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fructose 1,6-bisphosphate aldolase activity of rhizobium species.fdp aldolase was found to be present in the cell-free extracts of rhizobium leguminosarum, rhizobium phaseoli, rhizobium trifolii, rhizobium meliloti, rhizobium lupini, rhizobium japonicum and rhizobium species from arachis hypogaea and sesbania cannabina. the enzyme in 3 representative species has optimal activity at ph 8.4 in 0.2m veronal buffer. the enzyme activity was completely lost by treatment at 60 degrees c for 15 min. the km values were in the range from 2.38 to 4.55 x 10(-6)m fdp. met ...1975283
the purification and properties of the glutamine synthetase from the cytosol of soya-bean root nodules.the major portion of glutamine synthetase activity in root nodules of soya-bean plants is associated with the cytosol rather than with rhizobium japonicum bacteroids. glutamine synthetase accounts for about 2% of the total soluble protein in nodule cytosol. glutamine synthetase from nodule cytosol has been purified by a procedure involving fractionation with protamine sulphate, ammonium sulphate and polypropylene glycol, chromatography on deae-bio-gel a and bio-gel a-5m and affinity chromatograp ...19768035
regulation of nitrogen fixation by rhizobia. export of fixed n2 as nh+4.the metabolic fate of gaseous nitrogen (15n2) fixed by free-living cultures of rhizobia (root nodule bacteria) induced for their n2-fixation system was followed. a majority of the fixed 15n2 was found to be exported into the cell supernatant. for example, as much as 94% of the 15n2 fixed by rhizobium japonicum (soybean symbiont) was recovered as 15nh+4 from the cell supernatant following alkaline diffusion. several species of root nodule bacteria also exported large quantities of nh+4 from l-his ...19768100
6-phospho-d-gluconate:nad+ 2-oxidoreductase (decarboxylating) from slow-growing rhizobia.6-phospho-d-gluconate:nad+ 2-oxidoreductase (decarboxylating) (nad+-6pgd) was detected in several slow-growing strains of rhizobia, and no activity involving nadp+ was found in the same extracts. by contrast, fast-growing strains of rhizobia had nadp+-6pgd activity; most of them also had nad+-6pgd activity. nad+-6pgd was partially purified from the slow-growing strain rhizobium japonicum 5006. the reaction was shown to be an oxidative decarboxylation.197716867
the role of ammonia, l-glutamate, and cyclic adenosine 3',5'-monophosphate in the regulation of ammonia assimilation in rhizobium japonicum.the effects of three factors (ammonia, l-glutamate, and cyclic adenosine 3',5'-monophosphate) on the ammonia assimilatory processes in aerobically grown rhizobium japonicum colony derivatives were examined. ammonia repressed glutamine synthetase activity and increased the average state of adenylylation of this enzyme. the addition of l-glutamate drastically decreased growth and strongly repressed glutamate synthase levels. glutamine synthetase repression and adenylylation state were also increas ...197823179
effect of cyclic guanosine 3',5'-monophosphate on nitrogen fixation in rhizobium japonicum.the addition of exogenous cyclic guanosine 3',5'-monophosphate (cgmp) at a concentration of 0.1 mm to a free-living culture of rhizobium japonicum 3i1b110 was found to completely inhibit the expression of nitrogenase activity and markedly inhibit the expression of hydrogenase and nitrate reductase activities. the effect was specific for cgmp. experiments on the in vivo incorporation of radioactive methionine and subsequent analysis of the labeled proteins on polyacrylamide gels showed that the b ...197937237
purification and properties of the particulate hydrogenase from the bacteroids of soybean root nodules.the uptake hydrogenase (hydrogen:ferricytochrome c3 oxidoreductase, ec 1.12.2.1) from the bacteroids of soybean root nodules infected with rhizobium japonicum 110 has been purified and characterized. bacteroids were prepared, then broken by sonication. the particulate enzyme was solubilized by treatment with triton x-100 and further purified by polyethylene glycol fractionation, deae-cellulose and sephadex g-100 chromatography. the specific activity has been increased 196-fold to 19.6 units/mg p ...197940601
[proceedings: plasmids in rhizobium japonicum]. 197550812
immunofluorescent polar tips of rhizobium japonicum: possible site of attachment or lectin binding.rhizobium japonicum usda 31 demonstrated marked polarity by binding homologous fluorescent antibody (fa) heavily on one end of the cell. fa prepared against r. japonicum strains 110 and 138, and against r. trifolii ta1 cross-reacted with strain 31 only in the polar tip region. no polar immunofluorescing tips could be seen with fa against two other strains of r. japonicum or with those against several unrelated microorganisms. common antigens localized only in a polar region were seen in many rhi ...197656334
effect of lindane on radio-carbon (14c) incorporation by rhizobium japonicum.experiments conducted in vitro with three levels (1, 2, and 5 ppm active ingredient) of the insecticide lindane (gamma-bhc) showed no effect on the growth of rhizobium japonicum, but altered the incorporation of radio-carbon (14c-glucose) into the different constituents of the growing cells. while all the three levels of the insecticide significantly depressed the incorporation of radiocarbon in the alcohol-extractable fraction, with no effect on the alcohol-ether soluble fraction of the cells, ...197665064
effects of pesticide seed treatments on rhizobium japonicum and its symbiotic relationship with soybean.seventeen rhizobium japonicum cultures isolated from soybean nodules induced formation of nodules on taproots of soybean plants. all isolates reduced acetylene to ethylene to different extents in vitro. paper disc assay indicated that two insecticides, lindane (gamma-1,2,3,4,5,6-hexachlorocyclohexane), chlorpyrifos (o,o-diethyl o-3,5,6-trichloro-2-pyridyl phosphorothioate), and a fungicide, thiram (tetramethylthiuram disulphide) individually or in combination caused significant inhibition of the ...197770252
transfer of r factors to and between genetically marked sublines of rhizobium japonicum.plasmids r1822 and prd1 of the p-1 incompatibility group, for which rhizobium japonicum had not previously been shown to serve as host, were introduced into a strain of r. japonicum. acquisition of r68 and r68.45 plasmids by this rhizobium was equivocal. transfer of r1822 from pseudomonas aeruginosa and of prd1 from escherichia coli to r. japonicum was unambiguous, because the exconjugants subsequently cotransferred the three r-factor resistance determinants (kanamycin, tetracycline, and penicil ...1979114109
nitrate reductase activities of rhizobia and the correlation between nitrate reduction and nitrogen fixation.all species of rhizobium except r. lupini had nitrate reductase activity. only r. lupini was incapable of growth with nitrate as the sole source of nitrogen. however, the conditions necessary for the induction of nitrate reductase varied among species of rhizobium. rhizobium japonicum and some rhizobium species of the cowpea strains expressed nitrate reductase activities both in the root nodules of appropriate leguminous hosts and when grown in the presence of nitrate. rhizobium trifolii, r. pha ...1979119573
nitrogen fixing activity in rhizobium japonicum separated from plant cell cultures.induced by soy bean tissue cultures in socalled "tissue chambers", rhizobium japonicum str. 61-a-96 developed nitrogenase activity separated from the plant cells. the activity proceded for 48 h with a rate of 1 x 10(-8) nmol c2h4h-1 cell-1, which is about 6% of the activity measured for bacteroids from rhizobium japonicum in nodules of glycine max.1975130001
differentiation of rhizobium japonicum, i. enzymatic comparison of nitrogenase repressed and derepressed free living cells and of bacteroids.derepressed free living cells of rhizobium japonicum strain 61-a-101 with leucine as single nitrogen source develop a maximum nitrogenase activity of 180 nmol c2h4.mg protein -1.h-1 in liquid culture under 2% 2% o2 in the gas phase. only 10% of this activity is found with no oxygen in the gas phase during a 90 min incubation period. the maximum activity under 2% oxygen in the gas phase is unaffected by addition of 1-100 mm nh+4 and by addition of low concentrations of glutamine (0.36-1.44 mm). s ...1978149461
differentiation of rhizobium japonicum, iii. inhibition of nitrogenase derepression by chloramphenicol and rifampicin concentrations, not inhibiting growth.development of nitrogenase (40--140 nmol c2h4.mg protein-1.h-1) in rhizobium japonicum 61-a-101 after transfer to special culture conditions (medium 20 p, 2% o2, 10% co2, 88% n2 in the gas phase) is inhibited by chloramphenicol (6 x 10(-4)--10(-3) m) and by rifampicin (10(-5) m). these concentrations do not inhibit the slow growth of the cells under these conditions with a doubling time of the cell protein and living cell number of 3--5 d. nitrogenase activity of previously derepressed cells is ...1978154223
regulation of hydrogen utilisation in rhizobium japonicum by cyclic amp.utilisation (uptake) of hydrogen gas by whole cells of rhizobium japonicum was found to be influenced by the carbon source(s) present in the growth medium, with activity being highest in a medium containing sugars. tricarboxylic acid cycle intermediates, such as malate, significantly reduced h2 utilisation. no reduction in the hydrogenase activity is observed when the enzyme is assayed directly by the tritium exchange method, indicating that the decrease in hydrogen uptake activity is not due to ...1979222344
iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. electron paramagnetic resonance of the carbon monoxide inhibited state.carbon monoxide inhibits reduction of dinitrogen (n2) by purified nitrogenase from azotobacter vinelandii and clostridium pasteurianum in a noncompetitive manner (kii and kis = 1.4 x 10(-4) and 4.5 x 10(-4) and 7 x 10(-4) atm and 14 x 10(-4) atm for the two enzymes, respectively). the onset of inhibition is within the turnover time of the enzyme, and co does not affect the electron flux to the h2-evolving site. the kinetics of co inhibition of n2 reduction are simple, but co inhibition of acetyl ...1979228701
adsorption and selection of rhizobia with ion-exchange papers.ion exchange papers were used to study the adsorption of 32p-labelled rhizobia on defined surfaces. two strains of rhizobium japonicum and one each of r. leguminosarum and r. lupini were compared with escherichia coli and bacillus subtilis. the ratio of adsorption to strong and to weak acid papers/strong and weak basic papers was consistantly higher for all rhizobial strains compared to the other bacteria. the process of desorption by increasing the ion-concentration causes about 35% desorption ...1975242293
[production of soy bean inoculants. behavior of supports based on peat from tierra del fuego sterilized by vapor and ethylene oxide].the survival of rhizobium japonicum was studied in neutralized and sterilized peats from ushuaia and rio grande. the carriers were sterilized by ethylene oxide and by autoclaving. similar counts for rhizobium (5 x 10(8) cel/g) were obtained in peat-cultures sterilized by both methods, after eight months. a good nodulation and nitrogen fixation capacity was observed with inoculated soybean plants. using the strain rhizobium japonicum e-45, no appreciable difference in symbiotic effectiveness was ...1979263653
autotrophic growth of h2-uptake-positive strains of rhizobium japonicum in an atmosphere supplied with hydrogen gas.previous research from this laboratory has demonstrated co(2)-fixing and h(2)-uptake capacities of certain strains of rhizobium japonicum. in this report we have shown that sr, a h(2)-uptake-positive (hup(+)) strain of r. japonicum, is capable of autotrophic growth with h(2) as the energy source. growth occurred on mineral salts/vitamins/noble agar, mineral salts/vitamins liquid medium (0.27 mug of c as vitamins per ml), and in mineral salts liquid medium with no added vitamins when cultures wer ...1979287019
flow-microfluorometric analysis of escherichia coli, rhizobium meliloti, and rhizobium japonicum at different stages of the growth cycle.the applicability of flow-microfluorometry (fmf) to the study of bacterial samples was investigated on cultures of rhizobium meliloti, rhizobium japonicum, and escherichia coli using fluorescent and light-scattering signals. this technique which analyzes individual bacterial cells in a population was used to monitor the relative change in nucleic acid content and cell size during the growth cycle of the three microorganisms which were known to have different growth rates. early log-phase e. coli ...1977332295
introduction of potential sex factors into rhizobium japonicum. 1977411474
antibiotic resistance in rhizobium japonicum: implications for safety and interpretation of nif transfer from rhizobium. 1977411475
regulation of hydrogenase in rhizobium japonicum.factors that regulate the expression of an h2 uptake system in free-living cultures of rhizobium japonicum have been investigated. rapid rates of h2 uptake by r. japonicum were obtained by incubation of cell suspensions in a mg-phosphate buffer under a gas phase of 86.7% n2, 8.3% h2, 4.2% co2, and 0.8% o2. cultures incubated under conditions comparable with those above, with the exception that ar replaced h2, showed no hydrogenase activity. when h2 was removed after initiation of hydrogenase der ...1979422513
[lysogeny of rhizobium japonicum and the sensitivity of these cultures to phages isolated from soil].twenty cultures of rhizobium japonicum of various origin were tested for lysogeny using a cross technique with a preliminary uv induction and without it as well as by electron microscopy. none of the cultures was found in the lysogenic state. phages active against rh. japonicum were detected in four soil samples on which soybean plants were grown; 27 phages were isolated by the enrichment method and 3 phages without enrichment. the phages were capable of lysis of only rh. japonicum cultures and ...1979440166
multiple antibiotic resistance in rhizobium japonicum.a total of 48 strains of the soil bacterium rhizobium japonicum were screened for their response to several widely used antibiotics. over 60% of the strains were resistant to chloramphenicol, polymyxin b, and erythromycin, and 47% or more of the strains were resistant to neomycin and penicillin g, when tested by disk assay procedures. the most common grouping of resistances in strains was simultaneous resistance to tetracycline, penicillin g, neomycin, chloramphenicol, and streptomycin (25% of a ...1979485137
the biosynthesis of nitrogenase mofe protein polypeptides in free-living cultures of rhizobium japonicum.the biosynthesis of the constituent polypeptides of nitrogenase component i (rj 1) in free-living cultures of rhizobium japonicum (strain 110) was investigated under different growth conditions. cells were pulse-labelled and the proteins analysed by one and two-dimensional gel electrophoresis. the positions of the constituent rj 1 polypeptides were identified by co-electrophoresis with purified rj 1 isolated from bacteroids of soybean nodules, and by comparison with an immunoprecipitate from a c ...1979518887
salt tolerance of rhizobium species in broth cultures.salt tolerance of five rhizobia strains was examined in broth cultures. five levels of nacl concentration were used and the optical density was taken as a measure for the vigour of bacterial growth. rhizobium leguminosarum and r. meliloti were tolerant to high levels of salinity and growth curves in saline broth showed a similar pattern to the control level. rhizobium japonicum, cowpea rhizobium, and r. trifolii were intolerant to salt and showed a strong growth retardation with increasing salt ...1979547498
ultrastructure of soybean nodules. i: release of rhizobia from the infection thread.root nodules on soybeans (var. clark 63) were examined by transmission electron microscopy 10-12 days after seed inoculation and planting. the cell infection process appeared identical in both effective nodules, induced by rhizobium japonicum strain 138 (usda) and in ineffective nodules, induced by strain 8-0 (iowa). electron micrographs are presented which suggest that rhizobia are freed from the infection thread by disintegration of the thread wall and compartmentalization of the distintegrat ...1977559533
glucose catabolism in two derivatives of a rhizobium japonicum strain differing in nitrogen-fixing efficiency.radiorespirometric and enzymatic analyses reveal that glucose-grown cells of rhizobium japonicum isolates i-110 and l1-110, both derivatives of r. japonicum strain 3i1b110, possess an active tricarboxylic acid cycle and metabolize glucose by simultaneous operation of the embden-meyerhof-parnas and entner-doudoroff pathways. the hexose cycle may play a minor role in the dissimilation of glucose. failure to detect the nicotinamide adenine dinucleotide phosphate-dependent decarboxylating 6-phosphog ...1977559670
comparison of colony morphology, salt tolerance, and effectiveness in rhizobium japonicum.four strains of rhizobium japonicum, two of which produce slimy and non-slimy colony types and two others which produce large and small colony types, were isolated and cloned. all were infective and nodulated lee soybean host plants. each colony type was characterized as to its salt sensitivity to na+ and k+ ions, relative level of symbiotic nitrogen fixation, and relative level of free-living nitrogen fixation. growth studies performed in the presence of salts demonstrated that the non-slimy or ...1977561643
properties of the hydrogenase system in rhizobium japonicum bacteroids. 1978564190
grouping of rhizobial strains--a method based on symbiotic characteristics.twenty strains of rhizobium japonicum and non-inoculated control were used to study seven symbiotic characteristics with two varieties of soybean (glycine max). the strains were then grouped on the basis of these symbiotic characteristics, using mahalanobis' d2 statistical method. eight groups were formed in which two strains stood distinctly aloof, indicating thereby the exceptional nature of these strains over others in their symbiotic behaviour. this method is suggested for selecting exceptio ...1977565116
stepwise selection of efficient rhizobial cultures through cultural characteristics.nodulation and shoot nitrogen of two varieties of soybean (glycine max) were studied with twenty strains of rhizobium japonicum. a number of cultural characteristics of the strains in isolation to the symbiotic system were also studied. a stepwise selection method was employed for detecting efficient cultures through the cultural characteristics which showed association with the steps in the symbiotic system. nodulation of one variety was found to be associated with the dehydrogenase activity an ...1977565117
involvement of rhizobium japonicum o antigen in soybean nodulation.non-nodulating mutant strains of rhizobium japonicum lacked a surface antigen that was present on the wild type. this surface antigen is associated with the o antigen portion of the lipopolysaccharide. paper chromatography of hydrolyzed lipopolysaccharide and o antigen revealed three major component differences between the non-nodulating strains and the wild type.1978565351
ultrastructure of rhizobium japonicum in relation to its attachment to root hairs.in rhizobium japonicum strain nitragin 61a76, morphologically distinct types of bacteria were found to occur in yeast extract-mannitol broth cultures, at both mid-log and stationary phases. of these only the capsular form, characterized by a smooth cell envelope, storage granules (glycogen and poly-beta-hydroxybutyric acid), and an amorphous extracellular capsule, bound soybean lectin. the binding site was localized in the capsular material. less than 1% of the bacterial population differentiate ...1978565352
hydrogen evolution and uptake by nodules of soybeans inoculated with different strains of rhizobium japonicum.hydrogen evolved by nitrogenase may be recycled by a hydrogenase present in some legume nodules. anoka and portage cultivars of soybeans were inoculated with each of 8 and 24 strains, respectively, of rhizobium japonicum and surveyed for h2 evolution and c2h2 reduction rates nodule weight, and plant dry weight. six of the strains (3ilb 110, usda 122, usda 136, 3ilb 6, 3ilb 142, and 3ilb 143) which exhibited no h2 evolution in air were shown to take up h2. the relative efficiencies of nitrogenase ...1978565672
role of lectins in plant--microorganism interactions. iv. ultrastructural localization of soybean lectin binding sites of rhizobium japonicum.the binding of purified, ferritin-labeled soybean seed lectin to the cell surfaces of rhizobium japonicum 31 lb 138 has been examined by whole mount, thin section, and freeze-etch electron microscopy. the ferritin-labeled lectin binds in a biochemically specific manner to the capsular material of this bacterium. the lectin does not bind to the outer membranes of the cells or to flagella. labeled lectin binds to sites throughout the capsular structure, although the density of labeling is somewha ...1978567091
[determination of the nitrogen-fixing activity of rhizobium japonicum under sterile microvegetative conditions].the nitrogen fixing activity of rhizobium japonicum in symbiosis with soya grown in the sterile microvegetative conditions at an air humidity of 70%, at a temperature of 20 degrees c and a length of light day of 16 hours was assayed using the acetylene technique. the plants were cultivated in phytotron in glass tubes (245 cm3) illuminated with xenon lamps. this technique can be used, apparently, to determine the nitrogen fixing activity of other legumes and cereals.1978568711
efficiency of rhizobium japonicum strains as affecting nitrate reductase and dehydrogenase activities of the soybean nodules. 1978569408
genetically marked rhizobium identifiable as inoculum strain in nodules of soybean plants grown in fields populated with rhizobium japonicum.the fate of an inoculum strain of rhizobium japonicum was studied using a genetically marked strain i-11o subline carrying resistance markers for azide, rifampin, and streptomycin (i-110 ars). at the time of planting into a field populated with r. japonicum, seeds of soybean cultivars kent and peking were inoculated with varying cell densities of strain i-110 ars. at various times during the growing season, surface-sterilized root nodules were examined for the presence of the inoculum strain by ...1978570015
bacteriocin-like substances produced by rhizobium japonicum and other slow-growing rhizobia.bacteriocin-like substances were commonly produced by slow-growing rhizobium japonicum and cowpea rhizobia on an l-arabinose medium. antagonism between strains of r. japonicum was not detected in vitro; however, such strains were often sensitive to some bacteriocins produced by cowpea rhizobia. inhibitory zones (2 to 8 mm from colony margins), produced by 58 of 66 r. japonicum test strains, were reproducibly detected with corynebacterium nebraskense as an indicator. quantitative production was n ...1978570016
influence of soybean inoculation and nitrogen levels on populations and serogroups of rhizobium japonicum in ontario. 1979573169
[preparation of a nitrogen-fixing association between rhizobium japonicum and soybean root callus]. 1979574185
studies on nodulation of soyabeans in egypt. ii. effect of seed-diffusates on rhizobium japonicum.the growth inhibition zones of r. japonicum (e 45) by either surface-sterilized seeds or autoclaved seeds (as well as dicotyledones, cotyledone, or seed coat) of harosoy soyabean cultivar indicate the presence of antibacterial substances. several physical and chemical seed treatments were done in a trial to eliminate or decrease the observed inhibitive effects of the seed-diffusates in order to obtain successful nodulation. the antibacterial substances are thermostable (121 degrees c), water-sol ...1979575837
studies on nodulation of soyabean in egypt. i. selection of an efficient strain of rhizobium japonicum.both pot (sterilized sand cultures) and field experiments were run, using 23 different strains of rhizobium japonicum and the commercial soyabean inoculum "okadin". the failure of the control (non-inoculated plants) to form nodules may be due to the abscence of adequate densities of effective soyabean-rhizobia strains and their low persistence under egyptian soil conditions. therefore, inoculation with an efficient strain of r. japonicum seemed to be necessary. however, the strains used varied i ...1979583638
purification and characterisation of d-amino acid aminotransferase from rhizobium japonicum.rhizobium japonicum has d-amino acid aminotransferase and alanine racemase activities. the d-amino-acid aminotransferase has been partially purified and characterized. this enzyme has a broad specificity and is very active with d-alpha-aminobutyrate and d-aspartate as well as d-alanine and d-glutamate. the stereospecificity of the enzyme for d-amino acids was apparently absolute with respect to product inhibition, pyridoxamine formation as well as catalytic activity. the apparent molecular weigh ...1978620041
transfer from rhizobium japonicum to azotobacter vinelandii of genes required for nodulation.a mutant strain of azotobacter vinelandii that is unable to fix n2 (nif-) was transformed to nif+ with dna from rhizobium japonicum. of 50 nif+ transformants tested, 3 contained the o antigen-related polysaccharide that is present on the cell surface of a nodulating r. japonicum strain, but is absent from a non-nodulating mutant strain.1978659367
interaction between rhizobium japonicum phage m-1 and its receptor.the receptor for phage m-1 was present in the exopolysaccharide (eps) of rhizobium japonicum d211. the eps was a heteropolysaccharide consisting of glucose, galactose, glucuronic acid, and glucosamine units. these monosaccharides prevented phage-cell attachment indicating that they may mimick the receptor. phage-cell attachment was either stimulated or inhibited by mg2+ and ca2+ depending upon their concentration. an enzyme which depolymerized the exopolysaccharide releasing oligosaccharides was ...1978667736
stimulation of tetrapyrrole formation in rhizobium japonicum by restricted aeration.cultures of rhizobium japonicum were grown with vigorous aeration to stationary phase and were then incubated under restricted aeration for several days. under these "microaerobic" conditions, cellular heme content increased 10-fold, and visible amounts of porphyrins were released into the culture medium. the two predominant porphyrins produced were identified, on the basis of their spectrophotometric and chromatographic properties, as protoporphyrin and coproporphyrin. the cytochrome complement ...1978690074
hydrogen-dependent nitrogenase activity and atp formation in rhizobium japonicum bacteroids.rhizobium japonicum 122 des bacteroids from soybean nodules possess an active h(2)-oxidizing system that recycles all of the h(2) lost through nitrogenase-dependent h(2) evolution. the addition of 72 mum h(2) to suspensions of bacteroids increased o(2) uptake 300% and the rate of c(2)h(2) reduction 300 to 500%. the optimal partial pressure of o(2) was increased, and the partial pressure of o(2) range for c(2)h(2) reduction was extended by adding h(2). a supply of succinate to bacteroids resulted ...1979762010
the molybdenum--iron protein of klebsiella pneumoniae nitrogenase. evidence for non-identical subunits from peptide 'mapping'.the molybdenum- and iron-containing protein components of nitrogenase purified from klebsiella pneumoniae, azotobacter vinelandii, azotobacter chroococcum and rhizobium japonicum bacteroids all gave either one or two protein-staining bands after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, depending on the commercial brand of sodium dodecyl sulphate used. the single band obtained with k. pneumoniae mo-fe protein when some commercial brands of sodium dodecyl sulphate were used in t ...1976779772
immunological evidence for the capability of free-living rhizobium japonicum to synthesize a portion of a nitrogenase component.immunodiffusion tests conducted under aerobic conditions demonstrated that cross-reactive material to antiserum prepared against the mo-fe protein component of nitrogenase from soybean nodule bacteroids was detectable in extracts of free-living rhizobium japonicum cells cultured in a standard medium under: aerobic conditions; aerobic conditions with nitrate; aerobic conditions with ammonia; anaerobic conditions with nitrate; and anaerobic conditions with nitrate and ammonia. the most intense pre ...1975803382
discrimination of rhizobium japonicum, rhizobium lupini, rhizobium trifolii, rhizobium leguminosarum and of bacteroids by uptake of 2-ketoglutaric acid, glutamic acid and phosphate.rhizobium strains (one each of rh. japonicum, rh. lupini, rh. leguminosarum) take up 2-ketoglutaric acid in general much faster and from lower concentrations in the medium than strains of escherichia coli, bacillus subtilis and chromobacterium violaceum. a strain of enterobacter aerogenes, however, is more similar to some rhizobium strains. the same strains of rhizobium take up also phosphate much faster and from lower concentrations than the other bacteria tested. 4 strains of rh. lupini proved ...1976818969
some features of mannitol metabolism in rhizobium japonicum. 1977833572
polarity in the exponential-phase rhizobium japonicum cell.highly distinctive aspects of the exponentail-phase rhizobium japonicum cell were disclosed by means of thin sections, freeze etching, fluorescent antibodies, and ruthenium red staining. polarity was expressed in the form of reserve polymer distribution near one end of the cell and as cytoplasmic localization near the opposite end. in addition, exocellular polysaccharide (eps) accumulated preferentially around the cytoplasmic end, and the feature described previously as an "immunofluorescent pol ...1977907920
oxygen requirement for acetylene reduction by pure cultures of rhizobia.the oxygen and nutritional requirements for acetylene reduction by rhizobium japonicum and rhizobium sp. in liquid culture are described. the optimal oxygen concentration was about 0.1% in the gas phase, which is lower than that of any other known aerobic nitrogen-fixing microorganism. these organisms are also unique in that nitrogenase synthesis is not repressed in the presence of ammonium chloride under certain cultural conditions, in contrast to other wild-type bacteria.1976931945
ineffective and non-nodulating mutant strains of rhizobium japonicum.mutant strains of rhizobium japonicum that were unable to allow the corsoy cultivar of soybean to reduce acetylene or fix n2 were isolated. these strains grow as well as the wild type in a variety of media. mutant strains sm1 and sm2 did not form nodules on the host plant; however, they reduced acetylene in the nonsymbiotic assay. strains sm3 and sm4 produced nodules that did not have the characteristic pink pigment caused by leghemoglobin. the nodules formed by these strains also were small. on ...1976986388
rhizobium japonicum derivatives differing in nitrogen-fixing efficiency and carbohydrate utilization.four derivatives of rhizobium japonicum 110 were isolated on the basis of morphologically different colonies formed on yeast extract-mannitol-hm salts medium. all are able to nodulate lee soybeans. the bacteria-plant associations formed by each clone have measurable acetylene-reducing activity, but those formed by two of these clones (designated l1-110 and l2-110) are 5- to 10-fold less efficient than those formed by the others (designated i-110 and s-110). these derivatives were not detectable ...1976988784
nitrate reductase from anaerobically grown rhizobium japonicum.the activity of nitrate reductase in rhizobium japonicum is controlled by oxygen tension, and not by nitrate. the enzyme from r. japonicum grown anaerobically in the presence of nitrate resembles that from bacteroids in having a molecular weight of about 69000 daltons; the enzyme from aerobically grown cells ahs a molecular weight of about 170000 daltons. both types of enzyme have similar km values, but differ in their sensitivity to kcn.1976993777
physical evidence of a plasmid in rhizobium japonicum. 19751140246
acetylene reduction by transfilter suspension cultures of rhizobium japonicum. 19751169944
involvement of oxyleghaemoglobin and cytochrome p-450 in an efficient oxidative phosphorylation pathway which supports nitrogen fixation in rhizobium.cellular atp level, atp/adp ratio and nitrogenase activity rise when oxyleghaemoglobin is added to respiring suspensions of rhizobium japonicum bacteroids from soybean root nodules. increased gaseous o2 tension is much less efficient than oxyleghaemoglobin in stimulation of bacteroid atp production. studies with the inhibitor carbonyl cyanide m-chlorophenylhydrazone show this atp to be generated as a consequence of oxidative phosphorylation. n-phenylimidazole, a specific cytochrome p-450 inhibit ...19751169973
nitrate reductase from bacteroides of rhizobium japonicum: enzyme characteristics and possible interaction with nitrogen fixation.the soluble nitrate reductase of rhizobium japonicum bacteroids has been purified and its properties compared to those of aerobically grown cells. the enzymes from both sources are similar with molecular weights of about 70 000 suggesting no close relationship with the molybdo-protein component of nitrogenase. nitrite, the product of nitrate reductase, strongly inhibited the nitrogenase activity from bacteroids, at concentrations less than 100 mum. thus, an interference in the rate of nitrogen f ...19751170894
role of pectic and cellulolytic enzymes in the invasion of the soybean by rhizobium japonicum.past workers have suggested pectic enzyme involvement in the invasion of legumes by rhizobium. however, no role for pectic acid, pectin, or methyl cellulose depolymerase enzymes in the invasion of r. japonicum was suggested by the current study. seedling inoculation with infective bacteria did not result in increased enzyme activity. rhizobium japonicum cell-free culture extracts and 3-indoleacetic acid did not affect the activation, induction, or binding of these enzymes.19751172457
effect on microorganisms of volatile compounds released from germinating seeds.volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source. growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium. volatiles caused increased growth of pseudomonas fluorescens, bacillus cereus, erwinia carotovora, agrobacterium tumefaciens, a. radiobacter, rhizobium japonicum, mucor muc ...19751201509
leghaemoglobin and the supply of o2 to nitrogen-fixing root nodule bacteroids: presence of two oxidase systems and atp production at low free o2 concentration.studies of rates of consumption of dissolved o2 by suspensions of bacteroids (rhizobium japonicum, strain cb1809) from soybean root nodules showed the presence of two different terminal oxidase systems. a high-affinity system, sensitive to inhibition by n-phenylimidazole and by carbon monoxide, was most active when the dissolved o2 was between 0-01 and 0-1 mum. at 1 mum-o2 or higher, this oxidase system had little activity and o2 was consumed largely by a low-affinity system insensitive to these ...19751239489
glycerol metabolism in rhizobium.four strains of rhizobium japonicum and one strain of r. trifolii were grown on glycerol and found to contain a soluble atp-glycerol kinase and a particulate glycerolphosphate dehydrogenase. both enzymes are induced by glycerol. the presence of nad+-or nadp+-glycerol dehydrogenase was not detected in any of the strains. no significant differences were found in the glycerol metabolic pathway between fast-and slow-growing rhizobia.19761260522
genetic mapping of leucine and isoleucine-valine loci in rhizobium japonicum.leucine and isoleucine-valine loci have been mapped in rhizobium japonicum. transformation analysis suggests a common pathway for isoleucine-valine biosynthesis. three-point reciprocal crosses indicated that all the leucine loci are not genetically linked.19761262320
p-450 hemeproteins of rhizobium japonicum. purification by affinity chromatography and relationship to p-450cam and p-450lm-2. 19761267795
nucleotide sequences of membrane-bound hydrogenase gene in alcaligenes hydrogenophilus.the nucleotide sequences of membrane-bound hydrogenase small (hups) and large (hupl) subunit genes of hydrogen bacterium alcaligenes hydrogenophilus were determined. the hups and hupl genes encoded polypeptides of 363 and 619 amino acids, respectively. the hups was located upstream of hupl with 35bp of intergenic region. the consensus ribosome-binding sequences were identified upstream of the start codons of hups and hupl. amino acid sequence of hups is very similar to that of rhodobacter capsul ...19921294332
isolation and characterization of rhizobitoxine mutants of bradyrhizobium japonicum.to explore the role of rhizobitoxine in bradyrhizobium-legume symbiosis, 11 rhizobitoxine mutants of b. japonicum usda61 were isolated on the basis of their inability to synthesize the toxin in culture. each mutant is prototrophic and symbiotically effective on soybean, cowpea, siratro, and glycine soja. the rhizobitoxine mutants differ in their chlorosis phenotypes and rhizobitoxine production in planta. as expected, one group of mutant fail to make toxin in planta, resulting in the absence of ...19921317377
dissociation by nh4cl treatment of the enzymic activities of glutamine synthetase ii from rhizobium leguminosarum biovar viceae.glutamine synthetase ii (gsii) was purified to homogeneity from rhizobium leguminosarum biovar viceae and characterized. the sequence of 26 amino acid residues from the amino-terminal end of the protein showed high similarity with the sequence of gsii from bradyrhizobium japonicum or from rhizobium meliloti. non-denaturing page showed that gsii, either in crude extracts or in the pure state, was a mixture of an octamer and a tetramer and that under specific conditions the octamer/tetramer ratio ...19921355107
phylogeny of fast-growing soybean-nodulating rhizobia support synonymy of sinorhizobium and rhizobium and assignment to rhizobium fredii.we determined the sequences for a 260-base segment amplified by the polymerase chain reaction (corresponding to positions 44 to 337 in the escherichia coli 16s rrna sequence) from seven strains of fast-growing soybean-nodulating rhizobia (including the type strains of rhizobium fredii chemovar fredii, rhizobium fredii chemovar siensis, sinorhizobium fredii, and sinorhizobium xinjiangensis) and broad-host-range rhizobium sp. strain ngr 234. these sequences were compared with the corresponding pre ...19921371066
identification and cloning of bradyrhizobium japonicum genes expressed strain selectively in soil and rhizosphere.the growth of bradyrhizobium japonicum usda 110 and usda 438 in soil extract-supplemented medium led to transcription of a large amount of dna not expressed in basal medium. strain usda 438 was more competitive for the nodulation of soybean than strain usda 110. to identify and isolate dna regions which were expressed specifically in strain usda 438 but not in strain usda 110 in response to soil extract or soybean root exudate, we developed a subtractive rna hybridization procedure. several cosm ...19921377899
evidence for a close genealogical relationship between afipia (the causal organism of cat scratch disease), bradyrhizobium japonicum and blastobacter denitrificans.the primary structures of the small subunit rrna of bradyrhizobium japonicum and blastobacter denitrificans were determined by direct sequencing of enzymatically amplified dna. comparative sequence analysis revealed that bradyrhizobium japonicum and blastobacter denitrificans are members of the alpha-2 subgroup of the proteobacteria and show a very close phylogenetic relationship with the genus afipia.19921383084
incorporation of a bacterial membrane-bound hydrogenase into proteoliposomes.membrane-bound nickel-iron hydrogenases from diverse genera of bacteria have been previously characterized and they are closely related. we report the reconstitution of purified bradyrhizobium japonicum hydrogenase into proteoliposomes by a detergent dialysis method followed by two or three cycles of freeze-thaw. sedimentation experiments revealed that more than 60% of the h2-uptake activity was particulate when reconstituted into escherichia coli phospholipids. sucrose-gradient centrifugation s ...19921384385
a succinate transport mutant of bradyrhizobium japonicum forms ineffective nodules on soybeans.biochemical evidence has shown that dicarboxylic acids actively support symbiotic nitrogen fixation by both fast- and slow-growing rhizobium. mutants defective in the active uptake of succinate have been previously described only in species of the fast-growing rhizobium. this article is a report on the isolation of mutants defective in dicarboxylate transport in a slow-growing species of rhizobium, bradyrhizobium japonicum. one of these presumptive dicarboxylate transport mutants, gts, was chara ...19921393826
structures of the oligosaccharides obtained from the core regions of the lipopolysaccharides of bradyrhizobium japonicum 61a101c and its symbiotically defective lipopolysaccharide mutant, js314.the only core oligosaccharide released from the lipopolysaccharide (lps) of bradyrhizobium japonicum 61a101c by prolonged (5 h) mild hydrolysis with acid, and the major core oligosaccharide obtained from its symbiotic and lps-defective mutant, js314, was the trisaccharide alpha-d-man p-(1----4)-alpha-d-glc p-(1----4)-2,7-anhydro-alpha-kdof. the 2,7-anhydro-3-deoxy-alpha-d-manno-2- octulofuranosonic acid moiety was probably formed during the prolonged mild hydrolysis with acid. a disaccharide cor ...19921394315
role of integration host factor in stimulating transcription from the sigma 54-dependent nifh promoter.in a wide variety of nitrogen-fixing organisms among the purple bacteria (large division of gram-negative bacteria) the nitrogen fixation (nif) operons are transcribed by an alternative holoenzyme form of rna polymerase, sigma 54-holoenzyme. transcription depends on the activator protein nifa (nitrogen fixation protein a), which catalyzes isomerization of closed complexes between this polymerase and a promoter to transcriptionally productive open complexes. nifa-mediated activation of transcript ...19921404379
isolation and characterization of an ndvb locus from rhizobium fredii.a gene (ndvb) in rhizobium meliloti that is essential for nodule development in medicago sativa (alfalfa), specifies synthesis of a large membrane protein. this protein appears to be an intermediate in beta-1,2-glucan synthesis by the microsymbiont. southern hybridization analysis showed strong homology between an ndvb (chvb) probe and genomic dna of r. fredii but not from bradyrhizobium japonicum. a cosmid clone containing the putative ndvb locus was isolated from a rhizobium fredii gene librar ...19921406255
structural and functional analysis of two different nodd genes in bradyrhizobium japonicum usda110.bradyrhizobium japonicum has two closely linked homologs of the nodulation regulatory gene, nodd; these homologs are located upstream of and in divergent orientation to the nodyabcsuij gene cluster. we report here the nucleotide sequence and mutational analyses of both nodd copies. the predicted nodd1 and nodd2 proteins shared 62% identical amino acid residues at corresponding positions and exhibited different degrees of homology with nodd proteins of other bradyrhizobium, azorhizobium, and rhiz ...19921421512
genetic relatedness of bradyrhizobium japonicum field isolates as revealed by repeated sequences and various other characteristics.forty-nine isolates of bradyrhizobium japonicum indigenous to a field where soybeans were grown for 45 years without inoculation were characterized by using four dna hybridization probes from b. japonicum. nifdk-specific hybridization clearly divided the isolates into two divergent groups. diversity in repeated-sequence (rs)-specific hybridization was observed; 44 isolates derived from 41 nodules were divided into 33 different rs fingerprint groups. cluster analysis showed that the rs fingerprin ...19921444394
genes for a second terminal oxidase in bradyrhizobium japonicum.bradyrhizobium japonicum possesses a mitochondria-like respiratory chain terminating with an aa3-type cytochrome c oxidase. the gene for subunit i of this enzyme (coxa) had been identified and cloned previously via heterologous hybridization using a paracoccus denitrificans dna probe. in the course of these studies, another b. japonicum dna region was discovered which apparently encoded a second terminal oxidase that was different from cytochrome aa3 but also belonged to the superfamily of heme/ ...19921444719
differential expression of nods accounts for the varied abilities of rhizobium fredii usda257 and rhizobium sp. strain ngr234 to nodulate leucaena spp.transfer of a cosmid containing nodsu from rhizobium sp. ngr234 to rhizobium fredii usda257 expands the host range for nodulation to include the perennial tropical legumes, leucaena leucocephala and leucaena diversifolia. complementation experiments with a series of subclones established that nods and its associated nod-box promoter from ngr234 are sufficient to confer this extended host-range phenotype to l. leucocephala. strain usda257 contains its own copy of nodsu, including upstream nod-box ...19921484488
nickel-dependent reconstitution of hydrogenase apoprotein in bradyrhizobium japonicum hupc mutants and direct evidence for a nickel metabolism locus involved in nickel incorporation into the enzyme.a double mutant (jh103k10) was created from hydrogenase constitutive mutant (jh103) by replacement of a chromosomal 0.60 kb nickel metabolism related locus with a kanamycin resistance gene. the double mutant required 10 to 20 times more nickel (ni) to achieve near parental strain levels of hydrogenase activity. in the absence of nickel, both jh103k10 and jh103 synthesized high levels of (inactive) hydrogenase apoprotein (large subunit, 65 kda). with nickel, the double mutant jh103k10 synthesized ...19921503531
similarities between legume-rhizobium communication and steroid-mediated intercellular communication in vertebrates.regulation of the actions of flavonoids and nod factors in legume-rhizobia communication has several interesting similarities with that of steroid-mediated actions in vertebrates. oxidation or reduction of flavonoids and nod factors modifies their biological activity just as, for example, oxidation of an alcohol at c11 on hydrocortisone regulates its biological activity. second, some flavonoids are anti-inducers, functioning like steroid antagonists to negate the actions of inducer flavonoids. a ...19921504919
analysis of dna sequences transcribed at high levels in bradyrhizobium japonicum bacteroids but not necessary for symbiotic effectiveness.five regions of the bradyrhizobium japonicum genome, which are transcribed at high levels in nitrogen-fixing soybean (glycine max) nodules, were identified. none of these regions contained previously identified genes (e.g., nif, nod, and fix genes) that are known to be essential for development of functional nitrogen-fixing nodules. to assess the role of these regions in the development of the b. japonicum-soybean symbiosis, we cloned and used them to construct b. japonicum strains, in which lar ...19921515666
a 2-o-methylfucose moiety is present in the lipo-oligosaccharide nodulation signal of bradyrhizobium japonicum.bradyrhizobium japonicum is a soil bacterium that forms nitrogen-fixing nodules on the roots of the agronomically important legume soybean. microscopic observation of plant roots showed that butanol extract of b. japonicum strain usda110 cultures induced for nod gene expression elicited root hair deformation, an early event in the nodulation process. the metabolite produced by b. japonicum responsible for root hair deformation activity was purified. chemical analysis of the compound revealed it ...19921528893
characterization of a fixlj-regulated bradyrhizobium japonicum gene sharing similarity with the escherichia coli fnr and rhizobium meliloti fixk genes.we describe the cloning, sequencing, regulation, and mutational analysis of a bradyrhizobium japonicum fixk-like gene whose product belongs to the family of fnr-crp-related regulatory proteins. the predicted 237-amino-acid fixk protein was found to share between 28 and 38% sequence identity with the escherichia coli fnr protein, other bacterial fnr-like proteins (fnrn, anr, and hlyx), and two rhizobial fixk proteins. the b. japonicum fixk-like gene, when expressed from a lac promoter, could func ...19921551834
functional analysis of the cysteine motifs in the ferredoxin-like protein fdxn of rhizobium meliloti involved in symbiotic nitrogen fixation.the rhizobium meliloti fdxn gene, which is part of the nifa-nifb-fdxn operon, is absolutely required for symbiotic nitrogen fixation. the deduced sequence of the fdxn protein is characterized by two cysteine motifs typical of bacterial-type ferredoxins. the fix-phenotype of an r. meliloti fdxn::[tc] mutant could be rescued by the r. leguminosarum fdxn gene, whereas no complementation was observed with nif-associated genes encoding ferredoxins from bradyrhizobium japonicum, azotobacter vinelandii ...19921603075
isoliquiritigenin, a strong nod gene- and glyceollin resistance-inducing flavonoid from soybean root exudate.isoflavonoid signal molecules from soybean (glycine max (l.) merr.) seed and root exudate induce the transcription of nodulation (nod) genes in bradyrhizobium japonicum. in this study, a new compound with symbiotic activity was isolated from soybean root exudate. the isolated 2',4',4-trihydroxychalcone (isoliquiritigenin) is characterized by its strong inducing activity for the nod genes of b. japonicum. these genes are already induced at concentrations 1 order of magnitude below those required ...19921622242
hyperreiterated dna regions are conserved among bradyrhizobium japonicum serocluster 123 strains.we have identified and cloned two dna regions which are highly reiterated in bradyrhizobium japonicum serocluster 123 strains. while one of the reiterated dna regions, pfr2503, is closely linked to the b. japonicum common and genotype-specific nodulation genes in strain usda 424, the other, pmap9, is located next to a tn5 insertion site in a host-range extension mutant of b. japonicum usda 438. the dna cloned in pfr2503 and pmap9 are reiterated 18 to 21 times, respectively, in the genomes of b. ...19921622264
characterization of a bradyrhizobium japonicum ferrochelatase mutant and isolation of the hemh gene.a tn5-induced mutant of bradyrhizobium japonicum, strain lorbf1, was isolated on the basis of the formation of fluorescent colonies, and stable derivatives were constructed in backgrounds of strains lo and i110. the stable mutant strains loek4 and i110ek4 were strictly dependent upon the addition of exogenous hemin for growth in liquid culture and formed fluorescent colonies. the fluorescent compound was identified as protoporphyrin ix, the immediate precursor of protoheme. cell extracts of stra ...19921624416
characterization of a soluble catalase-peroxidase hemoprotein b-590, previously identified as 'cytochrome alpha 1' from bradyrhizobium japonicum bacteroids.the cytochrome "a1" or p-428, previously proposed to be a high affinity terminal oxidase in nitrogen-fixing bacteroids of bradyrhizobium japonicum has been purified. the water-soluble native hemoprotein has an mr of 136,000, lacks heme a and is a high-spin ferric protohemoprotein: it is slowly reduced with dithionite to give a species with an optical spectrum like that of hemoprotein b-590 (escherichia coli; peak at 555 nm, shoulder at 590 nm), and which reacts slowly with co. it has catalase an ...19911645695
from one gene to two proteins: the biogenesis of cytochromes b and c1 in bradyrhizobium japonicum.genes coding for polyproteins that are cleaved posttranslationally into two or more functional proteins are rarely found in prokaryotes. one example concerns the biogenesis of the bradyrhizobium japonicum cytochromes b and c1, two of the three constituent subunits of ubiquinol-cytochrome-c reductase (ubiquinol:ferricytochrome-c oxidoreductase, ec 1.10.2.2); the respective apoproteins for these subunits are encoded by the 5' and 3' halves of a single gene, fbch. these two halves are linked by an ...19911647023
polygalacturonase is a virulence factor in agrobacterium tumefaciens biovar 3.agrobacterium tumefaciens biovar 3 causes both crown gall and root decay of grapes. all biovar 3 strains, regardless of their tumorigenicity, produce in culture a single polygalacturonase with a pi around 4.5. a. tumefaciens biovar 3 strain cg49 was mutagenized with tn5 by using psup2021 as a suicide vector. a mutant strain, cg50, lacking polygalacturonase activity was isolated. the mutation was due to a single tn5 insertion in an 8.5-kb ecori fragment that also contained the polygalacturonase s ...19911655716
the bradyrhizobium japonicum cycm gene encodes a membrane-anchored homolog of mitochondrial cytochrome c.mitochondrial cytochrome c is a water-soluble protein in the intermembrane space which catalyzes electron transfer from the cytochrome bc1 complex to the terminal oxidase cytochrome aa3. in bradyrhizobium japonicum, a gene (cycm) which apparently encodes a membrane-anchored homolog of mitochondrial cytochrome c was discovered. the apoprotein deduced from the nucleotide sequence of the cycm gene consists of 184 amino acids with a calculated mr of 19,098 and an isoelectric point of 8.35. at the n- ...19911657867
identification of a novel composite transposable element, tn5280, carrying chlorobenzene dioxygenase genes of pseudomonas sp. strain p51.analysis of one of the regions of catabolic plasmid pp51 which encode chlorobenzene metabolism of pseudomonas sp. strain p51 revealed that the tcba and tcbb genes for chlorobenzene dioxygenase and dehydrogenase are located on a transposable element, tn5280. tn5280 showed the features of a composite bacterial transposon with iso-insertion elements (is1066 and is1067) at each end of the transposon oriented in an inverted position. when a 12-kb hindiii fragment of pp51 containing tn5280 was cloned ...19911657878
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