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Sample records for rhizobium etli final

  1. Metabolic Reconstruction and Modeling of Nitrogen Fixation in Rhizobium etli

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    Resendis-antonio, Osbaldo; Reed, Jennifer L.; Encarnacio?n, Sergio; Collado-vides, Julio; Palsson, Bernhard Ø.

    2007-01-01

    Rhizobiaceas are bacteria that fix nitrogen during symbiosis with plants. This symbiotic relationship is crucial for the nitrogen cycle, and understanding symbiotic mechanisms is a scientific challenge with direct applications in agronomy and plant development. Rhizobium etli is a bacteria which provides legumes with ammonia (among other chemical compounds), thereby stimulating plant growth. A genome-scale approach, integrating the biochemical information available for R. etli, constitutes an...

  2. Role of trehalose in heat and desiccation tolerance in the soil bacterium Rhizobium etli

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    Reina-Bueno Mercedes; Argandoña Montserrat; Nieto Joaquín J; Hidalgo-García Alba; Iglesias-Guerra Fernando; Delgado María J; Vargas Carmen

    2012-01-01

    Abstract Background The compatible solute trehalose is involved in the osmostress response of Rhizobium etli, the microsymbiont of Phaseolus vulgaris. In this work, we reconstructed trehalose metabolism in R. etli, and investigated its role in cellular adaptation and survival to heat and desiccation stress under free living conditions. Results Besides trehalose as major compatible solute, R. etli CE3 also accumulated glutamate and, if present in the medium, mannitol. Putative genes for trehal...

  3. Genomic lineages of Rhizobium etli revealed by the extent of nucleotide polymorphisms and low recombination

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    González Víctor

    2011-10-01

    Full Text Available Abstract Background Most of the DNA variations found in bacterial species are in the form of single nucleotide polymorphisms (SNPs, but there is some debate regarding how much of this variation comes from mutation versus recombination. The nitrogen-fixing symbiotic bacteria Rhizobium etli is highly variable in both genomic structure and gene content. However, no previous report has provided a detailed genomic analysis of this variation at nucleotide level or the role of recombination in generating diversity in this bacterium. Here, we compared draft genomic sequences versus complete genomic sequences to obtain reliable measures of genetic diversity and then estimated the role of recombination in the generation of genomic diversity among Rhizobium etli. Results We identified high levels of DNA polymorphism in R. etli, and found that there was an average divergence of 4% to 6% among the tested strain pairs. DNA recombination events were estimated to affect 3% to 10% of the genomic sample analyzed. In most instances, the nucleotide diversity (? was greater in DNA segments with recombinant events than in non-recombinant segments. However, this degree of recombination was not sufficiently large to disrupt the congruence of the phylogenetic trees, and further evaluation of recombination in strains quartets indicated that the recombination levels in this species are proportionally low. Conclusion Our data suggest that R. etli is a species composed of separated lineages with low homologous recombination among the strains. Horizontal gene transfer, particularly via the symbiotic plasmid characteristic of this species, seems to play an important role in diversity but the lineages maintain their evolutionary cohesiveness.

  4. The arginine deiminase pathway in Rhizobium etli: DNA sequence analysis and functional study of the arcABC genes.

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    D'Hooghe, I; Vander Wauven, C; Michiels, J; Tricot, C.; Wilde, P. de; Vanderleyden, J.; Stalon, V.

    1997-01-01

    Sequence analysis upstream of the Rhizobium etli fixLJ homologous genes revealed the presence of three open reading frames homologous to the arcABC genes of Pseudomonas aeruginosa. The P. aeruginosa arcABC genes code for the enzymes of the arginine deiminase pathway: arginine deiminase, catabolic ornithine carbamoyltransferase (cOTCase), and carbamate kinase. OTCase activities were measured in free-living R. etli cells and in bacteroids isolated from bean nodules. OTCase activity in free-livi...

  5. Interaction Between the Biotin Carboxyl Carrier Domain and the Biotin Carboxylase Domain in Pyruvate Carboxylase from Rhizobium etli

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    Lietzan, Adam D.; Menefee, Ann L.; Zeczycki, Tonya N.; Kumar, Sudhanshu; Attwood, Paul V.; Wallace, John C; Cleland, W. Wallace; Maurice, Martin St

    2011-01-01

    Pyruvate carboxylase (PC) catalyzes the ATP-dependent carboxylation of pyruvate to oxaloacetate, an important anaplerotic reaction in mammalian tissues. To effect catalysis, the tethered biotin of PC must gain access to active sites in both the biotin carboxylase domain and the carboxyl transferase domain. Previous studies have demonstrated that a mutation of threonine 882 to alanine in PC from Rhizobium etli renders the carboxyl transferase domain inactive and favors the positioning of bioti...

  6. The extracellular proteome of Rhizobium etli CE3 in exponential and stationary growth phase

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    Mendoza-Hernández Guillermo

    2010-10-01

    Full Text Available Abstract Background The extracellular proteome or secretome of symbiotic bacteria like Rhizobium etli is presumed to be a key element of their infection strategy and survival. Rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. To find out the possible role of secreted proteins we analyzed the extracellular proteome of R. etli CE3 in the exponential and stationary growth phases in minimal medium, supplemented with succinate-ammonium. Results The extracellular proteins were obtained by phenol extraction and identified by LC-ESI MS/MS. We identified 192 and 191 proteins for the exponential and stationary phases respectively. Using the software Signal P, we predicted signal peptides for 12.95% and 35.60% of the proteins identified in the exponential and stationary phases, respectively, which could therefore be secreted by the Sec pathway. For the exponential growth phase, we found in abundance proteins like the ribosomal proteins, toxins and proteins belonging to the group "defence mechanisms". For the stationary growth phase, we found that the most abundant proteins were those with unknown function, and in many of these we identified characteristic domains of proteases and peptidases. Conclusions Our study provided the first dataset of the secretome of R. etli and its modifications, which may lead to novel insights into the adaptive response of different stages of growth. In addition, we found a high number of proteins with unknown function; these proteins could be analyzed in future research to elucidate their role in the extracellular proteome of R. etli.

  7. Pleiotropic effects of a rel mutation on stress survival of Rhizobium etli CNPAF512

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    Beullens Serge

    2008-12-01

    Full Text Available Abstract Background The rel gene of Rhizobium etli (relRet, the nodulating endosymbiont of the common bean plant, determines the cellular level of the alarmone (pppGpp and was previously shown to affect free-living growth and symbiosis. Here, we demonstrate its role in cellular adaptation and survival in response to various stresses. Results Growth of the R. etli relRet mutant was strongly reduced or abolished in the presence of elevated NaCl levels or at 37°C, compared to the wild type. In addition, depending on the cell density, decreased survival of exponentially growing or stationary phase relRet mutant cells was obtained after H2O2, heat or NaCl shock compared to the wild-type strain. Survival of unstressed stationary phase cultures was differentially affected depending on the growth medium used. Colony forming units (CFU of relRet mutant cultures continuously decreased in minimal medium supplemented with succinate, whereas wild-type cultures stabilised at higher CFU levels. Microscopic examination of stationary phase cells indicated that the relRet mutant was unable to reach the typical coccoid morphology of the wild type in stationary phase cultures. Assessment of stress resistance of re-isolated bacteroids showed increased sensitivity of the relRet mutant to H2O2 and a slightly increased resistance to elevated temperature (45°C or NaCl shock, compared to wild-type bacteroids. Conclusion The relRet gene is an important factor in regulating rhizobial physiology, during free-living growth as well as in symbiotic conditions. Additionally, differential responses to several stresses applied to bacteroids and free-living exponential or stationary phase cells point to essential physiological differences between the different states.

  8. Covalent immobilization of recombinant Rhizobium etli CFN42 xylitol dehydrogenase onto modified silica nanoparticles.

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    Zhang, Ye-Wang; Tiwari, Manish Kumar; Jeya, Marimuthu; Lee, Jung-Kul

    2011-04-01

    Rare sugars have many applications in food industry, as well as pharmaceutical and nutrition industries. Xylitol dehydrogenase (XDH) can be used to synthesize various rare sugars enzymatically. However, the immobilization of XDH has not been performed to improve the industrial production of rare sugars. In this study, silica nanoparticles which have high immobilization efficiency were selected from among several carriers for immobilization of recombinant Rhizobium etli CFN42 xylitol dehydrogenase (ReXDH) and subjected to characterization. Among four different chemical modification methods to give different functional groups, the silica nanoparticle derivatized with epoxy groups showed the highest immobilization efficiency (92%). The thermostability of ReXDH was improved more than tenfold by immobilization on epoxy-silica nanoparticles; the t(1/2) of the ReXDH was enhanced from 120 min to 1,410 min at 40 °C and from 30 min to 450 min at 50 °C. The K(m) of ReXDH was slightly altered from 17.9 to only 19.2 mM by immobilization. The immobilized ReXDH had significant reusability, as it retained 81% activity after eight cycles of batch conversion of xylitol into L-xylulose. A?71% conversion and a productivity of 10.7 g?h(-1)l(-1) were achieved when the immobilized ReXDH was employed to catalyze the biotransformation of xylitol to L-xylulose, a sugar that has been used in medicine and in the diagnosis of hepatitis. These results suggest that immobilization of ReXDH onto epoxy-silica nanoparticles has potential industrial application in rare sugar production. PMID:21246353

  9. Expression of thiamin biosynthetic genes (thiCOGE) and production of symbiotic terminal oxidase cbb3 in Rhizobium etli.

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    Miranda-ri?os, J.; Morera, C.; Taboada, H.; Da?valos, A.; Encarnacio?n, S.; Mora, J.; Sobero?n, M.

    1997-01-01

    In this paper we report the cloning and sequence analysis of four genes, located on plasmid pb, which are involved in the synthesis of thiamin in Rhizobium etli (thiC, thiO, thiG, and thiE). Two precursors, 4-methyl-5-(beta-hydroxyethyl)thiazole monophosphate and 4-amino-5-hydroxymethylpyrimidine pyrophosphate, are coupled to form thiamin monophosphate, which is then phosphorylated to make thiamin pyrophosphate. The first open reading frame (ORF) product, of 610 residues, has significant homo...

  10. Lipopolysaccharides of Rhizobium etli Strain G12 Act in Potato Roots as an Inducing Agent of Systemic Resistance to Infection by the Cyst Nematode Globodera pallida

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    Reitz, M.; Rudolph, K.; Schro?der, I.; Hoffmann-hergarten, S.; Hallmann, J.; Sikora, R. A.

    2000-01-01

    Recent studies have shown that living and heat-killed cells of the rhizobacterium Rhizobium etli strain G12 induce in potato roots systemic resistance to infection by the potato cyst nematode Globodera pallida. To better understand the mechanisms of induced resistance, we focused on identifying the inducing agent. Since heat-stable bacterial surface carbohydrates such as exopolysaccharides (EPS) and lipopolysaccharides (LPS) are essential for recognition in the symbiotic interaction between R...

  11. The extent of migration of the Holliday junction is a crucial factor for gene conversion in Rhizobium etli.

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    Castellanos, Mildred; Romero, David

    2009-08-01

    Gene conversion, defined as the nonreciprocal transfer of DNA, is one result of homologous recombination. Three steps in recombination could give rise to gene conversion: (i) DNA synthesis for repair of the degraded segment, (ii) Holliday junction migration, leading to heteroduplex formation, and (iii) repair of mismatches in the heteroduplex. There are at least three proteins (RuvAB, RecG, and RadA) that participate in the second step. Their roles have been studied for homologous recombination, but evidence of their relative role in gene conversion is lacking. In this work, we showed the effect on gene conversion of mutations in ruvB, recG, and radA in Rhizobium etli, either alone or in combination, using a cointegration strategy previously developed in our laboratory. The results indicate that the RuvAB system is highly efficient for gene conversion, since its absence provokes smaller gene conversion segments than those in the wild type as well as a shift in the preferred position of conversion tracts. The RecG system possesses a dual role for gene conversion. Inactivation of recG leads to longer gene conversion tracts than those in the wild type, indicating that its activity may hinder heteroduplex extension. However, under circumstances where it is the only migration activity present (as in the ruvB radA double mutant), conversion segments can still be seen, indicating that RecG can also promote gene conversion. RadA is the least efficient system in R. etli but is still needed for the production of detectable gene conversion tracts. PMID:19502410

  12. Canonical and non-canonical EcfG sigma factors control the general stress response in Rhizobium etli.

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    Jans, Ann; Vercruysse, Maarten; Gao, Shanjun; Engelen, Kristof; Lambrichts, Ivo; Fauvart, Maarten; Michiels, Jan

    2013-12-01

    A core component of the ?-proteobacterial general stress response (GSR) is the extracytoplasmic function (ECF) sigma factor EcfG, exclusively present in this taxonomic class. Half of the completed ?-proteobacterial genome sequences contain two or more copies of genes encoding ?(EcfG) -like sigma factors, with the primary copy typically located adjacent to genes coding for a cognate anti-sigma factor (NepR) and two-component response regulator (PhyR). So far, the widespread occurrence of additional, non-canonical ?(EcfG) copies has not satisfactorily been explained. This study explores the hierarchical relation between Rhizobium etli ?(EcfG1) and ?(EcfG2) , canonical and non-canonical ?(EcfG) proteins, respectively. Contrary to reports in other species, we find that ?(EcfG1) and ?(EcfG2) act in parallel, as nodes of a complex regulatory network, rather than in series, as elements of a linear regulatory cascade. We demonstrate that both sigma factors control unique yet also shared target genes, corroborating phenotypic evidence. ?(EcfG1) drives expression of rpoH2, explaining the increased heat sensitivity of an ecfG1 mutant, while katG is under control of ?(EcfG2) , accounting for reduced oxidative stress resistance of an ecfG2 mutant. We also identify non-coding RNA genes as novel ?(EcfG) targets. We propose a modified model for GSR regulation in R. etli, in which ?(EcfG1) and ?(EcfG2) function largely independently. Based on a phylogenetic analysis and considering the prevalence of ?-proteobacterial genomes with multiple ?(EcfG) copies, this model may also be applicable to numerous other species. PMID:24311555

  13. The Stringent Response Is Required for Amino Acid and Nitrate Utilization, Nod Factor Regulation, Nodulation, and Nitrogen Fixation in Rhizobium etli

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    Caldero?n-flores, Arturo; Du Pont, Gisela; Huerta-saquero, Alejandro; Merchant-larios, Horacio; Servi?n-gonza?lez, Luis; Dura?n, Socorro

    2005-01-01

    A Rhizobium etli Tn5 insertion mutant, LM01, was selected for its inability to use glutamine as the sole carbon and nitrogen source. The Tn5 insertion in LM01 was localized to the rsh gene, which encodes a member of the RelA/SpoT family of proteins. The LM01 mutant was affected in the ability to use amino acids and nitrate as nitrogen sources and was unable to accumulate (p)ppGpp when grown under carbon and nitrogen starvation, as opposed to the wild-type strain, which accumulated (p)ppGpp un...

  14. The stringent response is required for amino acid and nitrate utilization, nod factor regulation, nodulation, and nitrogen fixation in Rhizobium etli.

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    Calderón-Flores, Arturo; Du Pont, Gisela; Huerta-Saquero, Alejandro; Merchant-Larios, Horacio; Servín-González, Luis; Durán, Socorro

    2005-08-01

    A Rhizobium etli Tn5 insertion mutant, LM01, was selected for its inability to use glutamine as the sole carbon and nitrogen source. The Tn5 insertion in LM01 was localized to the rsh gene, which encodes a member of the RelA/SpoT family of proteins. The LM01 mutant was affected in the ability to use amino acids and nitrate as nitrogen sources and was unable to accumulate (p)ppGpp when grown under carbon and nitrogen starvation, as opposed to the wild-type strain, which accumulated (p)ppGpp under these conditions. The R. etli rsh gene was found to restore (p)ppGpp accumulation to a DeltarelA DeltaspoT mutant of Escherichia coli. The R. etli Rsh protein consists of 744 amino acids, and the Tn5 insertion in LM01 results in the synthesis of a truncated protein of 329 amino acids; complementation experiments indicate that this truncated protein is still capable of (p)ppGpp hydrolysis. A second rsh mutant of R. etli, strain AC1, was constructed by inserting an Omega element at the beginning of the rsh gene, resulting in a null allele. Both AC1 and LM01 were affected in Nod factor production, which was constitutive in both strains, and in nodulation; nodules produced by the rsh mutants in Phaseolus vulgaris were smaller than those produced by the wild-type strain and did not fix nitrogen. In addition, electron microscopy revealed that the mutant bacteroids lacked poly-beta-hydroxybutyrate granules. These results indicate a central role for the stringent response in symbiosis. PMID:16030199

  15. Effets de la double symbiose Rhizobium TAL 1147-Glomus clarum sur la croissance et la nodulation de Racosperma auriculiforme en République Démocratique du Congo

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    Bulakali, B.

    1999-01-01

    Full Text Available Effects of Inoculation with Rhizobium TAL 1147'-Glomus Clarum in a Nursery on Racosperma Auriculiforme Growth and Nodulation in Democratie Republic of Congo. The efficiency evaluation of five vesicular-arbuscular mycorrhiza spp. revealed that the mycobiont Glomus clarum is suitable for the mycorrhizogene replanting of the Kinzono grassy savanna. This present study reports results of effects of its inoculation at the same time that the Rhizobium TAL 1147 in nursery on Racosperma auriculiforme growth and nodulation in this same savanna's soil. Compared to the individual inoculation (Glomus clarum or Rhizobium TAL 1147 and to the uninoculated control, the dual inoculation Rhizobium TAL 1147-Glomus clarum has improved significantly (P <0.01 the growth and the nodulation of this legume tree five months after the sowing. A such inoculation can be recommended for an effective implantation at large-scale of this specie in poor Kinzono soil in nitrogen and in soluble phosphore.

  16. Effets de la double symbiose Rhizobium TAL 1147-Glomus clarum sur la croissance et la nodulation de Racosperma auriculiforme en République Démocratique du Congo

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    Bulakali, B.; Lumande, K.; Mbaya, N.; Luyindula, N.; Mwange, K.

    1999-01-01

    Effects of Inoculation with Rhizobium TAL 1147'-Glomus Clarum in a Nursery on Racosperma Auriculiforme Growth and Nodulation in Democratie Republic of Congo. The efficiency evaluation of five vesicular-arbuscular mycorrhiza spp. revealed that the mycobiont Glomus clarum is suitable for the mycorrhizogene replanting of the Kinzono grassy savanna. This present study reports results of effects of its inoculation at the same time that the Rhizobium TAL 1147 in nursery on Racosperma auriculiforme ...

  17. Characterization of IntA, a bidirectional site-specific recombinase required for conjugative transfer of the symbiotic plasmid of Rhizobium etli CFN42.

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    Hernández-Tamayo, Rogelio; Sohlenkamp, Christian; Puente, José Luis; Brom, Susana; Romero, David

    2013-10-01

    Site-specific recombination occurs at short specific sequences, mediated by the cognate recombinases. IntA is a recombinase from Rhizobium etli CFN42 and belongs to the tyrosine recombinase family. It allows cointegration of plasmid p42a and the symbiotic plasmid via site-specific recombination between attachment regions (attA and attD) located in each replicon. Cointegration is needed for conjugative transfer of the symbiotic plasmid. To characterize this system, two plasmids harboring the corresponding attachment sites and intA were constructed. Introduction of these plasmids into R. etli revealed IntA-dependent recombination events occurring at high frequency. Interestingly, IntA promotes not only integration, but also excision events, albeit at a lower frequency. Thus, R. etli IntA appears to be a bidirectional recombinase. IntA was purified and used to set up electrophoretic mobility shift assays with linear fragments containing attA and attD. IntA-dependent retarded complexes were observed only with fragments containing either attA or attD. Specific retarded complexes, as well as normal in vivo recombination abilities, were seen even in derivatives harboring only a minimal attachment region (comprising the 5-bp central region flanked by 9- to 11-bp inverted repeats). DNase I-footprinting assays with IntA revealed specific protection of these zones. Mutations that disrupt the integrity of the 9- to 11-bp inverted repeats abolish both specific binding and recombination ability, while mutations in the 5-bp central region severely reduce both binding and recombination. These results show that IntA is a bidirectional recombinase that binds to att regions without requiring neighboring sequences as enhancers of recombination. PMID:23935046

  18. Biochemical characterization of recombinant L-asparaginase (AnsA) from Rhizobium etli, a member of an increasing rhizobial-type family of L-asparaginases.

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    Moreno-Enriquez, Angelica; Evangelista-Martinez, Zahaed; Gonzalez-Mondragon, Edith G; Calderon-Flores, Arturo; Arreguin, Roberto; Perez-Rueda, Ernesto; Huerta-Saquero, Alejandro

    2012-03-01

    We report the expression, purification, and characterization of L-asparaginase (AnsA) from Rhizobium etli. The enzyme was purified to homogeneity in a single-step procedure involving affinity chromatography, and the kinetic parameters K(m), V(max), and k(cat) for L-asparagine were determined. The enzymatic activity in the presence of a number of substrates and metal ions was investigated. The molecular mass of the enzyme was 47 kDa by SDS-PAGE. The enzyme showed a maximal activity at 50 degrees C, but the optimal temperature of activity was 37 degrees C. It also showed maximal and optimal activities at pH 9.0. The values of K(m), V(max), k(cat), and k(cat)/K(m) were 8.9 +/- 0.967 × 10?³ M, 128 +/- 2.8 U/mg protein, 106 +/- 2 s?¹, and 1.2 +/- 0.105 × 10? M?¹s?¹, respectively. The L-asparaginase activity was reduced in the presence of Mn²?, Zn²?, Ca²?, and Mg²? metal ions for about 52% to 31%. In addition, we found that NH??, L-Asp, D-Asn, and beta-aspartyl-hydroxamate in the reaction buffer reduced the activity of the enzyme, whereas L-Gln did not modify its enzymatic activity. This is the first report on the expression and characterization of the L-asparaginase (AnsA) from R. etli. Phylogenetic analysis of asparaginases reveals an increasing group of known sequences of the Rhizobialtype asparaginase II family. PMID:22450783

  19. The Micro-RNA72c-APETALA2-1 Node as a Key Regulator of the Common Bean-Rhizobium etli Nitrogen Fixation Symbiosis.

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    Nova-Franco, Bárbara; Íñiguez, Luis P; Valdés-López, Oswaldo; Alvarado-Affantranger, Xochitl; Leija, Alfonso; Fuentes, Sara I; Ramírez, Mario; Paul, Sujay; Reyes, José L; Girard, Lourdes; Hernández, Georgina

    2015-05-01

    Micro-RNAs are recognized as important posttranscriptional regulators in plants. The relevance of micro-RNAs as regulators of the legume-rhizobia nitrogen-fixing symbiosis is emerging. The objective of this work was to functionally characterize the role of micro-RNA172 (miR172) and its conserved target APETALA2 (AP2) transcription factor in the common bean (Phaseolus vulgaris)-Rhizobium etli symbiosis. Our expression analysis revealed that mature miR172c increased upon rhizobial infection and continued increasing during nodule development, reaching its maximum in mature nodules and decaying in senescent nodules. The expression of AP2-1 target showed a negative correlation with miR172c expression. A drastic decrease in miR172c and high AP2-1 mRNA levels were observed in ineffective nodules. Phenotypic analysis of composite bean plants with transgenic roots overexpressing miR172c or a mutated AP2-1 insensitive to miR172c cleavage demonstrated the pivotal regulatory role of the miR172 node in the common bean-rhizobia symbiosis. Increased miR172 resulted in improved root growth, increased rhizobial infection, increased expression of early nodulation and autoregulation of nodulation genes, and improved nodulation and nitrogen fixation. In addition, these plants showed decreased sensitivity to nitrate inhibition of nodulation. Through transcriptome analysis, we identified 114 common bean genes that coexpressed with AP2-1 and proposed these as being targets for transcriptional activation by AP2-1. Several of these genes are related to nodule senescence, and we propose that they have to be silenced, through miR172c-induced AP2-1 cleavage, in active mature nodules. Our work sets the basis for exploring the miR172-mediated improvement of symbiotic nitrogen fixation in common bean, the most important grain legume for human consumption. PMID:25739700

  20. Transfer of the symbiotic plasmid of Rhizobium etli CFN42 requires cointegration with p42a, which may be mediated by site-specific recombination.

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    Brom, Susana; Girard, Lourdes; Tun-Garrido, Cristina; García-de los Santos, Alejandro; Bustos, Patricia; González, Víctor; Romero, David

    2004-11-01

    Plasmid p42a from Rhizobium etli CFN42 is self-transmissible and indispensable for conjugative transfer of the symbiotic plasmid (pSym). Most pSym transconjugants also inherit p42a. pSym transconjugants that lack p42a always contain recombinant pSyms, which we designated RpSyms*. RpSyms* do not contain some pSym segments and instead have p42a sequences, including the replication and transfer regions. These novel recombinant plasmids are compatible with wild-type pSym, incompatible with p42a, and self-transmissible. The symbiotic features of derivatives simultaneously containing a wild-type pSym and an RpSym* were analyzed. Structural analysis of 10 RpSyms* showed that 7 shared one of the two pSym-p42a junctions. Sequencing of this common junction revealed a 53-bp region that was 90% identical in pSym and p42a, including a 5-bp central region flanked by 9- to 11-bp inverted repeats reminiscent of bacterial and phage attachment sites. A gene encoding an integrase-like protein (intA) was localized downstream of the attachment site on p42a. Mutation or the absence of intA abolished pSym transfer from a recA mutant donor. Complementation with the wild-type intA gene restored transfer of pSym. We propose that pSym-p42a cointegration is required for pSym transfer; cointegration may be achieved either through homologous recombination among large reiterated sequences or through IntA-mediated site-specific recombination between the attachment sites. Cointegrates formed through the site-specific system but resolved through RecA-dependent recombination or vice versa generate RpSyms*. A site-specific recombination system for plasmid cointegration is a novel feature of these large plasmids and implies that there is unique regulation which affects the distribution of pSym in nature due to the role of the cointegrate in conjugative transfer. PMID:15516565

  1. A C subunit of the plant nuclear factor NF-Y required for rhizobial infection and nodule development affects partner selection in the common bean-Rhizobium etli symbiosis.

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    Zanetti, María Eugenia; Blanco, Flavio A; Beker, María Pía; Battaglia, Marina; Aguilar, O Mario

    2010-12-01

    Legume plants are able to interact symbiotically with soil bacteria to form nitrogen-fixing root nodules. Although specific recognition between rhizobia and legume species has been extensively characterized, plant molecular determinants that govern the preferential colonization by different strains within a single rhizobium species have received little attention. We found that the C subunit of the heterotrimeric nuclear factor NF-Y from common bean (Phaseolus vulgaris) NF-YC1 plays a key role in the improved nodulation seen by more efficient strains of rhizobia. Reduction of NF-YC1 transcript levels by RNA interference (RNAi) in Agrobacterium rhizogenes-induced hairy roots leads to the arrest of nodule development and defects in the infection process with either high or low efficiency strains. Induction of three G2/M transition cell cycle genes in response to rhizobia was impaired or attenuated in NF-YC1 RNAi roots, suggesting that this transcription factor might promote nodule development by activating cortical cell divisions. Furthermore, overexpression of this gene has a positive impact on nodulation efficiency and selection of Rhizobium etli strains that are naturally less efficient and bad competitors. Our findings suggest that this transcription factor might be part of a mechanism that links nodule organogenesis with an early molecular dialogue that selectively discriminates between high- and low-quality symbiotic partners, which holds important implications for optimizing legume performance. PMID:21139064

  2. Rhizobial 16S rRNA and dnaK Genes: Mosaicism and the Uncertain Phylogenetic Placement of Rhizobium galegae

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    Eardly, B. D.; Nour, S. M.; Berkum, P.; Selander, R. K.

    2005-01-01

    The phylogenetic relatedness among 12 agriculturally important species in the order Rhizobiales was estimated by comparative 16S rRNA and dnaK sequence analyses. Two groups of related species were identified by neighbor-joining and maximum-parsimony analysis. One group consisted of Mesorhizobium loti and Mesorhizobium ciceri, and the other group consisted of Agrobacterium rhizogenes, Rhizobium tropici, Rhizobium etli, and Rhizobium leguminosarum. Although bootstrap support for the placement o...

  3. Multiplication and Viability of some Rhizobium Strains to be used as Inoculants for Agricultural Biomass Production

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    Simina Neo

    2012-05-01

    Full Text Available Rhizobia are well known for their capacity to establish a symbiosis with legumes. They inhabit root nodules, where they reduce atmospheric nitrogen and make it available to the plant. Biological nitrogen fixation is an important component of sustainable agriculture, and rhizobial inoculants have been applied frequently as biofertilizers. In this review we approach the subject of legumes inoculation in order to improve the nitrogen fixing capacity. In the first part of the experiment, the Rhizobium strains were cultivated on media indicated in the literature as optimal for bacterial growing and development in laboratory conditions. Afterwards, the Rhizobium strains that have grown and accumulate biomass were tested in different conditions of pH and salinity. The biomass accumulation was determinate by spectrophotometer. The obtained values shown that the Rhizobium strains tested can be used to inoculate the legumes cultivated on acid, basic and alkaline soils. Finally, the stability in real time of two strains of Rhizobium (Rhizobium meliloti and Rhizobium japonicum mixed with different supports was evaluated during a 6- months period. The supports studied were: peat, peat and calcium carbonate, zeolite, and ceramic. The highest number of viable cells at the end of the experiment was obtained in ceramic with Rhizobium japonicum (8x105 cells/gram, and the lowest number of viable cells was obtained in zeolite with Rhizobium meliloti (1,1x103 cells/gram.

  4. Oligo- and polysaccharide synthesis by Rhizobium leguminosarum and Rhizobium meliloti.

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    Breedveld, M. W.

    1992-01-01

    Rhizobium and Agrobacterium species are capable of synthesizing a variety of extracellular and cellular oligo- and polysaccharides. Changes in environmental conditions may all affect the composition, physical properties, and relative amounts of oligo- and polysaccharides. Interest in the field of Rhizobium polys accharides has resulted from a development in two distinct areas, (i) the role of oligo- and polysaccharides in the microbe- plant interaction, and (ii) studies on the physico- chemic...

  5. Genome-wide detection of predicted non-coding RNAs in Rhizobium etli expressed during free-living and host-associated growth using a high-resolution tiling array

    Directory of Open Access Journals (Sweden)

    Thijs Inge M

    2010-01-01

    Full Text Available Abstract Background Non-coding RNAs (ncRNAs play a crucial role in the intricate regulation of bacterial gene expression, allowing bacteria to quickly adapt to changing environments. In the past few years, a growing number of regulatory RNA elements have been predicted by computational methods, mostly in well-studied ?-proteobacteria but lately in several ?-proteobacteria as well. Here, we have compared an extensive compilation of these non-coding RNA predictions to intergenic expression data of a whole-genome high-resolution tiling array in the soil-dwelling ?-proteobacterium Rhizobium etli. Results Expression of 89 candidate ncRNAs was detected, both on the chromosome and on the six megaplasmids encompassing the R. etli genome. Of these, 11 correspond to functionally well characterized ncRNAs, 12 were previously identified in other ?-proteobacteria but are as yet uncharacterized and 66 were computationally predicted earlier but had not been experimentally identified and were therefore classified as novel ncRNAs. The latter comprise 17 putative sRNAs and 49 putative cis-regulatory ncRNAs. A selection of these candidate ncRNAs was validated by RT-qPCR, Northern blotting and 5' RACE, confirming the existence of 4 ncRNAs. Interestingly, individual transcript levels of numerous ncRNAs varied during free-living growth and during interaction with the eukaryotic host plant, pointing to possible ncRNA-dependent regulation of these specialized processes. Conclusions Our data support the practical value of previous ncRNA prediction algorithms and significantly expand the list of candidate ncRNAs encoded in the intergenic regions of R. etli and, by extension, of ?-proteobacteria. Moreover, we show high-resolution tiling arrays to be suitable tools for studying intergenic ncRNA transcription profiles across the genome. The differential expression levels of some of these ncRNAs may indicate a role in adaptation to changing environmental conditions.

  6. Denitrification by Rhizobium meliloti

    Energy Technology Data Exchange (ETDEWEB)

    Rosen, A.

    1996-10-01

    Rhizobium meliloti strains were investigated for their denitrification activity as free-living cells and in nodules on lucerne (Medicago sativa) roots. They were also investigated for presence of nitrous oxide reductase (nos) activity and for genes using a nosZ probe derived from the Pseudomonas stutzeri. To decide whether R. meliloti strains used as inoculants contribute to the total denitrification activity in a lucerne ley, strains with different denitrifying capacities were used in field and laboratory experiments. The nitrate reduction activity of R. meliloti during anaerobic respiration was compared with that of a strain of Pseudomonas aeruginosa. A great diversity in the denitrification activity was found within strains of R. meliloti, and four of thirteen investigated strains showed an obvious denitrification activity. Two denitrifying bacteria were used as references, one strain each of Bradyrhizobium japonicum and P. aeruginosa. All but one of the R. meliloti strains hybridized to the PstI-fragment of the nosZ-gene from P. stutzeri. Two sizes of the hybridizing fragment, 5 and 7 kb, were noticed. Nos activity was only shown in three R. meliloti strains, and these were all characterized by a high denitrification activity. The potential denitrification activity was about 20, 40, and 80 times higher than the actual denitrification activity for lucerne, fallow, and grass, respectively. The potential denitrification activity was almost the same in lucerne and grass planted soils. Compared with the unplanted soil, the presence of lucerne roots in the soil increased the actual denitrification activity, while roots of both plant species, grass and lucerne, increased the potential denitrification activity in the soil. 32 refs, 7 figs, 1 tab

  7. Melanin Production by Rhizobium Strains

    OpenAIRE

    Cubo, M. Teresa; Buendia-Claveria, Ana M.; Beringer, John E.; Ruiz-Sainz, José E.

    1988-01-01

    Different Rhizobium and Bradyrhizobium strains were screened for their ability to produce melanin. Pigment producers (Mel+) were found among strains of R. leguminosarum biovars viceae, trifolii, and phaseoli, R. meliloti, and R. fredii; none of 19 Bradyrhizobium strains examined gave a positive response. Melanin production and nod genes were plasmid borne in R. leguminosarum biovar trifolii RS24. In R. leguminosarum biovar phaseoli CFN42 and R. meliloti GR015, mel genes were located in the re...

  8. Polyol metabolism by Rhizobium trifolii.

    OpenAIRE

    Primrose, S.B.; Ronson, C W

    1980-01-01

    In Rhizobium trifolii 7000, the polyols myo-inositol, xylitol, ribitol, D-arabitol, D-mannitol, D-sorbital, and dulcitol are metabolized by inducible nicotinamide adenine dinucleotide-dependent polyol dehydrogenases. Five different polyol dehydrogenases were recognized: inositol dehydrogenase, specific for inositil; ribitol dehydrogenase, specific for ribitol; D-arabitol dehydrogenase, which oxidized D-arabitol, D-mannitol, and D-sorbitol; xylitol dehydrogenase, which oxidized xylitol and D-s...

  9. Genome Sequence of Rhizobium sp. Strain CCGE510, a Symbiont Isolated from Nodules of the Endangered Wild Bean Phaseolus albescens

    OpenAIRE

    Servín-Garcidueñas, Luis E.; Rogel, Marco A; Ormeño-Orrillo, Ernesto; Delgado-Salinas, Alfonso; Martínez-Romero, Julio; Sánchez, Federico; Martínez-Romero, Esperanza

    2012-01-01

    We present the genome sequence of Rhizobium sp. strain CCGE510, a nitrogen fixing bacterium taxonomically affiliated with the R. leguminosarum-R. etli group, isolated from wild Phaseolus albescens nodules grown in native pine forests in western Mexico. P. albescens is an endangered bean species phylogenetically related to P. vulgaris. In spite of the close host relatedness, Rhizobium sp. CCGE510 does not establish an efficient symbiosis with P. vulgaris. This is the first genome of a Rhizobiu...

  10. An Outer Membrane Enzyme That Generates the 2-Amino-2-deoxy-gluconate Moiety of Rhizobium leguminosarum Lipid A*S

    OpenAIRE

    Que-gewirth, Nanette L. S.; Lin, Shanhua; Cotter, Robert J.; Raetz, Christian R. H.

    2003-01-01

    The structures of Rhizobium leguminosarum and Rhizobium etli lipid A are distinct from those found in other Gram-negative bacteria. Whereas the more typical Escherichia coli lipid A is a hexa-acylated disaccharide of glucosamine that is phosphorylated at positions 1 and 4?, R. etli and R. leguminosarum lipid A consists of a mixture of structurally related species (designated A–E) that lack phosphate. A conserved distal unit, comprised of a diacylated glucosamine moiety with galacturonic a...

  11. Rhizobium metallidurans sp. nov., a symbiotic heavy metal resistant bacterium isolated from the Anthyllis vulneraria Zn-hyperaccumulator.

    Science.gov (United States)

    Grison, Claire M; Jackson, Stephen; Merlot, Sylvain; Dobson, Alan; Grison, Claude

    2015-05-01

    A Gram-stain-negative, aerobic, rod-shaped, non-spore-forming bacterium (ChimEc512(T)) was isolated from 56 host seedlings of the hyperaccumulating Anthyllis vulneraria legume, which was on an old zinc mining site at Les Avinières, Saint-Laurent-Le-Minier, Gard, South of France. On the basis of 16S rRNA gene sequence similarities, strain ChimEc512(T) was shown to belong to the genus Rhizobium and to be most closely related to Rhizobium endophyticum CCGE 2052(T) (98.4?%), Rhizobium tibeticum CCBAU 85039(T) (98.1?%), Rhizobium grahamii CCGE 502(T) (98.0?%) and Rhizobium mesoamericanum CCGE 501(T) (98.0?%). The phylogenetic relationships of ChimEc512(T) were confirmed by sequencing and analyses of recA and atpD genes. DNA-DNA relatedness values of strain ChimEc512(T) with R. endophyticum CCGE 2052(T), R. tibeticum CCBAU 85039(T), R. mesoamericanum CCGE 52(T), Rhizobium grahamii CCGE 502(T), Rhizobium etli CCBAU 85039(T) and Rhizobium radiobacter KL09-16-8-2(T) were 27, 22, 16, 18, 19 and 11?%, respectively. The DNA G+C content of strain ChimEc512(T) was 58.9 mol%. The major cellular fatty acid was C18?:?1?7c, characteristic of the genus Rhizobium . The polar lipid profile included phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol and phosphatidylcholine and moderate amounts of aminolipids, phospholipid and sulfoquinovosyl diacylglycerol. Although ChimEc512(T) was able to nodulate A. vulneraria, the nodC and nifH genes were not detected by PCR. The rhizobial strain was tolerant to high concentrations of heavy metals: up to 35 mM Zn and up to 0.5 mM Cd and its growth kinetics was not impacted by Zn. The results of DNA-DNA hybridizations and physiological tests allowed genotypic and phenotypic differentiation of strain ChimEc512(T) from species of the genus Rhizobium with validly published names. Strain ChimEc512(T), therefore, represents a novel species, for which the name Rhizobium metallidurans sp. nov. is proposed, with the type strain ChimEc512(T) (?=?DSM 26575?=?CIP 110550(T)). PMID:25701848

  12. Reclassification of Rhizobium tropici type A strains as Rhizobium leucaenae sp. nov.

    Science.gov (United States)

    Ribeiro, Renan Augusto; Rogel, Marco A; López-López, Aline; Ormeño-Orrillo, Ernesto; Barcellos, Fernando Gomes; Martínez, Julio; Thompson, Fabiano Lopes; Martínez-Romero, Esperanza; Hungria, Mariangela

    2012-05-01

    Rhizobium tropici is a well-studied legume symbiont characterized by high genetic stability of the symbiotic plasmid and tolerance to tropical environmental stresses such as high temperature and low soil pH. However, high phenetic and genetic variabilities among R. tropici strains have been largely reported, with two subgroups, designated type A and B, already defined within the species. A polyphasic study comprising multilocus sequence analysis, phenotypic and genotypic characterizations, including DNA-DNA hybridization, strongly supported the reclassification of R. tropici type A strains as a novel species. Type A strains formed a well-differentiated clade that grouped with R. tropici, Rhizobium multihospitium, Rhizobium miluonense, Rhizobium lusitanum and Rhizobium rhizogenes in the phylogenies of the 16S rRNA, recA, gltA, rpoA, glnII and rpoB genes. Several phenotypic traits differentiated type A strains from all related taxa. The novel species, for which the name Rhizobium leucaenae sp. nov. is proposed, is a broad host range rhizobium being able to establish effective root-nodule symbioses with Leucaena leucocephala, Leucaena esculenta, common beans (Phaseolus vulgaris) and Gliricidia sepium. Strain CFN 299(T) (?=?USDA 9039(T)?=?LMG 9517(T)?=?CECT 4844(T)?=?JCM 21088(T)?=?IAM 14230(T)?=?SEMIA 4083(T)?=?CENA 183(T)?=?UMR1026(T)?=?CNPSo 141(T)) is designated the type strain of Rhizobium leucaenae sp. nov. PMID:21742822

  13. Genes Essential for Nod Factor Production and Nodulation Are Located on a Symbiotic Amplicon (AMPRtrCFN299pc60) in Rhizobium tropici

    OpenAIRE

    Mavingui, Patrick; Laeremans, Toon; Flores, Margarita; Romero, David; Marti?nez-romero, Esperanza; Palacios, Rafael

    1998-01-01

    Amplifiable DNA regions (amplicons) have been identified in the genome of Rhizobium etli. Here we report the isolation and molecular characterization of a symbiotic amplicon of Rhizobium tropici. To search for symbiotic amplicons, a cartridge containing a kanamycin resistance marker that responds to gene dosage and conditional origins of replication and transfer was inserted in the nodulation region of the symbiotic plasmid (pSym) of R. tropici CFN299. Derivatives harboring amplifications wer...

  14. Congo Red Absorption by Rhizobium leguminosarum

    OpenAIRE

    Kneen, Barbara E.; Larue, Thomas A.

    1983-01-01

    Congo red absorption is generally considered a contraindication of Rhizobium. However, R. leguminosarum takes up the dye on yeast extract-mannitol agar. The uptake of congo red varies among strains of R. leguminosarum, as shown elsewhere with strains of R. trifolii and R. meliloti. Congo red absorption does not distinguish rhizobia from other bacteria, but may be useful as a strain marker.

  15. : Les Struthionidae et les Pelagornithidae (Aves, Struthioniformes et Odontopterygiformes) du Pliocène final d'Ahl al Oughlam, Maroc

    OpenAIRE

    Mourer-Chauviré, Cécile; Geraads, Denis

    2005-01-01

    Le gisement pliocène d'Ahl al Oughlam est situé à la limite sud-est de la ville de Casablanca, au Maroc, sur un ancien rivage de l'Océan Atlantique. Il a livré une très riche faune de Vertébrés (macro- et micromammifères, oiseaux, reptiles, amphibiens et poissons), appartenant surtout à des formes terrestres, mais comportant aussi des formes marines. Des arguments biostratigraphiques ont permis de dater cette faune de 2,5 Ma, ce qui correspond au Pliocène final. L'avifaune est très diversifié...

  16. Nodulation of Acacia Species by Fast- and Slow-Growing Tropical Strains of Rhizobium

    OpenAIRE

    Dreyfus, B. L.; Dommergues, Y. R.

    1981-01-01

    Thirteen Acacia species were classified into three groups according to effective nodulation response patterns with fast- and slow-growing tropical strains of Rhizobium. The first group nodulated effectively with slow-growing, cowpea-type Rhizobium strains; the second, with fast-growing Rhizobium strains; and the third, with both fast- and slow-growing Rhizobium strains. The Rhizobium requirements of the Acacia species of the second group were similar to those of Leucaena leucocephala.

  17. En route vers la nano stabilisation de CLIC faisceau principale et focalisation finale

    CERN Document Server

    Artoos, K; Guinchard, M; Hauviller, Claude; Lackner, F; CERN. Geneva. TS Department

    2008-01-01

    Pour atteindre la luminosité voulue de CLIC, la taille transversale du faisceau doit être de l?ordre du nanomètre. Ceci nécessite une stabilité vibratoire des quadripôles du faisceau principal de 1 nm et même 0.1 nm pour les doublets de la focalisation finale. La nano technologie et la nano stabilisation sont des activités qui évoluent rapidement dans l?industrie et centres de recherche pour des applications très variées comme l?électronique, l?optique, la chimie voire la médecine. Cette présentation décrit les avancées techniques nécessaires pour atteindre l?objectif de CLIC et les projets et collaborations R&D prévus pour démontrer la faisabilité de la nano stabilisation de CLIC en 2010.

  18. Characterization of Rhizobium japonicum hydrogen uptake genes.

    OpenAIRE

    Haugland, R A; Cantrell, M A; Beaty, J S; Hanus, F J; Russell, S. A.; Evans, H.J.

    1984-01-01

    Recombinant cosmids from a gene library of the DNA from Hup+ Rhizobium japonicum 122DES previously have been shown to restore hydrogenase activity when transferred by conjugation into certain Hup- mutants of R. japonicum. We generated a restriction map covering 32.2 kilobases of this cosmid DNA. At least 25.3 kilobases of the cosmid pHU1 were shown to have the same arrangement as those in the genome of strain 122DES. Analysis of Tn5 insertions into the 122DES genome indicates that hup-specifi...

  19. An Experimental Test of the Rhizopine Concept in Rhizobium meliloti

    OpenAIRE

    Gordon, D. M.; Ryder, M. H.; Heinrich, K.; Murphy, P. J.

    1996-01-01

    In some Rhizobium-legume symbioses, compounds known as rhizopines are synthesized by bacteroids and subsequently catabolized by free-living cells of the producing strain. It has been suggested than rhizopines act as proprietary growth substrates and enhance the competitive ability of the producing strain in its interactions with the diverse microbial community found within the rhizosphere. Wild-type, rhizopine-producing Rhizobium meliloti L5-30 and mutant L5-30 strains deficient for either rh...

  20. Absorción de cobre y características de Leucaena leucocephala asociada con Glomus spp. y Rhizobium en suelo contaminado del Río Lerma, México

    Directory of Open Access Journals (Sweden)

    Abdul Khalil Gardezi

    2006-01-01

    Full Text Available El objetivo de esta investigación fue evaluar (a la capacidad de absorción de Cu por Leucaena leucocephala y (b el efecto en sus características agronómicas al inocularse con hongos endomicorrízicos arbusculares y Rhizobium como alternativa para la fitorremediación de suelos agrícolas contaminados. El trabajo se realizó en condiciones de invernadero en suelo contaminado por Cu procedente de la parte alta de la cuenca del río Lerma, estado de México. Las plantas de Leucaena crecieron en bolsas de polietileno negro con 3 kg del suelo contaminado esterilizado o no esterilizado. Se aplicaron 0, 20 y 200 mg de Cu kg-1 de suelo contaminado tratado con Glomus sp. Zac-19, Glomus intraradices o sin Glomus, e inoculado con Rhizobium o sin Rhizobium. Se evaluaron la acumulación de Cu en las plantas, sus características agronómicas y el contenido final de Cu en el suelo. La acumulación de Cu en las plantas fue mayor en tallos que en hojas y se asoció a la disminución de su concentración en el suelo a través del tiempo. No hubo efecto de la esterilización del suelo sobre la acumulación de Cu, ni sobre las características agronómicas de las plantas, excepto sobre el número de nódulos de Rhizobium. Se observó significativamente (P < 0.05 mayor acumulación de Cu al incrementarse su concentración en el suelo, destacando un efecto positivo de 20 mg de Cu kg-1 de suelo al mejorar las características agronómicas. Las plantas con mejores características agronómicas disminuyeron su tendencia a la absorción de Cu en presencia simultánea de Glomus spp. y Rhizobium. Esto demuestra un efecto interactivo positivo de la doble inoculación endomicorriza más Rhizobium en la absorción de Cu por las plantas de Leucaena y aumenta su papel en el diseño de estrategias de reforestación y fitorremediación de suelos agrícolas contaminados por cobre.

  1. The beneficial effect of dual inoculation of vesicular-arbuscular mycorrhizae + rhizobium on growth of white clover

    Directory of Open Access Journals (Sweden)

    Lin, XG.

    1993-01-01

    Full Text Available Investigation on the effect of phosphorus on vesicular-arbuscular mycorrhizal infection, and dual inoculation of vesicular-arbuscular mycorrhizae + rhizobium on growth of white clover under field microplots and pot experiments was conducted on fluvo-aquic soils of semi-arid region in north China. The results showed that 60 kg P205 ha in form of superphosphate was the most favorable phosphorus level for vesicular-arbuscular mycorrhizal infection ; mycorrhizal infection, nodulation, dry weight of shoots and roots, total uptake of nitrogen, phosphorus and other elements, the final yields and recovery of phosphorus of white clover were significantly increased by vesicular-arbuscular mycorrhizal inoculation and dual inoculation with vesicular-arbuscular mycorrhizal fungi and rhizobium. The highest response of inoculation was obtained by adding fertilizer phosphorus at the level of 60 kg P205 ha in form of superphosphate.

  2. Physiological role of calcium in legume-rhizobium symbiosis

    Directory of Open Access Journals (Sweden)

    Vasil’eva G.G.

    2011-12-01

    Full Text Available Literature data on the physiological role of calcium (Ca2+ in legume-rhizobium symbiosis development on initial stages - the infection and symbiotic structures formation, are generalized. The questions about the Ca2+ function in plants, special feature the formation of legume-rhizobium symbiosis and role of calcium in the interaction of two organisms are considered. Data on the interaction of ROS and Ca2+ in the development of the legume-rhizobium symbiosis and the relationship of NADPH-oxidase activity with the calcium signaling system are analyzed. The special attention is given to the role of Ca22+-spiking and calcium and calmodulin-like kinase in the initiation of plant symbiotic ways operation leads to infection and the formation of symbiotic structures.

  3. Danish Rhizobium leguminosarum strains nodulating ‘Afghanistan’ pea (Pisum sativum)

    DEFF Research Database (Denmark)

    Jensen, Erik Steen; SØrensen, Lasse Holst

    1986-01-01

    A wild pea (Pisum sativum L.) native to Afghanistan normally known to be resisant to nodulation with European strains of Rhizobium leguminosarum was nodulated early and effectively in field soil in Denmark. Isolates from nodules formed effective nodules abundantly on 'Afghanistan' on reinfection under aseptic conditions. Five types differing in isoenzyme composition pattern were found among 15 isolates from 'Afghanistan' nodules. None were identical with 'Tom' strain from Turkey, which also forms effective nodules with 'Afghanistan'. The five types were also different with respect to isoenzyme pattern with Rhizobium leguminosarum strains isolated from a modern pea variety cultivated in the same field.

  4. Portraits du dégénéré en fou, en primitif, en enfant et finalement en artiste.

    Directory of Open Access Journals (Sweden)

    Stéphane Legrand

    2004-04-01

    Full Text Available Cet article traite du concept de « dégénérescence », importé dans la psychiatrie française par Benedict-Auguste Morel dans les années 1850, et largement diffusé par la suite, dans ce champ ainsi que dans celui de la criminologie. On tente d’analyser la reconfiguration qu’impose ce concept au savoir psychiatrique en dégageant la manière dont il permet d’intégrer en un ensemble cohérent plusieurs modèles théoriques: un paradigme neurologique, une théorie de l’automatisme morbide, un certain évolutionnisme. Sur ces bases, on essaie d’établir les similitudes de fonds existant entre les conceptions psychiatrique et criminologique de la dégénérescence, en montrant qu’elles mobilisent le même réseau « structurant » d’analogies entre les figures de l’anormal (le fou, le sauvage, l’enfant, la femme, l’animal; et l’on s’efforce de montrer que ces théories promeuvent une logique dans laquelle les infractions aux différents types de normes (biologiques, sociales, morales, juridiques, psychologiques, économiques sont susceptibles de faire systématiquement référence les unes aux autres, de se traduire les unes dans les autres. Puis l’on caractérise les transformations que ce nouveau paradigme impose aux principes de la thérapeutique, de la pédagogie et de la prise en charge des malades mentaux et des déviants. Pour finir, on présente les éléments latents qui dans ce paradigme préparent et indiquent déjà sa remise en cause et son renversement à venir.This article deals with the concept of «degeneration», introduced by Benedict-Auguste Morel in the French psychiatry during the 1850s, and which widely spread afterwards, in this field as well as in the contemporary criminology. An analysis is tried of the changes imposed by this notion on the psychiatric knowledge, changes that resulted in the integration in a coherent system of three other paradigms: a neurological paradigm, a theory of pathological automatism, a certain kind of evolutionary theory. The author then tries to establish the existence of background similarities between the psychiatric and criminological theories of degeneration, namely in as much as they promote the same «structural» analogies between the various forms of abnormality (the madman, the primitive, the woman, the child, the animal; and it is shown that these theories also imply a logic in which all the transgressions of the different kinds of norms (biological, social, moral, juridical, psychological, economical tend to be systematically referred to one another, and translated into one another. Then a sketch is given of the changes imposed by this paradigm to the principles of therapy and pedagogy for the insane persons. And finally the author presents some of the themes that, in this paradigm, already prepare its deconstruction to come.

  5. Rhizobium sophorae sp. nov. and Rhizobium sophoriradicis sp. nov., nitrogen-fixing rhizobial symbionts of the medicinal legume Sophora flavescens.

    Science.gov (United States)

    Jiao, Yin Shan; Yan, Hui; Ji, Zhao Jun; Liu, Yuan Hui; Sui, Xin Hua; Wang, En Tao; Guo, Bao Lin; Chen, Wen Xin; Chen, Wen Feng

    2015-02-01

    Five bacterial strains representing 45 isolates originated from root nodules of the medicinal legume Sophora flavescens were defined as two novel groups in the genus Rhizobium based on their phylogenetic relationships estimated from 16S rRNA genes and the housekeeping genes recA, glnII and atpD. These groups were distantly related to Rhizobium leguminosarum USDA 2370(T) (95.6 % similarity for group I) and Rhizobium phaseoli ATCC 14482(T) (93.4 % similarity for group II) in multilocus sequence analysis. In DNA-DNA hybridization experiments, the reference strains CCBAU 03386(T) (group I) and CCBAU 03470(T) (group II) showed levels of relatedness of 17.9-57.8 and 11.0-42.9 %, respectively, with the type strains of related species. Both strains CCBAU 03386(T) and CCBAU 03470(T) contained ubiquinone 10 (Q-10) as the major respiratory quinone and possessed 16 : 0, 18 : 0, 19 : 0 cyclo ?8c, summed feature 8 and summed feature 2 as major fatty acids, but did not contain 20 : 3 ?6,8,12c. Phenotypic features distinguishing both groups from all closely related species of the genus Rhizobium were found. Therefore, two novel species, Rhizobium sophorae sp. nov. for group I (type strain CCBAU 03386(T)?= E5(T)?= LMG 27901(T)?= HAMBI 3615(T)) and Rhizobium sophoriradicis sp. nov. for group II (type strain CCBAU 03470(T)?= C-5-1(T)?= LMG 27898(T)?= HAMBI 3510(T)), are proposed. Both groups were able to nodulate Phaseolus vulgaris and their hosts of origin (Sophora flavescens) effectively and their nodulation gene nodC was phylogenetically located in the symbiovar phaseoli. PMID:25385989

  6. Quorum signal molecules as biosurfactants affecting swarming in Rhizobium etli

    OpenAIRE

    Daniels, Ruth; Reynaert, Sven; Hoekstra, Hans; Verreth, Christel; Janssens, Joost; Braeken, Kristien; Fauvart, Maarten; Beullens, Serge; Heusdens, Christophe; Lambrichts, Ivo; Vos, Dirk E.; Vanderleyden, Jos; Vermant, Jan; Michiels, Jan

    2006-01-01

    Swarming motility is suggested to be a social phenomenon that enables groups of bacteria to coordinately and rapidly move atop solid surfaces. This multicellular behavior, during which the apparently organized bacterial populations are embedded in an extracellular slime layer, has previously been linked with biofilm formation and virulence. Many population density-controlled activities involve the activation of complex signaling pathways using small diffusible molecules, also known as autoind...

  7. Draft Genome Sequence of Rhizobium rhizogenes Strain ATCC 15834.

    Science.gov (United States)

    Kajala, Kaisa; Coil, David A; Brady, Siobhan M

    2014-01-01

    Here, we present the draft genome of Rhizobium rhizogenes strain ATCC 15834. The genome contains 7,070,307 bp in 43 scaffolds. R. rhizogenes, also known as Agrobacterium rhizogenes, is a plant pathogen that causes hairy root disease. This hairy root induction has been used in biotechnology for the generation of transgenic root cultures. PMID:25359916

  8. Draft Genome Sequence of Rhizobium rhizogenes Strain ATCC 15834

    OpenAIRE

    Kajala, Kaisa; Coil, David A; Brady, Siobhan M.

    2014-01-01

    Here, we present the draft genome of Rhizobium rhizogenes strain ATCC 15834. The genome contains 7,070,307 bp in 43 scaffolds. R. rhizogenes, also known as Agrobacterium rhizogenes, is a plant pathogen that causes hairy root disease. This hairy root induction has been used in biotechnology for the generation of transgenic root cultures.

  9. Infection and nodulation of clover by nonmotile Rhizobium trifolii.

    OpenAIRE

    Napoli, C.; Albersheim, P.

    1980-01-01

    Nonmotile mutants of Rhizobium trifolii were isolated to determine whether bacterial motility is required for the infection and nodulation of clover. The nonmotile mutants were screened for their ability to infect and nodulate clover seedlings in Fahraeus glass slide assemblies, plastic growth pouches, and vermiculite-sand-filled clay pots. In each system, the nonmotile mutants were able to infect and nodulate clover.

  10. Rhizobium alvei sp. nov., isolated from a freshwater river.

    Science.gov (United States)

    Sheu, Shih-Yi; Huang, Hsing-Wei; Young, Chiu-Chung; Chen, Wen-Ming

    2015-02-01

    A bacterial strain designated TNR-22(T) was isolated from a freshwater river in Taiwan and characterized using a polyphasic taxonomic approach. Cells of strain TNR-22(T) were facultatively anaerobic, Gram-stain-negative, rod-shaped, motile by a single polar flagellum and formed cream-coloured colonies. Growth occurred at 4-45 °C (optimum, 25-30 °C), with 0-1.0 % (w/v) NaCl (optimum, 0.5 %) and at pH 7.0-8.0 (optimum, pH 7.0). Strain TNR-22(T) did not form nodules on Macroptilium atropurpureum. The nifH gene encoding denitrogenase reductase was not detected by PCR. The major fatty acids (>10 %) of strain TNR-22(T) were C18 : 1?7c and C16 : 0. The DNA G+C content was 60.3 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, an uncharacterized aminoglycolipid and an uncharacterized phospholipid. Comparative analysis of 16S rRNA gene sequences showed that strain TNR-22(T) constituted a distinct branch within the genus Rhizobium, showing the highest level of sequence similarity with Rhizobium rosettiformans W3(T) (96.3 %). Phenotypic characteristics of the novel strain also differed from those of the most closely related species of the genus Rhizobium. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain TNR-22(T) represents a novel species in the genus Rhizobium, for which the name Rhizobium alvei sp. nov. is proposed. The type strain is TNR-22(T) (?= BCRC 80408(T)?= LMG 26895(T)?= KCTC 23919(T)). PMID:25385988

  11. [A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis]. Progress report, June 1989--June 1991

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, R.I.

    1991-12-31

    Research continued on the study of cell surface carbohydrates of Rhizobium. Objectives include: To characterize, at a structural level, the differences between the lipopolysaccharides of a representative number of strains from different Rhizobium species to determine which features of LPS structure are species-specific and might, therefore, be determinants of host specificity. Determine the effect(s) of nod gene induction on the structure of Rhizobium lipopolysaccharides and determine whether synthesis of a modified LPS molecule or a new surface glycoconjugate is initiated by nod gene induction. Develop a non-chemical means for rapidly screening large numbers of bacterial strains in order to determine which glycoconjugate structural features are conserved between strains of the same species. Provide the necessary structural information which, when coupled with developments in the rapidly expanding field of Rhizobium genetics, should lead to a clear understanding of the role of Rhizobium surface glycoconjugates in host/symbiont interactions. Progress is discussed.

  12. Rhizobium Promotes Non-Legumes Growth and Quality in Several Production Steps: Towards a Biofertilization of Edible Raw Vegetables Healthy for Humans

    OpenAIRE

    Garci?a-fraile, Paula; Carro, Lorena; Robledo, Marta; Rami?rez-bahena, M. H.; Flores-fe?lix, Jose?-david; Fernández, María Teresa; Mateos, P. F.; Rivas, R.; Igual, Jose? Mariano; Marti?nez-molina, E.; Peix, A.; Vela?zquez, E.

    2012-01-01

    The biofertilization of crops with plant-growth-promoting microorganisms is currently considered as a healthy alternative to chemical fertilization. However, only microorganisms safe for humans can be used as biofertilizers, particularly in vegetables that are raw consumed, in order to avoid sanitary problems derived from the presence of pathogenic bacteria in the final products. In the present work we showed that Rhizobium strains colonize the roots of tomato and pepper plants promotin...

  13. The Effect of Rhizobium spp. Inoculation on Seed Quality of Bean in Turkey

    Directory of Open Access Journals (Sweden)

    Cigdem KuCuk

    2008-01-01

    Full Text Available Rhizobium spp. (local isolate was used to inoculate three bean (Phaseolus vulgaris L. varieties; Akman 98, Goynuk 98 and Sehirali 90, in a factorial field experiment. The objective of the experiment was to study effect of inoculation on seed yield, protein range, seed weight, non-soaker capacity and hydration index. Rhizobium spp. inoculation and nitrogen fertilizer significantly increased characters tested. This study revealed that inoculation with Rhizobium spp. improved seed quality.

  14. Genetic diversity of Rhizobium from nodulating beans grown in a variety of Mediterranean climate soils of Chile.

    Science.gov (United States)

    Baginsky, Cecilia; Brito, Belén; Scherson, Rosita; Pertuzé, Ricardo; Seguel, Oscar; Cañete, Alejandro; Araneda, Cristian; Johnson, Warren E

    2015-04-01

    In spite of potentially being an important source of rhizobial diversity and a key determinant of common bean productivity, there is a paucity of data on Rhizobium genetic variation and species composition in the important bean producing area of Chile and only one species has been documented (Rhizobium leguminosarum). In this study, 240 Rhizobium isolates from Torcaza bean (Phaseolus vulgaris L.) nodules established in the highest bean producing area in Chile (33°34'S-70°38'W and 37°36'S-71°47'W) were characterized by PCR-RFLP markers for nodC gene, revealing eight banding patterns with the polymorphic enzyme Hinf I. The locality of San Agustín de Aurora in Central Chile (35°32'S-71°29'W) had the highest level of diversity. Isolates were classified by species using PCR-RFLP markers for 16S rDNA gene and were confirmed by sequencing an internal fragment of the 16S rDNA gene. The results confirmed the presence of R. leguminosarum and three other species of rhizobia nodulating beans in South Central Chile (R. etli, R. tropici and R. leucaenae). R. tropici and R. leucaenae showed the least genetic variation and were most commonly identified in acid soils, while R. etli was the most common species in slightly acidic to moderately alkaline soils, with higher levels of organic matter content. R. leguminosarum was identified in almost all soils, was the most genetically diverse, and was the most common, being documented in soils with pH that ranged between 5.3 and 8.2, and with organic matter content between 2.1 and 4 %. PMID:25533847

  15. The conjugative plasmid of a bean-nodulating Sinorhizobium fredii strain is assembled from sequences of two Rhizobium plasmids and the chromosome of a Sinorhizobium strain

    OpenAIRE

    Brom Susana; Romero David; Vinuesa Pablo; Dávila Guillermo; Santamaría Rosa; Girard Lourdes; Bustos Patricia; Cervantes Laura

    2011-01-01

    Abstract Background Bean-nodulating Rhizobium etli originated in Mesoamerica, while soybean-nodulating Sinorhizobium fredii evolved in East Asia. S. fredii strains, such as GR64, have been isolated from bean nodules in Spain, suggesting the occurrence of conjugative transfer events between introduced and native strains. In R. etli CFN42, transfer of the symbiotic plasmid (pRet42d) requires cointegration with the endogenous self-transmissible plasmid pRet42a. Aiming at further understanding th...

  16. Recombinant Rhizobium meliloti strains with extra biotin synthesis capability.

    OpenAIRE

    Streit, W R; Phillips, D. A.

    1996-01-01

    The growth of Rhizobium meliloti 1021 in an experimental alfalfa (Medicago sativa L.) rhizosphere was stimulated by adding nanomolar amounts of biotin. To overcome this biotin limitation, R. meliloti strains were constructed by conjugating the Escherichia coli biotin synthesis operon into biotin auxotroph R. meliloti 1021-B3. Transconjugant strains Rm1021-WS10 and Rm1021-WS11 grew faster in vitro and achieved a higher cell density than did R. meliloti 1021 and overproduced biotin on a defined...

  17. Carbon Metabolism Enzymes of Rhizobium tropici Cultures and Bacteroids

    OpenAIRE

    Romanov, Vassily I.; Hernández-Lucas, Ismael; Martínez-Romero, Esperanza

    1994-01-01

    We determined the activities of selected enzymes involved in carbon metabolism in free-living cells of Rhizobium tropici CFN299 grown in minimal medium with different carbon sources and in bacteroids of the same strain. The set of enzymatic activities in sucrose-grown cells suggests that the pentose phosphate pathway, with the participation of the Entner-Doudoroff pathway, is probably the primary route for sugar catabolism. In glutamate- and malate-grown cells, high activities of the gluconeo...

  18. Isolation of competition-defective mutants of Rhizobium fredii.

    OpenAIRE

    Mcloughlin, T. J.; Merlo, A. O.; Satola, S. W.; Johansen, E.

    1987-01-01

    We coupled Tn5 mutagenesis with a competition assay to isolate mutants of Rhizobium fredii USDA 257 that are defective in competition for nodulation of soybeans. Two mutants with single Tn5 inserts in the chromosome showed reduced competitiveness in vermiculite but were identical to the wild-type strain in symbiotic properties when inoculated alone. Recombination of Tn5 and flanking genomic regions cloned from the mutants into the parent strain showed that Tn5 was responsible for the mutant p...

  19. Influence of Environmental Factors on Interstrain Competition in Rhizobium japonicum†

    OpenAIRE

    Kosslak, Renee M.; Bohlool, B. Ben

    1985-01-01

    The effect of several biotic and abiotic factors on the pattern of competition between two strains of Rhizobium japonicum was examined. In two Minnesota soils, Waseca and Waukegan, strain USDA 123 occupied 69% (Waseca) and 24% (Waukegan) of the root nodules on Glycine max L. Merrill cv. Chippewa. USDA 110 occupied 2% of the root nodules in the Waseca soil and 12% of the nodules in the Waukegan soil. Under a variety of other growth conditions—vermiculite, vermiculite amended with Waseca soil...

  20. Aerobic purification of hydrogenase from Rhizobium japonicum by affinity chromatography.

    OpenAIRE

    Stults, L W; Moshiri, F.; Maier, R J

    1986-01-01

    We purified active hydrogenase from free-living Rhizobium japonicum by affinity chromatography. The uptake hydrogenase of R. japonicum has been treated previously as an oxygen-sensitive protein. In this purification, however, reducing agents were not added nor was there any attempt to exclude oxygen. In fact, the addition of sodium dithionite to aerobically purified protein resulted in the rapid loss of activity. Purified hydrogenase was more stable when stored under O2 than when stored under...

  1. Evaluation of Nitrate Reductase Activity in Rhizobium japonicum†

    OpenAIRE

    Streeter, John G.; DeVine, Paul J.

    1983-01-01

    Nitrate reductase activity was evaluated by four approaches, using four strains of Rhizobium japonicum and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase.

  2. Dechlorination of Atrazine by a Rhizobium sp. Isolate

    OpenAIRE

    Bouquard, C.; Ouazzani, J.; Prome, J.; Michel-Briand, Y.; Plesiat, P

    1997-01-01

    A Rhizobium sp. strain, named PATR, was isolated from an agricultural soil and found to actively degrade the herbicide atrazine. Incubation of PATR in a basal liquid medium containing 30 mg of atrazine liter(sup-1) resulted in the rapid consumption of the herbicide and the accumulation of hydroxyatrazine as the only metabolite detected after 8 days of culture. Experiments performed with ring-labeled [(sup14)C]atrazine indicated no mineralization. The enzyme responsible for the hydroxylation o...

  3. Protozoa and the decline of Rhizobium populations added to soil.

    Science.gov (United States)

    Danso, S K; Keya, S O; Alexander, M

    1975-06-01

    A fall in Rhizobium abundance occurred in nonsterile soil inoculated with large numbers of the root-nodule bacteria, but many of the rhizobia still survived. No such decline was evident in sterile soil. Protozoa feeding on these bacteria were isolated from soil and other environments. As the abundance of Rhizobium meliloti and a cowpea Rhizobium strain in soil decreased, the protozoan density increased. The inability of the predators to eliminate their prey from soil was not the result of the presence of organisms feeding on the protozoa because many rhizobia survived in sterile soil inoculated with the prey and cultures of individual protozoa, nor was it the result of the rapid multiplication of the bacteria to replace those consumed because survivors were still numerous in essentially organic matter free soil in which the bacteria did not grow appreciably. The lack of elimination also was not associated with a protective effect of soil particles because survivors were still abundant in solutions inoculated with protozoa and bacteria. It is suggested that the size of the prey population diminishes until a density is attained at which the energy used by the predator in hunting for the survivors equals that obtained from the feeding. PMID:807307

  4. CSTB - Priorité scientifique et technique "Maîtrise des Risques" : bilan 2010-2013, rapport final

    OpenAIRE

    Vallerent, S.; Blanchard, E.; Delpech, P.; Demouge, F.; Florence, C.; Pimienta, P; Salagnac, J.L.; Carlotti, P.

    2014-01-01

    La priorité scientifique et technique "Maîtrise des Risques" du programme de recherche 2010-2013 du CSTB avait pour ambition de contribuer à éviter les victimes en protégeant les personnes présentes dans le bâti, de limiter les dommages économiques en protégeant les biens et d'assurer la résilience tant technique qu'humaine. Les travaux portaient sur les risques naturels et anthropiques (incendie, vent, séisme, canicule...) et étaient organisés en quatre projets de recherche. Ce ...

  5. Effects of nano-TiO2 on the agronomically-relevant Rhizobium-legume symbiosis

    Science.gov (United States)

    The impact of nano-TiO2 on Rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure to nano-TiO2 did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. However, nano-...

  6. Large-Scale Production of Rhizobium meliloti on Whey †

    OpenAIRE

    Bissonnette, N.; Lalande, R; Bordeleau, L M

    1986-01-01

    Whey, a by-product of the cheese industry, can sustain the growth of fast-growing rhizobia. To avoid any latency of growth, rhizobial inoculum must be prepared under inducing conditions. In unsupplemented whey, the number of cells of Rhizobium meliloti Balsac reached 5 × 109 CFU/ml in 48 h of incubation. This is comparable to the yield obtained with yeast-mannitol broth, the standard medium for the growth of rhizobia. In raw whey supplemented with yeast extract (1.0 g/liter) and phosphate (0...

  7. Antimicrobial activity of Rhizobium sp. strains against Pseudomonas savastanoi, the agent responsible for the olive knot disease in Algeria

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available In the present investigation, six Rhizobium strains isolated from Algerian soil were checked for their antimicrobial activity against Pseudomonas savastanoi, the agent responsible for olive knot disease. Rhizobium sp. ORN 24 and ORN 83 were found to produce antimicrobial activities against Pseudomonas savastanoi. The antimicrobial activity produced by Rhizobium sp. ORN24 was precipitable with ammonium sulfate, between 1,000 and 10,000 KDa molecular weight, heat resistant but sensitive to proteases and detergents. These characteristics suggest the bacteriocin nature of the antimicrobial substance produced by Rhizobium sp. ORN24, named rhizobiocin 24. In contrast, the antimicrobial activity produced by Rhizobium sp. ORN83 was not precipitable with ammonium sulfate; it was smaller than 1,000 KDa molecular weight, heat labile, and protease and detergent resistant. These characteristics could indicate the relationship between the antimicrobial substance produced by Rhizobium sp. ORN 83 and the “small” bacteriocins described in other rhizobia.

    En la presente investigación, seis cepas de Rhizobium aisladas de suelos argelinos fueron estudiadas para conocer su actividad antimicrobiana contra Pseudomonas savastanoi, el agente causante de la tuberculosis del olivo. Rhizobium sp. ORN 24 y ORN 83 produjeron actividad antimicrobiana contra Pseudomonas savastanoi. La actividad antimicrobiana producida por Rhizobium sp. ORN 24 precipitó con sulfato amónico, tuvo un peso molecular entre 1000 y 10000 KDa, fue resistente al calor pero sensible a proteasas y detergentes. Estas características sugieren que la sustancia antimicrobial producida por Rhizobium sp. ORN 24 es la bacteriocina natural conocida como rizobiocina 24. Por el contrario, la actividad antimicrobiana producida por Rhizobium sp. ORN83 no fue precipitable con sulfato amónico, y tuvo un peso molecular menor de 1000 KDa, fue lábil al calor y resistente a detergentes y proteasas. Estas características podrían indicar una relación de la sustancia antimicrobiana producida por Rhizobium sp. ORN83 con la “pequeña” bacteriocina descrita en otros Rhizobium.

  8. Dynamics of genome architecture in Rhizobium sp. strain NGR234.

    Science.gov (United States)

    Mavingui, Patrick; Flores, Margarita; Guo, Xianwu; Dávila, Guillermo; Perret, Xavier; Broughton, William J; Palacios, Rafael

    2002-01-01

    Bacterial genomes are usually partitioned in several replicons, which are dynamic structures prone to mutation and genomic rearrangements, thus contributing to genome evolution. Nevertheless, much remains to be learned about the origins and dynamics of the formation of bacterial alternative genomic states and their possible biological consequences. To address these issues, we have studied the dynamics of the genome architecture in Rhizobium sp. strain NGR234 and analyzed its biological significance. NGR234 genome consists of three replicons: the symbiotic plasmid pNGR234a (536,165 bp), the megaplasmid pNGR234b (>2,000 kb), and the chromosome (>3,700 kb). Here we report that genome analyses of cell siblings showed the occurrence of large-scale DNA rearrangements consisting of cointegrations and excisions between the three replicons. As a result, four new genomic architectures have emerged. Three consisted of the cointegrates between two replicons: chromosome-pNGR234a, chromosome-pNGR234b, and pNGR234a-pNGR234b. The other consisted of a cointegrate of the three replicons (chromosome-pNGR234a-pNGR234b). Cointegration and excision of pNGR234a with either the chromosome or pNGR234b were studied and found to proceed via a Campbell-type mechanism, mediated by insertion sequence elements. We provide evidence showing that changes in the genome architecture did not alter the growth and symbiotic proficiency of Rhizobium derivatives. PMID:11741857

  9. An Experimental Test of the Rhizopine Concept in Rhizobium meliloti.

    Science.gov (United States)

    Gordon, D M; Ryder, M H; Heinrich, K; Murphy, P J

    1996-11-01

    In some Rhizobium-legume symbioses, compounds known as rhizopines are synthesized by bacteroids and subsequently catabolized by free-living cells of the producing strain. It has been suggested than rhizopines act as proprietary growth substrates and enhance the competitive ability of the producing strain in its interactions with the diverse microbial community found within the rhizosphere. Wild-type, rhizopine-producing Rhizobium meliloti L5-30 and mutant L5-30 strains deficient for either rhizopine synthesis or catabolism were inoculated onto lucerne host plants in competition experiments. These experiments demonstrated that no apparent advantage resulted from the ability to synthesize a rhizopine, whereas the ability to catabolize rhizopine provided a clear advantage when an organism was in competition with a strain without this ability. The results suggest that when an organism is in competition with a catabolism-deficient mutant, the ability to catabolize rhizopine results in enhanced rates of nodulation. The results of the experiments were not consistent with the hypothesis that the sole role of rhizopines is to act as proprietary growth substrates for the free-living population of the producing strain. PMID:16535438

  10. A rhizobium leguminosarum mutant defective in symbiotic iron acquisition

    International Nuclear Information System (INIS)

    Iron acquisition by symbiotic Rhizobium spp. is essential for nitrogen fixation in the legume root nodule symbiosis. Rhizobium leguminosarum 116, an ineffective mutant strain with a defect in iron acquisition, was isolated after nitrosoguanidine mutagenesis of the effective strain 1062. The pop-1 mutation in strain 116 imparted to it a complex phenotype, characteristic of iron deficiency. Several iron(III)-solubilizing agents, such as citrate, hydroxyquinoline, and dihydroxybenzoate, stimulated growth of 116 on low-iron solid medium; anthranilic acid, the R. leguminosarum siderophore, inhibited low-iron growth of 116. The initial rate of 55Fe uptake by suspensions of iron-starved 116 cells was 10-fold less than that of iron-starved wild-type cells. Electron microscopic observations revealed no morphological abnormalities in the small, white nodules induced by 116. Nodule cortical cells were filled with vesicles containing apparently normal bacteroids. No premature degeneration of bacteroids or of plant cell organelles was evident. The authors mapped pop-1 by R plasmid-mediated conjugation and recombination to the ade-27-rib-2 region of the R. leguminosarum chromosome. No segregation of pop-1 and the symbiotic defect was observed among the recombinants from these crosses. Cosmid pKN1, a pLAFR1 derivative containing a 24-kilobase-pair fragment of R. leguminosarum DNA, conferred on 116 the ability to grow on dipyridyl medium and to fix nitrogen symbioticallymedium and to fix nitrogen symbiotically

  11. Evidence of an American origin for symbiosis-related genes in Rhizobium lusitanum.

    Science.gov (United States)

    Valverde, Angel; Velázquez, Encarna; Cervantes, Emilio; Igual, José M; van Berkum, Peter

    2011-08-15

    Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the Arcos de Valdevez region of northwestern Portugal. The isolates were divided into 6 groups based on the fingerprint patterns that were obtained. Representatives for each group were selected for sequence analysis of 4 chromosomal DNA regions. Five of the groups were placed within Rhizobium lusitanum, and the other group was placed within R. tropici type IIA. Therefore, the collection of Portuguese bean isolates was shown to include the two species R. lusitanum and R. tropici. In plant tests, the strains P1-7, P1-1, P1-2, and P1-16 of R. lusitanum nodulated and formed nitrogen-fixing symbioses both with Phaseolus vulgaris and Leucaena leucocephala. A methyltransferase-encoding nodS gene identical with the R. tropici locus that confers wide host range was detected in the strain P1-7 as well as 24 others identified as R. lusitanum. A methyltransferase-encoding nodS gene also was detected in the remaining isolates of R. lusitanum, but in this case the locus was that identified with the narrow-host-range R. etli. Representatives of isolates with the nodS of R. etli formed effective nitrogen-fixing symbioses with P. vulgaris and did not nodulate L. leucocephala. From sequence data of nodS, the R. lusitanum genes for symbiosis were placed within those of either R. tropici or R. etli. These results would support the suggestion that R. lusitanum was the recipient of the genes for symbiosis with beans from both R. tropici and R. etli. PMID:21705533

  12. Structures of the lipopolysaccharides from Rhizobium leguminosarum RBL5523 and its UDP-glucose dehydrogenase mutant (exo5).

    Science.gov (United States)

    Muszynski, Artur; Laus, Marc; Kijne, Jan W; Carlson, Russell W

    2011-01-01

    Rhizobial lipopolysaccharide (LPS) is required to establish an effective symbiosis with its host plant. An exo5 mutant of Rhizobium leguminosarum RBL5523, strain RBL5808, is defective in UDP-glucose (Glc) dehydrogenase that converts UDP-Glc to UDP-glucuronic acid (GlcA). This mutant is unable to synthesize either UDP-GlcA or UDP-galacturonic acid (GalA) and is unable to synthesize extracellular and capsular polysaccharides, lacks GalA in its LPS and is defective in symbiosis (Laus MC, Logman TJ, van Brussel AAN, Carlson RW, Azadi P, Gao MY, Kijne JW. 2004. Involvement of exo5 in production of surface polysaccharides in Rhizobium leguminosarum and its role in nodulation of Vicia sativa subsp. nigra. J Bacteriol. 186:6617-6625). Here, we determined and compared the structures of the RBL5523 parent and RBL5808 mutant LPSs. The parent LPS core oligosaccharide (OS), as with other R. leguminosarum and Rhizobium etli strains, is a Gal(1)Man(1)GalA(3)Kdo(3) octasaccharide in, which each of the GalA residues is terminally linked. The core OS from the mutant lacks all three GalA residues. Also, the parent lipid A consists of a fatty acylated GlcNGlcNonate or GlcNGlcN disaccharide that has a GalA residue at the 4'-position, typical of other R. leguminosarum and R. etli lipids A. The mutant lipid A lacks the 4'-GalA residue, and the proximal glycosyl residue was only present as GlcNonate. In spite of these alterations to the lipid A and core OSs, the mutant was still able to synthesize an LPS containing a normal O-chain polysaccharide (OPS), but at reduced levels. The structure of the OPS of the mutant LPS was identical to that of the parent and consists of an O-acetylated ?4)-?-d-Glcp-(1?3)-?-d-QuipNAc-(1? repeating unit. PMID:20817634

  13. Pré-seleção de estirpes de Rhizobium sp. para amendoim Preliminary selection of peanut Rhizobium sp. strains

    Directory of Open Access Journals (Sweden)

    Antonio Roberto Giardini

    1984-01-01

    Full Text Available Um ensaio foi conduzido em casa de vegetação, com solução nutritiva isenta de N, com o objetivo de selecionar estirpes de Rhizobium eficientes fixadoras de N2, quando associadas com amendoim (Arachis hypogaea L. cultivar Tatu. Foram testadas 35 estirpes de Rhizobium sp., isoladas de quinze diferentes espécies de leguminosas tropicais, e incluído um tratamento de inoculação com solo previamente cultivado com amendoim. Das 35 estirpes testadas, doze formaram nódulos e, entre essas, sete foram eficientes fixadoras de nitrogênio. Das doze estirpes que nodularam, sete foram isoladas de leguminosas da tribo Hedysareae (à qual pertence o género Arachis e, destas, apenas quatro foram eficientes fixadoras de nitrogênio. O peso e o número de nódulos não se mostraram como critérios adequados para avaliação da eficiência.An experiment was carried out in Leonard jars, in the greenhouse, with nitrogen-free nutrient solution to test the efficiency of 35 strains of rhizobia isolated from 15 species of tropical legumes. Twelve of the tested strains were capable of nodule formation in peanut. Seven of those strains were isolated from the trible Hedysareae, which includes the genus Arachis. Only four of the rhizobia strains with inducing nodulation were effective. Dry weight and number of nodules were not good criteria for evaluating effectiveness.

  14. Nitrogen fixing capacity of some soybean cultivars inoculated with different Rhizobium japonicum strains

    International Nuclear Information System (INIS)

    The nitrogen-fixing efficiency of different Rhizobium japonicum strains was tested. The strains were inoculated into three soybean cultivars and grain yield, total nitrogen content and nitrogen-fixing capacity were determined. 4 refs, 1 tab

  15. Antimicrobial activities of Rhizobium sp. strains against Pseudomonas savastanoi, the agent responsible for the olive knot disease in Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Mourad, K.; Fadhila, K.; Chahinez, M.; Merien, R.; Philippe, L. de; Abdelkader, B.

    2009-07-01

    In the present investigation, six Rhizobium strains isolated from Algerian soil were checked for their antimicrobial activity against Pseudomonas savastanoi, the agent responsible for olive knot disease. Rhizobium sp. ORN 24 and ORN 83 were found to produce antimicrobial activities against Pseudomonas savastanoi. The antimicrobial activity produced by Rhizobium sp. ORN24 was precipitable with ammonium sulfate, between 1,000 and 10,000 KDa molecular weight, heat resistant but sensitive to proteases and detergents. These characteristics suggest the bacteriocin nature of the antimicrobial substance produced by Rhizobium sp. ORN24, named rhizobiocin 24. In contrast, the antimicrobial activity produced by Rhizobium sp. ORN83 was not precipitable with ammonium sulfate; it was smaller than 1,000 KDa molecular weight, heat labile, and protease and detergent resistant. These characteristics could indicate the relationship between the antimicrobial substance produced by Rhizobium sp. ORN 83 and the small bacteriocins described in other rhizobia. (Author) 51 refs.

  16. Dilution of Liquid Rhizobium Cultures To Increase Production Capacity of Inoculant Plants †

    OpenAIRE

    Somasegaran, Padmanabhan; Halliday, Jake

    1982-01-01

    Experiments were undertaken to test whether peat-based legume seed inoculants, which are prepared with liquid cultures that have been deliberately diluted, can attain and sustain acceptable numbers of viable rhizobia. Liquid cultures of Rhizobium japonicum and Rhizobium phaseoli were diluted to give 108, 107, or 106 cells per ml, using either deionized water, quarter-strength yeast-mannitol broth, yeast-sucrose broth, or yeast-water. The variously diluted cultures were incorporated into gamma...

  17. Narrow- and Broad-Host-Range Symbiotic Plasmids of Rhizobium spp. Strains That Nodulate Phaseolus vulgaris

    OpenAIRE

    Brom, Susana; Martinez, Esperanza; Dávila, Guillermo; Palacios, Rafael

    1988-01-01

    Agrobacterium transconjugants containing symbiotic plasmids from different Rhizobium spp. strains that nodulate Phaseolus vulgaris were obtained. All transconjugants conserved the parental nodulation host range. Symbiotic (Sym) plasmids of Rhizobium strains isolated originally from P. vulgaris nodules, which had a broad nodulation host range, and single-copy nitrogenase genes conferred a Fix+ phenotype to the Agrobacterium transconjugants. A Fix? phenotype was obtained with Sym plasmids of ...

  18. Density Centrifugation Method for Recovering Rhizobium spp. from Soil for Fluorescent-Antibody Studies †

    OpenAIRE

    Wollum, A. G.; Miller, R.H.

    1980-01-01

    A density centrifugation procedure has been developed as a replacement for soil flocculation and clarification steps employed in quantitative fluorescent-antibody studies on Rhizobium in soils. Near-quantitative recovery of added cells of two strains of Rhizobium japonicum and two strains of R. phaseoli was achieved from six soils with various properties. It is proposed that this technique may prove useful in separating other soil microorganisms from soil particles in ecological studies emplo...

  19. Sobrevivência e nodulação do Rhizobium tropici em sementes de feijão tratadas com fungicidas

    Directory of Open Access Journals (Sweden)

    Araújo Ademir Sérgio Ferreira de

    2006-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a sobrevivência e a capacidade de nodulação do Rhizobium tropici em sementes de feijão tratadas com fungicidas. O estudo foi realizado em laboratório e em casa de vegetação. Sementes de feijão (Phaseolus vulgaris foram tratadas com seis diferentes fungicidas e inoculadas com Rhizobium tropici estirpe CIAT 899. A sobrevivência do Rhizobium nas sementes foi avaliada no tempo 0 e 24 horas após o tratamento com fungicidas e a inoculação, utilizando o método do número mais provável (NMP. A nodulação do feijão, em plantio realizado no tempo 0 e 24 horas após o tratamento com fungicidas, e a inoculação foram avaliadas em solo com população estabelecida de Rhizobium nativo aos trinta dias após a emergência das plantas. A sobrevivência do Rhizobium inoculado nas sementes foi prejudicada pela aplicação dos fungicidas avaliados. A nodulação do feijoeiro foi reduzida pela aplicação dos fungicidas, quando o plantio foi realizado 24 horas após o tratamento das sementes. Entretanto, foram encontrados nódulos em todos os tratamentos, evidenciando que houve nodulação do Rhizobium nativo do solo.

  20. Strain identification in Rhizobium by starch gel electrophoresis of isoenzymes

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen; Nielsen, G.

    1985-01-01

    Sonieated extracts of rhizobia, especiaUy Rhizobium leguminosarum from pea and vetch, were run in horizontal starch gel electrophoresis in the cold. The rhizobia were grown on agar on a slime suppressing substrate of tryptone-yeast extract-CaCl2 with small amounts of mannitol, sorbitol and arabinose and other sugars as enzyme inducers. After electrophoresis the gels were separated into several slabs by a gel cutter. Each slab was stained for a particular enzyme. Among numerous enzyme systems tested we found useful variation in esterases (EC 3.1.1.1, EC 3.1.1.2), 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30), mannitol dehydrogenase (EC 1.1.1.67), and arabinose dehydrogenase (EC 1.1.1.46). It was possible to distinguish at least 7 different types of pea rhizobia among 16 strains isolated from one batch of 5 kg soil.

  1. Endocarditis infecciosa por Rhizobium radiobacter: Reporte de un caso / Infective endocarditis by Rhizobium radiobacter: A case report

    Scientific Electronic Library Online (English)

    Jean Félix, Piñerúa Gonsálvez; Rosanna del Carmen, Zambrano Infantino; Carlos, Calcaño; César, Montaño; Zaida, Fuenmayor; Henry, Rodney; Marianela, Rodney.

    2013-03-01

    Full Text Available Rhizobium radiobacter es una bacteria Gram-negativa, fijadora de nitrógeno que se encuentra principalmente en el suelo. Rara vez causa infecciones en humanos. Ha sido asociada a bacteriemia secundaria a colonización de catéteres intravasculares en pacientes inmunocomprometidos. El objetivo de este t [...] rabajo es informar un caso de endocarditis infecciosa por R. radiobacter. Se trata de paciente masculino, de 47 años de edad, con diagnóstico de enfermedad renal crónica estadio 5 en tratamiento sustitutivo con hemodiálisis, quien acude a centro asistencial por presentar fiebre de dos semanas de evolución. Es hospitalizado, se toman muestras de sangre periférica para hemocultivo y se inicia antibioticoterapia empírica con cefotaxime más vancomicina. El ecocardiograma transtorácico revelo vegetación fusiforme en válvula tricúspide con regurgitación grado III-IV/IV. Al séptimo día del inicio de la antibioterapia el paciente presenta mejoría clínica y paraclínica. La bacteria identificada por hemocultivo es Rhizobium radiobacter resistente a ceftriaxona y sensible a imipenem, amikacina, ampicilina y ampicilina/sulbactam. Debido a la mejoría clínica se decide continuar tratamiento con vancomicina y se anexa imipenem. A los 14 días de iniciada la antibioterapia el paciente es dado de alta con tratamiento ambulatorio con imipenen hasta cumplir seis semanas de tratamiento. En el ecocardiograma control se evidencio ausencia de la vegetación en la válvula tricúspide. Este caso sugiere que R. radiobacter puede ser una causa de endocarditis en pacientes portadores de catéteres intravasculares. Abstract in english Rhizobium radiobacter is a Gram-negative, nitrogen-fixing bacterium, which is found mainly on the ground. It rarely causes infections in humans. It has been associated with bacteremia, secondary to colonization of intravascular catheters, in immunocompromised patients. The aim of this paper was to r [...] eport the case of an infective endocarditis caused by R. radiobacter, in a 47-year-old male, diagnosed with chronic kidney disease stage 5, on replacement therapy with hemodialysis and who attended the medical center with fever of two weeks duration. The patient was hospitalized and samples of peripheral blood were taken for culture. Empirical antibiotic therapy was started with cefotaxime plus vancomycin. The transthoracic echocardiogram revealed fusiform vegetation on the tricuspid valve, with grade III-IV/IV regurgitation. On the seventh day after the start of antibiotic therapy, the patient had a clinical and paraclinical improvement. The bacterium identified by blood culture was Rhizobium radiobacter, ceftriaxone-resistant and sensitive to imipenem, amikacin, ampicillin and ampicillin/ sulbactam. Because of the clinical improvement, it was decided to continue treatment with vancomycin and additionally, with imipenem. At 14 days after the start of antibiotic therapy, the patient was discharged with outpatient treatment with imipenem up to six weeks of treatment. The control echocardiogram showed the absence of vegetation on the tricuspid valve. This case suggests that R. radiobacter can cause endocarditis in patients with intravascular catheters.

  2. Rhizobium grahamii sp. nov., from nodules of Dalea leporina, Leucaena leucocephala and Clitoria ternatea, and Rhizobium mesoamericanum sp. nov., from nodules of Phaseolus vulgaris, siratro, cowpea and Mimosa pudica.

    Science.gov (United States)

    López-López, Aline; Rogel-Hernández, Marco A; Barois, Isabelle; Ortiz Ceballos, Angel I; Martínez, Julio; Ormeño-Orrillo, Ernesto; Martínez-Romero, Esperanza

    2012-09-01

    Two novel related Rhizobium species, Rhizobium grahamii sp. nov. and Rhizobium mesoamericanum sp. nov., were identified by a polyphasic approach using DNA-DNA hybridization, whole-genome sequencing and phylogenetic and phenotypic characterization including nodulation of Leucaena leucocephala and Phaseolus vulgaris (bean). As similar bacteria were found in the Los Tuxtlas rainforest in Mexico and in Central America, we suggest the existence of a Mesoamerican microbiological corridor. The type strain of Rhizobium grahamii sp. nov. is CCGE 502(T) (= ATCC BAA-2124(T) = CFN 242(T) = Dal4(T) = HAMBI 3152(T)) and that of Rhizobium mesoamericanum sp. nov. is CCGE 501(T) (= ATCC BAA-2123(T) = HAMBI 3151(T) = CIP 110148(T) = 1847(T)). PMID:22081714

  3. Genome Sequence of Rhizobium grahamii CCGE502, a Broad-Host-Range Symbiont with Low Nodulation Competitiveness in Phaseolus vulgaris

    OpenAIRE

    Althabegoiti, M. Julia; Lozano, Luis; Torres-Tejerizo, Gonzalo; Ormeño-Orrillo, Ernesto; Rogel, Marco A; González, Víctor; Martínez-Romero, Esperanza

    2012-01-01

    Here we present the genome sequence of Rhizobium grahamii CCGE502. R. grahamii groups with other newly described broad-host-range species, which are not very efficient Phaseolus vulgaris symbionts, with a wide geographic distribution and which constitutes a novel Rhizobium clade.

  4. Draft Genome Sequence of a Phthalate Ester-Degrading Bacterium, Rhizobium sp. LMB-1, Isolated from Cultured Soil

    Science.gov (United States)

    Tang, Wen-Juan

    2015-01-01

    Rhizobium sp. LMB-1, newly isolated from greenhouse soil, can effectively degrade phthalate. Here, we present a 5.2-Mb assembly of this Rhizobium sp. genome for the first time. It may provide abundant molecular information for the transformation of phthalates. PMID:25953182

  5. Interacción micorriza vesiculo-arbuscular, Rhizobium leguminosa en un oxisol de los Llanos Orientales de Colombia

    Directory of Open Access Journals (Sweden)

    Satizabal E. Jorge H.

    1987-03-01

    Full Text Available En los dos primeros trabajos (la y lb, se evaluó la interacción entre cepas seleccionadas de Rhizobium (apropiadas para la leguminosa forrajera tropical Centrosema macrocarpum y especies (Entrophospora colombiana, Acaulospora longula, Glomus manihotis de micorriza vesiculo arbuscular (MVA, en un suelo esterilizado, fijador de P. Los experimentos se diferenciaron por las fuentes de P utilizadas. Por su mayor producción de materia seca, absorción de minerales, nodulación y infección por MVA, se destacaron las plantas inoculadas con cuales quiera de las cepas de FIlizobiumy Glomus manihotis (Experimento la o Acaulospora longula (Experimento lb. En la tercera investigación (Experimento II, se evalúo en Centrosema la interacción MVA, Rhizobiumo N-químico (niveles equivalentes a 0, 30,55, 105,0 + Rhiz. y 30 + Rhiz. kg N ha-1 y dosis de P (0, 20, 40 y 80 kg ha-1. Es aconsejable aplicar pequeñas dosis (30 kg ha-1 de N al momento de la siembra e inocular con Rhizobium. Plantas inoculadas con MVA presentaron su óptimo crecimiento con 40 kg P ha-1. Dosis de 80 kg P ha-1 favoreció la eficiencia de la bacteria más no la del hongo.In the first two works (la and lb we evaluated the interation between selected stumps of Rhizobium (appropiate for the tropical forage legumes Centrosema macrocarpum and species (Entrophospora colombiana, Acaulospora longula, Glomus manihotis of vesicular-arbuscular mycorrhiza (MVA, in a sterelize soil fixer of P. The two experiments are different because we used different P sources. For the best production of dry matter, absorption of minerals, nodulation and infection for MVA; rebounded the plants with the inoculation with any of the Rhizobium´s stumps and Glomus manihotis (Experiment la of Acaulospora longula (Experiment lb. In the third investigation (Experiment II we evaluated in Centrosema the interaction MVA. Rhizobium and chemical N (levels equivalent to 0,30. 55, 105, O + Rhizobium and 30 + Rhizobium kg N ha-1 and amount of P (O, 20, 40 and 80 kg ha-1. Is advisable to apply small amount (30 kg ha-1 of N fertilizer at the time of sowing the Centrosema and the inoculation with Rhizobium. The plants inoculated with MVA showed a best growing in the amount 40kg Pha -1 80 kg Pha -1 helped in the efficacy of the bacterium and it didn't help in the efficacy of the fungus.

  6. 78 FR 33437 - United States v. Apple, Inc., et al.; Public Comments and Response on Proposed Final Judgment

    Science.gov (United States)

    2013-06-04

    ...Antitrust Division United States v. Apple, Inc., et al.; Public Comments and...a Macmillan in United States v. Apple, Inc., et al., Civil Action No...STATES OF AMERICA, Plaintiff, v. APPLE, INC., et al., Defendants....

  7. The isolation, enumeration, and characterization of Rhizobium bacteria of the soil in Wamena Biological Garden

    Directory of Open Access Journals (Sweden)

    SRI PURWANINGSIH

    2005-04-01

    Full Text Available The eleven soil samples have been isolated and characterized. The aims of the study were to get the pure culture and some data which described about enumeration and especially their characters in relation to the acids and bases reaction in their growth. The isolation of the bacteria use Yeast Extract Mannitol Agar medium (YEMA while the characterization by using YEMA medium mixed with Brom Thymol Blue and Congo Red indicators respectively. The results showed that eighteen isolates have been isolated which consisted of three low growing and fifteen fast growing bacteria. Two isolates were not indicated Rhizobium and sixteen were Rhizobium. Density of Rhizobium enumeration was varied which related to soil organic matter content. The enumeration bacteria in YEMA medium were in the range of 0.6 x 105 and 11.6 x 105 CFU /g soil. The highest population was found in soil sample of Wieb vegetation.

  8. Cultivar and Rhizobium Strain Effects on the Symbiotic Performance of Pea (Pisum sativum)

    DEFF Research Database (Denmark)

    SkØt, Leif

    1983-01-01

    The symbiotic performance of four pea (Pisum sativum L.) cultivars in combination with each of four strains of Rhizobium leguminosarum was studied in growth chamber experiments in order to estimate the effects of cultivars, strains and cultivar × strain interaction on the variation in dry weight, N content and dry weight/N ratio. At harvest 63 days after planting, cultivars accounted for 75% of the variation in dry weight, while the Rhizobium strains accounted for 63% of the variation in N-content and 70% of the variation in dry weight/N ratio. Cultivar × strain interactions were statistically significant, but of minor quantitative importance, accounting for 5–15% of the total variation. Rhizobium strains also influenced the partitioning of N between reproductive and vegetative plant parts and between root and shoot biomass.

  9. Effect of Rhizobium and Mycorhiza inoculation on the nursery growth of Acacia and Teline monspessulana

    International Nuclear Information System (INIS)

    In an experiment accomplished in the tree nursery Tisquesusa located in Madrid (Cundinamarca) was evaluated the effect of the inoculation with strains selected of foreign and Indigenous rhizobium and Arbuscular mycorrhizal fungi am (Glomus folescutolum) on the growth, nitrogen fixation, and micorrization of Acacia (Acacia decurrens) and Retamo (Teline monspessulana) that they are used In soils recovery by the Corporacion Autonoma Regional de Cundinamarca CAR. The studied species presented positive response to the inoculation with rhizobium; the indigenous strain DQ6-09, isolated in Guatavita (Cundinamarca), presented the better results in Retamo and also in Acacia alone and in mixture with the foreign strain T1881. The inoculation with fungi AM increased the heights, dry weights, phosphorus content and percentage of micorrization in Acacia and Retamo. The double inoculation with fungi ma and rhizobium it did not increase the nitrogen fixing of Acacia while in Retamo was presented a positive effect with the strain DQ6-09

  10. Biologic fixation of nitrogen in irradiated rhizobium strips

    International Nuclear Information System (INIS)

    Native Rhizobium sp. and Bradyrhizobium sp. isolates from the root nodules of bean and cowpea were selected. Six isolates, and the SEMIA 4077 (R. leguminosarum bv. phaseolus) and SEMIA 6145 (Bradyrhizobium sp) strains used as references, were irradiated with ultraviolet light (R-uv) and gamma rays (R-?). The D37 values for the rhizobial strain SEMIA 4077 were 43 J.m-2 (UV) and 32 Gy (R-?) and for the SEMIA 6145 were 45 J.m-2 (UV) and 35 Gy (R-gamma). Through a greenhouse experiment the irradiated isolates were inoculated on bean (P. vulgaris L., cv. Princesa) and on cowpea [Vigna unguiculata, (L.) Walp, cv. IPA-206] seedlings, in an attempt to evaluate the sensitivity of the host plants, and possible effects on their nodulation. Differences in responses to nodulation due to the effect of irradiation were observed for the isolates tested. Significantly differences were observed only for nodules dry matter yield of the IPA-206 cultivar. Gamma irradiated treatment were statistically superior to treatments with ultraviolet light in relation. (author)

  11. Effect of Rhizobium Inoculants on Cowpea under Rainfed Condition

    Directory of Open Access Journals (Sweden)

    Sarker P. C.

    2001-01-01

    Full Text Available A 2-year on-farm experiment was conducted under rainfed condition to study the effect of Rhizobium inoculation (with or without chemical fertilizer and chemical fertilizer ( 0 and 50-30-20 Kg ha -1 P2O5, K2O and S on cowpea. Two sources of biofertilizer were used. Biofertilizer showed significantly higher yield attributes and seed yield of cowpea as compared to control. Biofertilizer of BARI source gave the highest cowpea seed yield (880 Kg ha -1 and the lowest seed yield (658 Kg ha -1 was obtained without biofertilizer. No significant difference was found between the two sources of bio-fertilizer. Chemical fertilizer showed better performance than control in case of seed yield and all yield contributing characters of cowpea. Interaction of bio-fertilizer and chemical fertilizer also showed statistically significant difference. PKS with biofertilizer of both BAU and BARI sources gave the highest seed yield (987 Kg ha -1 and the lowest seed yield (525 Kg ha -1 was obtained from control treatment. Though the highest average rate of return (4556% was found using biofertilizer of BARI source but on consideration of net return and also soil health, PKS with biofertilizer of BARI source where ARR was the second highest may be suggested for growing cowpea under rainfed condition.

  12. Studies on mutation and repair in Rhizobium japonicum

    International Nuclear Information System (INIS)

    In the presence of NTG, Rhizobium japonicum loses viability very rapidly. 50% survival is achieved within 4 mins using 50 ?gm/ml. When a constant time of 30 min is maintained then a concentration of 18 ?gm/ml gives 50% survival. The low doses of NTG did not yield any auxotrophs. The antibiotics like penicillion, ampicillin and streptopenicillin were used as agents for enrichment of mutants, ampicillin was quite effective. A fairly efficient mechanism for repair from U.V. damage appears to exist. A greater part of this repair is due to the prevalence of dark repair mechanism. Mutants with increased sensitivity to U.V. repair failed to transform normally suggesting that the two processes of U.V. repair and genetic recombination may be related. The levels of deoxyribonucleases increased at the competent state. The activity at pH 7.5 and 8.4 but not at 5.5 was greater towards irradiated DNA, a prerequisite for any enzyme involved in U.V. repair. (author)

  13. Influence of carbofuran on certain metabolic and symbiotic activities of a cowpea Rhizobium

    International Nuclear Information System (INIS)

    Using carbon 14 radioisotope an in-vitro study of the effect of insecticides, carbofuran, on the metabolic and symbiotic activities of Rhizobium sp. cowpea group, was carried out. The study indicated that at 10 ppm carbofuran inhibited the in-vitro growth of the bacterium, suppressed the oxidation of all the Trichloroacetic acid (TCA) cycle intermediates, significantly reduced glucose oxidation and translocation and affected the growth and symbiotic activities of the cowpea as reflected by a reduction in the dry matter production and total nitrogen content. The insecticide was itself degraded by the Rhizobium sp. within 30 days of incubation

  14. Genetic characterization and nitrogen fixation capacity of Rhizobium strains on common bean / Caracterização genética e capacidade de fixação de nitrogênio de estirpes de Rhizobium em feijoeiro

    Scientific Electronic Library Online (English)

    Tehuni Orlando, González; João Carlos, Campanharo; Eliana Gertrudes de Macedo, Lemos.

    1177-11-01

    Full Text Available O objetivo deste trabalho foi a caracterização genética de quatro novas estirpes de Rhizobium e a avaliação de sua capacidade de fixação de N2 e nodulação, comparadas a estirpes comerciais e à população nativa de rizóbios de um Latossolo Vermelho. Dois experimentos foram conduzidos em blocos ao acas [...] o, em casa de vegetação. No primeiro experimento, conduzido em tubetes com vermiculita, avaliaram-se a nodulação e a capacidade de fixação das novas estirpes, em comparação com as estirpes comerciais CIAT-899 e PRF-81 e com a população nativa do solo. Das colônias puras isoladas, extraiu-se o DNA genômico e realizou-se o seqüenciamento do espaço intergênico, para a caracterização genética das estirpes e da população nativa de rizóbios. O segundo experimento foi realizado em vasos com solo, para determinação da produtividade e da nodulação do feijoeiro, cultivar Pérola, com o uso das estirpes isoladamente ou em mistura com a PRF-81. A população nativa do solo foi identificada como Rhizobium sp. e se mostrou ineficiente na fixação de nitrogênio. Foram encontradas três espécies de Rhizobium entre as quatro novas estirpes. As estirpes LBMP-4BR e LBMP-12BR estão entre as que têm maior capacidade de nodulação e fixação de N2, e apresentam respostas diferenciadas quando misturadas à PRF-81. Abstract in english This study aimed to genetically characterize four new Rhizobium strains, and to evaluate their nodulation and fixation capacity compared to commercial strains and to native rhizobia population of a Brazilian Rhodic Hapludox. Two experiments were carried out in randomized blocks design, under greenho [...] use conditions, in 2007. In the first experiment, the nodulation and nitrogen fixation capacity of new strains were evaluated, in comparison to the commercial strains CIAT-899 and PRF-81 and to native soil population. It was carried out in plastic tubes filled with vermiculite. DNA extractions and PCR sequencing of the intergenic space were made from the isolated pure colonies, in order to genetically characterize the strains and the native rhizobia population. In the second experiment, the nodulation and productivity of common beans Perola cultivar were determined, with the use of evaluated strains, alone or in mixture with PRF-81 strain. It was carried out in pots filled with soil. The native soil population was identified as Rhizobium sp. and was inefficient in nitrogen fixation. Three different Rhizobium species were found among the four new strains. The LBMP-4BR and LBMP-12BR new strains are among the ones with greatest nodulation and fixation capacity and exhibit differential responses when mixed to PRF-81.

  15. Inoculant Production with Diluted Liquid Cultures of Rhizobium spp. and Autoclaved Peat: Evaluation of Diluents, Rhizobium spp., Peats, Sterility Requirements, Storage, and Plant Effectiveness

    OpenAIRE

    Somasegaran, P.

    1985-01-01

    Fully grown broth cultures of various fast- and slow-growing rhizobia were deliberately diluted with various diluents before their aseptic incorporation into autoclaved peat in polypropylene bags (aseptic method) or mixed with the peat autoclaved in trays (tray method). In a factorial experiment with the aseptic method, autoclaved and irradiated peat samples from five countries were used to prepare inoculants with water-diluted cultures of three Rhizobium spp. When distilled water was used as...

  16. Analysis of C4-dicarboxylate transport genes in Rhizobium meliloti.

    Science.gov (United States)

    Yarosh, O K; Charles, T C; Finan, T M

    1989-06-01

    A 5.1 kbp DNA fragment was isolated which complemented C4-dicarboxylate transport mutants (dct) of Rhizobium meliloti. Characterization of this fragment by subcloning, transposon mutagenesis, and complementation analysis revealed three loci, designated dctA, dctB, and dctD. TnphoA-generated alkaline phosphatase fusions to dctA suggested that this gene encodes the structural transport protein and allowed the determination of its direction of transcription. Analysis of the fusions in various mutant backgrounds demonstrated that dctB, dctD, and ntrA products are required for dctA expression. The dctA fusion was constitutively expressed in a dctA mutant background, but was not expressed in dctA dctB or dctA dctD double mutants. This suggests that the constitutive expression in a dctA mutant background is mediated through dctB and dctD. Three independent second-site Dct+ revertant mutations in ntrA mutant strains mapped to the dct locus. Succinate transport in these revertant strains was constitutive, whereas in the wild type, succinate transport was inducible. These results are consistent with the direct requirement of the ntrA gene product for dctA expression. Alfalfa plants inoculated with the dctB and dctD mutants showed reduced nitrogen-fixing activity. Nodules induced by dctA mutants failed to fix nitrogen. These symbiotic phenotypes are consistent with previous suggestions that dctA expression in bacteroids can occur independently of dctB and dctD. PMID:2546011

  17. Rhizobium freirei sp. nov., a symbiont of Phaseolus vulgaris that is very effective at fixing nitrogen.

    Science.gov (United States)

    Dall'Agnol, Rebeca Fuzinatto; Ribeiro, Renan Augusto; Ormeño-Orrillo, Ernesto; Rogel, Marco Antonio; Delamuta, Jakeline Renata Marçon; Andrade, Diva Souza; Martínez-Romero, Esperanza; Hungria, Mariangela

    2013-11-01

    Common bean (Phaseolus vulgaris L.) can establish symbiotic associations with several Rhizobium species; however, the effectiveness of most strains at fixing nitrogen under field conditions is very low. PRF 81(T) is a very effective strain, usually referred to as Rhizobium tropici and used successfully in thousands of doses of commercial inoculants for the common bean crop in Brazil; it has shown high rates of nitrogen fixation in all areas representative of the crop in the country. Here, we present results that indicate that PRF 81(T), although it belongs to the 'R. tropici group', which includes 10 Rhizobium species, R. tropici, R. leucaenae, R. lusitanum, R. multihospitium, R. miluonense, R. hainanense, R. calliandrae, R. mayense, R. jaguaris and R. rhizogenes, represents a novel species. Several morpho-physiological traits differentiated PRF 81(T) from related species. Differences were also confirmed in the analysis of rep-PCR (sharing less than 45?% similarity with the other species), MLSA with recA, atpD and rpoB genes, and DNA-DNA hybridization. The novel species, for which we propose the name Rhizobium freirei sp. nov., is able to establish effective root nodule symbioses with Phaseolus vulgaris, Leucaena leucocephala, Leucaena esculenta, Crotalaria juncea and Macroptilium atropurpureum. The type strain is PRF 81(T) (?=?CNPSo 122(T)?=?SEMIA 4080(T)?=?IPR-Pv81(T)?=?WDCM 440(T)). PMID:23771622

  18. Genetic derepression of a developmentally regulated lipopolysaccharide antigen from Rhizobium leguminosarum 3841.

    OpenAIRE

    Wood, E. A.; Butcher, G. W.; Brewin, N. J.; Kannenberg, E. L.

    1989-01-01

    Monoclonal antibody AFRC MAC 203 recognizes a developmentally regulated lipopolysaccharide antigen in Rhizobium leguminosarum bv. viciae 3841. Transposon-induced mutants that constitutively expressed MAC 203 antigen were isolated. These strains were morphologically normal, showed no gross abnormalities in lipopolysaccharide size distribution on sodium dodecyl sulfate-polyacrylamide gels, and induced normal nitrogen-fixing nodules. However, the mutants lacked lipopolysaccharide epitopes recogn...

  19. Visualization of Nodulation Gene Activity on the Early Stages of Rhizobium leguminosarum bv. viciae Symbiosis.

    Czech Academy of Sciences Publication Activity Database

    Chovanec, Pavel; Novák, Karel

    2005-01-01

    Ro?. 50, ?. 4 (2005), s. 323-331. ISSN 0015-5632 R&D Projects: GA ?R GA521/03/0192 Institutional research plan: CEZ:AV0Z50200510 Keywords : nodulation * rhizobium leguminosarum * vicia tetrasperma Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

  20. Genome Sequence of Rhizobium lupini HPC(L) Isolated from Saline Desert Soil, Kutch (Gujarat)

    OpenAIRE

    Agarwal, Leena; Purohit, Hemant J.

    2013-01-01

    The Rhizobium lupini strain HPC(L) was isolated from saline desert soil. It grows on minimal media supplemented with CaCO3 as a carbon source. It can also grow under both oligotrophic and heteroptrophic conditions. We report the annotated genome sequence of this strain in a 5.27-Mb scaffold.

  1. Mass spectrometric analysis of chitin oligosaccharides produced by Rhizobium NodC protein in Escherichia coli.

    OpenAIRE

    Kamst, E.; Drift, K. M.; Thomas-oates, J. E.; Lugtenberg, B. J.; Spaink, H. P.

    1995-01-01

    A system for studying the in vivo activity of Rhizobium NodC protein in Escherichia coli has been developed. Using thin-layer chromatography, high-performance liquid chromatography, and mass spectrometry, we show that in this system R. leguminosarum bv. viciae NodC protein directs the synthesis of chitinpentaose, chitintetraose, chitintriose, and two as yet unidentified modified chitin oligosaccharides.

  2. Fractionation of Rhizobium leguminosarum cells into outer membrane, cytoplasmic membrane, periplasmic, and cytoplasmic components.

    OpenAIRE

    Maagd, R. A.; Lugtenberg, B.

    1986-01-01

    Rhizobium leguminosarum cells were separated into four distinct fractions by using density gradient centrifugation for the separation of the outer and cytoplasmic membranes and lysozyme-EDTA treatment of whole cells for the isolation of the periplasmic and cytoplasmic fractions. These methods allowed the subcellular localization of R. leguminosarum proteins.

  3. Detection and subcellular localization of two Sym plasmid-dependent proteins of Rhizobium leguminosarum biovar viciae.

    OpenAIRE

    Maagd, R. A.; Wijffelman, C. A.; Pees, E.; Lugtenberg, B. J.

    1988-01-01

    The previously described Sym plasmid-dependent 24-kilodalton rhi protein of Rhizobium leguminosarum biovar viciae was localized in the cytosol fraction. Another Sym plasmid-dependent protein of 50 kilodaltons is secreted into the growth medium, and its expression is dependent on both the nodD gene and a nod gene inducer.

  4. Draft Genome Sequence of a Symbiotic Bacterium, Rhizobium vignae CCBAU 05176T

    OpenAIRE

    Liu, Yang; Yi, Zhiwei; Zeng, Runying

    2014-01-01

    The Rhizobium vignae strain CCBAU 05176T was isolated from a root nodule of Astragalus dahuricus grown in Hebei Province, China. It grows on yeast mannitol agar (YMA) supplemented with 0 to 2% (wt/vol) NaCl. We report the annotated genome sequence of this strain in a 6.34-Mb scaffold.

  5. Effects of Rhizobium inoculation on Trifolium resupinatum antioxidant system under sulfur dioxide pollution

    Directory of Open Access Journals (Sweden)

    Ladan Bayat

    2014-01-01

    Full Text Available Introduction: Plant growth stimulating rhizobacteria are beneficial bacteria that can cause resistance to various stresses in plants. One of these stresses is SO2 air pollution. SO2 is known as a strong damaging air pollutant that limits growth of plants. The aim of this study is evaluation of the effects of bacterial inoculation with native and standard Rhizobium on Persian clover root growth and antioxidants activity and capacity under air SO2 pollution. Materials and methods: In this study, 31 days plants (no-inoculated and inoculated with two strains of Rhizobium exposed to the different concentrations of SO2 (0 as a control, 0.5, 1, 1.5 and 2 ppm for 5 consecutive days and 2 hours per day. Results: Results showed different concentrations of SO2 had a significant effect on Persian clover root weight and antioxidant system. Increasing SO2 stress decreased root fresh and dry weight and antioxidant capacities (IC50 and increased antioxidant activities (I% of Persian clover leaves significantly in comparison to the control plants (under 0 ppm and increased SOD, CAT and GPX activity. Inoculation of Persian clover plants with native and standard Rhizobium increased root weight and did not show a significant effect on antioxidants activity and capacity, but interaction between Rhizobium inoculation and SO2 treatment reduced significantly the stress effects of high concentration of SO2 on root growth and antioxidants activity and capacity. In fact, level of this change of root growth and antioxidant system under SO2 pollution stress in inoculated plants was lower than in the non-inoculated plants. Discussion and conclusion: As a result, an increase in SO2 concentration caused a decrease in root weight, increase in antioxidants activity and capacity of Persian clover. Inoculation with Rhizobium strains could alleviate the effect of SO2 pollution on antioxidant system by effects on root growth.

  6. Random amplified polymorphic DNA analysis of effective Rhizobium sp. associated with beans cultivated in brazilian cerrado soils Caracterização, via RAPD, de estirpes efetivas de Rhizobium sp associadas ao feijoeiro cultivado em solos de cerrado no Brasil

    OpenAIRE

    Isnia Aparecida de Oliveira; Maria José Vasconcellos; Lucy Seldin; Edilson Paiva; Milton Alexandre Vargas; Nadja Maria Horta Sá

    2000-01-01

    Efficient bean nodulating Rhizobium strains, isolated from different Brazilian cerrado soils, were characterized by RAPD. This study showed great genetic heterogeneity among R. tropici and R. leguminosarum bv. phaseoli strains and allowed the constitution of genetic clusters, besides indicating the most suitable primers for this characterization. The groups of genetically distinct strains can be used in competitiveness studies to select appropriate Rhizobium strains for bean inoculation in ce...

  7. Rhizobium nodulation protein NodC is an important determinant of chitin oligosaccharide chain length in Nod factor biosynthesis.

    OpenAIRE

    Kamst, E.; Pilling, J.; Raamsdonk, L. M.; Lugtenberg, B. J.; Spaink, H. P.

    1997-01-01

    Synthesis of chitin oligosaccharides by NodC is the first committed step in the biosynthesis of rhizobial lipochitin oligosaccharides (LCOs). The distribution of oligosaccharide chain lengths in LCOs differs between various Rhizobium species. We expressed the cloned nodC genes of Rhizobium meliloti, R. leguminosarum bv. viciae, and R. loti in Escherichia coli. The in vivo activities of the various NodC proteins differed with respect to the length of the major chitin oligosaccharide produced. ...

  8. Effects of Inoculation with Rhizobium on Forage Yield and Yield Components of Common Vetch (Vicia sativa L.)

    OpenAIRE

    Albayrak, Sebahattin

    2004-01-01

    The effects of inoculation with Rhizobium on forage yield and yield components of common vetch (Vicia sativa L.) were evaluated under rainy conditions in Samsun, Turkey, in the 2001-2002 and 2002-2003 growing seasons. Common vetch cultivars Kubilay, Ürem, Kara elçi, Uluda?, Emir, Çubuk, Nilüfer and Rhizobium leguminosarum were used as materials. The experiment was established as a split block design with 3 replicates as averages of 2 years. While the highest forage and dry matter yields ...

  9. A small GTPase of the Rab family is required for root hair formation and preinfection stages of the common bean-Rhizobium symbiotic association.

    Science.gov (United States)

    Blanco, Flavio Antonio; Meschini, Eitel Peltzer; Zanetti, María Eugenia; Aguilar, O Mario

    2009-09-01

    Legume plants are able to establish a symbiotic relationship with soil bacteria from the genus Rhizobium, leading to the formation of nitrogen-fixing root nodules. Successful nodulation requires both the formation of infection threads (ITs) in the root epidermis and the activation of cell division in the cortex to form the nodule primordium. This study describes the characterization of RabA2, a common bean (Phaseolus vulgaris) cDNA previously isolated as differentially expressed in root hairs infected with Rhizobium etli, which encodes a protein highly similar to small GTPases of the RabA2 subfamily. This gene is expressed in roots, particularly in root hairs, where the protein was found to be associated with vesicles that move along the cell. The role of this gene during nodulation has been studied in common bean transgenic roots using a reverse genetic approach. Examination of root morphology in RabA2 RNA interference (RNAi) plants revealed that the number and length of the root hairs were severely reduced in these plants. Upon inoculation with R. etli, nodulation was completely impaired and no induction of early nodulation genes (ENODs), such as ERN1, ENOD40, and Hap5, was detected in silenced hairy roots. Moreover, RabA2 RNAi plants failed to induce root hair deformation and to initiate ITs, indicating that morphological changes that precede bacterial infection are compromised in these plants. We propose that RabA2 acts in polar growth of root hairs and is required for reorientation of the root hair growth axis during bacterial infection. PMID:19749154

  10. Chemical characterization of the gels produced by the diazotrophic bacteria Rhizobium tropici and Mesorhizobium sp; Caracterizacao quimica dos geis produzidos pelas bacterias diazotroficas Rhizobium tropici e Mesorhizobium sp.

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Nilson Kobori [Departamento de Engenharia e Tecnologia de Alimentos, Instituto de Biociencias, Letras e Ciencias Exatas, Universidade Estadual Paulista, Sao Jose do Rio Preto - SP (Brazil); Aranda-Selverio, Gabriel; Exposti, Diego Tadeu Degli; Silva, Maria de Lourdes Corradi da [Departamento de Fisica, Quimica e Biologia, Faculdade de Ciencias e Tecnologia, Universidade Estadual Paulista, Presidente Prudente - SP (Brazil); Lemos, Eliana Gertrudes Macedo; Campanharo, Joao Carlos [Departamento de Tecnologia, Faculdade de Ciencias Agrarias e Veterinaria, Universidade Estadual Paulista, Jaboticabal - SP (Brazil); Silveira, Joana Lea Meira [Departamento de Bioquimica e Biologia Molecular, Universidade Federal do Parana, Curitiba - PR (Brazil)

    2012-07-01

    The exopolysaccharides with characteristics of gel produced by Rhizobium tropici (EPSRT) and Mesorhizobium sp (EPSMR) are acidic heteropolysaccharide composed mainly of glucose and galactose in a molar ratio of 4:1 and 5:1 respectively, with traces of mannose ({approx} 1%). Chemical analysis showed the presence of uronic acid, pyruvate and acetyl-substituents in the structures of both polymers. Experiments of gel permeation chromatography and polyacrylamide gel electrophoresis showed that EPSRT and EPSMR are homogeneous molecules with low grade of polydispersity. The EPS were characterized using spectroscopic techniques of FT-IR, {sup 1}H and {sup 13}C-NMR. (author)

  11. Caracterização química dos géis produzidos pelas bactérias diazotróficas Rhizobium tropici e Mesorhizobium sp. / Chemical characterization of the gels produced by the diazotrophic bacteria Rhizobium tropici and Mesorhizobium sp.

    Scientific Electronic Library Online (English)

    Nilson Kobori, Monteiro; Gabriel, Aranda-Selverio; Diego Tadeu Degli, Exposti; Maria de Lourdes Corradi da, Silva; Eliana Gertrudes Macedo, Lemos; João Carlos, Campanharo; Joana Léa Meira, Silveira.

    Full Text Available [...] Abstract in english The exopolysaccharides with characteristics of gel produced by Rhizobium tropici (EPS RT) and Mesorhizobium sp (EPS MR) are acidic heteropolysaccharide composed mainly of glucose and galactose in a molar ratio of 4:1 and 5:1 respectively, with traces of mannose (~ 1%). Chemical analysis showed the p [...] resence of uronic acid, pyruvate and acetyl-substituents in the structures of both polymers. Experiments of gel permeation chromatography and polyacrylamide gel electrophoresis showed that EPS RT and EPS MR are homogeneous molecules with low grade of polydispersity. The EPS were characterized using spectroscopic techniques of FT-IR, ¹H and 13C-NMR.

  12. Efficacy of Various Rhizobium Strains to Different Varieties of Groundnut (Arachis hypogea L.

    Directory of Open Access Journals (Sweden)

    M. Aslam

    1999-01-01

    Full Text Available Groundnut variety BARD-699 produced significantly the most promising yield than that of variety BARI-89 at Attock, Fatehjang and NARC, Islamabad. Rhizobium strains, NC-92 was found to be less efficient as compared to TAL-1000; TAL-1371. Nodule dry mass and number of pods per plant were much higher than that of control treatment. Although a significant difference in growth and yield of both the varieties due to Rhizobium inoculation was observed but on average basis TAL-1000 and TAL-1371 gave significantly better response for both the varieties in improving growth and yield at all sites. Nevertheless, future prospects for groundnut production are good in Pakistan if the farmers are realized to practice inoculation technology in their fields.

  13. Deletion analysis of the 5' untranslated region of the Rhizobium meliloti nodF gene.

    Science.gov (United States)

    Kalinowski, G; Long, S R

    1996-12-01

    Efficient establishment of the symbiosis between rhizobia and their host plants requires precise regulation of bacterial nod genes. The nod gene transcripts in Rhizobium meliloti have approximately 200 nucleotides of untranslated sequence 5' of the start codon (5' UTR). We measured the significance of this region by constructing fusions between deletion derivatives of nodF and the reporter beta-glucuronidase (GUS). Flavonoid-inducible expression of the fusions in R. meliloti was evident when extra copies of the positive transcriptional activators NodD1, NodD3, or SyrM were present. The fusions responded normally over a range of inducer concentrations in Rhizobium leguminosarum bv. trifolii. GUS assays in planta showed no significant difference between the deletion constructs and a wild-type fusion. We conclude that the 5' UTRs of the nod gene transcripts are unlikely to have a significant regulatory role. PMID:8969536

  14. Competitiveness of Rhizobium leguminosarum bv. trifolii strains in mixed inoculation of clover (Trifolium pratense).

    Science.gov (United States)

    Wielbo, Jerzy; Marek-Kozaczuk, Monika; Kidaj, Dominika; Skorupska, Anna

    2011-01-01

    Rhizobium leguminosarum by. trifolii (Rlt) establishes beneficial root nodule symbiosis with clover. Twenty Rlt strains differentially marked with antibiotic-resistance markers were investigated in terms of their competitiveness and plant growth promotion in mixed inoculation of clover in laboratory experiments. The results showed that the studied strains essentially differed in competition ability. These differences seem not to be dependent on bacterial multiplication in the vicinity of roots, but rather on complex physiological traits that affect competitiveness. The most remarkable result of this study is that almost half of the total number of the sampled nodules was colonized by more than one strain. The data suggest that multi-strain model of nodule colonization is common in Rhizobium-legume symbiosis and reflects the diversity ofrhizobial population living in the rhizosphere. PMID:21630573

  15. Genotypic Characterisation of Indigenous Rhizobium leguminosarum bv. viciae Field Population in Croatia

    Directory of Open Access Journals (Sweden)

    Mihaela Blažinkov

    2007-06-01

    Full Text Available Genetic diversity of thirteen Rhizobium legumnosarum bv. viciae strains isolated from different field sites in continental part of Croatia was investigated. All rhizobial isolates were obtained either from plants grown in pots containing soil samples or from field grown plants. The strains were analyzed for DNA polymorphism using two DNA fingerprinting methods - randomly amplified polymorphic DNA (RAPD-PCR and repetitive extragenomic palindromic- PCR (rep-PCR. Both methods resulted in very similar grouping of strains. Cluster analysis of rep- and RAPD-PCR profi les showed significant differences among Rh. leguminosarum bv. viciae isolates. The highest differences were detected among reference strains and all field isolates revealing considerable genetic diversity of rhizobial field populations. These results suggest the presence of adapted indigenous Rhizobium leguminosarum bv. viciae strains, probably with higher competitive ability, whose symbiotic properties have to be evaluated in further investigations.

  16. Chemotaxis of Rhizobium meliloti to the plant flavone luteolin requires functional nodulation genes.

    OpenAIRE

    Caetano-anolle?s, G.; Crist-estes, D. K.; Bauer, W. D.

    1988-01-01

    Luteolin is a phenolic compound from plants that acts as a potent and specific inducer of nodABC gene expression in Rhizobium meliloti. We have found that R. meliloti RCR2011 exhibits positive chemotaxis towards luteolin. A maximum chemotactic response was observed at 10(-8) M. Two closely related flavonoids, naringenin and apigenin, were not chemoattractants. The presence of naringenin but not apigenin abolished chemotaxis of R. meliloti towards luteolin. A large deletion in the nif-nod regi...

  17. Genome sequence of the South American clover-nodulating Rhizobium leguminosarum bv. trifolii strain WSM597

    OpenAIRE

    Reeve, Wayne; Terpolilli, Jason; Melino, Vanessa; Ardley, Julie; Tian, Rui; Meyer, Sofie; Tiwari, Ravi; Yates, Ronald; O’hara, Graham; Howieson, John; Ninawi, Mohamed; Held, Brittany; Bruce, David; Detter, Chris; Tapia, Roxanne

    2013-01-01

    Rhizobium leguminosarum bv. trifolii strain WSM597 is an aerobic, motile, Gram-negative, non-spore-forming rod isolated from a root nodule of the annual clover Trifolium pallidum L. growing at Glencoe Research Station near Tacuarembó, Uruguay. This strain is generally ineffective for nitrogen (N2) fixation with clovers of Mediterranean, North American and African origin, but is effective on the South American perennial clover T. polymorphum Poir. Here we describe the features of R. leguminos...

  18. Genome sequence of the clover-nodulating Rhizobium leguminosarum bv. trifolii strain TA1

    OpenAIRE

    Reeve, Wayne; Tian, Rui; Meyer, Sofie; Melino, Vanessa; Terpolilli, Jason; Ardley, Julie; Tiwari, Ravi; Howieson, John; Yates, Ronald; O’hara, Graham; Ninawi, Mohamed; Teshima, Hazuki; Bruce, David; Detter, Chris; Tapia, Roxanne

    2013-01-01

    Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-qu...

  19. Osmoregulation in Rhizobium meliloti: Production of Glutamic Acid in Response to Osmotic Stress

    OpenAIRE

    Botsford, James L.; Lewis, Thomas A.

    1990-01-01

    Rhizobium meliloti, like many other bacteria, accumulates high levels of glutamic acid when osmotically stressed. The effect was found to be proportional to the osmolarity of the growth medium. NaCl, KCI, sucrose, and polyethylene glycol elicited this response. The intracellular levels of glutamate and K+ began to increase immediately when cells were shifted to high-osmolarity medium. Antibiotics that inhibit protein synthesis did not affect this increase in glutamate production. Cells growin...

  20. Rhizobium sp. Degradation of Legume Root Hair Cell Wall at the Site of Infection Thread Origin

    OpenAIRE

    Ridge, Robert W.; Rolfe, Barry G.

    1985-01-01

    Using a new microinoculation technique, we demonstrated that penetration of Rhizobium sp. into the host root hair cell occurs at 20 to 22 h after inoculation. It did this by dissolving the cell wall maxtrix, leaving a layer of depolymerized wall microfibrils. Colony growth pressure “stretched” the weakened wall, forming a bulge into an interfacial zone between the wall and plasmalemma. At the same time vesicular bodies, similar to plasmalemmasomes, accumulated at the penetration site in a...

  1. Rhizobium japonicum mutant strains unable to grow chemoautotrophically with H2.

    OpenAIRE

    Maier, R. J.

    1981-01-01

    Rhizobium japonicum strain SR grows chemoautotrophically on a mineral salts medium when incubated in an H2- and CO2-containing atmosphere. Mutant strains unable to grow or that grow very poorly chemoautotrophically with H2 have been isolated from strain SR. The mutant isolation procedure involved mutagenesis with ethyl methane sulfonate, penicillin selection under chemoautotrophic growth conditions, and plating of the survivors onto medium containing carbon. The resulting colonies were replic...

  2. Nodulation and Nitrogen Fixation Efficacy of Rhizobium fredii with Phaseolus vulgaris Genotypes

    OpenAIRE

    Michael J. Sadowsky; Cregan, Perry B.; Keyser, Harold H.

    1988-01-01

    Phaseolus plant introduction (PI) genotypes (consisting of 684 P. vulgaris, 26 P. acutifolius, 39 P. lunatus, and 5 P. coccineus accessions) were evaluated for their ability to form effective symbioses with strains of six slow-growing (Bradyrhizobium) and four fast-growing (Rhizobium fredii) soybean rhizobia. Of the 684 P. vulgaris genotypes examined, three PIs were found to form effective nitrogen-fixing symbioses with the R. fredii strains. While none of the Bradyrhizobium strains nodulated...

  3. Localization and partial characterization of soybean lectin-binding polysaccharide of Rhizobium japonicum.

    OpenAIRE

    Tsien, H. C.; Schmidt, E L

    1981-01-01

    Immunoelectron microscopy was combined with partial characterization of isolated exopolysaccharide to study binding of soybean lectin by Rhizobium japonicum strain USDA 138. Lectin-binding activity resided in two forms of exopolysaccharide produced during growth: an apparently very high-molecular-weight capsular form and a lower-molecular-weight diffusible form. At low-speed centrifugation, the capsular form cosedimented with cells to form a viscous, white, cell-gel complex which was not diff...

  4. Rhizobium-Legume Symbiosis and Nitrogen Fixation under Severe Conditions and in an Arid Climate

    OpenAIRE

    Zahran, Hamdi Hussein

    1999-01-01

    Biological N2 fixation represents the major source of N input in agricultural soils including those in arid regions. The major N2-fixing systems are the symbiotic systems, which can play a significant role in improving the fertility and productivity of low-N soils. The Rhizobium-legume symbioses have received most attention and have been examined extensively. The behavior of some N2-fixing systems under severe environmental conditions such as salt stress, drought stress, acidity, alkalinity, ...

  5. Análisis genómico y funcional de los sistemas de Quorum Sensing en Rhizobium leguminosarum

    OpenAIRE

    Sanchez Can?izares, Carmen

    2013-01-01

    Rhizobium leguminosarum (Rl) es una alfa-proteobacteria capaz de establecer una simbiosis diazotrófica con distintas leguminosas. A pesar de la importancia de esta simbiosis en el balance global del ciclo del nitrógeno, muy pocos genomas de rhizobios han sido secuenciados, que aporten nuevos conocimientos relacionados con las características genéticas que contribuyen a importantes procesos simbióticos. Únicamente tres secuencias completas de Rl han sido publicadas: Rl bv. viciae 3841 y ...

  6. Lectin-enhanced accumulation of manganese-limited Rhizobium leguminosarum cells on pea root hair tips.

    OpenAIRE

    Kijne, J. W.; Smit, G.; Di?az, C. L.; Lugtenberg, B. J.

    1988-01-01

    The ability of Rhizobium leguminosarum 248 to attach to developing Pisum sativum root hairs was investigated during various phases of bacterial growth in yeast extract-mannitol medium. Direct cell counting revealed that growth of the rhizobia transiently stopped three successive times during batch culture in yeast extract-mannitol medium. These interruptions of growth, as well as the simultaneous autoagglutination of the bacteria, appeared to be caused by manganese limitation. Rhizobia harves...

  7. Immunological characterization of Rhizobium leguminosarum outer membrane antigens by use of polyclonal and monoclonal antibodies.

    OpenAIRE

    Maagd, R.; Rijk, R.; Mulders, I. H.; Lugtenberg, B. J.

    1989-01-01

    Surface antigens of Rhizobium leguminosarum biovar viciae strain 248 were characterized by using polyclonal and monoclonal antibodies. With Western immunoblotting as the criterion, an antiserum raised against living whole cells recognized mainly flagellar antigens and the O-antigen-containing part of the lipopolysaccharide (LPS). Immunization of mice with a peptidoglycan-outer membrane complex yielded eight monoclonal antibodies, of which three reacted with LPS and five reacted with various s...

  8. Subcellular localization of the Rhizobium leguminosarum nodI gene product.

    OpenAIRE

    Schlaman, H. R.; Okker, R. J.; Lugtenberg, B. J.

    1990-01-01

    By the use of antibodies raised against a fusion protein of lacZ'-nodI (produced in Escherichia coli) which specifically react with NodI protein, it was shown that in wild-type Rhizobium leguminosarum biovar viciae NodI protein (i) is recovered with the cytoplasmic membrane fraction and (ii) is translated as part of the nodABCIJ operon. In addition, it was found that the bacterial chromosomal background strongly influences the expression of several nod genes.

  9. The morphogenesis of lupine root nodules during infection by Rhizobium lupini

    OpenAIRE

    W?adys?aw Golinowski; Joanna Kopci?ska; Wojciech Borucki

    1987-01-01

    The development of root nodules in Lupinus luteus infected by Rhizobium lupini was studied using cytological methods. The results obtained from examination of material sampled 6, 9, 13, 15, 20, 29 and 60 days after infection are given. The successive stages of development are described and the cytological characteristics of the tissue are presented. The mitotic divisions of the root cortex parenchyma cells, which initiated the formation of the nodule primordium, were accompanied by structural...

  10. Cloning and DNA Sequence Analysis of the Haloalkanoic Permease Uptake Gene from Rhizobium sp. RC1

    Directory of Open Access Journals (Sweden)

    S. Hamdan

    2010-01-01

    Full Text Available The aims of the study were to clone and identify the putative haloacid permease gene in Rhizobium sp. RC1. The putative dehrP gene encoding an uptake protein in Rhizobium sp. RC1 was identified by DNA sequence analysis. An approximately 3.8 kb DNA sequence upstream of dehalogenase D (dehD in plasmid pSC1 was analyzed and revealed an open reading frame of 1239 kb which encoded for 412 amino acids with calculated subunit molecular weight of 45 kDa and isoelectric point of 9.78. The amino acid sequence of DehrP gave high sequence identity of 86% with putative monochloropropionic acid permease from Agrobacterium sp. NHG3 and 62% with haloacid-specific transporter from Burkholderia cepacia MBA4. Comparison of the predicted amino acid sequence with the CD server (www.ncbi.nlm.nih.gov NCBI database also revealed the putative DehrP contained signatures of sugar transport proteins of an integral membrane protein. Therefore, a new Rhizobial dehalogenase genetic organization was proposed. However, further characterization of this transporter protein is required to fully comprehend the dehalogenase uptake system of Rhizobium sp. RC1.

  11. Regulation of Rhizobium nitrogen fixation by the unadenylylated glutamine synthetase I system.

    Science.gov (United States)

    Ludwig, R A

    1980-10-01

    Rhizobium sp. 32H1 glutamine auxotrophs have a complex phenotype: a highly adenylylated glutamine synthetase [GS; L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] I and an undetectable GS II (GS II(-)). They are defective in the adenylylation cascade system for GS I. Prototrophic revertants are of two classes: those (3204 type) which retain the adenylylated GS I phenotype but become GS II(+), and those (3205 type) which acquire a constitutive unadenylylated GS I but remain GS II(-). Like the parent auxotroph, 3204 remains incapable of nitrogen fixation both in culture and in root nodules of Macroptileum atropurpureum. In contrast, 3205 is nitrogenase constitutive. This implies that GS I or associated adenylylation proteins are involved in the control of Rhizobium 32H1 nif gene expression and that GS II is not so involved. Normally, rhizobia fix atmospheric N(2) only during symbiosis and, in so doing, only transiently synthesize nitrogenase. Moreover, whereas wild-type strains export ammonium, constitutive strains can assimilate ammonium produced by nitrogenase. This phenotype allows direct selection of nitrogen fixation-defective mutants in Rhizobium. PMID:16592892

  12. In vitro sensitivity of Rhizobium and phosphate solubilising bacteria to herbicides.

    Science.gov (United States)

    Jeenie; Sharma, Poonam; Khanna, Veena

    2011-06-01

    Nitrogen fixing bacteria, rhizobia and phosphate solubilizing bacteria (PSB) are the commonly applied microbial inoculants in grain legumes (Pulses). It is important to apply herbicides to control weeds in order to augment yield of the crop. The herbicides may however, be incompatible with the microbial inoculants. This study compared the effect of the recommended pre-plant incorporated herbicide, fluchloralin (20.25 × 10(4) ppm) and pre-emergence herbicide, pendimethalin in two doses (9 × 10(4) and 15 × 10(4) ppm) on the growth and survival of mungbean Rhizobium and PSB, under laboratory conditions. These herbicides were also used under field conditions in conjunction with biofertilizers (R, PSB) to improve grain yield of mungbean. It was found that fluchloralin (20.25 × 10(4) ppm) and the lower dose of pendimethalin (9 × 10(4) ppm) had no adverse effect on growth of Rhizobium and PSB. The higher dose of pendimethalin (15 × 10(4) ppm) was safe on PSB but it imposed a retarding effect on the growth of Rhizobium. PMID:22654170

  13. Biochemical Analysis of Chickpea Protection Against Fusarium Wilt Afforded by Two Rhizobium Isolates

    Directory of Open Access Journals (Sweden)

    A. Arfaoui

    2005-01-01

    Full Text Available Germinated seeds of two chickpea cultivars ILC482 and INRAT87/1, respectively susceptible and moderately resistant to Fusarium oxysporum f. sp. ciceris (Foc, were preinoculated with a suspension of two Rhizobium isolates PchDMS and Pch43. Three days later, the seedlings were challenged by root dip with a conidial suspension of Foc race 0. The two Rhizobium isolates protected chickpea plants from F. oxysporum infection; the best protection has been obtained by PchDMS for the two cultivars. For the susceptible cultivar, mortality was 12.5 and 33.33% for treated plants, respectively with PchDMS and Pch43 as compared to the 79.16% in the inoculated control with Foc only. For the INRAT87/1 Cv. mortality was 8.33 and 12.5% for treated plants, respectively with PchDMS and Pch43 compared to the 54.16% in the control inoculated treatment. The two Rhizobium isolates stimulated the peroxidases and polyphenoloxidases activities and induced the accumulation of phenolic compounds. The maximum of peroxidases activities in plant roots were reached 24 h after challenging. However, the higher activity of polyphenoloxidases and the higher level of the phenolic compounds were recorded 72 h after Foc inoculation. Comparing the two strains, PchDMS was more effective in inducing enzymes and phenolic compounds and highest levels were recorded in INRAT87/1 cultivar.

  14. 75 FR 9929 - United States v. Bemis Company, Inc., et al.; Proposed Final Judgment and Competitive Impact...

    Science.gov (United States)

    2010-03-04

    ...requires Bemis to divest the assets of Alcan Packaging Food...production plants and assets located in Menasha...certain other tangible and intangible assets. The proposed Final...alleges as follows: I. Nature of This Action 1....

  15. Rhizobium capsici sp. nov., isolated from root tumor of a green bell pepper (Capsicum annuum var. grossum) plant.

    Science.gov (United States)

    Lin, Shih-Yao; Hung, Mei-Hua; Hameed, Asif; Liu, You-Cheng; Hsu, Yi-Han; Wen, Cheng-Zhe; Arun, A B; Busse, Hans-Jürgen; Glaeser, Stefanie P; Kämpfer, Peter; Young, Chiu-Chung

    2015-03-01

    A novel, Gram-staining-negative, rod-shaped, aerobic and motile bacterium, designated strain CC-SKC2(T), was isolated from the root tumor of a green bell pepper (Capsicum annuum var. grossum) plant in Taiwan. Cells were positive for oxidase and catalase activities and exhibited growth at 25-37 °C, pH 4.0-9.0 and tolerated NaCl concentrations up to 4.0 % (w/v). Strain CC-SKC2(T) is able to trigger nodulation in soybean (Glycine max Merr.), but not in Capsicum annuum var. grossum, red bean (Vigna angularis), sesbania (Sesbania roxburghii Merr.) or alfalfa (Medicago varia Martin.). The novel strain shared highest 16S rRNA gene sequence similarity to Rhizobium rhizoryzae KCTC 23652(T) and Rhizobium straminoryzae CC-LY845(T) (both 97.5 %) followed by Rhizobium lemnae L6-16(T) (97.3 %), Rhizobium pseudoryzae KCTC 23294(T) (97.1 %), and Rhizobium paknamense NBRC 109338(T) (97.0 %), whereas other Rhizobium species shared <96.7 % similarity. The DNA-DNA relatedness values of strain CC-SKC2(T) with R. rhizoryzae KCTC 23652(T), R. pseudoryzae KCTC 23294(T) and R. paknamense NBRC 109338(T) were 11.4, 17.2 and 17.0 %, respectively (reciprocal values were 11.1, 28.3 and 24.0 %, respectively). Phylogenetic analysis based on 16S rRNA, atpD and recA genes revealed a distinct taxonomic position attained by strain CC-SKC2(T) with respect to other Rhizobium species. The major fatty acids in strain CC-SKC2(T) were C16:0, C19:0 cyclo ?8c, C14:0 3-OH and/or C16:1 iso I and C18:1 ?7c and/or C18:1 ?6c. The polyamine pattern showed predominance of spermidine and moderate amounts of sym-homospermidine. The predominant quinone system was ubiquinone (Q-10) and the DNA G+C content was 60.5 mol%. On the basis of polyphasic taxonomic evidence presented here, strain CC-SKC2(T) is proposed to represent a novel species within the genus Rhizobium, for which the name Rhizobium capsici sp. nov. is proposed. The type strain is CC-SKC2(T) (=BCRC 80699(T) = JCM 19535(T)). PMID:25555455

  16. Evaluation of Bean (Phaseolus vulgaris Seeds Inoculation with Rhizobium phaseoli and Plant Growth Promoting Rhizobacteria on Yield and Yield Components

    Directory of Open Access Journals (Sweden)

    M. Yadegari

    2008-01-01

    Full Text Available To study the effect of co-inoculation with plant growth-promoting rhizobacteria (PGPR and Rhizobium, on yield and yield components of common bean (Phaseolus vulgaris L. cultivars was investigated in 2 consecutive years under field condition of plant growing evidence indicates that soil beneficial bacteria can positively affect symbiotic performance of rhizobia. PGPR strains Pseudomonas fluorescens P-93 and Azospirillum lipoferum S-21 as well as two highly effective Rhizobium strains were used in this study. Common bean seeds of three cultivars were inoculated with Rhizobium singly or in a combination with PGPR to evaluate their effect on growth characters. A significant variation of plant growth in response to inoculation with Rhizobium strains was observed. Treatment with PGPR significantly increased pod per plant, number of seeds per pod, weight of 100 seed, weight of seeds per plant, weight of pods per plant, total dry matter in R6 as well as seed yield and protein content. Co-inoculation with Rhizobium and PGPR demonstrated a significant increase in the yield and yield components. The results showed that all treatments of bacteria increased yield; however, strains Rb-133 with Pseudomonas fluorescens P-93 gave the highest seed yield, number of pods per plant, weight of 100 seed, seed protein yield, number seed per pod, seed protein yield.

  17. Colonization and Nitrogenase Activity of Triticum aestivum (cv. Baccross and Mahdavi to the Dual Inoculation with Azospirillum brasilense and Rhizobium meliloti plus 2,4-D

    Directory of Open Access Journals (Sweden)

    Askary Mehry

    2008-01-01

    Full Text Available The potential enhancement of root colonization and nitrogenase activity of wheat cultivars (Baccross and Mahdavi was studied with application of two Azospirillum brasilense strains (native and Sp7 co-inoculated with two Rhizobium meliloti strains (native and DSMZ 30135. The results indicated that the colonization was different due to the strains and cultivars of wheat were used. Native A. brasilense colonized wheat root better than Sp7 strain. However, Baccross cv. reacted better with native Azospirillum compared to Mahdavi cv. which reacted better with Sp7. When plants inoculated with dual inoculants (SP7 with standard Rhizobium, the colonization of Azospirillum were increased significantly (from 1.67x105 to 22x105 cfu g-1 FW for Baccras cv. and 3.67x105 to 26x105 cfu g-1 FW for Mahdavi cultivar. When the standard Rhizobium as co-inoculants changed to the native Rhizobium, the colonization of Azospirillum was higher when compared to the single inoculants but was almost the same when compared to the standard Rhizobium. When the standard or native strains of Rhizobium used as single inoculation of wheat roots, the number of Rhizobium in the wheat roots were not changed significantly. However, when plants co-inoculated with Rhizobium and Azospirillum, the colonization of Rhizobium was increased. Co-inoculation of standard strain of R. melilot with A. brasilense Sp7 showed that the colonization of Rhizobium were increased from 0.67x105 to 21x105 cfu g-1 FW for Baccross cv. and 0.33x105 to 18x105 cfu g-1 FW for Mahdavi cv. This behavior was the same when inoculation of Rhizobium was happened with the native one. In dual inoculation, the highest nitrogenase activity was measured in combination of the local strains (native A. brasilense with the native R. meliloti and the lower one belongs to the combination of standard strains (Sp7 with standard R. meliloti. The difference in nirtogenase activity for different cultivars of wheat with Sp7 and standard Rhizobium is not significant but the difference for Sp7 strain plus native Rhizobium is significant (p>0.05. However, the differences were not significant (p<0.05 for nitrogenase activity in bacterial tubes, the difference for nitrogenase activity of co-inoculated plants with combination of Sp7 and Rhizobium either standard or native were significantly different

  18. 77 FR 36115 - Tart Cherries Grown in the States of Michigan, et al.; Final Free and Restricted Percentages for...

    Science.gov (United States)

    2012-06-18

    ...of Documents. Prices of new books are listed in the first FEDERAL...OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 930 [Doc...Cherries AGENCY: Agricultural Marketing Service, USDA. ACTION: Final...2011-12 crop year under the marketing order for tart cherries...

  19. 77 FR 44271 - United States v. Apple, Inc., et al.; Public Comments and Response on Proposed Final Judgment

    Science.gov (United States)

    2012-07-27

    ...private parties) will remain free to challenge that conduct. Finally, even if there...Judgment, and Delay Will Extend Harm B&N challenges the ``factual basis'' for a public...given the role of those agreements in cementing the terms of the conspiracy...

  20. Symbiotic effectiveness and ecological characterization of indigenous Rhizobium loti populations in Uruguay Eficiência simbiótica e caracterização ecológica de uma população nativa de Rhizobium loti no Uruguai

    Directory of Open Access Journals (Sweden)

    Amalia Baraibar

    1999-06-01

    Full Text Available The objectives of this work were to describe the distribution, density and seasonal variation of the indigenous populations of Rhizobium loti in different Uruguayan soils and to determine the symbiotic effectiveness and stress tolerance factors of different isolates, both with the aim of obtaining selected strains to re-introduce as inoculants in Lotus pastures. R. loti was present in ten soils studied and their densities varied from year to year and within each soil. All the isolates nodulated Lotus corniculatus effectively. The nodules in Lotus pedunculatus and Lotus subbiflorus were small, red on the surface and ineffective in nitrogen fixation. The study of 50 isolates from the ten soils showed high variability in their symbiotic efficiency and tolerance to pH. The indigenous population was acid tolerant in culture medium (pH 4.5, 83% of them could grow at pH 4.5 in 3 days. This work showed that there was a great diversity between the strains of R. loti isolated from Uruguayan soils and supports the importance of selecting among them the most efficient and resistant strains to be included in the inoculants.Os objetivos deste trabalho foram descrever a distribuição, densidade e variação sazonal de populações nativas de Rhizobium loti em diferentes solos uruguaios, e determinar a eficiência simbiótica e os fatores de tolerância a estresse de diversos isolados, tendo em vista a obtenção de cepas a serem reintroduzidas como inoculantes em pastagens de Lotus. Rhizobium loti estava presente em dez solos estudados, e suas densidades variavam de ano para ano e em cada solo. Todos os isolados nodularam efetivamente o Lotus corniculatus. Os nódulos no Lotus pedunculatus e no Lotus subbiflorus eram pequenos, vermelhos na superfície, e ineficazes na fixação de N. O estudo de 50 isolados dos dez solos mostraram alta variabilidade na sua eficiência simbiótica, e alta tolerância ao pH. A população nativa era tolerante à acidez em meio de cultura (pH 4,5; 83% dela pode crescer em pH 4,5 em três dias. O presente trabalho mostrou que há grande diversidade entre as cepas de R. loti isoladas de solos uruguaios, e acentua a importância de se selecionar entre elas as mais eficientes e resistentes, para serem incluídas como inoculantes.

  1. Isotopic discrimination of nitrogen associated with biological nitrogen fixation on the system Rhizobium versus beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    Two experiments were carried out in the greenhouse using a complete randomized experimental design. The first experiments was designed to assess the effect of three bean cultivars, inoculated with a mixture of efficient Rhizobium strains on the isotopic N discrimination at four development stages of beans plants. The second experiment was carried out to verify if there is any discrimination caused by the Rhizobium strains used. The plants of both experiments were grown in a N free medium, with 5 replicates. At the harvesting, ?N-15% was determined in the following parts of the bean plants: nodules, roots, shoots, cotyledons and pods. (author)

  2. Identification and Characterization of the Rhizobium sp. Strain GIN611 Glycoside Oxidoreductase Resulting in the Deglycosylation of Ginsenosides

    OpenAIRE

    Kim, Eun-Mi; Kim, Juhan; Seo, Joo-Hyun; Park, Jun-Seong; Kim, Duck-Hee; Kim, Byung-gee

    2012-01-01

    Using enrichment culture, Rhizobium sp. strain GIN611 was isolated as having activity for deglycosylation of a ginsenoside, compound K (CK). The purified heterodimeric protein complex from Rhizobium sp. GIN611 consisted of two subunits with molecular masses of 63.5 kDa and 17.5 kDa. In the genome, the coding sequence for the small subunit was located right after the sequence for the large subunit, with one nucleotide overlapping. The large subunit showed CK oxidation activity, and the deglyco...

  3. Diversity of Rhizobium-Phaseolus vulgaris symbiosis: Overview and perspectives

    International Nuclear Information System (INIS)

    Common bean (Phaseolus vulgaris) has become a cosmopolitan crop, but was originally domesticated in the Americas and has been grown in Latin America for several thousand years. Consequently an enormous diversity of bean nodulating bacteria have developed and in the centers of origin the predominant species in bean nodules is R. etli. In some areas of Latin America, inoculation, which normally promotes nodulation and nitrogen fixation is hampered by the prevalence of native strains. Many other species in addition to R. etli have been found in bean nodules in regions where bean has been introduced. Some of these species such as R. leguminosarum bv. phaseoli, R. gallicum bv. phaseoli and R. giardinii bv. phaseoli might have arisen by acquiring the phaseoli plasmid from R. etli. Others, like R. trap id, are well adapted to acid soils and high temperatures and are good inoculants for bean under these conditions. The large number of rhizobia species capable of nodulating bean supports that bean is a promiscuous host and a diversity of bean-rhizobia interactions exists. Large ranges of dinitrogen fixing capabilities have been documented among bean cultivars and commercial beans have the lowest values among legume crops. Knowledge on bean symbiosis is still incipient but could help to improve bean biological nitrogen fixation. (author)

  4. Inoculant Production with Diluted Liquid Cultures of Rhizobium spp. and Autoclaved Peat: Evaluation of Diluents, Rhizobium spp., Peats, Sterility Requirements, Storage, and Plant Effectiveness.

    Science.gov (United States)

    Somasegaran, P

    1985-08-01

    Fully grown broth cultures of various fast- and slow-growing rhizobia were deliberately diluted with various diluents before their aseptic incorporation into autoclaved peat in polypropylene bags (aseptic method) or mixed with the peat autoclaved in trays (tray method). In a factorial experiment with the aseptic method, autoclaved and irradiated peat samples from five countries were used to prepare inoculants with water-diluted cultures of three Rhizobium spp. When distilled water was used as the diluent, the multiplication and survival of rhizobia in the peat was similar to that with diluents having a high nutrient status when the aseptic method was used. In the factorial experiment, the mean viable counts per gram of inoculant were log 9.23 (strain TAL 102) > log 8.92 (strain TAL 82) > log 7.89 (strain TAL 182) after 24 weeks of storage at 28 degrees C. The peat from Argentina was the most superior for the three Rhizobium spp., with a mean viable count of log 9.0 per g at the end of the storage period. The quality of inoculants produced with diluted cultures was significantly (P = 0.05) better with irradiated than with autoclaved peat, as shown from the factorial experiment. With the tray method, rhizobia in cultures diluted 1,000-fold or less multiplied and stored satisfactorily in the presence of postinoculation contaminants, as determined by plate counts, membrane filter immunofluorescence, and plant infection procedures. All strains of rhizobia used in both the methods showed various degrees of population decline in the inoculants when stored at 28 degrees C. Fast- and slow-growing rhizobia in matured inoculants produced by the two methods showed significant (P strains increased significantly (P < 0.01) at the same temperature. The plant effectiveness of inoculants produced with diluted cultures and autoclaved peat did not differ significantly from that of inoculants produced with undiluted cultures and gamma-irradiated peat. PMID:16346860

  5. Associação de Rhizobium sp. a duas leguminosas na tolerância à atrazina / Association of Rhizobium sp. with two legumes on atrazine tolerance

    Scientific Electronic Library Online (English)

    Danielle, Camargo; Kelly Lopes, Bispo; Luciane, Sene.

    2011-08-01

    Full Text Available A associação de bactérias a plantas tem sido estudada como uma possível tecnologia emergente, para fitorremediação de contaminantes, entre eles os herbicidas, que, por sua recalcitrância, ameaçam a qualidade do ambiente. O objetivo deste trabalho foi verificar a tolerância de mucuna-anã (Stizolobium [...] deeringianum Bort) e mucuna-preta (Stizolobium aterrimum Piper & Tracy), inoculadas e não inoculadas com Rhizobium sp., ao herbicida atrazina. Os tratamentos foram: plantas com inoculante + 0,1 g/m², 0,2 g/m² atrazina e sem atrazina (T1, T2 e T3, respectivamente), sem inoculante + 0,1 g/m², 0,2 g/m² atrazina e sem atrazina (T4, T5 e T6, respectivamente). O delineamento experimental utilizado foi inteiramente casualizado, com três repetições. Foram avaliados germinação, sobrevivência, número de nódulos, altura, biomassa verde, biomassa seca da parte aérea, após o crescimento das plantas por 50 dias em casa de vegetação. Nos tratamentos com inoculante, avaliou-se a porcentagem de germinação de plantas bioindicadoras (Bidens pilosa L.). Mucuna-preta e mucuna-anã demonstraram maior tolerância ao herbicida quando associadas ao Rhizobium. Os valores de sobrevivência de mucuna-preta, nas doses 0,1 e 0,2 g/m² de atrazina (T1 e T2), foram de 34 a 24% superiores aos observados nas mesmas doses, mas sem o inoculante (T4 e T5). Para mucuna-anã, T1 e T2 foram de 17 e 8% superiores a T4 e T5, respectivamente. As alturas médias de mucuna-anã em T1, T2 e T3 foram mais elevadas que em T4, T5 e T6, reforçando a importância do simbionte à resistência ao herbicida. Os resultados encontrados para as variáveis altura, biomassa verde e seca para mucuna-preta não apresentaram diferença estatística entre os tratamentos com e sem inoculante, mostrando uma resistência natural à atrazina e a possibilidade de atuar como planta remediadora. A germinação de B. pilosa indica uma possível degradação da atrazina no solo com ambas as espécies de mucunas inoculadas com Rhizobium sp. Abstract in english The association of bacteria with plants has been studied as a possible emerging technology for phytoremediation of contaminants, including herbicides, which pose as a threatening to environmental quality due to their recalcitrance. The aim of this study was to assess the tolerance of dwarf mucuna (S [...] tizolobium deeringianum Bort) and black mucuna (Stizolobium aterrimum Piper & Tracy) inoculated and uninoculated with Rhizobium to the herbicide atrazine. The treatments were: plants with inoculant + 0.1 g/m², 0.2 g/m² atrazine, and without atrazine (T1, T2 and T3, respectively), plants without inoculant + 0.1 g/m², 0.2 g/m² atrazine and without atrazine (T4, T5 and T6, respectively). The experiment was arranged in a completely randomized design, with three replications. Plants were grown in a greenhouse for 50 days and the variables germination, survival, number of nodules, height, green/dry biomass of the aerial part were evaluated. In the treatments with inoculants, the germination percentage of bioindicator plants (Bidens pilosa L.) was also evaluated. Black mucuna and dwarf mucuna showed greater tolerance to the herbicide when associated with Rhizobium. The survival rates of black mucuna at the doses 0.1 and 0.2 g/m² atrazine (T1 and T2) were 34 and 24% higher than those observed at the same doses, but without the inoculant (T4 and T5). For dwarf mucuna, T1 and T2 were 17 and 8% higher than T4 and T5, respectively. The average heights of dwarf mucuna in T1, T2 and T3 were higher than in T4, T5 and T6, reinforcing the importance of the symbiont to the herbicide resistance. The results found for the variables height, green and dry biomass for black mucuna were not significantly different among the treatments with and without inoculant, showing a natural resistance to atrazine and the possibility of acting as a remediation plant. The germination of B. pilosa indicates a possible degradation of atrazine in the soil by both mucuna species inoculated with Rhizobium sp.

  6. Maintenance of Intracellular pH and Acid Tolerance in Rhizobium meliloti

    OpenAIRE

    O Hara, Graham W.; Goss, Thomas J.; Dilworth, Michael J.; Glenn, Andrew R.

    1989-01-01

    The development and function of the Rhizobium meliloti-Medicago sp. symbiosis are sensitive to soil acidity. Physiological criteria that can be measured in culture which serve to predict acid tolerance in soil would be valuable. The intracellular pH of R. meliloti was measured using either radioactively labeled weak acids (5,5-dimethyloxazolidine-2,4-dione and butyric acid) or pH-sensitive fluorescent compounds; both methods gave similar values. Six acid-tolerant strains (WSM419, WSM533, WSM5...

  7. Activation of Klebsiella pneumoniae and Rhizobium meliloti nitrogenase promoters by gln (ntr) regulatory proteins.

    OpenAIRE

    Sundaresan, V.; Ow, D W; Ausubel, F.M.

    1983-01-01

    We have studied the expression, in different Escherichia coli gln (ntr) mutants, of fusions (constructed in vitro) of the nifHDK (nitrogenase) promoters from Klebsiella pneumoniae and Rhizobium meliloti to E. coli lacZ. Derepression of the K. pneumoniae nifH::lacZ fusion requires the glnF (ntrA) gene product in addition to the K. pneumoniae nifA gene product, indicating that regulation of the K. pneumoniae nif genes is more closely integrated with the overall nitrogen control system than prev...

  8. Characterization of the lipopolysaccharide from a Rhizobium phaseoli mutant that is defective in infection thread development.

    OpenAIRE

    Carlson, R. W.; Kalembasa, S.; Turowski, D.; Pachori, P.; Noel, K. D.

    1987-01-01

    The lipopolysaccharide (LPS) from a Rhizobium phaseoli mutant, CE109, was isolated and compared with that of its wild-type parent, CE3. A previous report has shown that the mutant is defective in infection thread development, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that it has an altered LPS (K. D. Noel, K. A. VandenBosch, and B. Kulpaca, J. Bacteriol. 168:1392-1462, 1986). Mild acid hydrolysis of the CE3 LPS released a polysaccharide and an oligosaccharide, PS1 an...

  9. Influence of Phosphate on the Growth and Nodulation Characteristics of Rhizobium trifolii†

    OpenAIRE

    Leung, Kamtin; Bottomley, Peter J

    1987-01-01

    The growth and nodulating characteristics of Rhizobium trifolii 6 and 36 differed under different external phosphate conditions. Under growth conditions designed to deplete the internal phosphate content of the rhizobia, strain 6 maintained a generation time of 5 h during the exponential phase over two cycles of growth in phosphate-depleted medium. In contrast, the generation time of strain 36 was extended from 3.5 to 9.8 h over two cycles of phosphate-depleted growth, although the organism e...

  10. Genome sequence of the Trifolium rueppellianum -nodulating Rhizobium leguminosarum bv. trifolii strain WSM2012.

    OpenAIRE

    Reeve, Wayne; Melino, Vanessa; Ardley, Julie; Tian, Rui; Meyer, Sofie; Terpolilli, Jason; Tiwari, Ravi; Yates, Ronald; O’hara, Graham; Howieson, John; Ninawi, Mohamed; Held, Brittany; Bruce, David; Detter, Chris; Tapia, Roxanne

    2013-01-01

    Rhizobium leguminosarum bv. trifolii WSM2012 (syn. MAR1468) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an ineffective root nodule recovered from the roots of the annual clover Trifolium rueppellianum Fresen growing in Ethiopia. WSM2012 has a narrow, specialized host range for N2-fixation. Here we describe the features of R. leguminosarum bv. trifolii strain WSM2012, together with genome sequence information and annotation. The 7,180,565 bp high-quality-...

  11. Physiological distinctions of pea symbiotic mutants with various nodulation level under inoculation by Rhizobium leguminosarum

    Directory of Open Access Journals (Sweden)

    Akimova G. P.

    2012-11-01

    Full Text Available The study was focused on morphological and physiological peculiarities of pea plants with various nodulation ability under the infection by Rhizobium leguminosarum. Microscopic studies identified distinct features in formation of root nodules in different pea mutants. We revealed differences in the content of indole-acetic acid (IAA in mutants in the root zones differing by sensibility to R. leguminosarum. It was concluded that hormonal system of plants plays an important role in control of nodulation process, and emergence of mutations inducing disturbance of nodule-forming ability apparently depends on root hormonal status, in particular, IAA concentration ensuring both formation of nodule meristem and further organogenesis of the nodule.

  12. Accumulation of alpha,alpha-trehalose by Rhizobium bacteria and bacteroids.

    OpenAIRE

    Streeter, J. G.

    1985-01-01

    Four strains of Rhizobium japonicum (61A76 and USDA 110, 123, and 138) were grown in eight different defined media. Regardless of the carbon or nitrogen source supplied, alpha, alpha-trehalose was the major carbohydrate (among mono- and disaccharides) accumulated by all four strains. After 7 to 9 days of growth, trehalose generally accounted for 90 to 100% of the mono- and disaccharides detected. None of the four strains would grow with trehalose as a carbon source, but the utilization of end...

  13. Regulation of Rhizobium nitrogen fixation by the unadenylylated glutamine synthetase I system

    OpenAIRE

    Ludwig, Robert A.

    1980-01-01

    Rhizobium sp. 32H1 glutamine auxotrophs have a complex phenotype: a highly adenylylated glutamine synthetase [GS; L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] I and an undetectable GS II (GS II-). They are defective in the adenylylation cascade system for GS I. Prototrophic revertants are of two classes: those (3204 type) which retain the adenylylated GS I phenotype but become GS II+, and those (3205 type) which acquire a constitutive unadenylylated GS I but remain GS II-. Like the p...

  14. CONFIRMING LOCATION OF NITROGEN FIXING GENES ON PLASMIDS IN RHIZOBIUM ISOLATED FROM PISUM SATIVUM

    Directory of Open Access Journals (Sweden)

    Balaji Hajare and Avinash Ade1

    2012-06-01

    Full Text Available To confirm the location of the nitrogen fixing genes whether on the plasmids or on the genomic DNA the Rhizobial isolates isolated from pea (Pisum sativum were treated with acridine orange with various concentrations and fixed nitrogen was estimated from the media in which these rhizobia were grown. There was no significant difference in between the cured and non cured strains of the Rhizobium which proved that the nitrogen fixing genes are not plasmid borne but these are located on the genomic DNA.

  15. Effect of Sym Plasmid Curing on Symbiotic Effectiveness in Rhizobium fredii†

    OpenAIRE

    Mathis, James N.; Barbour, W. Mark; Elkan, Gerald H.

    1985-01-01

    A mutant, USDA 206C, of Rhizobium fredii USDA 206 was obtained by passage on acridine plates. This mutant was cured of its 197-megadalton Sym plasmid but retained its symbiotic effectiveness. Multiple plasmid and chromosomally borne nif gene copies have previously been shown in R. fredii USDA 206. HindIII and EcoRI restriction enzyme digests of plasmid and total DNA showed that at least two nif gene copies are probably missing in USDA 206C. To compare the symbiotic effectiveness of USDA 206 a...

  16. Studies on the Inoculation and Competitiveness of a Rhizobium leguminosarum Strain in Soils Containing Indigenous Rhizobia

    OpenAIRE

    Meade, James; Higgins, Patrick; O'Gara, Fergal

    1985-01-01

    The competitiveness of a Rhizobium leguminosarum strain was investigated at two separate locations in field inoculation studies on commercially grown peas. The soil at each location (sites I and II) contained an indigenous R. leguminosarum population of ca. 3 × 104 rhizobia per g of soil. At site I it was necessary to use an inoculum concentration as large as 4 × 107 CFU ml?1 (2 × 106 bacteria seed?1) to establish the inoculum strain in the majority of nodules (73%). However, at site I...

  17. Electron transport components involved in hydrogen oxidation in free-living Rhizobium japonicum.

    OpenAIRE

    O'Brian, M R; Maier, R J

    1982-01-01

    Membranes from free-living Rhizobium japonicum were isolated to study electron transport components involved in H2 oxidation. The H2/O2 uptake rate ratio in membranes was approximately 2. The electron transport inhibitors antimycin A, cyanide, azide, hydroxylamine, and 2-n-heptyl-4-hydroxyquinoline-N-oxide (HQNO) inhibited H2 uptake and H2-dependent O2 uptake significantly. H2-reduced minus O2-oxidized absorption difference spectra revealed peaks at 551.5, 560, and 603 nm, indicating the invo...

  18. Involvement of cytochromes and a flavoprotein in hydrogen oxidation in Rhizobium japonicum bacteroids.

    OpenAIRE

    O'Brian, M R; Maier, R J

    1983-01-01

    Electron transport components involved in H2 oxidation were studied in membranes from Rhizobium japonicum bacteroids. Hydrogen oxidation in membranes was inhibited by antimycin A and 2-n-heptyl-4-hydroxyquinoline-N-oxide with Ki values of 39.4 and 5.6 microM, respectively. The inhibition of H2 uptake by cyanide was triphasic with Ki values of 0.8, 9.9, and 93.6 microM. This result suggested that three cyanide-reactive components were involved in H2 oxidation. H2-reduced minus O2-oxidized abso...

  19. Tight linkage of ginA and a putative regulatory gene in Rhizobium leguminosarum

    OpenAIRE

    Colonna-romano, S.; Riccio, A.; Guida, M.; Defez, R.; Lamberti, A.; Iaccarino, M.; Arnold, Walter; Priefer, Ursula B.; Pu?hler, Alfred

    1987-01-01

    Rhizobium leguminosarum, biovar viceae, strain RCC1001 contains two glutamine synthetase activities, GSI and GSII. We report here the identification of glnA, the structural gene for GSI. A 2 kb fragment of DNA was shown to complement the Gln- phenotype of Klebsiella pneumoniae glnA mutant strains. DNA sequence analysis revealed an open reading frame (ORF) of 469 codons specifying a polypeptide of 52,040 daltons. Its deduced amino acid sequence was found to be highly homologous to other glutam...

  20. Tight linkage of glnA and a putative regulatory gene in Rhizobium leguminosarum.

    OpenAIRE

    Colonna-romano, S.; Riccio, A.; Guida, M.; Defez, R.; Lamberti, A.; Iaccarino, M.; Arnold, W.; Priefer, U.; Pu?hler, A.

    1987-01-01

    Rhizobium leguminosarum, biovar viceae, strain RCC1001 contains two glutamine synthetase activities, GSI and GSII. We report here the identification of glnA, the structural gene for GSI. A 2 kb fragment of DNA was shown to complement the Gln- phenotype of Klebsiella pneumoniae glnA mutant strains. DNA sequence analysis revealed an open reading frame (ORF) of 469 codons specifying a polypeptide of 52,040 daltons. Its deduced amino acid sequence was found to be highly homologous to other glutam...

  1. Parallel variation in isoenzyme and nitrogen fixation markers in a Rhizobium population

    DEFF Research Database (Denmark)

    Engvild, K.C.; Jensen, E.S.

    1990-01-01

    Twenty isolates of Rhizobium leguminosarum bv. viceae were isolated at random from one field and examined for symbiotic plasmid fragment length polymorphisms and for isoenzyme patterns. The latter are most probably chromosome markers. With one exception both methods separated the isolates into the same 13 different groups. The largest group was represented 7 times according to isoenzymes and 8 times according to RFLP. This fixed non-random association of plasmid and chromosomal genotypes is consistent with a clonal population structure; it indicates limited exchange of plasmids under natural conditions. Seventeen isolates of 11 groups were highly effective and 2 isolates in one group almost ineffective.

  2. Positive and negative control of nod gene expression in Rhizobium meliloti is required for optimal nodulation

    OpenAIRE

    Kondorosi, Eva; Gyuris, Jenö; Schmidt, Jürgen; John, Michael; Duda, Ernö; Hoffmann, Beate; Schell, Jeff; Kondorosi, Adam

    1989-01-01

    We show that expression of common nodulation genes in Rhizobium meliloti is under positive as well as negative control. A repressor protein was found to be involved in the negative control of nod gene expression. Whereas the activator NodD protein binds to the conserved cis-regulatory element (nod-box) required for coordinated regulation of nod genes, the repressor binds to the overlapping nodD1 and nodA promoters, at the RNA polymerase binding site. A model depicting the possible interaction...

  3. Chemical characterization of the gels produced by the diazotrophic bacteria Rhizobium tropici and Mesorhizobium sp

    International Nuclear Information System (INIS)

    The exopolysaccharides with characteristics of gel produced by Rhizobium tropici (EPSRT) and Mesorhizobium sp (EPSMR) are acidic heteropolysaccharide composed mainly of glucose and galactose in a molar ratio of 4:1 and 5:1 respectively, with traces of mannose (? 1%). Chemical analysis showed the presence of uronic acid, pyruvate and acetyl-substituents in the structures of both polymers. Experiments of gel permeation chromatography and polyacrylamide gel electrophoresis showed that EPSRT and EPSMR are homogeneous molecules with low grade of polydispersity. The EPS were characterized using spectroscopic techniques of FT-IR, 1H and 13C-NMR. (author)

  4. Correlation between extracellular fibrils and attachment of Rhizobium leguminosarum to pea root hair tips.

    OpenAIRE

    Smit, G.; Kijne, J. W.; Lugtenberg, B. J.

    1986-01-01

    As part of a project meant to characterize molecules involved in nodulation, a semiquantitative microscopic assay was developed for measuring attachment of Rhizobium leguminosarum cells to pea root hair tips, i.e., the site at which R. leguminosarum initiates nodulation. This form of attachment, designated as cap formation, was dependent on the incubation pH and growth phase, with optimal attachment at pH 7.5 and with bacteria in the early stationary phase of growth. Addition of glucose to th...

  5. Suppression of nodulation gene expression in bacteroids of Rhizobium leguminosarum biovar viciae.

    OpenAIRE

    Schlaman, H. R.; Horvath, B.; Vijgenboom, E.; Okker, R. J.; Lugtenberg, B. J.

    1991-01-01

    The expression of nod genes of Rhizobium leguminosarum bv. viciae in nodules of Pisum sativum was investigated at both the translational and transcriptional levels. By using immunoblots, it was found that the levels of NodA, NodI, NodE, and NodO proteins were reduced at least 14-fold in bacteriods compared with cultured cells, whereas NodD protein was reduced only 3-fold. Northern (RNA) blot hybridization, RNase protection assays, and in situ RNA hybridization together showed that, except for...

  6. Subcellular localization of the nodD gene product in Rhizobium leguminosarum.

    OpenAIRE

    Schlaman, H. R.; Spaink, H. P.; Okker, R. J.; Lugtenberg, B. J.

    1989-01-01

    In Rhizobium strains the transcription of symbiosis plasmid-localized nod genes, except nodD, is induced by plant flavonoids and requires the nodD gene product. In order to localize NodD protein in R. leguminosarum, a NodD protein-specific antiserum was raised against a lacZ'-'nodD gene fusion product. Using these antibodies, we determined that the NodD protein is located exclusively in the cytoplasmic membrane of wild-type R. leguminosarum biovar viciae cells. This localization is independen...

  7. Genetic analysis and cellular localization of the Rhizobium host specificity-determining NodE protein.

    OpenAIRE

    Spaink, H. P.; Weinman, J.; Djordjevic, M. A.; Wijffelman, C. A.; Okker, R. J.; Lugtenberg, B. J.

    1989-01-01

    The nucleotide sequence of the nodE gene of Rhizobium trifolii strain ANU843 was determined. Like the nodE gene of R. leguminosarum strain 248 it encodes a protein with a predicted mol. wt of 42.0 kd. The predicted NodE proteins of R.trifolii and R.leguminosarum have a homology of 78%. Using antibodies raised against the NodE protein of R.trifolii it was shown that the NodE products of R.leguminosarum and R.trifolii are localized in the cytoplasmic membrane. Furthermore, these NodE proteins a...

  8. Isolation and characterization of ropA homologous genes from Rhizobium leguminosarum biovars viciae and trifolii.

    OpenAIRE

    Roest, H. P.; Bloemendaal, C. J.; Wijffelman, C. A.; Lugtenberg, B. J.

    1995-01-01

    ropA encodes a 36-kDa outer membrane protein of Rhizobium leguminosarum bv. viciae strain 248 which constitutes the low-M(r) part of antigen group III (R.A. de Maagd, I.H.M. Mulders, H.C.J. Canter Cremers, B.J.J. Lugtenberg, J. Bacteriol. 174:214-221, 1992). We observed that genes homologous to ropA are present in strain 248 as well as in other R. leguminosarum strains, and we describe the cloning and characterization of two of these genes. Sequencing of a 2.2-kb Bg/II fragment from R. legumi...

  9. Rhizobium meliloti produces a family of sulfated lipooligosaccharides exhibiting different degrees of plant host specificity.

    OpenAIRE

    Schultze, M.; Quiclet-sire, B.; Kondorosi, E.; Virelizer, H.; Glushka, J. N.; Endre, G.; Ge?ro, S. D.; Kondorosi, A.

    1992-01-01

    We have shown that a Rhizobium meliloti strain overexpressing nodulation genes excreted high amounts of a family of N-acylated and 6-O-sulfated N-acetyl-beta-1,4-D-glucosamine penta-, tetra-, and trisaccharide Nod factors. Either a C(16:2) or a C(16:3) acyl chain is attached to the nonreducing end subunit, whereas the sulfate group is bound to the reducing glucosamine. One of the tetrasaccharides is identical to the previously described NodRm-1 factor. The two pentasaccharides as well as NodR...

  10. A Monocarboxylate Permease of Rhizobium leguminosarum Is the First Member of a New Subfamily of Transporters

    OpenAIRE

    Hosie, A. H. F.; Allaway, D.; Poole, P. S.

    2002-01-01

    Amino acid transport by Rhizobium leguminosarum is dominated by two ABC transporters, the general amino acid permease (Aap) and the branched-chain amino acid permease (Bra). However, mutation of these transporters does not prevent this organism from utilizing alanine for growth. An R. leguminosarum permease (MctP) has been identified which is required for optimal growth on alanine as a sole carbon and nitrogen source. Characterization of MctP confirmed that it transports alanine (Km = 0.56 mM...

  11. Production of Rhizobium Inoculants for Lupinus nootkatensis on Nutrient-Supplemented Pumice

    OpenAIRE

    Einarsson, Sigurbjorn; Gudmundsson, Jon; Sverrisson, Halldor; Kristjansson, Jakob K.; Runolfsson, Sveinn

    1993-01-01

    The use of the legume Lupinus nootkatensis as a pioneer plant to fight soil erosion and to reclaim eroded soils in Iceland has been under development for a few years. Production of a robust, low-cost bacterial inoculant was therefore a prerequisite for the extended use of this plant. Volcanic pumice is a naturally expanded mineral which is available in vast amounts in Iceland. It was tested as a carrier for solid fermentation of Rhizobium lupini. Nutrient-supplemented pumice containing a smal...

  12. Electrochemical assay of the nitrate and nitrite reductase activities of Rhizobium japonicum.

    Science.gov (United States)

    Salome, J Priscilla; Amutha, R; Jagannathan, P; Josiah, J J M; Berchmans, Sheela; Yegnaraman, V

    2009-08-15

    This work describes an electrochemical method for the determination of the nitrate and nitrite reductase activities of Rhizobium japonicum. The advantage of the method lies in the use of whole cells for the analysis and we earlier developed this protocol for the assay of NO. The results obtained are comparable to the spectrophotometric Griess assay. As the method is based on electrochemical reduction, the commonly interfering biological components like ascorbic acid, uric acid, dopamine, etc., will not interfere with the analysis. This method can be extended to the fabrication of biosensors for nitrate and nitrite using the same principle. PMID:19482466

  13. The impact of the EU ETS on electricity prices. Final report to DG Environment of the European Commission

    International Nuclear Information System (INIS)

    On February 2, 2009, a revised edition of the report has been released, including some adjustments and editorial corrections particularly in Section 2.2 and Appendix A. The present study analyses the impact of the EU Emissions Trading Scheme (ETS) on electricity prices, in particular on wholesale power markets across the EU. To study this impact, a variety of methodological approaches is used, including theoretical, empirical, model, literature and policy analyses. The study shows that a significant part of the costs of freely allocated CO2 emission allowances is passed through to power prices, resulting in higher electricity prices for consumers and additional ('windfall') profits for power producers. In addition, it discusses some policy implications of the pass-through of these costs. It concludes that the pass-through of CO2 costs to electricity prices is a rational, carbon-efficient policy, while the issue of windfall profits can be addressed by either taxing these profits or auctioning - rather than free allocations - of the emission allowances

  14. Draft Genome Sequence of Rhizobium sp. H41, a Rock-Weathering Bacterium from a Weathered Rock Surface

    OpenAIRE

    Xi, Jun; Sheng, Xiafang; He, Linyan

    2014-01-01

    Rhizobium sp. H41 isolated from weathered tuff can weather tuff and release Fe, Si, and Al from the rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain H41, which may facilitate a better understanding of the molecular mechanism involved in rock weathering by the bacterium.

  15. Serine residue 45 of nodulation protein NodF from Rhizobium leguminosarum bv. viciae is essential for its biological function.

    OpenAIRE

    Ritsema, T.; Geiger, O.; Dillewijn, P.; Lugtenberg, B. J.; Spaink, H. P.

    1994-01-01

    A system for testing the role of the Rhizobium nodF gene in the production of host-specific lipochitin oligosaccharides and in nodulation was developed. We show that a mutant nodF gene, in which the codon for serine residue 45 was changed to that for threonine, still expresses NodF, which, however, is no longer functional.

  16. Multilocus Sequence-Based Analysis Delineates a Clonal Population of Agrobacterium (Rhizobium) radiobacter (Agrobacterium tumefaciens) of Human Origin ?

    OpenAIRE

    Aujoulat, Fabien; Jumas-bilak, Estelle; Masnou, Agne?s; Salle?, Fanny; Faure, Denis; Segonds, Christine; Marchandin, He?le?ne; Teyssier, Corinne

    2011-01-01

    The genus Agrobacterium includes plant-associated bacteria and opportunistic human pathogens. Taxonomy and nomenclature within the genus remain controversial. In particular, isolates of human origin were all affiliated with the species Agrobacterium (Rhizobium) radiobacter, while phytopathogenic strains were designated under the synonym denomination Agrobacterium tumefaciens. In order to study the relative distribution of Agrobacterium strains according to their origins, we performed a multil...

  17. Effectiveness and competing capacity of native Rhizobium strains evaluated in IX Region soils

    International Nuclear Information System (INIS)

    Symbiotic nitrogen fixation in legumes reaches its optimum when the host plants are nodulated by highly competitive and effective Rhizobium strains. With the purpose of assessing competition and nitrogen fixing capacity of native Rhizobium leguminosarum bio-var trifolii strains, a greenhouse test was carried out using white clover (Trifolium re-pens) and four kinds of soils, which represent the main agroecological areas of the IX Region. Eleven strains were evaluated, they were both native and collected and were streptomycin sulphate antibiotic resistant. A nitrogen and a nitrogen-less without inoculation testers were used as controls. All pots received a solution of ammonium sulphate marked with 10% 15 N a.e, equivalent to 10 kg ha-1 of N. Rye-grass was used as reference crop, cv. Nu-i. In general, the evaluated strains were very efficient. After three or four cuts they became the only source of nitrogen for the plants. They were also very competitive, getting to over 70% of root infection with regard to those present in soils. In Curacautin and Tolten soils, biological nitrogen fixation begins later than other soils evaluated, which is coincident with soils having a higher nitrogen content. Symbiosis occurs when the soil nitrogen content exhausts or diminishes. (author)

  18. Studies on Nodulation, Biochemical Analysis and Protein Profiles of Rhizobium Isolated From Indigofera species

    Directory of Open Access Journals (Sweden)

    Kumari, B. S.

    2010-01-01

    Full Text Available Nodulation characteristics in five species of Indigofera viz., I .trita, I. linnaei, I. astragalina, I. parviflora and I. viscosa was studied at regular intervals on the plants raised in garden soil. Among the species studied, highest average number of nodules per plant of 23 with maximum sized nodules of 8.0 mm diameter was observed in I. astragalina. Biochemical analysis of root nodules of I. astragalina revealed that the leghaemoglobin content of nodules and nitrogen content of root, shoot, leaves and nodules were gradually increased up to 60 DAS, and then decreased with increase in age. Rhizobium isolates of five species of Indigofera were isolated and screened for enzymatic activities and total cellular protein profiles. All the five isolates showed nitrate reductase, citrase, tryptophanase and catalase activity while much variation was observed for enzymes like gelatinase, urease, caseinase, lipase, amylase, lysine decarboxylase and protease activities. Among the isolates studied, only the isolate from I. viscosa has the ability to solubilize the insoluble tricalcium phosphate. All the Rhizobium isolates exhibit similarity in protein content, except the isolate from I. viscosa which showed one additional protein band.

  19. Variability of isolated colonies in bean nodulating Rhizobium strains before and after exposure to high temperature

    Directory of Open Access Journals (Sweden)

    Raposeiras Rui

    2002-01-01

    Full Text Available Irregular response to bean plants to Rhizobium inoculation has been attributed to among other factors, low competitive ability, low N2 fixation efficiency and genetic instability of the symbiont. This genetic instability caused by high rates of genomic rearrangements and/or plasmid deletions can be accentuated by high temperatures. This fact may limit the utilization of these strains as inoculants, especially in tropical soils. In this study, the variability of isolated colonies derived from effective R. leguminosarum bv. phaseoli (SLP1.3 and BR 10.026 and R tropici (SLA2.2 and BR322 strains was evaluated before and after exposure to high temperatures (four consecutive thermal shocks at 45masculineC. This evaluation involved plant dry matter analysis of inoculated plants and genotypic (plasmid profile and genomic patterns via RAPD analysis of the Rhizobium strains. The results evidenced that high temperature improve the natural performance variability especially between isolated colonies from R. leguminosarum bv. phaseoli strains. The plasmid profile of isolated colonies from R. tropici strains were identical regardless of temperature treatment whereas isolated colonies from R. leguminosarum bv. phaseoli alterations were detected especially after the thermal treatment. The genomic patterns generated by AP-PCR showed more alterations and genetic variation in isolated colonies from R. leguminosarum bv. phaseoli strains indicating that R. tropici strains are more stable and lower affected by high temperature.

  20. Revegetating fly ash landfills with Prosopis juliflora L.: impact of different amendments and Rhizobium inoculation.

    Science.gov (United States)

    Rai, U N; Pandey, K; Sinha, S; Singh, A; Saxena, R; Gupta, D K

    2004-05-01

    A revegetation trial was conducted to evaluate the feasibility of growing a legume species, Prosopis juliflora L., on fly ash ameliorated with combination of various organic amendments, blue-green algal biofertilizer and Rhizobium inoculation. Significant enhancements in plant biomass, photosynthetic pigments, protein content and in vivo nitrate reductase activity were found in the plants grown on ameliorated fly ash in comparison to the plants growing in unamended fly ash or garden soil. Higher growth was obtained in fly ash amended with blue-green algae (BGA) than farmyard manure or press mud (PM), a waste from sugar-processing industry, due to the greater contribution of plant nutrients, supply of fixed nitrogen and increased availability of phosphorus. Nodulation was suppressed in different amendments of fly ash with soil in a concentration-duration-dependent manner, but not with other amendments. Plants accumulated higher amounts of Fe, Mn, Cu, Zn and Cr in various fly ash amendments than in garden soil. Further, inoculation of the plant with a fly ash tolerant Rhizobium strain conferred tolerance for the plant to grow under fly ash stress conditions with more translocation of metals to the above ground parts. The results showed the potential of P. juliflora to grow in plantations on fly ash landfills and to reduce the metal contents of fly ash by bioaccumulation in its tissues. PMID:14987858

  1. A novel polar surface polysaccharide from Rhizobium leguminosarum binds host plant lectin.

    Science.gov (United States)

    Laus, Marc C; Logman, Trudy J; Lamers, Gerda E; Van Brussel, Anton A N; Carlson, Russell W; Kijne, Jan W

    2006-03-01

    Rhizobium bacteria produce different surface polysaccharides which are either secreted in the growth medium or contribute to a capsule surrounding the cell. Here, we describe isolation and partial characterization of a novel high molecular weight surface polysaccharide from a strain of Rhizobium leguminosarum that nodulates Pisum sativum (pea) and Vicia sativa (vetch) roots. Carbohydrate analysis showed that the polysaccharide consists for 95% of mannose and glucose, with minor amounts of galactose and rhamnose. Lectin precipitation analysis revealed high binding affinity of pea and vetch lectin for this polysaccharide, in contrast to the other known capsular and extracellular polysaccharides of this strain. Expression of the polysaccharide was independent of the presence of a Sym plasmid or the nod gene inducer naringenin. Incubation of R. leguminosarum with labelled pea lectin showed that this polysaccharide is exclusively localized on one of the poles of the bacterial cell. Vetch roots incubated with rhizobia and labelled pea lectin revealed that this bacterial pole is involved in attachment to the root surface. A mutant strain deficient in the production of this polysaccharide was impaired in attachment and root hair infection under slightly acidic conditions, in contrast to the situation at slightly alkaline conditions. Our data are consistent with the hypothesis that rhizobia can use (at least) two mechanisms for docking at the root surface, with use of a lectin-glycan mechanism under slightly acidic conditions. PMID:16553877

  2. Industrial wastewater as raw material for exopolysaccharide production by Rhizobium leguminosarum

    Scientific Electronic Library Online (English)

    Mohamed, Sellami; Tomasz, Oszako; Nabil, Miled; Faouzi, Ben Rebah.

    2015-06-01

    Full Text Available The objective of this study was to evaluate the exopolysaccharide (EPS) production by Rhizobium leguminosarum cultivated in wastewater generated by oil companies (WWOC1 and WWOC2) and fish processing industry (WWFP). The results obtained in Erlenmeyer flasks indicated that the rhizobial strain grew [...] well in industrial wastewater. Generally, wastewater composition affected the growth and the EPS production. WWFP allowed good bacterial growth similar to that obtained with the standard medium (YMB). During growth, various quantities of EPS were produced and yields varied depending on the media. Growing in YMB, EPS production did not exceed 9.7 g/L obtained after 72 h of growth. In wastewater, the maximum EPS value reached 11.1 g/L obtained with the fish processing wastewater, after 72 h of growth. The use of a mixture of the oil company wastewater (WWOC2) and the fish processing wastewater (WWFP) as culture medium affected not only the rhizobial strain growth, but also EPS production. The highest EPS (42.4 g/L, after 96 h of culture) was obtained using a ratio of WWFP and WWOC2 of 50:50 (v:v). Therefore, this work shows the ability of Rhizobium leguminosarum, growing in industrial wastewater as new economic medium, to produce EPS. This biopolymer could be applied in enormous biotechnological areas.

  3. Role of Rhizobium endoglucanase CelC2 in cellulose biosynthesis and biofilm formation on plant roots and abiotic surfaces

    Directory of Open Access Journals (Sweden)

    Robledo M

    2012-09-01

    Full Text Available Abstract Background The synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. In this study, we analyzed both the production of cellulose by all known members of the Rhizobiaceae and the diversity of Rhizobium celABC operon predicted to be involved in cellulose biosynthesis. We also investigated the involvement in cellulose production and biofilm formation of celC gene encoding an endoglucanase (CelC2 that is required for canonical symbiotic root hair infection by Rhizobium leguminosarum bv. trifolii. Results ANU843 celC mutants lacking (ANU843?C2 or overproducing cellulase (ANU843C2+ produced greatly increased or reduced amounts of external cellulose micro fibrils, respectively. Calcofluor-stained cellulose micro fibrils were considerably longer when formed by ANU843?C2 bacteria rather than by the wild-type strain, in correlation with a significant increase in their flocculation in batch culture. In contrast, neither calcofluor-stained extracellular micro fibrils nor flocculation was detectable in ANU843C2+ cells. To clarify the role of cellulose synthesis in Rhizobium cell aggregation and attachment, we analyzed the ability of these mutants to produce biofilms on different surfaces. Alteration of wild-type CelC2 levels resulted in a reduced ability of bacteria to form biofilms both in abiotic surfaces and in planta. Conclusions Our results support a key role of the CelC2 cellulase in cellulose biosynthesis by modulating the length of the cellulose fibrils that mediate firm adhesion among Rhizobium bacteria leading to biofilm formation. Rhizobium cellulose is an essential component of the biofilm polysaccharidic matrix architecture and either an excess or a defect of this “building material” seem to collapse the biofilm structure. These results position cellulose hydrolytic enzymes as excellent anti-biofilm candidates.

  4. The effect of soil carbon on symboitic nitrogen fixation and symbiotic Rhizobium populations in soil with Trifolium repens as host plant

    OpenAIRE

    Swanepoel, Pieter Andreas; Botha, Philip R.; Truter, Wayne Frederick; Surridge-Talbot, A.K.J. (Angela Karen Joanna)

    2011-01-01

    Soil organic carbon (SOC) is the main attribute of high-quality soil. The amount of nitrogen fixed by Rhizobium symbiotically with Trifolium repens (white clover) is ultimately determined by the quality of the soil environment. The effect of SOC on the total number of symbiotic and saprophytic rhizobia was determined. Subsequently, the amount of nitrogen (N) fixed was assessed by using the N difference technique. Most Rhizobium was detected between a SOC content of 2.03% to 3.80% in ...

  5. Evaluation of Bean (Phaseolus vulgaris) Seeds Inoculation with Rhizobium phaseoli and Plant Growth Promoting Rhizobacteria on Yield and Yield Components

    OpenAIRE

    Yadegari, M.; Rahmani, H. A.; Noormohammadi, G.; Ayneband, A.

    2008-01-01

    To study the effect of co-inoculation with plant growth-promoting rhizobacteria (PGPR) and Rhizobium, on yield and yield components of common bean (Phaseolus vulgaris L.) cultivars was investigated in 2 consecutive years under field condition of plant growing evidence indicates that soil beneficial bacteria can positively affect symbiotic performance of rhizobia. PGPR strains Pseudomonas fluorescens P-93 and Azospirillum lipoferum S-21 as well as two highly effective Rhizobium strains ...

  6. A biovar-specific signal of Rhizobium leguminosarum bv. viciae induces increased nodulation gene-inducing activity in root exudate of Vicia sativa subsp. nigra.

    OpenAIRE

    Brussel, A. A.; Recourt, K.; Pees, E.; Spaink, H. P.; Tak, T.; Wijffelman, C. A.; Kijne, J. W.; Lugtenberg, B. J.

    1990-01-01

    Flavonoids in root exudate of leguminous plants activate the transcription of Rhizobium genes involved in the formation of root nodules (nod genes). We report that inoculation with the homologous symbiont R. leguminosarum bv. viciae results in an increased nod gene-inducing activity (Ini) in root exudate of V. sativa subsp. nigra, whereas inoculation with heterologous Rhizobium strains results in exudates with nod gene-inducing activity comparable to that of uninfected plants. Ini can be demo...

  7. Enhanced Survival and Nodule Occupancy of Pigeon pea Nodulating Rhizobium sp. ST1 expressing fegA Gene of Bradyrhizobium japonicum 61A152

    Directory of Open Access Journals (Sweden)

    G. Archana

    2009-01-01

    Full Text Available Problem statement: Rhizobial isolates belonging to genera (Rhizobium sp. and Mesorhizobium sp. in our laboratory produced only catecholate type of siderophores. Although FhuA and FegA (ferrichrome receptors homologs were found to be present in the sequenced genomes of few rhizobia (e.g., 1 in R. etli and 2 in Mesorhizobium sp. BNC1, laboratory isolates of the corresponding genera failed to utilize ferrichrome, a siderophore which is present in nanomolar concentrations in the soil. This inability was considered as a negative fitness factor with respect to rhizospheric colonization by these rhizobia. Approach: The 2.4 kb fegA gene (encoding ferrichrome receptor was amplified along with its native promoter from Bradyrhizobium japonicum 61A152 and cloned in a broad host range plasmid vector pUCPM18. The plasmid construct pFJ was transferred by conjugation into Rhizobium sp. ST1 to give transconjugant ST1pFJ12. The consequence of FegA expression on the transconjugant was tested under lab and soil conditions, using physiological experiments. Results: Ability of the transconjugant ST1pFJ12 to utilize ferrichrome and expression of a 79 kD protein band on the outer membrane of the transconjugant confirmed FegA expression. Transconjugant ST1pFJ12 exhibited increased growth rate as compared to the parent strain ST1, in minimal media containing ferrichrome as the sole iron source, confirming the positive effect of FegA expression. Inoculation of pigeon pea seedlings with transconjugant ST1pFJ12 led to a marked increase in plant growth parameters as compared to plants inoculated with the parent strain ST1, the effect being more pronounced when Ustilago maydis, a ferrichrome producer was co-inoculated in the systems. Nodule occupancy on pigeon pea plant when inoculated with the transconjugant ST1pFJ12 alone was 57% which increased to 66% when co-inoculated with U. maydis as compared with 37 and 30% respectively, seen with parental strain ST1 inoculation. Conclusion: The clear increase in nodule occupancy and higher rhizospheric colonization by the fegA transconjugants, presented in this study together with the previous research reported from our laboratory, led us to conclude that ferrichrome utilization ability played an important role in the rhizospheric colonization of the bioinoculant strains. Testing the ability to utilize hydroxamate siderophores therefore, holds prime importance in selecting an efficient biofertilizer strain.

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

    Scientific Electronic Library Online (English)

    Maqshoof, Ahmad; Zahir A., Zahir; Farheen, Nazli; Fareeha, Akram; Muhammad, Arshad; Muhammad, Khalid.

    1341-13-01

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

  9. Efeito residual da vinhaça na população autóctone de Rhizobium do solo Residual effects of sugar cane vinasse on indigenous Rhizobia

    Directory of Open Access Journals (Sweden)

    Eli Sidney Lopes

    1986-01-01

    Full Text Available A adição de vinhaça na cultura canavieira tem sido praticada em áreas próximas às usinas de cana. Seria de interesse a avaliação do efeito da vinhaça no Rhizobium presente no solo (autóctone, uma vez que leguminosas têm sido indicadas para cultivo intercalar com a cana. Um experimento foi conduzido em casa de vegetação, com o objetivo de verificar a influência da aplicação contínua, durante três anos, de concentrações crescentes de vinhaça (0, 100 e 1.000 m³/ha/ano, com intervalos de seis meses entre aplicações, na população autóctone de Rhizobium que nodula amendoim, soja, feijão e crotalária. Em cada cultura, foram usados controle com solo sem adição da vinhaça e um tratamento inoculado com uma estirpe de Rhizobium de conhecida eficiência, recomendada para a cultura. Uma análise do efeito de uma dose adicional de 1,5 ppm do herbicida 2,4-D no tratamento com 100 m³/ha/ano foi também efetuada. Apesar de os resultados serem variados entre as culturas, ocorreram efeitos da vinhaça sobre a população de Rhizobium, causando aumentos de nodulação na crotalária e diminuição no amendoim. Não foram observados efeitos na nodulação do feijoeiro em nenhum dos tratamentos com a vinhaça, nem na soja, que nodulou somente com a dose mais elevada, sugerindo que o Rhizobium japonicum no solo estudado estava presente em baixo número. O tratamento com herbicida mostrou tendência de favorecer a nodulação e, conseqüentemente, a fixação biológica de N2, medida através do N na planta.The addition of vinasse on sugar cane plantations nearby alcohol fermentation plants is a common practice. Legumes are recommended to be intercropped with sugar cane. A greenhouse experiment was carried out with the objective of verifying the influence of continuous application of vinasse (0; 100 and 1000 m³/ha/year at six month interval during three years on soil rhizobia which nodulate peanuts, soybeans, dry-beans and crotalaria. Controls without vinasse and with efficient Rhizobium sp. strain were maintained. The effect of 2,4 D application on the 100 m³ vinasse/ha treatment was also studied. Although results were variable and dependent on crop, the addition of vinasse influenced the rhizobia population, causing for instance, reductions on nodulation of peanuts and increases on that of crotalaria; no effects were observed either on drybeans or soybeans. Indigenous population of soybean Rhizobiun was inexpressive. The herbicide treatment showed tendency to favour nodulation and consequently N2 fixation.

  10. Efeito residual da vinhaça na população autóctone de Rhizobium do solo / Residual effects of sugar cane vinasse on indigenous Rhizobia

    Scientific Electronic Library Online (English)

    Eli Sidney, Lopes; Sonia Cristina, Perón; Edilberto Princi, Portugal; Antonio Roberto, Giardini.

    Full Text Available A adição de vinhaça na cultura canavieira tem sido praticada em áreas próximas às usinas de cana. Seria de interesse a avaliação do efeito da vinhaça no Rhizobium presente no solo (autóctone), uma vez que leguminosas têm sido indicadas para cultivo intercalar com a cana. Um experimento foi conduzido [...] em casa de vegetação, com o objetivo de verificar a influência da aplicação contínua, durante três anos, de concentrações crescentes de vinhaça (0, 100 e 1.000 m³/ha/ano), com intervalos de seis meses entre aplicações, na população autóctone de Rhizobium que nodula amendoim, soja, feijão e crotalária. Em cada cultura, foram usados controle com solo sem adição da vinhaça e um tratamento inoculado com uma estirpe de Rhizobium de conhecida eficiência, recomendada para a cultura. Uma análise do efeito de uma dose adicional de 1,5 ppm do herbicida 2,4-D no tratamento com 100 m³/ha/ano foi também efetuada. Apesar de os resultados serem variados entre as culturas, ocorreram efeitos da vinhaça sobre a população de Rhizobium, causando aumentos de nodulação na crotalária e diminuição no amendoim. Não foram observados efeitos na nodulação do feijoeiro em nenhum dos tratamentos com a vinhaça, nem na soja, que nodulou somente com a dose mais elevada, sugerindo que o Rhizobium japonicum no solo estudado estava presente em baixo número. O tratamento com herbicida mostrou tendência de favorecer a nodulação e, conseqüentemente, a fixação biológica de N2, medida através do N na planta. Abstract in english The addition of vinasse on sugar cane plantations nearby alcohol fermentation plants is a common practice. Legumes are recommended to be intercropped with sugar cane. A greenhouse experiment was carried out with the objective of verifying the influence of continuous application of vinasse (0; 100 an [...] d 1000 m³/ha/year) at six month interval during three years on soil rhizobia which nodulate peanuts, soybeans, dry-beans and crotalaria. Controls without vinasse and with efficient Rhizobium sp. strain were maintained. The effect of 2,4 D application on the 100 m³ vinasse/ha treatment was also studied. Although results were variable and dependent on crop, the addition of vinasse influenced the rhizobia population, causing for instance, reductions on nodulation of peanuts and increases on that of crotalaria; no effects were observed either on drybeans or soybeans. Indigenous population of soybean Rhizobiun was inexpressive. The herbicide treatment showed tendency to favour nodulation and consequently N2 fixation.

  11. Genome sequence of the Trifolium rueppellianum -nodulating Rhizobium leguminosarum bv. trifolii strain WSM2012.

    Science.gov (United States)

    Reeve, Wayne; Melino, Vanessa; Ardley, Julie; Tian, Rui; De Meyer, Sofie; Terpolilli, Jason; Tiwari, Ravi; Yates, Ronald; O’Hara, Graham; Howieson, John; Ninawi, Mohamed; Held, Brittany; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Szeto, Ernest; Ivanova, Natalia; Mikhailova, Natalia; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Woyke, Tanja; Kyrpides, Nikos

    2013-01-01

    Rhizobium leguminosarum bv. trifolii WSM2012 (syn. MAR1468) is an aerobic, motile, Gram-negative, non-spore-forming rod that was isolated from an ineffective root nodule recovered from the roots of the annual clover Trifolium rueppellianum Fresen growing in Ethiopia. WSM2012 has a narrow, specialized host range for N2-fixation. Here we describe the features of R. leguminosarum bv. trifolii strain WSM2012, together with genome sequence information and annotation. The 7,180,565 bp high-quality-draft genome is arranged into 6 scaffolds of 68 contigs, contains 7,080 protein-coding genes and 86 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. PMID:24976885

  12. Genome sequence of the clover-nodulating Rhizobium leguminosarum bv. trifolii strain TA1

    Science.gov (United States)

    Reeve, Wayne; Tian, Rui; De Meyer, Sofie; Melino, Vanessa; Terpolilli, Jason; Ardley, Julie; Tiwari, Ravi; Howieson, John; Yates, Ronald; O’Hara, Graham; Ninawi, Mohamed; Teshima, Hazuki; Bruce, David; Detter, Chris; Tapia, Roxanne; Han, Cliff; Wei, Chia-Lin; Huntemann, Marcel; Han, James; Chen, I-Min; Mavromatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Ovchinnikova, Galina; Pagani, Ioanna; Pati, Amrita; Goodwin, Lynne; Pitluck, Sam; Woyke, Tanja; Kyrpides, Nikos

    2013-01-01

    Rhizobium leguminosarum bv. trifolii strain TA1 is an aerobic, motile, Gram-negative, non-spore-forming rod that is an effective nitrogen fixing microsymbiont on the perennial clovers originating from Europe and the Mediterranean basin. TA1 however is ineffective with many annual and perennial clovers originating from Africa and America. Here we describe the features of R. leguminosarum bv. trifolii strain TA1, together with genome sequence information and annotation. The 8,618,824 bp high-quality-draft genome is arranged in a 6 scaffold of 32 contigs, contains 8,493 protein-coding genes and 83 RNA-only encoding genes, and is one of 20 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Community Sequencing Program. PMID:24976881

  13. Rhizobium-initiated rice growth inhibition caused by nitric oxide accumulation.

    Science.gov (United States)

    Perrine-Walker, Francine M; Gartner, Elena; Hocart, Charles H; Becker, Anke; Rolfe, Barry G

    2007-03-01

    Isolates of Rhizobium leguminosarum bv. trifolii (the clover root-nodule endosymbiont) from the Nile River delta have been found to infect rice roots and colonize the intercellular spaces of the rice roots. Some of these isolates inhibit rice seedling growth but one in particular, R4, has been found in rice roots which develop and grow normally. We present evidence that the induced growth inhibition is due to a toxic accumulation of nitric oxide (NO), from the reduction of nitrate, and suggest that the reason that R4 does not inhibit rice root growth is because it is capable of completing the reduction of NO through to nitrogen gas. Thus, strain R4 is a candidate for engineering into a future biological nitrogen fixation system within these roots. PMID:17378431

  14. Isolation and characterization of Rhizobium meliloti mutants affected in exopolysaccharide production.

    Science.gov (United States)

    Rodríguez-Navarro, D N; Palomares, A J; Casadesús, J

    1991-06-01

    Rhizobium meliloti mutants affected in the production of exopolysaccharide (EPS) were isolated after N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis. The mutants were classified into three phenotypic classes: (I) Exo-, rough mutants lacking exopolysaccharide; (II) Exos (for "small") which form tiny, compact colonies and synthesize reduced amounts of EPS; and (III) Exoc (for "constitutive"), hypermucoid mutants which overproduce EPS. Hypermucoid strains showed increased resistance to desiccation. All the mutants were able to nodulate, although a significant decrease in infectivity degree and/or competitiveness was found in rough and compact strains. Two mutants proved to be deficient in nitrogen fixation. Complementation analysis with cloned R. meliloti exo genes could not be applied to the study of these Fix- mutants because introduction of plasmids derived from cosmid vector pLAFR1 caused loss of nodulating ability. However, complementation of calcofluor staining and EPS production was observed. Complementation with certain exo genes also caused a marked increase in motility. PMID:1867774

  15. Mutations inducing an active-site aperture in Rhizobium sp. sucrose isomerase confer hydrolytic activity.

    Science.gov (United States)

    Lipski, Alexandra; Watzlawick, Hildegard; Ravaud, Stéphanie; Robert, Xavier; Rhimi, Moez; Haser, Richard; Mattes, Ralf; Aghajari, Nushin

    2013-02-01

    Sucrose isomerase is an enzyme that catalyzes the production of sucrose isomers of high biotechnological and pharmaceutical interest. Owing to the complexity of the chemical synthesis of these isomers, isomaltulose and trehalulose, enzymatic conversion remains the preferred method for obtaining these products. Depending on the microbial source, the ratio of the sucrose-isomer products varies significantly. In studies aimed at understanding and explaining the underlying molecular mechanisms of these reactions, mutations obtained using a random-mutagenesis approach displayed a major hydrolytic activity. Two of these variants, R284C and F164L, of sucrose isomerase from Rhizobium sp. were therefore crystallized and their crystal structures were determined. The three-dimensional structures of these mutants allowed the identification of the molecular determinants that favour hydrolytic activity compared with transferase activity. Substantial conformational changes resulting in an active-site opening were observed, as were changes in the pattern of water molecules bordering the active-site region. PMID:23385465

  16. Comparison of characteristics of the nodX genes from various Rhizobium leguminosarum strains.

    Science.gov (United States)

    Ovtsyna, A O; Rademaker, G J; Esser, E; Weinman, J; Rolfe, B G; Tikhonovich, I A; Lugtenberg, B J; Thomas-Oates, J E; Spaink, H P

    1999-03-01

    We have analyzed the nucleotide sequences of the nodX genes from two strains of Rhizobium leguminosarum bv. viciae able to nodulate Afghan peas (strains A1 and Himalaya) and from two strains of R. leguminosarum bv. trifolii (ANU843 and CSF). The nodX genes of strains A1 and ANU843 were shown to be functional for the induction of nodules on Afghan peas. To analyze the cause of phenotypic differences of strain A1 and strain TOM we have studied the composition of the lipochitin-oligosaccharides (LCOs) produced by strain A1 after induction by the flavonoid naringenin or various pea root exudates. The structural analysis of the LCOs by mass spectrometry revealed that strain A1 synthesizes a family of at least 23 different LCOs. The use of exudates instead of naringenin resulted only in quantitative differences in the ratios of various LCOs produced. PMID:10065561

  17. Transposon mutagenesis and complementation of the fructokinase gene in Rhizobium leguminosarum biovar trifolii.

    Science.gov (United States)

    McLaughlin, R E; Hughes, T A

    1989-08-01

    Transposon Tn5 was used to generate a fructokinase mutation in Rhizobium leguminosarum biovar trifolii BAL. The section of the genome containing Tn5 was cloned into the EcoRI site of the vector pHC79 and isolated by direct selection on medium containing kanamycin and tetracycline. Total EcoRI digestion was used to obtain a single fragment containing Tn5 and flanking DNA sequences. The flanking DNA was used as a probe to isolate an intact fructokinase gene from a pLAFR1 cosmid clone bank of the parental strain. A cosmid showing homology to the probe was tri-parentally conjugated into the fructokinase-negative strain, complementing the mutation. The complemented mutant exhibited the wild-type phenotype, with an increase in fructokinase production presumably due to multiple copies of the gene. PMID:2561289

  18. The morphogenesis of lupine root nodules during infection by Rhizobium lupini

    Directory of Open Access Journals (Sweden)

    W?adys?aw Golinowski

    1987-12-01

    Full Text Available The development of root nodules in Lupinus luteus infected by Rhizobium lupini was studied using cytological methods. The results obtained from examination of material sampled 6, 9, 13, 15, 20, 29 and 60 days after infection are given. The successive stages of development are described and the cytological characteristics of the tissue are presented. The mitotic divisions of the root cortex parenchyma cells, which initiated the formation of the nodule primordium, were accompanied by structural changes in the root hairs and divisions in the root pericycle. The development of the nodule was associated with the activity of the lateral meristems, which encompass both the infected cells and cells not containing bacteroids Characteristics of bacteria found in the symplast and apoplast of the bacteroid tissue are given.

  19. Effect of Rhizobium inoculation of seeds and foliar fertilization on productivity of Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Tadeusz Zaj?c

    2013-07-01

    Full Text Available Pea (Pisum sativum L. is the second most important grain legume crop in the world which has a wide array of uses for human food and fodder. One of the major factors that determines the use of field pea is the yield potential of cultivars. Presently, pre-sowing inoculation of pea seeds and foliar application of microelement fertilizers are prospective solutions and may be reasonable agrotechnical options. This research was undertaken because of the potentially high productivity of the 'afila' morphotype in good wheat complex soils. The aim of the study was to determine the effect of vaccination with Rhizobium and foliar micronutrient fertilization on yield of the afila pea variety. The research was based on a two-year (2009–2010 controlled field experiment, conducted in four replicates and carried out on the experimental field of the Bayer company located in Modzurów, Silesian region. experimental field soil was Umbrisol – slightly degraded chernozem, formed from loess. Nitragina inoculant, as a source of symbiotic bacteria, was applied before sowing seeds. Green area index (GAI of the canopy, photosynthetically active radiation (PAR, and normalized difference vegetation index (NDVI were determined at characteristic growth stages. The presented results of this study on symbiotic nitrogen fixation by leguminous plants show that the combined application of Nitragina and Photrel was the best combination for productivity. Remote measurements of the pea canopy indexes indicated the formation of the optimum leaf area which effectively used photosynthetically active radiation. The use of Nitragina as a donor of effective Rhizobium for pea plants resulted in slightly higher GAI values and the optimization of PAR and NDVI. It is not recommended to use foliar fertilizers or Nitragina separately due to the slowing of pea productivity.

  20. Interacción de Tsukamurella paurometabola C-924 con Rhizobium leguminosarum biovar phaseoli CFH en el cultivo de frijol / Interaction among Tsukamurella paurometabola C-924 and Rhizobium leguminosarum biovar phaseoli CFH in bean plants

    Scientific Electronic Library Online (English)

    Marieta, Marín Bruzos; Jesús, Mena Campos; Pavel, Chaveli Chávez; Rolando, Morán Valdivia; Eulogio, Pimentel Vázquez.

    2013-01-01

    Full Text Available En el estudio se evaluaron, mediante análisis de los parámetros fenológicos de las plantas, la interacción de Tsukamurella paurometabola C-924 con Rhizobium leguminosarum biovar phaseoli CFH en el cultivo de frijol. Se emplearon cuatro tratamientos: plantas sin inocular (control), inoculadas con T. [...] paurometabola C-924, inoculadas con R. leguminosarum biovar phaseoli CFH e inoculadas con ambas cepas. Se observaron diferencias significativas (P Abstract in english The experiment was carried out to evaluate the interaction between Tsukamurella paurometabola C-924 and Rhizobium leguminosarum biovar phaseoli CFH in bean plants. Treatments consisted of non-inoculated plants (control), plants inoculated with T. paurometabola C-924, inoculated with R. leguminosarum [...] biovar phaseoli CFH and inoculated with both strains. The application of the microorganisms single or in coinoculation improved the germination of seeds. T. paurometabola C-924 did not enhanced Rhizobium nodulation. However, no significant differences were found among treatments for shoot height and diameter. There was an increase in number of leaves in the plants inoculated with T. paurometabola C-924. We concluded that the interaction between T. paurometabola C-924 and R. leguminosarum biovar phaseoli CFH improved the number of leaves and the germination of seeds and even though T. paurometabola C-924 did not enhance nodulation, this fact did not affect the plants growth.

  1. Dual inoculation with an Aarbuscular Mycorrhizal fungus and Rhizobium to facilitate the growth of alfalfa on coal mine substrates

    Energy Technology Data Exchange (ETDEWEB)

    Wu, F.Y.; Bi, Y.L.; Wong, M.H. [China University of Mining & Technology, Beijing (China)

    2009-07-01

    A pot experiment was conducted to investigate the effects of Glomus mosseae and Rhizobium on Medicago sativa grown on three types of coal mine substrates, namely a mixture of coal wastes and sands (CS), coal wastes and fly ash (CF), and fly ash (FA). Inoculation with Rhizobium alone did not result in any growth response but G. mosseae alone displayed a significant effect on plant growth. G. mosseae markedly increased the survival rate of M. sativa in CS substrate. In CF and FA substrates the respective oven dry weights of M. sativa inoculated with G. mosseae were 1.8 and 5.1 times higher than those without inoculation. Based on nitrogen (N), phosphorus (P) and potassium (K) uptake and legume growth, the results also show that dual inoculation in CS and CF substrates elicited a synergistic effect. This indicates that inoculation with arbuscular mycorrhizal (AM) fungi may be a promising approach for revegetation of coal mine substrates.

  2. Role of Rhizobium endoglucanase CelC2 in cellulose biosynthesis and biofilm formation on plant roots and abiotic surfaces

    OpenAIRE

    Robledo, M.; Rivera, L.; Jime?nez-zurdo, Jose I.; Rivas, R.; Dazzo, F.; Vela?zquez, E.; Marti?nez-molina, E.; Hirsch, Ann M.; Mateos, Pedro F.

    2012-01-01

    Abstract Background The synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. In this study, we analyzed both the production of cellulose by all known members of the Rhizobiaceae and the diversity of Rhizobium celABC operon predicted to be involved in cellulose biosynthesis. We also investigated the involvement in cellulose production and biofilm formation of celC gene encodi...

  3. The Determination of Symbiotic Effectiveness of Rhizobium Strains Isolated from Wild Chickpeas Collected from High Altitudes in Erzurum

    OpenAIRE

    Ö?ÜTÇÜ, Hatice; ALGUR, Ömer Faruk; Elkoca, Erdal; Kantar, Faik

    2008-01-01

    This study was conducted in order to evaluate the symbiotic effectiveness of Rhizobium leguminosarum subsp. ciceri strains isolated from perennial wild chickpeas (Cicer anatolicum) collected from high altitudes (2000-2500 m) in mountains in Erzurum, Eastern Anatolia, Turkey. For this purpose, 21 isolates were obtained from wild chickpeas. Chickpea seeds were inoculated with these isolates and grown in pots containing sterile sand under both low (15 °C day/9 °C night) and normal (25 °C day/...

  4. Biodegradation of Selected Nigerian Fruit Peels by the use of a Non-pathogenic Rhizobium species CWP G34B

    OpenAIRE

    Esther Boboye, Bolatito; Ajayi, George Olarewaju

    2012-01-01

    This study was carried out to determine the ability of Rhizobium species CWP G34B to degrade the peels of selected Nigerian fruits. The potential of the bacterium to digest some carbon sources (lactose, maltose, sucrose and mannitol) and peels of some Nigerian fruits (pineapple, orange, plantain, banana, pawpaw and mango fruits) was investigated by growing the organism on the substances separately after which DNSA reagent method was used to quantify glucose released into the mediu...

  5. Nucleotide Sequence and Genetic Structure of a Novel Carbaryl Hydrolase Gene (cehA) from Rhizobium sp. Strain AC100

    OpenAIRE

    Hashimoto, Masayuki; Fukui, Mitsuru; Hayano, Kouichi; Hayatsu, Masahito

    2002-01-01

    Rhizobium sp. strain AC100, which is capable of degrading carbaryl (1-naphthyl-N-methylcarbamate), was isolated from soil treated with carbaryl. This bacterium hydrolyzed carbaryl to 1-naphthol and methylamine. Carbaryl hydrolase from the strain was purified to homogeneity, and its N-terminal sequence, molecular mass (82 kDa), and enzymatic properties were determined. The purified enzyme hydrolyzed 1-naphthyl acetate and 4-nitrophenyl acetate indicating that the enzyme is an esterase. We then...

  6. Catabolite repression and role of cyclic AMP in CO2 fixation and H2 metabolism in Rhizobium spp.

    OpenAIRE

    Mcgetrick, A. M.; Goulding, C. F.; Manian, S. S.; O Gara, F.

    1985-01-01

    CO2 fixation in Rhizobium meliloti was repressed by a variety of organic carbon sources. Cellular cyclic AMP levels were similar in repressed and nonrepressed cultures. Exogenous cyclic AMP or additional copies of the adenyl cyclase gene in cells experiencing repression failed to affect the rates of CO2 fixation. However, in R. japonicum catabolite repression of H2 utilization was partially circumvented by the presence of the R. meliloti adenyl cyclase gene.

  7. Mutualism and Adaptive Divergence: Co-Invasion of a Heterogeneous Grassland by an Exotic Legume-Rhizobium Symbiosis

    OpenAIRE

    Porter, Stephanie S.; Stanton, Maureen L.; Rice, Kevin J

    2011-01-01

    Species interactions play a critical role in biological invasions. For example, exotic plant and microbe mutualists can facilitate each other's spread as they co-invade novel ranges. Environmental context may influence the effect of mutualisms on invasions in heterogeneous environments, however these effects are poorly understood. We examined the mutualism between the legume, Medicago polymorpha, and the rhizobium, Ensifer medicae, which have both invaded California grasslands. Many of these ...

  8. Relationship of the Presence and Copy Number of Plasmids to Exopolysaccharide Production and Symbiotic Effectiveness in Rhizobium fredii USDA 206 †

    OpenAIRE

    Barbour, W. Mark; Elkan, Gerald H.

    1989-01-01

    Rhizobium fredii USDA 206 harbors four large plasmids, one of which carries nodulation and nitrogen fixation genes. Previously isolated groups of plasmid-cured derivatives of strain USDA 206 were compared with each other to determine possible plasmid functions. Mutant strain 206CANS was isolated as a nonmucoid (Muc?) derivative of strain 206CA, a mutant that was cured of two plasmids. The Muc? phenotype of 206CANS was only expressed when the strain was grown on certain media, particularly...

  9. Efeito residual da vinhaça na população autóctone de Rhizobium do solo Residual effects of sugar cane vinasse on indigenous Rhizobia

    OpenAIRE

    Eli Sidney Lopes; Sonia Cristina Perón; Edilberto Princi Portugal; Antonio Roberto Giardini

    1986-01-01

    A adição de vinhaça na cultura canavieira tem sido praticada em áreas próximas às usinas de cana. Seria de interesse a avaliação do efeito da vinhaça no Rhizobium presente no solo (autóctone), uma vez que leguminosas têm sido indicadas para cultivo intercalar com a cana. Um experimento foi conduzido em casa de vegetação, com o objetivo de verificar a influência da aplicação contínua, durante três anos, de concentrações crescentes de vinhaça (0, 100 e 1.000 m³/ha/ano), co...

  10. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    OpenAIRE

    Perotto, S.; Bonfante, P.; Balestrini, R.; Andreotti, S.; Bianciotto, V.

    2009-01-01

    Arbuscular mycorrhizal (AM) fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR). We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium) to AM roots and AM fungal structures. Mutants aff...

  11. Compatibility of Rhizobial Genotypes within Natural Populations of Rhizobium leguminosarum Biovar viciae for Nodulation of Host Legumes

    OpenAIRE

    Laguerre, Gise?le; Louvrier, Philippe; Allard, Marie-reine; Amarger, Noe?lle

    2003-01-01

    Populations of Rhizobium leguminosarum biovar viciae were sampled from two bulk soils, rhizosphere, and nodules of host legumes, fava bean (Vicia faba) and pea (Pisum sativum) grown in the same soils. Additional populations nodulating peas, fava beans, and vetches (Vicia sativa) grown in other soils and fava bean-nodulating strains from various geographic sites were also analyzed. The rhizobia were characterized by repetitive extragenomic palindromic-PCR fingerprinting and/or PCR-restriction ...

  12. Effects of Inoculation with Rhizobium on Seed Yield and Yield Components of Common Vetch (Vicia sativa L.)

    OpenAIRE

    Albayrak, Sebahattin; Sevi?may, Cafer S?rr?; To?ngel, O?zgu?r

    2006-01-01

    The effects of inoculation with Rhizobium leguminosarum on seed yield and yield components of common vetch (Vicia sativa L.) were evaluated under Black Sea Coastal Region conditions, Turkey, in the 2001-2002 and 2002-2003 growing seasons using common vetch cultivars Kubilay, Ürem, Karaelçi, Uluda?, Emir, Çubuk and Nilüfer. The experiment was established as a split block design with 3 replications. Inoculation increased seed yield and all yield components of common vetch cultivars. It was...

  13. Rhizobium nod genes are involved in the induction of two early nodulin genes in Vicia sativa root nodules.

    OpenAIRE

    Moerman, M.; Nap, J. P. H.; Govers, F.; Schilperoort, R.; Kammen, A.; Bisseling, T.

    1987-01-01

    Nodulin gene expresison was studied in Vicia sativa (common vetch) root nodules induced by several Rhizobium and Agrobacterium strains. An Agrobacterium transconjugant containing a R. leguminosarum symplasmid instead of its Ti-plasmid, that was previously shown to form empty nodules on pea, induced nodules on Vicia roots in which nodule cells were infected with bacteria. In the Vicia nodules induced by this transconjugant, two so-called early nodulin genes were found to be expressed, whereas ...

  14. Modulation of Metabolism and Switching to Biofilm Prevail over Exopolysaccharide Production in the Response of Rhizobium alamii to Cadmium

    OpenAIRE

    Schue, Mathieu; Fekete, Agnes; Ortet, Philippe; Brutesco, Catherine; Heulin, Thierry; Schmitt-kopplin, Philippe; Achouak, Wafa; Santaella, Catherine

    2011-01-01

    Heavy metals such as cadmium (Cd2+) affect microbial metabolic processes. Consequently, bacteria adapt by adjusting their cellular machinery. We have investigated the dose-dependent growth effects of Cd2+ on Rhizobium alamii, an exopolysaccharide (EPS)-producing bacterium that forms a biofilm on plant roots. Adsorption isotherms show that the EPS of R. alamii binds cadmium in competition with calcium. A metabonomics approach based on ion cyclotron resonance Fourier transform mass spectrometry...

  15. Two rhizobacterial strains, individually and in interactions with Rhizobium sp., enhance fusarial wilt control, growth, and yield in pigeon pea.

    Science.gov (United States)

    Dutta, Swarnalee; Morang, Pranjal; Kumar S, Nishanth; Dileep Kumar, B S

    2014-09-01

    A Pseudomonas aeruginosa strain, RRLJ 04, and a Bacillus cereus strain, BS 03, were tested both individually and in combination with a Rhizobium strain, RH 2, for their ability to enhance plant growth and nodulation in pigeon pea (Cajanus cajan L.) under gnotobiotic, greenhouse and field conditions. Both of the rhizobacterial strains exhibited a positive effect on growth in terms of shoot height, root length, fresh and dry weight, nodulation and yield over the non-treated control. Co-inoculation of seeds with these strains and Rhizobium RH 2 also reduced the number of wilted plants, when grown in soil infested with Fusarium udum. Gnotobiotic studies confirmed that the suppression of wilt disease was due to the presence of the respective PGPR strains. Seed bacterization with drug-marked mutants of RRLJ 04 and BS 03 confirmed their ability to colonize and multiply along the roots. The results suggest that co-inoculation of these strains with Rhizobium strain RH 2 can be further exploited for enhanced growth, nodulation and yield in addition to control of fusarial wilt in pigeon pea. PMID:25224506

  16. Quantitative analysis of the naringenin-inducible proteome in Rhizobium leguminosarum by isobaric tagging and mass spectrometry.

    Science.gov (United States)

    Tolin, Serena; Arrigoni, Giorgio; Moscatiello, Roberto; Masi, Antonio; Navazio, Lorella; Sablok, Gaurav; Squartini, Andrea

    2013-06-01

    The rhizobium-legume interaction is a critical cornerstone of crop productivity and environmental sustainability. Its potential improvement relies on elucidation of the complex molecular dialogue between its two partners. In the present study, the proteomic patterns of gnotobiotic cultures of Rhizobium leguminosarum bv. viciae 3841 grown for 6 h in presence or absence of the nod gene-inducing plant flavonoid naringenin (10 ?M) were analyzed using the iTRAQ approach. A total of 1334 proteins were identified corresponding to 18.67% of the protein-coding genes annotated in the sequenced genome of bv. viciae 3841. The abundance levels of 47 proteins were increased upon naringenin treatment showing fold change ratios ranging from 1.5 to 25 in two biological replicates. Besides the nod units, naringenin enhanced the expression of a number of other genes, many of which organized in operons, including ?(1-2) glucan production and secretion, succinoglycan export, the RopA outer membrane protein with homology to an oligogalacturonide-specific porin motif, other enzymes for carbohydrate and amino acid metabolism, and proteins involved in the translation machinery. Data were validated at the transcriptional and phenotypic levels by RT-PCR and an assay of secreted sugars in culture supernatants, respectively. The current approach provides not only a high-resolution analysis of the prokaryotic proteome but also unravels the rhizobium molecular dialogue with legumes by detecting the enhanced expression of several symbiosis-associated proteins, whose flavonoid-dependency had not yet been reported. PMID:23580418

  17. INTERACCIÓN RHIZOBIUM LEGUMINOSARUM BV TRIFOLII Y HONGOS MICORRÍCICOS EN UN ANDISOL CON DIFERENTES NIVELES DE SATURACIÓN DE ALUMINIO / INTERACTION OF RHIZOBIUM LEGUMINOSARUM BV TRIFOLII AND MYCORRHIZAL FUNGI IN AN ANDISOL AT DIFFERENT LEVELS OF ALUMINIUM SATURATION

    Scientific Electronic Library Online (English)

    Claudia G, Castillo R; Rosa, Rubio H; Horacio, Urzúa S; Fernando, Borie B.

    Full Text Available La fitotoxicidad por Al es una seria limitante de la productividad de praderas crecidas sobre suelos volcánicos afectando la nodulación y efectividad de los Rhizobium. El objetivo del estudio consistió en seleccionar cepas de Rhizobium de colección para estudiar su efectividad en Trifolium repens cr [...] ecido en un Andisol con cepas nativas y distinta saturación de Al. Para ello se evaluó previamente en caldo nutritivo la tolerancia a la acidez y toxicidad por Al de 12 cepas de colección mediante control de curvas de crecimiento. Paralelamente, se inocularon los Rhizobium en un Andisol para evaluar su efectividad mediante rendimiento de Trifolium pratense. Se seleccionaron las cepas R-109, R-113 y R-115 para inocularlas en el Andisol utilizando cuatro tratamientos: suelo adicionado de 2 Mg CaCO3 ha-1 (SAl1), un testigo (SAl2) y suelo adicionado de dos niveles de saturación Al (SAl1, SAl4) utilizando Trifolium repens como hospedero. Las plantas mostraron capacidad para asociarse con las especies inoculadas presentando mayor efectividad R-113-SAl1 sinergismo positivo expresado en variables microbiológicas como nodulación (16 nódulos maceta-1), esporas de hongos micorrícicos arbusculares, HMA (384 esporas 100g-1), colonización HMA (45%) junto con variables agronómicas alcanzándose un incremento de biomasa foliar (93,5%) frente al testigo. Niveles más elevados de Al afectaron la inoculación con cepas de colección; así, con R-109 se obtuvo el menor crecimiento radical y nodulación respecto al suelo natural mientras que R-113 fue la cepa más efectiva. Abstract in english Aluminium phytotoxicity is a serious limitation of the productivity of prairies growing on volcanic soil by affecting nodulation and effectiveness of Rhizobium. The aim of this study was to select Rhizobium strains to determine the effect as inoculant on Trifolium repens cropped in an Andisol with d [...] ifferent aluminium saturation levels. Acidity tolerance (pH 4.5 and 6.0) of twelve Rhizobium strains of collection at three Al levels (100, 200, 300 µM) was evaluated in mineral nutritive medium vitro. Simultaneously, in a greenhouse trial, strains effectivity were tested by inoculation of Trifolium pratense growing in an acidic Andisol and compared with dry matter accumulation produced by native strains. According to the results of this two trials, three Rhizobium strains (R-109, R-113 and R-115) were selected to study the effect of their inoculation on Trifolium repens growth cropped in an Andisol at four Al saturation levels (SAl1 to SAl4). In addition, the effect on arbuscular mycorrhizal propagules was also studied. Plants showed different capacity for association with the inoculated strains giving the best response R-113 at SAl1 level with positive synergism expressed by microbiological parameters such as high nodulation (16 nodules pot-1), AMF spore number (384 spores 100 g-1), root colonization percentage (45%), together with agronomical variables with an increase of aerial phytomass (93,5%) in comparison with the control. Higher Al levels had an deleterious effect on the inoculation of collection strains; therefore, with R-109 strain inoculation the smallest root growth and nodulation were observed in comparison with soil with native strains whereas R-113 was the more effective one.

  18. Selection of Rhizobium strain from Wonogiri, Central Java on the growth of soybean (Glycine max L. on the sand sterile medium in greenhouse

    Directory of Open Access Journals (Sweden)

    SRI PURWANINGSIH

    2005-07-01

    Full Text Available An experiment on the selection of Rhizobium strain from Wonogiri, Central Java on the growth of soybean (Glycine max L. on the sand sterile medium in green house. The aim of the experiment the selection and potency of the Rhizobium strain to increase the growth of soybean. The experiment was carried out in green house condition in Microbiology Division, Research Center for Biology-LIPI with sterile sand medium. The research design was Completely Randomized Design with three replications for each treatment. The Rhizobium strains used were 1 W (isolated from bean, Vigna radiata, 2 W (isolated from soybean, 3 W (isolated from bean, 4 W (isolated from soybean, 5 W (isolated from soybean, 6 W (isolated from peanut, Arachis hypogaea, 7 W (isolated from peanut, 8 W (isolated from peanut, the controls were uninoculated with Rhizobium strain and without urea fertilizer (K1, uninoculated and with urea fertilizer equal 100 kg/ha (K2. The plants were harvested after 50 days, the variable of investigation were the dry weight of canopy, roots, nodules root, total plants, number of nodules and ‘symbiotic capacity”. The results showed that all of experiment plant which be inoculated with Rhizobium able to form nodule. Strain of 2 W (isolated from soybean has given the best effects on the growth of soybean.

  19. Osmotic control of glycine betaine biosynthesis and degradation in Rhizobium meliloti

    International Nuclear Information System (INIS)

    Intracellular accumulation of glycine betaine has been shown to confer an enhanced level of osmotic stress tolerance in Rhizobium meliloti. In this study, the authors used a physiological approach to investigate the mechanism by which glycine betaine is accumulated in osmotically stressed R. meliloti. Results from growth experiments, 14C labeling of intermediates, and enzyme activity assays are presented. The results provide evidence for the pathway of biosynthesis and degradation of glycine betaine and the osmotic effects on this pathway. High osmolarity in the medium decreased the activities of the enzymes involved in the degradation of glycine betaine but not those of enzymes that lead to its biosynthesis from choline. Thus, the concentration of the osmoprotectant glycine betaine is increased in stressed cells. This report demonstrates the ability of the osmolarity of the growth medium to regulate the use of glycine betaine as a carbon and nitrogen source or as an osmoprotectant. The mechanisms of osmoregulation in R. meliloti and Escherichia coli are compared

  20. Rhizobium sp. effects, irradiated with ultraviolet and gamma rays, on nodulation of P. vulgaris (L.) bean

    International Nuclear Information System (INIS)

    Indigenous isolates of Rhizobium sp. from the root nodules of bean were selected. There of these isolates and a R. leguminosarum biovar phaseoli (SEMIA 4064) strain, used as a reference, were irradiated with ultraviolet (UV) light and gamma-Rays (?-R). The relations between survival and fluence of UV, and survival and absorbed dose of ?-R were linear for the strain of reference. The D37 values, for this rhizobial strain were 43 j.m-2 for the UV-treatment, and 32 Gy for the ?-rays treatment. Through a greenhouse experiment the irradiated isolates were inoculated on bean seedlings (P. vulgaris L, Variety IPA-8), in an attempt to evaluate sensitivity of the host-plants and possible effects on their nodulation. Significant differences were observed only for root dry matter yield. For all the other evaluated parameters variance was of such magnitude that it was not possible to detect significance of the effects. The isolates tested showed difference in responses to nodulation, due to the effects of irradiations. The host plant (IPA-8) seemed to be sensitive to the possible modifications in the irradiated isolates. (author). 10 refs, 6 figs, 1 tab

  1. Rhizobium alters inducible defenses in broad bean, Vicia faba

    Directory of Open Access Journals (Sweden)

    Edward Brian Mondor

    2011-11-01

    Full Text Available Conversion of inorganic nitrogen by mutualistic nitrogen-fixing bacteria is essential for plant growth and reproduction, as well as the development of chemical and mechanical defenses. It is unclear, however, how these bacteria alter co-occurring symbioses at higher trophic levels; e.g., extrafloral nectary (EFN induction, in response to herbivory, to attract defensive mutualists. We hypothesized that plants colonized by nitrogen-fixing bacteria would mount a larger inducible, defensive response than plants lacking symbioses, as defensive traits are costly. We predicted that bean plants, Vicia faba L., harboring Rhizobium leguminosarum bv. viciae Frank would produce more EFNs upon leaf damage, than plants lacking the symbionts, as EFN induction in V. faba is resource-dependent. Here we report that V. faba colonized by R. leguminosarum produced similar numbers of EFNs as did plants without symbionts. Plants with symbionts, however, produced significantly fewer EFNs over 1 week in response to leaf damage, than those without leaf damage. As such, nitrogen-fixing bacteria may not always benefit the host plant, but rather, the utility of these bacteria may be dependent on the prevailing ecological conditions.

  2. Escherichia coli BdcA controls biofilm dispersal in Pseudomonas aeruginosa and Rhizobium meliloti

    Science.gov (United States)

    2011-01-01

    Background Previously we showed that BdcA controls Escherichia coli biofilm dispersal by binding the ubiquitous bacterial signal cyclic diguanylate (c-di-GMP); upon reducing the concentration of c-di-GMP, the cell shifts to the planktonic state by increasing motility, decreasing aggregation, and decreasing production of biofilm adhesins. Findings Here we report that BdcA also increases biofilm dispersal in other Gram-negative bacteria including Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhizobium meliloti. BdcA binds c-di-GMP in these strains and thereby reduces the effective c-di-GMP concentrations as demonstrated by increases in swimming motility and swarming motility as well as by a reduction in extracellular polysaccharide production. We also develop a method to displace existing biofilms by adding BdcA via conjugation from E. coli in mixed-species biofilms. Conclusion Since BdcA shows the ability to control biofilm dispersal in diverse bacteria, BdcA has the potential to be used as a tool to disperse biofilms for engineering and medical applications. PMID:22029875

  3. Escherichia coli BdcA controls biofilm dispersal in Pseudomonas aeruginosa and Rhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Wood Thomas K

    2011-10-01

    Full Text Available Abstract Background Previously we showed that BdcA controls Escherichia coli biofilm dispersal by binding the ubiquitous bacterial signal cyclic diguanylate (c-di-GMP; upon reducing the concentration of c-di-GMP, the cell shifts to the planktonic state by increasing motility, decreasing aggregation, and decreasing production of biofilm adhesins. Findings Here we report that BdcA also increases biofilm dispersal in other Gram-negative bacteria including Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhizobium meliloti. BdcA binds c-di-GMP in these strains and thereby reduces the effective c-di-GMP concentrations as demonstrated by increases in swimming motility and swarming motility as well as by a reduction in extracellular polysaccharide production. We also develop a method to displace existing biofilms by adding BdcA via conjugation from E. coli in mixed-species biofilms. Conclusion Since BdcA shows the ability to control biofilm dispersal in diverse bacteria, BdcA has the potential to be used as a tool to disperse biofilms for engineering and medical applications.

  4. Genetic derepression of a developmentally regulated lipopolysaccharide antigen from Rhizobium leguminosarum 3841.

    Science.gov (United States)

    Wood, E A; Butcher, G W; Brewin, N J; Kannenberg, E L

    1989-09-01

    Monoclonal antibody AFRC MAC 203 recognizes a developmentally regulated lipopolysaccharide antigen in Rhizobium leguminosarum bv. viciae 3841. Transposon-induced mutants that constitutively expressed MAC 203 antigen were isolated. These strains were morphologically normal, showed no gross abnormalities in lipopolysaccharide size distribution on sodium dodecyl sulfate-polyacrylamide gels, and induced normal nitrogen-fixing nodules. However, the mutants lacked lipopolysaccharide epitopes recognized by another rat monoclonal antibody, AFRC MAC 281, suggesting that the corresponding epitopes may be interconverted or share a common precursor. In conjugational crosses, the transposon insertion associated with both the loss of MAC 281 antigen and the constitutive expression of MAC 203 antigen showed linkage to the chromosomal rif allele. A derivative of strain 3841 with a deletion spanning the nod-fix region of the symbiotic plasmid showed no altered expression pattern for MAC 203 antigen, suggesting that the relevant genetic determinants map to genomic sites that are not associated with nifA or any known genes on the symbiotic plasmid. PMID:2768182

  5. Rhizobium Strain Effects on Yield and Bleeding Sap Amino Compounds in Pisum sativum.

    DEFF Research Database (Denmark)

    Rosendahl, Lis

    1984-01-01

    Bleeding sap composition, dry matter production and N distribution in pea (P. sativum L. cv. Bodil) grown with and without nitrate and nodulated with either R. leguminosarum strain 128c53 or strain 1044 were compared. Nitrate increased the total dry matter production of both symbioses, but decreased both the proportions of belowground dry matter to total dry matter production and nodule dry matter to total belowground dry matter production. The total dry matter yield and N accumulation was greater in the symbiosis with strain 1044, whereas the accumulation of N in the roots plus nodules relative to the total N-accumulation was greater with strain 128c53 due to a higher production of nodule tissue. The root bleeding sap of the symbiosis with the greater yield (strain 1044) contained high levels of asparagine and aspartic acid. In the 128c53 symbiosis, glutamine plus homoserine accounted for a higher percentage of the organic solutes transporting newly assimilated N from the root system than in the association with 1044. The Rhizobium strain effect on amino compound composition of the bleeding sap may indicate an influence of the bacteroids on either the N-assimilatory enzyme system in the plant cytosol, or on the pools of the Krebs cycle intermediates or related compounds in the nodules.

  6. Isolation and the interaction between a mineral-weathering Rhizobium tropici Q34 and silicate minerals.

    Science.gov (United States)

    Wang, Rong Rong; Wang, Qi; He, Lin Yan; Qiu, Gang; Sheng, Xia Fang

    2015-05-01

    The purposes of this study were to isolate and evaluate the interaction between mineral-weathering bacteria and silicate minerals (feldspar and biotite). A mineral-weathering bacterium was isolated from weathered rocks and identified as Rhizobium tropici Q34 based on 16S rRNA gene sequence analysis. Si and K concentrations were increased by 1.3- to 4.0-fold and 1.1- to 1.7-fold in the live bacterium-inoculated cultures compared with the controls respectively. Significant increases in the productions of tartaric and succinic acids and extracellular polysaccharides by strain Q34 were observed in cultures with minerals. Furthermore, significantly more tartaric acid and polysaccharide productions by strain Q34 were obtained in the presence of feldspar, while better growth and more citric acid production of strain Q34 were observed in the presence of biotite. Mineral dissolution experiments showed that the organic acids and polysaccharides produced by strain Q34 were also capable of promoting the release of Si and K from the minerals. The results showed that the growth and metabolite production of strain Q34 were enhanced in the presence of the minerals and different mineral exerted distinct impacts on the growth and metabolite production. The bio-weathering process is probably a synergistic action of organic acids and extracellular polysaccharides produced by the bacterium. PMID:25716616

  7. Effect of Leguminous Lectins on the Growth of Rhizobium tropici CIAT899

    Directory of Open Access Journals (Sweden)

    Mayron Alves de Vasconcelos

    2013-05-01

    Full Text Available Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.

  8. Versatile properties of an exopolysaccharide R-PS18 produced by Rhizobium sp. PRIM-18.

    Science.gov (United States)

    Priyanka, P; Arun, A B; Ashwini, P; Rekha, P D

    2015-08-01

    Exopolysaccharides (EPS) produced by bacteria have attracted scientific and industrial attention due to their multifunctional properties and relatively easier production. In this study, an EPS viz., R-PS18 produced by Rhizobium sp. PRIM-18 was characterized and its functional properties were assessed. Cell proliferative and in vitro wound healing activities of the EPS were established using human dermal fibroblast (HDF) cells. The isolate produced 2.1gL(-1) purified EPS (molecular weight 9.33×10(6)Da) comprising of glucose, galactose, and mannose (6.1:1.8:1). Viscosity of 0.25% solution was 23.4mPas (shear rate 75s(-1)) and it showed pseudoplastic and thixotropic behavior. High emulsification, iron chelation, and superoxide scavenging abilities were also observed. Significant increase in HDF cell proliferation and wound healing in vitro was achieved by R-PS18 treatment. Sulfation of R-PS18 significantly enhanced the cell proliferative and wound healing activities. In conclusion, these findings indicate potential applications of R-PS18. PMID:25933542

  9. Evaluación de diferentes sistemas de fermentación para la producción de ácido indolacético por Rhizobium sp

    Directory of Open Access Journals (Sweden)

    Beatriz Altuna

    2006-01-01

    Full Text Available Las investigaciones relacionadas con la producción microbiológica de hormonas de crecimiento vegetal tienen hoy amplia actualidad, no sólo por los efectos beneficiosos que éstas producen en diversos cultivos, sino también por su alta compatibilidad con el ambiente. Un ejemplo interesante de ello lo constituye el ácido indolacético. En esta investigación se describe la producción de AIA en un cultivo intermitente con una cepa de Rhizobium sp. Pudo comprobarse que la relación de formación biomasa-producto obedece a una clasificación del tipo "parcialmente asociada". La velocidad o rapidez específica de proliferación ("crecimiento" máxima fue de 0.12 h-1, alcanzando la concentración de AIA valores de 340 mg/l. Dos sistemas de biorreacción del tipo intermitente incrementado ("fed-batch" fueron evaluados, mostrando el sistema de alimentación exponencial ventajas significativas en el proceso al obtenerse valores de productividades máximas de 16 mg/l-h, es decir, incrementos en esta respuesta del 60 % y concentraciones de AIA máximas de 467 mg/l.

  10. Preparation and biological evaluation of a novel selenium-containing exopolysaccharide from Rhizobium sp. N613.

    Science.gov (United States)

    Ding, Guo-Bin; Nie, Rui-Hong; Lv, Li-Hua; Wei, Guo-Qin; Zhao, Liang-Qi

    2014-08-30

    In order to obtain a low toxic antitumor agent and an organic selenium source, an exopolysaccharide obtained from Rhizobium sp. N613 (REPS) was modified by selenious acid using barium chloride as the catalyst. The reaction conditions were optimized by response surface methodology (RSM), and the optimal conditions for preparation of selenium-containing REPS (Se-REPS) were obtained. The selenium content of Se-REPS was 790 ?g/g under these conditions. The molecular structure of Se-REPS was confirmed by FTIR. In vitro antitumor activity of Se-REPS was evaluated by MTT assay, and the results indicated that Se-REPS could significantly inhibit the growth of S180 and HepG2 cells. Furthermore, Se-REPS exhibited comparable in vivo antitumor efficacy to cyclophosphamide at same concentrations. In addition, Se-REPS could substantially elevate the thymus and spleen indices in tumor-bearing mice. This study demonstrates that Se-REPS holds great potential to be a desirable antitumor agent for therapeutic and immunomodulatory applications. PMID:24815397

  11. Role of Some Chemical Compounds on the Detoxification of Rhizobium leguminsarum biovar vicia by Some Heavy Metals

    OpenAIRE

    Sanaa Mostafa El-Deeb; Fawziah Saleh Al-Sheri

    2005-01-01

    The toxic effect of different concentrations of some heavy metals (Cadmium, Zinc and Lead) on the growth of cultured Rhizobium leguminsarum biovar vicia was studied and their LD50 toxicity were determined. The 50% inhibition of bacterial growth was achieved by contaminating the culture with 2.1 ?M of Cadmium, 30 ?M of Zinc or 290 ?M of Lead. In attempts to counteract the toxic effect of these heavy metals, several compounds were tested to reactivate the Rhizobium growth and to abolish the ...

  12. Involvement of both cellulose fibrils and a Ca2+-dependent adhesin in the attachment of Rhizobium leguminosarum to pea root hair tips.

    OpenAIRE

    Smit, G.; Kijne, J. W.; Lugtenberg, B. J.

    1987-01-01

    We have previously described an assay for the attachment of Rhizobium bacteria to pea root hair tips (cap formation) which was used as a model to study the attachment step in the nodulation process. Under all conditions tested, a positive correlation was observed between the percentage of fibrillated cells and the ability of these bacteria to form caps and to adhere to glass, suggesting that fibrils play a role in the attachment of Rhizobium leguminosarum to pea root hair tips and to glass (G...

  13. Effects of high temperature on survival, symbiotic performance and genomic modifications of bean nodulating Rhizobium strains Sobrevivência, fixação de nitrogênio e modificações genéticas em estirpes de Rhizobium sp. efetivas na nodulação do feijoeiro, expostas à altas temperaturas

    Directory of Open Access Journals (Sweden)

    Patrícia P. Pinto

    1998-10-01

    Full Text Available High temperatures can affect the survival, establishment and symbiotic properties of Rhizobium strains. Bean nodulating Rhizobium strains are considered particularly sensitive because on this strains genetic recombinations and/or deletions occur frequently, thus compromising the use of these bacteria as inoculants. In this study R. tropici and R. leguminosarum bv. phaseoli strains isolated from Cerrado soils were exposed to thermal stress and the strains’ growth, survival and symbiotic relationships as well as alterations in their genotypic and phenotypic characteristics were analyzed. After successive thermal shocks at 45ºC for four hours, survival capacity appeared to be strain-specific, independent of thermo-tolerance and was more apparent in R. tropici strains. Certain R. leguminosarum bv. phaseoli strains had significant alterations in plant dry weight and DNA patterns obtained by AP-PCR method. R. tropici strains (with the exception of FJ2.21 were more stable than R. leguminosarum bv. phaseoli strains because no significant phenotypic alterations were observed following thermal treatments and they maintained their original genotypic pattern after inoculation in plants.Altas temperaturas podem afetar a sobrevivência, estabelecimento e as propriedades simbióticas em estirpes de Rhizobium. As estirpes capazes de nodular o feijoeiro têm sido consideradas particularmente sensíveis, porque nessas estirpes é comum a ocorrência de recombinações e/ou deleções genômicas comprometendo, muitas vezes, a sua utilização como inoculantes. Neste trabalho, procurou-se avaliar a capacidade de crescimento e sobrevivência em temperaturas elevadas de estirpes de Rhizobium efetivas na fixação de nitrogênio no feijoeiro isoladas dos cerrados, bem como avaliar suas características fenotípicas e genotípicas após choque térmico. A capacidade de sobrevivência à temperaturas elevadas, avaliada após choques térmicos sucessivos (45ºC por 4 horas mostrou ser uma característica própria de cada estirpe, independente de sua termotolerância, que aparentemente foi mais acentuada nas estirpes de R. tropici. Algumas estirpes de R. leguminosarum bv. phaseoli mostraram alterações significativas (Duncan 5% de probabilidade nas suas características fenotípicas (produção de matéria seca após choques térmicos e nos seus padrões genômicos evidenciados pela técnica de AP-PCR. As estirpes de R. tropici foram aparentemente mais estáveis não sendo detectadas alterações fenotípicas significativas e com exceção da estirpe FJ2.21, após choque térmico e inoculação na planta hospedeira, mantiveram o padrão genômico original.

  14. Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.

    Directory of Open Access Journals (Sweden)

    Ormeño-Orrillo Ernesto

    2012-12-01

    Full Text Available Abstract Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are ?-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean and other legume hosts.

  15. Inoculação do feijoeiro com Rhizobium tropici associada à exsudato de Mimosa flocculosa com diferentes doses de nitrogênio / Rhizobium tropici associated with Mimosa flocculosa exudates inoculation effect on bean plants under different nitrogen rates

    Scientific Electronic Library Online (English)

    Eulene Francisco da, Silva; Marlene Estevão, Marchetti; Luiz Carlos Ferreira de, Souza; Fábio Martins, Mercante; Edson Talarico, Rodrigues; Antonio Carlos Tadeu, Vitorino.

    Full Text Available O presente estudo teve como objetivo avaliar os efeitos da inoculação de rizóbio, associada à adição de exsudatos de sementes de Mimosa flocculosa, e/ou de N-mineral nas características agronômicas do feijoeiro, em sucessão à soja e ao milho. O delineamento experimental foi em blocos casualizados, c [...] om quatro repetições, sendo os tratamentos dispostos em parcelas sub-subdivididas. As culturas soja e milho antecessoras à cultura do feijoeiro formaram as parcelas. As subparcelas foram constituídas pelos tratamentos: testemunha sem inoculação, inoculação de Rhyzobium tropici, estirpes CIAT 899 e PRF 81 e a associação deste com os exsudados das sementes de Mimosa flocculosa. As sub-subparcelas constituiram-se de quatro doses de N aplicadas em cobertura: 0, 40, 80 e 120 kg ha-1. A inoculação de rizóbio associada à adição de exsudato de sementes de Mimosa flocculosa contribuiu para o melhor desenvolvimento da parte aérea do feijoeiro. A adubação nitrogenada reduziu, de forma linear, a nodulação do feijoeiro. O milho como cultura antecessora ao feijão contribuiu para o aumento do peso de 100 grãos e a adição de N combinado não contribuiu para o aumento do número de vagens por planta e produtividade de grãos do feijoeiro, independente da dose utilizada. Abstract in english The aim of this work was to evaluate the effect of the Rhizobium inoculation, associated with seed exudates of Mimosa flocculosa, under different rates of nitrogen fertilization was evaluated in bean crops following soybean (Glycine max L. Merril) and corn (Zea mays L.). The experimental design was [...] randomized blocks with four replications, with treatments arranged in sub-divided parcels. The parcels were constituted of two summer crops preceding the common bean crop: soybean and corn. In the sub-parcels three treatments involving inoculation of the common bean seeds were considered: control treatment without inoculation; bean seeds inoculated with Rhizobium tropici, strains CIAT 899 and PRF 81, and the association of Rhizobium with the exudates of the Mimosa flocculosa seeds. The sub-subparcels received of four doses of nitrogen fertilization applied on covering: 0, 40, 80 and 120 kg ha-1 N. The inoculation of Rhizobium associated with the addition of exudates of Mimosa flocculosa seeds resulted in higher shoot dry weight. Besides that, the nitrogen fertilization, on the tested doses, reduced, in a linear way, the nodulation of the bean plant. It was also verified that corn as a preceding crop for bean has contributed to the increase of the weight of 100 grains, while the addition of combined N did not contribute to the improvement on the number of beans per plant, neither of the grain yield of bean plants, independent of the dose that was used.

  16. Biological nitrogen fixation by Rhizobium sp. native gliricidia (Gliricidia sepium [Jacq.] Kunth ex Walp.) under greenhouse conditions / Fijación biológica de nitrógeno por Rhizobium sp. nativo de matarratón (Gliricidia sepium [Jacq.] Kunth ex Walp.) bajo condiciones de invernadero

    Scientific Electronic Library Online (English)

    Juan Guillermo, Cubillos-Hinojosa; Pablo Ernesto, Milian-Mindiola; Jorge Luis, Hernández-Mulford.

    2011-12-01

    Full Text Available Se realizó un experimento bajo condiciones de invernadero con el fin de evaluar la asociación y fijación biológica de nitrógeno (FBN) en seis cepas nativas de Rhizobium sp. aisladas de nódulos de matarratón y una cepa comercial (Rhizobiol©). Las suspensiones de 106 y 108 células/mL para cada una de [...] las cepas estudiadas y aplicadas en dos ensayos separados: el primero con semillas y la segundo con plántulas de 35 días de edad matarratón. En el ensayo de semilla se calcula el porcentaje acumulado de germinación durante 7 días. En ambos ensayos, después de 42 días en las semillas y 52 días en plántulas se determinó la altura y diámetro del tallo, número de hojas, peso seco de la parte aérea, número de nódulos por planta y el porcentaje de nitrógeno. Todos los tratamientos estimularon la germinación, el crecimiento y FBN, siendo mejor en las cepas nativas a una concentración de 108 células/mL, en comparación con la cepa comercial y el control. Estos resultados indican el efecto positivo ejercido por Rhizobium sp., en la promoción del crecimiento y FBN, que podrían ser utilizados para estudios adicionales para determinar la producción de un biofertilizante, permitiendo potenciar la producción de cultivos de matarratón como alimento de ganado bovino como fuente de proteína en el Centro de Biotecnología del Caribe Abstract in english An experiment was conducted under greenhouse conditions in order to evaluate the association and biological nitrogen fixation (BNF), six native strains of Rhizobium sp isolated from nodules gliricidia and a commercial strain (Rhizobiol©). Suspensions of 106 and 108 cells/mL for each of the strains s [...] tudied and applied in two separate trials: the first with seeds and the second with seedlings 35 days of age gliricidia. In the seed test is calculated the cumulative percentage of germination for 7 days. In both trials after 42 days in seeds and seedlings 52 days in length was measured and stem diameter, leaf number, dry weight of aerial parts, number of nodules/plant and percentage of nitrogen. All treatments stimulated germination, growth and BNF, being better in the native strains at a concentration of 108 cells/mL, compared with the commercial strain and the control. These results indicate the positive effect exerted by Rhizobium sp., in promoting growth and BNF, which could be used for further studies to establish the production of a biofertilizer, allowing potentiate the production of crops by gliricidia for food arich cattle as source of protein in the Caribbean Biotechnology Center

  17. Final report Sarajevo'84

    OpenAIRE

    2013-01-01

    Le “Rapport final Sarajevo'84” est un rapport officiel assez modeste mais qui comporte les principales informations utiles. Celles-ci sont proposées dans une édition trilingue française, anglaise et serbo-croate

  18. Two-dimensional proteome reference map of Rhizobium tropici PRF 81 reveals several symbiotic determinants and strong resemblance with agrobacteria.

    Science.gov (United States)

    Gomes, Douglas Fabiano; Batista, Jesiane Stefania da Silva; Torres, Adalgisa Ribeiro; de Souza Andrade, Diva; Galli-Terasawa, Lygia Vitoria; Hungria, Mariangela

    2012-03-01

    Rhizobium tropici strain PRF 81 is used in commercial inoculants for common-bean crops in Brazil because of its high efficiency in nitrogen fixation and, as in other strains belonging to this species, its tolerance of environmental stresses, representing a useful biological alternative to chemical nitrogen fertilizers. In this study, a proteomic reference map of PRF 81 was obtained by two-dimensional gel electrophoresis and MALDI-TOF/TOF-TOF mass spectrometry. In total, 115 spots representing 109 different proteins were successfully identified, contributing to a better understanding of the rhizobia-legume symbiosis and supporting, at proteomics level, a strong resemblance with agrobacteria. PMID:22539436

  19. Light regulates attachment, exopolysaccharide production, and nodulation in Rhizobium leguminosarum through a LOV-histidine kinase photoreceptor

    OpenAIRE

    Bonomi, Herna?n R.; Posadas, Diana M.; Paris, Gasto?n; Carrica, Mariela Del Carmen; Frederickson, Marcus; Pietrasanta, Li?a Isabel; Bogomolni, Roberto A.; Zorreguieta, Angeles; Goldbaum, Fernando A.

    2012-01-01

    Rhizobium leguminosarum is a soil bacterium that infects root hairs and induces the formation of nitrogen-fixing nodules on leguminous plants. Light, oxygen, and voltage (LOV)-domain proteins are blue-light receptors found in higher plants and many algae, fungi, and bacteria. The genome of R. leguminosarum bv. viciae 3841, a pea-nodulating endosymbiont, encodes a sensor histidine kinase containing a LOV domain at the N-terminal end (R-LOV-HK). R-LOV-HK has a typical LOV domain absorption spec...

  20. Deduced products of C4-dicarboxylate transport regulatory genes of Rhizobium leguminosarum are homologous to nitrogen regulatory gene products.

    OpenAIRE

    Ronson, C. W.; Astwood, P. M.; Nixon, B. T.; Ausubel, F. M.

    1987-01-01

    We have sequenced two genes dctB and dctD required for the activation of the C4-dicarboxylate transport structural gene dctA in free-living Rhizobium leguminosarum. The hydropathic profile of the dctB gene product (DctB) suggested that its N-terminal region may be located in the periplasm and its C-terminal region in the cytoplasm. The C-terminal region of DctB was strongly conserved with similar regions of the products of several regulatory genes that may act as environmental sensors, includ...

  1. Cloning, nucleotide sequencing, and expression in Escherichia coli of a Rhizobium leguminosarum gene encoding a symbiotically repressed outer membrane protein.

    OpenAIRE

    Maagd, R. A.; Mulders, I. H.; Canter Cremers, H. C.; Lugtenberg, B. J.

    1992-01-01

    We describe the cloning of a gene from Rhizobium leguminosarum biovar viciae strain 248 encoding protein IIIa, the 36-kDa outer membrane protein forming a part of the outer membrane protein antigen group III. The expression of this antigen group is repressed in the bacteroid form during symbiosis (R. A. de Maagd, R. de Rijk, I. H. M. Mulders, and B. J. J. Lugtenberg, J. Bacteriol. 171:1136-1142, 1989). A cosmid clone expressing the strain 248-specific MAb38 epitope of this antigen group in a ...

  2. Isolation of the Rhizobium leguminosarum NodF nodulation protein: NodF carries a 4'-phosphopantetheine prosthetic group.

    OpenAIRE

    Geiger, O.; Spaink, H. P.; Kennedy, E. P.

    1991-01-01

    Rhizobium species produce a protein product of the nodF gene that has a limited but recognizable homology to the well-characterized acyl carrier protein (ACP) of Escherichia coli. NodF functions together with NodE in generating a host-specific response to the plant host in the interchange of signals leading to the effective nodulation of roots (H.P. Spaink, J. Weinman, M.A. Djordjevic, C.A. Wijffelman, R.J.H. Okker, and B. J.J. Lugtenberg, EMBO J. 8:2811-2818, 1989; B. Scheres, C. van de Wiel...

  3. Agrobacterium tumefaciens virulence locus pscA is related to the Rhizobium meliloti exoC locus.

    OpenAIRE

    Marks, J.R.; Lynch, T. J.; Karlinsey, J E; Thomashow, M. F.

    1987-01-01

    Agrobacterium tumefaciens and Rhizobium meliloti carry related genetic loci which have important roles in virulence and symbiosis. Previously, it was shown that two virulence loci of A. tumefaciens, chvA and chvB, are related to two R. meliloti symbiosis loci, ndvA and ndvB, respectively (T. Dylan, L. Ielpi, S. Stanfield, L. Kashyap, C. Douglas, M. Yanofsky, E. Nester, D. R. Helinski, and G. Ditta, Proc. Natl. Acad. Sci. USA 83:4403-4407, 1986). Here we show that these two phytobacteria posse...

  4. Biological Control of Crown Gall on Grapevine and Root Colonization by Nonpathogenic Rhizobium vitis Strain ARK-1

    OpenAIRE

    Kawaguchi, Akira

    2013-01-01

    A nonpathogenic strain of Rhizobium vitis ARK-1 was tested as a biological control agent for grapevine crown gall. When grapevine roots were soaked in a cell suspension of strain ARK-1 before planting in the field, the number of plants with tumors was reduced. The results from seven field trials from 2009 to 2012 were combined in a meta-analysis. The integrated relative risk after treatment with ARK-1 was 0.15 (95% confidence interval: 0.07–0.29, P

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

    Directory of Open Access Journals (Sweden)

    Elsayed B. Belal

    2013-11-01

    Full Text Available The amount of chemosynthetic plastic waste increases every year and exact time for its degradation is unknown. Two poly &beta-Hydroxybutyric producing bacteria from different microbial sources were isolated and characterized for their morphological, biochemical properties. Based on their 16S rDNA, they were identified as Rhizobium elti E1 and Pseudomonas stutzeri E114. The bacterial strains were screened for PHB production and compared for the intensity of fluorescence using Nile red staining methods. PHB production conditions were optimized with different carbon and nitrogen sources, the highest PHB production was observed with mannitol, sucrose and ammonium sulphate by R. elti and P. stutzeri, respectively. Regarding incubation time as well as temperature and pH, optimum PHB production conditions were 48 h, 30?C and 7, respectively. R. elti P. stutzeri are capable of accumulating appreciable levels of PHB from glucose, xylose, lactose, whey, molasses, sugar cane bagasse, rice straw hydroysate when 2% from all substrates were used an alternative carbon for the PHB production. Ammonium sulphate was the best nitrogen source. C/N ratio was also one of the factors that affected the production of PHB. The ratio of C/N that reaches 20:1 was considered the best ratio to produce the highest production of PHB. The highest yield of PHB was done by P. stutzeri more than R. elti. The present study provide the useful data about the optimized conditions for PHB production by R. elti and P. stutzeri that can be utilized for industrial production of PHB, a fast emerging alternative of non biodegradable plastics.

  6. Competition among rhizobium species for nodulation of Leucaena leucocephala in two tropical soils

    Energy Technology Data Exchange (ETDEWEB)

    Moawad, H.; Bohlool, B.B.

    1984-07-01

    The successful nodulation of legumes by a Rhizobium strain is determined by the competitve ability of that strain against the mixture of other native and inoculant rhizobia. Competition among six Leucaena rhizobial strains in single and multistrain inoculants were studied. Field inoculation trials were conducted in an oxisol and a mollisol soil, both of which contained indigenous Leucaena-nodulating rhizobia. Strain-specific fluorescent antibodies were used for the identification of the strains in Leucaena nodules. Mixtures of three recommended inoculum strains for Leucaena species (TAL82, TAL582, and TAL1145) were used in peat-based inocula either alone or with one of the three other strains isolated from the sites, B213, B214, and B215. Each of these latter three strains was also used as single-strain inocula to study their competition with the native rhizobia in the two soil systems. In the oxisol soil, strains B213 and B215, when used as single-strain inocula, outcompeted the native rhizobia and formed 92 and 62% of the nodules, respectively. Strain B214 was the least competitive in oxisol soil, where it formed 30% of the nodules, and the best in mollisol soil, where it formed 70% of the nodules. The most successful competitor for nodulation in multistrain inocula was strain TAL1145, which outcompeted native and other inoculum Leucaena rhizobia is both soils. None of the strains in single or multistrain inoculants was capable of completely overcoming the resident rhizobia, which formed 4 to 70% of the total nodules in oxisol soil and 12 to 72% in mollisol soil. No strong relationship was detected between the size of the rhizosphere population of a strain and its successful occupation of nodules. 24 references.

  7. Identification of protein secretion systems and novel secreted proteins in Rhizobium leguminosarum bv. viciae

    Directory of Open Access Journals (Sweden)

    Krehenbrink Martin

    2008-01-01

    Full Text Available Abstract Background Proteins secreted by bacteria play an important role in infection of eukaryotic hosts. Rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. Proteins secreted during the infection process by some rhizobial strains can influence infection and modify the plant defence signalling pathways. The aim of this study was to systematically analyse protein secretion in the recently sequenced strain Rhizobium leguminosarum bv. viciae 3841. Results Similarity searches using defined protein secretion systems from other Gram-negative bacteria as query sequences revealed that R. l. bv. viciae 3841 has ten putative protein secretion systems. These are the general export pathway (GEP, a twin-arginine translocase (TAT secretion system, four separate Type I systems, one putative Type IV system and three Type V autotransporters. Mutations in genes encoding each of these (except the GEP were generated, but only mutations affecting the PrsDE (Type I and TAT systems were observed to affect the growth phenotype and the profile of proteins in the culture supernatant. Bioinformatic analysis and mass fingerprinting of tryptic fragments of culture supernatant proteins identified 14 putative Type I substrates, 12 of which are secreted via the PrsDE, secretion system. The TAT mutant was defective for the symbiosis, forming nodules incapable of nitrogen fixation. Conclusion None of the R. l. bv. viciae 3841 protein secretion systems putatively involved in the secretion of proteins to the extracellular space (Type I, Type IV, Type V is required for establishing the symbiosis with legumes. The PrsDE (Type I system was shown to be the major route of protein secretion in non-symbiotic cells and to secrete proteins of widely varied size and predicted function. This is in contrast to many Type I systems from other bacteria, which typically secrete specific substrates encoded by genes often localised in close proximity to the genes encoding the secretion system itself.

  8. Proteomic profiling of Rhizobium tropici PRF 81: identification of conserved and specific responses to heat stress

    Directory of Open Access Journals (Sweden)

    Gomes Douglas

    2012-05-01

    Full Text Available Abstract Background Rhizobium tropici strain PRF 81 (= SEMIA 4080 has been used in commercial inoculants for application to common-bean crops in Brazil since 1998, due to its high efficiency in fixing nitrogen, competitiveness against indigenous rhizobial populations and capacity to adapt to stressful tropical conditions, representing a key alternative to application of N-fertilizers. The objective of our study was to obtain an overview of adaptive responses to heat stress of strain PRF 81, by analyzing differentially expressed proteins when the bacterium is grown at 28°C and 35°C. Results Two-dimensional gel electrophoresis (2DE revealed up-regulation of fifty-nine spots that were identified by MALDI-TOF/TOF-TOF. Differentially expressed proteins were associated with the functional COG categories of metabolism, cellular processes and signaling, information storage and processing. Among the up-regulated proteins, we found some related to conserved heat responses, such as molecular chaperones DnaK and GroEL, and other related proteins, such as translation factors EF-Tu, EF-G, EF-Ts and IF2. Interestingly, several oxidative stress-responsive proteins were also up-regulated, and these results reveal the diversity of adaptation mechanisms presented by this thermotolerant strain, suggesting a cross-talk between heat and oxidative stresses. Conclusions Our data provide valuable protein-expression information relevant to the ongoing genome sequencing of strain PRF 81, and contributes to our still-poor knowledge of the molecular determinants of the thermotolerance exhibited by R. tropici species.

  9. Optimización de las condiciones de fermentación para la producción de polihidroxibutirato por Rhizobium tropici

    Directory of Open Access Journals (Sweden)

    Yuliet Franco

    2009-01-01

    Full Text Available Los polihidroxialcanoatos (PHAs, son poliésteres acumulados intracelularmente como materiales de reserva de carbono y energía por varios microorganismos. El representante más común de esta familia es el poli-b-hidroxibutirato (PHB. Estos biopolímeros se consideran buenos sustitutos de los plásticos sintéticos derivados del petróleo por ser biodregadrables. Sin embargo, la mayor desventaja para la comercialización de los PHA son sus elevados costos de producción comparados con los plásticos derivados del petróleo. La optimización del proceso de fermentación, es una de las estrategias más utilizadas para reducir estos costos. Este trabajo tuvo como objetivos determinar el valor óptimo de pH inicial de la fermentación para la producción de PHB, así como optimizar las condiciones de agitación y aeración del proceso para el rendimiento producto biomasa y para la acumulación de PHB por la cepa Rhizobium tropici 3. La optimización del pH inicial se realizó en zaranda orbital ajustando el valor entre 6 y 8 y se modeló la relación entre el pH y la concentración de PHB (g · L-1 mediante la utilización de polinomios ortogonales. Se definió que el pH inicial óptimo con el cual se asegura la mayor producción de PHB es 6,58 ± 0,2. La búsqueda de los valores óptimos de agitación-aeración para la producción de PHB y para el rendimiento producto-biomasa, se realizó mediante el empleo de un diseño central compuesto Box-Wilson. Las fermentaciones se realizaron en un fermentador de 7,5 L con 5 L de medio de cultivo optimizado. Se determinó que los valores óptimos para la producción fueron 500 r · min-1 y 1 vvm (volumen de aire por minuto por volumen de medio de cultivo para la agitación y la aeración respectivamente y para el rendimiento producto-biomasa, los valores óptimos fueron 472 r · min-1 y 1,55 vvm.

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

    Science.gov (United States)

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

    2015-01-01

    Pseudomonas sp. strain YS-1p and Rhizobium sp. strain YS-1r were isolated from a lignin-degrading enrichment culture. The isolates degraded lignin-derived monomers, dimers, alkali lignin, and, to a smaller extent (3% to 5%), lignin in switch grass and alfalfa. Genome analysis revealed the presence of a variety of lignin-degrading genes. PMID:25744986

  11. Roles of flagella, lipopolysaccharide, and a Ca2+-dependent cell surface protein in attachment of Rhizobium leguminosarum biovar viciae to pea root hair tips.

    OpenAIRE

    Smit, G.; Kijne, J. W.; Lugtenberg, B. J.

    1989-01-01

    The relationship between Ca2+-dependent cell surface components of Rhizobium leguminosarum biovar viciae, motility, and ability to attach to pea root hair tips was investigated. In contrast to flagella and lipopolysaccharide, a small protein located on the cell surface was identified as the Ca2+-dependent adhesin.

  12. Une fosse du Bronze final IIb dans le Val d’Orléans à Sandillon (Loiret : données archéologiques et contexte environnemental A Late Bronze Age pit IIb in the Val d’Orléans at Sandillon (Loiret: archaeological data and environmental context

    Directory of Open Access Journals (Sweden)

    Hélène Froquet

    2008-06-01

    Full Text Available Un diagnostic archéologique réalisé en 2004 à Sandillon (Loiret a permis la découverte d’une occupation du Bronze final IIb dans la plaine alluviale de la Loire. Les structures sont peu nombreuses, mais une fosse se distingue par un ensemble céramique exceptionnel par sa richesse, sa conservation et la présence de formes encore inconnues en région Centre. Ce corpus céramique, corrélé par une datation par radiocarbone, offre désormais un jalon fiable pour la région. Par ailleurs, ces vestiges ont pu être replacés dans leur environnement immédiat grâce à une étude géomorphologique et à l’analyse des restes carpologiques contenus dans la fosse. Ainsi, le croisement des données permet de tenter une approche paléo environnementale sur une occupation en contexte fluviatile et de préciser les relations entre l’homme et son milieu durant cette période chronologique.An archaeological diagnostic carried out in 2004 at Sandillon (Loiret enabled the discovery of a final Bronze Age IIb occupation in the alluvial Loire valley. There are few structures but one pit is noteworthy for a ceramic collection, exceptional in its abundance, its preservation and the presence of previously unknown forms in the Centre region. This ceramic corpus, dated by radiocarbon, henceforth provides a reliable standard for the region. Moreover, these relics could be set in their immediate environment thanks to a geomorphological study and to the analysis of carpological remains contained in the pit. So, the crossing of data allows us to attempt an environmental paleolithic approach to an occupation in a freshwater context and to clarify the relationship between man and his environment in this chronological period.

  13. Canonical and non-canonical EcfG sigma factors control the general stress response in Rhizobium etli

    OpenAIRE

    Jans, Ann; Vercruysse, Maarten; Gao, Shanjun; Engelen, Kristof; Lambrichts, Ivo; Fauvart, Maarten; Michiels, Jan

    2013-01-01

    A core component of the ?-proteobacterial general stress response (GSR) is the extracytoplasmic function (ECF) sigma factor EcfG, exclusively present in this taxonomic class. Half of the completed ?-proteobacterial genome sequences contain two or more copies of genes encoding ?EcfG-like sigma factors, with the primary copy typically located adjacent to genes coding for a cognate anti-sigma factor (NepR) and two-component response regulator (PhyR). So far, the widespread occurrence of addit...

  14. Genetic Factors in Rhizobium Affecting the Symbiotic Carbon Costs of N2 Fixation and Host Plant Biomass Production

    DEFF Research Database (Denmark)

    SkØt, L.; Hirsch, P. R.

    1986-01-01

    The effect of genetic factors in Rhizobium on host plant biomass production and on the carbon costs of N2 fixation in pea root nodules was studied. Nine strains of Rhizobium leguminosarum were constructed, each containing one of three symbiotic plasmids in combination with one of three different genomic backgrounds. The resulting strains were tested in symbiosis with plants of Pisum sativum using a flow-through apparatus in which nodule nitrogenase activity and respiration were measured simultaneously under steady state conditions. Nodules formed by strains containing the background of JI6015 had the lowest carbon costs of N2 fixation (7.10–8.10 ?mol C/?mol N2), but shoot dry weight of those plants was also smaller than that of plants nodulated by strains with the background of B151 or JI8400. Nodules formed by these two strain types had carbon costs of N2 fixation varying between 11.26 and 13.95 ?mol C/?mol N2. The effect of symbiotic plasmids on the carbon costs was relatively small. A time-course experiment demonstrated that nodules formed by a strain derived from JI6015 were delayed in the onset of nitrogenase activity and had a lower rate of activity compared to nodules induced by a strain with the background of B151. The relationship between nitrogenase activity, carbon costs of N2 fixation and host plant biomass production is discussed.

  15. Identification and characterization of the Rhizobium sp. strain GIN611 glycoside oxidoreductase resulting in the deglycosylation of ginsenosides.

    Science.gov (United States)

    Kim, Eun-Mi; Kim, Juhan; Seo, Joo-Hyun; Park, Jun-Seong; Kim, Duck-Hee; Kim, Byung-Gee

    2012-01-01

    Using enrichment culture, Rhizobium sp. strain GIN611 was isolated as having activity for deglycosylation of a ginsenoside, compound K (CK). The purified heterodimeric protein complex from Rhizobium sp. GIN611 consisted of two subunits with molecular masses of 63.5 kDa and 17.5 kDa. In the genome, the coding sequence for the small subunit was located right after the sequence for the large subunit, with one nucleotide overlapping. The large subunit showed CK oxidation activity, and the deglycosylation of compound K was performed via oxidation of ginsenoside glucose by glycoside oxidoreductase. Coexpression of the small subunit helped soluble expression of the large subunit in recombinant Escherichia coli. The purified large subunit also showed oxidation activity against other ginsenoside compounds, such as Rb1, Rb2, Rb3, Rc, F2, CK, Rh2, Re, F1, and the isoflavone daidzin, but at a much lower rate. When oxidized CK was extracted and incubated in phosphate buffer with or without enzyme, (S)-protopanaxadiol [PPD(S)] was detected in both cases, which suggests that deglycosylation of oxidized glucose is spontaneous. PMID:22020506

  16. Role of cellulose fibrils and exopolysaccharides of Rhizobium leguminosarum in attachment to and infection of Vicia sativa root hairs.

    Science.gov (United States)

    Laus, M C; van Brussel, A A N; Kijne, J W

    2005-06-01

    Infection and subsequent nodulation of legume host plants by the root nodule symbiote Rhizobium leguminosarum usually require attachment of the bacteria to root-hair tips. Bacterial cellulose fibrils have been shown to be involved in this attachment process but appeared not to be essential for successful nodulation. Detailed analysis of Vicia sativa root-hair infection by wild-type Rhizobium leguminosarum RBL5523 and its cellulose fibril-deficient celE mutant showed that wild-type bacteria infected elongated growing root hairs, whereas cellulose-deficient bacteria infected young emerging root hairs. Exopolysaccharide-deficient strains that retained the ability to produce cellulose fibrils could also infect elongated root hairs but infection thread colonization was defective. Cellulose-mediated agglutination of these bacteria in the root-hair curl appeared to prevent entry into the induced infection thread. Infection experiments with V sativa roots and an extracellular polysaccharide (EPS)- and cellulose-deficient double mutant showed that cellulose-mediated agglutination of the EPS-deficient bacteria in the infection thread was now abolished and that infection thread colonization was partially restored. Interestingly, in this case, infection threads were initiated in root hairs that originated from the cortical cell layers of the root and not in epidermal root hairs. Apparently, surface polysaccharides of R. leguminosarum, such as cellulose fibrils, are determining factors for infection of different developmental stages of root hairs. PMID:15986922

  17. Intensity of Ground Cover Crop Arachis pintoi, Rhizobium Inoculation and Phosphorus Application and Their Effects on Field Growth and Nutrient Status of Cocoa Plants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2006-08-01

    Full Text Available Arachis pintoiis potentially as a cover crop for cocoa (Theobroma cacaoL. farm, however information regarding its effect on the growth of cocoa plants in the field is very limited. The objective of this experiment is to investigate the combined influence of ground cover crop A. pintoi, rhizobial bacterial inoculation and phosphorus (P fertilizer on the growth of cocoa in the field and nutrient status. This experiment laid out in split-split plot design consisted of three levels of cover crop (without, A. pintoiand Calopogonium caeruleum, two levels of rhizobium inoculation (not inoculated and inoculated and two levels of phosphorus application (no P added and P added. The results showed that in field condition the presence of A. pintoias cover crop did not affect the growth of cocoa. On the other hand, C. caeruleumas cover crop tended to restrict cocoa growth compared to A. pintoi. Application of P increased leaf number of cocoa plant. Biomass production of A. pintoiwas 40% higher than C. caeruleum. Soil organic carbon and nitrogen contents were not affected by ground cover crops, though higher value (0.235% N and 1.63% organic C was obtained from combined treatments of inoculation and P addition or neither inoculation nor P addition. In the case of no rhizobium inoculation, soil N content in cocoa farm with A. pintoicover crop was lower than that of without cover crop or with C. caeruleum. Cover crop increased plant N content when there was no inoculation, on the other hand rhizobium inoculation decreased N content of cocoa tissue. Tissue P content of cocoa plant was not influenced by A. Pintoicover crop or by rhizobium inoculation, except that the P tissue content of cocoa was 28% higher when the cover crop was C. caeruleumand inoculated. Key words : Arachis pintoi, Theobroma cacao, Calopogonium caeruleum, rhizobium, nitrogen, phosphorus.

  18. Respuesta de combinaciones Rhizobium - Clitoria ternatea en condiciones de estrés salino en el Valle del Cauto en Cuba / Response of Rhizobium - Clitoria ternatea combinations under salt stress in the Cauto Valley in Cuba

    Scientific Electronic Library Online (English)

    Raúl Carlos, López Sánchez; Roeland, Samson; Patrick, Vandamme; Bettina, Eichler-Löbermann; Ernesto, Gómez Padilla.

    2011-06-01

    Full Text Available Se estudió la respuesta de Clitoria ternatea en condiciones de estrés salino a la inoculación con aislamientos nativos y cepas comerciales de rizobios. El estudio se realizó en condiciones de invernadero y de campo. El efecto de tres cepas de rizobio (Jd19, 1031 y 1032) en el rendimiento y parámetro [...] s de la fijación de nitrógeno se comparó con el testigo y el tratamiento con fertilización nitrogenada. En el experimento en invernadero los mejores resultados para el rendimiento y parámetros de fijación de nitrógeno se encuentran con el aislamiento nativo de rizobio Jd19. En este tratamiento se encontraron los valores más altos de peso seco de masa aérea y raíces y de acumulación de nitrógeno. Además en el tratamiento con el aislamiento Jd19 se mostraron los valores más altos de relación K:Na, contenido de ureidos, clorofila a y b en el tallo y el mejor índice de efectividad de la inoculación. En el experimento de campo el tratamiento con el aislamiento Jd19 tuvo el mejor efecto positivo en comparación con el resto de los tratamientos. Los resultados indican que la combinación Clitoria ternatea-Jd19 es más eficiente en condiciones de estrés salino, y es posible su introducción a amplia escala en suelos afectados por la salinidad. Abstract in english The purpose of the present study was to examine response of Clitoria tarnatea under salt stress to inoculation with native isolates and commercial strains of Rhizobium. This study was carried out both in greenhouse and field conditions. Effects of three Rhizobium strains (Jd19, 1031 and 1032) were c [...] ompared to control and mineral N fertilization regarding yield and nitrogen fixation parameters. In the greenhouse experiment the best results for yield and nitrogen fixation parameters were found for the Jd19 native isolate treatment, where the highest dry weight of both shoots and roots and also of nitrogen uptake were observed. Besides, this treatment showed the highest K:Na ratio, as well as of contents of ureides, of a and b chlorophyll in stem and the best inoculation effectiveness index. In the field test, the Jd19 treatment showed the best positive effect in comparison to the other treatments. Results indicate that the Clitoria ternatea-Jd19 Rhizobium strain combination is the most efficient under salt stress and also that its wide scale introduction in saline soils is possible.

  19. Propriedades reológicas e efeito da adição de sal na viscosidade de exopolissacarídeos produzidos por bactérias do gênero Rhizobium / Rheological properties and effect of the salt addition on the exopolysaccharides viscosity produced by bacteria of Rhizobium genus

    Scientific Electronic Library Online (English)

    Gabriel, Aranda-Selverio; Ana Lúcia Barretto, Penna; Luciana Frizarin, Campos-Sás; Osvaldo dos, Santos Junior; Ana Flora Dalberto, Vasconcelos; Maria de Lourdes Corradi da, Silva; Eliana Gertrudes Macedo, Lemos; João Carlos, Campanharo; Joana Léa Meira, Silveira.

    Full Text Available [...] Abstract in english Viscosity of some polysaccharide solutions supports that these molecules can be applied in food sectors. Four exopolysaccharides (R1, R2, R3, R4) produced by different Rhizobium strains were selected. Sugar composition and differences in the uronic acid contents suggests that chemical structure of t [...] hese molecules can vary when different culture conditions and strains are analyzed. The Power Law was the rheological model used to represent the experimental data of shear stress versus shear rate. All exopolysaccharides showed non-Newtonian behavior, with pseudoplastic characteristics. R1, R2 and R4 showed a slight increase in viscosity in the presence of 0,2 M NaCl.

  20. AVALIAÇÃO DA FIXAÇÃO BIOLÓGICA DO NITROGÊNIO EM GENÓTIPOS DE FEIJOEIROS TOLERANTES A SECA EVALUATION OF BIOLOGICAL FIXATION OF NITROGEN IN RHIZOBIUM UNDER WATER DEFICIT

    Directory of Open Access Journals (Sweden)

    Willian Bucker Moraes

    2010-04-01

    Full Text Available Vários fatores como a temperatura, acidez do solo, teor de nutrientes e cultivar, interferem na eficiência simbiótica das estirpes de Rhizobium em condições de campo. Com objetivo de avaliar a capacidade de fixação biológica de nitrogênio de estirpes nativas de Rhizobium sp. foi realizado um experimento em vasos montado no delineamento inteiramente casualizado no esquema fatorial 10x7 (10 linhagens de feijoeiro consideradas tolerantes ao déficit hídrico, sendo estas: Amarelinho, Macuquinho, Imperial, EL 22, BATT 477, Uirapuru, IAPAR-81, Bate Estrada, Serrano e Preto Meia Lua e 7 inoculantes isolados dos solos dos municipios de Colatina, Vila Pavão, Nova Venécia, Pinheiros, Sooretama, Linhares e Alegre, no estado do Espírito Santo, com quatro repetições. Os dados demonstraram que a fixação biológica de N2 utilizando a inoculação de estirpes eficientes de Rhizobium em cultivar nodulante de feijoeiro ou seu cultivo em solos com população nativa eficiente, pode possibilitar a suplementação ou até mesmo á não utilização de nitrogênio em cobertura na cultura do feijoeiro, sem perdas no rendimento da produtividade.Several factors as the temperature, soil acidity, content of nutrients and cultivate interfere in the symbiotic efficiency of the ancestries of Rhizobium infield conditions. With the objective of evaluating the capacity of biological fixation of nitrogen of native ancestries of Rhizobium sp. an experiment was accomplished in vases set up in the delineate entirely casualty in the factorial outline 10x7 (10 bean plant lineages considered tolerant to the water deficit, being these: Amarelinho, Macuquinho, Imperial, EL 22, BATT 477, Uirapuru, IAPAR-81, Bate Estrada, Serrano and Preto Meia Lua and 7 isolated inoculate of the soils of the municipal districts of Colatina, Vila Pavão, Nova Venécia, Pinheiros, Sooretama, Linhares and Alegre in Espírito Saint state, with four repetitions. The data demonstrated that the biological fixation of N2 using the inoculation of efficient ancestries of Rhizobium in cultivating bean plant nodule cultivation in soils with efficient native population, it can make possible the supplement or even to the not use of nitrogen in covering in the culture bean plant, without losses in the income of the productivity.

  1. AVALIAÇÃO DA FIXAÇÃO BIOLÓGICA DO NITROGÊNIO EM GENÓTIPOS DE FEIJOEIROS TOLERANTES A SECA / EVALUATION OF BIOLOGICAL FIXATION OF NITROGEN IN RHIZOBIUM UNDER WATER DEFICIT

    Scientific Electronic Library Online (English)

    Willian, Bucker Moraes; Sebastião, Martins Filho; Giovanni de Oliveira, Garcia; Simone de Paiva, Caetano; Wanderson, Bucker Moraes; Fernando, Carrara Cosmi.

    2010-04-01

    Full Text Available Vários fatores como a temperatura, acidez do solo, teor de nutrientes e cultivar, interferem na eficiência simbiótica das estirpes de Rhizobium em condições de campo. Com objetivo de avaliar a capacidade de fixação biológica de nitrogênio de estirpes nativas de Rhizobium sp. foi realizado um experim [...] ento em vasos montado no delineamento inteiramente casualizado no esquema fatorial 10x7 (10 linhagens de feijoeiro consideradas tolerantes ao déficit hídrico, sendo estas: Amarelinho, Macuquinho, Imperial, EL 22, BATT 477, Uirapuru, IAPAR-81, Bate Estrada, Serrano e Preto Meia Lua e 7 inoculantes isolados dos solos dos municipios de Colatina, Vila Pavão, Nova Venécia, Pinheiros, Sooretama, Linhares e Alegre, no estado do Espírito Santo, com quatro repetições. Os dados demonstraram que a fixação biológica de N2 utilizando a inoculação de estirpes eficientes de Rhizobium em cultivar nodulante de feijoeiro ou seu cultivo em solos com população nativa eficiente, pode possibilitar a suplementação ou até mesmo á não utilização de nitrogênio em cobertura na cultura do feijoeiro, sem perdas no rendimento da produtividade. Abstract in english Several factors as the temperature, soil acidity, content of nutrients and cultivate interfere in the symbiotic efficiency of the ancestries of Rhizobium infield conditions. With the objective of evaluating the capacity of biological fixation of nitrogen of native ancestries of Rhizobium sp. an expe [...] riment was accomplished in vases set up in the delineate entirely casualty in the factorial outline 10x7 (10 bean plant lineages considered tolerant to the water deficit, being these: Amarelinho, Macuquinho, Imperial, EL 22, BATT 477, Uirapuru, IAPAR-81, Bate Estrada, Serrano and Preto Meia Lua and 7 isolated inoculate of the soils of the municipal districts of Colatina, Vila Pavão, Nova Venécia, Pinheiros, Sooretama, Linhares and Alegre in Espírito Saint state, with four repetitions. The data demonstrated that the biological fixation of N2 using the inoculation of efficient ancestries of Rhizobium in cultivating bean plant nodule cultivation in soils with efficient native population, it can make possible the supplement or even to the not use of nitrogen in covering in the culture bean plant, without losses in the income of the productivity.

  2. Mechanisms of protection of pea plants by polysaccharides extracted from a strain of Rhizobium against Orobanche crenata

    International Nuclear Information System (INIS)

    The Broomrape causes notable damage on the leguminous crops and became major factor limiting production of pea in the Mediterranean region. The effect of the polysaccharides extracted from P.SOM Rhizobium strain on the development of Orobanche crenata on pea was studied. The results showed that the lipopolysaccharides significantly reduce the infestation of pea by O. crenata. This limitation of infestation results from the reduction of seeds germination rates of the parasite resulting in reduction of the tubercles number on pea roots. Moreover, necrosis of orobanche before or after attachment on pea roots treated by LPS can explain this reduction of parasitism. A correlation was observed between the reduction of pea infection by the broomrape and the activation phenolic compounds pathway. This activation resulted to increase of two enzymes (peroxidase and polyphenoloxidase) activities these enzymes are implicated in plant defense. The results of our study showed that the LPS seem implied in the induction of pea resistance against the broomrape.

  3. Extracellular polysaccharides are involved in the attachment of Azospirillum brasilense and Rhizobium leguminosarum to arbuscular mycorrhizal structures

    Directory of Open Access Journals (Sweden)

    V Bianciotto

    2009-12-01

    Full Text Available Arbuscular mycorrhizal (AM fungi, one of the most important component of the soil microbial community, establish physical interactions with naturally occurring and genetically modified bacterial biofertilizers and biopesticides, commonly referred to as plant growth-promoting rhizobacteria (PGPR. We have used a genetic approach to investigate the bacterial components possibly involved in the attachment of two PGPR (Azospirillum and Rhizobium to AM roots and AM fungal structures. Mutants affected in extracellular polysaccharides (EPS have been tested in in vitro adhesion assays and shown to be strongly impaired in the attachment to both types of surfaces as well as to quartz fibers. Anchoring of rhizobacteria to AM fungal structures may have special ecological and biotechnological significance because it may facilitate colonisation of new rhizospheres by the bacteria, and may be an essential trait for the development of mixed inocula.

  4. Effect of Rhizobium and arbuscular mycorrhizal fungi inoculation on electrolyte leakage in Phaseolus vulgaris roots overexpressing RbohB.

    Science.gov (United States)

    Arthikala, Manoj-Kumar; Nava, Noreide; Quinto, Carmen

    2015-04-01

    Respiratory oxidative burst homolog (RBOH)-mediated reactive oxygen species (ROS) regulate a wide range of biological functions in plants. They play a critical role in the symbiosis between legumes and nitrogen-fixing bacteria or arbuscular mycorrhizal (AM) fungi. For instance, overexpression of PvRbohB enhances nodule numbers, but reduces mycorrhizal colonization in Phaseolus vulgaris hairy roots and downregulation has the opposite effect. In the present study, we assessed the effect of both rhizobia and AM fungi on electrolyte leakage in transgenic P. vulgaris roots overexpressing (OE) PvRbohB. We demonstrate that elevated levels of electrolyte leakage in uninoculated PvRbohB-OE transgenic roots were alleviated by either Rhizobium or AM fungi symbiosis, with the latter interaction having the greater effect. These results suggest that symbiont colonization reduces ROS elevated electrolyte leakage in P. vulgaris root cells. PMID:25946118

  5. In vitro Survival and Nematicidal Activity of Rhizobium, Bradyrhizobium and Sinorhizobium. I. The Influence of Various NaCl Concentrations

    Directory of Open Access Journals (Sweden)

    S. Shahid Shaukat

    2002-01-01

    Full Text Available During the survey of the cultivated fields in Karachi and neighborhood (Southern Sindh, 3 strains of Rhizobium phaseoli, 1 strain of R. leguminosarum and R. trifolii each, 5 strains of Sinorhizobium meliloti, 2 strains of Bradyrhizobium japonicum and 3 strains of Bradyrhizobium sp. were isolated and identified. The 15 strains of rhizobia tested for their growth under saline media exhibited varying degree of effects to salt concentrations. Most resistant strain was that of S. meliloti MAT1(R9 while least resistant was that of Bradyrhizobium sp. VRM1(R13. All the rhizobial strains caused significant mortality of Meloidogyne incognita, the root-knot nematode juveniles in vitro, though the strains differed markedly in their toxic activity. The rhizobial strains showed significant interaction with NaCl salinity towards M. incognita

  6. Response of lupine plants irrigated with saline water to rhizobium inoculation using 15N-isotope dilution

    International Nuclear Information System (INIS)

    The lupine Rhizobium symbiosis and contribution of N2 fixation under different levels of irrigation water salinity were examined. Lysimeter experiment was established under greenhouse conditions during the year 2002-2003. In this experiment, inoculated plants were imposed to different salinity levels of irrigation water and N-fertilizer treatment. Plant height was decreased under different salinity levels, nitrogen treatments and bacterial inoculation. Similar trend was noticed with leaf area. The highest leaf area was recorded with salt tolerant bacterial inoculation (SBI) and splitting N-treatment. Highest values of N-uptake occurred after 100 day intervals under the tested factors. Relative decrease in N-uptake did not exceed 40% of those recorded with the fresh water treatment as affected by experimental factors. Nitrogen uptake by the whole plant reflected an increase at 3 dS/m salinity level of irrigation water. Relative increases were 5% and 15% for normal bacteria inoculation under single dose (NI) and splitting

  7. Nickel detoxification and plant growth promotion by multi metal resistant plant growth promoting Rhizobium species RL9.

    Science.gov (United States)

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2013-07-01

    Pollution of the biosphere by heavy metals is a global threat that has accelerated dramatically since the beginning of industrial revolution. The aim of the study is to check the resistance of RL9 towards the metals and to observe the effect of Rhizobium species on growth, pigment content, protein and nickel uptake by lentil in the presence and absence of nickel. The multi metal tolerant and plant growth promoting Rhizobium strain RL9 was isolated from the nodules of lentil. The strain not only tolerated nickel but was also tolerant o cadmium, chromium, nickel, lead, zinc and copper. The strain tolerated nickel 500 ?g/mL, cadmium 300 ?g/mL, chromium 400 ?g/mL, lead 1,400 ?g/mL, zinc 1,000 ?g/mL and copper 300 ?g/mL, produced good amount of indole acetic acid and was also positive for siderophore, hydrogen cyanide and ammonia. The strain RL9 was further assessed with increasing concentrations of nickel when lentil was used as a test crop. The strain RL9 significantly increased growth, nodulation, chlorophyll, leghaemoglobin, nitrogen content, seed protein and seed yield compared to plants grown in the absence of bioinoculant but amended with nickel The strain RL9 decreased uptake of nickel in lentil compared to plants grown in the absence of bio-inoculant. Due to these intrinsic abilities strain RL9 could be utilized for growth promotion as well as for the remediation of nickel in nickel contaminated soil. PMID:23609454

  8. Improvement of Canola (Brassica napus L.) Inoculated with Rhizobium, Azospirillum and/or Mycorrhizal Fungi Under Salinity Stress

    International Nuclear Information System (INIS)

    Bio fertilization technology was applied for improving canola plant growth and nutrient acquisition in sandy saline soil ,as a biological mean used to develop plant growth and nutrient uptake under salinity stress. Canola was cultivated in pots packed at rate of 7 kg saline sandy soil pot-1, and inoculated with Rhizobium leguminosarum biovar viceae, Azospirillum brasilense strain no. 40 and arbuscular mycorrhizal fungi either solely or in combinations of them. Nitrogen fertilizer was added in form (15NH4)2SO4 with 5%15N atom excess at rate of 0.99 g N pot-1. Maximum dry matter accumulation induced by composite inoculation (Rh + Azo + AM). Na concentrations were frequently affected by Rhizobium and /or mycorrhizae while K was affected by Azospirillum and /or mycorrhizae. Azospirillum enhanced Ca uptake whereas Mg content was responded well to composite inoculants of Rh + Azo + AM. Dual inoculation with Rh + Azo resulted in the highest values of N uptake by plant. Similar effect was noticed with P uptake when dual inoculums of Azo + AM were applied. Data of 15N isotope showed that the highest portion and value of N2-fixed was recorded with composite inoculums followed by dual inoculations. On the other hand, the infection with AM fungi gave the highest proportion of N derived from fertilizer as compared to other inoculants or uninoculated control. In the same trend, the feculated control. In the same trend, the fertilizer use efficiency (FUE%) was enhanced by AM infection. Dual inoculums of Rh + Azo induced highest content of proline in leaves. (Authors)

  9. Impact of dual inoculation with Rhizobium and PGPR on growth and antioxidant status of Vicia faba L. under copper stress.

    Science.gov (United States)

    Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez; Jebara, Salwa Harzalli

    2015-04-01

    Plant-growth-promoting bacteria (PGPR) may help reduce the toxicity of heavy metals in plants in polluted environments. In this work, the effects of dual inoculation with Rhizobium and PGPR strains on the growth of Vicia faba grown under copper stress were assessed during hydroponic culture. Growth parameters, copper (Cu) accumulation and antioxidant enzyme activities were studied. Copper concentrations above 1mM damaged plant growth, but co-inoculation reduced its harmful effect. Co-inoculation of plants treated with 1mM Cu and 2mM Cu increased the dry weights as compared with Cu-treated and uninoculated plants. However, it decreased copper uptake up to 80% in the roots of 1-mM-Cu-treated plants as compared to non-inoculated control. Copper tolerance in Vicia faba is linked to the activity of antioxidant systems that are modulated by metal concentrations: both superoxide dismutase (SOD) and catalase (CAT) were higher in the presence of Cu; a lower Cu dose of 0.5mM stimulated ascorbate peroxidase (APX) and/or peroxidase (POX) activities in shoots and roots; however in nodules CAT appeared to be the main peroxidase in H2O2 scavenging. The 1mM Cu treatment enhanced SOD, CAT and APX activities in roots and only SOD and POX were activated in shoots. All enzyme activities were inhibited by inoculation of 2mM Cu. The effect of inoculation with copper-accumulating PGPRs and the status of the antioxidant enzyme system were linked to changes in the copper tolerance status of Vicia faba. Our results suggested that Vicia faba inoculation with Rhizobium and PGPR Enterobacter clocae and Pseudomonas sp. could help to alleviate copper stress under hydroponic conditions. This result should be tested under field conditions for soil fertilization and phytostabilisation purposes. PMID:25747267

  10. Evolución del tamaño y del peso del fruto de kiwi (Actinidia deliciosa (A. Chev.) Liang et Fergurson) cultivar "Hayward" durante la etapa final de crecimiento / Evolution of the size and weight of "Hayward" kiwifruit (Actinidia deliciosa (A. Chev.) Liang et Fergurson) cultivar during the final stage of growth

    Scientific Electronic Library Online (English)

    Mónica G, Ontivero Urquiza; Héctor Abel, Altube; Leonardo, Baghin.

    2012-12-01

    Full Text Available Se realizó un ensayo durante tres años consecutivos con el fin de monitorear la evolución del tamaño y del peso de los frutos de una plantación comercial de kiwi variedad Hayward ubicada en la provincia de Córdoba. El objetivo fue determinar la evolución del peso y del tamaño del fruto durante la et [...] apa final de crecimiento. Se seleccionaron doce plantas representativas y se realizaron cosechas durante cuatro semanas en tres años sucesivos desde el 4/3 al 24/3, a partir de que los frutos alcanzaron 5° Brix. Las variables evaluadas fueron: peso del fruto, longitud del fruto, diámetro mayor y menor al momento de la cosecha y luego de seis días a temperatura ambiente. El peso del fruto se incrementó desde un valor mínimo de 83,71 g a 121,1 g. La pérdida de peso luego de seis días fue desde un mínimo de 3,11 g a un máximo de 6,01 g. La longitud pasó de 54,73 mm a 64,20 mm. El diámetro mayor pasó de 52,12 mm a 59,7 mm, presentando una disminución después de seis días de un mínimo de 0,27 mm a un máximo 7,12 mm. El diámetro menor pasó de 42 mm a 54,41 mm entre la primera y la cuarta cosecha. Todas las variables presentaron un incremento en la medida en que atrasaba la cosecha, lo que justifica una cosecha más tardía, en función del tamaño de los frutos. Abstract in english A follow-up trial of the evolution of fruit size and fruit weight of a "Hayward" kiwifruit cultivar was conducted in a commercial plantation in the province of Córdoba during three consecutive years. Twelve representative plants were selected and kiwifruit were harvested during three consecutive yea [...] rs, during four weeks, from March 4th to March 24th, when they reached 5° Brix. The examined variables were fruit weight, fruit length, major diameter and minor diameter of the fruit at the moment of harvest and after six days at room temperature. Fruit weight increased from a minimum value of 83.71 g to 121.1 g. After six days, the weight loss varied from a minimum of 3.11 g to a maximum of 6.01 g. Fruit length went from 54.73 mm to 64.20 mm. The major diameter varied from 52.12 mm to 59.7 mm presenting a decrease after six days from a minimum of 0.27 mm to a maximum of 7.12 mm. The minor diameter went from 42 mm to 54.41 mm between the first and the fourth harvest. All the variables showed an increase as the harvest was delayed, which seems to justify a later harvest considering the size of the fruit.

  11. Root colonization of different plants by plant-growth-promoting Rhizobium leguminosarum bv. trifolii R39 studied with monospecific polyclonal antisera.

    OpenAIRE

    Schloter, M.; Wiehe, W; B. Assmus; Steindl, H; Becke, H; Höflich, G; A Hartmann

    1997-01-01

    Monospecific polyclonal antisera raised against Rhizobium leguminosarum bv. trifolii R39, a bacterium which was isolated originally from red clover nodules, were used to study the colonization of roots of leguminous and nonleguminous plants (Pisum sativum, Lupinus albus, Triticúm aestivum, and Zea mays) after inoculation. Eight weeks after inoculation of soil-grown plants, between 0.1 and 1% of the total bacterial population in the rhizospheres of all inoculated plants were identified as R. l...

  12. Effects of rhizobium strains isolated from wild chickpeas on the growth and symbiotic performance of chickpeas (Cicer arietinum L.) under salt stress

    OpenAIRE

    Ö?ÜTÇÜ, Hatice; KASIMO?LU, Caner; Elkoca, Erdal

    2010-01-01

    This study was conducted in order to evaluate the symbiotic effectiveness of Rhizobium leguminosarum bv. ciceri strains isolated from perennial wild chickpeas (Cicer anatolicum) in comparison to standard bacterial culture, N application, and uninoculated control under NaCl salinity stress conditions. For this purpose, 4 strains (DN1, DN7, TN3, and TN4) were obtained from wild chickpeas. Chickpea (Cicer arietinum L.) seeds were inoculated with these strains and grown in pots containing sterile...

  13. Phenotypic variation and molecular signaling in the interaction of the rhizosphere bacteria Acidovorax sp. N35 and Rhizobium radiobacter F4 with roots

    OpenAIRE

    Li, Dan

    2011-01-01

    The aim of this doctoral thesis was to investigate the factors relevant in plant interaction of two plant growth promoting rhizobacteria (PGPR). For this, the strain Acidovorax sp. N35 isolated from surface sterilized wheat roots and the two strains F4 and F7 of Rhizobium radiobacter, a bacterium associated with the plant growth promoting fungus Piriformospora indica, were chosen. First of all, the isolate N35 was characterized using phylogenetic and taxonomic methods. The 16S rRNA gene seque...

  14. Evidence for divalent cation (Ca2+)-stabilized oligomeric proteins and covalently bound protein-peptidoglycan complexes in the outer membrane of Rhizobium leguminosarum.

    OpenAIRE

    Maagd, R. A.; Wientjes, F. B.; Lugtenberg, B. J.

    1989-01-01

    Two unusual characteristics of some outer membrane proteins of Rhizobium leguminosarum are described. First, most of the major outer membrane proteins could only be visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after lysozyme treatment of the isolated cell envelopes, suggesting a very strong, possibly covalent, interaction of these proteins with the peptidoglycan. These peptidoglycan-associated outer membrane proteins belonged to two distinct groups of immunologicall...

  15. Flavonoids induce Rhizobium leguminosarum to produce nodDABC gene-related factors that cause thick, short roots and root hair responses on common vetch.

    OpenAIRE

    Zaat, S. A.; Brussel, A. A.; Tak, T.; Pees, E.; Lugtenberg, B. J.

    1987-01-01

    Rhizobium leguminosarum produced a factor(s) that caused thick, short roots (Tsr phenotype) as well as root hair induction (Hai phenotype) and deformation (Had phenotype) in Vicia sativa plants upon incubation with root exudate or with one of the nod gene inducers naringenin or apigenin; this was a nodDABC gene-dependent process. Detection of the Hai and Had phenotypes was much more sensitive than that of the Tsr phenotype.

  16. Involvement of exo5 in Production of Surface Polysaccharides in Rhizobium leguminosarum and Its Role in Nodulation of Vicia sativa subsp. nigra

    OpenAIRE

    Laus, Marc C.; Logman, Trudy J.; Brussel, Anton A. N.; Carlson, Russell W.; Azadi, Parastoo; Gao, Mu-yun; Kijne, Jan W.

    2004-01-01

    Analysis of two exopolysaccharide-deficient mutants of Rhizobium leguminosarum, RBL5808 and RBL5812, revealed independent Tn5 transposon integrations in a single gene, designated exo5. As judged from structural and functional homology, this gene encodes a UDP-glucose dehydrogenase responsible for the oxidation of UDP-glucose to UDP-glucuronic acid. A mutation in exo5 affects all glucuronic acid-containing polysaccharides and, consequently, all galacturonic acid-containing polysaccharides. Exo...

  17. Antigenic changes in lipopolysaccharide I of Rhizobium leguminosarum bv. viciae in root nodules of Vicia sativa subsp. nigra occur during release from infection threads.

    OpenAIRE

    Goosen-de Roo, L.; Maagd, R. A.; Lugtenberg, B. J.

    1991-01-01

    Three different monoclonal antibodies raised against the O antigen-containing lipopolysaccharide (LPS I) of free-living cells were used in an immunocytochemical study to follow the fate of LPS I on the outer membrane of Rhizobium leguminosarum bv. viciae 248 during the nodulation of Vicia sativa subsp. nigra. After immunogold labeling, the LPS I epitopes were detected on the outer membrane of bacteria present in infection threads throughout the nodule. Epitopes were not detectable on bacteria...

  18. Efetividade da inoculação com rizóbio e fungos micorrízicos arbusculares em mudas de sabiá submetidas a diferentes níveis de fósforo Effectiveness of inoculation with arbuscular mycorrhizal fungi and Rhizobium sp. on Mimosa caesalpiniifolia seedlings, under different phosphorus levels

    Directory of Open Access Journals (Sweden)

    HÉLIO ALMEIDA BURITY

    2000-04-01

    Full Text Available Visando otimizar a produção de mudas de sabiá (Mimosa caesalpiniifolia Benth, foi conduzido um experimento para avaliar a efetividade da dupla inoculação com fungos micorrízicos arbusculares (FMA e rizóbio. Os tratamentos, arrumados em esquema fatorial consistiram de presença e ausência de Rhizobium sp. e de FMA (Glomus etunicatum, Acaulospora morrowae e A. longula, e de três níveis de P (0, 20 e 40 kg/ha de P2O5, na forma de superfosfato triplo. A aplicação de P na ausência e na presença dos fungos não favoreceu o desenvolvimento das plantas. As mudas com a dupla inoculação apresentaram valores significativos no crescimento, área foliar, altura das plantas, atividade da enzima nitrogenase, porcentagem de colonização radicular e outros parâmetros analisados, independentemente do nível de P usado. A nodulação do sabiá foi favorecida pela micorrização, uma vez que as mudas inoculadas apenas com Rhizobium apresentaram nodulação significativamente menor. Houve aumento da colonização micorrízica e diminuição da esporulação na presença de Rhizobium.In order to optimize Mimosa caesalpiniifolia Benth seedlings production, an experiment was carried out to evaluate the inoculation with both arbuscular mycorrhizal fungi (AMF and Rhizobium. Treatments, arranged in a factorial scheme, consisted of presence or absence of Rhizobium, and of AMF (a mixture of Glomus etunicatum, Acaulospora morrowae and A. longula, with three P levels (equivalent to 0, 20 and 40 kg/ha of P2O5, applied as triple superphosphate. The P application, in the absence or in the presence of AMF inoculation, did not enhance plant development, while the seedlings which received the double inoculation presented significant values on growth, height, leaf area, nitrogenase activity and others analyzed parameters, regardless of the P level. Mimosa caesalpiniifolia nodulation was enhanced by the inoculation with AMF, since plants which received Rhizobium alone showed significantly lower nodulation values than the ones which received both inoculations. There was an increase of the mycorrhizal and a decrease of the esporulation in the presence of Rhizobium.

  19. Final Environmental Statement related to the operation of Wolf Creek Generating Station, Unit No. 1. Docket No. STN 50-482, Kansas Gas and Electric Company, et al

    International Nuclear Information System (INIS)

    This final environmental statement contains the second assessment of the environmental impact associated with operation of Wolf Creek Generating Station Unit 1 pursuant to the National Environmental Policy Act of 1969 (NEPA) and 10 CFR Part 51, as amended, of the NRC's regulations. This statement examines: the affected environment, environmental consequences and mitigating actions, and environmental and economic benefits and costs. Land use and terrestrial- and aquatic-ecological impacts will be small. Air-quality impacts will also be small. However, steam fog from the station's cooling lake has the potential for reducing visibility over nearby roads and bridges. A fog-monitoring program for roads and bridges near the lake has been recommended. Impacts to historic and prehistoric sites will be negligible. Chemical discharges to the Neosho River are expected to have no appreciable impacts on water quality under normal conditions and will be required to meet conditions of the station's NPDES permit. The effects of routine operations, energy transmission, and periodic maintenance of rights-of-way and transmission line facilities should not jeopardize any populations of endangered or threatened species. No significant impacts are anticipated from normal operational releases of radioactivity. The risk associated with accidental radiation exposure is very low. The net socioeconomic effects of the project will be beneficial. The action called for is the issuance of an operating license for the Wolf Creek Generating Station Unit 1

  20. Rhizobium paranaense sp. nov., an effective N2-fixing symbiont of common bean (Phaseolus vulgaris L.) with broad geographical distribution in Brazil.

    Science.gov (United States)

    Dall'Agnol, Rebeca Fuzinatto; Ribeiro, Renan Augusto; Delamuta, Jakeline Renata Marçon; Ormeño-Orrillo, Ernesto; Rogel, Marco Antonio; Andrade, Diva Souza; Martínez-Romero, Esperanza; Hungria, Mariangela

    2014-09-01

    Nitrogen (N), the nutrient most required for plant growth, is key for good yield of agriculturally important crops. Common bean (Phaseolus vulgaris L.) can benefit from bacteria collectively called rhizobia, which are capable of fixing atmospheric nitrogen (N2) in root nodules and supplying it to the plant. Common bean is amongst the most promiscuous legume hosts; several described species, in addition to putative novel ones have been reported as able to nodulate this legume, although not always effectively in terms of fixing N2. In this study, we present data indicating that Brazilian strains PRF 35(T), PRF 54, CPAO 1135 and H 52, currently classified as Rhizobium tropici, represent a novel species symbiont of common bean. Morphological, physiological and biochemical properties differentiate these strains from other species of the genus Rhizobium, as do BOX-PCR profiles (less than 60?% similarity), multilocus sequence analysis with recA, gyrB and rpoA (less than 96.4?% sequence similarity), DNA-DNA hybridization (less than 50?% DNA-DNA relatedness), and average nucleotide identity of whole genomes (less than 92.8.%). The novel species is effective in nodulating and fixing N2 with P. vulgaris, Leucaena leucocephala and Leucaena esculenta. We propose the name Rhizobium paranaense sp. nov. for this novel taxon, with strain PRF 35(T) (?=?CNPSo 120(T)?=?LMG 27577(T)?=?IPR-Pv 1249(T)) as the type strain. PMID:24972614

  1. “Item perrexil, mostarda, lechugas et rauanos”. Notas sobre la alimentación de mineros alemanes en Pamplona a finales del siglo XIV (1392

    Directory of Open Access Journals (Sweden)

    Serrano Larráyoz, Fernando

    2008-06-01

    Full Text Available The present article represents an approximation to the food of some German miners settled in Pamplona at the end of the 14th century, to carry out a series of assays intended to determine the kind of metals present in the ore and their actual proportion, with the purpose to verify the profitability of some seams found at Five Villages. Their food accounting for approximately one and a half months, give us first hand information of their habits and of those sharing the table with them. To a certain extent, it is possible to extrapolate these practices to the ones of part of Navarra's salary earners. In them, we could sense certain customs or preferences characteristic of North Europe.

    El presente artículo es una aproximación a la alimentación de unos mineros alemanes que, a finales del siglo XIV, se asientan en Pamplona con el fin de realizar una serie de ensayos (averiguación de los metales que contiene la mena —el mineral metalífero—, y la proporción en que cada uno está con el peso de ella en los que determinar la rentabilidad de algunos filones mineros encontrados en la zona de las Cinco Villas. Las cuentas de los gastos que realizan en alimentación, en aprox. mes y medio, nos acercan de primera mano a los hábitos de estos hombres y de quienes les acompañan en la mesa. Unas prácticas que es posible extrapolar, en cierta medida, a parte de la menestralía navarra, y en las que podemos intuir ciertas costumbres (o gustos propios de la Europa del Norte.

  2. Forestación de un terreno decapitado con Robinia pseudoacacia inoculada con Rhizobium spp. y Glomus deserticola Afforestation of a desurfaced field with Robinia pseudoacacia inoculated with Rhizobium spp. and Glomus deserticola

    Directory of Open Access Journals (Sweden)

    Alejandro E Ferrari

    2010-07-01

    Full Text Available Los terrenos decapitados constituyen un caso extremo de degradación de suelos aptos para agricultura, con graves consecuencias ambientales. El propósito de este trabajo fue ensayar los efectos de la inoculación de acacia blanca (Robinia pseudoacacia L. con una cepa efectiva de Rhizobium y un hongo de micorrizas arbusculares (Glomus deserticola en la supervivencia y crecimiento temprano de plantas trasplantadas a un terreno decapitado de Balcarce, comparando con fresno como árbol no fijador de nitrógeno. La supervivencia inicial fue muy buena (mayor del 77%, especialmente para los fresnos y las acacias inoculadas, las cuales mostraron significativamente mayor supervivencia al estrés por sequía que las acacias control. Todas las plantas se mostraron igualmente tolerantes al ataque de liebres y al estrés por heladas tardías. Durante el primer año las acacias inoculadas crecieron más rápido que las no inoculadas. En el segundo año las alturas se equipararon en parte, probablemente por la colonización de las acacias control con rizobios o micorrizas naturales del suelo. De todos modos, las acacias inoculadas siempre mostraron valores mayores de los distintos parámetros de desarrollo (altura total, diámetro de la copa y cantidad de ramificaciones que las plantas control, tanto en los sectores poco decapitados como en los más severamente degradados. En conclusión, la doble inoculación previa de acacia blanca mejoró la supervivencia inicial, aumentó tolerancia a la sequía y el crecimiento en 2 años y medio desde la plantación. Esta práctica de manejo sería entonces muy recomendable para reducir el período de vivero en la producción de árboles, así como lograr ejemplares más resistentes y mejor adaptados para proyectos de recuperación de suelos degradados.Many agricultural lands in Buenos Aires Province (Argentina have traditionally been desurfaced for the manufacture of bricks and other building materials. The desurfaced soils represent an extreme situation of degradation, having severe consequences for the environment. The purpose of this work was to assay the effects of inoculation of black locust (Robinia pseudoacacia L. with Rhizobium and with a mycorrhizal strain on the survival and early growth of plants in a desurfaced field at the location of Balcarce (37º 45´ S, 58º 18´ O, in Buenos Aires Province (Argentina. The development of inoculated black locust was compared with non-inoculated (control black locust and with the non-fixing green ash (Fraxinus pennsylvanica Marsh.. Survival after two months was very good (>77%, especially for Fraxinus and for inoculated plants. Furthermore, inoculated plants also showed a significantly higher survival rate under drought stress than the control plants. The three kinds of plants showed high tolerance to hare attack and to late frost stress. During the first year, inoculated plants grew more rapidly than non-inoculated controls. During the second year the height of the two treatments was quite similar, probably because of the nodulation of control plants with soil-borne rhizobial or mycorrhizal strains. However, inoculated plants always showed higher development than the control plants according to three growth parameters (total height, canopy diameter and amount of side branches, both in the intact parts of the field and in the most severely extracted sectors. In conclusion, prior inoculation of black locust with effective strains of Rhizobium and mycorrhizal fungi was able to improve initial survival, tolerance to drought and early growth. This management practice is highly recommended to reduce the greenhouse period in the production of trees, and to produce plants more resistant and better adapted to use in reclamation projects of degraded areas.

  3. Forestación de un terreno decapitado con Robinia pseudoacacia inoculada con Rhizobium spp. y Glomus deserticola / Afforestation of a desurfaced field with Robinia pseudoacacia inoculated with Rhizobium spp. and Glomus deserticola

    Scientific Electronic Library Online (English)

    Alejandro E, Ferrari; Carlos A, Esparrach; Mario A, Galetti; Luis G, Wall.

    2010-07-01

    Full Text Available Los terrenos decapitados constituyen un caso extremo de degradación de suelos aptos para agricultura, con graves consecuencias ambientales. El propósito de este trabajo fue ensayar los efectos de la inoculación de acacia blanca (Robinia pseudoacacia L.) con una cepa efectiva de Rhizobium y un hongo [...] de micorrizas arbusculares (Glomus deserticola) en la supervivencia y crecimiento temprano de plantas trasplantadas a un terreno decapitado de Balcarce, comparando con fresno como árbol no fijador de nitrógeno. La supervivencia inicial fue muy buena (mayor del 77%), especialmente para los fresnos y las acacias inoculadas, las cuales mostraron significativamente mayor supervivencia al estrés por sequía que las acacias control. Todas las plantas se mostraron igualmente tolerantes al ataque de liebres y al estrés por heladas tardías. Durante el primer año las acacias inoculadas crecieron más rápido que las no inoculadas. En el segundo año las alturas se equipararon en parte, probablemente por la colonización de las acacias control con rizobios o micorrizas naturales del suelo. De todos modos, las acacias inoculadas siempre mostraron valores mayores de los distintos parámetros de desarrollo (altura total, diámetro de la copa y cantidad de ramificaciones) que las plantas control, tanto en los sectores poco decapitados como en los más severamente degradados. En conclusión, la doble inoculación previa de acacia blanca mejoró la supervivencia inicial, aumentó tolerancia a la sequía y el crecimiento en 2 años y medio desde la plantación. Esta práctica de manejo sería entonces muy recomendable para reducir el período de vivero en la producción de árboles, así como lograr ejemplares más resistentes y mejor adaptados para proyectos de recuperación de suelos degradados. Abstract in english Many agricultural lands in Buenos Aires Province (Argentina) have traditionally been desurfaced for the manufacture of bricks and other building materials. The desurfaced soils represent an extreme situation of degradation, having severe consequences for the environment. The purpose of this work was [...] to assay the effects of inoculation of black locust (Robinia pseudoacacia L.) with Rhizobium and with a mycorrhizal strain on the survival and early growth of plants in a desurfaced field at the location of Balcarce (37º 45´ S, 58º 18´ O), in Buenos Aires Province (Argentina). The development of inoculated black locust was compared with non-inoculated (control) black locust and with the non-fixing green ash (Fraxinus pennsylvanica Marsh.). Survival after two months was very good (>77%), especially for Fraxinus and for inoculated plants. Furthermore, inoculated plants also showed a significantly higher survival rate under drought stress than the control plants. The three kinds of plants showed high tolerance to hare attack and to late frost stress. During the first year, inoculated plants grew more rapidly than non-inoculated controls. During the second year the height of the two treatments was quite similar, probably because of the nodulation of control plants with soil-borne rhizobial or mycorrhizal strains. However, inoculated plants always showed higher development than the control plants according to three growth parameters (total height, canopy diameter and amount of side branches), both in the intact parts of the field and in the most severely extracted sectors. In conclusion, prior inoculation of black locust with effective strains of Rhizobium and mycorrhizal fungi was able to improve initial survival, tolerance to drought and early growth. This management practice is highly recommended to reduce the greenhouse period in the production of trees, and to produce plants more resistant and better adapted to use in reclamation projects of degraded areas.

  4. Establecimiento y respuestas fisiológicas de la simbiosis Rhizobium tropici-Leucaena leucocephala en presencia de fenantreno y naftaleno / Establishment and physiological responses of the Rhizobium tropici-Leucaena leucocephala symbiosis in presence of phenanthrene and naphtalene

    Scientific Electronic Library Online (English)

    Carlos, LÓPEZ-ORTIZ; Ronald, FERRERA-CERRATO; Alejandro, ALARCÓN; Juan José, ALMARAZ; Esperanza, MARTÍNEZ-ROMERO; Ma. Remedios, MENDOZA-LÓPEZ.

    2012-11-01

    Full Text Available Este estudio evaluó el establecimiento de la simbiosis entre Rhizobium tropici CIAT899 y Leucaena leucocephala (Lam.) en sistemas contaminados con naftaleno (NAF) y fenantreno (FEN) y la respuesta de la planta con el contenido de compuestos fenólicos totales (CFT), actividad antioxidante total (AAT) [...] y contenido total de clorofilas (Clo-roT) y carotenos (CaT). A los 31 días, el NAF tuvo efectos negativos en la formación de nódulos, retardando su aparición hasta el día 25 en presencia de 100 mg/L. Ante 20 mg FEN/L, las plantas de L. leucocephala no mostraron diferencias significativas en la formación de nódulos con respecto al testigo, mientras que a 60 y 100 mg FEN/L la nodulación disminuyó significativamente en 52 %. La inoculación con R. tropici incrementó el peso seco total (PST) hasta en 150 % comparado con las plantas no inoculadas. El CFT en hoja fue significativamente mayor en los tratamientos no inoculados en comparación con aquellos inoculados con R. tropici y significativamente mayor ante FEN que con NAF. Para ambos contaminantes, la concentración de 100 mg/L produjo mayor CFT y AAT en comparación con 20 y 60 mg/L. Para el caso de raíz, los tratamientos sin contaminantes en ausencia de R. tropici presentaron mayor CFT y AAT. Para los nódulos, la AAT incrementó significativamente ante NAF, mientras que ante FEN disminuyó. El NAF o el FEN redujeron significativamente el contenido de CloroT, el cual fue significativamente mayor en plantas con Rhizobium en comparación con las plantas no inoculadas. El contenido de CaT en plantas no inoculadas incrementó en presencia de NAF y FEN. Abstract in english This study evaluated the establishment of the symbiosis between Rhizobium tropici CIAT899 and Leucaena leucocephala (Lam.) under contaminated systems with naphtalene (NAF) and phenanthrene (FEN), as well as the physiological plants responses such as total content of phenolic compounds (CFT), total a [...] ntioxidant activity (AAT) and the content of chlorophylls (CloroT) and carotenoids (CaT). After 31 days, NAF had more significant negative effects on nodulation by delaying the formation of nodules until the day 25 at 100 mg/L. In the presence of 20 mg FEN/L, L. leucocephala plants did not show significant differences on the number of nodules when compared to the control, while nodulation decreased 52 % at 60 and 100 mg FEN/L. Inoculation with R. tropici resulted in significant increases of PST (>150 %) in comparison to non-inoculated plants. The foliar content of CFT was significantly greater at non-inoculated treatments in respect to those with R. tropici, and significantly higher in plants exposed to FEN than NAF. For both hydrocarbons, the concentration of 100 mg/L resulted in greater CFT and AAT when compared to 20 or 60 mg/L. For roots, treatments without contamination and R. tropici had more content of CFT and AAT. The AAT in nodules significantly increased due to NAF, while a significant reduction was observed in FEN treatments. Either NAF or FEN did not significantly affect the content of CloroT, although this content was significantly greater in plants with R. tropici than non-inoculated plants. The CaT content significantly increased at non-inoculated plants exposed to NAF and/or FEN.

  5. Bouvard et Pécuchet et le désir amoureux

    Directory of Open Access Journals (Sweden)

    Anne Herschberg Pierrot

    2010-09-01

    Full Text Available L’article propose une étude de genèse du chapitre 7 de Bouvard et Pécuchet, consacré à l’amour, qui forme une étape encyclopédique a priori un peu surprenante. Flaubert s’amuse à écrire ces aventures de Bouvard et Pécuchet, dans un pays qui n’est pas si tendre. L’étude de genèse porte sur le travail de l’écriture de plusieurs temps forts du chapitre (dans l’incipit, et les scènes de duos, notamment la scène entre Mme Castillon et Gorgu. Elle permet de montrer l’effacement de détails érotiques, mais aussi du politique et de l’histoire, qui se trouvent condensés dans le texte final. Elle révèle aussi le rôle concerté de ce chapitre dans la construction du roman et l’itinéraire des personnages. Anodin en apparence, ce chapitre est emblématique d’une poétique fondée sur l’ellipse, et qui mêle le jeu et le sérieux.This article presents a textual genetics study of Bouvard et Pécuchet’s 7th chapter, about love, which appears to be a surprising encyclopedic stage of the novel. Flaubert has fun writing these adventures in a not so tender country. This genetics study focuses on the writing of several key moments of the chapter (in the beginning and the duo scenes, such as the one between Mme Castillon and Gorgu. It reveals the erasure of erotic details, as well as politics and history, which end up condensed in the final text. It also shows this chapter’s concerted role in the construction of the novel and the characters’ development. Apparently minor, this chapter is emblematic of a poetics founded on the ellipsis, mingling play and seriousness.

  6. Produção de mudas de acácia colonizadas com micorrizas e rizóbio em diferentes recipientes Production of acacia plants colonized with mycorrhizas and rhizobium in different recipients

    Directory of Open Access Journals (Sweden)

    Jolimar Antonio Schiavo

    2003-02-01

    Full Text Available Realizou-se um experimento em casa de vegetação, com o objetivo de avaliar diferentes métodos na produção de mudas de Acacia mangium Willd, colonizadas com fungos micorrízicos arbusculares (FMAs e rizóbio. O delineamento experimental foi o inteiramente casualizado num esquema fatorial 4x2 (controle, FMAs, rizóbio e FMAs + rizóbio x blocos prensados e tubetes de plástico, com seis repetições. Os blocos prensados foram confeccionados com substratos orgânicos (bagaço de cana + torta de filtro de usina açucareira e vermiculita, colocados em fôrma metálica de 60x40x20 cm e prensados a 10 kgf cm-2, a fim de proporcionar agregação do material. A inoculação do rizóbio foi realizada com estirpe selecionada para a espécie (Br 3609, Br 6009. A inoculação de FMAs foi feita no momento da confecção dos blocos. Mudas de Acacia mangium que receberam inóculo de FMAs + rizóbio e produzidas em blocos prensados apresentaram maior produção de matéria seca e conteúdo de N na parte aérea. O conteúdo de P na parte aérea é significativamente maior somente nas mudas infectadas com os FMAs, independentemente do tipo de recipiente.A greenhouse experiment was carried out in order to evaluate different methods to produce Acacia mangium Willd plant seedlings, inoculated with arbuscular mycorrhizal fungi (AMF and rhizobium. A completely randomized design in a factorial scheme 4x2 (control, AMF, rhizobium and AMF + rhizobium x pressed blocks and plastic tubes, with six repetitions was used. The pressed blocks used to produce Acacia mangium plants were made with organic residue from sugarcane (sugarcane bagasse + filter cake and vermiculite. The inoculation with rhizobium was done with selected strain (Br 3609, Br 6009. The inoculation with AMF was done at the time when pressed blocks were made. Acacia mangium plants inoculated with both AMF + rhizobium led to a significant increase in dry matter yield and N content of shoot plants, only in pressed blocks. Phosphorus content of shoot plants is significantly higher in seedlings inoculated only with AMF, and it is independent of the plant production system.

  7. Selecting in vitro of Rhizobiumfor tolerance to acidity and aluminium Selección in vitro de Rhizobium tolerante a acidez y aluminio

    Directory of Open Access Journals (Sweden)

    Campos Segura Ricardo

    1995-12-01

    Full Text Available Fifty strains of Rhizobium tropiciisolated of Sabana de Bogotá soils and foreigns collections were screened for tolerance of acidity and aluminium in liquid and sol id culture. Assesment of visible turbidity and colonies growth, respectively, indicated five
    (5 strains tolerant of pH 4.5 and pH 5.0 and 10 or 20 u M Aluminium. Strains that tolerated the 10 west pH values in culture were tolerant of the highest aluminium concentrations
    The cultural test should be used to predict the ability of Rhizobium to growth and for use as inoculants in low pH area.La apertura económica puso de presente la obligación de revisar las formas de producción de los cultivos comerciales, Con el fin de competir adecuadamente en mercados internacionales. Actualmente, leguminosas, como el frijol (Phaseolus vulgarís se presentan, actualmente, como cultivo alternativo para reemplazar cultivos tradicionales en la Sabana de Bogotá. Existe un alto porcentaje de suelos ácidos en Colombia, así como problemas nutricionales, en los cuales la deficiencia de nitrógeno es muy común. El presente trabajo se realizó con el objetivo de seleccionar "in vitro" cepas de Rizobium tropici tolerantes a acidez y aluminio, en medios de cultivo diferentes. Inicialmente se hizo una preselección "in vitro" de cepas tolerantes a tres niveles de pH 4,0; 4,5 y 5,0, utilizando el medio líquido de Wood y Cooper y usando 50 cepas entre nativas y foráneas. En este caso, se seleccionaron las cepas RC 92, RC 117, C 7, C 11, C 14, C 53, Nifta1182, RC 70, RC 85, CIAT 899, CIAT 144 y Niftal 241. Posteriormente, se realizó una selección "in vitro" de cepas tolerantes a dos niveles de pH: 4,5 y 5,0 y a
    cuatro niveles de aluminio: 0,5; 10 y 20 M, utilizando dos fuentes de aluminio: AlCl3 y ALK(S042 y empleando dos medios de cultivo: el líquido de Wood y Cooper y el sólido de Keyser y Munns. Las cepas RC 85, C 11, CIAT 899, CIAT 144 y Niftal 182, fueron seleccionadas como las de mejor
    comportamiento.

  8. Extended region of nodulation genes in Rhizobium meliloti 1021. II. Nucleotide sequence, transcription start sites and protein products

    International Nuclear Information System (INIS)

    The authors have established the DNA sequence and analyzed the transcription and translation products of a series of putative nodulation (nod) genes in Rhizobium meliloti strain 1021. Four loci have been designated nodF, nodE, nodG and nodH. The correlation of transposon insertion positions with phenotypes and open reading frames was confirmed by sequencing the insertion junctions of the transposons. The protein products of these nod genes were visualized by in vitro expression of cloned DNA segments in a R. meliloti transcription-translation system. In addition, the sequence for nodG was substantiated by creating translational fusions in all three reading frames at several points in the sequence; the resulting fusions were expressed in vitro in both E. coli and R. meliloti transcription-translation systems. A DNA segment bearing several open reading frames downstream of nodG corresponds to the putative nod gene mutated in strain nod-216. The transcription start sites of nodF and nodH were mapped by primer extension of RNA from cells induced with the plant flavone, luteolin. Initiation of transcription occurs approximately 25 bp downstream from the conserved sequence designated the nod box, suggesting that this conserved sequence acts as an upstream regulator of inducible nod gene expression. Its distance from the transcription start site is more suggestive of an activator binding site rather than an RNA polymerase binding sitee

  9. Relevance of fucose-rich extracellular polysaccharides produced by Rhizobium sullae strains nodulating Hedysarum coronarium l. legumes.

    Science.gov (United States)

    Gharzouli, Razika; Carpéné, Marie-Anne; Couderc, François; Benguedouar, Ammar; Poinsot, Véréna

    2013-03-01

    Specific and complex interactions between soil bacteria, known as rhizobia, and their leguminous host plants result in the development of root nodules. This process implies a complex dialogue between the partners. Rhizobia synthesize different classes of polysaccharides: exopolysaccharides (EPS), Kdo-rich capsular polysaccharides, lipopolysaccharides, and cyclic ?-(1,2)-glucans. These polymers are actors of a successful symbiosis with legumes. We focus here on studying the EPS produced by Rhizobium sullae bacteria that nodulate Hedysarum coronarium L., largely distributed in Algeria. We describe the influence of the carbon source on the production and on the composition of EPS produced by R. sullae A6 and RHF strains. High-molecular-weight EPS preserve the bacteria from desiccation. The structural characterization of the EPS produced by R. sullae strains has been performed through sugar analysis by gas chromatography-mass spectrometry. The low-molecular-weight EPS of one strain (RHF) has been totally elucidated using nuclear magnetic resonance and quantitative time-of-flight tandem mass spectrometry analyses. An unusual fucose-rich EPS has been characterized. The presence of this deoxy sugar seems to be related to nodulation capacity. PMID:23183977

  10. Effect of N-rate and P sources on BNF in soybean as affected by rhizobium and VAM fungi lnoculants

    International Nuclear Information System (INIS)

    Greenhouse experiment was made to investigate the influence of phosphate fertilizers on nitrogen fixation in soybean. The N-15 isotope dilution method was used to quantify N 2-fixed. In this concern, seed of nodulated and on-nodulated soybean plant bacterized with Bradyrhizobium japonicum and noculated without or with mycorrhizas in the presence of super or rock phosphate. Ammonium sulphate labelled fertilizer (5% N-15 a.e) was applied o 15 kg sandy soil of egypt at the rate of 20 and 100 kg N/acre. At re-flowering stage, the highest amount of N derived from air (Ndfa) was 66.3 and 470.2 (mg/pot) equivalent 47.6 and 47.1 of total N assimilated for noculated soybean with Rhizobium and fertilized with super or rock phosphate, respectively. While the contributions from 15 N labelled fertilizer (Ndff) accounted for 11 and 10.8, respectively. Use of mycorrhizas could increase the amount of N 2-fixed in the presence of rhizobia. There appears to be a strong case for improving N 2-fixation in the presence of mycorrhizas especially in sandy soil. 4 tabs

  11. Genetic diversity of indigenous Rhizobium leguminosarum bv. viciae isolates nodulating two different host plants during soil restoration with alfalfa

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X.X.; Kosier, B.; Priefer, U.B. [Rheinisch-Westfaelische TH Aachen, Aachen (Germany)

    2001-09-01

    A total of 360 Rhizobium leguminosarum bv. viciae strains was isolated from three brown-coal mining restoration fields of different age and plant cover (without and in the first and second year of alfalfa, Medicago sativa, cultivation) using two host species (Vicia hirsuta and Pisum sativum) as capture plants. The strains were genetically typed by restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-generated 16S-23S ribosomal DNA intergenic spacer regions (IGS-RFLP) and characterized by plasmid profiles and RFLP analysis of amplified nodABC genes. The R. leguminosarum bv. viciae population was dominated by the same group of strains (irrespective of the trap plant used). According to type richness, the genetic diversity of indigenous R. leguminosarum in the second year of restoration was lower than in the first year and it resembled that of the fallow field, except for plasmid types, in which it was higher than that of the fallow field. Some of the less frequent nodABC genotypes were associated with distinct chromosomal IGS genotypes and symbiotic plasmids (pSyms) of different sizes, indicating that horizontal transfer and rearrangements of pSym can occur in natural environments. However, the dominant pSym and chromosomal genotypes were strictly correlated suggesting a genetically stable persistence of the prevailing R. leguminosarum bv, viciae genotypes in the absence of its host plant.

  12. Population Genomics Analysis of Legume Host Preference for Specific Rhizobial Genotypes in the Rhizobium leguminosarum bv. viciae Symbioses.

    Science.gov (United States)

    Jorrin, Beatriz; Imperial, Juan

    2015-03-01

    Rhizobium leguminosarum bv. viciae establishes root nodule symbioses with several legume genera. Although most isolates are equally effective in establishing symbioses with all host genera, previous evidence suggests that hosts select specific rhizobial genotypes among those present in the soil. We have used population genomics to further investigate this observation. Pisum sativum, Lens culinaris, Vicia sativa, and V. faba plants were used to trap rhizobia from a well-characterized soil, and pooled genomic DNA from 100 isolates from each plant were sequenced. Sequence reads were aligned to the R. leguminosarum bv. viciae 3841 reference genome. High overall conservation of sequences was observed in all subpopulations, although several multigenic regions were absent from the soil population. A large fraction (16 to 22%) of sequence reads could not be recruited to the reference genome, suggesting that they represent sequences specific to that particular soil population. Although highly conserved, the 16S to 23S ribosomal RNA gene region presented single nucleotide polymorphisms (SNP) regarding the reference genome, but no striking differences could be found among plant-selected subpopulations. Plant-specific SNP patterns were, however, clearly observed within the nod gene cluster, supporting the existence of a plant preference for specific rhizobial genotypes. This was also shown after genome-wide analysis of SNP patterns. PMID:25514682

  13. Rhizobium meliloti produces a family of sulfated lipo-oligosaccharides exhibiting different degrees of plant host specificity

    Energy Technology Data Exchange (ETDEWEB)

    Schultze, M.; Kondorosi, E.; Quiclet-Sire, B.; Gero, S.D. (Centre National de la Recherche Scientifique, Gif-sur-Yvette (France)); Virelizier, H. (Centre d' Etudes Nucleaires, Gif-sur-Yvette (France)); Glushka, J.N. (Univ. of Georgia, Athens (United States)); Endre, G.; Kondorosi, A. (Centre National de la Recherche Scientifique, Gif-sur-Yvette (France) Inst. of Genetics, Szeged (Hungary))

    1992-01-01

    The authors have shown that a Rhizobium meliloti strain over expressing nodulation genes excreted high amounts of a family of N-acylated and 6-O-sulfated N-acetyl-{beta}-1,4-D-glucosamine penta-, tetra-, and trisaccharide Nod factors. Either a C{sub 16:2} or a C{sub 16:3} acyl chain is attached to the nonreducing end subunit, whereas the sulfate group is bound to the reducing glucosamine. In the root hair deformation assay the pentasaccharides show similar activities on the host plants Medicago sativa and Melilotus albus and on the non-host plant Vicia sativa at a dilution of up to 0.01-0.001 {mu}M, in contrast to NodRm-1, which displays a much higher specific activity for Medicago and melilotus than for Vicia. The active concentration range of the pentasaccharides is more narrow on medicago than on Melilotus and Vicia. In addition to root hair deformation, the different Nod factors were shown to induce nodule formation on M. sativa. They suggest that the production of a series of active signal molecules with different degrees of specificity might be important in controlling the symbiosis of R. meliloti with several different host plants or under different environmental conditions.

  14. Integrated use of Rhizobium leguminosarum, Plant Growth Promoting Rhizobacteria and Enriched Compost for Improving Growth, Nodulation and Yield of Lentil (Lens culinaris Medik.) Uso Integrado de Rhizobium leguminosarum, Rizobacterias Promotoras de Crecimiento Vegetal y Compost Enriquecido para Mejorar el Crecimiento, Nodulación y Rendimiento de Lenteja (Lens culinaris Medik.)

    OpenAIRE

    Muhammad Asif Iqbal; Muhammad Khalid; Sher Muhammad Shahzad; Maqshoof Ahmad; Nawaf Soleman; Naeem Akhtar

    2012-01-01

    Maintenance of high bacterial population in the rhizosphere improves the efficiency of these organisms. This high bacterial population can be maintained by the application of enriched compost which supports their growth and activities. Thus integrated use of Rhizobium, plant growth promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) and P-enriched compost (PEC) could be highly effective for promoting growth, nodulation, and yield of lentil (Le...

  15. Accumulation of a nod gene inducer, the flavonoid naringenin, in the cytoplasmic membrane of Rhizobium leguminosarum biovar viciae is caused by the pH-dependent hydrophobicity of naringenin.

    OpenAIRE

    Recourt, K.; Brussel, A. A.; Driessen, A. J.; Lugtenberg, B. J.

    1989-01-01

    Most Sym plasmid-localized nodulation genes of Rhizobium leguminosarum bv. viciae are only expressed upon activation of the NodD protein by plant flavonoids, e.g., naringenin (S. A. J. Zaat, C. A. Wijffelman, H. P. Spaink, A. A. N. van Brussel, and B. J. J. Lugtenberg, J. Bacteriol, 169:198-204, 1987). As part of a study on the mechanism of NodD protein activation, the mechanism of uptake and the intracellular fate of [3H]naringenin were studied. Naringenin was accumulated by Rhizobium cells ...

  16. Isolation and identification of an EPS-producing Rhizobium strain from arid soil (Algeria): characterization of its EPS and the effect of inoculation on wheat rhizosphere soil structure.

    Science.gov (United States)

    Kaci, Yahia; Heyraud, Alain; Barakat, Mohamed; Heulin, Thierry

    2005-05-01

    The production of exopolysaccharides (EPSs) by bacterial populations in the rhizosphere has been demonstrated to contribute to water and nutrient uptake by plant roots through the modification of the physical properties of rhizosphere soil. We report here the characterization of a new EPS produced by a bacterial strain (KYGT207) isolated from an arid soil in southern Algeria (Gassi Touil), and the effect of inoculation of this strain on soil physical properties in the rhizosphere of Triticum durum L. Strain KYGT207 was assigned to the genus Rhizobium by 16S ribosomal DNA sequencing and belongs to a new species closely related to Rhizobium sullae. The EPS produced by this strain was found to be composed of glucose (Glc), galactose (Gal), and mannuronic acid (ManA) in a molar ratio of 2:1:1. The primary structure of the EPS was determined by sugar analysis, 1D and 2D NMR spectroscopy, consisting of a tetrasaccharide repeating unit with the following original structure: [structure: see text]. A rheological analysis showed that this EPS could be considered as a thickening agent with polyelectrolyte properties. Inoculation of wheat plantlets with strain KYGT207 caused significant promotion of plant growth (+85% for shoot dry mass and +56% for root dry mass), a significant increase in root-adhering soil (RAS) dry mass (dm) per root dm (RAS/RT) up to 137%, and in RAS aggregate water stability. We demonstrate that EPS-producing bacteria were present in sandy soils subjected to water stress and that EPS-producing Rhizobium populations play an important role in the rhizosphere through their contribution to soil aggregation. PMID:15862451

  17. The nodD gene of Rhizobium leguminosarum is autoregulatory and in the presence of plant exudate induces the nodA,B,C genes

    OpenAIRE

    Rossen, L.; Shearman, C A; Johnston, A W B; Downie, J. A.

    1985-01-01

    To analyse nod gene expression in Rhizobium leguminosarum, a broad host-range lacZ protein fusion vector was constructed. Two protein fusions, nodC-lacZ and nodD-lacZ, were used to measure the regulation of expression of the promoters of the nodA,B,C and the nodD transcripts by measuring the induced levels of ?-galactosidase activity in R. leguminosarum. In the absence of plant root exudate the nodD-lacZ hybrid was expressed but the nodC-lacZ hybrid was not. The expression of the nodD-lacZ hy...

  18. Rhodobacter sphaeroides rdxA, a homolog of Rhizobium meliloti fixG, encodes a membrane protein which may bind cytoplasmic [4Fe-4S] clusters.

    OpenAIRE

    Neidle, E L; Kaplan, S.

    1992-01-01

    In the photosynthetic bacterium Rhodobacter sphaeroides, a chromosomal gene, rdxA, which encodes a 52-kDa protein, was found to be homologous to fixG, the first gene of a Rhizobium meliloti nitrogen fixation operon on the pSym plasmid (D. Kahn, M. David, O. Domergue, M.-L. Daveran, J. Ghai, P. R. Hirsch, and J. Batut, J. Bacteriol. 171:929-939, 1989). The deduced amino acid sequences of RdxA and FixG are 53% identical and 73% similar; sequence analyses suggested that each has five transmembra...

  19. nodO, a new nod gene of the Rhizobium leguminosarum biovar viciae sym plasmid pRL1JI, encodes a secreted protein.

    OpenAIRE

    Maagd, R. A.; Wijfjes, A. H.; Spaink, H. P.; Ruiz-sainz, J. E.; Wijffelman, C. A.; Okker, R. J.; Lugtenberg, B. J.

    1989-01-01

    The region of the Rhizobium leguminosarum biovar viciae Sym plasmid pRL1JI, responsible for the production and secretion of a previously described 50-kilodalton protein (R. A. de Maagd, C. A. Wijffelman, E. Pees, and B. J. J. Lugtenberg, J. Bacteriol. 170:4424-4427, 1988), was cloned and its nucleotide sequence was determined. A new nod gene, nodO, preceded by a poorly conserved nod box, was identified and its transcriptional start site was determined. Comparison of its predicted protein prod...

  20. The NodD protein does not bind to the promoters of inducible nodulation genes in extracts of bacteroids of Rhizobium leguminosarum biovar viciae.

    OpenAIRE

    Schlaman, H. R.; Lugtenberg, B. J.; Okker, R. J.

    1992-01-01

    In a previous study, we showed that in bacteroids, transcription of the inducible nod genes does not occur and expression of nodD is decreased by 65% (H. R. M. Schlaman, B. Horvath, E. Vijgenboom, R.J.H. Okker, and B. J. J. Lugtenberg, J. Bacteriol. 173:4277-4287, 1991). In the present study, we show, using gel retardation, that in crude extracts of bacteroids of Rhizobium leguminosarum biovar (bv.) viciae, NodD protein does not bind to the nodF, nodM, and nodO box and that it binds only weak...

  1. Isolation and characterization of mutants of Rhizobium leguminosarum bv. viciae 248 with altered lipopolysaccharides: possible role of surface charge or hydrophobicity in bacterial release from the infection thread.

    OpenAIRE

    Maagd, R. A.; Rao, A. S.; Mulders, I. H.; Goosen-de Roo, L.; Loosdrecht, M. C.; Wijffelman, C. A.; Lugtenberg, B. J.

    1989-01-01

    Effects of alterations in lipopolysaccharide (LPS) structure of Rhizobium leguminosarum bv. viciae on effective symbiosis and on a number of cell surface characteristics were studied. Tn5 mutants with altered LPSs were screened for their inability to bind monoclonal antibody 3, one of three monoclonal antibodies to the tentative O-antigenic part of the wild-type LPS of strain 248. Ten class I LPS mutants completely lacked the O-antigen-containing LPS species. The class II LPS mutant had a sev...

  2. Localization and symbiotic function of a region on the Rhizobium leguminosarum Sym plasmid pRL1JI responsible for a secreted, flavonoid-inducible 50-kilodalton protein.

    OpenAIRE

    Maagd, R. A.; Spaink, H. P.; Pees, E.; Mulders, I. H.; Wijfjes, A.; Wijffelman, C. A.; Okker, R. J.; Lugtenberg, B. J.

    1989-01-01

    A previously described (R. A. de Maagd, C. A. Wijffelman, E. Pees, and B. J. J. Lugtenberg, J. Bacteriol. 170:4424-4427, 1988) Sym plasmid-dependent, naringenin-inducible 50-kilodalton protein of Rhizobium leguminosarum biovar viciae is further characterized in this paper. The protein was overproduced by constructing a strain containing multiple copies of the R. meliloti nodD gene, which facilitated its purification. An antiserum was used to screen Tn5 insertion mutants located in the pRL1JI ...

  3. VsENOD5, VsENOD12 and VsENOD40 expression during Rhizobium-induced nodule formation on Vicia sativa roots.

    OpenAIRE

    Vijn, I.; Yang, W. C.; Pallisgard, N.; Ostergaard Jensen, E.; Kammen, A.; Bisseling, T.

    1995-01-01

    We isolated ENOD5, ENOD12 and ENOD40 homologues from Vicia sativa and studied their expression pattern during Rhizobium-induced nodule formation. Comparison of the VsENOD40 nucleotide sequence with the pea, soybean and alfalfa ENOD40 sequences showed that the sequences contain two conserved regions, called region I and region II. Comparison of all the potential open reading frames (ORFs) showed that all the five different ENOD40 clones encode a highly conserved small polypeptide of 12 or 13 a...

  4. Induction of the nodA promoter of Rhizobium leguminosarum Sym plasmid pRL1JI by plant flavanones and flavones.

    OpenAIRE

    Zaat, S. A.; Wijffelman, C. A.; Spaink, H. P.; Brussel, A. A.; Okker, R. J.; Lugtenberg, B. J.

    1987-01-01

    An expression vector containing the Rhizobium leguminosarum nodA promoter cloned in front of the Escherichia coli lacZ gene was used to characterize the properties of the R. leguminosarum nodA gene-inducing compound(s) present in sterile root exudate of the host plant Vicia sativa L. subsp. nigra (L.). The major inducing compound was flavonoid in nature, most likely a flavanone. The commercially available flavonoids naringenin (5,7,4'-trihydroxyflavanone), eriodictyol (5,7,3'4'-tetrahydroxyfl...

  5. Dynamique réactionnelle et processus photoinitiés

    OpenAIRE

    Roncero, Octavio

    2007-01-01

    Le mécanisme direct met en jeu une barrière de potentiel séparant les produits des réactifs, ce qui définit un état de transition conditionnant de nombreuses propriétés étudiées. La nature de l'état de transition peut être analysée dans des expériences de faisceaux croisés, afin de n'observer que des collisions isolées et d'étudier les effets des différentes variables pré- et post-collisionnelle, telles que les distributions d'états initiaux et finals, la distribution angu...

  6. Rhizobium leguminosarum bv. trifolii rosR is required for interaction with clover, biofilm formation and adaptation to the environment

    Directory of Open Access Journals (Sweden)

    Piersiak Tomasz

    2010-11-01

    Full Text Available Abstract Background Rhizobium leguminosarum bv. trifolii is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants Trifolium spp. Bacterial surface polysaccharides are crucial for establishment of a successful symbiosis with legumes that form indeterminate-type nodules, such as Trifolium, Pisum, Vicia, and Medicago spp. and aid the bacterium in withstanding osmotic and other environmental stresses. Recently, the R. leguminosarum bv. trifolii RosR regulatory protein which controls exopolysaccharide production has been identified and characterized. Results In this work, we extend our earlier studies to the characterization of rosR mutants which exhibit pleiotropic phenotypes. The mutants produce three times less exopolysaccharide than the wild type, and the low-molecular-weight fraction in that polymer is greatly reduced. Mutation in rosR also results in quantitative alterations in the polysaccharide constituent of lipopolysaccharide. The rosR mutants are more sensitive to surface-active detergents, antibiotics of the beta-lactam group and some osmolytes, indicating changes in the bacterial membranes. In addition, the rosR mutants exhibit significant decrease in motility and form a biofilm on plastic surfaces, which differs significantly in depth, architecture, and bacterial viability from that of the wild type. The most striking effect of rosR mutation is the considerably decreased attachment and colonization of root hairs, indicating that the mutation affects the first stage of the invasion process. Infection threads initiate at a drastically reduced rate and frequently abort before they reach the base of root hairs. Although these mutants form nodules on clover, they are unable to fix nitrogen and are outcompeted by the wild type in mixed inoculations, demonstrating that functional rosR is important for competitive nodulation. Conclusions This report demonstrates the significant role RosR regulatory protein plays in bacterial stress adaptation and in the symbiotic relationship between clover and R. leguminosarum bv. trifolii 24.2.

  7. Modulation of rosR Expression and Exopolysaccharide Production in Rhizobium leguminosarum bv. trifolii by Phosphate and Clover Root Exudates

    Directory of Open Access Journals (Sweden)

    Anna Skorupska

    2011-06-01

    Full Text Available The acidic exopolysaccharide (EPS secreted in large amounts by the symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum bv. trifolii is required for the establishment of an effective symbiosis with the host plant Trifolium spp. EPS biosynthesis in rhizobia is a very complex process regulated at both transcriptional and post-transcriptional levels and influenced by various nutritional and environmental conditions. The R. leguminosarum bv. trifolii rosR gene encodes a transcriptional regulator with a C2H2 type zinc-finger motif involved in positive regulation of EPS synthesis. In silico sequence analysis of the 450-bp long rosR upstream region revealed the presence of several inverted repeats (IR1 to IR6 and motifs with significant identity to consensus sequences recognized by PhoB and LysR-type proteins associated with phosphate- and flavonoid-dependent gene regulation in R. leguminosarum. Using a set of sequentially truncated rosR-lacZ transcriptional fusions, the role of the individual motifs and the effect of phosphate and clover root exudates on rosR expression were established. In addition, the significance of IR4 inverted repeats in the repression, and P2–10 hexamer in the activation of rosR transcription, respectively, was found. The expression of rosR increased in the presence of phosphate (0.1–20 mM and clover root exudates (10 ?M. PHO boxes and the LysR motif located upstream of the rosR translation start site were engaged in the regulation of rosR transcription. The synthesis of EPS and biofilm formation decreased at high phosphate concentrations, but increased in the presence of clover root exudates, indicating a complex regulation of these processes.

  8. Dual role of HupF in the biosynthesis of [NiFe] hydrogenase in Rhizobium leguminosarum

    Directory of Open Access Journals (Sweden)

    Albareda Marta

    2012-11-01

    Full Text Available Abstract Background [NiFe] hydrogenases are enzymes that catalyze the oxidation of hydrogen into protons and electrons, to use H2 as energy source, or the production of hydrogen through proton reduction, as an escape valve for the excess of reduction equivalents in anaerobic metabolism. Biosynthesis of [NiFe] hydrogenases is a complex process that occurs in the cytoplasm, where a number of auxiliary proteins are required to synthesize and insert the metal cofactors into the enzyme structural units. The endosymbiotic bacterium Rhizobium leguminosarum requires the products of eighteen genes (hupSLCDEFGHIJKhypABFCDEX to synthesize an active hydrogenase. hupF and hupK genes are found only in hydrogenase clusters from bacteria expressing hydrogenase in the presence of oxygen. Results HupF is a HypC paralogue with a similar predicted structure, except for the C-terminal domain present only in HupF. Deletion of hupF results in the inability to process the hydrogenase large subunit HupL, and also in reduced stability of this subunit when cells are exposed to high oxygen tensions. A ?hupF mutant was fully complemented for hydrogenase activity by a C-terminal deletion derivative under symbiotic, ultra low-oxygen tensions, but only partial complementation was observed in free living cells under higher oxygen tensions (1% or 3%. Co-purification experiments using StrepTag-labelled HupF derivatives and mass spectrometry analysis indicate the existence of a major complex involving HupL and HupF, and a less abundant HupF-HupK complex. Conclusions The results indicate that HupF has a dual role during hydrogenase biosynthesis: it is required for hydrogenase large subunit processing and it also acts as a chaperone to stabilize HupL when hydrogenase is synthesized in the presence of oxygen.

  9. Rhizobium tibeticum activated with a mixture of flavonoids alleviates nickel toxicity in symbiosis with fenugreek (Trigonella foenum graecum L.).

    Science.gov (United States)

    Abd-Alla, Mohamed Hemida; Bashandy, Shymaa Ryhan; Bagy, Magdy Khalil; El-enany, Abdel-Wahab Elsadk

    2014-07-01

    The objective of this study is to explore the response of an activated Rhizobium tibeticum inoculum with a mixture of hesperetin (H) and apigenin (A) to improve the growth, nodulation, and nitrogen fixation of fenugreek (Trigonella foenum graecum L.) grown under nickel (Ni) stress. Three different sets of fenugreek seed treatments were conducted, in order to investigate the activated R. tibeticum pre-incubation effects on nodulation, nitrogen fixation and growth of fenugreek under Ni stress. Group (I): uninoculated seeds with R. tibeticum, group (II): inoculated seeds with uninduced R. tibeticum group (III): inoculated seeds with induced R. tibeticum. The present study revealed that Ni induced deleterious effects on rhizobial growth, nod gene expression, nodulation, phenylalanine ammonia-lyase (PAL) and glutamine synthetase activities, total flavonoids content and nitrogen fixation, while the inoculation with an activated R. tibeticum significantly improved these values compared with plants inoculated with uninduced R. tibeticum. PAL activity of roots plants inoculated with induced R. tibeticum and grown hydroponically at 75 and 100 mg L(-1) Ni and was significantly increased compared with plants receiving uninduced R. tibeticum. The total number and fresh mass of nodules, nitrogenase activity of plants inoculated with induced cells grown in soil treated up to 200 mg kg(-1) Ni were significantly increased compared with plants inoculated with uninduced cells. Plants inoculated with induced R. tibeticum dispalyed a significant increase in the dry mass compared with those treated with uninduced R. tibeticum. Activation of R. tibeticum inoculum with a mixture of hesperetin and apigenin has been proven to be practically important in enhancing nodule formation, nitrogen fixation and growth of fenugreek grown in Ni contaminated soils. PMID:24740320

  10. Identification and characterization of RibN, a novel family of riboflavin transporters from Rhizobium leguminosarum and other proteobacteria.

    Science.gov (United States)

    García Angulo, Víctor A; Bonomi, Hernán R; Posadas, Diana M; Serer, María I; Torres, Alfredo G; Zorreguieta, Ángeles; Goldbaum, Fernando A

    2013-10-01

    Rhizobia are symbiotic bacteria able to invade and colonize the roots of legume plants, inducing the formation of nodules, where bacteria reduce atmospheric nitrogen (N2) to ammonia (NH3). Riboflavin availability influences the capacity of rhizobia to survive in the rhizosphere and to colonize roots. In this study, we identified the RL1692 gene of Rhizobium leguminosarum downstream of a flavin mononucleotide (FMN) riboswitch. RL1692 encodes a putative transmembrane permease with two EamA domains. The presence of an FMN riboswitch regulating a transmembrane protein is usually observed in riboflavin transporters, suggesting that RL1692 may be involved in riboflavin uptake. The product of RL1692, which we named RibN, is conserved in members of the alpha-, beta-, and gammaproteobacteria and shares no significant identity with any riboflavin transporter previously identified. In this work, we show that RibN is localized in the membrane cellular fraction and its expression is downregulated by riboflavin. By heterologous expression in a Brucella abortus mutant auxotrophic for riboflavin, we demonstrate that RibN possesses flavin transport activity. Similarly, we also demonstrate that RibN orthologues from Ochrobactrum anthropi and Vibrio cholerae (which lacks the FMN riboswitch) are able to transport riboflavin. An R. leguminosarum ribN null mutant exhibited lower nodule occupancy levels in pea plants during symbiosis assays. Thus, we propose that RibN and its homologues belong to a novel family of riboflavin transporters. This work provides the first experimental description of riboflavin transporters in Gram-negative bacteria. PMID:23935051

  11. Occurrence of polyamines in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici in response to salt stress.

    Science.gov (United States)

    López-Gómez, Miguel; Cobos-Porras, Libertad; Hidalgo-Castellanos, Javier; Lluch, Carmen

    2014-11-01

    Polyamines (PAs) are low molecular weight aliphatic compounds that have been shown to be an important part of plant responses to salt stress. For that reason in this work we have investigated the involvement of PAs in the response to salt stress in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici. The level and variety of PAs was higher in nodules, compared to leaves and roots, and in addition to the common PAs (putrescine, spermidine and spermine) we found homospermidine (Homspd) as the most abundant polyamine in nodules. UPLC-mass spectrometry analysis revealed the presence of 4-aminobutylcadaverine (4-ABcad), only described in nodules of Vigna angularis before. Indeed, the analysis of different nodular fractions revealed higher level of 4-ABcad, as well as Homspd, in bacteroids which indicate the production of these PAs by the bacteria in symbiosis. The genes involved in PAs biosynthesis in nodules displayed an induction under salt stress conditions which was not consistent with the decline of free PAs levels, probably due to the nitrogen limitations provoked by the nitrogenase activity depletion and/or the conversion of free PAs to theirs soluble conjugated forms, that seems to be one of the mechanisms involved in the regulation of PAs levels. On the contrary, cadaverine (Cad) and 4-ABcad concentrations augmented by the salinity, which might be due to their involvement in the response of bacteroids to hyper-osmotic conditions. In conclusion, the results shown in this work suggest the alteration of the bacteroidal metabolism towards the production of uncommon PAs such as 4-ABcad in the response to salt stress in legume root nodules. PMID:25220497

  12. PERANAN FUNGI MIKORIZA ARBUSKULA, MIKROORGANISME PELARUT FOSFAT, RHIZOBIUM SP DAN ASAM HUMIK UNTUK MENINGKATKAN PERTUMBUHAN DAN PRODUKTIVITAS LEGUM Calopogonium mucunoides PADA TANAH LATOSOL DAN TAILING TAMBANG EMAS DI PT. ANEKA TAMBANG

    Directory of Open Access Journals (Sweden)

    - Karti

    2014-06-01

    Full Text Available Latosols soil conditions are poor in nutrients and tailing of gold mine contain heavy metal causes low productivity of forage. The objective of this research to study the best combination of soil potential microorganisms and soil conditioner that can promote the growth and production of legume crops Calopogonium mucunoides Desv. Seven treatments used were A: control, B: arbuscular mycorrhizal fungi (AMF, C: AMF + Rhizobium, D: AMF + Phosphate Solubilizing Bacteria (BPF, E: AMF + Humic Acid, F: AMF + BPF + Rhizobium, G: AMF + BPF + Humic Acid + Rhizobium. Variables measured were the root dry weight, shoot dry weight, spread length, number of trifoliate leaves, the number of active root nodules, the percentage of root infection. Augmentation of soil microorganisms and soil conditioner not effective enough to improve plant growth of Calopogonium mucunoides Desv because plants can still adapt and grow well on latosols. Plants grown on tailings provide the best response is G (AMF+ Humic Acid + Rhizobium, although the rate of growth is not as good as plants grown in latosols.

  13. Life in an Arsenic-Containing Gold Mine: Genome and Physiology of the Autotrophic Arsenite-Oxidizing Bacterium Rhizobium sp. NT-26

    Science.gov (United States)

    Andres, Jérémy; Arsène-Ploetze, Florence; Barbe, Valérie; Brochier-Armanet, Céline; Cleiss-Arnold, Jessica; Coppée, Jean-Yves; Dillies, Marie-Agnès; Geist, Lucie; Joublin, Aurélie; Koechler, Sandrine; Lassalle, Florent; Marchal, Marie; Médigue, Claudine; Muller, Daniel; Nesme, Xavier; Plewniak, Frédéric; Proux, Caroline; Ramírez-Bahena, Martha Helena; Schenowitz, Chantal; Sismeiro, Odile; Vallenet, David; Santini, Joanne M.; Bertin, Philippe N.

    2013-01-01

    Arsenic is widespread in the environment and its presence is a result of natural or anthropogenic activities. Microbes have developed different mechanisms to deal with toxic compounds such as arsenic and this is to resist or metabolize the compound. Here, we present the first reference set of genomic, transcriptomic and proteomic data of an Alphaproteobacterium isolated from an arsenic-containing goldmine: Rhizobium sp. NT-26. Although phylogenetically related to the plant-associated bacteria, this organism has lost the major colonizing capabilities needed for symbiosis with legumes. In contrast, the genome of Rhizobium sp. NT-26 comprises a megaplasmid containing the various genes, which enable it to metabolize arsenite. Remarkably, although the genes required for arsenite oxidation and flagellar motility/biofilm formation are carried by the megaplasmid and the chromosome, respectively, a coordinate regulation of these two mechanisms was observed. Taken together, these processes illustrate the impact environmental pressure can have on the evolution of bacterial genomes, improving the fitness of bacterial strains by the acquisition of novel functions. PMID:23589360

  14. VsENOD5, VsENOD12 and VsENOD40 expression during Rhizobium-induced nodule formation on Vicia sativa roots.

    DEFF Research Database (Denmark)

    Vijn, I; Yang, W C

    1995-01-01

    We isolated ENOD5, ENOD12 and ENOD40 homologues from Vicia sativa and studied their expression pattern during Rhizobium-induced nodule formation. Comparison of the VsENOD40 nucleotide sequence with the pea, soybean and alfalfa ENOD40 sequences showed that the sequences contain two conserved regions, called region I and region II. Comparison of all the potential open reading frames (ORFs) showed that all the five different ENOD40 clones encode a highly conserved small polypeptide of 12 or 13 amino acids encoded by an ORF located in region I. Furthermore we studied with in situ hybridization the expression pattern of VsENOD5, VsENOD12 and VsENOD40 during Rhizobium-induced nodule formation. Although the expression of these genes is largely similar to that of the pea counterparts, differences where found for the expression of VsENOD12 and VsENOD40 in Vicia. VsENOD12 is expressed in the whole prefixation zone II, whereas in pea ENOD12 is only expressed in the distal part of this zone. VsENOD40 is expressed in the uninfected cells of interzone II-III, while in pea ENOD40 is expressed in both the uninfected and infected cells of this zone. Udgivelsesdato: 1995-Sep

  15. Micorriza arbuscular e rizóbios no enraizamento e nutrição de mudas de angico-vermelho / Arbuscular mycorrhizae and rhizobium in rooting and nutrition of angico-vermelho seedlings

    Scientific Electronic Library Online (English)

    Poliana Coqueiro, Dias; Muriel da Silva Folli, Pereira; Maria Catarina, MegumiKasuya; Haroldo Nogueira de, Paiva; Leandro Silva de, Oliveira; Aloisio, Xavier.

    2012-12-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito da inoculação dos fungos micorrízicos arbusculares (FMAs) e rizóbio no enraizamento, crescimento e nutrição de mudas de angico-vermelho (Anadenanthera macrocarpa (Benth) Brenan) propagadas via miniestaquia. Foram utilizadas seis progênies, das quais foram [...] confeccionadas miniestacas com um par de folhas inteiras, bem como tubetes de 55 cm³ contendo substrato comercial Bioplant®. Foram testados quatro tratamentos: 8 kg m-3 de superfosfato simples (SS) misturados ao substrato; 4 kg m-3 de SS misturados ao substrato; 4 kg m-3 de SS misturados ao substrato e adição de suspensão contendo rizóbios; e 4 kg m-3 de SS e adição de suspensão contendo rizóbios e 5 g de solo contendo esporos de FMAs. Não houve interação entre os tratamentos para percentagem de sobrevivência das miniestacas e percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, na saída da casa de vegetação (30 dias) e da casa de sombra (40 dias), provavelmente em função do sistema radicular ainda estar em formação. Houve diferenças entre as progênies para percentagem de sobrevivência das miniestacas, percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, altura, diâmetro de colo e massa seca da parte aérea. As avaliações das características de crescimento das miniestacas enraizadas, principalmente com relação à sobrevivência a pleno sol (140 dias), evidenciam a eficiência dos rizóbios e FMAs na produção de mudas desta espécie. Conclui-se que a associação simbiótica com rizóbio e/ou FMA favorece a produção de mudas de A. macrocarpa via miniestaquia. Abstract in english The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizae fungi (AMF) and rhizobium on rooting, growth and nutrition of seedlings of angico-red (Anadenanthera macrocarpa (Benth) Brenan) propagated by minicutting. Six progenies were used, of which were prepared c [...] uttings with a pair of complete leaves. It was used a 55 cm³container filled with commercial substrate Bioplant®. Four treatments were tested: 8 kg m-3 of superphosphate (SS) added to substrate; 4 kg m-3 SS added to substrate; 4 kg m-3 SS added to substrate and adition of a suspension solution containing rhizobium; 4 kg m-3 SS and suspension solution containing rhizobium plus 5 g of soil contaminated by AMF spores. There was no interaction among treatments for survival rate of cuttings and roots observed at bottom of the container, evaluated in the greenhouse exit (30 days) and the shade house exit (40 days), probably because the root system was still in formation. There were differences among the progeny for survival rate of the shoots, the percentage of cuttings with roots observed at bottom of the container, height, stem diameter and shoot dry weight. The evaluations of the growth characteristics of the cuttings in, particularly with respect to survival at full sun (140 days), demonstrate the efficiency of rhizobium and AMF on seedling production of this species. We conclude that the symbiotic association with rhizobium and / or FMA favors the production of seedlings of A. macrocarpa by minicutting.

  16. Micorriza arbuscular e rizóbios no enraizamento e nutrição de mudas de angico-vermelho Arbuscular mycorrhizae and rhizobium in rooting and nutrition of angico-vermelho seedlings

    Directory of Open Access Journals (Sweden)

    Poliana Coqueiro Dias

    2012-12-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito da inoculação dos fungos micorrízicos arbusculares (FMAs e rizóbio no enraizamento, crescimento e nutrição de mudas de angico-vermelho (Anadenanthera macrocarpa (Benth Brenan propagadas via miniestaquia. Foram utilizadas seis progênies, das quais foram confeccionadas miniestacas com um par de folhas inteiras, bem como tubetes de 55 cm³ contendo substrato comercial Bioplant®. Foram testados quatro tratamentos: 8 kg m-3 de superfosfato simples (SS misturados ao substrato; 4 kg m-3 de SS misturados ao substrato; 4 kg m-3 de SS misturados ao substrato e adição de suspensão contendo rizóbios; e 4 kg m-3 de SS e adição de suspensão contendo rizóbios e 5 g de solo contendo esporos de FMAs. Não houve interação entre os tratamentos para percentagem de sobrevivência das miniestacas e percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, na saída da casa de vegetação (30 dias e da casa de sombra (40 dias, provavelmente em função do sistema radicular ainda estar em formação. Houve diferenças entre as progênies para percentagem de sobrevivência das miniestacas, percentagem de miniestacas com raízes observadas na extremidade inferior do tubete, altura, diâmetro de colo e massa seca da parte aérea. As avaliações das características de crescimento das miniestacas enraizadas, principalmente com relação à sobrevivência a pleno sol (140 dias, evidenciam a eficiência dos rizóbios e FMAs na produção de mudas desta espécie. Conclui-se que a associação simbiótica com rizóbio e/ou FMA favorece a produção de mudas de A. macrocarpa via miniestaquia.The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizae fungi (AMF and rhizobium on rooting, growth and nutrition of seedlings of angico-red (Anadenanthera macrocarpa (Benth Brenan propagated by minicutting. Six progenies were used, of which were prepared cuttings with a pair of complete leaves. It was used a 55 cm³container filled with commercial substrate Bioplant®. Four treatments were tested: 8 kg m-3 of superphosphate (SS added to substrate; 4 kg m-3 SS added to substrate; 4 kg m-3 SS added to substrate and adition of a suspension solution containing rhizobium; 4 kg m-3 SS and suspension solution containing rhizobium plus 5 g of soil contaminated by AMF spores. There was no interaction among treatments for survival rate of cuttings and roots observed at bottom of the container, evaluated in the greenhouse exit (30 days and the shade house exit (40 days, probably because the root system was still in formation. There were differences among the progeny for survival rate of the shoots, the percentage of cuttings with roots observed at bottom of the container, height, stem diameter and shoot dry weight. The evaluations of the growth characteristics of the cuttings in, particularly with respect to survival at full sun (140 days, demonstrate the efficiency of rhizobium and AMF on seedling production of this species. We conclude that the symbiotic association with rhizobium and / or FMA favors the production of seedlings of A. macrocarpa by minicutting.

  17. Rapport final de la Collaboration CERN-CNRS pour la construction du LHC Accord Technique d'Exécution No 2 Cryostats et assemblage des sections droites courtes (SSS) du LHC

    CERN Document Server

    Bergot, JB; Poncet, A; Rohmig, P; Roy, E; Vincent, D

    2006-01-01

    Depuis 1995 et suite à la signature du protocole de Collaboration, le CERN, le CEA et le CNRS ont étroitement collaboré dans le cadre de la contribution exceptionnelle de la France à la construction du LHC. Pour le CNRS, l'Institut de Physique Nucléaire d'Orsay a pris en charge deux Accords Techniques d'Exécution. Le premier concerne la conception et l'assemblage des Sections Droites Courtes de la machine, et le deuxième, l'étalonnage des thermomètres cryogéniques du LHC. Dans le cadre de l'Accord Technique d'Exécution N°2, le Bureau d'Etudes de la Division Accélérateur de l'IPNO et le groupe AT-CRI du CERN ont travaillé de concert pour mener à bien la conception des SSS (Short Straight Section) et de tous les équipements nécessaires à l'assemblage. Ce rapport a donc pour objectif de dresser, en termes d'historique, d'organisation, de résultats quantitatifs et qualitatifs et de moyens mis en ?uvre, un tableau aussi complet que possible du déroulement de cette Collaboration entre le CERN e...

  18. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Gurney, Kevin R

    2015-01-12

    This document constitutes the final report under DOE grant DE-FG-08ER64649. The organization of this document is as follows: first, I will review the original scope of the proposed research. Second, I will present the current draft of a paper nearing submission to Nature Climate Change on the initial results of this funded effort. Finally, I will present the last phase of the research under this grant which has supported a Ph.D. student. To that end, I will present the graduate student’s proposed research, a portion of which is completed and reflected in the paper nearing submission. This final work phase will be completed in the next 12 months. This final workphase will likely result in 1-2 additional publications and we consider the results (as exemplified by the current paper) high quality. The continuing results will acknowledge the funding provided by DOE grant DE-FG-08ER64649.

  19. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    DeTar, Carleton [P.I.

    2012-12-10

    This document constitutes the Final Report for award DE-FC02-06ER41446 as required by the Office of Science. It summarizes accomplishments and provides copies of scientific publications with significant contribution from this award.

  20. Molecular basis of a microbe-mediated enhancement of symbiotic N/sub 2/-fixation. [Rhizobium meliloti; Pseudomonas syringae pv. tabaci

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, P.J.; Knight, T.J.

    1987-04-01

    Improvement of biological nitrogen fixation represents a potential source of both increased food production and decreased dependence on costly chemical fertilizer. They report the results of an investigation of the molecular basis of a unique, microbial-mediated mechanism for increased growth and nitrogen fixation rates in alfalfa. Inoculation of alfalfa plants with both Rhizobium meliloti and Pseudomonas syringae pv tabaci provides increased growth and N/sub 2/-fixation rates of alfalfa. Tabaci produces tabtoxinine-..beta..-lactam (T..beta..L), an exocellular product and glutamine synthetase (GS) inhibitor. The association of this pathogen with nodulating alfalfa plants appears to alter the normal regulation of nitrogen fixation such that nitrogenase activity is stimulated and GS activity is inhibited. Studies of the soluble amino acids in these nodules and the activities of the ammonia assimilatory enzymes indicate alternative pathways of ammonia assimilation are being employed.

  1. Compatibilidade entre a inoculação de rizóbios e fungicidas aplicados em sementes de feijoeiro-comum / Compatibility between rhizobium inoculation and fungicide application in seeds of common beans

    Scientific Electronic Library Online (English)

    Maurício Rocha, Kintschev; Augusto César Pereira, Goulart; Fábio Martins, Mercante.

    2014-12-01

    Full Text Available O objetivo do presente estudo foi avaliar os efeitos do tratamento de sementes de feijoeiro com diferentes fungicidas na sobrevivência de estirpe de Rhizobium tropici (SEMIA 4077) e Rhizobium freirei (SEMIA 4080), na nodulação das plantas e na produtividade da cultura. Foram conduzidos dois ensaios [...] em substrato esterilizado, sob condições de casa de vegetação e um ensaio no campo experimental da Embrapa Agropecuária Oeste, em Dourados, MS, num Latossolo Vermelho distroférrico típico. Os fungicidas (princípios ativos) utilizados nos ensaios foram: (1) carbendazim + tiram (Produto A); (2) carbendazim + tiram (Produto B); (3) carboxin + tiram; (4) fludioxonil + metalaxil-M; (5) fludioxonil + metalaxil-M + tiabendazol; (6) fluazinam + tiofanato metílico; (7) fipronil + tiofanato metílico + piraclostrobina; (8) clorotalonil + tiofanato metílico. A sobrevivência das estirpes de R. tropici inoculadas nas sementes de feijoeiro foi afetada pela aplicação dos fungicidas, principalmente por aqueles com modo de ação de contato. Observou-se ainda, com a aplicação dos fungicidas, redução na nodulação das plantas de feijoeiro, especialmente da massa nodular, tanto nos ensaios conduzidos em substrato esterilizado, em casa de vegetação, quanto no experimento a campo, onde também observou-se redução na produtividade do feijoeiro pela aplicação da maioria dos fungicidas avaliados. Os fungicidas que mais afetaram o rendimento de grãos foram carbendazim + tiram (Produto B) e carboxin + tiram. Os produtos fipronil + tiofanato metílico + piraclostrobina, fludioxonil + metalaxil-M + tiabendazol e fludioxonil + metalaxil-M não afetaram a produtividade da cultura, embora a massa seca de nódulos tenha sido reduzida em todos os ensaios. Abstract in english The aim of this study was to evaluate the effects of treatment of common bean seeds with different fungicides on the survival of strains of Rhizobium tropici (SEMIA 4077) and Rhizobium freirei (SEMIA 4080), as well as on plant nodulation and on crop yield. Two experiments were carried out in sterili [...] zed substrate, under greenhouse conditions and in the experimental field of Embrapa Western Agriculture, in Dourados, Mato Grosso do Sul State, in a typical Oxisol. The fungicides (active ingredients) used in the experiments were: (1) carbendazim + thiram (Product A), (2) carbendazim + thiram (Product B), (3) carboxin + thiram, (4) fludioxonil + metalaxyl-M, (5) fludioxonil + metalaxyl-M + thiabendazole, (6) fluazinam + methyl thiophanate, (7) fipronil + methyl thiophanate + pyraclostrobin, (8) chlorothalonil + methyl thiophanate. The survival of R. tropici strains inoculated in bean seeds was affected by the application of fungicides, especially contact fungicides. In addition, fungicide application led to a reduction in the nodulation of bean plants, especially for nodular mass, either in assays carried out on sterilized substrate, in a greenhouse, or in the field experiment, where grain yield reduction was also noted with the use of most evaluated fungicides. The fungicides that mostly affected grain yield were carbendazim + thiram (Product B) and carboxin + thiram. The products fipronil + thiophanate methyl + pyraclostrobin, fludioxonil + metalaxyl-M + thiabendazole and fludioxonil + metalaxyl-M did not affect the crop yield, although the dry weight of nodules was reduced in all trials.

  2. Cyclic-?-glucans of Rhizobium (Sinorhizobium) sp. strain NGR234 are required for hypo-osmotic adaptation, motility, and efficient symbiosis with host plants.

    Science.gov (United States)

    Gay-Fraret, Jérémie; Ardissone, Silvia; Kambara, Kumiko; Broughton, William J; Deakin, William J; Le Quéré, Antoine

    2012-08-01

    Cyclic-?-glucans (C?G) consist of cyclic homo-polymers of glucose that are present in the periplasmic space of many Gram-negative bacteria. A number of studies have demonstrated their importance for bacterial infection of plant and animal cells. In this study, a mutant of Rhizobium (Sinorhizobium) sp. strain NGR234 (NGR234) was generated in the cyclic glucan synthase (ndvB)-encoding gene. The great majority of C?G produced by wild-type NGR234 are negatively charged and substituted. The ndvB mutation abolished C?G biosynthesis. We found that, in NGR234, a functional ndvB gene is essential for hypo-osmotic adaptation and swimming, attachment to the roots, and efficient infection of Vigna unguiculata and Leucaena leucocephala. PMID:22583376

  3. Resposta da cultura do feijoeiro à adubação nitrogenada e à inoculação com rizóbio Response of common bean crop to nitrogen fertilization and rhizobium inoculation

    Directory of Open Access Journals (Sweden)

    Rodrigo de Pelegrin

    2009-02-01

    Full Text Available O manejo adequado da adubação nitrogenada representa uma das principais dificuldades da cultura do feijoeiro (Phaseolus vulgaris L.. No entanto, a fixação biológica de nitrogênio é uma fonte alternativa de suprimento deste nutriente à cultura. O presente estudo teve como objetivo avaliar a resposta do feijoeiro à inoculação com rizóbio e ao parcelamento de fertilizante nitrogenado em termos de nodulação das plantas e produtividade de grãos da cultura, bem como a viabilidade econômica da aplicação de fertilizante nitrogenado e, ou, inoculação com rizóbio em feijoeiro. O experimento foi conduzido num Latossolo Vermelho distroférrico, em Dourados, MS. O delineamento experimental utilizado foi o de blocos casualizados, com seis repetições. Os sete tratamentos consistiram da aplicação parcelada de fertilizante nitrogenado em diferentes doses (0, 20, 40, 80 e 160 kg ha-1 de N como ureia na cultura do feijoeiro, cv. Pérola, além de controles com inoculação de Rhizobium tropici combinada ou não com aplicação de 20 kg ha-1 de N. A análise econômica foi efetuada considerando os custos da ureia e sua aplicação a lanço, além do custo do inoculante; os demais custos não foram considerados, por não haver diferença entre os diferentes tratamentos. Foram obtidos o acréscimo de produtividade, o custo de produção, o acréscimo da receita bruta e o acréscimo da receita líquida dos tratamentos, em relação à testemunha sem inoculação e sem adubação nitrogenada. Embora a nodulação das plantas não tenha sido alterada pelos tratamentos, verificou-se tendência de redução conforme o aumento da dose de N aplicada. A inoculação com rizóbio selecionado promoveu rendimentos de grãos de feijoeiros equivalentes à aplicação de 80 kg ha-1 de N. Quando acrescida da adubação com 20 kg ha-1 de N no plantio, a inoculação com rizóbio propiciou acréscimo de receita líquida semelhante à aplicação de 160 kg ha-1 de N e superior ao tratamento com a adubação de 20 kg ha-1 de N sem inoculação, evidenciando a sua importância para obtenção de maior rentabilidade na cultura do feijoeiro.Adequate management of nitrogen fertilizer is one of the main difficulties on common bean (Phaseolus vulgaris L. crop. However, the biological N2 fixation is an alternative source of N supply to this crop. This study had the purpose to evaluate the response of common bean to rhizobium inoculation and split application of N fertilizer in terms of plant nodulation and grain yield. Besides, this study aimed to evaluate the economic viability of using N fertilizer application and/or rhizobium inoculation on the plants. The experiment was carried out on a typic Haplustox in Dourados, Mato Grosso do Sul State. The experimental design was a completely randomized block with six replications. The seven treatments consisted of different levels of N fertilizer (0, 20, 40, 80, and 160 kg ha-1 N as urea applied to common bean, cultivar Pérola, and control treatments with R. tropici inoculation with or without application of 20 kg ha-1 N. In the economic analysis, the cost of urea, broadcast application, and cost of inoculant were taken into account. No other costs were considered since the treatments did not differ. Increases in grain yield, production cost, net and gross income, in relation to the control without inoculation and without nitrogen were obtained. The effect of inoculation of selected rhizobia on bean grain yield was similar to the application of 80 kg ha-1 N. When supplied with 20 kg ha-1 N at sowing, rhizobium inoculation increased grain yield and net income similarly to the application of 160 kg ha-1 N and more than the treatment of 20 kg ha-1 N without inoculant, which demonstrates the importance of the inoculant for an enhanced crop profitability.

  4. Resposta da cultura do feijoeiro à adubação nitrogenada e à inoculação com rizóbio / Response of common bean crop to nitrogen fertilization and rhizobium inoculation

    Scientific Electronic Library Online (English)

    Rodrigo de, Pelegrin; Fábio Martins, Mercante; Ilda Miyuki Nakase, Otsubo; Auro Akio, Otsubo.

    2009-02-01

    Full Text Available O manejo adequado da adubação nitrogenada representa uma das principais dificuldades da cultura do feijoeiro (Phaseolus vulgaris L.). No entanto, a fixação biológica de nitrogênio é uma fonte alternativa de suprimento deste nutriente à cultura. O presente estudo teve como objetivo avaliar a resposta [...] do feijoeiro à inoculação com rizóbio e ao parcelamento de fertilizante nitrogenado em termos de nodulação das plantas e produtividade de grãos da cultura, bem como a viabilidade econômica da aplicação de fertilizante nitrogenado e, ou, inoculação com rizóbio em feijoeiro. O experimento foi conduzido num Latossolo Vermelho distroférrico, em Dourados, MS. O delineamento experimental utilizado foi o de blocos casualizados, com seis repetições. Os sete tratamentos consistiram da aplicação parcelada de fertilizante nitrogenado em diferentes doses (0, 20, 40, 80 e 160 kg ha-1 de N como ureia) na cultura do feijoeiro, cv. Pérola, além de controles com inoculação de Rhizobium tropici combinada ou não com aplicação de 20 kg ha-1 de N. A análise econômica foi efetuada considerando os custos da ureia e sua aplicação a lanço, além do custo do inoculante; os demais custos não foram considerados, por não haver diferença entre os diferentes tratamentos. Foram obtidos o acréscimo de produtividade, o custo de produção, o acréscimo da receita bruta e o acréscimo da receita líquida dos tratamentos, em relação à testemunha sem inoculação e sem adubação nitrogenada. Embora a nodulação das plantas não tenha sido alterada pelos tratamentos, verificou-se tendência de redução conforme o aumento da dose de N aplicada. A inoculação com rizóbio selecionado promoveu rendimentos de grãos de feijoeiros equivalentes à aplicação de 80 kg ha-1 de N. Quando acrescida da adubação com 20 kg ha-1 de N no plantio, a inoculação com rizóbio propiciou acréscimo de receita líquida semelhante à aplicação de 160 kg ha-1 de N e superior ao tratamento com a adubação de 20 kg ha-1 de N sem inoculação, evidenciando a sua importância para obtenção de maior rentabilidade na cultura do feijoeiro. Abstract in english Adequate management of nitrogen fertilizer is one of the main difficulties on common bean (Phaseolus vulgaris L.) crop. However, the biological N2 fixation is an alternative source of N supply to this crop. This study had the purpose to evaluate the response of common bean to rhizobium inoculation a [...] nd split application of N fertilizer in terms of plant nodulation and grain yield. Besides, this study aimed to evaluate the economic viability of using N fertilizer application and/or rhizobium inoculation on the plants. The experiment was carried out on a typic Haplustox in Dourados, Mato Grosso do Sul State. The experimental design was a completely randomized block with six replications. The seven treatments consisted of different levels of N fertilizer (0, 20, 40, 80, and 160 kg ha-1 N as urea) applied to common bean, cultivar Pérola, and control treatments with R. tropici inoculation with or without application of 20 kg ha-1 N. In the economic analysis, the cost of urea, broadcast application, and cost of inoculant were taken into account. No other costs were considered since the treatments did not differ. Increases in grain yield, production cost, net and gross income, in relation to the control without inoculation and without nitrogen were obtained. The effect of inoculation of selected rhizobia on bean grain yield was similar to the application of 80 kg ha-1 N. When supplied with 20 kg ha-1 N at sowing, rhizobium inoculation increased grain yield and net income similarly to the application of 160 kg ha-1 N and more than the treatment of 20 kg ha-1 N without inoculant, which demonstrates the importance of the inoculant for an enhanced crop profitability.

  5. Co-inoculation with Rhizobium and plant growth promoting rhizobacteria (PGPR for inducing salinity tolerance in mung bean under field condition of semi arid climate

    Directory of Open Access Journals (Sweden)

    Muhammad Aamir

    2013-04-01

    Full Text Available Salinity stress severely affects the growth, nodulation and yield of mung bean (Vigna radiata L.. However, its growth can be improved under salinity stress by inoculation/co-inoculation with rhizobia and plant growth promoting rhizobacteria (PGPR containing 1-Aminocyclopropane-1-carboxylic acid (ACC deaminase enzyme. ACC-deaminase containing bacteria regulate the stress induced ethylene production by hydrolyzing the ACC (immediate precursor of ethylene into ammonia and ketobutyric acid, thus improve plant growth by lowering the ethylene level. A study was conducted under salt affected field conditions where pre-isolated strains of Rhizobium and PGPR were used alone as well as in combination for mitigating the salinity stress on growth, nodulation and yield of mung bean by following the randomized complete block design (RCBD. The data were recorded and analyzed statistically to see the difference among treatments.

  6. Uso de micorrizas e rizóbio em cultivo consorciado de eucalipto e sesbânia: II - Absorção e eficiência de utilização de fósforo e frações fosfatadas Use of mycorrhizas and rhizobium in intercropping system of eucalyptus and sesbania: II - Phosphorus uptake and efficiency of use and phosphate phosphate -fractions

    Directory of Open Access Journals (Sweden)

    L. A. Rodrigues

    2003-08-01

    Full Text Available Realizou-se um experimento em casa de vegetação com o objetivo de avaliar os efeitos de fungos micorrízicos arbusculares (FMAs e rizóbio na absorção e eficiência de utilização de P e nas frações fosfatadas em mudas de Eucalyptus grandis, cultivadas em consorciação com Sesbania virgata. Os tratamentos foram: inoculação ou não com FMAs em ambas as espécies de plantas e inoculação ou não com rizóbio na S. virgata, com quatro repetições. Ambas as plantas foram cultivadas em vasos de 6 L de capacidade, durante 100 dias, quando foram colhidas. A inoculação com FMAs ou FMAs + rizóbio aumentou o conteúdo de P no eucalipto, enquanto a inoculação com rizóbio, FMAs ou FMAs + rizóbio aumentou a eficiência de utilização de P. Nas frações de P, avaliadas nas folhas de eucalipto, observou-se aumento do fósforo total solúvel em ácido (PST nos tratamentos com inoculação de rizóbio ou FMAs + rizobio. Nos tratamentos com inoculação com rizóbio, FMAs, FMAs+rizóbio ou sem inoculação, observou-se que 81, 32, 91 e 68%, respectivamente, do PST foram encontrados como fósforo orgânico (Po. Em uma avaliação conjunta das frações fosfatadas e do conteúdo de P na parte aérea do eucalipto, o que aparentemente influenciou o aumento do PST e do Po não foi o conteúdo interno de P na planta, mas, sim, a inoculação do rizóbio na sesbânia.The effects of arbuscular mycorrhizal fungi (AMF and Rhizobium on P uptake and efficiency of use, as well as on the P fractions of Eucalyptus grandis grown in an intercropping system with Sesbania virgata were evaluated under greenhouse conditions. The treatments were: with or without inoculation with AMF of both plant species and with or without inoculation with Rhizobium of S. virgata plants only, in four replications. The two plant species were grown together in pots with a volume of 6 L for 100 days. Inoculations with AMF or with AMF + Rhizobium increased the P content in Eucalyptus plants, while inoculations with Rhizobium, AMF, or with AMF + Rhizobium increased the P utilization efficiency. An increase of total acid-soluble P (PTS in the treatments inoculated with Rhizobium or AMF + Rhizobium was observed in the P fractions of the analyzed Eucalyptus plant leaves. In the inoculation treatments with Rhizobium, AMF, and AMF + Rhizobium, and the control (uninoculated 81, 32, 91, and 68%, respectively, of the PST in the leaves of Eucalyptus plants were found in organic-P (Po form. An evaluation of both the P fractions and P contents of Eucalyptus shoots suggests that the increase of PST and organic-P was caused by the inoculation of Rhizobium in sesbania plants, and not by the internal P plant content.

  7. Characterization and functional analysis of seven flagellin genes in Rhizobium leguminosarum bv. viciae. Characterization of R. leguminosarum flagellins

    Directory of Open Access Journals (Sweden)

    Tambalo Dinah D

    2010-08-01

    Full Text Available Abstract Background Rhizobium leguminosarum bv. viciae establishes symbiotic nitrogen fixing partnerships with plant species belonging to the Tribe Vicieae, which includes the genera Vicia, Lathyrus, Pisum and Lens. Motility and chemotaxis are important in the ecology of R. leguminosarum to provide a competitive advantage during the early steps of nodulation, but the mechanisms of motility and flagellar assembly remain poorly studied. This paper addresses the role of the seven flagellin genes in producing a functional flagellum. Results R. leguminosarum strains 3841 and VF39SM have seven flagellin genes (flaA, flaB, flaC, flaD, flaE, flaH, and flaG, which are transcribed separately. The predicted flagellins of 3841 are highly similar or identical to the corresponding flagellins in VF39SM. flaA, flaB, flaC, and flaD are in tandem array and are located in the main flagellar gene cluster. flaH and flaG are located outside of the flagellar/motility region while flaE is plasmid-borne. Five flagellin subunits (FlaA, FlaB, FlaC, FlaE, and FlaG are highly similar to each other, whereas FlaD and FlaH are more distantly related. All flagellins exhibit conserved amino acid residues at the N- and C-terminal ends and are variable in the central regions. Strain 3841 has 1-3 plain subpolar flagella while strain VF39SM exhibits 4-7 plain peritrichous flagella. Three flagellins (FlaA/B/C and five flagellins (FlaA/B/C/E/G were detected by mass spectrometry in the flagellar filaments of strains 3841 and VF39SM, respectively. Mutation of flaA resulted in non-motile VF39SM and extremely reduced motility in 3841. Individual mutations of flaB and flaC resulted in shorter flagellar filaments and consequently reduced swimming and swarming motility for both strains. Mutant VF39SM strains carrying individual mutations in flaD, flaE, flaH, and flaG were not significantly affected in motility and filament morphology. The flagellar filament and the motility of 3841 strains with mutations in flaD and flaG were not significantly affected while flaE and flaH mutants exhibited shortened filaments and reduced swimming motility. Conclusion The results obtained from this study demonstrate that FlaA, FlaB, and FlaC are major components of the flagellar filament while FlaD and FlaG are minor components for R. leguminosarum strains 3841 and VF39SM. We also observed differences between the two strains, wherein FlaE and FlaH appear to be minor components of the flagellar filaments in VF39SM but these flagellin subunits may play more important roles in 3841. This paper also demonstrates that the flagellins of 3841 and VF39SM are possibly glycosylated.

  8. The application of isotopic (32P and 15N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

    International Nuclear Information System (INIS)

    A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of 15N and 32P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the 15N/14N ratio in plant shoots indicate an enhancement of the N2 fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity (32P/31P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigeither from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the test soil that was Ca deficient at neutral pH. (author)

  9. The application of isotopic ({sup 32}P and {sup 15}N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

    Energy Technology Data Exchange (ETDEWEB)

    Barea, J.M. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)]. E-mail: jmbarea@eez.csic.es; Toro, M.; Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain); Orozco, M.O. [Instituto de Sistematica y Ecologia, Academia Cubana de Ciencias, Habana (Cuba); Campos, E. [Departamento de Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin (CSIC), Granada (Spain); Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)

    2002-05-15

    A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of {sup 15}N and {sup 32}P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the {sup 15}N/{sup 14}N ratio in plant shoots indicate an enhancement of the N{sub 2} fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ({sup 32}P/{sup 31}P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the test soil that was Ca deficient at neutral pH. (author)

  10. In vitro Survival and Nematicidal Activity of Rhizobium, Bradyrhizobium and Sinorhizobium. I. The Influence of Various NaCl Concentrations

    OpenAIRE

    Shahid Shaukat, S.; Siddiqui, Imran A.; Maria Hamid; Ghazala Habib Khan; Syed Azhar Ali

    2002-01-01

    During the survey of the cultivated fields in Karachi and neighborhood (Southern Sindh), 3 strains of Rhizobium phaseoli, 1 strain of R. leguminosarum and R. trifolii each, 5 strains of Sinorhizobium meliloti, 2 strains of Bradyrhizobium japonicum and 3 strains of Bradyrhizobium sp. were isolated and identified. The 15 strains of rhizobia tested for their growth under saline media exhibited varying degree of effects to salt concentrations. Most resistant strain was that of S. meliloti MAT1(R9...

  11. Characterization of a Gene Family of Outer Membrane Proteins (ropB) in Rhizobium leguminosarum bv. viciae VF39SM and the Role of the Sensor Kinase ChvG in Their Regulation ?

    OpenAIRE

    Foreman, Dallas L.; Vanderlinde, Elizabeth M.; Bay, Denise C.; Yost, Christopher K.

    2009-01-01

    The outer membrane of Gram-negative bacteria represents the interface between the bacterium and its external environment. It has a critical role as a protective barrier against harmful substances and is also important in host-bacteria interactions representing the initial physical point of contact between the host cell and bacterial cell. RopB is a previously identified outer membrane protein from Rhizobium leguminosarum bv. viciae that is present in free-living cells but absent in bacteroids...

  12. Purification and partial characterization of the Rhizobium leguminosarum biovar viciae Ca2+-dependent adhesin, which mediates the first step in attachment of cells of the family Rhizobiaceae to plant root hair tips.

    OpenAIRE

    Smit, G.; Logman, T. J.; Boerrigter, M. E.; Kijne, J. W.; Lugtenberg, B. J.

    1989-01-01

    The Ca2+-dependent adhesin which mediates the first step in attachment of bacteria of the family Rhizobiaceae to plant root hair tips was isolated from the surface of Rhizobium leguminosarum biovar viciae cells; its ability to inhibit attachment of R. leguminosarum to pea root hair tips was used as a bioassay. Isolated adhesin was found to be able to inhibit attachment of both carbon-limited and manganese-limited R. leguminosarum cells. A multicolumn purification procedure was developed which...

  13. Un nouvel habitat du Bronze final IIIb dans le Val d’Orléans et ses traces de métallurgie du fer : Bonnée, Les Terres à l’Est du Bourg (Centre, Loiret A new settlement from late Bronze IIIb in the val d’Orléans: Bonnée, Les Terres à l’Est du Bourg (lands to the east of the town (Centre, Loiret

    Directory of Open Access Journals (Sweden)

    Stéphane Joly

    2011-12-01

    Full Text Available La multiplication récente des diagnostics archéologiques autour du petit bourg actuel de Bonnée a permis la détection d’une occupation du Bronze final IIIb (circa 900-750 av. n.-e. sur environ un hectare aux Terres à l’Est du Bourg. Les limites inhérentes à ce type d’intervention réduisent l’interprétation des structures et toute approche spatiale de ce probable habitat repéré. L’étude conjointe des différents mobiliers en particulier céramique et métallurgique, mais aussi le torchis et la faune, atteste de sa culture matérielle et de son intérêt. Ces scories pourraient être parmi les plus anciennes traces en région Centre d’activité métallurgique du fer. Des activités de post-réduction sont avérées et certaines opérations de forgeage sont supposées.La découverte de cet habitat dans ce secteur du lit majeur de la Loire, apporte de nouvelles données concernant l’occupation du sol et ses problématiques évolutives dans le Val d’Orléans sur ces périodes de transition avec le Hallstatt ancien.The recent increase in the archaeological evaluations around the village of Bonnée has enabled the discovery of a final Bronze Age IIIb settlement (circa 900-750 BP on about a hectare of the Terres à l’Est du Bourg. The limits inherent in this type of work restrict the interpretation of structures and all spatial approaches to this likely dwelling. The joint study of the different furnishings, in particular ceramics and metal, but also the cob and fauna, attests to its material culture and its interest. The slag could be amongst the oldest iron metallurgy remains from the Centre region. Some activities of post-forging are proven and certain operations are guessed at. The discovery of this settlement in this sector of the major bed of the Loire, has produced new data concerning the occupation of the land and its evolutionary problems in the valley of Orleans over these periods of transition in the early Hallstatt.

  14. Gérer et alerter

    Directory of Open Access Journals (Sweden)

    Valérie November

    2009-03-01

    Full Text Available Sur la base de deux événements d’inondation ayant touché récemment, dans des contextes politiques, organisationnels et hydrologiques bien différents, de nouveaux quartiers d’habitation, cet article rend compte des pratiques des acteurs impliqués dans des situations d’alerte et de crise en Suisse. Le recensement des acteurs – à travers leur rôle et leur place dans les mécanismes de préparation, d’alerte et de gestion –, ainsi que l’inventaire des documents mobilisés par ceux-ci, ont été réalisés dans les deux cas. Cette analyse a permis d’évaluer la gestion des événements, de déceler les changements organisationnels qui ont suivi les crises et de connaître la conception et le degré de formalisation du risque dont étaient dotés les différents acteurs avant et après les inondations. Plus encore, l’analyse a documenté les nouveaux processus d’alerte et de prévision qui ont été mis en place suite aux événements. Il s’avère ainsi que les épisodes d’inondation agissent de façon décisive sur la production de connaissances, à un degré variable selon les acteurs. Ces épisodes révèlent aussi parfois l’existence de connaissances « en attente » qui ne sont pas encore intégrées dans les procédures institutionnelles. Tant du point de vue de la prévision que de la gestion de la crise, ils permettent aussi de tester les canaux de l’information et de combler les déficits d’organisation, de collaboration et de sécurisation des dispositifs de communication. En outre, les risques et les crises liés aux inondations modifient les dynamiques et les politiques territoriales, conséquences du réajustement des réseaux d’acteurs. La mise en place de dispositifs d’intervention et de gestion de crise se montre cependant plus efficace que la refonte des dispositifs d’aménagement, généralement longue. Toutefois, la mémoire des événements se dégradant avec le temps, une inscription territoriale du risque s’avère nécessaire.Based on two flood events that recently affected new housing areas in very different political, organisational and hydrological contexts, this article examines the practices of actors involved in emergency and crisis situations in Switzerland. In both cases, the actors are identified – through their role and their position in the various procedures related to crisis management – and an inventory is made of the documents used. The study examines how the flood events were managed, identifies the organisational changes that followed the crises, and determines how the risk was conceived and to what extent it was formalised by the different actors both before and after the floods. Finally new forecasting and warning procedures that were set up following the events are described. The study shows that floods have a decisive impact on the production of knowledge, but that this phenomenon varies according to the actors. Events such as floods also sometimes reveal the existence of "latent" knowledge, or knowledge that is available but has not yet been integrated into institutional procedures. In terms of both forecasting and crisis management, these events also provide the opportunity to test information channels and to identify and correct any problems relating to organisation, cooperation or the reliability of means of communication. Among other things, the risks and crises related to flooding modify the dynamics and policies of the local area as a result of readjustments in the networks of actors. The introduction of emergency and crisis management measures appears more effective, however, than the reorganisation of planning and development procedures, a process which generally takes a lot longer. Nevertheless, since the recollection of events tends to fade with time, it is important that risks find a more concrete form of spatial expression on the landscape.

  15. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Susanne

    2015-02-09

    We participated in a FASTER SCM intercomparison for which we ran our SCM for 3 years at the SGP to analyze statistics of the precipitation field (Song et al., 2013). An important feature of these simulations was the use of relaxation forcing to observed T, q, which decouples the model convection from the forcing and allows precipitation errors to emerge. Because the GISS cumulus parameterization includes a trigger that prevents convection until sufficient lifting is present, and because convection at the SGP is usually triggered by mesoscale motions that are not represented in the forcing when relaxation is applied, the duration of SCM precipitation is shorter than observed (Del Genio and Wolf, 2012) and thus its mean precipitation less than observed. However, its diurnal cycle phase is correct, and it is the only operational cumulus parameterization in the intercomparison that does not produce excessive warm season precipitation under weak large-scale forcing conditions.

  16. Recommendations for the management of old uranium mining sites in France. From Limousin sites to other sites, from short- to medium- and long-terms. Final report of the pluralist expertise group on Limousin uranium mines (GEP). Synthesis and final report; Recommandations pour la gestion des anciens sites miniers d'uranium en France. Des sites du Limousin aux autres sites, du court aux moyen et long termes. Rapport final du Groupe d'expertise pluraliste sur les mines d'uranium du Limousin (GEP). Synthese et Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    The final report of the Pluralistic Experts Group for the Uranium mines of Limousin (GEP) brings together the main conclusions and recommendations arising from three and half years of work having mobilized, at the request and with the financial support of French authorities, more than forty experts from a varying range of disciplines and backgrounds. The mission given to GEP by the Ministers of Ecology, Industry and Health, as well as the President of the Nuclear safety Authority, was ambitious. It was not simply a matter of conducting an exhaustive and vigorous investigation of actual impacts, but also to analyse the present situation from a technical point of view starting with actual cases to clarify the options for management and monitoring, and to make recommendations on their development in order to reduce the current impacts and to foresee those in the long term according to the preparation of a long term plan. This final report attempts to develop a coherent framework of recommendations that are as operationally feasible as possible. Thus, the proposals of the GEP underline the need for an comprehensive approach, on the basis of work on the institutional perspectives, of a programme for improvement of knowledge and including a reinforcement of information and dialogue, to frame and guide the characterization of the risks and impacts, the evolution of the surveillance devices and the consolidation of the existing protection systems. These final proposals take account of a whole range of activities undertaken by Areva NC as well as the relevant local and national government organizations; and which integrate certain recommendations already produced by the GEP within the framework of its three interim reports. The GEP sets out six main areas of improvements, within which the GEP makes 15 major recommendations addressed to the public authorities, the owner and all of the stakeholders concerned. These recommendations, largely detailed in the report, aim to: - 1 - renovate and clarify the institutional and legal framework for the management of the former mining - 2 - promote efforts directed at the improvement of knowledge on the sites; to continue the studies and research and to broaden their scope; - 3 - reinforce the relevance of impact evaluations, in particular extending them to the ecosystems; to replace public exposure in the public health risks; - 4 - develop surveillance systems at the sites and the zones potentially located under their influence; - 5 - extend the effort of refitting in order to put in place, as of today, systems that are as robust as possible for the long term, where the risks justify it; - 6 - continue the implementation of the principles of information and participation to make them the drivers of a truly sustainable management system for the sites

  17. Bouvard et Pécuchet et le savoir médical

    Directory of Open Access Journals (Sweden)

    Norioki Sugaya

    2009-01-01

    Full Text Available Le présent article a pour objet le dossier médical que Flaubert a constitué pour la préparation du chapitre III de Bouvard et Pécuchet. Ce dossier considérable, qui contient des notes de lecture prises par le romancier en vue de la rédaction du chapitre médical, nous permet de comprendre à quel point le « comique d’idées » propre au roman encyclopédique est le produit d’un travail intense sur le savoir. L’écriture romanesque de Bouvard explore en effet les configurations épistémologiques de chaque discipline, et met au jour surtout ses apories et ses insuffisances. Nous nous proposons donc d’aborder le dossier médical pour saisir le sens de l’excès documentaire pour l’esthétique flaubertienne. Notre étude se compose de trois parties. D’abord, nous étudierons la composition du dossier en nous demandant quels ouvrages médicaux a lu l’auteur de Bouvard. Ensuite, nous essaierons d’examiner le travail critique de Flaubert pratiqué sur les discours du savoir, en particulier la manière dont il traque et construit des contradictions. Enfin, nous analyserons un épisode du roman, celui de la fièvre typhoïde de Gouy, dont l’étude de la genèse nous montrera l’inscription de l’épistémologique dans la représentation romanesque.This article proposes to study the medical documents gathered by Flaubert for the preparation of Chapter III of Bouvart et Pécuchet. This substantial file, which contains reading notes taken by the novelist for the writing of the medical chapter, allows us to understand to what extent the “comic of ideas”, characteristic of the encyclopedic novel, is the result of an intensive work on knowledge. Indeed, the novelistic writing of Bouvard explores the epistemological configurations of each discipline, and in particular reveals its aporia and its insufficiencies. We have chosen to focus on the medical file in order to understand the meaning of the documentary excess with respect toFlaubert’s esthetics. First we shall study the components of the file, identifying the medical works read by the author of Bouvard. Then we will examine Flaubert’s critical reflection on knowledge, in particular the way he hunts down and constructs contradictions. Finally, we will analyze an episode in the novel, that of Gouy’s typhoid fever. We shall study its genesis which will show the presence of the epistemological in the art of the novel.

  18. Study of vibrations and stabilization of linear collider final doublets at the sub-nanometer scale; Etude des vibrations et de la stabilisation a l'echelle sous-nanometrique des doublets finaux d'un collisionneur lineaire

    Energy Technology Data Exchange (ETDEWEB)

    Bolzon, B

    2007-11-15

    CLIC is one of the current projects of high energy linear colliders. Vertical beam sizes of 0.7 nm at the time of the collision and fast ground motion of a few nanometers impose an active stabilization of the final doublets at a fifth of nanometer above 4 Hz. The majority of my work concerned vibrations and active stabilization study of cantilever and slim beams in order to be representative of the final doublets of CLIC. In a first part, measured performances of different types of vibration sensors associated to an appropriate instrumentation showed that accurate measurements of ground motion are possible from 0.1 Hz up to 2000 Hz on a quiet site. Also, electrochemical sensors answering a priori the specifications of CLIC can be incorporated in the active stabilization at a fifth of nanometer. In a second part, an experimental and numerical study of beam vibrations enabled to validate the efficiency of the numerical prediction incorporated then in the simulation of the active stabilization. Also, a study of the impact of ground motion and of acoustic noise on beam vibrations showed that an active stabilization is necessary at least up to 1000 Hz. In a third part, results on the active stabilization of a beam at its two first resonances are shown down to amplitudes of a tenth of nanometer above 4 Hz by using in parallel a commercial system performing passive and active stabilization of the clamping. The last part is related to a study of a support for the final doublets of a linear collider prototype in phase of finalization, the ATF2 prototype. This work showed that relative motion between this support and the ground is below imposed tolerances (6 nm above 0.1 Hz) with appropriate boundary conditions. (author)

  19. Integrated use of Rhizobium leguminosarum, Plant Growth Promoting Rhizobacteria and Enriched Compost for Improving Growth, Nodulation and Yield of Lentil (Lens culinaris Medik. Uso Integrado de Rhizobium leguminosarum, Rizobacterias Promotoras de Crecimiento Vegetal y Compost Enriquecido para Mejorar el Crecimiento, Nodulación y Rendimiento de Lenteja (Lens culinaris Medik.

    Directory of Open Access Journals (Sweden)

    Muhammad Asif Iqbal

    2012-03-01

    Full Text Available Maintenance of high bacterial population in the rhizosphere improves the efficiency of these organisms. This high bacterial population can be maintained by the application of enriched compost which supports their growth and activities. Thus integrated use of Rhizobium, plant growth promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase and P-enriched compost (PEC could be highly effective for promoting growth, nodulation, and yield of lentil (Lens culinaris Medik.. A field study was conducted to evaluate the potential of Rhizobium, PGPR containing ACC-deaminase and PEC for promoting growth of lentil. For this study, the soil type was sandy clay loam soil having pH 7.6; EC (electrical conductivity 2.8 dS m-1; organic matter (OM 0.59%; total N 0.032%; available P 7.9 mg kg-1, and extractable K 129 mg kg-1. Treatments were replicated thrice, using randomized complete block (RCB design. Results showed that the integrated use of R. leguminosarum with Pseudomonas spp. containing ACC-deaminase along with PEC was highly effective and caused up to 73.5, 73.9, 74.4, 67.5, 73.3, 65.8, 40.5, and 52.5% increase in fresh biomass, grain yield, straw yield, pods plant-1, nodule plant-1, nodule dry weight plant-1, 1000-grain weight, and N content in grain of lentil, respectively, as compared to respective control. It is concluded that integrated use of R. leguminosarum with Pseudomonas spp. having trait ACC-deaminase plus PEC would be an effective approach for better nodulation which consequently improved yield of lentil under natural conditions.La mantención de una alta población bacteriana en la rizósfera mejora la eficiencia de estos organismos. Esta población bacteriana puede ser mantenida por la aplicación de compost enriquecido que mantiene su crecimiento y actividades. Por lo tanto, el uso integrado de Rhizobium, rhizobacterias promotoras de crecimiento vegetal (PGPR conteniendo 1-aminociclopropano-1-carboxilato desaminasa (ACC-desaminasa y compost enriquecido con P (PEC podría ser altamente efectivo en la promoción de crecimiento, nodulación, y producción de lenteja (Lens culinaris Medik.. Un estudio de campo se condujo para evaluar el potencial de Rhizobium, PGPR conteniendo ACC-desaminasa y PEC para promover el crecimiento de lenteja. Para este estudio, el tipo de suelo fue franco-arcillo arenoso con pH 7,6; conductividad eléctrica 2,8 dS m-1; materia orgánica 0,59%; N total 0,032%; P disponible 7,9 mg kg-1, y K extraíble 129 mg kg-1. Los tratamientos se repitieron tres veces, usando diseno de bloques completos al azar. Los resultados mostraron que el uso integrado de R. leguminosarum con Pseudomonas spp. conteniendo ACC-desaminasa junto con PEC fue altamente efectivo y causaron hasta 73.5, 73.9, 74.4, 67.5, 73.3, 65.8, 40.5, y 52.5% de aumento en biomasa fresca, producción de grano, producción de paja, vainas planta-1, peso seco de nódulo por planta, peso de 1000 granos, y contenido de N en grano de lenteja, respectivamente, comparado con el respectivo control. Se concluyó que el uso integrado de R. leguminosarum con Pseudomonas spp. portando el rasgo de ACC-desaminasa más PEC podría ser un apronte efectivo para mejor nodulación que consecuentemente mejoró producción de lenteja bajo condiciones naturales.

  20. Integrated use of Rhizobium leguminosarum, Plant Growth Promoting Rhizobacteria and Enriched Compost for Improving Growth, Nodulation and Yield of Lentil (Lens culinaris Medik.) / Uso Integrado de Rhizobium leguminosarum, Rizobacterias Promotoras de Crecimiento Vegetal y Compost Enriquecido para Mejorar el Crecimiento, Nodulación y Rendimiento de Lenteja (Lens culinaris Medik.)

    Scientific Electronic Library Online (English)

    Muhammad Asif, Iqbal; Muhammad, Khalid; Sher Muhammad, Shahzad; Maqshoof, Ahmad; Nawaf, Soleman; Naeem, Akhtar.

    2012-03-01

    Full Text Available La mantención de una alta población bacteriana en la rizósfera mejora la eficiencia de estos organismos. Esta población bacteriana puede ser mantenida por la aplicación de compost enriquecido que mantiene su crecimiento y actividades. Por lo tanto, el uso integrado de Rhizobium, rhizobacterias promo [...] toras de crecimiento vegetal (PGPR) conteniendo 1-aminociclopropano-1-carboxilato desaminasa (ACC-desaminasa) y compost enriquecido con P (PEC) podría ser altamente efectivo en la promoción de crecimiento, nodulación, y producción de lenteja (Lens culinaris Medik.). Un estudio de campo se condujo para evaluar el potencial de Rhizobium, PGPR conteniendo ACC-desaminasa y PEC para promover el crecimiento de lenteja. Para este estudio, el tipo de suelo fue franco-arcillo arenoso con pH 7,6; conductividad eléctrica 2,8 dS m-1; materia orgánica 0,59%; N total 0,032%; P disponible 7,9 mg kg-1, y K extraíble 129 mg kg-1. Los tratamientos se repitieron tres veces, usando diseno de bloques completos al azar. Los resultados mostraron que el uso integrado de R. leguminosarum con Pseudomonas spp. conteniendo ACC-desaminasa junto con PEC fue altamente efectivo y causaron hasta 73.5, 73.9, 74.4, 67.5, 73.3, 65.8, 40.5, y 52.5% de aumento en biomasa fresca, producción de grano, producción de paja, vainas planta-1, peso seco de nódulo por planta, peso de 1000 granos, y contenido de N en grano de lenteja, respectivamente, comparado con el respectivo control. Se concluyó que el uso integrado de R. leguminosarum con Pseudomonas spp. portando el rasgo de ACC-desaminasa más PEC podría ser un apronte efectivo para mejor nodulación que consecuentemente mejoró producción de lenteja bajo condiciones naturales. Abstract in english Maintenance of high bacterial population in the rhizosphere improves the efficiency of these organisms. This high bacterial population can be maintained by the application of enriched compost which supports their growth and activities. Thus integrated use of Rhizobium, plant growth promoting rhizoba [...] cteria (PGPR) containing 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) and P-enriched compost (PEC) could be highly effective for promoting growth, nodulation, and yield of lentil (Lens culinaris Medik.). A field study was conducted to evaluate the potential of Rhizobium, PGPR containing ACC-deaminase and PEC for promoting growth of lentil. For this study, the soil type was sandy clay loam soil having pH 7.6; EC (electrical conductivity) 2.8 dS m-1; organic matter (OM) 0.59%; total N 0.032%; available P 7.9 mg kg-1, and extractable K 129 mg kg-1. Treatments were replicated thrice, using randomized complete block (RCB) design. Results showed that the integrated use of R. leguminosarum with Pseudomonas spp. containing ACC-deaminase along with PEC was highly effective and caused up to 73.5, 73.9, 74.4, 67.5, 73.3, 65.8, 40.5, and 52.5% increase in fresh biomass, grain yield, straw yield, pods plant-1, nodule plant-1, nodule dry weight plant-1, 1000-grain weight, and N content in grain of lentil, respectively, as compared to respective control. It is concluded that integrated use of R. leguminosarum with Pseudomonas spp. having trait ACC-deaminase plus PEC would be an effective approach for better nodulation which consequently improved yield of lentil under natural conditions.

  1. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Leclerc, Monique Y.

    2014-11-17

    This final report presents the main activities and results of the project “A Carbon Flux Super Site: New Insights and Innovative Atmosphere-Terrestrial Carbon Exchange Measurements and Modeling” from 10/1/2006 to 9/30/2014. It describes the new AmeriFlux tower site (Aiken) at Savanna River Site (SC) and instrumentation, long term eddy-covariance, sodar, microbarograph, soil and other measurements at the site, and intensive field campaigns of tracer experiment at the Carbon Flux Super Site, SC, in 2009 and at ARM-CF site, Lamont, OK, and experiments in Plains, GA. The main results on tracer experiment and modeling, on low-level jet characteristics and their impact on fluxes, on gravity waves and their influence on eddy fluxes, and other results are briefly described in the report.

  2. Evaluación de la fertilización biológica del frijol con cepas nativas de Rhizobium aisladas de un ultisol de la altiplanicie del estado guarico / Evaluation of the biological fertilization on cowpea with nativa Rhizobium strains isoleted from an ultisol in landplane guarico state

    Scientific Electronic Library Online (English)

    Belkys, Rodríguez; Marisol, López.

    2009-12-01

    Full Text Available Se evaluó el efecto de la fertilización biológica en frijol, Vigna unguiculata L., con cepas nativas de Rhizobium aisladas de un Ultisol de la altiplanicie en condiciones de mesa del estado Guárico sobre la producción de materia seca (MS), porcentaje de nódulos (PN), masa nodular (MN), actividad nod [...] ular, (AN), absorción de nitrógeno (N) y absorción de fósforo (P), en condiciones de invernadero. Los tratamientos evaluados fueron: sin biofertilizante, biofertilización con la cepa 1, biofertilización con cepa 2 y biofertilización con una combinación de las cepas 1 y 2, conjuntamente con la aplicación de una fertilización basal de N, P y K reducida, obteniéndose a partir de las variables medidas que la cepa 1 mostró una alta capacidad para colonizar el cultivo, lo cual la convierte en el biofertilizante con mayor potencial para gestionar la fertilización del frijol en los conucos llaneros presentes en la altiplanicie Abstract in english The effect of biological fertilization on cowpea, Vigna unguiculata L., with native Rhizobium strains isolated from an ultisol in landplane condition of Guárico state, Venezuela, was evaluated on dry matter production (MS), nodules percentage (PN), nodular mass (MN), nodular activity (AN), nitrogen [...] uptake (N) and phosphorus uptake (P), in an experiment carried out in greenhouse conditions. The evaluated treatments were: without biofertilization (control), biofertilization with strain 1, biofertilization with strain 2 and biofertilization with consortium strains 1 + 2, jointly with the application of a reduced basal fertilization of N, P and K. the strain1 showed high capacity to colonize the crop, which turn it into biological fertilizer with the greatest potential to manage cowpea fertilization in llaneros homegarden in landplane conditions

  3. nodSU, two new nod genes of the broad host range Rhizobium strain NGR234 encode host-specific nodulation of the tropical tree Leucaena leucocephala.

    Science.gov (United States)

    Lewin, A; Cervantes, E; Chee-Hoong, W; Broughton, W J

    1990-01-01

    Rhizobium species strain NGR234 nodulates at least 35 diverse genera of legumes as well as the nonlegume Parasponia andersonii. Most nodulation genes are located on the 500-kilobase pair symbiotic plasmid, pNGR234a. Previously, three plasmid-borne host range determinants (HsnI, HsnII, and HsnIII) were identified by their ability to extend the nodulation capacity of heterologous rhizobia to include Vigna unguiculata. In this study, we show that HsnII contains two new nod-box linked hsn genes, nodS and nodU.nodS controls nodulation of the tropical tree Leucaena leucocephala, while the nodSU genes regulate nodulation of the pasture legume Desmodium intortum and the grain legume V. unguiculata. Regulation of the nod-box upstream of nodSU by the flavonoid naringenin was shown using a fusion with a promoterless lacZ gene. Determination of the nucleotide sequence of the nodS gene did not reveal homology with any gene in the EMBL library, although Bradyrhizobium japonicum USDA110 contains both nodS and nodU (M. Göttfert, S. Hitz, and H. Hennecke, Molecular Plant-Microbe Interactions 3:308-316, 1990). We suggest that broad host range in NGR234 is controlled in part by a nodD gene which interacts with a wide range of flavonoids, and in part by host-specific nod genes such as nodS. PMID:2134856

  4. Genotypic and symbiotic diversity of Rhizobium populations associated with cultivated lentil and pea in sub-humid and semi-arid regions of Eastern Algeria.

    Science.gov (United States)

    Riah, Nassira; Béna, Gilles; Djekoun, Abdelhamid; Heulin, Karine; de Lajudie, Philippe; Laguerre, Gisèle

    2014-07-01

    The genetic structure of rhizobia nodulating pea and lentil in Algeria, Northern Africa was determined. A total of 237 isolates were obtained from root nodules collected on lentil (Lens culinaris), proteaginous and forage pea (Pisum sativum) growing in two eco-climatic zones, sub-humid and semi-arid, in Eastern Algeria. They were characterised by PCR-restriction fragment length polymorphism (RFLP) of the 16S-23S rRNA intergenic region (IGS), and the nodD-F symbiotic region. The combination of these haplotypes allowed the isolates to be clustered into 26 distinct genotypes, and all isolates were classified as Rhizobium leguminosarum. Symbiotic marker variation (nodD-F) was low but with the predominance of one nod haplotype (g), which had been recovered previously at a high frequency in Europe. Sequence analysis of the IGS further confirmed its high variability in the studied strains. An AMOVA analysis showed highly significant differentiation in the IGS haplotype distribution between populations from both eco-climatic zones. This differentiation was reflected by differences in dominant genotype frequencies. Conversely, no host plant effect was detected. The nodD gene sequence-based phylogeny suggested that symbiotic gene diversity in pea and lentil nodulating rhizobial populations in Algeria was low compared to that reported elsewhere in the world. PMID:24582507

  5. Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of in vitro and root biofilms developed by Rhizobium leguminosarum.

    Science.gov (United States)

    Russo, Daniela M; Abdian, Patricia L; Posadas, Diana M; Williams, Alan; Vozza, Nicolás; Giordano, Walter; Kannenberg, Elmar; Downie, J Allan; Zorreguieta, Angeles

    2015-02-01

    The formation of biofilms is an important survival strategy allowing rhizobia to live on soil particles and plant roots. Within the microcolonies of the biofilm developed by Rhizobium leguminosarum, rhizobial cells interact tightly through lateral and polar connections, forming organized and compact cell aggregates. These microcolonies are embedded in a biofilm matrix, whose main component is the acidic exopolysaccharide (EPS). Our work shows that the O-chain core region of the R. leguminosarum lipopolysaccharide (LPS) (which stretches out of the cell surface) strongly influences bacterial adhesive properties and cell-cell cohesion. Mutants defective in the O chain or O-chain core moiety developed premature microcolonies in which lateral bacterial contacts were greatly reduced. Furthermore, cell-cell interactions within the microcolonies of the LPS mutants were mediated mostly through their poles, resulting in a biofilm with an altered three-dimensional structure and increased thickness. In addition, on the root epidermis and on root hairs, O-antigen core-defective strains showed altered biofilm patterns with the typical microcolony compaction impaired. Taken together, these results indicate that the surface-exposed moiety of the LPS is crucial for proper cell-to-cell interactions and for the formation of robust biofilms on different surfaces. PMID:25416773

  6. Formulation of microbes inoculum: AMF, PSB and Rhizobium isolated of ex-coal mining site for Acacia crassicarpa Cunn. Ex-benth seedlings

    Directory of Open Access Journals (Sweden)

    ENNY WIDYATI

    2007-07-01

    Full Text Available The shoddier succeed land revegetation particularly caused by least adaptability of the seedlings planted on this site. To encourage their growth and survival rate it can be achieved by means do inoculation with the compatible functional microbes such as rhizobium, Psolubilizing bacteria (PSB and/or arbuscular-mycorrhiza fungy (AMF. This reserach is aimed to formulate the most compatible inoculant to support the growth of A. crassicarpa seedlings. Compatibility study is carried out in RCB design with 3 replications, each contain 5 seedlings. Height and biomass are accessed to measure the growth responses of the seedlings. The result showed that the best reponse is given by consortia that consist of the three kinds of these microbes. This increase the shoot biomass (137% compare to the control. The consortia also improved N 164%, P 335% and K 167% in the plant tissues. While pure AMF improved absorption of N plants 80%, P 383% and K 51% compare to the control. It is suggested that to prepare the A. crassicarpa seedlings is better inoculated by consortium of microbes or AMF as a sole inoculant.

  7. Rhizosphere soil aggregation and plant growth promotion of sunflowers by an exopolysaccharide-producing Rhizobium sp. strain isolated from sunflower roots.

    Science.gov (United States)

    Alami, Y; Achouak, W; Marol, C; Heulin, T

    2000-08-01

    Root-adhering soil (RAS) forms the immediate environment where plants take up water and nutrients for their growth. We report the effect of an exopolysaccharide (EPS)-producing rhizobacterium (strain YAS34) on the physical properties of sunflower (Helianthus annuus L.) RAS, associated with plant growth promotion, under both water stress and normal water supply conditions. Strain YAS34 was isolated as a major EPS-producing bacterium from the rhizoplane of sunflowers grown in a French dystric cambisol. Strain YAS34 was assigned to the Rhizobium genus by 16S ribosomal DNA gene sequencing. Inoculation of sunflower seeds and soil with strain YAS34 caused a significant increase in RAS per root dry mass (dm) (up to 100%) and a significant increase in soil macropore volume (12 to 60 microm in diameter). The effect of inoculation on sunflower shoot dm (up to +50%) and root dm (up to +70%) was significant under both normal and water stress conditions. Inoculation with strain YAS34 modified soil structure around the root system, counteracting the negative effect of water deficit on growth. Using [(15)N]nitrate, we showed that inoculation made the use of fertilizer more effective by increasing nitrogen uptake by sunflower plantlets. PMID:10919797

  8. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with “Auxin-Like” Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways

    Science.gov (United States)

    Bhat, Supriya V.; Booth, Sean C.; McGrath, Seamus G. K.; Dahms, Tanya E. S.

    2015-01-01

    There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria. PMID:25919284

  9. Isolation of a DNA polymerase I (polA) mutant of Rhizobium leguminosarum that has significantly reduced levels of an IncQ-group plasmid.

    Science.gov (United States)

    Crank, S F; Downie, J A

    1994-04-01

    A population of Tn5 mutagenized Rhizobium leguminosarum cells was screened for mutants affected in protein secretion by introducing a plasmid carrying the Erwinia chrysanthemi prtB gene and screening for mutants defective in secretion of the protease PrtB. One such mutant (A301) also appeared to be defective in secretion of the R. leguminosarum nodulation protein NodO. Genetic analysis showed that the defect in A301 was caused by the Tn5 insertion. However the DNA sequence adjacent to the site of Tn5 insertion had significant homology to the Escherichia coli polA gene, which encodes DNA polymerase I. The mutant A301 showed increased sensitivity to ultraviolet light, a characteristic of polA mutants of E. coli. The apparent defect in secretion by A301 was due to a large decrease in the copy number of the IncQ group replicon on which prtB and nodO were cloned and this decreased the total amounts of PrtB or NodO protein synthesised and secreted by the polA mutant. The polA mutant had a lower growth rate than the parent strain on both rich and minimal media, but there was no obvious effect of the polA mutation on the symbiosis of R. leguminosarum bv. viciae with pea. PMID:8190065

  10. Bacillus simplex—A Little Known PGPB with Anti-Fungal Activity—Alters Pea Legume Root Architecture and Nodule Morphology When Coinoculated with Rhizobium leguminosarum bv. viciae

    Directory of Open Access Journals (Sweden)

    Ann M. Hirsch

    2013-09-01

    Full Text Available Two strains, 30N-5 and 30VD-1, identified as Bacillus simplex and B. subtilis, were isolated from the rhizospheres of two different plants, a Podocarpus and a palm, respectively, growing in the University of California, Los Angeles (UCLA Mildred E. Mathias Botanical Garden. B. subtilis is a well-known plant-growth promoting bacterial species, but B. simplex is not. B. simplex 30N-5 was initially isolated on a nitrogen-free medium, but no evidence for nitrogen fixation was found. Nevertheless, pea plants inoculated with B. simplex showed a change in root architecture due to the emergence of more lateral roots. When Pisum sativum carrying a DR5::GUSA construct, an indicator for auxin response, was inoculated with either B. simplex 30N-5 or its symbiont Rhizobium leguminosarum bv. viciae 128C53, GUS expression in the roots was increased over the uninoculated controls. Moreover, when pea roots were coinoculated with either B. simplex 30N-5 or B. subtilis 30VD-1 and R. leguminosarum bv. viciae 128C53, the nodules were larger, clustered, and developed more highly branched vascular bundles. Besides producing siderophores and solubilizing phosphate, the two Bacillus spp., especially strain 30VD-1, exhibited anti-fungal activity towards Fusarium. Our data show that combining nodulating, nitrogen-fixing rhizobia with growth-promoting bacteria enhances plant development and strongly supports a coinoculation strategy to improve nitrogen fixation, increase biomass, and establish greater resistance to fungal disease.

  11. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Robert C. [Texas A& M University; Kamon, Teruki [Texas A& M University; Toback, David [Texas A& M University; Safonov, Alexei [Texas A& M University; Dutta, Bhaskar [Texas A& M University; Dimitri, Nanopoulos [Texas A& M University; Pope, Christopher [Texas A& M University; White, James [Texas A& M University

    2013-11-18

    Overview The High Energy Physics Group at Texas A&M University is submitting this final report for our grant number DE-FG02-95ER40917. This grant has supported our wide range of research activities for over a decade. The reports contained here summarize the latest work done by our research team. Task A (Collider Physics Program): CMS & CDF Profs. T. Kamon, A. Safonov, and D. Toback co-lead the Texas A&M (TAMU) collider program focusing on CDF and CMS experiments. Task D: Particle Physics Theory Our particle physics theory task is the combined effort of Profs. B. Dutta, D. Nanopoulos, and C. Pope. Task E (Underground Physics): LUX & NEXT Profs. R. Webb and J. White(deceased) lead the Xenon-based underground research program consisting of two main thrusts: the first, participation in the LUX two-phase xenon dark matter search experiment and the second, detector R&D primarily aimed at developing future detectors for underground physics (e.g. NEXT and LZ).

  12. Final environmental statement related to the operation of Catawba Nuclear Station, Units 1 and 2. Docket Nos. 50-413 and 50-414, Duke Power Company, et al

    International Nuclear Information System (INIS)

    This Final Environmental Statement contains the second assessment of the environmental impact associated with the operation of the Catawba Nuclear Station, Units 1 and 2, pursuant to the National Environmental Policy Act of 1969 (NEPA) and 10 CFR 51, as amended, of the NRC regulations. This statement examines: the affected environment, environmental consequences and mitigating actions, and environmental and economic benefits and costs. Land use and terrestrial and aquatic-ecological impacts will be small. Operational impacts to historic and archeological sites will be negligible. The effects of routine operations, energy transmission, and periodic maintenance of rights-of-way and transmission facilities should not jeopardize any populations of endangered or threatened species. No significant impacts are anticipated from normal operational releases of radioactivity. The risk associated with accidental radiation exposure is very low. The net socioeconomic effects of the project will be beneficial

  13. Role of plant root exudate and Sym plasmid-localized nodulation genes in the synthesis by Rhizobium leguminosarum of Tsr factor, which causes thick and short roots on common vetch.

    OpenAIRE

    Brussel, A. A.; Zaat, S. A.; Cremers, H. C.; Wijffelman, C. A.; Pees, E.; Tak, T.; Lugtenberg, B. J.

    1986-01-01

    In a previous paper it was shown that cocultivation of Rhizobium leguminosarum with the plant Vicia sativa subsp. nigra on solid medium causes a changed mode of growth of the plant roots, resulting in thick and short roots (Tsr). The Sym plasmid present in the bacterium appeared to be essential for causing Tsr (A. A. N. van Brussel, T. Tak, A. Wetselaar, E. Pees, and C. A. Wijffelman, Plant Sci. Lett. 27:317-325, 1982). In the present paper, we show that a role in causing Tsr is general for S...

  14. Imprensa política e pensamento republicano no Paraná no final do XIX / Presse politique et pensée républicaine dans l'état du Paraná à la fin du XIXème siècle / Political journalism and republican thought in late 19th century Paraná

    Scientific Electronic Library Online (English)

    Amélia Siegel, Corrêa.

    2009-02-01

    Full Text Available A crise do regime monárquico brasileiro veio acompanhada do surgimento e da expansão do movimento republicano, no final do século XIX. No período, a imprensa não somente colocou-se como palco dos debates institucionais, como também teve papel de poder informal, vinculado ao governo e à organização p [...] artidária. Tratava-se de uma imprensa de opinião, que tinha como um de seus eixos os comentários partidários. As colunas dos jornais eram usadas para escrever anonimamente o que não podia ser dito publicamente na Assembléia, Senado ou Câmara, constituindo um fórum de discussão alternativo à tribuna. Este artigo busca recuperar os modelos de República que circularam nesses periódicos paranaenses, relacionando-os com as configurações nas quais estavam inseridos e com a posição que ocupavam no campo do poder local e nacional. Todavia, vale lembrar que os ideários republicanos dominantes não foram disseminados sem resistência no Paraná; ao contrário, foram detectados e combatidos localmente, porém sem força política suficiente. Parte-se da perspectiva bourdiesiana de que os discursos não são unicamente signos destinados a serem compreendidos e decifrados, mas também indicativos de status, que se propõem a ser valorados e apreciados, e de autoridade, a serem cridos e obedecidos, por constituírem um objeto da luta simbólica pelo poder. A análise dos discursos republicanos mostra que a política paranaense do final do século XIX era mais um resultado de alianças e desavenças entre grupos do que fruto de posicionamentos ideológicos. Os discursos serviam, majoritariamente, como armas retóricas utilizadas para orientar o enfrentamento intra-elites, movido pelo desejo de participação, o que fez com que tivesse um caráter genérico, alicerçado na concepção do fim dos privilégios, embora sem a ampliação da cidadania. Abstract in english The crisis of the Brazilian monarchical regime was accompanied by the emergence and expansion of the republican movement at the end of the 19th century. During that period, the press not only became the stage of institutional debates but also had the role of an informal power, linked to the governme [...] nt and political party organization. It was a press that expressed opinions and created a space for partisan commentary. Newspaper columns were used to anonymously air that which could not be expressed publicly in the Legislative Assembly, the Senate or the House of Representatives, thus constituting an alternative tribune for debate. This article seeks to give voice to the different republican models that circulated within these state of Paraná newspapers, relating them to the configurations they were a part of and with the position that they held within local and national fields of power. Furthermore, it is important to recognize that the dominant republican ideas were not disseminated without resistance: rather, they were heard and combated at the local level, although efforts in this regard remained lacking in political force. Our analysis incorporates the Bourdieusian perspective according to which discourses are not only signs to be understood and decoded but also status indicators -seeking to be validated and evaluated - and forms of authority, seeking to be believed and obeyed; in both cases, object of struggles over symbolic power. Analysis of republican discourse shows that Paraná state politics of the late 19th century was more a result of alliances and tensions between groups than the fruit of clear ideological stands. Discourses served mostly as rhetorical weapons which were used to orient intra-elite conflict, moved by the desire for participation. This gave them a generic character, based on a notion of putting an end to privilege without widening citizenship rights.

  15. Activation of Rhizobium tibeticum with flavonoids enhances nodulation, nitrogen fixation, and growth of fenugreek (Trigonella foenum-graecum L.) grown in cobalt-polluted soil.

    Science.gov (United States)

    Abd-Alla, Mohamed Hemida; Bagy, Magdy Khalil; El-enany, Abdel-Wahab El-sadek; Bashandy, Shymaa Ryhan

    2014-02-01

    The goal of this study was to investigate the response of activation of Rhizobium tibeticum with mixture of hesperetin and apigenin to improve growth, nodulation, and nitrogen fixation of fenugreek grown under cobalt (Co) stress. The current study showed that high concentrations of Co-induced noxious effects on rhizobial growth, nod gene expression, nodulation, phenylalanine ammonia-lyase (PAL) and glutamine synthetase (GS) activities, total flavonoid content, and nitrogen fixation. Addition of a mixture of hesperetin and apigenin to growth medium supplemented with different concentrations of Co significantly increased bacterial growth. PAL activity of roots grown hydroponically at 100 mg kg(-1) Co and inoculated with induced R. tibeticum was significantly increased compared with plants receiving uninduced R. tibeticum. Total flavonoid content of root exudates of plants inoculated with activated R. tibeticum was significantly increased compared with inoculated plants with unactivated R. tibeticum or uninoculated plants at variant Co dosages. Application of 50 mg kg(-1) Co significantly increased nodulation, GS, nitrogenase activity, and biomass of plants inoculated with either or uninduced R. tibeticum. The total number and fresh mass of nodules, nitrogenase activity, and biomass of plants inoculated with induced cells grown in soil treated with 100 and 200 mg kg(-1) Co were significantly increased compared with plants inoculated with uninduced cells. Induced R. tibeticum with flavonoids significantly alleviates the adverse effect of Co on nod gene expression and therefore enhances nitrogen fixation. Induction of R. tibeticum with compatible flavonoids could be of practical importance in augmenting growth and nitrogen fixation of fenugreek grown in a Co-contaminated agroecosystem. PMID:24366585

  16. Compatibilidade entre tratamento de sementes de amendoim com fungicidas, sobrevivência de Rhizobium e nodulação Compatibility between peanut seed preservation with fungicides, survival of rhizobia and nodulation

    Directory of Open Access Journals (Sweden)

    Eli Sidney Lopes

    1986-01-01

    Full Text Available Conduziu-se um experimento para testar a compatibilidade dos fungicidas captã, PCNB e tirã com a inoculação de sementes de amendoim, cujo tratamento se efetuou simultaneamente com a inoculação ou dez dias antes desta. No momento da inoculação e quatro horas após, fez-se uma contagem de Rhizobium nas sementes, pelo método da diluição e inoculação de gotas em placas, mantendo-se um controle sem aplicação de fungicida. Para se estudar o efeito dos tratamentos na nodulação e fixação, plantaram-se as sementes em solo esterilizado, avaliando-se a nodulação e o teor de ureídeos nas folhas. Somente o captã aplicado simultaneamente à inoculação foi prejudicial à sobrevivência bacteriana nas sementes. De maneira geral, a aplicação dos fungicidas simultaneamente à inoculação mostrou-se prejudicial em relação à antecipada.An experiment was carried out to test the compatibility between peanut seed treated with the fungicides captan, PCNB and thiram with rhizobia inoculation. The application of the fungicides was done either simultaneously or ten days before the inoculation of the seeds. A control, without inoculation, was included. Countings of rhizobia on the seed were made immediately after inoculation and four hours after, by dilution and drop plating technique. In order to study the effect of treatments on nodulation and nitrogen fixation, treated and untreated seeds were planted in gamma irradiated soil and nodulation and leaf ureid content were later evaluated. It was observed that only captan applied to the seed simultaneously with inoculation was significantly deleterious to survival of the rhizobia. In general the application of the fungicide ten days before inoculation caused no significant harmfull effect to survival of rhizobia on the seed.

  17. Mutants in the nodFEL promoter of Rhizobium leguminosarum bv. viciae reveal a role of individual nucleotides in transcriptional activation and protein binding.

    Science.gov (United States)

    Okker, R J; Spaink, H P; Lugtenberg, B J; Schlaman, H R

    2001-02-01

    The highly conserved nod box sequence in the promoters of the inducible nodulation genes of rhizobia is required for transcription activation together with NodD, a LysR-type transcriptional regulator, and a flavonoid as a coinducer. DNA fragments containing nod box sequences form two binding complexes when crude preparations of Rhizobium leguminosarum bv. viciae are used: a NodD-dependent and an additional, NodD-independent complex. The role of individual nucleotides in the conserved nod box sequence in complex formation and in nodulation gene expression was investigated by introducing 13 individual base-pair substitutions in the nodF nod box of R. leguminosarum bv. viciae and studying their effect on promoter activity and protein-DNA complex formation. Two mutants showed decreased NodD binding and decreased promoter activity. Five mutants showed a NodD-dependent complex as with the wild-type nodF nod box, whereas their promoter activity was severely reduced after induction. This result is in agreement with earlier observations that NodD DNA binding also occurs in the absence of inducer. Four mutants were impaired in the formation of the NodD-independent retardation complex. Three of them showed no alterations in promoter activity, meaning that no specific role for the protein forming the NodD-independent complex could be established. The two mutants in the highly conserved LysR motif of the nod box were unable to direct coinducer-dependent promoter activity but, unexpectedly, their retardation patterns were not altered. The remaining two mutants showed constitutive promoter activity. The results are discussed in terms of the relevance of conserved nucleotides and motifs identified in the nod box. PMID:11285743

  18. Caracterización de cepas de Rhizobium y Bradyrhizobium (con habilidad de nodulación) seleccionados de los cultivos de fríjol caupi (Vigna unguiculata) como potenciales bioinóculos / Characterization of Rhizobium and Bradyrhizobiu´s strains (with ability of nodulation) selected from bean (Vigna unguiculata) cultures as a potentials bioinoculants

    Scientific Electronic Library Online (English)

    Bernarda, Cuadrado; Guillermo, Rubio; Winston, Santos.

    2009-01-01

    Full Text Available Los suelos de Latinoamérica son ácidos y deficientes en nitrógeno; por esta razón es necesario explorar nuevas alternativas con el fin de modular el desarrollo de plantas, especialmente las leguminosas. El uso del potencial de las bacterias para inducir nodulación y fijar el nitrógeno en las plantas [...] leguminosas se ha estudiado como una opción con potencial impacto. En este estudio se analizó la diversidad de cepas de rhizobios aislados del fríjol Vigna unguiculata (fríjol caupí) cultivado en el norte del departamento de Bolívar (Colombia). Se identificaron aislados capaces de crecer mejor en ambientes hostiles (los cuales tienen un uso potencial como bioinoculantes). Se describe además un acercamiento a la taxonomía de estas bioespecies. Se caracterizaron 52 cepas de rizobios (basados en sus características morfológicas, requerimientos de cultivo, metabólicas, resistencia a metales y antibióticos y de autenticación). De acuerdo con sus propiedades de crecimiento, el 63,5% fueron de cepas de lento, mientras que el 36,5%, de rápido crecimiento. Prevalecieron las de lento crecimiento con un 63,5% del total sobre un 36,5% de rápido crecimiento. Los aislados fueron caracterizados de acuerdo con sus patrones de asimilación de carbohidratos, y se encontraron microorganismos de los géneros Rhizobium, Bradyrhizobium y Mesorhizobium (12 cepas identificadas como potenciales bioinoculantes). Abstract in english Latin America´s soils are acidic and nitrogen-deficient, for this reason is necessary to explore new alternatives in order to modulate in the development of plants, specially the leguminous plants. The use of bacteria´s potential to induce nodulation and to fix nitrogen in leguminous plants has been [...] studied as an option with potential impact. In our study, we analyzed the diversity of rhizobial isolated of the bean Vigna unguiculata (beans cowpea) cultured in the north of Bolivar department (Colombia). We identified strains able of growing in hostile environment (which have a potential use like bioinoculants). Additionally, we described an approach to taxonomy of these biospecies. We reached the characterization of 52 rhizobial strains (based on their morphologic, requires of culture, metabolic, resistance to metals and antibiotics and authentication characteristics). According with their growing properties, 63.5 % were slow growth strains while the 36.5 % were of rapid growth. The isolates were characterized according to their assimilation carbohydrate´s pattern, finding microorganism as Rhizobium, Bradyrhizobium and Mesorhizobium (12 of which were identified as potential bioinoculants).

  19. Synthesis and adsorption properties of titanosilicates ETS-4 and ETS-10 from fly ash

    International Nuclear Information System (INIS)

    Highlights: ? Titanosilicates (ETS-4 and ETS-10) have been synthesized from waste fly ash. ? These materials showed similar properties to those prepared from traditional starting materials. ? The supernatant liquid after product formation (ETS-4) can be recycled and the final by-product is NaCl. ? These materials can be used for CO2/CH4 and N2 adsorption. - Abstract: ETS-4 and ETS-10 titanosilicates were prepared from fly ash and anatase, as silica and titanium sources respectively, via a hydrothermal procedure for the first time. The fusion of fly ash by alkali was carried out at a relatively low temperature and the use potassium fluoride salt was avoided in the synthesis of ETS. The by-product of this process is mainly NaCl, which is a useful source material for industry. The energy efficiency and yield of the synthesis process was improved by directly recycling the final filtrate after recovering the product viz ETS-4. All the ETS materials were characterized in terms of structural morphology, thermal stability and surface/pore properties. The properties of ETS-4 prepared from fly ash by the filtrate recycling method were comparable to that from commercial sources. The results show that ETS type materials can be prepared from cheaper resources, with good purity, comparable physico-chemical properties as well as excellent adsorption properties with lower environmental impact.

  20. The analysis of core and symbiotic genes of rhizobia nodulating Vicia from different continents reveals their common phylogenetic origin and suggests the distribution of Rhizobium leguminosarum strains together with Vicia seeds.

    Science.gov (United States)

    Alvarez-Martínez, Estela R; Valverde, Angel; Ramírez-Bahena, Martha Helena; García-Fraile, Paula; Tejedor, Carmen; Mateos, Pedro F; Santillana, Nery; Zúñiga, Doris; Peix, Alvaro; Velázquez, Encarna

    2009-08-01

    In this work, we analysed the core and symbiotic genes of rhizobial strains isolated from Vicia sativa in three soils from the Northwest of Spain, and compared them with other Vicia endosymbionts isolated in other geographical locations. The analysis of rrs, recA and atpD genes and 16S-23S rRNA intergenic spacer showed that the Spanish strains nodulating V. sativa are phylogenetically close to those isolated from V. sativa and V. faba in different European, American and Asian countries forming a group related to Rhizobium leguminosarum. The analysis of the nodC gene of strains nodulating V. sativa and V. faba in different continents showed they belong to a phylogenetically compact group indicating that these legumes are restrictive hosts. The results of the nodC gene analysis allow the delineation of the biovar viciae showing a common phylogenetic origin of V. sativa and V. faba endosymbionts in several continents. Since these two legume species are indigenous from Europe, our results suggest a world distribution of strains from R. leguminosarum together with the V. sativa and V. faba seeds and a close coevolution among chromosome, symbiotic genes and legume host in this Rhizobium-Vicia symbiosis. PMID:19603151

  1. Greenhouse effect gases sources and sinks (CO{sub 2}, CH{sub 4}, N{sub 2}O) in grasslands and reduction strategies. Greenhouse effect gases prairies. Final report of the second part of the project. April 2004; Sources et puits de gaz a effet de serre (CO{sub 2}, CH{sub 4}, N{sub 2}O) en prairie paturee et strategies de reduction. GES-Prairies. Rapport final de la seconde tranche du projet. Avril 2004

    Energy Technology Data Exchange (ETDEWEB)

    Soussana, J.F

    2004-04-15

    The project 'GES-Prairies' (Greenhouse Gases - Grasslands) had two main objectives: 1. To measure more accurately the fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O of French grasslands and determine the greenhouse gas (GHG) balance of these areas. 2. To calculate the net GHG emissions of cattle production farms and finally to propose and evaluate some management scenarios leading to a reduction of GHG emissions. This project deals with three different spatial scales: the field scale, the farm scale and finally, the regional scale. At the field scale, during two years, fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O were measured in a mid-mountain permanent grassland, previously managed intensively by cutting and grazing (Laqueuille, Auvergne, France). Results from the first complete year of measurements show that the extensification process (reduction of the stocking rate and stopping N fertilization) allows to stock more carbon in the ecosystem. At the farm scale, We developed a model (FARMSIM, coupled to PASIM) able to simulate the GHG balance of a livestock farm. FARMSIM has been tested with data obtained from a mixed livestock farm in Lorraine (dairy and meat production, annual average stocking rate = 1.3 LU ha{sup -1}) of 100 ha (including 76 ha of grasslands and 21 of annual crops). The results indicate a net emission of 175 t equivalent C-CO{sub 2} for this farm. If expressed per unit of product, it represents 1.34 t equivalent C-CO{sub 2} per LU and per year or 0.54 kg CO{sub 2} per kg of milk and per year. At the regional scale/. The PASIM model has been used to simulate the European grasslands with a spatial resolution of 1' (about 200 * 200 km). For each grid cell, a sensibility analysis allowed to determine the N application which correspond to 30% of the N application that would maximize the annual yield of the pasture. Simulation runs on mixed systems (combining grazing and cutting) show that almost one half of the grassland area is, on average, used for cutting. These simulations predict N{sub 2}O emission factors that are relatively stable for the different grid cells across Europe wit values ranging between 1 and 2% in cut systems and between 3 and 4% under grazing (with organic N application through faeces and urine deposition). Under cutting, the simulations predict a important annual C storage (varying between 0.5 to 6 t C ha-1 y-1). However one must consider that an important part of this storage occurs in the harvested forage. C storage in grazed grasslands (0.3 to 2 t C ha-1 y-1) is lower than in cut grasslands. The simulations indicates therefore that cut grassland could represent an important net GHG sink. In France, the amplitude of this sink could vary between 0.5 and 2 t C CO{sub 2} equivalent ha-1 y-1. The simulations combining cut and grazed grassland, in proportion to the dietary needs, show that,in France, these systems would be a net GHG sink of 2 to 3 t C CO{sub 2} equivalent ha-1 y-1. More realistic results would be obtained if the differences between farming systems were taken into account more specifically. (author)

  2. Final report of the project. Emission of nitrogen oxides by the soils. Measures, modelization, land registry and inventory. Impact on the air quality, the climatic change and the evaluation of possibilities of these emissions reduction; Rapport final du projet. Emissions d'oxydes d'azote par les sols. Mesures, modelisation, cadastre et inventaire. Impact sur la qualite de l'air, le changement climatique, et evaluation des gisements de reduction de ces emissions

    Energy Technology Data Exchange (ETDEWEB)

    Serca, D.; Cortinovis, J. [LA Laboratoire d' Aerologie UMR 5560, 31 - Toulouse (France); Laville, P.; Gabrielle, B. [Institut National de Recherches Agronomiques (INRA), Environnement et Grandes Cultures, 78 - Thiverval-Grignon (France); Beekmann, M.; Ravetta, F. [Universite Pierre et Marie Curie, SA Service d' Aeronomie, 75 - Paris (France); Henault, C. [Institut National de Recherches Agronomiques (INRA-LMS) UMR Microbiologie des Sols-Geosol, 21 - Dijon (France)

    2007-07-01

    This project deals with NOx biosphere-atmosphere exchanges, NOx being considered as an indirect greenhouse gases (tropospheric O{sub 3} precursor). It relies on four laboratory specialized both on the soil-plant-atmosphere interface, and on the atmospheric chemistry. Methodology used bear on a set of in situ and laboratory measurements aiming at improving existing emission parameterization, or building new ones for the agro-ecosystems encountered in France or Europe. In situ measurements allowed to study the emission phenology in relation with relevant environmental parameters (meteorological, soil characteristics, and agricultural). Laboratory measurements allowed to establish an emission algorithm related to the three main parameters, that is, soil temperature, water and ammonia content. This algorithm has been adapted and simplified to spatialize the emissions at the France level. This spatialization was performed using environmental parameters accessible through data base (ECMWF) or agricultural statistics (such as nitrogen inputs, land use, crops). Spatial and temporal extrapolation allowed reaching the main objective, that is, to build a national inventory for a reference year (2002). This inventory allowed determining the contribution of NOx emitted by soil as compared to total emitted NOx, and the proportion of NOx emitted by soil due to fertilizer use. Our study, based on 57% of the French used agricultural area, and extrapolated to the whole arable surface, shows that soils would be responsible of about 5% of the total NOx emissions. On these 5%, 20%, which finally is a rather low percentage, would be linked to fertilizer use. The impact of these emissions on the atmospheric chemistry has been evaluated using the CHIMERE chemistry-transport model. We found that NOx emissions from soil would be of minor importance when compared to the industrial emissions, being a factor of ten lower in France. As a matter of consequence, the impact of the emissions on the maximum ozone concentration during summer months is relatively limited over Europe, but can reach 2 to 3 ppb for some of the rural French regions. (author)

  3. Dicos d'or: finale départementale au CERN

    CERN Multimedia

    1998-01-01

    152 coll\\Â?{e}giens et lyc\\Â?{e}ens vont participer, mercredi au CERN, \\Â {a} la finale d\\Â?{e}partementale des dicos d'or. A l'issue des \\Â?{e}preuves, les candidats visiteront l'acc\\Â?{e}l\\Â?{e}rateur de p articules et rencontreront l'un des inventeurs du Web

  4. Search for h and A neutral Higgs bosons in final states with 4 jets in the experimental data collected by DELPHI detector at LEP200; Recherche de bosons de higgs neutres h et A dans les etats finals a quatre jets, avec le detecteur DELPHI a LEP200

    Energy Technology Data Exchange (ETDEWEB)

    Boonekamp, M. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France)]|[Paris-7 Univ., 75 (France)

    1999-05-01

    Searches for Higgs bosons are presented in the framework of the standard model, of the minimal supersymmetric model, and of itsfirst extension. The data sample used has been collected by Delphi in 1997 and 1998, and represents an integrated luminosity of 212 pb{sup -1}. The final states considered are the bb-bar bb-bar decay of the e{sup +}e{sup -} {yields} hZ process. The methods used for the analyses and for the interpretation of their results are described, as well as the implementation of b-quark identification from leptonic decays. After a first selection, the discrimination between background and signal events is studied, and the most powerful quantities are combined into a single variable. The best signal sensitivity is obtained by a weighted counting of all events, where the weight of the events is defined on the basis of the single variable. An excess of data, encountered in the search for hZ, justifies a separate discussion. The main instrumental and theoretical uncertainties, from which this excess could originate, are discussed. It is shown that the majority of the events in excess do not correspond to a Higgs signal, and that it is difficult to understand the excess as a consequence of imperfect standard process simulation. The results of the searches allow to give limits on the masses of the Higgs bosons in the models under consideration. The data imply m{sub h}>93 GeV in the standard model. In the MSSM, one finds m{sub h}>82.4 GeV and m{sub h} >83.3 GeV, for any tan{beta}. On the simplest extension of the MSSM, the pseudoscalar mass parameter m{sub h} must be greater than 69 GeV for tan{beta} >1. No constraint is found for tan{beta} <1. All limits are given at 95% C.L. (author)

  5. Characterization of a fixLJ-regulated Bradyrhizobium japonicum gene sharing similarity with the Escherichia coli fnr and Rhizobium meliloti fixK genes.

    Science.gov (United States)

    Anthamatten, D; Scherb, B; Hennecke, H

    1992-04-01

    We describe the cloning, sequencing, regulation, and mutational analysis of a Bradyrhizobium japonicum fixK-like gene whose product belongs to the family of Fnr-Crp-related regulatory proteins. The predicted 237-amino-acid FixK protein was found to share between 28 and 38% sequence identity with the Escherichia coli Fnr protein, other bacterial Fnr-like proteins (FnrN, Anr, and HlyX), and two rhizobial FixK proteins. The B. japonicum fixK-like gene, when expressed from a lac promoter, could functionally complement an fnr mutant strain of E. coli and activate transcription from an fnr-dependent promoter in the E. coli background; this activation was sixfold higher in anaerobic cultures than in aerobically grown cells, a finding that suggested oxygen sensitivity of the FixK protein and was consistent with the presence of a cysteine-rich, putatively oxygen-responsive domain at its N-terminal end. Similar to the situation in Rhizobium meliloti, expression of the fixK gene in B. japonicum was shown to be induced at low O2 tension and this induction was dependent on the two-component regulatory system FixLJ. Despite this dependency, however, a B. japonicum fixK mutant did not have the phenotypic characteristics of B. japonicum fixL and fixJ mutants: the fixK mutant was neither Fix- in symbiosis with soybean plants nor defective in anaerobic respiration with nitrate as the terminal electron acceptor. Also, the fixK mutant was unaffected in the expression of one of the two B. japonicum sigma 54 genes, rpoN1, which was previously shown to be controlled by the fixLJ genes. When fixK was introduced into the B. japonicum fixJ mutant and expressed therein from a constitutive promoter (i.e., uncoupling it from regulation by FixJ), the FixK protein thus synthesized fully restored anaerobic nitrate respiration in that strain. We interpret this to mean that the B. japonicum wild type has two homologs of fixLJ-regulated fixK genes which can functionally substitute for each other. PMID:1551834

  6. L’excellence : impossible sans un personnel stable et expérimenté

    CERN Multimedia

    Association du personnel

    2013-01-01

    Le monde entier avait les yeux fixés sur le CERN ce 4 juillet 2012, quand ATLAS et CMS ont annoncé leur découverte d’une particule « compatible avec le Higgs ». Début 2013 il n’a fallu que quelques jours pour régler le LHC et faire tourner des protons et des ions lourds. Toutes ces découvertes et prouesses techniques n’ont été possibles que grâce à l’expérience et la poursuite de l’excellence d’équipes soudées de techniciens et ingénieurs qui ont conçu, construit, mis en marche, et finalement font fonctionner ce complexe d’accélérateurs unique au monde. Un service d’excellence avec un encadrement adéquat Entre 2002 et 2012 (voir Fig. 1), le nombre d’utilisateurs est passé de 5912 à...

  7. Cléopâtre et son goûteur

    OpenAIRE

    Mangematin, Vincent

    2003-01-01

    De William Shakespeare (Hamlet) à Victor Hugo (Lucrèce Borgia), en passant par Tristant et Iseult, Albert Goscinny et René Uderzo (Astérix et Cléopâtre) ou par P. Balland (Une affaire de goût, 2000, Julliard : Paris), la boisson et l'alimentation sont au coeur des controverses mettant en scène négligences, fraudes, trahisons, empoisonnements volontaires et dispositifs permettant de garantir le caractère non toxique des aliments. Se noue ainsi autour de l'alimentation un jeu complexe...

  8. La balle et la plume

    Directory of Open Access Journals (Sweden)

    Peter Marquis

    2012-06-01

    Full Text Available Fin octobre 2008, la nouvelle fit l’effet d’une bombe : Barack Obama, alors candidat à la présidence américaine, demanda à la chaîne câblée Fox News de retarder le début du sixième match de la World Series de base-ball afin de diffuser un spot de campagne. Son adversaire, John McCain, soutenu par le camp républicain et une partie de la population, monta aussitôt au créneau pour dénoncer l’hérésie : s’arroger le droit de perturber cette grande finale du championnat au déroulement immuable reve...

  9. Continuations intra- et interphrastiques du français : premiers résultats expérimentaux

    OpenAIRE

    Bartkova Katarina; Colotte Vincent; Dargnat Mathilde; Bonneau Anne

    2012-01-01

    Continuations intra et interphrastiques du français : premiers résultats expérimentaux Cet article rend compte d’un certain nombre d’observations pour l’étude des continuations mineures et majeures en français. Ces observations ont été obtenues dans le cadre d’un projet en cours sur les patrons prosodiques non-conclusifs en français et en anglais. Ici, Nous discutons plus particulièrement les variations de pente concernant deux types de configurations continuatives : (i) le segment final d’un...

  10. Efeitos da inoculação com rizóbio e da adubação nitrogenada na produção de mudas de Sesbânia em substrato constituído de resíduos agroindustriais / Effect of rhizobium inoculation and nitrogen applications on Sesbânia seedlings produced in substrates composed of agro-industrial residues

    Scientific Electronic Library Online (English)

    Luciana de Lima Brandão, Chaves; José Geraldo de Araújo, Carneiro; Deborah Guerra, Barroso; Paulo Sérgio dos Santos, Leles.

    2003-08-01

    Full Text Available Com o objetivo de avaliar o efeito de diferentes fontes e doses de N e da inoculação com rizóbio na produção de mudas de Sesbania virgata (sesbânia), conduziu-se um experimento no qual se utilizou como substrato composto de bagaço de cana-de-açúcar + torta de filtro de usina peneirados (3:2, v:v) e [...] decompostos. Foram testados os seguintes tratamentos em esquema fatorial: 3 doses de N (100, 200 e 300 mg/dm³) x 3 doses de N (uréia, sulfato de amônio e nitrato de amônio) + 2 tratamentos adicionais (inoculado e não-inoculado com rizóbio). As três adubações foram realizadas a cada 15 dias, sendo a primeira 30 dias após a semeadura. O experimento foi conduzido sob delineamento inteiramente casualizado, com três repetições compostas por 80 mudas. As mudas foram avaliadas em altura, diâmetro, massas de matéria seca da parte aérea e do sistema radicular, área foliar e potencial de regeneração de raízes. Conclui-se que para este substrato a inoculação das sementes foi suficiente para atender à demanda de N das mudas de sesbânia. Abstract in english An experiment was carried out to evaluate the effect of different sources and doses of nitrogen and Rhizobium inoculation on the production of sesbânia seedlings (Sesbania virgata). The substrate was decomposed sugarcane bagasse + filter cake (3:2; v:v). The statistical design was a 3 x 3 x 2 factor [...] ial scheme (3N doses - 100, 200 and 300 mg/dm³ x 3 N sources - urea, ammonium sulfate and ammonium nitrate + two additional treatments - with and without Rhizobium inoculation. The experiment was arranged in a randomized complete design, with three replicates. Each experimental plot was composed of 80 seedlings. Height, diameter, shoot and root dry matter weights, leaf area and root regeneration potential of the seedlings were evaluated. It was concluded that, for this substrate, sesbânia seedlings can be produced without the addition of nitrogen fertilizers.

  11. Hydrologie et géochimie isotopique

    OpenAIRE

    Matray, J. M.; Chery, L.

    1998-01-01

    L'origine et l'âge des eaux profondes du bassin de Paris est discutée à partir d'analyses chimiques et isotopiques effectuées sur près de 150 échantillons d'eau produits par les puits géothermiques, pétroliers et d'eau souterraine du Jurassique moyen (Dogger) et du Trias supérieur (Keuper et Rhétien). Les études effectuées montrent que seules les espèces Cl, Br, 2H et 18O sont actuellement conservées dans les trois aquifères étudiés bien que l'oxygène-18 ait connu dans le pa...

  12. Réseaux et histoires

    Directory of Open Access Journals (Sweden)

    Harrison White

    2007-10-01

    Full Text Available Les réseaux sociaux ne sont pas constitués de « tuyaux » reliant des entités figées. Ils résultent des efforts de contrôle des identités pour faire face à l’incertitude radicale, aussi bien dans le monde social que dans le monde bio-physique. Ces efforts de contrôle produisent des histoires, dont dérivent les liens qui constituent les réseaux. Ainsi, une relation est interprétée à travers des histoires, non seulement par ceux qui y participent mais aussi par les observateurs. Les histoires s’enchevêtrent et forment des assemblages dans lesquels des régularités peuvent être observées, notamment trois façons de différencier les liens. La première façon consiste à spécifier un type de lien sur la base des formes de recouvrement observées entre des identités et des groupes. La deuxième façon distingue l’asymétrie et la symétrie dans les relations. Enfin, la troisième façon de différencier est fondée sur la force des liens. Les liens peuvent donc être de type multiplexe ou spécialisé, selon qu’ils associent différents registres ou non, les topologies de réseau pouvant être reconstruites à partir de ces différentes perspectives. Dans tous les cas, la notion de réseau qui émerge de cette approche est étroitement liée à de complexes formations narratives et peut servir aussi bien aux acteurs qu’aux observateurs pour rendre compte de la vie sociale.Networks and storiesSocial networks are not « pipes » connecting motionless entities. They are the result of control attempts by identities dealing with uncertainty, both in their social and bio-physical environments. These control attempts evoke stories from which links constituting networks are derived. A relation is thus interpreted through stories, not only by those who are embedded in them, but also by observers. Stories intermesh and yield assemblages in which regularities can be observed, notably three ways of distinguishing links. The first way is induced by overlaps among identities and groups. The second way is based on symmetry and asymmetry. Finally, the third way is related to the strength of ties. Therefore, links can be multiplex if they interlock different topics or specialized otherwise. Network topologies can be built on these different perspectives. In any case, the notion of network used in this approach is closely related to complex narratives and can be used by actors and observers alike to account for social life.Devenir histórico y redes socialesLos conjuntos sociales no están constituidos por « tubos » que unen entidades immobiles sinó que son el resultado del control ejercido por las diferentes identidades para afrontar la incertitud radical presente tanto en lo social como en el ámbito de lo biológico y de lo físico. Esta voluntad de control forja historias que originan conexiones que a su vez forman redes sociales. Por consiguiente, una relación es interpretada a través de esas historias, no solamente por los que participan en ellas sino también por los observadores. Las historias se mezclan entre ellas y acaban formando conjuntos con acontecimientos presentes cuya regularidad puede ser observada de tres maneras. La primera consiste en la especificación del tipo de conexión a partir de las formas que conforman las identidades y los grupos. La segunda consiste en distinguir la asimetría y la simetría de las relaciones. La tercera manera de diferenciar está asentada en la fuerza entre las diferentes conexiones. Las conexiones pueden ser de tipo complejo y múltiple o bien especializadas según que asocien diferentes ámbitos o no porque las topologías de las redes pueden ser reconstruidas a partir de esas diferentes perspectivas. En todos estos casos la noción de red  que emerge de esta aproximación está estrechamente ligada a complejos conjuntos narrativos y puede ser útil tanto para los participantes como para los observadores que describen y analizan las relaciones sociales.

  13. Espace, langues et cognition

    OpenAIRE

    Desclés, Jean-Pierre

    2004-01-01

    Le projet concerne les relations spatiales dans les langues (indo-européennes et non indo-européennes) et la recherche d'invariants ayant une portée cognitive. Pour formuler ces invariants il a été proposé d'utiliser le formalisme de la topologie. L'étape des données linguistiques (prépositions, préverbes et verbes de mouvement en particulier) nous a conduits à « étendre » la topologie classique et à jeter les fondements d'une théorie des « lieux abstraits » qui transcendent les relations spa...

  14. Vêtement et textile : sources et ressources

    Directory of Open Access Journals (Sweden)

    Sophie Jolivet-Jacquet

    2009-09-01

    Full Text Available Progressivement, les acteurs de la recherche scientifique s’organisent en réseaux, conscients que l’amélioration des connaissances passe par le partage et l’élaboration collective. L’outil internet offre une interface efficace, mais son offre est si multiple qu’elle mérite d’être organisée. L’histoire du vêtement, des matières et des accessoires textiles bénéficie désormais d’une interface spécifique à l’échelle de la recherche française, mais aussi internationale. Le projet « Vêtement et tex...

  15. Facteurs environnementaux et psychologiques et asthme infantile

    OpenAIRE

    Zhou, Cailiang

    2014-01-01

    Les objectifs de cette thèse est d'examiner l'hypothèses selon laquelle les caractéristiques psychologiques constituent modificateur de la relation entre l'exposition aux polluants atmosphériques et l'asthme infantile. A cet effet, nous avons utilisé les données de l'Etude des 6 villes avec dessein transversale, et l'étude de cohorte mère-enfant de type longitudinale EDEN (Étude sur les Déterminants pré et postnatalsdu développement de la santé l'ENfant) pour examiner cette hypothèse.Les donn...

  16. Final Focus Test Stand final report

    CERN Document Server

    Jeremie, A; Burrows, P

    2013-01-01

    Future Linear colliders will need particle beam sizes in the nanometre range. The beam also needs to be stable all along the beam line and especially at the Final Focus section. A dedicated Final Focus test stand has been used for this study and is comprised of several sub-parts. First there is the Stabilisation/Isolation system with sensors and actuators stabilizing down to sub-nanometre level. Then the Magnet itself needs to comply with very specific design constraints. In addition to the mechanical items, the beam can be stabilized acting on the trajectory directly and Beam-based controls have been developed and tested on different accelerator facilities.

  17. Cartographie et intelligence artificielle

    OpenAIRE

    Denise Pumain

    2005-01-01

    Le monde complexe dans lequel nous évoluons est aussi paradoxal : ainsi, que peut-on prédire quant à la diffusion du savoir faire des géographes en termes de cartographie et de visualisation de l’information géographique ? On voit surgir toujours plus d’instruments et d’occasions de se repérer et d’admirer des images de la terre, mais il n’est pas sûr que cela fasse progresser dans le public la connaissance des cartes et de leur interprétation. Prenons l’exemple du repérage, par GPS, et bient...

  18. Utilização do resíduo industrial ferkal na produção de mudas de Mimosa caesalpiniaefolia, em estéril de extração de argila, inoculadas com fungos micorrízicos arbusculares e rizóbio / Use of the industrial waste ferkal in the production of Mimosa caesalpiniaefolia seedlings, in degraded soil from clay extraction areas, inoculated with arbuscular mycorrhizal fungi and rhizobium

    Scientific Electronic Library Online (English)

    A. Z., Pralon; M. A., Martins.

    2001-03-01

    Full Text Available Realizou-se um experimento em casa de vegetação com o objetivo de avaliar os efeitos da inoculação com fungos micorrízicos arbusculares (FMAs) e, ou, rizóbio, associados à adição de resíduo da fabricação de ácido láctico (Ferkal), na produção de mudas de Mimosa caesalpiniaefolia (sabiá) em estéril d [...] e extração de argila. Foram utilizados vasos plásticos de 6 L que continham estéril de extração de argila, adicionado do resíduo Ferkal (nas concentrações de 0, 50, 100 e 200 g dm-3). Foram empregados seis tratamentos microbiológicos (FMAs nativos; FMA Glomus clarum; rizóbio; FMAs nativos + rizóbio; FMA G. clarum + rizóbio, e controle não inoculado). Após 103 dias, as mudas foram coletadas, e analisados o peso da matéria seca dos nódulos, a taxa de colonização micorrízica, o peso da matéria seca e os teores de N e P na parte aérea das mudas. Os resultados demonstraram que adição de Ferkal no tratamento-controle (sem inoculação) aumentou significativamente o teor de P. Entretanto, as melhores respostas foram obtidas nas mudas inoculadas com FMAs e, ou, rizóbio, que apresentaram, em relação ao controle, aumentos significativos no peso da matéria seca e nos teores de N e P da parte aérea das mudas, em quase todos os tratamentos inoculados. Os FMAs nativos foram mais eficientes que o FMA G. clarum em promover o crescimento de M. caesalpiniaefolia. Abstract in english An experiment was carried out under greenhouse conditions to evaluate the effects of arbuscular mycorrhizal fungi (AMF) and, or rhizobium inoculation, with the addition of industrial waste from lactic acid production (Ferkal), on the growth of Mimosa caesalpiniaefolia. Plastic pots of 6 L of capacit [...] y were used, filled with degraded soil from clay extraction areas with four levels of the Ferkal residue (0, 50, 100 and 200 g dm-3). Six microbiological treatments were conducted: indigenous AMF; AMF Glomus clarum; rhizobium; indigenous AMF + Rhizobium; AMF G. clarum + Rhizobium; and, non-inoculated control. The results were evaluated 103 days after planting by measuring AMF colonization; dry matter of nodules in the roots; weight of dry matter and N and P contents in the shoots. The results showed that the addition of Ferkal in the control treatment led to a significant increase in dry matter production and P content. However, the best results were observed in plants inoculated with AMF and, or Rhizobium, showing significant increases in dry weight and N and P content in the shoot, in almost all the inoculated treatments. The indigenous AMFs were more efficient than the G. clarum in promoting plant growth.

  19. Polyélectrolytes et liquides ioniques

    OpenAIRE

    Smolyakov, Georgiy

    2012-01-01

    Cette thèse présente une étude de la structure de solutions de polyélectrolytes (PEs) dans les liquides ioniques (LIs) et de la structure locale des LIs en présence de PEs. Les techniques de diffusion de rayons X et de neutrons ont été principalement utilisées pour cette étude. Dans une première partie, la capacité des LIs à former des " clusters " à l'échelle nanoscopique est démontrée. Dans une seconde partie, l'influence de la nature des contreions et du solvant sur le comp...

  20. Huntingtine et mitose

    OpenAIRE

    Molina-calavita, Maria

    2012-01-01

    La maladie de Huntington (MH) est une maladie neurodégénérative héréditaire autosomique dominante. Elle résulte d'une expansion anormale de glutamines (polyQ) dans la partie N-terminale de la protéine huntingtine (HTT ; codé par HTT). La MH est caractérisée par la dysfonction et la mort de cellules neuronales dans le cerveau, entraînant l'apparition de symptômes cognitifs, psychiatriques et moteurs, dévastateurs chez les patients. De nombreuses études sur des modèles animaux et...

  1. Innovation responsable et nanotechnologies

    OpenAIRE

    Thoreau, Franc?ois

    2011-01-01

    Dès le départ, le développement des nanotechnologies a été fortement soutenu par les pouvoirs publics et marqué par une vision particulière du futur de nos sociétés occidentales. C'est notamment pour cette raison que les sciences humaines et sociales (SHS) ont été conviées à participer à la réflexion autour des nanotechnologies, dans le cadre plus général (et concomitant) de l'innovation responsable. Que ce soit aux États-Unis ou en Europe, cette évolution s'est traduite pa...

  2. Fiction et forme encyclopédique : Wookieepedia, Dragon Ball Wiki et Cie.

    Directory of Open Access Journals (Sweden)

    Benoît Berthou

    2011-06-01

    Full Text Available Wookieepedia, Final Fantasy Wiki, Dragon Ball Wiki, Memory Alpha, WoWWiki… Autant d’encyclopédies en ligne abordant de célèbres fictions pour la jeunesse à travers un nombre parfois considérable d’articles abordant toutes sortes de sujets (récits, technologies, personnages, lieux, auteurs, fans…. Que nous apprennent ces dispositifs entendant prendre des fictions au sérieux, c’est-à-dire aborder un domaine relevant de l’imaginaire avec des outils relevant du domaine de la connaissance ? Deux pratiques se dégagent : la référence à des produits culturels prenant des formes fort diverses (romans, bandes dessinées, films, jeux vidéo… et le lien entre les divers articles. Ces deux pratiques montrent comment se développe une expertise quant à une fiction, une capacité à se situer dans une construction imaginaire.

  3. Aplicação de nitrogênio e inoculação com rizóbio em feijoeiro cultivado após milho consorciado com braquiária Nitrogen fertilization and rhizobium inoculation in common bean cultivated after corn intercropped with palisade grass

    Directory of Open Access Journals (Sweden)

    Emerson de Freitas Cordova de Souza

    2011-04-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de doses de nitrogênio (N e de inoculação de Rhizobium tropici em feijoeiro cultivado no sistema plantio direto, em sucessão ao milho safrinha consorciado com Urochloa brizantha (Syn. Brachiaria bryzantha ou Urochloa ruziziensis (Syn. Brachiaria ruziziensis. Dois experimentos foram conduzidos, durante dois anos agrícolas, em Latossolo Vermelho distroférrico. Utilizou-se o delineamento de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As parcelas foram constituídas pela inoculação ou não de R. tropici nas sementes, e as subparcelas por quatro doses de N (0, 35, 70 e 140 kg ha-1. Foram feitas avaliações quanto ao número de nódulos por planta, matéria seca de nódulos, teor de N na folha, matéria seca da parte aérea, N acumulado na parte aérea, número de vagens por planta e produtividade de grãos. As variáveis avaliadas, em geral, não foram influenciadas pela inoculação de R. tropici. O acréscimo das doses de N diminuiu a nodulação e aumentou a produção de matéria seca, o teor e o acúmulo de N da parte aérea do feijoeiro. A produtividade de grãos do feijoeiro foi pouco influenciada pela adubação nitrogenada.The objective of this work was to evaluate the effect of nitrogen (N doses and Rhizobium tropici inoculation on common bean grown under no-tillage system, after second-crop winter corn intercropped with Urochloa brizantha (Syn. Brachiaria bryzantha or Urochloa ruziziensis (Syn. Brachiaria ruziziensis. Two experiments were performed during two agricultural years, on a dystroferric Haplorthox. A randomized block design was used in split plots, with four replicates. The plots were constituted of absence or presence of seed inoculation with R. tropici, and the subplots were constituted of four N doses (0, 35, 70, and 140 kg ha-1. Evaluations were made for the number of nodules per plant, nodule dry matter, N-leaf content, shoot dry matter, shoot-accumulated N, number of pods per plant, and grain yield. The evaluated variables were not affected by seed inoculation with R. tropici. Increasing doses of N fertilization decreased nodulation, and increased dry matter yield, N content and N accumulation of common bean aerial parts. Common bean grain yield was little influenced by N fertilization.

  4. midD-encoded 'rhizomimosinase' from Rhizobium sp. strain TAL1145 is a C-N lyase that catabolizes L-mimosine into 3-hydroxy-4-pyridone, pyruvate and ammonia.

    Science.gov (United States)

    Negi, Vishal Singh; Bingham, Jon-Paul; Li, Qing X; Borthakur, Dulal

    2013-06-01

    Rhizobium sp. strain TAL1145 catabolizes mimosine, which is a toxic non-protein amino acid present in Leucaena leucocephala (leucaena). The objective of this investigation was to study the biochemical and catalytic properties of the enzyme encoded by midD, one of the TAL1145 genes involved in mimosine degradation. The midD-encoded enzyme, MidD, was expressed in Escherichia coli, purified and used for biochemical and catalytic studies using mimosine as the substrate. The reaction products in the enzyme assay were analyzed by HPLC and mass spectrometry. MidD has a molecular mass of ~45 kDa and its catalytic activity was found to be optimal at 37 °C and pH 8.5. The major product formed in the reaction had the same retention time as that of synthetic 3-hydroxy-4-pyridone (3H4P). It was confirmed to be 3H4P by MS/MS analysis of the HPLC-purified product. The K m, V max and K cat of MidD were 1.27 × 10(-4) mol, 4.96 × 10(-5) mol s(-1) mg(-1), and 2,256.05 s(-1), respectively. Although MidD has sequence similarities with aminotransferases, it is not an aminotransferase because it does not require a keto acid as the co-substrate in the degradation reaction. It is a pyridoxal-5'-phosphate (PLP)-dependent enzyme and the addition of 50 ?M hydroxylamine completely inhibited the reaction. However, the supplementation of the reaction with 0.1 ?M PLP restored the catalytic activity of MidD in the reaction containing 50 ?M hydroxylamine. The catalytic activity of MidD was found to be specific to mimosine, and the presence of its structural analogs including L-tyrosine, L-tryptophan and L-phenylalanine did not show any competitive inhibition. In addition to 3H4P, we also identified pyruvate and ammonia as other degradation products in equimolar quantities of the substrate used. The degradation of mimosine into a ring compound, 3H4P with the release of ammonia indicates that MidD of Rhizobium sp. strain TAL1145 is a C-N lyase. PMID:23462928

  5. Aplicação de nitrogênio e inoculação com rizóbio em feijoeiro cultivado após milho consorciado com braquiária / Nitrogen fertilization and rhizobium inoculation in common bean cultivated after corn intercropped with palisade grass

    Scientific Electronic Library Online (English)

    Emerson de Freitas Cordova de, Souza; Rogério Peres, Soratto; Felipe Augusto, Pagani.

    2011-04-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de doses de nitrogênio (N) e de inoculação de Rhizobium tropici em feijoeiro cultivado no sistema plantio direto, em sucessão ao milho safrinha consorciado com Urochloa brizantha (Syn. Brachiaria bryzantha) ou Urochloa ruziziensis (Syn. Brachiaria ruziz [...] iensis). Dois experimentos foram conduzidos, durante dois anos agrícolas, em Latossolo Vermelho distroférrico. Utilizou-se o delineamento de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As parcelas foram constituídas pela inoculação ou não de R. tropici nas sementes, e as subparcelas por quatro doses de N (0, 35, 70 e 140 kg ha-1). Foram feitas avaliações quanto ao número de nódulos por planta, matéria seca de nódulos, teor de N na folha, matéria seca da parte aérea, N acumulado na parte aérea, número de vagens por planta e produtividade de grãos. As variáveis avaliadas, em geral, não foram influenciadas pela inoculação de R. tropici. O acréscimo das doses de N diminuiu a nodulação e aumentou a produção de matéria seca, o teor e o acúmulo de N da parte aérea do feijoeiro. A produtividade de grãos do feijoeiro foi pouco influenciada pela adubação nitrogenada. Abstract in english The objective of this work was to evaluate the effect of nitrogen (N) doses and Rhizobium tropici inoculation on common bean grown under no-tillage system, after second-crop winter corn intercropped with Urochloa brizantha (Syn. Brachiaria bryzantha) or Urochloa ruziziensis (Syn. Brachiaria ruzizien [...] sis). Two experiments were performed during two agricultural years, on a dystroferric Haplorthox. A randomized block design was used in split plots, with four replicates. The plots were constituted of absence or presence of seed inoculation with R. tropici, and the subplots were constituted of four N doses (0, 35, 70, and 140 kg ha-1). Evaluations were made for the number of nodules per plant, nodule dry matter, N-leaf content, shoot dry matter, shoot-accumulated N, number of pods per plant, and grain yield. The evaluated variables were not affected by seed inoculation with R. tropici. Increasing doses of N fertilization decreased nodulation, and increased dry matter yield, N content and N accumulation of common bean aerial parts. Common bean grain yield was little influenced by N fertilization.

  6. Tassements référentiels sur la décharge réhabilitée d’Agadir et suivi des biogaz

    OpenAIRE

    Ahmed Elkadi; Mostapha Maatouk; Mohammed Raissouni; Tahiri Zakariyae Djebary; Abderrahim Mouhssine

    2014-01-01

    La recirculation et réinjection des lixiviats dans le corps des anciens déchets, après leurs couverture finale, est mise en œuvre à titre d’essai sur une partie de la décharge réhabilité pour accélérer la biodégradation de la matière organique, augmenter la production des biogaz et par conséquent favoriser d’avantage la stabilité du massif des déchets. Afin d’assurer une valorisation et une exploitation rationnelle, au niveau environnemental et économique, les biogaz pro...

  7. Topographie et topologie textuelles

    Directory of Open Access Journals (Sweden)

    Jean-Louis Lebrave

    2009-11-01

    Full Text Available Depuis ses débuts la statistique linguistique, y compris lorsqu’elle s’applique à l’étude des textes et des discours, a principalement recouru à des modèles qui tendent à négliger ce fait majeur qu’un texte est une structure ordonnée ; les dénombrements, les relevés de fréquences, les calculs de spécificités reposent tous sur le fameux schéma d’urne et renoncent à prendre en compte le positionnement dans le texte des unités dénombrées. Certes, les résultats ainsi obtenus sont généralement intéressants et bien interprétables, et ils ont largement contribué au développement et aux succès de la discipline. Mais ils se pourraient qu’ils soient en train d’atteindre leurs limites. Ou, du moins, de ne plus suffire pour donner entière satisfaction au chercheur. De plus en plus souvent en effet, ceux-ci souhaitent pouvoir établir, à côté de la dimension paradigmatique appréhendée par ce type de calculs statistiques traditionnels, la dimension syntagmatique des données textuelles, saisies à courte ou à longue portée : distribution régulière ou non d’une entité linguistique (mot ou catégorie grammaticale susceptible d’arriver à intervalles à peu près égaux ou, au contraire, en paquets plus ou moins denses ; répartition d’un élément au fil du texte, selon la structure globale de celui-ci et ses parties constituantes ; phénomènes d’échos et d’alignements dans la mise en parallèle de deux textes ou deux portions de textes ; etc. Bien sûr, des travaux, dont certains sont déjà anciens, ont abordé ces questions : parmi les plus connus citons tous ceux d’A. Salem qui ont établi la pertinence de la fameuse notion de « segment répété » et qui ont mis en place les outils pour les repérer et les analyser ; citons aussi les travaux de P. Lafon sur les « rafales » et son article "Statistique des localisations des formes d’un texte" paru en 1984 dans la revue Mots ; ou encore l’article de D. Sérant et Ph. Thoiron sur la « topographie des formes répétées » (Revue Informatique et Statistique dans les Sciences humaines 24, pp. 333-343 ; etc. Actuellement, cette question reprend de l’acuité et les études, ainsi que les développements logiciels afférents, se multiplient. Le moment nous semble donc venu de faire le point. Ce numéro de Lexicometrica accueillera donc exclusivement des contributions consacrées aux notions de topographie et topologie textuelles, c’est-à-dire à la prise en compte, dans les exploitations automatiques des textes numérisés et dans leur traitement quantitatif de la linéarité intrinsèque du texte, voire de sa structure en réseau avec d’autres textes au sein d’un corpus fortement cohérent (cas des recueils par exemple.

  8. Théorie de la justice et idéologie : Hume et Rawls

    Directory of Open Access Journals (Sweden)

    Eléonore Le Jallé

    2008-04-01

    Full Text Available Les points d’accord entre Rawls et Hume vont au-delà du seul repérage des « circonstances de la justice ». Même si Hume se trouve attaché à la théorie utilitariste de l’impartialité que Rawls rejette, Hume n’est pas, selon Rawls, « à proprement parler » utilitariste : il a su reconnaître l’idée selon laquelle les institutions doivent fonctionner dans l’intérêt de chacun. L’idée d’une coopération sociale en vue de l’avantage mutuel est donc commune à ces deux auteurs. Ils partagent, en outre, une attitude similaire face au « problème de la confiance » en lien avec la stabilité de la justice : l’un et l’autre ajoutent ainsi à la solution extérieure qu’est l’institution étatique, un facteur intrinsèque de stabilité, à savoir, le sens de la justice. L’idée de « justice procédurale » et le rejet, corrélatif, d’un critère indépendant du juste, les relie également ; d’où, enfin, une certaine analogie des critiques respectivement adressées à ces deux auteurs.The specification of the “circumstances of justice” is not the only point on which Rawls agrees with Hume. If Rawls rejects the utilitarian theory of impartiality which is “reminiscent of Hume”, he does not consider him as “strictly speaking utilitarian”. Indeed, Rawls thinks that Hume has well understood that institutions have to be to the advantage of everyone. Besides, Hume and Rawls agree in thinking that the stability of justice involves a public sense of justice. Finally, the idea of “pure procedural justice” is shared by these authors: both have rejected any independent criterion for the right result, so that the ways they were criticized are rather similar.

  9. Characterization of Rhizobial Isolates of Phaseolus vulgaris by Staircase Electrophoresis of Low-Molecular-Weight RNA

    OpenAIRE

    Vela?zquez, Encarna; Marti?nez-romero, Esperanza; Rodri?guez-navarro, Dulce Nombre; Trujillo, Martha E.; Daza, Antonio; Mateos, Pedro F.; Marti?nez-molina, Eustoquio; Berkum, Peter

    2001-01-01

    Low-molecular-weight (LMW) RNA molecules were analyzed to characterize rhizobial isolates that nodulate the common bean growing in Spain. Since LMW RNA profiles, determined by staircase electrophoresis, varied across the rhizobial species nodulating beans, we demonstrated that bean isolates recovered from Spanish soils presumptively could be characterized as Rhizobium etli, Rhizobium gallicum, Rhizobium giardinii, Rhizobium leguminosarum bv. viciae and bv. trifolii, and Sinorhizobium fredii.

  10. Des racines et des ailes

    Directory of Open Access Journals (Sweden)

    Stéphanie Vincent-Geslin

    2012-05-01

    Full Text Available Les mobilités pendulaires semblent être en augmentation en Europe depuis une dizaine d’années. Cette croissance du temps passé à se déplacer amène à remettre en question la conjecture de Zahavi et apparaît relativement inexplicable en regard du paradigme classique de l’acteur rationnel traditionnellement utilisé dans le champ des transports. Si, dans la littérature, les temps de déplacements sont principalement expliqués par le contexte résidentiel, la forme urbaine et le travail, ce cadre explicatif ne dit rien des processus de décision eux-mêmes qui amènent aux pendularités intensives.À partir d’une enquête qualitative menée auprès de pendulaires français, suisses et belges, cette contribution propose d’analyser les arbitrages et les éléments déterminants des processus de la grande pendularité. Les mobilités quotidiennes pendulaires apparaissent comme le résultat de compromis entre activité professionnelle, attachement résidentiel et choix de vie et prennent ainsi la forme de stratégies de conciliation entre vie privée et vie professionnelle. Ces mobilités spatiales permettent alors paradoxalement la préservation des ancrages résidentiels, sociaux et familiaux.Roots and wings. Long-distance commuting patterns, or how to conciliate professional and personal lifeLong-distance commuting patterns appear to be increasing in Europe over the last ten years. These raising mobility patterns lead to reappraise the Zahavi conjecture and appear largely inexplicable by the classical rational actor paradigm traditionally used in transportation research. In literature, commuting is mainly explained by residential contexts, urban forms and job. Nevertheless this theoretical frame says little about the decision-making processes themselves. Based on a qualitative survey conducted in three European countries - France, Belgium and Switzerland – among a population of high commuters, this paper proposes an analysis of trade-off and elements implied in the decision-making process of becoming a long-distance commuter. Intense commuting patterns appear to be the result of compromises between job career, residential attachment and life choices. Thus they may be a “happy medium” that allows to conciliate professional and personal life. Finally these spatial mobilities paradoxically allow to preserve residential, social and family anchors.De raíces y de alas. La movilidad pendular como estrategia de conciliación entra la vida privada y la vida profesionalLas movilidades pendulares parecen aumentar en Europa desde hace una década. Esta aumentación del tiempo consagrado a los desplazamientos nos lleva a poner en entredicho la conjetura de Zahavi porque es relativamente inexplicable con relación al paradigma clásico del actor racional, habitualmente utilizado en el ámbito de los transportes. Si en los diferentes estudios realizados el tiempo utilizado en los transportes es explicado por el contexto de la residencia, la forma urbana y el trabajo, este marco explicativo no evoca siquiera los procesos de decisión que inducen pendularidades intensivas. A partir de una encuesta cualitativa llevada a cabo sobre grupos « pendulares » franceses, suizos y belgas, esta contribución propone el análisis de las mediaciones y de los elementos determinantes en estos procesos. Las movilidades cotidianas pendulares son una manera de asumir el compromiso entre actividad profesional, lugar de residencia y elección de modo de vida y toman la forma de estrategias de conciliación entre lo privado y lo profesional. Estas movilidades espaciales permiten paradójicamente de preservar el enraizamiento residencial, profesional y familiar.

  11. Graphisme et géométrie

    CERN Document Server

    Fleury, Michel

    1986-01-01

    Une introduction à l'étude des rythmes visuels d'un point de vue géométrique et algorithmique. L'auteur montre le rôle de l'informatique dans la réalisation des dessins rythmiques et explique que la variété des rythmes visuels s'ordonne en classes distinctes associées à des algorithmes de production.

  12. Fødselsdagsfest for et monument

    DEFF Research Database (Denmark)

    Kristensen, Peter Thule

    2013-01-01

    Som et led i fejringen af 40 året for Sydney Opera House udstilledes dansk design i operafoyeren, danske arkitekter og designere bidrog til symposiet Architecture Makes the City og der lanceres et studenterudvekslingsprogram Made by The Opera House. Artiklen er en reportage fra arrangementerne.

  13. Jeux et enjeux olympiques

    Directory of Open Access Journals (Sweden)

    Pierre LEBLANC

    1989-06-01

    Full Text Available Les actes de candidatures et de choix des villes pour l'organisation des différentes sessions des Jeux Olympiques contemporains ne sont pas le fruit du hasard. Dans l'un et l'autre cas, il s'agit d'actes dont la signification s'inscrit dans le contexte politique du moment.

  14. Transacsys PLC - Final Results

    CERN Multimedia

    2002-01-01

    Final results from Transacsys PLC. A subsidary of this company was set up to develop the CERN EDH system into a commercial product but incurred too much financial loss so the project was cancelled (1/2 page).

  15. Final focus test beam

    International Nuclear Information System (INIS)

    This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration

  16. Aurora final report

    Energy Technology Data Exchange (ETDEWEB)

    Robert, Dross; Amedeo, Conti

    2013-12-06

    Final Technical report detailing the work done by Nuvera and its partners to fulfill the goals of the program "Transport Studies Enabling Efficiency Optimization of Cost-Competitive Fuel Cell Stacks" (a.k.a. AURORA)

  17. Final Disposal of LLRW

    International Science & Technology Center (ISTC)

    Investigations in the Field of Long-Lived Radioactive Waste Final Disposal in Geological Formations. An Assessment of the Possibility of the RT-2 Plant Radioactive Waste Disposal in Rocks of the Yenisei Ridge.

  18. Radioprotection et ingénierie nucléaire

    CERN Document Server

    2006-01-01

    Le développement de l'énergie nucléaire repose sur deux piliers essentiels : la sûreté nucléaire, qui concerne la machine, et la radioprotection, qui se préoccupe des hommes. Construit de manière fiable, un réacteur nucléaire se doit d'irradier le moins possible ses opérateurs et conduire à un impact très faible pour les populations avoisinantes. Tout cela est soumis à des règles strictes, élaborées au niveau international, et qui ne tolèrent aucun écart. Les ingénieurs qui ont à concevoir, construire et conduire ces machines doivent maîtriser les règles de protection : cet ouvrage leur est destiné. La radioprotection, si elle se fonde principalement sur des bases scientifiques, intègre également une dimension sociétale exigeante. Ces activités sont en effet sous le regard critique et permanent de nos concitoyens, qui exigent des acteurs de cette industrie une maîtrise totale de la radioprotection ; un ingénieur qui ne connaîtrait pas la genèse de la radioprotection, ses règle...

  19. Enfants, chercheurs et citoyens

    CERN Document Server

    Lederman, Leon

    1998-01-01

    J'ai consacré ma vie à la physique. J'aimerais que tous les enfants aient la chance de satisfaire leur goût pour la recherche et de développer leur intelligence. J'ai découvert à Chicago, chez mon ami Leon Lederman, une méthode d'enseignement des sciences à l'école qui m'a subjugué. J'ai vu, à tous les niveaux, en physique, en chimie, en sciences naturelles et en mathématiques, des enfants qui expérimentaient avec joie, apprenaient les concepts fondamentaux à leur rythme, réfléchissant et discutant. Je voyais en gestation des êtres libres, capables de rechercher une vérité qui ne leur était pas assenée. J'ai voulu confronter des enseignants français du primaire et du secondaire à ces recherches qui ne se limitent pas à l'enseignement primaire. C'est leur regard critique et surtout leurs idées pour notre enseignement que j'ai rassemblés dans ce livre.

  20. Lectin from Canavalia brasiliensis Seeds (ConBr Is a Valuable Biotechnological Tool to Stimulate the Growth of Rhizobium tropici in Vitro

    Directory of Open Access Journals (Sweden)

    Ricardo Pires dos Santos

    2012-05-01

    Full Text Available To study the interactions between a Rhizobium tropici strain and lectins isolated from the seeds of Canavalia ensiformis (ConA and Canavalia brasiliensis (ConBr, a lectin fluorescence assay was performed. In addition, an experiment was designed to evaluate the effect of the two lectins on bacterial growth. Both lectins were found to bind to R. tropici cells, but the interactions were inhibited by D-mannose. Interestingly, only ConBr stimulated bacterial growth in proportion to the concentrations used (15.6–500 µg/mL, and the bacterial growth stimulation was inhibited by D-mannose as well. Structure/Function analyses by bioinformatics were carried out to evaluate the volume and carbohydrate recognition domain (CRD configuration of ConA and ConBr. The difference of spatial arrangement and volume of CRD may indicate the variation between biological activities of both lectins. The results suggest that ConBr could be a promising tool for studies focusing on the interactions between rhizobia and host plants.

  1. Drague et cruising

    Directory of Open Access Journals (Sweden)

    Emmanuel Redoutey

    2008-04-01

    Full Text Available Dans la culture homosexuelle masculine, drague et cruising sont des termes équivalents. Ils désignent la quête d’un ou de plusieurs partenaires occasionnels et anonymes. Analyser leurs référents métaphoriques respectifs offre un éclairage particulier, à la fois phénoménologique et géographique, pour une compréhension nuancée des types de pratique et d’expérience qu’ils recouvrent. Cet article pose l’hypothèse d’une distinction entre deux figures, le dragueur et le cruiser, et postule que cette distinction se tient essentiellement dans l’opposition que Gilles Deleuze et Félix Guattari établissent entre ‘espace strié’ et ‘espace lisse’. L’essai de théorisation qui en découle est une manière de comprendre ce qui, entre sexualisation de l’espace et érotisation d’un mouvement exploratoire, fait fonctionner le script de la drague.In French gay culture, drague means cruising: looking for anonymous and ?casual sexual partners. This paper, by respectively examining the ?metaphorical underpinnings of both words, French and English, throws ?doubt on the validity of this translation. Through a phenomenological ?and geographical perspective, it attempts to give a nuanced examination ?of the practice and experience that each word conceals. The aim is to ?identify two figures embodied in a same person: the dragueur and the ?cruiser. I will argue that the distinction mainly rests on the ?opposition that Gilles Deleuze and Felix Guattari establish between ‘striated space’ and ‘smooth space’. The concluding theorical ?discussion is an attempt to understand what, in the tension between sexualization of space and eroticization of movement, guides the scripts of drague and cruising.

  2. Coeur et balancement dépendant: théorie et applications

    OpenAIRE

    Iehle?, Vincent

    2004-01-01

    Cette thèse est composée de quatre articles. L'objet principal de la thèse est d'énoncer des conditions suffisantes de non vacuité pour le coeur dans les jeux sans paiements latéraux. Rappelons que, dans un système social où des comportements coopératifs entrent en jeu, le coeur est l'ensemble qui vérifie des propriétés naturelles de stabilité et de rationalité. Pour assurer la non vacuité, les principaux résultats de la littérature supposent qu'une condition de balancement s...

  3. Artaud et les Tarahumaras

    Directory of Open Access Journals (Sweden)

    Marta Mariasole Raimondi

    2008-01-01

    Full Text Available Ce film propose des scènes de vie des Tarahumaras, une ethnie originaire du Mexique installée dans le territoire de l'Etat de Chiuahua, dans un milieu montagneux très sauvage. La caméra reprend les danses et les rites de ces mangeurs de peyotl d'un regard rapide et saccadé primant des cadrages de détail où prédominent les pieds, pour nous montrer ces corps d'homme et de femme en mouvement, courant, dansant, bondissant au milieu des leurs éléments naturels : rocailles, rivières, rochers, sans...

  4. Villes et nouvelle économie

    Directory of Open Access Journals (Sweden)

    Emmanuel Éveno

    2003-06-01

    Full Text Available Cet article analyse les modes d’insertionspatiale des technologies de l’information et de la communication (TIC dans les métropoles puis aborde la question des mythes d’une «antigéographie» soulevés par cette nouvelle vague d’innovations dont les postulats sont basés sur les effets de réseaux et les technologies de lutte contre la distance. Trois approches (hiérarchie urbaine, réorganisation de l’espace métropolitain, nouveaux objets urbains essaient de montrer toute la place de la géographie et des problématiques territoriales autour des TIC.

  5. Progressive utterance-final lengthening in syllables with final fricatives.

    Science.gov (United States)

    Berkovits, R

    1993-01-01

    The generality of the pattern of progressively greater lengthening within the utterance-final syllable, previously found with respect to final stops, is shown to extend to syllables in Hebrew with final fricatives. Seven native speakers of Hebrew read matched sentence pairs in which bisyllabic key words appeared in non-final and sentence-final position. Final fricatives showed almost four times as much utterance-final lengthening as the preceding stressed vowel. Final lengthening affected the duration of each segment of the final syllable, and also extended to the initial unstressed syllable of the final word. Though final fricatives showed more lengthening in sentence-final position than final-stop closures, no difference was found in the lengthening of the vowels preceding these consonants. The greater lengthening of the final fricative relative to the preceding vowel resulted in C/V ratios which failed to distinguish between the voiceless fricative in non-final position and the voiced fricative in utterance-final position. These results suggest that sentence position is taken into account in the perception of voicing, such that the C/V ratio applicable in non-final position is increased by a factor of two in final position. PMID:8345773

  6. Contributions to final storage

    International Nuclear Information System (INIS)

    The Editor: atw 12(2005) featured three separate articles dealing with the summary report compiled by the German Federal Office for Radiation Protection (BfS) about Conceptual and Technical Safety Issues of the Final Storage of Radioactive Waste - Comparison of Host Rock Varieties, and with the way that report had been written. The report incorporated the findings of 12 expert opinions dealing with twelve questions formulated by the Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety (BMU) about the final storage of radioactive waste. The contribution in this issue of atw by Dr. Ulrich Kleemann (BfS), who is also the author of one of the articles in atw 12(2005), comments upon the other two contributions under the title of 'Science Torn between Interests - a Contribution to the Discussion about Aspects of Technical Safety in Final Storage'. (orig.)

  7. Peirce et Wittgenstein

    OpenAIRE

    Tiercelin, Claudine

    2000-01-01

    Analyse des nombreux points communs mais aussi des différences réelles entre les deux auteurs, notamment sur la question de l'éthique, du pragamtisme, de la psychologie, mais aussi de la métaphysique et de la science.

  8. Grorum. Et demonstrationsprojekt

    DEFF Research Database (Denmark)

    Traberg-Borup, Steen

    1987-01-01

    Meddelelsen beskriver udforming og indretning af et grorum opført af fabriksfremstillede komponenter. Alle klimaskærmens dele, dvs. gulv, vægge, loft og dør gennemgås med udførlige bygningstegninger. Desuden beskrives ventilationsanlægget, belysningsanlægget og det specielt udviklede reolsystem.

  9. Education et Libération

    CERN Multimedia

    Jean-Pierre Lagnaux

    2013-01-01

    Vente d’artisanat du Tiers Monde Jeudi 23 et vendredi 24 mai 2013 CERN, Bâtiment principal Togo, Ecole Arc en ciel, construction des salles de classe. Appel pour le financement de ce chantier afin de libérer l’école de la charge des loyers payés pendant des années. Après nos réalisations en Amérique latine et au Bénin, nous mobilisons nos efforts pour l’école Arc en ciel de Kpeme, au Togo, sur les bords de l’Océan, à mi-chemin entre Lome et la frontière entre le Bénin et le Togo. Il s’agit d’une école primaire privée, laïque qui a très bonne réputation en termes de résultats, notamment pour les écoliers  en fin de scolarité primaire. Cela fait plusieurs années déjà que no...

  10. Éducation et Libération

    CERN Multimedia

    Jean-Pierre Lagnaux

    2012-01-01

    Vente d’artisanat du Tiers Monde Jeudi 22 et Vendredi 23 novembre de 10 heures à 16 heures 30 Après nos réalisations en Amérique latine et au Bénin, nous mobilisons nos efforts pour l’école Arc-en-ciel de Kpeme, au Togo, sur les bords de l’Océan, à mi-chemin entre Lome et la frontière entre le Bénin et le Togo. Il s’agit d’une école primaire privée, laïque qui a très bonne réputation en termes de résultats, notamment pour les écoliers en fin de scolarité primaire. Cela fait plusieurs années déjà que nous soutenons cette école. L’école est inscrite dans la liste des  Collectes à long terme  de l’Association du personnel du CERN depuis 2011. Selon les  R&am...

  11. Éducation et Libération

    CERN Multimedia

    Education et Libération

    2013-01-01

    Vente d’artisanat du Tiers Monde Mardi 29 et mercredi 30 octobre 2013 CERN, Bâtiment principal Togo, Ecole Arc en ciel, construction des salles de classe. Appel pour le financement de ce chantier afin de libérer l’école de la charge des loyers payés pendant des années. Après nos réalisations en Amérique latine et au Bénin, nous mobilisons nos efforts pour l’école Arc en ciel de Kpeme, au Togo, sur les bords de l’Océan, à mi-chemin entre Lome et la frontière entre le Bénin et le Togo. Il s’agit d’une école primaire privée, laïque qui a très bonne réputation en termes de résultats, notamment pour les écoliers  en fin de scolarité primaire. Cela fait plusieurs années déjà q...

  12. Éducation et libération

    CERN Multimedia

    Jean-Pierre Lagnaux

    2010-01-01

    26 – 27 avril 2010, de 10 h 00 à 16 h 30 Bâtiment principal Vente d’objet du Tièrs-Monde présentés par EDUCATION et LIBERATION L’Afrique, essentiellement nos engagements au Bénin et au Togo, constitue aujourd’hui notre souci principal. 1. Au Bénin, nous avons pu poursuivre sur notre lancée et soutenons activement la mise en valeur du terrain où notre partenaire fait pousser du manioc, du maïs et des ananas bio. La crise économique qui a frappé le monde depuis 2008, a touché l’Afrique plus durement que l’Europe ou les Etats-Unis d’Amérique mais on a pris l’habitude de penser que c’est normal : on y meurt de toute façon beaucoup plus vite. En particulier : on y meurt beaucoup de faim....

  13. Haine et colère

    OpenAIRE

    Baider Fabienne

    2012-01-01

    Dans la discussion qui suit sa définition de « anger » (colère), Wierzbicka (1998) propose l’élément de vengeance (‘revenge’) : «outrage may be followed by revenge ». Pourtant la vengeance semble justement un des éléments définitoires de la haine selon des recherches en corpus. La présente étude propose d’explorer la proximité sémantique des deux concepts colère et haine dans la culture et la société franco-françaises pour les définir dans une définition MSN. Nous...

  14. Science et Connaissance

    OpenAIRE

    Michel Bénot, Dr.Eng.

    2004-01-01

    On peut dire que la science moderne est née au 17ème siècle avec les contributions décisives de Galilée, en particulier la distinction qu’il a contribué à établir entre discours scientifique et discours théologique. Avant lui en effet, dans la tradition du monde chrétien, depuis les début de l’ère chrétienne jusqu’à la Renaissance, ces discours étaient intimement mêlés : la connaissance intuitive qui fait accéder aux Principes premiers et la connaissance rationnelle ont permis le développemen...

  15. Jeux, graphes et propagation

    OpenAIRE

    Dorbec, Paul

    2013-01-01

    Ce manuscrit d'Habilitation à diriger des recherches décrit mes travaux de recherche récents en théorie des graphes et en théorie des jeux combinatoires. Une première partie est consacrée à l'étude de paramètres de graphes en s'intéressant particulièrement aux contraintes structurelles qui permettent d'améliorer les bornes connues. Dans cette partie, nous traitons notamment la paire-domination, la domination indépendante mais aussi les partitions en cographes et les colorations quasi propres....

  16. Finale Notepad 2002

    Science.gov (United States)

    Finale Notepad 2002 is a nifty musical notation tool offered for free download by Coda Music Technology. Available for both Windows and Macintosh, the software enables sheet music creation on the computer via user-friendly interfaces, intuitive wizards, and simple icons. For musicians that need a simple software package to write and compose music, Finale Notepad 2002 will probably function adequately. A great feature that should aid the composition process is a playback feature that reads and plays musical notation, sounding much like a traditional, no frills MIDI player. Users with low bandwidth should be wary of the bulky file size, though; the Macintosh version was roughly 7 MB.

  17.  Final review of the Séralini et al. (2012a publication on a 2-year rodent feeding study with glyphosate formulations and GM maize NK603 as published online on 19 September 2012 in Food and Chemical Toxicology

    Directory of Open Access Journals (Sweden)

    European Food Safety Authority

    2012-11-01

    Full Text Available On 19 September 2012, Séralini et al. published online in the scientific journal Food and Chemical Toxicology a publication describing a 2-year feeding study in rats investigating the health effects of genetically modified maize NK603 with and without Roundup WeatherMAX® and Roundup® GT Plus alone (both are glyphosate-containing plant protection products. As requested by the European Commission, EFSA reviewed this publication taking into consideration assessments conducted by Member States and any clarification given by the authors. The assessments of Member States and EFSA revealed an overall agreement. The study as reported by Séralini et al. was found to be inadequately designed, analysed and reported. The authors of Séralini et al. provided a limited amount of relevant additional information in their answer to critics published in the journal Food and Chemical Toxicology. Taking into consideration Member States’ assessments and the authors’ answer to critics, EFSA reaches similar conclusions as in its first Statement (EFSA 2012. The study as described by Séralini et al. does not allow giving weight to their results and conclusions as published. Conclusions cannot be drawn on the difference in tumour incidence between treatment groups on the basis of the design, the analysis and the results as reported. Taking into consideration Member States’ assessments and the authors’ answer to critics, EFSA finds that the study as reported by Séralini et al. is of insufficient scientific quality for safety assessments. EFSA concludes that the currently available evidence does not impact on the ongoing re-evaluation of glyphosate and does not call for the reopening of the safety evaluations of maize NK603 and its related stacks. EFSA’s evaluation of the Séralini et al. article is in keeping with its role to review relevant scientific literature for risk assessment on an ongoing basis to ensure that the advice it provides is up-to-date.

  18. Regional final energy consumptions

    International Nuclear Information System (INIS)

    This report comments the differences observed between the French regions and also between these regions and national data in terms of final energy consumption per inhabitant, per GDP unit, and per sector (housing and office building, transport, industry, agriculture). It also comments the evolutions during the last decades, identifies the most recent trends

  19. Fuel Cell Final Exam

    Science.gov (United States)

    This final exam could be used at the end of a class or unit on fuel cell technology. The test consists of multiple choice, true/false, fill in the blank and short answer questions. This document may be downloaded in Microsoft Word DOC file format.

  20. Deep inelastic final states

    International Nuclear Information System (INIS)

    In these lectures we attempt to describe the final states of deep inelastic scattering as given by QCD. In the first section we shall briefly comment on the parton model and give the main properties of decay functions which are of interest for the study of semi-inclusive leptoproduction. The second section is devoted to the QCD approach to single hadron leptoproduction. First we recall basic facts on QCD log's and derive after that the evolution equations for the fragmentation functions. For this purpose we make a short detour in e+e- annihilation. The rest of the section is a study of the factorization of long distance effects associated with the initial and final states. We then show how when one includes next to leading QCD corrections one induces factorization breaking and describe the double moments useful for testing such effects. The next section contains a review on the QCD jets in the hadronic final state. We begin by introducing the notion of infrared safe variable and defining a few useful examples. Distributions in these variables are studied to first order in QCD, with some comments on the resummation of logs encountered in higher orders. Finally the last section is a 'gaullimaufry' of jet studies

  1. Final 2000 -- Make up

    Science.gov (United States)

    Muhamet Yildiz

    Final examination for a class at MIT covering game theory and its application to economics. The exam is one-hour-and-twenty minutes and intended to be open-book. It has four multi-part free response questions focusing on game theory as a solution to economic questions.

  2. Space Station Final Configuration

    Science.gov (United States)

    1994-01-01

    An artist's conception of what the final configuration of the International Space Station (ISS) will look like when it is fully built and deployed. The ISS is a multidisciplinary laboratory, technology test bed, and observatory that will provide an unprecedented undertaking in scientific, technological, and international experimentation.

  3. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Chris [Altamont Environmental, Inc.

    2014-11-13

    The project, ?Capital Investment to Fund Equipment Purchases and Facility Modifications to Create a Sustainable Future for EnergyXchange? served to replace landfill gas energy with alternative energy resources, primarily solar and wood waste. This is the final project closeout report.

  4. Entre exotisme et nostalgie

    Directory of Open Access Journals (Sweden)

    Caroline Rozenholc

    2008-03-01

    Full Text Available En 1992, la municipalité de Tel-Aviv Jaffa, sollicitée par un groupe d’habitants, décide d’investir dans le quartier de Florentin. Florentin est alors un des quartiers les plus pauvres de la ville et témoigne, comme l’ensemble de la zone administrative sud, d’un état de forte dégradation. En quelques décennies, le quartier aura en effet été littéralement déserté par sa population, laissant vacants des centaines de logements progressivement investis par de petites industries. Le potentiel du quartier est pourtant évident – architecture unique et forte densité commerciale – et les réhabilitations réussies des quartiers de Neve Tseddek et de Sheinkin encouragent les autorités à « remettre Florentin sur la carte ». Cinq ans plus tard, Eytan Fox – plus connu aujourd’hui pour son film « The Bubble » – prend le quartier comme toile de fond pour réaliser une chronique de la jeunesse israélienne : « Florentin ». Pendant trois ans, cette série télévisée va obtenir une audience nationale confirmée par une rediffusion récente. Florentin est alors consacré comme un espace « à part » et devient emblématique d’une urbanité alternative. Paré d’une aura d’exotisme, renforcée par la présence de nombreux migrants africains, Florentin devient ainsi le lieu d’une certaine culture israélienne : celle d’une génération ouverte à l’altérité et qui, tout en étant ancrée dans la réalité du pays, se projette au-delà de ses frontières. Mêlant sens et temporalités, une conjoncture particulière fait donc émerger Florentin comme un label ; vivre à Florentin devient une véritable « déclaration d’intention ».En transition vers une gentrification évidente, comment ce quartier, longtemps marginalisée et qui n’est inclus dans les limites administratives de Tel-Aviv que depuis les années 50, en est venu à former une entité à part entière au sein de l’agglomération et à promouvoir l’identité globalisée de la ville ? Pour répondre à cette question, et pour contribuer à celle plus vaste de l’attachement au lieu dans la mondialisation, Florentin sert d’ancrage à une réflexion sur le quartier qui permet d’alimenter, entretiens et observations à l’appui, le débat entre tenants de l’hyper-mobilité et des nons-lieux et ceux d’une territorialité au fondement de la géographie et de l’urbanité. Florentin, espace complexe et stimulant, et dont on peut multiplier les « entrées », semble alors indiquer une troisième voie ; celle d’un lieu défini et ouvert où s’articulent, sans s’effacer, des temporalités et des perceptions du lieu distincts et propres, même si parfois partagées, à chacun.Florentin between exoticism and nostalgia.Globalization of an 'authentic' neighborhoodAt the beginning of the 90s, the Municipality of Tel-Aviv, approached by a small group of inhabitants of Florentin neighborhood, decides to invest in it. Florentin, at the time, is one of the poorest areas of the city and alike the whole South of Tel-Aviv, it is in an advanced state of deterioration. Over the last twenty years, buildings had fallen apart and all the population who had opportunities to leave the neighborhood found better dwellings. At the time, the potential of the neighborhood is nevertheless clear to the authorities – due to its peculiar architecture and the interesting mixture of residential and commercial activities – and the successful rehabilitations of both Neve Tseddek (the first Jewish neighborhood out the walls of the ancient Jaffa and Sheinkin street (today a very hype place to hang out stimulate the Municipality to “put Florentin back on the map”. This is a radical step as for few decades Florentin remained very much at the margins of the city, in between Tel-Aviv and Jaffa, only loosing population and gaining in polluting activities, such as small industries and manufactures. After few years of drastic investments, and due to an economical crisis, all initiatives remain pendin

  5. Associative Effect of Phosphate Dissolving Fungi, Rhizobium and Phosphate Fertilizer on Some Soil Properties, Yield Components and the Phosphorus and Nitrogen Concentration and Uptake by Vicia faba L. Under Field Conditions

    Directory of Open Access Journals (Sweden)

    T.A. Mehana

    2002-01-01

    Full Text Available The effect of interactions between three phosphate-dissolving fungi (PDF (Aspergillus niger, A. fumigatus and Penicillium pinophilum and Rhizobium leguminosarum biovar viciae (RH was studied on some soil chemical properties, phosphorus and nitrogen uptake and yield of faba beans (Vicia faba L.. Analysis of the soil after crop harvest indicated that the inoculation with PDF and RH significantly increased the levels of soil available P, mineral N (NH4+-N+ NO- 3-N as compared to the untreated soil. The highest level of available P was recorded under the treatment RH1 + 31 Kg P2O5 fed-1 + P. pinophilum. The highest value of soil total N was observed with the treatment RH1 + 15.5 kg P2O5 fed-1 + A. niger. Values of soil pH and total N were not significantly affected by the soil inoculation with PDF. The inoculation with RH and PDF significantly increased seeds and straw yields of faba beans as compared to the untreated plants. The maximum seeds and straw yields of 1272 and 1871 Kg fed-1 respectively, were achieved in the treatment RH1 + 31 Kg P2O5 fed-1 + P. pinophilum. The highest P uptake by plants was also achieved under the same treatment. The highest N uptake was recorded with the combination RH1 + 31 Kg P2O5 fed-1 + A. fumigatus. It was clearly evident that the ordinary used quantity of SP fertilizer could be reduced by 50%, in the presence of PDF, without any significant effect on the yield of Vicia faba (L..

  6. Activités estivales et automnales

    CERN Multimedia

    Staff Association

    2013-01-01

    Recharger les batteries et bien plus encore…. Les vacances d’été sont l’occasion idéale de passer plus de temps avec sa famille, de découvrir de nouveaux pays, se faire de nouveaux amis, autrement dit de passer du temps loin de la routine quotidienne. Cette recharge de batteries est essentielle à notre équilibre travail-vie privée, et le CERN, employeur moderne et socialement responsable, en a fait un élément central de sa politique de ressources humaines. Néanmoins, n’oublions pas que même si beaucoup d’entre vous profitent d’une pause estivale bien méritée, certains de nos collègues travaillent dur pour faire du LS1 (premier long arrêt du LHC) un succès afin de garantir que le LHC pourra, dès 2015, commencer à produire des données de physiq...

  7. Crise, métropolisation, et aménagement

    Directory of Open Access Journals (Sweden)

    Jean-Albert Guieysse

    2014-12-01

    Full Text Available Ce texte développe une conférence tenue à Notre-Dame-des-Landes, lors du rassemblement, le 4 août 2013, des opposants au projet d’un aéroport international pour la métropole de Nantes. La métropolisation, telle que présentée à l’opinion publique, est l’avenir urbain de l’humanité. Nous montrons ici qu’elle est d’abord le résultat de la Crise longue ouverte dans les années 1970, dans laquelle le capitalisme survit en s’adonnant à ses penchants pour la rente, l’économie prédatrice, et la « solution spatiale » de la Mondialisation. Les métropoles sont les points d’ancrage spatial de cette « nouvelle économie ». La métropolisation, dans laquelle, comme toutes les études géographiques le montrent, les déséquilibres et les inégalités s’accroissent, est le faux-semblant urbain d’une réalité d’inversion spatiale et de désurbanisation, soumise aux flux centrifuges créés par la Crise.

  8. Management coaching - et drømmeværktøj?

    DEFF Research Database (Denmark)

    Nielsen, Anne Ellerup; NØrreklit, Hanne

    2004-01-01

    I følge (Giddens 1991) lever vi ikke længere i et modernitetssamfund, men befinder os i et samfund på et stadie af såkaldt høj-modernitet. Parallelt med denne udvikling har vi set en sand eksplosion af nye management teorier og værktøjer. Det giver anledning til at rejse følgende spørgsmål: hvilke ideologier ? ideer og tanker om hvordan social orden (gen)skabes ? er, der indlejret i disse management teorier og værktøjer? Mere præcist er formålet med denne artikel at undersøge hvorvidt de ideologiske antagelser om at (gen)skabe den sociale orden, som er indlejret i management coaching, som repræsenteret i "Lederens grønspætte håndbog", producerer en diskurs som tilhører høj-modernitetens Konklusionen er at "Lederens grønspætte håndbog" afspejler en diskrepans mellem forskellige "verdeners" diskurser. Ved at bruge sportscoaching som en ideal model for ledelse skabes en illusion, hvor urealistiske egenskaber fra sportsverdenen bliver projekteret over i lederen.

  9. CMS Is Finally Completed

    CERN Multimedia

    2008-01-01

    Yet another step in the completion of the Large Hadron Collider was taken yesterday morning, as the final element of the Compact Muon Solenoid was lowered nearly 100 meters bellow ground. After more than eight years of work at the world's most powerful particle accelerator, scientists hope that they will be able to start initial experiments with the LHC until the end of this year.

  10. Qualité et action publique

    Directory of Open Access Journals (Sweden)

    Marc Mormont

    2011-09-01

    Full Text Available L'article examine les conséquences pour l'action publique de la généralisation des procédures de qualité. Dans une première partie, la qualité est analysée historiquement comme un processus par lequel l'incertitude est réduite, essentiellement à l'intérieur du monde industriel, par des négociations entre entrepreneurs. La croissance de l'Etat social fait ensuite apparaître toutes les normes de qualité standard qui se réfèrent à des biens publics mais dont la production est largement déléguée à des experts et des négociations sectorielles sur un mode néo-corporatiste. Ceci élargit et confirme le modèle de la délégation de la qualité qui est conforme au schéma durkheimien de la production des normes.Trois évolutions récentes sont analysées. La première est l’entrée de la qualité dans le débat public qui élargit l’espace de demandes sociales de qualité à de nouveaux acteurs, plus diversifiés. La seconde est le rôle accru de la demande dans la définition de la qualité qui induit le secteur privé à articuler la qualité au consommateur. Enfin la qualité se définit de plus en plus de manière procédurale. Ces trois évolutions accentuent la tension entre l’espace de formulation des exigences de qualité et l’espace de la définition technique de la qualité. Ces trois évolutions valent mutatis mutandis pour le secteur public et posent de manière critique le rôle de l’Etat. Pour dépasser cette tension entre espace de la formulation des exigences de qualité et espace de normalisation technique, l’action publique doit être capable de prendre simultanément en charge débat et expertise dans un processus qui relève plus de l'innovation que de seule normalisation. Unmodèle expérimentaliste de l'action publique est proposé pour répondre à ce défi.

  11. Technologie et spécialisation internationale touristique

    OpenAIRE

    Sihabutr, Chaturaporn

    2012-01-01

    Cette recherche a pour objet d'examiner l'importance des facteurs technologiques dans la spécialisation internationale touristique. Le test consiste, à partir des données liées au tourisme et à la technologie, à synthétiser la corrélation existante entre tourisme et facteurs technologiques dans les dépenses du tourisme domestique et international, l'investissement touristique et les dépenses en recherche et développement (R&D), à partir d'une analyse comparative de données de 200...

  12. Avalanches : phénomènes et enjeux.

    OpenAIRE

    Ancey, Christophe

    2009-01-01

    Si les avalanches ne constituent pas un danger naturel majeur à l'échelle de la planète, elles représentent une menace et une contrainte fortes pour un pays montagneux comme la Suisse. Ce n'est donc pas un hasard si la Suisse a été la pionnière dans l'étude scientifique des avalanches avec les travaux d'un ingénieur forestier des Grisons, Johann Coaz, à la fin du XIXe siècle. Et c'est également sur le modèle suisse de zonage des risques - établi après le terrible hiver 1951 (98 morts) - que t...

  13. Conflits et conflictualités

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available Conflits de proximitéLe premier panel du séminaire s’est articulé autour du conflit de proximité. Ouvert par une introduction consacrée aux liens entre voisinage et violence, il a apporté deux illustrations à travers deux études de cas : à l’échelle d’une institution culturelle franco-allemande d’abord, puis au sein d’une communauté sociale particulière.La communication de Ulrich Bielefeld, intitulée « Proximité et violence », envisage le voisinage comme champ d’émergence du conflit, au sens ...

  14. Codes et turbocodes

    CERN Document Server

    Berrou, Claude

    2007-01-01

    Cet ouvrage est consacré à l'une des fonctions essentielles des systèmes de télécommunications modernes : le codage de canal ou codage correcteur d'erreurs. À la croisée de la théorie de l'information, des mathématiques et de l'électronique, le codage de canal a connu de nombreux développements depuis les travaux fondateurs de Claude Shannon. Du simple code de Hamming (1950) aux récents turbocodes (1993) en passant par les codes LDPC (1962), le codage de canal a considérablement évolué et a intégré des concepts de plus en plus sophistiqués, en particulier le traitement probabiliste de l'inform

  15. Porvoo - et højkirkeligt projekt

    DEFF Research Database (Denmark)

    Balslev-Clausen, Peter

    2010-01-01

    9. december 2009 underskrev Det mellemkirkelige Råd på Den danske Folkekirkes vegne den anglikansk-lutherske Porvoo-erklæring. Artiklen påviser, at Porvoo-samarbejdet bygger på et kirke- og embedssyn, de er fremmed for Den danske  Folkekirkes demokratisk-lutherske tradition. Som et illustrerende eksempel på forskellem mellem evangelisk-luthersk og anglikansk kristendomsforståelse anføres anglikaneren S. Baring-Gould's oversættelse af lutheraneren B.S. Ingemanns salme "Igennem nat og trængsel". Artiklen konkluderer, at Porvoo-tilslutningen over tid vil kunne få gennemgribende teologisk og forfatningsmæssig betydning for Den danske Folkekirke. Udgivelsesdato: September 2010

  16. (Désaffiliation et identité

    Directory of Open Access Journals (Sweden)

    Marielle Pepin-Lehalleur

    2011-06-01

    Full Text Available Au cours des trente dernières années, une série de ruptures significatives survenues au Mexique a redessiné les contextes où se forgent les significations publiques de l’identité ethnique et contribué à lui conférer de nouveaux sens politiques. L’indigénisme qui avait inspiré la doctrine officielle d’intégration des Indiens à la nation depuis la Révolution de 1910 s’est vu sérieusement critiqué par un certain nombre d’anthropologues et de mouvements indiens pionniers à partir des années 1970....

  17. Globalisation et espaces locaux

    Directory of Open Access Journals (Sweden)

    Évelyne Mesclier

    2011-04-01

    Full Text Available Cet ouvrage, épais volume de plus de 600?pages, explore les liens entre la globalisation et les espaces locaux. La plupart des vingt et quelque contributions portent sur le Mexique, le plus souvent sur l’État de Guanajuato, mais quelques-unes présentent des études de cas réalisées au Brésil, en Argentine ou à Porto Rico, voire en Inde ou au Mali. Dans l’ensemble, disons-le d’emblée, ce choix emporte l’adhésion?: la confrontation d’observations centrées sur un terrain particulier à des éclaira...

  18. Patpong, entre sexe et commerce.

    Directory of Open Access Journals (Sweden)

    Sébastien Roux

    2010-03-01

    Full Text Available Le tourisme dit « sexuel » est aujourd’hui décrié comme une forme de tourisme international immoral, un dysfonctionnement grave de la mondialisation appelant une réaction politique contre « l’exploitation sexuelle » dont seraient victimes des millions de femmes et d’enfants. Pourtant, derrière l’apparente évidence du « tourisme sexuel » comme expression de sens commun, rares sont les enquêtes qui explicitent la réalité concrète des échanges prostitutionnels. En adoptant une démarche ethnographique, l’article décrit le fonctionnement de Patpong, un quartier rouge de Bangkok dédié à une clientèle internationale. Par la description des offres disponibles, des revenus générés, des codes et des pratiques, la complexité de l’espace réapparaît. Il s’agit de donner à voir la réalité des échanges pour interroger l’articulation entre commerce et sexualité. L’analyse ethnographique du tourisme sexuel permet ainsi de souligner la diversité des pratiques et de rappeler que les formes les plus visibles — et les plus commentées — d’échanges prostitutionnels éclipsent trop souvent une pluralité d’expériences qui participe pourtant au succès de ces ruelles mondialement connues. So-called sex tourism is condemned as an immoral form of international tourism, a serious failure of globalization requiring political action against the “sexual exploitation” suffered by millions of women and children. Yet behind the common and seemingly evident understanding of “sexual tourism,” few studies have focused on the actual reality of such relations. Based on an ethnographic study, this article presents the structure of Patpong, a red-light district of Bangkok dedicated to international tourism. First, the article aims to briefly present the historical development of Patpong. This peculiar space is intrinsically linked to sex tourism, as these world-renowned streets expanded since the mid-60s to become one of the most famous red-light districts in Southeast Asia. Initially linked to the gi s’ military presence in Thailand during the Vietnam War, “recreational bars” have grown during the boom of international tourism. Limited to some specific areas, these bars became world-famous and started to be harshly discussed. Then the article describes how Patpong is organized. In actuality this area is not only dedicated to commercial sex but also to business. By underlining the presence of a Night Bazaar, and also drug shops, restaurants, discos, even jewelries, the depiction of Patpong reminds us of the complexity of exchanges that defines this red-light district. If commercial sex seems omnipresent, it has to be understood as a specific form of business developed in order to rationally maximize the benefits of the international visitors’ presence. Finally, the diversity of sexual offers is detailed. By describing the many available services, the incomes generated, the codes of conduct, and practices, the complexity of Patpong surfaces. The article not only depicts the diversity of sexual establishments and their rules (i.e., go-go bars, beer bars, sex shows, etc., but also points out the influence of non-sexual establishments, such as “regular” bars and the like. In fact, some prostitution activities take the form of ordinary relations and make us rethink the fine balance between sexuality and business. The ethnographical analysis of sex tourism thus highlights the multiplicity of practices and reminds us that the most visible — and most notorious — forms of prostitution often dismiss the multiple and complex factors that nonetheless contribute to the success of international sex.

  19. Littérature et bande dessinée. Enjeux et limites

    Directory of Open Access Journals (Sweden)

    Jan Baetens

    2009-05-01

    Full Text Available Le présent article se propose d’examiner deux aspects majeurs de la rencontre entre littérature et bande dessinée, dont le champ ne peut être limité à celui des seules adaptations de textes littéraires en bande dessinée. D’une part, il propose une définition de la bande dessinée littéraire (ou du roman graphique, peu importe la terminologie qui met l’accent sur le concept de récit, plus particulièrement sur le concept de récit visuel, pour analyser ensuite quels types de récits visuels sont considérés comme littéraires en bande dessinée. D’autre part, il démontre que l’analyse littéraire de la bande dessinée peut aider considérablement à renouveler l’étude de certains aspects de la théorie narrative, notamment dans le domaine du discours autobiographique et des techniques du feuilleton.This article deals with two crucial aspects of the encounter between literature and comics, which cannot be reduced to the mere problem of the adaptation of literary texts in comics. On the one hand, it offers a new definition of the literary comics (or graphic novel, although this kind of terminological discussions will be avoided here, which puts a strong emphasis on the concept of storytelling, more precisely of visual storytelling, and it analyzes which types of storytelling may be considered literary in the comics field. On the other hand, it argues that the literary reading of comics may prove dramatically helpful in the elaboration of new ways of interpreting narrative theory, for instance in the domain of autobiography as well as in the domain of the instalment techniques.

  20. Économie urbaine et régionale au tournant du siècle

    Directory of Open Access Journals (Sweden)

    Georges Benko

    2007-05-01

    Full Text Available Cet article met en relation la géographie économique des années 1990 et les théories économiques les plus récentes. Cette partie de l’article construit une typologie de la recherche contemporaine en économie spatiale en évoquant les éléments essentiels des travaux autour des notions de : organisation industrielle, district, réseau, gouvernance, conventions, et finalement mettant en opposition le local et le global comme approches de recherche. La conclusion propose quelques pistes de recherche.This article examines the relations between the economic geography of the 1990s and recent economic theories. The part of the article develops a typology of contemporary research in spatial economics outlining the key features of the following concepts : industrial organization, industrial district, network, governance and conventions. Finally it compares approaches which proceed respectively from an analysis of the local and the global. The conclusion proposes a number of directions for research.

  1. Présence et réglementation des mycotoxines dans les aliments au Maroc: Situation actuelle et perspectives

    Directory of Open Access Journals (Sweden)

    Abdellah Zinedine

    2007-12-01

    Full Text Available Les maladies d’origine alimentaire constituent à l’heure actuelle l’un des problèmes de santé publique les plus répandus à l’échelle internationale. Ces maladies sont causées par divers agents en particulier les microorganismes pathogènes. En plus des virus et des bactéries pathogènes, les champignons toxinogènes constituent un danger réel pour la santé de l’homme et de l’animal par la sécrétion de substances hautement toxiques au cours de leur prolifération dans les aliments d’origine végétale ou animale. Ces substances qu’on regroupe sous le nom des mycotoxines sont répandues dans tous les stades de la chaîne alimentaire. Dans ce travail, nous présentons un aperçu général sur les principales mycotoxines (les afatoxines, l’ochratoxine A, la zéaralénone et la fumonisine B1, leur structure chimique, leur toxicité et les aliments contaminés. Une comparaison entre la réglementation des mycotoxines par les autorités marocaines et européennes a fait aussi l’objet d’une revue dans ce travail. Finalement, nous présentons les résultats des principales investigations effectuées sur la présence de ces toxines dans certaines denrées alimentaires commercialisées au Maroc à travers l’expérience du laboratoire de Toxicologie de l’Institut National d’Hygiène de Rabat.

  2. Study on the Free-positioning of ETS in the PDL Track Surveying System

    OpenAIRE

    Hongtao Zhu; Weijun Wu; Zhiyong Wang

    2009-01-01

    The station positioning by the electric total station (ETS) is the first step which must be done for the passenger dedicated line track survey and one of the important factors which influence the final surveying precision. To enhance the surveying efficiency and surveying precision, we study the principles and methods of free positioning by ETS.

  3. ‘Valeurs, normes et évaluations’.

    Directory of Open Access Journals (Sweden)

    Yves Michaud

    2005-11-01

    Full Text Available Les normes se sont multipliées dans la réalité des pratiques et dans les modes de représentation des activités. Ce qui est relativement nouveau par rapport à une époque pas si lointaine où l’activité humaine était pensée en référence à des valeurs à la fois objectives et voulues par les sujets. Quelle est la signification du caractère conventionnel, utilitaire et collectif des normes ? Quelles sont les conséquences au plan de l’évaluation ? La pratique de l’évaluation systématique témoigne d’un mode de fonctionnement social qui fait intervenir flexibilité et réflexivité. On passe ainsi de l’ontologie des activités à leur être purement procédural. Norms invade our life in terms of normalized activities but also in terms of representation. This is something new compared to a not so distant time when human activities were described in reference to values which were both objective and the result of human will. What is the meaning of the conventional, utilitarian and collective nature of norms ? What are the consequences of this nature for evaluation ? The systematic benchmarking of activities and processes is connected to the presence of flexibility and reflexivity at the heart of the social system. We must realize that we moved from an ontology of action to a procedural view of it.

  4. Raymond Williams - et overblik

    OpenAIRE

    Michael Skovmand

    1990-01-01

    Raymond Williams er en af efterkrigstidens første kulturkritikere til at sætte den moderne massekommunikation og udvikling indenfor kom- munikationsteknologien ind i en større historisk og kulturel forståelses- ramme uden af forfalde til kulturpessimisme. I denne artikel giver Michael Skovmand et overblik over udviklingen i Williams kulturkritiske forfatterskab med en fyldig oversigt over de bøger, som er udgivet om ham efter hans død.

  5. ETS on "Golden Rule."

    Science.gov (United States)

    Anrig, Gregory R.

    1987-01-01

    The Golden Rule settlement's application in Illinois has not improved passing rates for Blacks on licensing tests relative to Whites. The Educational Testing Service (ETS) will apply the Golden Rule procedure in Illinois as long as the settlement remains in effect, but opposes it as precedent for other legislation. (SLD)

  6. Pistes forestières et imaginaire

    Directory of Open Access Journals (Sweden)

    Marie-Serge Lebon

    1990-05-01

    Full Text Available L'utilisation de chorèmes comme d'un alphabet susceptible de traduire des concepts, permet de proposer une représentation de l'imaginaire, celle de la forêt mythique de Bretagne, et de la confronter à celle de la réalité, la forêt bretonne actuelle.

  7. Diversité alimentaire et urbanisation

    Directory of Open Access Journals (Sweden)

    Ludivine Eloy

    2008-05-01

    Full Text Available São Gabriel da Cachoeira, ville du nord-ouest de l’Amazonie brésilienne, est majoritairement habitée par des familles amérindiennes. Nous nous demandons dans quelle mesure les territorialités amérindiennes permettent le maintien d’une certaine diversité alimentaire. Nous couplons pour cela l’étude des systèmes de production, l’observation participative des pratiques alimentaires et l’analyse des principales filières d’approvisionnement. L’incorporation de produits alimentaires d’origine exogène dans les repas des amérindiens est due principalement aux conditions d’accès aux ressources naturelles et de mobilisation de la main d’œuvre. Pour contourner ces contraintes, les groupes domestiques articulent les ressources urbaines et forestières grâce à des mobilités circulaires. De plus, à l’échelle de la famille élargie, les réseaux d’échange entre ville et forêt favorisent le maintien de la qualité des produits et l’agrobiodiversité.Food Diversity And Urbanization, Agrarian Transformations And Food Recomposition In The North-Western Amazon (Brazil São Gabriel da Cachoeira, a town located in the northwest of the Brazilian Amazon, is mainly inhabited by indigenous families. Our question is whether indigenous territorial practices lead to conservation of food diversity. Data were obtained by agro-economic interviews, participative observation of food practices and analysis of the main food chain supply in the town. Consumption of agroindustrial food by indigenous families is mainly due to urban conditions of access to natural resource and labor force employment. To cope with these constraints, domestic groups use multi-sited production units and circular mobility across urban and forest areas. Moreover, at a larger scale, the exchange networks between city and forest help to maintain the quality of products and agrobiodiversity conservation.

  8. The Phenix final tests

    International Nuclear Information System (INIS)

    After the final shutdown of the Phenix sodium cooled fast reactor and before decommissioning, a final set of tests were performed covering core physics (5 tests: measurement of individual subassembly reactivity worth, decay heat measurement, control rod offsetting, the reactivity effect of a gas bubble, and control rod worth measurement)), fuel behavior (1 test: MOX fuel pin melting) and thermal-hydraulics areas (2 tests: asymmetrical regime and natural convection). Detailed analysis of the tests results is ongoing. It will allow the extension of code validation for core physics, for thermal-hydraulics and for fuel behavior. In addition, the program included two tests related to the comprehension of the four negative reactivity transients (AURN in French acronym) experienced during the reactor operation in 1989 and 1990. The analysis of the AURN transients performed in the early nineties had concluded that the most likely mechanism for a fast decrease of the core reactivity was a radial core deformation named core flowering. The core flowering test was carried out by introducing a mechanical device to deform Phenix core. The purpose of the test was to measure the reactivity effect of such deformation at subcritical and critical zero power conditions. The mechanical behaviour of the core was close to what was expected. Very small changes on core radius give significant reactivity modifications. The standard instrumentation of the reactor was completed by specifically dhe reactor was completed by specifically designed devises. The PHENIX final tests program was performed successfully within the planned time schedule and provided a significant amount of data for the development of sodium fast reactors

  9. DANAERO MW: Final Report

    DEFF Research Database (Denmark)

    Troldborg, Niels; Bak, Christian

    2013-01-01

    This report describes the results of the EUDP funded DANAERO MW II project carried out by DTU Wind Energy (formerly Risø DTU) and the industrial partners, LM Wind Power, Vestas Wind Systems A/S and Siemens Wind Power. An overview of the data available from the project as well as the results from analysis of the data is given with the main objective to explore in detail the influence of atmospheric and wake turbulence on MW turbine performance, loading and stability. Finally, validation and demonstration of simulation codes are carried out.

  10. HERBE final safety report

    International Nuclear Information System (INIS)

    The Final safety report of HERBE system constructed at the RB reactor consists of 13 chapters, as follows. Chapter 0 includes a summary and the contents of the Final safety report, fundamental characteristics of the system and conclusion remarks, with the license agreement of the Safety Committee of the Boris Kidric Institute. Chapter 1 describes and analyzes the site of the HERBE system, including demography, topography, meteorology, hydrology, geology, seismicity, ecology. Chapter 3 covers technical characteristics of the system, Chapter 4 deals with safety analysis, Chapter 5 describes organisation of construction and preliminary operational testing of the system. Chapter 6 deals with organisation and program of test and regular operation, relevant procedures. Chapter 7 defines operational conditions and constraints, Chapter 8 and describe methods and means of radiation protection and radioactive materials management respectively. Chapter 10 contains a review of emergency plans, measures and procedures for nuclear accident protection. Chapters 11 and 12 are concerned with quality assurance program and physical protection of the HERBE system and related nuclear material

  11. The final cool down

    CERN Multimedia

    Thursday 29th May, the cool-down of the final sector (sector 4-5) of LHC has begun, one week after the start of the cool-down of sector 1-2. It will take five weeks for the sectors to be cooled from room temperature to 5 K and a further two weeks to complete the cool down to 1.9 K and the commissioning of cryogenic instrumentation, as well as to fine tune the cryogenic plants and the cooling loops of cryostats.Nearly a year and half has passed since sector 7-8 was cooled for the first time in January 2007. For Laurent Tavian, AT/CRG Group Leader, reaching the final phase of the cool down is an important milestone, confirming the basic design of the cryogenic system and the ability to operate complete sectors. “All the sectors have to operate at the same time otherwise we cannot inject the beam into the machine. The stability and reliability of the cryogenic system and its utilities are now very important. That will be the new challenge for the coming months,” he explains. The status of the cool down of ...

  12. Schedulability Analysis for Java Finalizers

    DEFF Research Database (Denmark)

    BØgholm, Thomas; Hansen, Rene Rydhof

    2010-01-01

    Java finalizers perform clean-up and finalisation of objects at garbage collection time. In real-time Java profiles the use of finalizers is either discouraged (RTSJ, Ravenscar Java) or even disallowed (JSR-302), mainly because of the unpredictability of finalizers and in particular their impact on the schedulability analysis. In this paper we show that a controlled scoped memory model results in a structured and predictable execution of finalizers, more reminiscent of C++ destructors than Java finalizers. Furthermore, we incorporate finalizers into a (conservative) schedulability analysis for Predictable Java programs. Finally, we extend the SARTS tool for automated schedulability analysis of Java bytecode programs to handle finalizers in a fully automated way.

  13. Martinez Antonio Francisco Javier et González González Irene (eds., 2011, Regenerar España y Marruecos. Ciencia y educación en las relaciones hispano-marroquíes a finales del siglo XIX, Madrid, Consejo Superior de Investigaciones Científicas-Colección de Estudios árabes e islámicos-Monografías, 496 p.

    Directory of Open Access Journals (Sweden)

    Ana Isabel Planet Contreras

    2012-04-01

    Full Text Available Durant la dernière décennie, l'historiographie espagnole s’est de plus en plus consacrée à l'étude du Protectorat espagnol dans le nord du Maroc. L'importance de ces travaux croît à mesure que de nouvelles sources d'archives deviennent accessibles. Grâce à ces sources, des monographies thématiques ou à caractère géographique ont été entreprises, et de nouvelles approches ont été adoptées pour l'étude de cette période. Contrairement à ce que l'on pourrait penser, il reste encore du travail à f...

  14. Éducation et Libération

    CERN Multimedia

    Jean-Pierre Lagnaux

    Vente des 30 novembre, 1er et 2 décembre Bâtiment principal Depuis notre information de mai dernier, la situation alimentaire en Afrique n'a fait que s'aggraver au rythme de la crise mondiale. Avec le soutien des Collectes à long terme de l'Association du personnel du CERN, nous avons pu : Poursuivre la mise en valeur du champ de maïs, manioc et ananas bio qui en est à sa deuxième saison de production. Il est question maintenant de construire une école primaire (une de plus dans le programme de notre partenaire au Bénin) mais il nous faudra collecter des fonds sur plusieurs années. Dans le quartier de cette école, à la rentrée de septembre, les parents ont à nouveaux manifesté. Mois après mois, nous maintenons en vie notre école primaire Kpeme au Togo. Les résultats des écoliers en fin d’...

  15. Conflits armés et Environnement : Cadre, modalités, méthodes et rôle de l’Évaluation Environnementale

    Directory of Open Access Journals (Sweden)

    Michel-André Bouchard

    2010-11-01

    Full Text Available Les conflits armés sont source de catastrophes majeures pour l’environnement. Dans les années 60, la défoliation de la jungle vietnamienne par l’armée américaine a interpellé la conscience collective sur la protection de l’environnement en situation de conflit armé (Pearce, 2000. La guerre du Golfe de 1990-1991, avec l’utilisation des armes à l’uranium appauvri et l’incendie des puits de pétrole a fait de la protection de l’environnement lors des conflits armés une préoccupation internationale. Des dispositions juridiques et réglementaires du droit international interdisent et limitent les actions néfastes sur l’environnement en temps de guerre. Au nombre de ces dispositions, il y a la Convention ENMOD de 1976, le Protocole I de Genève de 1977 et les Directives de la Croix-Rouge pour la formation des forces armées (1996. La difficulté de mise en œuvre de ces instruments est l’une des causes principales de l’exacerbation et de la persistance des impacts environnementaux des conflits armés. Un bref aperçu des travaux effectués dans ce domaine montre que cette question est jusque-là abordée sous un angle purement théorique, empirique et descriptif (causes, manifestations et typologies des conflits. Et, contrairement aux autres domaines de connaissances (scientifiques, économistes, juristes, universitaires, les spécialistes de l’évaluation environnementale se sont à ce jour peu intéressés à cette question.L’analyse des impacts environnementaux permet de dresser une typologie axée sur les trois grandes phases de déroulement des conflits armés: pré-conflit, syn-conflit et post-conflit. S’y ajoutent les impacts « collatéraux » qui se poursuivent même pendant la phase post-conflit.L’article analyse l’applicabilité de la procédure d’Evaluation Environnementale (EE et d’Evaluation Environnementale Stratégique (EES en distinguant les différentes phases des conflits armés et en insistant sur les processus de prévention, d’anticipation et d’atténuation des impacts. De cette analyse, il ressort que l’Evaluation Environnementale a un grand rôle à jouer en situation de conflit armé, notamment en intervenant dans les actions de planification de la gouvernance, les opérations humanitaires, les actions de reconstruction post-conflit et surtout dans les actions en amont des conflits.Une telle approche nécessite un cadre d’analyse adapté impliquant des outils méthodologiques et opérationnels adéquats, et en se plaçant dans une perspective globale du développement durable.Armed conflict and war are major impediments to sustainable development in numerous countries. In addition to well known dramatic humanitarian effects, it leads to less well known serious and important environmental impacts. From degradation of natural resources, such as water, agricultural land, forest and biodiversity to collateral environmental damages such as oil spills, and finally to the collapse of environmental governance, environmental impacts of conflicts may seriously affect post conflict rehabilitation and reconstruction and may sustain conditions of personal civil unrest afterwards. Numerous examples of such damages are now well documented from conflict-affected area. This paper discusses the applicability and usefulness of well established environmental assessment processes in various phases of conflict with emphasis on prevention, anticipation and attenuation of possible impacts.The analysis shows that environmental assessment may play a great role in situation of conflict, both at the pre- and post-conflict stage, and in some degree during the syn-conflict phases.  In post-conflict phases, Environmental Assessment (EIA methods can be used to evaluate environmental damages and to some degrees help in their mitigation. A number of evaluation and measuring techniques, such as diachronic satellite imagery analysis, field surveys, and other methods can then be used to measure the impacts as part of a standard Environmental and Social Impact Stud

  16. E.T. sündis uuesti

    Index Scriptorium Estoniae

    2002-01-01

    Kogupere ulmefilm "E.T. - sõber kaugelt" ("E.T. The Extra-Terrestrial") : režissöör Steven Spielberg : Ameerika Ühendriigid 1982. Restaureeritud ja paari omal ajal välja jäetud stseeniga täiendatud uusversioon

  17. Læsetilegnelse i et moderne skriftsamfund

    DEFF Research Database (Denmark)

    Kjertmann, Kjeld

    2007-01-01

    En sammenlignende undersøgelse af de læsepædagogiske muligheder i et uland med få trykte tekster og et teknologisk udviklet videnssamfund med en overflod af skriftsprog i alle sammenhænge med en kritisk holdning til uudnyttede muligheder i ilandet.

  18. Ambulantage et métropolisation

    OpenAIRE

    Jérôme Monnet

    2007-01-01

    « L’ambulantage » renvoie bien sûr au commerce ambulant, mais ce néologisme a pour but de dépasser la vision trop restrictive qui se concentre exclusivement sur les vendeurs ambulants en les associant le plus souvent à l’économie dite informelle ou souterraine. Cependant, il ne s’agit pas ici de nier l’importance de cette économie, que les conditions de la globalisation postfordiste et du capitalisme flexible semblent favoriser. De fait, les articles réunis dans ce dossier ...

  19. Diversité alimentaire et urbanisation

    OpenAIRE

    Ludivine Eloy

    2008-01-01

    São Gabriel da Cachoeira, ville du nord-ouest de l’Amazonie brésilienne, est majoritairement habitée par des familles amérindiennes. Nous nous demandons dans quelle mesure les territorialités amérindiennes permettent le maintien d’une certaine diversité alimentaire. Nous couplons pour cela l’étude des systèmes de production, l’observation participative des pratiques alimentaires et l’analyse des principales filières d’approvisionnement. L’incorporation de produits alim...

  20. Raymond Williams - et overblik

    Directory of Open Access Journals (Sweden)

    Michael Skovmand

    1990-08-01

    Full Text Available Raymond Williams er en af efterkrigstidens første kulturkritikere til at sætte den moderne massekommunikation og udvikling indenfor kom- munikationsteknologien ind i en større historisk og kulturel forståelses- ramme uden af forfalde til kulturpessimisme. I denne artikel giver Michael Skovmand et overblik over udviklingen i Williams kulturkritiske forfatterskab med en fyldig oversigt over de bøger, som er udgivet om ham efter hans død.

  1. Multiplicateurs et analyse fonctionnelle

    OpenAIRE

    Neuwirth, Stefan

    1999-01-01

    Nous étudions plusieurs propriétés fonctionnelles d'inconditionnalité en les exprimant à l'aide de multiplicateurs. La première partie est consacrée à l'étude de phénomènes d'inconditionnalité isométrique et presqu'isométrique dans les espaces de Banach séparables. Parmi ceux-ci, la notion la plus générale est celle de ``propriété d'approximation inconditionnelle métrique''. Nous la caractérisons parmi les espaces de Banach de cotype fini par une propriété simple d'``inconditionnalité par blo...

  2. Et aktiviserende idrettsanlegg

    DEFF Research Database (Denmark)

    Kural, René

    2008-01-01

    Bislett Stadion er på mange måder et forbilledligt eksempel på den gode planlægning og en formgivning, der fremmer artikulationen mellem stadion og den omgivende by. Uden at forfatteren påstår, at Bislett Stadion henvender sig til breddeidrætten eller den forbipasserende motionist, så hævder han alligevel, at det med sin fine integration i Oslo og de mange indblik til arenaen fremmer samvær, kreativitet og, af og til, endda aktivitet. Stadionet udfordrer således vanetænkningen bag rum til idræt, kultur og fritid ved at dyrke bynærheden til, dels at udlevere de vekslende scenarier i arenaen ucensureret til de forbipasserende, dels ved at skabe et skulpturelt sportsbyggeri, der finder sin typologiske og lidt stædige enegang i de omkransende boligblokke og gadesystemer. Arkitektfirmaet C.F. Møller viser en sjælden vilje til at skabe æstetisk symbiose mellem by og arkitektur samt bevægelse. Således vil jeg i det følgende fremhæve to aspekter ved Bislett: 1. Potentialet ved den "trodsige" bynærhed, som byggeriet fremstår med, og 2. kort pege på, at idrætten synes på vej væk fra den snævre forståelse af begrebet som konkurrence og medaljestrid og på vej mod at blive del af et bredere kulturbegreb.

  3. Racisme - et psykologisk perspektiv

    DEFF Research Database (Denmark)

    Singla, Rashmi; Busch-Jensen, Peter

    2007-01-01

    Racisme forstås traditionelt som diskrimination og eksklusion af grupper eller individer ud fra forestillinger om, at mennesker tilhører forskellige racer, der kan rangordnes. I denne betydning indebærer racisme altså en ide om, at mennesket findes i forskellige racemæssige udgaver, karakteriseret ved forskellige egenskaber lige fra hudfarve og ansigtsform til evner, talenter, intelligens og moral. Arvelighedseksperter har dog aldrig kunne påvise sådanne forskelle som nogen objektiv biologisk forekomst. Den har kort sagt vist sig temmelig uvidenskabelig. Idag forstås begrebet racisme typisk anderledes end tidligere. Hvor det førhen fremstod som et biologisk begreb, tolkes det i stigende grad som et kulturelt begreb, der indkredser forskelsbehandling af mennesker ud fra kulturelle tilhørsforhold og præferencer. Det er en vigtig nuancering og apdatering af begrebet i forhold til den tid, vi lever i. Men også den kan faktisk vise sig utilstrækkelig. Artiklen kaster først et historisk blik på fænomenet og præsenterer siden fire teoretiske vinkler på emnet. Fire vinkler der alle har bidraget og fortsat bidrager til nuancering og udvikling af vores forståelser af dette komplekse fænomen.

  4. Candide et le physicien

    CERN Document Server

    Espagnat, Bernard d'

    2008-01-01

    Les avancées considérables de la physique d'après guerre n'ont - on le sait - été possibles qu'au prix d'une vraie rupture entre elle et la physique dite " classique ". A quels changements cette rupture nous contraint-elle en ce qui concerne des notions essentielles, telles celles d'espace, de temps, d'objet et d'objectivité ? Quelles en sont les incidences quant à la portée de la connaissance, au rôle de la conscience, aux relations entre science et ontologie ? Ce sont là des questions de fond, fort délicates, auxquelles les personnes de tendance quelque peu philosophique sont plus sensibles que ne le sont les physiciens. Malheureusement, les premières ne disposent normalement pas des connaissances de pointe qui seules permettent d'approfondir de tels problèmes sans trop risquer de s'égarer. Etant donné l'impact que, par ses applications, la science a sur nos vies, nombreux sont ceux qui souhaitent se former une idée plus juste de ce qu'elle implique vraiment. Le présent ouvrage prend la for...

  5. Prévoir et gérer le risque

    OpenAIRE

    Denise Pumain

    2001-01-01

    A la faveur des alertes, planétaires ou locales, lancées au sujet de l'effet de serre et des variations climatiques, ou des pollutions des eaux et de l'air, la recherche scientifique s'est organisée, pour décrire et évaluer les risques, voire pronostiquer des échéances et des amplitudes de catastrophes probables. Une conséquence intéressante pour la géographie est l'intérêt croissant des spécialistes pour les analyses spatialisées des processus, notamment aux échelles interméd...

  6. Décentralisation et environnement en Chine

    OpenAIRE

    Xiong, Hang

    2012-01-01

    Dans la littérature, les débats autour du fédéralisme environnemental sont persistants et non-concluants. La Chine a poursuivi la tendance globale de la décentralisation et adopté un de facto fédéralisme environnemental. Dans ce pays vaste et diversifié, connaissances et compétences locales sont nécessaires pour développer des solutions appropriées pour de nombreux problèmes environnementaux souvent avec une nature locale ou régionale. Cependant, malgré le de facto fédéralisme environnemental...

  7. Immigration italienne et littérature luxembourgeoise

    Directory of Open Access Journals (Sweden)

    Joseph Boggiani

    2012-09-01

    Full Text Available Dans cet article, Joseph Boggiani propose de suivre l’écrivain luxembourgeois Jean Portante, dans sa recherche - à la fois thématique et formelle, de son identité de fils d’ouvriers italiens dans l’univers de la sidérurgie luxembourgeoise. Au fil des générations et de la mémoire, se pose et se résout le problème de la double appartenance et du conflit des cultures.

  8. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Stephen A.

    2003-06-23

    In this final technical report, a summary of work is provided. Concepts were developed for a new statistical cloud parameterization suitable for inclusion into global climate models. These concepts were evaluated by comparison to ARM data and data from cloud resolving models driven by ARM data. The purpose of this grant was to develop a new cloud parameterization for the global climate model of the Geophysical Fluid Dynamics Laboratory (GFDL) of the National Oceanic and Atmospheric Administration (NOAA). Note that uncertainties in cloud parameterizations are a key reason why prediction of climate change from climate models remain unacceptably uncertain. To develop the parameterizations, the observations and models provided by the Department of Energy's Atmospheric Radiation Measurement (ARM) program were analyzed and used.

  9. FINAL/ SCIENTIFIC TECHNICAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Henry; Singh, Suminderpal

    2006-08-28

    The overall objective of the Chattanooga fuel cell demonstrations project was to develop and demonstrate a prototype 5-kW grid-parallel, solid oxide fuel cell (SOFC) system that co-produces hydrogen, based on Ion America’s technology. The commercial viability of the 5kW SOFC system was tested by transporting, installing and commissioning the SOFC system at the Alternative Energy Laboratory at the University of Tennessee – Chattanooga. The system also demonstrated the efficiency and the reliability of the system running on natural gas. This project successfully contributed to the achievement of DOE technology validation milestones from the Technology Validation section of the Hydrogen, Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan. Results of the project can be found in the final technical report.

  10. AIPM Final Report

    Energy Technology Data Exchange (ETDEWEB)

    John Mookken

    2006-06-30

    The final AIPM project report consists of six sections. Each section includes information on the original AIPM project and extension work on the high temperature design. The first section (1) provides an overview of the program and highlights the significant targets to meet at the end of the program. The next section (2) summarizes the significant technical accomplishments by the SEMIKRON AIPM team during the course of the project. Greater technical details are provided in a collection of all the quarterly reports which can be found in the appendix. Section three (3) presents some the more significant technical data collected from technology demonstrators. Section four (4) analyzes the manufacturing cost or economic aspects of producing 100,000 units/yr. Section five (5) describes the commercialization efforts of the AIPM technology into the automotive market. The last section (6) recommends follow on work that will build on the efforts and achievements of the AIPM program.

  11. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Josef Michl

    2011-10-31

    In this project we have established guidelines for the design on organic chromophores suitable for producing high triplet yields via singlet fission. We have proven their utility by identifying a chromophore of a structural class that had never been examined for singlet fission before, 1,3-diphenylisobenzofuran, and demonstrating in two independent ways that a thin layer of this material produces a triplet yield of 200% within experimental error. We have also designed a second chromophore of a very different type, again of a structural class that had not been examined for singlet fission before, and found that in a thin layer it produces a 70% triplet yield. Finally, we have enhanced the theoretical understanding of the quantum mechanical nature of the singlet fission process.

  12. Investing EU ETS auction revenues into energy savings

    Energy Technology Data Exchange (ETDEWEB)

    Sijm, J.P.M.; Boonekamp, P.G.M. [ECN Policy Studies, Petten (Netherlands); Summerton, P.; Pollitt, H.; Billington, S. [Cambridge Econometrics CE, Cambridge (United Kingdom)

    2013-05-15

    The overall objective of this study is to analyse the effects of using EU ETS auction revenues to stimulate investments in energy savings in three key target sectors, i.e. Households, Tertiary and Industry (including both ETS and non-ETS industrial installations). The scenarios used refer basically to the situation before the recent agreement on the Energy Efficiency Directive (EED) and include (a mixture of) different policy options to enhance energy savings in the target sectors, in particular (1) reducing the ETS cap, (2) introducing an Energy Efficiency Obligation (EEO) for energy suppliers or distributors, and/or (3) using ETS auction revenues to support additional (private) investments in raising energy efficiency. In order to meet this objective a variety of different policy scenarios have been defined and analysed by means of the 'Energy-Environment-Economy Model for Europe (E3ME)'. The study presents and discusses a large variety of scenario modelling results by the year 2020 at the EU27 level. These results refer to, among others, energy savings, GHG emissions, the ETS carbon price, household electricity bills and to changes in some macro- or socio-economic outcomes such as GDP, inflation, employment or international trade. Finally, the study discusses some policy findings and implications, including options to enhance the effectiveness of some EE policies, in particular those having a potential adverse effect on the ETS carbon price.

  13. Licences libres et Open Access

    OpenAIRE

    Borboe?n, Nicolas

    2012-01-01

    How Open Access and Creative Commons licenses can apply to academic and research fields and what are the benefits. Comment le Libre Accès et les licences Creative Commons peuvent s’appliquer aux domaines académiques et de recherche et quels en sont les intérêts.

  14. Numériser et mettre en ligne

    CERN Document Server

    Claerr, Thierry

    2010-01-01

    Rendre les collections accessibles en ligne est devenu pour les institutions culturelles, d'enseignement et de recherche, un des défis majeurs du début du XXIe siècle. Les projets sont dès à présent nombreux, et concernent tous les types d'établissements et tous les supports. Mener à bien une opération de numérisation et de mise en ligne requiert un ensemble de repères et de connaissances pour l'organisation et la mise en oeuvre d'un projet de numérisation durable. Donner les clés du domaine en se fondant sur des savoirs pratiques et concrets est l'ambition de cet ouvrage, qui fournit un mode opératoire précis pour chacune des grandes étapes à prendre en compte - de la capture à la conservation numérique, en passant par l'interopérabilité, le référencement, et en intégrant l'environnement juridique et réglementaire. Coordonné par Thierry Claerr et Isabelle Westeel, spécialistes du sujet et responsables de formations sur la numérisation et la création de bibliothèques numériques,...

  15. Carnaval uruguayen et dictature

    Directory of Open Access Journals (Sweden)

    Dorothée Chouitem

    2010-02-01

    Full Text Available En période de répression, la société est amenée à réinventer ses codes de communication. L'Uruguay (1973 - 1985 a vu se transformer le carnaval en véritable « voix bruyante de la conscience collective » Davis (1979. En effet, ce lieu d'expression populaire par excellence n'est pas à considérer comme une simple « soupape de sûreté » qui détournerait l'attention de la réalité sociale mais plutôt comme un « moyen par lequel une communauté perpétue certaines de ses valeurs, par lequel aussi elle peut contester un ordre politique » Davis (1979. Ainsi, le carnaval s'est transcendé pour donner naissance à un espace tiers qui abritera en son sein l'un des vecteurs de la liberté de parole. Et, la murga va muter, devenir transgressive et subversive puis finira par être revendiquée comme l'un des éléments identificatoires d'une société en rupture. Nous nous proposons de présenter et commenter ce teatro de los tablados qui, sous étroite surveillance, va devenir le porte-parole d'une vérité autre en s'affranchissant de la censure. Nous analyserons comment la situation politique va amener certains paroliers à réinvestir et à travestir le genre pour parler au spectateur et lui donner la possibilité de manifester une forme d’engagement.During times of repression, society is made to develop new codes of communication. From 1973 to 1985, Uruguay has seen carnivals become true “representatives for collective conscience” Davies (1979. In fact, this highly regarded form of popular expression ought not to be considered as a simple “safety-valve” that would divert attention from the realities of society. It should be regarded instead as a “means through which a community perpetuates certain traditions, by which political orders may be challenged.” Davies (1979 Thus, the transcending of carnivals gives birth to a vector for freedom of speech. Moreover, the murga will evolve, becoming transgressive and subversive, before being claimed an identifying element in a collapsing society. We intend to introduce and comment on this teatro de los tablados which, under strict surveillance, will represent a new truth once censorship is abolished. We will analyse how the political situation will cause librettists to review and alter their style to convey a clear message to their audience and to give them the possibility to become involved.

  16. Signes et artefacts.

    Directory of Open Access Journals (Sweden)

    Samuel Périgois

    2006-04-01

    Full Text Available Les opérations de requalification des centres des petites villes se sont multipliées depuis deux décennies. Cet article analyse comment le réaménagement des centres-villes s’inscrit dans un processus de patrimonialisation qui participe à une nouvelle conception de l’urbanité à travers une mise en scène des espaces centraux. Cette mise en scène des espaces publics passe par la multiplication de signes d’ancienneté. On peut distinguer des modalités différentes selon que les artefacts mobilisés renvoient à l’histoire du lieu, à des éléments hérités du passé et réinscrits dans l’espace ou qu’ils relèvent d’une ancienneté générique telle qu’elle s’est popularisée dans l’usage des mobiliers urbains « de style » — comme les candélabres « tradition » et bornes en fonte symbolisant l’appartenance à une urbanité d’apparence. Ce phénomène identitaire particulier vise à produire une urbanité, au moins physique. Cette artefactualisation amène à une redéfinition de la patrimonialisation. La tendance actuelle à la substitution d’« objets patrimoines » par des signes rappelant leur existence passée et les artefacts simulant de l’ancienneté et suscitant de l’historicité mobilisent les notions d’ambiance, d’esthétique et de « simulacre » selon le terme utilisé par Jean Baudrillard. La combinaison des références au patrimoine local et à l’ancien générique participe d’une mise en scène plus globale visant à inscrire le centre dans le temps long et à la production esthétique d’une néo-archéo urbanité « petite ville ». Refitting operations of downtown areas of small cities have increased for two decades. This article analyzes how this restructuring falls under a process of “patrimonialisation” which takes part in a new design of “urbanity” through a setting in scene of central spaces. This setting in scene of public spaces finds expression in the multiplication of ancient signs. Some artefacts refer to the history of the place, with elements inherited from the past and registered in space; some others show a generic idea of the past as the widespread use of urban furniture tends to confirm — traditional lamppost and historical poles are the symbols of an urbanity of appearance. This phenomenon of identity construction aims at producing urbanity, at least physical. This “artefactualisation” brings to a redefinition of the “patrimonialisation”. The current trend to replace “inherited objects” by signs, which point out the pre-existence of these objects, and ancient past simulations refer to the concepts of atmosphere, aesthetics and “simulacra” according to the term used by Jean Baudrillard. The combination of “inherited objects” and ancient artefacts takes part in a setting in scene aiming at registering downtown areas in long time and creating aesthetic “neo-archeo” urbanity specific to small cities.

  17. Characterization of a gene family of outer membrane proteins (ropB) in Rhizobium leguminosarum bv. viciae VF39SM and the role of the sensor kinase ChvG in their regulation.

    Science.gov (United States)

    Foreman, Dallas L; Vanderlinde, Elizabeth M; Bay, Denise C; Yost, Christopher K

    2010-02-01

    The outer membrane of Gram-negative bacteria represents the interface between the bacterium and its external environment. It has a critical role as a protective barrier against harmful substances and is also important in host-bacteria interactions representing the initial physical point of contact between the host cell and bacterial cell. RopB is a previously identified outer membrane protein from Rhizobium leguminosarum bv. viciae that is present in free-living cells but absent in bacteroids (H. P. Roest, I. H. Mulders, C. A. Wijffelman, and B. J. Lugtenberg, Mol. Plant Microbe Interact. 8:576-583, 1995). The functions of RopB and the molecular mechanisms of ropB gene regulation have remained unknown. We identified and cloned ropB and two homologs (ropB2 and ropB3) from the R. leguminosarum VF39SM genome. Reporter gene fusions indicated that the expression of ropB was 8-fold higher when cells were grown in complex media than when they were grown in minimal media, while ropB3 expression was constitutively expressed at low levels in both complex and minimal media. Expression of ropB2 was negligible under all conditions tested. The use of minimal media supplemented with various sources of peptides resulted in a 5-fold increase in ropB expression. An increase in ropB expression in the presence of peptides was not observed in a chvG mutant background, indicating a role for the sensor kinase in regulating ropB expression. Each member of the ropB gene family was mutated using insertional mutagenesis, and the mutants were assayed for susceptibility to antimicrobial agents and symbiotic phenotypes. All mutants formed effective nodules on pea plants, and gene expression for each rop gene in bacteroids was negligible. The functions of ropB2 and ropB3 remain cryptic, while the ropB mutant had an increased sensitivity to detergents, hydrophobic antibiotics, and weak organic acids, suggesting a role for RopB in outer membrane stability. PMID:20023026

  18. Characterization of a Gene Family of Outer Membrane Proteins (ropB) in Rhizobium leguminosarum bv. viciae VF39SM and the Role of the Sensor Kinase ChvG in Their Regulation ?

    Science.gov (United States)

    Foreman, Dallas L.; Vanderlinde, Elizabeth M.; Bay, Denise C.; Yost, Christopher K.

    2010-01-01

    The outer membrane of Gram-negative bacteria represents the interface between the bacterium and its external environment. It has a critical role as a protective barrier against harmful substances and is also important in host-bacteria interactions representing the initial physical point of contact between the host cell and bacterial cell. RopB is a previously identified outer membrane protein from Rhizobium leguminosarum bv. viciae that is present in free-living cells but absent in bacteroids (H. P. Roest, I. H. Mulders, C. A. Wijffelman, and B. J. Lugtenberg, Mol. Plant Microbe Interact. 8:576-583, 1995). The functions of RopB and the molecular mechanisms of ropB gene regulation have remained unknown. We identified and cloned ropB and two homologs (ropB2 and ropB3) from the R. leguminosarum VF39SM genome. Reporter gene fusions indicated that the expression of ropB was 8-fold higher when cells were grown in complex media than when they were grown in minimal media, while ropB3 expression was constitutively expressed at low levels in both complex and minimal media. Expression of ropB2 was negligible under all conditions tested. The use of minimal media supplemented with various sources of peptides resulted in a 5-fold increase in ropB expression. An increase in ropB expression in the presence of peptides was not observed in a chvG mutant background, indicating a role for the sensor kinase in regulating ropB expression. Each member of the ropB gene family was mutated using insertional mutagenesis, and the mutants were assayed for susceptibility to antimicrobial agents and symbiotic phenotypes. All mutants formed effective nodules on pea plants, and gene expression for each rop gene in bacteroids was negligible. The functions of ropB2 and ropB3 remain cryptic, while the ropB mutant had an increased sensitivity to detergents, hydrophobic antibiotics, and weak organic acids, suggesting a role for RopB in outer membrane stability. PMID:20023026

  19. Offshore 2010. Final report

    International Nuclear Information System (INIS)

    An overview of the accomplishments of the various projects that have received support from the Norwegian Research Council's program 'Offshore 2010'. The following projects are presented, some have English and some Norwegian project names: 'Critical parameters influencing inhibitor performance in multiphase flow', 'Development of the drilling optimization simulator (DDS) and a totally integrated drilling optimization system', 'Produksjonsoptimalisering og automatisk styring av broenner og roerledninger (PETRONICS)', 'Termisk isolerte undervannsroer for sikring av broenntransport over store avstander', 'Utvikling av magnetisk frekvensformer for styring av store subsea pumper paa havdyp ned mot 4000 meter', 'Flerfase stroemningsmaaler for permanent nedihulls installasjon', 'Hastighetsmaaling i flerfase stroemning ved passiv akustikk', 'Oil/water seperation offshore: optimized flow- and seperation behavior', 'Stroemningshastighet', 'A rock mechanics based reservoir simulation', 'MultiTool fase 2 - et flerbruksverktoey for nedihulls applikasjoner', 'Utvikling av undervanns olje-i-vann monitor for kontinuerlig maaling av lave oljekonsentrasjoner basert paa TR-LIFS', 'Subsea multipath ultrasonic liquid flow meter', 'Fluid characterization at elevated pressures and temperatures (Flucha II)'. The two main goals for the research program are 1. The development of new technology and competency in the field of downhole- and subsea processing and multiphase transportation, and 2. Ing and multiphase transportation, and 2. Innovation and commercialisation in small and medium sized companies (less than 100 employees). Some details on the financing and results are included (ml)

  20. Too much love, a novel Kelch repeat-containing F-box protein, functions in the long-distance regulation of the legume-Rhizobium symbiosis.

    Science.gov (United States)

    Takahara, Masahiro; Magori, Shimpei; Soyano, Takashi; Okamoto, Satoru; Yoshida, Chie; Yano, Koji; Sato, Shusei; Tabata, Satoshi; Yamaguchi, Katsushi; Shigenobu, Shuji; Takeda, Naoya; Suzaki, Takuya; Kawaguchi, Masayoshi

    2013-04-01

    The interaction of legumes with N2-fixing bacteria collectively called rhizobia results in root nodule development. The number of nodules formed is tightly restricted through the systemic negative feedback control by the host called autoregulation of nodulation (AON). Here, we report the characterization and gene identification of TOO MUCH LOVE (TML), a root factor that acts during AON in a model legume Lotus japonicus. In our genetic analyses using another root-regulated hypernodulation mutant, plenty, the tml-1 plenty double mutant showed additive effects on the nodule number, whereas the tml-1 har1-7 double mutant did not, suggesting that TML and PLENTY act in different genetic pathways and that TML and HAR1 act in the same genetic pathway. The systemic suppression of nodule formation by CLE-RS1/RS2 overexpression was not observed in the tml mutant background, indicating that TML acts downstream of CLE-RS1/RS2. The tml-1 Snf2 double mutant developed an excessive number of spontaneous nodules, indicating that TML inhibits nodule organogenesis. Together with the determination of the deleted regions in tml-1/-2/-3, the fine mapping of tml-4 and the next-generation sequencing analysis, we identified a nonsense mutation in the Kelch repeat-containing F-box protein. As the gene knockdown of the candidate drastically increased the number of nodules, we concluded that it should be the causative gene. An expression analysis revealed that TML is a root-specific gene. In addition, the activity of ProTML-GUS was constitutively detected in the root tip and in the nodules/nodule primordia upon rhizobial infection. In conclusion, TML is a root factor acting at the final stage of AON. PMID:23390201

  1. Optimisation combinatoire Theorie et algorithmes

    CERN Document Server

    Korte, Bernhard; Fonlupt, Jean

    2010-01-01

    Ce livre est la traduction fran aise de la quatri me et derni re dition de Combinatorial Optimization: Theory and Algorithms crit par deux minents sp cialistes du domaine: Bernhard Korte et Jens Vygen de l'universit de Bonn en Allemagne. Il met l accent sur les aspects th oriques de l'optimisation combinatoire ainsi que sur les algorithmes efficaces et exacts de r solution de probl mes. Il se distingue en cela des approches heuristiques plus simples et souvent d crites par ailleurs. L ouvrage contient de nombreuses d monstrations, concises et l gantes, de r sultats difficiles. Destin aux tudia

  2. Final Technical Report

    International Nuclear Information System (INIS)

    The two main objectives of this project were: (1) to develop and test technologies to harvest, transport, store, and separate corn stover to supply a clean raw material to the bioproducts industry, and (2) engineer fermentation systems to meet performance targets for lactic acid and ethanol manufacturers. Significant progress was made in testing methods to harvest corn stover in a 'single pass' harvest mode (collect corn grain and stover at the same time). This is technically feasible on small scale, but additional equipment refinements will be needed to facilitate cost effective harvest on a larger scale. Transportation models were developed, which indicate that at a corn stover yield of 2.8 tons/acre and purchase price of $35/ton stover, it would be unprofitable to transport stover more than about 25 miles; thus suggesting the development of many regional collection centers. Therefore, collection centers should be located within about 30 miles of the farm, to keep transportation costs to an acceptable level. These collection centers could then potentially do some preprocessing (to fractionate or increase bulk density) and/or ship the biomass by rail or barge to the final customers. Wet storage of stover via ensilage was tested, but no clear economic advantages were evident. Wet storage eliminates fire risk, but increases the complexity of component separation and may result in a small loss of carbohydrate content (fermentation potential). A study of possible supplieon potential). A study of possible supplier-producer relationships, concluded that a 'quasi-vertical' integration model would be best suited for new bioproducts industries based on stover. In this model, the relationship would involve a multiyear supply contract (processor with purchase guarantees, producer group with supply guarantees). Price will likely be fixed or calculated based on some formula (possibly a cost plus). Initial quality requirements will be specified (but subject to refinement).Producers would invest in harvest/storage/transportation equipment and the processor would build and operate the plant. Pilot fermentation studies demonstrated dramatic improvements in yields and rates with optimization of batch fermentor parameters. Demonstrated yields and rates are approaching those necessary for profitable commercial operation for production of ethanol or lactic acid. The ability of the biocatalyst to adapt to biomass hydrolysate (both biomass sugars and toxins in the hydrolysate) was demonstrated and points towards ultimate successful commercialization of the technology. However, some of this work will need to be repeated and possibly extended to adapt the final selected biocatalyst for the specific commercial hydrolysate composition. The path from corn stover in the farm field to final products, involves a number of steps. Each of these steps has options, problems, and uncertainties; thus creating a very complex multidimensional obstacle to successful commercial development. Through the tasks of this project, the technical and commercial uncertainties of many of these steps have been addressed; thus providing for a clearer understanding of paths forward and commercial viability of a corn stover-based biorefinery

  3. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Aristos Aristidou Natureworks); Robert Kean (NatureWorks); Tom Schechinger (IronHorse Farms, Mat); Stuart Birrell (Iowa State); Jill Euken (Wallace Foundation & Iowa State)

    2007-10-01

    The two main objectives of this project were: 1) to develop and test technologies to harvest, transport, store, and separate corn stover to supply a clean raw material to the bioproducts industry, and 2) engineer fermentation systems to meet performance targets for lactic acid and ethanol manufacturers. Significant progress was made in testing methods to harvest corn stover in a “single pass” harvest mode (collect corn grain and stover at the same time). This is technically feasible on small scale, but additional equipment refinements will be needed to facilitate cost effective harvest on a larger scale. Transportation models were developed, which indicate that at a corn stover yield of 2.8 tons/acre and purchase price of $35/ton stover, it would be unprofitable to transport stover more than about 25 miles; thus suggesting the development of many regional collection centers. Therefore, collection centers should be located within about 30 miles of the farm, to keep transportation costs to an acceptable level. These collection centers could then potentially do some preprocessing (to fractionate or increase bulk density) and/or ship the biomass by rail or barge to the final customers. Wet storage of stover via ensilage was tested, but no clear economic advantages were evident. Wet storage eliminates fire risk, but increases the complexity of component separation and may result in a small loss of carbohydrate content (fermentation potential). A study of possible supplier-producer relationships, concluded that a “quasi-vertical” integration model would be best suited for new bioproducts industries based on stover. In this model, the relationship would involve a multiyear supply contract (processor with purchase guarantees, producer group with supply guarantees). Price will likely be fixed or calculated based on some formula (possibly a cost plus). Initial quality requirements will be specified (but subject to refinement).Producers would invest in harvest/storage/transportation equipment and the processor would build and operate the plant. Pilot fermentation studies demonstrated dramatic improvements in yields and rates with optimization of batch fermentor parameters. Demonstrated yields and rates are approaching those necessary for profitable commercial operation for production of ethanol or lactic acid. The ability of the biocatalyst to adapt to biomass hydrolysate (both biomass sugars and toxins in the hydrolysate) was demonstrated and points towards ultimate successful commercialization of the technology. However, some of this work will need to be repeated and possibly extended to adapt the final selected biocatalyst for the specific commercial hydrolysate composition. The path from corn stover in the farm field to final products, involves a number of steps. Each of these steps has options, problems, and uncertainties; thus creating a very complex multidimensional obstacle to successful commercial development. Through the tasks of this project, the technical and commercial uncertainties of many of these steps have been addressed; thus providing for a clearer understanding of paths forward and commercial viability of a corn stover-based biorefinery.

  4. Corps et âme. Passionnément

    Directory of Open Access Journals (Sweden)

    Lucienne Strivay

    2010-06-01

    Full Text Available Affecter les émotions au registre corporel posé comme universel et stable aurait dû tomber depuis longtemps, mais les préjugés sont têtus. Malgré la diversité culturelle, le corps est habituellement convoqué comme nature posée dans son universalité. Les disciplines et écoles se sont partagé un territoire, préservant de la sorte leur autonomie. Corporéité et signification semblent condamnées à la divergence, positionnées de part et d’autre de ce que les auteurs dénomment « la couture ». Les déplacements de cette couture sont examinés au fil des théories concurrentes, pour en venir à l’analyse du point sensible où les « infiltrations » se manifestent, qui font craquer la couture, moment analytique privilégié pour la socio-anthropologie de la connaissance. On en arrive à une redistribution entre ce qui est intérieur et ce qui est extérieur, ce qui engage une redéfinition du corps, du psychisme, et de la sensibilité incarnée. Le cas des « enfants sauvages » est examiné à travers la littérature ethnographique classique qui leur a été consacrée, pour saisir à la fin l’importance incontournable du langage pour penser l’accession à l’humanité.Body and soul. PassionatelyThe idea of emotions belonging to the bodily sphere as constituting a universal and stable fact should have fallen by the way a long time ago, but prejudices are stubborn. In spite of cultural diversity, the body is generally presented as nature in its universal essence. Different disciplines and schools of thought divided up the territory, each thus preserving its autonomy. Bodily matters and significations seemed thus condemned to divergence, each one positioned with regards to what the authors call “the seam” (la couture. Using competing theories, shifts from the seam are examined in order to arrive at the analysis of a critical point, there where “infiltrations” appear, that is infiltrations which will crack the seam and so provide a privileged analytical moment for the socio-anthropology of knowledge. We arrive then at a redistribution between what is interior and what is exterior, leading in turn to a redefinition of the body, the psyche and incarnated sensibility. The case of “wild children” is also examined. After consulting the classic ethnographic literature which deals with them, the analysis culminates with the inescapable importance of language for conceptualising the accession to humanity.Cuerpo y alma. ApasionadamenteConsiderar las emociones como una característica de lo corporal es un pensamiento que hubiera debido desaparecer desde hace mucho tiempo pero los prejuicios siguen persistiendo con obstinación. A pesar de la diversidad cultural, lo corporal es considerado como un elemento de la natura con carácter universal. Las escuelas de pensamiento y las diferentes disciplinas académicas se han distribuido de manera autónoma el campo del análisis de lo corporal. Como consecuencia, los diferentes significados de la corporeidad están condenados a tener destinos divergentes, separadas y al mismo tiempo unidas por lo que los autores llaman “costura”. La trayectoria de esta “costura” es analizada bajo los prismas de diferentes teorías con el fin de vislumbrar la posible existencia de un punto de contacto entre estos diferentes significados que ponga en evidencia la posibilidad de hacer desaparecer estos compartimientos estancos, momento analítico privilegiado por la socioantropología del conocimiento. Desembocamos así en una redistribución entre lo que pertenece a lo interior y lo que pertenece a lo exterior, lo cual implica redefinir lo que es el cuerpo, el psiquismo y la sensibilidad. El caso de los “niños salvajes” es examinado aquí a través los libros etnográficos que se les han consagrado, con el fin de subrayar que el lenguaje es el criterio de accesión a la categoría de lo humano.

  5. Événement, idéologie et utopie

    Directory of Open Access Journals (Sweden)

    Jean-Luc AMALRIC

    2014-12-01

    Full Text Available RESUMEL’hypothèse que tente d’esquisser cet article est que l’idée ricœurienne d’une médiatisation dynamique des contradictions de l’imaginaire social présuppose une corrélation originaire de l’idéologie et de l’utopie qui ne peut elle-même être comprise qu’à partir de l’événement de l’institution d’un imaginaire social constituant. Dans un premier temps, l’article s’efforce de cerner ce qui fait la spécificité de la théorie ricœurienne de l’idéologie et de l’utopie comme « pratiques imaginatives », en soulignant à ce titre l’influence déterminante des thèses de Jacques Ellul sur l’idéologie. Puis, dans un second temps, il s’engage dans une analyse régressive qui conduit de la réappropriation ricœurienne de la conception dialectique de l’idéologie et de l’utopie exposée par Mannheim à l’idée d’un fondement événementiel de ces deux formes opposées de l’imaginaire social.Mots-Clés : Evénement, idéologie, utopie, Ellul, Mannheim. ABSTRACTThis paper attempts to sketch out the hypothesis that the Ricœurian conception of a dynamic mediatization of the contradictions of the social imaginary presupposes an original correlation between ideology and utopia, which can itself be understood only from the event that institutes a constitutive social imaginary. The first part of the paper marks out the specificity of the Ricœurian theory of ideology and utopia in terms of “imaginative practices”, underlining the determining influence of Jacques Ellul’s theses on ideology. The second part tries to develop a regressive argument, starting from the Ricœurian re-appropriation of Mannheim’s dialectical conception of ideology and utopia, and leading back to the idea of an event foundation for these two opposed forms of the social imaginary.Keywords : Event, Ideology, Utopia, Ellul, Mannheim   

  6. Hawthorne et ses métalepses

    Directory of Open Access Journals (Sweden)

    Guillaume Tanguy

    2007-08-01

    Full Text Available « […] the portrait, frame and all, tumbled suddenly from its position,and lay face downward on the floor. »(Nathaniel Hawthorne, The House of the Seven Gables« La visibilité est un piège. »(Michel Foucault, Surveiller et punir« [Le] contact même imaginaire immunise contre la mort […]. »(Julien Gracq, La littérature à l’estomacÀ la lecture de la critique consacrée à Nathaniel Hawthorne, le lecteur ne manque pas d’être frappé par un certain nombre d’idées récurrentes. L’« interstice », le « ...

  7. Sources et bibliographie

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available Sources publiéesDuru (L.-M., Bibliothèque historique de l’Yonne, 2 vol., Auxerre-Paris, 1850-1864.Longnon (A., Pouillés de la province de Sens, Paris, 1904.Quantin (M., Cartulaire général de l’Yonne, 3 vol., Auxerre, 1850-1854.Sot (M., sous la dir., Les gestes des évêques d’Auxerre, t. I, Paris, 2002.BibliographieArnaud (C., « L’église romane de Lucy-sur-Yonne », BSFAY, 10, 1993, p. 33-48.Büttner (S. et Henrion (F., « Les sarcophages du haut Moyen Âge en Bourgogne du Nord. Approches mé...

  8. Kvindehandel : Et kommenteret litteraturstudium

    DEFF Research Database (Denmark)

    Baumbach, Trine

    2008-01-01

     Kvindehandel er i disse år et fokusområde både nationalt og internationalt - og både på det retlige, på det politimæssige og på det politiske niveau. Ved lov nr. 380/2002 blev kvindehandel (menneskehandel) særskilt kriminaliseret i straffeloven. Bestemmelsen er formuleret med udgangspunkt i FN's Palermo-protokol om forebyggelse, bekæmpelse og retsforfølgning af menneskehandel, særlig handel med kvinder og børn, og EU's rammeafgørelse om bekæmpelse af menneskehandel. Siden bestemmelsen trådte i kraft den 8. juni 2002, har der ifølge politiets opgørelser i perioden 2003 til 2007 været i alt 39 sigtelser og 21 fældende afgørelser for overtrædelse af bestemmelsen.  Selvom forarbejderne til § 262 a forsøger at give enkelte fortolkningsanvisninger, er det uden videre klart, at bestemmelsen - med dens tilblivelseshistorie - giver anledning til en række afgrænsningsspørgsmål, der endnu ikke er behandlet fra en dogmatisk synsvinkel. Det foreliggende kommenterede litteraturstudium er udarbejdet med det formål at fremfinde og kommentere materiale, der kan danne grundlag for en nærmere retlig analyse af det strafferetlige problemfelt kvindehandel. Den korrekte retlige term er "menneskehandel", men da projektet har fokus på handel med kvinder, særligt til prostitution, er ordet kvindehandel valgt, fordi det mere fokuseret associerer til den relevante problemstilling. Det inddragede materiale er udvalgt med det formål at belyse de retlige aspekter af problemfeltet strafbar kvindehandel. For imidlertid at få et mere helhedsorienterede billede af feltet strafbar kvindehandel og under henvisning til, at der alene findes meget lidt materiale af retlig karakter, er der endvidere inddraget materiale af mere sociologisk/antropologisk præget karakter. Endvidere er relevante domme (inkl. domme fra EF-domstolen og Den Europæiske Menneskerettighedsdomstol) inddraget. Da hovedparten af de kvinder på verdensplan, der bliver handlet, handles til prostitution, er det ikke muligt at skille de to fænomener. Som følge heraf er der i et vist mindre omfang inddraget materiale vedrørende prostitution. Sidstnævnte materiale er begrænset til få artikler, der har fokus på, hvordan vi i Danmark forholder os til prostitution som fænomen, og herunder til efterspørgselssiden, der jo er den faktiske og økonomiske årsag til, at fænomenet (kvindehandel til prostitution) overhovedet eksisterer. For at highlighte, at kvindehandel ikke er en offerløs forbrydelse eller blot et udlændingeretligt problem, men tværtimod udgør en grov krænkelse af de individuelle handlede kvinders liv og værdighed, har jeg endelig valgt at fremdrage enkelte skønlitterære værker af (i hvert fald nogen) dokumentarisk karakter.

  9. Internet et la géographie

    Directory of Open Access Journals (Sweden)

    Denise Pumain

    1998-07-01

    Full Text Available Voici venir la saison du surf. .Trop souvent hélas, la navigation sur Internet se réduit à un flottement indécis, voire s'achève par la noyade! De très nombreux sites répondent au même mot-clé (par exemple, un seul moteur de recherche vous propose plus de 4000 sites à l'appel du mot "geography". Beaucoup n'ont en fait aucun rapport avec le sujet qui vous intéresse (on ne saurait reprocher à certains groupes de rock d'avoir jugé bon d'inclure le mot géographie dans leur intitulé et le conten...

  10. Catulle et ses lecteurs

    Directory of Open Access Journals (Sweden)

    Evrard Delbey

    2004-01-01

    Full Text Available A la mémoire de J. Granarolo,ce Catullien vivant. Nous inscrivons cette étude dans un sujet plus vaste : la construction de plusieurs types de lecteurs par un auteur. Nous avons choisi la figure d'un poète latin du 1er siècle av. J.-C. pour analyser cette diversité qui agit sur les processus de réception d'un recueil de Poèmes et dont l'un des aspects consiste en la figure du poète lecteur de lui-même, devenu autre par l'énonciation de son nom propre. Nous organiserons ce travail de manière à...

  11. Medborgercentre - et fremtidigt bibliotekskoncept

    DEFF Research Database (Denmark)

    Delica, Kristian Nagel; Nilsson, Ida Norvin

    2012-01-01

    Denne evaluering undersøger det nationale SATS-puljestøttede udviklingsprogram ‘Etablering og videreudvikling af medborgercentre i udsatte boligområder’, hvor folkebiblioteker beliggende i såkaldt udsatte boligområder søges udviklet til medborgercentre. Ad denne vej udvikles og udvides folkebibliotekets traditionelle opgaveportefølje, og biblioteket bliver rygraden i en hybrid institution, der via en sammensætning af forskellige fagprofessionelle, frivillige og brugere etablerer en social innovativ platform med tråde til både den offentlige og den frivillige sektor. Evalueringen sætter fokus på otte af de i alt 16 projekter, som Kulturstyrelsens Center for Bibliotek, Medier og Digitalisering gennem perioden fra 2008-2011 har ydet udviklingsstøtte til. Evalueringen bygger datamæssigt på projekternes egne halvårlige statusrapporter, projekternes udvidede slutevalueringsrapporter, to fokusgruppeinterviews med projektledere fra de otte udvalgte projekter og endelig på debatter og diskussioner fra de seks temamøder, der har været afholdt i regi af det samlede, nationale udviklingsprojekt hen over projektperioden. Evalueringen falder i tre dele: Den første del introducerer evalueringskonceptet og synliggør både tidligere erfaringer med biblioteksudvikling af relevans for projektet og de anvendte teoretiske pejlemærker (‘behovsorienteret biblioteksarbejde’ og social innovation). Anden del består af separate empiri – og praksisnære caseevalueringer af de otte projekter. Endelig samler tredje del op på de otte caseevalueringer og fremhæver de markante pointer, der går på tværs heraf. Evalueringen fremhæver, at de biblioteksbaserede medborgercentre kan ses som socialt innovative organisatoriske platforme i de udsatte boligområder, og at disse spiller en central rolle i relation til følgende områder: For det første udgør de en glimrende ramme til en øget behovsorientering af det bibliotekariske arbejde, hvorved bruger/publikumsinvolveringen gøres til et centralt element i det daglige arbejde. For det andet er de centrale som arenaer for (formelle såvel som uformelle) læringsaktiviteter. For det tredje udgør de en efterspurgt institutionel ressource i områderne, idet de ofte indtager rollen som facilitator, igangsætter og vært for et væld af borgerrettede aktiviteter. For det fjerde danner de rammen om uvildige rådgivnings – og vejledningsservices, der parret med bibliotekets rolle som frirum etablerer et trygt rum for borgerne. Her kan de få hjælp til stort og småt, uden at det involverer myndighedsudøvende funktioner. Alt i alt rummer erfaringerne fra de evaluerede projekter ansatserne til et socialt sensitivt, behovs- og områdeorienteret bibliotekskoncept, der fortsat fastholder og udbygger bibliotekets rolle som kulturel oplysningsinstitution.

  12. Linguistique textuelle et diachronie

    OpenAIRE

    Combettes Bernard

    2012-01-01

    On s'interrogera, dans cet exposé, sur les conditions nécessaires, tant au plan théorique qu'au plan méthodologique, pour que la prise en compte de la dimension diachronique par la linguistique textuelle puisse constituer une discipline dotée de ses notions et de ses problématiques propres, de la même façon que la spécificité de l'approche diachronique sait être reconnue lorsqu'il s'agit de phonétique, de morphosyntaxe ou de sémantique. Si bon nombre d'études existent déjà dan...

  13. Final Report to DOE

    Energy Technology Data Exchange (ETDEWEB)

    Ismail Gultepe

    2012-05-15

    This final report summarizes the accomplished goals and provide a list of the publications and presentations made during the project. The goals of the project were accomplished through the various publications submitted to Journals and presentations done at the DOE and international meetings and conferences. The 8 journal articles related to the goals of this project were accepted or submitted. The 23 presentations related to goals of the project were presented at the meetings. There were some minor changes regarding to project goals because of issues encountered during the analysis of the data. For example, a total water probe sensor mounted on the Convair-580 that can be used for defining mixed phase conditions and parameterization, had some problems to estimate magnitude of total water mass, and this resulted in issues providing an accurate parameterization for cloud fraction. Variability related aerosol number concentrations and their composition for direct and indirect effects were studied and published. Results were given to explain aerosol and ice microphysical effects on climate change studies. It is suggested that developed parameterizations should consider the variability in aerosol and ice parameters over the Arctic regions.

  14. Tiger LDRD final report

    Energy Technology Data Exchange (ETDEWEB)

    Steich, D J; Brugger, S T; Kallman, J S; White, D A

    2000-02-01

    This final report describes our efforts on the Three-Dimensional Massively Parallel CEM Technologies LDRD project (97-ERD-009). Significant need exists for more advanced time domain computational electromagnetics modeling. Bookkeeping details and modifying inflexible software constitute a vast majority of the effort required to address such needs. The required effort escalates rapidly as problem complexity increases. For example, hybrid meshes requiring hybrid numerics on massively parallel platforms (MPPs). This project attempts to alleviate the above limitations by investigating flexible abstractions for these numerical algorithms on MPPs using object-oriented methods, providing a programming environment insulating physics from bookkeeping. The three major design iterations during the project, known as TIGER-I to TIGER-III, are discussed. Each version of TIGER is briefly discussed along with lessons learned during the development and implementation. An Application Programming Interface (API) of the object-oriented interface for Tiger-III is included in three appendices. The three appendices contain the Utilities, Entity-Attribute, and Mesh libraries developed during the project. The API libraries represent a snapshot of our latest attempt at insulated the physics from the bookkeeping.

  15. Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Alexander Pigarov

    2012-06-05

    This is the final report for the Research Grant DE-FG02-08ER54989 'Edge Plasma Simulations in NSTX and CTF: Synergy of Lithium Coating, Non-Diffusive Anomalous Transport and Drifts'. The UCSD group including: A.Yu. Pigarov (PI), S.I. Krasheninnikov and R.D. Smirnov, was working on modeling of the impact of lithium coatings on edge plasma parameters in NSTX with the multi-species multi-fluid code UEDGE. The work was conducted in the following main areas: (i) improvements of UEDGE model for plasma-lithium interactions, (ii) understanding the physics of low-recycling divertor regime in NSTX caused by lithium pumping, (iii) study of synergistic effects with lithium coatings and non-diffusive ballooning-like cross-field transport, (iv) simulation of experimental multi-diagnostic data on edge plasma with lithium pumping in NSTX via self-consistent modeling of D-Li-C plasma with UEDGE, and (v) working-gas balance analysis. The accomplishments in these areas are given in the corresponding subsections in Section 2. Publications and presentations made under the Grant are listed in Section 3.

  16. 12 MW : Final report

    DEFF Research Database (Denmark)

    Hasager, Charlotte Bay; Pena Diaz, Alfredo

    2009-01-01

    '12MW: final report' is for the project with the full title ‘12 MW wind turbines: the scientific basis for their operation at 70 to 270 m height offshore’ that had the goal to experimentally investigate the wind and turbulence characteristics between 70 and 270 m above sea level and thereby establish the scientific basis relevant for the next generation of huge 12 MW wind turbines operating offshore. The project started 1st October 2005 and ended 31st March 2009. Firstly was conducted a 6-month experiment at the Horns Rev offshore wind farm deploying a lidar and a sodar on the transformer platform. The observed data were successfully compared to offshore mast data and the wind profile was extended 100 m above previous levels observed in this offshore environment. The wind and turbulence was observed up to 160m above mean sea level. A new normalization was introduced to group the wind profiles into stability groups with variable roughness. Secondly two experiments were conducted at Høvsøre at the North Sea coast in Jutland. Again the wind profile was extended far beyond previous observed levels, up to 300 m above ground. The analysis showed that the profiles extended far beyond the surface layer and therefore surface layer scale alone could not described the profiles well. In addition the boundary layer height has to be used for the scaling. The boundary layer height was observed by an aerosol lidar at Høvsøre. The results are published widely, please see the list of publications.

  17. Acoustic Separation Technology; FINAL

    International Nuclear Information System (INIS)

    Today's restrictive environmental regulations encourage paper mills to close their water systems. Closed water systems increase the level of contaminants significantly. Accumulations of solid suspensions are detrimental to both the papermaking process and the final products. To remove these solids, technologies such as flotation using dissolved air (DAF), centrifuging, and screening have been developed. Dissolved Air Flotation systems are commonly used to clarify whitewater. These passive systems use high pressure to dissolve air into whitewater. When the pressure is released, air micro-bubbles form and attach themselves to fibers and particles, which then float to the surface where they are mechanically skimmed off. There is an economic incentive to explore alternatives to the DAF technology to drive down the cost of whitewater processing and minimize the use of chemicals. The installed capital cost for a DAF system is significant and a typical DAF system takes up considerable space. An alternative approach, which is the subject of this project, involves a dual method combining the advantages of chemical flocculation and in-line ultrasonic clarification to efficiently remove flocculated contaminants from a water stream

  18. Project 'Windbank' - Final Report

    International Nuclear Information System (INIS)

    An emergency decision support system for accidental releases of radioactivity into the atmosphere providing regional wind field information was developed. This system is based on intensive meteorological field campaigns each lasting 4 months in the regions around the Swiss nuclear power plants. The wind data from temporary and permanent stations were analysed to evaluate the typical wind field patterns occurring in these regions. A cluster analysis for these data-sets lead to 19 different wind field classes with a high separation quality. In separate studies, it was demonstrated that an on-line acquisition of meteorological data from existing permanent stations is enough to diagnose the recent wind field class in a region with a diameter of about 50 km around the nuclear power stations with a probability of about 80% to hit the correct class. Furthermore, a method was developed to use a high resolution weather prediction model to forecast the future wind field classes. An average probability of over 60% to hit the correct class for a forecast time of 48 hours was evaluated. Finally, a method for parameterization of turbulence providing input for dispersion models from standard meteorological on-line data was developed. (author)

  19. Les Dragaš et le mont Athos

    Directory of Open Access Journals (Sweden)

    Živojinovi? Mirjana

    2006-01-01

    Full Text Available (francuski L'auteur de ce travail considère les rapports des Dragaš avec certains monastères athonites: Saint-Pantéléèmôn, Chilandar, Iviron, Kutlumus et Vatopédi. En l'occurrence, on sait qu'outre la confirmation d'anciens privilèges fonciers, ils ont octroyé de nouveaux droits à ces établissements à travers la donation de nombre de villages et d'églises sis sur le territoire de leur Etat, très agrandi après la bataille de la Maritsa (26 septembre 1371, et, le cas échéant, ont résolu les litiges fonciers les opposant entre eux. Cette activité est attestée par plusieurs documents délivrés à ces monastères, dont les indications chronologiques subsistant sur les originaux endommagés ne sont pas toujours fiables, alors qu'elles font totalement défaut sur les copies. L'auteur estime que Chilandar et Saint Pantéléèmôn sont les premiers monastères athonites à avoir sollicité l'intervention des nouveaux maîtres de la région de la Strumica, tout d'abord pour résoudre un litige concernant le village de Breznica, qui opposait ces deux établissements depuis approximativement 1364. On sait que ce village est vraisemblablement échu au monastère russe un peu après juin 1374. A cette époque, d'après des copies conservées, les frères Dragaš — le despote Jovan et gospodin Konstantin — ont offert à Saint-Pantéléèmôn une dizaine de villages sis dans la région de la Strumica, dont la majorité existent encore aujourd'hui, ainsi qu'un ou deux hameaux; la donation de ces villages incluait celle de neuf églises patrimoniales, auxquelles ils ont également ajouté une église située à Strumica et deux respectivement à Pétrie et dans les environs de cette ville. Pour sa part, le gospodin Konstantin semble avoir rattaché à Saint-Pantéléèmôn jusqu'à 18 villages, 3 hameaux et 6 églises sis dans la région de Tikveš. En fait, nous possédons uniquement une seule copie faisant état de la donation à cet établissement de l'église Saint-Georges sise à Pološko avec les villages de Pološko, Košane et Dragoželj. Cependant cette donation pourrait justement être mise en doute compte tenu que nous savons que l'empereur Dušan a rattaché cette église avec les trois villages mentionnés au monastère de Chilandar en février 1340. L'auteur attire toutefois l'attention sur le fait que l'église Saint-Georges avec ces villages, dans ce cas, se serait retrouvé comme une possession isolée de Chilandar, entourée de possessions de Saint-Pantéléèmôn de sorte qu'il n'exclut non plus la possibilité qu'il soit question d'une donnée digne de foi. Par conséquent, une solution serait que Chilandar s'est peut-être vu dédommagée la perte de ces villages et de cette église sis à Pološko par la cession de villages sis dans une autre région. Finalement, Konstantin a également offert au monastère athonite russe deux autres églises — une sise à Štip et la seconde à Zletovo avec les droits leur appartenant. Les litiges apparus entre les moines de Chilandar et ceux de Saint-Pantéléèmôn au sujet de leur possessions limitrophes, sises sur la rive droite de la Strumica ont été résolus, sur ordre du gospodin Konstantin et du conseil de ses seigneurs par les évêques de Strumica et de Vodo?a en 1375/76. Puis, vers 1376/77, les frères Dragaš avec leur mère, l'impératrice Evdokija, ont confirmé à Saint-Pantéléèmôn la possession de villages sur la seule rive droite de la Strumica, ce faisant leur acte consigne de façon précise les droits de ces villages très probablement aux fins de prévenir tout nouveau litige avec les voisins de ces biens dans la jouissance de ceux-ci. Les donations des frères Dragaš en faveur de Chilandar s'avèrent également très nombreuses. Par un acte daté du 1er juin 1377 le despote Jovan et le gospodin Konstantin ont confirmé à Chilandar la possession durable et inaliénable de l'église Saint-Biaise à Štip et de trois villages sis dans les environs de cette ville. Ensuite, vers 1379 ou en 1380/81, l'impératr

  20. Fiction et typification.

    Directory of Open Access Journals (Sweden)

    Nathalie Zaccaï-Reyners

    2005-04-01

    Full Text Available Par quelles voies les acquis cognitifs de l’expérience sont-ils mobilisés par ego dans la suite de ses actions, et sont-ils transmis à autrui ? Contrairement à la phénoménologie sociale d’Alfred Schütz dans le cadre de laquelle ces questions sont renvoyées à des processus de généralisation et de stabilisation pensés sous le prisme de la typification sociale, la théorie des fictions élaborée par Jean-Marie Schaeffer appréhende la modélisation de l’expérience vécue à partir des spécificités d’une forme proprement ludique d’expérience. Les blocages décrits par Schütz lorsqu’il envisage les situations exemplaires de l’étranger ou du soldat revenant du front y trouvent un nouvel éclairage. Proposition de mots clés :How are cognitive elements of experience available for the continuation of ego’s action, and how are they passed on to alter ? In the social phenomenology of Alfred Schutz for instance, these questions are related back to generalisation and stabilisation processes viewed through the light of social typification. On the other hand, Jean-Marie Schaeffer’s theory of fiction comprehends the modelling of some lived experiences as the fact of a specific form of ludic experience. It provides a new light on the obstructions described by Schutz considering the exemplar situations of the stranger or of the homecomer.