| biocatalytic potential of vanillin aminotransferase from capsicum chinense. | the conversion of vanillin to vanillylamine is a key step in the biosynthetic route towards capsaicinoids in pungent cultivars of capsicum sp. the reaction has previously been annotated to be catalysed by pamt (putative aminotransferase; [genbank: aac78480.1, swiss-prot: o82521]), however, the enzyme has previously not been biochemically characterised in vitro. | 2014 | 24712445 |
| microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping. | despite microbes' key roles in driving biogeochemical cycles, the mechanism of microbe-mediated feedbacks to global changes remains elusive. recently, soil transplant has been successfully established as a proxy to simulate climate changes, as the current trend of global warming coherently causes range shifts toward higher latitudes. four years after southward soil transplant over large transects in china, we found that microbial functional diversity was increased, in addition to concurrent chan ... | 2014 | 24694714 |
| surface expression of ω-transaminase in escherichia coli. | chiral amines are important for the chemical and pharmaceutical industries, and there is rapidly growing interest to use transaminases for their synthesis. since the cost of the enzyme is an important factor for process economy, the use of whole-cell biocatalysts is attractive, since expensive purification and immobilization steps can be avoided. display of the protein on the cell surface provides a possible way to reduce the mass transfer limitations of such biocatalysts. however, transaminases ... | 2014 | 24487538 |
| the natural antimicrobial carvacrol inhibits quorum sensing in chromobacterium violaceum and reduces bacterial biofilm formation at sub-lethal concentrations. | the formation of biofilm by bacteria confers resistance to biocides and presents problems in medical and veterinary clinical settings. here we report the effect of carvacrol, one of the major antimicrobial components of oregano oil, on the formation of biofilms and its activity on existing biofilms. assays were carried out in polystyrene microplates to observe (a) the effect of 0-0.8 mm carvacrol on the formation of biofilms by selected bacterial pathogens over 24 h and (b) the effect of 0-8 mm ... | 2014 | 24691035 |
| erasers of histone acetylation: the histone deacetylase enzymes. | histone deacetylases (hdacs) are enzymes that catalyze the removal of acetyl functional groups from the lysine residues of both histone and nonhistone proteins. in humans, there are 18 hdac enzymes that use either zinc- or nad(+)-dependent mechanisms to deacetylate acetyl lysine substrates. although removal of histone acetyl epigenetic modification by hdacs regulates chromatin structure and transcription, deacetylation of nonhistones controls diverse cellular processes. hdac inhibitors are alrea ... | 2014 | 24691964 |
| the structural basis of an nadp⁺-independent dithiol oxidase in fk228 biosynthesis. | the disulfide bond is unusual in natural products and critical for thermal stability, cell permeability and bioactivity. deph from chromobacterium violaceum no. 968 is an fad-dependent enzyme responsible for catalyzing the disulfide bond formation of fk228, an anticancer prodrug approved for the treatment of cutaneous t-cell lymphoma. here we report the crystal structures of deph and deph complexed with a substrate analogue s,s'-dimethyl fk228 at 1.82 å and 2.00 å, respectively. structural and b ... | 2014 | 24553401 |
| essential oils, a new horizon in combating bacterial antibiotic resistance. | for many years, the battle between humans and the multitudes of infection and disease causing pathogens continues. emerging at the battlefield as some of the most significant challenges to human health are bacterial resistance and its rapid rise. these have become a major concern in global public health invigorating the need for new antimicrobial compounds. a rational approach to deal with antibiotic resistance problems requires detailed knowledge of the different biological and non-biological f ... | 2014 | 24627729 |
| proton transfer reactions and hydrogen-bond networks in protein environments. | in protein environments, proton transfer reactions occur along polar or charged residues and isolated water molecules. these species consist of h-bond networks that serve as proton transfer pathways; therefore, thorough understanding of h-bond energetics is essential when investigating proton transfer reactions in protein environments. when the pka values (or proton affinity) of the h-bond donor and acceptor moieties are equal, significantly short, symmetric h-bonds can be formed between the two ... | 2014 | 24284891 |
| characterization of n-acyl-homoserine lactones (ahls)-deficient clinical isolates of pseudomonas aeruginosa. | pseudomonas aeruginosa is an opportunistic pathogen causing severe respiratory infections. acylated homoserine lactones (ahls) are self-generated diffusible signal molecules that mediate population density dependent gene expression (quorum sensing, qs) in a variety of gram-negative bacteria, and several virulence genes of bacterial pathogens are known to be controlled by qs. hence, fitness mutant of virulent factors is beneficial for natural selection. in this study, strains of p. aeruginosa iso ... | 2014 | 25320416 |
| isolation and molecular characterization of biofouling bacteria and profiling of quorum sensing signal molecules from membrane bioreactor activated sludge. | the formation of biofilm in a membrane bioreactor depends on the production of various signaling molecules like n-acyl homoserine lactones (ahls). in the present study, a total of 200 bacterial strains were isolated from membrane bioreactor activated sludge and screened for ahls production using two biosensor systems, chromobacterium violaceum cv026 and agrobacterium tumefaciens a136. a correlation between ahls production and biofilm formation has been made among screened ahls producing strains. ... | 2014 | 24499972 |
| a regio- and stereoselective ω-transaminase/monoamine oxidase cascade for the synthesis of chiral 2,5-disubstituted pyrrolidines. | biocatalytic approaches to the synthesis of optically pure chiral amines, starting from simple achiral building blocks, are highly desirable because such motifs are present in a wide variety of important natural products and pharmaceutical compounds. herein, a novel one-pot ω-transaminase (ta)/monoamine oxidase (mao-n) cascade process for the synthesis of chiral 2,5-disubstituted pyrrolidines is reported. the reactions proceeded with excellent enantio- and diastereoselectivity (>94 % ee; >98 % d ... | 2014 | 24478044 |
| haloperoxidase mediated quorum quenching by nitzschia cf pellucida: study of the metabolization of n-acyl homoserine lactones by a benthic diatom. | diatoms are known to produce a variety of halogenated compounds, which were recently shown to have a role in allelopathic interactions between competing species. the production of these compounds is linked to haloperoxidase activity. this research, has shown that this system may also be involved in diatom-bacteria interactions via the h2o2 dependent inactivation of a type of quorum sensing (qs) molecule, i.e., n-β-ketoacylated homoserine lactones (ahls), by a natural haloperoxidase system from t ... | 2014 | 24445305 |
| novel glycolipids synthesized using plant essential oils and their application in quorum sensing inhibition and as antibiofilm agents. | essential oils (eos) form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. however it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. the present paper reports synthesis of sophorolipids using 12 different essenti ... | 2014 | 24558341 |
| characterization of chromobacterium violaceum pigment through a hyperspectral imaging system. | in this paper, a comprehensive spatio-spectral and temporal analysis for chromobacterium violaceum colonies is reported. a hyperspectral imaging (hsi) system is used to recover the spectral signatures of pigment production in a non-homogeneous media with high spectral resolution and high sensitivity in vivo, without destructing the sample. this non-contact sensing technique opens avenues to study the temporal growing of a specific section in the bacterial colony. further, from a 580 [nm] and 764 ... | 2014 | 24417877 |
| prospecting for unannotated enzymes: discovery of a 3',5'-nucleotide bisphosphate phosphatase within the amidohydrolase superfamily. | in bacteria, 3',5'-adenosine bisphosphate (pap) is generated from 3'-phosphoadenosine 5'-phosphosulfate in the sulfate assimilation pathway, and from coenzyme a by the transfer of the phosphopantetheine group to the acyl-carrier protein. pap is subsequently hydrolyzed to 5'-amp and orthophosphate, and this reaction has been shown to be important for superoxide stress tolerance. herein, we report the discovery of the first instance of an enzyme from the amidohydrolase superfamily that is capable ... | 2014 | 24401123 |
| acyl-homoserine lactone quorum sensing in the roseobacter clade. | members of the roseobacter clade are ecologically important and numerically abundant in coastal environments and can associate with marine invertebrates and nutrient-rich marine snow or organic particles, on which quorum sensing (qs) may play an important role. in this review, we summarize current research progress on roseobacterial acyl-homoserine lactone-based qs, particularly focusing on three relatively well-studied representatives, phaeobacter inhibens dsm17395, the marine sponge symbiont r ... | 2014 | 24402124 |
| expression, crystallization and preliminary crystallographic data analysis of viod, a hydroxylase in the violacein-biosynthesis pathway. | violacein, a natural purple secondary metabolite, is sequentially biosynthesized by five enzymes in the following pathway: vioa-viob-vioe-viod-vioc. viod, a flavin-dependent oxygenase, catalyzes the hydroxylation of the intermediate product prodeoxyviolaceinic acid (pva) at the 5-position of one indole ring to yield proviolacein. in vitro biochemical data have revealed this process, but the catalytic mechanism still remains largely unclear. here, the cloning, expression, purification, crystalliz ... | 2015 | 25664787 |
| influence of salmonella enterica serovar typhimurium ssrb on colonization of eastern oysters (crassostrea virginica) as revealed by a promoter probe screen. | although salmonella has been isolated from 7.4 to 8.6% of domestic raw oysters, representing a significant risk for food-borne illness, little is known about the factors that influence their initial colonization by salmonella. this study tested the hypothesis that specific regulatory changes enable a portion of the invading salmonella population to colonize oysters. an in vivo promoter probe library screen identified 19 unique regions as regulated during colonization. the mutants in the nearest ... | 2015 | 26497459 |
| influence of salmonella enterica serovar typhimurium ssrb on colonization of eastern oysters (crassostrea virginica) as revealed by a promoter probe screen. | although salmonella has been isolated from 7.4 to 8.6% of domestic raw oysters, representing a significant risk for food-borne illness, little is known about the factors that influence their initial colonization by salmonella. this study tested the hypothesis that specific regulatory changes enable a portion of the invading salmonella population to colonize oysters. an in vivo promoter probe library screen identified 19 unique regions as regulated during colonization. the mutants in the nearest ... | 2015 | 26497459 |
| a plasmid-transposon hybrid mutagenesis system effective in a broad range of enterobacteria. | random transposon mutagenesis is a powerful technique used to generate libraries of genetic insertions in many different bacterial strains. here we develop a system facilitating random transposon mutagenesis in a range of different gram-negative bacterial strains, including pectobacterium atrosepticum, citrobacter rodentium, serratia sp. atcc39006, serratia plymuthica, dickeya dadantii, and many more. transposon mutagenesis was optimized in each of these strains and three studies are presented t ... | 2015 | 26733980 |
| distribution in different organisms of amino acid oxidases with fad or a quinone as cofactor and their role as antimicrobial proteins in marine bacteria. | amino acid oxidases (aaos) catalyze the oxidative deamination of amino acids releasing ammonium and hydrogen peroxide. several kinds of these enzymes have been reported. depending on the amino acid isomer used as a substrate, it is possible to differentiate between l-amino acid oxidases and d-amino acid oxidases. both use fad as cofactor and oxidize the amino acid in the alpha position releasing the corresponding keto acid. recently, a novel class of aaos has been described that does not contain ... | 2015 | 26694422 |
| chromobacterium violaceum isolated from a wound sepsis: a case study from nepal. | chromobacterium violaceum is a facultative anaerobic, gram-negative rod, prevalent in tropical and subtropical regions. it enters through the skin injury and is capable of causing severe systemic infections leading to septic shock and multiorgan failure. it has been reported by few authors across the world but this is probably the first case of chromobacterium violaceum isolated from wound sepsis from nepal. in this study, a pus sample from the infection of a prick injury in the left middle fing ... | 2015 | 26788383 |
| successful treatment of chromobacterium violaceum sepsis in a south indian adult. | infection due to chromobacterium violaceum is rare. diagnosis may be delayed since chromobacterium sepsis may mimic melioidosis, especially in melioidosis-endemic areas. management of chromobacterium infection is challenging given the propensity of this pathogen to cause visceral abscesses, drug resistance, and relapse. mortality rates are high despite treatment. we report a case of c. violaceum septicemia in an immunocompetent adult from south india, who was successfully treated with combinatio ... | 2015 | 26304923 |
| directed evolution and resolution mechanism of 1, 3-propanediol oxidoreductase from klebsiella pneumoniae toward higher activity by error-prone pcr and bioinformatics. | 1, 3-propanediol oxidoreductase (pdor) is a key enzyme in glycerol bioconversion to 1,3-propanediol (1, 3-pd) which is a valuable chemical and one of the six new petrochemical products. we used error-prone pcr and activity screening to identify mutants of klebsiella pneumoniae (k. pneumoniae) pdor with improved activity. the activity of one of the identified mutants, pdor'-24, which includes a single mutation, a199s, was 48 u/mg, 4.9 times that of the wild-type enzyme. molecular docking was perf ... | 2015 | 26528716 |
| chromobacterium violaceum sepsis: rethinking conventional therapy to improve outcome. | chromobacterium violaceum (c. violaceum) is a facultative anaerobic gram-negative bacterium found in soil and water, especially in tropical and subtropical areas. although infection in humans is rare, it is associated with significant morbidity. the bacterium is known for its resistance to multiple antimicrobials, and the possibility of relapse and reinfection. presence of bacteremia, disseminated infection, and ineffective antimicrobial agents are predictors of mortality. | 2015 | 26477750 |
| romidepsin targets multiple survival signaling pathways in malignant t cells. | romidepsin is a cyclic molecule that inhibits histone deacetylases. it is food and drug administration-approved for treatment of cutaneous and peripheral t-cell lymphoma, but its precise mechanism of action against malignant t cells is unknown. to better understand the biological effects of romidepsin in these cells, we exposed peer and supt1 t-cell lines, and a primary sample from t-cell lymphoma patient (patient j) to romidepsin. we then examined the consequences in some key oncogenic signalin ... | 2015 | 26473529 |
| exposure to sub-inhibitory concentrations of cefotaxime enhances the systemic colonization of salmonella typhimurium in balb/c mice. | it has been proposed that sub-inhibitory concentrations of antibiotics play a role in virulence modulation. in this study, we evaluated the ability of salmonella enterica serovar typhimurium (hereafter s. typhimurium) to colonize systemically balb/c mice after exposure to a sub-inhibitory concentration of cefotaxime (ctx). in vivo competition assays showed a fivefold increase in systemic colonization of ctx-exposed bacteria when compared to untreated bacteria. to identify the molecular mechanism ... | 2015 | 26468132 |
| asymptomatic bacteriuria caused by chromobacterium violaceum in an immunocompetent adult. | because of increasing antimicrobial resistance, the treatment of the asymptomatic bacteriuria is not considered except in specific circumstances like during pregnancy or before invasive urologic procedures. we are reporting a first case of asymptomatic bacteriuria caused by chromobacterium violaceum in a 16-year-old male. with the reporting of the c. violaceum which is notorious for its high propensity for hematogenous dissemination causing fatal sepsis (with reported mortality rate up to 65-80% ... | 2015 | 26504464 |
| interference of quorum sensing by delftia sp. vm4 depends on the activity of a novel n-acylhomoserine lactone-acylase. | turf soil bacterial isolate delftia sp. vm4 can degrade exogenous n-acyl homoserine lactone (ahl), hence it effectively attenuates the virulence of bacterial soft rot pathogen pectobacterium carotovorum subsp. carotovorum strain br1 (pcc br1) as a consequence of quorum sensing inhibition. | 2015 | 26384328 |
| regulation of gaca in pseudomonas chlororaphis strains shows a niche specificity. | the gacs/gaca two-component system plays a central role in the regulation of a broad range of biological functions in many bacteria. in the biocontrol organism pseudomonas chlororaphis, the gac system has been shown to positively control quorum sensing, biofilm formation, and phenazine production, but has an overall negative impact on motility. these studies have been performed with strains originated from the rhizosphere predominantly. to investigate the level of conservation between the gaca r ... | 2015 | 26379125 |
| urinary tract infection caused by chromobacterium violaceum. | chromobacterium violaceum, a proteobacterium, is a facultative anaerobe, which is generally present as the normal flora of water and soil in tropical and subtropical regions. the infection due to chromobacterium violaceum is rare but mostly fatal. it is responsible for causing fatal cases of septicemia, visceral abscesses, skin and soft tissue infections, meningitis, diarrhea, and rarely urinary tract infection. the bacteria has high propensity to spread causing sepsis. delayed proper treatment ... | 2015 | 26392784 |
| mycofabricated biosilver nanoparticles interrupt pseudomonas aeruginosa quorum sensing systems. | quorum sensing (qs) is a chemical communication process that pseudomonas aeruginosa uses to regulate virulence and biofilm formation. disabling of qs is an emerging approach for combating its pathogenicity. silver nanoparticles (agnps) have been widely applied as antimicrobial agents against human pathogenic bacteria and fungi, but not for the attenuation of bacterial qs. here we mycofabricated agnps (mfagnps) using metabolites of soil fungus rhizopus arrhizus brs-07 and tested their effect on q ... | 2015 | 26347993 |
| amination of ω-functionalized aliphatic primary alcohols by a biocatalytic oxidation-transamination cascade. | amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from aspergillus fumigatus (lcao_af) with a ω-transaminase from chromobacterium violaceum (ω-ta_cv). the alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the plp-dependent ω-ta to yield the final primary amine product. the overall cascade w ... | 2015 | 26583050 |
| a novel designed bioreactor for recovering precious metals from waste printed circuit boards. | for recovering precious metals from waste printed circuit boards (pcbs), a novel hybrid technology including physical and biological methods was developed. it consisted of crushing, corona-electrostatic separation, and bioleaching. bioleaching process is the focus of this paper. a novel bioreactor for bioleaching was designed. bioleaching was carried out using pseudomonas chlororaphis. bioleaching experiments using mixed particles of au and cu were performed and leachate contained 0.006 mg/l, 28 ... | 2015 | 26316021 |
| rapid bioassay-guided isolation of antibacterial clerodane type diterpenoid from dodonaea viscosa (l.) jaeq. | plant extracts are complex matrices and, although crude extracts are widely in use, purified compounds are pivotal in drug discovery. this study describes the application of automated preparative-hplc combined with a rapid off-line bacterial bioassay, using reduction of a tetrazolium salt as an indicator of bacterial metabolism. this approach enabled the identification of fractions from dodonaea viscosa that were active against staphylococcus aureus and escherichia coli, which, ultimately, resul ... | 2015 | 26343638 |
| canonical inflammasomes drive ifn-γ to prime caspase-11 in defense against a cytosol-invasive bacterium. | the inflammatory caspases 1 and 11 are activated in response to different agonists and act independently to induce pyroptosis. in the context of il-1β/il-18 secretion, however, in vitro studies indicate that caspase-11 acts upstream of nlrp3 and caspase-1. by contrast, studying infection in vivo by the cytosol-invasive bacterium burkholderia thailandensis, we find that caspase-1 activity is required upstream of caspase-11 to control infection. caspase-1-activated il-18 induces ifn-γ to prime cas ... | 2015 | 26320999 |
| the effects of allium sativum extracts on biofilm formation and activities of six pathogenic bacteria. | garlic is considered a rich source of many compounds, which shows antimicrobial effects. the ability of microorganisms to adhere to both biotic and abiotic surfaces and to form biofilm is responsible for a number of diseases of chronic nature, demonstrating extremely high resistance to antibiotics. bacterial biofilms are complex communities of sessile microorganisms, embedded in an extracellular matrix and irreversibly attached to various surfaces. | 2015 | 26464762 |
| the cysteine dioxygenase homologue from pseudomonas aeruginosa is a 3-mercaptopropionate dioxygenase. | thiol dioxygenation is the initial oxidation step that commits a thiol to important catabolic or biosynthetic pathways. the reaction is catalyzed by a family of specific non-heme mononuclear iron proteins each of which is reported to react efficiently with only one substrate. this family of enzymes includes cysteine dioxygenase, cysteamine dioxygenase, mercaptosuccinate dioxygenase, and 3-mercaptopropionate dioxygenase. using sequence alignment to infer cysteine dioxygenase activity, a cysteine ... | 2015 | 26272617 |
| effect of the synthetic cannabinoid hu-210 on quorum sensing and on the production of quorum sensing-mediated virulence factors by vibrio harveyi. | bacterial populations communicate through the cell density-dependent mechanism of quorum sensing (qs). vibrio harveyi, one of the best studied model organisms for qs, was used to explore effects of the synthetic cannabinoid hu-210 on qs and different qs-regulated physiological processes in bacteria. | 2015 | 26264142 |
| effect of cinnamon oil on quorum sensing-controlled virulence factors and biofilm formation in pseudomonas aeruginosa. | quorum sensing (qs) is a system of stimuli and responses in bacterial cells governed by their population density, through which they regulate genes that control virulence factors and biofilm formation. despite considerable research on qs and the discovery of new antibiotics, qs-controlled biofilm formation by microorganisms in clinical settings has remained a problem because of nascent drug resistance, which requires screening of diverse compounds for anti-qs activities. cinnamon is a dietary ph ... | 2015 | 26263486 |
| synergistic combination of violacein and azoles that leads to enhanced killing of major human pathogenic dermatophytic fungi trichophyton rubrum. | superficial mycoses caused by dermatophytic fungi such as trichophyton rubrum represent the most common type of worldwide human infection affecting various keratinized tissues in our body such as the skin, hair, and nails, etc. the dermatophytic infection is a significant public health threat due to its persistent nature and high recurrence rates, and thus alternative treatments to cure this fungal infection are urgently required. the present study mainly focused on the synergistic activity of v ... | 2015 | 26322275 |
| evolution of cyclizing 5-aminolevulinate synthases in the biosynthesis of actinomycete secondary metabolites: outcomes for genetic screening techniques. | a combined approach, comprising pcr screening and genome mining, was used to unravel the diversity and phylogeny of genes encoding 5-aminolevulinic acid synthases (alass, hema gene products) in streptomycetes-related strains. in actinomycetes, these genes were believed to be directly connected with the production of secondary metabolites carrying the c5n unit, 2-amino-3-hydroxycyclopent-2-enone, with biological activities making them attractive for future use in medicine and agriculture. unlike ... | 2015 | 26300877 |
| violacein: properties and production of a versatile bacterial pigment. | violacein-producing bacteria, with their striking purple hues, have undoubtedly piqued the curiosity of scientists since their first discovery. the bisindole violacein is formed by the condensation of two tryptophan molecules through the action of five proteins. the genes required for its production, vioabcde, and the regulatory mechanisms employed have been studied within a small number of violacein-producing strains. as a compound, violacein is known to have diverse biological activities, incl ... | 2015 | 26339614 |
| potential of epigenetic therapies in the management of solid tumors. | cancer is a complex disease with both genetic and epigenetic origins. the growing field of epigenetics has contributed to our understanding of oncogenesis and tumor progression, and has allowed the development of novel therapeutic drugs. first-generation epigenetic inhibitor drugs have obtained modest clinical results in two types of hematological malignancy. second-generation epigenetic inhibitors are in development, and have intrinsically greater selectivity for their molecular targets. solid ... | 2015 | 26346546 |
| evaluation of cyp3a-mediated drug-drug interactions with romidepsin in patients with advanced cancer. | two multicenter, single-arm, single-infusion, open-label studies were conducted to evaluate the effect of ketoconazole (a strong cyp3a inhibitor) or rifampin (a strong cyp3a inducer) daily for 5 days on the pharmacokinetics (pk) and safety of romidepsin (8 mg/m(2) intravenous 4-hour infusion for the ketoconazole study or a 14 mg/m(2) intravenous 4-hour infusion for the rifampin study) in patients with advanced cancer. romidepsin coadministered with ketoconazole (400 mg) or rifampin (600 mg) was ... | 2015 | 26053962 |
| quorum sensing protects pseudomonas aeruginosa against cheating by other species in a laboratory coculture model. | many species of bacteria use a cell-cell communication system called quorum sensing (qs) to coordinate group activities. qs systems frequently regulate the production of exoproducts. some of these products, such as proteases, are "public goods" that are shared among the population and vulnerable to cheating by nonproducing members of the population. because the qs system of the opportunistic pathogen pseudomonas aeruginosa regulates several public goods, it can serve as a model for studying coop ... | 2015 | 26195596 |
| pseudomonas aeruginosa biofilm formation and persistence, along with the production of quorum sensing-dependent virulence factors, are disrupted by a triterpenoid coumarate ester isolated from dalbergia trichocarpa, a tropical legume. | recently, extracts of dalbergia trichocarpa bark have been shown to disrupt p. aeruginosa pao1 quorum sensing (qs) mechanisms, which are key regulators of virulence factor expression and implicated in biofilm formation. one of the active compounds has been isolated and identified as oleanolic aldehyde coumarate (oalc), a novel bioactive compound that inhibits the formation of p. aeruginosa pao1 biofilm and its maintenance as well as the expression of the las and rhl qs systems. consequently, the ... | 2015 | 26186595 |
| epigenetic activities of flavonoids in the prevention and treatment of cancer. | aberrant epigenetic modifications are described in an increasing number of pathological conditions, including neurodegenerative diseases, cardiovascular diseases, diabetes mellitus type 2, obesity and cancer. the general reversibility of epigenetic changes makes them an attractive and promising target e.g. in the treatment of cancer. thus, a growing number of epigenetically active compounds are currently tested in clinical trials for their therapeutic potential. interestingly, many phytochemical ... | 2015 | 26161152 |
| bioleaching of gold, copper and nickel from waste cellular phone pcbs and computer goldfinger motherboards by two aspergillus nigerstrains. | in an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment (weee), this research evaluated the bioleaching efficiency of gold (au), copper (cu) and nickel (ni) by two strains of aspergillus niger in the presence of gold-plated finger integrated circuits found in computer motherboards (gficms) and cellular phone printed circuit boards (pcbs). these three metals were analyzed for their commercial value and their diverse applications in the industr ... | 2015 | 26413051 |
| targeting histone deacetylases in diseases: where are we? | epigenetic inactivation of pivotal genes involved in cell growth is a hallmark of human pathologies, in particular cancer. histone acetylation balance obtained through opposing actions of histone deacetylases (hdacs) and histone acetyltransferases is one epigenetic mechanism controlling gene expression and is, thus, associated with disease etiology and progression. interfering pharmacologically with hdac activity can correct abnormalities in cell proliferation, migration, vascularization, and de ... | 2015 | 24382114 |
| precise metabolic engineering of carotenoid biosynthesis in escherichia coli towards a low-cost biosensor. | micronutrient deficiencies, including zinc deficiency, are responsible for hundreds of thousands of deaths annually. a key obstacle to allocating scarce treatment resources is the ability to measure population blood micronutrient status inexpensively and quickly enough to identify those who most need treatment. this paper develops a metabolically engineered strain of escherichia coli to produce different colored pigments (violacein, lycopene, and β-carotene) in response to different extracellula ... | 2015 | 26141149 |
| pseudomonas aeruginosa biofilm response and resistance to cold atmospheric pressure plasma is linked to the redox-active molecule phenazine. | pseudomonas aeruginosa is an important opportunistic pathogen displaying high antibiotic resistance. its resistance is in part due to its outstanding ability to form biofilms on a range of biotic and abiotic surfaces leading to difficult-to-treat, often long-term infections. cold atmospheric plasma (cap) is a new, promising antibacterial treatment to combat antibiotic-resistant bacteria. plasma is ionized gas that has antibacterial properties through the generation of a mix of reactive oxygen an ... | 2015 | 26114428 |
| violacein as a genetically-controlled, enzymatically amplified and photobleaching-resistant chromophore for optoacoustic bacterial imaging. | there is growing interest in genetically expressed reporters for in vivo studies of bacterial colonization in the context of infectious disease research, studies of the bacterial microbiome or cancer imaging and treatment. to empower non-invasive high-resolution bacterial tracking with deep tissue penetration, we herein use the genetically controlled biosynthesis of the deep-purple pigment violacein as a photobleaching-resistant chromophore label for in vivo optoacoustic (photoacoustic) imaging ... | 2015 | 26091543 |
| a new meroditerpene and a new tryptoquivaline analog from the algicolous fungus neosartorya takakii kufc 7898. | a new meroditerpene sartorenol (1), a new natural product takakiamide (2) and a new tryptoquivaline analog (3) were isolated, together with nine known compounds, including aszonapyrone a, chevalone b, aszonalenin, acetylaszonalenin, 3'-(4-oxoquinazolin-3-yl) spiro[1h-indole-3,5'-oxolane]-2,2'-dione, tryptoquivalines l, f and h, and the isocoumarin derivative, 6-hydroxymellein, from the ethyl acetate extract of the culture of the algicolous fungus neosartorya takakii kufc 7898. the structures of ... | 2015 | 26082989 |
| hif-1α pathway: role, regulation and intervention for cancer therapy. | hypoxia-inducible factor-1 (hif-1) has been recognized as an important cancer drug target. many recent studies have provided convincing evidences of strong correlation between elevated levels of hif-1 and tumor metastasis, angiogenesis, poor patient prognosis as well as tumor resistance therapy. it was found that hypoxia (low o2 levels) is a common character in many types of solid tumors. as an adaptive response to hypoxic stress, hypoxic tumor cells activate several survival pathways to carry o ... | 2015 | 26579469 |
| violacein induces cell death by triggering mitochondrial membrane hyperpolarization in vitro. | violacein is a purple pigment from chromobacterium violaceum that possesses diverse biological and pharmacological properties. among these, pro-oxidant and antioxidant activities have been suggested. however, the cytotoxic mechanisms induced by violacein are poorly understood and the improvement in knowledge regarding these cell death mechanisms will be useful to develop new therapeutic approaches. considering this, in our work, we investigated the pro-oxidant effects of violacein in non-tumor ( ... | 2015 | 26048053 |
| progress and challenges in the use of latent hiv-1 reactivating agents. | highly active antiretroviral therapy (haart) can effectively suppress the replication of human immunodeficiency virus-1 (hiv-1) and block disease progression. however, chronic hiv-1 infection remains incurable due to the persistence of a viral reservoir, including the transcriptionally silent provirus in cd4(+) memory t cells and the sanctuary sites that are inaccessible to drugs. reactivation and the subsequent elimination of latent virus through virus-specific cytotoxic effects or host immune ... | 2015 | 26027656 |
| potential use of histone deacetylase inhibitors in cancer therapy. | epigenetics is a branch of science that focuses on mechanisms related to control and modification of expression of genetic material without any changes to its sequences. such mechanisms include post-translational modifications of histones. it is widely known that carcinogenesis is related to hypoacetylation of genes that influence apoptosis, the cell cycle, cell signaling, the immunologic response, angiogenesis and occurrence of metastasis. currently conducted research focuses on several strateg ... | 2015 | 26843838 |
| sub-mics of mentha piperita essential oil and menthol inhibits ahl mediated quorum sensing and biofilm of gram-negative bacteria. | bacterial quorum sensing (qs) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. bioactive plant extract/compounds inhibiting qs regulated gene expression may be a potential candidate as antipathogenic drug. in this study anti-qs activity of peppermint (mentha piperita) oil was first tested using the chromobacterium violaceum cvo26 biosensor. further, the findings of the present investigation rev ... | 2015 | 26029178 |
| versatile genetic assembly system (vegas) to assemble pathways for expression in s. cerevisiae. | we have developed a method for assembling genetic pathways for expression in saccharomyces cerevisiae. our pathway assembly method, called vegas (versatile genetic assembly system), exploits the native capacity of s. cerevisiae to perform homologous recombination and efficiently join sequences with terminal homology. in the vegas workflow, terminal homology between adjacent pathway genes and the assembly vector is encoded by 'vegas adapter' (va) sequences, which are orthogonal in sequence with r ... | 2015 | 25956652 |
| violacein treatment modulates acute and chronic inflammation through the suppression of cytokine production and induction of regulatory t cells. | inflammation is a necessary process to control infection. however, exacerbated inflammation, acute or chronic, promotes deleterious effects in the organism. violacein (viola), a quorum sensing metabolite from the gram-negative bacterium chromobacterium violaceum, has been shown to protect mice from malaria and to have beneficial effects on tumors. however, it is not known whether this drug possesses anti-inflammatory activity. in this study, we investigated whether viola administration is able t ... | 2015 | 25938431 |
| exposure to an extremely low-frequency electromagnetic field only slightly modifies the proteome of chromobacterium violaceumatcc 12472. | several studies of the physiological responses of different organisms exposed to extremely low-frequency electromagnetic fields (elf-emf) have been described. in this work, we report the minimal effects of in situ exposure to elf-emf on the global protein expression of chromobacterium violaceum using a gel-based proteomic approach. the protein expression profile was only slightly altered, with five differentially expressed proteins detected in the exposed cultures; two of these proteins (dna-bin ... | 2015 | 26273227 |
| trigonella foenum-graceum (seed) extract interferes with quorum sensing regulated traits and biofilm formation in the strains of pseudomonas aeruginosa and aeromonas hydrophila. | trigonella foenum-graecum l. (fenugreek) is an important plant of the leguminosae family known to have medicinal properties. however, fraction based antiquorum sensing and antibiofilm activities have not been reported from this plant. in the present study t. foenum-graecum seed extract was sequentially fractionated and sub-mics were tested for above activities. the methanol fraction of the extract demonstrated significant inhibition of ahl regulated virulence factors: protease, lasb elastase, py ... | 2015 | 26000026 |
| biofilm formation and quorum-sensing-molecule production by clinical isolates of serratia liquefaciens. | serratia spp. are opportunistic human pathogens responsible for an increasing number of nosocomial infections. however, little is known about the virulence factors and regulatory circuits that may enhance the establishment and long-term survival of serratia liquefaciens in the hospital environment. in this study, two reporter strains, chromobacterium violaceum cv026 and vir24, and high-resolution triple-quadrupole liquid chromatography-mass spectrometry (lc-ms) were used to detect and to quantif ... | 2015 | 25746999 |
| chemical composition and disruption of quorum sensing signaling in geographically diverse united states propolis. | propolis or bee glue has been used for centuries for various purposes and is especially important in human health due to many of its biological and pharmacological properties. in this work we showed quorum sensing inhibitory (qsi) activity of ten geographically distinct propolis samples from the united states using the acyl-homoserine lactone- (ahl-) dependent chromobacterium violaceum strain cv026. based on gc-ms chemical profiling the propolis samples can be classified into several groups that ... | 2015 | 25960752 |
| biosynthesis of the antifungal haterumalide, oocydin a, in serratia, and its regulation by quorum sensing, rpos and hfq. | polyketides represent an important class of bioactive natural products with a broad range of biological activities. we identified recently a large trans-acyltransferase (at) polyketide synthase gene cluster responsible for the biosynthesis of the antifungal, anti-oomycete and antitumor haterumalide, oocydin a (ooc). using genome sequencing and comparative genomics, we show that the ooc gene cluster is widespread within biocontrol and phytopathogenic strains of the enterobacteria, serratia and di ... | 2015 | 25753587 |
| structural and mechanistic roles of novel chemical ligands on the sdia quorum-sensing transcription regulator. | bacteria engage in chemical signaling, termed quorum sensing (qs), to mediate intercellular communication, mimicking multicellular organisms. the luxr family of qs transcription factors regulates gene expression, coordinating population behavior by sensing endogenous acyl homoserine lactones (ahls). however, some bacteria (such as escherichia coli) do not produce ahls. these luxr orphans sense exogenous ahls but also regulate transcription in the absence of ahls. importantly, this ahl-independen ... | 2015 | 25827420 |
| violacein induces p44/42 mitogen-activated protein kinase-mediated solid tumor cell death and inhibits tumor cell migration. | microbial secondary metabolites have emerged as alternative novel drugs for the treatment of human cancers. violacein, a purple pigment produced by chromobacterium violaceum, was investigated in the present study for its anti-tumor properties in tumor cell lines. clinically applicable concentrations of violacein were demonstrated to inhibit the proliferative capacity of tumor cell lines according to a crystal violet proliferation assay. the underlying mechanism was the promotion of apoptotic cel ... | 2015 | 25816226 |
| the formation of biofilms by pseudomonas aeruginosa: a review of the natural and synthetic compounds interfering with control mechanisms. | p. aeruginosa is an opportunistic pathogenic bacterium responsible for both acute and chronic infections. beyond its natural resistance to many drugs, its ability to form biofilm, a complex biological system, renders ineffective the clearance by immune defense systems and antibiotherapy. the objective of this report is to provide an overview (i) on p. aeruginosa biofilm lifestyle cycle, (ii) on the main key actors relevant in the regulation of biofilm formation by p. aeruginosa including qs syst ... | 2015 | 25866808 |
| new therapies for dedifferentiated papillary thyroid cancer. | the number of thyroid cancers is increasing. standard treatment usually includes primary surgery, thyroid-stimulating hormone suppressive therapy, and ablation of the thyroid remnant with radioactive iodine (rai). despite the generally good prognosis of thyroid carcinoma, about 5% of patients will develop metastatic disease, which fails to respond to rai, exhibiting a more aggressive behavior. the lack of specific, effective and well-tolerated drugs, the scarcity of data about the association of ... | 2015 | 25789503 |
| genome mining reveals unlocked bioactive potential of marine gram-negative bacteria. | antibiotic resistance in bacteria spreads quickly, overtaking the pace at which new compounds are discovered and this emphasizes the immediate need to discover new compounds for control of infectious diseases. terrestrial bacteria have for decades been investigated as a source of bioactive compounds leading to successful applications in pharmaceutical and biotech industries. marine bacteria have so far not been exploited to the same extent; however, they are believed to harbor a multitude of nov ... | 2015 | 25879706 |
| relative frequency, characteristics, and antimicrobial susceptibility patterns of vibrio spp., aeromonas spp., chromobacterium violaceum, and shewanella spp. in the northern territory of australia, 2000-2013. | vibrio, aeromonas, chromobacterium violaceum, and shewanella (vacs) are water-associated gram-negative organisms that can cause a variety of infections. the frequency, patient characteristics, and antimicrobial susceptibilities for 468 isolates from 442 patients from the northern territory were reviewed. aeromonas spp. (312 of 468; 67%) were most commonly isolated followed by vibrio spp. (71 of 468; 15%), shewanella spp. (61 of 468; 13%), and c. violaceum (24 of 468; 5%). a strong male predomina ... | 2015 | 25548380 |
| histone deacetylase inhibitors in clinical studies as templates for new anticancer agents. | histone dacetylases (hdacs) are a group of enzymes that remove acetyl groups from histones and regulate expression of tumor suppressor genes. they are implicated in many human diseases, especially cancer, making them a promising therapeutic target for treatment of the latter by developing a wide variety of inhibitors. hdac inhibitors interfere with hdac activity and regulate biological events, such as cell cycle, differentiation and apoptosis in cancer cells. as a result, hdac inhibitor-based th ... | 2015 | 25738536 |
| 6-gingerol reduces pseudomonas aeruginosa biofilm formation and virulence via quorum sensing inhibition. | pseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors via quorum sensing (qs). interfering with normal qs interactions between signal molecules and their cognate receptors is a developing strategy for attenuating its virulence. here we tested the hypothesis that 6-gingerol, a pungent oil of fresh ginger, reduces biofilm formation and virulence by antagonistically binding to p. aeruginosa qs receptors. in silico studies demonstrated molecul ... | 2015 | 25728862 |
| pityriazepin and other potent ahr ligands isolated from malassezia furfur yeast. | malassezia furfur yeast strains isolated from diseased human skin preferentially biosynthesize indole alkaloids which can be detected in the human skin and are highly potent activators of the aryl hydrocarbon receptor (ahr) and ahr-dependent gene expression. chemical analysis of an etoac extract of a m. furfur strain obtained from diseased human skin and grown on l-tryptophan agar revealed several known ahr active tryptophan metabolites along with a previously unidentified compound, pityriazepin ... | 2015 | 25721496 |
| augmenting antitumor immune responses with epigenetic modifying agents. | epigenetic silencing of immune-related genes is a striking feature of the cancer genome that occurs in the process of tumorigenesis. this phenomena impacts antigen processing and antigen presentation by tumor cells and facilitates evasion of immunosurveillance. further modulation of the tumor microenvironment by altered expression of immunosuppressive cytokines impairs antigen-presenting cells and cytolytic t-cell function. the potential reversal of immunosuppression by epigenetic modulation is ... | 2015 | 25699047 |
| development of potent inhibitors of pyocyanin production in pseudomonas aeruginosa. | the development of new approaches for the treatment of antimicrobial-resistant infections is an urgent public health priority. the pseudomonas aeruginosa pathogen, in particular, is a leading source of infection in hospital settings, with few available treatment options. in the context of an effort to develop antivirulence strategies to combat bacterial infection, we identified a series of highly effective small molecules that inhibit the production of pyocyanin, a redox-active virulence factor ... | 2015 | 25597392 |
| in vitro cytotoxic effects of gold nanoparticles coated with functional acyl homoserine lactone lactonase protein from bacillus licheniformis and their antibiofilm activity against proteus species. | n-acylated homoserine lactonases are known to inhibit the signaling molecules of the biofilm-forming pathogens. in this study, gold nanoparticles were coated with n-acylated homoserine lactonase proteins (aiia aunps) purified from bacillus licheniformis. the aiia aunps were characterized by uv-visible spectra, fourier transform infrared spectroscopy (ftir), transmission electron microscopy (tem), and x-ray diffraction (xrd). the synthesized aiia aunps were found to be spherical in shape and 10 t ... | 2015 | 25403677 |
| prodigiosin and its potential applications. | since a decade, there has been a strong consumer demand for more natural products. this has augmented inclination towards substitution of synthetic colorants with natural pigments. natural pigments not only have the capacity to increase the marketability of products, they also demonstrate valuable biological activities as antioxidants and anticancer agents. there is a long history of exploitation of natural products produced by bacteria as sources of pharmaceutically important, bioactive compoun ... | 2015 | 26344956 |
| role of l-alanine for redox self-sufficient amination of alcohols. | in white biotechnology biocatalysis represents a key technology for chemical functionalization of non-natural compounds. the plasmid-born overproduction of an alcohol dehydrogenase, an l-alanine-dependent transaminase and an alanine dehydrogenase allows for redox self-sufficient amination of alcohols in whole cell biotransformation. here, conditions to optimize the whole cell biocatalyst presented in (bioorg med chem 22:5578-5585, 2014), and the role of l-alanine for efficient amine functionaliz ... | 2015 | 25612558 |
| high crude violacein production from glucose by escherichia coli engineered with interactive control of tryptophan pathway and violacein biosynthetic pathway. | as bacteria-originated crude violacein, a natural indolocarbazole product, consists of violacein and deoxyviolacein, and can potentially be a new type of natural antibiotics, the reconstruction of an effective metabolic pathway for crude violacein (violacein and deoxyviolacein mixture) synthesis directly from glucose in escherichia coli was of importance for developing industrial production process. | 2015 | 25592762 |
| moml, a novel marine-derived n-acyl homoserine lactonase from muricauda olearia. | gram-negative bacteria use n-acyl homoserine lactones (ahls) as quorum sensing (qs) signaling molecules for interspecies communication, and ahl-dependent qs is related with virulence factor production in many bacterial pathogens. quorum quenching, the enzymatic degradation of the signaling molecule, would attenuate virulence rather than kill the pathogens, and thereby reduce the potential for evolution of drug resistance. in a previous study, we showed that muricauda olearia th120, belonging to ... | 2015 | 25398866 |
| chronic granulomatous disease. | | 2015 | 25657928 |
| anti-quorum sensing potential of adenanthera pavonina. | quorum sensing (qs) in pseudomonas aeruginosa plays a key role in virulence factor production, biofilm formation and antimicrobial resistance. because of emerging antimicrobial resistance in p. aeruginosa, there is a need to find an alternate nonantibiotic agent for the control of infections caused by this organism. | 2015 | 25598643 |
| a diketopiperazine factor from rheinheimera aquimaris qsi02 exhibits anti-quorum sensing activity. | an ethyl acetate (etoac) extract isolated from the marine bacterium, rheinheimera aquimaris qsi02, was found to exhibit anti-quorum sensing (anti-qs) activity. a subsequent bioassay-guided isolation protocol led to the detection of an active diketopiperazine factor, cyclo(trp-ser). biosensor assay data showed that the minimum inhibitory concentration (mic) of cyclo(trp-ser) ranged from 3.2 mg/ml to 6.4 mg/m for several microorganisms, including escherichia coli, chromobacterium violaceum cv026, ... | 2016 | 28000767 |
| bacillus sp. qsi-1 modulate quorum sensing signals reduce aeromonas hydrophila level and alter gut microbial community structure in fish. | quorum sensing (qs) is a cell density dependent process that enables bacteria to communicate with each other based on the production, secretion and sensing of the auto-inducer molecules and then subsequently regulate virulence associated gene expression. interrupting quorum sensing may represent a novel alternative approach to combat bacterial pathogen. several bacteria can produce quorum quenching (qq) enzymes. however, the role of qq bacteria in shaping the microbiota and the level of n-acyl-h ... | 2016 | 28018866 |
| bacteremia caused by a rare pathogen - chromobacterium violaceum: a case report from nepal. | chromobacterium violaceum is a gram negative saprophytic bacterium, prevalent in tropical and subtropical climates. infections caused by c. violaceum are very uncommon, yet it can cause severe systemic infections with higher mortality when entered into the bloodstream through open wound. a case of symptomatic bacteremia in a woman caused by c. violaceum was identified recently at a tertiary care teaching hospital in nepal. timely diagnosis by microbiological methods and rapid administration of a ... | 2016 | 27980433 |
| biogenic synthesis of zinc oxide nanostructures from nigella sativa seed: prospective role as food packaging material inhibiting broad-spectrum quorum sensing and biofilm. | bacterial spoilage of food products is regulated by density dependent communication system called quorum sensing (qs). qs control biofilm formation in numerous food pathogens and biofilms formed on food surfaces act as carriers of bacterial contamination leading to spoilage of food and health hazards. agents inhibiting or interfering with bacterial qs and biofilm are gaining importance as a novel class of next-generation food preservatives/packaging material. in the present study, zinc nanostruc ... | 2016 | 27917856 |
| attenuation of quorum sensing regulated virulence of pectobacterium carotovorum subsp. carotovorum through an ahl lactonase produced by lysinibacillus sp. gs50. | quorum sensing (qs) is a mechanism in which gram negative bacterial pathogens sense their population density through acyl homoserine lactones (ahls) and regulate the expression of virulence factors. enzymatic degradation of ahls by lactonases, known as quorum quenching (qq), is thus a potential strategy for attenuating qs regulated bacterial infections. we characterised the qq activity of soil isolate lysinibacillus sp. gs50 and explored its potential for controlling bacterial soft rot of crop p ... | 2016 | 27911925 |
| plant phenolic volatiles inhibit quorum sensing in pectobacteria and reduce their virulence by potential binding to expi and expr proteins. | quorum sensing (qs) is a population density-dependent regulatory system in bacteria that couples gene expression to cell density through accumulation of diffusible signaling molecules. pectobacteria are causal agents of soft rot disease in a range of economically important crops. they rely on qs to coordinate their main virulence factor, production of plant cell wall degrading enzymes (pcwdes). plants have evolved an array of antimicrobial compounds to anticipate and cope with pathogens, of whic ... | 2016 | 27905512 |
| synthesis of st7612aa1, a novel oral hdac inhibitor, via radical
thioacetic acid addition. | in the expanding field of anticancer drugs, hdac inhibitors are playing an increasingly important role. to date, four/five hdac inhibitors have been approved by fda. all these compounds fit the widely accepted hdac inhibitors pharmacophore model characterized by a cap group, a linker chain and a zinc binding group (zbg), able to bind the zn(2+) ion in a pocket of the hdac active site. romidepsin, a natural compound, is the only thiol derivative. we have selected a new class of synthetic hdac inh ... | 2016 | 27917100 |
| functional characterization of triclosan-resistant enoyl-acyl-carrier protein reductase (fabv) in pseudomonas aeruginosa. | pseudomonas aeruginosa is extremely resistant to triclosan. previous studies have shown that p. aeruginosa encodes a triclosan-resistant enoyl-acyl-carrier protein reductase (enr), fabv, and that deletion of fabv causes p. aeruginosa to be extremely sensitive to triclosan. in this report, we complemented a p. aeruginosa fabv deletion strain with several triclosan-resistant enr encoding genes, including vibrio cholerae fabv, bacillus subtilis fabl and enterococcus faecalis fabk. all complemented ... | 2016 | 27965638 |
| a retrospective analysis of melioidosis in cambodian children, 2009-2013. | melioidiosis, infection by burkholderia pseudomallei, is an important but frequently under-recognised cause of morbidity and mortality in southeast asia and elsewhere in the tropics. data on the epidemiology of paediatric melioidosis in cambodia are extremely limited. | 2016 | 27871233 |
| the chromobacterium violaceum arsr arsenite repressor exerts tighter control on its cognate promoter than the escherichia coli system. | environmental bacteria are endowed with several regulatory systems that have potential applications in biotechnology. in this report, we characterize the arsenic biosensing features of the ars response system from chromobacterium violaceum in the heterologous host escherichia coli. we show that the native pars/arsr system of c. violaceum outperforms the chromosomal ars copy of e. coli when exposed to micromolar concentrations of arsenite. to understand the molecular basis of this phenomenon, we ... | 2016 | 27917165 |
| the pharmacological potential of non-ribosomal peptides from marine sponge and tunicates. | marine biodiversity is recognized by a wide and unique array of fascinating structures. the complex associations of marine microorganisms, especially with sponges, bryozoans, and tunicates, make it extremely difficult to define the biosynthetic source of marine natural products or to deduce their ecological significance. marine sponges and tunicates are important source of novel compounds for drug discovery and development. majority of these compounds are nitrogen containing and belong to non-ri ... | 2016 | 27826240 |
| a quadruplex real-time pcr assay for the rapid detection and differentiation of the most relevant members of the b. pseudomallei complex: b. mallei, b. pseudomallei, and b. thailandensis. | the burkholderia pseudomallei complex classically consisted of b. mallei, b. pseudomallei, and b. thailandensis, but has now expanded to include b. oklahomensis, b. humptydooensis, and three unassigned burkholderia clades. methods for detecting and differentiating the b. pseudomallei complex has been the topic of recent research due to phenotypic and genotypic similarities of these species. b. mallei and b. pseudomallei are recognized as cdc tier 1 select agents, and are the causative agents of ... | 2016 | 27736903 |
| identification of genes involved in indole-3-acetic acid biosynthesis by gluconacetobacter diazotrophicus pal5 strain using transposon mutagenesis. | gluconacetobacter diazotrophicus is a beneficial nitrogen-fixing endophyte found in association with sugarcane plants and other important crops. beneficial effects of g. diazotrophicus on sugarcane growth and productivity have been attributed to biological nitrogen fixation process and production of phytohormones especially indole-3-acetic acid (iaa); however, information about the biosynthesis and function of iaa in g. diazotrophicus is still scarce. therefore, the aim of this work was to ident ... | 2016 | 27774087 |
| histone deacetylase inhibitors for cancer therapy: an evolutionarily ancient resistance response may explain their limited success. | histone deacetylase inhibitors (hdaci) are in clinical trials against a variety of cancers. despite early successes, results against the more common solid tumors have been mixed. how is it that so many cancers, and most normal cells, tolerate the disruption caused by hdaci-induced protein hyperacetylation? and why are a few cancers so sensitive? here we discuss recent results showing that human cells mount a coordinated transcriptional response to hdaci that mitigates their toxic effects. we pre ... | 2016 | 27717012 |
| chromobacterium violaceum septicaemia and urinary tract infection: case reports from a tertiary care hospital in south india. | chromobacterium violaceum is a gram negative oxidase positive bacillus that causes human infections infrequently. it is a normal inhabitant of soil and stagnant water of the tropical and subtropical areas. in humans, it can cause infections ranging from life threatening sepsis with metastatic abscesses to skin infections and urinary tract infections. the organism is notoriously resistant to most cephalosporins and ampicillin. fluoroquinolones and aminoglycosides show good in vitro susceptibility ... | 2016 | 27747113 |
| ptra is functionally intertwined with gacs in regulating the biocontrol activity of pseudomonas chlororaphis pa23. | in vitro inhibition of the fungal pathogen sclerotinia sclerotiorum by pseudomonas chlororaphis pa23 is reliant upon a lysr-type transcriptional regulator (lttr) called ptra. in the current study, we show that sclerotinia stem rot and leaf infection are significantly increased in canola plants inoculated with the ptra-mutant compared to the wild type, establishing ptra as an essential regulator of pa23 biocontrol. lttrs typically regulate targets that are upstream of and divergently transcribed ... | 2016 | 27713742 |