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Sample records for azorhizobium caulinodans ors571

  1. The genome of the versatile nitrogen fixer Azorhizobium caulinodans ORS571

    DEFF Research Database (Denmark)

    Lee, KB; De Backer, P; Aono, T;

    2008-01-01

    contents. Most nodulation functions as well as a putative type-IV secretion system are found in a distinct symbiosis region. The genome contains a plethora of regulatory and transporter genes and many functions possibly involved in contacting a host. It potentially encodes 4717 proteins of which 96.3% have......BACKGROUND: Biological nitrogen fixation is a prokaryotic process that plays an essential role in the global nitrogen cycle. Azorhizobium caulinodans ORS571 has the dual capacity to fix nitrogen both as free-living organism and in a symbiotic interaction with Sesbania rostrata. The host is a fast......-growing, submergence-tolerant tropical legume on which A. caulinodans can efficiently induce nodule formation on the root system and on adventitious rootlets located on the stem. RESULTS: The 5.37-Mb genome consists of a single circular chromosome with an overall average GC of 67% and numerous islands with varying GC...

  2. Cyanuric acid hydrolase from Azorhizobium caulinodans ORS 571: crystal structure and insights into a new class of Ser-Lys dyad proteins.

    Directory of Open Access Journals (Sweden)

    Seunghee Cho

    Full Text Available Cyanuric acid hydrolase (CAH catalyzes the hydrolytic ring-opening of cyanuric acid (2,4,6-trihydroxy-1,3,5-triazine, an intermediate in s-triazine bacterial degradation and a by-product from disinfection with trichloroisocyanuric acid. In the present study, an X-ray crystal structure of the CAH-barbituric acid inhibitor complex from Azorhizobium caulinodans ORS 571 has been determined at 2.7 Å resolution. The CAH protein fold consists of three structurally homologous domains forming a β-barrel-like structure with external α-helices that result in a three-fold symmetry, a dominant feature of the structure and active site that mirrors the three-fold symmetrical shape of the substrate cyanuric acid. The active site structure of CAH is similar to that of the recently determined AtzD with three pairs of active site Ser-Lys dyads. In order to determine the role of each Ser-Lys dyad in catalysis, a mutational study using a highly sensitive, enzyme-coupled assay was conducted. The 10⁹-fold loss of activity by the S226A mutant was at least ten times lower than that of the S79A and S333A mutants. In addition, bioinformatics analysis revealed the Ser226/Lys156 dyad as the only absolutely conserved dyad in the CAH/barbiturase family. These data suggest that Lys156 activates the Ser226 nucleophile which can then attack the substrate carbonyl. Our combination of structural, mutational, and bioinformatics analyses differentiates this study and provides experimental data for mechanistic insights into this unique protein family.

  3. Nucleotide sequence of the fixABC region of Azorhizobium caulinodans ORS571: similarity of the fixB product with eukaryotic flavoproteins, characterization of fixX, and identification of nifW.

    Science.gov (United States)

    Arigoni, F; Kaminski, P A; Hennecke, H; Elmerich, C

    1991-03-01

    The nucleotide sequence of a 4.1 kb DNA fragment containing the fixABC region of Azorhizobium caulinodans was established. The three gene products were very similar to the corresponding polypeptides of Rhizobium meliloti. The C-terminal domains of both fixB products displayed a high degree of similarity with the alpha-subunits of rat and human electron transfer flavoproteins, suggesting a role for the FixB protein in a redox reaction. Two open reading frames (ORF) were found downstream of fixC. The first ORF was identified as fixX on the basis of sequence homology with fixX from several Rhizobium and Bradyrhizobium strains. The second ORF potentially encoded a 69 amino acid product and was found to be homologous to a DNA region in the Rhodobacter capsulatus nif cluster I. Insertion mutagenesis of the A. caulinodans fixX gene conferred a Nif- phenotype to bacteria growth in the free-living state and a Fix- phenotype in symbiotic association with the host plant Sesbania rostrata. A crude extract from the fixX mutant had no nitrogenase activity. Furthermore, data presented in this paper also indicate that the previously identified nifO gene located upstream of fixA was probably a homologue of the nifW gene of Klebsiella pneumoniae and Azotobacter vinelandii. PMID:1850088

  4. Respiratory membrane endo-hydrogenase activity in the microaerophile Azorhizobium caulinodans is bidirectional.

    Directory of Open Access Journals (Sweden)

    Brittany N Sprecher

    Full Text Available BACKGROUND: The microaerophilic bacterium Azorhizobium caulinodans, when fixing N(2 both in pure cultures held at 20 µM dissolved O(2 tension and as endosymbiont of Sesbania rostrata legume nodules, employs a novel, respiratory-membrane endo-hydrogenase to oxidize and recycle endogenous H(2 produced by soluble Mo-dinitrogenase activity at the expense of O(2. METHODS AND FINDINGS: From a bioinformatic analysis, this endo-hydrogenase is a core (6 subunit version of (14 subunit NADH:ubiquinone oxidoreductase (respiratory complex I. In pure A. caulinodans liquid cultures, when O(2 levels are lowered to <1 µM dissolved O(2 tension (true microaerobic physiology, in vivo endo-hydrogenase activity reverses and continuously evolves H(2 at high rates. In essence, H(+ ions then supplement scarce O(2 as respiratory-membrane electron acceptor. Paradoxically, from thermodynamic considerations, such hydrogenic respiratory-membrane electron transfer need largely uncouple oxidative phosphorylation, required for growth of non-phototrophic aerobic bacteria, A. caulinodans included. CONCLUSIONS: A. caulinodans in vivo endo-hydrogenase catalytic activity is bidirectional. To our knowledge, this study is the first demonstration of hydrogenic respiratory-membrane electron transfer among aerobic (non-fermentative bacteria. When compared with O(2 tolerant hydrogenases in other organisms, A. caulinodans in vivo endo-hydrogenase mediated H(2 production rates (50,000 pmol 10(9·cells(-1 min(-1 are at least one-thousandfold higher. Conceivably, A. caulinodans respiratory-membrane hydrogenesis might initiate H(2 crossfeeding among spatially organized bacterial populations whose individual cells adopt distinct metabolic states in response to variant O(2 availability. Such organized, physiologically heterogeneous cell populations might benefit from augmented energy transduction and growth rates of the populations, considered as a whole.

  5. Regulation of Azorhizobium caulinodans ORS571 nitrogen fixation (nif/fix) genes.

    NARCIS (Netherlands)

    Stigter, J.

    1994-01-01

    Biological nitrogen fixation is the microbial process by which atmospheric dinitrogen (N 2 ) is reduced to ammonia. In all microbes studied, dinitrogen reduction is catalyzed by a highly conserved enzyme complex, called nitrogenase. The nitrogenase subunits and func

  6. Regulation of Azorhizobium caulinodans ORS571 nitrogen fixation (nif/fix) genes.

    OpenAIRE

    Stigter, J.

    1994-01-01

    Biological nitrogen fixation is the microbial process by which atmospheric dinitrogen (N 2 ) is reduced to ammonia. In all microbes studied, dinitrogen reduction is catalyzed by a highly conserved enzyme complex, called nitrogenase. The nitrogenase subunits and functions required for nitrogenase assembly and activity are encoded by the nitrogen fixation (nif/fix) genes.Nitrogen-fixing organisms can be roughly divided into two major groups: the free-living nitrogen fixing (diazotrophic) specie...

  7. Promotion for wheat growth and root colonization after infecting wheat seeds with Azorhizobium caulinodans%田菁茎瘤固氮根瘤菌对小麦种子侵染的促生作用及其在根系内的定殖

    Institute of Scientific and Technical Information of China (English)

    刘华伟; 孙超; 杨呼; 林晓军; 郭蔼光

    2012-01-01

    Common eight wheat cuhivars were selected and the sensitive cuhivars were screened out through gnoto- biotic condition test in the laboratory after infecting of the Azorhizobium caulinodans ORS571 (A. caulinodans) to wheat seeds. Infection method of seed soaking, the density of A. caulinodans and adding glucose are also studied, and the colonization of green fluorescence protein (GFP) - labeled A. caulinodans in the wheat seedling were detec- ted by fluorescence microscope. The results show that Xiaoyan22 is the most sensitive wheat cultivar to A. caulino- clans, in the gnotobiotic condition the root length and shoot height are increased by 17.04% and 8.37% respective- ly compared to the control, the optimum dilution proportion of A. caulinodans is 1.0 ×10^8/mL, and it is helpful for the infection to add 1 g/L glucose in A. caulinoclans PBS solution. With fluorescence microscope detection the result shows that GFP -labeled A. caulinodans infects from wheat seeding root hairs and lateral root fractures, and it can colonize in the vascular bundle of root. The field test shows that there is obvious promotion for wheat growth after infecting wheat cultivars seeds with A. caulinodans.%选取8个常见小麦品种,通过室内限菌试验筛选出对于田菁茎瘤固氮根瘤菌AzorhizobiumcaulinodansORS571(A.caulinodans)侵染响应敏感的品种,研究了浸种侵染、菌液浓度和添加葡萄糖对接菌小麦幼苗生长的影响,并结合荧光显微镜检测绿色荧光蛋白(GFP)标记A.caulinodans在小麦幼苗根系内的分布与定殖规律。结果表明:小偃22为响应敏感品种;在室内限菌条件下,浸种侵染小偃22幼苗平均根长和平均株高分别较对照增加了17.04%和8.37%;最适菌液浓度为1.0×10^8个/mL;在菌液中添加1g/L葡萄糖有助于A.caulinodans浸种侵染和定殖。荧光显微镜检测结果显示,GFP标记A.caulinodans从小麦幼苗根毛和侧根

  8. 田菁茎瘤固氮根瘤菌在小麦体内的定殖及营养元素相关miRNA的表达%Colonization of Azorhizobium caulinodans in wheat and nutrient-related miRNA expression

    Institute of Scientific and Technical Information of China (English)

    李强; 刘华伟; 王渭玲

    2014-01-01

    . 46 and 3. 99 fold of control. The relative peak expression of miR827 occurs at 24 h after inoculation, 2. 17 fold of the control. The expression of miR399 shows a trend of down-regulated first and then up-regulated. The relative expression of miR399 reaches the lowest point at 24 h after inoculation, equaling 0. 21 fold of the control. 3) Target prediction shows that the target genes of 6 miRNAs code NAC1 transcription factor, Auxin response factor, HAP transcription factor, Cu/Zn-superoxide dismutase, Ubiquitin-conjugating E2 enzyme PHO2 and SPX-MFS Subfamily protein respectively.[Conclusions]GFP-A. caulinodans can colonize in roots of wheat seedlings via root hairs and root tip breakages and ascend into the leaves around stomas. The relative expressions of N, P and microelements related miRNAs can be up-regulated through the inoculation of A. caulinodans. Healthy root morphology is constructed for more efficient uptake of nutrients.%【目的】随着化肥过度使用引起的环境问题的出现,无公害农业的推广,以及新型肥料研究领域不断拓宽,微生物肥料,尤其是植物根际促生菌的研究成为近年来的热点。然而微生物肥料的增产机理还基本停留在作物农学性状的表观调查上,没有从分子水平进行研究。因此,本文用田菁茎瘤固氮根瘤菌( Azorhizobium caulinodans ORS571)侵染小麦,探索GFP-A. caulinodans在小麦幼苗组织中的分布与定殖规律以及营养元素相关miRNAs在小麦与A. caulinodans互作中的作用机制。【方法】使用A. caulinodans侵染小麦种子(品种为小偃22),将接菌6 d后的小麦幼苗的根和接菌12 d 后的叶制作玻片,利用激光共聚焦显微镜对样品进行逐层扫描,检测 GFP-A. caulinodans在幼苗不同组织中的分布与定殖情况。同时,采集接菌后0 h、6 h、12 h、24 h、48 h、72 h、96 h的小麦幼根取样,用Trizol法提取总RNA。利用试剂盒进行加尾和反转录反应,将样品总RNA中的mi

  9. Development of Co-aggregated Cells as Bioinoculants Using Plant Seed Powders- A Novel Delivery System for Rice Grown under Lowland Condition

    Directory of Open Access Journals (Sweden)

    Palanivel Karpagavinayaga SIVAKUMAAR

    2008-12-01

    Full Text Available Co-aggregation was attempted in Azorhizobium caulinodans ORS-571 with other agriculturally important microorganisms such as Azospirillum brasilense MTCC-125, Azotobacter chroococcum MTCC-446, Bacillus megatherium MTCC-3353, and Pseudomonas fl uorescens MTCC-4828 to develop coaggregates with multiple benefi ts using seed powders of diff erent plants viz., Moringa oleifera, Strychnos potatorum and Sappindus emaignatus. Among the different treatments evaluated, the combination of Azorhizobium caulinodans ORS-571 and Azospirillum brasilense MTCC-125 with the plant seed powder of Moringa oleifera recorded the maximum co-aggregation of cells to the tune of 96.8%. The co-aggregates were also studied for their phyto-stimulatory effect such as seed vigour, plant height, plant dry weight, plant N content and endophytic colonization of A. caulinodans ORS-571 in rice var. ADT 43 grown under in vitro conditions. Th e co-aggregates of A. caulinodans and A. brasilense were found to be superior in positively augmenting the characters studied above.

  10. Sobrevivência de Bradyrhizobium e Azorhizobium em misturas de solo contaminadas com metais pesados

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    A. Matsuda

    2002-03-01

    Full Text Available Estudos foram realizados no Departamento de Ciência do Solo da Universidade Federal de Lavras (MG, no período de novembro/1999 a janeiro/2000, com o objetivo de avaliar a sobrevivência de estirpe e isolados de rizóbio em solo contaminado com metais pesados e verificar a relação entre tolerância do rizóbio a metais pesados em meio de cultura e sua sobrevivência em solo contaminado. Foram utilizados os dois microrganismos mais tolerantes [BR-4406 (estirpe recomendada para Enterolobium spp. e UFLA-01-457 (isolado de solo contaminado, ambos pertencentes ao gênero Bradyrhizobium ] e os dois mais sensíveis (UFLA-01-486 e UFLA-01-510, isolados de solo contaminado, pertencentes ao gênero Azorhizobium , todos selecionados de um grupo de 60estirpes/isolados em estudos prévios deste laboratório, em meio de cultura suplementado com metais pesados.Empregaram-se misturas de um Latossolo Vermelho-Escuro (LE que continham 0, 15 e 45% (v/v de um Latossolo Vermelho-Amarelo plíntico contaminado com Zn, Cd, Pb e Cu. As misturas de solo contaminado foram inoculadas com 20mL de cultura em YM na fase log das estirpes mencionadas, as quais foram testadas separadamente com três repetições. A avaliação do número de células viáveis no solo, realizada aos 0, 7, 14, 21 e 28dias de incubação, pelo método das diluições sucessivas e inoculação em placas com meio YMA, revelou comportamento diferenciado entre os organismos estudados. O número médio de células que sobreviveram ao final de 28 dias de incubação foi de (em UFCg-1de solo: 10(10,36, 10(10,29 e 10(9,70, para Bradyrhizobium, e 10(9,36, 10(7,54 e 0, para Azorhizobium em misturas de 0, 15 e 45% de solo contaminado, respectivamente. Portanto, houve maior sobrevivência de Bradyrhizobium do que de Azorhizobium , indicando maior tolerância a metais pesados do primeiro gênero.Como Bradyrhizobium foi também mais tolerante "in vitro", os resultados indicam haver relação entre o

  11. Functional nodFE genes are present in Sinorhizobium sp. strain MUS10, a symbiont of tropical legume Sesbania rostrata

    Science.gov (United States)

    Sinorhizobium sp. strain MUS10, a rhizobium from the Indian subcontinent, forms nitrogen-fixing nodules on the stems and roots of tropical legume Sesbania rostrata. The structure of Nod factors (NFs) of MUS10 are similar to those of Azorhizobium caulinodans, S. saheli bv sesbaniae and S. terangae bv...

  12. Inoculation two azotobacter enhancing osmotic stress resistance and growth in wheat seedling%接种两种固氮菌增强小麦幼苗抗渗透胁迫及生长能力

    Institute of Scientific and Technical Information of China (English)

    刘华伟; 林晓军; 孙超; 李强; 杨呼; 郭蔼光

    2013-01-01

    Aims The seedling stage is the key stage of matter and energy accumulation in the wheat life cycle. Therefore, drought during the seedling stage affects population formation in late stages. In this study, wheat seedlings were inoculated with azotobacters Azorhizobium caulinodans 'ORS571' and Azospirillum brasilense 'Yu62'. Methods Wheat seedlings germination was screened in normal conditions and with PEG 6000 osmotic stress using seedlings inoculated with azotobacters. Root volume, relative water content (RWC), proline content and soluble protein content of seedling laminas were determined under PEG drought stress using seedlings inoculated with azotobacters on laminas. Important findings The germination rate of wheat seedlings was significantly increased under drought stress when inoculated with azotobacters. Moreover, wheat seedlings inoculated with mixed azotobacters have more obvious growth promotion than when inoculated with a single azotobacter. The former laminas proline content, relative water content, proline content and soluble protein content had increased. The results showed that drought resistance of wheat seedlings was improved when inoculated with mixed azotobacters, which provided the foundation for further study of azotobacter-wheat interaction under drought stress.%苗期是小麦(Triticum aestivum)物质和能量积累的关键时期,苗期干旱影响小麦的后期群体建成.利用田菁茎瘤固氮根瘤菌(Azorhizobium caulinodans)‘ORS571’与巴西固氮螺菌(Azospirillum brasilense)‘Yu62’浸种侵染小麦和聚乙二醇(PEG)模拟渗透胁迫,研究渗透胁迫下接菌小麦种子的发芽状况;利用固氮菌涂抹小麦幼苗叶部,测定PEG模拟渗透胁迫下小麦幼苗根体积、叶片相对含水量、脯氨酸含量及可溶性蛋白含量,探究固氮菌增强小麦幼苗抗渗透胁迫的能力.结果表明,接种混合固氮菌后在渗透胁迫下小麦种子的发芽率明显提高;在渗透胁迫下叶部

  13. A novel endo-hydrogenase activity recycles hydrogen produced by nitrogen fixation.

    Directory of Open Access Journals (Sweden)

    Gordon Ng

    Full Text Available BACKGROUND: Nitrogen (N(2 fixation also yields hydrogen (H(2 at 1:1 stoichiometric amounts. In aerobic diazotrophic (able to grow on N(2 as sole N-source bacteria, orthodox respiratory hupSL-encoded hydrogenase activity, associated with the cell membrane but facing the periplasm (exo-hydrogenase, has nevertheless been presumed responsible for recycling such endogenous hydrogen. METHODS AND FINDINGS: As shown here, for Azorhizobium caulinodans diazotrophic cultures open to the atmosphere, exo-hydrogenase activity is of no consequence to hydrogen recycling. In a bioinformatic analysis, a novel seven-gene A. caulinodans hyq cluster encoding an integral-membrane, group-4, Ni,Fe-hydrogenase with homology to respiratory complex I (NADH: quinone dehydrogenase was identified. By analogy, Hyq hydrogenase is also integral to the cell membrane, but its active site faces the cytoplasm (endo-hydrogenase. An A. caulinodans in-frame hyq operon deletion mutant, constructed by "crossover PCR", showed markedly decreased growth rates in diazotrophic cultures; normal growth was restored with added ammonium--as expected of an H(2-recycling mutant phenotype. Using A. caulinodans hyq merodiploid strains expressing beta-glucuronidase as promoter-reporter, the hyq operon proved strongly and specifically induced in diazotrophic culture; as well, hyq operon induction required the NIFA transcriptional activator. Therefore, the hyq operon is constituent of the nif regulon. CONCLUSIONS: Representative of aerobic N(2-fixing and H(2-recycling alpha-proteobacteria, A. caulinodans possesses two respiratory Ni,Fe-hydrogenases: HupSL exo-hydrogenase activity drives exogenous H(2 respiration, and Hyq endo-hydrogenase activity recycles endogenous H(2, specifically that produced by N(2 fixation. To benefit human civilization, H(2 has generated considerable interest as potential renewable energy source as its makings are ubiquitous and its combustion yields no greenhouse gases. As

  14. Dicty_cDB: Contig-U00735-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available equence 11 from Patent WO03040681. 49 2e-04 CU207211_886( CU207211 |pid:none) Herminiimonas arsenicoxydans c..., clone: mib07054, 3' end, expre... 44 6.7 1 ( BG148484 ) uu79b10.y1 Soares_mouse_NMGB_bcell Mus musculus c....IK... 44 6.7 1 ( AA276535 ) vc44g11.r1 Soares mouse 3NbMS Mus musculus cDNA c... 44 6.7 1 ( AA184659 ) mt58d08.r1 Soares_thymus...ulfovibrio desulfuricans sub... 229 4e-59 AP010656_521( AP010656 |pid:none) Candidatus Azobacteroides pse..._1499( AP009384 |pid:none) Azorhizobium caulinodans ORS 57... 56 1e-06 BX640415_270( BX640415 |pid:none) Bordetella pertus

  15. Identification, sequencing and structural analysis of a nifA-like gene of Acetobacter diazotrophicus.

    Science.gov (United States)

    Teixeira, K R; Morgan, T; Meletzus, D; Galler, R; Baldani, J I; Kennedy, C

    1999-01-01

    A recombinant plasmid, pAD101, containing a DNA fragment of Acetobacter diazotrophicus strain PAL5 was isolated by its ability to restore Nif+ phenotype to a nifA- ntrC- double mutant of Azotobacter vinelandii. Hybridization with the nifA genes of Azospirillum brasilense located the nifA gene more precisely to specific fragments of pAD101. DNA sequencing of appropriate subclones of pAD101 revealed that the nifA gene was adjacent to the nifB gene in A. diazotrophicus, and the 5' end of the nifB gene was located downstream of the nitrogenase MoFe subunit gene, nifK. The deduced aminoacid sequence of A. diazotrophicus nifA and nifB gene were most similar to the NifA and NifB proteins of Azorhizobium caulinodans and Rhodobacter capsulatus, respectively. In addition, nucleotide sequences upstream of the A. diazotrophicus nifA-encoding region indicate features similar to those in the A. caulinodans nifA promoter region involved in O2 and fixed N regulation of nifA expression. PMID:10530336

  16. Sequence and structural organization of a nif A-like gene and part of a nifB-like gene of Herbaspirillum seropedicae strain Z78.

    Science.gov (United States)

    Souza, E M; Funayama, S; Rigo, L U; Yates, M G; Pedrosa, F O

    1991-07-01

    The deduced amino acid sequence derived from the sequence of a fragment of DNA from the free-living diazotroph Herbaspirillum seropedicae was aligned to the homologous protein sequences encoded by the nifA genes from Azorhizobium caulinodans, Rhizobium leguminosarum, Rhizobium meliloti and Klebsiella pneumoniae. High similarity was found in the central domain and in the C-terminal region. The H. seropedicae putative NifA sequence was also found to contain an interdomain linker similar to that conserved among rhizobial NifA proteins, but not K. pneumoniae or Azotobacter vinelandii. Analysis of the regulatory sequences found 5' from nifA indicated that the expression of this gene in H. seropedicae is likely to be controlled by NifA, NtrC and RpoN, as judged by the presence of specific NifA- and NtrC-binding sites and characteristic -24/-12 promoters. Possible additional regulatory features included an 'anaerobox' and a site for integration host factor. The N-terminus of another open reading frame was found 3' from nifA and tentatively identified as nifB by amino acid sequence comparison. The putative nifB promoter sequence suggests that expression of H. seropedicae nifB may be activated by NifA and dependent on RpoN. PMID:1840608

  17. Complete genome sequence of the facultatively chemolithoautotrophic and methylotrophic alpha Proteobacterium Starkeya novella type strain (ATCC 8093T)

    Energy Technology Data Exchange (ETDEWEB)

    Kappler, Ulrike [University of Queensland, The, Brisbane, Queensland, Australia; Davenport, Karen W. [Los Alamos National Laboratory (LANL); Beatson, Scott [University of Queensland, The, Brisbane, Queensland, Australia; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Berry, Kerrie W. [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

    2012-01-01

    Starkeya novella (Starkey 1934) Kelly et al. 2000 is a member of the family Xanthobacteraceae in the order Rhizobiales , which is thus far poorly characterized at the genome level. Cultures from this spe- cies are most interesting due to their facultatively chemolithoautotrophic lifestyle, which allows them to both consume carbon dioxide and to produce it. This feature makes S. novella an interesting model or- ganism for studying the genomic basis of regulatory networks required for the switch between con- sumption and production of carbon dioxide, a key component of the global carbon cycle. In addition, S. novella is of interest for its ability to grow on various inorganic sulfur compounds and several C1- compounds such as methanol. Besides Azorhizobium caulinodans, S. novella is only the second spe- cies in the family Xanthobacteraceae with a completely sequenced genome of a type strain. The cur- rent taxonomic classification of this group is in significant conflict with the 16S rRNA data. The ge- nomic data indicate that the physiological capabilities of the organism might have been underestimat- ed. The 4,765,023 bp long chromosome with its 4,511 protein-coding and 52 RNA genes was se- quenced as part of the DOE Joint Genome Institute Community Sequencing Program (CSP) 2008.

  18. Identification and characterization of the two-component NtrY/NtrX regulatory system in Azospirillum brasilense

    Directory of Open Access Journals (Sweden)

    M.L. Ishida

    2002-06-01

    Full Text Available Two Azospirillum brasilense open reading frames (ORFs exhibited homology with the two-component NtrY/NtrX regulatory system from Azorhizobium caulinodans. These A. brasilense ORFs, located downstream to the nifR3ntrBC operon, were isolated, sequenced and characterized. The present study suggests that ORF1 and ORF2 correspond to the A. brasilense ntrY and ntrX genes, respectively. The amino acid sequences of A. brasilense NtrY and NtrX proteins showed high similarity to sensor/kinase and regulatory proteins, respectively. Analysis of lacZ transcriptional fusions by the ß-galactosidase assay in Escherichia coli ntrC mutants showed that the NtrY/NtrX proteins failed to activate transcription of the nifA promoter of A. brasilense. The ntrYX operon complemented a nifR3ntrBC deletion mutant of A. brasilense for nitrate-dependent growth, suggesting a possible cross-talk between the NtrY/X and NtrB/C sensor/regulator pairs. Our data support the existence of another two-component regulatory system in A. brasilense, the NtrY/NtrX system, probably involved in the regulation of nitrate assimilation.

  19. Endophytic colonization of plant roots by nitrogen-fixing bacteria

    International Nuclear Information System (INIS)

    Nitrogen-fixing bacteria are able to enter into roots from the rhizosphere, particularly at the base of emerging lateral roots, between epidermal cells and through root hairs. In the rhizosphere growing root hairs play an important role in symbiotic recognition in legume crops. Nodulated legumes in endosymbiosis with rhizobia are amongst the most prominent nitrogen-fixing systems in agriculture. The inoculation of non-legumes, especially cereals, with various non-rhizobial diazotrophic bacteria has been undertaken with the expectation that they would establish themselves intercellularly within the root system, fixing nitrogen endophytic ally and providing combined nitrogen for enhanced crop production. However, in most instances bacteria colonize only the surface of the roots and remain vulnerable to competition from other rhizosphere micro-organisms, even when the nitrogen-fixing bacteria are endophytic, benefits to the plant may result from better uptake of soil nutrients rather than from endophytic nitrogen fixation. Azorhizobium caulinodans is known to enter the root system of cereals, other nonlegume crops and Arabidopsis, by intercellular invasion between epidermal cells and to internally colonize the plant intercellularly, including the xylem. This raises the possibility that xylem colonization might provide a nonnodular niche for endosymbiotic nitrogen fixation in rice, wheat, maize, sorghum and other non-legume crops. A particularly interesting, naturally occurring, non-qodular xylem colonising endophytic diazotrophic interaction with evidence for endophytic nitrogen fixation is that of Gluconacetobacter diazotrophicus in sugarcane. Could this beneficial endophytic colonization of sugarcane by G. diazotrophicus be extended to other members of the Gramineae, including the major cereals, and to other major non-legume crops of the World? (author)

  20. Bacterial dynamics during yearlong spontaneous fermentation for production of ngari, a dry fermented fish product of Northeast India.

    Science.gov (United States)

    Devi, Khunjamayum Romapati; Deka, Manab; Jeyaram, Kumaraswamy

    2015-04-16

    Azorhizobium caulinodans were detected throughout the fermentation. Principal component analysis showed a drastic bacterial community structural change at the sixth month of fermentation. These identified dominant bacterial cultures of T. halophilus, L. pobuzihii, S. carnosus and B. indicus could be effectively utilised for designing starter culture and optimizing fermentation technology for industrialisation of ngari production. PMID:25637876

  1. Sesbania virgata stimulates the occurrence of its microsymbiont in soils but does not inhibit microsymbionts of other species Sesbania virgata estimula a ocorrência de seu microssimbionte nos solos, mas não inibe os microssimbiontes de outras espécies

    OpenAIRE

    Ligiane Aparecida Florentino; Ana Paula Guimarães; Márcia Rufini; Krisle da Silva; Fátima Maria de Souza Moreira

    2009-01-01

    The legume species Sesbania virgata establishes a specific and efficient symbiosis with Azorhizobium doebereinerae. Previous studies have shown that A. doebereinerae occurrence correlates to the presence of S. virgata. This work aimed to evaluate the occurrence of A. doebereinerae and of other nitrogen-fixing Leguminosae-nodulating bacteria (NFLNB) in soil samples collected adjacent to and 10 m away from the stems of five S. virgata plants in pasture areas. Symbiotic characteristics of isolat...

  2. Dicty_cDB: Contig-U12134-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2e-54 CU207211_118( CU207211 |pid:none) Herminiimonas arsenicoxydans chr... 217 2e-54 ( P07991 ) RecName: Fu...ulfitobacterium hafniense DCB... 139 5e-31 AP009384_4028( AP009384 |pid:none) Azorhizobium cau...yyylfylclifhfyliflfhfylyl iflfhfcliflfhfylypiflfhfylyhlylfslslsplsesplddddelsflllslppp lplpllllllsssy*lvvlyv...4-1Q.Seq.d (2911 letters) Database: CSM 6905 sequences; 5,674,871 total letters Score E Sequences producing significa...7 bits (841), Expect = 0.0 Identities = 841/841 (100%) Strand = Plus / Plus Query: 939 taaattaccattggtaatatttggtttatcaccaatacca

  3. 77 FR 9633 - Army National Cemeteries Advisory Commission (ANCAC)

    Science.gov (United States)

    2012-02-17

    ... Department of the Army Army National Cemeteries Advisory Commission (ANCAC) AGENCY: Department of the Army... Army announces the following committee meeting: Name of Committee: Army National Cemeteries Advisory...: Lieutenant Colonel Renea Yates; renea-yates@us.army.mil or 571.256.4325. SUPPLEMENTARY INFORMATION:...

  4. Tolerância de rizóbios de diferentes procedências ao zinco, cobre e cádmio Tolerance of rhizobia genera from different origins to zinc, copper and cadmium

    Directory of Open Access Journals (Sweden)

    Alexandre Matsuda

    2002-03-01

    Full Text Available Sessenta estirpes/isolados dos gêneros Bradyrhizobium, Rhizobium, Sinorhizobium, Mesorhizobium e Azorhizobium, procedentes de diferentes locais (Mata Atlântica, Amazônia, culturas agrícolas e experimentos com metais pesados e de espécies hospedeiras pertencentes às subfamílias Papilionoideae, Mimosoideae e Caesalpinoideae, foram avaliadas quanto à tolerância a Zn, Cu e Cd em meio YMA modificado pela adição de tampões biológicos (HEPES e MES e suplementados com Cu (0 a 60 mg L-1, Cd (0 a 60 mg L-1 e Zn (0 a 1.000 mg L-1. Mediante padrões de crescimento atribuídos às culturas nas diferentes concentrações dos metais, avaliaram-se as concentrações máximas toleradas e as doses tóxicas destes metais para redução de crescimento em 25% (DT25 e 50% (DT50. Não houve influência da procedência na concentração máxima de metal tolerada. A ordem de sensibilidade aos metais, considerando-se as concentrações máximas toleradas, foi Azorhizobium > Rhizobium = Mesorhizobium = Sinorhizobium > Bradyrhizobium. A DT25 e a DT50 foram úteis para diferenciarem estirpes/isolados de um mesmo gênero, que atingiram a mesma concentração máxima tolerada a Zn, Cu e Cd. A ordem de toxicidade dos metais estudados foi Cu > Cd > Zn.Sixty strains/isolates of the genera Bradyrhizobium, Rhizobium, Sinorhizobium, Mesorhizobium and Azorhizobium, isolated from different hosts (legume subfamilies: Papilionoideae, Mimosoideae and Caesalpinoideae and location (Atlantic Forest, Amazon region, crop plantings and heavy metal experiments, were evaluated for Zn, Cu and Cd tolerance in YMA medium modified by the addition of biological buffers (HEPES and MES and supplemented with Cu (0 to 60 mg L-1, Cd (0 to 60 mg L-1, and Zn (0 to 1,000 mg L-1sulphates. Growth standards were applied to evaluate rhizobia cultures growth at different metal concentrations, allowing evaluation of highest tolerated concentrations of Zn, Cu, and Cd and the toxic doses

  5. Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wan, Chunli; Du, Maoan; Lee, Duu-Jong; Yang, Xue; Ma, Wencheng; Zheng, Lina

    2011-03-01

    Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m(-1) for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field.

  6. Dicty_cDB: Contig-U11279-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available :none) Streptomyces coelicolor A3(2) co... 35 6.0 CP000615_1733( CP000615 |pid:none) Burkholderia vietnam...P000616_372( CP000616 |pid:none) Burkholderia vietnamiensis G4 ch... 65 7e-09 AP009384_963( AP009384 |pid:none) Azorhizobium caulin...:none) Burkholderia vietnamiensis G4 c... 45 0.006 AD3255( AD3255 ) l-sorbose dehydrogenase (FAD) (EC ...:none) Streptomyces coelicolor A3(2) co... 40 0.19 CP000386_745( CP000386 |pid:none) Rubr... 3' end. 48 1.1 1 ( DU783019 ) ASXB731.g2 HF500_10-06-02 uncultured marine micro... 42 2.0 2 ( BJ391331 ) Dictyostelium discoid

  7. Electrokinetic remediation and microbial community shift of β-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil.

    Science.gov (United States)

    Wan, Chunli; Du, Maoan; Lee, Duu-Jong; Yang, Xue; Ma, Wencheng; Zheng, Lina

    2011-03-01

    Electrokinetic (EK) migration of β-cyclodextrin (β-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m(-1) for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field. PMID:21052991

  8. Electrokinetic remediation and microbial community shift of {beta}-cyclodextrin-dissolved petroleum hydrocarbon-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Wan, Chunli; Du, Maoan; Yang, Xue; Ma, Wencheng [Harbin Institute of Technology (China). School of Municipal and Environmental Engineering; Lee, Duu-Jong [National Taiwan Univ., Taipei (China). Dept. of Chemical Engineering; Zheng, Lina [Dalian Ocean Univ. (China). College of Marine Environmental Engineering

    2011-03-15

    Electrokinetic (EK) migration of {beta}-cyclodextrin ({beta}-CD), which is inclusive of total petroleum hydrocarbon (TPH), is an economically beneficial and environmentally friendly remediation process for oil-contaminated soils. Remediation studies of oil-contaminated soils generally prepared samples using particular TPHs. This study investigates the removal of TPHs from, and electromigration of microbial cells in field samples via EK remediation. Both TPH content and soil respiration declined after the EK remediation process. The strains in the original soil sample included Bacillus sp., Sporosarcina sp., Beta proteobacterium, Streptomyces sp., Pontibacter sp., Azorhizobium sp., Taxeobacter sp., and Williamsia sp. Electromigration of microbial cells reduced the biodiversity of the microbial community in soil following EK remediation. At 200 V m{sup -1} for 10 days, 36% TPH was removed, with a small population of microbial cells flushed out, demonstrating that EK remediation is effective for the present oil-contaminated soils collected in field. (orig.)

  9. Evaluation of nutrient limitation in aquatic ecosystems with nitrogen fixing bacteria

    Institute of Scientific and Technical Information of China (English)

    WU Gen-fu; WU Xue-chang; XUAN Xiao-dong; ZHOU Xue-ping

    2006-01-01

    There has always been a great need for simple and accurate bioassays for evaluating nutrient limitation in aquatic ecosystems. Whereas organic carbon is usually considered to be the limiting nutrient for microbial growth in many aquatic ecosystems,there are, however, many water sources that are limited by phosphorus or nitrogen. A method named "nitrogen fixing bacterial growth potential" (NFBGP) test, which is based on pre-culturing ofautochthonous (target) microorganisms was described. The method was applied to evaluate phosphorus or nitrogen nutrient limitation in lake and sewage water samples using an isolate of the nitrogen fixing bacterium, Azorhizobium sp. WS6. The results corresponded well to those from the traditional algal growth potential (AGP) test and the bacterial regrowth potential (BRP) test, suggesting that the NFBGP test is a useful supplementary method for evaluating the limiting nutrient, especially phosphorus, in an aquatic environment.

  10. Characterization and phylogenetic analysis of biosurfactant-producing bacteria isolated from palm oil contaminated soils

    Directory of Open Access Journals (Sweden)

    Kanokrat Saisa-ard

    2014-04-01

    Full Text Available Biosurfactant-producing bacteria were isolated from 89 different soil samples contaminated with palm oil in 35 palm oil industry sites in the south of Thailand. The phylogenetic diversity of the isolates was evaluated by 16S rRNA gene analysis. Among 1,324 colonies obtained, 134 isolates released extracellular biosurfactant when grown on low-cost substrates by a drop collapsing test. Among these, the 53 isolates that showed the highest biosurfactant production on different substrates were found to belong to 42 different bacterial genera. Among these sixteen (Caryophanon; Castellaniella; Filibacter; Geminicoccus; Georgenia; Luteimonas; Mesorhizobium; Mucilaginibacter; Nubsella; Paracoccus; Pedobacter; Psychrobacter; Rahnella; Sphingobium; Sphingopyxis and Sporosarcina were first reported as biosurfactant-producing strains. By using low-cost, agro-industrial by-products or wastes, Azorhizobium doebereinerae AS54 and Geminicoccus roseus AS73 produced extracellular biosurfactant, which exhibited the lowest surface tension reduction (25.5 mN/m and highest emulsification activity (69.0% when palm oil decanter cake and used palm oil was used as a carbon sources, respectively. Overall, this is the first study of a phylogenetic analysis of biosurfactant-producing bacteria from palm oil refinery industry site and their ability to produce biosurfactant on renewable substrates.

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

    OpenAIRE

    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...

  12. SITUACIÓN ACTUAL Y PERSPECTIVA DE LAS RELACIONES ENDÓFITAS PLANTA-BACTERIA. ESTUDIO DE CASO Gluconacetobacter diazotrophicus-CULTIVOS DE IMPORTANCIA ECONÓMICA

    Directory of Open Access Journals (Sweden)

    B. Dibut

    2009-01-01

    Full Text Available En los últimos años, ha ganado especial interés el estudio de las asociaciones endofíticas planta-microoganismos, con énfasis en la introducción en la práctica agrícola de los buenos resultados que se han obtenido en la agrobiología. En este trabajo se ofrece una panorámica de la situación actual y perspectiva de estas asociaciones ilustradas en gran medida por las interacciones Rhizobium-cereales, Azorhizobium-arroz, Azospirillum y Herbaspirillum, al igual que cereales y Gluconacetobacter diazotrophicus con diferentes cultivos. Se plantea un proceso de rotación microbiana que manifiesta la bacteria Rhizobium en las diferentes fases de asociación cíclica en el agroecosistema (leguminosa, nódulo-suelo-gramínea-suelo-leguminosa en función de la fisiología de la productividad y el rendimiento. En el estudio con G. diazotrophicus, en las determinaciones realizadas en viandas tropicales y frutales en las condiciones de Cuba, se encontró una concentración de células de 4.2x105 por gramo de tejido fresco en las plantas bacterizadas y 2.7x102 células por gramo de tejido fresco para las hojas de plantas controles (sin bacterizar; por eso, es necesario aumentar la concentración bacteriana, tanto en las condiciones experimentales como de extensión, para obtener una respuesta favorable del efecto agrobiológico sobre las especies antes relacionadas. La respuesta a la inoculación encontrada para yuca, malanga y papaya constituyen un primer informe mundial. El impacto económico como consecuencia de la inoculación es elevado, con una relación beneficio/ costo superior a 40:1, por lo que resulta una biotecnología sumamente atractiva para ser introducida en el mercado actual de agrobiológicos. Igualmente, el resultado presenta impacto científico, tecnológico, ambiental y social.