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[free amino acids of the nodule bacteria of clover in pure culture and under symbiotic conditions]. 1979514101
a new site-specific endonuclease showing phenotypical crypticity in a tumorigenic strain of agrobacterium tumefaciens.atubvi, an endonuclease showing new site-specificity, has been isolated from the tumorigenic strain iibv7 of agrobacterium tumefaciens, and is undetectable in the non-tumorigenic sister strain iibnv6. atubvi degrades iibv7 dna in vitro and should, therefore, be regarded as being phenotypically cryptic in the bacterial cell; it also shows anomalous behavior under cerain incubation conditions. these properties point to a possible role for this enzyme in the insertion of exogenous ti-plasmid dna in ...1979478298
purification and properties of d-glucosaminate dehydratase from agrobacterium radiobacter. 1979477973
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
host range conferred by the virulence-specifying plasmid of agrobacterium tumefaciens.the host range of agrobacterium tumefaciens 1d1109, known to induce crown gall only on grapevine (vitis spp.), was extended to include many plant species by transferring a tumor-inducing plasmid (pti) from strain 1d1, a broad-host-range pathogen. the pti plasmid was mobilized by the conjugative plasmid prk2, which was inserted into 1d1 by mating with escherichia coli j53(prk2). the resulting transconjugants were screened for their ability to induce crown gall tumors on hosts other than grapevine ...1979457613
indoleacetic acid production: a plasmid function of agrobacterium tumefaciens c58. 1979496970
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
choriogonadotropin-like antigen in an anaerobic bacterium, eubacterium lentum, isolated from a rectal tumor.using the indirect fluorescein-labeled and indirect peroxidase-antiperoxidase-labeled immunohistochemical techniques, and utilizing both antiserum specific for the beta-subunit of choriogonadotropin and antiserum for the total hormone, we have demonstrated the presence of a choriogonadotropin-like immunoreactive material in a strain of eubacterium lenthum that was originally isolated from a rectal tumor. in contrast, both immunohistochemical reactions were negative when applied to a strain of co ...1979468380
selective infection of maize roots by streptomycin-resistant azospirillum lipoferum and other bacteria.the percentage of low-level streptomycin-resistant (20 microgram/ml) bacteria in surface-sterilized or washed maize roots was more than a thousand times higher than that in soil populations. there was also a higher incidence of resistant bacteria in rhizosphere as compared with non-rhizosphere soil and bacteria isolated from maize roots were relatively tolerant to several other antibiotics. azospirillum lipoferum was predominant in surface-sterilized roots of field-grown maize and was low-level ...1979540253
association between azotobacter and other soil bacteria and its effect on nitrogen fixation.the association between a. vinelandii and either agrobacterium sp. or micrococcus sp., which are usually found as contaminants in azotobacter cultures, was investigated. in comparison with pure cultures, association increased the microbiol counts in addition to increasing nitrogen fixation rates and efficiency. in liquid cultures higher azotobacter densities were observed in the top 5 cm of the column concomitant with lowering the economic coefficient of utilization of carbonaceous compounds, wh ...1979543344
[the spreading of agrobacterium strains in soft-agar (author's transl)].in a diluted synthetic medium solidified by 0.17% agar populations of agrobacterium spread with a velocity of 0 to 20 mm/24 hours. this spreading is a consequence of chemotactic movement and cell division. different bacterial strains spread with a characteristic velocity each. loss of the ti-plasmid leaves the spreading behaviour unimpaired. it is changed after the introduction of virulence by kerr transfer or after prolonged culture in d-amino acids.1979543348
a study of the tumorogenesis of agrobacterium tumefaciens conn. on some plant species of iran.this paper is a survey and comparative type of study on the tumorogenetic effect of agrobacterium tumefaciens on some plant species of iran. the results obtained indicate that the tumor-inducing property of this micro-organism is not common to all plant species studied; moreover no tumor was initiated on the mature leaves by the bacteria. the results obtained with the local varieties of the susceptible plants show some qualitative and quantitative differences as compared with the works of other ...1979545942
[effect of indolylacetic acid on formation of bacteroid forms of rhizobium leguminosarum].the purpose of this work was to study the effect of indolylacetic acid (iaa) on the strains of rhizobium leguminosarum, effective and noneffective with respect to symbiotic nitrogen fixation (l4 and 245a, and 14--73, respectively). iaa at a concentration of 50 mcg/ml and higher inhibited the growth of the bacterium, temporarily delayed celular division, and induced intensive formation of elongated bacteroid-like cells, predominantly y-shaped or having a clavate shape. many bacteroid-like cells w ...1979502911
purification and characterization of agrocin 84.a procedure for the rapid purification of milligram quantities of agrocin 84, a bacteriocin-like compound produced by agrobacterium radiobacter strain k-84, has been developed. this procedure, which employs charcoal adsorption, ion-exchange, sieving chromatography, and continuous-flow electrophoresis, can yield agrocin 84 which is 65% pure on a dry weight basis. the purest preparations were strongly ultraviolet absorbing, with a maximum at 264 nm (epsilon 7.0/264 = 22,675 cm2 - m-1) and a minimu ...1979507786
effect of bacterial polysaccharides on the growth of gaeumannomyces graminis var. tritici and wheat roots.agrobacterium sp. and related species which in the soil and in the rhizosphere of wheat accompany the fungus gaemannomyces graminis var. tritici and cause take-all of the wheat roots produced polysaccharides in pure cultures (glucans, mannoglucans and galactomannoglucans). these polysaccharides were utilized better by the mycelium of g. graminis than glucose and polysaccharides of plant origin that occurred on the surface of wheat roots (the so-called mucigel). at lower concentrations these bact ...1979468081
comparative studies of polysaccharides elaborated by rhizobium, alceligenes, and agrobacterium. 1979519656
the involvement of the membrane potential in nitrogen fixation by bacteroids of rhizobium leguminosarum. 1979467678
adenine n6-substituent of agrocin 84 determines its bacteriocin-like specificity. 1979471050
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
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
effect of rj1rj1 (non-nodulating) soybeans on nodulation of near isogenic rj1rj1 plants in nutrient culture.an earlier proposal (can. j. microbiol. 7: 851; 1961) that rj1rj1 (non-nodulating) soybeans (glycine max (l.) merr.) excrete a substance that inhibits nodulation of rj1 rj1 (nodulating) plants was tested. using near isogenic lines (isolines) of "clark" and "harosoy" soybeans, we consistently found nonsignificant reduction in nodule number and acetylene reduction per rj1rj1 plant grown in association with their rj1rj1 counterparts: these results suggest that a nodulation inhibitor is not associat ...1977560904
effect of nitrite upon leghemoglobin and interaction with nitrogen fixation.nitrite (0.4 mm) added to soybean bacteroid preparations strongly inhibited c2h2 reduction. in the presence of leghemoglobin (0.1mm), a 3-fold enhancement of nitrogen fixation occurred but the inhibitory effect of nitrite was delayed. spectra of leghemoglobin showed a rapid disappearance of the 574 nm and 541 nm peaks of oxyleghemoglobin the presence of nitrite. concomitant oxidation of this hemoprotein gave ferric leghemoglobin as the single final product. high nitrite levels could depress nitr ...1977560873
ultrastructure of soybean nodules. ii: deterioration of the symbiosis in ineffective nodules. 1977560246
polypeptide synthesis by rhizobium bacteroids and bacteria.when rhizobium bacteroids (strain nzp 2257) from lupin nodules were isolated and incubated aerobically at high osmolarity, they incorporated [35s]-methionine into a characteristic set of polypeptides; many of these polypeptides coelectrophoresed on sds-polyacrylamide gels with the bacteroid polypeptide bands stained by coomassie blue. the labelled polypeptides were stable for several hours in pulse-chase experiments. changes in the concentration of h+, k+ and mg2+ in the incubation mixture affec ...1979497210
crown gall: economic importance and control.many plants of economic importance are possible hosts for agrobacterium tumefaciens, the causal organism of the crown gall tumor disease. damage has been reported on stone fruit (australia), vineyard (hungary, bulgaria), lettuce (brasil) ... in western-europe, crown gall seems to be of less economic importance for plants growing in the open air. however, plants cultivated in greenhouses have a greater chance to be tumorized, because of the more favourable circumstances for tumor induction. moder ...1979549390
effect of a bacteriophage on the colonisation and nodulation of clover roots by a strain of rhizobium trifolii.the presence of a virulent bacteriophage in the root zone of clover growing in seedling agar under controlled environments (14--17 and 19--23 degrees c) produced changes in the persistence and symbiotic effectiveness of a susceptible strain of rhizobium trifolii. the phage reduced the rhizoplane population of rhizobia and led to the appearance of variant substrains which were less susceptible to the bacteriophage and mostly ineffective in symbiotic nitrogen fixation. some were also changed in co ...1979540265
antineoplastic activity of derivatives of phosphoric acid. 1979549685
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
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
genetic control of symbiotic nitrogen fixation in soybeans. 1977562661
effect of a bacteriophage on colonisation and nodulation of clover roots by paired strains of rhizobium trifolii.the effect of a virulent bacteriophage on the competitive behaviour of paired strains of rhizobium trifolii in the root zone of clover plants was examined. the presence of bacteriophage reduced the population density of susceptible strains on the root surface and, in nodulation, favoured resistant or even partially resistant strains which were otherwise less able to form nodules. these effects occurred with different growth temperatures, host species, and ratios of strains in the inoculum.1979540266
properties of rhizobium trifolii isolates surviving exposure to specific bacteriophage.six strains of rhizobium trifolii were exposed to specific bacteriophages and the properties of 10 surviving clones of each studied. two temperate bacteriophages produced clones which were lysogenic but showed no changes in colony form, symbiotic properties, or somatic antigens. of forty clones selected by exposure to four other bacteriophages, none were lysogenic although there was some indication of unusually long association of phage with bacteria in infected cultures. seventeen of these clon ...1979540267
[nitrogen fixing activity of pea nodule bacteria during different phases of host plant development].the activity of nitrogenase in nodules of pea plants and the rate of diurnal nitrogen fixation were studied at different phases of the plant growth using the acetylene and isotope techniques. at the same time, the morphology of nodule bacteria was studied by electron and phase-contrast microscopy. about 90% of the bacteria in nodules were found in the form of bacteroids from the early phase of the plant growth (budding) to ripening when gemmated arthrospores could be observed on some bacteroids. ...1979470633
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
energy coupling efficiency of symbiotic nitrogen fixation. 1977562660
properties of the hydrogenase system in rhizobium japonicum bacteroids. 1978564190
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
sequence complexities of the poly(a)-containing mrna in uninfected soybean root and the nodule tissue developed due to the infection by rhizobium.in order to determine the number of structural genes expressed specifically in root nodules, the total complexities of poly(a) + polysomal rna populations from uninfected roots and mature nodules were compared. hybridization kinetics of nodule poly(a) + rna (nrna) to its cdna (ncdna) revealed a very abundant component comprising 18--20% of the nrna. this component was shown to be leghaemoglobin (lb) by the similarity of its kinetics of hybridization to that of purified lb-cdna. the hybridization ...1979572705
influence of soybean inoculation and nitrogen levels on populations and serogroups of rhizobium japonicum in ontario. 1979573169
efficiency of rhizobium japonicum strains as affecting nitrate reductase and dehydrogenase activities of the soybean nodules. 1978569408
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
preparation of a complementary dna for leghaemoglobin and direct demonstration that leghaemoglobin is encoded by the soybean genome.in soybean root nodules, leghaemoglobin (lb) accounts for 25--30% of the total soluble protein but is not detected in other tissues. in order to determine whether the lb genes are plant or bacterial in origin a cdna probe for lb was prepared from 9s poly (a) containing mrna of root nodules. although this 9s mrna directed synthesis of predominantly three forms of lb in vitro, the kinetics of hybridisation of cdna and the 9s mrna showed a transition at about 30% hybridisation which suggested that ...1978569292
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
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
vesicular-arbuscular mycorrhiza and nodulation in soybean.dual infections of glycine max with va endophytes and rhizobium, compared with rhizobium alone, increased the number and weight of nodules significantly in natural field soil and obviated the need of phosphate application for successful nodulation.1979574481
systems utilizing oxygenated leghemoglobin and myoglobin as sources of free dissolved o2 at low concentrations for experiments with bacteria. 1979573974
[preparation of a nitrogen-fixing association between rhizobium japonicum and soybean root callus]. 1979574185
[production of inoculates for leguminous plants. production of cellular suspensions of rhizobium (lotus group)].the influence of culture medium composition and operative conditions on the cellular growth of rhizobium sp (group lotus) strain is studied. as much as 1 x 10(9) cell/ml were obtained in 16 hours using sucrose in the medium as carbon source. the best growth rate was obtained (mu = o,22 h-1) when the experiments were performed at 400 r.p.m. and one volume of air/volume of medium x minute (oar = 793,0 ml of oxygen/1 h).1977594429
certain environmental factors affecting rhizobia and symbiotic systems.the interrelation between rhizobia and certain fungi, bacteria, actinomycetes, nematodes, and seed-coat diffusates of phaseolus vulgaris were investigated. the effect of pesticides, i.e. fungicides, herbicides, and nematocides on growth of rhizobia, and the symbiotic systems between rhizobia and their respective host is reported. degradation of certain herbicides and insecticides is shown. the movement of rhizobia in soil as affected by water tension, tolerance of salts, and soil temperatures ar ...1977576107
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
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 concerning the biology of rhizobia. 1. communication: serological investigations (author's transl)].according to earlier studies the strains of the rhizobia could be put into three biochemical groups (a, b, c) independently of the nodules of which kind of plants having been isolated from. the aim of our experiments has been the determination of the antigenic structure of these rhizobia strains. regarding the agglutination tests only 24 strains from the 47 ones were agglutinated by a sera, one b strain from the 3 b ones, and 2 c strains from the c ones gave positive reaction with b and c sera, ...1977602469
[transformation of l-tryptophan by rhizobium phaseoli].transformation of l-tryptophan was studied in rhizobium phaseoli 680. the culture was capable of oxidation decarboxylation, transamination and degradation of l-tryptophan. four metabolites were identified: tryptamine, indolyl-3-pyruvic, indolyl-3-acetic and anthranilic acids. the fifth metabolite has not been yet identified.1977600098
the effect of ammonium nitrate on the synthesis of nitrogenase and the concentration of leghemoglobin in pea root nodules induced by rhizobium leguminosarum.the effects of nh4no3 on the development of root nodules of pisum sativum after infection with rhizobium leguminosarum (strain pre) and on the nitrogenase activity of the bacteroids in the nodule tissue were studied. the addition of nh4no3 decreased the nitrogenase activity measured on intact nodules. this reduction of nitrogen fixation did not result from a reduced number of bacteroids or a decreased amount of bacteroid proteins per gram of nodule. the synthesis of nitrogenase, measured as the ...1978623788
trifolin: a rhizobium recognition protein from white clover.a protein agglutinin, trifoliin, was purified from white clover seeds and seedling roots. trifoliin specifically agglutinates the symbiont of clover, rhizobium trifolii, at concentrations as low as 0.2 microgram protein/ml, and binds to the surface of encapsulated r. trifolii 0403. this clover protein has a subunit with mr approximately 50 000, an isoelectric point of 7.3, and contains carbohydrate. antibody to purified trifoliin binds to the root hair region of 24-h-old clover seedlings, but do ...1978630002
inducing effect of plant cells on nitrogenase activity by spirillum and rhizobium in vitro.eleven different plant cell tissue cultures of both legume and non-legume origin have been grown in direct association, and in separate but close proximal association with both spirillum lipoferum and rhizobium sp. 32h1. basic similarities were found in the nutritional requirement for the induction of nitrogenase activity (c2h2) in both organisms. in the absence of plant cell cultures both organisms need to be provided with a pentose sugar and a tricarboxylic acid to induce high levels of nitrog ...1978647472
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
transformation of azotobacter vinelandii strains unable to fix nitrogen with rhizobium spp. dna.the phenotypes of azotobacter vinelandii atcc 12837 strains defective in nitrogen fixation (nif-) were characterized by intrageneric transformation with known nif- strains of a. vinelandii op. these former mutant strains were used as recipients for intergeneric transformation by deoxyribonucleic acid (dna) prepared from rhizobium spp. to determine if the rhizobia would transform the azotobacter nif- phenotypes to nif+. the frequency of nif+ transformants using rhizobium dna was always less than ...1978647476
[actinomycetes antagonistic to fungi and not affecting rhizobium meliloti].the effects of 481 actinomycetes isolated from agricultural soils supporting good growth of alfalfa or clover on two efficient strains of rhizobium meliloti a2 and s14 were studied. strain a2 was inhibited by 28% of the isolates and strain s14 was inhibited by 31% of them. no significant difference was found between the resistance of both actinomycete strains. the effects of the 288 isolates not affecting r. meliloti on six fungi were also studied. the most sensitive fungus was stemphylium sarci ...1978657008
purification and biochemical properties of complex flagella isolated from rhizobium lupini h13-3.1. the complex flagella of rhizobium lupini h13-3 differ from plain bacterial flagella in the fine structure of their filaments dominated by conspicuous helical bands, in their fragility and their resistance against heat decomposition. to elucidate the basis of these differences, the composition of complex filaments and their subunits was analysed. 2. isolated complex flagella containing the filament and hook protions were purified by differential centrifugation. hooks were separated by ultracen ...1978667114
nitrogenase--hydrogenase interrelationships in rhizobia.a review is given of the properties of the hydrogenase present in rhizobium bacteriods together with a discussion and evidence of the function of the enzyme in relationship to nitrogen fixation. the efficiency with which nodules fix nitrogen i.e. the amount of hydrogen evolved as a ratio of the total electron flow through nitrogenase, is considered and the recycling of hydrogen is discussed. attention is drawn to recent work, in which plants which have nodules containing hydrogenase have been sh ...1978667179
effects of interactions between different culture fractions of 'phosphobacteria' and rhizobium on mycorrhizal infection, growth, and nodulation of medicago sativa.interactions between cell-free culture supernatants, cells, and the whole cultures of rhizobium and phosphobacteria with endomycorrhizal fungi and their effects on growth and nutrition of medicago sativa grown in a low-phosphate soil were studied. a satisfactory nodulation was greatly dependent on the mycorrhizal symbiosis. cell-free supernatants of rhizobium and phosphobacteria improved plant growth, nodulation and mycorrhiza formation. the activity of phosphobacterial culture seemed to be due ...1978657005
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
influence of light on pectic enzymes in root exudates of trifolium alexandrinum inoculated with rhizobium trifolii.an in vitro experiment was conduced under bacteriologically controlled conditions to examine the effect of light on the production of pectin methyl esterase (pme) and pectin polygalacturonase (pg) in the root exudates of trifolium alexandrinum inoculated with an efficient strain of rhizobium trifolii. the results revealed that pme and pg increased with an increase in the duration of light to which plants were exposed. however, both the enzymes were detected in the root exudates of nonphotosynthe ...1978664934
membrane energization in relation with nitrogen fixation in azotobacter vinelandii and rhizobium leguminosarum bacteroids.nitrogen fixation in a. vinelandii and r. leguminosarum bacteroides shows identical characteristics with respect to the dependence on membrane energization, the sensitivity to uncouplers, the atp/adp-ratio, and the dependences on flavodoxinhydroquinone as electrondonor. although we have been successful in preparing inside-out vesicles which can be energized, attempts to couple these membranes to n2-ase were still unsuccessful. one of the major problems could be the failure to energize these vesi ...1978667180
[development of nodule bacteria in soil].the rate of growth of a population of nodule bacteria in soil and the time it takes for the cell generation depend on the content and accessibility of necessary nutrient substances. the periods of adaptation, active growth, and stabilization of the population number in the course of growth of a population are typical of soddy-podzolic continuous-cultivated soil. the duration of each period is determined by a sum of ecological factors.1978661644
intra- and intergeneric similarities of the rrna cistrons of agrobacterium and their significance for the taxonomy of this genus [proceedings]. 1978655694
regulation of nitrogen fixation in rhizobium spp. isolation of mutants of rhizobium trifolii which induce nitrogenase activity.this communication describes the isolation and characterization of mutants of rhizobium trifolii which can induce nitrogenase activity in defined liquid medium. two procedures were used for the isolation of these mutants from r. trifolii strain dt-6: (1) following chemical mutagenesis, slow growing mutants were selected which were unable to utilize nh+4 as sole source of nitrogen; (2) as spontaneous mutants resistant to the glutamate analogue l-methionine-dl-sulfoximine. mutants (dt-71, dt-125) ...1977588592
membranes in lupin root nodules. i. the role of golgi bodies in the biogenesis of infection threads and peribacteroid membranes.the process of infection of lupin nodule cells by rhizobia was examined using thin-section and freeze-fracture electron-microscopic techniques to characterize the properties of different membranes and to establish relationships between them. the membranes of the golgi bodies and the endoplasmic reticulum stained with zinc iodide-osmium tetroxide but not with phosphotungstic acid or silver. by contrast the infection thread membranes, peribacteroid membranes, plasma membranes and membranes of cyto ...1978649682
membranes in lupin root nodules. ii. preparation and properties of peribacteroid membranes and bacteroid envelope inner membranes from developing lupin nodules.peribacteroid membranes and bacteroid envelope inner membranes have been isolated from developing lupin nodules. isolation of the peribacteroid membranes was achieved by first preparing membrane-enclosed bacteroids free from other plant organelles or membranes. the peribacteroid membranes were then released by osmotic shock and purified by centrifugation to equilibrium on sucrose gradients. the bacteroids were broken in a pressure cell and the bacteroid envelope inner membranes were isolated usi ...1978649683
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
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
pectolytic enzymes in rhizobium.a sensitive pectin agar plate assay was used to demonstrate low levels of pectolytic enzymes in infective and noninfective strains of rhizobium. the possible relation of this characteristic to legume infection is discussed.1978623465
purification of rhizobium cytochromes p-450. 1978672626
fertility inhibition in rhizobium lupini by the resistance plasmid rp4.r plasmid rp4 inhibits the fertility of r. lupini. an rp4 carrying r. lupini donor strain is no longer capable of transferring chromosomal genes. after loss of rp4 the r. lupini fertility reappears. plasmid rp4 spontaneously mutates at high frequency in r. lupini. rp4 mutants which do not inbibit fertility were isolated. these mutants were always transfer-defective, too. it is postulated that the genetic information for fertility inhibition in r. lupini is a substantial part of the transfer unit ...1978672901
influence of ammonium chloride on the nitrogenase activity of nodulated pea plants (pisum sativum).a study was made on the short-term effect of ammonium ions on the nitrogenase activity of pea root nodules. nodulated pea plants (pisum sativum), having reached maximum acetylene-reducing activity, were supplied with nh4cl (20 mm). nitrogenase activity of intact plants, detached nodules, and isolated bacteroids was measured at differed time intervals. a significant drop (20 to 40%) in the acetylene-reducing activity of treated intact plants and their detached nodules was observed after 1 day. no ...1978677873
denitrification in rhizobium.thirty-three strains of rhizobium were examined for their reduction of nitrate under anoxic conditions. three patterns of dissimilatory nitrate reduction were observed: (1) reduction to n2o and n2 (denitrification), (2) reduction to and subsequent accumulation of no2- (nitrate respiration), (3) no reduction. strains of r. japonicum and the cowpea miscellany displayed all three types, while strains of r. leguminosarum, r. phaseoli, and r. trifolii did not reduce nitrate by dissimilatory means. th ...1978667742
surface carbohydrates of rhizobium. i. beta-1, 2-glucans.because of increased interest in surface carbohydrates of rhizobium in relation to host specificity, phenol-water extractions were carried out of whole cells of rhizobium strains of the species r. leguminosarum, r. phaseoli, r. trifolii and r. meliloti. fractionation of the crude extracts with cetavlon afforded polysaccharide mixtures, which were essentially free of rna and acidic exopolysaccharide (eps). they could be separated into a high molecular weight heteropolysaccharide fraction of lipop ...1979582886
differential stimulation and inhibition of growth of rhizobium trifolii strain t1 and other rhizobium species by various carbon sources.the physiological properties of rhizobium trifolii strain t1 were studied in detail, since this strain has many useful characteristics and appears ideal for development as a reference strain for r. trifolii. some tricarboxylic acid cycle intermediates and related compounds were found to stimulate growth in the presence of sucrose and arabinose, while others inhibited growth partially or completely. other r. trifolii strains behaved likewise. moreover, similar responses were also observed with ot ...1977617211
[demonstration of extrachromosomal dna in rhizobium meliloti].seven effective (nitrogen-fixing) strains of rhizobium meliloti have been studied. by sedimentation analysis of their alkaline lysates in alkaline sucrose gradients, a plasmid was found in four strains. in a strain (2011 str 3) which gave no result with this method, supercoiled dna was detected by cscl-dye buoyant density gradient centrifugation. that result was confirmed by analytical cs2so4-ag+ density gradients, which showed a heterogeneity in the average base composition of the dna extracted ...1978688104
survival and efficiency of cowpea rhizobia on pelleted and non-pelleted peanut seeds, treated with fungicides.peanut seeds were either normally inoculated with the legume inoculant okadin, containing cowpea rhizobia, or pelleted and treated with each of the fungicides brassical, thiram, orthocide 75, falisan, vitavax 75, and agrosan. the seeds were then incubated at room (+/- 25 degrees c) or refrigeration temperatures (+/- 5 degrees c). survival tests were made after 2 and 10 days. treated seeds were also planted in pots containing nile silt for testing the efficiency of rhizobia as affected by the fun ...1978696041
coordinated regulation of octopine degradation and conjugative transfer of ti plasmids in agrobacterium tumefaciens: evidence for a common regulatory gene and separate operons.by using the analog noroctopine, mutants of agrobacterium tumefaciens were isolated with altered regulation patterns for the ti plasmid-borne octopine utilization genes. these could be divided into three classes: (i) strains with a constitutive level of octopine enzymes and a high degree of spontaneous ti transfer; (ii) one strain with constitutive octopine enzymes but no spontaneous ti transfer; and (iii) strains with an altered inducibility in which, contrary to the wild-type ti plasmid, conju ...1978711678
tumor-inducing (ti) plasmids of agrobacterium share extensive regions of dna homology.labeled ti plasmid dnas from diverse agrobacterium strains were hybridized to southern blots of pti-b6-806 plasmid dna digest fragments of known map order. the map location of dna sequences common to all ti plasmids was found to be extensive, consistent with the view that ti plasmids have evolved from a common ancestral plasmid.1978721776
electron microscopic study of the rhizosphere in situ. 1978751698
adsorption of rhizobia to cereal roots. 1978718714
multiple genes coding for octopine-degrading enzymes in agrobacterium.most biotype 2 strains of agrobacterium tumefaciens and a. radiobacter which utilize nopaline also degrade octopine. in all such strains studied, the ability to degrade octopine did not appear to be transferred to plasmidless recipient cells under conditions of plasmid transfer in which the ability to utilize nopaline was transferred. an octopine-degrading mutant was isolated in a strain cured of its plasmid, suggesting that genes of octopine degradation may have a chromosomal location in some s ...1978721779
[competitive capacity of the nodular bacteria of lupine]. 1978723654
carotenoids of rhizobia. ii. the effect of nicotine on the carotenoid pattern of rhizobium lupini.with increasing concentrations in the growth medium of the cyclization inhibitors nicotine or 2-(4-chlorophenylthio)-triethylamine hydrochloride (cpta) the previously identified bicyclic carotenoids of rhizobium lupini (2,3,2',3'-tetrahydroxy-beta,beta-caroten-4-one and 2,3,2',3'-tetrahydroxy-beta,beta-carotene) were successively replaced by hitherto unknown monocyclic carotenoids. by application of mass and nuclear magnetic resonance spectroscopy 3 carotenoids were identified as 2,3-trans-dihyd ...1978718371
[nitrogenase activity of rhizobium meliloti and rhizobium vigna in a root tisse culture of leguminous and nonleguminous plants].as was shown using the acetylene technique, the nitrogenase activity of rhizobium meliloti and rhizobium vigna increased when they were cultivated with the root tissue cultures of legumes (lucerne, sweetclover) and non-legumes (tobacco, glasswort, carrot), particularly in the case of the former. the maximum activity of nitrogenase was found in r. meliloti. the tissue cultures of legumes had no effect on the growth of rhizobium whereas the tissues of non-legumes stimulated their biomass accumulat ...1978713878
studies on the mode of action of agrocin 84. 1978670092
nitrate reductase and dehydrogenase activities of cowpea nodules as affected by ammonium sulphate and urea fertilizers. 1978726712
the correlation between the efficiency of rhizobia and nitrate reductase and dehydrogenase activities of cowpea nodules.cowpea seeds variety fettriat were planted in nile silt soil and inoculated with 5 strains of cowpea rhizobia. after 50 and 80 days, the plants were uprooted, analysed for dry weight, total nitrogen, fresh weight of nodules, nitrate reductase activity in the leaves, and nitrate reductase and dehydrogenase activities in the nodule homogenate in the presence or absence of succinate, citrate, and ethyl alcohol. the data were analysed to establish the correlation coefficients between total nitrogen ...1978726713
[identification of actinomycetes with antifungal activity which do not affect rhizobium meliloti].thirteen isolates of actinomycetes that have broad antifungal activity and do not affect two efficient strains of rhizobium meliloti were identified as: nocardia autotrophica, streptomyces antimycoticus, s. anulatus, s. capoamus, s. lydicus, s. murinus, s. roseo-luteus, and s. thermotolerans.1978709436
nodule infection by bean yellow mosaic virus in phaseolus vulgaris.infection of root nodules of beans, phaseolus vulgaris l., by bean yellow mosaic virus (bymv) and the effect of the disease on the specific activity of the nodule are reported. infectivity and serological microprecipitin assays with two sources of bymv antiserum demonstrated that nodules from bean plants whose leaves had been inoculated with bymv contain bymv antigen. the disease reduced the fresh weights of tops, roots, and root nodules and induced premature nodule decay and/or nodule drop. the ...1978736539
trifluralin effect on pisum--rhizobium relationship.trifluralin inhibited root and shoot elongation of pisum sativum plant and caused isodiametric increase in cell volume of both tissues. the water content of the plant was not affected. the weedicide inhibited also growth and o2 uptake of rhizobium leguminosarum, isolated from pisum plant. reduction in the nitrogen content of pisum tissues was noticed, and this may be attributed to the inhibition of nodule formation. variations in the free and protein-amino acids were observed in the plant tissue ...1978726711
mutagenesis by insertion of the drug resistance transposon tn7 applied to the ti plasmid of agrobacterium tumefaciens. 1978748948
fingerprints of agrobacterium ti plasmids. 1978748949
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