| [determination of the structure of the repeated unit of the azospirillum brasilense sr75 o-specific polysaccharide and homology of the lps loci in the plasmids of azospirillum brasilense strains sr75 and sp245]. | the structural identity of the repeated unit in o-specific polysaccharides (opss) present in the outer membrane of strain sr75 of the bacterium azospirillum brasilense, isolated from wheat rhizosphere in saratov oblast, and the opss of previously studied a. brasilense strain sp245, isolated from surface-sterilized wheat roots in brazil, has been demonstrated. plasmid profiles, dna restriction, and hybridization assays suggested that a. brasilense strains sr75 and sp245 have different genomic str ... | 2005 | 16315981 |
| cloning, expression, and characterization of bacterial l-arabinose 1-dehydrogenase involved in an alternative pathway of l-arabinose metabolism. | azospirillum brasiliense converts l-arabinose to alpha-ketoglutarate via five hypothetical enzymatic steps. we purified and characterized l-arabinose 1-dehydrogenase (ec 1.1.1.46), catalyzing the conversion of l-arabinose to l-arabino-gamma-lactone as an enzyme responsible for the first step of this alternative pathway of l-arabinose metabolism. the purified enzyme preferred nadp+ to nad+ as a coenzyme. kinetic analysis revealed that the enzyme had high catalytic efficiency for both l-arabinose ... | 2006 | 16326697 |
| cultivation factors and population size control the uptake of nitrogen by the microalgae chlorella vulgaris when interacting with the microalgae growth-promoting bacterium azospirillum brasilense. | growth of and the capacity to take up nitrogen in the freshwater microalgae chlorella vulgaris were studied while varying the concentrations of ammonium and nitrate, the ph and the source of carbon in a synthetic wastewater growth medium when co-immobilized in alginate beads with the microalgae growth-promoting bacterium azospirillum brasilense. analyses of 29 independent experiments showed that co-immobilization of the microalgae with a. brasilense could result in two independent phenomena dire ... | 2005 | 16332319 |
| effects of partial o(2) pressure, partial co(2) pressure, and agitation on growth kinetics of azospirillum lipoferum under fermentor conditions. | azospirillum lipoferum crt1 was grown in batch cultures under standard conditions at 85% saturation of dissolved oxygen (do) and 30-g/liter glucose concentrations. kinetic studies revealed nutritional limitations of growth and the presence of an initial lag phase prior to consumption of glucose. the influences of various gaseous environments and shear stress on growth, i.e., various conditions of agitation-aeration, were characterized. faster growth in the first stages of the culture and shorter ... | 1990 | 16348331 |
| characterization of azospirillum isolated from nitrogen-fixing roots of harvested sorghum plants. | root segments of harvested sorghum plants had acetylene reduction activity ranging from 11 to 61 nmol of ethylene formed per h per g (dry weight). five strains of azospirillum brasilense sp. nov. were isolated from root segments. | 1979 | 16345484 |
| effect of endosulfan on azospirillum lipoferum growth, morphology, nitrogenase activity, and protein binding. | the organochlorine thiodan ce inhibited growth and nitrogenase activity of azospirillum lipoferum. the active ingredient, endosulfan, was nonspecifically bound to proteins and mainly adsorbed to the cell envelope with small amounts transported into cytosol. the involvement of the external membrane and cyst formation in protection against hazardous substances is discussed. | 1992 | 16348777 |
| association of azospirillum with grass roots. | the association between grass roots and azospirillum brasilense sp 7 was investigated by the fahraeus slide technique, using nitrogen-free medium. young inoculated roots of pearl millet and guinea grass produced more mucilaginous sheath (mucigel), root hairs, and lateral roots than did uninoculated sterile controls. the bacteria were found within the mucigel that accumulated on the root cap and along the root axes. adherent bacteria were associated with granular material on root hairs and fibril ... | 1980 | 16345490 |
| plant yield and nitrogen content of a digitgrass in response to azospirillum inoculation. | two australian soils, a vertisol (ph 6.8, 0.299% n) and a sandy yellow podzol (ph 6.2, 0.042% n), were used with digitgrass, digitaria sp. x46-2 (pi 421785), in a growth room experiment. comparisons were made between plants inoculated with live and autoclaved bacterial suspensions of australian and brazilian isolates of azospirillum brasilense. seedlings were inoculated on days 10 and 35. acetylene-reducing activity was measured five times during the experiment. dry matter yields of the digitgra ... | 1981 | 16345707 |
| isolation of azospirillum lipoferum 4t tn5 mutants affected in melanization and laccase activity. | azospirillum lipoferum 4t has original properties such as nonmotility, melanin synthesis, and laccase activity. following random tn5 mutagenesis in a. lipoferum 4t, we obtained 10 mutants which were affected in melanization and laccase activity. the class 1 mutants, with intermediate levels of laccase activity, showed some coloration; the class 2 mutants, which were completely negative for laccase activity, were also colorless. the tn5 localization on the chromosome or on the cryptic 300-mda pla ... | 1994 | 16349390 |
| mode of utilization of amino acids as growth substrates by azospirillum brasilense. | the study was undertaken to analyze the rate of uptake and utilization of various amino acids by azospirillum brasilense sp81 (rg) in a basal mineral salts solution under non-nitrogen fixing condition. these amino acids including other nitrogenous compounds were tested for both n- and c-sources. the kinetic constants (km and vmax) of uptake of some amino acids (e.g. lysine, arginine, proline, glutamine and glutamic acid) were exploited using a hanes-woolf plot, and discussed in the context of ni ... | 2005 | 16359132 |
| improved medium for isolation of azospirillum spp. | colonies of azospirillum spp. could be readily distinguished from colonies of other diazotrophs by scarlet coloration in culture media in which congo red was included. | 1982 | 16346123 |
| tgge analysis of the diversity of ammonia-oxidizing and denitrifying bacteria in submerged filter biofilms for the treatment of urban wastewater. | the spatial and temporal diversity of the bacterial community-forming biofilms in a pilot-scale submerged biofilter used for the treatment of urban wastewater was analyzed by a temperature-gradient gel electrophoresis (tgge) approach. tgge profiles based on partial sequence of the 16s rrna gene showed that the community composition of the biofilms remained fairly stable along the column system and during the whole time of operation of the biofilter (more than 1 year). community-profiling based o ... | 2006 | 16391923 |
| growth dynamics of azospirillum lipoferum at steady and transitory states in the presence of nh. | the objective of this paper was to study the adaptation dynamics and biochemical response of azospirillum lipoferum grown in a continuous culture at various environmental shifts. | 2006 | 16430505 |
| enhanced mineral uptake by zea mays and sorghum bicolor roots inoculated with azospirillum brasilense. | inoculation of corn (zea mays) seeds with azospirillum brasilense strain cd or sp 7 significantly enhanced (30 to 50% over controls) the uptake of no(3), k, and h(2)po(4) into 3- to 4-day- and 2-week-old root segments. no gross changes in root morphology were observed; altered cell arrangement in the outer four or five layers of the cortex was seen in photomicrographs of cross sections of inoculated corn roots. the surface activity involved in ion uptake probably increased, as shown by the darke ... | 1983 | 16346311 |
| cloning and characterization of a fur homologue from azospirillum brasilense sp7. | a homologue of the ferric uptake regulator gene, fur, was identified from a azospirillum brasilense sp7 genomic dna clone. experiments performed with transcriptional lacz fusions demonstrated that the a. brasilense fur homologue regulated the expression of two fur regulated escherichia coli genes: fiu (ferric iron uptake) and fhuf (ferric hydroxamate uptake). a differential regulation by the cognate fur and the heterologous fur homologue in response to the iron status of the growth medium was al ... | 2006 | 16450071 |
| identification of nif genes in n2-fixing bacterial strains isolated from rice fields along the yangtze river plain. | the aim of this research was to identify nifh and nifhdkye ' genes in twenty strains of n2-fixing heterotrophic bacteria isolated from rice fields in the yangtze river plain. southern hybridization of the total dna from each strain was performed with the klebsiella pneumoniae nifhdkye ' gene probe (6.2 kb eco ri fragment from psa30) and the azospirillum brasilense nifh gene probe (0.6 kb eco ri-hin diii fragment from phu8). we found that eco ri fragments of total dna from aeromonas hydrophila hy ... | 2006 | 16463319 |
| n(2) fixation by azospirillum brasilense and its incorporation into host setaria italica. | growth and nitrogen fixation were followed during the life cycle of setaria italica (foxtail millet) inoculated with azospirillum brasilense in controlled-environment growth chambers. the plants were fertilized at seeding with a limiting amount of combined nitrogen and maintained with an n-free mineral solution. during maturation of the plants, substantial nitrogenase activity, measured by acetylene reduction, developed in the rhizosphere, with total fixation estimated to be equivalent to 20% of ... | 1983 | 16346386 |
| root hair deformation, bacterial attachment, and plant growth in wheat-azospirillum associations. | seven azospirillum strains induced more deformation of root hairs of wheat than did strains of rhizobium leguminosarum, azotobacter chroococcum, or escherichia coli. azospirillum sp. strain sp245 caused the most deformation. strain sp245 (isolated from surface sterile roots of wheat) and strain sp7 (isolated from the rhizosphere of a forage grass) were compared with regard to their effects on root hair deformation, their attachment to roots, and their effects on the growth of four wheat cultivar ... | 1984 | 16346680 |
| comparative study of substrates and inhibitors of azospirillum lipoferum and pyricularia oryzae laccases. | azospirillum lipoferum and pyricularia oryzae laccases were compared, using several substrates and inhibitors. sixteen phenolic or nonphenolic compounds were found to be substrates of both fungal and bacterial laccases. in the presence of different phenol oxidase inhibitors, p. oryzae and a. lipoferum laccase activities had similar properties. | 1995 | 16534964 |
| straw and xylan utilization by pure cultures of nitrogen-fixing azospirillum spp. | azospirillum spp. were shown to utilize both straw and xylan, a major component of straw, for growth with an adequate combined n supply and also under n-limiting conditions. for most strains examined, a semisolid agar medium was satisfactory, but several strains appeared to be capable of slow metabolism of the agar. subsequently, experiments were done with acid-washed sand supplemented with various carbon sources. in these experiments, authenticated laboratory strains, and all 16 recent field is ... | 1985 | 16346730 |
| promotion of nod gene inducers and nodulation in common bean (phaseolus vulgaris) roots inoculated with azospirillum brasilense cd. | inoculation of phaseolus vulgaris with azospirillum brasilense cd promoted root hair formation in seedling roots and significantly increased total and upper nodule numbers at different concentrations of rhizobium inoculum. in experiments carried out in a hydroponic system, a. brasilense caused an increase in the secretion of nod gene-inducing flavonoids, as was observed by nod gene induction assays of root exudates fractionated by high-performance liquid chromatography. possible mechanisms invol ... | 1996 | 16535388 |
| [effect of congo red on the motility of the bacterium azospirillum brasilense]. | in semiliquid laboratory media, the bacterium azospirillum brasilense migrates with the formation of swarming rings. it is demonstrated that adsorption of the sulfonated azodye congo red confers on a. brasilense the ability to consistently spread in a semiliquid agar and form microcolonies. spontaneous variants of a. brasilense with rapid swarming are described, as well as variants that swarm in the presence of congo red. it is assumed that at least two types of compounds are formed, which are ( ... | 2006 | 16579446 |
| inoculation effects of pseudomonas putida, gluconacetobacter azotocaptans, and azospirillum lipoferum on corn plant growth under greenhouse conditions. | alcohol production from corn is gaining importance in ontario, canada, and elsewhere. a major cost of corn production is the cost of chemical fertilizers and these continue to increase in price. the competitiveness of alcohol with fossil fuels depends on access to low-cost corn that allows growers to earn a sustainable income. in this study we set out to determine if we can identify root-associated microorganisms from ontario-grown corn that can enhance the nutrient flow to corn roots, directly ... | 2006 | 16598630 |
| interaction of azospirillum and rhizobium strains leading to inhibition of nodulation. | rhizobium-azospirillum interactions during establishment of rhizobium-clover symbiosis were studied. when mixed cultures of azospirillum and rhizobium trifolii strains were simultaneously inoculated onto clover plants, no nodulation by r. trifolii was observed. r. trifolii anu1030, which nodulated clover plants without attacking root hairs, i.e., does not cause root hair curling (hac), did not show inhibition of nodulation when inoculated together with azospirillum strains. isolation of bacteria ... | 1985 | 16346773 |
| cellulose decomposition and associated nitrogen fixation by mixed cultures of cellulomonas gelida and azospirillum species or bacillus macerans. | mixed cultures of cellulomonas gelida plus azospirillum lipoferum or azospirillum brasilense and c. gelida plus bacillus macerans were shown to degrade cellulose and straw and to utilize the energy-yielding products to fix atmospheric nitrogen. this cooperative process was followed over 30 days in sand-based cultures in which the breakdown of 20% of the cellulose and 28 to 30% of the straw resulted in the fixation of 12 to 14.6 mg of n per g of cellulose and 17 to 19 mg of n per g of g straw con ... | 1985 | 16346898 |
| nitrogen fixation associated with development and localization of mixed populations of cellulomonas sp. and azospirillum brasilense grown on cellulose or wheat straw. | mixed cultures of cellulomonas sp. and azospirillum brasilense were grown with straw or cellulose as the carbon source under conditions favoring the fixation of atmospheric nitrogen. rapid increases in cell numbers, up to 10 cells per g of substrate, were evident after 4 and 5 days of incubation at 30 degrees c for cellulose and straw, respectively. nitrogen fixation (detected by acetylene reduction measured on parallel cultures) commenced after 2 and 4 days of incubation for straw and cellulose ... | 1986 | 16347042 |
| comparison of two cellulomonas strains and their interaction with azospirillum brasilense in degradation of wheat straw and associated nitrogen fixation. | a mutant strain of cellulomonas sp. cs1-17 was compared with cellulomonas gelida 2480 as the cellulolytic component of a mixed culture which was responsible for the breakdown of wheat straw to support asymbiotic nitrogen fixation by azospirillum brasilense sp7 (atcc 29145). cellulomonas sp. strain csi-17 was more efficient than was c. gelida in cellulose breakdown at lower oxygen concentrations and, in mixed culture with a. brasilense, it supported higher nitrogenase activity (c(2)h(2) reduction ... | 1986 | 16347043 |
| phylogeny of the 1-aminocyclopropane-1-carboxylic acid deaminase-encoding gene acds in phytobeneficial and pathogenic proteobacteria and relation with strain biogeography. | deamination of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (acc) is a key plant-beneficial trait found in plant growth-promoting rhizobacteria (pgpr) and phytosymbiotic bacteria, but the diversity of the corresponding gene (acds) is poorly documented. here, acds sequences were obtained by screening putative acc deaminase sequences listed in databases, based on phylogenetic properties and key residues. in addition, acds was sought in 71 proteobacterial strains by pcr amplificatio ... | 2006 | 16689877 |
| close association of azospirillum and diazotrophic rods with different root zones of kallar grass. | [this corrects the article on p. 522 in vol. 52.]. | 1987 | 16347260 |
| enzyme-linked immunosorbent assay for specific identification and enumeration of azospirillum brasilense cd. in cereal roots. | the enzyme-linked immunosorbent assay is suggested as a reliable, sensitive, and highly specific method for the identification and enumeration of azospirillum brasilense cd. as few as 10 cfu/ml can be practically identified by this method. at higher bacterial numbers, sensitivity increased linearly up to 5 x 10 cfu/ml, yielding useful standard curves. no cross-reaction was found either with different closely related azospirillum strains or with other rhizosphere bacteria. the method allows for a ... | 1987 | 16347284 |
| transposon mutagenesis of azospirillum brasilense and azospirillum lipoferum: physical analysis of tn5 and tn5-mob insertion mutants. | tn5-induced insertion mutants were generated in azospirillum brasilense sp7 and a. lipoferum spbr17 by mating with escherichia coli strains carrying suicide plasmid vectors. the sources of tn5 were the suicide plasmids pgs9 and psup2021. kanamycin-resistant azospirillum colonies appeared from crosses with e. coli at maximum frequencies of 10 per recipient cell. transposon tn5 also conferred streptomycin resistance on azospirillum colonies as was observed earlier for rhizobium sp. eight tn5-induc ... | 1987 | 16347289 |
| plant cell wall carbohydrates as substrates for azospirillum brasiliense. | carbohydrate components (simple sugars and polysaccharides) of cell walls of pearl millet (pennisetum americanum l., cv. gahi) were studied as potential substrates for the root-associated diazotroph azospirillum brasiliense sp. 7. simple sugars were utilized, but no evidence was obtained to support the suggestion that the polysaccharide components tested might serve as substrates for growth following hydrolysis by the associated azospirilla. | 1987 | 16347490 |
| auxin signaling in plant defense. | | 2006 | 16840680 |
| phase variation and genomic architecture changes in azospirillum. | the plant growth-promoting rhizobacterium azospirillum lipoferum 4b generates in vitro at high frequency a stable nonswimming phase variant designated 4v(i), which is distinguishable from the wild type by the differential absorption of dyes. the frequency of variants generated by a reca mutant of a. lipoferum 4b was increased up to 10-fold. the pleiotropic modifications characteristic of the phase variant are well documented, but the molecular processes involved are unknown. here, the objective ... | 2006 | 16855225 |
| analysis of indole-3-acetic acid and related indoles in culture medium from azospirillum lipoferum and azospirillum brasilense. | analysis of neutral and acidic ethyl acetate extracts from culture medium of azospirillum brasilense 703ebc by high-performance liquid chromatography (hplc) and combined gas chromatography-mass spectrometry demonstrated the presence of indole-3-acetic acid (iaa), indole-3-ethanol, indole-3-methanol, and indole-3-lactic acid. iaa in media of 20 strains of a. brasilense and azospirillum lipoferum was analyzed quantitatively by both the colorimetric salkowski assay and hplc-based isotopic dilution ... | 1988 | 16347781 |
| floc formation by azospirillum lipoferum grown on poly-beta-hydroxybutyrate. | azospirillum lipoferum rg6xx was grown under conditions similar to those resulting in encystment of azotobacter spp. a. lipoferum produced cells of uniform shape when grown on nitrogen-free beta-hydroxybutyrate agar. cells accumulated poly-beta-hydroxybutyrate and often grew as chains or filaments that eventually lost motility and formed capsules. within 1 week, vegetative a. lipoferum inocula were converted into microflocs arising from filaments or chains. cells within microflocs were pleomorph ... | 1988 | 16347792 |
| intact soil-core microcosms for evaluating the fate and ecological impact of the release of genetically engineered microorganisms. | intact soil-core microcosms were studied to determine their applicability for evaluating the transport, survival, and potential ecosystem effects of genetically engineered microorganisms before they are released into the environment. soil-core microcosms were planted with wheat and maize seeds and inoculated with azospirillum lipoferum spbr17 and sprg20a tn5 mutants, respectively. microcosm leachate, rhizosphere soil, plant endorhizosphere, insects, and xylem exudate were sampled for a. lipoferu ... | 1989 | 16347823 |
| n(2) fixation by bacteria associated with maize roots at a low partial o(2) pressure. | nitrogen fixation by bacteria associated with roots of intact maize plants was measured by exposing the roots to n(2) at a partial o(2) pressure (po(2)) of 2 or 10 kpa. the plants were grown in a mixture of weswood soil and sand and then transferred to plastic cylinders containing an n-free plant nutrient solution. the solution was sparged continuously with a mixture of air and n(2) at a po(2) of 2 or 10 kpa. acetylene reduction was measured after the roots were exposed to the low po(2) overnigh ... | 1989 | 16347968 |
| identification, cloning and characterization of cysk, the gene encoding o-acetylserine (thiol)-lyase from azospirillum brasilense, which is involved in tellurite resistance. | o-acetylserine (thiol)-lyase (cysteine synthase) was purified from azospirillum brasilense sp7. after hydrolysis of the purified protein, amino acid sequences of five peptides were obtained, which permitted the cloning and sequencing of the cysk gene. the deduced amino acid sequence of cysteine synthase exhibited homology with several putative proteins from alpha- and gammaproteobacteria. azospirillum brasilense sp7 cysk exhibited 58% identity (72% similarity) with escherichia coli k12 and salmo ... | 2006 | 16907731 |
| intracellular location and o(2) sensitivity of uptake hydrogenase in azospirillum spp. | uptake hydrogenase activity of azospirillum brasilense in vitro (cell-free extract) was very much more sensitive to o(2) than was that of a. amazonense, and the o(2) pressure optima for uptake hydrogenase activities were 0.01 and 0.4 to 3 kpa for a. brasilense and a. amazonense, respectively. the addition of superoxide dismutase did not increase uptake hydrogenase activity of a. brasilense either in vivo or in vitro. the o(2) uptake rates of a. brasilense and a. amazonense were nearly the same. ... | 1989 | 16348011 |
| nitrogen fixation in continuous culture with nh(4)cl-containing media. | n balance and n dilution were determined from growth of azospirillum brasilense sp7 and two unidentified gram-negative nitrogen-fixing microorganisms in continuous culture supplied with nh(4)cl. at the 1.1 and 2.2 mm nh(4)cl steady states (n-to-c ratios of 1:68 and 1:34, respectively), the organisms grew with nh(4)cl and n(2) as n sources simultaneously under carbon limitation. no ammonium could be detected in the supernatant of these cultures. | 1990 | 16348161 |
| interaction of rhizosphere bacteria, fertilizer, and vesicular-arbuscular mycorrhizal fungi with sea oats. | plants must be established quickly on replenished beaches in order to stabilize the sand and begin the dune-building process. the objective of this research was to determine whether inoculation of sea oats (uniola paniculata l.) with bacteria (indigenous rhizosphere bacteria and n(2) fixers) alone or in combination with vesicular-arbuscular mycorrhizal fungi would enhance plant growth in beach sand. at two fertilizer-n levels, klebsiella pneumoniae and two azospirillum spp. did not provide the p ... | 1990 | 16348236 |
| preferential osmolyte accumulation: a mechanism of osmotic stress adaptation in diazotrophic bacteria. | a common cellular mechanism of osmotic-stress adaptation is the intracellular accumulation of organic solutes (osmolytes). we investigated the mechanism of osmotic adaptation in the diazotrophic bacteria azotobacter chroococcum, azospirillum brasilense, and klebsiella pneumoniae, which are adversely affected by high osmotic strength (i.e., soil salinity and/or drought). we used natural-abundance c nuclear magnetic resonance spectroscopy to identify all the osmolytes accumulating in these strains ... | 1990 | 16348295 |
| nh(4)-excreting azospirillum brasilense mutants enhance the nitrogen supply of a wheat host. | spontaneous ethylenediamine-resistant mutants of azospirillum brasilense were selected on the basis of their excretion of nh(4). two mutants exhibited no repression of their nitrogenase enzyme systems in the presence of high (20 mm) concentrations of nh(4). the nitrogenase activities of these mutants on nitrogen-free minimal medium were two to three times higher than the nitrogenase activity of the wild type. the mutants excreted substantial amounts of ammonia when they were grown either under o ... | 1991 | 16348569 |
| short term effects of glomus claroideum and azospirillum brasilense on growth and root acid phosphatase activity of carica papaya l. under phosphorus stress. | arbuscular mycorrhizal fungi (amf) are able to increase root enzymatic activity of acid and alkaline phosphatases. however, the role of amf on phosphatase activity has not been reported in papaya (carica papaya l.), which is frequently established at places with soil phosphorus (p) deficiencies. the goals of this research were to determine the effect of glomus claroideum (gc), and plant growth promoting rhizobacterium azospirillum brasilense strain vs7 [ab]) on root phosphatase activity and seed ... | 2002 | 17061513 |
| n-acyl-homoserine lactone-mediated quorum-sensing in azospirillum: an exception rather than a rule. | forty azospirillum strains were tested for their ability to synthesize n-acyl-homoserine lactones (ahls). ahl production was detected for four strains belonging to the lipoferum species and isolated from a rice rhizosphere. ahl molecules were structurally identified for two strains: azospirillum lipoferum tvv3 produces 3o,c(8)-hsl (n-3-oxo-octanoyl-homoserine-lactone), c(8)-hsl (n-3-octanoyl-homoserine-lactone), 3o,c(10)-hsl (n-3-oxo-decanoyl-homoserine-lactone), 3oh,c(10)-hsl (n-3-hydroxy-decan ... | 2006 | 17064258 |
| chemotaxis of azospirillum species to aromatic compounds. | chemotaxis of azospirillum lipoferum sp 59b and azospirillum brasilense sp 7 and sp cd to malate and to the aromatic substrates benzoate, protocatechuate, 4-hydroxybenzoate, and catechol was assayed by the capillary method and direct cell counts. a. lipoferum required induction by growth on 4-hydroxybenzoate for positive chemotaxis to this compound. chemotaxis of azospirillum spp. to all other substrates did not require induction. maximum chemotactic responses for most aromatic compounds occurre ... | 1993 | 16349041 |
| root-to-root travel of the beneficial bacterium azospirillum brasilense. | the root-to-root travel of the beneficial bacterium azospirillum brasilense on wheat and soybean roots in agar, sand, and light-textured soil was monitored. we used a motile wild-type (mot) strain and a motility-deficient (mot) strain which was derived from the wild-type strain. the colonization levels of inoculated roots were similar for the two strains. mot cells moved from inoculated roots (either natural or artificial roots in agar, sand, or light-textured soil) to noninoculated roots, where ... | 1994 | 16349297 |
| adp-ribosylation of dinitrogenase reductase in azospirillum brasilense is regulated by amtb-dependent membrane sequestration of drag. | nitrogen fixation in some diazotrophic bacteria is regulated by mono-adp-ribosylation of dinitrogenase reductase (nifh) that occurs in response to addition of ammonium to the extracellular medium. this process is mediated by dinitrogenase reductase adp-ribosyltransferase (drat) and reversed by dinitrogenase reductase glycohydrolase (drag), but the means by which the activities of these enzymes are regulated are unknown. we have investigated the role of the p(ii) proteins (glnb and glnz), the amm ... | 2006 | 16359338 |
| characterization of two trpe genes encoding anthranilate synthase alpha-subunit in azospirillum brasilense. | the previous report from our laboratory has recently identified a new trpe gene (termed trpe2) which exists independently in azospirillum brasilense yu62. in this study, amplification of trpe(g) (termed trpe1(g) here) confirmed that there are two copies of trpe gene, one trpe being fused into trpg while the other trpe existed independently. this is the first report to suggest that two copies of the trpe gene exist in this bacterium. comparison of the nucleotide sequence demonstrated that putativ ... | 2006 | 16430864 |
| cloning, sequencing, and characterization of the azospirillum brasilense fhue gene. | the fhue gene of escherichia coli encodes the fhue protein, which is a receptor protein in the coprogen-mediated siderophore iron-transport system. a fhue gene homologue from azospirillum brasilense, a nitrogen-fixing soil bacterium that lives in association with the roots of cereal grasses, was cloned, sequenced, and characterized. the a. brasilense fhue encodes a protein of 802 amino acids with a predicted molecular weight of approximately 87 kda. the deduced amino-acid sequence showed a high ... | 2006 | 16502288 |
| in situ localization of azospirillum brasilense in the rhizosphere of wheat with fluorescently labeled, rrna-targeted oligonucleotide probes and scanning confocal laser microscopy. | the colonization of wheat roots by azospirillum brasilense was used as a model system to evaluate the utility of whole-cell hybridization with fluorescently labeled, rrna-targeted oligonucleotide probes for the in situ monitoring of rhizosphere microbial communities. root samples of agar- or soil-grown 10- and 30-day-old wheat seedlings inoculated with different strains of a. brasilense were hybridized with a species-specific probe for a. brasilense, a probe hybridizing to alpha subclass proteob ... | 1995 | 16534951 |
| genetic analysis of a novel pathway for d-xylose metabolism in caulobacter crescentus. | genetic data suggest that the oligotrophic freshwater bacterium caulobacter crescentus metabolizes d-xylose through a pathway yielding alpha-ketoglutarate, comparable to the recently described l-arabinose degradation pathway of azospirillum brasilense. enzymes of the c. crescentus pathway, including an nad(+)-dependent xylose dehydrogenase, are encoded in the xylose-inducible xylxabcd operon (cc0823-cc0819). | 2007 | 17172333 |
| survival of azospirillum brasilense in the bulk soil and rhizosphere of 23 soil types. | the survival of azospirillum brasilense cd and sp-245 in the rhizosphere of wheat and tomato plants and in 23 types of plant-free sterilized soils obtained from a wide range of environments in israel and mexico was evaluated. large numbers of a. brasilense cells were detected in all the rhizospheres tested, regardless of soil type, bacterial strain, the origin of the soil, or the amount of rainfall each soil type received prior to sampling. survival of a. brasilense in soils without plants diffe ... | 1995 | 16535030 |
| increase in dry weight and total nitrogen content in zea mays and setaria italica associated with nitrogen-fixing azospirillum spp. | the association between nitrogen-fixing bacteria from the genus azospirillum and the grasses zea mays and setaria italica was investigated in sterilized leonard-jar assemblies. nitrogen-fixing bacteria isolated from cynodon dactylon roots in israel and azospirillum brasilense (sp-7, sp-80, and cd) were examined. c(2)h(2) reduction activity was detected in systems containing 0.0 to 0.08 but not in those containing 0.16 gram per liter nh(4)no(3). the organisms tested significantly increased plant ... | 1980 | 16661514 |
| targeted engineering of azospirillum brasilense sm with indole acetamide pathway for indoleacetic acid over-expression. | rhizospheric bacterial strains are known to produce indole-3-acetic acid (iaa) through different pathways, and such iaa may be beneficial to plants at low concentrations. iaa biosynthesis by a natural isolate of azospirillum brasilense sm was studied and observed to be tryptophan-inducible and -dependent in nature. while our work demonstrated the operation of the indole pyruvic acid pathway, the biochemical and molecular evidence for the genes of the indole acetamide (iam) pathway were lacking i ... | 2006 | 17215899 |
| identification of diazotrophs in the culturable bacterial community associated with roots of lasiurus sindicus, a perennial grass of thar desert, india. | lasiurus sindicus is a highly nutritive, drought-tolerant, perennial grass that is endemic to the thar desert of rajasthan, india. analysis of 16s rrna coding genes of the bacterial isolates enriched in nitrogen-free semisolid medium, from the surface-sterilized roots of l. sindicus, showed predominance of gram-negative over gram-positive bacteria. according to comparative sequence analysis of 16s rdna sequence data, gram-positive bacteria with low gc content (staphylococcus warneri and bacillus ... | 2007 | 17264993 |
| identification of gibberellins a(1), a(3), and iso-a(3) in cultures of azospirillum lipoferum. | gibberellins a(1), a(3), and iso-a(3) were identified from aseptic cultures of azospirillum lipoferum strain op 33 by capillary gas chromatography-mass spectrometry (gc-ms) and gc-ms-selected ion monitoring. there were 20 to 40 picograms (in ga(3) equivalents, estimated from bioassay) of gibberellins a(1) and a(3) per milliliter of cell culture (containing 10(9) cells). | 1989 | 16666766 |
| tomato genotype and azospirillum inoculation modulate the changes in bacterial communities associated with roots and leaves. | to evaluate the effect of plant variety and azospirillum brasilense inoculation on the microbial communities colonizing roots and leaves of tomato (lycopersicon esculentum mill.) plants. | 2007 | 17309628 |
| factors affecting the attachment of rhizospheric bacteria to bean and soybean roots. | the plant rhizosphere is an important soil ecological environment for plant-microorganism interactions, which include colonization by a variety of microorganisms in and around the roots that may result in symbiotic, endophytic, associative, or parasitic relationships within the plant, depending on the type of microorganisms, soil nutrient status, and soil environment. rhizosphere competence may be attributable to the differences in the extent of bacterial attachment to the root surface. we prese ... | 2006 | 16684104 |
| azospirillum melinis sp. nov., a group of diazotrophs isolated from tropical molasses grass. | fifteen bacterial strains isolated from molasses grass (melinis minutiflora beauv.) were identified as nitrogen-fixers by using the acetylene-reduction assay and pcr amplification of nifh gene fragments. these strains were classified as a unique group by insertion sequence-pcr fingerprinting, sds-page protein patterns, dna-dna hybridization, 16s rrna gene sequencing and morphological characterization. phylogenetic analysis of the 16s rrna gene indicated that these diazotrophic strains belonged t ... | 2006 | 16738102 |
| characterization of selected groups of microorganisms occurring in soil rhizosphere and phyllosphere of oats. | studies were carried out on the microflora of phyllosphere and soil rhizosphere of hulled (chwat variety) and naked (akt variety) oats. the material taken for study embraced samples of leaves and soil rhizosphere taken from cultivations differing in extent of nitrogen fertilization. the studies involved determination of total number of aerobic heterotrophic bacteria belonging to the genus pseudomonas and microscopic hyphal fungi. qualitative determinations focused on bacteria belonging to the ge ... | 2006 | 17338275 |
| relationship between in vitro enhanced nitrogenase activity of an azospirillum brasilense sp7 mutant and its growth-promoting activities in situ. | in this work, we further analyzed an azospirillum brasilense sp7 mutant (sp7::tn5-33) showing a pleiotrophic phenotype due to a tn5 insertion into an open reading frame of 840 bp (orf280). the deduced amino acid sequence of this region has high similarity to a family of universal stress proteins. because the most interesting property exhibited by the sp7::tn5-33 mutant was an enhanced in vitro nitrogen fixation activity, we addressed the question of whether it could benefit the host plant. we fo ... | 2006 | 16775786 |
| plant-growth-promoting compounds produced by two agronomically important strains of azospirillum brasilense, and implications for inoculant formulation. | we evaluated phytohormone and polyamine biosynthesis, siderophore production, and phosphate solubilization in two strains (cd and az39) of azospirillum brasilense used for inoculant formulation in argentina during the last 20 years. siderophore production and phosphate solubilization were evaluated in a chemically defined medium, with negative results. indole 3-acetic acid (iaa), gibberellic acid (ga(3)), and abscisic acid (aba) production were analyzed by gas chromatography-mass spectrometry. e ... | 2007 | 17345081 |
| enumeration, isolation and identification of diazotrophs from korean wetland rice varieties grown with long-term application of n and compost and their short-term inoculation effect on rice plants. | this study has been aimed (i) to isolate and identify diazotrophs from korean rice varieties; (ii) to examine the long-term effect of n and compost on the population dynamics of diazotrophs and (iii) to realize the shot-term inoculation effect of these diazotrophs on rice seedlings. | 2007 | 17381741 |
| a novel alpha-ketoglutaric semialdehyde dehydrogenase: evolutionary insight into an alternative pathway of bacterial l-arabinose metabolism. | azospirillum brasilense possesses an alternative pathway of l-arabinose metabolism, which is different from the known bacterial and fungal pathways. in a previous paper (watanabe, s., kodaki, t., and makino, k. (2006) j. biol. chem. 281, 2612-2623), we identified and characterized l-arabinose 1-dehydrogenase, which catalyzes the first reaction step in this pathway, and we cloned the corresponding gene. here we focused on the fifth enzyme, alpha-ketoglutaric semialdehyde (alphakgsa) dehydrogenase ... | 2006 | 16835232 |
| adenosine diphosphate ribosylation of dinitrogenase reductase and adenylylation of glutamine synthetase control ammonia excretion in ethylenediamine-resistant mutants of azospirillum brasilense sp7. | azospirillum brasilense is a nitrogen-fixing, root-colonizing bacterium that brings about plant-growth-promoting effects mainly because of its ability to produce phytohormones. ethylenediamine (eda)-resistant mutants of a. brasilense were isolated and screened for their higher ability to decrease acetylene and release ammonia in the medium. one of the mutants showed considerably higher levels of acetylene decrease and ammonia excretion. nitrogenase activity of this mutant was relatively resistan ... | 2006 | 16972125 |
| bacterial lateral flagella: an inducible flagella system. | flagella are complex surface organelles that allow bacteria to move towards favourable environments and that contribute to the virulence of pathogenic bacteria through adhesion and biofilm formation on host surfaces. there are a few bacteria that possess functional dual flagella systems, such as vibrio parahaemolyticus, some mesophilic aeromonas spp., rhodospirillum centenum and azospirillum brasilense. these bacteria are able to express both a constitutive polar flagellum required for swimming ... | 2006 | 16978346 |
| functional expression of an acyl carrier protein (acp) from azospirillum brasilense alters fatty acid profiles in escherichia coli and brassica juncea. | acyl carrier protein (acp) is a central cofactor for de novo fatty acid synthesis, acyl chain modification and chain-length termination during lipid biosynthesis in living organisms. although the structural and functional organization of the acps in bacteria and plant are highly conserved, the individual acp is engaged in the generation of sets of signature fatty acids required for specific purpose in bacterial cells and plant tissues. realizing the fact that the bacterial acp being originated e ... | 2007 | 17466529 |
| [wheat lectin as a factor in plant-microbial communication and a stress response protein]. | wheat lectin (wheat germ agglutinin, wga), a representative of a broad group of cereal lectins, is excreted by plant roots into the surrounding medium and interacts with both pathogenic microflora and growth-stimulating rhizobacteria. wga was found to serve as a molecular signal for the rhizobacterium azospirillum brasilense, which forms endophytic and associative symbioses with wheat plants. the bacterial response to the lectin was pleiotropic: wga at concentrations from 10(-10) to 10(-6) m exe ... | 2006 | 17025182 |
| attachment of bacteria to the roots of higher plants. | attachment of soil bacteria to plant cells is supposedly the very early step required in plant-microbe interactions. attachment also is an initial step for the formation of microbial biofilms on plant roots. for the rhizobia-legume symbiosis, various mechanisms and diverse surface molecules of both partners have been proposed to mediate in this process. the first phase of attachment is a weak, reversible, and unspecific binding in which plant lectins, a ca(+2)-binding bacterial protein (rhicadhe ... | 2007 | 17521360 |
| [impact of bacterial lectin on functional activity of lymphocytes]. | impact of azospirillum brasilense sp7 lectin with carbohydrate specificity to l-fucose on t- and b-lymphocytes production, activity of il-1alpha, and tnf-alpha was studied in vitro and compared with influence of red kidney bean phytohemagglutinin (pha) on the same parameters. increase of growth of t- and b-cells subpopulations has been shown that point to stimulatory effect of the bacterial lectin. bacterial lectin of a. brasilense also increased synthesis of il-1alpha and tnf-alpha. it has been ... | 2007 | 17523482 |
| root phospholipids in azospirillum-inoculated wheat seedlings exposed to water stress. | azospirillum-plant association is accompanied by biochemical changes in roots which, in turn, promote plant-growth and tolerance to water stress. to shed light on the possible factors underlying these effects, roots from azospirillum brasilense sp245-inoculated triticum aestivum seedlings growing in darkness under osmotic stress were analyzed for phospholipid (pl) composition, fatty acid (fa) distribution profiles and degree of unsaturation of the major pl classes. azospirillum inoculation dimin ... | 2006 | 17123824 |
| cdna-aflp reveals differentially expressed genes related to cell aggregation of azospirillum brasilense. | the response regulatory gene flca controls the differentiation process of azospirillum brasilense from vegetative state to cyst-like forms, both in culture and in association with plants. in contrast to the wild type parental strain sp7, strain sp72002, a tn5 induced flca(-) mutant, does not aggregate, does not differentiate from motile, vibroid cells into nonmotile, cyst-like forms and lacks some of the exopolysaccharide material on its cell surface. here we aimed to identify differentially exp ... | 2006 | 17147763 |
| alterations in seedling vigour and antioxidant enzyme activities in catharanthus roseus under seed priming with native diazotrophs. | an experiment was conducted on catharanthus roseus to study the effect of seed treatments with native diazotrophs on its seedling growth and antioxidant enzyme activities. the treatments had significant influence on various seedling parameters. there is no significant influence on dry matter production with the diazotrophs, azospirillum and azotobacter. however, the vital seedling parameters such as germination percentage and vigour index were improved. azotobacter treatment influenced maximum o ... | 2007 | 17610323 |
| l-arabinose 1-dehydrogenase: a novel enzyme involving in bacterial l-arabinose metabolism. | azospirillum brasiliense converts l-arabinose to alpha-ketoglutarate via five hypothetical enzymatic steps. we purified and characterized l-arabinose 1-dehydrogenase (ec 1.1.1.46) catalyzing conversion of l-arabinose to l-arabino-gamma-lactone as an enzyme involved in the first step of this l-arabinose metabolic pathway. the purified enzyme was preferred nadp+ to nad+ as a coenzyme. kinetic analysis revealed that the enzyme had a high catalytic efficiency for both l-arabinose and d-galactose and ... | 2005 | 17150757 |
| strain-specific salt tolerance and osmoregulatory mechanisms in azospirillum brasilense. | salinity stress inhibits the growth and nitrogen fixation ability of the plant growth-promoting rhizobacterium azospirillum brasilense. five strains of a. brasilense were isolated from the rhizosphere of indian cereals and grasses and identified on the basis of their phenotypic features and 16s rrna gene sequence. the five indian isolates and two standard strains of a. brasilense, sp7 and cd, showed notable differences in growth, acetylene-reducing activity under salt stress, and ability to take ... | 2007 | 17156127 |
| oxygen and redox sensing by two-component systems that regulate behavioral responses: behavioral assays and structural studies of aer using in vivo disulfide cross-linking. | a remarkable increase in the number of annotated aerotaxis (oxygen-seeking) and redox taxis sensors can be attributed to recent advances in bacterial genomics. however, in silico predictions should be supported by behavioral assays and genetic analyses that confirm an aerotaxis or redox taxis function. this chapter presents a collection of procedures that have been highly successful in characterizing aerotaxis and redox taxis in escherichia coli. the methods are described in enough detail to ena ... | 2007 | 17628141 |
| reclassification of roseomonas fauriae rihs et al. 1998 as a later heterotypic synonym of azospirillum brasilense tarrand et al. 1979. | the relatedness of roseomonas fauriae and azospirillum brasilense was investigated using phenotypic methods and dna-dna hybridization. conventional biochemical tests did not differentiate between the two taxa. dna-dna hybridization experiments revealed high values for relatedness between the type strains of these species and suggest that these two taxa constitute a single species. strains previously identified as r. fauriae should be reclassified as a. brasilense, with the name roseomonas fauria ... | 2006 | 17158972 |
| [16s rdna-rflp analysis of structure and diversity of an aerobic microbial community degrading hexachlorobenzene]. | hexachlorobenzene is a chlorinated aromatic hydrocarbon that was widely used as a seed dressing for prevention of fungal growth on crops, and is also a component of fireworks, ammunition, and synthetic rubbers. because of the bioaccumulation and persistence of hexachlorobenzene as well as its potential toxicity, hexachlorobenzene must be removed from environment. the potential for aerobic dechlorination of hexachlorobenzene by a hexachlorobenzene-adapted mixed culture was investigated. an aerobi ... | 2006 | 17172024 |
| alpha-ketoglutaric semialdehyde dehydrogenase isozymes involved in metabolic pathways of d-glucarate, d-galactarate, and hydroxy-l-proline. molecular and metabolic convergent evolution. | azospirillum brasilense possesses an alternative pathway of l-arabinose metabolism in which alpha-ketoglutaric semialdehyde (alphakgsa) dehydrogenase (kgsadh) is involved in the last step, the conversion of alphakgsa to alpha-ketoglutarate. in the preceding studies, we identified a set of metabolic genes of the l-arabinose pathway including the kgsadh gene (watanabe, s., kodaki, t., and makino, k. (2006) j. biol. chem. 281, 2612-2623; watanabe, s., kodaki, t., and makino, k. (2006) j. biol. chem ... | 2007 | 17202142 |
| micropropagation of photinia employing rhizobacteria to promote root development. | an alternative protocol was developed for in vitro propagation of photinia (photinia x fraseri dress), an ornamental shrub, using the plant growth-promoting rhizobacteria (pgpr) azospirillum brasilense and azotobacter chroococcum during rhizogenesis. shoot tips from four-year-old mature plants, cut in spring and summer, were used as initial explants. they were cultured on murashige-skoog (ms) medium with gamborg's vitamins, n(6)-benzyladenine (ba: 11.1 microm) and gibberellic acid (ga(3): 1.3 mi ... | 2007 | 17205338 |
| purification and characterisation of azospirillum brasilense n-truncated ntrx protein. | the ntrx protein has been identified as a transcriptional activator of genes involved in the metabolic control of alternative nitrogen sources, acting as a member of a two-component regulatory system. the in silico analysis of the ntrx amino acid sequence shows that this protein contains an n-terminal receiver domain, a central aaa+ superfamily domain and a c-terminal dna binding domain. to over-express and purify this protein, the ntrx gene of azospirillum brasilense lacking the first eight cod ... | 2007 | 17306559 |
| effects of temperature, nitrogen fertilization, and plant age on nitrogen fixation by setaria italica inoculated with azospirillum brasilense (strain cd). | the association between the nitrogen-fixing bacterium azospirillum brasilense (strain cd) and the grass setaria italica was studied under different environmental and soil conditions. highest acetylene reduction rates in intact plants were observed at the booting stage of setaria (2350 nmol ethylene produced hour(-1) plant(-1)) at 27 c. higher temperatures, up to 32 c, enhanced ethylene reduction. significant increases in shoot dry weight, panicle weight, and length were obtained in inoculated pl ... | 1981 | 16661913 |
| microbial degradation of the biocide polyhexamethylene biguanide: isolation and characterization of enrichment consortia and determination of degradation by measurement of stable isotope incorporation into dna. | to isolate micro-organisms capable of utilizing polyhexamethylene biguanide (phmb) as a sole source of nitrogen, and to demonstrate biodegradation of the biocide. | 2007 | 17897221 |
| changes in motility of the rhizobacterium azospirillum brasilense in the presence of plant lectins. | the plant-beneficial bacterium azospirillum brasilense can swim in liquids and swarm or migrate with the formation of microcolonies in soft media. to get closer to understanding the influence of natural environments on a. brasilense motility, we studied the individual and social movement of the bacterium in the presence of various plant lectins. the lectins with specificity for n-acetyl-beta-d-glucosamine oligomers (wheat germ, solanum tuberosum and ulex europeus agglutinins) decreased a. brasil ... | 2009 | 17317126 |
| azospirillum canadense sp. nov., a nitrogen-fixing bacterium isolated from corn rhizosphere. | a free-living diazotrophic strain, ds2(t), was isolated from corn rhizosphere. polyphasic taxonomy was performed including morphological characterization, biolog analysis, and 16s rrna, cpn60 and nifh gene sequence analyses. 16s rrna gene sequence analysis indicated that strain ds2(t) was closely related to the genus azospirillum (96 % similarity). chemotaxonomic characteristics (dna g+c content 67.9 mol%; q-10 quinone system; major fatty acid 18 : 1omega7c) were also similar to those of the gen ... | 2007 | 17329796 |
| role of cheb and cher in the complex chemotactic and aerotactic pathway of azospirillum brasilense. | it has previously been reported that the alpha-proteobacterium azospirillum brasilense undergoes methylation-independent chemotaxis; however, a recent study revealed cheb and cher genes in this organism. we have constructed cheb, cher, and chebr mutants of a. brasilense and determined that the cheb and cher proteins under study significantly influence chemotaxis and aerotaxis but are not essential for these behaviors to occur. first, we found that although cells lacking cheb, cher, or both were ... | 2006 | 16788185 |
| resolving stoichiometries and oligomeric states of glutamate synthase protein complexes with curve fitting and simulation of electrospray mass spectra. | a complicating factor in analyzing electrospray ionization mass spectra of intact macromolecular heterogeneous protein complexes is the potential overlap of ions from different species present in solution. therefore, it is often not possible to assign all ion signals. with the aim of allowing the more efficient and comprehensive analysis of very complex mass spectra of intact heterogeneous protein complexes we developed a software program: somms. the program uses simple user input parameters tog ... | 2006 | 16862623 |
| pleiotropic physiological effects in the plant growth-promoting bacterium azospirillum brasilense following chromosomal labeling in the clpx gene. | azospirillum brasilense 8-i was chromosomally labeled with green fluorescent protein (gfp) genes, using either the native promoterless gfp gene or the mutant gfpmut2 gene under the transcriptional control of the neomycin phosphate transferase (npt2) promoter inserted into tn5 suicide plasmid vectors. one a. brasilense exconjugant, showing a steady and strong fluorescence following irradiation with 365-nm uv light was characterized in detail. this strain, a. brasilense 8-i-gfp showed increased n( ... | 2006 | 16867140 |
| [chemical composition and immunochemical characteristics of the lipopolysaccharide of nitrogen-fixing rhizobacterium azospirillum brasilense cd]. | the chemical composition of the lipopolysaccharide of the associative diazotrophic rhizobacterium azospirillum brasilense cd has been studied. among the main components of the hydrophobic part of the lipopolysaccharide, we identified 3-hydroxytetradecanoic, hexadecenoic, 3-hydroxyhexadecanoic, hexadecanoic, octadecenoic, and nanodecanoic fatty acids; the carbohydrate part contained rhamnose, galactose, and mannose. polyclonal antibodies against the preparation under study were raised in rabbits. ... | 2006 | 16871806 |
| structure and activity of bacterial community inhabiting rice roots and the rhizosphere. | root-derived carbon provides a major source for microbial production and emission of ch4 from rice field soils. therefore, we characterized the structure and activity of the bacterial community inhabiting rice roots and the rhizosphere. in the first experiment, dna retrieved from rice roots was analysed for bacterial 16s rrna genes using cloning, sequencing and in situ hybridization. in the second experiment, rice plants were pulse-labelled with 13co2 (99% of atom 13c) for 7 days, and the bacter ... | 2006 | 16872399 |
| analysis of microbial community during biofilm development in an anaerobic wastewater treatment reactor. | the formation, structure, and biodiversity of a multispecies anaerobic biofilm inside an upflow anaerobic sludge bed (uasb) reactor fed with brewery wastewater was examined using complementary microbial ecology methods such us fluorescence in situ hybridization (fish), denaturing gradient gel electrophoresis (dgge), and cloning. the biofilm development can be roughly divided into three stages: an initial attachment phase (0-36 h) characterized by random adhesion of the cells to the surface; a co ... | 2008 | 18034358 |
| [changes in electrophysical characteristics of azospirillum brasilense sp7 cells during their interaction with polyclonal antibodies]. | electrooptical characteristics of azospirillum brasilense sp7 cells during their specific interaction with polyclonal rabbit antibodies were studied. dependence of optical density of cell suspension during electroorientation of cells from frequency of orienting field in interval 10, 100, 250, and 500 khz was evaluated. itwas shown that electrooptical (eo) characteristics of bacterial suspensions change during interaction of a. brasilense cells with antibodies, and maximal changes occur when freq ... | 2007 | 18038554 |
| identification and characterization of l-arabonate dehydratase, l-2-keto-3-deoxyarabonate dehydratase, and l-arabinolactonase involved in an alternative pathway of l-arabinose metabolism. novel evolutionary insight into sugar metabolism. | azospirillum brasiliense possesses an alternative pathway of l-arabinose metabolism, different from the known bacterial and fungal pathways. in the preceding articles, we identified and characterized l-arabinose-1-dehydrogenase and alpha-ketoglutaric semialdehyde dehydrogenase, which catalyzes the first and final reaction steps in this pathway, respectively (watanabe, s., kodaki, t., and makino, k. (2006) j. biol. chem. 281, 2612-2623 and watanabe, s., kodaki, t., and makino, k. (2006) j. biol. ... | 2006 | 16950779 |
| interactions between pii proteins and the nitrogenase regulatory enzymes drat and drag in azospirillum brasilense. | in azospirillum brasilense adp-ribosylation of dinitrogenase reductase (nifh) occurs in response to addition of ammonium to the extracellular medium and is mediated by dinitrogenase reductase adp-ribosyltransferase (drat) and reversed by dinitrogenase reductase glycohydrolase (drag). the p(ii) proteins glnb and glnz have been implicated in regulation of drat and drag by an as yet unknown mechanism. using pull-down experiments with his-tagged versions of drat and drag we have now shown that drat ... | 2006 | 16963029 |
| [isolation and characterization of nitrogen-fixing bacteria of the genus azospirillum from the soil of a sphagnum peat bog]. | the presence of nitrogen-fixing bacteria of the genus azospirillum in the soils of acidic raised sphagnum bogs is revealed for the first time. three azospirillum strains, b2, b21, and b22, were isolated as a component of methane-oxidizing enrichment cultures, whereas attempts to isolate them directly from peat samples have failed. the results of comparative analysis of the nucleotide sequences of 16s rrna genes, dna-dna hybridization, and the analysis of the sequences of the functional genes enc ... | 2007 | 17410881 |
| biofilm formation by plant-associated bacteria. | plants support a diverse array of bacteria, including parasites, mutualists, and commensals on and around their roots, in the vasculature, and on aerial tissues. these microbes have a profound influence on plant health and productivity. bacteria physically interact with surfaces to form complex multicellular and often multispecies assemblies, including biofilms and smaller aggregates. there is growing appreciation that the intensity, duration, and outcome of plant-microbe interactions are signif ... | 2007 | 17506679 |
| recent advances in nitrogen-fixing acetic acid bacteria. | nitrogen is an essential plant nutrient, widely applied as n-fertilizer to improve yield of agriculturally important crops. an interesting alternative to avoid or reduce the use of n-fertilizers could be the exploitation of plant growth-promoting bacteria (pgpb), capable of enhancing growth and yield of many plant species, several of agronomic and ecological significance. pgpb belong to diverse genera, including azospirillum, azotobacter, herbaspirillum, bacillus, burkholderia, pseudomonas, rhiz ... | 2008 | 18177965 |
| preliminary crystallographic analysis of l-2-keto-3-deoxyarabonate dehydratase, an enzyme involved in an alternative bacterial pathway of l-arabinose metabolism. | l-2-keto-3-deoxyarabonate (l-kda) dehydratase is a novel member of the dihydrodipicolinate synthase (dhdps)/n-acetylneuraminate lyase (nal) protein family and catalyzes the hydration of l-kda to alpha-ketoglutaric semialdehyde. l-kda dehydratase was overexpressed, purified and crystallized at 291 k using the hanging-drop vapour-diffusion method. the crystal diffracts to 2.0 a resolution using synchrotron radiation and belongs to the trigonal space group p3(1)21 or its enantiomorph p3(2)21, with ... | 2007 | 17565178 |