WorldWideScience

Sample records for rhizobium etli final

  1. Rhizobium etli maize populations and their competitiveness for root colonization.

    Rosenblueth, Mónica; Martínez-Romero, Esperanza

    2004-05-01

    Rhizobium etli, which normally forms nitrogen-fixing nodules on Phaseolus vulgaris (common bean), is a natural maize endophyte. The genetic diversity of R. etli strains from bulk soil, bean nodules, the maize rhizosphere, the maize root, and inside stem tissue in traditional fields where maize is intercropped with P. vulgaris-beans was analyzed. Based on plasmid profiles and alloenzymes, it was determined that several R. etli types were preferentially encountered as putative maize endophytes. Some of these strains from maize were more competitive maize-root colonizers than other R. etli strains from the rhizosphere or from bean nodules. The dominant and highly competitive strain Ch24-10 was the most tolerant to 6-methoxy-2-benzoxazolinone (MBOA), a maize antimicrobial compound that is inhibitory to some bacteria and fungi. The R. tropici strain CIAT899, successfully used as inoculant of P. vulgaris, was also found to be a competitive maize endophyte in inoculation experiments. PMID:15024554

  2. Cloning and characterization of a thermostable xylitol dehydrogenase from Rhizobium etli CFN42

    Tiwari, Manish Kumar; Moon, Hee-Jung; Jeya, Marimuthu;

    2010-01-01

    An NAD(+)-dependent xylitol dehydrogenase from Rhizobium etli CFN42 (ReXDH) was cloned and overexpressed in Escherichia coli. The DNA sequence analysis revealed an open reading frame of 1,044 bp, capable of encoding a polypeptide of 347 amino acid residues with a calculated molecular mass of 35...

  3. Mechanisms of Inhibition of Rhizobium etli Pyruvate Carboxylase by l-Aspartate

    Sirithanakorn, Chaiyos; Adina-Zada, Abdussalam; Wallace, John C.; Jitrapakdee, Sarawut; Attwood, Paul V.

    2014-01-01

    l-Aspartate is a regulatory feedback inhibitor of the biotin-dependent enzyme pyruvate carboxylase in response to increased levels of tricarboxylic acid cycle intermediates. Detailed studies of l-aspartate inhibition of pyruvate carboxylase have been mainly confined to eukaryotic microbial enzymes, and aspects of its mode of action remain unclear. Here we examine its inhibition of the bacterial enzyme Rhizobium etli pyruvate carboxylase. Kinetic studies demonstrated that l-aspartate binds to ...

  4. Effective Symbiosis between Rhizobium etli and Phaseolus vulgaris Requires the Alarmone ppGpp

    Moris, Martine; Braeken, Kristien; Schoeters, Eric; Verreth, Christel; Beullens, Serge; Vanderleyden, Jos; Michiels, Jan

    2005-01-01

    The symbiotic interaction between Rhizobium etli and Phaseolus vulgaris, the common bean plant, ultimately results in the formation of nitrogen-fixing nodules. Many aspects of the intermediate and late stages of this interaction are still poorly understood. The R. etli relA gene was identified through a genome-wide screening for R. etli symbiotic mutants. RelA has a pivotal role in cellular physiology, as it catalyzes the synthesis of (p)ppGpp, which mediates the stringent response in bacteri...

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

    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 (π 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.

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

    Zhang, Ye-Wang; Tiwari, Manish Kumar; Jeya, Marimuthu;

    2011-01-01

    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......,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...

  7. A Functional Bacterium-to-Plant DNA Transfer Machinery of Rhizobium etli.

    Lacroix, Benoît; Citovsky, Vitaly

    2016-03-01

    Different strains and species of the soil phytopathogen Agrobacterium possess the ability to transfer and integrate a segment of DNA (T-DNA) into the genome of their eukaryotic hosts, which is mainly mediated by a set of virulence (vir) genes located on the bacterial Ti-plasmid that also contains the T-DNA. To date, Agrobacterium is considered to be unique in its capacity to mediate genetic transformation of eukaryotes. However, close homologs of the vir genes are encoded by the p42a plasmid of Rhizobium etli; this microorganism is related to Agrobacterium, but known only as a symbiotic bacterium that forms nitrogen-fixing nodules in several species of beans. Here, we show that R. etli can mediate functional DNA transfer and stable genetic transformation of plant cells, when provided with a plasmid containing a T-DNA segment. Thus, R. etli represents another bacterial species, besides Agrobacterium, that encodes a protein machinery for DNA transfer to eukaryotic cells and their subsequent genetic modification. PMID:26968003

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

    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.

  9. Rhizobium etli asparaginase II: an alternative for acute lymphoblastic leukemia (ALL) treatment.

    Huerta-Saquero, Alejandro; Evangelista-Martínez, Zahaed; Moreno-Enriquez, Angélica; Perez-Rueda, Ernesto

    2013-01-01

    Bacterial L-asparaginase has been a universal component of therapies for childhood acute lymphoblastic leukemia since the 1970s. Two principal enzymes derived from Escherichia coli and Erwinia chrysanthemi are the only options clinically approved to date. We recently reported a study of recombinant L-asparaginase (AnsA) from Rhizobium etli and described an increasing type of AnsA family members. Sequence analysis revealed four conserved motifs with notable differences with respect to the conserved regions of amino acid sequences of type I and type II L-asparaginases, particularly in comparison with therapeutic enzymes from E. coli and E. chrysanthemi. These differences suggested a distinct immunological specificity. Here, we report an in silico analysis that revealed immunogenic determinants of AnsA. Also, we used an extensive approach to compare the crystal structures of E. coli and E. chrysantemi asparaginases with a computational model of AnsA and identified immunogenic epitopes. A three-dimensional model of AsnA revealed, as expected based on sequence dissimilarities, completely different folding and different immunogenic epitopes. This approach could be very useful in transcending the problem of immunogenicity in two major ways: by chemical modifications of epitopes to reduce drug immunogenicity, and by site-directed mutagenesis of amino acid residues to diminish immunogenicity without reduction of enzymatic activity. PMID:22895060

  10. Rhizavidin from Rhizobium etli: the first natural dimer in the avidin protein family

    Helppolainen, Satu H.; Nurminen, Kirsi P.; Määttä, Juha A. E.; Halling, Katrin K.; Slotte, J. Peter; Huhtala, Tuulia; Liimatainen, Timo; Ylä-Herttuala, Seppo; Airenne, Kari J.; Närvänen, Ale; Jänis, Janne; Vainiotalo, Pirjo; Valjakka, Jarkko; Kulomaa, Markku S.; Nordlund, Henri R.

    2007-01-01

    Rhizobium etli CFN42 is a symbiotic nitrogen-fixing bacterium of the common bean Phaseolus vulgaris. The symbiotic plasmid p42d of R. etli comprises a gene encoding a putative (strept)avidin-like protein, named rhizavidin. The amino acid sequence identity of rhizavidin in relation to other known avidin-like proteins is 20–30%. The amino acid residues involved in the (strept)avidin–biotin interaction are well conserved in rhizavidin. The structural and functional properties of rhizavidin were carefully studied, and we found that rhizavidin shares characteristics with bradavidin, streptavidin and avidin. However, we found that it is the first naturally occurring dimeric protein in the avidin protein family, in contrast with tetrameric (strept)avidin and bradavidin. Moreover, it possesses a proline residue after a flexible loop (GGSG) in a position close to Trp-110 in avidin, which is an important biotin-binding residue. [3H]Biotin dissociation and ITC (isothermal titration calorimetry) experiments showed dimeric rhizavidin to be a high-affinity biotin-binding protein. Its thermal stability was lower than that of avidin; although similar to streptavidin, it was insensitive to proteinase K. The immunological cross-reactivity of rhizavidin was tested with human serum samples obtained from cancer patients exposed to (strept)avidin. No significant cross-reactivity was observed. The biodistribution of the protein was studied by SPECT (single-photon emission computed tomography) imaging in rats. Similarly to avidin, rhizavidin was observed to accumulate rapidly, mainly in the liver. Evidently, rhizavidin could be used as a complement to (strept)avidin in (strept)avidin–biotin technology. PMID:17447892

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

    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.

  12. Genetic Basis for Rhizobium etli CE3 O-Antigen O-Methylated Residues That Vary According to Growth Conditions▿

    Ojeda, Kristylea J.; Box, Jodie M.; Noel, K. Dale

    2009-01-01

    The Rhizobium etli CE3 O antigen is a fixed-length heteropolymer with O methylation being the predominant type of sugar modification. There are two O-methylated residues that occur, on average, once per complete O antigen: a multiply O-methylated terminal fucose and 2-O methylation of a fucose residue within a repeating unit. The amount of the methylated terminal fucose decreases and the amount of 2-O-methylfucose increases when bacteria are grown in the presence of the host plant, Phaseolus ...

  13. Host genes involved in nodulation preference in common bean (Phaseolus vulgaris)-rhizobium etli symbiosis revealed by suppressive subtractive hybridization.

    Meschini, Eitel Peltzer; Blanco, Flavio Antonio; Zanetti, María Eugenia; Beker, María Pía; Küster, Helge; Pühler, Alfred; Aguilar, O Mario

    2008-04-01

    Common bean cultivars are nodulated preferentially by Rhizobium etli lineages from the same center of host diversification. Nodulation was found to be earlier and numerous in bean plants inoculated with the cognate strain. We predicted that analysis of transcripts at early stages of the interaction between host and rhizobium would identify plant genes that are most likely to be involved in this preferential nodulation. Therefore, we applied a suppressive subtractive hybridization approach in which cDNA from a Mesoamerican cultivar inoculated with either the more- or less-efficient strain of R. etli was used as the driver and the tester, respectively. Forty-one independent tentative consensus sequences (TCs) were obtained and classified into different functional categories. Of 11 selected TCs, 9 were confirmed by quantitative reverse-transcriptase polymerase chain reaction. Two genes show high homology to previously characterized plant receptors. Two other upregulated genes encode for Rab11, a member of the small GTP-binding protein family, and HAP5, a subunit of the heterotrimeric CCAAT-transcription factor. Interestingly, one of the TCs encodes for an isoflavone reductase, which may lead to earlier Nod factor production by specific strains of rhizobia. The transcript abundance of selected cDNAs also was found to be higher in mature nodules of the more efficient interaction. Small or no differences were observed when an Andean bean cultivar was inoculated with a cognate strain, suggesting involvement of these genes in the strain-specific response. The potential role of these genes in the early preferential symbiotic interaction is discussed. PMID:18321191

  14. Conservation of Plasmid-Encoded Traits among Bean-Nodulating Rhizobium Species

    Brom, Susana; Girard, Lourdes; García-de los Santos, Alejandro; Sanjuan-Pinilla, Julio M.; Olivares, José; Sanjuan, Juan

    2002-01-01

    Rhizobium etli type strain CFN42 contains six plasmids. We analyzed the distribution of genetic markers from some of these plasmids in bean-nodulating strains belonging to different species (Rhizobium etli, Rhizobium gallicum, Rhizobium giardinii, Rhizobium leguminosarum, and Sinorhizobium fredii). Our results indicate that independent of geographic origin, R. etli strains usually share not only the pSym plasmid but also other plasmids containing symbiosis-related genes, with a similar organi...

  15. Region 4 of Rhizobium etli Primary Sigma Factor (SigA) Confers Transcriptional Laxity in Escherichia coli

    Santillán, Orlando; Ramírez-Romero, Miguel A.; Lozano, Luis; Checa, Alberto; Encarnación, Sergio M.; Dávila, Guillermo

    2016-01-01

    Sigma factors are RNA polymerase subunits engaged in promoter recognition and DNA strand separation during transcription initiation in bacteria. Primary sigma factors are responsible for the expression of housekeeping genes and are essential for survival. RpoD, the primary sigma factor of Escherichia coli, a γ-proteobacteria, recognizes consensus promoter sequences highly similar to those of some α-proteobacteria species. Despite this resemblance, RpoD is unable to sustain transcription from most of the α-proteobacterial promoters tested so far. In contrast, we have found that SigA, the primary sigma factor of Rhizobium etli, an α-proteobacteria, is able to transcribe E. coli promoters, although it exhibits only 48% identity (98% coverage) to RpoD. We have called this the transcriptional laxity phenomenon. Here, we show that SigA partially complements the thermo-sensitive deficiency of RpoD285 from E. coli strain UQ285 and that the SigA region σ4 is responsible for this phenotype. Sixteen out of 74 residues (21.6%) within region σ4 are variable between RpoD and SigA. Mutating these residues significantly improves SigA ability to complement E. coli UQ285. Only six of these residues fall into positions already known to interact with promoter DNA and to comprise a helix-turn-helix motif. The remaining variable positions are located on previously unexplored sites inside region σ4, specifically into the first two α-helices of the region. Neither of the variable positions confined to these helices seem to interact directly with promoter sequence; instead, we adduce that these residues participate allosterically by contributing to correct region folding and/or positioning of the HTH motif. We propose that transcriptional laxity is a mechanism for ensuring transcription in spite of naturally occurring mutations from endogenous promoters and/or horizontally transferred DNA sequences, allowing survival and fast environmental adaptation of α-proteobacteria. PMID

  16. Caracterización fisiológica y molecular de la interacción Phaseolus (vulgaris: Rhizobium etli)

    Beker, María Pía

    2010-01-01

    En este trabajo de tesis se utilizó el sistema P. vulgaris-R. etli como modelo para investigar la afinidad entre porotos pertenecientes a los centros de diversificación de Mesoamérica y de la región Andina sureña y los rizobios de esas regiones. Teniendo en cuenta los eventos que se desarrollan desde el inicio del diálogo molecular hasta la formación del nódulo fijador de nitrógeno, el presente trabajo de tesis pretende contribuir al conocimiento de la interacción entre genotipos de poroto...

  17. Evolution of rhizobium symbiosis

    Camp, Op den R.H.M.

    2012-01-01

    The evolution of rhizobium symbiosis is studied from several points of view in this thesis. The ultimate goal of the combined approaches is to unravel the genetic constrains of the symbiotic interaction. To this end the legume rhizobium symbiosis is studied in model plant species from the Papilionoi

  18. 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.

    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

  19. 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[C][W

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

    2010-01-01

    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

  20. Regulation of tryptophan genes in Rhizobium leguminosarum.

    Holmgren, E; I. P. Crawford

    1982-01-01

    Twelve tryptophan auxotrophs of Rhizobium leguminosarum were characterized biochemically. They were grown in complex and minimal media with several carbon sources, in both limiting and excess tryptophan. Missing enzyme activities allowed assignment of all mutant to the trpE, trpD, trpB, or trpA gene, confirming earlier results with the same mutants (Johnston et al., Mol. Gen. Genet. 165:323-330, 1978). In regulatory experiments, only the first enzyme of the pathway, anthranilate synthase, res...

  1. Average nucleotide identity of genome sequences supports the description of Rhizobium lentis sp. nov., Rhizobium bangladeshense sp. nov. and Rhizobium binae sp. nov. from lentil (Lens culinaris) nodules.

    Rashid, M Harun-or; Young, J Peter W; Everall, Isobel; Clercx, Pia; Willems, Anne; Santhosh Braun, Markus; Wink, Michael

    2015-09-01

    Rhizobial strains isolated from effective root nodules of field-grown lentil (Lens culinaris) from different parts of Bangladesh were previously analysed using sequences of the 16S rRNA gene, three housekeeping genes (recA, atpD and glnII) and three nodulation genes (nodA, nodC and nodD), DNA fingerprinting and phenotypic characterization. Analysis of housekeeping gene sequences and DNA fingerprints indicated that the strains belonged to three novel clades in the genus Rhizobium. In present study, a representative strain from each clade was further characterized by determination of cellular fatty acid compositions, carbon substrate utilization patterns and DNA-DNA hybridization and average nucleotide identity (ANI) analyses from whole-genome sequences. DNA-DNA hybridization showed 50-62% relatedness to their closest relatives (the type strains of Rhizobium etli and Rhizobium phaseoli) and 50-60% relatedness to each other. These results were further supported by ANI values, based on genome sequencing, which were 87-92% with their close relatives and 88-89% with each other. On the basis of these results, three novel species, Rhizobium lentis sp. nov. (type strain BLR27(T) = LMG 28441(T) = DSM 29286(T)), Rhizobium bangladeshense sp. nov. (type strain BLR175(T) = LMG 28442(T) = DSM 29287(T)) and Rhizobium binae sp. nov. (type strain BLR195(T) = LMG 28443(T) = DSM 29288(T)), are proposed. These species share common nodulation genes (nodA, nodC and nodD) that are similar to those of the symbiovar viciae. PMID:26060217

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

    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...

  3. Elucidation of a novel lipid A α-(1,1)-GalA transferase gene (rgtF) from Mesorhizobium loti: Heterologous expression of rgtF causes Rhizobium etli to synthesize lipid A with α-(1,1)-GalA.

    Brown, Dusty B; Muszynski, Artur; Carlson, Russell W

    2013-05-01

    An unusual α-(1,1)-galacturonic acid (GalA) lipid A modification has been reported in the lipopolysaccharide of a number of interesting Gram-negative bacteria, including the nitrogen-fixing bacteria Azospirillum lipoferum, Mesorhizobium huakuii and M. loti, the stalk-forming bacterium Caulobacter crescentus and the hyperthermophilic bacterium Aquifex aeolicus. However, the α-(1,1)-GalA transferase (GalAT) gene, which we have named RgtF, was not identified. Species of the Rhizobium genera produce lipid A with α-(1,4')-GalA but not α-(1,1)-GalA. The Rhizobium GalAT, RgtD, is the lipid A α-(1-4')-GalAT which utilizes the lipid donor dodecaprenyl-phosphate GalA (Dod-P-GalA) for GalA transfer. An additional Rhizobium GalAT, RgtE, is required for the biosynthesis of Dod-P-GalA. We predicted candidate rgtF genes in bacterial species known to produce lipid A with α-(1,1)-GalA. In order to determine the predicted rgtF gene function, we cloned the M. loti rgtF gene into an expression plasmid and introduced that plasmid into Rhizobium etli strains that do not contain the rgtF gene nor produce lipid A α-(1,1)-GalA. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis combined with NMR studies revealed that the lipid As from these rgtF-complemented strains were modified with an additional α-(1,1)-GalA attached to the proximal glucosamine. PMID:23283001

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

    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.

  5. Tryptophan auxotrophs of Rhizobium japonicum.

    Wells, S E; Kuykendall, L D

    1983-01-01

    Eleven tryptophan-requiring mutants of Rhizobium japonicum I-110 ARS were isolated after nitrous acid mutagenesis and fell into five groups based on characterization by supplementation with intermediates and enzyme assays.

  6. Change in land use alters the diversity and composition of Bradyrhizobium communities and led to the introduction of Rhizobium etli into the tropical rain forest of Los Tuxtlas (Mexico).

    Ormeño-Orrillo, Ernesto; Rogel-Hernández, Marco A; Lloret, Lourdes; López-López, Aline; Martínez, Julio; Barois, Isabelle; Martínez-Romero, Esperanza

    2012-05-01

    Nitrogen-fixing bacteria of the Bradyrhizobium genus are major symbionts of legume plants in American tropical forests, but little is known about the effects of deforestation and change in land use on their diversity and community structure. Forest clearing is followed by cropping of bean (Phaseolus vulgaris) and maize as intercropped plants in Los Tuxtlas tropical forest of Mexico. The identity of bean-nodulating rhizobia in this area is not known. Using promiscuous trap plants, bradyrhizobia were isolated from soil samples collected in Los Tuxtlas undisturbed forest, and in areas where forest was cleared and land was used as crop fields or as pastures, or where secondary forests were established. Rhizobia were also trapped by using bean plants. Bradyrhizobium strains were classified into genospecies by dnaK sequence analysis supported by recA, glnII and 16S-23S rDNA IGS loci analyses. A total of 29 genospecies were identified, 24 of which did not correspond to any described taxa. A reduction in Bradyrhizobium diversity was observed when forest was turned to crop fields or pastures. Diversity seemed to recover to primary forest levels in secondary forests that derived from abandoned crop fields or pastures. The shifts in diversity were not related to soil characteristics but seemingly to the density of nodulating legumes present at each land use system (LUS). Bradyrhizobium community composition in soils was dependent on land use; however, similarities were observed between crop fields and pastures but not among forest and secondary forest. Most Bradyrhizobium genospecies present in forest were not recovered or become rare in the other LUS. Rhizobium etli was found as the dominant bean-nodulating rhizobia present in crop fields and pastures, and evidence was found that this species was introduced in Los Tuxtlas forest. PMID:22109095

  7. 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

    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 γ-proteobacteria but lately in several α-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 α-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 α-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 α-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.

  8. Physiology of the Rhizobium-legume association

    Rhizobium deoxyribonucleic acid has been detected within Vicia faba root cells by in situ hybridization and autoradiography after exposure of root apexes to Rhizobium viable cells. Reannealed regions are localized in the cortex cells; the presence of bacterial DNA is specific for the root tissue; labelled regions were not detectable within apexes exposed to non-nodulating strains or to bacteria other than Rhizobium; Rhizobium DNA was not detectable in tissues of plants other than its leguminous host

  9. Denitrification by Rhizobium meliloti

    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

  10. Tanggapan Tanaman Kedelai terhadap Inokulasi Rhizobium

    OKTI PURWANINGSIH; DIDIK INDRADEWA; SITI KABIRUN; DJAFFAR SHIDDIQ

    2013-01-01

    Nitrogen is one important element in plant growth. In soybean crop nitrogen requirement can bemet from the fixation of nitrogen which is the result of symbiosis between rhizobium bacteria withsoybean. A study on the relationship between soybean cultivar and rhizobium inoculation was conductedin Banguntapan Bantul Yogyakarta on regusol soils. Research aimed the responses of soybean cultivarof rhizobium inoculation. This research is a pot experiment that tested the response of 16 soybeancultiva...

  11. Polyol metabolism by Rhizobium trifolii.

    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...

  12. Peritonitis due to Rhizobium radiobacter

    Marta, R; Dâmaso, C; Silva, JE; M.De Almeida

    2011-01-01

    Rhizobium radiobacter (Agrobacterium radiobacter) is an aerobic Gram-negative rod belonging to Agrobacterium genus, a group of phytopathogenic bacteria present in the soil that has been implicated in human opportunistic infections. We report a clinical case of bacterial peritonitis in a 5-year-old child with chronic renal disease in peritoneal dialysis, who had a history of direct soil contact identified. The infection was treated with ceftazidime and piperaciline+tazobactam without relapses ...

  13. Tanggapan Tanaman Kedelai terhadap Inokulasi Rhizobium

    OKTI PURWANINGSIH

    2013-08-01

    Full Text Available Nitrogen is one important element in plant growth. In soybean crop nitrogen requirement can bemet from the fixation of nitrogen which is the result of symbiosis between rhizobium bacteria withsoybean. A study on the relationship between soybean cultivar and rhizobium inoculation was conductedin Banguntapan Bantul Yogyakarta on regusol soils. Research aimed the responses of soybean cultivarof rhizobium inoculation. This research is a pot experiment that tested the response of 16 soybeancultivars of rhizobium inoculation. The sixteen cultivars consisted of 12 superior cultivars and 4 localcultivars. Before planting soybean seeds were inoculated with legin. Land used first sterilized usingautoclaves. Determination of soybean cultivars into four categories based on agronomic charactersnodule number, nodule dry weight, canopy N content, nitrogenase activity and grain yield components(seed dry weight. The study demonstrated that (1 Cultivars Anjasmara, Sibayak, Surya, Gepak yellow,Galunggung, Argomulyo and Baluran provide a response to rhizobium inoculation in the form of increasednitrogen fixation and grain yield (2 rhizobium inoculation on Tanggamus cultivars can increase nitrogenfixation but not followed by an increase in grain yield (3 rhizobium inoculation in cultivar Malabar,Seulawah and Petek not increase nitrogen fixation but can increase grain yield (4 rhizobium inoculationin cultivar Ijen, Sinabung, Wilis, Grobogan, and Garut not increase nitrogen fixation and grain yield.

  14. 77 FR 10560 - United States v. International Paper Company et al.; Proposed Final Judgment and Competitive...

    2012-02-22

    ... obligations and perform all of their responsibilities under the Final Judgment and the Asset Preservation... have held that: he balancing of competing social and political interests affected by a proposed... Antitrust Division United States v. International Paper Company et al.; Proposed Final Judgment...

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

    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 : 1ω7c, 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

  16. Effect of Plasmid pIJ1008 from Rhizobium leguminosarum on Symbiotic Function of Rhizobium meliloti

    E.J Bedmar; Brewin, N J; Phillips, D A

    1984-01-01

    Plasmid pIJ1008, which carries determinants for uptake hydrogenase (Hup) activity, was transferred from Rhizobium leguminosarum to Rhizobium meliloti without impairing the capacity of the latter species to form root nodules on alfalfa. The plasmid was still present in rhizobia reisolated from the root nodules of 12 different alfalfa cultivars, but only low levels of Hup activity were detected in alfalfa.

  17. Optimization of Dairy Sludge for Growth of Rhizobium Cells

    Ashok Kumar Singh; Gauri Singh; Digvijay Gautam; Manjinder Kaur Bedi

    2013-01-01

    In this study dairy sludge was evaluated as an alternative cultivation medium for Rhizobium. Growth of bacterial strains at different concentrations of Dairy sludge was monitored. Maximum growth of all strains was observed at 60% Dairy sludge concentration. At 60% optical density (OD) values are 0.804 for Rhizobium trifolii (MTCC905), 0.825 for Rhizobium trifolii (MTCC906), and 0.793 for Rhizobium meliloti (MTCC100). Growth pattern of strains was observed at 60% Dairy sludge along with differ...

  18. Expressão dos genes nod de Rhizobium tropici, R. etli e R. leguminosarum bv. phaseoli e estabelecimento da nodulação do feijoeiro na presença de exsudatos de sementes de Mimosa flocculosa e Leucaena leucocephala

    F. M. Mercante

    2000-06-01

    Full Text Available Na etapa inicial da troca de sinais moleculares entre macro e microssimbiontes, a interação do feijoeiro e estirpes de Rhizobium tropici, R. etli e R. leguminosarum bv. phaseoli foi avaliada pela expressão dos genes nod de estirpes bacterianas, contendo a fusão nodA::gusA. Esta avaliação foi efetuada por meio da atividade da enzima ß-glucuronidase, utilizando, como indutores, exsudatos liberados pelas sementes de Mimosa flocculosa e Leucaena leucocephala. Além disso, avaliou-se o efeito da adição desses exsudatos no estabelecimento da nodulação do feijoeiro, cv. Carioca. Nos testes "in vitro", a mistura de exsudatos de sementes de feijoeiro e M. flocculosa promoveu aumentos sinergísticos significativos na expressão dos genes nod, tanto das estirpes de R. tropici (CIAT 899/pGUS 32 e F 98.5/pGUS 32 quanto de R. etli (CFN 42/pGUS 32. Em condições controladas, a adição dos exsudatos, tanto de M. flocculosa quanto de L. leucocephala, proporcionou aumento significativo na nodulação inicial do feijoeiro, quando foi inoculada a estirpe CFN 42 (R. etli. A nodulação do feijoeiro cultivado em vasos com solo não foi inibida pelo suprimento de N-mineral, quando se inoculou a estirpe CIAT 899 (R. tropici e foram fornecidos exsudatos de sementes de M. flocculosa.

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

    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.

  20. Optimizing Gateway™ technology (Invitrogen) to construct Rhizobium leguminosarum deletion mutants

    Lanza Lucio, Monica; Alborno, Marcelo; Rey Navarro, Luis; Imperial Ródenas, Juan

    2010-01-01

    The study of the role of different genes in Rhizobium leguminosarum requires the generation of mutants by homologous recombination. In this communication we describe a novel approach to obtain deletion mutants of genes in Rhizobium using Gateway TM Cloning technology (Invitrogen) and a new vector (pK18-attR), both conjugative and Rhizobium specific, that carries the recombination tails of Gateway system. This tool is a new alternative to the classic approach based on cloning using rest...

  1. Recognition of Leguminous Hosts by a Promiscuous Rhizobium Strain

    Shantharam, S; Wong, Peter P.

    1982-01-01

    The lima bean (Phaseolus lunatus L.) and the pole bean (Phaseolus vulgaris L.) are nodulated by rhizobia of two different cross-inoculation groups. Rhizobium sp. 127E15, a cowpea-type Rhizobium, can induce effective nodules on the lima bean and partially effective nodules on the pole bean. Rhizobium phaseoli 127K14 can induce effective nodules on the pole bean but does not reciprocally nodulate the lima bean. Root hairs of the lima bean when inoculated with Rhizobium sp. 127E15 showed tip cur...

  2. 77 FR 10775 - United States v. SG Interests I LTD., et al.; Proposed Final Judgment and Competitive Impact...

    2012-02-23

    ... Antitrust Division United States v. SG Interests I LTD., et al.; Proposed Final Judgment and Competitive.... SG Interests I, Ltd. et al., Civil Action No. 12- CV-00395-RPM-MEH. On February 15, 2012, the United States filed a civil antitrust Complaint alleging that the SG Interests I Ltd. and SG Interests VII...

  3. Biodegradation of Phosphonomycin by Rhizobium huakuii PMY1

    McGrath, John W.; Hammerschmidt, Friedrich; Quinn, John P.

    1998-01-01

    The biodegradation by Rhizobium huakuii PMY1 of up to 10 mM phosphonomycin as a carbon, energy, and phosphorus source with accompanying Pi release is described. This biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by Rhizobium spp.

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

    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.

  5. (A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis)

    Hollingsworth, R.I.

    1991-01-01

    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.

  6. Rhizobium nodM and nodN genes are common nod genes: nodM encodes functions for efficiency of nod signal production and bacteroid maturation.

    Baev, N; Schultze, M; Barlier, I; Ha, D C; Virelizier, H.; Kondorosi, E.; Kondorosi, A

    1992-01-01

    Earlier, we showed that Rhizobium meliloti nodM codes for glucosamine synthase and that nodM and nodN mutants produce strongly reduced root hair deformation activity and display delayed nodulation of Medicago sativa (Baev et al., Mol. Gen. Genet. 228:113-124, 1991). Here, we demonstrate that nodM and nodN genes from Rhizobium leguminosarum biovar viciae restore the root hair deformation activity of exudates of the corresponding R. meliloti mutant strains. Partial restoration of the nodulation...

  7. Rhizobium calliandrae sp. nov., Rhizobium mayense sp. nov. and Rhizobium jaguaris sp. nov., rhizobial species nodulating the medicinal legume Calliandra grandiflora.

    Rincón-Rosales, Reiner; Villalobos-Escobedo, José M; Rogel, Marco A; Martinez, Julio; Ormeño-Orrillo, Ernesto; Martínez-Romero, Esperanza

    2013-09-01

    Calliandra grandiflora has been used as a medicinal plant for thousands of years in Mexico. Rhizobial strains were obtained from root nodules of C. grandiflora collected from different geographical regions in Chiapas and characterized by BOX-PCR, amplified rDNA restriction analysis (ARDRA) and 16S rRNA gene sequence analysis. Most isolates corresponded to members of the genus Rhizobium and those not related to species with validly published names were further characterized by recA, atpD, rpoB and nifH gene phylogenies, phenotypic and DNA-DNA hybridization analyses. Three novel related species of the genus Rhizobium within the 'Rhizobium tropici group' share the same symbiovar that may be named sv. calliandrae. The names proposed for the three novel species are Rhizobium calliandrae sp. nov. (type strain, CCGE524(T) =ATCC BAA-2435(T) =CIP 110456(T) =LBP2-1(T)), Rhizobium mayense sp. nov. (type strain, CCGE526(T) =ATCC BAA-2446(T) = CIP 110454(T) =NSJP1-1(T)) and Rhizobium jaguaris sp. nov. (type strain, CCGE525(T) =ATCC BAA-2445(T) =CIP 110453(T) =SJP1-2(T)). PMID:23584283

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

    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...

  9. 75 FR 12256 - United States, et al. v. Election Systems and Software, Inc.; Proposed Final Judgment and...

    2010-03-15

    ... the design and development of hardware, software and firmware products, but also obtaining multiple... Antitrust Division United States, et al. v. Election Systems and Software, Inc.; Proposed Final Judgment and.... v. Election Systems and Software Inc., Civil Action No. 10-00380. On March 8, 2010, the...

  10. 76 FR 68210 - United States v. George's Foods, LLC, et al.; Public Comment and Response on Proposed Final Judgment

    2011-11-03

    ... United States v. George's Foods, Inc., et. al., 76 FR 38419; and summaries of the terms of the proposed... of its buyer power;'' (2) an extension of the termination date of the proposed Final Judgment to... a buyer (such as George's buying services from growers) with market power will reduce purchases...

  11. Comparative properties of glutamine synthetases I and II in Rhizobium and Agrobacterium spp.

    Fuchs, R L; Keister, D L

    1980-01-01

    Some properties of glutamine synthetase I (GSI) and GSII are described for a fast-growing Rhizobium sp. (Rhizobium trifolii T1), a slow-growing Rhizobium sp. (Rhizobium japonicum USDA 83), and Agrobacterium tumefaciens C58. GSII of the fast-growing Rhizobium sp. and GSII of the Agrobacterium sp. were considerably more heat labile than GSII of the slow-growing Rhizobium sp. As previously shown in R. japonicum 61A76, GSI became adenylylated rapidly in all species tested in response to ammonium....

  12. Rhizobium leguminosarum mutants incapable of normal extracellular polysaccharide production.

    Napoli, C; Albersheim, P

    1980-01-01

    Mutants of Rhizobium leguminosarum which are deficient in normal polysaccharide production have been isolated and characterized. A correlation between diminished production of extracellular polysaccharide and reduced infection and nodulation efficiency has been observed.

  13. Variability among Rhizobium Strains Originating from Nodules of Vicia faba

    van Berkum, P.; Beyene, D; Vera, F. T.; Keyser, H. H.

    1995-01-01

    Rhizobium strains from nodules of Vicia faba were diverse in plasmid content and serology. Results of multilocus gel electrophoresis and restriction fragment length polymorphism indicated several deep chromosomal lineages among the strains. Linkage disequilibrium among the chromosomal types was detected and may have reflected variation of Rhizobium strains in the different geographical locations from which the strains originated. An investigation of pea strains with antibodies prepared agains...

  14. Reiterated DNA Sequences in Rhizobium and Agrobacterium spp

    Flores, M.; González, V.; Brom, S; Martínez, E.; Piñero, D; Romero, D.; Dávila, G; Palacios, R

    1988-01-01

    Repeated DNA sequences are a general characteristic of eucaryotic genomes. Although several examples of DNA reiteration have been found in procaryotic organisms, only in the case of the archaebacteria Halobacterium halobium and Halobacterium volcanii [C. Sapienza and W. F. Doolittle, Nature (London) 295:384-389, 1982], has DNA reiteration been reported as a common genomic feature. The genomes of two Rhizobium phaseoli strains, one Rhizobium meliloti strain, and one Agrobacterium tumefaciens s...

  15. D'une ouverture de la voyelle /epsilon/ en finale absolue en francais quebecois : analyse acoustique et perceptive

    Riverin-Coutlee, Josiane

    Cette contribution est consacree a l'ouverture du /epsilon/ en finale absolue, un phenomene phonetique repute etre en declin en francais quebecois et caracteristique de locuteurs âges, peu scolarises, issus de milieux populaires et s'exprimant en situation de communication informelle. Une analyse acoustique de 480 voyelles /epsilon/ issues de la parole formelle de 40 jeunes etudiants universitaires originaires des centres urbains de Saguenay et de Quebec revele toutefois que le phenomene est encore bien vivant en francais quebecois et qu'il est plus frequent chez les locuteurs de Saguenay, une tendance validee auditivement par accord inter-juges. Les resultats d'un test de discrimination et d'identification mene aupres de 26 etudiants universitaires originaires de ces deux memes villes indiquent que les auditeurs naifs de Saguenay semblent moins sensibles a la variation et moins enclins a juger de l'origine geographique d'un locuteur a partir de sa prononciation de la voyelle /epsilon/ en fin de mot.

  16. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper

    Xuecheng Zheng; Dongwei Li

    2016-01-01

    This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 108 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in th...

  17. Rhizobium helianthi sp. nov., isolated from the rhizosphere of sunflower.

    Wei, Xuexin; Yan, Shouwei; Li, Dai; Pang, Huancheng; Li, Yuyi; Zhang, Jianli

    2015-12-01

    A Gram-stain-negative, non-spore-forming, rod-shaped and aerobic bacterium, designated Xi19T, was isolated from a soil sample collected from the rhizosphere of sunflower (Helianthus annuus) in Wuyuan county of Inner Mongolia, China and was characterized taxonomically by using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate was related to species of the genus Rhizobium, sharing the greatest 16S rRNA gene sequence similarity with Rhizobium rhizoryzae J3-AN59T (98.4 %), followed by Rhizobium pseudoryzae J3-A127T (97.4 %). There were low similarities ( < 91 %) between the atpD, recA and glnII gene sequences of the novel strain and those of members of the genus Rhizobium. DNA-DNA hybridization values between strain Xi19T and the most related strain Rhizobium rhizoryzae J3-AN59T were low. The major cellular fatty acids of strain Xi19T were C16 : 0, summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C19 : 0 cyclo ω8c. Q-10 was identified as the predominant ubiquinone and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The DNA G+C content of strain Xi19T was 60.2 mol%. On the basis of physiological and biochemical characteristics, coupled with genotypic data obtained in this work, strain Xi19T represents a novel species of the genus Rhizobium, for which the name Rhizobium helianthi is proposed. The type strain is Xi19T ( = CGMCC 1.12192T = KCTC 23879T). PMID:26364048

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

    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.

  19. Rhizobium petrolearium sp. nov., isolated from oil-contaminated soil.

    Zhang, Xiaoxia; Li, Baoming; Wang, Haisheng; Sui, Xinhua; Ma, Xiaotong; Hong, Qing; Jiang, Ruibo

    2012-08-01

    Two Gram-negative, aerobic, rod-shaped bacteria, designated strains SL-1(T) and F11, which had the ability to decompose polycyclic aromatic hydrocarbons (PAHs), were isolated from soil samples contaminated by oil. The cells were motile by polar or lateral flagella. According to comparison of 16S rRNA gene sequences, strains SL-1(T) and F11 were identical and showed the greatest degree of similarity (96.8%) to both Rhizobium oryzae Alt505(T) and Rhizobium mesosinicum CCBAU 25010(T); however, only Rhizobium oryzae with SL-1(T) and F11 formed a separate clade. There were low similarities (SL-1(T) showed 29 and 0% DNA-DNA relatedness, respectively, with the most related strains R. oryzae Alt505(T) and R. mesosinicum CCBAU 25010(T) according to phylogenic analysis of the 16S rRNA gene. According to physiological and biochemical characteristics and genotypic data obtained in this work, the bacteria represent a novel species of the genus Rhizobium, and the name Rhizobium petrolearium is proposed. The type strain is SL-1(T) ( = ACCC 11238(T) = KCTC 23288(T)) and it could nodulate Medicago sativa in nodulation tests. PMID:21984664

  20. Production of Poly-b-Hydroxybutyrate (PHB) by Some Rhizobium Bacteria

    MERCAN, Nazime

    2002-01-01

    In this study, the production of Poly-b-hydroxybutyrate (PHB) was determined in 1 Rhizobium japonicum, 6 Rhizobium cicer, 8 Rhizobium spp. and Bradyrhizobium japonicum USDA 110. The content of according to dry cell weight was determined to be 1.38-40.0%. In our study, Rhizobium spp. 2426, which produced the highest percentage yield of PHB, and Rhizobium spp. 640, which produced the intermediate percentage yield of PHB, were first selected among all the strains, and then the effect of differen...

  1. Physiological role of calcium in legume-rhizobium symbiosis

    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.

  2. Identification of Rhizobium-specific intergenic mosaic elements within an essential two-component regulatory system of Rhizobium species.

    Osterås, M; Stanley, J; Finan, T. M.

    1995-01-01

    Analysis of the DNA regions upstream of the phosphoenolpyruvate carboxykinase gene (pckA) in Rhizobium meliloti and Rhizobium sp. strain NGR234 identified an open reading frame which was highly homologous to the Agrobacterium tumefaciens chromosomal virulence gene product ChvI. A second gene product, 500 bp downstream of the chvI-like gene in R. meliloti, was homologous to the A. tumefaciens ChvG protein. The homology between the R. meliloti and A. tumefaciens genes was confirmed, because the...

  3. Towards in vivo imaging of early Rhizobium Nod factor responses

    Krogt, van der G.N.M.

    2006-01-01

    The goal in this thesis is to explore the possibility of live imaging of cellular events using fluorescence microscopy in combination with Green Fluorescent Protein (GFP) based reporter constructs in root hairs during theRhizobium-legume interaction. Legumes have the abilit

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

    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...

  5. Diversity of Rhizobium leguminosarum from pea fields in Washington State

    Rhizobia-mediated biological nitrogen (N) fixation in legumes contributes to yield potential in these crops and also provides residual fertilizer to subsequent cereals. Our objectives were to collect isolates of Rhizobium leguminosarum from several pea fields in Washington, examine genetic diversity...

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

    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.

  7. The effect of exogenous rhizobial lipopolysaccharide on symbiosis of Rhizobium leguminosarum bv. trifolii with red clover

    Maria Głowacka

    2014-02-01

    Full Text Available The effectivity of symbiosis of Rhizobium leguminosarum bv. trifolii with red clover in the presence of exogenous lipopolysaccharide (LPS preparation was measured as a yield of green mass of infected plants. The addition of complete LPS that had been obtained from homological Rhizobium strains influenced significantly the growth of plants. In the presence of defective LPS of Rhizobium mutant the effectivity of symbiosis did not change.

  8. Populasi Bakteri Rhizobium di Tanah pada beberapa Tanaman dari Pulau Buton, Kabupaten Muna, Propinsi Sulawesi Tenggara

    Sri Purwaningsih

    2009-01-01

    The research was conducted in order to know population of Rhizobium bacteria in the soil at several plant from Buton island, Muna regency, Southeast Sulawesi. The purpose of the study was to get the population data and pure cultures of Rhizobium bacteria. Rhizobium bacteria were isolated from 13 sample from rhizosphere of fruit plant, 14 sample soil from rhizosphere of yield plant, 5 sample soil from rhizosphere of horticulture plant, and 8 samples soil was from forest plant. Isolation was c...

  9. The effect of exogenous rhizobial lipopolysaccharide on symbiosis of Rhizobium leguminosarum bv. trifolii with red clover

    Maria Głowacka; Agnieszka Stępień; Sylwia Szyprowska

    2014-01-01

    The effectivity of symbiosis of Rhizobium leguminosarum bv. trifolii with red clover in the presence of exogenous lipopolysaccharide (LPS) preparation was measured as a yield of green mass of infected plants. The addition of complete LPS that had been obtained from homological Rhizobium strains influenced significantly the growth of plants. In the presence of defective LPS of Rhizobium mutant the effectivity of symbiosis did not change.

  10. Interaction of Azospirillum and Rhizobium Strains Leading to Inhibition of Nodulation

    Plazinski, Jacek; Rolfe, Barry G.

    1985-01-01

    Rhizobium-Azospirillum interactions during establishment of Rhizobium-clover symbiosis were studied. When mixed cultures of Azospirillum and Rhizobium trifolii strains were simultaneously inoculated onto clover plants, no nodulation by R. trifolii was observed. R. trifolii ANU1030, which nodulated clover plants without attacking root hairs, i.e., does not cause root hair curling (Hac−), did not show inhibition of nodulation when inoculated together with Azospirillum strains. Isolation of bact...

  11. PENGARUH pH MEDIA PERTUMBUHAN TERHADAP KETAHANAN DARI Rhizobium sp. PADA TANAH YANG BERSIFAT ASAM

    Ni Made Widyasari; Retno Kawuri; I Ketut Muksin

    2015-01-01

    Telah dilakukan penelitian yang bertujuan mengetahui ketahanan Rhizobium sp. yang ditumbuhkan pada pH media pertumbuhan 7,0 dan 5,8 serta mengetahui kemampuan hidup Rhizobium sp. pada media tanah asam dengan pH 5,0 dan respon inokulum Rhizobium sp. pada tanaman kedelai secara in vivo. ATR (Acid Tolerance Responce) didapatkan dengan cara menumbuhkan Rhizobium sp. dengan pH media pertumbuhan 7,0 dan ditambahkan dengan media YMB (Yeast Extract Mannitol Broth) dengan pH 5,8 dan pH 7,0, diinkubasi...

  12. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper.

    Zheng, Xuecheng; Li, Dongwei

    2016-01-01

    This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 10(8) cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A. ferrooxidans, and organic acids could chelate or precipitate harmful heavy metals to reduce their damage on A. ferrooxidans and promote its growth. Organic acids could also damage the mineral lattice to increase the leaching effect. PMID:26942203

  13. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper

    Xuecheng Zheng

    2016-01-01

    Full Text Available This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 108 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A. ferrooxidans, and organic acids could chelate or precipitate harmful heavy metals to reduce their damage on A. ferrooxidans and promote its growth. Organic acids could also damage the mineral lattice to increase the leaching effect.

  14. Use of Two-Dimensional Polyacrylamide Electrophoresis to Demonstrate that Putative Rhizobium Cross-Inoculation Mutants Actually Are Contaminants

    Leps, Walter T.; Roberts, G P; Brill, Winston J.

    1980-01-01

    Two-dimensional polyacrylamide electrophoresis was used to determine that mutants of Rhizobium trifolii DT6, claimed to be capable of effectively nodulating soybeans, were actually Rhizobium japonicum 110 contaminants isolated from the parent DT6 culture.

  15. Molecular markers to study competition and diversity of Rhizobium.

    Sessitsch, A

    1997-01-01

    The research described in this thesis was directed to the development of molecular identification and detection techniques for studying the ecology of Rhizobium, a nitrogen- fixing bacterium of agricultural importance. Competition of inoculant strains with indigenous microbes is a serious problem in agricultural practice and was therefore addressed in this work using the developed tools. Furthermore, various molecular techniques have been applied to analyse rhizobial populations nodulating co...

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

    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. Rhizobium ipomoeae sp. nov., isolated from a water convolvulus field.

    Sheu, Shih-Yi; Chen, Zih-Han; Young, Chiu-Chung; Chen, Wen-Ming

    2016-04-01

    A bacterial strain, designated shin9-1T, was isolated from a water sample taken from a water convolvulus field in Taiwan and characterized using a polyphasic taxonomical approach. Cells of strain shin9-1T were aerobic, Gram-stain-negative, rod-shaped and surrounded by a thick capsule and formed cream-coloured colonies. Growth occurred at 10-45 °C (optimum, 30 °C), with 0-3.0 % NaCl (optimum, 0.5 %) and at pH 7.0-9.0 (optimum, pH 7.0). Strain shin9-1T did not form nodules on a legume plant, Macroptilium atropurpureum, and the nodulation genes nodA, nodC and the nitrogenase reductase gene nifH were not detected by PCR. Phylogenetic analyses based on 16S rRNA and three housekeeping gene sequences (recA, atpD and rpoB) showed that strain shin9-1T belonged to the genus Rhizobium. Strain shin9-1T had the highest level of 16S rRNA gene sequence similarity with respect to Rhizobium daejeonense L61T (97.6 %). The major fatty acid of strain shin9-1T was C18 : 1ω7c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol, phosphatidylmonomethylethanolamine and several uncharacterized lipids. The DNA G+C content was 58.3 mol%. The DNA-DNA relatedness of strain shin9-1T with respect to recognized species of the genus Rhizobium was less than 70 %. 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 phylogenetic inference and phenotypic data, strain shin9-1T should be classified as a representative of a novel species, for which the name Rhizobium ipomoeae sp. nov. is proposed. The type strain is shin9-1T ( = LMG 27163T = KCTC 32148T). PMID:26739022

  18. Rhizobium selenireducens sp. nov.: A selenite reducing a-Proteobacteria isolated from a bioreactor

    A Gram-negative, non-pigmented bacterium designated strain B1 was isolated from a laboratory bioreactor that reduced selenate to elemental red selenium (Se0). 16S rRNA gene sequence alignment identified the isolate as a Rhizobium sp. belonging to the Rhizobium clade that includes R. daejeonense, R....

  19. Draft Genome Sequence of Rhizobium sp. GHKF11, Isolated from Farmland Soil in Pecan Grove, Texas

    Damania, Ashish

    2016-01-01

    Rhizobium sp. GHKF11 is an organophosphate-degrading bacterial strain that was isolated from farmland soil in Pecan Grove, Texas, USA. In addition to a capacity for pesticide degradation, GHKF11 shares conserved traits with other Rhizobium spp., including heavy metal resistance and transport genes that may have significant agricultural biotechnology applications. PMID:27445376

  20. Effects of nano-ZnO on the agronomically relevant Rhizobium-legume symbiosis

    The impact of nano-ZnO (nZnO) on Rhizobium-legume symbiosis was studied with garden pea and its compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure of peas to nZnO had no impact on germination, but significantly affected root length. Chronic exposure of plant to nZnO impac...

  1. In Rhizobium japonicum the nitrogenase genes nifH and nifDK are separated.

    Kaluza, K.; Fuhrmann, M.; Hahn, M.; Regensburger, B; Hennecke, H

    1983-01-01

    In contrast to Klebsiella pneumoniae or fast-growing Rhizobium species, such as R. meliloti, where the nitrogenase structural genes are clustered in one operon (nifHDK), in slow-growing Rhizobium japonicum 110, nifH and nifDK are on separate operons.

  2. Mobilization of a Sym plasmid from a fast-growing cowpea Rhizobium strain.

    Morrison, N.A.; Cen, Y H; Chen, H.C.; Plazinski, J; Ridge, R; Rolfe, B G

    1984-01-01

    A large Sym plasmid from a fast-growing cowpea Rhizobium species was made mobilizable by cointegration with plasmid pSUP1011, which carries the oriT region of RP4. This mobilizable Sym plasmid was transferred to a number of Rhizobium strains, in which nodulation and nitrogen fixation functions for symbiosis with plants of the cowpea group were expressed.

  3. Contribución al estudio de los plásmidos de Rhizobium

    Cubo Sánchez, María Teresa

    1988-01-01

    En este trabajo, hemos estudiado la transferencia y expresión del plásmido simbiótico PJB5JI de Rhizobium leguminosarum biovar viceae en diversas estirpes de Rhizobium sp. y Bradyrhizobium sp. que nodulan en Cicer arietinum y en Cajanus cajan. De los resu

  4. Expression of symbiotic genes of Rhizobium japonicum USDA 191 in other rhizobia.

    Appelbaum, E R; McLoughlin, T J; O'Connell, M.; Chartrain, N

    1985-01-01

    A 200-megadalton plasmid was mobilized from Rhizobium japonicum USDA 191 to other Rhizobium strains either that cannot nodulate soybeans or that form Fix- nodules on certain cultivars. The symbiotic properties of the transconjugants indicate that both soybean specificity for nodulation and cultivar specificity for nitrogen fixation are plasmid encoded.

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

    Jensen, Erik Steen; Sørensen, Lasse Holst; Engvild, Kjeld Christensen

    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...... pattern with Rhizobium leguminosarum strains isolated from a modern pea variety cultivated in the same field....

  6. Preliminary data on some correlations of Rhizobium and radio-stimulation seed treatments

    The seeds of peas, beans, soy-beans and lucerne were treated with 60Co-irradiation (4-10 Gray). The size of the roots and the quantity of seed-crop were measured. Irradiation by itself had no significant effect. Treatment with Rhizobium bacteria and with Rhizobium plus irradiation had considerable positive effects. (L.E.)

  7. Evidence of an American Origin for Symbiosis-Related Genes in Rhizobium lusitanum ▿

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

    2011-01-01

    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

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

    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...

  9. Biochemical characterization of a fructokinase mutant of Rhizobium meliloti.

    Gardiol, A; Arias, A.; Cerveñansky, C; Gaggero, C; Martínez-Drets, G

    1980-01-01

    A double mutant strain (UR3) of Rhizobium meliloti L5-30 was isolated from a phosphoglucose isomerase mutant (UR1) on the basis of its resistance to fructose inhibition when grown on fructose-rich medium. UR3 lacked both phosphoglucose isomerase and fructokinase activity. A mutant strain (UR4) lacking only the fructokinase activity was derived from UR3; it grew on the same carbon sources as the parent strain, but not on fructose, mannitol, or sorbitol. A spontaneous revertant (UR5) of normal ...

  10. Relations between Rhizobium and radiostimulation treatments of seeds

    In field experiments the effects of irradiation with 60Co isotope the seeds of round seeded peas (Pisum sativum L.), beans (Phaseolus vulgaris L.), soybeans (Glycine max. L./Merr.) and lucerne (Medicago sativa) were investigated. Rhizobium bacteria inoculation was carried out with the inoculator ''Rhizonit''. The green mass yield was determined for lucerne and the grain yield for the other plants. Irradiation induced flowering of peas 4-5 days earlier. The bean yields increased significantly on the influence of 1000 rad irradiation plus Rhizonit inoculation. For soybeans the yield response to Rhizonit proved to be significant. (author)

  11. 75 FR 6709 - United States, et al. v. Ticketmaster Entertainment Inc. and Live Nation Inc.; Proposed Final...

    2010-02-10

    ... Antitrust Division United States, et al. v. Ticketmaster Entertainment Inc. and Live Nation Inc.; Proposed... Columbia in United States of America, et al. v. Ticketmaster Entertainment, Inc. and Live Nation, Inc... general, filed a Complaint alleging that the proposed merger of Ticketmaster Entertainment, Inc. and...

  12. PENGARUH pH MEDIA PERTUMBUHAN TERHADAP KETAHANAN DARI Rhizobium sp. PADA TANAH YANG BERSIFAT ASAM

    Ni Made Widyasari

    2015-02-01

    Full Text Available Telah dilakukan penelitian yang bertujuan mengetahui ketahanan Rhizobium sp. yang ditumbuhkan pada pH media pertumbuhan 7,0 dan 5,8 serta mengetahui kemampuan hidup Rhizobium sp. pada media tanah asam dengan pH 5,0 dan respon inokulum Rhizobium sp. pada tanaman kedelai secara in vivo. ATR (Acid Tolerance Responce didapatkan dengan cara menumbuhkan Rhizobium sp. dengan pH media pertumbuhan 7,0 dan ditambahkan dengan media YMB (Yeast Extract Mannitol Broth dengan pH 5,8 dan pH 7,0, diinkubasi pada suhu 280C selama 24 jam pada shaker. Penghitungan total mikroba dilakukan setiap 2 jam sekali dengan menggunakan platting method. Uji ketahanan Rhizobium sp. pada tanah asam dengan pH 5,0 secara in vitro dengan cara menghitung total bakteri dengan menggunakan platting method setiap hari selama 28 hari. Uji in vivo dilakukan dirumah kaca dengan menggunakan metoda MPN (Most Probable Number. Hasil penelitian menunjukkan Rhizobium sp. yang dikondisikan pertumbuhannya dengan pH 5,8 lebih resisten dan dapat membentuk ATR dibandingkan dengan Rhizobium sp. yang ditumbuhkan pada pH media 7,0. Pada pH 5,8 setelah 10 jam total bakteri 285 CFU/g sedangkan pada pH 7,0 total bakteri 148 CFU/g. Rhizobium sp. mampu hidup pada tanah asam dengan pH 5,0 dan membentuk ATR pada hari ke 6 dengan total bakteri 137 x 104 CFU/g, tetapi respon inokulum Rhizobium sp. pada tanah dengan pH 5,0 tidak terjadi pembentukan nodul pada tanaman kedelai dikarenakan tanaman kedelai mengalami defisiensi unsur hara.

  13. Uji Asosiasi Bakteri Rhizobium Terseleksi dengan Leguminosa Pakan dalam Kondisi Tercekam Salin

    Eny Fuskhah; R. Djoko Soetrisno; Syaiful Anwar; Florentina Kusmiyati

    2014-01-01

    (Test of Association Selected Rhizobium Bacteria with Legumes in Salinity Stress) ABSTRACT. The research aim was to investigate association selected rhizobium bacteria with legumes in salinity stress. Plant media was salin soil that have EC = 20.45 mmhos/cm which taken from Morosari beach, Sayung, Demak. Rhizobium isolate applied was tolerant to 12.000 ppm of NaCl that equaled to electrical conductivity of 20 mmhos/cm. The research was carried out in green house of Laboratory of Forage Sc...

  14. Suicide plasmid vehicles for insertion mutagenesis in Rhizobium meliloti and related bacteria.

    Selvaraj, G; Iyer, V. N.

    1983-01-01

    We describe the construction and use of a set of plasmid vectors of the transposons Tn1, Tn5, and Tn9 that are suicidal in Rhizobium species and therefore suitable for mutagenesis with these three transposons. The vectors are composed of the p15A replicon which functions in Escherichia coli but not in Rhizobium species and a region encoding the N type of bacterial conjugation system which is very efficient in matings between E. coli and Rhizobium species. The usefulness of the vectors has bee...

  15. Estudio de las propiedades simbióticas de las estirpes de Rhizobium Fredii

    Buendía Clavería, Ana María

    1988-01-01

    En 1982, Keyser y Col. aislaron unas bacterias de crecimiento rápido a partir de nódulos de plantas de soja. Estas nuevas estirpes se han agrupado en la nueva especie Rhizobium fredii. Nosotros hemos estudiado la transferencia y expresión de los plásmidos simbióticos p42d Y pRtr5a en la estirpe USDA 194 de Rhizobium fredii. En segundo lugar, hemos estudiado las propiedades simbióticas de diversas estirpes de Rhizobium fredii en diferentes variedades de soja y en diversas plantas del grupo Cow...

  16. [Infective endocarditis by Rhizobium radiobacter. A case report].

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

    2013-03-01

    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 report 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. PMID:23781714

  17. A rhizobium leguminosarum mutant defective in symbiotic iron acquisition

    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 symbiotically

  18. Microgravity effects on the legume/Rhizobium symbiosis

    Urban, James E.

    1997-01-01

    Symbiotic nitrogen fixation is of critical importance to world agriculture and likely will be a critical part of life support systems developed for prolonged missions in space. Bacteroid formation, an essential step in an effective Dutch White Clover/Rhizobium leguminosarum bv trifolii symbiosis, is induced by succinic acid which is produced by the plant and which is bound and incorporated by the bacterium. Aspirin mimics succinate in its role as a bacteroid inducer and measures of aspirin binding mimiced measurements of succinate binding. In normal gravity (1×g), rhizobium bacteria immediately bound relatively high levels of aspirin (or succinate) in a readily reversible manner. Within a few seconds a portion of this initially bound aspirin became irreversibly bound. In the microgravity environment aboard the NASA 930 aircraft, rhizobia did not display the initial reversible binding of succinate, but did display a similar kinetic pattern of irreversible binding, and ultimately bound 32% more succinate (Acta Astronautica 36:129-133, 1995.) In normal gravity succinate treated cells stop dividing and swell to their maximum size (twice the normal cell volume) within a time equivalent to the time required for two normal cell doublings. Swelling in microgravity was tested in FPA and BPM sample holders aboard the space shuttle (USML-1, and STS-54, 57, and 60.) The behavior of cells in the two sample holders was similar, and swelling behavior of cells in microgravity was identical to behavior in normal gravity.

  19. 78 FR 22298 - United States v. Apple, Inc., et al.; Public Comments and Response on Proposed Final Judgment

    2013-04-15

    ... (``Publisher Defendants'') conspired to raise prices of electronic books (``e-books'') in the United States in..., see United States v. Apple, Inc., et al., 77 FR 77094; and summaries of the terms of the...

  20. Response of Snap Bean Cultivars to Rhizobium Inoculation under Dryland Agriculture in Ethiopia

    Hussien Mohammed Beshir

    2015-07-01

    Full Text Available High yield in snap bean (Phaseolus vulgaris L. production requires relatively high nitrogen (N inputs. However, little information is available on whether the use of rhizobial inoculants for enhanced biological dinitrogen fixation can provide adequate N to support green pod yield. The objectives of this study were to test the use of rhizobia inoculation as an alternative N source for snap bean production under rain fed conditions, and to identify suitable cultivars and appropriate agro-ecology for high pod yield and N2 fixation in Ethiopia. The study was conducted in 2011 and 2012 during the main rainy season at three locations. The treatments were factorial combinations of three N treatments (0 and 100 kg·N·ha−1, and Rhizobium etli (HB 429 and eight snap bean cultivars. Rhizobial inoculation and applied N increased the total yield of snap bean pod by 18% and 42%, respectively. Cultivar Melkassa 1 was the most suitable for a reduced input production system due to its greatest N2 fixation and high pod yield. The greatest amount of fixed N was found at Debre Zeit location. We concluded that N2 fixation achieved through rhizobial inoculation can support the production of snap bean under rain fed conditions in Ethiopia.

  1. PoolSeq analysis of the selection of the Rhizobium genotypes by the legume host plant

    Jorrin, Beatriz; Imperial Ródenas, Juan

    2013-01-01

    Rhizobium leguminosarum establishes highly specific nitrogen-fixing symbioses. We have applied a Pool-Seq approach to study plant host selection of genotypes. Our results confirm, at the genomic level, previous observations regarding plant selection of specific genotypes

  2. Survival of Rhizobium phaseoli in Coal-Based Legume Inoculants Applied to Seeds †

    Crawford, S. L.; Berryhill, D L

    1983-01-01

    Eight coals used as carriers in legume inoculants promoted the survival of Rhizobium phaseoli on pinto bean seeds. Although peat was more protective, most coal-based inoculants provided >104 viable rhizobia per seed after 4 weeks.

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

    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

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

    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.

  5. Identification and characterization of symbiotic genes on the Rhizobium leguminosarum PRE sym-plasmid.

    Schetgens, T.M.P.

    1986-01-01

    Bacteria of the genera Rhizobium and Bradyrhizobium are unique in their quality to form nitrogen-fixing root nodules in symbiosis with leguminous plants. In fast-growing Rhizobium bacteria the genes involved in host recognition and nodule development ( nod ) and in nitrogen fixation ( nif or fix ) are located on large sym -plasmids (for recent review see e.g. Ausubel, 1984).The aim of the present investigations was to identify symbiotic genes in R.leguminosarum PRE and to study their expressi...

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

    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...

  7. The central domain of Rhizobium leguminosarum DctD functions independently to activate transcription.

    Huala, E; Stigter, J; Ausubel, F. M.

    1992-01-01

    Sigma 54-dependent transcriptional activators such as Escherichia coli NtrC, Rhizobium meliloti NifA, and Rhizobium leguminosarum DctD share similar central and carboxy-terminal domains but differ in the structure and function of their amino-terminal domains. We have deleted the amino-terminal and carboxy-terminal domains of R. leguminosarum DctD and have demonstrated that the central domain of DctD, like that of NifA, is transcriptionally competent.

  8. Exopolysaccharide-Deficient Mutants of Rhizobium fredii HH303 Which Are Symbiotically Effective

    Kim, Choong-Hyun; Tully, Raymond E.; Keister, Donald L.

    1989-01-01

    Nineteen Tn5-induced mutants of Rhizobium fredii HH303 defective in acidic exopolysaccharide synthesis were isolated by screening for lack of Calcofluor fluorescence. They were grouped by complementation analysis by using Rhizobium meliloti cosmids carrying exo genes. All of the 19 mutants were symbiotically effective or partially effective, indicating that the major bacterial acidic exopolysaccharide of this strain of R. fredii may not be required for symbiotic development in the soybean.

  9. Possible Involvement of Phage-Like Structures in Antagonism of Cowpea Rhizobia by Rhizobium trifolii

    Joseph, M. V.; Desai, J D; Desai, A J

    1985-01-01

    A reduction in the viability of cowpea rhizobia was observed when Rhizobium trifolii IARI and cowpea Rhizobium strain 3824 were inoculated together in soil. The reduction in number of cowpea rhizobia in soil was found to be associated with the reduction in number of nodules per plant and retardation in plant growth. An antimicrobial substance was isolated from R. trifolii which, on electron microscopic investigation, demonstrated the presence of several phage-like structures.

  10. Interactions of Meloidogyne incognita, Xanthomonas campestris, and Rhizobium sp. in the disease complex of chickpea

    SIDDIQUI, Zaki Anwar; FATIMA, Munavvar; ALAM, Subha

    2013-01-01

    The effects of Meloidogyne incognita, Xanthomonas campestris, and Rhizobium sp., alone or in combination, on the disease complex in chickpea were examined. Individual inoculation with M. incognita and X. campestris caused significant reductions in plant growth, while inoculation with Rhizobium sp. resulted in a significant increase in plant growth. Inoculation with M. incognita and X. campestris together caused a greater reduction in plant growth than the damage caused by each of them alone. ...

  11. Uji Asosiasi Bakteri Rhizobium Terseleksi dengan Leguminosa Pakan dalam Kondisi Tercekam Salin

    Eny Fuskhah

    2014-04-01

    Full Text Available (Test of Association Selected Rhizobium Bacteria with Legumes in Salinity Stress ABSTRACT. The research aim was to investigate association selected rhizobium bacteria with legumes in salinity stress. Plant media was salin soil that have EC = 20.45 mmhos/cm which taken from Morosari beach, Sayung, Demak. Rhizobium isolate applied was tolerant to 12.000 ppm of NaCl that equaled to electrical conductivity of 20 mmhos/cm. The research was carried out in green house of Laboratory of Forage Science Diponegoro University Semarang. The design arranged was completely randomized design with factorial design 2 x 4 in 3 repeatations. First factor was kind of legumes, T1 = lamtoro (Leucaena leucocephala; T2 = turi (Sesbania grandiflora. and second factor was kind of rhizobium isolates, I1 = without isolate; I2 = rhizobium that was isolated from lamtoro, I3 = rhizobium that was isolated from turi; I4 = combination isolate from lamtoro and turi. The crop growth was observed up to 10 weeks of age. The parameters were 1 crops heigh; 2 sum of leaf crops; 3 fresh weight production; 4 dry weight production; 5 amount and fresh weigh of effective root nodules. The study showed the growth and production of turi in saline media of EC 20.45 mmhos/cm was higher than lamtoro. Root nodule of turi was formed, but lamtoro was not. Turi was more tolerant than lamtoro at very saline media.

  12. Role of Rhizobium Inoculation in Chickpea (Cicer arietinum L.) Under Water Stress Conditions

    Rahat Parveen; Sadiq, M.; Muzammil Saleem

    1999-01-01

    Two chickpea varieties viz., 90122 and 93081 were subjected to Rhizobium inoculation with BioPower under water stress conditions, imposed by withholding water. Stress reduced all the parameters including yield components and this effect was more pronounced by stress at reproductive stage as compared with vegetative stage. Rhizobium inoculation enhanced yield under both normal and stressed conditions, but its performance was better under normal than under stress. Rhizobium inoculation proved i...

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

    Kacem, M.; Kazouz, F.; Merabet, C.; Rezki, M.; de Lajudie, Philippe; Bekki, A

    2009-01-01

    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 prot...

  14. Use of combined inoculum of Azospirillum and Rhizobium in winged bean Psophocarpus tetragonolobus (L) D.C

    Iruthayathas, EE.; Vlassak, K.

    1985-01-01

    The potential of using the free living N -fixing Azospirillum in increasing the nodulation and N2-fixation by Rhizobium in winged bean was analysed. Various strains of winged bean Rhizobium and several strains of Azospirillum were tested in combined inoculations. Substantial increases in nodulation, N2-fixation, shoot dry matter production and N gain due to the mixed inoculation were obtained in one Rhizobium strain namely KUL-BH and most of the Azospirillum strains used. The influence of Rhi...

  15. 78 FR 33437 - United States v. Apple, Inc., et al.; Public Comments and Response on Proposed Final Judgment

    2013-06-04

    ... in the United States (``Publisher Defendants'') conspired to raise prices of electronic books (``e... 25, 2013, see United States v. Apple, Inc., et al., 78 FR 12874; and summaries of the terms of the..., e.g., Original Response to Comments (Docket No. 81; 77 FR 44271); Penguin Response to...

  16. 75 FR 60820 - United States v. Adobe Systems, Inc., et al.; Proposed Final Judgment and Competitive Impact...

    2010-10-01

    ... Statement, 61 FR 28891, 28894 (W.D.Mo. May 28, 1996). The Court entered an agreed-upon Final Judgment... that case, two movie theater booking agents agreed to refrain from actively soliciting each other's... the merits of the Complaint. VIII. Standard of Review Under the APPA for Proposed Final Judgment...

  17. Carbon Metabolism Enzymes of Rhizobium tropici Cultures and Bacteroids.

    Romanov, V I; Hernández-Lucas, I; Martínez-Romero, E

    1994-07-01

    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 gluconeogenic enzymes (phosphoenolpyruvate carboxykinase, fructose-6-phosphate aldolase, and fructose bisphosphatase) were detected. In bacteroids, isolated in Percoll gradients, the levels of activity for many of the enzymes measured were similar to those of malate-grown cells, except that higher activities of glucokinase, glucose-6-phosphate dehydrogenase, and NAD-dependent phosphogluconate dehydrogenase were detected. Phosphoglucomutase and UDP glucose pyrophosphorylase showed high and constant levels under all growth conditions and in bacteroids. PMID:16349319

  18. Differences between strains of Rhizobium in sensitivity to canavanine

    Four strains of rhizobia that nodulate canavanine-synthesizing legumes and four strains that nodulate noncanavanine-synthesizing legumes were tested for sensitivity to L-canavanine. The effect of canavanine on growth depends upon the strain of Rhizobium tested rather than the canavanine synthesizing capability of the host legume. In both groups of rhizobia, some strains were inhibited in growth by canavanine. Canavanine enhancement of growth was observed in rhizobia that nodulate noncanavanine-synthesizing legumes. Canavanine was found to enhance the incorporation of 3H-uridine and 3H-L-leucine into trichloroacetic acid insoluble fractions of starved cells of two strains of rhizobia tested. This demonstrated that under certain conditions, some rhizobia can detoxify canavanine and utilize it in synthetic processes

  19. Enhanced curdlan production with nitrogen feeding during polysaccharide synthesis by Rhizobium radiobacter.

    Wang, Xiao-Yu-Zhu; Dong, Jin-Jun; Xu, Guo-Chao; Han, Rui-Zhi; Ni, Ye

    2016-10-01

    Curdlan is a secondary metabolite synthesized by Agrobacterium sp. and some other bacteria. A newly isolated exopolysaccharide-producing strain was identified to be Rhizobium radiobacter CGMCC 12099. The polysaccharide product was confirmed to be curdlan with a molecule weight of 1.4×10(5)Da, and its molecular structure was determined by HPLC and infrared spectrum. Although nitrogen source is necessary for cell reproduction, curdlan production is largely dependent on nitrogen limitation, as well as cell vitality. Here, a nitrogen feeding strategy was investigated to elevate the curdlan production by R. radiobacter. The optimal concentration and addition time of (NH4)2HPO4 were investigated. The results showed that the enhanced cell density was correlated to the amount of (NH4)2HPO4 added. Also, nitrogen addition in earlier fermentation stage was beneficial to the cell growth and curdlan production. Furthermore, continuously feeding strategy was employed by feeding (NH4)2HPO4 at a constant rate of 1.24g/h at 35(th)h of fermentation for 9h, achieving a final curdlan production of 65.27g/L, productivity of 0.544g/L/h and glucose conversion rate of 38.89%. The curdlan production was improved by 2.1 times compared with that without nitrogen addition. This study provides a feasible and cheap nitrogen feeding strategy to enhance curdlan production. PMID:27312649

  20. 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.

    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

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

    Tang, Wen-Juan; Ying ZHOU; Ye, Bang-Ce

    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.

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

    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.

  3. Estudio del plásmido simbiótico de una estirpe de Rhizobium SP (Hedysarum Coronarium)

    Ollero Márquez, Francisco Javier

    1988-01-01

    La estirpe IS 123 de Rhizobium sp. (Hedysarum coronarium) presenta un plásmido simbiótico (230 MD), que se ha marcado con el transposon IN5MOB, comprobándose que es autotransferible, si bien su transferencia a determinadas estirpes de Rhizobium y agrobact

  4. Characterization of the N2O-producing soil bacterium Rhizobium azooxidifex sp. nov.

    Behrendt, Undine; Kämpfer, Peter; Glaeser, Stefanie P; Augustin, Jürgen; Ulrich, Andreas

    2016-06-01

    In the context of studying the bacterial community involved in nitrogen transformation processes in arable soils exposed to different extents of erosion and sedimentation in a long-term experiment (CarboZALF), a strain was isolated that reduced nitrate to nitrous oxide without formation of molecular nitrogen. The presence of the functional gene nirK, encoding the respiratory copper-containing nitrite reductase, and the absence of the nitrous oxide reductase gene nosZ indicated a truncated denitrification pathway and that this bacterium may contribute significantly to the formation of the important greenhouse gas N2O. Phylogenetic analysis based on the 16S rRNA gene sequence and the housekeeping genes recA and atpD demonstrated that the investigated soil isolate belongs to the genus Rhizobium. The closest phylogenetic neighbours were the type strains of Rhizobium. subbaraonis and Rhizobium. halophytocola. The close relationship with R. subbaraonis was reflected by similarity analysis of the recA and atpD genes and their amino acid positions. DNA-DNA hybridization studies revealed genetic differences at the species level, which were substantiated by analysis of the whole-cell fatty acid profile and several distinct physiological characteristics. Based on these results, it was concluded that the soil isolate represents a novel species of the genus Rhizobium, for which the name Rhizobium azooxidifex sp. nov. (type strain Po 20/26T=DSM 100211T=LMG 28788T) is proposed. PMID:27030972

  5. NopC Is a Rhizobium-Specific Type 3 Secretion System Effector Secreted by Sinorhizobium (Ensifer) fredii HH103.

    Jiménez-Guerrero, Irene; Pérez-Montaño, Francisco; Medina, Carlos; Ollero, Francisco Javier; López-Baena, Francisco Javier

    2015-01-01

    Sinorhizobium (Ensifer) fredii HH103 is a broad host-range nitrogen-fixing bacterium able to nodulate many legumes, including soybean. In several rhizobia, root nodulation is influenced by proteins secreted through the type 3 secretion system (T3SS). This specialized secretion apparatus is a common virulence mechanism of many plant and animal pathogenic bacteria that delivers proteins, called effectors, directly into the eukaryotic host cells where they interfere with signal transduction pathways and promote infection by suppressing host defenses. In rhizobia, secreted proteins, called nodulation outer proteins (Nops), are involved in host-range determination and symbiotic efficiency. S. fredii HH103 secretes at least eight Nops through the T3SS. Interestingly, there are Rhizobium-specific Nops, such as NopC, which do not have homologues in pathogenic bacteria. In this work we studied the S. fredii HH103 nopC gene and confirmed that its expression was regulated in a flavonoid-, NodD1- and TtsI-dependent manner. Besides, in vivo bioluminescent studies indicated that the S. fredii HH103 T3SS was expressed in young soybean nodules and adenylate cyclase assays confirmed that NopC was delivered directly into soybean root cells by means of the T3SS machinery. Finally, nodulation assays showed that NopC exerted a positive effect on symbiosis with Glycine max cv. Williams 82 and Vigna unguiculata. All these results indicate that NopC can be considered a Rhizobium-specific effector secreted by S. fredii HH103. PMID:26569401

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

    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

  7. High catalase production by Rhizobium radiobacter strain 2-1.

    Nakayama, Mami; Nakajima-Kambe, Toshiaki; Katayama, Hideki; Higuchi, Kazuhiko; Kawasaki, Yoshio; Fuji, Ryujiro

    2008-12-01

    To promote the application of catalase for treating wastewater containing hydrogen peroxide, bacteria exhibiting high catalase activity were screened. A bacterium, designated strain 2-1, with high catalase activity was isolated from the wastewater of a beverage factory that uses hydrogen peroxide. Strain 2-1 was identified as Rhizobium radiobacter (formerly known as Agrobacterium tumefaciens) on the basis of both phenotypic and genotypic characterizations. Although some strains of R. radiobacter are known plant pathogens, polymerase chain reaction (PCR) analysis showed that strain 2-1 has no phytopathogenic factor. Compared with a type strain of R. radiobacter, the specific catalase activity of strain 2-1 was approximately 1000-fold. Moreover, Strain 2-1 grew faster and exhibited considerably higher catalase activity than other microorganisms that have been used for industrial catalase production. Strain 2-1 is harmless to humans and the environment and produces catalase efficiently, suggesting that strain 2-1 is a good resource for the mass production of catalase for the treatment of hydrogen peroxide-containing wastewater. PMID:19134550

  8. Studies on mutation and repair in Rhizobium japonicum

    In the presence of NTG, Rhizobium japonicum loses viability very rapidly. 50% survival is achieved within 4 mins using 50 μgm/ml. When a constant time of 30 min is maintained then a concentration of 18 μgm/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)

  9. Biologic fixation of nitrogen in irradiated rhizobium strips

    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-γ). The D37 values for the rhizobial strain SEMIA 4077 were 43 J.m-2 (UV) and 32 Gy (R-γ) 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)

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

    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.

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

    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....

  12. Yield response of fidders (berseem, shaftal, and lucerne) to rhizobium inclulation

    Investigations were carried out to know the effect of Rhizobium inoculation on the fodder yield and nitrogen fixation of berseem, shaftal and lucerne in y clay loam soil in a pot culture experiment. A basal dressing of nitrogen, phosphorus (P/sub 2/O/sub 5/) and Potash (K/sub 2/O) at 20,80,40 Kg/ha as urea, single superphosphate and potassium sulphate were applied to each pot. The results revealed that Rhizobium inoculation significantly increased the green fodder yield in four cuttings of berseem by 35 to 147 percent of shaftal by 41 to 60 percent and of lucerne by 41 to 74 percent. Shoos N-yield in four cuttings exhibited a significant increasing trend by 21 to 158 percent in berseem, 40 to 69 percent in shaftal and 41 to 78 percent in lucerne due to biological nitrogen fixation as a result of Rhizobium inoculation. (author)

  13. Herbivores alter the fitness benefits of a plant-rhizobium mutualism

    Heath, Katy D.; Lau, Jennifer A.

    2011-03-01

    Mutualisms are best understood from a community perspective, since third-party species have the potential to shift the costs and benefits in interspecific interactions. We manipulated plant genotypes, the presence of rhizobium mutualists, and the presence of a generalist herbivore and assessed the performance of all players in order to test whether antagonists might alter the fitness benefits of plant-rhizobium mutualism, and vice versa how mutualists might alter the fitness consequences of plant-herbivore antagonism. We found that plants in our experiment formed more associations with rhizobia (root nodules) in the presence of herbivores, thereby increasing the fitness benefits of mutualism for rhizobia. In contrast, the effects of rhizobia on herbivores were weak. Our data support a community-dependent view of these ecological interactions, and suggest that consideration of the aboveground herbivore community can inform ecological and evolutionary studies of legume-rhizobium interactions.

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

    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

  15. Rhizobium acidisoli sp. nov., isolated from root nodules of Phaseolus vulgaris in acid soils.

    Román-Ponce, Brenda; Jing Zhang, Yu; Soledad Vásquez-Murrieta, María; Hua Sui, Xin; Feng Chen, Wen; Carlos Alberto Padilla, Juan; Wu Guo, Xian; Lian Gao, Jun; Yan, Jun; Hong Wei, Ge; Tao Wang, En

    2016-01-01

    Two Gram-negative, aerobic, non-motile, rod-shaped bacterial strains, FH13T and FH23, representing a novel group of Rhizobium isolated from root nodules of Phaseolus vulgaris in Mexico, were studied by a polyphasic analysis. Phylogeny of 16S rRNA gene sequences revealed them to be members of the genus Rhizobium related most closely to 'Rhizobium anhuiense' CCBAU 23252 (99.7 % similarity), Rhizobium leguminosarum USDA 2370T (98.6 %), and Rhizobium sophorae CCBAU 03386T and others ( ≤ 98.3 %). In sequence analyses of the housekeeping genes recA, glnII and atpD, both strains formed a subclade distinct from all defined species of the genus Rhizobium at sequence similarities of 82.3-94.0 %, demonstrating that they represented a novel genomic species in the genus Rhizobium. Mean levels of DNA-DNA relatedness between the reference strain FH13T and the type strains of related species varied between 13.0 ± 2.0 and 52.1 ± 1.2 %. The DNA G+C content of strain FH13T was 63.5 mol% (Tm). The major cellular fatty acids were 16 : 0, 17 : 0 anteiso, 18 : 0, summed feature 2 (12 : 0 aldehyde/unknown 10.928) and summed feature 8 (18 : 1ω7c). The fatty acid 17 : 1ω5c was unique for this strain. Some phenotypic features, such as failure to utilize adonitol, l-arabinose, d-fructose and d-fucose, and ability to utilize d-galacturonic acid and itaconic acid as carbon source, could also be used to distinguish strain FH13T from the type strains of related species. Based upon these results, a novel species, Rhizobium acidisoli sp. nov., is proposed, with FH13T ( = CCBAU 101094T = HAMBI 3626T = LMG 28672T) as the type strain. PMID:26530784

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

    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

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

    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

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

    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

  19. Sobrevivência e nodulação do Rhizobium tropici em sementes de feijão tratadas com fungicidas Survival and nodulation of Rhizobium tropici on common bean seeds treated with fungicides

    Ademir Sérgio Ferreira de Araújo; Ricardo Silva Araújo

    2006-01-01

    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 ...

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

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

    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 th...

  1. Pseudo-Outbreak of Rhizobium radiobacter Infection Resulting from Laboratory Contamination of Saline Solution▿

    Pereira, Lynette A.; Chan, Douglas Su Gin; Ng, Toon Mae; Lin, Raymond; Jureen, Roland; Fisher, Dale A; Tambyah, Paul A.

    2009-01-01

    We report a pseudo-outbreak of Rhizobium radiobacter infections resulting from contamination by a saline dispenser in the microbiology laboratory. Isolates from clinical specimens had identical antimicrobial susceptibilities and electrophoretic fingerprints. The episode resolved with autoclaving of the dispenser. This demonstrates the importance of timely, thorough investigation of unusual organisms, particularly when they appear as a cluster.

  2. Genome of Rhizobium sp. UR51a, Isolated from Rice Cropped in Southern Brazilian Fields.

    de Souza, Rocheli; Sant'Anna, Fernando Hayashi; Ambrosini, Adriana; Tadra-Sfeir, Michele; Faoro, Helisson; Pedrosa, Fabio Oliveira; Souza, Emanuel Maltempi; Passaglia, Luciane M P

    2015-01-01

    Rhizobium sp. UR51a is a Gram-negative bacterium isolated from roots of rice plants, and it presents plant growth-promoting abilities. The nutrient uptake in rice plants inoculated with UR51a was satisfactory. The genome of strain UR51a is composed of 5,233,443-bp and harbors 5,079 coding sequences. PMID:25838497

  3. Genome of Rhizobium sp. UR51a, Isolated from Rice Cropped in Southern Brazilian Fields

    de Souza, Rocheli; Sant’Anna, Fernando Hayashi; Ambrosini, Adriana; Tadra-Sfeir, Michele; Faoro, Helisson; Pedrosa, Fabio Oliveira; Souza, Emanuel Maltempi; Passaglia, Luciane M. P.

    2015-01-01

    Rhizobium sp. UR51a is a Gram-negative bacterium isolated from roots of rice plants, and it presents plant growth-promoting abilities. The nutrient uptake in rice plants inoculated with UR51a was satisfactory. The genome of strain UR51a is composed of 5,233,443-bp and harbors 5,079 coding sequences.

  4. Mineral Composition of Red Clover under Rhizobium Inoculation and Lime Application in Acid Soil

    Olivera STAJKOVIĆ-SRBINOVIĆ

    2015-12-01

    Full Text Available In the present study the effects of Rhizobium inoculation and lime application on the mineral composition (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn, B of red clover (Trifolium pratense L., in very acid soil were evaluated. Inoculation with Rhizobium leguminosarum bv. trifolii significantly increased shoot dry weight (SDW of red clover plants (three times greater, as well as N, Mg, Fe, Mn and Cu contents in plants compared to the control. Application of lime and Rhizobium together, depending on the lime rate (3, 6 or 9 t ha-1 of lime and the cut, increased SDW significantly, but decreased the contents of N, P, K, Mg, Mn, Zn and B in plants. Regardless of the changes, in all treatments in both cuts, contents of N, K, Ca, Mg, Mn and Zn in plants were among sufficiency levels (Mg content was elevated in the second cut, while Fe content was mainly high, as well as Cu (in the second cut. Contents of P and B in plants were somewhat lower than sufficiency levels, but above critical level. Therefore, red clover can be grown with satisfactory yield and mineral composition in acid soil with Rhizobium inoculation only, but the application of P and B fertilization is desirable.

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

    Agarwal, Leena; Hemant J. Purohit

    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.

  6. Three cases of post-cataract surgery endophthalmitis due to Rhizobium (Agrobacterium) radiobacter.

    Moreau-Gaudry, Viviane; Chiquet, Christophe; Boisset, Sandrine; Croize, Jacques; Benito, Yvonne; Cornut, Pierre Loïc; Bron, Alain; Vandenesch, François; Maurin, Max

    2012-04-01

    We present three unrelated post-cataract surgery endophthalmitis cases caused by Rhizobium radiobacter, hospitalized in three different hospitals. Early diagnosis was obtained in two cases by bacterial DNA detection in vitreous samples. All patients recovered from infection, but pars plana vitrectomy was needed in two patients due to rapid clinical deterioration. PMID:22259203

  7. Analysis of Rhizobium meliloti Sym Mutants Obtained by Heat Treatment †

    Toro, Nicolas; Olivares, José

    1986-01-01

    Deletions in the pSym megaplasmid of Rhizobium meliloti were produced at a high frequency, and their lengths varied according to incubation temperature. Morphological differentiation into large and small colonies occurred after heat treatment. Small colonies elicited pseudonodules on alfalfa roots.

  8. Free-Living Rhizobium Strain Able to Grow on N2 as the Sole Nitrogen Source

    1983-01-01

    A Rhizobium strain isolated from stem nodules of the legume Sesbania rostrata was shown to grow on atmospheric nitrogen (N2) as the sole nitrogen source. Non-N2-fixing mutants isolated directly on agar plates formed nodules that did not fix N2 when inoculated into the host plant.

  9. Reduction of Selenite to Elemental Red Selenium by Rhizobium sp. strain B1

    bacterium that reduces the soluble and toxic selenite anion to insoluble elemental red selenium (Se0) was isolated from a laboratory bioreactor. Biochemical, morphological, and 16S rRNA gene sequence alignment identify the isolate as a Rhizobium sp. that is related to but is genetically divergent ...

  10. Estudio genético de la nodulación de "Rhizobium fredii"

    Romero Portillo, Francisco

    1993-01-01

    En esta tesis se han estudiado diversos aspectos de la nodulación de las estirpes de Rhizobium fredii. Esta especie está constituida por diferentes estirpes que se caracterizan por ser de crecimiento rápido (2 a 4 horas de tiempo de generación) y por nodu

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

    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...

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

    Jensen, Erik Steen; Sørensen, Lasse Holst; Engvild, Kjeld Christensen

    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...

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

    Chovanec, Pavel; Novák, Karel

    2005-01-01

    Roč. 50, č. 4 (2005), s. 323-331. ISSN 0015-5632 R&D Projects: GA ČR 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

  14. YIELD RESPONSE OF VALENCIA PEANUT WITH DIFFERENT ROW ORIENTATIONS, NITROGEN RATES AND RHIZOBIUM INOCULUM

    Peanut grown in the southeast with twin row orientation has shown an increase in yield and grade over conventional single row. Peanut farmers in New Mexico do not use rhizobium inoculum at the time of planting, but do apply high rates of nitrogen fertilizer (300 to 350 kg ha-1). A study was conduct...

  15. Rhizobium selenireducens sp. nov. Validation and inclusion onto the list of organisms with standing in nomenclature.

    This is a submission to the list of microorganisms with standing in nomenclature. The list of valid microbial names is maintained by the International Journal of Systematic and Evolutionary Microbiology and we are proposing that Rhizobium selenireducens sp. nov. be added to the list as a valid spec...

  16. Response of Andean and Mesoamerican common bean genotypes to inoculation with rhizobium strains.

    In most common bean (Phaseolus vulgaris L.) production regions of Latin America, inoculants are rarely used by farmers in spite of several studies that demonstrate the importance of Rhizobium inoculation on commercial production of legume crops. This study investigated specific bean host plant-Rhizo...

  17. Rhizobium marinum sp. nov., a malachite-green-tolerant bacterium isolated from seawater.

    Liu, Yang; Wang, Run-Ping; Ren, Chong; Lai, Qi-Liang; Zeng, Run-Ying

    2015-12-01

    A motile, Gram-stain-negative, non-pigmented bacterial strain, designated MGL06T, was isolated from seawater of the South China Sea on selection medium containing 0.1 % (w/v) malachite green. Strain MGL06T showed highest 16S rRNA gene sequence similarity to Rhizobium vignae CCBAU 05176T (97.2 %), and shared 93.2-96.9 % with the type strains of other recognized Rhizobium species. Phylogenetic analyses based on 16S rRNA and housekeeping gene sequences showed that strain MGL06T belonged to the genus Rhizobium. Mean levels of DNA-DNA relatedness between strain MGL06T and R. vignae CCBAU 05176T, Rhizobium huautlense S02T and Rhizobium alkalisoli CCBAU 01393T were 20 ± 3, 18 ± 2 and 14 ± 3 %, respectively, indicating that strain MGL06T was distinct from them genetically. Strain MGL06T did not form nodules on three different legumes, and the nodD and nifH genes were also not detected by PCR or based on the draft genome sequence. Strain MGL06T contained Q-10 as the predominant ubiquinone. The major fatty acid was C18 : 1ω7c/C18 : 1ω6c with minor amounts of C19 : 0 cyclo ω8c, C16 : 0 and C18 : 1ω7c 11-methyl. Polar lipids of strain MGL06T included unknown glycolipids, phosphatidylcholine, aminolipid, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, an unknown polar lipid and aminophospholipid. Based on its phenotypic and genotypic data, strain MGL06T represents a novel species of the genus Rhizobium, for which the name Rhizobium marinum sp. nov. is proposed. The type strain is MGL06T ( = MCCC 1A00836T = JCM 30155T). PMID:26374202

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

    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.

  19. Potensi Rhizobium dan Pupuk Nitrogen Untuk Meningkatkan Pertumbuhan dan Produksi Kedelai (Glycine max L) Pada Lahan Bekas Sawah

    Mayani, Nanda

    2012-01-01

    Nanda Mayani, 2012. "Potential Rhizobium and Nitrogen Fertilizer to Growth and Soybean Production (Glycine max L.) on the Former Rice Field". The research aims to determine the potential of Rhizobium on the former rice field to increase growth and soybean production. The research was conducted on the former rice field at Meunasah Alue Muara Dua Lhokseumawe, NAD province, from March until July 2011. The research method used was Randomized Block Design factorial pattern of two factors and th...

  20. Asymbiotic Acetylene Reduction by a Fast-Growing Cowpea Rhizobium Strain with Nitrogenase Structural Genes Located on a Symbiotic Plasmid

    Bender, Gregory L.; Plazinski, Jacek; Rolfe, Barry G.

    1986-01-01

    A procedure was designed which enabled the detection of ex planta nitrogenase activity in the fast-growing cowpea Rhizobium strain IHP100. Nitrogenase activity in agar culture under air occurred at a rate similar to that found for Bradyrhizobium strain CB756 but lower than that for Rhizobium strain ORS571. Hybridization studies showed that both nod and nif genes were located on a 410-kilobase Sym plasmid in strain IHP100.

  1. Complete Genome Sequence of the Sesbania Symbiont and Rice Growth-Promoting Endophyte Rhizobium sp. Strain IRBG74

    Crook, Matthew B.; Mitra, Shubhajit; Ané, Jean-Michel; Sadowsky, Michael J.; Gyaneshwar, Prasad

    2013-01-01

    Rhizobium sp. strain IRBG74 is the first known nitrogen-fixing symbiont in the Agrobacterium/Rhizobium clade that nodulates the aquatic legume Sesbania sp. and is also a growth-promoting endophyte of wetland rice. Here, we present the sequence of the IRBG74 genome, which is composed of a circular chromosome, a linear chromosome, and a symbiotic plasmid, pIRBG74a.

  2. Inoculação com Rhizobium e aplicação de nitrogênio em amendoim Comparison among Rhizobium strains inoculations and nitrogen applications on peanut, in field conditions

    Antonio Roberto Giardini

    1985-01-01

    Full Text Available Existe, nas nossas condições, uma população autóctone de Rhizobium capaz de nodular o amendoim (Arachis hypogaea L., mas pouco se sabe da contribuição do nitrogênio fixado para esta planta. Foram conduzidos dois ensaios no campo, em solo de baixa fertilidade, um no período "da seca" e outro no "das águas", comparando o crescimento e a produção de plantas de amendoim inoculado com Rhizobium selecionado, com o de plantas noduladas pela população autóctone, adubadas ou não com nitrogênio. A nodulação das plantas inoculadas foi semelhante à observada nos tratamentos não inoculados, com ou sem nitrogênio. Na fase final do ciclo das plantas, houve maior acúmulo e maior taxa de absorção diária de nitrogênio nos tratamentos inoculados ou com adubação nitrogenada, do que no controle sem inoculação e sem nitrogênio. No ensaio da seca, não houve aumento de produção devido à adubação nitrogenada, ou à inoculação. No ensaio das águas, houve resposta à aplicação de nitrogênio no plantio. Os resultados de produção não foram coerentes com os da marcha de absorção de N. A produção de ensaio das águas foi equivalente a 3.400 kg/ha para o tratamento sem nitrogênio e sem inoculação.Two field experiments were carried out with peanut in the same area on a limed and fertilized "cerrado soil" (originally acidic and low fertility. The first experiment was carried out in the autumn/winter (dry season, and the second one in the subsequent spring/summer (wet season, in Campinas, State of São Paulo, Brazil. Plant development and production of inoculated (three Rhizobium strains and nitrogen fertilized treatments (at planting 25 and 45 days after planting were compared with non-inoculated and non-N-fertilized control. Nodulation of inoculated plants was similar to those of non-inoculated, with or without nitrogen. Greater accumulations, and rates for average daily uptake of nitrogen were observed for inoculated as

  3. Rhizobium promotes non-legumes growth and quality in several production steps: towards a biofertilization of edible raw vegetables healthy for humans.

    Paula García-Fraile

    Full Text Available 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 promoting their growth in different production stages increasing yield and quality of seedlings and fruits. Our results confirmed those obtained in cereals and alimentary oil producing plants extending the number of non-legumes susceptible to be biofertilized with rhizobia to those whose fruits are raw consumed. This is a relevant conclusion since safety of rhizobia for human health has been demonstrated after several decades of legume inoculation ensuring that they are optimal bacteria for biofertilization.

  4. 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.

    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)

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

    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.

  6. Isolation and properties of an ultraviolet-sensitive mutant of Rhizobium trifolii

    In an attempt to isolate a strain of Rhizobium trifolii which could be highly mutated by ultraviolet light (u.v.), a u.v.-sensitive mutant was isolated using a semi-selective procedure. The mutant was not only 85 times more sensitive than the wild-type to the lethal effects of u.v., but was mutated at u.v. doses which had little mutagenic effect on the wild-type. Its sensitivity to the mutagenic agents methyl methanesulphonate and gamma rays was unaltered, but its spontaneous mutation frequencies for two antibiotic resistances were increased. The mutation conferring u.v. sensitivity was mapped on the chromosome of Rhizobium leguminosarum 300 in a position between the markers ser-2 and ade-88. Unsuccessful attempts were made to transfer into the u.v.-sensitive mutant any one of a number of plasmids known to decrease the lethality of u.v. and enhance its mutagenicity. (author)

  7. Nitrogen fixation by Rhizobium leguminosarum PRE; a genetical and biochemical approach.

    Klein Lankhorst, R.

    1989-01-01

    Nitrogen fix ation by Rhizobium and Bradyrhizobium bacteria in symbiosis with their leguminous host plants forms an attractive alternative for the industrial production of nitrogenous fertilizers, both from an economic as well as an enviromnental point of view, and is the topic of many scientific research programs nowadays. Ultimate goals in many of these programs are improving the efficiency of nitrogen fix ation, the extension of the host range of the bacteria to important, non-leguminous c...

  8. Efficacy of micronutrients in influencing growth behavior of Rhizobium of Pigeonpea (Cajanus cajan L. [Millsp.])

    Sonam Paliya; A.N. Tikle; Tessy Thomas

    2014-01-01

    he present investigation was conducted to observe the effect of various concentrations (0.1 to 1.5 gm/100ml) of micronutrients (Zn, Mn, B, Cu, Mo, Fe) with yeast extract mannitol media on agriculturally important Rhizobium species isolated from root nodules of Cajanus cajan and to determine the effect of multi-micronutrient yeast extract mannitol media prepared of maximum growth concentrations of micronutrients on rhizobial growth. Concentrati...

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

    Elsayed B. Belal

    2013-01-01

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

  10. Effect of Light and Organic Acids on Oxygen Uptake by BTAi 1, a Photosynthetic Rhizobium

    Wettlaufer, S. H.; Hardy, R. W. F.

    1992-01-01

    A photosynthetic rhizobium, strain BTAi 1, was cultured ex planta to investigate its photosynthetic-respiratory system and the response of this interactive system to light quantity and quality and to the addition of organic acids. Oxygen uptake, as measured with an oxygen electrode, is diminished upon illumination, with the amount of decrease related to light intensity. This oxygen-sparing effect is correlated with the wavelengths of light that are associated with bacteriochlorophyll absorban...

  11. Conjugal transfer of the symbiotic plasmid in Rhizobium galegae sv. officinalis

    Zhen, Zeng

    2014-01-01

    Rhizobia are agriculturally important bacteria that possess the ability to fix nitrogen for their host legumes, an attribute ascribed to the presence of symbiosis-related genes usually clustered on plasmids called symbiotic plasmids (pSyms). Many pSyms have been proven self-transmissible, capable of transferring themselves to other bacteria through conjugation, thereby propagating their symbiotic features. Rhizobium galegae symbiovar (sv.) officinalis has a pSym, on which typical conjugation ...

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

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

    2015-01-01

    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 (YM...

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

    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 man...

  14. Effect of salt stress and phosphorus deficiency in mutants of rhizobium obtained by gamma irradiation

    Two strains of Rhizobium: Rhizobium Tropici and Mesorhizobium Ciceri nodulating respectively common bean and chickpea were treated by gamma irradiation (60Co) source. Radiosensibility analysis showed that 800 Gy was the biggest dose supported by these two strains. We isolated gamma irradiated resistant strain in order to select mutant of them which can supported salt stress and phosphorus deficiency. Salinity analysis showed that Mesorhizobium Ciceri 835 strain, can tolerate up to 18g/l (273 mM NaCl) of salt, whereas, their irradiation mutants tolerate salinity up to 33g/l (564mM. NaCl) Rhizobium Tropici CIAT899 can survive at 20g/l (342 mM) either for control strain or mutants. Analysis of phosphorus deficiency showed that either Rhizobium Tropici CIAT899, or Mesorhizobium Ciceri 835 can survive in medium without phosphore. Our results permit us to screen mutants tolerant to these stresses wide spread in Mediterranean soil. In this study, we choose two mutants strains irradiated by 700Gy and two mutants irradiated by 800Gy in each species, these mutants were characterized by their best growth compared with their reference strains. Our results showed that Gamma irradiation modified antibiotic resistance, such as kanamicyne, tetracycline, vancomicyne, streptomicyne, penicilline, either at 700Gy or at 800Gy, we obtained significant modification of response and persistence of penicilline resistance. Biochemical analysis showed that these strains had a variable superoxide dismutase (SOD, E.C. 1.15.1.1) and catalase (CAT, E.C. 1.11.1.6) activities essentially in Mesorhizobium Ciceri 835 mutant strains, these two enzymatic antioxidants was suggested to play an important role in environmental stress tolerance. (author)

  15. Influence of Azospirillum Strains on the Nodulation of Clovers by Rhizobium Strains

    Plazinski, Jacek; Rolfe, Barry G.

    1985-01-01

    Mixed cultures of several Azospirillum and Rhizobium trifolii strains caused either an inhibition or stimulation of nodule formation on plant hosts as compared with nodulation of plants inoculated with R. trifolii alone. Azospirillum strains affected the nodulation process at a precise cell ratio (R. trifolii/Azospirillum cells) and time of inoculation. All Azospirillum strains used showed a variation in their ability to inhibit or enhance nodulation by R. trifolii strains. When nonviable cel...

  16. Role of Dual Inoculation of Rhizobium and Arbuscular Mycorrhizal (AM Fungi on Pulse Crops Production

    Erneste HAVUGIMANA

    2016-01-01

    Full Text Available Legume crops are useful as human and animal feed, wood energy, and as soil-improving components of agricultural and agro forestry systems through its association with bio-fertilizers. The later have a potential environment friendly inputs that are supplemented for proper plant growth. Bio-fertilizers are preparations containing living cells of microorganisms that help crop plants in the uptake of nutrients by their interactions in the rhizosphere. Arbuscular mycorrhizal (AM fungi are beneficial symbionts for plant growth. They are associated with higher plants by a symbiotic association and benefit plants in the uptake of phosphorus nutrients, production of growth hormones, increase of proteins, lipids and sugars levels, helps in heavy metal binding, salinity tolerance and disease resistance. In nature symbiotic association of Rhizobium and leguminous plants fixes atmospheric nitrogen. Indeed, research has proved that the association of mycorrhizae fungi and Rhizobium, with pulse crops, increased the beneficial aspects comparatively more than their single associations with the host plants. This review focuses on the role of dual inoculation of AM fungi and Rhizobium on different pulse crops.

  17. NPR1 protein regulates pathogenic and symbiotic interactions between Rhizobium and legumes and non-legumes.

    Smadar Peleg-Grossman

    Full Text Available BACKGROUND: Legumes are unique in their ability to establish symbiotic interaction with rhizobacteria from Rhizobium genus, which provide them with available nitrogen. Nodulation factors (NFs produced by Rhizobium initiate legume root hair deformation and curling that entrap the bacteria, and allow it to grow inside the plant. In contrast, legumes and non-legumes activate defense responses when inoculated with pathogenic bacteria. One major defense pathway is mediated by salicylic acid (SA. SA is sensed and transduced to downstream defense components by a redox-regulated protein called NPR1. METHODOLOGY/PRINCIPAL FINDINGS: We used Arabidopsis mutants in SA defense pathway to test the role of NPR1 in symbiotic interactions. Inoculation of Sinorhizobium meliloti or purified NF on Medicago truncatula or nim1/npr1 A. thaliana mutants induced root hair deformation and transcription of early and late nodulins. Application of S. meliloti or NF on M. truncatula or A. thaliana roots also induced a strong oxidative burst that lasted much longer than in plants inoculated with pathogenic or mutualistic bacteria. Transient overexpression of NPR1 in M. truncatula suppressed root hair curling, while inhibition of NPR1 expression by RNAi accelerated curling. CONCLUSIONS/SIGNIFICANCE: We show that, while NPR1 has a positive effect on pathogen resistance, it has a negative effect on symbiotic interactions, by inhibiting root hair deformation and nodulin expression. Our results also show that basic plant responses to Rhizobium inoculation are conserved in legumes and non-legumes.

  18. Comparative effectiveness of different Rhizobium sp. for improving growth and yield of maize (Zea mays L.

    Ijaz Mehboob, Zahir Ahmad Zahir, Muhammad Arshad, Muhammad Khalid

    2012-05-01

    Full Text Available During the last couple of decades, it has been demonstrated that rhizobia can associate with roots of non-legumes also without forming true nodules, and can promote their growth by using one or more of the direct or indirect mechanisms of actions. This work examines the growth and yield responses of maize to inoculation with different species of rhizobia, isolated from the root nodules of chickpea (Cicer arietinum L., lentil (Lens culinaris M. and mung bean (Vigna radiata L. in pots and fields. Twenty isolates of rhizobia were isolated from root nodules each of mung bean, lentil and chickpea and were screened under axenic conditions. On the basis of their promising performance under axenic conditions, nine most efficient isolates (three from each legume host were selected, characterized and further evaluated for their growth promoting activities by conducting pot and field experiments. Results of pot experiment revealed that maximum increase in grain yield, 1000 grain weight, N, P and K uptake (up to 47.89, 54.52, 73.46, 84.66 and 59.19% by CRI28, respectively, over un-inoculated control was produced by the isolate of Mesorhizobium ciceri. Whereas, maximum improvement in rest of the parameters was caused by the isolates of Rhizobium phaseoli (i.e. fresh biomass, straw yield and root length up to 36.30% by A18, 25.46% by S6 and 81.89% by A18, respectively over un-inoculated control. Rhizobium leguminosarum isolates came out to be the least effective among the species tested. Similarly, all the selected isolates improved the growth and yield attributing parameters in fields as well but with varying capacity compared with un-inoculated control. The selected isolates of Mesorhizobium ciceri and Rhizobium phaseoli again remained superior compared to the isolates of Rhizobium leguminosarum under field conditions. The results of this study imply that rhizobium species had potential to promote growth and yield of maize but this technology should be

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

    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)

  20. The role of vesicular-arbuscular mycorrhiza in N2-fixed by legume-Rhizobium systems in phosphate-fixing agricultural soils

    The scarcity of available phosphate in many soils is a critical limiting factor in legume-Rhizobium-systems because it affects not only plant growth but nodulation and N2-fixation by the micro-symbiont. Hence, VA mycorrhizas, which are widespread in legumes, play an important role in the development of such crops and are thus of great interest for food production in the biosphere. This paper discusses the work developed in this laboratory in relation to the significance of VA mycorrhiza in N2-fixation within two legume-Rhizobium-systems: Medicago sativa (alfalfa)-Rhizobium meliloti and Hedysarum coronarium (sulla)-Rhizobium sp.. Several experiments have been carried out to study the interactions between natural and introduced VA endophytes and Rhizobium, and soluble phosphate fertilizer on growth, nodulation and N-uptake of the two test legumes in natural (unsterilized) agricultural soils. The tests were conducted under both pot and field conditions. (author)

  1. Effect of Rhizobium inoculation on some characters of a high protein mutant and its parent field bean Vicia faba L

    M1011 is a high protein mutant originally selected from the Egyptian bean (Vicia faba L.) variety Giza2 (G2) after seven generations of treating seeds with 4kR of 60Co gamma rays. Both the mutant line M1011 and its parent variety G2 were planted in soil inoculated with Rhizobium phaseoli after being sterilized. The plant and yield characters of both were then investigated. Results showed that the mean values of plant height, total and fertile number of branches per plant, number of pods per plant, seed yield and seed protein content increased significantly in both M1011 and G2 due to pre-sowing Rhizobium inoculation. Significant earliness in flowering and an increase in the number of seeds per pod were also noticed in M1011 after Rhizobium treatment. Therefore, the mutant line showed higher efficiency in utilizing bacterially fixed nitrogen than its parent mother variety Giza2. (author)

  2. Influence of a carbamate pesticide on growth, respiration (14C)-carbon metabolism and symbiosis of a Rhizobium sp

    Addition of aldicarb (2 methyl-2(methyl thio) propionaldehyde-O-methyl carbamoyl oxime) in the growth medium enhanced the growth of Rhizobium sp. (cowpea group) at 2ppm level while an inhibition was observed at the normal (5 ppm) and higher (10 ppm) concentrations. Respiration of the cells was also inhibited by 5 and 10 ppm levels of the chemical eventhough a stimulation was observed at 2 ppm (lower) concentration. The insecticide, when incorporated at 5 and 10 ppm levels in the medium increased the 14C-glucose incorporation and considerably altered the assimilation of the radioactive carbon in different fractions of rhizobium cells. Soil application of this insecticide (Temik 10 G) reduced the number of nodules formed and the total nitrogen content in cowpea plants inoculated with the Rhizobium sp. but enhanced the dry matter production of cowpea plants. (Auth.)

  3. Interactions route-tram : Analyse du risque et des difficultés perçues entre conducteurs de tramways et autres usagers de la voirie. Rapport final

    PARAN, Françoise; Delhomme, Patricia; CASTANIER, Carole

    2011-01-01

    L'objectif de ce projet est d'examiner, en France, les interactions entre les usagers de la voirie et le tramway tant du point de vue des traminots (étude 1) que des usagers (étude 2) afin de faire des recommandations pour améliorer la sécurité. Une première étude par entretiens semi-directifs a été menée auprès de 30 traminots de 10 agglomérations. Il s'est agi d'explorer les difficultés qu'ils rencontrent en conduisant le tram, les stratégies qu'ils mettent en oeuvre et les suggestions pour...

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

    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, δN-15% was determined in the following parts of the bean plants: nodules, roots, shoots, cotyledons and pods. (author)

  5. Effects of Heavy Metal from Polluted Soils on the Rhizobium Diversity

    Vasilica STAN

    2011-05-01

    Full Text Available Heavy metals adversely influence microorganisms, affecting their growth, abundance, genetic diversity, nodulation ability and efficacy. The aim of this study was to isolate and characterize free-leaving Rhizobium from soil which were artificially polluted with Cu (100, 250, and 500 mg kg-1 soil, Zn (300, 700, and 1500 mg kg-1 soil and Pb (50, 250, and 1000 mg kg-1 soil, but also with a mixture of all these metals, and cultivated with red clover (Trifolium pratense L., and to compare them with bacteria isolated from similar type of soil, but unpolluted. Rhizobia from soil were isolated on YMA medium with or without bromothymol blue (0.00125% as a pH-change indicator and the morpho-physiological characteristics of the colonies were examined. The number of Rhizobium was estimated using the most probable number method. Compared to the control, a decrease of rhizobia number and an increase of the metal concentration were observed. Several decameric primers (Operon Technology type were used and a reduced polymorphism among isolated bacteria was observed. Moreover, significant differences were observed among these strains and the collection strains used as reference. Also, when primers nodCF/nodCI for detection of nod genes were used, several amplicons were obtained, different from the results obtained with similar strains isolated from unpolluted soil. These results suggest that the survival „price” of the Rhizobium in such polluted area was the alteration of some genes, including those involved in symbiosis and, probably, in nitrogen fixation.

  6. Colloque final du programme de recherche ECHIBIOTEB : Outils innovants d’échantillonnage, d’analyses chimiques et biologiques pour le suivi de traitements avancés des eaux usées et des boues

    Miege, C.; Choubert, J.M.; Geffard, O.; Coquery, M.; Bruchet, A.; Besnault, S.; H. Budzinski; Cachot, J.; Parlanti, E; Ait Aissa, S.; Pandard, P.; Levi, Y; Dudal, Y.

    2015-01-01

    / Résumé du programme ECHIBIOTEB : Bien que les stations de traitement des eaux usées (STEU) ne soient pas construites dans le but d’éliminer les micropolluants organiques et métalliques, ces derniers peuvent néanmoins être éliminés de la phase dissoute des eaux usées par les procédés de traitement biologique conventionnels. L’élimination peut se faire grâce aux mécanismes d’adsorption sur les boues ou de dégradation biologique ou abiotique. Cependant, certains micropolluant...

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

    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...

  8. Environmental Factors Influencing Numbers of Rhizobium leguminosarum biovar trifolii and Its Bacteriophages in Two Field Soils

    Lawson, Kerrie A.; Barnet, Yvonne M.; McGilchrist, Clyde A.

    1987-01-01

    Fluctuations in numbers of Rhizobium leguminosarum biovar trifolii and its bacteriophages in two fields with different soil types were followed during a 17-month period in 1981 and 1982. Mean levels of both phage and rhizobia varied significantly (P < 0.05) on different occasions, with rhizobial levels varying from 1.6 × 102 to 2.0 × 104 cell per g of soil and phage from 0 to 1.7 × 104 PFU/g of soil. Multivariate regression analysis showed rhizobial levels to be significantly and positively r...

  9. Enzymatic Tailoring of Ornithine in the Biosynthesis of the Rhizobium Cyclic Trihydroxamate Siderophore Vicibactin

    Heemstra, John R.; Walsh, Christopher T.; Sattely, Elizabeth S.

    2009-01-01

    To acquire iron, the N2-fixing, symbiotic bacterium Rhizobium sp. produce the cyclic tri-hydroxamate siderophore vicibactin, containing a 30-membered tri-lactone scaffold. Herein we report the overproduction and purification of the six proteins VbsACGOLS in the bacterial host Escherichia coli and the reconstitution of the biosynthesis of vicibactin from primary metabolites. The flavoprotein VbsO acts as a pathway-initiating L-ornithine N5-hydroxylase, followed by VbsA which transfers (R)-3-hy...

  10. Competition Among Rhizobium leguminosarum Strains for Nodulation of Lentils (Lens esculenta)

    May, Sheila N.; Bohlool, B. Ben

    1983-01-01

    Thirty-one cultures of Rhizobium leguminosarum were screened for effectiveness (C2H2 reduction) on lentils (Lens esculenta). Fluorescent antibodies prepared against three of the most effective strains (Hawaii 5-0, Nitragin 92A3, and Nitragin 128A12) exhibited a high degree of strain specificity; the antibodies reacted strongly with their homologous rhizobia in culture and with bacteroids in nodules. They did not cross-react with one another, and only weakly with 5 of the 47 other R. leguminos...

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

    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.

  12. Effects of microgravity on the binding of acetylsalicylic acid by Rhizobium leguminosarum bv. trifolii

    Urban, James E.; Gerren, Richard; Zoelle, Jeffery

    1995-07-01

    Bacteroids can be induced in vitro by treating growing Rhizobium leguminosarum bv. trifolii with succinic acid or succinic acid structural analogs like acetylsalicylic acid. Quantitating bacteroid induction by measuring acetylsalicylic binding under normal (1 g) conditions showed two forms of binding to occur. In one form of binding cells immediately bound comparatively high levels of acetylsalicylic acid, but the binding was quickly reversed. The second form of binding increased with time by first-order kinetics, and reached saturation in 40 s. Similar experiments performed in the microgravity environment aboard the NASA 930 aircraft showed only one form of binding and total acetylsalicylic acid bound was 32% higher than at 1 g.

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

    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)

  14. Mutagenesis in pea (Pisum sativum L.) as a tool for studying plant Rhizobium symbiosis

    Pea mutants for symbiotic characteristics were obtained by treating seeds with ethylmethanesulphonate. They consisted of 15 mutants with no nodules (nod-), 10 mutants with inefficient nodules (nod+fix-) and four hypernodulating mutants (nod++nts) that also express a nitrate tolerant character of nodulation and fixation; 6, 7 and 1 loci, respectively, were identified. Strain specificity was found between a (nod+fix-) mutant and two Rhizobium leguminosarum strains. These isogenic mutants were also used in an agronomic study of nitrogen nutrition and in a cytological study to determine the stage at which abortion of symbiosis occurs. (author). 16 refs

  15. Fertilisation de la courge de plein champ : test de différentes doses et de 2 types d'engrais - rapport final 2005

    Védie, Hélène

    2006-01-01

    La fertilisation en maraîchage biologique est sans aucun doute encore un vaste domaine à explorer. Le manque de références sur les besoins des cultures d’une part, et sur les possibilités de fournitures du sol par minéralisation d’autre part, amène bien souvent les producteurs à « naviguer à vue » en utilisant des doses standards, qui ne reposent pas sur des bases agronomiques éprouvées. Les suivis réalisés par le GRAB sur aubergine en 2003 et melon en 2004 montrent qu’il est possible de d...

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

    Araújo Ademir Sérgio Ferreira; Araújo Ricardo Silva

    2006-01-01

    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 ...

  17. Crystallization and preliminary X-ray diffraction studies of maleylacetate reductase from Rhizobium sp. strain MTP-10005

    FUJII, Tomomi; Goda, Yuko; Yoshida, Masahiro; Oikawa, Tadao; Hata, Yasuo

    2008-01-01

    Maleylacetate reductase from Rhizobium sp. strain MTP-10005 has been crystallized using the sitting-drop vapour-diffusion method and microseeding. The crystals contained one dimeric molecule per asymmetric unit and diffracted to 1.79 Å resolution.

  18. Studying Plant-Rhizobium Mutualism in the Biology Classroom: Connecting the Big Ideas in Biology through Inquiry

    Suwa, Tomomi; Williamson, Brad

    2014-01-01

    We present a guided-inquiry biology lesson, using the plant-rhizobium symbiosis as a model system. This system provides a rich environment for developing connections between the big ideas in biology as outlined in the College Board's new AP Biology Curriculum. Students gain experience with the practice of scientific investigation, from…

  19. Population genomics of the symbiotic plasmids of sympatric nitrogen-fixing Rhizobium species associated with Phaseolus vulgaris.

    Pérez Carrascal, Olga M; VanInsberghe, David; Juárez, Soledad; Polz, Martin F; Vinuesa, Pablo; González, Víctor

    2016-09-01

    Cultivated common beans are the primary protein source for millions of people around the world who subsist on low-input agriculture, enabled by the symbiotic N2 -fixation these legumes perform in association with rhizobia. Within a single agricultural plot, multiple Rhizobium species can nodulate bean roots, but it is unclear how genetically isolated these species remain in sympatry. To better understand this issue, we sequenced and compared the genomes of 33 strains isolated from the rhizosphere and root nodules of a particular bean variety grown in the same agricultural plot. We found that the Rhizobium species we observed coexist with low genetic recombination across their core genomes. Accessory plasmids thought to be necessary for the saprophytic lifestyle in soil show similar levels of genetic isolation, but with higher rates of recombination than the chromosomes. However, the symbiotic plasmids are extremely similar, with high rates of recombination and do not appear to have co-evolved with the chromosome or accessory plasmids. Therefore, while Rhizobium species are genetically isolated units within the microbial community, a common symbiotic plasmid allows all Rhizobium species to engage in symbiosis with the same host in a single agricultural plot. PMID:27312778

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

    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.

  1. Performance of fenugreek bioinoculated with Rhizobium meliloti strains under semi-arid condition.

    Singh, N K; Patel, D B

    2016-01-01

    Rhizobium meliloti strains were isolated from the fields of S.D. Agricultural University (Gujarat, India) and were maintained in the Congo Red Yeast Extract Mannitol Agar medium. These strains were tested for their effectiveness for fenugreek crop grown under semi-arid condition. Among the six Rhizobium strains, FRS-7 strain showed best plant growth parameters like shoot length, shoot dry weight, shoot total nitrogen, root length, root dry weight, root total nitrogen, seed yield, 1000 grain weight, number of root nodules, and nodules fresh and dry weight. The performance of this strain was better as compared to 20 kgN ha(-1) treatment through urea and was even far better over control plot. Seed yields obtained with FRS-7 during two years were 10.14 and 9.66 q ha(-1); which was about 36.8% and 45.9% high over control. This strain resulted in saving of about 20 kgN ha(-1) accompanied with better crop yield and soil health. Results of the present experiments can be utilized in integrated nutrient management for cultivation of fenugreek in semi-arid areas to provide sustainability to agricultural productivity in such regions. PMID:26930857

  2. Extended region of nodulation genes in Rhizobium meliloti 1021. I. Phenotypes of Tn5 insertion mutants

    Rhizobium meliloti Nod- mutant WL131, a derivative of wild-type strain 102F51, was complemented by a clone bank of wild-type R. meliloti 1021 DNA, and clone pRmJT5 was recovered. Transfer of pRmJT5 conferred alfalfa nodulation on other Rhizobium species, indicating a role in host range determination for pRmJT5. Mutagenesis of pRmJT5 revealed several segments in which transposon insertion causes delay in nodulation, and/or marked reduction of the number of nodules formed on host alfalfa plants. The set of mutants indicated five regions in which nod genes are located; one mutant, nod-216, is located in a region not previously reported to encode a nodulation gene. Other mutant phenotypes correlated with the positions of open reading frames for nodH, nodF and nodE, and with a 2.2-kb EcoRI fragment. A mutant in nodG had no altered phenotype in this strain. One nodulation mutant was shown to be a large deletion of the common nod gene region. The authors present a discussion comparing the various studies made on this extended nod gene region

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

    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)

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

    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

  5. 75 FR 62858 - United States, et al.

    2010-10-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Antitrust Division United States, et al. v. American Express Company, et al.; Proposed Final Judgment and... of America, et al. v. American Express Company, et al., Civil Action No. CV-10-4496. On October...

  6. 76 FR 38700 - United States, et al.

    2011-07-01

    ... published in the Federal Register on October 13, 2010 (75 FR 62858); and (3) published summaries of the... Antitrust Division United States, et al. v. American Express Company, et al.; Public Comments and Response... Final Judgment in United States, et al. v. American Express Company, et al., Civil Action No....

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

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

    2013-01-01

    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 contain...

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

    Maqshoof Ahmad

    2013-12-01

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

  9. Environmental Factors Influencing Numbers of Rhizobium leguminosarum biovar trifolii and Its Bacteriophages in Two Field Soils.

    Lawson, K A; Barnet, Y M; McGilchrist, C A

    1987-05-01

    Fluctuations in numbers of Rhizobium leguminosarum biovar trifolii and its bacteriophages in two fields with different soil types were followed during a 17-month period in 1981 and 1982. Mean levels of both phage and rhizobia varied significantly (P soil and phage from 0 to 1.7 x 10 PFU/g of soil. Multivariate regression analysis showed rhizobial levels to be significantly and positively related to vegetation height and solar radiation, but not to mean temperature, precipitation, soil matric potential, or soil type. Rhizobiophage concentrations were significantly and positively related to soil matric potential and vegetation height. They were reduced in the silty clay loam soil, although the presence of 34% clay did not prevent phage multiplication and the occurrence of high phage levels. PMID:16347339

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

    Rosendahl, Lis

    1984-01-01

    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......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...... 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...

  11. Mekanisme Penambatan Nitrogen Udara oleh Bakteri Rhizobium Menginspirasi Perkembangan Teknologi Pemupukan Organik yang Ramah Lingkungan

    GEDE MENAKA ADNYANA

    2014-01-01

    Full Text Available Interaction of microbes with human living in the nature are able to seen from their capabilitiesimproving the environmental by composting waste of agriculture to become organic fertilizer. In thecontrary, the epidemic and infectious phatogens are also its contribution. In agriculture sector, the livingof microbes has been explored to keep the soil fertile, and to improve growth and plant production.The symbiosis of Rhizobium bacteria with the specific host plant from legumes is able to run because ofboth side giving a signal, where host plant give an organic molecoles called inducer. From the bacteriaside, also give an organic materials called nod factor. The step of nitrogen fixation mechanism can bedescribed from infection of root legume as the first step, followed by the nitrogen fixation by thebacteroid and synthesis of the nitrogen organic by host plant as the last step. These natural processesinspire finding and development of the ecologically organic fertilizer technology.

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

    Tadeusz Zając

    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.

  13. La plaquette à chevaux hypertrophiques de Lumentxa (Biscaye et les styles du Magdalénien supérieur/final dans le Pays Basque.

    Juan Mª Apellaniz

    1988-01-01

    Full Text Available Se ofrece un análisis de la plaqueta de hematites de la cueva de Lumentxa, fechada tradicionalmente en el Magdaleniense superior/final, desde el punto de vista formal y macroscópico. El examen del trazo y del desplazamiento o de la mano de las figuras del anverso, así como la identidad de estilo y forma, lleva al autor a sugerir la hipótesis de la misma autoría para las dos figuras, así como las diferencias de trazo y mano, así como la tendencia a la exageración de los caracteres estilísticos le conduce a suponer que el prótomo del reverso es atribuible a otro autor. El análisis formal permite atribuir esta obra a una corriente de carácter expresionista que se entrecruza con el estilo esquemático, uno de los más comunes del Magdaleniense superior/final. El autor, que ha sugerido la hipótesis del origen de la tendencia expresionista en la escuela de grabadores de La Madeleine (Tursac en otro trabajo, pone la plaqueta de Lumentxa en relación con aquella corriente y en concreto con un segundo momento del esquematismo expresionista que observa en ella. Considera la obra como un eco a punto de extinguirse de la corriente expresionista, de la que en el Cantábrico no quedan muchos recuerdos.

  14. Inoculação com Rhizobium e aplicação de nitrogênio em amendoim Comparison among Rhizobium strains inoculations and nitrogen applications on peanut, in field conditions

    Antonio Roberto Giardini; Eli Sidney Lopes; Angelo Savy Filho; André Martin Louis Neptune

    1985-01-01

    Existe, nas nossas condições, uma população autóctone de Rhizobium capaz de nodular o amendoim (Arachis hypogaea L.), mas pouco se sabe da contribuição do nitrogênio fixado para esta planta. Foram conduzidos dois ensaios no campo, em solo de baixa fertilidade, um no período "da seca" e outro no "das águas", comparando o crescimento e a produção de plantas de amendoim inoculado com Rhizobium selecionado, com o de plantas noduladas pela população autóctone, adubadas ou não com nitrogênio. A nod...

  15. 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

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

    2010-01-01

    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 ...

  16. 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

    Isnia Aparecida de Oliveira

    2000-03-01

    Full Text Available 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 cerrado soils.Estirpes de Rhizobium eficientes na nodulação do feijoeiro, isoladas de diferentes solos da região do cultivo dessa leguminosa nos cerrados brasileiros, foram caracterizadas via RAPD. Esse estudo mostrou grande heterogeneidade genética entre as estirpes de R. tropici e R. leguminosarum bv. phaseoli testadas e permitiu a definição de grupos genéticos, além de indicar os "primers" mais adequados para essa caracterização. Os grupos de estirpes geneticamente distintas podem ser usados em estudos de competitividade, importantes para obtenção de resultados positivos na inoculação dessa leguminosa em solos de cerrado.

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

    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.

  18. Tolerance Of Several Rhizobium Strain/Isolate To A1 and Their Interaction With Several Soybean Mutants

    Research activities to study the interaction of several soybean mutant and rhizobium strain/isalates were carried out. The first experiment to be involved screening of nine strain/isolates for tolerance to A1 acid stress. Five strains/isolates were considered tolerance. Further experiment with three strains/isolates with difference A1 concentrations, showed that the isolate no. 06 had the highest growth rate followed by isolate 09 and TAL 102. Experiment on interaction of five soybean mutant/varieties with those strains/isolates were carried out in nutrient culture. Mutant no. 21 and 43 showed better growth in solution containing 50 uM A1. Good nodulation occured in mutant no. 23 inoculated with Rhizobium isolate no. 06. This good symbiotic association should be studied further at higher A1 concentration. (authors). 14 refs, 6 tabs

  19. Quantitative 1 H NMR spectroscopy analysis of the poly(3-hydroxy alkanoate) extracted from Rhizobium meliloti cells

    1H NMR analysis was carried out to determine the nature and the concentration of the poly(3-hydroxyalkanoate) (PHA) accumulated by Rhizobium meliloti M5N1. The PHA was identified as being poly(3-hydroxybutyrate) (PHB). Benzene was shown to meet all the requirements of an internal reference for PHB quantification. NMR data were in good agreement with corresponding data obtained by Gas Chromatography (GC) analysis. (authors). 4 refs., 2 figs

  20. Lactose inhibits the growth of Rhizobium meliloti cells that contain an actively expressed Escherichia coli lactose operon.

    Timblin, C R; Kahn, M L

    1984-01-01

    Expression of the Escherichia coli lactose operon in Rhizobium meliloti 104A14 made the cells sensitive to the addition of the beta-galactosides lactose, phenyl-beta-D-galactoside, and lactobionic acid. Growth stopped when the beta-galactoside was added and viability decreased modestly during the next few hours, but little cell lysis was observed and the cells appeared normal. Protein synthesis was not inhibited. Growth was inhibited only when beta-galactosidase expression was greater than 16...

  1. Reexamination of the presence and linkage of 3-hydroxybutyryl substituents in the acidic capsular polysaccharide of Rhizobium trifolii 0403.

    Hollingsworth, R I; Dazzo, F B; Mort, A J

    1987-01-01

    We resolved previous conflicting results concerning the presence of 3-hydroxybutyryl substituents on the extracellular acidic polysaccharide from Rhizobium trifolii 0403. These substituents were indeed present in the polysaccharide and in the oligosaccharide fragments obtained by hydrogen fluoride solvolysis of the extracellular and capsular polysaccharides of the bacteria grown on plates. The 3-hydroxybutyrate substituent could be removed from the polysaccharide by 10 mM sodium deuteroxide w...

  2. Mutation of the Sensor Kinase chvG in Rhizobium leguminosarum Negatively Impacts Cellular Metabolism, Outer Membrane Stability, and Symbiosis

    Vanderlinde, Elizabeth M.; Yost, Christopher K.

    2012-01-01

    Two-component signal transduction systems (TCS) are a main strategy used by bacteria to sense and adapt to changes in their environment. In the legume symbiont Rhizobium leguminosarum biovar viciae VF39, mutation of chvG, a histidine kinase, caused a number of pleiotropic phenotypes. ChvG mutants are unable to grow on proline, glutamate, histidine, or arginine as the sole carbon source. The chvG mutant secreted smaller amounts of acidic and neutral surface polysaccharides and accumulated abno...

  3. 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

    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

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

    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

  5. Effcet of Rhizobium Inoculation on Growth and Nodulation of Albizzia procera,Albizzia lebbeck and Leucaena leucocephala

    U.K.ARYAL; M.A.U.MRIDHA; 等

    1999-01-01

    Effects of inoculation of Rhizobium suspension on nodulation and plant growth were examined with Albizzia procera,Albizzia lebbeck and Leucaena leucocephala seedlings grown on sterilized and non-sterilized soil media.Inoculation resulted in nodule number increases of 28.6,29.02and 23.9 times in sterilized soil and 3.4,3.6and 3.27 times in non-sterilized soil for A.procera,A.lebbeck and L.leucocephala seedlings respectively.Total dry mass increased by 127.6%,66.7%and 60.7% in sterilized soil and 100%,95.5%and 52.65% in non-sterilized soil for these three legume trees,respectively,after a period of two months.Significantly high inoculation responses of oot length,root diameter,collar diameter,shoot length,and dry mass of root,shoot,leaves and nodules were also observed in both steilized and non-sterilized soil media as compared to respective control treatments,The response to inoculation was strong in sterilized and modest in non-sterilized soils.The significantly higher response to Rhizobium inoculation over control in all the species tested suggested that application of Rhizobium greatly enhanced plant growth ,nodulation,biomass production and nitrogen-fixing activity of the nodules.

  6. Sulphation of Rhizobium sp. NGR234 Nod factors is dependent on noeE, a new host-specificity gene.

    Hanin, M; Jabbouri, S; Quesada-Vincens, D; Freiberg, C; Perret, X; Promé, J C; Broughton, W J; Fellay, R

    1997-06-01

    Rhizobia secrete specific lipo-chitooligosaccharide signals (LCOs) called Nod factors that are required for infection and nodulation of legumes. In Rhizobium sp. NGR234, the reducing N-acetyl-D-glucosamine of LCOs is substituted at C6 with 2-O-methyl-L-fucose which can be acetylated or sulphated. We identified a flavonoid-inducible locus on the symbiotic plasmid pNGR234a that contains a new nodulation gene, noeE, which is required for the sulphation of NGR234 Nod factors (NodNGR). noeE was identified by conjugation into the closely related Rhizobium fredii strain USDA257, which produces fucosylated but non-sulphated Nod factors (NodUSDA). R. fredii transconjugants producing sulphated LCOs acquire the capacity to nodulate Calopogonium caeruleum. Furthermore, mutation of noeE (NGRdelta noeE) abolishes the production of sulphated LCOs and prevents nodulation of Pachyrhizus tuberosus. The sulphotransferase activity linked to NoeE is specific for fucose. In contrast, the sulphotransferase NodH of Rhizobium meliloti seems to be less specific than NoeE, because its introduction into NGRdelta noeE leads to the production of a mixture of LCOs that are sulphated on C6 of the reducing terminus and sulphated on the 2-O-methylfucose residue. Together, these findings show that noeE is a host-specificity gene which probably encodes a fucose-specific sulphotransferase. PMID:9218762

  7. Synthesis of new glycosaminoglycans-like families by regioselective oxidation followed by sulphation of glucoglucuronan from Rhizobium sp. T1.

    Redouan, Elboutachfaiti; Emmanuel, Petit; Philippe, Michaud; Bernard, Courtois; Josiane, Courtois; Cedric, Delattre

    2012-08-01

    Glycosaminoglycan-like polysaccharides were prepared from Rhizobium sp. T1 polysaccharide using the TEMPO (nitroxyl radical 2,2,6,6-tetramethylpiperidine-1-oxyl radical) mediated oxidation. The structure of this new polyglucuronic acid sodium salt was analyzed by (13)C NMR spectra and HPAEC-PAD chromatography. Therefore, new polysaccharide containing only glucuronic acid monomers in both β-(1,3) and β-(1,4) linkage was obtained by the complete TEMPO-mediated oxidation of C6 primary hydroxyl groups of glucose of glucoglucuronan from Rhizobium sp. T1. Sulphation of this β-(1,3),β-(1,4)-polyglucuronic acid sodium salt was carried out using SO3/DMF reagent. These results suggested a new synthetic route using both TEMPO-mediated oxidation and sulphation of polysaccharides from Rhizobium sp. in developing glycosaminoglycans mimic to enhance the profitability of its low-cost production and processing industries. This novel carbohydrate derivative might find use as cheaper surrogates of glycosaminoglycans in the cosmetics and pharmaceutical fields. PMID:24750940

  8. VARIATION IN RHIZOBIUM GROWTH DUE TO SEED AND ROOT EXUDATES RELEASED FROM GAMMA IRRADIATED GLYCINE MAX SEEDS

    In this study, seeds of Glycine max Giza 122 were irradiated with gamma rays from 60Co source at various doses (10 to 200 Gy), sterilized and soaked into an aerated solution of CaSO4 (1 mmol and pH 6.5). The capacities of the released seed exudates (SEs) and root exudates (REs) to promote Rhizobium leguminosarum growth were investigated as well as biochemical analysis of the exudates was carried out. SE of both control and gamma irradiated seeds resulted in a higher Rhizobium population and polysaccharide production than RE. Relative to control, the highly effective doses in Rhizobium growth and polysaccharide production were 25 and 200 Gy; the former was a promoter while the later was an inhibitor. HPLC analysis of soluble carbohydrates revealed the presence of glucose (Glu), rhamnose (Rha) and fructose (Fru) in the SE and RE. Protein content in SE was lower than that in RE; the highest values were due to 10 Gy and 25 Gy in SE and RE, respectively. Free amino acids content in SE was increased up to 25 Gy then decreased while RE was increased by increasing gamma doses from 10 to 200 Gy

  9. Mission related to regulation and development of the photovoltaic sector in France. Final report; Mission relative a la regulation et au developpement de la filiere photovoltaique en France. Rapport final

    Charpin, J.M; Sine, A.; Helleisen, Ph.; Tlili, C. [Inspection Generale des Finances - IGF, 75 - Paris (France); Trink, C.; Stoffaes, Ch. [Conseil General de l' Industrie de l' Energie et des Technologies - CGIET, 75 - Paris (France)

    2010-07-01

    This report first gives an overview of the development of the photovoltaic stock in France (high potential with a middle term development constrained by high costs, consequences of a very strong increase of demands at the end of 2009, perspective of development at a rather high rate). Then, it outlines and discusses the financial consequences of such a high rate development, and the inadequacy between industrial objectives and development rate. It presents a development plan for this sector, stresses the need to implement new purchase obligation measures before the summer 2010, and to define a global action plan to be implemented at the beginning of 2011 for the development of photovoltaic electricity. Elements of international comparison are finally proposed

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

    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.

  11. Perturabation of nodular operation under salt and water deficit stress in rhizobium common bean symbiosis

    This work aims at the search for markers of tolerance to the osmotic stress and nodular efficiency of symbiosis Haricot Rhizobium. Thus, after having fixed the best period of hydroponic culture, we showed that a severe salt treatment generated an inhibition of the parameters of growth and nodulation. These inhibitions are accompanied by an inhibition of the enzymatic activities: ascorbate peroxidase (APX) and catalase (CAT), but an activation of peroxidase (POX) and superoxide dismutase (SOD), suggesting that these two antioxydants can be biochemical markers of the tolerance to salinity. To check the validity of these markers and to see the participation of the vegetable genotype in the response to the stress, we compared the effect of two concentrations salt 25 and 50 mM NaCe at two contrasting genotypes BAT477 tolerant and sensitive COCOT. This study illustrates the role of the vegetable genotype in the tolerance and efficiency and emphasize a significant result that SOD and POX constitute biochemical markers of tolerance to salinity. In order to ensure itself of the validity of this assumption in the event of water deficit stress, a treatment of 50 mM mannitol is applied to 16 symbioses formed by four genotypes of bean BAT477, COCOT, Flamingo and BRB17 inoculated by four strains of rhizobium CIAT899, 12 to 3, 1 to 6 and 8 to 3. This study permits us to make a screening of these symbioses according to their efficiency and their tolerance based on parameters of growth, of fixing and extent of the antioxydant enzymatic activities. It gets clear that the response of enzymatic antioxydants is in relation to the intrinsic potentialities of the partners of symbioses and appears to act as of the first stages of recognition plants bacterium. It will be retained that activities POX and SOD are markers of nodular tolerance. The CAT is the enzyme most connected to each partner of symbiosis and the APX would play a rather functional role. The heterogeneity of found answer

  12. Isolation of Rhizobium Spp. Bacteria which as Used Microbial Fertilizer from Wild Leguminosarum Plants

    Hatice Öğütcü

    2014-04-01

    Full Text Available In our study used wild leguminous plants (Medicago sativa, M. lupulina and M. varia Erzurum belongs to the high altitude (2000 - 2500m regions ( Palandöken mountain, Alibaba mountain, Turnagöl mountain, Hasanbaba mountain, Eğerli mountain, Yıldırım mountain, Çubuklu mountain, Deveboynu locality, Kayakyolu locality, Telsizler and Dumlu hill were collected during the months of June and July. Nodules were obtained from this plant were sterilized, YMA (Yeast Mannitol Agar plates were streaked and petri dishes 28+1ºC were incubated for 3-5 days. Colonies appear after incubation typically constitute (white, clear or slightly opaque, mucosity, round, raised 39 isolates were selected and transferred to tubes and refrigerated YMA were stored at +4ºC. In the next stage, cytological and biochemical analyzes of these isolates were studied to determine. For this purpose isolates; YMA containing bromothymol blue and congo red reproduction, gram stain reaction, movement and subjected to catalase and oxidase tests were evaluated. The cytological and biochemical analysis of results showed that 28 of 39 strains belonged to Rhizobium spp.

  13. Symbiont abundance is more important than pre-infection partner choice in a Rhizobium - legume mutualism.

    Van Cauwenberghe, Jannick; Lemaire, Benny; Stefan, Andrei; Efrose, Rodica; Michiels, Jan; Honnay, Olivier

    2016-07-01

    It is known that the genetic diversity of conspecific rhizobia present in root nodules differs greatly among populations of a legume species, which has led to the suggestion that both dispersal limitation and the local environment affect rhizobial genotypic composition. However, it remains unclear whether rhizobial genotypes residing in root nodules are representative of the entire population of compatible symbiotic rhizobia. Since symbiotic preferences differ among legume populations, the genetic composition of rhizobia found within nodules may reflect the preferences of the local hosts, rather than the full diversity of potential nodulating rhizobia present in the soil. Here, we assessed whether Vicia cracca legume hosts of different provenances select different Rhizobium leguminosarum genotypes than sympatric V. cracca hosts, when presented a natural soil rhizobial population. Through combining V. cracca plants and rhizobia from adjacent and more distant populations, we found that V. cracca hosts are relatively randomly associated with rhizobial genotypes. This indicates that pre-infection partner choice is relatively weak in certain legume hosts when faced with a natural population of rhizobia. PMID:27269381

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

    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 (γ-R). The relations between survival and fluence of UV, and survival and absorbed dose of γ-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 γ-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

  15. Enzymatic tailoring of ornithine in the biosynthesis of the Rhizobium cyclic trihydroxamate siderophore vicibactin.

    Heemstra, John R; Walsh, Christopher T; Sattely, Elizabeth S

    2009-10-28

    To acquire iron, the N(2)-fixing, symbiotic bacterium Rhizobium sp. produce the cyclic trihydroxamate siderophore vicibactin, containing a 30-membered trilactone scaffold. Herein we report the overproduction and purification of the six proteins VbsACGOLS in the bacterial host Escherichia coli and the reconstitution of the biosynthesis of vicibactin from primary metabolites. The flavoprotein VbsO acts as a pathway-initiating l-ornithine N(5)-hydroxylase, followed by VbsA, which transfers (R)-3-hydroxybutyryl- from the CoA thioester to N(5)-hydroxyornithine to yield N(5)-((R)-3-hydroxybutyryl)-N(5)-hydroxy-l-ornithine. VbsL is a PLP-dependent epimerase acting at C(2) of the 10 atom monomer unit. VbsS, a nonribosomal peptide synthetase free-standing module, then activates N(5)-((R)-3-hydroxybutyryl)-N(5)-hydroxy-d-ornithine as the AMP anhydride on the way to cyclotrimerization to the vicibactin scaffold. The last step, tris-acetylation of the C(2) amino group of desacetyl-d-vicibactin to the mature siderophore vicibactin, is catalyzed distributively by VbsC, using three molecules of acetyl-CoA. PMID:19778043

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

    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.

  17. Increased effectiveness of competitive rhizobium strains upon inoculation of Cajanus cajan

    A field study was conducted in lysimeters containing 15N-enriched soil to determine the effects of four competitive rhizobium strains upon yield parameters of pigeon peas (Cajanus cajan). The greatest differences observed were in seed yields; strain P132 effected the highest seed yield (121 +/- 20 g per plant), and the control strain (indigenous rhizobia) effected the lowest yield (43.9 +/- 8 g per plant). With the exception of seeds and pods, the dry matter weights were not different. Although there appeared to be no effect by inoculum strains on the fractional content of N derived from biological nitrogen fixation when the total plant biomass was considered, strains P132 and 401 partitioned more of the N derived from fixation into seeds and leaves than did the other strains. Because the seeds comprised the major portion of plant N, more total N and more N derived from biological nitrogen fixation (about half of total N) were found in plants inoculated with P132, whereas the smallest amount was found in the uninoculated controls. P132 was also the best competitor with respect to indigenous rhizobia and accounted for all of the nodules found on the plants in which it was inoculated

  18. Rhizobium Radiobacter Infection in a 27-Year-Old African American Woman With Munchausen Syndrome.

    Sawhney, Sameer; Naab, Tammey; Oneal, Partricia

    2016-08-01

    Rhizobium radiobacter is an opportunistic, usually saprophytic, gram-negative bacillus found in agricultural soil. Isolation from blood has been reported most often in hospitalized patients harboring malignant neoplasms or human immunodeficiency virus (HIV) associated immunosuppression, who have catheter or medical device-related febrile neutropenia; treatment involves removal of the catheter or implanted medical device.(1)Herein, we report a case of a 27-year-old African American woman with sickle cell anemia who sought treatment of generalized body pain, shaking, chills, dyspnea, and fever, suggestive of sickle cell crisis. As part of her work up, routine blood cultures were drawn, revealing the presence of a Gram negative bacillus that was identified as the nonfermenter bacillus R. radiobacter The patient displayed a unique infection with R. radiobacter sepsis in a patient secondary to self-injection of organic material into a peripheral line during hospitalization. The growth of an unusual organism in the blood of a patient, without the usual risk factors of R. radiobacter, raised suspicion of a factitious psychiatric disorder known as Munchausen syndrome, which was confirmed when we discovered self-injection of feces and dirt into a central intravenous (IV) line. PMID:27107290

  19. Molecular phylogenetic analysis of Rhizobium sullae isolated from Algerian Hedysarum flexuosum.

    Aliliche, Khadidja; Beghalem, Hamida; Landoulsi, Ahmed; Chriki, Ali

    2016-07-01

    Isolates from root nodules of Hedysarum flexuosum, sampled from north region of Algeria, were analyzed on the basis of their phenotypic and molecular characteristics. They were tested for their tolerance to NaCl, pH, temperatures, antibiotics and heavy metals resistance. Interestingly, the isolate Hf_04N appeared resistant to ZnCl2 (50 μg/mL) and grew at high saline concentration up to 9 %. The phylogenetic positions of five isolates were studied by comparative sequence analysis of 16S rRNA, recA, nifH and nodD genes. There were grouped close to the Rhizobium sullae type strain in relation to their 16S rRNA, recA and nifH genes-based phylogenies. By contrast, the tree of nodD gene was not congruent with ribosomal, housekeeping and nitrogen fixation genes. We suggest that our strains have a novel nodD gene. The detection of conserved domains of NodD protein and nitrogenase reductase enzyme, confirm their ability to nodulate and fix nitrogen. PMID:27034287

  20. Role of nickel in membrane-bound hydrogenase and nickel metabolism in Rhizobium japonicum

    The membrane-bound hydrogenase of Rhizobium japonicum requires nickel for activity. Radioactive 63Ni co-migrates with hydrogenase activity in native gel systems and co-elutes with purified hydrogenase form an affinity matrix column. A simplified scheme for the purification of hydrogenase has been developed and constitutes the first report of the aerobic purification of this enzyme from R. japonicum. The aerobic purification utilizes the general affinity matrix. Reactive Red 120-agarose and results in higher specific activity and yield of enzyme than previously reported. The stability of aerobically purified hydrogenase to oxygen is substantially greater than that reported for anaerobically isolated enzyme. Reduction of the aerobically purified enzyme in the presence of oxygen, however, results in the rapid loss of activity. R. japonicum cells accumulate nickel during heterotrophic growth and as non-growing cells. The hydrogenase constitutive mutant SR470 accumulates substantially greater amounts of nickel under both conditions. Kinetic studies indicate that the nickel uptake system in the hydrogenase constitutive mutant SR470 is upregulated relative to SRwt cells. The uptake system is specific for nickel, although a 10-fold excess (relative to nickel) of copper or zinc inhibits nickel uptake. The nickel uptake system appears to require energy. Under nickel-free conditions hydrogenase protein is not synthesized as determined by cross-reactivity with antibodies directed against hydrogenase, indicating that nickel regulates the formation of the enzyme as well as being a constituent of the active protein

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

    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

  2. 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

    Tehuni Orlando González

    2008-09-01

    Full Text Available 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 greenhouse 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.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 acaso, 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 seq

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

    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.

  4. 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.

    Ormeño-Orrillo Ernesto

    2012-12-01

    Full Text Available Abstract Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-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

  5. Genetic and structural analysis of the Rhizobium meliloti fixA, fixB, fixC, and fixX genes.

    Earl, C D; Ronson, C W; Ausubel, F M

    1987-01-01

    The fixA, fixB, fixC, and fixX genes of Rhizobium meliloti 1021 constitute an operon and are required for nitrogen fixation in alfalfa nodules. DNA homologous to the R. meliloti fixABC genes is present in all other Rhizobium and Bradyrhizobium species examined, but fixABC-homologous sequences were found in only one free-living diazotroph, Azotobacter vinelandii. To determine whether the fixABCX genes share sequence homology with any of the 17 Klebsiella pneumoniae nif genes, we determined the...

  6. Problemes methodologiques poses par l'extraction et la recuperation des bacteries telluriques pour leur quantification par immunofluorescence

    Crozat, Y.; Cleyet-Marel, Jean Claude

    1984-01-01

    Afin d’améliorer la valeur quantitative de la technique de dénombrement des bactéries telluriques (Rhizobium japonicum) par immunofluorescence, on compare différents modes d’extraction et de récupération. L’utilisation de membranes en polycarbonates (Nucléopores) supprime les 40 p. 100 de pertes occasionnées par les membranes cellulosiques (Millipores) classiquement employées. Parmi les différents floculants testés, Ca(OH)2/MgCO3(2/5) permet d’obtenir les meilleurs résultats. Cependant po...

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

    Sanchez Cañizares, 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 dos ge...

  8. Measurement of the proton motive force in Rhizobium meliloti with the Escherichia coli lacY gene product.

    Gober, J W; Kashket, E R

    1985-01-01

    An Escherichia coli lac operon constitutive for lacY was subcloned into the EcoRI site of a wide-host-range plasmid of the Q incompatibility group, and the resulting recombinant plasmid was introduced into Tn5-generated Lac- mutants of Rhizobium meliloti. The R. meliloti transconjugants accumulated lactose about 1,000-fold, equivalent to a proton motive force of -170 to -180 mV, not significantly different from the values calculated from the distributions of weak acids and lipophilic cations.

  9. Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti.

    Handelsman, J; Brill, W J

    1985-01-01

    Erwinia herbicola was isolated from roots of plants derived from surface-sterilized seeds of all alfalfa varieties that were tested. Some of these E. herbicola strains affected nodulation by certain strains of Rhizobium meliloti. In previously published work we presented the isolation of slow-and fast-nodulating variants from a single culture of R. meliloti 102F51. In the absence of E. herbicola, the slow-nodulating variant induced the formation of nodules on alfalfa as rapidly as the faster-...

  10. Response of chickpea (cicer arietinum L.) to various levels of phosphorus and rhizobium inoculation under rainfed condition

    A field experiment was conducted to evaluate the effect of phosphorus (P) levels and Rhizobium inoculation on yield-components and grain-yield of (chickpea c.v. NIFA-88) under rain fed conditions at Arid Zone Research Institute, Dera Ismail Khan, during 2003- 04. The treatments consisted of P levels; 0, 30, 60 and 90 kg ha-I, with and without inoculum. A basal dose of 20 kg ha-l nitrogen was applied just before sowing, at the time of seedbed preparation. The experiment was laid out according to the randomized complete block design, with three replications. The results showed significant variation in number of pods per plant, 1000 seed weight and grain yield, with the application of P and Rhizobium inoculum. The maximum number of pods per plant (25.00) was recorded in the plots receiving 60 kg P/sub 2/ O/sub 5/ h a/sup -l/ plus inoculum, but was statistically at par with the pods produced by the treatment of 90 kg P/sub 2/ O/sub 5/ ha-l plus inoculum (24.67). Phosphorus levels plus inoculum gave 11.87 percent increased number of pods per plant over mere P levels. Similarly, the maximum 1000 seed weight of 197.0 g was recorded at the rate 90 and 60 kg P/sub 2/O/sub 5/ ha-1 plus inoculum and 90 kg P/sub 2/ O/sub 5/ ha-l alone. The highest grain-yield of 1,317 kg ha/sup -l/ was obtained from the treatments where P was applied at the rate 90 and 60 kg ha-I with inoculum. The grain yield was increased 8.54 percent when P levels were applied with inoculums, as compared to Palone, on average basis. Hence, it can be concluded from the study that (I) Rhizobium inoculum application alone can increase yield, and (II) 60 kg P/sub 2/ O/sub 5/ ha-l is the most economical dose to be used with Rhizobium inoculum for obtaining higher grain-yield of chickpea. (author)

  11. Rhizobium meliloti mutants that overproduce the R. meliloti acidic Calcofluor-binding exopolysaccharide

    The acidic Calcofluor-binding exopolysaccharide of Rhizobium meliloti Rm1021 plays one or more critical roles in nodule invasion and possible in nodule development. Two loci, exoR and exoS, that effect the regulation of synthesis of this exopolysaccharide were identified by screening for derivatives of strain Rm1021 that formed mucoid colonies that fluoresced extremely brightly under UV light when grown on medium containing Calcofluor. The exopolysaccharide produced in large quantities by the exoR95::Tn5 and exoS96::Tn5 strains was indistinguishable from that produced by the parental strain Rm1021, and its synthesis required the function of at least the exoA, exoB, and exoF genes. Both the exoR and exoS loci were located on the chromosome, and the exo96::Tn5 mutation was 84% linked to the trp-33 mutation by ΦM12 transduction. Synthesis of the Calcofluor-binding exopolysaccharide by strain Rm1021 was greatly stimulated by starvation for ammonia. In contrast, the exoR95::Tn5 mutant produced high levels of exopolysaccharide regardless of the presence or absence of ammonia in the medium. The exoS96::Tn5 mutant produced elevated amounts of exopolysaccharide in the presence of ammonia, but higher amounts were observed after starvation for ammonia. The presence of either mutation increased the level of expression of exoF::TnphoA and exoP::TnphoA fusions. Analyses of results obtained when alfalfa seedlings were inoculated with the exoR95::Tn5 strain indicated that the mutant strain could not invade nodules. However, pseudorevertants that retained the original exoR95::Tn5 mutant but acquired unlinked suppressors so that they produced an approximately normal amount of exopolysaccharide were able to invade nodules and fix nitrogen

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

    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.

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

    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.

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

    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

  15. Regulation of nod factor sulphation genes in Rhizobium tropici CIAT899.

    Manyani, H; Sousa, C; Soria Díaz, M E; Gil-Serrano, A; Megías, M

    2001-06-01

    Rhizobium tropici CIAT899 is a tropical symbiont able to nodulate various legumes such as Leucaena, Phaseolus, and Macroptilium. Broad host range of this species is related to its Nod factors wide spectrum. R. tropici contains Nod factors sulphation nod genes, nodHPQ genes, which control nodulation efficiency in Leucaena. To study nodHPQ regulation, we carried out different interposon insertions in its upstream region. One of these generated interruptions, nodI mutant produced nonsulphated Nod factors suggesting a possible dependence of these genes on nodI upstream region. Moreover, analysis results of lacZ transcriptional fusions with these genes in symbiotic plasmid showed dependence of these genes on NodD protein. In order to determine nodHPQ organization, we studied the effect of interposon insertion upstream of each lacZ transcriptional fusion, and the data obtained was used to indicate that nodHPQ belong to the nodABCSUIJ operon. However, comparison between nodP::lacZ beta-galactosidase activity in the symbiotic plasmid and in the pHM500 plasmid (containing nodHPQ genes) suggested constitutive expression in free living, and flavonoid inducible expression in symbiotic conditions. Constitutive nodHPQ expression may play a role in bacterial house-keeping metabolism. On the other hand, the transference of R. tropici nodHPQ genes to other rhizobia that do not present sulphated substitutions demonstrated that NodH protein sulphotransference is specific to C6 at the reducing end. PMID:11467733

  16. Reactive Oxygen Species and Nitric Oxide Control Early Steps of the Legume – Rhizobium Symbiotic Interaction

    Damiani, Isabelle; Pauly, Nicolas; Puppo, Alain; Brouquisse, Renaud; Boscari, Alexandre

    2016-01-01

    The symbiotic interaction between legumes and nitrogen-fixing rhizobium bacteria leads to the formation of a new organ, the nodule. Early steps of the interaction are characterized by the production of bacterial Nod factors, the reorientation of root-hair tip growth, the formation of an infection thread (IT) in the root hair, and the induction of cell division in inner cortical cells of the root, leading to a nodule primordium formation. Reactive oxygen species (ROS) and nitric oxide (NO) have been detected in early steps of the interaction. ROS/NO are determinant signals to arbitrate the specificity of this mutualistic association and modifications in their content impair the development of the symbiotic association. The decrease of ROS level prevents root hair curling and ITs formation, and that of NO conducts to delayed nodule formation. In root hairs, NADPH oxidases were shown to produce ROS which could be involved in the hair tip growth process. The use of enzyme inhibitors suggests that nitrate reductase and NO synthase-like enzymes are the main route for NO production during the early steps of the interaction. Transcriptomic analyses point to the involvement of ROS and NO in the success of the infection process, the induction of early nodulin gene expression, and the repression of plant defense, thereby favoring the establishment of the symbiosis. The occurrence of an interplay between ROS and NO was further supported by the finding of both S-sulfenylated and S-nitrosylated proteins during early symbiotic interaction, linking ROS/NO production to a redox-based regulation of the symbiotic process. PMID:27092165

  17. Reactive Oxygen Species and Nitric Oxide Control Early Steps of the Legume - Rhizobium Symbiotic Interaction.

    Damiani, Isabelle; Pauly, Nicolas; Puppo, Alain; Brouquisse, Renaud; Boscari, Alexandre

    2016-01-01

    The symbiotic interaction between legumes and nitrogen-fixing rhizobium bacteria leads to the formation of a new organ, the nodule. Early steps of the interaction are characterized by the production of bacterial Nod factors, the reorientation of root-hair tip growth, the formation of an infection thread (IT) in the root hair, and the induction of cell division in inner cortical cells of the root, leading to a nodule primordium formation. Reactive oxygen species (ROS) and nitric oxide (NO) have been detected in early steps of the interaction. ROS/NO are determinant signals to arbitrate the specificity of this mutualistic association and modifications in their content impair the development of the symbiotic association. The decrease of ROS level prevents root hair curling and ITs formation, and that of NO conducts to delayed nodule formation. In root hairs, NADPH oxidases were shown to produce ROS which could be involved in the hair tip growth process. The use of enzyme inhibitors suggests that nitrate reductase and NO synthase-like enzymes are the main route for NO production during the early steps of the interaction. Transcriptomic analyses point to the involvement of ROS and NO in the success of the infection process, the induction of early nodulin gene expression, and the repression of plant defense, thereby favoring the establishment of the symbiosis. The occurrence of an interplay between ROS and NO was further supported by the finding of both S-sulfenylated and S-nitrosylated proteins during early symbiotic interaction, linking ROS/NO production to a redox-based regulation of the symbiotic process. PMID:27092165

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

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

    2015-01-01

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

  19. Diglyceride Kinase Activity in Cell Extracts of Rhizobium meliloti: Evidence for a Diglyceride Cycle during Cyclic β-1,2-Glucan Biosynthesis

    Hunt, William P.; Gore, Richard S.; Miller, Karen J.

    1991-01-01

    In this article, we provide evidence for the presence of diglyceride kinase activity in cell extracts of Rhizobium meliloti 1021. Characterization of the rhizobial enzyme revealed that it shares many properties with the diglyceride kinase of Escherichia coli. A possible role for this enzyme during cyclic β-1,2-glucan biosynthesis is discussed.

  20. The structure and molecular mechanics calculations of the cyclic (1 → 2)-β- D-glucan secreted by Rhizobium tropici CIAT 899

    Gil Serrano, Antonio M.; Franco-Rodríguez, Guillermo; González-Jiménez, Isabel; Tejero-Mateo, Pilar; Molina, José Molina; Dobado, J. A.; Megías, Manuel; Romero, Maria Jesús

    1993-12-01

    The structure of the extracellular cyclic (1 → 2)-β- D-glucan secreted by Rhizobium tropici CIAT 899 has been studied by methylation analysis, 1D and 2D NMR experiments, HPLC and FAB-MS. Molecular mechanics (MM2) and theoretical 3JHH coupling constants calculations were performed.

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

    Skøt, L.; Hirsch, P. R.; Witty, J. F.

    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...... the lowest carbon costs of N2 fixation (7.10–8.10 μmol C/μmol 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 μmol C/μmol 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...

  2. Homology of genes for exopolysaccharide synthesis in Rhizobium leguminosarum and effect of cloned exo genes on nodule formation

    A 5.4 kb BamHI fragment of Rhizobium leguminosarum (R.l.) bv. trifolii TA1 was found to carry genes involved in exopolysaccharide synthesis (exo genes). This fragment was strongly hybridized to the total DNA from DNA from R.l. bv. viciae and bv. phaseoli digested with EcoRI. No homology was found with total DNA of R. melilotic and Rhizobium sp. NGR 234. The exo genes R.l. bv. trifolii TA1 conjugally introduced into R.l. bv. viciae 1302 considerably affected the symbiosis: the nodules induced on vetch were abortive and did not fix nitrogen. On the other hand, Phaseolus beans infected with R.l. bv. trifolii exo genes formed the nitrogen-fixing nodules. It can be conduced that additional copies of exo genes introduced into wild type R.l. strains can disturb the synthesis of acidic exopolysaccharides and affect symbiosis of the plants forming indeterminate nodules, but do not affect symbiosis of the plants forming the determinate nodules. (author). 29 refs, 2 figs, 2 tabs

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

    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 fertilizer use efficiency (FUE%) was enhanced by AM infection. Dual inoculums of Rh + Azo induced highest content of proline in leaves. (Authors)

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

    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.

  5. Bourges (Cher), ZAC Avaricum. Évolution d'un quartier urbain de Bourges du 1er s. ap. J.-C. jusqu'à nos jours, Rapport final d'opération de fouille préventive, volume 1 à 4 : Volume 1 à 4 : texte, plans et études spécialisées.

    Fondrillon, Mélanie; Marot, Emmanuel; Troadec, Jacques

    2012-01-01

    Ces quatre volumes sont issus du rapport final d'opération de fouille préventive qui présente les découvertes archéologiques faites sur le site de la ZAC Avaricum à Bourges (Cher, France). Le premier concerne la présentation diachronique de la stratification du site et des structures. Le deuxième porte sur les plans. Les troisième et quatrième concernent les différentes études de spécialistes.

  6. Mise en relation de la qualité des produits et des paysages : enseignements issus de l'analyse comparée entre le fromage AOC Saint Nectaire et la marque viande bovine du parc naturel régional du Morvan : rapport final

    Dobremez, L.; Aznar, O.; Candau, J.; Ernoult, C.; Ginelli, L.; Guerreiro, F.; Landré, F.; Michelin, Y.; Ménadier, L.; Perret, E.; Rapey, H.; Vollet, D.

    2008-01-01

    / L'objectif de cette étude est de caractériser les liens entre des paysages et des produits dont la qualité est certifiée par un cahier des charges. Sur deux terrains et produits, le fromage AOC Saint Nectaire et la marque viande bovine du parc naturel régional du Morvan, différentes approches (géographique, agronomique, sociologique et économique) ont été mises en ½uvre et croisées afin d'identifier les éléments matériels caractéristiques du paysage et ceux liés à la représentation des acte...

  7. 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

    Eulene Francisco da Silva

    2009-01-01

    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, com 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.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

  8. Crystallization and preliminary X-ray diffraction studies of maleylacetate reductase from Rhizobium sp. strain MTP-10005

    Maleylacetate reductase from Rhizobium sp. strain MTP-10005 has been crystallized using the sitting-drop vapour-diffusion method and microseeding. The crystals contained one dimeric molecule per asymmetric unit and diffracted to 1.79 Å resolution. Maleylacetate reductase (EC 1.3.1.32), which catalyzes the reduction of maleylacetate to 3-oxoadipate, plays an important role in the aerobic microbial catabolism of resorcinol. The enzyme has been crystallized at 293 K by the sitting-drop vapour-diffusion method supplemented with a microseeding technique, using ammonium sulfate as the precipitating agent. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 56.85, b = 121.13, c = 94.09 Å, β = 101.48°, and contained one dimeric molecule in the asymmetric unit. It diffracted to 1.79 Å resolution

  9. Regulatory role of the sequences downstream from nodD3 P1 promoter of Rhizobium meliloti

    2000-01-01

    The 660 bp region between nodD3 P1 promoter and the following coding region of Rhizobium meliloti has been studied.This region is designated "downstream sequences".It consists of two potential open reading frames,ORF1 and ORF2.Studies on the role of the downstream sequences on the activity of nodD3 P1 with nod D3(P1)-lacZ fusion show that deletion of the sequences containing ORF2 causes the increase of the activity of the fusion; on the contrary,addition of extra copies of ORF2 markedly decreases the activity of the fusion.These results indicate that the product of ORF2 plays a negative role in the expression of nod D3.

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

    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.

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

    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

  12. Crystallization and preliminary X-ray diffraction studies of maleylacetate reductase from Rhizobium sp. strain MTP-10005

    Fujii, Tomomi; Goda, Yuko [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Yoshida, Masahiro; Oikawa, Tadao [Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680 (Japan); Hata, Yasuo, E-mail: hata@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2008-08-01

    Maleylacetate reductase from Rhizobium sp. strain MTP-10005 has been crystallized using the sitting-drop vapour-diffusion method and microseeding. The crystals contained one dimeric molecule per asymmetric unit and diffracted to 1.79 Å resolution. Maleylacetate reductase (EC 1.3.1.32), which catalyzes the reduction of maleylacetate to 3-oxoadipate, plays an important role in the aerobic microbial catabolism of resorcinol. The enzyme has been crystallized at 293 K by the sitting-drop vapour-diffusion method supplemented with a microseeding technique, using ammonium sulfate as the precipitating agent. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 56.85, b = 121.13, c = 94.09 Å, β = 101.48°, and contained one dimeric molecule in the asymmetric unit. It diffracted to 1.79 Å resolution.

  13. Fluorescence studies with malate dehydrogenase from rhizobium japonicum 3I1B-143 bacteroids: a two-tryptophan containing protein

    Ghiron, Camillo A.; Eftink, Maurice R.; Waters, James K.; Emerich, David W.

    1990-05-01

    A number of fluorescence studies, both of trp residues and bound NADH, have been reported for porcine MDH. The large number of trp residues (6) complicates the interpretation of some studies. To circumvent this we have performed studies with a two tryptophan (per subunit) MDH from Rhizobium japonicum 311B-143 bacteroids. We have performed phase/modulation fluorescence lifetime measurements, as a function of temperature and added quencher KI, in order to resolved the 1.3 ns (blue) and 6.6 ns (red) contributions from the two classes of trp residues. Anisotropy decay studies have also been performed. The binding of NADH dynamically quenches the fluorescence of both tip residues, but, unlike mammalian cytoplasmic and mitochondrial MDH, there is not a large enhancement in fluorescence of bound NADH upon forming a ternary complex with either tartronic acid or D-malonate.

  14. Comparison of the nitrogen-15 and conventional methods to determine N2 fixing capacity of chickpea by rhizobium strains

    The N2 fixing capacity of 8 strains of rhizobium ciceri (45, 68, 51,620, 29,18,23 and 31) in association with two cicer cultivars (Akcin-91 and Izmir-92) was evaluated under growth room conditions as a preliminary screening prior to field experimentation. The ''1''5N isotope method (A-value) was used to quantify the % Ndfa and actual amounts of N2 fixed. In addition to this, other conventional methods (dry matter, N content, total N uptake, difference method and symbiotic effectiveness) were also investigated in the comparison. The results obtained show that 18 and 31 number of strains could be successfully used as inoculant both cultivar

  15. Evapotranspiration (ET) covers.

    Rock, Steve; Myers, Bill; Fiedler, Linda

    2012-01-01

    about specific projects using ET covers. There are three general approaches for non-conventional cover systems to achieve approval for installation; the first is when equivalent performance to conventional final cover systems can be demonstrated directly on site. This is the approach used by the Sandia study, by most ACAP sites, and the Rocky Mountain Arsenal. A second approach is used when there are data from a site specific study such as an ACAP installation at a site that has analogous soil and climate conditions. Several sites in Colorado and Southern California have achieved approval based on data from similar sites. The third most common approach for regulatory approval is by installation of data collection systems with the agreement that the permanence of the ET cover installation is contingent on success of the cover in meeting certain performance goals. This article is intended as an introduction to the topic and is not intended to serve as guidance for design or construction, nor indicate the appropriateness of using an ET cover systems at a particular site. PMID:22574378

  16. NrcR, a New Transcriptional Regulator of Rhizobium tropici CIAT 899 Involved in the Legume Root-Nodule Symbiosis.

    Del Cerro, Pablo; Rolla-Santos, Amanda A P; Valderrama-Fernández, Rocío; Gil-Serrano, Antonio; Bellogín, Ramón A; Gomes, Douglas Fabiano; Pérez-Montaño, Francisco; Megías, Manuel; Hungría, Mariangela; Ollero, Francisco Javier

    2016-01-01

    The establishment of nitrogen-fixing rhizobium-legume symbioses requires a highly complex cascade of events. In this molecular dialogue the bacterial NodD transcriptional regulators in conjunction with plant inducers, mostly flavonoids, are responsible for the biosynthesis and secretion of Nod factors which are key molecules for successful nodulation. Other transcriptional regulators related to the symbiotic process have been identified in rhizobial genomes, including negative regulators such as NolR. Rhizobium tropici CIAT 899 is an important symbiont of common bean (Phaseolus vulgaris L.), and its genome encompasses intriguing features such as five copies of nodD genes, as well as other possible transcriptional regulators including the NolR protein. Here we describe and characterize a new regulatory gene located in the non-symbiotic plasmid pRtrCIAT899c, that shows homology (46% identity) with the nolR gene located in the chromosome of CIAT 899. The mutation of this gene, named nrcR (nolR-like plasmid c Regulator), enhanced motility and exopolysaccharide production in comparison to the wild-type strain. Interestingly, the number and decoration of Nod Factors produced by this mutant were higher than those detected in the wild-type strain, especially under salinity stress. The nrcR mutant showed delayed nodulation and reduced competitiveness with P. vulgaris, and reduction in nodule number and shoot dry weight in both P. vulgaris and Leucaena leucocephala. Moreover, the mutant exhibited reduced capacity to induce the nodC gene in comparison to the wild-type CIAT 899. The finding of a new nod-gene regulator located in a non-symbiotic plasmid may reveal the existence of even more complex mechanisms of regulation of nodulation genes in R. tropici CIAT 899 that may be applicable to other rhizobial species. PMID:27096734

  17. The development of plasmid-free strains of Agrobacterium tumefaciens by using incompatibility with a Rhizobium meliloti plasmid to eliminate pAtC58.

    Hynes, M F; Simon, R; Pühler, A

    1985-03-01

    Agrobacterium tumefaciens strains LBA275 and LBA290 were cured of their cryptic plasmid pAtC58 by the introduction of the Rhizobium meliloti plasmid pRme41a, which is incompatible with pAtC58. pRme41a and pTiC58, the resident Ti plasmid of LBA275, were subsequently eliminated by growth at supraoptimal temperature (40 degrees C). The resulting plasmid-free Agrobacterium strains, UBAPF1 and UBAPF2, have proved extremely useful for the study of Rhizobium plasmids. The loss of the cryptic plasmid pAtC58 has no effect on the tumor-forming ability of the Agrobacterium strains; when the Ti plasmid is present, normal tumors are formed on Kalanchoe daigremontiana. PMID:4001194

  18. Sesbania rostrata, légumineuse à nodules caulinaires : fixation symbiotique d'azote, et utilisation comme engrais vert

    Moudiongui, A.

    1988-01-01

    Des souches de #Rhizobium$ isolées de #Sesbania rostrata$ provenant de différents lieux géographiques du Sénégal, ont été analysées. Leur comparaison avec la "souche de tige" de référence ORS571 a permis de mettre en évidence des différences au niveau des parentés immunologiques, du contenu plasmidique, de l'activité nitrogénase en condition de dérépression, et de l'efficience de la symbiose. L'azote combiné, ammoniacal ou nitrique affecte à la fois la nodulation et l'activité réductrice d'ac...

  19. N2-Fixation in Alfalfa (Medicago sativa L.) Seedlings and Rhizobium meliloti L. Grown in Vitro Under Salt and Drought Stresses

    Mohamad, Ramzi Muhiddin

    1987-01-01

    Alfalfa, Medicago sativa L., cultivars, breeding lines and germplasm releases (populations) and Rhizobium meliloti L. strains that exhibit nitrogen fixation efficiency and tolerance to salinity and drought stresses should enhance seedling establishment, increase yields, reduce nitrogen dependency on petroleum-based nitrogen fertilizers, and allow wider use of irrigated lands in semiarid and a rid regions. In vitro experiments were conducted to determine relative salt (sodium chloride -- NaCl)...

  20. Endogenous lectins from cultured soybean cells: isolation of a protein immunologically cross-reactive with seed soybean agglutinin and analysis of its role in binding of Rhizobium japonicum

    1986-01-01

    Incubation of Rhizobium japonicum with the cultured soybean cell line SB-1, originally derived from the roots of Glycine max, resulted in specific adhesion of the bacteria to the plant cells. This binding interaction appears to be mediated via carbohydrate recognition, since galactose can inhibit the heterotypic adhesion but glucose cannot. Affinity chromatography, on a Sepharose column derivatized with N- caproyl-galactosamine, of the supernatant fraction of a SB-1 cell suspension after enzy...

  1. Assignment of Biochemical Functions to Glycosyl Transferase Genes Which Are Essential for Biosynthesis of Exopolysaccharides in Sphingomonas Strain S88 and Rhizobium leguminosarum

    Pollock, Thomas J.; van Workum, Wilbert A. T.; Thorne, Linda; Mikolajczak, Marcia J.; Yamazaki, Motohide; Kijne, Jan W.; Armentrout, Richard W.

    1998-01-01

    Glycosyl transferases which recognize identical substrates (nucleotide-sugars and lipid-linked carbohydrates) can substitute for one another in bacterial polysaccharide biosynthesis, even if the enzymes originate in different genera of bacteria. This substitution can be used to identify the substrate specificities of uncharacterized transferase genes. The spsK gene of Sphingomonas strain S88 and the pssDE genes of Rhizobium leguminosarum were identified as encoding glucuronosyl-(β1→4)-glucosy...

  2. The 32-kilobase exp gene cluster of Rhizobium meliloti directing the biosynthesis of galactoglucan: genetic organization and properties of the encoded gene products.

    Becker, A.; Rüberg, S; Küster, H.; Roxlau, A A; Keller, M; Ivashina, T; H.P. Cheng; Walker, G C; Pühler, A

    1997-01-01

    Proteins directing the biosynthesis of galactoglucan (exopolysaccharide II) in Rhizobium meliloti Rm2011 are encoded by the exp genes. Sequence analysis of a 32-kb DNA fragment of megaplasmid 2 containing the exp gene cluster identified previously (J. Glazebrook and G. C. Walker, Cell 56:661-672, 1989) revealed the presence of 25 open reading frames. Homologies of the deduced exp gene products to proteins of known function suggested that the exp genes encoded four proteins involved in the bio...

  3. The urease structural gene ureA in Rhizobium meliloti is preceded by an open reading frame necessary for urease activity.

    Miksch, G

    1994-12-01

    An open reading frame (ORF1) located upstream of the urease structural gene ureA in Rhizobium meliloti strain AK631 was cloned and characterized by DNA sequencing. Comparison of the amino acid sequence revealed partial homology with the urease accessory gene ureD of Klebsiella aerogenes and Proteus mirabilis. Mutational analysis of ORF1 showed that the gene is necessary for urease activity. Its function is still unknown. PMID:7813887

  4. Analysis of cellular fatty acids and phenotypic relationships of Agrobacterium, Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium species using the Sherlock microbial identification system

    Tighe, S.W.; de Lajudie, Philippe; Dipietro, K.; Lindström, K.; Nick, G; Jarvis, B. D. W.

    2000-01-01

    Previous studies have demonstrated that cellular fatty acid analysis is a useful tool for identifying unknown strains of rhizobia and establishing taxonomic relationships between the species. In this study, the fatty acid profiles of over 600 strains belonging to the genera #Agrobacterium$, #Bradyrhizobium$, #Mesorhizobium$, #Rhizobium$ and #Sinorhizobium$ were evaluated using the gas-chromatography-based Sherlock Microbial Identification System (MIS). Data collected with the MIS showed that ...

  5. Sequence and analysis of the rpoN sigma factor gene of rhizobium sp. strain NGR234, a primary coregulator of symbiosis.

    van Slooten, J C; Cervantes, E; Broughton, W J; Wong, C H; Stanley, J

    1990-01-01

    We report the nucleotide sequence of the rpoN gene from broad-host-range Rhizobium sp. strain NGR234 and analyze the encoded RPON protein, a sigma factor. Comparative analysis of the deduced amino acid sequence of RPON from NGR234 with sequences from other gram-negative bacteria identified a perfectly conserved RPON box unique to RPON sigma factors. Symbiotic regulatory phenotypes were defined for a site-directed internal deletion within the coding sequence of the rpoN gene of Rhizobium strain NGR234: they included quantitative nodulation kinetics on Vigna unguiculata and microscopic analysis of the Fix- determinate nodules of V. unguiculata and Macroptilium atropurpureum. RPON was a primary coregulator of nodulation and was implicated in establishment or maintenance of the plant-synthesized peribacteroid membrane. Phenotypes of rpoN in Rhizobium strain NGR234 could be grouped as symbiosis related, rather than simply pleiotropically physiological as in free-living bacteria such as Klebsiella pneumoniae and Pseudomonas putida. Images PMID:2211497

  6. Agrice et les tensioactifs

    Rocher Magali

    2001-01-01

    Agrice, Agriculture pour la chimie et l’énergie, est un groupement d’intérêt scientifique qui a pour objet l’animation, le financement, le suivi et l’évaluation de programmes de recherche et développement portant sur les nouvelles valorisations des produits et coproduits d’origine agricole dans les domaines de l’énergie, de la chimie et des matériaux. Aujourd’hui les programmes de recherche et développement sur les tensioactifs sont renforcés, plus sélectifs et plus directement tournés vers l...

  7. Entrepreneuriat et innovations organisationnelles : pratiques et principes

    Fonrouge, Cecile

    2008-01-01

    Les innovations de structure, systèmes et pratiques de gestion participent à une dynamique de changement qui les rendent dignes d'intérêt en entrepreneuriat. Trois cas d'innovations internes sont étudiés : un réseau d'entreprises, un système de numérisation des données de conception et des pratiques visant à concilier l'exploration et l'exploitation du potentiel technologique. Les conclusions portent sur l'effet organisationnel des choix technologiques et la place essentielle des entrepreneur...

  8. ACTENA : Auscultation des cables tendus non accessibles : programme de recherche national supporté par l'Agence National de la Recherche et par Electricité de France : Rapport scientifique final

    Chazelas, Jean Louis; FORTIER, Stéphane; Abraham, Odile; BAYLASSAC, Jean Paul; BENMEDAKHENE, Salim; BOURSE, Gérard; FRACHELET, Franck; CHAIX, Jean François; COMELOUP, Gilles; Cottineau, Louis Marie; DEFER, Didier; Degauque, Pierre; Deschamps, Marc; GAILLET, Laurent; Garnier, Vincent

    2009-01-01

    Le programme de recherches ACTENA visait à ouvrir de nouvelles approches et à développer différentes méthodes d'auscultation non destructives des câbles tendus non accessibles dans le génie civil, essentiellement les câbles de précontrainte et les câbles d'ancrage des murs de soutènement. Le diagnostic de la pérennité de la précontrainte appelle deux réponses : la force de tension est-elle pérenne ? les ruptures passées ou en cours dans le câble réduisent-elle gravement les coefficients de sé...

  9. Syndicats et associations

    Bars, Loïc Le; Barthélémy, Martine; Bellanger, Emmanuel; Béroud, Sophie; Béthouart, Bruno; Boussion, Samuel; Brodiez, Axelle; Brouster, Pascale Le; Capdevielle, Jacques; Chatriot, Alain; Coffin, Jean-Christophe; Diebolt, Évelyne; Dreyfus, Michel; Faniel, Jean; Frajerman, Laurent

    2015-01-01

    Les syndicats sont et demeurent des associations dans la large acceptiondu terme. Ils émergent et se développent dans l'espace du travail où préexistent nombre d'associations, d'initiatives et d'intitulés divers. Syndicats et associations remplissent de surcroît, souvent, les mêmes fonctions et nourrissent, parfois, des objectifs similaires. L'ouvrage qui rassemble des contributions émanant d'historiens, de sociologues et de politistes s'essaie à analyser la diversité des relations qui se son...

  10. Enhanced Synthesis of Antioxidant Enzymes, Defense Proteins and Leghemoglobin in Rhizobium-Free Cowpea Roots after Challenging with Meloydogine incognita

    Jose T. A. Oliveira

    2014-11-01

    Full Text Available The root knot nematodes (RKN, Meloydogine spp., particularly Meloidogyne incognita and Meloidogyne javanica species, parasitize several plant species and are responsible for large annual yield losses all over the world. Only a few available chemical nematicides are still authorized for RKN control owing to environmental and health reasons. Thus, plant resistance is currently considered the method of choice for controlling RKN, and research performed on the molecular interactions between plants and nematodes to identify genes of interest is of paramount importance. The present work aimed to identify the differential accumulation of root proteins of a resistant cowpea genotype (CE-31 inoculated with M. incognita (Race 3 in comparison with mock-inoculated control, using 2D electrophoresis assay, mass spectrometry identification and gene expression analyses by RT-PCR. The results showed that at least 22 proteins were differentially represented in response to RKN challenge of cowpea roots mainly within 4–6 days after inoculation. Amongst the up-represented proteins were SOD, APX, PR-1, β-1,3-glucanase, chitinases, cysteine protease, secondary metabolism enzymes, key enzymes involved in ethylene biosynthesis, proteins involved in MAPK pathway signaling and, surprisingly, leghemoglobin in non-rhizobium-bacterized cowpea. These findings show that an important rearrangement in the resistant cowpea root proteome occurred following challenge with M. incognita.

  11. [Comparison of the adaptive potential for Rhizobium leguminosarum bv. viceae nodule bacterial populations isolated in natural ecosystems and agrocenoses].

    Kurchak, O N; Provorov, N A; Simarov, B V

    2011-04-01

    Polymorphism analysis was performed in Rhizobium leguminosarum bv. viceae populations isolated from geographically distant regions of Ukraine and Middle Asia. Examination of cultural, biochemical, and symbiotic traits revealed interpopulation differences, which were attributed to the difference in conditions between natural ecosystems and agrocenoses. Vetch has high species diversity and is not cultivated in Middle Asia, and the corresponding rhizobial population displayed higher genetic diversity and higher polymorphism of adaptive traits ensuring saprophytic development in soil and the rhizosphere, including melanin synthesis (35%) and active exopolysaccharide production (90%). Strains of the Ukrainian population had a lower exopolysaccharide production (10%), did not produce melanin, had higher herbicide resistance, and utilized glucose and succinate (main components of plant root exudation) as carbon sources. Strains capable of efficient symbiosis with Vicia villosa Roth. had a higher frequency in the Middle Asian than in the Ukrainian population, especially among strains isolated from soil (80 and 35%, respectively). In addition, strains of the Middle Asian population better competed for nodulation. It was assumed that the formation of rhizobial populations in vetch cultivation regions (Ukraine) is aimed at adaptation to ectosymbiotic (rhizospheric) interactions with plants and anthropogenic stress factors, while strains of the vetch original center (Middle Asia) are mostly adapted to the endosymbiotic interaction and to natural edaphic stress factors. PMID:21675237

  12. Biotin production under limiting growth conditions by Agrobacterium/Rhizobium HK4 transformed with a modified Escherichia coli bio operon.

    Shaw; Lehner; Fuhrmann; Kulla; Brass; Birch; Tinschert; Venetz; Venetz; Sanchez; Tonella; Hochstrasser

    1999-06-01

    The E. coli biotin (bio) operon was modified to improve biotin production by host cells: (a) the divergently transcribed wild-type bio operon was re-organized into one transcriptional unit; (b) the wild-type bio promoter was replaced with a strong artificial (tac) promoter; (c) a potential stem loop structure between bioD and bioA was removed; and (d) the wild-type bioB ribosomal binding site (RBS) was replaced with an artificial RBS that resulted in improved bioB expression. The effects of the modifications on the bio operon were studied in E. coli by measuring biotin and dethiobiotin production, and bio gene expression with mini-cells and two-dimensional polyacrylamide gel electrophoresis. The modified E. coli bio operon was introduced into a broad host-range plasmid and used to transform Agrobacterium/Rhizobium HK4, which then produced 110 mg L-1 of biotin in a 2-L fermenter, growing on a defined medium with diaminononanoic acid as the starting material. Biotin production was not growth-phase dependent in this strain, and the rate of production remained high under limiting (maintenance) and zero growth conditions. PMID:10455485

  13. [Role of Bacterial Adhesin RAPA1 in Formation of Efficient Symbiosis of Rhizobium leguminosarum with Bean Plants].

    Nigmatullina, L R; Lavina, A M; Vershinina, Z R; Baimiev, Al Kh

    2015-01-01

    Bacterial adhesins, the proteins responsible for attachment of plant growth-promoting rhizobacteria to plant roots, are involved in formation of stable associative symbioses. In the present work enhanced expression of the rapA1 adhesin gene in Rhizobium leguminosarum PVu5 was shown to improve the efficiency of nodulation on bean roots inoculated with the modified strain. The rapA1 gene was cloned into the pJN105Turbo plasmid, this construct was used for transformation of R. leguminosarum PVu5, bean plants were inoculated by this transgenic strain, and efficiency of root nodule formation was determined. In the plants treated with rapA1-transgenic rhizobia, the number of root nodules was on average two times higher than in the plants inoculated with the original strain. Aggregation of R. leguminosarum was achieved when the rapA1 gene expression was enhanced either in rhizobia or in the co-cultured modified strain E. coli pJN105TurboRapA1. PMID:26964360

  14. Characterisation of SalRAB a salicylic acid inducible positively regulated efflux system of Rhizobium leguminosarum bv viciae 3841.

    Adrian J Tett

    Full Text Available Salicylic acid is an important signalling molecule in plant-microbe defence and symbiosis. We analysed the transcriptional responses of the nitrogen fixing plant symbiont, Rhizobium leguminosarum bv viciae 3841 to salicylic acid. Two MFS-type multicomponent efflux systems were induced in response to salicylic acid, rmrAB and the hitherto undescribed system salRAB. Based on sequence similarity salA and salB encode a membrane fusion and inner membrane protein respectively. salAB are positively regulated by the LysR regulator SalR. Disruption of salA significantly increased the sensitivity of the mutant to salicylic acid, while disruption of rmrA did not. A salA/rmrA double mutation did not have increased sensitivity relative to the salA mutant. Pea plants nodulated by salA or rmrA strains did not have altered nodule number or nitrogen fixation rates, consistent with weak expression of salA in the rhizosphere and in nodule bacteria. However, BLAST analysis revealed seventeen putative efflux systems in Rlv3841 and several of these were highly differentially expressed during rhizosphere colonisation, host infection and bacteroid differentiation. This suggests they have an integral role in symbiosis with host plants.

  15. Genetic diversity of a natural population of Rhizobium leguminosarum bv. viciae nodulating plants of Vicia faba in the Vesuvian area.

    Ventorino, Valeria; Chiurazzi, Mario; Aponte, Maria; Pepe, Olimpia; Moschetti, Giancarlo

    2007-12-01

    A total of 98 rhizobial strains, isolated during the winter of the years 2003 (35 isolates), 2004 (33 isolates), and 2005 (30 isolates) were analyzed to determine the genetic diversity of the natural population nodulating Vicia faba plants and to identify dominant genotypes. All isolates were identified as Rhizobium leguminosarum bv. viciae by biovar-specific polymerase chain reaction amplification of the nodC gene. Intraspecific DNA polymorphism was evaluated through the restriction endonucleases analysis combined with pulsed-field gel electrophoresis. Four genotypes characterized 53% of the isolates, showing a high occurrence; moreover, they were recovered over the 3 years, thus showing a lasting persistence in the soil, which could mean a high degree of saprophytic competitiveness. The richness, diversity, and dominance indexes of genotypes were calculated to monitor the evolution of the rhizobial population during the 3 years. The genetic diversity of the analyzed strains decreased along the 3 years. In fact, the biodiversity index H' decreased from 2.6 in the first and second year to 1.9 in the third year; probably, as a result of bean monocropping, specific genotypes of Rh. leguminosarum bv. viciae were naturally selected. PMID:17899266

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

    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

  17. Biologic fixation of nitrogen in irradiated rhizobium strips; Fixacao biologica do nitrogenio em estirpes de rizobianas irradiadas

    Caribe, Rebeka Alves; Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear

    2002-07-01

    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-{gamma}). The D{sub 37} values for the rhizobial strain SEMIA 4077 were 43 J.m{sup -2} (UV) and 32 Gy (R-{gamma}) and for the SEMIA 6145 were 45 J.m{sup -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)

  18. Symbiotic Efficiency of Native and Exotic Rhizobium Strains Nodulating Lentil (Lens culinaris Medik. in Soils of Southern Ethiopia

    Wondwosen Tena

    2016-02-01

    Full Text Available Lentil plays a major role in the food and nutritional security of low income Ethiopian families because of the high protein content of their seed; however, their productivity typically is low largely due to soil fertility limitations. Field and pot experiments were conducted during the 2011 cropping season to determine the effectiveness of Rhizobium strains on two cultivars of lentil in Southern Ethiopia. Six rhizobial inoculant treatments (four indigenous and two commercial inoculants, a nitrogen (N fertilizer treatment (50 kg·urea·ha−1 and an absolute control (non-inoculated non-fertilized were used. Inoculated plants produced significantly higher nodule number, nodule dry weight, grain yield and yield components than non-inoculated non-fertilized plants. Inoculation of field grown lentil with rhizobia strain Lt29 and Lt5 enhanced seed yield by 59% and 44%, respectively. Whereas urea fertilization enhanced yields by 40%. Similarly, grain yields were increased during the pot experiment by 92% and 67% over the control treatments by inoculation with Lt29 and Lt5, respectively. The highest levels of N fixation were achieved in plants inoculated with Lt29 (65.7% Ndfa. Both field and pot investigations indicate that inoculation of lentil with native rhizobial strains replace the need for inorganic N fertilization to optimize lentil yields.

  19. Flocculating Properties and Production of the Compound Bioflocculant by Rhizobium Radiobacter F2 and Bacillus Sphaeicus F6

    Lixin Li; Lingyan Feng; Fang Ma; Qianshen Zhao

    2015-01-01

    A compound bioflocculant CBF, produced by mixed culture of Rhizobium radiobacter F2 and Bacillus sphaeicus F6, was investigated with regard to its production and flocculating properties. The optimization of the culture medium constituents including carbon source, nitrogen source and C/N ratio, metal ions and ionic strength on CBF production were studied. Flocculating properties of CBF were examined by a series of experiments and CBF had good flocculating activities in kaolin suspension with divalent cations and stable over wide range of pH. Studies of the flocculating properties revealed that the flocculation could be stimulated by cations Ca2+, Mg2+, Fe2+, Al3+and Fe3+. In addition, it was stable at 4-30℃ in the presence of CaCl2 . It was found to be effective for flocculation of a kaolin suspension under neutral and weak alkaline conditions ( pH 7�0-9�0 ) , and flocculating activities of higher than 95% were obtained when the CBF concentrations among 6-14 mg/L at pH 8�0. The results of this study indicate that CBF is a potential replacement of conventional synthetic flocculants and is widely applied in water treatment and downstream processing of food and fermentation industries.

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

    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.

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

    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 site

  2. Complete genome sequence of Rhizobium leguminosarum bv. trifolii strain WSM1325, an effective microsymbiont of annual Mediterranean clovers.

    Reeve, Wayne [Murdoch University, Perth, Australia; O' Hara, Graham [Murdoch University, Perth, Australia; Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Ardley, Julie [Murdoch University, Perth, Australia; Brau, Lambert [Murdoch University, Perth, Australia; Nandesena, Kemanthi [Murdoch University, Perth, Australia; Tiwari, Ravi [Murdoch University, Perth, Australia; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Han, Cliff [Los Alamos National Laboratory (LANL); Brettin, Thomas S [ORNL; Land, Miriam L [ORNL; Ovchinnikova, Galina [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Melino, Vanessa [Murdoch University, Perth, Australia; Denton, Matthew [Department of Primary Industries, Victoria, Australia; Yates, Ron [Murdoch University, Perth, Australia; Howieson, John [Murdoch University, Perth, Australia

    2010-01-01

    Rhizobium leguminosarum bv trifolii is a soil-inhabiting bacterium that that has the capacity to be an effective nitrogen fixing microsymbiont of a diverse range of annual Trifolium (clover) species. Strain WSM1325 is an aerobic, motile, non-spore forming, Gram-negative rod isolated from root nodules collected in 1993 from the Greek Island of Serifos. WSM1325 is manufactured commercially in Australia as an inoculant for a broad range of annual clovers of Mediterranean origin due to its superior attributes of saprophytic competence, nitrogen fixation and acid-tolerance. Here we describe the basic features of this organism, together with the complete genome sequence, and annotation. This is the first completed genome sequence for a microsymbiont of annual clovers. We reveal that its genome size is 7,418,122 bp encoding 7,232 protein-coding genes and 61 RNA-only encoding genes. This multipartite genome contains 6 distinct replicons; a chromosome of size 4,767,043 bp and 5 plasmids of size 828,924, 660,973, 516,088, 350,312 and 294,782 bp.

  3. Maize growth promotion by inoculation with Azospirillum brasilense and metabolites of Rhizobium tropici enriched on lipo-chitooligosaccharides (LCOs).

    Marks, Bettina Berquó; Megías, Manuel; Ollero, Francisco Javier; Nogueira, Marco Antonio; Araujo, Ricardo Silva; Hungria, Mariangela

    2015-12-01

    There is an increasing interest in the development and use of inoculants carrying plant growth-promoting bacteria (PGPB) in crops of agronomic interest. The great majority of the inoculants commercialized worldwide contain rhizobia for legume crops, but the use of PGPB as Azospirillum spp. for non-legume is expanding, as well as of inoculants combining microorganisms and microbial metabolites. In this study we evaluated the effects of inoculants containing Azospirillum brasilense with or without metabolites of Rhizobium tropici strain CIAT 899 highly enriched in lipo-chitooligosaccharides (LCOs) in six field experiments performed for three summer crop seasons in Brazil with maize (Zea mays L.). Inoculants and metabolites were applied either at sowing by seed inoculation, or by leaf spray at the V3 stage of plant growth. Improvement in shoot dry weight (SDW) and total N accumulated in shoots (TNS) by single, but especially by dual inoculation was observed in some of the experiments. Statistically significant increases in grain yield in relation to the non-inoculated control were observed in five out of six experiments when maize was inoculated with Azospirillum supplied with enriched metabolites of R. tropici applied by seed or leaf spray inoculation. The results give strength to the development of a new generation of inoculants carrying microorganisms and microbial molecules. PMID:26567001

  4. RHIZOBIUM ETLI USDA9032 ENGINEERED TO PRODUCE A PHENAZINE ANTIBIOTIC INHIBITS THE GROWTH OF FUNGAL PATHOGENS BUT IS IMPAIRED IN SYMBIOTIC PERFORMANCE

    Phenazine antibiotics produced by Pseudomonas spp. play a major role in preventing various plant diseases. In this study, the phenazine biosynthesis locus of P. chlororaphis O6, a plant growth-promoting rhizobacteria (PGPR), was introduced into several symbiotic bacteria belonging to the family Rh...

  5. 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

    Recourt, Kees; Brussel, Anton A.N. van; Driessen, Arnold J. M.; Lugtenberg, Ben J. 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 ...

  6. Final seminar of the 11A025 research project : Instrumentation and monitoring methods for civil engineering applications : Laboratoire Central des Ponts et Chaussées, Bouguenais, 14-15 décembre 2005

    LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

    2005-01-01

    Le contrôle de structure ainsi que les outils associés s'y rattachant prennent de plus en plus une solide et croissante importantce pour les utilisateurs des méthodes expérimentales dans le génie civil. Les systèmes de mesure servent non seulement dans le cadre du suivi de la pathologie d'un pont ou d'un comportement défectueux, mais également en tant que vrais systèmes automatisés de prise de décision ou d'outils pour le contrôle actif de structure. De nos jours, ces systèmes comportent les ...

  7. 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

    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)

  8. A 13C-NMR study of exopolysaccharide synthesis in Rhizobium meliloti Su47 strain

    Tavernier, P.; Portais, J.-C.; Besson, I.; Courtois, J.; Courtois, B.; Barbotin, J.-N.

    1998-02-01

    Metabolic pathways implied in the synthesis of succinoglycan produced by the Su47 strain of R. meliloti were evaluated by 13C-NMR spectroscopy after incubation with [1{-}13C] or [2{-}13C] glucose. The biosynthesis of this polymer by R. meliloti from glucose occurred by a direct polymerisation of the introduced glucose and by the pentose phosphate pathway. Les voies métaboliques impliquées dans la synthèse du succinoglycane produit par la souche Su47 de R. meliloti ont été évaluées par la spectroscopie de RMN du carbone 13 après incubation des cellules avec du [1{-}13C] ou [2{-}13C] glucose. La biosynthèse de ce polymère à partir du glucose se produit par polymérisation directe du glucose et par la voie des pentoses phosphate.

  9. Caracterización de una permeasa de Rhizobium leguminosarum en el transporte de molibdeno y en la simbiosis con guisantes.

    Alaminos Hervás, Elena

    2011-01-01

    Rhizobium leguminosarum es una bacteria que establece relaciones simbióticas con guisantes gracias a la fijación de nitrógeno en unas estructuras radiculares llamadas nódulos. La nitrogenasa es la enzima responsable de fijar nitrógeno y necesita molibdeno para su funcionamiento. Estudios recientes en otra bacteria, Rhodobacter capsulatus, han descubierto que existe una permeasa, PerO, implicada en el transporte de molibdeno al interior celular. En nuestro equipo de investigación disponemos ...

  10. Sequence Analysis of Hypothetical Lysine Exporter Genes of Rhizobium leguminosarum bv. trifolii from Calamine Old Waste Heaps and Their Evolutionary History

    Oleńska, Ewa; Małek, Wanda

    2013-01-01

    The aim of this study was to identify heavy metal detoxification system in Rhizobium leguminosarum bv. trifolii isolated from Trifolium repens inhabiting old (70–100 years) Zn–Pb waste heaps in Poland by PCR reaction with czcD1 and czcD2 primers. By sequence analysis, four different genotypes of obtained amplicons were identified among eight examined isolates. Their sequence similarity ranged 91–99 %. They indicated the highest sequence identity to the hypothetical lysine exporter gene of R. ...

  11. Conservation of PcaQ, a transcriptional activator of pca genes for catabolism of phenolic compounds, in Agrobacterium tumefaciens and Rhizobium species.

    Parke, D

    1996-01-01

    In Agrobacterium tumefaciens A348, control of five genes for catabolism of the phenolic compound protocatechuate to beta-ketoadipate is exerted by the gene pcaQ. The product of pcaQ is a transcriptional activator which is distinct from regulators of the beta-ketoadipate pathway characterized in other bacterial groups. An investigation of whether pcaQ is present and conserved in related Rhizobium species employed Southern hybridization and an agrobacterial pcaD::LacZ promoter probe plasmid. Th...

  12. Genetic analysis of the Rhizobium meliloti bacA gene: functional interchangeability with the Escherichia coli sbmA gene and phenotypes of mutants.

    Ichige, A; Walker, G C

    1997-01-01

    The Rhizobium meliloti bacA gene encodes a function that is essential for bacterial differentiation into bacteroids within plant cells in the symbiosis between R. meliloti and alfalfa. An Escherichia coli homolog of BacA, SbmA, is implicated in the uptake of microcin B17, microcin J25 (formerly microcin 25), and bleomycin. When expressed in E. coli with the lacZ promoter, the R. meliloti bacA gene was found to suppress all the known defects of E. coli sbmA mutants, namely, increased resistanc...

  13. 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

    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

  14. RELIGION, DROIT ET DEVELOPPEMENT : ISLAM ET CHRETIENTE

    Facchini, François

    2005-01-01

    Cet article se propose d'expliquer le sous-développement de l'aire musulmane et le développement de l'aire chrétienne par le facteur religieux. Il soutient, dans une première section, que le christianisme a été un facteur de développement parce qu'il a permis de reconnaître les libertés et les droits individuels (1). Il montre, ensuite, que l'islam comme religion y a été moins favorable parce que l'interprétation de la parole du prophète qui a été retenue et son origine politique l'ont condui...

  15. Monstres et murailles, Alexandre et bicornu, mythes et bon sens

    Jean-Louis Bacqué-Grammont

    2009-05-01

    Full Text Available Parmi les mythes récurrents à travers les lieux et les âges, celui du bâtisseur de murailles défendant une humanité civilisée contre l'Autre, sous ses aspects les plus effrayants, a connu une durable fortune depuis le prototype d'un Alexandre le Grand légendaire jusqu'à des avatars composites, bien vivaces dans nombre de littératures islamiques.En trois points différents de cet inépuisable domaine de recherche, chacun des auteurs a procédé à un sondage sommaire. Il en ressort maint exemple de continuités, de parallélismes et de confluences complexes, mais aussi les premiers signes d'érosion des mythes sous l'effet d'un esprit critique attisé par le vent d'Occident.

  16. Beaurepaire et Escavalon

    Saly, Antoinette

    2014-01-01

    Lorsque Perceval sort chevalier de chez Gornemant de Goort, c'est pour rencontrer aussitôt l'aventure où se profilera son destin. A peine a-t-il retrouvé les grands bois familiers que sa chevauchée le mène à un chastel fort et bien seant (v. 1707). Au fur et à mesure qu'il approche, cependant, ne s'offre qu'un paysage désolé de lande et d'eau : Defors les murs n'avoit neant Fors mer et aive et terre gaste (vv. 1708-1709). Il franchit un pont chancelant et se heurte à une porte close. Ses cris...

  17. Interacción de Tsukamurella paurometabola C-924 con Rhizobium leguminosarum biovar phaseoli CFH en el cultivo de frijol

    Marieta Marín Bruzos

    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 < 0.01 en los porcentajes de germinación de las plantas tratadas con microorganismos de forma independiente o conjunta con respecto al control sin inocular. Se determinó que la inoculación de T. paurometabola C-924 afectó el proceso de nodulación de R. leguminosarum biovar phaseoli CFH. Sin embargo, esto no incidió de manera significativa en la altura de las plantas ni en el diámetro del tallo, ya que no se encontraron diferencias entre los tratamientos para estos parámetros. Para el número de hojas, los mejores resultados se obtuvieron con la aplicación de T. paurometabola C-924. Se concluyó que la interacción de T. paurometabola C-924 con R. leguminosarum biovar phaseoli CFH en el frijol estimuló significativamente la germinación de las semillas y el número de hojas de las plantas con respecto al control sin inocular. Aunque la aplicación de T. paurometabola C-924 no favoreció la nodulación de R. leguminosarum biovar phaseoli CFH, esto no afectó las características fenológicas del cultivo.

  18. Microcystin-tolerant Rhizobium protects plants and improves nitrogen assimilation in Vicia faba irrigated with microcystin-containing waters.

    Lahrouni, Majida; Oufdou, Khalid; El Khalloufi, Fatima; Benidire, Loubna; Albert, Susann; Göttfert, Michael; Caviedes, Miguel A; Rodriguez-Llorente, Ignacio D; Oudra, Brahim; Pajuelo, Eloísa

    2016-05-01

    Irrigation of crops with microcystins (MCs)-containing waters-due to cyanobacterial blooms-affects plant productivity and could be a way for these potent toxins entering the food chain. This study was performed to establish whether MC-tolerant rhizobia could benefit growth, nodulation, and nitrogen metabolism of faba bean plants irrigated with MC-containing waters. For that, three different rhizobial strains-with different sensitivity toward MCs-were used: RhOF96 (most MC-sensitive strain), RhOF125 (most MC-tolerant strain), or Vicz1.1 (reference strain). As a control, plants grown without rhizobia and fertilized by NH4NO3 were included in the study. MC exposure decreased roots (30-37 %) and shoots (up to 15 %) dry weights in un-inoculated plants, whereas inoculation with rhizobia protects plants toward the toxic effects of MCs. Nodulation and nitrogen content were significantly impaired by MCs, with the exception of plants inoculated with the most tolerant strain RhOF125. In order to deep into the effect of inoculation on nitrogen metabolism, the nitrogen assimilatory enzymes (glutamine synthetase (GS) and glutamate synthase (GOGAT)) were investigated: Fertilized plants showed decreased levels (15-30 %) of these enzymes, both in shoots and roots. By contrast, inoculated plants retained the levels of these enzymes in shoots and roots, as well as the levels of NADH-GOGAT activity in nodules. We conclude that the microcystin-tolerant Rhizobium protects faba bean plants and improves nitrogen assimilation when grown in the presence of MCs. PMID:26865488

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

    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

  20. Evidence of transfer by conjugation of type IV secretion system genes between Bartonella species and Rhizobium radiobacter in amoeba.

    Watcharee Saisongkorh

    Full Text Available BACKGROUND: Bartonella species cospeciate with mammals and live within erythrocytes. Even in these specific niches, it has been recently suggested by bioinformatic analysis of full genome sequences that Lateral Gene Transfer (LGT may occur but this has never been demonstrated biologically. Here we describe the sequence of the B. rattaustraliani (AUST/NH4(T circular plasmid (pNH4 that encodes the tra cluster of the Type IV secretion system (T4SS and we eventually provide evidence that Bartonella species may conjugate and exchange this plasmid inside amoeba. PRINCIPAL FINDINGS: The T4SS of pNH4 is critical for intracellular viability of bacterial pathogens, exhibits bioinformatic evidence of LGT among bacteria living in phagocytic protists. For instance, 3 out of 4 T4SS encoding genes from pNH4 appear to be closely related to Rhizobiales, suggesting that gene exchange occurs between intracellular bacteria from mammals (bartonellae and plants (Rhizobiales. We show that B. rattaustraliani and Rhizobium radiobacter both survived within the amoeba Acanthamoeba polyphaga and can conjugate together. Our findings further support the hypothesis that tra genes might also move into and out of bacterial communities by conjugation, which might be the primary means of genomic evolution for intracellular adaptation by cross-talk of interchangeable genes between Bartonella species and plant pathogens. CONCLUSIONS: Based on this, we speculate that amoeba favor the transfer of genes as phagocytic protists, which allows for intraphagocytic survival and, as a consequence, promotes the creation of potential pathogenic organisms.

  1. Non-pathogenic Rhizobium radiobacter F4 deploys plant beneficial activity independent of its host Piriformospora indica.

    Glaeser, Stefanie P; Imani, Jafargholi; Alabid, Ibrahim; Guo, Huijuan; Kumar, Neelendra; Kämpfer, Peter; Hardt, Martin; Blom, Jochen; Goesmann, Alexander; Rothballer, Michael; Hartmann, Anton; Kogel, Karl-Heinz

    2016-04-01

    The Alphaproteobacterium Rhizobium radiobacter F4 (RrF4) was originally characterized as an endofungal bacterium in the beneficial endophytic Sebacinalean fungus Piriformospora indica. Although attempts to cure P. indica from RrF4 repeatedly failed, the bacterium can easily be grown in pure culture. Here, we report on RrF4's genome and the beneficial impact the free-living bacterium has on plants. In contrast to other endofungal bacteria, the genome size of RrF4 is not reduced. Instead, it shows a high degree of similarity to the plant pathogenic R. radiobacter (formerly: Agrobacterium tumefaciens) C58, except vibrant differences in both the tumor-inducing (pTi) and the accessor (pAt) plasmids, which can explain the loss of RrF4's pathogenicity. Similar to its fungal host, RrF4 colonizes plant roots without host preference and forms aggregates of attached cells and dense biofilms at the root surface of maturation zones. RrF4-colonized plants show increased biomass and enhanced resistance against bacterial leaf pathogens. Mutational analysis showed that, similar to P. indica, resistance mediated by RrF4 was dependent on the plant's jasmonate-based induced systemic resistance (ISR) pathway. Consistent with this, RrF4- and P. indica-induced pattern of defense gene expression were similar. In clear contrast to P. indica, but similar to plant growth-promoting rhizobacteria, RrF4 colonized not only the root outer cortex but also spread beyond the endodermis into the stele. On the basis of our findings, RrF4 is an efficient plant growth-promoting bacterium. PMID:26495996

  2. Nodulation of cowpeas and survival of cowpeas Rhizobia in acid, aluminum-rich soils. [Vigna unguiculata; Rhizobium

    Hartel, P.G.; Whelan, A.M.; Alexander, M.

    1983-01-01

    A study was undertaken to determine whether the reduced nodulation of cowpeas (Vigna unguiculata (L.) Walp) grown in certain acid, Alrich soils resulted from the poor survival of the potentially infective rhizobia. Two strains of Rhizobium capable of nodulating cowpeas were used. The lowest pH for growth in defined liquid medium was 4.2 for one strain and 3.9 for the other. Only the latter was Al tolerant and could grow in a defined liquid medium containing 50 ..mu..M KAl(SO/sub 4/)/sub 2/. The survival of the bacteria and their ability to nodulate cowpeas in three soils were measured after the soils were amended with Ca or Al salts to give pH values ranging from 5.7 to 4.1 and extractable-Al concentrations from < 0.1 to 3.7 cmol(p/sup +/)/kg of soil. Only small differences in survival in 7 or 8 weeks were noted between the two strains. Plants inoculated with the Al-sensitive strain bore significantly fewer nodules in the more acid, Al-rich soils than in the same soils with higher pH values and less extractable Al. No significant reduction in nodule number was evident for plants inoculated with the Al-tolerant strain and grown in the more acid, Al-rich soils compared to cowpeas grown in the same soils with higher pH values and less extractable Al. It is suggested that the Al content of soil is not a major factor in the survival of cowpea rhizobia but that it does have a significant effect on nodulation. 24 references, 3 figures, 2 tables.

  3. Multiplicity of Sulfate and Molybdate Transporters and Their Role in Nitrogen Fixation in Rhizobium leguminosarum bv. viciae Rlv3841.

    Cheng, Guojun; Karunakaran, Ramakrishnan; East, Alison K; Poole, Philip S

    2016-02-01

    Rhizobium leguminosarum Rlv3841 contains at least three sulfate transporters, i.e., SulABCD, SulP1 and SulP2, and a single molybdate transporter, ModABC. SulABCD is a high-affinity transporter whose mutation prevented growth on a limiting sulfate concentration, while SulP1 and SulP2 appear to be low-affinity sulfate transporters. ModABC is the sole high-affinity molybdate transport system and is essential for growth with NO3(-) as a nitrogen source on limiting levels of molybdate (<0.25 μM). However, at 2.5 μM molybdate, a quadruple mutant with all four transporters inactivated, had the longest lag phase on NO3(-), suggesting these systems all make some contribution to molybdate transport. Growth of Rlv3841 on limiting levels of sulfate increased sulB, sulP1, modB, and sulP2 expression 313.3-, 114.7-, 6.2-, and 4.0-fold, respectively, while molybdate starvation increased only modB expression (three- to 7.5-fold). When grown in high-sulfate but not low-sulfate medium, pea plants inoculated with LMB695 (modB) reduced acetylene at only 14% of the wild-type rate, and this was not further reduced in the quadruple mutant. Overall, while modB is crucial to nitrogen fixation at limiting molybdate levels in the presence of sulfate, there is an unidentified molybdate transporter also capable of sulfate transport. PMID:26812045

  4. Sources et bibliographie

    2015-01-01

    Sources manuscrites Archives nationales Il s’agit ici non pas d’un inventaire de tous les documents des Archives nationales concernant les dons et legs, mais d’une présentation des documents utilisés dans ce travail, et d’un tableau des grandes séries existantes. Série F3 : Administration communale F3 / II. Administration des communes. « Échange, concessions, partages des propriétés communales, dons et legs faits aux communes ». [Classement par département, et par communes à l’intérieur du dé...

  5. Conversion et conversation

    Mary, André

    2013-01-01

    Il est temps de faire le point sur l'apport théorique et empirique de l'oeuvre majeure de J. et J. Comaroff, Of Revelation and Revolution, dont deux tomes sont désormais parus (le troisième est en attente) et qui reste largement méconnue du public français. Cette anthropologie historique de l'évangélisme colonial est centrée sur la rencontre entre les missionnaires non-conformistes d'origine britannique et les Tswana d'Afrique du Sud. Le paradigme de l'interaction coloniale appliqué à ...

  6. Texte, Contexte et Connaissance

    Van Dijk, Teun A.

    2013-01-01

    Les structures situationnelles et sociétales ne peuvent pas affecter directement les processus mentaux de production et de compréhension des discours ; il faut un système mental médiateur, c’est-à-dire des modèles mentaux spécifiques (des modèles contextuels) qui représentent la “définition de la situation de communication” subjective des participants. Ces modèles mentaux contrôlent la production des structures et les dimensions du discours et s’assure que le discours est approprié à la situa...

  7. C. Petrone et al.: "Magnetic measurement of the model magnet QD0 designed for the CLIC final focus beam transport line." CERN TE-MSC Internal Note, EDMS Nr: 1184196

    Arpaia, Pasquale; Petrone, Carlo; Russenschuck, Stephan; Walckiers, Louis

    2012-01-01

    This note presents the results of the magnetic measurements performed on QD0, model magnet for the final focus transport line for CLIC (Fig. 1). This high-gradient, hybrid quadrupole has a yoke length of 0.1 m and an aperture of 8.3 mm. ND2Fe14B Permanent magnet blocks provide a gradient of 150 T/m, which can be further increased to 530 T/m when the four coils are excited to 18.3 A. The request was to measure the strength of the field and the multipole coefficients at different currents. The measurement of the field strength, by means of the single stretched wire system, was done in December 2011 in the I8 laboratory. The measurement of the multipole was done by means of the oscillating wire system [1][2].

  8. 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

    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

  9. Experimental Study of the Rhizobium and Iron Oxide Thiobacillus for Heap Leaching of Zinc Leaching Slag%根瘤菌与氧化铁硫杆菌堆浸锌浸出渣的试验研究

    李勇; 邓兴; 金开胜; 杨光棣

    2012-01-01

    This paper adopts the rhizobium and thiobaeillus ferrooxidans respectively for heap leaching processing of hydrometallurgy of zinc leaching residue. Through the treatment of rhizobium with thiobacillus ferrooxidans, zinc leaching residue of zinc leaching rate is compared. The test results indicate that rhizobium treatment of zinc leaching residue of zinc leaching rate reaches 24.12 % and thiobacillus ferrooxidans treatment of zinc leaching residue of zinc leaching rate reaches 33.86 %. Treatment rate by thiobacillus ferrooxidans was significantly higher than that of rhizobium.%本文采用根瘤菌与氧化铁硫杆菌分别堆浸处理湿法冶金的锌浸出渣,通过比较根瘤菌与氧化铁硫杆菌处理的锌浸出渣的锌浸出率。试验结果表明,根瘤菌处理锌浸出渣锌浸出率达到了24.12%,而氧化铁硫杆菌处理的锌浸出渣锌浸出率达到了33.86%,氧化铁硫杆菌处理锌浸出渣的锌浸出率明显高于根瘤菌。

  10. 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

    - 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.

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

    Vijn, I; Yang, W C; Pallisgård, N; Jensen, E O; van 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...... 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...

  12. Studies on the Alfalfa Growing Effects of Alfalfa Rhizobium%苜蓿根瘤菌剂对紫花苜蓿生长影响研究

    樊川; 杨旭升; 曹亚斌

    2015-01-01

    通过不同剂量苜蓿根瘤菌接种两种紫花苜蓿试验,比较了接种根瘤菌剂对紫花苜蓿生长的影响。试验结果表明:接种苜蓿根瘤菌剂能够提高紫花苜蓿结瘤数量和根瘤重,促进紫花苜蓿的生长发育,增加苜蓿草的产草量。在所试验的接种剂量中,以每 kg 苜蓿种子接种12mL 根瘤菌剂为最佳接种量。%This paper studied the alfalfa growing effects of alfalfa rhizobium by inoculated different amounts.The experimental results showed that inoculating rhizobium can raise the nodulating amount of alfalfa and the weight of nodulations,promoting the growth of alfalfas and augment the productions of alfalfas.Among the different inoculated amounts,the amount of 12ml is the best inoculated amount.

  13. Effect of aldicarb on growth and radio-carbon (14C) and radio-phosphorus (32P) assimilation by Rhizobium japonicum

    In vitro studies on the effect of aldicarb (2-methyl-2-(methyl thio) propionaldehde-o-methyl carbamoyl oxime), a soil applied systemic insecticide, on Rhizobium japonicum revealed that the chemical (at 1,2 and 5 ppm levels) stimulated the growth of the organism initially upto 48 hr which declined thereafter upto 72 hr. The incorporation of 14C-glucose by the cells considerably reduced due to the insecticide treatment. The production of extracellular, water-soluble slime (polysacchardes) was also reduced considerably with increased concentrations of the chemical. However, the incorporation of 14C-radio-activity in the extracellular slime generally enhanced due to the treatment, upto 6 hr after injection of the radioactivity, which declined significantly later at 15 hr, indicating a qualitative difference in the extracellular polysaccharides produced by the insecticide treated cells. The insecticide treatment drastically reduced the incorporation of 32P-disodium hydrogen phosphate into Rhizobium cells, but enhanced the specific activity of the extracellular polysacchrides. (author)

  14. Strigolactones in the Rhizobium-legume symbiosis: Stimulatory effect on bacterial surface motility and down-regulation of their levels in nodulated plants.

    Peláez-Vico, María A; Bernabéu-Roda, Lydia; Kohlen, Wouter; Soto, María J; López-Ráez, Juan A

    2016-04-01

    Strigolactones (SLs) are multifunctional molecules acting as modulators of plant responses under nutrient deficient conditions. One of the roles of SLs is to promote beneficial association with arbuscular mycorrhizal (AM) fungi belowground under such stress conditions, mainly phosphorus shortage. Recently, a role of SLs in the Rhizobium-legume symbiosis has been also described. While SLs' function in AM symbiosis is well established, their role in the Rhizobium-legume interaction is still emerging. Recently, SLs have been suggested to stimulate surface motility of rhizobia, opening the possibility that they could also act as molecular cues. The possible effect of SLs in the motility in the alfalfa symbiont Sinorhizobium meliloti was investigated, showing that the synthetic SL analogue GR24 stimulates swarming motility in S. meliloti in a dose-dependent manner. On the other hand, it is known that SL production is regulated by nutrient deficient conditions and by AM symbiosis. Using the model alfalfa-S. meliloti, the impact of phosphorus and nitrogen deficiency, as well as of nodulation on SL production was also assessed. The results showed that phosphorus starvation promoted SL biosynthesis, which was abolished by nitrogen deficiency. In addition, a negative effect of nodulation on SL levels was detected, suggesting a conserved mechanism of SL regulation upon symbiosis establishment. PMID:26940496

  15. Et dansk hotell

    Baca, Susan; Busck, Ole Gunni

    Rapporten præsenterer resultatet af en undersøgelse af, hvorledes et hotel i Nordjylland fungerer som arbejdsplads for indvandrere af overvejende ikke-vestlig oprindelse. Der fokuseres på i hvilket omfang og gennem hvilke mekanismer arbejdsmiljjøet i bred forstand, herunder forhold i ledelsen...

  16. Tabac et maladie parodontale

    Geerts, Sabine

    1996-01-01

    Le tabac est un facteur aggravant la parodontite. Beaucoup d'études cliniques ont été menées et ont souvent montré des résultats contradictoires. Cet article est une revue de littérature sur la relation entre le tabagisme et la parodontite. Peer reviewed

  17. Agronomies et agronomes

    Landais, Étienne; Boulier, Fabien; Robin, Paul

    2013-01-01

    L’agronomie française vit probablement un moment très important pour son avenir et connaît de profondes mutations. Ainsi, le pôle d’enseignement supérieur et de recherche de Montpellier, héritier d’une longue tradition et fort de sa dimension internationale méditerranéenne et tropicale, se réorganise. La création d’une « Faculté agronomique » est prévue en 2006. La concentration remarquable d’unités de recherche, dont beaucoup sont mixtes, dessine un espace scientifique et technique original ...

  18. Cartographie et intelligence artificielle

    Denise Pumain

    2005-11-01

    Full Text Available 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...

  19. Musique et document sonore

    Javault, Patrick

    2013-01-01

    Tirée d'une thèse en musicologie et en esthétique, cette enquête est d'abord remarquable par sa façon d'établir des regroupements et de définir son chemin de réflexion. Pierre-Yves Macé, lui-même musicien, compositeur et praticien des archives phonographiques, trouve des transversales pour éclairer l'emploi du document sonore dans les musiques savantes et expérimentales (en écartant sciemment la pop) - document sonore envisagé comme Autre du musical et qui peut également être dit « le réel de...

  20. Aristote et Pascal

    Michon, Hélène

    2016-01-01

    La seule mention qui est faite d’Aristote dans les Pensées est celle du fragment 457 : On ne s’imagine Platon et Aristote qu’avec de grandes robes de pédants. C’étaient des gens honnêtes et comme les autres, riants avec leurs amis. Et quand ils se sont divertis à faire leurs Lois et leurs Politiques, ils l’ont fait en se jouant. (fr. 457) Occurrence qui nous laisse à penser que si Pascal avait dû intervenir dans la querelle entre les Anciens et les Modernes, il l’eût certainement fait en épo...

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

    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. Entre terre et territoire

    Pirinoli, Christine

    2003-01-01

    La mémoire collective et les identités palestiniennes se (re)produisent à partir des référents symboliques centraux que sont la terre villageoise, le territoire, la nation et le transnational. Avec la perspective de la création d'un État palestinien, l'instrumentalisation, populaire et officielle, de ces notions rend particulièrement saillant le processus de réinterprétation qui est à l'oeuvre. Si ces concepts restent fondamentaux pour la majorité des Palestiniens, notamment en regard d...

  3. Biologie et histoire

    Froment, Alain

    1993-01-01

    L'article passe en revue les informations d'intérêt historique apportées par la biologie humaine ; on peut étudier les squelettes des populations disparues et en déduire des informations d'ordre démographique, nutritionnel ou médical et, indirectement, de nature socioéconomique. Sur les populations actuelles, la détermination des marqueurs génétiques (groupes sanguins ou autres) et, depuis peu, de l'ADN intracellulaire, permet de reconstituer les migrations anciennes. Enfin, sur le squelette ...

  4. Familles et immigration

    Streiff-Fénart, Jocelyne

    2004-01-01

    A l'ère de la mondialisation, le devenir encore incertain et variable selon les groupes de l'immigration familiale se noue dans les rapports complexes entre des redéfinitions identitaires qui se jouent sur la scène culturelle mondialisée, et l'intégration des descendants des immigrés dans l'ordre national, qui se joue sur le terrain socio-économique et politique de l'égalisation des chances.

  5. Abeilles sauvages et pollinisation

    Pfiffner, Lukas; Müller, Andreas

    2016-01-01

    La publication résume l’état actuel des connaissances scientifiques sur l’importance des abeilles sauvages dans la pollinisation des plantes sauvages et cultivées. Elle cite les causes actuellement connues du recul des abeilles sauvages, présente l’effet de l’agriculture biologique et propose une liste de mesures destinées à favoriser et à protéger ces pollinisateurs en plus de celles qui sont déjà appliquées.

  6. Musique et politique

    Albertini, Françoise; Bidart, Pierre; Capitolin, Jean-Louis; Cooper, Carolyn; Darré, Alain; Defrance, Yves; Dutertre, Jean-François; Guilbault, Jocelyne; Gumplowicz, Philippe; Hennion, Antoine; Herzhaft, Gérard; Leblon, Bernard; Liverpool, Hollis; Madiot, Béatrice; Maliesky, Dominique

    2015-01-01

    Musiciens et chanteurs sont à l'origine de pratiques qui s'insèrent pleinement dans le jeu complexe des rapports sociaux. Aux stades de la création, de la production ou de la consommation, les musiques n'échappent jamais aux enjeux socio-culturels d'un lieu, d'une époque, d'une communauté humaine. Conformes ou dissidentes à l'égard des logiques dominantes, elles demeurent productrices d'émotions esthétiques et porteuses des liens sociaux. Les musiques sont des enjeux de pouvoir et certaines l...

  7. Parler et convaincre

    Vigner, Gérard

    1979-01-01

    Dans l'apprentissage d'une langue, l'échange oral est avant tout utilitaire. On demande un renseignement, un prix, on salue, on remercie... On peut aussi parler pour exposer un point de vue, se justifier, entraîner une décision : parler pour convaincre. Cet ouvrage de la collection OUTILS veut aider les élèves à ce type d'intervention ; il leur fait d'abord analyser la situation de communication dans laquelle ils doivent intervenir, puis trouver les mots et expressions justes et efficaces. Sa structure et ses exercices permettent un travail tant collectif qu'individuel.

  8. ADN et chromosomes

    Hayes, Hélène

    2000-01-01

    Chaque chromosome contient une seule molécule d’ADN. L’ADN déroulé d’un noyau de cellule humaine mesurerait environ 1,8 m : chaque molécule d’ADN est enroulée et compactée en plusieurs étapes, grâce à l’association de différentes protéines, et loge dans le noyau de 6 µm de diamètre. Le degré de condensation de l’ADN est variable selon les régions chromosomiques et les régions les moins condensées sont les plus riches en gènes. L’ADN est composé d’une variété de séquences codantes ou non et ré...

  9. Algorithmes, machines et langages

    Berry, Gérard

    2014-01-01

    Enseignement : Le temps et les événements en informatique J’ai donné le cours « Le temps et les événements en informatique » dans le cadre de la chaire Algorithmes, machines et langages, créée le 4 juillet 2013 comme première chaire de plein exercice en informatique. J’avais introduit l’informatique au Collège de France en 2007-2008 par le cours « Pourquoi et comment le monde devient numérique », au sein de la chaire annuelle d’Innovation technologique Liliane Bettencourt, puis, en 2009-2010,...

  10. Jeunes et Musique

    Mauger, Gérard; Mignon, Patrick; Boyer, Régine; Hersent, Jean-François; Green, Anne-Marie; Daphy, Eliane

    1987-01-01

    Les Cahiers Jeunesses et sociétés sont une publication du Réseau « Jeunesses et Sociétés ». Le thème « Jeunes et Musiques » a été abordé dans le cadre des journées d'études du 26 juin 1986, 25 novembre 1986, et 26 mai 1987. Ce dixième numéro des Cahiers rend compte pour partie de ces travaux.SOMMAIRE• Présentation, par Gérard Mauger (1)• La production sociale du rock, par Patrick Mignon (3-32)• Les goûts musicaux des lycéens , par Régine Boyer (33-47)• Rock, jeunesse, socialisation. Jalons d'...

  11. Insight cognitif et schizophrenie

    W. El-Hage; Lafay, N.; Wassouf, I.; Jaafari, N.

    2011-01-01

    Resume La schizophrenie est souvent associee a une meconnaissance du trouble severe et persistante. Ce deficit d?insight est correle a l?hypofrontalite mais independant du pronostic de la maladie ou du quotient intellectuel. L?insight cognitif est defini comme la difference entre la capacite de reflexion sur soi et la certitude dans cette reflexion. Cette capacite est trouvee diminuee dans la schizophrenie mais augmentee en cas de depression. Ainsi, la schizophrenie avec comorbidit...

  12. 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

    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

  13. Entrepreneuriat Social et Participation Citoyenne

    Sophie Larivet

    2010-01-01

    Full Text Available L'entrepreneuriat social est un concept émergeant, notamment dans les sciences de l'administration. Pourtant, en dehors d'une pratique directoriale spécifique, il est aussi une forme de participation citoyenne trop méconnue. L'objectif de cet article, basé sur une revue de la littérature et une approche théorique, est de présenter le concept d'entrepreneuriat social afin de mieux saisir son positionnement par rapport à la participation citoyenne. L'entrepreneuriat social constitue une forme particulière de participation à l'espace public par l'action, les entreprises sociales agissant au quotidien pour transformer le paysage social. En particulier, cet article souligne le contexte de développement de l'entrepreneuriat social, définit le concept et les notions connexes d'entreprise sociale et d'entrepreneur social, et, enfin, présente une réflexion sur la contribution de l'entrepreneuriat social à la participation citoyenne. L'article montre que l'entrepreneuriat social est une façon pour les citoyens d'agir directement et avec maîtrise sur la société. / Social entrepreneurship is an emerging concept, notably in administrative sciences. However, not only is it a specific managerial practice but it is also a type of citizen participation that is not well-known. The objective of this article, based on a literature review and a theoretical approach, is to present the concept of social entrepreneurship in order to better understand its relation to citizen participation. Social entrepreneurship represents a specific type of citizen participation involving actions. Social enterprises act daily to transform the social landscape. More specifically, this article presents the context of development of social entrepreneurship, proposes a definition of the concept and of other connected notions like "social enterprise" and "social entrepreneur", and, finally, analyzes the contribution of social entrepreneurship to citizen participation. It

  14. Le beau et le vrai

    Létitia Mouze

    2006-05-01

    Full Text Available La vie des abeilles de Maeterlinck est un ouvrage à la fois scientifique et littéraire, non pas parce qu’il appartiendrait à la science par son exactitude et à la littérature par son style, mais en ce qu’il invite à penser l’unité des deux domaines. Les aspects littéraires de l’ouvrage (beauté de l’écriture, usage des images, de l’analogie, etc. ne sont pas des accessoires, mais des outils indispensables à l’élaboration d’un authentique savoir sur les abeilles, c’est-à-dire un savoir qui reconnaît la part d’inconnu et le mystère qui subsistent en dépit de toutes les explications physiques et mécaniques que l’on peut par ailleurs donner des phénomènes observés. Etre scientifique, dans cette perspective, c’est-à-dire donner à connaître, c’est donc être littéraire. Cette conception de la science repose en dernière instance sur une conception philosophique de l’univers comme un tout où toutes choses sont reliées, unies, par des relations d’analogies, ce qui fonde et justifie l’emploi d’un style symboliste.The life of bees, one of Maeterlinck’s works, is together a scientific and literary book, not because of it scientific exactness and its literary style, but for the reason it suggests the unity of both these domains. Literay’s aspects of this work (writing’s beauty, use of images, analogy, etc. are not secondary but necessary to elaborate an authentic knowledge about bees, that means a knowledge which admit the unknown part and the mistery that subsist despite all the physical and mechanical explanations we can give moreover about the observed phenomenons. Be a scientist, in this sense, that is give something to know, therefore means be literary. Finally, this conception of science consist in a philosophiacl conception of Universe as a whole where everything links together, and is united by analogical relations, that base and justify the use of a symbolist style.

  15. 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

    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

  16. La balle et la plume

    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...

  17. Enfants, chercheurs et citoyens

    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.

  18. NITROGEN FIXING EFFICIENCY OF SOME INDIGENOUS RHIZOBIUM LEGUMINOSARUM STRAINS ISOLATED FROM RED CLOVER (TRIFOLIUM PRATENSE, L. AND WHITE CLOVER (TRIFOLIUM REPENS, L. NODULES

    Andrei Stefan

    2014-10-01

    Full Text Available The increasing demand for food leads to intensive agricultural practices which require a high input of synthetic fertilizer. The excess fertilizer ends up in aquatic ecosystems, leading to eutrophication and hypoxia. An alternative would be the use of microorganisms capable of incorporating atmospheric nitrogen into organic compounds. Nitrogen fixing bacteria, collectively known as rhizobia, establish symbiosis with leguminous plants in exchange for a carbon source, this relationship being beneficial for both parties. Commercial rhizobial strains have been used as crop inoculants to improve biomass production but the commercial strains are not as adapted to pedo-climatic conditions as the local, indigenous strains. We tested the nitrogen fixing efficiency of some native Rhizobium leguminosarum strains from Romania, on biomass production of two clover species. Plants inoculated with the A2, R37 and R73 rhizobial strains showed the highest amount of biomass accumulation.

  19. Bacteriocin small of Rhizobium leguminosarum belongs to the class of N-acyl-L-homoserine lactone molecules, known as autoinducers and as quorum sensing co-transcription factors.

    Schripsema, J; de Rudder, K E; van Vliet, T B; Lankhorst, P P; de Vroom, E; Kijne, J W; van Brussel, A A

    1996-01-01

    Small bacteriocin was isolated from the culture broth of the gram-negative bacterium Rhizobium leguminosarum, which forms symbiotic nitrogen-fixing root nodules on a number of leguminous plants. The structure of the molecule was elucidated by spectroscopic methods and identified as N-(3R-hydroxy-7-cis-tetradecanoyl)-L-homoserine lactone. The absolute configuration of both asymmetric carbon atoms in the molecule was determined by the use of the chiral solvating agents S-(+)- and R-(-)-2,2,2-trifluoro-1-(9-anthryl)-ethanol. small bacteriocin is structurally related to the quorum sensing co-transcription factors for genes from other bacteria such as Vibrio fischeri, Pseudomonas aeruginosa, Erwinia carotovora, and Agrobacterium tumefaciens which are involved in animal-microbe or plant-microbe interactions. The mechanism of regulation of such interactions by this kind of co-transcription factors is still unknown in R. leguminosarum. PMID:8550454

  20. [Secretion of Phenolic Compounds into Root Exudates of Pea Seedlings upon Inoculation with Rhizobium leguminosarum bv. viceae or Pseudomonas siringae pv. Pisi].

    Makarova, L E; Dudareva, L V; Petrova, I G; Vasil'eva, G G

    2016-01-01

    The content of apigenin, naringenin, pisatin, dibutyl-ortho-phthalate, and N-phenyl-2-naphthyl-amine were assayed in root exudates of pea (Pisum sativum L.) seedlings one day after their inoculation with Rhizobium leguminosarum, bv. viceae or Pseudomonas siringae pv. pisi, which represent, respectively, mutualistic and antagonistic strategies of interaction with a host plant. After inoculation with either bacteria, the concentrations of apigenin and pisatin in the root exudates were equal, whereas the concentrations of naringenin and N-phenyl-2-naphthylamine were different and those of dibutyl-o-phthalate were unchanged. A certain role is suggested for the phenolic compounds in an accomplishment of symbiotic relations of bacteria with a host plant. PMID:27266251

  1. Co-inoculation with Rhizobium and plant growth promoting rhizobacteria (PGPR for inducing salinity tolerance in mung bean under field condition of semi arid climate

    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.

  2. Ultraviolet-irradiation induced and spontaneous mutation of Rhizobium trifolii 11B in relation to water-soluble and water-insoluble polysaccharide production ability

    Rhizobium trifolii 11B was u.v. irradiated and nine u.v. mutants have been isolated. Among the mutants, only one, R. trifolii 21M11B, produced more (752 mg/100 ml) water-soluble polysaccharide than the parent (704 mg/100 ml). The composition of water-soluble polysaccharide from u.v. mutants differed from that of the parent, R. trifolii 11B, and none of its u.v. mutants produced water-insoluble polysaccharide as detected by the Aniline Blue method. Storage of u.v. mutants for 2 months at 50C gave four spontaneous variants which acquired the ability to produce water-insoluble polysaccharide. The spontaneous mutants also retained their water-soluble polysaccharide producing ability. The water-soluble polysaccharide produced by these mutants was characterized as curdlan type. The chemistry of water-soluble and water-insoluble polysaccharides was also ascertained. (author)

  3. Traduction et corpus, corpus et recherche

    Williams, Geoffrey

    2011-01-01

    Dans l’enseignement des langues étrangères, la traduction est très souvent présente comme activité pédagogique. Dans les LEA de Lorient, nous ne prétendons pas former des traducteurs – notre spécialité reste le commerce international – mais en L3 une option rédaction/traduction a été ouverte pour ceux qui souhaitent se préparer à un Master en traduction ou rédaction. En plus de leurs cours de traduction, ces étudiants reçoivent des cours de lexicologie, de grammaire systémique et fonctionnell...

  4. Characterization of the temperate phage vB_RleM_PPF1 and its site-specific integration into the Rhizobium leguminosarum F1 genome.

    Halmillawewa, Anupama P; Restrepo-Córdoba, Marcela; Perry, Benjamin J; Yost, Christopher K; Hynes, Michael F

    2016-02-01

    Bacteriophages may play an important role in regulating population size and diversity of the root nodule symbiont Rhizobium leguminosarum, as well as participating in horizontal gene transfer. Although phages that infect this species have been isolated in the past, our knowledge of their molecular biology, and especially of genome composition, is extremely limited, and this lack of information impacts on the ability to assess phage population dynamics and limits potential agricultural applications of rhizobiophages. To help address this deficit in available sequence and biological information, the complete genome sequence of the Myoviridae temperate phage PPF1 that infects R. leguminosarum biovar viciae strain F1 was determined. The genome is 54,506 bp in length with an average G+C content of 61.9 %. The genome contains 94 putative open reading frames (ORFs) and 74.5 % of these predicted ORFs share homology at the protein level with previously reported sequences in the database. However, putative functions could only be assigned to 25.5 % (24 ORFs) of the predicted genes. PPF1 was capable of efficiently lysogenizing its rhizobial host R. leguminosarum F1. The site-specific recombination system of the phage targets an integration site that lies within a putative tRNA-Pro (CGG) gene in R. leguminosarum F1. Upon integration, the phage is capable of restoring the disrupted tRNA gene, owing to the 50 bp homologous sequence (att core region) it shares with its rhizobial host genome. Phage PPF1 is the first temperate phage infecting members of the genus Rhizobium for which a complete genome sequence, as well as other biological data such as the integration site, is available. PMID:26377943

  5. Seconde Intifada et terrorisme

    Garcin-Marrou, Isabelle; Tétu, Jean-François

    2003-01-01

    19 septembre 2002. Après environ un mois et demie d'accalmie (et la réoccupationquasi générale de la Cisjordanie par Tsahal), une attaque-suicide fait 5 morts à TelAviv. Le lendemain, soit environ deux ans après le début de la seconde Intifada,l'armée israélienne assiège de nouveau le QG de Yasser Arafat à Ramallah, auxtrois quarts détruit, et le gouvernement d'Israël, comme au printemps précédent,tente de le pousser à l'exil. Moins de 15 jours plus tôt, à peu près un an après lesattentats du...

  6. Contextualisation : stylistique et statistique

    Magri-Mourgues, Véronique

    2012-01-01

    La dimension du contexte des cooccurrences varie depuis le premier palier, celui du syntagme et de la phrase, à celui du corpus, observatoire construit par le chercheur, en passant par l’unité conventionnelle du paragraphe et l’unité textuelle déterminée par des propriétés de cohésion. La contextualisation permet d’établir les bases d’une stylistique différentielle où les opérations interprétatives de rapprochement et de différenciation s’exercent par rapport à un contexte préalablement défin...

  7. Zoos et cause animale

    Joulian, Frédéric; Abegg, Christophe

    2013-01-01

    Cet article, rédigé dans un contexte de débats sur les fonctions des zoos, a été repris et actualisé au regard des avancées du terrain et des réformes des zoos. Nous interrogeons les discours des zoos sur un aspect crucial, celui de leur légitimation de l’enfermement d’animaux sauvages, et cela en examinant les différents arguments avancés : conservation d’espèces rares, recherche scientifique, éducation du public. Nous discutons également la question de la réintroduction d’animaux en milieu ...

  8. Theories and calculation methods for regional objective ET (evapotranspiration): Applications

    LIU diaHong; QIN DaYong; WANG MingNa; L(U) JinYan; SANG XueFeng; ZHANG RuiMei

    2009-01-01

    The regional objective ET (evapotranspiration) is defined as the quantity of water that could be con-sumed in a particular region. It varies with the water conditions and economic development stages in the region. It is also constrained by the requirement of benign environment cycle. At the same time, it must meet the demands of sustainable economic growth and the construction of harmony society.Objective ET based water resources distribution will replace the conventional method, which empha-sizes the balance between the water demand and the water supply. It puts focus on the reasonable water consumption instead of the forecasted water demand, which is usually greater than the actual one. In this paper, we calculated the objective ET of 2010 year level in Tianjin by an analysis-integra-tion-assessment method. Objective ET can be classified into two parts: controllable ET and uncontrol-lable ET. Controllable ET includes the ET from irrigation land and the ET from resident land, among which the former can be calculated with soil moisture model and evapotranspiration model, while the latter can be calculated by water use ration and water consumption rate. The uncontrollable ET can be calculated with the distributed hydrological model and the remote sensing monitoring model. The two models can be mutually calibrated. In this paper, eight schemes are put forward based on different portfolios of water resources. The objective ET of each scheme was calculated and the results were assessed and analyzed. Finally, an optimal scheme was recommended.

  9. Dictionnaire et sens commun

    Sarfati, Georges Elia

    2009-01-01

    À partir d’une double réflexion sur le dictionnaire de langue et la notion de sens commun, le présent article tente d’esquisser une ligne de recherche nouvelle susceptible de contribuer au développement du domaine didactique. Il s’agit en effet de suggérer que, d’un point de vue énonciatif, des supports d’apprentissage tels que les différents corpus lexicographiques véhiculent, souvent à l’insu des enseignants et des apprenants, un certains nombre de schémas notionnels (culturels, idéologique...

  10. Monge et le parmesan

    Mattatia, Fabrice

    2009-01-01

    Le lecteur curieux qui ouvre les Annales de Chimie, ou recueil de mémoires concernant la chimie et les arts qui en dépendent, par les citoyens Guyton, Monge, Berthollet, Fourcroy, Adet, Hassenfratz, Séguin, Vauquelin, C.A. Prieur, Chaptal et Van Mons, 30 vendémiaire an VIII sera peut-être surpris d’y trouver une Notice sur la fabrication du fromage de Lodézan, connu sous le nom de Parmézan, par Gaspard Monge. Cette notice de huit pages prouve que Monge profita également de son séjour en Itali...

  11. Mafia et comportements mafieux

    Ghiloni, Jacques

    2011-01-01

    Dans le film Gomorra , consa-cré à la mafia napolitaine, on pouvait voir les rites initiatiques, la structuration hiérarchique et familiale du sous-prolétariat mafieux. On découvrait également les rapports d'intérêts qui reliaient la Camorra et l'économie capita-liste, au travers de l'enfouissement illégal des déchets industriels européens. Nous retrouvons dans ce numéro de la revue Illusio ces rites initiatiques, cette logique de domination, cette structuration familiale. Mais de manière plu...

  12. Stylistique et discours scientifique

    Gilles MATHIS

    2012-01-01

    Cette communication, après avoir présenté la pluralité des pratiques de la stylistique (étude de style, analyse de style, analyse rhétorique) en liaison avec les conceptions du style et dégagé les éléments fondamentaux de la caractérisation du discours scientifique, pose les conditions épistémologiques et méthodologiques d'une application spécifique de la stylistique à l'étude du discours scientifique. Elle en illustre la pratique par quelques exemples en annexe.

  13. Plastemballage i et recirkuleringsperspektiv

    Smith, Morten; Højfeldt Lund, Alexander Nicolas Jesper; Jensen, Bergliot Jeanne; Bertelsen, Kristine Dose

    2008-01-01

    Resume Nærværende opgave tager sit udgangspunkt William McDonough og Michael Braungarts Cradle to Cradle principperne. Cradle to Cradle er et nyt miljøparadigme på fremmarch med den centrale pointe at affald skal være lig føde. I opgaven fokuseres på Cradle to Cradles principper om recirkulering. Opgavens formål er at sætte disse generelle antagelser fra Cradle to Cradle ind i et virkelighedsperspektiv. Dette gøres ved hjælp af en case. Casen omhandler plastemballagefabrikanten Færch Plast...

  14. Hvad karakteriserer et talent?

    Raalskov, Jesper

    Debatten i medierne har i stigende grad fokus på talentfulde medarbejdere - men hvad er talent egentlig? I den akademiske litteratur inden for Talent Management (TM) gives der mange forskellige bud på, hvordan man som virksomhed kan udvikle og lede talenter, men færre af feltets inputgivere...... forholder sig til, hvad den overordnede definition af talent er. Der ses i litteraturen divergerende opfattelser af, hvilke konkrete egenskaber (attributter) som definerer et talent. I denne artikel gives et bud på en konsensusskabende tilgang til talent, idet talent kan ses som; det du har gjort (fortid...

  15. Cyberespace et cyberculture

    Pierre Lévy

    1999-01-01

    Alors, pendant la petite heure que va durer cette conférence, je voudrais partager avec vous quelques réflexions et quelques hypothèses sur la Cyberculture. Je voudrais d'abord situer les choses, mon propos est un propos de philosophe, autrement dit, il va s'agir de spéculations sur des concepts. Donc, je vous avertis tout de suite à quelle sauce vous allez être mangés. Il ne s'agit pas d'un discours culturel critique, comme les intellectuels français en ont l'habitude, et il ne s'agit pas no...

  16. Characterization and functional analysis of seven flagellin genes in Rhizobium leguminosarum bv. viciae. Characterization of R. leguminosarum flagellins

    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

  17. Aspects Technologiques et Developpementaspects Technologiques et Developpement

    Sebedio Jean-Louis

    2001-07-01

    Full Text Available L’acide linoléique conjugué (CLA est présent dans les aliments d’origine animale, en particulier ceux issus des ruminants. Le CLA peut aussi être synthétisé au laboratoire par isomérisation alcaline de l’acide linoléique. Alors que l’isomère naturel est le 18 : 2 9c,11t, les produits de synthèse contiennent principalement deux isomères, les 18 : 2 9c,11t et 10t,12c. De nombreuses études menées sur des modèles animaux, le plus souvent avec des mélanges synthétiques, montrent des effets potentiellement bénéfiques pour la santé (anticarcinogènes, protecteurs vis-à-vis de l’athérosclérose, modulateurs de la composition corporelle… alors que la plupart des études menées chez l’homme concernent les effets des CLA sur la composition corporelle. À ce jour, les données concernant les effets sur la composition corporelle chez l’homme semblent indiquer un bénéfice potentiel, mais les résultats restent controversés. Par ailleurs, bien qu’un effet anticarcinogène soit démontré chez l’animal, aucune étude chez l’homme n’a pu établir de relation entre CLA et cancer du sein. De plus, peu d’études traitant des aspects sécuritaires liés à la consommation à long terme ont été publiées. Par conséquent, il est nécessaire de disposer de plus de données en particulier chez l’Homme pour garantir l’innocuité de ces acides gras afin de protéger le consommateur, avant d’envisager l’utilisation de CLA dans des aliments fonctionnels.

  18. Ledelse i et interventionsperspektiv

    Keiding, Tina Bering

    2012-01-01

    Autopoetiske systemer er på det operative niveau lukkede for hinanden, hvilket betyder, at omverdenen eller andre systemer ikke kan gribe ind i et givent systems autopoiesis. Ledelse kan således ikke direkte specificere, det vil sige styre og kontrollere, de ledelsesudsatte systemers autopoiesis...

  19. Entre exotisme et nostalgie

    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

  20. 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

    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

  1. 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

    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 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 p

  2. 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

    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

  3. Final Report

    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.

  4. Final Report

    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.

  5. 接种耐酸根瘤菌对紫花苜蓿生长的影响%Effect of Acid-tolerant Rhizobium on the Growth of Alfalfa

    张媚佳; 徐淑韵; 徐苏凌; 方勇; 徐根娣

    2011-01-01

    The seeding of alfalfa on the acid soil with acid-tolerant rhizobium is to investigate the effects on the growth of alfalfa, and provide a theoretical and technical basis for the cultivation of alfalfa to the south. The results show that acid-tolerant rhizobium inoculation has promoted the growth of the 2 tested alfalfas, and there is breed difference of alfalfa when establishing symbiosis relationship with rhizobium.%为给南方紫花苜蓿的种植提供一定的理论和技术依据,采用土培法在酸性土壤上接种耐酸根瘤茵以探讨其对紫花苜蓿生长情况的影响.结果表明,接种耐酸根瘤菌对参试的2种紫花苜蓿生长都有促进作用,且紫花苜蓿在与根瘤菌建立共生关系时存在品种差异.

  6. Étude dans les états finals dileptoniques de différentes propriétés des paires top-antitop avec les détecteurs D0 et ATLAS; Study in the final states dileptoniques different properties of top-antitop pairs with D0 and ATLAS detectors

    Deterre, Cecile [Univ. Pierre et Marie Curie, Paris (France)

    2012-06-26

    Studies of different properties of the top-antitop pairs in dileptonique final state are presented in this thesis. Two analyzes were conducted in different experiments: one to D0 at the Tevatron, the other in ATLAS at LHC. Both colliders are different, the measures undertaken are complementary to the top of the properties of the study. The first analysis, conducted in the D0 experiment was to make simultaneous measurements of the cross section for production of pairs of top-antitop and branching ratio t -> Wb This was carried out in the channel with a dileptonique batch of data corresponding to a brightness of 5.4 fb⁻¹. It was then combined with the measurement made in the semileptonique channel to obtain an accuracy of 8% over the cross section, comparable to the accuracy of theoretical calculations. The second analysis presented, conducted in the ATLAS experiment was to measure the top quark charge asymmetry in dileptonique channel with the data set recorded by ATLAS in 2011, or 4.7 fb⁻¹. The results were then combined with the results of semileptonique channel obtained with 1 fb⁻¹. We measure: AC (ttbar) = 0.029 ± 0.018 (stat.) ± 0.014 (syst.), Which is compatible with the standard model prediction of 0.004 ±- 0.001.

  7. Terrorisme global et territoire

    Kastoryano, Riva

    2011-01-01

    Qu’il s’agisse du « régime de Terreur » de Robespierre, des attaques du 11 septembre 2001, des actions révolutionnaires nationalistes à la fin de l’empire ottoman ou de la lutte des « combattants de la liberté » contre les pouvoirs coloniaux, toute action caractérisée par la violence est qualifiée de « terroriste ». Le concept, vague et évolutif, est appliqué aux États, aux groupes et aux individus. Les États ont d’ailleurs chacun leur définition du mot, privilégiant leurs intérêts particulie...

  8. Suspicion et exception

    Bigo, Didier; Bonditti, Philippe; Bonelli, Laurent; GARCIA CASTRO, Antonia; Guild, Elspeth; Guittet, Emmanuel-Pierre; Perier, Miriam; Walker, R.B.J.

    2005-01-01

    Sur fond de "guerre globale au terrorisme", les doctrines de sécurité nationale se nourrissent des logiques de l'exception où la sécurité devient la valeur clé, reléguant ainsi la liberté et la justice à d'autres temps. Privilégiant une compréhension des politiques antiterroristes et de leurs effets sur la cohésion sociale, ce numéro apporte un éclairage renouvelé de ces "réponses" politiques qui conduisent, sous couvert d'une conception extensive de l'urgence, à faire de la suspicion une "ce...

  9. Elites judiciaires et culture

    Umbrecht, Véronique

    2012-01-01

    Les magistrats du Conseil souverain d’Alsace ont marqué leur appartenance à l’élite parlementaire française en se constituant de grandes bibliothèques privées. Oscillant entre une bibliothèque professionnelle et de loisirs, ces collections attestent de la forte imprégnation du français et affichent une évolution dans le choix des thématiques. Au cours du XVIIIe siècle, s’amorce un changement dans les pratiques de lecture. L’émergence de sociétés de lecture à Colmar dénote les besoins d’échang...

  10. Cyrano et les hydropotes

    Alain Mothu

    2007-10-01

    Full Text Available « Car il sera grand devant le Seigneur. Il ne boira ni vin, ni liqueur enivrante, et il sera rempli de l’Esprit-Saint dès le sein de sa mère »(Luc, I, 15Cyrano dédie sa lettre à la gloire de l’aqueduc d’Arcueil et des fontaines parisiennes qu’il alimentait, à « (ses amis les buveurs d’eau ». Cette dédicace abrite peut-être une fine allusion au fait que la construction de l’« acqueduc Médicis », entamée en 1612, fut financée en partie par un droit d’entrée à Paris imposé sur les vins, comme ...

  11. Cyrano et les hydropotes

    Alain Mothu

    2007-01-01

    « Car il sera grand devant le Seigneur. Il ne boira ni vin, ni liqueur enivrante, et il sera rempli de l’Esprit-Saint dès le sein de sa mère »(Luc, I, 15)Cyrano dédie sa lettre à la gloire de l’aqueduc d’Arcueil et des fontaines parisiennes qu’il alimentait, à « (s)es amis les buveurs d’eau ». Cette dédicace abrite peut-être une fine allusion au fait que la construction de l’« acqueduc Médicis », entamée en 1612, fut financée en partie par un droit d’entrée à Paris imposé sur les vins, comme ...

  12. Arpaillargues-et-Aureillac

    Pène, Jean-Michel

    2013-01-01

    Date de l'opération : 1998 (SU) Inventeur(s) : Pène Jean-Michel (SRA) Le site de Pré de Mières est implanté à proximité d'une importante source située au sud-est de la commune d'Arpaillargues-et-Aureillac. Il se trouve au pied des garrigues, sur un terrain relativement plat qui domine légèrement une petite dépression où s'écoule le ruisseau des Seynes (Fig. n°1 : Localisation du site (Arpaillargues-et-Aureillac, Pré de Mière)). Les vestiges archéologiques ont été mis au jour fin 1997, à l'oc...

  13. Globalisation et subjectivation politique

    Bayart, Jean-François

    2014-01-01

    Note portant sur l’auteur Je voudrais tout d’abord, pour clarifier un éventuel malentendu, préciser d’une part que je ne suis pas spécialiste des relations internationales ; mon approche est celle de la sociologie historique de l’État. D’autre part, je voudrais insister sur le fait que « globalisation » et « mondialisation » sont parfaitement synonymes. C’est important de le dire en raison du large débat qui a lieu en France à ce sujet et des sensibilités particulières qui s’expriment. Ces de...

  14. Musique et informatique

    Charnasse, Hélène

    1988-01-01

    Sommaire du numéro :http://archive-edutice.ccsd.cnrs.fr/edutice-00000838 Au sein des Sciences Humaines, la musique constitue un cas très particulier. D'une part, le langage musical peut se suffire à lui-même (c'est le cas des œuvres instrumentales). Ayant son vocabulaire et ses règles syntaxiques, il relève d'études de type sémiologique et linguistique. D'autre part, ce langage peut s'appuyer sur un support littéraire (cas des œuvres vocales). Ce support est alors justiciable d'une étude d...

  15. Musique, chansons et bruits

    Read, Peter

    2016-01-01

    Selon Louise Faure-Favier, « Apollinaire ne cachait pas son ignorance de l’art musical et qu’il ne l’intéressait que dans ses rapports avec la poésie. » Elle reconnaît, cependant, l’admiration qu’il portait à Erik Satie et le montre très ému par la musique de Schumann, jouée au piano par son ami Edgar Varèse. Selon Georges Auric, Apollinaire se souciait peu de la « grande musique », appréciait quelques lie- der de Schubert, mais avait « conservé longtemps le souvenir, pour lui ahurissant, d’u...

  16. Satan, Descartes et Kantorowicz

    Anheim, Étienne

    2013-01-01

    Comme dans beaucoup d’autres livres d’Alain Boureau, il règne dans Satan hérétique une atmosphère énigmatique, un air d’enquête policière ; une telle impression de lecture ne peut qu’éveiller la curiosité du lecteur, peu habitué à passer sans transition du Moyen Âge à Conan Doyle, et le pousser à comprendre son origine. Ce parfum d’étrangeté semble le fruit de principes de construction repris de livre en livre : le choix de sujets singuliers et apparemment ponctuels, tant dans la thématique q...

  17. Imprudence et impudence

    Thirouin, Laurent

    2016-01-01

    L’art polémique de Pascal dans Les Provinciales se caractérise, selon Jean Mesnard, par deux moyens rhétoriques : « l’expression directe d’une conviction forte », et l’ironie, « à la manière complète qui est celle de Platon ». Qu’est‑ce que cette ironie complète ? (je parlerais volontiers ici d’une ironie authentique, pour la distinguer de toutes les formes dégradées et dérivées, les plus communes, que l’on gratifie habituellement du nom d’ironie). J. Mesnard précise sa définition, en ébaucha...

  18. IFRS et PME

    Hossfeld, Christopher; Kajüter, Peter

    2008-01-01

    L'IASB est en train d'élaborer des normes comptables internationales (IFRS) pour les PME, basées sur les IFRS existantes. Or, les IFRS émises jusqu'à présent ciblent seulement les grandes entreprises (cotées) et leur situation. Par contre, le point de vue des PME en la matière a été très peu exploré. Pour cette raison, nous avons mené une enquête auprès de PME françaises et allemandes pour connaître dans un contexte comparatif entre pays les besoins des utilisateurs d'états financiers de PME,...

  19. Cyberespace et cyberculture

    Pierre Lévy

    1999-01-01

    Full Text Available Alors, pendant la petite heure que va durer cette conférence, je voudrais partager avec vous quelques réflexions et quelques hypothèses sur la Cyberculture. Je voudrais d'abord situer les choses, mon propos est un propos de philosophe, autrement dit, il va s'agir de spéculations sur des concepts. Donc, je vous avertis tout de suite à quelle sauce vous allez être mangés. Il ne s'agit pas d'un discours culturel critique, comme les intellectuels français en ont l'habitude, et il ne s'agit pas non plus de grandes prédictions sur le XXIème siècle, il s'agit vraiment d'une réflexion un peu approfondie sur des concepts.

  20. Et spil om overlevelse

    Teglhus, Hanne

    Vinterferiens arrangement i februar 2010 var et spil om overleve alverdens farlige sygdomme gennem tiden. Ved at kaste terninger kunne man se hvor stor ens chance var for overlevelse. Men i kraft at man kunne deltage i spillet må ens slægt have været både heldig og stærk, for ellers ville man ikk...

  1. Globalisation et finances internationales

    Prada B., Luis M.

    2011-01-01

    Cet article énonce les principales caractéristiques de la globalisation économique, il précise également en quoi consiste la globalisation financière et met en relief le rôle des investisseurs institutionnels dans les nouvelles finances. De même, l´article conclut que la globalisation financière offre de nouvelles opportunités ; à nous la responsabilité de les profiter.

  2. Incendies et pollutions

    Marlair, Guy

    1993-01-01

    Des sinistres recents ont montre que l'incendie ou encore les operations de lutte contre l'incendie pouvaient provoquer de graves degats à l'environnement (population, faune, flore,...). Parallelememt aux pertes economiques "classiques", les entreprises sinistrees voient souvent leur reputation entachee par les pollutions creees et qui peuvent affecter l'air, le sol, les eaux. Les industrieis, de leur propre fait ou sous la pression reglementaire s'interessent ä l'impact d'un eventuel sinistr...

  3. Candide et le physicien

    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...

  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

    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. 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

    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

  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

    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

  7. Anatomie et identification des bois

    Jourez, Benoît

    2010-01-01

    Anatomie des bois Structure anatomique des résineux et des feuillus Structure de la membrane cellulaire structure submicroscopique Anatomie du bois des essences feuillues tropicales Caractères anatomiques servant à l'identification des essences Reconnaissance microscopique du bois des essences résineuses et feuillues Duramen et duraminisation Formations anormales ( bois de compression et bois de tension) Chimie du bois Composition générale Cellulose, hé...

  8. Final Report

    Heiselberg, Per; Brohus, Henrik; Nielsen, Peter V.

    This final report for the Hybrid Ventilation Centre at Aalborg University describes the activities and research achievement in the project period from August 2001 to August 2006. The report summarises the work performed and the results achieved with reference to articles and reports published in...

  9. Capital social et anthroponomie

    Peaucelle, Irina

    2002-01-01

    Dans ce texte j'analyse les relations entre la composante Santé du capital social et la reproduction élargie de l'économie. Il s'agit aussi de discuter des méthodes d'évaluation de santé des populations pour apprécier leur potentiel de travail. En s'appuyant sur des travaux en psychologie sociale, je cherche à appréhender les rythmes anthroponomiques de l'évolution économique.

  10. Corpus et stylistique

    Magri-Mourgues, Véronique

    2007-01-01

    Une question lancée comme un défi a sous-tendu ce numéro de Corpus. Parallèlement aux linguistiques de corpus qui commencent à être clairement établies, serait-il envisageable de définir une stylistique de corpus ? Ou bien formulé autrement, que peut être un corpus pertinent en stylistique ? Quelles sont ses spécificités, si elles existent ? Articulant la problématique du corpus et l’analyse stylistique, les contributeurs explorent ce faisant des enjeux épistémologiques qui font envisager un ...

  11. Musique et holographie

    Vach, Holger

    2010-01-01

    Introduction L’holographie est surtout connue pour son rendu esthétique dans l’enregistrement d’images en trois dimensions. Cependant, dans le contexte des mesures scientifiques, elle joue souvent le rôle d’un instrument à la fois précis et simple d’emploi, par exemple pour les mesures de tout petits déplacements, ou de changements d’index de réfraction, ou bien d’amplitudes de vibration. Dans ce dernier cas, l’hologramme d’un objet en vibration présente l’objet en trois dimensions superposé ...

  12. Musique et pouvoirs

    Aubert, Laurent; Bois, Pierre; Borel, François; Brandily, Monique; CAUFRIEZ, Anne; Cheyronnaud, Jacques; Crowe, Peter; Desjacques, Alain; During, Jean; Erguner, Ahmed Kudsi; Helffer, Mireille; Howard, Keith; Leymarie, Isabelle; Lortat-Jacob, Bernard; Mesnil, Marianne

    2015-01-01

    Selon une croyance quasi universelle, certaines musiques sont investies de pouvoirs, d'où leur efficacité dans des rites permettant à l'individu ou à la collectivité de communiquer avec le monde invisible. D'autres musiques sont porteuses de messages subliminaux et d'effets, dans la mesure où leurs formes sont adaptées à leur finalité. Ainsi, l'usage de la musique à des fins politiques est fréquent, en tant que signe du pouvoir ou que de véhicule de sa propagation. Cette relation peut d'aille...

  13. Sources et bibliographie

    2015-01-01

    SOURCES Sources Archivistiques Archives nationales (AN) Série AP. Archives personnelles et familiales AP/09. Fonds privés d’avocats. 304/ AP. Maurice Garçon. 334/AP. Bluet. 417/AP. Georges Coulon. 470/AP. Alexandre Millerand. 476/AP. Chauveau- Lagarde. 488/AP. Joseph Denaïs. 505/AP. Edgar Faure. 516/AP. Bourdeau de Fontenay. 556/AP. Gabriel Olivier. 596/AP. Georges Calzant. Série BB. Ministère de la Justice BB29 : Enregistrement général de la correspondance BB29/723-724. Matricule des avoués ...

  14. Paroles et images

    Vidal, Martine; Wallet, Jacques

    2014-01-01

    Préambule Les questions posées par les formes contemporaines d’environnements d’apprentissages sont pour partie nouvelles, car (se) reposant sur les « nouvelles technologies », mais pour partie anciennes, car véhiculant le but (ou le mythe) d’une pédagogie nouvelle, dont les fondements prennent racine chez Platon, Rousseau, Freinet et bien d’autres. Mais les questions posées par les formes contemporaines d’environnements d’apprentissages ne sont pas que pédagogiques, elles s’inscrivent dans l...

  15. 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.

    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

  16. 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

    Gabriel Aranda-Selverio

    2010-01-01

    Full Text Available 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 these 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.

  17. 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

    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

  18. Détermination expérimentale des isothermes de sorption et de la chaleur isostérique des feuilles d'absinthe et de menthe pouliot

    Lamharrar, Abdelkader; Kane, Cheikh Sidi Ethmane; Idlimam, Ali; Akkad, Siham; Kouhila, Mohammed; Mimet, Abdelaziz; Ahachad, Mohamed

    2007-01-01

    International audience La détermination des isothermes de sorption est une étape indispensable et un moyen privilégié pour connaitre la répartition et l'intensité des liaisons de l'eau dans les produits agro-alimentaires. Ces isothermes permettent de déterminer la teneur en eau finale à atteindre pour optimiser les conditions de stockage et de séchage de ces produits et donnent des informations précieuses sur l'équilibre hygroscopique du produit à sécher et à conserver. Cette étude vise d'...

  19. Bouvard et Pécuchet et le désir amoureux

    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.

  20. Musique et genre en sociologie

    Prévost-Thomas, Cécile; Ravet, Hyacinthe

    2009-01-01

    Cet article recense et présente brièvement les recherches et publications sociologiques francophones les plus récentes consacrées aux rapports entre genre et musique selon trois grandes thématiques : celle de la création musicale au féminin, celle de la condition des musiciennes, et celle de la voix des femmes qui, plus étoffée, est également abordée sous l’angle des disciplines anthropologique et musicologique. Chacune de ces thématiques est traversée par la question des enjeux symboliques d...

  1. Final Report

    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.

  2. Production and Metabolism of Indole Acetic Acid in Root Nodules and Symbiont (Rhizobium undicola Isolated from Root Nodule of Aquatic Medicinal Legume Neptunia oleracea Lour.

    Pallab Kumar Ghosh

    2015-01-01

    Full Text Available Indole acetic acid is a phytohormone which plays a vital role in plant growth and development. The purpose of this study was to shed some light on the production of IAA in roots, nodules, and symbionts of an aquatic legume Neptunia oleracea and its possible role in nodular symbiosis. The symbiont (N37 was isolated from nodules of this plant and identified as Rhizobium undicola based on biochemical characteristics, 16S rDNA sequence homology, and DNA-DNA hybridization results. The root nodules were found to contain more IAA and tryptophan than root; however, no detectable amount of IAA was found in root. The IAA metabolizing enzymes IAA oxidase, IAA peroxidase (E.C.1.11.1.7, and polyphenol oxidase (E.C.1.14.18.1 were higher in root than nodule but total phenol and IAA content were reversed. The strain N37 was found to produce copious amount of IAA in YEM broth medium with tryptophan and reached its stationary phase at 20 h. An enrichment of the medium with mannitol, ammonium sulphate, B12, and 4-hydroxybenzaldehyde was found to promote the IAA production. The presence of IAA metabolizing enzymes and IAA production with PGPR traits including ACC deaminase activity of the symbionts was essential for plant microbe interaction and nodule function.

  3. Contribution of applied and soil phosphorus and sulphur in chickpea (Cicer arietinum L.) as influenced by Fe and Rhizobium inoculation in a Typic haplustept

    In an experiment with a test crop of chickpea during rabi, 1999-2000 the influence of P, S and Fe on the uptake of P and S was assessed using isotopic tracers (32P and 35S). It was found that the dry matter production increased by the application of phosphorus at 60 kg P2O5 ha-1 in both with and without Rhizobium inoculation and the combined application of P and Fe produced higher dry matter of both shoot and roots with inoculation. An assessment of the radioassay of applied phosphate and sulphate showed lower values of per cent derived from fertilizer in respect of both P and S. However, the values of phosphorus derived from fertilizer (Pdff) were comparatively higher due to combined application of P, S and Fe and those for sulphur due to phosphorus and sulphur only. The contribution of phosphorus from soil was more due to combined application of phosphorus and sulphur against the inoculation treatment, whereas, the contribution of phosphorus from fertilizer was observed to be improved due to applied phosphorus and iron along with the inoculation. Contribution of soil source for sulphur uptake increased with the application of sulphur along with iron or phosphorus both with and without inoculation. (author)

  4. The Aquaeous Extract of Root Nodules Vigna radiata (rnVr which Inoculated by Rhizobium as an Orally Available Anemia Therapeutic Candidate

    Dewi Hidayati

    2015-11-01

    Full Text Available The extract of root nodules Vigna radiata (rnVr which inoculated by Rhizobium is considered beneficial as an orally available anemia therapeutic candidate, because it contain the leghemoglobin. The positive control mice (group I were fed with the high nutrient pellet.The twelve mice (Mus musculus was treated with the “taking rice pellet” that representing the low nutrient food for 21 days until they suffered anemia. Then, the anemia mice were treated orally with rnVr in different concentration groups:II. 0% III.33%; IV.67% and V.100%, respectively and fed with the “aking rice pellet”. After 14 days, the blood mice were collected from orbital sinus. The hemoglobin (Hb concentration were analyzed by spectrophotometry and blood plasma profile protein were analyzed with electrophoresis (SDS-PAGE. All anemia mice that treated with rnVr showed the increasing of Hb and group that treated with 100% extract of rnVr could reach a normal Hb value, raising from 9.85 to 12.68 g/dL. There were observed the proteins which have molecule weight 36.5 and 35.7 kDa that indicated the existing erythropoietin. The increasing haemoglobin concentration and erythropoietin suggested if extract of rnVr could increasing red blood production and potential as an orally available anemia therapeutic candidate.

  5. 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.

    Supriya V Bhat

    Full Text Available 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.

  6. 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

    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.

  7. Formulation of microbes inoculum: AMF, PSB and Rhizobium isolated of ex-coal mining site for Acacia crassicarpa Cunn. Ex-benth seedlings

    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.

  8. 13N-nitrate uptake sites and rhizobium-infectible region in a single root of common bean [Phaseolus vulgaris] and soybean

    The positron emitting tracer-imaging system (PETIS) was used to determine whether it was possible to obtain on image of 13N distribution in common bean in which a single root was fed with a liquid medium containing nitrate at different concentrations with different 13N specific activities. The distribution of the images of the 13N atoms in the root could be obtained over a wide range of nitrate concentrations and 13N specific activities in the medium. As for nitrate stress on leguminous root nodulation, the positional relationship between the nitrate uptake sites and root hair just elongating area, where rhizobia capably initiate their infection, was studied in common bean and soybean. PETIS gave direct evidence that single roots of both common bean and soybean showed one or two dense 13N-distribution areas after 2 min pulse-feeding of 13NO3(-). These areas remained stable over 30 min, and the first dense site, which was common in all the examined roots, extended over ca. 1 cm above the root apex. Microscopic observation revealed that this area covered both sites of rhizobium infection and of early nodule development in a common bean and soybean single root

  9. Bacteria-zinc co-localization implicates enhanced synthesis of cysteine-rich peptides in zinc detoxification when Brassica juncea is inoculated with Rhizobium leguminosarum.

    Adediran, Gbotemi A; Ngwenya, Bryne T; Mosselmans, J Frederick W; Heal, Kate V

    2016-01-01

    Some plant growth promoting bacteria (PGPB) are enigmatic in enhancing plant growth in the face of increased metal accumulation in plants. Since most PGPB colonize the plant root epidermis, we hypothesized that PGPB confer tolerance to metals through changes in speciation at the root epidermis. We employed a novel combination of fluorophore-based confocal laser scanning microscopic imaging and synchrotron based microscopic X-ray fluorescence mapping with X-ray absorption spectroscopy to characterize bacterial localization, zinc (Zn) distribution and speciation in the roots of Brassica juncea grown in Zn contaminated media (400 mg kg(-1) Zn) with the endophytic Pseudomonas brassicacearum and rhizospheric Rhizobium leguminosarum. PGPB enhanced epidermal Zn sequestration relative to PGBP-free controls while the extent of endophytic accumulation depended on the colonization mode of each PGBP. Increased root accumulation of Zn and increased tolerance to Zn was associated predominantly with R. leguminosarum and was likely due to the coordination of Zn with cysteine-rich peptides in the root endodermis, suggesting enhanced synthesis of phytochelatins or glutathione. Our mechanistic model of enhanced Zn accumulation and detoxification in plants inoculated with R. leguminosarum has particular relevance to PGPB enhanced phytoremediation of soils contaminated through mining and oxidation of sulphur-bearing Zn minerals or engineered nanomaterials such as ZnS. PMID:26263508

  10. UV-radiation induced changes in antibiotic markers, chemical composition of water soluble polysaccharides and nodulation ability of Rhizobium trifolic 11B

    Rhizobium trifolii 11B, which formed effective nodules on its host. Trifolium alexanderinum L. was UV-irradiated to isolate mutants. Out of the 9 variants isolated only 1 strain, viz. 21M11B produced more water soluble polysaccharide [752 mg (100 ml-1)] than the parent 15 different antibiotics was similar only in two (22M11B and 26M11B) of the 9 UV-mutants. Compositional studies revealed that the water soluble polysaccharides from all strains contained glucose and galactose in the molar ratio of 7:1. Glucuronic acid which was present (2.33 per cent) in the water soluble polysaccharide from strain 11B was absent in all but 2UV-mutants (4.22per cent in 6M11B and 4.04per cent in26M11B). Five of the UB-mutants (1M11B, 17M11B, 20N11B, 22M11B and 26M11B) were Nod-. The organisms which produced more water soluble polysaccharide upon infection of the plants induced the formation of more number of nodules. (author)

  11. Complete genome sequence of Rhizobium leguminosarum bv trifolii strain WSM2304, an effective microsymbiont of the South American clover Trifolium polymorphum

    Reeve, Wayne [Murdoch University, Perth, Australia; O' Hara, Graham [Murdoch University, Perth, Australia; Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Ardley, Julie [Murdoch University, Perth, Australia; Brau, Lambert [Murdoch University, Perth, Australia; Nandesena, Kemanthi [Murdoch University, Perth, Australia; Tiwari, Ravi [Murdoch University, Perth, Australia; Malfatti, Stephanie [Lawrence Livermore National Laboratory (LLNL); Kiss, Hajnalka [Los Alamos National Laboratory (LANL); Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Melino, Vanessa [Murdoch University, Perth, Australia; Denton, Matthew [Department of Primary Industries, Victoria, Australia; Yates, Ron [Murdoch University, Perth, Australia; Howieson, John [Murdoch University, Perth, Australia

    2010-01-01

    Rhizobium leguminosarum bv trifolii is the effective nitrogen fixing microsymbiont of a diverse range of annual and perennial Trifolium (clover) species. Strain WSM2304 is an aerobic, motile, non-spore forming, Gram-negative rod, isolated from Trifolium polymorphum in Uruguay in 1998. This microsymbiont predominated in the perennial grasslands of Glencoe Research Station, in Uruguay, to competitively nodulate its host, and fix atmospheric nitrogen. Here we describe the basic features of WSM2304, together with the complete genome sequence, and annotation. This is the first completed genome sequence for a nitrogen fixing microsymbiont of a clover species from the American center of origin. We reveal that its genome size is 6,872,702 bp encoding 6,643 protein-coding genes and 62 RNA only encoding genes. This multipartite genome was found to contain 5 distinct replicons; a chromosome of size 4,537,948 bp and four circular plasmids of size 1,266,105 bp, 501,946 bp, 308,747 bp and 257,956 bp.

  12. Entre exotisme et nostalgie

    Caroline Rozenholc

    2009-01-01

    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 q...

  13. Crime, violence et ville

    Peralva, Angelina; Telles, Vera da Silva

    2014-01-01

    En mai 2006 São Paulo, capitale de l’État fédéré brésilien de même nom, s’est trouvée quasiment paralysée pendant cinq jours. Les commerces ont baissé le rideau, les piétons ont déserté les rues, les voitures et les transports collectifs ont cessé de circuler. Une ville fantôme au cœur d’une métropole de presque 20 millions d’habitants. A l’origine de ce phénomène, un ensemble d’actions violentes désignées par la presse comme « les attaques du PCC ». Le sigle évoque le « Primeiro Comando da C...

  14. Droit et travail

    Chambost, Isabelle; Dressen, Marnix; Maugeri, Salvatore; Touchelay, Béatrice

    2015-01-01

    Une des motivations de ce Corpus consacré aux rapports entre le droit et le travail renvoie assurément aux lois Auroux de 1982, dont on a célébré il y a peu le quarantième anniversaire. Ces lois garantissaient aux salariés de meilleurs droits ainsi qu’une plus grande capacité à accéder à des informations touchant à la marche de l’entreprise (notamment grâce au renforcement des prérogatives économiques des comités d’entreprise). On pouvait ainsi espérer l’inscription du droit du travail dans u...

  15. Vente directe et terroir

    Delfosse, Claire; Bernard, Cécile

    2009-01-01

    Si, dans la relation de proximité qu’établit la vente directe, il semble qu’il ne soit pas nécessaire de revendiquer le lien au terroir, il apparaît qu’aujourd’hui les nouvelles formes de vente directe et les formes « traditionnelles » renouvelées le font de plus en plus. Cela peut prendre différentes formes : revendication de la proximité, de la provenance « campagne », voire création de marques collectives faisant référence à un terroir ou un pays… Il s’agira donc dans cette communication d...

  16. Tourisme, patrimonialisation et politique

    Boullosa-Joly, Maïté

    2013-01-01

    La « Fête nationale de la Pachamama » qui se déroule dans le nord-ouest argentin à Amaicha, est un exemple de « co-constitution touristique et patrimoniale » [Lazzarotti, 2001] aux enjeux éminemment politiques. Nous montrons en effet comment la mise en scène d’une culture dans un projet de développement touristique a participé à ériger une croyance, celle en la Pachamama (la Mère Terre), pourtant commune au monde andin, en un « patrimoine culturel » singulier à ce village. Cette valorisation ...

  17. Serviers-et-Labaume

    Pène, Jean-Michel

    2013-01-01

    Date de l'opération : 1997 (PI) Inventeur(s) : Pène Jean-Michel (SDA) L’oppidum de Labaume I est implanté sur un promontoire du plateau du bois de Labaume. Il domine les petites gorges du ruisseau des Seynes et la plaine de Serviers (Fig. n°1 : Localisation de l’oppidum de Labaume I). Au cours des années 1980, le propriétaire, M. René Tournayre, fit effectuer des travaux mécaniques afin de niveler son terrain. Ces derniers ont eu pour conséquence de mettre au jour un très grand nombre de tém...

  18. LASER ET GLAUCOMES

    Sellem, E.-A.

    1987-01-01

    Très schématiquement, les glaucomes peuvent être définis comme des maladies ophtalmologiques dans lesquelles la pression intra-oculaire (PIO) est trop élevée, ce qui provoquera plus ou moins rapidement une destruction des fibres optiques et un risque de cécité. L'humeur aqueuse est directement responsable de la valeur de la PIO. Elle est sécrétée par le corps ciliaire, passe dans la chambre antérieure au travers de la pupille, pour être évacuée au niveau de l'angle irido-cornéen par le trabec...

  19. 6. Culture et science

    Schümperli Younossian, Catherine; Freyvogel, Thierry A.

    2012-01-01

    6.1. Réglementation du commerce de l’art en Suisse Au début des années 90, la Suisse est mise sous pression et accusée d’être le lieu de transit d’un commerce illégal de biens culturels étrangers. Pour sa part, le Conseil fédéral reconnaît le besoin de réglementation, constatant que la Suisse ne dispose pas, contrairement à d’autres pays européens, de lignes directrices réglant le contrôle du commerce illicite. Au niveau international, il existe deux conventions traitant de cette problématiq...

  20. Braille et la musique

    Ar Rouz, David

    2014-01-01

    La musique, universelle ? Voire ! Il n’est qu’à écouter une Suite pour violoncelle de Bach sur des enceintes fabriquées par un maître chinois, chanteur d’opéra, pour comprendre qu’à l’autre bout de la planète, ils n’entendent décidément pas comme nous : pour faire court, voire simpliste, ils aiment les sons « acides » quand nous avons tendance à chercher d’abord des basses rondes. Et combien de styles de musique, même sans aller chercher les pays les plus lointains, sommes-nous incapables d’a...

  1. Nietzsche et la musique

    Montebello, Pierre

    2005-01-01

    Pourquoi Nietzsche n'abandonna-t-il jamais Wagner même s'il se sépara de lui pour des motifs philosophiques ? On sait que la musique de Wagner a joué le rôle de scène originaire dans la formation d'une pensée qui chercha initialement à comprendre le monde au travers d'une métaphysique esthétique. Il faut ajouter que la musique wagnérienne, en dépit d'une teneur esthétique et dramatique de plus en plus éloignée de ce qu'attendait Nietzsche, fut intégrée dans le centre vivant de la pensée nietz...

  2. Genre, raison et nation

    Rada Ivekovic

    2009-01-01

    Full Text Available Ce travail s’intéresse aux mécanismes de sexuation et de subjectivation dans la construction de la nation. Quelques-uns ont postulé le “retard” de certains groupes sociaux par rapport à l’avènement de la “modernité”, concernant notamment les sujets extraeuropéens, mais aussi les femmes. En réalité, il n’y a pas de retard soit des femmes, soit des peuples colonisés en matière de modernité, parce que la norme de celle-ci est établie elle-même de façon arbitraire à partir d’une position de domination hégémonique depuis la modernité occidentale.

  3. Entre islam et islamisme

    El Ayadi, Mohammed

    2012-01-01

    Qu’elles soient publiques ou privées, les structures de l’enseignement religieux au Maroc sont multiples. La récente création de la direction de l’enseignement traditionnel au sein du ministère des Habous et des affaires islamiques (2004) vise à étendre le contrôle de l’État au réseau des lieux archaïques de l’apprentissage du savoir religieux traditionnel. Par ailleurs, les confréries religieuses connaissent aujourd’hui un certain développement, ainsi que d’autres structures privées de diffu...

  4. Pareto et Ernest Roguin

    Tappy, Denis

    2013-01-01

    Vie et œuvre d’Ernest Roguin Selon une recherche sur Internet, le plus récent ouvrage consacrant des développements substantiels à Ernest Roguin semble être une traduction en portugais, parue il y a quelques mois au Brésil, d’un livre du grand philosophe du droit italien Norberto Bobbio, récemment décédé. Il s’agit essentiellement d’une présentation de l’œuvre de Kelsen, qui s’achève cependant par un chapitre entier consacré au Vaudois, sous le titre révélateur de « Um theorico di direito esq...

  5. Monsieur Proust et la rumeur

    Manuel José Silva; Maria do Rosário Girão Ribeiro dos Santos

    2010-01-01

    Si la rumeur oscille entre la doxa et l’épistémè, tout en étant synonyme de discours rapporté, et si elle évolue dans un espace individuel et partagé où se consolident les pratiques sociales, la Recherche proustienne s’avère bel et bien le roman de l’archi-rumeur –susceptible de se diviser, selon notre typologie, en protorumeur(s) et en para-rumeur(s)–, filtrée par le point de vue central et unifiant du narrateur-protagoniste Marcel.If rumour oscillates between the doxa and the episteme, beco...

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

    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

  7. SIG, graphique et projet urbain

    Jacques AUTRAN

    1998-03-01

    Full Text Available L'avènement des SIG dans la formation aux métiers de l'aménagement de l'espace urbain remet au premier plan des questions de représentation et de sémiologie graphique. Les techniques informatiques nécessitent et permettent tout à la fois une meilleure formation à la sémiologie de la graphique et exigent son enrichissement.

  8. Former et apprendre à distance

    Simonian, Stéphane

    2013-01-01

    Les recherches actuelles sur les technologies de l’éducation peuvent se différencier en trois axes : le premier concerne l’appropriation des technologies par les professionnels de l’enseignement et de la formation, leurs usages et leurs conséquences en termes de compétences et de professionnalisation ; le deuxième axe concerne les questions d’apprentissage en termes d’habiletés atteintes et/ou de processus mis en œuvre par un apprenant ou un groupe d’apprenants ; le dernier axe, davantage « d...

  9. Flipped Learning fra et elevperspektiv

    Holmboe, Peter; Hachmann, Roland

    2016-01-01

    Antologi er et resultat af et toårigt udviklingsprojekt om Flipped Learning baseret på et samarbejde mellem IT-Center Fyn og Region Syddanmark. Bidraget her præsenterer en række overvejelser, vi har gjort os på baggrund af observationer af undervisning og interviews med elever i projektet. Vores...... overordnede undersøgelsesspørgsmål var: "Hvilke forhold i undervisning og læringsmiljø fremme hhv. begrænser elevens opfattelse af mening og fagligt udbytte i et Flipped Learning design?"....

  10. Musique et émotion

    Ciarcia, Gaetano; DeNora, Tia; Jouvenet, Morgan; De L'Estoile, Benoît; Maisonneuve, Sophie; Martin, Denis-Constant; Paradis, Annie; Roueff, Olivier; Segré, Gabriel; Seraïdari, Katerina; Wateau, Fabienne

    2005-01-01

    Loin de relever par excellence d'un ineffable résistant à toute analyse, voire à toute description, la musique est le fruit de pratiques et d'usages riches et complexes. C'est pourquoi les articles réunis ici n'appréhendent pas " la musique " en tant que phénomène universel dont il faudrait décrire les illustrations locales mais mettent en avant ses utilisations et leurs effets réels et, notamment, le rapport privilégié des pratiques musicales aux émotions.

  11. Glocalisation, runaway et local production

    Augros, Joël

    2012-01-01

    En matière de cinéma, coexistent plusieurs formes de relation entre marché local et marché international. Cet article focalise le regard sur deux de ces relations, autour du concept de glocalisation : la runaway production et la local production. Sont examinés les éléments historiques qui caractérisent ces formes de production cinématographique et leur situation actuelle. En écho aux articles de Joëlle Farchy et Jean Tardif (Questions de communication, 13, 2008), sont abordés ensuite les noti...

  12. Stockage dans les sols à charges variables et dissipation dans les eaux de zoocides organochlorés autrefois appliqués en bananeraies aux Antilles : relation avec les systèmes de culture : Recherche co-financée par le Programme 2003-2005 : “Évaluation et réduction des risques liés à l’utilisation des pesticides” du Ministère de l’Écologie et du Développement Durable (APR 2002). Rapport final d’exécution, mai 2006

    2006-01-01

    Des insecticides organochlorés (dieldrine, HCH, chlordécone) ont été appliqués dans les bananeraies des Antilles françaises des années 60 à 90. Les deux premiers sont rarement détectés dans les sols et les eaux. La chlordécone, très stable et hydrophobe, a été largement détectée depuis 1999 dans les eaux de source, puis dans les «racines» récoltées. L’analyse des sols de parcelles agricoles renseignées par des chroniques rétrospectives d’apports a permis de valider un modèle de dissipation d...

  13. Burlesque et pyrotechnie

    Le Forestier, Laurent

    2008-01-01

    Dans un court article écrit en 1924, Buster Keaton s'est essayé à une fantaisiste « histoire des films comiques », qui aurait débuté par « l'âge de l'explosion », avant de se poursuivre avec « l'âge du fromage blanc », « l'âge du policeman », « l'âge de l'automobile », « l'âge du costume de bain » et, enfin, « l'âge actuel ». Cette histoire commence avant la Première Guerre mondiale : évoquant « l'âge du fromage blanc », Keaton note avec ironie que le lancer de tartes à la crème a formé « d'e...

  14. Patpong, entre sexe et commerce.

    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

  15. Le vieillard et le chevalier

    Mélanie JECKER

    2010-05-01

    Full Text Available La fin du Moyen Âge fascine. Deux facteurs principaux expliquent l’attraction qu’exerce cette période : elle apparaît d’une part comme un moment historique riche car double, phase de transition entre le Moyen Âge et la Renaissance, où se mêlent des cadres de représentation anciens et nouveaux. L’insinuation d’une pensée humaniste balbutiante s’y traduirait notamment par l’émergence de la notion d’individu, qui constitue l’un des objets de ce travail. Il faut invoquer, d’autre part, l’image macabre d’un bas Moyen Âge hanté par l’idée de la maladie et de la mort depuis l’épidémie de peste noire de 1348, obsédé par la brièveté de la vie humaine. Ces deux facettes de « l’automne du Moyen Âge » tel que l’évoque avec poésie Joan Huizinga sont-elles autre chose qu’une plaisante image d’Epinal? Cette étude cherche précisément à déterminer le degré de validité de ces deux topiques, à travers l’analyse de la représentation des âges de la vie dans un corpus bien défini, celui de la biographie chevaleresque castillane du XVe siècle. L’intérêt porté à l’individu, la conscience de la singularité impliquent en effet celle du caractère mouvant de la personne, or quel thème mieux que celui des âges permet de confirmer ou d’infirmer l’hypothèse du surgissement d’une nouvelle manière de concevoir l’homme, proprement « renaissante », en ce siècle de transition , La nature même du corpus retenu – des récits biographiques – suggère en effet une mutation dans l’appréhension de la personne, une attention prêtée à sa progressive transformation. L’étude de la représentation de la vieillesse, en particulier, révèle non seulement à quel point était alors réelle cette prétendue obsession de la déchéance physique et de la mortalité, mais aussi dans quelle mesure étaient soulignés et valorisés les changements individuels parallèles à l

  16. Culture et droit processuel en Belgique

    de Leval, Georges; Georges, Frédéric

    2010-01-01

    Cet ouvrage regroupe le rapport de synthèse, les rapports généraux et les rapports nationaux relatifs aux quatre thèmes suivants : culture et droit civil, culture et droit international, culture et droit processuel et culture et droit des affaires

  17. Validación técnica de inoculantes en frijol con cepas de rhizobium eficientes en fijación de nitrógeno en Centroamérica

    Oscar Acu\\u00F1a; Emigdio Rodr\\u00EDguez; Aurelio Llano; Vilma Ruth Calder\\u00F3n; Guillermo Flores; Abelardo Viana; Rogelio L\\u00E9piz

    2001-01-01

    Se realizó un ensayo de validación técnica de inoculantes en frijol elaborado con cepas de Rhizobium eficientes en fijación biológica de nitrógeno, con el objetivo de recabar mayor información sobre la bondad de esta tecnología en la producción comercial de frijol. El ensayo regional se sembró en 45 sitios, distribuidos en Costa Rica (20), Panamá (10), Nicaragua (10) y El Salvador (5), durante 1998 y 1999. Se incluyeron cuatro tratamientos: 1. Testigo absoluto; 2. Inoc...

  18. Validación técnica de inoculantes en frijol con cepas de rhizobium eficientes en fijación de nitrógeno en Centroamérica

    Oscar Acuña; Emigdio Rodríguez; Aurelio Llano; Vilma Ruth Calderón; Guillermo Flores; Abelardo Viana; Rogelio Lépiz

    2001-01-01

    Se realizó un ensayo de validación técnica de inoculantes en frijol elaborado con cepas de Rhizobium eficientes en fijación biológica de nitrógeno, con el objetivo de recabar mayor información sobre la bondad de esta tecnología en la producción comercial de frijol. El ensayo regional se sembró en 45 sitios, distribuidos en Costa Rica (20), Panamá (10), Nicaragua (10) y El Salvador (5), durante 1998 y 1999. Se incluyeron cuatro tratamientos: 1. Testigo absoluto; 2. Inoculado; 3. Fertilización ...

  19. ET come home

    Fisher, J. B.; Whittaker, R. J.; Malhi, Y.

    2011-01-01

    Aim Many macroecological analyses are based on analyses of climatological data, within which evapotranspiration estimates are of central importance. In this paper we evaluate and review the use of evapotranspiration models and data in studies of geographical ecology to test the likely sensitivity...... evapotranspiration, outline basic evapotranspiration models and describe methods with which to measure evapotranspiration. Next, we compare three different types of potential evapotranspiration models – a temperature-based (Thornthwaite type), a radiation-based (Priestley–Taylor) and a combination (Penman......–Monteith) model – for 11 different land-cover types. Finally, we compare these models at continental and global scales. Results At some sites the models differ by less than 7%, but generally the difference was greater than 25% across most sites. The temperature-based model estimated 20–30% less than the radiation...

  20. Temps et musique en Chine

    Picard, François

    2008-01-01

    The practice of time in music is related to the people's conception of time. The case of China. La pratique des rythmes et des articulations en musique s'articule avec le temps vécu et conçu par les gens. Vu de la Chine.

  1. Investing EU ETS auction revenues into energy savings

    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.

  2. Functional analysis of NopM, a novel E3 ubiquitin ligase (NEL domain effector of Rhizobium sp. strain NGR234.

    Da-Wei Xin

    Full Text Available Type 3 effector proteins secreted via the bacterial type 3 secretion system (T3SS are not only virulence factors of pathogenic bacteria, but also influence symbiotic interactions between nitrogen-fixing nodule bacteria (rhizobia and leguminous host plants. In this study, we characterized NopM (nodulation outer protein M of Rhizobium sp. strain NGR234, which shows sequence similarities with novel E3 ubiquitin ligase (NEL domain effectors from the human pathogens Shigella flexneri and Salomonella enterica. NopM expressed in Escherichia coli, but not the non-functional mutant protein NopM-C338A, showed E3 ubiquitin ligase activity in vitro. In vivo, NopM, but not inactive NopM-C338A, promoted nodulation of the host plant Lablab purpureus by NGR234. When NopM was expressed in yeast, it inhibited mating pheromone signaling, a mitogen-activated protein (MAP kinase pathway. When expressed in the plant Nicotiana benthamiana, NopM inhibited one part of the plant's defense response, as shown by a reduced production of reactive oxygen species (ROS in response to the flagellin peptide flg22, whereas it stimulated another part, namely the induction of defense genes. In summary, our data indicate the potential for NopM as a functional NEL domain E3 ubiquitin ligase. Our findings that NopM dampened the flg22-induced ROS burst in N. benthamiana but promoted defense gene induction are consistent with the concept that pattern-triggered immunity is split in two separate signaling branches, one leading to ROS production and the other to defense gene induction.

  3. Functional analysis of the cysteine motifs in the ferredoxin-like protein FdxN of Rhizobium meliloti involved in symbiotic nitrogen fixation.

    Masepohl, B; Kutsche, M; Riedel, K U; Schmehl, M; Klipp, W; Pühler, A

    1992-05-01

    The Rhizobium meliloti fdxN gene, which is part of the nifA-nifB-fdxN operon, is absolutely required for symbiotic nitrogen fixation. The deduced sequence of the FdxN protein is characterized by two cysteine motifs typical of bacterial-type ferredoxins. The Fix-phenotype of an R. meliloti fdxN::[Tc] mutant could be rescued by the R. leguminosarum fdxN gene, whereas no complementation was observed with nif-associated genes encoding ferredoxins from Bradyrhizobium japonicum, Azotobacter vinelandii, A. chroococcum and Rhodobacter capsulatus. In addition to these heterologous genes, several R. meliloti fdxN mutant genes constructed by site-directed mutagenesis were analyzed. Not only a cysteine residue within the second cysteine motif (position 42), which is known to coordinate the Fe-S cluster in homologous proteins, but also a cysteine located down-stream of this motif (position 61), was found to be essential for the activity of the R. meliloti FdxN protein. Changing the amino acid residue proline in position 56 into methionine resulted in a FdxN mutant protein with decreased activity, whereas changes in positions 35 (Asp35Glu) and 45 (Gly45Glu) had no significant effect on the function of the FdxN mutant proteins. In contrast to bacterial-type ferredoxins, which contain two identical cysteine motifs of the form C-X2-C-X2-C-X3-C, nif-associated ferredoxins, including R. meliloti FdxN, are characterized by two different cysteine motifs. Six "additional" amino acids separate the second (Cys42) and the third cysteine (Cys51) in the C-terminal motif (C-X2-C-X8-C-X3-C).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1603075

  4. Screening a wide host-range, waste-water metagenomic library in tryptophan auxotrophs of Rhizobium leguminosarum and of Escherichia coli reveals different classes of cloned trp genes.

    Li, Youguo; Wexler, Margaret; Richardson, David J; Bond, Philip L; Johnston, Andrew W B

    2005-12-01

    A metagenomic cosmid library was constructed, in which the insert DNA was derived from bacteria in a waste-water treatment plant and the vector was the wide host-range cosmid pLAFR3. The library was screened for clones that could correct defined tryptophan auxotrophs of the alpha-proteobacterium Rhizobium leguminosarum and of Escherichia coli. A total of 26 different cosmids that corrected at least one trp mutant in one or both of these species were obtained. Several cosmids corrected the auxotrophy of one or more R. leguminosarum trp mutants, but not the corresponding mutants in E. coli. Conversely, one cosmid corrected trpA, B, C, D and E mutants of E. coli but none of the trp mutants of R. leguminosarum. Two of the Trp+ cosmids were examined in more detail. One contained a trp operon that resembled that of the pathogen Chlamydophila caviae, containing the unusual kynU gene, which specifies kynureninase. The other, whose trp genes functioned in R. leguminosarum but not in E. coli, contained trpDCFBA in an operon that is likely co-transcribed with five other genes, most of which had no known link with tryptophan synthesis. The sequences of these TRP proteins, and the products of nine other genes encoded by this cosmid, failed to affiliate them with any known bacterial lineage. For one metagenomic cosmid, lac reporter fusions confirmed that its cloned trp genes were transcribed in R. leguminosarum, but not in E. coli. Thus, rhizobia, with their many sigma-factors, may be well-suited hosts for metagenomic libraries, cloned in wide host-range vectors. PMID:16309391

  5. Rhizobium leguminosarum symbiovar trifolii, Ensifer numidicus and Mesorhizobium amorphae symbiovar ciceri (or Mesorhizobium loti) are new endosymbiotic bacteria of Lens culinaris Medik.

    Sami, Dhaoui; Mokhtar, Rejili; Peter, Mergaert; Mohamed, Mars

    2016-08-01

    A total of 142 rhizobial bacteria were isolated from root nodules of Lens culinaris Medik endemic to Tunisia and they belonged to the species Rhizobium leguminosarum, and for the first time to Ensifer and Mesorhizobium, genera never previously described as microsymbionts of lentil. Phenotypically, our results indicate that L. culinaris Medik strains showed heterogenic responses to the different phenotypic features and they effectively nodulated their original host. Based on the concatenation of the 16S rRNA with relevant housekeeping genes (glnA, recA, dnaK), rhizobia that nodulate lentil belonged almost exclusively to the known R. leguminosarum sv. viciae. Interestingly, R. leguminosarum sv. trifolii, Ensifer numidicus (10 isolates) and Mesorhizobium amorphae (or M. loti) (9 isolates) isolates species, not considered, up to now, as a natural symbiont of lentil are reported. The E. numidicus and M. amorphae (or M. loti) strains induced fixing nodules on Medicago sativa and Cicer arietinum host plants, respectively. Symbiotic gene phylogenies showed that the E. numidicus, new symbiont of lentil, markedly diverged from strains of R. leguminosarum, the usual symbionts of lentil, and converged to the symbiovar meliloti so far described within E. meliloti Indeed, the nodC and nodA genes from the M. amorphae showed more than 99% similarity with respect to those from M. mediterraneum, the common chickpea nodulating species, and would be included in the new infrasubspecific division named M. amorphae symbiovar ciceri, or to M. loti, related to the strains able to effectively nodulate C. arietinum host plant. On the basis of these data, R. leguminosarum sv. trifolii (type strain LBg3 (T)), M. loti or M. amorphae sv. ciceri (type strain LB4 (T)) and E. numidicus (type strain LBi2 (T)) are proposed as new symbionts of L. culinaris Medik. PMID:27267929

  6. Labeling of carbon pools in Bradyrhizobium japonicum and Rhizobium leguminosarum bv viciae bacteroids following incubation of intact nodules with 14CO2

    The aim of the work reported here was to ascertain that the patterns of labeling seen in isolated bacteroids also occurred in bacteroids in intact nodules and to observe early metabolic events following exposure of intact nodules to 14CO2. Intact nodules of soybean (Glycine max L. Merr. cv Ripley) inoculated with Bradyrhizobium japonicum USDA 110 and pea (Pisum sativum L. cv Progress 9) inoculated with Rhizobium leguminosarum by viciae isolate 128C53 were detached and immediately fed 14CO2 for 1 to 6 min. Bacteroids were purified from these nodules in 5 to 7 min after the feeding period. In the cytosol from both soybean and pea nodules, malate had the highest radioactivity, followed by citrate and aspartate. In peas, asparagine labeling equaled that of aspartate. In B. japonicum bacteroids, malate was the most rapidly labeled compound, and the rate of glutamate labeling was 67% of the rate of malate labeling. Aspartate and alanine were the next most rapidly labeled compounds. R. leguminosarum bacteroids had very low amounts of 14C and, after a 1-min feeding, malate contained 90% of the radioactivity in the organic acid fraction. Only a trace of activity was found in aspartate, whereas the rate of glutamate and alanine labeling approached that of malate after 6 min of feeding. Under the conditions studied, malate was the major form of labeled carbon supplied to both types of bacteroids. These results with intact nodules confirm our earlier results with isolated bacteroids, which showed that a significant proportion of provided labeled substrate, such as malate, is diverted to glutamate. This supports the conclusion that microaerobic conditions in nodules influence carbon metabolism in bacteroids. (author)

  7. Final Report

    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).

  8. Martyre et mort volontaire en Europe. : Entre religion et politique

    Albert, Jean-Pierre

    2007-01-01

    On tente ici de définir les ressorts à la fois religieux et politiques de l'acceptation altruiste de mourir pour une communauté. Les liens entre un tel devoir et une société holiste sont affirmés à partir d'une relecture de textes de Hobbes et de Durkheim, qui propose dans son célèbre ouvrage une définition souvent oubliée du « suicide altruiste ».

  9. Analyse de Langues et cultures - Les TIC, enseignement et apprentissage

    Élisabeth Brodin

    2006-04-01

    Full Text Available 1. Introduction Cet ouvrage constitue les actes du colloque des IUFM (Institut Universitaire de Formation des Maîtres de décembre 2003, intitulé "Quelles nouvelles perspectives pour l'enseignement / apprentissage des langues et cultures ?" On peut déplorer a priori que le titre du livre, au demeurant ambitieux, et le sous-titre ne reprennent pas la question des nouvelles perspectives apportées par les Technologies de l'Information et de la Communication (TIC à l'enseignement des langues e...

  10. At the sidelines of implementing the EU ETS: objections to ‘validity’

    Truxal, S.

    2010-01-01

    As the European Union's Emissions Trading Scheme (EU ETS) nears the final stages of implementation across Member States, it earns greater global recognition. An investigation into the ethos and status of the EU ETS raises interesting spaces to lead a sideline discussion on actual and likely objections by industries which emit greenhouse gases. It would appear that although the EU ETS is a model clean development mechanism under the Kyoto Protocol to the United Nations Framework Convention on ...

  11. Compost et digestat en Suisse

    Kupper, Thomas; Fuchs, Jacques

    2007-01-01

    Le rapport de synthèse propose une revue approfondie des micropolluants présents dans le compost, le digestat et l’eau de pressage et des bénéfices qu’apportent ces trois produits. Il décrit leurs effets sur l’environnement, sur la fertilité du sol, les organismes terrestres, ainsi que sur la santé des plantes. Les résultats de ces études exhaustives montrent que la grande majorité des composts et digestats de Suisse sont de qualité bonne à très bonne (échantillonnage 2003).

  12. Ressources humaines et territoires ruraux

    Dauty, Françoise; Tahar, Gabriel; Vernières, Michel

    2007-01-01

    Note Lirhe 440 (07-3) L'hypothèse centrale de ce travail collectif est que la dotation en ressources naturelles et même en capital physique des territoires ruraux n'apparaît pas comme le premier ressort de leur développement. Celui-ci est essentiellement fonction de leur capacité à innover socialement et économiquement, à mobiliser les ressources humaines dont ils disposent et à en attirer de nouvelles. L'impulsion initiale peut être issue d'entrepreneurs, d'associations ou d'autorités pol...

  13. Espace et musique en Chine

    Picard, François

    1998-01-01

    The notions of high and low are not such important in the Chinese way of making and writing music. The place, the space and the spatial relations are on the opposite quite important. Plutôt qu'explorer les notions de bas et de haut, qui n'occupent pas une place importante dans la conception ou la pratique chinoises de la musique, l'espace en tant que lieu établissant des relations entre musiciens et entre musiciens et auditeurs est examiné à travers diverses situations

  14. Intelligence Naturelle et Intelligence Artificielle

    DuBois, Daniel

    2011-01-01

    Cet article présente une approche systémique du concept d’intelligence naturelle en ayant pour objectif de créer une intelligence artificielle. Ainsi, l’intelligence naturelle, humaine et animale non-humaine, est une fonction composée de facultés permettant de connaître et de comprendre. De plus, l'intelligence naturelle reste indissociable de la structure, à savoir les organes du cerveau et du corps. La tentation est grande de doter les systèmes informatiques d’une intelligence artificielle ...

  15. Discours commerciaux et produits alimentaires

    Dupont, Louis

    2013-01-01

    Ce texte porte sur les discours commerciaux qui attribuent des valeurs culturelles à une gamme de produits, facilitant leur vente sur les marchés. C’est le cas des produits alimentaires sur lesquels porte ici l’analyse. Discours commercial et marketing ne doivent pas être confondus ; le marketing est en aval, les discours commerciaux, par leurs dimensions sociale et culturelle, sont en amont. Ils se donnent à lire et à voir sur l’emballage des produits, que l’on nomme « emballage discursif »....

  16.  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

    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.

  17. Définition des réseaux de surveillance DCE de la qualité des masses d’eau côtières de l’île de Mayotte - Rapport final Tome 1 Synthèse et propositions

    Turquet, Jean; Nicet, Jean Benoit; Cambert, Harold; Denis, Yves; Gonzalez, Jean-Louis; Bigot, Lionel; Guyomarch, Julien; Budzinski, Helene; Tapie, Nathalie; Jamon, Alban; Pribat, B

    2010-01-01

    Les prochaines échéances imposées par le calendrier de la Directive Cadre sur l’Eau sur les eaux côtières visent à atteindre ou à restaurer le bon état qualitatif et quantitatif de toutes les masses d’eau d'ici l'horizon 2015. Ces objectifs nécessitent la définition du bon état chimique des masses d’eaux, l’évaluation des tendances et la mise en place des programmes de mesures.

  18. 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

    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

  19. Consoer et al PFOS dataset

    U.S. Environmental Protection Agency — This ScienceHub entry was developed for the published paper: Consoer et al., 2016, Toxicokinetics of perfluorooctane sulfonate in rainow trout (Oncorhynchus...

  20. Le CERN et les Institutions

    Barbalat, Oscar

    1996-01-01

    Une première partie de l'exposéŽ sera consacrée àˆ une brève description des principaux organes de l'Union EuropéŽennne: Conseil, Parlement et Commission ainsi que la structure de la Commission. On passera ensuite en revue le Programme-Cadre de Recherche et DéŽveloppement Technologique et les principaux programmes spéŽcifiques auxquels participe le CERN (ESPRIT, ACTS, TMR) On situera ensuite les autres organisations et initiatives scientifiques européŽennes (ESA, ESO, ESRF, JET, ISTC, EUREKA, ...) pour terminer par une brève revue des relations entre le CERN avec ces difféŽrentes institutions en déŽveloppant plus particulièrement celles avec la Commission.

  1. Seltzer_et_al_2016

    U.S. Environmental Protection Agency — This dataset supports the modeling study of Seltzer et al. (2016) published in Atmospheric Environment. In this study, techniques typically used for future air...

  2. Épices et condiments

    M. Gast

    2012-01-01

    Les Berbères, traditionnellement grands consommateurs de lait et de viande, n’ont pas de plat spécifique qui donne lieu à des préparations élaborées faisant appel à des produits exotiques ; le couscous, les galettes, les bouillies ne donnent pas lieu à des recherches de goût et de saveur renouvelés, du moins chez les populations à régime économique pauvre. La faim endémique qui a sévi au cours des siècles parmi les populations nomades et rurales du Maghreb et du Sahara, n’a guère favorisé l’e...

  3. Voyage en train et paysage

    Bowie, Karen; Thom, René

    2011-01-01

    Karen Bowie a choisi le texte de cette communication du mathématicien et philosophe René Thom (1923-2002), prononcée lors du colloque « Arts et chemins de fer », 3e colloque de l’AHICF réuni en novembre 1993 dont les actes ont été publiés par la Revue d’histoire des chemins de fer 10-11 (1994), pour sa valeur de référence et d’actualité dans notre analyse des paysages créés par le chemin de fer. On voit ici que le paysage dessiné par l’infrastructure ferroviaire et celui créé par la vision du...

  4. Sonallah Ibrahim, Turbans et chapeaux

    Harzoune, Mustapha

    2013-01-01

    De l’expédition de Bonaparte en Égypte on ne retient que les quarante siècles qui, du haut des pyramides, contemplaient l’armée du général, l’armada de savants qui collait aux basques du Corse vindicatif, Champollion et ses hiéroglyphes et autre pierre de Rosette. En Égypte, comme ailleurs, la France prétendit apporter la civilisation et le bien-être au nom de l’universalisme et de l’amitié entre les peuples. Rien de nouveau sous le soleil… Mais voilà, les peuples qui ont eu le “privilège” de...

  5. An overview of current research on EU ETS: Evidence from its operating mechanism and economic effect

    The European Union Emissions Trading Scheme (EU ETS) is supposed to be an important mechanism for addressing climate change. Up to now, the theoretical foundation of EU ETS has been widely acknowledged, but empirical research on its current situation has only been published recently or is forthcoming. Therefore, this paper is aimed to summarize the main arguments of empirical studies on the EU ETS, in terms of two aspects, i.e., the operating mechanism and economic effect of the EU ETS, which are two crucial topics and have been attached much attention. Based on the shortcomings of current research and future requirements of the EU ETS evolution, finally, we also present some further directions of the EU ETS research. Overall, the research overview here may be helpful to recognize the features of the EU ETS and its effect on others. (author)

  6. Response to Brosch et al.

    Pihlajamäki, Jussi; Lerin, Carles; Kaminska, Dorota; Venesmaa, Sari; Itkonen, Paula; Boes, Tanner; Floss, Thomas; Schroeder, Joshua; Dearie, Farrell; Crunkhorn, Sarah; Burak, Furkan; Jimenez-Chillaron, Josep C.; Kuulasmaa, Tiina; Miettinen, Pekka; Park, Peter J.

    2012-01-01

    We would like to respond to Brosch et al. regarding our manuscript “Expression of the Splicing Factor Gene SFRS10 Is Reduced in Human Obesity and Contributes to Enhanced Lipogenesis” (Pihlajamäki et al., 2011b). Brosch performed RT-PCR in liver samples from 13 lean and 34 obese individuals, finding no differences in SFRS10 or LPIN1 expression. We wish to address points raised by Brosch, including experimental strategy and analysis of human SFRS10 expression.

  7. Et studie i alkoholismens psykologi

    Bonde, Lars Ole

    præsentation af operaen "Jeppe på Bjeget", som uropføres af Den jyske Opera på Viborg Teater 6.3. 2009. Artiklen er baseret på et interview med komponisten Bent Lorentzen.......præsentation af operaen "Jeppe på Bjeget", som uropføres af Den jyske Opera på Viborg Teater 6.3. 2009. Artiklen er baseret på et interview med komponisten Bent Lorentzen....

  8. Monsieur Proust et la rumeur

    Manuel José Silva

    2010-12-01

    Full Text Available Si la rumeur oscille entre la doxa et l’épistémè, tout en étant synonyme de discours rapporté, et si elle évolue dans un espace individuel et partagé où se consolident les pratiques sociales, la Recherche proustienne s’avère bel et bien le roman de l’archi-rumeur –susceptible de se diviser, selon notre typologie, en protorumeur(s et en para-rumeur(s–, filtrée par le point de vue central et unifiant du narrateur-protagoniste Marcel.If rumour oscillates between the doxa and the episteme, becoming itself synonymous with indirect speech, and if it evolves in an individual and shared space of consolidation of social practices, the Proustian Recherche stands unequivocally as the novel of arch rumour –liable to being subdivided, according to our typology, into protorumour(s and para-rumour(s–, filtered through the central and unifying viewpoint of the protagonist narrator Marcel.

  9. Diffusion et utilisation des TIC en France et en Europe

    Berret, Pierre; Chantepie, Philippe

    2015-01-01

    L’exploitation par le DEPS des enquêtes communautaires sur l’utilisation des TIC par les ménages et les particuliers, coordonnées, harmonisées et publiées par Eurostat, permet de dresser un portrait comparatif et en tendances de l’équipement en TIC, des modes d’accès à l’internet des ménages dans l’UE- 27 selon leurs caractéristiques socio-démographiques. Elle met en lumière l’intensification des usages numériques des particuliers, élucide les facteurs de développement des TIC que sont les us...

  10. Vêtement et textile : sources et ressources

    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...

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

    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.

  12. DYNAMIQUES DEMOGRAPHIQUES, DEGRADATION ENVIRONNEMENTALE ET RESTAURATION ECOLOGIQUE : ENJEUX ET OPPORTUNITES

    Leménager, Tiphaine; Bougnoux, Nathalie; Roques, Nicolas; Martin, Ceydric

    2014-01-01

    Dans un contexte alarmant d’érosion de la biodiversité, la restauration écologique est devenue un des objectifs fondamentaux de gestion des ressources naturelles des conventions internationales sur le sujet. L’engagement de divers pays dans des approches de restauration est par ailleurs croissant. Compte tenu du coût de la restauration écologique et des difficultés à restaurer, la question de chercher à préserver les écosystèmes, d’éviter leur dégradation et ainsi réduire les besoins futurs e...

  13. ETS-5, ETS-6, and COMETS projects in Japan

    Iida, Takashi; Wakana, Hiromitsu; Obara, Noriaki

    1992-08-01

    Three satellite communication projects now in progress in Japan are described. The first is a project to establish a telecommunication network for tele-education, TV conference, and tele-medicine in the Asia-Pacific region by using the Japan's Engineering Test Satellite-5 (ETS-5). The second is a project of the ETS-6 satellite, to be launched in 1993, for inter-satellite communication, mobile and fixed communication, and millimeter wave personal communication experiments. The third is a project of the Communications and Broadcasting Engineering Test Satellite (COMETS), to be launched in 1997, for advanced mobile satellite communication, inter-satellite link, and advanced broadcasting experiments at higher frequencies.

  14. Figures et oralité

    Rouayrenc, Catherine.

    2015-01-01

    L’oralité est co(n)textuelle et a pu varier selon son domaine d’emploi : ou bien, au début du xxe siècle, le dialogue seul, ce qui la faisait percevoir comme langage populaire, par opposition au langage littéraire de règle dans la narration, ou bien le dialogue et la narration. Les figures de l’oralité dans le roman sont d’une part des figures, morphologiques et syntaxiques, qui se caractérisent d’emblée comme orales, d’autre part des figures, les tropes notamment, dont l’oralité tient au cot...

  15. Chapitre VII. Culture et communication

    Depreux, Philippe

    2015-01-01

    Les divers degrés de perception du repas et la culture du boire en commun évoqués au chapitre précédent participent pleinement des modes de communication de cette époque. Il n’est pas certain que la distinction entre profane et sacré (ou religieux) soit à cet égard très opérante ; il existe toutefois divers niveaux de culture, qui ressortissent des traditions orales ou du savoir écrit. C’est dans le milieu savant qu’on observe au mieux la formation et l’expression d’identités culturelles dont...

  16. Agrochimie, Suisse et Tiers Monde

    Delucchi, Vittorio

    2013-01-01

    1. Situation générale Les deux catégories de produits chimiques les plus utilisées en agriculture sont les engrais et les pesticides [définition : voir HAYES, 1991]. La Suisse en a exporté en 1990 pour une valeur d’env. 796 millions de francs et importé pour une valeur d’env. 230 millions [ANONYME, 1991]. Le commerce extérieur de ces produits agrochimiques s’est surtout développé avec les pays de la Communauté Européenne (CE) et de l’Association Européenne de libre Echange (AELE), toutefois d...

  17. Les Mofu et leurs insectes

    Seignobos, Christian; Deguine, J.P.; Aberlenc, H.P.

    1996-01-01

    Les Mofu du Nord-Cameroun vivent, ou plutôt vivaient, avec les insectes. Ces derniers sont impliqués dans tous les aspects de leur vie : ils entrent dans l'alimentation et la pharmacopée, viennent en appui agronomique, servent d'augures et mêmes d'insectes de compagnie. Les Mofu, céréaliculteurs de montagne, ont valorisé le mil au point d'en faire l'objet d'une véritable religion. Ils opposent un registre d'insectes bénéfiques pour le mil à ceux qui sont maléfiques et aux ravageurs. Les premi...

  18. Régionalisation et mondialisation

    Fisbach, Erich

    2015-01-01

    Né au XXe siècle sous le signe du réalisme, de la dénonciation, de l’hétérogénéité des espaces et des réalités sociales, le roman adopte un point de vue régionaliste et des techniques narratives traditionnelles. Depuis les années 90, les équilibres régionaux se sont modifiés, la Bolivie est devenue un pays urbain, et l’irruption d’internet a contribué à mondialiser une littérature dont il s’agit de cerner les grandes lignes à travers l’analyse de quelques œuvres récentes....

  19. Le texte et ses composantes

    Adam, Jean-Michel

    2007-01-01

    L'énoncé, dans sa singularité, en dépit de son individualité et de sa créativité, ne saurait être considéré comme une combinaison absolument libre des formes de langue. (Bakhtine 1984 : 287) Le présent essai est une mise au point destinée à clarifier et ordonner certaines propositions de mes trois derniers ouvrages de linguistique pragmatique et textuelle. La théorie générale exposée dans Eléments de linguistique textuelle (Mardaga 1990) fixe un cadre sur lequel je ne reviendrai pas. Je me pr...

  20. Entre blogues et web diaries

    Lang, Marie-Ève

    2013-01-01

    Dans le cadre d’une recherche doctorale portant sur la façon dont les adolescentes et les jeunes femmes âgées de 17 à 21 ans utilisent le Web pour s’informer sur la sexualité, l’auteure présente la méthode qualitative qu’elle a élaborée et qui est basée sur l’activité du carnetage (blogging). Elle discute ici des caractéristiques particulières et des avantages d’une telle méthode. Drawing from her doctoral project on the uses of the Internet by teenage girls and young women between the age...