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Sample records for solvent tolerant pseudomonas

  1. Improvement in solvent tolerance by exogenous glycerol in Pseudomonas sp. BCNU 106.

    Science.gov (United States)

    Choi, H J; Lim, B R; Park, Y J; Joo, W H

    2017-08-01

    Solvent hypertolerant Pseudomonas sp. BCNU 106 still has some underlying growth limitation in solvents. Therefore, efficient mass cultivation methods are needed to pursue its applications in biotechnology. Pseudomonas sp. BCNU 106 was cultured in a medium supplemented with 0·05 mol l -1 glycerol and cell survival was monitored during its cultivation in the presence of 1% (v/v) toluene. Exogenously supplemented glycerol provided more protection against damage caused by toluene stress and conferred higher solvent tolerance of Pseudomonas sp. BCNU 106 to toluene compared to control Pseudomonas sp. BCNU 106 without the supplementation of glycerol. This low-cost mass cultivation method can be used to efficiently apply solvent-tolerant bacteria in biotransformation and biodegradation. Protection against toluene and improvement in bacterial cell growth by supplementation of glycerol in the presence of toluene are demonstrated in this study. This result can be used to solve growth-related hindrances of solvent-tolerant bacteria and establish their low-cost mass cultivation, thereby broadening their industrial and environmental applications. © 2017 The Society for Applied Microbiology.

  2. Testosterone 15β-hydroxylation by solvent tolerant Pseudomonas putida S12

    NARCIS (Netherlands)

    Ruijssenaars, H.J.; Sperling, E.M.G.M.; Wiegerinck, P.H.G.; Brands, F.T.L.; Wery, J.; Bont, J.A.M.de

    2007-01-01

    A steroid 15β-hydroxylating whole-cell solvent tolerant biocatalyst was constructed by expressing the Bacillus megaterium steroid hydroxylase CYP106A2 in the solvent tolerant Pseudomonas putida S12. Testosterone hydroxylation was improved by a factor 16 by co-expressing Fer, a putative Fe-S protein

  3. Transposon mutations in the flagella biosynthetic pathway of the solvent-tolerant Pseudomonas putida S12 result in a decreased expression of solvent efflux genes

    NARCIS (Netherlands)

    Kieboom, J; Bruinenberg, R; Keizer-Gunnink, [No Value; de Bont, JAM

    2001-01-01

    Fourteen solvent-sensitive transposon mutants were generated from the solvent-tolerant Pseudomonas putida strain S12 by applying the TnMOD-KmO mutagenesis system. These mutants were unable to grow in the presence of octanol and toluene. By cloning the region flanking the transposon insertion point a

  4. Tolerance of anaerobic bacteria to chlorinated solvents.

    Science.gov (United States)

    Koenig, Joanna C; Groissmeier, Kathrin D; Manefield, Mike J

    2014-01-01

    The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation.

  5. Organic Solvent Tolerant Lipases and Applications

    Directory of Open Access Journals (Sweden)

    Shivika Sharma

    2014-01-01

    Full Text Available Lipases are a group of enzymes naturally endowed with the property of performing reactions in aqueous as well as organic solvents. The esterification reactions using lipase(s could be performed in water-restricted organic media as organic solvent(s not only improve(s the solubility of substrate and reactant in reaction mixture but also permit(s the reaction in the reverse direction, and often it is easy to recover the product in organic phase in two-phase equilibrium systems. The use of organic solvent tolerant lipase in organic media has exhibited many advantages: increased activity and stability, regiospecificity and stereoselectivity, higher solubility of substrate, ease of products recovery, and ability to shift the reaction equilibrium toward synthetic direction. Therefore the search for organic solvent tolerant enzymes has been an extensive area of research. A variety of fatty acid esters are now being produced commercially using immobilized lipase in nonaqueous solvents. This review describes the organic tolerance and industrial application of lipases. The main emphasis is to study the nature of organic solvent tolerant lipases. Also, the potential industrial applications that make lipases the biocatalysts of choice for the present and future have been presented.

  6. 40 CFR 180.1145 - Pseudomonas syringae; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas syringae; exemption from... FOOD Exemptions From Tolerances § 180.1145 Pseudomonas syringae; exemption from the requirement of a tolerance. Pseudomonas syringae is exempted from the requirement of a tolerance on all raw agricultural...

  7. Physiology of solvent tolerance in Pseudomonas putida S12

    NARCIS (Netherlands)

    Isken, S.

    2000-01-01

    Hydrophobic organic solvents, like toluene, are toxic for living organisms. This toxicity is an important drawback in the environmental biotechnology as well as in the application of solvents in the production of fine chemicals by whole-cell biotransformations. The effects of organic

  8. Effectiveness of halo-tolerant, auxin producing Pseudomonas and Rhizobium strains to improve osmotic stress tolerance in mung bean (Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Maqshoof Ahmad

    2013-12-01

    Full Text Available Halo-tolerant, auxin producing bacteria could be used to induce salt tolerance in plants. A number of Rhizobium and auxin producing rhizobacterial strains were assessed for their ability to tolerate salt stress by conducting osmoadaptation assay. The selected strains were further screened for their ability to induce osmotic stress tolerance in mung bean seedlings under salt-stressed axenic conditions in growth pouch/jar trials. Three most effective strains of Rhizobium and Pseudomonas containing ACC-deaminase were evaluated in combination, for their ability to induce osmotic stress tolerance in mung bean at original, 4, and 6 dS m-1 under axenic conditions. Results showed that sole inoculation of Rhizobium and Pseudomonas strains improved the total dry matter up to 1.4, and 1.9 fold, respectively, while the increase in salt tolerance index was improved up to 1.3 and 2.0 fold by the Rhizobium and Pseudomonas strains, respectively. However, up to 2.2 fold increase in total dry matter and salt tolerance index was observed due to combined inoculation of Rhizobium and Pseudomonas strains. So, combined application of Rhizobium and Pseudomonas strains could be explored as an effective strategy to induce osmotic stress tolerance in mung bean.

  9. Production of protease and lipase by solvent tolerant Pseudomonas aeruginosa PseA in solid-state fermentation using Jatropha curcas seed cake as substrate.

    Science.gov (United States)

    Mahanta, Nilkamal; Gupta, Anshu; Khare, S K

    2008-04-01

    Deoiled Jatropha seed cake was assessed for its suitability as substrate for enzyme production by solid-state fermentation (SSF). Solvent tolerant Pseudomonas aeruginosa PseA strain previously reported by us was used for fermentation. The seed cake supported good bacterial growth and enzyme production (protease, 1818 U/g of substrate and lipase, 625 U/g of substrate) as evident by its chemical composition. Maximum protease and lipase production was observed at 50% substrate moisture, a growth period of 72 and 120 h, and a substrate pH of 6.0 and 7.0, respectively. Enrichment with maltose as carbon source increased protease and lipase production by 6.3- and 1.6-fold, respectively. Nitrogen supplementation with peptone for protease and NaNO(3) for lipase production also enhanced the enzyme yield reaching 11,376 U protease activity and 1084 U lipase activity per gram of Jatropha seed cake. These results demonstrated viable approach for utilization of this huge biomass by solid-state fermentation for the production of industrial enzymes. This offers significant benefit due to low cost and abundant availability of cake during biodiesel production.

  10. Solvent-tolerant bacteria in biocatalysis.

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1998-01-01

    The toxicity of fine chemicals to the producer organism is a problem in several biotechnological production processes. In several instances, an organic phase can be used to extract the toxic product from the aqueous phase during a fermentation. With the discovery of solvent-tolerant bacteria, more

  11. 40 CFR 180.1114 - Pseudomonas fluorescens A506, Pseudomonas fluorescens 1629RS, and Pseudomonas syringae 742RS...

    Science.gov (United States)

    2010-07-01

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

  12. Effects of Organic Solvents on Indigo Formation by Pseudomonas sp. strain ST-200 Grown with High Levels of Indole.

    Science.gov (United States)

    Doukyu, N; Arai, T; Aono, R

    1998-01-01

    The indole tolerance level of Pseudomonas sp. strain ST-200 was 0.25 mg/ml. The level was raised to 4 mg/ml when diphenylmethane was added to the medium to 20% by volume. ST-200 grown in this two-phase culture system containing indole (1 mg/ml) and diphenylmethane (0.2 ml/ml) produced a water-soluble yellow pigment, isatic acid, and two water-insoluble and diphenylmethane-soluble pigments, blue indigo and purple indirubin. The amounts of the water-insoluble pigments corresponded to 0.5% (indigo) and 0.2% (indirubin) of the indole added to the medium. Of the conditions tried, indigo and indirubin were formed only when ST-200 was grown in the two-phase system overlaid with organic solvents with appropriate polarity.

  13. 40 CFR 180.1212 - Pseudomonas chlororaphis Strain 63-28; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas chlororaphis Strain 63-28... RESIDUES IN FOOD Exemptions From Tolerances § 180.1212 Pseudomonas chlororaphis Strain 63-28; exemption... for residues of the microbial pesticide Pseudomonas chlororaphis Strain 63-28 in or on all food...

  14. Bioremediation potential of a newly isolate solvent tolerant strain Bacillus thermophilus PS11

    Directory of Open Access Journals (Sweden)

    PAYEL SARKAR

    2012-01-01

    Full Text Available The increased generation of solvent waste has been stated as one of the most critical environmental problems. Though microbial bioremediation has been widely used for waste treatment but their application in solvent waste treatment is limited since the solvents have toxic effects on the microbial cells. A solvent tolerant strain of Bacillus thermophilus PS11 was isolated from soil by cyclohexane enrichment. Transmission electron micrograph of PS11 showed convoluted cell membrane and accumulation of solvents in the cytoplasm, indicating the adaptation of the bacterial strain to the solvent after 48h of incubation. The strain was also capable of growing in presence of wide range of other hydrophobic solvents with log P-values below 3.5. The isolate could uptake 50 ng/ml of uranium in its initial 12h of growth, exhibiting both solvent tolerance and metal resistance property. This combination of solvent tolerance and metal resistance will make the isolated Bacillus thermophilus PS11 a potential tool for metal bioremediation in solvent rich wastewaters.

  15. Selective labelling and eradication of antibiotic-tolerant bacterial populations in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Chua, Song Lin; Yam, Joey Kuok Hoong; Hao, Piliang

    2016-01-01

    Drug resistance and tolerance greatly diminish the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. Here we use a proteomics approach, pulsed stable isotope labelling with amino...... acids (pulsed-SILAC), to quantify newly expressed proteins in colistin-tolerant subpopulations of Pseudomonas aeruginosa biofilms (colistin is a 'last-resort' antibiotic against multidrug-resistant Gram-negative pathogens). Migration is essential for the formation of colistin-tolerant biofilm...

  16. 40 CFR 180.1200 - Pseudomonas fluorescens strain PRA-25; temporary exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Pseudomonas fluorescens strain PRA-25... RESIDUES IN FOOD Exemptions From Tolerances § 180.1200 Pseudomonas fluorescens strain PRA-25; temporary... established for residues of the microbial pesticide, pseudomonas fluorescens strain PRA-25 when used on peas...

  17. Enzymes from solvent-tolerant microbes: useful biocatalysts for non-aqueous enzymology.

    Science.gov (United States)

    Gupta, Anshu; Khare, S K

    2009-01-01

    Solvent-tolerant microbes are a newly emerging class that possesses the unique ability to thrive in the presence of organic solvents. Their enzymes adapted to mediate cellular and metabolic processes in a solvent-rich environment and are logically stable in the presence of organic solvents. Enzyme catalysis in non-aqueous/low-water media is finding increasing applications for the synthesis of industrially important products, namely peptides, esters, and other trans-esterification products. Solvent stability, however, remains a prerequisite for employing enzymes in non-aqueous systems. Enzymes, in general, get inactivated or give very low rates of reaction in non-aqueous media. Thus, early efforts, and even some recent ones, have aimed at stabilization of enzymes in organic media by immobilization, surface modifications, mutagenesis, and protein engineering. Enzymes from solvent-tolerant microbes appear to be the choicest source for studying solvent-stable enzymes because of their unique ability to survive in the presence of a range of organic solvents. These bacteria circumvent the solvent's toxic effects by virtue of various adaptations, e.g. at the level of the cytoplasmic membrane, by degradation and transformation of solvents, and by active excretion of solvents. The recent screening of these exotic microbes has generated some naturally solvent-stable proteases, lipases, cholesterol oxidase, cholesterol esterase, cyclodextrin glucanotransferase, and other important enzymes. The unique properties of these novel biocatalysts have great potential for applications in non-aqueous enzymology for a range of industrial processes.

  18. Production of thermostable and organic solvent-tolerant alkaline ...

    African Journals Online (AJOL)

    An alkaliphilic bacterium producing organic solvent-tolerant and thermostable alkaline protease was isolated from poultry litter site and identified as Bacillus coagulans PSB-07. Protease production under different submerged fermentation conditions were investigated with the aim of optimizing yield of enzyme. B. coagulans ...

  19. Novel AroA from Pseudomonas putida Confers Tobacco Plant with High Tolerance to Glyphosate

    Science.gov (United States)

    Yan, Hai-Qin; Chang, Su-Hua; Tian, Zhe-Xian; Zhang, Le; Sun, Yi-Cheng; Li, Yan; Wang, Jing; Wang, Yi-Ping

    2011-01-01

    Glyphosate is a non-selective broad-spectrum herbicide that inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS, also designated as AroA), a key enzyme in the aromatic amino acid biosynthesis pathway in microorganisms and plants. Previously, we reported that a novel AroA (PpAroA1) from Pseudomonas putida had high tolerance to glyphosate, with little homology to class I or class II glyphosate-tolerant AroA. In this study, the coding sequence of PpAroA1 was optimized for tobacco. For maturation of the enzyme in chloroplast, a chloroplast transit peptide coding sequence was fused in frame with the optimized aroA gene (PparoA1optimized) at the 5′ end. The PparoA1optimized gene was introduced into the tobacco (Nicotiana tabacum L. cv. W38) genome via Agrobacterium-mediated transformation. The transformed explants were first screened in shoot induction medium containing kanamycin. Then glyphosate tolerance was assayed in putative transgenic plants and its T1 progeny. Our results show that the PpAroA1 from Pseudomonas putida can efficiently confer tobacco plants with high glyphosate tolerance. Transgenic tobacco overexpressing the PparoA1optimized gene exhibit high tolerance to glyphosate, which suggest that the novel PpAroA1 is a new and good candidate applied in transgenic crops with glyphosate tolerance in future. PMID:21611121

  20. Display of a thermostable lipase on the surface of a solvent-resistant bacterium, Pseudomonas putida GM730, and its applications in whole-cell biocatalysis

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    Kwon Seok-Joon

    2006-04-01

    Full Text Available Abstract Background Whole-cell biocatalysis in organic solvents has been widely applied to industrial bioprocesses. In two-phase water-solvent processes, substrate conversion yields and volumetric productivities can be limited by the toxicity of solvents to host cells and by the low mass transfer rates of the substrates from the solvent phase to the whole-cell biocatalysts in water. Results To solve the problem of solvent toxicity, we immobilized a thermostable lipase (TliA from Pseudomonas fluorescens on the cell surface of a solvent-resistant bacterium, Pseudomonas putida GM730. Surface immobilization of enzymes eliminates the mass-transfer limitation imposed by the cell wall and membranes. TliA was successfully immobilized on the surface of P. putida cells using the ice-nucleation protein (INP anchoring motif from Pseudomonas syrinage. The surface location was confirmed by flow cytometry, protease accessibility and whole-cell enzyme activity using a membrane-impermeable substrate. Three hundred and fifty units of whole-cell hydrolytic activity per gram dry cell mass were obtained when the enzyme was immobilized with a shorter INP anchoring motif (INPNC. The surface-immobilized TliA retained full enzyme activity in a two-phase water-isooctane reaction system after incubation at 37°C for 12 h, while the activity of the free form enzyme decreased to 65% of its initial value. Whole cells presenting immobilized TliA were shown to catalyze three representative lipase reactions: hydrolysis of olive oil, synthesis of triacylglycerol and chiral resolution. Conclusion In vivo surface immobilization of enzymes on solvent-resistant bacteria was demonstrated, and appears to be useful for a variety of whole-cell bioconversions in the presence of organic solvents.

  1. Optimization of physical factors affecting the production of thermo-stable organic solvent-tolerant protease from a newly isolated halo tolerant Bacillus subtilis strain Rand

    Directory of Open Access Journals (Sweden)

    Salleh Abu

    2009-04-01

    Full Text Available Abstract Background Many researchers have reported on the optimization of protease production; nevertheless, only a few have reported on the optimization of the production of organic solvent-tolerant proteases. Ironically, none has reported on thermostable organic solvent-tolerant protease to date. The aim of this study was to isolate the thermostable organic solvent-tolerant protease and identify the culture conditions which support its production. The bacteria of genus Bacillus are active producers of extra-cellular proteases, and the thermostability of enzyme production by Bacillus species has been well-studied by a number of researchers. In the present study, the Bacillus subtilis strain Rand was isolated from the contaminated soil found in Port Dickson, Malaysia. Results A thermostable organic solvent-tolerant protease producer had been identified as Bacillus subtilis strain Rand, based on the 16S rRNA analysis conducted, as well as the morphological characteristics and biochemical properties. The production of the thermostable organic solvent-tolerant protease was optimized by varying various physical culture conditions. Inoculation with 5.0% (v/v of (AB600 = 0.5 inoculum size, in a culture medium (pH 7.0 and incubated for 24 h at 37°C with 200 rpm shaking, was the best culture condition which resulted in the maximum growth and production of protease (444.7 U/ml; 4042.4 U/mg. The Rand protease was not only stable in the presence of organic solvents, but it also exhibited a higher activity than in the absence of organic solvent, except for pyridine which inhibited the protease activity. The enzyme retained 100, 99 and 80% of its initial activity, after the heat treatment for 30 min at 50, 55, and 60°C, respectively. Conclusion Strain Rand has been found to be able to secrete extra-cellular thermostable organic solvent-tolerant protease into the culture medium. The protease exhibited a remarkable stability towards temperature and organic

  2. Highly Solvent Tolerance in Serratia marcescens IBBPo15

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    Mihaela Marilena Stancu

    Full Text Available ABSTRACT The aim of this study was to investigate the solvent tolerance mechanisms in Serratia marcescens strain IBBPo15 (KT315653. Serratia marcescens IBBPo15 exhibited remarkable solvent-tolerance, being able to survive in the presence of high concentrations (above 40% of toxic organic solvents, such as cyclohexane, n-hexane, n-decane, toluene, styrene, and ethylbenzene. S. marcescens IBBPo15 produced extracellular protease and the enzyme production decreased in cells exposed to 5% cyclohexane, n-hexane, toluene, styrene, and ethylbenzene, as compared with the control and n-decane exposed cells. S. marcescens IBBPo15 cells produced carotenoid pigments and alteration of pigments profile (i.e., phytoene, lycopene were observed in cells exposed to 5% cyclohexane, n-hexane, n-decane, toluene, styrene, and ethylbenzene. The exposure of S. marcescens IBBPo15 cells to 5% cyclohexane, n-hexane, n-decane, toluene, styrene, ethylbenzene induced also changes in the intracellular (e.g., 50 kDa protein and extracellular (e.g., 39, 41, 43, 53, 110 kDa proteins proteins profile. Significant RAPD, ARDRA, rep-PCR and PCR pattern modifications were not observed in DNA extracted from S. marcescens IBBPo15 cells exposed to 5% cyclohexane, n-hexane, n-decane, toluene, styrene, and ethylbenzene. Though only HAE1 and acrAB genes were detected in the genome of S. marcescens IBBPo15 cells, the unspecific amplification of other fragments being observed also when the primers for ompF and recA genes were used.

  3. Selective labelling and eradication of antibiotic-tolerant bacterial populations in Pseudomonas aeruginosa biofilms

    Science.gov (United States)

    Chua, Song Lin; Yam, Joey Kuok Hoong; Hao, Piliang; Adav, Sunil S.; Salido, May Margarette; Liu, Yang; Givskov, Michael; Sze, Siu Kwan; Tolker-Nielsen, Tim; Yang, Liang

    2016-01-01

    Drug resistance and tolerance greatly diminish the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. Here we use a proteomics approach, pulsed stable isotope labelling with amino acids (pulsed-SILAC), to quantify newly expressed proteins in colistin-tolerant subpopulations of Pseudomonas aeruginosa biofilms (colistin is a ‘last-resort' antibiotic against multidrug-resistant Gram-negative pathogens). Migration is essential for the formation of colistin-tolerant biofilm subpopulations, with colistin-tolerant cells using type IV pili to migrate onto the top of the colistin-killed biofilm. The colistin-tolerant cells employ quorum sensing (QS) to initiate the formation of new colistin-tolerant subpopulations, highlighting multicellular behaviour in antibiotic tolerance development. The macrolide erythromycin, which has been previously shown to inhibit the motility and QS of P. aeruginosa, boosts biofilm eradication by colistin. Our work provides insights on the mechanisms underlying the formation of antibiotic-tolerant populations in bacterial biofilms and indicates research avenues for designing more efficient treatments against biofilm-associated infections. PMID:26892159

  4. Selective labelling and eradication of antibiotic-tolerant bacterial populations in Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Chua, Song Lin; Yam, Joey Kuok Hoong; Hao, Piliang; Adav, Sunil S; Salido, May Margarette; Liu, Yang; Givskov, Michael; Sze, Siu Kwan; Tolker-Nielsen, Tim; Yang, Liang

    2016-02-19

    Drug resistance and tolerance greatly diminish the therapeutic potential of antibiotics against pathogens. Antibiotic tolerance by bacterial biofilms often leads to persistent infections, but its mechanisms are unclear. Here we use a proteomics approach, pulsed stable isotope labelling with amino acids (pulsed-SILAC), to quantify newly expressed proteins in colistin-tolerant subpopulations of Pseudomonas aeruginosa biofilms (colistin is a 'last-resort' antibiotic against multidrug-resistant Gram-negative pathogens). Migration is essential for the formation of colistin-tolerant biofilm subpopulations, with colistin-tolerant cells using type IV pili to migrate onto the top of the colistin-killed biofilm. The colistin-tolerant cells employ quorum sensing (QS) to initiate the formation of new colistin-tolerant subpopulations, highlighting multicellular behaviour in antibiotic tolerance development. The macrolide erythromycin, which has been previously shown to inhibit the motility and QS of P. aeruginosa, boosts biofilm eradication by colistin. Our work provides insights on the mechanisms underlying the formation of antibiotic-tolerant populations in bacterial biofilms and indicates research avenues for designing more efficient treatments against biofilm-associated infections.

  5. RpoN Modulates Carbapenem Tolerance in Pseudomonas aeruginosa through Pseudomonas Quinolone Signal and PqsE

    Science.gov (United States)

    Murakami, Keiji; Amoh, Takashi; Ono, Tsuneko; Miyake, Yoichiro

    2016-01-01

    The ability of Pseudomonas aeruginosa to rapidly modulate its response to antibiotic stress and persist in the presence of antibiotics is closely associated with the process of cell-to-cell signaling. The alternative sigma factor RpoN (σ54) is involved in the regulation of quorum sensing (QS) and plays an important role in the survival of stationary-phase cells in the presence of carbapenems. Here, we demonstrate that a ΔrpoN mutant grown in nutrient-rich medium has increased expression of pqsA, pqsH, and pqsR throughout growth, resulting in the increased production of the Pseudomonas quinolone signal (PQS). The link between pqsA and its role in carbapenem tolerance was studied using a ΔrpoN ΔpqsA mutant, in which the carbapenem-tolerant phenotype of the ΔrpoN mutant was abolished. In addition, we demonstrate that another mechanism leading to carbapenem tolerance in the ΔrpoN mutant is mediated through pqsE. Exogenously supplied PQS abolished the biapenem-sensitive phenotype of the ΔrpoN ΔpqsA mutant, and overexpression of pqsE failed to alter the susceptibility of the ΔrpoN ΔpqsA mutant to biapenem. The mutations in the ΔrpoN ΔrhlR mutant and the ΔrpoN ΔpqsH mutant led to susceptibility to biapenem. Comparison of the changes in the expression of the genes involved in QS in wild-type PAO1 with their expression in the ΔrpoN mutant and the ΔrpoN mutant-derived strains demonstrated the regulatory effect of RpoN on the transcript levels of rhlR, vqsR, and rpoS. The findings of this study demonstrate that RpoN negatively regulates the expression of PQS in nutrient-rich medium and provide evidence that RpoN interacts with pqsA, pqsE, pqsH, and rhlR in response to antibiotic stress. PMID:27431228

  6. Bioproduction of vanillin using an organic solvent-tolerant Brevibacillus agri 13.

    Science.gov (United States)

    Wangrangsimagul, Nuttawat; Klinsakul, Kunticha; Vangnai, Alisa S; Wongkongkatep, Jirarut; Inprakhon, Pranee; Honda, Kohsuke; Ohtake, Hisao; Kato, Junichi; Pongtharangkul, Thunyarat

    2012-01-01

    Nowadays, majority of vanillin supplied to the world market is chemically synthesized from a petroleum-based raw material, raising a concern among the consumers regarding the product safety. In this study, an organic solvent-tolerant Brevibacillus agri 13 previously reported for a strong predilectic property was utilized as a whole-cell biocatalyst for bioproduction of vanillin from isoeugenol (IG). B. agri 13 is the first biocatalyst reported for bioproduction of vanillin at a temperature as high as 45°C. Both pH and temperature were found to affect vanillin production significantly. An extreme level of organic solvent tolerance of B. agri 13 allowed us to utilize it in a biphasic system using organic solvents generally considered as highly toxic to most bacteria. With an addition of butyl acetate at 30% (v/v) as an organic second phase, toxicity of IG exerted onto the biocatalyst was reduced dramatically while faster and more efficient vanillin production was obtained (1.7 g/L after 48 h with 27.8% molar conversion).

  7. Metabolic response of Pseudomonas putida during redox biocatalysis in the presence of a second octanol phase.

    Science.gov (United States)

    Blank, Lars M; Ionidis, Georgios; Ebert, Birgitta E; Bühler, Bruno; Schmid, Andreas

    2008-10-01

    A key limitation of whole-cell redox biocatalysis for the production of valuable, specifically functionalized products is substrate/product toxicity, which can potentially be overcome by using solvent-tolerant micro-organisms. To investigate the inter-relationship of solvent tolerance and energy-dependent biocatalysis, we established a model system for biocatalysis in the presence of toxic low logP(ow) solvents: recombinant solvent-tolerant Pseudomonas putida DOT-T1E catalyzing the stereospecific epoxidation of styrene in an aqueous/octanol two-liquid phase reaction medium. Using (13)C tracer based metabolic flux analysis, we investigated the central carbon and energy metabolism and quantified the NAD(P)H regeneration rate in the presence of toxic solvents and during redox biocatalysis, which both drastically increased the energy demands of solvent-tolerant P. putida. According to the driven by demand concept, the NAD(P)H regeneration rate was increased up to eightfold by two mechanisms: (a) an increase in glucose uptake rate without secretion of metabolic side products, and (b) reduced biomass formation. However, in the presence of octanol, only approximately 1% of the maximally observed NAD(P)H regeneration rate could be exploited for styrene epoxidation, of which the rate was more than threefold lower compared with operation with a non-toxic solvent. This points to a high energy and redox cofactor demand for cell maintenance, which limits redox biocatalysis in the presence of octanol. An estimated upper bound for the NAD(P)H regeneration rate available for biocatalysis suggests that cofactor availability does not limit redox biocatalysis under optimized conditions, for example, in the absence of toxic solvent, and illustrates the high metabolic capacity of solvent-tolerant P. putida. This study shows that solvent-tolerant P. putida have the remarkable ability to compensate for high energy demands by boosting their energy metabolism to levels up to an order of

  8. Selective proteomic analysis of antibiotic-tolerant cellular subpopulations in pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Babin, Brett M.; Atangcho, Lydia; van Eldijk, Mark B.

    2017-01-01

    involved in central carbon metabolism. We differentiated the immediate proteomic response, characterized by an increase in flagellar motility, from the long-term adaptive strategy, which included the upregulation of purine synthesis. This targeted, selective analysis of a bacterial subpopulation...... amino acid tagging (BONCAT) method to enable selective proteomic analysis of a Pseudomonas aeruginosa biofilm subpopulation. Through controlled expression of a mutant methionyl-tRNA synthetase, we targeted BONCAT labeling to cells in the regions of biofilm microcolonies that showed increased tolerance...... demonstrates how the study of proteome dynamics can enhance our understanding of biofilm heterogeneity and antibiotic tolerance. IMPORTANCE Bacterial growth is frequently characterized by behavioral heterogeneity at the single-cell level. Heterogeneity is especially evident in the physiology of biofilms...

  9. An update on Pseudomonas aeruginosa biofilm formation, tolerance, and dispersal

    DEFF Research Database (Denmark)

    Harmsen, Morten; Yang, Liang; Pamp, Sünje Johanna

    2010-01-01

    We review the recent advances in the understanding of the Pseudomonas aeruginosa biofilm lifestyle from studies using in vitro laboratory setups such as flow chambers and microtiter trays. Recent work sheds light on the role of nutrients, motility, and quorum sensing in structure formation in P....... aeruginosa biofilms. The second messenger, c-di-GMP, is established as an important regulator of the synthesis of polysaccharide and protein components of the biofilm matrix. Extracellular DNA is shown to be an essential component of the biofilm matrix. It has become apparent that biofilm formation involves...... interactions between different subpopulations. The molecular mechanisms underlying the tolerance of biofilm bacteria to antimicrobial agents are beginning to be unraveled, and new knowledge has been obtained regarding the environmental cues and regulatory mechanisms involved in biofilm dispersal....

  10. The catabolite repression control protein Crc plays a role in the development of antimicrobial-tolerant subpopulations in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Zhang, Lianbo; Chiang, Wen-Chi; Gao, Qingguo

    2012-01-01

    Bacteria form complex surface-attached biofilm communities in nature. Biofilm cells differentiate into subpopulations which display tolerance towards antimicrobial agents. However, the signal transduction pathways regulating subpopulation differentiation in biofilms are largely unelucidated. In t....... In the present study, we show that the catabolite repression control protein Crc regulates the metabolic state of Pseudomonas aeruginosa cells in biofilms, and plays an important role in the development of antimicrobial-tolerant subpopulations in P. aeruginosa biofilms....

  11. Isolation, identification and characterization of organic solvent tolerant protease from Bacillus sp. DAF-01

    Directory of Open Access Journals (Sweden)

    Arastoo Badoei-Dalfard

    2012-01-01

    Full Text Available Introduction: Organic solvent-tolerant bacteria are relatively novel extermophilic microorganisms, which can produce organic tolerant protease with capacity of being used in industrial biotechnology for producing high-value compounds. Therefore, finding of these bacteria has drawn much researchers attention nowadays. Materials and Methods: In this project, samples were collected from a hot spring, located in Jiroft. Samples were incubated in medium supplemented with cyclohexane and toluene for 3 days. Screening of protease producing bacteria was performed on the specific media, SKM (Skim milk agar, based on clear area diameter. The best bacterium was identified based on 16s rDNA gene. Protease activity was considered in different temperatures, pH and organic solvents.Results: Sequence alignment and phylogenetic tree results showed that this bacteria was closely related to Bacillus niacini, with 97% homology. Enzymatic studies showed that, this enzyme was active at a wide range of temperatures, 20-90 °C and it,s optimal activity was in 60 °C. In addition, maximum protease activity was obtained in the 8-9 range of pH, and optimal stability was also at pH 9.0. Protease activity in the presence of methanol, toluene, isopropanol, cyclohexane and DMF ‏showed that, remaining activity was at least 80% compared to the control (without organic solvent Discussion and Conclusion: Thermopilic capacity, being active in alkaline protease and high protease stability in the presence of organic solvents all herald a remarkable application for using in different industries.

  12. Role of the interplay between quorum sensing regulator VqsR and the Pseudomonas quinolone signal in mediating carbapenem tolerance in Pseudomonas aeruginosa.

    Science.gov (United States)

    Viducic, Darija; Murakami, Keiji; Amoh, Takashi; Ono, Tsuneko; Miyake, Yoichiro

    2017-06-01

    Pseudomonas aeruginosa coordinates its response to environmental conditions through activation of a quorum sensing (QS) system. In this study, we investigated the regulatory interaction between the QS transcriptional regulator VqsR and the Pseudomonas quinolone signal (PQS) through integration of sigma factor RpoS, and we addressed whether one of the pathways controlling carbapenem tolerance can be attributed to VqsR. We demonstrate that vqsR expression at the transcriptional level is regulated by pqsA, pqsR, and pqsE. Assessment of the transcriptional expression of vqsR, lasI, rhlI, and qscR in ΔpqsA and ΔpqsAΔrpoS mutants provided insight into pqsA- and rpoS-dependent regulation of vqsR and vqsR-controlled genes. Exogenously supplemented PQS reversed expression of vqsR and vqsR-controlled genes in the ΔpqsA mutant to wild-type levels, but failed to increase expression levels of lasI and qscR in the ΔpqsAΔrpoS mutant to levels observed in wild-type PAO1. The ΔvqsR mutant showed reduced survival when challenged with carbapenems compared to wild-type PAO1. Introduction of a pqsA mutation into the ΔvqsR mutant completely abolished its carbapenem-sensitive phenotype. We conclude that a regulatory link between PQS and vqsR exists, and that RpoS is important in their interaction. We also demonstrate that VqsR affects carbapenem tolerance. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  13. Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

    Science.gov (United States)

    Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

    2013-05-01

    In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.

  14. Differentiation and distribution of colistin- and sodium dodecyl sulfate-tolerant cells in Pseudomonas aeruginosa biofilms

    DEFF Research Database (Denmark)

    Haagensen, Janus Anders Juul; Klausen, M; Ernst, RK

    2007-01-01

    During Pseudomonas aeruginosa flow cell biofilm development, the cell population differentiates into a nonmotile subpopulation which forms microcolonies and a migrating subpopulation which eventually colonizes the top of the microcolonies, resulting in the development of mushroom-shaped multicell......During Pseudomonas aeruginosa flow cell biofilm development, the cell population differentiates into a nonmotile subpopulation which forms microcolonies and a migrating subpopulation which eventually colonizes the top of the microcolonies, resulting in the development of mushroom......-targeting antibacterial agents. All biofilm-associated cells were sensitive to the antibacterial agents when tested in standard plate assays. A mutation eliminating the production of type IV pili, and hence surface-associated motility, prevented the formation of regular mushroom-shaped structures in the flow cell...... that only the cap-forming subpopulation in biofilms treated with colistin expresses the pmr operon. These results suggest that increased antibiotic tolerance in biofilms may be a consequence of differentiation into distinct subpopulations with different phenotypic properties....

  15. An organic solvent-, detergent-, and thermo-stable alkaline protease from the mesophilic, organic solvent-tolerant Bacillus licheniformis 3C5.

    Science.gov (United States)

    Rachadech, W; Navacharoen, A; Ruangsit, W; Pongtharangkul, T; Vangnai, A S

    2010-01-01

    Bacillus licheniformis 3C5, isolated as mesophilic bacterium, exhibited tolerance towards a wide range of non-polar and polar organic solvents at 45 degrees C. It produced an extracellular organic solvent-stable protease with an apparent molecular mass of approximately 32 kDa. The inhibitory effect of PMSF and EDTA suggested it is likely to be an alkaline serine protease. The protease was active over abroad range of temperatures (45-70 degrees C) and pH (8-10) range with an optimum activity at pH 10 and 65 degrees C. It was comparatively stable in the presence ofa relatively high concentration (35% (v/v)) of organic solvents and various types of detergents even at a relatively high temperature (45 degrees C). The protease production by B. licheniformis 3C5 was growth-dependent. The optimization of carbon and nitrogen sources for cell growth and protease production revealed that yeast extract was an important medium component to support both cell growth and the protease production. The overall properties of the protease produced by B. licheniformis 3C5 suggested that this thermo-stable, solvent-stable, detergent-stable alkaline protease is a promising potential biocatalyst for industrial and environmental applications.

  16. Purification and Characterization of Organic Solvent and Detergent Tolerant Lipase from Thermotolerant Bacillus sp. RN2

    Directory of Open Access Journals (Sweden)

    Tadahiko Kajiwara

    2010-09-01

    Full Text Available The aim of this study was to characterize the organic solvent and detergent tolerant properties of recombinant lipase isolated from thermotolerant Bacillus sp. RN2 (Lip-SBRN2. The isolation of the lipase-coding gene was achieved by the use of inverse and direct PCR. The complete DNA sequencing of the gene revealed that the lip-SBRN2 gene contains 576 nucleotides which corresponded to 192 deduced amino acids. The purified enzyme was homogeneous with the estimated molecular mass of 19 kDa as determined by SDS-PAGE and gel filtration. The Lip-SBRN2 was stable in a pH range of 9–11 and temperature range of 45–60 °C. The enzyme was a non metallo-monomeric protein and was active against pNP-caprylate (C8 and pNP-laurate (C12 and coconut oil. The Lip-SBRN2 exhibited a high level of activity in the presence of 108% benzene, 102.4% diethylether and 112% SDS. It is anticipated that the organic solvent and detergent tolerant enzyme secreted by Bacillus sp. RN2 will be applicable as catalysts for reaction in the presence of organic solvents and detergents.

  17. The role of active-site Phe87 in modulating the organic co-solvent tolerance of cytochrome P450 BM3 monooxygenase

    International Nuclear Information System (INIS)

    Kuper, Jochen; Tee, Kang Lan; Wilmanns, Matthias; Roccatano, Danilo; Schwaneberg, Ulrich; Wong, Tuck Seng

    2012-01-01

    Active-site Phe87 of cytochrome P450 BM3 protects the haem from DMSO molecule, thereby conferring higher organic co-solvent tolerance. Understanding the effects of organic co-solvents on protein structure and function is pivotal to engineering enzymes for biotransformation in non-aqueous solvents. The effects of DMSO on the catalytic activity of cytochrome P450 BM3 have previously been investigated and the importance of Phe87 in its organic co-solvent tolerance was identified. To probe the DMSO inactivation mechanism and the functional role of Phe87 in modulating the organic co-solvent tolerance of P450 BM3, the haem domain (Thr1–Leu455) of the F87A variant was cocrystallized in the presence of 14%(v/v) and 28%(v/v) DMSO. At both DMSO concentrations the protein retained the canonical structure of the P450 haem domain without any sign of partial or global unfolding. Interestingly, a DMSO molecule was found in the active site of both structures, with its O atom pointing towards the haem iron. The orientation of the DMSO molecule indicated a dynamic coordination process that was in competition with the active-site water molecule. The ability of the DMSO molecule to coordinate the haem iron is plausibly the main reason why P450 BM3 is inactivated at elevated DMSO concentrations. The data allowed an interesting comparison with the wild-type structures reported previously. A DMSO molecule was found when the wild-type protein was placed in 28%(v/v) DMSO, in which the DMSO molecule coordinated the haem iron directly via its S atom. Intriguingly, no DMSO molecule was observed at 14%(v/v) DMSO for the wild-type structure. These results suggested that the bulky phenyl side chain of Phe87 protects the haem from being accessed by the DMSO molecule and explains the higher tolerance of the wild-type enzyme towards organic co-solvents compared with its F87A variant

  18. Comprehensive proteome analysis of the response of Pseudomonas putida KT2440 to the flavor compound vanillin.

    Science.gov (United States)

    Simon, Oliver; Klaiber, Iris; Huber, Armin; Pfannstiel, Jens

    2014-09-23

    Understanding of the molecular response of bacteria to precursors, products and environmental conditions applied in bioconversions is essential for optimizing whole-cell biocatalysis. To investigate the molecular response of the potential biocatalyst Pseudomonas putida KT2440 to the flavor compound vanillin we applied complementary gel- and LC-MS-based quantitative proteomics approaches. Our comprehensive proteomics survey included cytoplasmic and membrane proteins and led to the identification and quantification of 1614 proteins, corresponding to 30% of the total KT2440 proteome. 662 proteins were altered in abundance during growth on vanillin as sole carbon source as compared to growth on glucose. The proteome response entailed an increased abundance of enzymes involved in vanillin degradation, significant changes in central energy metabolism and an activation of solvent tolerance mechanisms. With respect to vanillin metabolism, particularly enzymes belonging to the β-ketoadipate pathway including a transcriptional regulator and porins specific for vanillin uptake increased in abundance. However, catabolism of vanillin was not dependent on vanillin dehydrogenase (Vdh), as shown by quantitative proteome analysis of a Vdh-deficient KT2440 mutant (GN235). Other aldehyde dehydrogenases that were significantly increased in abundance in response to vanillin may replace Vdh and thus may represent interesting targets for improving vanillin production in P. putida KT2440. The high demand for the flavor compound vanillin by the food and fragrance industry makes natural vanillin from vanilla pods a scarce and expensive resource rendering its biotechnological production economically attractive. Pseudomonas bacteria are metabolically very versatile and accept a broad range of hydrocarbons as carbon source making them suitable candidates for bioconversion processes. This work describes the impact of vanillin on the metabolism of the reference strain P. putida KT2440 on a

  19. 40 CFR 180.1107 - Delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas...

    Science.gov (United States)

    2010-07-01

    ... thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety kurstaki encapsulated into killed Pseudomonas fluorescens is exempt from the...

  20. 40 CFR 180.1108 - Delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas...

    Science.gov (United States)

    2010-07-01

    ... thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens; exemption from the requirement... into killed Pseudomonas fluorescens; exemption from the requirement of a tolerance. The delta endotoxin of Bacillus thuringiensis variety San Diego encapsulated into killed Pseudomonas fluorescens is...

  1. Quantitative approach to track lipase producing Pseudomonas sp. S1 in nonsterilized solid state fermentation.

    Science.gov (United States)

    Sahoo, R K; Subudhi, E; Kumar, M

    2014-06-01

    Proliferation of the inoculated Pseudomonas sp. S1 is quantitatively evaluated using ERIC-PCR during the production of lipase in nonsterile solid state fermentation an approach to reduce the cost of enzyme production. Under nonsterile solid state fermentation with olive oil cake, Pseudomonas sp. S1 produced 57·9 IU g(-1) of lipase. DNA fingerprints of unknown bacterial isolates obtained on Bushnell Haas agar (BHA) + tributyrin exactly matched with that of Pseudomonas sp. S1. Using PCR-based enumeration, population of Pseudomonas sp. S1 was proliferated from 7·6 × 10(4) CFU g(-1) after 24 h to 4·6 × 10(8) CFU g(-1) after 96 h, which tallied with the maximum lipase activity as compared to control. Under submerged fermentation (SmF), Pseudomonas sp. S1 produced maximum lipase (49 IU ml(-1) ) using olive oil as substrate, while lipase production was 9·754 IU ml(-1) when Pseudomonas sp. S1 was grown on tributyrin. Optimum pH and temperature of the crude lipase was 7·0 and 50°C. Crude enzyme activity was 71·2% stable at 50°C for 360 min. Pseudomonas sp. S1 lipase was also stable in methanol showing 91·6% activity in the presence of 15% methanol, whereas 75·5 and 51·1% of activity were retained in the presence of 20 and 30% methanol, respectively. Thus, lipase produced by Pseudomonas sp. S1 is suitable for the production of biodiesel as well as treatment of oily waste water. This study presents the first report on the production of thermophilic organic solvent tolerant lipase using agro-industry waste in nonsterile solid state fermentation. Positive correlation between survival of Pseudomonas sp. S1 and lipase production under nonsterile solid state fermentation was established, which may emphasize the need to combine molecular tools and solid state fermentation in future studies. Our study brings new insights into the lipase production in cost-effective manner, which is an industrially relevant approach. © 2014 The Society for Applied Microbiology.

  2. The MerR-like regulator BrlR confers biofilm tolerance by activating multidrug efflux pumps in Pseudomonas aeruginosa biofilms.

    Science.gov (United States)

    Liao, Julie; Schurr, Michael J; Sauer, Karin

    2013-08-01

    A defining characteristic of biofilms is antibiotic tolerance that can be up to 1,000-fold greater than that of planktonic cells. In Pseudomonas aeruginosa, biofilm tolerance to antimicrobial agents requires the biofilm-specific MerR-type transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm tolerance has not been elucidated. Genome-wide transcriptional profiling indicated that brlR was required for maximal expression of genes associated with antibiotic resistance, in particular those encoding the multidrug efflux pumps MexAB-OprM and MexEF-OprN. Chromatin immunoprecipitation (ChIP) analysis revealed a direct regulation of these genes by BrlR, with DNA binding assays confirming BrlR binding to the promoter regions of the mexAB-oprM and mexEF-oprN operons. Quantitative reverse transcriptase PCR (qRT-PCR) analysis further indicated BrlR to be an activator of mexAB-oprM and mexEF-oprN gene expression. Moreover, immunoblot analysis confirmed increased MexA abundance in cells overexpressing brlR. Inactivation of both efflux pumps rendered biofilms significantly more susceptible to five different classes of antibiotics by affecting MIC but not the recalcitrance of biofilms to killing by bactericidal agents. Overexpression of either efflux pump in a ΔbrlR strain partly restored tolerance of ΔbrlR biofilms to antibiotics. Expression of brlR in mutant biofilms lacking both efflux pumps partly restored antimicrobial tolerance of biofilms to wild-type levels. Our results indicate that BrlR acts as an activator of multidrug efflux pumps to confer tolerance to P. aeruginosa biofilms and to resist the action of antimicrobial agents.

  3. DNA Polymerases ImuC and DinB Are Involved in DNA Alkylation Damage Tolerance in Pseudomonas aeruginosa and Pseudomonas putida.

    Science.gov (United States)

    Jatsenko, Tatjana; Sidorenko, Julia; Saumaa, Signe; Kivisaar, Maia

    2017-01-01

    Translesion DNA synthesis (TLS), facilitated by low-fidelity polymerases, is an important DNA damage tolerance mechanism. Here, we investigated the role and biological function of TLS polymerase ImuC (former DnaE2), generally present in bacteria lacking DNA polymerase V, and TLS polymerase DinB in response to DNA alkylation damage in Pseudomonas aeruginosa and P. putida. We found that TLS DNA polymerases ImuC and DinB ensured a protective role against N- and O-methylation induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in both P. aeruginosa and P. putida. DinB also appeared to be important for the survival of P. aeruginosa and rapidly growing P. putida cells in the presence of methyl methanesulfonate (MMS). The role of ImuC in protection against MMS-induced damage was uncovered under DinB-deficient conditions. Apart from this, both ImuC and DinB were critical for the survival of bacteria with impaired base excision repair (BER) functions upon alkylation damage, lacking DNA glycosylases AlkA and/or Tag. Here, the increased sensitivity of imuCdinB double deficient strains in comparison to single mutants suggested that the specificity of alkylated DNA lesion bypass of DinB and ImuC might also be different. Moreover, our results demonstrated that mutagenesis induced by MMS in pseudomonads was largely ImuC-dependent. Unexpectedly, we discovered that the growth temperature of bacteria affected the efficiency of DinB and ImuC in ensuring cell survival upon alkylation damage. Taken together, the results of our study disclosed the involvement of ImuC in DNA alkylation damage tolerance, especially at low temperatures, and its possible contribution to the adaptation of pseudomonads upon DNA alkylation damage via increased mutagenesis.

  4. Antimicrobial Tolerance of Pseudomonas aeruginosa Biofilms Is Activated during an Early Developmental Stage and Requires the Two-Component Hybrid SagS

    Science.gov (United States)

    Gupta, Kajal; Marques, Cláudia N. H.; Petrova, Olga E.

    2013-01-01

    A hallmark characteristic of biofilms is their extraordinary tolerance to antimicrobial agents. While multiple factors are thought to contribute to the high level of antimicrobial tolerance of biofilms, little is known about the timing of induction of biofilm tolerance. Here, we asked when over the course of their development do biofilms gain their tolerance to antimicrobial agents? We demonstrate that in Pseudomonas aeruginosa, biofilm tolerance is linked to biofilm development, with transition to the irreversible attachment stage regulated by the two-component hybrid SagS, marking the timing when biofilms switch to the high-level tolerance phenotype. Inactivation of sagS rendered biofilms but not planktonic cells more susceptible to tobramycin, norfloxacin, and hydrogen peroxide. Moreover, inactivation of sagS also eliminated the recalcitrance of biofilms to killing by bactericidal antimicrobial agents, a phenotype comparable to that observed upon inactivation of brlR, which encodes a MerR-like transcriptional regulator required for biofilm tolerance. Multicopy expression of brlR in a ΔsagS mutant restored biofilm resistance and recalcitrance to killing by bactericidal antibiotics to wild-type levels. In contrast, expression of sagS did not restore the susceptibility phenotype of ΔbrlR mutant biofilms to wild-type levels, indicating that BrlR functions downstream of SagS. Inactivation of sagS correlated with reduced BrlR levels in biofilms, with the produced BrlR being impaired in binding to the previously described BrlR-activated promoters of the two multidrug efflux pump operons mexAB-oprM and mexEF-oprN. Our findings demonstrate that biofilm tolerance is linked to early biofilm development and SagS, with SagS contributing indirectly to BrlR activation. PMID:23995639

  5. PRODUCTION AND CHARACTERIZATION OF AN ALKALOTHERMOSTABLE, ORGANIC SOLVENT TOLERANT AND SURFACTANT TOLERANT ESTERASE PRODUCED BY A THERMOPHILIC BACTERIUM GEOBACILLUS SP. AGP-04, ISOLATED FROM BAKRESHWAR HOT SPRING, INDIA

    Directory of Open Access Journals (Sweden)

    Amit Ghati

    2013-10-01

    Full Text Available A thermophilic bacteria, Geobacillus sp. AGP-04, isolated from Surya Kund hot spring, Bakreshwar, West Bengal, India was studied in terms of capability of tributyrin hydrolysis and characterization of its thermostable esterase activity using p-nitrophenyl butyrate (PNPB as substrate. The extracellular crude preparation was characterized in terms of pH and temperature optima and stability, organic solvent tolerance capacity and stability, substrate specificity, surfactant tolerance capacity, kinetic parameters and activation/inhibition behavior towards some metal ions and chemicals. Tributyrin agar assay exhibited that Geobacillus sp. AGP-04 secretes an extracellular esterase. The Vmax and Km values of the esterase were found to be 5099 U/Land 103.5µM, respectively in the presence of PNPB as substrate. The optimum temperature and pH, for Geobacillus sp. AGP-04 esterase was 60oC and 8.0, respectively. Although the enzyme activity was not significantly altered by incubating crude extract solution at 20-70oC for 1 hour, the enzyme activity was fully lost at 90oC for same incubation period. The pH stability profile showed that original crude esterase activity is stable at a broad range (pH 5.0-10.0. Moreover, the enzyme was highly organic solvent and surfactant tolerant. The effect of some chemical on crude esterase activity indicated that Geobacillus sp. AGP-04 produce an esterase which contains a serine residue in active site and for its activity -SH groups are essential. Besides, enzyme production was highly induced if fermentation medium contain polysaccharides and oil as carbon source.

  6. A facile solvent-free Synthesis Route for the Assembly of Highly CO2 Selective and H2S tolerant NiSIFSIX Metal-Organic Framework

    KAUST Repository

    Eddaoudi, Mohamed; Shekhah, Osama; Belmabkhout, Youssef; Adil, Karim; Cairns, Amy J.; Bhatt, Prashant

    2015-01-01

    The development of materials for CO2 capture with high selectivity and high tolerance to H2S is of prime importance for various industrially relevant gas streams (e.g. natural gas and biogas upgrading as well as pre-combustion capture). Here, we report the successful fabrication of a MOF with combined exceptional CO2 capture properties and H2S tolerance, namely Ni SIFSIX based-MOF using both solvothermal and solvent-free methodologies.

  7. A facile solvent-free Synthesis Route for the Assembly of Highly CO2 Selective and H2S tolerant NiSIFSIX Metal-Organic Framework

    KAUST Repository

    Eddaoudi, Mohamed

    2015-07-06

    The development of materials for CO2 capture with high selectivity and high tolerance to H2S is of prime importance for various industrially relevant gas streams (e.g. natural gas and biogas upgrading as well as pre-combustion capture). Here, we report the successful fabrication of a MOF with combined exceptional CO2 capture properties and H2S tolerance, namely Ni SIFSIX based-MOF using both solvothermal and solvent-free methodologies.

  8. The ABC of Biofilm Drug Tolerance: the MerR-Like Regulator BrlR Is an Activator of ABC Transport Systems, with PA1874-77 Contributing to the Tolerance of Pseudomonas aeruginosa Biofilms to Tobramycin.

    Science.gov (United States)

    Poudyal, Bandita; Sauer, Karin

    2018-02-01

    A hallmark of biofilms is their tolerance to killing by antimicrobial agents. In Pseudomonas aeruginosa , biofilm drug tolerance requires the c-di-GMP-responsive MerR transcriptional regulator BrlR. However, the mechanism by which BrlR mediates biofilm drug tolerance has not been elucidated. Here, we demonstrate that BrlR activates the expression of at least 7 ABC transport systems, including the PA1874-PA1875-PA1876-PA1877 (PA1874-77) operon, with chromatin immunoprecipitation and DNA binding assays confirming BrlR binding to the promoter region of PA1874-77. Insertional inactivation of the 7 ABC transport systems rendered P. aeruginosa PAO1 biofilms susceptible to tobramycin or norfloxacin. Susceptibility was linked to drug accumulation, with BrlR contributing to norfloxacin accumulation in a manner dependent on multidrug efflux pumps and the PA1874-77 ABC transport system. Inactivation of the respective ABC transport system, furthermore, eliminated the recalcitrance of biofilms to killing by tobramycin but not norfloxacin, indicating that drug accumulation is not linked to biofilm drug tolerance. Our findings indicate for the first time that BrlR, a MerR-type transcriptional activator, activates genes encoding several ABC transport systems, in addition to multiple multidrug efflux pump genes. Moreover, our data confirm a BrlR target contributing to drug tolerance, likely countering the prevailing dogma that biofilm tolerance arises from a multiplicity of factors. Copyright © 2018 American Society for Microbiology.

  9. Reverting antibiotic tolerance of Pseudomonas aeruginosa PAO1 persister cells by (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one.

    Directory of Open Access Journals (Sweden)

    Jiachuan Pan

    Full Text Available BACKGROUND: Bacteria are well known to form dormant persister cells that are tolerant to most antibiotics. Such intrinsic tolerance also facilitates the development of multidrug resistance through acquired mechanisms. Thus persister cells are a promising target for developing more effective methods to control chronic infections and help prevent the development of multidrug-resistant bacteria. However, control of persister cells is still an unmet challenge. METHODOLOGY/PRINCIPAL FINDINGS: We show in this report that (Z-4-bromo-5-(bromomethylene-3-methylfuran-2(5H-one (BF8 can restore the antibiotic susceptibility of Pseudomonas aeruginosa PAO1 persister cells at growth non-inhibitory concentrations. Persister control by BF8 was found to be effective against both planktonic and biofilm cells of P. aeruginosa PAO1. Interestingly, although BF8 is an inhibitor of quorum sensing (QS in Gram-negative bacteria, the data in this study suggest that the activities of BF8 to revert antibiotic tolerance of P. aeruginosa PAO1 persister cells is not through QS inhibition and may involve other targets. CONCLUSION: BF8 can sensitize P. aeruginosa persister cells to antibiotics.

  10. Isolation of butanol- and isobutanol-tolerant bacteria and physiological characterization of their butanol tolerance.

    Science.gov (United States)

    Kanno, Manabu; Katayama, Taiki; Tamaki, Hideyuki; Mitani, Yasuo; Meng, Xian-Ying; Hori, Tomoyuki; Narihiro, Takashi; Morita, Naoki; Hoshino, Tamotsu; Yumoto, Isao; Kimura, Nobutada; Hanada, Satoshi; Kamagata, Yoichi

    2013-11-01

    Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified thus far. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) butanol and isobutanol were isolated. A 16S rRNA gene sequencing analysis revealed that the isolates were phylogenetically distributed over at least nine genera: Bacillus, Lysinibacillus, Rummeliibacillus, Brevibacillus, Coprothermobacter, Caloribacterium, Enterococcus, Hydrogenoanaerobacterium, and Cellulosimicrobium, within the phyla Firmicutes and Actinobacteria. Ten of the isolates were phylogenetically distinct from previously identified butanol-tolerant bacteria. Two relatively highly butanol-tolerant strains CM4A (aerobe) and GK12 (obligate anaerobe) were characterized further. Both strains changed their membrane fatty acid composition in response to butanol exposure, i.e., CM4A and GK12 exhibited increased saturated and cyclopropane fatty acids (CFAs) and long-chain fatty acids, respectively, which may serve to maintain membrane fluidity. The gene (cfa) encoding CFA synthase was cloned from strain CM4A and expressed in Escherichia coli. The recombinant E. coli showed relatively higher butanol and isobutanol tolerance than E. coli without the cfa gene, suggesting that cfa can confer solvent tolerance. The exposure of strain GK12 to butanol by consecutive passages even enhanced the growth rate, indicating that yet-unknown mechanisms may also contribute to solvent tolerance. Taken together, the results demonstrate that a wide variety of butanol- and isobutanol-tolerant bacteria that can grow in 2.0% butanol exist in the environment and have various strategies to maintain structural integrity against detrimental solvents.

  11. Transcriptome Analysis of Induced Systemic Drought Tolerance Elicited by Pseudomonas chlororaphis O6 in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Song-Mi Cho

    2013-06-01

    Full Text Available Root colonization by Pseudomonas chlororaphis O6 induces systemic drought tolerance in Arabidopsis thaliana. Microarray analysis was performed using the 22,800-gene Affymetrix GeneChips to identify differentially-expressed genes from plants colonized with or without P. chlororaphis O6 under drought stressed conditions or normal growth conditions. Root colonization in plants grown under regular irrigation condition increased transcript accumulation from genes associated with defense, response to reactive oxygen species, and auxin- and jasmonic acid-responsive genes, but decreased transcription factors associated with ethylene and abscisic acid signaling. The cluster of genes involved in plant disease resistance were up-regulated, but the set of drought signaling response genes were down-regulated in the P. chlororaphis O6-colonized under drought stress plants compared to those of the drought stressed plants without bacterial treatment. Transcripts of the jasmonic acid-marker genes, VSP1 and pdf-1.2, the salicylic acid regulated gene, PR-1, and the ethylene-response gene, HEL, also were up-regulated in plants colonized by P. chlororaphis O6, but differed in their responsiveness to drought stress. These data show how gene expression in plants lacking adequate water can be remarkably influenced by microbial colonization leading to plant protection, and the activation of the plant defense signal pathway induced by root colonization of P. chlororaphis O6 might be a key element for induced systemic tolerance by microbes.

  12. Involvement of the TonB system in tolerance to solvents and drugs in Pseudomonas putida DOT-T1E.

    Science.gov (United States)

    Godoy, P; Ramos-González, M I; Ramos, J L

    2001-09-01

    Pseudomonas putida DOT-T1E is able to grow with glucose as the carbon source in liquid medium with 1% (vol/vol) toluene or 17 g of (123 mM) p-hydroxybenzoate (4HBA) per liter. After random mini-Tn5'phoA-Km mutagenesis, we isolated the mutant DOT-T1E-PhoA5, which was more sensitive than the wild type to 4HBA (growth was prevented at 6 g/liter) and toluene (the mutant did not withstand sudden toluene shock). Susceptibility to toluene and 4HBA resulted from the reduced efflux of these compounds from the cell, as revealed by accumulation assays with (14)C-labeled substrates. The mutant was also more susceptible to a number of antibiotics, and its growth in iron-deficient minimal medium was inhibited in the presence of ethylenediamine-di(o-hydroxyphenylacetic acid (EDDHA). Cloning the mutation in the PhoA5 strain and sequencing the region adjacent showed that the mini-Tn5 transposor interrupted the exbD gene, which forms part of the exbBD tonB operon. Complementation by the exbBD and tonB genes cloned in pJB3-Tc restored the wild-type characteristics to the PhoA5 strain.

  13. Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism

    Science.gov (United States)

    2016-03-15

    RESEARCH ARTICLE Biofilm Formation Mechanisms of Pseudomonas aeruginosa Predicted via Genome-Scale Kinetic Models of Bacterial Metabolism Francisco G...jaques.reifman.civ@mail.mil Abstract A hallmark of Pseudomonas aeruginosa is its ability to establish biofilm -based infections that are difficult to...eradicate. Biofilms are less susceptible to host inflammatory and immune responses and have higher antibiotic tolerance than free-living planktonic

  14. Antibiotic tolerance and microbial biofilms

    DEFF Research Database (Denmark)

    Folkesson, Anders

    Increased tolerance to antimicrobial agents is thought to be an important feature of microbes growing in biofilms. We study the dynamics of antibiotic action within hydrodynamic flow chamber biofilms of Escherichia coli and Pseudomonas aeruginosa using isogenic mutants and fluorescent gene...... expression reporters and we address the question of how biofilm organization affects antibiotic susceptibility. The dynamics of microbial killing is monitored by viable count determination, and confocal laser microscopy. Our work shows that the apparent increased antibiotic tolerance is due to the formation...... of antibiotic tolerant subpopulations within the biofilm. The formation of these subpopulations is highly variable and dependent on the antibiotic used, the biofilm structural organization and the induction of specific tolerance mechanisms....

  15. Regulation of Nicotine Tolerance by Quorum Sensing and High Efficiency of Quorum Quenching Under Nicotine Stress in Pseudomonas aeruginosa PAO1

    Directory of Open Access Journals (Sweden)

    Huiming Tang

    2018-03-01

    Full Text Available Quorum sensing (QS regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ, the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT and ΔrhlR strains are significantly higher than those in the ΔlasR strain. Supplementation of ΔlasI strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in P. aeruginosa. This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.

  16. Regulation of Nicotine Tolerance by Quorum Sensing and High Efficiency of Quorum Quenching Under Nicotine Stress in Pseudomonas aeruginosa PAO1.

    Science.gov (United States)

    Tang, Huiming; Zhang, Yunyun; Ma, Yifan; Tang, Mengmeng; Shen, Dongsheng; Wang, Meizhen

    2018-01-01

    Quorum sensing (QS) regulates the behavior of bacterial populations and promotes their adaptation and survival under stress. As QS is responsible for the virulence of vast majority of bacteria, quorum quenching (QQ), the interruption of QS, has become an attractive therapeutic strategy. However, the role of QS in stress tolerance and the efficiency of QQ under stress in bacteria are seldom explored. In this study, we demonstrated that QS-regulated catalase (CAT) expression and biofilm formation help Pseudomonas aeruginosa PAO1 resist nicotine stress. CAT activity and biofilm formation in wild type (WT) and Δ rhlR strains are significantly higher than those in the Δ lasR strain. Supplementation of Δ lasI strain with 3OC12-HSL showed similar CAT activity and biofilm formation as those of the WT strain. LasIR circuit rather than RhlIR circuit is vital to nicotine tolerance. Acylase I significantly decreased the production of virulence factors, namely elastase, pyocyanin, and pyoverdine under nicotine stress compared to the levels observed in the absence of nicotine stress. Thus, QQ is more efficient under stress. To our knowledge, this is the first study to report that QS contributes to nicotine tolerance in P. aeruginosa . This work facilitates a better application of QQ for the treatment of bacterial infections, especially under stress.

  17. Production, Optimization, and Characterization of Organic Solvent Tolerant Cellulases from a Lignocellulosic Waste-Degrading Actinobacterium, Promicromonospora sp. VP111.

    Science.gov (United States)

    Thomas, Lebin; Ram, Hari; Kumar, Alok; Singh, Ved Pal

    2016-07-01

    High costs of natural cellulose utilization and cellulase production are an industrial challenge. In view of this, an isolated soil actinobacterium identified as Promicromonospora sp. VP111 showed potential for production of major cellulases (CMCase, FPase, and β-glucosidase) utilizing untreated agricultural lignocellulosic wastes. Extensive disintegration of microcrystalline cellulose and adherence on it during fermentation divulged true cellulolytic efficiency of the strain. Conventional optimization resulted in increased cellulase yield in a cost-effective medium, and the central composite design (CCD) analysis revealed cellulase production to be limited by cellulose and ammonium sulfate. Cellulase activities were enhanced by Co(+2) (1 mM) and retained up to 60 °C and pH 9.0, indicating thermo-alkaline tolerance. Cellulases showed stability in organic solvents (25 % v/v) with log P ow  ≥ 1.24. Untreated wheat straw during submerged fermentation was particularly degraded and yielded about twofold higher levels of cellulases than with commercial cellulose (Na-CMC and avicel) which is especially economical. Thus, this is the first detailed report on cellulases from an efficient strain of Promicromonospora that was non-hemolytic, alkali-halotolerant, antibiotic (erythromycin, kanamycin, rifampicin, cefaclor, ceftazidime) resistant, multiple heavy metal (Mo(+6) = W(+6) > Pb(+2) > Mn(+2) > Cr(+3) > Sn(+2)), and organic solvent (n-hexane, isooctane) tolerant, which is industrially and environmentally valuable.

  18. Purification and characterization of an extracellular halophilic and organic solvent-tolerant amylopullulanase from a haloarchaeon, Halorubrum sp. strain Ha25.

    Directory of Open Access Journals (Sweden)

    Mostafa Fazeli

    2013-01-01

    Full Text Available Introduction: Halophiles, especially haloarchaea are one of the most important groups of extremophiles. Halophilic hydrolases have been studied worldwide and have been considered for biotechnology and industrial technologies. This study is the first report in amylopullulanase production in halophilic microorganisms.Materials and methods: A halophilic archaeon, Halorubrum sp. strain Ha25, produced extracellular halophilic organic solvent-tolerant amylopullulanase. The enzyme was purified using ethanol precipitation and anion exchange chromatography method. Molecular mass of purified enzyme was determined by SDS–PAGE method. After purification, the enzyme was characterized. To study the effects of organic solvents in the stability of the enzyme, the enzyme solution was incubated in the presence of various organic compounds and then, residual enzyme activity was measured. Mode of action of the enzyme was determined by thin-layer chromatography.Results: Molecular weight of the purified enzyme was estimated to be 140 kDa by SDS–PAGE method. Optimum temperature for amylolitic and pullulytic activities was 50 °C. Optimum pH for amylolitic activity was 7.0 and for pullulytic activity was 7.5. This enzyme was active over a wide range of concentrations (0-4.5 M of NaCl. The effect of organic solvents on the amylolitic and pullulytic activities showed that this enzyme was more stable in the presence of non-polar organic solvents than polar solvents. The enzyme solely hydrolyzed pullulan and soluble starch to glucose.Discussion and conclusion: Halorubrum sp. strain Ha25 produces thermophilic and extremely halophilic amylopullulanase. The catalytic function under multi extreme condition of high temperature, high salinity, and low water activity might possess biotechnological and commercial values such as treatment waste solutions with starch residues, high salt content and solvents.

  19. Solvents, Ethanol, Car Crashes and Tolerance: How Risky is Inhalation of Organic Solvents?

    Science.gov (United States)

    A research program in the National Health and Environmental Effects Research Laboratory of the U.S. EPA has led to some surprising considerations regarding the potential hazard of exposure to low concentrations of solvent vapors. This program involved conducting experiments to ch...

  20. 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?

  1. Core Flood study for enhanced oil recovery through ex-situ bioaugmentation with thermo- and halo-tolerant rhamnolipid produced by Pseudomonas aeruginosa NCIM 5514.

    Science.gov (United States)

    Varjani, Sunita J; Upasani, Vivek N

    2016-11-01

    The aim of this work was to study the Microbial Enhanced Oil Recovery (MEOR) employing core field model ex-situ bioaugmenting a thermo- and halo-tolerant rhamnolipid produced by Pseudomonas aeruginosa. Thin Layer Chromatography (TLC) revealed that the biosurfactant produced was rhamnolipid type. Nuclear Magnetic Resonance analysis showed that the purified rhamnolipids comprised two principal rhamnolipid homologues, i.e., Rha-Rha-C10-C14:1 and Rha-C8-C10. The rhamnolipid was stable under wide range of temperature (4°C, 30-100°C), pH (2.0-10.0) and NaCl concentration (0-18%, w/v). Core Flood model was designed for oil recovery operations using rhamnolipid. The oil recovery enhancement over Residual Oil Saturation was 8.82% through ex-situ bioaugmentation with rhamnolipid. The thermal stability of rhamnolipid shows promising scope for its application at conditions where high temperatures prevail in oil recovery processes, whereas its halo-tolerant nature increases its application in marine environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Fluorescence-Based Reporter for Gauging Cyclic Di-GMP Levels in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Rybtke, Morten T.; Borlee, Bradley R.; Murakami, Keiji

    2012-01-01

    The increased tolerance toward the host immune system and antibiotics displayed by biofilm-forming Pseudomonas aeruginosa and other bacteria in chronic infections such as cystic fibrosis bronchopneumonia is of major concern. Targeting of biofilm formation is believed to be a key aspect in the dev...

  3. Atrazine- tolerant native microorganisms isolated from agricultural soils in the department of Cordoba, Colombia

    Directory of Open Access Journals (Sweden)

    Luis Oviedo Z

    2017-05-01

    Full Text Available The objective of the present study was to identify and evaluate atrazine tolerant native microorganisms isolated from a soil destined to the maize crop for ensiling, where this pesticide is usually used as preemergence. To determine their tolerance, they were subjected to growth at different concentrations of atrazine, different temperatures (30 ° C, 37 ° C and 40 ° C and pH (5.0, 6.0 and 9.0. The results show native strains that tolerated concentrations of 1000 ppm atrazine, identified as Pseudomonas sp (strain 1L1a, Pseudomona sp (strain 1L2, Streptomyces sp and Arthrobacterium sp, which show higher growth at 37 °C (7. 98E+06 CFU/mL, lower at 30 °C (3.63E+06 CFU/mL and tolerance at 40 °C (5.80E+06 CFU/mL. The strain Streptomyces sp reached its highest growth (4.73E+06 UFC/mL at pH 9.0, while Pseudomonas sp strain 1L1a (3.43E+06 UFC/mL, Arthrobacter sp (3.40E+06 UFC/mL and Pseudomonas sp strain 1L2a (2.63E+06 CFU/mL was at pH 6.0. All microorganisms showed sensitivity to pH 5.0. The growths reached at different temperatures and pH are in agreement with the adaptation to the tropical climate predominant in the region and related to the genus of microorganisms. The study indicates that the native strains are able to tolerate high concentrations of atrazine and to mineralize it in soils with low content of organic matter and nutrients.

  4. Homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8

    Directory of Open Access Journals (Sweden)

    Lawal Garba

    2018-03-01

    Full Text Available Membrane-bound fatty acid desaturases perform oxygenated desaturation reactions to insert double bonds within fatty acyl chains in regioselective and stereoselective manners. The Δ9-fatty acid desaturase strictly creates the first double bond between C9 and 10 positions of most saturated substrates. As the three-dimensional structures of the bacterial membrane fatty acid desaturases are not available, relevant information about the enzymes are derived from their amino acid sequences, site-directed mutagenesis and domain swapping in similar membrane-bound desaturases. The cold-tolerant Pseudomonas sp. AMS8 was found to produce high amount of monounsaturated fatty acids at low temperature. Subsequently, an active Δ9-fatty acid desaturase was isolated and functionally expressed in Escherichia coli. In this paper we report homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8 for the first time to the best of our knowledge. Three dimensional structure of the enzyme was built using MODELLER version 9.18 using a suitable template. The protein model contained the three conserved-histidine residues typical for all membrane-bound desaturase catalytic activity. The structure was subjected to energy minimization and checked for correctness using Ramachandran plots and ERRAT, which showed a good quality model of 91.6 and 65.0%, respectively. The protein model was used to preform MD simulation and docking of palmitic acid using CHARMM36 force field in GROMACS Version 5 and Autodock tool Version 4.2, respectively. The docking simulation with the lowest binding energy, −6.8 kcal/mol had a number of residues in close contact with the docked palmitic acid namely, Ile26, Tyr95, Val179, Gly180, Pro64, Glu203, His34, His206, His71, Arg182, Thr85, Lys98 and His177. Interestingly, among the binding residues are His34, His71 and His206 from the first, second, and third conserved histidine motif, respectively

  5. Biodegradation of propargite by Pseudomonas putida, isolated from tea rhizosphere.

    Science.gov (United States)

    Sarkar, Soumik; Seenivasan, Subbiah; Asir, Robert Premkumar Samuel

    2010-02-15

    Biodegradation of miticide propargite was carried out in vitro by selected Pseudomonas strains isolated from tea rhizosphere. A total number of 13 strains were isolated and further screened based on their tolerance level to different concentrations of propargite. Five best strains were selected and further tested for their nutritional requirements. Among the different carbon sources tested glucose exhibited the highest growth promoting capacity and among nitrogen sources ammonium nitrate supported the growth to the maximum. The five selected Pseudomonas strain exhibited a range of degradation capabilities. Mineral salts medium (MSM) amended with glucose provided better environment for degradation with the highest degradation potential in strain SPR 13 followed by SPR 8 (71.9% and 69.0% respectively).

  6. 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

  7. Interference of Pseudomonas aeruginosa signalling and biofilm formation for infection control

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Høiby, Niels

    2010-01-01

    Pseudomonas aeruginosa is the best described bacterium with regards to quorum sensing (QS), in vitro biofilm formation and the development of antibiotic tolerance. Biofilms composed of P. aeruginosa are thought to be the underlying cause of many chronic infections, including those in wounds...... and in the lungs of patients with cystic fibrosis. In this review, we provide an overview of the molecular mechanisms involved in QS, QS-enabled virulence, biofilm formation and biofilm-enabled antibiotic tolerance. We now have substantial knowledge of the multicellular behaviour of P. aeruginosa in vitro. A major...

  8. Spatial distributions of Pseudomonas fluorescens colony variants in mixed-culture biofilms.

    Science.gov (United States)

    Workentine, Matthew L; Wang, Siyuan; Ceri, Howard; Turner, Raymond J

    2013-07-28

    The emergence of colony morphology variants in structured environments is being recognized as important to both niche specialization and stress tolerance. Pseudomonas fluorescens demonstrates diversity in both its natural environment, the rhizosphere, and in laboratory grown biofilms. Sub-populations of these variants within a biofilm have been suggested as important contributors to antimicrobial stress tolerance given their altered susceptibility to various agents. As such it is of interest to determine how these variants might be distributed in the biofilm environment. Here we present an analysis of the spatial distribution of Pseudomonas fluorescens colony morphology variants in mixed-culture biofilms with the wildtype phenotype. These findings reveal that two variant colony morphotypes demonstrate a significant growth advantage over the wildtype morphotype in the biofilm environment. The two variant morphotypes out-grew the wildtype across the entire biofilm and this occurred within 24 h and was maintained through to 96 h. This competitive advantage was not observed in homogeneous broth culture. The significant advantage that the variants demonstrate in biofilm colonization over the wildtype denotes the importance of this phenotype in structured environments.

  9. Experimental investigation of activities and tolerance of denitrifying bacteria under alkaline and reducing condition

    International Nuclear Information System (INIS)

    Mine, Tatsuya; Mihara, Morihiro; Ooi, Takao

    2000-07-01

    In the geological disposal system of TRU wastes, nitrogen generation by denitrifying bacteria could provide significant impact on the assessment of this system, because nitrate contained in process concentrated liquid waste might be electron acceptor for denitrifying bacteria. In this study, the activities and tolerance of denitrifying under disposal condition were investigated. Pseudomonas denitrificans as denitrifying bacteria was used. The results showed that Pseudomonas denitrificans had activity under reducing condition, but under high pH condition (pH>9.5), the activity of Pseudomonas denitrificans was not detected. It is possible that the activity of Pseudomonas denitrificans would be low under disposal condition. (author)

  10. Immobilization of Pseudomonas fluorescens lipase on hydrophobic supports and application in biodiesel synthesis by transesterification of vegetable oils in solvent-free systems.

    Science.gov (United States)

    Lima, Lionete N; Oliveira, Gladson C; Rojas, Mayerlenis J; Castro, Heizir F; Da Rós, Patrícia C M; Mendes, Adriano A; Giordano, Raquel L C; Tardioli, Paulo W

    2015-04-01

    This work describes the preparation of biocatalysts for ethanolysis of soybean and babassu oils in solvent-free systems. Polystyrene, Amberlite (XAD-7HP), and octyl-silica were tested as supports for the immobilization of Pseudomonas fluorescens lipase (PFL). The use of octyl-silica resulted in a biocatalyst with high values of hydrolytic activity (650.0 ± 15.5 IU/g), immobilization yield (91.3 ± 0.3 %), and recovered activity (82.1 ± 1.5 %). PFL immobilized on octyl-silica was around 12-fold more stable than soluble PFL, at 45 °C and pH 8.0, in the presence of ethanol at 36 % (v/v). The biocatalyst provided high vegetable oil transesterification yields of around 97.5 % after 24 h of reaction using babassu oil and around 80 % after 48 h of reaction using soybean oil. The PFL-octyl-silica biocatalyst retained around 90 % of its initial activity after five cycles of transesterification of soybean oil. Octyl-silica is a promising support that can be used to immobilize PFL for subsequent application in biodiesel synthesis.

  11. Permeabilization and lysis of Pseudomonas pseudoalcaligenes cells by triton X-100 for efficient production of D-malate

    NARCIS (Netherlands)

    Werf, M.J. van der; Hartmans, S.; Tweel, W.J.J. van den

    1995-01-01

    Pseudomonas pseudoalcaligenes can only form d-malate from maleate after incubation of the cells with a solvent or a detergent. The effect of the detergent Triton X-100 on d-malate production was studied in more detail. The longer the cells were incubated with Triton X-100, the higher was the

  12. Reinforcement of the bactericidal effect of ciprofloxacin on Pseudomonas aeruginosa biofilm by hyperbaric oxygen treatment

    DEFF Research Database (Denmark)

    Kolpen, Mette; Mousavi, Nabi; Sams, Thomas

    2016-01-01

    Chronic Pseudomonas aeruginosa lung infection is the most severe complication in cystic fibrosis patients. It is characterised by antibiotic-tolerant biofilms in the endobronchial mucus with zones of oxygen (O2) depletion mainly due to polymorphonuclear leucocyte activity. Whilst the exact mechan...

  13. 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...

  14. Crystallization and preliminary X-ray diffraction analysis of alanine racemase from Pseudomonas putida YZ-26

    International Nuclear Information System (INIS)

    Liu, Junlin; Feng, Lei; Shi, Yawei; Feng, Wei

    2012-01-01

    A recombinant alanine racemase from the Pseudomonas putida YZ-26, has been crystallized by the sitting-drop vapor-diffusion method and X-ray diffraction data were collected to 2.4 Å. A recombinant form of alanine racemase (Alr) from Pseudomonas putida YZ-26 has been crystallized by the sitting-drop vapour diffusion method. X-ray diffraction data were collected to 2.4 Å resolution. The crystals belong to the space group C222 1 , with unit-cell parameters a = 118.08, b = 141.86, c = 113.83 Å, and contain an Alr dimer in the asymmetric unit. The Matthews coefficient and the solvent content were calculated to be 2.8 Å 3 Da −1 and approximately 50%, respectively

  15. Bacterial mediated amelioration of drought stress in drought tolerant ...

    African Journals Online (AJOL)

    yogendra

    2015-02-23

    Feb 23, 2015 ... for a beneficial effect of PGPRs application in enhancing drought tolerance of rice under water deficit conditions. ..... involvement of PGPRs in ROS metabolism in rice plants. ... osmoregulatory solute in plants (Kumar et al., 2011). ..... Pseudomonas fluorescens mediated saline resistance in groundnut.

  16. Supercritical CO2 extraction of Schinus molle L with co-solvents: mathematical modeling and antimicrobial applications

    Directory of Open Access Journals (Sweden)

    Rodrigo Scopel

    2013-06-01

    Full Text Available This work investigates the antimicrobial activity of the Schinus molle L. leaves extracts obtained under supercritical conditions using carbon dioxide and co-solvents. Antimicrobial qualitative evaluation was carried out through the bioautography technique and the microorganisms studied were Staphylococcus aureus, Pseudomonas aeruginosas, Escherichia coli, Micrococcus luteus, and Salmonella choleraesuis. The supercritical fluid extraction was carried out in a pilot scale equipment using carbon dioxide modified by the addition of co-solvents, such as ethanol and water at 150 bar and 333 K. A mathematical modeling of the process was also performed.

  17. Phenotypes of Non-Attached Pseudomonas aeruginosa Aggregates Resemble Surface Attached Biofilm

    DEFF Research Database (Denmark)

    Alhede, Morten; Kragh, Kasper Nørskov; Qvortrup, Klaus

    2011-01-01

    For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse......, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently...... were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both...

  18. Global transcriptional response of solvent-sensitive and solvent-tolerant Pseudomonas putida strains exposed to toluene

    DEFF Research Database (Denmark)

    Molina-Santiago, Carlos; Udaondo, Zulema; Gómez Lozano, María

    2017-01-01

    for the degradation and synthesis of a wide range of chemicals. For the use of these microbes in bioremediation and biocatalysis, it is critical to understand the mechanisms underlying these phenotypic differences. In this study, RNA-seq analysis compared the short- and long-term responses of the toluene-sensitive KT...... pathways, using toluene as source of energy. Among the unique genes encoded by DOT-T1E is a 70kb island composed of genes of unknown function induced in response to toluene....

  19. Micellar solutions of PEO-PPO-PEO block copolymers for in situ phenol removal from fermentation broth

    NARCIS (Netherlands)

    Heerema, L.D.; Cakali, D.; Roelands, C.P.M.; Goetheer, E.L.V.; Verdoes, D.; Keurentjes, J.

    2010-01-01

    The applicability of aqueous solutions of Pluronics for the removal of the model product phenol was evaluated. Phenol is a chemical that can be produced by a recombinant strain of the solvent tolerant bacterium Pseudomonas putida S12. However, the growth of the micro-organisms and the phenol

  20. Exploring Marine Environments To Unravel Tolerance Mechanisms To Relevant Compounds

    DEFF Research Database (Denmark)

    Machado, Henrique; Cavaleiro, Mafalda; Nørholm, Morten

    2015-01-01

    Production of biofuels and chemicals using microorganisms has been a research driver in the last decades. The approach started with the engineering of metabolic pathways for production of compounds of interest, but it was soon realized that tolerance to the compounds being produced was one...... of interest, HPLC analyses were performed in order to distinguish between compound-degrading and tolerant bacteria. This led to the identification of seven tolerant and non-degrading isolates, the most interesting ones belonging to the genera Bacillus and Pseudomonas. These will be studied using genomic...... and transcriptomic approaches to identify the tolerance mechanisms used. Exploring new ecological niches, as contaminated marine environments allows the identification of naturally tolerant bacteria to the compounds of interest and most likely to the discovery of new mechanisms of tolerance....

  1. Tolerance of Pseudomonas aeruginosa in in-vitro biofilms to high-level peracetic acid disinfection.

    Science.gov (United States)

    Akinbobola, A B; Sherry, L; Mckay, W G; Ramage, G; Williams, C

    2017-10-01

    Biofilm has been suggested as a cause of disinfection failures in flexible endoscopes where no lapses in the decontamination procedure can be identified. To test this theory, the activity of peracetic acid, one of the widely used disinfectants in the reprocessing of flexible endoscopes, was evaluated against both planktonic and sessile communities of Pseudomonas aeruginosa. To investigate the ability of P. aeruginosa biofilm to survive high-level peracetic acid disinfection. The susceptibility of planktonic cells of P. aeruginosa and biofilms aged 24, 48, 96, and 192 h to peracetic acid was evaluated by estimating their viability using resazurin viability and plate count methods. The biomass of the P. aeruginosa biofilms was also quantified using Crystal Violet assay. Planktonic cells of P. aeruginosa were treated with 5-30 ppm concentration of peracetic acid in the presence of 3.0 g/L of bovine serum albumin (BSA) for 5 min. Biofilms of P. aeruginosa were also treated with various peracetic acid concentrations (100-3000 ppm) for 5 min. Planktonic cells of P. aeruginosa were eradicated by 20 ppm of peracetic acid, whereas biofilms showed an age-dependent tolerance to peracetic acid, and 96 h biofilm was only eradicated at peracetic acid concentration of 2500 ppm. Ninety-six-hour P. aeruginosa biofilm survives 5 min treatment with 2000 ppm of peracetic acid, which is the working concentration used in some endoscope washer-disinfectors. This implies that disinfection failure of flexible endoscopes might occur when biofilms build up in the lumens of endoscopes. Copyright © 2017. Published by Elsevier Ltd.

  2. The impact of ColRS two-component system and TtgABC efflux pump on phenol tolerance of Pseudomonas putida becomes evident only in growing bacteria

    Directory of Open Access Journals (Sweden)

    Kivisaar Maia

    2010-04-01

    Full Text Available Abstract Background We have recently found that Pseudomonas putida deficient in ColRS two-component system is sensitive to phenol and displays a serious defect on solid glucose medium where subpopulation of bacteria lyses. The latter phenotype is significantly enhanced by the presence of phenol in growth medium. Here, we focused on identification of factors affecting phenol tolerance of the colR-deficient P. putida. Results By using transposon mutagenesis approach we identified a set of phenol-tolerant derivatives of colR-deficient strain. Surprisingly, half of independent phenol tolerant clones possessed miniTn5 insertion in the ttgABC operon. However, though inactivation of TtgABC efflux pump significantly enhanced phenol tolerance, it did not affect phenol-enhanced autolysis of the colR mutant on glucose medium indicating that phenol- and glucose-caused stresses experienced by the colR-deficient P. putida are not coupled. Inactivation of TtgABC pump significantly increased the phenol tolerance of the wild-type P. putida as well. Comparison of phenol tolerance of growing versus starving bacteria revealed that both ColRS and TtgABC systems affect phenol tolerance only under growth conditions and not under starvation. Flow cytometry analysis showed that phenol strongly inhibited cell division and to some extent also caused cell membrane permeabilization to propidium iodide. Single cell analysis of populations of the ttgC- and colRttgC-deficient strains revealed that their membrane permeabilization by phenol resembles that of the wild-type and the colR mutant, respectively. However, cell division of P. putida with inactivated TtgABC pump seemed to be less sensitive to phenol than that of the parental strain. At the same time, cell division appeared to be more inhibited in the colR-mutant strain than in the wild-type P. putida. Conclusions ColRS signal system and TtgABC efflux pump are involved in the phenol tolerance of P. putida. However, as

  3. Biosurfactant production by Pseudomonas strains isolated from floral nectar.

    Science.gov (United States)

    Ben Belgacem, Z; Bijttebier, S; Verreth, C; Voorspoels, S; Van de Voorde, I; Aerts, G; Willems, K A; Jacquemyn, H; Ruyters, S; Lievens, B

    2015-06-01

    To screen and identify biosurfactant-producing Pseudomonas strains isolated from floral nectar; to characterize the produced biosurfactants; and to investigate the effect of different carbon sources on biosurfactant production. Four of eight nectar Pseudomonas isolates were found to produce biosurfactants. Phylogenetic analysis based on three housekeeping genes (16S rRNA gene, rpoB and gyrB) classified the isolates into two groups, including one group closely related to Pseudomonas fluorescens and another group closely related to Pseudomonas fragi and Pseudomonas jessenii. Although our nectar pseudomonads were able to grow on a variety of water-soluble and water-immiscible carbon sources, surface active agents were only produced when using vegetable oil as sole carbon source, including olive oil, sunflower oil or waste frying sunflower oil. Structural characterization based on thin layer chromatography (TLC) and ultra high performance liquid chromatography-accurate mass mass spectrometry (UHPLC-amMS) revealed that biosurfactant activity was most probably due to the production of fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof. Four biosurfactant-producing nectar pseudomonads were identified. The active compounds were identified as fatty acids (C16:0; C18:0; C18:1 and C18:2), and mono- and diglycerides thereof, produced by hydrolysis of triglycerides of the feedstock. Studies on biosurfactant-producing micro-organisms have mainly focused on microbes isolated from soils and aquatic environments. Here, for the first time, nectar environments were screened as a novel source for biosurfactant producers. As nectars represent harsh environments with high osmotic pressure and varying pH levels, further screening of nectar habitats for biosurfactant-producing microbes may lead to the discovery of novel biosurfactants with broad tolerance towards different environmental conditions. © 2015 The Society for Applied Microbiology.

  4. Garlic as an inhibitor of Pseudomonas aeruginosa quorum sensing in cystic fibrosis--a pilot randomized controlled trial

    DEFF Research Database (Denmark)

    Smyth, Alan R; Cifelli, Paramita M; Ortori, Catharine A

    2010-01-01

    Pseudomonas aeruginosa forms biofilms in the cystic fibrosis lung. Quorum sensing (QS) controls biofilm maturation, immune evasion, antibiotic tolerance and virulence factor production. Garlic shows QS inhibitory activity in vitro and in animal models. We report the first clinical trial in man of...

  5. Mycobacterial Response to Organic Solvents and Possible Implications on Cross-Resistance With Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Cátia Pacífico

    2018-05-01

    Full Text Available Mycobacterium vaccae, a bacterium found in soil, has been receiving attention as adjuvant to antituberculosis treatment, vaccines and immunotherapies and even as antidepressant. This bacterium is also able to degrade several pollutants, including aromatic compounds. The increasing presence of organic solvents in the environment may lead to M. vaccae adapted populations. A possible relationship between solvent tolerance and decreased susceptibility to other types of chemicals, including antibiotics, may pose a problem during opportunistic infections. The present study thus aimed at assessing if solvent adapted cells presented higher tolerance to antibiotics and efflux pump inhibitors (EPIs. M. vaccae cells were able to thrive and grow in the presence of up 20% (v/v glycerol, 5% (v/v ethanol, 1% (v/v methyl tert-butyl ether (MTBE and 0.1% (v/v toluene. During adaptation to increasing concentration of ethanol and MTBE, the cells changed their fatty acid profile, zeta potential and morphology. Adapted cells acquired an improved tolerance toward the EPIs thioridazine and omeprazole, but became more susceptible to the antibiotics levofloxacin and teicoplanin when compared with non-adapted cells.

  6. Drought-Tolerant Plant Growth-Promoting Rhizobacteria Associated with Foxtail Millet in a Semi-arid Agroecosystem and Their Potential in Alleviating Drought Stress

    Directory of Open Access Journals (Sweden)

    Xuguang Niu

    2018-01-01

    Full Text Available The application of plant growth promoting rhizobacteria (PGPR to agro-ecosystems is considered to have the potential for improving plant growth in extreme environments featured by water shortage. Herein, we isolated bacterial strains from foxtail millet (Setaria italica L., a drought-tolerant crop cultivated in semiarid regions in the northeast of China. Four isolates were initially selected for their ability to produce ACC deaminase as well as drought tolerance. The isolates were identified as Pseudomonas fluorescens, Enterobacter hormaechei, and Pseudomonas migulae on the basis of 16S rRNA sequence analysis. All of these drought-tolerant isolates were able to produce EPS (exopolysaccharide. Inoculation with these strains stimulated seed germination and seedling growth under drought stress. Pseudomonas fluorescens DR7 showed the highest level of ACC deaminase and EPS-producing activity. DR7 could efficiently colonize the root adhering soil, increased soil moisture, and enhance the root adhering soil/root tissue ratio. These results suggest drought tolerant PGPR from foxtail millet could enhance plant growth under drought stress conditions and serve as effective bioinoculants to sustain agricultural production in arid regions.

  7. Pseudomonas moraviensis subsp. stanleyae, a bacterial endophyte of hyperaccumulator Stanleya pinnata, is capable of efficient selenite reduction to elemental selenium under aerobic conditions.

    Science.gov (United States)

    Staicu, L C; Ackerson, C J; Cornelis, P; Ye, L; Berendsen, R L; Hunter, W J; Noblitt, S D; Henry, C S; Cappa, J J; Montenieri, R L; Wong, A O; Musilova, L; Sura-de Jong, M; van Hullebusch, E D; Lens, P N L; Reynolds, R J B; Pilon-Smits, E A H

    2015-08-01

    To identify bacteria with high selenium tolerance and reduction capacity for bioremediation of wastewater and nanoselenium particle production. A bacterial endophyte was isolated from the selenium hyperaccumulator Stanleya pinnata (Brassicaceae) growing on seleniferous soils in Colorado, USA. Based on fatty acid methyl ester analysis and multi-locus sequence analysis (MLSA) using 16S rRNA, gyrB, rpoB and rpoD genes, the isolate was identified as a subspecies of Pseudomonas moraviensis (97.3% nucleotide identity) and named P. moraviensis stanleyae. The isolate exhibited extreme tolerance to SeO3(2-) (up to 120 mmol l(-1)) and SeO4(2-) (>150 mmol l(-1)). Selenium oxyanion removal from growth medium was measured by microchip capillary electrophoresis (detection limit 95 nmol l(-1) for SeO3(2-) and 13 nmol l(-1) for SeO4(2-)). Within 48 h, P. moraviensis stanleyae aerobically reduced SeO3(2-) to red Se(0) from 10 mmol l(-1) to below the detection limit (removal rate 0.27 mmol h(-1) at 30 °C); anaerobic SeO3(2-) removal was slower. No SeO4(2-) removal was observed. Pseudomonas moraviensis stanleyae stimulated the growth of crop species Brassica juncea by 70% with no significant effect on Se accumulation. Pseudomonas moraviensis stanleyae can tolerate extreme levels of selenate and selenite and can deplete high levels of selenite under aerobic and anaerobic conditions. Pseudomonas moraviensis subsp. stanleyae may be useful for stimulating plant growth and for the treatment of Se-laden wastewater. © 2015 The Society for Applied Microbiology.

  8. An oxidant and organic solvent tolerant alkaline lipase by P. aeruginosa mutant: downstream processing and biochemical characterization

    Directory of Open Access Journals (Sweden)

    Deepali Bisht

    2013-12-01

    Full Text Available An extracellular alkaline lipase from Pseudomonas aeruginosa mutant has been purified to homogeneity using acetone precipitation followed by anion exchange and gel filtration chromatography and resulted in 27-fold purification with 19.6% final recovery. SDS-PAGE study suggested that the purified lipase has an apparent molecular mass of 67 kDa. The optimum temperature and pH for the purified lipase were 45°C and 8.0, respectively. The enzyme showed considerable stability in pH range of 7.0-11.0 and temperature range 35-55 °C. The metal ions Ca2+, Mg2+ and Na+ tend to increase the enzyme activity, whereas, Fe2+ and Mn2+ ions resulted in discreet decrease in the activity. Divalent cations Ca+2 and Mg+2 seemed to protect the enzyme against thermal denaturation at high temperatures and in presence of Ca+2 (5 mM the optimum temperature shifted from 45°C to 55°C. The purified lipase displayed significant stability in the presence of several hydrophilic and hydrophobic organic solvents (25%, v/v up to 168 h. The pure enzyme preparation exhibited significant stability and compatibility with oxidizing agents and commercial detergents as it retained 40-70% of its original activities. The values of Km and Vmax for p-nitrophenyl palmitate (p-NPP under optimal conditions were determined to be 2.0 mg.mL-1 and 5000 μg.mL-1.min-1, respectively.

  9. Pseudomonas putida KT2440 as a host for biochemicals production

    DEFF Research Database (Denmark)

    Calero Valdayo, Patricia

    The extensive use of cell factories for production of biochemicals is still facing a number of challenges to become economically competitive. One of the problems that need to be overcome is the toxicity of certain chemical products, which prevents yields high enough for their implementation...... in industry.This thesis aims at contributing to developing and characterizing tools for the use of alternative hosts organisms with high tolerance towards toxic compounds, such as Pseudomonas putida. The thesis also focuses on identifying target compounds that may be relevant to produce in this strain...... such as p-coumaric acid, and the mechanisms responsible for such natural tolerance. Moreover, the tolerance towards the highly toxic compound p-hydroxystyrene was improved as an alternative strategy to deal with the effect on growth during the production of such compounds. Expanding the toolbox...

  10. Chemotaxis and degradation of organophosphate compound by a novel moderately thermo-halo tolerant Pseudomonas sp. strain BUR11: evidence for possible existence of two pathways for degradation

    Directory of Open Access Journals (Sweden)

    Santanu Pailan

    2015-11-01

    Full Text Available An organophosphate (OP degrading chemotactic bacterial strain BUR11 isolated from an agricultural field was identified as a member of Pseudomonas genus on the basis of its 16S rRNA gene sequence. The strain could utilize parathion, chlorpyrifos and their major hydrolytic intermediates as sole source of carbon for its growth and exhibited positive chemotactic response towards most of them. Optimum concentration of parathion for its growth was recorded to be 200 ppm and 62% of which was degraded within 96 h at 37 °C. Growth studies indicated the strain to be moderately thermo-halo tolerant in nature. Investigation based on identification of intermediates of parathion degradation by thin layer chromatography (TLC, high performance liquid chromatography (HPLC, gas chromatography (GC and liquid chromatography mass spectrometry (LC-MS/MS provided evidence for possible existence of two pathways. The first pathway proceeds via 4-nitrophenol (4-NP while the second proceeds through formation of 4-aminoparathion (4-APar, 4-aminophenol (4-AP and parabenzoquinone (PBQ. This is the first report of chemotaxis towards organophosphate compound by a thermo-halo tolerant bacterium.

  11. Growth of Pseudomonas taiwanensis VLB120∆C biofilms in the presence of n-butanol.

    Science.gov (United States)

    Halan, Babu; Vassilev, Igor; Lang, Karsten; Schmid, Andreas; Buehler, Katja

    2017-07-01

    Biocatalytic processes often encounter problems due to toxic reactants and products, which reduce biocatalyst viability. Thus, robust organisms capable of tolerating or adapting towards such compounds are of high importance. This study systematically investigated the physiological response of Pseudomonas taiwanensis VLB120∆C biofilms when exposed to n-butanol, one of the potential next generation biofuels as well as a toxic substance using microscopic and biochemical methods. Initially P. taiwanensis VLB120∆C biofilms did not show any observable growth in the presence of 3% butanol. Prolonged cultivation of 10 days led to biofilm adaptation, glucose and oxygen uptake doubled and consequently it was possible to quantify biomass. Complementing the medium with yeast extract and presumably reducing the metabolic burden caused by butanol exposure further increased the biomass yield. In course of cultivation cells reduced their size in the presence of n-butanol which results in an enlarged surface-to-volume ratio and thus increased nutrient uptake. Finally, biofilm enhanced its extracellular polymeric substances (EPS) production when exposed to n-butanol. The predominant response of these biofilms under n-butanol stress are higher energy demand, increased biomass yield upon medium complements, larger surface-to-volume ratio and enhanced EPS production. Although we observed a distinct increase in biomass in the presence of 3% butanol it was not possible to cultivate P. taiwanensis VLB120∆C biofilms at higher n-butanol concentrations. Thereby this study shows that biofilms are not per se tolerant against solvents, and need to adapt to toxic n-butanol concentrations. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  12. Study of biochemical characterization and tolerance to nickel and cadmium of 30 bacteria isolated from the microbasin of the Rio Purires (Cartago, Costa Rica)

    International Nuclear Information System (INIS)

    Vargas Asensio, Juan Gabriel

    2009-01-01

    Heavy metal pollution has been a worldwide problem; Costa Rica, a developing country, receives more and more industries, increasing at an accelerated pollution. A study was performed, from water contaminated with heavy metals, in the microbasin of the Rio Purires to isolate and characterize the cultivable bacteria with nickel and cadmium tolerance. The bacterial growth was determined by measuring of changes in the optical density of a medium. A curve of growth and biomass production experiment was made to the bacteria more tolerant to metals. Pseudomonas synxantha proved to be more tolerant to nickel with a minimum inhibitory concentration of 75 ppm and was chosen to make the curve of growth. The bacterium more tolerant to cadmium was Pseudomonas spp with a minimum inhibitory concentration of 22 ppm. A time of 450 minutes was given for the change in logarithmic phase to stationary phase in the curve of number of bacteria versus time, where the yield of biomass production was 1.73% wet weight biomass. The bacterium Pseudomonas synxantha was established as a good alternative to go forward to conduct trials of biosorption and bioremediation. (author) [es

  13. Physical immobilization of 60 kDa chaperonin linked lipase from pseudomonas aeruginosa BN-1

    International Nuclear Information System (INIS)

    Syed, M.N.; Mehmood, S.; Bashir, A.; Ashraf, F.

    2012-01-01

    Abstract: The 60 kDa chaperone linked lipase from Pseudomonas aeruginosa was subjected to physical adsorption on silica 60 and acrylic beads. It was found that higher enzyme loading was achieved on silica gel than acrylic bead. The half life of immobilized enzyme was greater compared to the free enzyme. The adsorption of the enzyme onto a solid phase also resulted in increased thermo and solvent stability. It was observed that soluble enzyme showed maximum stability at 70 degree C while immobilized enzyme showed stability up to 80 degree C for 45 minutes. The stability of immobilized enzyme increased up to 48 hours from 24 hours against different organic solvent at 1.0 M concentration. It was noted that enzyme immobilized on acrylic beads have greater reusability compared to silica immobilized enzyme. (author)

  14. Arsenic-tolerant plant-growth-promoting bacteria isolated from arsenic-polluted soils in South Korea.

    Science.gov (United States)

    Shagol, Charlotte C; Krishnamoorthy, Ramasamy; Kim, Kiyoon; Sundaram, Subbiah; Sa, Tongmin

    2014-01-01

    The Janghang smelter in Chungnam, South Korea started in 1936 was subsequently shutdown in 1989 due to heavy metal (loid) pollution concerns in the vicinity. Thus, there is a need for the soil in the area to be remediated to make it usable again especially for agricultural purposes. The present study was conducted to exploit the potential of arsenic (As)-tolerant bacteria thriving in the vicinity of the smelter-polluted soils to enhance phytoremediation of hazardous As. We studied the genetic and taxonomic diversity of 21 As-tolerant bacteria isolated from soils nearer to and away from the smelter. These isolates belonging to the genera Brevibacterium, Pseudomonas, Microbacterium, Rhodococcus, Rahnella, and Paenibacillus, could tolerate high concentrations of arsenite (As(III)) and arsenate (As(V)) with the minimum inhibitory concentration ranging from 3 to >20 mM for NaAsO2 and 140 to 310 mM NaH2AsO4 · 7H2O, respectively. All isolates exhibited As(V) reduction except Pseudomonas koreensis JS123, which exhibited both oxidation and reduction of As. Moreover, all the 21 isolates produced indole acetic acid (IAA), 13 isolates exhibited 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, 12 produced siderophore, 17 solubilized phosphate, and 13 were putative nitrogen fixers under in vitro conditions. Particularly, Rhodococcus aetherivorans JS2210, P. koreensis JS2214, and Pseudomonas sp. JS238 consistently increased root length of maize in the presence of 100 and 200 μM As(V). Possible utilization of these As-tolerant plant-growth-promoting bacteria can be a potential strategy in increasing the efficiency of phytoremediation in As-polluted soils.

  15. Effects of Pseudomonas species on the release of bound 14C residues from soil treated with [14C]atrazine

    International Nuclear Information System (INIS)

    Khan, S.U.; Behki, R.M.

    1990-01-01

    The release of bound (nonextractable) 14 C residues from soil previously treated with [ 14 C]atrazine was investigated by incubation of the solvent-extracted soil with two species of Pseudomonas capable of metabolizing atrazine. The two species, 192 and 194, released bound 14 C residues from the soil. Addition of glucose, known to increase microbiological activities, to the incubated soil appeared to enhance the release of soil-bound 14 C residues, in particular in the presence of Pseudomonas species 192. The 14 C bound residues in soil, mainly present as the parent compound and its hydroxy and monodealkylated analogues, were released into the incubation mixture and were subsequently metabolized by the two species involving dechlorination and dealkylation

  16. Influence of Solvent-Solvent and Solute-Solvent Interaction Properties on Solvent-Mediated Potential

    International Nuclear Information System (INIS)

    Zhou Shiqi

    2005-01-01

    A recently proposed universal calculational recipe for solvent-mediated potential is applied to calculate excess potential of mean force between two large Lennard-Jones (LJ) or hard core attractive Yukawa particles immersed in small LJ solvent bath at supercritical state. Comparison between the present prediction with a hypernetted chain approximation adopted for solute-solute correlation at infinitely dilute limit and existing simulation data shows high accuracy for the region with large separation, and qualitative reliability for the solute particle contact region. The calculational simplicity of the present recipe allows for a detailed investigation on the effect of the solute-solvent and solvent-solvent interaction details on the excess potential of mean force. The resultant conclusion is that gathering of solvent particles near a solute particle leads to repulsive excess PMF, while depletion of solvent particles away from the solute particle leads to attractive excess PMF, and minor change of the solvent-solvent interaction range has large influence on the excess PMF.

  17. Microbial stress tolerance for biofuels. Systems biology

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zonglin Lewis (ed.) [National Center for Agricultural Utilization Research, USDA-ARS, Peoria, IL (United States)

    2012-07-01

    The development of sustainable and renewable biofuels is attracting growing interest. It is vital to develop robust microbial strains for biocatalysts that are able to function under multiple stress conditions. This Microbiology Monograph provides an overview of methods for studying microbial stress tolerance for biofuels applications using a systems biology approach. Topics covered range from mechanisms to methodology for yeast and bacteria, including the genomics of yeast tolerance and detoxification; genetics and regulation of glycogen and trehalose metabolism; programmed cell death; high gravity fermentations; ethanol tolerance; improving biomass sugar utilization by engineered Saccharomyces; the genomics on tolerance of Zymomonas mobilis; microbial solvent tolerance; control of stress tolerance in bacterial host organisms; metabolomics for ethanologenic yeast; automated proteomics work cell systems for strain improvement; and unification of gene expression data for comparable analyses under stress conditions. (orig.)

  18. Evaluation of the lemongrass plant (Cymbopogon citratus extracted in different solvents for antioxidant and antibacterial activity against human pathogens

    Directory of Open Access Journals (Sweden)

    Balachandar Balakrishnan

    2014-02-01

    Full Text Available Objective: To test antibacterial and antioxidant activity of the lemongrass plant Cymbopogon citratus (C. citratus leaves extracted serially by the solvents (chloroform, methanol and water. Methods: The plant leaves extracts were used for antibacterial activity on Bacillus subtilis, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, Nocardia sp., Serratia sp., and Enterobacter aeruginosa microorganisms by the Kirby Bauer agar disc diffusion method. This study was carried out on lemongrass plant leaf extracts in different concentration of all solvents. The leaf extracts from different solvents were tested for their scavenging activity against the stable free radical DPPH in quantization using a spectrophotometric assay. Oxidative damage was induced in vitro by treating blood DNA and analyzing the effects of the leaf extracts. Results: The results showed that C. citratus extracts exhibited maximum zones of inhibition in chloroform, methanol and water extracts. It was Observed that the C. citratus extracts exhibited maximum zone of inhibition against Bacillus subtilis, Pseudomonas aeruginosa and Proteus vulgaris. Analyzed data in the present work suggested that antibacterial activity of C. citratus plant leaf extracts showed good results for Gram-positive and Gram-negative organisms. DPPH scavenging activity was highly elicited by the extract of C. citratus. Chloroform, methanol and water extracts of C. citratus leaves effectively decreased the extent of DNA damage. Conclusions: The present study suggested that the lemongrass plant extracts could offer various health benefits.

  19. Pseudomonas aeruginosa biofilms in cystic fibrosis

    DEFF Research Database (Denmark)

    Høiby, Niels; Ciofu, Oana; Bjarnsholt, Thomas

    2010-01-01

    The persistence of chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients is due to biofilm-growing mucoid (alginate-producing) strains. A biofilm is a structured consortium of bacteria, embedded in a self-produced polymer matrix consisting of polysaccharide, protein...... and DNA. In CF lungs, the polysaccharide alginate is the major part of the P. aeruginosa biofilm matrix. Bacterial biofilms cause chronic infections because they show increased tolerance to antibiotics and resist phagocytosis, as well as other components of the innate and the adaptive immune system....... As a consequence, a pronounced antibody response develops, leading to immune complex-mediated chronic inflammation, dominated by polymorphonuclear leukocytes. The chronic inflammation is the major cause of the lung tissue damage in CF. Biofilm growth in CF lungs is associated with an increased frequency...

  20. Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07

    Directory of Open Access Journals (Sweden)

    P. Gururaj

    Full Text Available ABSTRACT The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 ºC and pH 7, using a 0.5% (v/v inoculum, 2% (v/v castor oil (inducer, and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 ºC and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.

  1. 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 to be Pseu......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...... of organic carbon per liter, consistently gave significantly higher Pseudomonas CFU counts than Gould's S1 when tested on four Danish soils. NAA 1:100 may, therefore, be a better medium than Gould's S1 for enumeration and isolation of Pseudomonas from the low-nutrient soil environment....

  2. Pseudomonas helleri sp. nov. and Pseudomonas weihenstephanensis sp. nov., isolated from raw cow's milk.

    Science.gov (United States)

    von Neubeck, M; Huptas, C; Glück, C; Krewinkel, M; Stoeckel, M; Stressler, T; Fischer, L; Hinrichs, J; Scherer, S; Wenning, M

    2016-03-01

    Analysis of the microbiota of raw cow's milk and semi-finished milk products yielded seven isolates assigned to the genus Pseudomonas that formed two individual groups in a phylogenetic analysis based on partial rpoD and 16S rRNA gene sequences. The two groups could be differentiated from each other and also from their closest relatives as well as from the type species Pseudomonas aeruginosa by phenotypic and chemotaxonomic characterization and average nucleotide identity (ANIb) values calculated from draft genome assemblies. ANIb values within the groups were higher than 97.3 %, whereas similarity values to the closest relatives were 85 % or less. The major cellular lipids of strains WS4917T and WS4993T were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol; the major quinone was Q-9 in both strains, with small amounts of Q-8 in strain WS4917T. The DNA G+C contents of strains WS4917T and WS4993T were 58.08 and 57.30 mol%, respectively. Based on these data, strains WS4917T, WS4995 ( = DSM 29141 = LMG 28434), WS4999, WS5001 and WS5002 should be considered as representatives of a novel species of the genus Pseudomonas, for which the name Pseudomonas helleri sp. nov. is proposed. The type strain of Pseudomonas helleri is strain WS4917T ( = DSM 29165T = LMG 28433T). Strains WS4993T and WS4994 ( = DSM 29140 = LMG 28438) should be recognized as representing a second novel species of the genus Pseudomonas, for which the name Pseudomonas weihenstephanensis sp. nov. is proposed. The type strain of Pseudomonas weihenstephanensis is strain WS4993T ( = DSM 29166T = LMG 28437T).

  3. Biodegradation of 2,4'-dichlorobiphenyl, a congener of polychlorinated biphenyl, by Pseudomonas isolates GSa and GSb.

    Science.gov (United States)

    Gayathri, D; Shobha, K J

    2015-08-01

    Bioegradation of 2,4'-dichlorobiphenyl (2,4 CB), by two isolates of Pseudomonas (GSa and GSb) was compared using GC-MS. Transformer oil polluted soil was used for the isolation of 2,4 CB degrading bacteria. GC-MS analysis of the solvent extracts obtained from Pseudomonas sp. GSa spent culture indicated the presence of Phenol 2,6-bis (1,1-dimethyl)-4-methyl (C15H24O). Further, the enzyme analysis of the cell free extracts showed the presence of 2,4'-dichlorobiphenyl dehalogenase (CBD), 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR) with specific activity of 6.00, 0.4 and 0.22 pmol/min/mg of protein, suggesting that dechlorination as an important step during 2,4 CB catabolism. Further, the cell free extract of GSb showed only 2,4'-dichlorobiphenyl-NADPH-oxido-reductase (2,4 CBOR) and 2,3-dihydroxybiphenyl-NADPH-oxido-reductase (2,3 DHOR), with specific activity of 0.3 and 0.213 μmol/min/mg of protein, suggesting attack on non-chlorinated aromatic ring of 2,4 CB, releasing chlorinated intermediates which are toxic to the environment. Although, both the isolated bacteria (GSa and GSb) belong to Pseudomonas spp., they exhibited different metabolic potential.

  4. A Mig-14-like protein (PA5003) affects antimicrobial peptide recognition in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Jochumsen, Nicholas; Liu, Yang; Molin, Søren

    2011-01-01

    The evolution of antibiotic resistance in pathogenic bacteria is a growing global health problem which is gradually making the treatment of infectious diseases less efficient. Antimicrobial peptides are small charged molecules found in organisms from the complete phylogenetic spectrum. The peptides...... are attractive candidates for novel drug development due to their activity against bacteria that are resistant to conventional antibiotics, and reports of peptide resistance are rare in the clinical setting. Paradoxically, many clinically relevant bacteria have mechanisms that can recognize and respond...... to the presence of cationic antimicrobial peptides (CAMPs) in the environment by changing the properties of the microbial surface thereby increasing the tolerance of the microbes towards the peptides. In Pseudomonas aeruginosa an essential component of this inducible tolerance mechanism is the lipopolysaccharide...

  5. Pseudomonas lactis sp. nov. and Pseudomonas paralactis sp. nov., isolated from bovine raw milk.

    Science.gov (United States)

    von Neubeck, Mario; Huptas, Christopher; Glück, Claudia; Krewinkel, Manuel; Stoeckel, Marina; Stressler, Timo; Fischer, Lutz; Hinrichs, Jörg; Scherer, Siegfried; Wenning, Mareike

    2017-06-01

    Five strains, designated WS 4672T, WS 4998, WS 4992T, WS 4997 and WS 5000, isolated from bovine raw milk formed two individual groups in a phylogenetic analysis. The most similar species on the basis of 16S rRNA gene sequences were Pseudomonas azotoformans IAM 1603T, Pseudomonas gessardii CIP 105469T and Pseudomonas libanensis CIP 105460T showing 99.7-99.6 % similarity. Using rpoD gene sequences Pseudomonas veronii LMG 17761T (93.3 %) was most closely related to strain WS 4672T and Pseudomonas libanensis CIP 105460T to strain WS 4992T (93.3 %). The five strains could be differentiated from their closest relatives and from each other by phenotypic and chemotaxonomic characterization and ANIb values calculated from draft genome assemblies. ANIb values of strains WS 4992T and WS4671T to the closest relatives are lower than 90 %. The major cellular polar lipids of both strains are phosphatidylethanolamine, phosphatidylglycerol, a phospholipid and diphosphatidylglycerol, and their major quinone is Q-9. The DNA G+C content of strains WS 4992T and WS 4672T were 60.0  and 59.7  mol%, respectively. Based on these genotypic and phenotypic traits two novel species of the genus Pseudomonas are proposed: Pseudomonas lactis sp. nov. [with type strain WS 4992T (=DSM 29167T=LMG 28435T) and the additional strains WS 4997 and WS 5000], and Pseudomonasparalactis sp. nov. [with type strain WS 4672T (=DSM 29164T=LMG 28439T) and additional strain WS 4998].

  6. Transesterification of waste cooking oil by an organic solvent-tolerant alkaline lipase from Streptomyces sp. CS273.

    Science.gov (United States)

    Mander, Poonam; Yoo, Hah-Young; Kim, Seung Wook; Choi, Yun Hee; Cho, Seung Sik; Yoo, Jin Cheol

    2014-02-01

    The aim of this present study was to produce a microbial enzyme that can potentially be utilized for the enzymatic transesterification of waste cooking oil. To that end, an extracellular lipase was isolated and purified from the culture broth of Streptomyces sp. CS273. The molecular mass of purified lipase was estimated to be 36.55 kDa by SDS PAGE. The optimum lipolytic activity was obtained at alkaline pH 8.0 to 8.5 and temperature 40 °C, while the enzyme was stable in the pH range 7.0 ∼ 9.0 and at temperature ≤40 °C. The lipase showed highest hydrolytic activity towards p-nitrophenyl myristate (C14). The lipase activity was enhanced by several salts and detergents including NaCl, MnSo₄, and deoxy cholic acid, while phenylmethylsulfonyl fluoride at concentration 10 mM inhibited the activity. The lipase showed tolerance towards different organic solvents including ethanol and methanol which are commonly used in transesterification reactions to displace alcohol from triglycerides (ester) contained in renewable resources to yield fatty acid alkyl esters known as biodiesel. Applicability of the lipase in transesterification of waste cooking oil was confirmed by gas chromatography mass spectrometry analysis.

  7. Removal of Nitrate in Simulated Water at Low Temperature by a Novel Psychrotrophic and Aerobic Bacterium, Pseudomonas taiwanensis Strain J

    Directory of Open Access Journals (Sweden)

    Tengxia He

    2018-01-01

    Full Text Available Low temperatures and high pH generally inhibit the biodenitrification. Thus, it is important to explore the psychrotrophic and alkali-resisting microorganism for degradation of nitrogen. This research was mainly focused on the identification of a psychrotrophic strain and preliminary explored its denitrification characteristics. The new strain J was isolated using the bromothymol blue solid medium and identified as Pseudomonas taiwanensis on the basis of morphology and phospholipid fatty acid as well as 16S rRNA gene sequence analyses, which is further testified to work efficiently for removing nitrate from wastewater at low temperature circumstances. This is the first report that Pseudomonas taiwanensis possessed excellent tolerance to low temperature, with 15°C as its optimum and 5°C as viable. The Pseudomonas taiwanensis showed unusual ability of aerobic denitrification with the nitrate removal efficiencies of 100% at 15°C and 51.61% at 5°C. Single factor experiments showed that the optimal conditions for denitrification were glucose as carbon source, 15°C, shaking speed 150 r/min, C/N 15, pH≥7, and incubation quantity 2.0 × 106 CFU/mL. The nitrate and total nitrogen removal efficiencies were up to 100% and 93.79% at 15°C when glucose is served as carbon source. These results suggested that strain J had aerobic denitrification ability, as well as the notable ability to tolerate the low temperature and high pH.

  8. Removal of Nitrate in Simulated Water at Low Temperature by a Novel Psychrotrophic and Aerobic Bacterium, Pseudomonas taiwanensis Strain J

    Science.gov (United States)

    He, Tengxia; Ye, Qing; Sun, Quan; Cai, Xi; Ni, Jiupai

    2018-01-01

    Low temperatures and high pH generally inhibit the biodenitrification. Thus, it is important to explore the psychrotrophic and alkali-resisting microorganism for degradation of nitrogen. This research was mainly focused on the identification of a psychrotrophic strain and preliminary explored its denitrification characteristics. The new strain J was isolated using the bromothymol blue solid medium and identified as Pseudomonas taiwanensis on the basis of morphology and phospholipid fatty acid as well as 16S rRNA gene sequence analyses, which is further testified to work efficiently for removing nitrate from wastewater at low temperature circumstances. This is the first report that Pseudomonas taiwanensis possessed excellent tolerance to low temperature, with 15°C as its optimum and 5°C as viable. The Pseudomonas taiwanensis showed unusual ability of aerobic denitrification with the nitrate removal efficiencies of 100% at 15°C and 51.61% at 5°C. Single factor experiments showed that the optimal conditions for denitrification were glucose as carbon source, 15°C, shaking speed 150 r/min, C/N 15, pH ≥ 7, and incubation quantity 2.0 × 106 CFU/mL. The nitrate and total nitrogen removal efficiencies were up to 100% and 93.79% at 15°C when glucose is served as carbon source. These results suggested that strain J had aerobic denitrification ability, as well as the notable ability to tolerate the low temperature and high pH. PMID:29789796

  9. Pseudomonas fluorescens-like bacteria from the stomach: a microbiological and molecular study.

    Science.gov (United States)

    Patel, Saurabh Kumar; Pratap, Chandra Bhan; Verma, Ajay Kumar; Jain, Ashok Kumar; Dixit, Vinod Kumar; Nath, Gopal

    2013-02-21

    To characterize oxidase- and urease-producing bacterial isolates, grown aerobically, that originated from antral biopsies of patients suffering from acid peptic diseases. A total of 258 antral biopsy specimens were subjected to isolation of bacteria followed by tests for oxidase and urease production, acid tolerance and aerobic growth. The selected isolates were further characterized by molecular techniques viz. amplifications for 16S rRNA using universal eubacterial and HSP60 gene specific primers. The amplicons were subjected to restriction analysis and partial sequencing. A phylogenetic tree was generated using unweighted pair group method with arithmetic mean (UPGMA) from evolutionary distance computed with bootstrap test of phylogeny. Assessment of acidity tolerance of bacteria isolated from antrum was performed using hydrochloric acid from 10(-7) mol/L to 10(-1) mol/L. Of the 258 antral biopsy specimens collected from patients, 179 (69.4%) were positive for urease production by rapid urease test and 31% (80/258) yielded typical Helicobacter pylori (H. pylori) after 5-7 d of incubation under a microaerophilic environment. A total of 240 (93%) antral biopsies yielded homogeneous semi-translucent and small colonies after overnight incubation. The partial 16S rRNA sequences revealed that the isolates had 99% similarity with Pseudomonas species. A phylogenetic tree on the basis of 16S rRNA sequences denoted that JQ927226 and JQ927227 were likely to be related to Pseudomonas fluorescens (P. fluorescens). On the basis of HSP60 sequences applied to the UPGMA phylogenetic tree, it was observed that isolated strains in an aerobic environment were likely to be P. fluorescens, and HSP60 sequences had more discriminatory potential rather than 16S rRNA sequences. Interestingly, this bacterium was acid tolerant for hours at low pH. Further, a total of 250 (96.9%) genomic DNA samples of 258 biopsy specimens and DNA from 240 bacterial isolates were positive for the 613 bp

  10. Overexpression of Nictaba-Like Lectin Genes from Glycine max Confers Tolerance towards Pseudomonas syringae Infection, Aphid Infestation and Salt Stress in Transgenic Arabidopsis Plants

    Directory of Open Access Journals (Sweden)

    Sofie Van Holle

    2016-10-01

    Full Text Available Plants have evolved a sophisticated immune system that allows them to recognize invading pathogens by specialized receptors. Carbohydrate-binding proteins or lectins are part of this immune system and especially the lectins that reside in the nucleocytoplasmic compartment are known to be implicated in biotic and abiotic stress responses. The class of Nictaba-like lectins (NLL groups all proteins with homology to the tobacco (Nicotiana tabacum lectin, known as a stress-inducible lectin. Here we focus on two Nictaba homologs from soybean (Glycine max, referred to as GmNLL1 and GmNLL2. Confocal laser scanning microscopy of fusion constructs with the green fluorescent protein either transiently expressed in Nicotiana benthamiana leaves or stably transformed in tobacco BY-2 suspension cells revealed a nucleocytoplasmic localization for the GmNLLs under study. RT-qPCR analysis of the transcript levels for the Nictaba-like lectins in soybean demonstrated that the genes are expressed in several tissues throughout the development of the plant. Furthermore, it was shown that salt treatment, Phytophthora sojae infection and Aphis glycines infestation trigger the expression of particular NLL genes. Stress experiments with Arabidopsis lines overexpressing the NLLs from soybean yielded an enhanced tolerance of the plant towards bacterial infection (Pseudomonas syringae, insect infestation (Myzus persicae and salinity. Our data showed a better performance of the transgenic lines compared to wild type plants, indicating that the NLLs from soybean are implicated in the stress response. These data can help to further elucidate the physiological importance of the Nictaba-like lectins from soybean, which can ultimately lead to the design of crop plants with a better tolerance to changing environmental conditions.

  11. Pseudomonas wadenswilerensis sp. nov. and Pseudomonas reidholzensis sp. nov., two novel species within the Pseudomonas putida group isolated from forest soil.

    Science.gov (United States)

    Frasson, David; Opoku, Michael; Picozzi, Tara; Torossi, Tanja; Balada, Stefanie; Smits, Theo H M; Hilber, Urs

    2017-08-01

    Within the frame of a biotechnological screening, we isolated two Pseudomonas strains from forest soil. 16S rRNA gene sequence analysis indicated that strain CCOS 864T shared 99.8 % similarity with Pseudomonas donghuensis HYST, while strain CCOS 865T shared 99.0 % similarity with Pseudomonas putida DSM 291T and lower similarity with other P. putida group type strains. Based on multilocus sequence analysis, the two strains were genotypically distinct from each other, each forming a separate clade. Strains CCOS 864T and CCOS 865T were Gram-stain-negative, motile and rod-shaped, growing at a temperature range of 4-37 °C. Strain CCOS 864T could be phenotypically distinguished from P. putida group species by the combination of gelatinase-positive reaction and positive growth on N-acetyl-d-glucosamine, p-hydroxyphenylacetic acid and inosine but lack of fluorescein production on King's B medium, while strain CCOS 865T could be distinguished from P. putida group species by the combination of positive growth with saccharic acid and negative growth with p-hydroxyphenylacetic acid and l-pyroglutamic acid. The major polar lipid for both strains was phosphatidylethanolamine; the major quinone was ubiquinone Q-9. DNA-DNA hybridization and average nucleotide identities confirmed the novel species status for the two strains. The DNA G+C contents of CCOS 864T and CCOS 865T were 62.1 and 63.8 mol%, respectively. The phenotypic, phylogenetic and DNA-DNA relatedness data support the suggestion that CCOS 864T and CCOS 865T represent two novel Pseudomonas species. The names Pseudomonas wadenswilerensis sp. nov. (type strain CCOS 864T=LMG 29327T) and Pseudomonas reidholzensis sp. nov. (type strain CCOS 865T=LMG 29328T) are proposed.

  12. 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.

  13. Alginate Adsorbent Immobilization Technique Promotes Biobutanol Production by Clostridium acetobutylicum Under Extreme Condition of High Concentration of Organic Solvent

    Directory of Open Access Journals (Sweden)

    Zhuoliang Ye

    2018-05-01

    Full Text Available In Acetone-Butanol-Ethanol fermentation, bacteria should tolerate high concentrations of solvent products, which inhibit bacteria growth and limit further increase of solvents to more than 20 g/L. Moreover, this limited solvent concentration significantly increases the cost of solvent separation through traditional approaches. In this study, alginate adsorbent immobilization technique was successfully developed to assist in situ extraction using octanol which is effective in extracting butanol but presents strong toxic effect to bacteria. The adsorbent improved solvent tolerance of Clostridium acetobutylicum under extreme condition of high concentration of organic solvent. Using the developed technique, more than 42% of added bacteria can be adsorbed to the adsorbent. Surface area of the adsorbent was more than 10 times greater than sodium alginate. Scanning electron microscope image shows that an abundant amount of pore structure was successfully developed on adsorbents, promoting bacteria adsorption. In adsorbent assisted ABE fermentation, there was 21.64 g/L butanol in extracting layer compared to negligible butanol produced with only the extractant but without the adsorbent, for the reason that adsorbent can reduce damaging exposure of C. acetobutylicum to octanol. The strategy can improve total butanol production with respect to traditional culture approach by more than 2.5 fold and save energy for subsequent butanol recovery, which effects can potentially make the biobutanol production more economically practical.

  14. Pseudomonas Lipopeptide Biosurfactants

    DEFF Research Database (Denmark)

    Bonnichsen, Lise

    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...... lipopetide biosurfactants in pollutant biodegradation and natural roles in biofilm formation. The work presented is a combination of environmental microbiology and exploiting genetic manipulation of pure cultures to achieve insightinto the effects and mechanisms of lipopeptides on microbial processes...

  15. Biotoxic impact of heavy metals on growth, oxidative stress and morphological changes in root structure of wheat (Triticum aestivum L.) and stress alleviation by Pseudomonas aeruginosa strain CPSB1.

    Science.gov (United States)

    Rizvi, Asfa; Khan, Mohd Saghir

    2017-10-01

    Rapid industrialization and uncontrolled metal discharge into environment is a global concern for crop production. Metal tolerant bacterium isolated from chilli rhizosphere was identified as Pseudomonas aeruginosa by 16S rDNA sequence analysis. Pseudomonas aeruginosa tolerated high concentrations of Cu (1400 μg ml -1 ), Cd (1000 μg ml -1 ) and Cr (1000 μg ml -1 ). Pseudomonas aeruginosa CPSB1 produced multiple plant growth promoting biomolecules in the presence and absence of metals. Strain CPSB1 solubilized P at 400 μg ml -1 of Cd, Cr and Cu. The strain was positive for indole-3-acetic acid (IAA), siderophores, hydrogen cyanide (HCN), ammonia (NH 3 ) and 1-aminocyclopropane-1-carboxylate (ACC) deaminase when grown with/without metals. The phytotoxic effects on wheat increased with increasing Cd, Cr and Cu rates. The P. aeruginosa CPSB1 inoculated wheat in contrast had better growth and yields under Cu, Cd and Cr stress. The root dry biomass of inoculated plants was enhanced by 44, 28 and 48% at 2007 mg Cu kg -1 , 36 mg Cd kg -1 and 204 mg Cr kg -1 , respectively. The bioinoculant enhanced number of spikes, grain and straw yields by 25, 17 and 12%, respectively. Pseudomonas aeruginosa CPSB1 significantly declined the levels of catalase (CAT), glutathione reductase (GR) and superoxide dismutase SOD), proline and malondialdehyde (MDA), and reduced metal uptake by wheat. The study demonstrated that P. aeruginosa CPSB1 possessed plant growth promoting potentials, showed metal tolerance capability and had ability to counteract deleterious metal impacts. Due to these, P. aeruginosa CPSB1 could be used as bioinoculant for enhancing wheat production even in metal contaminated soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Hyperbaric oxygen sensitizes anoxic Pseudomonas aeruginosa biofilm to ciprofloxacin

    DEFF Research Database (Denmark)

    Kolpen, Mette; Lerche, Christian J; Kragh, Kasper Nørskov

    2017-01-01

    Chronic Pseudomonas aeruginosa lung infection is characterized by the presence of endobronchial antibiotic-tolerant biofilm subject to strong oxygen (O2) depletion due to the activity of surrounding polymorphonuclear leukocytes. The exact mechanisms affecting the antibiotic susceptibility...... metabolism activity and the endogenous formation of reactive O2 radicals (ROS). In this study we aimed to apply hyperbaric oxygen treatment (HBOT) in order to sensitize anoxic P. aeruginosa agarose-biofilms established to mimic situations with intense O2 consumption by the host response in the cystic...... fibrosis (CF) lung. Application of HBOT resulted in enhanced bactericidal activity of ciprofloxacin at clinically relevant durations and was accompanied by indications of restored aerobic respiration, involvement of endogenous lethal oxidative stress and increased bacterial growth. The findings highlight...

  17. Extracellular DNA Shields against Aminoglycosides in Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Nilsson, Martin; Jensen, Peter Østrup

    2013-01-01

    Within recent years, it has been established that extracellular DNA is a key constituent of the matrix of microbial biofilms. In addition, it has recently been demonstrated that DNA binds positively charged antimicrobials such as aminoglycosides and antimicrobial peptides. In the present study, we...... provide evidence that extracellular DNA shields against aminoglycosides in Pseudomonas aeruginosa biofilms. We show that exogenously supplemented DNA integrates into P. aeruginosa biofilms and increases their tolerance toward aminoglycosides. We provide evidence that biofilms formed by a DNA release......-deficient P. aeruginosa quorum-sensing mutant are more susceptible to aminoglycoside treatment than wild-type biofilms but become rescued from the detrimental action of aminoglycosides upon supplementation with exogenous DNA. Furthermore, we demonstrate that exposure to lysed polymorphonuclear leukocytes...

  18. Accumulation of a Polyhydroxyalkanoate Containing Primarily 3-Hydroxydecanoate from Simple Carbohydrate Substrates by Pseudomonas sp. Strain NCIMB 40135.

    Science.gov (United States)

    Haywood, G W; Anderson, A J; Ewing, D F; Dawes, E A

    1990-11-01

    A number of Pseudomonas species have been identified which accumulate a polyhydroxyalkanoate containing mainly 3-hydroxydecanoate monomers from sodium gluconate as the sole carbon source. One of these, Pseudomonas sp. strain NCIMB 40135, was further investigated and shown to accumulate such a polyhydroxyalkanoate from a wide range of carbon sources (C(2) to C(6)); however, when supplied with octanoic acid it produced a polyhydroxyalkanoate containing mainly 3-hydroxyoctanoate monomers. Polymer synthesis occurred in batch culture after cessation of growth due to exhaustion of nitrogen. In continuous culture under nitrogen limitation up to 16.9% (wt/wt) polyhydroxyalkanoate was synthesized from glucose as the carbon source. The monomer units are mainly of the R-(-) configuration. Nuclear magnetic resonance studies confirmed the composition of the polymer. Differential scanning calorimetry suggested that the solvent-extracted polymer contained a significant proportion of crystalline material. The weight-average molecular weight of the polymer from glucose-grown cells was 143,000.

  19. A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: characterization and application to enzymatic biodiesel production.

    Science.gov (United States)

    Adachi, Daisuke; Koh, FookHee; Hama, Shinji; Ogino, Chiaki; Kondo, Akihiko

    2013-05-10

    To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40-50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C. In addition, r-BTL was highly tolerant to 30% (v/v) organic solvents (dimethyl carbonate, ethanol, methanol, 2-propanol or acetone). The attractive characteristics of r-BTL also worked efficiently on palm oil methanolysis, resulting in a nearly 100% conversion at elevated temperature from 40 to 50°C. Moreover, r-BTL catalyzed methanolysis at a high methanol concentration without a significant loss of lipase activity. In particular, when 2 molar equivalents of methanol were added 2 times, a methyl ester content of more than 90% was achieved; the yield was higher than those of conventional whole-cell biocatalyst and commercial Candida antarctica lipase (Novozym 435). On the basis of the results regarding the excellent lipase characteristics and efficient biodiesel production, the developed whole-cell biocatalyst would be a promising biocatalyst in a broad range of applications including biodiesel production. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. "Hot Tub Rash" and "Swimmer's Ear" (Pseudomonas)

    Science.gov (United States)

    Facts About “Hot Tub Rash” and “Swimmer’s Ear” (Pseudomonas) What is Pseudomonas and how can it affect me? Pseudomonas (sue-doh- ... a major cause of infections commonly known as “hot tub rash” and “swimmer’s ear.” This germ is ...

  1. Antimicrobial potential and phyto chemical analysis of different solvent extracted samples of viola pilosa

    International Nuclear Information System (INIS)

    Bakht, J.; Panni, M. K.; Shafi, M.

    2017-01-01

    Investigation of susceptibility of medicinal plants for bacterial pathogens is significant for suitable choice of treatment. Different solvent extracted samples of Viola pilosa shoots were investigated for their antibacterial and phytochemical activities using 0.5, 1 and 2 mg disc-1 concentrations. The antibacterial bioassay was assayed by disc diffusion method against six microbes. The studies revealed that ethyl acetate extracted fractions resulted in maximum growth inhibition of Pseudomonas aeruginosa and Staphylococcus aureus at 2000 mu g disc-1 concentration. Similarly, Xanthomonas campestris and Klebsiella pneumonia were found more susceptible to n-butanol extract. Maximum reduction in the activity of B. subtilis and E. coli was recorded by n-hexane fractions at two mg per disc. The most susceptible microbe was Pseudomonas aeruginosa. The results further revealed that all the tested microbes were found completely resistant to water extracted fractions at all the tested concentrations measuring 0% ZI. Phytochemical analysis showed the presence of various bioactive compounds including flavonoids, glycosides, proteins, fats, alkaloids, steroids, saponins, carbohydrates and tannins. (author)

  2. Triazole-containing N-acyl homoserine lactones targeting the quorum sensing system in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Hansen, Mette Reimert; Jakobsen, Tim H.; Bang, Claus Gunnar

    2015-01-01

    the pathogenesis and antibiotic tolerance of a bacterial biofilm. To identify the structural elements important for antagonistic or agonistic activity against the Pseudomonas aeruginosa LasR protein, we report the synthesis and screening of new triazole-containing mimics of natural N-acyl homoserine lactones....... A series of azide- and alkyne-containing homoserine lactone building blocks was used to prepare an expanded set of 123 homoserine lactone analogues through a combination of solution- and solid-phase synthesis methods. The resulting compounds were subjected to cell-based quorum sensing screening assays...

  3. 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...

  4. CXCR1 regulates pulmonary anti-Pseudomonas host defense

    Science.gov (United States)

    Carevic, M.; Öz, H.; Fuchs, K.; Laval, J.; Schroth, C.; Frey, N.; Hector, A.; Bilich, T.; Haug, M.; Schmidt, A.; Autenrieth, S. E.; Bucher, K.; Beer-Hammer, S.; Gaggar, A.; Kneilling, M.; Benarafa, C.; Gao, J.; Murphy, P.; Schwarz, S.; Moepps, B.; Hartl, D.

    2016-01-01

    Pseudomonas aeruginosa is a key opportunistic pathogen causing disease in cystic fibrosis (CF) and other lung diseases such as chronic obstructive pulmonary disease (COPD). However, the pulmonary host defense mechanisms regulating anti-Pseudomonas aeruginosa immunity remain incompletely understood. Here we demonstrate, by studying an airway Pseudomonas aeruginosa infection model, in vivo bioluminescence imaging, neutrophil effector responses and human airway samples, that the chemokine receptor CXCR1 regulates pulmonary host defense against Pseudomonas aeruginosa. Mechanistically, CXCR1 regulated anti-Pseudomonas neutrophil responses through modulation of reactive oxygen species and interference with toll-like receptor 5 expression. These studies define CXCR1 as a novel non-canonical chemokine receptor that regulates pulmonary anti-Pseudomonas host defense with broad implications for CF, COPD and other infectious lung diseases. PMID:26950764

  5. Pseudomonas predators: understanding and exploiting phage-host interactions.

    Science.gov (United States)

    De Smet, Jeroen; Hendrix, Hanne; Blasdel, Bob G; Danis-Wlodarczyk, Katarzyna; Lavigne, Rob

    2017-09-01

    Species in the genus Pseudomonas thrive in a diverse set of ecological niches and include crucial pathogens, such as the human pathogen Pseudomonas aeruginosa and the plant pathogen Pseudomonas syringae. The bacteriophages that infect Pseudomonas spp. mirror the widespread and diverse nature of their hosts. Therefore, Pseudomonas spp. and their phages are an ideal system to study the molecular mechanisms that govern virus-host interactions. Furthermore, phages are principal catalysts of host evolution and diversity, which directly affects the ecological roles of environmental and pathogenic Pseudomonas spp. Understanding these interactions not only provides novel insights into phage biology but also advances the development of phage therapy, phage-derived antimicrobial strategies and innovative biotechnological tools that may be derived from phage-bacteria interactions.

  6. Garlic blocks quorum sensing and promotes rapid clearing of pulmonary Pseudomonas aeruginosa infections

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Jensen, P. Ø.; Rasmussen, Thomas Bovbjerg

    2005-01-01

    The opportunistic human pathogen Pseudomonas aeruginosa is the predominant micro-organism of chronic lung infections in cystic fibrosis patients. P. aeruginosa colonizes the lungs by forming biofilm microcolonies throughout the lung. Quorum sensing (QS) renders the biofilm bacteria highly tolerant......-treated biofilm. Garlic extract was administered as treatment for a mouse pulmonary infection model. Mice were treated with garlic extract or placebo for 7 days, with the initial 2 days being prophylactic before P. aeruginosa was instilled in the left lung of the mice. Bacteriology, mortality, histopathology...... and phagocytosis by PMNs, as well as leading to an improved outcome of pulmonary infections....

  7. 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...

  8. Quick change: post-transcriptional regulation in Pseudomonas.

    Science.gov (United States)

    Grenga, Lucia; Little, Richard H; Malone, Jacob G

    2017-08-01

    Pseudomonas species have evolved dynamic and intricate regulatory networks to fine-tune gene expression, with complex regulation occurring at every stage in the processing of genetic information. This approach enables Pseudomonas to generate precise individual responses to the environment in order to improve their fitness and resource economy. The weak correlations we observe between RNA and protein abundance highlight the significant regulatory contribution of a series of intersecting post-transcriptional pathways, influencing mRNA stability, translational activity and ribosome function, to Pseudomonas environmental responses. This review examines our current understanding of three major post-transcriptional regulatory systems in Pseudomonas spp.; Gac/Rsm, Hfq and RimK, and presents an overview of new research frontiers, emerging genome-wide methodologies, and their potential for the study of global regulatory responses in Pseudomonas. © FEMS 2017.

  9. Biodegradation of indole at high concentration by persolvent fermentation with Pseudomonas sp. ST-200.

    Science.gov (United States)

    Doukyu, N; Aono, R

    1997-05-01

    Pseudomonas sp. strain ST-200 grew on indole as a sole carbon source. The minimal inhibitory concentration of indole was 0.3 mg/ml for ST-200. However, ST-200 grew in a persolvent fermentation system containing a large amount of indole (a medium containing 20% by vol. diphenylmethane and 4 mg/ml indole), because most of the indole was partitioned in the organic solvent layer. When the organism was grown in the medium containing indole at 1 mg/ml in the presence of diphenylmethane, more than 98% of the indole was consumed after 48h. Isatic acid (0.4 mg/ml) and isatin (0.03 mg/ml) were produced as the metabolites in the aqueous medium layer.

  10. Solvent selection methodology for pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; Kumar Tula, Anjan; Gani, Rafiqul

    2016-01-01

    A method for the selection of appropriate solvents for the solvent swap task in pharmaceutical processes has been developed. This solvent swap method is based on the solvent selection method of Gani et al. (2006) and considers additional selection criteria such as boiling point difference...... in pharmaceutical processes as well as new solvent swap alternatives. The method takes into account process considerations such as batch distillation and crystallization to achieve the swap task. Rigorous model based simulations of the swap operation are performed to evaluate and compare the performance...

  11. Small Rna Regulatory Networks In Pseudomonas Putida

    DEFF Research Database (Denmark)

    Bojanovic, Klara; Long, Katherine

    2015-01-01

    chemicals and has a potential to be used as an efficient cell factory for various products. P. putida KT2240 is a genome-sequenced strain and a well characterized pseudomonad. Our major aim is to identify small RNA molecules (sRNAs) and their regulatory networks. A previous study has identified 37 sRNAs...... in this strain, while in other pseudomonads many more sRNAs have been found so far.P. putida KT2440 has been grown in different conditions which are likely to be encountered in industrial fermentations with the aim of using sRNAs for generation of improved cell factories. For that, cells have been grown in LB......Pseudomonas putida is a ubiquitous Gram-negative soil bacterium with a versatile metabolism and ability to degrade various toxic compounds. It has a high tolerance to different future biobased building blocks and various other stringent conditions. It is used in industry to produce some important...

  12. Enhanced annotations and features for comparing thousands of Pseudomonas genomes in the Pseudomonas genome database.

    Science.gov (United States)

    Winsor, Geoffrey L; Griffiths, Emma J; Lo, Raymond; Dhillon, Bhavjinder K; Shay, Julie A; Brinkman, Fiona S L

    2016-01-04

    The Pseudomonas Genome Database (http://www.pseudomonas.com) is well known for the application of community-based annotation approaches for producing a high-quality Pseudomonas aeruginosa PAO1 genome annotation, and facilitating whole-genome comparative analyses with other Pseudomonas strains. To aid analysis of potentially thousands of complete and draft genome assemblies, this database and analysis platform was upgraded to integrate curated genome annotations and isolate metadata with enhanced tools for larger scale comparative analysis and visualization. Manually curated gene annotations are supplemented with improved computational analyses that help identify putative drug targets and vaccine candidates or assist with evolutionary studies by identifying orthologs, pathogen-associated genes and genomic islands. The database schema has been updated to integrate isolate metadata that will facilitate more powerful analysis of genomes across datasets in the future. We continue to place an emphasis on providing high-quality updates to gene annotations through regular review of the scientific literature and using community-based approaches including a major new Pseudomonas community initiative for the assignment of high-quality gene ontology terms to genes. As we further expand from thousands of genomes, we plan to provide enhancements that will aid data visualization and analysis arising from whole-genome comparative studies including more pan-genome and population-based approaches. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. SOLVENT HOLD TANK SAMPLE RESULTS FOR MCU-13-189, MCU-13-190, AND MCU-13-191: QUARTERLY SAMPLE FROM SEPTEMBER 2013

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Taylor-Pashow, K.

    2013-10-31

    Savannah River National Laboratory (SRNL) analyzed solvent samples from Modular Caustic-Side Solvent Extraction Unit (MCU) in support of continuing operations. A quarterly analysis of the solvent is required to maintain solvent composition within specifications. Analytical results of the analyses of Solvent Hold Tank (SHT) samples MCU-13-189, MCU-13-190, and MCU-13-191 received on September 4, 2013 are reported. The results show that the solvent (remaining heel in the SHT tank) at MCU contains excess Isopar L and a deficit concentration of modifier and trioctylamine when compared to the standard MCU solvent. As with the previous solvent sample results, these analyses indicate that the solvent does not require Isopar L trimming at this time. Since MCU is switching to NGS, there is no need to add TOA nor modifier. SRNL also analyzed the SHT sample for {{sup 137}Cs content and determined the measured value is within tolerance and the value has returned to levels observed in 2011.

  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... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3415 Pseudomonas spp. serological reagents. (a) Identification. Pseudomonas spp. serological reagents are devices that...

  15. Characterization of a Highly Thermostable and Organic Solvent-Tolerant Copper-Containing Polyphenol Oxidase with Dye-Decolorizing Ability from Kurthia huakuii LAM0618T.

    Directory of Open Access Journals (Sweden)

    Xiang Guo

    Full Text Available Laccases are green biocatalysts that possess attractive advantages for the treatment of resistant environmental pollutants and dye effluents. A putative laccase-like gene, laclK, encoding a protein of 29.3 kDa and belonging to the Cu-oxidase_4 superfamily, was cloned and overexpressed in Escherichia coli. The purified recombinant protein LaclK (LaclK was able to oxidize typical laccase substrates such as 2,6-dimethoxyphenol and l-dopamine. The characteristic adsorption maximums of typical laccases at 330 nm and 610 nm were not detected for LaclK. Cu2+ was essential for substrate oxidation, but the ratio of copper atoms/molecule of LaclK was determined to only be 1:1. Notably, the optimal temperature of LaclK was 85°C with 2,6-dimethoxyphenol as substrates, and the half-life approximately 3 days at 80°C. Furthermore, 10% (v/v organic solvents (methanol, ethanol, isopropyl alcohol, butyl alcohol, Triton x-100 or dimethyl sulfoxide could promote enzymatic activity. LaclK exhibited wide-spectrum decolorization ability towards triphenylmethane dyes, azo dyes and aromatic dyes, decolorizing 92% and 94% of Victoria Blue B (25 μM and Ethyl Violet (25 μM, respectively, at a concentration of 60 U/L after 1 h of incubation at 60°C. Overall, we characterized a novel thermostable and organic solvent-tolerant copper-containing polyphenol oxidase possessing dye-decolorizing ability. These unusual properties make LaclK an alternative for industrial applications, particularly processes that require high-temperature conditions.

  16. Screening for antibacterial and antifungal activities in some marine algae from the Fujian coast of China with three different solvents

    Science.gov (United States)

    Zheng, Yi; Chen, Yin-Shan; Lu, Hai-Sheng

    2001-12-01

    Three different solvents viz ethanol, acetone and methanol-toluene (3:1) were used to extract antibiotics from 23 species of marine algae belonging to the Chlorophyta, Phaeophyta and Rhodophyta. Their crude extracts were tested for antibacterial and antifungal activities. Among them, the ethanol extract showed the strongest activity against the bacteria and fungi tested. Four species of the Rhodophyta ( Laurencia okamurai, Dasya scoparia, Grateloupia filicina and plocamium telfairiae) showed a wide spectrum of antibacterial activity. Every solvent extract from the four species was active against all the bacteria tested. The test bacterium Pseudomonas solancearum and the fungus Penicilium citrinum were most sensitive to the extracts of marine algae. In general, the extracts of seaweeds inhibited bacteria more strongly than fungi and species of the Rhodophyta showed the greatest activity against the bacteria and fungi tested.

  17. Genetic Detection of Pseudomonas spp. in Commercial Amazonian Fish

    Science.gov (United States)

    Ardura, Alba; Linde, Ana R.; Garcia-Vazquez, Eva

    2013-01-01

    Brazilian freshwater fish caught from large drainages like the River Amazon represent a million ton market in expansion, which is of enormous importance for export to other continents as exotic seafood. A guarantee of bacteriological safety is required for international exports that comprise a set of different bacteria but not any Pseudomonas. However, diarrhoea, infections and even septicaemia caused by some Pseudomonas species have been reported, especially in immune-depressed patients. In this work we have employed PCR-based methodology for identifying Pseudomonas species in commercial fish caught from two different areas within the Amazon basin. Most fish caught from the downstream tributary River Tapajòs were contaminated by five different Pseudomonas species. All fish samples obtained from the River Negro tributary (Manaus markets) contained Pseudomonas, but a less diverse community with only two species. The most dangerous Pseudomonas species for human health, P. aeruginosa, was not found and consumption of these fish (from their Pseudomonas content) can be considered safe for healthy consumers. As a precautionary approach we suggest considering Pseudomonas in routine bacteriological surveys of imported seafood. PMID:24065035

  18. Solvent-tolerant bioconversion : Construction and analysis of a phenol producing Pseudomonas putida S12

    NARCIS (Netherlands)

    Wierckx, N.J.P.

    2009-01-01

    Organic chemicals play a fundamental role in modern civilization. Today, almost all of these chemicals are produced from oil. This leads to pollution and creates a dependency on often politically unstable oil producing countries. It is possible to make the same chemicals from sugar, using

  19. Solvent-tolerant bioconversion: Construction and analysis of a phenol producing Pseudomonas putida S12

    OpenAIRE

    Wierckx, N.J.P.

    2009-01-01

    Organic chemicals play a fundamental role in modern civilization. Today, almost all of these chemicals are produced from oil. This leads to pollution and creates a dependency on often politically unstable oil producing countries. It is possible to make the same chemicals from sugar, using microorganisms. Sugar is produced from plants, and is therefore an environmentally friendlier and almost inexhaustible resource. Unfortunately many interesting chemicals are toxic to microorganims at low con...

  20. Solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, D.M.; Latimer, E.G.

    1988-01-05

    It is an object of this invention to provide for the demetallization and general upgrading of heavy oil via a solvent extracton process, and to improve the efficiency of solvent extraction operations. The yield and demetallization of product oil form heavy high-metal content oil is maximized by solvent extractions which employ either or all of the following techniques: premixing of a minor amount of the solvent with feed and using countercurrent flow for the remaining solvent; use of certain solvent/free ratios; use of segmental baffle tray extraction column internals and the proper extraction column residence time. The solvent premix/countercurrent flow feature of the invention substantially improves extractions where temperatures and pressures above the critical point of the solvent are used. By using this technique, a greater yield of extract oil can be obtained at the same metals content or a lower metals-containing extract oil product can be obtained at the same yield. Furthermore, the premixing of part of the solvent with the feed before countercurrent extraction gives high extract oil yields and high quality demetallization. The solvent/feed ratio features of the invention substanially lower the captial and operating costs for such processes while not suffering a loss in selectivity for metals rejection. The column internals and rsidence time features of the invention further improve the extractor metals rejection at a constant yield or allow for an increase in extract oil yield at a constant extract oil metals content. 13 figs., 3 tabs.

  1. Pseudomonas-follikulitis efter badning i spabad

    DEFF Research Database (Denmark)

    Uldall Pallesen, Kristine Appel; Andersen, Klaus Ejner; Mørtz, Charlotte Gotthard

    2012-01-01

    . 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....

  2. Effects of ginseng on Pseudomonas aeruginosa motility and biofilm formation

    DEFF Research Database (Denmark)

    Wu, Hong; Lee, Baoleri; Yang, Liang

    2011-01-01

    protected animal models from developing chronic lung infection by P. aeruginosa. In the present study, the effects of ginseng on the formation of P. aeruginosa biofilms were further investigated in vitro and in vivo. Ginseng aqueous extract at concentrations of 0.5-2.0% did not inhibit the growth of P......Biofilm-associated chronic Pseudomonas aeruginosa lung infections in patients with cystic fibrosis are virtually impossible to eradicate with antibiotics because biofilm-growing bacteria are highly tolerant to antibiotics and host defense mechanisms. Previously, we found that ginseng treatments....... aeruginosa, but significantly prevented P. aeruginosa from forming biofilm. Exposure to 0.5% ginseng aqueous extract for 24 h destroyed most 7-day-old mature biofilms formed by both mucoid and nonmucoid P. aeruginosa strains. Ginseng treatment enhanced swimming and twitching motility, but reduced swarming...

  3. Study on the efficiency of the two phase partitioning stirred tank bioreactor on the toluene filtration from the airstream by Pseudomonas putida via

    Directory of Open Access Journals (Sweden)

    2013-02-01

    Full Text Available Introduction: There are different methods for controlling gaseous pollutants formed from air pollution sources that one of the most economical and efficient of them, is bio-filtration. The purpose of this study is Toluene removal from airstream by using the pure Pseudomonas putida bacteria as a fluidized bed in a two phase partitioning stirred tank bioreactor.Toluene ( Metyle benzene is one of the aromatic compounds which uses as a chemical solvent.low to moderate concentration of Toluene causes fatigue, dizziness, weakness,unbalance behaviour, memory loss, insomnia, loss of appetite, loss of vision and hearing. .Material and Method: In this experimental study at first, pure Pseudomonas putida in an aqueous phase containing nutrients and trace elements solution was duplicated and accustomed with Toluene. then solution contained microorganisms with 10% silicon oil was entered to bioreactor. The amount of CO2 and pollutant concentrations in the entrance and exhaust of bioreactor containing Pseudomonas putida was studied during 17 days for each variable. .Result: Experimental findings showed that in the 0.06 m3/h and 0.12 m3/h flow rate, the efficiency of bioreactor containing Pseudomonas putida in the concentration ranges of 283 Mg/m3 to 4710 Mg/m3 was at least 97% and 25% respectively. Statistical analysis (ANOVA showed that in two flow rates of 0.06 m3/h and 0.12 m3/h removal efficiency and mineralization percentage had significant differences .(Pvalue =0.01. .Conclusion: Achieving high efficiencies in pollutants removal was because of the prepared optimum conditions for Pseudomonas putida in the two phase partitioning stirred tank bioreactor with 10% organic phase.

  4. Canyon solvent cleaning

    International Nuclear Information System (INIS)

    Reif, D.J.

    1986-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributylphosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, produce decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown the carbonate washing, although removing residual solvent activity does not remove binding ligands that hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  5. Distribution of multi-component solvents in solvent vapor extraction chamber

    Energy Technology Data Exchange (ETDEWEB)

    Das, S. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Marathon Oil Corp., Houston, TX (United States)

    2008-10-15

    Vapex process performance is sensitive to operating pressures, temperatures and the types of solvent used. The hydrocarbon solvents used in Vapex processes typically have between 5 and 10 per cent hydrocarbon impurities, and the accumulation of dense phases inside the vapor chamber reduces gravity drainage potential. This study investigated the partitioning of solvent compounds inside the vapor chamber during in situ Vapex processes.The aim of the study was to examine how the different components of the mixed solvent partitioned inside the extracted chamber during the oil and vapor phase. A 2-D homogenous reservoir model was used to simulate the Vapex process with a solvent mixture comprised of propane and methane at various percentages. The effect of injecting a hot solvent vapor was also investigated. The study showed that injected methane accumulated at both the top and the extraction interface. Accumulations near the top had a positive impact on solvent confinement in thin reservoirs. Diffusion of the solvent component was controlled by gas phase molecular diffusion, and was much faster than the diffusion of solvent molecules in the liquid phase. The use of hot solvent mixtures slowed the extraction process due to lower solvent solubility in the oil phase. It was concluded that the negative impact on viscosity reduction by dilution was not compensated by rises in temperature. 6 refs., 11 figs.

  6. Dynamics of development and dispersal in sessile microbial communities: examples from Pseudomonas aeruginosa and Pseudomonas putida model biofilms

    DEFF Research Database (Denmark)

    Klausen, M.; Gjermansen, Morten; Kreft, J.-U.

    2006-01-01

    Surface-associated microbial communities in many cases display dynamic developmental patterns. Model biofilms formed by Pseudomonas aeruginosa and Pseudomonas putida in laboratory flow-chamber setups represent examples of such behaviour. Dependent on the experimental conditions the bacteria...

  7. Response Mechanisms in Serratia marcescens IBBPo15 During Organic Solvents Exposure.

    Science.gov (United States)

    Stancu, Mihaela Marilena

    2016-12-01

    Serratia marcescens strain IBB Po15 (KT315653) which possesses serratiopeptidase (ser) gene (KT894207) exhibited good solvent tolerance. During the exposure of S. marcescens IBB Po15 cells to 5 % organic solvents, n-decane was less toxic for this bacterium, compared with n-hexane, cyclohexane, ethylbenzene, toluene, and styrene. The exposure of the S. marcescens IBB Po15 cells to n-hexane, cyclohexane, ethylbenzene, toluene, and styrene induced the formation of large clusters, while in control and n-decane-exposed cells, only organization into small clusters was observed. The data obtained suggested that S. marcescens IBB Po15 cells produced some secondary metabolites (i.e., surfactant serrawettin, red pigment prodigiosin) which are well known as valuable molecules due to their large applications. The exposure of the bacterial cells to organic solvents induced secondary metabolites profile modifications. However, S. marcescens IBB Po15 possesses only alkB1, todM, rhlAB, pswP, mpr, and ser genes, the unspecific amplification of other fragments being acquired also when the primers for alkM1, xylM, ndoM, and C23DO genes were used. Modifications of DNA patterns were not depicted in S. marcescens IBB Po15 cells exposed to organic solvents.

  8. Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Kim, Hyung-Wook; Han, Byung Woo; Yoon, Hye-Jin; Yang, Jin Kuk; Lee, Byung Il; Lee, Hyung Ho; Ahn, Hyung Jun; Suh, Se Won

    2002-10-01

    Peptide deformylase (PDF) from the pathogenic bacterium Pseudomonas aeruginosa has been overexpressed in Escherichia coli and crystallized in the presence of its inhibitor actinonin at 297 K using polyethylene glycol (PEG) 4000 as a precipitant. The diffraction limit and the spot shape of the crystals could be slightly improved by the crystal annealing/dehydration procedure. X-ray diffraction data to 1.85 A have been collected using synchrotron radiation. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 68.75, b = 74.46, c = 77.18 A. The asymmetric unit contains two subunits of peptide deformylase, with a corresponding crystal volume per protein mass (V(M)) of 2.45 A(3) Da(-1) and a solvent content of 49.8%.

  9. Isolation and partial characterization of protease from Pseudomonas aeruginosa ATCC 27853

    Directory of Open Access Journals (Sweden)

    LIDIJA IZRAEL-ŽIVKOVIĆ

    2010-08-01

    Full Text Available Enzymatic characteristics of a protease from a medically important, referent strain of Pseudomonas aeruginosa ATCC 27853 were determined. According to sodium dodecyl sulfate polyacrylamide gel electrophoresis, SDS-PAGE, and gel filtration, it was estimated that the molecular mass of the purified enzyme was about 15 kDa. Other enzymatic properties were found to be: pH optimum 7.1, pH stability between 6.5 and 10; temperature optimum around 60 °C while the enzyme was stable at 60 °C for 30 min. Inhibition of the enzyme was observed with metal chelators, such as EDTA and 1,10-phenanthroline, suggesting that the protease is a metalloenzyme. Furthermore, the enzyme contains one mole of zinc ion per mole of enzyme. The protease was stable in the presence of different organic solvents, which enables its potential use for the synthesis of peptides.

  10. Pseudomonas fluvialis sp. nov., a novel member of the genus Pseudomonas isolated from the river Ganges, India.

    Science.gov (United States)

    Sudan, Sarabjeet Kour; Pal, Deepika; Bisht, Bhawana; Kumar, Narender; Chaudhry, Vasvi; Patil, Prabhu; Sahni, Girish; Mayilraj, Shanmugam; Krishnamurthi, Srinivasan

    2018-01-01

    A bacterial strain, designated ASS-1 T , was isolated and identified from a sediment sample of the river Ganges, Allahabad, India. The strain was Gram-stain-negative, formed straw-yellow pigmented colonies, was strictly aerobic, motile with a single polar flagellum, and positive for oxidase and catalase. The major fatty acids were C16 : 1ω7c/ 16 : 1 C16 : 1ω6c, C18 : 1ω7c and C16 : 0. Sequence analysis based on the 16S rRNA gene revealed that strain ASS-1 T showed high similarity to Pseudomonas guguanensis CC-G9A T (98.2 %), Pseudomonas alcaligenes ATCC 14909 T (98.2 %), Pseudomonas oleovorans DSM 1045 T (98.1 %), Pseudomonas indolxydans IPL-1 T (98.1 %) and Pseudomonas toyotomiensis HT-3 T (98.0 %). Analysis of its rpoB and rpoD housekeeping genes confirmed its phylogenetic affiliation and showed identities lower than 93 % with respect to the closest relatives. Phylogenetic analysis based on the 16S rRNA, rpoB, rpoD genes and the whole genome assigned it to the genus Pseudomonas. The results of digital DNA-DNA hybridization based on the genome-to-genome distance calculator and average nucleotide identity revealed low genome relatedness to its close phylogenetic neighbours (below the recommended thresholds of 70 and 95 %, respectively, for species delineation). Strain ASS-1 T also differed from the related strains by some phenotypic characteristics, i.e. growth at pH 5.0 and 42 °C, starch and casein hydrolysis, and citrate utilization. Therefore, based on data obtained from phenotypic and genotypic analysis, it is evident that strain ASS-1 T should be regarded as a novel species within the genus Pseudomonas, for which the name Pseudomonasfluvialis sp. nov. is proposed. The type strain is ASS-1 T (=KCTC 52437 T =CCM 8778 T ).

  11. Cleanup of 7.5% tributyl phosphate/n-paraffin solvent-extraction solvent

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-02-01

    The HM process at the Savannah River Plant uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials which influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands which hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM process first cycle solvent is discussed

  12. Novel organic solvent-tolerant esterase isolated by metagenomics: insights into the lipase/esterase classification Nueva esterasa tolerante a los solventes orgánicos aislada por metagenómica: ideas sobre la clasificación de las esterasas/lipasas

    Directory of Open Access Journals (Sweden)

    Renaud Berlemont

    2013-03-01

    Full Text Available In order to isolate novel organic solvent-tolerant (OST lipases, a metagenomic library was built using DNA derived from a temperate forest soil sample. A two-step activity-based screening allowed the isolation of a lipolytic clone active in the presence of organic solvents. Sequencing of the plasmid pRBest recovered from the positive clone revealed the presence of a putative lipase/esterase encoding gene. The deduced amino acid sequence (RBest1 contains the conserved lipolytic enzyme signature and is related to the previously described OST lipase from Lysinibacillus sphaericus 205y, which is the sole studied prokaryotic enzyme belonging to the 4.4 a/ß hydrolase subgroup (abH04.04. Both in vivo and in vitro studies of the substrate specificity of RBest1, using triacylglycerols or nitrophenyl-esters, respectively, revealed that the enzyme is highly specific for butyrate (C4 compounds, behaving as an esterase rather than a lipase. The RBest1 esterase was purified and biochemically characterized. The optimal esterase activity was observed at pH 6.5 and at temperatures ranging from 38 to 45 °C. Enzymatic activity, determined by hydrolysis of p-nitrophenyl esters, was found to be affected by the presence of different miscible and non-miscible organic solvents, and salts. Noteworthy, RBest1 remains significantly active at high ionic strength. These findings suggest that RBest1 possesses the ability of OST enzymes to molecular adaptation in the presence of organic compounds and resistance of halophilic proteins.Con el fin de aislar nuevas variantes de lipasas tolerantes a solventes organicos (OST, se construyo una libreria metagenomica a partir de ADN obtenido de una muestra de suelo de bosque templado. A traves de un monitoreo en dos etapas, basado en la deteccion de actividades, se aislo un clon con actividad lipolitica en presencia de solventes organicos. La secuenciacion del plasmido pRBest recuperado del clon positivo revelo la presencia de un

  13. Management and treatment of contact lens-related Pseudomonas keratitis

    Directory of Open Access Journals (Sweden)

    Willcox MD

    2012-06-01

    Full Text Available Mark DP WillcoxSchool of Optometry and Vision Science, University of New South Wales, Sydney, AustraliaAbstract: Pubmed and Medline were searched for articles referring to Pseudomonas keratitis between the years 2007 and 2012 to obtain an overview of the current state of this disease. Keyword searches used the terms "Pseudomonas" + "Keratitis" limit to "2007–2012", and ["Ulcerative" or "Microbial"] + "Keratitis" + "Contact lenses" limit to "2007–2012". These articles were then reviewed for information on the percentage of microbial keratitis cases associated with contact lens wear, the frequency of Pseudomonas sp. as a causative agent of microbial keratitis around the world, the most common therapies to treat Pseudomonas keratitis, and the sensitivity of isolates of Pseudomonas to commonly prescribed antibiotics. The percentage of microbial keratitis associated with contact lens wear ranged from 0% in a study from Nepal to 54.5% from Japan. These differences may be due in part to different frequencies of contact lens wear. The frequency of Pseudomonas sp. as a causative agent of keratitis ranged from 1% in Japan to over 50% in studies from India, Malaysia, and Thailand. The most commonly reported agents used to treat Pseudomonas keratitis were either aminoglycoside (usually gentamicin fortified with a cephalosporin, or monotherapy with a fluoroquinolone (usually ciprofloxacin. In most geographical areas, most strains of Pseudomonas sp. (≥95% were sensitive to ciprofloxacin, but reports from India, Nigeria, and Thailand reported sensitivity to this antibiotic and similar fluoroquinolones of between 76% and 90%.Keywords: Pseudomonas, keratitis, contact lens

  14. 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 expressed sRNAs across strains and species. In this study, we have used RNA-seq to identify sRNAs in P.putidaDOT-T1E and Pseudomonas extremaustralis 14-3b. This is the first strain of P.extremaustralis and the second strain of P.putida to have their transcriptomes analysed for sRNAs, and we identify...... the presence of around 150 novel sRNAs in each strain. Furthermore, we provide a comparison based on sequence conservation of all the sRNAs detected by RNA-seq in the Pseudomonas species investigated so far. Our results show that the extent of sRNA conservation across different species is very limited...

  15. Improving isopropanol tolerance and production of Clostridium beijerinckii DSM 6423 by random mutagenesis and genome shuffling.

    Science.gov (United States)

    Gérando, H Máté de; Fayolle-Guichard, F; Rudant, L; Millah, S K; Monot, F; Ferreira, Nicolas Lopes; López-Contreras, A M

    2016-06-01

    Random mutagenesis and genome shuffling was applied to improve solvent tolerance and isopropanol/butanol/ethanol (IBE) production in the strictly anaerobic bacteria Clostridium beijerinckii DSM 6423. Following chemical mutagenesis with N-methyl-N-nitro-N-nitrosoguanidine (NTG), screening of putatively improved strains was done by submitting the mutants to toxic levels of inhibitory chemicals or by screening for their tolerance to isopropanol (>35 g/L). Suicide substrates, such as ethyl or methyl bromobutyrate or alcohol dehydrogenase inhibitors like allyl alcohol, were tested and, finally, 36 mutants were isolated. The fermentation profiles of these NTG mutant strains were characterized, and the best performing mutants were used for consecutive rounds of genome shuffling. Screening of strains with further enhancement in isopropanol tolerance at each recursive shuffling step was then used to spot additionally improved strains. Three highly tolerant strains were finally isolated and able to withstand up to 50 g/L isopropanol on plates. Even if increased tolerance to the desired end product was not always accompanied by higher production capabilities, some shuffled strains showed increased solvent titers compared to the parental strains and the original C. beijerinckii DSM 6423. This study confirms the efficiency of genome shuffling to generate improved strains toward a desired phenotype such as alcohol tolerance. This tool also offers the possibility of obtaining improved strains of Clostridium species for which targeted genetic engineering approaches have not been described yet.

  16. Solvent wash solution

    International Nuclear Information System (INIS)

    Neace, J.C.

    1986-01-01

    This patent describes a process for removing diluent degradation products from a solvent extraction solution comprising an admixture of an organic extractant for uranium and plutonium and a non-polar organic liquid diluent, which has been used to recover uranium and plutonium from spent nuclear fuel. Comprising combining a wash solution consisting of: (a) water; and (b) a positive amount up to about, an including, 50 volume percent of at least one highly-polar water-miscible organic solvent, based on the total volume of the water and the highly-polar organic solvent, with the solvent extraction solution after uranium and plutonium values have been stripped from the solvent extraction solution, the diluent degradation products dissolving in the highly-polar organic solvent and the extractant and diluent of the extraction solution not dissolving in the highly-polar organic solvent, and separating the highly-polar organic solvent and the extraction solution to obtain a purified extraction solution

  17. Pseudomonas aeruginosa Trent and zinc homeostasis.

    Science.gov (United States)

    Davies, Corey B; Harrison, Mark D; Huygens, Flavia

    2017-09-01

    Pseudomonas aeruginosa is a Gram-negative pathogen and the major cause of mortality in patients with cystic fibrosis. The mechanisms that P. aeruginosa strains use to regulate intracellular zinc have an effect on infection, antibiotic resistance and the propensity to form biofilms. However, zinc homeostasis in P. aeruginosa strains of variable infectivity has not been compared. In this study, zinc homeostasis in P. aeruginosa Trent, a highly infectious clinical strain, was compared to that of a laboratory P. aeruginosa strain, ATCC27853. Trent was able to tolerate higher concentrations of additional zinc in rich media than ATCC27853. Further, pre-adaptation to additional zinc enhanced the growth of Trent at non-inhibitory concentrations but the impact of pre-adaption on the growth of ATCC27853 under the same conditions was minimal. The results establish clear differences in zinc-induced responses in Trent and ATCC27853, and how zinc homeostasis can be a promising target for the development of novel antimicrobial strategies for P. aeruginosa infection in cystic fibrosis patients. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Pseudomonas aeruginosa PAO1 exopolysaccharides are important for mixed species biofilm community development and stress tolerance

    Directory of Open Access Journals (Sweden)

    Saravanan ePeriasamy

    2015-08-01

    Full Text Available Pseudomonas aeruginosa PAO1 produces three polysaccharides, alginate, Psl and Pel that play distinct roles in attachment and biofilm formation for monospecies biofilms. Considerably less is known about their role in the development of mixed species biofilm communities. This study has investigated the roles of alginate, Psl and Pel during biofilm formation of P. aeruginosa in a defined and experimentally informative mixed species biofilm community, consisting of P. aeruginosa, Pseudomonas protegens and Klebsiella pneumoniae. Loss of the Psl polysaccharide had the biggest impact on the integration of P. aeruginosa in the mixed species biofilms, where the percent composition of the psl mutant was significantly lower (0.06% than its wild-type parent (2.44%. In contrast, loss of the Pel polysaccharide had no impact on mixed species biofilm development. Loss of alginate or its overproduction resulted in P. aeruginosa representing 8.4% and 18.11%, respectively, of the mixed species biofilm. Dual species biofilms of P. aeruginosa and K. pneumoniae were not affected by loss of alginate, Pel or Psl, while the mucoid P. aeruginosa strain achieved a greater biomass than its parent strain. When P. aeruginosa was grown with P. protegens, loss of the Pel or alginate polysaccharides resulted in biofilms that were not significantly different from biofilms formed by the wild-type PAO1. In contrast, overproduction of alginate resulted in biofilms that were comprised of 35-40% of P. aeruginosa, which was significantly higher than the wild-type (5-20%. Loss of the Psl polysaccharide significantly reduced the percentage composition of P. aeruginosa in dual species biofilms with P. protegens (<1%. Loss of the Psl polysaccharide significantly disrupted the communal stress resistance of the three species biofilms. Thus, the polysaccharide composition of an individual species significantly impacts mixed species biofilm development and the emergent properties of such

  19. Spoilage potential of Pseudomonas species isolated from goat milk.

    Science.gov (United States)

    Scatamburlo, T M; Yamazi, A K; Cavicchioli, V Q; Pieri, F A; Nero, L A

    2015-02-01

    Pseudomonas spp. are usually associated with spoilage microflora of dairy products due to their proteolytic potential. This is of particular concern for protein-based products, such as goat milk cheeses and fermented milks. Therefore, the goal of the present study was to characterize the proteolytic activity of Pseudomonas spp. isolated from goat milk. Goat milk samples (n=61) were obtained directly from bulk tanks on dairy goat farms (n=12), and subjected to a modified International Organization for Standardization (ISO) protocol to determine the number and proteolytic activity of Pseudomonas spp. Isolates (n=82) were obtained, identified by PCR, and subjected to pulsed-field gel electrophoresis with XbaI macro-restriction. Then, the isolates were subjected to PCR to detect the alkaline protease gene (apr), and phenotypic tests were performed to check proteolytic activity at 7°C, 25°C, and 35°C. Mean Pseudomonas spp. counts ranged from 2.9 to 4.8 log cfu/mL, and proteolytic Pseudomonas spp. counts ranged from 1.9 to 4.6 log cfu/mL. All isolates were confirmed to be Pseudomonas spp., and 41 were identified as Pseudomonas fluorescens, which clustered into 5 groups sharing approximately 82% similarity. Thirty-six isolates (46.9%) were positive for the apr gene; and 57 (69.5%) isolates presented proteolytic activity at 7°C, 82 (100%) at 25°C, and 64 (78%) at 35°C. The isolates were distributed ubiquitously in the goat farms, and no relationship among isolates was observed when the goat farms, presence of apr, pulsotypes, and proteolytic activity were taken into account. We demonstrated proteolytic activity of Pseudomonas spp. present in goat milk by phenotypic and genotypic tests and indicated their spoilage potential at distinct temperatures. Based on these findings and the ubiquity of Pseudomonas spp. in goat farm environments, proper monitoring and control of Pseudomonas spp. during production are critical. Copyright © 2015 American Dairy Science Association

  20. Interaction of bacteria-feeding soil flagellates and Pseudomonas spp

    DEFF Research Database (Denmark)

    Pedersen, Annette; Ekelund, Flemming; Johansen, Anders

    2010-01-01

    Pseudomonas strains may be used as alternatives to fungicides as some of them produce secondary metabolites, which can inhibit growth of plant pathogenic fungi. Increased knowledge of non-target effects of the antagonistic bacteria on other soil organisms as well as of the survival and predation...... resistance of the antagonistic bacteria is necessary for risk assessment and increased performance of antagonistic bacteria as biological control agents. In the present study, we aimed to investigate the difference between Pseudomonas spp. with respect to their predation resistance to and effects...... on the three different and common soil flagellates Bodo caudatus, Cercomonas longicauda, and Neocercomonas jutlandica. Two antagonistic Pseudomonas: Pseudomonas fluorescens CHA0 and P. fluorescens DR54 and two positive control strains: P. fluorescens DSM 50090T and Pseudomonas chlororaphis ATCC 43928 were...

  1. Occurrence of pseudomonas aeruginosa in post-operative wound infection

    International Nuclear Information System (INIS)

    Oguntibeju, O.O.; Nwobu, R.A.U.

    2004-01-01

    Objective: To determine the prevalence of Pseudomonas aeruginosa in post-operative wound infection. Results: Out of the 60 bacterial isolates found in post-operative wound infection, 20 (33.3%) were Pseudomonas aeruginosa, followed by Staphylococcus aureus 13(21.7%), Klebsiella species 10(16.7%), Escherichia coli 7(11.7%), Atypical coliform 4(6.7%), Proteus species 4(6.7%), Streptococcus pyogenes 1(1.7%) and Enterococcus faecalis 1(1.7%) in the order. Pseudomonas aeruginosa infections was higher in female than male, ratio 3:2 and was found more among young and elderly debilitated patients. The in vitro sensitivity pattern of 20 isolates of Pseudomonas aeruginosa showed colistin (100%), gentamicin (75%), streptomycin (30%), and tetracycline (10%). Conclusion: The role of Pseudomonas aeruginosa as an agent of nosocomial infection is re-emphasised. (author)

  2. 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....

  3. Screening of Gibberellic Acid Production by Pseudomonas SPP

    International Nuclear Information System (INIS)

    Khine Zar Wynn Myint; Khin Mya Lwin; Myo Myint

    2010-12-01

    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.

  4. Advances of naphthalene degradation in Pseudomonas putida ND6

    Science.gov (United States)

    Song, Fu; Shi, Yifei; Jia, Shiru; Tan, Zhilei; Zhao, Huabing

    2018-03-01

    Naphthalene is one of the most common and simple polycyclic aromatic hydrocarbons. Degradation of naphthalene has been greatly concerned due to its economic, free-pollution and its fine effect in Pseudomonas putida ND6. This review summarizes the development history of naphthalene degradation, the research progress of naphthalene degrading gene and naphthalene degradation pathway of Pseudomonas putida ND6, and the researching path of this strain. Although the study of naphthalene degradation is not consummate in Pseudomonas putida ND6, there is a potential capability for Pseudomonas putida ND6 to degrade the naphthalene in the further research.

  5. Heterogeneity of heat-resistant proteases from milk Pseudomonas species.

    Science.gov (United States)

    Marchand, Sophie; Vandriesche, Gonzalez; Coorevits, An; Coudijzer, Katleen; De Jonghe, Valerie; Dewettinck, Koen; De Vos, Paul; Devreese, Bart; Heyndrickx, Marc; De Block, Jan

    2009-07-31

    Pseudomonas fragi, Pseudomonas lundensis and members of the Pseudomonas fluorescens group may spoil Ultra High Temperature (UHT) treated milk and dairy products, due to the production of heat-stable proteases in the cold chain of raw milk. Since the aprX gene codes for a heat-resistant protease in P. fluorescens, the presence of this gene has also been investigated in other members of the genus. For this purpose an aprX-screening PCR test has been developed. Twenty-nine representatives of important milk Pseudomonas species and thirty-five reference strains were screened. In 42 out of 55 investigated Pseudomonas strains, the aprX gene was detected, which proves the potential of the aprX-PCR test as a screening tool for potentially proteolytic Pseudomonas strains in milk samples. An extensive study of the obtained aprX-sequences on the DNA and the amino acid level, however, revealed a large heterogeneity within the investigated milk isolates. Although this heterogeneity sets limitations to a general detection method for all proteolytic Pseudomonas strains in milk, it offers a great potential for the development of a multiplex PCR screening test targeting individual aprX-genes. Furthermore, our data illustrated the potential use of the aprX gene as a taxonomic marker, which may help in resolving the current taxonomic deadlock in the P. fluorescens group.

  6. Phenotypes of non-attached Pseudomonas aeruginosa aggregates resemble surface attached biofilm.

    Directory of Open Access Journals (Sweden)

    Morten Alhede

    Full Text Available For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse conditions. However, microscopic investigations of samples isolated from sites of chronic infections seem to suggest that some bacteria do not need to be attached to surfaces in order to establish chronic infections. In this study we employed scanning electron microscopy, confocal laser scanning microscopy, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance and resistance to phagocytes were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both the physiological states of the aggregates and particular matrix components. Bacterial surface-attachment and subsequent biofilm formation are considered hallmarks of the capacity of microbes to cause persistent infections. We have observed non-attached aggregates in the lungs of cystic fibrosis patients; otitis media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non

  7. Solvent extraction of Zn and metals in Zn ores by nonphosphorous solvents

    International Nuclear Information System (INIS)

    Auchapt, J.M.; Tostain, Jacqueline.

    1975-07-01

    This bibliography follows a first work on Zn solvent extraction by organo-phosphorous compounds. The other solvents used in Zn extraction, are studied: oxygenated nonphosphorous solvents (ketones, alcohols, carboxylic acids, sulfonates), nitrogenous solvents and hydrocarbons [fr

  8. Pseudomonas Septic Arthritis | Thanni | Nigerian Journal of ...

    African Journals Online (AJOL)

    BACKGROUND: Septic arthritis due to pseudomonas species is unusual and when it occurs, there is often an underlying cause like immune depression, intravenous drug abuse or a penetrating injury. PATIENT AND METHOD: We report a case of pseudomonas septic arthritis complicating cannulation of a leg vein following ...

  9. Solvent substitution

    International Nuclear Information System (INIS)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

  10. Pigments influence the tolerance of Pseudomonas aeruginosa PAO1 to photodynamically induced oxidative stress

    DEFF Research Database (Denmark)

    Orlandi, Viviana T; Bolognese, Fabrizio; Chiodaroli, Luca

    2015-01-01

    by exogenous photosensitizers and visible light. To evaluate whether P. aeruginosa pigments can contribute to its relative tolerance to PDT, we analysed the response to this treatment of isogenic transposon mutants of P. aeruginosa PAO1 with altered pigmentation. In general, in the presence of pigments...

  11. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    Science.gov (United States)

    Horváth, Anikó; Futó, István; Palcsu, László

    2014-05-01

    Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

  12. Experimental Pseudomonas aeruginosa mediated rhino sinusitis in mink

    DEFF Research Database (Denmark)

    Kirkeby, S.; Hammer, A. S.; Høiby, N.

    2017-01-01

    The nasal and sinus cavities in children may serve as reservoirs for microorganisms that cause recurrent and chronic lung infections. This study evaluates whether the mink can be used as an animal model for studying Pseudomonas aeruginosa mediated rhino-sinusitis since there is no suitable...... in the infected mink shows features of carbohydrate expression comparable to what has been described in the respiratory system after Pseudomonas aeruginosa infection in humans. It is suggested that the mink is suitable for studying Pseudomonas aeruginosa mediated rhino-sinusitis....

  13. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

    Directory of Open Access Journals (Sweden)

    Deepthy Alex

    2014-01-01

    Full Text Available Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol.

  14. 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...

  15. 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...

  16. Structural characterization of pyoverdines produced by Pseudomonas putida KT2440 and Pseudomonas taiwanensis VLB120.

    Science.gov (United States)

    Baune, Matthias; Qi, Yulin; Scholz, Karen; Volmer, Dietrich A; Hayen, Heiko

    2017-08-01

    The previously unknown sequences of several pyoverdines (PVD) produced by a biotechnologically-relevant bacterium, namely, Pseudomonas taiwanensis VLB120, were characterized by high performance liquid chromatography (HPLC)-high resolution mass spectrometry (HRMS). The same structural characterization scheme was checked before by analysis of Pseudomonas sp. putida KT2440 samples with known PVDs. A new sample preparation strategy based on solid-phase extraction was developed, requiring significantly reduced sample material as compared to existing methods. Chromatographic separation was performed using hydrophilic interaction liquid chromatography with gradient elution. Interestingly, no signals for apoPVDs were detected in these analyses, only the corresponding aluminum(III) and iron(III) complexes were seen. The chromatographic separation readily enabled separation of PVD complexes according to their individual structures. HPLC-HRMS and complementary fragmentation data from collision-induced dissociation and electron capture dissociation enabled the structural characterization of the investigated pyoverdines. In Pseudomonas sp. putida KT2240 samples, the known pyoverdines G4R and G4R A were readily confirmed. No PVDs have been previously described for Pseudomonas sp. taiwanensis VLB120. In our study, we identified three new PVDs, which only differed in their acyl side chains (succinic acid, succinic amide and malic acid). Peptide sequencing by MS/MS provided the sequence Orn-Asp-OHAsn-Thr-AcOHOrn-Ser-cOHOrn. Of particular interest is the presence of OHAsn, which has not been reported as PVD constituent before.

  17. High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa antibiotic resistance in immunocompromised hosts: evidence from outbreak investigation

    Directory of Open Access Journals (Sweden)

    D'Arezzo Silvia

    2012-01-01

    Full Text Available Abstract Background and methods Pseudomonas aeruginosa is a major infectious threat to immunocompromised patients. We recently reported a fatal epidemic of multidrug-resistant P. aeruginosa in an onchoematology unit, linked to massive contamination of a triclosan-based disinfectant. The aim of this study is to evaluate the antimicrobial activity of triclosan and chlorhexidine digluconate against the epidemic strain of P. aeruginosa, to confirm the hypothesis that the soap dispenser acted as a continuous source of the infection during the outbreak, and to explore the potential role of triclosan in increasing the level of resistance to selected antibiotics. Susceptibility tests and time-kill assays for disinfectans were performed using two commercial formulations containing triclosan and chlorhexidine digluconate, respectively. Antibiotic susceptibility testing was performed by the broth microdilution method. Findings The P. aeruginosa epidemic strain exhibited an extremely high level of triclosan resistance (apparent MIC = 2,125 mg/L, while it was markedly susceptible to chlorhexidine digluconate (apparent MIC = 12.5 mg/L. Upon gradual adaptation to triclosan, the epidemic strain survived for a long period (> 120 h in the presence of 3,400 mg/L (equivalent to 1.6 × MIC of triclosan, concomitantly increasing the resistance to six antibiotics that are typical substrates of drug efflux pumps of the resistance nodulation division family. This effect was reversed by efflux pump inhibitors. Conclusions The epidemic P. aeruginosa strain was resistant to triclosan and its previous exposure to triclosan increases antibiotic resistance, likely through active efflux mechanisms. Since P. aeruginosa can become tolerant to elevated triclosan concentrations, the use of triclosan-based disinfectants should be avoided in those healthcare settings hosting patients at high risk for P. aeruginosa infection.

  18. Exploiting Sequential Injection on-line Solvent Extraction/Back Extraction with Detection by ETAAS or ICPMS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    presents an on-line SI-solvent extraction/back extraction procedure used in connection with detection by either ETAAS or ICPMS. Incorporating two newly designed dual-conical gravitational phase separators, its performance is demonstrated for the determination of various metals in reference materials.......Electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are highly sensitive techniques for trace metal analyses. Nevertheless, separation/preconcentration procedures are often called for in order to overcome their inherent low matrix...... tolerances. With detection by ETAAS, separation/preconcentration by solvent extraction has enjoyed much use. However, this approach is not necessarily the optimal one since introduction of organic eluates directly into the graphite tube might lead to deteriorated reproducibility and lower sensitivity...

  19. Solvent/Non-Solvent Sintering To Make Microsphere Scaffolds

    Science.gov (United States)

    Laurencin, Cato T.; Brown, Justin L.; Nair, Lakshmi

    2011-01-01

    A solvent/non-solvent sintering technique has been devised for joining polymeric microspheres to make porous matrices for use as drug-delivery devices or scaffolds that could be seeded with cells for growing tissues. Unlike traditional sintering at elevated temperature and pressure, this technique is practiced at room temperature and pressure and, therefore, does not cause thermal degradation of any drug, protein, or other biochemical with which the microspheres might be loaded to impart properties desired in a specific application. Also, properties of scaffolds made by this technique are more reproducible than are properties of comparable scaffolds made by traditional sintering. The technique involves the use of two miscible organic liquids: one that is and one that is not a solvent for the affected polymer. The polymeric microspheres are placed in a mold having the size and shape of the desired scaffold, then the solvent/non-solvent mixture is poured into the mold to fill the void volume between the microspheres, then the liquid mixture is allowed to evaporate. Some of the properties of the resulting scaffold can be tailored through choice of the proportions of the liquids and the diameter of the microspheres.

  20. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  1. A combined interfacial and in-situ polymerization strategy to construct well-defined core-shell epoxy-containing SiO2-based microcapsules with high encapsulation loading, super thermal stability and nonpolar solvent tolerance

    Directory of Open Access Journals (Sweden)

    Yin Jia

    2016-10-01

    Full Text Available SiO2-based microcapsules containing hydrophobic molecules exhibited potential applications such as extrinsic self-healing, drug delivery, due to outstanding thermal and chemical stability of SiO2. However, to construct SiO2-based microcapsules with both high encapsulation loading and long-term structural stability is still a troublesome issue, limiting their further utilization. We herein design a single-batch route, a combined interfacial and in-situ polymerization strategy, to fabricate epoxy-containing SiO2-based microcapsules with both high encapsulation loading and long-term structural stability. The final SiO2-based microcapsules preserve high encapsulation loading of 85.7 wt% by controlling exclusively hydrolysis and condensed polymerization at oil/water interface in the initial interfacial polymerization step. In the subsequent in-situ polymerization step, the initial SiO2-based microcapsules as seeds could efficiently harvest SiO2 precursors and primary SiO2 particles to finely tune the SiO2 wall thickness, thereby enhancing long-term structural stability of the final SiO2-based microcapsules including high thermal stability with almost no any weight loss until 250°C, and strong tolerance against nonpolar solvents such as CCl4 with almost unchanged core-shell structure and unchanged core weight after immersing into strong solvents for up to 5 days. These SiO2-based microcapsules are extremely suited for processing them into anticorrosive coating in the presence of nonpolar solvents for self-healing application.

  2. Expression of recombinant Pseudomonas stutzeri di-heme cytochrome c(4) by high-cell-density fed-batch cultivation of Pseudomonas putida

    DEFF Research Database (Denmark)

    Thuesen, Marianne Hallberg; Nørgaard, Allan; Hansen, Anne Merete

    2003-01-01

    The gene of the di-heme protein cytochrome c(4) from Pseudomonas stutzeri was expressed in Pseudomonas putida. High-yield expression of the protein was achieved by high-cell-density fed-batch cultivation using an exponential glucose feeding strategy. The recombinant cytochrome c(4) protein...

  3. Solvents and solvent effects in organic chemistry

    National Research Council Canada - National Science Library

    Reichardt, C; Welton, T

    2011-01-01

    .../guest complexation equilibria and reactions in biphasic solvent systems and neoteric solvents, respectively. More than 900 new references have been added, giving preference to review articles, and many older ones have been deleted. New references either replace older ones or are added to the end of the respective reference list of each chapter. Th...

  4. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.

    2002-10-08

    This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.

  5. Induced tolerance to nebulized colistin after severe reaction to the drug.

    Science.gov (United States)

    Domínguez-Ortega, J; Manteiga, E; Abad-Schilling, C; Juretzcke, M A; Sánchez-Rubio, J; Kindelan, C

    2007-01-01

    Daily nebulized colistin therapy has been used as maintenance therapy for patients with chronic Pseudomonas aeruginosa infection and in treatment protocols aimed at eradicating early P aeruginosa infection. Colistin-induced nephrotoxicity and mild neurotoxic effects have been described but hypersensitivity reactions are rare. However, bronchial constriction has been reported associated with the inhalation of the antibiotic. We report the case of a 63-year-old man who had been diagnosed with bronchiectasis and bronchopleural fistula and who developed severe bronchospasm when using nebulized colistin. A skin prick test (80 mg/mL) with colistin was performed and was negative. An intradermal test was not performed due to its possible irritant effect. As our patient suffered from a tobramycin-resistant P aeruginosa infection, we started a procedure to induce tolerance to 80 mg colistin (8 mg, 16 mg, 24 mg, 32 mg, 40 mg, 80 mg) nebulized in 30-minutes-intervals. No changes in forced expiratory volume in 1 second values were observed and the patient continues on treatment twice daily after the tolerance induction with no new episodes of bronchospasm. We report the first successful procedure to induce tolerance to colistin after escalating doses of inhaled colistin.

  6. 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

  7. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    Energy Technology Data Exchange (ETDEWEB)

    McCarty, P. L.; Spormann, Alfred M.; Criddle, Craig, S.

    2003-12-11

    three to five times, leading to a more rapid clean-up of the DNAPL zone. The most favored electron donor to add is one which partitions well with the chlorinated solvent or can be concentrated near it. Unfortunately, an ideal electron donor, such as vegetable oil, is difficult to introduce and mix with DNAPL in the ground, doing this properly remains an engineering challenge. Numerical model studies have indicated that several factors may significantly influence the rate and extent of enhancement, including the inhibitory effects of PCE and cDCE, the level of ED concentration, DNAPL configuration, and competition for ED. Such factors need to be considered when contemplating engineered DNAPL bioremediation. Pseudomonas stuzeri KC is an organism that transforms CT to carbon dioxide and chloride without the formation of the hazardous intermediate, chloroform. This is accomplished by production and secretion of a molecule called PDTC. This study was direct ed towards determining how PDTC works. Cu (II) at a ratio of 1:1 Cu to PDTC was found to result in the most rapid CT transformation, confirming that the PDTC-Cu complex is both a reactant and a catalyst in CT transformation. CT degradation requires that the PDTC be in a reduced form, which is generated by contact with cell components. Fe(II) inhibits CT transformation by PDTC. Studies indicated that this inhibition is enhanced by some compound or factor in the supernatant with molecular weight greater than 10,000 Da. We have made progress in determining what this factor might be, but have not yet been able to identify it. In related studies, we found that CT transformation by another organism, Shewanella oneidensis MR1, also involves an excreted factor, but this factor is different from PDTC and results in chloroform transformation as an intermediate. Our studies have indicated that this factor is similar to vitamin K2, and we have also confirmed that vitamin K2 does transform C T into chloroform.

  8. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    International Nuclear Information System (INIS)

    McCarty, P. L.; Spormann, Alfred M.; Criddle, Craig S.

    2003-01-01

    three to five times, leading to a more rapid clean-up of the DNAPL zone. The most favored electron donor to add is one which partitions well with the chlorinated solvent or can be concentrated near it. Unfortunately, an ideal electron donor, such as vegetable oil, is difficult to introduce and mix with DNAPL in the ground, doing this properly remains an engineering challenge. Numerical model studies have indicated that several factors may significantly influence the rate and extent of enhancement, including the inhibitory effects of PCE and cDCE, the level of ED concentration, DNAPL configuration, and competition for ED. Such factors need to be considered when contemplating engineered DNAPL bioremediation. Pseudomonas stuzeri KC is an organism that transforms CT to carbon dioxide and chloride without the formation of the hazardous intermediate, chloroform. This is accomplished by production and secretion of a molecule called PDTC. This study was direct ed towards determining how PDTC works. Cu (II) at a ratio of 1:1 Cu to PDTC was found to result in the most rapid CT transformation, confirming that the PDTC-Cu complex is both a reactant and a catalyst in CT transformation. CT degradation requires that the PDTC be in a reduced form, which is generated by contact with cell components. Fe(II) inhibits CT transformation by PDTC. Studies indicated that this inhibition is enhanced by some compound or factor in the supernatant with molecular weight greater than 10,000 Da. We have made progress in determining what this factor might be, but have not yet been able to identify it. In related studies, we found that CT transformation by another organism, Shewanella oneidensis MR1, also involves an excreted factor, but this factor is different from PDTC and results in chloroform transformation as an intermediate. Our studies have indicated that this factor is similar to vitamin K2, and we have also confirmed that vitamin K2 does transform C T into chloroform

  9. 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

  10. Novel Targets for Treatment of Pseudomonas aeruginosa Biofilms

    DEFF Research Database (Denmark)

    Alhede, Morten; Alhede, Maria; Bjarnsholt, Thomas

    2014-01-01

    Pseudomonas aeruginosa causes infection in all parts of the human body. The bacterium is naturally resistant to a wide range of antibiotics. In addition to resistance mechanisms such as efflux pumps, the ability to form aggregates, known as biofilm, further reduces Pseudomonas aeruginosa...

  11. The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

    CERN Document Server

    Lagowski, J J

    1976-01-01

    The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

  12. Pseudomonas tarimensis sp. nov., an endophytic bacteria isolated from Populus euphratica.

    Science.gov (United States)

    Anwar, Nusratgul; Rozahon, Manziram; Zayadan, Bolatkhan; Mamtimin, Hormathan; Abdurahman, Mehfuzem; Kurban, Marygul; Abdurusul, Mihribangul; Mamtimin, Tursunay; Abdukerim, Muhtar; Rahman, Erkin

    2017-11-01

    An endophytic bacterium, MA-69 T , was isolated from the storage liquid in the stems of Populuseuphratica trees at the ancient Ugan River in Xinjiang, PR China. Strain MA-69 T was found to be short rod-shaped, Gram-stain-negative, non-spore-forming, aerobic and motile by means of a monopolar flagellum. According to phylogenetic analysis based on 16S rRNA gene sequences, strain MA-69 T was assigned to the genus Pseudomonas with highest 16S rRNA gene sequence similarity of 97.5 % to Pseudomonas azotifigens JCM 12708 T , followed by Pseudomonas matsuisoli JCM 30078 T (97.5 %), Pseudomonas balearica DSM 6083 T (97.1 %), Azotobacter salinestris ATCC 49674 T (96.1 %) and Pseudomonas indica DSM 14015 T (95.9 %). Analysis of strain MA-69 T based on the three housekeeping genes, rpoB, rpoD and gyrB, further confirmed the isolate to be distinctly delineated from species of the genus Pseudomonas. The DNA G+C content of strain MA-69 T was 64.1 mol%. DNA-DNA hybridization with Pseudomonas azotifigens JCM 12708 T , Pseudomonas matsuisoli JCM 30078 T and Pseudomonas balearica DSM 6083 T revealed 62.9, 60.1 and 49.0 % relatedness, respectively. The major fatty acids in strain MA-69 T were summed feature 3 (25.7 %), summed feature 8 (24.0 %), C19 : 0cyclo ω8c (19.9 %), C16 : 0 (14.6 %) and C12 : 0 (6.3 %). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Q-9 was the major quinone in strain MA-69 T . Based on phenotypic, chemotaxonomic and phylogenetic properties, strain MA-69 T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas tarimensis sp. nov. is proposed. The type strain is MA-69 T (=CCTCC AB 2013065 T =KCTC 42447 T ).

  13. A solvent/non-solvent system for achieving solution-processed multilayer organic light-emitting devices

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yue; Wu, Zhaoxin, E-mail: zhaoxinwu@mail.xjtu.edu.cn; He, Lin; Jiao, Bo; Hou, Xun

    2015-08-31

    We developed a solvent/non-solvent system to fabricate the multilayer organic light-emitting devices (OLEDs) based on poly(N-vinylcarbazole) (PVK) by solution-process. This solvent system consists of both the solvent and non-solvent of PVK, in which fluorescent small molecules could be fully dissolved and directly spin-coated on top of the PVK layer; it could effectively avoid the redissolution of PVK during the spin-coating process of small molecules emitting layer. In the further investigation of this system, we also demonstrated the three-component solvent system, and found out that the third component, a less volatile solvent of PVK, was crucial for preparing a smoother interface between PVK and emitting layer. Compared with OLEDs through the vacuum deposition, the devices fabricated by solution-process from the solvent/non-solvent system showed comparable efficiency, which indicate that the solvent/non-solvent system can be used as an alternative process to prepare the polymer and small molecule multilayer devices through all-solution-process. - Highlights: • We fabricate the multilayer OLEDs by solution-process using a novel system. • We develop a solvent/non-solvent system of polymer (PVK) to avoid redissolution. • Small molecules could be fully dissolved and directly spin-coated on PVK layer. • The devices fabricated by the system and vacuum deposition show comparable efficiency.

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

    International Nuclear Information System (INIS)

    Siva Prasath, C.S.; Manikandan, N.; Prakash, S.

    2010-01-01

    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)

  15. Co-silencing of tomato S-adenosylhomocysteine hydrolase genes confers increased immunity against Pseudomonas syringae pv. tomato DC3000 and enhanced tolerance to drought stress

    Directory of Open Access Journals (Sweden)

    Li Xiao Hui

    2015-09-01

    Full Text Available S-adenosylhomocysteine hydrolase (SAHH, catalyzing the reversible hydrolysis of S-adenosylhomocysteine to adenosine and homocysteine, is a key enzyme that maintain the cellular methylation potential in all organisms. We report here the biological functions of tomato SlSAHHs in stress response. The tomato genome contains three SlSAHH genes that encode SlSAHH proteins with high level of sequence identity. qRT-PCR analysis revealed that SlSAHHs responded with distinct expression induction patterns to Pseudomonas syringae pv. tomato (Pst DC3000 and Botrytis cinerea as well as to defense signaling hormones such as salicylic acid, jasmonic acid and a precursor of ethylene. Virus-induced gene silencing-based knockdown of individual SlSAHH gene did not affect the growth performance and the response to Pst DC3000. However, co-silencing of three SlSAHH genes using a conserved sequence led to significant inhibition of vegetable growth. The SlSAHH-co-silenced plants displayed increased resistance to Pst DC3000 but did not alter the resistance to B. cinerea. Co-silencing of SlSAHHs resulted in constitutively activated defense responses including elevated SA level, upregulated expression of defense-related and PAMP-triggered immunity marker genes and increased callose deposition and H2O2 accumulation. Furthermore, the SlSAHH-co-silenced plants also exhibited enhanced drought stress tolerance although they had relatively small roots. These data demonstrate that, in addition to the functions in growth and development, SAHHs also play important roles in regulating biotic and abiotic stress responses in plants.

  16. REPARAÇÃO DE α-ACETILOXI-N-CICLOEXILAMIDAS ATRAVÉS DA REAÇÃO DE PASSERINI UTILIZANDO DIMETILCARBONATO COMO SOLVENTE AMBIENTALMENTE AMIGÁVEL

    Directory of Open Access Journals (Sweden)

    Bárbara R. Oliveira

    Full Text Available A series of α-acetyloxy-N-cyclohexylamides was efficiently obtained via Passerini reaction of cyclohexyl isocyanide, acetic acid, and different aromatic and aliphatic aldehydes using refluxing dichloromethane or dimethylcarbonate (DMC. Reactions performed with DMC led to desired products in moderate to good yields, corroborating this solvent as a eco-friendly alternative to the chlorinated solvents commonly used in this transformation. The α-acetyloxy-N-cyclohexylamides thus obtained were tested against Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa, and Staphylococcus aureus, as well as promastigote forms of L.(L. amazonensis. The α-(Acetyloxy-N-cyclohexyl-pentanamide showed low antibacterial activity against Gram-positive (S. aureus and B. cereus and Gram negative (E. coli and P. aeruginosa bacteria (MIC = 8,3-16,5 mmol L-1, while α-(acetyloxy-N-cyclohexyl-4-bromo-benzeneacetamide showed leishmanicidal activitity (IC50 = 0,099 mmol L-1.

  17. 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

  18. Exploiting sequential injection on-line solvent extraction/back extraction with detection by ETAAS and ICPMS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    presents an on-line SI-solvent extraction/back extraction procedure used in connection with detection by either ETAAS or ICPMS. Incorporating two newly designed dual-conical gravitational phase separators, its performance is demonstrated for the determination of various metals in reference materials.......Electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are highly sensitive techniques for trace metal analyses. Nevertheless, separation/preconcentration procedures are often called for in order to overcome their inherent low matrix tolerance....... With detection by ETAAS, separation/preconcentration by solvent extraction has enjoyed much use. However, this approach is not necessarily the optimal one since introduction of organic eluates directly into the graphite tube might lead to deteriorated reproducibility and lower sensitivity. And for ICPMS...

  19. Functional bacterial amyloid increases Pseudomonas biofilm hydrophobicity and stiffness

    DEFF Research Database (Denmark)

    Zeng, Guanghong; Vad, Brian S; Dueholm, Morten S

    2015-01-01

    The success of Pseudomonas species as opportunistic pathogens derives in great part from their ability to form stable biofilms that offer protection against chemical and mechanical attack. The extracellular matrix of biofilms contains numerous biomolecules, and it has recently been discovered...... that in Pseudomonas one of the components includes β-sheet rich amyloid fibrils (functional amyloid) produced by the fap operon. However, the role of the functional amyloid within the biofilm has not yet been investigated in detail. Here we investigate how the fap-based amyloid produced by Pseudomonas affects biofilm...... hydrophobicity and mechanical properties. Using atomic force microscopy imaging and force spectroscopy, we show that the amyloid renders individual cells more resistant to drying and alters their interactions with hydrophobic probes. Importantly, amyloid makes Pseudomonas more hydrophobic and increases biofilm...

  20. Interactions between polymorphonuclear leukocytes and Pseudomonas aeruginosa biofilms on silicone implants in vivo

    DEFF Research Database (Denmark)

    van Gennip, Maria; Hultqvist, Louise Dahl; Alhede, Morten

    2012-01-01

    (PMNs). In contrast, the number of cells of a P. aeruginosa rhlA mutant that cannot produce rhamnolipids was significantly reduced on the implants by day 1, and the bacteria were actively phagocytosed by infiltrating PMNs. In addition, we identified extracellular wire-like structures around the bacteria......Chronic infections with Pseudomonas aeruginosa persist because the bacterium forms biofilms that are tolerant to antibiotic treatment and the host immune response. Scanning electron microscopy and confocal laser scanning microscopy were used to visualize biofilm development in vivo following...... intraperitoneal inoculation of mice with bacteria growing on hollow silicone tubes, as well as to examine the interaction between these bacteria and the host innate immune response. Wild-type P. aeruginosa developed biofilms within 1 day that trapped and caused visible cavities in polymorphonuclear leukocytes...

  1. Enhanced Enzymatic Synthesis of a Cephalosporin, Cefadroclor, in the Presence of Organic Co-solvents.

    Science.gov (United States)

    Liu, Kun; Li, Sha; Pang, Xiao; Xu, Zheng; Li, Dengchao; Xu, Hong

    2017-05-01

    In this study, we investigated the enzymatic synthesis of a semi-synthetic cephalosporin, cefadroclor, from 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid (7-ACCA) and p-OH-phenylglycine methyl ester (D-HPGM) using immobilized penicillin G acylase (IPA) in organic co-solvents. Ethylene glycol (EG) was employed as a component of the reaction mixture to improve the yield of cefadroclor. EG was found to increase the yield of cefadroclor by 15-45%. An investigation of altered reaction parameters including type and concentration of organic solvents, pH of reaction media, reaction temperature, molar ratio of substrates, enzyme loading, and IPA recycling was carried out in the buffer mixture. The best result was a 76.5% conversion of 7-ACCA, which was obtained from the reaction containing 20% EG (v/v), D-HPGM to 7-ACCA molar ratio of 4:1 and pH 6.2, catalyzed by 16 IU mL -1 IPA at 20 °C for 10 h. Under the optimum conditions, no significant loss of IPA activity was found after seven repeated reaction cycles. In addition, cefadroclor exhibited strong inhibitory activity against yeast, Bacillus subtilis NX-2, and Escherichia coli and weaker activity against Staphylococcus aureus and Pseudomonas aeruginosa. Cefadroclor is a potential antibiotic with activity against common pathogenic microorganisms.

  2. Bubbles in solvent microextraction: the influence of intentionally introduced bubbles on extraction efficiency.

    Science.gov (United States)

    Williams, D Bradley G; George, Mosotho J; Meyer, Riaan; Marjanovic, Ljiljana

    2011-09-01

    Significant improvements to microdrop extractions of triazine pesticides are realized by the intentional incorporation of an air bubble into the solvent microdroplet used in this microextraction technique. The increase is attributed partly to greater droplet surface area resulting from the air bubble being incorporated into the solvent droplet as opposed to it sitting thereon and partly to thin film phenomena. The method is useful at nanogram/liter levels (LOD 0.002-0.012 μg/L, LOQ 0.007-0.039 μg/L), is precise (7-12% at 10 μg/L concentration level), and is validated against certified reference materials containing 0.5 and 5.0 μg/L analyte. It tolerates water and fruit juice as matrixes without serious matrix effects. This new development brings a simple, inexpensive, and efficient preconcentration technique to bear which rivals solid phase microextraction methods.

  3. Analysis of solvent extracts from coal liquefaction in a flowing solvent reactor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wen-Ying; Feng, Jie; Xie, Ke-Chang [Key Laboratory of Coal Science and Technology, Taiyuan University of Technology, Ministry of Education and Shanxi Province, No. 79 Yingze West Street, Taiyuan 030024 (China); Kandiyoti, R. [Department of Chemical Engineering and Chemical Technology, Imperial College, University of London, London SW7 2BY (United Kingdom)

    2004-10-15

    Point of Ayr coal has been extracted using three solvents, tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP) at two temperatures 350 and 450 C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. The three solvents differ in solvent power and the ability to donate hydrogen atoms to stabilise free radicals produced by pyrolysis of the coal. The extracts were prepared in a flowing solvent reactor to minimise secondary thermal degradation of the primary extracts. Analysis of the pentane-insoluble fractions of the extracts was achieved by size exclusion chromatography, UV-fluorescence spectroscopy in NMP solvent and probe mass. With increasing extraction temperature, the ratio of the amount having big molecular weight to that having small molecular weight in tetralin extracts was increased; the tetralin extract yield increased from 12.8% to 75.9%; in quinoline, increasing extraction temperature did not have an effect on the molecular weight of products but there was a big increase in extract yield. The extracts in NMP showed the enhanced solvent extraction power at both temperatures, with a shift in the ratio of larger molecules to smaller molecules with increasing extraction temperature and with the highest conversion of Point of Ayr coal among these three solvents at both temperatures. Solvent adducts were detected in the tetralin and quinoline extracts by probe mass spectrometry; solvent products were formed from NMP at both temperatures.

  4. Conservation of the response regulator gene gacA in Pseudomonas species

    NARCIS (Netherlands)

    Souza, J.T.; Mazzola, M.; Raaijmakers, J.M.

    2003-01-01

    The response regulator gene gacA influences the production of several secondary metabolites in both pathogenic and beneficial Pseudomonas spp. In this study, we developed primers and a probe for the gacA gene of Pseudomonas species and sequenced a 425 bp fragment of gacA from ten Pseudomonas strains

  5. Immobilization of Pseudomonas fluorescens lipase onto magnetic nanoparticles for resolution of 2-octanol.

    Science.gov (United States)

    Xun, Er-na; Lv, Xiao-li; Kang, Wei; Wang, Jia-xin; Zhang, Hong; Wang, Lei; Wang, Zhi

    2012-10-01

    The lipase from Pseudomonas fluorescens (Lipase AK, AKL) was immobilized onto the magnetic Fe(3)O(4) nanoparticles via hydrophobic interaction. Enzyme loading and immobilization yield were determined as 21.4±0.5 mg/g and 49.2±1.8 %, respectively. The immobilized AKL was successfully used for resolution of 2-octanol with vinyl acetate used as acyl donor. Effects of organic solvent, water activity, substrate ratio, and temperature were investigated. Under the optimum conditions, the preferred isomer for AKL is the (R)-2-octanol and the highest enantioselectivity (E=71.5±2.2) was obtained with a higher enzyme activity (0.197±0.01 μmol/mg/min). The results also showed that the immobilized lipase could be easily separated from reaction media by the magnetic steel and remained 89 % of its initial activity as well as the nearly unchanged enantioselectivity after five consecutive cycles, indicating a high stability in practical operation.

  6. Distribution, diversity, and activity of antibiotic-producing Pseudomonas spp.

    NARCIS (Netherlands)

    Souza, de J.T.

    2002-01-01

    Bacteria of the genus Pseudomonas are potential biocontrol agents of plant diseases caused by various fungi and oomycetes. Antibiotic production is an important trait responsible for the activity of several Pseudomonas

  7. The Solvent Selection framework: solvents for organic synthesis, separation processes and ionic-organic synthesis

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Sansonetti, Sascha; Abildskov, Jens

    2012-01-01

    This paper presents a systematic integrated framework for solvent selection and solvent design. The framework is divided into several modules, which can tackle specific problems in various solvent-based applications. In particular, three modules corresponding to the following solvent selection pr...

  8. Solvent effects in the synergistic solvent extraction of Co2+

    International Nuclear Information System (INIS)

    Kandil, A.T.; Ramadan, A.

    1979-01-01

    The extraction of Co 2+ from a 0.1M ionic strength aqueous phase (Na + , CH 3 COOH) of pH = 5.1 was studied using thenoyltrifluoroacetone, HTTA, in eight different solvents and HTTA + trioctylphosphine oxide, TOPO, in the same solvents. A comparison of the effect of solvent dielectric constant on the equilibrium constant shows a synergism as a result of the increased hydrophobic character imparted to the metal complex due to the formation of the TOPO adduct. (author)

  9. Reclassification of Serpens flexibilis Hespell 1977 as Pseudomonas flexibilis comb. nov., with Pseudomonas tuomuerensis Xin et al. 2009 as a later heterotypic synonym.

    Science.gov (United States)

    Shin, Su-Kyoung; Hwang, Chung Yeon; Cho, Yong-Joon; Yi, Hana

    2015-12-01

    Serpens flexibilis was proposed in 1977 and approved in 1980 without the 16S rRNA gene sequence information. The sequence of S. flexibilis became available in 2010, after the publication of Pseudomonas tuomuerensis in 2009. Our preliminary phylogenetic analyses indicated that these two strains share high sequence similarity and therefore showed strong potential to be united into a single species. To clarify the taxonomic status of the two species, a polyphasic taxonomy study was conducted including whole genome sequencing. The value of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the genome sequences of S. flexibilis ATCC 29606(T) and P. tuomuerensis JCM 14085(T) were 98.1% and 89.0%, respectively. The phenotypic and chemotaxonomic properties including enzymatic activities, substrate utilization profiles, and fatty acids, supported that the two taxa have no pronounced difference and should thus constitute a single species. Therefore, we propose to transfer Serpens flexibilis Hespell 1977 to the genus Pseudomonas as Pseudomonas flexibilis comb. nov. (type strain=ATCC 29606(T)), with Pseudomonas tuomuerensis Xin et al. 2009 as a later heterotypic synonym of Pseudomonas flexibilis. Copyright © 2015 Elsevier GmbH. All rights reserved.

  10. 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. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. SOLVENT FIRE BY-PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D; Samuel Fink, S

    2006-05-22

    Southwest Research Institute (SwRI) conducted a burn test of the Caustic-Side Solvent Extraction (CSSX) solvent to determine the combustion products. The testing showed hydrogen fluoride gas is not a combustion product from a solvent fire when up to 70% of the solvent is consumed. The absence of HF in the combustion gases may reflect concentration of the modifier containing the fluoride groups in the unburned portion. SwRI reported results for other gases (CO, HCN, NOx, formaldehyde, and hydrocarbons). The results, with other supporting information, can be used for evaluating the consequences of a facility fire involving the CSSX solvent inventory.

  12. An overview of industrial solvent use or is there life after chlorinated solvents?

    International Nuclear Information System (INIS)

    Green, B.

    1991-01-01

    Everyone using industrial chemicals has been affected by the fire- storm of new regulations governing solvent use. How will companies currently using hazardous solvents prepare for the changes ahead? What will the impact be on commonly used industrial solvents? What effect are environmental pressures having on solvent use and disposal? Are the responsible individuals in your company up-to-date on phase-out schedules? This paper is written for an audience of compliance coordinators, consultants, production engineers and corporate management. In it, the either addresses the above questions and discusses the specific products affected. The author reviews currently available alternatives to chlorinated and hazardous solvents and introduces a simple system for rating alternatives. The program also includes a discussion of solvent minimization programs and worker reeducation

  13. Isolation and characterization of a new Pseudomonas-related strain ...

    African Journals Online (AJOL)

    % with Pseudomonas putida ()AB680847). The phylogenetic tree formed by 16S rDNA sequences from both strain SKDP-1 and its most related bacteria also proved strain SKDP-1 to be one member of the genus Pseudomonas. Strain SKDP-1 ...

  14. 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

  15. Genetic engineering of Pseudomonas putida KT2440 for rapid and high-yield production of vanillin from ferulic acid.

    Science.gov (United States)

    Graf, Nadja; Altenbuchner, Josef

    2014-01-01

    Vanillin is one of the most important flavoring agents used today. That is why many efforts have been made on biotechnological production from natural abundant substrates. In this work, the nonpathogenic Pseudomonas putida strain KT2440 was genetically optimized to convert ferulic acid to vanillin. Deletion of the vanillin dehydrogenase gene (vdh) was not sufficient to prevent vanillin degradation. Additional inactivation of a molybdate transporter, identified by transposon mutagenesis, led to a strain incapable to grow on vanillin as sole carbon source. The bioconversion was optimized by enhanced chromosomal expression of the structural genes for feruloyl-CoA synthetase (fcs) and enoyl-CoA hydratase/aldolase (ech) by introduction of the strong tac promoter system. Further genetic engineering led to high initial conversion rates and molar vanillin yields up to 86% within just 3 h accompanied with very low by-product levels. To our knowledge, this represents the highest productivity and molar vanillin yield gained with a Pseudomonas strain so far. Together with its high tolerance for ferulic acid, the developed, plasmid-free P. putida strain represents a promising candidate for the biotechnological production of vanillin.

  16. Supercritical Carbon Dioxide and Its Potential as a Life-Sustaining Solvent in a Planetary Environment

    Directory of Open Access Journals (Sweden)

    Nediljko Budisa

    2014-08-01

    Full Text Available Supercritical fluids have different properties compared to regular fluids and could play a role as life-sustaining solvents on other worlds. Even on Earth, some bacterial species have been shown to be tolerant to supercritical fluids. The special properties of supercritical fluids, which include various types of selectivities (e.g., stereo-, regio-, and chemo-selectivity have recently been recognized in biotechnology and used to catalyze reactions that do not occur in water. One suitable example is enzymes when they are exposed to supercritical fluids such as supercritical carbon dioxide: enzymes become even more stable, because they are conformationally rigid in the dehydrated state. Furthermore, enzymes in anhydrous organic solvents exhibit a “molecular memory”, i.e., the capacity to “remember” a conformational or pH state from being exposed to a previous solvent. Planetary environments with supercritical fluids, particularly supercritical carbon dioxide, exist, even on Earth (below the ocean floor, on Venus, and likely on Super-Earth type exoplanets. These planetary environments may present a possible habitat for exotic life.

  17. Characterization of Pseudomonas pathovars isolated from rosaceous fruit trees in East Algeria.

    Science.gov (United States)

    Harzallah, D; Sadallah, S; Larous, L

    2004-01-01

    A survey of bacterial diseases due to Pseudomonas on rosaceous fruit trees was conducted. In forty two orchards located in the Constantine region ( East Algeria). Pseudomonas isolates were identified on the bases of their cultural and biochemical characteristics . A total of fifty nine phytopathogenic bacteria were isolated from diseased pome and stone fruit trees. Thirty one strains comparable to Pseudomonas syringae pv. syringae were isolated from cherry (Prunus avium L.), plum (P. domestica L.), apricot (P. armeniaca L.), almond (P. dulcis L.) and pear trees (Pirus communis L.); sixteen strains comparable to Pseudomonas syringae pv. morsprunorum were obtained from samples of cherry and plum. Twelve strains of Pseudomonas viridiflava were isolated from cherry, apricot and peach (Prunus persica L.).

  18. Solvent - solute interaction

    International Nuclear Information System (INIS)

    Urbanczyk, A.; Kalinowski, M.K.

    1983-01-01

    The electronic absorption spectrum of vanadyl acetylacetonate has been studied in 15 organic solvents. It has been found that wavenumbers and molar absorptivities of the long-wavelength bands (d-d transitions) can be well described by a complementary Lewis acid-base model including Gutmann's donor number [Gutmann V., Wychera E., Inorg. Nucl. Chem. Letters 2, 257 (1966)] and acceptor number [Mayer U., Gutmann V., Gerger W., Monatsh. Chem. 106, 1235 (1975)] of a solvent. This model describes also the solvent effect of the hyperfine splitting constant, Asub(iso)( 51 V), from e.s.r. spectra of VOacac 2 . These observations are discussed in terms of the donor-acceptor concept for solvent-solute interactions. (Author)

  19. Bioleaching of Gold and Silver from Waste Printed Circuit Boards by Pseudomonas balearica SAE1 Isolated from an e-Waste Recycling Facility.

    Science.gov (United States)

    Kumar, Anil; Saini, Harvinder Singh; Kumar, Sudhir

    2018-02-01

    Indigenous bacterial strain Pseudomonas balearica SAE1, tolerant to e-waste toxicity was isolated from an e-waste recycling facility Exigo Recycling Pvt. Ltd., India. Toxicity tolerance of bacterial strain was analyzed using crushed (particle size ≤150 µm) waste computer printed circuit boards (PCBs)/liter (L) of culture medium. The EC 50 value for SAE1 was 325.7 g/L of the e-waste pulp density. Two-step bioleaching was then applied to achieve the dissolution of gold (Au) and silver (Ag) from the e-waste. To maximize precious metal dissolution, factors including pulp density, glycine concentration, pH level, and temperature were optimized. The optimization resulted in 68.5 and 33.8% of Au and Ag dissolution, respectively, at a pH of 9.0, a pulp density of 10 g/L, a temperature of 30 °C, and a glycine concentration of 5 g/L. This is the first study of Au and Ag bioleaching using indigenous e-waste bacteria and its analysis to determine e-waste toxicity tolerance.

  20. Deasphalting solvents

    International Nuclear Information System (INIS)

    Carrillo, J. A; Caceres, J; Vela, G; Bueno, H

    1996-01-01

    This paper describes how the deasphalted oil (DMO) or demetalized oil (DMO) quality (CCR, Ni, V end asphaltenes contents) changes with: DAO or DMO yield, solvent/feed ratio, type of vacuum reside (from paraffinic to blends with vis breaking bottoms), extraction temperature and extraction solvent (propane, propylene, n-butane and I butane)

  1. Energetics of binary mixed culture of Pseudomonas aeruginosa and ...

    African Journals Online (AJOL)

    Bioenergetic analysis of the growth of the binary mixed culture (Pseudomonas aeruginosa and Pseudomonas fluorescence) on phenol chemostat culture was carried out. The data were checked for consistency using carbon and available electron balances. When more than the minimum number of variables are measured, ...

  2. Solvent cleaning system and method for removing contaminants from solvent used in resin recycling

    Science.gov (United States)

    Bohnert, George W [Harrisonville, MO; Hand, Thomas E [Lee's Summit, MO; DeLaurentiis, Gary M [Jamestown, CA

    2009-01-06

    A two step solvent and carbon dioxide based system that produces essentially contaminant-free synthetic resin material and which further includes a solvent cleaning system for periodically removing the contaminants from the solvent so that the solvent can be reused and the contaminants can be collected and safely discarded in an environmentally safe manner.

  3. Presence of VIM-Positive Pseudomonas Species in Chickens and Their Surrounding Environment.

    Science.gov (United States)

    Zhang, Rongmin; Liu, Zhihai; Li, Jiyun; Lei, Lei; Yin, Wenjuan; Li, Mei; Wu, Congming; Walsh, Timothy R; Wang, Yang; Wang, Shaolin; Wu, Yongning

    2017-07-01

    Metallo-β-lactamase gene bla VIM was identified on the chromosome of four Pseudomonas sp. isolates from a chicken farm, including one Pseudomonas aeruginosa isolate from a swallow ( Yanornis martini ), one Pseudomonas putida isolate from a fly, and two P. putida isolates from chickens. The four isolates shared two variants of bla VIM -carrying genomic contexts that resemble the corresponding regions of clinical metallo-β-lactamase-producing Pseudomonas spp. Our study suggests that the surveillance of carbapenemase-producing bacteria in livestock and their surrounding environment is urgently needed. Copyright © 2017 American Society for Microbiology.

  4. Staphylococcus aureus Alters Growth Activity, Autolysis, and Antibiotic Tolerance in a Human Host-Adapted Pseudomonas aeruginosa Lineage

    DEFF Research Database (Denmark)

    Frydenlund Michelsen, Charlotte; Christensen, Anne-Mette; Bojer, Martin Saxtorph

    2014-01-01

    Interactions among members of polymicrobial infections or between pathogens and the commensal flora may determine disease outcomes. Pseudomonas aeruginosa and Staphylococcus aureus are important opportunistic human pathogens and are both part of the polymicrobial infection communities in human...... hosts. In this study, we analyzed the in vitro interaction between S. aureus and a collection of P. aeruginosa isolates representing different evolutionary steps of a dominant lineage, DK2, that have evolved through decades of growth in chronically infected patients. While the early adapted P....... aeruginosa DK2 strains outcompeted S. aureus during coculture on agar plates, we found that later P. aeruginosa DK2 strains showed a commensal-like interaction, where S. aureus was not inhibited by P. aeruginosa and the growth activity of P. aeruginosa was enhanced in the presence of S. aureus. This effect...

  5. Porous fiber formation in polymer-solvent system undergoing solvent evaporation

    Science.gov (United States)

    Dayal, Pratyush; Kyu, Thein

    2006-08-01

    Temporal evolution of the fiber morphology during dry spinning has been investigated in the framework of Cahn-Hilliard equation [J. Chem. Phys. 28, 258 (1958)] pertaining to the concentration order parameter or volume fraction given by the Flory-Huggins free energy of mixing [P. J. Flory, Principles of Polymer Chemistry (Cornell University Press, Ithaca, NY, 1953), p. 672] in conjunction with the solvent evaporation rate. To guide the solvent evaporation induced phase separation, equilibrium phase diagram of the starting polymer solution was established on the basis of the Flory-Huggins free energy of mixing. The quasi-steady-state approximation has been adopted to account for the nonconserved nature of the concentration field caused by the solvent loss. The process of solvent evaporation across the fiber skin-air interface was treated in accordance with the classical Fick's law [R. B. Bird et al., Transport Phenomena (J. Wiley, New York, 1960), p. 780]. The simulated morphologies include gradient type, hollow fiber type, bicontinuous type, and host-guest type. The development of these diverse fiber morphologies is explicable in terms of the phase diagram of the polymer solution in a manner dependent on the competition between the phase separation dynamics and rate of solvent evaporation.

  6. Essential roles of protein-solvent many-body correlation in solvent-entropy effect on protein folding and denaturation: Comparison between hard-sphere solvent and water

    International Nuclear Information System (INIS)

    Oshima, Hiraku; Kinoshita, Masahiro

    2015-01-01

    In earlier works, we showed that the entropic effect originating from the translational displacement of water molecules plays the pivotal role in protein folding and denaturation. The two different solvent models, hard-sphere solvent and model water, were employed in theoretical methods wherein the entropic effect was treated as an essential factor. However, there were similarities and differences in the results obtained from the two solvent models. In the present work, to unveil the physical origins of the similarities and differences, we simultaneously consider structural transition, cold denaturation, and pressure denaturation for the same protein by employing the two solvent models and considering three different thermodynamic states for each solvent model. The solvent-entropy change upon protein folding/unfolding is decomposed into the protein-solvent pair (PA) and many-body (MB) correlation components using the integral equation theories. Each component is further decomposed into the excluded-volume (EV) and solvent-accessible surface (SAS) terms by applying the morphometric approach. The four physically insightful constituents, (PA, EV), (PA, SAS), (MB, EV), and (MB, SAS), are thus obtained. Moreover, (MB, SAS) is discussed by dividing it into two factors. This all-inclusive investigation leads to the following results: (1) the protein-water many-body correlation always plays critical roles in a variety of folding/unfolding processes; (2) the hard-sphere solvent model fails when it does not correctly reproduce the protein-water many-body correlation; (3) the hard-sphere solvent model becomes problematic when the dependence of the many-body correlation on the solvent number density and temperature is essential: it is not quite suited to studies on cold and pressure denaturating of a protein; (4) when the temperature and solvent number density are limited to the ambient values, the hard-sphere solvent model is usually successful; and (5) even at the ambient

  7. Restoring solvent for nuclear separation processes

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    Solvent extraction separation processes are used to recover usable nuclear materials from spent fuels. These processes involve the use of an extractant/diluent (solvent) for separation of the reusable actinides from unwanted fission products. The most widely used processes employ tributyl phosphate as an extractant diluted with a normal-paraffin hydrocarbon. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. In most processes, the solvent is recycled after cleaning. Solvent cleaning generally involves scrubbing with a sodium carbonate solution. Studies at the Savannah River Laboratory have shown that carbonate washing, although removing residual solvent activity, does not remove more solvent-soluble binding ligands (formed by solvent degradation), which hold fission products in the solvent. Treatment of the solvent with a solid adsorbent after carbonate washing removes binding ligands and significantly improves recycled solvent performance. Laboratory work to establish the advantage of adsorbent cleaning and the development of a full-scale adsorption process is described. The application of this process for cleaning the first cycle solvent of a Savannah River Plant production process is discussed

  8. Soil mixture composition alters Arabidopsis susceptibility to Pseudomonas syringae infection

    Science.gov (United States)

    Pseudomonas syringae is a Gram-negative bacterial pathogen that causes disease on more than 100 different plant species, including the model plant Arabidopsis thaliana. Dissection of the Arabidopsis thaliana-Pseudomonas syringae pathosystem has identified many factors that contribute to successful ...

  9. Selective solvent extraction of oils

    Energy Technology Data Exchange (ETDEWEB)

    1938-04-09

    In the selective solvent extraction of naphthenic base oils, the solvent used consists of the extract obtained by treating a paraffinic base oil with a selective solvent. The extract, or partially spent solvent is less selective than the solvent itself. Selective solvents specified for the extraction of the paraffinic base oil are phenol, sulphur dioxide, cresylic acid, nitrobenzene, B:B/sup 1/-dichlorethyl ether, furfural, nitroaniline and benzaldehyde. Oils treated are Coastal lubricating oils, or naphthenic oils from the cracking, or destructive hydrogenation of coal, tar, lignite, peat, shale, bitumen, or petroleum. The extraction may be effected by a batch or counter-current method, and in the presence of (1) liquefied propane, or butane, or naphtha, or (2) agents which modify the solvent power such as, water, ammonia, acetonitrile, glycerine, glycol, caustic soda or potash. Treatment (2) may form a post-treatment effected on the extract phase. In counter-current treatment in a tower some pure selective solvent may be introduced near the raffinate outlet to wash out any extract therefrom.

  10. ANTAGONISTIC POTENTIAL OF FLUORESCENT Pseudomonas ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    GROWTH OF TOMATO CHALLENGED WITH PHTOPATHOGENS ... This study focused on the antagonistic potential of fluorescent Pseudomonas in vitro, and its inoculation effect on growth .... the 5 days old culture in starch agar with Lugol's.

  11. Switchable polarity solvent for liquid phase microextraction of Cd(II) as pyrrolidinedithiocarbamate chelates from environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Erkan, E-mail: kimyager_erkan@hotmail.com; Soylak, Mustafa, E-mail: soylak@erciyes.edu.tr

    2015-07-30

    A switchable polarity solvent was synthesized from triethylamine (TEA)/water/CO{sub 2} (Dry ice) via proton transfer reaction has been used for the microextraction of cadmium(II) as pyrrolidinedithiocarbamate (APDC) chelate. Cd(II)-APDC chelate was extracted into the switchable polarity solvent drops by adding 2 mL 10 M sodium hydroxide solution. Analytical parameters affecting the complex formation and microextraction efficiency such as pH, amount of ligand, volume of switchable polarity solvent and NaOH, sample volume were optimized. The effects of foreign ions were found tolerably. Under optimum conditions, the detection limit was 0.16 μg L{sup −1} (3Sb/m, n = 7) and the relative standard deviation was 5.4% (n = 7). The method was validated by the analysis of certified reference materials (TMDA-51.3 fortified water, TMDA-53.3 fortified water and SPS-WW2 waste water, 1573a Tomato Leaves and Oriental Basma Tobacco Leaves (INCT-OBTL-5)) and addition/recovery tests. The method was successfully applied to determination of cadmium contents of water, vegetable, fruit and cigarette samples. - Highlights: • Switchable polarity solvent was synthesized from triethylamine (TEA)/water/CO{sub 2}. • The switchable polarity solvent has been used for the microextraction of cadmium(II). • The important factors were optimized. • The method was applied to determination of cadmium in real samples.

  12. Biotransformation of citrinin to decarboxycitrinin using an organic solvent-tolerant marine bacterium, Moraxella sp. (MB1)

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi; Naik, C.G.; Rodrigues, C.

    and Bhosle, 2003), are reported to grow in media containing various amounts of organic solvents (cyclohexane, p-xylene, 1-octanol, toluene, 1-heptanol, benzene etc.). These bacteria have mechanisms available to cope with the deleterious effects..., when compared to their chemical counterparts, offer the advantages of high selectivity and mild operating conditions. For example esterases are being increasingly recognized as useful for stereospecific manipulation of esters (Cornec et al., 1998...

  13. Solvent substitutes

    International Nuclear Information System (INIS)

    Evanoff, S.P.

    1995-01-01

    The environmental and industrial hygiene regulations promulgated since 1980, most notably the Superfund Amendments and Reauthorization Act (SARA), the Hazardous and Solid Waste Amendments to the Resources Conservation and Recovery Act (RCRA), and the Clean Air Act Amendments of 1990, have brought about an increased emphasis on user exposure, hazardous waste generation, and air emissions. As a result, industry is performing a fundamental reassessment of cleaning solvents, processes, and procedures. The more progressive organizations have made their goal the elimination of solvents that may pose significant potential human health and environmental hazards. This chapter discusses solvent cleaning in metal-finishing, metal-manufacturing, and industrial maintenance applications; precision cleaning; and electronics manufacturing. Nonmetallic cleaning, adhesives, coatings, inks, and aerosols also will be addressed, but in a more cursory manner

  14. Interaction of antibacterial compounds with RND efflux pumps in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Juerg eDreier

    2015-07-01

    Full Text Available Pseudomonas aeruginosa infections are becoming increasingly difficult to treat due to intrinsic antibiotic resistance and the propensity of this pathogen to accumulate diverse resistance mechanisms. Hyperexpression of efflux pumps of the Resistance-Nodulation-Division-type multidrug efflux pumps (e.g. MexAB-OprM, chromosomally encoded by mexAB-oprM, mexCD-oprJ, mexEF-oprN, and mexXY (-oprA is often detected in clinical isolates and contributes to worrying multi-drug resistance phenotypes.Not all antibiotics are affected to the same extent by the aforementioned RND efflux pumps. The impact of efflux on antibiotic activity varies not only between different classes of antibiotics but also between members of the same family of antibiotics. Subtle differences in physicochemical features of compound-pump and compound-solvent interactions largely determine how compounds are affected by efflux activity.The combination of different high-resolution techniques helps to gain insight into the functioning of these molecular machineries. This review discusses substrate recognition patterns based on experimental evidence and computer simulations with a focus on MexB, the pump subunit of the main RND transporter in P. aeruginosa.

  15. 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...

  16. Antimicrobial resistance of Pseudomonas spp. isolated from wastewater and wastewater-impacted marine coastal zone.

    Science.gov (United States)

    Luczkiewicz, Aneta; Kotlarska, Ewa; Artichowicz, Wojciech; Tarasewicz, Katarzyna; Fudala-Ksiazek, Sylwia

    2015-12-01

    In this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins, as well as their combination with the β-lactamase inhibitors, monobactams, fluoroquinolones, and polymyxins. Among identified species, resistance to all antimicrobials but colistin was shown by Pseudomonas putida, the predominant species in all sampling points. In other species, resistance was observed mainly against ceftazidime, ticarcillin, ticarcillin-clavulanate, and aztreonam, although some isolates of Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas pseudoalcaligenes, and Pseudomonas protegens showed multidrug-resistance (MDR) phenotype. Among P. putida, resistance to β-lactams and to fluoroquinolones as well as multidrug resistance become more prevalent after wastewater treatment, but the resistance rate decreased in marine water samples. Obtained data, however, suggests that Pseudomonas spp. are equipped or are able to acquire a wide range of antibiotic resistance mechanisms, and thus should be monitored as possible source of resistance genes.

  17. Canyon solvent cleaning with solid adsorbents

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    The HM Process at the Savannah River Plant (SRP) uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials that influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands that hold fission products in the solvent. Treatment of solvent with a solid adsorbent removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale adsorption process and the use of the process to clean HM Process first cycle solvent are presented

  18. Radionuclide and heavy metal biosorption by Pseudomonas biomass

    International Nuclear Information System (INIS)

    Sar, Pinaki; D'Souza, S.F.; Kazy, Sufia K.; Singh, S.P.

    2001-01-01

    Biosorptive metal (nickel and copper) and radionuclide (uranium) uptake capacity of two Pseudomonas strains was investigated in order to develop biotechnological strategies for toxic metals remediation. Lyophilized Pseudomonas biomass showed a very high uranium loading of 541 mg g -1 dry wt. Compared to this, the other bacterial strain of Pseudomonas aeruginosa used for nickel and copper removal yielded a maximum value of 265 mg g -1 and 137 mg g -1 respectively. Cation binding by both the biomass was fast saturating, pH -dependent process with optimum pH for U, Cu and Ni was pH 5.0, 7.0 and 8.0, respectively. In bimetallic combination, U sorption was inhibited only by Fe 3+ , Al 3+ and Cu 2+ suggesting a selective cation binding by the Pseudomonas biomass. In case of Ni and Cu, presence of Na, K or Ca increased the metal binding while Cd and Pb was antagonistic. Mineral acids could recover more than 75% (on average) of sorbed Ni or Cu. Noticeably, uranium and copper desorption was specifically high (88-90%) with sodium carbonate while calcium carbonate showed a good result for nickel. The overall data are in favour of deployment of the test biomass as efficient metal/radionuclide removal/recovery system. (author)

  19. Next Generation Solvent Performance in the Modular Caustic Side Solvent Extraction Process - 15495

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Tara E. [Savannah River Remediation, LLC., Aiken, SC (United States); Scherman, Carl [Savannah River Remediation, LLC., Aiken, SC (United States); Martin, David [Savannah River Remediation, LLC., Aiken, SC (United States); Suggs, Patricia [Savannah River Site (SRS), Aiken, SC (United States)

    2015-01-14

    Changes to the Modular Caustic Side Solvent Extraction Unit (MCU) flow-sheet were implemented in the facility. Implementation included changing the scrub and strip chemicals and concentrations, modifying the O/A ratios for the strip, scrub, and extraction contactor banks, and blending the current BoBCalixC6 extractant-based solvent in MCU with clean MaxCalix extractant-based solvent. During the successful demonstration period, the MCU process was subject to rigorous oversight to ensure hydraulic stability and chemical/radionuclide analysis of the key process tanks (caustic wash tank, solvent hold tank, strip effluent hold tank, and decontaminated salt solution hold tank) to evaluate solvent carryover to downstream facilities and the effectiveness of cesium removal from the liquid salt waste. Results indicated the extraction of cesium was significantly more effective with an average Decontamination Factor (DF) of 1,129 (range was 107 to 1,824) and that stripping was effective. The contactor hydraulic performance was stable and satisfactory, as indicated by contactor vibration, contactor rotational speed, and flow stability; all of which remained at or near target values. Furthermore, the Solvent Hold Tank (SHT) level and specific gravity was as expected, indicating that solvent integrity and organic hydraulic stability were maintained. The coalescer performances were in the range of processing results under the BOBCalixC6 flow sheet, indicating negligible adverse impact of NGS deployment. After the Demonstration period, MCU began processing via routine operations. Results to date reiterate the enhanced cesium extraction and stripping capability of the Next Generation Solvent (NGS) flow sheet. This paper presents process performance results of the NGS Demonstration and continued operations of MCU utilizing the blended BobCalixC6-MaxCalix solvent under the NGS flowsheet.

  20. 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.

  1. Purex process solvent: literature review

    International Nuclear Information System (INIS)

    Geier, R.G.

    1979-10-01

    This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables

  2. Purex process solvent: literature review

    Energy Technology Data Exchange (ETDEWEB)

    Geier, R.G.

    1979-10-01

    This document summarizes the data on Purex process solvent presently published in a variety of sources. Extracts from these various sources are presented herein and contain the work done, the salient results obtained, and the original, unaltered conclusions of the author of each paper. Three major areas are addressed: solvent stability, solvent quality testing, and solvent treatment processes. 34 references, 44 tables.

  3. Interactions between biosurfactant-producing Pseudomonas and Phytophthora species

    OpenAIRE

    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 pepper in Vietnam and promote root and shoot development of the ‘King of Spices’. Biosurfactant-producing P. fluorescens strain SS101 was also effective in controlling tomato late blight caused by P...

  4. Interleukin-18 impairs the pulmonary host response to Pseudomonas aeruginosa

    NARCIS (Netherlands)

    Schultz, Marc J.; Knapp, Sylvia; Florquin, Sandrine; Pater, Jennie; Takeda, Kiyoshi; Akira, Shizuo; van der Poll, Tom

    2003-01-01

    Interleukin-18 (IL-18) is a potent cytokine with many different proinflammatory activities. To study the role of IL-18 in the pathogenesis of Pseudomonas pneumonia, IL-18-deficient (IL-18(-/-)) and wild-type mice were intranasally inoculated with Pseudomonas aeruginosa. IL-18 deficiency was

  5. Cemaran Staphylococcus aureus dan Pseudomonas aerogenosa Pada Stetoskop dirumah Sakit

    Directory of Open Access Journals (Sweden)

    leka lutpiatina

    2017-10-01

    The result of the research was found contamination of Staphylococcus aureus and Pseudomonas aerogenosa on steteskop. The site home condition of the research data was 66.7% cleaned daily, the storage method was placed on the table 70% and the duration of using the set home more than 1 year as much as 70%. The conclusion of stethoscope at Banjarbaru Hospital was contaminated with Staphylococcus aureus by 70% and Pseudomonas aerogenosa by 17%. The suggestion of research can be continued by knowing the existence of Staphylococcus aureus resistant antibiotic and Pseudomonas aerogenous antibiotic resistant at steteskop at Hospital.

  6. Accuracy Profiles for Analyzing Residual Solvents in Textiles by GC-MS.

    Science.gov (United States)

    Bao, Qibei; Fu, Kejie; Ren, Qingqing; Zhong, Yingying; Qian, Dan

    2017-10-01

    Excess residual solvents (RSs) in clothes or other textiles could be toxic and pose risks to both humans and the environment. N,N-Dimethylformamide (DMF), N,N-dimethylacetamide (DMAc) and 1-methyl-2-pyrrolidinone (NMP) are important chemicals frequently used as solvents in the textile industry. Several organizations have proposed limiting DMF, DMAc and NMP in textiles, but an appropriate detection method has not been proposed. A sensitive GC-MS method for the quantification of DMF, DMAc and NMP in textiles was developed. After extraction with ethyl acetate, these RSs were separated on a DB-5MS capillary column. The oven temperature was increased from 50°C (held for 0.5 min) at 10°C/min to 120°C (held for 1 min). The method was fully validated according to the accuracy profile procedure, which is based on β-expectation tolerance intervals for the total measurement bias. Linearity was observed in the range of 0.5-10 mg/L for the solvents with limit of quantification values of 4.2, 3.5 and 2.5 mg/kg for DMF, DMAc and NMP, respectively. The repeatability and intermediate precision were NMP. The recoveries of DMF, DMAc and NMP were 91.2-106.3%, 89.5-97.7% and 85.6-101.3%, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Solvent/non-solvent sintering: a novel route to create porous microsphere scaffolds for tissue regeneration.

    Science.gov (United States)

    Brown, Justin L; Nair, Lakshmi S; Laurencin, Cato T

    2008-08-01

    Solvent/non-solvent sintering creates porous polymeric microsphere scaffolds suitable for tissue engineering purposes with control over the resulting porosity, average pore diameter, and mechanical properties. Five different biodegradable biocompatible polyphosphazenes exhibiting glass transition temperatures from -8 to 41 degrees C and poly (lactide-co-glycolide), (PLAGA) a degradable polymer used in a number of biomedical settings, were examined to study the versatility of the process and benchmark the process to heat sintering. Parameters such as: solvent/non-solvent sintering solution composition and submersion time effect the sintering process. PLAGA microsphere scaffolds fabricated with solvent/non-solvent sintering exhibited an interconnected porosity and pore size of 31.9% and 179.1 mum, respectively which was analogous to that of conventional heat sintered PLAGA microsphere scaffolds. Biodegradable polyphosphazene microsphere scaffolds exhibited a maximum interconnected porosity of 37.6% and a maximum compressive modulus of 94.3 MPa. Solvent/non-solvent sintering is an effective strategy for sintering polymeric microspheres, with a broad spectrum of glass transition temperatures, under ambient conditions making it an excellent fabrication route for developing tissue engineering scaffolds and drug delivery vehicles. (c) 2007 Wiley Periodicals, Inc.

  8. Measurement and correlation of solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures

    International Nuclear Information System (INIS)

    Wang, Jinxiu; Xie, Chuang; Yin, Qiuxiang; Tao, Linggang; Lv, Jun; Wang, Yongli; He, Fang; Hao, Hongxun

    2016-01-01

    Highlights: • Solubility of cefmenoxime hydrochloride in pure and binary solvents was determined. • The experimental solubility data were correlated by thermodynamic models. • A model was employed to calculate the melting temperature of cefmenoxime hydrochloride. • Mixing thermodynamic properties of cefmenoxime hydrochloride were calculated. - Abstract: The solubility of cefmenoxime hydrochloride in pure solvents and binary solvent mixtures was measured at temperatures from (283.15 to 313.15) K by using the UV spectroscopic method. The results reveal that the solubility of cefmenoxime hydrochloride increases with increasing temperature in all solvent selected. The solubility of cefmenoxime hydrochloride reaches its maximum value when the mole fraction of isopropanol is 0.2 in the binary solvent mixtures of (isopropanol + water). The modified Apelblat equation and the NRTL model were successfully used to correlate the experimental solubility in pure solvents while the modified Apelblat equation, the CNIBS/R–K model and the Jouyban–Acree model were applied to correlate the solubility in binary solvent mixtures. In addition, the mixing thermodynamic properties of cefmenoxime hydrochloride in different solvents were also calculated based on the NRTL model and experimental solubility data.

  9. Measurement and prediction of dabigatran etexilate mesylate Form II solubility in mono-solvents and mixed solvents

    International Nuclear Information System (INIS)

    Xiao, Yan; Wang, Jingkang; Wang, Ting; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun; Bao, Ying; Fang, Wen; Yin, Qiuxiang

    2016-01-01

    Highlights: • Solubility of DEM Form II in mono-solvents and binary solvent mixtures was measured. • Regressed UNIFAC model was used to predict the solubility in solvent mixtures. • The experimental solubility data were correlated by different models. - Abstract: UV spectrometer method was used to measure the solubility data of dabigatran etexilate mesylate (DEM) Form II in five mono-solvents (methanol, ethanol, ethane-1,2-diol, DMF, DMAC) and binary solvent mixtures of methanol and ethanol in the temperature range from 287.37 K to 323.39 K. The experimental solubility data in mono-solvents were correlated with modified Apelblat equation, van’t Hoff equation and λh equation. GSM model and Modified Jouyban-Acree model were employed to correlate the solubility data in mixed solvent systems. And Regressed UNIFAC model was used to predict the solubility of DEM Form II in the binary solvent mixtures. Results showed that the predicted data were consistent with the experimental data.

  10. Antimicrobial properties of Pseudomonas strains producing the antibiotic mupirocin.

    Science.gov (United States)

    Matthijs, Sandra; Vander Wauven, Corinne; Cornu, Bertrand; Ye, Lumeng; Cornelis, Pierre; Thomas, Christopher M; Ongena, Marc

    2014-10-01

    Mupirocin is a polyketide antibiotic with broad antibacterial activity. It was isolated and characterized about 40 years ago from Pseudomonas fluorescens NCIMB 10586. To study the phylogenetic distribution of mupirocin producing strains in the genus Pseudomonas a large collection of Pseudomonas strains of worldwide origin, consisting of 117 Pseudomonas type strains and 461 strains isolated from different biological origins, was screened by PCR for the mmpD gene of the mupirocin gene cluster. Five mmpD(+) strains from different geographic and biological origin were identified. They all produced mupirocin and were strongly antagonistic against Staphylococcus aureus. Phylogenetic analysis showed that mupirocin production is limited to a single species. Inactivation of mupirocin production leads to complete loss of in vitro antagonism against S. aureus, except on certain iron-reduced media where the siderophore pyoverdine is responsible for the in vitro antagonism of a mupirocin-negative mutant. In addition to mupirocin some of the strains produced lipopeptides of the massetolide group. These lipopeptides do not play a role in the observed in vitro antagonism of the mupirocin producing strains against S. aureus. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  11. Gentamicin in Pseudomonas aeruginosa

    African Journals Online (AJOL)

    infections by Ps. aeruginosa is contra-indicated. In our study only 2,3 % of the Ps. aeruginosa strains were resistant to gentamicin (MIC 25 Ilg/ml). In view of the synergy reported for combined gentamicin and carbeni- cillin therapy," a combination of these two drugs may be recommended in the treatment of all Pseudomonas.

  12. Ultraviolet-B lethal damage on Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Degiorgi, C.F.; Fernandez, R.O.; Pizarro, R.A.

    1996-01-01

    Pseudomonas aeruginosa has shown an increased sensitivity compared with that of Escherichia coli and Enterobacter cloacae, when they were exposed to 0.4 kJ/m2 of ultraviolet-B radiation. The rapid decay in cell viability observed in Pseudomonas aeruginosa after the irradiation was influenced by factors such as culture media and the presence of pyocyanine during the irradiation. The radioinduced lethal damage could be prevented by photoreactivating treatment, indicating that pyrimidine dimer formation was the mechanism causing bacterial death. The results indicate that several environmental conditions may act as protective agents against ultraviolet-B-induced damage

  13. Antibiotics Susceptibility Pattern of Pseudomonas aeruginosa ...

    African Journals Online (AJOL)

    ABSTRACT: This work investigated the prevalence and antibiotics sensitivity of Pseudomonas aeruginosa isolated from ... skin triggers coagulation and an acute inflammatory response ... agents with anti-pseudomonal activity, life-threatening.

  14. Cesium Concentration in MCU Solvent

    International Nuclear Information System (INIS)

    Walker, D

    2006-01-01

    During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing ∼4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to ∼2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain ∼23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a ∼70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank (containing additional

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

    International Nuclear Information System (INIS)

    Papadopoulou, E.; Papadopoulou, L.; Paraskevopoulos, K.M.; Koidis, P.; Sivropoulou, A.

    2009-01-01

    Bacterial infections frequently lead to hard tissue destructions. The purpose of the present study was to address the question as to how the bacteria destroy hard tissues with the use of an in vitro system. A bacterium was isolated from a solution simulating body fluid which was identified as Pseudomonas A1, and is able to solubilize tricalcium phosphate when it grows in IP broth. The presence of Pseudomonas A1 resulted in dose-dependent inhibition of the formation of hydroxyapatite layer, on the surface of bioglass specimens immersed in SBF solution, in contrast to the control. When the bioglass specimens were immersed in IP broth without Ca 3 (PO 4 ) 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.

  16. Iodine removing method in organic solvent

    International Nuclear Information System (INIS)

    Suzuki, Takeo; Sakurai, Manabu

    1988-01-01

    Purpose: To effectively remove iodine in an organic solvent to thereby remove iodine in the solvent that can be re-used or put to purning treatment. Method: Organic solvent formed from wastes of nuclear facilities is mixed with basic lead acetate, or silica gel or activated carbon incorporated with such a compound to adsorb iodine in the organic solvent to the basic lead acetate. Then, iodine in the organic solvent is removed by separating to eliminate the basic lead acetate adsorbing iodine from the organic solvent or by passing the organic solvent through a tower or column charged or pre-coated with silica gel or activated carbon incorporated with lead acetate. By using basic lead acetate as the adsorbents, iodine can effective by adsorbed and eliminated. Thus, the possibility of circumstantial release of iodine can be reduced upon reusing or burning treatment of the organic solvent. (Kamimura, M.)

  17. Sensibilidade do carrapato Boophilus microplus a solventes Sensibility of Boophilus microplus tick to solvents

    Directory of Open Access Journals (Sweden)

    Ana Carolina de Souza Chagas

    2003-02-01

    Full Text Available Os experimentos envolvendo o uso de acaricidas sintéticos ou naturais, geralmente necessitam da utilização de um solvente. Com a finalidade de verificar a sensibilidade do carrapato bovino Boophilus microplus a diferentes solventes, larvas e fêmeas ingurgitadas deste ectoparasito foram expostas a sete solventes em cinco diferentes concentrações, na ausência e presença de azeite de oliva. Os resultados mostraram que a utilização do azeite de oliva não produz resultados diferentes estatisticamente em testes de larvas com papel impregnado, fato não verificado em testes de imersão de adultos com compostos hidrofílicos. A mortalidade média causada pelos solventes foi menor nos testes com papel impregnado, aumentando nos testes de imersão de larvas e de adultos. Solventes de baixo peso molecular e pouca viscosidade como o álcool metílico e o álcool etílico, não interferiram na mortalidade média em testes biológicos de B. microplus, principalmente em concentrações inferiores a 76%.Experiments carried out with synthetic or natural acaricides usually use a solvent. To investigate the sensitivity of Boophilus microplus cattle tick to different solvents, larvae and engorged female were subjected to seven solvents in five different concentrations. It was done in the presence and absence of olive oil. The results showed that the utilization of olive oil doesn't produce different statistical results in impregnated paper larvae test. It did not happen in adults immersion test with hydrophilic compounds. The mean mortality caused by solvents was small in impregnated paper larvae test, increasing in immersion tests of larvae and adults. Solvents with low molecular weight and viscosity like ethyl alcohol and methyl alcohol did not cause interference in the mortality of B. microplus in biological tests, mainly in concentrations below 76%.

  18. 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. Copyright © 2016. Published by Elsevier Editora Ltda.

  19. [The effect of biyuanshu oral liquid on the formation of Pseudomonas aeruginosa biofilms in vitro].

    Science.gov (United States)

    Liu, Xiang; Chen, Haihong; Wang, Shengqing

    2012-07-01

    To observe the effect of biyuanshu oral liquid on the formation of pseudomonas aeruginosa biofilms in vitro. Pseudomonas aeruginosa biofilm was established by plate culture and detected by Scanning electron microscopy and AgNO3 staining. After treated with different dosages of biyuanshu oral liquid and erythromycin, the pseudomonas aeruginosa biofilms were observed by AgNO3 staining and the number of viable bacteria were measured by serial dilution. The pseudomonas aeruginosa biofilms could be detected by SEM at the seventh culture day and it was consistent with the detection of AgNO3 staining. The biyuanshu oral liquid and erythromycin have the effect on inhibiting the formation of pseudomonas aeruginosa biofilms. But with the already formed pseudomonas aeruginosa biofilms the inhibition was not significant. The serial dilution method showed that the viable counts of bacteria of biyuanshu oral liquid and erythromycin treated groups were significantly lower than those untreated groups (P formation of pseudomonas aeruginosa biofilms in vitro.

  20. Next Generation Solvent Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Birdwell, Joseph F. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Inter laboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  1. Selection and design of solvents

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules....... With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection......) that match the desired functions of a solvent for a specified set of applications. Use of organic chemicals and ionic liquids as solvents will be covered....

  2. The Pseudomonas Quinolone Signal (PQS)

    DEFF Research Database (Denmark)

    Sams, Thomas; Baker, Ysobel; Hodgkinson, James

    2015-01-01

    Pseudomonas aeruginosa is an opportunistichuman pathogen that routinely appears near the top ofpublic health threat lists worldwide. P. aeruginosa causes in-fections by secreting a wealth of exceptionally active exo-products, leading to tissue damage. The synthesis of manyof these virulence factors...

  3. Inhibition of Escherichia coli O157:H7 on stainless steel using Pseudomonas veronii biofilms.

    Science.gov (United States)

    Kim, Y; Kim, H; Beuchat, L R; Ryu, J-H

    2018-05-01

    We produced a Pseudomonas veronii biofilm on the surface of a stainless steel that is inhibitory to Escherichia coli O157:H7. Pseudomonas veronii strain KACC 81051BP, isolated from lettuce, readily formed biofilm on the surface of stainless steel coupons (SSCs) immersed in tryptic soy broth at 25°C. Cells showed significantly (P ≤ 0·05) enhanced tolerance to desiccation stress (43% relative humidity (RH)) and retained antimicrobial activity against E. coli O157:H7. The number of E. coli O157:H7 (control; 4·1 ± 0·1 log CFU per coupon) on sterile SSCs decreased to 2·7 ± 0·2 log CFU per coupon after exposure to 43% RH at 25°C for 48 h, while the population of E. coli O157:H7 (4·1 ± 0·0 log CFU per coupon) on SSCs containing P. veronii biofilm decreased to below the theoretical detection limit (1·5 log CFU per coupon) within 24 h. The antimicrobial biofilm produced on stainless steel may have application in preventing cross-contamination by E. coli O157:H7 on other abiotic surfaces in food-contact environments. The presence of Escherichia coli O157:H7 on environmental surfaces of food manufacturing, transportation and storage facilities is a significant food safety concern because it can result in cross-contamination of food products. In this study, we developed a Pseudomonas veronii biofilm on the surface of a stainless steel that inhibits the growth of E. coli O157:H7. Since P. veronii in biofilm resists desiccation, it provides persistent antimicrobial activity. Information presented here provides novel and practical insights to developing biological strategies to inactivate E. coli O157:H7 on diverse surfaces in food processing and handling environments. © 2018 The Society for Applied Microbiology.

  4. Hazardous solvent substitution

    International Nuclear Information System (INIS)

    Twitchell, K.E.

    1995-01-01

    This article is an overview of efforts at INEL to reduce the generation of hazardous wastes through the elimination of hazardous solvents. To aid in their efforts, a number of databases have been developed and will become a part of an Integrated Solvent Substitution Data System. This latter data system will be accessible through Internet

  5. Interaction of antibacterial compounds with RND efflux pumps in Pseudomonas aeruginosa

    Science.gov (United States)

    Dreier, Jürg; Ruggerone, Paolo

    2015-01-01

    Pseudomonas aeruginosa infections are becoming increasingly difficult to treat due to intrinsic antibiotic resistance and the propensity of this pathogen to accumulate diverse resistance mechanisms. Hyperexpression of efflux pumps of the Resistance-Nodulation-Cell Division (RND)-type multidrug efflux pumps (e.g., MexAB-OprM), chromosomally encoded by mexAB-oprM, mexCD-oprJ, mexEF-oprN, and mexXY (-oprA) is often detected in clinical isolates and contributes to worrying multi-drug resistance phenotypes. Not all antibiotics are affected to the same extent by the aforementioned RND efflux pumps. The impact of efflux on antibiotic activity varies not only between different classes of antibiotics but also between members of the same family of antibiotics. Subtle differences in physicochemical features of compound-pump and compound-solvent interactions largely determine how compounds are affected by efflux activity. The combination of different high-resolution techniques helps to gain insight into the functioning of these molecular machineries. This review discusses substrate recognition patterns based on experimental evidence and computer simulations with a focus on MexB, the pump subunit of the main RND transporter in P. aeruginosa. PMID:26217310

  6. Numerical taxonomy of heavy metal-tolerant bacteria isolated from an estuary

    Energy Technology Data Exchange (ETDEWEB)

    Austin, B.; Allen, D.A.; Mills, A.L.; Colwell, R.R.

    1977-01-01

    A total of 230 strains of metal-tolerant bacteria from water and sediment samples collected in Chesapeake Bay were isolated on medium containing cobalt, lead, mercury, or molybdenum. In addition, a set of 71 cultures were simultaneously isolated on glucose tryptone yeast extract agar medium without metals. Twenty-three reference strains were also included in the numerical taxonomy study of these bacteria, bringing the grand total of strains examined to 324. All strains were examined for 112 biochemical, cultural, morphological, and physiological characters. The taxonomic data obtained were analyzed by computer and the simple matching (S/sub SM/) and Jaccard (S/sub J) coefficients were calculated. Clustering achieved by unweighted average linkage is presented and, from sorted similarity matrices and dendrograms, 294 strains, i.e., 97% of the total, were recovered in 12 phenetic groups defined at the 75 to 80% similarity level. Among the strains there were nine phena presumptively identified as Bacillus, Erwinia, Mycobacterium, Pseudomonas, and coryneforms. From the results of the taxonomic study, it is concluded that metal tolerance in estuarine water and sediment bacteria occurs among a restricted range of taxa distributed throughout the estuarine environment. 61 references, 1 figure, 6 tables.

  7. Organic Solvent Tropical Report

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    2000-01-01

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an unmitigated organic solvent fire is within risk evaluation guidelines

  8. Diversity of Pseudomonas Genomes, Including Populus-Associated Isolates, as Revealed by Comparative Genome Analysis.

    Science.gov (United States)

    Jun, Se-Ran; Wassenaar, Trudy M; Nookaew, Intawat; Hauser, Loren; Wanchai, Visanu; Land, Miriam; Timm, Collin M; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A; Ussery, David W

    2016-01-01

    The Pseudomonas genus contains a metabolically versatile group of organisms that are known to occupy numerous ecological niches, including the rhizosphere and endosphere of many plants. Their diversity influences the phylogenetic diversity and heterogeneity of these communities. On the basis of average amino acid identity, comparative genome analysis of >1,000 Pseudomonas genomes, including 21 Pseudomonas strains isolated from the roots of native Populus deltoides (eastern cottonwood) trees resulted in consistent and robust genomic clusters with phylogenetic homogeneity. All Pseudomonas aeruginosa genomes clustered together, and these were clearly distinct from other Pseudomonas species groups on the basis of pangenome and core genome analyses. In contrast, the genomes of Pseudomonas fluorescens were organized into 20 distinct genomic clusters, representing enormous diversity and heterogeneity. Most of our 21 Populus-associated isolates formed three distinct subgroups within the major P. fluorescens group, supported by pathway profile analysis, while two isolates were more closely related to Pseudomonas chlororaphis and Pseudomonas putida. Genes specific to Populus-associated subgroups were identified. Genes specific to subgroup 1 include several sensory systems that act in two-component signal transduction, a TonB-dependent receptor, and a phosphorelay sensor. Genes specific to subgroup 2 contain hypothetical genes, and genes specific to subgroup 3 were annotated with hydrolase activity. This study justifies the need to sequence multiple isolates, especially from P. fluorescens, which displays the most genetic variation, in order to study functional capabilities from a pangenomic perspective. This information will prove useful when choosing Pseudomonas strains for use to promote growth and increase disease resistance in plants. Copyright © 2015 Jun et al.

  9. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

    Science.gov (United States)

    Cross, Megan; Biberacher, Sonja; Park, Suk-Youl; Rajan, Siji; Korhonen, Pasi; Gasser, Robin B; Kim, Jeong-Sun; Coster, Mark J; Hofmann, Andreas

    2018-04-24

    The opportunistic bacterium Pseudomonas aeruginosa has been recognized as an important pathogen of clinical relevance and is a leading cause of hospital-acquired infections. The presence of a glycolytic enzyme in Pseudomonas, which is known to be inhibited by trehalose 6-phosphate (T6P) in other organisms, suggests that these bacteria may be vulnerable to the detrimental effects of intracellular T6P accumulation. In the present study, we explored the structural and functional properties of trehalose 6-phosphate phosphatase (TPP) in P. aeruginosa in support of future target-based drug discovery. A survey of genomes revealed the existence of 2 TPP genes with either chromosomal or extrachromosomal location. Both TPPs were produced as recombinant proteins, and characterization of their enzymatic properties confirmed specific, magnesium-dependent catalytic hydrolysis of T6P. The 3-dimensional crystal structure of the chromosomal TPP revealed a protein dimer arising through β-sheet expansion of the individual monomers, which possess the overall fold of halo-acid dehydrogenases.-Cross, M., Biberacher, S., Park, S.-Y., Rajan, S., Korhonen, P., Gasser, R. B., Kim, J.-S., Coster, M. J., Hofmann, A. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

  10. Pseudomonas biofilm matrix composition and niche biology

    Science.gov (United States)

    Mann, Ethan E.; Wozniak, Daniel J.

    2014-01-01

    Biofilms are a predominant form of growth for bacteria in the environment and in the clinic. Critical for biofilm development are adherence, proliferation, and dispersion phases. Each of these stages includes reinforcement by, or modulation of, the extracellular matrix. Pseudomonas aeruginosa has been a model organism for the study of biofilm formation. Additionally, other Pseudomonas species utilize biofilm formation during plant colonization and environmental persistence. Pseudomonads produce several biofilm matrix molecules, including polysaccharides, nucleic acids, and proteins. Accessory matrix components shown to aid biofilm formation and adaptability under varying conditions are also produced by pseudomonads. Adaptation facilitated by biofilm formation allows for selection of genetic variants with unique and distinguishable colony morphology. Examples include rugose small-colony variants and wrinkly spreaders (WS), which over produce Psl/Pel or cellulose, respectively, and mucoid bacteria that over produce alginate. The well-documented emergence of these variants suggests that pseudomonads take advantage of matrix-building subpopulations conferring specific benefits for the entire population. This review will focus on various polysaccharides as well as additional Pseudomonas biofilm matrix components. Discussions will center on structure–function relationships, regulation, and the role of individual matrix molecules in niche biology. PMID:22212072

  11. Short communication: Pseudomonas azotoformans causes gray discoloration in HTST fluid milk.

    Science.gov (United States)

    Evanowski, Rachel L; Reichler, Samuel J; Kent, David J; Martin, Nicole H; Boor, Kathryn J; Wiedmann, Martin

    2017-10-01

    Pseudomonas species are well recognized as dairy product spoilage organisms, particularly due to their ability to grow at refrigeration temperatures. Although Pseudomonas-related spoilage usually manifests itself in flavor, odor, and texture defects, which are typically due to production of bacterial enzymes, Pseudomonas is also reported to cause color defects. Because of consumer complaints, a commercial dairy company shipped 4 samples of high temperature, short time (HTST)-pasteurized milk with distinctly gray colors to our laboratory. Bacterial isolates from all 4 samples were identified as Pseudomonas azotoformans. All isolates shared the same partial 16S rDNA sequence and showed black pigmentation on Dichloran Rose Bengal Chloramphenicol agar. Inoculation of one pigment-producing P. azotoformans isolate into HTST-pasteurized fluid milk led to development of gray milk after 14 d of storage at 6°C, but only in containers that had half of the total volume filled with milk (∼500 mL of milk in ∼1,000-mL bottles). We conclusively demonstrate that Pseudomonas can cause a color defect in fluid milk that manifests in gray discoloration, adding to the palette of color defects known to be caused by Pseudomonas. This information is of considerable interest to the dairy industry, because dairy processors and others may not typically associate black or gray colors in fluid milk with the presence of microbial contaminants but rather with product tampering (e.g., addition of ink) or other inadvertent chemical contamination. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

    Science.gov (United States)

    Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

    2014-01-01

    A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

  13. 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

  14. Efficacy of lactoferricin B in controlling ready-to-eat vegetable spoilage caused by Pseudomonas spp.

    Science.gov (United States)

    Federico, Baruzzi; Pinto, Loris; Quintieri, Laura; Carito, Antonia; Calabrese, Nicola; Caputo, Leonardo

    2015-12-23

    The microbial content of plant tissues has been reported to cause the spoilage of ca. 30% of chlorine-disinfected fresh vegetables during cold storage. The aim of this work was to evaluate the efficacy of antimicrobial peptides in controlling microbial vegetable spoilage under cold storage conditions. A total of 48 bacterial isolates were collected from ready-to-eat (RTE) vegetables and identified as belonging to Acinetobacter calcoaceticus, Aeromonas media, Pseudomonas cichorii, Pseudomonas fluorescens, Pseudomonas jessenii, Pseudomonas koreensis, Pseudomonas putida, Pseudomonas simiae and Pseudomonas viridiflava species. Reddish or brownish pigmentation was found when Pseudomonas strains were inoculated in wounds on leaves of Iceberg and Trocadero lettuce and escarole chicory throughout cold storage. Bovine lactoferrin (BLF) and its hydrolysates (LFHs) produced by pepsin, papain and rennin, were assayed in vitro against four Pseudomonas spp. strains selected for their heavy spoiling ability. As the pepsin-LFH showed the strongest antimicrobial effect, subsequent experiments were carried out using the peptide lactoferricin B (LfcinB), well known to be responsible for its antimicrobial activity. LfcinB significantly reduced (P ≤ 0.05) spoilage by a mean of 36% caused by three out of four inoculated spoiler pseudomonads on RTE lettuce leaves after six days of cold storage. The reduction in the extent of spoilage was unrelated to viable cell density in the inoculated wounds. This is the first paper providing direct evidence regarding the application of an antimicrobial peptide to control microbial spoilage affecting RTE leafy vegetables during cold storage.

  15. Hydrolytic potential of a psychrotrophic Pseudomonas isolated from refrigerated raw milk

    Directory of Open Access Journals (Sweden)

    Ana Paula F. Corrêa

    2011-12-01

    Full Text Available The production of extracellular hydrolases by a psychrotrophic bacterium isolated from refrigerated raw milk, and identified as a Pseudomonas sp. belonging to the Pseudomonas jenssenii group, was studied. This bacterium produced proteolytic and lipolytic enzymes in all media investigated (skim milk, cheese whey, casein broth, and tryptone soy broth. High levels of α-glucosidase were produced in skim milk broth. Hydrolytic enzymes detected in skim milk broth are of particular concern, indicating that these enzymes could be produced by Pseudomonas sp. during the cold storage of raw milk, contributing to the spoilage problem in milk and dairy products.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

  17. Detectie en beheersing van bacterierot veroorzaakt door Pseudomonas cattleyae in Phalaenopsis

    NARCIS (Netherlands)

    Ludeking, D.J.W.; Hamelink, R.; Kromwijk, J.A.M.; Schenk, M.F.; Vermunt, A.; Woets, F.

    2011-01-01

    Phalaenopsis growers suffer from mayor losses up to 20% due to bacterial spot. This bacterial infection in caused by the Acidovorax avenae subsp. cattleyae. In practice this bacterial disease is also known as Pseudomonas. This bacterium is causing black leaf spots with a yellow border. Pseudomonas

  18. Insecticide solvents: interference with insecticidal action.

    Science.gov (United States)

    Brattsten, L B; Wilkinson, C F

    1977-06-10

    Several commercial solvent mixtures commonly used as insecticide carriers in spray formulations increase by more than threefold the microsomal N-demethylation of p-chloro N-methylaniline in midgut preparations of southern army-worm (Spodoptera eridania) larvae exposed orally to the test solvents. Under laboratory conditions, the same solvent mixtures exhibit a protective action against the in vivo toxicity of the insecticide carbaryl to the larvae. The data are discussed with respect to possible solvent-insecticide interactions occurring under field conditions and, more broadly, to potential toxicological hazards of these solvents to humans.

  19. Semi-scale production of PHAs from waste frying oil by Pseudomonas fluorescens S48

    Directory of Open Access Journals (Sweden)

    Rawia F. Gamal

    2013-01-01

    Full Text Available The present study aimed at developing a strategy to improve the volumetric production of PHAs by Pseudomonas fluorescens S48 using waste frying oil (WFO as the sole carbon source. For this purpose, several cultivations were set up to steadily improve nutrients supply to attain high cell density and high biopolymer productivity. The production of PHAs was examined in a 14 L bioreactor as one-stage batch, two-stage batch, and high-cell-density fed-batch cultures. The highest value of polymer content in one-stage bioreactor was obtained after 60 h (33.7%. Whereas, the two-stage batch culture increased the polymer content to 50.1% after 54 h. High-cell-density (0.64 g/L at continuous feeding rate 0.55 mL/l/h of WFO recorded the highest polymer content after 54 h (55.34%. Semi-scale application (10 L working volume increased the polymer content in one-stage batch, two-stage batch and high cell density fed-batch cultures by about 12.3%, 5.8% and 11.3%, respectively, as compared with that obtained in 2 L fermentation culture. Six different methods for biopolymer extraction were done to investigate their efficiency for optimum polymer recovery. The maximum efficiency of solvent recovery of PHA was attained by chloroform-hypochlorite dispersion extraction. Gas chromatography (GC analysis of biopolymer produced by Pseudomonas fluorescens S48 indicated that it solely composed of 3-hydrobutyric acid (98.7%. A bioplastic film was prepared from the obtained PHB. The isolate studied shares the same identical sequence, which is nearly the complete 16S rRNA gene. The identity of this sequence to the closest pseudomonads strains is about 98-99%. It was probably closely related to support another meaningful parsiomony analysis and construction of a phylogenetic tree. The isolate is so close to Egyptian strain named EG 639838.

  20. Comparative In Vitro Efficacy of Doripenem and Imipenem Against Multi-Drug Resistant Pseudomonas aeruginosa.

    Science.gov (United States)

    Wali, Nadia; Mirza, Irfan Ali

    2016-04-01

    To compare the in vitro efficacy of doripenem and imipenem against multi-drug resistant (MDR) Pseudomonas aeruginosa from various clinical specimens. Descriptive cross-sectional study. Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from November 2012 to November 2013. MDR Pseudomonas aeruginosa isolates from various clinical samples were included in the study. Susceptibility of Pseudomonas aeruginosa against doripenem and imipenem was performed by E-test strip and agar dilution methods. The results were interpreted as recommended by Clinical Laboratory Standard Institute (CLSI) guidelines. The maximum number of Pseudomonas aeruginosa were isolated from pure pus and pus swabs. In vitro efficacy of doripenem was found to be more effective as compared to imipenem against MDR Pseudomonas aeruginosa with both E-test strip and agar dilution methods. Overall, p-values of 0.014 and 0.037 were observed when susceptibility patterns of doripenem and imipenem were evaluated with E-test strip and agar dilution methods. In vitro efficacy of doripenem was found to be better against MDR Pseudomonas aeruginosaas compared to imipenem when tested by both E-test and agar dilution methods.

  1. Combined inoculation of Pseudomonas fluorescens and Trichoderma harzianum for enhancing plant growth of vanilla (Vanilla planifolia).

    Science.gov (United States)

    Sandheep, A R; Asok, A K; Jisha, M S

    2013-06-15

    This study was conducted to evaluate the plant growth promoting efficiency of combined inoculation of rhizobacteria on Vanilla plants. Based on the in vitro performance of indigenous Trichoderma spp. and Pseudomonas spp., four effective antagonists were selected and screened under greenhouse experiment for their growth enhancement potential. The maximum percentage of growth enhancement were observed in the combination of Trichoderma harzianum with Pseudomonas fluorescens treatment followed by Pseudomonas fluorescens, Trichoderma harzianum, Pseudomonas putida and Trichoderma virens, respectively in decreasing order. Combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens registered the maximum length of vine (82.88 cm), highest number of leaves (26.67/plant), recorded the highest fresh weight of shoots (61.54 g plant(-1)), fresh weight of roots (4.46 g plant(-1)) and dry weight of shoot (4.56 g plant(-1)) where as the highest dry weight of roots (2.0806 g plant(-1)) were achieved with treatments of Pseudomonas fluorescens. Among the inoculated strains, combined inoculation of Trichoderma harzianum and Pseudomonas fluorescens recorded the maximum nitrogen uptake (61.28 mg plant(-1)) followed by the combined inoculation of Trichoderma harzianum (std) and Pseudomonas fluorescens (std) (55.03 mg plant(-1)) and the highest phosphorus uptake (38.80 mg plant(-1)) was recorded in dual inoculation of Trichoderma harzianum and Pseudomonas fluorescens.

  2. Next Generation Solvent (NGS): Development for Caustic-Side Solvent Extraction of Cesium

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Birdwell, Jr, Joseph F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bonnesen, Peter V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Delmau, Laetitia Helene [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Duncan, Nathan C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ensor, Dale [Tennessee Technological Univ., Cookeville, TN (United States); Hill, Talon G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Denise L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rajbanshi, Arbin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roach, Benjamin D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Szczygiel, Patricia L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sloop, Jr., Frederick V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Stoner, Erica L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Neil J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-03-01

    This report summarizes the FY 2010 and 2011 accomplishments at Oak Ridge National Laboratory (ORNL) in developing the Next Generation Caustic-Side Solvent Extraction (NG-CSSX) process, referred to commonly as the Next Generation Solvent (NGS), under funding from the U.S. Department of Energy, Office of Environmental Management (DOE-EM), Office of Technology Innovation and Development. The primary product of this effort is a process solvent and preliminary flowsheet capable of meeting a target decontamination factor (DF) of 40,000 for worst-case Savannah River Site (SRS) waste with a concentration factor of 15 or higher in the 18-stage equipment configuration of the SRS Modular Caustic-Side Solvent Extraction Unit (MCU). In addition, the NG-CSSX process may be readily adapted for use in the SRS Salt Waste Processing Facility (SWPF) or in supplemental tank-waste treatment at Hanford upon appropriate solvent or flowsheet modifications. Efforts in FY 2010 focused on developing a solvent composition and process flowsheet for MCU implementation. In FY 2011 accomplishments at ORNL involved a wide array of chemical-development activities and testing up through single-stage hydraulic and mass-transfer tests in 5-cm centrifugal contactors. Under subcontract from ORNL, Argonne National Laboratory (ANL) designed a preliminary flowsheet using ORNL cesium distribution data, and Tennessee Technological University confirmed a chemical model for cesium distribution ratios (DCs) as a function of feed composition. Interlaboratory efforts were coordinated with complementary engineering tests carried out (and reported separately) by personnel at Savannah River National Laboratory (SRNL) and Savannah River Remediation (SRR) with helpful advice by Parsons Engineering and General Atomics on aspects of possible SWPF implementation.

  3. [Risk factors for Pseudomonas aeruginosa infections, resistant to carbapenem].

    Science.gov (United States)

    Ghibu, Laura; Miftode, Egidia; Teodor, Andra; Bejan, Codrina; Dorobăţ, Carmen Mihaela

    2010-01-01

    Since their introduction in clinical practice,carbapenems have been among the most powerful antibiotics for treating serious infections cased by Gram-negative nosocomial pathogens, including Pseudomonas aeruginosa. The emergence of betalactamases with carbapenem-hydrolyzing activity is of major clinical concern. Pseudomonas aeruginosa is a leading cause of nosocomial infection. Risk factors for colonization with carbapenems-resistant Pseudomonas in hospital are: history of P. aeruginosa infection or colonization within the previous year, (length of hospital stay, being bedridden or in the ICU, mechanical ventilation, malignant disease, and history of chronic obstructive pulmonary disease have all been identified as independent risk factors for MDR P. aeruginosa infection. Long-term-care facilities are also reservoirs of resistant bacteria. Risk factors for colonization of LTCF residents with resistant bacteria included age > 86 years, antibiotic treatment in the previous 3 months, indwelling devices, chronic obstructive pulmonary disease, physical disability, and the particular LTCF unit.

  4. Computer Aided Solvent Selection and Design Framework

    DEFF Research Database (Denmark)

    Mitrofanov, Igor; Conte, Elisa; Abildskov, Jens

    and computer-aided tools and methods for property prediction and computer-aided molecular design (CAMD) principles. This framework is applicable for solvent selection and design in product design as well as process design. The first module of the framework is dedicated to the solvent selection and design...... in terms of: physical and chemical properties (solvent-pure properties); Environment, Health and Safety (EHS) characteristic (solvent-EHS properties); operational properties (solvent–solute properties). 3. Performing the search. The search step consists of two stages. The first is a generation and property...... identification of solvent candidates using special software ProCAMD and ProPred, which are the implementations of computer-aided molecular techniques. The second consists of assigning the RS-indices following the reaction–solvent and then consulting the known solvent database and identifying the set of solvents...

  5. Improvements in solvent extraction columns

    International Nuclear Information System (INIS)

    Aughwane, K.R.

    1987-01-01

    Solvent extraction columns are used in the reprocessing of irradiated nuclear fuel. For an effective reprocessing operation a solvent extraction column is required which is capable of distributing the feed over most of the column. The patent describes improvements in solvent extractions columns which allows the feed to be distributed over an increased length of column than was previously possible. (U.K.)

  6. The Pseudomonas community in metal-contaminated sediments as revealed by quantitative PCR: a link with metal bioavailability.

    Science.gov (United States)

    Roosa, Stéphanie; Wauven, Corinne Vander; Billon, Gabriel; Matthijs, Sandra; Wattiez, Ruddy; Gillan, David C

    2014-10-01

    Pseudomonas bacteria are ubiquitous Gram-negative and aerobic microorganisms that are known to harbor metal resistance mechanisms such as efflux pumps and intracellular redox enzymes. Specific Pseudomonas bacteria have been quantified in some metal-contaminated environments, but the entire Pseudomonas population has been poorly investigated under these conditions, and the link with metal bioavailability was not previously examined. In the present study, quantitative PCR and cell cultivation were used to monitor and characterize the Pseudomonas population at 4 different sediment sites contaminated with various levels of metals. At the same time, total metals and metal bioavailability (as estimated using an HCl 1 m extraction) were measured. It was found that the total level of Pseudomonas, as determined by qPCR using two different genes (oprI and the 16S rRNA gene), was positively and significantly correlated with total and HCl-extractable Cu, Co, Ni, Pb and Zn, with high correlation coefficients (>0.8). Metal-contaminated sediments featured isolates of the Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas lutea and Pseudomonas aeruginosa groups, with other bacterial genera such as Mycobacterium, Klebsiella and Methylobacterium. It is concluded that Pseudomonas bacteria do proliferate in metal-contaminated sediments, but are still part of a complex community. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  7. Overexpression of a bacterial mercury transporter MerT in Arabidopsis enhances mercury tolerance.

    Science.gov (United States)

    Xu, Sheng; Sun, Bin; Wang, Rong; He, Jia; Xia, Bing; Xue, Yong; Wang, Ren

    2017-08-19

    The phytoremediation by using of green plants in the removal of environmental pollutant is an environment friendly, green technology that is cost effective and energetically inexpensive. By using Agrobacterium-mediated gene transfer, we generated transgenic Arabidopsis plants ectopically expressing mercuric transport protein gene (merT) from Pseudomonas alcaligenes. Compared with wild-type (WT) plants, overexpressing PamerT in Arabidopsis enhanced the tolerance to HgCl 2 . Further results showed that the enhanced total activities or corresponding transcripts of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT) and guaiacol peroxidase (POD) were observed in transgenic Arabidopsis under HgCl 2 stress. These results were confirmed by the alleviation of oxidative damage, as indicated by the decrease of thiobarbituric acid reactive substances (TBARS) contents and reactive oxygen species (ROS) accumulation. In addition, localization analysis of PaMerT in Arabidopsis protoplast showed that it is likely to be associated with vacuole. In all, PamerT increased mercury (Hg) tolerance in transgenic Arabidopsis, and decreased production of Hg-induced ROS, thereby protecting plants from oxidative damage. The present study has provided further evidence that bacterial MerT plays an important role in the plant tolerance to HgCl 2 and in reducing the production of ROS induced by HgCl 2 . Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Gas separation by composite solvent-swollen membranes

    Science.gov (United States)

    Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

    1989-01-01

    There is disclosed a composite immobulized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorous or sulfur atom, and having a boiling point of at least 100.degree. C. and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation.

  9. Gas separation by composite solvent-swollen membranes

    Science.gov (United States)

    Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

    1989-04-25

    There is disclosed a composite immobilized liquid membrane of a solvent-swollen polymer and a microporous organic or inorganic support, the solvent being at least one highly polar solvent containing at least one nitrogen, oxygen, phosphorus or sulfur atom, and having a boiling point of at least 100 C and a specified solubility parameter. The solvent or solvent mixture is homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. The membrane is suitable for acid gas scrubbing and oxygen/nitrogen separation. 3 figs.

  10. Pseudomonas floridensis sp. nov., a bacterial pathogen isolated from tomato.

    Science.gov (United States)

    Timilsina, Sujan; Minsavage, Gerald V; Preston, James; Newberry, Eric A; Paret, Matthews L; Goss, Erica M; Jones, Jeffrey B; Vallad, Gary E

    2018-01-01

    An unusual fluorescent pseudomonad was isolated from tomato exhibiting leaf spot symptoms similar to bacterial speck. Strains were fluorescent, oxidase- and arginine-dihydrolase-negative, elicited a hypersensitive reaction on tobacco and produced a soft rot on potato slices. However, the strains produced an unusual yellow, mucoid growth on media containing 5 % sucrose that is not typical of levan. Based on multilocus sequence analysis using 16S rRNA, gap1, gltA, gyrB and rpoD, these strains formed a distinct phylogenetic group in the genus Pseudomonas and were most closely related to Pseudomonas viridiflava within the Pseudomonassyringae complex. Whole-genome comparisons, using average nucleotide identity based on blast, of representative strain GEV388 T and publicly available genomes representing the genus Pseudomonas revealed phylogroup 7 P. viridiflava strain UASW0038 and P. viridiflava type strain ICMP 2848 T as the closest relatives with 86.59 and 86.56 % nucleotide identity, respectively. In silico DNA-DNA hybridization using the genome-to-genome distance calculation method estimated 31.1 % DNA relatedness between GEV388 T and P. viridiflava ATCC 13223 T , strongly suggesting the strains are representatives of different species. These results together with Biolog GEN III tests, fatty acid methyl ester profiles and phylogenetic analysis using 16S rRNA and multiple housekeeping gene sequences demonstrated that this group represents a novel species member of the genus Pseudomonas. The name Pseudomonas floridensis sp. nov. is proposed with GEV388 T (=LMG 30013 T =ATCC TSD-90 T ) as the type strain.

  11. Pseudomonas aeruginosa (Family Pseudomonadaceae) is an ...

    African Journals Online (AJOL)

    Pseudomonas aeruginosa (Family Pseudomonadaceae) is an obligate aerobic, motile, gram negative bacillus.which is able to grow and survive in almost any environment and resistant to temperature extremes. It is involved in the etiology of several diseases i.

  12. Vaccines for preventing infection with Pseudomonas aeruginosa in cystic fibrosis.

    Science.gov (United States)

    Johansen, Helle Krogh; Gøtzsche, Peter C

    2015-08-23

    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. To assess the effectiveness of vaccination against Pseudomonas aeruginosa in cystic fibrosis. 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). Randomised trials (published or unpublished) comparing Pseudomonas aeruginosa vaccines (oral, parenteral or intranasal) with control vaccines or no intervention in cystic fibrosis. The authors independently selected trials, assessed them and extracted data. Six trials were identified. Two trials were excluded since they were not randomised and one old, small trial because it was not possible to assess whether is was randomised. The three included trials comprised 483, 476 and 37 patients, respectively. No data have been published from one of the large trials, but the company stated in a press release that the trial failed to confirm the results from an earlier study and that further clinical development was suspended. In the other large trial, relative risk for chronic infection was 0.91 (95% confidence interval 0.55 to 1.49), and in the small trial, the risk was also close to one. In the large trial, one patient was reported to have died in the observation period. In that trial, 227 adverse events (4 severe) were registered in the vaccine group and 91 (1 severe) in the control group. In this large trial of a vaccine developed against flagella antigens, antibody titres against the epitopes contained in the vaccine were higher in the vaccine group compared to the placebo group (P Vaccines against

  13. Processing of polymers using reactive solvents

    NARCIS (Netherlands)

    Lemstra, P.J.; Kurja, J.; Meijer, H.E.H.; Meijer, H.E.H.

    1997-01-01

    A review with many refs. on processing of polymers using reactive solvents including classification of synthetic polymers, guidelines for the selection of reactive solvents, basic aspects of processing, examples of intractable and tractable polymer/reactive solvent system

  14. 40 CFR Table 4 to Subpart Oooo of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction... formulation data. Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent...

  15. Isolation, production, purification and characterization of an organic-solvent-thermostable alkalophilic cellulase from Bacillus vallismortis RG-07.

    Science.gov (United States)

    Gaur, Rajeeva; Tiwari, Soni

    2015-03-19

    The rising concerns about the scarcity of fossil fuels, the emission of green house gasses and air pollution by incomplete combustion of fossil fuel have also resulted in an increasing focus on the use of cellulases to perform enzymatic hydrolysis of the lignocellulosic materials for the generation of bioethanol. The aim of this study was to isolate a potential thermo-solvent tolerant cellulase producing bacterium from natural resources, and then applied for purification and characterization. The purified enzyme was to be accessible for the bioethanol production as well as industrial exploitation (discuss in our next study). It is the first instance when thermo-solvent tolerant cellulase producing bacterium was isolated from soil sample. The culture was identified as Bacillus vallismortis RG-07 by 16S rDNA sequence analysis. Bacillus vallismortis RG-07 reported maximum cellulase production from sugarcane baggase (4105 U ml(-1)) used as agro-waste carbon source. The cellulase enzyme produced by the Bacillus sp. was purified by (NH4)2SO4 precipitation, ion exchange and gel filtration chromatography, with overall recovery of 28.8%. The molecular weight of purified cellulase was 80 kDa as revealed by SDS-PAGE and activity gel analysis. The optimum temperature and pH for enzyme activity was determined as 65°C and 7.0 and it retained 95 and 75% of activity even at 95°C, and 9.0 respectively. The enzyme activity was enhanced in the presence of organic solvents (30%) n-dodecane, iso-octane, n-decane, xylene, toluene, n-haxane, n-butanol, and cyclohexane, after prolonged incubation (7 days). The enzyme activity was also stimulated by Ca(2+), mercaptoethanol, Tween-60, and Sodium hypochloride whereas strongly inhibited by Hg. Kinetic analysis of purified enzyme showed the Km and Vmax to be 1.923 mg ml(-1) and 769.230 μg ml(-1) min(-1), respectively. The unique property of solvent-thermostable-alkalophilic, nature proves the potential candidature of this isolate for

  16. Effects of solvent and structure on the reactivity of 6-substituted nicotinic acids with diazodiphenylmethane in aprotic solvents

    Directory of Open Access Journals (Sweden)

    BRATISLAV Ž. JOVANOVIĆ

    2009-12-01

    Full Text Available The rate constants for the reactions of diazodiphenylmethane (DDM with 6-substituted nicotinic acids in aprotic solvents at 30 °C were determined. The obtained second order rate constants in aprotic solvents, together with literature data for benzoic and nicotinic acids in protic solvents, were used for the calculation of solvent effects, employing the Kamlet-Taft solvatochromic equation (linear solvation energy relationship – LSER in the form: log k = log k0 + s* + a + b. The correlations of the kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The sign of the equation coefficients (s, a and b were in agreement with the postulated reaction mechanism, and the mode of the solvent influences on the reaction rate is discussed based on the correlation results. A similar contribution of the non-specific solvent effect and electrophilic solvation was observed for all acids, while the highest contribution of nucleophilic solvation was influenced by their high acidity. Correlation analysis of the rate data with substituent p parameters in an appropriate solvent using the Hammett equation was also performed. The substituent effect on the acid reactivity was higher in aprotic solvents of higher dipolarity/polarizability. The mode of the transmission of the substituent effect is discussed in light of the contribution of solute–solvent interaction on the acid reactivity.

  17. Genetic Diversity of Nitrogen-Fixing and Plant Growth Promoting Pseudomonas Species Isolated from Sugarcane Rhizosphere.

    Science.gov (United States)

    Li, Hai-Bi; Singh, Rajesh K; Singh, Pratiksha; Song, Qi-Qi; Xing, Yong-Xiu; Yang, Li-Tao; Li, Yang-Rui

    2017-01-01

    phenotypic profiling, which comprised utilization of C and N sources, and tolerance to osmolytes and pH, revealed the metabolic versatility of the selected strains. The colonization ability of the selected strains was evaluated by genetically tagging them with a constitutively expressing GFP-pPROBE-pTet r -OT plasmid. qRT-PCR results showed that both strains had the ability to express the nifH gene at 90 and 120 days, as compared to a control, in both sugarcane varieties GT11 and GXB9. Therefore, our isolated strains, P. koreensis and P. entomophila may be used as inoculums or in biofertilizer production for enhancing growth and nutrients, as well as for improving nitrogen levels, in sugarcane and other crops. The present study, to the best of our knowledge, is the first report on the diversity of Pseudomonas spp. associated with sugarcane in Guangxi, China.

  18. 40 CFR Table 3 to Subpart IIIi of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... Solvent/solvent blend CAS. No. Averageorganic HAP mass fraction Typical organic HAP, percent by mass 1...

  19. 40 CFR Table 5 to Subpart Qqqq of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the.... Solvent/solvent blend CAS. No. Average organic HAP mass fraction Typical organic HAP, percent by mass 1...

  20. Comparative In Vitro Efficacy of Doripenem and Imipenem Against Multi-Drug Resistant Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Wali, N.; Mirza, I. A.

    2016-01-01

    Objective: To compare the in vitro efficacy of doripenem and imipenem against multi-drug resistant (MDR) Pseudomonas aeruginosa from various clinical specimens. Study Design: Descriptive cross-sectional study. Place and Duration of Study: Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, from November 2012 to November 2013. Methodology: MDR Pseudomonas aeruginosa isolates from various clinical samples were included in the study. Susceptibility of Pseudomonas aeruginosa against doripenem and imipenem was performed by E-test strip and agar dilution methods. The results were interpreted as recommended by Clinical Laboratory Standard Institute (CLSI) guidelines. Results: The maximum number of Pseudomonas aeruginosa were isolated from pure pus and pus swabs. In vitro efficacy of doripenem was found to be more effective as compared to imipenem against MDR Pseudomonas aeruginosa with both E-test strip and agar dilution methods. Overall, p-values of 0.014 and 0.037 were observed when susceptibility patterns of doripenem and imipenem were evaluated with E-test strip and agar dilution methods. Conclusion: In vitro efficacy of doripenem was found to be better against MDR Pseudomonas aeruginosa as compared to imipenem when tested by both E-test and agar dilution methods. (author)

  1. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Activation of Pseudomonas aeruginosa elastase in Pseudomonas putida by triggering dissociation of the propeptide-enzyme complex

    NARCIS (Netherlands)

    Braun, P; Bitter, W; Tommassen, J

    2000-01-01

    The propeptide of Pseudomonas aeruginosa elastase functions both as an intramolecular chaperone required for the folding of the enzyme and as an inhibitor that prevents activity of the enzyme before its secretion into the extracellular medium. Since expression of the lasB gene, which encodes

  3. Solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents

    International Nuclear Information System (INIS)

    Fan, Jie-Ping; Yang, Dan; Xu, Xiao-Kang; Guo, Xiao-Jie; Zhang, Xue-Hong

    2015-01-01

    Highlights: • The solubilities of daidzin were measured in various solvents. • The solubility data were correlated by three models. • The thermodynamic properties of the dissolution process were also determined. - Abstract: The solubility of daidzin in different organic solvents and (ethyl alcohol + water) mixed solvents was measured by high performance liquid chromatography (HPLC) analysis method from T = (283.2 to 323.2) K at atmosphere pressure. The results show that at higher temperature more daidzin dissolves, and moreover, the solubility increases with the ethyl alcohol mole fraction increase in the (ethyl alcohol + water) mixed solvents. The experimental solubility values were correlated by a simplified thermodynamic equation, λh equation and modified Apelblat equation. Based on the solubility of daidzin, the enthalpy and entropy of solution were also evaluated by van’t Hoff equation. The results illustrated that the dissolution process of daidzin is endothermic and entropy driven

  4. Expression analysis of the gacS mutant of Pseudomonas fluorescens SBW25

    NARCIS (Netherlands)

    Cheng, Xu; Bruijn, de Irene; Voort, van der M.; Raaijmakers, Jos

    2013-01-01

    Pseudomonas species are ubiquitous in plant-associated environments and produce an array of volatiles, enzymes and antimicrobials. The biosynthesis of many metabolites is regulated by the GacS/GacA two-component regulatory system. Transcriptome analysis of Pseudomonas fluorescens SBW25 revealed that

  5. Growth of Pseudomonas fluorescens on Cassava Starch ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: The potential of local strains of microorganism (Pseudomonas fluorescens) in polyhydroxbutyrate production ... The demand for the use of biopolymers ... This work therefore investigates the production of polyhydroxybutyrate from.

  6. Adaptive Resolution Simulation of MARTINI Solvents

    NARCIS (Netherlands)

    Zavadlav, Julija; Melo, Manuel N.; Cunha, Ana V.; de Vries, Alex H.; Marrink, Siewert J.; Praprotnik, Matej

    We present adaptive resolution dynamics simulations of aqueous and apolar solvents coarse-grained molecular models that are compatible with the MARTINI force field. As representatives of both classes solvents we have chosen liquid water and butane, respectively, at ambient temperature. The solvent

  7. Green and Bio-Based Solvents.

    Science.gov (United States)

    Calvo-Flores, Francisco G; Monteagudo-Arrebola, María José; Dobado, José A; Isac-García, Joaquín

    2018-04-24

    Chemical reactions and many of the procedures of separation and purification employed in industry, research or chemistry teaching utilize solvents massively. In the last decades, with the birth of Green Chemistry, concerns about the employment of solvents and the effects on human health, as well as its environmental impacts and its dependence on non-renewable raw materials for manufacturing most of them, has drawn the attention of the scientific community. In this work, we review the concept of green solvent and the properties and characteristics to be considered green. Additionally, we discuss the different possible routes to prepare many solvents from biomass, as an alternative way to those methods currently applied in the petrochemical industry.

  8. Enhanced Production and Characterization of a Solvent Stable Amylase from Solvent Tolerant Bacillus tequilensis RG-01: Thermostable and Surfactant Resistant

    Directory of Open Access Journals (Sweden)

    Soni Tiwari

    2014-01-01

    Full Text Available Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL in the presence of starch, peptone, and Ca2+ ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1% and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5% on amylase activity. This isolate (Bacillus tequilensis RG-01 may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

  9. Transformation of carbon tetrachloride by Pseudomonas sp. strain KC under denitrification conditions

    International Nuclear Information System (INIS)

    Criddle, C.S.; DeWitt, J.T.; Grbic-Galic, D.; McCarty, P.L.

    1990-01-01

    A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of 14 C-labeled CT by Pseudomonas strain KC under denitrification conditions were 14 CO 2 and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging

  10. Potent Antibacterial Antisense Peptide-Peptide Nucleic Acid Conjugates Against Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

    Ghosal, Anubrata; Nielsen, Peter E

    2012-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen causing severe infections in hospital settings, especially with immune compromised patients, and the increasing prevalence of multidrug resistant strains urges search for new drugs with novel mechanisms of action. In this study we introduce...... significantly reduced bacterial survival. These results open the possibility of development of antisense antibacterials for treatment of Pseudomonas infections....

  11. Solvent Extraction of Furfural From Biomass

    Science.gov (United States)

    Humphrey, M. F.

    1984-01-01

    Solvent-extraction method reduces energy required to remove furfural produced during acid hydrolysis of biomass. Acid hydrolysis performed in vessel containing both solvents and reacting ingredients. With intimate contact between solvents and aqueous hydrolyis liqour, furfural removed form liquor almost as fast as it forms.

  12. Biodiesel production from ethanolysis of palm oil using deep eutectic solvent (DES) as co-solvent

    Science.gov (United States)

    Manurung, R.; Winarta, A.; Taslim; Indra, L.

    2017-06-01

    Biodiesel produced from ethanolysis is more renewable and have better properties (higher oxidation stability, lower cloud and pour point) compared to methanolysis, but it has a disadvantage such as complicated purification. To improve ethanolysis process, deep eutectic solvent (DES) can be prepared from choline chloride and glycerol and used as co-solvent in ethanolysis. The deep eutectic solvent is formed from a quaternary ammonium salt (choline chloride) and a hydrogen bond donor (Glycerol), it is a non-toxic, biodegradable solvent compared to a conventional volatile organic solvent such as hexane. The deep eutectic solvent is prepared by mixing choline chloride and glycerol with molar ratio 1:2 at temperature 80 °C, stirring speed 300 rpm for 1 hour. The DES is characterized by its density and viscosity. The ethanolysis is performed at a reaction temperature of 70 °C, ethanol to oil molar ratio of 9:1, potassium hydroxide as catalyst concentration of 1.2 wt. DES as co-solvent with concentration 0.5 to 3 wt. stirring speed 400 rpm, and a reaction time 1 hour. The obtained biodiesel is then characterized by its density, viscosity, and ester content. The oil - ethanol phase condition is observed in the reaction tube. The oil - ethanol phase with DES tends to form meniscus compared to without DES, showed that oil and ethanol become more slightly miscible, which favors the reaction. Using DES as co-solvent in ethanolysis showed increasing in yield and easier purification. The esters properties meet the international standards ASTM D6751, with the highest yield achieved 83,67 with 99,77 conversion at DES concentration 2 . Increasing DES concentration above 2 in ethanolysis decrease the conversion and yield, because of the excessive glycerol in the systems makes the reaction equilibrium moves to the reactant side.

  13. Acetone-based cellulose solvent.

    Science.gov (United States)

    Kostag, Marc; Liebert, Tim; Heinze, Thomas

    2014-08-01

    Acetone containing tetraalkylammonium chloride is found to be an efficient solvent for cellulose. The addition of an amount of 10 mol% (based on acetone) of well-soluble salt triethyloctylammonium chloride (Et3 OctN Cl) adjusts the solvent's properties (increases the polarity) to promote cellulose dissolution. Cellulose solutions in acetone/Et3 OctN Cl have the lowest viscosity reported for comparable aprotic solutions making it a promising system for shaping processes and homogeneous chemical modification of the biopolymer. Recovery of the polymer and recycling of the solvent components can be easily achieved. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Determinación de aislados nativos de pseudomonas desulfurizadoras mediante el estudio del perfil de ácidos grasos

    Directory of Open Access Journals (Sweden)

    Edilberto Silva Gómez

    2010-09-01

    Full Text Available Utilizando CGAR se determinó el contenido de ácidos grasos celulares de doce aislados colombianos, Pseudomonas aeruginosa 17, 18, 19, 20, 21, 22 y 103, Pseudomonas sp 23, 24, 25, 26 y 27 con capacidad desulfurizadora, Pseudomonas aeruginosa ATCC 9027 y 10145, Pseudomonas sp ATCC 39327 y Pseudomonas flúores cens. Se encontraron 53 ácidos grasos diferentes, entre saturados e insaturados de cadena lineal, y principalmente hidroxiácidos y ramificados.

  15. Occurrence of multi-antibiotic resistant Pseudomonas spp. in drinking water produced from karstic hydrosystems.

    Science.gov (United States)

    Flores Ribeiro, Angela; Bodilis, Josselin; Alonso, Lise; Buquet, Sylvaine; Feuilloley, Marc; Dupont, Jean-Paul; Pawlak, Barbara

    2014-08-15

    Aquatic environments could play a role in the spread of antibiotic resistance genes by enabling antibiotic-resistant bacteria transferred through wastewater inputs to connect with autochthonous bacteria. Consequently, drinking water could be a potential pathway to humans and animals for antibiotic resistance genes. The aim of this study was to investigate occurrences of Escherichia coli and Pseudomonas spp. in drinking water produced from a karst, a vulnerable aquifer with frequent increases in water turbidity after rainfall events and run-offs. Water samples were collected throughout the system from the karstic springs to the drinking water tap during three non-turbid periods and two turbid events. E. coli densities in the springs were 10- to 1000-fold higher during the turbid events than during the non-turbid periods, indicating that, with increased turbidity, surface water had entered the karstic system and contaminated the spring water. However, no E. coli were isolated in the drinking water. In contrast, Pseudomonas spp. were isolated from the drinking water only during turbid events, while the densities in the springs were from 10- to 100-fold higher than in the non-turbid periods. All the 580 Pseudomonas spp. isolates obtained from the sampling periods were resistant (to between 1 and 10 antibiotics), with similar resistance patterns. Among all the Pseudomonas isolated throughout the drinking water production system, between 32% and 86% carried the major resistance pattern: ticarcillin, ticarcillin-clavulanic acid, cefsulodin, and/or aztreonam, and/or sulfamethoxazol-trimethoprim, and/or fosfomycin. Finally, 8 Pseudomonas spp. isolates, related to the Pseudomonas putida and Pseudomonas fluorescens species, were isolated from the drinking water. Thus, Pseudomonas could be involved in the dissemination of antibiotic resistance via drinking water during critical periods. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Pseudomonas versuta sp. nov., isolated from Antarctic soil.

    Science.gov (United States)

    See-Too, Wah Seng; Salazar, Sergio; Ee, Robson; Convey, Peter; Chan, Kok-Gan; Peix, Álvaro

    2017-06-01

    In this study we analysed three bacterial strains coded L10.10 T , A4R1.5 and A4R1.12, isolated in the course of a study of quorum-quenching bacteria occurring in Antarctic soil. The 16S rRNA gene sequence was identical in the three strains and showed 99.7% pairwise similarity with respect to the closest related species Pseudomonas weihenstephanensis WS4993 T . Therefore, the three strains were classified within the genus Pseudomonas. Analysis of housekeeping genes (rpoB, rpoD and gyrB) sequences showed similarities of 84-95% with respect to the closest related species of Pseudomonas, confirming its phylogenetic affiliation. The ANI values were less than 86% to the closest related species type strains. The respiratory quinone is Q9. The major fatty acids are C16:0, C16:1 ω7c/ C16:1 ω6c in summed feature 3 and C18:1 ω7c / C18:1 ω6c in summed feature 8. The strains are oxidase- and catalase-positive. Growth occurs at 4-30°C, and at pH 4.0-10. The DNA G+C content is 58.2-58.3mol %. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strains L10.10 T , A4R1.5 and A4R1.12 into a novel species of Pseudomonas, for which the name P. versuta sp. nov. is proposed. The type strain is L10.10 T (LMG 29628 T , DSM 101070 T ). Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Biodegradation of resorcinol byPseudomonas sp.

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

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

  18. Computer-aided tool for solvent selection in pharmaceutical processes: Solvent swap

    DEFF Research Database (Denmark)

    Papadakis, Emmanouil; K. Tula, Anjan; Gernaey, Krist V.

    -liquid equilibria). The application of the developed model-based framework is highlighted through several cases studies published in the literature. In the current state, the framework is suitable for problems where the original solvent is exchanged by distillation. A solvent selection guide for fast of suitable......-aided framework with the objective to assist the pharmaceutical industry in gaining better process understanding. A software interface to improve the usability of the tool has been created also....

  19. Uji produksi biosurfaktan oleh Pseudomonas sp. pada substrat yang berbeda

    Directory of Open Access Journals (Sweden)

    Fatimah Fatimah

    2012-02-01

    Full Text Available Biosurfactant, microbial metabolite whose properties like surfactant, was suggested to replace chemically synthesized surfactant for take in hand environtmental pollution by petroleum hydrocarbon. This work was done to examine potency of Pseudomonas sp. isolated from Tanjung Perak Harbor to produce biosurfactant. Also, to know the effect of different substrates (glucose + yeast extract, lubricating oil and hexadecane toward biosurfactant production. Pseudomonas sp. grown in mineral synthetic water and biosurfactant production was measured on stationary phase. Biosurfactant production based on emulsification activity and surface tension reduction of supernatant (using Du Nouy tensiometer. Solar, lubricating oil, and hexadecane were used to examine emulsification activity. Results indicated that Pseudomonas sp. have a potency to produce biosurfactant. Surface tension of supernatant decreased up to 20 dyne/cm, when grown on hexadecane substrate. Hexadecane is the best growing substrate for biosurfactant production than others.

  20. Effects of solvent evaporation conditions on solvent vapor annealed cylinder-forming block polymer thin films

    Science.gov (United States)

    Grant, Meagan; Jakubowski, William; Nelson, Gunnar; Drapes, Chloe; Baruth, A.

    Solvent vapor annealing is a less time and energy intensive method compared to thermal annealing, to direct the self-assembly of block polymer thin films. Periodic nanostructures have applications in ultrafiltration, magnetic arrays, or other structures with nanometer dimensions, driving its continued interest. Our goal is to create thin films with hexagonally packed, perpendicular aligned cylinders of poly(lactide) in a poly(styrene) matrix that span the thickness of the film with low anneal times and low defect densities, all with high reproducibility, where the latter is paramount. Through the use of our computer-controlled, pneumatically-actuated, purpose-built solvent vapor annealing chamber, we have the ability to monitor and control vapor pressure, solvent concentration within the film, and solvent evaporation rate with unprecedented precision and reliability. Focusing on evaporation, we report on two previously unexplored areas, chamber pressure during solvent evaporation and the flow rate of purging gas aiding the evaporation. We will report our exhaustive results following atomic force microscopy analysis of films exposed to a wide range of pressures and flow rates. Reliably achieving well-ordered films, while occurring within a large section of this parameter space, was correlated with high-flow evaporation rates and low chamber pressures. These results have significant implications on other methods of solvent annealing, including ``jar'' techniques.

  1. Bioleaching of copper oxide ore by Pseudomonas aeruginosa

    Science.gov (United States)

    Shabani, M. A.; Irannajad, M.; Azadmehr, A. R.; Meshkini, M.

    2013-12-01

    Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53% of copper was extracted.

  2. On linear correlation between interfacial tension of water-solvent interface solubility of water in organic solvents and parameters of diluent effect scale

    International Nuclear Information System (INIS)

    Mezhov, Eh.A.; Khananashvili, N.L.; Shmidt, V.S.

    1988-01-01

    Presence of linear correlation between water solubility in nonmiscible with it organic solvents, interfacial tension of water-solvent interface, on the one hand, and solvent effect scale parameters and these solvents π* - on the other hand, is established. It allows, using certain tabular parameters of solvent effect or each solvent π*, to predict values of interfacial tension and water solubility for corresponding systems. It is shown, that solvent effect scale allows to predict values more accurately, than other known solvent scales, as it in contrast to other scales characterizes solvents, which are in equilibrium with water

  3. Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

    Energy Technology Data Exchange (ETDEWEB)

    Saini, R.K.; Das, K., E-mail: kaustuv@rrcat.gov.in

    2014-01-15

    Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step.

  4. Photophysics of Curcumin excited state in toluene-polar solvent mixtures: Role of H-bonding properties of the polar solvent

    International Nuclear Information System (INIS)

    Saini, R.K.; Das, K.

    2014-01-01

    Excited state dynamics of Curcumin in binary solvent mixtures of toluene and polar H-bonding solvents were compared by using an instrument endowed with 40 ps time resolution. The solvation time constant of Curcumin increases significantly (and can therefore be measured) in polar solvents which have, either, both H-bond donating and accepting ability, or, only H-bond donating ability. These results suggest that the rate limiting step in the excited state dynamics of the pigment might be the formation and reorganization of the intermolecular H-bonding between the keto group of the pigment and the H-bond donating moieties of the polar solvent. -- Highlights: • Excited state dynamics of Curcumin in a binary solvent mixture of toluene and three polar H-bonding solvents were compared. • The solvation time constant increases significantly with polar solvents having, H-bond donating and accepting, or, H-bond donating ability. • Observed results suggest that H-bonding property of polar solvent plays an important role in the excited state dynamics. • Intermolecular H-bonding between the keto group of the pigment and polar solvent may be the rate limiting step

  5. Potencial de pseudomonas spp. fluorescentes para biocontrole de alternaria ricini em mamoneira Potential of fluorescent pseudomonas spp. For biological control of alternaria ricini on castorbean

    Directory of Open Access Journals (Sweden)

    Francisco de A.G. da Silva

    1998-06-01

    Full Text Available The potential of fluorescent Pseudomonas spp. to control Alternaria leaf spot on castorbean, caused by Alternaria ricini, was studied under greenhouse conditions. Two periods for antagonist applications were tested: 48h before and simultaneously to the pathogen inoculation. Among the antagonists tested JA4 and BJ22 were the most effectives showing disease severity reduction of 20.9% and 17.8% respectively, when applied simultaneously. The effect of Pseudomonas spp. on the micelial growth and sporulation was also studied throughout three different methods (funel, streak and celophane. Inhibition of micelial growth and sporulation was observed. There was no correlation between in vitro and in vivo data. Antibiosis was showed as a mode of action for Pseudomonas spp. in relation to Alternaria ricini. Ultrastructural studies confirmed the inhibition of spore germination by the bacteria.

  6. Linear correlation of interfacial tension at water-solvent interface, solubility of water in organic solvents, and SE* scale parameters

    International Nuclear Information System (INIS)

    Mezhov, E.A.; Khananashvili, N.L.; Shmidt, V.S.

    1988-01-01

    A linear correlation has been established between the solubility of water in water-immiscible organic solvents and the interfacial tension at the water-solvent interface on the one hand and the parameters of the SE* and π* scales for these solvents on the other hand. This allows us, using the known tabulated SE* or π* parameters for each solvent, to predict the values of the interfacial tension and the solubility of water for the corresponding systems. We have shown that the SE* scale allows us to predict these values more accurately than other known solvent scales, since in contrast to other scales it characterizes solvents found in equilibrium with water

  7. Environmental stress speeds up DNA replication in Pseudomonas putida in chemostat cultivations.

    Science.gov (United States)

    Lieder, Sarah; Jahn, Michael; Koepff, Joachim; Müller, Susann; Takors, Ralf

    2016-01-01

    Cellular response to different types of stress is the hallmark of the cell's strategy for survival. How organisms adjust their cell cycle dynamics to compensate for changes in environmental conditions is an important unanswered question in bacterial physiology. A cell using binary fission for reproduction passes through three stages during its cell cycle: a stage from cell birth to initiation of replication, a DNA replication phase and a period of cell division. We present a detailed analysis of durations of cell cycle phases, investigating their dynamics under environmental stress conditions. Applying continuous steady state cultivations (chemostats), the DNA content of a Pseudomonas putida KT2440 population was quantified with flow cytometry at distinct growth rates. Data-driven modeling revealed that under stress conditions, such as oxygen deprivation, solvent exposure and decreased iron availability, DNA replication was accelerated correlated to the severity of the imposed stress (up to 1.9-fold). Cells maintained constant growth rates by balancing the shortened replication phase with extended cell cycle phases before and after replication. Transcriptome data underpin the transcriptional upregulation of crucial genes of the replication machinery. Hence adaption of DNA replication speed appears to be an important strategy to withstand environmental stress. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. 29 CFR 1915.32 - Toxic cleaning solvents.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Toxic cleaning solvents. 1915.32 Section 1915.32 Labor... Preservation § 1915.32 Toxic cleaning solvents. (a) When toxic solvents are used, the employer shall employ one or more of the following measures to safeguard the health of employees exposed to these solvents. (1...

  9. Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.Y.; Feng, J.; Xie, K.C.; Kandiyoti, R. [Taiyuan University of Technology, Taiyuan (China)

    2005-08-01

    Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350 {sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

  10. Analysis of recovered solvents from coal liquefaction in a flowing-solvent reactor by SEC and UV-fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Wen-Ying Li; Jie Feng; Ke-Chang Xie; R. Kandiyoti [Taiyuan University of Technology, Taiyuan (China). Key Laboratory of Coal Science and Technology for Ministry of Education and Shanxi Province

    2005-08-01

    Point of Ayr coal has been extracted using three solvents: tetralin, quinoline and 1-methyl-2-pyrrolidinone (NMP); at two temperatures: 350{sup o}C and 450{sup o}C, corresponding approximately to before and after the onset of massive covalent bond scission by pyrolysis. These solvents differ in solvent power and the ability to donate hydrogen atoms to stabilize free radicals produced by pyrolysis of the coal. Analysis of the fresh solvents and recovered solvents from coal liquefaction was achieved by size exclusion chromatography and UV-fluorescence spectroscopy. In the blank run, it was testified that the filling material sand and the steel powder did not react with solvent with increasing reaction temperature. The role of hydrogen donation in the tetralin extracts was to increase the proportion of large molecules with increasing extraction temperature. Quinoline and NMP both have the powerful extracting capability to get more materials out of coal with increasing extraction temperature.

  11. A case of orbital apex syndrome due to Pseudomonas aeruginosa infection

    Directory of Open Access Journals (Sweden)

    Takeshi Kusunoki

    2011-11-01

    Full Text Available Orbital apex syndrome is commonly been thought to have a poor prognosis. Many cases of this syndrome have been reported to be caused by paranasal sinus mycosis. We encountered a very rare case (60-year-old woman of sinusitis with orbital apex syndrome due to Pseudomonas aeruginosa infection. She had received insulin and dialysis for diabtes and diabetic nephropathy, moreover anticoagulants after heart by-pass surgery. She underwent endoscopic sinus operation and was treated with antibiotics, but her loss of left vision did not improve. Recently, sinusitis cases due to Pseudomonas aeruginosa were reported to be a increasing. Therefore, we should consider the possibility of Pseudomonas aeruginosa as well as mycosis as infections of the sinus, especially inpatients who are immunocompromised body.

  12. Decaffeination process characteristic of Robusta coffee in single column reactor using ethyl acetate solvent

    Directory of Open Access Journals (Sweden)

    Sukrisno Widyotomo

    2009-08-01

    Full Text Available Consumers drink coffee not as nutrition source, but as refreshment drink. For coffee consumers who have high tolerance for caffeine, coffee may warm up and refresh their bodies. High caffeine content in coffee beans may cause several complaints to consumers who are susceptible to caffeine. One of the efforts, for coffee market expansion is product diversification to decaffeinated coffee. Decaffeination process is one of process to reduce caffeine content from agricultural products. Indonesian Coffee and Cocoa Research Institute in collaboration with Bogor Agricultural University has developed a single column reactor for coffee beans decaffeination. The aim of this research is to study process characteristic of coffee decaffeination in single column reactor using ethyl acetate (C4H8O2 solvent. Treatments applicated in the research were time and temperature process. Temperature treatment were 50—60OC, 60—70OC, 70—80OC, 80—90OC and 90—100OC. Time treatment were 2 h, 4 h, 6 h, 8 h, 10 h, and 12 h Size of Robusta coffee beans used were less than 5.5 mm (A4, between 5.5 mm and 6.5 mm (A3, between 6.5 mm and 7.5 mm (A2, and more than 7.5 mm (A1. The result showed that decaffeination process with ethyl acetate solvent will be faster when its temperature was higher and smaller bean size. For bean size less than 5,5 mm, decaffeination process by 10% ethyl acetat can be done 8—10 hours in 90—100OC solvent temperature or 12 hours in 60—70OC solvent temperature for 0.3% caffein content. Organoleptic test showed that 90—100OC temperature solvent treatment decreased coffee flavor, which aroma, bitterness and body values were 1.9 each . Key words : Coffee, caffeine, decaffeination, quality, single column.

  13. Pseudomonas salina sp. nov., isolated from a salt lake.

    Science.gov (United States)

    Zhong, Zhi-Ping; Liu, Ying; Hou, Ting-Ting; Liu, Hong-Can; Zhou, Yu-Guang; Wang, Fang; Liu, Zhi-Pei

    2015-09-01

    A Gram-staining-negative, facultatively aerobic bacterium, strain XCD-X85(T), was isolated from Xiaochaidan Lake, a salt lake (salinity 9.9%, w/v) in Qaidam basin, Qinghai province, China. Its taxonomic position was determined by using a polyphasic approach. Cells of strain XCD-X85(T) were non-endospore-forming rods, 0.4-0.6 μm wide and 1.0-1.6 μm long, and motile by means of a single polar flagellum. Strain XCD-X85(T) was catalase- and oxidase-positive. Growth was observed in the presence of 0-12.0% (w/v) NaCl (optimum, 1.0-2.0%) and at 4-35 °C (optimum, 25-30 °C) and pH 6.5-10.5 (optimum, pH 8.0-8.5). Strain XCD-X85(T) contained (>10%) summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C12 : 0, C16 : 0 and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) as the predominant fatty acids. The major respiratory quinone was ubiquinone 9 (Q-9). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The DNA G+C content was 57.4 mol%. Phylogenetic trees based on 16S rRNA gene sequences showed that strain XCD-X85(T) was associated with the genus Pseudomonas, and showed highest 16S rRNA gene sequence similarities to Pseudomonas pelagia CL-AP6(T) (99.0%) and Pseudomonas bauzanensis BZ93(T) (96.8%). DNA-DNA relatedness of strain XCD-X85T to P. pelagia JCM 15562(T) was 19 ± 1%. On the basis of the data presented above, it is concluded that strain XCD-X85(T) represents a novel species of the genus Pseudomonas, for which the name Pseudomonas salina sp. nov. is proposed. The type strain is XCD-X85(T) ( = CGMCC 1.12482(T) = JCM 19469(T)).

  14. Organic solvent topical report

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    1999-01-01

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed

  15. Organic solvent topical report

    Energy Technology Data Exchange (ETDEWEB)

    COWLEY, W.L.

    1999-05-13

    This report provides the basis for closing the organic solvent safety issue. Sufficient information is presented to conclude that risk posed by an organic solvent fire is within risk evaluation guidelines. This report updates information contained in Analysis of Consequences of Postulated Solvent Fires in Hanford Site Waste Tanks. WHC-SD-WM-CN-032. Rev. 0A (Cowley et al. 1996). However, this document will not replace Cowley et al (1996) as the primary reference for the Basis for Interim Operation (BIO) until the recently submitted BIO amendment (Hanson 1999) is approved by the US Department of Energy. This conclusion depends on the use of controls for preventing vehicle fuel fires and for limiting the use of flame cutting in areas where hot metal can fall on the waste surface.The required controls are given in the Tank Waste Remediation System Technical Safety Requirements (Noorani 1997b). This is a significant change from the conclusions presented in Revision 0 of this report. Revision 0 of this calcnote concluded that some organic solvent fire scenarios exceeded risk evaluation guidelines, even with controls imposed.

  16. Overexpression, crystallization and preliminary X-ray crystallographic analysis of erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa.

    Science.gov (United States)

    Ha, Jun Yong; Lee, Ji Hyun; Kim, Kyoung Hoon; Kim, Do Jin; Lee, Hyung Ho; Kim, Hye-Kyung; Yoon, Hye-Jin; Suh, Se Won

    2006-02-01

    The enzyme erythronate-4-phosphate dehydrogenase catalyses the conversion of erythronate-4-phosphate to 3-hydroxy-4-phospho-hydroxy-alpha-ketobutyrate. It belongs to the D-isomer-specific 2-hydroxyacid dehydrogenase family. It is essential for de novo biosynthesis of vitamin B6 (pyridoxine). Erythronate-4-phosphate dehydrogenase from Pseudomonas aeruginosa, a homodimeric enzyme consisting of two identical 380-residue subunits, has been overexpressed in Escherichia coli with a C-terminal purification tag and crystallized at 297 K using 0.7 M ammonium dihydrogen phosphate, 0.4 M ammonium tartrate, 0.1 M sodium citrate pH 5.6 and 10 mM cupric chloride. X-ray diffraction data were collected to 2.20 A from a crystal grown in the presence of NADH. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 84.77, b = 101.28, c = 142.58 A. A dimeric molecule is present in the asymmetric unit, giving a crystal volume per protein weight (VM) of 3.64 A3 Da(-1) and a solvent content of 66%.

  17. Accelerated storage testing of freeze-dried Pseudomonas ...

    African Journals Online (AJOL)

    Accelerated storage testing of freeze-dried Pseudomonas fluorescens BTP1, ... of all P. fluorescens strains were not significantly different and thermal inactivation ... useful to the development of improved reference materials and samples held ...

  18. Identification of a haloalkaliphilic and thermostable cellulase with improved ionic liquid tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tao; Datta, Supratim; Eichler, Jerry; Ivanova, Natalia; Axen, Seth D.; Kerfeld, Cheryl A.; Chen, Feng; Kyrpides, Nikos; Hugenholtz, Philip; Cheng, Jan-Fang; Sale, Kenneth L.; Simmons, Blake; Rubin, Eddy

    2011-02-17

    Some ionic liquids (ILs) have been shown to be very effective solvents for biomass pretreatment. It is known that some ILs can have a strong inhibitory effect on fungal cellulases, making the digestion of cellulose inefficient in the presence of ILs. The identification of IL-tolerant enzymes that could be produced as a cellulase cocktail would reduce the costs and water use requirements of the IL pretreatment process. Due to their adaptation to high salinity environments, halophilic enzymes are hypothesized to be good candidates for screening and identifying IL-resistant cellulases. Using a genome-based approach, we have identified and characterized a halophilic cellulase (Hu-CBH1) from the halophilic archaeon, Halorhabdus utahensis. Hu-CBH1 is present in a gene cluster containing multiple putative cellulolytic enzymes. Sequence and theoretical structure analysis indicate that Hu-CBH1 is highly enriched with negatively charged acidic amino acids on the surface, which may form a solvation shell that may stabilize the enzyme, through interaction with salt ions and/or water molecules. Hu-CBH1 is a heat tolerant haloalkaliphilic cellulase and is active in salt concentrations up to 5 M NaCl. In high salt buffer, Hu-CBH1 can tolerate alkali (pH 11.5) conditions and, more importantly, is tolerant to high levels (20percent w/w) of ILs, including 1-allyl-3-methylimidazolium chloride ([Amim]Cl). Interestingly, the tolerances to heat, alkali and ILs are found to be salt-dependent, suggesting that the enzyme is stabilized by the presence of salt. Our results indicate that halophilic enzymes are good candidates for the screening of IL-tolerant cellulolytic enzymes.

  19. Tolerance and sensitization to inhaled 1,1,1-trichloroethane in mice: results from open-field behavior and a functional observational battery.

    Science.gov (United States)

    Bowen, Scott E; Balster, Robert L

    2006-05-01

    1,1,1-Trichloroethane (TCE), a representative abused solvent, has well described acute behavioral effects in animals. Much less is known about repeated high-concentration exposures as would be encountered in inhalant abusers. Tolerance has been demonstrated in some, but not all, studies with TCE while sensitization has also been seen with other abused solvents. The present study was designed to further characterize changes in the effects of repeated exposure to TCE on a variety of mouse behaviors. Mice were tested using locomotor activity as well as a functional observational battery (FOB) both before and after a regimen of daily exposures to various concentrations of TCE. The initial locomotor effects of acute 30-min exposures to TCE were biphasic with concentration-dependent increases in activity at lower concentrations and decreases observed at higher concentrations. The profile of acute effects as measured by the FOB included changes in posture, decreased arousal, disturbances in gait, delayed righting reflexes, and decreased sensorimotor reactivity. Animals were then divided into five groups and exposed 30 min/day to either air or one of four concentrations of TCE (2,000, 6,000, 10,000, or 13,300 ppm) for 15 consecutive days. The TCE concentration used primarily affected the magnitude of change, not whether tolerance or sensitization occurred. Tolerance developed on the measures of forelimb grip strength, inverted screen, and number of rears. Conversely, sensitization developed to measures of locomotor activity. Depending on the behavioral measure, both tolerance and sensitization can occur in mice with repeated exposure to TCE. Both of these phenomena are characteristic of drugs of abuse.

  20. Implicit solvent simulations of DNA and DNA-protein complexes: Agreement with explicit solvent vs experiment

    Czech Academy of Sciences Publication Activity Database

    Chocholoušová, Jana; Feig, M.

    2006-01-01

    Roč. 110, č. 34 (2006), s. 17240-17251 ISSN 1520-6106 Keywords : implicit solvent * explicit solvent * protein DNA complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.115, year: 2006

  1. Biomolecular-solvent stereodynamic coupling probed by deuteration

    International Nuclear Information System (INIS)

    Fornili, S.L.; Leone, M.; Madonia, F.; Migliore, M.; Palma-Vittorelli, M.B.; Palma, M.U.; San Biagio, P.L.

    1983-01-01

    Thermodynamic interpretation of experiments with isotopically perturbed solvent supports the view that solvent stereodynamics is directly relevant to thermodynamic stability of biomolecules. According with the current understanding of the structure of the aqueous solvent, in any stereodynamic configuration of the latter, connectivity pathways are identifiable for their topologic and order properties. Perturbing the solvent by isotopic substitution or, e.g., by addition of co-solvents, can therefore be viewed as reinforcing or otherwise perturbing these topologic structures. This microscopic model readily visualizes thermodynamic interpretation. In conclusion, the topologic stereodynamic structures of connectivity pathways in the solvent, as modified by interaction with solutes, acquire a specific thermodynamic and biological significance, and the problem of thermodynamic and functional stability of biomolecules is seen in its full pertinent phase space

  2. Tolerance

    DEFF Research Database (Denmark)

    Tønder, Lars

    is linked to a different set of circumstances than the ones suggested by existing models in contemporary democratic theory. Reorienting the discussion of tolerance, the book raises the question of how to disclose new possibilities within our given context of affect and perception. Once we move away from......Tolerance: A Sensorial Orientation to Politics is an experiment in re-orientation. The book is based on the wager that tolerance exceeds the more prevalent images of self-restraint and repressive benevolence because neither precludes the possibility of a more “active tolerance” motivated...... by the desire to experiment and to become otherwise. The objective is to discuss what gets lost, conceptually as well as politically, when we neglect the subsistence of active tolerance within other practices of tolerance, and to develop a theory of active tolerance in which tolerance's mobilizing character...

  3. Investigating the compatibility of the biocontrol agent Clonostachys rosea IK726 with prodigiosin-producing Serratia rubidaea S55 and phenazine-producing Pseudomonas chlororaphis ToZa7.

    Science.gov (United States)

    Kamou, Nathalie N; Dubey, Mukesh; Tzelepis, Georgios; Menexes, Georgios; Papadakis, Emmanouil N; Karlsson, Magnus; Lagopodi, Anastasia L; Jensen, Dan Funck

    2016-05-01

    This study was carried out to assess the compatibility of the biocontrol fungus Clonostachys rosea IK726 with the phenazine-producing Pseudomonas chlororaphis ToZa7 or with the prodigiosin-producing Serratia rubidaea S55 against Fusarium oxysporum f. sp. radicis-lycopersici. The pathogen was inhibited by both strains in vitro, whereas C. rosea displayed high tolerance to S. rubidaea but not to P. chlororaphis. We hypothesized that this could be attributed to the ATP-binding cassette (ABC) proteins. The results of the reverse transcription quantitative PCR showed an induction of seven genes (abcB1, abcB20, abcB26, abcC12, abcC12, abcG8 and abcG25) from subfamilies B, C and G. In planta experiments showed a significant reduction in foot and root rot on tomato plants inoculated with C. rosea and P. chlororaphis. This study demonstrates the potential for combining different biocontrol agents and suggests an involvement of ABC transporters in secondary metabolite tolerance in C. rosea.

  4. Shape Engineering of Biomass-Derived Nanoparticles from Hollow Spheres to Bowls via Solvent-Induced Buckling.

    Science.gov (United States)

    Chen, Chunhong; Li, Xuefeng; Jiang, Deng; Wang, Zhe; Wang, Yong

    2018-06-19

    To realize the asymmetry for the hollow carbonaceous nanostructures remains to be a great challenge, especially when biomass is chosen as the carbon resource via hydrothermal carbonization (HTC). Herein, a simple and straightforward solvent induced buckling strategy is demonstrated for the synthesis of asymmetric spherical and bowllike carbonaceous nanomaterials. The formation of the bowllike morphology was attributed to the buckling of the spherical shells induced by the dissolution of the oligomers. The bowllike particles made by this solvent-driven approach demonstrated a well-controlled morphology and a uniform particle size of ~360 nm. The obtained nanospheres and nanobowls can be loaded with CoS2 nanoparticles to act as novel heterogeneous catalysts for the selective hydrogenation of aromatic nitro compounds. With the bowllike structure in hand, as expected, the CoS2/nanobowls catalyst showed good tolerance to a wide scope of reducible groups and afforded both high activity and selectivity in almost all the tested substrates (14). © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Nitrogen contribution proportion from soil, fertilizer and pseudomonas putida like in sorghum plantation on South Sumatra's inceptisols; Proposi Sumbangan Nitrogen Oleh Tanah, Pupuk Dan Pseudomonas putida like Dalam Tanaman Sorghum Pada Inceptisol Sumatera Selatan

    Energy Technology Data Exchange (ETDEWEB)

    Kesumadewi, A A.I. [Departement Agriculture Udayana, Bali (Indonesia); Anas, Iswandi; Santosa, D A [Departement Agriculture, Bogor Agriculture Institute (Indonesia); Sisworo, Elsje L [Center for Application of Isotop and Radiation, National Nuclear Energy Agency, Jakarta (Indonesia)

    2000-02-23

    The proportion of N which absorbed either from natural source (soil), N-fertilizer or N sub.2-fixing microorganism on sorghum plantation in marginal alang-alang lands that group to inceptisol should be studied in securing the soil fertility. In this experiment, N contribution of those N sources was determined during vegetative stage of sorghum on three subgroup of south sumatera's inceptisols. A greenhouse experiment that arranged in randomized complete block design using 2 factorial split plot was carried out in IPB Bogor from May-December 1998. The observation was focused on partition of N contribution from the soil, N-fertilizer and Pseudomonas putida like(N sub.2-fixing microorganism) on total plant-content 4 and 8 weeks after plantations (WAP). N-partition from those N-sources was done based o A-value method. Sorghum was absorb larger proportion of N from soil(63,36%-48,83% on 4 WAP and 64,58 % on WAP) than from fertilizer and P.putida like on all of the soil subgroups. Soil-N absorption was highest on oxic dystropept. Pseudomonas putida like was not able to subtite soil-N and fertilizer-N in sufficient amount to vigorous plant growth particularly on typica humitropept and typic dystropept. The microorganism was only provide a small amount of N to sorghum on oxic dystropept (23,05-23,95 % on 4 WAP and 15,91-34,44 % on 8WAP). The increment of plant root surface area could be enhance in greater extent of plant-N absorption than N sub.2-fixation. Thus, plantation of marginal tolerant sorghum still need addition of N-fertilizer.

  6. Pseudomonas sax genes overcome aliphatic isothiocyanate-mediated non-host resistance in Arabidopsis

    Science.gov (United States)

    Jun Fan; Casey Crooks; Gary Creissen; Lionel Hill; Shirley Fairhurst; Peter Doerner; Chris Lamb

    2011-01-01

    Most plant-microbe interactions do not result in disease; natural products restrict non-host pathogens. We found that sulforaphane (4-methylsulfinylbutyl isothiocyanate), a natural product derived from aliphatic glucosinolates, inhibits growth in Arabidopsis of non-host Pseudomonas bacteria in planta. Multiple sax genes (saxCAB/F/D/G) were identified in Pseudomonas...

  7. Structural transition of a homopolymer in solvents mixture

    International Nuclear Information System (INIS)

    Guettari, Moez; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh

    2008-01-01

    The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M w = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X A is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X A = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture

  8. Pseudomonas oceani sp. nov., isolated from deep seawater.

    Science.gov (United States)

    Wang, Ming-Qing; Sun, Li

    2016-10-01

    In this study, we identified a novel Gram-stain-negative, aerobic, motile, and rod-shaped bacterium, strain KX 20T, isolated from the deep seawater in Okinawa Trough, northwestern Pacific Ocean. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain KX 20T was related to members of the genus Pseudomonas and shares the highest sequence identities with Pseudomonas aestusnigri CECT 8317T (99.4 %) and Pseudomonas pachastrellae JCM 12285T (98.5 %). The 16S rRNA gene sequence identities between strain KX 20T and other members of the genus Pseudomonaswere below 96.6 %. The gyrB and rpoD genes of strain KX 20T shared 82.0 to 89.3 % sequence identity with the gyrB and rpoD genes of the closest phylogenetic neighbours of KX 20T. The predominant cellular fatty acids of strain KX 20T were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) (29.2 %), C16 : 0 (24.5 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) (21.5 %) and C12 : 0 (8.2 %). The major polar lipids of strain KX 20T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and unknown phospholipids. The genomic DNA G+C content of strain KX 20T was 62.9 mol%. On the basis of phylogenetic analysis and phenotypic characteristics, a novel species, Pseudomonas oceani sp. nov. is proposed. The type strain is KX 20T (=CGMCC 1.15195T=DSM 100277T).

  9. Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

    International Nuclear Information System (INIS)

    Asim, Sadia; Mansha, Asim; Grampp, Günter; Landgraf, Stephan; Zahid, Muhammad; Bhatti, Ijaz Ahmad

    2014-01-01

    Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε s ≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv 0 / ), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν ν ) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G ET = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair or solvent separated

  10. PseudoMLSA: a database for multigenic sequence analysis of Pseudomonas species

    Directory of Open Access Journals (Sweden)

    Lalucat Jorge

    2010-04-01

    Full Text Available Abstract Background The genus Pseudomonas comprises more than 100 species of environmental, clinical, agricultural, and biotechnological interest. Although, the recommended method for discriminating bacterial species is DNA-DNA hybridisation, alternative techniques based on multigenic sequence analysis are becoming a common practice in bacterial species discrimination studies. Since there is not a general criterion for determining which genes are more useful for species resolution; the number of strains and genes analysed is increasing continuously. As a result, sequences of different genes are dispersed throughout several databases. This sequence information needs to be collected in a common database, in order to be useful for future identification-based projects. Description The PseudoMLSA Database is a comprehensive database of multiple gene sequences from strains of Pseudomonas species. The core of the database is composed of selected gene sequences from all Pseudomonas type strains validly assigned to the genus through 2008. The database is aimed to be useful for MultiLocus Sequence Analysis (MLSA procedures, for the identification and characterisation of any Pseudomonas bacterial isolate. The sequences are available for download via a direct connection to the National Center for Biotechnology Information (NCBI. Additionally, the database includes an online BLAST interface for flexible nucleotide queries and similarity searches with the user's datasets, and provides a user-friendly output for easily parsing, navigating, and analysing BLAST results. Conclusions The PseudoMLSA database amasses strains and sequence information of validly described Pseudomonas species, and allows free querying of the database via a user-friendly, web-based interface available at http://www.uib.es/microbiologiaBD/Welcome.html. The web-based platform enables easy retrieval at strain or gene sequence information level; including references to published peer

  11. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Science.gov (United States)

    Molina-Romero, Dalia; Baez, Antonino; Quintero-Hernández, Verónica; Castañeda-Lucio, Miguel; Fuentes-Ramírez, Luis Ernesto; Bustillos-Cristales, María Del Rocío; Rodríguez-Andrade, Osvaldo; Morales-García, Yolanda Elizabeth; Munive, Antonio; Muñoz-Rojas, Jesús

    2017-01-01

    Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440) and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02) strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  12. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Directory of Open Access Journals (Sweden)

    Dalia Molina-Romero

    Full Text Available Plant growth-promoting rhizobacteria (PGPR increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440 and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02 strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  13. Aminosilicone solvent recovery methods and systems

    Science.gov (United States)

    Spiry, Irina Pavlovna; Perry, Robert James; Wood, Benjamin Rue; Singh, Surinder Prabhjot; Farnum, Rachel Lizabeth; Genovese, Sarah Elizabeth

    2018-02-13

    The present invention is directed to aminosilicone solvent recovery methods and systems. The methods and systems disclosed herein may be used to recover aminosilicone solvent from a carbon dioxide containing vapor stream, for example, a vapor stream that leaves an aminosilicone solvent desorber apparatus. The methods and systems of the invention utilize a first condensation process at a temperature from about 80.degree. C. to about 150.degree. C. and a second condensation process at a temperature from about 5.degree. C. to about 75.degree. C. The first condensation process yields recovered aminosilicone solvent. The second condensation process yields water.

  14. Work ability score of solvent-exposed workers.

    Science.gov (United States)

    Furu, Heidi; Sainio, Markku; Hyvärinen, Hanna-Kaisa; Kaukiainen, Ari

    2018-03-28

    Occupational chronic solvent encephalopathy (CSE), characterized by neurocognitive dysfunction, often leads to early retirement. However, only the more severe cases are diagnosed with CSE, and little is known about the work ability of solvent-exposed workers in general. The aim was to study memory and concentration symptoms, work ability and the effect of both solvent-related and non-occupational factors on work ability, in an actively working solvent-exposed population. A questionnaire on exposure and health was sent to 3640 workers in four solvent-exposed fields, i.e. painters and floor-layers, boat builders, printers, and metal workers. The total number of responses was 1730. We determined the work ability score (WAS), a single question item of the Work Ability Index, and studied solvent exposure, demographic factors, Euroquest memory and concentration symptoms, chronic diseases, and employment status using univariate and multivariate analyses. The findings were compared to those of a corresponding national blue-collar reference population (n = 221), and a small cohort of workers with CSE (n = 18). The proportion of workers with memory and concentration symptoms was significantly associated with solvent exposure. The WAS of solvent-exposed workers was lower than that of the national blue-collar reference group, and the difference was significant in the oldest age group (those aged over 60). Solvent-exposed worker's WAS were higher than those of workers diagnosed with CSE. The WAS were lowest among painters and floor-layers, followed by metal workers and printers, and highest among boat builders. The strongest explanatory factors for poor work ability were the number of chronic diseases, age and employment status. Solvent exposure was a weak independent risk factor for reduced WAS, comparable to a level of high alcohol consumption. Even if memory and concentration symptoms were associated with higher solvent exposure, the effect of solvents on self

  15. Peritoneal dialysis-related peritonitis caused by Pseudomonas species: Insight from a post-millennial case series.

    Science.gov (United States)

    Lu, Wanhong; Kwan, Bonnie Ching-Ha; Chow, Kai Ming; Pang, Wing-Fai; Leung, Chi Bon; Li, Philip Kam-To; Szeto, Cheuk Chun

    2018-01-01

    Pseudomonas peritonitis is a serious complication of peritoneal dialysis (PD). However, the clinical course of Pseudomonas peritonitis following the adoption of international guidelines remains unclear. We reviewed the clinical course and treatment response of 153 consecutive episodes of PD peritonitis caused by Pseudomonas species from 2001 to 2015. Pseudomonas peritonitis accounted for 8.3% of all peritonitis episodes. The bacteria isolated were resistant to ceftazidime in 32 cases (20.9%), and to gentamycin in 18 cases (11.8%). In 20 episodes (13.1%), there was a concomitant exit site infection (ESI); in another 24 episodes (15.7%), there was a history of Pseudomonas ESI in the past. The overall primary response rate was 53.6%, and complete cure rate 42.4%. There was no significant difference in the complete cure rate between patients who treated with regimens of 3 and 2 antibiotics. Amongst 76 episodes (46.4%) that failed to respond to antibiotics by day 4, 37 had immediate catheter removal; the other 24 received salvage antibiotics, but only 6 achieved complete cure. Antibiotic resistance is common amongst Pseudomonas species causing peritonitis. Adoption of the treatment guideline leads to a reasonable complete cure rate of Pseudomonas peritonitis. Treatment with three antibiotics is not superior than the conventional two antibiotics regimen. When there is no clinical response after 4 days of antibiotic treatment, early catheter removal should be preferred over an attempt of salvage antibiotic therapy.

  16. Differential sensitivity of polyhydroxyalkanoate producing bacteria to fermentation inhibitors and comparison of polyhydroxybutyrate production from Burkholderia cepacia and Pseudomonas pseudoflava.

    Science.gov (United States)

    Dietrich, Diane; Illman, Barbara; Crooks, Casey

    2013-06-04

    The aim of this study is determine the relative sensitivity of a panel of seven polyhydroxyalkanoate producing bacteria to a panel of seven lignocellulosic-derived fermentation inhibitors representing aliphatic acids, furans and phenolics. A further aim was to measure the polyhydroxybutyrate production of select organisms on lignocellulosic-derived monosaccharides arabinose, xylose, glucose and mannose. We examined the sensitivity of seven polyhydroxyalkanoate producing bacteria: Azohydromonas lata, Bacillus megaterium, Bacillus cereus, Burkholderia cepacia, Pseudomonas olevorans, Pseudomonas pseudoflava and Ralstonia eutropha, against seven fermentation inhibitors produced by the saccharification of lignocellulose: acetic acid, levulinic acid, coumaric acid, ferulic acid, syringaldehyde, furfural, and hyroxymethyfurfural. There was significant variation in the sensitivity of these microbes to representative phenolics ranging from 0.25-1.5 g/L coumaric and ferulic acid and between 0.5-6.0 g/L syringaldehyde. Inhibition ranged from 0.37-4 g/L and 0.75-6 g/L with acetic acid and levulinic acid, respectively. B. cepacia and P. pseudoflava were selected for further analysis of polyhydroxyalkanoate production. We find significant differences in sensitivity to the fermentation inhibitors tested and find these variations to be over a relevant concentration range given the concentrations of inhibitors typically found in lignocellulosic hydrolysates. Of the seven bacteria tested, B. cepacia demonstrated the greatest inhibitor tolerance. Similarly, of two organisms examined for polyhydroxybutyrate production, B. cepacia was notably more efficient when fermenting pentose substrates.

  17. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    International Nuclear Information System (INIS)

    Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

    2015-01-01

    CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

  18. Structural transition of a homopolymer in solvents mixture

    Energy Technology Data Exchange (ETDEWEB)

    Guettari, Moez [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)], E-mail: gtarimoez@yahoo.fr; Aschi, Adel; Gomati, Riadh; Gharbi, Abdelhafidh [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 Tunisia (Tunisia)

    2008-07-01

    The present work is aimed at studying the thermodynamic behaviour of a polymer in solvents mixture. Dynamic light scattering is used to measure the hydrodynamic radius of polyvinylpyrrolidone (M{sub w} = 360,000 g/mol), in water/methanol solvents mixture, versus the mixed solvents composition at 25 deg. C. Then, we show that the polymer conformation adopts the Coil-Globule-Coil structure when the methanol molar fraction X{sub A} is varied. This transition is attributed to solvent quality change which result from water and methanol complex formation. The polymer contraction rate calculated for each composition takes its maximum value at X{sub A} = 0.17. Hildebrand theory assuming the solvents mixture as an equivalent solvent was used to analyze the change in mixed solvents quality. These changes can be attributed to dispersive forces in solvents mixture.

  19. Diversity, Prevalence, and Longitudinal Occurrence of Type II Toxin-Antitoxin Systems of Pseudomonas aeruginosa Infecting Cystic Fibrosis Lungs

    DEFF Research Database (Denmark)

    Breum Andersen, Sandra; Ghoul, Melanie; Griffin, Ashleigh S.

    2017-01-01

    Type II toxin-antitoxin (TA) systems are most commonly composed of two genes encoding a stable toxin, which harms the cell, and an unstable antitoxin that can inactivate it. TA systems were initially characterized as selfish elements, but have recently gained attention for regulating general stress...... responses responsible for pathogen virulence, formation of drug-tolerant persister cells and biofilms—all implicated in causing recalcitrant chronic infections. We use a bioinformatics approach to explore the distribution and evolution of type II TA loci of the opportunistic pathogen, Pseudomonas aeruginosa...... in their core genome and a variable number of the remaining 22 on genomic islands; (2) limited mutations in core genome TA loci, suggesting they are not under negative selection; (3) no evidence for horizontal transmission of elements with TA systems between clone types within patients, despite their ability...

  20. Production and characterization of biosurfactant from Pseudomonas ...

    African Journals Online (AJOL)

    Further characterization of biosurfactant using Fourier transform infrared spectroscopy (FTIR) revealed it as a rhamnolipid. Keywords: Mangrove ecosystems, Pseudomonas aeruginosa, biosurfactant, critical micelle concentration (CMC), FT-IR fourier transform infrared spectroscopy (FTIR). African Journal of Biotechnology, ...

  1. Quantitation of buried contamination by use of solvents. [degradation of silicone polymers by amine solvents

    Science.gov (United States)

    Pappas, S. P.; Hsiao, Y. C.; Hill, L. W.

    1973-01-01

    Spore recovery form cured silicone potting compounds using amine solvents to degrade the cured polymers was investigated. A complete list of solvents and a description of the effect of each on two different silicone polymers is provided.

  2. Pseudomonas putida and Pseudomonas fluorescens Species Group Recovery from Human Homes Varies Seasonally and by Environment.

    Directory of Open Access Journals (Sweden)

    Susanna K Remold

    Full Text Available By shedding light on variation in time as well as in space, long-term biogeographic studies can help us define organisms' distribution patterns and understand their underlying drivers. Here we examine distributions of Pseudomonas in and around 15 human homes, focusing on the P. putida and P. fluorescens species groups. We describe recovery from 10,941 samples collected during up to 8 visits per home, occurring on average 2.6 times per year. We collected a mean of 141 samples per visit, from sites in most rooms of the house, from the surrounding yards, and from human and pet occupants. We recovered Pseudomonas in 9.7% of samples, with the majority of isolates being from the P. putida and P. fluorescens species groups (approximately 62% and 23% of Pseudomonas samples recovered respectively. Although representatives of both groups were recovered from every season, every house, and every type of environment sampled, recovery was highly variable across houses and samplings. Whereas recovery of P. putida group was higher in summer and fall than in winter and spring, P. fluorescens group isolates were most often recovered in spring. P. putida group recovery from soils was substantially higher than its recovery from all other environment types, while higher P. fluorescens group recovery from soils than from other sites was much less pronounced. Both species groups were recovered from skin and upper respiratory tract samples from healthy humans and pets, although this occurred infrequently. This study indicates that even species that are able to survive under a broad range of conditions can be rare and variable in their distributions in space and in time. For such groups, determining patterns and causes of stochastic and seasonal variability may be more important for understanding the processes driving their biogeography than the identity of the types of environments in which they can be found.

  3. Solvent-vapor-assisted imprint lithography

    NARCIS (Netherlands)

    Voicu, Nicoleta E.; Ludwigs, Sabine; Crossland, Edward J. W.; Andrew, Piers; Steiner, Ullrich

    2007-01-01

    Sub-micrometer features are replicated into high-molecular-weight polymer resists by using solvent-assisted nanoimprint lithography (see figure). By swelling the polymer in a controlled solvent-vapor atmosphere, millibar pressures and ambient temperatures are sufficient to achieve high-fidelity

  4. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Directory of Open Access Journals (Sweden)

    Dnyanada S. Khanolkar

    2014-12-01

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

  5. Biotransformation of Tributyltin chloride by Pseudomonas stutzeri strain DN2

    Science.gov (United States)

    Khanolkar, Dnyanada S.; Naik, Milind Mohan; Dubey, Santosh Kumar

    2014-01-01

    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. PMID:25763027

  6. Decreased outer membrane permeability in imipenem-resistant mutants of Pseudomonas aeruginosa.

    OpenAIRE

    Trias, J; Dufresne, J; Levesque, R C; Nikaido, H

    1989-01-01

    The outer membrane of imipenem-resistant mutants of Pseudomonas aeruginosa was shown to have decreased permeability to imipenem but not to cephaloridine. These experiments were performed with intact cells and liposomes containing imipenem-hydrolyzing beta-lactamase derived from Pseudomonas maltophilia, in both cases utilizing an imipenem concentration of 50 microM. In contrast, liposome swelling assays using imipenem at 8 mM detected no significant difference between the imipenem-resistant mu...

  7. Diluent effects in solvent extraction. The Effects of Diluents in Solvent Extraction - a literature study

    International Nuclear Information System (INIS)

    Loefstroem-Engdahl, Elin; Aneheim, Emma; Ekberg, Christian; Foreman, Mark; Skarnemark, Gunnar

    2010-01-01

    The fact that the choice of organic diluent is important for a solvent extraction process goes without saying. Several factors, such as e.g. price, flash point, viscosity, polarity etc. each have their place in the planning of a solvent extraction system. This high number of variables makes the lack of compilations concerning diluent effects to an interesting topic. Often the interest for the research concerning a specific extraction system focuses on the extractant used and the complexes built up during an extraction. The diluents used are often classical ones, even if it has been shown that choice of diluent can affect extraction as well as separation in an extraction system. An attempt to point out important steps in the understanding of diluent effects in solvent extraction is here presented. This large field is, of course, not summarized in this article, but an attempt is made to present important steps in the understanding of diluents effects in solvent extraction. Trying to make the information concerning diluent effects and applications more easily accessible this review offers a selected summarizing of literature concerning diluents effects in solvent extraction. (authors)

  8. Pseudomonas cepacia adherence to respiratory epithelial cells is enhanced by Pseudomonas aeruginosa

    International Nuclear Information System (INIS)

    Saiman, L.; Cacalano, G.; Prince, A.

    1990-01-01

    Pseudomonas aeruginosa and Pseudomonas cepacia are both opportunistic pathogens of patients with cystic fibrosis. The binding characteristics of these two species were compared to determine if they use similar mechanisms to adhere to respiratory epithelial cells. P. cepacia 249 was shown to be piliated, but there was no detectable homology between P. aeruginosa pilin gene probes and P. cepacia genomic DNA. P. cepacia and P. aeruginosa did not appear to compete for epithelial receptors. In the presence of purified P. aeruginosa pili, the adherence of 35S-labeled strain 249 to respiratory epithelial monolayers was unaffected, while that of P. aeruginosa PAO1 was decreased by 55%. The binding of P. cepacia 249 and 715j was increased by 2.4-fold and 1.5-fold, respectively, in the presence of an equal inoculum of PAO1. Interbacterial agglutination contributed to the increased adherence of P. cepacia, as the binding of 249 was increased twofold in the presence of irradiated PAO1. PAO1 exoproducts had a marked effect in enhancing the ability of the P. cepacia strains to adhere to the epithelial monolayers. A PAO1 supernatant increased the binding of 249 by eightfold and that of 715j by fourfold. Thus, there appears to be a synergistic relationship between P. aeruginosa and P. cepacia in which PAO1 exoproducts modify the epithelial cell surface, exposing receptors and facilitating increased P. cepacia attachment

  9. Effect of solvent polarity and temperature on the spectral and thermodynamic properties of exciplexes of 1-cyanonaphthalene with hexamethylbenzene in organic solvents

    Energy Technology Data Exchange (ETDEWEB)

    Asim, Sadia [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Mansha, Asim [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry, Government College University, Faisalabad (Pakistan); Grampp, Günter, E-mail: grampp@tugraz.at [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Landgraf, Stephan [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Zahid, Muhammad [Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremaryrgasse 9, A-8010 Graz (Austria); Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad (Pakistan)

    2014-09-15

    Study of the effect of solvent polarity and temperature is done on the exciplex emission spectra of 1-cyanonaphthalene with hexamethylbenzene. Exciplex system is studied in the range of partially polar solvents and in solvent mixture of propyl acetate and butyronitrile. The unique feature of this solvent mixture is that only the solvent polarity changes (6.0≤ε{sub s}≤24.7) with the change in the mole fraction of solvents whereas the solvent viscosity and refractive index remains unaffected. Thermodynamic properties are calculated according to the models developed by Weller and Kuzmin. Fluorescence lifetimes for both the fluorophore as well as the exciplex are evaluated in all used solvents. Exciplex energetics as a function of solvent polarity and temperature are also discussed. Kuzmin model of self-consistent polarization is used for the explanation of the exciplex emission spectra. The effects of solvent polarity and temperature on energy of zero–zero transitions (hv{sub 0}{sup /}), Huang–Rhys factor (S), Gauss broadening of vibronic level (σ) and the dominant high-frequency vibration (hν{sub ν}) are investigated. The strong dependence of exciplex stability and energetics upon the solvent polarity and temperature are observed. Full charge transfer exciplexes were observed in solvents of all polarities and stronger exciplex with large emission intensities were found in solvents of low polarities but with the increase in solvent polarity the exciplex becomes weak and they dissociate fastly into radical ion pairs. The kinetic model of Kuzmin was observed to reduce into the Weller kinetic model for this exciplex system with ∆G{sub ET} = −0.22 eV and the spectral shift, h∆ν>0.2 eV. - Highlights: • Exciplex formed as a result of mixing of charge transfer and locally excited states. • Effect of solvents polarity and temperature on the exciplex stability and thermodynamics. • Solvent polarity will decide the formation of contact radical ion pair

  10. Aspergillus triggers phenazine production in Pseudomonas aeruginosa

    DEFF Research Database (Denmark)

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

    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......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...

  11. Solvent extraction studies of RERTR silicide fuels

    International Nuclear Information System (INIS)

    Gouge, Anthony P.

    1983-01-01

    Uranium silicide fuels, which are candidate RERTR fuel compositions, may require special considerations in solvent extraction reprocessing. Since Savannah River Plant may be reprocessing RERTR fuels as early as 1985, studies have been conducted at Savannah River Laboratory to demonstrate the solvent extraction behavior of this fuel. Results of solvent extraction studies with both unirradiated and irradiated fuel are presented along with the preliminary RERTR solvent extraction reprocessing flow sheet for Savannah River Plant. (author)

  12. Canyon solvent cleaning with activated alumina

    International Nuclear Information System (INIS)

    Reif, D.J.

    1987-01-01

    This paper presents recent work at SRL concerning the cleaning of solvent extraction solvent used at SRP. The paper explains why we undertook the work, and some laboratory studies on two approaches to solvent cleaning, namely extended carbonate washing and use of solid adsorbents. The paper then discusses scale-up of the preferred method and the results of the full-scale cleaning. 19 figs

  13. Extraction, scrub, and strip test results for the salt waste processing facility caustic side solvent extraction solvent example

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-08-01

    An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.9, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges.

  14. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Directory of Open Access Journals (Sweden)

    YOUNGJUNE ePARK

    2015-10-01

    Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

  15. Cyanide Degradation by Pseudomonas pseudoalcaligenes Strain W_2 Isolated from Mining Effluent

    International Nuclear Information System (INIS)

    Belinda Tiong; Zaratulnur Mohd Bahari; Nor Sahslin Irwan Shah Lee; Jafariah Jaafar; Zaharah Ibrahim; Shafinaz Shahir

    2015-01-01

    Cyanide is highly toxic to the living organisms as it inhibits respiration system in the cell mitochondria. Cyanide is commonly used in gold extraction process and its discharge into the environment not only causes pollution but it also brings harm to the surrounding population. Chemical treatment is expensive and the use of hazardous compound can exacerbate the problem. Biodegradation offers cheap and safe alternative as it overcomes the problems faced by chemical treatment. In this study, indigenous bacteria from mining wastewater were isolated. Cyanide degradation was done via shake flask method. A bacterium, designated W2 was found able to grow in the mining wastewater. 16S rRNA analysis identified the strain as Pseudomonas pseudoalcaligenes which could tolerate up to 39 mg/L cyanide concentration and growth was depleted at 52 mg/L. 60 % cyanide degradation was achieved in wastewater containing medium. End-product analysis from high performance liquid chromatography (HPLC) detected formamide implicating the role of cyanide hydratase in cyanide degradation. It can be concluded that P. pseudoalcaligenes is capable of biodegrading cyanide and its potential in wastewater treatment containing cyanide is feasible. (author)

  16. Hazardous solvent substitution

    International Nuclear Information System (INIS)

    Twitchell, K.E.

    1995-01-01

    Eliminating hazardous solvents is good for the environment, worker safety, and the bottom line. However, even though we are motivated to find replacements, the big question is 'What can we use as replacements for hazardous solvents?'You, too, can find replacements for your hazardous solvents. All you have to do is search for them. Search through the vendor literature of hundreds of companies with thousands of products. Ponder the associated material safety data sheets, assuming of course that you can obtain them and, having obtained them, that you can read them. You will want to search the trade magazines and other sources for product reviews. You will want to talk to users about how well the product actually works. You may also want to check US Environmental Protection Agency (EPA) and other government reports for toxicity and other safety information. And, of course, you will want to compare the product's constituent chemicals with the many hazardous constituency lists to ensure the safe and legal use of the product in your workplace

  17. Role of solvent-mediated carbodiimide cross-linking in fabrication of electrospun gelatin nanofibrous membranes as ophthalmic biomaterials

    International Nuclear Information System (INIS)

    Chou, Shih-Feng; Luo, Li-Jyuan; Lai, Jui-Yang; Ma, David Hui-Kang

    2017-01-01

    Due to their ability to mimic the structure of extracellular matrix, electrospun gelatin nanofibers are promising cell scaffolding materials for tissue engineering applications. However, the hydrophilic gelatin molecules usually need stabilization before use in aqueous physiological environment. Considering that biomaterials cross-linked via film immersion technique may have a more homogeneous cross-linked structure than vapor phase cross-linking, this work aims to investigate the chemical modification of electrospun gelatin nanofibrous membranes by liquid phase carbodiimide in the presence of ethanol/water co-solvents with varying ethanol concentrations ranging from 80 to 99.5 vol%. The results of characterization showed that increasing water content in the binary reaction solvent system increases the extent of cross-linking of gelatin nanofibers, but simultaneously promotes the effect of biopolymer swelling and distortion in fiber mat structure. As compared to non-cross-linked counterparts, carbodiimide treated gelatin nanofibrous mats exhibited better thermal and biological stability where the shrinkage temperature and resistance to enzymatic degradation varied in response to ethanol/water solvent composition-mediated generation of cross-links. Irrespective of their cross-linking density, all studied membrane samples did not induce any responses in ocular epithelial cell cultures derived from cornea, lens, and retina. Unlike many other cross-linking agents and/or methods (e.g., excessive vapor phase cross-linking) that may pose a risk of toxicity, our study demonstrated that these nanofibrous materials are well tolerated by anterior segment tissues. These findings also indicate the safety of using ethanol/water co-solvents for chemical cross-linking of gelatin to engineer nanofibrous materials with negligible biological effects. In summary, the present results suggest the importance of solvent-mediated carbodiimide cross-linking in modulating structure

  18. Role of solvent-mediated carbodiimide cross-linking in fabrication of electrospun gelatin nanofibrous membranes as ophthalmic biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Shih-Feng [Department of Mechanical Engineering, University of Texas at Tyler, Tyler, TX 75799 (United States); Luo, Li-Jyuan [Department of Chemical and Materials Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Lai, Jui-Yang, E-mail: jylai@mail.cgu.edu.tw [Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China); Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Materials Engineering, Ming Chi University of Technology, New Taipei City 24301, Taiwan, ROC (China); Ma, David Hui-Kang [Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan, ROC (China); Department of Chinese Medicine, Chang Gung University, Taoyuan 33302, Taiwan, ROC (China)

    2017-02-01

    Due to their ability to mimic the structure of extracellular matrix, electrospun gelatin nanofibers are promising cell scaffolding materials for tissue engineering applications. However, the hydrophilic gelatin molecules usually need stabilization before use in aqueous physiological environment. Considering that biomaterials cross-linked via film immersion technique may have a more homogeneous cross-linked structure than vapor phase cross-linking, this work aims to investigate the chemical modification of electrospun gelatin nanofibrous membranes by liquid phase carbodiimide in the presence of ethanol/water co-solvents with varying ethanol concentrations ranging from 80 to 99.5 vol%. The results of characterization showed that increasing water content in the binary reaction solvent system increases the extent of cross-linking of gelatin nanofibers, but simultaneously promotes the effect of biopolymer swelling and distortion in fiber mat structure. As compared to non-cross-linked counterparts, carbodiimide treated gelatin nanofibrous mats exhibited better thermal and biological stability where the shrinkage temperature and resistance to enzymatic degradation varied in response to ethanol/water solvent composition-mediated generation of cross-links. Irrespective of their cross-linking density, all studied membrane samples did not induce any responses in ocular epithelial cell cultures derived from cornea, lens, and retina. Unlike many other cross-linking agents and/or methods (e.g., excessive vapor phase cross-linking) that may pose a risk of toxicity, our study demonstrated that these nanofibrous materials are well tolerated by anterior segment tissues. These findings also indicate the safety of using ethanol/water co-solvents for chemical cross-linking of gelatin to engineer nanofibrous materials with negligible biological effects. In summary, the present results suggest the importance of solvent-mediated carbodiimide cross-linking in modulating structure

  19. Predictors of Pseudomonas and methicillin-resistant Staphylococcus aureus in hospitalized patients with healthcare-associated pneumonia.

    Science.gov (United States)

    Metersky, Mark L; Frei, Christopher R; Mortensen, Eric M

    2016-01-01

    Patients with healthcare-associated pneumonia (HCAP) are at high risk of infection with multidrug-resistant (MDR) pathogens. Factors discriminating infection with MDR Gram-negative (MDR-GN) organism from infection with methicillin-resistant Staphylococcus aureus (MRSA) are not well understood and patients are often treated for both organisms. This study was performed to determine risk factors predicting pneumonia due to Pseudomonas versus MRSA. Veterans age ≥65 hospitalized with HCAP between 2002 and 2012 were identified from the Veterans Affairs administrative databases. Patients were identified with Pseudomonas pneumonia, MRSA pneumonia or neither according to the International Classification of Diseases, 9th Revision, Clinical Modification codes. We assessed unadjusted and adjusted associations of patient characteristics and HCAP due to Pseudomonas or MRSA. Of the 61,651 patients with HCAP, 1156 (1.9%) were diagnosed with Pseudomonas pneumonia, 641 (1.0%) with MRSA pneumonia and 59,854 (97.1%) with neither. MRSA pneumonia was positively associated with male gender, age >74, diabetes, chronic obstructive pulmonary disease (COPD), recent nursing home or hospital stay, recent exposure to fluoroquinolone or antibiotics treating Gram-positive organisms, and severe pneumonia. MRSA pneumonia was negatively associated with complicated diabetes. Pseudomonas pneumonia was positively associated with recent hospital stay, immunocompromise, COPD, hemiplegia, recent exposure to inhaled corticosteroids, β-lactam/cephalosporin/carbapenem antibiotics, antibiotics against Gram-positive organisms, 'other antibiotics' and severe pneumonia. Pseudomonas pneumonia was negatively associated with age >84, higher socioeconomic status, drug abuse and diabetes. Patient characteristics may assist in identifying patients at risk for HCAP due to Pseudomonas or MRSA. © 2015 Asian Pacific Society of Respirology.

  20. Pseudomonas endophytica sp. nov., isolated from stem tissue of Solanum tuberosum L. in Spain.

    Science.gov (United States)

    Ramírez-Bahena, Martha-Helena; Cuesta, Maria José; Tejedor, Carmen; Igual, José Mariano; Fernández-Pascual, Mercedes; Peix, Álvaro

    2015-07-01

    A bacterial strain named BSTT44(T) was isolated in the course of a study of endophytic bacteria occurring in stems and roots of potato growing in a soil from Salamanca, Spain. The 16S rRNA gene sequence had 99.7% identity with respect to that of its closest relative, Pseudomonas psychrophila E-3T, and the next most closely related type strains were those of Pseudomonas fragi, with 99.6% similarity, Pseudomonas deceptionensis, with 99.2% similarity, and Pseudomonas lundensis, with 99.0% similarity; these results indicate that BSTT44(T) should be classified within the genus Pseudomonas. Analysis of the housekeeping genes rpoB, rpoD and gyrB confirmed its phylogenetic affiliation and showed identities lower than 92% in all cases with respect to the above-mentioned closest relatives. Cells of the strain bore one polar-subpolar flagellum. The respiratory quinone was Q-9.The major fatty acids were C16:0, C18:1ω7c and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The strain was oxidase-, catalase- and urease-positive and the arginine dihydrolase system was present, but tests for nitrate reduction, β-galactosidase production and aesculin hydrolysis were negative. It could grow at 35 °C and at pH 5-9.The DNA G+C content was 60.2 mol%. DNA-DNA hybridization results showed less than 48% relatedness with respect to the type strains of the four most closely related species. Therefore, the combined results of genotypic, phenotypic and chemotaxonomic analyses support the classification of strain BSTT44 into a novel species of the genus Pseudomonas, for which the name Pseudomonas endophytica sp. nov. is proposed. The type strain is BSTT44(T) ( = LMG 28456(T) = CECT 8691(T)).

  1. Recent solvent extraction experience at Savannah River

    International Nuclear Information System (INIS)

    Gray, L.W.; Burney, G.A.; Gray, J.H.; Hodges, M.E.; Holt, D.L.; Macafee, I.M.; Reif, D.J.; Shook, H.E.

    1986-01-01

    Tributyl phosphate-based solvent extraction processes have been used at Savannah River for more than 30 years to separate and purify thorium, uranium, neptunium, plutonium, americium, and curium isotopes. This report summarizes the advancement of solvent extraction technology at Savannah River during the 1980's. Topics that are discussed include equipment improvements, solvent treatment, waste reduction, and an improved understanding of the various chemistries in the process streams entering, within, and leaving the solvent extraction processes

  2. Effects of temperature and solvent concentration on the solvent crystallization of palm-based dihydroxystearic acid with isopropyl alcohol

    Institute of Scientific and Technical Information of China (English)

    Gregory F.L.Koay; Teong-Guan Chuah; Sumaiya Zainal-Abidin; Salmiah Ahmad; Thomas S.Y.Choong

    2012-01-01

    Palm-based dihydroxystearic acid of 69.55% purity was produced in a 500-kg-per-batch operation pilot plant and purified through solvent crystallization in a custom fabricated simultaneous batch crystallizer unit.The effects of temperature and solvent concentration on yield,particle size distribution and purity were studied.The purity was higher,while the yield and particle size were lower and smaller,respectively,at higher temperature and solvent concentration.The solvent crystallization process efficiency was rated at 66-69% when carried out with 70-80% isopropyl alcohol at 20 ℃.

  3. Solvents interactions with thermochromic print

    Directory of Open Access Journals (Sweden)

    Mirela Rožić

    2017-12-01

    Full Text Available In this study, the interactions between different solvents (benzene, acetone, cyclohexanone, various alcohols and water and thermochromic printing ink were investigated. Thermochromic printing ink was printed on metal surface. Components of thermochromic printing inks are polymeric microcapsules and classic yellow offset printing ink. Below its activation temperature, dye and developer within the microcapsules form a blue coloured complex. Therefore, thermochromic print is green. By heating above the activation temperature, blue colour of the complex turns into the leuco dye colourless state and the green colour of the prints turns into the yellow colour of the classic offset pigment. The results of the interaction with various solvents show that the thermochromic print is stable in all tested solvents except in ethanol, acetone and cyclohexanone. In ethanol, the green colour of the print becomes yellow. SEM analysis shows that microcapsules are dissolved. In acetone and cyclohexanone, the green colour of the print turns into blue, and the microcapsules become significantly more visible. Thus, the yellow pigment interacts with examined ketones. Based on the obtained interactions it can be concluded that the microcapsules have more polar nature than the classical pigment particles. Solvent-thermocromic print interactions were analysed using Hansen solubility parameters that rank the solvents based on their estimated interaction capabilities.

  4. Thermochemical Wastewater Valorization via Enhanced Microbial Toxicity Tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Thelhawadigedara, Lahiru Niroshan Jayakody [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnson, Christopher W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Pleitner, Brenna P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cleveland, Nicholas S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitham, Jason M. [Oak Ridge National Laboratory; Giannone, Richard J. [Oak Ridge National Laboratory; Klingeman, Dawn M. [Oak Ridge National Laboratory; Brown, Robert C. [Iowa State University; Brown, Steven D. [Oak Ridge National Laboratory; LanzaTech, Inc.; Hettich, Robert L. [Oak Ridge National Laboratory; Guss, Adam M. [Oak Ridge National Laboratory

    2018-04-17

    Thermochemical (TC) biomass conversion processes such as pyrolysis and liquefaction generate considerable amounts of wastewater, which often contains highly toxic compounds that are incredibly challenging to convert via standard wastewater treatment approaches such as anaerobic digestion. These streams represent a cost for TC biorefineries, and a potential valorization opportunity, if effective conversion methods are developed. The primary challenge hindering microbial conversion of TC wastewater is toxicity. In this study, we employ a robust bacterium, Pseudomonas putida, with TC wastewater streams to demonstrate that aldehydes are the most inhibitory compounds in these streams. Proteomics, transcriptomics, and fluorescence-based immunoassays of P. putida grown in a representative wastewater stream indicate that stress results from protein damage, which we hypothesize is a primary toxicity mechanism. Constitutive overexpression of the chaperone genes, groEL, groES, and clpB, in a genome-reduced P. putida strain improves the tolerance towards multiple TC wastewater samples up to 200-fold. Moreover, the concentration ranges of TC wastewater are industrially relevant for further bioprocess development for all wastewater streams examined here, representing different TC process configurations. Furthermore, we demonstrate proof-of-concept polyhydroxyalkanoate production from the usable carbon in an exemplary TC wastewater stream. Overall, this study demonstrates that protein quality control machinery and repair mechanisms can enable substantial gains in microbial tolerance to highly toxic substrates, including heterogeneous waste streams. When coupled to other metabolic engineering advances such as expanded substrate utilization and enhanced product accumulation, this study generally enables new strategies for biological conversion of highly-toxic, organic-rich wastewater via engineered aerobic monocultures or designer consortia.

  5. Density Changes in the Optimized CSSX Solvent System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.D.

    2002-11-25

    Density increases in caustic-side solvent extraction (CSSX) solvent have been observed in separate experimental programs performed by different groups of researchers. Such changes indicate a change in chemical composition. Increased density adversely affects separation of solvent from denser aqueous solutions present in the CSSX process. Identification and control of factors affecting solvent density are essential for design and operation of the centrifugal contactors. The goals of this research were to identify the factors affecting solvent density (composition) and to develop correlations between easily measured solvent properties (density and viscosity) and the chemical composition of the solvent, which will permit real-time determination and adjustment of the solvent composition. In evaporation experiments, virgin solvent was subjected to evaporation under quiescent conditions at 25, 35, and 45 C with continuously flowing dry air passing over the surface of the solvent. Density and viscosity were measured periodically, and chemical analysis was performed on the solvent samples. Chemical interaction tests were completed to determine if any chemical reaction takes place over extended contact time that changes the composition and/or physical properties. Solvent and simulant, solvent and strip solution, and solvent and wash solution were contacted continuously in agitated flasks. They were periodically sampled and the density measured (viscosity was also measured on some samples) and then submitted to the Chemical Sciences Division of Oak Ridge National Laboratory for analysis by nuclear magnetic resonance (NMR) spectrometry and high-performance liquid chromatography (HPLC) using the virgin solvent as the baseline. Chemical interaction tests showed that solvent densities and viscosities did not change appreciably during contact with simulant, strip, or wash solution. No effects on density and viscosity and no chemical changes in the solvent were noted within

  6. PARIS II: Computer Aided Solvent Design for Pollution Prevention

    Science.gov (United States)

    This product is a summary of U.S. EPA researchers' work developing the solvent substitution software tool PARIS II (Program for Assisting the Replacement of Industrial Solvents, version 2.0). PARIS II finds less toxic solvents or solvent mixtures to replace more toxic solvents co...

  7. Organic solvents in electromembrane extraction: recent insights

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-01-01

    the introduction. Under the influence of an electrical field, EME is based on electrokinetic migration of the analytes through a supported liquid membrane (SLM), which is an organic solvent immobilized in the pores of the polymeric membrane, and into the acceptor solution. Up to date, close to 150 research...... articles with focus on EME have been published. The current review summarizes the performance of EME with different organic solvents and discusses several criteria for efficient solvents in EME. In addition, the authors highlight their personal perspective about the most promising organic solvents for EME...... and have indicated that more fundamental work is required to investigate and discover new organic solvents for EME....

  8. Dendritic brushes under theta and poor solvent conditions

    Science.gov (United States)

    Gergidis, Leonidas N.; Kalogirou, Andreas; Charalambopoulos, Antonios; Vlahos, Costas

    2013-07-01

    The effects of solvent quality on the internal stratification of polymer brushes formed by dendron polymers up to third generation were studied by means of molecular dynamics simulations with Langevin thermostat. The distributions of polymer units, of the free ends, the radii of gyration, and the back folding probabilities of the dendritic spacers were studied at the macroscopic states of theta and poor solvent. For high grafting densities we observed a small decrease in the height of the brush as the solvent quality decreases. The internal stratification in theta solvent was similar to the one we found in good solvent, with two and in some cases three kinds of populations containing short dendrons with weakly extended spacers, intermediate-height dendrons, and tall dendrons with highly stretched spacers. The differences increase as the grafting density decreases and single dendron populations were evident in theta and poor solvent. In poor solvent at low grafting densities, solvent micelles, polymeric pinned lamellae, spherical and single chain collapsed micelles were observed. The scaling dependence of the height of the dendritic brush at high density brushes for both solvents was found to be in agreement with existing analytical results.

  9. 40 CFR Table 3 to Subpart Pppp of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction values in the... solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass fraction...

  10. 40 CFR 52.254 - Organic solvent usage.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Organic solvent usage. 52.254 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.254 Organic solvent usage. (a) This... (d) of this section and the architectural coatings and solvent disposal emission limitations...

  11. 27 CFR 21.125 - Rubber hydrocarbon solvent.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Rubber hydrocarbon solvent. 21.125 Section 21.125 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU....125 Rubber hydrocarbon solvent. (a) Rubber hydrocarbon solvent is a petroleum derivative. (b...

  12. The spectral properties of (--epigallocatechin 3-O-gallate (EGCG fluorescence in different solvents: dependence on solvent polarity.

    Directory of Open Access Journals (Sweden)

    Vladislav Snitsarev

    Full Text Available (--Epigallocatechin 3-O-gallate (EGCG a molecule found in green tea and known for a plethora of bioactive properties is an inhibitor of heat shock protein 90 (HSP90, a protein of interest as a target for cancer and neuroprotection. Determination of the spectral properties of EGCG fluorescence in environments similar to those of binding sites found in proteins provides an important tool to directly study protein-EGCG interactions. The goal of this study is to examine the spectral properties of EGCG fluorescence in an aqueous buffer (AB at pH=7.0, acetonitrile (AN (a polar aprotic solvent, dimethylsulfoxide (DMSO (a polar aprotic solvent, and ethanol (EtOH (a polar protic solvent. We demonstrate that EGCG is a highly fluorescent molecule when excited at approximately 275 nm with emission maxima between 350 and 400 nm depending on solvent. Another smaller excitation peak was found when EGCG is excited at approximately 235 nm with maximum emission between 340 and 400 nm. We found that the fluorescence intensity (FI of EGCG in AB at pH=7.0 is significantly quenched, and that it is about 85 times higher in an aprotic solvent DMSO. The Stokes shifts of EGCG fluorescence were determined by solvent polarity. In addition, while the emission maxima of EGCG fluorescence in AB, DMSO, and EtOH follow the Lippert-Mataga equation, its fluorescence in AN points to non-specific solvent effects on EGCG fluorescence. We conclude that significant solvent-dependent changes in both fluorescence intensity and fluorescence emission shifts can be effectively used to distinguish EGCG in aqueous solutions from EGCG in environments of different polarity, and, thus, can be used to study specific EGCG binding to protein binding sites where the environment is often different from aqueous in terms of polarity.

  13. Detection of metallo-beta-lactamase producing Pseudomonas ...

    African Journals Online (AJOL)

    sunny t

    2016-02-24

    Feb 24, 2016 ... Since the increasing prevalence of carbapenem-resistant Pseudomonas aeruginosa spp., accurate detection of metallo-β-lactamase (MBL) such as blaVIM type enzyme producing isolates became very important. However, phenotypic MBL detection methods previously reported are not highly sensitive or.

  14. The impact of nosocomially-acquired resistant Pseudomonas aeruginosa infection in a burn unit.

    Science.gov (United States)

    Armour, Alexis D; Shankowsky, Heather A; Swanson, Todd; Lee, Jonathan; Tredget, Edward E

    2007-07-01

    Nosocomially-acquired Pseudomonas aeruginosa remains a serious cause of infection and septic mortality in burn patients. This study was conducted to quantify the impact of nosocomially-transmitted resistant P. aeruginosa in a burn population. Using a TRACS burn database, 48 patients with P. aeruginosa resistant to gentamicin were identified (Pseudomonas group). Thirty-nine were case-matched to controls without resistant P. aeruginosa cultures (control group) for age, total body surface area, admission year, and presence of inhalation injury. Mortality and various morbidity endpoints were examined, as well as antibiotic costs. There was a significantly higher mortality rate in the Pseudomonas group (33% vs. 8%, p products used (packed cells 51.1 +/- 8.0 vs. 21.1 +/- 3.4, p < 0.01; platelets 11.9 +/- 3.0 vs. 1.4 +/- 0.7, p < 0.01) were all significantly higher in the Pseudomonas group. Cost of antibiotics was also significantly higher ($2,658.52 +/- $647.93 vs. $829.22 +/- $152.82, p < 0.01). Nosocomial colonization or infection, or both, of burn patients with aminoglycoside-resistant P. aeruginosa is associated with significantly higher morbidity, mortality, and cost of care. Increased resource consumption did not prevent significantly higher mortality rates when compared with that of control patients. Thus, prevention, identification, and eradication of nosocomial Pseudomonas contamination are critical for cost-effective, successful burn care.

  15. Identification of novel transaminases from a 12-aminododecanoic acid-metabolizing Pseudomonas strain.

    Science.gov (United States)

    Wilding, Matthew; Walsh, Ellen F A; Dorrian, Susan J; Scott, Colin

    2015-07-01

    A Pseudomonas species [Pseudomonas sp. strain amino alkanoate catabolism (AAC)] was identified that has the capacity to use 12-aminododecanoic acid, the constituent building block of homo-nylon-12, as a sole nitrogen source. Growth of Pseudomonas sp. strain AAC could also be supported using a range of additional ω-amino alkanoates. This metabolic function was shown to be most probably dependent upon one or more transaminases (TAs). Fourteen genes encoding putative TAs were identified from the genome of Pseudomonas sp. AAC. Each of the 14 genes was cloned, 11 of which were successfully expressed in Escherichia coli and tested for activity against 12-aminododecanoic acid. In addition, physiological functions were proposed for 9 of the 14 TAs. Of the 14 proteins, activity was demonstrated in 9, and of note, 3 TAs were shown to be able to catalyse the transfer of the ω-amine from 12-aminododecanoic acid to pyruvate. Based on this study, three enzymes have been identified that are promising biocatalysts for the production of nylon and related polymers. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  16. 40 CFR Table 3 to Subpart Mmmm of... - Default Organic HAP Mass Fraction for Solvents and Solvent Blends

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Default Organic HAP Mass Fraction for... Part 63—Default Organic HAP Mass Fraction for Solvents and Solvent Blends You may use the mass fraction.... If a solvent blend matches both the name and CAS number for an entry, that entry's organic HAP mass...

  17. Separation by solvent extraction

    International Nuclear Information System (INIS)

    Holt, C.H. Jr.

    1976-01-01

    In a process for separating fission product values from U and Pu values contained in an aqueous solution, an oxidizing agent is added to the solution to secure U and Pu in their hexavalent state. The aqueous solution is contacted with a substantially water-immiscible organic solvent with agitation while the temperature is maintained at from -1 to -2 0 C until the major part of the water present is frozen. The solid ice phase is continuously separated as it is formed and a remaining aqueous liquid phase containing fission product values and a solvent phase containing Pu and U values are separated from each other. The last obtained part of the ice phase is melted and added to the separated liquid phase. The resulting liquid is treated with a new supply of solvent whereby it is practically depleted of U and Pu

  18. Resistance patterns of Pseudomonas aeruginosa isolated from HIV ...

    African Journals Online (AJOL)

    negative bacilli in patients with impaired host defences emphasizes the need for information on the antibiotic susceptibility of the organisms that infects such patients. Pseudomonas aeruginosa are becoming increasingly resistant to ...

  19. Growth of Pseudomonas spp. in cottage cheese

    DEFF Research Database (Denmark)

    Østergaard, Nina Bjerre; Dalgaard, Paw

    Cottage cheese is a mixture of cheese curd with pH 4.5-4.8 and an uncultured or cultured cream dressing with a pH as high as 7.0. This results in a final product with microenvironments and a bulk pH of about 4.8 to 5.5. As for other lightly preserved foods microbial contamination and growth...... of spoilage microorganisms in cottage cheese can cause undesirable alterations in flavour, odour, appearance and texture. Contamination and growth of psychrotolerant pseudomonads including Pseudomonas fragi and Pseudomonas putida has been reported for cottage cheese but the influence of these bacteria...... on product spoilage and shelf-life remains poorly described. The present study used a quantitative microbial ecology approach to model and predict the effect of product characteristics and storage conditions on growth of psychrotolerant pseudomonads in cottage cheese. The effect of temperature (5-15˚C) and p...

  20. Molecular Thermodynamic Modeling of Mixed Solvent Solubility

    DEFF Research Database (Denmark)

    Ellegaard, Martin Dela; Abildskov, Jens; O’Connell, John P.

    2010-01-01

    A method based on statistical mechanical fluctuation solution theory for composition derivatives of activity coefficients is employed for estimating dilute solubilities of 11 solid pharmaceutical solutes in nearly 70 mixed aqueous and nonaqueous solvent systems. The solvent mixtures range from...... nearly ideal to strongly nonideal. The database covers a temperature range from 293 to 323 K. Comparisons with available data and other existing solubility methods show that the method successfully describes a variety of observed mixed solvent solubility behaviors using solute−solvent parameters from...

  1. Solvent distillations studies for a reprocessing plant

    International Nuclear Information System (INIS)

    Ginisty, C.; Guillaume, B.

    1989-01-01

    The substantial amounts of solvent used in large reprocessing plants are such that considerable care must be paid to solvent management to limit the production of organic wastes. The installation of intensive treatment by chemical regeneration serves to increase the service life of the solvent. General solvent management, combined with a distillation unit under reduced pressure also helps to recycle the two components of the solvent at a low activity level. Distillation also serves to remove the heavy degradation products that are generally responsible for poor hydraulic behavior and for the holdup of radioactive products such as plutonium, zirconium and ruthenium. From the safety standpoint, the flashpoint of the distilled diluent tends to rise. It can therefore be recycled without risk

  2. Mercury affects the distribution of culturable species of Pseudomonas in soil

    DEFF Research Database (Denmark)

    Holtze, Maria Sommer; Nielsen, Preben; Ekelund, Flemming

    2006-01-01

    Pseudomonas bacteria isolated during 52 days on Gould's S1 agar from soil spiked with 0, 3.5 and 15 mg Hg(II) kg soil(-1) were characterised to reveal whether mercury affected them differently. Isolates from the treatments with 0 and 15 mg Hg kg(-1) were characterised using FT-IR characterisation...... was almost exclusively restricted to P. frederiksbergensis and P. migulae groups. We conclude that Hg caused a shift in the dominating species of culturable Pseudomonas....

  3. Antibiotic Sensitivity in Pseudomonas aeruginosa of Diabetic Patient’s Foot Ulcer

    OpenAIRE

    Pratiwi Apridamayanti; Khairunnisa Azani Meilinasary; Rafika Sari

    2016-01-01

    Diabetes Mellitus (DM) patients are at risk to have the diabetic ulcer. The main reason for DM’s patient with ulcer complication to be treated and healed in hospital is bacterial infection. One of many bacteria that infects diabetic ulcer is Pseudomonas aeruginosa. This conditian can be treated by antibiotic. The using antibiotic is often inaccurate causing the microbe resistance. To choose the right antibiotic, it needs to test the antibiotic’s sensitivity towards Pseudomonas aeruginosa. The...

  4. Halotolerant rhizobacteria promote growth and enhance salinity tolerance in peanut

    Directory of Open Access Journals (Sweden)

    Sandeep Sharma

    2016-10-01

    Full Text Available Use of Plant growth promoting rhizobacteria (PGPR is a promising strategy to improve the crop production under optimal or sub-optimal conditions. In the present study, five diazotrophic salt tolerant bacteria were isolated from the roots of a halophyte, Arthrocnemum indicum. The isolates were partially characterized in vitro for plant growth promoting traits and evaluated for their potential to promote growth and enhanced salt tolerance in peanut. The 16S rRNA gene sequence homology indicated that these bacterial isolates belong to the genera, Klebisiella, Pseudomonas, Agrobacterium and Ochrobactrum. All isolates were nifH positive and able to produce indole -3-acetic acid (ranging from 11.5 to 19.1 µg ml-1. The isolates showed phosphate solubilisation activity (ranging from 1.4 to 55.6 µg phosphate /mg dry weight, 1-aminocyclopropane-1-carboxylate deaminase activity (0.1 to 0.31 µmol α-kB/µg protein/h and were capable of reducing acetylene in acetylene reduction assay (ranging from 0.95 to 1.8 µmol C2H4 mg protein/h. These isolates successfully colonized the peanut roots and were capable of promoting the growth under non-stress condition. A significant increase in total nitrogen (N content (up to 76% was observed over the non-inoculated control. All isolates showed tolerance to NaCl ranging from 4-8% in nutrient broth medium. Under salt stress, inoculated peanut seedlings maintained ion homeostasis, accumulated less reactive oxygen species (ROS and showed enhanced growth compared to non-inoculated seedlings. Overall, the present study has characterized several potential bacterial strains that showed an enhanced growth promotion effect on peanut under control as well as saline conditions. The results show the possibility to reduce chemical fertilizer inputs and may promote the use of bio-inoculants.

  5. Comparison of 432 Pseudomonas strains through integration of genomic, functional, metabolic and expression data

    NARCIS (Netherlands)

    Koehorst, Jasper J.; Dam, van Jesse C.J.; Heck, van Ruben G.A.; Saccenti, Edoardo; Martins dos Santos, Vitor; Suarez-Diez, Maria; Schaap, Peter J.

    2016-01-01

    Pseudomonas is a highly versatile genus containing species that can be harmful to humans and plants while others are widely used for bioengineering and bioremediation. We analysed 432 sequenced Pseudomonas strains by integrating results from a large scale functional comparison using protein

  6. Handbook of organic solvent properties

    CERN Document Server

    Smallwood, Ian

    2012-01-01

    The properties of 72 of the most commonly used solvents are given, tabulated in the most convenient way, making this book a joy for industrial chemists to use as a desk reference. The properties covered are those which answer the basic questions of: Will it do the job? Will it harm the user? Will it pollute the air? Is it easy to handle? Will it pollute the water? Can it be recovered or incinerated? These are all factors that need to be considered at the early stages of choosing a solvent for a new product or process.A collection of the physical properties of most commonly used solvents, their

  7. Multiple sclerosis and organic solvents

    DEFF Research Database (Denmark)

    Mortensen, J T; Brønnum-Hansen, Henrik; Rasmussen, K

    1998-01-01

    We investigated a possible causal relation between exposure to organic solvents in Danish workers (housepainters, typographers/printers, carpenters/cabinetmakers) and onset of multiple sclerosis. Data on men included in the Danish Multiple Sclerosis Register (3,241 men) were linked with data from......, and butchers. Over a follow-up period of 20 years, we observed no increase in the incidence of multiple sclerosis among men presumed to be exposed to organic solvents. It was not possible to obtain data on potential confounders, and the study design has some potential for selection bias. Nevertheless......, the study does not support existing hypotheses regarding an association between occupational exposure to organic solvents and multiple sclerosis....

  8. Large-scale production of poly(3-hydroxyoctanoic acid) by Pseudomonas putida GPo1 and a simplified downstream process.

    Science.gov (United States)

    Elbahloul, Yasser; Steinbüchel, Alexander

    2009-02-01

    The suitability of Pseudomonas putida GPo1 for large-scale cultivation and production of poly(3-hydroxyoctanoate) (PHO) was investigated in this study. Three fed-batch cultivations of P. putida GPo1 at the 350- or 400-liter scale in a bioreactor with a capacity of 650 liters were done in mineral salts medium containing initially 20 mM sodium octanoate as the carbon source. The feeding solution included ammonium octanoate, which was fed at a relatively low concentration to promote PHO accumulation under nitrogen-limited conditions. During cultivation, the pH was regulated by addition of NaOH, NH(4)OH, or octanoic acid, which was used as an additional carbon source. Partial O(2) pressure (pO(2)) was adjusted to 20 to 40% by controlling the airflow and stirrer speed. Under the optimized conditions, P. putida GPo1 was able to grow to cell densities as high as 18, 37, and 53 g cells (dry mass) (CDM) per liter containing 49, 55, and 60% (wt/wt) of PHO, respectively. The resulting 40 kg CDM from these three cultivations was used directly for extraction of PHO. Three different methods of extraction of PHO were applied. From these, only acetone extraction showed better performance and resulted in 94% recovery of the PHO contents of cells. A novel mixture of precipitation solvents composed of 70% (vol/vol) methanol and 70% (vol/vol) ethanol was identified in this study. The ratio of PHO concentrate to the mixture was 0.2:1 (vol/vol) and allowed complete precipitation of PHO as white flakes. However, at a ratio of 1:1 (vol/vol) of the solvent mixture to PHO concentrate, a highly purified PHO was obtained. Precipitation yielded a dough-like polymeric material which was cast into thin layers and then shredded into small strips to allow evaporation of the remaining solvents. Gas chromatographic analysis revealed a purity of about 99% +/- 0.2% (wt/wt) of the polymer, which consisted mainly of 3-hydroxyoctanoic acid (96 mol%).

  9. Performance of thermal solvent process in Athabasca reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Das, Swapan [Marathon Oil (Canada)

    2011-07-01

    In the petroleum industry, due to depletion of conventional resources and high demand operators are looking into heavy oil and bitumen production. Different recovery methods exist, some of them based on heating the reservoir and others on the use of solvent. Thermal solvent process is a combination of both: a small amount of heat is used to maintain a solvent vapor phase in the reservoir. This process has advantages, solvent is mostly recycled which increases bitumen recovery efficiency and reduces the need for fresh solvent, but it also poses challenges, such as maintaining a vapor chamber and the fact that solvent solubility might be affected by heating. The aim of this paper is to discuss these issues. Simulations and field tests were conducted on bitumen in the the Athabasca region. This paper presented a thermal solvent process and its application's results in Athabasca reservoir.

  10. ANOMALOUS BLUE COLOURING OF MOZZARELLA CHEESE INTENTIONALLY CONTAMINATED WITH PIGMENT PRODUCING STRAINS OF PSEUDOMONAS FLUORESCENS

    Directory of Open Access Journals (Sweden)

    P. Sechi

    2011-04-01

    Full Text Available In summer 2010 a large outbreak of anomalous blue coloration of mozzarella cheese was recorded in Italy and some northern European countries. Official laboratory analysis and health authorities linked the outbreak to the contamination of processing water with strains of Pseudomonas fluorescens, although several expert raised the question of how to unequivocally link the blue coloring to the presence of the micro-organism. In an attempt to set-up a method to determine whether a given Pseudomonas spp. strain is responsible of the defect, an in vitro system for the evaluation of blue colouring of mozzarella cheese intentionally contaminated with strains of Pseudomonas fluorescens. was developed The system is aimed to ascertain whether P. fluorescens strains, isolated from mozzarella cheese with anomalous blue coloration, are able to reproduce the blue coloration under controlled experimental condition. 96 trials of experimental inoculation of mozzarella cheese in different preservation liquids, were conducted using various suspension of Pseudomonas spp. (P. fluorescens ATCC 13525, P. fluorescens CFBP 3150, one P. fluorescens field strain isolated from blue-colored mozzarella cheese and P. aeruginosa ATCC 10145 as positive control at different concentrations and incubated at different temperatures. Growth curve of all Pseudomonas spp. strains tested demonstrated that after three days of incubation the concentration was generally higher than 106 CFU/g of mozzarella cheese incubated in Tryptic Soy Broth (TSB, and higher than 105 CFU/g of mozzarella cheese incubated in preservation liquid. All mozzarella cheeses inoculated with the field strain of Pseudomonas fluorescens showed the characteristic anomalous blue coloration, which is often associated with Pseudomonas fluorescens contamination of water used during mozzarella cheesemaking. With the proposed system, which enabled a considerable amount of samples to be analysed under controlled experimental

  11. Accumulation of solvent-soluble and solvent-insoluble antioxidant phenolics in edible bean sprouts: implication of germination

    Directory of Open Access Journals (Sweden)

    Ren-You Gan

    2016-08-01

    Full Text Available Background: Edible bean sprouts are popular fresh vegetables widely recognized for their nutritional quality. However, while their antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble extracts has not been systematically evaluated. Methods: The antioxidant capacity and phenolic composition in both solvent-soluble and solvent-insoluble fractions of 12 cultivars of edible bean sprouts were evaluated, and relationships of antioxidant capacity and total phenolic content were also analyzed. Results: Sprouts demonstrated a wide range of antioxidant capacity and total phenolic content, with lower but substantial antioxidant capacity and total phenolic content in the solvent-insoluble fractions. Highest levels were found in the green mung bean sprout. Phenolic compounds, such as catechin, ellagic acid, ferulic acid, gallic acid and p-coumaric acid were widely detected in these sprouts. Additionally, a positive correlation was discovered between antioxidant capacity and total phenolic content in these edible bean sprouts. Conclusions: Germination generally resulted in the accumulation of antioxidant phenolics in the most edible bean sprouts. Edible bean sprouts with high antioxidant phenolics can be valuable natural sources of dietary antioxidants for the prevention of oxidative stress-related chronic diseases.

  12. Comparative evaluation of organic formulations of Pseudomonas ...

    African Journals Online (AJOL)

    An experiment was conducted in the laboratory and farm of the Department of Biotechnology, Gauhati University, to explore the potentiality of various organic formulations of Pseudomonas fluorescens (Pf) and to manage bacterial wilt disease of brinjal (Solanum melongena L.) under local conditions. Different organic ...

  13. Enhanced alpha-galactosidase expression in pseudomonas chlororaphis

    Science.gov (United States)

    Pseudomonas chlororaphis is a non-pathogenic bacterium useful for fermentative production of biopolymer (i.e., poly(hydroxyalkanoates); PHA) and biosurfactant (i.e., rhamnolipid; RhL). In order to enable P. chlororaphis to better fermentatively utilize the residual soy sugars in soy molasses – a lo...

  14. Rhizosphere-associated Pseudomonas induce systemic resistance to herbivores at the cost of susceptibility to bacterial pathogens.

    Science.gov (United States)

    Haney, Cara H; Wiesmann, Christina L; Shapiro, Lori R; Melnyk, Ryan A; O'Sullivan, Lucy R; Khorasani, Sophie; Xiao, Li; Han, Jiatong; Bush, Jenifer; Carrillo, Juli; Pierce, Naomi E; Ausubel, Frederick M

    2017-10-31

    Plant-associated soil microbes are important mediators of plant defence responses to diverse above-ground pathogen and insect challengers. For example, closely related strains of beneficial rhizosphere Pseudomonas spp. can induce systemic resistance (ISR), systemic susceptibility (ISS) or neither against the bacterial foliar pathogen Pseudomonas syringae pv. tomato DC3000 (Pto DC3000). Using a model system composed of root-associated Pseudomonas spp. strains, the foliar pathogen Pto DC3000 and the herbivore Trichoplusia ni (cabbage looper), we found that rhizosphere-associated Pseudomonas spp. that induce either ISS and ISR against Pto DC3000 all increased resistance to herbivory by T. ni. We found that resistance to T. ni and resistance to Pto DC3000 are quantitative metrics of the jasmonic acid (JA)/salicylic acid (SA) trade-off and distinct strains of rhizosphere-associated Pseudomonas spp. have distinct effects on the JA/SA trade-off. Using genetic analysis and transcriptional profiling, we provide evidence that treatment of Arabidopsis with Pseudomonas sp. CH267, which induces ISS against bacterial pathogens, tips the JA/SA trade-off towards JA-dependent defences against herbivores at the cost of a subset of SA-mediated defences against bacterial pathogens. In contrast, treatment of Arabidopsis with the ISR strain Pseudomonas sp. WCS417 disrupts JA/SA antagonism and simultaneously primes plants for both JA- and SA-mediated defences. Our findings show that ISS against the bacterial foliar pathogens triggered by Pseudomonas sp. CH267, which is a seemingly deleterious phenotype, may in fact be an adaptive consequence of increased resistance to herbivory. Our work shows that pleiotropic effects of microbiome modulation of plant defences are important to consider when using microbes to modify plant traits in agriculture. © 2017 John Wiley & Sons Ltd.

  15. Evolutionary Plasticity of AmrZ Regulation in Pseudomonas

    Science.gov (United States)

    Dougherty, Kevin; Diaz, Beatriz; Murillo, Rachel

    2018-01-01

    ABSTRACT amrZ encodes a master regulator protein conserved across pseudomonads, which can be either a positive or negative regulator of swimming motility depending on the species examined. To better understand plasticity in the regulatory function of AmrZ, we characterized the mode of regulation for this protein for two different motility-related phenotypes in Pseudomonas stutzeri. As in Pseudomonas syringae, AmrZ functions as a positive regulator of swimming motility within P. stutzeri, which suggests that the functions of this protein with regard to swimming motility have switched at least twice across pseudomonads. Shifts in mode of regulation cannot be explained by changes in AmrZ sequence alone. We further show that AmrZ acts as a positive regulator of colony spreading within this strain and that this regulation is at least partially independent of swimming motility. Closer investigation of mechanistic shifts in dual-function regulators like AmrZ could provide unique insights into how transcriptional pathways are rewired between closely related species. IMPORTANCE Microbes often display finely tuned patterns of gene regulation across different environments, with major regulatory changes controlled by a small group of “master” regulators within each cell. AmrZ is a master regulator of gene expression across pseudomonads and can be either a positive or negative regulator for a variety of pathways depending on the strain and genomic context. Here, we demonstrate that the phenotypic outcomes of regulation of swimming motility by AmrZ have switched at least twice independently in pseudomonads, so that AmrZ promotes increased swimming motility in P. stutzeri and P. syringae but represses this phenotype in Pseudomonas fluorescens and Pseudomonas aeruginosa. Since examples of switches in regulatory mode are relatively rare, further investigation into the mechanisms underlying shifts in regulator function for AmrZ could provide unique insights into the

  16. Green solvents and technologies for oil extraction from oilseeds.

    Science.gov (United States)

    Kumar, S P Jeevan; Prasad, S Rajendra; Banerjee, Rintu; Agarwal, Dinesh K; Kulkarni, Kalyani S; Ramesh, K V

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n -hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330 kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to look for alternative options. To circumvent the problem, green solvents could be a promising approach to replace solvent extraction. In this review, green solvents and technology like aqueous assisted enzyme extraction are better solution for oil extraction from oilseeds. Enzyme mediated extraction is eco-friendly, can obtain higher yields, cost-effective and aids in obtaining co-products without any damage. Enzyme technology has great potential for oil extraction in oilseed industry. Similarly, green solvents such as terpenes and ionic liquids have tremendous solvent properties that enable to extract the oil in eco-friendly manner. These green solvents and technologies are considered green owing to the attributes of energy reduction, eco-friendliness, non-toxicity and non-harmfulness. Hence, the review is mainly focussed on the prospects and challenges of green solvents and technology as the best option to replace the conventional methods without compromising the quality of the extracted products.

  17. Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

    CERN Document Server

    Marcus, Y; Kertes, A S

    2013-01-01

    Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

  18. Batch extracting process using magnetic particle held solvents

    Science.gov (United States)

    Nunez, L.; Vandergrift, G.F.

    1995-11-21

    A process is described for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents. 5 figs.

  19. Biosorption of uranium by Pseudomonas aeruginosa strain CSU: Characterization and comparison studies

    International Nuclear Information System (INIS)

    Hu, M.Z.C.; Norman, J.M.; Faison, B.D.; Reeves, M.E.

    1996-01-01

    Pseudomonas aeruginosa strain CSU, a nongenetically engineered bacterial strain known to bind dissolved hexavalent uranium (as UO 2 2+ and/or its cationic hydroxo complexes) was characterized with respect to its sorptive activity. The uranium biosorption equilibrium could be described by the Langmuir isotherm. The rate of uranium adsorption increased following permeabilization of the outer and/or cytoplasmic membrane by organic solvents such as acetone. P. aeruginosa CSU biomass was significantly more sorptive toward uranium than certain novel, patented biosorbents derived from algal or fungal biomass sources. P. aeruginosa CSU biomass was also competitive with commercial cation-exchange resins, particularly in the presence of dissolved transition metals. Uranium binding by P. aeruginosa CSU was clearly pH dependent. Uranium loading capacity increased with increasing pH under acidic conditions, presumably as a function of uranium speciation and due to the H + competition at some binding sites. Nevertheless, preliminary evidence suggests that this microorganism is also capable of binding anionic hexavalent uranium complexes. Ferric iron was a strong inhibitor of uranium binding to P. aeruginosa CSU biomass, and the presence of uranium also decreased the Fe 3+ loading when the biomass was not saturated with Fe 3+ . Thus, a two-state process in which iron and uranium are removed in consecutive steps was proposed for efficient use of the biomass as a biosorbent in uranium removal from mine wastewater, especially acidic leachates

  20. Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

    2015-10-01

    CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

  1. Fluoro-Carbonate Solvents for Li-Ion Cells

    International Nuclear Information System (INIS)

    NAGASUBRAMANIAN, GANESAN

    1999-01-01

    A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF(sub 6) was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF(sub 6) electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to and lt;5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature

  2. Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

    International Nuclear Information System (INIS)

    Clark, Sue B.

    2016-01-01

    The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

  3. Controlling Actinide Hydration in Mixed Solvent Systems: Towards Tunable Solvent Systems to Close the Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Sue B. [Washington State Univ., Pullman, WA (United States). Dept. of Chemistry

    2016-10-31

    The goal of this project has been to define the extent of hydration the f-elements and other cations in mixed solvent electrolyte systems. Methanol-water and other mixed solvent systems have been studied, where the solvent dielectric constant was varied systematically. Thermodynamic and spectroscopic studies provide details concerning the energetics of complexation and other reactions of these cations. This information has also been used to advance new understanding of the behavior of these cations in a variety of systems, ranging from environmental studies, chromatographic approaches, and ionization processes for mass spectrometry.

  4. Lipase From Thermoalkalophilic Pseudomonas species as an Additive in Potential Laundry Detergent Formulations

    Directory of Open Access Journals (Sweden)

    Ibrahim, C. O.

    2009-01-01

    Full Text Available Lipase isolated from a thermoalkalophilic Pseudomonas species was used as additive to improve the degree of olive oil removal from cotton fabric in the presence of surfactants. The lipase used in this study was found to be more effective with non ionic surfactants as compared to ionic surfactants. In terms of stability, there was no decrease in activity found in the presence of Tween 85, Span 80 and Span 20. Lipase from Pseudomonas species was most active in the presence of Tween 85, Span 80 and Span 20. The application of lipase from Pseudomonas species as an additive in the formulation containing Span 80 has improved oil removal by 36% using the washing system consisting 5 U/mL lipase, at 70 °C for 20 min and 0.8% of Span 80 as surfactant. Considering that lipase from Pseudomonas species is stable in high pH and temperatures in the presence of various surfactants, therefore it is suitable to be incorporated as additives in potential detergent formulations.

  5. Multiple Pseudomonas species secrete exolysin-like toxins and provoke Caspase-1-dependent macrophage death.

    Science.gov (United States)

    Basso, Pauline; Wallet, Pierre; Elsen, Sylvie; Soleilhac, Emmanuelle; Henry, Thomas; Faudry, Eric; Attrée, Ina

    2017-10-01

    Pathogenic bacteria secrete protein toxins that provoke apoptosis or necrosis of eukaryotic cells. Here, we developed a live-imaging method, based on incorporation of a DNA-intercalating dye into membrane-damaged host cells, to study the kinetics of primary bone marrow-derived macrophages (BMDMs) mortality induced by opportunistic pathogen Pseudomonas aeruginosa expressing either Type III Secretion System (T3SS) toxins or the pore-forming toxin, Exolysin (ExlA). We found that ExlA promotes the activation of Caspase-1 and maturation of interleukin-1β. BMDMs deficient for Caspase-1 and Caspase-11 were resistant to ExlA-induced death. Furthermore, by using KO BMDMs, we determined that the upstream NLRP3/ASC complex leads to the Caspase-1 activation. We also demonstrated that Pseudomonas putida and Pseudomonas protegens and the Drosophila pathogen Pseudomonas entomophila, which naturally express ExlA-like toxins, are cytotoxic toward macrophages and provoke the same type of pro-inflammatory death as does ExlA + P. aeruginosa. These results demonstrate that ExlA-like toxins of two-partner secretion systems from diverse Pseudomonas species activate the NLRP3 inflammasome and provoke inflammatory pyroptotic death of macrophages. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. [Pseudomonas infection: biological risk by occupational exposure and results of an environmental monitoring].

    Science.gov (United States)

    Massoni, Francesco; Giorgi, Doriana Antonella; Palmieri, Sabina; Arcangeli, Luca; Ricci, Serafino

    2014-01-01

    The biological risk of Pseudomonas aeruginosa for activities involving exposure to contaminated water, such as, for example, routine maintenance of swimming pools, is related to the availability of effective prophylactic and therapeutic measures. The authors present the data of the microbiological analyzes made on 2349 samples taken from pools in Rome and province. The contamination by Pseudomonas was found in 191 samples with 13 samples that had a level > 100 cfu/100 ml and 5 samples with level > 200 cfu/100 ml. Useful considerations derived from the analysis of the literature about the profile and prophylactic treatment of infection by Pseudomonas, necessarily to be taken into consideration for an adequate risk assessment.

  7. Method of decomposing radioactive organic solvent wastes

    International Nuclear Information System (INIS)

    Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

    1986-01-01

    Purpose: To decompose radioactive organic solvent wastes or radioactive hydrocarbon solvents separated therefrom into organic materials under moderate conditions, as well as greatly decrease the amount of secondary wastes generated. Method: Radioactive organic solvent wastes comprising an organic phosphoric acid ester ingredient and a hydrocarbon ingredient as a diluent therefor, or radioactive hydrocarbon solvents separated therefrom are oxidatively decomposed by hydrogen peroxide in an aqueous phosphoric acid solution of phosphoric acid metal salts finally into organic materials to perform decomposing treatment for the radioactive organic solvent wastes. The decomposing reaction is carried out under relatively moderate conditions and cause less burden to facilities or the likes. Further, since the decomposed liquid after the treatment can be reused for the decomposing reaction as a catalyst solution secondary wastes can significantly be decreased. (Yoshihara, H.)

  8. Permeability of commercial solvents through living human skin

    DEFF Research Database (Denmark)

    Ursin, C; Hansen, C M; Van Dyk, J W

    1995-01-01

    A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... of DMSO and octyl acetate were measured. No octyl acetate was detected and the permeability of DMSO was proportional to its mole fraction in the mixture. The effect of two hours of solvent exposure on the viability of skin (based on DNA synthesis) was measured and found to be very dependent on the solvent....

  9. Engineering Pseudomonas protegens Pf-5 for Nitrogen Fixation and its Application to Improve Plant Growth under Nitrogen-Deficient Conditions

    Science.gov (United States)

    Setten, Lorena; Soto, Gabriela; Mozzicafreddo, Matteo; Fox, Ana Romina; Lisi, Christian; Cuccioloni, Massimiliano; Angeletti, Mauro; Pagano, Elba; Díaz-Paleo, Antonio; Ayub, Nicolás Daniel

    2013-01-01

    Nitrogen is the second most critical factor for crop production after water. In this study, the beneficial rhizobacterium Pseudomonas protegens Pf-5 was genetically modified to fix nitrogen using the genes encoding the nitrogenase of Pseudomonas stutzeri A1501 via the X940 cosmid. Pf-5 X940 was able to grow in L medium without nitrogen, displayed high nitrogenase activity and released significant quantities of ammonium to the medium. Pf-5 X940 also showed constitutive expression and enzymatic activity of nitrogenase in ammonium medium or in nitrogen-free medium, suggesting a constitutive nitrogen fixation. Similar to Pseudomonas protegens Pf-5, Pseudomonas putida, Pseudomonas veronii and Pseudomonas taetrolens but not Pseudomonas balearica and Pseudomonas stutzeri transformed with cosmid X940 showed constitutive nitrogenase activity and high ammonium production, suggesting that this phenotype depends on the genome context and that this technology to obtain nitrogen-fixing bacteria is not restricted to Pf-5. Interestingly, inoculation of Arabidopsis, alfalfa, tall fescue and maize with Pf-5 X940 increased the ammonium concentration in soil and plant productivity under nitrogen-deficient conditions. In conclusion, these results open the way to the production of effective recombinant inoculants for nitrogen fixation on a wide range of crops. PMID:23675499

  10. Chlorinated solvents in groundwater of the United States

    Science.gov (United States)

    Moran, M.J.; Zogorski, J.S.; Squillace, P.J.

    2007-01-01

    Four chlorinated solvents-methylene chloride, perchloroethene (PCE), 1,1,1-trichloroethane, and trichloroethene (TCE)-were analyzed in samples of groundwater taken throughout the conterminous United States by the U.S. Geological Survey. The samples were collected between 1985 and 2002 from more than 5,000 wells. Of 55 volatile organic compounds (VOCs) analyzed in groundwater samples, solvents were among the most frequently detected. Mixtures of solvents in groundwater were common and may be the result of common usage of solvents or degradation of one solvent to another. Relative to other VOCs with Maximum Contaminant Levels (MCLs), PCE and TCE ranked high in terms of the frequencies of concentrations greater than or near MCLs. The probability of occurrence of solvents in groundwater was associated with dissolved oxygen content of groundwater, sources such as urban land use and population density, and hydraulic properties of the aquifer. The results reinforce the importance of understanding the redox conditions of aquifers and the hydraulic properties of the saturated and vadose zones in determining the intrinsic susceptibility of groundwater to contamination by solvents. The results also reinforce the importance of controlling sources of solvents to groundwater. ?? 2007 American Chemical Society.

  11. Recent trends in ionic liquid (IL) tolerant enzymes and microorganisms for biomass conversion.

    Science.gov (United States)

    Portillo, Maria Del Carmen; Saadeddin, Anas

    2015-01-01

    Second generation biofuel production depends on lignocellulosic (LC) biomass transformation into simple sugars and their subsequent fermentation into alcohols. However, the main obstacle in this process is the efficient breakdown of the recalcitrant cellulose to sugar monomers. Hence, efficient feedstock pretreatment and hydrolysis are necessary to produce a cost effective biofuel. Recently, ionic liquids (ILs) have been recognized as a promising solvent able to dissolve different biomass feedstocks, providing higher sugar yields. However, most of the hydrolytic enzymes and microorganisms are inactivated, completely or partially, in the presence of even low concentrations of IL, making necessary the discovery of novel hydrolytic enzymes and fermentative microorganisms that are tolerant to ILs. In this review, the current state and the challenges of using ILs as a pretreatment of LC biomass was evaluated, underlining the advances in the discovery and identification of new IL-tolerant enzymes and microorganisms that could improve the bioprocessing of biomass to fuels and chemicals.

  12. Next Generation Solvent - Materials Compatibility With Polymer Components Within Modular Caustic-Side Solvent Extraction Unit (Final Report)

    International Nuclear Information System (INIS)

    Fondeur, F.; Peters, T.; Fink, S.

    2012-01-01

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX(reg s ign)79 and MaxCalix was varied systematically) showed that LIX(reg s ign)79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX(reg s ign)79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX(reg s ign)79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX(reg s ign)79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

  13. NEXT GENERATION SOLVENT-MATERIALS COMPATIBILITY WITH POLYMER COMPONENTS WITHIN MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT (FINAL REPORT)

    Energy Technology Data Exchange (ETDEWEB)

    Fondeur, F.; Peters, T.; Fink, S.

    2012-01-17

    The Office of Waste Processing, within the Office of Technology Innovation and Development, is funding the development of an enhanced solvent for deployment at the Savannah River Site for removal of cesium from High Level Waste. The technical effort is collaboration between Oak Ridge National Laboratory (ORNL), Savannah River National Laboratory (SRNL), and Argonne National Laboratory. The first deployment target for the technology is within the Modular Caustic-Side Solvent Extraction Unit (MCU). Deployment of a new chemical within an existing facility requires verification that the chemical components are compatible with the installed equipment. In the instance of a new organic solvent, the primary focus is on compatibility of the solvent with organic polymers used in the facility. This report provides the data from exposing these polymers to the Next Generation Solvent (NGS). The test was conducted over six months. An assessment of the dimensional stability of polymers present in MCU (i.e., PEEK, Grafoil, Tefzel and Isolast) in the modified NGS (where the concentration of LIX{reg_sign}79 and MaxCalix was varied systematically) showed that LIX{reg_sign}79 selectively affected Tefzel and its different grades (by an increase in size and lowering its density). The copolymer structure of Tefzel and possibly its porosity allows for the easier diffusion of LIX{reg_sign}79. Tefzel is used as the seat material in some of the valves at MCU. Long term exposure to LIX{reg_sign}79, may make the valves hard to operate over time due to the seat material (Tefzel) increasing in size. However, since the physical changes of Tefzel in the improved solvent are comparable to the changes in the CSSX baseline solvent, no design changes are needed with respect to the Tefzel seating material. PEEK, Grafoil and Isolast were not affected by LIX{reg_sign}79 and MaxCalix within six months of exposure. The initial rapid weight gain observed in every polymer is assigned to the finite and

  14. Screening of thermophilic neutral lipase-producing Pseudomonas ...

    African Journals Online (AJOL)

    From oil-contaminated soil, three lipase-producing microorganisms were selected as good lipase producers using rhodamine B-olive oil plate agar and they were identified as from Pseudomonas, Burkholderia and Klebsiella genera by morphology, biochemical characterization and 16S rRNA gene sequencing. Among the ...

  15. Evaluation of gamma irradiation effect and Pseudomonas ...

    African Journals Online (AJOL)

    Antagonistic effect of Pseudomonas fluorescens and influence of gamma irradiation on the development of Penicillium expansum, the causal agent of postharvest disease on apple fruit was studied. P. fluorescens was originally isolated from rhizosphere of the apple trees. Suspension of P. fluorescens and P. expansum ...

  16. 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...

  17. A Biofilm Matrix-Associated Protease Inhibitor Protects Pseudomonas aeruginosa from Proteolytic Attack.

    Science.gov (United States)

    Tseng, Boo Shan; Reichhardt, Courtney; Merrihew, Gennifer E; Araujo-Hernandez, Sophia A; Harrison, Joe J; MacCoss, Michael J; Parsek, Matthew R

    2018-04-10

    Pseudomonas aeruginosa produces an extracellular biofilm matrix that consists of nucleic acids, exopolysaccharides, lipid vesicles, and proteins. In general, the protein component of the biofilm matrix is poorly defined and understudied relative to the other major matrix constituents. While matrix proteins have been suggested to provide many functions to the biofilm, only proteins that play a structural role have been characterized thus far. Here we identify proteins enriched in the matrix of P. aeruginosa biofilms. We then focused on a candidate matrix protein, the serine protease inhibitor ecotin (PA2755). This protein is able to inhibit neutrophil elastase, a bactericidal enzyme produced by the host immune system during P. aeruginosa biofilm infections. We show that ecotin binds to the key biofilm matrix exopolysaccharide Psl and that it can inhibit neutrophil elastase when associated with Psl. Finally, we show that ecotin protects both planktonic and biofilm P. aeruginosa cells from neutrophil elastase-mediated killing. This may represent a novel mechanism of protection for biofilms to increase their tolerance against the innate immune response. IMPORTANCE Proteins associated with the extracellular matrix of bacterial aggregates called biofilms have long been suggested to provide many important functions to the community. To date, however, only proteins that provide structural roles have been described, and few matrix-associated proteins have been identified. We developed a method to identify matrix proteins and characterized one. We show that this protein, when associated with the biofilm matrix, can inhibit a bactericidal enzyme produced by the immune system during infection and protect biofilm cells from death induced by the enzyme. This may represent a novel mechanism of protection for biofilms, further increasing their tolerance against the immune response. Together, our results are the first to show a nonstructural function for a confirmed matrix

  18. 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.

  19. Chemical sanitizers to control biofilms formed by two Pseudomonas species on stainless steel surface

    Directory of Open Access Journals (Sweden)

    Danila Soares Caixeta

    2012-03-01

    Full Text Available The biofilm formation of Pseudomonas aeruginosa and Pseudomonas fluorescens on AISI 304 stainless steel in the presence of reconstituted skim milk under different temperatures was conducted, and the potential of three chemical sanitizers in removing the mono-species biofilms formed was compared. Pseudomonas aeruginosa cultivated in skim milk at 28 °C presented better growth rate (10.4 log CFU.mL-1 when compared with 3.7 and 4.2 log CFU.mL-1 for P. aeruginosa and P. fluorescens cultivated at 7 °C, respectively. Pseudomonas aeruginosa formed biofilm when cultivated at 28 °C. However, only the adhesion of P. aeruginosa and P. fluorescens was observed when incubated at 7 °C. The sodium dichloroisocyanurate was the most efficient sanitizer in the reduction of the adhered P. aeruginosa cells at 7 and 28 °C and those on the biofilm, respectively. The hydrogen peroxide was more effective in the reduction of adhered cells of P. fluorescens at 7 °C.

  20. Efflux mediated adaptive and cross resistance to ciprofloxacin and benzalkonium chloride in Pseudomonas aeruginosa of dairy origin.

    Science.gov (United States)

    Pagedar, Ankita; Singh, Jitender; Batish, Virender K

    2011-06-01

    The present study was undertaken to investigate the role of efflux pump activity (EPA) in conferring adaptive and cross resistances against ciprofloxacin (CF) and benzalkonium chloride (BC) in dairy isolates of Pseudomonas aeruginosa. Biofilm formation potential was correlated with development of adaptive resistance in originally resistant strains. Irrespective of parent strains's susceptibility, isolates developed substantial adaptive resistance against CF and BC. Significant difference was observed in ability of non resistant isolates to develop adaptive resistance against CF and BC (P Reduction in adaptive resistances due to EPI was more evident in originally non resistant strains, which reaffirms EPA as probable mechanism of adaptive resistance. The present study perhaps first of its kind, suggests an active role of EPA in conferring adaptive and cross resistances in food related P. aeruginosa isolates and supports reverse hypothesis that antibiotic-resistant organisms eventually become tolerant to other antibacterial agents as well. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Solvent purification with high-porosity (macroreticular) ion-exchange resin

    International Nuclear Information System (INIS)

    McKibben, J.M.

    Numerous solvent degradation products exist in all of our process solvents that are not efficiently removed in the routine solvent washing operation. Tests indicate that a relatively new type of resin - variously called high-porosity, macroreticular, or macroporous resin - removes at least some of these persistent chemicals and substantially improves the quality of any TBP process solvent. A plant test is proposed for the purification of the first cycle solvent of the HM process, in which a loop will be installed to draw a small side stream of solvent from the washed solvent hold tank (904), pass it through a 2.7 ft 3 resin column, and return it to the same tank

  2. Anaerobic oxidation of 2-chloroethanol under denitrifying conditions by Pseudomonas stutzeri strain JJ.

    Science.gov (United States)

    Dijk, J A; Stams, A J M; Schraa, G; Ballerstedt, H; de Bont, J A M; Gerritse, J

    2003-11-01

    A bacterium that uses 2-chloroethanol as sole energy and carbon source coupled to denitrification was isolated from 1,2-dichloroethane-contaminated soil. Its 16 S rDNA sequence showed 98% similarity with the type strain of Pseudomonas stutzeri (DSM 5190) and the isolate was tentatively identified as Pseudomonas stutzeri strain JJ. Strain JJ oxidized 2-chloroethanol completely to CO(2) with NO(3)(- )or O(2) as electron acceptor, with a preference for O(2) if supplied in combination. Optimum growth on 2-chloroethanol with nitrate occurred at 30 degrees C with a mu(max) of 0.14 h(-1) and a yield of 4.4 g protein per mol 2-chloroethanol metabolized. Under aerobic conditions, the mu(max) was 0.31 h(-1). NO(2)(-) also served as electron acceptor, but reduction of Fe(OH)(3), MnO(2), SO(4)(2-), fumarate or ClO(3)(-) was not observed. Another chlorinated compound used as sole energy and carbon source under aerobic and denitrifying conditions was chloroacetate. Various different bacterial strains, including some closely related Pseudomonas stutzeri strains, were tested for their ability to grow on 2-chloroethanol as sole energy and carbon source under aerobic and denitrifying conditions, respectively. Only three strains, Pseudomonas stutzeri strain LMD 76.42, Pseudomonas putida US2 and Xanthobacter autotrophicus GJ10, grew aerobically on 2-chloroethanol. This is the first report of oxidation of 2-chloroethanol under denitrifying conditions by a pure bacterial culture.

  3. Development of Effective Solvent Modifiers for the Solvent Extraction of Cesium from Alkaline High-Level Tank Waste

    International Nuclear Information System (INIS)

    Bonnesen, Peter V.; Delmau, Laetitia H.; Moyer, Bruce A.; Lumetta, Gregg J.

    2003-01-01

    A series of novel alkylphenoxy fluorinated alcohols were prepared and investigated for their effectiveness as modifiers in solvents containing calix(4)arene-bis-(tert-octylbenzo)-crown-6 for extracting cesium from alkaline nitrate media. A modifier that contained a terminal 1,1,2,2-tetrafluoroethoxy group was found to decompose following long-term exposure to warm alkaline solutions. However, replacement of the tetrafluoroethoxy group with a 2,2,3,3-tetrafluoropropoxy group led to a series of modifiers that possessed the alkaline stability required for a solvent extraction process. Within this series of modifiers, the structure of the alkyl substituent (tert-octyl, tert-butyl, tert-amyl, and sec-butyl) of the alkylphenoxy moiety was found to have a profound impact on the phase behavior of the solvent in liquid-liquid contacting experiments, and hence on the overall suitability of the modifier for a solvent extraction process. The sec-butyl derivative(1-(2,2,3,3-tetrafluoropropoxy)-3- (4-sec-butylphenoxy)-2-propanol) (Cs-7SB) was found to possess the best overall balance of properties with respect to third phase and coalescence behavior, cleanup following degradation, resistance to solids formation, and cesium distribution behavior. Accordingly, this modifier was selected for use as a component of the solvent employed in the Caustic-Side Solvent Extraction (CSSX) process for removing cesium from high level nuclear waste (HLW) at the U.S. Department of Energy's (DOE) Savannah River Site. In batch equilibrium experiments, this solvent has also been successfully shown to extract cesium from both simulated and actual solutions generated from caustic leaching of HLW tank sludge stored in tank B-110 at the DOE's Hanford Site.

  4. Stochastic level-set variational implicit-solvent approach to solute-solvent interfacial fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shenggao, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Mathematical Center for Interdiscipline Research, Soochow University, 1 Shizi Street, Jiangsu, Suzhou 215006 (China); Sun, Hui; Cheng, Li-Tien [Department of Mathematics, University of California, San Diego, La Jolla, California 92093-0112 (United States); Dzubiella, Joachim [Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, 14109 Berlin, Germany and Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Li, Bo, E-mail: sgzhou@suda.edu.cn, E-mail: bli@math.ucsd.edu [Department of Mathematics and Quantitative Biology Graduate Program, University of California, San Diego, La Jolla, California 92093-0112 (United States); McCammon, J. Andrew [Department of Chemistry and Biochemistry, Department of Pharmacology, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, California 92093-0365 (United States)

    2016-08-07

    Recent years have seen the initial success of a variational implicit-solvent model (VISM), implemented with a robust level-set method, in capturing efficiently different hydration states and providing quantitatively good estimation of solvation free energies of biomolecules. The level-set minimization of the VISM solvation free-energy functional of all possible solute-solvent interfaces or dielectric boundaries predicts an equilibrium biomolecular conformation that is often close to an initial guess. In this work, we develop a theory in the form of Langevin geometrical flow to incorporate solute-solvent interfacial fluctuations into the VISM. Such fluctuations are crucial to biomolecular conformational changes and binding process. We also develop a stochastic level-set method to numerically implement such a theory. We describe the interfacial fluctuation through the “normal velocity” that is the solute-solvent interfacial force, derive the corresponding stochastic level-set equation in the sense of Stratonovich so that the surface representation is independent of the choice of implicit function, and develop numerical techniques for solving such an equation and processing the numerical data. We apply our computational method to study the dewetting transition in the system of two hydrophobic plates and a hydrophobic cavity of a synthetic host molecule cucurbit[7]uril. Numerical simulations demonstrate that our approach can describe an underlying system jumping out of a local minimum of the free-energy functional and can capture dewetting transitions of hydrophobic systems. In the case of two hydrophobic plates, we find that the wavelength of interfacial fluctuations has a strong influence to the dewetting transition. In addition, we find that the estimated energy barrier of the dewetting transition scales quadratically with the inter-plate distance, agreeing well with existing studies of molecular dynamics simulations. Our work is a first step toward the

  5. Process for hydrogenating coal and coal solvents

    Science.gov (United States)

    Tarrer, Arthur R.; Shridharani, Ketan G.

    1983-01-01

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260.degree. C. to 315.degree. C. in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275.degree. C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350.degree. C.

  6. COMPUTER-AIDED SOLVENT DESIGN FOR POLLUTION PREVENTION: PARIS II

    Science.gov (United States)

    Solvent substitution is an attractive way of elijminating the use of regulated solvents because it usually does not require major chanages in existing processes, equipment or operations. Successful solvent substitution is dependent on finding solvents that are as effective or be...

  7. Isolasi Dan Identifikasi Pseudomonas Dari Tanah Kebun Biologi Wamena Dan Uji Awal Sebagai Agen Biokontrol Fusarium*[the Isolation and Identification of Pseudomonas From the Wamena Biological Gardens Soil and Its Preliminary Test as Biocontrol Agent on Fusari

    OpenAIRE

    Latupapua, HJD; Nurhidayat, N

    2003-01-01

    Pseudomonas bacteria plays essential role in soil ecology such as decomposer and biological control. The bacteria were isolated on selective media and identified from five soil samples taken within area of Wamena Biological Gardens.There are six species Pseudomonas were indentified based on morphological characters and biochemical reaction.P. striata was found to be common in soil of the area.No pathogen Pseudomonas was indentified in all soil samples. Preliminary study on biological control ...

  8. Detection of extended spectrum β-lactamase in Pseudomonas spp. isolated from two tertiary care hospitals in Bangladesh

    Directory of Open Access Journals (Sweden)

    Begum Shahanara

    2013-01-01

    Full Text Available Abstract Background Extended spectrum ß-lactamases (ESBLs represent a major group of lactamases responsible for resistance, mostly produced by gram-negative bacteria, to newer generations of ß-lactam drugs currently being identified in large numbers worldwide. The present study was undertaken to see the frequency of ESBL producing Pseudomonas spp. isolated from six hundred clinical specimens (wound, pus, aural, urine, sputum, throat and other swabs collected over a period of three years from two tertiary care hospitals in Bangladesh. Findings Aerobic bacterial culture was performed on aseptically collected swabs and only growth of Pseudomonas was considered for further species identification and ESBL production along with serotyping of Pseudomonas aeruginosa. Antimicrobial susceptibility testing was carried out using the Kirby-Bauer agar diffusion method and ESBL production was detected on Mueller Hinton agar by double-disk synergy technique using Amoxicillin-Clavulanic acid with Ceftazidime, Cefotaxime, Ceftriaxone and Aztreonam. Culture yielded 120 Pseudomonas spp. and 82 of them were biochemically characterized for species. Pseudomonas aeruginosa was found to be the predominant (90.2% species. Of 82 isolates tested for ESBL, 31 (37.8% were ESBL positive with 29 (93.5% as Pseudomonas aeruginosa, the remaining 2 (6.5% were Stenotrophomonas maltophilia and Ralstonia pickettii. Antibiogram revealed Imipenem as the most effective drug (93.3% among all antimicrobials used against Pseudomonas spp. followed by Aminoglycosides (63.7%. Conclusion ESBL producing Pseudomonas spp. was found to be a frequent isolate from two tertiary care hospitals in Bangladesh, showing limited susceptibility to antimicrobials and decreased susceptibility to Imipenem in particular, which is a matter of great concern.

  9. Interaction between Pseudomonas and CXC Chemokines Increases Risk of Bronchiolitis Obliterans Syndrome and Death in Lung Transplantation

    Science.gov (United States)

    Wang, Xiaoyan; Weigt, S. Sam; Palchevskiy, Vyacheslav; Lynch, Joseph P.; Ross, David J.; Kubak, Bernard M.; Saggar, Rajan; Fishbein, Michael C.; Ardehali, Abbas; Li, Gang; Elashoff, Robert; Belperio, John A.

    2013-01-01

    Rationale: Pseudomonas aeruginosa is the most commonly isolated gram-negative bacterium after lung transplantation and has been shown to up-regulate glutamic acid–leucine–arginine–positive (ELR+) CXC chemokines associated with bronchiolitis obliterans syndrome (BOS), but the effect of pseudomonas on BOS and death has not been well defined. Objectives: To determine if the influence of pseudomonas isolation and ELR+ CXC chemokines on the subsequent development of BOS and the occurrence of death is time dependent. Methods: A three-state model was developed to assess the likelihood of transitioning from lung transplant (state 1) to BOS (state 2), from transplant (state 1) to death (state 3), and from BOS (state 2) to death (state 3). This Cox semi-Markovian approach determines state survival rates and cause-specific hazards for movement from one state to another. Measurements and Main Results: The likelihood of transition from transplant to BOS was increased by acute rejection, CXCL5, and the interaction between pseudomonas and CXCL1. The pseudomonas effect in this transition was due to infection rather than colonization. Movement from transplant to death was facilitated by pseudomonas infection and single lung transplant. Transition from BOS to death was affected by the length of time in state 1 and by the interactions between any pseudomonas isolation and CXCL5 and aspergillus, either independently or in combination. Conclusions: Our model demonstrates that common post-transplantation events drive movement from one post-transplantation state to another and influence outcomes differently depending upon when after transplantation they occur. Pseudomonas and the ELR+ CXC chemokines may interact to negatively influence lung transplant outcomes. PMID:23328531

  10. Exacerbation of bronchiectasis by Pseudomonas monteilii: a case report.

    Science.gov (United States)

    Aditi; Shariff, Malini; Beri, Kiran

    2017-07-24

    Pseudomonas spp are important opportunistic and nosocomial pathogens. One such species is Pseudomonas monteilii (P. monteilii). It has been described as an environmental contaminant and potential pathogen. We identified this organism as the causative agent of an exacerbation of bronchiectasis and an environmental contaminant in our hospital on two separate occasions. P. monteilii was the cause of an exacerbation of bronchiectasis in a 30-year-old HIV negative male. Patient presented with cough with sputum production and exertional dyspnea. The isolate was recovered from a sputum sample in significant counts and definitively identified by Matrix-Assisted Laser Desorption/Ionisation- Time of Flight Mass Spectrometry (MALDI-TOF MS). He was treated with piperacillin-tazobactam and recovered clinically and microbiologically. Another two isolates of the organism were contaminants from the hospital environment. The three isolates were susceptible to all tested antibiotics. Typing by Random amplification of polymorphic DNA (RAPD) found no clonal relationship between them. Less common species of Pseudomonas need to be identified accurately. This organism is identified by commonly used phenotypic systems as P. putida which may have contributed to a lower reported prevalence. P. monteilii is a known environmental contaminant and must also be considered as a potential pathogen, particularly in patients with chronic lung disease.

  11. Different Ancestries of R Tailocins in Rhizospheric Pseudomonas Isolates

    Science.gov (United States)

    Ghequire, Maarten G.K.; Dillen, Yörg; Lambrichts, Ivo; Proost, Paul; Wattiez, Ruddy; De Mot, René

    2015-01-01

    Bacterial genomes accommodate a variety of mobile genetic elements, including bacteriophage-related clusters that encode phage tail-like protein complexes playing a role in interactions with eukaryotic or prokaryotic cells. Such tailocins are unable to replicate inside target cells due to the lack of a phage head with associated DNA. A subset of tailocins mediate antagonistic activities with bacteriocin-like specificity. Functional characterization of bactericidal tailocins of two Pseudomonas putida rhizosphere isolates revealed not only extensive similarity with the tail assembly module of the Pseudomonas aeruginosa R-type pyocins but also differences in genomic integration site, regulatory genes, and lytic release modules. Conversely, these three features are quite similar between strains of the P. putida and Pseudomonas fluorescens clades, although phylogenetic analysis of tail genes suggests them to have evolved separately. Unlike P. aeruginosa R pyocin elements, the tailocin gene clusters of other pseudomonads frequently carry cargo genes, including bacteriocins. Compared with P. aeruginosa, the tailocin tail fiber sequences that act as specificity determinants have diverged much more extensively among the other pseudomonad species, mostly isolates from soil and plant environments. Activity of the P. putida antibacterial particles requires a functional lipopolysaccharide layer on target cells, but contrary to R pyocins from P. aeruginosa, strain susceptibilities surpass species boundaries. PMID:26412856

  12. Structure-activity relationships in the hydrolysis of substrates by the phosphotriesterase from Pseudomonas diminuta

    International Nuclear Information System (INIS)

    Donarski, W.J.; Dumas, D.P.; Heitmeyer, D.P.; Lewis, V.E.; Raushel, F.M.

    1989-01-01

    The mechanism and substrate specificity of the phosphotriesterase from Pseudomonas diminuta have been examined. The enzyme hydrolyzes a large number of phosphotriester substrates in addition to paraoxon (diethyl p-nitrophenyl phosphate) and its thiophosphate analogue, parathion. The two ethyl groups in paraoxon can be changed to propyl and butyl groups, but the maximal velocity and Km values decrease substantially. The enzyme will not hydrolyze phosphomonoesters or -diesters. There is a linear correlation between enzymatic activity and the pKa of the phenolic leaving group for 16 paraoxon analogues. The beta value in the corresponding Bronsted plot is -0.8. No effect on either Vmax or Vmax/Km is observed when sucrose is used to increase the relative solvent viscosity by 3-fold. These results are consistent with rate-limiting phosphorus-oxygen bond cleavage. A plot of log V versus pH for the hydrolysis of paraoxon shows one enzymatic group that must be unprotonated for activity with a pKa of 6.1. The deuterium isotope effect by D2O on Vmax and Vmax/Km is 2.4 and 1.2, respectively, and the proton inventory is linear, which indicates that only one proton is in flight during the transition state. The inhibition patterns by the products are consistent with a random kinetic mechanism

  13. Extraction, Scrub, and Strip Test Results for the Salt Waste Processing Facility Caustic Side Solvent Extraction Solvent Sample

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-06

    An Extraction, Scrub, and Strip (ESS) test was performed on a sample of Salt Waste Processing Facility (SWPF) Caustic-Side Solvent Extraction (CSSX) solvent and salt simulant to determine cesium distribution ratios (D(Cs)), and cesium concentration in the strip effluent (SE) and decontaminated salt solution (DSS) streams; this data will be used by Parsons to help determine if the solvent is qualified for use at the SWPF. The ESS test showed acceptable performance of the solvent for extraction, scrub, and strip operations. The extraction D(Cs) measured 12.5, exceeding the required value of 8. This value is consistent with results from previous ESS tests using similar solvent formulations. Similarly, scrub and strip cesium distribution ratios fell within acceptable ranges. This revision was created to correct an error. The previous revision used an incorrect set of temperature correction coefficients which resulted in slight deviations from the correct D(Cs) results.

  14. Spectroscopic and DFT study of solvent effects on the electronic absorption spectra of sulfamethoxazole in neat and binary solvent mixtures

    Science.gov (United States)

    Almandoz, M. C.; Sancho, M. I.; Blanco, S. E.

    2014-01-01

    The solvatochromic behavior of sulfamethoxazole (SMX) was investigated using UV-vis spectroscopy and DFT methods in neat and binary solvent mixtures. The spectral shifts of this solute were correlated with the Kamlet and Taft parameters (α, β and π*). Multiple lineal regression analysis indicates that both specific hydrogen-bond interaction and non specific dipolar interaction play an important role in the position of the absorption maxima in neat solvents. The simulated absorption spectra using TD-DFT methods were in good agreement with the experimental ones. Binary mixtures consist of cyclohexane (Cy)-ethanol (EtOH), acetonitrile (ACN)-dimethylsulfoxide (DMSO), ACN-dimethylformamide (DMF), and aqueous mixtures containing as co-solvents DMSO, ACN, EtOH and MeOH. Index of preferential solvation was calculated as a function of solvent composition and non-ideal characteristics are observed in all binary mixtures. In ACN-DMSO and ACN-DMF mixtures, the results show that the solvents with higher polarity and hydrogen bond donor ability interact preferentially with the solute. In binary mixtures containing water, the SMX molecules are solvated by the organic co-solvent (DMSO or EtOH) over the whole composition range. Synergistic effect is observed in the case of ACN-H2O and MeOH-H2O, indicating that at certain concentrations solvents interact to form association complexes, which should be more polar than the individual solvents of the mixture.

  15. Solvent sorting in (mixed solvent electrolyte) systems: Time-resolved ...

    Indian Academy of Sciences (India)

    lar solvents as an effective single component dipo- lar liquid that is characterized ... and time (t) dependent solvation energy of mobile dipo- lar solute with density ..... Even though this way for modification of C is purely ad- hoc, the observation ...

  16. Optimization of alkaline protease production from Pseudomonas ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... protease production was 37°C at pH 9, with 2% inoculum in the medium for 24 h. .... Positive. Catalase test. Positive ... The enzyme activity gradually decreases from ... Effect of temperature on protease production by Pseudomonas fluorescens. 0 .... between RNA polymerase and upstream promotes DNA.

  17. ADHESION OF PSEUDOMONAS-FLUORESCENS TO METALLIC SURFACES

    NARCIS (Netherlands)

    VIEIRA, MJ; OLIVEIRA, R; MELO, L; PINHEIRO, M; VANDERMEI, HC

    1992-01-01

    Deposition of Pseudomonas fluorescens on aluminium, brass and copper plates was studied in a flow system. The number of bacteria deposited on aluminium was greater than on the other two types of metals. The results are discussed in terms of the mechanisms (transport and/or adhesion) that may control

  18. Beta-1,4-Galactosyltransferase-catalyzed glycosylation of sugar derivatives: Modulation of the enzyme activity by alpha-lactalbumin, immobilization and solvent tolerance

    Czech Academy of Sciences Publication Activity Database

    Charvátová, Andrea; Rossi, C.; Petrásková, Lucie; Křen, Vladimír; Riva, S.; Monti, D.

    2006-01-01

    Roč. 39, - (2006), s. 98-104 ISSN 1381-1177 R&D Projects: GA MŠk OC D25.001; GA ČR GA203/05/0172 Institutional research plan: CEZ:AV0Z50200510 Keywords : enzymatic galactosylation * immobilization * organic solvent Subject RIV: EE - Microbiology, Virology Impact factor: 2.149, year: 2006

  19. Linear Alkylbenzene Sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents

    Directory of Open Access Journals (Sweden)

    I.T Kehinde

    2008-12-01

    Full Text Available The discharge of untreated detergent-bearing waste introduces linear alkylbenzene sulfonates (LAS to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were tested for tolerance to LAS using the media dilution technique. LAS-tolerance was indicated by growth of the bacteria in the presence of the surfactant. The pH, concentrations of surfactant, population of heterotrophic bacteria and population of LAS-tolerant bacteria in the sediments were determined. A direct relationship (r= 0.9124 was found between the alkaline conditions (pH= 8.2-12.0 and high surfactant concentrations (45-132 mg/g in the sediment. The sediments harboured a high population and a wide variety of bacteria; the populations of viable heterotrophic bacteria (vHB: 2.9×10(5 to 1.2×10(7 cfu/g and LAS tolerant bacteria (LTB: 1.5×10(4 to 1.2×10(6 cfu/g had a direct relationship (r= 0.9500. An inverse relationship resulted between each of them and the concentration of surfactant in the sediment, r vHB/ LAS = -0.9303 and rLTB/ LAS = -0.9143, respectively. Twelve bacteria species were isolated from the sediment: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia, Citrobacter freundii, Citrobacter diversus, Escherichia coli, Micrococcus luteus, Micrococcus albus, Pseudomonas putida, Pseudomonas stutzeri, Staphylococcus aureus and Streptococcus faecalis. Most of them were adapted to the surfactant with their maximum acceptable concentrations ranging between 0.03 and >1.0% (w/v. The sediments could serve as source of adapted organisms which can be used in bio-treatment of LAS-bearing waste. Rev. Biol. Trop. 56 (4:7-15. Epub 2008 December 12.La descarga de desechos que contienen detergentes liberan sulfonatos de alquibenceno lineal (LAS al

  20. Clinical utilization of genomics data produced by the international Pseudomonas aeruginosa consortium

    DEFF Research Database (Denmark)

    Freschi, Luca; Jeukens, Julie; Kukavica-Ibrulj, Irena

    2015-01-01

    The International Pseudomonas aeruginosa Consortium is sequencing over 1000 genomes and building an analysis pipeline for the study of Pseudomonas genome evolution, antibiotic resistance and virulence genes. Metadata, including genomic and phenotypic data for each isolate of the collection, are a...... implicated in human and animal infections, understand how patients become infected and how the infection evolves over time as well as identify prognostic markers for better evidence-based decisions on patient care....

  1. Pseudomonas aeruginosa Dose-Response and Bathing Water Infection

    Science.gov (United States)

    Pseudomonas aeruginosa is the most commonly identified opportunistic pathogen associated with pool acquired bather disease. To better understand why this microorganism poses this protracted problem we recently appraised P. aeruginosa pool risk management. Much is known about the ...

  2. Caenorhabditis elegans reveals novel Pseudomonas aeruginosa virulence mechanism

    NARCIS (Netherlands)

    Utari, Putri Dwi; Quax, Wim J.

    The susceptibility of Caenorhabditis elegans to different virulent phenotypes of Pseudomonas aeruginosa makes the worms an excellent model for studying host-pathogen interactions. Including the recently described liquid killing, five different killing assays are now available offering superb

  3. Chemical reactions in solvents and melts

    CERN Document Server

    Charlot, G

    1969-01-01

    Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

  4. 40 CFR 148.10 - Waste specific prohibitions-solvent wastes.

    Science.gov (United States)

    2010-07-01

    ... injection unless the solvent waste is a solvent-water mixture or solvent-containing sludge containing less... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-solvent wastes. 148.10 Section 148.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER...

  5. Compressed air-assisted solvent extraction (CASX) for metal removal.

    Science.gov (United States)

    Li, Chi-Wang; Chen, Yi-Ming; Hsiao, Shin-Tien

    2008-03-01

    A novel process, compressed air-assisted solvent extraction (CASX), was developed to generate micro-sized solvent-coated air bubbles (MSAB) for metal extraction. Through pressurization of solvent with compressed air followed by releasing air-oversaturated solvent into metal-containing wastewater, MSAB were generated instantaneously. The enormous surface area of MSAB makes extraction process extremely fast and achieves very high aqueous/solvent weight ratio (A/S ratio). CASX process completely removed Cr(VI) from acidic electroplating wastewater under A/S ratio of 115 and extraction time of less than 10s. When synthetic wastewater containing Cd(II) of 50mgl(-1) was treated, A/S ratios of higher than 714 and 1190 could be achieved using solvent with extractant/diluent weight ratio of 1:1 and 5:1, respectively. Also, MSAB have very different physical properties, such as size and density, compared to the emulsified solvent droplets, making separation and recovery of solvent from treated effluent very easy.

  6. In vitro efficacy of doripenem against pseudomonas aeruginosa and acinetobacter baumannii by e-test

    International Nuclear Information System (INIS)

    Gilani, M.; Munir, T.; Latif, M.; Rehman, S.

    2015-01-01

    To assess the in vitro efficacy of doripenem against Pseudomonas aeruginosa and Acinetobacter baumannii using Epsilometer strips. Study Design: Cross-sectional study. Place and Duration of Study: Department of Microbiology, Army Medical College, Rawalpindi and National University of Sciences and Technology, Islamabad, from May 2014 to September 2014. Methodology: A total of 60 isolates of Acinetobacter baumannii and Pseudomonas aeruginosa collected from various clinical samples received from Military Hospital were included in the study. The specimens were inoculated onto blood, MacConkey and chocolate agars. The isolates were identified using Gram staining, motility, catalase test, oxidase test and API 20NE (Biomeriux, France). Organisms identified as Acinetobacter baumannii and Pseudomonas aeruginosa were included in the study. Bacterial suspensions equivalent to 0.5 McFarland turbidity standard of the isolates were prepared and applied on Mueller Hinton agar. Epsilometer strip was placed in the center of the plate and incubated for 18-24 hours. Minimum Inhibitory Concentration (MIC) was taken to be the point where the epsilon intersected the E-strip. MIC of all the isolates was noted. Results: For Pseudomonas aeruginosa isolates, MIC50 was 12 micro g/mL and MIC90 was 32 micro g/mL. For Acinetobacter baumannii MIC 50 and MIC90 was 32 micro g/mL. Conclusion: Doripenem is no more effective against Pseudomonas aeruginosa and Acinetobacter baumannii in our setting. (author)

  7. The Pseudomonas aeruginosa PSL Polysaccharide Is a Social but Noncheatable Trait in Biofilms.

    Science.gov (United States)

    Irie, Yasuhiko; Roberts, Aled E L; Kragh, Kasper N; Gordon, Vernita D; Hutchison, Jaime; Allen, Rosalind J; Melaugh, Gavin; Bjarnsholt, Thomas; West, Stuart A; Diggle, Stephen P

    2017-06-20

    Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides population-level benefits in biofilms, for both growth and antibiotic tolerance; (iii) the benefits of PSL production are social and are shared with other cells; (iv) the benefits of PSL production appear to be preferentially directed toward cells which produce PSL; (v) cells which do not produce PSL are unable to successfully exploit cells which produce PSL. Taken together, this suggests that PSL is a social but relatively nonexploitable trait and that growth within biofilms selects for PSL-producing strains, even when multiple strains are on a patch (low relatedness at the patch level). IMPORTANCE Many studies have shown that bacterial traits, such as siderophores and quorum sensing, are social in nature. This has led to an impression that secreted traits act as public goods, which are costly to produce but benefit both the producing cell and its surrounding neighbors. Theories and subsequent experiments have shown that such traits are exploitable by asocial cheats, but we show here that this does not always hold true. We demonstrate that the Pseudomonas aeruginosa exopolysaccharide PSL provides social benefits to populations but that it is nonexploitable, because most of the fitness benefits accrue to PSL-producing cells. Our work builds on an increasing body of work showing that secreted traits can have both private and public

  8. Process for hydrogenating coal and coal solvents

    Energy Technology Data Exchange (ETDEWEB)

    Shridharani, K.G.; Tarrer, A.R.

    1983-02-15

    A novel process is described for the hydrogenation of coal by the hydrogenation of a solvent for the coal in which the hydrogenation of the coal solvent is conducted in the presence of a solvent hydrogenation catalyst of increased activity, wherein the hydrogenation catalyst is produced by reacting ferric oxide with hydrogen sulfide at a temperature range of 260/sup 0/ C to 315/sup 0/ C in an inert atmosphere to produce an iron sulfide hydrogenation catalyst for the solvent. Optimally, the reaction temperature is 275/sup 0/ C. Alternately, the reaction can be conducted in a hydrogen atmosphere at 350/sup 0/ C.

  9. Chitinase activity of Pseudomonas stutzeri PT5 in different fermentation condition

    Science.gov (United States)

    Chalidah, N.; Khotimah, I. N.; Hakim, A. R.; Meata, B. A.; Puspita, I. D.; Nugraheni, P. S.; Ustadi; Pudjiraharti, S.

    2018-03-01

    This study aimed to determine the incubation condition of Pseudomonas stutzeri PT5 in producing chitin degrading enzyme in various pH and temperatures; to compare the production of chitin degrading enzyme in chitin medium supplemented with additional nitrogen, carbon and a mixture of nitrogen and carbon sources and to observe the production of chitin degrading enzyme in 250 mL-shake flasks and 2 L-fermentor. The parameters tested during production were chitinase activity (U·mL-1) of culture supernatant and N-acetylglucosamine concentration (μg·mL-1) in the medium. The results showed that Pseudomonas stutzeri PT5 was able to produce the highest chitinase activity at pH 6 and temperature of 37 °C (0.024 U·mL-1). The addition of 0.1 % of ammonium phosphate and 0.1 % of maltose, increased the chitinase activity of Pseudomonas stutzeri PT5 by 3.24 and 8.08 folds, respectively, compared to the control. The addition of 0.1 % ammonium phosphate and 0.1 % maltose mixture to chitin medium resulted in the shorter time of chitinase production compared to the addition of sole nutrition. The production of chitinase using 2 L-fermentor shows that the highest chitinase activity produced by Pseudomonas stutzeri PT5 was reached at 1-day incubation (0.0283 U·mL-1), which was shorter than in 250 mL-shake flasks.

  10. Detection of Pseudomonas fluorescens from broth, water and ...

    African Journals Online (AJOL)

    sonal

    2015-04-08

    Apr 8, 2015 ... Author(s) agree that this article remains permanently open access under the terms of ... grown in nutrient broth overnight, pond water, mucus and kidney ... a rapid test for detection of Pseudomonas strains in milk is required.

  11. A computer-aided molecular design framework for crystallization solvent design

    DEFF Research Database (Denmark)

    Karunanithi, Arunprakash T.; Achenie, Luke E.K.; Gani, Rafiqul

    2006-01-01

    One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem is formu......One of the key decisions in designing solution crystallization processes is the selection of solvents. In this paper, we present a computer-aided molecular design (CAMD) framework for the design and selection of solvents and/or anti-solvents for solution crystallization. The CAMD problem...... solvent molecules. Solvent design and selection for two types of solution crystallization processes namely cooling crystallization and drowning out crystallization are presented. In the first case study, the design of single compound solvent for crystallization of ibuprofen, which is an important...

  12. Expression of Pseudomonas aeruginosa transposable phages in Pseudomonas putida cells. I. Establishment of lysogeny and lytic growth efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Gorbunova, S.A.; Yanenko, A.S.; Akhverdyan, V.Z.; Reulets, M.A.; Krylov, V.N.

    1986-03-01

    Expression of the genomes of Pseudomonas aeruginosa transposable phages (TP) in the cells of a heterologous host, P. putida PpGl, was studied. A high efficiency of TP lytic growth in PpGl cells was obtained both after zygotic induction following RP4::TP plasmid transfer and after thermoinduction of PpGl cells lysogenic for thermoinducible prophage D3112cts15. Characteristic for PpGl cells was a high TP yield (20-25 phage D3112cts15 particles per cell), which was evidence of a high level of TP transposition in cells of this species. The frequency of RP4::TP transfer into PpGl and PA01 cells was equal, but the lysogeny detection rat was somewhat lower in PpGl. Pseudomonas aeruginosa TP can integrate into the PpGl chromosome, producing inducible lysogens. The presence of RP4 is not necessary for the expression of the TP genome in PpGl cells. The D3112cts15 TP may be used for interspecific transduction of plasmids and chromosomal markers.

  13. Expression of Pseudomonas aeruginosa transposable phages in Pseudomonas putida cells. I. Establishment of lysogeny and lytic growth efficiency

    International Nuclear Information System (INIS)

    Gorbunova, S.A.; Yanenko, A.S.; Akhverdyan, V.Z.; Reulets, M.A.; Krylov, V.N.

    1986-01-01

    Expression of the genomes of Pseudomonas aeruginosa transposable phages (TP) in the cells of a heterologous host, P. putida PpGl, was studied. A high efficiency of TP lytic growth in PpGl cells was obtained both after zygotic induction following RP4::TP plasmid transfer and after thermoinduction of PpGl cells lysogenic for thermoinducible prophage D3112cts15. Characteristic for PpGl cells was a high TP yield (20-25 phage D3112cts15 particles per cell), which was evidence of a high level of TP transposition in cells of this species. The frequency of RP4::TP transfer into PpGl and PA01 cells was equal, but the lysogeny detection rat was somewhat lower in PpGl. Pseudomonas aeruginosa TP can integrate into the PpGl chromosome, producing inducible lysogens. The presence of RP4 is not necessary for the expression of the TP genome in PpGl cells. The D3112cts15 TP may be used for interspecific transduction of plasmids and chromosomal markers

  14. Nitrogen contribution proportion from soil, fertilizer and pseudomonas putida like in sorghum plantation on South Sumatra's inceptisols

    International Nuclear Information System (INIS)

    Kesumadewi, A.A.I.; Anas, Iswandi; Santosa, D.A.; Sisworo, Elsje L.

    2000-01-01

    The proportion of N which absorbed either from natural source (soil), N-fertilizer or N sub.2-fixing microorganism on sorghum plantation in marginal alang-alang lands that group to inceptisol should be studied in securing the soil fertility. In this experiment, N contribution of those N sources was determined during vegetative stage of sorghum on three subgroup of south sumatera's inceptisols. A greenhouse experiment that arranged in randomized complete block design using 2 factorial split plot was carried out in IPB Bogor from May-December 1998. The observation was focused on partition of N contribution from the soil, N-fertilizer and Pseudomonas putida like(N sub.2-fixing microorganism) on total plant-content 4 and 8 weeks after plantations (WAP). N-partition from those N-sources was done based o A-value method. Sorghum was absorb larger proportion of N from soil(63,36%-48,83% on 4 WAP and 64,58 % on WAP) than from fertilizer and P.putida like on all of the soil subgroups. Soil-N absorption was highest on oxic dystropept. Pseudomonas putida like was not able to subtite soil-N and fertilizer-N in sufficient amount to vigorous plant growth particularly on typica humitropept and typic dystropept. The microorganism was only provide a small amount of N to sorghum on oxic dystropept (23,05-23,95 % on 4 WAP and 15,91-34,44 % on 8WAP). The increment of plant root surface area could be enhance in greater extent of plant-N absorption than N sub.2-fixation. Thus, plantation of marginal tolerant sorghum still need addition of N-fertilizer

  15. Carbapenem stewardship: does ertapenem affect Pseudomonas susceptibility to other carbapenems? A review of the evidence.

    Science.gov (United States)

    Nicolau, David P; Carmeli, Yehuda; Crank, Christopher W; Goff, Debra A; Graber, Christopher J; Lima, Ana Lucia L; Goldstein, Ellie J C

    2012-01-01

    The group 2 carbapenems (imipenem, meropenem and, more recently, doripenem) have been a mainstay of treatment for patients with serious hospital infections caused by Pseudomonas aeruginosa, Enterobacteriaceae and other difficult-to-treat Gram-negative pathogens as well as mixed aerobic/anaerobic infections. When ertapenem, a group 1 carbapenem, was introduced, questions were raised about the potential for ertapenem to select for imipenem- and meropenem-resistant Pseudomonas. Results from ten clinical studies evaluating the effect of ertapenem use on the susceptibility of Pseudomonas to carbapenems have uniformly shown that ertapenem use does not result in decreased Pseudomonas susceptibility to these antipseudomonal carbapenems. Here we review these studies evaluating the evidence of how ertapenem use affects P. aeruginosa as well as provide considerations for ertapenem use in the context of institutional stewardship initiatives. Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  16. Permeability of commercial solvents through living human skin

    DEFF Research Database (Denmark)

    Ursin, C; Hansen, C M; Van Dyk, J W

    1995-01-01

    A procedure has been developed for measuring the steady state rate of permeation of commercial solvents through living human skin. To get the most consistent results, it was necessary with some solvents to normalize the solvent permeation rate of a given skin sample with its [3H]water permeation...... rate. For other solvents this was not necessary, so the un-normalized data were used. High [3H]water permeation rate also was used as a criterion for "defective" skin samples that gave erroneous permeability rates, especially for solvents having slow permeability. The linearity of the steady state data...... was characterized by calculation of the "percent error of the slope." The following permeability rates (g/m2h) of single solvents were measured: dimethyl sulfoxide (DMSO), 176; N-methyl-2-pyrrolidone, 171; dimethyl acetamide, 107; methyl ethyl ketone, 53; methylene chloride, 24; [3H]water, 14.8; ethanol, 11...

  17. Biosurfactants in plant-Pseudomonas interactions and their importance to biocontrol.

    Science.gov (United States)

    D'aes, Jolien; De Maeyer, Katrien; Pauwelyn, Ellen; Höfte, Monica

    2010-06-01

    Production of biosurfactants is a common feature in bacteria, and in particular in plant-associated species. These bacteria include many plant beneficial and plant pathogenic Pseudomonas spp., which produce primarily cyclic lipopeptide and rhamnolipid type biosurfactants. Pseudomonas-derived biosurfactants are involved in many important bacterial functions. By modifying surface properties, biosurfactants can influence common traits such as surface motility, biofilm formation and colonization. Biosurfactants can alter the bio-availability of exogenous compounds, such as nutrients, to promote their uptake, and of endogenous metabolites, including phenazine antibiotics, resulting in an enhanced biological activity. Antibiotic activity of biosurfactants towards microbes could play a role in intraspecific competition, self-defence and pathogenesis. In addition, bacterial surfactants can affect plants in different ways, either protecting them from disease, or acting as a toxin in a plant-pathogen interaction. Biosurfactants are involved in the biocontrol activity of an increasing number of Pseudomonas strains. Consequently, further insight into the roles and activities of surfactants produced by bacteria could provide means to optimize the use of biological control as an alternative crop protection strategy. © 2009 Society for Applied Microbiology and Blackwell Publishing Ltd.

  18. Utilization of petroleum hydrocarbons by Pseudomonas sp. and ...

    African Journals Online (AJOL)

    pseudomonas isolated from a petroleum-contaminated soil was instable. In this work, t is shown that when the isolates are immobilized on Perlite, they are more stable for oil egradation. Although the isolate did not have any chemotaxis to ...

  19. Radiation destruction of vitamin A in lipid solvents

    International Nuclear Information System (INIS)

    Snauwaert, F.; Maes, E.; Tobback, P.; Bhushan, B.

    1978-01-01

    The radiation response of vitamin A alcohol and its acetate derivative was compared in different lipid solvents. In all the solvents vitamin A alcohol exhibited a much higher radiation sensitivity than its ester counterpart. The nature of the solvent and the initial concentration was found to have a great influence on the extent of radiation degradation of vitamin A alcohol. In contrast to a high radiolability in non-polar solvents, vitamin A alcohol exhibited a remarkable stability in isopropanol. In addition, in isopropanol the G(-) relationship with radiation dose showed a reverse trend to that observed for other solvents. A thin-layer chromatographic procedure was developed for separation of the radiation degradation products. (author)

  20. Aderência in vitro do Staphylococcus epidermidis e da Pseudomonas alcaligenes em lentes intra-oculares In vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to intraocular lenses

    Directory of Open Access Journals (Sweden)

    Patrícia Ioschpe Gus

    2006-06-01

    Full Text Available OBJETIVO: Quantificar e comparar a aderência in vitro das bactérias Staphylococcus epidermidis e Pseudomonas alcaligenes em diferentes tipos de lentes intra-oculares (LIOs. MÉTODOS: Quatorze lentes intra-oculares foram usadas no experimento. Quatro de polimetilmetacrilato (PMMA, quatro de silicone, quatro de hidrogel e duas de acrílico. Oito lentes intra-oculares foram colocadas em oito tubos de ensaio contendo 4 ml de suspensão de Pseudomonas alcaligenes, e seis lentes intra-oculares foram colocadas em seis tubos de ensaio contendo 4 ml de suspensão de Staphylococcus epidermidis. A concentração do caldo utilizada para o teste de aderência foi de 10(8 unidades formadoras de colônias por mililitro (CFU/mL que corresponde a 0,5 na escala de McFarland. As lentes foram incubadas a 37° por duas horas. Após, foram removidas dos caldos e enxaguadas em água destilada estéril por duas vezes. As lentes foram cultivadas em placas de ágar-sangue a 35-37° e evaliadas a cada 24h por um período de 72h. Nas amostras que tiveram crescimento bacteriano, foram contadas as colônias utilizando os métodos convencionais de laboratório. Todos os ensaios foram executados em duplicata. RESULTADOS: A aderência do Staphylococcus epidermidis nas lentes de PMMA foi menor se comparada com as de silicone e de hidrogel. A aderência daPseudomonas alcaligenes nas lentes de hidrogel foi menor se comparada com as de silicone, PMMA e acrílico. CONCLUSÃO: Os resultados sugerem que a aderência do Staphylococcus epidermidis e da Pseudomonas alcaligenes nas lentes intra-oculares é influenciada pelo tipo de material da lente e pela espécie do microorganismo. A aderência bacteriana pode ter papel importante na patogenicidade da endoftalmite pós-cirurgia de catarata.PURPOSE: To quantify and compare the in vitro adherence of Staphylococcus epidermidis and Pseudomonas alcaligenes to different intraocular lenses (IOLs. METHODS: Fourteen intraocular lenses were

  1. Solvent extraction studies in miniature centrifugal contactors

    International Nuclear Information System (INIS)

    Siczek, A.A.; Meisenhelder, J.H.; Bernstein, G.J.; Steindler, M.J.

    1980-01-01

    A miniature short-residence-time centrifugal solvent extraction contactor and an eight-stage laboratory minibank of centrifugal contactors were used for testing the possibility of utilizing kinetic effects for improving the separation of uranium from ruthenium and zirconium in the Purex process. Results of these tests showed that a small improvement found in ruthenium and zirconium decontamination in single-stage solvent extraction tests was lost in the multistage extraction tests- in fact, the extent of saturation of the solvent by uranium, rather than the stage residence time, controlled the extent of ruthenium and zirconium extraction. In applying the centrifugal contactor to the Purex process, the primary advantages would be less radiolytic damage to the solvent, high troughput, reduced solvent inventory, and rapid attainment of steady-state operating conditions. The multistage mini contactor was also tested to determine the suitability of short-residence-time contactors for use with the Civex and Thorex processes and was found to be compatible with the requirements of these processes. (orig.) [de

  2. Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2012-06-01

    Full Text Available Abstract Background Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. Results A bacterial laccase (WlacD was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG 25 and diazo-dye Acid Red (AR 18. The results showed that decolorization of both dyes is Cu2+- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l with relative decolorization values of 91.2% (3 h and 97.1% (18 h, as well as high activity to AR18 (1 g/l by 80.5% (3 h and 89.0% (18 h, was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l. No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved

  3. Highly efficient and enzymatic regioselective undecylenoylation of gastrodin in 2-methyltetrahydrofuran-containing systems.

    Science.gov (United States)

    Yang, Rongling; Liu, Xueming; Chen, Zhiyi; Yang, Chunying; Lin, Yaosheng; Wang, Siyuan

    2014-01-01

    Highly efficient and regioselective acylation of pharmacologically interesting gastrodin with vinyl undecylenic acid has been firstly performed through an enzymatic approach. The highest catalytic activity and regioselectivity towards the acylation of 7'-hydroxyl of gastrodin was obtained with Pseudomonas cepacia lipase. In addition, it was observed the lipase displayed higher activity in the eco-friendly solvent 2-methyltetrahydrofuran-containing systems than in other organic solvents. In the co-solvent mixture of tetrahydrofuran and 2-methyltetrahydrofuran (3/1, v/v), the reaction rate was 60.6 mM/h, substrate conversion exceeded 99%, and 7'-regioselectivity was 93%. It was also interesting that the lipase-catalyzed acylation couldn't be influenced by the benzylic alcohol in gastrodin. However, pseudomonas cepacia lipase displayed different regioselectivity towards gastrodin and arbutin.

  4. Green solvents and technologies for oil extraction from oilseeds

    OpenAIRE

    Kumar, S. P. Jeevan; Prasad, S. Rajendra; Banerjee, Rintu; Agarwal, Dinesh K.; Kulkarni, Kalyani S.; Ramesh, K. V.

    2017-01-01

    Oilseeds are crucial for the nutritional security of the global population. The conventional technology used for oil extraction from oilseeds is by solvent extraction. In solvent extraction, n-hexane is used as a solvent for its attributes such as simple recovery, non-polar nature, low latent heat of vaporization (330?kJ/kg) and high selectivity to solvents. However, usage of hexane as a solvent has lead to several repercussions such as air pollution, toxicity and harmfulness that prompted to...

  5. 40 CFR 180.1261 - Xanthomonas campestris pv. vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages.

    Science.gov (United States)

    2010-07-01

    ... and Pseudomonas syringae pv. tomato specific Bacteriophages. 180.1261 Section 180.1261 Protection of.... vesicatoria and Pseudomonas syringae pv. tomato specific Bacteriophages. An exemption from the requirement of... syringae pv. tomato specific bacteriophages in or on pepper and tomato. [74 FR 26536, June 3, 2009] ...

  6. Effect of Iron Availability on Induction of Systemic Resistance to Fusarium Wilt of Chickpea by Pseudomonas spp.

    Science.gov (United States)

    Saikia, Ratul; Srivastava, Alok K; Singh, Kiran; Arora, Dilip K; Lee, Min-Woong

    2005-03-01

    Selected isolates of Pseudomonas fluorescens (Pf4-92 and PfRsC5) and P. aeruginosa (PaRsG18 and PaRsG27) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. Significant increase in plant height was observed in Pseudomonas treated plants. However, plant growth was inhibited when isolates of Pseudomonas were used in combination with Fusarium oxysporum f. sp. ciceri (FocRs1). It was also observed that the Pseudomonas spp. was colonized in root of chickpea and significantly suppressed the disease in greenhouse condition. Rock wool bioassay technique was used to study the effect of iron availability on the induction of systemic resistance to Fusarium wilt of chickpea mediated by the Pseudomonas spp. All the isolates of Pseudomonas spp. showed greater disease control in the induced systemic resistance (ISR) bioassay when iron availability in the nutrient solution was low. High performance liquid chromatography (HPLC) analysis indicated that all the bacterial isolates produced more salicylic acid (SA) at low iron (10µM EDDHA) than high iron availability (10µFe(3+) EDDHA). Except PaRsG27, all the three isolates produced more pseudobactin at low iron than high iron availability.

  7. Potential applications of Pseudomonas sp. (strain CPSB21) to ameliorate Cr6+ stress and phytoremediation of tannery effluent contaminated agricultural soils.

    Science.gov (United States)

    Gupta, Pratishtha; Rani, Rupa; Chandra, Avantika; Kumar, Vipin

    2018-03-20

    Contamination of agricultural soil with heavy metals has become a serious concern worldwide. In the present study, Cr 6+ resistant plant growth promoting Pseudomonas sp. (strain CPSB21) was isolated from the tannery effluent contaminated agricultural soils and evaluated for the plant growth promoting activities, oxidative stress tolerance, and Cr 6+ bioremediation. Assessment of different plant growth promotion traits, such as phosphate solubilization, indole-3-acetic acid production, siderophores, ammonia and hydrogen cyanide production, revealed that the strain CPSB21 served as an efficient plant growth promoter under laboratory conditions. A pot experiment was performed using sunflower (Helianthus annuus L.) and tomato (Solanum lycopersicum L.) as a test crop. Cr 6+ toxicity reduced plant growth, pigment content, N and P uptake, and Fe accumulation. However, inoculation of strain CPSB21 alleviated the Cr 6+ toxicity and enhanced the plant growth parameters and nutrient uptake. Moreover, Cr toxicity had varied response on oxidative stress tolerance at graded Cr 6+ concentration on both plants. An increase in superoxide dismutase (SOD) and catalase (CAT) activity and reduction in malonialdehyde (MDA) was observed on inoculation of strain CPSB21. Additionally, inoculation of CPSB21 enhanced the uptake of Cr 6+ in sunflower plant, while no substantial enhancement was observed on inoculation in tomato plant.

  8. A comparative study on the effect of solvent on nucleophilic fluorination with [18F]fluoride. Protic solvents as co-solvents in SN2 and SNAr reactions

    International Nuclear Information System (INIS)

    Koivula, T.; Simecek, J.; Jalomaeki, J.; Helariutta, K.; Airaksinen, A.J.

    2011-01-01

    The effect of solvent on nucleophilic substitution with cyclotron-produced [ 18 F]fluoride was studied in polar aprotic (CH 3 CN and DMF) and protic solvent (t-BuOH and t-amyl alcohol) mixtures (CH 3 CN/co-solvent, 2:8) in a series of model compounds, 4-(R 1 -methyl)benzyl R 2 -benzoates, using a K2.2.2/[ 18 F]KF phase transfer system (R 1 = -Cl, -OMs or -OH; R 2 = -Cl, -I or -NO 2 ). 18 F-fluorination of compounds 1-3, with chloride or mesylate as a leaving group in the benzylic position (R 1 ), afforded the desired 4-([ 18 F]fluoromethyl)benzyl analogues in all solvents during 15 min reaction time. The highest radiochemical yields (RCY) in all the studied reaction temperatures (80, 120 and 160 C) were achieved in CH 3 CN. Radiochemical yields in protic solvents were comparable to RCY in CH 3 CN only with the sulfonate ester 3 as a starting material. 18 F-Fluorination of the benzylic halides 1 and 2 was not promoted in the same extent; in addition, labelled side-products were detected at higher reaction temperatures. Radiofluorination in tert-alcohols was also studied using [ 18 F]CsF with and without added phase transfer catalyst, resulting in both conditions lower RCY when compared to K2.2.2/[ 18 F]KF system. Protic solvents were not able to promote aromatic 18 F-fluorination. 18 F-Fluorination of compound 5, having para-activated nitro group in the aromatic position (R 2 ), failed in tert-alcohols even at the highest temperature, but it was labelled successfully in DMF and to some extent in CH 3 CN. (orig.)

  9. Spreadsheet algorithm for stagewise solvent extraction

    International Nuclear Information System (INIS)

    Leonard, R.A.; Regalbuto, M.C.

    1994-01-01

    The material balance and equilibrium equations for solvent extraction processes have been combined with computer spreadsheets in a new way so that models for very complex multicomponent multistage operations can be setup and used easily. A part of the novelty is the way in which the problem is organized in the spreadsheet. In addition, to facilitate spreadsheet setup, a new calculational procedure has been developed. The resulting Spreadsheet Algorithm for Stagewise Solvent Extraction (SASSE) can be used with either IBM or Macintosh personal computers as a simple yet powerful tool for analyzing solvent extraction flowsheets. 22 refs., 4 figs., 2 tabs

  10. Peptidoglycan transpeptidase inhibition in Pseudomonas aeruginosa and Escherichia coli by Penicillins and Cephalosporins.

    Science.gov (United States)

    Moore, B A; Jevons, S; Brammer, K W

    1979-04-01

    Peptidoglycan transpeptidase activity has been studied in cells of Escherichia coli 146 and Pseudomonas aeruginosa 56 made permeable to exogenous, nucleotide-sugar peptidoglycan precursors by ether treatment. Transpeptidase activity was inhibited, in both organisms, by a range of penicillins and cephalosporins, the Pseudomonas enzyme being more sensitive to inhibition in each case. Conversely, growth of E. coli 146 was more susceptible to these antibiotics than growth of P. aeruginosa 56. Furthermore, similar transpeptidase inhibition values were ob-obtained for the four penicillins examined against the Pseudomonas enzyme, although only two of these (carbenicillin and pirbenicillin) inhibited the growth of this organism. We therefore conclude that the high resistance of P. aeruginosa 56 to growth inhibition by most beta-lactam antibiotics cannot be due to an insensitive peptidoglycan transpeptidase.

  11. Method of removing deterioration product in hydrocarbon type solvent

    International Nuclear Information System (INIS)

    Ito, Yoshifumi; Takashina, Toru; Murasawa, Kenji.

    1988-01-01

    Purpose: To remarkably reduce radioactive wastes by bringing adsorbents comprising titanium oxide and/or zirconium oxide into contact with hydrocarbon type solvents. Method: In a nuclear fuel re-processing step, an appropriate processing is applied to extraction solvents suffering from radioactive degradation, to separate the hydrocarbon solvents and store them in a solvent tank. Then, titanium oxide and/or zirconium oxide adsorbents are continuously mixed and agitated therewith to adsorb degradation products on the adsorbents. Then, they are introduced with adsorbent separators to recover purified hydrocarbon type solvents. Meanwhile, the separated adsorbents are discharged from pipeways. This enables to regenerate the hydrocarbon type solvents for reuse, as well as remarkably reduce the radioactive wastes. (Takahashi, M.)

  12. Hazardous Solvent Substitution Data System reference manual

    International Nuclear Information System (INIS)

    Branham-Haar, K.A.; Twitchell, K.E.

    1993-07-01

    Concern for the environment, in addition to Federal regulation, mandate the replacement of hazardous solvents with safer cleaning agents. Manufacturers are working to produce these replacement solvents. As these products are developed, potential users need to be informed of their availability. To promote the use of these new products instead of traditional solvents, the Idaho National Engineering Laboratory (INEL) has developed the Hazardous Solvent Substitution Data System (HSSDS). The HSSDS provides a comprehensive system of information on alternatives to hazardous solvents and related subjects, and it makes that information available to solvent users, industrial hygienists, and process engineers. The HSSDS uses TOPIC reg-sign, a text retrieval system produced by Verity, Inc., to allow a user to search for information on a particular subject. TOPIC reg-sign produces a listing of the retrieved documents and allows the use to examine the documents individually and to use the information contained in them. This reference manual does not replace the comprehensive TOPIC reg-sign user documentation (available from Verity, Inc.), or the HSSDS Tutorial (available from the INEL). The purpose of this reference manual is to provide enough instruction on TOPIC reg-sign so the user may begin accessing the data contained in the HSSDS

  13. Re-Refining of Waste Lubricating Oil by Solvent Extraction

    Directory of Open Access Journals (Sweden)

    Hassan Ali Durrani

    2011-04-01

    Full Text Available Re-refining of waste lubricating oil by solvent extraction is one of the potential techniques. The advantages of solvent extraction technique practically offers from environmental and economic points of view have received due attention. In this paper selection of composite solvent and technique to upgrade the used lubricant oil into base oil has been made. The composite solvent 2-propanol, 1-butanol and butanone have two alcohols that make a binary system reasonably effective. This work also attempts to study the performance of the composite solvent in the extraction process for recovering waste lubricating oil. The key parameters considered were vacuum pressure, temperature and the weight ratio of solvent to waste lubricating oil. The performance was investigated on the PSR (Percentage Sludge Removal and POL (Percent Oil Loss. The best results were obtained using composite solvent 25% 2-propanol, 37% 1-butanol and 38% butanone by a solvent to oil ratio of 6:1 at vacuum pressure 600mmHg and distillation temperature 250oC. The vacuum distilled oil pretreated with the composite solvents was matched to the standard base oil 500N and 150N, found in close agreement and could be used for similar purpose.

  14. Detection of Pseudomonas fluorescens from broth, water and ...

    African Journals Online (AJOL)

    Loop mediated isothermal amplification is rapid, highly sensitive and specifically developed method for detection of bacterial infections. AprX gene for alkaline metalloprotease of Pseudomonas fluorescens was used to design four primers and loop mediated isothermal amplification (LAMP) conditions were standardized for ...

  15. Effects of the Consortium of Pseudomonas, Bacillus and ...

    African Journals Online (AJOL)

    The effect of the consortium of Pseudomonas, Bacillus and Micrococcus spp on polycyclic aromatic hydrocarbons in crude oil was carried out using standard microbiological methods. Spectrophotometer, gas chromatography and viable count which determined the optical density, the polycyclic aromatic hydrocarbons and ...

  16. Production of a rhamnolipid-type biosurfactant by Pseudomonas ...

    African Journals Online (AJOL)

    The work herewith investigated the effect of the culture medium composition on rhamnolipid production by Pseudomonas aeruginosa LBM10, previously isolated from an estuarine environment in Southern Brazil. Experimental design and surface response methodology were used in order to improve biosurfactant ...

  17. Nonhazardous solvent composition and method for cleaning metal surfaces

    International Nuclear Information System (INIS)

    Googin, J.M.; Simandl, R.F.; Thompson, L.M.

    1993-01-01

    A solvent composition for displacing greasy and oily contaminants as well as water and/or aqueous residue from metallic surfaces, especially surfaces of radioactive materials so that such surfaces can be wiped clean of the displaced contaminants, water and/or aqueous residue. The solvent composition consists essentially of a blend of nonpolar aliphatic hydrocarbon solvent having a minimum flash point of about 140 F and 2 to 25 volume percent of a polar solvent having a flash point sufficiently high so as to provide the solvent composition with a minimum flash point of at least 140 F. The solvent composition is nonhazardous so that when it is used to clean the surfaces of radioactive materials the waste in the form of paper or cloth wipes, lab coats and the like used in the cleaning operation is not considered to be mixed waste composed of a hazardous solvent and a radioactive material

  18. Supercritical solvent extraction of oil sand bitumen

    Science.gov (United States)

    Imanbayev, Ye. I.; Ongarbayev, Ye. K.; Tileuberdi, Ye.; Mansurov, Z. A.; Golovko, A. K.; Rudyk, S.

    2017-08-01

    The supercritical solvent extraction of bitumen from oil sand studied with organic solvents. The experiments were performed in autoclave reactor at temperature above 255 °C and pressure 29 atm with stirring for 6 h. The reaction resulted in the formation of coke products with mineral part of oil sands. The remaining products separated into SARA fractions. The properties of the obtained products were studied. The supercritical solvent extraction significantly upgraded extracted natural bitumen.

  19. Sustainable development of gree solvent separation process

    OpenAIRE

    Lisickov, Kiril; Fidancevska, Emilija; Grujic, Radoslav; Srebrenkoska, Vineta; Kuvendziev, Stefan

    2011-01-01

    Solvents defi ne a major part of the environmental performance of processes in the chemical industry and impact on cost, safety and health issues. The idea of green solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production. In spite of conventional separation methods, precise process green technologies are based on the application of modern processes and process equipment as well as control and management...

  20. 19F NMR spectroscopy in monitoring fluorinated-solvent regeneration

    International Nuclear Information System (INIS)

    Ogorodnikov, V.D.; Bordunov, V.V.

    1987-01-01

    Extensive use is made of solvents such as trichloroethylene, freon-133, and perchloroethylene because they are good solvents for inorganic, plant, and animal greases, while the solvents can be recovered and there is no fire hazard. In this paper, the authors examined methods to monitor spent solution regeneration rapidly and with high accuracy. The authors tested perfluorinated telomeric alcohols as solvents for cleaning engineering components which have melting points of 60-120 degrees celsius. The higher working temperatures and the increased energy consumption are disadvantages of these solvents, but these are compensated for by the scope for using them virtually in the solid, liquid, and vapor states. The authors' proposed technology is based on solvents with melting points over 40 degrees celsius which produce virtually no wastes. The telomeric alcohols are recovered after cooling to normal conditions by separation from the oil by filtration and centrifugation, and they can be used in the next purification cycle. When the solvents have been regenerated, the petroleum products such as industrial oils can be reused for their original purpose. However, quantitative data are required on the solvent contents in the oil and the oil contents in the solvent in order to determine the degree of regeneration and the modes to be used. The authors have also proposed a quantitative method of determining traces of these alcohols in oils and residual oils in the solvent by fluorine NMR. All measurements were made with a BS497 NMR spectrometer