterium violaceum (cvpheh) is a non-heme iron monooxygenase that catalyzes the hydroxylation of phenylalanine to tyrosine. in this study, we used deuterium kinetic isotope effects to probe the chemical mechanisms of aromatic and benzylic hydroxylation to compare the reactivities of bacterial and eukaryotic aromatic amino acid hydroxylases. the (d) k cat value for the reaction of cvpheh with [(2)h 5]phenylalanine is 1.2 with 6-methyltetrahydropterin and 1.4 ... | 2008 | 18817418 |
| successful treatment of chromobacterium violaceum sepsis in south africa. | chromobacterium violaceum sepsis is extremely rare and usually fatal. a very few cases of c. violaceum infection have been reported from africa, but never from south africa. as far as could be ascertained, this infection has never been reported in a patient with leukaemia. we describe what we believe to be the first such case of c. violaceum sepsis, in a 16-year-old female patient with acute biphenotypic leukaemia, which developed during the neutropenic phase after intensive chemotherapy. the in ... | 2008 | 18809561 |
| fatal wound infection caused by chromobacterium violaceum in ho chi minh city, vietnam. | chromobacterium violaceum is a proteobacterium found in soil and water in tropical regions which rarely causes infection in humans. here, we report a fatal bacteremia caused by chromobacterium violaceum in vietnam. we describe a number of clinical, microbiological, and molecular aspects associated with this bacterial infection. | 2008 | 18799697 |
| polyhydroxyalkanoate (pha) production using waste vegetable oil by pseudomonas sp. strain dr2. | to produce polyhydroxyalkanoate (pha) from inexpensive substrates by bacteria, vegetable-oil-degrading bacteria were isolated from a rice field using enrichment cultivation. the isolated pseudomonas sp. strain dr2 showed clear orange or red spots of accumulated pha granules when grown on phosphate and nitrogen limited medium containing vegetable oil as the sole carbon source and stained with nile blue a. up to 37.34% (w/w) of intracellular pha was produced from corn oil, which consisted of three ... | 2008 | 18756101 |
| antibacterial activity of halogenated sesquiterpenes from malaysian laurencia spp. | during our studies on malaysian laurencia species, brominated metabolites, tiomanene, acetylmajapolene b, and acetylmajapolene a were isolated from an unrecorded species collected at pulau tioman, pahang along with known majapolene b and majapolene a. acetylmajapolene a was a mixture of diastereomers as in the case of majapolene a. tiomanene may be a plausible precursor for acetylmajapolenes b and a. in addition, three known halogenated sesquiterpenes and two known halogenated c(15) acetogenins ... | 2008 | 18718619 |
| inhibition of bacterial quorum sensing-regulated behaviors by tremella fuciformis extract. | quorum sensing (qs), or the control of gene expression in response to cell density, is used by both gram-negative and gram-positive bacteria to regulate a variety of physiological functions. increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested tremella fuciformis for their ability to inhibit qs-regulated behaviors. t. fuciformis fruiting bodies were dried and extracted using 75% (v/v) aqueous methanol. the crude extract was redissolved in a ... | 2008 | 18661179 |
| rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae. | microorganisms compete for nutrients and living space in the gut of plant-feeding insect larvae, such as spodoptera spp. their physiological activities and their organization are generally controlled or synchronised by "autoinducers", such as n-acylhomoserinelactones (ahls). due to the strongly alkaline milieu in the insect gut, the lactone ring of ahls is rapidly and spontaneously opened. further degradation to the inactive components homoserine and the acyl moiety is then achieved by a microbi ... | 2008 | 18642255 |
| 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 ... | 1997 | 18634134 |
| 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) ... | 1997 | 18633956 |
| 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 ... | 1995 | 18623233 |
| 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 ... | 1995 | 18623188 |
| 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 ... | 1993 | 18613110 |
| 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 ... | 1993 | 18613109 |
| 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 ... | 1993 | 18609620 |
| 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 ... | 1991 | 18600731 |
| 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 ... | 1991 | 18600711 |
| 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. | 1988 | 18584594 |
| human chromobacterium violaceum infection in southeast asia: case reports and literature review. | chromobacterium violaceum infection in humans is a rare tropical and subtropical disease. the awareness of this organism is limited in spite its ubiquitous distribution. several cases have been reported from southeast asia. a localized infection followed by an overwhelming septicemia and metastatic lesions is the usual pattern of this illness. optimal antimicrobial treatment and duration are unknown. consequently, the outcome is usually fatal. the study reported two patients who suffered from fu ... | 2008 | 18564684 |
| the 1.25 a resolution structure of phosphoribosyl-atp pyrophosphohydrolase from mycobacterium tuberculosis. | phosphoribosyl-atp pyrophosphohydrolase is the second enzyme in the histidine-biosynthetic pathway, irreversibly hydrolyzing phosphoribosyl-atp to phosphoribosyl-amp and pyrophosphate. it is encoded by the hise gene, which is present as a separate gene in many bacteria and archaea but is fused to hisi in other bacteria, fungi and plants. because of its essentiality for growth in vitro, hise is a potential drug target for tuberculosis. the crystal structures of two native (uncomplexed) forms of h ... | 2008 | 18560150 |
| chromobacterium haemolyticum sp. nov., a strongly haemolytic species. | a gram-negative bacterium, strain mda0585(t), isolated from a sputum culture, was characterized by a polyphasic approach. the 16s rrna gene and a conserved portion of the dna gyrase a gene were sequenced and analysed phylogenetically. strain mda0585(t) showed the closest relationships with chromobacterium violaceum atcc 12472(t) and chromobacterium subtsugae praa4-1(t) (96.1 % and 96.3 % 16s rrna gene sequence similarity, respectively). the cellular fatty acids of strain mda0585(t) consisted mai ... | 2008 | 18523185 |
| lipases at interfaces: unique interfacial properties as globular proteins. | the adsorption behavior of two globular proteins, lipase from rhizomucor miehei and beta-lactoglobulin, at inert oil/water and air/water interfaces was studied by the pendant drop technique. the kinetics and adsorption isotherms were interpreted for both proteins in different environments. it was found that the adopted mathematical models well describe the adsorption behavior of the proteins at the studied interfaces. one of the main findings is that unique interfacial properties were observed f ... | 2008 | 18512870 |
| purification and characterization of chromobacterium sp. ds-1 cholesterol oxidase with thermal, organic solvent, and detergent tolerance. | a new screening method for 6beta-hydroperoxycholest-4-en-3-one (hceo)-forming cholesterol oxidase was devised in this study. as the result of the screening, a novel cholesterol oxidase producer (strain ds-1) was isolated and identified as chromobacterium sp. extracellular cholesterol oxidase of strain ds-1 was purified from the culture supernatant. the molecular mass of the purified enzyme was 58 kda. this enzyme showed a visible adsorption spectrum having peaks at 355 and 450 nm, like a typical ... | 2008 | 18512056 |
| hydrogen peroxide linked to lysine oxidase activity facilitates biofilm differentiation and dispersal in several gram-negative bacteria. | the marine bacterium pseudoalteromonas tunicata produces an antibacterial and autolytic protein, alpp, which causes death of a subpopulation of cells during biofilm formation and mediates differentiation, dispersal, and phenotypic variation among dispersal cells. the alpp homologue (loda) in the marine bacterium marinomonas mediterranea was recently identified as a lysine oxidase which mediates cell death through the production of hydrogen peroxide. here we show that alpp in p. tunicata also act ... | 2008 | 18502869 |
| neonatal septicaemia in calabar, nigeria. | a three-year survey of neonatal septicaemia (363 bacteriologically proven cases) in the university of calabar teaching hospital, calabar, has demonstrated that the dominant blood isolate was staphylococcus aureus (53%) followed by unclassified coliforms (20%), an unexpected chromobacterium violaceum (5%). the incidence of neonatal septicaemia was 54.9 per 1000 live births for inborn infants. the predominant organisms were largely susceptible to gentamicin, ceftriazone and cefuroxime with a morta ... | 2008 | 18453516 |
| chromobacterium violaceum cellulitis and sepsis following cutaneous marine trauma. | chromobacterium violaceum is a gram-negative bacillary organism that characteristically produces the purple pigment violacein. documented as the cause of clinically relevant human infections in only 35 cases in the united states, c violaceum is particularly seen in patients with a history of cutaneous injury or trauma. we report the case of an 18-year-old woman who was struck by a propeller in a boating accident and sustained multiple deep lacerations of her right lower extremity. shortly after ... | 2008 | 18441852 |
| kinetics of thermal unfolding of phenylalanine hydroxylase variants containing different metal cofactors (feii, coii, and znii) and their isokinetic relationship. | the kinetics of thermal unfolding of apo- and holo-chromobacterium violaceum phenylalanine hydroxylase (cpah) was investigated using circular dichroism (cd) over the temperature range 44-76 degrees c. in addition to the native cofactor (feii), the unfolding kinetics of holo-cpah was characterized using znii and coii as cofactors. kinetic profiles for apo- and holo-cpah showed a single-phase exponential rise in the cd signal at lambda=222 nm and a first-order dependence on protein concentration. ... | 2008 | 18433092 |
| ppsy: a vector for the stable cloning and expression of streptomycete single gene phenotypes in escherichia coli. | ppsy is a 12kb cloning vector derived from the incw plasmid r388, which provides a rapid and easy way to stably clone phenotypes encoded in dna segments <10kb. in the present study three different genes were amplified by pcr, cloned into pgem-t easy and sub-cloned into the ecori site of ppsy. the first gene, vioa, is a fad-dependent l-tryptophan amino acid oxygenase from the high g+c gram-negative bacterium chromobacterium violaceum. vioa is involved in the synthesis of the indolocarbazole antit ... | 2008 | 18406459 |
| degradation of n-acyl homoserine lactone quorum sensing signal molecules by forest root-associated fungi. | a collection of mycorrhizal and nonmycorrhizal root-associated fungi coming from forest environments was screened for their ability to degrade n-acyl homoserine lactones (ahl) or to prevent ahl recognition by producing quorum sensing inhibitors (qsi). no production of qs-inhibitors or -activators was detected using the two biosensors chromobacterium violaceum cv026 and agrobacterium tumefaciens in the culture supernatant of these fungi. however, the ability to degrade c6- and 3o,c6-hsl was detec ... | 2008 | 18400006 |
| chromobacterium aquaticum sp. nov., isolated from spring water samples. | strain cc-seya-1t, a motile, gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from yang-ming mountain, taipei county, taiwan. 16s rrna gene sequence studies showed that the strain clustered with chromobacterium violaceum (96.8 % similarity) and chromobacterium subtsugae (96.5 % similarity), followed by aquitalea magnusonii (95.8 % similarity). the fatty acid profile was slightly different from those reported for c. violaceum, c. sub ... | 2008 | 18398186 |
| gene expression of the arsenic resistance operon in chromobacterium violaceum atcc 12472. | chromobacterium violaceum atcc 12472 presents an arsrcb-type operon, which is involved in arsenic resistance. the regulating protein of this resistance system (arsr) does not have the small conserved site (elcvdcl) to link to the metalloid, as observed in escherichia coli, and is thus considered to be an atypical arsr protein, like that observed in acidithiobacillus ferrooxidans. in the present study, the gene expression profile of the ars operon under induction at different concentrations of ar ... | 2008 | 18388983 |
| prevalence of bacterial pathogens and their anti-microbial resistance in tilapia and their pond water in trinidad. | in trinidad, tilapia (oreonchromis spp.) is one of the most important fresh water food fish and the number of farms has been increasing annually. a study was conducted in the local tilapia industry to determine the microbial quality of pond water, prevalence of bacterial pathogens and their anti-microbial resistance using the disk diffusion method. seventy-five apparently healthy fish and 15 pond water samples from three of the four commercial tilapia fish farms in the country were processed. th ... | 2008 | 18387142 |
| bacteria flora and heavy metals in cultivated oysters crassostrea iredalei of setiu wetland, east coast peninsular malaysia. | slipper oyster crassostrea iredalei is a species of good demand for its sweet flavor and white coloured flesh. the filter feeding nature predisposes oysters to accumulation of pathogenic and heavy metals in waters impacted by sewage pollutions and may thus render the oysters unfit for human consumption. a study was undertaken to investigate the presence of bacteria flora and heavy metal concentrations in cultivated oysters crassostrea iredalei at setiu wetland, terengganu, the only source of cul ... | 2008 | 18369732 |
| diversity in antifungal activity of strains of chromobacterium violaceum from the brazilian amazon. | chromobacterium violaceum is a free-living gram-negative bacterium found in soil and aquatic habitats; abundantly present in the brazilian amazon, it is an important example of exploitable microbial diversity of the tropics. in this study, 24 strains from the brazilian amazon and atcc 12472(t) were investigated for biocontrol potential of seven fungi pathogenic to soybean [glycine max (l.) merril] seed. both cells and the supernatants of two brazilian strains, 07-1 and 27-1, together with atcc 1 ... | 2008 | 18347828 |
| culturable heterotrophic bacteria in seawater and mytilus galloprovincialis from a mediterranean area (northern ionian sea-italy). | although mar piccolo of taranto (ionian sea, italy) is one of the most important mytilus galloprovincialis farming areas, data concerning the natural bacterial microbiota of these mussels and their surrounding environment are still scant. this study was carried out seasonally, throughout a year, to determine culturable heterotrophic bacteria both in the water and mussels samples collected at three sampling sites in the northern ionian sea: s. vito, lido gandoli and lido silvana. culturable heter ... | 2009 | 18301997 |
| [successful treatment of a case with fatal sepsis caused by chromobacterium violaceum]. | 2007 | 18282432 | |
| structure of the pigment of chromobacterium iodinum. | 1948 | 18225130 | |
| structural basis for mannose recognition by a lectin from opportunistic bacteria burkholderia cenocepacia. | chronic colonization of the lungs by opportunist bacteria such as pseudomonas aeruginosa and members of the bcc (burkholderia cepacia complex) is the major cause of morbidity and mortality among cf (cystic fibrosis) patients. pa-iil (lecb gene), a soluble lectin from ps. aeruginosa, has been the subject of much interest because of its very strong affinity for fucose. orthologues have been identified in the opportunist bacteria ralstonia solanacearum, chromobacterium violaceum and burkholderia of ... | 2008 | 18215132 |
| diversity and quorum-sensing signal production of proteobacteria associated with marine sponges. | marine sponges are hosts to diverse and dense bacterial communities and thus provide a potential environment for quorum sensing. quorum sensing, a key factor in cell-cell communication and bacterial colonization of higher animals, might be involved in the symbiotic interactions between bacteria and their sponge hosts. given that marine proteobacteria are known to produce n-acyl homoserine lactone (ahl) signal molecules, we tested the production of ahls by alpha- and gammaproteobacteria isolated ... | 2008 | 18211268 |
| fatal septicaemia due to chromobacterium violaceum. | human infection caused by chromobacterium violaceum is rare but when it occurs, it is associated with a high mortality rate. this is a report of a young adult male who presented as a surgical emergency and succumbed soon after. the most common feature of this infection is sepsis, followed by cutaneous involvement and liver abscesses. chromobacterium infection as a differential in a case of sepsis is important for clinicians to suspect, especially in tropical countries. | 2007 | 18198747 |
| n-acylhomoserine lactone regulates violacein production in chromobacterium violaceum type strain atcc 12472. | in tests, chromobacterium violaceum atcc 12472 produced several n-acyl-l-homoserine lactones (ahls). of these, n-(3-hydroxydecanoyl)-l-homoserine lactone was dominant, and controlled violacein production by quorum sensing. strain vir07, an ahl-deficient mutant, did not produce violacein. violacein production in vir07 was induced by adding long-chain ahls (c10-c16), but was inhibited by adding short-chain ahls (c4-c8). strain vir07 showed the response of violacein production when ahls diffused fr ... | 2008 | 18177311 |
| paludibacterium yongneupense gen. nov., sp. nov., isolated from a wetland, yongneup, in korea. | a cream-coloured bacterial strain, 5yn8-15(t), was isolated from a wetland, yongneup, in the inje region of the republic of korea. the bacterium was facultatively anaerobic, gram-negative, motile with a single polar flagellum and curved-rod-shaped. based on 16s rrna gene sequence analysis, strain 5yn8-15(t) is a member of the betaproteobacteria. closely related taxa were gulbenkiania mobilis e4fc31(t) (94.9% sequence similarity), chromobacterium species (94.1-94.4%), aquitalea magnusonii tro-001 ... | 2008 | 18175708 |
| crystal structure of vioe, a key player in the construction of the molecular skeleton of violacein. | violacein and the indolocarbazoles are naturally occurring bisindole products with various biological activities, including antitumor activity. although these compounds have markedly different molecular skeletons, their biosynthetic pathways share the same intermediate "compound x," which is produced from l-tryptophan via indole-3-pyruvic acid imine. compound x is a short-lived intermediate that is spontaneously converted to chromopyrrolic acid for indolocarbazole biosynthesis, whereas vioe tran ... | 2008 | 18171677 |
| the violacein biosynthetic enzyme vioe shares a fold with lipoprotein transporter proteins. | vioe, an unusual enzyme with no characterized homologues, plays a key role in the biosynthesis of violacein, a purple pigment with antibacterial and cytotoxic properties. without bound cofactors or metals, vioe, from the bacterium chromobacterium violaceum, mediates a 1,2 shift of an indole ring and oxidative chemistry to generate prodeoxyviolacein, a precursor to violacein. our 1.21 a resolution structure of vioe shows that the enzyme shares a core fold previously described for lipoprotein tran ... | 2008 | 18171675 |
| fatal septicemia caused by chromobacterium violaceum in a child from colombia. | a 4-year old child living in colombia presented with a history of fever and severe abdominal pain for four days. the patient developed pneumonia, septic shock, multiple organ failure and died on the fifth day of hospitalization. chromobacterium violaceum was isolated from admission blood cultures and was resistant to ampicillin, cephalosporins, carbapenems and aminoglycosides. | 2007 | 18157408 |
| chemical durability, specular gloss, and transmittance of optical glasses. | 1948 | 18101639 | |
| improved activity of enzymes in mixed cationic reverse micelles with imidazolium-based surfactants. | this work reports the significant enhancement in performance of interfacially active enzymes, chromobacterium viscosum (cv) lipase and horseradish peroxidase (hrp) in mixed reverse micelles of cetyltrimethylammonium bromide (ctab) and imidazolium-based amphiphiles having varying tail lengths. lipase activity in these mixed systems was always higher than that in the individual cationic reverse micelles of ctab or any imidazolium surfactant, highest being observed in the mixed system of ctab (50 m ... | 2008 | 18067868 |
| effect of the pretreatment of lipase with organic solvents on its conformation and activity in reverse micelles. | the activity and conformation of chromobacterium viscosum lipase-pretreated with various organic solvents were investigated. the pretreatment of lipase led to a substantial increase of enzyme activity in aot (sodium bis [2-ethyl -1-hexyl] sulfosuccinate)/isooctane/water reverse micelles. among the organic solvents used, n-hexane was found to be most effective. it was observed that higher hexane content with shorter agitation time and vice versa had almost the same effect on the initial activity ... | 2007 | 18025586 |
| [sepsis caused by pigmented and no pigmented chromobacterium violaceum]. | chromobacterium violaceum sepsis is rare but associated with a high mortality rate. we report a fatal case of c. violaceum sepsis in a 6 years old venezuelan indian boy. clinical manifestations were fever and swelling in the right inguinal region. the initial diagnosis was an appendicular plastron. appendicectomy was performed and during surgery a right psoas abscess was identified that resulted culture positive for pigmented c. violaceum. blood cultures were positive for a pigmented and non pig ... | 2007 | 17989847 |
| a study of natural attenuation processes involved in a microcosm model of a crude oil-impacted wetland sediment in the niger delta. | sediment sample from a previously impacted ochani stream was recreated in four glass chambers (a-d) as microcosms. the aim was to model and compare natural attenuation processes to forced aeration for remediation of a crude oil-impacted ecosystem. the initial hydrocarbon concentration was 90,212 mg/kg of sediment. after 60 days, the natural attenuation processes of photooxidation, evaporation, volatilization and biodegradation accounted for 31.9% of the total hydrocarbon removed while 13% was at ... | 2008 | 17988860 |
| isolation and characterization of two groups of novel marine bacteria producing violacein. | thirteen strains of novel marine bacteria producing a purple pigment were isolated from the pacific coast of japan. they were divided into two groups based on their 16s ribosomal rna gene sequences, and both groups of bacteria belonged to the genus pseudoalteromonas. the uv-visible spectrum of the pigment was identical to those of violacein, a pigment produced by several species of bacteria including chromobacterium violaceum, an opportunistic pathogen. further analysis of the chemical structure ... | 2008 | 17968625 |
| violacein: properties and biological activities. | the violet pigment violacein is an indole derivative, isolated mainly from bacteria of the genus chromobacterium, which exhibits important antitumoral, antimicrobial and antiparasitary properties. furthermore, the formulation of violacein in different polymeric carriers developed so far offers alternative approaches to overcoming physiological barriers and undesirable physicochemical properties in vivo, thus improving its efficacy. | 2007 | 17927569 |
| biosynthesis of violacein: a genuine intermediate, protoviolaceinic acid, produced by vioabde, and insight into vioc function. | a biosynthetic intermediate of violacein produced by the mixed enzymes of vioabde was elucidated to be 5-(5-hydroxy-1h-indol-3-yl)-3-(1h-indol-3-yl)-1h-pyrrole-2-carboxylic acid, named protoviolaceinic acid, indicating that vioc, responsible for the final biosynthetic step, works to oxygenate at the 2-position of the right side indole ring, and that the oxygenation reaction to form the central pyrrolidone core proceeds in a non-enzymatic fashion. | 2007 | 17925955 |
| [chromobacterium violaceum septicemia: first case report in the french west indies]. | we report a fatal case of chromobacterium violaceum septicemia in a 42-year-old farm worker living in the french west indies. the bacteria found in the muddy soil and the stagnant water of tropical and subtropical regions is rarely a source of human infection. | 2007 | 17905550 |
| sepsis by chromobacterium violaceum: first case report from colombia. | chromobacterium violaceum is found in tropical and subtropical regions; it is the only chromobacterium species pathogenic for humans. due to its rare presentation, physicians often ignore the importance of this pathogen. we report a fulminant fatal case of bacteremia in a 38-year-old colombian man. the clinical manifestations were fever, thoracic pain, respiratory failure and death. his condition, from the beginning of clinical diagnosis, went into continuous deterioration, till his death, withi ... | 2007 | 17874003 |
| evaluation of different compounds as quorum sensing inhibitors in pseudomonas aeruginosa. | quorum sensing (qs) controls systems affecting the pathogenicity of many microorganisms; its interruption has an anti-pathogenic effect and can be used in the treatment of bacterial infections. in this study we evaluated qs regulation by pseudomonas aeruginosa strains and qs inhibition (qsi) by different compounds. the inhibitory activity of 3 macrolide and 3 lincosamide drugs, resveratrol, garlic extract and n-acetylcysteine was tested on 4 p. aeruginosa strains isolated from cystic fibrosis (c ... | 2007 | 17855182 |
| bacterial stimulation of sporangium production in phytophthora cinnamomi. | bacteria, notably chromobacterium violaceum, stimulate initiation of production of sporangia by phytophthora cinnamomi, a plant pathogen which does not produce this asexual stage in ordinary agar or liquid culture. | 1965 | 17742598 |
| one step engineering of t7-expression strains for protein production: increasing the host-range of the t7-expression system. | the t7-expression system has been very useful for protein expression in escherichia coli. however, it is often desirable to over-express proteins in species other than e. coli. here, we constructed an inducible broad-host-range t7-expression transposon, which allows simple one-step construction of t7-expression strains in various species, providing the option to over-express proteins of interest in a broader host-range. this transposon contains the t7 rna polymerase driven by the lacuv5 promoter ... | 2007 | 17716915 |
| multidrug resistant chromobacterium violaceum: an unusual bacterium causing long standing wound abscess. | 2003 | 17643028 | |
| chromobacterium violaceum infection in taiwan: a case report and literature review. | chromobacterium violaceum is a facultative anaerobic, gram-negative bacillus which inhabits stagnant water in tropical and subtropical regions. we describe the case of an 80-year-old female patient with c. violaceum bacteremia due to traumatic wound infected by contaminated water and soil. she had persistent fever, hypotension and neutrophilic leukocytosis on admission. two sets of blood cultures yielded c. violaceum. the patient was successfully treated with levofloxacin. since the first case f ... | 2007 | 17639170 |
| toxicity of chromobacterium subtsugae to southern green stink bug (heteroptera: pentatomidae) and corn rootworm (coleoptera: chrysomelidae). | diabrotica spp. (coleoptera: chrysomelidae) beetles and southern green stink bugs, nezara viridula (l.) (heteroptera: pentatomidae), are pests on corn, zea mays l., and soybean, glycine max (l.) merr., as well as on cucurbits. control of these insects has depended on chemicals. an alternative to chemical control is the use of biologicals. use of bacteria, fungi, viruses, pheromones, and metabolites to control these insects can potentially improve resistance management and reduce pesticide use. o ... | 2007 | 17598525 |
| inhibition of quorum sensing-regulated behaviors by scorzonera sandrasica. | many gram-negative bacteria use n-acyl homoserine lactone signal molecules to monitor their own population density and coordinate gene regulation in a process called quorum sensing (qs). increasing evidence implies that certain eukaryotes produce qs-inhibitory compounds. in this work, we tested 46 terrestrial plants materials for their ability to inhibit qs-regulated behaviors in different bacterial species. plant materials were dried and extracted using different solvents. the chloroform-solubl ... | 2007 | 17597339 |
| analysis of chromobacterium sp. natural isolates from different brazilian ecosystems. | chromobacterium violaceum is a free-living bacterium able to survive under diverse environmental conditions. in this study we evaluate the genetic and physiological diversity of chromobacterium sp. isolates from three brazilian ecosystems: brazilian savannah (cerrado), atlantic rain forest and amazon rain forest. we have analyzed the diversity with molecular approaches (16s rrna gene sequences and amplified ribosomal dna restriction analysis) and phenotypic surveys of antibiotic resistance and b ... | 2007 | 17584942 |
| dietary phytochemicals as quorum sensing inhibitors. | quorum sensing (qs) is a cell density dependent expression of species in bacteria mediated by hormone like compounds called autoinducers (ai). several processes responsible for successful establishment of bacterial infection are mediated by qs. inhibition of qs is therefore being considered as a new target for antimicrobial chemotherapy. dietary phytochemicals are secondary metabolites in plants known to have several health benefits including antimicrobial activity. however, their ability to inh ... | 2007 | 17499938 |
| gulbenkiania mobilis gen. nov., sp. nov., isolated from treated municipal wastewater. | a bacterial strain (e4fc31(t)) isolated from treated municipal wastewater was characterized phenotypically and phylogenetically. cells were gram-negative, curved rods with a polar flagellum. the isolate was catalase-, oxidase- and arginine dihydrolase-positive, and able to grow between 15 and 45 degrees c and between ph 5.5 and 9.0. the predominant fatty acids were c(16 : 1)/iso-c(15 : 0) 2-oh and c(16 : 0), the major respiratory quinone was ubiquinone 8 and the g+c content of the genomic dna wa ... | 2007 | 17473267 |
| chromobacterium subtsugae sp. nov., a betaproteobacterium toxic to colorado potato beetle and other insect pests. | strain praa4-1(t), a motile, gram-negative, violet-pigmented bacterium, was isolated from maryland forest soil and found to be orally toxic to colorado potato beetle larvae and other insects. morphological, biological, biochemical and molecular characterization revealed that this strain was most similar to chromobacterium violaceum, the type species and only currently recognized member of the genus chromobacterium. dna-dna hybridization with c. violaceum atcc 12472(t) was 27 %. phylogenetic anal ... | 2007 | 17473247 |
| signal mimics derived from a metagenomic analysis of the gypsy moth gut microbiota. | bacterial signaling is an important part of community life, but little is known about the signal transduction pathways of the as-yet-uncultured members of microbial communities. to address this gap, we aimed to identify genes directing the synthesis of signals in uncultured bacteria associated with the midguts of gypsy moth larvae. we constructed a metagenomic library consisting of dna extracted directly from the midgut microbiota and analyzed it using an intracellular screen designated metrex, ... | 2007 | 17435000 |
| characterization of a gene cluster responsible for the biosynthesis of anticancer agent fk228 in chromobacterium violaceum no. 968. | a gene cluster responsible for the biosynthesis of anticancer agent fk228 has been identified, cloned, and partially characterized in chromobacterium violaceum no. 968. first, a genome-scanning approach was applied to identify three distinctive c. violaceum no. 968 genomic dna clones that code for portions of nonribosomal peptide synthetase and polyketide synthase. next, a gene replacement system developed originally for pseudomonas aeruginosa was adapted to inactivate the genomic dna-associated ... | 2007 | 17400765 |
| genetic organization of the biosynthetic gene cluster for the indolocarbazole k-252a in nonomuraea longicatena jcm 11136. | indolocarbazole metabolite k-252a is a natural product that was previously reported as a potent protein kinase c inhibitor with in vitro and in vivo potency. from a biosynthetic viewpoint, this compound possesses structurally interesting features such as an unusual furanosyl sugar moiety, which are absent in the well-studied staurosporine and rebeccamycin. a cosmid library from genomic dna of nonomuraea longicatena jcm 11136 was constructed and screened for the presence of genes to be involved i ... | 2007 | 17396254 |
| the effect of quorum-sensing blockers on the formation of marine microbial communities and larval attachment. | we studied the effect of the quorum-sensing (qs) blockers 5-hydroxy-3[(1r)-1-hydroxypropyl]-4-methylfuran-2(5h)-one (fur1), (5r)-3,4-dihydroxy-5-[(1s)-1,2-dihydroxyethyl]furan-2(5h)-one (fur2) and triclosan (tri) on the formation of bacterial biofilms, and the effect of these biofilms on the larval attachment of the polychaete hydroides elegans and the bryozoan bugula neritina. 14-day-old subtidal biofilms were harvested from artificial substrata and were allowed to develop in the laboratory wit ... | 2007 | 17371321 |
| inhibitory effects of histone deacetylase inhibitor depsipeptide on benzo(a)pyrene- and cyclophosphamide-induced genotoxicity in swiss albino mice. | depsipeptide (fk228 or fr901228) was evaluated in the mouse bone marrow micronucleus test for its possible protective effect against chromosomal damage induced by benzo(a)pyrene and cyclophosphamide. three doses of depsipeptide (0.5, 1, and 1.5 mg/kg body weight) were given intravenously to mice for 7 consecutive days prior to administration of genotoxins under investigation. all the three doses of depsipeptide were effective in exerting a protective effect against both benzo(a)pyrene and cyclop ... | 2007 | 17365146 |
| stereochemical course of tryptophan dehydrogenation during biosynthesis of the calcium-dependent lipopeptide antibiotics. | [reaction: see text] hydrogen atoms are abstracted from the c2' and c3'-pro-s positions of an (s)-tryptophanyl precursor, with overall syn stereochemistry, during the biosynthesis of the c-terminal z-2',3'-dehydrotryptophan residue of the calcium-dependent lipopeptide antibiotics (cdas) in streptomyces coelicolor. the absence of beta-hydroxytryptophanyl, or other possible intermediates, further suggests a direct dehydrogenation mechanism similar to that proposed for the l-tryptophan 2',3'-oxidas ... | 2007 | 17355143 |
| nonionic surfactants: a key to enhance the enzyme activity at cationic reverse micellar interface. | the primary objective of the present study is to understand how the different nonionic surfactants modify the anisotropic interface of cationic water-in-oil (w/o) microemulsions and thus influences the catalytic efficiency of surface-active enzymes. activity of chromobacterium viscosum lipase (cv-lipase) was estimated in several mixed reverse micelles prepared from ctab and four different nonionic surfactants, brij-30, brij-92, tween-20, and tween-80/water/isooctane/n-hexanol at different z ([co ... | 2007 | 17348695 |
| a fatal case of chromobacterium violaceum septicemia in hong kong. | chromobacterium violaceum causes a rare infection in human, usually in tropical or subtropical areas. we report a fatal case of c. violaceum infection affecting a 40-year-old previously healthy man in hong kong. he presented with a wound infection and lymphadenitis. despite multiple antibiotic treatment, including ciprofloxacin, he succumbed shortly after admission to the hospital. we report the epidemiological investigation findings and discuss the possible sources of infection. physicians shou ... | 2006 | 17333774 |
| cloning and high-level production of a chitinase from chromobacterium sp. and the role of conserved or nonconserved residues on its catalytic activity. | a gene encoding an alkaline (pi of 8.67) chitinase was cloned and sequenced from chromobacterium sp. strain c-61. the gene was composed of 1,611 nucleotides and encoded a signal sequence of 26 n-terminal amino acids and a mature protein of 510 amino acids. two chitinases of 54 and 52 kda from both recombinant escherichia coli and c-61 were detected on sds-page. maximum chitinase activity was obtained in the culture supernatant of recombinant e. coli when cultivated in tb medium for 6 days at 37 ... | 2007 | 17294188 |
| crystallization and preliminary x-ray diffraction analysis of omega-amino acid:pyruvate transaminase from chromobacterium violaceum. | the enzyme omega-transaminase catalyses the conversion of chiral omega-amines to ketones. the recombinant enzyme from chromobacterium violaceum has been purified to homogeneity. the enzyme was crystallized from peg 4000 using the microbatch method. data were collected to 1.7 a resolution from a crystal belonging to the triclinic space group p1, with unit-cell parameters a = 58.9, b = 61.9, c = 63.9 a, alpha = 71.9, beta = 87.0, gamma = 74.6 degrees . data were also collected to 1.95 a from a sec ... | 2007 | 17277454 |
| in vitro biosynthesis of violacein from l-tryptophan by the enzymes vioa-e from chromobacterium violaceum. | the purple chromobacterial pigment violacein arises by enzymatic oxidation and coupling of two molecules of l-tryptophan to give a rearranged pyrrolidone-containing scaffold in the final pigment. we have purified five contiguously encoded proteins vioa-e after expression in escherichia coli and demonstrate the full 14-electron oxidation pathway to yield the final chromophore. the flavoenzyme vioa and the heme protein viob work in conjunction to oxidize and dimerize l-tryptophan to a nascent prod ... | 2006 | 17176066 |
| the serratia-type hemolysin of chromobacterium violaceum. | chromobacterium violaceum is a gram-negative opportunistic human pathogen and an inhabitant of tropical soils and waterways. although known primarily for the synthesis of the pigment violacein, and more recently as a reporter strain for quorum sensing, clinical reports of chromobacteriosis comprise the largest block of published literature on this organism. genome sequencing has revealed many potential virulence factors in this microorganism, and this paper establishes the presence in c. violace ... | 2007 | 17169000 |
| n-acyl homoserine lactones are degraded via an amidolytic activity in comamonas sp. strain d1. | comamonas strain d1 enzymatically inactivates quorum-sensing (qs) signal molecules of the n-acyl homoserine lactone (n-ahsl) family, and exhibits the broadest inactivation range of known bacteria. it degrades n-ahsl with acyl-side chains ranging from 4 to 16 carbons, with or without 3-oxo or 3-hydroxy substitutions. n-ahsl degradation yields hsl but not n-acyl homoserine: strain d1 therefore harbors an amidohydrolase activity. strain d1 is the fifth bacterium species in which an n-ahsl amidohydr ... | 2007 | 17136382 |