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

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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.

Combinatorial efficacy of Trichoderma spp. and Pseudomonas fluorescens to enhance suppression of cell wall degrading enzymes produced by Fusarium wilt of Arachis hypogaea.L

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P Rajeswari

2017-12-01

Full Text Available Fusarium oxysporum, the soil borne pathogen causes vascular wilt, on majority of crop plants. It has been demonstrated that two different species of Trichoderma and Pseudomonas fluorescens suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol agents, and thus of several suppressive mechanisms, may represent a viable control strategy. A necessity for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between Trichoderma spp. and Pseudomonas fluorescens that have the ability to suppress Fusarium oxysporum in vitro on the activity of pectinolytic enzymes of Fusarium oxysporum. The activity of pectinolytic enzymes, i.e. pectin methyl esterase, endo and exo polymethylgalacturonases and exo and endo pectin trans eliminases produced by Fusarium oxysporum (Control was higher. Maximum inhibition of pectin methylesterase, exo and endo polymethylgalacturonase and exo and endopectin trans eliminase was shown by culture filtrate of Trichoderma viride + Pseudomonas fluorescens (Tv+Pf (1+2%, followed by Trichoderma harzianum + Pseudomonas fluorescens, (Th +Pf (1.5+2% and Trichoderma viride + Trichoderma harzianum (Tv+Th (1+1.5%. However, pathogenecity suppression of Fusarium oxysporum, a causative of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2% was significantly better as compared to the single bio-agent. This indicates that specific interactions between biocontrol agents influence suppression of pathogenicity factors directly by combinations of these compatible bio-agents.

SANITATION PROCESS OPTIMALIZATION IN RELATION TO THE MICROBIAL BIOFILM OF PSEUDOMONAS FLUORESCENS

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Vladimír Vietoris

2012-02-01

Full Text Available Biofilms have been of considerable interest in the context of food hygiene. Extracellular polymeric substances play an important role in the attachment and colonization of microorganisms to food-contact surfaces. If the microorganisms from food-contact surfaces are not completely removed, they may lead to biofilm formation and also increase the biotransfer potential. The experimental part was focused on the adhesion of bacterial cells under static conditions and testing the effectiveness of disinfectants on created biofilm. In laboratory conditions we prepared and formed the bacterial biofilms Pseudomonas fluorescens in the test surfaces of stainless steel. Over the 72 hours and the next 72 hours were observed numbers of adhesion bacterial cells of Pseudomonas fluorescens on solid surfaces of tested materials.

Improved Performance of Pseudomonas fluorescens lipase by covalent immobilization onto Amberzyme

NARCIS (Netherlands)

Aslan, Yakup; Handayani, Nurrahmi; Stavila, Erythrina; Loos, Katja

2013-01-01

Objective: In this study, the conditions of covalent immobilization of Pseudomonas fluorescens lipase onto an oxirane-activated support (Amberzyme) were optimized to obtain a high activity yield. Furthermore, the operational and storage stabilities of immobilized lipase were tested. Methods: Optimum

Effect of Pseudomonas fluorescens on Buried Steel Pipeline Corrosion.

Science.gov (United States)

Spark, Amy J; Law, David W; Ward, Liam P; Cole, Ivan S; Best, Adam S

2017-08-01

Buried steel infrastructure can be a source of iron ions for bacterial species, leading to microbiologically influenced corrosion (MIC). Localized corrosion of pipelines due to MIC is one of the key failure mechanisms of buried steel pipelines. In order to better understand the mechanisms of localized corrosion in soil, semisolid agar has been developed as an analogue for soil. Here, Pseudomonas fluorescens has been introduced to the system to understand how bacteria interact with steel. Through electrochemical testing including open circuit potentials, potentiodynamic scans, anodic potential holds, and electrochemical impedance spectroscopy it has been shown that P. fluorescens increases the rate of corrosion. Time for oxide and biofilms to develop was shown to not impact on the rate of corrosion but did alter the consistency of biofilm present and the viability of P. fluorescens following electrochemical testing. The proposed mechanism for increased corrosion rates of carbon steel involves the interactions of pyoverdine with the steel, preventing the formation of a cohesive passive layer, after initial cell attachment, followed by the formation of a metal concentration gradient on the steel surface.

Survival of a Rifampicin-Resistant Pseudomonas fluorescens Strain in Nine Mollisols

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Tami L. Stubbs

2014-01-01

Full Text Available Pseudomonas fluorescens strain D7 (P.f. D7 is a naturally occurring soil bacterium that shows promise as a biological herbicide to inhibit growth of annual grass weeds, including downy brome (Bromus tectorum L., in crop- and rangelands. Pseudomonas fluorescens strain D7rif (P.f. D7rif is a rifampicin-resistant strain of P.f. D7. One of the greatest obstacles to successful biological weed control is survival of the organism under field conditions. Nine soils in the taxonomic order of Mollisols, collected from downy brome-infested areas of the Western and Central United States, were inoculated with P.f. D7rif and incubated in the laboratory to determine the effects of soil type, soil properties, incubation temperature, and soil water potential on survival of P.f. D7rif over 63 days. Silt loam soils from Lind, Washington, and Moro, Oregon, sustained the highest P.f. D7rif populations, and recovery was the lowest from Pendleton, Oregon soil. Survival and recovery of P.f. D7rif varied with soil type and temperature but not with the two soil water potentials tested. After 63 days, P.f. D7rif was recovered at levels greater than log 5.5 colony forming units (CFU g−1 soil from five of the nine test soils, a level adequate to suppress downy brome under field or range conditions.

Iron-regulated metabolites of plant growth-promoting Pseudomonas fluorescens WCS374 : Their role in induced systemic resistance

NARCIS (Netherlands)

Djavaheri, M.

2007-01-01

The plant growth-promoting rhizobacterium Pseudomonas fluorescens WCS374r effectively suppresses fusarium wilt in radish by induced systemic resistance (ISR). In radish, WCS374r-mediated ISR depends partly on iron-regulated metabolites. Under iron-limiting conditions, P. fluorescens WCS374r produces

Impact du séchage sur la viabilité de Pseudomonas fluorescens (synthèse bibliographique

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Mputu Kanyinda, JN.

2014-01-01

Full Text Available Impact of drying on Pseudomonas fluorescens viability. A review. Drying Pseudomonas fluorescens makes for more economical storage, transportation and marketing. The aim of the drying process is to stop and to stabilize all biological activity for optimal storage, compatible with the conservation of the maximum desired viability of the microorganisms. However, the viability rate of the bacteria after drying depends on the operating conditions of the drying process. One of the most important criteria to consider during the drying of biologically active products is the quality of the final dried product. Freeze-drying is the drying method most commonly used for Pseudomonas fluorescens. After their production, the bacteria are harvested by centrifugation and are freeze-dried, but the changes in temperature induced by freeze-drying are not without consequence for the cells. The freeze-drying process induces cell damage: peroxidation of fatty acids and proteins and DNA oxidation. However, use of protective compounds during freeze-drying and during storage increases significantly the rate of cell viability.

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

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.

Genomic and Genetic Diversity within the Pseudomonas fluorescens Complex.

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Daniel Garrido-Sanz

Full Text Available The Pseudomonas fluorescens complex includes Pseudomonas strains that have been taxonomically assigned to more than fifty different species, many of which have been described as plant growth-promoting rhizobacteria (PGPR with potential applications in biocontrol and biofertilization. So far the phylogeny of this complex has been analyzed according to phenotypic traits, 16S rDNA, MLSA and inferred by whole-genome analysis. However, since most of the type strains have not been fully sequenced and new species are frequently described, correlation between taxonomy and phylogenomic analysis is missing. In recent years, the genomes of a large number of strains have been sequenced, showing important genomic heterogeneity and providing information suitable for genomic studies that are important to understand the genomic and genetic diversity shown by strains of this complex. Based on MLSA and several whole-genome sequence-based analyses of 93 sequenced strains, we have divided the P. fluorescens complex into eight phylogenomic groups that agree with previous works based on type strains. Digital DDH (dDDH identified 69 species and 75 subspecies within the 93 genomes. The eight groups corresponded to clustering with a threshold of 31.8% dDDH, in full agreement with our MLSA. The Average Nucleotide Identity (ANI approach showed inconsistencies regarding the assignment to species and to the eight groups. The small core genome of 1,334 CDSs and the large pan-genome of 30,848 CDSs, show the large diversity and genetic heterogeneity of the P. fluorescens complex. However, a low number of strains were enough to explain most of the CDSs diversity at core and strain-specific genomic fractions. Finally, the identification and analysis of group-specific genome and the screening for distinctive characters revealed a phylogenomic distribution of traits among the groups that provided insights into biocontrol and bioremediation applications as well as their role as

Interactions of trivalent and tetravalent heavy metal-siderophore complexes with pseudomonas fluorescens

International Nuclear Information System (INIS)

Yoshida, T.; Ozaki, T.; Ohnuki, T.; Francis, A.J.

2004-01-01

We investigated the interactions of the Fe(III)-, Eu(III)-, and Hf(IV)-desferrioxamine B (DFO) complexes with the Gram-negative aerobic bacterium Pseudomonas fluorescens. Potentiometric titration of 1:1 Fe(III)-, Eu(III)-, and Hf(IV)-DFO complexes showed that Hf(IV) formed a strong complex with DFO whose stability was comparable to that of the Fe(III)-DFO complex, while Eu(III) formed a weaker one. DFO in a growth medium was not degraded by P. fluorescens. Contact of P. fluorescens cells with the Fe(III)-, Eu(III)-, and Hf(IV)-DFO complexes at pH 4-9 revealed that there was negligible adsorption of Hf(IV) and Fe(III), whereas Eu(III) was dissociated from DFO and was readily adsorbed by the cells. These results suggest that Fe(III) and Hf(IV) form stable complexes with DFO and are not adsorbed by P. fluorescens cells. Europium(III) forms a weaker complex with DFO than Fe(III) and Hf(IV) do and its DFO complex is readily dissociated in the presence of the cells. (orig.)

Inactivation of Pseudomonas fluorescens in skim milk by combinations of pulsed electric fields and organic acids.

Science.gov (United States)

Fernández-Molina, Juan J; Altunakar, Bilge; Bermúdez-Aguirre, Daniela; Swanson, Barry G; Barbosa-Cánovas, Gustavo V

2005-06-01

Pseudomonas fluorescens suspended in skim milk was inactivated by application of pulsed electric fields (PEF) either alone or in combination with acetic or propionic acid. The initial concentration of microorganisms ranged from 10(5) to 10(6) CFU/ml. Addition of acetic acid and propionic acid to skim milk inactivated 0.24 and 0.48 log CFU/ml P. fluorescens, respectively. Sets of 10, 20, and 30 pulses were applied to the skim milk using exponentially decaying pulses with pulse lengths of 2 micros and pulse frequencies of 3 Hz. Treatment temperature was maintained between 16 and 20 degrees C. In the absence of organic acids, PEF treatment of skim milk at field intensities of 31 and 38 kV/cm reduced P. fluorescens populations by 1.0 to 1.8 and by 1.2 to 1.9 log CFU/ml, respectively. Additions of acetic and propionic acid to the skim milk in a pH range of 5.0 to 5.3 and PEF treatment at 31, 33, and 34 kV/cm, and 36, 37, and 38 kV/cm reduced the population of P. fluorescens by 1.4 and 1.8 log CFU/ml, respectively. No synergistic effect resulted from the combination of PEF with acetic or propionic acid.

Sorption of Eu(III) on Pseudomonas fluorescens in the presence of citric acid

International Nuclear Information System (INIS)

Suzuki, Yoshinori; Tsushima, Satoru; Yamamoto, Ichiro; Nankawa, Takuya; Yoshida, Takahiro; Ozaki, Takuo; Ohnuki, Toshihiko; Francis, Arokiasamy J.; Enokida, Youichi

2005-01-01

We studied the sorption of Eu(III) on Pseudomonas fluorescens in the absence and presence of citric acid by a batch method. The cells were placed in a solution containing 2 μM of Eu(III) and 0, 100, or 1000 μM of citric acid at pH 3 9 for 5 hours. In the absence of citric acid, almost 100% of Eu(III) was sorbed on P. fluorescens at pHs below 7; above 7, sorption decreased with an increase in pH. The time course of Eu(III) sorption on P. fluorescens showed that a fraction of it was desorbed into the solution at alkaline pHs, suggesting that the bacterium may release some exudates. With citric acid present, we found that at higher concentrations there was lower sorption of Eu(III), reflecting the formation of Eu(III)-citrate complexes with the Eu(III)-cell-surface complexes. This decrease in Eu(III) sorption was significant in alkaline pHs. These findings suggest that citric acid which is ubiquitously found in the environment enhances migration of trivalent actinides in the alkaline environment. (author)

Nunamycin and Nunapeptin: Two novel cyclic peptides are key components of the antimicrobial activity of the Greenlandic isolate Pseudomonas fluorescens In5

DEFF Research Database (Denmark)

Hennessy, Rosanna Catherine; Phippen, Christopher; Nielsen, Kristian F.

Pseudomonas spp. are a rich source of secondary metabolites including bioactive non-ribosomal peptides (NRPs) and polyketides. NRPs are synthesised in large assembly lines by multi-domain modular enzymes known as NRP-synthetases (NRPS). Nunamycin and nunapeptin are two cyclic NRPs synthesised...... by the Greenlandic isolate P. fluorescens In5. Nunamycin shows antifungal activity against the basidiomycete Rhizoctonia solani whereas the only partially structure elucidated nunapeptin appears most active against the ascomycete Fusarium graminearum and the oomycete Pythium aphanidermatum. Originally isolated from...

Genome Sequence of the Biocontrol Strain Pseudomonas fluorescens F113

Science.gov (United States)

Redondo-Nieto, Miguel; Barret, Matthieu; Morrisey, John P.; Germaine, Kieran; Martínez-Granero, Francisco; Barahona, Emma; Navazo, Ana; Sánchez-Contreras, María; Moynihan, Jennifer A.; Giddens, Stephen R.; Coppoolse, Eric R.; Muriel, Candela; Stiekema, Willem J.; Rainey, Paul B.; Dowling, David; O'Gara, Fergal; Martín, Marta

2012-01-01

Pseudomonas fluorescens F113 is a plant growth-promoting rhizobacterium (PGPR) that has biocontrol activity against fungal plant pathogens and is a model for rhizosphere colonization. Here, we present its complete genome sequence, which shows that besides a core genome very similar to those of other strains sequenced within this species, F113 possesses a wide array of genes encoding specialized functions for thriving in the rhizosphere and interacting with eukaryotic organisms. PMID:22328765

Pseudomonas fluorescens strain CL145A - a biopesticide for the control of zebra and quagga mussels (Bivalvia: Dreissenidae).

Science.gov (United States)

Molloy, Daniel P; Mayer, Denise A; Gaylo, Michael J; Morse, John T; Presti, Kathleen T; Sawyko, Paul M; Karatayev, Alexander Y; Burlakova, Lyubov E; Laruelle, Franck; Nishikawa, Kimi C; Griffin, Barbara H

2013-05-01

Zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena rostriformis bugensis) are the "poster children" of high-impact aquatic invasive species. In an effort to develop an effective and environmentally acceptable method to control their fouling of raw-water conduits, we have investigated the potential use of bacteria and their natural metabolic products as selective biological control agents. An outcome of this effort was the discovery of Pseudomonas fluorescens strain CL145A - an environmental isolate that kills these dreissenid mussels by intoxication (i.e., not infection). In the present paper, we use molecular methods to reconfirm that CL145A is a strain of the species P. fluorescens, and provide a phylogenetic analysis of the strain in relation to other Pseudomonas spp. We also provide evidence that the natural product lethal to dreissenids is associated with the cell wall of P. fluorescens CL145A, is a heat-labile secondary metabolite, and has degradable toxicity within 24 h when applied to water. CL145A appears to be an unusual strain of P. fluorescens since it was the only one among the ten strains tested to cause high mussel mortality. Pipe trials conducted under once-through conditions indicated: (1) P. fluorescens CL145A cells were efficacious against both zebra and quagga mussels, with high mortalities achieved against both species, and (2) as long as the total quantity of bacterial cells applied during the entire treatment period was the same, similar mussel mortality could be achieved in treatments lasting 1.5-12.0 h, with longer treatment durations achieving lower mortalities. The efficacy data presented herein, in combination with prior demonstration of its low risk of non-target impact, indicate that P. fluorescens CL145A cells have significant promise as an effective and environmentally safe control agent against these invasive mussels. Copyright © 2012 Elsevier Inc. All rights reserved.

Evolutionary history of the phl gene cluster in the plant-associated bacterium Pseudomonas fluorescens

NARCIS (Netherlands)

Moynihan, J.A.; Morrissey, J.P.; Coppoolse, E.; Stiekema, W.J.; O'Gara, F.; Boyd, E.F.

2009-01-01

Pseudomonas fluorescens is of agricultural and economic importance as a biological control agent largely because of its plant-association and production of secondary metabolites, in particular 2, 4-diacetylphloroglucinol (2, 4-DAPG). This polyketide, which is encoded by the eight gene phl cluster,

Boolean models of biosurfactants production in Pseudomonas fluorescens.

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Adrien Richard

Full Text Available Cyclolipopeptides (CLPs are biosurfactants produced by numerous Pseudomonas fluorescens strains. CLP production is known to be regulated at least by the GacA/GacS two-component pathway, but the full regulatory network is yet largely unknown. In the clinical strain MFN1032, CLP production is abolished by a mutation in the phospholipase C gene (plcC and not restored by plcC complementation. Their production is also subject to phenotypic variation. We used a modelling approach with Boolean networks, which takes into account all these observations concerning CLP production without any assumption on the topology of the considered network. Intensive computation yielded numerous models that satisfy these properties. All models minimizing the number of components point to a bistability in CLP production, which requires the presence of a yet unknown key self-inducible regulator. Furthermore, all suggest that a set of yet unexplained phenotypic variants might also be due to this epigenetic switch. The simplest of these Boolean networks was used to propose a biological regulatory network for CLP production. This modelling approach has allowed a possible regulation to be unravelled and an unusual behaviour of CLP production in P. fluorescens to be explained.

Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds

NARCIS (Netherlands)

Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M.; Park, Kyungseok

2015-01-01

Abstract Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens

Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

Energy Technology Data Exchange (ETDEWEB)

Daniel P. Molloy

2004-02-24

The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

Effects of gamma irradiation on the survival of Pseudomonas fluorescens inoculated on romaine lettuce

Science.gov (United States)

Irradiation of fresh fruits and vegetables has been utilized as a post-harvest intervention measure for inactivation of microbial pathogens. Pseudomonas fluorescens 2-79, Q8R1, Q287 are non-plant pathogenic, non-pectolytic strains of a potential biocontrol agent. We tested the sensitivity of these s...

Biosynthesis of the antimicrobial cyclic lipopeptides nunamycin and nunapeptin by Pseudomonas fluorescens strain In5 is regulated by the LuxR‐type transcriptional regulator NunF

OpenAIRE

Hennessy, Rosanna C.; Phippen, Christopher B. W.; Nielsen, Kristian F.; Olsson, Stefan; Stougaard, Peter

2017-01-01

Abstract Nunamycin and nunapeptin are two antimicrobial cyclic lipopeptides (CLPs) produced by Pseudomonas fluorescens In5 and synthesized by nonribosomal synthetases (NRPS) located on two gene clusters designated the nun–nup regulon. Organization of the regulon is similar to clusters found in other CLP‐producing pseudomonads except for the border regions where putative LuxR‐type regulators are located. This study focuses on understanding the regulatory role of the LuxR‐type‐encoding gene nun...

Biosynthesis of the antimicrobial cyclic lipopeptides nunamycin and nunapeptin by Pseudomonas fluorescens strain In5 is regulated by the LuxR-type transcriptional regulator NunF

DEFF Research Database (Denmark)

Hennessy, Rosanna Catherine; Phippen, Christopher; Nielsen, Kristian Fog

2017-01-01

-producing pseudomonads except for the border regions where putative LuxR-type regulators are located. This study focuses on understanding the regulatory role of the LuxR-type-encoding gene nunF in CLP production of P. fluorescens In5. Functional analysis of nunF coupled with liquid chromatography-high-resolution mass......Nunamycin and nunapeptin are two antimicrobial cyclic lipopeptides (CLPs) produced by Pseudomonas fluorescens In5 and synthesized by nonribosomal synthetases (NRPS) located on two gene clusters designated the nun-nup regulon. Organization of the regulon is similar to clusters found in other CLP...... spectrometry (LC-HRMS) showed that CLP biosynthesis is regulated by nunF. Quantitative real-time PCR analysis indicated that transcription of the NRPS genes catalyzing CLP production is strongly reduced when nunF is mutated indicating that nunF is part of the nun-nup regulon. Swarming and biofilm formation...

Crystallization, diffraction data collection and preliminary crystallographic analysis of DING protein from Pseudomonas fluorescens

International Nuclear Information System (INIS)

Moniot, Sebastien; Elias, Mikael; Kim, Donghyo; Scott, Ken; Chabriere, Eric

2007-01-01

Crystallization of DING protein from P. fluorescens is reported. A complete data set was collected to 1.43 Å resolution. PfluDING is a phosphate-binding protein expressed in Pseudomonas fluorescens. This protein is clearly distinct from the bacterial ABC transporter soluble phosphate-binding protein PstS and is more homologous to eukaryotic DING proteins. Interestingly, bacterial DING proteins have only been detected in certain Pseudomonas species. Although DING proteins seem to be ubiquitous in eukaryotes, they are systematically absent from eukaryotic genomic databases and thus are still quite mysterious and poorly characterized. PfluDING displays mitogenic activity towards human cells and binds various ligands such as inorganic phosphate, pyrophosphate, nucleotide triphosphates and cotinine. Here, the crystallization of PfluDING is reported in a monoclinic space group (P2 1 ), with typical unit-cell parameters a = 36.7, b = 123.7, c = 40.8 Å, α = 90, β = 116.7, γ = 90°. Preliminary crystallographic analysis reveals good diffraction quality for these crystals and a 1.43 Å resolution data set has been collected

Water flow induced transport of Pseudomonas fluorescens cells through soil columns as affected by inoculant treatment

NARCIS (Netherlands)

Hekman, W.E.; Heijnen, C.E.; Trevors, J.T.; Elsas, van J.D.

1994-01-01

Water flow induced transport of Pseudomonas fluorescens cells through soil columns was measured as affected by the inoculant treatment. Bacterial cells were introduced into the topsoil of columns, either encapsulated in alginate beads of different types or mixed with bentonite clay in concentrations

Assessment of DAPG-producing Pseudomonas fluorescens for management of Meloidogyne incognita and Fusarium oxysporum on watermelon

Science.gov (United States)

Pseudomonas fluorescens isolates Clinto 1R, Wayne 1R and Wood 1R, which produce the antibiotic 2,4-diacetylphloroglucinol (DAPG), can suppress soilborne diseases and promote plant growth. Consequently, these beneficial bacterial isolates were tested on watermelon plants for suppression of Meloidogy...

No apparent costs for facultative antibiotic production by the soil bacterium Pseudomonas fluorescens Pf0-1.

Science.gov (United States)

Garbeva, Paolina; Tyc, Olaf; Remus-Emsermann, Mitja N P; van der Wal, Annemieke; Vos, Michiel; Silby, Mark; de Boer, Wietse

2011-01-01

Many soil-inhabiting bacteria are known to produce secondary metabolites that can suppress microorganisms competing for the same resources. The production of antimicrobial compounds is expected to incur fitness costs for the producing bacteria. Such costs form the basis for models on the co-existence of antibiotic-producing and non-antibiotic producing strains. However, so far studies quantifying the costs of antibiotic production by bacteria are scarce. The current study reports on possible costs, for antibiotic production by Pseudomonas fluorescens Pf0-1, a soil bacterium that is induced to produce a broad-spectrum antibiotic when it is confronted with non-related bacterial competitors or supernatants of their cultures. We measured the possible cost of antibiotic production for Pseudomonas fluorescens Pf0-1 by monitoring changes in growth rate with and without induction of antibiotic production by supernatant of a bacterial competitor, namely Pedobacter sp.. Experiments were performed in liquid as well as on semi-solid media under nutrient-limited conditions that are expected to most clearly reveal fitness costs. Our results did not reveal any significant costs for production of antibiotics by Pseudomonas fluorescens Pf0-1. Comparison of growth rates of the antibiotic-producing wild-type cells with those of non-antibiotic producing mutants did not reveal costs of antibiotic production either. Based on our findings we propose that the facultative production of antibiotics might not be selected to mitigate metabolic costs, but instead might be advantageous because it limits the risk of competitors evolving resistance, or even the risk of competitors feeding on the compounds produced.

Atmospheric-pressure air microplasma jets in aqueous media for the inactivation of Pseudomonas fluorescens cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xianhui; Yang, Si-ze [Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); Liu, Dongping [Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China); School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Song, Ying [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116023 (China); Sun, Yue [School of Physics, Changchun University of Science and Technology, Changchun 130022 (China)

2013-05-15

The hollow fiber-based cold air microplasma jet array running at atmospheric pressure has been designed to inactivate Pseudomonas fluorescens (P. fluorescens) cells in vitro in aqueous media. The influences of electrode configurations, air flow rate, and applied voltage on the discharge characteristics of the single microplasma jet operating in aqueous media are presented, and the bactericidal efficiency of the hollow fibers-based and large-volume microplasma jet array is reported. Optical emission spectroscopy is utilized to identify excited species during the antibacterial testing of plasma in solutions. These well-aligned and rather stable air microplasma jets containing a variety of short-lived species, such as OH and O radicals and charged particles, are in direct contact with aqueous media and are very effective in killing P. fluorescens cells in aqueous media. This design shows its potential application for atmospheric pressure air plasma inactivation of bacteria cells in aqueous media.

Trichoderma harzianum enhances the production of nematicidal compounds in vitro and improves biocontrol of Meloidogyne javanica by Pseudomonas fluorescens in tomato.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S

2004-01-01

To determine the influence of soil-borne fungus Trichoderma harzianum on the biocontrol performance of Pseudomonas fluorescens strain CHA0 and its 2,4-diacetylphloroglucinol (DAPG) overproducing derivative CHA0/pME3424 against Meloidogyne javanica. Amendment of the culture filtrate (CF) or methanol extract of the CF of a T. harzianum strain Th6 to P. fluorescens growth medium enhanced the production of nematicidal compound(s) by bacterial inoculants in vitro. In addition, bacteria overwhelmingly expressed phl'-'lacZ reporter gene when the medium was amended with CF of T. harzianum. Pseudomonas fluorescens and T. harzianum applied together in unsterilized sandy loam soil caused greater reduction in nematode population densities in tomato roots. Trichoderma harzianum improves root-knot nematode biocontrol by the antagonistic rhizobacterium P. fluorescens both in vitro and under glasshouse conditions. The synergistic effect of T. harzianum on the production of nematicidal compound(s) critical in biocontrol may improve the efficacy of biocontrol bacteria against plant-parasitic nematodes. Considering the inconsistent performance of the biocontrol agents under field conditions, application of a mixture of compatible T. harzianum and P. fluorescens would more closely mimic the natural situation and might broaden the spectrum of biocontrol activity with enhanced efficacy and reliability of control.

Supervivencia de Pseudomonas fluorescens en suelos con diferente contenido de materia orgánica Pseudomonas fluorescens survival in soils with different contents of organic matter

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E.B.R. Perotti

2005-06-01

Full Text Available Pseudomonas fluorescens es una bacteria PGPR (plant growth promoting rhizobacteria, heterótrofa, capaz de combatir fitopatógenos edáficos. Su supervivencia podría estar favorecida por el elevado contenido de materia orgánica del suelo (MOS. Para probarlo, se inocularon, en condiciones de laboratorio, tres cepas de P. fluorescens: UP61, C7R12, y P190 (nativa de Balcarce, Buenos Aires en suelos rizosféricos de tomate representativos de diferentes zonas de Argentina: suelo Argiudol (Balcarce, y Zavalla, Santa Fe y suelo Torrifluvens (Cipolletti, Río Negro (MOS %: 7,2; 4,3 y 2,6 respectivamente. Los resultados indicaron que la supervivencia de P. fluorescens en los suelos Argiudoles fue similar; aunque las pendientes de las curvas de supervivencia en el suelo de Zavalla fueron menores que las observadas en el suelo de Balcarce. La producción de CO2 fue superior en el suelo de Balcarce que en el suelo de Zavalla (4,3 y 2,8 mmol.g-1suelo, esta diferencia podría ser explicada por la existencia de una mayor presión competitiva por parte de la microflora nativa. La supervivencia en el suelo Torrifluvens resultó mínima, lo que sería atribuible a su elevada conductividad eléctrica más que al menor contenido de MOS. La cepa UP61 presentó en todos los casos la mejor supervivencia.Pseudomonas fluorescens are plant growth promoting rhizobacteria (PGPR. The survival of this inoculated heterotrophic bacterium may be affected by soil organic matter content (SOM. To confirm this hypothesis, three strains of P. fluorescens: UP61, C7R12 y P190 (native of Balcarce, Buenos Aires were inoculated, in laboratory conditions, into three argentine rhizospheric soils: two Argiudolls (Balcarce, and Zavalla, Santa Fe and a Torrifluvens (Cipolletti, Río Negro with different SOM: 7,2; 4,3; and 2,6%, respectibily. The results indicated that the all three isolates survival in general was not different. The slopes of the regression curves in Zavalla soil were very

Sensitivity of Pseudomonas fluorescens to gamma irradiation following surface inoculations on romaine lettuce and baby spinach

Science.gov (United States)

Irradiation of fresh fruits and vegetables is a post-harvest intervention measure often used to inactivate pathogenic food-borne microbes. We evaluated the sensitivity of Pseudomonas fluorescens strains (2-79, Q8R1, Q287) to gamma irradiation following surface inoculations on romaine lettuce and spi...

Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens.

Science.gov (United States)

Nayaka, Siddaiah Chandra; Shankar, Arakere C Udaya; Reddy, Munagala S; Niranjana, Siddapura R; Prakash, Harishchandra S; Shetty, Hunthrike S; Mortensen, Carmen N

2009-07-01

Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have elicited considerable attention over the past decade owing to their association with animal disease syndromes. Hence, the present study was conducted to evaluate ecofriendly approaches by using a maize rhizosphere isolate of Pseudomonas fluorescens (Trev.) Mig. and its formulation to control ear rot disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars. The field trials included both seed treatment and foliar spray. For all the experiments, P. fluorescens was formulated using corn starch, wheat bran and talc powder. In each case there were three different treatments of P. fluorescens, a non-treated control and chemical control. Pure culture and the formulations, in comparison with the control, increased plant growth and vigour as measured by seed germination, seedling vigour, plant height, 1000 seed weight and yield. P. fluorescens pure culture used as seed treatment and as spray treatment enhanced the growth parameters and reduced the incidence of F. verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize kernels intended for human and animal feed. (c) 2009 Society of Chemical Industry.

Exposure-related effects of formulated Pseudomonas fluorescens strain CL145A to glochidia from seven unionid mussel species

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Severson, Todd J.; Schreier, Theresa M.; Mayer, Denise A.; Aloisi, Douglas B.; Eckert, Nathan L.

2015-01-01

The study was completed to evaluate the exposure-related effects of a biopesticide for dreissenid mussel (Dreissena polymorpha, zebra mussel and Dreissena rostriformis bugensis, quagga mussel) control on glochidia from unionid mussels endemic to the Great Lakes and Upper Mississippi River Basins. The commercially prepared biopesticide was either a spray-dried powder (SDP) or freeze-dried powder (FDP) formulation of Pseudomonas fluorescens, strain CL145A. Glochidia of the unionid mussel species Lampsilis cardium, Lampsilis siliquoidea,Lampsilis higginsii, Ligumia recta, Obovaria olivaria, and Actinonaias ligamentina were exposed to SDP-formulated P. fluorescens andLampsilis cardium and Megalonaias nervosa were exposed to FDP-formulated P. fluorescens.

Genetic Control of Plant Root Colonization by the Biocontrol agent, Pseudomonas fluorescens

Energy Technology Data Exchange (ETDEWEB)

Cole, Benjamin J.; Fletcher, Meghan; Waters, Jordan; Wetmore, Kelly; Blow, Matthew J.; Deutschbauer, Adam M.; Dangl, Jeffry L.; Visel, Axel

2015-03-19

Plant growth promoting rhizobacteria (PGPR) are a critical component of plant root ecosystems. PGPR promote plant growth by solubilizing inaccessible minerals, suppressing pathogenic microorganisms in the soil, and directly stimulating growth through hormone synthesis. Pseudomonas fluorescens is a well-established PGPR isolated from wheat roots that can also colonize the root system of the model plant, Arabidopsis thaliana. We have created barcoded transposon insertion mutant libraries suitable for genome-wide transposon-mediated mutagenesis followed by sequencing (TnSeq). These libraries consist of over 105 independent insertions, collectively providing loss-of-function mutants for nearly all genes in the P.fluorescens genome. Each insertion mutant can be unambiguously identified by a randomized 20 nucleotide sequence (barcode) engineered into the transposon sequence. We used these libraries in a gnotobiotic assay to examine the colonization ability of P.fluorescens on A.thaliana roots. Taking advantage of the ability to distinguish individual colonization events using barcode sequences, we assessed the timing and microbial concentration dependence of colonization of the rhizoplane niche. These data provide direct insight into the dynamics of plant root colonization in an in vivo system and define baseline parameters for the systematic identification of the bacterial genes and molecular pathways using TnSeq assays. Having determined parameters that facilitate potential colonization of roots by thousands of independent insertion mutants in a single assay, we are currently establishing a genome-wide functional map of genes required for root colonization in P.fluorescens. Importantly, the approach developed and optimized here for P.fluorescens>A.thaliana colonization will be applicable to a wide range of plant-microbe interactions, including biofuel feedstock plants and microbes known or hypothesized to impact on biofuel-relevant traits including biomass productivity

Characterization of toxin complex gene clusters and insect toxicity of bacteria representing four subgroups of Pseudomonas fluorescens

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Ten strains representing four lineages of Pseudomonas (P. chlororaphis, P. corrugata, P. koreensis, and P. fluorescens subgroups) were evaluated for toxicity to the tobacco hornworm Manduca sexta and the fruit fly Drosophila melanogaster. The three strains within the P. chlororaphis subgroup exhibi...

No apparent costs for facultative antibiotic production by the soil bacterium Pseudomonas fluorescens Pf0-1.

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Paolina Garbeva

Full Text Available BACKGROUND: Many soil-inhabiting bacteria are known to produce secondary metabolites that can suppress microorganisms competing for the same resources. The production of antimicrobial compounds is expected to incur fitness costs for the producing bacteria. Such costs form the basis for models on the co-existence of antibiotic-producing and non-antibiotic producing strains. However, so far studies quantifying the costs of antibiotic production by bacteria are scarce. The current study reports on possible costs, for antibiotic production by Pseudomonas fluorescens Pf0-1, a soil bacterium that is induced to produce a broad-spectrum antibiotic when it is confronted with non-related bacterial competitors or supernatants of their cultures. METHODOLOGY AND PRINCIPAL FINDINGS: We measured the possible cost of antibiotic production for Pseudomonas fluorescens Pf0-1 by monitoring changes in growth rate with and without induction of antibiotic production by supernatant of a bacterial competitor, namely Pedobacter sp.. Experiments were performed in liquid as well as on semi-solid media under nutrient-limited conditions that are expected to most clearly reveal fitness costs. Our results did not reveal any significant costs for production of antibiotics by Pseudomonas fluorescens Pf0-1. Comparison of growth rates of the antibiotic-producing wild-type cells with those of non-antibiotic producing mutants did not reveal costs of antibiotic production either. SIGNIFICANCE: Based on our findings we propose that the facultative production of antibiotics might not be selected to mitigate metabolic costs, but instead might be advantageous because it limits the risk of competitors evolving resistance, or even the risk of competitors feeding on the compounds produced.

Characterization of the biocontrol activity of pseudomonas fluorescens strain X reveals novel genes regulated by glucose.

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Gerasimos F Kremmydas

Full Text Available Pseudomonas fluorescens strain X, a bacterial isolate from the rhizosphere of bean seedlings, has the ability to suppress damping-off caused by the oomycete Pythium ultimum. To determine the genes controlling the biocontrol activity of strain X, transposon mutagenesis, sequencing and complementation was performed. Results indicate that, biocontrol ability of this isolate is attributed to gcd gene encoding glucose dehydrogenase, genes encoding its co-enzyme pyrroloquinoline quinone (PQQ, and two genes (sup5 and sup6 which seem to be organized in a putative operon. This operon (named supX consists of five genes, one of which encodes a non-ribosomal peptide synthase. A unique binding site for a GntR-type transcriptional factor is localized upstream of the supX putative operon. Synteny comparison of the genes in supX revealed that they are common in the genus Pseudomonas, but with a low degree of similarity. supX shows high similarity only to the mangotoxin operon of Ps. syringae pv. syringae UMAF0158. Quantitative real-time PCR analysis indicated that transcription of supX is strongly reduced in the gcd and PQQ-minus mutants of Ps. fluorescens strain X. On the contrary, transcription of supX in the wild type is enhanced by glucose and transcription levels that appear to be higher during the stationary phase. Gcd, which uses PQQ as a cofactor, catalyses the oxidation of glucose to gluconic acid, which controls the activity of the GntR family of transcriptional factors. The genes in the supX putative operon have not been implicated before in the biocontrol of plant pathogens by pseudomonads. They are involved in the biosynthesis of an antimicrobial compound by Ps. fluorescens strain X and their transcription is controlled by glucose, possibly through the activity of a GntR-type transcriptional factor binding upstream of this putative operon.

Effect of Naphthalene and Salicylate Analogues on the Bioluminescence of Bioreporter Pseudomonas Fluorescens HK44.

Czech Academy of Sciences Publication Activity Database

Trögl, Josef; Kuncová, Gabriela; Kubicová, L.; Pařík, P.; Hálová, Jaroslava; Demnerová, K.; Ripp, S.; Sayler, G. S.

2007-01-01

Roč. 52, 1 (2007) , s. 3-14 ISSN 0015-5632 R&D Projects: GA ČR(CZ) GA104/05/2637; GA ČR(CZ) GA203/06/1244 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40320502 Keywords : pseudomonas fluorescens HK44 * bioluminescence * bioluminescence Subject RIV: CE - Biochemistry Impact factor: 0.989, year: 2007

Getting the ecology into interactions between plants and the plant growth-promoting bacterium Pseudomonas fluorescens.

Science.gov (United States)

Hol, W H Gera; Bezemer, T Martijn; Biere, Arjen

2013-01-01

Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas fluorescens) on plants through induced plant defense. This model organism has provided much understanding of the underlying molecular mechanisms of PGPR-induced plant defense. However, this knowledge can only be appreciated at full value once we know to what extent these mechanisms also occur under more realistic, species-diverse conditions as are occurring in the plant rhizosphere. To provide the necessary ecological context, we review the literature to compare the effect of P. fluorescens on induced plant defense when it is present as a single species or in combination with other soil dwelling species. Specifically, we discuss combinations with other plant mutualists (bacterial or fungal), plant pathogens (bacterial or fungal), bacterivores (nematode or protozoa), and decomposers. Synergistic interactions between P. fluorescens and other plant mutualists are much more commonly reported than antagonistic interactions. Recent developments have enabled screenings of P. fluorescens genomes for defense traits and this could help with selection of strains with likely positive interactions on biocontrol. However, studies that examine the effects of multiple herbivores, pathogens, or herbivores and pathogens together on the effectiveness of PGPR to induce plant defenses are underrepresented and we are not aware of any study that has examined interactions between P. fluorescens and bacterivores or decomposers. As co-occurring soil organisms can enhance but also reduce the effectiveness of PGPR, a better understanding of the biotic factors modulating P. fluorescens-plant interactions will improve the effectiveness of introducing P. fluorescens to enhance plant production and defense.

Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling.

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Kandasamy, Saveetha; Loganathan, Karthiba; Muthuraj, Raveendran; Duraisamy, Saravanakumar; Seetharaman, Suresh; Thiruvengadam, Raguchander; Ponnusamy, Balasubramanian; Ramasamy, Samiyappan

2009-12-24

Plant Growth Promoting Rhizobacteria (PGPR), Pseudomonas fluorescens strain KH-1 was found to exhibit plant growth promotional activity in rice under both in-vitro and in-vivo conditions. But the mechanism underlying such promotional activity of P. fluorescens is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to P. fluorescens treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry. Priming of P. fluorescens, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein. Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.

Disruption of transporters affiliated with enantio-pyochelin biosynthesis gene cluster of Pseudomonas protegens Pf-5 has pleiotropic effects

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Pseudomonas protegens Pf-5 (formerly Pseudomonas fluorescens) is a biocontrol bacterium that produces the siderophore enantio-pyochelin under conditions of iron starvation in a process that is often accompanied by the secretion of its biosynthesis intermediates, salicylic acid and dihydroaeruginoic ...

Novel ambler class A carbapenem-hydrolyzing beta-lactamase from a Pseudomonas fluorescens isolate from the Seine River, Paris, France.

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Girlich, Delphine; Poirel, Laurent; Nordmann, Patrice

2010-01-01

A Pseudomonas fluorescens isolate (PF-1) resistant to carbapenems was recovered during an environmental survey performed with water from the Seine River (Paris). It expressed a novel Ambler class A carbapenemase, BIC-1, sharing 68 and 59% amino acid identities with beta-lactamases SFC-1 from Serratia fonticola and the plasmid-encoded KPC-2, respectively. beta-Lactamase BIC-1 hydrolyzed penicillins, carbapenems, and cephalosporins except ceftazidime and monobactams. The bla(BIC-1) gene was chromosomally located and was also identified in two other P. fluorescens strains isolated from the Seine River 3 months later.

Adaptive synonymous mutations in an experimentally evolved Pseudomonas fluorescens population

DEFF Research Database (Denmark)

Bailey, Susan; Hinz, Aaron; Kassen, Rees

2014-01-01

Conventional wisdom holds that synonymous mutations, nucleotide changes that do not alter the encoded amino acid, have no detectable effect on phenotype or fitness. However, a growing body of evidence from both comparative and experimental studies suggests otherwise. Synonymous mutations have been...... shown to impact gene expression, protein folding and fitness, however, direct evidence that they can be positively selected, and so contribute to adaptation, is lacking. Here we report the recovery of two beneficial synonymous single base pair changes that arose spontaneously and independently...... in an experimentally evolved population of Pseudomonas fluorescens. We show experimentally that these mutations increase fitness by an amount comparable to non-synonymous mutations and that the fitness increases stem from increased gene expression. These results provide unequivocal evidence that synonymous mutations...

Understanding the molecular basis of plant growth promotional effect of Pseudomonas fluorescens on rice through protein profiling

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Thiruvengadam Raguchander

2009-12-01

Full Text Available Abstract Background Plant Growth Promoting Rhizobacteria (PGPR, Pseudomonas fluorescens strain KH-1 was found to exhibit plant growth promotional activity in rice under both in-vitro and in-vivo conditions. But the mechanism underlying such promotional activity of P. fluorescens is not yet understood clearly. In this study, efforts were made to elucidate the molecular responses of rice plants to P. fluorescens treatment through protein profiling. Two-dimensional polyacrylamide gel electrophoresis strategy was adopted to identify the PGPR responsive proteins and the differentially expressed proteins were analyzed by mass spectrometry. Results Priming of P. fluorescens, 23 different proteins found to be differentially expressed in rice leaf sheaths and MS analysis revealed the differential expression of some important proteins namely putative p23 co-chaperone, Thioredoxin h- rice, Ribulose-bisphosphate carboxylase large chain precursor, Nucleotide diPhosphate kinase, Proteosome sub unit protein and putative glutathione S-transferase protein. Conclusion Functional analyses of the differential proteins were reported to be directly or indirectly involved in growth promotion in plants. Thus, this study confirms the primary role of PGPR strain KH-1 in rice plant growth promotion.

Metabolic functions of Pseudomonas fluorescens strains from Populus deltoides depend on rhizosphere or endosphere isolation compartment

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Collin M Timm

2015-10-01

Full Text Available The bacterial microbiota of plants is diverse, with 1,000s of operational taxonomic units (OTUs associated with any individual plant. In this work we investigate the differences between 19 sequenced Pseudomonas fluorescens strains, isolated from Populus deltoides rhizosphere and endosphere and which represent a single OTU, using phenotypic analysis, comparative genomics, and metabolic models. While no traits were exclusive to either endosphere or rhizosphere P. fluorescens isolates, multiple pathways relevant for plant-bacterial interactions are enriched in endosphere isolate genomes. Further, growth phenotypes such as phosphate solubilization, protease activity, denitrification and root growth promotion are biased towards endosphere isolates. Endosphere isolates have significantly more metabolic pathways for plant signaling compounds and an increased metabolic range that includes utilization of energy rich nucleotides and sugars, consistent with endosphere colonization. Rhizosphere P. fluorescens have fewer pathways representative of plant-bacterial interactions but show metabolic bias towards chemical substrates often found in root exudates. This work reveals the diverse functions that may contribute to colonization of the endosphere by bacteria and are enriched among closely related isolates.

Evaluación de la biorremediación en suelos contaminados con hidrocarburos utilizando pseudomonas fluorescens.

OpenAIRE

Pérez Pozo, Marco Rafael

2018-01-01

Since the discovery of hydrocarbons, their use in industries has caused severe environmental impacts, which have been occurring frequently in various parts of the Ecuadorian Amazon. In the present investigation the biodegradation capacity of Pseudomonas fluorescens was assessed by bioaumentation in soils of the Ecuadorian Amazon contaminated with PAHs (Polycyclic Aromatic Hydrocarbons) and TPHs (Total Petroleum Hydrocarbons). The bioaumentation, is an efficient alternative for this type of...

LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

International Nuclear Information System (INIS)

Molloy, Daniel P.

2001-01-01

These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present

LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA

Energy Technology Data Exchange (ETDEWEB)

Daniel P. Molloy

2001-10-28

These experiments indicated that bacterial strain CL0145A of Pseudomonas fluorescens is equally lethal to the 2 zebra mussel species present in North America, Dreissena polymorpha and Dreissena bugensis. Thus, this bacterial strain should be equally effective at killing zebra mussels in power plant pipes, irrespective of which species is present.

The role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators.

Science.gov (United States)

Couillerot, Olivier; Combes-Meynet, Emeline; Pothier, Joël F; Bellvert, Floriant; Challita, Elita; Poirier, Marie-Andrée; Rohr, René; Comte, Gilles; Moënne-Loccoz, Yvan; Prigent-Combaret, Claire

2011-06-01

Pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (Phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. Here, the effects of synthetic Phl and Phl(+) Pseudomonas fluorescens F113 on Azospirillum brasilense phytostimulators were investigated. Most A. brasilense strains were moderately sensitive to Phl. In vitro, Phl induced accumulation of carotenoids and poly-β-hydroxybutyrate-like granules, cytoplasmic membrane damage and growth inhibition in A. brasilense Cd. Experiments with P. fluorescens F113 and a Phl(-) mutant indicated that Phl production ability contributed to in vitro growth inhibition of A. brasilense Cd and Sp245. Under gnotobiotic conditions, each of the three strains, P. fluorescens F113 and A. brasilense Cd and Sp245, stimulated wheat growth. Co-inoculation of A. brasilense Sp245 and Pseudomonas resulted in the same level of phytostimulation as in single inoculations, whereas it abolished phytostimulation when A. brasilense Cd was used. Pseudomonas Phl production ability resulted in lower Azospirillum cell numbers per root system (based on colony counts) and restricted microscale root colonization of neighbouring Azospirillum cells (based on confocal microscopy), regardless of the A. brasilense strain used. Therefore, this work establishes that Phl(+) pseudomonads have the potential to interfere with A. brasilense phytostimulators on roots and with their plant growth promotion capacity.

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

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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.

Whole-genome sequence of Pseudomonas fluorescens EK007-RG4, a promising biocontrol agent against a broad range of bacteria, including the fire blight bacterium Erwinia amylovora

DEFF Research Database (Denmark)

Habibi, Roghayeh; Tarighi, Saeed; Behravan, Javad

2017-01-01

Here, we report the first draft whole-genome sequence of Pseudomonas fluorescens strain EK007-RG4, which was isolated from the phylloplane of a pear tree. P. fluorescens EK007-RG4 displays strong antagonism against Erwinia amylovora, the causal agent for fire blight disease, in addition to several...

Metabolic engineering of Pseudomonas fluorescens for the production of vanillin from ferulic acid.

Science.gov (United States)

Di Gioia, Diana; Luziatelli, Francesca; Negroni, Andrea; Ficca, Anna Grazia; Fava, Fabio; Ruzzi, Maurizio

2011-12-20

Vanillin is one of the most important flavors in the food industry and there is great interest in its production through biotechnological processes starting from natural substrates such as ferulic acid. Among bacteria, recombinant Escherichia coli strains are the most efficient vanillin producers, whereas Pseudomonas spp. strains, although possessing a broader metabolic versatility, rapidly metabolize various phenolic compounds including vanillin. In order to develop a robust Pseudomonas strain that can produce vanillin in high yields and at high productivity, the vanillin dehydrogenase (vdh)-encoding gene of Pseudomonas fluorescens BF13 strain was inactivated via targeted mutagenesis. The results demonstrated that engineered derivatives of strain BF13 accumulate vanillin if inactivation of vdh is associated with concurrent expression of structural genes for feruloyl-CoA synthetase (fcs) and hydratase/aldolase (ech) from a low-copy plasmid. The conversion of ferulic acid to vanillin was enhanced by optimization of growth conditions, growth phase and parameters of the bioconversion process. The developed strain produced up to 8.41 mM vanillin, which is the highest final titer of vanillin produced by a Pseudomonas strain to date and opens new perspectives in the use of bacterial biocatalysts for biotechnological production of vanillin from agro-industrial wastes which contain ferulic acid. Copyright © 2011 Elsevier B.V. All rights reserved.

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.

Chromosomal insertion of the entire Escherichia coli lactose operon, into two strains of Pseudomonas, using a modified mini-Tn5 delivery system

DEFF Research Database (Denmark)

Hansen, L. H.; Sørensen, S. J.; Jensen, Lars Bogø

1997-01-01

A 12-kb PstI fragment including the entire E. coli lactose operon (lacIPOZYA) was inserted in one copy into the chromosome of Pseudomonas putida, Pseudomonas fluorescens and an E. coli strain with lac(-) phenotype. This was made possible by improvements of an already existing mini-Tn5 transposon...... flanked by NotI sites needed in the mini-Tn5 delivery system; (b) the generation of E. coli nonlysogenic strains expressing the pi protein thus being capable of maintaining and delivering R6K-based mini-Tn5 vectors to other E. coli strains; (c) the successful insertion of the E. coli lactose operon...... into the P. fluorescens chromosome giving P. fluorescens the ability to grow on lactose; (d) evidence from Southern blotting that contradicts the assumption that the mini-Tn5 delivery system always creates one-copy inserts. These improvements allow insertion of large DNA fragments encoding highly expressed...

The effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on model bacterial strains and isolates from industrial wastewater.

Science.gov (United States)

Vasileva-Tonkova, Evgenia; Sotirova, Anna; Galabova, Danka

2011-02-01

In this study, the effect of rhamnolipid biosurfactant produced by Pseudomonas fluorescens on bacterial strains, laboratory strains, and isolates from industrial wastewater was investigated. It was shown that biosurfactant, depending on the concentration, has a neutral or detrimental effect on the growth and protein release of model Gram (+) strain Bacillus subtilis 168. The growth and protein release of model Gram (-) strain Pseudomonas aeruginosa 1390 was not influenced by the presence of biosurfactant in the medium. Rhamnolipid biosurfactant at the used concentrations supported the growth of some slow growing on hexadecane bacterial isolates, members of the microbial community. Changes in cell surface hydrophobicity and permeability of some Gram (+) and Gram (-) isolates in the presence of rhamnolipid biosurfactant were followed in experiments in vitro. It was found that bacterial cells treated with biosurfactant became more or less hydrophobic than untreated cells depending on individual characteristics and abilities of the strains. For all treated strains, an increase in the amount of released protein was observed with increasing the amount of biosurfactant, probably due to increased cell permeability as a result of changes in the organization of cell surface structures. The results obtained could contribute to clarify the relationships between members of the microbial community as well as suggest the efficiency of surface properties of rhamnolipid biosurfactant from Pseudomonas fluorescens making it potentially applicable in bioremediation of hydrocarbon-polluted environments.

Sequencing and Analysis of the Pseudomonas fluorescens GcM5-1A Genome: A Pathogen Living in the Surface Coat of Bursaphelenchus xylophilus.

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Kai Feng

Full Text Available It is known that several bacteria are adherent to the surface coat of pine wood nematode (Bursaphelenchus xylophilus, but their function and role in the pathogenesis of pine wilt disease remains debatable. The Pseudomonas fluorescens GcM5-1A is a bacterium isolated from the surface coat of pine wood nematodes. In previous studies, GcM5-1A was evident in connection with the pathogenicity of pine wilt disease. In this study, we report the de novo sequencing of the GcM5-1A genome. A 600-Mb collection of high-quality reads was obtained and assembled into sequence contigs spanning a 6.01-Mb length. Sequence annotation predicted 5,413 open reading frames, of which 2,988 were homologous to genes in the other four sequenced P. fluorescens isolates (SBW25, WH6, Pf0-1 and Pf-5 and 1,137 were unique to GcM5-1A. Phylogenetic studies and genome comparison revealed that GcM5-1A is more closely related to SBW25 and WH6 isolates than to Pf0-1 and Pf-5 isolates. Towards study of pathogenesis, we identified 79 candidate virulence factors in the genome of GcM5-1A, including the Alg, Fl, Waa gene families, and genes coding the major pathogenic protein fliC. In addition, genes for a complete T3SS system were identified in the genome of GcM5-1A. Such systems have proved to play a critical role in subverting and colonizing the host organisms of many gram-negative pathogenic bacteria. Although the functions of the candidate virulence factors need yet to be deciphered experimentally, the availability of this genome provides a basic platform to obtain informative clues to be addressed in future studies by the pine wilt disease research community.

Characterization of the SPI-1 and Rsp type three secretion systems in Pseudomonas fluorescens F113.

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Barret, Matthieu; Egan, Frank; Moynihan, Jennifer; Morrissey, John P; Lesouhaitier, Olivier; O'Gara, Fergal

2013-06-01

Pseudomonas fluorescens F113 is a plant growth-promoting rhizobacterium (PGPR) isolated from the sugar beet rhizosphere. The recent annotation of the F113 genome sequence has revealed that this strain encodes a wide array of secretion systems, including two complete type three secretion systems (T3SSs) belonging to the Hrp1 and SPI-1 families. While Hrp1 T3SSs are frequently encoded in other P. fluorescens strains, the presence of a SPI-1 T3SS in a plant-beneficial bacterial strain was unexpected. In this work, the genetic organization and expression of these two T3SS loci have been analysed by a combination of transcriptional reporter fusions and transcriptome analyses. Overexpression of two transcriptional activators has shown a number of genes encoding putative T3 effectors. In addition, the influence of these two T3SSs during the interaction of P. fluorescens F113 with some bacterial predators was also assessed. Our data revealed that the transcriptional activator hilA is induced by amoeba and that the SPI-1 T3SS could potentially be involved in resistance to amoeboid grazing. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

Production and properties of biosurfactants from a newly isolated Pseudomonas fluorescens HW-6 growing on hexandecane

Energy Technology Data Exchange (ETDEWEB)

Vasileva-Tonkova, E.; Galabova, D. [Bulgarian Academy of Sciences, Dept. of Microbial Biochemistry, Sofia (Bulgaria); Stoimenova, E.; Lalchev, Z. [Dept. of Biochemistry, Sofia Univ. ' ' St. Kliment Ohridski' ' , Sofia (Bulgaria)

2006-07-15

The newly isolated from industrial wastewater Pseudomonas fluorescens strain HW-6 produced glycolipid biosurfactants at high concentrations (1.4-2.0 g 1{sup -1}) when grown on hexadecane as a sole carbon source. Biosurfactants decreased the surface tension of the air/water interface by 35 mN m{sup -1} and possessed a low critical micelle concentration value of 20 mg 1{sup -1}, which indicated high surface activity. They efficiently emulsified aromatic hydrocarbons, kerosene, n-paraffins and mineral oils. Biosurfactant production contributed to a significant increase in cell hydrophobicity correlated with an increased growth of the strain on hexadecane. The results suggested that the newly isolated strain of Ps. fluorescens and produced glycolipid biosurfactants with effective surface and emulsifying properties are very promising and could find application for bioremediation of hydrocarbon-polluted sites. (orig.)

Type III secretion system and virulence markers highlight similarities and differences between human- and plant-associated pseudomonads related to Pseudomonas fluorescens and P. putida.

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Mazurier, Sylvie; Merieau, Annabelle; Bergeau, Dorian; Decoin, Victorien; Sperandio, Daniel; Crépin, Alexandre; Barbey, Corinne; Jeannot, Katy; Vicré-Gibouin, Maïté; Plésiat, Patrick; Lemanceau, Philippe; Latour, Xavier

2015-04-01

Pseudomonas fluorescens is commonly considered a saprophytic rhizobacterium devoid of pathogenic potential. Nevertheless, the recurrent isolation of strains from clinical human cases could indicate the emergence of novel strains originating from the rhizosphere reservoir, which could be particularly resistant to the immune system and clinical treatment. The importance of type three secretion systems (T3SSs) in the related Pseudomonas aeruginosa nosocomial species and the occurrence of this secretion system in plant-associated P. fluorescens raise the question of whether clinical isolates may also harbor T3SSs. In this study, isolates associated with clinical infections and identified in hospitals as belonging to P. fluorescens were compared with fluorescent pseudomonads harboring T3SSs isolated from plants. Bacterial isolates were tested for (i) their genetic relationships based on their 16S rRNA phylogeny, (ii) the presence of T3SS genes by PCR, and (iii) their infectious potential on animals and plants under environmental or physiological temperature conditions. Two groups of bacteria were delineated among the clinical isolates. The first group encompassed thermotolerant (41°C) isolates from patients suffering from blood infections; these isolates were finally found to not belong to P. fluorescens but were closely related and harbored highly conserved T3SS genes belonging to the Ysc-T3SS family, like the T3SSs from P. aeruginosa. The second group encompassed isolates from patients suffering from cystic fibrosis; these isolates belonged to P. fluorescens and harbored T3SS genes belonging to the Hrp1-T3SS family found commonly in plant-associated P. fluorescens. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Antimicrobial activity of four essential oils against pigmenting Pseudomonas fluorescens and biofilmproducing Staphylococcus aureus of dairy origin

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Francesca Pedonese

2017-12-01

Full Text Available Essential oils (EOs are mixtures of secondary metabolites of plant origin with many useful properties, among which the antimicrobial activity is also of interest for the food industry. EOs can exert their antimicrobial potential both directly, in food products and active packaging, and indirectly, as sanitizing and anti-biofilm agents of food facility surfaces. Aim of this research was to evaluate the antimicrobial activity of four EOs (bergamot, cinnamon, manuka and thyme against Pseudomonas fluorescens and Staphylococcus aureus isolated from milk and dairy products. The chemical composition of EOs was evaluated by Gas Chromatography-Mass Spectrometry analysis. Minimum Inhibitory Concentration values were determined by a microplate method against 9 Ps. fluorescens from marketed mozzarella with blue discoloration defect, and 3 biofilm-producing S. aureus from milk. Reference ATCC strains were included. Pigment production activity by Ps. fluorescens was assessed both in culture and in cheese. EOs of manuka (leptospermone 23% and thyme (carvacrol 30%, pcymene 20%, thymol 15% showed the highest antimicrobial activity against S. aureus, MIC values were 0.012%-0.024% and 0.024% v/v, respectively; meanwhile EOs from thyme and cinnamon (cinnamaldehyde 55% exhibited the best activity against Ps. fluorescens with MIC values of 0.098%-0.195% and 0.195%-0.391% v/v, respectively. The antimicrobial activity of these EOs is promising and they could be exploited in the dairy production chain.

Heat Production by the Denitrifying Bacterium Pseudomonas fluorescens and the Dissimilatory Ammonium-Producing Bacterium Pseudomonas putrefaciens during Anaerobic Growth with Nitrate as the Electron Acceptor

OpenAIRE

Samuelsson, M.-O.; Cadez, P.; Gustafsson, L.

1988-01-01

The heat production rate and the simultaneous nitrate consumption and production and consumption of nitrite and nitrous oxide were monitored during the anaerobic growth of two types of dissimilatory nitrate reducers. Pseudomonas fluorescens, a denitrifier, consumed nitrate and accumulated small amounts of nitrite or nitrous oxide. The heat production rate increased steadily during the course of nitrate consumption and decreased rapidly concomitant with the depletion of the electron acceptors....

The Influence of Pseudomonas fluorescens on Corrosion Products of Archaeological Tin-Bronze Analogues

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Ghiara, G.; Grande, C.; Ferrando, S.; Piccardo, P.

2018-01-01

In this study, tin-bronze analogues of archaeological objects were investigated in the presence of an aerobic Pseudomonas fluorescens strain in a solution, containing chlorides, sulfates, carbonates and nitrates according to a previous archaeological characterization. Classical fixation protocols were employed in order to verify the attachment capacity of such bacteria. In addition, classical metallurgical analytical techniques were used to detect the effect of bacteria on the formation of uncommon corrosion products in such an environment. Results indicate quite a good attachment capacity of the bacteria to the metallic surface and the formation of the uncommon corrosion products sulfates and sulfides is probably connected to the bacterial metabolism.

Bioreporter pseudomonas fluorescens HK44 immobilized in a silica matrix

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Trogl J.

2003-01-01

Full Text Available The bioluminescent bioreporter Pseudomonas fluorescens HK44, the whole cell bacterial biosensor that responds to naphthalene and its metabolites via the production of visible light, was immobilized into a silica matrix by the sol-gel technique. The bioluminescence intensities were measured in the maximum of the bioluminescence band at X = 500 nm. The immobilized cells (>105 cells per g silica matrix produced light after induction by salicylate (cone. > 10 g/l, naphthalene and aminobenzoic acid. The bioluminescence intensities induced by 2,3-dihydroxynaphthalene 3-hydroxybenzoic acid and 4-hydroxybenzoic acid were comparable to a negative control. The cells in the silica layers on glass slides produced light in response to the presence of an inductor at least 8 months after immobilization, and >50 induction cycles. The results showed that these test slides could be used as assays for the multiple determination of water pollution.

Exposure-related effects of Pseudomonas fluorescens (Pf-CL145A) on juvenile unionid mussels

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Weber, Kerry L.; Luoma, James A.; Mayer, Denise A.; Aloisi, Douglas B.; Eckert, Nathan L.

2015-01-01

The exposure-related effects of a commercially prepared spray-dried powder (SDP) or freeze-dried powder (FDP) formulation of Pseudomonas fluorescens (strain CL145A) on the survival of seven species of newly metamorphosed (<72 hours old) freshwater unionid mussels was evaluated. Forty unionid mussels of each species were randomly distributed to test chambers and each species independently exposed for 24 hours to a static dose of either SDP (four species: Lampsilis cardium, Lampsilis siliquoidea, Lampsilis higginsii, andLigumia recta) or FDP (three species: Obovaria olivaria, Actinonaias ligamentina, andMegalonaias nervosa).

Modeling high-intensity pulsed electric field inactivation of a lipase from Pseudomonas fluorescens.

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Soliva-Fortuny, R; Bendicho-Porta, S; Martín-Belloso, O

2006-11-01

The inactivation kinetics of a lipase from Pseudomonas fluorescens (EC 3.1.1.3.) were studied in a simulated skim milk ultrafiltrate treated with high-intensity pulsed electric fields. Samples were subjected to electric field intensities ranging from 16.4 to 27.4 kV/cm for up to 314.5 micros, thus achieving a maximum inactivation of 62.1%. The suitability of describing experimental data using mechanistic first-order kinetics and an empirical model based on the Weibull distribution function is discussed. In addition, different mathematical expressions relating the residual activity values to field strength and treatment time are supplied. A first-order fractional conversion model predicted residual activity with good accuracy (A(f) = 1.018). A mechanistic insight of the model kinetics was that experimental values were the consequence of different structural organizations of the enzyme, with uneven resistance to the pulsed electric field treatments. The Weibull model was also useful in predicting the energy density necessary to achieve lipase inactivation.

Expression, Purification, Crystallization and Preliminary X-ray Analysis of Pseudomonas fluorescens AlgK

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Keiski,C.; Yip, P.; Robinson, H.; Burrows, L.; Howell, P.

2007-01-01

AlgK is an outer-membrane lipoprotein involved in the biosynthesis of alginate in Pseudomonads and Azotobacter vinelandii. A recombinant form of Pseudomonas fluorescens AlgK with a C-terminal polyhistidine affinity tag has been expressed and purified from the periplasm of Escherichia coli cells and diffraction-quality crystals of AlgK have been grown using the hanging-drop vapour-diffusion method. The crystals grow as flat plates with unit-cell parameters a = 79.09, b = 107.85, c = 119.15 {angstrom}, = 96.97{sup o}. The crystals exhibit the symmetry of space group P2{sub 1} and diffract to a minimum d-spacing of 2.5 {angstrom} at Station X29 of the National Synchrotron Light Source, Brookhaven National Laboratory. On the basis of the Matthews coefficient (V{sub M} = 2.53 {angstrom}{sup 3} Da{sup -1}), four protein molecules are estimated to be present in the asymmetric unit.

Pseudomonas fluorescens HK44: Lessons Learned from a Model Whole-Cell Bioreporter with a Broad Application History

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Gary S. Sayler

2012-02-01

Full Text Available Initially described in 1990, Pseudomonas fluorescens HK44 served as the first whole-cell bioreporter genetically endowed with a bioluminescent (luxCDABE phenotype directly linked to a catabolic (naphthalene degradative pathway. HK44 was the first genetically engineered microorganism to be released in the field to monitor bioremediation potential. Subsequent to that release, strain HK44 had been introduced into other solids (soils, sands, liquid (water, wastewater, and volatile environments. In these matrices, it has functioned as one of the best characterized chemically-responsive environmental bioreporters and as a model organism for understanding bacterial colonization and transport, cell immobilization strategies, and the kinetics of cellular bioluminescent emission. This review summarizes the characteristics of P. fluorescens HK44 and the extensive range of its applications with special focus on the monitoring of bioremediation processes and biosensing of environmental pollution.

Conjoint effect of oil-seed cakes and Pseudomonas fluorescens on the growth of chickpea in relation to the management of plant-parasitic nematodes

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Rose Rizvi

2012-12-01

Full Text Available Soil application of organics has been explored as an alternative means of organic management of plant-parasitic nematodes. Efficiency of different oil-seed cakes of neem (Azadirachta indica, castor (Ricinus communis, groundnut (Arachis hypogaea, linseed (Linum usitatissimum, sunflower (Helianthus annuus and soybean (Glycine max were evaluated in field conditions with association of Pseudomonas fluorescens in relation to growth parameters of chickpea and population of plant-parasitic nematodes. Their efficacious nature was highly effective in reducing the population of these dominant soil nematodes. Significant improvement was observed in plant-growth parameters such as plant weight, percent pollen fertility, pod numbers, root-nodulation and chlorophyll content of chickpea, seemed to be due to reduction in disease incidence and might be due to growth promoting substances secreted by P. fluorescens. The multiplication rate of nematodes was less in the presence of P. fluorescens as compared to its absence. Most effective combination of P. fluorescens was observed with neem cake.

Type III secretion system and virulence markers highlight similarities and differences between human- and plant-associated Pseudomonads related to Pseudomonas fluorescens and P-putida

OpenAIRE

Mazurier, Sylvie; Merieau, Annabelle; Bergeau, Dorian; Decoin, Victorien; Sperandio, Daniel; Crepin, Alexandre; Barbey, Corinne; Jeannot, Katy; Vicre-Gibouin, Maité; Plesiat, Patrick; Lemanceau, Philippe; Latour, Xavier

2015-01-01

Pseudomonas fluorescens is commonly considered a saprophytic rhizobacterium devoid of pathogenic potential. Nevertheless, the recurrent isolation of strains from clinical human cases could indicate the emergence of novel strains originating from the rhizosphere reservoir, which could be particularly resistant to the immune system and clinical treatment. The importance of type three secretion systems (T3SSs) in the related Pseudomonas aeruginosa nosocomial species and the occurrence of this se...

The Effect of Bacteria Colony Pseudomonas fluorescens (UB_Pf1 and Bacillus subtilis (UB_Bs1 on the Mortality of Pratylenchus coffeae (Tylenchida: Pratylenchidae

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Presti Mardiyani Purwaningtyas

2016-11-01

Full Text Available Parasitic Root-Lession nematode of Pratylenchus coffeae can reduce the Indonesian coffee plants productivity. Several studies reported that Pseudomonas fluorescens and Bacillus subtilis endophytic bacteria were antagonistic bacteria to nematode. The objective of this research was to reveal the effectiveness of bacterial colonies density of P. fluorescens (UB_Pf1, B.subtilis (UB BS1, and a combination of both bacteria on nematode mortality using median lethal concentration (LC50 and median lethal time 50 (LT50. The densities of bacteria used in this study were 107, 109, 1011 and 1013 cfu/ml. 35 testing nematodes were used and the mortality was counted at 6, 12, 24, 36, and 48 hours after treatments. The results showed that LC50 values of P. fluorescens was (UB_Pf1 was 4,3x108 cfu/ml, LC50 B. subtilis (UB_Bs1 was 1,9x109cfu/ ml, and LC50 combination of both bacteria was, 8x107 cfu/ml. It implies that the application of the combination of both bacteria are more pathogenic than single bacterial treatment. The results also showed that the highest LT50 value was 13.21  hours combination of bacterial colonies with a density of 1013 cfu/ml and the lowest LT50 value was 52.00 hours on P. fluorescens (UB_Pf1 treatment with colonies density of 107 cfu/ml.How to CitePurwaningtyas, P. M., Rahardjo, B. T., & Tarno, H. (2016. The Effect of Bacteria Colony Pseudomonas fluorescens (UB_Pf1 and Bacillus subtilis (UB_Bs1 on the Mortality of Pratylenchus coffeae (Tylenchida: Pratylenchidae. Biosaintifika: Journal of Biology & Biology Education, 8(3, 286-293. 

Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L.).

Science.gov (United States)

Prasad, Andhare A; Babu, Subramanian

2017-01-01

We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU) and one biocontrol agent (Pseudomonas fluorescens strain PF1) for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

Compatibility of Azospirillum brasilense and Pseudomonas fluorescens in growth promotion of groundnut ( Arachis hypogea L.

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ANDHARE A. PRASAD

Full Text Available ABSTRACT We attempted to study the compatibility among plant beneficial bacteria in the culture level by growing them near in the nutrient agar plates. Among all the bacteria tested, Rhizobium was found to inhibit the growth of other bacteria. From the compatible group of PGPR, we have selected one biofertilizer (Azospirillum brasilense strain TNAU and one biocontrol agent (Pseudomonas fluorescens strain PF1 for further studies in the pot culture. We have also developed a bioformulation which is talc powder based, for individual bacteria and mixed culture. This formulation was used as seed treatment, soil application, seedling root dip and foliar spray in groundnut crop in vitro germination conditions. A. brasilense was found to enhance the tap root growth and P. fluorescens, the lateral root growth. The other growth parameters like shoot growth, number of leaves were enhanced by the combination of both of the bacteria than their individual formulations. Among the method of application tested in our study, soil application was found to be the best in yielding better results of plant growth promotion.

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...

Pseudomonas fluorescens filamentous hemagglutinin, an iron-regulated protein, is an important virulence factor that modulates bacterial pathogenicity

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Yuan-yuan Sun

2016-08-01

Full Text Available Pseudomonas fluorescens is a common bacterial pathogen to a wide range of aquaculture animals including various species of fish. In this study, we employed proteomic analysis and identified filamentous hemagglutinin (FHA as an iron-responsive protein secreted by TSS, a pathogenic P. fluorescens isolate. In vitro study showed that compared to the wild type, the fha mutant TSSfha (i exhibited a largely similar vegetative growth profile but significantly retarded in the ability of biofilm growth and producing extracellular matrix, (ii displayed no apparent flagella and motility, (iii was defective in the attachment to host cells and unable to form self-aggregation, (iv displayed markedly reduced capacity of hemagglutination and surviving in host serum. In vivo infection analysis revealed that TSSfha was significantly attenuated in the ability of dissemination in fish tissues and inducing host mortality, and that antibody blocking of the natural FHA produced by the wild type TSS impaired the infectivity of the pathogen. Furthermore, when introduced into turbot as a subunit vaccine, recombinant FHA elicited a significant protection against lethal TSS challenge. Taken together, these results indicate for the first time that P. fluorescens FHA is a key virulence factor essential to multiple biological processes associated with pathogenicity.

Enhanced extracellular chitinase production in Pseudomonas fluorescens: biotechnological implications

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Azhar Alhasawi

2017-06-01

Full Text Available Chitin is an important renewable biomass of immense commercial interest. The processing of this biopolymer into value-added products in an environmentally-friendly manner necessitates its conversion into N-acetyl glucosamine (NAG, a reaction mediated by the enzyme chitinase. Here we report on the ability of the soil microbe Pseudomonas fluorescens to secrete copious amounts of chitinase in the spent fluid when cultured in mineral medium with chitin as the sole source of carbon and nitrogen. Although chitinase was detected in various cellular fractions, the enzyme was predominantly localized in the extracellular component that was also rich in NAG and glucosamine. Maximal amounts of chitinase with a specific activity of 80 µmol NAG produced mg–1 protein min–1 was obtained at pH 8 after 6 days of growth in medium with 0.5 g of chitin. In-gel activity assays and Western blot studies revealed three isoenzymes. The enzyme had an optimal activity at pH 10 and a temperature range of 22–38 ℃. It was stable for up to 3 months. Although it showed optimal specificity toward chitin, the enzyme did readily degrade shrimp shells. When these shells (0.1 g were treated with the extracellular chitinase preparation, NAG [3 mmoles (0.003 g-mol] was generated in 6 h. The extracellular nature of the enzyme coupled with its physico-chemical properties make this chitinase an excellent candidate for biotechnological applications.

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...

Efeito da pré-incubação de Pseudomonas fluorescens em diferentes temperaturas de refrigeração sobre a hidrólise de caseína no leite desnatado pasteurizado microfiltrado

OpenAIRE

Netto, Gabriel Gama

2012-01-01

Este trabalho objetivou avaliar o efeito da multiplicação de uma estirpe psicrotrófica proteolítica de Pseudomonas fluorescens nas temperaturas de 4, 7 e 10 ºC, estabelecidas pela Instrução Normativa 62 do MAPA, nas características físicoquímicas e proteólise do leite microfiltrado. Amostras leite desnatado e pasteurizado foram inoculadas com a cepa Pseudomonas fluorescens 041 em uma concentração de aproximadamente 104 UFC mL-1 e incubadas nas três temperaturas por 48 h e, posteriormente, ...

Biosynthesis of the antimicrobial cyclic lipopeptides nunamycin and nunapeptin by Pseudomonas fluorescens strain In5 is regulated by the LuxR-type transcriptional regulator NunF.

Science.gov (United States)

Hennessy, Rosanna C; Phippen, Christopher B W; Nielsen, Kristian F; Olsson, Stefan; Stougaard, Peter

2017-12-01

Nunamycin and nunapeptin are two antimicrobial cyclic lipopeptides (CLPs) produced by Pseudomonas fluorescens In5 and synthesized by nonribosomal synthetases (NRPS) located on two gene clusters designated the nun-nup regulon. Organization of the regulon is similar to clusters found in other CLP-producing pseudomonads except for the border regions where putative LuxR-type regulators are located. This study focuses on understanding the regulatory role of the LuxR-type-encoding gene nunF in CLP production of P. fluorescens In5. Functional analysis of nunF coupled with liquid chromatography-high-resolution mass spectrometry (LC-HRMS) showed that CLP biosynthesis is regulated by nunF. Quantitative real-time PCR analysis indicated that transcription of the NRPS genes catalyzing CLP production is strongly reduced when nunF is mutated indicating that nunF is part of the nun-nup regulon. Swarming and biofilm formation was reduced in a nunF knockout mutant suggesting that these CLPs may also play a role in these phenomena as observed in other pseudomonads. Fusion of the nunF promoter region to mCherry showed that nunF is strongly upregulated in response to carbon sources indicating the presence of a fungus suggesting that environmental elicitors may also influence nunF expression which upon activation regulates nunamycin and nunapeptin production required for the growth inhibition of phytopathogens. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Adsorption of Th(IV) and Pu(IV) on the surface of Pseudomonas fluorescens and Bacillus subtilis in the presence of desferrioxamine siderophore

International Nuclear Information System (INIS)

Yoshida, Takahiro; Ozaki, Takuo; Ohnuki, Toshihiko; Francis, Arokiasamy J.

2005-01-01

Adsorption of Th(IV) and Pu(IV) on a Gram-negative bacterium Pseudomonas fluorescens and a Gram-positive bacterium Bacillus subtilis in the presence of siderophore desferrioxamine B (DFO) was studied. Thorium(IV) and Pu(IV) were dissociated from DFO during adsorption on the cells. Thorium(IV) adsorption on bacterial cells in the presence of DFO was larger than that of Pu(IV) because of the smaller stability of the Th(IV)-DFO complex than that of the Pu(IV)-DFO complex. On the other hand, adsorption of Pu(IV) was larger than that of Fe(III), wherein the stability of the Pu(IV)- and Fe(III)-DFO complex is comparable. P. fluorescens showed a higher affinity for Th(IV) and Pu(IV) than B. subtilis, though potentiometric titration of bacterial cells indicated that surfaces of P. fluorescens and B. subtilis cells showed similar proton binding properties. (author)

INFLUÊNCIA DA ATIVIDADE ENZIMÁTICA DE PSEUDOMONAS FLUORESCENS 041 EM LABNEH

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Andreza Angélica Ferreira

2012-04-01

Full Text Available A refrigeração do leite proporciona a seleção de bactérias psicrotróficas deteriorantes produtoras de enzimas termoresistentes que podem comprometer a qualidade do leite e derivados. O objetivo deste trabalho foi avaliar as implicações causadas pela atividade enzimática de Pseudomonas fluorescens 041 na produção de Labneh. O leite pasteurizado foi inoculado intencionalmente com, aproximadamente, 106 UFC.mL-1 de P. fluorescens 041 e Labneh foi produzido imediatamente após inoculação no leite (tempo 0 e após 48, 72 e 96 horas de inoculação e armazenamento a 4 ºC. A qualidade físico-química do leite, do Labneh e do soro resultante da fabricação foi determinada. O rendimento prático, o rendimento técnico ajustado e o aproveitamento final de sólidos no Labneh em relação ao volume de leite (coeficiente GL também foram avaliados. Constatou-se alterações nas características físico-químicas do soro e do Labneh fabricado com leite armazenado a partir de 48 horas. Também, observou-se um aumento significativo em litros de leite destinado à produção de um quilo do produto ao longo do tempo de estocagem do leite inoculado com P. fluorescens 041, sendo os rendimentos prático, técnico ajustado e o coeficiente GL afetados pelo fator tempo. Portanto, a redução do tempo de estocagem do leite sob refrigeração e a prevenção da contaminação da matéria-prima por meio da adoção de boas práticas na cadeia do leite são medidas a serem adotadas para assegurar a qualidade e o rendimento do produto final.

Pseudomonas fluorescens ATCC 13525 Containing an Artificial Oxalate Operon and Vitreoscilla Hemoglobin Secretes Oxalic Acid and Solubilizes Rock Phosphate in Acidic Alfisols

Science.gov (United States)

Archana, G.; Naresh Kumar, G.

2014-01-01

Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah), Fomitopsis plaustris oxalate transporter (FpOAR) and Vitreoscilla hemoglobin (vgb) in various combinations. Pf (pKCN2) transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the presence of an artificial oxalate operon containing oah and FpOAR genes in plasmid pKCN4, Pf (pKCN4) secreted 13.6 mM oxalate in the medium while 3.6 mM remained inside. This transformant solubilized 509 μM of phosphorus from rock phosphate in alfisol which is 4.5 fold higher than the Pf (pKCN2) transformant. Genomic integrants of P. fluorescens (Pf int1 and Pf int2) containing artificial oxalate operon (plac-FpOAR-oah) and artificial oxalate gene cluster (plac-FpOAR-oah, vgb, egfp) secreted 4.8 mM and 5.4 mM oxalic acid, released 329 μM and 351 μM P, respectively, in alfisol. The integrants showed enhanced root colonization, improved growth and increased P content of Vigna radiata plants. This study demonstrates oxalic acid secretion in P. fluorescens by incorporation of an artificial operon constituted of genes for oxalate synthesis and transport, which imparts mineral phosphate solubilizing ability to the organism leading to enhanced growth and P content of V. radiata in alfisol soil. PMID:24705024

Pseudomonas fluorescens ATCC 13525 containing an artificial oxalate operon and Vitreoscilla hemoglobin secretes oxalic acid and solubilizes rock phosphate in acidic alfisols.

Directory of Open Access Journals (Sweden)

Kavita Yadav

Full Text Available Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah, Fomitopsis plaustris oxalate transporter (FpOAR and Vitreoscilla hemoglobin (vgb in various combinations. Pf (pKCN2 transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the presence of an artificial oxalate operon containing oah and FpOAR genes in plasmid pKCN4, Pf (pKCN4 secreted 13.6 mM oxalate in the medium while 3.6 mM remained inside. This transformant solubilized 509 μM of phosphorus from rock phosphate in alfisol which is 4.5 fold higher than the Pf (pKCN2 transformant. Genomic integrants of P. fluorescens (Pf int1 and Pf int2 containing artificial oxalate operon (plac-FpOAR-oah and artificial oxalate gene cluster (plac-FpOAR-oah, vgb, egfp secreted 4.8 mM and 5.4 mM oxalic acid, released 329 μM and 351 μM P, respectively, in alfisol. The integrants showed enhanced root colonization, improved growth and increased P content of Vigna radiata plants. This study demonstrates oxalic acid secretion in P. fluorescens by incorporation of an artificial operon constituted of genes for oxalate synthesis and transport, which imparts mineral phosphate solubilizing ability to the organism leading to enhanced growth and P content of V. radiata in alfisol soil.

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

OpenAIRE

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

2013-01-01

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

Detoxification of selenite and mercury by reduction and mutual protection in the assimilation of both elements by Pseudomonas fluorescens

International Nuclear Information System (INIS)

Belzile, Nelson; Wu Gaojun; Chen, Yu-Wei; Appanna, Vasu D.

2006-01-01

A study on the assimilation and detoxification of selenium and mercury and on the interaction between these two elements was conducted on Pseudomonas fluorescens. P. fluorescens was able to convert separately both elements to their elemental forms, which are less toxic and biologically less available. To study the converting mechanism of selenite to elemental Se, cells were grown in the presence of various selenite concentrations and several parameters such as extracellular protein concentrations, pH, carbohydrate concentrations, isocitrate dehydrogenase (ICDH) and malic enzyme were monitored. Transmission electron microscopy (TEM) and various analytical methods were applied to confirm the interaction between selenium and cell. The former appeared as a red precipitate localized predominantly in the consumed culture medium. P. fluorescens also resisted to the toxic effect of mercury by converting Hg 2+ to the volatile and less toxic form Hg . Mercury reductase was likely responsible for the conversion of Hg 2+ to Hg . More importantly, the interaction between mercury and selenium was also studied. The presence of selenite significantly reduced the accumulation of mercury in P. fluorescens. It was also interesting to note that mercury appeared to behave as a protecting agent against selenium intoxication as the bioaccumulation of Se was also inhibited by this metal. The formation of Se-Hg complexes could explain this mutual protective effect. No precipitate of elemental Se could be detected when Hg was present in the cultures

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...

Extracellular Protease of Pseudomonas fluorescens CHA0, a Biocontrol Factor with Activity against the Root-Knot Nematode Meloidogyne incognita

OpenAIRE

Siddiqui, Imran Ali; Haas, Dieter; Heeb, Stephan

2005-01-01

In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocon...

Efficacy of Pseudomonas fluorescens (Pf-CL145A) spray dried powder for controlling zebra mussels adhering to test substrates

Science.gov (United States)

Luoma, James A.; Severson, Todd J.; Weber, Kerry L.; Mayer, Denise A.

2015-01-01

A mobile bioassay trailer was used to assess the efficacy of Pseudomonas fluorescens (Pf-CL145A) spray dried powder (SDP) formulation for controlling zebra mussels (Dreissena polymorpha) from two midwestern lakes: Lake Carlos (Alexandria, Minnesota) and Shawano Lake (Shawano, Wisconsin). The effects of SDP exposure concentration and exposure duration on zebra mussel survival were evaluated along with the evaluation of a benthic injection application technique to reduce the amount of SDP required to induce zebra mortality.

Structure of a putative BenF-like porin from Pseudomonas fluorescens Pf-5 at 2.6 A resolution

Energy Technology Data Exchange (ETDEWEB)

Sampathkumar, P.; Swaminathan, S.; Lu, F.; Zhao, X.; Li, Z.; Gilmore, J.; Bain, K.; Rutter, M. E.; Gheyi, T.; Schwinn, D.; Bonanno, J. B.; Pieper, U.; Fajardo, J. E.; Fiser, A.; Almo, S. C.; Chance, M. R.; Baker, D.; Atwell, S.; Thompson, D. A.; Emtage, J. S.; Wasserman, S. R.; Sali, A.; Sauder, J. M.; Burley, S. K.

2010-11-01

Gram-negative bacteria typically overcome poor permeability of outer membranes through general porins like OmpF and OmpC, which form water-filled transmembrane pores permitting diffusion of hydrophilic molecules with no particular selectivity. Many bacteria lacking such general porins use substrate-specific porins to overcome growth-limiting conditions and facilitate selective transport of metabolites. Exclusive reliance on substrate-specific porins yields lower membrane permeability to small molecules (<600 Da) versus that seen for Escherichia coli. In Pseudomonads, transit of most small molecules across the cell membrane is thought to be mediated by substrate-specific channels of the OprD superfamily. This property explains, at least in part, the high incidence of Pseudomonas aeruginosa antibiotic resistance. High-throughput DNA sequencing of the P. aeruginosa chromosome revealed the presence of 19 genes encoding structurally related, substrate-specific porins (with 30-45% pairwise amino acid sequence identity) that mediate transmembrane passage of small, water-soluble compounds. The OprD superfamily encompasses the eponymous OprD subfamily, which includes 9 P. aeruginosa proteins that convey basic amino acids and carbapenem antibiotics, and the OpdK subfamily, which includes 11 P. aeruginosa proteins that convey aromatic acids and other small aromatic compounds. Genome sequencing of other gram-negative bacteria has revealed additional members of the OprD and OpdK subfamilies in various organisms, including other pseudomonads. Among the many bacteria in which OprD superfamily members have been identified are P. putida, P. fluorescens Pf-5, P. syringae, and Azotobacter vinelandii, all of which share closely related genes that encode the so-called BenF-like porins. In P. putida, benF is part of an operon involved in benzoate catabolism regulated by benR. Within this operon, benK, benE, and benF genes have been suggested to contribute toward either influx or efflux

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 ...

Extracellular Protease of Pseudomonas fluorescens CHA0, a Biocontrol Factor with Activity against the Root-Knot Nematode Meloidogyne incognita

Science.gov (United States)

Siddiqui, Imran Ali; Haas, Dieter; Heeb, Stephan

2005-01-01

In Pseudomonas fluorescens CHA0, mutation of the GacA-controlled aprA gene (encoding the major extracellular protease) or the gacA regulatory gene resulted in reduced biocontrol activity against the root-knot nematode Meloidogyne incognita during tomato and soybean infection. Culture supernatants of strain CHA0 inhibited egg hatching and induced mortality of M. incognita juveniles more strongly than did supernatants of aprA and gacA mutants, suggesting that AprA protease contributes to biocontrol. PMID:16151170

Listeria monocytogenes impact on mature or old Pseudomonas fluorescens biofilms during growth at 4 and 20ºC

Directory of Open Access Journals (Sweden)

Puga eCH

2016-02-01

Full Text Available Changes in spatial organization, as observed by confocal laser scanning microscopy (CLSM, viable cell content, biovolume and substratum surface coverage of the biofilms formed on glass by Pseudomonas fluorescens resulting from co-culture with Listeria monocytogenes, were examined. Two strains of L. monocytogenes, two culture temperatures and two biofilm developmental stages were investigated. Both L. monocytogenes strains, a persistently sampled isolate (collected repeatedly along 3 years from a meat factory and Scott A, induced shrinkage in matrix volume, both at 20ºC and 4ºC, in mature or old biofilms, without loss of P. fluorescens cell count per surface unit. The nearly homogeneous pattern of surface coverage shown by mono-species P. fluorescens biofilms, turned into more irregular layouts in co-culture with L. monocytogenes. The upper layer of both mono and dual-species biofilms turned to predominantly consist of matrix, with plenty of viable cells underneath, in old biofilms cultured at 20ºC, but not in those grown at 4ºC. Between 15 and 56% of the substratum area was covered by biofilm, the extent depending on temperature, time and L. monocytogenes strain. Real biofilms in food-related surfaces may thus be very heterogeneous regarding their superficial components, i.e. those more accessible to disinfectants. It is therefore a hygienic challenge to choose an adequate agent to disrupt them.

Enlightening mineral iron sensing in Pseudomonas fluorescens by surface active maghemite nanoparticles: Involvement of the OprF porin.

Science.gov (United States)

Magro, Massimiliano; Fasolato, Luca; Bonaiuto, Emanuela; Andreani, Nadia Andrea; Baratella, Davide; Corraducci, Vittorino; Miotto, Giovanni; Cardazzo, Barbara; Vianello, Fabio

2016-10-01

Mineral iron(III) recognition by bacteria is considered a matter of debate. The peculiar surface chemistry of novel naked magnetic nanoparticles, called SAMNs (surface active maghemite nanoparticles) characterized by solvent exposed Fe(3+) sites on their surface, was exploited for studying mineral iron sensing in Pseudomonas fluorescens. SAMNs were applied for mimicking Fe(3+) ions in solution, acting as magnetically drivable probes to evaluate putative Fe(3+) recognition sites on the microorganism surface. Culture broths and nano-bio-conjugates were characterized by UV-Vis spectroscopy and mass spectrometry. The whole heritage of a membrane porin (OprF) of P. fluorescens Ps_22 cells was recognized and firmly bound by SAMNs. The binding of nanoparticles to OprF porin was correlated to a drastic inhibition of a siderophore (pyoverdine) biosynthesis and to the stimulation of the production and rate of formation of a secondary siderophore. The analysis of metabolic pathways, based on P. fluorescens Ps_22 genomic information, evidenced that this putative secondary siderophore does not belong to a selection of the most common siderophores. In the scenario of an adhesion mechanism, it is plausible to consider OprF as the biological component deputed to the mineral iron sensing in P. fluorescens Ps_22, as well as one key of siderophore regulation. The present work sheds light on mineral iron sensing in microorganisms. Peculiar colloidal naked iron oxide nanoparticles offer a useful approach for probing the adhesion of bacterial surface on mineral iron for the identification of the specific recognition site for this iron uptake regulation in microorganisms. Copyright © 2016 Elsevier B.V. All rights reserved.

Physiological and biochemical changes in Matricaria chamomilla induced by Pseudomonas fluorescens and water deficit stress

Directory of Open Access Journals (Sweden)

Hamid MOHAMMADI

2018-04-01

Full Text Available Environmental stresses and rhizosphere microorganisms affect growth parameters and accumulation of active ingredients especially in plants with medicinal properties. The present study examined the effects of chamomile (Matricaria chamomilla L. seedling inoculation with Pseudomonas fluorescens PF-135 strain on its growth parameters, photosynthetic pigments, proline, malondialdehyde (MDA, and hydrogen peroxide (H2O2 content, and essential oil concentration at both regular watering and water deficit experiments. Based on the obtained results, water deficit stress reduced root dry mass, and flower fresh and dry mass as well. However, amount of H2O2 and MDA in root and shoot tissues were considerably lower in inoculated plants compared to non-inoculated ones under both normal watering and water deficit regimes. It indicates that lipid peroxidation and production of reactive oxygen species has been diminished in inoculated plants. Also, essential oil content in inoculated plants significantly increased compared with that of non-inoculated ones under water deficit stress condition. It can be concluded that P. fluorescens PF-135 strain has an outstanding potential to alleviate adverse effects of water deficit on plant growth, and hence can be used as an excellent PGPR in order to boost chamomile productivity especially under water deficit stress condition.

A phosphate-starvation-inducible outermembrane protein of Pseudomonas fluorescens Ag1 as an immunological phosphate-starvation marker

DEFF Research Database (Denmark)

Leopold, Kristine; Jacobsen, Susanne; Nybroe, Ole

1997-01-01

A phosphate-starvation-inducible outer-membrane protein of Pseudomonas fluorescens Ag1, expressed at phosphate concentrations below0.08-0.13 mM, was purified and characterized. The purification method involved separation of outer-membrane proteins by SDS-PAGE andextraction of the protein from...... nitrocellulose or PVDF membranes after electrotransfer of proteins to the membranes. The N-terminal amino acidsequence of the purified protein, called Psi1, did not show homology to any known proteins, and in contrast to the phosphate-specific porin OprP ofP. aeruginosa its mobility in SDS-PAGE was not affected...

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

KAUST Repository

Stabler, R. A.

2013-01-24

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

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

Science.gov (United States)

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

2013-01-01

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

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

KAUST Repository

Stabler, R. A.; Negus, D.; Pain, Arnab; Taylor, P. W.

2013-01-01

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

Investigating the ability of Pseudomonas fluorescens UW4 to reduce cadmium stress in Lactuca sativa via an intervention in the ethylene biosynthetic pathway.

Science.gov (United States)

Albano, Lucas J; Macfie, Sheila M

2016-12-01

A typical plant response to any biotic or abiotic stress, including cadmium (Cd), involves increased ethylene synthesis, which causes senescence of the affected plant part. Stressed plants can experience reduced ethylene and improved growth if they are inoculated with bacteria that have the enzyme ACC deaminase, which metabolizes the ethylene precursor ACC (1-aminocyclopropane-1-carboxylate). We investigated whether one such bacterium, Pseudomonas fluorescens UW4, reduces the production of ethylene and improves the growth of lettuce (Lactuca sativa) sown in Cd-contaminated potting material (PRO-MIX® BX). Plants were inoculated with the wild-type P. fluorescens UW4 or a mutant strain that cannot produce ACC deaminase. Cadmium-treated plants contained up to 50 times more Cd than did control plants. In noninoculated plants, Cd induced a 5-fold increase in ethylene concentration. The wild-type bacterium prevented Cd-induced reductions in root biomass but there was no relationship between Cd treatment and ethylene production in inoculated plants. In contrast, when the concentration of ethylene was plotted against the extent of bacterial colonization of the roots, increased colonization with wild-type P. fluorescens UW4 was associated with 20% less ethylene production. Ours is the first study to show that the protective effect of this bacterium is proportional to the quantity of bacteria on the root surface.

Effect of Eu(III) on the degradation of malic acid by Pseudomonas fluorescens

International Nuclear Information System (INIS)

Nankawa, T.; Ozaki, T.; Ohnuki, T.; Suzuki, Y.; Francis, A.J.

2005-01-01

Full text of publication follows: The transuranic elements, such as Am(III) and Cm(III), are highly toxic because they emit high-energy α particles and have long half-lives. To estimate their long-term environmental behavior, we need to elucidate degradation of actinide-organic complexes by microorganisms. We studied the biodegradation of Eu(III)-malic acid complexes by Pseudomonas fluorescens. Malic acid is ubiquitous in the environment and is one of the microbial metabolites that is part of the tri-carboxylic acid (TCA) cycle. Europium(III) is a good analogue for Am(III) and Cm(III). To investigate the effect of Eu(III) on the degradation of malic acid by P. fluorescens, we compared the degradation behavior of Eu(III)-malic acid complexes to that of Fe(III) and Al(III)-malic acid complexes. In the medium containing 1 mM malic acid and 0-0.5 mM Fe(III), malic acid was degraded completely. In the medium containing 1 mM malic acid and 0.05-0.5 mM Al(III), malic acid was degraded until the concentration of malic acid became equal to that of Al(III), indicating that Al(III)-malic acid complex with 1: 1 molar ratio was recalcitrant to biodegradation. In the medium containing 1 mM malic acid and 0.05-0.5 mM Eu(III), degradation of malic acid was not observed. The effect of metals on degradation of malic acid was in the order of Fe(III) < Al(III) < Eu(III). The stability constants of 1:1 Fe(III)-, Al(III)-, and Eu(III)-malic acid complexes are 7.1, 4.6, and 4.9, respectively. These results indicate that degradability of malic acid does not depend on the stability constants of metal-malic acid complexes. We found that 10 mM malic acid was degraded in the presence of 0.05 and 0.1 mM Eu(III) but 1 mM malic acid was not degraded in the presence of 0.05 and 0.1 mM Eu(III). The degradation rate of malic acid increased with a decreasing ratio of Eu(III) to malic acid. (authors)

Pseudomonas fluorescens' view of the periodic table.

Science.gov (United States)

Workentine, Matthew L; Harrison, Joe J; Stenroos, Pernilla U; Ceri, Howard; Turner, Raymond J

2008-01-01

Growth in a biofilm modulates microbial metal susceptibility, sometimes increasing the ability of microorganisms to withstand toxic metal species by several orders of magnitude. In this study, a high-throughput metal toxicity screen was initiated with the aim of correlating biological toxicity data in planktonic and biofilm cells to the physiochemical properties of metal ions. To this end, Pseudomonas fluorescens ATCC 13525 was grown in the Calgary Biofilm Device (CBD) and biofilms and planktonic cells of this microorganism were exposed to gradient arrays of different metal ions. These arrays included 44 different metals with representative compounds that spanned every group of the periodic table (except for the halogens and noble gases). The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum biofilm eradication concentration (MBEC) values were obtained after exposing the biofilms to metal ions for 4 h. Using these values, metal ion toxicity was correlated to the following ion-specific physicochemical parameters: standard reduction-oxidation potential, electronegativity, the solubility product of the corresponding metal-sulfide complex, the Pearson softness index, electron density and the covalent index. When the ions were grouped according to outer shell electron structure, we found that heavy metal ions gave the strongest correlations to these parameters and were more toxic on average than the other classes of the ions. Correlations were different for biofilms than for planktonic cells, indicating that chemical mechanisms of metal ion toxicity differ between the two modes of growth. We suggest that biofilms can specifically counter the toxic effects of certain physicochemical parameters, which may contribute to the increased ability of biofilms to withstand metal toxicity.

Effect of Two Biological Formulations Based on Bacillus subtilis and Pseudomonas fluorescens on Control of Didymella applanata, the Causal Agent of Red Raspberry Cane Spur Blight

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Margarita Shternshis

2016-01-01

Full Text Available In vitro and in vivo studies were conducted to estimate the efficacy of the two microbial formulations based on Bacillus subtilis Cohn. and Pseudomonas fluorescens Mig. on the fungus Didymella applanata (Niessl. Sacc., the causal agent of red raspberry (Rubus idaeus L. spur blight. In vitro, both bacteria reduced the growth of D. applanata. In inoculation experiments with raspberry canes in two cultivars with different susceptibility to D. applanata, these antagonistic bacteria suppressed fungal development by reducing the lesions area and the number of D. applanata fruiting bodies. Field trials of two biological formulations under natural conditions showed a significant suppression of the disease. B. subtilis and P. fluorescens included in the formulations revealed antagonistic activity towards D. applanata that depended on the red raspberry cultivar and weather conditions. In all cases, B. subtilis showed better results than P. fluorescens in biocontrol of the raspberry spur blight. This study demonstrated for the first time the ability of the biocontrol agents B. subtilis and P. fluorescens to suppress red raspberry cane spur blight, a serious worldwide disease.

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 ...

Effect of Pseudomonas fluorescens and pyoverdine on the phytoextraction of cesium by red clover in soil pots and hydroponics.

Science.gov (United States)

Hazotte, Alice; Péron, Olivier; Gaudin, Pierre; Abdelouas, Abdesselam; Lebeau, Thierry

2018-05-12

With the aim of improving the phytoextraction rate of cesium (Cs), the effect of Pseudomonas fluorescens ATCC 17400 and its siderophore pyoverdine (PVD) on the uptake of Cs by red clover was studied in soil pots. This work also provides a mechanistic understanding of the Cs-bacteria (or PVD)-illite-plant interactions by using a simplified experimental design, i.e., hydroponics with either Cs in solution or Cs-spiked illite in suspension. For soil spiked with 11.2 mmol kg -1 (1480 mg kg -1 ) of Cs, 0.43% of total Cs was taken up by red clover in 12 days (119 μmol g -1 (16 mg g -1 ) of Cs dry matter in roots and 40 μmol g -1 (5 mg g -1 ) in shoots). In hydroponics with Cs in solution (0.1 mmol L -1 or 13 mg L -1 ), 75% of Cs was taken up vs. only 0.86% with Cs-spiked illite suspension. P. fluorescens and PVD did not increase Cs concentrations in aboveground parts and roots of red clover and even decreased them. The damaging effect of PVD on red clover growth was demonstrated with the biomass yielding 66% of the control in soil pots (and 100% mortality after 12 days of exposition) and only 56% in hydroponics (78% with illite in suspension). Nonetheless, PVD and, to a lesser extent, P. fluorescens increased the translocation factor up to a factor of 2.8. This study clearly showed a direct damaging effect of PVD and to a lower extent the retention of Cs by biofilm covering both the roots and illite, both resulting in the lower phytoextraction efficiency.

Non-pathogenic Fusarium solani represses the biosynthesis of nematicidal compounds in vitro and reduces the biocontrol of Meloidogyne javanica by Pseudomonas fluorescens in tomato.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S

2003-01-01

The aim of the present investigation was to determine the influence of various Fusarium solani strains on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Culture filtrates (CF) of P. fluorescens strain CHA0 and its diacetylphloroglucinol-overproducing derivative CHA0/pME3424 caused substantial mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with the growth medium of F. solani repressed the nematicidal activity of the bacteria. Methanol extract of F. solani CF resulting from Czapek's Dox liquid (CDL) medium without zinc amendment repressed the nematicidal activity of the bacteria while the CF obtained from CDL medium amended with zinc did not. Conidial suspension of F. solani strain Fs5 (repressor strain for the biosynthesis of nematicidal compounds in P. fluorescens) reduced biocontrol potential of the bacterial inoculants against M. javanica in tomato while strain Fs3 (non-repressor) did not. Fusarium solani strains with increased nematicidal activity repress the biosynthesis of nematicidal compounds by P. fluorescens strains in vitro and greatly alter its biocontrol efficacy against root-knot nematode under natural conditions. Fusarium solani strains are distributed worldwide and found in almost all the agricultural fields which suggest that some mycotoxin-producing strains will also be found in almost any soil sample taken. Besides the suppressive effect of these metabolite-producing strains on the production of nematicidal compound(s) critical in biocontrol, F. solani strains may also affect the performance of mycotoxin-sensitive biocontrol bacteria effective against plant-parasitic nematodes.

Measurement of glucose utilization by Pseudomonas fluorescens that are free-living and that are attached to surfaces

International Nuclear Information System (INIS)

Fletcher, M.

1986-01-01

The assimilation and respiration of glucose by attached and free-living Pseudomonas fluorescens were compared. The attachment surfaces were polyvinylidene fluoride, polyethylene, and glass. Specific uptake of [ 1 C]glucose was determined after bacterial biomass was measured by (1) microscopic counts or (2) prelabelling of cells by providing [ 3 H]leucine as substrate, followed by dual-labelling scintillation counting. The glucose concentration was 1.4, 3.5, 5.5, 7.6, or 9.7 μM. Glucose assimilation by cells which became detached from the surfaces during incubation with glucose was also measured after the detached cells were collected by filtration. The composition of the substratum had no effect on the amount of glucose assimilated by attached cells. Glucose assimilation by attached cells exceeded that by free-living cells by a factor of between 2 and 5 or more, and respiration of glucose by surface-associated cells was greater than that by free-living bacteria. Glucose assimilation by detached cells was greater than that by attached bacteria. Measurements of biomass by microscopic counts gave more consistent results than those obtained with dual-labelling, but in general, results obtained by both methods were corroborative

D-glucose-6-phosphate dehydrogenase (Entner-Doudoroff enzyme) from Pseudomonas fluorescens

International Nuclear Information System (INIS)

Lessmann, D.; Schimz, K.L.; Kurz, G.

1975-01-01

The existence of two different D-glucose-6-phosphate dehydrogenases in Pseudomonas fluorescens has been demonstrated. Based on their different specificity and their different metabolic regulation one enzyme is appointed to the Entner-Doudoroff pathway and the other to the hexose monophosphate pathway. A procedure is described for the isolation of that D-glucose-6-phosphate dehydrogenase which forms part of the Entner-Doudoroff pathway (Entner-Doudoroff enzyme). A 950-fold purification was achieved with an overall yield of 44%. The final preparation, having a specific activity of about 300μmol NADH formed per min per mg protein, was shown to be homogeneous. The molecular weight of the Entner-Doudoroff enzyme has been determined to be 220,000 by gel permeation chromatography, and that of the other enzyme (Zwischenferment) has been shown to be 265,000. The pI of the Entner-Doudoroff enzyme has been shown to be 5.24 and that of the Zwischenferment 4.27. The Entner-Doudoroff enzyme is stable in the range of pH 6 to 10.5 and shows its maximal acivity at pH 8.9. The Entner-Doudoroff enzyme showed specificity for NAD + as well as for NADP + and exhibited homotropic effects for D-glucose 6-phosphate. It is inhibited by ATP which acts as a negative allosteric effector. Other nucleoside triphosphates as well as ADP are also inhibitory. The enzyme catalyzes the transfer of the axial hydrogen at carbon-1 of β-D-glucopyranose 6-phosphate to the si face of carbon-4 of the nicotinamide ring and must be classified as B-side stereospecific dehydrogenase. (orig.) [de

Exposure-related effects of Pseudomonas fluorescens, strain CL145A, on coldwater, coolwater, and warmwater fish

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Denise A. Mayer,

2015-01-01

The exposure-related effects of a commercially prepared spray-dried powder (SDP) formulation of Pseudomonas fluorescens, strain CL145A, were evaluated on coldwater, coolwater, and warmwater fish endemic to the Great Lakes and Upper Mississippi River Basins. Nine species of young-of-the-year fish were exposed to SDP for 24 hours by using continuous-flow, serial-dilution exposure systems at temperatures of 12 degrees Celsius (°C; 2 species; Oncorhynchus mykiss [rainbow trout] and Salvelinus fontinalis [brook trout]), 17 °C (3 species; Perca flavescens [yellow perch], Sander vitreus [walleye], and Acipenser fulvescens [lake sturgeon]), or 22 °C (4 species; Micropterus salmoides [largemouth bass], Micropterus dolomieu [smallmouth bass], Lepomis macrochirus [bluegill sunfish], and Ictalurus punctatus [channel catfish]).

Pseudomonas fluorescens ATCC 13525 Containing an Artificial Oxalate Operon and Vitreoscilla Hemoglobin Secretes Oxalic Acid and Solubilizes Rock Phosphate in Acidic Alfisols

OpenAIRE

Yadav, Kavita; Kumar, Chanchal; Archana, G.; Naresh Kumar, G.

2014-01-01

Oxalate secretion was achieved in Pseudomonas fluorescens ATCC 13525 by incorporation of genes encoding Aspergillus niger oxaloacetate acetyl hydrolase (oah), Fomitopsis plaustris oxalate transporter (FpOAR) and Vitreoscilla hemoglobin (vgb) in various combinations. Pf (pKCN2) transformant containing oah alone accumulated 19 mM oxalic acid intracellularly but secreted 1.2 mM. However, in the presence of an artificial oxalate operon containing oah and FpOAR genes in plasmid pKCN4, Pf (pKCN4) s...

Role of ptsP, orfT, and sss recombinase genes in root colonization by Pseudomonas fluorescens Q8r1-96.

Science.gov (United States)

Mavrodi, Olga V; Mavrodi, Dmitri V; Weller, David M; Thomashow, Linda S

2006-11-01

Pseudomonas fluorescens Q8r1-96 produces 2,4-diacetylphloroglucinol (2,4-DAPG), a polyketide antibiotic that suppresses a wide variety of soilborne fungal pathogens, including Gaeumannomyces graminis var. tritici, which causes take-all disease of wheat. Strain Q8r1-96 is representative of the D-genotype of 2,4-DAPG producers, which are exceptional because of their ability to aggressively colonize and maintain large populations on the roots of host plants, including wheat, pea, and sugar beet. In this study, three genes, an sss recombinase gene, ptsP, and orfT, which are important in the interaction of Pseudomonas spp. with various hosts, were investigated to determine their contributions to the unusual colonization properties of strain Q8r1-96. The sss recombinase and ptsP genes influence global processes, including phenotypic plasticity and organic nitrogen utilization, respectively. The orfT gene contributes to the pathogenicity of Pseudomonas aeruginosa in plants and animals and is conserved among saprophytic rhizosphere pseudomonads, but its function is unknown. Clones containing these genes were identified in a Q8r1-96 genomic library, sequenced, and used to construct gene replacement mutants of Q8r1-96. Mutants were characterized to determine their 2,4-DAPG production, motility, fluorescence, colony morphology, exoprotease and hydrogen cyanide (HCN) production, carbon and nitrogen utilization, and ability to colonize the rhizosphere of wheat grown in natural soil. The ptsP mutant was impaired in wheat root colonization, whereas mutants with mutations in the sss recombinase gene and orfT were not. However, all three mutants were less competitive than wild-type P. fluorescens Q8r1-96 in the wheat rhizosphere when they were introduced into the soil by paired inoculation with the parental strain.

Ferric-Pyoverdine Recognition by Fpv Outer Membrane Proteins of Pseudomonas protegens Pf-5

Science.gov (United States)

Hartney, Sierra L.; Mazurier, Sylvie; Girard, Maëva K.; Mehnaz, Samina; Davis, Edward W.; Gross, Harald; Lemanceau, Philippe

2013-01-01

The soil bacterium Pseudomonas protegens Pf-5 (previously called P. fluorescens Pf-5) produces two siderophores, enantio-pyochelin and a compound in the large and diverse pyoverdine family. Using high-resolution mass spectroscopy, we determined the structure of the pyoverdine produced by Pf-5. In addition to producing its own siderophores, Pf-5 also utilizes ferric complexes of some pyoverdines produced by other strains of Pseudomonas spp. as sources of iron. Previously, phylogenetic analysis of the 45 TonB-dependent outer membrane proteins in Pf-5 indicated that six are in a well-supported clade with ferric-pyoverdine receptors (Fpvs) from other Pseudomonas spp. We used a combination of phylogenetics, bioinformatics, mutagenesis, pyoverdine structural determinations, and cross-feeding bioassays to assign specific ferric-pyoverdine substrates to each of the six Fpvs of Pf-5. We identified at least one ferric-pyoverdine that was taken up by each of the six Fpvs of Pf-5. Functional redundancy of the Pf-5 Fpvs was also apparent, with some ferric-pyoverdines taken up by all mutants with a single Fpv deletion but not by a mutant having deletions in two of the Fpv-encoding genes. Finally, we demonstrated that phylogenetically related Fpvs take up ferric complexes of structurally related pyoverdines, thereby establishing structure-function relationships that can be employed in the future to predict the pyoverdine substrates of Fpvs in other Pseudomonas spp. PMID:23222724

Análisis de las polihidroxialcanoato sintasas (PhaC1 y PhaC2 en una cepa de Pseudomonas fluorescens IBUN S1602, aislada en suelos colombianos

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Julieth Serrano Riaño

2011-07-01

Full Text Available Título en ingles: Analysis of polyhydroxyalkanoate synthases (PhaC1 and PhaC2 in a strain of Pseudomonas fluorescens   IBUN S1602 isolated from Colombian soil. Resumen La cepa Pseudomonas fluorescens IBUN S1602 conforma el grupo de aislamientos provenientes de suelos colombianos de caña de azúcar, que acumula polihidrioxialcanoato (PHA, fue seleccionada como promisoria para escalamiento comercial por tener afinidad por sustratos alternativos y económicos como el glicerol, aceites usados, suero de leche, entre otros. Dada la importancia de la enzima sintasa en la síntesis de los PHAs, en el presente trabajo se realizó el análisis molecular de los genes phaC1 y phaC2 que codifican las enzimas sintasas tipo II (PhaC1 y PhaC2. Para la obtención de los amplímeros requeridos en la secuenciación, se utilizó la técnica de PCR bajo condiciones estandarizadas para iniciadores diseñados reportados en las bases de datos. Se identificaron dos fragmentos de 1680 pb y 1683 pb correspondientes a  phaC1 y phaC2. El análisis comparativo de las secuencias proteicas resultantes de estos genes demuestra que la sintasa  IBUN S1602 contiene la región α/β hidrolasa y 8 residuos de aminoácidos conservados, que son características de las sintasas examinadas a nivel mundial. Se analizó la estructura enzimática a nivel primario y se predijo la secundaria. Se concluyó que  las sintasas de la cepa Pseudomonas fluorescens IBUN S1602 presentan alta homología con las sintasas tipo II  que se reportan para Pseudomonas. Los resultados obtenidos contribuyen al entendimiento básico de la biosíntesis de PHA,  la cual permitirá, en un futuro, el aumento de la calidad de PHA debida a la modulación del nivel de sintasa que se exprese en un organismo recombinante, con el fin de variar el peso molecular del biopolímero, propiedad esencial en el estudio de aplicaciones industriales.   Palabras clave: polihidroxialcanoatos, PHA sintasa, bioinform

Chemical sanitizers to control biofilms formed by two Pseudomonas species on stainless steel surface

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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.

Role of gallic and p-coumaric acids in the AHL-dependent expression of flgA gene and in the process of biofilm formation in food-associated Pseudomonas fluorescens KM120.

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Myszka, Kamila; Schmidt, Marcin T; Białas, Wojciech; Olkowicz, Mariola; Leja, Katarzyna; Czaczyk, Katarzyna

2016-09-01

In the process of Pseudomonas fluorescens biofilm formation, N-acyl-l-homoserine lactone (AHL)-mediated flagella synthesis plays a key role. Inhibition of AHL production may attenuate P. fluorescens biofilm on solid surfaces. This work validated the anti-biofilm properties of p-coumaric and gallic acids via the ability of phenolics to suppress AHL synthesis in P. fluorescens KM120. The dependence between synthesis of AHL molecules, expression of flagella gene (flgA) and the ability of biofilm formation by P. fluorescens KM120 on a stainless steel surface (type 304L) was also investigated. Research was carried out in a purpose-built flow cell device. Limitations on AHL synthesis in P. fluorescens KM120 were observed at concentrations of 120 and 240 µmol L(-1) of phenolic acids in medium. At such levels of gallic and p-coumaric acids the ability of P. fluorescens KM120 to synthesize 3-oxo-C6-homoserine lactone (HSL) was not observed. These concentrations caused decreased expression of flgA gene in P. fluorescens KM120. The changes in expression of AHL-dependent flgA gene significantly decreased the rate of microorganism colonization on the stainless steel surface. Phenolic acids are able to inhibit biofilm formation. The results obtained in the work may help to develop alternative techniques for anti-biofilm treatment in the food industry. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

International Nuclear Information System (INIS)

Dagbert, Catherine; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle

2008-01-01

Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

Pit formation on stainless steel surfaces pre-treated with biosurfactants produced by Pseudomonas fluorescens

Energy Technology Data Exchange (ETDEWEB)

Dagbert, Catherine [ECP-LGPM, Grande Voie des Vignes, 92295 Chatenay-Malabry (France)], E-mail: catherine.dagbert@ecp.fr; Meylheuc, Thierry; Bellon-Fontaine, Marie-Noelle [INRA, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France); AGROPARISTECH, UMR 763 Bioadhesion et Hygiene des Materiaux, F-91300 Massy (France)

2008-12-01

Today, it is widely established that the surface tension of water can be reduced by some microorganisms capable of synthesizing surface-active compounds called biosurfactants (BS). BS characteristics depend on the microorganism that produces them and therefore, on the microorganism culture conditions. Some studies on chemical surfactants have shown that the adsorption of surface-active compounds plays a major role in corrosion; indeed they are used as a good corrosion inhibition tool. The purpose of this study was first, to estimate the importance and behavior of the stainless steels passive film on the adsorption of BS, produced by the Gram negative bacteria Pseudomonas fluorescens, and secondly, to study the impact of these treatments on the pitting corrosion. In this paper, the galvanostatic polarization technique, used as accelerated method for determining the characteristic pit potentials on stainless steels, is examined. Pit growth, shape and cover formation were also observed. The surface topography of the corroded specimens was investigated using field emission scanning electron microscopy (FESEM)

Dicty_cDB: Contig-U14564-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available |pid:none) Pseudomonas fluorescens SBW25 c... 32 9.8 DQ447651_7( DQ447651 |pid:none) Lake Victoria marburgv...uschii clone CDS3047 al... 32 9.8 DQ447650_7( DQ447650 |pid:none) Lake Victoria marburgvirus - DRC19... 32 9

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.

Lipopeptide biosurfactant viscosin enhances dispersal of Pseudomonas fluorescens SBW25 biofilms.

Science.gov (United States)

Bonnichsen, Lise; Bygvraa Svenningsen, Nanna; Rybtke, Morten; de Bruijn, Irene; Raaijmakers, Jos M; Tolker-Nielsen, Tim; Nybroe, Ole

2015-12-01

Pseudomonads produce several lipopeptide biosurfactants that have antimicrobial properties but that also facilitate surface motility and influence biofilm formation. Detailed studies addressing the significance of lipopeptides for biofilm formation and architecture are rare. Hence, the present study sets out to determine the specific role of the lipopeptide viscosin in Pseudomonas fluorescens SBW25 biofilm formation, architecture and dispersal, and to relate viscA gene expression to viscosin production and effect. Initially, we compared biofilm formation of SBW25 and the viscosin-deficient mutant strain SBW25ΔviscA in static microtitre assays. These experiments demonstrated that viscosin had little influence on the amount of biofilm formed by SBW25 during the early stages of biofilm development. Later, however, SBW25 formed significantly less biofilm than SBW25ΔviscA. The indication that viscosin is involved in biofilm dispersal was confirmed by chemical complementation of the mutant biofilm. Furthermore, a fluorescent bioreporter showed that viscA expression was induced in biofilms 4 h prior to dispersal. Subsequent detailed studies of biofilms formed in flow cells for up to 5 days revealed that SBW25 and SBW25ΔviscA developed comparable biofilms dominated by well-defined, mushroom-shaped structures. Carbon starvation was required to obtain biofilm dispersal in this system. Dispersal of SBW25 biofilms was significantly greater than of SBW25ΔviscA biofilms after 3 h and, importantly, carbon starvation strongly induced viscA expression, in particular for cells that were apparently leaving the biofilm. Thus, the present study points to a role for viscosin-facilitated motility in dispersal of SBW25 biofilms.

Chemical sanitizers to control biofilms formed by two Pseudomonas species on stainless steel surface Sanificantes químicos no controle de biofilmes formados por duas espécies de Pseudomonas em superfície de aço inoxidável

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.A capacidade de adesão e formação de biofilme por Pseudomonas aeruginosa e Pseudomonas fluorescens em aço inoxidável AISI 304, na presença de leite desnatado resconstituído sobre diferentes temperaturas foi conduzido e o potencial de três sanificantes químicos na remoção de biofilmes monoespécies foi comparado. Pseudomonas aeruginosa cultivada em leite desnatado a 28 °C apresentou melhor crescimento (10,4 log UFC.mL-1 quando comparado com 3,7 and 4,2 log UFC.mL-1 para P. aeruginosa e P. fluorescens cultivadas a 7 °C, respectivamente. Pseudomonas aeruginosa formou biofilme quando cultivada a 28 °C. Contudo foi observado somente adesão de P. aeruginosa e P. fluorescens quando incubada a 7 °C. O dicloroisocianurato de sódio foi o sanificante mais eficiente na redução de células aderidas e em biofilme de P. aeruginosa a 7 e 28 °C, respectivamente. O peróxido de hidrogênio foi o mais eficiente na redução de células aderidas de P. fluorescens a 7 °C.

The study of Bacteriocin of Pseudomonas fluorescens and Citrus limon effects against Propionibacterium acnes and Staphylococcus epidermidis in acne patients

Science.gov (United States)

Ahmed, Mais E.

2018-05-01

Research was carried out on the antibacterial effect of (Citrus limon) juice on Acnevulgaris. Samples were obtained from individuals with pimples by swabbing their faces. Natural substances that derive from plants are promising to treat disease cause Acnevulgaris, the study in vitro biological activity of the juice, as well as bacterocin cultivated and fruits was investigated on two strains of bacteria (Propionibacterium acnes, Staphylococcus epidermidis). The new antimicrobial (bacteriocin and Citrus juice) is an ongoing search. This study used juice at different concentrations at (20%, 30%, 40%, 60%, 80% and 100%). The bacteriocin produced from local P. fluorescens isolates from wound infection and majority of isolates were found to produce crude bacteriocin were (P1 and P2) in Pseudomonas agar at 37°C for 24 hrs. Crude bacteriocin and Citrus limon juice against some pathogenic skin bacteria was find to be effective juice Citrus limon aganist S. epidermidis at 100% Concentrations with a range of inhibition zone (18) mm. The isolates of P. fluorescens (P2) was positive as producer of bacteriocin with a wide inhibition growth against gram positive pathogenic bacteria with a range between (10-12) mm.

Effect of charged particle flux on Bacillus mesentericus and Pseudomonas fluorescens cultures

International Nuclear Information System (INIS)

Ostapenkov, A.M.; Kaptereva, Yu.V.; Merinov, N.S.; Lavrova, V.L.

1979-01-01

Studied was the effect of a strong electric field and charged particle (aerions) flow on Bac. mesentericus and Ps. fluorescens cultures causing the spoiling of foodstuffs and food raw materials. It has been found, that under the effects of the electric field and positive or negative ions reduced is the Bac. mesentericus and Ps. fluorescens viability, cultivated on a solid nutrient medium; the effect of the electric field only does not affect the Bac. mesentericus viability

Interaction between the Bacterium Pseudomonas fluorescens strain CHA0, its genetic derivatives and vermiculite: Effects on chemical, mineralogical and mechanical properties of vermiculite

Science.gov (United States)

Mueller, Barbara

2016-04-01

Using bacteria of the strain Pseudomonas fluorescens wild type CHA0 and its genetic derivative strains CHA77, CHA89, CHA400, CHA631 and CHA661 (which differ in one gene only) the changes in chemical, mineralogical and rheological properties of the clay mineral vermiculite affected by microbial activity were studied in order to test whether the individually different production of metabolites by the genetically engineered strains may alter the clay mineral vermiculite in distinct ways. With the novel strategy of working with living wild type bacteria, their genetic derivatives and clay, the following properties of the mineral altered by the various strains of Pseudomonas fluorescens were determined: grain size, X-Ray diffraction pattern, intercrystalline swelling with glycerol, layer charge, CEC, BET surface and uptake of trace elements. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was used to determine the changes in major, minor and trace elements of the clay vermiculite affected by microbial activity. Among all analyzed trace elements, Fe, Mn and Cu are the most interesting. Fe and Mn are taken up from the clay mineral by all bacterial strains whereas Cu is only removed from vermiculite by strains CHA0, CHA77, CHA400 and CHA661. The latter mentioned strains all produce the antibiotics 2,4-diacetylphloroglucinol and monoacetylphloroglucinol which can complex Cu efficiently. Therefore the alteration of only one gene of the bacteria is causing significant effects on the clay mineral.

Safety of spray-dried powder formulated Pseudomonas fluorescens strain CL145A exposure to subadult/adult unionid mussels during simulated open-water treatments

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Waller, Diane L.; Wise, Jeremy K.; Mayer, Denise A.; Aloisi, Douglas B.

2015-01-01

The exposure effects of a commercially prepared spray dried powder (SDP) formulation ofPseudomonas fluorescens (strain CL145A) on the survival of seven species of unionid mussels endemic to the Great Lakes and Mississippi River basins was evaluated in this study. The study exposures were completed within replicated 350-liter test tanks contained within a mobile bioassay laboratory sited on the shores of the Black River near La Crosse, Wisconsin. The test tanks were supplied with flowing, filtered river water which was interrupted during the exposure period.

Genetic responses induced in olive roots upon colonization by the biocontrol endophytic bacterium Pseudomonas fluorescens PICF7.

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Elisabetta Schilirò

Full Text Available Knowledge on the genetic basis underlying interactions between beneficial bacteria and woody plants is still very limited, and totally absent in the case of olive. We aimed to elucidate genetic responses taking place during the colonization of olive roots by the native endophyte Pseudomonas fluorescens PICF7, an effective biocontrol agent against Verticillium wilt of olive. Roots of olive plants grown under non-gnotobiotic conditions were collected at different time points after PICF7 inoculation. A Suppression Subtractive Hybridization cDNA library enriched in induced genes was generated. Quantitative real time PCR (qRT-PCR analysis validated the induction of selected olive genes. Computational analysis of 445 olive ESTs showed that plant defence and response to different stresses represented nearly 45% of genes induced in PICF7-colonized olive roots. Moreover, quantitative real-time PCR (qRT-PCR analysis confirmed induction of lipoxygenase, phenylpropanoid, terpenoids and plant hormones biosynthesis transcripts. Different classes of transcription factors (i.e., bHLH, WRKYs, GRAS1 were also induced. This work highlights for the first time the ability of an endophytic Pseudomonas spp. strain to mount a wide array of defence responses in an economically-relevant woody crop such as olive, helping to explain its biocontrol activity.

The periplasmic transaminase PtaA of Pseudomonas fluorescens converts the glutamic acid residue at the pyoverdine fluorophore to α-ketoglutaric acid.

Science.gov (United States)

Ringel, Michael T; Dräger, Gerald; Brüser, Thomas

2017-11-10

The periplasmic conversion of ferribactin to pyoverdine is essential for siderophore biogenesis in fluorescent pseudomonads, such as pathogenic Pseudomonas aeruginosa or plant growth-promoting Pseudomonas fluorescens The non-ribosomal peptide ferribactin undergoes cyclizations and oxidations that result in the fluorophore, and a strictly conserved fluorophore-bound glutamic acid residue is converted to a range of variants, including succinamide, succinic acid, and α-ketoglutaric acid residues. We recently discovered that the pyridoxal phosphate-containing enzyme PvdN is responsible for the generation of the succinamide, which can be hydrolyzed to succinic acid. Based on this, a distinct unknown enzyme was postulated to be responsible for the conversion of the glutamic acid to α-ketoglutaric acid. Here we report the identification and characterization of this enzyme in P. fluorescens strain A506. In silico analyses indicated a periplasmic transaminase in fluorescent pseudomonads and other proteobacteria that we termed PtaA for " p eriplasmic t ransaminase A " An in-frame-deleted ptaA mutant selectively lacked the α-ketoglutaric acid form of pyoverdine, and recombinant PtaA complemented this phenotype. The ptaA / pvdN double mutant produced exclusively the glutamic acid form of pyoverdine. PtaA is homodimeric and contains a pyridoxal phosphate cofactor. Mutation of the active-site lysine abolished PtaA activity and affected folding as well as Tat-dependent transport of the enzyme. In pseudomonads, the occurrence of ptaA correlates with the occurrence of α-ketoglutaric acid forms of pyoverdines. As this enzyme is not restricted to pyoverdine-producing bacteria, its catalysis of periplasmic transaminations is most likely a general tool for specific biosynthetic pathways. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

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

Science.gov (United States)

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

2015-12-01

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

Bacterial attack on phenolic ethers. Purification and characterization of the components of the meta O-dealkylase of Pseudomonas fluorescens Tp.

Science.gov (United States)

Pietrowski, R A; Cartwright, N J

1977-01-01

The meta O-dealkylase of Pseudomonas fluorescens Tp has been resolved into two protein components, neither of which is a cytochrome. The substrate binding terminal oxidase has been purified and shown to be a non-haem iron protein of approximate molecular weight 118,000, consisting of two seemingly identical subunits, each of molecular weight 55,000. Binding of substrate by the terminal oxidase has been established by difference spectroscopy. The amino acid composition of the protein has also been determined. The NADH-dependent reductase of the system has been partly purified and appears to have a molecular weight of 80,000. The similarity between this and other bacterial O-dealkylases is discussed.

Mining Genomes of Biological Control Strains of Pseudomonas spp.: Unexpected Gems and Tailings

Science.gov (United States)

The biocontrol bacterium Pseudomonas fluorescens Pf-5 suppresses numerous soilborne plant diseases and produces an array of structurally-characterized secondary metabolites that are toxic to plant pathogenic bacteria, fungi and Oomycetes. Biosynthetic gene clusters for these metabolites compose nea...

Regulation of Soluble Phosphate on the Ability of Phytate Mineralization and β-Propeller Phytase Gene Expression of Pseudomonas fluorescens JZ-DZ1, a Phytate-Mineralizing Rhizobacterium.

Science.gov (United States)

Shen, Lan; Wu, Xiao-Qin; Zeng, Qing-Wei; Liu, Hong-Bin

2016-12-01

Phytate-mineralizing rhizobacteria (PMR) play an important role in providing phosphorus for the sustainable plant growth. It is important to investigate the ability of PMR to produce phytase under different phosphate levels for its application. The effects of different concentrations of soluble phosphate on the ability of phytate mineralization of Pseudomonas fluorescens JZ-DZ1, a phytate-mineralizing rhizobacterium, were investigated in both solid and liquid media. The results on solid media showed that halo zone width gradually reduced with concentrations of soluble phosphate increasing from 0.05 to 20 mM, indicating the reduction of the ability of phytate mineralization. The results were consistent with the quantitative detection of phytase activity from the overall trend. An 1866-bp β-propeller phytase (BPP) gene (phyPf) was cloned from the strain, and the deduced amino acid sequence of phyPf shared 98 % of identity with a known BPP from Pseudomonas sp. BS10-3 (AJF36073.1). The results of relative real-time quantitative PCR assay showed that the expression of phyPf was induced by a low concentration (0.1 mM) of soluble phosphate, suggesting that BPP secretion was regulated by gene phyPf. The BPP-harboring bacterium P. fluorescens JZ-DZ1 with low phosphate-inducible ability of phytate mineralization could be potentially applied to promote phosphorus uptake for plants in the future.

Mycorrhization between Cistus ladanifer L. and Boletus edulis Bull is enhanced by the mycorrhiza helper bacteria Pseudomonas fluorescens Migula.

Science.gov (United States)

Mediavilla, Olaya; Olaizola, Jaime; Santos-del-Blanco, Luis; Oria-de-Rueda, Juan Andrés; Martín-Pinto, Pablo

2016-02-01

Boletus edulis Bull. is one of the most economically and gastronomically valuable fungi worldwide. Sporocarp production normally occurs when symbiotically associated with a number of tree species in stands over 40 years old, but it has also been reported in 3-year-old Cistus ladanifer L. shrubs. Efforts toward the domestication of B. edulis have thus focused on successfully generating C. ladanifer seedlings associated with B. edulis under controlled conditions. Microorganisms have an important role mediating mycorrhizal symbiosis, such as some bacteria species which enhance mycorrhiza formation (mycorrhiza helper bacteria). Thus, in this study, we explored the effect that mycorrhiza helper bacteria have on the efficiency and intensity of the ectomycorrhizal symbiosis between C. ladanifer and B. edulis. The aim of this work was to optimize an in vitro protocol for the mycorrhizal synthesis of B. edulis with C. ladanifer by testing the effects of fungal culture time and coinoculation with the helper bacteria Pseudomonas fluorescens Migula. The results confirmed successful mycorrhizal synthesis between C. ladanifer and B. edulis. Coinoculation of B. edulis with P. fluorescens doubled within-plant mycorrhization levels although it did not result in an increased number of seedlings colonized with B. edulis mycorrhizae. B. edulis mycelium culture time also increased mycorrhization levels but not the presence of mycorrhizae. These findings bring us closer to controlled B. edulis sporocarp production in plantations.

Exploiting genotypic diversity of 2,4-diacetylphloroglucinol-producing Pseudomonas spp.: characterization of superior root-colonizing P. fluorescens strain Q8r1-96.

Science.gov (United States)

Raaijmakers, J M; Weller, D M

2001-06-01

The genotypic diversity that occurs in natural populations of antagonistic microorganisms provides an enormous resource for improving biological control of plant diseases. In this study, we determined the diversity of indigenous 2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas spp. occurring on roots of wheat grown in a soil naturally suppressive to take-all disease of wheat. Among 101 isolates, 16 different groups were identified by random amplified polymorphic DNA (RAPD) analysis. One RAPD group made up 50% of the total population of DAPG-producing Pseudomonas spp. Both short- and long-term studies indicated that this dominant genotype, exemplified by P. fluorescens Q8r1-96, is highly adapted to the wheat rhizosphere. Q8r1-96 requires a much lower dose (only 10 to 100 CFU seed(-1) or soil(-1)) to establish high rhizosphere population densities (10(7) CFU g of root(-1)) than Q2-87 and 1M1-96, two genotypically different, DAPG-producing P. fluorescens strains. Q8r1-96 maintained a rhizosphere population density of approximately 10(5) CFU g of root(-1) after eight successive growth cycles of wheat in three different, raw virgin soils, whereas populations of Q2-87 and 1M1-96 dropped relatively quickly after five cycles and were not detectable after seven cycles. In short-term studies, strains Q8r1-96, Q2-87, and 1M1-96 did not differ in their ability to suppress take-all. After eight successive growth cycles, however, Q8r1-96 still provided control of take-all to the same level as obtained in the take-all suppressive soil, whereas Q2-87 and 1M1-96 gave no control anymore. Biochemical analyses indicated that the superior rhizosphere competence of Q8r1-96 is not related to in situ DAPG production levels. We postulate that certain rhizobacterial genotypes have evolved a preference for colonization of specific crops. By exploiting diversity of antagonistic rhizobacteria that share a common trait, biological control can be improved significantly.

PENGARUH APLIKASI PSEUDOMONAS FLUORESCENS P60 TERHADAP MUTU PATOLOGIS, MUTU FISIOLOGIS, DAN PERTUMBUHAN BIBIT PADI IR 64

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Lisa Navitasari

2014-08-01

Full Text Available Effect of Pseudomonas fluorescens P60 on pathological and physiological quality and growth of rice IR 64  seedlings. The research objectives were (1 detection and identification of seed-borne pathogens of IR 64 rice, (2 testing Pseudomonas fluorescents P60 in inhibiting the in vitro growth of seed-borne pathogens colonies, (3 testing P. fluorescents P60 for pathological and physiological seed quality, and (4 testing P. fluorescents P60 on the growth of seedlings in the greenhouse. The results showed that some seed-borne pathogens can be found both on farmers’ IR 64 rice and factory’s; they were Aspergillus flavus, Alternaria padwickii, Pseudomonas glumae, and P. syringae. Application of P. flourescens P60 was able to inhibit the in vitrogrowth of colonies of all seed-borne pathogens, except P. syringae.  Related to pathological quality, the effect of P. flourescens P60 on percentage of seed-borne pathogens attack did not significantly different from that of benomil but smaller than distilled water. On the physiological quality of seeds, treatment of P. flourescens P60 has the same effect with benomil and distilled water, with  germination rate was more than 80%. In the greenhouse study,treatment of seed immersion time  in P. flourescens P60 suspension showed that the effect of immersion time as long as15 minutes and 25 minutes on  seedling height, root length, and seedling dry weightdid not significantly different. were. However, 25 minutes immersion time resulted in fresh seedling weight and root dry weight higher than that of 15 minutes immersion time.

Effects of high intensity pulsed electric field and thermal treatments on a lipase from Pseudomonas fluorescens.

Science.gov (United States)

Bendicho, S; Estela, C; Giner, J; Barbosa-Cánovas, G V; Martin, O

2002-01-01

Milk and dairy products may contain microorganisms capable of secreting lipases that cause sensory defects and technological problems in the dairy industry. In this study, the effects of thermal and high-intensity pulsed electric field (HIPEF) treatments on an extracellular lipase from Pseudomonas fluorescens, suspended in a simulated skim milk ultrafiltrate (SMUF) have been evaluated. Heat treatments applied were up to 30 min from 50 to 90 degrees C. HIPEF treatments were carried out using pilot plant facilities in a batch or continuous flow mode, where treatment chambers consisted of parallel and coaxial configuration, respectively. Samples were subjected to up to 80 pulses at electric field intensities ranging from 16.4 to 37.3 kV/cm. This resulted in a lipase that was quite resistant to heat and also to HIPEF. High (75 degrees C-15 s) and low pasteurization treatments (63 degrees C-30 min) led to inactivations of 5 and 20%, respectively. Using the batch-mode HIPEF equipment, a 62.1% maximum activity depletion was achieved after 80 pulses at 27.4 kV/cm. However, when HIPEF treatments were applied in the continuous flow mode, an inactivation rate of just 13% was achieved, after applying 80 pulses at 37.3 kV/cm and 3.5 Hz. The results of both heat and HIPEF treatments on enzyme inactivation were adjusted with good agreement to a first-order kinetic model (R2 > 62.3%).

Methylobacterium sp. resides in unculturable state in potato tissues in vitro and becomes culturable after induction by Pseudomonas fluorescens IMGB163.

Science.gov (United States)

Podolich, O; Laschevskyy, V; Ovcharenko, L; Kozyrovska, N; Pirttilä, A M

2009-03-01

To induce growth of endophytic bacteria residing in an unculturable state in tissues of in vitro-grown potato plantlets. To isolate and identify the induced bacteria and to localize the strains in tissues of in vitro-grown potato plantlets. The inoculation of in vitro-grown potato plants with Pseudomonas fluorescens IMBG163 led to induction of another bacterium, a pink-pigmented facultative methylotroph that was identified as Methylobacterium sp. using phylogenetic 16S rDNA approach. Two molecular methods were used for localizing methylobacteria in potato plantlets: PCR and in situ hybridization (ISH/FISH). A PCR product specific for the Methylobacterium genus was found in DNA isolated from the surface-sterilized plantlet leaves. Presence of Methylobacterium rRNA was detected by ISH/FISH in leaves and stems of inoculated as well as axenic potato plantlets although the bacterium cannot be isolated from the axenic plants. Methylobacterium sp. resides in unculturable state within tissues of in vitro-grown potato plants and becomes culturable after inoculation with P. fluorescens IMBG163. In order to develop endophytic biofertilizers and biocontrol agents, a detailed knowledge of the life-style of endophytes is essential. To our knowledge, this is the first report on increase of the culturability of endophytes in response to inoculation by nonpathogenic bacteria.

Differential impact of some Aspergillus species on Meloidogyne javanica biocontrol by Pseudomonas fluorescens strain CHA0.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S; Khan, A

2004-01-01

The aim was to determine the influence of some Aspergillus species on the production of nematicidal agent(s) in vitro and biocontrol of Meloidogyne javanica in tomato by Pseudomonas fluorescens strains CHA0 and CHA0/pME3424. Six species of Aspergillus, isolated from the rhizosphere of certain crops, produced a variety of secondary metabolites in vitro. Culture filtrate (CF) obtained from Ps. fluorescens strain CHA0 and its2,4-diacetylphloroglucinol overproducing mutant CHA0/pME3424 grown in King's B liquid medium caused significant mortality of M. javanica juveniles in vitro. Bacterial growth medium amended with CF of A. niger enhanced nematicidal and beta-galactosidase activities of fluorescent pseudomonads while A. quadrilineatus repressed such activities. Methanol or ethyl acetate extracts of the CF of A. niger markedly optimized bacterial efficacy to cause nematode deaths while hexane extract of the fungus had no influence on the nematicidal activity of the bacterial strains. A. niger applied alone or in conjunction with the bacterial inoculants inhibited root-knot nematode galling in tomato. On the other hand, A. quadrilineatus used alone or together with CHA0 did not inhibit nematode galling but when used in combination with strain CHA0/pME3424 did reduce galling intensity. Aspergillus niger enhances the production of nematicidal compounds by Ps. fluorescensin vitro and improves biocontrol potential of the bacterial inoculants in tomato while A. quadrilineatus reduces bacterial performance to suppress root-knot nematodes. Rhizosphere harbours a variety of micro-organisms including bacteria, fungi and viruses. Aspergillus species are ubiquitous in most agricultural soils and generally produce a variety of secondary metabolites. Such metabolites synthesized by Aspergillus species may influence the production of nematicidal agents and subsequent biocontrol performance of the bacterial inoculants against plant-parasitic nematodes. This fact needs to be taken into

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.

Dicty_cDB: Contig-U10497-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available ce 9 from Patent WO0234921. ... 79 2e-13 AF511570_1( AF511570 |pid:none) Uncultured soil bacterium clone 57....000542_2092( CP000542 |pid:none) Verminephrobacter eiseniae EF01... 58 4e-07 AF511571_1( AF511571 |pid:none) Uncultured soil... Pseudomonas fluorescens Pf0-1, ... 51 7e-05 AF511572_1( AF511572 |pid:none) Uncultured soil bacterium clone

Dicty_cDB: Contig-U16219-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available CP000094 |pid:none) Pseudomonas fluorescens Pf0-1, ... 235 6e-60 AB241242_1( AB241242 |pid:none) Symbiotic p...59 CP000378_251( CP000378 |pid:none) Burkholderia cenocepacia AU 1054... 233 2e-59 AB241241_1( AB241241 |pid:none) Symbiotic...243 |pid:none) Trichomonas vaginalis strain G3 sm... 220 1e-55 AB241243_1( AB241243 |pid:none) Symbiotic pro

Efficacy of Pseudomonas fluorescens strain CL145A spray dried powder for controlling zebra mussels adhering to native unionid mussels within field enclosures

Science.gov (United States)

Luoma, James A.; Weber, Kerry L.; Severson, Todd J.; Mayer, Denise A.

2015-01-01

The efficacy of a commercially prepared spray dried powder (SDP) formulation of Pseudomonas fluorescens (strain CL145A) was evaluated for removing zebra mussels (Dreissena polymorpha) adhering to a population of unionid mussels in Lake Darling (Alexandria, Minnesota). Two groups of unionid mussels were used in the study. Unionid mussels were collected near the test area, weighed, photographed, individually tagged, and randomly allocated to one of nine test enclosures in equal proportions and then divided into two groups. The first group of unionid mussels (Group 1, n = 5 per test enclosure) were indiscriminately selected from each test enclosure and used to estimate the number of zebra mussels adhering to unionid mussels prior to exposure. The second group of unionid mussels (Group 2, n = 22 per test enclosure) were used to evaluate the efficacy of SDP for removal of adhering zebra mussels. Both Group 1 and Group 2 mussels were used to evaluate the effects of SDP exposure on unionid mussel survival.

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

Directory of Open Access Journals (Sweden)

Tatyane R. Silva

2007-03-01

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

Differentiation of isolated native of desulphurizators Pseudomonas by means of the study of the profile of fatty acids

International Nuclear Information System (INIS)

Silva Gomez, Edelberto; Morales P, Alicia Lucia; Callejas Castro Solange; Florez Sandoval Maria Cecilia; Rodriguez Wilson

2000-01-01

The content of cellular fatty acids was determined by HRGC of twelve Colombian isolated Pseudomonas aeruginosa 17,18, 19, 20, 21, 22 and 103 pseudomonas sp 23,24,25,26 and 27 with desulphurization capacity, pseudomonas aeruginosa ATCC 9027 and 10145, pseudomonas sp ATCC 39327 and pseudomonas fluorescens. Fifty-three different types of fatty acids were found, among saturated and unsaturated of lineal chain, and mainly hydroxy acids and ramified. Of these, 17 have not been described in the literature for this genus. A group of 6 acids was presented with more frequency (15:0; 16:0; 16:1; 17:1; 3-OH 16:0 and 2-OH 15:0) in more than 75% of the pseudomonas studied. The studied microorganisms are related because they share the presence of some characteristic fatty acids, that which allows assuring that they belong to same taxonomic unit. The analysis cluster developed by means of plotting in dendrograms of the qualitative and quantitative contents of the acids fatty totals showed the formation of two attaches, the I conformed by ATCC 39327 and the isolated 17 and 25, and the II by Ps. Fluorescens and the isolated one 27. The dendrogram of the hydroxy acids shows the formation of four attaches, the I attache, (isolated 17 and 20), the II A (isolated 22 and 103), the II B (isolated 27 and ps. fluorescens) and the attache III (isolated 18 and 19). In that of the ramified fatty acids the formation of a main attache is observed conformed by four sub-groups, the IA (isolated 17), the I B (isolated 18 and 24), the I C (isolated 19 and 25 and Ps. fluorescens) and I D (isolated 27). These results show that the isolated 27,25,24, 19, 18 and 17, in their order, have narrow relationship to Ps. fluorescens

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.

Endophytic Bacterium Pseudomonas fluorescens RG11 May Transform Tryptophan to Melatonin and Promote Endogenous Melatonin Levels in the Roots of Four Grape Cultivars.

Science.gov (United States)

Ma, Yaner; Jiao, Jian; Fan, Xiucai; Sun, Haisheng; Zhang, Ying; Jiang, Jianfu; Liu, Chonghuai

2016-01-01

Endophytes have been verified to synthesize melatonin in vitro and promote abiotic stress-induced production of endogenous melatonin in grape ( Vitis vinifera L.) roots. This study aimed to further characterize the biotransformation of tryptophan to melatonin in the endophytic bacterium Pseudomonas fluorescens RG11 and to investigate its capacity for enhancing endogenous melatonin levels in the roots of different grape cultivars. Using ultra performance liquid chromatography-tandem mass spectrometry combined with 15N double-labeled L -tryptophan as the precursor for melatonin, we detected isotope-labeled 5-hydroxytryptophan, serotonin, N -acetylserotonin, and melatonin, but tryptamine was not detected during the in vitro incubation of P. fluorescens RG11. Furthermore, the production capacity of these four compounds peaked during the exponential growth phase. RG11 colonization increased the endogenous levels of 5-hydroxytryptophan, N -acetylserotonin, and melatonin, but reduced those of tryptamine and serotonin, in the roots of the Red Globe grape cultivar under salt stress conditions. Quantitative real-time PCR revealed that RG11 reduced the transcription of grapevine tryptophan decarboxylase and serotonin N -acetyltransferase genes when compared to the un-inoculated control. These results correlated with decreased reactive oxygen species bursts and cell damage, which were alleviated by RG11 colonization under salt stress conditions. Additionally, RG11 promoted plant growth and enhanced the levels of endogenous melatonin in different grape cultivars. Intraspecific variation in the levels of melatonin precursors was found among four grape cultivars, and the associated root crude extracts appeared to significantly induce RG11 melatonin biosynthesis in vitro . Overall, this study provides useful information that enhances the existing knowledge of a potential melatonin synthesis pathway in rhizobacteria, and it reveals plant-rhizobacterium interactions that affect

Characterisation of the thermostable protease AprX in strains of Pseudomonas fluorescens and impact on the shelf-life of dairy products: preliminary results

Directory of Open Access Journals (Sweden)

Nadia Andrea Andreani

2016-12-01

Full Text Available Bacterial proteases are involved in food spoilage and shelf-life reduction. Among the bacterial proteases, a predominant role in spoilage of dairy products seems to be played by the thermostable metallo-protease AprX, which is produced by various strains of Pseudomonas fluorescens. Differences in AprX enzyme activity among different strains were highlighted, but the most proteolytic strains were not identified. In this study, the presence of the aprX gene was evaluated in 69 strains isolated from food matrices and 18 reference strains belonging to the P. fluorescens group, which had been previously typed by the multi locus sequence typing method. Subsequently, a subset of reference strains was inoculated in ultra-high temperature milk, and the expression of the aprX gene was evaluated at 22 and 6°C. On the same milk samples, the proteolytic activity was then evaluated through Azocasein and trinitrobenzenesulfonic acid solution assays. Finally, to assess the applicability of the former assay directly on dairy products the proteolityc activity was tested on industrial ricotta samples using the Azocasein assay. These results demonstrate the spread of aprX gene in most strains tested and the applicability of Azocasein assay to monitor the proteolytic activity in dairy products.

Characterization of the CrbS/R Two-Component System in Pseudomonas fluorescens Reveals a New Set of Genes under Its Control and a DNA Motif Required for CrbR-Mediated Transcriptional Activation

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Edgardo Sepulveda

2017-11-01

Full Text Available The CrbS/R system is a two-component signal transduction system that regulates acetate utilization in Vibrio cholerae, P. aeruginosa, and P. entomophila. CrbS is a hybrid histidine kinase that belongs to a recently identified family, in which the signaling domain is fused to an SLC5 solute symporter domain through aSTAC domain. Upon activation by CrbS, CrbR activates transcription of the acs gene, which encodes an acetyl-CoA synthase (ACS, and the actP gene, which encodes an acetate/solute symporter. In this work, we characterized the CrbS/R system in Pseudomonas fluorescens SBW25. Through the quantitative proteome analysis of different mutants, we were able to identify a new set of genes under its control, which play an important role during growth on acetate. These results led us to the identification of a conserved DNA motif in the putative promoter region of acetate-utilization genes in the Gammaproteobacteria that is essential for the CrbR-mediated transcriptional activation of genes under acetate-utilizing conditions. Finally, we took advantage of the existence of a second SLC5-containing two-component signal transduction system in P. fluorescens, CbrA/B, to demonstrate that the activation of the response regulator by the histidine kinase is not dependent on substrate transport through the SLC5 domain.

Variation of the Pseudomonas community structure on oak leaf lettuce during storage detected by culture-dependent and -independent methods.

Science.gov (United States)

Nübling, Simone; Schmidt, Herbert; Weiss, Agnes

2016-01-04

The genus Pseudomonas plays an important role in the lettuce leaf microbiota and certain species can induce spoilage. The aim of this study was to investigate the occurrence and diversity of Pseudomonas spp. on oak leaf lettuce and to follow their community shift during a six day cold storage with culture-dependent and culture-independent methods. In total, 21 analysed partial Pseudomonas 16S rRNA gene sequences matched closely (> 98.3%) to the different reference strain sequences, which were distributed among 13 different phylogenetic groups or subgroups within the genus Pseudomonas. It could be shown that all detected Pseudomonas species belonged to the P. fluorescens lineage. In the culture-dependent analysis, 73% of the isolates at day 0 and 79% of the isolates at day 6 belonged to the P. fluorescens subgroup. The second most frequent group, with 12% of the isolates, was the P. koreensis subgroup. This subgroup was only detected at day 0. In the culture-independent analysis the P. fluorescens subgroup and P. extremaustralis could not be differentiated by RFLP. Both groups were most abundant and amounted to approximately 46% at day 0 and 79% at day 6. The phytopathogenic species P. salmonii, P. viridiflava and P. marginalis increased during storage. Both approaches identified the P. fluorescens group as the main phylogenetic group. The results of the present study suggest that pseudomonads found by plating methods indeed represent the most abundant part of the Pseudomonas community on oak leaf lettuce. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Cost modeling of pseudomonoas fluorescens and pseudomonoas chlororphis biocontrol for competitive exclusion of salmonella enterica on tomatoes

Science.gov (United States)

Biocontrol measures may enhance postharvest interventions, however; published research on process-based models for biocontrol of foodborne pathogens on produce is limited. The aim of this research was to develop cost model estimates for competitive exclusion process using Pseudomonas fluorescens and...

Antibiotic and biosurfactant properties of cyclic lipopeptides produced by fluorescent Pseudomonas spp. from the sugar beet rhizosphere

DEFF Research Database (Denmark)

Nielsen, T H; Sørensen, D; Tobiasen, C

2002-01-01

Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600...... in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties...

Prokaryotic Homologs of the Eukaryotic 3-Hydroxyanthranilate 3,4-Dioxygenase and 2-Amino-3-Carboxymuconate-6-Semialdehyde Decarboxylase in the 2-Nitrobenzoate Degradation Pathway of Pseudomonas fluorescens Strain KU-7†

OpenAIRE

Muraki, Takamichi; Taki, Masami; Hasegawa, Yoshie; Iwaki, Hiroaki; Lau, Peter C. K.

2003-01-01

The 2-nitrobenzoic acid degradation pathway of Pseudomonas fluorescens strain KU-7 proceeds via a novel 3-hydroxyanthranilate intermediate. In this study, we cloned and sequenced a 19-kb DNA locus of strain KU-7 that encompasses the 3-hydroxyanthranilate meta-cleavage pathway genes. The gene cluster, designated nbaEXHJIGFCDR, is organized tightly and in the same direction. The nbaC and nbaD gene products were found to be novel homologs of the eukaryotic 3-hydroxyanthranilate 3,4-dioxygenase a...

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 ...

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...

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.

Switching Catalysis from Hydrolysis to Perhydrolysis in Pseudomonas fluorescens Esterase

Energy Technology Data Exchange (ETDEWEB)

Yin, D.; Bernhardt, P; Morley, K; Jiang, Y; Cheeseman, J; Purpero, V; Schrag, J; Kazlauskas, R

2010-01-01

Many serine hydrolases catalyze perhydrolysis, the reversible formation of peracids from carboxylic acids and hydrogen peroxide. Recently, we showed that a single amino acid substitution in the alcohol binding pocket, L29P, in Pseudomonas fluorescens (SIK WI) aryl esterase (PFE) increased the specificity constant of PFE for peracetic acid formation >100-fold [Bernhardt et al. (2005) Angew. Chem., Int. Ed. 44, 2742]. In this paper, we extend this work to address the three following questions. First, what is the molecular basis of the increase in perhydrolysis activity? We previously proposed that the L29P substitution creates a hydrogen bond between the enzyme and hydrogen peroxide in the transition state. Here we report two X-ray structures of L29P PFE that support this proposal. Both structures show a main chain carbonyl oxygen closer to the active site serine as expected. One structure further shows acetate in the active site in an orientation consistent with reaction by an acyl-enzyme mechanism. We also detected an acyl-enzyme intermediate in the hydrolysis of {var_epsilon}-caprolactone by mass spectrometry. Second, can we further increase perhydrolysis activity? We discovered that the reverse reaction, hydrolysis of peracetic acid to acetic acid and hydrogen peroxide, occurs at nearly the diffusion limited rate. Since the reverse reaction cannot increase further, neither can the forward reaction. Consistent with this prediction, two variants with additional amino acid substitutions showed 2-fold higher k{sub cat}, but K{sub m} also increased so the specificity constant, k{sub cat}/K{sub m}, remained similar. Third, how does the L29P substitution change the esterase activity? Ester hydrolysis decreased for most esters (75-fold for ethyl acetate) but not for methyl esters. In contrast, L29P PFE catalyzed hydrolysis of {var_epsilon}-caprolactone five times more efficiently than wild-type PFE. Molecular modeling suggests that moving the carbonyl group closer to the

Quantification of Pseudomonas fluorescens strains F113, CHA0 and Pf153 in the rhizosphere of maize by strain-specific real-time PCR unaffected by the variability of DNA extraction efficiency.

Science.gov (United States)

Von Felten, Andreas; Défago, Geneviève; Maurhofer, Monika

2010-05-01

Pseudomonas fluorescens strains F113 and CHA0 are well-known plant growth-promoting rhizobacteria (PGPR) often used as model strains in biocontrol experiments. To monitor their persistence in large scale field experiments, culture-independent methods are needed. In this study, a strain-specific real-time PCR quantification tool was developed based on sequence-characterized amplified regions (SCAR) for P. fluorescens strains F113, CHA0 and Pf153. Differences in DNA extraction efficiencies from rhizosphere samples were circumvented using plasmid APA9 as internal standard to normalize C(T) values after real-time amplification. The detection limits of the real-time PCR assays for all three strains were approximately 10 cells for genomic DNA and 10(4)cells/g rhizosphere for maize samples grown in different natural soils. Population sizes of the three strains in the rhizosphere of maize measured by the new real-time PCR approaches were similar to those measured by most probable number (MPN)-PCR. A persistence study of the three strains indicated that the strains persisted differently over a period of 5weeks. In conclusion the newly developed real-time PCR approach is a fast and resource efficient method for monitoring individual biocontrol strains in natural soil, which makes it an apt quantification tool for future large-scale field experiments. Copyright 2010 Elsevier B.V. All rights reserved.

Arabidopsis thaliana as a tool to identify traits involved in Verticillium dahliae biocontrol by the olive root endophyte Pseudomonas fluorescens PICF7

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M. Mercedes eMaldonado-González

2015-04-01

Full Text Available The effective management of Verticillium wilts, diseases affecting many crops and caused by some species of the soil-borne fungus Verticillium, is problematic. The use of microbial antagonists to control these pathologies fits modern sustainable agriculture criteria. Pseudomonas fluorescens PICF7 is an endophytic bacterium isolated from olive roots with demonstrated ability to control Verticillium wilt of olive caused by the highly-virulent, defoliating (D pathotype of Verticillium dahliae Kleb. However, the study of the PICF7-V.dahliae-olive tripartite interaction poses difficulties because of the inherent characteristics of woody, long-living plants. To overcome these problems we explored the use of the model plant Arabidopsis thaliana. Results obtained in this study showed that: (i olive D and non-defoliating (ND V. dahliae pathotypes produce differential disease severity in A. thaliana plants; (ii strain PICF7 is able to colonize and persist in the A. thaliana rhizosphere but is not endophytic in Arabidopsis; and (iii strain PICF7 controls Verticillium wilt (VW in Arabidopsis. Additionally, as previously observed in olive, neither swimming motility nor siderophore production by PICF7 are required for VW control in A. thaliana, whilst cysteine auxotrophy decreased the effectiveness of PICF7. Moreover, when applied to the roots PICF7 controlled Botrytis cinerea infection in the leaves of Arabidopsis, suggesting that this strain is able to induce systemic resistance. Arabidopsis thaliana is therefore a suitable alternative to olive bioassays to unravel biocontrol traits involved in biological control of V. dahliae by P. fluorescens PICF7.

Antibiotic and biosurfactant properties of cyclic lipopeptides produced by fluorescent Pseudomonas spp. from the sugar beet rhizosphere

DEFF Research Database (Denmark)

Nielsen, T.H.; Sørensen, D.; Tobiasen, C.

2002-01-01

Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600...... fluorescent Pseudomonas spp. from two different agricultural soils by using three different growth media. CLP production was observed in a large proportion of the strains (approximately 60%) inhabiting the sandy soil, compared to a low proportion (approximately 6%) in the loamy soil. Chemical structure...... in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties...

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.

Pseudomonas fluorescens JH 70-4 promotes pb stabilization and early seedling growth of sudan grass in contaminated mining site soil.

Science.gov (United States)

Shim, Jaehong; Babu, A Giridhar; Velmurugan, Palanivel; Shea, Patrick J; Oh, Byung-Taek

2014-01-01

A bacterial strain (JH 70-4) exhibiting plant growth promoting characteristics (indoleacetic acid production and 1-aminocyclopropane-1-carboxylate deaminase activity), as well as heavy metal(loid) (HM) tolerance and Pb precipitation, was isolated from HM-contaminated soil at an abandoned mine site. The bacterium was identified as Pseudomonas fluorescens based on 16S rDNA sequencing. The JH 70-4 strain induced precipitation of Pb as PbS nanoparticles, confirmed by X-ray diffraction. Solution pH, incubation time, and Pb concentration influenced removal and PbS formation. Inoculating contaminated soil with JH 70-4 decreased Pb availability; exchangeable Pb decreased while organic- and sulphide-bound Pb increased. The toxicity characteristic leaching procedure showed a 65% decrease in Pb in leachate 60 d after inoculating soil with JH 70-4. Shoot and root lengths of Sudan grass grown in the inoculated soil were greater than in the uninoculated soil. Findings suggest that microbial Pb fixation is a viable strategy for remediating soil and promoting plant growth for phytostabilization of contaminated sites.

Inhibition of food-related bacteria by antibacterial substances produced by Pseudomonas sp. strains isolated from pasteurized milk

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Ana Beatriz Ferreira Rangel

2013-12-01

Full Text Available In this work, the production of antimicrobial substances by strains of Pseudomonas sp. isolated from pasteurized milk and their potential action against food-related bacteria were investigated. Samples of pasteurized milk were purchased from arbitrarily chosen commercial establishments in the city of Rio de Janeiro, Brazil. Of the four samples analyzed, three presented several typical colonies of Pseudomonas. About 100 colonies were chosen and subjected to biochemical tests for confirmation of their identity. Eighteen strains of the Pseudomonas genus were identified and submitted to tests for the production of antimicrobial substances. Twelve strains (66.7% were identified as Pseudomonas fluorescens, four (22.2% as P. aeruginosa, one (5.5% as P. mendocina and one (5.5% as P. pseudoalcaligenes. Only two P. fluorescens strains were unable to produce any antimicrobial substance against any of the indicator strains tested. Most of the strains presented a broad spectrum of action, inhibiting reference and food-related strains such as Proteus vulgaris, Proteus mirabilis, Hafnia alvei, Yersinia enterocolitica, Escherichia coli and Salmonella typhi. Five antimicrobial substance-producing strains, which presented the broadest spectrum of action, were also tested against Staphylococcus aureus reference strains and 26 Staphylococcus sp. strains isolated from foods, some of which were resistant to antibiotics. The producer strains 8.1 and 8.3, both P. aeruginosa, were able to inhibit all the staphylococcal strains tested. The antimicrobial substances produced by strains 8.1 and 8.3 did not seem to be typical bacteriocins, since they were resistant to the three proteolytic enzymes tested. Experiments involving the characterization of these substances are being carried out in order to evaluate their biotechnological application.

Anti-pseudomona and Anti-bacilli Activity of Some Medicinal Plants of Iran

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Gholam Hosein Shahidi Bonjar

2003-10-01

Full Text Available The use of plants in treatment of burns, dermatophytes, and infectious diseases is common in traditional medicine of Iran. Based on ethno pharmacological and taxonomic information, antibacterial activities of methanol extracts of some medicinal plants of Iran were determined by In Vitro bioassays using agar diffusion-method against standard strains of Pseudomonas aeruginosa, P. fluorescens, Bacillus subtilis, B. cereus and B. pumilis at 20 mg/ml. From 180 plant species of 72 families, 78 species (43.3% in 42 families (58.3% showed antibacterial activities against B. cereus (88.4%, B. subtilis (39.7%, B. pumilis (37.1%, P. fluorescens (37.1% and P. aeruginos (10.2%. The most active plant families were Apiaceae, Compositae and Labiatae with 9, 8 and 7 active plant species respectively. Minimum inhibitory concentrations (MIC of the active plants were determined using two fold serial dilutions. Most active plant against Bacilli was Myrtus communis L. with MIC of 1.87 mg/ml. For Pseudomonas species, Dianthus caryophyllus L. and Terminalia chebula (Gaertner Retz. were more active with the MIC of 0.46 mg/ml for P. fluorescens and of 1.87 mg/ml for P. aeruginosa respectively.

Kinetics of biofilm formation and desiccation survival of Listeria monocytogenes in single and dual species biofilms with Pseudomonas fluorescens, Serratia proteamaculans or Shewanella baltica on food-grade stainless steel surfaces.

Science.gov (United States)

Daneshvar Alavi, Hessam Edin; Truelstrup Hansen, Lisbeth

2013-01-01

This study investigated the dynamics of static biofilm formation (100% RH, 15 °C, 48-72 h) and desiccation survival (43% RH, 15 °C, 21 days) of Listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, Pseudomonas fluorescens, Serratia proteamaculans and Shewanella baltica, on the surface of food grade stainless steel. The Gram-negative bacteria reduced the maximum biofilm population of L. monocytogenes in dual species biofilms and increased its inactivation during desiccation. However, due to the higher desiccation resistance of Listeria relative to P. fluorescens and S. baltica, the pathogen survived in greater final numbers. In contrast, S. proteamaculans outcompeted the pathogen during the biofilm formation and exhibited similar desiccation survival, causing the N21 days of Serratia to be ca 3 Log10(CFU cm(-2)) greater than that of Listeria in the dual species biofilm. Microscopy revealed biofilm morphologies with variable amounts of exopolymeric substance and the presence of separate microcolonies. Under these simulated food plant conditions, the fate of L. monocytogenes during formation of mixed biofilms and desiccation depended on the implicit characteristics of the co-cultured bacterium.

Glyphosate-Induced Specific and Widespread Perturbations in the Metabolome of Soil Pseudomonas Species

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Ludmilla Aristilde

2017-06-01

Full Text Available Previous studies have reported adverse effects of glyphosate on crop-beneficial soil bacterial species, including several soil Pseudomonas species. Of particular interest is the elucidation of the metabolic consequences of glyphosate toxicity in these species. Here we investigated the growth and metabolic responses of soil Pseudomonas species grown on succinate, a common root exudate, and glyphosate at different concentrations. We conducted our experiments with one agricultural soil isolate, P. fluorescens RA12, and three model species, P. putida KT2440, P. putida S12, and P. protegens Pf-5. Our results demonstrated both species- and strain-dependent growth responses to glyphosate. Following exposure to a range of glyphosate concentrations (up to 5 mM, the growth rate of both P. protegens Pf-5 and P. fluorescens RA12 remained unchanged whereas the two P. putida strains exhibited from 0 to 100% growth inhibition. We employed a 13C-assisted metabolomics approach using liquid chromatography-mass spectrometry to monitor disruptions in metabolic homeostasis and fluxes. Profiling of the whole-cell metabolome captured deviations in metabolite levels involved in the tricarboxylic acid cycle, ribonucleotide biosynthesis, and protein biosynthesis. Altered metabolite levels specifically in the biosynthetic pathway of aromatic amino acids (AAs, the target of toxicity for glyphosate in plants, implied the same toxicity target in the soil bacterium. Kinetic flux experiments with 13C-labeled succinate revealed that biosynthetic fluxes of the aromatic AAs were not inhibited in P. fluorescens Pf-5 in the presence of low and high glyphosate doses but these fluxes were inhibited by up to 60% in P. putida KT2440, even at sub-lethal glyphosate exposure. Notably, the greatest inhibition was found for the aromatic AA tryptophan, an important precursor to secondary metabolites. When the growth medium was supplemented with aromatic AAs, P. putida S12 exposed to a lethal

Comparative genomic analysis of four representative plant growth-promoting rhizobacteria in Pseudomonas

Science.gov (United States)

2013-01-01

Background Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are non-pathogenic biocontrol agents, and some Pseudomonas aeruginosa and Pseudomonas stutzeri strains are PGPR. P. chlororaphis GP72 is a plant growth-promoting rhizobacterium with a fully sequenced genome. We conducted a genomic analysis comparing GP72 with three other pseudomonad PGPR: P. fluorescens Pf-5, P. aeruginosa M18, and the nitrogen-fixing strain P. stutzeri A1501. Our aim was to identify the similarities and differences among these strains using a comparative genomic approach to clarify the mechanisms of plant growth-promoting activity. Results The genome sizes of GP72, Pf-5, M18, and A1501 ranged from 4.6 to 7.1 M, and the number of protein-coding genes varied among the four species. Clusters of Orthologous Groups (COGs) analysis assigned functions to predicted proteins. The COGs distributions were similar among the four species. However, the percentage of genes encoding transposases and their inactivated derivatives (COG L) was 1.33% of the total genes with COGs classifications in A1501, 0.21% in GP72, 0.02% in Pf-5, and 0.11% in M18. A phylogenetic analysis indicated that GP72 and Pf-5 were the most closely related strains, consistent with the genome alignment results. Comparisons of predicted coding sequences (CDSs) between GP72 and Pf-5 revealed 3544 conserved genes. There were fewer conserved genes when GP72 CDSs were compared with those of A1501 and M18. Comparisons among the four Pseudomonas species revealed 603 conserved genes in GP72, illustrating common plant growth-promoting traits shared among these PGPR. Conserved genes were related to catabolism, transport of plant-derived compounds, stress resistance, and rhizosphere colonization. Some strain-specific CDSs were related to different kinds of biocontrol activities or plant growth promotion. The GP72 genome

Photocatalytic disinfection of spoilage bacteria Pseudomonas fluorescens and Macrococcus caseolyticus by nano-TiO2

Science.gov (United States)

Photocatalytic disinfection of spoilage bacteria gram-negative (G-) P. fluorescens and gram-positive (G+) M. caseolyticus by nano-TiO2 under different experimental conditions and the disinfection mechanism were investigated. The experimental conditions included the initial bacterial populations, nan...

Application of Endophytic Pseudomonas fluorescens and a Bacterial Consortium to Brassica napus Can Increase Plant Height and Biomass under Greenhouse and Field Conditions

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Richard D. Lally

2017-12-01

Full Text Available Plant associated bacteria with plant growth promotion (PGP properties have been proposed for use as environmentally friendly biofertilizers for sustainable agriculture; however, analysis of their efficacy in the field is often limited. In this study, greenhouse and field trials were carried out using individual endophytic Pseudomonas fluorescens strains, the well characterized rhizospheric P. fluorescens F113 and an endophytic microbial consortium of 10 different strains. These bacteria had been previously characterized with respect to their PGP properties in vitro and had been shown to harbor a range of traits associated with PGP including siderophore production, 1-aminocyclopropane-1-carboxylic acid (ACC deaminase activity, and inorganic phosphate solubilization. In greenhouse experiments individual strains tagged with gfp and Kmr were applied to Brassica napus as a seed coat and were shown to effectively colonize the rhizosphere and root of B. napus and in addition they demonstrated a significant increase in plant biomass compared with the non-inoculated control. In the field experiment, the bacteria (individual and consortium were spray inoculated to winter oilseed rape B. napus var. Compass which was grown under standard North Western European agronomic conditions. Analysis of the data provides evidence that the application of the live bacterial biofertilizers can enhance aspects of crop development in B. napus at field scale. The field data demonstrated statistically significant increases in crop height, stem/leaf, and pod biomass, particularly, in the case of the consortium inoculated treatment. However, although seed and oil yield were increased in the field in response to inoculation, these data were not statistically significant under the experimental conditions tested. Future field trials will investigate the effectiveness of the inoculants under different agronomic conditions.

NCBI nr-aa BLAST: CBRC-PTRO-27-0010 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-PTRO-27-0010 ref|YP_258895.1| DNA internalization-related competence protein C...omEC/Rec2 [Pseudomonas fluorescens Pf-5] gb|AAY91064.1| DNA internalization-related competence protein ComEC/Rec2 [Pseudomonas fluorescens Pf-5] YP_258895.1 7e-06 30% ...

IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

International Nuclear Information System (INIS)

Daniel Molloy

2003-01-01

Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter

IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

Energy Technology Data Exchange (ETDEWEB)

Daniel Molloy

2003-08-04

Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter.

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

Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens

DEFF Research Database (Denmark)

Nayaka, Siddaiah Chandra; Shankar, Akarere C. Udaya; Reddy, Munagala S.

2009-01-01

Abstract BACKGROUND: Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have...... disease and fumonisin accumulation, and also to study the capacity to promote growth and yield of maize. In vitro assays were conducted to test the efficacy of P. fluorescens as a seed treatment on seed germination, seedling vigour and also the incidence of F. verticillioides in different maize cultivars....... verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. CONCLUSION: The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize...

Lipid transfer proteins and protease inhibitors as key factors in the priming of barley responses to Fusarium head blight disease by a biocontrol strain of Pseudomonas fluorescens.

Science.gov (United States)

Petti, Carloalberto; Khan, Mojibur; Doohan, Fiona

2010-11-01

Strains of non-pathogenic pseudomonad bacteria, can elicit host defence responses against pathogenic microorganisms. Pseudomonas fluorescens strain MKB158 can protect cereals from pathogenesis by Fusarium fungi, including Fusarium head blight which is an economically important disease due to its association with both yield loss and mycotoxin contamination of grain. Using the 22 K barley Affymetrix chip, trancriptome studies were undertaken to determine the local effect of P. fluorescens strain MKB158 on the transcriptome of barley head tissue, and to discriminate transcripts primed by the bacterium to respond to challenge by Fusarium culmorum, a causal agent of the economically important Fusarium head blight disease of cereals. The bacterium significantly affected the accumulation of 1203 transcripts and primed 74 to positively, and 14 to negatively, respond to the pathogen (P = 0.05). This is the first study to give insights into bacterium priming in the Triticeae tribe of grasses and associated transcripts were classified into 13 functional classes, associated with diverse functions, including detoxification, cell wall biosynthesis and the amplification of host defence responses. In silico analysis of Arabidopsis homologs of bacterium-primed barley genes indicated that, as is the case in dicots, jasmonic acid plays a role in pseudomonad priming of host responses. Additionally, the transcriptome studies described herein also reveal new insights into bacterium-mediated priming of host defences against necrotrophs, including the positive effects on grain filling, lignin deposition, oxidative stress responses, and the inhibition of protease inhibitors and proteins that play a key role in programmed cell death.

Response to gaseous NO2 air pollutant of P. fluorescens airborne strain MFAF76a and clinical strain MFN1032

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Tatiana eKondakova

2016-03-01

Full Text Available Human exposure to nitrogen dioxide (NO2, an air pollutant of increasing interest in biology, results in several toxic effects to human health and also to the air microbiota. The aim of this study was to investigate the bacterial response to gaseous NO2. Two Pseudomonas fluorescens strains, namely the airborne strain MFAF76a and the clinical strain MFN1032 were exposed to 0.1, 5 or 45 ppm concentrations of NO2, and their effects on bacteria were evaluated in terms of motility, biofilm formation, antibiotic resistance, as well as expression of several chosen target genes. While 0.1 and 5 ppm of NO2 did not lead to any detectable modification in the studied phenotypes of the two bacteria, several alterations were observed when the bacteria were exposed to 45 ppm of gaseous NO2. We thus chose to focus on this high concentration. NO2-exposed P. fluorescens strains showed reduced swimming motility, and decreased swarming in case of the strain MFN1032. Biofilm formed by NO2-treated airborne strain MFAF76a showed increased maximum thickness compared to non-treated cells, while NO2 had no apparent effect on the clinical MFN1032 biofilm structure. It is well known that biofilm and motility are inversely regulated by intracellular c-di-GMP level. The c-di-GMP level was however not affected in response to NO2 treatment. Finally, NO2-exposed P. fluorescens strains were found to be more resistant to ciprofloxacin and chloramphenicol. Accordingly, the resistance nodulation cell division (RND MexEF-OprN efflux pump encoding genes were highly upregulated in the two P. fluorescens strains. Noticeably, similar phenotypes had been previously observed following a NO treatment. Interestingly, an hmp-homologue gene in P. fluorescens strains MFAF76a and MFN1032 encodes a NO dioxygenase that is involved in NO detoxification into nitrites. Its expression was upregulated in response to NO2, suggesting a possible common pathway between NO and NO2 detoxification. Taken

INOCULACIÓN AL SUELO CON Pseudomonas fluorescens, Azospirillum oryzae, Bacillus subtilis Y MICROORGANISMOS DE MONTAÑA (MM Y SU EFECTO SOBRE UN SISTEMA DE ROTACIÓN SOYA-TOMATE BAJO CONDICIONES DE INVERNADERO

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Leida Castro Barquero

2015-01-01

Full Text Available Se evaluó un sistema de rotación soya- tomate, con incorporación de biomasa verde y aplicación de inóculos microbianos individuales y en mezcla sobre el crecimiento de las plantas y propiedades edáficas; para ello se evaluaron en invernadero por 24 meses los siguientes 9 trata - mientos: solo tomate (T; rotación tomate-soya (TS; rotación tomate-soya con inoculaciones individuales de Azospirillum oryzae (A; de Pseudomonas fluorescens (P; de Bacillus sub - tilis (B; de microorganismos de montaña (MM; y las inoculaciones en mezcla de B. subtilis y P. fluorescens (BP; de B. subtilis, P. fluorescens y A. oryzae ( BPA; d e B. subtilis , P. fluorescens , Azospirillum sp. y MM (BPAMM. Se evalua - ron las variables físicas: densidad aparente y de partículas; conductividad hidráulica; poros totales; estabilidad de agregados; resistencia a la penetración (RP; las variables químicas: pH; conductividad eléctrica; contenido de N y C; relación C/N; contenido de nutrientes en suelos y foliares; las variables biológicas: respiración de suelos, unidades formadoras de colonias de hongos, bacterias y actinomicetos y el peso fres - co y seco foliar. Las variables físicas no fueron afectadas por los tratamientos, con excepción de RP, que fue mayor en el tratamiento T. Las varia - bles biológicas y químicas fueron sensibles a los tratamientos, con valores significativamente más altos en presencia de MM. Destaca el incremento del P en solución de suelo en tratamientos a los que se adicionó MM: pasó de 6 a 20 mg.l -1 ; esta condición se reflejó además en la cantidad de P en el tejido foliar al final del ensayo. Se determi - nó que el pH, CE y la respiración del suelo fueron afectados por la interacción entre los tratamientos aplicados y el tiempo transcurrido; los mayores valores se obtuvieron al final del ensayo y en los tratamientos con MM.

Biodegradation of phenol, salicylic acid, benzenesulfonic acid, and iomeprol by Pseudomonas fluorescens in the capillary fringe.

Science.gov (United States)

Hack, Norman; Reinwand, Christian; Abbt-Braun, Gudrun; Horn, Harald; Frimmel, Fritz H

2015-12-01

Mass transfer and biological transformation phenomena in the capillary fringe were studied using phenol, salicylic acid, benzenesulfonic acid, and the iodinated X-ray contrast agent iomeprol as model organic compounds and the microorganism strain Pseudomonas fluorescens. Three experimental approaches were used: Batch experiments (uniform water saturation and transport by diffusion), in static columns (with a gradient of water saturation and advective transport in the capillaries) and in a flow-through cell (with a gradient of water saturation and transport by horizontal and vertical flow: 2-dimension flow-through microcosm). The reactors employed for the experiments were filled with quartz sand of defined particle size distribution (dp=200...600 μm, porosity ε=0.42). Batch experiments showed that phenol and salicylic acid have a high, whereas benzenesulfonic acid and iomeprol have a quite low potential for biodegradation under aerobic conditions and in a matrix nearly close to water saturation. Batch experiments under anoxic conditions with nitrate as electron acceptor revealed that the biodegradation of the model compounds was lower than under aerobic conditions. Nevertheless, the experiments showed that the moisture content was also responsible for an optimized transport in the liquid phase of a porous medium. Biodegradation in the capillary fringe was found to be influenced by both the moisture content and availability of the dissolved substrate, as seen in static column experiments. The gas-liquid mass transfer of oxygen also played an important role for the biological activity. In static column experiments under aerobic conditions, the highest biodegradation was found in the capillary fringe (e.g. βt/β0 (phenol)=0 after t=6 d) relative to the zone below the water table and unsaturated zone. The highest biodegradation occurred in the flow-through cell experiment where the height of the capillary fringe was largest. Copyright © 2015 Elsevier B.V. All rights

Biosynthesis of the antimicrobial cyclic lipopeptides nunamycin and nunapeptin by Pseudomonas fluorescens strain In5 is regulated by the LuxR-type transcriptional regulator NunF

DEFF Research Database (Denmark)

Hennessy, Rosanna Catherine; Phippen, Christopher; Nielsen, Kristian Fog

2017-01-01

-producing pseudomonads except for the border regions where putative LuxR-type regulators are located. This study focuses on understanding the regulatory role of the LuxR-type-encoding gene nunF in CLP production of P. fluorescens In5. Functional analysis of nunF coupled with liquid chromatography-high-resolution mass...... spectrometry (LC-HRMS) showed that CLP biosynthesis is regulated by nunF. Quantitative real-time PCR analysis indicated that transcription of the NRPS genes catalyzing CLP production is strongly reduced when nunF is mutated indicating that nunF is part of the nun-nup regulon. Swarming and biofilm formation...... that environmental elicitors may also influence nunF expression which upon activation regulates nunamycin and nunapeptin production required for the growth inhibition of phytopathogens....

Antimicrobial activity of gallic acid against food-related Pseudomonas strains and its use as biocontrol tool to improve the shelf life of fresh black truffles.

Science.gov (United States)

Sorrentino, Elena; Succi, Mariantonietta; Tipaldi, Luca; Pannella, Gianfranco; Maiuro, Lucia; Sturchio, Marina; Coppola, Raffaele; Tremonte, Patrizio

2018-02-02

Refrigeration alone or in combination with other technologies represents the main tool used in the last decades to preserve the freshness of black truffles. This is principally due to the delicateness and vulnerability of this edible hypogeous fungus, so that other invasive preservation practices cannot be adopted. However, the proliferation of some microbial species during the cold storage still represents an unsolved problem. Pseudomonads are among the main spoiler bacteria responsible for the deterioration of refrigerated black truffles. Their growth ability at low temperatures requires the use of additional hurdles to prolong the shelf-life of truffles without altering their major features. The use of natural compounds may represent an alternative system for the biocontrol of this kind of product. Specifically, gallic acid (GA) is a phenolic acid naturally present in different foods, whose effectiveness was in vitro demonstrated against Pseudomonas spp. In our study, we reported the antimicrobial activity expressed by GA not only in vitro, using as target bacteria Pseudomonas putida DSMZ 291 T , P. fluorescens DSMZ 50090 T , P. fragi DSMZ 3456 T and Pseudomonas spp. P30-4, previously isolated from black truffles, but also in situ on fresh black truffles stored at 4°C for 28days. Our results showed Minimum Inhibitory Concentrations (MIC) of 2.5mg/mL GA for all tested strains, except for P. fluorescens DSMZ 50090 T , having a MIC corresponding to 5mg/mL GA. The Minimum Bactericidal Concentration (MBC) was 10mg/mL for all strains. The analysis of kinetic parameters showed that the survival declined passing from 2.5 to 10mg/mL GA concentrations, with P. fluorescens confirmed to be the most resistant strain. Moreover, images obtained from Scanning Electron Microscopy revealed that Pseudomonas cells were strongly injured by the treatment with GA at 2.5mg/mL concentration, displaying visible pores on the cellular surfaces, absence of flagella and lysis with loss of

Effect of Genetically Modified Pseudomonas putida WCS358r on the Fungal Rhizosphere Microflora of Field-Grown Wheat

NARCIS (Netherlands)

Glandorf, D.C.M.; Verheggen, Patrick; Jansen, Timo; Jorritsma, J.-W.; Smit, Eric; Leeflang, Paula; Wernars, Karel; Thomashow, L.S.; Laureijs, Eric; Thomas-Oates, J.E.; Bakker, P.A.H.M.; Loon, L.C. van

2001-01-01

We released genetically modified Pseudomonas putida WCS358r into the rhizospheres of wheat plants. The two genetically modified derivatives, genetically modified microorganism (GMM) 2 and GMM 8, carried the phz biosynthetic gene locus of strain P. fluorescens 2-79 and constitutively produced the

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.

Inoculación al suelo con Pseudomonas fluorescens, Azospirillum oryzae, Bacillus subtilis y microorganismos de montaña (mm y su efecto sobre un sistema de rotación soya-tomate bajo condiciones de invernadero

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Leida Castro Barquero

2015-11-01

Full Text Available Se evaluó un sistema de rotación soyatomate, con incorporación de biomasa verde y aplicación de inóculos microbianos individuales y en mezcla sobre el crecimiento de las plantas y propiedades edáficas; para ello se evaluaron en invernadero por 24 meses los siguientes 9 tratamientos: solo tomate (T; rotación tomate-soya (TS; rotación tomate-soya con inoculaciones individuales de Azospirillum oryzae (A; de Pseudomonas fluorescens (P; de Bacillus subtilis (B; de microorganismos de montaña (MM; y las inoculaciones en mezcla de B. subtilis y P. fluorescens (BP; de B. subtilis, P. fluorescens y A. oryzae (BPA; de B. subtilis, P. fluorescens, Azospirillum sp. y MM (BPAMM. Se evaluaron las variables físicas: densidad aparente y de partículas; conductividad hidráulica; poros totales; estabilidad de agregados; resistencia a la penetración (RP; las variables químicas: pH; conductividad eléctrica; contenido de N y C; relación C/N; contenido de nutrientes en suelos y foliares; las variables biológicas: respiración de suelos, unidades formadoras de colonias de hongos, bacterias y actinomicetos y el peso fresco y seco foliar. Las variables físicas no fueron afectadas por los tratamientos, con excepción de RP, que fue mayor en el tratamiento T. Las variables biológicas y químicas fueron sensibles a los tratamientos, con valores significativamente más altos en presencia de MM. Destaca el incremento del P en solución de suelo en tratamientos a los que se adicionó MM: pasó de 6 a 20 mg.l-1; esta condición se reflejó además en la cantidad de P en el tejido foliar al final del ensayo. Se determinó que el pH, CE y la respiración del suelo fueron afectados por la interacción entre los tratamientos aplicados y el tiempo transcurrido; los mayores valores se obtuvieron al final del ensayo y en los tratamientos con MM.

Enhanced biosorption of mercury(II) and cadmium(II) by cold-induced hydrophobic exobiopolymer secreted from the psychrotroph Pseudomonas fluorescens BM07

Energy Technology Data Exchange (ETDEWEB)

Zamil, Sheikh Shawkat; Choi, Mun Hwan; Song, Jung Hyun; Park, Hyunju; Xu, Ju; Yoon, Sung Chul [Gyeongsang National Univ., Jinju (Korea). Nano-Biomaterials Science Lab.; Chi, Ki-Whan [Ulsan Univ. (Korea). Dept. of Chemistry

2008-09-15

The cells of psychrotrophic Pseudomonas fluorescens BM07 were found to secrete large amounts of exobiopolymer (EBP) composed of mainly hydrophobic (water insoluble) polypeptide(s) (as contain {proportional_to}50 mol% hydrophobic amino acids, lacking cysteine residue) when grown on fructose containing limited M1 medium at the temperatures as low as 0-10 C but trace amount at high (30 C, optimum growth) temperature. Two types of nonliving BM07 cells (i.e., cells grown at 30 C and 10 C) as well as the freeze-dried EBP were compared for biosorption of mercury (Hg(II)) and cadmium (Cd(II)). The optimum adsorption pH was found 7 for Hg(II) but 6 for Cd(II), irrespective of the type of biomass. Equilibrium adsorption data well fitted the Langmuir adsorption model. The maximum adsorption (Q{sub max}) was 72.3, 97.4, and 286.2 mg Hg(II)/g dry biomass and 18.9, 27.0, and 61.5 mg Cd(II)/g dry biomass for cells grown at 30 C and 10 C and EBP, respectively, indicating major contribution of heavy metal adsorption by cold-induced EBP. Mercury(II) binding induced a significant shift of infrared (IR) amide I and II absorption of EBP whereas cadmium(II) binding showed only a very little shift. These IR shifts demonstrate that mercury(II) and cadmium(II) might have different binding sites in EBP, which was supported by X-ray diffraction and differential scanning calorimetric analysis and sorption results of chemically modified biomasses. This study implies that the psychrotrophs like BM07 strain may play an important role in the bioremediation of heavy metals in the temperate regions especially in the inactive cold season. (orig.)

Non-target effects of the microbial control agents Pseudomonas fluorescens DR54 and Clonostachys rosea IK726 in soils cropped with barley followed by sugar beet: a greenhouse assessment

DEFF Research Database (Denmark)

Johansen, A.; Knudsen, I. M. B.; Binnerup, S. J.

2005-01-01

Non-target effects of a bacterial (Pseudomonas fluorescens DR54) and a fungal (Clonostachys rosea IK726) microbial control agent (MCA), on the indigenous microbiota in bulk soil and rhizosphere of barley, and subsequent a sugar beet crop, were studied in a greenhouse experiment. MCAs were...... introduced by seed and soil inoculation. Bulk and rhizosphere soils were sampled regularly during the growth of barley and sugar beet. The soils were assayed for the fate of MCAs and various features of the indigenous soil microbiota. At the end of the experiment (193 d), DR54 and IK726 had declined...... by a factor of 106 and 20, respectively, and DR54 showed a short-lasting growth increase in the sugar beet rhizosphere. In general, the non-target effects were small and transient. IK726 seemed to have general stimulating effects on soil enzyme activity and the soil microbiota, and resulted in a significant...

Rhizosphere competence of wild-type and genetically-engineered Pseudomonas brassicacearum is affected by the crop species

Science.gov (United States)

2,4-diacetylphloroglucinol (2,4-DAPG)-producing Pseudomonas brassicacearum Q8r1-96 is a highly effective biocontrol agent of take-all disease of wheat. Strain Z30-97, a recombinant derivative of Q8r1-96 containing the phzABCDEFG operon from P. synxantha (formerly P. fluorescens) 2-79 inserted into ...

Comparative genomic and functional analyses: unearthing the diversity and specificity of nematicidal factors in Pseudomonas putida strain 1A00316

Science.gov (United States)

Guo, Jing; Jing, Xueping; Peng, Wen-Lei; Nie, Qiyu; Zhai, Yile; Shao, Zongze; Zheng, Longyu; Cai, Minmin; Li, Guangyu; Zuo, Huaiyu; Zhang, Zhitao; Wang, Rui-Ru; Huang, Dian; Cheng, Wanli; Yu, Ziniu; Chen, Ling-Ling; Zhang, Jibin

2016-01-01

We isolated Pseudomonas putida (P. putida) strain 1A00316 from Antarctica. This bacterium has a high efficiency against Meloidogyne incognita (M. incognita) in vitro and under greenhouse conditions. The complete genome of P. putida 1A00316 was sequenced using PacBio single molecule real-time (SMRT) technology. A comparative genomic analysis of 16 Pseudomonas strains revealed that although P. putida 1A00316 belonged to P. putida, it was phenotypically more similar to nematicidal Pseudomonas fluorescens (P. fluorescens) strains. We characterized the diversity and specificity of nematicidal factors in P. putida 1A00316 with comparative genomics and functional analysis, and found that P. putida 1A00316 has diverse nematicidal factors including protein alkaline metalloproteinase AprA and two secondary metabolites, hydrogen cyanide and cyclo-(l-isoleucyl-l-proline). We show for the first time that cyclo-(l-isoleucyl-l-proline) exhibit nematicidal activity in P. putida. Interestingly, our study had not detected common nematicidal factors such as 2,4-diacetylphloroglucinol (2,4-DAPG) and pyrrolnitrin in P. putida 1A00316. The results of the present study reveal the diversity and specificity of nematicidal factors in P. putida strain 1A00316. PMID:27384076

Phenylacetic acid-producing Rhizoctonia solani represses the biosynthesis of nematicidal compounds in vitro and influences biocontrol of Meloidogyne incognita in tomato by Pseudomonas fluorescens strain CHA0 and its GM derivatives.

Science.gov (United States)

Siddiqui, I A; Shaukat, S S

2005-01-01

The aim of the present investigation was to determine the influence of Rhizoctonia solani and its pathogenicity factor on the production of nematicidal agent(s) by Pseudomonas fluorescens strain CHA0 and its GM derivatives in vitro and nematode biocontrol potential by bacterial inoculants in tomato. One (Rs7) of the nine R. solani isolates from infected tomato roots inhibited seedling emergence and caused root rot in tomato. Thin layer chromatography revealed that culture filtrates of two isolates (Rs3 and Rs7) produced brown spots at Rf-values closely similar to synthetic phenylacetic acid (PAA), a phytotoxic factor. Filtrates from isolate Rs7, amended with the growth medium of P. fluorescens, markedly repressed nematicidal activity and PhlA'-'LacZ reporter gene expression of the bacteria in vitro. On the contrary, isolate Rs4 enhanced nematicidal potential of a 2,4-diacetylphloroglucinol overproducing mutant, CHA0/pME3424, of P. fluorescens strain CHA0 in vitro. Therefore, R. solani isolates Rs4 and Rs7 were tested more rigorously for their potential to influence biocontrol effectiveness of the bacterial agents. Methanol extract of the culture filtrates of PAA-producing isolate Rs7 resulting from medium amended with phenylalanine enhanced fungal repression of the production of nematicidal agents by bacteria, while amendments with zinc or molybdenum eliminated such fungal repression, thereby restoring bacterial potential to cause nematode mortality in vitro. A pot experiment was carried out, 3-week-old tomato seedlings were infested with R. solani isolates Rs4 or Rs7 and/or inoculated with Meloidogyne incognita, the root-knot nematode. The infested soil was treated with aqueous cell suspensions (10(8) CFU) of P. fluorescens strain CHA0 or its GM derivatives or left untreated (as a control). Observations taken 45 days after nematode inoculation revealed that, irrespective of the bacterial treatments, galling intensity per gram of fresh tomato roots was markedly

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.

Impact of biocontrol Pseudomonas fluorescens CHA0 and a genetically modified derivative on the diversity of culturable fungi in the cucumber rhizosphere.

Science.gov (United States)

Girlanda, M; Perotto, S; Moenne-Loccoz, Y; Bergero, R; Lazzari, A; Defago, G; Bonfante, P; Luppi, A M

2001-04-01

Little is known about the effects of Pseudomonas biocontrol inoculants on nontarget rhizosphere fungi. This issue was addressed using the biocontrol agent Pseudomonas fluorescens CHA0-Rif, which produces the antimicrobial polyketides 2,4-diacetylphloroglucinol (Phl) and pyoluteorin (Plt) and protects cucumber from several fungal pathogens, including Pythium spp., as well as the genetically modified derivative CHA0-Rif(pME3424). Strain CHA0-Rif(pME3424) overproduces Phl and Plt and displays improved biocontrol efficacy compared with CHA0-Rif. Cucumber was grown repeatedly in the same soil, which was left uninoculated, was inoculated with CHA0-Rif or CHA0-Rif(pME3424), or was treated with the fungicide metalaxyl (Ridomil). Treatments were applied to soil at the start of each 32-day-long cucumber growth cycle, and their effects on the diversity of the rhizosphere populations of culturable fungi were assessed at the end of the first and fifth cycles. Over 11,000 colonies were studied and assigned to 105 fungal species (plus several sterile morphotypes). The most frequently isolated fungal species (mainly belonging to the genera Paecilomyces, Phialocephala, Fusarium, Gliocladium, Penicillium, Mortierella, Verticillium, Trichoderma, Staphylotrichum, Coniothyrium, Cylindrocarpon, Myrothecium, and Monocillium) were common in the four treatments, and no fungal species was totally suppressed or found exclusively following one particular treatment. However, in each of the two growth cycles studied, significant differences were found between treatments (e.g., between the control and the other treatments and/or between the two inoculation treatments) using discriminant analysis. Despite these differences in the composition and/or relative abundance of species in the fungal community, treatments had no effect on species diversity indices, and species abundance distributions fit the truncated lognormal function in most cases. In addition, the impact of treatments at the 32-day

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.

Bioremediation of Petroleum hydrocarbon by using Pseudomonas species isolated from Petroleum contaminated soil

OpenAIRE

Vijay Kumar; Simranjeet Singh; Anu Manhas; Joginder Singh; Sourav Singla; Parvinder Kaur; Shivika Data; Pritika Negi; Arjun Kalia

2014-01-01

A newly isolated strain Pseudomonas fluorescens (Accession number KF 279042.1) have potential in diesel degradation and can be recommended for bioremediation of sites that are contaminated with diesel. This bacterium was characterized on the basis of microbiological, biochemical and molecular analysis. Bacterial growth optimization was studied based on carbon source, nitrogen source, pH and temperature. The strain was selected based on its ability to show growth in medium containing diesel. I...

An N-terminal Retention Module Anchors the Giant Adhesin LapA of Pseudomonas fluorescens at the Cell Surface: A Novel Sub-family of Type I Secretion Systems.

Science.gov (United States)

Smith, T Jarrod; Font, Maria E; Kelly, Carolyn M; Sondermann, Holger; O'Toole, George A

2018-02-05

LapA of Pseudomonas fluorescens Pf0-1 belongs to a diverse family of cell surface associated bacterial adhesins that are secreted via the type-1 secretion system (T1SS). We previously reported that the periplasmic protease LapG cleaves the N-terminus of LapA at a canonical dialanine motif to release the adhesin from the cell surface under conditions unfavorable to biofilm formation, thus decreasing biofilm formation. Here, we characterize LapA as the first type 1 secreted substrate that does not follow the "one-step" rule of T1SS. Rather, a novel N-terminal element, called the retention module (RM), localizes LapA at the cell surface as a secretion intermediate. Our genetic, biochemical, and molecular modeling analysis support a model wherein LapA is tethered to the cell surface through its T1SS outer membrane TolC-like pore, LapE, until LapG cleaves LapA in the periplasm. We further demonstrate this unusual retention strategy is likely conserved among LapA-like proteins, and reveals a new subclass of T1SS ABC transporters involved in transporting this group of surface-associated, LapA-like adhesins. These studies demonstrate a novel cell surface retention strategy used throughout the Proteobacteria and highlight a previously unappreciated flexibility of function for T1SS. Importance. Bacteria have evolved multiple secretion strategies to interact with their environment. For many bacteria, the secretion of cell surface associated adhesins is key for initiating contact with a preferred substratum to facilitate biofilm formation. Our work demonstrates that P. fluorescens uses a previously unrecognized secretion strategy to retain the giant adhesin LapA at its cell surface. Further, we identify likely LapA-like adhesins in various pathogenic and commensal Proteobacteria and provide phylogenetic evidence that these adhesins are secreted by a new subclass of T1SS ABC transporters. Copyright © 2018 American Society for Microbiology.

The biocontrol endophytic bacterium Pseudomonas fluorescens PICF7 induces systemic defense responses in aerial tissues upon colonization of olive roots

Directory of Open Access Journals (Sweden)

Carmen eGómez-Lama Cabanás

2014-09-01

Full Text Available Pseudomonas fluorescens PICF7, a native olive root endophyte and effective biocontrol agent (BCA against Verticillium wilt of olive, is able to trigger a broad range of defense responses in root tissues of this woody plant. In order to elucidate whether strain PICF7 also induces systemic defense responses in above-ground organs, aerial tissues of olive plants grown under non-gnotobiotic conditions were collected at different time points after root bacterization with this endophytic BCA. A suppression subtractive hybridization (SSH cDNA library, enriched in up-regulated genes, was generated. This strategy enabled the identification of 376 ESTs (99 contigs and 277 singlets, many of them related to response to different stresses. Five ESTs, involved in defense responses, were selected to carry out time-course quantitative real-time PCR (qRT-PCR experiments aiming to: (i validate the induction of these genes, and (ii shed light on their expression pattern along time (from 1 to 15 days. Induction of olive genes potentially coding for lypoxigenase 2, catalase, 1-aminocyclopropane-1-carboxylate oxidase and phenylananine ammonia-lyase was thus confirmed at some time points. Computational analysis also revealed that different transcription factors were up-regulated in olive aerial tissues (i.e. jerf, bHLH, WRKYs, as previously reported for roots. Results confirmed that root colonization by this endophytic bacterium does not only trigger defense responses in this organ but also mount a wide array of systemic defense responses in distant tissues (stems, leaves. This sheds light on how olive plants respond to the ‘non-hostile’ colonization by a bacterial endophyte and how induced defense response can contribute to the biocontrol activity of strain PICF7.

A full-length Plasmodium falciparum recombinant circumsporozoite protein expressed by Pseudomonas fluorescens platform as a malaria vaccine candidate.

Directory of Open Access Journals (Sweden)

Amy R Noe

Full Text Available The circumsporozoite protein (CSP of Plasmodium falciparum is a major surface protein, which forms a dense coat on the sporozoite's surface. Preclinical research on CSP and clinical evaluation of a CSP fragment-based RTS, S/AS01 vaccine have demonstrated a modest degree of protection against P. falciparum, mediated in part by humoral immunity and in part by cell-mediated immunity. Given the partial protective efficacy of the RTS, S/AS01 vaccine in a recent Phase 3 trial, further improvement of CSP-based vaccines is crucial. In this report, we describe the preclinical development of a full-length, recombinant CSP (rCSP-based vaccine candidate against P. falciparum malaria suitable for current Good Manufacturing Practice (cGMP production. Utilizing a novel high-throughput Pseudomonas fluorescens expression platform, we demonstrated greater efficacy of full-length rCSP as compared to N-terminally truncated versions, rapidly down-selected a promising lead vaccine candidate, and developed a high-yield purification process to express immunologically active, intact antigen for clinical trial material production. The rCSP, when formulated with various adjuvants, induced antigen-specific antibody responses as measured by enzyme-linked immunosorbent assay (ELISA and immunofluorescence assay (IFA, as well as CD4+ T-cell responses as determined by ELISpot. The adjuvanted rCSP vaccine conferred protection in mice when challenged with transgenic P. berghei sporozoites containing the P. falciparum repeat region of CSP. Furthermore, heterologous prime/boost regimens with adjuvanted rCSP and an adenovirus type 35-vectored CSP (Ad35CS showed modest improvements in eliciting CSP-specific T-cell responses and anti-malarial protection, depending on the order of vaccine delivery. Collectively, these data support the importance of further clinical development of adjuvanted rCSP, either as a stand-alone product or as one of the components in a heterologous prime

Synthesis of amino-silane modified superparamagnetic Fe{sub 3}O{sub 4} nanoparticles and its application in immobilization of lipase from Pseudomonas fluorescens Lp1

Energy Technology Data Exchange (ETDEWEB)

Kanimozhi, S., E-mail: skanimo@gmail.com [Department of Biotechnology, Sathyabama University, Jeppiaar Nagar, Rajivgandhi Salai, Chennai 600119, Tamil Nadu (India); Perinbam, K. [Department of Plant Biology and Biotechnology, Nandanam Arts College (Men), Chennai 600035, Tamil Nadu (India)

2013-05-15

Highlights: ► Magnetic nanoparticles were synthesized by chemical co-precipitation method. ► Surface was functionalized with amino-silane and used for lipase immobilization. ► Characterized through TEM, SEM, XRD, FT-IR and VSM analysis. ► The functionalization and immobilization did not affect the magnetite properties. ► The immobilized lipase showed greater functional property than free lipase. - Abstract: Superparamagnetic nanoparticles (Fe{sub 3}O{sub 4}–magnetite) were prepared by chemical co-precipitation method and their surface was functionalized with 3-aminopropyltriethoxysilane via silanization reaction to obtain amino functionalized magnetic nanoparticles. The purified lipase from Pseudomonas fluorescens Lp1 was immobilized onto functionalized magnetite using glutaraldehyde as the coupling agent. The characterization of the nanoparticles was done by scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, vibrating sample magnetometry and Fourier transformed infrared spectroscopy. The size of the magnetite was measured about 10–30 nm. The results of characterization study revealed the successful immobilization of lipase on to functionalized magnetite. The saturation magnetization of magnetic nanoparticles was found to be 28.34 emu/g whereas the immobilized magnetic nanoparticle was 17.074 emu/g. The immobilized lipase had greater activity at 50 °C and thermal stability upto 70 °C. It exhibited excellent reusability for 4 cycles and storage stability upto 15 days by retaining 75% of its initial activity.

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.

Study of the biological impact of Pseudomonas spp.fluoresents on hemolyphatic metabolites and histology of the digestive tract of larvae 15 migratory locust Locusta migratoria

International Nuclear Information System (INIS)

Oulebsir- Mohan, H.; Doumandji-Mitiche, B.

2012-01-01

This study allows to test the effect of entomopathogenic bacteria of Pseudomonas fluorescens bv III and Pseudomonas fluorescence bv V on the haemolymph of Locusta migratoria metabolites, namely proteins and carbohydrates as well as on the histology of the digestive system of fifth stage larvae of migratory locust Locusta migratoria. The results show an important decrease of haemolymph protein concentration compared to controls with an increase in carbohydrate concentration. Examination of histological sections of various parts of the digestive tract showed some changes in treated. (author)

Polymorphism of a lipid extract from Pseudomonas fluorescens: Structure analysis of a hexagonal phase and of a novel cubic phase of extinction symbol Fd--

International Nuclear Information System (INIS)

Mariani, P.; Rivas, E.; Delacroix, H.; Luzzati, V.

1990-01-01

The phase diagram of the Pseudomonas fluorescens lipid extract is unusual, in the sense that it displays a cubic phase straddled by a hexagonal phase. The hexagonal phase was studied over an extended concentration range, and the reflections were phased on the assumption that the structure contains circular cylinders of known radius. The cubic phase, whose extinction symbol is Fd--, was analyzed by reference to space group No. 227 (Fd3m). The phases of the reflections were determined by using a novel pattern recognition approach, based upon the notion that the average fourth power of the electron density contrast 4 > is dependent on chemical composition but not on physical structure, provided that the function Δr(r) satisfies the constraints = 0 and 2 > = 1. The authors analyzed two cubic samples of different composition: for each of them they generated all the phase combinations compatible with the X-ray scattering data and they searched for those whose 4 > best agrees with the hexagonal phase. They concluded that the chemical composition of the phases being compared must be identical, that the X-ray scattering data should not be truncated artificially, and that the apodization must be mild so that the curvature takes a value intermediate between those corresponding to the raw data of the two phases. The structure may be visualized as a 3D generalization of the lipid monolayer. The structure, moreover, does not belong to the class of the infinite periodic surfaces without intersections

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.

Influence of Nitrogen Source on 2,4-diacetylphloroglucinol Production by the Biocontrol Strain Pf-5

OpenAIRE

M, Hultberg; B, Alsanius

2008-01-01

The production of 2,4-diacetylphloroglucinol (DAPG) by the biocontrol agent Pseudomonas fluorescens Pf-5 was studied in nutrient-solution based media with varying nitrogen content. No production of DAPG was observed when organic nitrogen was omitted from the media, regardless of the inorganic nitrogen source used. Furthermore, a micromolar concentration range of organic nitrogen was insufficient to sustain production. When a millimolar concentration range of organic nitrogen was used, DAPG pr...

A novel enterocin T1 with anti-Pseudomonas activity produced by Enterococcus faecium T1 from Chinese Tibet cheese.

Science.gov (United States)

Liu, Hui; Zhang, Lanwei; Yi, Huaxi; Han, Xue; Gao, Wei; Chi, Chunliang; Song, Wei; Li, Haiying; Liu, Chunguang

2016-02-01

An enterocin-producing Enterococcus faecium T1 was isolated from Chinese Tibet cheese. The enterocin was purified by SP-Sepharose and reversed phase HPLC. It was identified as unique from other reported bacteriocins based on molecular weight (4629 Da) and amino acid compositions; therefore it was subsequently named enterocin T1. Enterocin T1 was stable at 80-100 °C and over a wide pH range, pH 3.0-10.0. Protease sensitivity was observed to trypsin, pepsin, papain, proteinase K, and pronase E. Importantly, enterocin T1 was observed to inhibit the growth of numerous Gram-negative and Gram-positive bacteria including Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes. Take together, these results suggest that enterocin T1 is a novel bacteriocin with the potential to be used as a bio-preservative to control Pseudomonas spp. in food.

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

Chemical resistance of the gram-negative bacteria to different sanitizers in a water purification system

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Penna Thereza CV

2006-08-01

Full Text Available Abstract Background Purified water for pharmaceutical purposes must be free of microbial contamination and pyrogens. Even with the additional sanitary and disinfecting treatments applied to the system (sequential operational stages, Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were isolated and identified from a thirteen-stage purification system. To evaluate the efficacy of the chemical agents used in the disinfecting process along with those used to adjust chemical characteristics of the system, over the identified bacteria, the kinetic parameter of killing time (D-value necessary to inactivate 90% of the initial bioburden (decimal reduction time was experimentally determined. Methods Pseudomonas aeruginosa, Pseudomonas fluorescens, Pseudomonas alcaligenes, Pseudomonas picketti, Flavobacterium aureum, Acinetobacter lowffi and Pseudomonas diminuta were called in house (wild bacteria. Pseudomonas diminuta ATCC 11568, Pseudomonas alcaligenes INCQS , Pseudomonas aeruginosa ATCC 15442, Pseudomonas fluorescens ATCC 3178, Pseudomonas picketti ATCC 5031, Bacillus subtilis ATCC 937 and Escherichia coli ATCC 25922 were used as 'standard' bacteria to evaluate resistance at 25°C against either 0.5% citric acid, 0.5% hydrochloric acid, 70% ethanol, 0.5% sodium bisulfite, 0.4% sodium hydroxide, 0.5% sodium hypochlorite, or a mixture of 2.2% hydrogen peroxide (H2O2 and 0.45% peracetic acid. Results The efficacy of the sanitizers varied with concentration and contact time to reduce decimal logarithmic (log10 population (n cycles. To kill 90% of the initial population (or one log10 cycle, the necessary time (D-value was for P. aeruginosa into: (i 0.5% citric acid, D = 3.8 min; (ii 0.5% hydrochloric acid, D = 6.9 min; (iii 70% ethanol, D = 9.7 min; (iv 0.5% sodium bisulfite, D = 5.3 min; (v 0.4% sodium hydroxide, D = 14.2 min; (vi 0.5% sodium

Evidence for a role of biosurfactants produced by Pseudomonas fluorescens in the spoilage of fresh aerobically stored chicken meat.

Science.gov (United States)

Mellor, Glen E; Bentley, Jessica A; Dykes, Gary A

2011-08-01

Fresh chicken meat is a fat-rich environment and we therefore hypothesised that production of biosurfactants to increase bioavailability of fats may represent one way in which spoilage bacteria might enhance the availability of nutrients. Numbers of Pseudomonas were determined on a total of 20 fresh and 20 spoiled chicken thighs with skin. A total of 400 randomly isolated Pseudomonas colonies from fresh (200) and spoiled (200) chicken were screened for the presence of biosurfactant production. Biosurfactant producing strains represented 5% and 72% of the Pseudomonas spp. isolates from fresh (mean count 2.3 log(10) cfu g(-1)) and spoiled (mean count 7.4 log(10) cfu g(-1)) chicken skin, respectively. Partially-purified biosurfactants derived from a subgroup of four Pseudomonasfluorescens strains obtained through the screening process were subsequently used to investigate the role that the addition of these compounds plays in the spoilage of aerobically stored chicken. Emulsification potential of the four selected biosurfactants was measured against a range of hydrocarbons and oils. All four biosurfactants displayed a greater ability to emulsify rendered chicken fat than hydrocarbons (paraffin liquid, toluene and hexane) and oils (canola, olive, sunflower and vegetable). Storage trials (4 °C) of chicken meat treated with the four selected biosurfactants revealed a significantly greater (P increase in total aerobic count (1.3-1.7 log(10) cfu g(-1)) occurred following one day of incubation. These results indicate that biosurfactants produced by Pseudomonas spp. may play an important role in the spoilage of aerobically stored chicken meat by making nutrients more freely available and providing strains producing them with a competitive advantage. Copyright © 2011 Elsevier Ltd. All rights reserved.

Hydrocarbonoclastic bacteria of the genus Pseudomonas in Samanea saman (Jacq. Merr. rhizosphere

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Juliana Coromoto Mayz

2017-01-01

Full Text Available The research goal includes isolation, characterization and identification of Pseudomonas species existing in the rhizosphere of a legume present (colonizing or survivor in a savanna soil polluted by an oil spill, in order to explain the support of the growth of this leguminous plant through the reduction of the toxicity of spilled oil (hydrocarbonoclastic effects. The site is located at Amana del Tamarindo village entrance, Monagas State, Venezuela (9 ° 38' 52 "N, 63 ° 7' 20" E, 46 masl. An area of 50 m2 was sampled.  In concordance to the descriptions, keys, and comparison with the UOJ Herbarium exsiccatae, the legume collected was identified as Samanea saman (Jacq. Merr., which belongs to the Fabaceae family. The results of the biochemical characterization and the production of pyocyanine and fluorescein pigments allowed identifying 10 isolates as P. fluorescens, 5 as P. putida and 5 as P. aeruginosa. Samanea saman is recommended for re-vegetation of the contaminated area.

Characterization of initial events in bacterial surface colonization by two Pseudomonas species using image analysis.

Science.gov (United States)

Mueller, R F; Characklis, W G; Jones, W L; Sears, J T

1992-05-01

The processes leading to bacterial colonization on solid-water interfaces are adsorption, desorption, growth, and erosion. These processes have been measured individually in situ in a flowing system in real time using image analysis. Four different substrata (copper, silicon, 316 stainless-steel and glass) and 2 different bacterial species (Pseudomonas aeruginosa and Pseudomonas fluorescens) were used in the experiments. The flow was laminar (Re = 1.4) and the shear stress was kept constant during all experiments at 0.75 N m(-2). The surface roughness varied among the substrata from 0.002 microm (for silicon) to 0.015 microm (for copper). Surface free energies varied from 25.1 dynes cm(-1) for silicon to 31.2 dynes cm(-1) for copper. Cell curface hydrophobicity, reported as hydrocarbon partitioning values, ranged from 0.67 for Ps. fluorescens to 0.97 for Ps. aeruginosa.The adsorption rate coefficient varied by as much as a factor of 10 among the combinations of bacterial strain and substratum material, and was positively correlated with surface free energy, the surface roughness of the substratum, and the hydrophobicity of the cells. The probability of desorption decreased with increasing surface free energy and surface roughness of the substratum. Cell growth was inhibited on copper, but replication of cells overlying an initial cell layer was observed with increased exposure time to the cell-containing bulk water. A mathematical model describing cell accumulation on a substratum is presented.

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.

The complete genome sequence of the plant growth-promoting bacterium Pseudomonas sp. UW4.

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Jin Duan

Full Text Available The plant growth-promoting bacterium (PGPB Pseudomonas sp. UW4, previously isolated from the rhizosphere of common reeds growing on the campus of the University of Waterloo, promotes plant growth in the presence of different environmental stresses, such as flooding, high concentrations of salt, cold, heavy metals, drought and phytopathogens. In this work, the genome sequence of UW4 was obtained by pyrosequencing and the gaps between the contigs were closed by directed PCR. The P. sp. UW4 genome contains a single circular chromosome that is 6,183,388 bp with a 60.05% G+C content. The bacterial genome contains 5,423 predicted protein-coding sequences that occupy 87.2% of the genome. Nineteen genomic islands (GIs were predicted and thirty one complete putative insertion sequences were identified. Genes potentially involved in plant growth promotion such as indole-3-acetic acid (IAA biosynthesis, trehalose production, siderophore production, acetoin synthesis, and phosphate solubilization were determined. Moreover, genes that contribute to the environmental fitness of UW4 were also observed including genes responsible for heavy metal resistance such as nickel, copper, cadmium, zinc, molybdate, cobalt, arsenate, and chromate. Whole-genome comparison with other completely sequenced Pseudomonas strains and phylogeny of four concatenated "housekeeping" genes (16S rRNA, gyrB, rpoB and rpoD of 128 Pseudomonas strains revealed that UW4 belongs to the fluorescens group, jessenii subgroup.

The Complete Genome Sequence of the Plant Growth-Promoting Bacterium Pseudomonas sp. UW4

Science.gov (United States)

Duan, Jin; Jiang, Wei; Cheng, Zhenyu; Heikkila, John J.; Glick, Bernard R.

2013-01-01

The plant growth-promoting bacterium (PGPB) Pseudomonas sp. UW4, previously isolated from the rhizosphere of common reeds growing on the campus of the University of Waterloo, promotes plant growth in the presence of different environmental stresses, such as flooding, high concentrations of salt, cold, heavy metals, drought and phytopathogens. In this work, the genome sequence of UW4 was obtained by pyrosequencing and the gaps between the contigs were closed by directed PCR. The P. sp. UW4 genome contains a single circular chromosome that is 6,183,388 bp with a 60.05% G+C content. The bacterial genome contains 5,423 predicted protein-coding sequences that occupy 87.2% of the genome. Nineteen genomic islands (GIs) were predicted and thirty one complete putative insertion sequences were identified. Genes potentially involved in plant growth promotion such as indole-3-acetic acid (IAA) biosynthesis, trehalose production, siderophore production, acetoin synthesis, and phosphate solubilization were determined. Moreover, genes that contribute to the environmental fitness of UW4 were also observed including genes responsible for heavy metal resistance such as nickel, copper, cadmium, zinc, molybdate, cobalt, arsenate, and chromate. Whole-genome comparison with other completely sequenced Pseudomonas strains and phylogeny of four concatenated “housekeeping” genes (16S rRNA, gyrB, rpoB and rpoD) of 128 Pseudomonas strains revealed that UW4 belongs to the fluorescens group, jessenii subgroup. PMID:23516524

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.

Antimicrobial Activity of Various Plant Extracts on Pseudomonas Species Associated with Spoilage of Chilled Fish

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Osan Bahurmiz

2016-11-01

Full Text Available The antimicrobial activity of various plant extracts on Pseudomonas bacteria isolated from spoiled chilled tilapia (Oreochromis sp. was evaluated in this study. In the first stage of this study, red tilapia was subjected to chilled storage (4°C for 3 weeks, and spoilage bacteria were isolated and identified from the spoiled fish. Pseudomonas was the dominant bacteria isolated from the spoiled fish and further identification revealed that P. putida, P. fluorescens and Pseudomonas spp. were the main species of this group. In the second stage, methanolic extracts of 15 selected plant species were screened for their antimicrobial activity, by agar disc diffusion method, against the Pseudomonas isolates. Results indicated that most of the extracts had different degrees of activity against the bacterial isolates. The strongest activity was exhibited by bottlebrush flower (Callistemon viminalis extract. This was followed by extracts from guava bark (Psidium guajava and henna leaf (Lawsonia inermis. Moderate antimicrobial activities were observed in extracts of clove (Syzygium aromaticum, leaf and peel of tamarind (Tamarindus indica, cinnamon bark (Cinnamomum zeylanicum, wild betel leaf (Piper sarmentosum and fresh thyme (Thymus spp.. Weak or no antimicrobial activity was observed from the remaining extracts. The potential antimicrobial activity shown by some plant extracts in this study could significantly contribute to the fish preservation.

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.

Getting the ecology into the interactions between plants and the plant-growth promoting bacterium Pseudomonas fluorescens

NARCIS (Netherlands)

Hol, W.H.G.; Bezemer, T.M.; Biere, A.

2013-01-01

Plant growth-promoting rhizobacteria (PGPR) are increasingly appreciated for their contributions to primary productivity through promotion of growth and triggering of induced systemic resistance in plants. Here we focus on the beneficial effects of one particular species of PGPR (Pseudomonas

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

Kynurenine 3-monooxygenase from Pseudomonas fluorescens: substrate-like inhibitors both stimulate flavin reduction and stabilize the flavin-peroxo intermediate yet result in the production of hydrogen peroxide.

Science.gov (United States)

Crozier-Reabe, Karen R; Phillips, Robert S; Moran, Graham R

2008-11-25

Kynurenine 3-monooxygenase (KMO) is a flavin-dependent hydroxylase that catalyzes the conversion of l-kynurenine (l-Kyn) to 3-hydroxykynurenine (3OHKyn) in the pathway for tryptophan catabolism. KMO inhibition has been widely suggested as an early treatment for stroke and other neurological disorders that involve ischemia. We have investigated the reductive and the oxidative half-reactions of a stable form of KMO from Pseudomonas fluorescens (KMO). The binding of l-Kyn by the enzyme is relatively slow and involves at least two reversible steps. The rate constant for reduction of the flavin cofactor by NADPH increases by a factor of approximately 2.5 x 10(3) when l-Kyn is bound. The rate of reduction of the KMO.l-Kyn complex is 160 s(-1), and the K(d) for the NADPH complex is 200 microM with charge-transfer absorption bands for the KMO(RED).l-Kyn.NADP(+) complex accumulating after reduction. The reduction potential of KMO is -188 mV and is unresponsive to the addition of l-Kyn or other inhibitory ligands. KMO inhibitors whose structures are reminiscent of l-Kyn such as m-nitrobenzoylalanine and benzoylalanine also stimulate reduction of flavin by NADPH and, in the presence of dioxygen, result in the stoichiometric liberation of hydrogen peroxide, diminishing the perceived therapeutic potential of inhibitors of this type. In the presence of the native substrate, the oxidative half-reaction exhibits triphasic absorbance data. A spectrum consistent with that of a peroxyflavin species accumulates and then decays to yield the oxidized enzyme. This species then undergoes minor spectral changes that, based on flavin difference spectra defined in the presence of 3OHKyn, can be correlated with product release. The oxidative half-reaction observed in the presence of saturating benzoylalanine or m-nitrobenzoylalanine also shows the accumulation of a peroxyflavin species that then decays to yield hydrogen peroxide without hydroxylation.

Arsenic-contaminated soils. Genetically modified Pseudomonas spp. and their arsenic-phytoremediation potential

Energy Technology Data Exchange (ETDEWEB)

Sizova, O.I.; Kochetkov, V.V.; Validov, S.Z.; Boronin, A.M. [Inst. of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Moscow (Russian Federation); Kosterin, P.V.; Lyubun, Y.V. [Inst. of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov (Russian Federation)

2002-07-01

Sorghum was inoculated with Pseudomonas bacteria, including strains harboring an As-resistance plasmid, pBS3031, to enhance As-extraction by the plants. Pseudomonas strains (P. fluorescens 38a, P. putida 53a, and P. aureofaciens BS1393) were chosen because they are antagonistic to a wide range of phytopathogenic fungi and bacteria, and they can stimulate plant growth. The resistance of natural rhizospheric pseudomonads to sodium arsenite was assessed. Genetically modified Pseudomonas strains resistant to As(III)/As(V) were obtained via conjugation or transformation. The effects of the strains on the growth of sorghum on sodium-arsenite-containing soils were assessed. The conclusions from this study are: (1) It is possible to increase the survivability of sorghum growing in sodium-arsenite-containing soil by using rhizosphere pseudomonads. (2) The presence of pBS3031 offers the strains a certain selective advantage in arsenite-contaminated soil. (3) The presence of pBS3031 impairs plant growth, due to the As-resistance mechanism determined by this plasmid: the transformation of the less toxic arsenate into the more toxic, plant-root-available arsenite by arsenate reductase and the active removal of arsenite from bacterial cells. (4) Such a mechanism makes it possible to develop a bacteria-assisted phytoremediation technology for the cleanup of As-contaminated soils and is the only possible way of removing the soil-sorbed arsenates from the environment. (orig.)

Variable Copy Number, Intra-Genomic Heterogeneities and Lateral Transfers of the 16S rRNA Gene in Pseudomonas

Science.gov (United States)

Bodilis, Josselin; Nsigue-Meilo, Sandrine; Besaury, Ludovic; Quillet, Laurent

2012-01-01

Even though the 16S rRNA gene is the most commonly used taxonomic marker in microbial ecology, its poor resolution is still not fully understood at the intra-genus level. In this work, the number of rRNA gene operons, intra-genomic heterogeneities and lateral transfers were investigated at a fine-scale resolution, throughout the Pseudomonas genus. In addition to nineteen sequenced Pseudomonas strains, we determined the 16S rRNA copy number in four other Pseudomonas strains by Southern hybridization and Pulsed-Field Gel Electrophoresis, and studied the intra-genomic heterogeneities by Denaturing Gradient Gel Electrophoresis and sequencing. Although the variable copy number (from four to seven) seems to be correlated with the evolutionary distance, some close strains in the P. fluorescens lineage showed a different number of 16S rRNA genes, whereas all the strains in the P. aeruginosa lineage displayed the same number of genes (four copies). Further study of the intra-genomic heterogeneities revealed that most of the Pseudomonas strains (15 out of 19 strains) had at least two different 16S rRNA alleles. A great difference (5 or 19 nucleotides, essentially grouped near the V1 hypervariable region) was observed only in two sequenced strains. In one of our strains studied (MFY30 strain), we found a difference of 12 nucleotides (grouped in the V3 hypervariable region) between copies of the 16S rRNA gene. Finally, occurrence of partial lateral transfers of the 16S rRNA gene was further investigated in 1803 full-length sequences of Pseudomonas available in the databases. Remarkably, we found that the two most variable regions (the V1 and V3 hypervariable regions) had probably been laterally transferred from another evolutionary distant Pseudomonas strain for at least 48.3 and 41.6% of the 16S rRNA sequences, respectively. In conclusion, we strongly recommend removing these regions of the 16S rRNA gene during the intra-genus diversity studies. PMID:22545126

Antidiabetic and Antiobesity Effects of Artemether in db/db Mice

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Yu Guo

2018-01-01

Full Text Available This study is designed to investigate the effect of artemether on type 2 diabetic db/db mice. The experiments consisted of three groups: normal control (NC, db/+, 1% methylcellulose, intragastric administration, diabetic control (DM, db/db, 1% methylcellulose, intragastric administration, and artemether treated (artemether, db/db, 200 mg/kg of artemether, intragastric administration. The treatment lasted for two weeks. The food intake, body weight, and fasting blood glucose of mice were measured every three days. At the start and end of the experiment, the intraperitoneal glucose tolerance test (IPGTT and insulin tolerance test (IPITT were performed. We determined the serum insulin and glucagon levels by ELISA kits and calculated insulin resistance index (HOME-IR. HE staining was used to observe the morphologies of pancreas and liver in mice. The damage of pancreatic beta cells was evaluated by TUNEL staining and immunofluorescence. We found the following: (1 compared with the DM group, the food intake and weight increase rate of artemether group significantly reduced (P<0.05; (2 compared with pretreatment, artemether significantly reduced the fasting blood glucose levels, and the areas under the curves (AUCs of IPGTT were decreased significantly, increasing the tolerance to glucose of db/db mice. (P<0.05; (3 artemether improved hyperinsulinemia and decreased the AUCs of IPITT and HOME-IR, increasing the insulin sensitivity of db/db mice. (4 Artemether significantly ameliorated islet vacuolar degeneration and hepatic steatosis in db/db mice. (5 Artemether reduced the apoptosis of pancreatic beta cells and increased insulin secretion in db/db mice compared with DM group (P<0.05. Our results indicated that artemether significantly improved glucose homeostasis and insulin resistance and had the potential activity to prevent obesity, reduced the severity of fatty liver, and protected pancreatic beta cells, promising to treat type 2 diabetes.

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

Restructuring of the Gut Microbiome by Intermittent Fasting Prevents Retinopathy and Prolongs Survival in db/db Mice.

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Beli, Eleni; Yan, Yuanqing; Moldovan, Leni; Vieira, Cristiano P; Gao, Ruli; Duan, Yaqian; Prasad, Ram; Bhatwadekar, Ashay; White, Fletcher A; Townsend, Steven; Chan, Luisa; Ryan, Caitlin N; Morton, Daniel; Moldovan, Emil G; Chu, Fang-I; Oudit, Gavin Y; Derendorf, Hartmut; Adorini, Luciano; Wang, Xiaoxin X; Evans-Molina, Carmella; Mirmira, Raghavendra G; Boulton, Michael E; Yoder, Mervin C; Li, Qiuhong; Levi, Moshe; Busik, Julia V; Grant, Maria B

2018-04-30

Intermittent fasting (IF) protects against the development of metabolic diseases and cancer, but whether it can prevent diabetic microvascular complications is not known. In db/db mice, we examined the impact of long-term IF on diabetic retinopathy (DR). Despite no change in glycated hemoglobin, db/db mice on the IF regimen displayed significantly longer survival and a reduction in DR endpoints, including acellular capillaries and leukocyte infiltration. We hypothesized that IF mediated changes in the gut microbiota would produce beneficial metabolites and prevent the development of DR. Microbiome analysis revealed increased levels of Firmicutes and decreased Bacteroidetes and Verrucomicrobia Compared to db/db mice on ad-libitum (AL) feeding, changes in the microbiome of the db/db mice on IF were associated with increases in gut mucin, goblet cell number and villi length and reductions in plasma peptidoglycan. Consistent with the known modulatory effects of Firmicutes on bile acid (BA) metabolism, measurement of BAs demonstrated a significant increase of tauroursodeoxycholate (TUDCA), a neuroprotective BA, in db/db on IF but not in db/db on AL feeding. TGR-5, the TUDCA receptor, was found in neural cells of the retina primary ganglion cells. Expression of TGR5 did not change with IF or diabetes. However, IF reduced retinal TNF-α mRNA, which is a key downstream target of TGR-5 activation. Pharmacological activation of TGR5 using INT-767 prevented DR in a second diabetic mouse model. These findings support the concept that IF prevents DR by restructuring the microbiota towards species producing TUDCA and subsequent retinal protection by TGR5 activation. © 2018 by the American Diabetes Association.

Characterization of Extracellular Polymeric Substances Produced by Pseudomonas fragi Under Air and Modified Atmosphere Packaging.

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Wang, Guang-Yu; Ma, Fang; Wang, Hu-Hu; Xu, Xing-Lian; Zhou, Guang-Hong

2017-09-01

Extracellular polymeric substances (EPS) play an important role in bacterial biochemical properties. The characteristics of EPS from 2 strains of Pseudomonas fragi cultured in meat aerobically (control) and in modified atmosphere packaging (MAP) were studied. The amount and components of EPS, the surface properties, and the effect on biofilm formation of several spoilage organisms were evaluated. The results showed that MAP inhibited the growth of the P. fragi strains. Compared with the control, more loose and less bound EPS (containing protein and carbohydrate) were produced by P. fragi in MAP samples. MAP also caused increased cell autoaggregation and surface hydrophobicity. After the removal of the EPS, the surface property changes were strain-dependent, suggesting that membrane compositions were also changed. In addition, the EPS displayed significant antibiofilm activity on Pseudomonas fluorescens and Serratia liquefaciens. In conclusion, P. fragi strains not only modified the amount, components, and surface properties of EPS but also changed the cell membrane compositions to adapt to MAP stress. Moreover, EPS may play an important role in microbial community competitions. © 2017 Institute of Food Technologists®.

Growth response and nutrient uptake of blue pine (Pinus wallichiana seedlings inoculated with rhizosphere microorganisms under temperate nursery conditions

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M.A. Ahangar

2012-11-01

Full Text Available Microbial inoculants (Trichoderma harzianum, Pseudomonas fluorescens,Laccaria laccata inoculated either individually or in combinationsignificantly improved the growth and biomass of blue pine seedlings. The ECM fungus Laccaria laccata, when inoculated individually, showed significantly higher plant growth, followed by Pseudomonas fluorescens and Trichoderma harzianum. The combined inoculation of rhizosphere microorganisms showed synergistic growth promoting action and proved superior in enhancing the growth of blue pine than individual inoculation. Co-inoculation of L. laccata with P. fluorescens resulted in higher ectomycorrhizal root colonization. Uptake of nutrients (N, P, K was significantly improved by microbial inoculants, tested individually or in combination. Combined inoculation of L. laccata with T. harzianum and P. fluorescens significantly increased in N, P and K contents in blue pine seedlings as compared to control. Acid phosphatase activity in the rhizosphere of blue pine seedlings was also enhanced by these microorganisms. L. laccata exhibited higher acid phosphatase activity followed by P. fluorescens.

The Effect of Robusta Coffe Extract (Coffea Robusta) as Inhibitors of Growth Staphylococcus Aureus

OpenAIRE

Mumun Nurmilawati, Muhammad Ainul Yaqin

2015-01-01

Chlorogenic and caffeine acid, which is a non-volatile organic acids in coffee, which can prevent the growth of some gram-positive and gram-negative bacteria including Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus aureus, Bacillus cereus, Lactobacillus bulgaricus, Streptococcus lactis and Streptococcus faecalis.Subject used in this study was Staphylococcus aureus were divided into 5 groups, where each group consisting of 8 repetitions. The...

Isolation of Fungal Species from Fermentating Pearl Millet Gruel and ...

African Journals Online (AJOL)

Escherichia coli, Staphylococcus aureus, Bacillus cereus, Bacillus lichieniformis, Salmonella spp., Pseudomonas fluorescens, Pseudomonas aeruginosa, Pseudomonas syringae, Proteus sp. and Serratia sp. were utilized as indicator organisms. Secondary metabolites were also extracted from the respective moulds and ...

Comparative genomics of plant-associated Pseudomonas spp.: insights into diversity and inheritance of traits involved in multitrophic interactions.

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Joyce E Loper

2012-07-01

Full Text Available We provide here a comparative genome analysis of ten strains within the Pseudomonas fluorescens group including seven new genomic sequences. These strains exhibit a diverse spectrum of traits involved in biological control and other multitrophic interactions with plants, microbes, and insects. Multilocus sequence analysis placed the strains in three sub-clades, which was reinforced by high levels of synteny, size of core genomes, and relatedness of orthologous genes between strains within a sub-clade. The heterogeneity of the P. fluorescens group was reflected in the large size of its pan-genome, which makes up approximately 54% of the pan-genome of the genus as a whole, and a core genome representing only 45-52% of the genome of any individual strain. We discovered genes for traits that were not known previously in the strains, including genes for the biosynthesis of the siderophores achromobactin and pseudomonine and the antibiotic 2-hexyl-5-propyl-alkylresorcinol; novel bacteriocins; type II, III, and VI secretion systems; and insect toxins. Certain gene clusters, such as those for two type III secretion systems, are present only in specific sub-clades, suggesting vertical inheritance. Almost all of the genes associated with multitrophic interactions map to genomic regions present in only a subset of the strains or unique to a specific strain. To explore the evolutionary origin of these genes, we mapped their distributions relative to the locations of mobile genetic elements and repetitive extragenic palindromic (REP elements in each genome. The mobile genetic elements and many strain-specific genes fall into regions devoid of REP elements (i.e., REP deserts and regions displaying atypical tri-nucleotide composition, possibly indicating relatively recent acquisition of these loci. Collectively, the results of this study highlight the enormous heterogeneity of the P. fluorescens group and the importance of the variable genome in tailoring

Qing-Hua Granule induces GLP-1 secretion via bitter taste receptor in db/db mice.

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Li, Junyan; Xu, Jie; Hou, Ruifang; Jin, Xin; Wang, Jingyi; Yang, Na; Yang, Li; Liu, Li; Tao, Feng; Lu, Hao

2017-05-01

Qing-Hua Granule (QHG), the modified formulation of a classical Chinese prescription named Gegen Qinlian Decoction, was clinically employed to treat type 2 diabetes mellitus (T2DM) through regulation of glucagon-like peptide-1 (GLP-1). However, the potential mechanism is unknown. We investigate whether QHG induces GLP-1 secretion via activation of bitter taste receptor (TAS2R) pathway in the gastrointestinal tract of db/db mice. The db/db mice were intragastrically (i.g.) administered QHG (low/medium/high dose) once daily for 8 weeks. GLP-1 secretion was evaluated. The bitter receptor signaling pathway, which regulates GLP-1 secretion, including TAS2R5 (a subtype of TAS2R), α-gustducin (Gαgust), 1-phosphatidylinositol-4, 5-bisphosphate phosphodiesterase beta-2 (PLCβ2), transient receptor potential cation channel subfamily M member 5 (TRPM5), was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot and immunohistochemistry (IHC). The biochemical observations of ileum and pancreas tissue were detected histopathologically. Acquity Ultra Performance LCTM - Micromass ZQ 2000 (UPLC-MS) was used for the phytochemical analysis. QHG exhibited significant and dose-dependent effect on GLP-1 secretion in db/db mice, along with significant up-regulation of TAS2R5 mRNA level and activation of TAS2R pathway (p<0.05). In addition, QHG improved the histopathological structure of ileum and pancreatic tissue. Seventeen compounds were identified in QHG. In conclusion, QHG induces GLP-1 secretion in db/db mice, most likely through the bitter taste receptor pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Validity of leptin receptor-deficiency (db/db) type 2 diabetes mellitus mice as a model of secondary osteoporosis

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Huang, Le; You, Yong-Ke; Zhu, Tracy Y.; Zheng, Li-Zhen; Huang, Xiao-Ru; Chen, Hai-Yong; Yao, Dong; Lan, Hui-Yao; Qin, Ling

2016-06-01

This study aimed to evaluate the validation of the leptin receptor-deficient mice model for secondary osteoporosis associated with type 2 diabetes mellitus (T2DM) at bone micro-architectural level. Thirty three 36-week old male mice were divided into four groups: normal control (db/m) (n = 7), leptin receptor-deficient T2DM (db/db) (n = 8), human C-reactive protein (CRP) transgenic normal control (crp/db/m) (n = 7), and human CRP transgenic T2DM (crp/db/db) (n = 11). Lumber vertebrae (L5) and bilateral lower limbs were scanned by micro-CT to analyze trabecular and cortical bone quality. Right femora were used for three-point bending to analyze the mechanical properties. Trabecular bone quality at L5 was better in db/db or crp/db/db group in terms of bone mineral density (BMD), bone volume fraction, connectivity density, trabecular number and separation (all p  0.05). Maximum loading and energy yield in mechanical test were similar among groups while the elastic modulus in db/db and crp/db/db significantly lower than db/m. The leptin-receptor mice is not a proper model for secondary osteoporosis associated with T2DM.

Pseudomonas cichorii as the causal agent of midrib rot, an emerging disease of greenhouse-grown butterhead lettuce in Flanders.

Science.gov (United States)

Cottyn, Bart; Heylen, Kim; Heyrman, Jeroen; Vanhouteghem, Katrien; Pauwelyn, Ellen; Bleyaert, Peter; Van Vaerenbergh, Johan; Höfte, Monica; De Vos, Paul; Maes, Martine

2009-05-01

Bacterial midrib rot of greenhouse-grown butterhead lettuce (Lactuca sativa L. var. capitata) is an emerging disease in Flanders (Belgium) and fluorescent pseudomonads are suspected to play an important role in the disease. Isolations from infected lettuces, collected from 14 commercial greenhouses in Flanders, yielded 149 isolates that were characterized polyphasically, which included morphological characteristics, pigmentation, pathogenicity tests by both injection and spraying of lettuce, LOPAT characteristics, FAME analysis, BOX-PCR fingerprinting, 16S rRNA and rpoB gene sequencing, as well as DNA-DNA hybridization. Ninety-eight isolates (66%) exhibited a fluorescent pigmentation and were associated with the genus Pseudomonas. Fifty-five of them induced an HR+ (hypersensitive reaction in tobacco leaves) response. The other 43 fluorescent isolates were most probably saprophytic bacteria and about half of them were able to cause rot on potato tuber slices. BOX-PCR genomic fingerprinting was used to assess the genetic diversity of the Pseudomonas midrib rot isolates. The delineated BOX-PCR patterns matched quite well with Pseudomonas morphotypes defined on the basis of colony appearance and variation in fluorescent pigmentation. 16S rRNA and rpoB gene sequence analyses allowed most of the fluorescent isolates to be allocated to Pseudomonas, and they belonged to either the Pseudomonas fluorescens group, Pseudomonas putida group, or the Pseudomonas cichorii/syringae group. In particular, the isolates allocated to this latter group constituted the vast majority of HR+ isolates and were identified as P. cichorii by DNA-DNA hybridization. They were demonstrated by spray-inoculation tests on greenhouse-grown lettuce to induce the midrib rot disease and could be re-isolated from lesions of inoculated plants. Four HR+ non-fluorescent isolates associated with one sample that showed an atypical midrib rot were identified as Dickeya sp.

Bacteriocinogenicity and production of pyocins from Pseudomonas ...

African Journals Online (AJOL)

), P. fluorescens (13) and P. stutzeri (3) were isolated from Nigerian patients with burns, wound and skin infections, UTI, diarrhoea and eye infections. 81.5, 55.6, 76.9 and 33.3% of these species produced pyocins at a range of 410 – 670 g/ml.

Complex regulation of AprA metalloprotease in Pseudomonas fluorescens M114: evidence for the involvement of iron, the ECF sigma factor, PbrA and pseudobactin M114 siderophore.

Science.gov (United States)

Maunsell, Bláithín; Adams, Claire; O'Gara, Fergal

2006-01-01

In the soil bacterium Pseudomonas fluorescens M114, extracellular proteolytic activity and fluorescent siderophore (pseudobactin M114) production were previously shown to be co-ordinately negatively regulated in response to environmental iron levels. An iron-starvation extracytoplasmic function sigma factor, PbrA, required for the transcription of siderophore biosynthetic genes, was also implicated in M114 protease regulation. The current study centred on the characterization and genetic regulation of the gene(s) responsible for protease production in M114. A serralysin-type metalloprotease gene, aprA, was identified and found to encode the major, if not only, extracellular protease produced by this strain. The expression of aprA and its protein product were found to be subject to complex regulation. Transcription analysis confirmed that PbrA was required for full aprA transcription under low iron conditions, while the ferric uptake regulator, Fur, was implicated in aprA repression under high iron conditions. Interestingly, the iron regulation of AprA was dependent on culture conditions, with PbrA-independent AprA-mediated proteolytic activity observed on skim milk agar supplemented with yeast extract, when supplied with iron or purified pseudobactin M114. These effects were not observed on skim milk agar without yeast extract. PbrA-independent aprA expression was also observed from a truncated transcriptional fusion when grown in sucrose asparagine tryptone broth supplied with iron or purified pseudobactin M114. Thus, experimental evidence suggested that iron mediated its effects via transcriptional activation by PbrA under low iron conditions, while an as-yet-unidentified sigma factor(s) may be required for the PbrA-independent aprA expression and AprA proteolytic activity induced by siderophore and iron.

Resistin production from adipose tissue is decreased in db/db obese mice, and is reversed by rosiglitazone.

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Hongying Ye

Full Text Available OBJECTIVE: This study was designed to (1 investigate the expression profiles of resistin in db/db mice and its dynamic association with metabolic parameters; and (2 evaluate the effects of Rosiglitazone on production of resistin. METHODS: Db/db mice and their lean litter mates were used for this study. Epididymal fat tissue was excised from mice of different age (from 5 to 12 weeks for ex vivo incubation. Resistin,along with adiponectin,in serum and conditioned culture medium of epididymal fat pads were measured with immunoassays. The gene expression of resistin was determined by real-time PCR. Rosiglitazone or the vehicle (PBS was administered into db/db mice by daily intra-gastric gavage. Differentiated 3T3-L1 adipocytes were used for in vitro evaluation. RESULTS: The secretion of resistin from the fat pads in db/db mice was significantly lower than that in lean mice (P<0.01. The mRNA expression of the resistin gene in fat tissue of db/db mice at the age of 5 weeks was decreased by 60.5% compared to lean controls (p<0.05. Serum levels of resistin were comparable between the obese and lean groups, perhaps due to the increased total fat mass in db/db mice. Correlation analysis showed that serum resistin levels were positively correlated to resistin secretion from fat pads(r = 0.844,P = 0.000, while negatively associated with the body weight (r = -0.515, P = 0.000 and fasting glucose level (r = -0.357, P = 0.002. Notably, treatment with rosiglitazone increased the serum resistin levels by 66.4%(P<0.05in db/db mice. In 3T3-L1 adipocytes, Rosiglitazone (10 uM markedly enhanced the secretion of resistin by 120% (P<0.01 and its gene expression by 78.1% (P<0.05. CONCLUSION: Both resistin gene expression and its secretion from the epididymal adipose tissue were decreased in db/db obese mice, while the insulin-sensitizing drug rosiglitazone increased resistin production. Our results do not support the role of resistin as an

Chromosomally Encoded mcr-5 in Colistin non-susceptible Pseudomonas aeruginosa.

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Snesrud, Erik; Maybank, Rosslyn; Kwak, Yoon I; Jones, Anthony R; Hinkle, Mary K; Mc Gann, Patrick

2018-05-29

Whole genome sequencing (WGS) of historical Pseudomonas aeruginosa clinical isolates identified a chromosomal copy of mcr-5 within a Tn 3 -like transposon in P. aeruginosa MRSN 12280. The isolate was non-susceptible to colistin by broth microdilution and genome analysis revealed no mutations known to confer colistin resistance. To the best of our knowledge, this is the first report of mcr in colistin non-susceptible P. aeruginosa .

Effects of some organic pollutants on the exopolysaccharides (EPSs) produced by some Pseudomonas spp. strains

International Nuclear Information System (INIS)

Onbasli, Dilsad; Aslim, Belma

2009-01-01

In this study, isolation and characterization of exopolysaccharides produced by Pseudomonas aeruginosa B1, P. fluorescens B5, P. stutzeri B11 and P. putida B15 which had been seen to produce exopolymers of potential interest in biotechnological applications were examined. To initiate the observation of the organic pollutants-polymer interactions, the yield and properties of their extracellular polysaccharide were researched. The exopolysaccharide production by these strains during growth in nutrient broth medium (control) was 41-75 mg L -1 . Also, P. aeruginosa B1, P. fluorescens B5, P. stutzeri B11 and P. putida B15 had exhibited high production of EPSs in presence of various organic pollutants (2,4-D, benzene, BTX and gasoline, respectively) in mineral salt medium (MSM) as a sole carbon source. EPS production by the 4 strains ranged from 40 mg L -1 to 8 mg L -1 . Monosaccharide composition of EPS produced by these cultures were analyzed by HPLC. Results indicated that EPSs of strains contained neutral sugars and acetylated amino sugars. The neutral sugars in the EPS were mainly composed of glucose, arabinose, glycerol, ribose. The presence of galactronic acid, N-acetyl-D-galactosamin and N-acetyl-D-glucosamine indicated the acidic nature of the polysaccharide. Glycerol was the basic structural unit of EPS produced by the strains except P. stutzeri B11 (MSM with 1% BTX). Strain B1 (in NB medium) was found to be composed of neutral sugars (100%) while strain B1 [in MSM medium with 0.2% (v/v) 2.4-D] contained neutral sugars (70.0%), acetylated amino sugars (30.0%). Also, EPS content of strain B5 (in the NB medium) was neutral sugars (99.8%), acetylated amino sugars (0.2%) while the strain B5 [in MSM medium containing the 1% (v/v) benzene] was found to contain neutral sugars (99.9%), acetylated amino sugars (0.1%). However, EPS monomer composition by strain B11 was detected as neutral sugars (99.77%), acetylated amino sugars (0.23%) in NB medium while the strain B11

LONG-TERM STARVATION-INDUCED LOSS OF APPARENT ANTIBIOTIC RESISTANCE IN CELLS CONTAINING THE PLASMID PSA

Science.gov (United States)

Escherichia coli, Pseudomonas fluorescens, and a Pseudomonas sp. strain 133B containing the pSa plasmid were starved in well water for up to 523 days. There were two patterns of apparent antibiotic resistance loss observed. In Pseudomonas sp. strain 133B, there was no apparent lo...

Cloning of genes required for hypersensitivity and pathogenicity in Pseudomonas syringae pv. aptata.

Science.gov (United States)

Minardi, P

1995-01-01

A genomic library of Pseudomonas syringae pv. aptata strain NCPPB 2664, which causes bacterial blight of sugar beet, lettuce and other plants, was constructed in the cosmid vector pCPP31. The 13.4 kb EcoRI fragment of the cosmid pHIR11, containing the hrp (hypersensitive response and pathogenicity) gene cluster of the closely related bacterium Pseudomonas syringae pv. syringae strain 61, was used as a probe to identify a homologous hrp gene cluster in P. syringae pv. aptata. Thirty of 2500 cosmid clones, screened by colony hybridization, gave a strong hybridization signal with the probe, but none of these conferred to the non-pathogenic bacterium, Pseudomonas fluorescens, the ability to elicit the hypersensitive response (HR) in tobacco. Southern blot analysis of EcoRI-digested genomic DNA of P. syringae pv. aptata showed hybridizing bands of 12 kb and 4.4 kb. Only a 12 kb fragment hybridized in digests of the cosmids. Cosmid clone pCPP1069 was mutagenized with Tn10-minitet and marker-exchanged into the genome of P. syringae pv. aptata. Three resulting prototrophic mutant strains failed to elicit the HR in tobacco and to cause disease in lettuce. The DNA flanking the Tn10-minitet insertions from mutated derivatives of pCPP1069 hybridized with the 10.6 kb Bg/II fragment of pHIR11. These results indicate that P. syringae pv. aptata harbours hrp genes that are similar to, but arranged differently from, homologous hrp genes of P. syringae pv. syringae.

A quest for indigenous truffle helper prokaryotes

Czech Academy of Sciences Publication Activity Database

Gryndler, Milan; Soukupová, Lucie; Hršelová, Hana; Gryndlerová, Hana; Borovička, Jan; Streiblová, Eva; Jansa, Jan

2013-01-01

Roč. 5, č. 3 (2013), s. 346-352 ISSN 1758-2229 R&D Projects: GA ČR GAP504/10/0382 Institutional support: RVO:67985831 ; RVO:61388971 Keywords : TUBER-BORCHII * PSEUDOMONAS -FLUORESCENS * ECTOMYCORRHIZAL FUNGI Subject RIV: EE - Microbiology, Virology Impact factor: 3.264, year: 2013

Identification of copper-induced genes in Pseudomonas fluorescens and use of a reporter strain to monitor bioavailable copper in soil

DEFF Research Database (Denmark)

Tom-Petersen, Andreas; Hosbond, Carsten; Nybroe, Ole

2001-01-01

-amended soil microcosms in a concentration-dependent manner. The chelator EDTA reduced the availability of Cu to P. fluorescens in soil. This showed that complex-bound Cu is not necessarily available to bacteria, We compared chemical analysis of soluble Cu and the reporter assay on soil solutions from Cu-containing......-Cu15, the gene interrupted by the transposon encoded a protein carrying a Cu-binding domain but with low homology to known proteins. DF57-Cu15 was the most suitable Cu reporter due to its high specific response and tolerance to Cu in pure culture. DF57-Cu15 responded to soil solutions from Cu...... soil microcosms supplemented with either manure or straw. Organic matter increased the amount of soluble Cu but not the amount of bioavailable Cu. Probably, Cu binds with high affinity to organic constituents in pig manure or barley straw. Hence, determination of soluble Cu by chemical analysis cannot...

Genomics-guided discovery of secondary metabolites and their regulation in Pseudomonas protegens Pf-5

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Pseudomonas protegens strain Pf-5 is a well-characterized rhizosphere bacterium known for its production of a diverse spectrum of secondary metabolites and its capacity to suppress plant diseases caused by soilborne fungal, bacterial and oomycete pathogens. Metabolites produced by Pf-5 include 2,4-...

Far from superficial: microbial diversity associated with the skin and mucus of fish

Science.gov (United States)

Cipriano, Rocco C.; Dove, Alistair; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.

2011-01-01

During horizontal or water-borne infection involving an obligate pathogen (e.g. – Aeromonas salmonicida, cause of furunculosis), the pathogen interacted with and influenced the microbial diversity of the dermal mucus of fish. Prior to infection, the prevalent bacterial flora cultured from juvenile Atlantic salmon (Salmo salar) included Pseudomonas fluorescens, Comomonas terrigenia, Acinetobacter sp., Moraxella sp., Pseudomonas dimunita, Alcaligenes denitrificans, Pseudomonas pseudoalcaligenes, and Pseudomonas alcaligenes, Serratia liquefaciens, Aeromonas hydrophila, other motile Aeromonas spp., and Corynebacterium aquaticum. After A. salmonicida was initially detected in this population as an external mucus infection, Acinetobacter sp., Moraxella sp., C. terrigenia, P. fluorescens, and P. dimunita, Staphylococcus sp., and A. hydrophila, were also present in appreciable numbers. Within several weeks, however, the A. salmonicida infection amplified and composed 78% of the total flora in the mucus. Only P. dimunita (4%). P. fluorescens (2%), and C. terrigenia (1%) were cultured at that time and more than a third of these fish showed evidence of a systemic A. salmonicida infection within their kidneys. Eight weeks after oral oxytetracycline treatments, A. salmonicida was no longer isolated from the mucus or kidneys of any fish and glucose inert or other oxidative microbes (e.g., P. fluorescens, C. terrigenia, Acinetobacter sp., Moraxella sp.) were beginning to repopulate the external surface of the salmon in increasing frequency. Still present and composing fairly large percentages of the total flora were A. hydrophila, as well as Enterobacter sp., and P. putrefaciens. A normal microbial diversity was re-established as the fish recovered. In another investigation, reduced biological diversity was noted in the dermal mucus among smallmouth bass that were sampled from the Jackson River (Covington, VA). In these fish, A. hydrophila and P. putrefaciens were the two

[Nah-plasmids of IncP-9 group from natural strains of Pseudomonas].

Science.gov (United States)

Levchuk, A A; Bulyga, I M; Izmalkova, T Iu; Sevast'ianovich, Ia R; Kosheleva, I A; Thomas, C M; Titok, M A

2006-01-01

Use of polymerase chain reaction helped to establish that the most frequent among naphthalene utilizing bacteria, isolated on the territory of Belarus, are Nah-plasmids of IncP-9 incompatibility group and those with indefinite systematic belonging. With the help of classical test of incompatibility, restriction and sequence analyses three new subgroups within the IncP-9 group were discovered (zeta, eta and IncP-9-like replicons). Conducting of restriction analysis for amplification products of nahG and nahAc genes allowed us to reveal, in addition to known sequences of stated determinants, two new types of nahG gene. Restriction analysis performed on amplification products of 16S RNA genes (ARDRA method) showed that native hosts of Nah-plasmids of IncP-9 group are not only fluorescent bacteria from genus Pseudomonas (P. fluorescens, P. putida, P. aeruginosa, P. species), but also non-fluorescent bacteria with indefinite specific belonging.

The interplay of StyR and IHF regulates substrate-dependent induction and carbon catabolite repression of styrene catabolism genes in Pseudomonas fluorescens ST

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Leoni Livia

2008-06-01

Full Text Available Abstract Background In Pseudomonas fluorescens ST, the promoter of the styrene catabolic operon, PstyA, is induced by styrene and is subject to catabolite repression. PstyA regulation relies on the StyS/StyR two-component system and on the IHF global regulator. The phosphorylated response regulator StyR (StyR-P activates PstyA in inducing conditions when it binds to the high-affinity site STY2, located about -40 bp from the transcription start point. A cis-acting element upstream of STY2, named URE, contains a low-affinity StyR-P binding site (STY1, overlapping the IHF binding site. Deletion of the URE led to a decrease of promoter activity in inducing conditions and to a partial release of catabolite repression. This study was undertaken to assess the relative role played by IHF and StyR-P on the URE, and to clarify if PstyA catabolite repression could rely on the interplay of these regulators. Results StyR-P and IHF compete for binding to the URE region. PstyA full activity in inducing conditions is achieved when StyR-P and IHF bind to site STY2 and to the URE, respectively. Under catabolite repression conditions, StyR-P binds the STY1 site, replacing IHF at the URE region. StyR-P bound to both STY1 and STY2 sites oligomerizes, likely promoting the formation of a DNA loop that closes the promoter in a repressed conformation. We found that StyR and IHF protein levels did not change in catabolite repression conditions, implying that PstyA repression is achieved through an increase in the StyR-P/StyR ratio. Conclusion We propose a model according to which the activity of the PstyA promoter is determined by conformational changes. An open conformation is operative in inducing conditions when StyR-P is bound to STY2 site and IHF to the URE. Under catabolite repression conditions StyR-P cellular levels would increase, displacing IHF from the URE and closing the promoter in a repressed conformation. The balance between the open and the closed

Two small RNAs, CrcY and CrcZ, act in concert to sequester the Crc global regulator in Pseudomonas putida, modulating catabolite repression.

Science.gov (United States)

Moreno, Renata; Fonseca, Pilar; Rojo, Fernando

2012-01-01

The Crc protein is a translational repressor that recognizes a specific target at some mRNAs, controlling catabolite repression and co-ordinating carbon metabolism in pseudomonads. In Pseudomonas aeruginosa, the levels of free Crc protein are controlled by CrcZ, a sRNA that sequesters Crc, acting as an antagonist. We show that, in Pseudomonas putida, the levels of free Crc are controlled by CrcZ and by a novel 368 nt sRNA named CrcY. CrcZ and CrcY, which contain six potential targets for Crc, were able to bind Crc specifically in vitro. The levels of CrcZ and CrcY were low under conditions generating a strong catabolite repression, and increased strongly when catabolite repression was absent. Deletion of either crcZ or crcY had no effect on catabolite repression, but the simultaneous absence of both sRNAs led to constitutive catabolite repression that compromised growth on some carbon sources. Overproduction of CrcZ or CrcY significantly reduced repression. We propose that CrcZ and CrcY act in concert, sequestering and modulating the levels of free Crc according to metabolic conditions. The CbrA/CbrB two-component system activated crcZ transcription, but had little effect on crcY. CrcY was detected in P. putida, Pseudomonas fluorescens and Pseudomonas syringae, but not in P. aeruginosa. © 2011 Blackwell Publishing Ltd.

Complete genome sequence of Pseudomonas rhizosphaerae IH5T (=DSM 16299T), a phosphate-solubilizing rhizobacterium for bacterial biofertilizer.

Science.gov (United States)

Kwak, Yunyoung; Jung, Byung Kwon; Shin, Jae-Ho

2015-01-10

Pseudomonas rhizosphaerae IH5(T) (=DSM 16299(T)), isolated from the rhizospheric soil of grass growing in Spain, has been reported as a novel species of the genus Pseudomonas harboring insoluble phosphorus solubilizing activity. To understanding the multifunctional biofertilizer better, we report the complete genome sequence of P. rhizosphaerae IH5(T). Copyright © 2014 Elsevier B.V. All rights reserved.

PRODUCTION AND CHARACTERIZATION OF BIOSURFACTANT BY Pseudomonas fluorescens USING CASSAVA FLOUR WASTEWATER AS MEDIA

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Venty Suryanti

2013-12-01

Full Text Available Biosurfactant with efficient emulsification properties could be produced by Pseudomonas flourescens using cassava flour wastewater (manipueira as media. The ability of P. flourescens to produce biosurfactant could suggest potential use in industrial and environmental applications. Media containing a mixture of natural manipueira and nutrient broth with 48 h fermentation was the optimum condition for the biosurfactant production. Based on UV-Vis and FT-IR spectra, the biosurfactant was indicated as rhamnolipids containing hydroxyl, ester, carboxylic and aliphatic carbon chain functional groups. Biosurfactant exhibited critical micelle concentration (CMC value of 715 mg/L and reduced the surface tension of the water from 80 mN/m to 59 mN/m. The biosurfactant was able to decrease the interfacial tension about 51-70% when benzyl chloride, palm oil and kerosene were used as water-immiscible compounds. The biosurfactant was able to form stable emulsion until 30 days when paraffin, soybean oil, lubricant oil and kerosene were used as water-immiscible compounds.

Elevated Steroid Hormone Production in the db/db Mouse Model of Obesity and Type 2 Diabetes.

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Hofmann, Anja; Peitzsch, Mirko; Brunssen, Coy; Mittag, Jennifer; Jannasch, Annett; Frenzel, Annika; Brown, Nicholas; Weldon, Steven M; Eisenhofer, Graeme; Bornstein, Stefan R; Morawietz, Henning

2017-01-01

Obesity and type 2 diabetes have become a major public health problem worldwide. Steroid hormone dysfunction appears to be linked to development of obesity and type 2 diabetes and correction of steroid abnormalities may offer new approaches to therapy. We therefore analyzed plasma steroids in 15-16 week old obese and diabetic db/db mice using liquid chromatography-tandem mass spectrometry. Lean db/+ served as controls. Db/db mice developed obesity, hyperglycemia, hyperleptinemia, and hyperlipidemia. Hepatic triglyceride storage was increased and adiponectin and pancreatic insulin were lowered. Aldosterone, corticosterone, 11-deoxycorticosterone, and progesterone were respectively increased by 3.6-, 2.9-, 3.4, and 1.7-fold in db/db mice compared to controls. Ratios of aldosterone-to-progesterone and corticosterone-to-progesterone were respectively 2.0- and 1.5-fold higher in db/db mice. Genes associated with steroidogenesis were quantified in the adrenal glands and gonadal adipose tissues. In adrenals, Cyp11b2 , Cyp11b1 , Cyp21a1 , Hsd3b1 , Cyp11a1 , and StAR were all significantly increased in db/db mice compared with db/+ controls. In adipose tissue, no Cyp11b2 or Cyp11b1 transcripts were detected and no differences in Cyp21a1 , Hsd3b1 , Cyp11a1 , or StAR expression were found between db/+ and db/db mice. In conclusion, the present study showed an elevated steroid hormone production and adrenal steroidogenesis in the db/db model of obesity and type 2 diabetes. © Georg Thieme Verlag KG Stuttgart · New York.

Transcriptomic profiling of microbe-microbe interactions reveals the specific response of the biocontrol strain P. fluorescens In5 to the phytopathogen Rhizoctonia solani

DEFF Research Database (Denmark)

Hennessy, Rosanna Catherine; Glaring, Mikkel Andreas; Olsson, Stefan

2017-01-01

reads per sample. RESULTS: No significant changes in global gene expression were recorded during dual-culture of P. fluorescens In5 with any of the two pathogens but rather each pathogen appeared to induce expression of a specific set of genes. A particularly strong transcriptional response to R. solani...... and in particular the fungus R. solani. This highlights the importance of studying microbe-microbe interactions to gain a better understanding of how different systems function in vitro and ultimately in natural systems where biocontrol agents can be used for the sustainable management of plant diseases....

Protective effects of astragaloside IV on db/db mice with diabetic retinopathy.

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Yuzhi Ding

Full Text Available Diabetic retinopathy (DR is a common diabetic eye disease which is well-known as the result of microvascular retinal changes. Although the potential biological functions of astragaloside IV (AS IV have long been described in traditional system of medicine, its protective effect on DR remains unclear. This study aims to investigate the function and mechanism of AS IV on type 2 diabetic db/db mice.Db/db mice were treated with AS IV (4.5 mg/kg or 9 mg/kg or physiological saline by oral gavage for 20 weeks along with db/m mice. In each group, retinal ganglion cell (RGC function was measured by pattern electroretinogram (ERG and apoptosis was determined by Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL staining. Blood and retina aldose reductase (AR activity were quantified by chemiluminescence analysis. The expressions of phosporylated-ERK1/2, NF-κB were determined by Western blot analysis. Furthermore, the expression of related downstream proteins were quantified by Label-based Mouse Antibody Array.Administration of AS IV significantly improved the amplitude in pattern ERG and reduced the apoptosis of RGCs.in db/db mice. Furthermore, downregulation of AR activity, ERK1/2 phosphorylation, NF-κB and related cytokine were observed in AS IV treatment group.Our study indicated that AS IV, as an inhibitor of AR, could prevent the activation of ERK1/2 phosporylation and NF-kB and further relieve the RGCs disfunction in db/db mice with DR. It has provided a basis for investigating the clinical efficacy of AR inhibitors in preventing DR.

Reduction of Fusarium wilt in watermelon by Pseudomonas chlororaphis PCL1391 and P. fluorescens WCS365

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G.T. Tziros

2007-12-01

Full Text Available Fusarium wilt of watermelon (Citrullus lanatus caused by Fusarium oxysporum f. sp. niveum is a devastatine soil-borne disease that causes extensive losses throughout the world. Two known Pseudomonas biocontrol strains were used separately and in combination to assess their antagonistic effectiveness against F. oxysporum f. sp. niveum in pot experiments. P. chlororaphis PCL1391 signifi cantly reduced disease severity. P. fl uorescens WCS365 was less effective in disease suppression, while a combination of the two bacteria had intermediate effects. The biological control of Fusarium wilt with P. chlororaphis offers a potentially useful tool in an integrated pest management program to control Fusarium wilt of watermelon.

From the root to the stem: interaction between the biocontrol root endophyte Pseudomonas fluorescens PICF7 and the pathogen Pseudomonas savastanoi NCPPB 3335 in olive knots

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Maldonado-González, M Mercedes; Prieto, Pilar; Ramos, Cayo; Mercado-Blanco, Jesús

2013-01-01

Olive knot disease, caused by Pseudomonas savastanoi pv. savastanoi, is one of the most important biotic constraints for olive cultivation. Pseudomonas fluorescens PICF7, a natural colonizer of olive roots and effective biological control agent (BCA) against Verticillium wilt of olive, was examined as potential BCA against olive knot disease. Bioassays using in vitro-propagated olive plants were carried out to assess whether strain PICF7 controlled knot development either when co-inoculated with the pathogen in stems or when the BCA (in roots) and the pathogen (in stems) were spatially separated. Results showed that PICF7 was able to establish and persist in stem tissues upon artificial inoculation. While PICF7 was not able to suppress disease development, its presence transiently decreased pathogen population size, produced less necrotic tumours, and sharply altered the localization of the pathogen in the hyperplasic tissue, which may pose epidemiological consequences. Confocal laser scanning microscopy combined with fluorescent tagging of bacteria revealed that when PICF7 was absent the pathogen tended to be localized at the knot surface. However, presence of the BCA seemed to confine P. savastanoi at inner regions of the tumours. This approach has also enabled to prove that the pathogen can moved systemically beyond the hypertrophied tissue. PMID:23425069

Effectiveness of cleaning and sanitizing procedures in controlling the adherence of Pseudomonas fluorescens, Salmonella Enteritidis, and Staphylococcus aureus to domestic kitchen surfaces Eficiência dos procedimentos de limpeza e de sanitização no controle da adesão de Pseudomonas fluorescens, Salmonella Enteritidis e Staphylococcus aureus em superfícies usadas em cozinhas domésticas

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Iara Dias Silva

2010-03-01

Full Text Available The effectiveness of cleaning and sanitizing procedures in controlling Staphylococcus aureus, Salmonella Enteritidis, and Pseudomonasfluorescens adhered to granite and stainless steel was evaluated. There was no significant difference (p > 0.05 in the adherence of pure cultures of these microorganisms to stainless steel. The numbers of P. fluorescens and S. Enteritidis adhered to granite were greater (p 0.05 between the surfaces. However, a significant difference was observed (p A eficiência dos procedimentos de limpeza e sanitização no controle de Staphylococcus aureus, Salmonella Enteritidis e Pseudomonasfluorescens aderidas em granito e aço inoxidável foi avaliada. Não houve diferença significativa (p > 0,05 na adesão destes microrganismos quando em cultura pura, em aço inoxidável. O número de células aderidas de P. fluorescens e S. Enteritidis foi maior (p 0,05 entre as superfícies. Entretanto, observou-se uma diferença (p < 0,05 entre as soluções sanitizantes utilizadas. Hipoclorito de sódio e ácido peracético apresentaram maior ação bactericida (p < 0,05 que o composto de amônia quaternária. Observou-se que S. aureus apresentou menor resistência à ação desses sanitizantes. Os resultados mostram a importância da adequada realização dos procedimentos de limpeza e sanitização para evitar a adesão bacteriana e formação de biofilme.

Characterization of rhizobacteria associated to maize crop in IAA, siderophores and salicylic acid metabolite production

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Annia Hernández

2004-01-01

Full Text Available It has been demonstrated that rhizobacteria are able to produce metabolites having agricultural interest, including salicylic acid, the siderophores and phytohormones. Indol acetic acid (IAA is the most well-known and studied auxin, playing a governing role in culture growth. The object of this work was to characterise rhizobacteria associated with the maize crop in terms of producing IAA, siderophores and salicylic acid metabolites. Burkholderia cepacia and Pseudomonas fluorescens strains previously isolated from maize Francisco variety rhizosphere were used. Colorimetric and chromatographic techniques for detecting these metabolites were studied; multi-variable analysis of hierarchic conglomerate and complete ligament were used for selecting the best strains for producing metabolites of interest. These results demonstrated that all rhizobacteria strains studied produced IAA, siderophores and salicylic acid metabolites. Burkholderia cepacia MBf21, MBp1, MBp2, MBf22, MBp3, MBf20, MBf 15 and Pseudomonas fluorescens MPp4strains have presented the greatest production of these metabolites, showing that these strains could be used in promoting vegetal growth in economically important cultures. Key words: Pseudomonas fluorescens, Burkholderia cepacia, IAA, siderophore, salicylic acid.

Elimination of the formation of biofilm in industrial pipes using enzyme cleaning technique

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Xiaobo Liu

2014-01-01

Lastly, the terminal water was tested with SLYM-BART™ (HACH Corporation to find out whether there were biofilm-forming bacteria, such as Pseudomonas aeruginosa (Lakretz et al. (2011 [1], Pseudomonas fluorescens (O’Toole and Kolter (1998 [2], iron bacterium, etc.

Dicty_cDB: SLJ310 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 5' similar to Arabidopsis thaliana sequence At1g48030 lipoamide dehydrogenase precursor see http://mips... At1g48030 lipoamide dehydrogenase precursor see http://mips.gsf.de/proj/thal/db/index.html, mRNA sequence.

Bioactivities by a crude extract from the Greenlandic Pseudomonas sp. In5 involves the nonribosomal peptides, nunamycin and nunapeptin

DEFF Research Database (Denmark)

Frydenlund Michelsen, Charlotte; Jensen, Helle; Venditto, Vincent J.

2015-01-01

Bioactive microbial metabolites provide a successful source of novel compounds with pharmaceutical potentials. The bacterium Pseudomonas sp. In5 is a biocontrol strain isolated from a plant disease suppressive soil in Greenland, which produces two antimicrobial nonribosomal peptides (NRPs), nunap......), nunapeptin and nunamycin. In this study, we used in vitro antimicrobial and anticancer bioassays to evaluate the potential bioactivities of both a crude extract derived from Pseudomonas sp. In5 and NRPs purified from the crude extract....

Chemotherapy of second stage human African trypanosomiasis: comparison between the parenteral diamidine DB829 and its oral prodrug DB868 in vervet monkeys.

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John K Thuita

2015-02-01

Full Text Available Human African trypanosomiasis (HAT, sleeping sickness ranks among the most neglected tropical diseases based on limited availability of drugs that are safe and efficacious, particularly against the second stage (central nervous system [CNS] of infection. In response to this largely unmet need for new treatments, the Consortium for Parasitic Drug Development developed novel parenteral diamidines and corresponding oral prodrugs that have shown cure of a murine model of second stage HAT. As a rationale for selection of one of these compounds for further development, the pharmacokinetics and efficacy of intramuscular (IM active diamidine 2,5-bis(5-amidino-2-pyridylfuran (DB829; CPD-0802 and oral prodrug2,5-bis[5-(N-methoxyamidino-2-pyridyl]furan (DB868 were compared in the vervet monkey model of second stage HAT. Treatment was initiated 28 days post-infection of monkeys with T. b. rhodesiense KETRI 2537. Results showed that IM DB829 at 5 mg/kg/day for 5 consecutive days, 5 mg/kg/day every other day for 5 doses, or 2.5 mg/kg/day for 5 consecutive days cured all monkeys (5/5. Oral DB868 was less successful, with no cures (0/2 at 3 mg/kg/day for 10 days and cure rates of 1/4 at 10 mg/kg/day for 10 days and 20 mg/kg/day for 10 days; in total, only 2/10 monkeys were cured with DB868 dose regimens. The geometric mean plasma Cmax of IM DB829 at 5 mg/kg following the last of 5 doses was 25-fold greater than that after 10 daily oral doses of DB868 at 20 mg/kg. These data suggest that the active diamidine DB829, administered IM, should be considered for further development as a potential new treatment for second stage HAT.

Characterization of a metal resistant Pseudomonas sp. isolated from uranium mine for its potential in heavy metal (Ni2+, Co2+, Cu2+, and Cd2+) sequestration.

Science.gov (United States)

Choudhary, Sangeeta; Sar, Pinaki

2009-05-01

Heavy metal sequestration by a multimetal resistant Pseudomonas strain isolated from a uranium mine was characterized for its potential application in metal bioremediation. 16S rRNA gene analysis revealed phylogenetic relatedness of this isolate to Pseudomonas fluorescens. Metal uptake by this bacterium was monophasic, fast saturating, concentration and pH dependent with maximum loading of 1048 nmol Ni(2+) followed by 845 nmol Co(2+), 828 nmol Cu(2+) and 700 nmol Cd(2+)mg(-1) dry wt. Preferential metal deposition in cell envelope was confirmed by TEM and cell fractionation. FTIR spectroscopy and EDX analysis revealed a major role of carboxyl and phosphoryl groups along with a possible ion exchange mechanism in cation binding. Binary system demonstrated selective metal binding affinity in the order of Cu(2+)>Ni(2+)>Co(2+)>Cd(2+). A comparison with similar metal uptake reports considering live bacteria strongly indicated the superiority of this strain in metal sequestration, which could be useful for developing efficient metal removal system.

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?

Selective inhibition of Erwinia amylovora by the herbicidally active germination-arrest factor (GAF) produced by Pseudomonas bacteria.

Science.gov (United States)

Halgren, A; Azevedo, M; Mills, D; Armstrong, D; Thimmaiah, M; McPhail, K; Banowetz, G

2011-10-01

 The germination-arrest factor (GAF) produced by Pseudomonas fluorescens WH6, and identified as 4-formylaminooxyvinylglycine, specifically inhibits the germination of a wide range of grassy weeds. This study was undertaken to determine whether GAF has antimicrobial activity in addition to its inhibitory effects on grass seed germination. Culture filtrate from Ps. fluorescens WH6 had little or no effect on 17 species of bacteria grown in Petri dish lawns, but the in vitro growth of Erwinia amylovora, the causal agent of the disease of orchard crops known as fire blight, was strongly inhibited by the filtrate. The anti-Erwinia activity of WH6 culture filtrate was shown to be due to its GAF content, and a commercially available oxyvinylglycine, 4-aminoethoxyvinylglycine (AVG), exhibited anti-Erwinia activity similar to that of GAF. The effects of GAF on Erwinia were reversed by particular amino acids. The biological properties of GAF include a rather specific antimicrobial activity against Erw. amylovora. This may be a general property of oxyvinylglycines as AVG exhibited similar activity. The ability of particular amino acids to reverse GAF inhibition is consistent with a potential effect of this compound on the activity of aminotransferases. The results presented here demonstrate a novel antimicrobial activity of oxyvinylglycines and suggest that GAF and/or GAF-producing bacteria may have potential for the control of fire blight. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology. No claim to US Government works.

Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae

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Daniel P. Molloy

2013-01-01

Full Text Available In an effort to develop an efficacious and environmentally safe method for managing zebra mussels (Dreissena polymorpha and quaggamussels (Dreissena rostriformis bugensis, we initiated a research project investigating the potential use of bacteria and their naturalmetabolic products as biocontrol agents. This project resulted in the discovery of an environmental isolate lethal to dreissenid mussels,Pseudomonas fluorescens strain CL145A (Pf-CL145A. In previous published reports we have demonstrated that: 1 Pf-CL145A’s mode ofaction is intoxication (not infection; 2 natural product within ingested bacterial cells lyse digestive tract epithelial cells leading to dreisseniddeath; and 3 high dreissenid kill rates (>90% are achievable following treatment with Pf-CL145A cells, irrespective of whether thebacterial cells are dead or alive. Investigating the environmental safety of Pf-CL145A was also a key element in our research efforts, andherein, we report the results of non-target trials demonstrating Pf-CL145A’s high specificity to dreissenids. These acute toxicity trials weretypically single-dose, short-term (24-72 h exposures to Pf-CL145A cells under aerated conditions at concentrations highly lethal todreissenids (100 or 200 mg/L. These trials produced no evidence of mortality among the ciliate Colpidium colpoda, the cladoceran Daphniamagna, three fish species (Pimephales promelas, Salmo trutta, and Lepomis macrochirus, and seven bivalve species (Mytilus edulis,Pyganodon grandis, Pyganodon cataracta, Lasmigona compressa, Strophitus undulatus, Lampsilis radiata, and Elliptio complanata. Lowmortality (3-27% was recorded in the amphipod Hyalella azteca, but additional trials suggested that most, if not all, of the mortality couldbe attributed to some other unidentified factor (e.g., possibly particle load or a water quality issue rather than Pf-CL145A’s dreissenidkillingnatural product. In terms of potential environmental safety, the results of

Identification of fungal plant pathogens associated with oak (Quercus humboldtii Bonpl.), In the municipalities of Encino (Santander), Arcabuco, and Tipacoque (Boyaca)

International Nuclear Information System (INIS)

Monroy Castro, Leidi Yunari; Lizarazo Forero, Luz Marina

2010-01-01

The objectives of this study were to isolate and determine the presence of the pathogen Phytophthora ramorum and other potential pathogens of Quercus humboldtii, and evaluate the possibility of using the antagonistic capacity of bacteria isolated from rhizosphere and phyllosphere against them. The study was conducted in the conservation corridor Guantiva - La Rusia - Iguaque, in the municipalities of Encino (Santander), Arcabuco and Tipacoque (Boyaca). The phytopathogenic fungi were isolated using direct seeding of leaves with symptoms of fungal infection in OGY, Sabouraud, and PDA + Lactic acid at 0.2%. We used the plate counting technique for the isolation of bacteria from rhizospheric and bulk soil. Phytophthora ramorum was not isolated, but phytopathogenic fungi of the genus Fusarium spp., and Pestalotia spp., were obtained in the isolates. Microbial populations of rhizospheric and bulk soil were scarce, exhibited low diversity, and were dominated by few morphotypes. We identified four species of bacteria: Pseudomonas fluorescens, Bacillus macerans, Pinus sylvestris and Staphylococcus epidermidis. The phyllosphere community was dominated by Pseudomonas fluorescens. The species Pseudomonas fluorescens and Pinus sylvestris did not exhibited antagonistic properties against Pestalotia spp. Further studies are required to confirm Fusarium spp., and Pestalotia spp., pathogenic activity against Quercus humboldtii.

Efecto de la aplicación de pseudomonas fluorescentes en las propiedades físico-químicas y biológicas de suelo : balance nutricional y estimulación de hormonas

OpenAIRE

Martínez Moreno, Joaquín Ignacio

2015-01-01

El objetivo de esta propuesta es el estudio del efecto de la aplicación de un fitofortificante (bacterias, Pseudomonas fluorescens) en la evolución tanto de las propiedades físico-químicas y microbiológicas/bioquímicas del suelo como en la estimulación de hormonas del crecimiento vegetal, así como estudiar su efecto en el balance nutricional, la calidad y la producción de los cultivos de maíz y melón. Escuela Técnica superior de Ingeniería Agronómica Universidad Politécnica ...

Resistin production from adipose tissue is decreased in db/db obese mice, and is reversed by rosiglitazone.

Science.gov (United States)

Ye, Hongying; Zhang, Herbert J; Xu, Aimin; Hoo, Ruby L C

2013-01-01

This study was designed to (1) investigate the expression profiles of resistin in db/db mice and its dynamic association with metabolic parameters; and (2) evaluate the effects of Rosiglitazone on production of resistin. Db/db mice and their lean litter mates were used for this study. Epididymal fat tissue was excised from mice of different age (from 5 to 12 weeks) for ex vivo incubation. Resistin,along with adiponectin,in serum and conditioned culture medium of epididymal fat pads were measured with immunoassays. The gene expression of resistin was determined by real-time PCR. Rosiglitazone or the vehicle (PBS) was administered into db/db mice by daily intra-gastric gavage. Differentiated 3T3-L1 adipocytes were used for in vitro evaluation. The secretion of resistin from the fat pads in db/db mice was significantly lower than that in lean mice (Plean controls (plean groups, perhaps due to the increased total fat mass in db/db mice. Correlation analysis showed that serum resistin levels were positively correlated to resistin secretion from fat pads(r = 0.844,P = 0.000), while negatively associated with the body weight (r = -0.515, P = 0.000) and fasting glucose level (r = -0.357, P = 0.002). Notably, treatment with rosiglitazone increased the serum resistin levels by 66.4%(Pproduction. Our results do not support the role of resistin as an etiological link between obesity and diabetes.

Adaptive Divergence in Experimental Populations of Pseudomonas fluorescens. IV. Genetic Constraints Guide Evolutionary Trajectories in a Parallel Adaptive Radiation

OpenAIRE

McDonald, Michael J.; Gehrig, Stefanie M.; Meintjes, Peter L.; Zhang, Xue-Xian; Rainey, Paul B.

2009-01-01

The capacity for phenotypic evolution is dependent upon complex webs of functional interactions that connect genotype and phenotype. Wrinkly spreader (WS) genotypes arise repeatedly during the course of a model Pseudomonas adaptive radiation. Previous work showed that the evolution of WS variation was explained in part by spontaneous mutations in wspF, a component of the Wsp-signaling module, but also drew attention to the existence of unknown mutational causes. Here, we identify two new muta...

Impaired Muscle Regeneration in Ob/ob and Db/db Mice

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Mai-Huong Nguyen

2011-01-01

Full Text Available In obesity and type 2 diabetes, efficient skeletal muscle repair following injury may be required, not only for restoring muscle structure and function, but also for maintaining exercise capacity and insulin sensitivity. The hypothesis of this study was that muscle regeneration would be impaired in ob/ob and db/db mice, which are common mouse models of obesity and type 2 diabetes. Muscle injury was produced by cardiotoxin injection, and regeneration was assessed by morphological and immunostaining techniques. Muscle regeneration was delayed in ob/ob and db/db mice, but not in a less severe model of insulin resistance – feeding a high-fat diet to wild-type mice. Angiogenesis, cell proliferation, and myoblast accumulation were also impaired in ob/ob and db/db mice, but not the high-fat diet mice. The impairments in muscle regeneration were associated with impaired macrophage accumulation; macrophages have been shown previously to be required for efficient muscle regeneration. Impaired regeneration in ob/ob and db/db mice could be due partly to the lack of leptin signaling, since leptin is expressed both in damaged muscle and in cultured muscle cells. In summary, impaired muscle regeneration in ob/ob and db/db mice was associated with reduced macrophage accumulation, angiogenesis, and myoblast activity, and could have implications for insulin sensitivity in the skeletal muscle of obese and type 2 diabetic patients.

Phosphorylcholine Phosphatase: A Peculiar Enzyme of Pseudomonas aeruginosa

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Carlos Eduardo Domenech

2011-01-01

Full Text Available Pseudomonas aeruginosa synthesizes phosphorylcholine phosphatase (PchP when grown on choline, betaine, dimethylglycine or carnitine. In the presence of Mg2+ or Zn2+, PchP catalyzes the hydrolysis of p-nitrophenylphosphate (p-NPP or phosphorylcholine (Pcho. The regulation of pchP gene expression is under the control of GbdR and NtrC; dimethylglycine is likely the metabolite directly involved in the induction of PchP. Therefore, the regulation of choline metabolism and consequently PchP synthesis may reflect an adaptive response of P. aeruginosa to environmental conditions. Bioinformatic and biochemistry studies shown that PchP contains two sites for alkylammonium compounds (AACs: one in the catalytic site near the metal ion-phosphoester pocket, and another in an inhibitory site responsible for the binding of the alkylammonium moiety. Both sites could be close to each other and interact through the residues 42E, 43E and 82YYY84. Zn2+ is better activator than Mg2+ at pH 5.0 and it is more effective at alleviating the inhibition produced by the entry of Pcho or different AACs in the inhibitory site. We postulate that Zn2+ induces at pH 5.0 a conformational change in the active center that is communicated to the inhibitory site, producing a compact or closed structure. However, at pH 7.4, this effect is not observed because to the hydrolysis of the [Zn2+L2−1L20(H2O2] complex, which causes a change from octahedral to tetrahedral in the metal coordination geometry. This enzyme is also present in P. fluorescens, P. putida, P. syringae, and other organisms. We have recently crystallized PchP and solved its structure.

The rare codon AGA is involved in regulation of pyoluteorin biosynthesis in Pseudomonas protegens Pf-5

Science.gov (United States)

The soil bacterium Pseudomonas protegens Pf-5 can colonize root and seed surfaces of many plants, protecting them from infection by plant pathogenic fungi and oomycetes. This capacity to suppress disease is attributed in part to Pf-5’s production of a large spectrum of antibiotics, which is controll...

Rapid detection of rRNA group I pseudomonads in contaminated metalworking fluids and biofilm formation by fluorescent in situ hybridization.

Science.gov (United States)

Saha, Ratul; Donofrio, Robert S; Goeres, Darla M; Bagley, Susan T

2012-05-01

Metalworking fluids (MWFs), used in different machining operations, are highly prone to microbial degradation. Microbial communities present in MWFs lead to biofilm formation in the MWF systems, which act as a continuous source of contamination. Species of rRNA group I Pseudomonas dominate in contaminated MWFs. However, their actual distribution is typically underestimated when using standard culturing techniques as most fail to grow on the commonly used Pseudomonas Isolation Agar. To overcome this, fluorescent in situ hybridization (FISH) was used to study their abundance along with biofilm formation by two species recovered from MWFs, Pseudomonas fluorescens MWF-1 and the newly described Pseudomonas oleovorans subsp. lubricantis. Based on 16S rRNA sequences, a unique fluorescent molecular probe (Pseudo120) was designed targeting a conserved signature sequence common to all rRNA group I Pseudomonas. The specificity of the probe was evaluated using hybridization experiments with whole cells of different Pseudomonas species. The probe's sensitivity was determined to be 10(3) cells/ml. It successfully detected and enumerated the abundance and distribution of Pseudomonas indicating levels between 3.2 (± 1.1) × 10(6) and 5.0 (± 2.3) × 10(6) cells/ml in four different industrial MWF samples collected from three different locations. Biofilm formation was visualized under stagnant conditions using high and low concentrations of cells for both P. fluorescens MWF-1 and P. oleovorans subsp. lubricantis stained with methylene blue and Pseudo120. On the basis of these observations, this molecular probe can be successfully be used in the management of MWF systems to monitor the levels and biofilm formation of rRNA group I pseudomonads.

DB Energie 2020. Implementation of sustainability strategy DB2020; DB Energie 2020. Die Umsetzung der Nachhaltigkeitsstrategie DB2020

Energy Technology Data Exchange (ETDEWEB)

Witschke, Hans-Juergen [DB Energie GmbH, Frankfurt am Main (Germany)

2013-06-15

As a worldwide provider of mobility and logistics services and one of the biggest employers in Germany, Deutsche Bahn (DB) bears a special responsibility for customers, its own staff, the environment and society as a whole. In order to meet this responsibility, it has made the consistent implementation of the DB Energie 2020 sustainability concept an essential element of its business strategy. Following this line of business provides DB with good opportunities on the one hand but also carries risks and challenges on the other. (orig.)

MELCOR DB Construction for the Severe Accident Analysis DB

International Nuclear Information System (INIS)

Song, Y. M.; Ahn, K. I.

2011-01-01

The Korea Atomic Energy Research Institute (KAERI) has been constructing a severe accident analysis database (DB) under a National Nuclear R and D Program. In particular, an MAAP (commercial code being widely used in industries for integrated severe accident analysis) DB for many scenarios including a station blackout (SBO) has been completed. This paper shows the MELCOR DB construction process with examples of SBO scenarios, and the results will be used for a comparison with the MAAP DB

Influences of obese (ob/ob and diabetes (db/db genotype mutations on lumber vertebral radiological and morphometric indices: Skeletal deformation associated with dysregulated systemic glucometabolism

Directory of Open Access Journals (Sweden)

Garris David R

2006-02-01

Full Text Available Abstract Background Both diabetes and obesity syndromes are recognized to promote lumbar vertebral instability, premature osteodegeneration, exacerbate progressive osteoporosis and increase the propensity towards vertebral degeneration, instability and deformation in humans. Methods The influences of single-gene missense mutations, expressing either diabetes (db/db or obese (ob/ob metabolic syndromes on vertebral maturation and development in C57BL/KsJ mice were evaluated by radiological and macro-morphometric analysis of the resulting variances in osteodevelopment indices relative to control parameters between 8 and 16 weeks of age (syndrome onset @ 4 weeks, and the influences of low-dose 17-B-estradiol therapy on vertebral growth expression evaluated. Results Associated with the indicative genotypic obesity and hyper-glycemic/-insulinemic states, both db/db and ob/ob mutants demonstrated a significant (P ≤ 0.05 elongation of total lumbar vertebrae column (VC regional length, and individual lumbar vertebrae (LV1-5 lengths, relative to control VC and LV parameters. In contrast, LV1-5 width indices were suppressed in db/db and ob/ob mutants relative to control LV growth rates. Between 8 and 16 weeks of age, the suppressed LV1-5 width indices were sustained in both genotype mutant groups relative to control osteomaturation rates. The severity of LV1-5 width osteosuppression correlated with the severe systemic hyperglycemic and hypertriglyceridemic conditions sustained in ob/ob and db/db mutants. Low-dose 17-B-estradiol therapy (E2-HRx: 1.0 ug/ 0.1 ml oil s.c/3.5 days, initiated at 4 weeks of age (i.e., initial onset phase of db/db and ob/ob expressions re-established control LV 1–5 width indices without influencing VC or LV lengths in db/db groups. Conclusion These data demonstrate that the abnormal systemic endometabolic states associated with the expression of db/db and ob/ob genomutation syndromes suppress LV 1–5 width osteomaturation

Plant-associated fluorescent Pseudomonas from red lateritic soil: Beneficial characteristics and their impact on lettuce growth.

Science.gov (United States)

Maroniche, Guillermo A; Rubio, Esteban J; Consiglio, Adrián; Perticari, Alejandro

2016-11-25

Fluorescent Pseudomonas are ubiquitous soil bacteria that usually establish mutualistic associations with plants, promoting their growth and health by several mechanisms. This makes them interesting candidates for the development of crop bio-inoculants. In this work, we isolated phosphate-solubilizing fluorescent Pseudomonas from the rhizosphere and inner tissues of different plant species growing in red soil from Misiones, Argentina. Seven isolates displaying strong phosphate solubilization were selected for further studies. Molecular identification by rpoD genotyping indicated that they belong to different species within the P. fluorescens and P. putida phylogenetic groups. Screening for in vitro traits such as phosphate solubilization, growth regulators synthesis or degradation, motility and antagonism against phytopathogens or other bacteria, revealed a unique profile of characteristics for each strain. Their plant growth-promoting potential was assayed using lettuce as a model for inoculation under controlled and greenhouse conditions. Five of the strains increased the growth of lettuce plants. Overall, the strongest lettuce growth promoter under both conditions was strain ZME4, isolated from inner tissues of maize. No clear association between lettuce growth promotion and in vitro beneficial traits was detected. In conclusion, several phosphate solubilizing pseudomonads from red soil were isolated that display a rich array of plant growth promotion traits, thus showing a potential for the development of new inoculants.

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis.

Science.gov (United States)

Wei, Hai-Lei; Zhang, Wei; Collmer, Alan

2018-05-08

The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E) proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

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

Proteases in Plasma and Kidney of db/db Mice as Markers of Diabetes-Induced Nephropathy

Science.gov (United States)

Hadler-Olsen, E.; Winberg, J.-O.; Reinholt, F. P.; Larsen, T.; Uhlin-Hansen, L.; Jenssen, T.; Berg, E.; Kolset, S. O.

2011-01-01

Db/db mice are overweight, dyslipidemic and develop diabetic complications, relevant for similar complications in human type 2 diabetes. We have used db/db and db/+ control mice to investigate alterations in proteinase expression and activity in circulation and kidneys by SDS-PAGE zymography, electron microscopy, immunohistochemistry, Western blotting, and in situ zymography. Plasma from db/db mice contained larger amounts of serine proteinases compared to db/+ mice. Kidneys from the db/db mice had a significantly larger glomerular surface area and somewhat thicker glomerular basement membranes compared to the db/+ mice. Furthermore, kidney extracts from db/+ mice contained metalloproteinases with M r of approximately 92000, compatible with MMP-9, not observed in db/db mice. These results indicate that higher levels of serine proteinases in plasma may serve as potential markers for kidney changes in db/db mice, whereas a decrease in MMP-9 in the kidney may be related to the glomerular changes. PMID:22363890

Characterization of a marine-isolated mercury-resistant Pseudomonas putida strain SP1 and its potential application in marine mercury reduction

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weiwei; Chen, Lingxin; Liu, Dongyan [Chinese Academy of Sciences, Yantai, SD (China). Yantai Inst. of Coastal Zone Research (YICCAS); Chinese Academy of Sciences, Yantai, SD (China). Shandong Provincial Key Lab. of Coastal Zone Environmental Processes

2012-02-15

The Pseudomonas putida strain SP1 was isolated from marine environment and was found to be resistant to 280 {mu}M HgCl{sub 2}. SP1 was also highly resistant to other metals, including CdCl{sub 2}, CoCl{sub 2}, CrCl{sub 3}, CuCl{sub 2}, PbCl{sub 2}, and ZnSO{sub 4}, and the antibiotics ampicillin (Ap), kanamycin (Kn), chloramphenicol (Cm), and tetracycline (Tc). mer operon, possessed by most mercury-resistant bacteria, and other diverse types of resistant determinants were all located on the bacterial chromosome. Cold vapor atomic absorption spectrometry and a volatilization test indicated that the isolated P. putida SP1 was able to volatilize almost 100% of the total mercury it was exposed to and could potentially be used for bioremediation in marine environments. The optimal pH for the growth of P. putida SP1 in the presence of HgCl{sub 2} and the removal of HgCl{sub 2} by P. putida SP1 was between 8.0 and 9.0, whereas the optimal pH for the expression of merA, the mercuric reductase enzyme in mer operon that reduces reactive Hg{sup 2+} to volatile and relatively inert monoatomic Hg{sup 0} vapor, was around 5.0. LD50 of P. putida SP1 to flounder and turbot was 1.5 x 10{sup 9} CFU. Biofilm developed by P. putida SP1 was 1- to 3-fold lower than biofilm developed by an aquatic pathogen Pseudomonas fluorescens TSS. The results of this study indicate that P. putida SP1 is a low virulence strain that can potentially be applied in the bioremediation of HgCl{sub 2} contamination over a broad range of pH. (orig.)

Exploiting genotypic diversity of 2,4-Diacetylphloroglucinol-producing Pseudomonas spp.: characterization of superior root-colonizing P. fluorescens strain Q8r1-96

NARCIS (Netherlands)

Raaijmakers, J.M.; Weller, D.M.

2001-01-01

The genotypic diversity that occurs in natural populations of antagonistic microorganisms provides an enormous resource for improving biological control of plant diseases. In this study, we determined the diversity of indigenous 2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas spp. occurring

Bacterial Feeders, the Nematode Caenorhabditis elegans and the Flagellate Cercomonas longicauda, have different Effects on Outcome of Competition among the Pseudomonas Biocontrol Strains CHA0 and DSS73

DEFF Research Database (Denmark)

Pedersen, Annette; Nybroe, Ole; Winding, Anne

2009-01-01

How bacterial feeding fauna affects colonization and survival of bacteria in soil is not well understood, which constrains the applicability of bacterial inoculants in agriculture. This study aimed to unravel how food quality of bacteria and bacterial feeders with different feeding habits (the......50090 or one of two biocontrol strains P. fluorescens CHA0 or Pseudomonas sp. DSS73) or combinations of two bacterial strains. DSM50090 is a suitable food bacterium, DSS73 is of intermediate food quality, and CHA0 is inedible to the bacterial feeders. Bacterial and protozoan cell numbers were measured...... predation pressure. Hence, the results suggested that the outcome of competition among bacteria depended on their ability to cope with the prevailing bacterial predator....

Efecto de rizobacterias promotoras de crecimiento vegetal solubilizadoras de fosfato en Lactuca sativa cultivar White Boston

Directory of Open Access Journals (Sweden)

Diana Beatriz Sanchez López

2014-07-01

Full Text Available Título en español: Efecto de rizobacterias promotoras de crecimiento vegetal solubilizadoras de fosfato en Lactuca sativa cultivar White Boston Título en ingles: Effect of plant growth promoting rhizobacteria phosate solubilizing  Lactuca sativa cultivar White Boston Resumen:  En las últimas décadas, la agricultura colombiana se ha visto afectada por la reducción de la productividad en las zonas hortícolas, el incremento de los costos de producción y la dependencia del uso de productos químicos, produciendo un daño irreversible al medio ambiente y la calidad de vida de productores y consumidores. El objetivo de investigación fue evaluar el efecto de rizobacterias promotoras del crecimiento  vegetal del género Pseudomonas sp. sobre Lactuca sativa cultivar White Boston como solubilizadoras de roca fosfórica. El estudio se realizó en el Centro de Investigación Tibaitatá (Corpoica ubicado en Mosquera (Cundinamarca-Colombia. Los resultados demostraron que las cepas tienen la capacidad intrínseca para solubilizar fuentes de fósforo de baja solubilidad como la roca fosfórica. La aplicación de inoculantes con base en las cepas: Pseudomonas fluorescens FR1, Pseudomonas sp., UVLO27 y Pseudomonas sp. LEAV18 arrojaron los mejores resultados. Las cepas Pseudomonas sp. FR2, UVLO27 y K35, tienen la capacidad de producir índoles y sideróforos. El experimento en invernadero evidenció que las cepas Pseudomonas fluorescens FR1, Pseudomonas sp. FR2 y UVLO27 incrementaron de manera significativa (P<0.05 la biomasa y el desarrollo de las plantas. El uso de rocas fosfóricas representa una alternativa económica y ecológica viable, en sistemas de agricultura sostenible.  Palabras claves: Pseudomonas sp., Biofertilizantes, Roca fosfórica, Fósforo, Índoles totales. Abstract:  In the last decades, Colombian agriculture has been affected by the reduction in productivity in horticultural areas, increase in production costs and the dependence

Amplified fragment length polymorphism fingerprinting of Pseudomonas strains from a poultry processing plant.

Science.gov (United States)

Geornaras, I; Kunene, N F; von Holy, A; Hastings, J W

1999-09-01

Molecular typing has been used previously to identify and trace dissemination of pathogenic and spoilage bacteria associated with food processing. Amplified fragment length polymorphism (AFLP) is a novel DNA fingerprinting technique which is considered highly reproducible and has high discriminatory power. This technique was used to fingerprint 88 Pseudomonas fluorescens and Pseudomonas putida strains that were previously isolated from plate counts of carcasses at six processing stages and various equipment surfaces and environmental sources of a poultry abattoir. Clustering of the AFLP patterns revealed a high level of diversity among the strains. Six clusters (clusters I through VI) were delineated at an arbitrary Dice coefficient level of 0.65; clusters III (31 strains) and IV (28 strains) were the largest clusters. More than one-half (52.3%) of the strains obtained from carcass samples, which may have represented the resident carcass population, grouped together in cluster III. By contrast, 43.2% of the strains from most of the equipment surfaces and environmental sources grouped together in cluster IV. In most cases, the clusters in which carcass strains from processing stages grouped corresponded to the clusters in which strains from the associated equipment surfaces and/or environmental sources were found. This provided evidence that there was cross-contamination between carcasses and the abattoir environment at the DNA level. The AFLP data also showed that strains were being disseminated from the beginning to the end of the poultry processing operation, since many strains associated with carcasses at the packaging stage were members of the same clusters as strains obtained from carcasses after the defeathering stage.

Mechanical Vibration Mitigates the Decrease of Bone Quantity and Bone Quality of Leptin Receptor-Deficient Db/Db Mice by Promoting Bone Formation and Inhibiting Bone Resorption.

Science.gov (United States)

Jing, Da; Luo, Erping; Cai, Jing; Tong, Shichao; Zhai, Mingming; Shen, Guanghao; Wang, Xin; Luo, Zhuojing

2016-09-01

Leptin, a major hormonal product of adipocytes, is involved in regulating appetite and energy metabolism. Substantial studies have revealed the anabolic actions of leptin on skeletons and bone cells both in vivo and in vitro. Growing evidence has substantiated that leptin receptor-deficient db/db mice exhibit decreased bone mass and impaired bone microstructure despite several conflicting results previously reported. We herein systematically investigated bone microarchitecture, mechanical strength, bone turnover and its potential molecular mechanisms in db/db mice. More importantly, we also explored an effective approach for increasing bone mass in leptin receptor-deficient animals in an easy and noninvasive manner. Our results show that deterioration of trabecular and cortical bone microarchitecture and decreases of skeletal mechanical strength-including maximum load, yield load, stiffness, energy, tissue-level modulus and hardness-in db/db mice were significantly ameliorated by 12-week, whole-body vibration (WBV) with 0.5 g, 45 Hz via micro-computed tomography (μCT), three-point bending, and nanoindentation examinations. Serum biochemical analysis shows that WBV significantly decreased serum tartrate-resistant acid phosphatase 5b (TRACP5b) and CTx-1 levels and also mitigated the reduction of serum osteocalcin (OCN) in db/db mice. Bone histomorphometric analysis confirmed that decreased bone formation-lower mineral apposition rate, bone formation rate, and osteoblast numbers in cancellous bone-in db/db mice were suppressed by WBV. Real-time PCR assays show that WBV mitigated the reductions of tibial alkaline phosphatase (ALP), OCN, Runt-related transcription factor 2 (RUNX2), type I collagen (COL1), BMP2, Wnt3a, Lrp6, and β-catenin mRNA expression, and prevented the increases of tibial sclerostin (SOST), RANK, RANKL, RANL/osteoprotegerin (OPG) gene levels in db/db mice. Our results show that WBV promoted bone quantity and quality in db/db mice with obvious

Mastering MariaDB

CERN Document Server

Razzoli, Federico

2014-01-01

This book is intended for intermediate users who want to learn how to administrate a MariaDB server or a set of servers. It is aimed at MariaDB users, and hence working knowledge of MariaDB is a prerequisite.

Portulaca oleracea Ameliorates Diabetic Vascular Inflammation and Endothelial Dysfunction in db/db Mice

Science.gov (United States)

Lee, An Sook; Lee, Yun Jung; Lee, So Min; Yoon, Jung Joo; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

2012-01-01

Type 2 diabetes is associated with significantly accelerated rates of micro- and macrovascular complications such as diabetic vascular inflammation and endothelial dysfunction. In the present study, we investigated the protective effect of the aqueous extract of Portulaca oleracea L. (AP), an edible plant used as a folk medicine, on diabetic vascular complications. The db/db mice were treated with AP (300 mg/kg/day, p.o.) for 10 weeks, and AP treatment markedly lowered blood glucose, plasma triglyceride, plasma level of LDL-cholesterol, and systolic blood pressure in diabetic db/db mice. Furthermore, AP significantly increased plasma level of HDL-cholesterol and insulin level. The impairment of ACh- and SNP-induced vascular relaxation of aortic rings were ameliorated by AP treatment in diabetic db/db mice. This study also showed that overexpression of VCAM-1, ICAM-1, E-selectin, MMP-2, and ET-1 were observed in aortic tissues of untreated db/db mice, which were significantly suppressed by treatment with AP. We also found that the insulin immunoreactivity of the pancreatic islets remarkably increased in AP treated db/db mice compared with untreated db/db mice. Taken together, AP suppresses hyperglycemia and diabetic vascular inflammation, and prevents the development of diabetic endothelial dysfunction for the development of diabetes and its vascular complications. PMID:22474522

Biotransformations with nitrilases

Czech Academy of Sciences Publication Activity Database

Martínková, Ludmila; Křen, Vladimír

2010-01-01

Roč. 14, č. 2 (2010), s. 130-137 ISSN 1367-5931 R&D Projects: GA AV ČR IAA500200708; GA MŠk(CZ) LC06010; GA MŠk OC09046; GA MPO FT-TA5/043 Institutional research plan: CEZ:AV0Z50200510 Keywords : ENZYME-PROMOTED DESYMMETRISATION * PSEUDOMONAS-FLUORESCENS EBC191 * SUBSTRATE-SPECIFICITY Subject RIV: CE - Biochemistry Impact factor: 9.312, year: 2010

Zinc Prevents the Development of Diabetic Cardiomyopathy in db/db Mice

Directory of Open Access Journals (Sweden)

Shudong Wang

2017-03-01

Full Text Available Diabetic cardiomyopathy (DCM is highly prevalent in type 2 diabetes (T2DM patients. Zinc is an important essential trace metal, whose deficiency is associated with various chronic ailments, including vascular diseases. We assessed T2DM B6.BKS(D-Leprdb/J (db/db mice fed for six months on a normal diet containing three zinc levels (deficient, adequate, and supplemented, to explore the role of zinc in DCM development and progression. Cardiac function, reflected by ejection fraction, was significantly decreased, along with increased left ventricle mass and heart weight to tibial length ratio, in db/db mice. As a molecular cardiac hypertrophy marker, atrial natriuretic peptide levels were also significantly increased. Cardiac dysfunction and hypertrophy were accompanied by significantly increased fibrotic (elevated collagen accumulation as well as transforming growth factor β and connective tissue growth factor levels and inflammatory (enhanced expression of tumor necrosis factor alpha, interleukin-1β, caspase recruitment domain family member 9, and B-cell lymphoma/leukemia 10, and activated p38 mitogen-activated protein kinase responses in the heart. All these diabetic effects were exacerbated by zinc deficiency, and not affected by zinc supplementation, respectively. Mechanistically, oxidative stress and damage, mirrored by the accumulation of 3-nitrotyrosine and 4-hydroxy-2-nonenal, was significantly increased along with significantly decreased expression of Nrf2 and its downstream antioxidants (NQO-1 and catalase. This was also exacerbated by zinc deficiency in the db/db mouse heart. These results suggested that zinc deficiency promotes the development and progression of DCM in T2DM db/db mice. The exacerbated effects by zinc deficiency on the heart of db/db mice may be related to further suppression of Nrf2 expression and function.

Rhizospheric Microflora Escalating Aroma Constituents and Yield Attributes in Ocimum tenuiflorum (L. cv. CIM-Ayu

Directory of Open Access Journals (Sweden)

Shilpi Khare Saikia

2014-01-01

Full Text Available The exploration of rhizospheric microbial flora for crop yield enhancement is well established. Rhizospheric microbes influence the plant physiology by imparting several beneficial effects, namely, Nitrogen fixation, increased nutrient uptake, and secondary metabolites production on their host plants. The present study investigates the response of Bacillus megaterium ATCC No. 13525, Pseudomonas fluorescens ATCC No. 14581, and Trichoderma viride MTCC No. 167 in alone and combined treatments for their effect on growth and yield parameters in a commercially important Ocimum tenuiflorum L. cv. CIM-Ayu. The plant is therapeutically important for its essential oil constituents, namely, eugenol, β-caryophyllene, and various monoterpenes. The combination treatments, T7 (B. megaterium + P. fluorescens and T8 (B. megaterium + P. fluorescens + T. viride, showed maximum enhancement (27.27% of percentage essential oil as compared to untreated control. Nutrient uptake especially N2 content was significantly increased (43% with the treatment T8 (B. megaterium + P. fluorescens + T. viride. Amongst major essential oil constituents, eugenol content was maximally increased by 58.5% as compared to 42.9% (control indicating a cumulative role of microbial inoculants for crop yield boost-up.

Proteinase production in Pseudomonas fluorescens ON2 is affected by carbon sources and allows surface-attached but not planktonic cells to utilize protein for growth in lake water

DEFF Research Database (Denmark)

Nicolaisen, Mette Haubjerg; Worm, Jakob; Jørgensen, Niels O. G.

2012-01-01

-colonies were able to utilize this resource, while planktonic cells were not. Our experiments are the first to experimentally support models predicting that production of extra-cellular enzymes in dilute environments may be a waste of resources, whereas it represents a favorable feeding strategy in organic...... and there was no evidence for cell density-regulated or starvation-induced proteinase production. Proteinase was produced in the absence of an organic nitrogen source, and citrate had a negative while glucose had a positive effect on the production. Hence P. fluorescens ON2 seems to exploit protein sources by expressing...

Theoretical predictions of properties and gas-phase chromatography behaviour of bromides of group-5 elements Nb, Ta, and element 105, Db.

Science.gov (United States)

Pershina, V; Anton, J

2012-01-21

Fully relativistic, four-component density functional theory electronic structure calculations were performed for MBr(5), MOBr(3), MBr(6)(-), KMBr(6), and MBr(5)Cl(-) of group-5 elements Nb, Ta, and element 105, Db, with the aim to predict adsorption behaviour of the bromides in gas-phase chromatography experiments. It was shown that in the atmosphere of HBr/BBr(3), the pentabromides are rather stable, and their stability should increase in the row Nb Ta > Db. This sequence is in agreement with the one observed in the "one-atom-at-a-time" chromatography experiments. Some other scenarios, such as surface oxide formation were also considered but found to be irrelevant. © 2012 American Institute of Physics

Ultrasonographic Characterization of the db/db Mouse: An Animal Model of Metabolic Abnormalities

Directory of Open Access Journals (Sweden)

Francesco Faita

2018-01-01

Full Text Available The availability of an animal model able to reliably mirror organ damage occurring in metabolic diseases is an urgent need. These models, mostly rodents, have not been fully characterized in terms of cardiovascular, renal, and hepatic ultrasound parameters, and only sparse values can be found in literature. Aim of this paper is to provide a detailed, noninvasive description of the heart, vessels, liver, and kidneys of the db/db mouse by ultrasound imaging. Sixteen wild type and thirty-four db/db male mice (11-week-old were studied. State-of-the-art ultrasound technology was used to acquire images of cardiovascular, renal, and hepatic districts. A set of parameters describing function of the selected organs was evaluated. db/db mice are characterized by systolic and diastolic dysfunction, confirmed by strain analysis. Abdominal aortic and carotid stiffness do not seem to be increased in diabetic rodents; furthermore, they are characterized by a smaller mean diameter for both vessels. Renal microcirculation is significantly compromised, while liver steatosis is only slightly higher in db/db mice than in controls. We offer here for the first time an in vivo detailed ultrasonographic characterization of the db/db mouse, providing a useful tool for a thoughtful choice of the right rodent model for any experimental design.

Serotonin- and Dopamine-Related Gene Expression in db/db Mice Islets and in MIN6 β-Cells Treated with Palmitate and Oleate

Directory of Open Access Journals (Sweden)

L. R. Cataldo

2016-01-01

Full Text Available High circulating nonesterified fatty acids (NEFAs concentration, often reported in diabetes, leads to impaired glucose-stimulated insulin secretion (GSIS through not yet well-defined mechanisms. Serotonin and dopamine might contribute to NEFA-dependent β-cell dysfunction, since extracellular signal of these monoamines decreases GSIS. Moreover, palmitate-treated β-cells may enhance the expression of the serotonin receptor Htr2c, affecting insulin secretion. Additionally, the expression of monoamine-oxidase type B (Maob seems to be lower in islets from humans and mice with diabetes compared to nondiabetic islets, which may lead to increased monoamine concentrations. We assessed the expression of serotonin- and dopamine-related genes in islets from db/db and wild-type (WT mice. In addition, the effect of palmitate and oleate on the expression of such genes, 5HT content, and GSIS in MIN6 β-cell was determined. Lower Maob expression was found in islets from db/db versus WT mice and in MIN6 β-cells in response to palmitate and oleate treatment compared to vehicle. Reduced 5HT content and impaired GSIS in response to palmitate (−25%; p<0.0001 and oleate (−43%; p<0.0001 were detected in MIN6 β-cells. In conclusion, known defects of GSIS in islets from db/db mice and MIN6 β-cells treated with NEFAs are accompanied by reduced Maob expression and reduced 5HT content.

Indigenous Pseudomonas spp. Strains from the Olive (Olea europaea L.) Rhizosphere as Effective Biocontrol Agents against Verticillium dahliae: From the Host Roots to the Bacterial Genomes

Science.gov (United States)

Gómez-Lama Cabanás, Carmen; Legarda, Garikoitz; Ruano-Rosa, David; Pizarro-Tobías, Paloma; Valverde-Corredor, Antonio; Niqui, José L.; Triviño, Juan C.; Roca, Amalia; Mercado-Blanco, Jesús

2018-01-01

The use of biological control agents (BCA), alone or in combination with other management measures, has gained attention over the past decades, driven by the need to seek for sustainable and eco-friendly alternatives to confront plant pathogens. The rhizosphere of olive (Olea europaea L.) plants is a source of bacteria with potential as biocontrol tools against Verticillium wilt of olive (VWO) caused by Verticillium dahliae Kleb. A collection of bacterial isolates from healthy nursery-produced olive (cultivar Picual, susceptible to VWO) plants was generated based on morphological, biochemical and metabolic characteristics, chemical sensitivities, and on their in vitro antagonistic activity against several olive pathogens. Three strains (PIC25, PIC105, and PICF141) showing high in vitro inhibition ability of pathogens' growth, particularly against V. dahliae, were eventually selected. Their effectiveness against VWO caused by the defoliating pathotype of V. dahliae was also demonstrated, strain PICF141 being the rhizobacteria showing the best performance as BCA. Genotypic and phenotypic traits traditionally associated with plant growth promotion and/or biocontrol abilities were evaluated as well (e.g., phytase, xylanase, catalase, cellulase, chitinase, glucanase activities, and siderophore and HCN production). Multi-locus sequence analyses of conserved genes enabled the identification of these strains as Pseudomonas spp. Strain PICF141 was affiliated to the “Pseudomonas mandelii subgroup,” within the “Pseudomonas fluorescens group,” Pseudomonas lini being the closest species. Strains PIC25 and PIC105 were affiliated to the “Pseudomonas aeruginosa group,” Pseudomonas indica being the closest relative. Moreover, we identified P. indica (PIC105) for the first time as a BCA. Genome sequencing and in silico analyses allowed the identification of traits commonly associated with plant-bacteria interactions. Finally, the root colonization ability of these olive

Co-metabolic formation of substituted phenylacetic acids by styrene-degrading bacteria

Directory of Open Access Journals (Sweden)

Michel Oelschlägel

2015-06-01

The styrene-degrading strains Rhodococcus opacus 1CP, Pseudomonas fluorescens ST, and the novel isolates Sphingopyxis sp. Kp5.2 and Gordonia sp. CWB2 were investigated with respect to their applicability to co-metabolically produce substituted phenylacetic acids. Isolates were found to differ significantly in substrate tolerance and biotransformation yields. Especially, P. fluorescens ST was identified as a promising candidate for the production of several phenylacetic acids. The biotransformation of 4-chlorostyrene with cells of strain ST was shown to be stable over a period of more than 200 days and yielded about 38 mmolproduct gcelldryweight−1 after nearly 350 days. Moreover, 4-chloro-α-methylstyrene was predominantly converted to the (S-enantiomer of the acid with 40% enantiomeric excess.

Dicty_cDB: Contig-U16444-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 001503 |pid:none) Burkholderia glumae BGR1 chromos... 130 5e-30 AF511570_1( AF511570 |pid:none) Uncultured soil...) Pseudomonas syringae pv. phaseo... 80 2e-13 AF511571_1( AF511571 |pid:none) Uncultured soil bacterium clon...00390 |pid:none) Mesorhizobium sp. BNC1, complete... 57 3e-09 AF511572_1( AF511572 |pid:none) Uncultured soil

Interaction of the psychrotroph Pseudomonas fluorescens In5 with phytopathogens in cold soils

DEFF Research Database (Denmark)

Hennessy, Rosanna Catherine; Olsson, Stefan; Stougaard, Peter

Aim: Potato cultivation in southwest Greenland, at Inneruulalik, omits the use of pesticides while relying on limited crop rotations and despite the presence of plant pathogens in the soil does not suffer from major disease outbreaks. Previously, we have shown that the soil at Inneruulalik...... growth phase and upon physical encounter with fungal hyphae. Furthermore, the regulator is strongly upregulated in response to carbon sources indicating the presence of a fungus suggesting that environmental elicitors may also influence regulator expression, which upon activation controls nunamycin...... temperatures could lead to increased problems with soil-borne pathogens and importantly the application of synthetic fungicides in cold areas may be problematic due to slow degradation. Thus, the application of environmentally friendly biological control agents may provide an alternative sustainable solution...

Instant InnoDB

CERN Document Server

Reid, Matt

2013-01-01

This book is a complete reference guide, designed to provide you with answers and solutions to all the common problems you encounter within InnoDB, helping you achieve higher performance and greater stability in your InnoDB databases.The ""InnoDB Quick Reference Guide"" features content for all skill levels of MySQL administrators, developers, and engineers.

Pyoverdine synthesis by the Mn(II-oxidizing bacterium Pseudomonas putida GB-1

Directory of Open Access Journals (Sweden)

Dorothy Lundquist Parker

2014-05-01

Full Text Available When iron-starved, the Mn(II-oxidizing bacteria Pseudomonas putida strains GB-1 and MnB1 produce pyoverdines (PVDGB-1 and PVDMnB1, siderophores that both influence iron uptake and inhibit manganese(II oxidation by these strains. To explore the properties and genetics of a PVD that can affect manganese oxidation, LC-MS/MS and various siderotyping techniques were used to identify the peptides of PVDGB-1 and PVDMnB1 as being (for both PVDs: chromophore-Asp-Lys-OHAsp-Ser-Gly-aThr-Lys-cOHOrn, resembling a structure previously reported for P. putida CFML 90-51, which does not oxidize Mn. All three strains also produced an azotobactin and a sulfonated PVD, each with the peptide sequence above, but with unknown regulatory or metabolic effects. Bioinformatic analysis of the sequenced genome of P. putida GB-1 suggested that a particular non-ribosomal peptide synthetase, coded by the operon PputGB1_4083-4086, could produce the peptide backbone of PVDGB-1. To verify this prediction, plasmid integration disruption of PputGB1_4083 was performed and the resulting mutant failed to produce detectable PVD. In silico analysis of the modules in PputGB1_4083-4086 predicted a peptide sequence of Asp-Lys-Asp-Ser-Ala-Thr-Lsy-Orn, which closely matches the peptide determined by MS/MS. To extend these studies to other organisms, various Mn(II-oxidizing and non-oxidizing isolates of P. putida, P. fluorescens, P. marincola, P. fluorescens-syringae group, P. mendocina-resinovorans group and P. stutzerii group were screened for PVD synthesis. The PVD producers (12 out of 16 tested strains were siderotyped and placed into four sets of differing PVD structures, some corresponding to previously characterized PVDs and some to novel PVDs. These results combined with previous studies suggested that the presence of OHAsp or the flexibility of the pyoverdine polypeptide may enable efficient binding of Mn(III.

Pyoverdine synthesis by the Mn(II)-oxidizing bacterium Pseudomonas putida GB-1

Science.gov (United States)

Parker, Dorothy L.; Lee, Sung-Woo; Geszvain, Kati; Davis, Richard E.; Gruffaz, Christelle; Meyer, Jean-Marie; Torpey, Justin W.; Tebo, Bradley M.

2014-01-01

When iron-starved, the Mn(II)-oxidizing bacteria Pseudomonas putida strains GB-1 and MnB1 produce pyoverdines (PVDGB-1 and PVDMnB1), siderophores that both influence iron uptake and inhibit manganese(II) oxidation by these strains. To explore the properties and genetics of a PVD that can affect manganese oxidation, LC-MS/MS, and various siderotyping techniques were used to identify the peptides of PVDGB-1 and PVDMnB1 as being (for both PVDs): chromophore-Asp-Lys-OHAsp-Ser-Gly-aThr-Lys-cOHOrn, resembling a structure previously reported for P. putida CFML 90-51, which does not oxidize Mn. All three strains also produced an azotobactin and a sulfonated PVD, each with the peptide sequence above, but with unknown regulatory or metabolic effects. Bioinformatic analysis of the sequenced genome of P. putida GB-1 suggested that a particular non-ribosomal peptide synthetase (NRPS), coded by the operon PputGB1_4083-4086, could produce the peptide backbone of PVDGB-1. To verify this prediction, plasmid integration disruption of PputGB1_4083 was performed and the resulting mutant failed to produce detectable PVD. In silico analysis of the modules in PputGB1_4083-4086 predicted a peptide sequence of Asp-Lys-Asp-Ser-Ala-Thr-Lsy-Orn, which closely matches the peptide determined by MS/MS. To extend these studies to other organisms, various Mn(II)-oxidizing and non-oxidizing isolates of P. putida, P. fluorescens, P. marincola, P. fluorescens-syringae group, P. mendocina-resinovorans group, and P. stutzerii group were screened for PVD synthesis. The PVD producers (12 out of 16 tested strains) were siderotyped and placed into four sets of differing PVD structures, some corresponding to previously characterized PVDs and some to novel PVDs. These results combined with previous studies suggested that the presence of OHAsp or the flexibility of the pyoverdine polypeptide may enable efficient binding of Mn(III). PMID:24847318

Successful strategy for the selection of new strawberry-associated rhizobacteria antagonistic to Verticillium wilt.

Science.gov (United States)

Berg, G; Kurze, S; Buchner, A; Wellington, E M; Smalla, K

2000-12-01

In order to isolate and characterize new strawberry-associated bacteria antagonistic to the soil-borne pathogenic fungus Verticillium dahliae Kleb., rhizobacterial populations from two different strawberry species, Greenish Strawberry (Fragaria viridis) and Garden Strawberry (F. x ananassa) obtained after plating onto King's B and glycerol-arginine agar, were screened for in vitro antagonism toward V. dahliae. The proportion of isolates with antifungal activity determined in in vitro assay against V. dahliae was higher for the Garden Strawberry than for the Greenish Strawberry. From 300 isolates, 20 isolates with strong antifungal activity were selected characterized by physiological profiling and molecular fingerprinting methods. Diversity among the isolates was characterized with molecular fingerprints using amplified ribosomal DNA restriction analysis (ARDRA) and the more discriminating BOX-PCR fingerprint method. The physiological profiles were well correlated with molecular fingerprinting pattern analysis. Significant reduction of Verticillium wilt by bacterial dipping bath treatment was shown in the greenhouse and in fields naturally infested by V. dahliae. The relative increase of yield ranged from 117% (Streptomyces albidoflavus S1) to 344% (Pseudomonas fluorescens P10) in greenhouse trials, and 113% (Streptomyces albidoflavus S1) to 247% (Pseudomonas fluorescens P6) in field trials. Evaluation resulted in the selection of three effective biocontrol agents (Pseudomonas fluorescens P6, P10, and Streptomyces diastatochromogenes S9) antagonistic to the Verticillium wilt pathogen.

Antifouling coatings via plasma polymerization and atom transfer radical polymerization on thin film composite membranes for reverse osmosis

Science.gov (United States)

Hirsch, Ulrike; Ruehl, Marco; Teuscher, Nico; Heilmann, Andreas

2018-04-01

A major drawback to otherwise highly efficient membrane-based desalination techniques like reverse osmosis (RO) is the susceptibility of the membranes to biofouling. In this work, a combination of plasma activation, plasma bromination and surface-initiated atom transfer radical polymerization (si-ATRP) of hydrophilic and zwitterionic monomers, namely hydroxyethyl methacrylate (HEMA), 2-methacryloyloxyethyl phosphorylcholine (MPC) and [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA), was applied to generate non-specific, anti-adhesive coatings on thin film composite (TFC) membranes. The antifouling effect of the coatings was shown by short-time batch as well as long-time steady state cultivation experiments with the microorganism Pseudomonas fluorescens. It could be shown that plasma functionalization and polymerization is possible on delicate thin film composite membranes without restricting their filtration performance. All modified membranes showed an increased resistance towards the adhesion of Pseudomonas fluorescens. On average, the biofilm coverage was reduced by 51.4-12.6% (for HEMA, SBMA, and MPC), the highest reduction was monitored for MPC with a biofilm reduction by 85.4%. The hydrophilic coatings applied did not only suppress the adhesion of Pseudomonas fluorescens, but also significantly increase the permeate flux of the membranes relative to uncoated membranes. The stability of the coatings was however not ideal and will have to be improved for future commercial use.

Continuous measurements of nitrous oxide isotopomers during incubation experiments

DEFF Research Database (Denmark)

Winther, Malte Nordmann; Balslev-Harder, David; Christensen, Søren

2016-01-01

relevant for studies of atmospheric chemistry. We present results from continuous incubation experiments with denitrifying bacteria, Pseudomonas fluorescens (producing and reducing N2O) and P. chlororaphis (only producing N2O). The continuous position dependent measurements reveal the transient pattern....... fluorescens, the calculations results in SP values of −5.7 ‰ ± 5.6 during production of N2O and 2.3 ‰ ± 3.2 during reduction of N2O. In summary, we implemented continuous measurements of N2O isotopomers during incubation of denitrifying bacteria and believe that similar experiments will lead to a better...... understanding of denitrifying bacteria and N2O turnover in soils and sediments and ultimately hands-on knowledge on the biotic mechanisms behind greenhouse gas exchange of the Globe....

Development of an online biosensor for in situ monitoring of chlorine dioxide gas disinfection efficacy

Energy Technology Data Exchange (ETDEWEB)

Del Busto-Ramos, M.; Budzik, M.; Corvalan, C.; Morgan, M.; Nivens, D.; Applegate, B. [Purdue Univ., West Lafayette, IN (United States). Dept. of Food Science; Turco, R. [Purdue Univ., West Lafayette, IN (United States). Dept. of Agronomy

2008-03-15

A prototype bioluminescence-based biosensor was designed and constructed to evaluate the antimicrobial efficacy of chlorine dioxide (ClO{sub 2}) gas under various treatment conditions. The biosensor consisted of a bioluminescent bioreporter (Pseudomonas fluorescens 5RL), an optical transducer (photomultiplier tube), and a light-tight chamber housing, the bioreporter and the transducer. The bioluminescent recombinant P. fluorescens 5RL in the biosensor allowed for online monitoring of bioluminescence during ClO{sub 2} gas disinfection. Experiments were performed to evaluate the effects of the two key physical parameters associated with ClO{sub 2} disinfection: relative humidity (40, 60, 80%) and ClO{sub 2} gas concentration (0.5, 1.0, 1.6, 2.1 mg/l) on the bioreporter. Results showed that increasing concentrations of ClO{sub 2} gas corresponded to a faster decrease in luminescence. The rates of luminescence decrease from P. fluorescens 5RL, and the log reduction time (LRT, time required to obtain 1-log reduction in luminescence) were calculated for each treatment tested. The LRT values of luminescence were 103, 78, 53, and 35 s for 0.5, 1.0, 1.6, and 2.1 mg/l of ClO{sub 2} gas treatment, respectively, at 78% relative humidity. The gas concentration which caused a tenfold change in LRT (z value) for luminescence of P. fluorescens 5RL was 3.4 mg/l of ClO{sub 2}. The prototype biosensor showed potential for many applications, such as monitoring real-time microbial inactivation and understanding parameters that influence the efficacy of gaseous decontamination procedures. (orig.)

InterProScan Result: DB674426 [KAIKOcDNA[Archive

Lifescience Database Archive (English)

Full Text Available DB674426 DB674426_4_ORF1 4B0C8A5F848582EF PFAM PF04683 Proteasom_Rpn13 NA ? IPR006773 unintegrated Cellular... Component: nucleus (GO:0005634)|Cellular Component: cytoplasm (GO:0005737) ...

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis

Directory of Open Access Journals (Sweden)

Hai-Lei Wei

2018-05-01

Full Text Available Summary: The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. : Wei et al. used a Pseudomonas syringae strain lacking all known type III effectors with a modularized library expressing the 29 active effectors in the strain’s native repertoire, individually and in pairs, to comprehensively determine effector actions and interplay in inducing and suppressing responses associated with plant pathogenesis and immunity. Keywords: effector-triggered-immunity, pattern-triggered-immunity, Hop proteins, plant immunity, mini-Tn7

MongoDB high availability

CERN Document Server

Mehrabani, Afshin

2014-01-01

This book has a perfect balance of concepts and their practical implementation along with solutions to make a highly available MongoDB server with clear instructions and guidance. If you are using MongoDB in a production environment and need a solution to make a highly available MongoDB server, this book is ideal for you. Familiarity with MongoDB is expected so that you understand the content of this book.

CLONING AND CHARACTERIZATION OF A CHROMOSOMAL DNA REGION REQUIRED FOR GROWTH ON 2,4,5-T BY PSEUDOMONAS CEPACIA AC1100

Science.gov (United States)

A series of spontaneous 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) nonmetabolizing mutants of Pseudomonas cepacia AC1100 were characterized to be defective in either 2,4,5-T uptake or conversion of this compound to 2,4,5-trichlorophenol (2,4,5-TCP). Two of these mutants, RHC22 a...

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

OpenAIRE

Liu, Hsien Yueh; Chung, Chih-Yao; Yang, Wen-Chin; Liang, Chih-Lung; Wang, Chi-Young; Chang, Chih-Yu; Chang, Cicero Lee-Tian

2012-01-01

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macroph...

Basalt aquifer identification, correlation and sampling activities. History of Wells DB-8, DB-9, DB-10 and DB-11

International Nuclear Information System (INIS)

Webster, C.T.

1979-07-01

Research core wells have been completed to assist in the characterization of the groundwater regime of the upper confined aquifers found within the basalts of the Hanford Site. These wells were drilled on the Hanford Site for the Long-Term Transuranic Defense Waste Program. They were constructed to assure the Department of Energy that waste management operations will not provide an avenue for offsite migration of radionuclides. This second report details results of confined aquifer drilling activities. The purpose of this report is to document the drilling history of the wells by presenting as-built well construction diagrams and tables listing hole history data, coring records and bit records. Four wells were cored to a maximum depth of 1100 feet and water samples were taken from selected confined aquifers. Full depth was reached on all wells and core recovery was 94% of all formations drilled. Well DB-8 was abandoned after a well screen was destroyed while setting it in the well. Two wells, DB-9 and DB-10 were screened in the Mabton interbed and water was produced from this interval in both wells. Well DB-11 was used to explore for artesian water from the Priest Rapids flow unit on the western edge of the Hanford Site. The water was found at a depth of 1045 feet and now produces makeup water for all Hanford drilling

Efficacy of Acetylshikonin in Preventing Obesity and Hepatic Steatosis in db/db Mice

Directory of Open Access Journals (Sweden)

Mei-Ling Su

2016-07-01

Full Text Available Zicao (Lithospermum erythrorhizon has been used in clinics as a traditional Chinese medicine for thousands of years. Acetylshikonin (AS is the main ingredient of Zicao, Xinjiang, China. The objective of this study was to investigate the anti-obesity and anti-nonalcoholic fatty liver disease (NAFLD efficacy of AS in a model of spontaneous obese db/db mice. Mice were divided into Wild Type (WT groups and db/db groups, which received no treatment or treatment with 100 mg/kg/day clenbuterol (CL hydrochloride or 540 mg/kg/day AS by oral gavage for eight weeks. The results provided the evidence that AS prevented obesity and NAFLD including reduction in body weight, food efficiency ratio, serum triglyceride (TG and free fatty acid (FFA levels in db/db mice. Administration of AS markedly suppressed the levels of hepatic alanine aminotransferase (ALT, aspartate aminotransferase (AST and pro-inflammatory cytokines in treated groups when compared with that of db/db groups. Further investigation of the lipid synthesis-related protein using Western blotting revealed that hepatic protein expression of sterol regulatory element-binding protein-1 (SREBP-1, fatty acid synthetase (FAS and 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR were significantly downregulated by AS treatment. These findings suggest that AS exerts anti-obesity and anti-NAFLD effects through the regulation of lipid metabolism and anti-inflammatory effects.

EFFECT OF REFINED PETROLEUM PRODUCTS CONTAMINATION ON BACTERIAL POPULATION AND PHYSICOCHEMICAL CHARACTERISTICS OF CULTIVATED AGRICULTURAL SOIL

Directory of Open Access Journals (Sweden)

Adewale Sogo Olalemi

2012-10-01

Full Text Available An investigation into the effect of refined petroleum products contamination on bacterial population and physicochemical characteristics of cultivated agricultural soil was carried out. The soil samples obtained from the Teaching and Research Farm, Obakekere, Federal University of Technology, Akure, Ondo State were contaminated with varying volumes of petrol, diesel and kerosene. The results revealed higher bacterial populations in uncontaminated soils than contaminated soils. The counts of bacteria ranged from 3.0 × 105 to 5.0 × 105 cfu/g in uncontaminated soils and 1.0 × 105 to 3.0 × 105 cfu/g in contaminated soils. The isolated bacteria were identified as Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, Corynebacterium variabilis, Pseudomonas fluorescens. The contamination had no significant effect on pH, potassium, sodium, organic carbon and nitrogen content of the soils, while the moisture, calcium, phosphorus and magnesium content of the contaminated soils were significantly different (P < 0.05 compared with the uncontaminated soils. The ability of Bacillus subtilis, Flavobacterium lutescens, Micrococcus luteus, and Pseudomonas fluorescens to utilize the refined petroleum products suggest that these bacteria had potential to bioremediate petroleum contaminated soils.

Effect of Pseudomonas sp. MT5 baths on Flavobacterium columnare infection of rainbow trout and on microbial diversity on fish skin and gills.

Science.gov (United States)

Suomalainen, L R; Tiirola, M A; Valtonen, E T

2005-01-25

Use of Pseudomonas sp. strain MT5 to prevent and treat Flavobacterium columnare infection was studied in 2 experiments with fingerling rainbow trout Oncorhynchus mykiss. In the first experiment, length heterogeneity analysis of PCR-amplified DNA fragments (LH-PCR) was used to assess the effect of antagonistic baths on the microbial diversity of healthy and experimentally infected fish. In the 148 samples studied, no difference was found between bathed and unbathed fish, and 3 fragment lengths were detected most frequently: 500 (in 75.7% of the samples), 523 (62.2%) and 517 bp (40.5%). The species contributing to these fragment sizes were Pseudomonas sp., Rhodococcus sp. and F. columnare, respectively. A specific PCR for detection of Pseudomonas sp. MT5 was designed, but none of the tissue samples were found to be positive, most likely indicating poor adhesion of the strain during bathing. LH-PCR was found to be a more powerful tool for detecting F. columnare in fish tissue than traditional culture methods (chi2 = 3.9, df = 1, p < 0.05). Antagonistic baths had no effect on the outbreak of infection or on fish mortality. F. columnare was also detected in healthy fish prior to and after experimental infection, indicating that these fish were carriers of the disease. In the second experiment, intensive Pseudomonas sp. MT5 antagonistic baths were given daily to rainbow trout suffering from a natural columnaris infection. Again, the antagonistic bacteria had no effect on fish mortality, which reached 95 % in both control and antagonist-treated groups in 7 d.

Bio-protective microbial agents from rhizosphere eco-systems trigger plant defense responses provide protection against sheath blight disease in rice (Oryza sativa L.).

Science.gov (United States)

Singh, Udai B; Malviya, Deepti; Wasiullah; Singh, Shailendra; Pradhan, Jatindra K; Singh, Bhanu P; Roy, Manish; Imram, Mohd; Pathak, Neelam; Baisyal, B M; Rai, Jai P; Sarma, B K; Singh, Rajiv K; Sharma, P K; Kaur, Saman Deep; Manna, M C; Sharma, Sushil K; Sharma, Arun K

2016-11-01

Sheath blight of rice (Oryza sativa L.) caused by Rhizoctonia solani is a major disease and attempts are being made to develop microbe based technologies for biocontrol of this pathogen. However, the mechanisms of biocontrol are not fully understood and still require indepth study in the backdrop of emerging concepts in biological systems. The present investigation was aimed at deciphering the mechanisms of biocontrol of sheath blight of rice employing Pseudomonas fluorescens and Trichoderma harzianum as model agents for biocontrol. Initially 25, 5 and 5 strains of P. fluorescens, T. viride and T. harzianum, respectively, were screened for their biocontrol potential. Out of which, six strains with higher value of percent inhibition of fungal mycelium in dual plate assay were selected. The role of P. fluorescens, T. viride and T. harzianum were investigated in induction and bioaccumulation of natural antioxidants, defence-related biomolecules and other changes in plant which lead not only to growth promotion but also protection from pathogenic stress conditions in rice. The two most promising strains, P. fluorescens PF-08 and T. harzianum UBSTH-501 selected on the basis of in planta evaluation, when applied individually or in combination, significantly enhanced the accumulation of defence-related biomolecules, enzymes and exhibited biocontrol potential against R. solani. A modified/newly developed delivery system was applied for the first time in the experiments involving inoculation of plants with both bioagents, viz. P. fluorescens PF-08 and T. harzianum UBSTH-501. Results suggested that application of P. fluorescens PF-08 and T. harzianum UBSTH-501 alone or in combination, not only helps in control of the disease but also increases plant growth along with reduction in application of toxic chemical pesticides. Copyright © 2016 Elsevier GmbH. All rights reserved.

Alkannin Inhibited Hepatic Inflammation in Diabetic Db/Db Mice

Directory of Open Access Journals (Sweden)

Wenhua Xue

2018-03-01

Full Text Available Background/Aims: The current study was designed to investigate the protective role of alkannin (ALK on liver injury in diabetic C57BL/KsJ-db/db mice and explore its potential mechanisms. Methods: An oral glucose tolerance test (OGTT was performed. The levels of insulin, alanine aminotransferase (ALT, aspartate aminotransaminase (AST, total cholesterol (TC and triglyceride (TG were determined by commercial kits. The pro-inflammatory cytokines interleukin (IL-1β, IL-6 and tumour necrosis factor (TNF-α were determined by ELISA. The levels of the ROCK/NF-κB pathway were determined by Western blotting. Results: The contents of pro-inflammatory cytokines interleukin (IL-1β, IL-6 and tumour necrosis factor (TNF-α were inhibited by ALK, metformin or fasudil in diabetic db/db mice. Further, Western blotting analysis showed that the expression of Rho, ROCK1, ROCK2, p-NF-κBp65, and p-IκBα was significantly reversed by ALK treatment. In human hepatic HepG2 cells, the hepatoprotective effects of ALK were further characterized. With response to palmitic acid-challenge, increased amounts of insulin, ALT, AST, TG, and TC were observed, whereas ALK pretreatment significantly inhibited their leakage in HepG2 cells without appreciable cytotoxic effects. The inflammation condition was recovered with ALK treatment as shown by changes of IL-1β, IL-6 and TNF-α. Further, Western blotting analysis also suggested that ALK improves hepatic inflammation in a Rho-kinase pathway. Conclusion: The present study successfully investigated the role of Rho-kinase signalling in diabetic liver injury. ALK exhibited hepatoprotective effects in diabetic db/db mice, and it might act through improving hepatic inflammation through the Rho-kinase pathway.

Weed-Suppressive Soil Bacteria to Reduce Cheatgrass and Improve Vegetation Diversity on ITD Rights-of-Way

Science.gov (United States)

2017-06-01

Transportation departments are challenged by the invasion of downy brome (cheatgrass) and medusahead. The reduction of downy brome (cheat grass) by Weed Suppressive Bacteria (WSB) Pseudomonas fluorescens strain ACK55 was evaluated on roadsides of I-8...

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

Science.gov (United States)

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

Switching catalysis from hydrolysis to perhydrolysis in P. fluorescens esterase

Science.gov (United States)

Yin, De Lu (Tyler); Bernhardt, Peter; Morley, Krista L.; Jiang, Yun; Cheeseman, Jeremy D.; Purpero, Vincent; Schrag, Joseph D.; Kazlauskas, Romas J.

2010-01-01

Many serine hydrolases catalyze perhydrolysis – the reversible formation of per-acids from carboxylic acids and hydrogen peroxide. Recently we showed that a single amino acid substitution in the alcohol binding pocket - L29P - in Pseudomonas fluorescens (SIK WI) aryl esterase (PFE) increased the specificity constant of PFE for peracetic acid formation >100-fold [Bernhardt et al. Angew. Chem. Intl. Ed. 2005, 44, 2742]. In this paper, we extend this work to address the three following questions. First, what is the molecular basis of the increase in perhydrolysis activity? We previously proposed that the L29P substitution creates a hydrogen bond between the enzyme and hydrogen peroxide in the transition state. Here we report two x-ray structures of L29P PFE that support this proposal. Both structures show a main chain carbonyl oxygen closer to the active-site serine as expected. One structure further shows acetate in the active site in an orientation consistent with reaction by an acyl-enzyme mechanism. We also detected an acyl-enzyme intermediate in the hydrolysis of ε-caprolactone by mass spectrometry. Second, can we further increase perhydrolysis activity? We discovered that the reverse reaction – hydrolysis of peracetic acid to acetic acid and hydrogen peroxide – occurs at nearly the diffusion limited rate. Since the reverse reaction cannot increase further, neither can the forward reaction. Consistent with this prediction, two variants with additional amino acid substitutions showed two fold higher kcat, but Km also increased so the specificity constant, kcat/Km, remained similar. Third, how does the L29P substitution change the esterase activity? Ester hydrolysis decreased for most esters (75-fold for ethyl acetate), but not for methyl esters. In contrast, L29P PFE catalyzed hydrolysis of ε-caprolactone five times more efficiently than wild-type PFE. Molecular modeling suggests that moving the carbonyl group closer to the active site blocks access for

African Journal of Biotechnology - Vol 11, No 101 (2012)

African Journals Online (AJOL)

Protection of melon plants against Cucumber mosaic virus infection using Pseudomonas fluorescens biofertilizer · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Rakib A Al-Ani, Mustafa A Adhab, 16579-16585 ...

Microbial degradation of phosmet on blueberry fruit and in aqueous systems by indigenous bacterial flora on lowbush blueberries (Vaccinium angustifolium).

Science.gov (United States)

Crowe, K M; Bushway, A A; Bushway, R J; Davis-Dentici, K

2007-10-01

Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant-microorganism relationship, which is essential to determination of phosmet persistence under pre- and postharvest conditions.

Scaling CouchDB

CERN Document Server

Holt, Bradley

2011-01-01

This practical guide offers a short course on scaling CouchDB to meet the capacity needs of your distributed application. Through a series of scenario-based examples, this book lets you explore several methods for creating a system that can accommodate growth and meet expected demand. In the process, you learn about several tools that can help you with replication, load balancing, clustering, and load testing and monitoring. Apply performance tips for tuning your databaseReplicate data, using Futon and CouchDB's RESTful interfaceDistribute CouchDB's workload through load balancingLearn option

Combined use of different Gfp reporters for monitoring single-cell activities of a genetically modified PCB degrader in the rhizosphere of alfalfa

DEFF Research Database (Denmark)

Boldt, T.S.; Sørensen, J.; Karlsson, U.

2004-01-01

Single-cell localization and activity of Pseudomonas,fluorescens F113, colonizing alfalfa roots, were monitored using fusions of the Escherichia coli rrnBP1 ribosomal promoter and gfp genes encoding green fluorescent protein (Gfp) of different stability. The monitoring systems permitted non...... of chlorinated biphenyl was constructed, using another gfp fusion with the meta-pathway Pin promoter from Pseudomonas putida (TOL plasmid). Expression of this promoter, which is strongly induced by the PCB-2 degradation product, 3-chlorobenzoate, was tested in vitro and subsequently monitored in vivo on alfalfa...... roots using the P. fluorescens F113rifpcb reporter. A small but distinct fraction of the introduced bacteria activated the Pm promoter and thus appeared to sense a PCB-2 degradation product in the alfalfa rhizosphere. The degrading cells, which by design were identical to the sensing cells, were located...

Perivascular adipose tissue control of insulin-induced vasoreactivity in muscle is impaired in db/db mice

DEFF Research Database (Denmark)

Meijer, Rick I; Bakker, Wineke; Alta, Caro-Lynn A F

2013-01-01

in muscle, the underlying mechanisms, and how obesity disturbs this vasodilation. Insulin-induced vasoreactivity of resistance arteries was studied with PVAT from C57BL/6 or db/db mice. PVAT weight in muscle was higher in db/db mice compared with C57BL/6 mice. PVAT from C57BL/6 mice uncovered insulin......-induced vasodilation; this vasodilation was abrogated with PVAT from db/db mice. Blocking adiponectin abolished the vasodilator effect of insulin in the presence of C57BL/6 PVAT, and adiponectin secretion was lower in db/db PVAT. To investigate this interaction further, resistance arteries of AMPKa2(+/+) and AMPKa2......-induced vasodilation in an adiponectin-dependent manner. In conclusion, PVAT controls insulin-induced vasoreactivity in the muscle microcirculation through secretion of adiponectin and subsequent AMPKa2 signaling. PVAT from obese mice inhibits insulin-induced vasodilation, which can be restored by inhibition of JNK....

XMetDB

DEFF Research Database (Denmark)

Spjuth, Ola; Rydberg, Patrik; Willighagen, Egon L

2016-01-01

Xenobiotic metabolism is an active research topic but the limited amount of openly available high-quality biotransformation data constrains predictive modeling. Current database often default to commonly available information: which enzyme metabolizes a compound, but neither experimental conditions...... nor the atoms that undergo metabolization are captured. We present XMetDB, an open access database for drugs and other xenobiotics and their respective metabolites. The database contains chemical structures of xenobiotic biotransformations with substrate atoms annotated as reaction centra...... is also available. The database is open for data deposition, and a curation scheme is in place for quality control. An extensive guide on how to enter experimental data into is available from the XMetDB wiki. XMetDB formalizes how biotransformation data should be reported, and the openly available...

High-speed electro-optic switch with -80 dB crosstalk

Science.gov (United States)

Pan, J. J.; Su, W. H.; Xu, J. Y.; Grove, C. H.

1992-01-01

Special device modeling, design and layout, and precision processing controls were employed to fabricate new balanced-bridge 2x2 and 4x4 switches on X-cut, Y-propagation LiNbO3 substrate using Ti indiffused optical waveguides. The best of these devices achieved extinction ratio and crosstalk isolation of better than 93 dB electrically (46.5 dB optically). The new switches demonstrate good reproducibility with electrical crosstalk less than -80 dB.

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.

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.

An integrated approach for the reduction of aflatoxin contamination in chilli (Capsicum annuum L.).

Science.gov (United States)

Sudha, S; Naik, M K; Ajithkumar, K

2013-02-01

An integrated approach for management of aflatoxin contamination in chilli was undertaken by evaluating the fungicides, bioagents and plant extracts against Aspergillus flavus under both in vitro and field condition. Maximum inhibition of radial growth (91.1%) was observed with 0.3% mancozeb followed by captan (85.2%). Carbendazim (73%) was effective and superior over other systemic fungicides. A complete inhibition (100%) of A. flavus was observed in neem seed kernel extract (NSKE), nimbicidin and pongamia oil at 5%. An indigenous Pseudomonas fluorescens bioagent isolate inhibited (74.9%) the growth of A. flavus over Trichoderma harzianum (70.4%). The superior performing fungicides, plant extracts and bioagents identified under in vitro were used for challenge inoculation on chilli fruits and so also for field evaluation. The captan treated fruits recorded the least infection of A. flavus (1.6%) followed by P. fluorescens (2.0%), NSKE (2.2%) and nimbicidin treated fruits (7.8%) as against control (38.3%). As regards to field evaluation, the least incidence was recorded in NSKE sprayed chilli plot (1.6%) and was on par with captan (2.2%), P. fluorescens (2.4%) and T. harzianum (2.6%) compared to control (7.4%). Hence, a pre-harvest spray of NSKE (5%) or mancozeb (0.3%) or P. fluorescens (1 × 10(8) cfu/ml) 10 days before harvest of chilli is recommended for field level management of aflatoxin.

Synergistic interaction in simultaneous exposure to Streptomyces californicus and Stachybotrys chartarum

DEFF Research Database (Denmark)

Huttunen, K.; Pelkonen, J.; Nielsen, Kristian Fog

2004-01-01

chartarum, Bacillus cereus, Mycobacterium terrae, and Pseudomonas fluorescens) alone and together with the actinomycete Streptomyces californicus. The production of nitric oxide, levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6), and cytotoxicity were...

In Situ/On-Site Biodegradation of Refined Oils and Fuels (A Technology Review). Volume 2. Appendix A. Supplementary Text.

Science.gov (United States)

1992-06-01

Naphthalene oxidation predominates in the order Mucorales , which includes species of Cunninghamella, Syncephalastrum, and Mucor (Cerniglia, Hebert, Szaniszlo...naphthal inicum nonl quifaciciens, Pseudomonas desmo 1yticum, P. fluorescens, P. putida biotype B)" ~seudomonas oleovoransg, P. put da ’v, ( Mucorales

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

Directory of Open Access Journals (Sweden)

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.

Dicty_cDB: Contig-U16414-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available ( CB282081 ) BT0047 Blomia tropicalis cDNA library Blomia trop... 52 9e-19 4 ( EX370580 ) GQ03219.B7_O07 GQ032 - Shoot ti...on of useful proteins deri... 72 1e-29 5 ( DR930447 ) EST1121986 Aquilegia cDNA library...63 ) EST1191412 Aquilegia cDNA library Aquilegia formo... 88 5e-26 2 ( DB657321 ) Saccharomyces cere... 64 1e-21 4 ( DT739515 ) EST1173364 Aquilegia cDNA library Aquilegia formo... 70 1e-21 3 ( CF609239 ) INFIO01_000017 Grape Inflore... ( DT733254 ) EST1167104 Aquilegia cDNA library Aquilegia formo... 68 8e-21 5 ( FF717444 ) XABT35772.fwd Gateway compati

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

Inhibiting the NLRP3 Inflammasome Activation with MCC950 Ameliorates Diabetic Encephalopathy in db/db Mice

Directory of Open Access Journals (Sweden)

Yadong Zhai

2018-02-01

Full Text Available Diabetes is associated with a high risk of developing cognitive dysfunction and neuropsychiatric disabilities, and these disease symptomsare termed diabetic encephalopathy (DEP. Inflammation is involved in the development of DEP. The cleavage and maturation of the proinflammatory cytokine interleukin (IL-1β is regulated by the NLRP3 inflammasome. Obese and type 2 diabetic db/db mice show anxiety- and depression-like behaviors and cognitive disorders associated with hippocampal inflammation. The purpose of this study was to explore the role of NLRP3 inflammasome in DEP. Results showed that expression levels of inflammasome components including NLRP3, apoptosis-associated speck-like protein (ASC, and caspase-1, as well as IL-1β in the hippocampus of diabetic db/db mice were higher than those of non-diabetic db/m mice. Treatment of db/db mice with NLRP3 inflammasome inhibitor MCC950 ameliorated anxiety- and depression-like behaviors as well as cognitive dysfunction, and reversed increased NLRP3, ASC, and IL-1βexpression levels and caspase-1 activity in hippocampus. Moreover, MCC950 treatment significantly improved insulin sensitivity in db/db mice. These results demonstrate that inhibition of NLRP3 inflammasome activation may prove to be a potential therapeutic approach for DEP treatment.

Draft Genome Sequence of Pseudomonas sp. Strain In5 Isolated from a Greenlandic Disease Suppressive Soil with Potent Antimicrobial Activity

DEFF Research Database (Denmark)

Hennessy, Rosanna C.; Glaring, Mikkel Andreas; Frydenlund Michelsen, Charlotte

2015-01-01

Pseudomonas sp. In5 is an isolate of disease suppressive soil with potent activity against pathogens. Its antifungal activity has been linked to a gene cluster encoding nonribosomal peptide synthetases producing the peptides nunamycin and nunapeptin. The genome sequence will provide insight into ...

Gamma-ray decontamination of sodium lauryl-ethoxy-sulfate (SLES): microbiological and physicochemical aspects

International Nuclear Information System (INIS)

Lorelli, C. H.; Curzio, O. A.; Horak, Celina I.; Fernandez Gianotti, Tomas; Kairiyama, Eulogia

1999-01-01

Sodium Lauryl-Ethoxy-Sulfate (SLES) is used as a tensioactive in several cleaning and cosmetic products. The paper describes the irradiation tests carried out to decontaminate SLES. The results demonstrate that: 1) 60 Co gamma irradiation of SLES reduces the content of Pseudomona aeroginosa and Pseudomona fluorescens to the levels required by commercial specification; 2) The irradiation with doses u p to 200 Gy does not modify the tensioactive properties of the products. (author)

Evaluation of antibacterial properties of some medicinal plants used in Iran.

Science.gov (United States)

Bonjar, Shahidi

2004-10-01

Forty-five species of 29 plant families used in the traditional medicine by Iranian people, showed antibacterial activities against one or more of the bacterial species: Bacillus cereus, Bacillus pumilus, Bordetella bronchiseptica, Escherichia coli, Klebsiella pneumoniae, Micrococcus luteus, Pseudomonas aeruginosa, Pseudomonas fluorescens, Serratia marcescens, Staphylococcus aureus and Staphylococcus epidermidis. No plant showed activity against Serratia marcescens; Bordetella bronchiseptica being the most susceptible species. All extracts showed the same activity 18 months later.

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 ).

Scaling MongoDB

CERN Document Server

Chodorow, Kristina

2011-01-01

Create a MongoDB cluster that will to grow to meet the needs of your application. With this short and concise book, you'll get guidelines for setting up and using clusters to store a large volume of data, and learn how to access the data efficiently. In the process, you'll understand how to make your application work with a distributed database system. Scaling MongoDB will help you: Set up a MongoDB cluster through shardingWork with a cluster to query and update dataOperate, monitor, and backup your clusterPlan your application to deal with outages By following the advice in this book, you'l

RavenDB high performance

CERN Document Server

Ritchie, Brian

2013-01-01

RavenDB High Performance is comprehensive yet concise tutorial that developers can use to.This book is for developers & software architects who are designing systems in order to achieve high performance right from the start. A basic understanding of RavenDB is recommended, but not required. While the book focuses on advanced topics, it does not assume that the reader has a great deal of prior knowledge of working with RavenDB.

Rapid prey evolution can alter the structure of predator-prey communities

NARCIS (Netherlands)

Friman, V. -P.; Jousset, A.; Buckling, A.

Although microevolution has been shown to play an important role in pairwise antagonistic species interactions, its importance in more complex communities has received little attention. Here, we used two Pseudomonas fluorescens prey bacterial strains (SBW25 and F113) and Tetrahymena thermophila

Effect of elevated oxygen and carbon dioxide on the surface growth of vegetable-associated micro-organisms

NARCIS (Netherlands)

Amanatidou, A.; Smid, E.J.; Gorris, L.G.M.

1999-01-01

The impact of a novel type of Modified Atmosphere (MA), referred to as high O2-MA, on micro-organisms associated with the spoilage of minimally-processed vegetables was studied. Pure cultures of Pseudomonas fluorescens, Enterobacter agglomerans, Aureobacterium strain 27, Candida guilliermondii, C.

ProteomicsDB.

Science.gov (United States)

Schmidt, Tobias; Samaras, Patroklos; Frejno, Martin; Gessulat, Siegfried; Barnert, Maximilian; Kienegger, Harald; Krcmar, Helmut; Schlegl, Judith; Ehrlich, Hans-Christian; Aiche, Stephan; Kuster, Bernhard; Wilhelm, Mathias

2018-01-04

ProteomicsDB (https://www.ProteomicsDB.org) is a protein-centric in-memory database for the exploration of large collections of quantitative mass spectrometry-based proteomics data. ProteomicsDB was first released in 2014 to enable the interactive exploration of the first draft of the human proteome. To date, it contains quantitative data from 78 projects totalling over 19k LC-MS/MS experiments. A standardized analysis pipeline enables comparisons between multiple datasets to facilitate the exploration of protein expression across hundreds of tissues, body fluids and cell lines. We recently extended the data model to enable the storage and integrated visualization of other quantitative omics data. This includes transcriptomics data from e.g. NCBI GEO, protein-protein interaction information from STRING, functional annotations from KEGG, drug-sensitivity/selectivity data from several public sources and reference mass spectra from the ProteomeTools project. The extended functionality transforms ProteomicsDB into a multi-purpose resource connecting quantification and meta-data for each protein. The rich user interface helps researchers to navigate all data sources in either a protein-centric or multi-protein-centric manner. Several options are available to download data manually, while our application programming interface enables accessing quantitative data systematically. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Impairment of the vascular relaxation and differential expression of caveolin-1 of the aorta of diabetic +db/+db mice.

Science.gov (United States)

Lam, Tze Yan; Seto, Sai Wang; Lau, Yee Man; Au, Lai Shan; Kwan, Yiu Wa; Ngai, Sai Ming; Tsui, Kwong Wing

2006-09-28

In this study, we compared the endothelium-dependent and -independent relaxation of the isolated thoracic aorta of control (+db/+m) and diabetic (+db/+db) (C57BL/KsJ) mice. The gene expression (mRNA and protein) level of the muscarinic M(3) receptors, endothelial nitric oxide synthase (eNOS) and caveolin-1 of the aorta was also evaluated. Acetylcholine caused a concentration-dependent, N(G)-nitro-L-arginine methyl-ester (20 microM)-sensitive relaxation, with approximately 100% relaxation at 10 microM, in +db/+m mice. In +db/+db mice, the acetylcholine-induced relaxation was significantly smaller (maximum relaxation: approximately 80%). The sodium nitroprusside-mediated relaxation was slightly diminished in +db/+db mice, compared to +db/+m mice. However, there was no significant difference in the isoprenaline- and cromakalim-induced relaxation observed in both species. The mRNA and protein expression levels of caveolin-1 were significantly higher in the aorta of +db/+db mice. In contrast, there was no difference in the mRNA and protein expression levels of eNOS and muscarinic M(3) receptors between these mice. Our results demonstrate that the impairment of the acetylcholine-induced, endothelium-dependent aortic relaxation observed in +db/+db mice was probably associated with an enhanced expression of caveolin-1 mRNA and protein.

Biological Control to Protect Watermelon Blossoms and Seed from Infection by Acidovorax avenae subsp. citrulli.

Science.gov (United States)

Fessehaie, A; Walcott, R R

2005-04-01

ABSTRACT The efficacy of biological control seed treatments with Pseudomonas fluorescens (A506), Acidovorax avenae subsp. avenae (AAA 99-2), and an unidentified gram-positive bacterium recovered from watermelon seed (WS-1) was evaluated for the management of bacterial fruit blotch (BFB) of watermelon. In growth chamber and greenhouse experiments, seed treated with AAA 99-2 displayed superior disease suppression, reducing BFB transmission by 96.5%. AAA 99-2, P. fluorescens A506, and Kocide also suppressed the epiphytic growth of A. avenae subsp. citrulli when applied to attached watermelon blossoms 5 h prior to inoculation. Watermelon blossom protection reduced seed infestation by A. avenae subsp. citrulli. From blossoms treated with 0.1 M phosphate buffered saline (PBS), 63% of the resulting seed lots were infested with A. avenae subsp. citrulli. In contrast, for blossoms protected with WS-1, Kocide, P. fluorescens A506, and AAA 99-2, the proportion of infested seed lots were 48.3, 21.1, 24.1, and 13.8%, respectively. The effect of blossom treatments on seed lot infestation was statistically significant (P = 0.001) but WS-1 was not significantly different from PBS. These findings suggest that blossom protection with biological control agents could be a feasible option for managing BFB.

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 ).

ProOpDB: Prokaryotic Operon DataBase.

Science.gov (United States)

Taboada, Blanca; Ciria, Ricardo; Martinez-Guerrero, Cristian E; Merino, Enrique

2012-01-01

The Prokaryotic Operon DataBase (ProOpDB, http://operons.ibt.unam.mx/OperonPredictor) constitutes one of the most precise and complete repositories of operon predictions now available. Using our novel and highly accurate operon identification algorithm, we have predicted the operon structures of more than 1200 prokaryotic genomes. ProOpDB offers diverse alternatives by which a set of operon predictions can be retrieved including: (i) organism name, (ii) metabolic pathways, as defined by the KEGG database, (iii) gene orthology, as defined by the COG database, (iv) conserved protein domains, as defined by the Pfam database, (v) reference gene and (vi) reference operon, among others. In order to limit the operon output to non-redundant organisms, ProOpDB offers an efficient method to select the most representative organisms based on a precompiled phylogenetic distances matrix. In addition, the ProOpDB operon predictions are used directly as the input data of our Gene Context Tool to visualize their genomic context and retrieve the sequence of their corresponding 5' regulatory regions, as well as the nucleotide or amino acid sequences of their genes.

High-fat, carbohydrate-free diet markedly aggravates obesity but prevents beta-cell loss and diabetes in the obese, diabetes-susceptible db/db strain.

Science.gov (United States)

Mirhashemi, Farshad; Kluth, Oliver; Scherneck, Stephan; Vogel, Heike; Kluge, Reinhart; Schurmann, Annette; Joost, Hans-Georg; Neschen, Susanne

2008-01-01

We have previously reported that a high-fat, carbohydrate-free diet prevents diabetes and beta-cell destruction in the New Zealand Obese (NZO) mouse strain. Here we investigated the effect of diets with and without carbohydrates on obesity and development of beta-cell failure in a second mouse model of type 2 diabetes, the db/db mouse. When kept on a carbohydrate-containing standard (SD; with (w/w) 5.1, 58.3, and 17.6% fat, carbohydrates and protein, respectively) or high-fat diet (HFD; 14.6, 46.7 and 17.1%), db/db mice developed severe diabetes (blood glucose >20 mmol/l, weight loss, polydipsia and polyurea) associated with a selective loss of pancreatic beta-cells, reduced GLUT2 expression in the remaining beta-cells, and reduced plasma insulin levels. In contrast, db/db mice kept on a high-fat, carbohydrate-free diet (CFD; with 30.2 and 26.4% (w/w) fat or protein) did not develop diabetes and exhibited near-normal, hyperplastic islets in spite of a morbid obesity (fat content >60%) associated with hyperinsulinaemia. These data indicate that in genetically different mouse models of obesity-associated diabetes, obesity and dietary fat are not sufficient, and dietary carbohydrates are required, for beta-cell destruction.

DBA2J db/db mice are susceptible to early albuminuria and glomerulosclerosis that correlate with systemic insulin resistance.

Science.gov (United States)

Østergaard, Mette V; Pinto, Vanda; Stevenson, Kirsty; Worm, Jesper; Fink, Lisbeth N; Coward, Richard J M

2017-02-01

Diabetic nephropathy (DN) is the leading cause of kidney failure in the world. To understand important mechanisms underlying this condition, and to develop new therapies, good animal models are required. In mouse models of type 1 diabetes, the DBA/2J strain has been shown to be more susceptible to develop kidney disease than other common strains. We hypothesized this would also be the case in type 2 diabetes. We studied db/db and wild-type (wt) DBA/2J mice and compared these with the db/db BLKS/J mouse, which is currently the most widely used type 2 DN model. Mice were analyzed from age 6 to 12 wk for systemic insulin resistance, albuminuria, and glomerular histopathological and ultrastructural changes. Body weight and nonfasted blood glucose were increased by 8 wk in both genders, while systemic insulin resistance commenced by 6 wk in female and 8 wk in male db/db DBA/2J mice. The urinary albumin-to-creatinine ratio (ACR) was closely linked to systemic insulin resistance in both sexes and was increased ~50-fold by 12 wk of age in the db/db DBA/2J cohort. Glomerulosclerosis, foot process effacement, and glomerular basement membrane thickening were observed at 12 wk of age in db/db DBA/2J mice. Compared with db/db BLKS/J mice, db/db DBA/2J mice had significantly increased levels of urinary ACR, but similar glomerular histopathological and ultrastructural changes. The db/db DBA/2J mouse is a robust model of early-stage albuminuric DN, and its levels of albuminuria correlate closely with systemic insulin resistance. This mouse model will be helpful in defining early mechanisms of DN and ultimately the development of novel therapies. Copyright © 2017 the American Physiological Society.

Reactive oxygen species and hormone signaling cascades in endophytic bacterium induced essential oil accumulation in Atractylodes lancea.

Science.gov (United States)

Zhou, Jia-Yu; Li, Xia; Zhao, Dan; Deng-Wang, Meng-Yao; Dai, Chuan-Chao

2016-09-01

Pseudomonas fluorescens induces gibberellin and ethylene signaling via hydrogen peroxide in planta . Ethylene activates abscisic acid signaling. Hormones increase sesquiterpenoid biosynthesis gene expression and enzyme activity, inducing essential oil accumulation. Atractylodes lancea is a famous Chinese medicinal plant, whose main active components are essential oils. Wild A. lancea has become endangered due to habitat destruction and over-exploitation. Although cultivation can ensure production of the medicinal material, the essential oil content in cultivated A. lancea is significantly lower than that in the wild herb. The application of microbes as elicitors has become an effective strategy to increase essential oil accumulation in cultivated A. lancea. Our previous study identified an endophytic bacterium, Pseudomonas fluorescens ALEB7B, which can increase essential oil accumulation in A. lancea more efficiently than other endophytes; however, the underlying mechanisms remain unknown (Physiol Plantarum 153:30-42, 2015; Appl Environ Microb 82:1577-1585, 2016). This study demonstrates that P. fluorescens ALEB7B firstly induces hydrogen peroxide (H2O2) signaling in A. lancea, which then simultaneously activates gibberellin (GA) and ethylene (ET) signaling. Subsequently, ET activates abscisic acid (ABA) signaling. GA and ABA signaling increase expression of HMGR and DXR, which encode key enzymes involved in sesquiterpenoid biosynthesis, leading to increased levels of the corresponding enzymes and then an accumulation of essential oils. Specific reactive oxygen species and hormone signaling cascades induced by P. fluorescens ALEB7B may contribute to high-efficiency essential oil accumulation in A. lancea. Illustrating the regulation mechanisms underlying P. fluorescens ALEB7B-induced essential oil accumulation not only provides the theoretical basis for the inducible synthesis of terpenoids in many medicinal plants, but also further reveals the complex and diverse

EFEITO DO ÁCIDO LÁTICO E DA RADIAÇÃO GAMA NA ELIMINAÇÃO DE Pseudomonas spp. E NA PRODUÇÃO DE AMÔNIA EM PEITO DE FRANGO DESOSSADO RESFRIADO

Directory of Open Access Journals (Sweden)

H. C. S. ANTUNEZ

2009-01-01

Full Text Available

Avaliou-se o efeito de diferentes concentrações de ácido lático e doses de radiação gama, bem como o efeito de suas interações, na eliminação de Pseudomonas spp. e nas concentrações de amônia, em peito de frango desossado e sem pele. As amostras foram inoculadas com 106UFC.g-1 de Pseudomonas fluorescens ATCC 13525, imersas em soluções de ácido lático nas concentrações 1,0, 1,5 e 2,0% (v/v, embaladas em polietileno permeável ao oxigênio, processadas por radiação gama, utilizando 60Co nas doses 1,5, 2,5 e 3,5KGy, e armazenadas sob refrigeração (4ºC. Estabeleceu-se, também, a correlação entre as contagens de Pseudomonas spp. (logUFC.g-1 e as concentrações de amônia (mg.100g-1, determinadas pelo método colorimétrico de Nessler, no 5º, 12º, 19º e 26º dias de armazenamento. Houve diferença significativa (p<0,05, para eliminação de Pseudomonas spp., no fator dose de radiação de 2,5KGy, enquanto o uso isolado do ácido lático, nas três concentrações utilizadas, promoveu somente reduções inferiores a um ciclo log nas contagens iniciais desse microrganismo. Todos os tratamentos resultaram em níveis de amônia inferiores ao do controle (2,8mg.100g-1. A interação entre a dose de 3,5KGy e ácido lático a 1,5% (v/v, resultou no menor nível de amônia obtido e que foi igual a 1,1mg.100g-1. O coeficiente de correlação (r = 0,8752 obtido, entre as contagens de Pseudomonas spp. e as concentrações de amônia, demonstra a viabilidade de uso do método químico para estabelecer, de forma simples e rápida, o grau de deterioração de peito de frango durante o armazenamento aeróbio refrigerado.

Bile acid sequestration reduces plasma glucose levels in db/db mice by increasing its metabolic clearance rate.

Directory of Open Access Journals (Sweden)

Maxi Meissner

Full Text Available AIMS/HYPOTHESIS: Bile acid sequestrants (BAS reduce plasma glucose levels in type II diabetics and in murine models of diabetes but the mechanism herein is unknown. We hypothesized that sequestrant-induced changes in hepatic glucose metabolism would underlie reduced plasma glucose levels. Therefore, in vivo glucose metabolism was assessed in db/db mice on and off BAS using tracer methodology. METHODS: Lean and diabetic db/db mice were treated with 2% (wt/wt in diet Colesevelam HCl (BAS for 2 weeks. Parameters of in vivo glucose metabolism were assessed by infusing [U-(13C]-glucose, [2-(13C]-glycerol, [1-(2H]-galactose and paracetamol for 6 hours, followed by mass isotopologue distribution analysis, and related to metabolic parameters as well as gene expression patterns. RESULTS: Compared to lean mice, db/db mice displayed an almost 3-fold lower metabolic clearance rate of glucose (p = 0.0001, a ∼300% increased glucokinase flux (p = 0.001 and a ∼200% increased total hepatic glucose production rate (p = 0.0002. BAS treatment increased glucose metabolic clearance rate by ∼37% but had no effects on glucokinase flux nor total hepatic or endogenous glucose production. Strikingly, BAS-treated db/db mice displayed reduced long-chain acylcarnitine content in skeletal muscle (p = 0.0317 but not in liver (p = 0.189. Unexpectedly, BAS treatment increased hepatic FGF21 mRNA expression 2-fold in lean mice (p = 0.030 and 3-fold in db/db mice (p = 0.002. CONCLUSIONS/INTERPRETATION: BAS induced plasma glucose lowering in db/db mice by increasing metabolic clearance rate of glucose in peripheral tissues, which coincided with decreased skeletal muscle long-chain acylcarnitine content.

Curcumin restores mitochondrial functions and decreases lipid peroxidation in liver and kidneys of diabetic db/db mice

Directory of Open Access Journals (Sweden)

María G Soto-Urquieta

2014-01-01

Full Text Available BACKGROUND: Nitrosative and oxidative stress play a key role in obesity and diabetes-related mitochondrial dysfunction. The objective was to investigate the effect of curcumin treatment on state 3 and 4 oxygen consumption, nitric oxide (NO synthesis, ATPase activity and lipid oxidation in mitochondria isolated from liver and kidneys of diabetic db/db mice. RESULTS: Hyperglycaemia increased oxygen consumption and decreased NO synthesis in liver mitochondria isolated from diabetic mice relative to the control mice. In kidney mitochondria, hyperglycaemia increased state 3 oxygen consumption and thiobarbituric acid-reactive substances (TBARS levels in diabetic mice relative to control mice. Interestingly, treating db/db mice with curcumin improved or restored these parameters to normal levels; also curcumin increased liver mitochondrial ATPase activity in db/db mice relative to untreated db/db mice. CONCLUSIONS: These findings suggest that hyperglycaemia modifies oxygen consumption rate, NO synthesis and increases TBARS levels in mitochondria from the liver and kidneys of diabetic mice, whereas curcumin may have a protective role against these alterations.

INFLUENCIA DE LA BACTERIA Pseudomonas fluorescens EN LA LECHE, SOBRE LAS CARACTERÍSTICAS SENSORIALES DEL QUESO DOBLE CREMA

Directory of Open Access Journals (Sweden)

SJ González

2007-01-01

Full Text Available El objetivo de este trabajo fue observar el efecto de la presencia de microorganismos psicro-tróÀcos en la leche, sobre las características sensoriales del queso doble crema. Para esto, se inoculó la leche con un cultivo de Pseudomonas Áuorescens, a un nivel de 108 unidades formadoras de colonia por mililitro (ufc/ml. La leche se refrigeró a 4 ºC por seis días, se pasteurizó y posteriormente se preparó el queso. Se elaboraron lotes de queso cada 10 días, con el Àn de obtener siete tiempos experimentales. A cada uno se le determinó la vida útil sensorial. Los resultados de las pruebas sensoriales se analizaron con el programa S-PLUS de estadísti-ca de supervivencia aplicada a la vida útil sensorial de alimentos. Se determinó que el tiempo de vida útil sensorial del queso doble crema elaborado con leche en estas condiciones, y alma-cenado a 4 °C, está alrededor de 30 días, disminuyendo en un 50% con relación al patrón.

Accelerated storage testing of freeze-dried Pseudomonas ...

African Journals Online (AJOL)

Erika-Chris

Full Length Research Paper ... was possible to compare rate constants of survival for the freeze-dried P. fluorescens ... studying and predicting the survival loss rate of the ... Erlenmeyer flask containing 3000 ml King B medium. ... The strain was grown in 20 L bioreactor (Biolafite) containing 15 L .... fermented banana media.

Biological control of fusarium seedling blight disease of wheat and barley.

Science.gov (United States)

Khan, Mojibur R; Fischer, Sven; Egan, Damian; Doohan, Fiona M

2006-04-01

ABSTRACT Fusarium fungi, including F. culmorum, cause seedling blight, foot rot, and head blight diseases of cereals, resulting in yield loss. In a screen for potential disease control organisms and agents, Pseudomonas fluorescens strains MKB 100 and MKB 249, P. frederiksbergensis strain 202, Pseudomonas sp. strain MKB 158, and chitosan all significantly reduced the extent of both wheat coleoptile growth retardation and wheat and barley seedling blight caused by F. culmorum (by 53 to 91%). Trichodiene synthase is a Fusarium enzyme necessary for trichothecene mycotoxin biosynthesis; expression of the gene encoding this enzyme in wheat was 33% lower in stem base tissue coinoculated with Pseudomonas sp. strain MKB 158 and F. culmorum than in wheat treated with bacterial culture medium and F. culmorum. When wheat and barley were grown in soil amended with either chitosan, P. fluorescens strain MKB 249, Pseudomonas sp. strain MKB 158, or culture filtrates of these bacteria, the level of disease symptoms on F. culmorum-inoculated stem base tissue (at 12 days post- F. culmorum inoculation) was >/=31% less than the level on F. culmorum-inoculated plants grown in culture medium-amended soil. It seems likely that at least part of the biocontrol activity of these bacteria and chitosan may be due to the induction of systemic disease resistance in host plants. Also, in coinoculation studies, Pseudomonas sp. strain MKB 158 induced the expression of a wheat class III plant peroxidase gene (a pathogenesis-related gene).

Evaluation of potential bio-control agents on root-knot nematode ...

African Journals Online (AJOL)

Indigenous strains of Trichoderma viride (ITCC No. 6889), Pseudomonas fluorescens (ITCC No. B0034) and Purpureocillium lilacinum (ITCC No.6887) were isolated from undisturbed forest eco-system of Southern India. These three bio-mediators were evaluated for their antagonism towards root knot nematode, ...

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.

Regulatory mutations affecting the synthesis of cellulase in ...

African Journals Online (AJOL)

Pseudomonas fluorescens, was cultured in basal medium containing carboxymethyl-cellulose (CMC) as inducer and glucose or glycerol as carbon and energy sources. Ethylmethanesulphonate (EMS) was used to mutagenize the wild-type organism to produce mutants. The isolated mutants were screened for the isolation ...

An automated technique for most-probable-number (MPN) analysis of densities of phagotrophic protists with lux-AB labelled bacteria as growth medium

DEFF Research Database (Denmark)

Ekelund, Flemming; Christensen, Søren; Rønn, Regin

1999-01-01

An automated modification of the most-probable-number (MPN) technique has been developed for enumeration of phagotrophic protozoa. The method is based on detection of prey depletion in micro titre plates rather than on presence of protozoa. A transconjugant Pseudomonas fluorescens DR54 labelled w...

Evaluation of some bioagents and botanicals in in vitro control of ...

African Journals Online (AJOL)

Collectotrichum destructivum has not been effectively controlled. This led to trials on the use of bioagents and botanicals to control the pathogen. The bio-agents such as Pseudomonas fluorescens, Bacillus subtilis, Trichoderma harzianum and Trichoderma pseudokoningii were inoculated as dixenic culture with the ...

Rhizoxin analogs, orfamide A and chitinase production contribute to the toxicity of Pseudomonas protegens strain Pf-5 to Drosophila melanogaster

Science.gov (United States)

Pseudomonas protegens strain Pf-5 is a soil bacterium that was first described for its activity in biological control of plant diseases and has since been shown to be lethal to certain insects. Among these is the fruit fly Drosophila melanogaster, a well-established model organism for studies evalu...

Differential response of wheat cultivars to Pseudomonas brassicacearum and take-all decline soil.

Science.gov (United States)

Yang, Mingming; Mavrodi, Dmitri; Thomashow, Linda S; Weller, David M

2018-06-15

2,4-diacetylphloroglucinol (DAPG)-producing Pseudomonas spp. in the P. fluorescens complex are primarily responsible for a natural suppression of take-all of wheat known as take-all decline (TAD) in many fields in the USA. P. brassicacearum, the most common DAPG producer found in TAD soils in the Pacific Northwest (PNW) of the USA, has biocontrol, growth promoting and phytotoxic activities. In this study, we explored how the wheat cultivar affects the level of take-all suppression when grown in a TAD soil, and how cultivars respond to colonization by P. brassicacearum. Three cvs. Tara, Finley and Buchanan supported similar rhizosphere population sizes of P. brassicacearum when grown in a TAD soil, however they developed significantly different amounts of take-all. Cultivars Tara and Buchanan developed the least and most take-all, respectively, and Finley showed an intermediate amount of disease. However, when grown in TAD soil that was pasteurized to eliminate both DAPG producers and take-all suppression, all three cultivars were equally susceptible to take-all. The three cultivars also responded differently to the colonization and phytotoxicity of P. brassicacearum strains Q8r1-96 and L5.1-96, which are characteristic of DAPG producers in PNW TAD soils. As compared to cv. Tara, cv. Buchanan showed significantly reduced seedling emergence and root growth when colonized by P. brassicacearum, and the response of Finley was intermediate. However, all cultivars emerged equally when treated with a DAPG-deficient mutant of Q8r1-96. Our results indicate that wheat cultivars grown in a TAD soil modulate both the robustness of take-all suppression and the potential phytotoxicity of the antibiotic DAPG.

CouchDB the definitive guide

CERN Document Server

Anderson, J; Slater, Noah

2010-01-01

Three of CouchDB's creators show you how to use this document-oriented database as a standalone application framework or with high-volume, distributed applications. With its simple model for storing, processing, and accessing data, CouchDB is ideal for web applications that handle huge amounts of loosely structured data. That alone would stretch the limits of a relational database, yet CouchDB offers an open source solution that's reliable, scales easily, and responds quickly. CouchDB works with self-contained data that has loose or ad-hoc connections. It's a model that fits many real-world

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.

Telmisartan ameliorates insulin sensitivity by activating the AMPK/SIRT1 pathway in skeletal muscle of obese db/db mice

Directory of Open Access Journals (Sweden)

Shiota Asuka

2012-11-01

Full Text Available Abstract Background Telmisartan is a well-established angiotensin II type 1 receptor blocker that improves insulin sensitivity in animal models of obesity and insulin resistance, as well as in humans. Telmisartan has been reported to function as a partial agonist of the peroxisome proliferator-activated receptor (PPAR γ, which is also targeted by the nicotinamide adenine dinucleotide (NAD-dependent deacetylase (SIRT1. Here, we investigated the pathways through which telmisartan acts on skeletal muscle, in vitro as well as in vivo. Methods Nine-week-old male db/db mice were fed a 60% high-fat diet, with orally administrated either vehicle (carboxymethyl-cellulose, CMC, 5 mg/kg telmisartan, or 5 mg/kg telmisartan and 1 mg/kg GW9662, a selective irreversible antagonist of PPARγ, for 5 weeks. Effects of telmisartan on Sirt1 mRNA, AMPK phosphorylation, and NAD+/NADH ratio were determined in C2C12 cultured myocytes. Results and discussion Telmisartan treatment improved insulin sensitivity in obese db/db mice fed a high-fat diet and led to reduction in the size of hypertrophic pancreatic islets in these mice. Moreover, in vitro treatment with telmisartan led to increased expression of Sirt1 mRNA in C2C12 skeletal muscle cells; the increase in Sirt1 mRNA in telmisartan-treated C2C12 myoblasts occurred concomitantly with an increase in AMPK phosphorylation, an increase in NAD+/NADH ratio, and increases in the mRNA levels of PGC1α, FATP1, ACO, and GLUT4. Conclusions Our results indicate that telmisartan acts through a PPARγ-independent pathway, but at least partially exerts its effects by acting directly on skeletal muscle AMPK/SIRT1 pathways.

Anti-diabetic effect of amorphastilbol through PPARα/γ dual activation in db/db mice

Energy Technology Data Exchange (ETDEWEB)

Lee, Woojung; Ham, Jungyeob; Kwon, Hak Cheol [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of); Kim, Yong Kee, E-mail: yksnbk@sookmyung.ac.kr [College of Pharmacy, Sookmyung Women’s University, Seoul 140-742 (Korea, Republic of); Kim, Su-Nam, E-mail: snkim@kist.re.kr [Natural Medicine Center, KIST Gangneung Institute, Gangneung 210-340 (Korea, Republic of)

2013-03-01

Highlights: ► Amorphastilbol stimulates the transcriptional activities of both PPARα and PPARγ. ► Amorphastilbol improves glucose and lipid impairment in db/db mice. ► There are no side effects, such as hepatomegaly, in amorphastilbol-treated mice. ► Amorphastilbol can be used as a potential therapeutic agent against T2DM. - Abstract: Peroxisome proliferator-activated receptors (PPARs) have been considered as desirable targets for metabolic syndrome treatments, even though their specific agonists have several side effects, including body weight gain, edema, and tissue failure. The effects of amorphastilbol (APH) on glucose- and lipid metabolism were investigated with in vitro 3T3-L1 adipocyte systems and in vivo db/db mice model. APH selectively stimulates the transcriptional activities of both PPARα and PPARγ, which are able to enhance fatty acid oxidation and glucose utilization. Furthermore, APH improves glucose and lipid impairment in db/db mice. More importantly, there are no significant side effects, such as weight gain or hepatomegaly, in APH-treated animals, implying that APH do not adversely affect liver or lipid metabolism. All our data suggest that APH can be used as potential therapeutic agents against type 2 diabetes and related metabolic disorders, including obesity, by enhancing glucose and lipid metabolism.

Anti-diabetic effect of amorphastilbol through PPARα/γ dual activation in db/db mice

International Nuclear Information System (INIS)

Lee, Woojung; Ham, Jungyeob; Kwon, Hak Cheol; Kim, Yong Kee; Kim, Su-Nam

2013-01-01

Highlights: ► Amorphastilbol stimulates the transcriptional activities of both PPARα and PPARγ. ► Amorphastilbol improves glucose and lipid impairment in db/db mice. ► There are no side effects, such as hepatomegaly, in amorphastilbol-treated mice. ► Amorphastilbol can be used as a potential therapeutic agent against T2DM. - Abstract: Peroxisome proliferator-activated receptors (PPARs) have been considered as desirable targets for metabolic syndrome treatments, even though their specific agonists have several side effects, including body weight gain, edema, and tissue failure. The effects of amorphastilbol (APH) on glucose- and lipid metabolism were investigated with in vitro 3T3-L1 adipocyte systems and in vivo db/db mice model. APH selectively stimulates the transcriptional activities of both PPARα and PPARγ, which are able to enhance fatty acid oxidation and glucose utilization. Furthermore, APH improves glucose and lipid impairment in db/db mice. More importantly, there are no significant side effects, such as weight gain or hepatomegaly, in APH-treated animals, implying that APH do not adversely affect liver or lipid metabolism. All our data suggest that APH can be used as potential therapeutic agents against type 2 diabetes and related metabolic disorders, including obesity, by enhancing glucose and lipid metabolism

Utilization of biological control agents for the management of postharvest pathogens of tomato

International Nuclear Information System (INIS)

Zafar, M.U.; Ansari, S.U.

2016-01-01

Twenty five isolates of Trichoderma, Bacillus and Pseudomonas spp. were obtained from rhizosphere of tomato growing fields using soil dilution technique on potato dextrose agar (PDA) and nutrient agar (NA) medium. Screening of these isolates were done against Geotrichum candidum, Trichothecium roseum and Rhizopus oryzae, causal agents of sour rot, pink mold rot and Rhizopus soft rot of tomato under the laboratory conditions. One promising isolate of each Trichoderma harzianum, Bacillus spp. and Pseudomonas fluorescens from the twenty five isolates were chosen and further evaluated as potential biological control agents (BCAs) against three important postharvest pathogens of tomato. Dual culture and spore concentration assay revealed that all three isolates inhibited radial growth of G. candidum, T. roseum and R. oryzae. Tomato fruits were inoculated with 25 micro L suspension of 10/sup 8/ cfu mL-1 for T. harzianum and 10/sup 8/cfu mL-1for each Bacillus sp. and P. fluorescens. Twenty four hours later the treated fruits were inoculated with 25 micro L of 105 conidia/mL of each of three postharvest pathogens. The results showed that P. fluorescens provided good control (78.1%) of G. candidum and (82.2%) R. oryzae, while, T. harzianum proved less effective to control all three pathogens. Bacillus spp. was only effective (88.4%) against T. roseum. Hence, our results depicted that Bacillus spp. and P. fluorescens proved to be a potential antagonist of T. roseum and R. oryzae however, all the tested BCAs were not consistent in their action against three postharvest pathogens of tomato. (author)

Getting Started with CouchDB

CERN Document Server

Brown, MC

2012-01-01

CouchDB is a new breed of database for the Internet, geared to meet the needs of today's dynamic web applications. With this concise introduction, you'll learn how CouchDB's simple model for storing, processing, and accessing data makes it ideal for the type of data and rapid response users now demand from your applications-and how easy CouchDB is to set up, deploy, maintain, and scale. The code-packed examples in this book will help you learn how to work with documents, populate a simple database, replicate data from one database to another, and a host of other tasks. Install CouchDB on Lin

Getting started with MariaDB

CERN Document Server

Bartholomew, Daniel

2013-01-01

A practical, hands-on, beginner-friendly guide to installing and using MariaDB.Getting Started with MariaDB is for anyone who wants to learn more about databases in general or MariaDB in particular. No prior database experience is required. It is assumed that you have basic knowledge of software installation, editing files with a text editor, and using the command line and terminal.

Peripherally administered baclofen reduced food intake and body weight in db/db as well as diet-induced obese mice.

Science.gov (United States)

Sato, Ikuko; Arima, Hiroshi; Ozaki, Noriyuki; Ozaki, Nobuaki; Watanabe, Minemori; Goto, Motomitsu; Shimizu, Hiroshi; Hayashi, Masayuki; Banno, Ryouichi; Nagasaki, Hiroshi; Oiso, Yutaka

2007-10-16

Peripheral administration of baclofen significantly reduced food intake and body weight increase in both diabetic (db/db) and diet-induced obese mice for 5 weeks, whereas it had no significant effects on energy balance in their lean control mice. Despite the decreased body weight, neuropeptide Y expression in the arcuate nucleus was significantly decreased, whereas pro-opiomelanocortin expression was significantly increased by baclofen treatment. These data demonstrate that the inhibitory effects of baclofen on body weight in the obese mice were mediated via the arcuate nucleus at least partially, and suggest that GABA(B) agonists could be a new therapeutic reagent for obesity.

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...

Author Details

African Journals Online (AJOL)

Effects of Different Carbon Sources on Biosurfactant Production by a Pseudomonas fluorescens Isolate Abstract · Vol 16 (2013) - Articles Production and properties of fungal cellulase from native isolates using orange bagasse as carbon source. Abstract · Vol 16 (2013) - Articles Production and characterization of pectinases ...

Evolution of REP diversity: a comparative study

Czech Academy of Sciences Publication Activity Database

Nunvář, Jaroslav; Lichá, I.; Schneider, Bohdan

2013-01-01

Roč. 14, č. 385 (2013) ISSN 1471-2164 R&D Projects: GA ČR GAP305/12/1801 Institutional research plan: CEZ:AV0Z50520701 Keywords : REP elements * Stenotrophomonas maltophilia * Pseudomonas fluorescens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.041, year: 2013

Utilization of Indigenous Microbial Isolates and their Mutants in the ...

African Journals Online (AJOL)

This study was designed to evaluate the ability of Pseudomonas fluorescens, Aspergillus fumigatus and Aspergillus niger to degrade cellulosic medical waste. Biodegradation was carried out in bioreactors and the ability to degrade or utilize cellulose was established on the basis of bacterial growth on cellulose medium ...

Degradation of 2,4-DB in Argentinean agricultural soils with high humic matter content.

Science.gov (United States)

Cuadrado, Virginia; Merini, Luciano J; Flocco, Cecilia G; Giulietti, Ana M

2008-01-01

The dissipation of 4-(2,4-dichlorophenoxy) butyric acid (2,4-DB) in high-humic-matter-containing soils from agricultural fields of the Argentinean Humid Pampa region was studied, employing soil microcosms under different experimental conditions. The added herbicide was dissipated almost completely by soils with and without history of herbicide use by day 28. At 500 ppm, both soils showed the same degradation rates; but at 5-ppm concentration, the chronically exposed soil demonstrated a faster degradation of the herbicide. 2,4-DB addition produced increases in herbicide-degrading bacteria of three and 1.5 orders of magnitude in soils with and without history of herbicide use, respectively, in microcosms with 5 ppm. At 500-ppm concentration, the increase in 2,4-DB degraders was five orders of magnitude after 14 days, independent of the history of herbicide use. No differences were observed in either 2,4-DB degradation rates or in degrader bacteria numbers in the presence and absence of alfalfa plants, in spite of some differential characteristics in patterns of 2,4-DB metabolite accumulation. The main factor affecting 2,4-DB degradation rate would be the history of herbicide use, as a consequence of the adaptation of the indigenous microflora to the presence of herbicides in the field.

MongoDB and PHP

CERN Document Server

Francia, Steve

2012-01-01

What would happen if you optimized a data store for the operations application developers actually use? You'd arrive at MongoDB, the reliable document-oriented database. With this concise guide, you'll learn how to build elegant database applications with MongoDB and PHP. Written by the Chief Solutions Architect at 10gen-the company that develops and supports this open source database-this book takes you through MongoDB basics such as queries, read-write operations, and administration, and then dives into MapReduce, sharding, and other advanced topics. Get out of the relational database rut,

Effect of zinc nutriture on tissue zinc (Zn) in the diabetic C57BL/KsJ db/db mouse

International Nuclear Information System (INIS)

Donaldson, D.L.; Smith, C.C.; Walker, M.S.; Yunice, A.A.; Rennert, O.M.

1986-01-01

The genetically obese diabetic db/db mouse has been reported to have low serum (S) and femur (F) Zn concentrations. In order to examine whether this animal model is predisposed to dietary Zn deficiency, they measured tissue Zn concentrations (conc.) in db/db, heterozygous db/m, and homozygous m/m control mice fed either a zinc deficient diet (2 ppm Zn) ad libitum or a zinc adequate diet (20 ppm Zn) either ad libitum or in restricted amounts (equal to that consumed by mice on the 2 ppm Zn diet) for 12 wks. The results were analyzed by analysis of variance for a completely randomized 3X3 design. Similar clinical manifestations of Zn deficiency were seen in mice of all 3 genotypes after 8-10 weeks on 2 ppm Zn. S Zn(p=0.0001) and F Zn conc.(p=0.0001) and content(p=0.0001) of those 3 groups showed similar marked reductions. S Zn was not reduced in db/db mice fed 20 ppm Zn. F Zn conc. was mildly reduced in these mice but not to the extent observed in mice fed 2 ppm Zn. Liver (L) Zn conc. was not affected by either genotype or diet, but total L Zn(p=0.0001) was greater in db/db mice due to their larger L weight. Kidney (K) Zn conc.(p=0.0001) of db/db mice was slightly but significantly decreased, but their total K Zn content(p=0.0001) was increased due to their greater K weights. They conclude that, in spite of its having a decreased F Zn conc. and content, the db/db mouse does not appear to be particularly susceptible to dietary Zn deficiency

Anti-Pseudomonas aeruginosa compound, 1,2,3,4-tetrahydro-1,3,5-triazine derivative, exerts its action by primarily targeting MreB.

Science.gov (United States)

Yamachika, Shinichiro; Sugihara, Chika; Tsuji, Hayato; Muramatsu, Yasunori; Kamai, Yasuki; Yamashita, Makoto

2012-01-01

In order to find new anti-Pseudomonas agents, we carried out whole-cell based P. aeruginosa growth assay, and identified 1,2,3,4-tetrahydro-1,3,5-triazine (Compound A). This compound showed anti-Pseudomonas activity against wild as well as pumpless strain equally at a same concentration. Also, this compound was structurally very similar to A22, which is known to inhibit the bacterial actin-like protein MreB. By the analysis of resistant strains, the primary target of this compound in P. aeruginosa was definitely confirmed to be MreB. In addition, these compounds showed a bacteriostatic effect, and induced the morphology changes in P. aeruginosa from rod shape to sphere shape, which leads to be clinically favorable in terms of susceptibility to phagocytosis and release of endotoxin. These results display that Compound A is a very attractive compound which shows anti-P. aeruginosa activity based on inhibition of MreB without being affected by efflux pumps, and could provide a new step toward development of new promising anti-Pseudomonas agents, MreB inhibitors.

Impact of lead tolerant plant growth promoting rhizobacteria on growth, physiology, antioxidant activities, yield and lead content in sunflower in lead contaminated soil.

Science.gov (United States)

Saleem, Muhammad; Asghar, Hafiz Naeem; Zahir, Zahir Ahmad; Shahid, Muhammad

2018-03-01

Present study was conducted to evaluate the effect of lead tolerant plant growth promoting rhizobacteria (LTPGPR) on growth, physiology, yield, antioxidant activities and lead uptake in sunflower in soil contaminated with lead under pot conditions. Three pre-characterized LTPGP strains (S2 (Pseudomonas gessardii strain BLP141), S5 (Pseudomonas fluorescens A506) and S10 (Pseudomonas fluorescens strain LMG 2189)) were used to inoculate sunflower growing in soil contaminated with different levels (300, 600 and 900 mg kg -1 ) of lead by using lead nitrate salt as source of lead. Treatments were arranged according to completely randomized design with factorial arrangements. At harvesting, data regarding growth attributes (root shoot length, root shoot fresh and dry weights), yield per plant, physiological attributes (Chlorophyll 'a', 'b' and carotenoids content), antioxidant activities (Ascorbate peroxidase, catalase, superoxide dismutase and glutathione reductase), proline and malanodialdehyde content, and lead content in root, shoot and achenes of sunflower were recorded. Data were analysed by standard statistical procedures. Results showed that lead contamination reduced the plants growth, physiology and yield at all levels of lead stress. But application of LTPGPR in soil contaminated with lead improved plant growth, physiology, yield, and antioxidant activities, proline, and reduced the malanodialdehyde content (that is reduced by the application of different strains in lead contamination) of sunflower as compared to plants grown in soil without inoculation. Inoculation also promoted the uptake of lead in root, shoots and reduced the uptake of lead in achenes of plants as compared to plants in lead contamination without inoculation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Low-Power Single-Bit Continuous-Time ΔΣ Converter with 92.5 dB Dynamic Range for Biomedical Applications

Directory of Open Access Journals (Sweden)

Vishal Saxena

2012-07-01

Full Text Available A third-order single-bit CT-ΔΣ modulator for generic biomedical applications is implemented in a 0.15 µm FDSOI CMOS process. The overall power efficiency is attained by employing a single-bit ΔΣ and a subthreshold FDSOI process. The loop-filter coefficients are determined using a systematic design centering approach by accounting for the integrator non-idealities. The single-bit CT-ΔΣ modulator consumes 110 µW power from a 1.5 V power supply when clocked at 6.144 MHz. The simulation results for the modulator exhibit a dynamic range of 94.4 dB and peak SNDR of 92.4 dB for 6 kHz signal bandwidth. The figure of merit (FoM for the third-order, single-bit CT-ΔΣ modulator is 0.271 pJ/level.

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....

Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor

Energy Technology Data Exchange (ETDEWEB)

Yadav, Rana Pratap, E-mail: ranayadav97@gmail.com; Kumar, Sunil; Kulkarni, S. V. [Thapar University, Patiala, Punjab 147004, India and Institute for Plasma Research, Gandhinagar 382428 (India)

2016-01-15

Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.

MRC5 and QU-DB bystander cells can produce bystander factors and induce radiation bystander effect

Directory of Open Access Journals (Sweden)

Mohammad Taghi Bahreyni Toossi

2014-01-01

Full Text Available Radiation damages initiated by radiation-induced bystander effect (RIBE are not limited to the first or immediate neighbors of the irradiated cells, but the effects have been observed in the cells far from the irradiation site. It has been postulated that bystander cells, by producing bystander factors, are actively involved in the propagation of bystander effect in the regions beyond the initial irradiated site. Current study was planned to test the hypothesis. MRC5 and QU-DB cell lines were irradiated, and successive medium transfer technique was performed to induce bystander effects in two bystander cell groups. Conditioned medium extracted from the target cells was transferred to the bystander cells (first bystander cells. After one hour, conditioned medium was substituted by fresh medium. Two hours later, the fresh medium was transferred to a second group of non-irradiated cells (second bystander cells. Micronucleated cells (MC were counted to quantify damages induced in the first and second bystander cell groups. Radiation effect was observed in the second bystander cells as well as in the first ones. Statistical analyses revealed that the number of MC in second bystander subgroups was significantly more than the corresponding value observed in control groups, but in most cases it was equal to the number of MC observed in the first bystander cells. MRC5 and QU-DB bystander cells can produce and release bystander signals in the culture medium and affect non-irradiated cells. Therefore, they may contribute to the RIBE propagation.

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).

Volatile-mediated interactions between phylogenetically different soil bacteria

Directory of Open Access Journals (Sweden)

Paolina eGarbeva

2014-06-01

Full Text Available There is increasing evidence that organic volatiles play an important role in interactions between micro-organisms in the porous soil matrix. Here we report that volatile compounds emitted by different soil bacteria can affect the growth, antibiotic production and gene expression of the soil bacterium Pseudomonas fluorescens Pf0-1. We applied a novel cultivation approach that mimics the natural nutritional heterogeneity in soil in which P. fluorescens grown on nutrient-limited agar was exposed to volatiles produced by 4 phylogenetically different bacterial isolates (Collimonas pratensis, Serratia plymuthica, Paenibacillus sp. and Pedobacter sp. growing in sand containing artificial root exudates. Contrary to our expectation, the produced volatiles stimulated rather than inhibited the growth of P. fluorescens. A genome-wide, microarray-based analysis revealed that volatiles of all 4 bacterial strains affected gene expression of P. fluorescens, but with a different pattern of gene expression for each strain. Based on the annotation of the differently expressed genes, bacterial volatiles appear to induce a chemotactic motility response in P. fluorescens, but also an oxidative stress response. A more detailed study revealed that volatiles produced by C. pratensis triggered, antimicrobial secondary metabolite production in P. fluorescens. Our results indicate that bacterial volatiles can have an important role in communication, trophic - and antagonistic interactions within the soil bacterial community.

Influence of multiple bioprocess parameters on production of lipase from Pseudomonas sp. BWS-5

Directory of Open Access Journals (Sweden)

Balwinder Singh Sooch

2013-10-01

Full Text Available The aim of the present work was to study the influence of multiple bioprocess parameters for the maximum production of lipase from Pseudomonas sp. BWS-5. The culture reached the stationary phase of growth after 36h of incubation when the maximum lipase production was obtained at flask level. The different media components such as carbon sources, nitrogen sources, trace elements and process parameters such as the pH of the medium, temperature and time of incubation, agitation/stationary conditions, etc. were optimized at flask level and at bioreactor level. The maximum enzyme production of 298 IU/mL was obtained with the use of simple medium with pH 6.5 containing glucose (1 %, w/v, peptone (3 %, w/v and KCl (0.05 %, w/v after 30h of incubation at 37°C under agitation (200 rpm conditions with 0.75 vvm of air supply.

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].

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.

Molecular basis and regulation of insect pathogenicity in plant-beneficial pseudomonads

OpenAIRE

Kupferschmied, P.

2015-01-01

Les bactéries du genre Pseudomonas ont la capacité étonnante de s'adapter à différents habitats et d'y survivre, ce qui leur a permis de conquérir un large éventail de niches écologiques et d'interagir avec différents organismes hôte. Les espèces du groupe Pseudomonas fluorescens peuvent être facilement isolées de la rhizosphère et sont communément connues comme des Pseudomonas bénéfiques pour les plantes. Elles sont capables d'induire la résistance systémique des plantes, d'induire leur croi...

Reduced sulfation of chondroitin sulfate but not heparan sulfate in kidneys of diabetic db/db mice.

Science.gov (United States)

Reine, Trine M; Grøndahl, Frøy; Jenssen, Trond G; Hadler-Olsen, Elin; Prydz, Kristian; Kolset, Svein O

2013-08-01

Heparan sulfate proteoglycans are hypothesized to contribute to the filtration barrier in kidney glomeruli and the glycocalyx of endothelial cells. To investigate potential changes in proteoglycans in diabetic kidney, we isolated glycosaminoglycans from kidney cortex from healthy db/+ and diabetic db/db mice. Disaccharide analysis of chondroitin sulfate revealed a significant decrease in the 4-O-sulfated disaccharides (D0a4) from 65% to 40%, whereas 6-O-sulfated disaccharides (D0a6) were reduced from 11% to 6%, with a corresponding increase in unsulfated disaccharides. In contrast, no structural differences were observed in heparan sulfate. Furthermore, no difference was found in the molar amount of glycosaminoglycans, or in the ratio of hyaluronan/heparan sulfate/chondroitin sulfate. Immunohistochemical staining for the heparan sulfate proteoglycan perlecan was similar in both types of material but reduced staining of 4-O-sulfated chondroitin and dermatan was observed in kidney sections from diabetic mice. In support of this, using qRT-PCR, a 53.5% decrease in the expression level of Chst-11 (chondroitin 4-O sulfotransferase) was demonstrated in diabetic kidney. These results suggest that changes in the sulfation of chondroitin need to be addressed in future studies on proteoglycans and kidney function in diabetes.

AFM-based detection of glycocalyx degradation and endothelial stiffening in the db/db mouse model of diabetes.

Science.gov (United States)

Targosz-Korecka, Marta; Jaglarz, Magdalena; Malek-Zietek, Katarzyna E; Gregorius, Aleksandra; Zakrzewska, Agnieszka; Sitek, Barbara; Rajfur, Zenon; Chlopicki, Stefan; Szymonski, Marek

2017-11-21

Degradation of the glycocalyx and stiffening of endothelium are important pathophysiological components of endothelial dysfunction. However, to our knowledge, these events have not been investigated in tandem in experimental diabetes. Here, the mechanical properties of the glycocalyx and endothelium in ex vivo mouse aorta were determined simultaneously in indentation experiments with an atomic force microscope (AFM) for diabetic db/db and control db/+ mice at ages of 11-19 weeks. To analyze highly heterogeneous aorta samples, we developed a tailored classification procedure of indentation data based on a bi-layer brush model supplemented with Hertz model for quantification of nanomechanics of endothelial regions with and without the glycocalyx surface. In db/db mice, marked endothelial stiffening and reduced glycocalyx coverage were present already in 11-week-old mice and persisted in older animals. In contrast, reduction of the effective glycocalyx length was progressive and was most pronounced in 19-week-old db/db mice. The reduction of the glycocalyx length correlated with an increasing level of glycated haemoglobin and decreased endothelial NO production. In conclusion, AFM nanoindentation analysis revealed that stiffening of endothelial cells and diminished glycocalyx coverage occurred in early diabetes and were followed by the reduction of the glycocalyx length that correlated with diabetes progression.

Magnolia officinalis Extract Contains Potent Inhibitors against PTP1B and Attenuates Hyperglycemia in db/db Mice

Directory of Open Access Journals (Sweden)

Jing Sun

2015-01-01

Full Text Available Protein tyrosine phosphatase 1B (PTP1B is an established therapeutic target for type 2 diabetes mellitus (T2DM and obesity. The aim of this study was to investigate the inhibitory activity of Magnolia officinalis extract (ME on PTP1B and its anti-T2DM effects. Inhibition assays and inhibition kinetics of ME were performed in vitro. 3T3-L1 adipocytes and C2C12 myotubes were stimulated with ME to explore its bioavailability in cell level. The in vivo studies were performed on db/db mice to probe its anti-T2DM effects. In the present study, ME inhibited PTP1B in a reversible competitive manner and displayed good selectivity against PTPs in vitro. Furthermore, ME enhanced tyrosine phosphorylation levels of cellular proteins, especially the insulin-induced tyrosine phosphorylations of insulin receptor β-subunit (IRβ and ERK1/2 in a dose-dependent manner in stimulated 3T3-L1 adipocytes and C2C12 myotubes. Meanwhile, ME enhanced insulin-stimulated GLUT4 translocation. More importantly, there was a significant decrease in fasting plasma glucose level of db/db diabetic mice treated orally with 0.5 g/kg ME for 4 weeks. These findings indicated that improvement of insulin sensitivity and hypoglycemic effects of ME may be attributed to the inhibition of PTP1B. Thereby, we pioneered the inhibitory potential of ME targeted on PTP1B as anti-T2DM drug discovery.

Priming of plant innate immunity by rhizobacteria and β-aminobutyric acid: differences and similarities in regulation

NARCIS (Netherlands)

Ent, S. van der; Hulten, M.H.A. van; Pozo, Maria J.; Czechowski, Tomasz; Udvardi, Michael K.; Pieterse, C.M.J.; Ton, J.

Pseudomonas fluorescens WCS417r bacteria and β-aminobutyric acid can induce disease resistance in Arabidopsis, which is based on priming of defence. In this study, we examined the differences and similarities of WCS417r- and β-aminobutyric acid-induced priming. Both WCS417r and β-aminobutyric acid

Sharing mutants and experimental information prepublication using FgMutantDb (https://scabusa.org/FgMutantDb).

Science.gov (United States)

Baldwin, Thomas T; Basenko, Evelina; Harb, Omar; Brown, Neil A; Urban, Martin; Hammond-Kosack, Kim E; Bregitzer, Phil P

2018-06-01

There is no comprehensive storage for generated mutants of Fusarium graminearum or data associated with these mutants. Instead, researchers relied on several independent and non-integrated databases. FgMutantDb was designed as a simple spreadsheet that is accessible globally on the web that will function as a centralized source of information on F. graminearum mutants. FgMutantDb aids in the maintenance and sharing of mutants within a research community. It will serve also as a platform for disseminating prepublication results as well as negative results that often go unreported. Additionally, the highly curated information on mutants in FgMutantDb will be shared with other databases (FungiDB, Ensembl, PhytoPath, and PHI-base) through updating reports. Here we describe the creation and potential usefulness of FgMutantDb to the F. graminearum research community, and provide a tutorial on its use. This type of database could be easily emulated for other fungal species. Published by Elsevier Inc.

Tangshen formula attenuates hepatic steatosis by inhibiting hepatic lipogenesis and augmenting fatty acid oxidation in db/db mice.

Science.gov (United States)

Kong, Qin; Zhang, Haojun; Zhao, Tingting; Zhang, Weiku; Yan, Meihua; Dong, Xi; Li, Ping

2016-12-01

Tangshen formula (TSF), a well-prescribed traditional Chinese formula, has been used in the treatment of diabetic nephropathy. However, whether TSF ameliorates dyslipidemia and liver injury associated with diabetes remains unclear. In this study, we examined the effects of TSF on lipid profiles and hepatic steatosis in db/db mice. For this purpose, 8‑week-old db/db mice were treated with TSF or saline for 12 weeks via gavage and db/m mice were used as controls. Body weight and blood glucose levels were monitored weekly and bi-weekly, respectively. Blood samples were obtained for the analysis of lipids and enzymes related to hepatic function, and liver tissues were analyzed by histology, immunohistochemistry and molecular examination. The results revealed that TSF markedly reduced body weight, liver index [liver/body weight (LW/BW)] and improved lipid profiles, hepatic function and steatosis in db/db mice. TSF induced the phosphoralation of AMP-activated protein kinase and inhibited the activity of sterol regulatory element-binding protein 1 together with the inhibition of the expression of genes involved in de novo lipogenesis (DNL) and gluconeogenesis, such as fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), stearoyl CoA desaturase 1 (SCD1), glucose-6-phosphatase (G6pc) and phosphoenolpyruvate carboxykinase 1 (Pck1). Additionally, the silent mating type information regulation 2 homolog 1 (Sirt1)/peroxisome proliferator-activated receptor α (PPARα)/malonyl-CoA decarboxylase (MLYCD) cascade was potently activated by TSF in the liver and skeletal muscle of db/db mice, which led to enhanced fatty acid oxidation. These findings demonstrated that TSF attenuated hepatic fat accumulation and steatosis in db/db mice by inhibiting lipogenesis and augmenting fatty acid oxidation.

Improved cerebral energetics and ketone body metabolism in db/db mice

DEFF Research Database (Denmark)

Andersen, Jens V; Christensen, Sofie K; Nissen, Jakob D

2017-01-01

It is becoming evident that type 2 diabetes mellitus is affecting brain energy metabolism. The importance of alternative substrates for the brain in type 2 diabetes mellitus is poorly understood. The aim of this study was to investigate whether ketone bodies are relevant candidates to compensate...... metabolism in type 2 diabetes mellitus. The increased hippocampal ketone body utilization and improved mitochondrial function in db/db mice, may act as adaptive mechanisms in order to maintain cerebral energetics during hampered glucose metabolism....

A 60-dB linear VGA with novel exponential gain approximation

International Nuclear Information System (INIS)

Zhou Jiaye; Tan Xi; Wang Junyu; Tang Zhangwen; Min Hao

2009-01-01

A CMOS variable gain amplifier (VGA) that adopts a novel exponential gain approximation is presented. No additional exponential gain control circuit is required in the proposed VGA used in a direct conversion receiver. A wide gain control voltage from 0.4 to 1.8 V and a high linearity performance are achieved. The three-stage VGA with automatic gain control (AGC) and DC offset cancellation (DCOC) is fabricated in a 0.18-μm CMOS technology and shows a linear gain range of more than 58-dB with a linearity error less than ±1 dB. The 3-dB bandwidth is over 8 MHz at all gain settings. The measured input-referred third intercept point (IIP3) of the proposed VGA varies from -18.1 to 13.5 dBm, and the measured noise figure varies from 27 to 65 dB at a frequency of 1 MHz. The dynamic range of the closed-loop AGC exceeds 56 dB, where the output signal-to-noise-and-distortion ratio (SNDR) reaches 20 dB. The whole circuit, occupying 0.3 mm 2 of chip area, dissipates less than 3.7 mA from a 1.8-V supply.

MongoDB the definitive guide

CERN Document Server

Chodorow, Kristina

2010-01-01

How does MongoDB help you manage a huMONGOus amount of data collected through your web application? With this authoritative introduction, you'll learn the many advantages of using document-oriented databases, and discover why MongoDB is a reliable, high-performance system that allows for almost infinite horizontal scalability. Written by engineers from 10gen, the company that develops and supports this open source database, MongoDB: The Definitive Guide provides guidance for database developers, advanced configuration for system administrators, and an overview of the concepts and use cases f

Le Pseudomonas: Experience du Centre des Brules D’Annaba et Revue de la Litterature

Science.gov (United States)

Chaibdraa, A.; Medjellekh, M.S.; Saouli, A.; Bentakouk, M.C.

2008-01-01

Summary Le Pseudomonasest un agent pathogène à l'origine d'infections nosocomiales graves dans les centres des brûlés. Son opportunisme et sa virulence en font une préoccupation majeure. Ce travail se propose d'évaluer la place de cette bactérie dans l'écologie bactérienne locale et d'en apprécier la sensibilité aux antibiotiques. Cette étude rétrospective préliminaire porte sur la période de juin 2003 à décembre 2005. Elle intéresse l'ensemble des prélèvements bactériologiques ayant pu être réalisés au centre des brûlés d'Annaba. L'effectif est de 633 micro-organismes isolés dont 128 Pseudomonas (20,2%): 127 aeruginosa (99,2%), 1 fluorescens (0,8%); distribution selon le site de prélèvement: écouvillon (87,5%), prélèvement trachéobronchique (4,6%), hémoculture (3,1%), cathéters (1,6%), urine (1,6%) et sonde urinaire (1,6%). Le pyocyanique se situe après le staphylocoque pour les prélèvements précoces et repasse en tête après un séjour supérieur à une semaine, où 89% des pyocyaniques sont identifiés. Il est en première position dans les pneumopathies sous ventilation assistée invasive. Il se classe troisième dans les hémocultures et les cultures de cathéters. Dans les infections urinaires il est devancé par Candida et la flore périnéale. Les 128 antibiogrammes regroupent 314 réponses sensibles. La sensibilité à plus de deux antibiotiques est de 68%, à deux antibiotiques 24% et à un antibiotique 8%. Seules quatre molécules restent actives: ciprofloxacine > péfloxacine > pipéracilline > ceftazidime. Une résistance absolue est retrouvée pour trois Pseudomonas (2,4%). Le pronostic sévère des infections nosocomiales à pyocyanique et les risques d'options thérapeutiques très limitées font toute leur gravité, d'où l'intérêt de respecter des règles strictes de prescription des antibiotiques et des mesures de prévention. PMID:21991140

The db/db mouse: a useful model for the study of diabetic retinal neurodegeneration.

Directory of Open Access Journals (Sweden)

Patricia Bogdanov

Full Text Available BACKGROUND: To characterize the sequential events that are taking place in retinal neurodegeneration in a murine model of spontaneous type 2 diabetes (db/db mouse. METHODS: C57BLKsJ-db/db mice were used as spontaneous type 2 diabetic animal model, and C57BLKsJ-db/+ mice served as the control group. To assess the chronological sequence of the abnormalities the analysis was performed at different ages (8, 16 and 24 weeks. The retinas were evaluated in terms of morphological and functional abnormalities [electroretinography (ERG]. Histological markers of neurodegeneration (glial activation and apoptosis were evaluated by immunohistochemistry. In addition glutamate levels and glutamate/aspartate transporter (GLAST expression were assessed. Furthermore, to define gene expression changes associated with early diabetic retinopathy a transcriptome analyses was performed at 8 week. Furthermore, an additional interventional study to lower blood glucose levels was performed. RESULTS: Glial activation was higher in diabetic than in non diabetic mice in all the stages (p<0.01. In addition, a progressive loss of ganglion cells and a significant reduction of neuroretinal thickness were also observed in diabetic mice. All these histological hallmarks of neurodegeneration were less pronounced at week 8 than at week 16 and 24. Significant ERG abnormalities were present in diabetic mice at weeks 16 and 24 but not at week 8. Moreover, we observed a progressive accumulation of glutamate in diabetic mice associated with an early downregulation of GLAST. Morphological and ERG abnormalities were abrogated by lowering blood glucose levels. Finally, a dysregulation of several genes related to neurotransmission and oxidative stress such as UCP2 were found at week 8. CONCLUSIONS: Our results suggest that db/db mouse reproduce the features of the neurodegenerative process that occurs in the human diabetic eye. Therefore, it seems an appropriate model for investigating the

An aqueous extract of Portulaca oleracea ameliorates diabetic nephropathy through suppression of renal fibrosis and inflammation in diabetic db/db mice.

Science.gov (United States)

Lee, An Sook; Lee, Yun Jung; Lee, So Min; Yoon, Jung Joo; Kim, Jin Sook; Kang, Dae Gill; Lee, Ho Sub

2012-01-01

Diabetic nephropathy is one of the most common microvascular complications of diabetes and the leading cause of end-stage renal disease. In the present study, we investigated the renoprotective effect of the aqueous extract of Portulaca oleracea (AP) on diabetic nephropathy accelerated by renal fibrosis and inflammation in type 2 diabetic db/db mice. The mice were treated with AP (300 mg/kg/day, p.o.) for ten weeks to examine the long-term effects on diabetic nephropathy and renal dysfunction. We found that AP treatment markedly lowered blood glucose to 412 ± 11.4 mg/dl and plasma creatinine level to 2.3 ± 0.8 mg/dl compared to db/db mice (p < 0.05, p < 0.01, respectively). This study also showed that treatment with AP significantly decreased water intake and urine volume in diabetic db/db mice (p < 0.05). In immunohistological study, the renal expression of transforming growth factor-β1 (TGF-β1), advanced glycation end products (AGE), and intercellular adhesion molecule (ICAM)-1 markedly increased in the renal cortex of untreated db/db mice (p < 0.01). In contrast, AP treatment significantly reduced these expressions to 50 ± 2.1%, 48 ± 2.8%, 61 ± 1.1%, respectively (p < 0.01). Furthermore, NF-κB p65 activation in renal tissues markedly increased in untreated db/db mice, which was significantly suppressed by AP treatment. Taken together, these findings suggest that AP attenuates diabetic nephropathy through inhibition of renal fibrosis and inflammation in db/db mice.

Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

Energy Technology Data Exchange (ETDEWEB)

Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya, E-mail: jyli@mail.shcnc.ac.cn; Nan, Fa-Jun, E-mail: fjnan@mail.shcnc.ac.cn; Li, Jia, E-mail: jli@mail.shcnc.ac.cn

2013-12-01

AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome.

Novel small-molecule AMPK activator orally exerts beneficial effects on diabetic db/db mice

International Nuclear Information System (INIS)

Li, Yuan-Yuan; Yu, Li-Fang; Zhang, Li-Na; Qiu, Bei-Ying; Su, Ming-Bo; Wu, Fang; Chen, Da-Kai; Pang, Tao; Gu, Min; Zhang, Wei; Ma, Wei-Ping; Jiang, Hao-Wen; Li, Jing-Ya; Nan, Fa-Jun; Li, Jia

2013-01-01

AMP-activated protein kinase (AMPK), which is a pivotal guardian of whole-body energy metabolism, has become an attractive therapeutic target for metabolic syndrome. Previously, using a homogeneous scintillation proximity assay, we identified the small-molecule AMPK activator C24 from an optimization based on the original allosteric activator PT1. In this paper, the AMPK activation mechanism of C24 and its potential beneficial effects on glucose and lipid metabolism on db/db mice were investigated. C24 allosterically stimulated inactive AMPK α subunit truncations and activated AMPK heterotrimers by antagonizing autoinhibition. In primary hepatocytes, C24 increased the phosphorylation of AMPK downstream target acetyl-CoA carboxylase dose-dependently without changing intracellular AMP/ATP ratio, indicating its allosteric activation in cells. Through activating AMPK, C24 decreased glucose output by down-regulating mRNA levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) in primary hepatocytes. C24 also decreased the triglyceride and cholesterol contents in HepG2 cells. Due to its improved bioavailability, chronic oral treatment with multiple doses of C24 significantly reduced blood glucose and lipid levels in plasma, and improved the glucose tolerance of diabetic db/db mice. The hepatic transcriptional levels of PEPCK and G6Pase were reduced. These results demonstrate that this orally effective activator of AMPK represents a novel approach to the treatment of metabolic syndrome. - Highlights: • C24 activates AMPK through antagonizing autoinhibition within α subunit. • C24 activates AMPK in hepatocytes and decreases glucose output via AMPK. • C24 exerts beneficial effects on diabetic db/db mice. • C24 represents a novel therapeutic for treatment of metabolic syndrome

dbSNP

Data.gov (United States)

U.S. Department of Health & Human Services — dbSNP is a database of single nucleotide polymorphisms (SNPs) and multiple small-scale variations that include insertions/deletions, microsatellites, and...

Quantification of biofilm structures by the novel computer program COMSTAT.

Science.gov (United States)

Heydorn, A; Nielsen, A T; Hentzer, M; Sternberg, C; Givskov, M; Ersbøll, B K; Molin, S

2000-10-01

The structural organization of four microbial communities was analysed by a novel computer program, COMSTAT, which comprises ten features for quantifying three-dimensional biofilm image stacks. Monospecies biofilms of each of the four bacteria, Pseudomonas: putida, P. aureofaciens, P. fluorescens and P. aeruginosa, tagged with the green fluorescent protein (GFP) were grown in flow chambers with a defined minimal medium as substrate. Analysis by the COMSTAT program of four variables describing biofilm structure - mean thickness, roughness, substratum coverage and surface to volume ratio - showed that the four Pseudomonas: strains represent different modes of biofilm growth. P. putida had a unique developmental pattern starting with single cells on the substratum growing into micro-colonies, which were eventually succeeded by long filaments and elongated cell clusters. P. aeruginosa colonized the entire substratum, and formed flat, uniform biofilms. P. aureofaciens resembled P. aeruginosa, but had a stronger tendency to form micro-colonies. Finally, the biofilm structures of P. fluorescens had a phenotype intermediate between those of P. putida and P. aureofaciens. Analysis of biofilms of P. aureofaciens growing on 0.03 mM, 0.1 mM or 0.5 mM citrate minimal media showed that mean biofilm thickness increased with increasing citrate concentration. Moreover, biofilm roughness increased with lower citrate concentrations, whereas surface to volume ratio increased with higher citrate concentrations.

Dicty_cDB: Contig-U16487-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 2 ( DW406563 ) EST000984 Trichophyton rubrum cDNA library Tricho... 72 1e-17 4 ( FL496835 ) Mg_Nor01_07E06 Nor01 Myti... stress library Fra... 101 6e-18 3 ( DB668091 ) Saccharomyces cerevisiae mRNA, clon...isia annua normalized leaf... 62 2e-15 4 ( DW680253 ) EST003734 Trichophyton rubrum cDNA library 0 Tric... 7...R946874 ) EST1138413 Aquilegia cDNA library Aquilegia formo... 66 5e-10 2 ( FC787763 ) CBGC17953.fwd CBGC Lotti...:VS... 293 9e-75 1 ( DT758323 ) EST1192172 Aquilegia cDNA library Aquilegia formo

Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09.

Science.gov (United States)

Gharaie, Samareh; Vaas, Lea A I; Rosberg, Anna Karin; Windstam, Sofia T; Karlsson, Maria E; Bergstrand, Karl-Johan; Khalil, Sammar; Wohanka, Walter; Alsanius, Beatrix W

2017-01-01

Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm) and polychromatic (white: 350-990 nm) LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA). The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5-09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5-09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity.

Light spectrum modifies the utilization pattern of energy sources in Pseudomonas sp. DR 5-09.

Directory of Open Access Journals (Sweden)

Samareh Gharaie

Full Text Available Despite the overruling impact of light in the phyllosphere, little is known regarding the influence of light spectra on non-phototrophic bacteria colonizing the leaf surface. We developed an in vitro method to study phenotypic profile responses of bacterial pure cultures to different bands of the visible light spectrum using monochromatic (blue: 460 nm; red: 660 nm and polychromatic (white: 350-990 nm LEDs, by modification and optimization of a protocol for the Phenotype MicroArray™ technique (Biolog Inc., CA, USA. The new protocol revealed high reproducibility of substrate utilization under all conditions tested. Challenging the non-phototrophic bacterium Pseudomonas sp. DR 5-09 with white, blue, and red light demonstrated that all light treatments affected the respiratory profile differently, with blue LED having the most decisive impact on substrate utilization by impairing respiration of 140 substrates. The respiratory activity was decreased on 23 and 42 substrates under red and white LEDs, respectively, while utilization of one, 16, and 20 substrates increased in the presence of red, blue, and white LEDs, respectively. Interestingly, on four substrates contrasting utilization patterns were found when the bacterium was exposed to different light spectra. Although non-phototrophic bacteria do not rely directly on light as an energy source, Pseudomonas sp. DR 5-09 changed its respiratory activity on various substrates differently when exposed to different lights. Thus, ability to sense and distinguish between different wavelengths even within the visible light spectrum must exist, and leads to differential regulation of substrate usage. With these results, we hypothesize that different light spectra might be a hitherto neglected key stimulus for changes in microbial lifestyle and habits of substrate usage by non-phototrophic phyllospheric microbiota, and thus might essentially stratify leaf microbiota composition and diversity.

GenMapDB: a database of mapped human BAC clones

OpenAIRE

Morley, Michael; Arcaro, Melissa; Burdick, Joshua; Yonescu, Raluca; Reid, Thomas; Kirsch, Ilan R.; Cheung, Vivian G.

2001-01-01

GenMapDB (http://genomics.med.upenn.edu/genmapdb) is a repository of human bacterial artificial chromosome (BAC) clones mapped by our laboratory to sequence-tagged site markers. Currently, GenMapDB contains over 3000 mapped clones that span 19 chromosomes, chromosomes 2, 4, 5, 9–22, X and Y. This database provides positional information about human BAC clones from the RPCI-11 human male BAC library. It also contains restriction fragment analysis data and end sequen...

Effect of alternating and direct currents on Pseudomonas ...

African Journals Online (AJOL)

The test media were Muller-Hinton agar and eosin methylene blue (EMB) agar. In this research Pseudomonas aeruginosa which was isolated from patients wounds was examined with levels of alternating and direct current (AC and DC) electrical stimulation (1.5V, 3.5V, 5.5V and 10V) to see if these currents could inhibit P.

Effect of nutrients and fermentation conditions on the production of biosurfactants using rhizobacteria isolated from fique plants

Directory of Open Access Journals (Sweden)

Aura M. Pedroza-Rodríguez

2010-12-01

Full Text Available To isolate biosurfactant-producing microorganisms from the rhizosphere of fique and to select the best genus to evaluate theeffect of nutritional and fermentation conditions on the production of rhamnolipids. Materials and methods. Rhizospheric soil wassampled in three areas of Cauca. The best genus was selected for the experimental designs (Plackett Burman and 22 factorial and to find theproduction conditions for the growth kinetics at an Erlenmeyer flask scale. Results. Isolates from the rhizosphere of fique plants were fromgroups (or genera of Bacillus, Pseudomonas and Actinomycetes, being Pseudomonas the more responsive in preliminary testing foremulsification. From the results of the experimental designs and the kinetics of production, we found that rhamnose synthesis associatedwith rhamnolipids (3.2 g/l and emulsification (68% EC24 was significantly favored (p <0.0001 by cultivating an inoculum of 10% v/vof Pseudomonas fluorescens in a medium composed of: soybean oil 2% (v/v, K2HPO40.2% (w/v, yeast extract 0.4 g/l, NH4NO33.7 g/l, 1 ml trace elements (CoCl320 mg/l, H3BO330 mg/l, ZnSO410 mg/l, Cu2SO41 mg/l, Na2MoO43 mg/l, FeSO410 mg/l MnSO42,6 mg/l and pH 7.2. Conclusion. Of all the microbial genera isolated from the rhizosphere of fique, Pseudomonas fluorescens had the greatestpotential in the production of biosurfactants of the rhamnolipids family.

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.

Author Details

African Journals Online (AJOL)

Okolo, BN. Vol 15 (2011) - Articles Effects of Different Carbon Sources on Biosurfactant Production by a Pseudomonas fluorescens Isolate Abstract. ISSN: 1119-2283. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and ...

Protection of melon plants against Cucumber mosaic virus infection ...

African Journals Online (AJOL)

This study was carried out to characterize a virus causing severe mosaic, yellowing, stunting and leaf deformation on melon (Cucumis melo L.), and evaluate the capacity of Pseudomonas fluorescens as biofertilizer to improve plant growth and restrict the accumulation of the virus in the plant. The virus was identified as an ...

ANALYSIS OF MATERIALS IN AN EXPERIMENTAL TESTING PIPE SYSTEM FOR AN INHIBITOR OF MUSSEL KILL

Energy Technology Data Exchange (ETDEWEB)

Daniel P. Molloy

2003-06-04

A comprehensive series of 16 laboratory experiments demonstrated that the presence of vinyl tubing within a recirculating pipe system was responsible for lowering zebra mussel kill following treatment with the bacterium Pseudomonas fluorescens. All vinyl tubing was replaced in all testing units with silicone tubing, and high mussel kill (>95%) was then obtained.

1373-IJBCS-Article-Lamine Said Babamoussa

African Journals Online (AJOL)

KODJIO NORBERT

Les rhizobactéries Pseudomonas fluorescens ont induit le rendement de maïs le plus élevé, dépassant de ... Bacillus licheniformis, Bacillus lentus, Bacillus circulans, Bacillus firmus et Azospirillum ..... asiciadas al cultivo del maiz. ... bacteria and their inoculation effects on growth and nitrogen uptake of crop plants. J.

5-Aminolevulinic acid induced photodynamic inactivation on Staphylococcus aureus and Pseudomonas aeruginosa

Directory of Open Access Journals (Sweden)

Chien-Ming Hsieh

2014-09-01

Full Text Available The aim of the present study was to develop a simple and fast screening technique to directly evaluate the bactericidal effects of 5-aminolevulinic acid (ALA-mediated photodynamic inactivation (PDI and to determine the optimal antibacterial conditions of ALA concentrations and the total dosage of light in vitro. The effects of PDI on Staphylococcus aureus and Pseudomonas aeruginosa in the presence of various concentrations of ALA (1.0 mM, 2.5 mM, 5.0 mM, 10.0 mM were examined. All bacterial strains were exponentially grown in the culture medium at room temperature in the dark for 60 minutes and subsequently irradiated with 630 ± 5 nm using a light-emitting diode (LED red light device for accumulating the light doses up to 216 J/cm2. Both bacterial species were susceptible to the ALA-induced PDI. Photosensitization using 1.0 mM ALA with 162 J/cm2 light dose was able to completely reduce the viable counts of S. aureus. A significant decrease in the bacterial viabilities was observed for P. aeruginosa, where 5.0 mM ALA was photosensitized by accumulating the light dose of 162 J/cm2. We demonstrated that the use of microplate-based assays—by measuring the apparent optical density of bacterial colonies at 595 nm—was able to provide a simple and reliable approach for quickly choosing the parameters of ALA-mediated PDI in the cell suspensions.

5-Aminolevulinic acid induced photodynamic inactivation on Staphylococcus aureus and Pseudomonas aeruginosa.

Science.gov (United States)

Hsieh, Chien-Ming; Huang, Yen-Hao; Chen, Chueh-Pin; Hsieh, Bo-Chuan; Tsai, Tsuimin

2014-09-01

The aim of the present study was to develop a simple and fast screening technique to directly evaluate the bactericidal effects of 5-aminolevulinic acid (ALA)-mediated photodynamic inactivation (PDI) and to determine the optimal antibacterial conditions of ALA concentrations and the total dosage of light in vitro. The effects of PDI on Staphylococcus aureus and Pseudomonas aeruginosa in the presence of various concentrations of ALA (1.0 mM, 2.5 mM, 5.0 mM, 10.0 mM) were examined. All bacterial strains were exponentially grown in the culture medium at room temperature in the dark for 60 minutes and subsequently irradiated with 630 ± 5 nm using a light-emitting diode (LED) red light device for accumulating the light doses up to 216 J/cm 2 . Both bacterial species were susceptible to the ALA-induced PDI. Photosensitization using 1.0 mM ALA with 162 J/cm 2 light dose was able to completely reduce the viable counts of S. aureus. A significant decrease in the bacterial viabilities was observed for P. aeruginosa, where 5.0 mM ALA was photosensitized by accumulating the light dose of 162 J/cm 2 . We demonstrated that the use of microplate-based assays-by measuring the apparent optical density of bacterial colonies at 595 nm-was able to provide a simple and reliable approach for quickly choosing the parameters of ALA-mediated PDI in the cell suspensions. Copyright © 2013. Published by Elsevier B.V.

Isolation of Biosurfactant–Producing Bacteria with Antimicrobial Activity against Bacterial Pathogens

Directory of Open Access Journals (Sweden)

Siripun Sarin

2011-01-01

Full Text Available The aims of this research were to study biosurfactant producing bacteria isolated from soil and to determine their property and efficiency as biosurfactants in order to inhibit bacterial pathogens. The result showed that there were 8 bacterial isolates out of 136 isolates of the total biosurfactant producing bacteria screened that exhibited the diameter of clear zone more than 1.5 cm. in the oil spreading test. The highest potential of emulsifying activity (%EA24 of 54.4 and the maximum additive concentration, (%MAC of 24.2 was obtained from the fermentation broth of the G7 isolate which the G7 isolate was later identified as Pseudomonas fluorescens. Escherichia coli, Staphylococcus aureus and Psuedomonas aeruginosa were the tested bacterial pathogens that were most sensitive to the acid precipitated biosurfactant obtained from P. fluorescens G7 with the lowest minimum inhibitory concentration (MIC of 41.6 mg/ml and minimum bactericidal concentration (MBC of 41.6 mg/ml compared with the acid precipitated bisurfactants of the other isolates used in the antimicrobial activity test. The type of the separated crude biosurfactant produced by P. fluorescens G7 analyzed later by using the rhamose test, TLC and FT-IR techniques was rhamnolipid.

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).

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)).

DPP-4 inhibitor des-F-sitagliptin treatment increased insulin exocytosis from db/db mice {beta} cells

Energy Technology Data Exchange (ETDEWEB)

Nagamatsu, Shinya, E-mail: shinya@ks.kyorin-u.ac.jp [Department of Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo 181-8611 (Japan); Ohara-Imaizumi, Mica; Nakamichi, Yoko; Aoyagi, Kyota; Nishiwaki, Chiyono [Department of Biochemistry, Kyorin University School of Medicine, Mitaka, Tokyo 181-8611 (Japan)

2011-09-09

Highlights: {yields} Anti-diabetic new drug, DPP-4 inhibitor, can affect the insulin exocytosis. {yields} DPP-4 inhibitor treatment altered syntaxin 1 expression. {yields} Treatment of db/db mice with DPP-4 inhibitor increased insulin release. -- Abstract: Incretin promotes insulin secretion acutely. Recently, orally-administered DPP-4 inhibitors represent a new class of anti-hyperglycemic agents. Indeed, inhibitors of dipeptidyl peptidase-IV (DPP-4), sitagliptin, has just begun to be widely used as therapeutics for type 2 diabetes. However, the effects of sitagliptin-treatment on insulin exocytosis from single {beta}-cells are yet unknown. We therefore investigated how sitagliptin-treatment in db/db mice affects insulin exocytosis by treating db/db mice with des-F-sitagliptin for 2 weeks. Perfusion studies showed that 2 weeks-sitagliptin treatment potentiated insulin secretion. We then analyzed insulin granule motion and SNARE protein, syntaxin 1, by TIRF imaging system. TIRF imaging of insulin exocytosis showed the increased number of docked insulin granules and increased fusion events from them during first-phase release. In accord with insulin exocytosis data, des-F-sitagliptin-treatment increased the number of syntaxin 1 clusters on the plasma membrane. Thus, our data demonstrated that 2-weeks des-F-sitagliptin-treatment increased the fusion events of insulin granules, probably via increased number of docked insulin granules and that of syntaxin 1 clusters.

Characterization of CMR5c and CMR12a, novel fluorescent Pseudomonas strains from the cocoyam rhizosphere with biocontrol activity

NARCIS (Netherlands)

Perneel, M.; Heyrman, J.; Adiobo, A.; Maeyer, de K.; Raaijmakers, J.M.; Vos, de P.; Höfte, M.

2007-01-01

Aim: To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum. Material and Results: Forty pseudomonads were isolated from the rhizosphere

Tangshen Formula Attenuates Diabetic Nephropathy by Promoting ABCA1-Mediated Renal Cholesterol Efflux in db/db Mice.

Science.gov (United States)

Liu, Peng; Peng, Liang; Zhang, Haojun; Tang, Patrick Ming-Kuen; Zhao, Tingting; Yan, Meihua; Zhao, Hailing; Huang, Xiaoru; Lan, Huiyao; Li, Ping

2018-01-01

The commonly prescribed Tangshen Formula (TSF) is a traditional Chinese formulation that has been shown to reduce plasma lipid metabolism and proteinuria and improve the estimated glomerular filtration rate (eGFR) in patients with diabetic kidney disease. This study investigated the underlying mechanism whereby TSF regulates renal lipid accumulation and ameliorates diabetic renal injuries in spontaneous diabetic db/db mice and in vitro in sodium palmitate (PA)-stimulated and Abca1-SiRNA-transfected mouse tubular epithelial cells (mTECs). The results revealed that TSF treatment significantly ameliorated the renal injuries by lowering urinary albumin excretion and improving renal tissue injuries in diabetic (db/db) mice. Interestingly, the treatment with TSF also resulted in decreased cholesterol levels in the renal tissues of db/db mice, which was associated with increased expression of the peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α), the Liver X receptors (LXR), and ATP-binding cassette subfamily A member 1 (ABCA1), suggesting that TSF might attenuate diabetic kidney injury via a mechanism associated with improving cholesterol efflux in the diabetic kidney. This was investigated in vitro in mTECs, and the results showed that TSF reduced the PA-stimulated cholesterol accumulation in mTECs. Mechanistically, the addition of TSF was capable of reversing PA-induced downregulation of PGC-1α, LXR, and ABCA1 expression and cholesterol accumulation in mTECs, suggesting that TSF might act the protection via the PGC-1α-LXR-ABCA1 pathway to improve the cholesterol efflux in the renal tissues of db/db mice. This was further confirmed by silencing ABCA1 to block the promotive effect of TSF on cholesterol efflux in vitro . In conclusion, TSF might ameliorate diabetic kidney injuries by promoting ABCA1-mediated renal cholesterol efflux.

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...

ToxRefDB - Release user-friendly web-based tool for mining ToxRefDB

Science.gov (United States)

The updated URL link is for a table of NCCT ToxCast public datasets. The next to last row of the table has the link for the US EPA ToxCast ToxRefDB Data Release October 2014. ToxRefDB provides detailed chemical toxicity data in a publically accessible searchable format. ToxRefD...

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)

An inter-species signaling system mediated by fusaric acid has parallel effects on antifungal metabolite production by Pseudomonas protegens Pf-5 and antibiosis of Fusarium spp.

Science.gov (United States)

Pseudomonas protegens strain Pf-5 is a rhizosphere bacterium that acts as a biocontrol agent of soilborne plant diseases, and produces at least seven different secondary metabolites with antifungal properties. We derived site-directed mutants of Pf-5 with single and multiple mutations in the biosynt...

Analysis of neuron–astrocyte metabolic cooperation in the brain of db/db mice with cognitive decline using 13C NMR spectroscopy

Science.gov (United States)

Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian

2016-01-01

Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron–astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m+/+ Leprdb/J) mice with cognitive decline using 13C NMR technique in combination with intravenous [2-13C]-acetate and [3-13C]-lactate infusions. We found that the 13C-enrichment from [2-13C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3-13C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2-13C]-acetate infusion. However, [3-13C]-lactate resulted in increased 13C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron–astrocyte cooperation and an enhancement of gluconeogenesis. PMID:26762505

Analysis of neuron-astrocyte metabolic cooperation in the brain of db/db mice with cognitive decline using 13C NMR spectroscopy.

Science.gov (United States)

Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian; Gao, Hongchang

2017-01-01

Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron-astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m +/+ Leprdb/J) mice with cognitive decline using 13 C NMR technique in combination with intravenous [2- 13 C]-acetate and [3- 13 C]-lactate infusions. We found that the 13 C-enrichment from [2- 13 C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3- 13 C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13 C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2- 13 C]-acetate infusion. However, [3- 13 C]-lactate resulted in increased 13 C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13 C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron-astrocyte cooperation and an enhancement of gluconeogenesis. © The Author(s) 2016.

Getting started with LevelDB

CERN Document Server

Dent, Andy

2013-01-01

The book is a concise guide for using LevelDB. It explains database concepts and the use of C++, ranging from the basics all the way to high level topics in an easy to follow, step-by-step format.The book is meant for developers who want an embedded database for their applications. Experienced programmers can pick up on the sophisticated data mapping patterns and tuning tips.Getting Started with LevelDB requires a minimal background in programming in C++ or Objective-C for OS/X or iOS and familiarity with XCode. Therefore it teaches enough C++ to use LevelDB without presuming any C++ knowledge

Effect of Application of Pseudomonas fluorescent Strains on Yield and Yield Components of Rapeseed Cultivars

Directory of Open Access Journals (Sweden)

R Najafi

2015-09-01

Full Text Available Plant growth promoting rhizobacteria has been identified as an alternative to chemical fertilizer to enhance plant growth and yield directly and indirectly. Use of rhizosphere free living bacteria is one of the methods for crop production and leads to improvement of resources absorption. In order to study of yield, yield components and radiation use efficiency, under application of PGPR condition, an experiment was carried out in 2008 growing season at Agriculture and natural resources research station of Mashhad. The cultivars selected from three rapeseed species belong to Brassica napus, Brassica rapa and Brassica juncea (landrace, BP.18، Goldrush، Parkland، Hyola330، Hyola401. Experimental factorial design was randomized in complete block with three replications. Treatments included six varieties of Rapeseed and inoculations were four levels as non–inoculation, inoculation with P. fluorescens169, P. putida108 and use then together. Results showed that strains of fluorescent pseudomonas bacteria had greatest effects on yield and yield components cultivars. A significant difference in the number of pods per plant and 1000 seed weight observed. The cultivars were different in all treats except 1000 seed weight. Overall results indicated that application of growth stimulating bacteria in combination with different cultivars, had a positive effect growth, yield characteristics of plant varieties of rapeseed plants.

dbVar

Data.gov (United States)

U.S. Department of Health & Human Services — dbVar is a database of genomic structural variation. It accepts data from all species and includes clinical data. It can accept diverse types of events, including...

Flow cytometry analysis reveals different activation profiles of thrombin- or TRAP-stimulated platelets in db/db mice. The regulatory role of PAR-3.

Science.gov (United States)

Kassassir, Hassan; Siewiera, Karolina; Talar, Marcin; Przygodzki, Tomasz; Watala, Cezary

2017-06-01

Recent studies have shown that it may be the concentration of thrombin, which is discriminative in determining of the mechanism of platelet activation via protease activated receptors (PARs). Whether the observed phenomenon of differentiated responses of mouse platelets to various thrombin concentrations in non-diabetic db/+ and diabetic db/db mice depends upon the concerted action of various PARs, remains to be established. We found elevated reactivity of platelets, as well as the enhanced PAR-3 expression in response to both the used concentrations of AYPGKF in db/db mice, as compared to db/+ heterozygotes. At low concentration of thrombin platelets from diabetic mice demonstrated hyperreactivity, reflected by higher expression of PAR-3. For higher thrombin concentration, blood platelets from db/db mice appeared hyporeactive, compared to db/+ animals, while no significant differences in PAR-3 expression were observed between diabetic and non-diabetic mice. The novel and previously unreported finding resulting from our study is that the increased expression of PAR-3 in response to either TRAP for PAR-4 or low thrombin (when PAR-4 is not the efficient thrombin receptor) may be one of the key events contributing to higher reactivity of platelets in db/db mice. Copyright © 2017 Elsevier Inc. All rights reserved.

Plant growth promotion rhizobacteria in onion production.

Science.gov (United States)

Colo, Josip; Hajnal-Jafari, Timea I; Durić, Simonida; Stamenov, Dragana; Hamidović, Saud

2014-01-01

The aim of the research was to examine the effect of rhizospheric bacteria Azotobacter chroococcum, Pseudomonas fluorescens (strains 1 and 2) and Bacillus subtilis on the growth and yield of onion and on the microorganisms in the rhizosphere of onion. The ability of microorganisms to produce indole-acetic acid (IAA), siderophores and to solubilize tricalcium phosphate (TCP) was also assessed. The experiment was conducted in field conditions, in chernozem type of soil. Bacillus subtilis was the best producer of IAA, whereas Pseudomonas fluorescens strains were better at producing siderophores and solubilizing phosphates. The longest seedling was observed with the application of Azotobacter chroococcum. The height of the plants sixty days after sowing was greater in all the inoculated variants than in the control. The highest onion yield was observed in Bacillus subtilis and Azotobacter chroococcum variants. The total number of bacteria and the number of Azotobacter chroococcum were larger in all the inoculated variants then in the control. The number of fungi decreased in most of the inoculated variants, whereas the number of actinomycetes decreased or remained the same.

"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 ...

Interactions of rare earth elements with bacteria and organic ligands

International Nuclear Information System (INIS)

Ozaki, Takuo; Suzuki, Yoshinori; Nankawa, Takuya; Yoshida, Takahiro; Ohnuki, Toshihiko; Kimura, Takaumi; Francis, Arokiasamy J.

2006-01-01

We investigated the interactions of rare earth elements (REEs) Eu(III) and/or Ce(III, IV) with the common soil bacterium Pseudomonas fluorescens and organic ligands, such as malic acid, citric acid, a siderophore (DFO), cellulose, chitin, and chitosan. Malic acid formed complexes with Eu(III), but degradation of malic acid was observed when the ratio of malic acid to Eu(III) was higher than 100. Citric acid formed a stoichiometric complex with Eu(III) that was not degraded by P. fluorescens. Adsorption of Eu(III) from the DFO complex occurred as a free ion dissociated from DFO and not as the Eu(III)-DFO complex. Cerium(III) was oxidized to Ce(IV) during complexation with DFO to form the Ce(IV)-DFO complex. Time-resolved laser-induced fluorescence spectroscopy (TRLFS) analysis showed that cellulose, chitin, and chitosan, respectively, formed a weak complex, an inner-spherical complex, and an outer-spherical complex with Eu(III). This method also demonstrated that the coordination environment of Eu(III) adsorbed on P. fluorescens possessed similar characteristics to that of chitin, and revealed that adsorption of Eu(III) on P. fluorescens was through a multidentate and predominantly inner-spherical coordination

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.

Night-time restricted feeding normalises clock genes and Pai-1 gene expression in the db/db mouse liver.

Science.gov (United States)

Kudo, T; Akiyama, M; Kuriyama, K; Sudo, M; Moriya, T; Shibata, S

2004-08-01

An increase in PAI-1 activity is thought to be a key factor underlying myocardial infarction. Mouse Pai-1 (mPai-1) activity shows a daily rhythm in vivo, and its transcription seems to be controlled not only by clock genes but also by humoral factors such as insulin and triglycerides. Thus, we investigated daily clock genes and mPai-1 mRNA expression in the liver of db/db mice exhibiting high levels of glucose, insulin and triglycerides. Locomotor activity was measured using an infrared detection system. RT-PCR or in situ hybridisation methods were applied to measure gene expression. Humoral factors were measured using measurement kits. The db/ db mice showed attenuated locomotor activity rhythms. The rhythmic expression of mPer2 mRNA was severely diminished and the phase of mBmal1 oscillation was advanced in the db/db mouse liver, whereas mPai-1 mRNA was highly and constitutively expressed. Night-time restricted feeding led to a recovery not only from the diminished locomotor activity, but also from the diminished Per2 and advanced mBmal1 mRNA rhythms. Expression of mPai-1 mRNA in db/db mice was reduced to levels far below normal. Pioglitazone treatment slightly normalised glucose and insulin levels, with a slight reduction in mPai-1 gene expression. We demonstrated that Type 2 diabetes impairs the oscillation of the peripheral oscillator. Night-time restricted feeding rather than pioglitazone injection led to a recovery from the diminished locomotor activity, and altered oscillation of the peripheral clock and mPai-1 mRNA rhythm. Thus, we conclude that scheduled restricted food intake may be a useful form of treatment for diabetes.

Identification of a Signal That Mediates the Crosstalk Between Biosynthetic Gene Clusters for the Antibiotics 2,4-diacetylphloroglucinol and Pyoluteorin in Pseudomonas protegens Pf-5

Science.gov (United States)

Pseudomonas protegens Pf-5 produces a broad spectrum of secondary metabolites with anti-microbial activity. The production of two of these metabolites, 2,4-diacetylphloroglucinol (DAPG) and pyoluteorin, is coordinately regulated. Our previous study indicated that phloroglucinol, an intermediate in t...

GC/TOFMS analysis of metabolites in serum and urine reveals metabolic perturbation of TCA cycle in db/db mice involved in diabetic nephropathy.

Science.gov (United States)

Li, Mengjie; Wang, Xufang; Aa, Jiye; Qin, Weisong; Zha, Weibin; Ge, Yongchun; Liu, Linsheng; Zheng, Tian; Cao, Bei; Shi, Jian; Zhao, Chunyan; Wang, Xinwen; Yu, Xiaoyi; Wang, Guangji; Liu, Zhihong

2013-06-01

Early diagnosis of diabetic nephropathy (DN) is difficult although it is of crucial importance to prevent its development. To probe potential markers and the underlying mechanism of DN, an animal model of DN, the db/db mice, was used and serum and urine metabolites were profiled using gas chromatography/time-of-flight mass spectrometry. Metabolic patterns were evaluated based on serum and urine data. Principal component analysis of the data revealed an obvious metabonomic difference between db/db mice and controls, and db/db mice showed distinctly different metabolic patterns during the progression from diabetes to early, medium, and later DN. The identified metabolites discriminating between db/db mice and controls suggested that db/db mice have perturbations in the tricarboxylic acid cycle (TCA, citrate, malate, succinate, and aconitate), lipid metabolism, glycolysis, and amino acid turnover. The db/db mice were characterized by acidic urine, high TCA intermediates in serum at week 6 and a sharp decline thereafter, and gradual elevation of free fatty acids in the serum. The sharp drop of serum TCA intermediates from week 6 to 8 indicated the downregulated glycolysis and insulin resistance. However, urinary TCA intermediates did not decrease in parallel with those in the serum from week 6 to 10, and an increased portion of TCA intermediates in the serum was excreted into the urine at 8, 10, and 12 wk than at 6 wk, indicating kidney dysfunction occurred. The relative abundances of TCA intermediates in urine relative to those in serum were suggested as an index of renal damage.

Differential Proteomic Analysis of the Pancreas of Diabetic db/db Mice Reveals the Proteins Involved in the Development of Complications of Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Victoriano Pérez-Vázquez

2014-05-01

Full Text Available Type 2 diabetes mellitus is characterized by hyperglycemia and insulin-resistance. Diabetes results from pancreatic inability to secrete the insulin needed to overcome this resistance. We analyzed the protein profile from the pancreas of ten-week old diabetic db/db and wild type mice through proteomics. Pancreatic proteins were separated in two-dimensional polyacrylamide gel electrophoresis (2D-PAGE and significant changes in db/db mice respect to wild type mice were observed in 27 proteins. Twenty five proteins were identified by matrix-assisted laser desorption/ionization (MALDI time-of-flight (TOF and their interactions were analyzed using search tool for the retrieval of interacting genes/proteins (STRING and database for annotation, visualization and integrated discovery (DAVID. Some of these proteins were Pancreatic α-amylase, Cytochrome b5, Lithostathine-1, Lithostathine-2, Chymotrypsinogen B, Peroxiredoxin-4, Aspartyl aminopeptidase, Endoplasmin, and others, which are involved in the metabolism of carbohydrates and proteins, as well as in oxidative stress, and inflammation. Remarkably, these are mostly endoplasmic reticulum proteins related to peptidase activity, i.e., they are involved in proteolysis, glucose catabolism and in the tumor necrosis factor-mediated signaling pathway. These results suggest mechanisms for insulin resistance, and the chronic inflammatory state observed in diabetes.

Getting started with OrientDB

CERN Document Server

Tesoriero, Claudio

2013-01-01

A standard tutorial aimed at making you an OrientDB expert, through the use of practical examples, explained in a step-by-step format.Getting Started with OrientDB 1.3.0 is great for database designers, developers, and systems engineers. It is assumed that you are familiar with NoSQL concepts, Java, and networking principles.

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...

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.

Integrated effect of gamma radiation and biocontrol agent on quality parameters of apple fruit: An innovative commercial preservation method

Science.gov (United States)

Ahari Mostafavi, Hossein; Mahyar Mirmajlessi, Seyed; Fathollahi, Hadi; Shahbazi, Samira; Mohammad Mirjalili, Seyed

2013-10-01

Effects of gamma irradiation and biocontrol agent (Pseudomonas fluorescens) on the physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Golden Delicious apples were investigated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 200, 400, 600 and 800 Gy and then inoculated with P. fluorescens suspension. Samples were evaluated at 3 month intervals. The results demonstrated a clear link between antioxidant activity and phenolic content, so that dose range of 200-400 Gy significantly increased phenolic content and antioxidant activity. Effect of P. fluorescens was similar to irradiation at 200 and 400 Gy that could prevent lesion diameter in pathogen-treated apples. As dose and storage time increased firmness decreased but, combination of P. fluorescens as well as irradiation (at 200-400 Gy) could decrease softening apple fruits during storage. In all parameters, P. fluorescens (as biocontrol agent) inhibited P. expansum similar to irradiation at 200-400 Gy. So, integrated treatment of irradiation and biocontrol agent explored the potential dual benefit of low doses (200 and 400 Gy) as a suitable method to sustain physico-chemical quality and conclusively reduce apple fruits losses during post-harvest preservation.

Overactivity of Liver-Related Neurons in the Paraventricular Nucleus of the Hypothalamus: Electrophysiological Findings in db/db Mice.

Science.gov (United States)

Gao, Hong; Molinas, Adrien J R; Miyata, Kayoko; Qiao, Xin; Zsombok, Andrea

2017-11-15

Preautonomic neurons in the paraventricular nucleus (PVN) of the hypothalamus play a large role in the regulation of hepatic functions via the autonomic nervous system. Activation of hepatic sympathetic nerves increases glucose and lipid metabolism and contributes to the elevated hepatic glucose production observed in the type 2 diabetic condition. This augmented sympathetic output could originate from altered activity of liver-related PVN neurons. Remarkably, despite the importance of the brain-liver pathway, the cellular properties of liver-related neurons are not known. In this study, we provide the first evidence of overall activity of liver-related PVN neurons. Liver-related PVN neurons were identified with a retrograde, trans-synaptic, viral tracer in male lean and db/db mice and whole-cell patch-clamp recordings were conducted. In db/db mice, the majority of liver-related PVN neurons fired spontaneously; whereas, in lean mice the majority of liver-related PVN neurons were silent, indicating that liver-related PVN neurons are more active in db/db mice. Persistent, tonic inhibition was identified in liver-related PVN neurons; although, the magnitude of tonic inhibitory control was not different between lean and db/db mice. In addition, our study revealed that the transient receptor potential vanilloid type 1-dependent increase of excitatory neurotransmission was reduced in liver-related PVN neurons of db/db mice. These findings demonstrate plasticity of liver-related PVN neurons and a shift toward excitation in a diabetic mouse model. Our study suggests altered autonomic circuits at the level of the PVN, which can contribute to autonomic dysfunction and dysregulation of neural control of hepatic functions including glucose metabolism. SIGNIFICANCE STATEMENT A growing body of evidence suggests the importance of the autonomic control in the regulation of hepatic metabolism, which plays a major role in the development and progression of type 2 diabetes mellitus

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...

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.

Pitavastatin suppresses diethylnitrosamine-induced liver preneoplasms in male C57BL/KsJ-db/db obese mice

International Nuclear Information System (INIS)

Shimizu, Masahito; Tanaka, Takuji; Moriwaki, Hisataka; Yasuda, Yoichi; Sakai, Hiroyasu; Kubota, Masaya; Terakura, Daishi; Baba, Atsushi; Ohno, Tomohiko; Kochi, Takahiro; Tsurumi, Hisashi

2011-01-01

Obesity and related metabolic abnormalities, including inflammation and lipid accumulation in the liver, play a role in liver carcinogenesis. Adipocytokine imbalances, such as decreased serum adiponectin levels, are also involved in obesity-related liver tumorigenesis. In the present study, we examined the effects of pitavastatin - a drug used for the treatment of hyperlipidemia - on the development of diethylnitrosamine (DEN)-induced liver preneoplastic lesions in C57BL/KsJ-db/db (db/db) obese mice. Male db/db mice were administered tap water containing 40 ppm DEN for 2 weeks and were subsequently fed a diet containing 1 ppm or 10 ppm pitavastatin for 14 weeks. At sacrifice, feeding with 10 ppm pitavastatin significantly inhibited the development of hepatic premalignant lesions, foci of cellular alteration, as compared to that in the untreated group by inducing apoptosis, but inhibiting cell proliferation. Pitavastatin improved liver steatosis and activated the AMPK-α protein in the liver. It also decreased free fatty acid and aminotransferases levels, while increasing adiponectin levels in the serum. The serum levels of tumor necrosis factor (TNF)-α and the expression of TNF-α and interleukin-6 mRNAs in the liver were decreased by pitavastatin treatment, suggesting attenuation of the chronic inflammation induced by excess fat deposition. Pitavastatin is effective in inhibiting the early phase of obesity-related liver tumorigenesis and, therefore, may be useful in the chemoprevention of liver cancer in obese individuals

Dysregulation of the unfolded protein response in db/db mice with diet induced steatohepatitis

OpenAIRE

Rinella, Mary E.; Siddiqui, M. Shaddab; Gardikiotes, Konstantina; Gottstein, Jeanne; Elias, Marc; Green, Richard M.

2011-01-01

In humans with non-alcoholic fatty liver, diabetes is associated with more advanced disease. We have previously shown that diabetic db/db mice are highly susceptible to methionine choline deficient diet (MCD) induced hepatic injury. Since activation of the unfolded protein response (UPR) is an important adaptive cellular mechanism in diabetes, obesity and fatty liver, we hypothesized that dysregulation of the UPR may partially explain how diabetes could promote liver injury.

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.

Novel anti-diabetic effect of SCM-198 via inhibiting the hepatic NF-κB pathway in db/db mice.

Science.gov (United States)

Huang, Hui; Xin, Hong; Liu, Xinhua; Xu, Yajun; Wen, Danyi; Zhang, Yahua; Zhu, Yi Zhun

2012-04-01

There are reports of early evidence that suggest the involvement of chronic low-grade inflammation in the pathogenesis of Type 2 diabetes. Thus, substances that have effects in reducing inflammation could be potential drugs for Type 2 diabetes. Leonurine (4-guanidino-n-butyl syringate; SCM-198) is an alkaloid in HL (Herba leonuri), which was reported to possess anti-inflammatory properties. We hypothesize that SCM-198 may have beneficial effects on Type 2 diabetes. In the present study, we attempted to test this hypothesis by evaluating the anti-diabetic effect of SCM-198 and the possible underlying mechanisms of its effects in db/db mice. SCM-198 (50, 100 and 200 mg/kg of body weight), pioglitazone (50 mg/kg of body weight, as a positive control) or 1% CMC-Na (sodium carboxymethylcellulose) were administered to the db/db or db/m mice once daily for 3 weeks. After 3 weeks, SCM-198 (200 mg/kg of body weight) treatment significantly reduced the fasting blood glucose level and increased the plasma insulin concentration in the db/db mice, meanwhile it significantly lowered the plasma TAG (triacylglycerol) concentration and increased the HDL (high-density lipoprotein)-cholesterol concentration. Moreover, the dysregulated transcription of the hepatic glucose metabolic enzymes, including GK (glucokinase), G6Pase (glucose-6-phosphatase) and PEPCK (phosphoenolpyruvate carboxykinase), was recovered by an Akt-dependent pathway. The pro-inflammatory mediators {such as TNFα (tumour necrosis factor α), IL (interleukin)-6, IL-1β, degradation of IκB [inhibitor of NF-κB (nuclear factor-κB)] α and thereafter activation of NF-κB} were reversed by SCM-198 treatment in the db/db mice. The present study provides first evidence that SCM-198 exhibits anti-inflammatory activity and has an ameliorating effect on diabetic symptoms via inhibiting of NF-κB/IKK (IκB kinase) pathway. Consequently, we suggest that SCM-198 may be a prospective agent for prevention and

Pluronic L-81 ameliorates diabetic symptoms in db/db mice through transcriptional regulation of microsomal triglyceride transfer protein

Science.gov (United States)

Au, Wo-Shing; Lu, Li-Wei; Tam, Sidney; Ko, Otis King Hung; Chow, Billy KC; He, Ming-Liang; Ng, Samuel S; Yeung, Chung-Man; Liu, Ching-Chiu; Kung, Hsiang-Fu; Lin, Marie C

2009-01-01

AIM: To test whether oral L-81 treatment could improve the condition of mice with diabetes and to investigate how L-81 regulates microsomal triglyceride transfer protein (MTP) activity in the liver. METHODS: Genetically diabetic (db/db) mice were fed on chow supplemented with or without L-81 for 4 wk. The body weight, plasma glucose level, plasma lipid profile, and adipocyte volume of the db/db mice were assessed after treatment. Toxicity of L-81 was also evaluated. To understand the molecular mechanism, HepG2 cells were treated with L-81 and the effects on apolipoprotein B (apoB) secretion and mRNA level of the MTP gene were assessed. RESULTS: Treatment of db/db mice with L-81 significantly reduced and nearly normalized their body weight, hyperphagia and polydipsia. L-81 also markedly decreased the fasting plasma glucose level, improved glucose tolerance, and attenuated the elevated levels of plasma cholesterol and triglyceride. At the effective dosage, little toxicity was observed. Treatment of HepG2 cells with L-81 not only inhibited apoB secretion, but also significantly decreased the mRNA level of the MTP gene. Similar to the action of insulin, L-81 exerted its effect on the MTP promoter. CONCLUSION: L-81 represents a promising candidate in the development of a selective insulin-mimetic molecule and an anti-diabetic agent. PMID:19554651