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Sample records for carbazole degrader pseudomonas

  1. Magnetite nanoparticle aided immobilization of Pseudomonas sp. GBS.5 for carbazole degradation

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    Poorva Mehndiratta

    2014-12-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Pseudomonas sp. GBS.5 is a newly isolated biosurfactant producing and carbazole degrading bacterium. In the present study, this bacterium was coated with magnetite nanoparticles, synthesized using co-precipitation method. Scanning electron microscopy (SEM studies confirmed the coating of the bacterial surface with these nanoparticles. Degradation activity of the coated cells obtained was 1.4 ppm/min as compared to 0.32 ppm/min for free cells and could be reused for five different cycles. These results indicate that magnetite nanoparticle can be efficiently used for the immobilization of biosurfactant producing bacteria involved in the degradation of polyaromatic compounds.

  2. Carbazole-degradative IncP-7 plasmid pCAR1.2 is structurally unstable in Pseudomonas fluorescens Pf0-1, which accumulates catechol, the intermediate of the carbazole degradation pathway.

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    Takahashi, Yurika; Shintani, Masaki; Li, Li; Yamane, Hisakazu; Nojiri, Hideaki

    2009-06-01

    We determined the effect of the host on the function and structure of the nearly identical IncP-7 carbazole-degradative plasmids pCAR1.1 and pCAR1.2. We constructed Pseudomonas aeruginosa PAO1(pCAR1.2) and P. fluorescens Pf0-1Km(pCAR1.2) and compared their growth on carbazole- and succinate-containing media with that of P. putida KT2440(pCAR1.1). We also assessed the stability of the genetic structures of the plasmids in each of the three hosts. Pf0-1Km(pCAR1.2) showed dramatically delayed growth when carbazole was supplied as the sole carbon source, while the three strains grew at nearly the same rate on succinate. Among the carbazole-grown Pf0-1Km(pCAR1.2) cells, two types of deficient strains appeared and dominated the population; such dominance was not observed in the other two strains or for succinate-grown Pf0-1Km(pCAR1.2). Genetic analysis showed that the two deficient strains possessed pCAR1.2 derivatives in which the carbazole-degradative car operon was deleted or its regulatory gene, antR, was deleted by homologous recombination between insertion sequences. From genomic information and quantitative reverse transcription-PCR analyses of the genes involved in carbazole mineralization by Pf0-1Km(pCAR1.2), we found that the cat genes on the chromosome of Pf0-1Km, which are necessary for the degradation of catechol (a toxic intermediate in the carbazole catabolic pathway), were not induced in the presence of carbazole. The resulting accumulation of catechol may have enabled the strain that lost its carbazole-degrading ability to have overall higher fitness than the wild-type strain. These results suggest that the functions of the chromosomal genes contributed to the selection of plasmid derivatives with altered structures.

  3. Cloning and expression of meta-cleavage enzyme (CarB of carbazole degradation pathway from Pseudomonas stutzeri

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    Ariane Leites Larentis

    2005-06-01

    Full Text Available In this work, the 1082bp PCR product corresponding to carBaBb genes that encode the heterotetrameric enzyme 2'-aminobiphenyl-2,3-diol 1,2-dioxygenase (CarB, involved in the Pseudomonas stutzeri ATCC 31258 carbazole degradation pathway, was cloned using the site-specific recombination system. Recombinant clones were confirmed by PCR, restriction enzyme digestion and sequencing. CarB dioxygenase was expressed in high levels and in active form in Escherichia coli BL21-SI using the His-tagged expression vector pDEST TM17 and salt induction for 4h.Carbazol e seus derivados são compostos nitrogenados aromáticos, presentes comumente em petróleo e potencialmente poluentes. A rota de biodegradação de carbazol a ácido antranílico em Pseudomonas sp. é composta por três enzimas responsáveis, respectivamente, pelas reações de dioxigenação angular, meta-clivagem e hidrólise. A segunda enzima da rota, 2'-aminobifenil-2,3-diol 1,2-dioxigenase (CarB, codificada por dois genes (carBa e carBb, é um heterotetrâmero com atividade catalítica na quebra do anel catecol do susbtrato na posição meta. Neste trabalho, foi clonado o produto de PCR de 1082pb correspondente aos genes carBaBb da bactéria degradadora de carbazol Pseudomonas stutzeri ATCC 31258. A estratégia de clonagem empregada foi a de recombinação sítio-específica e a construção dos plasmídeos foi confirmada por PCR, digestão com enzima de restrição e seqüenciamento. A enzima ativa foi expressa em altas concentrações em vetor pDEST TM17 com cauda de histidina e promotor T7 em Escherichia coli BL21-SI com indução por NaCl durante 4h.

  4. DNA rearrangement has occurred in the carbazole-degradative plasmid pCAR1 and the chromosome of its unsuitable host, Pseudomonas fluorescens Pf0-1.

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    Shintani, Masaki; Matsumoto, Takashi; Yoshikawa, Hirofumi; Yamane, Hisakazu; Ohkuma, Moriya; Nojiri, Hideaki

    2011-12-01

    The carbazole-degradative plasmid pCAR1 carries the class II transposon Tn4676, which contains the car and ant genes, essential for conversion of carbazole into anthranilate, and anthranilate into catechol, respectively. In our previous study, DNA rearrangements in pCAR1 were frequently detected in the host Pseudomonas fluorescens Pf0-1 in the presence of carbazole, resulting in the improvement of host survivability. Several Pf0-1 mutants harbouring pCAR1 were isolated, and deletion of DNA in the plasmid ant gene was found. Here, we compared genome sequences of the parent strain Pf0-1L(pCAR1::rfp) and one of its mutants, 5EP83, to assess whether other DNA rearrangements occurred in either the plasmid or the host chromosome. We found transposition of Tn4676 into the 5EP83 chromosome. In addition, ISPre1 had transposed into the car gene intergenic region on the pCAR1-derivative plasmid of 5EP83, which inhibited car transcription. As a result of these transpositions, 5EP83 was able to metabolize carbazole due to the Tn4676 on its chromosome, although the car genes on its plasmid were non-functional. We also found that one copy of duplicate carAa genes had been deleted, and that ISPre4 had transposed into both the host chromosome and the plasmid. Our findings suggest that Pf0-1 harbouring pCAR1 is subjected to DNA rearrangements not only on the plasmid but also on its chromosome in the presence of carbazole.

  5. Carbazole degradation in the soil microcosm by tropical bacterial strains

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    Lateef B. Salam

    2015-01-01

    Full Text Available In a previous study, three bacterial strains isolated from tropical hydrocarbon-contaminated soils and phylogenetically identified as Achromobacter sp. strain SL1, Pseudomonassp. strain SL4 and Microbacterium esteraromaticum strain SL6 displayed angular dioxygenation and mineralization of carbazole in batch cultures. In this study, the ability of these isolates to survive and enhance carbazole degradation in soil were tested in field-moist microcosms. Strain SL4 had the highest survival rate (1.8 x 107 cfu/g after 30 days of incubation in sterilized soil, while there was a decrease in population density in native (unsterilized soil when compared with the initial population. Gas chromatographic analysis after 30 days of incubation showed that in sterilized soil amended with carbazole (100 mg/kg, 66.96, 82.15 and 68.54% were degraded by strains SL1, SL4 and SL6, respectively, with rates of degradation of 0.093, 0.114 and 0.095 mg kg−1 h−1. The combination of the three isolates as inoculum in sterilized soil degraded 87.13% carbazole at a rate of 0.121 mg kg−1 h−1. In native soil amended with carbazole (100 mg/kg, 91.64, 87.29 and 89.13% were degraded by strains SL1, SL4 and SL6 after 30 days of incubation, with rates of degradation of 0.127, 0.121 and 0.124 mg kg−1h−1, respectively. This study successfully established the survivability (> 106 cfu/g detected after 30 days and carbazole-degrading ability of these bacterial strains in soil, and highlights the potential of these isolates as seed for the bioremediation of carbazole-impacted environments.

  6. Aflatoxin B₁ degradation by a Pseudomonas strain.

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    Sangare, Lancine; Zhao, Yueju; Folly, Yawa Minnie Elodie; Chang, Jinghua; Li, Jinhan; Selvaraj, Jonathan Nimal; Xing, Fuguo; Zhou, Lu; Wang, Yan; Liu, Yang

    2014-10-23

    Aflatoxin B1 (AFB1), one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB₁, AFB₂ and AFM₁ by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB) medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB₁ effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn²⁺ and Cu²⁺ were activators for AFB1 degradation, however, ions Mg²⁺, Li⁺, Zn²⁺, Se²⁺, Fe³⁺ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB₁ was metabolized to degradation products with chemical properties different from that of AFB₁. The results indicated that the degradation of AFB₁ by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin.

  7. Zearalenone degradation by two Pseudomonas strains from soil.

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    Tan, Hui; Hu, Yanchun; He, Jie; Wu, Lei; Liao, Fei; Luo, Biao; He, Yajun; Zuo, Zhicai; Ren, Zhihua; Zhong, Zhijun; Peng, Guangneng; Deng, Junliang

    2014-11-01

    This study describes the screening of soil bacteria for their capability to degrade zearalenone (ZEN), employing an enrichment technique in which ZEN is used as the sole carbon source. Two isolates that were able to degrade ZEN belonged to the genus Pseudomonas according to biochemical characterization and 16S rRNA gene sequence and were named as Pseudomonas alcaliphila TH-C1 and Pseudomonas plecoglossicida TH-L1, respectively. The results showed that the degradation rates of P. alcaliphila TH-C1 and P. plecoglossicida TH-L1 for ZEN (2 μg/ml) were 68 ± 0.85 % and 57 ± 0.73%, when incubated for 72 h at 30 °C in a rotary shaker (160 rpm) and detected by high-performance liquid chromatograms (HPLC). These results suggest that the two Pseudomonas strains are new bacterial resource for degrading ZEN and can provide a new approach for the detoxification of ZEN.

  8. Microbial degradation of pyridine using Pseudomonas sp. and isolation of plasmid responsible for degradation.

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    Mohan, S Venkata; Sistla, Srinivas; Guru, R Kumar; Prasad, K Krishna; Kumar, C Suresh; Ramakrishna, S V; Sarma, P N

    2003-01-01

    Pseudomonas (PI2) capable of degrading pyridine was isolated from the mixed population of the activated sludge unit which was being used for treating complex effluents, the strain was characterized. Aerobic degradation of pyridine was studied with the isolated strain and the growth parameters were evaluated. Pyridine degradation was further conformed by chromatography (HPLC) analysis. The process parameters like biomass growth and dissolved oxygen consumption were monitored during pyridine degradation. In order to conform with the plasmid capability to degrade pyridine, the requisite plasmid was isolated and transferred to DH 5alpha Escherichia coli. The subsequent biodegradation studies revealed the ability of the transformed plasmid capability to degrade the pyridine.

  9. Degradation of parabens by Pseudomonas beteli and Burkholderia latens.

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    Amin, Aeshna; Chauhan, Sateesh; Dare, Manish; Bansal, Arvind Kumar

    2010-06-01

    p-Hydroxybenzoic acid esters (parabens) are commonly used antimicrobial preservatives in pharmaceutical formulations. Two microorganisms, isolated from non-sterile methyl paraben (MP) and propyl paraben (PP) solutions, were found to degrade the respective parabens. Identification by 16S rRNA partial gene sequencing revealed them to be Pseudomonas beteli and Burkholderia latens, respectively. The present work describes a previously unreported interaction of the parabens with P. beteli and B. latens. Degradation of MP at various concentrations by P. beteli, followed a logarithmic pattern, while that of PP by B. latens was found to be linear. It was subsequently observed that P. beteli could degrade only MP, while B. latens could degrade both the parabens. Absence of HPLC chromatogram peaks of expected degradation products indicated that the parabens were used up as a carbon source. The behaviour of pathogens (Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger) of the pharmacopoeial preservative effectiveness test (PET), towards MP, showed that none had the ability to degrade the paraben. It was concluded that, for a paraben-preserved multi-dose ophthalmic formulation, the sole use of the four pathogens that are recommended by the pharmacopoeia for PET can falsely indicate the formulation to be effective against 'in-use' contamination.

  10. Effect of Substituents on the Electronic Structure and Degradation Process in Carbazole Derivatives for Blue OLED Host Materials

    KAUST Repository

    Hong, Minki

    2016-07-25

    We investigate the dissociation mechanism of the C-N bond between carbazole and dibenzothiophene in carbazole-dibenzothiophene (Cz-DBT) positional isomers, selected as representative systems for blue host materials in organic light-emitting diodes (OLEDs). The C-N bond dissociation energies, calculated at the density functional theory level, are found to depend strongly on the charge states of the parental molecules. In particular, the anionic C-N bond dissociations resulting in a carbazole anion can have low dissociation energies (∼1.6 eV) with respect to blue emission energy. These low values are attributed to the large electron affinity of the carbazole radical, a feature that importantly can be modulated via substitution. Substitution also impacts the energies of the first excited electronic states of the Cz-DBT molecules since these states have an intramolecular charge-transfer nature due to the spatially localized character of the frontier molecular orbitals within the carbazole moiety (for the HOMO) and the dibenzothiophene moiety (for the LUMO). The implications of these results must be considered when designing blue OLED hosts since these materials must combine chemical stability and high triplet energy. © 2016 American Chemical Society.

  11. Hydrocarbon-degradation by Isolate Pseudomonas lundensis UTAR FPE2

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    Adeline, S. Y. Ting

    2009-01-01

    Full Text Available In this study, the potential of isolate Pseudomonas lundensis UTAR FPE2 as a hydrocarbon degrader was established. Their biodegradation activity was first detected with the formation of clearing zones on Bushnell-Hass agar plates, with the largest diameter observed on plates supplemented with paraffin, followed by mineral oil and petrol. Utilization of hydrocarbon sources were again detected in broth cultures supplemented with similar hydrocarbon substrates, where the mean viable cell count recovered from hydrocarbon-supplemented broth cultures were higher than the initial inoculum except for napthalene. In both tests, the isolate showed higher degradability towards aliphatic hydrocarbon sources, and the least activity towards the aromatic hydrocarbon naphthalene. The isolate P. lundensis UTAR FPE2 (8 log10 cfu/mL also degraded crude diesel sample, with 69% degradation during the first three days. To conclude, this study suggests the potential use of this isolate for bioremediation of hydrocarbon-contaminated environments.

  12. Aflatoxin B1 Degradation by a Pseudomonas Strain

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    Sangare, Lancine; Zhao, Yueju; Folly, Yawa Minnie Elodie; Chang, Jinghua; Li, Jinhan; Selvaraj, Jonathan Nimal; Xing, Fuguo; Zhou, Lu; Wang, Yan; Liu, Yang

    2014-01-01

    Aflatoxin B1 (AFB1), one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB1, AFB2 and AFM1 by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB) medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB1 effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn2+ and Cu2+ were activators for AFB1 degradation, however, ions Mg2+, Li+, Zn2+, Se2+, Fe3+ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB1 was metabolized to degradation products with chemical properties different from that of AFB1. The results indicated that the degradation of AFB1 by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin. PMID:25341538

  13. Anthranilate degradation by a cold-adapted Pseudomonas sp.

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    Kim, Dockyu; Yoo, Miyoun; Kim, Eungbin; Hong, Soon Gyu

    2015-03-01

    An alpine soil bacterium Pseudomonas sp. strain PAMC 25931 was characterized as eurypsychrophilic (both psychrophilic and mesotolerant) with a broad temperature range of 5-30 °C both for anthranilate (2-aminobenzoate) degradation and concomitant cell growth. Two degradative gene clusters (antABC and catBCA) were detected from a fosmid clone in the PAMC 25931 genomic library; each cluster was confirmed to be specifically induced by anthranilate. When expressed in Escherichia coli, the recombinant AntABC (anthranilate 1,2-dioxygenase, AntDO) converted anthranilate into catechol, exhibiting strict specificity toward anthranilate. Recombinant CatA (catechol 1,2-dioxygenase, C12O) from the organism was active over a broad temperature range (5-37 °C). However, CatA rapidly lost the enzyme activity when incubated at above 25 °C. For example, 1 h-preincubation at 37 °C resulted in 100% loss of enzyme activity, while a counterpart from mesophilic Pseudomonas putida mt-2 did not show any negative effect on the initial enzyme activity. These results suggest that CatA is a new cold-adapted thermolabile enzyme, which might be a product through the adaptation process of PAMC 25931 to naturally cold environments and contribute to its ability to grow on anthranilate there.

  14. Cometabolic degradation kinetics of TCE and phenol by Pseudomonas putida.

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    Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che

    2008-08-01

    Modeling of cometabolic kinetics is important for better understanding of degradation reaction and in situ application of bio-remediation. In this study, a model incorporated cell growth and decay, loss of transformation activity, competitive inhibition between growth substrate and non-growth substrate and self-inhibition of non-growth substrate was proposed to simulate the degradation kinetics of phenol and trichloroethylene (TCE) by Pseudomonas putida. All the intrinsic parameters employed in this study were measured independently, and were then used for predicting the batch experimental data. The model predictions conformed well to the observed data at different phenol and TCE concentrations. At low TCE concentrations (TCE concentrations (>6 mg l(-1)), only the model considering self-inhibition can describe the experimental data, suggesting that a self-inhibition of TCE was present in the system. The proposed model was also employed in predicting the experimental data conducted in a repeated batch reactor, and good agreements were observed between model predictions and experimental data. The results also indicated that the biomass loss in the degradation of TCE below 2 mg l(-1) can be totally recovered in the absence of TCE for the next cycle, and it could be used for the next batch experiment for the degradation of phenol and TCE. However, for higher concentration of TCE (>6 mg l(-1)), the recovery of biomass may not be as good as that at lower TCE concentrations.

  15. Kinetics of p-cresol degradation by an immobilized Pseudomonas sp.

    OpenAIRE

    O'Reilly, K T; Crawford, R L

    1989-01-01

    A p-cresol (PCR)-degrading Pseudomonas sp. was isolated from creosote-contaminated soil and shown to degrade PCR by conversion to protocatechuate via p-hydroxybenzaldehyde (PBA) and p-hydroxybenzoate (PHB). Cells of the Pseudomonas sp. were immobilized in calcium alginate beads and in polyurethane foam. The relationship between the PCR concentration and the PCR transformation rate was investigated in batch and continuous culture bioreactors. The biodegradation kinetics of PBA and PHB also wer...

  16. Degradation of 4-chloro-3-nitrophenol via a novel intermediate, 4-chlororesorcinol by Pseudomonas sp. JHN

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    Arora, Pankaj Kumar; Srivastava, Alok; Singh, Vijay Pal

    2014-03-01

    A 4-chloro-3-nitrophenol (4C3NP)-mineralizing bacterium, Pseudomonas sp. JHN was isolated from a waste water sample collected from a chemically-contaminated area, India by an enrichment method. Pseudomonas sp. JHN utilized 4C3NP as a sole carbon and energy source and degraded it with the release of stoichiometric amounts of chloride and nitrite ions. Gas chromatography and gas chromatography-mass spectrometry detected 4-chlororesorcinol as a major metabolite of the 4C3NP degradation pathway. Inhibition studies using 2,2'-dipyridyl showed that 4-chlororesorcinol is a terminal aromatic compound in the degradation pathway of 4C3NP. The activity for 4C3NP-monooxygenase was detected in the crude extracts of the 4C3NP-induced JHN cells that confirmed the formation of 4-chlororesorcinol from 4C3NP. The capillary assay showed that Pseudomonas sp. JHN exhibited chemotaxis toward 4C3NP. The bioremediation capability of Pseudomonas sp. JHN was monitored to carry out the microcosm experiments using sterile and non-sterile soils spiked with 4C3NP. Strain JHN degraded 4C3NP in sterile and non-sterile soil with same degradation rates. This is the first report of (i) bacterial degradation and bioremediation of 4C3NP, (ii) formation of 4-chlororesorcinol in the degradation pathway of 4C3NP, (iii) bacterial chemotaxis toward 4C3NP.

  17. Trichloroethylene degradation by Escherichia coli containing the cloned Pseudomonas putida F1 toluene dioxygenase genes.

    OpenAIRE

    Zylstra, G J; Wackett, L P; Gibson, D T

    1989-01-01

    Toluene dioxygenase from Pseudomonas putida F1 has been implicated as an enzyme capable of degrading trichloroethylene. This has now been confirmed with Escherichia coli JM109(pDTG601) that contains the structural genes (todC1C2BA) of toluene dioxygenase under the control of the tac promoter. The extent of trichloroethylene degradation by the recombinant organism depended on the cell concentration and the concentration of trichloroethylene. A linear rate of trichloroethylene degradation was o...

  18. Degradation of 1,3-dichloropropene by Pseudomonas cichorii 170

    NARCIS (Netherlands)

    Poelarends, G.J.; Wilkens, M.; Larkin, M.J.; Elsas, van J.D.; Janssen, D.B.

    1998-01-01

    The gram-negative bacterium Pseudomonas cichorii 170, isolated from soil that was repeatedly treated with the nematocide 1,3-dichloropropene, could utilize low concentrations of 1,3-dichloropropene as a sole carbon and energy source. Strain 170 was also able to grow on 3-chloroallyl alcohol, 3- chlo

  19. Degradation of 1,3-dichloropropene by Pseudomonas cichorii 170

    NARCIS (Netherlands)

    Poelarends, Gerrit J.; Wilkens, Marga; Larkin, Michael J.; Elsas, Jan Dirk van; Janssen, Dick B.

    1998-01-01

    The gram-negative bacterium Pseudomonas cichorii 170, isolated from soil that was repeatedly treated with the nematocide 1,3-dichloropropene, could utilize low concentrations of 1,3-dichloropropene as a sole carbon and energy source, Strain 170 was also able to grow on 3-chloroallyl alcohol, 3-chlor

  20. ARSENIC DEGRADATION BY Pseudomonas aeruginosa FOR WATER BIOREMEDIATION. PRELIMINARY STUDY

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    Esther E. Pellizzari

    2015-03-01

    Full Text Available The aim of this study was to investigate the arsenic resistance in pure cultivations of Pseudomonas aeruginosa isolated from Presidencia Roque Sáenz Peña groundwater (Chaco province, and evaluate the possibility of its use to remove arsenic from groundwater. Strains were immobilized in natural stone and cultivated in salts broth and 1 mgAs/L. The arsenic resistance and biofilm formation were observed, obtaining interaction between cells, rock and arsenic. Arsenic removal was evaluated during 3 months and its final percentage of the experiment was 60%.

  1. Differential degradation of crude oil (Bonny Light) by four Pseudomonas strains

    Institute of Scientific and Technical Information of China (English)

    Oluwafemi S. Obayori; Sunday A. Adebusoye; Adams O. Adewale; Ganiyu O. Oyetibo; Odunola O. Oluyemi; Rashid A. Amokun; Matthew O. Ilori

    2009-01-01

    Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials.All the isolates were identified as species of Pseudomonas.Pseudomonas putida P11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P.aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene.Pseudomonas putida WL2 and P.aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11.All the strains grew logarithmically with 1-2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence.Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period.BB3 on the other hand degraded only 46% within 6 d.Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks (including aliphatics and aromatics) in the hydrocarbon mixture.

  2. Kinetics of p-cresol degradation by an immobilized Pseudomonas sp.

    Science.gov (United States)

    O'Reilly, K T; Crawford, R L

    1989-04-01

    A p-cresol (PCR)-degrading Pseudomonas sp. was isolated from creosote-contaminated soil and shown to degrade PCR by conversion to protocatechuate via p-hydroxybenzaldehyde (PBA) and p-hydroxybenzoate (PHB). Cells of the Pseudomonas sp. were immobilized in calcium alginate beads and in polyurethane foam. The relationship between the PCR concentration and the PCR transformation rate was investigated in batch and continuous culture bioreactors. The biodegradation kinetics of PBA and PHB also were investigated. In batch culture reactors, the maximum PCR degradation rate (Vmax) for the alginate-immobilized Pseudomonas sp. cells was 1.5 mg of PCR g of bead-1 h-1 while the saturation constant (Ks) was 0.22 mM. For PHB degradation, the Vmax was 0.62 mg of PHB g of bead-1 h-1 while the Ks was 0.31 mM. For polyurethane-immobilized Pseudomonas sp. cells, the Vmax of PCR degradation was 0.80 mg of PCR g of foam-1 h-1 while the Ks was 0.28 mM. For PHB degradation, the Vmax was 0.21 mg of PHB g of foam-1 h-1 and the Ks was 0.22 mM. In a continuous column alginate bead reactor, the Vmax for PCR transformation was 2.6 mg g of bead-1 h-1 while the Ks was 0.20 mM. The Vmax and Ks for PBA transformation in the presence of PCR were 0.93 mg g of bead-1 h-1 and 0.063 mM, respectively. When PHB alone was added to a reactor, the Vmax was 1.48 mg g of bead-1 h-1 and the Ks was 0.32 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. DETECTION OF PHENOL DEGRADING BACTERIA AND PSEUDOMONAS PUTIDA IN ACTIVATED SLUDGE BY POLYMERASE CHAIN REACTION

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    H. Movahedyan ، H. Khorsandi ، R. Salehi ، M. Nikaeen

    2009-04-01

    Full Text Available Phenol is one of the organic pollutants in various industrial wastewaters especially petrochemical and oil refining. Biological treatment is one of the considerable choices for removing of phenol present in these wastewaters. Identification of effective microbial species is considered as one of the important priorities for production of the biomass in order to achieve desirable kinetic of biological reactions. Basic purpose of this research is identification of phenol-degrading Pseudomonas Putida in activated sludge by polymerase chain reaction (PCR that has high speed and specificity. In this research, 10 various colonies of phenol-degrading bacteria were isolated from municipal activated sludge and the rate of phenol removal and growth rate of these bacteria were assessed in different concentrations of phenol (200 – 900 mg/L. Confirmation of the largest subunit of multicomponent phenol hydroxylase (LmPH gene and gene coding the N fragment in Pseudomonas Putida-derived methyl phenol operon (DmpN gene through PCR were used for general identification of phenol-degrading bacteria and Pseudomonas Putida, respectively. Presence of a 600 bp (base pairs bond in all of isolated strains indicated that they contain phenol hydroxylase gene. 6 of 10 isolated bacteria were Pseudomonas Putida because they produced a 199 bp PCR product by DmpN primers. According to PCR results in this study, the best phenol-degrading bacteria that can utilize 500 – 600 mg/L phenol completely after 48 hours incubation, belong to Pseudomonas Putida strains. It is clear that use of isolated bacteria can lead to considerable decrease of treatment time as well as promotion of phenol removal rate.

  4. Degradation kinetics and pathway of phenol by Pseudomonas and Bacillus species.

    Science.gov (United States)

    Hasan, Syed Adnan; Jabeen, Suraiya

    2015-01-02

    This article elucidates that strain Pseudomonas aeruginosa (IES-Ps-1) is a versatile toxic organic compound degrader. With the degradation of malathion and cypermethrin (studied by other researchers previously), this strain was able to degrade phenol. Two other indigenous soil flora (i.e., Pseudomonas sp. (IES-S) and Bacillus subtilis (IES-B)) were also found to be potential phenol degraders. Phenol was degraded with Monod kinetics during growth in nutrient broth and mineral salts medium. Before entering into the growth inhibition phase, strains IES-Ps-1, IES-S and IES-B could tolerate up to 400, 700 and 500 mg/L phenol, respectively, when contained in nutrient broth. However, according to the Luong-Levenspiel model, the growth of strains IES-Ps-1, IES-S and IES-B would cease at 2000, 2174 and 2190 mg/L phenol, respectively. Strain IES-Ps-1 degraded 700, 900 and 1050 mg/L phenol contained in mineral salts medium with the specific rates of 0.034, 0.075 and 0.021 h(-1), respectively. All these strains grew by making clusters when exposed to phenol in order to prevent damages due to high substrate concentration. These strains transformed phenol into catechol, which was then degraded via ortho-cleavage pathway.

  5. Assessment of acrylamide degradation potential of Pseudomonas aeruginosa BAC-6 isolated from industrial effluent.

    Science.gov (United States)

    Chandrashekar, Vijayashree; Chandrashekar, Chandrika; Shivakumar, Rajath; Bhattacharya, Sourav; Das, Arijit; Gouda, Bhaskar; Rajan, Subbaramiah Sundara

    2014-07-01

    Acrylamide finds diverse industrial applications but is considered an environmental threat because of its neurotoxic, carcinogenic, and teratogenic effects. Certain bacteria enzymatically degrade acrylamide to acrylic acid and ammonia. The present investigation was carried out to isolate and identify an acrylamide-degrading bacterium from industrial effluent. Bacterial growth and extent of acrylamide degradation in the presence of different acrylamide concentrations, nutrients, varied range of pH, and temperature were analyzed. Among the eight acrylamide-degrading isolates, isolate BAC-6 demonstrated the highest degradation, and based upon the partial 16S rDNA sequencing, it was identified as Pseudomonas aeruginosa. P. aeruginosa BAC-6 grew over a wide range of acrylamide concentrations, but the highest degradation was recorded at 500 mg/L concentration with concomitant cell growth. Among the carbon supplements, mannitol supported the highest growth and degradation. Maximum degradation was reported at neutral pH. A mesophilic temperature range (25-40 °C) facilitated conducive bacterial growth followed by degradation. The highest degradation and bacterial growth were observed at 30 and 35 °C, respectively. Thus, it could be inferred from the present investigation that cultural conditions strongly affected the degradation potential of P. aeruginosa BAC-6 and advocated the utilization of the isolate in bioremediation of sites polluted with acrylamide.

  6. Physiological and biochemical characterization of a novel nicotine-degrading bacterium Pseudomonas geniculata N1.

    Directory of Open Access Journals (Sweden)

    Yanghui Liu

    Full Text Available Management of solid wastes with high nicotine content, such as those accumulated during tobacco manufacturing, poses a major challenge, which can be addressed by using bacteria such as Pseudomonas and Arthrobacter. In this study, a new species of Pseudomonas geniculata, namely strain N1, which is capable of efficiently degrading nicotine, was isolated and identified. The optimal growth conditions for strain N1 are a temperature of 30°C, and a pH 6.5, at a rotation rate of 120 rpm min(-1 with 1 g l(-1 nicotine as the sole source of carbon and nitrogen. Myosmine, cotinine, 6-hydroxynicotine, 6-hydroxy-N-methylmyosmine, and 6-hydroxy-pseudooxynicotine were detected as the five intermediates through gas chromatography-mass and liquid chromatography-mass analyses. The identified metabolites were different from those generated by Pseudomonas putida strains. The analysis also highlighted the bacterial metabolic diversity in relation to nicotine degradation by different Pseudomonas strains.

  7. [Extraction, Purification and Identification of a Dexamethasone-degrading Enzymes Generated by Pseudomonas Alcaligenes].

    Science.gov (United States)

    Zhu, Lili; Yang, Zhibang; Yang, Qian; Shi, Zhongquan; Deng, Xichuan

    2015-10-01

    In this research a strain of isolated Pseudomonas alcaligenes which causes degradation of dexamethasone was acclimated further and its proteins of every position in the bacterium were separated by the osmotic shock method. The separated intracellular proteins which had the highest enzyme activity were extracted by the salting out with ammonium sulfate and were purified with the cation exchange chromatography and gel chromatography. The purified proteins which was active to cause degradation of dexamethasone had been detected were cut with enzyme and were analyzed with mass spectrometry. The results showed that the degradation rate to dexamethasone by acclimated Pseudomonas alcaligenes were increased from 23.63% to 52.84%. The degrading enzymes were located mainly in the intracellular of the bacteria and its molecular weight was about 41 kD. The specific activity of the purified degrading enzymes were achieved to 1.02 U x mg(-1). Its 5-peptide amino acid sequences were consistent with some sequences of the isovaleryl-CoA dehydrogenase. The protein enzyme may be a new kind degrading enzyme of steroidal compounds. Our experimental results provided new strategies for cleanup of dexamethasone in water environment with microbial bioremediation technique.

  8. Degradation of Reactive Black 5 dye by a newly isolated bacterium Pseudomonas entomophila BS1.

    Science.gov (United States)

    Khan, Sana; Malik, Abdul

    2016-03-01

    The textile and dye industries are considered as one of the major sources of environmental pollution. The present study was conducted to investigate the degradation of the azo dye Reactive Black 5 (RB 5) using a bacterium isolated from soil samples collected around a textile industry. The bacterial strain BS1 capable of degrading RB 5 was isolated and identified as Pseudomonas entomophila on the basis of 16S rDNA sequencing. The effects of different parameters on the degradation of RB 5 were studied to find out the optimal conditions required for maximum degradation, which was 93% after 120 h of incubation. Static conditions with pH in the range of 5-9 and a temperature of 37 °C were found to be optimum for degrading RB 5. Enzyme assays demonstrated that P. entomophila possessed azoreductase, which played an important role in degradation. The enzyme was dependent on flavin mononucleotide and NADH for its activity. Furthermore, a possible degradation pathway of the dye was proposed through gas chromatography - mass spectrometry analysis, which revealed that the metabolic products were naphthalene-1,2-diamine and 4-(methylsulfonyl) aniline. Thus the ability of this indigenous bacterial isolate for simultaneous decolorization and degradation of the azo dye signifies its potential application for treatment of industrial wastewaters containing azo dyes.

  9. The Regulation of para-Nitrophenol Degradation in Pseudomonas putida DLL-E4

    Science.gov (United States)

    Chen, Qiongzhen; Tu, Hui; Luo, Xue; Zhang, Biying; Huang, Fei; Li, Zhoukun; Wang, Jue; Shen, Wenjing; Wu, Jiale; Cui, Zhongli

    2016-01-01

    Pseudomonas putida DLL-E4 can efficiently degrade para-nitrophenol and its intermediate metabolite hydroquinone. The regulation of para-nitrophenol degradation was studied, and PNP induced a global change in the transcriptome of P. putida DLL-E4. When grown on PNP, the wild-type strain exhibited significant downregulation of 2912 genes and upregulation of 845 genes, whereas 2927 genes were downregulated and 891 genes upregulated in a pnpR-deleted strain. Genes related to two non-coding RNAs (ins1 and ins2), para-nitrophenol metabolism, the tricarboxylic acid cycle, the outer membrane porin OprB, glucose dehydrogenase Gcd, and carbon catabolite repression were significantly upregulated when cells were grown on para-nitrophenol plus glucose. pnpA, pnpR, pnpC1C2DECX1X2, and pnpR1 are key genes in para-nitrophenol degradation, whereas pnpAb and pnpC1bC2bDbEbCbX1bX2b have lost the ability to degrade para-nitrophenol. Multiple components including transcriptional regulators and other unknown factors regulate para-nitrophenol degradation, and the transcriptional regulation of para-nitrophenol degradation is complex. Glucose utilization was enhanced at early stages of para-nitrophenol supplementation. However, it was inhibited after the total consumption of para-nitrophenol. The addition of glucose led to a significant enhancement in para-nitrophenol degradation and up-regulation in the expression of genes involved in para-nitrophenol degradation and carbon catabolite repression (CCR). It seemed that para-nitrophenol degradation can be regulated by CCR, and relief of CCR might contribute to enhanced para-nitrophenol degradation. In brief, the regulation of para-nitrophenol degradation seems to be controlled by multiple factors and requires further study. PMID:27191401

  10. The Regulation of para-Nitrophenol Degradation in Pseudomonas putida DLL-E4.

    Directory of Open Access Journals (Sweden)

    Qiongzhen Chen

    Full Text Available Pseudomonas putida DLL-E4 can efficiently degrade para-nitrophenol and its intermediate metabolite hydroquinone. The regulation of para-nitrophenol degradation was studied, and PNP induced a global change in the transcriptome of P. putida DLL-E4. When grown on PNP, the wild-type strain exhibited significant downregulation of 2912 genes and upregulation of 845 genes, whereas 2927 genes were downregulated and 891 genes upregulated in a pnpR-deleted strain. Genes related to two non-coding RNAs (ins1 and ins2, para-nitrophenol metabolism, the tricarboxylic acid cycle, the outer membrane porin OprB, glucose dehydrogenase Gcd, and carbon catabolite repression were significantly upregulated when cells were grown on para-nitrophenol plus glucose. pnpA, pnpR, pnpC1C2DECX1X2, and pnpR1 are key genes in para-nitrophenol degradation, whereas pnpAb and pnpC1bC2bDbEbCbX1bX2b have lost the ability to degrade para-nitrophenol. Multiple components including transcriptional regulators and other unknown factors regulate para-nitrophenol degradation, and the transcriptional regulation of para-nitrophenol degradation is complex. Glucose utilization was enhanced at early stages of para-nitrophenol supplementation. However, it was inhibited after the total consumption of para-nitrophenol. The addition of glucose led to a significant enhancement in para-nitrophenol degradation and up-regulation in the expression of genes involved in para-nitrophenol degradation and carbon catabolite repression (CCR. It seemed that para-nitrophenol degradation can be regulated by CCR, and relief of CCR might contribute to enhanced para-nitrophenol degradation. In brief, the regulation of para-nitrophenol degradation seems to be controlled by multiple factors and requires further study.

  11. Thiamethoxam degradation by Pseudomonas and Bacillus strains isolated from agricultural soils.

    Science.gov (United States)

    Rana, Shivnam; Jindal, Vikas; Mandal, Kousik; Kaur, Gurpreet; Gupta, V K

    2015-05-01

    Twelve bacterial species were evaluated to know the degradation pattern of thiamethoxam in liquid medium. All the bacterial species could actively degrade phorate in a mineral salt medium containing phorate (50 μg ml(-1)) as sole carbon source. As these species have ability to degrade, we used these for the degradation of thiamethoxam--a neonicoitinoids. Screening of 12 active phorate-metabolizing bacterial species resulted in selection of Bacillus aeromonas strain IMBL 4.1 and Pseudomonas putida strain IMBL 5.2 causing 45.28 and 38.23 % thiamethoxam (50 μg ml(-1)) reduction, respectively, in 15 days as potential thiamethoxam degrading species. These two bacterial species grew optimally at 37 °C under shake culture conditions in MSMT medium raised with initial pH of 6.0-6.5 and use of these optimum cultural conditions resulted in improved thiamethoxam degradation by these bacterial species. These species caused maximum thiamethoxam degradation only in the presence of thiamethoxam as sole source of carbon and energy and the same was reduced in the presence of easily metabolize able carbon (C₀ and C₁) and nitrogen ((N₀, N₁ and N₂) sources. This could be attributed to involvement of repressible metabolic pathways, reactions of which are inhibited by the presence of easily available nutrients for growth. Besides above, qualitative analysis of thiamethoxam residues by gas liquid chromatography revealed complete metabolization of thiamethoxam without detectable accumulation of any known thiamethoxam metabolites.

  12. The potential of free cells of Pseudomonas aeruginosa on textile dye degradation.

    Science.gov (United States)

    Selvakumar, Kuppusamy Vaithilingam; Basha, Chiya Ahmed; Prabhu, Harinarayan Janardhana; Kalaichelvi, Ponnusamy; Nelliyan, Sudha

    2010-04-01

    The objective of the present work was to reduce chemical oxygen demand (COD), color of textile effluent containing dye Procion Blue 2G and recycle the treated effluent. To achieve this objective, the degradation potential of bacterial strain Pseudomonas aeruginosa was tested. In degradation, the 'clean' electro-oxidation (EO) process was combined with bio-treatment such that an electro-oxidation step was included between two bio-degradation treatments. Bio-oxidation process was carried out under aerobic and anoxic conditions. Results showed more than 90% reduction in COD and complete removal of color at the end of two cycles of combined oxidation process with a post electro-oxidation. The treated effluent was then subjected to photo-oxidation to remove the microbes so that the water can be recycled after the removal of total dissolved solids (TDS).

  13. Cometabolic Degradation of Trichloroethylene by Pseudomonas cepacia G4 in a Chemostat with Toluene as the Primary Substrate

    NARCIS (Netherlands)

    Landa, Andrew S.; Sipkema, E. Marijn; Weijma, Jan; Beenackers, Antonie A.C.M.; Dolfing, Jan; Janssen, Dick B.

    1994-01-01

    Pseudomonas cepacia G4 is capable of cometabolic degradation of trichloroethylene (TCE) if the organism is grown on certain aromatic compounds. To obtain more insight into the kinetics of TCE degradation and the effect of TCE transformation products, we have investigated the simultaneous conversion

  14. Enhanced degradation of eletrooxidized textile effluent by petroleum degrading Pseudomonas aeruginosa (MTCC No.1201) at compressed gas pressure.

    Science.gov (United States)

    Santhanam, Manikandan; Annamalai, Sivasankar; Umarkatha, Sayera Banu; Sundaram, Maruthamuthu

    2015-03-01

    The textile dyeing industry produces large volumes of wastewater during dyeing processes where the major step includes the color removal and COD removal. In the present study, the combined electrooxidation process and a novel biological degradation at high compressed gas pressure were studied. The removal of color in the real textile dye effluent was achieved by electrooxidation with Titanium Substrate Insoluble anode and titanium as cathode through generation of hypochlorite. The hypochlorite produced during the electrooxidation was removed by exposing the solution to direct sunlight. The impact of compressed atmospheric condition on the degradation of organics by Pseudomonas aeruginosa (MTCC No.1201, GenBank Acc. No KC545414) was studied. The compressed gas pressure condition increases the level of dissolved gas in the liquid phase and exerts the pressure on the growing cells in the liquid phase. Interesting synchronization between the utilization of oxygen by active microbial cells and the dissolution of oxygen in the water from gas phase was observed which enhanced the bacterial degradation process. It should be mentioned here that the P. aeruginosa was grown without addition of nutrients. The compressed atmospheric pressure enhances the bacterial proliferation, EPS production and COD reduction in the electrooxidized effluent. FTIR and HPLC reveal the degradation of organics in the compressed pressure condition.

  15. Isolation of a Pseudomonas Stutzeri strain that degrades1, 2, 4-trichlorobenzene and characterization of its degradative plasmid

    Institute of Scientific and Technical Information of China (English)

    Lei SONG; Hui WANG; Hanchang SHI; Hongying HU

    2008-01-01

    The genetic information encoding metabolic pathways for xenobiotic compounds in bacteria often resides on catabolic plasmids. The aim of the present work was to know the location of the genes for degrading 1, 2, 4-trichlorobenzen. In this paper a 1, 2, 4-trichlorobenzene-degrading strain THSL-1 was isolated from the soil of Tianjin Chemical Plant using 1, 2, 4-trichlorobenzene as the sole carbon source. The strain was identified as Pseudomonas stutzeri through morphologic survey and 16S rDNA sequence determination. A plasmid was discovered from strain THSL-1 by using the alkali lysis method. When the plasmid was transformed into E. coli. JM109 by the CaCl2 method, the transformant could grow using 1, 2, 4-trichlorobenzene as the sole carbon source and had the degradation function of 1, 2, 4-trichlorobenzene. Therefore, it could be deemed that the plasmid carried the degradative genes of 1, 2, 4-trichlorobenzene. The average size of the plasmid was finally determined to be 40.2 Kb using selectively three kinds of restricted inscribed enzymes (HindIII, BamHI, and XholI) for single cutting and double cutting the plasmid pTHSL-1, respectively.

  16. The T7-related Pseudomonas putida phage φ15 displays virion-associated biofilm degradation properties.

    Directory of Open Access Journals (Sweden)

    Anneleen Cornelissen

    Full Text Available Formation of a protected biofilm environment is recognized as one of the major causes of the increasing antibiotic resistance development and emphasizes the need to develop alternative antibacterial strategies, like phage therapy. This study investigates the in vitro degradation of single-species Pseudomonas putida biofilms, PpG1 and RD5PR2, by the novel phage ϕ15, a 'T7-like virus' with a virion-associated exopolysaccharide (EPS depolymerase. Phage ϕ15 forms plaques surrounded by growing opaque halo zones, indicative for EPS degradation, on seven out of 53 P. putida strains. The absence of haloes on infection resistant strains suggests that the EPS probably act as a primary bacterial receptor for phage infection. Independent of bacterial strain or biofilm age, a time and dose dependent response of ϕ15-mediated biofilm degradation was observed with generally a maximum biofilm degradation 8 h after addition of the higher phage doses (10(4 and 10(6 pfu and resistance development after 24 h. Biofilm age, an in vivo very variable parameter, reduced markedly phage-mediated degradation of PpG1 biofilms, while degradation of RD5PR2 biofilms and ϕ15 amplification were unaffected. Killing of the planktonic culture occurred in parallel with but was always more pronounced than biofilm degradation, accentuating the need for evaluating phages for therapeutic purposes in biofilm conditions. EPS degrading activity of recombinantly expressed viral tail spike was confirmed by capsule staining. These data suggests that the addition of high initial titers of specifically selected phages with a proper EPS depolymerase are crucial criteria in the development of phage therapy.

  17. Protease Activities of Semi-purified Pseudomonas fluorescensin Protein Degradation of Pasteurized Milk at Storage

    Directory of Open Access Journals (Sweden)

    Tatik Khusniati

    2012-10-01

    Full Text Available Protein on stored milks spoiled due to protease activities of Pseudomonas fluorescens. To know protease effect on milks, protease activities of semi-purified P. fluorescens on protein degradation in stored pasteurized milks were detected. Protease was semi-purified by ethanol 70%. Protease activities were detected by modified Lowry method, protein degradation by formol titration, and protein content by Kjeldahl method. Milk storage' times were conducted on 0 day (4 days before expired date up to 12 days (8 days after expired date. The results show that the longer the storage times the higher protease activities and protein degradation of milks. At storage 12 days, protease activities on control were 0.2556 Unit/mL (skim and 0.2116 Unit/mL (whole, and on inoculated milk (crude was 2.2044 Unit/mL (skim and 1.5378 Unit/mL (whole; while on inoculated milk (semi-purified was 3.5355 Unit/mL (skim and 1.6778 Unit/mL (whole, respectively. The decrease of inoculated milk' homogeneous were faster than that of control. Protein degradation on control, inoculated skim milks (crude and semi-purified on 12 days were 4.48%, 7.28% and 7.62%, while that on whole milks were 3.81%, 7.28% and 6.04%, respectively. Based on protease, protein degradation and homogeneous, it can be concluded that skim milk spoiled faster than whole milk.

  18. Stimulation of diesel degradation and biosurfactant production by aminoglycosides in a novel oil-degrading bacterium Pseudomonas luteola PRO23

    Directory of Open Access Journals (Sweden)

    Atanasković Iva M.

    2016-01-01

    Full Text Available Bioremediation is promising technology for dealing with oil hydrocarbons contamination. In this research growth kinetics and oil biodegradation efficiency of Pseudomonas luteola PRO23, isolated from crude oil-contaminated soil samples, were investigated under different concentrations (5, 10 and 20 g/L of light and heavy crude oil. More efficient biodegradation and more rapid adaptation and cell growth were obtained in conditions with light oil. The 5 to 10 g/L upgrade of light oil concentration stimulated the microbial growth and the biodegradation efficiency. Further upgrade of light oil concentration and the upgrade of heavy oil concentration both inhibited the microbial growth, as well as biodegradation process. Aminoglycosides stimulated biosurfactant production in P. luteola in the range of sub-inhibitory concentrations (0.3125, 0.625 μg/mL. Aminoglycosides also induced biofilm formation. The production of biosurfactants was the most intense during lag phase and continues until stationary phase. Aminoglycosides also induced changes in P. luteola growth kinetics. In the presence of aminoglycosides this strain degraded 82% of diesel for 96 h. These results indicated that Pseudomonas luteola PRO23 potentially can be used in bioremediation of crude oil-contaminated environments and that aminoglycosides could stimulate this process. [Projekat Ministarstva nauke Republike Srbije, br. TR31080

  19. Analysis of cumene (isopropylbenzene) degradation genes from Pseudomonas fluorescens IP01.

    Science.gov (United States)

    Habe, H; Kasuga, K; Nojiri, H; Yamane, H; Omori, T

    1996-12-01

    We obtained the DNA fragments encoding 2-hydroxy-6-oxo-7-methylocta-2,4-dienoic acid (HOMODA) hydrolase in the cumene (isopropylbenzene) degrader Pseudomonas fluorescens strain IP01 via PCR using two synthesized oligonucleotides corresponding to the conserved regions within known meta-cleavage compound hydrolases. Following colony hybridization using the amplified DNA as a probe, a 4.5-kb HindIII fragment was isolated from P. fluorescens IP01. After determining the nucleotide sequence of this fragment, three open reading frames (ORF11 [cumH], ORF12 [cumD], and ORF13) were identified. The deduced amino acid sequence of ORF12 showed homology with meta-cleavage compound hydrolases encoded by the tod, dmp, xyl, and bph operons. Although the product of ORF12 was found to exhibit HOMODA and 2-hydroxy-6-oxohepta-2,4-dienoic acid (HOHDA) hydrolase activities, it did not exhibit 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) hydrolase activity. The deduced amino acid sequence of ORF11 showed 40.4% homology with the sequence of todX in Pseudomonas putida F1 (Y. Wang, M. Ralings, D. T. Gibson, D. Labbé, H. Bergeron, R. Brousseau, and P. C. K. Lau, Mol. Gen. Genet. 246:570-579, 1995). The nucleotide sequence of ORF13 and its flanking region showed strong homology (91.0%) with IS52 from Pseudomonas savastanoi (Y. Yamada, P.-D. Lee, and T. Kosuge, Proc. Natl. Acad. Sci. USA 83:8263-8267, 1982). By characterization of cumH and cumD, the entire cum gene cluster from the cumene-degrader P. fluorescens IP01 (cumA1A2A3A4BCEGFHD) has been identified.

  20. Optimization for Microbial Degradation of Dibenzothiophene by Pseudomonas sp. LKY-5 Using Response Surface Methodology

    Institute of Scientific and Technical Information of China (English)

    Li Lin; Zhao Chaocheng; Liu Qiyou; Zhang Yunbo; Liu Chunshuang; Xue Jianliang

    2014-01-01

    In this research, the degradation of dibenzothiophene (DBT) was investigated by using Pseudomonas sp. LKY-5 isolated from oil contaminated soil. The response surface methodology (RSM) based on the Box-Behnken design (BBD) was applied for evaluating the interactive effects of four independent variables including substrate concentration, tempera-ture, pH and agitation rate on the DBT removal response. A total of 29 experiments for four factors at three levels were conducted in present study. A second-order regression model was then developed, and the analysis of variance (ANOVA) illustrated that the proposed quadratic model could be utilized to navigate the design space. The value of determination coefif-cient (R2=0.953 4) indicated a satisfactory agreement between the quadratic model and the experimental data. It was found that DBT removal was more signiifcantly affected (P<0.000 1) by substrate concentration compared with other three parameters. An 100%degradation of DBT could be obtained by Pseudomonas sp. LKY-5 at a substrate concentration of 100 mg/L.

  1. Degradation of phenol and TCE using suspended and chitosan-bead immobilized Pseudomonas putida.

    Science.gov (United States)

    Chen, Yan-Min; Lin, Tsair-Fuh; Huang, Chih; Lin, Jui-Che; Hsieh, Feng-Ming

    2007-09-30

    The degradability of phenol and trichloroethene (TCE) by Pseudomonas putida BCRC 14349 in both suspended culture and immobilized culture systems are investigated. Chitosan beads at a size of about 1-2mm were employed to encapsulate the P. putida cells, becoming an immobilized culture system. The phenol concentration was controlled at 100 mg/L, and that of TCE was studied from 0.2 to 20 mg/L. The pH, between 6.7 and 10, did not affect the degradation of either phenol or TCE in the suspended culture system. However, it was found to be an important factor in the immobilized culture system in which the only significant degradation was observed at pH >8. This may be linked to the surface properties of the chitosan beads and its influence on the activity of the bacteria. The transfer yield of TCE on a phenol basis was almost the same for the suspended and immobilized cultures (0.032 mg TCE/mg phenol), except that these yields occurred at different TCE concentrations. The transfer yield at a higher TCE concentration for the immobilized system suggested that the cells immobilized in carriers can be protected from harsh environmental conditions. For kinetic rate interpretation, the Monod equation was employed to describe the degradation rates of phenol, while the Haldane's equation was used for TCE degradation. Based on the kinetic parameters obtained from the two equations, the rate for the immobilized culture systems was only about 1/6 to that of the suspended culture system for phenol degradation, and was about 1/2 for TCE degradation. The slower kinetics observed for the immobilized culture systems was probably due to the slow diffusion of substrate molecules into the beads. However, compared with the suspended cultures, the immobilized cultures may tolerate a higher TCE concentration as much less inhibition was observed and the transfer yield occurred at a higher TCE concentration.

  2. Metabolic Degradation of 1,4-dichloronaphthalene by Pseudomonas sp. HY

    Directory of Open Access Journals (Sweden)

    Jian Yu

    2015-08-01

    Full Text Available There is increasing concern regarding the adverse health effects of polychlorinated naphthalenes (PCNs. The metabolic degradation of 1,4-dichloronaphthalene (1,4-DCN as a model PCN, was studied using a strain of Pseudomonas sp. HY. The metabolites were analyzed by gas chromatography-mass spectrometry (GC-MS. A series of metabolites including dihydroxy-dichloro-naphthalene, epoxy-dichlorinated naphthalene, dichlorinated naphthol, and dichlorinated salicylic acid were identified. The time-concentration plots of the degradation curves of 1,4-DCN was also obtained from the experiments, which set the initial concentration of 1,4-DCN to 10 mg/L and 20 mg/L, respectively. The results showed that 98% removal could be achieved within 48 h at an initial 1,4-DCN concentration of 10 mg/L. Nevertheless, it took 144 h to reach the same degradation efficiency at an initial concentration of 20 mg/L. The degradation of 1,4-DCN may not remove the chloride ions during the processes and the metabolites may not benefit the bacterial growth. The research suggests a metabolic pathway of 1,4-DCN, which is critical for the treatment of this compound through biological processes.

  3. Strategy of Pseudomonas pseudoalcaligenes C70 for effective degradation of phenol and salicylate

    Science.gov (United States)

    Heinaru, Eeva; Naanuri, Eve; Mehike, Maris; Leito, Ivo; Heinaru, Ain

    2017-01-01

    Phenol- and naphthalene-degrading indigenous Pseudomonas pseudoalcaligenes strain C70 has great potential for the bioremediation of polluted areas. It harbours two chromosomally located catechol meta pathways, one of which is structurally and phylogenetically very similar to the Pseudomonas sp. CF600 dmp operon and the other to the P. stutzeri AN10 nah lower operon. The key enzymes of the catechol meta pathway, catechol 2,3-dioxygenase (C23O) from strain C70, PheB and NahH, have an amino acid identity of 85%. The metabolic and regulatory phenotypes of the wild-type and the mutant strain C70ΔpheB lacking pheB were evaluated. qRT-PCR data showed that in C70, the expression of pheB- and nahH-encoded C23O was induced by phenol and salicylate, respectively. We demonstrate that strain C70 is more effective in the degradation of phenol and salicylate, especially at higher substrate concentrations, when these compounds are present as a mixture; i.e., when both pathways are expressed. Moreover, NahH is able to substitute for the deleted PheB in phenol degradation when salicylate is also present in the growth medium. The appearance of a yellow intermediate 2-hydroxymuconic semialdehyde was followed by the accumulation of catechol in salicylate-containing growth medium, and lower expression levels and specific activities of the C23O of the sal operon were detected. However, the excretion of the toxic intermediate catechol to the growth medium was avoided when the growth medium was supplemented with phenol, seemingly due to the contribution of the second meta pathway encoded by the phe genes. PMID:28257519

  4. Effects of quorum sensing autoinducer degradation gene on virulence and biofilm formation of Pseudomonas aeruginosa

    Institute of Scientific and Technical Information of China (English)

    WANG Yao; DAI Yue; ZHANG Yong; HU YangBo; YANG BaoYu; CHEN ShiYun

    2007-01-01

    The aiiA gene from Bacillus thuringiensis was cloned into the Pseudomonas/E. coli shuttle vector and transformed into Pseudomonas aeruginosa strain PAO1. Western blotting showed that the AiiA protein was expressed in PAO1. After induction by IPTG for 6 h and 18 h, expression of the aiiA gene in PAO1completely degraded the quorum sensing autoinducers N-acylhomoserine lactones (AHLs):N-oxododecanoyI-L-homoserine lactone (OdDHL) and N-butyryI-L-homoserine lactone (BHL). The reduced amount of AHLs in PAO1 was also correlated with decreased expression and production of several virulence factors such as elastase and pyocyanin. AiiA expression also influenced bacterial swarming motility. Most importantly, our studies indicated that aiiA played significant roles in P.aeruginosa biofilm formation and dispersion, as observed by the differences of the biofilm formation on liquid and solid surfaces, and biofilm structures under a scanning electron microscope.

  5. Effects of quorum sensing autoinducer degradation gene on virulence and biofilm formation of Pseudomonas aeruginosa

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The aiiA gene from Bacillus thuringiensis was cloned into the Pseudomonas/E. coli shuttle vector and transformed into Pseudomonas aeruginosa strain PAO1. Western blotting showed that the AiiA protein was expressed in PAO1. After induction by IPTG for 6 h and 18 h, expression of the aiiA gene in PAO1 completely degraded the quorum sensing autoinducers N-acylhomoserine lactones (AHLs): N-oxododecanoyl-L-homoserine lactone (OdDHL) and N-butyryl-L-homoserine lactone (BHL). The re- duced amount of AHLs in PAO1 was also correlated with decreased expression and production of several virulence factors such as elastase and pyocyanin. AiiA expression also influenced bacterial swarming motility. Most importantly, our studies indicated that aiiA played significant roles in P. aeruginosa biofilm formation and dispersion, as observed by the differences of the biofilm formation on liquid and solid surfaces, and biofilm structures under a scanning electron microscope.

  6. Anaerobic degradation of long-chain alkylamines by a denitrifying Pseudomonas stutzeri.

    Science.gov (United States)

    Nguyen, Phuong D; van Ginkel, Cornelis G; Plugge, Caroline M

    2008-10-01

    The anaerobic degradation of tetradecylamine and other long-chain alkylamines by a newly isolated denitrifying bacterium was studied. Strain ZN6 was isolated from a mixture of soil and active sludge and was identified as representing Pseudomonas stutzeri, based on partial 16S rRNA gene sequence analysis. Strain ZN6 was a mesophilic, motile, Gram-negative rod-shaped bacterium and was able to grow on a variety of compounds including even-numbered primary fatty amines with alkyl chains ranging from C(4) to C(18) coupled to nitrate reduction. Alkylamines were used as sole carbon, energy and nitrogen source and were completely mineralized. Nitrate was dissimilated by ZN6 to nitrite. When strain ZN6 was grown under nitrate limitation, nitrite was slowly dissimilated further. When cocultivated with the complete denitrifier Castellaniella defragens ZN3, anaerobic degradation under denitrifying of alkylamines by strain ZN6 was slightly faster. Strain ZN3 is a complete denitrifier, unable to convert tetradecylamine, and was copurified from the same enrichment culture as strain ZN6. The proposed pathway for the degradation of alkylamines in strain ZN6 starts with C-N cleavages to alkanals and further oxidation to the corresponding fatty acids.

  7. A study on metabolic prowess of Pseudomonas sp. RPT 52 to degrade imidacloprid, endosulfan and coragen.

    Science.gov (United States)

    Gupta, Manasi; Mathur, Samarth; Sharma, Tarun K; Rana, Manish; Gairola, Ajay; Navani, Naveen K; Pathania, Ranjana

    2016-01-15

    A bacterial strain identified as Pseudomonas sp. RPT 52, was isolated from an agricultural field by soil enrichment technique. The bacterial strain was able to metabolize three different chlorinated pesticides; imidacloprid, endosulfan and coragen (belonging to neonicotinoid, organochlorine and anthranillic diamide categories, respectively). RPT 52 was able to degrade 46.5%, 96.6%, 92.7% and 80.16% of 0.5 mM of imidacloprid, endosulfan α, endosulfan β and coragen, respectively, in minimal medium over a period of 40 h, when provided as sole source of carbon and energy. Degradation kinetics showed that imidacloprid, endosulfan α and endosulfan β followed first order kinetics whereas coragen followed zero order kinetics. Toxicity studies show reduction in toxicity of the parent compound when degraded by RPT 52. Laboratory scale, soil microcosm studies showed that strain RPT 52 is a suitable candidate for bioremediation of endosulfan and coragen contaminated sites. Thus, RPT 52 holds potential for toxicity reduction in the affected environment.

  8. Degradation of phenanthrene and pyrene using genetically engineered dioxygenase producing Pseudomonas putida in soil

    Directory of Open Access Journals (Sweden)

    Mardani Gashtasb

    2016-01-01

    Full Text Available Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p0.05 but it was few impact on this process (more than 2%. Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted environments.

  9. Aerobic TCE degradation by encapsulated toluene-oxidizing bacteria, Pseudomonas putida and Bacillus spp.

    Science.gov (United States)

    Kim, Seungjin; Bae, Wookeun; Hwang, Jungmin; Park, Jaewoo

    2010-01-01

    The degradation rates of toluene and trichloroethylene (TCE) by Pseudomonas putida and Bacillus spp. that were encapsulated in polyethylene glycol (PEG) polymers were evaluated in comparison with the results of exposure to suspended cultures. PEG monomers were polymerized together with TCE-degrading microorganisms, such that the cells were encapsulated in and protected by the matrices of the PEG polymers. TCE concentrations were varied from 0.1 to 1.5 mg/L. In the suspended cultures of P. putida, the TCE removal rate decreased as the initial TCE concentration increased, revealing TCE toxicity or a limitation of reducing power, or both. When the cells were encapsulated, an initial lag period of about 10-20 h was observed for toluene degradation. Once acclimated, the encapsulated P. putida cultures were more tolerant to TCE at an experimental range of 0.6-1.0 mg/L and gave higher transfer efficiencies (mass TCE transformed/mass toluene utilized). When the TCE concentration was low (e.g., 0.1 mg/L) the removal of TCE per unit mass of cells (specific removal) was significantly lower, probably due to a diffusion limitation into the PEG pellet. Encapsulated Bacillus spp. were able to degrade TCE cometabolically. The encapsulated Bacillus spp. gave significantly higher values than did P. putida in the specific removal and the transfer efficiency, particularly at relatively high TCE concentration of approximately 1.0±0.5 mg/L. The transfer efficiency by encapsulated Bacillus spp. in this study was 0.27 mgTCE/mgToluene, which was one to two orders of magnitude greater than the reported values.

  10. The Branched-Chain Dodecylbenzene Sulfonate Degradation Pathway of Pseudomonas aeruginosa W51D Involves a Novel Route for Degradation of the Surfactant Lateral Alkyl Chain

    OpenAIRE

    Campos-García, Jesús; Esteve, Abraham; Vázquez-Duhalt, Rafael; Ramos, Juán Luis; Soberón-Chávez, Gloria

    1999-01-01

    Pseudomonas aeruginosa W51D is able to grow by using branched-chain dodecylbenzene sulfonates (B-DBS) or the terpenic alcohol citronellol as a sole source of carbon. A mutant derived from this strain (W51M1) is unable to degrade citronellol but still grows on B-DBS, showing that the citronellol degradation route is not the main pathway involved in the degradation of the surfactant alkyl moiety. The structures of the main B-DBS isomers and of some intermediates were identified by gas chromatog...

  11. The Branched-Chain Dodecylbenzene Sulfonate Degradation Pathway of Pseudomonas aeruginosa W51D Involves a Novel Route for Degradation of the Surfactant Lateral Alkyl Chain

    Science.gov (United States)

    Campos-García, Jesús; Esteve, Abraham; Vázquez-Duhalt, Rafael; Ramos, Juán Luis; Soberón-Chávez, Gloria

    1999-01-01

    Pseudomonas aeruginosa W51D is able to grow by using branched-chain dodecylbenzene sulfonates (B-DBS) or the terpenic alcohol citronellol as a sole source of carbon. A mutant derived from this strain (W51M1) is unable to degrade citronellol but still grows on B-DBS, showing that the citronellol degradation route is not the main pathway involved in the degradation of the surfactant alkyl moiety. The structures of the main B-DBS isomers and of some intermediates were identified by gas chromatography-mass spectrometric analysis, and a possible catabolic route is proposed. PMID:10427075

  12. Enhanced cometabolic degradation of methyl tert-butyl ether by a Pseudomonas sp. strain grown on n-pentane

    Science.gov (United States)

    Li, S. S.; Wang, S.; Yan, W.

    2016-08-01

    When methyl tert-butyl ether (MTBE) is added as oxygenates it increases the octane number and decreases the release of nitric oxide from the incomplete combustion of reformulated gasoline. The extensive use of MTBE allowed it to be detectable as a pollutant in both ground-level and underground water worldwide. The present study focuses on the isolation and characterization of MTB-degrading microorganisms by cometabolism based on the results of growth on different carbon sources. It also focuses on the kinetic analysis and the continuous degradation of MTBE. A bacterial strain WL1 that can grow on both n-alkanes (C5-C8) and aromatics was isolated and named Pseudomonas sp. WL1 according to the 16S rDNA sequencing analysis. Strain WL1 could cometabolically degrade MTBE in the presence of n-alkanes with a desirable degradation rate. Diverse n-alkanes with different lengths of carbon chains showed significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When strain WL1 cometabolically degraded MTBE in the presence of n-pentane, higher MTBE-degrading rate and lower TBA-accumulation were observed (Vmax = 38.1 nmol/min/mgprotei, Ks = 6.8 mmol/L). In the continuous degrading experiment, the removal efficiency of MTBE by Pseudomonas sp. WL1 did not show any obvious decrease after five subsequent additions.

  13. Pentachlorophenol degradation by Pseudomonas stutzeri CL7 in the secondary sludge of pulp and paper mill

    Institute of Scientific and Technical Information of China (English)

    Santosh Kr.Karn; S.K.Chakrabarty; M.S.Reddy

    2010-01-01

    A pentachlorophenol (PCP) mineralizing bacterium was isolated from the secondary sludge of pulp and paper mill and identified as Pseudomonas stutzeri strain CL7.This isolate used PCP as its sole source of carbon and energy and was capable of degrading this compound as indicated by stoichiometric release of chloride and biomass formation.P.stutzeri (CL7) was able to mineralize a high concentration of PCP (600 mg/L) than any previously reported Pseudomonad with PCP as sole carbon source.As the concentration of PCP increased from 50 to 600 mg/L,the reduction in the cell growth was observed and the PCP degradation was more than 90% in all studied concentrations.This isolate was able to remove 66.8% of PCP from the secondary sludge of pulp and paper mill when supplemented with 100 mg/L of PCP and grown for two weeks.This study showed that the removal efficiency of PCP by CL7 was found to be very effective and can be used in PCP remediation of pulp paper mill waste in the environment.

  14. Biosurfactant production by Pseudomonas fluorescens growing on molasses and its application in phenol degradation

    Science.gov (United States)

    Suryantia, Venty; Marliyana, Soerya Dewi; Wulandari, Astri

    2015-12-01

    A molasses based medium for the biosurfactant production by Pseudomonas fluorescens was developed, where the effect of pre-treated of molasses and medium composition were evaluated. Biosurfactant production was followed by measuring optical density (OD), surface tension and emulsifying index (E24) over 12 days of fermentation. The optimum condition for the biosurfactant production was obtained when a medium containing of 8 g/L nutrient broth, 5 g/L NaCl, 1 g/L NH4NO3 and 5% v/v pre-treated molasses with centrifugation was used as media with 3 days of fermentation. The biosurfactant was identified as a rhamnolipid type biosurfactant which had critical micelle concentration (CMC) value of 801 mg/L and was able to reduce the surface tension of the water from 80 mN/m to 51 mN/m. The biosurfactants had water in oil (w/o) emulsion type. Biosurfactant was able to emulsify various hydrocarbons, which were able to decrase the interfacial tension about 50-75% when benzyl chloride, anisaldehyde and palm oil were used as immiscible compounds. The biosurfactant exhibited the E24 value of about 50% and the stable emulsion was reached up to 30 days when lubricant was used as an immiscible compound. Up to 68% of phenol was degraded in the presence of biosurfactant within 15 days, whereas only 56% of phenol was degraded in the absence of biosurfactant. Overall, the results exhibited that molasses are recommended for the rhamnolipids production which possessed good surface-active properties and had potential application in the enhancement of phenol degradation.

  15. Pseudomonas aeruginosa elastase provides an escape from phagocytosis by degrading the pulmonary surfactant protein-A.

    Directory of Open Access Journals (Sweden)

    Zhizhou Kuang

    Full Text Available Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute pneumonitis in immunocompromised patients and chronic lung infections in individuals with cystic fibrosis and other bronchiectasis. Over 75% of clinical isolates of P. aeruginosa secrete elastase B (LasB, an elastolytic metalloproteinase that is encoded by the lasB gene. Previously, in vitro studies have demonstrated that LasB degrades a number of components in both the innate and adaptive immune systems. These include surfactant proteins, antibacterial peptides, cytokines, chemokines and immunoglobulins. However, the contribution of LasB to lung infection by P. aeruginosa and to inactivation of pulmonary innate immunity in vivo needs more clarification. In this study, we examined the mechanisms underlying enhanced clearance of the ΔlasB mutant in mouse lungs. The ΔlasB mutant was attenuated in virulence when compared to the wild-type strain PAO1 during lung infection in SP-A+/+ mice. However, the ΔlasB mutant was as virulent as PAO1 in the lungs of SP-A⁻/⁻ mice. Detailed analysis showed that the ΔlasB mutant was more susceptible to SP-A-mediated opsonization but not membrane permeabilization. In vitro and in vivo phagocytosis experiments revealed that SP-A augmented the phagocytosis of ΔlasB mutant bacteria more efficiently than the isogenic wild-type PAO1. The ΔlasB mutant was found to have a severely reduced ability to degrade SP-A, consequently making it unable to evade opsonization by the collectin during phagocytosis. These results suggest that P. aeruginosa LasB protects against SP-A-mediated opsonization by degrading the collectin.

  16. Isolation and identification of the acetonitrile-degrading Pseudomonas from the Ab-anbar-e Ganjali Khan in Kerman

    Directory of Open Access Journals (Sweden)

    Narjes Ramezani–pour

    2016-06-01

    Full Text Available Introduction: Nitriles are toxic and hazardous compounds for all organisms which are produced enormously by human being and cause environment pollution. Biodegradation is the best method for Nitrile elimination in sewage. The aim of this study was isolation and identification of native bacteria Acetonitrile-degrading from the sewage of the city of Kerman. Materials and methods: The enrichment and screening of Acetonitrile degrading bacteria was performed in a specific medium containing 1 % Acetonitrile as sole carbon and nitrogen source. Enzyme activity and ammonium production was determined in growth medium using a modification of the phenol/hypochlorite method. Identification of the isolates was undertaken using microbial - biochemical and molecular tests. The optimization of enzyme production was examined. The amount of nitrile and acid were also determined by gas chromatography. Results: Among three isolated nitrile hydrolyzing producing species (FA3, FA8 and AB19, FA8 isolate showed maximum enzyme productivity. The results of characteristic tests showed that these bacteria belonged to the Pseudomonas sp. Moreover, 16S rRNA sequencing and phylogenetic analyses exhibited that FA11, FA8 and AB19 strains were similar to Pseudomonas Otitidis and Pseudomonas geniculate with 99, 100% homology, respectively. Results of medium optimization of Pseudomonas FA8 strain showed that glucose (10 gL-1 and yeast extract (5 gL-1 in neutral medium strongly supported enzyme production. Gas chromatography results showed that FA8 produced 58% acetic acid at 48 h of incubation. Discussion and conclusion: The results demonstrated that Pseudomonas FA8 isolated bacterium is a suitable candidate for degradation of Acetonitrile. This bacterium could be used for treatment of industrial wastewater and sites that contaminated with Acetonitrile.

  17. Activity of toluene-degrading Pseudomonas putida in the early growth phase of a biofilm for waste gas treatment

    DEFF Research Database (Denmark)

    Pedersen, A.R.; Møller, S.; Molin, S.

    1997-01-01

    in the biofilm. Based on the rRNA content, the in situ activity was estimated to be reduced to 20% of cells grown at maximum conditions in batch culture. The toluene degraded by P. putida was estimated to be a minor part (11%) of the overall toluene degradation. (C) 1997 John Wiley & Sons, Inc.......A biological trickling filter for treatment of toluene-containing waste gas was studied. The overall kinetics of the biofilm growth was followed in the early growth phase. A rapid initial colonization took place during the first three days. The biofilm thickness increased exponentially, whereas...... the increase of active biomass and polymers was linear. In order to investigate the toluene degradation, various toluene degraders from the multispecies biofilm were isolated, and a Pseudomonas putida was chosen as a representative of the toluene-degrading population. A specific rRNA oligonucleotide probe...

  18. Degradation of o-chloronitrobenzene as the sole carbon and nitrogen sources by Pseudomonas putida OCNB-1

    Institute of Scientific and Technical Information of China (English)

    WU Haizhen; WEI Chaohai; WAMG Yaqin; HE Qincong; LIANG Shizhong

    2009-01-01

    A bacterial strain that utilized o-chloronitrobenzene (o-CNB) as the sole carbon, nitrogen and energy sources was isolated from an activated sludge collected from an industrial waste treatment plant. It was identified as Pseudomonas putida based on its morphology, physiological, and biochemical characteristics with an automatic biometrical system and the 16S rRNA sequence analysis. Microcosm study showed that the biodegradation of o-CNB was optimized at culture medium pH 8.0 and temperature of 32℃. At these conditions, the strain degraded 85% of o-CNB at a starting concentration of 1.1 mmol/L in 42 h. o-Chloroaniline was identified as the major metabolite with both high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The study showed that o-chloronitrobenzene degradation by Pseudomonas putida OCNB-1 was initiated by aniline dioxyenase, nitrobenzene reductase and catechol-1,2-dioxygenase.

  19. Photolumincscent Properties of Polyacetylenes Carbazole

    Institute of Scientific and Technical Information of China (English)

    XUE Qing; HUANG Yuan-ming

    2007-01-01

    The optical properties of one mono-substituted polyacetylene and two di-substituted polyacetylenes have been investigated. Each of the substituted polyacetylenes bears a carbazole unit in the side chain. In spite of the differences in their molecular structures, the dilute solutions(about 1×10-6 M) of these substituted polyacetylenes exhibit the same absorptions and deep-blue emissions(about 360 nm). Interestingly, the absorption and emission spectra of these substituted polyacetylenes are similar to those of the small molecule carbazole. As the concentration of the substituted polyacetylenes increases to about 1×10-6 M, we have detected intense blue emissions at about 475 nm. Our results indicate that the absorption, the deep-blue emission(about 360 nm) and the intense blue emission(about 475 nm) originate from the carbazole chromophores in the side chain.

  20. Rhamnolipid from Pseudomonas desmolyticum NCIM-2112 and its role in the degradation of Brown 3REL.

    Science.gov (United States)

    Jadhav, Mital; Kalme, Satish; Tamboli, Dhawal; Govindwar, Sanjay

    2011-08-01

    The biosurfactant produced by Pseudomonas desmolyticum NCIM 2112 (Pd 2112) was confirmed as rhamnolipid based on the formation of dark blue halos around the colonies in CTAB-methylene blue agar plates and the content of rhamnose sugar. The average yield of rhamnolipid was 0.398 g/l/day when grown on hexadecane as sole carbon source. Pd 2112 emulsification potential associated with cell free culture broth was stable for 72 h using various hydrocarbons and vegetable oils. Chemical structure of the biosurfactant was identified as mono-rhamnolipid (Rha-C(6) -C(8) ) using HPTLC, fourier transform infrared spectroscopy, (1) H and (13) C NMR and gas chromatography-mass spectroscopy analysis. Pd 2112 mono-rhamnolipid (1 mg/ml) had increased permeabilization of Bacillus sp VUS NCIM 5342 and increased decolorization rate of textile dye Brown 3REL by 50%. Extracellular activities of lignin peroxidase and veratryl alcohol oxidase, enzymes involved in dye degradation, were significantly increased in the presence of mono-rhamnolipid by 324.52% and 100% respectively. Scanning electron micro-scopy observations revealed that rhamnolipid did not exert any disruptive action on Bacillus cells as compared to Tween 80. The mono-rhamnolipid of Pd 2112 has potential for its application in biodegradation of textile dyes.

  1. Statistical optimization of synthetic azo dye (orange II) degradation by azoreductase from Pseudomonas oleovorans PAMD_1.

    Science.gov (United States)

    Aranganathan, V; Kanimozhi, A M; Palvannan, T

    2013-01-01

    Pseudomonas oleovorans PAMD_1 produced an intracellular azoreductase as the more prominent enzyme that reduces the azo bridge during the azo dye decolorization process. In order to optimize the expression of azoreductase, statistically based experiments were applied. Eleven significant factors were screened on decolorization activity using Plackett-Burman design. Dye, NADH, glucose, and peptone were identified as having highest positive influence on the decolorization activity. Central composite design of response surface methodology was employed for the concerted effect of these four factors on decolorization activity. This method showed that the optimum medium containing dye (200 mg L(-1)), NADH (1.14 mM), glucose (2.07 g L(-1)), and peptone (6.44 g L(-1)) for the decolorization of Orange II up to 87% in 48 hr. The applied methodology was validated through the adequacy and accuracy of the overall experiments, and the results proved that the applied methods were most effective. Further, the enzyme was purified ninefold with 16% yield by anion-exchange chromatography and a specific activity of 26 U mg(-1). The purified enzyme with a molecular mass of 29,000 Da gave a single band on sodium dodecyl sulfate (SDS) gel, and the degradation products sulfanilic acid and 1-amino-2-napthol of Orange II by azoreductase were analyzed by using an ultraviolet-visible (UV-Vis) spectrophotometer and hish-performance liquid chromatography (HPLC).

  2. Characterization of a sodium dodecyl sulphate-degrading Pseudomonas sp. strain DRY15 from Antarctic soil.

    Science.gov (United States)

    Halmi, M I E; Hussin, W S W; Aqlima, A; Syed, M A; Ruberto, L; MacCormack, W P; Shukor, M Y

    2013-11-01

    A bacterium capable of biodegrading surfactant sodium dodecyl sulphate (SDS) was isolated from Antarctic soil. The isolate was tentatively identified as Pseudomonas sp. strain DRY15 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Growth characteristic studies showed that the bacterium grew optimally at 10 degrees C, 7.25 pH, 1 g l(-1) SDS as a sole carbon source and 2 g l(-1) ammonium sulphate as nitrogen source. Growth was completely inhibited at 5 g l(-1) SDS. At a tolerable initial concentration of 2 g l(-1), approximately 90% of SDS was degraded after an incubation period of eight days. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibition with a correlation coefficient value of 0.97. The maximum growth rate was 0.372 hr(-1) while the saturation constant or half velocity constant (Ks) and inhibition constant (Ki), were 0.094% and 11.212 % SDS, respectively. Other detergent tested as carbon sources at 1 g l(-1) was Tergitol NP9, Tergitol 15S9, Witconol 2301 (methyl oleate), sodium dodecylbenzene sulfonate (SDBS), benzethonium chloride, and benzalkonium chloride showed Tergitol NP9, Tergitol 15S9, Witconol 2301 and the anionic SDBS supported growth with the highest growth exhibited by SDBS.

  3. Polycyclic aromatic hydrocarbon degradation by biosurfactant-producing Pseudomonas sp. IR1

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela); Synthesis and Biotics Div., Indian Oil Corp., Research and Development Center, Haryana (India); Leon, V.; Materano, A.D.S.; Ilzins, O.A.; Galindo-Castro, I.; Fuenmayor, S.L. [Unidad de Biotecnologia del Petroleo, Centro de Biotecnologia, Fundacion Inst. de Estudios Avanzados (IDEA), Caracas (Venezuela)

    2006-03-15

    We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source. PCR and DNA hybridization studies showed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by IR1 during growth on both water miscible and immiscible substrates. The biosurfactants lowered the surface tension of medium from 54.9 dN cm{sup -1} to 35.4 dN cm{sup -1} and formed a stable and compact emulsion with an emulsifying activity of 74% with diesel oil, when grown on dextrose. These findings indicate that this isolate may be useful for bioremediation of sites contaminated with aromatic hydrocarbons. (orig.)

  4. Comparative genome analysis of Pseudomonas knackmussii B13, the first bacterium known to degrade chloroaromatic compounds.

    Science.gov (United States)

    Miyazaki, Ryo; Bertelli, Claire; Benaglio, Paola; Canton, Jonas; De Coi, Nicoló; Gharib, Walid H; Gjoksi, Bebeka; Goesmann, Alexander; Greub, Gilbert; Harshman, Keith; Linke, Burkhard; Mikulic, Josip; Mueller, Linda; Nicolas, Damien; Robinson-Rechavi, Marc; Rivolta, Carlo; Roggo, Clémence; Roy, Shantanu; Sentchilo, Vladimir; Siebenthal, Alexandra Von; Falquet, Laurent; van der Meer, Jan Roelof

    2015-01-01

    Pseudomonas knackmussii B13 was the first strain to be isolated in 1974 that could degrade chlorinated aromatic hydrocarbons. This discovery was the prologue for subsequent characterization of numerous bacterial metabolic pathways, for genetic and biochemical studies, and which spurred ideas for pollutant bioremediation. In this study, we determined the complete genome sequence of B13 using next generation sequencing technologies and optical mapping. Genome annotation indicated that B13 has a variety of metabolic pathways for degrading monoaromatic hydrocarbons including chlorobenzoate, aminophenol, anthranilate and hydroxyquinol, but not polyaromatic compounds. Comparative genome analysis revealed that B13 is closest to Pseudomonas denitrificans and Pseudomonas aeruginosa. The B13 genome contains at least eight genomic islands [prophages and integrative conjugative elements (ICEs)], which were absent in closely related pseudomonads. We confirm that two ICEs are identical copies of the 103 kb self-transmissible element ICEclc that carries the genes for chlorocatechol metabolism. Comparison of ICEclc showed that it is composed of a variable and a 'core' region, which is very conserved among proteobacterial genomes, suggesting a widely distributed family of so far uncharacterized ICE. Resequencing of two spontaneous B13 mutants revealed a number of single nucleotide substitutions, as well as excision of a large 220 kb region and a prophage that drastically change the host metabolic capacity and survivability.

  5. Degradation of malathion by Pseudomonas during activated sludge treatment system using principal component analysis (PCA)

    Institute of Scientific and Technical Information of China (English)

    Hashmi Imran; Khan M Altaf; Kim Jong-Guk

    2006-01-01

    Popular descriptive multivariate statistical method currently employed is the principal component analyses (PCA) method.PCA is used to develop linear combinations that successively maximize the total variance of a sample where there is no known group structure. This study aimed at demonstrating the performance evaluation of pilot activated sludge treatment system by inoculating a strain of Pseudomonas capable of degrading malathion which was isolated by enrichment technique. An intensive analytical program was followed for evaluating the efficiency of biosimulator by maintaining the dissolved oxygen (DO) concentration at 4.0 mg/L.Analyses by high performance liquid chromatographic technique revealed that 90% of malathion removal was achieved within 29 h of treatment whereas COD got reduced considerably during the treatment process and mean removal efficiency was found to be 78%.The mean pH values increased gradually during the treatment process ranging from 7.36-8.54. Similarly the mean ammonia-nitrogen (NH3-N) values were found to be fluctuating between 19.425-28.488 mg/L, mean nitrite-nitrogen (NO3-N) ranging between 1.301-2.940 mg/L and mean nitrate-nitrogen (NO3-N) ranging between 0.0071-0.0711 mg/L. The study revealed that inoculation of bacterial culture under laboratory conditions could be used in bioremediation of environmental pollution caused by xenobiotics. The PCA analyses showed that pH, COD, organic load and total malathion concentration were highly correlated and emerged as the variables controlling the first component, whereas dissolved oxygen, NO3-N and NH3-N govemed the second component. The third component repeated the trend exhibited by the first two components.

  6. Degradation of Benzene by Pseudomonas veronii 1YdBTEX2 and 1YB2 Is Catalyzed by Enzymes Encoded in Distinct Catabolism Gene Clusters

    Science.gov (United States)

    de Lima-Morales, Daiana; Chaves-Moreno, Diego; Wos-Oxley, Melissa L.; Jáuregui, Ruy; Vilchez-Vargas, Ramiro

    2015-01-01

    Pseudomonas veronii 1YdBTEX2, a benzene and toluene degrader, and Pseudomonas veronii 1YB2, a benzene degrader, have previously been shown to be key players in a benzene-contaminated site. These strains harbor unique catabolic pathways for the degradation of benzene comprising a gene cluster encoding an isopropylbenzene dioxygenase where genes encoding downstream enzymes were interrupted by stop codons. Extradiol dioxygenases were recruited from gene clusters comprising genes encoding a 2-hydroxymuconic semialdehyde dehydrogenase necessary for benzene degradation but typically absent from isopropylbenzene dioxygenase-encoding gene clusters. The benzene dihydrodiol dehydrogenase-encoding gene was not clustered with any other aromatic degradation genes, and the encoded protein was only distantly related to dehydrogenases of aromatic degradation pathways. The involvement of the different gene clusters in the degradation pathways was suggested by real-time quantitative reverse transcription PCR. PMID:26475106

  7. Genome Sequence of Pseudomonas sp. Strain Chol1, a Model Organism for the Degradation of Bile Salts and Other Steroid Compounds

    KAUST Repository

    Holert, Johannes

    2013-01-15

    Bacterial degradation of steroid compounds is of high ecological and biotechnological relevance. Pseudomonas sp. strain Chol1 is a model organism for studying the degradation of the steroid compound cholate. Its draft genome sequence is presented and reveals one gene cluster responsible for the metabolism of steroid compounds.

  8. Engineering Pseudomonas putida KT2440 for simultaneous degradation of organophosphates and pyrethroids and its application in bioremediation of soil.

    Science.gov (United States)

    Zuo, Zhenqiang; Gong, Ting; Che, You; Liu, Ruihua; Xu, Ping; Jiang, Hong; Qiao, Chuanling; Song, Cunjiang; Yang, Chao

    2015-06-01

    Agricultural soils are usually co-contaminated with organophosphate (OP) and pyrethroid pesticides. To develop a stable and marker-free Pseudomonas putida for co-expression of two pesticide-degrading enzymes, we constructed a suicide plasmid with expression cassettes containing a constitutive promoter J23119, an OP-degrading gene (mpd), a pyrethroid-hydrolyzing carboxylesterase gene (pytH) that utilizes the upp gene as a counter-selectable marker for upp-deficient P. putida. By introduction of suicide plasmid and two-step homologous recombination, both mpd and pytH genes were integrated into the chromosome of a robust soil bacterium P. putida KT2440 and no selection marker was left on chromosome. Functional expression of mpd and pytH in P. putida KT2440 was demonstrated by Western blot analysis and enzyme activity assays. Degradation experiments with liquid cultures showed that the mixed pesticides including methyl parathion, fenitrothion, chlorpyrifos, permethrin, fenpropathrin, and cypermethrin (0.2 mM each) were degraded completely within 48 h. The inoculation of engineered strain (10(6) cells/g) to soils treated with the above mixed pesticides resulted in a higher degradation rate than in noninoculated soils. All six pesticides could be degraded completely within 15 days in fumigated and nonfumigated soils with inoculation. Theses results highlight the potential of the engineered strain to be used for in situ bioremediation of soils co-contaminated with OP and pyrethroid pesticides.

  9. Effect of corn plant on survival and phenanthrene degradation capacity of Pseudomonas sp. UG14LR in two soils.

    Science.gov (United States)

    Chouychai, Waraporn; Thongkukiatkul, Amporn; Upatham, Suchart; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Lee, Hung

    2012-07-01

    A study was undertaken to assess if corn (Zea mays L.) can enhance phenanthrene degradation in two soils inoculated with Pseudomonas sp. UG14Lr. Corn increased the number of UG14Lr cells in both soils, especially in the acidic soiL Phenanthrene was degraded to a greater extent in UG14Lr-inoculated or corn-planted soils than uninoculated and unplanted soils. The spiked phenanthrene was completely removed within 70 days in all the treatments in slightly alkaline soil. However, in acidic soil, complete phenanthrene removal was found only in the corn-planted treatments. The shoot and root lengths of corn grown in UG14Lr-inoculated soils were not different from those in non-inoculated soil between the treatments. The results showed that in unplanted soil, low pH adversely affected the survival and phenanthrene degradation ability of UG14Lr. Planting of corn significantly enhanced the survival of UG14Lr cells in both the bulk and rhizospheric soil, and this in turn significantly improved phenanthrene degradation in acidic soil. Re-inoculation of UG14Lr in the acidic soil increased the number of UG14Lr cells and enhanced phenanthrene degradation in unplanted soil. However, in corn-planted acidic soils, re-inoculation of UG14Lr did not further enhance the already active phenanthrene degradation occurring in both the bulk or rhizospheric soils.

  10. Degradation of polycyclic aromatic hydrocarbons by Pseudomonas sp.JM2 isolated from active sewage sludge of chemical plant

    Institute of Scientific and Technical Information of China (English)

    Jing Ma; Li Xu; Lingyun Jia

    2012-01-01

    It is important to screen strains that can decompose polycyclic aromatic hydrocarbons (PAHs) completely and rapidly with good adaptability for bioremediation in a local area.A bacterial strain JM2,which uses phenanthrene as its sole carbon source,was isolated from the active sewage sludge from a chemical plant in Jilin,China and identified as Pseudomonas based on 16S rDNA gene sequence analysis.Although the optimal growth conditions were determined to be pH 6.0 and 37℃,JM2 showed a broad pH and temperature profile.At pH 4.5 and 9.3,JM2 could degrade more than 40% of fluorene and phenanthrene (50 mg/L each) within 4 days.In addition,when the temperature was as low as 4℃,JM2 could degrade up to 24% fluorene and 12% phenanthrene.This showed the potential for JM2 to be applied in bioremediation over winter or in cold regions.Moreover,a nutrient augmentation study showed that adding formate into media could promote PAH degradation,while the supplement of salicylate had an inhibitive effect.Furthermore,in a metabolic pathway study,salicylate,phthaiic acid,and 9-fluorenone were detected during the degradation of fluorene or phenanthrene.In conclusion,Pseudomonas sp.JM2 is a high performance strain in the degradation of fluorene and phenanthrene under extreme pH and temperature conditions.It might be useful in the bioremediation of PAHs.

  11. Aerobic degradation of N-methyl-4-nitroaniline (MNA by Pseudomonas sp. strain FK357 isolated from soil.

    Directory of Open Access Journals (Sweden)

    Fazlurrahman Khan

    Full Text Available N-Methyl-4-nitroaniline (MNA is used as an additive to lower the melting temperature of energetic materials in the synthesis of insensitive explosives. Although the biotransformation of MNA under anaerobic condition has been reported, its aerobic microbial degradation has not been documented yet. A soil microcosms study showed the efficient aerobic degradation of MNA by the inhabitant soil microorganisms. An aerobic bacterium, Pseudomonas sp. strain FK357, able to utilize MNA as the sole carbon, nitrogen, and energy source, was isolated from soil microcosms. HPLC and GC-MS analysis of the samples obtained from growth and resting cell studies showed the formation of 4-nitroaniline (4-NA, 4-aminophenol (4-AP, and 1, 2, 4-benzenetriol (BT as major metabolic intermediates in the MNA degradation pathway. Enzymatic assay carried out on cell-free lysates of MNA grown cells confirmed N-demethylation reaction is the first step of MNA degradation with the formation of 4-NA and formaldehyde products. Flavin-dependent transformation of 4-NA to 4-AP in cell extracts demonstrated that the second step of MNA degradation is a monooxygenation. Furthermore, conversion of 4-AP to BT by MNA grown cells indicates the involvement of oxidative deamination (release of NH2 substituent reaction in third step of MNA degradation. Subsequent degradation of BT occurs by the action of benzenetriol 1, 2-dioxygenase as reported for the degradation of 4-nitrophenol. This is the first report on aerobic degradation of MNA by a single bacterium along with elucidation of metabolic pathway.

  12. Pseudomonas A1 influences the formation of hydroxyapatite and degrades bioglass

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulou, E. [Laboratory of General Microbiology, Section of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Papadopoulou, L. [School of Geology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Paraskevopoulos, K.M. [Physics Department Solid State Physics Section, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Koidis, P. [Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Sivropoulou, A., E-mail: asivropo@bio.auth.g [Laboratory of General Microbiology, Section of Genetics, Development and Molecular Biology, School of Biology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)

    2009-12-15

    Bacterial infections frequently lead to hard tissue destructions. The purpose of the present study was to address the question as to how the bacteria destroy hard tissues with the use of an in vitro system. A bacterium was isolated from a solution simulating body fluid which was identified as Pseudomonas A1, and is able to solubilize tricalcium phosphate when it grows in IP broth. The presence of Pseudomonas A1 resulted in dose-dependent inhibition of the formation of hydroxyapatite layer, on the surface of bioglass specimens immersed in SBF solution, in contrast to the control. When the bioglass specimens were immersed in IP broth without Ca{sub 3}(PO{sub 4}){sub 2}, so as to be present the appropriate inorganic ions for the survival of Pseudomonas but the only source of phosphate be derived from bioactive glass specimens, the formation of hydroxyapatite layer was not observed in any specimen. Additionally the presence of Pseudomonas resulted in 93.4% (w/w) and 85.9% (w/w) reduction on the surface composition of Ca and P, respectively, and further the rate of the decrease of specimen's weight was almost 50% higher in the presence of Pseudomonas compared with the control.

  13. Degradation of polyurethane by bacterium isolated from soil and assessment of polyurethanolytic activity of a Pseudomonas putida strain.

    Science.gov (United States)

    Peng, Yu-Huei; Shih, Yang-hsin; Lai, Yen-Chun; Liu, Yuan-Zan; Liu, Ying-Tong; Lin, Nai-Chun

    2014-01-01

    The increasing usage and the persistence of polyester polyurethane (PU) generate significant sources of environmental pollution. The effective and environmental friendly bioremediation techniques for this refractory waste are in high demand. In this study, three novel PU degrading bacteria were isolated from farm soils and activated sludge. Based upon 16S ribosomal RNA gene sequence blast, their identities were determined. Particularly robust activity was observed in Pseudomonas putida; it spent 4 days to degrade 92% of Impranil DLN(TM) for supporting its growth. The optimum temperature and pH for DLN removal by P. putida were 25 °C and 8.4, respectively. The degradation and transformation of DLN investigated by Fourier transformed infrared spectroscopy show the decrease in ester functional group and the emergence of amide group. The polyurethanolytic activities were both presented in the extracellular fraction and in the cytosol. Esterase activity was detected in the cell lysate. A 45-kDa protein bearing polyurethanolytic activity was also detected in the extracellular medium. This study presented high PU degrading activity of P. putida and demonstrated its responsible enzymes during the PU degradation process, which could be applied in the bioremediation and management of plastic wastes.

  14. 21 CFR 73.3107 - Carbazole violet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Carbazole violet. 73.3107 Section 73.3107 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... additive is carbazole violet (Pigment Violet 23) (CAS Reg. No. 6358-30-1, Colour Index No. 51319). (b)...

  15. Pseudomonas and Beyond: Polyamine metabolism, lignin degradation and potential applications in industrial biotechnology

    NARCIS (Netherlands)

    Bandounas, L.

    2011-01-01

    Renewable resources such as lignocellulosic biomass are promising feedstocks for the production of bio-fuels and value-added products. Biocatalysts are considered important tools in such processes. Pseudomonas putida S12 has a broad metabolic potential and is exceptionally tolerant towards a range o

  16. Degradation of Tectilon Yellow 2G by hybrid technique: combination of sonolysis and biodegradation using mutant Pseudomonas putida.

    Science.gov (United States)

    Srinivasan, Raman; Kathiravan, Mathur Nadarajan; Gopinath, Kannappan Panchamoorthy

    2011-02-01

    Degradation of Tectilon Yellow 2G (TY2G), an azo dye has been studied by hybrid technique involving pretreatment by sonochemical method and further biological treatment by Pseudomonas putida mutant. Pretreatment experiments were carried out by sonolysis of the dye solution at different concentrations (100-1000 mg/L). Wild type Gram-negative P. putida species isolated from the textile effluent contaminated soil, which was found to be effective towards dye degradation, has been acclimatized so as to consume TY2G as the sole source of nutrition. Mutant strain was obtained from the acclimatized species by random mutagenesis using the chemical mutagen ethidium bromide for various time intervals (6-30 min). The optimum mutagenesis exposure time for obtaining the most efficient species for dye degradation was found to be 18 min. An efficient mutant strain P. putida ACT 1 has been isolated and was used for growth experiments. The mutant strain showed a better growth compared to the wild strain. The substrate utilization kinetics has been modeled using Monod and Haldane model equations of which the Haldane model provided a better fit. The enzyme kinetics of the mutant and wild species was obtained using Michaelis-Menten equation. The mutated species showed better enzyme kinetics towards the degradation of TY2G.

  17. Draft Genome Sequences of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8, Soil Bacteria That Cooperate To Degrade the Poly-γ-d-Glutamic Acid Anthrax Capsule.

    Science.gov (United States)

    Stabler, Richard A; Negus, David; Pain, Arnab; Taylor, Peter W

    2013-01-01

    A mixed culture of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8 degraded poly-γ-d-glutamic acid; when the 2 strains were cultured separately, no hydrolytic activity was apparent. Here we report the draft genome sequences of both soil isolates.

  18. Draft Genome Sequences of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8, Soil Bacteria That Cooperate To Degrade the Poly- -D-Glutamic Acid Anthrax Capsule

    KAUST Repository

    Stabler, R. A.

    2013-01-24

    A mixed culture of Pseudomonas fluorescens BS2 and Pusillimonas noertemannii BS8 degraded poly-γ-d-glutamic acid; when the 2 strains were cultured separately, no hydrolytic activity was apparent. Here we report the draft genome sequences of both soil isolates.

  19. NUCLEOTIDE SEQUENCING AND TRANSCRIPTIONAL MAPPING OF THE GENES ENCODING BIPHENYL DIOXYGENASE, A MULTICOM- PONENT POLYCHLORINATED-BIPHENYL-DEGRADING ENZYME IN PSEUDOMONAS STRAIN LB400

    Science.gov (United States)

    The DNA region encoding biphenyl dioxygenase, the first enzyme in the biphenyl-polychlorinated biphenyl degradation pathway of Pseudomonas species strain LB400, was sequenced. Six open reading frames were identified, four of which are homologous to the components of toluene dioxy...

  20. Isolation of a Pseudomonas aeruginosa strain from soil that can degrade polyurethane diol.

    Science.gov (United States)

    Mukherjee, Koushik; Tribedi, Prosun; Chowdhury, Arup; Ray, Tanusree; Joardar, Archi; Giri, Subhajit; Sil, Alok Kumar

    2011-04-01

    Polyurethane diol (PUR-diol), a synthetic polymer, is widely used as a modifier for water-soluble resins and emulsions in wood appliances and auto coatings. Non-biodegradability of polyurethanes (PUR) and PUR-based materials poses a threat to environment that has led scientists to isolate microbes capable of degrading PUR. However, the bio-degradation of PUR-diol has not yet been reported. In this study, we report isolation of a soil bacterium that can survive using PUR-diol as sole carbon source. PUR-diol degradation by the organism was confirmed by thin layer chromatographic analysis of the conditioned medium obtained after the growth wherein a significant reduction of PUR-diol was observed compared to non-inoculated medium. To quantify the PUR-diol degradation, a sensitive assay based on High Performance Thin Layer Chromatography has been developed that showed 32% degradation of PUR-diol by the organism in 10 days. Degradation kinetics showed the maximal depletion of PUR-diol during logarithmic growth of the organism indicating a direct relation between the growth and PUR-diol degradation. Mutagenic study and GC-MS analysis revealed that esterase activity is involved in this degradation event. The ribotyping and metabolic fingerprinting analysis showed that this organism is a strain of Pseudomonous aeruginosa (P. aeruginosa). It has also been observed that this strain is able to degrade Impranil DLN™, a variety of commercially available PUR. Therefore this study identifies a new bacterium from soil that has the potential to reduce PUR-related waste burden and adds a new facet to diverse functional activities of P. aeruginosa.

  1. Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S. D.

    1998-12-01

    Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

  2. Draft whole genome sequence of the cyanide-degrading bacterium Pseudomonas pseudoalcaligenes CECT5344.

    Science.gov (United States)

    Luque-Almagro, Víctor M; Acera, Felipe; Igeño, Ma Isabel; Wibberg, Daniel; Roldán, Ma Dolores; Sáez, Lara P; Hennig, Magdalena; Quesada, Alberto; Huertas, Ma José; Blom, Jochen; Merchán, Faustino; Escribano, Ma Paz; Jaenicke, Sebastian; Estepa, Jessica; Guijo, Ma Isabel; Martínez-Luque, Manuel; Macías, Daniel; Szczepanowski, Rafael; Becerra, Gracia; Ramirez, Silvia; Carmona, Ma Isabel; Gutiérrez, Oscar; Manso, Isabel; Pühler, Alfred; Castillo, Francisco; Moreno-Vivián, Conrado; Schlüter, Andreas; Blasco, Rafael

    2013-01-01

    Pseudomonas pseudoalcaligenes CECT5344 is a Gram-negative bacterium able to tolerate cyanide and to use it as the sole nitrogen source. We report here the first draft of the whole genome sequence of a P. pseudoalcaligenes strain that assimilates cyanide. Three aspects are specially emphasized in this manuscript. First, some generalities of the genome are shown and discussed in the context of other Pseudomonadaceae genomes, including genome size, G + C content, core genome and singletons among other features. Second, the genome is analysed in the context of cyanide metabolism, describing genes probably involved in cyanide assimilation, like those encoding nitrilases, and genes related to cyanide resistance, like the cio genes encoding the cyanide insensitive oxidases. Finally, the presence of genes probably involved in other processes with a great biotechnological potential like production of bioplastics and biodegradation of pollutants also is discussed.

  3. Enhanced phenol degradation by Pseudomonas sp. SA01: Gaining insight into the novel single and hybrid immobilizations

    Energy Technology Data Exchange (ETDEWEB)

    Mollaei, Monir [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Abdollahpour, Saeeide [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Clinical Biochemistry, Faculty of Medicine, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Atashgahi, Siavash; Abbasi, Habib; Masoomi, Fatemeh; Rad, Iman [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Lotfi, Abbas Sahebghadam [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Department of Clinical Biochemistry, Faculty of Medicine, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Zahiri, Hossein Shahbani [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of); Vali, Hojatollah [Department of Anatomy and Cell Biology, McGill University, Montreal (Canada); Noghabi, Kambiz Akbari, E-mail: Akbari@nigeb.ac.ir [National Institute of Genetic Engineering and Biotechnology (NIGEB), P.O. Box 14155-6343, Tehran (Iran, Islamic Republic of)

    2010-03-15

    In this work, Pseudomonas sp. SA01 cells were immobilized in a series of singular and hybrid immobilization techniques to achieve enhanced phenol removal. The singular immobilization strategies consisted of various concentrations of alginate (2-4%) and pectin (3-5%), while the hybrid strategies incorporated polyvinyl alcohol (PVA)-alginate and glycerol-alginate beads and alginate-chitosan-alginate (ACA) capsules. Immobilization protected cells against phenol and resulted in remarkable reduction (65%) in degradation time by cells immobilized in either alginate (3%) beads, in a hybrid PVA-alginate beads, or in ACA capsules compared to freely suspended cells. Cells immobilized in PVA-alginate and ACA provided the best performance in experiments using elevated phenol concentrations, up to 2000 mg/L, with complete degradation of 2000 mg/L phenol after 100 and 110 h, respectively. Electron microscopy examination indicated that cell loading capacity was increased in PVA-alginate hybrid beads through reduced cell leakage, resulting in higher activity of PVA-alginate hybrid beads compared to all other immobilization methods.

  4. Isolation, plant colonization potential, and phenanthrene degradation performance of the endophytic bacterium Pseudomonas sp. Ph6-gfp

    Science.gov (United States)

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Jin, Li; Gu, Yujun; Wang, Wanqing

    2014-06-01

    This investigation provides a novel method of endophyte-aided removal of polycyclic aromatic hydrocarbons (PAHs) from plant bodies. A phenanthrene-degrading endophytic bacterium Pseudomonas sp. Ph6 was isolated from clover (Trifolium pratense L.) grown in a PAH-contaminated site. After being marked with the GFP gene, the colonization and distribution of strain Ph6-gfp was directly visualized in plant roots, stems, and leaves for the first time. After ryegrass (Lolium multiflorum Lam.) roots inoculation, strain Ph6-gfp actively and internally colonized plant roots and transferred vertically to the shoots. Ph6-gfp had a natural capacity to cope with phenanthrene in vitro and in planta. Ph6-gfp degraded 81.1% of phenanthrene (50 mg.L-1) in a culture solution within 15 days. The inoculation of plants with Ph6-gfp reduced the risks associated with plant phenanthrene contamination based on observations of decreased concentration, accumulation, and translocation factors of phenanthrene in ryegrass. Our results will have important ramifications in the assessment of the environmental risks of PAHs and in finding ways to circumvent plant PAH contamination.

  5. Deciphering the genetic determinants for aerobic nicotinic acid degradation: the nic cluster from Pseudomonas putida KT2440.

    Science.gov (United States)

    Jiménez, José I; Canales, Angeles; Jiménez-Barbero, Jesús; Ginalski, Krzysztof; Rychlewski, Leszek; García, José L; Díaz, Eduardo

    2008-08-12

    The aerobic catabolism of nicotinic acid (NA) is considered a model system for degradation of N-heterocyclic aromatic compounds, some of which are major environmental pollutants; however, the complete set of genes as well as the structural-functional relationships of most of the enzymes involved in this process are still unknown. We have characterized a gene cluster (nic genes) from Pseudomonas putida KT2440 responsible for the aerobic NA degradation in this bacterium and when expressed in heterologous hosts. The biochemistry of the NA degradation through the formation of 2,5-dihydroxypyridine and maleamic acid has been revisited, and some gene products become the prototype of new types of enzymes with unprecedented molecular architectures. Thus, the initial hydroxylation of NA is catalyzed by a two-component hydroxylase (NicAB) that constitutes the first member of the xanthine dehydrogenase family whose electron transport chain to molecular oxygen includes a cytochrome c domain. The Fe(2+)-dependent dioxygenase (NicX) converts 2,5-dihydroxypyridine into N-formylmaleamic acid, and it becomes the founding member of a new family of extradiol ring-cleavage dioxygenases. Further conversion of N-formylmaleamic acid to formic and maleamic acid is catalyzed by the NicD protein, the only deformylase described so far whose catalytic triad is similar to that of some members of the alpha/beta-hydrolase fold superfamily. This work allows exploration of the existence of orthologous gene clusters in saprophytic bacteria and some pathogens, where they might stimulate studies on their role in virulence, and it provides a framework to develop new biotechnological processes for detoxification/biotransformation of N-heterocyclic aromatic compounds.

  6. Plasmid dependence of Pseudomonas sp. strain NK87 enzymes that degrade 6-aminohexanoate-cyclic dimer.

    Science.gov (United States)

    Kanagawa, K; Negoro, S; Takada, N; Okada, H

    1989-06-01

    A bacterial strain, Pseudomonas sp. strain NK87, that can use 6-aminohexanoate-cyclic dimer as the sole source of carbon and nitrogen was newly isolated from wastewater of a factory which produces nylon-6. Two responsible enzymes, 6-aminohexanoate-cyclic-dimer hydrolase (P-EI) and 6-aminohexanoate-dimer hydrolase (P-EII), were found in the NK87 strain, as is the case with Flavobacterium sp. strain KI72, another 6-aminohexanoate-cyclic-dimer-metabolizing bacterium (H. Okada, S. Negoro, H. Kimura, and S. Nakamura, Nature [London] 306:203-206, 1983). The P-EI enzyme is immunologically identical to the 6-aminohexanoate-cyclic-dimer hydrolase of KI72 (F-EI). However, antiserum against the 6-aminohexanoate-dimer hydrolase purified from KI72 (F-EII) did not react with cell extracts of NK87, indicating that the F-EII and P-EII enzymes are immunologically different. Restriction endonuclease analyses show that the NK87 strain harbors at least six plasmids ranging in size from 20 to 80 kilobase pairs (kbp). The P-EI and P-EII genes were cloned in Escherichia coli. Both the P-EI and F-EI probes strongly hybridized with a 23-kbp plasmid in Southern hybridization analyses. The P-EII probe hybridized specifically with an 80-kbp plasmid, but the F-EII probe hybridized with none of the plasmids harbored in NK87. These results indicate that the P-EI gene and P-EII gene are encoded on the 23-kbp and 80-kbp plasmids, respectively.

  7. Functional analyses of three acyl-CoA synthetases involved in bile acid degradation in Pseudomonas putida DOC21.

    Science.gov (United States)

    Barrientos, Álvaro; Merino, Estefanía; Casabon, Israël; Rodríguez, Joaquín; Crowe, Adam M; Holert, Johannes; Philipp, Bodo; Eltis, Lindsay D; Olivera, Elías R; Luengo, José M

    2015-01-01

    Pseudomonas putida DOC21, a soil-dwelling proteobacterium, catabolizes a variety of steroids and bile acids. Transposon mutagenesis and bioinformatics analyses identified four clusters of steroid degradation (std) genes encoding a single catabolic pathway. The latter includes three predicted acyl-CoA synthetases encoded by stdA1, stdA2 and stdA3 respectively. The ΔstdA1 and ΔstdA2 deletion mutants were unable to assimilate cholate or other bile acids but grew well on testosterone or 4-androstene-3,17-dione (AD). In contrast, a ΔstdA3 mutant grew poorly in media containing either testosterone or AD. When cells were grown with succinate in the presence of cholate, ΔstdA1 accumulated Δ(1/4) -3-ketocholate and Δ(1,4) -3-ketocholate, whereas ΔstdA2 only accumulated 7α,12α-dihydroxy-3-oxopregna-1,4-diene-20-carboxylate (DHOPDC). When incubated with testosterone or bile acids, ΔstdA3 accumulated 3aα-H-4α(3'propanoate)-7aβ-methylhexahydro-1,5-indanedione (HIP) or the corresponding hydroxylated derivative. Biochemical analyses revealed that StdA1 converted cholate, 3-ketocholate, Δ(1/4) -3-ketocholate, and Δ(1,4) -3-ketocholate to their CoA thioesters, while StdA2 transformed DHOPDC to DHOPDC-CoA. In contrast, purified StdA3 catalysed the CoA thioesterification of HIP and its hydroxylated derivatives. Overall, StdA1, StdA2 and StdA3 are acyl-CoA synthetases required for the complete degradation of bile acids: StdA1 and StdA2 are involved in degrading the C-17 acyl chain, whereas StdA3 initiates degradation of the last two steroid rings. The study highlights differences in steroid catabolism between Proteobacteria and Actinobacteria.

  8. Complete Genome Sequences of Pseudomonas monteilii SB3078 and SB3101, Two Benzene-, Toluene-, and Ethylbenzene-Degrading Bacteria Used for Bioaugmentation

    DEFF Research Database (Denmark)

    Dueholm, Morten Simonsen; Albertsen, Mads; D'Imperio, Seth;

    2014-01-01

    Pseudomonas monteilii SB3078 and SB3101 are benzene-, toluene-, and ethylbenzene-degrading strains used for bioaugmentation in relation to treatment of wastewater contaminated with petrochemical hydrocarbons. Complete genome sequencing of the bioaugmentation strains confirms that they are very...... closely related (100.0% average nucleotide identity). Both strains contain extensive integration of phage elements, with the main difference being insertion of additional phage elements in the SB3078 genome....

  9. Optimisation for enhanced decolourization and degradation of Reactive Red BS C.I. 111 by Pseudomonas aeruginosa NGKCTS.

    Science.gov (United States)

    Sheth, N T; Dave, S R

    2009-11-01

    Soil samples collected from dye contaminated sites of Vatva, Gujarat, India were studied for the screening and isolation of organisms capable of decolourizing textile dyes. The most efficient isolate, which showed decolourization zone of 48 mm on 300 ppm Reactive Red BS (C.I.111) containing plate, was identified as Pseudomonas aeruginosa. Reactive Red BS (C.I.111) was used as a model dye for the study. The isolated culture exhibited 91% decolourization of 300 ppm dye within 5.5 h over a wide pH range from 5.0 to 10.5 and temperature ranging from 30 to 40 degrees C. The culture was able to decolourize more than 91% of Reactive Red BS under static conditions in presence of either glucose, peptone or yeast extract. Addition of 300 ppm of Reactive Red BS, in each step, in ongoing dye decolourization flask, gave more than 90% decolourization within 2 h corresponding to 136 mg l(-1) h(-1) dye removal rate. The isolate had the ability to decolourize six different reactive dyes tested as well as the actual dye manufacturing industry's effluent. The degradation of the dye was confirmed by HPTLC.

  10. Biodegradation of malachite green by Pseudomonas sp. strain DY1 under aerobic condition: characteristics, degradation products, enzyme analysis and phytotoxicity.

    Science.gov (United States)

    Du, Lin-Na; Wang, Sheng; Li, Gang; Wang, Bing; Jia, Xiao-Ming; Zhao, Yu-Hua; Chen, Yun-Long

    2011-03-01

    Malachite green (MG), a widely-used and recalcitrant dye, has been confirmed to be carcinogenic and mutagenic against many organisms. The main objective of this study is to investigate the capability of Pseudomonas sp. strain DY1 to decolorize MG, and to explore the possible mechanism. The results showed that this strain demonstrated high decolorizing capability (90.3-97.2%) at high concentrations of MG (100-1,000 mg/l) under shaking condition within 24 h. In static conditions, lower but still effective decolorization (78.9-84.3%) was achieved. The optimal pH and temperature for the decolorization was pH 6.6 and 28-30°C, respectively. Mg(2+) and Mn(2+) (1 mM) were observed to significantly enhance the decolorization. The intermediates of the MG degradation under aerobic condition identified by UV-visible, GC-MS and LC-MS analysis included malachite green carbinol, (dimethyl amino-phenyl)-phenyl-methanone, N,N-dimethylaniline, (methyl amino-phenyl)-phenyl-methanone, (amino phenyl)-phenyl methanone and di-benzyl methane. The enzyme analysis indicated that Mn-peroxidase, NADH-DCIP and MG reductase were involved in the biodegradation of MG. Moreover, phytotoxicity of MG and detoxification for MG by the strain were observed. Therefore, this strain could be potentially used for bioremediation of MG.

  11. Cytotoxic effect of chlorpyrifos ethyl and its degradation derivatives by Pseudomonas peli strain isolated from the Oued Hamdoun River (Tunisia).

    Science.gov (United States)

    Dellai, Afef; Dridi, Dorra; Sakouhi, Seif; Robert, Jacques; Djelal, Hayet; Mosrati, Ridha; Cherif, Ameur; Mansour, Hedi Ben

    2016-04-01

    A bacterium was isolated from the river of Oued Hamdoun (Tunisia), and its phenotypic features, physiological and chemotaxonomic characteristics and phylogenetic analysis of 16S ribosomal RNA sequence revealed it as Pseudomonas peli (P. peli). Chlorpyrifos ethyl (CP) was used as the sole source of carbon and energy by P. peli, and it was cometabolised in the presence of glucose. CP was completely degraded by P. peli after 96 h of shake incubation. High-performance liquid chromatography analysis indicated that the biodegradation kinetics was not affected by the addition of glucose into the culture medium. In the present study, only transient accumulation of one major no-identified product was observed after 48 h of incubation, with no other persistent metabolites detected. Cytotoxicity of CP, before and after biodegradation with P. peli, was evaluated in vitro using the MTT-colorimetric assay against three human cancer cell lines (A549, lung cell carcinoma, HT29, colon adenocarcinoma and MCF7, breast adenocarcinoma). CP reduced viability of all human cell lines in a dose-dependent manner. Its activity was very remarkable against A549 cell line. However, cytotoxicity strongly decreased in CP obtained after incubation with P. peli Hence, we conclude that when incubated under appropriate conditions,P. peli has a metabolism that completely detoxifies CP.

  12. Pseudomonas stutzeri strain possessing a self-transmissible TOL-like plasmid degrades phenol and promotes maize growth in contaminated environments.

    Science.gov (United States)

    Jiang, Qiuyue; Zhou, Chenhao; Wang, Yujing; Si, Fangyi; Zhou, Yanjun; Chen, Bing; Zhao, Yu; Chen, Jun; Xiao, Ming

    2014-04-01

    Phenol is volatile organic pollutant that plants can little degrade. For complete degradation of volatile pollutants, we introduced Pseudomonas stutzeri strain P7 to phenol-contaminated soils. The strain effectively degraded phenol and even promoted plant growth. A TOL-like plasmid was detected in the strain and found to be responsible for phenol degradation and self-transmissible. In addition, phenol degradation by strain P7 was more rapid in the contaminated soils with than without plants over the full course of the experiment; especially by 5 days, the phenol concentration was reduced by about 30 % in soil without plants and reduced by about 50-65 % in soil with plants. This situation also occurred when inoculated with different transconjugants. Furthermore, transfer frequencies of TOL-like plasmid were significantly higher in soil with than without plants. Populations of rifampin-resistant P7 strain remained relatively constant for 20 days, while the number of rhizosphere bacteria that contained the degradative plasmids gradually increased at the later stages, suggesting that plants might stimulate plasmid transfer from strain P7 to indigenous bacteria, one possible reason for plant enhancing microbial degradation. This is attractive for implementation of combinations of phytoremediation and bioaugmentation in degradation of volatile pollutants that plants can little degrade.

  13. Determining design and scale-up parameters for degradation of atrazine with suspended Pseudomonas sp. ADP in aqueous bioreactors.

    Science.gov (United States)

    Biglione, Nicole; Rodgers, V G J; Peeples, Tonya L

    2008-01-01

    This work investigated the kinetic parameters of atrazine mineralization by suspended cells of Pseudomonas sp. ADP in both shake flasks and spherical stirred tank batch reactors (SSTR). The degradation of atrazine and growth of Pseudomonas sp. ADP were studied. Experiments were performed at different temperatures and stirring speeds in both reactors at varying initial concentrations of atrazine. Cell growth and atrazine concentration were monitored over time, and a Monod model with one limiting substrate was used to characterize the kinetic behavior. Temperature, stirring speed, and reactor type were all found to significantly affect the regressed Monod parameters. At 27 degrees C and 200 rpm, for the shaker flask experiments, mu max and Ks were determined to be 0.14 (+/-0.01) h-1 and 1.88 (+/-1.80) mg/L, respectively. At 37 degrees C, mu max and Ks increased to 0.25 (+/-0.05) h-1 and 9.59 (+/-6.55) mg/L, respectively. As expected, stirrer speed was also found to significantly alter the kinetic parameters. At 27 degrees C and 125 rpm, mu max and Ks were 0.04 (+/-0.002) h-1 and 3.72 (+/-1.05) mg/L, respectively, whereas at 37 degrees C and 125 rpm, mu max and Ks were 0.07 (+/-0.008) h-1 and 1.65 (+/-2.06) mg/L. In the SSTR the kinetic parameters mu max and Ks at room temperature were determined to be 0.12 (+/-0.009) h-1 and 2.18 (+/-0.47) mg/L, respectively. Although the mu max values for both types of reactors were similar, the shaker flask experiments resulted in considerable error. Error analysis on calculated values of Ks were found to impact estimates in atrazine concentration by as much as two orders of magnitude, depending on the reactor design, illustrating the importance of these factors in reactor scale-up.

  14. Selection of Pseudomonas sp. strain HBP1 Prp for metabolism of 2-propylphenol and elucidation of the degradative pathway

    NARCIS (Netherlands)

    Kohler, Hans-Peter E.; Maarel, Marc J.E.C. van der; Kohler-Staub, Doris

    1993-01-01

    A mutant of Pseudomonas sp. strain HBP1, originally isolated on 2-hydroxybiphenyl, was selected for the ability to grow on 2-propylphenol as the sole carbon and energy source. In the mutant strain, which was designated as Pseudomonas sp. strain HBP1 Prp, the cellular induction mechanism involved in

  15. Analysis of Diversity of Pyridine Degradation by Three Pseudomonas sp.%三株Pseudomonas sp.的吡啶降解多样性分析

    Institute of Scientific and Technical Information of China (English)

    易霞; 韦良焕

    2011-01-01

    目的:为了探讨3株Pseudomonas sp.对吡啶降解存在多样性.方法:基于16S rRNA和ISR序列分析,对3株分离菌株进行初步鉴定,进而通过Touch -Down PCR,对3株细菌降解吡啶的多样性进行分析.结果:3株细菌XJUHX -1、XJUHX - 12和XJUHX - 16初步鉴定为Pseudomonas,3株实验菌株的部分降解基因的扩增条带有差异.结论:同属的3株 Pseudomonas在吡啶降解上存在多样性.

  16. A sirA-like gene, sirA2, is essential for 3-succinoyl-pyridine metabolism in the newly isolated nicotine-degrading Pseudomonas sp. HZN6 strain.

    Science.gov (United States)

    Qiu, Jiguo; Ma, Yun; Chen, Liansheng; Wu, Lifei; Wen, Yuezhong; Liu, Weiping

    2011-12-01

    A novel nicotine-degrading Pseudomonas sp. strain, HZN6, was isolated from a pesticide-wastewater treatment facility in Hangzhou. The strain could grow on nicotine as its sole source of carbon, nitrogen, and energy. The strain's main intermediate metabolites were determined to be pseudooxynicotine, 3-succinoyl-pyridine (SP), and 6-hydroxy-3-succinoyl-pyridine (HSP). A Tn5 transposon mutant was generated in which the degradation pathway was blocked at the SP. A 4,583-bp DNA fragment flanking the transposon insertion site was obtained through self-formed adaptor PCR and analyzed. The mutant gene orfC displays 89% deduced amino acid sequence identity with the sirA-like gene (sirA2, a sulfurtransferase homologue gene) of Pseudomonas stutzeri A1501. The orfC-disrupted strain lost the ability to degrade SP, and the complementation strains with the orfC from the Pseudomonas sp. HZN6 and the sirA2 (PP_1233) from Pseudomonas putida KT2440 recovered the degradation ability. Though the orfC-disrupted strain also lost the xanthine dehydrogenase activity, the effects of tungsten on the degradation of SP and hypoxanthine revealed that the hydroxylation of SP to HSP was not a xanthine dehydrogenase type. These results demonstrated that the orfC gene was essential for the SP metabolism involved in the nicotine metabolic pathway in the Pseudomonas sp. HZN6 strain. This study might advance the understanding of the nicotine metabolic mechanism in Pseudomonas.

  17. Transcriptional activation of multiple operons involved in para-nitrophenol degradation by Pseudomonas sp. Strain WBC-3.

    Science.gov (United States)

    Zhang, Wen-Mao; Zhang, Jun-Jie; Jiang, Xuan; Chao, Hongjun; Zhou, Ning-Yi

    2015-01-01

    Pseudomonas sp. strain WBC-3 utilizes para-nitrophenol (PNP) as a sole carbon and energy source. The genes involved in PNP degradation are organized in the following three operons: pnpA, pnpB, and pnpCDEFG. How the expression of the genes is regulated is unknown. In this study, an LysR-type transcriptional regulator (LTTR) is identified to activate the expression of the genes in response to the specific inducer PNP. While the LTTR coding gene pnpR was found to be not physically linked to any of the three catabolic operons, it was shown to be essential for the growth of strain WBC-3 on PNP. Furthermore, PnpR positively regulated its own expression, which is different from the function of classical LTTRs. A regulatory binding site (RBS) with a 17-bp imperfect palindromic sequence (GTT-N11-AAC) was identified in all pnpA, pnpB, pnpC, and pnpR promoters. Through electrophoretic mobility shift assays and mutagenic analyses, this motif was proven to be necessary for PnpR binding. This consensus motif is centered at positions approximately -55 bp relative to the four transcriptional start sites (TSSs). RBS integrity was required for both high-affinity PnpR binding and transcriptional activation of pnpA, pnpB, and pnpR. However, this integrity was essential only for high-affinity PnpR binding to the promoter of pnpCDEFG and not for its activation. Intriguingly, unlike other LTTRs studied, no changes in lengths of the PnpR binding regions of the pnpA and pnpB promoters were observed after the addition of the inducer PNP in DNase I footprinting.

  18. Degradation of 2,4-dinitroanisole (DNAN) by metabolic cooperative activity of Pseudomonas sp. strain FK357and Rhodococcus imtechensis strain RKJ300.

    Science.gov (United States)

    Khan, Fazlurrahman; Pal, Deepika; Ghosh, Anuradha; Cameotra, Swaranjit Singh

    2013-11-01

    2,4-Dinitroanisole (DNAN) is an insensitive explosive ingredient used by many defense agencies as a replacement for 2,4,6-trinitrotoluene. Although the biotransformation of DNAN under anaerobic condition has been reported, aerobic microbial degradation pathway has not been elucidated. An n-methyl-4-nitroaniline degrading bacterium Pseudomonas sp. strain FK357 transformed DNAN into 2,4-dinitrophenol (2,4-DNP) as an end product. Interestingly, when strain FK357 was co-cultured with a 2,4-DNP degrading Rhodococcus imtechensis strain RKJ300, complete and high rate of DNAN degradation was observed with no accumulation of intermediates. Enzyme assay using cell extracts of strain FK357 demonstrated that O-demethylation reaction is the first step of DNAN degradation with formation of 2,4-DNP and formaldehyde as intermediates. Subsequently, 2,4-DNP was degraded by strain RKJ300 via the formation of hydride-Meisenheimer complex. The present study clearly demonstrates that complete degradation of DNAN occurs as a result of the metabolic cooperative activity of two members within a bacterial consortium.

  19. Biosynthesis of indigo dye by newly isolated naphthalene-degrading strain Pseudomonas sp. HOB1 and its application in dyeing cotton fabric.

    Science.gov (United States)

    Pathak, Hilor; Madamwar, Datta

    2010-03-01

    Indigo is one of the oldest dyes manufactured chemically and is mostly used in textile, food, and pharmaceutical industries. However, owing to the environmental hazards posed by the chemical production, the present scenario in the field stipulates a biosynthesis alternative for indigo production. The present study describes an indigenously isolated naphthalene-degrading strain Pseudomonas sp. HOB1 producing a blue pigment when indole was added in the growth medium. This blue pigment was analyzed by high-pressure thin-layer chromatography and other spectroscopic techniques which revealed it to be the indigo dye. Pseudomonas sp. HOB1 showed ability to produce 246 mg indigo liter(-1) of the medium. The K (m) for the enzyme naphthalene dioxygenase which is involved in indigo formation is 0.3 mM, and V (max) was as high as 50 nmol min(-1) mg dry biomass(-1). The bacterial indigo dye was further successfully applied for dyeing cotton fabrics. The high indigo productivity of Pseudomonas sp. HOB1 using naphthalene as growth substrate and its applicability on cotton fabrics, therefore, stems the probability of using this culture for commercial indigo production.

  20. An in vitro Assessment on the Efficacy of Clay-Based Formulated Cells of Pseudomonas Isolate UTAR EPA2 for Petrol Degradation

    Directory of Open Access Journals (Sweden)

    A. S.Y. Ting

    2010-01-01

    Full Text Available Problem statement: Application of free-cell forms is usually impractical to achieve satisfactory bioremediative effect because the microbes are encumbered by the biotic and abiotic stresses from the environment. Approach: In this study, a hydrocarbon-degrading bacterium (Pseudomonas isolate UTAR EPA2 was formulated with various combinations of formulative materials, comprising of clay-based carrier materials such as Bentonite (B and Kaolin (K, enrichment materials such as Non-fat skimmed milk (N and Sucrose (S and a UV-protectant agent Para-aminobenzoic acid (P. Formulated cells were treated to sunlight exposure for 6 h to mimic the conditions in the environment prior to testing for their efficacy in degrading petrol, a mixed hydrocarbon substrate. Results: Cells in all formulations including free-cell suspension were able to degrade petrol with a relatively high degradation efficacy of more than 66% even after exposure to sunlight. Degradation efficacy was slightly higher for kaolin-based formulated cells compared to bentonite-based formulations, especially after exposure to sunlight, although their percentages of degradation were not statistically different. Nevertheless, kaolin-based formulations have very low viable cell count especially in formulations with P (KP, KNP, KSP, KNSP. This suggested that aside from viable cells, the physical properties of the clays could have also contributed to the degradation of petrol. Conclusion: For storage purposes and applications in the field, we suggest that the bacterium is formulated with bentonite-based formulations especially using Bentonite (B clay singly, as relatively high percentage of petrol degradation and viable cell count was achieved with this formulation.

  1. Characterization of hydrocarbon-degrading and biosurfactant-producing Pseudomonas sp. P-1 strain as a potential tool for bioremediation of petroleum-contaminated soil.

    Science.gov (United States)

    Pacwa-Płociniczak, Magdalena; Płaza, Grażyna Anna; Poliwoda, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    The Pseudomonas sp. P-1 strain, isolated from heavily petroleum hydrocarbon-contaminated soil, was investigated for its capability to degrade hydrocarbons and produce a biosurfactant. The strain degraded crude oil, fractions A5 and P3 of crude oil, and hexadecane (27, 39, 27 and 13% of hydrocarbons added to culture medium were degraded, respectively) but had no ability to degrade phenanthrene. Additionally, the presence of gene-encoding enzymes responsible for the degradation of alkanes and naphthalene in the genome of the P-1 strain was reported. Positive results of blood agar and methylene blue agar tests, as well as the presence of gene rhl, involved in the biosynthesis of rhamnolipid, confirmed the ability of P-1 for synthesis of glycolipid biosurfactant. 1H and 13C nuclear magnetic resonance, Fourier transform infrared spectrum and mass spectrum analyses indicated that the extracted biosurfactant was affiliated with rhamnolipid. The results of this study indicate that the P-1 and/or biosurfactant produced by this strain have the potential to be used in bioremediation of hydrocarbon-contaminated soils.

  2. Draft genome sequence of the polycyclic aromatic hydrocarbon-degrading, genetically engineered bioluminescent bioreporter Pseudomonas fluorescens HK44.

    Science.gov (United States)

    Chauhan, Archana; Layton, Alice C; Williams, Daniel E; Smartt, Abby E; Ripp, Steven; Karpinets, Tatiana V; Brown, Steven D; Sayler, Gary S

    2011-09-01

    Pseudomonas fluorescens strain HK44 (DSM 6700) is a genetically engineered lux-based bioluminescent bioreporter. Here we report the draft genome sequence of strain HK44. Annotation of ∼6.1 Mb of sequence indicates that 30% of the traits are unique and distributed over five genomic islands, a prophage, and two plasmids.

  3. Draft Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading, Genetically Engineered Bioluminescent Bioreporter Pseudomonas fluorescens HK44 ▿

    Science.gov (United States)

    Chauhan, Archana; Layton, Alice C.; Williams, Daniel E.; Smartt, Abby E.; Ripp, Steven; Karpinets, Tatiana V.; Brown, Steven D.; Sayler, Gary S.

    2011-01-01

    Pseudomonas fluorescens strain HK44 (DSM 6700) is a genetically engineered lux-based bioluminescent bioreporter. Here we report the draft genome sequence of strain HK44. Annotation of ∼6.1 Mb of sequence indicates that 30% of the traits are unique and distributed over five genomic islands, a prophage, and two plasmids. PMID:21742869

  4. Draft Genome Sequence of the Polycyclic Aromatic Hydrocarbon-Degrading, Genetically Engineered Bioluminescent Bioreporter Pseudomonas fluorescens HK44

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Archana [ORNL; Layton, Alice [University of Tennessee, Knoxville (UTK); Williams, Daniel W [ORNL; Smart, Abby E. [University of Tennessee, Knoxville (UTK); Ripp, Steven Anthony [ORNL; Karpinets, Tatiana V [ORNL; Brown, Steven D [ORNL; Sayler, Gary Steven [ORNL

    2011-01-01

    Pseudomonas fluorescens strain HK44 (DSM 6700) is a genetically engineered lux-based bioluminescent bioreporter. Here we report the draft genome sequence of strain HK44. Annotation of {approx}6.1 Mb sequence indicates that 30% of the traits are unique and distributed over 5 genomic islands, a prophage and two plasmids.

  5. Characterization of the medium- and long-chain n-alkanes degrading Pseudomonas aeruginosa strain SJTD-1 and its alkane hydroxylase genes.

    Science.gov (United States)

    Liu, Huan; Xu, Jing; Liang, Rubing; Liu, Jianhua

    2014-01-01

    A gram-negative aliphatic hydrocarbon-degrading bacterium SJTD-1 isolated from oil-contaminated soil was identified as Pseudomonas aeruginosa by comparative analyses of the 16S rRNA sequence, phenotype, and physiological features. SJTD-1 could efficiently mineralize medium- and long-chain n-alkanes (C12-C30) as its sole carbon source within seven days, showing the most optimal growth on n-hexadecane, followed by n-octadecane, and n-eicosane. In 36 h, 500 mg/L of tetradecane, hexadecane, and octadecane were transformed completely; and 2 g/L n-hexadecane was degraded to undetectable levels within 72 h. Two putative alkane-degrading genes (gene 3623 and gene 4712) were characterized and our results indicated that their gene products were rate-limiting enzymes involved in the synergetic catabolism of C12-C16 alkanes. On the basis of bioinformatics and transcriptional analysis, two P450 monooxygenases, along with a putative AlmA-like oxygenase, were examined. Genetically defective mutants lacking the characteristic alkane hydroxylase failed to degrade n-octadecane, thereby suggesting a different catalytic mechanism for the microbial transformation of alkanes with chain lengths over C18.

  6. iTRAQ-based quantitative proteomic analysis of the global response to 17β-estradiol in estrogen-degradation strain Pseudomonas putida SJTE-1

    Science.gov (United States)

    Xu, Jing; Zhang, Lei; Hou, Jingli; Wang, Xiuli; Liu, Huan; Zheng, Daning; Liang, Rubing

    2017-01-01

    Microorganism degradation is efficient to remove the steroid hormones like 17β-estradiol (E2); but their degradation mechanism and metabolic network to these chemicals are still not very clear. Here the global responses of the estrogen-degradation strain Pseudomonas putida SJTE-1 to 17β-estradiol and glucose were analyzed and compared using the iTRAQ (isobaric tags for relative and absolute quantization) strategy combined with LC-MS/MS (liquid chromatography-tandem mass spectrometry). 78 proteins were identified with significant changes in expression; 45 proteins and 33 proteins were up-regulated and down-regulated, respectively. These proteins were mainly involved in the processes of stress response, energy metabolism, transportation, chemotaxis and cell motility, and carbon metabolism, considered probably responding to 17β-estradiol and playing a role in its metabolism. The up-regulated proteins in electron transfer, energy generation and transport systems were thought crucial for efficient uptake, translocation and transformation of 17β-estradiol. The over-expression of carbon metabolism proteins indicated cells may activate related pathway members to utilize 17β-estradiol. Meanwhile, proteins functioning in glucose capture and metabolism were mostly down-regulated. These findings provide important clues to reveal the 17β-estradiol degradation mechanism in P. putida and promote its bioremediation applications. PMID:28155874

  7. Pseudomonas aeruginosa Cif protein enhances the ubiquitination and proteasomal degradation of the transporter associated with antigen processing (TAP) and reduces major histocompatibility complex (MHC) class I antigen presentation.

    Science.gov (United States)

    Bomberger, Jennifer M; Ely, Kenneth H; Bangia, Naveen; Ye, Siying; Green, Kathy A; Green, William R; Enelow, Richard I; Stanton, Bruce A

    2014-01-03

    Cif (PA2934), a bacterial virulence factor secreted in outer membrane vesicles by Pseudomonas aeruginosa, increases the ubiquitination and lysosomal degradation of some, but not all, plasma membrane ATP-binding cassette transporters (ABC), including the cystic fibrosis transmembrane conductance regulator and P-glycoprotein. The goal of this study was to determine whether Cif enhances the ubiquitination and degradation of the transporter associated with antigen processing (TAP1 and TAP2), members of the ABC transporter family that play an essential role in antigen presentation and intracellular pathogen clearance. Cif selectively increased the amount of ubiquitinated TAP1 and increased its degradation in the proteasome of human airway epithelial cells. This effect of Cif was mediated by reducing USP10 deubiquitinating activity, resulting in increased polyubiquitination and proteasomal degradation of TAP1. The reduction in TAP1 abundance decreased peptide antigen translocation into the endoplasmic reticulum, an effect that resulted in reduced antigen available to MHC class I molecules for presentation at the plasma membrane of airway epithelial cells and recognition by CD8(+) T cells. Cif is the first bacterial factor identified that inhibits TAP function and MHC class I antigen presentation.

  8. A Direct Quantitative Agar-Plate Based Assay for Analysis of Pseudomonas protegens PF-5 Degradation of Polyurethane Films (Postprint)

    Science.gov (United States)

    2014-10-02

    Interactions between the Pf-5 colonies and thin polyurethane (PU) coatings on ZnSe coupons were evaluated for degradation using infrared spectroscopy...the Pf-5 col- onies and thin polyurethane (PU) coatings on ZnSe coupons were evaluated for degradation using infrared spectroscopy. Three different...transmission micro-Fourier transform infrared (mFT-IR) analysis to sensitively and quantitatively assess degradation of PU polymers using bacterial colonies ឈ

  9. The genes coding for the conversion of carbazole to catechol are flanked by IS6100 elements in Sphingomonas sp. strain XLDN2-5.

    Directory of Open Access Journals (Sweden)

    Zhonghui Gai

    Full Text Available BACKGROUND: Carbazole is a recalcitrant compound with a dioxin-like structure and possesses mutagenic and toxic activities. Bacteria respond to a xenobiotic by recruiting exogenous genes to establish a pathway to degrade the xenobiotic, which is necessary for their adaptation and survival. Usually, this process is mediated by mobile genetic elements such as plasmids, transposons, and insertion sequences. FINDINGS: The genes encoding the enzymes responsible for the degradation of carbazole to catechol via anthranilate were cloned, sequenced, and characterized from a carbazole-degrading Sphingomonas sp. strain XLDN2-5. The car gene cluster (carRAaBaBbCAc and fdr gene were accompanied on both sides by two copies of IS6100 elements, and organized as IS6100::ISSsp1-ORF1-carRAaBaBbCAc-ORF8-IS6100-fdr-IS6100. Carbazole was converted by carbazole 1,9a-dioxygenase (CARDO, CarAaAcFdr, meta-cleavage enzyme (CarBaBb, and hydrolase (CarC to anthranilate and 2-hydroxypenta-2,4-dienoate. The fdr gene encoded a novel ferredoxin reductase whose absence resulted in lower transformation activity of carbazole by CarAa and CarAc. The ant gene cluster (antRAcAdAbAa which was involved in the conversion of anthranilate to catechol was also sandwiched between two IS6100 elements as IS6100-antRAcAdAbAa-IS6100. Anthranilate 1,2-dioxygenase (ANTDO was composed of a reductase (AntAa, a ferredoxin (AntAb, and a two-subunit terminal oxygenase (AntAcAd. Reverse transcription-PCR results suggested that carAaBaBbCAc gene cluster, fdr, and antRAcAdAbAa gene cluster were induced when strain XLDN2-5 was exposed to carbazole. Expression of both CARDO and ANTDO in Escherichia coli required the presence of the natural reductases for full enzymatic activity. CONCLUSIONS/SIGNIFICANCE: We predict that IS6100 might play an important role in the establishment of carbazole-degrading pathway, which endows the host to adapt to novel compounds in the environment. The organization of the car

  10. Potential of the TCE-degrading endophyte Pseudomonas putida W619-TCE to improve plant growth and reduce TCE phytotoxicity and evapotranspiration in poplar cuttings

    Energy Technology Data Exchange (ETDEWEB)

    Weyens, N.; van der Lelie, D.; Truyens, S.; Dupae, J.; Newman, L.; Taghavi, S.; Carleer, R.; Vangronsveld, J.

    2010-09-01

    The TCE-degrading poplar endophyte Pseudomonas putida W619-TCE was inoculated in poplar cuttings, exposed to 0, 200 and 400 mg l{sup -1} TCE, that were grown in two different experimental setups. During a short-term experiment, plants were grown hydroponically in half strength Hoagland nutrient solution and exposed to TCE for 3 days. Inoculation with P. putida W619-TCE promoted plant growth, reduced TCE phytotoxicity and reduced the amount of TCE present in the leaves. During a mid-term experiment, plants were grown in potting soil and exposed to TCE for 3 weeks. Here, inoculation with P. putida W619-TCE had a less pronounced positive effect on plant growth and TCE phytotoxicity, but resulted in strongly reduced amounts of TCE in leaves and roots of plants exposed to 400 mg l{sup -1} TCE, accompanied by a lowered evapotranspiration of TCE. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), which are known intermediates of TCE degradation, were not detected. The endophyte P. putida W619-TCE degrades TCE during its transport through the xylem, leading to reduced TCE concentrations in poplar, and decreased TCE evapotranspiration.

  11. Isolation and characterization of a novel paraffin wax-degrading bacterium, Pseudomonas sp strain PW-1, from petroleum-contaminated sites.

    Science.gov (United States)

    Zhang, Y L; Liu, Z; Liu, T

    2016-06-10

    An isolate capable of degrading paraffin wax was isolated from petroleum-contaminated sites in Daqing, China, and identified as Pseudomonas sp strain PW-1 by analyzing the 16S rDNA sequence (GenBank accession No.: KF529529) as well as the biochemical and physiological characteristics. The optimized degradation conditions of the isolate were as follows: FeSO4 metal ion concentration of 0.01 g, temperature of 30°C, (NH4)2SO4 nitrogen source concentration of 1.5 g/L, and a carbon: nitrogen ratio of 10:1. Response surface methodology-based analysis of the culture time, inoculation amount, and initial pH of the medium revealed that the optimal theoretical conditions were a culture time of 11.16 days, inoculation amount of 3.13%, and an initial pH of 9.29. The theoretical degradation rate was up to 54.68% under the optimal conditions. Taking into account the experimental conditions of a laboratory, 11.2 days of cultivating time, 3% inoculum, and a medium initial pH of 9.3 were used in practical settings. Experimental results showed that the degradation rate of paraffin wax was 52.85%, which demonstrated that this strain could degrade 1050 mg paraffin wax, using it as the sole carbon source, in a 1000-mL minimal salts medium. These results indicate that the strain PW1 can be used for application in oil wells with paraffin deposition problems in order to enhance oil recovery.

  12. Comparative Kinetic Studies and Performance Evaluation of Biofilm and Biomass Characteristics of Pseudomonas fluorescens in Degrading Synthetic Phenolic Effluent in Inverse Fluidized Bed Biofilm Reactor.

    Science.gov (United States)

    Begum, S Sabarunisha; Radha, K V

    2016-05-01

    The bioremediation potential of Pseudomonas fluorescens was studied in an Inverse Fluidized Bed Biofilm Reactor under batch recirculation conditions using synthetic phenolic effluent of various concentrations (400, 600, 800, 1000 and 1200 mg/l). The performance of the reactor was investigated and the characteristics of biomass and biofilm were determined by evaluating biofilm dry density and thickness, bioparticle density, suspended and attached biomass concentration, chemical oxygen demand and phenol removal efficiency. Biodegradation kinetics had been studied for suspended biomass culture and biofilm systems with respect to its specific growth and substrate consumption rates. Suspended biomass followed substrate inhibition kinetics and the experimental data fitted well with the Haldane model. The degradation kinetic behavior of biofilm revealed that a well adapted biofilm system with effective control of biofilm thickness in an inverse fluidized bed biofilm reactor overcomes substrate inhibition effects by tolerating higher phenol concentration and fitted well to the Monod model.

  13. Pyrroloquinoline Quinone-Dependent Cytochrome Reduction in Polyvinyl Alcohol-Degrading Pseudomonas sp. Strain VM15C

    OpenAIRE

    1989-01-01

    A polyvinyl alcohol (PVA) oxidase-deficient mutant of Pseudomonas sp. strain VM15C, strain ND1, was shown to possess PVA dehydrogenase, in which pyrroloquinoline quinone (PQQ) functions as a coenzyme. The mutant grew on PVA and required PQQ for utilization of PVA as an essential growth factor. Incubation of the membrane fraction of the mutant with PVA caused cytochrome reduction of the fraction. Furthermore, it was found that in spite of the presence of PVA oxidase, the membrane fraction of s...

  14. 75 FR 62765 - Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty Changed-Circumstances...

    Science.gov (United States)

    2010-10-13

    ... International Trade Administration Carbazole Violet Pigment 23 From India: Final Results of Antidumping Duty.... See Carbazole Violet Pigment 23 From India: Preliminary Results of Antidumping Duty Changed... most recently completed review. See Carbazole Violet Pigment 23 From India: Final Results...

  15. ISOLATION AND CHARACTERIZATION OF A MOLYBDENUM-REDUCING, PHENOL- AND CATECHOL-DEGRADING PSEUDOMONAS PUTIDA STRAIN AMR-12 IN SOILS FROM EGYPT

    Directory of Open Access Journals (Sweden)

    M. Abd. AbdEl-Mongy

    2016-02-01

    Full Text Available Sites contaminated with both heavy metals and organic xenobiotic pollutants warrants the effective use of either a multitude of bacterial degraders or bacteria having the capacity to detoxify numerous toxicants simultaneously. A molybdenum-reducing bacterium with the capacity to degrade phenolics is reported. Molybdenum (sodium molybdate reduction was optimum between pH 6.0 and 7.0 and between 20 and 30 °C. The most suitable electron donor was glucose. A narrow range of phosphate concentrations between 5.0 and 7.5 mM was required for optimal reduction, while molybdate between 20 and 30 mM were needed for optimal reduction. The scanning absorption spectrum of the molybdenum blue produced indicated that Mo-blue is a reduced phosphomolybdate. Molybdenum reduction was inhibited by the heavy metals mercury, silver and chromium. Biochemical analysis identified the bacterium as Pseudomonas putida strain Amr-12. Phenol and phenolics cannot support molybdenum reduction. However, the bacterium was able to grow on the phenolic compounds (phenol and catechol with observable lag periods. Maximum growth on phenol and catechol occurred around the concentrations of 600 mg∙L-1. The ability of this bacterium to detoxify molybdenum and grown on toxic phenolic makes this bacterium an important tool for bioremediation.

  16. Degradation of alpha-pinene oxide and [2H7]-2,5,6-trimethyl-hept-(2E)-enoic acid by Pseudomonas fluorescens NCIMB 11761.

    Science.gov (United States)

    Zorn, H; Neuser, F; Berger, R G

    2004-02-01

    When submerged cultured Pseudomonas fluorescens NCIMB 11761 was fed-batch supplemented with alpha-pinene oxide, a rapid formation of 2,6-dimethyl-5-methylene-hept-(2Z)-enal (I) (isonovalal) was observed. Biotransformation and isomerisation of (I) to the (2E)-isomer (II) (novalal) were enhanced by Lewatit OC 1064, a macroporous polystyrene adsorbent. Accelerated isomerisation in the presence of an amino donor (glycine) at pH 7.3 pointed to a merely chemical mechanism. A maximum yield of 48 g of aldehydesl(-1) was achieved, but quantitative analysis of the volatile fraction showed that the molar conversion of the pinene oxide substrate reached no more than 67%. To fill this gap of the mass balance, the acidic fraction was isolated. It contained several compounds which suggested a beta-oxidation-like catabolism starting from 2,6-dimethyl-5-methylene-hept-(2E)-enoic acid (III) (novalic acid). Using [2H7]-2,5,6-dimethyl-hept-(2E)-enoic acid as a conversion substrate and gas chromatography coupled to atomic emission detection and mass spectrometry a degradation pathway via labelled 3,4-dimethylpentenoic and methylpropanoic acids was evidenced. This pathway may play a predominant role in isoprenoid degradation by soil bacteria.

  17. Potential of the TCE-degrading endophyte Pseudomonas putida W619-TCE to improve plant growth and reduce TCE phytotoxicity and evapotranspiration in poplar cuttings.

    Science.gov (United States)

    Weyens, Nele; Truyens, Sascha; Dupae, Joke; Newman, Lee; Taghavi, Safiyh; van der Lelie, Daniel; Carleer, Robert; Vangronsveld, Jaco

    2010-09-01

    The TCE-degrading poplar endophyte Pseudomonas putida W619-TCE was inoculated in poplar cuttings, exposed to 0, 200 and 400 mg l(-1) TCE, that were grown in two different experimental setups. During a short-term experiment, plants were grown hydroponically in half strength Hoagland nutrient solution and exposed to TCE for 3 days. Inoculation with P. putida W619-TCE promoted plant growth, reduced TCE phytotoxicity and reduced the amount of TCE present in the leaves. During a mid-term experiment, plants were grown in potting soil and exposed to TCE for 3 weeks. Here, inoculation with P. putida W619-TCE had a less pronounced positive effect on plant growth and TCE phytotoxicity, but resulted in strongly reduced amounts of TCE in leaves and roots of plants exposed to 400 mg l(-1) TCE, accompanied by a lowered evapotranspiration of TCE. Dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA), which are known intermediates of TCE degradation, were not detected.

  18. Penicillin V acylases from gram-negative bacteria degrade N-acylhomoserine lactones and attenuate virulence in Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Sunder, Avinash Vellore; Utari, Putri Dwi; Ramasamy, Sureshkumar; van Merkerk, Ronald; Quax, Wim J.; Pundle, Archana

    2016-01-01

    Virulence pathways in gram-negative pathogenic bacteria are regulated by quorum sensing mechanisms, through the production and sensing of N-acylhomoserine lactone (AHL) signal molecules. Enzymatic degradation of AHLs leading to attenuation of virulence (quorum quenching) could pave the way for the d

  19. A convenient preparation of 9 H -carbazole-3,6-dicarbonitrile and 9 H -carbazole-3,6-dicarboxylic acid

    KAUST Repository

    Weselinski, Lukasz Jan

    2014-01-23

    A catalytic, high yielding and scalable procedure for the synthesis of 9H-carbazole-3,6-dicarbonitrile has been developed. Subsequent hydrolysis of the dinitrile in the presence of a catalytic copper species (i.e., CuI) yields 9H-carbazole-3,6-dicarboxylic acid. Both compounds are versatile and fine-tunable organic building blocks and therefore offer potential in material science, medicinal and supramolecular chemistry. © Georg Thieme Verlag Stuttgart New York.

  20. Naphthalene degradation by bacterial consortium (DV-AL) developed from Alang-Sosiya ship breaking yard, Gujarat, India.

    Science.gov (United States)

    Patel, Vilas; Jain, Siddharth; Madamwar, Datta

    2012-03-01

    Naphthalene degrading bacterial consortium (DV-AL) was developed by enrichment culture technique from sediment collected from the Alang-Sosiya ship breaking yard, Gujarat, India. The 16S rRNA gene based molecular analyzes revealed that the bacterial consortium (DV-AL) consisted of four strains namely, Achromobacter sp. BAB239, Pseudomonas sp. DV-AL2, Enterobacter sp. BAB240 and Pseudomonas sp. BAB241. Consortium DV-AL was able to degrade 1000 ppm of naphthalene in Bushnell Haas medium (BHM) containing peptone (0.1%) as co-substrate with an initial pH of 8.0 at 37°C under shaking conditions (150 rpm) within 24h. Maximum growth rate and naphthalene degradation rate were found to be 0.0389 h(-1) and 80 mg h(-1), respectively. Consortium DV-AL was able to utilize other aromatic and aliphatic hydrocarbons such as benzene, phenol, carbazole, petroleum oil, diesel fuel, and phenanthrene and 2-methyl naphthalene as sole carbon source. Consortium DV-AL was also efficient to degrade naphthalene in the presence of other pollutants such as petroleum hydrocarbons and heavy metals.

  1. Toxicities effects of pharmaceutical, olive mill and textile wastewaters before and after degradation by Pseudomonas putida mt-2

    Directory of Open Access Journals (Sweden)

    Mansour Hedi

    2012-02-01

    Full Text Available Abstract Background Removal of numerous classes of chemical pollutants from the industrial wastewater such as textile, pharmaceutical and olive mill using conventional wastewater treatment, is incomplete and several studies suggested that improvement of this situation would require the application of biological treatment techniques. Dyes, polyphenols and drugs are an environmental pollutants extremely toxics to plants and other living organisms including humans. These effluents were previously treated by Pseudomonas putida. The main of this work was to evaluate the in vivo toxicity of the three wastewaters. Methods Writhes and convulsant effect of effluents were carried out and were compared to the treated effluents. Only pharmaceutical wastewater was exhibited a convulsant effect which observed in mice treated by effluent. On the other hand, all industrial wastewater induced significantly an algogenic effects particularly when mice were treated by the pharmaceutical wastewater (Number of writhes = 44. Conclusion Toxicity was totally removed when mice were treated by the bio remediated effluent. This indicates that P. putida was able to completely detoxify the toxic industrial effluent.

  2. Alkaline cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Influence of pH

    Energy Technology Data Exchange (ETDEWEB)

    Huertas, M.J., E-mail: mjhuertas@us.es [Instituto de Bioquimica Vegetal y Fotosintesis, CSIC-Universidad de Sevilla Avda Americo Vespucio, 49, 41092 Sevilla (Spain); Saez, L.P.; Roldan, M.D.; Luque-Almagro, V.M.; Martinez-Luque, M. [Departamento de Bioquimica y Biologia Molecular, Edificio Severo Ochoa, 1a Planta, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain); Blasco, R. [Departamento de Bioquimica y Biologia Molecular y Genetica, Facultad de Veterinaria, Universidad de Extremadura, 11071 Caceres (Spain); Castillo, F.; Moreno-Vivian, C. [Departamento de Bioquimica y Biologia Molecular, Edificio Severo Ochoa, 1a Planta, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain); Garcia-Garcia, I. [Departamento de Ingenieria Quimica, Edificio Marie Curie, Campus de Rabanales, Universidad de Cordoba, 14071 Cordoba (Spain)

    2010-07-15

    Water containing cyanide was biologically detoxified with the bacterial strain Pseudomonas pseudoalcaligenes CECT5344 in a batch reactor. Volatilization of toxic hydrogen cyanide (HCN) was avoided by using an alkaline medium for the treatment. The operational procedure was optimized to assess cyanide biodegradation at variable pH values and dissolved oxygen concentrations. Using an initial pH of 10 without subsequent adjustment allowed total cyanide to be consumed at a mean rate of approximately 2.81 mg CN{sup -} L{sup -1} O.D.{sup -1} h{sup -1}; however, these conditions posed a high risk of HCN formation. Cyanide consumption was found to be pH-dependent. Thus, no bacterial growth was observed with a controlled pH of 10; on the other hand, pH 9.5 allowed up to 2.31 mg CN{sup -} L{sup -1} O.D.{sup -1} h{sup -1} to be converted. The combination of a high pH and a low dissolved oxygen saturation (10%) minimized the release of HCN. This study contributes new basic knowledge about this biological treatment, which constitutes an effective alternative to available physico-chemical methods for the purification of wastewater containing cyanide or cyano-metal complexes.

  3. 75 FR 27815 - Carbazole Violet Pigment 23 From China and India; Determinations

    Science.gov (United States)

    2010-05-18

    ... (Review) Carbazole Violet Pigment 23 From China and India; Determinations On the basis of the record \\1... countervailing duty order on carbazole violet pigment 23 from India would be likely to lead to continuation or... that revocation of the antidumping duty orders on carbazole violet pigment 23 from China and...

  4. Synthesis of new heteroaryldi(diindolyl)methanes: Colorimetric detection of DNA by di(diindolylmethyl)carbazoles

    Indian Academy of Sciences (India)

    Ramu Meesala; Rajagopal Nagarajan

    2009-03-01

    We have synthesized di(diindolylmethyl)carbazoles and di(diindolylmethyl)pyrroles by the reaction of substituted indoles with the corresponding carbazole and pyrroledicarboxaldehydes by employing a new catalyst PPh3.CF3SO3H. We have also demonstrated the utility of di(diindolylmethyl) carbazole derivatives for the colourimetric and fluorometric detection of DNA.

  5. 75 FR 14468 - Carbazole Violet Pigment 23 From China and India

    Science.gov (United States)

    2010-03-25

    ... COMMISSION Carbazole Violet Pigment 23 From China and India AGENCY: United States International Trade... carbazole violet pigment 23 from India and the antidumping duty orders on carbazole violet pigment 23 from China and India. SUMMARY: The Commission hereby gives notice of the scheduling of expedited...

  6. The 3,4-dihydroxyphenylacetic acid catabolon, a catabolic unit for degradation of biogenic amines tyramine and dopamine in Pseudomonas putida U.

    Science.gov (United States)

    Arcos, Mario; Olivera, Elías R; Arias, Sagrario; Naharro, Germán; Luengo, José M

    2010-06-01

    Degradation of tyramine and dopamine by Pseudomonas putida U involves the participation of twenty one proteins organized in two coupled catabolic pathways, Tyn (tynABFEC tynG tynR tynD, 12 338 bp) and Hpa (hpaR hpaBC hpaHI hpaX hpaG1G2EDF hpaA hpaY, 12 722 bp). The Tyn pathway catalyses the conversion of tyramine and dopamine into 4-hydroxyphenylacetic acid (4HPA) and 3,4-dihydroxyphenylacetic acid (3,4HPA) respectively. Together, the Tyn and Hpa pathways constitute a complex catabolic unit (the 3,4HPA catabolon) in which 3,4HPA is the central intermediate. The genes encoding Tyn proteins are organized in four consecutive transcriptional units (tynABFEC, tynG, tynR and tynD), whereas those encoding Hpa proteins constitute consecutive operons (hpaBC, hpaG1G2EDF, hpaX, hpaHI) and three independent units (hpaA, hpaR and hpaY). Genetic engineering approaches were used to clone tyn and hpa genes and then express them, either individually or in tandem, in plasmids and/or bacterial chromosomes, resulting in recombinant bacterial strains able to eliminate tyramine and dopamine from different media. These results enlarge our biochemical and genetic knowledge of the microbial catabolic routes involved in the degradation of aromatic bioamines. Furthermore, they provide potent biotechnological tools to be used in food processing and fermentation as well as new strategies that could be used for pharmacological and gene therapeutic applications in the near future.

  7. Whole genome sequence analysis of an Alachlor and Endosulfan degrading Pseudomonas strain W15Feb9B isolated from Ochlockonee River, Florida

    Directory of Open Access Journals (Sweden)

    Ashvini Chauhan

    2016-06-01

    Full Text Available We recently isolated a Pseudomonas sp. strain W15Feb9B from Ochlockonee River, Florida and demonstrated potent biodegradative activity against two commonly used pesticides - Alachlor [(2-chloro-2′,6′-diethylphenyl-N (methoxymethylacetanilide] and Endosulfan [(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9methano-2,3,4-benzo(edi-oxathiepin-3-oxide], respectively. To further identify the repertoire of metabolic functions possessed by strain W15Feb9B, a draft genome sequence was obtained, assembled, annotated and analyzed. The genome sequence of strain 2385 has been deposited in GenBank under accession number JTKF00000000; BioSample number SAMN03151543. The sequences obtained from strain 2385 assembled into 192 contigs with a genome size of 6,031,588, G + C content of 60.34, and 5512 total number of putative genes. RAST annotated a total of 542 subsystems in the genome of strain W15Feb9B along with the presence of 5360 coding sequences. A genome wide survey of strain W15Feb9B indicated that it has the potential to degrade several other pollutants including atrazine, caprolactam, dioxin, PAHs (such as naphthalene and several chloroaromatic compounds.

  8. Oligoribonuclease is the primary degradative enzyme for pGpG in Pseudomonas aeruginosa that is required for cyclic-di-GMP turnover.

    Science.gov (United States)

    Orr, Mona W; Donaldson, Gregory P; Severin, Geoffrey B; Wang, Jingxin; Sintim, Herman O; Waters, Christopher M; Lee, Vincent T

    2015-09-01

    The bacterial second messenger cyclic di-GMP (c-di-GMP) controls biofilm formation and other phenotypes relevant to pathogenesis. Cyclic-di-GMP is synthesized by diguanylate cyclases (DGCs). Phosphodiesterases (PDE-As) end signaling by linearizing c-di-GMP to 5'-phosphoguanylyl-(3',5')-guanosine (pGpG), which is then hydrolyzed to two GMP molecules by yet unidentified enzymes termed PDE-Bs. We show that pGpG inhibits a PDE-A from Pseudomonas aeruginosa. In a dual DGC and PDE-A reaction, excess pGpG extends the half-life of c-di-GMP, indicating that removal of pGpG is critical for c-di-GMP homeostasis. Thus, we sought to identify the PDE-B enzyme(s) responsible for pGpG degradation. A differential radial capillary action of ligand assay-based screen for pGpG binding proteins identified oligoribonuclease (Orn), an exoribonuclease that hydrolyzes two- to five-nucleotide-long RNAs. Purified Orn rapidly converts pGpG into GMP. To determine whether Orn is the primary enzyme responsible for degrading pGpG, we assayed cell lysates of WT and ∆orn strains of P. aeruginosa PA14 for pGpG stability. The lysates from ∆orn showed 25-fold decrease in pGpG hydrolysis. Complementation with WT, but not active site mutants, restored hydrolysis. Accumulation of pGpG in the ∆orn strain could inhibit PDE-As, increasing c-di-GMP concentration. In support, we observed increased transcription from the c-di-GMP-regulated pel promoter. Additionally, the c-di-GMP-governed auto-aggregation and biofilm phenotypes were elevated in the ∆orn strain in a pel-dependent manner. Finally, we directly detect elevated pGpG and c-di-GMP in the ∆orn strain. Thus, we identified that Orn serves as the primary PDE-B enzyme that removes pGpG, which is necessary to complete the final step in the c-di-GMP degradation pathway.

  9. Novel Complex Polymers with Carbazole Functionality by Controlled Radical Polymerization

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakabayashi

    2012-01-01

    Full Text Available This review summarizes recent advances in the design and synthesis of novel complex polymers with carbazole moieties using controlled radical polymerization techniques. We focus on the polymeric architectures of block copolymers, star polymers, including star block copolymers and miktoarm star copolymers, comb-shaped copolymers, and hybrids. Controlled radical polymerization of N-vinylcarbazole (NVC and styrene and (methacrylate derivatives having carbazole moieties is well advanced, leading to the well-controlled synthesis of complex macromolecules. Characteristic optoelectronic properties, assembled structures, and three-dimensional architectures are briefly introduced.

  10. Conditions for Pseudomonas sp.W2 Culture and Bisphenol A Degradation%Pseudomonas sp.W2生长及对双酚A降解条件的研究

    Institute of Scientific and Technical Information of China (English)

    贾凌志; 李君文

    2007-01-01

    目的 研究双酚A(BPA)降解菌(Pseudomonas sp.W2)的生长及对BPA的降解条件,为今后环境中BPA污染的实际治理提供实验依据.方法 分别采用紫外扫描光谱分析和紫外光谱分析对Pseudomonas sp.W2菌株和BPA进行定量.分别绘制Pseudomonas sp.W2菌株的生长曲线及对BPA的降解曲线,并对其在不同的碳源、氮源、pH值、温度、通气情况下的生长情况及对BPA的降解情况进行分析.结果 在一定条件下(25~35℃,pH值为6-8,250 ml摇瓶中的培养基F装液量为50~100ml,有一定的碳源、氮源),Pseudomonas sp.W2的生长及对BPA降解作用较好.结论 Pseudomonas sp.W2菌株的生长及对BPA的降解的条件较宽,这对其在实际中的应用具有一定意义.

  11. Synthesis of Carbazoles and Carbazole-Containing Heterocycles via Rhodium-Catalyzed Tandem Carbonylative Benzannulations.

    Science.gov (United States)

    Song, Wangze; Li, Xiaoxun; Yang, Ka; Zhao, Xian-liang; Glazier, Daniel A; Xi, Bao-min; Tang, Weiping

    2016-04-01

    Polycyclic aromatic compounds are important constituents of pharmaceuticals and other materials. We have developed a series of Rh-catalyzed tandem carbonylative benzannulations for the synthesis of tri-, tetra-, and pentacyclic heterocycles from different types of aryl propargylic alcohols. These tandem reactions provide efficient access to highly substituted carbazoles, furocarbazoles, pyrrolocarbazoles, thiophenocarbazoles, and indolocarbazoles. While tricyclic heterocycles could be derived from vinyl aryl propargylic alcohols, tetra- and pentacyclic heterocycles were synthesized from diaryl propargylic alcohols. The tandem carbonylative benzannulation is initiated by a π-acidic rhodium(I) catalyst-mediated nucleophilic addition to alkyne to generate a key metal-carbene intermediate, which is then trapped by carbon monoxide to form a ketene species for 6π electrocyclization. Overall, three bonds and two rings are formed in all of these tandem carbonylative benzannulation reactions.

  12. 7H-1-Benzofuro[2,3-b]carbazole

    Directory of Open Access Journals (Sweden)

    V. Manivannan

    2011-10-01

    Full Text Available In the title compound, C18H11NO, the carbazole and benzofuran rings are almost co-planar, making a dihedral angle of 3.31 (3°. The crystal structure is stabilized by weak C—H...π interactions.

  13. Carbazole functionalized isocyanide brushes in heterojunction photovoltaic devices

    NARCIS (Netherlands)

    Lim, E.; Gao, F.; Schwartz, E.; Cornelissen, J.J.L.M.; Nolte, R.J.M.; Rowan, A.E.; Greenham, N.C.; Do, L.M.

    2012-01-01

    In this work, carbazole-containing polyisocyanide (PIACz) brushes were used for photovoltaic devices. A photovoltaic device was fabricated on top of the brushes by spin-coating a suitable acceptor and evaporating an Al cathode. Devices with a poly(N-vinylcarbazole) (PVK) bulk polymer were also prepa

  14. Synthesis and Photophysical Properties of C60-carbazole Adducts

    Institute of Scientific and Technical Information of China (English)

    YIN ,Gui(尹桂); YIN,Gui; MAO,Xin-Ping(毛新平); MAO,Xin-Ping; SUO,Zhi-Yong(锁志勇); SUO,Zhi-Yong; XU,Zheng(徐正); XU,Zheng

    2001-01-01

    Three C60-cartazole adducts have been synthesized by 1,3-dipolar cycloaddition reaction.Intramolecular energy/electron transfer from carbazole to C60 was observed by steady-state absorption and fluorescence spectra.The fluorescence spectra of these adducts were similau to each other and dependent on the excitation wavelength and solvent.

  15. Synthesis, Characterization, and Surface Initiated Polymerization of Carbazole Functionalized Isocyanides

    NARCIS (Netherlands)

    Schwartz, Erik; Lim, Eunhee; Gowda, Chandrakala M.; Liscio, Andrea; Fenwick, Oliver; Tu, Guoli; Palermo, Vincenzo; Gelder, de Rene; Cornelissen, Jeroen J.L.M.; Eck, van Ernst R.H.; Kentgens, Arno P.M.; Cacialli, Franco; Nolte, Roeland J.M.; Samori, Paolo; Huck, Wilhelm T.S.; Rowan, Alan E.

    2010-01-01

    We describe the design and synthesis of carbazole functionalized isocyanides and the detailed investigation of their properties. Characterization by solid state NMR, CD, and IR spectroscopic techniques reveals that the polymer has a well-defined helical architecture. Surface-initiated polymerization

  16. Pseudomonas - Fact Sheet

    OpenAIRE

    Public Health Agency

    2012-01-01

    Fact sheet on Pseudomonas, including:What is Pseudomonas?What infections does it cause?Who is susceptible to pseudomonas infection?How will I know if I have pseudomonas infection?How can Pseudomonas be prevented from spreading?How can I protect myself from Pseudomonas?How is Pseudomonas infection treated?

  17. Multivariate analysis of microarray data by principal component discriminant analysis: Prioritizing relevant transcripts linked to the degradation of different carbohydrates in Pseudomonas putida S12

    NARCIS (Netherlands)

    Werf, M.J. van der; Pieterse, B.; Luijk, N. van; Schuren, F.; Werff van der - Vat, B. van der; Overkamp, K.; Jellema, R.H.

    2006-01-01

    The value of the multivariate data analysis tools principal component analysis (PCA) and principal component discriminant analysis (PCDA) for prioritizing leads generated by microarrays was evaluated. To this end, Pseudomonas putida S12 was grown in independent triplicate fermentations on four diffe

  18. CHARACTERIZATION AND NUCLEOTIDE SEQUENCE DETERMINATION OF A REPEAT ELEMENT ISOLATED FROM A 2,4,5,-T DEGRADING STRAIN OF PSEUDOMONAS CEPACIA

    Science.gov (United States)

    Pseudomonas cepacia strain AC1100, capable of growth on 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), was mutated to the 2,4,5-T− strain PT88 by a ColE1 :: Tn5 chromosomal insertion. Using cloned DNA from the region flanking the insertion, a 1477-bp sequence (designated RS1100) wa...

  19. Quantitative analysis of bioactive carbazole alkaloids in Murraya koenigii.

    Science.gov (United States)

    Joshi, Trapti; Mahar, Rohit; Singh, Sumit K; Srivastava, Piush; Shukla, Sanjeev K; Mishra, Dipak K; Bhatta, R S; Kanojiya, Sanjeev

    2015-02-01

    Carbazole alkaloids induce apoptosis in HL-60 cells through activation of the caspase-9/caspase-3 pathway and they are targeted as potential anticancer agents. Thus, the naturally occurring carbazole alkaloids become important as precursors for lead optimization in drug development. A method based on ultra performance liquid chromatography coupled with photodiode-array detection was developed using reverse phase isocratic elution with 85:15 acetonitrile and ammonium acetate buffer (5 mM). Seven samples of Murrya koenigii (L.) Spreng. from north-central India (Uttar Pradesh) were analyzed. All three targeted analytes, koenimbidine (mk1), koenimbine (mk2) and mahanimbine (mk3), were well separated within 4.0 min with linearity of the calibration curves (r2 > 0.999). The limits of detection and quantification of mk1, mk2 and mk3 were 0.7, 0.4, 0.04 μg/mL and 2.14, 1.21, 0.12 μg/mL, respectively. The natural abundance of mk1, mk2 and mk3 was 0.06-0.20, 0.04-0.69 and 0.13-0.42%, w/w, respectively, in the dried powdered leaves, whereas, the tissue specific distribution of carbazole alkaloids was observed in the order of predominance, mk1 leaf>root>fruit>stem, mk2 fruit>leaf >stem>root, and mk3 fruit>leaf>root>stem. The developed method was validated for limits of detection and quantification, repeatability, accuracy, precision and stability. This is the first report on the natural abundance of the major carbazole alkaloids in M. koenigii and the method developed can be used in HPLC/UPLC systems.

  20. 9-Ethyl-3,6-diformyl-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Jun Jie Wang

    2008-07-01

    Full Text Available The structure of the title compound, C16H13NO2, was determined as a part of a project on the synthesis of new compounds which can make two-photon absorptions. In the crystal structure, both aldehyde groups are located within the carbazole plane. One of these groups is disordered and was refined using a split model with site-occupation factors for each position of 0.5.

  1. 9-(4-Bromophenyl-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Paul Kautny

    2014-03-01

    Full Text Available In the title molecule, C18H12BrN, the 4-bromophenyl ring is inclined to the mean plane of the carbazole moiety (r.m.s. devation = 0.027 Å by 49.87 (5°. In the crystal, molecules stack along [001] and are linked by C—H...π interactions forming a corrugated two-dimensional network lying parallel to (100.

  2. (4,9-Dimethyl-9H-carbazol-3-ylmethanol

    Directory of Open Access Journals (Sweden)

    Serkan Öncüoğlu

    2014-03-01

    Full Text Available In the title compound, C15H15NO, the carbazole skeleton includes a methanol group at the 3-position. The indole ring system is almost planar [maximum deviation = 0.045 (2 Å]. In the crystal, O—H...O hydrogen bonds link the molecules into zigzag chains along the b-axis direction. There are weak C—H...π interactions within the chains and linking neighbouring chains forming sheets lying parallel to (001.

  3. Alternative products to carbazoles in the oxidation of diphenylamines with palladium (II) acetate

    OpenAIRE

    Raposo, M. Manuela M.; Campos, Ana M. F. Oliveira; Shannon, Patrick V. R.

    1997-01-01

    Although simple diphenylamines are conveniently oxidised with Palladium (II) acetate to give carbazoles, for more complex examples, carbazoles are minor products amongst many. CRUP (Portugal). British Council - Treaty of Windsor Programme. Junta Nacional de Investigação Científica e Tecnológica.

  4. Isolation of oxygenase genes for indigo-forming activity from an artificially polluted soil metagenome by functional screening using Pseudomonas putida strains as hosts.

    Science.gov (United States)

    Nagayama, Hirofumi; Sugawara, Tomonori; Endo, Ryo; Ono, Akira; Kato, Hiromi; Ohtsubo, Yoshiyuki; Nagata, Yuji; Tsuda, Masataka

    2015-05-01

    Metagenomes contain the DNA from many microorganisms, both culturable and non-culturable, and are a potential resource of novel genes. In this study, a 5.2-Gb metagenomic DNA library was constructed from a soil sample (artificially polluted with four aromatic compounds, i.e., biphenyl, phenanthrene, carbazole, and 3-chlorobenzoate) in Escherichia coli by using a broad-host-range cosmid vector. The resultant library was introduced into naphthalene-degrading Pseudomonas putida-derived strains having deficiencies in their naphthalene dioxygenase components, and indigo-forming clones on the indole-containing agar plates were screened. Cosmids isolated from 29 positive clones were classified by their various properties (original screening hosts, hosts showing indigo-forming activity, and digestion patterns with restriction enzymes), and six representative cosmids were chosen. Sequencing and in vitro transposon mutagenesis of the six cosmids resulted in the identification of genes encoding putative class B and D flavoprotein monooxygenases, a multicomponent hydroxylase, and a reductase that were responsible for the indigo-forming activity in the host cells. Among them, the genes encoding the multicomponent hydroxylase were demonstrated to be involved in phenol degradation. Furthermore, two genes encoding ring-cleavage dioxygenases were also found adjacent to the genes responsible for the indigo formation, and their functions were experimentally confirmed.

  5. Kinetic Characteristics of Degradation of Petroleum by Pseudomonas SY5%一种假单胞菌SY5降解石油的动力学研究

    Institute of Scientific and Technical Information of China (English)

    冯晋阳; 吴小宁

    2011-01-01

    为了确定石油降解菌对石油污染物的生物降解特性,选用分离得到的一株石油降解菌假单胞菌SY5,对其降解石油污染物的动力学特性进行了研究.研究结果表明,在30℃,pH=7.2的反应条件下,所筛选的SY5菌对石油具有良好的降解能力,降解石油的反应基本符合一级反应动力学,且随石油初始浓度的增大,SY5降解石油的速率减小,降解受到抑制.在生物降解的过程中,SY5的生长曲线具有明显增长和衰减曲线.在生长阶段,产率系数y值为0.3873.在内源呼吸阶段,衰减系数bd值为0.1805d-1,SY5菌自身氧化速度比较快.SY5生物降解石油Monod方程的最大比增长速率μmax和半饱和常数Ks分别为1.6d-1和150mg/L.%In order to decide the biodegradation characteristics of petroleum-degrading strains, the kinetic characteristics of degradation of petroleum pollutants by an isolated pseudomonas SY5 were studied. The conditions of reaction were 30 C and pH 7. 2. The results showed that the isolated pseudomonas SY5 was found good at degrading oil and the degradation reaction behaved as a pseudo-first-order kinetics reaction. With the increase of the initial concentration of oil, the degradation slowed down and was restrained. In the process of biodegradation, the growth curve of SY5 was an obvious growth and decay curve. The yield coefficient (Y) was 0. 3873 mg cell/mg oil in the growth phase. In the endogenous phase, the decay coefficient was 0. 1805 d~'and the rate of auto-digestion of SY5 was higher. In the Monod expression, the values of the maximum specific rate (/u^) and the half-saturation coefficient (Ks) were 1. 6d~l and 150 mg/L respectively.

  6. Effects of TX-100 on Biphenol A Degradation in Biofilm by Pseudomonas Putida%曲拉通(TX-100)对恶臭假单胞菌降解生物膜中双酚A的影响

    Institute of Scientific and Technical Information of China (English)

    李都峰; 赵文晋; 黎娜; 王宪恩

    2009-01-01

    研究非离子型表面活性剂曲拉通(TX-100)对恶臭假单胞菌降解生物膜中双酚A的影响. 结果表明, 低浓度(小于临界胶束浓度, CMC)TX-100抑制生物膜中双酚A的降解, 而高浓度(大于CMC)TX-100可促进生物膜中双酚A的降解, 并且随着生物膜中TX-100浓度的增加, 双酚A的降解率逐渐增大;同时发现TX-100存在条件下生物膜主要化学组分的选择性萃取分离可导致恶臭假单胞菌降解双酚A的能力下降.%Effect of non-ionic surfactant TX-100 on biphenol A (BPA) degradation in the natural surface coatings by Pseudomonas putida was investigated. TX-100 inhibits the biodegradation of BPA in biofilm at low concentrations ( 1.0 times of CMC), and the degradation rate of BPA increases gradually with the increase of BPA concentration. The removal of the main components of the natural surface coatings by the selective extraction techniques has an effect on the BPA degradation, leading to a significant decrease in the biodegradation of BPA.

  7. Patchwork assembly of nag-like nitroarene dioxygenase genes and the 3-chlorocatechol degradation cluster for evolution of the 2-chloronitrobenzene catabolism pathway in Pseudomonas stutzeri ZWLR2-1.

    Science.gov (United States)

    Liu, Hong; Wang, Shu-Jun; Zhang, Jun-Jie; Dai, Hui; Tang, Huiru; Zhou, Ning-Yi

    2011-07-01

    Pseudomonas stutzeri ZWLR2-1 utilizes 2-chloronitrobenzene (2CNB) as a sole source of carbon, nitrogen, and energy. To identify genes involved in this pathway, a 16.2-kb DNA fragment containing putative 2CNB dioxygenase genes was cloned and sequenced. Of the products from the 19 open reading frames that resulted from this fragment, CnbAc and CnbAd exhibited striking identities to the respective α and β subunits of the Nag-like ring-hydroxylating dioxygenases involved in the metabolism of nitrotoluene, nitrobenzene, and naphthalene. The encoding genes were also flanked by two copies of insertion sequence IS6100. CnbAa and CnbAb are similar to the ferredoxin reductase and ferredoxin for anthranilate 1,2-dioxygenase from Burkholderia cepacia DBO1. Escherichia coli cells expressing cnbAaAbAcAd converted 2CNB to 3-chlorocatechol with concomitant nitrite release. Cell extracts of E. coli/pCNBC exhibited chlorocatechol 1,2-dioxygenase activity. The cnbCDEF gene cluster, homologous to a 3-chlorocatechol degradation cluster in Sphingomonas sp. strain TFD44, probably contains all of the genes necessary for the conversion of 3-chlorocatechol to 3-oxoadipate. The patchwork-like structure of this catabolic cluster suggests that the cnb cluster for 2CNB degradation evolved by recruiting two catabolic clusters encoding a nitroarene dioxygenase and a chlorocatechol degradation pathway. This provides another example to help elucidate the bacterial evolution of catabolic pathways in response to xenobiotic chemicals.

  8. Salicylic acid degradation from aqueous solutions using Pseudomonas fluorescens HK44: parameters studies and application tools Degradação de ácido salicílico presente em soluções sintéticas utilizando Pseudomonas fluorescens HK44

    Directory of Open Access Journals (Sweden)

    Tatyane R. Silva

    2007-03-01

    Full Text Available The optimal conditions for salicylic acid biodegradation by Pseudomonas fluorescens HK44 were determined in this study with the intention to create a microbial sensor. Kinetic experiments permitted a definition of 60 and 30min the time needed to achieve the maximum degradation of salicylic acid presented in a medium with and without yeast extract, respectively. The degradation in medium without yeast extract and the quantification by spectrophotometry 230 nm were selected to be used in further tests. The use of preactivated cells or on the exponential growth phase showed better salicylic acid degradation percentages when compared to nonactivated cells or on the stationary growth state. Finally, the best cellular concentration used on the salicylic acid degradation was 0,1 g.L-1. Strain HK44 shows to be capable of degrade salicylic acid presented in simple aqueous systems, making this strain a promising tool for the application on a luminescent microbial sensor.Com a intenção de criar um sensor microbiano, as condições ótimas para a biodegradação de ácido salicílico por Pseudomonas fluorescens HK44 foram determinadas neste estudo. Os experimentos cinéticos permitiram a definição dos tempos de 60 e 30 minutos como necessários para atingir a máxima degradação de ácido salicílico presente em meio com ou sem extrato de lêvedo, respectivamente. A degradação no meio sem extrato de lêvedo e a quantificação através de espectrofotometria 230 nm foram selecionadas para serem utilizadas em testes posteriores. O uso de células pré-ativadas ou na fase exponencial de crescimento apresentou melhores porcentagens de degradação de ácido salicílico quando comparadas a células não-ativadas ou no estado estacionário de crescimento. Além disso, a melhor concentração celular utilizada nessa degradação foi 0,1 g.L¹. A cepa HK44 parece ser capaz de degradar o ácido salicílico presente em sistemas aquosos simples, tornando este

  9. Homologues of Neisserial Heme Oxygenase in Gram-Negative Bacteria: Degradation of Heme by the Product of the pigA Gene of Pseudomonas aeruginosa

    OpenAIRE

    2001-01-01

    The oxidative cleavage of heme to release iron is a mechanism by which some bacterial pathogens can utilize heme as an iron source. The pigA gene of Pseudomonas aeruginosa is shown to encode a heme oxygenase protein, which was identified in the genome sequence by its significant homology (37%) with HemO of Neisseria meningitidis. When the gene encoding the neisserial heme oxygenase, hemO, was replaced with pigA, we demonstrated that pigA could functionally replace hemO and allow for heme util...

  10. A complete gear system in N-benzoyl-carbazole derivatives.

    Science.gov (United States)

    Tabata, Hidetsugu; Kayama, Susumu; Takahashi, Yuka; Tani, Norihiko; Wakamatsu, Shintaro; Tasaka, Tomohiko; Oshitari, Tetsuta; Natsugari, Hideaki; Takahashi, Hideyo

    2014-03-07

    2',6'-Disubstituted N-benzoylated carbazole derivatives were found to exhibit atropisomerism. The bulky substituents restricted rotation about the N-C7' and C7'-C1' bonds to separate four atropisomers, in which rotation about the C7'-C1' bond was in perfect concert with rotation about the N-C7' bond. Complete geared rotation without slippage at 37 °C for 7 days was observed for the first time. Conformational analysis clarified the preference for the gear system over other internal conversion pathways.

  11. Electronic transitions of fluorene, dibenzofuran, carbazole, and dibenzothiophene

    DEFF Research Database (Denmark)

    Nguyen, Duy Duc; Trunk, John; Nakhimovsky, Lina;

    2010-01-01

    A comparative study of the electronic transitions of fluorene and its hetero-analogues dibenzofuran, carbazole, and dibenzothiophene was performed in a wide energy range. Gas phase, crystal phase, and linear dichroism electronic transmittance spectra were measured with synchrotron radiation....... Prediction of electronic transitions to excited singlet states was performed by using time-dependent density functional theory TD-B3LYP/6-31+G(d,p). Based on the experimental and theoretical results, symmetry assignments of electronic transitions in the vacuum and near-UV region are suggested...

  12. Synthesis and photoluminescence of a dendritic europium complex with carbazole moieties

    Institute of Scientific and Technical Information of China (English)

    ZHENG Youxuan; ZHOU Yonghui; Gianluca Accorsi; Nicola Armaroli

    2008-01-01

    A novel dendritic europium complex containing grafted carbazole units as functional peripheries was synthesized and characterized. The Forster energy transfer from the peripheries of carbazole units to β-diketonate as well as from the ligands to the central Eu(III) ions in the complex was demonstrated. Under the excitation of carbazole units and β-diketonate, characteristic red emission peaks at 612 nm with four shoulders due to the Eu(III) ion transition of 5D0→7FJ (J=0-4) were observed for the complex.

  13. Evaluation of genotoxicity and pro-oxidant effect of the azo dyes: acids yellow 17, violet 7 and orange 52, and of their degradation products by Pseudomonas putida mt-2.

    Science.gov (United States)

    Ben Mansour, Hedi; Corroler, David; Barillier, Daniel; Ghedira, Kamel; Chekir, Leila; Mosrati, Ridha

    2007-09-01

    Acids yellow 17, violet 7 and orange 52, very important commercial azo dyes used in the textile, food, paper and cosmetic industries, were degraded by Pseudomonas putida mt-2 at concentrations up to 100mg/l. The culture media was completely decolorized under static incubation for 60 h, this faster than under continuous shaking incubation. SOS chromotest using Escherichia coli PQ37, with and without metabolic activation (S-9 preparations), was used to assess genotoxicity potential of these dyes before and after biodegradation. None of these dyes or their metabolites was found to be genotoxic in the absence of "Araclor-Induced rat liver microsome" preparations (S-9). However, in presence of the preparation S-9, the genotoxicity of the biodegradation products was highlighted. Metabolites resulting from static cultures were more genotoxic than those obtained in shaken conditions. In addition to genotoxic effects, metabolites have shown a significant ability to induce the formation of superoxide free radical anion (O(2)(*-)). The toxicities generated by the pure azo dyes and the pure azo-reduction products (sulfanilic acid, N,N'-dimethyl-p-phenylenediamine and 4'-aminoacetanilid) were compared. These results suggest that P. putida mt-2 degrades the studied azo dyes in two steps: an azo-reduction followed by an oxygen-dependent metabolization. Some of the derived metabolites would be responsible of genotoxicity and metabolic toxicity.

  14. The Potential of the Ni-Resistant TCE-Degrading Pseudomonas putida W619-TCE to Reduce Phytotoxicity and Improve Phytoremediation Efficiency of Poplar Cuttings on A Ni-TCE Co-Contamination.

    Science.gov (United States)

    Weyens, Nele; Beckers, Bram; Schellingen, Kerim; Ceulemans, Reinhart; van der Lelie, Daniel; Newman, Lee; Taghavi, Safiyh; Carleer, Robert; Vangronsveld, Jaco

    2015-01-01

    To examine the potential of Pseudomonas putida W619-TCE to improve phytoremediation of Ni-TCE co-contamination, the effects of inoculation of a Ni-resistant, TCE-degrading root endophyte on Ni-TCE phytotoxicity, Ni uptake and trichloroethylene (TCE) degradation of Ni-TCE-exposed poplar cuttings are evaluated. After inoculation with P. putida W619-TCE, root weight of non-exposed poplar cuttings significantly increased. Further, inoculation induced a mitigation of the Ni-TCE phytotoxicity, which was illustrated by a diminished exposure-induced increase in activity of antioxidative enzymes. Considering phytoremediation efficiency, inoculation with P. putida W619-TCE resulted in a 45% increased Ni uptake in roots as well as a slightly significant reduction in TCE concentration in leaves and TCE evapotranspiration to the atmosphere. These results indicate that endophytes equipped with the appropriate characteristics can assist their host plant to deal with co-contamination of toxic metals and organic contaminants during phytoremediation. Furthermore, as poplar is an excellent plant for biomass production as well as for phytoremediation, the obtained results can be exploited to produce biomass for energy and industrial feedstock applications in a highly productive manner on contaminated land that is not suited for normal agriculture. Exploiting this land for biomass production could contribute to diminish the conflict between food and bioenergy production.

  15. Modulation of π-spacer of carbazole-carbazole based organic dyes toward high efficient dye-sensitized solar cells

    Science.gov (United States)

    Chitpakdee, Chirawat; Jungsuttiwong, Siriporn; Sudyoadsuk, Taweesak; Promarak, Vinich; Kungwan, Nawee; Namuangruk, Supawadee

    2017-03-01

    The effects of type and position of π-linker in carbazole-carbazole based dyes on their performance in dye-sensitized solar cells (DSSCs) were investigated by DFT and TDDFT methods. The calculated electronic energy level, electron density composition, charge injection and charge recombination properties were compared with those of the high performance CCT3A dye synthesized recently. It is found that that mixing a benzothiadizole (B) unit with two thiophene (T) units in the π-spacer can greatly shift absorption wavelength to near infrared region and enhance the light harvesting efficiency (LHE) resulting in increasing of short-circuit current density (Jsc), whereas a thienothiophene unit does not affect those properties. However, a B should be not directly connected to the anchoring group of the dye because it brings electrolyte to the TiO2 surface which may increase charge recombination rate and consequently decrease open circuit voltage (Voc). This work shows how type and position of the π-linker affect the performance of DSSCs, and how to modulate those properties. We predicted that the designed dye derived from insertion of the B unit in between the two T units would have higher performance than CCT3A dye. The insight understanding from this study is useful for further design of higher performance dyes by molecular engineering.

  16. Novel Blue Light-emitting PPV-based Copolymer Containing Triazole and Carbazole Units

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel alternating conjugated copolymer containing triazole and carbazole units was synthesized by the Wittig reaction. The resulting bipolar conjugated polymer emits a pure light with good thermal stability, which is a promising candidate for polymer light emitting display.

  17. Novel Blue Light—emitting PPV—based Copolymer Containing Trazole and Carbazole Units

    Institute of Scientific and Technical Information of China (English)

    ZeLIU; LiXiangWANG; 等

    2002-01-01

    A novel alternating conjugated copolymer containing triazole and carbazole units was synthesized by the Witting reaction. The resulting bipolar conjugated polymer emits a pure light with good thermal stability, which is a promising candidate for polymer light emitting display.

  18. Copper catalyzed synthesis of quinolinopyrano[2,3-]carbazole derivatives via Povarov reaction

    Indian Academy of Sciences (India)

    Subburethinam Ramesh; Rajagopal Nagarajan

    2014-07-01

    An efficient procedure for the synthesis of pyranocarbazole derivatives using copper catalysed Povarov reaction between aromatic amines and -propargyl carbazole carboxaldehyde has been developed. Ionic liquid is found to be a good solvent medium.

  19. Synthesis of Novel Derivatives of Carbazole-Thiophene, Their Electronic Properties, and Computational Studies

    Directory of Open Access Journals (Sweden)

    E. F. Damit

    2016-01-01

    Full Text Available A series of carbazole-thiophene dimers, P1–P9, were synthesized using Suzuki-Miyaura and Ullmann coupling reactions. In P1–P9, carbazole-thiophenes were linked at the N-9 position for different core groups via biphenyl, dimethylbiphenyl, and phenyl. Electronic properties were evaluated by UV-Vis, cyclic voltammogram, and theoretical calculations. Particularly, the effects of conjugation connectivity on photophysical and electrochemical properties, as well as the correlation between carbazole-thiophene and the core, were studied. Carbazole connecting with thiophenes at the 3,6-positions and the phenyl group as a core group leads to increased stabilization of HOMO and LUMO energy levels where the bandgap (ΔE is significantly reduced.

  20. Degradation of tea saponin in the oil tea cake by Pseudomonas aeruginosa%铜绿假单胞菌降解油茶饼(粕)中茶皂素的研究

    Institute of Scientific and Technical Information of China (English)

    黄浦; 肖瑜; 刘以清; 覃妍; 陈菊清

    2015-01-01

    以油茶饼(粕)为原料,以茶皂素降解率为评价指标,利用铜绿假单胞菌液态发酵降解油茶饼(粕)中的茶皂素以及对发酵液中成分的研究,通过改变发酵时间、发酵温度、摇床转速、接种量等单因素实验,得到最佳的发酵条件为:发酵时间13 d ,发酵温度29℃,摇床转速150 r/min ,菌悬液接种量9.0 ml/(100 ml),在此条件下,茶皂素的降解率达到了71.95%,并对发酵产物采用GC‐M S进行了成分分析。%Using oil tea cake as raw material ,with tea saponin degradation rate as the evaluation index ,tea saponin in the oil tea cake was degradated by liquid fermentation of Pseudomonas aeruginosa ,the composition of fermented liquid was studied , and the optimum fermentation conditions were determined by single factor fermentation experiments of fermentation time ,tem‐perature ,rotation speed and inoculum size ,etc .The optimum fermentation degradation conditions were studied as :fermentation time 13 d ,fermentation temperature 29℃ ,rotating speed 150 r/min and inoculum size 9 ml/(100 ml) .Under the conditions ,the decomposition rate of tea saponin was 71 .95% ,and the fermented product composition was analyzed by GC‐MS .

  1. Research on polyfluorene derivatives end-capped by N-hexyl-carbazole and benzene

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Copolymers of 9,9-dioctylfluorene (DOF) and 2-thienyl-benzothiadiazole (DBT) were synthesized by Suzuki reaction and end-capped by N-hexyl-carbazole and benzene, which were abbreviated as PDOF-DBT-Cz and PDOF-DBT-B, respectively. The photophysical, electrochemical and thermal properties of the copolymers were studied. The results indicated that replacement of N-hexyl-carbazole as end-capping group of PDOF-DBT can vary light color and improve luminescence efficiency.

  2. Carbazole is a naturally occurring inhibitor of angiogenesis and inflammation isolated from antipsoriatic coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Jack L. Arbiser; Baskaran Govindarajan; Traci E. Battle; Rebecca Lynch; David A. Frank; Masuko Ushio-Fukai; Betsy N. Perry; David F. Stern; G. Tim Bowden; Anquan Liu; Eva Klein; Pawel J. Kolodziejski; N. Tony Eissa; Chowdhury F. Hossain; Dale G. Nagle [Emory University School of Medicine, Atlanta, GA (United States). Department of Dermatology

    2006-06-15

    Coal tar is one of the oldest and an effective treatment for psoriasis. Coal tar has been directly applied to the skin, or used in combination with UV light as part of the Goeckerman treatment. The use of coal tar has caused long-term remissions in psoriasis, but has fallen out of favor because the treatment requires hospitalization and coal tar is poorly acceptable aesthetically to patients. Thus, determining the active antipsoriatic component of coal tar is of considerable therapeutic interest. We fractionated coal tar into its components, and tested them using the SVR angiogenesis inhibitor assay. Treatment of SVR endothelial cells with coal tar fractions resulted in the isolation of a single fraction with antiangiogenic activity. The active antiangiogenic compound in coal tar is carbazole. In addition to antiangiogenic activity, carbazole inhibited the production of inflammatory IL-15 by human mononuclear cells. IL-15 is elevated in psoriasis and is thought to contribute to psoriatic inflammation. Carbazole treatment also reduced activity of inducible nitric oxide synthase (iNOS), which is proinflammatory and elevated in psoriasis. The effect of carbazole on upstream pathways in human psoriasis was determined, and carbazole was shown to inhibit signal transducer and activator of transcription (stat)3-mediated transcription, which has been shown to be relevant in human psoriasis. IL-15, iNOS, and stat3 activation require the activation of the small GTPase rac for optimal activity. Carbazole was found to inhibit rac activation as a mechanism for its inhibition of downstream inflammatory and angiogenic pathways. Given its antiangiogenic and anti-inflammatory activities, carbazole is likely a major component of the antipsoriatic activity of coal tar. Carbazole and derivatives may be useful in the therapy of human psoriasis.

  3. N-[(9-Ethyl-9H-carbazol-3-ylmethylene]-3,4-dimethylisoxazol-5-amine

    Directory of Open Access Journals (Sweden)

    Abdullah Mohamed Asiri

    2010-05-01

    Full Text Available The title compound, N-[(9-ethyl-9H-carbazol-3-ylmethylene]-3,4-dimethylisoxazol-5-amine has been synthesized by reaction of 9-ethyl-9H-carbazole-3-carbaldehyde with 5-amino-3,4-dimethylisoxazole in the presence of acetic acid in ethanol. The structure of this new compound was confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR and EI-MS spectral analysis.

  4. Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate:quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain.

    Science.gov (United States)

    Luque-Almagro, Victor M; Merchán, Faustino; Blasco, Rafael; Igeño, M Isabel; Martínez-Luque, Manuel; Moreno-Vivián, Conrado; Castillo, Francisco; Roldán, M Dolores

    2011-03-01

    The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to grow with cyanide as the sole nitrogen source. Membrane fractions from cells grown under cyanotrophic conditions catalysed the production of oxaloacetate from L-malate. Several enzymic activities of the tricarboxylic acid and glyoxylate cycles in association with the cyanide-insensitive respiratory pathway seem to be responsible for the oxaloacetate formation in vivo. Thus, in cyanide-grown cells, citrate synthase and isocitrate lyase activities were significantly higher than those observed with other nitrogen sources. Malate dehydrogenase activity was undetectable, but a malate:quinone oxidoreductase activity coupled to the cyanide-insensitive alternative oxidase was found in membrane fractions from cyanide-grown cells. Therefore, oxaloacetate production was linked to the cyanide-insensitive respiration in P. pseudoalcaligenes CECT5344. Cyanide and oxaloacetate reacted chemically inside the cells to produce a cyanohydrin (2-hydroxynitrile), which was further converted to ammonium. In addition to cyanide, strain CECT5344 was able to grow with several cyano derivatives, such as 2- and 3-hydroxynitriles. The specific system required for uptake and metabolization of cyanohydrins was induced by cyanide and by 2-hydroxynitriles, such as the cyanohydrins of oxaloacetate and 2-oxoglutarate.

  5. Isolation of Strain Pseudomonas sp.DY12 with Degrading Petroleum Activity and Studies on Its Degrading Performance%石油降解菌株Pseudomonas sp.DY12的筛选及降解性能研究

    Institute of Scientific and Technical Information of China (English)

    王战勇; 顾贵洲; 苏婷婷; 唐志强

    2009-01-01

    从石油炼厂污染土壤中筛选出具有石油降解能力的菌株Pseudomonas sp.DY12,并对其降解石油烃能力进行了研究.考察了培养温度、接种量、培养基初始pH值、培养时间及摇床转速对菌株降解性能的影响,优选出菌株Pseudomonas sp.DY12降解石油烃的最佳条件,即:培养时间4 d、菌悬液接种量4%(体积分数)、培养温度30℃、培养基初始pH值7.0~8.0、摇床转速160 r·min-1,在此条件下菌株Pseudomonas sp.DY12对石油烃的降解率可达69.4%.

  6. Ethyl 2-(1,2,3,4-tetrahydrospiro[carbazole-3,2′-[1,3]dioxolan]-9-ylacetate

    Directory of Open Access Journals (Sweden)

    Philipp M. G. Löffler

    2009-04-01

    Full Text Available In the title compound, C18H21NO4, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation. The dioxolane ring and ethylacetate substituent point to opposite sides of the carbazole plane. The ethylacetate substituent adopts an essentially fully extended conformation, and its mean plane forms a dihedral angle of 83.8 (1° with respect to the carbazole mean plane. The molecules are arranged into stacks in which the carbazole planes form a dihedral angle of 4.4 (1° and have an approximate interplanar separation of 3.6 Å.

  7. [Environmental Behaviors and Ecotoxicology of the Emerging Contaminants Polyhalogenated Carbazoles].

    Science.gov (United States)

    Lin, Kun-de; Chen, Yan-qiu; Yuan, Dong-xing

    2016-04-15

    Polyhalogenated carbazoles (PHCs), with a complex chemical structure similar to polychlorinated dibenzofurans, are a class of emerging environmental organic contaminants. There are 135 congeners for PHCs with a pure halogenation. Most of PHCs are not man-made products. Although PHCs in the environment were firstly discovered in the 1980s, these emerging halogenated compounds were not seriously considered until recent years. Recently, more than 20 PHCs have been detected in sediment and soil samples. In addition, studies have shown that PHCs exhibited dioxin-like toxicity and were persistent and bioaccumulative. Therefore, it is very important to understand the distribution, origins and ecotoxicology of PHCs for a better assessment of their environmental risks. To date, research on the environmental behaviors of PHCs is relatively limited and warrants further investigations. In this review, the environmental distribution, source, analytical methods and toxicity of PHCs were summarized and future research needs were outlined.

  8. Rationally rewiring the connectivity of the XylR/Pu regulatory node of the m-xylene degradation pathway in Pseudomonas putida.

    Science.gov (United States)

    de Las Heras, Aitor; Martínez-García, Esteban; Domingo-Sananes, Maria Rosa; Fraile, Sofia; de Lorenzo, Víctor

    2016-04-18

    The XylR/Pu regulatory node of the m-xylene biodegradation pathway of Pseudomonas putida mt-2 is one of the most intricate cases of processing internal and external cues into a single controlling element. Despite this complexity, the performance of the regulatory system is determined in vivo only by the occupation of Pu by m-xylene-activated XylR and σ(54)-RNAP. The stoichiometry between these three elements defines natural system boundaries that outline a specific functional space. This space can be expanded artificially following different strategies that involve either the increase of XylR or σ(54) or both elements at the same time (each using a different inducer). In this work we have designed a new regulatory architecture that drives the system to reach a maximum performance in response to one single input. To this end, we first explored using a simple mathematical model whether the output of the XylR/Pu node could be amended by simultaneously increasing σ(54) and XylR in response to only natural inducers. The exacerbation of Pu activity in vivo was tested in strains bearing synthetic transposons encoding xylR and rpoN (the σ(54) coding gene) controlled also by Pu, thereby generating a P. putida strain with the XylR/Pu output controlled by two intertwined feed forward loops (FFLs). The lack of a negative feedback loop in the expression node enables Pu activity to reach its physiological maximum in response to a single input. Only competition for cell resources might ultimately check the upper activity limit of such a rewired m-xylene sensing device.

  9. Oegylated and cross-linking carbazole dendrons and dendrimers: Synthesis, characterization, assembly and thin film fabrication

    Science.gov (United States)

    Felipe, Mary Jane Legaspi

    2011-12-01

    Dendrimers and dendrons (fractional dendrimers) are macromolecular structures that have well-defined molecular weights and precise number of functional groups. Tailoring these structures has provided designer molecules that can be used for various applications including drug delivery, sensors, and anti-biofouling surfaces. Overall, this dissertation provides novel protocols for the understanding of molecular design, synthesis, and structure-property relationship of OEGylated and conjugated carbazole dendrons and dendrimers. In this design, the use of oligo(ethylene glycol) (OEG) allows for the fabrication of biocompatible materials and imparts hydrophilicity on the structure while the carbazole functionality allows the cross-linking of these designer molecules. Such fine-tuning of macromolecular structures leading to the fabrication of anti-biofouling thin films, nanostructuring at the air-water interface, and assembly into supramolecular superstructures are considered in this dissertation. Chapter 2 details the synthesis, characterization, and electrochemical cross-linking of OEGylated linear dendrons and "Janus-type" dendrimers. Cross-linking the carbazole moieties enables the deposition of these films on Au, indium tin oxide-coated glass, and doped silicon through cyclic voltammetry and provides films with secondary level of organization imparted by the inter- and intra-molecular interaction among the carbazole units. Chapter 3 describes the fabrication of nonspecific protein adsorption resistant surfaces through electrochemical grafting of three different dendrons on SAM carbazole-coated gold substrates. The predictable shape of each dendron and the ability to cross-link the carbazole units have enabled parametrization of OEG conformation and density on these interfaces. Chapter 4 demonstrates the fundamental architectural requirements for obtaining stable films with OEGylated linear dendron molecules providing a new architectural design of nanostructuring

  10. 食油假单胞菌DT4菌株对四氢呋喃(THF)的降解特性%Characteristics of Tetrahydrofuran Degradation by Pseudomonas oleovorans DT4

    Institute of Scientific and Technical Information of China (English)

    周玉央; 陈东之; 金小君; 陈建孟; 何杰

    2011-01-01

    对某医药厂废水池的活性污泥进行长期驯化,分离筛选到1株在好氧条件下能以四氢呋喃(tetrahydrofuran,THF)为唯一碳源和能源生长的食油假单胞菌DT4(Pseudomonas oleovorans DT4).研究发现在初始pH值7.2、温度30℃、初始菌体浓度3.2 mg/L的条件下,P.oleovorans DT4能够于14 h内将5 mmol/L THF完全降解,菌体浓度达到188.6 mg/L.另外,在THF完全降解后1 h,最终溶液中总有机碳及无机碳浓度分别达到0 mg/L和46 mg/L,且培养基的pH值降至6.54,呈弱酸性,说明P.oleovorans DT4降解THF是一个彻底矿化的过程.通过摇瓶实验考察了温度、pH、供氧方式、金属离子等因素对菌株DT4降解THF性能的影响,获得其较适宜的生长和降解条件为:温度37℃、pH值7.5,自然转动供氧状态适宜菌体生长及对THF的降解,最适Mg2+和Ca2+浓度分别为0.80 mmol/L和0.20 mmol/L.研究成果对高效处理环境中的THF污染具有重要的应用价值.%A tetrahydrofuran (THF)-degrading strain Pseudomonas oleovorans DT4 was isolated from the activated sludge of a pharmaceutical plant. P. oleovorans DT4 was able to utilize THF as the sole carbon and energy source under aerobic condition. 5 mmol/L of THF could be completely degraded by 3.2 mg/L inoculums of P. oleovorans DT4 in 14 h at pH 7.2 and 30℃ , with the cells concentration increasing to 188. 6 mg/L. After the complete consumption of THF, no TOC could be detected but IC reached the stable value of about 46 mg/L, with pH decreasing to 6. 54, which indicated that the substance was totally mineralized by P. oleovorans DT4. The optimum conditions for THF biodegradation in shaking flasks were pH 7.5 and temperature 37℃ , respectively. Results from the oxygen control experiments revealed that the oxygen supply by shaking was the satisfactory growth condition. Additionally, as the important elements for DT4, Mg2+ and Ca2+ at concentrations of 0. 80 mmol/L and 0. 20 mmol/L, respectively, were

  11. 铜绿假单胞菌NY3所产表面活性剂对原油降解的影响%Effects of rhamnolipid on oil degradation by Pseudomonas aeruginosa strain NY3

    Institute of Scientific and Technical Information of China (English)

    常虹; 蒋欣; 聂麦茜; 葛碧洲; 刘超; 杨琴; 周立辉; 樊晓宇; 孙超; 韦绒绒

    2013-01-01

    铜绿假单胞菌NY3是从石油污染土壤中分离出的一株能快速代谢疏水性化合物的菌种.研究了该菌产表面活性剂及对原油降解的作用.实验表明,在敞开体系中,投加82 mg/L NY3菌产的鼠李糖脂,240 h能使NY3对原油的降解率提高50%.投加甘油使NY3产鼠李糖脂与降解原油同步进行,与投加鼠李糖脂对原油降解的促进作用相近.投加9%甘油使NY3在168 h对原油的降解率提高43%.NY3菌能同时降解原油中的直链烷烃及菲(Pr)和芘(Ph)等多环芳烃.在敞开体系中用少量甘油使产鼠李糖脂和降解原油同步进行,节约处理费用.研究结果为NY3菌株在露天石油污染环境修复中的应用奠定了基础.%Pseudomonas aeruginosa NY3 , being able to metabolize hydrophobic compounds, was isolated from petroleum-contaminated soil samples. Effects of the rhamnolipid and its production on crude oil degradation by NY3 strain were discussed. The results showed that the rhamnolipid produced by NY3 strain could enhance crude oil biodegradation. Comparing with the controls, oil removal rate within 240 h enhanced 50% with 82 mg/ L rhamnolipid. Adding glycerol in NY3 degrading systems, the degradation of crude oil and the rhamnolipid production took place simultaneously, the instantly produced rhamnolipid also accelerated oil metabolism. Adding 9‰ glycerol, the crude oil removal rate by NY3 improved about 43% within 168 h. Phenanthrene (Ph) and py-rene ( Pr) containing in the crude oil could also be removed. The cost of the remediation of contaminated water body by NY3 strain can be decreased by using small amount of glycerol, instead of using rhamnolipid directly. The above results lay a foundation for NY3 strain applying to oil-spill clean-up.

  12. 门多萨假单胞菌DS04-T对Poly(3HB-co-4HB)的降解研究%Degradation of Poly(3HB-co-4HB) by pseudomonas mendocina DS04-T

    Institute of Scientific and Technical Information of China (English)

    李琳琳; 高佳; 杨翔华; 王战勇

    2012-01-01

    考察了门多萨假单胞菌DS04-T对Poly(3HB-co-4 HB)的降解行为.以Poly(3HB-co4HB)为唯一碳源,分别考察培养时间、培养温度、摇床转速、装液量、培养基起始pH值、接种量等因素对降解行为的影响.结合正交试验优化获得了菌株的最佳产酶条件:培养时间为28 h,培养温度为30℃,培养基初始pH值为7.3,摇床转速为150 r/min,培养基装液量为120mL(250mL三角瓶),接种量为1.5%(体积分数),此条件下菌株对Poly(3HB-co-4HB)的降解酶活力可达(26.2±0.7)U·mL-1.%The degradation of Poly(3HB-co-4HB) by pseudomonas mendocina DS04-T was studied. Poly(3HB-co-4HB) was used as the sole carbon source of culture medium. The influence of cultivation time, cultivation temperature, shaking revolution, liquid medium volume, initial pH and inoculation content were studied. Combining single factor test and orthogonal test, the optimal degrading enzyme production conditions were chosen as follows: cultivation time is 28 h, cultivation temperature is 30 C, shaking revolution is 150 r/min, initial pH is 7. 3, culture medium volume is 120 mL and inoculation content is 1. 5% (V/V). Under the optimized condition, the degradation enzyme activity reaches (26. 2 + 0. 7) U · mL-1.

  13. Pseudomonas Lipopeptide Biosurfactants

    DEFF Research Database (Denmark)

    Bonnichsen, Lise

    of the Pseudomonas lipopeptides belonging to different structural groups on important biodegradation parameters, mainly; solubilization and emulsification of hydrophobic pollutants (alkanes and PAHs) and increase of cell surface hydrophobicity of bacterial degraders. Ultimately, it was tested if these parameters led......Pseudomonas lipopetide biosurfactants are amphiphilic molecules with a broad range of natural functions. Due to their surface active properties, it has been suggested that Pseudomonas lipopetides potentially play a role in biodegradation of hydrophobic compounds and have essential functions...... in biofilm formation, however, detailed studies of these roles have not yet been carried out. The overall aim of this PhD project was therefore to elucidate in more depth the roles played by Pseudomonas lipopetides in pollutant biodegradation and biofilm formation. This study investigated the effect...

  14. Carbazole-containing light- emitting polymers: Properties of excited states

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A series of light-emitting conjugated polymers alternatively involving carbazole and bivinylene arylene moieties in the main chain were synthesized via Wittig-Horner type copolymerization. The photoinduced charge transfer process relating to these polymers was investigated by using the technique of fluorescence spectroscopy. The interaction between excited copolymers and C60 in benzene solution was studied. The fluorescence quenching can be well described by the "sphere-of-action" mechanism. It is believed that two basic steps are involved in the quenching process, i.e. the diffusion of excitation within the conjugated polymers and the dissociation of the exctions trapped by fullerene. The radius of the sphere-of-action can be related to the excitation diffusion length, which depends on the lifetime of the exciton. The dynamic fluorescence quenching of the copolymers by another quencher, 1,4-dicyanobenzene (DCB) was also surveyed. Copolymers with different chain conformations show different temperature effects in the dynamic quenching. A planar conformation is beneficial for the quenching via bimolecular collision.

  15. 2,7-Bis(2-nitrophenyl-9-octyl-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Norma Wrobel

    2012-04-01

    Full Text Available The title compound, C32H31N3O4, was obtained in a Suzuki coupling of carbazole diboronic acid and bromonitrobenzene. In the crystal, the molecule adopts a non-symmetric conformation. The carbazole ring system is approximately planar [maximum deviation from the least-squares plane = 0.039 (2 Å]. The planes of the carbazole unit and the benzene rings subtend dihedral angles of 48.42 (7 and 41.81 (6°. The dihedral angles between the planes of the nitrophenyl rings and the nitro groups are 44.34 (19 and 61.64 (15°. The crystal is built from two strands of parallel molecules with interdigitated octyl chains. These strands are symmetry related by a twofold screw axis.

  16. Charge photogeneration and transport in side-chain carbazole polymers and co-polymers

    KAUST Repository

    Li, Huawei

    2011-07-01

    The photoconductivity, hole mobility and charge photogeneration efficiency of a series of side-chain carbazole homopolymers and copolymers (with azo side-chains) have been investigated. Cyclic voltammetry measurement of frontier orbitals energies show that the HOMO energy is determined by the nature and the position of attachment of the linker between the main chain and the carbazole, the azo-moiety being not relevant in this respect. Hole mobility is not influenced by the HOMO energy but seems to depend on the degree of conformational mobility of the side-chains, reaching values of the order of 10-3cm2V-1s-1 in the best cases. The HOMO energy is instead extremely important when considering photogeneration efficiency, that can change by 10 orders of magnitude depending on the density of the carbazole side-chains in co-polymers and on the linker nature and attachment position. © 2011 Elsevier B.V. All rights reserved.

  17. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    Science.gov (United States)

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides.

  18. Degradation of aromatics and chloroaromatics by Pseudomonas sp. strain B13: purification and characterization of 3-oxoadipate:succinyl-coenzyme A (CoA) transferase and 3-oxoadipyl-CoA thiolase.

    Science.gov (United States)

    Kaschabek, Stefan R; Kuhn, Bernd; Müller, Dagmar; Schmidt, Eberhard; Reineke, Walter

    2002-01-01

    The degradation of 3-oxoadipate in Pseudomonas sp. strain B13 was investigated and was shown to proceed through 3-oxoadipyl-coenzyme A (CoA) to give acetyl-CoA and succinyl-CoA. 3-Oxoadipate:succinyl-CoA transferase of strain B13 was purified by heat treatment and chromatography on phenyl-Sepharose, Mono-Q, and Superose 6 gels. Estimation of the native molecular mass gave a value of 115,000 +/- 5,000 Da with a Superose 12 column. Polyacrylamide gel electrophoresis under denaturing conditions resulted in two distinct bands of equal intensities. The subunit A and B values were 32,900 and 27,000 Da. Therefore it can be assumed that the enzyme is a heterotetramer of the type A2B2 with a molecular mass of 120,000 Da. The N-terminal amino acid sequences of both subunits are as follows: subunit A, AELLTLREAVERFVNDGTVALEGFTHLIPT; subunit B, SAYSTNEMMTVAAARRLKNGAVVFV. The pH optimum was 8.4. Km values were 0.4 and 0.2 mM for 3-oxoadipate and succinyl-CoA, respectively. Reversibility of the reaction with succinate was shown. The transferase of strain B13 failed to convert 2-chloro- and 2-methyl-3-oxoadipate. Some activity was observed with 4-methyl-3-oxoadipate. Even 2-oxoadipate and 3-oxoglutarate were shown to function as poor substrates of the transferase. 3-oxoadipyl-CoA thiolase was purified by chromatography on DEAE-Sepharose, blue 3GA, and reactive brown-agarose. Estimation of the native molecular mass gave 162,000 +/- 5,000 Da with a Superose 6 column. The molecular mass of the subunit of the denatured protein, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was 42 kDa. On the basis of these results, 3-oxoadipyl-CoA thiolase should be a tetramer of the type A4. The N-terminal amino acid sequence of 3-oxoadipyl-CoA thiolase was determined to be SREVYI-DAVRTPIGRFG. The pH optimum was 7.8. Km values were 0.15 and 0.01 mM for 3-oxoadipyl-CoA and CoA, respectively. Sequence analysis of the thiolase terminus revealed high percentages of identity

  19. A New Maleamide Bridged Carbazole Chromogenic-sensor Based on Proton Transfer Signaling Mode

    Institute of Scientific and Technical Information of China (English)

    WANG Yue-hong; LIN Hai; SHAO Jie; LIN Hua-kuan

    2008-01-01

    A Maleamide bridged carbazole receptor was designed and synthesized, the interactions between the receptor and anions, such as Ac-, H2PO4-, OH-, F-, Cl-, Br- and I- in DMSO were investigated by UV-Vis spectroscopy and 1H NMR titration. The results of UV-Vis spectral studies indicate that interactions existed between receptor and anions, which induced remarkable color changes. The 1H NMR titration indicated amide moiety of the receptor was deprontonated first when a small quantity of anions such as Ac-, H2PO4-, F- were added; however, the carbazole N-H was gradually deprontonated upon the addition of anions.

  20. Effect of air annealing on the optical electrical and structural properties of carbazole thin films

    Energy Technology Data Exchange (ETDEWEB)

    Pisharady, Sreejith K. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India)]. E-mail: skpishar@yahoo.co.in; Menon, C.S. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India); Sudarshana Kumar, C. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India); Gopinathan, T.G. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala 656560 (India)

    2006-11-10

    Thin films of carbazole films have been prepared using vacuum sublimation technique. Post-evaporation annealing is done for various periods of time. The optical absorption spectrum is recorded and the band gap is calculated from the observed spectrum. The current-voltage characteristics are studied for the sandwiched structure of carbazole thin films with silver electrodes. From the J-V characteristics trap density and number of thermally generated charge carriers are determined. Their structure and grain size have been determined from the X-ray diffraction studies.

  1. Carotenoids play a positive role in the degradation of heterocycles by Sphingobium yanoikuyae.

    Directory of Open Access Journals (Sweden)

    Xiaorui Liu

    Full Text Available BACKGROUND: Microbial oxidative degradation is a potential way of removing pollutants such as heterocycles from the environment. During this process, reactive oxygen species or other oxidants are inevitably produced, and may cause damage to DNA, proteins, and membranes, thereby decreasing the degradation rate. Carotenoids can serve as membrane-integrated antioxidants, protecting cells from oxidative stress. FINDINGS: Several genes involved in the carotenoid biosynthetic pathway were cloned and characterized from a carbazole-degrading bacterium Sphingobium yanoikuyae XLDN2-5. In addition, a yellow-pigmented carotenoid synthesized by strain XLDN2-5 was identified as zeaxanthin that was synthesized from β-carotene through β-cryptoxanthin. The amounts of zeaxanthin and hydrogen peroxide produced were significantly and simultaneously enhanced during the biodegradation of heterocycles (carbazole < carbazole + benzothiophene < carbazole + dibenzothiophene. These higher production levels were consistent with the transcriptional increase of the gene encoding phytoene desaturase, one of the key enzymes for carotenoid biosynthesis. CONCLUSIONS/SIGNIFICANCE: Sphingobium yanoikuyae XLDN2-5 can enhance the synthesis of zeaxanthin, one of the carotenoids, which may modulate membrane fluidity and defense against intracellular oxidative stress. To our knowledge, this is the first report on the positive role of carotenoids in the biodegradation of heterocycles, while elucidating the carotenoid biosynthetic pathway in the Sphingobium genus.

  2. On the acidic metabolite characterization and degradation process of the phenanthrene by Pseudomonas aeruginosa NY3%铜绿假单胞菌降解菲的产物鉴定及代谢过程

    Institute of Scientific and Technical Information of China (English)

    沈小娟; 聂麦茜; 葛碧洲; 樊瑜; 王菲; 常虹

    2012-01-01

    This paper deals with a study on the acidic metabolite characterization and degradation process of the phenanthrene by means of Pseudomonas aeruginosa NY3. As is known, though there has been a lot of articles published on the study of metabolites, yet little has been reported on the biodegradation pathways of polycyclic aromatic hydrocarbons by pseudomonas aeruginosa. Here in this paper we would like to report the typical acidic metabolites of phenanthrene and its degrading pathway by P. aeruginosa NY3, which can help to metabolize hydrophobic compounds quickly. P. aeruginosa NY3, as a matter of fact, could grow on the phenanthrene well and its metabolites such as a-naphthol, salicylic acid, benzoic acid in regard with its sole carbon source and energy. GC ~ MS data indicate that it is possible to find five major metabolites of phenanthrene as the bacteria grow. They are 1-hydroxy-2-naphthoic acid, 2-hydroxy-2-carboxylic acid, a-naphthol, o-hydroxyphenyl carbonyl acid, salicylic acid, and benzoic acid. Based on the analysis of metabolites, the biodegradation pathway can be deduced - First of all, the phenanthrene can be made transformed into l-hydroxy-2-naphthoic acid after a series of oxidative metabolism steps by P. aeruginosa NY3, and later into a-naphthol through decavboxylation. Other metabolites that can be transformed from phenanthrene into l-hydroxy-2-naphthoic acid can be metabolized so fast that it won' t be possible to be found in our experiments, though it would be possible to find one-aromatic-ring metabolites like o-hydroxyphenyl carbonyl acid, salicylic acid, benzoic acid were detected was the evidence of further transformation of a-naphthol. However, it wouldn't be possible to find dihydroxy-naphthalene, dihydroxybenzene and other polyphenols could as the metabolites of phenanthrene by pseudomonas aeruginosa NY3, while there were greater amount of metabolites which can be characterized as ortho-hydroxyl carboxyl compounds, such as 1-hydroxy-2-naph

  3. 75 FR 34699 - Carbazole Violet Pigment 23 from India: Rescission of Countervailing Duty Administrative Review

    Science.gov (United States)

    2010-06-18

    ... International Trade Administration Carbazole Violet Pigment 23 from India: Rescission of Countervailing Duty... 23(CVP-23) from India. See Antidumping or Countervailing Duty Order, Finding, or Suspended... countervailing duty order on CVP-23 from India for the period January 1, 2008 through December 31, 2008. In...

  4. Controlled electropolymerisation of a carbazole-functionalised iron porphyrin electrocatalyst for CO2 reduction

    DEFF Research Database (Denmark)

    Hu, Xinming; Salmi, Zakaria; Lillethorup, Mie;

    2016-01-01

    Using a one-step electropolymerisation procedure, CO2 absorbing microporous carbazole-functionalised films of iron porphyrins are prepared in a controlled manner. The electrocatalytic reduction of CO2 for these films is investigated to elucidate their efficiency and the origin of their ultimate...

  5. A novel synthesis of 4-toluene 9H-carbazole-9-carbodithioate, electropolymerization and impedance study

    Directory of Open Access Journals (Sweden)

    M. Ates

    2014-07-01

    Full Text Available A novel synthesis of 4-toluene 9H-carbazole-9-carbodithioate (TCzC was chemically synthesized and characterized by Fourier Transform Infrared (FTIR, proton nuclear magnetic resonance (1H-NMR, and carbon nuclear magnetic resonance (13C-NMR spectroscopies. Specific (Csp and double layer capacitances (Cdl of the electro-coated poly(carbazole and poly(TCzC films were obtained on glassy carbon electrode (GCE by impedimetric method with DC potential from –0.1 to +1.0 V by increasing potential of 0.2 V. The polymers were characterized by Cyclic voltammetry (CV, Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR, Atomic force microscopy (AFM, and Electrochemical impedance spectroscopy (EIS. The use of additional variable (DC potential helped to disambiguate the equivalent circuit model of R(C(R(Q(RW(CR. Simulation results were compared with experimental data. In this study, substituted group effects of CS2 and tosyl on carbazole polymer were investigated by EIS technique. CS2 group together with tosyl group in the structure of carbazole decreased the specific capacitance value (Csp = 0.43 mF•cm–2 compared to PCz (Csp = 1.44 mF•cm–2. Electropolymerization formation was seriously affected by substituted groups of CS2 and tosyl on conjugation system because of the electron donor and acceptor ability.

  6. The binding modes of carbazole derivatives with telomere G-quadruplex

    Science.gov (United States)

    Zhang, Xiu-feng; Zhang, Hui-juan; Xiang, Jun-feng; Li, Qian; Yang, Qian-fan; Shang, Qian; Zhang, Yan-xia; Tang, Ya-lin

    2010-10-01

    It is reported that carbazole derivatives can stabilize G-quadruplex DNA structure formed by human telomeric sequence, and therefore, they have the potential to serve as anti-cancer agents. In this present study, in order to further explore the binding mode between carbazole derivatives and G-quadruplex formed by human telomeric sequence, two carbazole iodides (BMVEC, MVEC) molecules were synthesized and used to investigate the interaction with the human telomeric parallel and antiparallel G-quadruplex structures by NMR, CD and molecular modeling study. Interestingly, it is the pivotal the cationic charge pendant groups of pyridinium rings of carbazole that plays an essential role in the stabilizing and binding mode of the human telomeric sequences G-quadruplex structure. It was found that BMVEC with two cationic charge pendant groups of pyridinium rings of 9-ethylcarbazole cannot only stabilize parallel G-quadruple of Hum6 by groove binding and G-tetrad stacking modes and antiparallel G-quadruplex of Hum22 by groove binding, but also induce the formation of mixed G-quadruplex of Hum22. While MVEC with one cationic charge pendant groups of pyridinium ring only can bind with the parallel G-quadruplex of Hum6 by the stacking onto the G4 G-tetrad and could not interact with the G-quadruplex of Hum22.

  7. 75 FR 29718 - Carbazole Violet Pigment 23 From India and the People's Republic of China: Continuation of...

    Science.gov (United States)

    2010-05-27

    ... of Sales at Less Than Fair Value and Antidumping Duty Order: Carbazole Violet Pigment 23 From India...-proprietary information. In this case, the brackets are simply part of the chemical nomenclature....

  8. Cu-catalyzed arylation of the amino group in the indazole ring: regioselective synthesis of pyrazolo-carbazoles.

    Science.gov (United States)

    Anil Kumar, K; Kannaboina, Prakash; Dhaked, Devendra K; Vishwakarma, Ram A; Bharatam, Prasad V; Das, Parthasarathi

    2015-02-07

    Cu(II)-catalyzed cross-coupling of various aryl boronic acids with 5 and 6-amino indazoles has resulted in (arylamino)-indazoles. These (arylamino)-indazoles have been utilized in synthesizing medicinally important pyrazole-fused carbazoles via Pd(II)-catalyzed cross-dehydrogenative coupling (CDC). This combined N-arylation/C-H arylation strategy has been successfully applied to the regioselective synthesis of polyheterocycles 3,6-dihydropyrazolo[3,4-c]carbazoles and 1,6-dihydro pyrazolo[4,3-c]carbazoles. Quantum chemical analysis has been carried out to understand the regioselectivity and to trace the potential energy surface of the entire reaction upon 5-N-aryl-indazole conversion to the corresponding carbazole.

  9. Synthesis of Dendrimer Containing Carbazole Unit as a Core Chromophore

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Choul; Lee, Jae Wook [Dong-A Univ., Busan (Korea, Republic of); Jin, Sungho [Pusan National Univ., Busan (Korea, Republic of)

    2012-10-15

    for the synthesis of Frechet-type dendrimers having a carbazole unit at core, which will be soluble in common organic solvents and easily spin-coated with high quality optical thin films.

  10. Pseudomonas aeruginosa in Healthcare Settings

    Science.gov (United States)

    ... Address What's this? Submit What's this? Submit Button Pseudomonas aeruginosa in Healthcare Settings Recommend on Facebook Tweet ... and/or help treat infections? What is a Pseudomonas infection? Pseudomonas infection is caused by strains of ...

  11. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Tatsuya Fukushima

    2015-08-01

    Full Text Available Liquid organic light-emitting diodes (liquid OLEDs are unique devices consisting only of liquid organic semiconductors in the active layer, and the device performances have been investigated recently. However, the device degradation, especially, the origin has been unknown. In this study, we show that material degradation occurs in liquid OLEDs, whose active layer is composed of carbazole with an ethylene glycol chain. Nuclear magnetic resonance (NMR experiments clearly exhibit that the dimerization reaction of carbazole moiety occurs in the liquid OLEDs during driving the devices. In contrast, cleavages of the ethylene glycol chain are not detected within experimental error. The dimerization reaction is considered to be related to the device degradation.

  12. Pseudomonas screening assay

    Science.gov (United States)

    Margalit, Ruth (Inventor)

    1993-01-01

    A method for the detection of Pseudomonas bacteria is described where an Azurin-specific antibody is employed for detecting the presence of Azurin in a test sample. The detection of the presence of Azurin in the sample is a conclusive indicator of the presence of the Pseudomonas bacteria since the Azurin protein is a specific marker for this bacterial strain.

  13. Biodegradation of resorcinol by Pseudomonas sp.

    Directory of Open Access Journals (Sweden)

    Nader Hajizadeh

    2016-11-01

    Full Text Available Objective: To investigate the ability of Pseudomonas sp. isolated from East Azarbaijan, Iran in bioremediation of resorcinol. Methods: Resorcinol biodegradation was evaluated using spectrophotometry and confirmed by gas chromatography-mass spectroscopy. Results: This isolate was able to remove up to 37.12% of resorcinol from contaminated water. Reusability experiments had confirmed the biodegradation process which produced seven intermediate compounds. These intermediates were characterized by gas chromatographymass spectroscopy technique. The products of resorcinol biodegradation were apparently 1, 4-cyclohexadiene, nonadecene, 2-heptadecanone, 1-isopropyl-2-methoxy-4-methylbenzene, hexadecanoic acid, 9-octadecenoic acid, phenol and 5-methyl-2-(1-methylethyl. Conclusions: The findings revealed that Pseudomonas sp. is able to degrade resorcinol. Because of being an indigenous organism, this isolate is more compatible with the climate of the northwest region of Iran and possibly will be used for degradation of other similar aromatic compounds.

  14. Biodegradation of resorcinol byPseudomonas sp.

    Institute of Scientific and Technical Information of China (English)

    Nader Hajizadeh; Najibeh Shirzad; Ali Farzi; Mojtaba Salouti; Azra Momeni

    2016-01-01

    ABSTRACT Objective:To investigate the ability ofPseudomonas sp. isolated from East Azarbaijan, Iran in bioremediation of resorcinol. Methods: Resorcinol biodegradation was evaluated using spectrophotometry and confirmed by gas chromatography-mass spectroscopy. Results:This isolate was able to remove up to 37.12% of resorcinol from contaminated water. Reusability experiments had confirmed the biodegradation process which produced seven intermediate compounds. These intermediates were characterized by gas chromatography-mass spectroscopy technique. The products of resorcinol biodegradation were apparently 1, 4-cyclohexadiene, nonadecene, 2-heptadecanone, 1-isopropyl-2-methoxy-4-methylbenzene, hexadecanoic acid, 9-octadecenoic acid, phenol and 5-methyl-2-(1-methylethyl). Conclusions: The findings revealed thatPseudomonas sp. is able to degrade resorcinol. Because of being an indigenous organism, this isolate is more compatible with the climate of the northwest region of Iran and possibly will be used for degradation of other similar aromatic compounds.

  15. Monocyte Profiles in Critically Ill Patients With Pseudomonas Aeruginosa Sepsis

    Science.gov (United States)

    2017-02-02

    Pseudomonas Infections; Pseudomonas Septicemia; Pseudomonas; Pneumonia; Pseudomonal Bacteraemia; Pseudomonas Urinary Tract Infection; Pseudomonas Gastrointestinal Tract Infection; Sepsis; Sepsis, Severe; Critically Ill

  16. 3-Bromomethyl-4-methoxy-2-(2-nitrophenyl-9-phenylsulfonyl-9H-carbazole

    Directory of Open Access Journals (Sweden)

    S. Gopinath

    2014-06-01

    Full Text Available In the title compound, C26H19BrN2O5S, the carbazole tricycle is essentially planar, with the largest deviation being 0.126 (3 Å for the C atom connected to the nitrophenyl group. The carbazole moiety is almost orthogonal to the benzene rings of the adjacent phenylsulfonyl and nitrophenyl groups, making dihedral angles of 85.43 (15 and 88.62 (12°, respectively. The molecular conformation is stabilized by two C—H...O hydrogen bonds involving the sulfone group, which form similar six-membered rings. In the crystal, molecules symmetrically related by a glide plane are linked in C(6 chains parallel to [001] by C—H...O hydrogen bonds formed with the participation of the nitro group. The chains are reinforced by additional C—H...π interactions.

  17. Carbazole Scaffold in Medicinal Chemistry and Natural Products: A Review from 2010-2015.

    Science.gov (United States)

    Tsutsumi, Lissa S; Gündisch, Daniela; Sun, Dianqing

    2016-01-01

    9H-carbazole is an aromatic molecule that is tricyclic in nature, with two benzene rings fused onto a 5-membered pyrrole ring. Obtained from natural sources or by synthetic routes, this scaffold has gained much interest due to its wide range of biological activity upon modifications, including antibacterial, antimalarial, anticancer, and anti-Alzheimer properties. This review reports a survey of the literature on carbazole-containing molecules and their medicinal activities from 2010 through 2015. In particular, we focus on their in vitro and in vivo activities and summarize structure-activity relationships (SAR), mechanisms of action, and/or cytotoxicity/selectivity findings when available to provide future guidance for the development of clinically useful agents from this template.

  18. Nanoscale characterization of carbazole-indole copolymers modified carbon fiber surfaces.

    Science.gov (United States)

    Sarac, A Sezai; Serantoni, Marina; Tofail, Syed A M; Cunnane, Vincent J

    2005-10-01

    Polycarbazole, carbazole and indole containing copolymers were electrochemically coated onto carbon fiber. The resulting polymers and copolymers were characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Characterization of the thin polymer films were performed on the polymer-coated surface of the carbon fiber. Therefore, the results obtained could elucidate the relationship between the initial feed monomer ratio, the resulting polymer/copolymer film morphology and the surface structure formed. The thickness increase (in diameter) was 0.3 and 0.9 microm, for two different composition of carbazole/indole on the carbon fiber. The carbon fibers coated with copolymer thin films were from 6.5 to 8.2 microm in diameter (from AFM measurement).

  19. 1H and 15N Dynamic Nuclear Polarization Studies of Carbazole

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Zhi; Solum, Mark S.; Wind, Robert A.; Nilsson, Brad L.; Peterson, Matt A.; Pugmire, Ronald J.; Grant, David M.

    2000-01-01

    15N NMR experiments, combined with dynamic nuclear polarization (DNP), are reported on carbazole doped with the stable free radical 1,3 bisdiphenylene-2 phenylally1 (BDPA). Doping shortens the nuclear relaxation times and provides paramagnetic centers that can be used to enhance the nuclear signal by means of DNP so that 15 N NMR experiments can be done in minutes. The factors were measured in a 1.4 T external field, using both unlabeled and 98% 15N labeled carbazole with doping levels varying between 0.65 and 5.0 wt % BDPA. A doping level of approximately 1 wt % produced optimal results. DNP enhancement factors of 35 and 930 were obtained for 1H and 15N, respectively making it possible to perform 15N DNP NMR experiments at the natural abundance level.

  20. Calix[3]carbazole: A C3-symmetrical receptor for barium ion

    Science.gov (United States)

    Yang, Zhaozheng; Tian, Zhangmin; Yang, Peng; Deng, Tuo; Li, Gang; Zhou, Xue; Chen, Yan; Zhao, Liang; Shen, Hongyan

    2017-03-01

    The binding ability of calix[3]carbazole (1) to metal ions has been investigated. It is found that 1 could serve as a non crown ether based, C3-symmetrical receptor for Ba2 + via the marriage of cation-π and cation-dipole interactions. FID assay further illustrates that 1 could selectively interact with Ba2 + over Pd2 +. A possible binding mechanism for [1-Ba2 +] complex is proposed.

  1. Highly Selective Fluoride Recognition by a Simple Carbazole-based Hydrozone Derivative

    Institute of Scientific and Technical Information of China (English)

    TANG Li-jun; ZHAO Guo-you; HUANG Zhen-long; WANG Nan-nan; GUO Jiao-jiao

    2013-01-01

    A simple carbazole hydrozone derivative(1) was synthesized and used as an optical probe for fluoride recognition in CH3CN.Receptor 1 exhibited colorimetric and fluorescent dual-channel response to fluoride anions.Addition of fluoride to a receptor 1 solution in CH3CN induced a distinct color change from yellow to magenta,the solution also displayed significant fluorescence blue shift.Thus receptor 1 exhibited dual-channel responses to fluoride with a high selectivity and sensitivity.

  2. Electrochemical impedance of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Ates, Murat; Uludag, Nesimi [Department of Chemistry, Faculty of Arts and Sciences, Namik Kemal University, Degirmenalti Campus, 59030, Tekirdag (Turkey); Sarac, A. Sezai, E-mail: sarac@itu.edu.tr [Department of Chemistry, Polymer Science and Technology, Istanbul Technical University, Maslak, 34469, Istanbul (Turkey)

    2011-05-16

    Research highlights: {yields} Impedance study of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber. {yields} Copolymer of 9-tosyl-9H-carbazole and pyrrole were electrocoated on carbon fiber. {yields} Impedance spectroscopy and circuit models of poly(9-tosyl-9H-carbazole-co-pyrrole). - Abstract: In this paper, copolymer of 9-tosyl-9H-carbazole (TCz) and pyrrole (Py) comonomers were electrochemically deposited onto carbon fiber micro electrode (CFME) as an active electrode material. An electrochemical impedance study on the prepared electrodes is reported. Poly(TCz-co-Py)/CFME is characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy (EIS). Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode-magnitude and Bode-phase plots. An examination is made of which equivalent circuits of R(C(R(Q(RW)))) and R(C(R(Q(RW))))(CR) used for modeling the system. The effect of monomer ratio (mole fraction, X{sub TCz} = n{sub TCz}/n{sub TCz} + n{sub Py}) on the formation of copolymer is reported in 0.1 M sodium perchlorate (NaClO{sub 4})/acetonitrile (ACN) solution. The inclusion of TCz in the copolymer structure was also confirmed by FTIR-ATR, SEM, and CV measurements. The highest low frequency capacitance (C{sub LF} = 22.7 for R(C(R(Q(RW)))) and C{sub LF} = 22.6 mF cm{sup -2} for R(C(R(Q(RW))))(CR)) were obtained for X{sub TCz} = 0.91.

  3. Bacterial Degradation of Aromatic Compounds

    Directory of Open Access Journals (Sweden)

    Qing X. Li

    2009-01-01

    Full Text Available Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms.

  4. Carbazole alkaloids from Murraya koenigii trigger apoptosis and autophagic flux inhibition in human oral squamous cell carcinoma cells.

    Science.gov (United States)

    Utaipan, Tanyarath; Athipornchai, Anan; Suksamrarn, Apichart; Jirachotikoon, Canussanun; Yuan, Xiaohong; Lertcanawanichakul, Monthon; Chunglok, Warangkana

    2017-01-01

    Carbazole alkaloids, a major constituent of Murraya koenigii (L.) Sprengel (Rutaceae), exhibit biological effects such as anticancer activity via the induction of apoptosis, and they represent candidate chemotherapeutic agents. Oral squamous cell carcinoma (OSCC) is the most prevalent cancer of the oral cavity and a growing and serious health problem worldwide. In this study, we investigated the anticancer properties and mechanisms of action of two carbazole alkaloids derived from M. koenigii leaves, mahanine and isomahanine, in the OSCC cell line CLS-354. At 15 μM, mahanine and isomahanine were cytotoxic to CLS-354 cells, triggering apoptosis via caspase-dependent and -independent mechanisms. Autophagosomes, visualised using monodansylcadaverine (MDC) labelling, were numerous in carbazole alkaloid-treated cells. Mahanine and isomahanine markedly induced the expression of the autophagosome marker microtubule-associated protein 1 light chain 3, type II (LC3B-II). Genetic and chemical inhibition of autophagy via silencing of the Autophagy protein 5 gene and exposure to bafilomycin A1 (BafA1), respectively, did not arrest carbazole alkaloid-induced apoptosis, indicating that it occurs independently of autophagic activation. Surprisingly, both carbazole alkaloids caused increased accumulation of p62/sequestosome1 (p62/SQSTM1), with coordinated expression of LC3B-II and cleaved caspase-3, suggesting inhibition of autophagic flux. Our results suggest that inhibition of autophagic flux is associated with carbazole alkaloid-induced apoptosis. Our findings provide evidence of a novel cytotoxic action of natural carbazole alkaloids and support their use as candidate chemotherapeutic agents for the treatment of OSCC.

  5. N-Alkyl Carbazole Derivatives as New Tools for Alzheimer’s Disease: Preliminary Studies

    Directory of Open Access Journals (Sweden)

    Carmela Saturnino

    2014-07-01

    Full Text Available Alzheimer’s disease (AD is a progressive and age-related neurodegenerative disorder affecting brain cells and is the most common form of “dementia”, because of the cognitive detriment which takes place. Neuronal disruption represents its major feature, due to the cytosolic accumulation of amyloid β-peptide (Aβ which leads to senile plaques formation and intracellular neurofibrillary tangles. Many studies have focused on the design and therapeutic use of new molecules able to inhibit Aβ aggregation. In this context, we evaluated the ability of two recently synthesized series of N-alkyl carbazole derivatives to increase the Aβ soluble forms, through molecular docking simulations and in vitro experiments. Our data evidenced that two carbazole derivatives, the most active, adopt distinct binding modes involving key residues for Aβ fibrillization. They exhibit a good interfering activity on Aβ aggregation in mouse (N2a cells, stably expressing wild-type human amyloid precursor protein (APP 695. These preliminary results are promising and we are confident that the N-alkyl carbazole derivatives may encourage next future studies needed for enlarging the knowledge about the AD disease approach.

  6. Synthesis and Properties of 1,8-Carbazole-Based Conjugated Copolymers

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Michinobu

    2010-07-01

    Full Text Available A new series of conjugated carbazole polymers based on the 1,8-carbazolylene unit was synthesized by the Pd-catalyzed polycondensation between the 1,8-diiodocarbazole derivative and various bifunctional counter comonomers. An alkyne spacer was found to be a key to increasing the molecular weight of the resulting polymers. All the obtained polymers showed good solubilities in the common organic solvents, and they were fully characterized by Gel permeation chromatography (GPC, and 1H NMR and infrared (IR spectroscopies. The UV-vis absorption and fluorescence spectra revealed the relationship between the chemical structure and effective conjugation length. The efficiency order of the carbazole connectivity was 2,7-carbazolylene > 1,8-carbazolylene > 3,6-carbazolylene. The electrochemical properties of these polymers suggested the relatively facile oxidation at ca. +0.5–0.7 V vs. Fc/Fc+ or a high potential as p-type semiconductors. The combination of the electrochemical oxidation potentials and the optical band gaps allowed us to estimate the HOMO and LUMO levels of the polymers. It was shown that the energy levels of the 1,8-carbazole-based conjugated polymers can be tunable by selecting the appropriate comonomer structures.

  7. Vascular barrier protective effects of 3-N- or 3-O-cinnamoyl carbazole derivatives.

    Science.gov (United States)

    Ku, Sae-Kwang; Lee, Jee-Hyun; O, Yuseok; Lee, Wonhwa; Song, Gyu-Yong; Bae, Jong-Sup

    2015-10-01

    In this Letter, we investigated the barrier protective effects of 3-N-(MeO)n-cinnamoyl carbazoles (BS 1; n=1, BS 2; n=2, BS 3; n=3) and 3-O-(MeO)3-cinnamoyl carbazole (BS 4) against high-mobility group box 1 (HMGB1)-mediated vascular disruptive responses in human umbilical vein endothelial cells (HUVECs) and in mice for the first time. Data showed that BS 2, BS 3, and BS 4, but not BS 1, inhibited HMGB1-mediated vascular disruptive responses and transendothelial migration of human neutrophils to HUVECs. BS 2, BS3, and BS 4 also suppressed HMGB1-induced hyperpermeability and leukocyte migration in mice. Interestingly, the barrier protective effects of BS 3 and BS 4 were better than those of BS 2. These results suggest that the number of methoxy groups substituted on the cinnamamide or cinnamate moiety of the 9H-3-carbazole derivative is an important pharmacophore for the barrier protective effects of these compounds.

  8. Electrochemical Polymerization of Carbazole in Acetic Acid Containing Boron Trifluoride Diethyl Etherate

    Institute of Scientific and Technical Information of China (English)

    MIAO,Hua-Ming; ZHANG,Hong-Lin; XU,Jing-Kun; FAN,Chang-Li; DONG,Bin; ZENG,Li-Qiang; ZHAO,Feng

    2008-01-01

    High-quality polycarbazole (PCz) films with an electrical conductivity of 10-2 S·cm-1 were synthesized elec-trochemically by direct anodic oxidation of carbazole in a novel mixed electrolyte of acetic acid containing 26% boron trifluoride diethyl etherate (BTDE) and 5% poly(ethylene glycol) with molar mass of 400 (by volume). The oxidation potential of carbazole in this medium was measured to be only 0.89 V vs. a saturated calomel electrode (SCE), which was much lower than that determined in acetonitrile containing 0.1mol·L-1 Bu4NBF4 (1.36 V vs. SCE). PCz films obtained from this medium showed good electrochemical behavior, good thermal stability, and were partly soluble in strong polar organic solvents such as dimethyl sulfoxide and tetrahydrofuran. The fluorescence spectra implied that PCz obtained from this medium was a good blue-light emitter. FT-IR, 1H NMR and theoretical studies showed that the polymerization of carbazole mainly occurred at the 3,6-positions. To the best of our knowledge, this is the first report on the electrosyntheses of conducting polymers in mixed electrolyte of acetic acid and BTDE.

  9. Star-shaped carbazole derivative based efficient solid-state dye sensitized solar cell

    Science.gov (United States)

    Michaleviciute, Asta; Degbia, Martial; Tomkeviciene, Ausra; Schmaltz, Bruno; Gurskyte, Egle; Grazulevicius, Juozas Vidas; Bouclé, Johan; Tran-Van, François

    2014-05-01

    Two new star-shaped carbazole molecules, including tri(9-(methoxyphenyl)carbazol-3-yl)amine named TMPCA having molecular glasses properties and hole transport properties were synthesized. Their thermal, optical, photophysical and electrochemical properties were studied. The carbazole based molecules exhibit high thermal stability with 5% weight loss temperatures over 480 °C with higher glass temperature transitions 164-175 °C than the classical spiro-OMeTAD reference molecule. Their optical band gaps (2.76 eV) are low enough not to hinder neither the absorption of the indoline sensitizer (D102) nor its photoexcitation and charge transfer. Solid state ionization potential (IPs) of TMPCA is well adapted to that of D102 and ensure a driving force ΔrG >0.2 eV for an efficient transfer and regeneration of the photo-oxidized dye. Solid-state dye sensitized solar cells ITO/TiO2/D102/T4MPCA/Au showed a power conversion efficiency of 2.23% with Jsc of 8.85 mA cm-2 under standard AM 1.5 simulated solar irradiation.

  10. Color-Tunable Solid-State Fluorescence Emission from Carbazole-Based BODIPYs.

    Science.gov (United States)

    Maeda, Chihiro; Todaka, Takumi; Ueda, Tomomi; Ema, Tadashi

    2016-05-23

    Several carbazole-based boron dipyrromethene (BODIPY) dyes were synthesized by organometallic approaches. Thiazole, benzothiazole, imidazole, benzimidazole, triazole, and indolone substituents were introduced at the 1-position of the carbazole moiety, and boron complexation of each dipyrrin generated the corresponding compounds 1, 2 a, and 3-6. The properties of these products were investigated by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, X-ray crystallography, and DFT calculations. These compounds exhibited large Stokes shifts, and compounds 1, 2 a, and 3-5 fluoresced both in solution and in the solid state. Complex 2 a showed the highest fluorescence quantum yield (ΦF ) in the solid state, therefore boron complexes of the carbazole-benzothiazole hybrids 2 b-f, which had several different substituents, were prepared and the effects of the substituents on the photophysical properties of the compounds were examined. The fluorescence properties showed good correlation with the results of crystal-packing analyses, and the dyes exhibited color-tunable solid-state fluorescence.

  11. Carbazole-based sensitizers for potential application to dye sensitized solar cells

    Indian Academy of Sciences (India)

    Naresh Duvva; Ravi Kumar Kanaparthi; Jaipal Kandhadi; Gabriele Marotta; Paolo Salvatori; Filippo De Angelis; Lingamallu Giribabu

    2015-03-01

    Two push-pull molecules employing carbazole and alkyl thiophene (CAR-THIOHX) or carbazole and triphenylamine (CAR-TPA) as donor moieties, with the cyanoacrylic group as the acceptor, have been designed and synthesized by simple organic transformations. Photophysical and electrochemical studies revealed the potential of these two systems in dye sensitized solar cells (DSSC). Under standard irradiation conditions, CAR-TPA and CAR-THIOHX exhibited 2.12 and 1.83% of overall power conversion efficiencies respectively. The moderate photovoltaic efficiency of the sensitizers has been attributed to the poor light absorption of the sensitizers in the visible region. Density functional theory (DFT) calculations have shown a strong intramolecular charge transfer character, with the HOMOs of both the sensitizers exclusively localized on the corresponding donor moieties and LUMOs on the cyanoacrylic acid acceptor. On the other hand, the calculated high dihedral angle between the carbazole donor and the phenyl bridge for these sensitizers impedes the conjugation along the dyes backbone, and thus leads to less extended and intense absorption spectra in the visible region.

  12. Enzymolysis of aflatoxin B1 by Pseudomonas stutzeri F4 and analysis of the degrading products%施氏假单胞菌F4对黄曲霉毒素B1的酶解作用及其降解产物的初步分析

    Institute of Scientific and Technical Information of China (English)

    李文明; 杨文华; 李海星; 刘晓华; 曹郁生

    2013-01-01

    施氏假单胞菌F4能高效降解黄曲霉毒素B1(aflatoxin B1,AFB1).研究了F4的AFB1降解活性、降解动力学以及蛋白酶K和SDS对其降解性能的影响.F4细胞悬液与毒素共培养72 h后降解率达80.03%;蛋白酶K处理对降解率没有影响,SDS处理的细胞悬液基本丧失了降解活性.不同时间点的降解液上清液仍能有效降解残留AFB1,其中以60 h的降解液上清液活性较好,与残留AFB1继续作用48 h后降解率达84.30%;而经蛋白酶K处理后降解率仅为45.42%.低浓度AFB1诱导对菌体的降解活性没有影响.上述结果提示,F4通过胞内酶作用降解AFB1.高效液相色谱对产物分析表明,F4可将AFB1酶解为至少2种产物.%Pseudomonas stutzeri F4 is capable of removing aflatoxin B1 efficiently.The properties and the kinetics of aflatoxin B1 hydrolyzed by F4, and the influence of proteinase K and SDS on its degradation performance were investigated.After 72 h of cultivation, 80.03% of AFB1 was degraded by F4 cell suspension.Proteinase K had no affects on its degradation efficiency, while the degradation ability almost lost by SDS treatment.In addition, the cell-free supernatant of the degradation solution taken from different time also had the detoxification activity, and in which 60 h sample showed a better activity (84.30% AFB, was degraded after continuous cultivation for 48 h).When the supernatant treated with proteinase K, the degradation efficiency was decreased to 45.42%.Low concentration of AFB1 induction had no effect on the degradation activity.These results indicated that a F4 intracellular enzyme was responsible for the degradation of AFB1.Meanwhile, HPLC chromatograms demonstrated that AFB1 was degraded to at least two products.

  13. 3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

    Science.gov (United States)

    Li, Wei; Otsuka, Munechika; Wang, Yang; Mori, Takehiko

    2016-01-01

    Summary The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic–organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility. PMID:27559390

  14. 40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS; exemptions from the requirement of a tolerance... Tolerances § 180.1114 Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas...

  15. Photochemical Synthesis of Complex Carbazoles: Evaluation of Electronic Effects in Both UV- and Visible-Light Methods in Continuous Flow.

    Science.gov (United States)

    Hernandez-Perez, Augusto C; Caron, Antoine; Collins, Shawn K

    2015-11-09

    An evaluation of both a visible-light- and UV-light-mediated synthesis of carbazoles from various triarylamines with differing electronic properties under continuous-flow conditions has been conducted. In general, triarylamines bearing electron-rich groups tend to produce higher yields than triarylamines possessing electron-withdrawing groups. The incorporation of nitrogen-based heterocycles, as well as halogen-containing arenes in carbazole skeletons, was well tolerated, and often synthetically useful complementarity was observed between the UV-light and visible-light (photoredox) methods.

  16. Synthesis and characterization of novel star-shaped pyridine cored compounds with alternating carbazole and triphenylamine moieties

    Institute of Scientific and Technical Information of China (English)

    Ji Bing Yuan; Zhi Guo Zhang; Louis Man Leung; Ke Li Zhang

    2008-01-01

    Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-visabsorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.

  17. Carbazoles, benzocarbazoles et dibenzocarbazoles des pétroles et de produits pétroliers Carbazoles, Benzocarbazoles and Dibenzocarbazoles from Oil and Petroleum Products

    Directory of Open Access Journals (Sweden)

    Arpino P.

    2006-11-01

    Full Text Available On décrit dans cet article les principales techniques d'analyse des dérivés du pyrrole dans les pétroles et les produits pétroliers et on présente les principaux résultats obtenus. La méthode la plus efficace consiste en une concentration de ces composés par chromatographie liquide; l'identification des principaux composés individuels se fait par chromatographie gazeuse et son couplage avec la spectrométrie de masse. On a essentiellement identifié ou caractérisé : le carbazole et certains de ses dérivés alkylés, les dibenzo(a-, -(b- et -(ccarbazoles et certains de leurs dérivés alkylés, certains dibenzocarbazoles. D'un point de vue géochimique, il semble évident que ces composés ne sont pas des molécules fossiles, Il est également apparu des différences de comportement de ces composés les uns par rapport aux autres vis-à-vis de l'hydrotraitement catalytique. This article describes the leading techniques for analyzing derivatives from pyrrole in oil and petroleum products. The main results obtained are described. The most effective method consists of a concentration of these compounds by liquid chromatography. The main individual components are identified by gas chromatography and its coupling with mass spectrometry. The principal compounds identified or characterized were carbazole and some of its alkylated derivatives, dibenzo(a-, -(b- and -(ccarbazoles and some of their alkylated derivates, and various dibenzocarbazoles. From the geochernical standpoint, it seems obvious that these compounds are not fossil molecules. Differences in behavior were also found for these compounds in relation to others with regard to catalytic hydrotreatment.

  18. The thermodynamic properties of 2-aminobiphenyl (an intermediate in the carbazole/hydrogen reaction network)

    Energy Technology Data Exchange (ETDEWEB)

    Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A.

    1990-12-01

    Catalytic hydrodenitrogenation (HDN) is a key step in upgrading processes for conversion of heavy petroleum, shale oil, tar sands, and the products of the liquefaction of coal to economically viable products. This research program provides accurate experimental thermochemical and thermophysical properties for key organic nitrogen-containing compounds present in the range of alternative feedstocks, and applies the experimental information to thermodynamic analyses of key HDN reaction networks. This report is the first in a series that will lead to an analysis of a three-ring HDN system; the carbazole/hydrogen reaction network. 2-Aminobiphenyl is the initial intermediate in the HDN pathway for carbazole, which consumes the least hydrogen possible. Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2-aminobiphenyl are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c). Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for selected temperatures between 298.15 K and 820 K. The critical temperature and critical density were determined for 2-aminobiphenyl with the d.s.c., and the critical pressure was derived. The Gibbs energies of formation are used in thermodynamic calculations to compare the feasibility of the initial hydrogenolysis step in the carbazole/H{sub 2} network with that of its hydrocarbon and oxygen-containing analogous; i.e., fluorene/H{sub 2} and dibenzofuran/H{sub 2}. Results of the thermodynamic calculations are compared with those of batch-reaction studies reported in the literature. 57 refs., 8 figs., 18 tabs.

  19. Structural insight into the substrate- and dioxygen-binding manner in the catalytic cycle of rieske nonheme iron oxygenase system, carbazole 1,9a-dioxygenase

    Directory of Open Access Journals (Sweden)

    Ashikawa Yuji

    2012-06-01

    Full Text Available Abstract Background Dihydroxylation of tandemly linked aromatic carbons in a cis-configuration, catalyzed by multicomponent oxygenase systems known as Rieske nonheme iron oxygenase systems (ROs, often constitute the initial step of aerobic degradation pathways for various aromatic compounds. Because such RO reactions inherently govern whether downstream degradation processes occur, novel oxygenation mechanisms involving oxygenase components of ROs (RO-Os is of great interest. Despite substantial progress in structural and physicochemical analyses, no consensus exists on the chemical steps in the catalytic cycles of ROs. Thus, determining whether conformational changes at the active site of RO-O occur by substrate and/or oxygen binding is important. Carbazole 1,9a-dioxygenase (CARDO, a RO member consists of catalytic terminal oxygenase (CARDO-O, ferredoxin (CARDO-F, and ferredoxin reductase. We have succeeded in determining the crystal structures of oxidized CARDO-O, oxidized CARDO-F, and both oxidized and reduced forms of the CARDO-O: CARDO-F binary complex. Results In the present study, we determined the crystal structures of the reduced carbazole (CAR-bound, dioxygen-bound, and both CAR- and dioxygen-bound CARDO-O: CARDO-F binary complex structures at 1.95, 1.85, and 2.00 Å resolution. These structures revealed the conformational changes that occur in the catalytic cycle. Structural comparison between complex structures in each step of the catalytic mechanism provides several implications, such as the order of substrate and dioxygen bindings, the iron-dioxygen species likely being Fe(III-(hydroperoxo, and the creation of room for dioxygen binding and the promotion of dioxygen binding in desirable fashion by preceding substrate binding. Conclusions The RO catalytic mechanism is proposed as follows: When the Rieske cluster is reduced, substrate binding induces several conformational changes (e.g., movements of the nonheme iron and the ligand

  20. Synthesis of two carbazole-based dyes and application of two-photon initiating polymerization

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Two carbazole-based polymerization initiators possessing blue fluorescence emission have been synthesized via Wittig reaction in the solid phase at room temperature.Two-photon excited fluorescence(TPEF) spectra for them were investigated under 800 nm fs laser pulse and two-photon absorption cross sections were determined by the Z-scan technique.Then two-photon initiating polymerization(TPIP) microfabrication experiments were successfully carried out.Three-dimensional lattice and artificial defects were gained,indicating that they were viable candidates for the two-photon polymerization initiator in practical application of microfabrication.

  1. Synthesis, measurements, and theoretical analysis of carbazole derivatives with high-triplet-energy

    Energy Technology Data Exchange (ETDEWEB)

    Li Jianli; Mi Xiaoyun; Wan Yuchun [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Si Zhenjun, E-mail: szj@cust.edu.cn [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Praha 6 16610 (Czech Republic); Sun Haiying; Duan Qian [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China); He Xingquan [School of Chemistry and Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Yan Dong; Wan Sha [School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022 (China)

    2012-05-15

    In order to obtain the blue light-emitting organic materials with high triplet state energy, two 3,5-diphenyl-4H-1,2,4-triazole (Tz) containing carbazole (Cz) derivatives of 9-(4-(3,5-diphenyl-4H-1,2,4-triazol-4-yl)phenyl)-9H-carbazole (TzCz1) and 3,6-di-tert-butyl-9-(4-(3,5-diphenyl-4H-1,2,4-triazol-4-yl)phenyl) -9H-carbazole (TzCz2) are synthesized using Cz acting as the starting material, as well as characterized by the {sup 1}H NMR spectra, ultraviolet-visible (UV-vis) absorption spectra, and the IR absorption spectra. The luminescence quantum yields (LQYs) of TzCz1 and TzCz2 are measured in CH{sub 2}Cl{sub 2} solution to be 32.1% and 47.5%, respectively. The electrochemical analysis and the photophysical measurements suggest that the triplet energy levels and the energy gaps of the highest-occupied orbital and the lowest-unoccupied orbital are 2.83 eV and 3.59 eV for TzCz1, and 2.80 eV and 3.43 eV for TzCz2. At last, the theoretical analyses of their ground state geometries and the simulated UV-vis absorption spectra are carried out at B3LYP1/6-31G Low-Asterisk level. The studies mentioned above indicate that both TzCz1 and TzCz2 are suitable for the host materials of blue light-emitting diodes. - Highlights: Black-Right-Pointing-Pointer Synthesis of two blue light-emitting Carbazole derivatives. Black-Right-Pointing-Pointer Photophysical and electrochemical properties are systematically studied. Black-Right-Pointing-Pointer Theoretical analysis of geometry of the ground states and the UV-vis absorption are performed with Firefly package. Black-Right-Pointing-Pointer The triplet energy levels are measured to be ca. 2.83 eV.

  2. Synthesis of two carbazole-based dyes and application of two-photon initiating polymerization

    Institute of Scientific and Technical Information of China (English)

    HU RenTao; LU LiangFei; RUAN BanFeng; WANG Peng; ZHANG MingLiang; ZHOU HongPing; LI ShengLi; WU JieYing; TIAN YuPeng

    2009-01-01

    Two carbazole-based polymerization initiators possessing blue fluorescence emission have been synthesized via Wittig reaction in the solid phase at room temperature.Two-photon excited fluorescence (TPEF) spectra for them were investigated under 800 nm fs laser pulse and two-photon absorption cross sections were determined by the Z-scan technique.Then two-photon initiating polymerization (TPIP) microfabrication experiments were successfully carried out.Three-dimensional lattice and artificial defects were gained,indicating that they were viable candidates for the two-photon polymerization initiator in practical application of microfabrication.

  3. Antidiarrhoeal activity of carbazole alkaloids from Murraya koenigii Spreng (Rutaceae) seeds.

    Science.gov (United States)

    Mandal, Suvra; Nayak, Anupam; Kar, Manoj; Banerjee, Samir K; Das, Ashes; Upadhyay, S N; Singh, R K; Banerji, Avijit; Banerji, Julie

    2010-01-01

    The bioassay guided fractionation of the n-hexane extract of the seeds of Murraya koenigii Spreng (Rutaceae) resulted in the isolation of three bioactive carbazole alkaloids, kurryam (I), koenimbine (II) and koenine (III). The structures of the compounds were confirmed from their (1)H-, (13)C-, and 2D-NMR spectral data. Of the three compounds (I) and (II) exhibited significant inhibitory activity against castor oil-induced diarrhoea and PGE(2)-induced enteropooling in rats. The compounds also produced a significant reduction in gastrointestinal motility in the charcoal meal test in Wistar rats.

  4. New materials based on carbazole for optoelectronic device applications:Theoretical investigation

    Institute of Scientific and Technical Information of China (English)

    K.Hasnaoui; H.Zgou; M.Hamidi; M.Bouachrine

    2008-01-01

    A quantum-chemical investigation on the structural and optoelectronic properties of two materials based on carbazole is carried out.The purpose is to display the effect of grafting the fluorine atoms on their optoelectronic and pbysico-chemical properties.In addition to solubility in the polar solvents and the modification in geometric parameters,the substitution of fluorine destabilizes the HOMO and LUMO levels,decreases the band gap energy and raises conjugation length.These properties suggest the substituted fluorine compound as a good candidate for optoelectronic applications.

  5. Miscibility and Molecular Orientation of Carbazole in Mixed Langmuir and Langrnuir-Blodgett Films

    Institute of Scientific and Technical Information of China (English)

    Md. N. Islam; D. Bhattacharjee; S. A. Hussain

    2007-01-01

    We report the miscibility and molecular orientation of carbazole (CA) molecules in the mixed Langmuir and Langmuir-Blodgett (LB) films of CA in polymethyl methacrylate (PMMA) and stearic acid (SA) matrices. The r-A isotherm confirms the formation of stable Langmuir films of CA mixed with either PMMA or SA at airwater interface. Characteristics of area per molecule versus molefraction and collapse pressure versus molefraction reveal complete demixing of CA and the matrix PMMA/SA molecules in the mixed films. Absorption spectroscopy certainly confirms the fact that CA molecules have preferred orientation on the substrate of the LB films.

  6. 3,6-Dichloro-9-(prop-2-yn-1-yl-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Joel T. Mague

    2014-01-01

    Full Text Available The tricyclic aromatic ring system of the title compound, C15H9Cl2N, is essentially planar (r.m.s. deviation = 0.002 Å. The two Cl atoms lie slightly out of the plane of the carbazole ring system, with the C—Cl bonds forming angles of 1.23 (8 and 1.14 (8° with the plane. The acetylene group has a syn orientation with respect to the ring system. In the crystal, no weak hydrogen bonds nor any π–π stacking interactions are observed.

  7. 一株假单胞菌的亚硝酸盐降解特性及其对鱼池底泥的净化作用%Nitrite degradation of a Pseudomonas sp. strain SF1 and its applicaiton in fish pond sediment

    Institute of Scientific and Technical Information of China (English)

    陈瑞芳; 徐长安; 刘丽梅; 方卫东

    2011-01-01

    从海水养殖池的底泥中筛选到一株对亚硝酸盐有强降解作用的假单胞菌(Pseudomonas sp.)SF1,在实验室条件下研究了SF1的亚硝酸盐降解特性及其对高污染鱼池底泥的净化作用。研究结果表明,SF1具有高效降解转化高浓度亚硝酸钠的能力,其适宜降解条件为:亚硝酸钠质量浓度范围为1~1000mg/L;菌种接种量为10%;中量充气发酵;发酵时间为12~36h;发酵pH值为6.5~8.0。直接接种SF1发酵液(接种量10%,菌液A值0.36)到鱼池底泥,36h后,底泥的亚硝酸盐去除率达到67%,显示了SF1对鱼%A strain of Pseudomonas sp., named as SF1, which showed high capacity of nitrite degradation, was screened from the mud of marine culturing pond. SF1 nitrite-degrading property and its application in fish pond sediment were carried out under lab environment. SF1 showed a high ability to degrade sodium nitrite at the following conditions, 1-1000 mg/L of sodium nitrite concentrate, 10% of denitrifying bacteria inoculums, median aerating during fermentation; pH ranging between 6.5-8.0, and 12-36 h of fermentation time. Introducing SF1 fermentation broth (A value 0.36) into fish pond sediment at the ratio of 10% removed 67% of nitrite after 36 h. Our results indicate that SF1 can be used to treat fish pond sediment.

  8. Regio-selective synthesis of diversely substituted benzo[a]carbazoles through Rh(iii)-catalyzed annulation of 2-arylindoles with α-diazo carbonyl compounds.

    Science.gov (United States)

    Li, Bin; Zhang, Beibei; Zhang, Xinying; Fan, Xuesen

    2017-01-19

    A novel synthetic approach toward benzo[a]carbazoles or 6-amino benzo[a]carbazoles containing an unprotected NH unit through Rh(iii)-catalyzed cascade reactions of 2-arylindoles or 2-arylindole-3-carbonitriles with α-diazo carbonyl compounds has been established. To our knowledge, this is the first example in which the NH unit of indole is used as a directing group for an intramolecular C(sp(2))-H bond functionalization to give benzo[a]carbazole derivatives. Notably, this method features easily obtainable substrates, good functional group tolerance, excellent regio-selectivity, and high atom-efficiency.

  9. 1,2-Di­hydro­spiro­[carbazole-3(4H),2′-[1,3]dioxolane

    OpenAIRE

    Bjerrum, Janni Vester; Ulven, Trond; Bond, Andrew D.

    2009-01-01

    In the title compound, C14H15NO2, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the dioxolane ring points to one side of the carbazole plane. Neighbouring mol­ecules form edge-to-face inter­actions in which the NH group is directed towards an adjacent carbazole unit, with a shortest H⋯C contact of 2.72 Å. These inter­actions arrange the mol­ecules into one-dimensional herringbone-type motifs, which pack so that the methyl­ene groups of the dioxo...

  10. Indolo[2,3-b]carbazole synthesized from a double-intramolecular Buchwald-Hartwig reaction: its application for a dianchor DSSC organic dye.

    Science.gov (United States)

    Su, Jia-Yi; Lo, Chun-Yuan; Tsai, Chih-Hung; Chen, Chih-Han; Chou, Shu-Hua; Liu, Shih-Hung; Chou, Pi-Tai; Wong, Ken-Tsung

    2014-06-20

    A new synthetic strategy for indolo[2,3-b]carbazole via a double-intramolecular Buchwald-Hartwig reaction has been established. The N-alkylated indolo[2,3-b]carbazole then was adopted as the geometry-fixed core for the synthesis of a new molecule (ICZDTA) bearing two bithiophene π-bridged 2-cyanoacrylic acid groups as the bidentate anchor. The bidentate anchoring together with efficient HOMO (indolo[2,3-b]carbazole) → LUMO (TiO2 nanocluster) electron transfer leads to the successful development of ICZDTA-based DSSC with a power conversion efficiency of 6.02%.

  11. Assembly of BODIPY-carbazole dyes with liposomes to fabricate fluorescent nanoparticles for lysosomal bioimaging in living cells.

    Science.gov (United States)

    Lv, Hai-Juan; Zhang, Xiao-Tai; Wang, Shu; Xing, Guo-Wen

    2017-01-31

    Two BODIPY-carbazole dye based fluorescent probes BCA and BCAS were designed, synthesized and encapsulated by liposomes to obtain fluorescent nanoparticles BCA-FNP and BCAS-FNP. The fluorescence imaging showed that BCA-FNP was membrane-permeable and capable of localizing lysosomes in living cells.

  12. DFT and experimental studies on structure and spectroscopic parameters of 3,6-diiodo-9-ethyl-9H-carbazole

    DEFF Research Database (Denmark)

    Radula-Janik, Klaudia; Kupka, Teobald; Ejsmont, Krzysztof;

    2016-01-01

    The first report on crystal and molecular structure of 3,6-diiodo-9-ethyl-9H-carbazole is presented. Experimental room-temperature X-ray and 13C chemical shift studies were supported by advanced theoretical calculations using density functional theory (DFT). The 13C nuclear magnetic shieldings we...

  13. Smart windows application of carbazole and triazine based star shaped architecture.

    Science.gov (United States)

    Guzel, Merve; Soganci, Tugba; Ayranci, Rukiye; Ak, Metin

    2016-08-01

    A novel triazine-based, star shape and electroactive monomer, 2,4,6-tris(2-(9H-carbazol-9-yl)ethoxy)-1,3,5-triazine (TCZ) which contains 2,4,6-trichloro-1,3,5-triazine as the core and 2-(9H-carbazol-9-yl)ethanol as the arms, was successfully synthesized. After electrochemical polymerization of the TCZ monomer, called PTCZ, the polymer shows superior optoelectronic and thermal properties due to its unique three-dimensional shape and highly-branched structure in comparison with linear analogues. Electrochromic studies exhibited that PTCZ has turquoise color in the oxidized state and is transparent in the neutral state. Due to the fact that the redox color characteristics of PTCZ are indispensable for smart windows, a PTCZ-based electrochromic device was formed with PEDOT as complementary coloring material. A potential range of -1.5 to +1.8 V was determined to be suitable for operating the PTCZ/PEDOT device between transparent and blue colors. Characterizations of the device were performed in term of switching times, optical contrast, optical memory and redox stability.

  14. Photoluminescence of donor-acceptor carbazole-based molecules in amorphous and powder forms

    Science.gov (United States)

    Adès, D.; Boucard, V.; Cloutet, E.; Siove, A.; Olivero, C.; Castex, M. C.; Pichler, G.

    2000-05-01

    We present absorption and photoluminescence features of four samples of carbazole molecules substituted with various electron-acceptor groups. These molecules named 1-(N-ethylcarbazolyl)-2-substituted-2-cyanovinylene contain in their structure the electron-donor carbazole nucleus and cyanovinylene bearing either another nitrile function, an ethylester, a phenyl, or a para-nitrophenyl groups. It is shown that depending on the strength of the donor-acceptor internal charge transfer, both the absorption and emission spectra are more or less redshifted. It is found that the ethyl-ester derivative displays the best relative photoluminescence efficiency among all the samples and its peak is measured at 490 nm when taking amorphous thin film. The microcrystalline powder form of the same material exhibits spectral narrowing and shift of the peak emission. We obtain further narrowing of the emission band and further redshifting of the emission when we illuminate, transversely, a glass capillary containing the crystalline sample by an ultraviolet light-emitting diode.

  15. Valence one-electron and shake-up ionization bands of fluorene, carbazole and dibenzofuran

    Energy Technology Data Exchange (ETDEWEB)

    Reza Shojaei, S.H.; Morini, Filippo; Deleuze, Michael S., E-mail: michael.deleuze@uhasselt.be

    2013-05-16

    Highlights: • The photoelectron spectra of the title compounds are assigned in details. • Shake-up lines are found to severely contaminate both π- and σ-ionization bands. • σ-ionization onsets are subject to severe vibronic coupling complications. • We compare the results of OVGF, ADC(3) and TDDFT calculations. - Abstract: A comprehensive study of the He (I) ultra-violet photoelectron spectra of fluorene, carbazole and dibenzofuran is presented with the aid of one-particle Green’s Function calculations employing the outer-valence Green’s Function (OVGF) approach and the third-order algebraic diagrammatic construction [ADC(3)] scheme, along with Dunning’s correlation consistent basis sets of double and triple zeta quality (cc-pVDZ, cc-pVTZ). Extrapolations of the ADC(3) results for the outermost one-electron π-ionization energies to the cc-pVTZ basis set enable theoretical insights into He (I) measurements within ∼0.15 eV accuracy, up to the σ-ionization onset. The lower ionization energy of carbazole is the combined result of mesomeric and electronic relaxation effects. OVGF/cc-pVDZ or OVGF/cc-pVTZ pole strengths smaller than 0.85 systematically corroborate a breakdown of the orbital picture of ionization at the ADC(3) level. Comparison is made with calculations of the lowest doublet–doublet excitation energies of the radical cation of fluorene, by means of time-dependent density functional theory (TDDFT)

  16. Solvent-dependent fluorescence enhancement and piezochromism of a carbazole-substituted naphthopyran

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lihui; Wang, Aixia [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Wang, Guang, E-mail: wangg923@nenu.edu.cn [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Munyentwari, Alexis [Faculty of Chemistry, Northeast Normal University, Changchun 130024 (China); Zhou, Yihan, E-mail: yhzhou@ciac.ac.cn [National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2015-09-15

    A novel carbazole-substituted naphthopyran, 3,3-bis-(4-carbazolylphenyl)-[3H]-naphtho[2,1-b]pyran (CzNP) was designed and synthesized. The new compound exhibited normal photochromism in dichloromethane solution and the UV irradiation did not influence its fluorescence. On the contrary, the fluorescence of CzNP in N,N-dimethylformamide (DMF) was intensively enhanced to 29 times after 60 min of the UV irradiation and this enhanced fluorescence can be quenched by addition of triethylamine (TEA). The study of enhanced extent of fluorescence of CzNP in solvents with different polarities and in mixed solvents demonstrated that the enhanced fluorescence is dependent on the polarity of solvents. The larger the polarity of solvent was, the stronger was the fluorescence of CzNP. CzNP also exhibited piezochromic performance and the pressure led to the cleavage of the C–O bond of pyran ring. - Highlights: • A carbazole-substituted photochromic naphthopyran was designed and synthesized. • The fluorescence was enhanced under the existence of DMF and UV irradiation. • The polarity of solvent was the dominating factor to affect the fluorescence. • The new compound also displayed piezochromic performance.

  17. Analysis of the core genome and pangenome of Pseudomonas putida.

    Science.gov (United States)

    Udaondo, Zulema; Molina, Lázaro; Segura, Ana; Duque, Estrella; Ramos, Juan L

    2016-10-01

    Pseudomonas putida are strict aerobes that proliferate in a range of temperate niches and are of interest for environmental applications due to their capacity to degrade pollutants and ability to promote plant growth. Furthermore solvent-tolerant strains are useful for biosynthesis of added-value chemicals. We present a comprehensive comparative analysis of nine strains and the first characterization of the Pseudomonas putida pangenome. The core genome of P. putida comprises approximately 3386 genes. The most abundant genes within the core genome are those that encode nutrient transporters. Other conserved genes include those for central carbon metabolism through the Entner-Doudoroff pathway, the pentose phosphate cycle, arginine and proline metabolism, and pathways for degradation of aromatic chemicals. Genes that encode transporters, enzymes and regulators for amino acid metabolism (synthesis and degradation) are all part of the core genome, as well as various electron transporters, which enable aerobic metabolism under different oxygen regimes. Within the core genome are 30 genes for flagella biosynthesis and 12 key genes for biofilm formation. Pseudomonas putida strains share 85% of the coding regions with Pseudomonas aeruginosa; however, in P. putida, virulence factors such as exotoxins and type III secretion systems are absent.

  18. Carboxylate ligands induced structural diversity of zinc(II) coordination polymers based on 3,6-bis(imidazol-1-yl)carbazole: Syntheses, structures and photocatalytic properties

    Science.gov (United States)

    Cheng, Hong-Jian; Tang, Hui-Xiang; Shen, Ya-Li; Xia, Nan-Nan; Yin, Wen-Yu; Zhu, Wei; Tang, Xiao-Yan; Ma, Yun-Sheng; Yuan, Rong-Xin

    2015-12-01

    Solvothermal reactions of Zn(NO3)2·6H2O with 3,6-bis(1-imidazolyl)carbazole (3,6-bmcz) and 1,4-benzenedicarboxylic acid (1,4-H2bdc), p-phenylenediacetic acid (p-H2pda), benzophenone-4,4-dicarboxylic acid (H2bpda) afforded three coordination polymers [Zn(1,4-bdc)(3,6-bmcz)]n (1), {[Zn(p-pda)(3,6-bmcz)]·1.5H2O}n (2) and {[Zn(bpda)(3,6-bmcz)]·0.25H2O}n (3). Complexes 1-3 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. Complex 1 shows 3D structure with 2D nets inclined polycatenation. Complexes 2 and 3 possess an extended 3D supramolecular architecture based on their respective 2D layers through hydrogen-bonding interactions and the π···π stacking interactions. The solid state luminescent and optical properties of 1-3 at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methylene blue in polluted water was explored.

  19. Carboxylate ligands induced structural diversity of zinc(II) coordination polymers based on 3,6-bis(imidazol-1-yl)carbazole: Syntheses, structures and photocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hong-Jian, E-mail: hjcheng@cslg.cn; Tang, Hui-Xiang; Shen, Ya-Li; Xia, Nan-Nan; Yin, Wen-Yu; Zhu, Wei; Tang, Xiao-Yan; Ma, Yun-Sheng; Yuan, Rong-Xin, E-mail: yuanrx@cslg.edu.cn

    2015-12-15

    Solvothermal reactions of Zn(NO{sub 3}){sub 2}·6H{sub 2}O with 3,6-bis(1-imidazolyl)carbazole (3,6-bmcz) and 1,4-benzenedicarboxylic acid (1,4-H{sub 2}bdc), p-phenylenediacetic acid (p-H{sub 2}pda), benzophenone-4,4-dicarboxylic acid (H{sub 2}bpda) afforded three coordination polymers [Zn(1,4-bdc)(3,6-bmcz)]{sub n} (1), {[Zn(p-pda)(3,6-bmcz)]·1.5H_2O}{sub n} (2) and {[Zn(bpda)(3,6-bmcz)]·0.25H_2O}{sub n} (3). Complexes 1–3 were characterized by elemental analysis, IR, powder X-ray diffraction, and single-crystal X-ray diffraction. Complex 1 shows 3D structure with 2D nets inclined polycatenation. Complexes 2 and 3 possess an extended 3D supramolecular architecture based on their respective 2D layers through hydrogen-bonding interactions and the π···π stacking interactions. The solid state luminescent and optical properties of 1–3 at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methylene blue in polluted water was explored. - Graphical abstract: Reactions of Zn(NO{sub 3}){sub 2} and 3,6-(1-imidazolyl)carbazole with 1,4-benzenedicarboxylic acid, p-phenylenediacetic acid or benzophenone-4,4-dicarboxylic acid afforded three coordination polymers with different topologies and photocatalytic activity. - Highlights: • Reactions of 1,4-H{sub 2}bdc, p-H{sub 2}pda or H{sub 2}bpda with 3,6-bmcz and Zn(II) gave three CPs. • Complex 1 is a 3D entanglement. • Complex 2 or 3 is a 3D supramolecular structure based on different 2D layers. • Complex 2 exhibited good catalytic activity of methylene blue photodegradation.

  20. 1,2-Di­hydro­spiro­[carbazole-3(4H),2′-[1,3]dioxolane

    Science.gov (United States)

    Bjerrum, Janni Vester; Ulven, Trond; Bond, Andrew D.

    2009-01-01

    In the title compound, C14H15NO2, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the dioxolane ring points to one side of the carbazole plane. Neighbouring mol­ecules form edge-to-face inter­actions in which the NH group is directed towards an adjacent carbazole unit, with a shortest H⋯C contact of 2.72 Å. These inter­actions arrange the mol­ecules into one-dimensional herringbone-type motifs, which pack so that the methyl­ene groups of the dioxolane ring lie over the face of a neighbouring carbazole unit with a shortest H⋯C contact of 2.85 Å. PMID:21582234

  1. 3-Methoxy-2-methyl-carbazole-1,4-quinone, carbazomycins D and F from Streptomyces sp. CMU-JT005.

    Science.gov (United States)

    Ruanpanun, Pornthip; Dame, Zerihun Teklemariam; Laatsch, Hartmut; Lumyong, Saisamorn

    2011-09-01

    3-Methoxy-2-methyl-carbazole-1,4-quinone (1) together with carbazomycins D (2) and F (3) were isolated from the crude extract of Streptomyces CMU-JT005, an actinomycete with nematicidal activity. 3-Methoxy-2-methyl-carbazole-1,4-quinone is reported here for the first time from nature. In this paper, we describe the isolation and structure elucidation of the compounds together with the characterization of the Streptomyces strain CMU-JT005.

  2. Pseudomonas Aeruginosa Toxins

    Science.gov (United States)

    1982-09-01

    circulatory collapse, and leucopenia . These observations were similar to those made in Pseudomonas infections. This work resulted in great stimulation...Sensakovic and Bartell (1974) reported that a toxic slime fraction caused leucopenia in mice, and the relative contribution of these factors and of exotoxin...A to leucopenia remains to be determined. Finally. the low incidence of leucocidin producing strains argue against any significant importance of

  3. Mass spectrometry analysis of surface tension reducing substances produced by a pah-degrading Pseudomonas citronellolis strain Análise por espectrometria de massa de substâncias redutoras da tensão superficial produzidas por uma cepa de Pseudomonas citronellolis degradadora de hidrocarbonetos aromáticos policíclicos

    Directory of Open Access Journals (Sweden)

    Rodrigo J. S. Jacques

    2008-06-01

    Full Text Available In this work we investigated the structure of the iron-stimulated surface tension reducing substances produced by P. citronellolis 222A isolated from a 17-years old landfarming used for sludge treatment in petrochemical industries and oil refinery. Its mass spectrum differs from P. aeruginosa spectrum, indicating that the surface tension reducing substances produced by P. citronellolis can be a new kind of biosurfactant.Neste trabalho é apresentado um estudo a respeito da análise da estrutura de substâncias redutoras de tensão superficial produzidas por Pseudomonas citronellolis 222A estimulado pela presença de ferro. Esta bactéria foi isolada de um solo que há 17 anos vem sendo utilizado para o tratamento de borra oleosa proveniente da indústria petroquímica e de refinaria de petróleo. O espectro de massa difere do espectro de P. aeruginosa, indicando que as substâncias redutoras de tensão superficial produzidas por P. citronellolis podem ser um novo tipo de biosurfactante.

  4. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Directory of Open Access Journals (Sweden)

    Dnyanada S. Khanolkar

    2014-12-01

    Full Text Available A bacterial isolate capable of utilizing tributyltin chloride (TBTCl as sole carbon source was isolated from estuarine sediments of west coast of India and identified as Pseudomonas stutzeri based on biochemical tests and Fatty acid methyl ester (FAME analysis. This isolate was designated as strain DN2. Although this bacterial isolate could resist up to 3 mM TBTCl level, it showed maximum growth at 2 mM TBTCl in mineral salt medium (MSM. Pseudomonas stutzeri DN2 exposed to 2 mM TBTCl revealed significant alteration in cell morphology as elongation and shrinkage in cell size along with roughness of cell surface. FTIR and NMR analysis of TBTCl degradation product extracted using chloroform and purified using column chromatography clearly revealed biotransformation of TBTCl into Dibutyltin dichloride (DBTCl2 through debutylation process. Therefore, Pseudomonas stutzeri strain DN2 may be used as a potential bacterial strain for bioremediation of TBTCl contaminated aquatic environmental sites.

  5. Efficient fluorescent deep-blue and hybrid white emitting devices based on carbazole/benzimidazole compound

    KAUST Repository

    Yang, Xiaohui

    2011-07-28

    We report the synthesis, photophysics, and electrochemical characterization of carbazole/benzimidazole-based compound (Cz-2pbb) and efficient fluorescent deep-blue light emitting devices based on Cz-2pbb with the peak external quantum efficiency of 4.1% and Commission Internationale dÉnclairage coordinates of (0.16, 0.05). Efficient deep-blue emission as well as high triplet state energy of Cz-2pbb enables fabrication of hybrid white organic light emitting diodes with a single emissive layer. Hybrid white emitting devices based on Cz-2pbb show the peak external quantum efficiency exceeding 10% and power efficiency of 14.8 lm/W at a luminance of 500 cd/m2. © 2011 American Chemical Society.

  6. A new cytotoxic carbazole alkaloid and two new other alkaloids from Clausena excavata.

    Science.gov (United States)

    Peng, Wen-Wen; Zeng, Guang-Zhi; Song, Wei-Wu; Tan, Ning-Hua

    2013-07-01

    One new carbazole alkaloid, excavatine A (1), and two additional new alkaloids, excavatine B (2) and excavatine C (3), were isolated from the stems and leaves of Clausena excavata Burm.f. (Rutaceae). Their structures were determined on the basis of detailed spectroscopic analyses, especially 2D-NMR and HR-EI-MS data. Compounds 1-3 were tested for their cytotoxic activities against A549, HeLa, and BGC-823 cancer cell lines, and for their antimicrobial activities against Candida albicans and Staphylococcus aureus. Only 1 exhibited cytotoxicity against A549 and HeLa cell lines with the IC50 values of 5.25 and 1.91 μg/ml, respectively.

  7. Synthesis of novel carbazole chalcones as radical scavenger, antimicrobial and cancer chemopreventive agents.

    Science.gov (United States)

    Bandgar, Babasaheb P; Adsul, Laxman K; Lonikar, Shrikant V; Chavan, Hemant V; Shringare, Sadanand N; Patil, Sachin A; Jalde, Shivkumar S; Koti, Basawaraj A; Dhole, Nagesh A; Gacche, Rajesh N; Shirfule, Amol

    2013-06-01

    A series of novel carbazole chalcones has been synthesised and evaluated for radical scavenging activity, cytotoxicity and antimicrobial activities. Compounds 12m, 12o and 12c exhibited good 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, compounds 12e, 12m and 12d were excellent hydroxyl radical scavengers and compounds 12a, 12e, 12g, 12n and 12m have shown inhibition of oxidative DNA damage induced by 2,2'-azobis (2-amidinopropane hydrochloride). Compounds 12j, 12i, 12n, 12c, 12m and 12e were most active against the selected cancer cell lines. Compounds 12a, 12e and 12m showed good antibacterial activity and compounds 12h and 12m have shown good antifungal activity. All the compounds were subjected for absorption, distribution, metabolism and excretion (ADME) predictions by computational method and found that these molecules could be considered as potential candidates for oral drug development.

  8. Ethyl 4,9-dimethyl-9H-carbazole-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Serkan Öncüoğlu

    2014-03-01

    Full Text Available In the title compound, C17H17NO2, the carbazole skeleton includes an ethoxycarbonyl group at the 3-position. The indole three-ring system is almost planar [maximum deviation = 0.065 (2 Å], and the ethyl ester group is inclined to its mean plane by 15.48 (2°. In the crystal, there are π–π stacking interactions between parallel benzene rings and between parallel benzene and pyrrole rings of adjacent molecules [centroid–centroid distances = 3.9473 (8 and 3.7758 (8 Å, respectively]. Weak C—H...π interactions are also present.

  9. Understanding the domino reaction between 3-chloroindoles and methyl coumalate yielding carbazoles. A DFT study.

    Science.gov (United States)

    Domingo, Luis R; Sáez, José A; Emamian, Saeed R

    2015-02-21

    The molecular mechanism of the reaction between N-methyl-3-chloroindole and methyl coumalate yielding carbazole has been studied using DFT methods at the MPWB1K/6-311G(d,p) level in toluene. This reaction is a domino process that comprises three consecutive reactions: (i) a polar Diels-Alder (P-DA) reaction between indole and methyl coumalate yielding two stereoisomeric [2 + 4] cycloadducts (CAs); (ii) the elimination of HCl from these CAs affording two stereoisomeric intermediates; and (iii) the extrusion of CO2 in these intermediates, finally yielding the carbazole. This P-DA reaction proceeds in a completely regioselective and slightly exo selective fashion. In spite of the highly polar character of this P-DA reaction, it presents a high activation enthalpy of 21.8 kcal mol(-1) due to the loss of the aromatic character of the indole during the C-C bond formation. Thermodynamic calculations suggest that the P-DA reaction is the rate-determining step of this domino reaction; in addition, the initial HCl elimination in the formal [2 + 4] CAs is kinetically favoured over the extrusion of CO2. Although the P-DA reaction is kinetically and thermodynamically very unfavourable, the easier HCl and CO2 elimination from the [2 + 4] CAs together with the strong exergonic character of the CO2 extrusion makes the P-DA reaction irreversible. An ELF topological analysis of the bonding changes along the P-DA reaction supports a two-stage one-step mechanism. An analysis of the global DFT reactivity indices at the ground state of the reagents confirms the highly polar character of this P-DA reaction. Finally, the complete regioselectivity of the studied reactions can be explained using the Parr functions.

  10. Properties, theoretical study and crystal structure of 3-benzothiazole-9-ethyl carbazole.

    Science.gov (United States)

    Gu, Yingchun; Lin, Dayong; Fei, Xuening; Wang, Cuihong; Li, Ling; Tang, Yalin; Zhou, Jianguo

    2016-09-01

    The title compound of 3-benzothiazole-9-ethyl carbazole was synthesized by the reaction of 3-aldehyde-9-ethyl carbazole and 2-aminothiophenol. The compound was characterized by (1) H nuclear magnetic resonance (NMR) and mass spectrometry (MS). Its crystal structure was obtained and determined by single crystal X-ray diffraction. The results showed that the crystal belongs to the orthorhombic crystal system and the cell parameters of space group P2(1)2(1)2(1) were a = 5.6626 (12) Å, b = 12.606 (3) Å, c = 22.639 (5) Å, α = 90°, β = 90°, γ = 90°, V = 1616.0 (6) Å(3) , Z = 4, Dc = 1.350 mg/m(3) . The UV-vis and fluorescence spectra were also studied preliminarily. The fluorescence spectra of the title compound with bovine serum albumin (BSA) showed that BSA could be marked with the compound and the stability constant between them was 0.82 × 10(7)  M(-1) . Meanwhile, the crystal and molecule were theoretically surveyed by density functional tight-binding (DFTB). The results showed that there was an orbital overlap for lowest unoccupied molecular orbital (LUMO) between the neighbouring molecules for the crystal, which is different from the molecule structure. It was also showed that the crystal structure is a non-conductor. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Ferulic acid-carbazole hybrid compounds: Combination of cholinesterase inhibition, antioxidant and neuroprotection as multifunctional anti-Alzheimer agents.

    Science.gov (United States)

    Fang, Lei; Chen, Mohao; Liu, Zhikun; Fang, Xubin; Gou, Shaohua; Chen, Li

    2016-02-15

    In order to search for novel multifunctional anti-Alzheimer agents, a series of ferulic acid-carbazole hybrid compounds were designed and synthesized. Ellman's assay revealed that the hybrid compounds showed moderate to potent inhibitory activity against the cholinesterases. Particularly, the AChE inhibition potency of compound 5k (IC50 1.9μM) was even 5-fold higher than that of galantamine. In addition, the target compounds showed pronounced antioxidant ability and neuroprotective property, especially against the ROS-induced toxicity. Notably, the neuroprotective effect of 5k was obviously superior to that of the mixture of ferulic acid and carbazole, indicating the therapeutic effect of the hybrid compound is better than the combination administration of the corresponding mixture.

  12. Synthesis and Characterization of Carbazole-Benzothiadiazole-Based Conjugated Polymers for Organic Photovoltaic Cells with Triazole in the Main Chain

    Directory of Open Access Journals (Sweden)

    Eunhee Lim

    2013-01-01

    Full Text Available We have synthesized a series of carbazole-benzothiadiazole-triazole based copolymers, poly[(N-9′-heptadecanyl-2,7-carbazole-co-(5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole-co-((4-(4-butylphenyl-3,5-diphenyl-4H-1,2,4]triazole] (PCz3TBTz by Suzuki coupling polymerization. The optical and electrochemical properties of the copolymers could be tuned by changing the comonomer unit of triazole from 0% to 80%. Organic photovoltaic (OPV cells were fabricated by blending the synthesized polymers as a donor and PCBM as an acceptor. The material solubility and film morphology were improved by introducing the triazole unit in the main chain. Improved OPV device performance of 1.74% was achieved in the presence of an optimal amount of triazole moieties.

  13. Pseudomonas genomes: diverse and adaptable.

    Science.gov (United States)

    Silby, Mark W; Winstanley, Craig; Godfrey, Scott A C; Levy, Stuart B; Jackson, Robert W

    2011-07-01

    Members of the genus Pseudomonas inhabit a wide variety of environments, which is reflected in their versatile metabolic capacity and broad potential for adaptation to fluctuating environmental conditions. Here, we examine and compare the genomes of a range of Pseudomonas spp. encompassing plant, insect and human pathogens, and environmental saprophytes. In addition to a large number of allelic differences of common genes that confer regulatory and metabolic flexibility, genome analysis suggests that many other factors contribute to the diversity and adaptability of Pseudomonas spp. Horizontal gene transfer has impacted the capability of pathogenic Pseudomonas spp. in terms of disease severity (Pseudomonas aeruginosa) and specificity (Pseudomonas syringae). Genome rearrangements likely contribute to adaptation, and a considerable complement of unique genes undoubtedly contributes to strain- and species-specific activities by as yet unknown mechanisms. Because of the lack of conserved phenotypic differences, the classification of the genus has long been contentious. DNA hybridization and genome-based analyses show close relationships among members of P. aeruginosa, but that isolates within the Pseudomonas fluorescens and P. syringae species are less closely related and may constitute different species. Collectively, genome sequences of Pseudomonas spp. have provided insights into pathogenesis and the genetic basis for diversity and adaptation.

  14. Determination by ultraviolet absorption spectrometry and theoretical calculation of dissociation constant of 1,2,3,9-tetrahydro-4H-carbazol-4-one.

    Science.gov (United States)

    Zhang, Shufang; Zhang, Xiaoyan; Tang, Ke; Zhou, Zhengyu

    2009-08-15

    The dissociation constant of 1,2,3,9-tetrahydro-4H-carbazol-4-one was determined by ultraviolet absorption spectrometry method based on the absorption spectra of 1,2,3,9-tetrahydro-4H-carbazol-4-one at different pH in ethanol-water mixed solvents. The results show that the pK(b) was a good linear function of the volume fraction of ethanol in the concentration range studied. The dissociation constant of 1, 2, 3,9-tetrahydro-4H-carbazol-4-one in water were determined by extrapolation to be 14.04 under the condition of this experiment. The accurate pK(b) calculations of 1,2,3,9-tetrahydro-4H-carbazol-4-one have been investigated using the combination of the extended clusters-continuum model with the polarizable continuum solvation model (PCM). The calculations are performed at the B3LYP/6-31G levels. The formation of molecular clusters by means of the 1,2,3,9-tetrahydro-4H-carbazol-4-one wrapped up with water molecules leads to the weakness of the interaction between the polar solvents and the 1,2,3,9-tetrahydro-4H-carbazol-4-one, hence, the accuracy of pK(b) has been enhanced. The dissociation constant of 1,2,3,9-tetrahydro-4H-carbazol-4-one in water were calculated to be 14.10 and agreed well with experimental data.

  15. Transcriptomic insight into terpenoid and carbazole alkaloid biosynthesis, and functional characterization of two terpene synthases in curry tree (Murraya koenigii)

    Science.gov (United States)

    Meena, Seema; Rajeev Kumar, Sarma; Dwivedi, Varun; Kumar Singh, Anup; Chanotiya, Chandan S.; Akhtar, Md. Qussen; Kumar, Krishna; Kumar Shasany, Ajit; Nagegowda, Dinesh A.

    2017-01-01

    Curry tree (Murraya koenigii L.) is a rich source of aromatic terpenes and pharmacologically important carbazole alkaloids. Here, M. koenigii leaf transcriptome was generated to gain insight into terpenoid and alkaloid biosynthesis. Analysis of de novo assembled contigs yielded genes for terpene backbone biosynthesis and terpene synthases. Also, gene families possibly involved in carbazole alkaloid formation were identified that included polyketide synthases, prenyltransferases, methyltransferases and cytochrome P450s. Further, two genes encoding terpene synthases (MkTPS1 and MkTPS2) with highest in silico transcript abundance were cloned and functionally characterized to determine their involvement in leaf volatile formation. Subcellular localization using GFP fusions revealed the plastidial and cytosolic localization of MkTPS1 and MkTPS2, respectively. Enzymatic characterization demonstrated the monoterpene synthase activity of recombinant MkTPS1, which produced primarily (−)-sabinene from geranyl diphosphate (GPP). Recombinant MkTPS2 exhibited sesquiterpene synthase activity and formed (E,E)-α-farnesene as the major product from farnesyl diphosphate (FPP). Moreover, mRNA expression and leaf volatile analyses indicated that MkTPS1 accounts for (−)-sabinene emitted by M. koenigii leaves. Overall, the transcriptome data generated in this study will be a great resource and the start point for characterizing genes involved in the biosynthetic pathway of medicinally important carbazole alkaloids. PMID:28272514

  16. HIDRODENITROGENACION DE CARBAZOL SOBRE CATALIZADORES NiMo/Al2O3-SiO2(x

    Directory of Open Access Journals (Sweden)

    Felipe Sánchez-Minero

    2012-01-01

    Full Text Available En este trabajo se estudió la velocidad de reacción del carbazol sobre catalizadores NiMo soportados sobre Al2O3 modificada superficialmente con SiO2 (0 y 10 % en peso de SiO2 en el soporte. Los catalizadores fueron evaluados en un reactor intermitente a cuatro temperaturas (287, 300, 312 y 325oC, presión de 4.0 MPa y relación molar hidrogeno/carbazol de 2400. A partir de los resultados experimentales se realizó un estudio cinético utilizando ecuaciones del tipo Langmuir-Hinshelwood (L-H. Luego, los parámetros cinéticos fueron estimados mediante la minimización de Powell (programa Scientist de MicroMath. Los resultados muestran que el catalizador con sílice (NiMo-SAC 10 alcanza una mayor actividad para la HDN de carbazol debido a que presenta un mayor número de sitios activos (valor de A, así como una menor fuerza de adsorción entre el reactante y la superficie catalítica (valor de KN, lo cual posiblemente favorece una mejor regeneración de sitios activos.

  17. SYNTHESIS,CHARACTERIZATION AND PHOTOLUMINESCENT PROPERTIES OF NEW PLATINUM-CONTAINING POLY(FLUORENYLENEETHYNYLENE) ANCHORED WITH CARBAZOLE PENDANTS

    Institute of Scientific and Technical Information of China (English)

    Cheuk-lam Ho; Wai-yeung Wong

    2009-01-01

    A new luminescent and thermally stable platinum(Ⅱ) polyyne polymer trans-[-Pt(PBu3)2C≡CArC≡C-]n (P1) containing the 2,7-fluorene chromophoric spacer substituted by pendant carbazolyl group via long alkyl bridges. The regiochemical structures of these compounds were studied by various spectroscopic analyses. We report the photophysical properties of this group 10 polymetallayne and a comparison was made to its binuclear model complex trans-[Pt(Ph)(PEt3)2C≡CArC≡CPt(Ph)(PEt3)2] (M1) as well as to those with non-carbazole-containing fluorene spacer (P2 and M2). Upon photoexcitation, each of P1 and M1 emits an intense purple-blue fluorescence emission in the near-UV to visible region in dilute fluid solutions at room temperature. Harvesting of organic triplet emissions harnessed through the strong heavy-atom effects of platinum metal was examined and at 77 K, each of the metalated compounds displayed dual emission bands, viz. Both the fluorescence and the lower-lying phosphorescence. Spectroscopic results revealed that the formation of excimers was suppressed by introducing carbazole side groups. The spatial extent of the lowest singlet and triplet excitons in PI and M1 was fully elucidated. Such organometallic poly(fluorenyleneethynylene)s anchored with the carbazole pendants was found to have an improved thermal stability and suppressed aggregation.

  18. Microbial assisted High Impact Polystyrene (HIPS) degradation.

    Science.gov (United States)

    Mohan, Arya J; Sekhar, Vini C; Bhaskar, Thallada; Nampoothiri, K Madhavan

    2016-08-01

    The efficacy of newly isolated Pseudomonas and Bacillus strains to degrade brominated High Impact Polystyrene (HIPS) was investigated. Viability of these cultures while using e-plastic as sole carbon source was validated through Triphenyl Tetrazolium Chloride (TTC). Four days incubation of HIPS emulsion with Bacillus spp. showed 94% reduction in turbidity and was 97% with Pseudomonas spp. Confirmation of degradation was concluded by HPLC, NMR, FTIR, TGA and weight loss analysis. NMR spectra of the degraded film revealed the formation of aliphatic carbon chain with bromine and its release. FTIR analysis of the samples showed a reduction in CH, CO and CN groups. Surface changes in the brominated HIPS film was visualized through SEM analysis. Degradation with Bacillus spp showed a weight loss of 23% (w/w) of HIPS film in 30days.

  19. Bacterial isolates degrading aliphatic polycarbonates.

    Science.gov (United States)

    Suyama, T; Hosoya, H; Tokiwa, Y

    1998-04-15

    Bacteria that degrade an aliphatic polycarbonate, poly(hexamethylene carbonate), were isolated from river water in Ibaraki. Prefecture, Japan, after enrichment in liquid medium containing poly(hexamethylene carbonate) suspensions as carbon source, and dilution to single cells. Four of the strains, 35L, WFF52, 61A and 61B2, degraded poly(hexamethylene carbonate) on agar plate containing suspended poly(hexamethylene carbonate). Degradation of poly(hexamethylene carbonate) was confirmed by gel permeation chromatography. Besides poly(hexamethylene carbonate), the strains were found to degrade poly(tetramethylene carbonate). The strains were characterized morphologically, physiologically, and by 16S rDNA sequence analysis. Strains 35L and WFF52 were tentatively identified as Pseudomonas sp. and Variovorax sp., respectively, while strains 61A and 61B2 constitute an unidentified branch within the beta subclass of the Proteobacteria.

  20. Systematic investigations on the biodegradation and viscosity reduction of long chain hydrocarbons using Pseudomonas aeruginosa and Pseudomonas fluorescens.

    Science.gov (United States)

    Sakthipriya, N; Doble, Mukesh; Sangwai, Jitendra S

    2016-03-01

    The use of microorganisms has been researched extensively for possible applications related to hydrocarbon degradation in the petroleum industry. However, attempts to improve the effect of microorganisms on the viscosity of hydrocarbons, which find potential use in the development of robust models for biodegradation, have been rarely documented. This study investigates the degradation of long chain hydrocarbons, such as hexadecane and eicosane using Pseudomonas fluorescens PMMD3 (P. fluorescens) and Pseudomonas aeruginosa CPCL (P. aeruginosa). P. aeruginosa used here is isolated from petroleum contaminated sediments and the P. fluorescens is from the coastal area, and both have hydrocarbon degrading genes. The degradation of hydrocarbons is studied using carbon profiling and reduction in viscosity pre- and post-degradation of hydrocarbons. The carbon profiling has been obtained using gas chromatography-mass spectroscopy (GC-MS), and Fourier transform infrared spectrometer (FTIR) results. GC-MS results have indicated an improved biodegradation of hydrocarbons by 77-93% in one day. The yield coefficients of biomass (YX/S) for P. aeruginosa and P. fluorescens using hexadecane as a carbon source are 1.35 and 0.81 g g(-1), and the corresponding values with eicosane are 0.84 and 0.88 g g(-1). The viscosity of hexadecane is reduced by the order of 53 and 47%, while that of eicosane was reduced by 53 and 65%, using P. aeruginosa and P. fluorescens, respectively. This study also presents information on the activity of enzymes responsible for the hydrocarbon degradation. Pseudomonas species have shown their use in potential applications for bioremediation, oil-spill treatment, and flow assurance. We believe that this study will also provide stringent tests for possible model development for the bioremediation of long chain paraffins suitable for oilfield applications.

  1. 4-Fluoro-N-methyl-N-(1,2,3,4-tetra­hydro­carbazol-3-yl)benzene­sulfonamide

    Science.gov (United States)

    Rasmussen, Kaspar Gothardt; Ulven, Trond; Bond, Andrew D.

    2009-01-01

    In the title compound, C19H19FN2O2S, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the plane of the fluoro­phenyl ring forms a dihedral angle of 41.5 (1)° with respect to the carbazole mean plane. The crystal structure is segregated into layers containing the carbazole units and fluoro­phenyl rings in alternate (200) planes. The carbazole units form centrosymmetric face-to-face inter­actions [inter­planar separation = 4.06 (1) Å] and edge-to-face inter­actions in which the N—H group is directed towards an adjacent carbazole face, with a shortest H⋯C contact of 2.53 Å. The fluoro­phenyl rings form face-to-face contacts with an approximate inter­planar separation of 3.75 Å and a centroid–centroid distance of 4.73 (1) Å. PMID:21582475

  2. Antimicrobial activity of carbazole compounds:research advances%具有抗微生物活性咔唑类化合物的研究进展

    Institute of Scientific and Technical Information of China (English)

    颜建平; 周成合; 吉庆刚; 耿蓉霞

    2011-01-01

    咔唑类化合物是一类重要的芳杂环化合物,在抗细菌、抗真菌和抗病毒方面具有较好的应用前景,深受研究者关注.有关咔唑类化合物的研究包括天然生物碱的分离、全合成、结构修饰及其抗微生物活性研究与开发.本文结合本课题组的研究,综述了近年来咔唑类化合物的抗微生物活性及其构效关系的研究进展.%Carbazole compounds, a class of important aromatic heterocyclic compounds, possess extensive application prospect as antibacterial, antifungal and antiviral agents, and thus receive increasing attention. The researches on carbazole compounds include isolation and total synthesis of naturally carbazole alkaloids, structure modification of carbazole derivatives and investigation on their recovery of antimicrobial activities. This paper reviews recent research advances in carbazole compounds and their antimicrobial activities. The structure-activity relationship is also discussed.

  3. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display...... a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because...... the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially...

  4. Serological studies on chloridazon-degrading bacteria.

    Science.gov (United States)

    Layh, G; Böhm, R; Eberspächer, J; Lingens, F

    1983-01-01

    Agglutination tests and immunofluorescence tests with antisera against four strains of chloridazon-degrading bacteria revealed the serological uniformity of a group of 22 chloridazon-degrading bacterial strains. No serological relationship could be found between chloridazon-degrading bacteria and representatives of other Gram-negative bacteria. This was demonstrated by agglutination tests, including testing of the antiserum against Acinetobacter calcoaceticus, and by immunofluorescence tests, including testing of the sera against Pseudomonas and Acinetobacter strains. The tests were performed with 31 representatives of different Gram-negative bacteria, and with 22 strains of chloridazon-degrading bacteria as antigens. Differences in the extent of agglutination reactions and antibody titres among chloridazon-degrading bacterial strains together with cross-adsorption xperiments, suggest a rough classification of chloridazon-degrading bacteria into two subgroups. On the basis of immunofluorescence data, a linkage-map was worked out to represent serological relationships in the group of chloridazon-degrading strains.

  5. Chronic Pseudomonas aeruginosa cervical osteomyelitis

    Directory of Open Access Journals (Sweden)

    Sujeet Kumar Meher

    2016-01-01

    Full Text Available Pseudomonas aeruginosa is a rare cause of osteomyelitis of the cervical spine and is usually seen in the background of intravenous drug use and immunocompromised state. Very few cases of osteomyelitis of the cervical spine caused by pseudomonas aeruginosa have been reported in otherwise healthy patients. This is a case presentation of a young female, who in the absence of known risk factors for cervical osteomyelitis presented with progressively worsening neurological signs and symptoms.

  6. Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Tesla, Rachel; Wolf, Hamilton Parker; Xu, Pin; Drawbridge, Jordan; Estill, Sandi Jo; Huntington, Paula; McDaniel, Latisha; Knobbe, Whitney; Burket, Aaron; Tran, Stephanie; Starwalt, Ruth; Morlock, Lorraine; Naidoo, Jacinth; Williams, Noelle S; Ready, Joseph M; McKnight, Steven L; Pieper, Andrew A

    2012-10-16

    We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the hippocampal dentate gyrus. We have further found that chemicals having efficacy in this in vivo screening assay also protect dopaminergic neurons of the substantia nigra following exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a mouse model of Parkinson disease. Here, we provide evidence that an active analog of P7C3, known as P7C3A20, protects ventral horn spinal cord motor neurons from cell death in the G93A-SOD1 mutant mouse model of amyotrophic lateral sclerosis (ALS). P7C3A20 is efficacious in this model when administered at disease onset, and protection from cell death correlates with preservation of motor function in assays of walking gait and in the accelerating rotarod test. The prototypical member of this series, P7C3, delays disease progression in G93A-SOD1 mice when administration is initiated substantially earlier than the expected time of symptom onset. Dimebon, an antihistaminergic drug with significantly weaker proneurogenic and neuroprotective efficacy than P7C3, confers no protection in this ALS model. We propose that the chemical scaffold represented by P7C3 and P7C3A20 may provide a basis for the discovery and optimization of pharmacologic agents for the treatment of ALS.

  7. Oxadiazole-carbazole polymer (POC)-Ir(ppy)3 tunable emitting composites

    Science.gov (United States)

    Bruno, Annalisa; Borriello, Carmela; Di Luccio, Tiziana; Sessa, Lucia; Concilio, Simona; Haque, Saif A.; Minarini, Carla

    2017-04-01

    POC polymer is an oxadiazole-carbazole copolymer we have previously synthetized and established as light emitting material in Organic Light Emitting Devices (OLEDs), although POC quantum yield emission efficiency and color purity still need to be enhanced. On the other hand, tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3) complexes, namely Ir(ppy)3 are among the brightest luminophores employed in green light emitting devices. Our aim, in this work, is to take advantage of Ir(ppy)3 bright emission by combining the Ir complex with blue emitting POC to obtain tunable light emitting composites over a wide range of the visible spectrum. Here we have investigated the optical proprieties POC based nanocomposites with different concentrations of Ir(ppy)3, ranging from 1 to 10 wt%. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to the dopants, resulting in white-emitting composites. The most intense and stable emission has been found when POC was doped with about 5 wt% concentration of Ir(ppy)3.

  8. SYNTHESIS AND CHARACTERIZATION OF NOVEL BIPOLAR PPV-BASED COPOLYMER CONTAINING TRIAZOLE AND CARBAZOLE UNITS

    Institute of Scientific and Technical Information of China (English)

    Ze Liu; Li-xiang Wang; Xia-bin Jing; Fo-song Wang

    2001-01-01

    Two new blue light-emitting PPV-based conjugated copolymers containing both an electron-withdrawing unit (triazole-TAZ) and electron-rich moieties (carbazole-CAR and bicarbazole-BCAR) were prepared by Wittig condensation polymerization between the triazole diphosphonium salt and the corresponding dialdehyde monomers. Their structures and properties were characterized by FT-IR, TGA, DSC, UV-Vis, PL spectroscopy and electrochemical measurements. The resulting copolymers are soluble in common organic solvents and thermally stable with a Ts of 147C for TAZ-CAR-PPV and of 157C for TAZ-BCAR-PPV. The maximum photoluminescence wavelengths of TAZ-CAR-PPV and TAZ-BCAR-PPV film appear at 460 nm and 480 nm, respectively. Cyclic voltammetry measurement demonstrates that TAZ-BCAR-PPV has good electrochemical reversibility, while TAZ-CAR-PPV exhibits the irreversible redox process. The triazole unit was found to be an effective π-conjugation interrupter and can play the rigid spacer role in determining the emission colour of the resulting copolymer.

  9. NOVEL RED LIGHT-EMITTING POLYMERS BASED ON 2,7-CARBAZOLE AND THIOPHENE DERIVATIVES

    Institute of Scientific and Technical Information of China (English)

    Ran-sheng Liu; Wen-jin Zeng; Bin Du; Wei Yang; Qiong Hou; Wei Shi; Yong Zhang; Yong Cao

    2008-01-01

    A series of conjugated copolymers derived from 9-ethylhexyl-2,7-carbazole (Cz) and 4,7-di(4-hexylthien-2-yl)-2,1,3-benzothiadiazole (DHTBT) was synthesized by Suzuki polycondensation. The photo- and electro-luminescentproperties of these polymers were investigated. Efficient energy transfer from the Cz segment to the DHTBT unit occurseven if the DHTBT content as low as 1 mol%. PL emission was red-shifted significantly from 645 nm to 700 nm with theincrease in DHTBT content by 1-50 mol%. PL efficiencies decreased with the increase in DHTBT content in the polymersfrom 55% for PCzDHTBT1 gradually down to 7% for PCzDHTBT50. EL emission of these polymers red-shifted from640 nm to 690 nm when the DHTBT content increased from 1 mol% to 50 mol%. The highest external quantum efficiencywas 1.67% for PCzDHTBT25 with the maximum luminescence of 870 cd/m,'2 in the device configuration of ITO/PEDOT:PSS/polymer/PFN/Ba/Al. The enhancement of device performances could be due to the improved electron injection byinserting the amino-containing polyfluorene (PFN) layer. These polymers are promising candidates as a red emitter in thefull-color polymer light emitting diodes (PLEDs).

  10. Quickly Updatable Hologram Images Using Poly(N-vinyl Carbazole (PVCz Photorefractive Polymer Composite

    Directory of Open Access Journals (Sweden)

    Wataru Sakai

    2012-08-01

    Full Text Available Quickly updatable hologram images using photorefractive (PR polymer composite based on poly(N-vinyl carbazole (PVCz is presented. PVCz is one of the pioneer materials of photoconductive polymers. PR polymer composite consists of 44 wt % of PVCz, 35 wt % of 4-azacycloheptylbenzylidene-malonitrile (7-DCST as a nonlinear optical dye, 20 wt % of carbazolylethylpropionate (CzEPA as a photoconductive plasticizer and 1 wt % of 2,4,7-trinitro-9-fluorenone (TNF as a sensitizer. PR composite gives high diffraction efficiency of 68% at E = 45 V μm−1. Response speed of optical diffraction is the key parameter for real-time 3D holographic display. The key parameter for obtaining quickly updatable holographic images is to control the glass transition temperature lower enough to enhance chromophore orientation. Object image of the reflected coin surface recorded with reference beam at 532 nm (green beam in the PR polymer composite is simultaneously reconstructed using a red probe beam at 642 nm. Instead of using a coin object, an object image produced by a computer was displayed on a spatial light modulator (SLM and used for the hologram. The reflected object beam from an SLM was interfered with a reference beam on PR polymer composite to record a hologram and simultaneously reconstructed by a red probe beam.

  11. New chromophores based on combination of ethylenedioxythiophene and carbazole fragments: synthesis and optoelectronic properties

    Science.gov (United States)

    Bakiev, A. N.; Mayorova, O. A.; Gorbunov, A. A.; Lunegov, I. V.; Shklyaeva, E. V.; Abashev, G. G.

    2016-12-01

    Two new D-π-A chromophores composed of an electron-donating carbazole unit linked through π- bridges, bearing 3,4-ethylenedioxythiophene (EDOT) moiety, with an electron withdrawing dicyanovinyl group (DCV) were successfully synthesized involving Suzuki or Heck cross-coupling and Knöevenagel reactions as the key steps. The obtained compounds absorb light over a broad spectral range, including the visible spectrum. The HOMO/LUMO energies and band gap energy values (Eg) were calculated on the basis of the experimental optical and electrochemical data: HOMO, LUMO, Eg (eV), -5.51, -3.14, 2.37 (4), -5.34, -3.14, 2.20 (7). The presence of the HC=CH unit in compound 7 resulted in the increase of the HOMO energy level, the decrease of a band gap value and red shifts of the absorption and emission bands in comparison with those of 4. Large Stokes shifts and broadband luminescence inherent to both chromophores suggest their use as materials for luminescent solar collectors (LSCs). The obtained compounds demonstrated good solubility and suitable thin-film forming properties. For this reason, they may be suitable for solution-processable photovoltaic applications.

  12. Carbazole based electrochromic polymers with benzoazole units: Effect of heteroatom variation on electrochromic performance

    Directory of Open Access Journals (Sweden)

    C. Doyranli

    2016-09-01

    Full Text Available A series of carbazole-based polymers were synthesized via Suzuki polymerization between N-(2-ethylhexylcarbazole-3,6-bis(ethyleneboronate (Cbz and dibromobenzazole unit. Three different polymers, PCBN, PCBS and PCBSe were obtained from 4,7-dibromo-2-hexyl-2H-benzotriazole (BN, 4,7-dibromo-2,1,3-benzothiadiazole- (BS and 4,7-dibromo-2,1,3-benzoselenadiazole (BSe, respectively. It is observed that, the variation of heteroatoms (N,S and Se on the benzazole unit have most important effect on electro-optic properties of the PCBX polymers. Neutral state color of the polymer films and their electrochromic performances are also influenced. Among the synthesized polymers, the PCBS bearing 2,1,3-benzothiadiazole as acceptor units has a broad absorption and 50% of ΔT in the near-IR regime at the oxidized state. This property of PCBS is a great advantage for near-IR electrochromic applications.

  13. 2-(4-Chloro-2-nitrophenyl-9-phenylsulfonyl-9H-carbazole-3-carbaldehyde

    Directory of Open Access Journals (Sweden)

    S. Gopinath

    2013-09-01

    Full Text Available In the title compound, C25H15ClN2O6S, the carbazole ring system is essentially planar, with a maximum deviation of 0.152 (3 Å for the C atom to which the 4-chloro-2-nitrophenyl ring is attached. Its mean plane is almost orthogonal to the phenylsulfonyl and nitrophenyl rings, making dihedral angles of 82.64 (14 and 79.89 (13°, respectively. The N atom of the nitro group deviates by 0.032 (3 Å from the benzene ring to which it is attached. The molecular structure features intramolecular O—H...O and C—H...O hydrogen bonds, which generate three S(6 ring motifs. In the crystal, molecules are linked by C—H...O hydrogen bonds, which generate C(6 and C(9 chains running in the [100] and [010] directions, respectively, forming a two-dimensional network lying parallel to (001. There are also R43(28 supramolecular graph-set ring motifs enclosed within these networks.

  14. Study on the Synthesis and Spectra of a Novel Kind of Carbozole Benzothiazole Indole Styryl Cyanine Dye with a Carbazole Bridged Chain.

    Science.gov (United States)

    Fei, Xuening; Hao, Yachao; Gu, Yingchun; Li, Chao; Yu, Lu

    2014-03-01

    Based on the frequently-used cyanine dye probe thiazole orange (TO) and Cy3, a novel kind of styryl cyanine dye was designed and synthesized. Carbazole was inserted into the structures of two cyanine dyes, TO and Cy3, to act as a bridge to link the benzothiazole and indole. This modification resulted in a novel kind of carbozole benzothiazole indole cyanine dye with a carbazole-bridged chain. The dyes were characterized by HNMR and MS. The spectra of the novel dyes were also studied and the results showed that the fluorescence wavelength of novel carbazole benzothiazole indole cyanine dye shifted red, the Stokes shift and Fluorescence quantum yields increased and the fluorescence intensity was enhanced compared to that of TO. These results indicated that the novel dye could be used as an excellent fluorescent probe in biological labeling.

  15. Novel high band gap pendant-borylated carbazole polymers with deep HOMO levels through direct +N=B- interaction for organic photovoltaics

    DEFF Research Database (Denmark)

    Brandt, Rasmus G.; Sveegaard, Steffen G.; Xiao, Manjun;

    2016-01-01

    '] dithiophene) (P(3,6-BCBDT)) and poly(3,6-(N-di(2,4,6-trimethyl)phenylboryl-carbazole)-alt-3,3 '''- didodecyl-2,2': 5',2 '': 5 '',2 '''-quaterthiophene) (P(3,6-BCQT)), which result in ambipolarity, high electron affinity, and deep HOMO levels. The quasi-donor-acceptor nature of the two polymers was confirmed......In this communication, we investigate the direct and still conjugated intramolecular +N=B- interactions in novel high band gap borylated carbazole containing polymers, namely, poly(3,6-(N-di(2,4,6-trimethyl)-phenylboryl-carbazole)-alt- 4,8-di(5-(2-ethylhexyl)thiophene-2-yl)benzo[1,2-b: 4,5-b...

  16. Synthesis and spectra of a kind of novel longer-wavelength benzoxazole indole styryl cyanine dye with a carbazole-bridged chain.

    Science.gov (United States)

    Fei, Xuening; Gu, Yingchun; Li, Chao; Liu, Yuru; Yu, Lu

    2013-01-01

    Based on cyanine dye probe oxazole yellow (YO) and Cy(3), a series of novel styryl cyanine dyes were designed and synthesized. Carbazole was inserted into the structures of YO and Cy(3) to act as a bridge to link the benzoxazole and indole group. This modification resulted in a novel kind of benzoxazole indole styryl cyanine dye with a carbazole-bridged chain. The dyes were characterized by (1)HNMR and MS. The spectra of the novel dyes were also performed and the results showed that the maximum emission wavelength of the carbazole styryl cyanine dye was shifted red, the Stokes shift increased and the fluorescence intensity enhanced compared with those of YO and Cy(3). These results indicated that the novel dye could be used as an excellent fluorescent probe in biological labeling.

  17. 3-苯并嚼唑-6-甲酰基咔唑的合成%Synthesis of 3-benzoxazole-6-formyl Carbazole

    Institute of Scientific and Technical Information of China (English)

    杨旭; 费学宁; 谷迎春; 李超

    2011-01-01

    Two novel 3-benzoxazole-6-formyl carbazole derivatives were synthesized from carbazole by alkylation, formylation, oxidation of carbazole schiff bases and formylation. The cqmpounds' structures were characterized by 1H NMR and MS and their fluorescent spectra were preliminarily studied.%以咔唑为原料,经过烷基化、甲酰化、咔唑席夫碱氧化、甲酰化,合成了2个3-苯并嗯唑-6-甲酰基咔唑衍生物,其结构经1HNMR和MS表征,并初步研究了其荧光光谱.

  18. Synthesis of Novel 1-Substituted and 1,9-Disubstituted-1,2,3,4-tetrahydro-9H-Carbazole Derivatives as Potential Anticancer Agents

    Directory of Open Access Journals (Sweden)

    H. I. El-Diwani

    2000-10-01

    Full Text Available Condensation of 1-acetyl-1,2,3,4-tetrahydro-9H-carbazole (2 with some amino compounds furnished the corresponding imino derivatives 3a-e. Compound 3a reacted with chloroacetic acid and underwent cyclization to give the thiazolidine derivative 5. Also, treatment of 3c with thionyl chloride caused cyclization to yield the [1,2,6]thiadiazino derivative 6, which gave the corresponding N-formyl derivative 7 upon heating with ethyl formate. In addition, interaction of 3d with ethyl cyanoacetate yielded the monoamide of malonic acid derivative 8. Acylation of carbazole 1 with succinoyl chloride or phenylacetyl choride produced the corresponding azepine (11 and 1,9-diphenyl acetyl derivatives (14, respectively. Compounds 11, 14 were further reacted to give the carbazole derivatives 12, 13 and 15a,b. The cytotoxic activity for some of the prepared compounds against breast cancer B20 is discussed.

  19. Draft Genome Sequence of Pseudomonas aeruginosa Strain N002, Isolated from Crude Oil-Contaminated Soil from Geleky, Assam, India

    Science.gov (United States)

    Roy, Abhjit Sarma; Baruah, Reshita; Gogoi, Dhrubajyoti; Borah, Maina

    2013-01-01

    Here, we report the draft genome sequence of crude oil-degrading Pseudomonas aeruginosa strain N002, isolated from a crude oil-polluted soil sample from Geleky, Assam, India. Multiple genes potentially involved in crude oil degradation were identified. PMID:23405324

  20. Pseudomonas frederiksbergensis sp. nov., isolated from soil at a coal gasification site.

    Science.gov (United States)

    Andersen, S M; Johnsen, K; Sørensen, J; Nielsen, P; Jacobsen, C S

    2000-11-01

    Phenotypic and genotypic characterization indicated that a group of 29 closely related phenanthrene-degrading bacteria from a coal gasification site in Frederiksberg, Copenhagen, Denmark, belonged to the genus Pseudomonas. The strains were isolated at two sampling occasions 2 years apart. The isolates were phenotypically different from any known species of the genus Pseudomonas and were therefore subject to further identification. Colonies were smooth and pale yellowish and did not produce pigments fluorescent in UV light when grown on King's B agar. Cells were rod-shaped, approximately 0.5-0.8 x 1.5-3.0 microm, and grew at 4 and 30 degrees C, but not 37 degrees C. The bacteria were oxidase- and catalase-positive, accumulated poly-beta-hydroxybutyrate and denitrified, but did not utilize D-xylose. The mean G+C content was 59.6 mol%. Phenotypic data and 16S rDNA sequence data information for Pseudomonas amygdali and Pseudomonas corrugata, and 16S rDNA sequence data for Pseudomonas chlororaphis and Pseudomonas syringae showed close relationships to these strains. However, DNA-DNA hybridization data showed that the isolates belong to a new species, for which the name Pseudomonas frederiksbergensis sp. nov. is proposed. The type strain is JAJ28T (DSM 13022T).

  1. Synthesis, photophysics, electrochemistry, thermal stability and electroluminescent performances of a new europium complex with bis(β-diketone) ligand containing carbazole group.

    Science.gov (United States)

    Liu, Jian; Liang, Quan-Bin; Wu, Hong-Bin

    2016-09-07

    We synthesized a new europium complex [Eu(ecbpd)3 (Phen)] with bis(β-diketone) ligand containing a carbazole group, in which ecbpd and Phen are dehydro-3,3'-(9-ethyl-9H-carbazole-3,6-diyl)bis(1-phenylpropane-1,3-dione) and 1,10-phenanthroline, respectively. Its UV/vis and photoluminescent spectra, quantum yield, luminescence lifetime, electrochemistry, thermal stability and electroluminescent performances were studied. This europium complex showed low efficiency luminescence, which is probably due to the mismatching energy levels of its ligand and Eu(3)(+) , as well as the double Eu(3)(+) core resonance.

  2. One-Pot Synthesis of N-(α-Peroxy)Indole/Carbazole via Chemoselective Three-Component Condensation Reaction in Open Atmosphere

    KAUST Repository

    Wang, Xinbo

    2015-11-06

    A facile one-pot synthesis of N-(α-peroxy)indole and N-(α-peroxy)carbazole has been developed using metal-free, organo-acid-catalyzed three-component condensation reactions of indole/carbazole, aldehyde, and peroxide. Based on the reaction discovered, a new synthetic proposal for Fumitremorgin A and Verruculogen is introduced. Such a protocol could be easily handled and scaled up in an open atmosphere with a wide substrate scope, enabling the construction of a new molecule library.

  3. A New Star-shaped Carbazole Derivative with Polyhedral Oligomeric Silsesquioxane Core: Crystal Structure and Unique Photoluminescence Property.

    Science.gov (United States)

    Xu, Zixuan; Yu, Tianzhi; Zhao, Yuling; Zhang, Hui; Zhao, Guoyun; Li, Jianfeng; Chai, Lanqin

    2016-01-01

    A new inorganic–organic hybrid material based on polyhedral oligomeric silsesquioxane (POSS) capped with carbazolyl substituents, octakis[3-(carbazol-9-yl)propyldimethylsiloxy]-silsesquioxane (POSS-8Cz), was successfully synthesized and characterized. The X-ray crystal structure of POSS-8Cz were described. The photophysical properties of POSS-8Cz were investigated by using UV–vis,photoluminescence spectroscopic analysis. The hybrid material exhibits blue emission in the solution and the solid film.The morphology and thermal stablity properties were measured by X-ray diffraction (XRD) and TG-DTA analysis.

  4. Indolo[2,3-b]carbazoles with tunable ground states: How Clar's aromatic sextet determines the singlet biradical character

    KAUST Repository

    Luo, Ding

    2014-01-01

    Polycyclic hydrocarbons (PHs) with a singlet biradical ground state have recently attracted extensive interest in physical organic chemistry and materials science. Replacing the carbon radical center in the open-shell PHs with a more electronegative nitrogen atom is expected to result in the more stable aminyl radical. In this work, two kinetically blocked stable/persistent derivatives (1 and 2) of indolo[2,3-b]carbazole, an isoelectronic structure of the known indeno[2,1-b]fluorene, were synthesized and showed different ground states. Based on variable-temperature NMR/ESR measurements and density functional theory calculations, it was found that the indolo[2,3-b]carbazole derivative 1 is a persistent singlet biradical in the ground state with a moderate biradical character (y0 = 0.269) and a small singlet-triplet energy gap (ΔES-T ≅ -1.78 kcal mol-1), while the more extended dibenzo-indolo[2,3-b]carbazole 2 exhibits a quinoidal closed-shell ground state. The difference can be explained by considering the number of aromatic sextet rings gained from the closed-shell to the open-shell biradical resonance form, that is to say, two for compound 1 and one for compound 2, which determines their different biradical characters. The optical and electronic properties of 2 and the corresponding aromatic precursors were investigated by one-photon absorption, transient absorption and two-photon absorption (TPA) spectroscopies and electrochemistry. Amphoteric redox behaviour, a short excited lifetime and a moderate TPA cross section were observed for 2, which can be correlated to its antiaromaticity and small biradical character. Compound 2 showed high reactivity to protic solvents due to its extremely low-lying LUMO energy level. Unusual oxidative dimerization was also observed for the unblocked dihydro-indolo[2,3-b]carbazole precursors 6 and 11. Our studies shed light on the rational design of persistent aminyl biradicals with tunable properties in the future. This journal

  5. DDE remediation and degradation.

    Science.gov (United States)

    Thomas, John E; Ou, Li-Tse; All-Agely, Abid

    2008-01-01

    DDT and its metabolites, DDD and DDE, have been shown to be recalcitrant to degradation. The parent compound, DDT, was used extensively worldwide starting in 1939 and was banned in the United States in 1973. The daughter compound, DDE, may result from aerobic degradation, abiotic dehydrochlorination, or photochemical decomposition. DDE has also occurred as a contaminant in commercial-grade DDT. The p,p'-DDE isomer is more biologically active than the o,p-DDE, with a reported half-life of -5.7 years. However, when DDT was repeatedly applied to the soil, the DDE concentration may remain unchanged for more than 20 yr. Remediation of DDE-contaminated soil and water may be done by several techniques. Phytoremediation involves translocating DDT, DDD, and DDE from the soil into the plant, although some aquatic species (duckweed > elodea > parrot feather) can transform DDT into predominantly DDD with some DDE being formed. Of all the plants that can uptake DDE, Cucurbita pepo has been the most extensively studied, with translocation values approaching "hyperaccumulation" levels. Soil moisture, temperature, and plant density have all been documented as important factors in the uptake of DDE by Cucurbita pepo. Uptake may also be influenced positively by amendments such as biosurfactants, mycorrhizal inoculants, and low molecular weight organic acids (e.g., citric and oxalic acids). DDE microbial degradation by dehalogenases, dioxygenases, and hydrolases occurs under the proper conditions. Although several aerobic degradation pathways have been proposed, none has been fully verified. Very few aerobic pure cultures are capable of fully degrading DDE to CO2. Cometabolism of DDE by Pseudomonas sp., Alicaligens sp., and Terrabacter sp. grown on biphenyl has been reported; however, not all bacterial species that produce biphenyl dioxygenase degraded DDE. Arsenic and copper inhibit DDE degradation by aerobic microorganisms. Similarly, metal chelates such as EDTA inhibit the

  6. Behaviour of marine oil-degrading bacterial populations in a continuous culture system

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; David, J.J.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

    In pursuit of developing an oil-degrading microbial consortium, we used the principle of "plasmid assisted molecular breeding" (PAMB) in a continuous culture system. Three marine bacteria, Pseudomonas putida, Brevibacterium epidermidis...

  7. Biodegradation of Chlorpyrifos by Pseudomonas Resinovarans Strain AST2.2 Isolated from Enriched Cultures.

    Directory of Open Access Journals (Sweden)

    Anish Sharma*,

    2016-04-01

    Full Text Available A bacterial strain AST2.2 with chlorpyrifos degrading ability was isolated by enrichment technique from apple orchard soil with previous history of chlorpyrifos use. Based on the morphological, biochemical tests and 16S rRNA sequence analysis, AST2.2 strain was identified as Pseudomonas resinovarans. The strain AST2.2 utilized chlorpyrifos as the sole source of carbon and energy. This strain exhibited growth upto 400mg/l concentration of chlorpyrifos and exhibited high extracellular organophosphorus hydrolase (OPH activity. Gas chromatography-flame ionization detector (GC-FID studies revealed that Pseudomonas resinovarans AST2.2 degraded 43.90 % of chlorpyrifos (400 mg/l within 96 hrs. Intermediates of chlorpyrifos degradation were identified using GC-MS. This strain have potential to degrade chlorpyrifos and thus can be used for bioremediation and ecological restoration of sites contaminated with chlorpyrifos.

  8. Hot Tub Rash (Pseudomonas Dermatitis/Folliculitis)

    Science.gov (United States)

    ... Español [PDF - 1 page] "Hot Tub Rash" ( Pseudomonas Dermatitis / Folliculitis) If contaminated water comes in contact ... is often caused by infection with the germ Pseudomonas aeruginosa . This germ is common in the environment ( ...

  9. Biodegradation of sulfanilic acid by Pseudomonas paucimobilis.

    Science.gov (United States)

    Perei, K; Rákhely, G; Kiss, I; Polyák, B; Kovács, K L

    2001-01-01

    An aerobic bacterium, isolated from a contaminated site, was able to degrade sulfanilic acid (4-aminobenzenesulfonic acid) and was identified as Pseudomonas paucimobilis. The isolate could grow on sulfanilic acid (SA) as its sole carbon and nitrogen source and metabolized the target compound to biomass. The bioconversion capacity depended on the sulfanilic acid concentration; greater than 98% elimination of the hazardous compound was achieved at low (10 mM) sulfanilic acid concentration, and the yield was greater than 70% at 50 mM concentration of the contaminant. The maximum conversion rate was 1.5 mmol sulfanilic acid/h per mg wet cells at 30 degrees C. Ca-alginate-phytagel proved a good matrix for immobilization of P. paucimobilis, with essentially unaltered biodegradation activity. Removal of sulfanilic acid from contaminated industrial waste water was demonstrated. SDS-PAGE analysis of the crude extract revealed novel proteins appearing upon induction with sulfanilic acid and related compounds, which indicated alternative degradation mechanisms involving various inducible enzymes.

  10. Neuroprotective efficacy of aminopropyl carbazoles in a mouse model of Parkinson disease.

    Science.gov (United States)

    De Jesús-Cortés, Héctor; Xu, Pin; Drawbridge, Jordan; Estill, Sandi Jo; Huntington, Paula; Tran, Stephanie; Britt, Jeremiah; Tesla, Rachel; Morlock, Lorraine; Naidoo, Jacinth; Melito, Lisa M; Wang, Gelin; Williams, Noelle S; Ready, Joseph M; McKnight, Steven L; Pieper, Andrew A

    2012-10-16

    We previously reported the discovery of P7C3, an aminopropyl carbazole having proneurogenic and neuroprotective properties in newborn neural precursor cells of the dentate gyrus. Here, we provide evidence that P7C3 also protects mature neurons in brain regions outside of the hippocampus. P7C3 blocks 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-mediated cell death of dopaminergic neurons in the substantia nigra of adult mice, a model of Parkinson disease (PD). Dose-response studies show that the P7C3 analog P7C3A20 blocks cell death with even greater potency and efficacy, which parallels the relative potency and efficacy of these agents in blocking apoptosis of newborn neural precursor cells of the dentate gyrus. P7C3 and P7C3A20 display similar relative effects in blocking 1-methyl-4-phenylpyridinium (MPP(+))-mediated death of dopaminergic neurons in Caenorhabditis elegans, as well as in preserving C. elegans mobility following MPP(+) exposure. Dimebon, an antihistaminergic drug that is weakly proneurogenic and neuroprotective in the dentate gyrus, confers no protection in either the mouse or the worm models of PD. We further demonstrate that the hippocampal proneurogenic efficacy of eight additional analogs of P7C3 correlates with their protective efficacy in MPTP-mediated neurotoxicity. In vivo screening of P7C3 analogs for proneurogenic efficacy in the hippocampus may thus provide a reliable means of predicting neuroprotective efficacy. We propose that the chemical scaffold represented by P7C3 and P7C3A20 provides a basis for optimizing and advancing pharmacologic agents for the treatment of patients with PD.

  11. Crystal structure of poly[[[μ4-5-(9H-carbazol-9-ylisophthalato][μ3-5-(9H-carbazol-9-ylisophthalato]bis(dimethylformamide(methanoldizinc] dimethylformamide monosolvate

    Directory of Open Access Journals (Sweden)

    Liubov M. Lifshits

    2015-08-01

    Full Text Available The structure of the polymeric title compound, {[Zn2(C20H11NO42(C3H7NO2(CH3OH]·C3H7NO}n, comprises carbazolylisophthalate moieties connecting dimetallic tetracarboxylate zinc secondary building units (SBUs parallel to [100] and [010], leading to a layer-like arrangement parallel to (001. Each SBU consists of two Zn atoms in slightly distorted tetrahedral and octahedral coordination environments [Zn...Zn = 3.5953 (6 Å]. Three carboxylate groups bridge the two Zn atoms in a μ2-O:O′ mode, whereas the fourth coordinates through a single carboxylate O atom (μ1-O. The O atoms of two dimethylformamide (DMF and one methanol molecule complete the Zn coordination spheres. The methanol ligand interacts with the noncoordinating DMF molecule via an O—H...O hydrogen bond of medium strength. Carbazoles between the layers interdigitate through weak C—H....π interactions to form a laminar solid stacked along [010]. Two kinds of C—H...π interactions are present, both with a distance of 2.64 Å, between the H atoms and the centroids, and a third C—H...π interaction, where the aromatic H atom is located above the carbazole N-atom lone pair (H...N = 2.89 Å. Several C—H...O interactions occur between the coordinating DMF molecule, the DMF solvent molecule, and ligating carboxylate O atoms.

  12. Isolation and characterization of endosulfan-degrading bacteria from contaminated agriculture soils

    Directory of Open Access Journals (Sweden)

    Mehdi Hassanshahian

    2016-04-01

    Full Text Available Objective: To isolate and characterize endosulfan-degrading bacteria from Kerman pistachio orchards. Methods: Endosulfan-degrading bacteria were enriched in Bushnell-Hass medium. Identification and sequencing of prevalent degrading strains was performed by using PCR based on amplifying 16S rDNA. Results: The results showed that the soils of pistachio orchards have some degrading bacteria that are suitable for elimination of endosulfan from soils and the environment. Four endosulfandegrading bacteria strains belong to Achromobacter xylosoxidans (strain EN3, Pseudomonas azotoformans (strain EN4, Pseudomonas brassicacearum (strain EN7 and Pseudomonas thivervalensis (strain EN8, respectively. The best degrading strain (EN7, up to 100 mg/L, illustrated a good growth, whereas the growth was reduced in concentration higher than 100 mg/L. The results of gas chromatography confirmed the decomposition of organic pesticide by degrading-bacteria. Conclusions: By using these strains and other biological reclamation methods we can eliminate bio-environmental problems.

  13. Isolation and characterization of an alginase from mucoid strains of Pseudomonas aeruginosa.

    OpenAIRE

    Linker, A.; Evans, L. R.

    1984-01-01

    Strains of Pseudomonas aeruginosa which produce an alginate-like slime polysaccharide were shown to also synthesize an intracellular enzyme which can degrade these polysaccharides and the seaweed alginic acids. The enzyme acts as an eliminase introducing delta 4,5 unsaturation into the uronic acid moiety. It appears to be a polymannuronide lyase which degrades the polysaccharides, depending on their uronic acid composition, to a series of oligosaccharides, the smallest of which is a disacchar...

  14. CLONING AND SEQUENCING OF PSEUDOMONAS GENES DETERMINING SODIUM DODECYL-SULFATE BIODEGRADATION

    NARCIS (Netherlands)

    DAVISON, J; BRUNEL, F; PHANOPOULOS, A; PROZZI, D; TERPSTRA, P

    1992-01-01

    The nucleotide sequences of two genes involved in sodium dodecyl sulfate (SDS) degradation, by Pseudomonas, have been determined. One of these, sdsA, codes for an alkyl sulfatase (58 957 Da) and has similarity (31.8% identity over a 201-amino acid stretch) to the N terminus of a predicted protein of

  15. Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-09-01

    Full Text Available Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE, which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8, accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA. When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition.

  16. Molecular modeling and experimental studies on structure and NMR parameters of 9-benzyl-3,6-diiodo-9H-carbazole

    DEFF Research Database (Denmark)

    Radula-Janik, Klaudia; Kupka, Teobald; Ejsmont, Krzysztof;

    2015-01-01

    A combined experimental and theoretical study has been performed on 9-benzyl-3,6-diiodo-9H-carbazole. Experimental X-ray (100.0 K) and room-temperature 13C NMR studies were supported by advanced density functional theory (DFT) calculations. The non relativistic structure optimization was performe...

  17. Novel Hole Transporting Materials Based on 4-(9H-Carbazol-9-yltriphenylamine Derivatives for OLEDs

    Directory of Open Access Journals (Sweden)

    Quynh Pham Bao Nguyen

    2014-09-01

    Full Text Available During the past few years, organic light emitting diodes (OLEDs have been increasingly studied due to their emerging applicability. However, some of the properties of existing OLEDs could be improved, such as their overall efficiency and durability; these aspects have been addressed in the current study. A series of novel hole-transporting materials (HTMs 3a–c based on 4-(9H-carbazol-9-yltriphenylamine conjugated with different carbazole or triphenylamine derivatives have been readily synthesized by Suzuki coupling reactions. The resulting compounds showed good thermal stabilities with high glass transition temperatures between 148 and 165 °C. The introduction of HTMs 3b and 3c into the standard devices ITO/HATCN/NPB/HTMs 3 (indium tin oxide/dipyrazino(2,3-f:2ꞌ,3ꞌ-hquinoxaline 2,3,6,7,10,11-hexacarbonitrile/N,Nꞌ-bis(naphthalen-1-yl-N,Nꞌ-bis(phenyl-benzidine/HTMs/CBP (4,4ꞌ-Bis(N-carbazolyl-1,1ꞌ-biphenyl: 5% Ir(ppy3/Bphen/LiF/Al (tris[2-phenylpyridinato-C2,N]iridium(III/4,7-diphenyl-1,10-phenanthroline/LiF/Al resulted in significantly enhanced current, power, and external quantum efficiencies (EQE as compared to the reference device without any layers of HTMs 3.

  18. EFFICIENT WHITE EMITTING COPOLYMERS BASED ON BIPOLAR FLUORENE-co-DIBENZOTHIOPHENE-S,S-DIOXIDE-co-CARBAZOLE BACKBONE

    Institute of Scientific and Technical Information of China (English)

    Lei Ying; Yan-hu Li; Cai-hong Wei; Min-quan Wang; Wei Yang; Hong-bin Wu; Yong Cao

    2013-01-01

    Efficient white light emitting polymers were synthesized based on poly(9,9-dioctylfluorene-co-dibenzothiopheneS,S-dioxide) as blue emitter and a bisphenylamine functionalized 2,1,3-benzothiadiazole (DPABT) as red emitter.It was found that the incorporation of hole-transporting carbazole moiety into polymer main chain could effectively reduce the hole injection barriers,which can lead to distinctly improved charge balance in the emissive layer.Additionally,the holetransporting carbazole units may form efficient bipolar host with electron-transporting dibenzothiophene-S,S-dioxide units.The white light emitting diodes based on single polymer PFSOCzDPABT showed the maximum luminous efficiency of 3.3 cd/A with the maximum luminance of 10282 cd/m2,and the luminous efficiency showed only 24% roll off at current density of 400 mA/cm2.These Commission Intemationale d'Enclairage (CIE) coordinates of the devices changed slightly with the driving voltages increasing from 8 V to 12 V,and were very close to National Television System Committee (NTSC) standard white light emission of (0.33,0.33).The results indicated that the incorporating bipolar host and low band gap DPABT unit was a promising way to achieve efficient single white light emitting copolymers.

  19. Ultrafast intramolecular charge transfer with N-(4-cyanophenyl)carbazole. Evidence for a LE precursor and dual LE + ICT fluorescence.

    Science.gov (United States)

    Galievsky, Victor A; Druzhinin, Sergey I; Demeter, Attila; Mayer, Peter; Kovalenko, Sergey A; Senyushkina, Tamara A; Zachariasse, Klaas A

    2010-12-09

    The photophysics of N-(4-cyanophenyl)carbazole (NP4CN) was investigated by using absorption and fluorescence spectra, picosecond fluorescence decays, and femtosecond transient absorption. In the nonpolar n-hexane as well as in the polar solvent acetonitrile (MeCN), a locally excited (LE) state is detected, as a precursor for the intramolecular charge transfer (ICT) state. A LE → ICT reaction time τ(2) at 22 °C of 0.95 ps in ethyl cyanide (EtCN) and 0.32 ps in MeCN is determined from the decay of the LE excited state absorption (ESA) maximum around 620 nm. In the ESA spectrum of NP4CN in n-hexane at a pump-probe delay time of 100 ps, an important contribution of the LE band remains alongside the ICT band, in contrast to what is observed in EtCN and MeCN. This shows that a LE ⇄ ICT equilibrium is established in this solvent and the ICT reaction time of 0.5 ps is equal to the reciprocal of the sum of the forward and backward ICT rate constants 1/(k(a) + k(d)). In the photostationary S(0) → S(n) absorption spectrum of NP4CN in n-hexane and MeCN, an additional CT absorption band appears, absent in the sum of the spectra of its electron donor (D) and acceptor (A) subgroups carbazole and benzonitrile. This CT band is located at an energy of ∼4000 cm(-1) lower than for N-phenylcarbazole (NPC), due to the larger electron affinity of the benzonitrile moiety of NP4CN than the phenyl subunit of NPC. The fluorescence spectrum of NP4CN in n-hexane at 25 °C mainly consists of a structured LE emission, with a small ICT admixture, indicating that a LE → ICT reaction just starts to occur under these conditions. In di-n-pentyl ether (DPeE) and di-n-butyl ether (DBE), a LE emission is found upon cooling at the high-energy edge of the ICT fluorescence band, caused by the onset of dielectric solvent relaxation. This is not the case in more polar solvents, such as diethyl ether (DEE) and MeCN, in which a structureless ICT emission band fully overlaps the strongly quenched LE

  20. Design, synthesis and biological evaluation of novel 1,2,3-triazolyl [Formula: see text]-hydroxy alkyl/carbazole hybrid molecules.

    Science.gov (United States)

    Rad, Mohammad Navid Soltani; Behrouz, Somayeh; Behrouz, Marzieh; Sami, Akram; Mardkhoshnood, Mehdi; Zarenezhad, Ali; Zarenezhad, Elham

    2016-08-01

    The design, synthesis and biological study of several novel 1,2,3-triazolyl [Formula: see text]-hydroxy alkyl/carbazole hybrid molecules as a new type of antifungal agent has been described. In this synthesis, the N-alkylation reaction of carbazol-9-ide potassium salt with 3-bromoprop-1-yne afforded 9-(prop-2-ynyl)-9H-carbazole. The 'Click' Huisgen cycloaddition reaction of 9-(prop-2-ynyl)-9H-carbazole with diverse [Formula: see text]-azido alcohols in the presence of copper-doped silica cuprous sulphate led to target molecules in excellent yields. The in vitro antifungal and antibacterial activities of title compounds were screened against various pathogenic fungal strains, Gram-positive and/or Gram-negative bacteria. In particular, 1-(4-((9H-carbazol-9-yl) methyl)-1H-1,2,3-triazol-1-yl)-3-butoxypropan-2-ol (10e) proved to have potent antifungal activity against all fungal tests compared with fluconazole and clotrimazole as studied reference drugs. Our molecular docking analysis revealed an appropriate fitting and a potential powerful interaction between compound 10e and an active site of the Mycobacterium P450DM enzyme. The strong hydrogen bondings between [Formula: see text]-hydroxyl and ether groups in 10e were found to be the main factors that drive the molecule to fit in the active site of enzyme. The in silico pharmacokinetic studies were used for a better description of 10a-10n as potential lead antifungal agents for future investigations.

  1. The Pseudomonas Quinolone Signal (PQS)

    DEFF Research Database (Denmark)

    Sams, Thomas; Baker, Ysobel; Hodgkinson, James;

    2015-01-01

    is now known to be under the con-trol of the quorum sensing (QS) system. Over the last15 years, the Pseudomonas quinolone signal (PQS) has beenfound to play a crucial role in QS by linking the two seg-ments (las and rhl) of the P. aeruginosa N-acylhomoserinelactone-dependent QS signaling pathways. Herein...

  2. Degradation of ochratoxin a by Brevibacterium species.

    Science.gov (United States)

    Rodriguez, Hector; Reveron, Ines; Doria, Francesca; Costantini, Antonella; De Las Rivas, Blanca; Muňoz, Rosario; Garcia-Moruno, Emilia

    2011-10-12

    The ability to degrade ochratoxin A was studied in different bacteria with a well-known capacity to transform aromatic compounds. Strains belonging to Rhodococcus, Pseudomonas, and Brevibacterium genera were grown in liquid synthetic culture medium containing ochratoxin A. Brevibacterium spp. strains showed 100% degradation of ochratoxin A. Ochratoxin α was detected and identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) as a degradation product in the cell-free supernatants. The degradation of ochratoxin A is of public concern for food and environmental safety, because it could contribute to the development of new biological ochratoxin A detoxification systems in foodstuffs. In this study, the degradation of ochratoxin A by bacteria belonging to the food chain was demonstrated for the first time.

  3. Isolation and evaluation of potent Pseudomonas species for bioremediation of phorate in amended soil.

    Science.gov (United States)

    Jariyal, Monu; Gupta, V K; Jindal, Vikas; Mandal, Kousik

    2015-12-01

    Use of phorate as a broad spectrum pesticide in agricultural crops is finding disfavor due to persistence of both the principal compound as well as its toxic residues in soil. Three phorate utilizing bacterial species (Pseudomonas sp. strain Imbl 4.3, Pseudomonas sp. strain Imbl 5.1, Pseudomonas sp. strain Imbl 5.2) were isolated from field soils. Comparative phorate degradation analysis of these species in liquid cultures identified Pseudomonas sp. strain Imbl 5.1 to cause complete metabolization of phorate during seven days as compared to the other two species in 13 days. In soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil), Pseudomonas sp. strain Imbl 5.1 resulted in active metabolization of phorate by between 94.66% and 95.62% establishing the same to be a potent bacterium for significantly relieving soil from phorate residues. Metabolization of phorate to these phorate residues did not follow the first order kinetics. This study proves that Pseudomonas sp. strain Imbl 5.1 has huge potential for active bioremediation of phorate both in liquid cultures and agricultural soils.

  4. Enzyme-mediated quenching of the Pseudomonas quinolone signal (PQS promotes biofilm formation of Pseudomonas aeruginosa by increasing iron availability

    Directory of Open Access Journals (Sweden)

    Beatrix Tettmann

    2016-12-01

    Full Text Available The 2-alkyl-3-hydroxy-4(1H-quinolone 2,4-dioxygenase HodC was previously described to cleave the Pseudomonas quinolone signal, PQS, which is exclusively used in the complex quorum sensing (QS system of Pseudomonas aeruginosa, an opportunistic pathogen employing QS to regulate virulence and biofilm development. Degradation of PQS by exogenous addition of HodC to planktonic cells of P. aeruginosa attenuated production of virulence factors, and reduced virulence in planta. However, proteolytic cleavage reduced the efficacy of HodC. Here, we identified the secreted protease LasB of P. aeruginosa to be responsible for HodC degradation. In static biofilms of the P. aeruginosa PA14 lasB::Tn mutant, the catalytic activity of HodC led to an increase in viable biomass in newly formed but also in established biofilms, and reduced the expression of genes involved in iron metabolism and siderophore production, such as pvdS, pvdL, pvdA and pvdQ. This is likely due to an increase in the levels of bioavailable iron by degradation of PQS, which is able to sequester iron from the surrounding environment. Thus, HodC, despite its ability to quench the production of virulence factors, is contraindicated for combating P. aeruginosa biofilms.

  5. Alkaline cyanide biodegradation by Pseudomonas pseudoalcaligenes CECT5344.

    Science.gov (United States)

    Luque-Almagro, V M; Blasco, R; Huertas, M J; Martínez-Luque, M; Moreno-Vivián, C; Castillo, F; Roldán, M D

    2005-02-01

    Pseudomonas pseudoalcaligenes CECT5344 uses cyanide, cyanate, beta-cyanoalanine, and other cyanoderivatives as nitrogen sources under alkaline conditions, which prevents volatile HCN (pK(a) 9.2) formation. The cyanide consumed by this strain is stoichiometrically converted into ammonium. In addition, this bacterium grows with the heavy metal, cyanide-containing waste water generated by the jewellery industry, and is also a cyanide-resistant strain which induces an alternative oxidase and a siderophore-based mechanism for iron acquisition in the presence of cyanide. The detection of cyanase and beta-cyanoalanine nitrilase activities in cyanide-induced cells suggests their implication in the cyanide degradation pathway.

  6. Biotransformation of nitrobenzene by bacteria containing toluene degradative pathways

    Energy Technology Data Exchange (ETDEWEB)

    Haigler, B.E.; Spain, J.C. (Air Force Civil Engineering Support Agency, Tyndall AFB, FL (United States))

    1991-11-01

    Nonpolar nitroaromatic compounds have been considered resistant to attack by oxygenases because of the electron withdrawing properties of the nitro group. The authors have investigate the ability of seven bacterial strains containing toluene degradative pathways to oxidize nitrobenzene. Cultures were induced with toluene vapor prior to incubation with nitrobenzene, and products were identified by high-performance liquid chromatography and gas chromatography-mass spectrometry. Pseudomonas cepacia G4 and a strain of Pseudomonas harboring the TOL plasmid (pTN2) did not transform nitrobenzene. Cells of Pseudomonas putida F1 and Pseudomonas sp. strain JS150 converted nitrobenzene to 3-nitrocatechol. Transformation of nitrobenzene in the presence of {sup 18}O{sub 2} indicated that the reaction in JS150 involved the incorporation of both atoms of oxygen in the 3-nitrocatechol, which suggests a dioxygenase mechanism. P. putida 39/D, a mutant strain of P. putida F1, converted nitrobenzene to a compound tentatively identified as cis-1, 2-dihydroxy-3-nitrocyclohexa-3, 5-diene. This compound was rapidly converted to 3-nitrocatechol by cells of strain JS150. Cultures of Pseudomonas mendocina KR-1 converted nitrobenzene to a mixture of 3- and 4-nitrophenol (10 and 63%, respectively). Pseudomonas pickettii PKO1 converted nitrobenzene to 3- and 4-nitrocatechol via 3- and 4-nitrophenol. The nitrocatechols were slowly degraded to unidentified metabolites. Nitrobenzene did not serve as an inducer for the enzymes that catalyzed its oxidation.

  7. Protease and urease production during utilization of diesel by fluorescent Pseudomonas species isolated from local soil

    Directory of Open Access Journals (Sweden)

    V.Umamaheswara Rao

    2009-12-01

    Full Text Available Background and objectives: Bacteria, most prevalently the Pseudomonas species possess high capacity to utilize and degrade"npetroleum hydrocarbons and are classified as the hydrocarbonoclastic microorganisms. Many species of the genus"nPseudomonas are notorious for their aerobic degradation capacity, extracellular enzyme production and are metabolically"nversatile organisms capable of utilizing a wide range of hydrocarbons and other compounds. In this study, the ability of diesel"nutilization by some locally isolated Pseudomonas species was tested."nMaterials and Methods: From a local red laterite soil, four different Pseudomonas species were isolated on King’s B medium,"ncharacterized, identified and tested their potential in utilizing diesel, a petroleum hydrocarbon. At the same time, production"nof protease and urease enzymes during the utilization of diesel was also assayed following the standard procedures."nResults: The isolates were grown well on diesel and subsequently produced the extracellular enzymes protease and urease"nat significant levels when compared to their production in the absence of diesel. Optimum temperature and pH for increased"ngrowth by four isolates was found to be 37oC and pH 8.0 indicating the maximum utilization of diesel. All the isolates showed"nmaximum growth in medium with 100% diesel than 100% glycerol as carbon source, when tested with different proportions"nof diesel and glycerol as carbon sources. Plasmid profile of the isolates revealed that, all four Pseudomonas isolates harbored"ntwo low molecular weight plasmids; one with 3 Kb size and the other with 10 kb to 12 Kb size."nConclusion: The four Pseudomonas isolates of the present study were found to have potential in diesel degradation and can"nbe recommended for bioremediation of sites that are contaminated with diesel.

  8. Kinetics of growth and caffeine demethylase production of Pseudomonas sp. in bioreactor.

    Science.gov (United States)

    Gummadi, Sathyanarayana N; Santhosh, Devarai

    2010-09-01

    The effect of various initial caffeine concentrations on growth and caffeine demethylase production by Pseudomonas sp. was studied in bioreactor. At initial concentration of 6.5 g l(-1) caffeine, Pseudomonas sp. showed a maximum specific growth rate of 0.2 h(-1), maximum degradation rate of 1.1 g h(-1), and caffeine demethylase activity of 18,762 U g CDW(-1) (CDW: cell dry weight). Caffeine degradation rate was 25 times higher in bioreactor than in shake flask. For the first time, we show highest degradation of 75 g caffeine (initial concentration 20 g l(-1)) in 120 h, suggesting that the tested strain has potential for successful bioprocess for caffeine degradation. Growth kinetics showed substrate inhibition phenomenon. Various substrate inhibition models were fitted to the kinetic data, amongst which the double-exponential (R(2) = 0.94), Luong (R(2) = 0.92), and Yano and Koga 2 (R(2) = 0.94) models were found to be the best. The Luedeking-Piret model showed that caffeine demethylase production kinetics was growth related. This is the first report on production of high levels of caffeine demethylase in batch bioreactor with faster degradation rate and high tolerance to caffeine, hence clearly suggesting that Pseudomonas sp. used in this study is a potential biocatalyst for industrial decaffeination.

  9. Isolation and characterization of an alginase from mucoid strains of Pseudomonas aeruginosa.

    Science.gov (United States)

    Linker, A; Evans, L R

    1984-09-01

    Strains of Pseudomonas aeruginosa which produce an alginate-like slime polysaccharide were shown to also synthesize an intracellular enzyme which can degrade these polysaccharides and the seaweed alginic acids. The enzyme acts as an eliminase introducing delta 4,5 unsaturation into the uronic acid moiety. It appears to be a polymannuronide lyase which degrades the polysaccharides, depending on their uronic acid composition, to a series of oligosaccharides, the smallest of which is a disaccharide. L-Guluronic acid linkages are not split. The Pseudomonas alginase resembles other bacterial alginases and enzymes from molluscs but differs in some important properties, such as extent of degradation and linkage preference. Nonmucoid forms of the organism produce detectable but much lower amounts of enzyme.

  10. Biodegradation of Decabromodiphenyl Ether (BDE-209 by Crude Enzyme Extract from Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2015-09-01

    Full Text Available The biodegradation effect and mechanism of decabromodiphenyl ether (BDE-209 by crude enzyme extract from Pseudomonas aeruginosa were investigated. The results demonstrated that crude enzyme extract exhibited obviously higher degradation efficiency and shorter biodegradation time than Pseudomonas aeruginosa itself. Under the optimum conditions of pH 9.0, 35 °C and protein content of 2000 mg/L, 92.77% of the initial BDE-209 (20 mg/L was degraded after 5 h. A BDE-209 biodegradation pathway was proposed on the basis of the biodegradation products identified by GC-MS analysis. The biodegradation mechanism showed that crude enzyme extract degraded BDE-209 into lower brominated PBDEs and OH-PBDEs through debromination and hydroxylation of the aromatic rings.

  11. Cyanide production by Pseudomonas fluorescens and Pseudomonas aeruginosa.

    Science.gov (United States)

    Askeland, R A; Morrison, S M

    1983-06-01

    Of 200 water isolates screened, five strains of Pseudomonas fluorescens and one strain of Pseudomonas aeruginosa were cyanogenic. Maximum cyanogenesis by two strains of P. fluorescens in a defined growth medium occurred at 25 to 30 degrees C over a pH range of 6.6 to 8.9. Cyanide production per cell was optimum at 300 mM phosphate. A linear relationship was observed between cyanogenesis and the log of iron concentration over a range of 3 to 300 microM. The maximum rate of cyanide production occurred during the transition from exponential to stationary growth phase. Radioactive tracer experiments with [1-14C]glycine and [2-14C]glycine demonstrated that the cyanide carbon originates from the number 2 carbon of glycine for both P. fluorescens and P. aeruginosa. Cyanide production was not observed in raw industrial wastewater or in sterile wastewater inoculated with pure cultures of cyanogenic Pseudomonas strains. Cyanide was produced when wastewater was amended by the addition of components of the defined growth medium.

  12. Synthesis and properties of a star-shaped organic material with triphenylamine and N-vinyl carbazole units

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A starburst triphenylamine cored N-vinyl carbazole (V-Cz) branched compound was designed and synthesized via optimized Heck reaction in a yield of 40-60%. Moderate yield came from decomposition of V-Cz and self-coupling of triiodo-triphenylamine.TCz-TPA adopts a highly twisted propeller conformation by molecular mechanical optimization. It is readily soluble for its highly twisted conformation. Transparent and pinhole free films could be easily fabricated by spin-coating for its starburst structure. It emits blue-greenish light in CH2Cl2 peaked at 460 nm with a narrow full-width at half-maximum (FWHM) of 65 nm. As compared,the absorption peaks of the spin-coated film blue shifted and emission peak red shifted to 510 nm with a FWHM of 96 nm.

  13. Photoconductivity of novel poly(N-vinyl)-3-[p-nitrophenylazo]carbazole/CdS-nanoparticle polymer composite

    Institute of Scientific and Technical Information of China (English)

    DING Li-yun; JIANG De-sheng; HUANG Jun; DAI Lei; LIU Cheng; WANG Jun-tao; LI Bin

    2006-01-01

    The photoconductive characteristic of the inorganic/organic hybridized polymer system is reported,in which a novel bi-functional photorefractive (PR) poly(N-vinyl)-3-[p-nitrophenylazo]carbazole (PVNPAK) serves as a polymeric charge-transporting and second-order nonliner optical matrix and quantum dots composed of surface passivated cadmium sulfide serve as a charge-generation sensitizer. The hybrid PVNPAK/CdS-nanoparticles polymer composites with different mass ratio of CdS to PVNPAK were prepared. The generation of photocurrent on illumination and photoconductive properties of the PVNPAK/CdS-nanoparticles polymer composites were studied. The results show that the addition of CdS nanoparticle as a photosensitizer can enhance the photoconductivity of the PVNPAK significantly because of the properties of the high quantum efficiency of photosensitization and high charge transport to conducting polymer.

  14. Microfluidic biosensor array with integrated poly(2,7-carbazole)/fullerene-based photodiodes for rapid multiplexed detection of pathogens.

    Science.gov (United States)

    Matos Pires, Nuno Miguel; Dong, Tao

    2013-11-25

    A multiplexed microfluidic biosensor made of poly(methylmethacrylate) (PMMA) was integrated into an array of organic blend heterojunction photodiodes (OPDs) for chemiluminescent detection of pathogens. Waterborne Escherichia coli O157:H7, Campylobacter jejuni and adenovirus were targeted in the PMMA chip, and detection of captured pathogens was conducted by poly(2,7-carbazole)/fullerene OPDs which showed a responsivity over 0.20 A/W at 425 nm. The limits of chemiluminescent detection were 5 × 10(5) cells/mL for E. coli, 1 × 10(5) cells/mL for C. jejuni, and 1 × 10(-8) mg/mL for adenovirus. Parallel analysis for all three analytes in less than 35 min was demonstrated. Further recovery tests illustrated the potential of the integrated biosensor for detecting bacteria in real water samples.

  15. Kinetic Modeling of Dye Effluent Biodegradation by Pseudomonas Stutzeri

    Directory of Open Access Journals (Sweden)

    N. Rajamohan

    2013-04-01

    Full Text Available Dye industry waste water is difficult to treat because of the presence of dyes with complex aromatic structure. In this research study, the biodegradation studies of dye effluent were performed utilizing Pseudomonas stutzeri in a controlled laboratory environment under anoxic conditions. The effects of operational parameters like initial pH of the effluent and initial Chemical Oxygen Demand (COD of the effluent on percentage COD removal were studied. A biokinetic model is established giving the dependence of percentage COD removal on biomass concentration and initial COD of the effluent. The biokinetics of the COD removal was found to be first order with respect to both the microbial concentration and initial COD of the effluent. The optimal pH for better bacterial degradation was found to be 8.The specific degradation rate was found to be 0.1417 l/g Dry Cell Mass (DCM h, at 320 C.

  16. Novel glass-forming organic materials. 2. Structure and fluorescence of pyrene- and carbazole-containing cyclohexane, bicyclooctene, and adamantane

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, J.C.; Conger, B.M.; Chen, S.H. [Univ. of Rochester, NY (United States)] [and others

    1997-01-01

    A series of novel glass-forming organic materials consisting of pyrenyl and carbazolyl groups attached to cyclohexane with a 1-axial-2-equatorial configuration, bicyclo[2.2.2]oct-7-ene with an all-exo configuration, and adamantane were synthesized and characterized. On the basis of proton NMR spectra, it was found that the rotation of pendant pyrenyl and carbazolyl groups is restricted in the bicyclic system presumably because of steric hindrance in the all-exo configuration. In contrast, free rotation was found to prevail in cyclohexane- and adamantane-based systems. Fluorescence spectra gathered in solution at room temperature show evidence exclusively for intramolecular excimer formation in pyrene-containing compounds up to a concentration of 10{sup -4} M. On the contrary, carbazole-containing compounds are not prone to excimer formation in the concentration range 10{sup -6}-10{sup -3} M, presumably because of the more stringent requirements of interchromophoric distance and orientation. Although both pyrene and carbazole are highly crystalline on their own, attachment to cyclic, bicyclic, and tricyclic central cores was found to contribute to an ease of vitrification of the hybrid systems with a T{sub g} ranging from 43 to 132 {degrees}C. Moreover, the quenched glasses of all seven model systems were found to possess morphological stability in view of the absence of recrystallization upon heating from 0 to 200 {degrees}C at a heating rate ranging from 0.2 to 20{degrees}C/min. Morphological stability was further supported by the absence of recrystallization upon prolonged thermal annealing at temperatures above T{sub g}. 24 refs., 6 figs.

  17. Four new carbazole alkaloids from Murraya koenigii that display anti-inflammatory and anti-microbial activities.

    Science.gov (United States)

    Nalli, Yedukondalu; Khajuria, Vidushi; Gupta, Shilpa; Arora, Palak; Riyaz-Ul-Hassan, Syed; Ahmed, Zabeer; Ali, Asif

    2016-03-28

    In our present study, four new, designated as murrayakonine A-D (), along with 18 known carbazole alkaloids were isolated from CHCl3 : MeOH (1 : 1) crude extracts of the stems and leaves of Murraya koenigii (Linn.) Spreng. The structures of the all isolated compounds were characterized by analysis of HR-ESI-MS and NMR (1D and 2D spectroscopy) results, and comparison of their data with the literature data. For the first time, all the isolates were evaluated for their anti-inflammatory activities, using both in vitro and in vivo experiments, against the key inflammatory mediators TNF-α and IL-6. The new compound murrayakonine A (), O-methylmurrayamine A () and mukolidine () were proven to be the most active, efficiently inhibiting TNF-α and IL-6 release in a dose-dependent manner and showing decreased LPS induced TNF-α and IL-6 production in human PBMCs. Furthermore, all the isolates were screened for their antimicrobial potential, and the compounds girinimbine () (IC50 3.4 μM) and 1-hydroxy-7-methoxy-8-(3-methylbut-2-en-1-yl)-9H-carbazole-3-carbaldehyde () (IC50 10.9 μM) displayed potent inhibitory effects against Bacillus cereus. Furthermore, compounds murrayamine J () (IC50 11.7 μM) and koenimbine () (IC50 17.0 μM) were active against Staphylococcus aureus. However, none of the compounds were found to be active against Escherichia coli or Candida albicans.

  18. From Sediment to Top Predators: Broad Exposure of Polyhalogenated Carbazoles in San Francisco Bay (U.S.A.).

    Science.gov (United States)

    Wu, Yan; Tan, Hongli; Sutton, Rebecca; Chen, Da

    2017-02-21

    The present study provides the first comprehensive investigation of polyhalogenated carbazoles (PHCZs) contamination in an aquatic ecosystem. PHCZs have been found in soil and aquatic sediment from several different regions, but knowledge of their bioaccumulation and trophodynamics is extremely scarce. This work investigated a suite of 11 PHCZ congeners in San Francisco Bay (United States) sediment and organisms, including bivalves (n = 6 composites), sport fish (n = 12 composites), harbor seal blubber (n = 18), and bird eggs (n = 8 composites). The most detectable congeners included 3,6-dichlorocarbazole (36-CCZ), 3,6-dibromocarbazole (36-BCZ), 1,3,6-tribromocarbazole (136-BCZ), 1,3,6,8-tetrabromocarbazole (1368-BCZ), and 1,8-dibromo-3,6-dichlorocarbazole (18-B-36-CCZ). The median concentrations of ΣPHCZs were 9.3 ng/g dry weight in sediment and ranged from 33.7 to 164 ng/g lipid weight in various species. Biomagnification was observed from fish to harbor seal and was mainly driven by chlorinated carbazoles, particularly 36-CCZ. Congener compositions of PHCZs differed among species, suggesting that individual congeners may be subject to different bioaccumulation or metabolism in species occupying various trophic levels in the studied aquatic system. Toxic equivalent (TEQ) values of PHCZs were determined on the basis of their relative effect potencies (REP) compared to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The median TEQ was 1.2 pg TEQ/g dry weight in sediment and 4.8-19.5 pg TEQ/g lipid weight in biological tissues. Our study demonstrated the broad exposure of PHCZs in San Francisco Bay and their characteristics of bioaccumulation and biomagnification along with dioxin-like effects. These findings raise the need for additional research to better elucidate their sources, environmental behavior, and fate in global environments.

  19. Theoretical investigation of the broad one-photon absorption line-shape of a flexible symmetric carbazole derivative.

    Science.gov (United States)

    Liu, Yanli; Cerezo, Javier; Santoro, Fabrizio; Rizzo, Antonio; Lin, Na; Zhao, Xian

    2016-08-17

    The one-photon absorption spectrum of a carbazole derivative has been studied by employing density functional response theory combined with a mixed quantum/classical (QC) approach to simulate the spectral shape. In a first step of our analysis we employed the vertical gradient (VG) vibronic model to investigate the role of Franck-Condon (FC) profiles of the first ten electronic excited states of the system, underlying most of the range of the experimental spectrum. We then focussed on the first six excited states covering the low-energy region of the spectrum, and investigated the effect of inter-state electronic couplings on the spectral shapes within Herzberg-Teller (HT) theory. Furthermore, in order to introduce the broadening effects due to the two inter-ring torsions, we employed a QC approach, adopting VG vibronic models for high-frequency modes and computing the contribution of the torsions to the spectrum from the distribution of the excitation energies along a two-dimensional relaxed potential energy. Finally, we estimated the solvent inhomogeneous broadening by computing the solvent reorganization energy using a polarizable continuum model. Our calculations allow us to obtain a non-phenomenological description of the low-energy part of the spectrum in semi-quantitative agreement with experiment and to dissect the relative importance of solvent, torsional flexibility, FC vibronic progressions, and inter-state couplings in determining its broad spectral shapes and the modulation of its intensity. Our analysis also clearly highlights that the investigated carbazole represents a big challenge for available methodologies due to the existence of many close-lying excited electronic states coupled by internal low-frequency and high-frequency motions and by solvent fluctuations. The study of their impact on the spectra at the HT level is only approximate and more refined treatments would require a fully quantum-dynamical calculation on the manifold of the coupled

  20. PbBr-Based Layered Perovskite Organic-Inorganic Superlattice Having Carbazole Chromophore; Hole-Mobility and Quantum Mechanical Calculation.

    Science.gov (United States)

    Era, Masanao; Yasuda, Takeshi; Mori, Kento; Tomotsu, Norio; Kawano, Naoki; Koshimizu, Masanori; Asai, Keisuke

    2016-04-01

    We have successfully evaluated hole mobility in a spin-coated film of a lead-bromide based layered perovskite having carbazole chromophore-linked ammonium molecules as organic layer by using FET measurement. The values of hole mobility, threshold voltage and on/off ratio at room temperature were evaluated.to.be 1.7 x 10(-6) cm2 V-1 s-1, 27 V and 28 V, respectively. However, the spin-coated films on Si substrates were not so uniform compared with those on fused quartz substrates. To improve the film uniformity, we examined the relationship between substrate temperature during spin-coating and film morphology in the layered perovskite spin-coated films. The mean roughness of the spin-coated films on Si substrates was dependent on the substrate temperature. At 353 K, the mean roughness was minimized and the carrier mobility was enhanced by one order of magnitude; the values of hole mobility and threshold voltage were .estimated to be 3.4 x 10(-5) cm2 V-1 s-1, and 22 V at room temperature in a preliminary FET evaluation, respectively. In addition, we determined a crystal structure of the layered perovskite by X-ray diffraction analysis. To gain a better understanding of the observed hole transports, we conducted quantum mechanical calculations using the obtained crystal structure information. The calculated band structure of the layered organic perovskite showed that the valence band is composed of the organic carbazole layer, which confirms that.the measured hole mobility is mainly derived from the organic part of the layered perovskite. Band and hopping transport mechanisms were discussed by calculating the effective masses and transfer integrals for the 2D periodic system of the organic layer in isolation.

  1. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  2. Biotransformation of geosmin by terpene-degrading bacteria.

    Science.gov (United States)

    Two terpene-degrading bacteria that are able to transform geosmin have been identified. Pseudomonas sp. SBR3-tpnb, isolated on -terpinene, converts geosmin to several products; the major products are keto-geosmins. This geosmin transformation ability is inducible by -terpinene. Rhodococcus wratisl...

  3. One-pot synthesis of carbazole based 3-hydroxy-4H-chromen-4-ones by modified Algar-Flynn-Oyamada reaction and their antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Ashok Dongamanti

    2015-01-01

    Full Text Available A new series of 2-(9-ethyl-9H-carbazol-3-yl-3-hydroxy-4Hchromen-4-ones have been synthesized from substituted 2-hydroxy acetophenones and 9-ethyl-9H-carbazole-3-carbaldehyde using NaOH and H2O2 by modified Algar-Flynn-Oyamada reaction. In this method flavonols are synthesized without isolating chalcones in good yields (70-82%. The structures of the compounds were established on the basis of 1H-NMR, 13CNMR, FT-IR and mass spectral and analytical data. All the compounds were evaluated for their antimicrobial activity against bacteria such as Staphylococus aureus, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae as well as fungi such as Aspergillus flavus and Fusarium oxysporum.

  4. Molecular modeling and experimental studies on structure and NMR parameters of 9-benzyl-3,6-diiodo-9H-carbazole

    DEFF Research Database (Denmark)

    Radula-Janik, Klaudia; Kupka, Teobald; Ejsmont, Krzysztof;

    2015-01-01

    A combined experimental and theoretical study has been performed on 9-benzyl-3,6-diiodo-9H-carbazole. Experimental X-ray (100.0 K) and room-temperature 13C NMR studies were supported by advanced density functional theory (DFT) calculations. The non relativistic structure optimization was performed.......57 ppm dropped to 5.6 ppm). A good linear correlation between experimental and theoretically predicted structural and NMR parameters was observed....

  5. Anion Binding Studies on Receptors Derived from the Indolo[2,3-a]carbazole Scaffold Having Different Binding Cavity Sizes

    Directory of Open Access Journals (Sweden)

    Guzmán Sánchez

    2014-07-01

    Full Text Available The indolo[2,3-a]carbazole scaffold is a fused polyheteroaromatic system bearing two NH groups which suitably converge as hydrogen bond donor sites for the recognition of anions. A simple derivatisation of the indolocarbazole system at positions 1 and 10 with different functional groups, namely alcohols and amides, has contributed to modulate the anion binding selectivity and sensibility. A particularly good response has been obtained for the benzoate anion.

  6. A novel carbazole-based fluorescent probe:3,6-Bis-[(N-ethylcarbazole-3-y1)-propene-1-keto]-N-ethylcarbazole

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel carbazole-based compound 5,3,6-bis[(N-ethylcarbazole-3-yl)-propene-1-keto]-N-ethylcarbazole has been designed, synthesized and characterized.The absorption and fluorescence spectra in solvents of different polarities prove that the compound has a distinct intramolecular charge transfer character.Compound 5 can be used as a new class of fluorescent probe or biosensor due to its sensitivity to the local microenvironment such as solvent polarity.

  7. Complete Genome Sequence of Pseudomonas sp. UK4, a Model Organism for Studies of Functional Amyloids in Pseudomonas

    DEFF Research Database (Denmark)

    Dueholm, Morten Simonsen; Danielsen, Heidi Nolsøe; Nielsen, Per Halkjær

    2014-01-01

    Here, we present the complete genome of Pseudomonas sp. UK4. This bacterium was the first Pseudomonas strain shown to produce functional amyloids, and it represents a model organism for studies of functional amyloids in Pseudomonas (Fap).......Here, we present the complete genome of Pseudomonas sp. UK4. This bacterium was the first Pseudomonas strain shown to produce functional amyloids, and it represents a model organism for studies of functional amyloids in Pseudomonas (Fap)....

  8. Experimental and theoretical studies on new 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-alkyl-10H-phenothiazine-3-carbaldehydes

    Science.gov (United States)

    Stalindurai, Kesavan; Gokula Krishnan, Kannan; Nagarajan, Erumaipatty Rajagounder; Ramalingan, Chennan

    2017-02-01

    Synthesis of fused heterocyclic aldehydes with carbazole (CZ) structural motif linked at C-7 position on phenothiazines (PTZ), 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-butyl-10H-phenothiazine-3-carbaldehyde (1) and 7-(3,6-di-tert-butyl-9H-carbazol-9-yl)-10-hexyl-10H-phenothiazine-3-carbaldehyde (2) has been accomplished and are characterized through experimental and computational techniques. The optimized structure with their bonding aspects and vibrational frequencies of the same have been examined utilizing DFT-B3LYP technique with a basis set 6-311++G(d,p). In the optimized structures of 1 and 2, the bond lengths and bond angles are in accord with their corresponding reported analogous. The vibrational frequencies resulted from experimental as well as theoretical are in well accord with each other. Further, the results of polarizabilities, first order hyperpolarizabilities and dipole moment of 1 and 2 imply that these could be utilized for the preparation of NLO crystals which might generate second order harmonic waves.

  9. BC3EE2,9B, a synthetic carbazole derivative, upregulates autophagy and synergistically sensitizes human GBM8901 glioblastoma cells to temozolomide.

    Science.gov (United States)

    Chen, Chien-Min; Syu, Jhih-Pu; Way, Tzong-Der; Huang, Li-Jiau; Kuo, Sheng-Chu; Lin, Chung-Tien; Lin, Chih-Li

    2015-11-01

    Glioblastoma multiforme (GBM) is the most fatal form of human brain cancer. Although temozolomide (TMZ), an oral alkylating chemotherapeutic agent, improves the survival rate, the prognosis of patients with GBM remains poor. Naturally occurring carbazole alkaloids isolated from curry leaves (Murraya koenigii Spreng.) have been shown to possess a wide range of anticancer properties. However, the effects of carbazole derivatives on glioblastoma cells remain poorly understood. In the present study, anti‑glioblastoma profiles of a series of synthetic carbazole derivatives were evaluated in vitro. The most promising derivative in this series was BC3EE2,9B, which showed significant anti‑proliferative effects in GBM8401 and GBM8901 cells. BC3EE2,9B also triggered cell‑cycle arrest, most prominently at the G1 stage, and suppressed glioblastoma cell invasion and migration. Furthermore, BC3EE2,9B induced autophagy‑mediated cell death and synergistically sensitized GBM cells to TMZ cytotoxicity. The possible mechanism underlying BC3EE2,9B‑induced autophagy may involve activation of adenosine monophosphate-activated protein kinase and the attenuation of the Akt and mammalian target of the rapamycin downstream signaling pathway. Taken together, the present results provide molecular evidence for the mode of action governing the ability of BC3EE2,9B to sensitize drug‑resistant glioblastoma cells to the chemotherapeutic agent TMZ.

  10. Synthesis, biological evaluation and molecular modeling study of novel tacrine-carbazole hybrids as potential multifunctional agents for the treatment of Alzheimer's disease.

    Science.gov (United States)

    Thiratmatrakul, Supatra; Yenjai, Chavi; Waiwut, Pornthip; Vajragupta, Opa; Reubroycharoen, Prasert; Tohda, Michihisa; Boonyarat, Chantana

    2014-03-21

    New tacrine-carbazole hybrids were developed as potential multifunctional anti-Alzheimer agents for their cholinesterase inhibitory and radical scavenging activities. The developed compounds showed high inhibitory activity on acetylcholinesterase (AChE) with IC50 values ranging from 0.48 to 1.03 μM and exhibited good inhibition selectivity against AChE over butyrylcholinesterase (BuChE). Molecular modeling studies revealed that these tacrine-carbazole hybrids interacted simultaneously with the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. The derivatives containing methoxy group showed potent ABTS radical scavenging activity. Considering their neuroprotection, our results indicate that these derivatives can reduce neuronal death induced by oxidative stress and β-amyloid (Aβ). Moreover, S1, the highest potency for both radical scavenging and AChE inhibitory activity, exhibited an ability to improve both short-term and long-term memory deficit in mice induced by scopolamine. Overall, tacrine-carbazole derivatives can be considered as a candidate with potential impact for further pharmacological development in Alzheimer's therapy.

  11. Study of the pore filling fraction of carbazole-based hole-transporting materials in solid-state dye-sensitized solar cells

    Directory of Open Access Journals (Sweden)

    Marwa Ben Manaa

    2016-07-01

    Full Text Available Carbazole-based molecular glasses have emerged as a promising alternative to the widely used hole-transporting materials (HTM spiro-OMeTAD in solid-state dye-sensitized solar cells (DSSCs. The pore filling fraction (PFF of the mesoporous TiO2 layer by the HTM appears as a key parameter determining the final efficiency of a DSSC. In this work, the pore-filling properties of a family of carbazole-based HTMs are investigated for the first time and the photovoltaic behavior of DSSC devices (fabricated using the D102 dye is discussed in light of the present findings. It is found that N-aryl substituted 3,6-bis(diphenylaminyl-carbazole derivatives exhibit relatively low PFF of ca. 60%. Methoxy groups on the diphenylamine moieties have little influence on the PFF, indicating that the strong enhancement in power conversion efficiency (PCE is not related to an improved filling of the pores by the HTM. N-alkylated HTMs lead to higher PFF, increasing with the alkyl chain length, up to 78%.

  12. Theoretical Study on the Optical Properties for 2,7- and 3,6-Linked Carbazole Trimers by Time-dependent Density Functional Theory

    Institute of Scientific and Technical Information of China (English)

    WANG Han-Lu; WANG Xue-Ye; WANG Ling; WANG Heng-Liang; LIU Ai-Hong

    2007-01-01

    Electronic properties, such as HOMO and LUMO energies, band gaps, ionization potential (IP) and electron affinity (EA) of 2,7- and 3,6-linked carbazole trimers, two conjugated oligomers with different linkages of carbazole, were studied by the density functional theory with Becke-Lee-Young-Parr composite exchange correlation functional (B3LYP). The absorption spectra of these compounds were also investigated by time-dependent density functional theory (TD-DFT) with 6-31G* basis set. The calculated results indicated that the HOMO and LUMO of the 2,7- and 3,6-linked carbazole trimers are both slightly destabilized on going from methyl substitution to sec-butyl substitution. Both IP and EA exhibit their good hole-transporting but poor electron-accepting ability. The presence of alkyl groups on the nitrogen atoms does not affect the intra-chain electronic delocalization along the molecular frame. Thus no significant effect on the band gap and absorption spectra of compounds has been found.

  13. Kinetics Modelling of the Biodegradation of Benzene, Toluene and Phenol as Single Substrate and Mixed Substrate by Using Pseudomonas putida

    OpenAIRE

    Mathur, A K; Majumder, C. B.

    2010-01-01

    In the present work, kinetics of the biodegradation of benzene, toluene and phenol by using a pure culture of Pseudomonas putida (MTCC 1194) was determined by measuring the specific growth rate and degradation rate with substrate concentration as a function of time in a batch reactor. In general, the degradation rate of benzene, toluene and phenol increased with the increase in the initial substrate concentration and then decreased after reaching a maximum, showing substrate inhibition kineti...

  14. Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Daniel E. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Gulliver, Djuna [AECOM Technology Corporation, Pittsburgh, PA (United States)

    2016-10-06

    The draft genome sequence ofPseudomonas stutzeristrain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

  15. Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

    Science.gov (United States)

    2016-01-01

    The draft genome sequence of Pseudomonas stutzeri strain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

  16. Novel Dehalogenase Mechanism for 2,3-Dichloro-1-Propanol Utilization in Pseudomonas putida Strain MC4

    NARCIS (Netherlands)

    Arif, Muhammad Ilan; Samin, Ghufrana; van Leeuwen, Jan G. E.; Oppentocht, Jantien; Janssen, Dick B.

    2012-01-01

    A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catal

  17. Genomics of Secondary Metabolism in Pseudomonas spp.

    Science.gov (United States)

    Pseudomonas is a heterogeneous genus of bacteria known for its ubiquity in natural habitats and its prolific production of secondary metabolites. The structurally diverse chemical structures produced by Pseudomonas spp. result from biosynthetic processes with unusual features that have revealed no...

  18. Pseudomonas-follikulitis efter badning i spabad

    DEFF Research Database (Denmark)

    Uldall Pallesen, Kristine Appel; Andersen, Klaus Ejner; Mørtz, Charlotte Gotthard

    2012-01-01

    Pseudomonas aeruginosa is a rare cause of folliculitis. Pseudomonas folliculitis can develop after contact with contaminated water from swimming pools, hot tubs and spa baths. Systemic therapy may be indicated in patients with widespread lesions, systemic symptoms or in immunosuppressed patients...

  19. Aerobic biodegradation pathway for Remazol Orange by Pseudomonas aeruginosa.

    Science.gov (United States)

    Sarayu, K; Sandhya, S

    2010-02-01

    Removal of azo dyes from effluent generated by textile industries is rather difficult. Azo dyes represent a major class of synthetic colorants that are mutagenic and carcinogenic. Pseudomonas aeruginosa grew well in the presence of Remazol Orange (RO) and was able to decolorize and degrade it. In the present study, the decolorization and degradation efficiency using single culture P. aeruginosa with RO and textile wastewaters is studied. The elucidation of decolorization pathway for P. aeruginosa is of special interest. The degradation pathway and the metabolic products formed during the degradation were also predicted with the help of high performance liquid chromatography, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy analysis. The data show the cleavage of the azo dye RO to form both methyl metanilic acid and 4-aminobenzoic acid after decolorization and finally to oxidation forms benzoic acid, alkenes, aldehydes, and alkynes. The organism was able to decolorize the dye RO and wastewater effectively to the maximum of 82.4% and 62%, respectively.

  20. Pseudomonas putida CSV86: a candidate genome for genetic bioaugmentation.

    Directory of Open Access Journals (Sweden)

    Vasundhara Paliwal

    Full Text Available Pseudomonas putida CSV86, a plasmid-free strain possessing capability to transfer the naphthalene degradation property, has been explored for its metabolic diversity through genome sequencing. The analysis of draft genome sequence of CSV86 (6.4 Mb revealed the presence of genes involved in the degradation of naphthalene, salicylate, benzoate, benzylalcohol, p-hydroxybenzoate, phenylacetate and p-hydroxyphenylacetate on the chromosome thus ensuring the stability of the catabolic potential. Moreover, genes involved in the metabolism of phenylpropanoid and homogentisate, as well as heavy metal resistance, were additionally identified. Ability to grow on vanillin, veratraldehyde and ferulic acid, detection of inducible homogentisate dioxygenase and growth on aromatic compounds in the presence of heavy metals like copper, cadmium, cobalt and arsenic confirm in silico observations reflecting the metabolic versatility. In silico analysis revealed the arrangement of genes in the order: tRNA(Gly, integrase followed by nah operon, supporting earlier hypothesis of existence of a genomic island (GI for naphthalene degradation. Deciphering the genomic architecture of CSV86 for aromatic degradation pathways and identification of elements responsible for horizontal gene transfer (HGT suggests that genetic bioaugmentation strategies could be planned using CSV86 for effective bioremediation.

  1. Biodegradation of anionic surfactant, sodium dodecyl sulphate by Pseudomonas aeruginosa MTCC 10311.

    Science.gov (United States)

    Ambily, P S; Jisha, M S

    2012-07-01

    The anionic surfactant sodium dodecyl sulphate (SDS), the core components of detergent and cosmetic product formulations, contributes significantly to the pollution profile of sewage and wastewater of all kinds. In this study, 44 SDS degrading strains were isolated by soil enrichment methods and the utilization efficiency was assessed by methylene blue active substances (MBAS) assay and High performance liquid chromatography (HPLC) method. Isolate S2 which showed maximum degradation was identified as Pseudomonas aeruginosa MTCC 10311 based on phenotypic features and 16 S rDNA typing. The isolate was found to harbor plasmid within the size range of 9-10 kb. The cured derivative of SDS degrading Pseudomonas aeruginosa was obtained at a frequency of 10.7% by incubation with ethidium bromide (500 mg ml(-1) at 40 degrees C. 96% of SDS degradation occurred at 1500 ppm level within 48 hr of incubation, whereas higher concentration of SDS (10000 ppm) showed only 20% degradation. The optimum temperature and pH was 30 degrees C and 7.5, respectively. The additional supplementation of carbon and nitrogen source increased the degradation capacity from 93 to 95% and 90 to 96% respectively within 36 hrs of incubation.

  2. Plasmid-mediated biodegradation of the anionic surfactant sodium dodecyl sulphate, by Pseudomonas aeruginosa S7.

    Science.gov (United States)

    Yeldho, Deepthi; Rebello, Sharrel; Jisha, M S

    2011-01-01

    Sodium dodecyl sulphate (SDS), an anionic surfactant, has been used extensively due to its low cost and excellent foaming properties. Fifteen different bacterial isolates capable of degrading SDS were isolated from detergent contaminated soil by enrichment culture technique and the degradation efficiency was assessed by Methylene Blue Active Substances (MBAS) assay. The most efficient SDS degrading isolate was selected and identified as Pseudomonas aeruginosa S7. The selected isolate was found to harbor a single 6-kb plasmid. Acridine orange, ethidium bromide, SDS and elevated temperatures of incubation failed to cure the plasmid. The cured derivatives of SDS degrading Pseudomonas aeruginosa were obtained only when ethidium bromide and elevated temperature (40 °C) were used together. Transformation of E. coli DH5α with plasmid isolated from S7 resulted in subsequent growth of the transformants on minimal salt media with SDS (0.1%) as the sole source of carbon. The SDS degradation ability of S7 and the transformant was found to be similar as assessed by Methylene Blue Active Substance Assay. The antibiotic resistance profiles of S7, competent DH5α and transformant were analyzed and it was noted that the transfer of antibiotic resistance correlated with the transfer of plasmid as well as SDS degrading property.

  3. Plasmid-mediated Detoxification of Mycotoxin Zearalenone in Pseudomonas Sp. ZEA-1

    OpenAIRE

    2007-01-01

    The Pseudomonas sp. Strain ZEA-1 was isolated from rhizosphere of corn plant by an enrichment technique showed capability of utilizing zearalenone as the sole source of carbon. The bacterium rapidly utilized zearalenone beyond 200 µg/ml and showed prolific growth in a minimal medium containing 100 µg/ml zearalenone source. The course of ZEA degradation as well as the formation of its metabolites was observed by UV Spectrophotometer and thin layer chromatography analysis. Toxicity of biotransf...

  4. Biological effects of 6-formylindolo[3,2-b]carbazole (FICZ) in vivo are enhanced by loss of CYP1A function in an Ahr2-dependent manner.

    Science.gov (United States)

    Wincent, Emma; Kubota, Akira; Timme-Laragy, Alicia; Jönsson, Maria E; Hahn, Mark E; Stegeman, John J

    2016-06-15

    6-Formylindolo[3,2-b]carbazole (FICZ) is a potent aryl hydrocarbon receptor (AHR) agonist that is efficiently metabolized by AHR-regulated cytochrome P4501 enzymes. FICZ is a proposed physiological AHR ligand that induces its own degradation as part of a regulatory negative feedback loop. In vitro studies in cells show that CYP1 inhibition in the presence of FICZ results in enhanced AHR activation, suggesting that FICZ accumulates in the cell when its metabolism is blocked. We used zebrafish (Danio rerio) embryos to investigate the in vivo effects of FICZ when CYP1A is knocked down or inhibited. Embryos were injected with morpholino antisense oligonucleotides targeting CYP1A (CYP1A-MO), Ahr2, or a combination of both. FICZ exposure of non-injected embryos or embryos injected with control morpholino had little effect. In CYP1A-MO-injected embryos, however, FICZ dramatically increased mortality, incidence and severity of pericardial edema and circulation failure, reduced hatching frequency, blocked swim bladder inflation, and strongly potentiated expression of Ahr2-regulated genes. These effects were substantially reduced in embryos with a combined knockdown of Ahr2 and CYP1A, indicating that the toxicity was mediated at least partly by Ahr2. Co-exposure to the CYP1 inhibitor alpha-naphthoflavone (αNF) and FICZ had similar effects as the combination of CYP1A-MO and FICZ. HPLC analysis of FICZ-exposed embryos showed increased levels of FICZ after concomitant CYP1A-MO injection or αNF co-exposure. Together, these results show that a functioning CYP1/AHR feedback loop is crucial for regulation of AHR signaling by a potential physiological ligand in vivo and further highlights the role of CYP1 enzymes in regulating biological effects of FICZ.

  5. Molecular cloning of novel genes for polycyclic aromatic hydrocarbon degradation from Comamonas testosteroni GZ39.

    OpenAIRE

    1996-01-01

    Three strains of Comamonas testosteroni were isolated from river sediment for the ability to degrade phenanthrene; two of the strains also grew on naphthalene, and one strain also grew on anthracene. The homology of the genes for polycyclic aromatic hydrocarbon degradation in these strains to the classical genes (nah) for naphthalene degradation from Pseudomonas putida NCIB 9816-4 was determined. The three C. testosteroni strains showed no homology to the nah gene probe even under low-stringe...

  6. Biodegradation of benzidine based dye Direct Blue-6 by Pseudomonas desmolyticum NCIM 2112.

    Science.gov (United States)

    Kalme, S D; Parshetti, G K; Jadhav, S U; Govindwar, S P

    2007-05-01

    Pseudomonas desmolyticum NCIM 2112 was able to degrade a diazo dye Direct Blue-6 (100 mg l(-1)) completely within 72 h of incubation with 88.95% reduction in COD in static anoxic condition. Induction in the activity of oxidative enzymes (LiP, laccase) and tyrosinase while decolorization in the batch culture represents their role in degradation. Dye also induced the activity of aminopyrine N-demethylase, one of the enzyme of mixed function oxidase system. The biodegradation was monitored by UV-Vis, IR spectroscopy and HPLC. The final products, 4-amino naphthalene and amino naphthalene sulfonic acid were characterized by GC-mass spectroscopy.

  7. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.

    2007-01-01

    Silver has been recognized for its antimicrobial properties for centuries. Most studies on the antibacterial efficacy of silver, with particular emphasis on wound healing, have been performed on planktonic bacteria. Our recent studies, however, strongly suggest that colonization of wounds involves...... bacteria in both the planktonic and biofilm modes of growth. The action of silver on mature in vitro biofilms of Pseudomonas aeruginosa, a primary pathogen of chronic infected wounds, was investigated. The results show that silver is very effective against mature biofilms of P. aeruginosa......, but that the silver concentration is important. A concentration of 5-10 ig/mL silver sulfadiazine eradicated the biofilm whereas a lower concentration (1 ig/mL) had no effect. The bactericidal concentration of silver required to eradicate the bacterial biofilm was 10-100 times higher than that used to eradicate...

  8. Growth of genetically engineered Pseudomonas aeruginosa and Pseudomonas putida in soil and rhizosphere.

    OpenAIRE

    Yeung, K H; Schell, M A; Hartel, P G

    1989-01-01

    The effect of the addition of a recombinant plasmid containing the pglA gene encoding an alpha-1,4-endopolygalacturonase from Pseudomonas solanacearum on the growth of Pseudomonas aeruginosa and Pseudomonas putida in soil and rhizosphere was determined. Despite a high level of polygalacturonase production by genetically engineered P. putida and P. aeruginosa, the results suggest that polygalacturonase production had little effect on the growth of these strains in soil or rhizosphere.

  9. Optical biosensor with poly[N-nonyl-3,6-bis(ethylenedioxythiophene)carbazole] matrix for monitoring of phenol derivatives

    Science.gov (United States)

    Jedrychowska, Agnieszka; Malecha, Karol; Cabaj, Joanna; Sołoducho, Jadwiga

    2014-08-01

    The aim of the research was to develop an enzymatic, optical biosensor which provides quick and convenient determination of phenolic compounds in aqueous solutions. The biosensing strategy concerns design, fabrication and testing of a miniature ceramic-based biosensor which is destined for in-situ substrate monitoring. The base of the measuring system was fabricated using low temperature co-fired ceramics (LTCC) technology. The biocatalyst - laccase- was immobilized on the thin film of poly[N-nonyl-3,6-bis(ethylenedioxythiophene)carbazole] which provided good binding of the enzyme to the substrate and positively affected on the catalytic activity of the protein. In order to evaluate properties of the designed biosensor, its response for various concentrations of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diamonnium sal (ABTS) was measured. The optical biosensor produced by presented method could find applications in many fields, i.e. for detection of phenolic compounds in food products and beverages, in industry for control of technological processes or for environmental monitoring

  10. Charge carrier mobility in conjugated organic polymers: simulation of an electron mobility in a carbazole-benzothiadiazole-based polymer

    Science.gov (United States)

    Li, Yaping; Lagowski, Jolanta B.

    2011-08-01

    Inorganic (mostly silicon based) solar cells are important devices that are used to solve the world energy and environmental needs. Now days, organic solar cells are attracting considerable attention in the field of photovoltaic cells because of their low cost and processing flexibility. Often conjugated polymers are used in the construction of the organic solar cells. We study the conjugated polymers' charge transport using computational approach that involves the use of the density functional theory (DFT), semiempirical (ZINDO), and Monte Carlo (MC) theoretical methods in order to determine their transfer integrals, reorganization energies, transfer rates (with the use of Marcus-Hush equation) and mobilities. We employ the experimentally determined three dimensional (3D) structure of poly(9,9'-di-n-octylfluorene-alt-benzothiadiazole) (F8BT) to estimate the electron mobility in a similar co-alternating polymer consisting of carbazole and benzothiadiazole units (C8BT). In agreement with our previous work, we found that including an orientational disorder in the crystal reduces the electron mobility in C8BT. We hope that the proposed computational approach can be used to predict charge mobility in organic materials that are used in solar cells.

  11. Nitrogen-containing microporous conjugated polymers via carbazole-based oxidative coupling polymerization: preparation, porosity, and gas uptake.

    Science.gov (United States)

    Chen, Qi; Liu, De-Peng; Luo, Min; Feng, Li-Juan; Zhao, Yan-Chao; Han, Bao-Hang

    2014-01-29

    Facile preparation of microporous conjugated polycarbazoles via carbazole-based oxidative coupling polymerization is reported. The process to form the polymer network has cost-effective advantages such as using a cheap catalyst, mild reaction conditions, and requiring a single monomer. Because no other functional groups such as halo groups, boric acid, and alkyne are required for coupling polymerization, properties derived from monomers are likely to be fully retained and structures of final polymers are easier to characterize. A series of microporous conjugated polycarbazoles (CPOP-2-7) with permanent porosity are synthesized using versatile carbazolyl-bearing 2D and 3D conjugated core structures with non-planar rigid conformation as building units. The Brunauer-Emmett-Teller specific surface area values for these porous materials vary between 510 and 1430 m(2) g(-1) . The dominant pore sizes of the polymers based on the different building blocks are located between 0.59 and 0.66 nm. Gas (H2 and CO2 ) adsorption isotherms show that CPOP-7 exhibits the best uptake capacity for hydrogen (1.51 wt% at 1.0 bar and 77 K) and carbon dioxide (13.2 wt% at 1.0 bar and 273 K) among the obtained polymers. Furthermore, its high CH4 /N2 and CO2 /N2 adsorption selectivity gives polymer CPOP-7 potential application in gas separation.

  12. Facile Synthesis and High performance of a New Carbazole-Based Hole Transporting Material for Hybrid Perovskite Solar Cells

    KAUST Repository

    Wang, Hong

    2015-06-26

    Perovskite solar cells are very promising for practical applications owing to their rapidly rising power conversion efficiency and low cost of solution-based processing. 2,2’,7,7’-tetrakis-(N,N-di-p-methoxyphenylamine) 9,9’-spirobifluorene (Spiro-OMeTAD) is most widely used as hole transporting material (HTM) in perovskite solar cells. However, the tedious synthesis and high cost of Spiro-OMeTAD inhibit its commercial-scale application in the photovoltaic industry. In this article, we report a carbazole-based compound (R01) as a new HTM in efficient perovskite solar cells. R01 is synthesized via a facile route consisting of only two steps from inexpensive commercially available materials. Furthermore, R01 exhibits higher hole mobility and conductivity than the state-of-the-art Spiro-OMeTAD. Perovskite solar cells fabricated with R01 produce a power conversion efficiency of 12.03%, comparable to that obtained in devices using Spiro-OMeTAD in this study. Our findings underscore R01 as a highly promising HTM with high performance, and its facile synthesis and low cost may facilitate the large-scale applications of perovskite solar cells.

  13. Biofilm lifestyle enhances diesel bioremediation and biosurfactant production in the Antarctic polyhydroxyalkanoate producer Pseudomonas extremaustralis.

    Science.gov (United States)

    Tribelli, Paula M; Di Martino, Carla; López, Nancy I; Raiger Iustman, Laura J

    2012-09-01

    Diesel is a widely distributed pollutant. Bioremediation of this kind of compounds requires the use of microorganisms able to survive and adapt to contaminated environments. Pseudomonas extremaustralis is an Antarctic bacterium with a remarkable survival capability associated to polyhydroxyalkanoates (PHAs) production. This strain was used to investigate the effect of cell growth conditions--in biofilm versus shaken flask cultures--as well as the inocula characteristics associated with PHAs accumulation, on diesel degradation. Biofilms showed increased cell growth, biosurfactant production and diesel degradation compared with that obtained in shaken flask cultures. PHA accumulation decreased biofilm cell attachment and enhanced biosurfactant production. Degradation of long-chain and branched alkanes was observed in biofilms, while in shaken flasks only medium-chain length alkanes were degraded. This work shows that the PHA accumulating bacterium P. extremaustralis can be a good candidate to be used as hydrocarbon bioremediation agent, especially in extreme environments.

  14. Production of biopolymers by Pseudomonas aeruginosa isolated from marine source

    Directory of Open Access Journals (Sweden)

    Nazia Jamil

    2008-06-01

    Full Text Available Two bacterial strains, Pseudomonas aeruginosa CMG607w and CMG1421 produce commercially important biopolymers. CMG607w isolated from the sediments of Lyari outfall to Arabian Sea synthesize the mcl-polyhydroxyalkanoates from various carbon sources. The production of PHAs was directly proportional to the incubation periods. Other strain CMG1421, a dry soil isolate, produced high viscous water absorbing extracellular acidic polysaccharide when it was grown aerobically in the minimal medium containing glucose or fructose or sucrose as sole source of carbon. The biopolymer had the ability to absorb water 400 times more than its dry weight. This property was superior to that of currently used non-degradable synthetic water absorbents. It acted as salt filter and had rheological and stabilizing activity as well.

  15. Glycerol metabolism promotes biofilm formation by Pseudomonas aeruginosa.

    Science.gov (United States)

    Scoffield, Jessica; Silo-Suh, Laura

    2016-08-01

    Pseudomonas aeruginosa causes persistent infections in the airways of cystic fibrosis (CF) patients. Airway sputum contains various host-derived nutrients that can be utilized by P. aeruginosa, including phosphotidylcholine, a major component of host cell membranes. Phosphotidylcholine can be degraded by P. aeruginosa to glycerol and fatty acids to increase the availability of glycerol in the CF lung. In this study, we explored the role that glycerol metabolism plays in biofilm formation by P. aeruginosa. We report that glycerol metabolism promotes biofilm formation by both a chronic CF isolate (FRD1) and a wound isolate (PAO1) of P. aeruginosa. Moreover, loss of the GlpR regulator, which represses the expression of genes involved in glycerol metabolism, enhances biofilm formation in FRD1 through the upregulation of Pel polysaccharide. Taken together, our results suggest that glycerol metabolism may be a key factor that contributes to P. aeruginosa persistence by promoting biofilm formation.

  16. Polysaccharide Degradation

    Science.gov (United States)

    Stone, Bruce A.; Svensson, Birte; Collins, Michelle E.; Rastall, Robert A.

    An overview of current and potential enzymes used to degrade polysaccharides is presented. Such depolymerases are comprised of glycoside hydrolases, glycosyl transferases, phosphorylases and lyases, and their classification, active sites and action patterns are discussed. Additionally, the mechanisms that these enzymes use to cleave glycosidic linkages is reviewed as are inhibitors of depolymerase activity; reagents which react with amino acid residues, glycoside derivatives, transition state inhibitors and proteinaceous inhibitors. The characterization of various enzymes of microbial, animal or plant origin has led to their widespread use in the production of important oligosaccharides which can be incorporated into food stuffs. Sources of polysaccharides of particular interest in this chapter are those from plants and include inulin, dextran, xylan and pectin, as their hydrolysis products are purported to be functional foods in the context of gastrointestinal health. An alternative use of degraded polysaccharides is in the treatment of disease. The possibility exists to treat bacterial exopolysaccharide with lyases from bacteriophage to produce oligosaccharides exhibiting bioactive sequences. Although this area is currently in its infancy the knowledge is available to investigate further.

  17. Halogen effect on structure and 13C NMR chemical shift of 3,6-disubstituted-N-alkyl carbazoles

    DEFF Research Database (Denmark)

    Radula-Janik, Klaudia; Kupka, Teobald; Ejsmont, Krzysztof

    2013-01-01

    Structures of selected 3,6-dihalogeno-N-alkyl carbazole derivatives were calculated at the B3LYP/6-311++G(3df,2pd) level of theory and their 13C NMR isotropic nuclear shieldings were predicted using density functional theory (DFT). The model compounds contained 9H-, N-methyl and N-ethyl derivatives......). The decreasing electronegativity of the halogen substituent (F, Cl, Br and I) was reflected in both nonrelativistic and relativistic NMR results as decreased values of chemical shifts of carbon atoms attached to halogen (C3 and C6) leading to a strong sensitivity to halogen atom type at 3 and 6 positions...

  18. 5′,11′-Dihydrodispiro[cyclohexane-1,6′-indolo[3,2-b]carbazole-12′,1′′-cyclohexane

    Directory of Open Access Journals (Sweden)

    Ilia A. Guzei

    2012-01-01

    Full Text Available The title compound, C28H30N2, is a symmetrical 2:2 product from the condensation of indole and cyclohexanone. It is the only reported 5,11-dihydroindolo[3,2-b]carbazole compound in which the spiro atoms are quaternary C atoms. Crystals were grown by vapor diffusion in a three-zone electric furnace. The molecule resides on a crystallographic inversion center. The cyclohexyl rings are in a slightly distorted chair conformation, whereas the indole units and the spiro-carbons are coplanar within 0.014 Å.

  19. Synthesis of novel precursors of Pfitzinger reaction: A facile one-pot strategy to the synthesis of quinoline carboxylic acid derivatives of pyrazolo-carbazoles and azacarbazoles

    Indian Academy of Sciences (India)

    Ruchi Tyagi; Bhawani Singh; D Kishore

    2012-03-01

    Interaction of 5-indazolyldiazonium chloride 2 with 2-hydroxymethylidene cyclohexanone 5 and -benzyl-3-hydroxymethylidene-4-piperidone 6 under the conditions of Japp-Klingemann reaction, followed by Fischer-indolization of the resulting hydrazones, formed the 5,7,8,9-tetrahydropyrazolo[4,3-b]carbazol- 6(1)-one 9 and 9-benzyl-5,7,8,9-tetrahydropyrido[2',3':4,5]pyrrolo[2,3-f]indazol-6(1)-one 10, respectively. Pfitzinger reaction of 9 and 10 with isatin in alkali afforded the corresponding quinoline carboxylic acid derivatives 12 and 13, respectively.

  20. OXIDATION OF POLYCHLORINATED BIPHENYLS BY PSEUDOMONAS SP. STRAIN LB400 AND PSEUDOMONAS PSEUDOALCALIGENES KF707

    Science.gov (United States)

    Biphenyl-grown cells and cell extracts prepared from biphenyl-grown cells of Pseudomonas sp. strain LB400 oxidize a much wider range of chlorinated biphenyls than do analogous preparations from Pseudomonas pseudoalcaligenes KF707. These results are attributed to differences in th...

  1. Synthesis of rhamnolipid biosurfactant and mode of hexadecane uptake by Pseudomonas species

    Directory of Open Access Journals (Sweden)

    Singh Pooja

    2009-03-01

    Full Text Available Abstract Background Microorganisms have devised ways by which they increase the bioavailability of many water immiscible substrates whose degradation rates are limited by their low water solubility. Hexadecane is one such water immiscible hydrocarbon substrate which forms an important constituent of oil. One major mechanism employed by hydrocarbon degrading organisms to utilize such substrates is the production of biosurfactants. However, much of the overall mechanism by which such organisms utilize hydrocarbon substrate still remains a mystery. Results With an aim to gain more insight into hydrocarbon uptake mechanism, an efficient biosurfactant producing and n-hexadecane utilizing Pseudomonas sp was isolated from oil contaminated soil which was found to produce rhamnolipid type of biosurfactant containing a total of 13 congeners. Biosurfactant action brought about the dispersion of hexadecane to droplets smaller than 0.22 μm increasing the availability of the hydrocarbon to the degrading organism. Involvement of biosurfactant was further confirmed by electron microscopic studies. Biosurfactant formed an emulsion with hexadecane thereby facilitating increased contact between hydrocarbon and the degrading bacteria. Interestingly, it was observed that "internalization" of "biosurfactant layered hydrocarbon droplet" was taking place suggesting a mechanism similar in appearance to active pinocytosis, a fact not earlier visually reported in bacterial systems for hydrocarbon uptake. Conclusion This study throws more light on the uptake mechanism of hydrocarbon by Pseudomonas aeruginosa. We report here a new and exciting line of research for hydrocarbon uptake involving internalization of biosurfactant covered hydrocarbon inside cell for subsequent breakdown.

  2. Morphological, dielectric and electrical conductivity characteristics of clay-containing nanohybrids of poly(N-vinyl carbazole) and polypyrrole.

    Science.gov (United States)

    Haldar, Ipsita; Biswas, Mukul; Nayak, Arabinda; Ray, Suprakas Sinha

    2012-10-01

    Poly(N-vinyl carbazole) (PNVC) and polypyrrole (PPY)-montmorillonite (MMT) clay hybrids were prepared by mechanical grinding of the respective monomers with MMT followed by subsequent standard processing methods. Fourier transform infrared spectroscopic studies confirmed the inclusion of the polymers in the composites. The morphologies of the hybrids were investigated by transmission electron microscopic techniques, which suggested the formation of intercalated structures. X-ray diffraction analyses indicated the enhancement of 'd001' values in MMT implying intercalation of the polymers into the nano-interlamellar spaces of MMT. The dielectric constants of PNVC-MMT hybrids were improved (60-180) relative to the homopolymer (3-6) in the frequency range 0.1-25 kHz. PPY-MMT hybrid also showed significantly higher values of dielectric constant (2000-4000) relative to the corresponding base polymers. These variations were dependent on the MMT/polymer feed ratio in the frequency range (1-25 kHz). This feature could manifest from the characteristic differences in the interfaces between the grains and grain boundaries of the composites, which control the dielectric properties of the system. Relaxation behavior for the composites was explained by considering the Maxwell-Wagner two-layered dielectric models. The ac conductivity was found to be dependent on frequency in the entire frequency range of study (100 Hz to 25 kHz), which indicated that the composites had few free charges for conduction, and frequency dependent conductivity was due to trapped charges in the grain boundary.

  3. Novel carbazole-phenothiazine dyads for dye-sensitized solar cells: a combined experimental and theoretical study.

    Science.gov (United States)

    Marotta, Gabriele; Reddy, Marri Anil; Singh, Surya Prakash; Islam, Ashraful; Han, Liyuan; De Angelis, Filippo; Pastore, Mariachiara; Chandrasekharam, Malapaka

    2013-10-09

    We report a joint experimental and computational work on new organic donor-acceptor dye sensitizers in which a carbazole (CZ) and a phenothiazine (PTZ) units are linked together by an alkyl C6H13, while two different anchoring groups are employed: the cyanoacrylic acid (CS1A, CSORG1) and the rhodanine-3-acetic acid (CS4A, CSORG4). The CZ moiety has multiple roles of (i) acting as an extra-electron donor portion, providing more electron density on the PTZ; (ii) suppressing the back-electron transfer from TiO2 to the electrolyte by forming a compact insulating dye layer; (iii) modulating dye aggregation on the semiconductor surface; and (iv) acting as an antenna, collecting photons and, through long-range energy transfer, redirecting the captured energy to the dye sensitizer. We show that the introduction of the CZ donor remarkably enhances the photovoltaic performances of the rhodanine-based dye, compared to the corresponding simple PTZ dye, with more than a two-fold increase in the overall efficiencies, while it does not bring beneficial effects in the case of the cyanoacrylic-based sensitizer. Based on quantum mechanical calculations and experimental measurements, we show that, in addition to a favored long-range energy transfer, which increases the light absorption in the blue region of the spectrum, the presence of the CZ unit in the CSORG4 dye effectively induces a beneficial aggregation pattern on the semiconductor surface, yielding a broadened and red-shifted light absorption, accounting for the two-fold increase in the generated photocurrent.

  4. A simple strategy for investigating the diversity and hydrocarbon degradation abilities of cultivable bacteria from contaminated soil.

    Science.gov (United States)

    Bučková, Maria; Puškarová, Andrea; Chovanová, Katarína; Kraková, Lucia; Ferianc, Peter; Pangallo, Domenico

    2013-06-01

    The use of indigenous bacterial strains is a valuable bioremediation strategy for cleaning the environment from hydrocarbon pollutants. The isolation and selection of hydrocarbon-degrading bacteria is therefore crucial for obtaining the most promising strains for site decontamination. Two different media, a minimal medium supplemented with a mixture of polycyclic aromatic hydrocarbons and a MS medium supplemented with triphenyltetrazolium chloride, were used for the isolation of bacterial strains from two hydrocarbon contaminated soils and from their enrichment phases. The hydrocarbon degradation abilities of these bacterial isolates were easily and rapidly assessed using the 2,6-dichlorophenol indophenol assay. The diversity of the bacterial communities isolated from these two soil samples and from their enrichment phases was evaluated by the combination of a bacterial clustering method, fluorescence ITS-PCR, and bacterial identification by 16S rRNA sequencing. Different PCR-based assays were performed in order to detect the genes responsible for hydrocarbon degradation. The best hydrocarbon-degrading bacteria, including Arthrobacter sp., Enterobacter sp., Sphingomonas sp., Pseudomonas koreensis, Pseudomonas putida and Pseudomonas plecoglossicida, were isolated directly from the soil samples on minimal medium. The nahAc gene was detected only in 13 Gram-negative isolates and the sequences of nahAc-like genes were obtained from Enterobacter, Stenotrophomonas, Pseudomonas brenneri, Pseudomonas entomophila and P. koreensis strains. The combination of isolation on minimal medium with the 2,6-dichlorophenol indophenol assay was effective in selecting different hydrocarbon-degrading strains from 353 isolates.

  5. Biological Degradation of 2,4,6-Trinitrotoluene

    OpenAIRE

    Esteve-Núñez, Abraham; Caballero, Antonio (fl. 1793); Ramos, Juan L.

    2001-01-01

    Nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. These compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound. Certain strains of Pseudomonas and fungi can use TNT as a nitrogen source through the removal of nitrogen as nitrite from TNT under aerobic conditions and ...

  6. Biotransformations of (+/-)-geosmin by terpene-degrading bacteria.

    Science.gov (United States)

    Eaton, Richard W; Sandusky, Peter

    2010-02-01

    Two terpene-degrading bacteria able to transform (+/-)-geosmin have been identified. Pseudomonas sp. SBR3-tpnb, following growth on gamma-terpinene, converts (+/-)-geosmin to several products; the major products are ketogeosmins. Rhodococcus wratislaviensis DLC-cam, isolated on D-camphor, also converts (+/-)-geosmin to several oxidation products, primarily ketogeosmins identical to those produced by strain SBR3-tpnb as well as hydroxygeosmins. This conversion appears to be inducible by (+/-)-geosmin and not by D-camphor.

  7. Biotransformations of 2-Methylisoborneol by Camphor-Degrading Bacteria ▿

    OpenAIRE

    2008-01-01

    Many camphor-degrading bacteria that are able to transform 2-methylisoborneol (2-MIB) have been identified. Three of these strains have been examined in detail. Rhodococcus ruber T1 metabolizes camphor through 6-hydroxycamphor but converts 2-MIB to 3-hydroxy-2-MIB. Pseudomonas putida G1, which metabolizes camphor through 5-hydroxycamphor, converts MIB primarily to 6-hydroxy-2-MIB. Rhodococcus wratislaviensis DLC-cam converts 2-MIB through 5-hydroxy-2-MIB to 5-keto-2-MIB. Together, these three...

  8. Synthesis and Characterization of Two β-Diketones with Carbazole Group%2个含咔唑基团β-二酮的合成与表征

    Institute of Scientific and Technical Information of China (English)

    唐怀军; 张梅芳; 张志国; 石青; 张克立

    2011-01-01

    以咔唑和联苯为原料合成了2个含咔唑基团的新型β-二酮,并用1H NMR、13C NMR、MS、元素分析、热分析、紫外可见吸收光谱及荧光光谱等测试技术进行了表征.2种β-二酮具有较高的热稳定性,5%失重温 度(△T5%)分别为319和356℃,荧光发射位于蓝光区,最大发射峰为443和455 nm.%Two β-diketones with carbazole group were synthesized from carbazole and biphenyl. The β-diketones were characterized by 'H NMR, 13C NMR, MS, elemental analyses, thermoanalysis, UV-Vis absorption spectra and photoluminescence ( PL) spectra. The β-diketones have high thermal stability, their 5% mass-reduction temperatures( AT5% ) are 319 °C and 356 °C, respectively. Their PL spectra lie in blue light zone with the maximum emission peaks of 443 nm and 455 nm. They are potential ligands for synthesizing metal ion complexes targeted for light-emitting materials.

  9. Doped and non-doped organic light-emitting diodes based on a yellow carbazole emitter into a blue-emitting matrix

    CERN Document Server

    Choukri, H; Forget, S; Chenais, S; Castex, M C; Geffroy, B; Ades, D; Siove, A; Choukri, Hakim; Fischer, Alexis; Forget, Sebastien; Chenais, Sebastien; Castex, Marie-Claude; Geffroy, Bernard; Ades, Dominique; Siove, Alain

    2007-01-01

    A new carbazole derivative with a 3,3'-bicarbazyl core 6,6'-substituted by dicyanovinylene groups (6,6'-bis(1-(2,2'-dicyano)vinyl)-N,N'-dioctyl-3,3'-bicarbazyl; named (OcCz2CN)2, was synthesized by carbonyl-methylene Knovenagel condensation, characterized and used as a component of multilayer organic light-emitting diodes (OLEDs). Due to its -donor-acceptor type structure, (OcCz2CN)2 was found to emit a yellow light at max=590 nm (with the CIE coordinates x=0.51; y = 0.47) and was used either as a dopant or as an ultra-thin layer in a blue-emitting matrix of 4,4'-bis(2,2'-diphenylvinyl)-1,1'-biphenyl (DPVBi). DPVBi (OcCz2CN)2-doped structure exhibited, at doping ratio of 1.5 weight %, a yellowish-green light with the CIE coordinates (x = 0.31; y = 0.51), an electroluminescence efficiency EL=1.3 cd/A, an external quantum efficiency ext= 0.4 % and a luminance L= 127 cd/m2 (at 10 mA/cm2) whereas for non-doped devices utilizing the carbazolic fluorophore as a thin n...

  10. Synthesis, photophysical and charge-transporting properties of a novel asymmetric indolo [3,2-b]carbazole derivative containing benzothiazole and diphenylamino moieties

    Science.gov (United States)

    Shi, Heping; Yuan, Jiandong; Dong, Xiuqing; Cheng, Fangqin

    2014-12-01

    A novel asymmetric donor-π-donor-π-acceptor compound, 2-benzothiazolyl-8-diphenylamino-5,11-dihexylindolo[3,2-b]carbazole (BDDAICZ), has been successfully synthesized by introducing a benzothiazole moiety (as an electron-acceptor) and a diphenylamino moiety (as an electron-donor) to 2-position and 8-position of indolo[3,2-b]carbazole moiety (as a skeleton and an electron-donor), and characterized by elemental analysis, 1H NMR, 13C NMR and MS. The thermal, electrochemical properties of BDDAICZ were characterized by thermogravimetric analysis combined with electrochemistry. The absorption and emission spectra of BDDAICZ was experimentally determined in several solvents and computed using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The calculated absorption and emission wavelengths are coincident with the measured data. The ionization potential (IP), the electron affinity (EA) and reorganization energy of BDDAICZ were also investigated using density functional theory (DFT). Charge-transporting properties of BDDAICZ were characterized by OLEDs devices fabricated by using it as charge-transport layers. The results show that BDDAICZ has excellent thermal stability, electrochemical stability and hole-transporting properties, indicating its potential application as a hole-transporting material in OLEDs devices.

  11. Indolo[3,2-b]carbazole inhibits gap junctional intercellular communication in rat primary hepatocytes and acts as a potential tumor promoter

    DEFF Research Database (Denmark)

    Herrmann, Susan; Seidelin, Michel; Bisgaard, Hanne Cathrine

    2002-01-01

    Indole-3-carbinol (I3C) is a naturally occurring substance that shows anti-carcinogenic properties in animal models. Besides its clear anti-carcinogenic effects, some studies indicate that I3C may sometimes act as a tumor promoter. Indolo[3,2-b]carbazole (ICZ), which is formed in the acidic...... environment of the stomach after intake of I3C, has a similar structure to, and shares biological effects with, the well-known tumor promoter 2,3,7,8-tetrachlorodibenzo-pdioxin (TCDD). Therefore, we hypothesized that ICZ could be responsible for the potential tumor-promoting activity of I3C. The aim...... of the present study was to investigate the effect of ICZ on gap junctional intercellular communication (GJIC) in primary cultured rat hepatocytes co-cultured with the rat liver epithelial cell line WB-F344. Indolo[3,2-b]carbazole inhibited GJIC in the rat hepatocytes in a dose- and time-dependent manner...

  12. OFF-ON-OFF Dual Emission at Visible and UV Wavelengths from Carbazole Functionalized β-Diketonate Europium(III) Complex.

    Science.gov (United States)

    Imai, Yuki; Kawai, Tsuyoshi; Yuasa, Junpei

    2016-06-23

    This work demonstrates dual emission "OFF-ON-OFF" switching at visible and UV wavelengths of a carbazole functionalized β-diketone (LH) by a simple change of a europium(III) ion (Eu(3+)) concentration in the submicromolar concentration range. In the presence of 0.25 equiv of Eu(3+) (5 μM), LH forms a luminescent 4:1 complex ([Eu(3+)(L(-))4](-)) exhibiting dual emission at 357 and 613 nm resulting from the local excitation of the carbazole ring and ligand-sensitized luminescence from the Eu(3+)-β-diketonate unit, respectively. The 4:1 complex begins to convert into a 2:1 complex ([Eu(3+)(L(-))2](+)) via a 3:1 complex [Eu(3+)(L(-))3] above a molar ratio ([Eu(3+)]/[LH]) of 0.25, which provides the opportunity for binding of solvent methanol molecules to the vacant site of the Eu(3+) ion in the complex ([Eu(3+)(L(-))2(MeOH)n](+)). The OH oscillators of coordinated methanol molecules facilitate the nonradiative pathway of the Eu(3+) emission; hence the emission at 613 nm almost disappears above the 0.50 equivalent of Eu(3+) (11 μM), while the UV emission at 357 nm remains mostly constant over the whole concentration range.

  13. Isolation of a strain of Pseudomonas putida capable of metabolizing anionic detergent sodium dodecyl sulfate (SDS

    Directory of Open Access Journals (Sweden)

    A Kumar

    2011-05-01

    Full Text Available Background and objectives: Sodium Dodecyl Sulfate (SDS is one of the most widely used anionic detergents. The present study deals with isolation and identification of SDS-degrading bacteria from a detergent contaminated pond situated in Varanasi city, India."nMaterials and Methods: Employing enrichment technique in minimal medium (PBM, SDS-degrading bacteria were isolated from pond water sample. Rate of degradation of SDS was studied in liquid PBM and also degradation of different concentrations of SDS was also studied to find out maximum concentration of SDS degraded by the potent isolates. Alkyl sulfatase activity (key enzyme in SDS degradation was estimated in crude cell extracts and multiplicity of alkyl sulfatase was studied by Native PAGE Zymography. The potent isolate was identified by 16S rRNA sequence analysis."nResults: Using enrichment technique in minimal medium containing SDS as a sole carbon source, initially three SDS degrading isolates were recovered. However, only one isolate, SP3, was found to be an efficient degrader of SDS. It was observed that this strain could completely metabolize 0.1% SDS in 16 h, 0.2% SDS in 20 h and 0.3% SDS in 24 h of incubation. Specific activity of alkyl sulfatase was 0.087±0.004 μmol SDS/mg protein/min and Native PAGE Zymography showed presence of alkyl sulfatase of Rf value of 0.21. This isolate was identified as Pseudomonas putida strain SP3."nConclusion: This is the report of isolation of SDS-degrading strain of P. putida, which shows high rate of SDS degradation and can degrade up to 0.3% SDS. It appears that this isolate can be exploited for bioremediation of this detergent from water systems.

  14. Genotypische diversiteit en rhizosfeerkolonisatie van DAPG-producerende Pseudomonas spp.

    NARCIS (Netherlands)

    Bergsma-Vlami, M.

    2009-01-01

    Het antibioticum 2,4-diacetylphloroglucinol (DAPG) speelt een belangrijke rol in biologische bestrijding van verschillende plantenpathogenen door fluorescerende Pseudomonas-soorten. DAPG-producerende Pseudomonas-stammen zijn effectief in biologische bestrijding, maar hun saprofytisch vermogen is vaa

  15. Isolation and characterization of endosulfan-degrading bacteria from contaminated agriculture soils

    Institute of Scientific and Technical Information of China (English)

    Mehdi Hassanshahian; Zahra Shahi

    2016-01-01

    Objective: To isolate and characterize endosulfan-degrading bacteria from Kerman pistachio orchards. Methods: Endosulfan-degrading bacteria were enriched in Bushnell-Hass medium. Identification and sequencing of prevalent degrading strains was performed by usingPCR based on amplifying16S rDNA. Results: The results showed that the soils of pistachio orchards have some degrading bacteria that are suitable for elimination of endosulfan from soils and the environment. Four endosulfan-degrading bacteria strains belong toAchromobacter xylosoxidans (strain EN3),Pseudomonas azotoformans (strain EN4),Pseudomonas brassicacearum (strain EN7) andPseudomonas thivervalensis (strain EN8), respectively. The best degrading strain (EN7), up to 100 mg/L, illustrated a good growth, whereas the growth was reduced in concentration higher than 100 mg/L. The results of gas chromatography confirmed the decomposition of organic pesticide by degrading-bacteria. Conclusions: By using these strains and other biological reclamation methods we can eliminate bio-environmental problems.

  16. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  17. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, Helle Krogh; Gøtzsche, Peter C

    2013-01-01

    Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed.......Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed....

  18. Optimization of the solvent-tolerant Pseudomonas putida S12 as host for the production of p-coumarate from glucose

    NARCIS (Netherlands)

    Nijkamp, K.; Westerhof, R.G.M.; Ballerstedt, H.; Bont, J.A.M.de; Wery, J.

    2007-01-01

    A Pseudomonas putida S12 strain was constructed that is able to convert glucose to p-coumarate via the central metabolite l-tyrosine. Efficient production was hampered by product degradation, limited cellular L-tyrosine availability, and formation of the by-product cinnamate via L-phenylalanine. The

  19. Diversity of small RNAs expressed in Pseudomonas species

    DEFF Research Database (Denmark)

    Gomez-Lozano, Mara; Marvig, Rasmus Lykke; Molina-Santiago, Carlos;

    2015-01-01

    RNA sequencing (RNA-seq) has revealed several hundreds of previously undetected small RNAs (sRNAs) in all bacterial species investigated, including strains of Pseudomonas aeruginosa, Pseudomonas putida and Pseudomonas syringae. Nonetheless, only little is known about the extent of conservation of...

  20. 21 CFR 866.3415 - Pseudomonas spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pseudomonas spp. serological reagents. 866.3415... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3415 Pseudomonas spp. serological reagents. (a) Identification. Pseudomonas spp. serological reagents are devices...

  1. Pseudomonas hussainii sp. nov., isolated from droppings of a seashore bird, and emended descriptions of Pseudomonas pohangensis, Pseudomonas benzenivorans and Pseudomonas segetis.

    Science.gov (United States)

    Hameed, Asif; Shahina, Mariyam; Lin, Shih-Yao; Liu, You-Cheng; Young, Chiu-Chung

    2014-07-01

    Two Gram-staining-negative, aerobic, rod-shaped, non-spore-forming bacterial strains that are motile by a monopolar flagellum, designated CC-AMH-11(T) and CC-AMHZ-5, were isolated from droppings of a seashore bird off the coast of Hualien, Taiwan. The strains showed 99.7% mutual pairwise 16S rRNA gene sequence similarity, while exhibiting Pseudomonas (95.7-95.9% similarity with type species, Pseudomonas aeruginosa LMG 1242T), and formed a distinct co-phyletic lineage in the phylogenetic trees. The common major fatty acids (>5% of the total) were C18 : 1ω7c and/or C18 : 1ω6c (summed feature 8), C16 : 1ω6c and/or C16 : 1ω7c (summed feature 3), C16 : 0 and C12 : 0. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine, an unidentified lipid and an unidentified phospholipid were detected as common polar lipids. The DNA G+C contents of strains CC-AMH-11(T) and CC-AMHZ-5 were 61.1 and 61.6 mol%, respectively. The common major respiratory quinone was ubiquinone 9 (Q-9), and the predominant polyamine was putrescine. The DNA-DNA hybridization obtained between the two strains was 79.0% (reciprocal value 89.4% using CC-AMHZ-5 DNA as the probe). The very high 16S rRNA gene sequence similarity and DNA-DNA relatedness and the poorly distinguishable phenotypic features witnessed between CC-AMH-11(T) and CC-AMHZ-5 suggested unambiguously that they are two distinct strains of a single genomic species. However, the strains also showed several genotypic and phenotypic characteristics that distinguished them from other closely related species of Pseudomonas. Thus, the strains are proposed to represent a novel species of Pseudomonas, for which the name Pseudomonas hussainii sp. nov. is proposed. The type strain is CC-AMH-11(T) ( = JCM 19513(T) = BCRC 80696(T)); a second strain of the same species is CC-AMHZ-5 ( = JCM 19512 = BCRC 80697). In addition, emended descriptions of the species Pseudomonas pohangensis, Pseudomonas benzenivorans and

  2. Engineering TCE-degrading rhizobacteria for heavy metal accumulation and enhanced TCE degradation.

    Science.gov (United States)

    Lee, Wonkyu; Wood, Thomas K; Chen, Wilfred

    2006-10-20

    Many superfund sites are currently co-contaminated with organic pollutants such as trichloroethene (TCE) and heavy metals. A promising strategy to address these mixed-waste situations is the use of TCE-degrading rhizobacteria that will survive and thrive in soil heavily polluted with heavy metals. In this work, a gene coding for the metal-binding peptide, EC20, was introduced into rhizobacteria engineered for TCE degradation, resulting in strains with both metal accumulation and TCE degradation capabilities. EC20 was displayed onto the cell surface of Pseudomonas strain Pb2-1 and Rhizobium strain 10320D using an ice-nucleation protein (INP) anchor. Expression of EC20 was confirmed by Western blot analysis and cells with EC20 expression showed sixfold higher cadmium accumulation than non-engineered strains in the presence of 16 microM CdCl(2). As expected, the TCE degradation rate was reduced in the presence of cadmium for cells without EC20 expression. However, expression of EC20 (higher cadmium accumulation) completely restored the level of TCE degradation. These results demonstrated that EC20 expression enhanced not only cadmium accumulation but also reduced the toxic effect of cadmium on TCE degradation. We expect that similar improvements will be observed when these engineered rhizobacteria are inoculated onto plant roots.

  3. Biosurfactant produced by novel Pseudomonas sp. WJ6 with biodegradation of n-alkanes and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Xia, Wenjie; Du, Zhifeng; Cui, Qingfeng; Dong, Hao; Wang, Fuyi; He, Panqing; Tang, YongChun

    2014-07-15

    Alkanes and polycyclic aromatic hydrocarbons (PAHs) have threatened the environment due to toxicity and poor bioavailability. Interest in degradation of these hazardous materials by biosurfactant-producing bacteria has been steadily increasing in recent years. In this work, a novel biosurfactant-producing Pseudomonas sp. WJ6 was isolated to degrade a wide range of n-alkanes and polycyclic aromatic hydrocarbons. Production of lipopeptide biosurfactant was observed in all biodegradable studies. These lipopeptides were purified and identified by C18 RP-HPLC system and electrospray ionization-mass spectrometry. Results of structural analysis showed that these lipopeptides generated from different hydrocarbons were classified to be surfactin, fengycin and lichenysin. Heavy-oil sludge washing experiments demonstrated that lipopeptides produced by Pseudomonas sp. WJ6 have 92.46% of heavy-oil washing efficiency. The obtained results indicate that this novel bacterial strain and its lipopeptides have great potentials in the environmental remediation and petroleum recovery.

  4. Decolorization of Textile Dye Vat Blue 66 by Pseudomonas desmolyticum NCIM 2112 and Bacillus megaterium NCIM 2087

    Directory of Open Access Journals (Sweden)

    Archana A. Gurav

    2011-07-01

    Full Text Available The main objective of this investigation is to detoxify the water insoluble dyes like Vat Blue 66 which is other very difficult to decolorize. Wastewater from the textile and other dyestuff industries contain significant amount of synthetic dyes that require prior treatment to prevent groundwater contamination upon being discharged. The microbial decolorization and degradation of dyes has been of considerable interest biological treatment of the wastewater containing dyes. Pseudomonas desmolyticum NCIM 2112 and Bacillus megatherium NCIM 2087 was able to decolorize indole based dye Vat Blue 66 at pH 9, at 25oC. The addition of glucose and yeast extract in the medium enhanced decolorization process. In this investigation, it has been found that the decolorization of this dye was 70% on an average by oxidative degradation by Pseudomonas desmolyticum NCIM 2112 and Bacillus megaterium NCIM 2087. The decolorization was measured as the decrease in absorbance maxima at 530 nm.

  5. Synthesis of indolo[3,2-b]carbazole-based random copolymers for polymer solar cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Li-Hsin, E-mail: lhchan@ncnu.edu.tw [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou, Taiwan 54561, ROC (China); Lin, Lu-Chi; Yao, Chi-Han [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou, Taiwan 54561, ROC (China); Liu, You-Ren; Jiang, Zong-Jhih [Department of Applied Chemistry, National Chi Nan University, Nantou, Taiwan 54561, ROC (China); Cho, Ting-Yu [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, Nantou, Taiwan 54561, ROC (China)

    2013-10-01

    In addition to preparing two indolocarbazole-based random copolymers (named as r-PICTBT1 and r-PICTBT2), this work investigated their feasibility for bulk heterojunction polymer solar cells (PSCs). These copolymers consisted of commercially available 3,9-dibromo-5,11-dioctyl-5,11-dihydroindole[3,2-b]carbazole, 2,5-bis(trimethylstannyl) thiophene and dibromobenzo[c][1,2,5]thiadiazole by varying the feed in ratios via Stille cross-coupling reactions. The photophysical and electrochemical properties of the resulting copolymers could be fine-modulated easily by adjusting the feed ratios of monomers. Both copolymers in the thin film state exhibited two obvious peaks and a vibronic shoulder in the absorption spectra. Electrochemical experiments indicated that the highest occupied molecular orbital energy levels were − 4.95, − 5.00 eV; meanwhile, the lowest unoccupied molecular orbital energy levels were − 3.38, − 3.54 eV for r-PICTBT1 and r-PICTBT2, respectively. Bulk heterojunction PSCs composed of an electron-donor copolymer blended with an electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PC{sub 61}BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC{sub 71}BM) at a weight ratio of 1:1 or 1:3 were investigated. Moreover, the r-PICTBT2/PC{sub 71}BM-based (w/w = 1:1) PSC performed the best with an open-circuit voltage of 0.54 V, short-circuit current of 6.83 mA/cm{sup 2}, fill factor of 0.44, and power conversion efficiency of 1.63%. - Highlights: • We report two indolocarbazole-based copolymers for photovoltaic applications. • Two copolymers exhibited excellent thermal stability. • Energy levels of copolymers can be modulated by varying the monomers ratios. • Increasing of planar monomer content leads to a relatively smooth morphology. • The optimal device performance reached a power conversion efficiency of 1.63%.

  6. A study on significant microbial interaction leading to decolorization and degradation of textile dye Rubine 3GP.

    Science.gov (United States)

    Phugare, Swapnil S; Kagalkar, Anuradha N; Govindwar, Sanjay P; Jadhav, Jyoti P

    2011-10-01

    The present study evaluates an obligatory interaction between the yeast Saccharomyces cerevisiae NCIM 3312 and the bacterium Pseudomonas sp. strain BCH3 for the biodegradation of the dye Rubin 3GP (R3GP). No significant degradation of R3GP was observed either by Saccharomyces cerevisiae NCIM 3312 or by Pseudomonas sp. strain BCH3, when both the cultures were tested individually under their respective optimum medium conditions. However, when both of them were allowed to intermingle with each other, R3GP was found to be degraded within 72 h, with a steady increase in β -1,3-glucanase, chitinase and protease activity in the culture supernatant; indicating the possible role of Pseudomonas sp. strain BCH3 in cell wall lysis of S. cerevisiae NCIM 3312. The present study elucidates a rare microbial interaction where the bacterium Pseudomonas sp. strain BCH3 utilizes lysed yeast cells as the sole source of nutrients for its own growth and subsequently performs decolorization and degradation of R3GP. Enzymatic status showed involvement of various oxidoreductive enzymes like lignin peroxidase, laccase, DCIP reductase and azo reductase, indicating their role in decolorization and degradation of R3GP. Degradation was confirmed using HPLC, FTIR analysis and the biochemical pathway of degradation was elucidated by using GC-MS analysis.

  7. Biodegradation of Malathion using mixed culture of Serratia marcescens BNA1and Pseudomonas aeruginosa BNA2

    Directory of Open Access Journals (Sweden)

    B Nadalian

    2016-03-01

    Full Text Available Background and Objectives: Organophosphate pesticides are used most commonly for domestic, commercial, and agricultural purposes and have been found to be highly toxic. In essence, bioremediation has become one of the most important tools for removing these compounds in the environment, considering its higher efficiency when compared with the physicochemical methods. Materials and Methods: The biodegradation efficiency of two bacterial strains (i.e. Serratia marcescens BNA1 and Pseudomonas aeruginosa BNA2 were assessed. In order to evaluate Malathion biodegradation, each sample was cultured on mineral salts medium containing Malathion as a sole carbon source. Malathion biodegradation efficiency of the strains was monitored in different culture media. The ability of bacterial isolates to degrade Malathion was studied using gas chromatography. Results: Serratia marcescens BNA1 and Pseudomonas aeruginosa BNA2 were able to degrade Malathion. Biodegradation percentage in different treatments recorded were: BNA1+Ma (33.88%, BNA2+MA (26.45%, BNA1+BNA2+Ma (46/96%, BNA1+Ma+Tween (61.05%, BNA2+Ma+Tween (40.17%, and BNA1+BNA2+Ma+ Tween (67.79%. Conclusion: It could be speculated that the best degradation efficiency can be yielded using mixture of strains plus a surfactant. The results of this study can be used in the bioremediation of Malathion contaminate soil after doing the pilot experiments.

  8. The function of a toluene-degrading bacterial community in a waste gas trickling filter

    DEFF Research Database (Denmark)

    Pedersen, A.R.; Arvin, E.

    1999-01-01

    oligonucleotide 16S ribosomal RNA probe targeting the toluene-degrading species Pseudomonas putida, and by computer simulations (AQUASIM) of the biofilm growth based on a food web model. Biofilms were taken from a lab-scale trickling filter for treatment of toluene-polluted air. The biofilm growth...

  9. Effect of trichloroethylene on the competitive behavior of toluene-degrading bacteria

    NARCIS (Netherlands)

    Mars, Astrid E.; Prins, Gjalt T.; Wietzes, Pieter; Koning, Wim de; Janssen, Dick B.

    1998-01-01

    The influence of trichloroethylene (TCE) on a mixed culture of four different toluene-degrading bacterial strains (Pseudomonas putida mt-2, P. putida F1, P. putida GJ31, and Burkholderia cepacia G4) was studied with a fed-batch culture. The strains were competing for toluene, which was added at a ve

  10. Benzene, toluene and xylene biodegradation by Pseudomonas putida CCMI 852 Biodegradação de benzeno, tolueno e xileno pela Pseudomonas putida CCMI 852

    Directory of Open Access Journals (Sweden)

    Marcelo Henrique Otenio

    2005-09-01

    Full Text Available A minimal liquid medium containing benzene (B, toluene (T and xylene (X and mixtures thereof, was used to evaluate degradation activity of Pseudomonas putida CCMI 852 containing a TOL plasmid. Experiments were developed with B, T and X (100 mg L-1, with mixtures of BT, BX, and TX (50 + 50 mg L-1 each and BTX (33.3 + 33.3 + 33.3 mg L-1 each, added to 500 mL of medium. After 18 to 24 hours, the inoculum was added and solvent disappearance was determined after 24 to 25 hours by GC. Results showed that P. putida CCMI 852 was able to metabolize T and X, but B was not metabolized. In a BTX mixture, B was not metabolized and T and X degradation rate decreased 50%.Meio mineral líquido contendo benzeno (B ou tolueno (T ou xileno (X a 100 mg L-1 e suas misturas de BT, BX e TX (50 + 50 mg L-1 cada mistura e BTX (33,3 + 33,3 + 33,3 mg L-1 cada mistura foram utilizados para avaliar a atividade de degradação de B, T e X por Pseudomonas putida CCMI 852 contendo um plasmídeo TOL. Após 18 a 24 horas de homogenização da mistura, o inoculo foi adicionado e o decréscimo da concentração dos solventes foi determinado entre 24 e 25 horas por GC. Pseudomonas putida CCMI 852 foi capaz de metabolizar T e X, mas não B. Na mistura BTX, B não foi metabolizado também e a velocidade de degradação de T e X decresceu cerca de 50% comparado com soluções contendo apenas T ou X.

  11. Ecofriendly biodegradation and detoxification of Reactive Red 2 textile dye by newly isolated Pseudomonas sp. SUK1.

    Science.gov (United States)

    Kalyani, D C; Telke, A A; Dhanve, R S; Jadhav, J P

    2009-04-30

    The aim of this work is to evaluate textile dyes degradation by novel bacterial strain isolated from the waste disposal sites of local textile industries. Detailed taxonomic studies identified the organisms as Pseudomonas species and designated as strain Pseudomonas sp. SUK1. The isolate was able to decolorize sulfonated azo dye (Reactive Red 2) in a wide range (up to 5 g l(-1)), at temperature 30 degrees C, and pH range 6.2-7.5 in static condition. This isolate also showed decolorization of the media containing a mixture of dyes. Measurements of COD were done at regular intervals to have an idea of mineralization, showing 52% reduction in the COD within 24h. Induction in the activity of lignin peroxidase and azoreductase was observed during decolorization of Reactive Red 2 in the batch culture, which represented their role in degradation. The biodegradation was monitored by UV-vis, IR spectroscopy, HPLC. The final product, 2-naphthol was characterized by GC-mass spectroscopy. The phytotoxicity study revealed the degradation of Reactive Red 2 into non-toxic product by Pseudomonas sp. SUK1.

  12. Ecofriendly biodegradation and detoxification of Reactive Red 2 textile dye by newly isolated Pseudomonas sp. SUK1

    Energy Technology Data Exchange (ETDEWEB)

    Kalyani, D.C.; Telke, A.A.; Dhanve, R.S. [Department of Biochemistry, Shivaji University, Kolhapur 416004 (India); Jadhav, J.P. [Department of Biochemistry, Shivaji University, Kolhapur 416004 (India)], E-mail: jpj_biochem@unishivaji.ac.in

    2009-04-30

    The aim of this work is to evaluate textile dyes degradation by novel bacterial strain isolated from the waste disposal sites of local textile industries. Detailed taxonomic studies identified the organisms as Pseudomonas species and designated as strain Pseudomonas sp. SUK1. The isolate was able to decolorize sulfonated azo dye (Reactive Red 2) in a wide range (up to 5 g l{sup -1}), at temperature 30 deg. C, and pH range 6.2-7.5 in static condition. This isolate also showed decolorization of the media containing a mixture of dyes. Measurements of COD were done at regular intervals to have an idea of mineralization, showing 52% reduction in the COD within 24 h. Induction in the activity of lignin peroxidase and azoreductase was observed during decolorization of Reactive Red 2 in the batch culture, which represented their role in degradation. The biodegradation was monitored by UV-vis, IR spectroscopy, HPLC. The final product, 2-naphthol was characterized by GC-mass spectroscopy. The phytotoxicity study revealed the degradation of Reactive Red 2 into non-toxic product by Pseudomonas sp. SUK1.

  13. Extracytoplasmic function sigma factors in Pseudomonas syringae

    DEFF Research Database (Denmark)

    Kiil, Kristoffer; Oguiza, J.A.; Ussery, D.W.

    2005-01-01

    Genome analyses of the plant pathogens Pseudomonas syringae pv. tomato DC3000, pv. syringae B728a and pv. phaseolicola 1448A reveal fewer extracytoplasmic function (ECF) sigma factors than in related Pseudomonads with different lifestyles. We highlight the presence of a P. syringae-specific ECF...

  14. Plant growth promotion by Pseudomonas fluorescens

    NARCIS (Netherlands)

    Cheng, X.

    2016-01-01

    Pseudomonas fluorescens is a Gram-negative rod shaped bacterium that has a versatile metabolism and is widely spread in soil and water. P. fluorescens strain SBW25 (Pf.SBW25) is a well-known model strain to study bacterial evolution, plant colonization and biocontrol of plant diseases. It produces t

  15. Induced systemic resistance by fluorescent Pseudomonas spp.

    NARCIS (Netherlands)

    Bakker, P.A.H.M.; Pieterse, C.M.J.; Loon, L.C. van

    2007-01-01

    Fluorescent Pseudomonas spp. have been studied for decades for their plant growth-promoting effects through effective suppression of soilborne plant diseases. The modes of action that play a role in disease suppression by these bacteria include siderophore-mediated competition for iron, antibiosis,

  16. Pseudomonas sepsis with Noma: an association?

    Science.gov (United States)

    Vaidyanathan, S; Tullu, M S; Lahiri, K R; Deshmukh, C T

    2005-08-01

    We report here a 2.5-year-old male child with community-acquired Pseudomonal sepsis showing the characteristic lesions of ecthyma gangrenosum. The child had development of gangrenous changes of the nose and face - the 'cancrum oris' or 'Noma'. We highlight the possible association of Pseudomonas sepsis and Noma, with malnutrition playing a central role in causing both the diseases.

  17. New Pseudomonas spp. Are Pathogenic to Citrus.

    Science.gov (United States)

    Beiki, Farid; Busquets, Antonio; Gomila, Margarita; Rahimian, Heshmat; Lalucat, Jorge; García-Valdés, Elena

    2016-01-01

    Five putative novel Pseudomonas species shown to be pathogenic to citrus have been characterized in a screening of 126 Pseudomonas strains isolated from diseased citrus leaves and stems in northern Iran. The 126 strains were studied using a polyphasic approach that included phenotypic characterizations and phylogenetic multilocus sequence analysis. The pathogenicity of these strains against 3 cultivars of citrus is demonstrated in greenhouse and field studies. The strains were initially grouped phenotypically and by their partial rpoD gene sequences into 11 coherent groups in the Pseudomonas fluorescens phylogenetic lineage. Fifty-three strains that are representatives of the 11 groups were selected and analyzed by partial sequencing of their 16S rRNA and gyrB genes. The individual and concatenated partial sequences of the three genes were used to construct the corresponding phylogenetic trees. The majority of the strains were identified at the species level: P. lurida (5 strains), P. monteilii (2 strains), P. moraviensis (1 strain), P. orientalis (16 strains), P. simiae (7 strains), P. syringae (46 strains, distributed phylogenetically in at least 5 pathovars), and P. viridiflava (2 strains). This is the first report of pathogenicity on citrus of P. orientalis, P. simiae, P. lurida, P. moraviensis and P. monteilii strains. The remaining 47 strains that could not be identified at the species level are considered representatives of at least 5 putative novel Pseudomonas species that are not yet described.

  18. High pressure inactivation of Pseudomonas in black truffle - comparison with Pseudomonas fluorescens in tryptone soya broth

    Science.gov (United States)

    Ballestra, Patricia; Verret, Catherine; Cruz, Christian; Largeteau, Alain; Demazeau, Gerard; El Moueffak, Abdelhamid

    2010-03-01

    Pseudomonas is one of the most common genera in black Perigord truffle. Its inactivation by high pressure (100-500 MPa/10 min) applied on truffles at sub-zero or low temperatures was studied and compared with those of Pseudomonas fluorescens in tryptone soya broth. Pressurization of truffles at 300 MPa/4 °C reduced the bacterial count of Pseudomonas by 5.3 log cycles. Higher pressures of 400 or 500 MPa, at 4 °C or 20 °C, allowed us to slightly increase the level of destruction to the value of ca. 6.5 log cycles but did not permit us to completely inactivate Pseudomonas. The results showed a residual charge of about 10 CFU/g. Pressure-shift freezing of truffles, which consists in applying a pressure of 200 MPa/-18 °C for 10 min and then quickly releasing this pressure to induce freezing, reduced the population of Pseudomonas by 3.3 log cycles. The level of inactivation was higher than those obtained with conventional freezing. Endogenous Pseudomonas in truffle was shown to be more resistant to high pressure treatments than P. fluorescens used for inoculation of broths.

  19. [Bioremediation of chlorothalonil-contaminated soil by utilizing Pseudomonas sp. strain CTN-3].

    Science.gov (United States)

    Wang, Guang-Li; Chen, Hong-Hong; Bi, Meng; Li, Shun-Peng

    2012-03-01

    Chlorothalonil is the priority organic pollutant listed by the U.S. Environmental Protection Agency. To utilize the function of microbial degradation in the bioremediation of chlorothalonil-contaminated soil is of practical significance. In this study, a chlorothalonil-degrading Pseudomonas sp. strain CTN-3 isolated from pesticide-contaminated soil was used to examine the chlorothalonil-degrading capacity of the strain and related affecting factors in a microcosm. In sterilized soil, the effect of CTN-3 on chlorothalonil degradation was better than that in unsterilized soil. Various factors, including soil pH, temperature, initial chlorothalonil concentration, and inoculum size, affected the degradation of chlorothalonil by the strain. With the inoculum size of 10(6) CFU x g(-1) soil, the CTN-3 at 15-30 degrees C and pH 5.8-8.3 could effectively degrade 10-200 mg x kg(-1) of chlorothalonil, suggesting that the strain CTN-3 had great potential in the bioremediation of chlorothalonil-contaminated soil.

  20. Biodegradation of acephate and methamidophos by a soil bacterium Pseudomonas aeruginosa strain Is-6.

    Science.gov (United States)

    Ramu, Sasikala; Seetharaman, Barathi

    2014-01-01

    The aim of this study was to isolate and characterize a new acephate-degrading bacteria from agricultural soil and to investigate its biodegradation ability and pathway of degradation. A bacterial strain Is-6, isolated from agriculture soil could completely degrade and utilize acephate as the sole carbon, phosphorus and energy sources for growth in M9 medium. Analysis of the 16S rRNA gene sequence and phenotypic analysis suggested that the strain Is-6 was belonging to the genus Pseudomonas aeruginosa. Strain Is-6 could completely degrade acephate (50 mg L(-1)) and its metabolites within 96 h were identified by high-performance liquid chromatography (HPLC) and electron spray ionization-mass spectrometry (ESI-MS) analyses. When exposed to the higher concentration, the strain Is-6 showed 92% degradation of acephate (1000 mg L(-1)) within 7 days of incubation. It could also utilize dimethoate, parathion, methyl parathion, chlorpyrifos and malathion. The inoculation of strain Is-6 (10(7) cells g(-1)) to acephate (50 mg Kg(-1))-treated soil resulted in higher degradation rate than in noninoculated soils. These results highlight the potential of this bacterium to be used in the cleanup of contaminated pesticide waste in the environment.

  1. Biodegradation of benzidine based azodyes Direct red and Direct blue by the immobilized cells of Pseudomonas fluorescens D41.

    Science.gov (United States)

    Puvaneswari, N; Muthukrishnan, J; Gunasekaran, P

    2002-10-01

    Benzidine based azodyes are proven carcinogens, mutagens and have been linked to bladder cancer of human beings and laboratory animals. The textile and dyestuff manufacturing industry are the two major sources that released azodyes in their effluents. The dye, Direct blue contains two carcinogenic compounds namely benzidine (BZ), 4-amino biphenyl (4-ABP), while the dye Direct red has benzidine (BZ). Among 40 isolates of Pseudomonas fluorescens screened, one isolate designated as D41 was found to be capable of extensively degrading the dyes Direct blue and Direct red. Immobilized cells of P. fluorescens D41 efficiently degraded Direct red (82%) and Direct blue (71%) in the presence of glucose.

  2. Investigation Of The Primary Transcriptome Of The Production Organism Pseudomonas Putida

    DEFF Research Database (Denmark)

    D'Arrigo, Isotta; Bojanovic, Klara; Long, Katherine

    2015-01-01

    Introduction: Pseudomonas putida is a nonpathogenic, Gram-negative bacterium and an excellent model organism for biotechnological applications. Due to its metabolic versatility, P. putida can grow in different environments including in extreme conditions. It has several genes to degrade xenobiotic...... compounds, a capability that renders the bacterium useful in bioremediation. Finally, P. putida shows a high potential as a cell factory for the production of several compounds. Methods: Here, a differential RNA-sequencing approach (dRNA-seq) is used to gain new insights into the organization of the P...

  3. Competition triggers plasmid-mediated enhancement of substrate utilisation in Pseudomonas putida.

    Directory of Open Access Journals (Sweden)

    Hiren Joshi

    Full Text Available Competition between species plays a central role in the activity and structure of communities. Stable co-existence of diverse organisms in communities is thought to be fostered by individual tradeoffs and optimization of competitive strategies along resource gradients. Outside the laboratory, microbes exist as multispecies consortia, continuously interacting with one another and the environment. Survival and proliferation of a particular species is governed by its competitive fitness. Therefore, bacteria must be able to continuously sense their immediate environs for presence of competitors and prevailing conditions. Here we present results of our investigations on a novel competition sensing mechanism in the rhizosphere-inhabiting Pseudomonas putida KT2440, harbouring gfpmut3b-modified Kan(R TOL plasmid. We monitored benzyl alcohol (BA degradation rate, along with GFP expression profiling in mono species and dual species cultures. Interestingly, enhanced plasmid expression (monitored using GFP expression and consequent BA degradation were observed in dual species consortia, irrespective of whether the competitor was a BA degrader (Pseudomonas aeruginosa or a non-degrader (E. coli. Attempts at elucidation of the mechanistic aspects of induction indicated the role of physical interaction, but not of any diffusible compounds emanating from the competitors. This contention is supported by the observation that greater induction took place in presence of increasing number of competitors. Inert microspheres mimicking competitor cell size and concentration did not elicit any significant induction, further suggesting the role of physical cell-cell interaction. Furthermore, it was also established that cell wall compromised competitor had minimal induction capability. We conclude that P. putida harbouring pWW0 experience a competitive stress when grown as dual-species consortium, irrespective of the counterpart being BA degrader or not. The immediate

  4. Genetic evidence of a high-affinity cyanuric acid transport system in Pseudomonas sp. ADP.

    Science.gov (United States)

    Platero, Ana I; Santero, Eduardo; Govantes, Fernando

    2014-03-01

    The Pseudomonas sp. ADP plasmid pADP-1 encodes the activities involved in the hydrolytic degradation of the s-triazine herbicide atrazine. Here, we explore the presence of a specific transport system for the central intermediate of the atrazine utilization pathway, cyanuric acid, in Pseudomonas sp. ADP. Growth in fed-batch cultures containing limiting cyanuric acid concentrations is consistent with high-affinity transport of this substrate. Acquisition of the ability to grow at low cyanuric acid concentrations upon conjugal transfer of pADP1 to the nondegrading host Pseudomonas putida KT2442 suggests that all activities required for this phenotype are encoded in this plasmid. Co-expression of the pADP1-borne atzDEF and atzTUVW genes, encoding the cyanuric acid utilization pathway and the subunits of an ABC-type solute transport system, in P. putida KT2442 was sufficient to promote growth at cyanuric acid concentrations as low as 50 μM in batch culture. Taken together, our results strongly suggest that the atzTUVW gene products are involved in high-affinity transport of cyanuric acid.

  5. Mineralization of a Malaysian crude oil by Pseudomonas sp. and Achromabacter sp. isolated from coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, J.; Ahmad, M.F.

    1995-12-31

    Regarded as being a potentially effective tool to combat oil pollution, bioremediation involves mineralization, i.e., the conversion of complex hydrocarbons into harmless CO{sub 2} and water by action of microorganisms. Therefore, in achieving optimum effectiveness from the application of these products on crude oil in local environments, the capability of the bacteria to mineralize hydrocarbons was evaluated. The microbial laboratory testing of mineralization on local oil degraders involved, first, isolation of bacteria found at a port located on the west coast of Peninsular Malaysia. Subsequently, these bacteria were identified by means of Biomereux`s API 20E and 20 NE systems and later screened by their growth on a Malaysian crude oil. Selected strains of Pseudomonas sp. and Achromabacter sp. were then exposed individually to a similar crude oil in a mineralization unit and monitored for 16 days for release of CO{sub 2}. Pseudomonas paucimobilis was found to produce more CO{sub 2} than Achromobacter sp. When tested under similar conditions, mixed populations of these two taxa produced more CO{sub 2} than that produced by any individual strain. Effective bioremediation of local crude in Malaysian waters can therefore be achieved from biochemically developed Pseudomonas sp. strains.

  6. Attenuation of Pseudomonas aeruginosa biofilm formation by Vitexin: A combinatorial study with azithromycin and gentamicin

    Science.gov (United States)

    Das, Manash C.; Sandhu, Padmani; Gupta, Priya; Rudrapaul, Prasenjit; de, Utpal C.; Tribedi, Prosun; Akhter, Yusuf; Bhattacharjee, Surajit

    2016-03-01

    Microbial biofilm are communities of surface-adhered cells enclosed in a matrix of extracellular polymeric substances. Extensive use of antibiotics to treat biofilm associated infections has led to the emergence of multiple drug resistant strains. Pseudomonas aeruginosa is recognised as a model biofilm forming pathogenic bacterium. Vitexin, a polyphenolic group of phytochemical with antimicrobial property, has been studied for its antibiofilm potential against Pseudomonas aeruginosa in combination with azithromycin and gentamicin. Vitexin shows minimum inhibitory concentration (MIC) at 260 μg/ml. It’s antibiofilm activity was evaluated by safranin staining, protein extraction, microscopy methods, quantification of EPS and in vivo models using several sub-MIC doses. Various quorum sensing (QS) mediated phenomenon such as swarming motility, azocasein degrading protease activity, pyoverdin and pyocyanin production, LasA and LasB activity of the bacteria were also evaluated. Results showed marked attenuation in biofilm formation and QS mediated phenotype of Pseudomonas aeruginosa in presence of 110 μg/ml vitexin in combination with azithromycin and gentamicin separately. Molecular docking of vitexin with QS associated LuxR, LasA, LasI and motility related proteins showed high and reasonable binding affinity respectively. The study explores the antibiofilm potential of vitexin against P. aeruginosa which can be used as a new antibiofilm agent against microbial biofilm associated pathogenesis.

  7. Novel conjugated polymers based on dithieno[3,2-b:6,7-b]carbazole for solution processed thin-film transistors.

    Science.gov (United States)

    Chen, Yagang; Liu, Chengfang; Tian, Hongkun; Bao, Cheng; Zhang, Xiaojie; Yan, Donghang; Geng, Yanhou; Wang, Fosong

    2012-10-26

    Two conjugated polymers (CPs) P-tCzC12 and P-tCzC16 comprising alternating dithieno[3,2-b:6,7-b]carbazole and 4,4'-dihexadecyl-2,2'-bithiophene units have been designed and synthesized. Upon thermal annealing, they can form ordered thin films in which the polymer backbones dominantly adopted an edge-on orientation respective to the substrate with a lamellar spacing of ≈24 Å and a π-stacking distance of ≈3.7 Å. Organic thin-film transistors (OTFTs) were fabricated by solution casting. A hole mobility of 0.39 cm(2) V(-1) s(-1) has been demonstrated with P-tCzC16. This value is the highest among the CPs containing heteroacenes larger than 4 rings.

  8. An unusual case of OD-allotwinning: 9,9′-(2,5-dibromo-1,4-phenylene)bis[9H-carbazole

    Science.gov (United States)

    Kautny, Paul; Schwartz, Thomas; Fröhlich, Johannes

    2017-01-01

    9,9′-(2,5-Dibromo-1,4-phenylene)bis[9H-carbazole] (1) crystallizes as a category I order–disorder (OD) structure composed of non-polar layers of one kind with B2/m(1)1 layer symmetry. The crystals are made up of the two polytypes with a maximum degree of order (MDO). The monoclinic MDO1 polytype (B21/d) possesses an orthorhombic B-centered lattice and appears in two orientations, which are related by reflection at (100). The orthorhombic MDO2 polytype (F2dd) has a doubled b-axis and appears in two orientations, which are related by inversion. The crystal structures of both polytypes were determined in a concurrent refinement. The MDO1:MDO2 ratio is 69:31.

  9. Chain folding controlled by an isomeric repeat unit: helix formation versus random aggregation in acetylene-bridged carbazole-bipyridine co-oligomers.

    Science.gov (United States)

    Divya, Kizhmuri P; Sreejith, Sivaramapanicker; Suresh, Cherumuttathu H; Philips, Divya S; Ajayaghosh, Ayyappanpillai

    2013-07-01

    An unprecedented, positional effect of the isomeric repeat unit on chain folding in donor–acceptor-linked oligomers, which contain alternating bipyridine and carbazole moieties that are connected through an acetylinic linkage, is reported. 4,4′-Linked oligomer 1 adopts an intrachain helical conformation (CD-active) in CHCl3/MeCN (20:80 v/v), whereas oligomer 2, which contains an isomeric 6,6′-linkage, forms interchain randomly coiled aggregates (CD-inactive). The substitution position plays a significant role in controlling the variations in electronic effects and dipole moments around the bipyridyl moiety, which are responsible for this observed phenomenon. Two model compounds of oligomers 1 and 2 (3 and 4, respectively) were prepared and their properties were compared. A systematic investigation of the photophysical and CD properties of these structures, as well as theoretical studies, support our conclusions.

  10. Synthesis, spectral and third-order nonlinear optical properties of terpyridine Zn(II) complexes based on carbazole derivative with polyether group

    Science.gov (United States)

    Kong, Ming; Liu, Yanqiu; Wang, Hui; Luo, Junshan; Li, Dandan; Zhang, Shengyi; Li, Shengli; Wu, Jieying; Tian, Yupeng

    2015-01-01

    Four novel Zn(II) terpyridine complexes (ZnLCl2, ZnLBr2, ZnLI2, ZnL(SCN)2) based on carbazole derivative group were designed, synthesized and fully characterized. Their photophysical properties including absorption and one-photon excited fluorescence, two-photon absorption (TPA) and optical power limiting (OPL) were further investigated systematically and interpreted on the basis of theoretical calculations (TD-DFT). The influences of different solvents on the absorption and One-Photon Excited Fluorescence (OPEF) spectral behavior, quantum yields and the lifetime of the chromophores have been investigated in detail. The third-order nonlinear optical (NLO) properties were investigated by open/closed aperture Z-scan measurements using femtosecond pulse laser in the range from 680 to 1080 nm. These results revealed that ZnLCl2 and ZnLBr2 exhibited strong two-photon absorption and ZnLCl2 showed superior optical power limiting property.

  11. Incorporation of Hexa-peri-hexabenzocoronene (HBC) into Carbazole-Benzo-2,1,3-thiadiazole Copolymers to Improve Hole Mobility and Photovoltaic Performance.

    Science.gov (United States)

    Gao, Chen; Jiang, Pei; Shi, Keli; Ma, Di; Li, Yongfang; Yu, Gui; Li, Xiaoyu; Wang, Haiqiao

    2016-03-04

    Hexa-peri-hexabenzocoronene (HBC) is a discotic-shaped conjugated molecule with strong π-π stacking property, high intrinsic charge mobility, and good self-assembly properties. For a long time, however, organic photovoltaic (OPV) solar cells based on HBC demonstrated low power conversion efficiencies (PCEs). In this study, two conjugated terpolymers, poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5'-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT)-5 HBC and PCDTBT-10 HBC, were synthesized by incorporating different amounts of HBC as the third component into poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5'-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) through Suzuki coupling polymerization. For comparison, the donor-acceptor (D-A) conjugated dipolymer PCDTBT was also synthesized to investigate the effect of HBC units on conjugated polymers. The HBC-containing polymers exhibited higher thermal stabilities, broader absorption spectra, and lower highest-occupied molecular orbital (HOMO) energy levels. In particular, the field-effect mobilities were enhanced by more than one order of magnitude after the incorporation of HBC into the conjugated polymer backbone on account of increased interchain π-π stacking interactions. The bulk heterojunction (BHJ) polymer solar cells (PSCs) fabricated with the polymers as donor and PC71 BM as acceptor demonstrated gradual improvement of open-circuit voltage (VOC ) and short-circuit current (JSC ) with the increase in HBC content. As a result, the PCEs were improved from 3.21 % for PCDTBT to 3.78 % for PCDTBT-5 HBC and then to 4.20 % for PCDTBT-10 HBC.

  12. Photophysics and non-linear absorption of Au(I) and Pt(II) acetylide complexes of a thienyl-carbazole chromophore.

    Science.gov (United States)

    Goswami, Subhadip; Wicks, Geoffrey; Rebane, Aleksander; Schanze, Kirk S

    2014-12-21

    In order to understand the photophysics and non-linear optical properties of carbazole containing π-conjugated oligomers of the type ET-Cbz-TE (E = ethynylene, T = 2,5-thienylene, Cbz = 3,6-carbazole), a detailed investigation was carried out on a series of oligomers that feature Au(i) or Pt(ii) acetylide "end groups", as well as a Pt(ii)-acetylide linked polymer (CBZ-Au-1 and CBZ-Pt-1, CBZ-Poly-Pt). These organometallic chromophores were characterized by UV-visible absorption and variable temperature photoluminescence spectroscopy, nanosecond transient absorption spectroscopy, open aperture nanosecond z-scan and two photon absorption (2PA) spectroscopy. The Au(i) and Pt(ii) oligomers and polymer exhibit weak fluorescence in fluid solution at room temperature. Efficient phosphorescence is observed from the Pt(ii) systems below 150 K in a solvent glass; however, the Au(i) oligomer exhibits only weak phosphorescence at 77 K. Taken together, the emission results indicate that the intersystem crossing efficiency for the Pt(ii) chromophores is greater than for the Au(i) oligomer. Nonetheless, nanosecond transient absorption indicates that direct excitation affords moderately long-lived triplet states for all of the chromophores. Open aperture z-scan measurement shows effective optical attenuation can be achieved by using these materials. The 2PA cross section in the degenerate S0→S1 transition region was in the range 10-100 GM, and increased monotonically toward shorter wavelengths, reaching 800-1000 GM at 550 nm.

  13. Biodegradation of biphenyl and removal of 2-chlorobiphenyl by Pseudomonas sp. KM-04 isolated from PCBs-contaminated mine impacted soil

    Science.gov (United States)

    Nam, I.; Chon, C.; Kim, J.; Kim, Y.

    2013-12-01

    The aim of the present study is to remediate the PCBs contaminated mine soil using microcosm study. For that, the naturally occurring microorganisms are stimulated and enriched in soil itself by supplementing biphenyl as well as benzoic acid. As a result the biphenyl degrading organisms are induced to degrade the PCBs contamination. From the stimulated soil, the biphenyl degrading organisms are isolated and degraded metabolites are elucidated. Pseudomonas sp. strain KM-04 was isolated from PCBs-contaminated soil in a coal mine-impacted area, and identification of bacteria was done by sequencing the 16S rRNA gene analysis. The growth of Pseudomonas sp. strain KM-04 using biphenyl as the sole carbon source was investigated by culturing in 100-mL Erlenmeyer flasks containing 10 ml sterilized MSM and 10 μg/ml biphenyl, and the ability of KM-04 to remove biphenyl and 2-chlorobiphenyl from mine soil was investigated. Metabolite formation was confirmed by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometric analysis. Pseudomonas sp. strain KM-04 uses biphenyl as a sole carbon and energy source, and resting cells convert biphenyl to its metabolic intermediates, including dihydroxybiphenyl, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid, and benzoic acid. Incubation of real soil collected from abandoned mine areas with resting cells of Pseudomonas sp. strain KM-04 for 10 days resulted in the 98.5 % of biphenyl and 82.3 % of 2-chlorobiphenyl in a slurry system. The ability of the Pseudomonas sp. strain KM-04 to bioremediate biphenyl and 2-chlorobiphenyl from abandoned mine soil was examined using soil microcosm studies under laboratory conditions. Treatment of mine soil with the Pseudomonas sp. strain KM-04 for 15 days resulted in 87.1 % reduction in biphenyl and 68.7 % in 2-chlorobiphenyl contents. The results suggest that Pseudomonas sp. strain KM-04 is a potential candidate for the biological removal of biphenyl and chlorinated derivatives

  14. Optimization of Biodegradability and Toxicity Testing of Degradation Product from Linear Alkyl BenzeneSulfonate (LAS) Surfactant as Cleaning Detergent Agent

    OpenAIRE

    2009-01-01

    Optimization of Biodegradability and Toxicity Testing of Degradation Product from Linear Alkyl BenzeneSulfonate (LAS) Surfactant as Cleaning Detergent Agent. Linear Alkyl Benzene Sulfonate (LAS) is a surfactantused in laundry detergent as cleaning agent and toxic to aquatic organisms. Results shows, with the LAS concentrationused (20 ppm) in medium, adaptation time and Acinetobacter sp. growth has shown better biodegradation ability thanthree other bacteria used Pseudomonas putida, Pseudomona...

  15. [Clinical features of Pseudomonas aeruginosa infections].

    Science.gov (United States)

    Sarlangue, J; Brissaud, O; Labrèze, C

    2006-10-01

    Pseudomonas aeruginosa is a ubiquitous environmental organism usually considered as opportunistic pathogen in immunocompromised subjects. However it can produce disease in healthy children, mainly on moist body sites. Familial, community and nosocomial outbreaks of cutaneous infections have been reported. Ecthyma gangrenosum is possible without bacteremia. P. aeruginosa is also the most common cause of otitis externa in swimmers and osteomyelitis after puncture wound of the foot.

  16. Dynamics of Pseudomonas aeruginosa genome evolution

    OpenAIRE

    Mathee, Kalai; Narasimhan, Giri; Valdes, Camilo; Qiu, Xiaoyun; Matewish, Jody M.; Koehrsen, Michael; Rokas, Antonis; Yandava, Chandri N.; Engels, Reinhard; Zeng, Erliang; Olavarietta, Raquel; Doud, Melissa; Smith, Roger S.; Montgomery, Philip; White, Jared R.

    2008-01-01

    One of the hallmarks of the Gram-negative bacterium Pseudomonas aeruginosa is its ability to thrive in diverse environments that includes humans with a variety of debilitating diseases or immune deficiencies. Here we report the complete sequence and comparative analysis of the genomes of two representative P. aeruginosa strains isolated from cystic fibrosis (CF) patients whose genetic disorder predisposes them to infections by this pathogen. The comparison of the genomes of the two CF strains...

  17. Redundancy in putrescine catabolism in solvent tolerant Pseudomonas putida S12.

    Science.gov (United States)

    Bandounas, Luaine; Ballerstedt, Hendrik; de Winde, Johannes H; Ruijssenaars, Harald J

    2011-06-10

    Pseudomonas putida S12 is a promising platform organism for the biological production of substituted aromatic compounds due to its extreme tolerance towards toxic chemicals. Solvent or aromatic stress tolerance may be due to membrane modifications and efflux pumps; however in general, polyamines have also been implicated in stressed cells. Previous transcriptomics results of P. putida strains producing an aromatic compound, or being exposed to the solvent toluene, indicated differentially expressed genes involved in polyamine transport and metabolism. Therefore, the metabolism of the polyamine, putrescine was investigated in P. putida S12, as no putrescine degradation pathways have been described for this strain. Via transcriptome analysis various, often redundant, putrescine-induced genes were identified as being potentially involved in putrescine catabolism via oxidative deamination and transamination. A series of knockout mutants were constructed in which up to six of these genes were sequentially deleted, and although putrescine degradation was affected in some of these mutants, complete elimination of putrescine degradation in P. putida S12 was not achieved. Evidence was found for the presence of an alternative pathway for putrescine degradation involving γ-glutamylation. The occurrence of multiple putrescine degradation routes in the solvent-tolerant P. putida S12 is indicative of the importance of controlling polyamine homeostasis, as well as of the high metabolic flexibility exhibited by this microorganism.

  18. Bioremediation potential of five strains of Pseudomonas sp.

    Directory of Open Access Journals (Sweden)

    Stamenov Dragana R.

    2015-01-01

    Full Text Available Because of their huge biodiversity and metabolic capabilities, the application of microorganisms as bioremediation agents is a way to enhance pollutant degradation. The aim of this research was to investigate the potential of five strains of Pseudomonas sp. as possible bioremediation agents. Strains are from the Collection of the Microbiology Department, Faculty of Agriculture, Novi Sad. Bacterial strains were cultivated in King’s B liquid medium and incubated in shak­er at 28°C. Starter culture was obtained after 24h, CFU 108. This 24h old bacterial culture was used for the analysis of influence of five different natural naphthenic acids. Bacterial growth was determined spectrophotometrically through optical density, after 24h and 48h of growth. Our results showed that two bacterial strains (PS V1 and PS2 had better growth after 48h as they used C from the petroleum derivates. The growth of these strains was increased by 72% and 25% with deri­vates concentration of 10-5 mol/cm3 and 10-6 mol/cm3, respectively. The results of this research showed the potential of certain bacterial strains as bioremediators. [Projekat Ministarstva nauke Republike Srbije, br. TD 31027 i br. III 043002

  19. Solar-energy production and energy-efficient lighting: photovoltaic devices and white-light-emitting diodes using poly(2,7-fluorene), poly(2,7-carbazole), and poly(2,7-dibenzosilole) derivatives.

    Science.gov (United States)

    Beaupré, Serge; Boudreault, Pierre-Luc T; Leclerc, Mario

    2010-02-23

    World energy needs grow each year. To address global warming and climate changes the search for renewable energy sources with limited greenhouse gas emissions and the development of energy-efficient lighting devices are underway. This Review reports recent progress made in the synthesis and characterization of conjugated polymers based on bridged phenylenes, namely, poly(2,7-fluorene)s, poly(2,7-carbazole)s, and poly(2,7-dibenzosilole)s, for applications in solar cells and white-light-emitting diodes. The main strategies and remaining challenges in the development of reliable and low-cost renewable sources of energy and energy-saving lighting devices are discussed.

  20. Induction of the tod Operon by Trichloroethylene in Pseudomonas putida TVA8

    Science.gov (United States)

    Shingleton, Justin T.; Applegate, Bruce M.; Nagel, Aaron C.; Bienkowski, Paul R.; Sayler, Gary S.

    1998-01-01

    Bioluminescence, mRNA levels, and toluene degradation rates in Pseudomonas putida TVA8 were measured as a function of various concentrations of toluene and trichloroethylene (TCE). TVA8 showed an increasing bioluminescence response to increasing TCE and toluene concentrations. Compared to uninduced TVA8 cultures, todC1 mRNA levels increased 11-fold for TCE-treated cultures and 13-fold for toluene-treated cultures. Compared to uninduced P. putida F1 cultures, todC1 mRNA levels increased 4.4-fold for TCE-induced cultures and 4.9-fold for toluene-induced cultures. Initial toluene degradation rates were linearly correlated with specific bioluminescence in TVA8 cultures. PMID:9835608

  1. Rh(III)-Catalyzed Cascade Annulation/C-H Activation of o-Ethynylanilines with Diazo Compounds: One-Pot Synthesis of Benzo[a]carbazoles via 1,4-Rhodium Migration.

    Science.gov (United States)

    Guo, Songjin; Yuan, Kai; Gu, Meng; Lin, Aijun; Yao, Hequan

    2016-10-05

    A Rh(III)-catalyzed cascade annulation/C-H activation of o-ethynylanilines with diazo compounds has been developed. This concise method allows for the rapid formation of a number of benzo[a]carbazoles in high yields, exhibiting good functional group tolerance and scalability. The key to the success of this approach involves one C-N bond and two C-C bond formation, and an aryl-to-aryl 1,4-rhodium migration.

  2. Biodegradation of crude oil by Pseudomonas aeruginosa in the presence of rhamnolipids

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guo-liang; WU Yue-ting; QIAN Xin-ping; MENG Qin

    2005-01-01

    The potential biodegradation of crude oil was assessed based on the development of a fermentative process with a strain ofPseudomonas aeruginosa which produced 15.4 g/L rhamnolipids when cultured in a basal mineral medium using glycerol as a sole carbon source. However, neither cell growth nor rhamnolipid production was observed in the comparative culture system using crude oil as the sole carbon source instead. As rhamnolipid, an effective biosurfactant, has been reported to stimulate the biodegradation of hydrocarbons, 1 g/L glycerol or 0.22 g/L rhamnolipid was initially added into the medium to facilitate the biodegradation of crude oil. In both situations, more than 58% of crude oil was degraded and further converted into accumulated cell biomass and rhamnolipids. These results suggest that Pseudomonas aeruginosa could degrade most of crude oil with direct or indirect addition of rhamnolipid. And this conclusion was further supported by another adsorption experiment, where the adsorption capacity of crude oil by killed cell biomass was negligible in comparison with the biologic activities of live cell biomass.

  3. Degradation kinetics and metabolites in continuous biodegradation of isoprene.

    Science.gov (United States)

    Srivastva, Navnita; Singh, Ram S; Upadhyay, Siddh N; Dubey, Suresh K

    2016-04-01

    The kinetic parameters of isoprene biodegradation were studied in a bioreactor, comprising of bioscrubber and polyurethane foam packed biofilter in series and inoculated with Pseudomonas sp., using a Michaelis-Menten type model. The maximum elimination capacity, ECmax; substrate constant, Ks and ECmax/Ks values for bioscrubber were found to be 666.7 g m(-3) h(-1), 9.86 g m(-3) and 67.56 h(-1), respectively while those for biofilter were 3333 g m(-3) h(-1), 13.96 g m(-3) and 238.7 h(-1), respectively. The biofilter section exhibited better degradation efficiency compared to the bioscrubber unit. Around 62-75% of the feed isoprene got converted to carbon dioxide, indicating the efficient capability of bacteria to mineralize isoprene. The FTIR and GC-MS analyses of degradation products indicated oxidative cleavage of unsaturated bond of isoprene. These results were used for proposing a plausible degradation pathway for isoprene.

  4. PEM fuel cell degradation

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

    2010-01-01

    The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. While significant progress has been made in understanding degradation mechanisms and improving materials, further improvements in durability are required to meet commercialization targets. Catalyst and electrode durability remains a primary degradation mode, with much work reported on understanding how the catalyst and electrode structure degrades. Accelerated Stress Tests (ASTs) are used to rapidly evaluate component degradation, however the results are sometimes easy, and other times difficult to correlate. Tests that were developed to accelerate degradation of single components are shown to also affect other component's degradation modes. Non-ideal examples of this include ASTs examining catalyst degradation performances losses due to catalyst degradation do not always well correlate with catalyst surface area and also lead to losses in mass transport.

  5. Microbial degradation of n-hexadecane in mineral salt medium as mediated by degradative enzymes.

    Science.gov (United States)

    Mishra, Shweta; Singh, S N

    2012-05-01

    In the present study, n-hexadecane degradation in MSM was investigated by three bacteria identified as Pseudomonas aeruginosa PSA5, Rhodococcus sp. NJ2 and Ochrobactrum intermedium P2, isolated from petroleum sludge. During 10 days of incubation, n-hexadecane was degraded to 99% by P. aeruginosa PSA5, 95% by Rhodococcus sp. NJ2 and 92% by O. intermedium P2. During degradation process, the induction of catabolic enzymes alkane hydroxylase, alcohol dehydrogenase and lipase were also examined. Among these enzymes, the highest activities of alkane hydroxylase (185 μmol mg(-1) protein) and alcohol dehydrogenase (75.78 μmol mg(-1) protein) were recorded in Rhodococcus sp. NJ2 while lipase activity was highly induced in P. aeruginosa PSA5 (48.71 μmol mg(-1) protein). Besides, accumulation of n-hexadecane in inclusion bodies was found to be maximum 60.8 g l(-1) in P. aeruginosa PSA5, followed by Rhodococcus sp. NJ2 (56.1 g l(-1)) and the least (51.6 g l(-1)) was found in O. intermedium P2. Biosurfactant production by bacterial strains was indicated by the reduction in surface tension and induction of cell surface hydrophobicity and pseudosolubilization which facilitated n-hexadecane degradation.

  6. An altered Pseudomonas diversity is recovered from soil by using nutrient-poor Pseudomonas-selective soil extract media

    DEFF Research Database (Denmark)

    Aagot, N.; Nybroe, O.; Nielsen, P.

    2001-01-01

    . Several of these analyses showed that the amount of Casamino Acids significantly influenced the diversity of the recovered Pseudomonas isolates. Furthermore, the data suggested that specific Pseudomonas subpopulations were represented on the nutrient-poor media. The NAA 1:100 medium, containing ca. 15 mg......We designed five Pseudomonas-selective soil extract NAA media containing the selective properties of trimethoprim and sodium lauroyl sarcosine and 0 to 100% of the amount of Casamino Acids used in the classical Pseudomonas-selective Gould's S1 medium. All of the isolates were confirmed...

  7. High quality draft genome sequences of Pseudomonas fulva DSM 17717(T), Pseudomonas parafulva DSM 17004(T) and Pseudomonas cremoricolorata DSM 17059(T) type strains.

    Science.gov (United States)

    Peña, Arantxa; Busquets, Antonio; Gomila, Margarita; Mulet, Magdalena; Gomila, Rosa M; Reddy, T B K; Huntemann, Marcel; Pati, Amrita; Ivanova, Natalia; Markowitz, Victor; García-Valdés, Elena; Göker, Markus; Woyke, Tanja; Klenk, Hans-Peter; Kyrpides, Nikos; Lalucat, Jorge

    2016-01-01

    Pseudomonas has the highest number of species out of any genus of Gram-negative bacteria and is phylogenetically divided into several groups. The Pseudomonas putida phylogenetic branch includes at least 13 species of environmental and industrial interest, plant-associated bacteria, insect pathogens, and even some members that have been found in clinical specimens. In the context of the Genomic Encyclopedia of Bacteria and Archaea project, we present the permanent, high-quality draft genomes of the type strains of 3 taxonomically and ecologically closely related species in the Pseudomonas putida phylogenetic branch: Pseudomonas fulva DSM 17717(T), Pseudomonas parafulva DSM 17004(T) and Pseudomonas cremoricolorata DSM 17059(T). All three genomes are comparable in size (4.6-4.9 Mb), with 4,119-4,459 protein-coding genes. Average nucleotide identity based on BLAST comparisons and digital genome-to-genome distance calculations are in good agreement with experimental DNA-DNA hybridization results. The genome sequences presented here will be very helpful in elucidating the taxonomy, phylogeny and evolution of the Pseudomonas putida species complex.

  8. Phytate degradation by fungi and bacteria that inhabit sawdust and coffee residue composts.

    Science.gov (United States)

    Fathallh Eida, Mohamed; Nagaoka, Toshinori; Wasaki, Jun; Kouno, Kenji

    2013-01-01

    Phytate is the primary source of organic phosphorus, but it cannot be directly utilized by plants and is strongly adsorbed by the soil, reducing bioavailability. Composting is a process used to improve the bioavailability of phytate in organic wastes through degradation by microorganisms. In this study, we aimed to investigate the phytate-degrading ability of fungi and bacteria that inhabit sawdust compost and coffee residue compost, and their contribution to the composting process. In the plate assay, the fungi that formed clear zones around their colonies belonged to the genera Mucor, Penicillium, Galactomyces, Coniochaeta, Aspergillus, and Fusarium, while the bacteria belonged to the genera Pseudomonas, Enterobacter, Chitinophaga, and Rahnella. Eight fungal isolates (genera Mucor, Penicillium, Galactomyces, and Coniochaeta) and four bacterial isolates (genera Pseudomonas, Enterobacter, and Rahnella) were selected to evaluate phytase activity in their liquid culture and their ability to degrade phytate in organic materials composed of mushroom media residue and rice bran. The selected fungi degraded phytate in organic materials to varying degrees. Penicillium isolates showed the highest degradation ability and Coniochaeta isolate exhibited relatively high degradation ability. The clear zone diameters of these fungal isolates displayed significantly positive and negative correlations with inorganic and phytate phosphorus contents in the organic materials after incubation, respectively; however, none of the selected bacteria reduced phytate phosphorus in organic materials. It is therefore possible that fungi are major contributors to phytate degradation during composting.

  9. Isolation of bacterial strains able to degrade biphenyl, diphenyl ether and the heat transfer fluid used in thermo-solar plants.

    Science.gov (United States)

    Blanco-Moreno, Rafael; Sáez, Lara P; Luque-Almagro, Víctor M; Roldán, M Dolores; Moreno-Vivián, Conrado

    2017-03-25

    Thermo-solar plants use eutectic mixtures of diphenyl ether (DE) and biphenyl (BP) as heat transfer fluid (HTF). Potential losses of HTF may contaminate soils and bioremediation is an attractive tool for its treatment. DE- or BP-degrading bacteria are known, but up to now bacteria able to degrade HTF mixture have not been described. Here, five bacterial strains which are able to grow with HTF or its separate components DE and BP as sole carbon sources have been isolated, either from soils exposed to HTF or from rhizospheric soils of plants growing near a thermo-solar plant. The organisms were identified by 16S rRNA gene sequencing as Achromobacter piechaudii strain BioC1, Pseudomonas plecoglossicida strain 6.1, Pseudomonas aeruginosa strains HBD1 and HBD3, and Pseudomonas oleovorans strain HBD2. Activity of 2,3-dihydroxybiphenyl dioxygenase (BphC), a key enzyme of the biphenyl upper degradation pathway, was detected in all isolates. Pseudomonas strains almost completely degraded 2000ppm HTF after 5-day culture, and even tolerated and grew in the presence of 150,000ppm HTF, being suitable candidates for in situ soil bioremediation. Degradation of both components of HTF is of particular interest since in the DE-degrader Sphingomonas sp. SS3, growth on DE or benzoate was strongly inhibited by addition of BP.

  10. Preparation of Bio-beads and Their Atrazine Degradation Characteristics

    Institute of Scientific and Technical Information of China (English)

    BI Hai-tao; ZHANG Lan-ying; LIU Na; ZHU Bo-lin

    2011-01-01

    Screened atrazine-mineralizing bacterium-Pseudomonas W4 was embedded inside an improved PVAH3BO3 embedment matrix to make bio-beads to degrade atrazine. The atrazine degradation characteristics were studied. The preparation procedure of bio-beads was as follows: (1) preparing a mixture of 100, 12.5, 10, 1.5 and 1 g/L PVA, bentonite(Ca), activated carbon powder, sodium alginate and centrifuged Pseudomonas W4 bacterium, respectively; (2) the mixture was dropped into a gently stirred cross linker solution(pH=6.7) and cured at 10 ℃ for 24 h.The optimal atrazine degradation conditions by bio-beads were as follows: pH=7, the auxiliary carbon source was glucose, and the concentration of glucose was greater than 325 mg/L. The bio-beads demonstrated stronger tolerance ability than the free microorganism to the increase of PCBs, hydrogen ion and hydroxide ion. SEM images show the uniform distribution of the microorganism inside bio-beads and the porous cross-linked structure of bio-beads which provides excellent mass transfer capacity.

  11. Identification of the para-nitrophenol catabolic pathway, and characterization of three enzymes involved in the hydroquinone pathway, in pseudomonas sp. 1-7

    Directory of Open Access Journals (Sweden)

    Zhang Shuangyu

    2012-03-01

    Full Text Available Abstract Background para-Nitrophenol (PNP, a priority environmental pollutant, is hazardous to humans and animals. However, the information relating to the PNP degradation pathways and their enzymes remain limited. Results Pseudomonas sp.1-7 was isolated from methyl parathion (MP-polluted activated sludge and was shown to degrade PNP. Two different intermediates, hydroquinone (HQ and 4-nitrocatechol (4-NC were detected in the catabolism of PNP. This indicated that Pseudomonas sp.1-7 degraded PNP by two different pathways, namely the HQ pathway, and the hydroxyquinol (BT pathway (also referred to as the 4-NC pathway. A gene cluster (pdcEDGFCBA was identified in a 10.6 kb DNA fragment of a fosmid library, which cluster encoded the following enzymes involved in PNP degradation: PNP 4-monooxygenase (PdcA, p-benzoquinone (BQ reductase (PdcB, hydroxyquinol (BT 1,2-dioxygenase (PdcC, maleylacetate (MA reductase (PdcF, 4-hydroxymuconic semialdehyde (4-HS dehydrogenase (PdcG, and hydroquinone (HQ 1,2-dioxygenase (PdcDE. Four genes (pdcDEFG were expressed in E. coli and the purified pdcDE, pdcG and pdcF gene products were shown to convert HQ to 4-HS, 4-HS to MA and MA to β-ketoadipate respectively by in vitro activity assays. Conclusions The cloning, sequencing, and characterization of these genes along with the functional PNP degradation studies identified 4-NC, HQ, 4-HS, and MA as intermediates in the degradation pathway of PNP by Pseudomonas sp.1-7. This is the first conclusive report for both 4-NC and HQ- mediated degradation of PNP by one microorganism.

  12. Simultaneous removal of Cr(Ⅵ) and phenol in consortium culture of Bacillus sp. and Pseudomonas putida Migula (CCTCC AB92019)

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-guo; PAN Cui; XIA Wen-bin; ZENG Guang-ming; ZHOU Ming; LIU Yuan-yuan; KE Jie; HUANG Chao

    2008-01-01

    The simultaneous removal of Cr(Ⅵ) and phenol in a consortium culture containing Cr(Ⅵ) reducer, Bacillus sp. and phenol degrader, Pseudomonas putida Migula (CCTCC AB92019) was studied. Phenol was used as the sole carbon source. Bacillus sp. utilized metabolites formed from phenol degradation as electron donors and energy source for Cr(Ⅵ) reduction. Optimum Cr(Ⅵ) reduction was observed at a phenol concentration of 150 mg/L and an initial Cr(Ⅵ) concentration of 15 mg/L. Both the Cr(Ⅵ) reduction and phenol degradation were influenced by the cell composition of the culture, but the phenol degradation was not significantly affected by the content of Bacillus sp. The experiments also showed that the amount of phenol degraded was more than that stoichiometrically required for Cr(Ⅵ) reduction.

  13. Pseudomonas salegens sp. nov., a halophilic member of the genus Pseudomonas isolated from a wetland.

    Science.gov (United States)

    Amoozegar, Mohammad Ali; Shahinpei, Azadeh; Sepahy, Abbas Akhavan; Makhdoumi-Kakhki, Ali; Seyedmahdi, Shima Sadat; Schumann, Peter; Ventosa, Antonio

    2014-10-01

    A novel Gram-stain-negative, aerobic, non-endospore-forming, non-pigmented, rod-shaped, slightly halophilic bacterium, designated GBPy5(T), was isolated from aquatic plants of the Gomishan wetland, Iran. Cells of strain GBPy5(T) were motile. Growth occurred with between 1 and 10% (w/v) NaCl and the isolate grew optimally with 3% (w/v) NaCl. The optimum pH and temperature for growth of the strain were pH 8.0 and 30 °C, respectively, while it was able to grow over a pH range of 6.5-9.0 and a temperature range of 4-35 °C. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain GBPy5(T) is a member of the genus Pseudomonas forming a monophyletic branch. The novel strain exhibited 16S rRNA gene sequence similarity of 95.4% with type strains of Pseudomonas guariconensis PCAVU11(T) and Pseudomonas sabulinigri J64(T), respectively. The major cellular fatty acids of the isolate were C18:1ω7c (37.8%), C16:0 (14.9%), C16:1ω7c (12.9%), C12:0 3-OH (7.1%) and C12:0 (7.0%). The polar lipid pattern of strain GBPy5(T) comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and one phospholipid. Ubiquinone 9 (Q-9) was the predominant lipoquinone. The G+C content of the genomic DNA of strain GBPy5(T) was 59.2 mol%. On the basis of the phenotypic and phylogenetic data, strain GBPY5(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salegens sp. nov. is proposed. The type strain is GBPy5(T) ( = IBRC-M 10762(T) = CECT 8338(T)).

  14. Degradation of TCE using sequential anaerobic biofilm and aerobic immobilized bed reactor

    Science.gov (United States)

    Chapatwala, Kirit D.; Babu, G. R. V.; Baresi, Larry; Trunzo, Richard M.

    1995-01-01

    Bacteria capable of degrading trichloroethylene (TCE) were isolated from contaminated wastewaters and soil sites. The aerobic cultures were identified as Pseudomonas aeruginosa (four species) and Pseudomonas fluorescens. The optimal conditions for the growth of aerobic cultures were determined. The minimal inhibitory concentration values of TCE for Pseudomonas sps. were also determined. The aerobic cells were immobilized in calcium alginate in the form of beads. Degradation of TCE by the anaerobic and dichloroethylene (DCE) by aerobic cultures was studied using dual reactors - anaerobic biofilm and aerobic immobilized bed reactor. The minimal mineral salt (MMS) medium saturated with TCE was pumped at the rate of 1 ml per hour into the anaerobic reactor. The MMS medium saturated with DCE and supplemented with xylenes and toluene (3 ppm each) was pumped at the rate of 1 ml per hour into the fluidized air-uplift-type reactor containing the immobilized aerobic cells. The concentrations of TCE and DCE and the metabolites formed during their degradation by the anaerobic and aerobic cultures were monitored by GC. The preliminary study suggests that the anaerobic and aerobic cultures of our isolates can degrade TCE and DCE.

  15. Distribution, diversity, and activity of antibiotic-producing Pseudomonas spp.

    NARCIS (Netherlands)

    Souza, de J.T.

    2002-01-01

    Bacteria of the genus Pseudomonas are potential biocontrol agents of plant diseases caused by various fungi and oomycetes. Antibiotic production is an important trait responsible for the activity of several Pseudomonas strains against plant pathogens. Despite the amount of informati

  16. Facial Nerve Paralysis seen in Pseudomonas sepsis with ecthyma gangrenosum

    Directory of Open Access Journals (Sweden)

    Suleyman Ozdemir

    2013-02-01

    Full Text Available Ecthyma gangrenosum is a skin lesion which is created by pseudomonas auriginosa. Peripheral facial paralysis and mastoiditis as a rare complication of otitis media induced by pseudomonas auriginosa.In this study, 4 months child who has ecthyma gangrenosum and facial nerve paralysis was reported. [Cukurova Med J 2013; 38(1.000: 126-130

  17. Interactions between biosurfactant-producing Pseudomonas and Phytophthora species

    NARCIS (Netherlands)

    Tran, H.

    2007-01-01

    Fluorescent Pseudomonas bacteria produce a wide variety of antimicrobial metabolites, including soap-like compounds referred to as biosurfactants. The results of this thesis showed that biosurfactant-producing Pseudomonas bacteria are effective in controlling Phytophthora foot rot disease of black p

  18. Biosynthesis and regulation of cyclic lipopeptides in Pseudomonas fluorescens

    NARCIS (Netherlands)

    Bruijn, de I.

    2009-01-01

    Cyclic lipopeptides (CLPs) are surfactant and antibiotic metabolites produced by a variety of bacterial genera. For the genus Pseudomonas, many structurally different CLPs have been identified. CLPs play an important role in surface motility of Pseudomonas strains, but also in virulence and attac

  19. Typing of Pseudomonas aeruginosa strains in Norwegian cystic fibrosis patients

    DEFF Research Database (Denmark)

    Fluge, G; Ojeniyi, B; Høiby, N;

    2001-01-01

    OBJECTIVES: Typing of Pseudomonas aeruginosa isolates from Norwegian cystic fibrosis (CF) patients with chronic Pseudomonas lung infection in order to see whether cross-infection might have occurred. METHODS: Isolates from 60 patients were collected during the years 1994-98, and typed by pulsed...

  20. Verspreiding, diversiteit en activiteit van antibioticaproducerende Pseudomonas spp

    NARCIS (Netherlands)

    Souza, J.T.

    2003-01-01

    Pseudomonas bacteriën zijn potentiële antagonisten van diverse plantenpathogene schimmels en oömyceten. De productie van antibiotica speelt een belangrijke rol in de activiteit van diverse Pseudomonas isolaten tegen plantenpathogenen. Dit artikel is een samenvatting van het proefschrift getiteld 'Di

  1. Pseudomonas Exotoxin A: optimized by evolution for effective killing

    Directory of Open Access Journals (Sweden)

    Marta eMichalska

    2015-09-01

    Full Text Available Pseudomonas Exotoxin A (PE is the most toxic virulence factor of the pathogenic bacterium Pseudomonas aeruginosa. This review describes current knowledge about the intoxication pathways of PE. Moreover, PE represents a remarkable example for pathoadaptive evolution, how bacterial molecules have been structurally and functionally optimized under evolutionary pressure to effectively impair and kill their host cells.

  2. Anthranilate deteriorates the structure of Pseudomonas aeruginosa biofilms and antagonizes the biofilm-enhancing indole effect.

    Science.gov (United States)

    Kim, Soo-Kyoung; Park, Ha-Young; Lee, Joon-Hee

    2015-04-01

    Anthranilate and indole are alternative degradation products of tryptophan, depending on the bacterial species. While indole enhances the biofilm formation of Pseudomonas aeruginosa, we found that anthranilate, the tryptophan degradation product of P. aeruginosa, had an opposite effect on P. aeruginosa biofilm formation, in which anthranilate deteriorated the mushroom structure of biofilm. The anthranilate effect on biofilm formation was differentially exerted depending on the developmental stage and the presence of shear force. Anthranilate slightly accelerated the initial attachment of P. aeruginosa at the early stage of biofilm development and appeared to build more biofilm without shear force. But anthranilate weakened the biofilm structure in the late stage, deteriorating the mushroom structure of biofilms with shear force to make a flat biofilm. To investigate the interplay of anthranilate with indole in biofilm formation, biofilms were cotreated with anthranilate and indole, and the results showed that anthranilate antagonized the biofilm-enhancing effect of indole. Anthranilate was able to deteriorate the preformed biofilm. The effect of anthranilate and indole on biofilm formation was quorum sensing independent. AntR, a regulator of anthranilate-degrading metabolism was synergistically activated by cotreatment with anthranilate and indole, suggesting that indole might enhance biofilm formation by facilitating the degradation of anthranilate. Anthranilate slightly but significantly affected the cyclic diguaniylate (c-di-GMP) level and transcription of major extracellular polysaccharide (Psl, Pel, and alginate) operons. These results suggest that anthranilate may be a promising antibiofilm agent and antagonize the effect of indole on P. aeruginosa biofilm formation.

  3. Purification and Properties of an Extracellular Polyhydroxybutyrate Depolymerase from Pseudomonas mendocina DSWY0601

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; LI Fan; WANG Zhan-yong; LIU Dong-bo; XIA Hong-mei; LIU Ling-fei; CHEN Shan

    2012-01-01

    An extracellular polyhydroxybutyrate(PHB) depolymerase was purified to homogeneity from the culture supematant of a PHB-degrading bacterium,Pseudomonas mendocina DSWY0601,which was isolated from brewery sewage for the ability to form clear zones on the PHB mineral agar plates.The molecular weight of the purified PHB depolymerase as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) was approximately 59800 at the optimal temperature and pH value being 50℃ and 8.5,respectively.PHB depolymerase was stable in a temperature rangc of 20--50℃ and sensitive to pH value within a pH range of 8.0--9.5.PHB depolymerase degraded poly-3-hydroxybutyrate-co-4-hydroxybutyrate(P3/4HB) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate(PHBV) but did not degrade poly(lactic acid)(PLA),poly(butylene succinate)(PBS) or poly(caprolactone)(PCL).PHB depolymerase was sensitive to phenylmethylsulfonyl fluoride(PMSF),H2O2 and SDS.The main product after enzymatic degradation of PHB was indentified as 3-hydroxbutyrate monomer(3HB) by mass spectrometric analysis,suggesting that PHB depolymerase acted as an exo-type hydrolase.Analysis ofphaZpm gene reveals that PHB depolymerase is a typical denatured short-chain-length PHA(dPHAscL,PHA=polyhydroxyalkanoate)depolymerase containing catalytic domain,linker and substrate-binding domain.

  4. Substitution of Carbazole Modified Fluorenes as π-Extension in Ru(II Complex-Influence on Performance of Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Malapaka Chandrasekharam

    2011-01-01

    Full Text Available A new high molar extinction coefficient ruthenium(II bipyridyl complex “cis-Ru(4,4-bis(9,9-dibutyl-7-(3,6-di-tert-butyl-9H-carbazol-9-yl-9H-fluoren-2-yl-2,2-bipyridine(2,2-bipyridine-4,4-dicarboxylic acid(NCS2, BPFC” has been synthesized and characterized by FT-IR, 1H-NMR, and ESI-MASS spectroscopes. The sensitizer showed molar extinction coefficient of 18.5×103 M−1cm−1, larger as compared to the reference N719, which showed 14.4×103 M−1cm−1. The test cells fabricated using BPFC sensitizer employing high performance volatile electrolyte, (E01 containing 0.05 M I2, 0.1 M LiI, 0.6 M 1,2-dimethyl-3-n-propylimidazolium iodide, 0.5 M 4-tert-butylpyridine in acetonitrile solvent, exhibited solar-to-electric energy conversion efficiency (η of 4.65% (short-circuit current density (SC = 11.52 mA/cm2, open-circuit voltage (OC = 566 mV, fill factor = 0.72 under Air Mass 1.5 sunlight, lower as compared to the reference N719 sensitized solar cell, fabricated under similar conditions, which exhibited η-value of 6.5% (SC = 14.3 mA/cm2, OC = 640 mV, fill factor = 0.71. UV-Vis measurements conducted on TiO2 films showed decreased film absorption ratios for BPFC as compared to those of reference N719. Staining TiO2 electrodes immediately after sonication of dye solutions enhanced film absorption ratios of BPFC relative to those of N719. Time-dependent density functional theory (TD-DFT calculations show higher oscillation strengths for 4,4-bis(9,9-dibutyl-7-(3,6-di-tert-butyl-9H-carbazol-9-yl-9H-fluoren-2-yl-2,2-bipyridine relative to 2,2-bipyridine-4,4-dicarboxylic acid and increased spectral response for the corresponding BPFC complex.

  5. Identification of Comamonas testosteroni as an androgen degrader in sewage

    Science.gov (United States)

    Chen, Yi-Lung; Wang, Chia-Hsiang; Yang, Fu-Chun; Ismail, Wael; Wang, Po-Hsiang; Shih, Chao-Jen; Wu, Yu-Ching; Chiang, Yin-Ru

    2016-01-01

    Numerous studies have reported the masculinization of freshwater wildlife exposed to androgens in polluted rivers. Microbial degradation is a crucial mechanism for eliminating steroid hormones from contaminated ecosystems. The aerobic degradation of testosterone was observed in various bacterial isolates. However, the ecophysiological relevance of androgen-degrading microorganisms in the environment is unclear. Here, we investigated the biochemical mechanisms and corresponding microorganisms of androgen degradation in aerobic sewage. Sewage samples collected from the Dihua Sewage Treatment Plant (Taipei, Taiwan) were aerobically incubated with testosterone (1 mM). Androgen metabolite analysis revealed that bacteria adopt the 9, 10-seco pathway to degrade testosterone. A metagenomic analysis indicated the apparent enrichment of Comamonas spp. (mainly C. testosteroni) and Pseudomonas spp. in sewage incubated with testosterone. We used the degenerate primers derived from the meta-cleavage dioxygenase gene (tesB) of various proteobacteria to track this essential catabolic gene in the sewage. The amplified sequences showed the highest similarity (87–96%) to tesB of C. testosteroni. Using quantitative PCR, we detected a remarkable increase of the 16S rRNA and catabolic genes of C. testosteroni in the testosterone-treated sewage. Together, our data suggest that C. testosteroni, the model microorganism for aerobic testosterone degradation, plays a role in androgen biodegradation in aerobic sewage. PMID:27734937

  6. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, H.K.; Gøtzsche, Peter C.; Johansen, Helle Krogh

    2008-01-01

    BACKGROUND: Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed. OBJECTIVES......: To assess the effectiveness of vaccination against Pseudomonas aeruginosa in cystic fibrosis. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register using the terms vaccines AND pseudomonas (last search May 2008) and PubMed using the terms vaccin* AND cystic...... fibrosis (last search May 2008). SELECTION CRITERIA: Randomised trials (published or unpublished) comparing Pseudomonas aeruginosa vaccines (oral, parenteral or intranasal) with control vaccines or no intervention in cystic fibrosis. DATA COLLECTION AND ANALYSIS: The authors independently selected trials...

  7. Growth of Pseudomonas spp. in cottage cheese

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Dalgaard, Paw

    Cottage cheese is a mixture of cheese curd with pH 4.5-4.8 and an uncultured or cultured cream dressing with a pH as high as 7.0. This results in a final product with microenvironments and a bulk pH of about 4.8 to 5.5. As for other lightly preserved foods microbial contamination and growth...... of spoilage microorganisms in cottage cheese can cause undesirable alterations in flavour, odour, appearance and texture. Contamination and growth of psychrotolerant pseudomonads including Pseudomonas fragi and Pseudomonas putida has been reported for cottage cheese but the influence of these bacteria......H (4.9-7.0) on growth was quantified using automated absorbance measurements (Bioscreen C). A pronounced reduction of the maximum specific growth rate was observed at pH 4.9 but at pH 5.2 strains grew at 5˚C, 10˚C and 15˚C. Challenge tests at 5-15˚C with cottage cheese (pH 5.2-5.5), and cream dressing...

  8. Biotransformation of myrcene by Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hashemi Elham

    2011-05-01

    Full Text Available Abstract Background Dihydrolinalool and terpineol are sources of fragrances that provide a unique volatile terpenoid alcohol of low toxicity and thus are widely used in the perfumery industry, in folk medicine, and in aromatherapy. They are important chemical constituents of the essential oil of many plants. Previous studies have concerned the biotransformation of limonene by Pseudomonas putida. The objective of this research was to study biotransformation of myrcene by Pseudomonas aeruginosa. The culture preparation was done using such variables as different microbial methods and incubation periods to obtain maximum cells of P. aeruginosa for myrcene biotransformation. Results It was found that myrcene was converted to dihydrolinalool and 2,6-dimethyloctane in high percentages. The biotransformation products were identified by Fourier-transform infrared spectroscopy (FT-IR, ultraviolet (UV analysis, gas chromatography (GC, and gas chromatography-mass spectroscopy (GC-MS. Comparison of the different incubation times showed that 3 days was more effective, the major products being 2,6-dimethyloctane (90.0% and α-terpineol (7.7% and comprising 97.7%. In contrast, the main compounds derived for an incubation time of 1.5 days were dihydrolinalool (79.5% and 2,6-dimethyloctane (9.3%, with a total yield of 88.8%.

  9. Biosensor for Direct Determination of Fenitrothion and EPN Using Recombinant Pseudomonas putida JS444 with Surface Expressed Organophosphorus Hydrolase. 1. Modified Clark Oxygen Electrode

    OpenAIRE

    2006-01-01

    This paper reports a first microbial biosensor for rapid and cost-effective determination of organophosphorus pesticides fenitrothion and EPN. The biosensor consisted of recombinant PNP-degrading/oxidizing bacteria Pseudomonas putida JS444 anchoring and displaying organophosphorus hydrolase (OPH) on its cell surface as biological sensing element and a dissolved oxygen electrode as the transducer. Surface-expressed OPH catalyzed the hydrolysis of fenitrothion and EPN to release 3-methyl-4-nitr...

  10. Sequential Isolation of Saturated, Aromatic, Resinic and Asphaltic Fractions Degrading Bacteria from Oil Contaminated Soil in South Sumatera

    Directory of Open Access Journals (Sweden)

    Pingkan Aditiawati

    2012-04-01

    Full Text Available Sequential isolation has been conducted to obtain isolates of saturated, aromatic, resin, and asphaltene fractions degrading bacteria from oil contaminated sites. Five soil samples were collected from South Sumatera. These were analyzed using soil extract medium enriched with oil recovery or Remaining-Oil recovery Degradated (ROD as sole carbon and energy sources according to the isolation stage. ROD at the end of every isolation stage analyzed oil fractions by use of the SARA analysis method. Six isolates of bacteria have been selected, one isolate was fraction saturates degrading bacteria that are Mycobacterium sp. T1H2D4-7 at degradation rate 0.0199 mgs/h with density 8.4x106 cfu/g from stage I. The isolate T2H1D2-4, identified as Pseudomonas sp. was fraction aromatics degrading bacteria at accelerate 0.0141 mgs/h with density 5.1x106 cfu/g are obtained at stage II. Two isolates namely Micrococcus sp. T3H2D4-2 and Pseudomonas sp. T1H1D5-5 were fraction resins degrading bacteria by accelerate 0.0088 mgs/h at density 5.6x106 cfu/g and 0.0089 mgs/h at density 5.7x106 cfu/g are obtained at stage III. Isolation of stage IV has been obtained two isolates Pseudomonas sp. T4H1D3-1and Pseudomonas sp. T4H3D5-4 were fraction asphaltenes degrading bacteria by accelerate 0.0057 mgs/h at density 5.6x106 cfu/g and accelerate 0.0058 mgs/h at density 5.7x106 cfu/g.

  11. Degradation behaviors of nonylphenol ethoxylates by isolated bacteria using improved isolation method

    Institute of Scientific and Technical Information of China (English)

    GU Xin; ZHANG Yu; ZHANG Jing; YANG Min; Hideyuki Tamaki; Yoichi Kamagata

    2008-01-01

    Nonylphenol ethoxylate (NPEO)-degrading bacteria were isolated from activated sludge using an improved isolation method, and the corresponding degradation behaviours were investigated. Eight NPEO-degrading strains distributed in genera Pseudomonas, Sphingomonas, Sphingobium, Cupriavidus, Ralstonia, Achromobacter, and Staphylococcus were acquired. The latter five genera have never been reported for the degradation of NPEOs. Four degradation patterns were observed for the eight pure strains. In pattern A, NPEOs were converted to short-chain NPEOs and carboxylated products, while in pattern B, lower ethoxylated oligomers appeared. Nonylphenol monoethoxylate was the main product in pattern C, while in pattern D ethoxylated units was oxidized but not shortened. Pattern C and D have not yet been reported.

  12. Thraustochytrid protists degrade hydrocarbons

    Digital Repository Service at National Institute of Oceanography (India)

    Raikar, M.T.; Raghukumar, S.; Vani, V.; David, J.J.; Chandramohan, D.

    Rev, 54 (1990) 305-315. 12 Fedorak P M & Westlake D W S, Microbial degradation of aromatics and saturates in Prudhoe Bay crude oil as determined by glass capillary gas chromatography, Can J Microbiol, (1981) 432-443. 13 Atlas R M, Microbial... degradation of petroleum hydrocarbons: An environmental perspective, Microbiol Rev, 45 (1981) 180-209. 14 Atlas R M, Microbial hydrocarbon degradation- Bioremediation of oil spills, J Chem Tech Biotechnol, 52 (1991) 149-156 15 Venkateswaran K, Iwabuchi T...

  13. Screening and Characterization of Proline Dehydrogenase Flavoenzyme Producing Pseudomonas Entomophila

    Directory of Open Access Journals (Sweden)

    H Shahbaz- Mohammadi

    2011-12-01

    Full Text Available Background and Objectives: Proline dehydrogenase (ProDH; 1.5.99.8 plays an important role in specific determination of plasma proline level in biosensor and diagnostic kits. The goal of this research was to isolate and characterize ProDH enzyme from Iranian soil microorganisms.Materials and Methods: Screening of L-proline degradative enzymes from soil samples was carried out employing enrichment culture techniques. The isolate was characterized by biochemical reactions and specific PCR amplification. The target ProDH was purified and the effects of pH and temperature on the activity and stability were also tested.Results: Among the 250 isolates recovered from 40 soil samples, only one strain characterized as Pseudomonas entomophila displayed the highest enzyme activity toward L-proline (350 U/l than others. The enzyme of interest was identified as a ProDH and had Km value of 32 mM for L-proline. ProDH exhibited its best activity at temperature range of 25 to 35°C and its highest activity was achieved at 30°C. It was almost stable at temperatures between 25-30°C for 2 hours. The optimum pH activity of ProDH reaction was 8.5 and its activity was stable in pH range of 8.0-9.0 upto 24 hours. The enzyme was purified with a yield of 8.5% and a purification factor of 37.7. The molecular mass of the purified ProDH was about 40 kDa, and determined to be a monomeric protein."nConclusion: This is the first report concerning the ProDH production by a P. entomophila bacterium isolated from soil sample.

  14. D-π-A-π-A Strategy to Design Benzothiadiazole-carbazole-based Conjugated Polymer with High Solar Cell Voltage and Enhanced Photocurrent.

    Science.gov (United States)

    Zhou, Manxi; Wang, Min; Zhu, Lei; Yang, Zhenqing; Jiang, Chao; Cao, Dapeng; Li, Qifang

    2015-12-01

    The theoretical calculations are used to find that D-π-A-π-A style conjugated polymer PC-TBTBT is more efficient for solar cells application than the D-π-A analog PC-TBT because the D-π-A-π-A structure has a narrower band gap and higher molar absorption coefficient and redshift spectrum. Motivated by the theoretical prediction, 5,6-bis(octyloxy)-2,1,3-benzothiadiazole and 2,7-carbazole are adopted to synthesize the D-π-A-π-A style PC-TBTBT (M(w) = 31.1 kDa) and D-π-A analog PC-TBT (M(w) = 87.5 kDa) by Suzuki coupling reaction. Experimental results confirm that D-π-A-π-A PC-TBTBT-based solar cell shows a power conversion efficiency (PCE) of 4.74% with high V(OC) of 0.99 V and enhanced J(SC) of 9.70 mA cm(-2). The PCE and J(SC) achieve improvements of 17% and 26%, respectively, compared to the D-π-A PC-TBT-based solar cell.

  15. Design and synthesis of new benzimidazole-carbazole conjugates for the stabilization of human telomeric DNA, telomerase inhibition, and their selective action on cancer cells.

    Science.gov (United States)

    Maji, Basudeb; Kumar, Krishan; Kaulage, Mangesh; Muniyappa, K; Bhattacharya, Santanu

    2014-08-28

    Cell-permeable small molecules that enhance the stability of the G-quadruplex (G4) DNA structures are currently among the most intensively pursued ligands for inhibition of the telomerase activity. Herein we report the design and syntheses of four novel benzimidazole-carbazole conjugates and demonstrate their high binding affinity to G4 DNA. S1 nuclease assay confirmed the ligand mediated G-quadruplex DNA protection. Additional evidence from Telomeric Repeat Amplification Protocol (TRAP-LIG) assay demonstrated efficient telomerase inhibition activity by the ligands. Two of the ligands showed IC50 values in the sub-micromolar range in the TRAP-LIG assay, which are the best among the benzimidazole derivatives reported so far. The ligands also exhibited cancer cell selective nuclear internalization, nuclear condensation, fragmentation, and eventually antiproliferative activity in long-term cell viability assays. Annexin V-FITC/PI staining assays confirm that the cell death induced by the ligands follows an apoptotic pathway. An insight into the mode of ligand binding was obtained from the molecular dynamics simulations.

  16. New dimeric carbazole-benzimidazole mixed ligands for the stabilization of human telomeric G-quadruplex DNA and as telomerase inhibitors. A remarkable influence of the spacer.

    Science.gov (United States)

    Maji, Basudeb; Kumar, Krishan; Muniyappa, K; Bhattacharya, Santanu

    2015-08-14

    The development of G-quadruplex (G4) DNA binding small molecules has become an important strategy for selectively targeting cancer cells. Herein, we report the design and evolution of a new kind of carbazole-based benzimidazole dimers for their efficient telomerase inhibition activity. Spectroscopic titrations reveal the ligands high affinity toward the G4 DNA with significantly higher selectivity over duplex-DNA. The electrophoretic mobility shift assay shows that the ligands efficiently promote the formation of G4 DNA even at a lower concentration of the stabilizing K(+) ions. The TRAP-LIG assay demonstrates the ligand's potential telomerase inhibition activity and also establishes that the activity proceeds via G4 DNA stabilization. An efficient nuclear internalization of the ligands in several common cancer cells (HeLa, HT1080, and A549) also enabled differentiation between normal HFF cells in co-cultures of cancer and normal ones. The ligands induce significant apoptotic response and antiproliferative activity toward cancer cells selectively when compared to the normal cells.

  17. A rectifying diode with hysteresis effect from an electroactive hybrid of carbazole-functionalized polystyrene with CdTe nanocrystals via electrostatic interaction

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    One of the strategies to tune current-voltage behaviors in organic diodes is to combine field-induced charge transfer processes with schottky barrier.According to this principle,a rectifying diode with hysteresis effect was fabricated utilizing a hybrid of electroactive polystyrene derivative covalently tethered with electron-donor carbazole moieties and electrostatic linked with electron-acceptor CdTe nanocrystals.Current-voltage characteristics show an electrical switching behavior with some hysteresis is only observed under a negative bias,with three orders of On/Off current ratio.The hybrid material based rectifier exhibits a rectification ratio of six and its maximum rectified output current is about 5 × 10-5 A.The asymmetric switching is interpreted as the result of both field induced charge transfer and schottky barrier,capable of reducing the misreading of cross-bar memory.Meanwhile,chemical doping of CdTe nanocrystals instead of physical blend favor their uniform dispersion in matrix and stable operation of device.

  18. 1,4,9,12-Tetramethoxy-14-octyl-5,8-dihydrodiindolo[3,2-b;2′,3′-h]carbazole with an unknown solvent

    Directory of Open Access Journals (Sweden)

    Norma Wrobel

    2017-03-01

    Full Text Available The title compound, 2C36H39N3O4·H2O, is a linear π-conjugated ladder oligomer with an alkyl chain on the central nitrogen atom. This diindolocarbazole, prepared via a twofold Cadogan reaction, adopts a sligthly convex shape, anti to the disordered octyl group. The unit cell contains nine molecules of the title compound and half a water molecule per main molecule. The water molecule forms hydrogen bridges, connecting the carbazole-NH and methoxy groups of different molecules. The crystal contains solvent molecules which are located in a channel parallel to the c axis. It was not possible to determine the position and nature of the solvent (a mixure of choroform, n-pentane and DMSO. The SQUEEZE [Spek (2015. Acta Cryst. C71, 9–18] option of PLATON was used to model the missing electron density. The given chemical formula and other crystal data do not take into account these solvent molecules.

  19. The Role of Porphyrin-Free-Base in the Electronic Structures and Related Properties of N-Fused Carbazole-Zinc Porphyrin Dye Sensitizers

    Directory of Open Access Journals (Sweden)

    Xing-Yu Li

    2015-11-01

    Full Text Available Dye sensitizers can significantly affect power conversion efficiency of dye-sensitized solar cells (DSSCs. Porphyrin-based dyes are promising sensitizers due to their performances in DSSCs. Here, based upon a N-fused carbazole-zinc porphyrin-free-base porphyrin triad containing an ethynyl-linkage (coded as DTBC, the novel porphyrin dyes named DTBC-MP and DTBC-TP were designed by varying the porphyrin-free-base units in the π conjugation of DTBC in order to study the effect of porphyrin-free-base in the modification of electronic structures and related properties. The calculated results indicate that, the extension of the conjugate bridge with the porphyrin-free-base unit results in elevation of the highest occupied molecular orbital (HOMO energies, decrease of the lowest unoccupied molecular orbital (LUMO energies, reduction of the HOMO-LUMO gap, red-shift of the absorption bands, and enhancement of the absorbance. The free energy changes demonstrate that introducing more porphyrin-free-base units in the conjugate bridge induces a faster rate of electron injection. The transition properties and molecular orbital characters suggest that the different transition properties might lead to a different electron injection mechanism. In terms of electronic structure, absorption spectra, light harvesting capability, and free energy changes, the designed DTBC-TP is a promising candidate dye sensitizer for DSSCs.

  20. The Tryptophan-Derived Endogenous Aryl Hydrocarbon Receptor Ligand 6-Formylindolo[3,2-b]Carbazole Is a Nanomolar UVA Photosensitizer in Epidermal Keratinocytes.

    Science.gov (United States)

    Park, Sophia L; Justiniano, Rebecca; Williams, Joshua D; Cabello, Christopher M; Qiao, Shuxi; Wondrak, Georg T

    2015-06-01

    Endogenous UVA chromophores may act as sensitizers of oxidative stress underlying cutaneous photoaging and photocarcinogenesis, but the molecular identity of non-DNA key chromophores displaying UVA-driven photodyamic activity in human skin remains largely undefined. Here we report that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct and endogenous high-affinity aryl hydrocarbon receptor (AhR) agonist, acts as a nanomolar photosensitizer potentiating UVA-induced oxidative stress irrespective of AhR ligand activity. In human HaCaT and primary epidermal keratinocytes, photodynamic induction of apoptosis was elicited by the combined action of solar-simulated UVA and FICZ, whereas exposure to the isolated action of UVA or FICZ did not impair viability. In a human epidermal tissue reconstruct, FICZ/UVA cotreatment caused pronounced phototoxicity inducing keratinocyte cell death, and FICZ photodynamic activity was also substantiated in a murine skin exposure model. Array analysis revealed pronounced potentiation of cellular heat shock, endoplasmic reticulum stress, and oxidative stress response gene expression observed only upon FICZ/UVA cotreatment. FICZ photosensitization caused intracellular oxidative stress, and comet analysis revealed introduction of formamidopyrimidine-DNA glycosylase (Fpg)-sensitive oxidative DNA lesions suppressible by antioxidant cotreatment. Taken together, our data demonstrate that the endogenous AhR ligand FICZ displays nanomolar photodynamic activity representing a molecular mechanism of UVA-induced photooxidative stress potentially operative in human skin.

  1. Solvatochromic effect in absorption and emission spectra of star-shaped bipolar derivatives of 1,3,5-triazine and carbazole. A time-dependent density functional study.

    Science.gov (United States)

    Baryshnikov, Gleb V; Bondarchuk, Sergey V; Minaeva, Valentina A; Ågren, Hans; Minaev, Boris F

    2017-02-01

    A series of three star-shaped compounds containing both donor (carbazole) and acceptor (2,4,6-triphenyl-1,3,5-triazine) moieties linked through various linking bridges was studied theoretically at the linear response TD-DFT level of theory to describe their absorption and fluorescence spectra. The concept of a localized charge-transfer excited state has been applied successfully to explain the observed strong solvatochromic effect in the emission spectra of the studied molecules, which can be utilized for the fabrication of color tunable solution-processable OLEDs. The concept is in particularly applicable to donor-acceptor species with a C 3 symmetry point group where the static dipole moment changes dramatically upon electronic excitation. An important peculiarity of the studied molecules is that they are characterized by non-zero values of the HOMO and LUMO orbitals in the same common part of molecular space that provides a large electric dipole transition moment for both light absorption and emission. Graphical abstract Star-shaped C 3 symmetry point group derivatives for color tunable OLEDs.

  2. Isolation and characterization of heavy polycyclic aromatic hydrocarbon-degrading bacteria adapted to electrokinetic conditions.

    Science.gov (United States)

    Li, Fengmei; Guo, Shuhai; Hartog, Niels; Yuan, Ye; Yang, Xuelian

    2016-02-01

    Polycyclic aromatic hydrocarbon (PAH)-degrading bacteria capable of growing under electrokinetic conditions were isolated using an adjusted acclimation and enrichment procedure based on soil contaminated with heavy PAHs in the presence of an electric field. Their ability to degrade heavy PAHs under an electric field was individually investigated in artificially contaminated soils. The results showed that strains PB4 (Pseudomonas fluorescens) and FB6 (Kocuria sp.) were the most efficient heavy PAH degraders under electrokinetic conditions. They were re-inoculated into a polluted soil from an industrial site with a PAH concentration of 184.95 mg kg(-1). Compared to the experiments without an electric field, the degradation capability of Pseudomonas fluorescens and Kocuria sp. was enhanced in the industrially polluted soil under electrokinetic conditions. The degradation extents of total PAHs were increased by 15.4 and 14.0% in the electrokinetic PB4 and FB6 experiments (PB4 + EK and FB6 + EK) relative to the PB4 and FB6 experiments without electrokinetic conditions (PB4 and FB6), respectively. These results indicated that P. fluorescens and Kocuria sp. could efficiently degrade heavy PAHs under electrokinetic conditions and have the potential to be used for the electro-bioremediation of PAH-contaminated soil, especially if the soil is contaminated with heavy PAHs.

  3. Isolation and Characterization of Microorganisms for Degradation of Minimal Oils and Fats at Low Temperatures

    Institute of Scientific and Technical Information of China (English)

    陈熹兮; 杨虹; 李道棠; 李堃宝

    2003-01-01

    The isolation of microorganisms for biodegradation of minimal fats and oils at low temperatures was reported. By using rapeseed oil as a sole carbon source, six strains were isolated from five kinds of oils/fats contaminated wastewater, soil, and active sludge. Among them, two strains which show the highest oil removal ratios were identified as Pseudomonas pseudoalcaligenes and Pseudomonas mendocina, respectively. The experiments of orthogonal impact conditions show that the optimal oil degradation condition is at pH 8.0, 5 C and 100 mg/L oil.Under this condition, the rapeseed oil degradation ratios of two strains after 24 hours amount to 92. 6% and 92.0% respectively, whereas the removal ratios of lard decrease to 39.5% and 54.3%.

  4. Biodegradation of the organophosphorus insecticide diazinon by Serratia sp. and Pseudomonas sp. and their use in bioremediation of contaminated soil.

    Science.gov (United States)

    Cycoń, Mariusz; Wójcik, Marcin; Piotrowska-Seget, Zofia

    2009-07-01

    An enrichment culture technique was used for the isolation of bacteria responsible for biodegradation of diazinon in soil. Three bacterial strains were screened and identified by MIDI-FAME profiling as Serratia liquefaciens, Serratia marcescens and Pseudomonas sp. All isolates were able to grow in mineral salt medium (MSM) supplemented with diazinon (50 mgL(-1)) as a sole carbon source, and within 14d 80-92% of the initial dose of insecticide was degraded by the isolates and their consortium. Degradation of diazinon was accelerated when MSM was supplemented with glucose. However, this process was linked with the decrease of pH values, after glucose utilization. Studies on biodegradation in sterilized soil showed that isolates and their consortium exhibited efficient degradation of insecticide (100mg kg(-1) soil) with a rate constant of 0.032-0.085d(-1), and DT(50) for diazinon was ranged from 11.5d to 24.5d. In contrast, degradation of insecticide in non-sterilized soil, non-supplemented earlier with diazinon, was characterized by a rate constant of 0.014d(-1) and the 7-d lag phase, during which only 2% of applied dose was degraded. The results suggested a strong correlation between microbial activity and chemical processes during diazinon degradation. Moreover, isolated bacterial strains may have potential for use in bioremediation of diazinon-contaminated soils.

  5. Management and treatment of contact lens-related Pseudomonas keratitis

    Directory of Open Access Journals (Sweden)

    Willcox MD

    2012-06-01

    Full Text Available Mark DP WillcoxSchool of Optometry and Vision Science, University of New South Wales, Sydney, AustraliaAbstract: Pubmed and Medline were searched for articles referring to Pseudomonas keratitis between the years 2007 and 2012 to obtain an overview of the current state of this disease. Keyword searches used the terms "Pseudomonas" + "Keratitis" limit to "2007–2012", and ["Ulcerative" or "Microbial"] + "Keratitis" + "Contact lenses" limit to "2007–2012". These articles were then reviewed for information on the percentage of microbial keratitis cases associated with contact lens wear, the frequency of Pseudomonas sp. as a causative agent of microbial keratitis around the world, the most common therapies to treat Pseudomonas keratitis, and the sensitivity of isolates of Pseudomonas to commonly prescribed antibiotics. The percentage of microbial keratitis associated with contact lens wear ranged from 0% in a study from Nepal to 54.5% from Japan. These differences may be due in part to different frequencies of contact lens wear. The frequency of Pseudomonas sp. as a causative agent of keratitis ranged from 1% in Japan to over 50% in studies from India, Malaysia, and Thailand. The most commonly reported agents used to treat Pseudomonas keratitis were either aminoglycoside (usually gentamicin fortified with a cephalosporin, or monotherapy with a fluoroquinolone (usually ciprofloxacin. In most geographical areas, most strains of Pseudomonas sp. (≥95% were sensitive to ciprofloxacin, but reports from India, Nigeria, and Thailand reported sensitivity to this antibiotic and similar fluoroquinolones of between 76% and 90%.Keywords: Pseudomonas, keratitis, contact lens

  6. Pseudomonas helmanticensis sp. nov., isolated from forest soil.

    Science.gov (United States)

    Ramírez-Bahena, Martha-Helena; Cuesta, Maria José; Flores-Félix, José David; Mulas, Rebeca; Rivas, Raúl; Castro-Pinto, Joao; Brañas, Javier; Mulas, Daniel; González-Andrés, Fernando; Velázquez, Encarna; Peix, Alvaro

    2014-07-01

    A bacterial strain, OHA11(T), was isolated during the course of a study of phosphate-solubilizing bacteria occurring in a forest soil from Salamanca, Spain. The 16S rRNA gene sequence of strain OHA11(T) shared 99.1% similarity with respect to Pseudomonas baetica a390(T), and 98.9% similarity with the type strains of Pseudomonas jessenii, Pseudomonas moorei, Pseudomonas umsongensis, Pseudomonas mohnii and Pseudomonas koreensis. The analysis of housekeeping genes rpoB, rpoD and gyrB confirmed its phylogenetic affiliation to the genus Pseudomonas and showed similarities lower than 95% in almost all cases with respect to the above species. Cells possessed two polar flagella. The respiratory quinone was Q9. The major fatty acids were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c/iso-C15 : 0 2-OH). The strain was oxidase-, catalase- and urease-positive, positive for arginine dihydrolase but negative for nitrate reduction, β-galactosidase production and aesculin hydrolysis. It was able to grow at 31 °C and at pH 11. The DNA G+C content was 58.1 mol%. DNA-DNA hybridization results showed values lower than 49% relatedness with respect to the type strains of the seven closest related species. Therefore, the combined genotypic, phenotypic and chemotaxonomic data support the classification of strain OHA11(T) to a novel species of the genus Pseudomonas, for which the name Pseudomonas helmanticensis sp. nov. is proposed. The type strain is OHA11(T) ( = LMG 28168(T) = CECT 8548(T)).

  7. NahY, a Catabolic Plasmid-Encoded Receptor Required for Chemotaxis of Pseudomonas putida to the Aromatic Hydrocarbon Naphthalene

    OpenAIRE

    1999-01-01

    Pseudomonas putida G7 exhibits chemotaxis to naphthalene, but the molecular basis for this was not known. A new gene, nahY, was found to be cotranscribed with meta cleavage pathway genes on the NAH7 catabolic plasmid for naphthalene degradation. The nahY gene encodes a 538-amino-acid protein with a membrane topology and a C-terminal region that resemble those of chemotaxis transducer proteins. A P. putida G7 nahY mutant grew on naphthalene but was not chemotactic to this aromatic hydrocarbon....

  8. Small Molecule Reversible Inhibitors of Bruton’s Tyrosine Kinase (BTK): Structure–Activity Relationships Leading to the Identification of 7-(2-Hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9 H -carbazole-1-carboxamide (BMS-935177)

    Energy Technology Data Exchange (ETDEWEB)

    De Lucca, George V.; Shi, Qing; Liu, Qingjie; Batt, Douglas G.; Beaudoin Bertrand, Myra; Rampulla, Rick; Mathur, Arvind; Discenza, Lorell; D’Arienzo, Celia; Dai, Jun; Obermeier, Mary; Vickery, Rodney; Zhang, Yingru; Yang, Zheng; Marathe, Punit; Tebben, Andrew J.; Muckelbauer, Jodi K.; Chang, ChiehYing J.; Zhang, Huiping; Gillooly, Kathleen; Taylor, Tracy; Pattoli, Mark A.; Skala, Stacey; Kukral, Daniel W.; McIntyre, Kim W.; Salter-Cid, Luisa; Fura, Aberra; Burke, James R.; Barrish, Joel C.; Carter, Percy H.; Tino, Joseph A.

    2016-09-08

    Bruton’s tyrosine kinase (BTK) belongs to the TEC family of nonreceptor tyrosine kinases and plays a critical role in multiple cell types responsible for numerous autoimmune diseases. This article will detail the structure–activity relationships (SARs) leading to a novel second generation series of potent and selective reversible carbazole inhibitors of BTK. With an excellent pharmacokinetic profile as well as demonstrated in vivo activity and an acceptable safety profile, 7-(2-hydroxypropan-2-yl)-4-[2-methyl-3-(4-oxo-3,4-dihydroquinazolin-3-yl)phenyl]-9H-carbazole-1-carboxamide 6 (BMS-935177) was selected to advance into clinical development.

  9. Functional bacterial amyloid increases Pseudomonas biofilm hydrophobicity and stiffness

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Vad, Brian Stougaard; Dueholm, Morten Simonsen

    2015-01-01

    The success of Pseudomonas species as opportunistic pathogens derives in great part from their ability to form stable biofilms that offer protection against chemical and mechanical attack. The extracellular matrix of biofilms contains numerous biomolecules, and it has recently been discovered...... that in Pseudomonas one of the components includes β-sheet rich amyloid fibrils (functional amyloid) produced by the fap operon. However, the role of the functional amyloid within the biofilm has not yet been investigated in detail. Here we investigate how the fap-based amyloid produced by Pseudomonas affects biofilm...

  10. Syntrophy in Methanogenic Degradation

    NARCIS (Netherlands)

    Worm, P.; Müller, N.; Plugge, C.M.; Stams, A.J.M.; Schink, B.

    2010-01-01

    This chapter deals with microbial communities of bacteria and archaea that closely cooperate in methanogenic degradation and perform metabolic functions in this community that neither one of them could carry out alone. The methanogenic degradation of fatty acids, alcohols, most aromatic compounds, a

  11. Rate of NDF degradation

    DEFF Research Database (Denmark)

    Weisbjerg, Martin Riis; Koukolová, V; Lund, Peter

    2007-01-01

    Degradation profiles for NDF were estimated for 83 samples of grass/grass-clover, 27 samples of cereal whole crop and 14 samples of maize whole crop.......Degradation profiles for NDF were estimated for 83 samples of grass/grass-clover, 27 samples of cereal whole crop and 14 samples of maize whole crop....

  12. Batteries: Imaging degradation

    Science.gov (United States)

    Shearing, Paul R.

    2016-11-01

    The degradation and failure of Li-ion batteries is strongly associated with electrode microstructure change upon (de)lithiation. Now, an operando X-ray tomography approach is shown to correlate changes in the microstructure of electrodes to cell performance, and thereby predict degradation pathways.

  13. Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria.

    Science.gov (United States)

    Zhu, Xuezhu; Ni, Xue; Waigi, Michael Gatheru; Liu, Juan; Sun, Kai; Gao, Yanzheng

    2016-08-09

    Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs) in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P₁ (Stenotrophomonas sp.) and P₃ (Pseudomonas sp.), which degraded more than 90% of phenanthrene (PHE) within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP), PHE, fluorene (FLR), pyrene (PYR), and benzo(a)pyrene (B(a)P) as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P₁ degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(a)P, and strain P₃ degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(a)P. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days). Compared with strain P₁, strain P₃ has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

  14. Biodegradation of Mixed PAHs by PAH-Degrading Endophytic Bacteria

    Directory of Open Access Journals (Sweden)

    Xuezhu Zhu

    2016-08-01

    Full Text Available Endophytic bacteria can promote plant growth, induce plant defence mechanisms, and increase plant resistance to organic contaminants. The aims of the present study were to isolate highly PAH-degrading endophytic bacteria from plants growing at PAH-contaminated sites and to evaluate the capabilities of these bacteria to degrade polycyclic aromatic hydrocarbons (PAHs in vitro, which will be beneficial for re-colonizing target plants and reducing plant PAH residues through the inoculation of plants with endophytic bacteria. Two endophytic bacterial strains P1 (Stenotrophomonas sp. and P3 (Pseudomonas sp., which degraded more than 90% of phenanthrene (PHE within 7 days, were isolated from Conyza canadensis and Trifolium pretense L., respectively. Both strains could use naphthalene (NAP, PHE, fluorene (FLR, pyrene (PYR, and benzo(apyrene (B(aP as the sole sources of carbon and energy. Moreover, these bacteria reduced the contamination of mixed PAHs at high levels after inoculation for 7 days; strain P1 degraded 98.0% NAP, 83.1% FLR, 87.8% PHE, 14.4% PYR, and 1.6% B(aP, and strain P3 degraded 95.3% NAP, 87.9% FLR, 90.4% PHE, 6.9% PYR, and negligible B(aP. Notably, the biodegradation of PAHs could be promoted through additional carbon and nitrogen nutrients; therein, beef extract was suggested as the optimal co-substrate for the degradation of PAHs by these two strains (99.1% PHE was degraded within 7 days. Compared with strain P1, strain P3 has more potential for the use in the removal of PAHs from plant tissues. These results provide a novel perspective in the reduction of plant PAH residues in PAH-contaminated sites through inoculating plants with highly PAH-degrading endophytic bacteria.

  15. Microbial community degradation of widely used quaternary ammonium disinfectants.

    Science.gov (United States)

    Oh, Seungdae; Kurt, Zohre; Tsementzi, Despina; Weigand, Michael R; Kim, Minjae; Hatt, Janet K; Tandukar, Madan; Pavlostathis, Spyros G; Spain, Jim C; Konstantinidis, Konstantinos T

    2014-10-01

    Benzalkonium chlorides (BACs) are disinfectants widely used in a variety of clinical and environmental settings to prevent microbial infections, and they are frequently detected in nontarget environments, such as aquatic and engineered biological systems, even at toxic levels. Therefore, microbial degradation of BACs has important ramifications for alleviating disinfectant toxicity in nontarget environments as well as compromising disinfectant efficacy in target environments. However, how natural microbial communities respond to BAC exposure and what genes underlie BAC biodegradation remain elusive. Our previous metagenomic analysis of a river sediment microbial community revealed that BAC exposure selected for a low-diversity community, dominated by several members of the Pseudomonas genus that quickly degraded BACs. To elucidate the genetic determinants of BAC degradation, we conducted time-series metatranscriptomic analysis of this microbial community during a complete feeding cycle with BACs as the sole carbon and energy source under aerobic conditions. Metatranscriptomic profiles revealed a candidate gene for BAC dealkylation, the first step in BAC biodegradation that results in a product 500 times less toxic. Subsequent biochemical assays and isolate characterization verified that the putative amine oxidase gene product was functionally capable of initiating BAC degradation. Our analysis also revealed cooperative interactions among community members to alleviate BAC toxicity, such as the further degradation of BAC dealkylation by-products by organisms not encoding amine oxidase. Collectively, our results advance the understanding of BAC aerobic biodegradation and provide genetic biomarkers to assess the critical first step of this process in nontarget environments.

  16. Occurrence of Pseudomonas aeruginosa in Kuwait soil.

    Science.gov (United States)

    Al-Saleh, Esmaeil; Akbar, Abrar

    2015-02-01

    Environmentally ubiquitous bacteria such as Pseudomonas aeruginosa evolved mechanisms to adapt and prevail under diverse conditions. In the current investigation, strains of P. aeruginosa demonstrating high rates of crude oil utilization and tolerance to high concentrations of heavy metals were found in both crude oil-contaminated and uncontaminated sites in Kuwait, and were dominant in the contaminated sites. The incidence of P. aeruginosa in tested soils implies the definitive pattern of crude oil contamination in the selection of the bacterial population in petroleum-contaminated sites in Kuwait. Surprisingly, the unculturable P. aeruginosa in different soil samples showed significant high similarity coefficients based on 16S-RFLP analyses, implying that the unculturable fraction of existing bacterial population in environmental samples is more stable and, hence, reliable for phylogenetic studies compared to the culturable bacteria.

  17. Osmoregulation in Pseudomonas aeruginosa under hyperosmotic shock.

    Science.gov (United States)

    Velasco, R; Burgoa, R; Flores, E; Hernández, E; Villa, A; Vaca, S

    1995-01-01

    Pseudomonas aeruginosa PAO1 strain was found to be able to tolerate 700 mM NaCl. 0.5 mM of the osmoprotectant betaine restablished the growth of this strain in 1200 mM NaCl. Intracellular K+ and glutamate concentrations of P. aeruginosa PAO1 after an hyperosmotic shock (400 mM NaCl) showed a permanent increase. Adition of betaine (0.5 mM) to the medium with NaCl had an inhibitory effect on the intracellular accumulation of glutamate. The results indicate that P. aeruginosa PAO1 resists high NaCl concentrations, K+ accumulation and glutamate synthesis probably being the first mechanisms involved in adaptation to osmotic stress. Also is is demonstrated that betaine modulates intracellular glutamate levels in osmotically stressed P. aeruginosa PAO1.

  18. Pseudomonas aeruginosa endophthalmitis masquerading as chronic uveitis

    Directory of Open Access Journals (Sweden)

    Kalpana Badami Nagaraj

    2013-01-01

    Full Text Available A 65-year-old male presented with decreased vision in the left eye of 15-day duration after having undergone an uneventful cataract surgery 10 months back. He had been previously treated with systemic steroids for recurrent uveitis postoperatively on three occasions in the same eye. B-scan ultrasonography showed multiple clumplike echoes suggestive of vitreous inflammation. Aqueous tap revealed Pseudomonas aeruginosa sensitive to ciprofloxacin. The patient was treated with intravitreal ciprofloxacin and vancomycin along with systemic ciprofloxacin with good clinical response. Even a virulent organism such as P.aeruginosa can present as a chronic uveitis, which, if missed, can lead to a delay in accurate diagnosis and appropriate management.

  19. Glycopeptide dendrimers as Pseudomonas aeruginosa biofilm inhibitors.

    Science.gov (United States)

    Reymond, Jean-Louis; Bergmann, Myriam; Darbre, Tamis

    2013-06-01

    Synthetic glycopeptide dendrimers composed of a branched oligopeptide tree structure appended with glycosidic groups at its multiple N-termini were investigated for binding to the Pseudomonas aeruginosa lectins LecB and LecA. These lectins are partly responsible for the formation of antibiotic resistant biofilms in the human pathogenic bacterium P. aeruginosa, which causes lethal airway infections in immune-compromised and cystic fibrosis patients. Glycopeptide dendrimers with high affinity to the lectins were identified by screening of combinatorial libraries. Several of these dendrimers, in particular the LecB specific glycopeptide dendrimers FD2 and D-FD2 and the LecA specific glycopeptide dendrimers GalAG2 and GalBG2, also efficiently block P. aeruginosa biofilm formation and induce biofilm dispersal in vitro. Structure-activity relationship and structural studies are reviewed, in particular the observation that multivalency is essential to the anti-biofilm effect in these dendrimers.

  20. Pseudomonas aeruginosa biofilms in cystic fibrosis

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Bjarnsholt, Thomas

    2010-01-01

    The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein...... and DNA. In CF lungs, the polysaccharide alginate is the major part of the P. aeruginosa biofilm matrix. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and resist phagocytosis, as well as other components of the innate and the adaptive immune system....... As a consequence, a pronounced antibody response develops, leading to immune complex-mediated chronic inflammation, dominated by polymorphonuclear leukocytes. The chronic inflammation is the major cause of the lung tissue damage in CF. Biofilm growth in CF lungs is associated with an increased frequency...

  1. Complement activation by Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, E T; Kharazmi, A; Garred, P

    1993-01-01

    In chronic infections, such as the bronchopulmonary Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients, bacteria persist despite an intact host immune defense and frequent antibiotic treatment. An important reason for the persistence of the bacteria is their capacity for the biofilm...... immuno-electrophoresis, C5a generation tested by a PMN chemotactic assay, and terminal complement complex formation measured by ELISA. Two of the four assays showed that P. aeruginosa grown in biofilm activated complement less than planktonic bacteria, and all assays showed that activation by intact...... influx of neutrophils are known to cause inflammatory changes in the lungs. P. aeruginosa persisting in biofilms may contribute to the constant inflammation taking place in the lungs of CF patients....

  2. The immune system vs. Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jensen, Peter Østrup; Givskov, Michael; Bjarnsholt, Thomas

    2010-01-01

    revealed both innate as well as adaptive immune responses to biofilms. On the other hand, measures launched by biofilm bacteria to achieve protection against the various immune responses have also been demonstrated. Whether particular immune responses to biofilm infections exist remains to be firmly...... established. However, because biofilm infections are often persistent (or chronic), an odd situation appears with the simultaneous activation of both arms of the host immune response, neither of which can eliminate the biofilm pathogen, but instead, in synergy, causes collateral tissue damage. Although...... the present review on the immune system vs. biofilm bacteria is focused on Pseudomonas aeruginosa (mainly because this is the most thoroughly studied), many of the same mechanisms are also seen with biofilm infections generated by other microorganisms....

  3. Stratified growth in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Werner, E.; Roe, F.; Bugnicourt, A.;

    2004-01-01

    In this study, stratified patterns of protein synthesis and growth were demonstrated in Pseudomonas aeruginosa biofilms. Spatial patterns of protein synthetic activity inside biofilms were characterized by the use of two green fluorescent protein (GFP) reporter gene constructs. One construct...... carried an isopropyl-beta-D-thiogalactopyranoside (IPTG)-inducible gfpmut2 gene encoding a stable GFP. The second construct carried a GFP derivative, gfp-AGA, encoding an unstable GFP under the control of the growth-rate-dependent rrnBp(1) promoter. Both GFP reporters indicated that active protein...... of oxygen limitation in the biofilm. Oxygen microelectrode measurements showed that oxygen only penetrated approximately 50 mum into the biofilm. P. aeruginosa was incapable of anaerobic growth in the medium used for this investigation. These results show that while mature P. aeruginosa biofilms contain...

  4. Rhamnolipid Biosurfactants Produced by Pseudomonas Species

    Directory of Open Access Journals (Sweden)

    Banu Kaskatepe

    Full Text Available ABSTRACT: Surfactants are chemical products widely used in our daily life in toothpaste and other personal hygiene and cosmetic products, and in several industries. Biosurfactants are surfactants of biological origin that can be produced by microorganisms and have many advantages, such as low toxicity and high biodegradability, compared to synthetic counterparts. Unfortunately, high production costs limit the use of biosurfactants. Low-cost production is the most important factor for biosurfactants to be able to compete in the global market place. This review presents general information on rhamnolipid biosurfactant produced by Pseudomonas species, as well as on their production and applications. In addition, industrial products and their wastes used for rhamnolipid production are reviewed in detail based on recent studies.

  5. Phospholipids and protein adaptation of Pseudomonas sp. to the xenoestrogen tributyltin chloride (TBT).

    Science.gov (United States)

    Bernat, Przemysław; Siewiera, Paulina; Soboń, Adrian; Długoński, Jerzy

    2014-09-01

    A tributyltin (TBT)-resistant strain of Pseudomonas sp. isolated from an overworked car filter was tested for its adaptation to TBT. The isolate was checked for organotin degradation ability, as well as membrane lipid and cellular protein composition in the presence of TBT. The phospholipid profiles of bacteria, grown with and without increased amounts of TBT, were characterized using liquid chromatography/electrospray ionization/mass spectrometry. The strain reacted to the biocide by changing the composition of its phospholipids. TBT induced a twofold decline in the amounts of many molecular species of phosphatidylglycerol and an increase in the levels of phosphatidic acid (by 58%) and phosphatidylethanolamine (by 70%). An increase in the degree of saturation of phospholipid fatty acids of TBT exposed Pseudomonas sp. was observed. These changes in the phospholipid composition and concentration reflect the mechanisms which support optimal lipid ordering in the presence of toxic xenobiotic. In the presence of TBT the abundances of 16 proteins, including TonB-dependent receptors, porins and peroxidases were modified, which could indicate a contribution of some enzymes to TBT resistance.

  6. Decolorization and detoxification of Congo red and textile industry effluent by an isolated bacterium Pseudomonas sp. SU-EBT.

    Science.gov (United States)

    Telke, Amar A; Joshi, Swati M; Jadhav, Sheetal U; Tamboli, Dhawal P; Govindwar, Sanjay P

    2010-04-01

    The 16S rRNA sequence and biochemical characteristics revealed the isolated organism as Pseudomonas sp. SU-EBT. This strain showed 97 and 90% decolorization of a recalcitrant dye, Congo red (100 mg l(-1)) and textile industry effluent with 50% reduction in COD within 12 and 60 h, respectively. The optimum pH and temperature for the decolorization was 8.0 and 40 degrees C, respectively. Pseudomonas sp. SU-EBT was found to tolerate the dye concentration up to 1.0 g l(-1). Significant induction in the activity of intracellular laccase suggested its involvement in the decolorization of Congo red. The metabolites formed after decolorization of Congo red, such as p-dihydroxy biphenyl, 8-amino naphthol 3-sulfonic acid and 3-hydroperoxy 8-nitrosonaphthol were characterized using FTIR and GC-MS. Phytotoxicity study revealed nontoxic nature of the degradation metabolites to Sorghum bicolor, Vigna radiata, Lens culinaris and Oryza sativa plants as compared to Congo red and textile industry effluent. Pseudomonas sp. SU-EBT decolorized several individual textile dyes, dye mixtures and textile industry effluent, thus it is a useful strain for the development of effluent treatment methods in textile processing industries.

  7. Differential infectivity of two Pseudomonas species and the immune response in the milkweed bug, Oncopeltus fasciatus (Insecta: Hemiptera).

    Science.gov (United States)

    Schneider, M; Dorn, A

    2001-10-01

    Pseudomonas aeruginosa and Pseudomonas putida show a profound differential infectivity after inoculation in Oncopeltus fasciatus. Whereas P. putida has no significant impact on nymphs, P. aeruginosa kills all experimental animals within 48 h. Both Pseudomonas species, however, induce the same four hemolymph peptides in O. fasciatus. Also injection of saline solution and injury induced these peptides. In general peptide induction was stronger in nymphs than in adult males. A significantly higher number of nymphs survived a challenge with P. aeruginosa when an immunization with P. putida preceded. The antibacterial properties of the hemolymph were demonstrated in inhibition experiments with P. putida. Two of the four inducible peptides (peptides 1 and 4) could be partially sequenced after Edman degradation and were compared with known antibacterial peptides. Peptide 1, of 15 kDa, showed 47.1% identity with the glycine-rich hemiptericin of Pyrrhocoris apterus. Peptide 4, of 2 kDa, had a 77.8% identity with the proline-rich pyrrhocoricin of P. apterus and a 76.9% identity with metalnikowin 1 of Palomena prasina. Peptides 2 and 3 are also small, with molecular weights of 8 and 5 kDa.

  8. Genetic characterization of caffeine degradation by bacteria and its potential applications.

    Science.gov (United States)

    Summers, Ryan M; Mohanty, Sujit K; Gopishetty, Sridhar; Subramanian, Mani

    2015-05-01

    The ability of bacteria to grow on caffeine as sole carbon and nitrogen source has been known for over 40 years. Extensive research into this subject has revealed two distinct pathways, N-demethylation and C-8 oxidation, for bacterial caffeine degradation. However, the enzymological and genetic basis for bacterial caffeine degradation has only recently been discovered. This review article discusses the recent discoveries of the genes responsible for both N-demethylation and C-8 oxidation. All of the genes for the N-demethylation pathway, encoding enzymes in the Rieske oxygenase family, reside on 13.2-kb genomic DNA fragment found in Pseudomonas putida CBB5. A nearly identical DNA fragment, with homologous genes in similar orientation, is found in Pseudomonas sp. CES. Similarly, genes for C-8 oxidation of caffeine have been located on a 25.2-kb genomic DNA fragment of Pseudomonas sp. CBB1. The C-8 oxidation genes encode enzymes similar to those found in the uric acid metabolic pathway of Klebsiella pneumoniae. Various biotechnological applications of these genes responsible for bacterial caffeine degradation, including bio-decaffeination, remediation of caffeine-contaminated environments, production of chemical and fuels and development of diagnostic tests have also been demonstrated.

  9. Simultaneous growth on citrate reduces the effects of iron limitation during toluene degradation in Pseudomonas

    NARCIS (Netherlands)

    Dinkla, IJT; Janssen, DB

    2003-01-01

    Rhizoremediation has been suggested as an attractive bioremediation strategy for the effective breakdown of pollutants in soil. The presence of plant root exudates such as organic acids, sugars, and amino acids that may serve as carbon sources or biosynthetic building blocks and the limited bioavail

  10. Aerobic degradation of highly chlorinated polychlorobiphenyls by a marine bacterium, Pseudomonas CH07

    Digital Repository Service at National Institute of Oceanography (India)

    De, J.; Ramaiah, N.; Sarkar, A.

    : jaysankarde@yahoo.com. Introduction Polychlorinated biphenyls (PCBs) are a class of compounds where the aromatic biphenyl rings carry one to ten chlorine atoms and, theoretically, 209 different PCB congeners can thus be produced. Due to their non... are the ultimate global sinks for worldwide accumulations of PCBs (Berkaw et al., 1996). The toxicity of different congeners of PCBs varies according to the chlorine substitution at different positions of the biphenyl ring and the physical effects of PCBs vary...

  11. Introduction of Atrazine-Degrading Pseudomonas SP. Strain ADP to Enhance Phytoremediation of Atrazine

    Science.gov (United States)

    Atrazine (ATR) has been widely applied in the US Midwestern states. Public health and ecological concerns have been raised about contamination of surface and ground water by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects. Phytoremediati...

  12. Focused ion beam and field-emission microscopy of metallic filaments in memory devices based on thin films of an ambipolar organic compound consisting of oxadiazole, carbazole, and fluorene units

    Science.gov (United States)

    Pearson, Christopher; Bowen, Leon; Lee, Myung Won; Fisher, Alison L.; Linton, Katherine E.; Bryce, Martin R.; Petty, Michael C.

    2013-01-01

    We report on the mechanism of operation of organic thin film resistive memory architectures based on an ambipolar compound consisting of oxadiazole, carbazole, and fluorene units. Cross-sections of the devices have been imaged by electron microscopy both before and after applying a voltage. The micrographs reveal the growth of filaments, with diameters of 50 nm–100 nm, on the metal cathode. We suggest that these are formed by the drift of aluminium ions from the anode and are responsible for the observed switching and negative differential resistance phenomena in the memory devices.

  13. Incorporating two different chromophores onto a silicon atom: the crystal structure and photophysical properties of 9-{4-[(9,9-dimethyl-9H-fluoren-2-yl)dimethylsilyl]phenyl}-9H-carbazole.

    Science.gov (United States)

    Lee, Ah-Rang; Han, Won-Sik

    2015-03-01

    The crystal structure of the title bifunctional silicon-bridged compound, C(35)H(31)NSi, (I), has been determined. The compound crystallizes in the centrosymmetric space group P2(1)/c. In the crystal structure, the pairs of aryl rings in the two different chromophores, i.e. 9-phenyl-9H-carbazole and 9,9-dimethyl-9H-fluorene, are positioned orthogonally. In the crystal packing, no classical hydrogen bonding is observed. UV-Vis absorption and fluorescence emission spectra show that the central Si atom successfully breaks the electronic conjugation between the two different chromophores, and this was further analysed by density functional theory (DFT) calculations.

  14. The crystal structure of Pseudomonas putida azoreductase - the active site revisited.

    Science.gov (United States)

    Gonçalves, Ana Maria D; Mendes, Sónia; de Sanctis, Daniele; Martins, Lígia O; Bento, Isabel

    2013-12-01

    The enzymatic degradation of azo dyes begins with the reduction of the azo bond. In this article, we report the crystal structures of the native azoreductase from Pseudomonas putida MET94 (PpAzoR) (1.60 Å), of PpAzoR in complex with anthraquinone-2-sulfonate (1.50 Å), and of PpAzoR in complex with Reactive Black 5 dye (1.90 Å). These structures reveal the residues and subtle changes that accompany substrate binding and release. Such changes highlight the fine control of access to the catalytic site that is required by the ping-pong mechanism, and in turn the specificity offered by the enzyme towards different substrates. The topology surrounding the active site shows novel features of substrate recognition and binding that help to explain and differentiate the substrate specificity observed among different bacterial azoreductases.

  15. Bioremediation of Petroleum hydrocarbon by using Pseudomonas species isolated from Petroleum contaminated soil

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2014-12-01

    Full Text Available A newly isolated strain Pseudomonas fluorescens (Accession number KF 279042.1 have potential in diesel degradation and can be recommended for bioremediation of sites that are contaminated with diesel. This bacterium was characterized on the basis of microbiological, biochemical and molecular analysis. Bacterial growth optimization was studied based on carbon source, nitrogen source, pH and temperature. The strain was selected based on its ability to show growth in medium containing diesel. In addition, optimum temperature and pH for increased growth by the isolate were found to be 37oC and pH 8.0 indicating the maximum utilization of diesel. At the same time, production of protease and urease enzymes during the utilization of diesel was also assayed following the standard procedures.

  16. Effect of cimetidine on catalase activity of Pseudomonas aeruginosa: a suggested mechanism of action.

    Science.gov (United States)

    Masoud, Masoudeh; Ebrahimi, Farnoosh; Minai-Tehrani, Dariush

    2014-01-01

    Catalase is an important enzyme for the degradation of hydrogen peroxide in cells. Bacteria have potent catalase to deal with H2O2 in their medium culture. Any chemicals that inhibit catalase activity can be harmful for cells. Histamine H2 antagonist drugs such as cimetidine and ranitidine are used for the treatment of gastrointestinal tract disorders. The present results showed that cimetidine could inhibit the catalase activity of Pseudomonas aeruginosa in a competitive inhibition. The determination of IC50 value and Ki (6.5 μM) of cimetidine demonstrated that the enzyme binds to the drug with high affinity. Binding of the drug to the enzyme was pH-dependent and no binding was observed at basic pH (>9) and acidic pH (catalase activity.

  17. Structure of the O polysaccharide and serological classification of Pseudomonas syringae pv. ribicola NCPPB 1010.

    Science.gov (United States)

    Ovod, V V; Zdorovenko, E L; Shashkov, A S; Kocharova, N A; Knirel, Y A

    2000-04-01

    The O polysaccharide (OPS) moiety of the lipopolysaccharide (LPS) of a phytopathogenic bacterium Pseudomonas syringae pv. ribicola NCPPB 1010 was studied by sugar and methylation analyses, Smith degradation, and 1H- and 13C-NMR spectroscopy, including 2D COSY, TOCSY, NOESY and H-detected 1H,13C HMQC experiments. The OPS structure was elucidated, and shown to be composed of branched pentasaccharide repeating units (O repeats) of two types, major (1) and minor (2), differing in the position of substitution of one of the rhamnose residues. Both O repeats form structurally homogeneous blocks within the same polysaccharide molecule. Although P. syringae pv. ribicola NCPPB 1010 demonstrates genetic relatedness and similarity in the OPS chemical structure to some other P. syringae pathovars, it did not cross-react with any OPS-specific mAbs produced against heterologous P. syringae strains. Therefore, we propose to classify P. syringae pv. ribicola NCPPB 1010 in a new serogroup, O8.

  18. New strategies for genetic engineering Pseudomonas syringae using recombination

    Science.gov (United States)

    Here we report that DNA oligonucleotides (oligos) introduced directly into bacteria by electroporation can recombine with the bacterial chromosome. This phenomenon was identified in Pseudomonas syringae and we subsequently found that Escherichia coli, Salmonella typhimurium and Shigella flexneri are...

  19. The Enzymes of the Ammonia Assimilation in Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, Dick B.; Camp, Huub J.M. op den; Leenen, Pieter J.M.; Drift, Chris van der

    1980-01-01

    Glutamine synthetase from Pseudomonas aeruginosa is regulated by repression/derepression of enzyme synthesis and by adenylylation/deadenylylation control. High levels of deadenylylated biosynthetically active glutamine synthetase were observed in cultures growing with limiting amounts of nitrogen wh

  20. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis

    DEFF Research Database (Denmark)

    Johansen, Helle Krogh; Gøtzsche, Peter C

    2015-01-01

    BACKGROUND: Chronic pulmonary infection in cystic fibrosis results in progressive lung damage. Once colonisation of the lungs with Pseudomonas aeruginosa occurs, it is almost impossible to eradicate. Vaccines, aimed at reducing infection with Pseudomonas aeruginosa, have been developed...... in the vaccine group and 91 (1 severe) in the control group. In this large trial of a vaccine developed against flagella antigens, antibody titres against the epitopes contained in the vaccine were higher in the vaccine group compared to the placebo group (P Vaccines against....... This is an update of a previously published review. OBJECTIVES: To assess the effectiveness of vaccination against Pseudomonas aeruginosa in cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register using the terms vaccines AND pseudomonas (last search 30...