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azospirillum genomes reveal transition of bacteria from aquatic to terrestrial environments.fossil records indicate that life appeared in marine environments ∼3.5 billion years ago (gyr) and transitioned to terrestrial ecosystems nearly 2.5 gyr. sequence analysis suggests that "hydrobacteria" and "terrabacteria" might have diverged as early as 3 gyr. bacteria of the genus azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. we obtained genome sequences of two azospirillum species and analyzed their gene origins. while m ...201122216014
effect of genomic rearrangement on heavy metal tolerance in the plant-growth-promoting rhizobacterium azospirillum brasilense sp245.a derivative of azospirillum brasilense sp245, sp245.5, which spontaneously lost 85 and 120 mda replicons upon the formation of a new megaplasmid, has been shown to produce a novel lipopolysaccharide and to lose calcofluor-binding polysaccharides. as compared to sp245, the derivative displays notably increased heavy metal tolerance. the phenotypes of sp245 and sp245.5 are characterized by the following minimal inhibitory concentrations (mics) of heavy metals: 0.5 and 0.9 μmol l(-1) of ag(+), 0.4 ...201122130692
An improved rapid method for the preparation of d-rhamnose.A method is developed for the preparation of d-rhamnose from an O-polysaccharide (OPS) isolated by mild acid hydrolysis of Azospirillum brasilense SR75 cell mass. After the OPS hydrolysis, d-rhamnose was recovered by gel-permeation chromatography on Toyopearl TSK HW-40 and was crystallized. The sugar activity was demonstrated immunochemically. The advantages of the method are that it expedites and simplifies the extraction of d-rhamnose and increases its yield.201122099380
Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense.Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utili ...201222092983
the chemotaxis-like che1 pathway has an indirect role in adhesive cell properties of azospirillum brasilense.the azospirillum brasilense chemotaxis-like che1 signal transduction pathway was recently shown to modulate changes in adhesive cell surface properties that, in turn, affect cell-to-cell aggregation and flocculation behaviors rather than flagellar-mediated chemotaxis. attachment to surfaces and root colonization may be functions related to flocculation. here, the conditions under which a. brasilense wild-type sp7 and che1 mutant strains attach to abiotic and biotic surfaces were examined using i ...201122092709
dinitrogen fixation of microbe-plant associations as affected by nitrate and ammonium supply.abstract the dinitrogen fixation activity of azospirillum sp., and pantoea agglomerans strains was determined by (15)n(2) incorporation after incubation with (15)n(2) labeled air or/and by acetylene reduction. these bacterial strains were able to fix n(2) both in pure culture and in association with wheat plants in hydroponics. nitrogenase activity of azospirillum sp., in pure culture was more rapidly inhibited by the addition of nh(4) (+) than no(3) (-). the n(2) fixation of p. agglomerans de ...199722087483
crystal structure of the glnz-drag complex reveals a different form of pii-target interaction.nitrogen metabolism in bacteria and archaea is regulated by a ubiquitous class of proteins belonging to the p(ii)family. p(ii) proteins act as sensors of cellular nitrogen, carbon, and energy levels, and they control the activities of a wide range of target proteins by protein-protein interaction. the sensing mechanism relies on conformational changes induced by the binding of small molecules to p(ii) and also by p(ii) posttranslational modifications. in the diazotrophic bacterium azospirillum b ...201122074780
Diversity of 16S rRNA genes from bacteria of sugarcane rhizosphere soil.Sugarcane is an important agricultural product of Brazil, with a total production of more than 500 million tons. Knowledge of the bacterial community associated with agricultural crops and the soil status is a decisive step towards understanding how microorganisms influence crop productivity. However, most studies aim to isolate endophytic or rhizosphere bacteria associated with the plant by culture-dependent approaches. Culture-independent approaches allow a more comprehensive view of entire ba ...201122042267
Alginate beads provide a beneficial physical barrier against native microorganisms in wastewater treated with immobilized bacteria and microalgae.When the freshwater microalga Chlorella sorokiniana and the plant growth-promoting bacterium Azospirillum brasilense were deployed as free suspensions in unsterile, municipal wastewater for tertiary wastewater treatment, their population was significantly lower compared with their populations in sterile wastewater. At the same time, the numbers of natural microfauna and wastewater bacteria increased. Immobilization of C. sorokiniana and A. brasilense in small (2-4 mm in diameter), polymer Ca-alg ...201122038243
Field monitoring of plant-growth-promoting rhizobacteria by colony immunoblotting.Inoculant plant-growth-promoting bacteria are emerging as an important component of sustainable agriculture. There is a need to develop inexpensive methods for enumerating these organisms after their application in the field, to better understand their survival and impacts on yields. Immunoblotting is one potential method to measure viable cells, but the high cost of the conventionally used nylon membranes makes this method prohibitive. In this study, less expensive alternative materials such as ...201122017658
Structural peculiarities of the O-specific polysaccharides of Azospirillum bacteria of serogroup III.Lipopolysaccharides and O-specific polysaccharides were isolated from the outer membrane of bacterial cells of three strains belonging to two Azospirillum species, and their structures were established by monosaccharide analysis including determination of the absolute configurations, methylation analysis, and one- and two-dimensional NMR spectroscopy. It was shown that while having the identical composition, the O-polysaccharides have different branched tetrasaccharide repeating units. Two neutr ...201121999541
heat stability of proteobacterial pii protein facilitate purification using a single chromatography step.the p(ii) proteins comprise a family of widely distributed signal transduction proteins that integrate the signals of cellular nitrogen, carbon and energy status, and then regulate, by protein-protein interaction, the activity of a variety of target proteins including enzymes, transcriptional regulators and membrane transporters. we have previously shown that the p(ii) proteins from azospirillum brasilense, glnb and glnz, do not alter their migration behavior under native gel electrophoresis fol ...201121963770
elstera litoralis gen. nov., sp. nov. isolated from stone biofilms of lake constance after enrichment with diatom exudates.an alphaproteobacterium, strain dia-1t, was isolated from algae-dominated biofilms on stones from the littoral zone of lake constance, germany. this bacterium was isolated after initial enrichment in spent medium obtained after growth of a diatom culture. numerous sugars and few organic acids and alcohols serve as growth substrate. the bacterium grows slowly, is strictly aerobic but microaerophilic, and does not grow in cultures shaken under air. 16s rrna gene sequence analysis indicated that st ...201121948090
characterization of nitrogen-fixing bacteria isolated from field-grown barley, oat, and wheat.diazotrophic bacteria were isolated from the rhizosphere of field-grown triticum aestivum, hordeum vulgare, and avena sativa grown in various regions of greece. one isolate, with the highest nitrogen-fixation ability from each of the eleven rhizospheres, was selected for further characterisation. diazotrophic strains were assessed for plant-growth-promoting traits such as indoleacetic acid production and phosphate solubilisation. the phylogenies of 16s rrna gene of the selected isolates were com ...201121887633
volatile organic compounds from rhizobacteria increase biosynthesis of essential oils and growth parameters in peppermint (mentha piperita).volatile organic compounds (vocs), characterized by low molecular weight and high vapor pressure, are produced by all organisms as part of normal metabolism, and play important roles in communication within and between organisms. we examined the effects of vocs released by three species of plant growth-promoting rhizobacteria (pseudomonas fluorescens, bacillus subtilis, azospirillum brasilense) on growth parameters and composition of essential oils (eo) in the aromatic plant mentha piperita (pep ...201121843946
genomic insights into the versatility of the plant growth-promoting bacterium azospirillum amazonense.abstract:201121838888
a rapid and simple pcr method for identifying isolates of the genus azospirillum within populations of rhizosphere bacteria.aims: to develop a rapid and simple genus-specific polymerase chain reaction (pcr) method for detecting and identifying isolates of the genus azospirillum which is well-recognized as plant growth-promoting rhizobacterium. methods and results: nine pairs of pcr primers were designed based on the azospirillum 16s rrna, ipdc, nifa, and nifh genes to assess their genus specificity by testing against 12 azospirillum (from seven species) and 15 non-azospirillum reference strains, as compared with th ...201121790914
[ estimation of azospirillum lectins effect on camp level in plant cell ]. 201021774174
Azospirillum formosense sp. nov., a novel diazotrophic bacterium isolated from agricultural soil.A Gram-negative, spiral or rod-shaped, non-spore-forming diazotrophic bacterium (strain CC-Nfb-7T), was isolated from agricultural soil located in Yunlin County, Taiwan. The 16S rRNA gene sequence analysis of strain CC-Nfb-7T showed highest sequence similarity to Azospirillum brasilense DSM 1690T (97.4%), Azospirillum rugosum DSM 19657T (96.8%), and Azospirillum oryzae JCM 21588T (96.6%) and lower sequence similarity (< 96.5%) to all other Azospirillum species. DNA-DNA hybridizations of strain C ...201121742820
changes in the bacterial community structure and diversity during bamboo retting.microbial retting is a critical step in obtaining fiber bundles from bamboo culm using indigenous microorganisms. a cultivation-independent technique for monitoring the changes in bacteria community during bamboo retting was applied in this work. this technique involves genetic profiling of pcr-amplified small-subunit rrna and the single-strand conformation polymorphism (sscp) gel analysis of the pcr-amplified 16s rdna fragments. the study revealed that both the structure and the diversity of in ...201121695788
identification and isolation of active n(2)o reducers in rice paddy soil.dissolved n(2)o is occasionally detected in surface and ground water in rice paddy fields, whereas little or no n(2)o is emitted to the atmosphere above these fields. this indicates the occurrence of n(2)o reduction in rice paddy fields; however, identity of the n(2)o reducers is largely unknown. in this study, we employed both culture-dependent and culture-independent approaches to identify n(2)o reducers in rice paddy soil. in a soil microcosm, n(2)o and succinate were added as the electron ac ...201121677691
surface colonization by azospirillum brasilense sm in the indole-3-acetic acid dependent growth improvement of sorghum.the key to improving plant productivity is successful bacterial-plant interaction in the rhizosphere that can be maintained in the environment. the results presented here confirm azospirillum brasilense strain sm as a competent plant growth promoting bacterium over mid- and long-term associations with sorghum. this study establishes that plant growth can be directly correlated with the associated bacterium's indole-3-acetic acid (iaa) production capability as iaa over-expressing variants, smp30 ...201121656820
in vitro interaction between the ammonium transport protein amtb and partially uridylylated forms of the p(ii) protein glnz.the ammonium transport family amt/rh comprises ubiquitous integral membrane proteins that facilitate ammonium movement across biological membranes. besides their role in transport, amt proteins also play a role in sensing the levels of ammonium in the environment, a process that depends on complex formation with cytosolic proteins of the p(ii) family. trimeric p(ii) proteins from a variety of organisms undergo a cycle of reversible posttranslational modification according to the prevailing nitro ...201121645649
soil factors exhibit greater influence than bacterial inoculation on alfalfa growth and nitrogen fixation.in order to study effects of soil factors and bacterial inoculation on alfalfa (medicago sativa), plants were inoculated with ensifer meliloti l33 and azospirillum brasilense sp7 in pot experiments using two different soils separately as well as in a mixture. one soil was contaminated with chemical waste products; the other was an arable soil. soil factors, including availability of macro- and micronutrients as well as carbon and nitrogen contents were found to exhibit a much greater influence o ...201121627671
azospirillum sp. strain b510 enhances rice growth and yield.inoculation experiments with the endophytic bacterium azospirillum sp. strain b510, an isolate from surface-sterilized stems of field-grown rice, were conducted in pots in a greenhouse, and in paddy fields in hokkaido, japan. b510 significantly enhanced the growth of newly generated leaves and shoot biomass under greenhouse conditions. when rice seedlings were treated with 1×10(8) cfu ml(-1), then transplanted to paddy fields, tiller numbers and seed yield significantly increased. azospirillum s ...201021576855
tools for genetic manipulation of the plant growth-promoting bacterium azospirillum amazonense.abstract: background: azospirillum amazonense has potential to be used as agricultural inoculant since it promotes plant growth without causing pollution, unlike industrial fertilizers. owing to these facts, the study of this species has gained interest. however, a detailed understanding of its genetics and physiology is limited by the absence of appropriate genetic tools for the study of this species. results: conjugation and electrotransformation methods were established utilizing vectors with ...201121575234
endophytic bacteria in the rice plant.endophytic bacteria are defined as bacteria detected inside surface-sterilized plants or extracted from inside plants and having no visibly harmful effects on the plants. various kinds of endophytic bacteria, such as pantoea, methylobacterium, azospirillum, herbaspirillum, burkholderia and rhizobium etc., have been found inside rice plants. this minireview summarizes and discusses recent studies of endophytic bacteria residing in rice plants, focusing on flora, origin, movement, and interaction ...200821558696
characterization of a thiamin diphosphate-dependent phenylpyruvate decarboxylase from saccharomyces cerevisiae.the product of the aro10 gene from saccharomyces cerevisiae was initially identified as a thiamine diphosphate-dependent phenylpyruvate decarboxylase with a broad substrate specificity. it was suggested that the enzyme could be responsible for the catabolism of aromatic and branched-chain amino acids, as well as methionine. in the present study, we report the overexpression of the aro10 gene product in escherichia coli and the first detailed in vitro characterization of this enzyme. the enzyme i ...201121501384
improving casuarina growth and symbiosis with frankia under different soil and environmental conditions--review.casuarinas are very important plants for their various uses and survival in adverse sites or harsh environments. as nitrogen fixation, in symbiosis with frankia, is an important factor for the survival of these plants under various conditions, the basis for selecting both effective and tolerant frankia strains and casuarina spp., are provided. enhancement of the symbiotic relationship between frankia and casuarina, by mycorrhizal infection and other biofertilizing microorganisms such as bacillus ...201121448712
indole-3-acetic acid biosynthesis in the biocontrol strain pseudomonas fluorescens psd and plant growth regulation by hormone overexpression.pseudomonas fluorescens is an important biological component of agricultural soils that bestows a number of direct and indirect beneficial attributes to the plants. we analyzed the biocontrol strain p. fluorescens psd for indole-3-acetic acid (iaa) biosynthesis and studied the effect of its consequent manipulation on its plant-growth-promoting (pgp) potential. while the indole pyruvic acid (ipya) pathway commonly associated with pgp bacteria was lacking, the indole acetamide (iam) pathway genera ...201121397014
azospirillum and arbuscular mycorrhizal colonization enhance rice growth and physiological traits under well-watered and drought conditions.the response of rice plants to inoculation with an arbuscular mycorrhizal (am) fungus, azospirillum brasilense, or combination of both microorganisms, was assayed under well-watered or drought stress conditions. water deficit treatment was imposed by reducing the amount of water added, but am plants, with a significantly higher biomass, received the same amount of water as non-am plants, with a poor biomass. thus, the water stress treatment was more severe for am plants than for non-am plants. t ...201121377754
response to saline stress and aquaporin expression in azospirillum-inoculated barley seedlings.the ability of two strains of azospirillum brasilense to mitigate nacl stress in barley plants was evaluated. barley seedlings were inoculated and subjected to 200 mm nacl for 18 days. several days after nacl treatment, a significant decline in biomass as well as in height was observed in uninoculated plants. however, smaller reductions in biomass and height were detected in plants inoculated with strain az39. all the stressed plants showed significantly higher na(+) but lower k(+) contents in t ...201121365472
transcriptome analysis of the rhizosphere bacterium azospirillum brasilense reveals an extensive auxin response.the rhizosphere bacterium azospirillum brasilense produces the auxin indole-3-acetic acid (iaa) through the indole-3-pyruvate pathway. as we previously demonstrated that transcription of the indole-3-pyruvate decarboxylase (ipdc) gene is positively regulated by iaa, produced by a. brasilense itself or added exogenously, we performed a microarray analysis to study the overall effects of iaa on the transcriptome of a. brasilense. the transcriptomes of a. brasilense wild-type and the ipdc knockout ...201121340736
structural and functional peculiarities of the lipopolysaccharide of azospirillum brasilense sr55, isolated from the roots of triticum durum.azospirillum brasilense sr55, isolated from the rhizosphere of triticum durum, was classified as serogroup ii on the basis of serological tests. such serogroup affiliation is uncharacteristic of wheat-associated azospirillum species. the lipid a of a. brasilense sr55 lipopolysaccharide contained 3-hydroxytetradecanoic, 3-hydroxyhexadecanoic, hexadecanoic and octadecenoic fatty acids. the structure of the lipopolysaccharide's o polysaccharide was established, with the branched octasaccharide repe ...201121334868
rapid detection and identification of the free-living nitrogen fixing genus azospirillum by 16s rrna-gene-targeted genus-specific primers.the modern agricultural practice utilizing plant growth promoting rhizobacteria (pgpr) has brought great benefits in the promotion of crop growth. among pgpr, azospirillum is considered as an important genus which is not only closely-associated with plants but also shows potential in the degradation of organic contaminants. however, lack of media for selective isolation or techniques for specific detection or identification limit the exploration of these rhizobacteria. this motivated us to desig ...201121327476
the role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol pseudomonas fluorescens f113 on azospirillum brasilense phytostimulators.pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. here, the effects of synthetic phl and phl(+) pseudomonas fluorescens f113 on azospirillum brasilense phytostimulators were investigated. most a. brasilense strains were moderately sensitive to phl. in vitro, phl induced accumulation of carotenoids and poly-ß-hydroxybutyrate-like granules, cytopl ...201121273247
cdna-aflp analysis of differential gene expression related to cell chemotactic and encystment of azospirillum brasilense.our previous study indicated org35 was involved in chemotaxis and interacted with nitrogen fixation transcriptional activator nifa via pas domain. in order to reveal the role of org35 in nitrogen regulation, the downstream target genes of org35 were identified. we here report differentially expressed genes in org35 mutants comparing with wild type sp7 by means of cdna-aflp. four up-regulated transcript-derived fragments (tdfs) homologues of chemotaxis transduction proteins were found, including ...201121242066
azospirillum brasilense siderophores with antifungal activity against colletotrichum acutatum.anthracnose, caused by the fungus colletotrichum acutatum is one of the most important diseases in strawberry crop. due to environmental pollution and resistance produced by chemical fungicides, nowadays biological control is considered a good alternative for crop protection. among biocontrol agents, there are plant growth-promoting bacteria, such as members of the genus azospirillum. in this work, we demonstrate that under iron limiting conditions different strains of a. brasilense produce side ...201121234749
an extracytoplasmic function sigma factor cotranscribed with its cognate anti-sigma factor confers tolerance to nacl, ethanol and methylene blue in azospirillum brasilense sp7.azospirillum brasilense, a plant-growth-promoting rhizobacterium, is exposed to changes in its abiotic environment, including fluctuations in temperature, salinity, osmolarity, oxygen concentration and nutrient concentration, in the rhizosphere and in the soil. since extra-cytoplasmic function (ecf) sigma factors play an important role in stress adaptation, we analysed the role of ecf sigma factor (also known as rpoe or s(e)) in abiotic stress tolerance in a. brasilense. an in-frame rpoe deletio ...201121233159
a cher/cheb fusion protein is involved in cyst cell development and chemotaxis in azospirillum brasilense sp7.we here report the sequence and functional analysis of cstb of azospirillum brasilense sp7. the predicted cstb contains c-terminal two pas domains and n-terminal part which has similarity with cheb-cher fusion protein. cstb mutants had reduced swarming ability compared to that of a. brasilense wild-type strain, implying that cstb was involved in chemotaxis in a. brasilense. a microscopic analysis revealed that cstb mutants developed mature cyst cells more quickly than wild type, indicating that ...201121232929
cyclic gmp controls rhodospirillum centenum cyst development.adenylyl cyclases are widely distributed across all kingdoms whereas guanylyl cyclases are generally thought to be restricted to eukaryotes. here we report that the α-proteobacterium rhodospirillum centenum secretes cgmp when developing cysts and that a guanylyl cyclase deletion strain fails to synthesize cgmp and is defective in cyst formation. the r. centenum cyclase was purified and shown to effectively synthesize cgmp from gtp in vitro, demonstrating that it is a functional guanylyl cyclase. ...201121214648
genetic and phenotypic diversity of plant growth promoting rhizobacteria isolated from sugarcane plants growing in pakistan.bacteria were isolated from roots of sugarcane varieties grown in the fields of punjab. they were identified by using api20e/ne bacterial identification kits and from sequences of 16s rrna and amplicons of the cpn60 gene. the majority of bacteria were found to belong to the genera of enterobacter, pseudomonas, and klebsiella, but members of genera azospirillum, rhizobium, rahnella, delftia, caulobacter, pannonibacter, xanthomonas, and stenotrophomonas were also found. the community, however, was ...201021193815
bacterial communities associated with the lichen symbiosis.lichens are commonly described as a mutualistic symbiosis between fungi and "algae" (chlorophyta or cyanobacteria); however, they also have internal bacterial communities. recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. however, we still have a limited understanding of the phylogenetic structure of these communities and their variability across li ...201021169444
dynamics, diversity and function of endophytic siderophore-producing bacteria in rice.siderophore production confers to bacteria competitive advantages to colonize plant tissues and to exclude other microorganisms from the same ecological niche. this work shows that the community of endophytic siderophore-producing bacteria (spb) associated to oryza sativa cultivated in uruguayan soils is dynamic and diverse. these bacteria were present in grains, roots, and leaves, and their density fluctuated between log(10) 3.44 and log(10) 5.52 cfu g(-1) fresh weight (fw) during the plant gro ...201021128071
characterization of cell surface and extracellular matrix remodeling of azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy.to compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. in azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in ...201021105907
low endotoxic activity of lipopolysaccharides isolated from bradyrhizobium, mesorhizobium, and azospirillum strains.the endotoxic activities of lipopolysaccharides (lps) isolated from different strains of rhizobia and rhizobacteria (bradyrhizobium, mesorhizobium, and azospirillum) were compared to those of salmonella enterica sv. typhimurium lps. the biological activity of all the examined preparations, measured as limulus lysate gelation, production of tumor necrosis factor (tnf), interleukin-1β (il-1β), and interleukin-6 (il-6), and nitrogen oxide (no) induction in human myelomonocytic cells (line thp-1), w ...201021091983
isolation of oligotrophic denitrifiers carrying previously uncharacterized functional gene sequences.oligotrophic denitrifying bacteria, including those belonging to the genera herbaspirillum, azospirillum, and bradyrhizobium, were obtained using a single-cell isolation technique. the taxonomic composition of the denitrifier population was similar to those assessed by previous culture-independent studies. the sequencing of nitrite reductase and n(2)o reductase genes of these strains revealed previously unknown links between 16s rrna and the denitrification-functional gene phylogenies. in partic ...201021075882
the pseudomonas secondary metabolite 2,4-diacetylphloroglucinol is a signal inducing rhizoplane expression of azospirillum genes involved in plant-growth promotion.during evolution, plants have become associated with guilds of plant-growth-promoting rhizobacteria (pgpr), which raises the possibility that individual pgpr populations may have developed mechanisms to cointeract with one another on plant roots. we hypothesize that this has resulted in signaling phenomena between different types of pgpr colonizing the same roots. here, the objective was to determine whether the pseudomonas secondary metabolite 2,4-diacetylphloroglucinol (dapg) can act as a sign ...201121043573
host plant secondary metabolite profiling shows a complex, strain-dependent response of maize to plant growth-promoting rhizobacteria of the genus azospirillum.most azospirillum plant growth-promoting rhizobacteria (pgpr) benefit plant growth through source effects related to free nitrogen fixation and/or phytohormone production, but little is known about their potential effects on plant physiology. these effects were assessed by comparing the early impacts of three azospirillum inoculant strains on secondary metabolite profiles of two different maize (zea mays) cultivars. after 10d of growth in nonsterile soil, maize methanolic extracts were analyzed ...201020946131
a hybrid two-component system protein from azospirillum brasilense sp7 was involved in chemotaxis.we here report the sequence and functional analysis of org35 of azospirillum brasilense sp7, which was originally identified to be able to interact with nifa in yeast-two-hybrid system. the org35 encodes a hybrid two-component system protein, including n-terminal pas domains, a histidine kinase (hpk) domain and a response regulator (rr) domain in c-terminal. to determine the function of the org35, a deletion-insertion mutant in pas domain [named sp7353] and a complemental strain sp7353c were con ...201020869221
the genetic diversity of culturable nitrogen-fixing bacteria in the rhizosphere of wheat.a total of 17 culturable nitrogen-fixing bacterial strains associated with the roots of wheat growing in different regions of greece were isolated and characterized for plant-growth-promoting traits such as auxin production and phosphate solubilization. the phylogenetic position of the isolates was first assessed by the analysis of the pcr-amplified 16s rrna gene. the comparative sequence analysis and phylogenetic analysis based on 16s rrna gene sequences show that the isolates recovered in this ...201120857096
the auxin-signaling pathway is required for the lateral root response of arabidopsis to the rhizobacterium phyllobacterium brassicacearum.plant root development is highly responsive both to changes in nitrate availability and beneficial microorganisms in the rhizosphere. we previously showed that phyllobacterium brassicacearum stm196, a plant growth-promoting rhizobacteria strain isolated from rapeseed roots, alleviates the inhibition exerted by high nitrate supply on lateral root growth. since soil-borne bacteria can produce iaa and since this plant hormone may be implicated in the high nitrate-dependent control of lateral root d ...201020844890
[localization of denitrification genes in plasmid dna of bacteria azospirillum brasilense].in 85-mda plasmid (p85) of plant-associated bacteria azospirillum brasilense sp245 model strain, the genes encoding copper-containing nitrite reductase (nirk); heterodimeric no-reductase (norcb); norq and nord proteins affecting synthesis and (or) activation of nirk and (or) no-reductase (norqd); catalytic subunit i ofcytochrom c oxidase (cccon); presumable no sensor carrying two hemeerythrine domains (orf181); and an enzyme required for synthesis of presumable no antagonist, homocystein (metc) ...201020795494
capsular polysaccharide of the bacterium azospirillum lipoferum sp59b: structure and antigenic specificity.antigenic differences were revealed between the cell wall outer membrane lipopolysaccharides and the capsular high molecular weight bioglycans for a typical strain of the nitrogen-fixing rhizobacterium azospirillum lipoferum sp59b using antibodies prepared against the homologous lipopolysaccharide and lipopolysaccharide-protein complex. from the capsular lipopolysaccharide-protein and polysaccharide-lipid complexes of a. lipoferum sp59b, polysaccharides were isolated and their structure was for ...201020632940
growth of quailbush in acidic, metalliferous desert mine tailings: effect of azospirillum brasilense sp6 on biomass production and rhizosphere community structure.mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. the contribution of the plant growth promoting bacterium (pgpb) azospirillum brasilense sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along ...201020632001
gene encoding gamma-carbonic anhydrase is cotranscribed with argc and induced in response to stationary phase and high co2 in azospirillum brasilense sp7.carbonic anhydrase (ca) is a ubiquitous enzyme catalyzing the reversible hydration of co2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. gamma class carbonic anhydrases (gamma-cas) are widespread in prokaryotes but their physiological roles remain elusive. at present, only gamma-ca of methanosarcina thermophila (cam) has been shown to have ca activity. genome analysis of a rhizobacterium azospirillum brasilense, revealed occurrence of orfs encoding one bet ...201020598158
[the structure of the o-specific polysaccharide from a mutant of nitrogen-fixing rhizobacterium azospirillum brasilense sp245 with an altered plasmid content].the rhizobacteria azospirillum brasilense sp245 produce antigenically different lipopolysaccharides lpsi and lpsii, both containing identical pentasaccharides built from d-rhamnose residues as the repeated chains of o-specific oligosaccharides (ops). in this study, we report the structure of the ops from a. brasilense lpsi(-)lpsii(-)-mutant sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-mda megaplasmid after the long-term storage of the bacteria in a ...201020531482
endophytic bacterial diversity in roots of phragmites australis in constructed beijing cuihu wetland (china).the community structure and diversity of endophytic bacteria in reed (phragmites australis) roots growing in the beijing cuihu wetland, china was investigated using the 16s rrna library technique. primers 799f and 1492r were used to amplify the specific bacterial 16s rrna fragments successfully and construct the clone library. in total, 166 individual sequences were verified by colony pcr and used to assess the diversity of endophytic bacteria in reed roots. phylogenetic analysis revealed that 7 ...201020528944
effect of pesticides on soil microbial community.according to guidelines for the approval of pesticides, information about effects of pesticides on soil microorganisms and soil fertility are required, but the relationships of different structures of pesticides on the growth of various groups of soil microorganisms are not easily predicted. some pesticides stimulate the growth of microorganisms, but other pesticides have depressive effects or no effects on microorganisms. for examples, carbofuran stimulated the population of azospirillum and ot ...201020512724
a new p(ii) protein structure identifies the 2-oxoglutarate binding site.p(ii) proteins of bacteria, archaea, and plants regulate many facets of nitrogen metabolism. they do so by interacting with their target proteins, which can be enzymes, transcription factors, or membrane proteins. a key feature of the ability of p(ii) proteins to sense cellular nitrogen status and to interact accordingly with their targets is their binding of the key metabolic intermediate 2-oxoglutarate (2-og). however, the binding site of this ligand within p(ii) proteins has been controversia ...201020493877
diversity of nitrogenase (nifh) genes pool in soybean field soil after continuous and rotational cropping.diazotrophs diversity in soybean is a topic requiring thorough investigation since the previous researches have focused on only rice, forest, grass, water, etc. in this research, iron-only nitrogenase nifh gene was as genetic marker. pcr-rflp was used to investigate the difference of diazotrophs community diversity in the soil from the continuous cropping (cc) (the 5-yr tilling of soybean) and the rotational cropping (rc) (soybean-corn) soils in the northeast of china. a total of 36 isolates wer ...201020473958
[toxicological evaluation of biopreparations on the basis of nitrogen-fixing bacteria].a comparative analysis of results of toxicological research of microbiological preparations on the basis of different species of nitrogen-fixing microorganisms of azotobacter, agrobacterium, azospirillum general and pathogenic properties of strains-producers has been carried out. a possibility to improve methodical principles of toxicological estimation and hygienic regulation of associative nitrogen-fixing microorganisms-producers and preparations on their basis in the industrial objects and en ...200920455429
[plasmid rearrangements and azospirillum brasilense biofilm formation]. 201020411670
bacterial community associated with healthy and diseased reef coral mussismilia hispida from eastern brazil.in order to characterize the bacterial community diversity associated to mucus of the coral mussismilia hispida, four 16s rdna libraries were constructed and 400 clones from each library were analyzed from two healthy colonies, one diseased colony and the surrounding water. nine bacterial phyla were identified in healthy m. hispida, with a dominance of proteobacteria, actinobacteria, acidobacteria, lentisphaerae, and nitrospira. the most commonly found species were related to the genera azospiri ...201020352207
[effect of lectins from azospirillum brasilense to peroxidase and oxalate oxidase activity regulation in wheat roots].lectins were extracted from the surface of nitrogen-fixing soil bacteria azospirillum brasilense sp7 and from its mutant a. brasilense sp7.2.3 defective in lectin activity. the ability oflectins to stimulate the rapid formation of hydrogen peroxide related to increase of oxalate oxidase and peroxidase activity in the roots of wheat seedlings has been demonstrated. the most rapid induced pathway of hydrogen peroxide formation in the roots of wheat seedlings was the oxalic acid oxidation by oxalat ...201020235434
[electrooptical properties of the microbial suspensions during a cell's interaction with the antibodies of a different specificity].the electrooptical abilities of the microbial suspensions during a cells interaction with antibodies (abs) of a different specificity have been studied on the example of the azospirillum brasilense sp245 cells and their interaction with the polyclonal monospecific and polyspecific antibodies. measuring of the orientational spectra of the cells has been performed using the elus electrooptical analyzer. a discrete frequency set of an orienting electric field (740, 1000, 1450, 2000, and 2800 khz) w ...201020198920
changes in pelagic bacteria communities due to leaf litter addition.in many limnetic systems, the input of allochthonous organic matter, e.g., leaf litter, is a substantial source of dissolved organic carbon (doc) for pelagic bacteria, especially in fall and winter when autochthonous doc production is low. however, relatively little is known about community changes of pelagic lake bacteria due to leaf litter input which includes both the release of leaf leachates and microorganisms from the leaf litter into the surrounding water. therefore, we have experimentall ...201020198369
assessment of scar markers to design real-time pcr primers for rhizosphere quantification of azospirillum brasilense phytostimulatory inoculants of maize.to assess the applicability of sequence characterized amplified region (scar) markers obtained from box, eric and rapd fragments to design primers for real-time pcr quantification of the phytostimulatory maize inoculants azospirillum brasilense uap-154 and cfn-535 in the rhizosphere.201020141548
effects of azospirillum brasilense with genetically modified auxin biosynthesis gene ipdc upon the diversity of the indigenous microbiota of the wheat rhizosphere.the phytostimulatory properties of azospirillum inoculants, which entail production of the phytohormone indole-3-acetic acid (iaa), can be enhanced by genetic means. however, it is not known whether this could affect their interactions with indigenous soil microbes. here, wheat seeds were inoculated with the wild-type strain azospirillum brasilense sp245 or one of three genetically modified (gm) derivatives and grown for one month. the gm derivatives contained a plasmid vector harboring the indo ...201020138146
pas domain containing chemoreceptor couples dynamic changes in metabolism with chemotaxis.chemoreceptors provide sensory specificity and sensitivity that enable motile bacteria to seek optimal positions for growth and metabolism in gradients of various physicochemical cues. despite the abundance of chemoreceptors, little is known regarding the sensory specificity and the exact contribution of individual chemoreceptors to the lifestyle of bacteria. azospirillum brasilense are motile bacteria that can fix atmospheric nitrogen under microaerophilic conditions. here, we characterized a c ...201020133866
azospirillum thiophilum sp. nov., a diazotrophic bacterium isolated from a sulfide spring.a novel nitrogen-fixing strain, designated bv-s(t), was isolated from a sulfur bacterial mat collected from a sulfide spring of the stavropol krai, north caucasus, russia. strain bv-s(t) grew optimally at ph 7.5 and 37°c. according to the results of phylogenetic analysis, strain bv-s(t) belonged to the genus azospirillum within the family rhodospirillaceae of the class alphaproteobacteria. within the genus azospirillum, strain bv-s(t) was most closely related to azospirillum doebereinerae gsf71( ...201020081019
complete genomic structure of the cultivated rice endophyte azospirillum sp. b510.we determined the nucleotide sequence of the entire genome of a diazotrophic endophyte, azospirillum sp. b510. strain b510 is an endophytic bacterium isolated from stems of rice plants (oryza sativa cv. nipponbare). the genome of b510 consisted of a single chromosome (3,311,395 bp) and six plasmids, designated as pab510a (1,455,109 bp), pab510b (723,779 bp), pab510c (681,723 bp), pab510d (628,837 bp), pab510e (537,299 bp), and pab510f (261,596 bp). the chromosome bears 2893 potential protein-enc ...201020047946
synthesis of a tetrasaccharide related to the o-antigen from azospirillum lipoferum sr65.concise synthesis of a tetrasaccharide repeating unit of the lps isolated from azospirillum lipoferum sr65 has been accomplished through suitable protecting group manipulations and stereoselective glycosylation starting from commercially available l-rhamnose and d-glucose. the target oligosaccharide in the form of its p-methoxyphenyl glycoside is suitable for further glycoconjugate formation via selective cleavage of the omp glycoside. plant growth-promoting bacteria (pgpb) of genus azospirillum ...201020035930
systemic induction of monoterpene biosynthesis in origanumxmajoricum by soil bacteria.italian oregano (origanumxmajoricum) was subjected to root system inoculation with three species of plant growth-promoting rhizobacteria (pgprs) (pseudomonas fluorescens, bacillus subtilis, azospirillum brasilense), and essential oil (eo) content and plant growth were measured. composition of monoterpenes, a major eo component, was analyzed qualitative and quantitatively by gas chromatography. total eo yield for plants inoculated with p. fluorescens or a. brasilense was 3.57 and 3.41 microg/mg f ...201020000572
effects of colonization of a bacterial endophyte, azospirillum sp. b510, on disease resistance in rice.agriculturally important grasses contain numerous diazotrophic bacteria, the interactions of which are speculated to have some other benefits to the host plants. in this study, we analyzed the effects of a bacterial endophyte, azospirillum sp. b510, on disease resistance in host rice plants. rice plants (oryza sativa cv. nipponbare) were inoculated with b510 exhibited enhanced resistance against diseases caused by the virulent rice blast fungus magnaporthe oryzae and by the virulent bacterial pa ...200919966496
bio-filtration of trichloroethylene using diazotrophic bacterial community.biodegradation of tce was studied in a biofilter packed with wood charcoal and inoculated with diazotrophic bacterial community isolated from local soil. steady state tce removal efficiencies higher than 85% were observed up to inlet load of 2.866 g m(-3) h(-1). the maximum elimination capacity of 5.31 g m(-3) h(-1) was observed at an inlet load of more than 7.90 g m(-3) h(-1). the biofilter was sensitive to fluctuations in the process conditions but could easily recover its performance after 10 ...201019962302
[identification of azospirillum genus bacteria isolated from the spring wheat root zone].bacteria with high n2-fixing activity were isolated from the root zone of spring wheat grown on leach chernozem and soddy podzolic soil in ukrainian marshy woodlands. they were characterized by phenotypic signs and investigated with the help of molecular-genetic methods. on the basis of diagnostic signs the investigated strains were referred to azospirillum brasilense from azospirillum genus. their 3'- and 5'-thermal 16s rna hypervariable sites with length from 373 to 395 nucleotides were amplif ...200919938589
isolation of functional single cells from environments using a micromanipulator: application to study denitrifying bacteria.we developed a novel method to isolate functionally active single cells from environmental samples and named it the functional single-cell (fsc) isolation method. this method is based on a combination of substrate-responsive direct viable counts, live-cell staining with 5-carboxyfluorescein diacetate acetoxymethyl ester, and micromanipulation followed by cultivation in a medium. to evaluate this method, we applied it to study a denitrifying community in rice paddy soil. similar denitrifier count ...201019936739
changes in cucumber hypocotyl cell wall dynamics caused by azospirillum brasilense inoculation.we previously reported that azospirillum brasilense induced a more elastic cell wall and a higher apoplastic water fraction in both wheat coleoptile and flag leaf. these biophysical characteristics could permit increased growth. knowledge of the biochemical effects the bacteria could elicit in plant cell walls and how these responses change plant physiology is still scarce. the objective of this work was to analyze whether a. brasilense sp245 inoculation affected elongation and extensibility of ...201019875302
transformation of the water soluble fraction from "alpeorujo" by coriolopsis rigida: the role of laccase in the process and its impact on azospirillum brasiliense survival.the objective of this work was to evaluate the ability of the white rot basidiomycete coriolopsis rigida to detoxify the water soluble fraction from "alpeorujo" (wsfa), a solid by-product produced by the olive oil extraction industry and characterized by a high concentration of phenols which limits its use as fertilizer and/or amendment. c. rigida reduced the phenol content in the liquid media supplemented with wsfa at 10 and 20% (v/v) after 15d of incubation. the analysis of wsfa toxicity after ...201019875147
glycogen phosphorylase is involved in stress endurance and biofilm formation in azospirillum brasilense sp7.here we report the identification of a glycogen phosphorylase (glgp) gene in the plant growth-promoting rhizobacterium azospirillum brasilense, sp7, and the characterization of a glgp marker exchange mutant of this strain. the glgp mutant showed a twofold reduction of glycogen phosphorylase activity and an increased glycogen accumulation as compared with wild-type sp7, indicating that the identified gene indeed encodes a protein with glycogen phosphorylase activity. interestingly, the glgp mutan ...200919765087
the azospirillum brasilense sp7 noej and noel genes are involved in extracellular polysaccharide biosynthesis.azospirillum brasilense is a plant root-colonizing bacterium that exerts beneficial effects on the growth of many agricultural crops. extracellular polysaccharides of the bacterium play an important role in its interactions with plant roots. the prhico plasmid of a. brasilense sp7, also named p90, carries several genes involved in synthesis and export of cell surface polysaccharides. we generated two sp7 mutants impaired in two prhico-located genes, noej and noel, encoding mannose-6-phosphate is ...200919762447
rhizosphere bacterial communities associated with disease suppressiveness stages of take-all decline in wheat monoculture.the decline of take-all disease (gaeumannomyces graminis var. tritici), which may take place during wheat monocropping, involves plant-protecting, root-colonizing microorganisms. so far, however, most work has focused on antagonistic fluorescent pseudomonads. our objective was to assess the changes in rhizobacterial community composition during take-all decline of field-grown wheat. the study was based on the development and utilization of a taxonomic 16s rrna-based microarray of 575 probes, cou ...200919732350
molecular diversity of diazotrophs in oligotrophic tropical seagrass bed communities.denaturing gradient gel electrophoresis (dgge) was employed to resolve pcr-amplified nifh sequences from vegetated and unvegetated sediments from two oligotrophic seagrass bed sites on san salvador island, bahamas, in order to assess diazotroph species composition. all dgge profiles from these sites showed the same prominent bands. these bands were sequenced, yielding 67 different nifh sequences, which were used in phylogenetic reconstructions. most sequences were from anaerobes, but some were a ...200219709190
regulation of expression and biochemical characterization of a beta-class carbonic anhydrase from the plant growth-promoting rhizobacterium, azospirillum brasilense sp7.carbonic anhydrase (ca; [ec 4.2.1.1]) is a ubiquitous enzyme catalysing the reversible hydration of co(2) to bicarbonate, a reaction that supports various biochemical and physiological functions. genome analysis of azospirillum brasilense, a nonphotosynthetic, nitrogen-fixing, rhizobacterium, revealed an orf with homology to beta-class carbonic anhydrases (cas). biochemical characteristics of the beta-class ca of a. brasilense, analysed after cloning the gene (designated as bca), overexpressing ...200919694814
fluctuation of microbial activities after influent load variations in a full-scale sbr: recovery of the biomass after starvation.due to variations in the production levels, a full-scale sequencing batch reactor (sbr) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. in order to study how these changes affected the n-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. the recover capacity of the biomass was also studied in a lab-scale reactor opera ...200919629470
d-xylose degradation pathway in the halophilic archaeon haloferax volcanii.the pathway of d-xylose degradation in archaea is unknown. in a previous study we identified in haloarcula marismortui the first enzyme of xylose degradation, an inducible xylose dehydrogenase (johnsen, u., and schönheit, p. (2004) j. bacteriol. 186, 6198-6207). here we report a comprehensive study of the complete d-xylose degradation pathway in the halophilic archaeon haloferax volcanii. the analyses include the following: (i) identification of the degradation pathway in vivo following (13)c-la ...200919584053
applicability of the 16s-23s rdna internal spacer for pcr detection of the phytostimulatory pgpr inoculant azospirillum lipoferum crt1 in field soil.to assess the applicability of the 16s-23s rdna internal spacer regions (isr) as targets for pcr detection of azospirillum ssp. and the phytostimulatory plant growth-promoting rhizobacteria seed inoculant azospirillum lipoferum crt1 in soil.201019583800
enhancement of growth and nutrient uptake of rapeseed (brassica napus l.) by applying mineral nutrients and biofertilizers.for investigating the effect of chemical fertilizer as well as biofertilizers on seed yield and quality i.e. oil, protein and nutrients concentration of rapeseed (brassica napus l.), a split-plot fertilizers application experimental design in 4 replications was carried out during the 2005-2006 growing season, at the gharakheil agricultural research station in the mazandaran province of iran. rapeseed was grown as a second crop in rotation after rice. biofertilizers treatments were two different ...200919579932
screening plant growth promoting rhizobacteria for improving seed germination, seedling growth and yield of maize.the effect of plant growth-promoting rhizobacteria (pgpr) on seed germination, seedling growth and yield of field grown maize were evaluated in three experiments. in these experiments six bacterial strains include p. putida strain r-168, p. fluorescens strain r-93, p. fluorescens dsm 50090, p. putida dsm291, a. lipoferum dsm 1691 and a. brasilense dsm 1690 were used. results of first study showed seed inoculation significantly enhanced seed germination and seedling vigour of maize. in second exp ...200919579914
plant-microbe interactions promoting plant growth and health: perspectives for controlled use of microorganisms in agriculture.plant-associated microorganisms fulfill important functions for plant growth and health. direct plant growth promotion by microbes is based on improved nutrient acquisition and hormonal stimulation. diverse mechanisms are involved in the suppression of plant pathogens, which is often indirectly connected with plant growth. whereas members of the bacterial genera azospirillum and rhizobium are well-studied examples for plant growth promotion, bacillus, pseudomonas, serratia, stenotrophomonas, and ...200919568745
comparison of rhizobacterial community composition in soil suppressive or conducive to tobacco black root rot disease.work on soils suppressive to thielaviopsis basicola-mediated tobacco black root rot has focused on antagonistic pseudomonads to date. the role of non-pseudomonas rhizosphere populations has been neglected, and whether they differ in black root rot-suppressive versus -conducive soils is unknown. to assess this possibility, tobacco was grown in a suppressive and a conducive soil of similar physicochemical properties, and rhizobacterial community composition was compared using a 16s rrna taxonomic ...200919554036
crystal structure of dinitrogenase reductase-activating glycohydrolase (drag) reveals conservation in the adp-ribosylhydrolase fold and specific features in the adp-ribose-binding pocket.protein-reversible adp-ribosylation is emerging as an important post-translational modification used to control enzymatic and protein activity in different biological systems. this modification regulates nitrogenase activity in several nitrogen-fixing bacterial species. adp-ribosylation is catalyzed by adp-ribosyltransferases and is reversed by adp-ribosylhydrolases. the structure of the adp-ribosylhydrolase that acts on azospirillum brasilense nitrogenase (dinitrogenase reductase-activating gly ...200919477184
trehalose accumulation in azospirillum brasilense improves drought tolerance and biomass in maize plants.bacteria of the genus azospirillum increase the grain yield of several grass crops. in this work the effect of inoculating maize plants with genetically engineered azospirillum brasilense for trehalose biosynthesis was determined. transformed bacteria with a plasmid harboring a trehalose biosynthesis gene-fusion from saccharomyces cerevisiae were able to grow up to 0.5 m nacl and to accumulate trehalose, whereas wild-type a. brasilense did not tolerate osmotic stress or accumulate significant le ...200919459961
isolation of bacterial strains from bovine fecal microflora capable of degradation of ceftiofur.ceftiofur, a third-generation cephalosporin used to treat bacterial infections in animals, is degraded in bovine feces but the specific bacteria involved are unknown. to find the bacteria involved in ceftiofur metabolism, the bovine fecal microflora was screened. twenty-one nonidentical strains of bovine fecal bacteria were isolated on media containing 1-32 microg ml(-1) of ceftiofur. the cultures were incubated with 5 microg ml(-1) ceftiofur for different times, then centrifuged and analyzed by ...200919428193
characterization of chsa, a new gene controlling the chemotactic response in azospirillum brasilense sp7.we report, here, the characterization of a mutant strain of azospirillum brasilense sp7 impaired in surface motility and chemotactic response. presence of flagella in the mutant strain was confirmed by western blot analysis, using antisera raised against the polar and lateral flagellins, and by electron microscopy. genetic complementation and nucleotide sequencing led to the identification of a new gene, named chsa. the deduced translation product, chsa protein, contained a pas sensory domain an ...200919390839
identification of the glutamine synthetase adenylyltransferase of azospirillum brasilense.glutamine synthetase, a key enzyme in nitrogen metabolism of both prokaryotes and eukaryotes, is strictly regulated. one means of regulation is the modulation of activity through adenylylation catalyzed by adenylyltransferases. using pcr primers based on conserved sequences in glutamine synthetase adenylyltransferases, we amplified part of the glne gene of azospirillum brasilense sp7. the complete glne sequence of a. brasilense sp245 was retrieved from the draft genome sequence of this organism ...200919366628
gut-associated denitrification and in vivo emission of nitrous oxide by the earthworm families megascolecidae and lumbricidae in new zealand.previous studies have documented the capacity of european earthworms belonging to the family lumbricidae to emit the greenhouse gas nitrous oxide (n(2)o), an activity attributed primarily to the activation of ingested soil denitrifiers. to extend the information base to earthworms in the southern hemisphere, four species of earthworms in new zealand were examined for gut-associated denitrification. lumbricus rubellus and aporrectodea rosea (introduced species of lumbricidae) emitted n(2)o, where ...200919346358
[diverse morphological types of dormant cells and conditions for their formation in azospirillum brasilense].differences in generation of dormant forms (df) were revealed between two strains of non-sporeforming gram-negative bacteria azospirillum brasilense, sp7 (non-endophytic) and sp245 (endophytic strain). in post-stationary ageing bacterial cultures grown in a synthetic medium with a fivefold decreased initial nitrogen content, strain sp7 formed two types of cyst-like resting cells (crc). strain sp245 did not form such types of df under the same conditions. crc of the first type were formed in stra ...200919334596
alkyl hydroperoxide reductase has a role in oxidative stress resistance and in modulating changes in cell-surface properties in azospirillum brasilense sp245.an ahpc mutant derivative of azospirillum brasilense sp245 (strain sk586) that encodes an alkyl hydroperoxide reductase was found to be more sensitive to oxidative stress caused by organic hydroperoxides compared with the wild-type. in addition, the ahpc mutant strain had multiple defects in a large array of cellular functions that were consistent with alteration of cell-surface properties, such as cell morphology in stationary phase, calcofluor white-, congo red- and lectin-binding abilities, a ...200919332821
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