WorldWideScience

Sample records for carbazole degrader pseudomonas

  1. 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.

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Effects of carbazole-degradative plasmid pCAR1 on biofilm morphology in Pseudomonas putida KT2440.

    Science.gov (United States)

    Lee, Seunguk; Takahashi, Yurika; Oura, Hiromu; Suzuki-Minakuchi, Chiho; Okada, Kazunori; Yamane, Hisakazu; Nomura, Nobuhiko; Nojiri, Hideaki

    2016-04-01

    Bacteria typically form biofilms under natural conditions. To elucidate the effect of the carriage of carbazole-degradative plasmid pCAR1 on biofilm formation by host bacteria, we compared the biofilm morphology, using confocal laser scanning microscopy, of three pCAR1-free and pCAR1-carrying Pseudomonas hosts: P. putida KT2440, P. aeruginosa PAO1 and P. fluorescens Pf0-1. Although pCAR1 did not significantly affect biofilm formation by PAO1 or Pf0-1, pCAR1-carrying KT2440 became filamentous and formed flat biofilms, whereas pCAR1-free KT2440 formed mushroom-like biofilms. pCAR1 contains three genes encoding nucleoid-associated proteins (NAPs), namely, Pmr, Pnd and Phu. The enhanced filamentous morphology was observed in two double mutants [KT2440(pCAR1ΔpmrΔpnd) and KT2440(pCAR1ΔpmrΔphu)], suggesting that these NAPs are involved in modulating the filamentous phenotype. Transcriptome analyses of the double mutants identified 32 candidate genes that may be involved in filamentation of KT2440. Overexpression of PP_2193 in KT2440 induced filamentation and overexpression of PP_0308 or PP_0309 in KT2440(pCAR1) enhanced filamentation of cells over time. This suggests that pCAR1 induces development of an abnormal filamentous morphology by KT2440 via a process involving overexpression of several genes, such as PP_2193. In addition, pCAR1-encoded NAPs partly suppress too much filamentation of KT2440(pCAR1) by repressing transcription of some genes, such as PP_0308 and PP_0309. PMID:26743211

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

    Science.gov (United States)

    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

    Directory of Open Access Journals (Sweden)

    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.

    Science.gov (United States)

    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. Methylmercury degradation by Pseudomonas putida V1.

    Science.gov (United States)

    Cabral, Lucélia; Yu, Ri-Qing; Crane, Sharron; Giovanella, Patricia; Barkay, Tamar; Camargo, Flávio A O

    2016-08-01

    Environmental contamination of mercury (Hg) has caused public health concerns with focuses on the neurotoxic substance methylmercury, due to its bioaccumulation and biomagnification in food chains. The goals of the present study were to examine: (i) the transformation of methylmercury, thimerosal, phenylmercuric acetate and mercuric chloride by cultures of Pseudomonas putida V1, (ii) the presence of the genes merA and merB in P. putida V1, and (iii) the degradation pathways of methylmercury by P. putida V1. Strain V1 cultures readily degraded methylmercury, thimerosal, phenylmercury acetate, and reduced mercuric chloride into gaseous Hg(0). However, the Hg transformation in LB broth by P. putida V1 was influenced by the type of Hg compounds. The merA gene was detected in P. putida V1, on the other hand, the merB gene was not detected. The sequencing of this gene, showed high similarity (100%) to the mercuric reductase gene of other Pseudomonas spp. Furthermore, tests using radioactive (14)C-methylmercury indicated an uncommon release of (14)CO2 concomitant with the production of Hg(0). The results of the present work suggest that P. putida V1 has the potential to remove methylmercury from contaminated sites. More studies are warranted to determine the mechanism of removal of methylmercury by P. putida V1. PMID:27062344

  8. Degradation of polynuclear aromatic hydrocarbons by two strains of Pseudomonas.

    Science.gov (United States)

    Nwinyi, Obinna C; Ajayi, Oluseyi O; Amund, Olukayode O

    2016-01-01

    The goal of this investigation was to isolate competent polynuclear aromatic hydrocarbons degraders that can utilize polynuclear aromatic hydrocarbons of former industrial sites at McDoel Switchyard in Bloomington, Indiana. Using conventional enrichment method based on soil slurry, we isolated, screened and purified two bacterial species strains PB1 and PB2. Applying the ribotyping technique using the 16S rRNA gene analysis, the strains were assigned to the genus Pseudomonas (Pseudomonas plecoglossicida strain PB1 and Pseudomonas sp. PB2). Both isolates showed promising metabolic capacity on pyrene sprayed MS agar plates during the preliminary investigations. Using time course studies in the liquid cultures at calculated concentrations 123, 64, 97 and 94ppm for naphthalene, chrysene, fluroanthene and pyrene, P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 showed partial utilization of the polynuclear aromatic hydrocarbons. Naphthalene was degraded between 26% and 40%, chrysene 14% and 16%, fluroanthene 5% and 7%; pyrene 8% and 13% by P. plecoglossicida strain PB1 and Pseudomonas sp. PB2 respectively. Based on their growth profile, we developed a model R(2)=1 to predict the degradation rate of slow polynuclear aromatic hydrocarbon-degraders where all the necessary parameters are constant. From this investigation, we confirm that the former industrial site soil microbial communities may be explored for the biorestoration of the industrial site. PMID:27245129

  9. 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.

  10. Variability in Pseudomonas aeruginosa Lipopolysaccharide Expression during Crude Oil Degradation

    OpenAIRE

    Norman, R. Sean; Frontera-Suau, Roberto; Morris, Pamela J.

    2002-01-01

    Bacterial utilization of crude oil components, such as the n-alkanes, requires complex cell surface adaptation to allow adherence to oil. To better understand microbial cell surface adaptation to growth on crude oil, the cell surface characteristics of two Pseudomonas aeruginosa strains, U1 and U3, both isolated from the same crude oil-degrading microbial community enriched on Bonny Light crude oil (BLC), were compared. Analysis of growth rates demonstrated an increased lag time for U1 cells ...

  11. Aflatoxin B1 Degradation by a Pseudomonas Strain

    Science.gov (United States)

    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

  12. Addition of Aromatic Substrates Restores Trichloroethylene Degradation Activity in Pseudomonas putida F1

    OpenAIRE

    Morono, Yuki; Unno, Hajime; TANJI, Yasunori; Hori, Katsutoshi

    2004-01-01

    The rate of trichloroethylene (TCE) degradation by toluene dioxygenase (TDO) in resting cells of Pseudomonas putida F1 gradually decreased and eventually stopped within 1.5 h, as in previous reports. However, the subsequent addition of toluene, which is the principal substrate of TDO, resulted in its immediate degradation without a lag phase. After the consumption of toluene, degradation of TCE restarted at a rate similar to its initial degradation, suggesting that this degradation was mediat...

  13. Mono-chlorophenol degradation by pseudomonas putida CP1 and a mixed microbial population

    OpenAIRE

    Farrell, Alan

    2000-01-01

    A commercial mixed culture, Biolyte HAB, degraded mono-chlorophenols using a metci- cleavage pathway. 2- and 3-chlorophenol degradation was incomplete, leading to the accumulation of dead-end metabolites. Biolyte HAB was capable of the complete degradation of 2.34 mM 4-chlorophenol, via the intermediate 5-chloro-2- hydroxymuconic semialdehyde, using the meta- cleavage pathway. Pseudomonas putida CPI degraded mono-chlorophenols to completion via an orthocleavage pathway. The ability of P. ...

  14. Phenol and trichloroethylene degradation by Pseudomonas cepacia G4: kinetics and interactions between substrates.

    OpenAIRE

    Folsom, B R; Chapman, P J; Pritchard, P H

    1990-01-01

    Intact cells of Pseudomonas cepacia G4 completely degraded trichloroethylene (TCE) following growth with phenol. Degradation kinetics were determined for both phenol, used to induce requisite enzymes, and TCE, the target substrate. Apparent Ks and Vmax values for degradation of phenol by cells were 8.5 microM and 466 nmol/min per mg of protein, respectively. At phenol concentrations greater than 50 microM, phenol degradation was inhibited, yielding an apparent second-order inhibitory value, K...

  15. 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.

    and the other coplanar tetrachloro congener CB-77 was degraded by more than 40% within 40 hours by this microorganism. Apparently absence of bphC in this bacterium led to proposition of different mechanism of PCBs degradation. KEY WORDS: Pseudomonas CH07...

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

    Science.gov (United States)

    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. 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

  18. 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

  19. Chemotaxis to furan compounds by furan-degrading Pseudomonas strains

    Science.gov (United States)

    Two Pseudomonas strains known to utilize furan derivatives were shown to be attracted to furfural, 5-hydroxymethylfurfural, furfuryl alcohol, and 2-furoic acid in the absence of furan metabolism. In addition, a LysR-family regulatory protein known to regulate furan metabolic genes was found to be i...

  20. Kinetics of cometabolic degradation of 2-chlorophenol and phenol by Pseudomonas putida

    Institute of Scientific and Technical Information of China (English)

    Xing-ping LIU

    2009-01-01

    In order to address the complex cometabolic degradation of toxic compounds,batch experiments on the biodegradation of 2-chlorophenol (2-CP) and phenol by Pseudomonas putida were carried out.The experimental results show that 2-CP has an inhibitory effect on cell growth and phenol degradation,which demonstrates that the interaction between substrates affects cell growth and substrate degradation.A kinetic model of cell growth and substrate transformation was also developed.The square of the correlation coefficient from the experiment was 0.97,indicating that this model properly simulates the cometabolic degradation of 2-CP and phenol.

  1. Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA

    NARCIS (Netherlands)

    Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

    2014-01-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacteri

  2. Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

    NARCIS (Netherlands)

    Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M.F; Van der Ent, S.; Van Strijp, J.A.G.

    2014-01-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacteri

  3. Catabolite repression and nitrogen control of allantoin-degrading enzymes in Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Janssen, D.B.; Drift, C. van der

    1983-01-01

    The formation of the allantoin-degrading enzymes allantoinase, allantoicase and ureidoglycolase in Pseudomonas aeruginosa was found to be regulated by induction, catabolite repression and nitrogen control. Induction was observed when urate, allantoin or allantoate were included in the growth medium,

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

    Directory of Open Access Journals (Sweden)

    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%.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. 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.

  9. [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.

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

    OpenAIRE

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

    2009-01-01

    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 Pu...

  11. 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.

  12. 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

  13. 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.

  14. 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).

  15. 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

  16. 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.

  17. 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.

  18. Pseudomonas syringae evades host Immunity by degrading flagellin monomers with alkaline protease AprA

    OpenAIRE

    Pel, M.J.C.; Van Dijken, A.J.H.; Bardoel, B.W.; Seidl, M. F.; Van der Ent, S.; van Strijp, J. A. G.

    2014-01-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant athogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantl...

  19. 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.

  20. Degradation of Uniquely Glycosylated Secretory Immunoglobulin A in Tears From Patients With Pseudomonas aeruginosa Keratitis

    DEFF Research Database (Denmark)

    Lomholt, Jeanet Andersen; Kilian, Mogens

    2008-01-01

    PURPOSE. To investigate the integrity of secretory IgA (S-IgA) in tear fluid during bacterial keratitis and to evaluate the significance of specific Pseudomonas aeruginosa extracellular proteases in the observed degradation of S-IgA. METHODS. The integrity of component chains of S-IgA in tear fluid...... from patients with keratitis caused by P. aeruginosa, Streptococcus group G, Moraxella catarrhalis, Staphylococcus aureus, coagulase-negative staphylococci, and the IgA1 protease-producing Streptococcus pneumoniae were compared with S-IgA in tear fluid, colostrum, and saliva from healthy individuals......, and with tear S-IgA incubated with clinical isolates and genetically engineered P. aeruginosa strains with different protease profiles. Degradation of S-IgA and the significance of its glycosylation were analyzed in Western blots developed with antibodies against individual chains of S-IgA. RESULTS. Secretory...

  1. Functional redundancy in phenol and toluene degradation in Pseudomonas stutzeri strains isolated from the Baltic Sea.

    Science.gov (United States)

    Heinaru, Eeva; Naanuri, Eve; Grünbach, Maarja; Jõesaar, Merike; Heinaru, Ain

    2016-09-01

    In the present study we describe functional redundancy of bacterial multicomponent monooxygenases (toluene monooxygenase (TMO) and toluene/xylene monooxygenase (XylAM) of TOL pathway) and cooperative genetic regulation at the expression of the respective catabolic operons by touR and xylR encoded regulatory circuits in five phenol- and toluene-degrading Pseudomonas stutzeri strains. In these strains both toluene degradation pathways (TMO and Xyl) are active and induced by toluene and phenol. The whole genome sequence of the representative strain 2A20 revealed the presence of complete TMO- and Xyl-upper pathway operons together with two sets of lower catechol meta pathway operons, as well as phenol-degrading operon in a single 292,430bp contig. The much lower GC content and analysis of the predicted ORFs refer to the plasmid origin of the approximately 130kb region of this contig, containing the xyl, phe and tou genes. The deduced amino acid sequences of the TMO, XylA and the large subunit of phenol monooxygenase (LmPH) show 98-100% identity with the respective gene products of the strain Pseudomonas sp. OX1. In both strains 2A20 and OX1 the meta-cleavage pathways for catechol degradation are coded by two redundant operons (phe and xyl). We show that in the strain 2A20 TouR and XylR are activated by different effector molecules, phenol and toluene, respectively, and they both control transcription of the xyl upper, tou (TMO) and phe catabolic operons. Although the growth parameters of redundant strains did not show advantage at toluene biodegradation, the functional redundancy could provide better flexibility to the bacteria in environmental conditions. PMID:27185632

  2. Bidirectional gene sequences with similar homology to functional proteins of alkane degrading bacterium pseudomonas fredriksbergensis DNA

    International Nuclear Information System (INIS)

    The potential for two overlapping fragments of DNA from a clone of newly isolated alkanes degrading bacterium Pseudomonas frederiksbergensis encoding sequences with similar homology to two parts of functional proteins is described. One strand contains a sequence with high homology to alkanes monooxygenase (alkB), a member of the alkanes hydroxylase family, and the other strand contains a sequence with some homology to alcohol dehydrogenase gene (alkJ). Overlapping of the genes on opposite strands has been reported in eukaryotic species, and is now reported in a bacterial species. The sequence comparisons and ORFS results revealed that the regulation and the genes organization involved in alkane oxidation represented in Pseudomonas frederiksberghensis varies among the different known alkane degrading bacteria. The alk gene cluster containing homologues to the known alkane monooxygenase (alkB), and rubredoxin (alkG) are oriented in the same direction, whereas alcohol dehydrogenase (alkJ) is oriented in the opposite direction. Such genomes encode messages on both strands of the DNA, or in an overlapping but different reading frames, of the same strand of DNA. The possibility of creating novel genes from pre-existing sequences, known as overprinting, which is a widespread phenomenon in small viruses. Here, the origin and evolution of the gene overlap to bacteriophages belonging to the family Microviridae have been investigated. Such a phenomenon is most widely described in extremely small genomes such as those of viruses or small plasmids, yet here is a unique phenomenon. (author)

  3. 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.

  4. 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.

  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. 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.

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

    OpenAIRE

    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 of toluene and TCE in steady-state continuous culture. The organism was grown in a chemostat,vith toluene as the carbon and energy source at a range of volumetric TCE loading rates, up to 330 mu mo...

  8. 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. PMID:26368799

  9. A novel Pseudomonas gessardii strain LZ-E simultaneously degrades naphthalene and reduces hexavalent chromium.

    Science.gov (United States)

    Huang, Haiying; Wu, Kejia; Khan, Aman; Jiang, Yiming; Ling, Zhenmin; Liu, Pu; Chen, Yong; Tao, Xuanyu; Li, Xiangkai

    2016-05-01

    Combined pollutants with polycyclic aromatic hydrocarbons (PAHs) and heavy metals have been identified as toxic and unmanageable contaminates. In this work, Pseudomonas gessardii strain LZ-E isolated from wastewater discharge site of a petrochemical company degrades naphthalene and reduces Cr(VI) simultaneously. 95% of 10mgL(-1) Cr(VI) was reduced to Cr(III) while 77% of 800mgL(-1) naphthalene was degraded when strain LZ-E was incubated in BH medium for 48h. Furthermore, naphthalene promotes Cr(VI) reduction in strain LZ-E as catechol and phthalic acid produced in naphthalene degradation are able to reduce Cr(VI) abiotically. An aerated bioreactor system was setup to test strain LZ-E's remediation ability. Strain LZ-E continuously remediated naphthalene and Cr(VI) at rates of 15mgL(-1)h(-1) and 0.20mgL(-1)h(-1) of 800mgL(-1) naphthalene and 10mgL(-1) Cr(VI) addition with eight batches in 16days. In summary, strain LZ-E is a potential applicant for combined pollution remediation. PMID:26901089

  10. 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.

  11. 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.

  12. Pseudomonas aeruginosa lectin LecB inhibits tissue repair processes by triggering β-catenin degradation.

    Science.gov (United States)

    Cott, Catherine; Thuenauer, Roland; Landi, Alessia; Kühn, Katja; Juillot, Samuel; Imberty, Anne; Madl, Josef; Eierhoff, Thorsten; Römer, Winfried

    2016-06-01

    Pseudomonas aeruginosa is an opportunistic pathogen that induces severe lung infections such as ventilator-associated pneumonia and acute lung injury. Under these conditions, the bacterium diminishes epithelial integrity and inhibits tissue repair mechanisms, leading to persistent infections. Understanding the involved bacterial virulence factors and their mode of action is essential for the development of new therapeutic approaches. In our study we discovered a so far unknown effect of the P. aeruginosa lectin LecB on host cell physiology. LecB alone was sufficient to attenuate migration and proliferation of human lung epithelial cells and to induce transcriptional activity of NF-κB. These effects are characteristic of impaired tissue repair. Moreover, we found a strong degradation of β-catenin, which was partially recovered by the proteasome inhibitor lactacystin. In addition, LecB induced loss of cell-cell contacts and reduced expression of the β-catenin targets c-myc and cyclin D1. Blocking of LecB binding to host cell plasma membrane receptors by soluble l-fucose prevented these changes in host cell behavior and signaling, and thereby provides a powerful strategy to suppress LecB function. Our findings suggest that P. aeruginosa employs LecB as a virulence factor to induce β-catenin degradation, which then represses processes that are directly linked to tissue recovery. PMID:26862060

  13. Engineering of a silica encapsulation platform for hydrocarbon degradation using Pseudomonas sp. NCIB 9816-4.

    Science.gov (United States)

    Sakkos, Jonathan K; Kieffer, Daniel P; Mutlu, Baris R; Wackett, Lawrence P; Aksan, Alptekin

    2016-03-01

    Industrial application of encapsulated bacteria for biodegradation of hydrocarbons in water requires mechanically stable materials. A silica gel encapsulation method was optimized for Pseudomonas sp. NCIB 9816-4, a bacterium that degrades more than 100 aromatic hydrocarbons. The design process focused on three aspects: (i) mechanical property enhancement; (ii) gel cytocompatibility; and (iii) reduction of the diffusion barrier in the gel. Mechanical testing indicated that the compressive strength at failure (σf ) and elastic modulus (E) changed linearly with the amount of silicon alkoxide used in the gel composition. Measurement of naphthalene biodegradation by encapsulated cells indicated that the gel maintained cytocompatibility at lower levels of alkoxide. However, significant loss in activity was observed due to methanol formation during hydrolysis at high alkoxide concentrations, as measured by FTIR spectroscopy. The silica gel with the highest amount of alkoxide (without toxicity from methanol) had a biodegradation rate of 285 ± 42 nmol/L-s, σf  = 652 ± 88 kPa, and E = 15.8 ± 2.0 MPa. Biodegradation was sustained for 1 month before it dropped below 20% of the initial rate. In order to improve the diffusion through the gel, polyvinyl alcohol (PVA) was used as a porogen and resulted in a 48 ± 19% enhancement in biodegradation, but it impacted the mechanical properties negatively. This is the first report studying how the silica composition affects biodegradation of naphthalene by Pseudomonas sp. NCIB 9816-4 and establishes a foundation for future studies of aromatic hydrocarbon biodegradation for industrial application. PMID:26332745

  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. 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.

  16. Genome Sequences of the Lignin-Degrading Pseudomonas sp. Strain YS-1p and Rhizobium sp. Strain YS-1r Isolated from Decaying Wood

    OpenAIRE

    Prabhakaran, Madhu; Couger, Matthew B.; Jackson, Colin A.; Weirick, Tyler; Fathepure, Babu Z.

    2015-01-01

    Pseudomonas sp. strain YS-1p and Rhizobium sp. strain YS-1r were isolated from a lignin-degrading enrichment culture. The isolates degraded lignin-derived monomers, dimers, alkali lignin, and, to a smaller extent (3% to 5%), lignin in switch grass and alfalfa. Genome analysis revealed the presence of a variety of lignin-degrading genes.

  17. 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.

  18. 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...

  19. Entner-Doudoroff pathway for sulfoquinovose degradation in Pseudomonas putida SQ1.

    Science.gov (United States)

    Felux, Ann-Katrin; Spiteller, Dieter; Klebensberger, Janosch; Schleheck, David

    2015-08-01

    Sulfoquinovose (SQ; 6-deoxy-6-sulfoglucose) is the polar head group of the plant sulfolipid SQ-diacylglycerol, and SQ comprises a major proportion of the organosulfur in nature, where it is degraded by bacteria. A first degradation pathway for SQ has been demonstrated recently, a "sulfoglycolytic" pathway, in addition to the classical glycolytic (Embden-Meyerhof) pathway in Escherichia coli K-12; half of the carbon of SQ is abstracted as dihydroxyacetonephosphate (DHAP) and used for growth, whereas a C3-organosulfonate, 2,3-dihydroxypropane sulfonate (DHPS), is excreted. The environmental isolate Pseudomonas putida SQ1 is also able to use SQ for growth, and excretes a different C3-organosulfonate, 3-sulfolactate (SL). In this study, we revealed the catabolic pathway for SQ in P. putida SQ1 through differential proteomics and transcriptional analyses, by in vitro reconstitution of the complete pathway by five heterologously produced enzymes, and by identification of all four organosulfonate intermediates. The pathway follows a reaction sequence analogous to the Entner-Doudoroff pathway for glucose-6-phosphate: It involves an NAD(+)-dependent SQ dehydrogenase, 6-deoxy-6-sulfogluconolactone (SGL) lactonase, 6-deoxy-6-sulfogluconate (SG) dehydratase, and 2-keto-3,6-dideoxy-6-sulfogluconate (KDSG) aldolase. The aldolase reaction yields pyruvate, which supports growth of P. putida, and 3-sulfolactaldehyde (SLA), which is oxidized to SL by an NAD(P)(+)-dependent SLA dehydrogenase. All five enzymes are encoded in a single gene cluster that includes, for example, genes for transport and regulation. Homologous gene clusters were found in genomes of other P. putida strains, in other gamma-Proteobacteria, and in beta- and alpha-Proteobacteria, for example, in genomes of Enterobacteria, Vibrio, and Halomonas species, and in typical soil bacteria, such as Burkholderia, Herbaspirillum, and Rhizobium. PMID:26195800

  20. 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).

  1. 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.

  2. 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. PMID:24803113

  3. 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.

  4. 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.

  5. 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. PMID:25917649

  6. 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.

  7. Elucidating the Pseudomonas aeruginosa Fatty Acid Degradation Pathway: Identification of Additional Fatty Acyl-CoA Synthetase Homologues

    OpenAIRE

    Zarzycki-Siek, Jan; Norris, Michael H.; Kang, Yun (Kenneth); Sun, Zhenxin; Bluhm, Andrew P.; McMillan, Ian A.; Hoang, Tung T.

    2013-01-01

    The fatty acid (FA) degradation pathway of Pseudomonas aeruginosa, an opportunistic pathogen, was recently shown to be involved in nutrient acquisition during BALB/c mouse lung infection model. The source of FA in the lung is believed to be phosphatidylcholine, the major component of lung surfactant. Previous research indicated that P. aeruginosa has more than two fatty acyl-CoA synthetase genes (fadD; PA3299 and PA3300), which are responsible for activation of FAs using ATP and coenzyme A. T...

  8. Isolation of Pseudomonas pickettii strains that degrade 2,4,6-trichlorophenol and their dechlorination of chlorophenols.

    OpenAIRE

    Kiyohara, H.; Hatta, T; Ogawa, Y.; T Kakuda; H. Yokoyama; Takizawa, N

    1992-01-01

    Three strains of Pseudomonas pickettii that can grow with 2,4,6-trichlorophenol (2,4,6-TCP) as the sole source of carbon and energy were isolated from different mixed cultures of soil bacterial populations that had been acclimatized to 2,4,6-TCP. These strains released 3 mol of chloride ion from 1 mol of 2,4,6-TCP during the complete degradation of the TCP. Of these strains, P. pickettii DTP0602 in high-cell-density suspension cultures dechlorinated various chlorophenols (CPs). Cells that wer...

  9. Pseudomonas syringae evades host immunity by degrading flagellin monomers with alkaline protease AprA.

    Science.gov (United States)

    Pel, Michiel J C; van Dijken, Anja J H; Bardoel, Bart W; Seidl, Michael F; van der Ent, Sjoerd; van Strijp, Jos A G; Pieterse, Corné M J

    2014-07-01

    Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant pathogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantly less virulent on both tomato and Arabidopsis thaliana. Moreover, infiltration of A. thaliana Col-0 leaves with DC3000 ΔaprA evoked a significantly higher level of expression of the defense-related genes FRK1 and PR-1 than did wild-type DC3000. In the flagellin receptor mutant fls2, pathogen virulence and defense-related gene activation did not differ between DC3000 and DC3000 ΔaprA. Together, these results suggest that AprA of DC3000 is important for evasion of recognition by the FLS2 receptor, allowing wild-type DC3000 to be more virulent on its host plant than AprA-deficient DC3000 ΔaprA. To provide further evidence for the role of DC3000 AprA in host immune evasion, we overexpressed the AprA inhibitory peptide AprI of DC3000 in A. thaliana to counteract the immune evasive capacity of DC3000 AprA. Ectopic expression of aprI in A. thaliana resulted in an enhanced level of resistance against wild-type DC3000, while the already elevated level of resistance against DC3000 ΔaprA remained unchanged. Together, these results indicate that evasion of host immunity by the alkaline protease AprA is important for full virulence of strain DC3000 and likely acts by preventing flagellin monomers from being recognized by its cognate immune receptor. PMID:24654978

  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

    International Nuclear Information System (INIS)

    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 Ca3(PO4)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. Evaluation of the effects of a polyurethane carrier on the degradation of chlorinated anilines by Pseudomonas acidovorans CA50

    International Nuclear Information System (INIS)

    A previously described model system for the treatment of harzardous chloroaniline-containing waste waters using immobilized bacterial cells in a bioreactor was enhanced in its degradation efficiency. This was achieved by the substitution of the calcium alginate beads by an inert polyurethane (PU)-carrier. The supply of chloroaniline-polluted waste waters with the PU-carrier (1.25% w/v) resulted in a distinct decrease of the pollutant concentrations in the solution due to the effects of adsorption. Nevertheless, the initially bound amounts of the chloroanilines, were also degraded, which was proved by the chloride balance. In comparative batch-degradation experiments with the Pseudomonas acidovorans strain CA50 with and without the addition of the PU-carrier (1.25% v/w), respectively, the advantages of the PU-supplied treatment system were demonstrated; among others a marked shortening of the degradation periods was achieved. The advantage of the PU-carrier was also shown by using a bubble reactor. In this connection, it is particularly worth mentioning, that high degradation rates can be achieved for a long time even for strongly persistent pollutants. (orig.)

  14. 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

  15. 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.

  16. Biochemical Characterization of Phosphate Degrading Pseudomonas Cichorii Isolated From Forest Soils In Seshachalam Hills

    OpenAIRE

    G Prasada Babu; D Chakravarthy; K Jaya Kumar; Chinthala Paramageetham

    2013-01-01

    Pseudomonas cichoriiisolates were obtained from forest soils in Seshachalm hills using selective medium. The isolates were screened for phosphate activity and all the isolates were gram negative and showed bright fluorescence under UV light. The cultural and biochemical characteristics confirmed that the isolates were P.cichorii. Carbohydrates utilization profiles confirmed that the isolates were able to utilize Lactose, Xylose, Fructose, Glycerol, Trehalose, Mannitol and Ribose. However, the...

  17. Pseudomonas aeruginosa alkaline protease degrades human gamma interferon and inhibits its bioactivity.

    OpenAIRE

    Horvat, R T; Parmely, M J

    1988-01-01

    This study was performed to determine the effect of Pseudomonas aeruginosa on gamma interferon (IFN-gamma) production by antigen-stimulated human T-cell clones. Crude bacterial filtrates prepared from certain strains of P. aeruginosa inhibited IFN-gamma production by T cells and reduced the antiviral activity of preformed IFN-gamma. Bacterial filtrates prepared from mutant strains that did not produce the exoenzyme alkaline protease (AP) did not inhibit IFN-gamma activity. The inhibitory acti...

  18. Effect of degradative plasmid CAM-OCT on responses of Pseudomonas bacteria to UV light

    International Nuclear Information System (INIS)

    The effect of plasmid CAM-OCT on responses to UV irradiation was compared in Pseudomonas aeruginosa, in Pseudomonas putida, and in Pseudomonas putida mutants carrying mutations in UV response genes. CAM-OCT substantially increased both survival and mutagenesis in the two species. P. aeruginosa strains without CAM-OCT exhibited much higher UV sensitivity than did P. putida strains. UV-induced mutagenesis of plasmid-free P. putida was easily detected in three different assays (two reversion assays and one forward mutation assay), whereas UV mutagenesis of P. aeruginosa without CAM-OCT was seen only in the forward mutation assay. These results suggest major differences in DNA repair between the two species and highlight the presence of error-prone repair functions on CAM-OCT. A number of P. putida mutants carrying chromosomal mutations affecting either survival or mutagenesis after UV irradiation were isolated, and the effect of CAM-OCT on these mutants was determined. All mutations producing a UV-sensitive phenotype in P. putida were fully suppressed by the plasmid, whereas the plasmid had a more variable effect on mutagenesis mutations, suppressing some and producing no suppression of others. On the basis of the results reported here and results obtained by others with plasmids carrying UV response genes, it appears that CAM-OCT may differ either in regulation or in the number and functions of UV response genes encoded

  19. 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.

  20. METABOLISM OF POLY(3-HYDROXYALKANOATES) (PHAS) BY PSEUDOMONAS-OLEOVORANS - IDENTIFICATION AND SEQUENCES OF GENES AND FUNCTION OF THE ENCODED PROTEINS IN THE SYNTHESIS AND DEGRADATION OF PHA

    NARCIS (Netherlands)

    HUISMAN, GW; WONINK, E; MEIMA, R; KAZEMIER, B; TERPSTRA, P; WITHOLT, B

    1991-01-01

    Pseudomonas oleovorans accumulates poly(3-hydroxyalkanoates) (PHAs) after growth on medium chain length hydrocarbons. Large amounts of this polyester are synthesized when cells are grown under nitrogen-limiting conditions. When nitrogen is resupplied in the medium, the accumulated PHA is degraded. I

  1. 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.

  2. 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...

  3. Metabolism of Poly(3-hydroxyalkanoates) (PHAs) by Pseudomonas oleovorans. Identification and Sequences of Genes and Function of the Encoded Proteins in the Synthesis and Degradation of PHA

    NARCIS (Netherlands)

    Huisman, Gjalt W.; Wonink, Eric; Meima, Rob; Kazemier, Bert; Terpstra, Peter; Witholt, Bernard

    1991-01-01

    Pseudomonas oleovorans accumulates poly(3-hydroxyalkanoates) (PHAs) after growth on medium chain length hydrocarbons. Large amounts of this polyester are synthesized when cells are grown under nitrogen-limiting conditions. When nitrogen is resupplied in the medium, the accumulated PHA is degraded. I

  4. Biochemical Characterization of Phosphate Degrading Pseudomonas Cichorii Isolated From Forest Soils In Seshachalam Hills

    Directory of Open Access Journals (Sweden)

    G Prasada Babu

    2013-03-01

    Full Text Available Pseudomonas cichoriiisolates were obtained from forest soils in Seshachalm hills using selective medium. The isolates were screened for phosphate activity and all the isolates were gram negative and showed bright fluorescence under UV light. The cultural and biochemical characteristics confirmed that the isolates were P.cichorii. Carbohydrates utilization profiles confirmed that the isolates were able to utilize Lactose, Xylose, Fructose, Glycerol, Trehalose, Mannitol and Ribose. However, the isolates were unable to utilize glucose and sucrose. The isolates showed positive results for levan production, oxidase and HCN. However they were negative for citrate utilization, ONPG and Gelatin hydrolysis.

  5. Elucidating the Pseudomonas aeruginosa fatty acid degradation pathway: identification of additional fatty acyl-CoA synthetase homologues.

    Directory of Open Access Journals (Sweden)

    Jan Zarzycki-Siek

    Full Text Available The fatty acid (FA degradation pathway of Pseudomonas aeruginosa, an opportunistic pathogen, was recently shown to be involved in nutrient acquisition during BALB/c mouse lung infection model. The source of FA in the lung is believed to be phosphatidylcholine, the major component of lung surfactant. Previous research indicated that P. aeruginosa has more than two fatty acyl-CoA synthetase genes (fadD; PA3299 and PA3300, which are responsible for activation of FAs using ATP and coenzyme A. Through a bioinformatics approach, 11 candidate genes were identified by their homology to the Escherichia coli FadD in the present study. Four new homologues of fadD (PA1617, PA2893, PA3860, and PA3924 were functionally confirmed by their ability to complement the E. coli fadD mutant on FA-containing media. Growth phenotypes of 17 combinatorial fadD mutants on different FAs, as sole carbon sources, indicated that the four new fadD homologues are involved in FA degradation, bringing the total number of P. aeruginosa fadD genes to six. Of the four new homologues, fadD4 (PA1617 contributed the most to the degradation of different chain length FAs. Growth patterns of various fadD mutants on plant-based perfumery substances, citronellic and geranic acids, as sole carbon and energy sources indicated that fadD4 is also involved in the degradation of these plant-derived compounds. A decrease in fitness of the sextuple fadD mutant, relative to the ΔfadD1D2 mutant, was only observed during BALB/c mouse lung infection at 24 h.

  6. Elucidating the Pseudomonas aeruginosa fatty acid degradation pathway: identification of additional fatty acyl-CoA synthetase homologues.

    Science.gov (United States)

    Zarzycki-Siek, Jan; Norris, Michael H; Kang, Yun; Sun, Zhenxin; Bluhm, Andrew P; McMillan, Ian A; Hoang, Tung T

    2013-01-01

    The fatty acid (FA) degradation pathway of Pseudomonas aeruginosa, an opportunistic pathogen, was recently shown to be involved in nutrient acquisition during BALB/c mouse lung infection model. The source of FA in the lung is believed to be phosphatidylcholine, the major component of lung surfactant. Previous research indicated that P. aeruginosa has more than two fatty acyl-CoA synthetase genes (fadD; PA3299 and PA3300), which are responsible for activation of FAs using ATP and coenzyme A. Through a bioinformatics approach, 11 candidate genes were identified by their homology to the Escherichia coli FadD in the present study. Four new homologues of fadD (PA1617, PA2893, PA3860, and PA3924) were functionally confirmed by their ability to complement the E. coli fadD mutant on FA-containing media. Growth phenotypes of 17 combinatorial fadD mutants on different FAs, as sole carbon sources, indicated that the four new fadD homologues are involved in FA degradation, bringing the total number of P. aeruginosa fadD genes to six. Of the four new homologues, fadD4 (PA1617) contributed the most to the degradation of different chain length FAs. Growth patterns of various fadD mutants on plant-based perfumery substances, citronellic and geranic acids, as sole carbon and energy sources indicated that fadD4 is also involved in the degradation of these plant-derived compounds. A decrease in fitness of the sextuple fadD mutant, relative to the ΔfadD1D2 mutant, was only observed during BALB/c mouse lung infection at 24 h. PMID:23737986

  7. 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. PMID:22998548

  8. Characterization and biodegradation kinetics of a new cold-adapted carbamazepine-degrading bacterium, Pseudomonas sp. CBZ-4.

    Science.gov (United States)

    Li, Ang; Cai, Rui; Di, Cui; Qiu, Tian; Pang, Changlong; Yang, Jixian; Ma, Fang; Ren, Nanqi

    2013-11-01

    Carbamazepine is frequently detected in waters and hardly eliminated during conventional wastewater treatment processes due to its complicated chemical structure and resistance to biodegradation. A carbamazepine-degrading bacterium named CBZ-4 was isolated at a low temperature (10 degreeC) from activated sludge in a municipal wastewater treatment plant. Strain CBZ-4, which can use carbamazepine as its sole source of carbon and energy, was identified as Pseudomonas sp. by the 16S rRNA gene sequence. The composition and percentage of fatty acids, which can reveal the cold-adaptation mechanism of strain CBZ-4, were determined. Strain CBZ-4 can effectively degrade carbamazepine at optimal conditions: pH 7.0, 10 degreeC, 150 r/min rotation speed, and 13% inoculation volume. The average removal rate of carbamazepine was 46.6% after 144 hr of incubation. The biodegradation kinetics of carbamazepine by CBZ-4 was fitted via the Monod model. Vmax and Ks were found to be 0.0094 hr-1 and 32.5 mg/L, respectively. PMID:24552057

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Towards a Biocatalyst for (S)-Styrene Oxide Production: Characterization of the Styrene Degradation Pathway of Pseudomonas sp. Strain VLB120

    OpenAIRE

    Panke, Sven; Witholt, Bernard; Schmid, Andreas; Wubbolts, Marcel G.

    1998-01-01

    In order to design a biocatalyst for the production of optically pure styrene oxide, an important building block in organic synthesis, the metabolic pathway and molecular biology of styrene degradation in Pseudomonas sp. strain VLB120 was investigated. A 5.7-kb XhoI fragment, which contained on the same strand of DNA six genes involved in styrene degradation, was isolated from a gene library of this organism in Escherichia coli by screening for indigo formation. T7 RNA polymerase expression e...

  15. Pseudomonas aeruginosa RRALC3 Enhances the Biomass, Nutrient and Carbon Contents of Pongamia pinnata Seedlings in Degraded Forest Soil.

    Directory of Open Access Journals (Sweden)

    Parthasarathy Radhapriya

    Full Text Available The study was aimed at assessing the effects of indigenous Plant Growth Promoting Bacterium (PGPB on the legume Pongamia pinnata in the degraded soil of the Nanmangalam Reserve Forest (NRF under nursery conditions. In total, 160 diazotrophs were isolated from three different nitrogen-free semi-solid media (LGI, Nfb, and JMV. Amongst these isolates, Pseudomonas aeruginosa RRALC3 exhibited the maximum ammonia production and hence was selected for further studies. RRALC3 was found to possess multiple plant growth promoting traits such as nitrogen accumulation (120.6ppm; it yielded a positive amplicon with nifH specific primers, tested positive for Indole Acetic Acid (IAA; 18.3μg/ml and siderophore production, tested negative for HCN production and was observed to promote solubilization of phosphate, silicate and zinc in the plate assay. The 16S rDNA sequence of RRALC3 exhibited 99% sequence similarity to Pseudomonas aeruginosa JCM5962. Absence of virulence genes and non-hemolytic activity indicated that RRALC3 is unlikely to be a human pathogen. When the effects of RRALC3 on promotion of plant growth was tested in Pongamia pinnata, it was observed that in Pongamia seedlings treated with a combination of RRALC3 and chemical fertilizer, the dry matter increased by 30.75%. Nitrogen, phosphorus and potassium uptake increased by 34.1%, 27.08%, and 31.84%, respectively, when compared to control. Significant enhancement of total sugar, amino acids and organic acids content, by 23.4%, 29.39%, and 26.53% respectively, was seen in the root exudates of P. pinnata. The carbon content appreciated by 4-fold, when fertilized seedlings were treated with RRALC3. From the logistic equation, the rapid C accumulation time of Pongamia was computed as 43 days longer than the control when a combination of native PGPB and inorganic fertilizer was applied. The rapid accumulation time of N, P and K in Pongamia when treated with the same combination as above was 15, 40 and

  16. Pseudomonas aeruginosa RRALC3 Enhances the Biomass, Nutrient and Carbon Contents of Pongamia pinnata Seedlings in Degraded Forest Soil.

    Science.gov (United States)

    Radhapriya, Parthasarathy; Ramachandran, Andimuthu; Anandham, Rangasamy; Mahalingam, Sundararajan

    2015-01-01

    The study was aimed at assessing the effects of indigenous Plant Growth Promoting Bacterium (PGPB) on the legume Pongamia pinnata in the degraded soil of the Nanmangalam Reserve Forest (NRF) under nursery conditions. In total, 160 diazotrophs were isolated from three different nitrogen-free semi-solid media (LGI, Nfb, and JMV). Amongst these isolates, Pseudomonas aeruginosa RRALC3 exhibited the maximum ammonia production and hence was selected for further studies. RRALC3 was found to possess multiple plant growth promoting traits such as nitrogen accumulation (120.6ppm); it yielded a positive amplicon with nifH specific primers, tested positive for Indole Acetic Acid (IAA; 18.3μg/ml) and siderophore production, tested negative for HCN production and was observed to promote solubilization of phosphate, silicate and zinc in the plate assay. The 16S rDNA sequence of RRALC3 exhibited 99% sequence similarity to Pseudomonas aeruginosa JCM5962. Absence of virulence genes and non-hemolytic activity indicated that RRALC3 is unlikely to be a human pathogen. When the effects of RRALC3 on promotion of plant growth was tested in Pongamia pinnata, it was observed that in Pongamia seedlings treated with a combination of RRALC3 and chemical fertilizer, the dry matter increased by 30.75%. Nitrogen, phosphorus and potassium uptake increased by 34.1%, 27.08%, and 31.84%, respectively, when compared to control. Significant enhancement of total sugar, amino acids and organic acids content, by 23.4%, 29.39%, and 26.53% respectively, was seen in the root exudates of P. pinnata. The carbon content appreciated by 4-fold, when fertilized seedlings were treated with RRALC3. From the logistic equation, the rapid C accumulation time of Pongamia was computed as 43 days longer than the control when a combination of native PGPB and inorganic fertilizer was applied. The rapid accumulation time of N, P and K in Pongamia when treated with the same combination as above was 15, 40 and 33 days longer

  17. Activity and three-dimensional distribution of toluene-degrading Pseudomonas putida in a multispecies biofilm assessed by quantitative in situ hybridization and scanning confocal laser microscopy

    DEFF Research Database (Denmark)

    Møller, Søren; Pedersen, Anne Rathmann; Poulsen, L.K.;

    1996-01-01

    As a representative member of the toluene-degrading population in a biofilter for waste gas treatment, Pseudomonas putida was investigated with a 16S rRNA targeting probe, The three-dimensional distribution of P. putida was visualized in the biofilm matrix by scanning confocal laser microscopy...... at a maximal rate in the biofilm environment, Assuming that the rRNA content reflected the cellular activity, a lower toluene degradation rate for P. putida present in the biofilm could be estimated, This calculation Indicated that P. putida mas responsible for a significant part (65%) of the toluene...... consequently P. putida may be actively degrading toluene in all regions of the biofilm. Furthermore, measurements of growth rate-related parameters fur P. putida showed reduced I RNA content and cell size (relative to that ill a batch culture), indicating that the P. putida population mas not degrading toluene...

  18. 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.

  19. AntR-mediated bidirectional activation of antA and antR, anthranilate degradative genes in Pseudomonas aeruginosa.

    Science.gov (United States)

    Kim, Soo-Kyoung; Im, Su-Jin; Yeom, Doo-Hwan; Lee, Joon-Hee

    2012-08-15

    Bidirectional activation of transcription is a peculiar regulation mode of gene expression. In this study, we show that genes involved in the metabolism of anthranilate, a precursor of biosynthesis of tryptophan and Pseudomonas quinolone signal (PQS) are regulated by this bidirectional activation of transcription. Anthranilate is degraded by anthranilate dioxygenase complex encoded by antABC operon, and AntR, a LysR-type regulator encoded by antR activates the transcription of antABC operon in the presence of anthranilate. In P. aeruginosa, antABC and antR are divergently located and AntR binds to the intergenic region between antA and antR to activate the antABC transcription. In this study, we determined the transcriptional start site of the antA promoter (antA(p)) and AntR-responsive elements (AREs) in P. aeruginosa. The upstream deletion analysis of antA(p) and in vitro gel shift assay with purified AntR showed that there are two AREs at -194 to -148 and -88 to -47 regions. We also found that AntR activates antR promoter (antR(p)) in the opposite direction and both AREs are important in the bidirectional activation of antA(p) and antR(p). Two AREs have different binding affinities to AntR and the strength of transcriptional activation was dramatically asymmetric depending on the direction. We suggest that the different affinities of two AREs may explain the asymmetry of the bidirectional activation by AntR. PMID:22609066

  20. Construction and analysis of an intergeneric fusion from Pigmentiphaga sp. strain AAP-1 and Pseudomonas sp. CTN-4 for degrading acetamiprid and chlorothalonil.

    Science.gov (United States)

    Wang, Guangli; Zhu, Danfeng; Xiong, Minghua; Zhang, Hui; Liu, Yuan

    2016-07-01

    Pseudomonas sp. CTN-4 degrades chlorothalonil (CTN) but not acetamiprid (AAP), and Pigmentiphaga sp. strain AAP-1 degrades AAP but not CTN. A functional strain, AC, was constructed through protoplast fusion of two parental strains (Pseudomonas sp. CTN-4 and Pigmentiphaga sp. strain AAP-1) in order to simultaneously improve the degradation efficiency of AAP and CTN. Fusant-AC with eight transfers on plates containing two antibiotics and CTN was obtained. For the purpose of identifying and confirming the genetic relationship between fusant-AC and its parents, randomly amplified polymorphic DNA (RAPD), scanning electron microscopy (SEM), and 16S ribosomal DNA (rDNA) analysis were performed. In toto, RAPD fingerprint analysis produced 194 clear bands with 9 primers, which not only had bands in common with strains CTN-4 and AAP-1, but also had its own novel fusant-specific bands. The genetic similarity indices between fusant-AC and parental strains CTN-4 and AAP-1 were 0.40 and 0.69, respectively. The result of SEM indicated that the cell morphology of fusant-AC differed from both its parents. The fusant strain AC possesses a strong capability for AAP and CTN degradation. At AAP concentration (50-300 mg L(-1)), the degradation was achieved within 5 h. At the initial dose of 50 and 100 mg L(-1) CTN, the percentages reached 96 and 91 % over a 36-h incubation period. The present study indicates that the protoplast-fusion technique may have possible applications in environmental pollution control. PMID:27023810

  1. 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.

  2. 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.

  3. Quinoline-degrading strain Pseudomonas aeruginosa KDQ4 isolated from coking activated sludge is capable of the simultaneous removal of phenol in a dual substrate system.

    Science.gov (United States)

    Zhang, Panhong; Jia, Rong; Zhang, Yuxiu; Shi, Peili; Chai, Tuanyao

    2016-11-01

    Quinoline is a refractory organic compound in the treatment of coking wastewater. The isolation of high efficiency quinoline-degrading bacteria from activated sludge and the evaluation of their degradation characteristics in the presence of phenol or in the actual coking wastewater are important for the improvement of effluent quality. The novel bacterial strain Pseudomonas aeruginosa KDQ4 was isolated from a quinoline enrichment culture obtained from the activated sludge of a coking wastewater treatment plant. The optimum temperature and initial pH for quinoline degradation were 33-38°C and 8-9, respectively. KDQ4 completely degraded 400 mg/L of quinoline within 24 h and 800 mg/L of phenol within 30 h. In the dual-substrate system, the removal efficiencies of quinoline and phenol at the same initial concentration (200 mg/L) by KDQ4 were 89% and 100% within 24 h, respectively, indicating that KDQ4 could simultaneously and quickly degrade quinoline and phenol in a coexistence system. Moreover, KDQ4 was able to adapt to actual coking wastewater containing high quinoline and phenol concentrations and rapidly remove them. KDQ4 also exhibited heterotrophic nitrification and aerobic denitrification potential under aerobic conditions. These results suggested a potential bioaugmentation role for KDQ4 in the removal of nitrogen-heterocyclic compounds and phenolics from coking wastewater. PMID:27458688

  4. Synthesis of Benzo[a]carbazoles and an Indolo[2,3-a]carbazole from 3-Aryltetramic Acids.

    Science.gov (United States)

    Truax, Nathanyal J; Banales Mejia, Fernando; Kwansare, Deborah O; Lafferty, Megan M; Kean, Maeve H; Pelkey, Erin T

    2016-08-01

    A simple and flexible approach to 3-pyrrolin-2-one fused carbazoles is disclosed. The key step involves the BF3-mediated electrophilic substitution of indoles with N-alkyl-substituted 3-aryltetramic acids, which provides access to indole-substituted 3-pyrrolin-2-ones. Scholl-type oxidative cyclizations of these materials led to the formation of the corresponding 3-pyrrolin-2-one-fused benzo[a]carbazoles and indolo[2,3-a]carbazoles. This work represents the first synthesis of the benzo[a]pyrrolo[3,4-c]carbazol-3(8H)-one ring system, while the indolo[2,3-a]pyrrolo[3,4-c]carbazol-5-one ring system is found in a number of biologically active compounds including the protein kinase C (PKC) inhibitor, staurosporine. PMID:27391374

  5. 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.

  6. 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.

  7. Draft Genome Sequence of Pseudomonas sp. Strain 10-1B, a Polycyclic Aromatic Hydrocarbon Degrader in Contaminated Soil

    OpenAIRE

    Bello-Akinosho, Maryam; Adeleke, Rasheed; Swanevelder, Dirk; Thantsha, Mapitsi

    2015-01-01

    Pseudomonas sp. strain 10-1B was isolated from artificially polluted soil after selective enrichment. Its draft genome consists of several predicted genes that are involved in the hydroxylation of the aromatic ring, which is the rate-limiting step in the biodegradation of polycyclic aromatic hydrocarbons.

  8. A newly isolated Pseudomonas putida S-1 strain for batch-mode-propanethiol degradation and continuous treatment of propanethiol-containing waste gas.

    Science.gov (United States)

    Chen, Dong-Zhi; Sun, Yi-Ming; Han, Li-Mei; Chen, Jing; Ye, Jie-Xu; Chen, Jian-Meng

    2016-01-25

    Pseudomonas putida S-1 was isolated from activated sludge. This novel strain was capable of degrading malodorous 1-propanethiol (PT). PT degradation commenced with no lag phase by cells pre-grown in nutrition-rich media, such as Luria-Bertani (LB), and PT-contained mineral medium at specific growth rates of 0.10-0.19 h(-1); this phenomenon indicated the operability of a large-scale cell culture. A possible PT degradation pathway was proposed on the basis of the detected metabolites, including dipropyl disulfide, 3-hexanone, 2-hexanone, 3-hexanol, 2-hexanol, S(0), SO4(2-), and CO2. P. putida S-1 could degrade mixed pollutants containing PT, diethyl disulfide, isopropyl alcohol, and acetaldehyde, and LB-pre-cultured cells underwent diauxic growth. Waste gas contaminated with 200-400 mg/m(3) PT was continuously treated by P. putida S-1 pre-cultured in LB medium in a completely stirred tank reactor. The removal efficiencies exceeded 88% when PT stream was mixed with 200 mg/m(3) isopropanol; by contrast, the removal efficiencies decreased to 60% as the empty bed residence time was shortened from 40 s to 20 s. PMID:26476310

  9. 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

    2016-01-01

    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.

  10. 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

    2016-01-01

    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. PMID:27323173

  11. A New Binary Carbazole Alkaloid from Murraya koenigii

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new binary carbazole alkaloid, 8, 8"-biskoenigine (1), along with its monomer,kocnigine, was isolated from the dried leaves of Murraya koenigii collected in Xishuangbanna,Yunnan province. The structure of 1 was established by spectroscopic methods.

  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. PMID:27131305

  13. 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.

  14. 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.

  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. Expression, purification and preliminary crystallographic studies of NahF, a salicylaldehyde dehydrogenase from Pseudomonas putida G7 involved in naphthalene degradation

    International Nuclear Information System (INIS)

    NahF is a salicylaldehyde dehydrogenase that is involved in the naphthalene-degradation pathway, converting salicylaldehyde into salicylate. The subcloning, expression, purification and preliminary X-ray diffraction studies at 2.42 Å resolution of P. putida G7 NahF are reported. Pseudomonas putida G7 is one of the most studied naphthalene-degrading species. The nah operon in P. putida, which is present on the 83 kb metabolic plasmid NAH7, codes for enzymes involved in the conversion of naphthalene to salicylate. The enzyme NahF (salicylaldehyde dehydrogenase) catalyzes the last reaction in this pathway. The nahF gene was subcloned into the pET28a(TEV) vector and the recombinant protein was overexpressed in Escherichia coli Arctic Express at 285 K. The soluble protein was purified by affinity chromatography followed by gel filtration. Crystals of recombinant NahF (6×His-NahF) were obtained at 291 K and diffracted to 2.42 Å resolution. They belonged to the hexagonal space group P6422, with unit-cell parameters a = b = 169.47, c = 157.94 Å. The asymmetric unit contained a monomer and a crystallographic twofold axis generated the dimeric biological unit

  18. Blocking phosphatidylcholine utilization in Pseudomonas aeruginosa, via mutagenesis of fatty acid, glycerol and choline degradation pathways, confirms the importance of this nutrient source in vivo.

    Directory of Open Access Journals (Sweden)

    Zhenxin Sun

    Full Text Available Pseudomonas aeruginosa can grow to very high-cell-density (HCD during infection of the cystic fibrosis (CF lung. Phosphatidylcholine (PC, the major component of lung surfactant, has been hypothesized to support HCD growth of P. aeruginosa in vivo. The phosphorylcholine headgroup, a glycerol molecule, and two long-chain fatty acids (FAs are released by enzymatic cleavage of PC by bacterial phospholipase C and lipases. Three different bacterial pathways, the choline, glycerol, and fatty acid degradation pathways, are then involved in the degradation of these PC components. Here, we identified five potential FA degradation (Fad related fadBA-operons (fadBA1-5, each encoding 3-hydroxyacyl-CoA dehydrogenase and acyl-CoA thiolase. Through mutagenesis and growth analyses, we showed that three (fadBA145 of the five fadBA-operons are dominant in medium-chain and long-chain Fad. The triple fadBA145 mutant also showed reduced ability to degrade PC in vitro. We have previously shown that by partially blocking Fad, via mutagenesis of fadBA5 and fadDs, we could significantly reduce the ability of P. aeruginosa to replicate on FA and PC in vitro, as well as in the mouse lung. However, no studies have assessed the ability of mutants, defective in choline and/or glycerol degradation in conjunction with Fad, to grow on PC or in vivo. Hence, we constructed additional mutants (ΔfadBA145ΔglpD, ΔfadBA145ΔbetAB, and ΔfadBA145ΔbetABΔglpD significantly defective in the ability to degrade FA, choline, and glycerol and, therefore, PC. The analysis of these mutants in the BALB/c mouse lung infection model showed significant inability to utilize PC in vitro, resulted in decreased replication fitness and competitiveness in vivo compared to the complement strain, although there was little to no variation in typical virulence factor production (e.g., hemolysin, lipase, and protease levels. This further supports the hypothesis that lung surfactant PC serves as an

  19. 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.

  20. 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.

  1. 游离和固定化恶臭假单胞菌对含酚废水的处理%DEGRADATION OF PHENOL BY FREE AND IMMOBILIZED PSEUDOMONAS PUTIDA

    Institute of Scientific and Technical Information of China (English)

    尹艳娥; 徐兆礼; 徐亚岩; 康伟; 鲁超

    2012-01-01

    采用恶臭假单胞菌,以活性炭纤维为载体,以聚乙烯醇( PVA)为包埋剂制成固定化恶臭假单胞菌,对含酚废水的降解效果进行研究.与游离恶臭假单胞菌相比,固定化恶臭假单胞菌小球的运行周期长,对苯酚的降解效果好.讨论了外部环境因素包括苯酚的初始质量浓度、pH和温度对固定化恶臭假单胞菌降解苯酚效果的影响.结果表明,随着苯酚质量浓度的增加,固定化恶臭假单胞菌对苯酚具有良好的降解效果;当苯酚初始质量浓度大于200 mg/L时,固定化恶臭假单胞菌降解苯酚的效果远远优越于游离态的;固定化恶臭假单胞菌对高质量浓度的苯酚、pH和温度的变化表现出了较好的耐受力;当pH为7~9,温度在30~35℃,固定化恶臭假单胞菌对苯酚的降解效果达到93%.%Pseudomonas putida were immobilized on activated carbon fiber (ACF) by using polyvinyl alcohol(PVA) as embedding material. Immobilized pseudomonas putida were used to treat synthetic wastewater containing phenol. Comparing with free pseudomonas putida, immobilized pseudomonas putida exhibited a longer operation time and better degradation rate. The factors affecting phenol degradation by immobilized pseudomonas putida were investigated, and the results showed that immobilized pseudomonas putida displayed better phenol removing efficiencies with the increasing of phenol concentrations. When phenol concentrations were over 200 mg/L the phenol removing efficiencies was better by immobilized pseudomonas putida than free pseudomonas putida. Immobilized pseudomonas putida could lerate a high phenol level and protected the bacteria against changes in temperature and pH. The results showed when pH value was 7~9 and temperature was 30-35 ℃ ,the removal rate was 93%.

  2. 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.

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

    International Nuclear Information System (INIS)

    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- L-1 O.D.-1 h-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- L-1 O.D.-1 h-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.

  4. 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.

  5. Synthesis and Characterization of Carbazole-Linked Porphyrin Tweezers.

    Science.gov (United States)

    Chang, Yi; Michelin, Clément; Bucher, Léo; Desbois, Nicolas; Gros, Claude P; Piant, Sébastien; Bolze, Frédéric; Fang, Yuanyuan; Jiang, Xiaoqin; Kadish, Karl M

    2015-08-17

    Herein the synthesis, spectroscopic characterization, two-photon absorption and electrochemical properties of 3,6-disubstituted carbazole tweezers is reported. A dimer resulting from a Glaser homocoupling was isolated during a Sonogashira coupling reaction between a diethynyl-carbazole spacer and a 5-bromo-triarylporphyrin and the properties of this original compound were compared with the 3,6-disubstituted carbazole bisporphyrin tweezers. The dyads reported herein present a two-photon absorption maximum at 920 nm with two-photon absorption cross-section in the 1200 GM range. Despite a strong linear absorption in the Soret region and moderate fluorescence quantum yield, they both lead to a high brightness reaching 30 000 M(-1)  cm(-1) . PMID:26177731

  6. 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.

  7. 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.

  8. Synthesis and characterizations of carbazole-isoindigo-carbazole oligomers for photovoltaic application

    Science.gov (United States)

    Lee, Ji-Young; Lee, Song-Mi; Lee, Soo-Hyoung; Kim, Dong-Hee; Lee, Sang Hee; Lee, Youn-Sik

    2016-08-01

    6,6‧-Dibromo-N,N‧-(2-octyldodecanyl)isoindigo was coupled to either 4-(N-carbazolyl)phenyl boronic acid or 9-phenyl-9H-carbazole-3-boronic acid to give two different conjugated molecules of P-II-P and C-II-C, respectively. The optical band gap/HOMO levels of P-II-P and C-II-C were 1.90/-5.60 eV and 1.85/-5.39 eV, respectively. Based on the experimental and calculation data, C-II-C is more highly conjugated than P-II-P. The performances of C-II-C-based photovoltaic devices were better than those of P-II-P-based devices, with the best power conversion efficiency of 0.44%.

  9. 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

  10. 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.

  11. 9-Hexyl-3-iodo-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Wen-Qian Geng

    2010-01-01

    Full Text Available In the title molecule, C18H20IN, the tricyclic carbazole system is essentially planar with the two outer rings forming a dihedral angle of 0.43 (8°. The crystal packing exhibits no short intermolecular contacts.

  12. 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

  13. 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.

  14. 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.

  15. Efficient and Simple Synthesis of 6-Aryl-1,4-dimethyl-9H-carbazoles

    Directory of Open Access Journals (Sweden)

    Sylvain Rault

    2008-06-01

    Full Text Available A synthetic method for the preparation of 6-aryl-1,4-dimethyl-9H-carbazoles involving a palladium catalyzed coupling reaction of 1,4-dimethyl-9H-carbazole-6-boronic acids and (heteroaryl halides is described.

  16. 76 FR 24855 - Carbazole Violet Pigment 23 From India: Rescission of Administrative Review

    Science.gov (United States)

    2011-05-03

    ... Antidumping Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77988 (December 29, 2004). On January 28... order. See Initiation of Antidumping and Countervailing Duty Administrative Reviews, 76 FR 5137 (January... International Trade Administration Carbazole Violet Pigment 23 From India: Rescission of Administrative...

  17. 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?

  18. 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

  19. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Tatsuya; Yamamoto, Junichi; Fukuchi, Masashi; Kaji, Hironori, E-mail: kaji@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Hirata, Shuzo; Jung, Heo Hyo; Adachi, Chihaya [Center for Organic Photonics and Electronics Research (OPERA), Kyusyu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Hirata, Osamu; Shibano, Yuki [Nissan Chemical Industries, LTD, 722-1 Tsuboi, Funabashi 274-8507 (Japan)

    2015-08-15

    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.

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

    International Nuclear Information System (INIS)

    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

  2. The Homogentisate Pathway: a Central Catabolic Pathway Involved in the Degradation of l-Phenylalanine, l-Tyrosine, and 3-Hydroxyphenylacetate in Pseudomonas putida

    OpenAIRE

    Arias-Barrau, Elsa; Olivera, Elías R.; Luengo, José M.; Fernández, Cristina; Galán, Beatriz; García, José L.; Díaz, Eduardo; Miñambres, Baltasar

    2004-01-01

    Pseudomonas putida metabolizes Phe and Tyr through a peripheral pathway involving hydroxylation of Phe to Tyr (PhhAB), conversion of Tyr into 4-hydroxyphenylpyruvate (TyrB), and formation of homogentisate (Hpd) as the central intermediate. Homogentisate is then catabolized by a central catabolic pathway that involves three enzymes, homogentisate dioxygenase (HmgA), fumarylacetoacetate hydrolase (HmgB), and maleylacetoacetate isomerase (HmgC), finally yielding fumarate and acetoacetate. Wherea...

  3. A β-Alanine Catabolism Pathway Containing a Highly Promiscuous ω-Transaminase in the 12-Aminododecanate-Degrading Pseudomonas sp. Strain AAC

    OpenAIRE

    Wilding, Matthew; Thomas S Peat; Newman, Janet; Scott, Colin

    2016-01-01

    ABSTRACT We previously isolated the transaminase KES23458 from Pseudomonas sp. strain AAC as a promising biocatalyst for the production of 12-aminododecanoic acid, a constituent building block of nylon-12. Here, we report the subsequent characterization of this transaminase. It exhibits activity with a broad substrate range which includes α-, β-, and ω-amino acids, as well as α,ω-diamines and a number of other industrially relevant compounds. It is therefore a prospective candidate for the bi...

  4. Dibenzofuran degradation by Sphingomonas wittichii RW1 under environmental stresses

    OpenAIRE

    Coronado E.

    2013-01-01

    Sphingomonas wittichii is a gram-negative Alpha-proteobacterium, capable of degrading xenobiotic compounds such as dibenzofuran (DBF), dibenzo-p-dioxin, carbazole, 2-hydroxybiphenyl or nitro diphenyl ether herbicides. The metabolism of strain RW1 has been the subject of previous studies and a number of genes involved in DBF degradation have been characterized. It is known that RW1 posseses a unique initial DBF dioxygenase (encoded by the dxnAl gene) that catalyzes the first step in the degrad...

  5. 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.

  6. 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.

  7. 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

  8. Characterization of PhlG, a Hydrolase That Specifically Degrades the Antifungal Compound 2,4-Diacetylphloroglucinol in the Biocontrol Agent Pseudomonas fluorescens CHA0

    OpenAIRE

    Bottiglieri, Mélanie; Keel, Christoph

    2006-01-01

    The potent antimicrobial compound 2,4-diacetylphloroglucinol (DAPG) is a major determinant of biocontrol activity of plant-beneficial Pseudomonas fluorescens CHA0 against root diseases caused by fungal pathogens. The DAPG biosynthetic locus harbors the phlG gene, the function of which has not been elucidated thus far. The phlG gene is located upstream of the phlACBD biosynthetic operon, between the phlF and phlH genes which encode pathway-specific regulators. In this study, we assigned a func...

  9. Synthesis of Carbazole Alkaloids by Ring-Closing Metathesis and Ring Rearrangement-Aromatization.

    Science.gov (United States)

    Dhara, Kalyan; Mandal, Tirtha; Das, Joydeb; Dash, Jyotirmayee

    2015-12-21

    Aprocess for the assembly of carbazole alkaloids has been developed on the basis of ring-closing metathesis (RCM) and ringrearrangement-aromatization (RRA) as the key steps. This method is based on allyl Grignard addition to isatin derivatives to provide smooth access to 2,2-diallyl 3-oxindole derivatives through a 1,2-allyl shift. The diallyl derivatives were used as RCM precursors to afford a novel class of spirocyclopentene-3-oxindole derivatives, which underwent a novel RRA reaction to afford carbazole derivatives. The synthetic sequence to carbazoles was shortened by combining the RCM and RRA steps in an orthogonal tandem catalytic process. The utility of this methodology was further demonstrated by the straightforward synthesis of carbazole alkaloids, including amukonal derivative, girinimbilol, heptaphylline, and bis(2-hydroxy-3-methylcarbazole). PMID:26768698

  10. 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.

  11. Synthesis, spectroscopic, and electrochemical properties of two dyads consisted of tetrathiafulvalene and carbazole

    Institute of Scientific and Technical Information of China (English)

    Guoqiao LAI; Yibo LIU; Meijiang LI; Yongjia SHEN

    2009-01-01

    Two donor-o-acceptor molecules containing tetrathiafulvalene (TTF) and carbazole moieties were synthesized by the reaction of 9-(4-bromo-butyl)-carbazole (1) with 2,6-bis(hexylthio)-3-(2-cyanoethylthio)-7-(methylthio)-tetrathiafulvalene (2) or 2,6-bis(2-cyanoethylthio)-3,7-bis(methylthio)tetrathiafulvalene (3) in the presence of CsOH · H2O, respectively. The structures of the molecules were characterized by 1H NMR, 13C NMR, MS, and elemental analyses. They showed negligible intramolecular charge-transfer interaction in their ground states as indicated by their UV-Vis spectroscopics and cyclic voltammetry results. Compared with carbazole, their fluorescence was strongly quenched, which implied that a photo induced electron transfer (PET) interaction between TTF and carbazole moieties occurred.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Copper-Catalyzed Oxidative C-H Amination of Tetrahydrofuran with Indole/Carbazole Derivatives.

    Science.gov (United States)

    Yang, Qingjing; Choy, Pui Ying; Fu, Wai Chung; Fan, Baomin; Kwong, Fuk Yee

    2015-11-01

    A simple α-C-H amination of cyclic ether with indole/carbazole derivatives has been accomplished by employing copper(II) chloride/bipy as the catalyst system. In the presence of the di-tert-butyl peroxide oxidant, cyclic ethers such as tetrahydrofuran, 1,4-dioxane, and tetrahydropyran successfully undergo C-H/N-H cross dehydrogenative coupling (CDC) with various carbazole or indole derivatives in good-to-excellent yields. PMID:26485515

  19. [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.

  20. 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.

  1. 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%.

  2. 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.

  3. 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. PMID:26961967

  4. 4-Fluoro-N-methyl-N-(1,2,3,4-tetra-hydro-carbazol-3-yl)benzene-sulfonamide

    DEFF Research Database (Denmark)

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

    2009-01-01

    In the title compound, C(19)H(19)FN(2)O(2)S, the hydrogenated six-membered ring of the carbazole unit adopts a half-chair conformation and the plane of the fluoro-phenyl ring forms a dihedral angle of 41.5 (1)° with respect to the carbazole mean plane. The crystal structure is segregated into lay...

  5. 75 FR 26716 - Carbazole Violet Pigment 23 from India: Extension of Time Limit for Final Results of...

    Science.gov (United States)

    2010-05-12

    ... FR 977 (January 7, 2010). This administrative review covers the period January 1, 2007 through... International Trade Administration Carbazole Violet Pigment 23 from India: Extension of Time Limit for Final... administrative review of the countervailing duty order on carbazole violet pigment 23 (CVP-23) from India....

  6. 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.

  7. Fluorescence excitation spectra of jet-cooled complexes of carbazole and mono-atomic alcohols

    International Nuclear Information System (INIS)

    Fluorescence excitation spectra of jet-cooled complexes of carbazole and one molecule of methyl, deuterated methyl, ethyl and propyl (propanol-1 and propanol-2) alcohols are analyzed. Shifts of the fluorescence excitation spectra of complexes relative to the frequency of a pure electron transition of unbound carbazole are determined. They are formed owing to the hydrogen bonds of the N-H groups of carbazole with the OH-group of alcohols. The frequencies of stretching vibrations of hydrogen groups with various alcohols vary within the range 150-157 cm-1, whereas for the deformation ones the frequencies fall in the interval 21-22.9 cm-1. The belonging of complexes to rotational conformers is determined through the shape of the rotational contours of bands of their pure electronic and electron-vibration transitions. Equilibrium configurations of complexes in the ground state are calculated (authors)

  8. 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.

  9. Biodegradation Of 4-Chlorobiphenyl By Pseudomonas synxantha

    Directory of Open Access Journals (Sweden)

    Dhanjal Noorpreet Inder Kaur

    2014-10-01

    Full Text Available The stabilization and disposal of polychlorinated biphenyls (PCBs from soil environment and wetland areas is of great concern for health and safety. Wetland remediation with microorganisms is an approach for treating PCBs. A bacterial strain was isolated from hydrocarbon contaminated soil of Ropar, Punjab, able to degrade PCBs under aerobic conditions. The percentage of degradation with 100 mM/ml of 4-chlorobiphenyl was up to 90%. Degradation was monitored by mass spectrometry, high performance liquid chromatography and spectrophotometrically, showing that 4-chlorobiphenyl was degraded almost completely. The bacterial strain was identified as Pseudomonas synxantha by 16sRNA sequencing method. This is the first report of 4-chlorobiphenyl degradation by Pseudomonas synxantha.

  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. 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.

  13. 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.

  14. The taxonomy of Pseudomonas fluorescens and Pseudomonas putida: current status and need for revision

    OpenAIRE

    Bossis, Emmanuel; Lemanceau, Philippe; Latour, Xavier; Gardan, Louis

    2000-01-01

    International audience Many studies are devoted to the ecology of Pseudomonas fluorescens and Pseudomonas putida. Indeed, bacteria belonging to these species could potentially be used for environmental purposes. Some strains are able to improve plant growth and plant health, and consequently could contribute to reduce the use of chemical inputs in agriculture. Others are able to dissimilate nitrates and to degrade xenobiotic compounds. Accurate identification of the bacterial strains teste...

  15. 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.

  16. 75 FR 25209 - Carbazole Violet Pigment 23 from India: Rescission of Administrative Review

    Science.gov (United States)

    2010-05-07

    ... in Part, and Deferral of Initiation of Administrative Review, 75 FR 4770 (January 29, 2010... Review, 75 FR 10759 (March 9, 2010). In this notice we indicated that we would be conducting the changed... International Trade Administration A-533-838 Carbazole Violet Pigment 23 from India: Rescission...

  17. 75 FR 977 - Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing Duty Administrative...

    Science.gov (United States)

    2010-01-07

    ... Pigment 23 from India, 69 FR 77995 (December 29, 2004) (CVP-23 Order). On December 1, 2008, the Department... Pigment 23 from India, 69 FR 67321 (November 17, 2004), and accompanying Issues and Decision Memorandum... Affirmative Countervailing Duty Determination: Carbazole Violet Pigment 23 From India, 69 FR at 67321....

  18. 75 FR 33243 - Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty Administrative Review

    Science.gov (United States)

    2010-06-11

    ... India: Preliminary Results of Countervailing Duty Administrative Review, 75 FR 977 (January 7, 2010... Administrative Review, 75 FR 26716 (May 12, 2010). Scope of the Order The merchandise covered by this order is... International Trade Administration Carbazole Violet Pigment 23 From India: Final Results of Countervailing...

  19. 75 FR 38076 - Carbazole Violet Pigment 23 from India: Final Results of Antidumping Duty Administrative Review

    Science.gov (United States)

    2010-07-01

    ... Pigment 23 from India: Preliminary Results of Antidumping Duty Administrative Review, 74 FR 68038... Value and Antidumping Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77988 (December 29, 2004...: Assessment of Antidumping Duties, 68 FR 23954 (May 6, 2003). The Department intends to issue...

  20. Gold-Catalyzed Direct Assembly of Aryl-Annulated Carbazoles from 2-Alkynyl Arylazides and Alkynes.

    Science.gov (United States)

    Li, Nan; Lian, Xiao-Lei; Li, Yu-Hui; Wang, Tian-Yi; Han, Zhi-Yong; Zhang, Liming; Gong, Liu-Zhu

    2016-09-01

    An unprecedented gold-catalyzed synthetic method for the direct assembly of aryl-annulated carbazoles from 2-alkynyl arylazides and alkynes is described. The reaction is proposed to proceed via a sequential cyclopropenation and intramolecular metal carbene/arene Friedel-Crafts-type reaction, respectively, mediated by two gold carbene intermediates. PMID:27529360

  1. 75 FR 27815 - Carbazole Violet Pigment 23 From China and India; Determinations

    Science.gov (United States)

    2010-05-18

    ... (74 FR 56663) and determined on February 5, 2010 that it would conduct expedited reviews (75 FR 14468... China and India; Determinations On the basis of the record \\1\\ developed in the subject five-year... on carbazole violet pigment 23 from India would be likely to lead to continuation or recurrence...

  2. 75 FR 34699 - Carbazole Violet Pigment 23 from India: Rescission of Countervailing Duty Administrative Review

    Science.gov (United States)

    2010-06-18

    ... Investigation; Opportunity To Request Administrative Review, 74 FR 62743 (December 1, 2009). On December 31... Initiation of Administrative Review, 75 FR 4770 (January 29, 2010). Rescission of Countervailing Duty... International Trade Administration Carbazole Violet Pigment 23 from India: Rescission of Countervailing...

  3. Draft Genome Sequence of Pseudomonas stutzeri ODKF13, Isolated from Farmland Soil in Alvin, Texas

    OpenAIRE

    Iyer, Rupa; Damania, Ashish

    2016-01-01

    Pseudomonas stutzeri ODKF13 is a bacterial microorganism isolated from farmland soil in Alvin, Texas. This strain is notable for its naphthalene degradation and nitrogen fixation pathways and for its characterization as an organophosphate degrader of phosphotriester and phosphorothioate insecticides.

  4. 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. PMID:26837064

  5. 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.

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

    International Nuclear Information System (INIS)

    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

  7. Molecular Recognition of the Antiretroviral Drug Abacavir: Towards the Development of a Novel Carbazole-Based Fluorosensor

    OpenAIRE

    Idzik, Krzysztof Ryszard; Cywinski, Piotr J.; Cranfield, Charles G.; Mohr, Gerhard J.; Beckert, Rainer

    2011-01-01

    Due to their optical and electro-conductive attributes, carbazole derivatives are interesting materials for a large range of biosensor applications. In this study, we present the synthesis routes and fluorescence evaluation of newly designed carbazole fluorosensors that, by modification with uracil, have a special affinity for antiretroviral drugs via either Watson–Crick or Hoogsteen base pairing. To an N-octylcarbazole-uracil compound, four different groups were attached, namely thiophene, f...

  8. Medium and Conditions of Culture of Pseudomonas sp.(DGC-2) Degrading Cholesterol%降解胆固醇的假单胞菌DGC-2的发酵培养基和培养条件

    Institute of Scientific and Technical Information of China (English)

    王宇; 魏帅印; 龚艳秋; 吴洪槟; 刘松鑫; 刘文全; 任一兵; 李勇; 赵牧; 韦会平; 郑秋翔

    2012-01-01

    从动物粪便样品中分离出一株胆固醇氧化酶活力较高的DGC-2菌株,经鉴定为假单胞茵.利用单因子实验和正交试验对DGC-2菌株产胆固醇氧化酶摇瓶发酵的培养基及培养条件进行优化.其产酶的最适培养基为:蔗糖5 g/L,酵母粉3 g/L,牛肉膏1 g/L,吐温-80 1 g/L,胆固醇1 g/L,NH4NO3 1 g/L,KH2PO4 0.25g/L,MgSO4· 7H2O 0.25 g/L,FeSO4 0.001 g/L;最适培养条件为:初始pH6.5,接种量8.0%(v/v),32℃培养50 h.在最适培养基及最适培养条件下,胆固醇氧化酶的活力可达到712 U/L.%The bacteria strain (DGC-2) with high level of COD was isolated from animal intestines and identified as pseudomonas sp. The shake flask fermentation condition and medium of strain ( DGC-2) producing cholesterol oxi-dase was optimized by single factor and orthogonal experiment. The optimum medium of culture with the highest enzyme activity included the following (g/L) : sucrose 5.0, yeast extract 3.0, beaf extract 1.0, Triton-80 1.0, cholesterol 1.0, NH4NO3 1.0, KH2PO4 0.25, MgSO4·7H2O 0.25, FeSO4 0.001. The optimum of conditions of culture included the following: initial pH was 6. 5 ,the inoculums volume was 8% (v/v) ,temperature was 32 ℃ for 50 h. Under the optimized cultivation conditions, the specific activity can reach 712 U/L. The productions of enzyme were markedly increased after optimization, which in turn facilitated the degradation of cholesterol. It is of benefit to the application research.

  9. Glyphosate catabolism by Pseudomonas sp

    International Nuclear Information System (INIS)

    The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing [3-14C] glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO2. Fractionation of stationary phase cells labeled with [3-14C]glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling of PG2982 cells with [3-14C]glyphosate revealed that [3-14C]sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates

  10. Crystal structure of dimethyl 9H-carbazole-2,7-di-carb-oxy-late.

    Science.gov (United States)

    Lehane, Ryan L; Golen, James A; Rheingold, Arnold L; Manke, David R

    2015-10-01

    In the title compound, C16H13NO4, the carbazole ring system is almost planar with non-H atoms possessing a mean deviation from planarity of 0.037 Å. The two ester groups are orientated trans to one another and tilted slightly from the mean plane of the carbazole ring system, making dihedral angles of 8.12 (6) and 8.21 (5)°. In the crystal, mol-ecules are linked by pairs of N-H⋯O hydrogen bonds forming inversion dimers. The dimers are linked by parallel slipped π-π inter-actions, forming slabs propagating along the b-axis direction [inter-centroid distance = 3.6042 (8) Å, inter-planar distance = 3.3437 (5) Å, slippage = 1.345 Å]. PMID:26594478

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Ruthenium(II) dendrimers containing carbazole-based chromophores as branches

    OpenAIRE

    McClenaghan, ND; Passalacqua, R; Loiseau, F; Campagna, S; Verheyde, B; Hameurlaine, Ahmed; Dehaen, Wim

    2003-01-01

    Three new luminescent and redox-active Ru(II) complexes containing novel dendritic polypyridine ligands have been synthesized, and their absorption spectra, luminescence properties (both at room temperature in fluid solution and at 77 K in rigid matrix), and redox behavior have been investigated. The dendritic ligands are made of 1,10-phenanthroline coordinating subunits and of carbazole groups as branching sites, The first and second generation species of this novel class of dendritic ligand...

  16. 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.

  17. Synthesis and characterization of poly(carbazole ethyl methacrylate) and its electrodeposition on ITO

    International Nuclear Information System (INIS)

    Poly(ethyl methacrylate) functionalized with pendant carbazole moieties was synthesized via reversible addition fragmentation chain-transfer (RAFT) polymerization. Structural characteristics of the homopolymers were studies using Fourier-transform Infrared (FT-IR) and proton nuclear magnetic resonance (“1H-NMR). Gel permeation chromatography (GPC) was utilized to determine the molecular weight and showed an average of 27,000 g/mol. To determine the carbazole pendants of poly(ethyl methacrylate), cylic voltammetry was employed. This was done by sweeping the potential across the three electrode system form 0-1.4V with indium tin oxide (ITO) coated glass slide serving as the working electrode. The structure and optical characteristics of the electrodeposited polycarbazole film were then observed using UV-Vis and FT-IR spectroscopy, respectively. Scanning electron microscopy (SEM) was used to investigate the surface morphology of the film while its thickness was measured using spectroscopic ellipsometry. Atomic force microscopy (AFM) was also employed to determine the surface roughness and topography of the film. Investigation of the characteristics of electropolymerized carbazole film may lead to interesting electrochromic properties, alternative materials in electro-optical devices and may have potential application in organic photovoltaic devices (OPVs). (author)

  18. 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.

  19. 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.

  20. 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.

  1. Pseudomonas aeruginosa in Healthcare Settings

    Science.gov (United States)

    ... CDC.gov . Healthcare-associated Infections (HAIs) Share Compartir Pseudomonas aeruginosa in Healthcare Settings On this Page What ... and/or help treat infections? What is a Pseudomonas infection? Pseudomonas infection is caused by strains of ...

  2. 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.

  3. 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

  4. 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; Kato, Takehito; Wang, Yang; Mori, Takehiko; Michinobu, Tsuyoshi

    2016-01-01

    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

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

    OpenAIRE

    Roy, Abhjit Sarma; Baruah, Reshita; Gogoi, Dhrubajyoti; Borah, Maina; Singh, Anil Kumar; Deka Boruah, Hari Prasanna

    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.

  6. 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.

  7. Synthese von TiO2-Nanopartikeln und Carbazol-Farbstoffderivaten für optische Anwendungen in anorganisch-organischen Hybridpolymeren

    OpenAIRE

    Rettenmaier, Jürgen

    2002-01-01

    Die Arbeit hatte das Ziel, Beiträge zur Synthese photorefraktiver Nanokomposite durch die geschickte Kombination spezieller organischer Farbstoffe mit elektronenleitenden, anorganischen Nanopartikeln oder mit lochleitenden Carbazol-Derivaten in hybriden Polymeren zu leisten. Dabei wurden grundlegende Erkenntnisse auf folgenden Gebieten erzielt: > TiO2-Nanopartikel als anorganische Elektronenleiter > Carbazol-Derivate als organische Lochleiter > Metallkomplex-Farbstoffe als Photosensibilisator...

  8. 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.

  9. Recombineering Pseudomonas syringae

    Science.gov (United States)

    Here we report the identification of functions that promote genomic recombination of linear DNA introduced into Pseudomonas cells by electroporation. The genes encoding these functions were identified in Pseudomonas syringae pv. syringae B728a based on similarity to the lambda Red Exo/Beta and RecE...

  10. 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.

  11. Airway epithelial cell tolerance to Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Verghese Margrith W

    2005-04-01

    Full Text Available Abstract Background The respiratory tract epithelium is a critical environmental interface that regulates inflammation. In chronic infectious airway diseases, pathogens may permanently colonize normally sterile luminal environments. Host-pathogen interactions determine the intensity of inflammation and thus, rates of tissue injury. Although many cells become refractory to stimulation by pathogen products, it is unknown whether the airway epithelium becomes either tolerant or hypersensitive in the setting of chronic infection. Our goals were to characterize the response of well-differentiated primary human tracheobronchial epithelial cells to Pseudomonas aeruginosa, to understand whether repeated exposure induced tolerance and, if so, to explore the mechanism(s. Methods The apical surface of well-differentiated primary human tracheobronchial epithelial cell cultures was repetitively challenged with Pseudomonas aeruginosa culture filtrates or the bacterial media control. Toxicity, cytokine production, signal transduction events and specific effects of dominant negative forms of signaling molecules were examined. Additional experiments included using IL-1β and TNFα as challenge agents, and performing comparative studies with a novel airway epithelial cell line. Results An initial challenge of the apical surface of polarized human airway epithelial cells with Pseudomonas aeruginosa culture filtrates induced phosphorylation of IRAK1, JNK, p38, and ERK, caused degradation of IκBα, generation of NF-κB and AP-1 transcription factor activity, and resulted in IL-8 secretion, consistent with activation of the Toll-like receptor signal transduction pathway. These responses were strongly attenuated following a second Pseudomonas aeruginosa, or IL-1β, but not TNFα, challenge. Tolerance was associated with decreased IRAK1 protein content and kinase activity and dominant negative IRAK1 inhibited Pseudomonas aeruginosa -stimulated NF-κB transcriptional

  12. Synthesis and characterization of aromatic and aliphatic ether bridged polymers containing carbazole moieties

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, İsmet, E-mail: kayaismet@hotmail.com; Temizkan, Kevser; Aydın, Aysel

    2013-08-01

    Graphical abstract: Novel ether bridged polymers containing carbazole moieties were synthesized via elimination of HBr. Fluorescence measurements of the polymers were performed using N,N′-dimethyl formamide solutions. The morphologic properties of the polymers were investigated by using Scanning Electron Microscopy. Thermal stabilities were determined TGA measurements. -- Highlights: • Novel ether bridged polymers containing carbazole moieties were synthesized via elimination of HBr. • Fluorescence measurements of the polymers were performed using DMF solutions. • The morphologic properties of the polymers were investigated by using Scanning Electron Microscopy. • Thermal stabilities were determined TGA measurements. -- Abstract: In this study, the polymers were synthesized ether bridged containing carbazole moieties via HBr elimination. Also, these polymers include the aliphatic chains at the different lengths and aromatic groups in their structures. However, the polymers were characterized by FT-IR, NMR and UV–vis spectroscopy, and their thermal stabilities were determined via TGA measurements. Fluorescence measurements were performed using N,N′-dimethyl formamide solutions and also, the optimization of the concentrations to obtain maximal emission intensity was investigated in N,N′-dimethyl formamide. The morphologic properties of the polymers were investigated at different particle sizes by using Scanning Electron Microscopy (SEM). Additionally, the number average molecular weight (M{sub n}), weight average molecular weight (M{sub w}) and polydispersity index (PDI) values of the polymers were determined by size exclusion chromatography (SEC) technique. Resultantly, the remarkable properties related to the fluorescence and thermal measurements of the polymers were obtained. Therefore, these polymers could be used in various application fields because of the fluorescent and thermal properties.

  13. 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.

  14. 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.

  15. Theoretical study on alkyne-linked carbazole polymers for blue-light multifunctional materials

    International Nuclear Information System (INIS)

    This paper studied poly[(3,6-di-tert-butyl-N-hexadecyl-1,8-carbazolylene) butadiynylene] (P1), butadiynylene-linked poly (3,6-carbazole) (P2) and butadiynylene-linked poly (2,7-carbazole) (P3) through the theoretical measurements with Gaussian 03 program package. To investigate the relationship between structures and properties of these multifunctional electroluminescent materials, their geometrical structures of ground and excited-states were optimized by B3LYP/6-31G (d) and CIS/6-31G (d) methods, respectively. The lowest excitation energies (Eg's), and the maximum absorption and emission wavelengths of these polymers were calculated by time-dependent density functional theory methods (TD-DFT). The important parameters for luminescent materials were also predicated including the ionization potentials (Ip's) and electron affinities (Ea's). The calculated results show that the highest-occupied molecular orbital (HOMO) energies lift about 0.27-0.49 eV compared to N,N'-bis(naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB), suggesting the significant improved hole-accepting and transporting abilities. In addition, substitution of alkyne for carbazole resulted in a narrow band gap and a red shift of both the absorption and emission peaks. Through above calculations, it is evidenced that these polymers can be considered as candidates for excellent OLEDs with good hole-creating abilities and high blue-light emission. - Highlights: → We studied poly [(3,6-di-tert-butyl-N-hexadecyl-1,8-carbazolylene) butadiynylene] by theoretical method. → The geometrical structures of ground and excited-states had been optimized by B3LYP/6-31G (d) and CIS/6-31G (d). → The relationship between structures and properties of these multifunctional electroluminescent materials had been investigated. → These molecules are excellent candidates for multifunctional OLED materials. → The substitution of alkyne for carbazole results in a narrow band gap and a red shift of both the

  16. 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.

  17. 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.

  18. Second harmonic generation spectroscopy of p-cresol and carbazole on SiO 2 surfaces

    Science.gov (United States)

    van Wyck, N. E.; Koenig, E. W.; Byers, J. D.; Hetherington, W. M., III

    1985-11-01

    Surface second harmonic generation (SHG) has been developed as a surface specific type of electronic spectroscopy. The surface second-order susceptibility χ (2) is enhanced by the adsorption of molecules, and an electronic spectrum can be generated by scanning the dye laser through the two-photon resonances of the adsorbate. The spectra of p-cresol ionically and covalently bound to SiO 2 and of carbazole covalently bound to SiO 2 have been obtained. Weakly bound molecules such as hydrogen-bonded cresol, phenol and aniline as well as pyridine are rapidly desorbed by the competitive process of two-photon absorption.

  19. 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.

  20. 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

  1. Pseudomonas Lipopeptide Biosurfactants

    DEFF Research Database (Denmark)

    Bonnichsen, Lise

    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...... microscopy. As it was found that viscosin played a role in biofilm dispersal, the timing and localization of viscosin biosynthetic gene expression was monitored using a fluorescent bioreporter construction. Overall the PhD project contributes with novel knowledge on potential application of Pseudomonas......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...

  2. Indicator For Pseudomonas Bacteria

    Science.gov (United States)

    Margalit, Ruth

    1990-01-01

    Characteristic protein extracted and detected. Natural protein marker found in Pseudomonas bacteria. Azurin, protein containing copper readily extracted, purified, and used to prepare antibodies. Possible to develop simple, fast, and accurate test for marker carried out in doctor's office.

  3. Novel N-acyl-carbazole derivatives as 5-HT7R antagonists.

    Science.gov (United States)

    Kim, Youngjae; Yeom, Miyoung; Tae, Jinsung; Rhim, Hyewhon; Choo, Hyunah

    2016-03-01

    To discover a novel 5-HT7R antagonist for treatment of depression, we designed N-acyl-carbazole derivatives which were synthesized and biologically evaluated against 5-HT7R. Among total 30 compounds synthesized, four compounds 27-30 showed good binding affinities with Ki values of <100 nM. The compound 28, 1-(9H-carbazol-9-yl)-6-(4-(2-methoxyphenyl)piperazin-1-yl)hexan-1-one, showed good selectivity over other serotonin receptor subtypes and turned out to be a novel selective 5-HT7R antagonist following functional assays. The compound 28 showed moderate activity on hERG channel and good stability in microsomal stability test. The compound 28 exhibited a good pharmacokinetic profile with 67.8% oral bioavailability and good penetration to the brain. The compound 28 was also tested in in vivo depression animal model and showed antidepressant effect in the forced swimming test. Therefore, the selective 5-HT7R antagonist 28 can be considered as a good lead for discovery of novel 5-HT7R antagonists as antidepressants. PMID:26852005

  4. A combined experimental and theoretical investigation of imidazole–carbazole fluorophores

    Energy Technology Data Exchange (ETDEWEB)

    Nagarajan, N.; Velmurugan, G.; Prabhu, G.; Venuvanalingam, P.; Renganathan, R., E-mail: rrengas@gmail.com

    2014-03-15

    Two different tri and tetra substituted imidazole derivatives connected with carbazole moiety were synthesized by using Vilsmeier–Haack formylation followed by multicomponent cyclisation reaction. Results obtained from spectroscopic ({sup 1}H NMR, {sup 13}C NMR, Mass) and single crystal X-ray diffraction analysis of synthesized compound revealed its chemical structure. UV–vis and photoluminescence studies in various solvents with different polarity demonstrated that these compounds were sensitive to the polarity of the microenvironment in the excited state. Results of TGA and AFM analysis demonstrated that the compounds exhibited good thermal and morphological stabilities over very harsh conditions. DFT calculations were performed to elucidate the structural and electrochemical properties of these compounds. The computed result revealed the ground state of the molecules was majorly stabilized by σ→σ{sup ⁎} interaction and the natural hybrid orbital compositions and occupancies predict that the bonding interactions between C and N centers possess pure σ bond with sp{sup 2} hybridization. -- Highlights: • Highly fluorescent imidazole–carbazole derivatives were synthesized and characterised. • Effect of solvent polarity on absorption and emission spectra were analysed. • Thermal and morphological stabilities of the compounds were analysed. • DFT calculations have been performed to elucidate the structural properties.

  5. 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. PMID:27431786

  6. 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.

  7. 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.

  8. Molecular recognition of the antiretroviral drug abacavir: towards the development of a novel carbazole-based fluorosensor.

    Science.gov (United States)

    Idzik, Krzysztof Ryszard; Cywinski, Piotr J; Cranfield, Charles G; Mohr, Gerhard J; Beckert, Rainer

    2011-05-01

    Due to their optical and electro-conductive attributes, carbazole derivatives are interesting materials for a large range of biosensor applications. In this study, we present the synthesis routes and fluorescence evaluation of newly designed carbazole fluorosensors that, by modification with uracil, have a special affinity for antiretroviral drugs via either Watson-Crick or Hoogsteen base pairing. To an N-octylcarbazole-uracil compound, four different groups were attached, namely thiophene, furane, ethylenedioxythiophene, and another uracil; yielding four different derivatives. Photophysical properties of these newly obtained derivatives are described, as are their interactions with the reverse transcriptase inhibitors such as abacavir, zidovudine, lamivudine and didanosine. The influence of each analyte on biosensor fluorescence was assessed on the basis of the Stern-Volmer equation and represented by Stern-Volmer constants. Consequently we have demonstrated that these structures based on carbazole, with a uracil group, may be successfully incorporated into alternative carbazole derivatives to form biosensors for the molecular recognition of antiretroviral drugs. PMID:21222147

  9. 75 FR 13257 - Carbazole Violet Pigment 23 from India: Final Results of the Expedited Five-year (Sunset) Review...

    Science.gov (United States)

    2010-03-19

    ... Pigment 23 (CVP-23) ] from India pursuant to section 751(c) of the Tariff Act of 1930, as amended (the Act). See Initiation of Five-year (Sunset) Review, 74 FR 56593 (November 2, 2009) (Initiation Notice). On... International Trade Administration Carbazole Violet Pigment 23 from India: Final Results of the Expedited...

  10. 75 FR 12497 - Carbazole Violet Pigment 23 from India and the People's Republic of China: Final Results of the...

    Science.gov (United States)

    2010-03-16

    ... China, 69 FR 77987 (December 29, 2004); Notice of Amended Final Determination of Sales at Less Than Fair Value and Antidumping Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77988 (December 29, 2004... 1930, as amended (the Act). See Initiation of Five-Year (``Sunset'') Review, 74 FR 56593 (November...

  11. 75 FR 10759 - Carbazole Violet Pigment 23 from India: Initiation of Antidumping Duty Changed-Circumstances Review

    Science.gov (United States)

    2010-03-09

    ... and Antidumping Duty Order: Carbazole Violet Pigment 23 From India, 69 FR 77988 (December 29, 2004... Order, Finding, or Suspended Investigation; Opportunity To Request Administrative Review, 74 FR 62743... Revocation in Part, and Deferral of Initiation of Administrative Review, 75 FR 4770 (January 29, 2010)....

  12. 77 FR 1463 - Carbazole Violet Pigment 23 From the People's Republic of China: Final Rescission of Antidumping...

    Science.gov (United States)

    2012-01-10

    ... Duty Administrative Review, 76 FR 55003 (September 6, 2011) (Preliminary Results). DATES: Effective... People's Republic of China: Rescission of Antidumping Duty Administrative Review, 76 FR 53408 (August 26... International Trade Administration Carbazole Violet Pigment 23 From the People's Republic of China:...

  13. 75 FR 25840 - Carbazole Violet Pigment 23 from the People's Republic of China: Extension of Time Limit for the...

    Science.gov (United States)

    2010-05-10

    ... Antidumping Duty Administrative Review, 74 FR 68780 (December 29, 2009) (Preliminary Results). The final... the Tariff Act of 1930, As Amended, 70 FR 24533 (May 10, 2005). This notice is published in accordance... International Trade Administration Carbazole Violet Pigment 23 from the People's Republic of China: Extension...

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

    Science.gov (United States)

    2010-10-13

    ...-Circumstances Review, 75 FR 52930 (August 30, 2010). Although we gave interested parties an opportunity to... Antidumping Duty Administrative Review, 75 FR 38076 (July 1, 2010). Notification This notice serves as a... International Trade Administration Carbazole Violet Pigment 23 From India: Final Results of Antidumping...

  15. 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 were...

  16. Digestion of algin by Pseudomonas maltophilia and Pseudomonas putida.

    OpenAIRE

    von Riesen, V L

    1980-01-01

    Pseudomonas maltophilia and Pseudomonas putida were identified as alginolytic species. Two media used for demonstrating alginolytic activity are described. The applied aspects of the ability of these two species to digest algin are discussed.

  17. Hot Tub Rash (Pseudomonas Folliculitis)

    Science.gov (United States)

    ... clinical tools newsletter | contact Share | Hot Tub Rash ( Pseudomonas Folliculitis) Information for adults A A A This ... small pus-filled lesions. Overview Hot tub rash ( Pseudomonas folliculitis) is an infection of the hair follicle ...

  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. Degradation of Ochratoxin A by Brevibacterium Species

    OpenAIRE

    Rodriguez, Héctor; Reverón, Inés; Doria, Francesca; Costantini, Antonella; Rivas, Blanca de las; Muñoz, Rosario; García-Moruno, Emilia

    2011-01-01

    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 ¿ was detected and identified by high-performance liquid chromatographymass spectrometry (HPLC-MS) as a degradation product in the cellfree supe...

  20. 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.

  1. SYNTHESIS AND CHARACTERIZATION OF POLYMERS BEARING AZOBENZENE AND CARBAZOLE GROUPS VIA POST-AZO-COUPLING REACTION

    Institute of Scientific and Technical Information of China (English)

    Jun Shi; Zhi-wei Jiang; Li Zhang; Shao-kui Cao

    2005-01-01

    A series of polymers bearing azobenzene and carbazole groups for photorefractive purpose were prepared via post-azo-coupling reaction. The successful reaction was identified by spectroscopic analysis and gel permeation chromatography. This approach is more facile compared with the direct polymerization of corresponding functional monomer. The polymers prepared have weight average molecular weight of higher than 1.5 × 104 and are easily soluble in common organic solvents like chloroform and tetrahydrofuran, polymer films with high optical quality could be easily fabricated through solution casting. Glass transition temperature (Tg) of the polymers ranges from 60℃ to 182℃, depending on the alkylene spacer length between the functional side group and the polymer backbone, and the polymers are relatively stable under 300℃.

  2. Carbazole Containing Copolymers: Synthesis, Characterization, and Applications in Reversible Holographic Recording

    Directory of Open Access Journals (Sweden)

    Bénédicte Mailhot-Jensen

    2010-01-01

    Full Text Available Carbazolic copolymers have been developed to be used in reversible holographic recording. This paper describes a complete analysis, from synthesis of the material to its applications, together with the corresponding characterizations. The investigated materials were photosensitive copolymers obtained from carbazolylalkylmethacrylates (CEM and octylmethacrylate (OMA. A detailed investigation was undertaken involving infrared spectroscopy and NMR techniques, 1H, 13C, COSY, and HSQC, in order to establish the chemical structure and the composition of the copolymers. Holographic recording characteristics were investigated with one- and two-layer photothermoplastic carriers. The two-layer carrier contains separate photosensitive and thermoplastic layers and gives the best holographic response. The surface of microstructured samples has been characterized by atomic force microscopy analysis. It is shown that via a photothermoplastic recording process, it is possible to record and read holograms practically in real time (~3 s with a diffraction efficiency of 10% and a spatial resolution higher than 1000 mm−1.

  3. Assessing the response of degradative biofilms to groundwater pollutants

    OpenAIRE

    Keasling, Jay D.

    2002-01-01

    There is limited knowledge of interspecies interactions in biofilm communities. In this study, Pseudomonas sp. GJ1, a 2-chloroethanol (2-CE) degrading organism, and Pseudomonas putida DMP1, a p-cresol degrader, produced distinct biofilms in response to model mixed waste streams comprised of 2-CE and various p-cresol concentrations. The two organisms maintained a commensal relationship, with DMP1 mitigating the inhibitory effects of p-cresol on GJ1. A triple labeling technique compatible with ...

  4. Pseudomonas aeruginosa biofilm infections

    DEFF Research Database (Denmark)

    Tolker-Nielsen, Tim

    2014-01-01

    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...

  5. Research on the degradation characteristics of naphthalene and phenanthrene by Pseudomonas aeruginosa%铜绿假单胞菌对萘和菲降解特性研究

    Institute of Scientific and Technical Information of China (English)

    汪如婷; 雒晓芳; 田丹妮; 莫芳芳; 马麟龙

    2015-01-01

    研究不同pH和温度条件下,铜绿假单胞菌(Pseudomonas aeruginosa)对多环芳烃中萘和菲的降解效果.结果表明,以活性炭为吸附载体,多环芳烃为唯一碳源,将此菌株培养48h后,pH值为7.0时,萘的降解率可达25.68%,脱氢酶活性达到33.42 (μg/mL)·h;菲的降解率可达41.9%,脱氢酶活性达到37.44 (μg/mL)·h.当温度为37 ℃时,萘的降解率可达27.7%,脱氢酶活性达到33.60 (μg/mL)·h;菲的降解率可达34.5%,脱氢酶活性达到39.96(μg/mL)·h.

  6. 东营石油污染区微生物多样性及优势菌假单胞菌对甲苯的降解%The research of microbial diversity in Dongying petroleum contaminated zone and the degradation of toluene by advantage bacterium pseudomonas

    Institute of Scientific and Technical Information of China (English)

    张晓

    2014-01-01

    目的:随着石油及其产品对环境的污染越来越受到重视,利用土壤微生物修复方法治理石油污染土壤得到了越来越多的关注。土壤中各种微生物可以吸收、降解和转化土壤中的污染物,使污染物的浓度降低或转化为无害的物质。本实验研究了东营石油污染区微生物的多样性及假单胞菌对甲苯的降解。方法对山东东营胜利油田附近区域的土壤微生物群落通过分子生物学方法进行分析研究,用大田实验研究了假单胞菌对甲苯的降解。结果确定了不同污染程度土壤中微生物多样性的变化,证明污染程度不同的区域具有相似的优势菌群。随着污染程度变化,微生物种类有所差异。优势菌群具有良好的污染物降解能力。结论对污染区微生物多样性及菌群对有机物的降解的研究,有助于利用生物降解的方法应对有机物的污染。%Objective With more attention paid to the pollution of oil and its products to the environment,the methods using soil microorganism repair to improve petroleum contaminated soil become more and more signifi-cant.Microorganisms in the soil could absorb,degrade and transform soil pollutants,or reduce the concentration of the pollutants into harmless substance.This experiment studied the microbial diversity of Dongying oil pollution area and the degradation of toluene by pseudomonas.Methods We used molecular biology methods to study the soil microbial communities in the vicinity of the Shandong Dongying Shengli oilfield.The degradation of toluene by pseudomonas was studied by field experiment.Results We confirmed the changes of different degree of pollution in the soil microbial diversity,and the different areas have the similar advantage bacterium groups.With the chan-ges of the degree of pollution,microbial species became different.Advantage bacterium groups had good ability to degrade pollutant.Conclusion The study of microbial

  7. 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.

  8. 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.

  9. 溴氰菊酯降解菌Pseudomonas sp. P1-1-B3产酶条件的优化%Optimal Conditions on the Production of Deltamethrin-degrading Enzyme from Pseudomonas sp. P1-1-B3 Strain

    Institute of Scientific and Technical Information of China (English)

    刘丽花; 王兆守; 陈小兰; 徐敦明; 郭英霞; 邵宗泽

    2010-01-01

    农药降解酶对去除农药残留污染具有良好的应用前景.从海洋沉积物中筛选到一株高产溴氰菊酯降解酶的菌株Pseudomonas sp. P1-1-B3,研究了碳源、氮源、pH值、培养温度、培养时间、接种量及溴氰菊酯对菌株产酶的影响.结果表明,降解菌产酶的最适条件为:以可溶性淀粉作为碳源,m(蛋白胨)∶m(酵母浸膏)=2∶1为氮源,pH 7.5,温度30 ℃,培养时间2 d,接种量3%,溴氰菊酯含量15 μmol/L.在此条件下,菌株产酶的比活力最大为113.3 U/mg.该降解酶对溴氰菊酯的降解,在12 h内降解率达54.6%.

  10. 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.

  11. Performance variation from triphenylamine- to carbazole-triphenylamine-rhodaniline-3-acetic acid dyes in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Highlights: → We synthesized an organic dye of carbazole-rhodaniline-3-acetic acid-triphenylamine. → A dye-sensitized solar cell is fabricated using this dye with efficiency of 4.64%. → Carbazole donor in the dye molecule provides electron in increasing efficiency. → Two rhodaniline-3-acetic acids play a key role in increasing efficiency. → AC impedance proves this dye's effect on enhancing charge transfer in TiO2. - Abstract: Organic dyes have been synthesized which contain an extra-electron donor (carbazole) and electron acceptors (rhodaniline-3-acetic acid) on triphenylamines (TPA). Photophysical, electrochemical, and theoretical computational methods have categorized these compounds. Nanocrystalline TiO2-based dye-sensitized solar cells (DSSCs) are fabricated using these dye molecules as light-harvesting sensitizers. The overall efficiency of sensitized cells has 4.64% relative to a cis-di(thiocyanato)-bis(2,2'-bipyridyl)-4,4'-dicarboxylate ruthenium (II) (N3 dye)-sensitized device (7.83%) fabricated and measured under the same conditions. Carbazole-electron donation in the dye molecules plays a key role in the increased efficiency. Two rhodaniline-3-acetic acid groups appear to help convey the charge transfer from the excited dye molecules to the conduction band of TiO2, leading to a higher efficiency of devices using such a dye. Electrochemical impedance supports this dye's effect on enhancing charge transfer in TiO2 (e-). Computations on this dye compound also indicate the larger charge transfer efficiency in the electronically excited state.

  12. 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.

  13. 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.

  14. 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.

  15. Trichloroethylene metabolism by microorganisms that degrade aromatic compounds.

    OpenAIRE

    1988-01-01

    Trichloroethylene (TCE) was metabolized by the natural microflora of three different environmental water samples when stimulated by the addition of either toluene or phenol. Two different strains of Pseudomonas putida that degrade toluene by a pathway containing a toluene dioxygenase also metabolized TCE. A mutant of one of these strains lacking an active toluene dioxygenase could not degrade TCE, but spontaneous revertants for toluene degradation also regained TCE-degradative ability. The re...

  16. 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.

  17. 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.

  18. 恶臭假单胞菌好氧降解高氯联苯的蛋白质组分析%Proteomic analysis of aerobic degradation of highly chlorinated PCBs by Pseudomonas putida HP1

    Institute of Scientific and Technical Information of China (English)

    王呈玉; 孙玉成; 曲迪; 李成龙; 王玉军; 王继红; 胡耀辉

    2012-01-01

    The total proteins of Pseudomonas putida HP1 that use glucose and Arcolor 1260 as nutritional matrix for growth were separated respectively by immobilized pH gradient-based 2-DE.The differential expressed proteins were screened by PD Quest analysis software and identified by peptide mass fingerprint based on MOLDI-TOF-MS.Part of differential protein spots were identified in reference of the database.These results showed that a well-resolved and reproducible 2-DE pattern was obtained,and eighty differential expressed protein spots were found by comparative analysis.Fourteen differential expressed proteins were identified,including stress response proteins,proteins related to protein biosynthesis,transporter and metabolic enzymes.This suggested that the cell using PCBs as sole carbon and energy source produced stress response,and then maintained their stability,growth and metabolism by enhancing the expression of stress response proteins,proteins related to protein biosynthesis and enzymes related to metabolism.%利用固相pH梯度双向凝胶电泳分离恶臭假单胞菌以葡萄糖和Aroclor1260作为营养基质生长的菌株总蛋白,凝胶经银蓝显色后,采用PDQuest图像分析软件比较、分析识别差异表达蛋白,应用MOLDI-TOF-MS得到相应的肽质量指纹图谱,然后搜索数据库鉴定部分差异蛋白点.结果表明,获得了分辨率较高、重复性较好的不同营养基质条件下菌株蛋白的双向凝胶电泳图谱,比较分析共发现80个差异蛋白点,成功鉴定14个差异表达蛋白,包括应激应答蛋白、蛋白质生物合成、运载体和代谢相关酶类.提示与葡萄糖作为生长基质相比,菌体以多氯联苯作为碳源和能源生长时,产生应激,通过增强应激响应蛋白、蛋白质生物合成相关蛋白和相关代谢酶类的表达使细胞在胁迫条件下维持自身的稳定性与生长代谢.

  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. 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.

  1. 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.

  2. Effect of carbazole as a donor moiety on the second-order nonlinearity of organic molecules

    Science.gov (United States)

    Meshulam, Guilia; Berkovic, Garry; Kotler, Zvi; Ben-Asuly, Amos; Mazor, Royi; Shapiro, Lev; Khodorkovsky, Vladimir

    1999-10-01

    The second order nonlinearity of conjugated organic molecules involving, 1,3 indandione derivatives as an acceptor moiety has been studied. Varying the donor from dialkylamino to the chemically similar substituent, N- carbazolyl resulted in a drastic reduction of electric field induced second harmonic (beta) values. For some molecules, even a small negative value of (beta) was received. Quantum chemical calculations indicate that the decrease occurs as a result of two overlapping transitions, which contribute to (beta) with opposite signs. The charge transfer band gives a positive (beta) zzz along the molecular long axis, while a transition essentially within the carbazole moiety provides a negative (beta zzz contribution to (beta EFISH. Thus, these molecules must be described with a 2D model as opposed to the 'classical' model of 1D nonlinear optical chromophores. The prediction of the 2D model was verified experimentally by using a combination of two methods, EFISH and Hyper-Rayleigh Scattering, which probe different combination of the (beta) tensor elements.

  3. 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.

  4. Discovery of a Carbazole-Derived Lead Drug for Human African Trypanosomiasis.

    Science.gov (United States)

    Thomas, Sarah M; Purmal, Andrei; Pollastri, Michael; Mensa-Wilmot, Kojo

    2016-01-01

    The protozoan parasite Trypanosoma brucei causes the fatal illness human African trypanosomiasis (HAT). Standard of care medications currently used to treat HAT have severe limitations, and there is a need to find new chemical entities that are active against infections of T. brucei. Following a "drug repurposing" approach, we tested anti-trypanosomal effects of carbazole-derived compounds called "Curaxins". In vitro screening of 26 compounds revealed 22 with nanomolar potency against axenically cultured bloodstream trypanosomes. In a murine model of HAT, oral administration of compound 1 cured the disease. These studies established 1 as a lead for development of drugs against HAT. Pharmacological time-course studies revealed the primary effect of 1 to be concurrent inhibition of mitosis coupled with aberrant licensing of S-phase entry. Consequently, polyploid trypanosomes containing 8C equivalent of DNA per nucleus and three or four kinetoplasts were produced. These effects of 1 on the trypanosome are reminiscent of "mitotic slippage" or endoreplication observed in some other eukaryotes. PMID:27561392

  5. Inhibition of Plasmodium falciparum Hsp90 Contributes to the Antimalarial Activities of Aminoalcohol-carbazoles.

    Science.gov (United States)

    Wang, Tai; Mäser, Pascal; Picard, Didier

    2016-07-14

    Malaria caused by the protozoan parasite Plasmodium falciparum (Pf) remains a major public health problem throughout the developing world. One molecular target that should receive more attention is the molecular chaperone Hsp90. It is essential and highly conserved in all eukaryotes, including in protozoan parasites. We have identified an amino-alcohol carbazole (N-CBZ) as a PfHsp90-selective inhibitor by virtually docking a large set of antimalarial compounds, previously found in a phenotypic screen, into a PfHsp90-specific pocket. By correlating the ability of 30 additional N-CBZ derivatives to bind directly to PfHsp90 with their Pf-inhibitory activity, we found that these types of compounds are more likely to inhibit Pf growth if they bind PfHsp90. For plausible targets such as PfHsp90, our workflow may help identifying the molecular target for compounds found by screening large chemical libraries for a desired biological effect and, conversely, ensuring biological effectiveness for compounds affecting a particular target. PMID:27312008

  6. 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.

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Self-Assembly of Electron Donor-Acceptor-Based Carbazole Derivatives: Novel Fluorescent Organic Nanoprobes for Both One- and Two-Photon Cellular Imaging.

    Science.gov (United States)

    Zhang, Jinfeng; Chen, Wencheng; Kalytchuk, Sergii; Li, King Fai; Chen, Rui; Adachi, Chihaya; Chen, Zhan; Rogach, Andrey L; Zhu, Guangyu; Yu, Peter K N; Zhang, Wenjun; Cheah, Kok Wai; Zhang, Xiaohong; Lee, Chun-Sing

    2016-05-11

    In this study, we report fluorescent organic nanoprobes with intense blue, green, and orange-red emissions prepared by self-assembling three carbazole derivatives into nanorods/nanoparticles. The three compounds consist of two or four electron-donating carbazole groups linked to a central dicyanobenzene electron acceptor. Steric hindrance from the carbazole groups leads to noncoplanar 3D molecular structures favorable to fluorescence in the solid state, while the donor-acceptor structures endow the molecules with good two-photon excited emission properties. The fluorescent organic nanoprobes exhibit good water dispersibility, low cytotoxicity, superior resistance against photodegradation and photobleaching. Both one- and two-photon fluorescent imaging were shown in the A549 cell line. Two-photon fluorescence imaging with the fluorescent probes was demonstrated to be more effective in visualizing and distinguishing cellular details compared to conventional one-photon fluorescence imaging. PMID:27097920

  13. 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.

  14. 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. PMID:26875795

  15. 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

  16. Crystal structure of 3-(9H-carbazol-9-yl-N′-[(E-4-chlorobenzylidene]propanohydrazide

    Directory of Open Access Journals (Sweden)

    Mehmet Akkurt

    2015-12-01

    Full Text Available In the title compound, C22H18ClN3O, the carbazole ring system is essentially planar (r.m.s deviation = 0.003 Å, and makes a dihedral angle of 9.01 (8° with the plane of the chlorophenyl ring. In the crystal, neighbouring molecules are linked into centrosymmetric R22(8 dimers by pairs of N—H...O interactions and into a three-dimensional network by C—H...π interactions. The dimers are arranged into layers parallel to (010.

  17. [Meningoencephalitis caused by Pseudomonas cepacia].

    Science.gov (United States)

    Pérez Monrás, Miriam Fina; Batlle Almodóvar, María del Carmen; González, Cernero; Tamargo Martínez, Isis; Meneses, Félix Dickinson

    2006-01-01

    A case of meningoencephalitis of bacterial etiology caused by Pseudomonas cepacia was described. The strain was received at the Reference Laboratory of Bacterial Acute Respiratory Infections of "Pedro Kouri" Institute of Tropical Medicine, where its microbiological identification was confirmed. This isolation was a finding in an adult immunocompetent patient. The evolution was favourable with no sequelae for his future life. Pseudomona cepacia has been associated with respiratory infections in patients with cystic fibrosis. Patients with Pseudomonas cepacia may be asymptomatic or present fatal acute and fulminant infection. PMID:23427437

  18. 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.

  19. 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...

  20. The mixed carbon-nitrogen conjugation in the carbazole based polymer; the electrochemical, UVVis, EPR, and IR studies on 1,4 bis[(E)2-(9H-carbazol-9-yl)vinyl]benzene

    Energy Technology Data Exchange (ETDEWEB)

    Lapkowski, Mieczyslaw [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Centre of Polymer and Carbon Materials, Polish Academy of Science, Curie Sklodowska 34, 41-800 Zabrze (Poland); Zak, Jerzy, E-mail: jerzy.zak@polsl.p [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Karon, Krzysztof [Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Marciniec, Bogdan; Prukala, Wieslaw [Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland)

    2011-04-15

    Research highlights: {yields} This is study on conjugatively N-linked bicarbazoles. {yields} We provide electrochemical and spectral characteristics for both monomer and polymer. {yields} We found hypsochromic effect (absorbance and fluorescence) for polymer vs. monomer. {yields} The resulting polymer reveals the higher band gap than its monomer. - Abstract: We report on electronic and spectroscopic properties of a new synthesized bicarbazole monomer and its electroactive polymer. In the monomer a branching of the carbazole conjugation occurs through N-linked, conjugated bridge between two carbazole units. That extended conjugation path adds rigidity to the large molecule, which leads in electropolymerization to the formation of ordered polymeric structure. That result is supported by an evident hypsochromic shift in both the absorption and fluorescence spectra measured for the monomer and its polymer. The effect of broadening of the band gap of the created polymer demonstrates a new route in designing of monomers that may lead to stable polymeric materials emitting blue light. The ex situ IR spectra of the polymer and the course of the electropolymerization monitored using in situ IR measurements confirm the assumed structure of the obtained polymer. Electrochemical, UVVis-, and EPR-spectroelectrochemical data have been provided to discuss the properties of the system and to support the proposed reaction mechanism.

  1. Aerobic Degradation of Trichloroethylene by Co-Metabolism Using Phenol and Gasoline as Growth Substrates

    OpenAIRE

    Yan Li; Bing Li; Cui-Ping Wang; Jun-Zhao Fan; Hong-Wen Sun

    2014-01-01

    Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached ...

  2. 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.

  3. 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.

  4. Blue-shifted emission and enhanced quantum efficiency viaπ-bridge elongation in carbazole-carborane dyads.

    Science.gov (United States)

    Wang, Zhaojin; Jiang, Peng; Wang, Tianyu; Moxey, Graeme J; Cifuentes, Marie P; Zhang, Chi; Humphrey, Mark G

    2016-06-21

    Carbazole-carborane linear dyads and di(carbazole)-carborane V-shaped dyads with phenyleneethynylene-based bridges have been synthesized. The V-shaped dyads display the expected red-shifts in the location of their UV-Vis absorption maxima on bridge-lengthening, but show unusual blue-shifts in charge-transfer (CT) emission on the same π-system lengthening. These blue-shifts can be attributed to the 2n + 3 electron count within the carborane cluster in the excited state. The linear dyads luminesce via a combination of local excited (LE) and CT emission, with a red-shift in LE emission and a blue-shift in CT emission accompanying π-bridge elongation. A quantum efficiency as high as 86% in the solution state is achieved from the hybrid LE/CT emission. Time-dependent density functional theory (TD-DFT) calculations at the excited state of these compounds have clarified the photoluminescence blue-shift and suggested a typical cluster C-C bond elongation in the V-shaped dyads. Calculations on the elongated linear dyads have suggested that the electron density is localized at the phenyleneethynylene-containing bridge. PMID:27225829

  5. 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.

  6. Mineralization of Paraoxon and Its Use as a Sole C and P Source by a Rationally Designed Catabolic Pathway in Pseudomonas putida

    OpenAIRE

    de la Peña Mattozzi, Matthew; Tehara, Sundiep K.; Hong, Thomas; Keasling, Jay D.

    2006-01-01

    Organophosphate compounds, which are widely used as pesticides and chemical warfare agents, are cholinesterase inhibitors. These synthetic compounds are resistant to natural degradation and threaten the environment. We constructed a strain of Pseudomonas putida that can efficiently degrade a model organophosphate, paraoxon, and use it as a carbon, energy, and phosphorus source. This strain was engineered with the pnp operon from Pseudomonas sp. strain ENV2030, which encodes enzymes that trans...

  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. Performance characterization of a model bioreactor for the biodegradation of trichloroethylene by Pseudomonas cepacia G4.

    OpenAIRE

    Folsom, B R; Chapman, P J

    1991-01-01

    Pseudomonas cepacia G4 grown in chemostats with phenol demonstrated constant specific degradation rates for both phenol and trichloroethylene (TCE) over a range of dilution rates. Washout of cells from chemostats was evident at a dilution rate of 0.2 h-1 at 28 degrees C. Increased phenol concentrations in the nutrient feed led to increased biomass production with constant specific degradation rates for both phenol and TCE. The addition of lactate to the phenol feed led to increased biomass pr...

  9. Preferential Utilization of Aromatic Compounds over Glucose by Pseudomonas putida CSV86

    OpenAIRE

    Basu, Aditya; Apte, Shree K.; Phale, Prashant S.

    2006-01-01

    Pseudomonas putida CSV86, a naphthalene-degrading organism, exhibited diauxic growth on aromatic compounds plus glucose, with utilization of aromatics in the first log phase and of glucose in the second log phase. Glucose supplementation did not suppress the activity of degrading enzymes, which were induced upon addition of aromatic compounds. The induction was inhibited by chloramphenicol, suggesting that de novo protein synthesis was essential. Cells showed cometabolism of aromatic compound...

  10. Genome Sequence of Pseudomonas sp. HUK17, Isolated from Hexachlorocyclohexane-Contaminated Soil

    OpenAIRE

    Gasc , Cyrielle; Richard, Jean-Yves; Peyret, Pierre

    2016-01-01

    Pseudomonas sp. HUK17 has been isolated from hexachlorocyclohexane (HCH) long-term contaminated soil. The genome of strain HUK17 was sequenced to elucidate its adaptation toward HCH and to evaluate the presence of pesticide degradation pathways. Here, we report the annotated draft genome sequence (~2.6 Mbp) of this strain.

  11. 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 ( ...

  12. 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.

  13. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing, E-mail: eqgao@chem.ecnu.edu.cn

    2013-10-15

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H{sub 2}CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn{sub 5}(μ{sub 3}-OH){sub 2}(2,7-CDC){sub 4}(DEF){sub 2}] (1) (DEF=N,N-diethylformamide), [Zn{sub 2}(2,7-CDC){sub 2}(DABCO)(H{sub 2}O)]·5DMF·H{sub 2}O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn{sub 2}(2,7-CDC){sub 2}(bpea)]·3DMA·2 H{sub 2}O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle–wheel [Zn{sub 2}(COO){sub 4}] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle–wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied. - Graphical abstract: A new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid, was used to construct Zn(II) metal-organic frameworks, including a novel self-catenated network with the rare 3D alb-3,6-C2/c net and two pcu-type networks based on an unprecedented pentanuclear clusters and the common paddle–wheel units. The compounds show blue fluorescent properties. Display Omitted - Highlights: • MOFs with a new carbazole-based dicarboxylate ligand. • New pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building unit. • The rare self-catenated 3D alb-3,6-C2/c net.

  14. 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.

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

    Science.gov (United States)

    Li, Shanshan; Wang, Shan; Yan, Wei

    2016-01-01

    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. PMID:27608032

  16. 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.

  17. Spectroscopic studies on 9H-carbazole-9-(4-phenyl) boronic acid pinacol ester by DFT method

    Science.gov (United States)

    Sas, E. B.; Kurt, M.; Can, M.; Horzum, N.; Atac, A.

    2016-08-01

    9H-Carbazole-9-(4-phenyl) boronic acid pinacol ester (9-CPBAPE) molecule was investigated by FT-IR, Raman, UV-vis, 1H and 13C NMR spectra. FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. 1H, 13C NMR and UV-vis spectra were recorded in dimethyl sulfoxide (DMSO) solution. The results of theoretical calculations for the spectra of the title molecule were compared with the experimental spectra. The highest occupied molecular orbital (HOMO) the lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential (MEP) analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G (d,p) basis set calculations using the Gaussian 09 program. The total (TDOS), partial (PDOS) density of state and overlap population density of state (OPDOS) diagrams analyses were performed using GaussSum 2.2 program.

  18. 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.

  19. 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. PMID:26947457

  20. Carbazole dye with phosphonic acid anchoring groups for long-term heat stability of dye-sensitized solar cells

    International Nuclear Information System (INIS)

    In dye-sensitized solar cells (DSSCs), the binding strength between the dye and TiO2 surface may affect the heat stability of the DSSCs. Carboxylic acids have generally been used as the anchoring groups for the adsorption of dyes on TiO2 surfaces. However, a phosphonic acid anchor is expected to effect more stable bonding to a TiO2 surface because of its tridentate binding capability. In this study, we developed a new carbazole dye that employed a phosphonic acid anchor, MK-94. We studied the effect of the dye anchoring group on the heat stability of DSSCs by comparing MK-94, MK-2 (a carbazole dye with a carboxylic acid anchoring group), and Z-907 (a well-known, robust Ru complex dye with a carboxylic acid anchoring group). In the initial performance assessment, the DSSC with MK-94 exhibited a lower short circuit current (jsc) but a higher open circuit voltage (ΔVoc) than MK-2. With respect to heat stability, decreases in jsc and ΔVoc were suppressed with MK-94, and the drop of the power conversion efficiency (PCE) was kept within 6% after 504 h of heating. In addition, MK-94 demonstrated the longest electron lifetime and largest charge transfer resistance than the other dyes during the stability test. In contrast, the PCE decreased 27% from the initial value in the DSSC with MK-2. Thus, the phosphonic acid anchor was effective in extending the long-term heat stability of the DSSCs

  1. 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

  2. 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. PMID:26186726

  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. 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...

  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. 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.

  7. 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

    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...... by UV-Vis absorption, electro-chemical property studies, and computer modelling. Band gaps of 2.07 eV for P(3,6-BCBDT) and 2.23 eV for P(3,6-BCQT) were obtained. P(3,6-BCQT) afforded a power conversion efficiency of 1.44%, with a Jsc of 4.82 mA cm-2, a Voc of 0.79 V and a FF of 37%, and P(3,6-BCBDT...

  8. Influence of maturity on carbazole and benzocarbazole distributions in crude oils and source rocks from the Sonda de Campeche, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Clegg, H.; Wilkes, H.; Oldenburg, T.; Horsfield, B. [Research Centre, Juelich (Germany). Institute for Petroleum and Organic Geochemistry; Santamaria-Orozco, D. [Research Centre, Juelich (Germany). Institute for Petroleum and Organic Geochemistry]|[Instituto Mexicano del Petroleo (Mexico)

    1998-12-31

    Carbazole geochemistry has been studied for a petroleum system in which vertical migration is prominent and where reservoirs are locally sourced. An essentially uniform organofacies of organic-rich Tithonian source rocks from the Sonda de Campeche (Gulf of Mexico), covering a well defined maturity sequence (0.36-1.29% R{sub r}) and associated crude oils (0.49-0.92% R{sub c}) from Palaeocene reservoirs formed the sampling base. Comparison of the distribution of alkylcarbazoles and benzocarbazoles in rock bitumens and oils revealed that fractionation due to primary expulsion had no effect on the distribution of shielded/exposed carbazoles within crude oils. Perhaps more importantly, the benzocarbazole ratio in both extracts and crude oils increased with maturity, indicating that this parameter cannot be directly used as a migration indicator in petroleum systems where vertical migration through faults and fissures represents the main avenues of oil migration. (author)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Degradation of chlorophenols by a defined mixed microbial community.

    OpenAIRE

    E. Schmidt; Hellwig, M.; Knackmuss, H J

    1983-01-01

    Synthetic sewage containing phenol, acetone, and alkanols plus 4-chlorophenol or a mixture of isomeric chlorophenols is completely degraded by a defined mixed culture with Pseudomonas sp. strain B13 as a chlorocatechol-dissimilating member of the community. Total degradation of the organic carbon was indicated by release of stoichiometric amounts of chloride and low content of dissolved organic carbon in the cell-free effluents. During adaptation to high loads of chlorophenols the initial met...

  14. Improved Degradation of Monochlorophenols by a Constructed Strain

    OpenAIRE

    Schwien, Uwe; Schmidt, Eberhard

    1982-01-01

    Pseudomonas sp. strain B13, a strain able to degrade 3-chlorobenzoate and, after prolonged adaptation (40 days), 4-chlorophenol, could transfer the ability to degrade chlorocatechols to a recipient, Alcaligenes sp. strain A7, which is able to grow with benzoate and phenol. Representative transconjugants, such as Alcaligenes sp. strain A7-2, were able to utilize all three isomeric chlorophenols; this property was not possessed by the donor or the recipient. The ability to grow readily with 4-c...

  15. 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...

  16. Biodegradation of cytotoxic 7-Ketocholesterol by Pseudomonas aeruginosa PseA.

    Science.gov (United States)

    Ghosh, Shubhrima; Khare, S K

    2016-08-01

    The present study aims to degrade 7-Ketocholesterol (7KC), a major oxysterol implicated in many age-related disorders, through microbial means and find candidate enzymes involved for further application in food systems and as a therapeutic. During initial screening of previously isolated bacteria from our laboratory, Pseudomonas aeruginosa PseA was found to be a potential degrader strain using 7KC as a sole carbon source. Under optimized conditions, it is able to degrade 88% of an initial concentration of 1000ppm (1g/l) 7KC. Preliminary in vitro studies with extra-cellular extract has shown degradation of the compound, thus reinforcing the occurrence of suitable enzymatic systems involved in the process. We have been able to identify cholesterol oxidase as one such potential enzyme. Some intermediate products of degradation have also been identified. This is the first detailed report of 7KC degradation by a P. aeruginosa strain. PMID:27020128

  17. Substrate interactions during the biodegradation of BTEX and THF mixtures by Pseudomonas oleovorans DT4.

    Science.gov (United States)

    Zhou, Yu-Yang; Chen, Dong-Zhi; Zhu, Run-Ye; Chen, Jian-Meng

    2011-06-01

    The efficient tetrahydrofuran (THF)-degrading bacterium, Pseudomonas oleovorans DT4 was used to investigate the substrate interactions during the aerobic biotransformation of THF and BTEX mixtures. Benzene and toluene could be utilized as growth substrates by DT4, whereas cometabolism of m-xylene, p-xylene and ethylbenzene occurred with THF. In binary mixtures, THF degradation was delayed by xylene, ethylbenzene, toluene and benzene in descending order of inhibitory effects. Conversely, benzene (or toluene) degradation was greatly enhanced by THF leading to a higher degradation rate of 39.68 mg/(h g dry weight) and a shorter complete degradation time about 21 h, possibly because THF acted as an "energy generator". Additionally, the induction experiments suggested that BTEX and THF degradation was initiated by independent and inducible enzymes. The transient intermediate hydroquinone was detected in benzene biodegradation with THF while catechol in the process without THF, suggesting that P. oleovorans DT4 possessed two distinguished benzene pathways. PMID:21511464

  18. Synthesis and antiemetic activity of 1,2,3,9-tetrahydro-9-methyl-3-(4-substituted-piperazin-l-ylmethyl)-4H-carbazol-4- one derivatives

    Institute of Scientific and Technical Information of China (English)

    Qigui xu; Tianyu LIU; Rui TIAN; Qingeng LI; Deyin MA

    2009-01-01

    5-HT3 receptor antagonists, such as Ondanse-tron, are used for anti-emesis after chemotherapy, radio-therapy and operations. Some Ondansetron analogs possessing piperazine ring as side chains were synthesized in our lab. Thus, one of the two carbonyl groups of starting material 1,3-cyclohexandione (1) was condensed with phenylhydrazine hydrochloride to form monophenylhy-drazone (2). 1,2,3,9-Tetrahydro-4H-carbazol-4-one (3) was prepared from 2 via cyclization and rearranged in the presence of ZnC12. Through a methylation reaction,compound 3 was converted to 1,2,3,9-tetrahydro-9-methyl-4H-carbazol-4-one (4). 3-Dimethylaminomethyl substituted compound (5) was synthesized from 4 by a Mannich reaction in glacial acetic acid. Nine novel 1,2,3,9-t etrahydro-9-methyl- 3 - (4- sub stituted-pip erazin- 1 -ylmethyl)- 4H-carbazol-4-one derivatives (6a--6i) were sy-nthesized through nucleophilic substitution reaction of 5 with piperazines. The structures of all the target compounds were determined by elemental analysis, IR,MS, 1H NMR and 13C NMR spectra. The results of preliminary pharmacological test show that part of the novel compounds have antiemetic activity comparable to that of the control Ondansetron.

  19. Preparation of vinylogous 2-sulfonylindolines by the palladium-catalyzed heteroannulation of o-iodoanilines with dienyl sulfones and their further transformation to indoles and carbazoles.

    Science.gov (United States)

    Back, T G; Bethell, R J; Parvez, M; Taylor, J A

    2001-12-14

    The palladium-catalyzed heteroannulation of o-iodoanilines with dienyl sulfones provides a convenient route to vinylogous 2-sulfonylindolines 3. The reaction proceeds in DMF/water in the presence of potassium carbonate and catalytic palladium(II) acetate and is compatible with both electron-donating and -withdrawing substituents in the para position of the aniline, and with an alkyl substituent at C-2 of the dienyl sulfone. The indolines underwent oxidation with DDQ to afford the corresponding indoles 4. The latter were then employed as dienes in Diels-Alder reactions with dimethyl acetylenedicarboxylate (DMAD), methyl propiolate, or methyl acrylate. In the case of the latter two dienophiles, the cycloadditions were highly regioselective, affording the corresponding 1,3-products (with respect to the relative positions of the sulfone and ester groups), exclusively. The cycloadducts from acetylenic dienophiles were converted to the corresponding carbazoles by elimination of the sulfone moiety with DBU, and that from methyl acrylate was subjected to reductive desulfonylation and oxidation to the corresponding carbazole with DDQ. The method thus provides access to carbazoles with various substituents at the 3-, 4-, and 6-positions. PMID:11735543

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Phosphate taxis in Pseudomonas aeruginosa.

    OpenAIRE

    Kato, J.; Ito, A.; Nikata, T; Ohtake, H

    1992-01-01

    Pseudomonas aeruginosa was shown to be attracted to phosphate. The chemotactic response was induced by phosphate starvation. The specificity of chemoreceptors for phosphate was high so that no other tested phosphorus compounds elicited a chemotactic response as strong as that elicited by phosphate. Competition experiments showed that the chemoreceptors for phosphate appeared to be different from those for the common amino acids. Mutants constitutive for alkaline phosphatase showed the chemota...

  5. Chromium reduction in Pseudomonas putida.

    OpenAIRE

    Ishibashi, Y.; Cervantes, C; Silver, S

    1990-01-01

    Reduction of hexavalent chromium (chromate) to less-toxic trivalent chromium was studied by using cell suspensions and cell-free supernatant fluids from Pseudomonas putida PRS2000. Chromate reductase activity was associated with soluble protein and not with the membrane fraction. The crude enzyme activity was heat labile and showed a Km of 40 microM CrO4(2-). Neither sulfate nor nitrate affected chromate reduction either in vitro or with intact cells.

  6. Isolation of Endoglucanase Genes from Pseudomonas fluorescens subsp. cellulosa and a Pseudomonas sp

    OpenAIRE

    Wolff, Bruce R.; Mudry, Terry A.; Glick, Bernard R.; Pasternak, J J

    1986-01-01

    Endoglucanase genes from Pseudomonas fluorescens subsp. cellulosa and Pseudomonas sp. were cloned and characterized. DNA hybridization studies showed that these genes are homologous and that each species has one copy of the gene per genome. The DNA fragment from Pseudomonas sp. codes for, at most, a 23-kilodalton endoglucanase.

  7. 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....... We describe a 23-year-old healthy woman who developed a pustular rash and general malaise after using a spa bath contaminated with Pseudomonas aeruginosa. Bacterial culture from a pustule confirmed Pseudomonas folliculitis and the patient was treated with ciprofloxacin with rapid good effect....

  8. Complete Genome Sequence of Pseudomonas sp. UK4, a Model Organism for Studies of Functional Amyloids in Pseudomonas

    OpenAIRE

    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).

  9. 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.

  10. Acidichromism in the Mixed Langmuir-Blodgett Films of Stearic Acid with a Carbazole-containing Schiff Base

    Institute of Scientific and Technical Information of China (English)

    LIU,Yao-Hu(刘耀虎); LIU,Ming-Hua(刘鸣华)

    2002-01-01

    A new Schiff base containing carbazole group (CzSB) was synthesized. Although the compound can not form stable monolayer at air/water interface itself, it does form stable monolayers by mixing with stearic acids as verified from the surface pressure-area measurements. The mixed monolayers can be deposited by vertical dipping method. UV Spectroscopic studies of the mixed LB films reveal a broadening and red shift of the absorption spectra compared to those of CzSB in the ethanol solution, which confirms the formation of organized aggregates of the compounds in the mixed LB films. An ordered LB film was obtained as confirmed by using low-angle X-ray diffraction.The mixed LB film shows acidichromism, that is, the colors of theLB films can be reversibly changed upon exposing to HCl and NH3 gas alternatively. On the basis of FT-IR measurement, it is proposed fhat the protontatopm of the imine group in the compound is the reason for the acidichromism.

  11. 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.

  12. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    Science.gov (United States)

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-01

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H2CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn5(μ3-OH)2(2,7-CDC)4(DEF)2] (1) (DEF=N,N-diethylformamide), [Zn2(2,7-CDC)2(DABCO)(H2O)]·5DMF·H2O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn2(2,7-CDC)2(bpea)]·3DMA·2 H2O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn5(μ3-OH)2(COO)8] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle-wheel [Zn2(COO)4] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle-wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied.

  13. 9-[(E-2-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-ylethenyl]-9H-carbazole

    Directory of Open Access Journals (Sweden)

    Yuki Hatayama

    2012-01-01

    Full Text Available The title compound, C20H22BNO2, is a simple olefinic compound which carries both B and N atoms that are trans to one another. The π-conjugated system of the compound is considered to be isoelectronic with 1,3-butadiene. There are two independent molecules in the asymmetric unit in which the environments around the boron atoms are essentially planar (r.m.s. deviations of 0.0032 and 0.0021 Å for the BO2C planes. The dihedral angles of the olefinic planes with the boron planes are 5.70 (11 and 9.74 (9°, respectively, while the dihedral angles of the olefinic planes with the carbazole planes are 19.37 (3 and 10.74 (6°. These dihedral angles are consistent with those in 9-ethenylcarbazole and an ethenylboronic ester derivative. The N—Csp2, B—Csp2 and C=C bond lengths suggest that the contribution of the canonical structure can be described as N+=C—C=B−.

  14. A novel donor-acceptor polymeric electrochromic material containing carbazole and 1,8-naphtalimide as subunit

    Energy Technology Data Exchange (ETDEWEB)

    Koyuncu, Fatma Baycan, E-mail: fatmabaycan@hotmail.co [Department of Chemistry, Faculty of Sciences and Arts, Canakkale Onsekiz Mart University, 17020 Canakkale (Turkey); Koyuncu, Sermet [Can Vocational School, Canakkale Onsekiz Mart University, 17400 Canakkale (Turkey); Ozdemir, Eyup, E-mail: eozdemir@comu.edu.t [Department of Chemistry, Faculty of Sciences and Arts, Canakkale Onsekiz Mart University, 17020 Canakkale (Turkey)

    2010-07-01

    We report here the synthesis of a novel polymeric electrochromic material containing carbazole (Cbz)-donor and 1,8-napthalimide-acceptor as subunit. The band gap E{sub g} was measured using UV-vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Due to intramolecular electron transfer from Cbz-donor to 1,8-napthalimide-acceptor, the fluorescence quenching was observed. When the spectro-electrochemical and electrochromic properties of polymer film were investigated, various tones of green color were obtained on the polymeric film. In the positive regime, the polymer film obtained thereby is dark green resulting from the association of carbazolylium cation radicals at oxidized state and then it can be bleached by electrochemical reduction. Besides, in the negative regime, yellowish green color of film converted to blue attributed to reduction of the 1,8-napthalimide moiety. Finally, the polymeric electrochromic exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time.

  15. A novel donor-acceptor polymeric electrochromic material containing carbazole and 1,8-naphtalimide as subunit

    International Nuclear Information System (INIS)

    We report here the synthesis of a novel polymeric electrochromic material containing carbazole (Cbz)-donor and 1,8-napthalimide-acceptor as subunit. The band gap Eg was measured using UV-vis spectroscopy and compared with that obtained by cyclic voltammetry (CV). Due to intramolecular electron transfer from Cbz-donor to 1,8-napthalimide-acceptor, the fluorescence quenching was observed. When the spectro-electrochemical and electrochromic properties of polymer film were investigated, various tones of green color were obtained on the polymeric film. In the positive regime, the polymer film obtained thereby is dark green resulting from the association of carbazolylium cation radicals at oxidized state and then it can be bleached by electrochemical reduction. Besides, in the negative regime, yellowish green color of film converted to blue attributed to reduction of the 1,8-napthalimide moiety. Finally, the polymeric electrochromic exhibits multi-electrochromic behavior, high redox stability, high coloration efficiency and reasonable response time.

  16. 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.

  17. 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.

  18. A carbazole alkaloid deactivates mTOR through the suppression of rictor and that induces apoptosis in lung cancer cells.

    Science.gov (United States)

    Chatterjee, Priyajit; Seal, Soma; Mukherjee, Sandip; Kundu, Rakesh; Bhuyan, Mantu; Barua, Nabin C; Baruah, Pranab K; Babu, Santi Prasad Sinha; Bhattacharya, Samir

    2015-07-01

    Non-small cell lung cancer (NSCLC) is known to be a difficult cancer to treat because of its poor prognosis, limited option for surgery, and resistance to chemo or radiotherapy. In this study, we have demonstrated that suppression of rictor expression in A549 and H1299 NSCLC cells by mahanine, a carbazole alkaloid, disrupted constitutive activation of mTOR and Akt. Mahanine suppression of rictor gene expression and consequent attenuation of its protein expression affected the inhibition of mTOR (Ser-2481) and Akt (Ser-473) phosphorylation. Since mahanine treatment revealed this new insight of rictor-mTOR relationship, we examined an association between mTOR activation with rictor expression. Interestingly, in rictor knockdown (KD) NSCLC cells, mTOR activation was significantly impaired. Transfection of rictor over-expression vector into the NSCLC cells reversed this situation. In fact, both rictor KD and mahanine treated cells showed considerably depleted phospho-mTOR level. These results indicate that rictor is required to maintain constitutive activation of mTOR in lung cancer cells. When mTOR kinase activity in rictor KD cells was examined with Akt as substrate, a significant reduction of Akt phosphorylation indicated impairment of mTOR kinase potentiality. Disruption of mTOR and Akt activation caused drastic mortality of NSCLC cancer cells through apoptosis. Hence, our study reveals a new dimension in mTOR-rictor relationship, where rictor stands to be a suitable therapeutic target for lung cancer. PMID:25893736

  19. Separation and partial characterization of the enzymes of the toluene-4-monooxygenase catabolic pathway in Pseudomonas mendocina KR1.

    OpenAIRE

    Whited, G M; Gibson, D T

    1991-01-01

    The route of toluene degradation by Pseudomonas mendocina KR1 was studied by separating or purifying from toluene-grown cells the catabolic enzymes responsible for oxidation of p-cresol through the ring cleavage step. Enzymatic transformations corresponding to each of the metabolic steps in the proposed degradative pathway were conducted with cell-free preparations. p-Cresol was metabolized by the enzyme p-cresol methylhydroxylase to p-hydroxybenzaldehyde. p-Hydroxybenzaldehyde was further ox...

  20. 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.

  1. 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

  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. 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.

  4. 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.

  5. Production of Poly &beta-Hydroxybutyric Acid (PHB) by Rhizobium elti and Pseudomonas stutzeri

    OpenAIRE

    Elsayed B. Belal

    2013-01-01

    The amount of chemosynthetic plastic waste increases every year and exact time for its degradation is unknown. Two poly &beta-Hydroxybutyric producing bacteria from different microbial sources were isolated and characterized for their morphological, biochemical properties. Based on their 16S rDNA, they were identified as Rhizobium elti E1 and Pseudomonas stutzeri E114. The bacterial strains were screened for PHB production and compared for the intensity of fluorescence using Nile red staining...

  6. 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.

  7. Synthesis of Cyclo[b]fused Carbazoles via SnCl4-Mediated Domino Reaction of 2-Indolylmethylpivalates with Arenes and Heteroarenes.

    Science.gov (United States)

    Saravanan, Velu; Mageshwaran, Thiyagarajan; Mohanakrishnan, Arasambattu K

    2016-09-16

    A straightforward synthesis of aryl and heteroaryl-annulated cyclo[b]carbazoles has been developed via SnCl4-mediated one-pot arylation, cyclization and aromatization reaction sequence from 3-acetyl/aroyl-2-pivaloyloxymethylindoles. The starting material is easily accessible from commercially available 2-methylindole via Friedel-Crafts acylation, bromination and pivaloylation. Remarkably, electron withdrawing/donating aroyl units including heterocyclic systems are well tolerated in the present domino reaction protocol. Furthermore, this methodology could be extended to the synthesis of dibenzofurocarbazole via bis-annulation of 2,5-bis(2-pivaloyloxymethyl)pyrrole. PMID:27564513

  8. 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.

  9. 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.

  10. Chloroform Cometabolism by Butane-Grown CF8, Pseudomonas butanovora, and Mycobacterium vaccae JOB5 and Methane-Grown Methylosinus trichosporium OB3b

    OpenAIRE

    Hamamura, N.; Page, C.; Long, T; Semprini, L; Arp, D J

    1997-01-01

    Chloroform (CF) degradation by a butane-grown enrichment culture, CF8, was compared to that by butane-grown Pseudomonas butanovora and Mycobacterium vaccae JOB5 and to that by a known CF degrader, Methylosinus trichosporium OB3b. All three butane-grown bacteria were able to degrade CF at rates comparable to that of M. trichosporium. CF degradation by all four bacteria required O(inf2). Butane inhibited CF degradation by the butane-grown bacteria, suggesting that butane monooxygenase is respon...

  11. A study of the growth of Pseudomonas putida CP1 on mono-chlorophenols

    OpenAIRE

    Fakhruddin, A. N. M.

    2003-01-01

    Pseudomonas putida CPI grew on all three mono-chlorophenol isomers when supplied as the sole source of carbon and energy. The biodegradability of the mono-chlorophenols followed the order: 4-chlorophenol > 2-chlorophenol > 3-chlorophenol. P. putida CPI was able to degrade 300 ppm 4-chlorophenol, 250 ppm 2-chlorophenol and 200 ppm of 3-chlorophenol. In the presence of fructose (1%, w/v) the organism could degrade 400 ppm 4-chlorophenol, 500 ppm 2-chlorophenol and 300 ppm 3-chlorophenol. Ch...

  12. Cloning and sequencing of the genes involved in glyphosate utilization by Pseudomonas pseudomallei.

    OpenAIRE

    Peñaloza-Vazquez, A; Mena, G L; Herrera-Estrella, L.; Bailey, A M

    1995-01-01

    Thirty-four strains of Pseudomonas pseudomallei isolated from soil were selected for their ability to degrade the phosphonate herbicide glyphosate. All strains tested were able to grow on glyphosate as the only phosphorus source without the addition of aromatic amino acids. One of these strains, P. pseudomallei 22, showed 50% glyphosate degradation in 40 h in glyphosate medium. From a genomic library of this strain constructed in pUC19, we have isolated a plasmid carrying a 3.0-kb DNA fragmen...

  13. 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.

  14. 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.

  15. 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. PMID:23421146

  16. Synthesis and characterization of a novel multicolored electrochromic polymer based on a vinylene-linked EDOT-carbazole monomer

    International Nuclear Information System (INIS)

    A novel heterocycle-based monomer (BEDOT-V-NEtCz) is designed and synthesized using 3,4-ethylenedioxythiophene (EDOT) as the end units and 3,6-linked N-ethyl-carbazole (NEtCz) as the inner unit spaced by vinylene (V). The monomer BEDOT-V-NEtCz can be electrochemically oxidized at a very low onset potential of 0.41 V vs SCE. The resulting electroactive polymer (PBEDOT-V-NEtCz) is electrochemically synthesized by cyclic voltammetry (CV) method and its electrochromic properties are reported. Characterizations of PBEDOT-V-NEtCz film are performed by CV, scanning electron microscopy (SEM) and differential scanning calorimeter (DSC). Spectroelectrochemical analysis reveals that PBEDOT-V-NEtCz film shows multicolored electrochromism: brick-red in the reduced state, sky-blue in the oxidized state and three intermediate colors (brown at 0.2 V, olive green at 0.4 V and blue-green at 0.6 V vs SCE). The color changes are accompanied by good optical contrasts of 50% at 759 nm and 27% at 470 nm, respectively. Kinetic studies reveal that the switching time of PBEDOT-V-NEtCz film are 1.2s (759 nm) and 1.9s (470 nm) for the bleaching process and 1.4s (759 nm) and 1.8s (470 nm) for the coloration process (95% of the full ΔT%), respectively. The resultant polymer could be useful as the active layers in electrochromic devices

  17. Complete biodegradation of chlorpyrifos by engineered Pseudomonas putida cells expressing surface-immobilized laccases.

    Science.gov (United States)

    Liu, Jin; Tan, Luming; Wang, Jing; Wang, Zhiyong; Ni, Hong; Li, Lin

    2016-08-01

    The long-term abuse use of chlorpyrifos-like pesticides in agriculture and horticulture has resulted in significant soil or water contamination and a worldwide ecosystem threat. In this study, the ability of a solvent-tolerant bacterium, Pseudomonas putida MB285, with surface-displayed bacterial laccase, to biodegrade chlorpyrifos was investigated. The results of compositional analyses of the degraded products demonstrate that the engineered MB285 was capable of completely eliminating chlorpyrifos via direct biodegradation, as determined by high-performance liquid chromatography and gas chromatography-mass spectrometry assays. Two intermediate metabolites, namely 3,5,6-trichloro-2-pyridinol (TCP) and diethyl phosphate, were temporarily detectable, verifying the joint and stepwise degradation of chlorpyrifos by surface laccases and certain cellular enzymes, whereas the purified free laccase incompletely degraded chlorpyrifos into TCP. The degradation reaction can be conducted over a wide range of pH values (2-7) and temperatures (5-55 °C) without the need for Cu(2+). Bioassays using Caenorhabditis elegans as an indicator organism demonstrated that the medium was completely detoxified of chlorpyrifos by degradation. Moreover, the engineered cells exhibited a high capacity of repeated degradation and good performance in continuous degradation cycles, as well as a high capacity to degrade real effluents containing chlorpyrifos. Therefore, the developed system exhibited a high degradation capacity and performance and constitutes an improved approach to address chlorpyrifos contamination in chlorpyrifos-remediation practice. PMID:27231878

  18. Growth of Pseudomonas spp. in cottage cheese

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Dalgaard, Paw

    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...... (pH 7.0) showed interesting results. Despite a lower pH value in the cottage cheese, compared to the dressing, more rapid growth was observed. This may be caused by insufficient amounts of oxygen in the cream dressing having a negative effect on growth of Pseudomonas spp. At 15˚C growth...

  19. Transcripcional, functional and virulence analysis of a Pseudomonas Savastanoi pv. savastanoi genomic region shared with other pathogens of woody hosts

    OpenAIRE

    Caballo-Ponce, Eloy; Matas, IM; Ramos, C.

    2014-01-01

    The genome of the olive tree pathogen Pseudomonas savastanoi pv. savastanoi (Psv) NCPPB3335 (58.1% G+C) encodes a region of about 15 kb, named VR8 (60.4% G+C), which is absent in all sequenced Pseudomonas syringae strains infecting herbaceous plants, but shared with P. syringae pathovars infecting woody hosts. RT-PCR analysis of the VR8 genes revealed the existence of 4 possible operons, of which the antABC and catBCA operons are involved in the degradation of anthranilate and catechol, respe...

  20. 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.

  1. 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.

  2. Silver against Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Kirketerp-Møller, K.; Kristiansen, S.;

    2007-01-01

    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...... planktonic bacteria. These observations strongly indicate that the concentration of silver in currently available wound dressings is much too low for treatment of chronic biofilm wounds. It is suggested that clinicians and manufacturers of the said wound dressings consider whether they are treating wounds...

  3. Pseudomona pseudomallei community acquired pneumonia

    International Nuclear Information System (INIS)

    This is the first published case report en Colombia about pseudomona pseudomallei community acquired pneumonia. This uncommon pathogen is from the epidemiological standpoint a very important one and medical community should be aware to look after it in those patients where no other etiological pathogen is recovered. A brief summary about epidemiology is showed, emphasizing those regions where it can be found. Likewise, comments about the differential diagnosis are important since it should be considered in those patients where tuberculosis is suspected. This is particularly representative for countries with high tuberculosis rates. Furthermore, a microbiological review is shown, emphasizing on isolation techniques, descriptions about therapeutics and other regarding treatment issues according international standards. Finally; a description about the clinical picture, laboratory findings, treatment and evolution of the case reported are shown for discussion

  4. Utilization of fluoranthene by Pseudomonas paucimobilis strain EPA505

    International Nuclear Information System (INIS)

    Pseudomonas paucimobilis strain EPA505 was previously purified from a 7-membered bacterial community originally isolated from a creosote-contaminaated siol for its ability to degrade polycyclic aromatic hydrocarbon (PAH) components of creosote. The unique ability of this organism to utilize fluoranthene as sole source of carbon and energy for growth in pure culture was demonstrated by increase in bacterial biomass, changes in UV-absorption, decrease in aqueous fluoranthene concentration, and the production of metabolites when fluoranthene was supplied as sole carbon source in liquid culture. Compounds accumulating in fluoranthene culture medium during growth of EPA505 have been distinguished by HPLC and UV-absorption properties. Based on precedents established for bacterial degradation of similar compounds, speculative pathways aare proposed to illustrate the novel biochemistry employed by strain EPA505 in the utilization of fluoranthene. Whereas utilization of fluoranthene appears to involve previously undefined variations on established oxygenation and ring cleavage processes, these findings suggest the potential of this and other organisms for accelerating the biotransformation of other environmental pollutants currently considered recalcitrant to microbiological attack. Hence, strain EPA505 and other organisms similarly isolated for their ability to degrade fluoranthene and related compounds may prove useful to remediation efforts employing biological processes

  5. 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.

  6. 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...

  7. 咔唑比色法测定掺假蜂蜜中果胶的含量%Determination of Pectin Content in Adulteration Honey by Carbazole Colorimetry

    Institute of Scientific and Technical Information of China (English)

    任雪梅; 胡梅; 周传静; 王文特; 吴裕健

    2011-01-01

    A method for determination of pectin content in honey was established by carbazole colorimetry. The pectin was extracted by 63 % hot ethonal to remove the sugar in honey. The results showed that the top grade concentrated sulphurie acid should be used during the experience. And the ethonal, which was used to dilute carbazole, should be pured. The recovery of pectin was 88.2% ~ 94.6% with the detectable limit of 0.15 mg/kg.%建立了咔唑比色法测定蜂蜜中掺假果胶含量的方法.采用63%热乙醇溶液洗除蜂蜜中的糖分,提取试样中的果胶.结果表明,试验过程中试剂要采用优级纯浓硫酸,配制咔唑显色剂的乙醇使用前要进行精制.半乳糖醛酸的加标回收率为88.2%-94.6%,检出限为0.15 mg/kg.

  8. Indolo[3,2-b]carbazole-based multi-donor-π-acceptor type organic dyes for highly efficient dye-sensitized solar cells

    Science.gov (United States)

    Qian, Xing; Shao, Li; Li, Hongmei; Yan, Rucai; Wang, Xiaoying; Hou, Linxi

    2016-07-01

    Four novel indolo[3,2-b]carbazole-based multi-donor-π-acceptor type organic dyes QX01-04 have been designed, synthesized, and applied for dye-sensitized solar cells. These dyes consist of an indolo[3,2-b]carbazole core acting as the main donor group, a couple of groups such as ethylbenzene, N,N-diethylaniline, ethyloxylbenzene, and octyloxylbenzene acting as the secondary donors. The photophysical, electrochemical, and theoretical studies indicate that the four dyes are all capable as the photosensitizers. When introducing N,N-diethylaniline as the secondary donor, QX02 exhibits a broader absorption region and significantly improved IPCE values, which ensured a good light-harvesting ability and a high Jsc of 15.2 mA cm-2. Finally, QX02-based cell achieved a high efficiency of 8.09% which is very close to that of the commercial N719-based cell (8.26%) under 100 mW cm-2 irradiation.

  9. Synthesis and biological evaluation of novel 1,2,4-triazine derivatives bearing carbazole moiety as potent α-glucosidase inhibitors.

    Science.gov (United States)

    Wang, Guangcheng; Wang, Jing; He, Dianxiong; Li, Xin; Li, Juan; Peng, Zhiyun

    2016-06-15

    A new series of 1,2,4-triazine derivatives bearing carbazole moiety 7a-7p were designed, synthesized, and evaluated for their α-glucosidase inhibitory activity. The majority of the screened compounds displayed potent α-glucosidase inhibitory activity, with IC50 values in the range of 4.27±0.07-47.75±0.25μM as compared to the standard drug acarbose. Among the series, compound 7k represented the most potent α-glucosidase inhibitory activity with IC50 values of 4.27±0.07μM. Kinetic analysis revealed that compound 7k is a non-competitive inhibitor with a Ki of 4.43μM. Furthermore, the binding interactions of compound 7k with α-glucosidase was confirmed through molecular docking. This study showed these 1,2,4-triazine derivatives bearing carbazole moiety as a new class of α-glucosidase inhibitors. PMID:27177827

  10. Antibiotic Conditioned Growth Medium of Pseudomonas Aeruginosa

    Science.gov (United States)

    Benathen, Isaiah A.; Cazeau, Barbara; Joseph, Njeri

    2004-01-01

    A simple method to study the consequences of bacterial antibiosis after interspecific competition between microorganisms is presented. Common microorganisms are used as the test organisms and Pseudomonas aeruginosa are used as the source of the inhibitor agents.

  11. [Vasculitis caused by Pseudomonas: a case report].

    Science.gov (United States)

    Escamilla, Y; Gutiérrez, M; Martínez, T; Bodoque, M; Gómez, J M; Moreno, A

    1996-01-01

    Pseudomona vasculitis is an exceptional disease. Only a few cases have been reported, non with oropharyngeal involvement. The case of a 30-year-old, HIV-positive man who suddenly developed septicemia and necrotizing lesions with tissue destruction of the oropharynx is reported. Histological study confirmed vasculitis. Pseudomona aeruginosa was isolated in peripheral blood and in the biopsy of the palatal lesion. Antibiotic treatment produced satisfactory results. PMID:8991411

  12. Effect of cadmium ion on biodegradation of decabromodiphenyl ether (BDE-209) by Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Highlights: • BDE-209 degradation by P. aeruginosa in the presence of Cd was investigated. • Degradation was accelerated by the increase of CSH induced by low level of Cd. • Higher membrane permeability caused by low level of Cd promoted degradation. • Depression of cell growth and metabolism by high content Cd inhibited degradation. -- Abstract: The influence of Cd(II) ions on the degradation of decabromodiphenyl ether (BDE-209) by an aerobic degrading strain, Pseudomonas aeruginosa, was investigated. The results demonstrated that the strain P. aeruginosa exhibited a high level of resistance against cadmium toxicity, and Cd(II) ions of different concentrations possessed mixed reactions on BDE-209 bioremoval. The degradation efficiency was stimulated at low concentrations of Cd(II) ions (≤1 mg L−1) but inhibited at higher levels (≥5 mg L−1). Subsequent analyses revealed that the increase of cell hydrophobicity and membrane permeability were two main factors for Cd(II) ions of low concentrations to accelerate BDE-209 degradation. However, inhibition effect by high concentrations of Cd(II) ions was mainly attributed to the negative impact of metals on growth and metabolism of the strain. It was also showed through cellular distribution of BDE-209 that different concentration of Cd(II) ions affected the amount of BDE-209 inside or outside the cell at different incubation time

  13. Effect of cadmium ion on biodegradation of decabromodiphenyl ether (BDE-209) by Pseudomonas aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Guangyu [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640 (China); Yin, Hua, E-mail: huayin@scut.edu.cn [Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, College of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Ye, Jinshao [Department of Environmental Engineering, Jinan University, Guangzhou 510632 (China); Peng, Hui [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Li, Jun; Luo, Chunling [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Science, Guangzhou 510640 (China)

    2013-12-15

    Highlights: • BDE-209 degradation by P. aeruginosa in the presence of Cd was investigated. • Degradation was accelerated by the increase of CSH induced by low level of Cd. • Higher membrane permeability caused by low level of Cd promoted degradation. • Depression of cell growth and metabolism by high content Cd inhibited degradation. -- Abstract: The influence of Cd(II) ions on the degradation of decabromodiphenyl ether (BDE-209) by an aerobic degrading strain, Pseudomonas aeruginosa, was investigated. The results demonstrated that the strain P. aeruginosa exhibited a high level of resistance against cadmium toxicity, and Cd(II) ions of different concentrations possessed mixed reactions on BDE-209 bioremoval. The degradation efficiency was stimulated at low concentrations of Cd(II) ions (≤1 mg L{sup −1}) but inhibited at higher levels (≥5 mg L{sup −1}). Subsequent analyses revealed that the increase of cell hydrophobicity and membrane permeability were two main factors for Cd(II) ions of low concentrations to accelerate BDE-209 degradation. However, inhibition effect by high concentrations of Cd(II) ions was mainly attributed to the negative impact of metals on growth and metabolism of the strain. It was also showed through cellular distribution of BDE-209 that different concentration of Cd(II) ions affected the amount of BDE-209 inside or outside the cell at different incubation time.

  14. 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.

  15. 7H-dibenzo[c,g]carbazole metabolism by the mouse and human CYP1 family of enzymes.

    Science.gov (United States)

    Shertzer, Howard G; Genter, Mary B; Talaska, Glenn; Curran, Christine P; Nebert, Daniel W; Dalton, Timothy P

    2007-06-01

    Found in tobacco smoke, fossil fuel and other organic combustion products, 7H-dibenzo[c,g]carbazole (DBC) is a potent mouse lung carcinogen and potential human carcinogen. Although the first hydroxylation is critical for determining activation versus detoxication, the enzymes responsible for site-specific hydroxylation of DBC are not known. We found that DBC-DNA adduct levels are significantly higher in aromatic hydrocarbon receptor null Ahr(-/-) mice, suggesting that the induction of Aromatic hydrocarbon receptor (AHR)-regulated genes, such as those in the CYP1 family, decrease DBC genotoxicity. Using knockout mice for Cyp1a1, Cyp1a2 and Cyp1b1, we showed that the major CYP1 enzymes that metabolize DBC are CYP1A1 in beta-naphthoflavone (BNF)-induced liver, CYP1A2 in non-induced liver, CYP1B1 and CYP1A1 in induced lung and none in non-induced lung. DBC metabolism by the human CYP1 enzymes was examined in vitro using Supersomestrade mark. Each mouse CYP1, as well as each human CYP1, has a unique DBC metabolite profile. Comparison of the metabolite profile in BNF-induced mice suggested that CYP1A1 primarily generates 1-OH, 2-OH and (5 + 6)-OH-DBC, whereas CYP1A2 generates primarily (5 + 6)-OH-DBC and CYP1B1 primarily generates 4-OH-DBC. This was similar to that observed in the human CYP1 enzymes. Most importantly, lung CYP1B1 is associated with forming 4-OH-DBC, the most potent metabolite leading to DBC-DNA adducts. These studies suggest that for non-pulmonary routes of exposure (i.e. skin, gastric, i.p.), low hepatic expression of CYP1A2 and CYP1A1, together with high expression levels of lung CYP1B1 and CYP1A1, may define a phenotype for high susceptibility to carcinogens such as DBC.

  16. 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%.

  17. 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.

  18. 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...

  19. Oxidation of polychlorinated biphenyls by Pseudomonas sp. strain LB400 and Pseudomonas pseudoalcaligenes KF707.

    OpenAIRE

    Gibson, D T; Cruden, D. L.; Haddock, J D; Zylstra, G J; Brand, J M

    1993-01-01

    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 the substrate specificity of the biphenyl 2,3-dioxygenases from both organisms.

  20. 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.

  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. Microcosm experiments of oil degradation by microbial mats.

    Science.gov (United States)

    de Oteyza, Tirso García; Grimalt, Joan O; Llirós, Marc; Esteve, Isabel

    2006-03-15

    Several microcosm experiments were run in parallel to evaluate the efficiency of microbial mats for crude oil degradation as compared with physico-chemical weathering. The oils used in the experiments constituted representative examples of those currently used for commercial purposes. One was aliphatic and of low viscosity (33.4 American Petroleum Institute degrees, degrees API) and the other was predominantly aromatic, with high sulphur content (ca. 2.7%) and viscosity (16.6 degrees API). After crude oil introduction, the microcosms were kept under cyclic changes in water level to mimic coastal tidal movements. The transformations observed showed that water weathering leads to more effective and rapid elimination of low molecular weight hydrocarbons than microbial mat metabolism, e.g. n-alkanes with chain length shorter than n-pentadecane or n-heptadecane, regular isoprenoid hydrocarbons with chain length lower than C16 or C18 or lower molecular weight naphthalenes. Microbial mats preserved these hydrocarbons from volatilization and water washing. However, hydrocarbons of lower volatility such as the C24-C30 n-alkanes or containing nitrogen atoms, e.g. carbazoles, were eliminated in higher proportion by microbial mats than by water weathering. The strong differences in composition between the two oils used for the experiments were also reflected in significant differences between water weathering and microbial mat biodegradation. Higher oil viscosity seemed to hinder the former but not the later. PMID:15935450

  3. 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.

  4. Optimization of indigo production by a newly isolated Pseudomonas sp. QM.

    Science.gov (United States)

    Qu, Yuanyuan; Ma, Qiao; Zhang, Xuwang; Zhou, Hao; Li, Xinliang; Zhou, Jiti

    2012-12-01

    Optimization of indigo production process from indole using a newly isolated phenol-degrading bacterial strain was performed by Plackett-Burman design and response surface methodology. The strain designated as QM was identified as Pseudomonas sp. according to 16S rDNA analysis. Spectrum analysis of indole biotransformation products revealed the presence of indigo and a by-product indirubin. To improve indigo yield, Plackett-Burman design was used to select significant factors from 8 viriables. Then response surface methodology based on a 2(3) central composite design was used to further optimize the transformation process. Under the optimal conditons, strain QM can produce 27.20 mg/l indigo after 24 h cultivation at 30 °C, which was 151.3% higher than that from the initial conversion condition. The results indicated that Pseudomonas sp. QM should be a potential candidate for indigo industial production. PMID:22359270

  5. Physiological and Chemical Investigations into Microbial Degradation of Synthetic Poly(cis-1,4-isoprene)

    OpenAIRE

    Bode, Helge B; Zeeck, Axel; Plückhahn, Kirsten; Jendrossek, Dieter

    2000-01-01

    Streptomyces coelicolor 1A and Pseudomonas citronellolis were able to degrade synthetic high-molecular-weight poly(cis-1,4-isoprene) and vulcanized natural rubber. Growth on the polymers was poor but significantly greater than that of the nondegrading strain Streptomyces lividans 1326 (control). Measurement of the molecular weight distribution of the polymer before and after degradation showed a time-dependent increase in low-molecular-weight polymer molecules for S. coelicolor 1A and P. citr...

  6. Draft Genome Sequence of Pseudomonas putida CBF10-2, a Soil Isolate with Bioremediation Potential in Agricultural and Industrial Environmental Settings.

    Science.gov (United States)

    Iyer, Rupa; Damania, Ashish

    2016-01-01

    Pseudomonas putida CBF10-2 is a microorganism isolated from farmland soil in Fairchild, TX, found to degrade high-impact xenobiotics, including organophosphate insecticides, petroleum hydrocarbons, and both monocyclic and polycyclic aromatics. The versatility of CBF10-2 makes it useful for multipurpose bioremediation of contaminated sites in agricultural and industrial environments. PMID:27417844

  7. 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

  8. 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

  9. Biodegradation of TBP in a packed bed reactor using pseudomonas pseudoalcaligenes

    International Nuclear Information System (INIS)

    Tributyl phosphate (TBP), is an organophosphorus compound widely used as a solvent for the extraction of uranium and plutonium, from other radionuclides, in nuclear fuel processing. Several strains from contaminated sites were isolated and screened for their ability to degrade this organophosphorus compound. The most active strain identified as Pseudomonas pseudoalcaligenes could degrade 290μM of TBP and utilized it as a sole source of carbon and energy. Agarose immobilized cell systems were developed for the biodegradation of TBP. A packed bed reactor was constructed and operated for biological TBP removal. Degradation rates for repeated operations increased for successive batches indicating that cells grow better and get adapted to the reaction conditions over time. (author)

  10. 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.

    and Pseudomonas diminuta, with distinct colony traits, growth rates, and crude oil-degrading abilities (75, 74 and 60% respectively at 1% v/v concentration) were examined for changes functional role in a continuous culture system. The changes observed in the ratio...

  11. 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...

  12. 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

  13. 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.

  14. 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....

  15. White light-emitting nanocomposites based on an oxadiazole–carbazole copolymer (POC) and InP/ZnS quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, Annalisa, E-mail: annalisa.bruno@enea.it; Borriello, Carmela, E-mail: carmela.borriello@enea.it; Di Luccio, Tiziana, E-mail: tiziana.diluccio@enea.it; Nenna, Giuseppe [Centro Ricerche Portici, ENEA, UTTP NANO (Italy); Sessa, Lucia [University of Salerno, Department of Pharmacy (Italy); Concilio, Simona [University of Salerno, Department of Industrial Engineering (Italy); Haque, Saif A. [Imperial College London, Chemistry Department (United Kingdom); Minarini, Carla [Centro Ricerche Portici, ENEA, UTTP NANO (Italy)

    2013-11-15

    In this work, we studied energetic and optical proprieties of a polyester-containing oxadiazole and carbazole units that we will indicate as POC. This polymer is characterized by high photoluminescence activity in the blue region of the visible spectrum, making it suitable for the development of efficient white-emitting organic light emission devices. Moreover, POC polymer has been combined with two red emitters InP/ZnS quantum dots (QDs) to obtain nanocomposites with wide emission spectra. The two types of QDs have different absorption wavelengths: 570 nm [InP/ZnS(570)] and 627 nm [InP/ZnS(627)] and were inserted in the polymer at different concentrations. The optical properties of the nanocomposites have been investigated and compared to the ones of the pure polymer. Both spectral and time resolved fluorescence measurements show an efficient energy transfer from the polymer to QDs, resulting in white-emitting nanocomposites.

  16. 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.

  17. 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.

  18. 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.

  19. A new selective medium for isolating Pseudomonas spp. from water.

    OpenAIRE

    Krueger, C L; Sheikh, W

    1987-01-01

    A new medium, pseudomonas selective isolation agar, was developed to isolate Pseudomonas spp. from water. It consists of 350 micrograms of nitrofurantoin per ml and 2 micrograms of crystal violet per ml in a nutrient agar base. It is more selective for Pseudomonas spp. than are available commercial media. Its ingredients are inexpensive and readily available, and it is easy to prepare.

  20. 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...

  1. Pseudomonas aeruginosa quorum-sensing signal molecules interfere with dendritic cell-induced T-cell proliferation

    DEFF Research Database (Denmark)

    Skindersø, Mette Elena; Zeuthen, Louise; Pedersen, Susanne Brix;

    2009-01-01

    Pseudomonas aeruginosa releases a wide array of toxins and tissue-degrading enzymes. Production of these malicious virulence factors is controlled by interbacterial communication in a process known as quorum sensing. An increasing body of evidence reveals that the bacterial signal molecule N-(3-o......DHL and PQS thus seem to possess dual activities in the infection process: as inducers of virulence factors as well as immune-modulators facilitating the infective properties of this pathogen....

  2. 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.

  3. 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.

  4. 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.

  5. Ecofriendly biodegradation and detoxification of Reactive Red 2 textile dye by newly isolated Pseudomonas sp. SUK1

    International Nuclear Information System (INIS)

    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 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

  6. 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.

  7. [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.

  8. 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.

  9. Genome Sequences of Pseudomonas oryzihabitans Phage POR1 and Pseudomonas aeruginosa Phage PAE1

    Science.gov (United States)

    Dyson, Zoe A.; Seviour, Robert J.; Tucci, Joseph

    2016-01-01

    We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa. The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA. PMID:27313312

  10. Comparative Study for Lipase Production by Using Pseudomonas Aeruginosa and Pseudomonas Fluorescens

    OpenAIRE

    Priyam Vandana; Jyotsna Kiran Peter

    2014-01-01

    Lipases occur widely in nature, but only microbial lipases are commercially significant. The present work focuses on screening and production of extracellular laccases by Pseudomonas aeruginosa and Pseudomonas fluorescens. The lipase was assayed by tirbutyrin agar plate method and the activity of the enzyme was further confirmed by titrimetric method. The uses of lipases are enormous and increasing and so there is need to screen and isolate potential species capable of producing l...

  11. Inhibition of Pseudomonas aeruginosa elastase and Pseudomonas keratitis using a thiol-based peptide.

    OpenAIRE

    Burns, F R; Paterson, C. A.; Gray, R. D.; Wells, J T

    1990-01-01

    Pseudomonas aeruginosa elastase is a zinc metalloproteinase which is released during P. aeruginosa infections. Pseudomonas keratitis, which occurs following contact lens-induced corneal trauma, can lead to rapid, liquefactive necrosis of the cornea. This destruction has been attributed to the release of both host-derived enzymes and the bacterial products P. aeruginosa elastase, alkaline protease, exotoxin A, and lipopolysaccharide endotoxin. A synthetic metalloproteinase inhibitor, HSCH2 (DL...

  12. 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.

  13. Genome Sequence of Pseudomonas chlororaphis Strain 189

    Science.gov (United States)

    Town, Jennifer; Audy, Patrice; Boyetchko, Susan M.

    2016-01-01

    Pseudomonas chlororaphis strain 189 is a potent inhibitor of the growth of the potato pathogen Phytophthora infestans. We determined the complete, finished sequence of the 6.8-Mbp genome of this strain, consisting of a single contiguous molecule. Strain 189 is closely related to previously sequenced strains of P. chlororaphis. PMID:27340063

  14. Pseudomonas pelvic osteomyelitis in a healthy child

    Directory of Open Access Journals (Sweden)

    Nour Akhras

    2011-12-01

    Full Text Available Pediatric pelvic osteomyelitis is a rare entity. The diagnosis is frequently delayed due to difficulty in confirming the diagnosis. To our knowledge, this is the first case report of Pseudomonas pelvic osteomyelitis in a previously healthy adolescent boy. The diagnosis was made radiographically and confirmed by culture. The patient was treated with Levofloxacin and Gentamicin resulting in a complete recovery.

  15. Pseudomonas pelvic osteomyelitis in a healthy child

    OpenAIRE

    Akhras, Nour; Blackwood, Alexander

    2011-01-01

    Pediatric pelvic osteomyelitis is a rare entity. The diagnosis is frequently delayed due to difficulty in confirming the diagnosis. To our knowledge, this is the first case report of Pseudomonas pelvic osteomyelitis in a previously healthy adolescent boy. The diagnosis was made radiographically and confirmed by culture. The patient was treated with Levofloxacin and Gentamicin resulting in a complete recovery.

  16. 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...

  17. Growth and Laboratory Maintenance of Pseudomonas aeruginosa

    OpenAIRE

    LaBauve, Annette E.; Wargo, Matthew J.

    2012-01-01

    Pseudomonas aeruginosa is a common, free-living, Gram-negative bacterium that can cause significant disease as an opportunistic pathogen. Rapid growth, facile genetics, and a large suite of virulence-related phenotypes make P. aeruginosa a common model organism to study Gram-negative opportunistic pathogens and basic microbiology. This unit describes the basic laboratory growth and maintenance of P. aeruginosa.

  18. 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...

  19. 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

  20. 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.

  1. 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.

  2. Biodegradation of 2,4,5-trichlorophenoxyacetic acid by a pure culture of Pseudomonas cepacia.

    OpenAIRE

    Kilbane, J J; Chatterjee, D K; Karns, J S; Kellogg, S T; Chakrabarty, A M

    1982-01-01

    A pure culture of Pseudomonas cepacia, designated AC1100, that can utilize 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as its sole source of carbon and energy was isolated. An actively growing culture of AC1100 was able to degrade more than 97% of 2,4,5-T, present at 1 mg/ml, within 6 days as determined by chloride release, gas chromatographic, and spectrophotometric analyses. The ability of AC1100 to oxidize a variety of chlorophenols and related compounds is also reported.

  3. Molecular characterization of the mde operon involved in L-methionine catabolism of Pseudomonas putida.

    OpenAIRE

    H. Inoue; Inagaki, K.; Eriguchi, S I; Tamura, T.; Esaki, N; Soda, K; Tanaka, H.

    1997-01-01

    A 15-kb region of Pseudomonas putida chromosomal DNA containing the mde operon and an upstream regulatory gene (mdeR) has been cloned and sequenced. The mde operon contains two structural genes involved in L-methionine degradative metabolism: the already-identified mdeA, which encodes L-methionine gamma-lyase (H. Inoue, K. Inagaki, M. Sugimoto, N. Esaki, K. Soda, and H. Tanaka. J. Biochem. (Tokyo) 117:1120-1125, 1995), and mdeB, which encodes a homologous protein to the homodimeric-type E1 co...

  4. Synthesis and luminescent properties of star-burst D-π-A compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zheng [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Liu, Rui, E-mail: rui.liu@njtech.edu.cn [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Zhu, Xiaolin [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Li, Yuhao [Department of Chemistry, Fudan University, 220 Handan Road, Shanghai 200433 (China); Chang, Jin [Queensland University of Technology, 2 George St., Brisbane 4000 (Australia); Zhu, Hongjun, E-mail: zhuhjnjut@hotmail.com [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China); Ma, Liangwei; Lv, Wangjie; Guo, Jun [Department of Applied Chemistry, Nanjing Tech University, Nanjing 210009 (China)

    2014-12-15

    Two new star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms (1a and 1b) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both compounds exhibit strong {sup 1}π–π{sup ⁎} transitions in the UV region and intense {sup 1}π–π{sup ⁎}/intramolecular charge transfer ({sup 1}ICT) absorption bands in the UV–vis region. Introducing the carbazole end-capped phenylene ethynylene arm on the 1,3,5-triazine core causes a slight bathochromic shift and enhanced molar extinction coefficient of the {sup 1}π–π{sup ⁎}/{sup 1}ICT transition band. Both compounds are emissive in solution at room temperature and 77 K, which exhibit pronounced positive solvatochromic effect. The emitting state could be ascribed to {sup 1}ICT state in more polar solvent, and {sup 1}π–π{sup ⁎} state in low-polarity solvent. The high emission quantum yields (Φ{sub em}=0.90∼1.0) of 1a and 1b (in hexane and toluene) make them potential candidates as efficient light-emitting materials. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these compounds can be tuned by the carbazole end-capped phenylene ethynylene arm, which would also be useful for rational design of photofunctional materials. - Highlights: • Star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms. • Photophysical properties of target compounds were investigated systematically via spectroscopic and theoretical methods. • The relatively high fluorescence quantum yields make them potential candidates as light-emitting materials.

  5. Discovery of a Neuroprotective Chemical, (S)-N-(3-(3,6-Dibromo-9H-carbazol-9-yl)-2-fluoropropyl)-6-methoxypyridin-2-amine [(−)-P7C3-S243], with Improved Druglike Properties

    OpenAIRE

    Naidoo, Jacinth; De Jesus-Cortes, Hector; Huntington, Paula; Estill, Sandi; Morlock, Lorraine K.; Starwalt, Ruth; Mangano, Thomas J.; Williams, Noelle S.; Pieper, Andrew A.; Ready, Joseph M.

    2014-01-01

    (−)-P7C3-S243 is a neuroprotective aminopropyl carbazole with improved druglike properties compared with previously reported compounds in the P7C3 class. It protects developing neurons in a mouse model of hippocampal neurogenesis and protects mature neurons within the substantia nigra in a mouse model of Parkinson’s disease. A short, enantioselective synthesis provides the neuroprotective agent in optically pure form. It is nontoxic, orally bioavailable, metabolically stable, and able to cros...

  6. Synthesis and luminescent properties of star-burst D-π-A compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms

    International Nuclear Information System (INIS)

    Two new star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms (1a and 1b) were synthesized and characterized. Their photophysical properties were investigated systematically via spectroscopic and theoretical methods. Both compounds exhibit strong 1π–π⁎ transitions in the UV region and intense 1π–π⁎/intramolecular charge transfer (1ICT) absorption bands in the UV–vis region. Introducing the carbazole end-capped phenylene ethynylene arm on the 1,3,5-triazine core causes a slight bathochromic shift and enhanced molar extinction coefficient of the 1π–π⁎/1ICT transition band. Both compounds are emissive in solution at room temperature and 77 K, which exhibit pronounced positive solvatochromic effect. The emitting state could be ascribed to 1ICT state in more polar solvent, and 1π–π⁎ state in low-polarity solvent. The high emission quantum yields (Φem=0.90∼1.0) of 1a and 1b (in hexane and toluene) make them potential candidates as efficient light-emitting materials. The spectroscopic studies and theoretical calculations indicate that the photophysical properties of these compounds can be tuned by the carbazole end-capped phenylene ethynylene arm, which would also be useful for rational design of photofunctional materials. - Highlights: • Star-burst compounds based on 1,3,5-triazine core and carbazole end-capped phenylene ethynylene arms. • Photophysical properties of target compounds were investigated systematically via spectroscopic and theoretical methods. • The relatively high fluorescence quantum yields make them potential candidates as light-emitting materials

  7. 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

  8. Insights into the genetic diversity of initial dioxygenases from PAH-degrading bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Moser, R.; Stahl, U. [Technische Univ. Berlin, Inst. fuer Biotechnologie, Mikrobiologie und Genetik, Berlin (Germany)

    2001-07-01

    Alpha subunit genes of initial polyaromatic hydrocarbon (PAH) dioxygenases were used as targets for the PCR detection of PAH-degrading strains of the genera Pseudomonas, Comamonas and Rhodococcus which were obtained from activated sludge or soil samples. Sequence analysis of PCR products from several Pseudomonas strains showed that alpha subunits (nahAc allele) of this genus are highly conserved. PCR primers for the specific detection of alpha subunit genes of initial PAH dioxygenases from Pseudomonas strains were not suitable for detecting the corresponding genes from the genera Comamonas and Rhodococcus. Southern analysis using a heterologous gene probe derived from the P. putida OUS82 PAH dioxygenase alpha subunit identified segments of the PAH-degradation gene cluster from C. testosteroni strain H. Parts of this gene cluster containing three subunits of the initial PAH dioxygenase were isolated. These three subunits [ferredoxin (pahAb), alpha (pahAc) and beta (pahAd) subunit] were amplified by PCR as one fragment and expressed in Escherichia coli DH5{alpha}, resulting in an active initial dioxygenase with the ability to transform indole and phenanthrene. The DNA sequence alignment of alpha subunits from C. testosteroni H and various PAH-degrading bacteria permitted the design of new primers and oligonucleotide probes which are useful for the detection of the initial PAH dioxygenases from strains of Pseudomonas, Comamonas and Rhodococcus. (orig.)

  9. 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.

  10. 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.

  11. 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

    2016-01-01

    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. PMID:27000525

  12. Studies of Europium(III)/NTA uptake by the pseudomonas bacterium

    International Nuclear Information System (INIS)

    One area of nuclear waste remediation that has not yet been fully explored is the use of microorganisms to stabilize and recover radionuclides and to degrade the organic component of nuclear wastes to innocuous products. The mechanisms whereby microorganisms immobilize radionuclides are not well understood. A key question to answer is whether or not lanthanides and actinides are actually metabolized or simply adsorbed on the cell membrane. Previously, it has been demonstrated that the Pseudomonas sp. bacterium is capable of surviving in a growth medium in which NTA (nitriloacetic acid) is the only source of carbon or nitrogen. Pseudomonas has been shown to metabolize NTA and complexes such as Fe(III)-NTA and Ca-NTA. The authors have initiated a similar study to examine the metabolic effects of a growth solution containing only NTA and the Eu(III)-NTA complex on a culture of Pseudomonas. A europium radiotracer placed in the growth solution is used to investigate the accumulation of Eu(III) by the bacteria

  13. 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.

  14. 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

  15. 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.

  16. Studies on the transformation of selected polychlorinated biphenyl congeners by Pseudomonas strain LB 400

    International Nuclear Information System (INIS)

    Some of the main factors influencing the degradation of certain PCB congeners by resting cells of Pseudomonas strain LB 400 were characterized. The significance of the carbon source used for growth was studied by comparison of rates of PCB transformation by cells grown on biphenyl and other carbon sources. PCB transformation was studied in resting cells grown on glucose and glycerol. Supplementation of the degradation medium with biphenyl significantly decreased the rate of PCB congener transformation. The presence of glycerol or glucose did not affect PCB transformation rates. The study showed that in the treatment of contaminated soils, resting cells lose their viability and PCB transforming ability, such that, in the absence of a growth substrate, soil would have to be reinoculated to maintain PCB biodegradation. 15 refs., 2 tabs., 5 figs

  17. 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.

  18. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    Objectives: Pseudomonas aeruginosa is an opportunistic human pathogen, commonly infecting cystic fibrosis (CF) patients. Aspergilli, especially Aspergillus fumigatus, are also frequently isolated from CF patients. Our aim was to examine the possible interaction between P. aeruginosa and different...... Aspergillus species. Methods: A suspension of fungal spores was streaked onto WATM agar plates. After 24 hours incubation at 37 °C, a P. aeruginosa overnight culture was streaked out perpendicular to the fungal streak. The plates were incubated at 37 °C for five days, examined and plugs were extracted...... in the contact area of A. niger, A. flavus, A. oryzae, but not A. fumigatus. In addition, other metabolites with UV chromophores similar to the phenazines were only found in the contact zone between Aspergillus and Pseudomonas. No change in secondary metabolite profiles were seen for the Aspergilli, when...

  19. Degradation of microbial polyesters.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P

    2004-08-01

    Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB. PMID:15289671

  20. Proteolytic inactivation of cytokines by Pseudomonas aeruginosa.

    OpenAIRE

    Parmely, M; Gale, A; Clabaugh, M.; Horvat, R; Zhou, W W

    1990-01-01

    Pseudomonas aeruginosa alkaline protease and elastase are thought to contribute to bacterial invasiveness, tissue damage, and immune suppression in animals and patients infected with the bacterium. This study examined the ability of the two proteases to inactivate a number of cytokines that mediate immune and inflammatory responses. Human recombinant gamma interferon (rIFN-gamma) and human recombinant tumor necrosis factor alpha were inactivated by both proteases. Murine rIFN-gamma was relati...

  1. The Determination of Bio-kinetic Coefficients of Crude Oil Biodegradation Using Pseudomonas Aeruginosa Bacteria

    Directory of Open Access Journals (Sweden)

    M.R Talaie Khozani

    2010-07-01

    Full Text Available "n "n "nBackgrounds and Objectives: Oil pollution can be generated as a result of spillage, leakage, discharge, exploration, production, refining, transport and storage of crude oil and fuels in the environment. Consequently, many researchers have developed and studied the chemical, physical and biological methods to degrade crude oil. Among them, the biological treatments are the most interesting as they are simple and economical methods. The aim of this study was to determine biokinetic coefficients of crude oil degradation by pseudomonas aerogenusa. This microorganism was isolated in our previous work."nMaterials and Methods: In this study the bio-kinetic coefficients of crude oil biodegradation were evaluated. Pseudomonas aerogenusa bacteria which had been isolated from the soil sample taken from a gas station in our previous work were used in this study. This microorganism was cultured in the liquid medium containing crude oil as sole carbon source. Finally with determining the amount of microorganisms and crude oil concentration during biodegradation process, the bio-kinetic coefficients based on modified Monod equation were calculated."nResults: bio-kinetic coefficients obtained from laboratory studies are vital factors in industrial applications. As a result, the bio-kinetic study was performed to find bio-kinetic coefficients for biodegradation of crude oil using the isolated bacteria. The results showed that ,Y, k and were equal 0.107 , 0.882 , 9.39 and 169.3 respectively."nCoculusion:Our results showed that pseudomonas aerogenusa is usable for treatment of oily wastewaters in the full scale facility. Results of this study indicated bio kinetics confections.

  2. 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.

  3. Isolation of TNT tolerant pseudomonas species (Strain KA from TNT contaminated soil biotransformation of TNT

    Directory of Open Access Journals (Sweden)

    Avinash M. Tope

    2001-04-01

    Full Text Available "A 2,4,6-trinitrotoluene (TNT utilising bacterium, Pseudomonas species (strain KA was isolated from soils of a munitions processing unit and studied for itsability to grow and metabolise TNT. The result indicated that the isolate could grow aerobically in a minimal salt medium containing 0.25 mM/l TNT at 30 °C. It could completely transform 0.25 mM/l TNT in 5 days giving 2-isomeric monoaminodinitrotoluenes, namely 4-aminodinitrotoluene and 2-aminodinitrotoluene. Products of TNT transformation were analysed and confirmed by thin layer chromatography and gas chromatography coupled with mass spectrometry. Both, growth of the isolate and biotransformation rates were better supported on sugar and ammonium salt when added to the medium separately. Pseudomonas species (strain KA showed maximum TNT transformation efficiency in the presence of mannose. For degradation of TNT, this strain can be employed to initiate the process in association with the other microbial members that can collectively degrade TNT .

  4. 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.

  5. Pseudomonas putida Stimulates Primordia on Agaricus bitorquis.

    Science.gov (United States)

    Colauto, Nelson B; Fermor, Terry R; Eira, Augusto F; Linde, Giani A

    2016-04-01

    Casing layer is one step of Agaricus bisporus cultivation where there is a competitive environment with a high number of microorganisms and diversity interacting with mycelia. It is suggested that a minimal community of these microorganisms would be necessary to stimulate fructification. However, A. bisporus is not able to produce primordia in sterile casing layers or Petri dishes. Thus, the objective of this study was to characterize bacterial microbiota of casing layers from A. bisporus cultivation, isolate, identify and characterize the bacteria responsible for the stimulation of primordium and their action mechanism using Agaricus bitorquis as a primordium stimulation model. Bacterial and Pseudomonas spp. communities of different casing layers of A. bisporus cultivation were collected and quantified. It was concluded that Pseudomonas spp. corresponds to 75-85% of bacterial population of the casing layers in A. bisporus cultivation and among those 12% are Pseudomonas putida. Four biochemical assays were used to identify P. putida. In vitro primordium stimulation of living P. putida and non-living bacterial suspensions, after chemical or physical treatments, was tested using A. bitorquis as a primordium stimulation model. Primordium stimulation assay was registered by photographs, and micrographs of vertical cut of primordium were registered by scanning electron microscope. Interaction of living P. putida with A. bitorquis mycelia is capable of stimulating primordial instead of non-living bacterial suspensions. Stimulation of A. bitorquis primordia does not imply or is related to mycelial growth inhibition, but a hierarchical relation of primordium succession and development is suggested. PMID:26742772

  6. Using Pseudomonas spp. for Integrated Biological Control.

    Science.gov (United States)

    Stockwell, Virginia O; Stack, James P

    2007-02-01

    ABSTRACT Pseudomonas spp. have been studied for decades as model organisms for biological control of plant disease. Currently, there are three commercial formulations of pseudomonads registered with the U.S. Environmental Protection Agency for plant disease suppression, Bio-Save 10 LP, Bio-Save 11 LP, and BlightBan A506. Bio-Save 10 LP and Bio-Save 11 LP, products of Jet Harvest Solutions, Longwood, FL, contain Pseudomonas syringae strains ESC-10 and ESC-11, respectively. These products are applied in packinghouses to prevent postharvest fungal diseases during storage of citrus, pome, stone fruits, and potatoes. BlightBan A506, produced by NuFarm Americas, Burr Ridge, IL, contains P. fluorescens strain A506. BlightBan A506 is applied primarily to pear and apple trees during bloom to suppress the bacterial disease fire blight. Combining BlightBan A506 with the antibiotic streptomycin improves control of fire blight, even in areas with streptomycin-resistant populations of the pathogen. BlightBan A506 also may reduce fruit russet and mild frost injury. These biocontrol products consisting of Pseudomonas spp. provide moderate to excellent efficacy against multiple production constraints, are relatively easy to apply, and they can be integrated with conventional products for disease control. These characteristics will contribute to the adoption of these products by growers and packinghouses. PMID:18944382

  7. Adhesion of Pseudomonas fluorescens onto nanophase materials

    Science.gov (United States)

    Webster, Thomas J.; Tong, Zonghua; Liu, Jin; Banks, M. Katherine

    2005-07-01

    Nanobiotechnology is a growing area of research, primarily due to the potentially numerous applications of new synthetic nanomaterials in engineering/science. Although various definitions have been given for the word 'nanomaterials' by many different experts, the commonly accepted one refers to nanomaterials as those materials which possess grains, particles, fibres, or other constituent components that have one dimension specifically less than 100 nm. In biological applications, most of the research to date has focused on the interactions between mammalian cells and synthetic nanophase surfaces for the creation of better tissue engineering materials. Although mammalian cells have shown a definite positive response to nanophase materials, information on bacterial interactions with nanophase materials remains elusive. For this reason, this study was designed to assess the adhesion of Pseudomonas fluorescens on nanophase compared to conventional grain size alumina substrates. Results provide the first evidence of increased adhesion of Pseudomonas fluorescens on alumina with nanometre compared to conventional grain sizes. To understand more about the process, polymer (specifically, poly-lactic-co-glycolic acid or PLGA) casts were made of the conventional and nanostructured alumina surfaces. Results showed similar increased Pseudomonas fluorescens capture on PLGA casts of nanostructured compared to conventional alumina as on the alumina itself. For these reasons, a key material property shown to enhance bacterial adhesion was elucidated in this study for both polymers and ceramics: nanostructured surface features.

  8. Screening of Gibberellic Acid Production by Pseudomonas SPP

    International Nuclear Information System (INIS)

    The microbial gibberellic acid (GA3) production of Pseudomonas spp., was studied and qualitatively indentified by UV spectrophotometer. 20 strains of Pseudomonas spp., were isolated and screened the gibberellic acid productivily in King's B medium. Among them, only four strains can produce microbial gibberellic acid. The Rf values and colour appearance under UV were the same as authentic gibberellic acid. Moreover, the gibberellic acid producer strains were identified as Pseudomonas spp., by cultural, biochemical and drug sensitivity pattern.

  9. Implications of a novel Pseudomonas species on low density polyethylene biodegradation: an in vitro to in silico approach.

    Science.gov (United States)

    Bhatia, Mayuri; Girdhar, Amandeep; Tiwari, Archana; Nayarisseri, Anuraj

    2014-01-01

    Degradation of Petroleum-plastics like Low Density Polyethylene (LDPE) is a budding challenge due to increasing white pollution. The present investigation has focused the aspect through microbial assisted biodegradation. Various indigenous microorganisms were isolated from collected municipal landfill soil. Growth medium enriched with 0.2 g of LDPE powder was used to screen the soil bacteria with biodegradation potential. The screened bacteria were subjected to biodegradation assay in presence of LDPE sheets in growth medium. Four strains gave 5%, 17.8%, 0.9% and 0.6% degradation rate based on weight loss in the conducted in vitro assay for four days. The maximum degraded sheet was analyzed through Scanning Electron Microscopy, Fourier transform infrared spectroscopy and Thermogravimetry, taking undegraded LDPE sheet as control. Results illustrated one-step weight loss with control and three-step weight loss with test. Thus, it proved the efficacy of isolated strain. The strain identification was carried out by genomic DNA isolation followed by PCR and 16S rRNA sequencing. Genotypic identification revealed the bacterium as Pseudomonas citronellolis. BLAST gave a similarity with the database of 96%, thus phylogenetic assessment clarified the bacterium as a novel strain. The isolate was named as Pseudomonas citronellolis EMBS027 and sequence was deposited as LDPE degrading species, in GenBank with accession number KF361478. PMID:25932357

  10. 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

  11. Polysaccharide degradation systems of the saprophytic bacterium Cellvibrio japonicus.

    Science.gov (United States)

    Gardner, Jeffrey G

    2016-07-01

    Study of recalcitrant polysaccharide degradation by bacterial systems is critical for understanding biological processes such as global carbon cycling, nutritional contributions of the human gut microbiome, and the production of renewable fuels and chemicals. One bacterium that has a robust ability to degrade polysaccharides is the Gram-negative saprophyte Cellvibrio japonicus. A bacterium with a circuitous history, C. japonicus underwent several taxonomy changes from an initially described Pseudomonas sp. Most of the enzymes described in the pre-genomics era have also been renamed. This review aims to consolidate the biochemical, structural, and genetic data published on C. japonicus and its remarkable ability to degrade cellulose, xylan, and pectin substrates. Initially, C. japonicus carbohydrate-active enzymes were studied biochemically and structurally for their novel polysaccharide binding and degradation characteristics, while more recent systems biology approaches have begun to unravel the complex regulation required for lignocellulose degradation in an environmental context. Also included is a discussion for the future of C. japonicus as a model system, with emphasis on current areas unexplored in terms of polysaccharide degradation and emerging directions for C. japonicus in both environmental and biotechnological applications. PMID:27263016

  12. 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.

  13. Immunological characterization of ice nucleation proteins from Pseudomonas syringae, Pseudomonas fluorescens, and Erwinia herbicola.

    OpenAIRE

    Deininger, C A; Mueller, G M; Wolber, P K

    1988-01-01

    Antibodies were raised against the InaW protein, the product of the ice nucleation gene of Pseudomonas fluorescens MS1650, after protein isolation from an Escherichia coli clone. On Western blots (immunoblots), these antibodies recognized InaW protein and InaZ protein (the ice nucleation gene product of Pseudomonas syringae S203), produced by both E. coli clones and the source organisms. The InaZ protein appeared in P. syringae S203 during stationary phase; its appearance was correlated with ...

  14. Synthesis and photovoltaic performance of novel polymeric metal complex sensitizer with benzodithiophene or carbazole derivative as donor in dye-sensitized solar cell

    Science.gov (United States)

    Liao, Yanlong; Hu, Jiaomei; Zhu, Chunxiao; Liu, Ye; Chen, Xu; Chen, Chenqi; Zhong, Chaofan

    2016-03-01

    Four donor-acceptor (D-A) types of novel conjugated polymeric metal complex dyes (P1-P4) with Zn (II) or Cd (II) complexes as the electron acceptors and benzodithiophene or carbazole derivative as the electron donors were designed and prepared, as promising sensitizers for dye-sensitized solar cells (DSSCs). Diaminomaleonitrile acted as ancillary ligand. The structures of the polymers were confirmed, and their thermal, optical, electrochemical, and photovoltaic properties were investigated. All conjugated polymers exhibit good thermal stability with onset decomposition temperatures with 5% weight loss over 315 °C, broad absorption with the onset of absorption at 588 nm in the visible region, and relatively lower HOMO energy levels from -5.54 to -5.71 eV. The DSSC device based on P2 which containing Cd(II) as coordination metal ion and benzodithiophene derivative as donor exhibited the highest power conversion efficiency of 2.18% under the AM 1.5 G (100 mW cm-2) sunlight illumination with an open-circuit voltage of Voc = 0.68 V, a short current density of Jsc = 4.85 mA cm-2, and a fill factor of FF = 66.2%, respectively. Therefore, these results provide a new way to design dye sensitizers for DSSCs.

  15. 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.

  16. Synthesis, Crystal Structure and Theoretical Studies of (E)-1-((9-(2-(2-methoxyethoxy)ethyl)-9H-carbazol-3-yl)methylene)thiosemicarbazide

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-Qiu; ZHANG Zhi-Wen; LI Dan-Dan; ZHOU Hong-Ping; TIAN Yu-Peng; WU Jie-Ying

    2013-01-01

    A novel thiosemicarbazide derivative,(E)-1-(9-(2-(2-methoxyethoxy)ethyl)-9H-carbazol-3-yl) methylene)-thiosemicarbazide (CMT),was synthesized and structurally characterized by IR,1H-NMR,EI-MS and single-crystal X-ray diffraction.It crystallizes in monoclinic,space group P21/c with a =14.769(5),b =8.279(5),c =17.166(5) (A),β =114.391(5)°,V=1911.6(14) (A)3,Z =4,F(000) =784,Dc =1.287 g/m3,Mr =370.47,μ =0.190 mm-1,the final R =0.0390 and wR =0.1358 for 1446 observed reflections with I > 2σ(Ⅰ).The UV-vis absorption spectra of CMT were explained based on quantum chemical calculations,using time dependent density functional theory (TD-DFT) at the B3LYP/6-31G (d) level.

  17. 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.

  18. 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.

  19. Biodegradation Of 4-Chlorobiphenyl By Pseudomonas synxantha

    OpenAIRE

    Dhanjal Noorpreet Inder Kaur; Cameotra Swaranjit Singh

    2014-01-01

    The stabilization and disposal of polychlorinated biphenyls (PCBs) from soil environment and wetland areas is of great concern for health and safety. Wetland remediation with microorganisms is an approach for treating PCBs. A bacterial strain was isolated from hydrocarbon contaminated soil of Ropar, Punjab, able to degrade PCBs under aerobic conditions. The percentage of degradation with 100 mM/ml of 4-chlorobiphenyl was up to 90%. Degradation was monitored by mass spectrometry, high performa...

  20. 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

    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....... 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...

  1. INTERMITTENT DEGRADATION AND SCHIZOTYPY

    OpenAIRE

    Roché, Matthew W.; Silverstein, Steven M.; Lenzenweger, Mark F.

    2015-01-01

    Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy) is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-repo...

  2. Production of metabolites from chloro biphenyls by resting cells of Pseudomonas strain LB400 after growth on different carbon sources

    International Nuclear Information System (INIS)

    The transformation of polychlorinated biphenyl (PCB), when exposed to microorganisms, into chlorobenzoic acid metabolites was studied. PCBs are widely used in electrical transformers and have become widely dispersed in the environment. A proposed system for clean up of PCBs involves the combined use of anaerobic reductive dehalogenation of highly chlorinated congeners followed by aerobic degradation of moderately chlorinated PCBs, mediated by oxidative ring attack. Much of this work focused on biphenyl-grown cells, in particular Pseudomonas strain LB400 grown on biphenyl, which contains a multicomponent enzyme system. It was shown that resting cells of Pseudomonas strain LB400, grown on glycerol or glucose, could also transform purified PCB congeners and mixtures of PCBs in Aroclors, however, transformation rates were less than those observed with biphenyl-grown cells. 29 refs., 2 tabs., 2 figs

  3. 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.

  4. 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. PMID:27594974

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Aromatic Hydrocarbons: Degrading Bacteria in the Desert Soil of Kuwait

    International Nuclear Information System (INIS)

    Soil samples of different levels of oil pollutants were collected from Kuwait's Burgan Oil Field, near an oil lake. The samples represented, highly polluted (8.0% w/w), moderately polluted (2.1%-3.4%) and slightly polluted (2.1%-3.4%) and slightly polluted (0.5- 0.8%). The aromatic fractions of the collected samples were in the range of (0.21-2.57g/100g) soil. (GC) analysis of the aromatic fractions of the resolution of the different individual (PAHs) revealed the presence of (16) different (PAHs) resolved from the aromatic fraction of the highly polluted sample (S3). (15), (14) and (13) individual (PAHs) were identified soil samples (S5), (S2) and (S1, S4, S6) respectively. The most frequent (PAH) was indeno (1, 2, 3-c, d) pyrene (22.5%-45.11%) followed chrysene (13.6%-19.48%). Eight carcinogenic (PAHs) were resolved from the aromatic fractions of the polluted samples. Total carcinogenic (PAHs) recorded in this study were in this study were in the range of (11.53) (forS4) - (510.98) (for S3) ppm. The counts of (CFU) of aromatic degraders (AD) were in the range of (3x10) - (110x 10) (CFU/g) soil (with a percent of (2.2%-69.6%)). The results show that, higher counts of (AD) were recorded from a highly polluted sample (S3), followed by the moderately polluted samples; total of (51) bacteria, that gave presumptive positive biodegradation activities, were isolated and identified (45.1%) of them were isolated and identified. (45.1%) of them were isolated from the highly polluted sample (S3). Total of (13) different species were identified of which Micrococcus luteus was more frequent (23.5) followed by Bacillus licheniformis (19.6%) and Bacillus subtilis (11.8%). The three Pseudomonas species collectively were presented by (11.8%). Five different species proved to be of good activities, they are: Bacillus brevis, Bacillus lichenoformis, Pseudomonas aeruginosa, Pseudomonas stutzeri and Pseudomonas flourescens. The ability of five species and their mixture was

  11. 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

  12. 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...... between cystic fibrosis patients has occurred....

  13. 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.

  14. 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 Section 866.3415 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES..., abscesses, and meningitis (inflammation of brain membranes). Pseudomonas pseudomallei causes melioidosis,...

  15. 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

  16. 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

  17. Recombineering using RecET from Pseudomonas syringae

    Science.gov (United States)

    Here we report the identification of functions that promote genomic recombination of linear DNA introduced into Pseudomonas cells by electroporation. The genes encoding these functions were identified in Pseudomonas syringae pv. syringae B728a based on similarity to the lambda Red Exo/Beta and RecE...

  18. 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

  19. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  20. 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....

  1. 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%.

  2. Targeting quorum sensing in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Jakobsen, Tim Holm; Bjarnsholt, Thomas; Jensen, Peter Østrup;

    2013-01-01

    Bacterial resistance to conventional antibiotics combined with an increasing acknowledgement of the role of biofilms in chronic infections has led to a growing interest in new antimicrobial strategies that target the biofilm mode of growth. In the aggregated biofilm mode, cell-to-cell communication...... alternative antibacterial strategies. Here, we review state of the art research of quorum sensing inhibitors against the opportunistic human pathogen Pseudomonas aeruginosa, which is found in a number of biofilm-associated infections and identified as the predominant organism infecting the lungs of cystic...

  3. Versatile cloning vector for Pseudomonas aeruginosa.

    OpenAIRE

    Wood, D O; Hollinger, M F; Tindol, M B

    1981-01-01

    A pBR322:RSF1010 composite plasmid, constructed in vitro, was used as a cloning vector in Pseudomonas aeruginosa. This nonamplifiable plasmid, pMW79, has a molecular weight of 8.4 X 10(6) and exists as a multicopy plasmid in both P. aeruginosa and Escherichia coli. In P. aeruginosa strain PAO2003, pMW79 conferred resistance to carbenicillin and tetracycline. Characterization of pMW79 with restriction enzymes revealed that four enzymes (BamHI, SalI, HindIII, and HpaI) cleaved the plasmid at un...

  4. Suppression of Aspergillus by Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jensen, Britt Guillaume; Jelsbak, Lars; Søndergaard, Ib;

    Objectives: Cystic fibrosis patients are commonly infected by Pseudomonas aeruginosa, but Aspergilli are also frequently isolated. Our aim was to examine the possible interaction between P. aeruginosa and different Aspergillus. Methods: A suspension of 106 fungal spores/ml was streaked onto WATM...... suppressed growth of A. fumigatus, A. niger, A. flavus, A. oryzae, A. terreus and E. nidulans. HPLC and LC-DAD-MS results showed an increase in phenazine-1-carboxylic acid and phenazine-1-carboxamide production by P. aeruginosa in the contact area of Aspergillus. Different quinolones were also identified...

  5. Uranium accumulation by Pseudomonas sp. EPS-5028

    International Nuclear Information System (INIS)

    Pseudomonas sp. EPS-5028 was examined for the ability to accumulate uranium from solutions. The uptake of uranium by this microorganism is very rapid and is affected by pH but not by temperature, metabolic inhibitors, culture time and the presence of various cations and anions. The amount of uranium absorbed by the cells increased as the uranium concentration of the solution increased up to 55 mg uranium/g cell dry weight. Electron microscopy indicated that uranium accumulated intracellularly as needle-like fibrils. Uranium could be removed chemically from the cells, which could then be reused a a biosorbent. (orig.)

  6. 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....... 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...... March 2015). We previously searched PubMed using the terms vaccin* AND cystic fibrosis (last search 30 May 2013). SELECTION CRITERIA: Randomised trials (published or unpublished) comparing Pseudomonas aeruginosa vaccines (oral, parenteral or intranasal) with control vaccines or no intervention in cystic...

  7. 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...

  8. 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

    2016-01-01

    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. PMID:27517944

  9. 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.

  10. 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.

  11. Inability of Pseudomonas stutzeri denitrification mutants with the phenotype of Pseudomonas aeruginosa to grow in nitrous oxide.

    OpenAIRE

    1985-01-01

    Pseudomonas aeruginosa PAO1 reduced nitrous oxide to dinitrogen but did not grow anaerobically in nitrous oxide. Two transposon insertion Nos- mutants of Pseudomonas stutzeri exhibited the P. aeruginosa phenotype. Growth yield studies demonstrated that nitrous oxide produced in vivo was productively respired, but nitrous oxide supplied exogenously was not. The defect may be in electron transport or in nitrous oxide uptake.

  12. Bacterial Degradation of Cyanide and Its Metal Complexes under Alkaline Conditions

    OpenAIRE

    Luque-Almagro, Víctor M.; Huertas, María-J.; Martínez-Luque, Manuel; Moreno-Vivián, Conrado; Roldán, M. Dolores; García-Gil, L. Jesús; Castillo, Francisco; Blasco, Rafael

    2005-01-01

    A bacterial strain able to use cyanide as the sole nitrogen source under alkaline conditions has been isolated. The bacterium was classified as Pseudomonas pseudoalcaligenes by comparison of its 16S RNA gene sequence to those of existing strains and deposited in the Colección Española de Cultivos Tipo (Spanish Type Culture Collection) as strain CECT5344. Cyanide consumption is an assimilative process, since (i) bacterial growth was concomitant and proportional to cyanide degradation and (ii) ...

  13. 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%.

  14. Silk structure and degradation.

    Science.gov (United States)

    Liu, Bin; Song, Yu-wei; Jin, Li; Wang, Zhi-jian; Pu, De-yong; Lin, Shao-qiang; Zhou, Chan; You, Hua-jian; Ma, Yan; Li, Jin-min; Yang, Li; Sung, K L Paul; Zhang, Yao-guang

    2015-07-01

    To investigate the structure of silk and its degradation properties, we have monitored the structure of silk using scanning electron microscopy and frozen sections. Raw silk and degummed raw silk were immersed in four types of degradation solutions for 156 d to observe their degradation properties. The subcutaneous implants in rats were removed after 7, 14, 56, 84, 129, and 145 d for frozen sectioning and subsequent staining with hematoxylin and eosin (H.E.), DAPI, Beta-actin and Collagen I immunofluorescence staining. The in vitro weight loss ratio of raw silk and degummed raw silk in water, PBS, DMEM and DMEM containing 10% FBS (F-DMEM) were, respectively, 14%/11%, 12.5%/12.9%, 11.1%/14.3%, 8.8%/11.6%. Silk began to degrade after 7 d subcutaneous implantation and after 145 d non-degraded silk was still observed. These findings suggest the immunogenicity of fibroin and sericin had no essential difference. In the process of in vitro degradation of silk, the role of the enzyme is not significant. The in vivo degradation of silk is related to phagocytotic activity and fibroblasts may be involved in this process to secrete collagen. This study also shows the developing process of cocoons and raw silk. PMID:25982316

  15. 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.

  16. 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.

  17. SPECIFIC DEGRADATION OF WATERSHEDS

    Institute of Scientific and Technical Information of China (English)

    Boubacar KANE; Pierre Y.JULIEN

    2007-01-01

    An extensive database of reservoir sedimentation surveys throughout continental United States is compiled and analyzed to determine specific degradation SD relationships as function of mean annual rainfall R, drainage area A, and watershed slope S. The database contains 1463 field measurements and specific degradation relationships are defined as function of A, R and S. Weak trends and significant variability in the data are noticeable. Specific degradation measurements are log normally distributed with respect to R, A, and S and 95% confidence intervals are determined accordingly. The accuracy of the predictions does not significantly increase as more independent variables are added to the regression analyses.

  18. Uranium and thorium uptake by live and dead cells of Pseudomonas Sp

    International Nuclear Information System (INIS)

    This study presents uptake of uranium (U) and thorium (Th) by live and dead cells of Pseudomonas Sp. Increasing concentration of U and Tb showed decrease in absorption by Pseudomonas Sp. Dead cells of Pseudomonas Sp. exhibited same or more uptake of U and Th than living cells. Increasing temperature promotes uptake of U and Th by Pseudomonas Sp. (author)

  19. Overlapping yet response-specific transcriptome alterations characterize the nature of tobacco-Pseudomonas syringae interactions

    Directory of Open Access Journals (Sweden)

    Zoltán eBozsó

    2016-03-01

    Full Text Available In this study transcriptomic alterations of bacterially induced pattern triggered immunity (PTI were compared with other types of tobacco-Pseudomonas interactions. In addition, using pharmacological agents we blocked some signal transduction pathways (Ca2+ influx, kinases, phospholipases, proteasomic protein degradation to find out how they contribute to gene expression during PTI. PTI is the first defense response of plant cells to microbes, elicited by their widely conserved molecular patterns. Tobacco is an important model of Solanaceae to study resistance responses, including defense mechanisms against bacteria. In spite of these facts the transcription regulation of tobacco genes during different types of plant bacterial interactions is not well described. In this paper we compared the tobacco transcriptomic alterations in microarray experiments induced by (i PTI inducer Pseudomonas syringae pv. syringae type III secretion mutant (hrcC at earlier (6 hours post inoculation and later (48 hpi stages of defense, (ii wild type P. syringae (6 hpi that causes effector triggered immunity (ETI and cell death (HR and (iii disease-causing Pseudomonas syringae pv. tabaci (6 hpi. Among the different treatments the highest overlap was between the PTI and ETI at 6 hpi, however, there were groups of genes with specifically altered activity for either type of defenses. Instead of quantitative effects of the virulent P. tabaci on PTI-related genes it influenced transcription qualitatively and blocked the expression changes of a special set of genes including ones involved in signal transduction and transcription regulation. P. tabaci specifically activated or repressed other groups of genes seemingly not related to either PTI or ETI.Kinase and phospholipase A inhibitors had highest impacts on the PTI response and effects of signal inhibitors on transcription greatly overlapped. Remarkable interactions of phospholipase C-related pathways with the proteasomal

  20. Headspace analysis of volatile metabolites of Pseudomonas aeruginosa and related species by gas chromatography-mass spectrometry.

    OpenAIRE

    Labows, J N; McGinley, K J; Webster, G F; Leyden, J J

    1980-01-01

    Gas chromatographic-mass spectrometric analysis of headspace volatiles was performed on cultures of 11 strains of Pseudomonas aeruginosa and 1 strain each of Pseudomonas cepacia, Pseudomonas putida, Pseudomonas putrefaciens, Pseudomonas fluorescens, and Pseudomonas maltophilia. All strains of Pseudomonas aeruginosa produced a distinctive series of odd-carbon methyl ketones, particularly 2-nonanone and 2-undecanone, and 2-aminoacetophenone. The other strains failed to produce 2-aminoacetopheno...