Publications
Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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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 |
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 |
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 |
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 |
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 |
structure of the pigment of chromobacterium iodinum. | 1948 | 18225130 | |
[successful treatment of a case with fatal sepsis caused by chromobacterium violaceum]. | 2007 | 18282432 | |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
chromobacterium violaceum infection in a provincial hospital in sri lanka. | 2008 | 19189802 | |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
synthesis, nematicidal and antimicrobial properties of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2(aryl)-tetrahydro-2h-pyrazolo[3,4-d]thiazol-5-yl]phenyl]methanes. | a new series of bis-[4-methoxy-3-[3-(4-fluorophenyl)-6-(4-methylphenyl)-2-(aryl)-3,3a,5,6-tetrahydro-2h-pyrazolo[3,4-d][1,3]thiazol-5-yl]phenyl]methanes 6a-r was synthesized by the reaction of arylidine derivative of methylene-bis-thiazolidinones 5a-c with aryl/alkyl hydrazines. chemical structures of all the new compounds were established by ir, (1)h-nmr, (13)c-nmr, ms and elemental data. the compounds 6a-r were evaluated for their nematicidal activity against ditylenchus myceliophagus and caen ... | 2009 | 19571412 |
blocking of pseudomonas aeruginosa and ralstonia solanacearum lectins by plant and microbial branched polysaccharides used as food additives. | pseudomonas aeruginosa antibiotic resistance prompted the search for glycodecoys that would block its lectin-dependent adhesion to human cells. we have used the lectins of this pathogen, pa-il (galactophilic leca) and pa-iil (fucophilic lecb), and two additional pathogenic bacterial lectins, cv-iil (fucophilic, of chromobacterium violaceum) and rs-iil (mannophilic, of ralstonia solanacearum), for assaying the pathogenic lectin-blocking abilities of some plant and microbial polysaccharidic food a ... | 2009 | 19572540 |
immunomodulatory, analgesic and antipyretic effects of violacein isolated from chromobacterium violaceum. | violacein was isolated from chromobacterium violaceum, a soil gram negative bacterium collected from the forest water body soil sample of kolli hills; tamil nadu, india. in the present study the immunomodulatory, analgesic and antipyretic activities of violacein were investigated in wistar rats and mice. analgesic effect was evaluated by acetic acid- induced writhing, formalin induced paw licking and hotplate tests. immunomodulatory effect was investigated by using ovalbumin- induced active paw ... | 2010 | 19576742 |
chromobacterium piscinae sp. nov. and chromobacterium pseudoviolaceum sp. nov., from environmental samples. | two strains (lmg 3947 and lmg 3953) of motile, gram-negative, violet-pigmented bacteria, respectively isolated in 1972 and before 1953 from environmental samples and previously assigned to chromobacterium violaceum, were studied again in detail for their taxonomic position. 16s rrna gene sequence analysis showed that both strains clustered together with the type strain of chromobacterium violaceum (99.8 % sequence similarity for strain lmg 3953(t) and 98.9 % sequence similarity for lmg 3947(t)). ... | 2009 | 19622653 |
inhibition of quorum sensing regulated bacterial functions by plant essential oils with special reference to clove oil. | to evaluate quorum sensing (qs) inhibitory activity of plant essential oils using strains of chromobacterium violaceum (cv12472 and cvo26) and pseudomonas aeruginosa (pao1). | 2009 | 19627477 |
fatal chromobacterium violaceum septicaemia in northern laos, a modified oxidase test and post-mortem forensic family g6pd analysis. | chromobacterium violaceum is a gram negative facultative anaerobic bacillus, found in soil and stagnant water, that usually has a violet pigmented appearance on agar culture. it is rarely described as a human pathogen, mostly from tropical and subtropical areas. | 2009 | 19640274 |
a quorum-sensing antagonist targets both membrane-bound and cytoplasmic receptors and controls bacterial pathogenicity. | quorum sensing is a process of bacterial communication involving production and detection of secreted molecules called autoinducers. gram-negative bacteria use acyl-homoserine lactone (ahl) autoinducers, which are detected by one of two receptor types. first, cytoplasmic luxr-type receptors bind accumulated intracellular ahls. ahl-luxr complexes bind dna and alter gene expression. second, membrane-bound luxn-type receptors bind accumulated extracellular ahls. ahl-luxn complexes relay information ... | 2009 | 19647512 |
enhancement of l-tryptophan 5-hydroxylation activity by structure-based modification of l-phenylalanine 4-hydroxylase from chromobacterium violaceum. | the objective of this study was to enhance l-tryptophan hydroxylation activity of l-phenylalanine 4-hydroxylase. it had been known that l-phenylalanine 4-hydroxylase from chromobacterium violaceum could convert l-tryptophan to 5-hydroxy-l-tryptophan and l-phenylalanine to l-tyrosine; however, the activity for l-tryptophan was extremely low compared to l-phenylalanine activity levels. we used the information on the crystal structures of aromatic amino acid hydroxylases to generate c. violaceuml-p ... | 2009 | 19664549 |
tocopherol, carotene, phenolic contents and antibacterial properties of rose essential oil, hydrosol and absolute. | the antioxidant and antibacterial activities, and total phenolic contents of rosa damascena mill. flower extracts (absolute, essential oil and hydrosol) were investigated. the chemical compositions of these extracts were analysed by gc-ms. phenylethyl alcohol (78.38%) was found to be the main constituent of rose absolute, while citrenellol and geraniol were the major compounds (>55%) of rose essential oil and hydrosol. tocopherol and carotene levels were determined by high performance liquid chr ... | 2009 | 19688375 |
anti-diarrhoeal and ulcer-protective effects of violacein isolated from chromobacterium violaceum in wistar rats. | violacein was isolated from chromobacterium violaceum, a soil gram-negative bacterium collected from the forest water body soil sample from kolli hills of tamil nadu, india. in the present study the anti-diarrhoeal and ulcer-protective properties of violacein were investigated in wistar rats using castor oil, magnesium sulphate and ethanol. the intestinal transit in rats was significantly (p < 0.001) reduced and gastric emptying was delayed; 40 mg/kg of violacein elicited a greater anti-motility ... | 2009 | 19709325 |
quorum sensing inhibition activity of garlic extract and p-coumaric acid. | the goal of this work was to investigate the influence of dmso, garlic extract and p-coumaric acid on bacterial quorum sensing (qs). | 2009 | 19709367 |
chromobacterium violaceum sepsis in an infant. | chromobacterium violaceum is a rare pathogen that can cause potentially fatal infections in humans. till date, 150 cases are reported worldwide including 7 from india. we report a 6 month old infant who presented with high grade fever, respiratory distress and multiple vesicular skin lesions. chromobacterium violaceum was isolated from blood, bone marrow aspirate and from skin lesions. infant responded to treatment with piperacillin and ciprofloxacin, and is doing well on follow up. | 2009 | 19717863 |
efficient synthesis and evaluation of quorum-sensing modulators using small molecule macroarrays. | a method for the synthesis of small molecule macroarrays of n-acylated l-homoserine lactones (ahls) is reported. a focused library of ahls was constructed, and the macroarray platform was found to be compatible with both solution and agar-overlay assays using quorum-sensing (qs) reporter strains. several qs antagonists were discovered and serve to showcase the macroarray as a straightforward technique for qs research. | 2009 | 19743816 |
[cloning of phzir from the endophytic pseudomonas sp. g5 and its expression in escherichia coli]. | we isolated a new strain of endophytic pseudomonas g5 from the stems of chinese parsley (coriandrum sativum l.), and it is tentatively identified as pseudomonas aurantiaca according to analysis of the entire substrate utilization profiles using biolog microstation system (biolog, inc, hayward ca). an array of evidence established that many gram-negative bacteria employ quorum sensing (qs) system to regulate gene expression in response to cell density using small diffusible signal molecules, n-ac ... | 2009 | 19777809 |
microbial growth and quorum sensing antagonist activities of herbal plants extracts. | antimicrobial and antiquorum sensing (aqs) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four gram-positive, five gram-negative bacteria and four fungi. depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. among the grampositive bacteria tested, for example, activities of laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against bacillus subtilis up to a 25 m ... | 2009 | 19783935 |
chromobacterium violaceum endocarditis and hepatic abscesses treated successfully with meropenem and ciprofloxacin. | 2009 | 19807647 | |
inhibition of quorum-sensing signals by essential oils. | the role of quorum sensing (qs) is well known in microbial pathogenicity and antibiotic resistance. qs is responsible for motility, swarming, and biofilm production based on the signal molecules, e.g., acylated homoserine lactones (ahls) produced by micro-organisms above certain population density. the inhibition of qs may reduce pathogenicity, antibiotic resistance and biofilm formation in systemic and local infections. the homoserine lactones and other transmitters contribute to antibiotic res ... | 2010 | 19827025 |
nanocytotoxicity: violacein and violacein-loaded poly (d, l-lactide-co-glycolide) nanoparticles acting on human leukemic cells. | violacein is a compound obtained from chromobacterium violaceum, a bacterium found in the amazonian region. violacein-loaded poly (d, l-lactide-co-glycolide) nanoparticles has a similar inhibitory effect evaluated by trypan blue assay on leukemic hl60 cells than the free form. however, the cytotoxic effects evaluated by phosphatase activity and mtt reduction assays were lower for the encapsulated form than for free violacein. based on morphological changes, violacein and violacein entrapped in n ... | 2009 | 20055097 |
cigarette smoking during pregnancy: chromosome translocations and phenotypic susceptibility in mothers and newborns. | the effects of maternal cigarette smoking during pregnancy on structural chromosome aberrations were evaluated in peripheral lymphocytes from 239 mothers and their 241 newborns to determine whether smoking during pregnancy, genetic susceptibility, and race are associated with chromosome aberrations including translocations. demographic information and cigarette smoking data were obtained via questionnaire. there were 119 caucasian americans, 118 african americans, and 2 asian americans. the aver ... | 2010 | 20060061 |
chromobacterium violaceum infection in a free-ranging howler monkey in costa rica. | chromobacterium violaceum is a gram-negative saprobe bacterium that is a rare opportunistic pathogen in mammals. there are numerous reports in humans including fatalities, but no record exists in free-ranging nonhuman primates. here we report an infection by c. violaceum in a wild adult male howler monkey (alouatta palliata) captured at ballena marine national park, in southwestern costa rica. the individual had severe skin lesions over its extremities; gross findings included multiple skin ulce ... | 2010 | 20090050 |
structural characterization of the organic solvent-stable cholesterol oxidase from chromobacterium sp. ds-1. | cholesterol oxidase is of significant commercial interest as it is widely used as a biosensor for the detection of cholesterol in clinical samples, blood serum and food. increased stability of this enzyme with regards to temperature and different solvent conditions are of great importance to the reliability and versatility of its applications. we here report the crystal structure of the cholesterol oxidase of chromobacterium sp. ds-1 (cholox). in contrast to other previously characterized choles ... | 2010 | 20102741 |
blocking of pseudomonas aeruginosa and chromobacterium violaceum lectins by diverse mammalian milks. | pseudomonas aeruginosa and chromobacterium violaceum morbid and mortal infections are initiated by bacterial adherence to host-cell receptors via their adhesins, including lectins (which also contribute to bacterial biofilm formation). pseudomonas aeruginosa produces a galactophilic lectin, pa-il (leca), and a fucophilic (lewis-specific) lectin, pa-iil (lecb), and c. violaceum produces a fucophilic (h-specific) lectin, cv-iil. the antibiotic resistance of these bacteria prompted the search for g ... | 2010 | 20105519 |
secondary colonies of bacteria induced by salts of alkali metals, with special reference to chromobacterium violaceum and other bacteria on lithium chloride agar. | 1947 | 20295177 | |
measurement of the intramolecular isotope effect on aliphatic hydroxylation by chromobacterium violaceum phenylalanine hydroxylase. | the non-heme iron enzyme phenylalanine hydroxylase from chromobacterium violaceum has previously been shown to catalyze the hydroxylation of benzylic and aliphatic carbons in addition to the normal aromatic hydroxylation reaction. the intrinsic isotope effect for hydroxylation of 3-cyclochexylalanine by the enzyme was determined in order to gain insight into the reactivity of the iron center. with 3-[(2)h(11)-cyclohexyl]alanine as the substrate, the isotope effect on the k(cat) value was 1, cons ... | 2010 | 20355730 |
rapid degradation of n-3-oxo-acylhomoserine lactones by a bacillus cereus isolate from malaysian rainforest soil. | a bacterial strain, km1s, was isolated from a malaysian rainforest soil sample by using a defined enrichment medium that specifically facilitates selection of quorum quenching bacteria. km1s was clustered closely to bacillus cereus by 16s ribosomal dna sequence analysis. it degraded n-3-oxo-hexanoyl homoserine lactone and n-3-oxo-octanoyl homoserine lactone in vitro rapidly at 4.98 and 6.56 microg ahl h(-1) per 10(9) cfu/ml, respectively, as determined by the rapid resolution liquid chromatograp ... | 2010 | 20376561 |
the unique kinetic behavior of the very large nad-dependent glutamate dehydrogenase from janthinobacterium lividum. | the kinetics of a very large nad-dependent glutamate dehydrogenase from janthinobacterium lividum showed positive cooperativity toward alpha-ketoglutarate and nadh, and the michaelis-menten type toward ammonium chloride in the absence of the catalytic activator, l-aspartate. an increase in the maximum activity accompanied the decrease in the s(0.5) values for alpha-ketoglutarate and nadh with the addition of l-aspartate, and the kinetic response for alpha-ketoglutarate changed completely to a ty ... | 2010 | 20378971 |
bacillus pumilus of palk bay origin inhibits quorum-sensing-mediated virulence factors in gram-negative bacteria. | the aim of the current study was to inhibit quoring-sensing(qs)-mediated virulence factors of representative gram-negative bacteria by marine bacterial isolates. bacteria isolated from palk bay sediments were screened for anti-qs activity. eleven strains inhibited qs signals in chromobacterium violaceum (atcc 12472) and c. violaceum cv026. the marine bacterial strain s8-07 reduced the accumulation of n-acyl homoserine lactone (ahls) and showed significant inhibition of lasa protease(76%), lasb e ... | 2010 | 20381609 |
growth inhibition and pro-apoptotic activity of violacein in ehrlich ascites tumor. | the continuing threat to biodiversity lends urgency to the need of identification of sustainable source of natural products. this is not so much trouble if there is a microbial source of the compound. herein, violacein, a natural indolic pigment extracted from chromobacterium violaceum, was evaluated for its antitumoral potential against the ehrlich ascites tumor (eat) in vivo and in vitro. evaluation of violacein cytotoxicity using different endpoints indicated that eat cells were twofold (ic(5 ... | 2010 | 20416285 |
water-in-ionic liquid microemulsion-based organogels as novel matrices for enzyme immobilization. | the use of water-in-ionic liquid microemulsion-based organogels (w/il mbgs) as novel supports for the immobilization of lipase b from candida antarctica and lipase from chromobacterium viscosum was investigated. these novel lipase-containing w/il mbgs can be effectively used as solid phase biocatalysts in various polar and non-polar organic solvents or ils, exhibiting up to 4.4-fold higher esterification activity compared to water-in-oil microemulsion-based organogels. the immobilized lipases re ... | 2010 | 20449844 |
novel tryptophan metabolites, chromoazepinone a, b and c, produced by a blocked mutant of chromobacterium violaceum, the biosynthetic implications and the biological activity of chromoazepinone a and b. | chromobacterium violaceum produces tryptophan metabolites, purple pigments of violacein and deoxyviolacein. a blocked mutant was prepared with n-methyl-n'-nitrosoguanidine to gain insights into the biosynthetic mechanisms of the pigments. five tryptophan metabolites were isolated: three novel compounds, named chromoazepinone a, b and c and two known compounds, chromopyrrolic acid and arcyriarubin a. the structure determinations of the three novel compounds are described. the biosynthetic pathway ... | 2010 | 20490411 |
chromobacterium pathogenicity island 1 type iii secretion system is a major virulence determinant for chromobacterium violaceum-induced cell death in hepatocytes. | summary chromobacterium violaceum is a gram-negative bacterium that causes fatal septicaemia in humans and animals. c. violaceum atcc 12472 possesses genes associated with two distinct type iii secretion systems (t3sss). one of these systems is encoded by chromobacterium pathogenicity islands 1 and 1a (cpi-1/-1a), another is encoded by chromobacterium pathogenicity island 2 (cpi-2). here we show that c. violaceum causes fulminant hepatitis in a mouse infection model, and cpi-1/-1a-encoded t3ss i ... | 2010 | 20545857 |
antimycobacterial activity in vitro of pigments isolated from antarctic bacteria. | in this study, we describe the antimycobacterial activity of two pigments, violacein, a purple violet pigment from janthinobacterium sp. ant5-2 (j-pvp), and flexirubin, a yellow-orange pigment from flavobacterium sp. ant342 (f-yop). these pigments were isolated from bacterial strains found in the land-locked freshwater lakes of schirmacher oasis, east antarctica. the minimum inhibitory concentrations (mics) of these pigments for avirulent and virulent mycobacteria were determined by the micropla ... | 2010 | 20556653 |
identification and characterization of a novel bacterial atp-sensitive k+ channel. | five bacterial species that are most likely to have putative prokaryotic inward rectifier k(+) (kir) channels were selected by in silico sequence homology and membrane topology analyses with respect to the number of transmembrane domains (tms) and the presence of k(+) selectivity filter and/or atp binding sites in reference to rabbit heart inward rectifier k(+) channel (kir6.2). a dot blot assay with genomic dnas when probed with whole rabbit kir6.2 cdna further supported the in silico analysis ... | 2010 | 20571950 |
origin of the pka shift of the catalytic lysine in acetoacetate decarboxylase. | the pka value of lys115, the catalytic residue in acetoacetate decarboxylate, was calculated using atomic coordinates of the x-ray crystal structure with consideration of the protonation states of all titratable sites in the protein. the calculated pka value of lys115 (pka(lys115)) was unusually low (approximately 6) in agreement with the experimentally measured value. although charged residues impact pka(lys115) considerably in the native protein, the significant pka(lys115) downshift in the pr ... | 2010 | 20621098 |
phenotypic and physiological alterations by heterologous acylhomoserine lactone synthase expression in pseudomonas putida. | many bacteria harbour an incomplete quorum-sensing (qs) system, whereby they possess luxr homologues without the qs acylhomoserine lactone (ahl) synthase, which is encoded by a luxi homologue. an artificial ahl-producing plasmid was constructed using a cvii gene encoding the c6-ahl [n-hexanoyl homoserine lactone (hhl)] synthase from chromobacterium violaceum, and was introduced successfully into both the wild-type and a ppor (luxr homologue) mutant of pseudomonas putida. our data provide evidenc ... | 2010 | 20705668 |
evaluation of anti-quorum-sensing activity of edible plants and fruits through inhibition of the n-acyl-homoserine lactone system in chromobacterium violaceum and pseudomonas aeruginosa. | to find out an alternative strategy to antibiotic usage against bacterial infection. | 2010 | 20720417 |
comparative biogeography of chromobacterium from the neotropics. | the genus chromobacterium encompasses free-living gram-negative bacteria. until 2007, the genus consisted of only one species but six species are now recognized. chromobacterium violaceum is the type species of the genus and is commonly found in soil and water in tropical and sub-tropical regions. we have investigated a collection of 111 isolates displaying violet pigmentation from undisturbed aquatic and soil environments from brazilian cerrado ecosystem. the 16s rrna gene phylogeny revealed th ... | 2011 | 20803105 |