| distribution of the isopropylmalate pathway to leucine among diverse bacteria. | alpha-isopropylmalate synthase and beta-isopropylmalate dehydrogenase activities were detected in extracts of the following organisms: chromatium d, rhodopseudomonas spheroides, hydrogenomonas h16, pseudomonas aeruginosa, pseudomonas fluorescens, vibrio extorquens, rhizobium japonicum, alcaligenes viscolactis, escherichia coli b, proteus vulgaris, aerobacter aerogenes, salmonella typhimurium, micrococcus sp., micrococcus lysodeikticus, bacillus polymyxa, bacillus subtilis, and nocardia opaca. th ... | 1974 | 4829932 |
| [enzymes intervening in the formation of nucleotide-sugars in rhizobium japonicum]. | | 1967 | 4962178 |
| electron transport systems of rhizobium japonicum. i. haemoprotein p-450, other co-reactive pigments, cytochromes and oxidases in bacteroids from n2-fixing root nodules. | | 1969 | 4974059 |
| electron transport systems of rhizobium japonicum. ii. rhizobium haemoglobin, cytochromes and oxidases in free-living (cultured) cells. | | 1969 | 4974060 |
| serological analysis of eleven strains of rhizobium japonicum. | | 1969 | 4977516 |
| transformation of infectivity in rhizobium japonicum. | | 1970 | 4994104 |
| antigenic analysis of rhizobium japonicum by immunodiffusion. | immunodiffusion reactions were studied with seven strains of rhizobium japonicum and three strains of the cowpea miscellany by using antisera against eight of the strains. most strains yielded only weak precipitin bands when untreated cell suspensions were used as antigens in the diffusions. ultrasonic disruption or heat treatment of the cells led to stronger bands, and immersion in boiling water for 20 min was used as the standard procedure for preparing these bacteria for immunodiffusion analy ... | 1971 | 4998353 |
| interactions between an unusual aspartate aminotransferase from rhizobium japonicum and pyridoxal-5'-phosphate studied by affinity chromatography. | | 1972 | 5085272 |
| the biosynthesis of aspartic acid, glutamic acid, and alanine in rhizobium japonicum. | | 1971 | 5087891 |
| effect of azotobacter chroococcum and tryptophan on the inoculation of soybean (glycine max (l.) merril) with rhizobium japonicum. | | 1969 | 5271557 |
| transformation in rhizobium japonicum. | | 1969 | 5365772 |
| the regulation of some enzymes involved in ammonia assimilation by rhizobium japonicum. | | 1969 | 5370296 |
| competition between two somatic serotypes of rhizobium japonicum used as double-strain inocula in varying proportions. | | 1969 | 5394016 |
| effect of biotin on fatty acids and phospholipids of biotin-sensitive strains of rhizobium japonicum. | the effect of biotin on fatty acids and intact lipids was studied by comparing a biotin-requiring, a biotin-inhibited, and a biotin-indifferent strain of rhizobium japonicum. these organisms were grown in a defined medium with added levels of 0, 0.3, and 0.5 mug of biotin per liter, and were analyzed for fatty acids and lipid components. myristic, palmitic, and octadecenoic acids were found to be the major fatty acids in these strains. the indifferent strain also contained large amounts of c(19) ... | 1970 | 5437727 |
| gluconate catabolism in rhizobium japonicum. | gluconate catabolism in rhizobium japonicum atcc 10324 was investigated by the radiorespirometric method and by assaying for key enzymes of the major energy-yielding pathways. specifically labeled gluconate gave the following results for growing cells, with values expressed as per cent (14)co(2) evolution: c-1 = 93%, c-2 = 57%, c-3 = 30%, c-4 = 70%, c-6 = 39%. the preferential release of (14)co(2) from c-1 and c-4 indicate that gluconate is degraded primarily by the entner-doudoroff pathway but ... | 1970 | 5438044 |
| purification of aspartate aminotransferases from soya-bean root nodules and rhizobium japonicum. | | 1970 | 5500327 |
| [the role of rhizobium japonicum in the n-metabolism of soy beans under the varied soil conditions of bulgaria]. | | 1967 | 5632929 |
| alcohol precipitation as a method for collecting extracellular material from rhizobium japonicum. | | 1968 | 5636456 |
| thermostability of antigens associated with serotype of rhizobium japonicum. | the antigens associated with serologically distinct strains of rhizobium japonicum were found to differ in heat sensitivity. cell preparations from 4 out of 12 strains retained agglutinability, and 1 out of 5 retained antigenicity after they were heated to 120 c. antigenicity was reduced in most strains after heating to 100 c for 30 min, but agglutinability was not affected by this treatment. this suggests that the antigens are protein-polysaccharide-lipid complexes described for o-type antigens ... | 1968 | 5645406 |
| nitrogen, energy and vitamin nutrition of rhizobium japonicum. | | 1968 | 5702037 |
| glucose catabolism in rhizobium japonicum. | glucose catabolism in rhizobium japonicum atcc 10324 was investigated by the radiorespirometric method and by assaying for key enzymes of the major energy-yielding pathways. specifically labeled glucose gave the following results for resting cells, with values expressed as per cent (14)co(2) evolution: c-1=59%, c-2=51%, c-3=45%, c-4=59%, and c-6=43%. these values indicate that glucose was degraded by the entner-doudoroff pathway alone. cells which grew in glucose-yeast extract-salts medium gave ... | 1969 | 5776525 |
| deoxyribonucleic acid base composition of isolates of rhizobium japonicum. | | 1969 | 5786782 |
| nitrogen metabolism of some strains of rhizobium japonicum having different nodulating capacities. | | 1965 | 5879501 |
| some effects of medium composition and metabolic intermediates on biotin inhibition in a strain of rhizobium japonicum. | | 1967 | 6039199 |
| correlation of physiological characteristics with nodulating ability in rhizobium japonicum. | | 1967 | 6068177 |
| characterization of rhizobium japonicum hydrogen uptake genes. | recombinant cosmids from a gene library of the dna from hup+ rhizobium japonicum 122des previously have been shown to restore hydrogenase activity when transferred by conjugation into certain hup- mutants of r. japonicum. we generated a restriction map covering 32.2 kilobases of this cosmid dna. at least 25.3 kilobases of the cosmid phu1 were shown to have the same arrangement as those in the genome of strain 122des. analysis of tn5 insertions into the 122des genome indicates that hup-specific s ... | 1984 | 6090382 |
| isolation and expression of the bradyrhizobium japonicum adenylate cyclase gene (cya) in escherichia coli. | a 5.0-kilobase-pair hindiii fragment of bradyrhizobium japonicum dna containing the cya gene which encodes adenylate cyclase was isolated as an insert in pbr322, using marker rescue of the maltose-negative phenotype of an escherichia coli cya mutant for identification. the isolated b. japonicum dna fragment was capable of reversing the pleiotropic phenotype of cya mutations when inserted in either orientation in the hindiii site of pbr322. the complemented e. coli strains produced high levels of ... | 1984 | 6090388 |
| physical organization of the bradyrhizobium japonicum nitrogenase gene region. | in bradyrhizobium japonicum usda 110 the three genes that encode the nitrogenase enzyme complex are separated into two transcription units, nifh and nifdk. we have physically mapped a 33-kilobase-pair region of the b. japonicum genome that contains both nifh and nifdk. the nifdk operon is located transcriptionally upstream from nifh, and all three genes are transcribed in the same direction. within the 20-kilobase-pair region that separates the promoters for these two transcription units, we hav ... | 1984 | 6090394 |
| reiteration of genes involved in symbiotic nitrogen fixation by fast-growing rhizobium japonicum. | by using cloned rhizobium meliloti nodulation (nod) genes and nitrogen fixation (nif) genes, we found that the genes for both nodulation and nitrogen fixation were on a plasmid present in fast-growing rhizobium japonicum strains. two ecori restriction fragments from a plasmid of fast-growing r. japonicum hybridized with nif structural genes of r. meliloti, and three ecori restriction fragments hybridized with the nod clone of r. meliloti. cross-hybridization between the hybridizing fragments rev ... | 1984 | 6094491 |
| comparative properties of glutamine synthetases i and ii in rhizobium and agrobacterium spp. | some properties of glutamine synthetase i (gsi) and gsii are described for a fast-growing rhizobium sp. (rhizobium trifolii t1), a slow-growing rhizobium sp. (rhizobium japonicum usda 83), and agrobacterium tumefaciens c58. gsii of the fast-growing rhizobium sp. and gsii of the agrobacterium sp. were considerably more heat labile than gsii of the slow-growing rhizobium sp. as previously shown in r. japonicum 61a76, gsi became adenylylated rapidly in all species tested in response to ammonium. gs ... | 1980 | 6107288 |
| evaluation of active versus passive uptake of metabolites by rhizobium japonicum bacteroids. | rhizobium japonicum bacteroids were isolated anaerobically from soybean [glycine max (l.) merr] nodules. the bacteroids, which were capable of acetylene reduction and respiration, were used to study the uptake of metabolites by a method which permits correction for nonspecific adsorption of metabolites and estimation of total cell volume. these determinations permit active uptake to be assessed from metabolite accumulation against a concentration gradient. succinate, malate, alpha-ketoglutarate, ... | 1984 | 6203891 |
| purification and characterization of a ferredoxin from rhizobium japonicum bacteroids. | an eight-iron, eight-sulfur ferredoxin from rhizobium japonicum bacteroids of soybean root nodules has been purified to apparent homogeneity as judged by disc gel electrophoresis. the purification procedure included chromatography on deae-cellulose, bio-gel p-60, and hydroxylapatite. specific activities of several purified preparations of bacteroid ferredoxin ranged from 1700 to 1900 nmol of c2h4 produced . min-1 . mg-1 in the reaction mediating electron transfer between illuminated chloroplasts ... | 1980 | 6246115 |
| [adenosine-3':5'-monophosphate phosphodiesterase from rhizobium]. | the phosphodiesterase (pde) activity of adenosine-3':5'-monophosphate was detected in the cells of tubercular bacteria of rhizobium lupini and rhizobium japonicum. the specific activity of three rhizobium forms, e.g. bacteroids from lupine root tubercles, free-nitrogen-fixing culture and vegetative cells grown on a mannitol--yeast agar, were compared. in the bacteroids pde is represented both by soluble and membrane-bound forms. the optimal enzyme activity is revealed in an alkaline medium, wher ... | 1981 | 6263372 |
| carriers in electron transport from molecular hydrogen to oxygen in rhizobium japonicum bacteroids. | an investigation has been conducted to identify electron transport carriers that participate in the oxidation of h2 by h2 uptake-positive strains of rhizobium japonicum bacteroids. we have observed that the reduced form of dibromothymoquinone at a concentration of 0.2 mm strongly inhibited h2 uptake, endogenous respiration, and c2h2 reduction by bacteroid suspensions. reduced dibromothymoquinone, however, failed to inhibit the transfer of electrons from h2 to methylene blue under anaerobic condi ... | 1982 | 6277845 |
| effects of iron deficiency on heme biosynthesis in rhizobium japonicum. | the effects of iron deficiency on heme biosynthesis in rhizobium japonicum were examined. iron-deficient cells had a decreased maximum cell yield and a decreased cytochrome content and excreted protoporphyrin into the growth medium. the activities of the first two enzymes of heme biosynthesis, delta-aminolevulinic acid synthase (ec 2.3.1.37) and delta-aminolevulinic acid dehydrase (ec 4.2.1.24), were diminished in iron-deficient cells, but were returned to normal levels upon addition of iron to ... | 1982 | 6277847 |
| rhizobium japonicum mutants that are hypersensitive to repression of h2 uptake by oxygen. | the synthesis of an h2 oxidation system in free-living rhizobium japonicum wild-type strain sr is repressed by oxygen. maximal h2 uptake rates were obtained in strain sr after derepression in 11 microm or less dissolved oxygen. oxygen levels above 45 microm completely repressed h2 uptake in strain sr. five r. japonicum mutant strains that are hypersensitive to repression or h2 oxidation by oxygen were derived from strain sr. the mutants were obtained by screening h2 uptake-negative mutants that ... | 1982 | 6277861 |
| interspecific plasmid and genomic dna sequence homologies and localization of nif genes in effective and ineffective strains of rhizobium japonicum. | three strains of rhizobium japonicum were examined for the presence of interspecific conserved plasmid-borne dna sequences and the location of their nif dna sequences. strains 61a76 and 110, which both form effective (nitrogen fixing) nodules on soybeans show very low (24%) total dna sequence homology with each other; strain 61a76 contains one plasmid, and strain 110 contains no identifiable plasmids. strain 61a24 which forms ineffective nodules on soybeans shows relatively high (50%) sequence h ... | 1981 | 6286824 |
| electron transport components involved in hydrogen oxidation in free-living rhizobium japonicum. | membranes from free-living rhizobium japonicum were isolated to study electron transport components involved in h2 oxidation. the h2/o2 uptake rate ratio in membranes was approximately 2. the electron transport inhibitors antimycin a, cyanide, azide, hydroxylamine, and 2-n-heptyl-4-hydroxyquinoline-n-oxide (hqno) inhibited h2 uptake and h2-dependent o2 uptake significantly. h2-reduced minus o2-oxidized absorption difference spectra revealed peaks at 551.5, 560, and 603 nm, indicating the involve ... | 1982 | 6288665 |
| in rhizobium japonicum the nitrogenase genes nifh and nifdk are separated. | in contrast to klebsiella pneumoniae or fast-growing rhizobium species, such as r. meliloti, where the nitrogenase structural genes are clustered in one operon (nifhdk), in slow-growing rhizobium japonicum 110, nifh and nifdk are on separate operons. | 1983 | 6307985 |
| regulation of hydrogenase in rhizobium japonicum: analysis of mutants altered in regulation by carbon substrates and oxygen. | the synthesis of the h2 uptake system in free-living rhizobium japonicum sr is repressed both by oxygen and by carbon substrates. mutants selected for the ability to express hydrogenase in 10.0% partial pressure o2 were also less sensitive than the wild type to repression by carbon substrates such as arabinose, glycerol, gluconate, and succinate. the h2 uptake system in another class of mutants, previously shown to be hypersensitive to repression by o2, is also more sensitive to repression by ca ... | 1983 | 6315681 |
| rhizobium japonicum nitrogenase fe protein gene (nifh). | a 12.1-kilobase psti fragment from rhizobium japonicum, which contains homology to both the klebsiella pneumoniae and the rhizobium meliloti nifh genes, was cloned into vector phe3 . the nifh -homologous region was localized on the restriction enzyme cleavage map by southern blot hybridization experiments. dna fragments overlapping the r. japonicum nifh gene were subcloned into plasmid vectors to allow the expression of this region in escherichia coli minicells. the nifh gene product (the polype ... | 1984 | 6327620 |
| isolation and expression of rhizobium japonicum cloned dna encoding an early soybean nodulation function. | a first visible step in the nodulation of legumes by rhizobium spp. is the deformation and curling of root hairs. we have identified and cloned dna sequences encoding this function from two strains of rhizobium japonicum (usda 122 and usda 110) with a weakly homologous probe from rhizobium meliloti. root hair curling encoded by the cloned dna fragments was examined on soybeans (glycine soja ) after conjugative transfer of these sequences in broad-host-range vectors to various bacterial genera. p ... | 1984 | 6327649 |
| transposon tn5-induced mutagenesis of rhizobium japonicum yielding a wide variety of mutants. | when the "suicide" vector psup1011, which carries transposon tn5 (kmr), was introduced into rhizobium japonicum usda 110, kanamycin-resistant (kmr) colonies were detected at a frequency (4.2 x 10-6) ca. 30 times greater than the spontaneous kanamycin resistance frequency (1.4 x 10-7). ten thousand kmr mutants were isolated and tested for nutritional auxotrophy. auxotrophs were detected at a frequency of 0.5%. the following classes of auxotrophs were identified: adenine- (three), histidine- (thre ... | 1984 | 6330038 |
| induced plasmid-genome rearrangements in rhizobium japonicum. | the p group resistance plasmids rp1 and rp4 were introduced into rhizobium japonicum by polyethylene-glycol-induced transformation of spheroplasts. after cell wall regeneration, transformants were recovered by selecting for plasmid determinants. plant nodulation, nitrogen fixation, serological, and bacterial genetics studies revealed that the transformants were derived from the parental strains and possessed the introduced plasmid genetic markers. agarose gel electrophoresis, restriction enzyme ... | 1984 | 6360996 |
| preservation of rhizobium viability and symbiotic infectivity by suspension in water. | three rhizobium japonicum strains and two slow-growing cowpea-type rhizobium strains were found to remain viable and able to rapidly modulate their respective hosts after being stored in purified water at ambient temperatures for periods of 1 year and longer. three fast-growing rhizobium species did not remain viable under the same water storage conditions. after dilution of slow-growing rhizobium strains with water to 10(3) to 10(5) cells ml-1, the bacteria multiplied until the viable cell coun ... | 1984 | 6378090 |
| some properties of the nickel-containing hydrogenase of chemolithotrophically grown rhizobium japonicum. | the uptake hydrogenase of chemolithotrophically grown rhizobium japonicum was purified to apparent homogeneity with a final specific activity of 69 mumol of h2 oxidized per min per mg of protein. the procedure included triton extraction of broken membranes and deae-cellulose and sephacryl s-200 chromatographies. the purified protein contained two polypeptides separable only by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. they comigrated on native polyacrylamide gels and sucrose den ... | 1984 | 6384183 |
| coordinate expression of hydrogenase and ribulose bisphosphate carboxylase in rhizobium japonicum hupc mutants. | in contrast to the wild type, h2 uptake-constitutive mutants of rhizobium japonicum expressed both hydrogenase and ribulose bisphosphate carboxylase activities when grown heterotrophically. however, as bacteroids from soybean root nodules, the h2 uptake-constitutive mutants, like the wild type, did not express ribulose bisphosphate carboxylase activity. | 1984 | 6384199 |
| succinate transport by free-living forms of rhizobium japonicum. | we have demonstrated that the transport of succinate into the cells of rhizobium japonicum strains usda 110 and usda 217 is severely inhibited by cyanide, azide, and 2,4-dinitrophenol, but not by arsenate. these results suggest an active mechanism of transport that is dependent on an energized membrane, but does not directly utilize atp. the apparent km for succinate was 3.8 microm for strain usda 110 and 1.8 microm for strain usda 217; maximal transport velocities were 1.5 and 3.3 nmol of succi ... | 1983 | 6402487 |
| transfer of nitrate reductase genes of the cyanobacterium nostoc muscorum into rhizobium japonicum. | transformation of rhizobium japonicum cb1809 was studied using dna from the cyanobacterium nostoc muscorum atcc 27893. a spontaneous nitrate reductase deficient (nar-) mutant (nr-6) of r. japonicum cb1809 was isolated with a frequency of 8.4 x 10(-7). streptomycin (sm) and neomycin (neo) resistance markers were introduced into strain nr-6, and the resulting strain was designated nr-6 smr neor. experiments with cyanobacterial dna and live cells of strain nr-6 smr neor indicated transformation of ... | 1983 | 6415231 |
| comparative study of the dna-binding hu-type proteins from slow growing and fast growing strains of rhizobiaceae. | the dna-binding hu-type proteins have been isolated from two very different strains of rhizobiaceae : agrobacterium tumefaciens and rhizobium japonicum. these proteins have been called hat and hrj respectively. their electrophoretic mobility on polyacrylamide gel, amino acid composition and crossed immunoreactivity have been compared to that of the homologous protein isolated from rhizobium meliloti: the protein hrm . the proteins hat and hrm show close similarities whereas the protein hrj diffe ... | 1984 | 6428409 |
| nickel is a component of hydrogenase in rhizobium japonicum. | the derepression of h2-oxidizing activity in free-living rhizobium japonicum does not require the addition of exogenous metal to the derepression media. however, the addition of edta (6 microm) inhibited derepression of h2 uptake activity by 80%. the addition of 5 microm nickel to the derepression medium overcame the edta inhibition. the addition of 5 microm cu or zn also relieved edta inhibition, but to a much lesser extent; 5 microm fe, co, mg, or mn did not. the kinetics of induction and magn ... | 1984 | 6429119 |
| bacteriophage that can distinguish between wild-type rhizobium japonicum and a non-nodulating mutant. | a bacteriophage (phage tn1) that lyses rhizobium japonicum 3i1b110 was isolated from tennessee soil. structurally, this phage resembles the escherichia coli phage t4, having an icosahedral head (47 by 60 nm) and a contractile tail (17 by 80 nm). an interesting feature of this phage is that it lyses all of the symbiotic defective mutants derived from r. japonicum 3i1b110 that were tested, except one, mutant strain hs123. mutant strain hs123 is a non-nodulating mutant that is defective in attachme ... | 1984 | 6476831 |
| role of rhizobitoxine in protecting soybean roots from macrophomina phaseolina infection. | bacterization of soybean seeds or roots with rhizobium japonicum significantly reduced charcoal rot disease caused by macrophomina phaseolina . rhizobium japonicum inhibited the growth of m. phaseolina on both liquid and solid media. replacement of nutrient medium with culture filtrate of r. japonicum significantly reduced mycelial growth of m. phaseolina . whole culture extracts of r. japonicum yielded a toxic substance which was identified as rhizobitoxine after chromatographic, ultraviolet, a ... | 1984 | 6539157 |
| mode of infection, nodulation specificity, and indigenous plasmids of 11 fast-growing rhizobium japonicum strains. | eleven fast-growing strains of rhizobium japonicum were characterized with respect to indigenous plasmids and abilities to infect (inf+) and nodulate (nod+) cowpea, siratro, wild soybean, and three commercial cultivars of soybean. all strains caused infection via infection threads in root hairs and consistently nodulated cowpea, siratro, and wild soybean in growth pouches. interactions with commercial cultivars of soybean were strikingly strain specific. some combinations were nod-, and infectio ... | 1984 | 6542099 |
| extracellular polysaccharide composition, ex planta nitrogenase activity, and dna homology in rhizobium japonicum. | the composition of the major acidic extracellular polysaccharide (eps) of 25 strains of rhizobium japonicum was determined. eight strains synthesized an acidic eps containing rhamnose and 4-o- methylglucuronic acid and were closely related according to dna homology. these same strains also expressed high levels of ex planta nitrogenase activity. sixteen strains produced an acidic eps containing glucose, mannose, galacturonic acid, and galactose and were also related by dna homology. these strain ... | 1984 | 6586714 |
| the nifh and nifdk promoter regions from rhizobium japonicum share structural homologies with each other and with nitrogen-regulated promoters from other organisms. | in several species of rhizobium the three genes which encode the nitrogenase complex are separated into two operons, nifh and nifdk. we have mapped the transcriptional promoter sites for these two operons from r. japonicum usda strain 110 by s1 protection analyses using bacterial rna isolated from soybean nodules. transcription of the nifdk operon is initiated at a site located 46 nucleotides upstream of the proposed translation initiation codon. nifh transcription initiates predominantly at a s ... | 1984 | 6588133 |
| high-frequency induction of nodulation and nitrogen fixation mutants of rhizobium japonicum. | more than 50 symbiotic mutants of rhizobium japonicum were isolated by purported plasmid-curing techniques. wild-type r. japonicum strains were grown in liquid culture at 28 or 36 degrees c in different concentrations of acridine orange, ethidium bromide, or sodium dodecyl sulfate for selection of mutants. the symbiotic traits of 133 isolates from nine treatment groups were determined. forty-two isolates were nod- nif+, seven were nod+ nif-, and two were nod- nif-. the nifdh genes were deleted i ... | 1983 | 6630155 |
| rna polymerase from rhizobium japonicum. | dna-dependent rna polymerase (ec 2.7.7.6) from rhizobium japonicum was purified. the subunit structure was found to be beta beta' alpha 2 alpha, with the following apparent molecular weights determined by electrophoresis: mr (beta and beta') 150,000 each, mr (sigma) 96,000, mr (alpha) 40,000, mr (holoenzyme) 490,000, mr (core enzyme) 380,000. the recovery of sigma was 28%. rna polymerase from aerobically grown r. japonicum cells and from nitrogen-fixing cells have the same electrophoretic proper ... | 1983 | 6639271 |
| compatibility of rhizobium japonicum with commercial pesticides in vitro. | | 1983 | 6640140 |
| tryptophan auxotrophs of rhizobium japonicum. | eleven tryptophan-requiring mutants of rhizobium japonicum i-110 ars were isolated after nitrous acid mutagenesis and fell into five groups based on characterization by supplementation with intermediates and enzyme assays. | 1983 | 6643394 |
| effects of culture age on symbiotic infectivity of rhizobium japonicum. | the infectivity of the soybean symbiont rhizobium japonicum changed two- to fivefold with culture age for strains 110 ars, 138 str spc, and 123 spc, whereas culture age had relatively little effect on the infectivity of strains 83 str and 61a76 str. infectivity was measured by determining the number of nodules which developed on soybean primary roots in the zone which contained developing and preemergent root hairs at the time of inoculation. root cells in this region of the host root are suscep ... | 1983 | 6681538 |
| chemoautotrophic growth of hydrogen-uptake-positive strains of rhizobium japonicum. | recently reported research from this laboratory has demonstrated the autotrophic growth of certain hydrogen-uptake-positive strains of rhizobium japonicum and defined minimal conditions for such growth. ribulose 1,5-bisphosphate carboxylase has been detected in autotrophically growing cells, but at low specific activity. moreover, growth rates were low, and growth ceased at low cell densities. we report here improved autotrophic growth rates of r. japonicum sr through the use of a modified miner ... | 1980 | 6767687 |
| [genetic analysis of rhizobium japonicum]. | | 1981 | 6780290 |
| rhizobium japonicum mutant strains unable to grow chemoautotrophically with h2. | rhizobium japonicum strain sr grows chemoautotrophically on a mineral salts medium when incubated in an h2- and co2-containing atmosphere. mutant strains unable to grow or that grow very poorly chemoautotrophically with h2 have been isolated from strain sr. the mutant isolation procedure involved mutagenesis with ethyl methane sulfonate, penicillin selection under chemoautotrophic growth conditions, and plating of the survivors onto medium containing carbon. the resulting colonies were replica p ... | 1981 | 6780521 |
| revertible hydrogen uptake-deficient mutants of rhizobium japonicum. | we have developed mutants of rhizobium japonicum which are deficient in h2 uptake capacity (hup-) and which spontaneously revert to the parent type at a frequency consistent with that of a single-point mutation (ca. 1.0 x 10(-09)). the mutagenesis by nitrous acid and the selection of the hup- phenotype by using penicillin and chemolithotrophy as enrichment for chemolithotrophy-deficient strains are described. two mutants retain low but reproducible levels of ribulose bisphosphate-dependent co2 f ... | 1981 | 6783623 |
| requirement for carbon dioxide for nonsymbiotic expression of rhizobium japonicum nitrogenase activity. | the expression and maintenance of nitrogenase (c(2)h(2)) activity in growing, microaerobic liquid cultures of rhizobium japonicum 3i1b110 was found to be stringently dependent on the sustained supply of co(2). this requirement for co(2) appeared to exceed the basal requirement for growth and was not related to effects on ph. | 1982 | 6811563 |
| enhancement of specific nitrogenase activity in azospirillum brasilense and klebsiella pneumoniae, inhibition in rhizobium japonicum under air by phenol. | specific nitrogenase activity in azospirillum brasilense atcc 29145 in surface cultures under air is enhanced from about 50 nmol c2h4 x mg protein -1 x h-1 to 400 nmol c2h4 by the addition of 1 mm phenol. 0.5 and 2 mm phenol added increase the rate 5-fold and 4-fold. this enhancement effect is observed only between 2 and 3 days after inoculation, with only a small reduction of the growth of the cells by the phenol added. in surface cultures under 1% o2, nitrogenase activity is slightly reduced b ... | 1982 | 6812526 |
| pleomorphism and acetylene-reducing activity of free-living rhizobia. | cowpea-type rhizobium sp. strain 32h1 and rhizobium japonicum usda 26 and 110 grown on a glutamate-mannitol-gluconate agar medium showed increases in the number of pleomorphic cells coincident with their acetylene-reducing activity. pleomorphs appeared to be inhibited in growth nonuniformly, because acetylene-reducing cultures were mixtures of rod, branched (v, y, and t), and other irregularly shaped cells. in contrast, strain usda 10 consistently failed to reduce acetylene, even though it also ... | 1983 | 6822472 |
| a soybean lectin having 4-o-methyl-d-glucuronic acid specificity. | evidence is presented for the presence of a new lectin activity in soybean seeds [glycine max (l.) merrill] that has specificity towards the 4-o-methyl-d-glucurono-l-rhamnan exopolysaccharide produced by certain strains of rhizobium japonicum. bacterial agglutination and precipitin reactions revealed the lectin activity in phosphate-buffered saline extracts of seeds of all cultivars tested, including the "lectinless" varieties. reaction of such extracts with carbohydrate haptens demonstrated tha ... | 1983 | 6838587 |
| protoporphyrin formation in rhizobium japonicum. | the obligately aerobic soybean root nodule bacterium rhizobium japonicum produces large amounts of heme (iron protoporphyrin) only under low oxygen tensions, such as exist in the symbiotic root nodule. aerobically incubated suspensions of both laboratory-cultured and symbiotic bacteria (bacteroids) metabolize delta-aminolevulinic acid to uroporphyrin, coproporphyrin, and protoporphyrin. under anaerobic conditions, suspensions of laboratory-cultured bacteria form greatly reduced amounts of protop ... | 1983 | 6841317 |
| involvement of cytochromes and a flavoprotein in hydrogen oxidation in rhizobium japonicum bacteroids. | electron transport components involved in h2 oxidation were studied in membranes from rhizobium japonicum bacteroids. hydrogen oxidation in membranes was inhibited by antimycin a and 2-n-heptyl-4-hydroxyquinoline-n-oxide with ki values of 39.4 and 5.6 microm, respectively. the inhibition of h2 uptake by cyanide was triphasic with ki values of 0.8, 9.9, and 93.6 microm. this result suggested that three cyanide-reactive components were involved in h2 oxidation. h2-reduced minus o2-oxidized absorpt ... | 1983 | 6874637 |
| nif- hup- mutants of rhizobium japonicum. | two h2 uptake-negative (hup-) rhizobium japonicum mutants were obtained that also lacked symbiotic n2 fixation (acetylene reduction) activity. one of the mutants formed green nodules and was deficient in heme. hydrogen oxidation activity in this mutant could be restored by the addition of heme plus atp to crude extracts. bacteroid extracts from the other mutant strain lacked hydrogenase activity and activity for both of the nitrogenase component proteins. hup+ revertants of the mutant strains re ... | 1983 | 6874648 |
| [induced resistance to kanamycin and tetracycline in rhizobium japonicum]. | spontaneous mutants km-r and tc-r of r. japonicum with various levels of resistance to kanamycin (0.8-20 mg/ml) and tetracycline (130-210 micrograms/ml) were isolated. no cross resistance in the mutants was observed. plasmid r68.45 transferred to the wild strains resistance to 210 micrograms/ml of tetracycline and to 20 mg/ml of kanamycin. this plasmid did not practically increase the resistance to tetracycline in mutants tc-r. at the same time it markedly increased the resistance to kanamycin i ... | 1983 | 6881945 |
| screening for mutants of rhizobium japonicum with defects in nitrogen fixing ability. | mutants of rhizobium japonicum with reduced ex planta nitrogenase activity could be isolated with high frequency by direct screening of ultra-violet mutagenized bacteria growing as spots on the surface of an appropriate agar medium permitting derepression of nitrogenase synthesis. small glass chambers fitted with a serum cap were pushed into the agar around each spot of growth, forming a small enclosed gas space which was made to 10% acetylene, permitting assessment of nitrogenase activity by th ... | 1980 | 6934662 |
| root exudates in relation to growth and nitrogenase activity of rhizobium japonicum. | root exudates of cowpea and soybean were collected in aerated water cultures. the ability of these exudates to support nitrogenase activity of r. japonicum was studied on defined media. when a complete nitrogenase-inducing medium was supplemented with concentrated root exudate, there was an increased nitrogenase activity. when the cowpea root exudate was substituted for glutamine or sodium succinate in the medium, nitrogenase activity was not detected. growth was good when the root exudate was s ... | 1981 | 6949404 |
| rhizobium japonicum mutants defective in symbiotic nitrogen fixation. | rhizobium japonicum strains 3i1b110 and 61a76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. the proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. all of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wil ... | 1982 | 6956566 |
| plasmid transfer within and between serologically distinct strains of rhizobium japonicum, using antibiotic resistance mutants and auxotrophs. | methionine-requiring and pantothenic acid-requiring auxotrophs of rhizobium japanicum usda 31, as well as highly antibiotic-resistant mutants of r. japonicum strains usda 31, usda 110, usda 138, and webster 48, were isolated. these mutants were used to transfer the p-1 group plasmids r68.45 and rp4 within and between strains usda 31, usda 110, and webster 48. attempts to demonstrate transfer of either plasmid to strain usda 138 were unsuccessful. | 1981 | 7007335 |
| uptake hydrogenase activity and atp formation in rhizobium leguminosarum bacteroids. | the role of uptake hydrogenase was studied in rhizobium leguminosarum bacteroids from the nodules of pisum sativum l. cv. homesteader. uptake hydrogenase activity, measured by the 3h2 uptake method, was dependent on o-consumption and was similar to h2 uptake measured by gas chromatography. km for o2 of 0.0007 atm (0.0709 kpa) and a km for h2 of 0.0074 atm (0.7498, kpa) were determined. h2 increased the rate of endogenous respiration by isolates with uptake hydrogenase (hup+) but had no effect on ... | 1982 | 7047503 |
| reconstitution of h2 oxidation activity from h2 uptake-negative mutants of rhizobium japonicum bacteroids. | an in vitro reconstitution of both methylene blue and oxygen-dependent h2 uptake activity from extracts of hup- (h2 uptake-negative) mutant strains of rhizobium japonicum bacteroids is described. cell-free extracts prepared from bacteroids formed from two different hup- mutants were mixed, and active h2 oxidizing particles formed. extracts from each mutant alone did not oxidize h2. the source of the components required for the complementation were soluble. mixing of membrane particles from the t ... | 1982 | 7056758 |
| nitrogen fixation (nif) genes and large plasmids of rhizobium japonicum. | the location of structural nitrogen-fixation genes was determined for the slow- and fast-growing types of rhizobium japonicum. slow-growing r. japonicum strains do not harbor structural nif genes, homologous to nifd and nifh, on large plasmids (100 to 200 megadaltons). in contrast, all fast-growing r. japonicum strains, except prc194, contain structural nif genes on large plasmids. | 1982 | 7130134 |
| lectins and the soybean-rhizobium symbiosis. i. immunological investigations of soybean lines, the seeds of which have been reported to lack the 120 000 dalton soybean lectin. | seeds of six soybean lines (glycine max (l.) merr. cv. columbia, d68-127, norredo, sooty, t-102, wilson 5) have been reported to lack the 120 000 dalton soybean lectin. immunodiffusion and radioimmunoassay using anti-soybean lectin immunoglobulin failed to detect the lectin in seeds of five lines, but d68-127 seeds contained as much soybean lectin as the control line, harosoy 63. the d68-127 seed lectin could be purified by affinity chromatography on sepharose-n-caproylgalactosamine, and was ind ... | 1980 | 7190028 |
| differentiation of rhizobium japonicum strain derivatives by antibiotic sensitivity patterns, lectin binding, and utilization of biochemicals. | several strains of rhizobium japonicum have been reported to consist of mixtures of stable derivativess having distinct colony morphologies and physiological characteristics. we isolated derivatives from strains of r. japonicum and systematically compared them with previously isolated derivatives with respect to the utilization of biochemicals, antibiotic sensitivity, and soyben lectin binding. with the exception of a pair of derivatives from 3ilb110, one of which utilized pyruvate and one of wh ... | 1980 | 7190460 |
| nodulation of soybeans carrying the nodulation-restrictive gene, rj1, by an incompatible rhizobium japonicum strain upon mixed inoculation with a compatible strain. | the rj1 gene in soybeans prevents nodulation by most strains of rhizobium japonicum. several strains, however, are known to nodulate rj1 plants in vermiculite or sand culture. pure broth cultures of one of these strains (61 nalr) and a strain producing the typical non-nodulating response with rj1 (i-110 ars) were mixed and used as inoculum on clark rj1 soybeans in a growth chamber experiment. both strains carried drug resistance markers and were identified using selective media. analysis of the ... | 1980 | 7190864 |
| free-living and symbiotic characteristics of chlorate resistant mutants of rhizobium. | this work investigated the usefulness of chlorate resistance as a method for the selection of nitrate reductase negative (nr-) strains from rhizobium japonicum (61a76) and evaluated the symbiotic, characteristics of these strains. chlorate resistent strains were selected from populations seeded on cs 7 agar containing 10 or 20 mm kc10, and incubated in 2% air- 98% n2-co2 (95:5). over 200 resistant strains were isolated, 58% of which lacked the dissimilatory nitrate reductase. in 12 selected isol ... | 1980 | 7190866 |
| localization and partial characterization of soybean lectin-binding polysaccharide of rhizobium japonicum. | immunoelectron microscopy was combined with partial characterization of isolated exopolysaccharide to study binding of soybean lectin by rhizobium japonicum strain usda 138. lectin-binding activity resided in two forms of exopolysaccharide produced during growth: an apparently very high-molecular-weight capsular form and a lower-molecular-weight diffusible form. at low-speed centrifugation, the capsular form cosedimented with cells to form a viscous, white, cell-gel complex which was not diffusi ... | 1981 | 7193204 |
| nitrogen fixation by nitrate reductase deficient mutants of rhizobium japonicum. | | 1980 | 7194311 |
| regulation of the expression of leghaemoglobin genes in effective and ineffective root nodules of soybean. | the expression of leghaemoglobin genes in effective and ineffective (unable to fix nitrogen) root nodules of soybean developed by rhizobium japonicum strains 61a76, 61a24 and sm5 was measured by using a cdna probe or a cloned leghaemoglobin sequence and in vitro translation of lb-mrna. hybridization of the poly(a)-containing nodule polysomal rna from 3-week-old nodules with a kinetically purified lb-cdna or with plasmid (plbl) containing a leghaemoglobin sequence showed that lb-mrna is present i ... | 1981 | 7194688 |
| interaction of lectins from soybean and peanut with rhizobia that nodulate soybean, peanut, or both plants. | four of 14 strains of rhizobium japonicum from soybean nodulated peanut (arachis hypogaea l. cultivar jumbo virginia), and 3 of 8 rhizobium sp. strains from peanut nodulate soybean (glycine max (l.) merr. cultivar harosoy 63). cells of three peanut rhizobia bound fluorescent- and radioisotope-labeled soybean lectin. two of these strains failed to nodulate soybean, and conversely, two peanut strains that nodulated soybean did not bind to soybean lectin. both culture medium and age had pronounced ... | 1980 | 7195297 |
| application of two new methods for cleavage of polysaccharides into specific oligosaccharide fragments. structure of the capsular and extracellular polysaccharides of rhizobium japonicum that bind soybean lectin. | the extracellular polysaccharide produced by the bacterium rhizobium japonicum has been implicated in the recognition between symbionts which takes place in the association of r. japonicum with soybean. the complete primary structure of the polysaccharide produced by r. japonicum strain 3i1b 138 has been determined by a combination of conventional and unconventional methods. the polymer contains glucose, mannose, and galacturonic acid in the molar ratio of 2:1:1 and contains a varying proportion ... | 1982 | 7199046 |
| soluble aldehyde dehydrogenase and metabolism of aldehydes by soybean bacteroids. | a soluble aldehyde dehydrogenase (ec 1.2.1.3) was partially purified from rhizobium japonicum bacteroids and from free-living r. japonicum 61a76. the enzyme was activated by nad+, nadh, and dithiothreitol, and it reduced nad(p)+. acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, and succinic semialdehyde were substrates. the km for straight-chain aldehydes decreased with increasing carbon chain length. the aldehyde dehydrogenase was inhibited by 6-cyanopurine, but not by metronidazole. ... | 1982 | 7202001 |
| identification of "nodule-specific" host proteins (nodoulins) involved in the development of rhizobium-legume symbiosis. | infection of legume roots with rhizobium species results in the development of a root nodule structure in which the bacteria form an intracellular symbiosis with the plant. we report here that the infection of soybean (glycine max l.) roots with rhizobium japonicum results in the synthesis by the plant of at least 18-20 polypeptides other than leghemoglobin during the development of root nodules. identification of these "nodule-specific" host polypeptides (referred to as nodulins) was accomplish ... | 1980 | 7388942 |
| fractionation and characterization of two morphologically distinct types of cells in rhizobium japonicum broth culture. | differential centrifugation of stationary phase broth culture of rhizobium japonicum yielded two distinct morphological types of bacterial cells, rods, and small coccoid forms with capsulated and non-capsulated cells in each group. the rods usually had polar capsules which resulted in "star" formation. the coccoid bacteria were either free with thick capsular material surrounding the cells or held together in a common capsular sheath forming clusters and chains. 125i soybean. lectin bound to the ... | 1980 | 7407699 |
| effect of fungicides on growth of rhizobium japonicum in vitro. | | 1980 | 7426785 |
| photosynthetic symbionts of aeschynomene spp. form a cluster with bradyrhizobia on the basis of fatty acid and rrna analyses. | the relationship between photosynthetic rhizobia that nodulate 10 aeschynomene species (aeschynomene afraspera, aeschynomene denticulata, aeschynomene evenia, aeschynomene indica, aeschynomene nilotica, aeschynomene pratensis, aeschynomene rudis, aeschynomene scabra, aeschynomene schimperi, and aeschynomene sensitiva) and reference strains of the genera bradyrhizobium, rhizobium, and azorhizobium was investigated by analyzing cellular fatty acid methyl esters (fame) and 16s rrna sequences. the m ... | 1994 | 7520731 |
| phenotypic and genotypic characterization of bradyrhizobia nodulating the leguminous tree acacia albida. | rhizobial isolates that were obtained from both surface and deep soil samples in the sahelian and sudano-guinean areas of senegal (west africa) under acacia albida trees were compared with representative strains of known rhizobial species and genera. sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) of proteins was used to determine the taxonomic positions of these organisms and the relationships between isolates obtained from the surface and isolates obtained from deep soil. ... | 1994 | 7520737 |
| bradyrhizobium liaoningense sp. nov., isolated from the root nodules of soybeans. | seventeen strains of extra-slowly growing (esg) soybean rhizobia isolated from root nodules of glycine soja and glycine max growing in five provinces (liaoning, heilongjiang, shanxi, hubei, and anhui) in the people's republic of china were compared with 48 reference strains belonging to the genera bradyrhizobium, rhizobium, and agrobacterium by performing a numerical analysis of 191 phenotypic features. our results showed that all of the esg strains examined clustered closely in the genus bradyr ... | 1995 | 7547289 |
| characterization of the cmch genes of nocardia lactamdurans and streptomyces clavuligerus encoding a functional 3'-hydroxymethylcephem o-carbamoyltransferase for cephamycin biosynthesis. | sequencing of orf10 (gene cmch) of the nocardia lactamdurans cephamycin gene cluster proved that it encodes a protein with a deduced molecular mass of 57,149 da. this protein showed significant similarity to the putative o-carbamoyltransferases (o-cases) encoded by the nodu genes of rhizobium fredii and bradyrhizobium japonicum, involved in the synthesis of nodulation factors. the carbamoyl-phosphate (cp)-binding amino-acid sequence of human otcase is conserved in the cmch product. a similar cmc ... | 1995 | 7557411 |
| identification of rhizobium-specific intergenic mosaic elements within an essential two-component regulatory system of rhizobium species. | analysis of the dna regions upstream of the phosphoenolpyruvate carboxykinase gene (pcka) in rhizobium meliloti and rhizobium sp. strain ngr234 identified an open reading frame which was highly homologous to the agrobacterium tumefaciens chromosomal virulence gene product chvi. a second gene product, 500 bp downstream of the chvi-like gene in r. meliloti, was homologous to the a. tumefaciens chvg protein. the homology between the r. meliloti and a. tumefaciens genes was confirmed, because the r. ... | 1995 | 7559334 |
| ihf- and rpon-dependent regulation of hydrogenase expression in bradyrhizobium japonicum. | sequence analysis of the bradyrhizobium japonicum hydrogenase promoter regulatory region indicated the presence of a -24/-12 type promoter, which is recognized by rpon, and a potential integration host factor (ihf)-binding site. b. japonicum rpon1-/rpon2- double mutants were deficient in hydrogen-uptake activity. using plasmid-borne hup-lacz fusions, it was shown that the rpon mutants were also deficient in nickel-dependent transcriptional regulation of hydrogenase. gel-shift assays of the hydro ... | 1995 | 7565102 |
| cloning of nod gene regions from mesquite rhizobia and bradyrhizobia and nucleotide sequence of the nodd gene from mesquite rhizobia. | nitrogen-fixing symbiosis between bacteria and the tree legume mesquite (prosopis glandulosa) is important for the maintenance of many desert ecosystems. genes essential for nodulation and for extending the host range to mesquite were isolated from cosmid libraries of rhizobium (mesquite) sp. strain hw17b and bradyrhizobium (mesquite) sp. strain hw10h and were shown to be closely linked. all of the cosmid clones of rhizobia that extended the host range of rhizobium (parasponia) sp. strain ngr234 ... | 1995 | 7574650 |