| 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 ... | 1975 | 283 |
| seed pelleting with systemic insecticide (aldicarb) for the control of pests of mungo (phaseolus aureus l.). | | 1975 | 869 |
| properties of some bacteriocins produced by rhizobium trifolii. | bacteriocins produced by six strains of rhizobium trifolii were found to be of the relatively low molecular weight, non-phage type. the molecular weights ranged from approximately 1-8 x 105 to 2-0 x 105. all were of protein composition, as indicated by buoyant density (1-32 to 1-34 g/cm3) in csc1 and by sensitivity to proteolytic enzymes. they were resistant to rnaase but sensitive to dnaase. the six bacteriocins could further be separated into two subgroups on the basis of sensitivity to extrem ... | 1975 | 1463 |
| nitrogenase activity in cultured rhizobium sp. strain 32h1: nutritional and physical considerations. | nutritional and physical conditions affecting nitrogenase activity in the strain of "cowpea" rhizobia, 32h1, were examined using cultures grown on agar medium. arabinose in the basic medium (cs7) could be replaced by ribose, xylose, or glycerol, but mannitol, glucose, sucrose, or galactose only supported low nitrogenase (c2h2 reduction) activity. succinate could be replaced by pyruvate, fumarate, malate, or 2-oxoglutarate, but without any carboxylic acid, nitrogenase activity was low or undetect ... | 1976 | 5982 |
| 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 ... | 1976 | 8035 |
| 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 ... | 1976 | 8100 |
| isolation of covalently closed circular dna of high molecular weight from bacteria. | | 1976 | 11708 |
| nitrogen fixation in cultured cowpea rhizobia: inhibition and regulation of nitrogenase activity. | | 1976 | 11803 |
| the role of o2-limitation in control of nitrogenase in continuous cultures of rhizobrium sp. | | 1976 | 11804 |
| control of synbiotic nitrogen fixation in rhizobia. regulation of nh4+ assimilation. | this communication is concerned with physiological, biochemical, and genetic studies of the regulation of ammonium (nh4+) assimilation by rhizobia (root nodule bacteria) that infect leguminous plants. the major conclutions are (i) physiological studies show that rhizobia are able to assimilate nh4+ for growth only when supplemented with certain organic nitrogen sources (e.g., l-aspartate, l-leucine, l-serine). addition of as little as 2 mug/ml of l-aspartate supported growth on nh4+ as nitrogen ... | 1976 | 11819 |
| demonstration of different metabolic pathways starting with glucose or fructose in rhizobium meliloti. | rhizobium meliloti can produce many polysaccharides on d-fructose and d-mannitol. in glucose-grown cultures, few polysaccharides are observed and 2 keto-gluconate is accumulated. | 1976 | 11894 |
| purification and properties of an nadp+-specific isocitrate dehydrogenase from rhizobium meliloti. | an nadp+-specific isocitrate dehydrogenase has been purified and characterized from rhizobium meliloti. the enzyme showed mn++ or mg++ requirement. the apparent km values were 2.00 x 10(-5) m and 1.51 x 10(-5) m for dl-isocitrate and nadp+, respectively. the enzyme was inhibited by atp, to a lesser extent by adp and amp. alpha-ketoglutarate also inhibited the enzyme activity. oxalacetate and glyoxylate together inhibited the enzyme activity. the inhibition was competitive. studies with thiol inh ... | 1976 | 13706 |
| 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. | 1977 | 16867 |
| glutamine synthetase and control of nitrogen fixation in rhizobium. | | 1977 | 17073 |
| acclimation of rhizobium to salts, increasing temperature and acidity. | | 1977 | 18769 |
| the role of 6-phosphogluconate dehydrogenase in rhizobium. | a nicotinamide adenine dinucleotide (nad) linked 6-phosphogluconate (6-pg)dehydrogenase has been detected in rhizobium. the enzyme activity is similar in both slow- and fast-growing rhizobia. the nicotinamide adenine dinucleotide phosphate (nadp) dependent 6-pg dehydrogenase was detected only in the fast growers and was more than twice as active as the nad-linked enzyme. partial characterization of the products of 6-pg oxidation in rhizobium suggests that the nadp-linked enzyme is the decarboxyl ... | 1977 | 20218 |
| two forms of glutamine synthetase in free-living root-nodule bacteria. | | 1977 | 20885 |
| comparison of octopine, histopine, lysopine, and octopinic acid synthesizing activities in sunflower crown gall tissues. | | 1977 | 20891 |
| glutamine synthetase control of nitrogen fixation in rhizobia. | | 1977 | 21651 |
| adsorption of a phage tail-like bacteriocin to isolated lipopolysaccharide of rhizobium. | purified lipopolysaccharide (lps) from the bacteriocin sensitive strain rhizobium lupini i6-2 was shown to neutralize the killing activity of the bacteriocin. in the electron microscopical preparation the phage tail-like bacteriocin appears to be adsorbed to the lps; the tail sheath is contracted and the fibres are oriented towards the lps ribbon. in contrast, no interaction was observed between the bacteriocin and the lps of two resistant strains of rhizobium (16-2/ii and 16-3). the inactivatio ... | 1977 | 21942 |
| 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 ... | 1978 | 23179 |
| activity of nitrogenase and glutamine synthetase in relation to availability of oxygen in continuous cultures of a strain of cowpea rhizobium sp. supplied with excess ammonium. | in samples from nitrogen-fixing continuous cultures of strain cb756 of the cowpea type rhizobia (rhizobium sp.), newly fixed nh+4 is in equiblibrium with the medium, from where it is assimilated by the glutamine synthetase/glutamate synthase pathway. in samples from steady state cultures with different degrees of oxygen-limitation, nitrogenase activity was positively correlated with the biosynthetic of glutamine synthetase in cell free extracts. also, activities in biosynthetic assays were posit ... | 1978 | 23859 |
| effect of lime-pelleting on nodulation and yield of soybean grown in acid soil. | an experiment for studying the effect of lime-pelleting of inoculated seed of soybean glycine max. (l.) merr. on nodulation, growth, and grain yield was undertaken in red sandy loam of bangalore, having a ph of 4.0. the results indicated that inoculation alone increased significantly nodulation, plant dry weight, and grain yield. but inoculation plus lime-pelleting significantly increased the dry weight of nodules and plants, but not the grain yield. however, lime-pelleting was found to be benef ... | 1977 | 24961 |
| glutamate synthase of rhizobium lupini bacteroids. | | 1978 | 25752 |
| effect of oxygen tension on nitrogenase and on glutamine synthetases i and ii in rhizobium jaonicum 61a76. | | 1978 | 26344 |
| degradation of polysaccharides by oxidation and beta-elimination. | | 1978 | 26834 |
| control of ammonium assimilation in rhizobium 32h1. | the symbiotic, nitrogen-fixing bacterium rhizobium sp. 32h1 is a specialized ammonium producer during symbiosis. however, during free-living growth, rhizobium 32h1 assimilates ammonium very poorly. two pathways of ammonium assimilation exist in enteric bacteria. one is mediated by glutamate dehydrogenase, and the other is mediated by glutamine synthetase-glutamate synthase. the former pathway is altogether inoperative in rhizobium 32h1; the latter pathway operates at a slow rate and is under str ... | 1978 | 27498 |
| homologous and cross-reactive precipitins in anti-pneumococcal sera raised in mules. | serial bleedings were obtained from two mules during prolonged immunization, one with type xxv the other with type viii pneumococcal vaccine. igga, iggb, iggc, igb, igg(t) and igm present among purified pn anti-xxv and pn anti-viii immunoglobulin isolated from various bleedings were identified by use of rabbit anti-equine heavy chain specific reagents. radioimmunodiffusion with 14c-labelled type xxv pneumococcal capsular polysaccharide and horse and donkey reagents with species specificity direc ... | 1978 | 28285 |
| a rapid micro scale method for the detection of lysopine and nopaline dehydrogenase activities. | a rapid and sensitive method has been developed to determine lysopine dehydrogenase (ec 1.5.1-) and nopaline dehydrogenase activities in crown gall tumour tissues. by this method, enzyme activities as low as 0.2 micrometerol octopine or nopaline per h per g fresh weight tumour tissue can still be detected. in non-infected young pea seedlings, no lysopine dehydrogenase activity was detected. | 1978 | 31918 |
| agrobactin, a siderophore from agrobacterium tumefaciens. | a siderophore (microbial iron transport compound) was isolated from low iron cultures of agrobacterium tumefaciens b6. the substance was characterized as a threonyl peptide of spermidine acylated with 3 residues of 2,3-dihydroxybenzoic acid, the carbonyl group of 1 residue of the latter participating in an oxazoline ring with the beta-hydroxyl of the threonine moiety. the compound, n-[3-(2,3-dihydroxybenzamido)propyl]-n-[4-(2,3-dihydroxybenzamido)butyl]-2-(2,3-dihydroxyphenyl)-trans-5-methyl-oxa ... | 1979 | 33987 |
| a comparative study of different factors involved in mass cultivation of rhizobia, using shakers and fermentors. | growth was proportionally linear to increasing load of inoculum although an inoculum load of 6 to 8% was optimum to obtain uniform number of viable cells, beyond which the number of viable cells did not increase. from the point of view of contamination with other microorganisms and the nodulating ability of cultures, fermentor cultures were better than shake cultures. when growth of rhizobium was studied in relation to unit of mannitol consumed, it was observed that fermentors are more economica ... | 1978 | 34948 |
| the rhizobium--legume symbiosis. | the rhizobia are soil microorganisms that can interact with leguminous plants to form root nodules within which conditions are favourable for bacterial nitrogen fixation. legumes allow the development of very large rhizobial populations in the vicinity of their roots. infections and nodule formation require the specific recognition of host and rhizobium, probably mediated by plant lectins. penetration of the host by a compatible rhizobium species usually provokes host root cell division to form ... | 1979 | 36624 |
| interactions and dna transfer between agrobacterium tumefaciens, the ti-plasmid and the plant host. | agrobacterium tumefaciens is a gram-negative bacterium with the unique capacity to induce neoplasmic transformations in dicotyledonous plants. recently, both the mechanism and the biological significance of this transformation have been elucidated. agrobacterium tumefaciens strains contain a large extrachromosomal dna plasmid (the ti-plasmid). this ti-plasmid is responsible for the oncogenic properties of agrobacterium strains. a particular segment of the ti-plasmid, containing information deter ... | 1979 | 36626 |
| 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 ... | 1979 | 37237 |
| 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 ... | 1979 | 40601 |
| biosynthesis of ethylene from methionine. isolation of the putative intermediate 4-methylthio-2-oxobutanoate from culture fluids of bacteria and fungi. | methods are described for identifying the 2,4-dinitrophenylhydrazones of 4-methylthio-2-oxobutanoate by means of t.l.c., n.m.r. and mass spectroscopy. by using these methods 4-methylthio-2-oxobutanoate, a putative intermediate in the biosynthesis of ethylene from methionine, has been identified in culture fluids of aeromonas hydrophila b12e and a coryneform bacterium d7f grown in the presence of methionine. relative to 4-methylthio-2-oxobutanoate, the yield of 3-(methylthio)propanal (methional) ... | 1979 | 42392 |
| [effect of 2-ketogluconic acid synthesis on the exopolysaccharide production in a rhizobium meliloti strain]. | two categories of carbon substrates are defined for rhizobium meliloti: the first favours the synthesis of exopolysaccharides (fructose belongs to this category) while the other is not suitable (glucose belongs to this category). with fructose, resting cells synthesize polysaccharides during more than 100 h and this synthesis is at its best in aerobic conditions at 30 degrees c. with glucose, 2-ketogluconic acid accumulates and rapidly stops the synthesis. the method used to stop this acidificat ... | 1979 | 43767 |
| rhizobium lupini genetics. | | 1979 | 44239 |
| fine structure and distribution of extracellular polymer surrounding selected aerobic bacteria. | the structure and distribution of extracellular polymer surrounding bacillus circulans, diplococcus (streptococcus) pneumoniae, streptococcus salivarius, staphylococcus aureus, klebsiella pneumoniae, pseudomonas aeruginosa, herella vaginacola (acinetobacter calcoaceticus), and agrobacterium tumefaciens were studied by electron microscopy. a modified ruthenium red staining procedure was used to examine the fine structure of capsule and slime. freeze-etching and critical-point drying were used to ... | 1975 | 46774 |
| [proceedings: plasmids in rhizobium japonicum]. | | 1975 | 50812 |
| loss of agglutinating specificity in stock cultures of rhizobium meliloti. | several strains of rhizobium meliloti which have been subcultured for 23-33 years have changed from being markedly specific in their somatic agglutination reactions to become widely cross-reactive. on the other hand a fresh collection of the same species obtained from naturally nodulated, field-grown plants revealed the high degree of agglutinating specificity which had previously characterised the old cultures. attempts to reselect a specific substrain from old cross-agglutinating cultures by s ... | 1975 | 50826 |
| proceedings: studies on large dna plasmids of agrobacterium tumefaciens. | | 1975 | 54090 |
| cross-reactive antigens and lectin as determinants of symbiotic specificity in the rhizobium-clover association. | cross-reactive antigens of clover roots and rhizobium trifolii were detected on their cell surfaces by tube agglutination, immunofluorescent, and radioimmunoassay techniques. anti-clover root antiserum had a higher agglutinating titer with infective strains of r. trifolii than with noninfective strains. the root antiserum previously adsorbed with noninfective r. trifolii cells remained reactive only with infective cells, including infective revertants. when adsorbed with infective cells, the roo ... | 1975 | 55100 |
| 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 ... | 1976 | 56334 |
| influence of treflan, lindane, and ceresan on different parameters of symbiotic nitrogen fixation and yield in cicer arietinum. | | 1975 | 56828 |
| a general method for the isolation of non-sense suppressor strains in gram-negative bacteria. | | 1975 | 58594 |
| particulate cytochrome c in agrobacterium tumefaciens. | in agrobacterium tumefaciens the main part of c-type cytochromes is tightly bound to the bacterial cell envelope structures. several techniques were attempted to solubilize these cytochromes. the highest yield of cytochromes released is obtained by treatment of particle suspensions with 5% triton x-100. further purification confirms that the proteins are not really solubilized, but still aggregated in small heterogeneous complexes. chromatography on a cm-cellulose column demonstrates that at lea ... | 1975 | 58606 |
| purification of the agrobacterium radiobacter 84 agrocin. | | 1975 | 58630 |
| [a rna extract from oncogenic and non oncogenic strains of agrobacterium tumefaciens is an indispensable element for the induction of tumors in datura stramomium]. | an rna bound to the reverse transcriptase of agrobacterium tumefaciens has been isolated and shown to be oncogenic for stem tissues of datura stramonium grown under axenic conditions. the tumorous nature of the cellular change induced by the infectious rna was demonstrated by serial grafts of tumors on datura stems and by cultivation of tumorous tissue in vitro on a medium without supplemental auxins and cytokinins. active cellular proliferation within tissues of datura stems was a prerequisite ... | 1976 | 58705 |
| a phenomenon of photoenhancement of acridine orange-induced fluorescence. | it is a common experience that, with exposure to exciting radiation of the fluorescence microscope, the acridine orange-induced red fluorescence of the nucleus, produced by feulgen hydrolysis, fades with a concomitant shift to green. the present investigation reports a phenomenon of photoenhancement observed in the hydrolyzed cytoplasm where pale green fluorescence increases in intensity with exposure to exciting radiation. the phenomenon has been noticed in rhizobium, oscillatoria, tomato root ... | 1976 | 58929 |
| the effect of rhizobiophages on the effectiveness of rhizobium meliloti in symbiosis with lucerne. i. effect of various strains of r. meliloti and rhizobiophages on the yield and nitrogen fixation in lucerne. | pot and test-tube experiments were carried out on the effect of phages on yield and nitrogen fixation in lucerne inoculated with effective and non-effective strains of rhizobium meliloti. it was found that some strains of r. meliloti became activated by the phages, which was reflected in an increase in yield and in crude protein content in the plants, while others lost their effectiveness. the results of pot experiments were in line with those of the test-tube experiments and have demonstrated t ... | 1976 | 59525 |
| the effect of rhizobiophages on the effectiveness of rhizobium meliloti in symbiosis with lucerne. ii. effects of phages on the r. meliloti strains during passing them through the plant. | studies were carried out of the effectiveness of rhizobium meliloti strains reisolated from the roots of lucerne inoculated with effective and non-effective strains in the presence or absence of rhizobiophages. estimates were made of the changes in phage-sensitivity and lysogeny found in these strains compared with the parent strains. it was found that the character of the reisolated strains depended on the changes brought about by passing through the plant and on the activity of the phages. | 1976 | 59526 |
| the occurrence of rhizobiophages in various lucerne plantations. | | 1976 | 59531 |
| proceedings: l-sorbose metabolism in agrobacterium: a biochemical explanation for an intrageneric phenotypic difference. | | 1976 | 60964 |
| 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, ... | 1976 | 65064 |
| transfer of r1drd19 plasmid from escherichia coli j53 to rhizobium trifolii by conjugation. | rldrd19 plasmid was transferred by conjugation from escherichia coli j53 to rhizobium trifolii t24, t26 and 24xsm strains with frequency 10(-3) to 10(-5). the r. trifolii exconjugants carrying rldrd19 were in turn able to transfer the r factor by conjugation to other r. trifolii strains. rldrd19 was maintained stably in r. trifolii. r. trifolii 24xsm, t26 and 14m were also found to harbor an endogenous plasmid (molecular weight 5.5 megadaltons) with undetermined as yet properties. ridrd19 could ... | 1977 | 67758 |
| 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 ... | 1977 | 70252 |
| correlation between streptomycin resistance and symbiotic properties of rhizobium. i. conversion of spheroplastizing, effective r. trifolii strain b1 to avirulent rods with changed phage and antibiotic patterns after mutation to high level of streptomycin resistance. | rhizobium trifolii strain b1, which is infective and fixes nitrogen during symbiosis with clover plants, shows a peculiar property to undergo morphological change during growth, i.e. rods are changing into spheroplast-like forms. moreover, it failed to grow at 38 degrees. it was found that mutation to high level of streptomycin resistance (above 1000 microgram per/ml) caused loss of this property. further studies showed that simultaneously with the changes in streptomycin resistance other featur ... | 1977 | 70967 |
| [3h] dihydrostreptomycin accumulation and binding to ribosomes in rhizobium mutants with different levels of streptomycin resistance. | rhizobium trifolii b1, a symbiotic nitrogen fixer, is sensitive to streptomycin (10 microgram/ml) and spontaneously produces spheroplast-like forms during cultivation. streptomycin-resistant mutants selected with high doses of antibiotic (1,000 microgram/ml) showed pleiotropic changes, including loss of spheroplast formation and infectivity to plants, whereas mutants selected with low doses of streptomycin (10 to 100 microgram/ml) retained properties of parent strain b1 (i. zelazna-kowalska, act ... | 1977 | 72064 |
| auxotrophic mutations related to symbiotic properties of rhizobium meliloti strain l5-30. | mutants isolated from effective r. meliloti strain l5-30 which required histidine (his-240), arginine+uracil (arg-55) and cysteine (cys-243, cys-244 and cys-246) showed also loss of effectiveness. mutant requiring isoleucine+valine (ilv-74) was non-infective. relation of the metabolic deficiency to the symbiotic properties of these mutants was tested comparing symbiotic response of their prototrophic revertants and transductants. it was found that all revertants and transductants of the strain h ... | 1977 | 75662 |
| structure of nodules induced by auxotrophic and ineffective mutants of rhizobium meliloti strain l5-30 requiring cysteine, arginine+uracil and histidine. | nodules produced by ineffective mutants of r. meliloti strain l5-30 requiring arginine+uracil (arg-55) and cysteine requiring mutants (cys-243, cys-244, cys-246) studied under light microscopy were found to be occupied by bacteria. this indicates on defect in transformation of these mutants into n2 fixing bacteroids. these defects were not associated with auxotrophy. in the nodules induced by histidine requiring mutant (his-240) only few host plant cells were occupied by bacteria. this indicate ... | 1977 | 75663 |
| nitrogen fixation by rhizobium in pure cultures. | strains of rhizobium trifolii and rhizobium meliloti were tested for their asymbiotic nitrogen fixation ability. from among ten tested strains two r. trifolii and one r. meliloti expressed nitrogenase activity within the range of 1.3--9.3 nm c2h4/h/mg protein. asymbiotic nitrogen fixation was affected by the composition of the medium. | 1978 | 76425 |
| on the fate of exogenously supplied bacterial dna in soybean [proceedings]. | | 1977 | 79341 |
| genetic transformation in rhizobium trifolii. | markers controlling the synthesis of amino acids and organic bases as well as streptomycin resistance and sensitivity to acriflavine were transformed in rhizobium trifolii. the results indicate that the str marker was transformed independently of leu, his, ade and trp markers. co-transformation of leu and utra markers ranged from 3 to 7%, whereas that of thi and acr was 10%. | 1978 | 80930 |
| a dna region, common to all ti-plasmids, is essential for oncogenicity [proceedings]. | | 1978 | 81007 |
| a technique for mutagenesis by transposon insertion, applicable to most gram-negative bacteria [proceedings]. | | 1978 | 81013 |
| on the transfer and expression of bacterial plasmid dna in higher plants [proceedings]. | | 1978 | 84608 |
| genetic mapping of the chromosome of rhizobium trifolii. | cultures of the wild strain and auxotrophic mutants of rhizobium trifolii t37 synchronized by means of phenylethanol have been mutagenized with nitrosoguanidine. fifteen genetic markers were characterized in respect of their order and the time of replication based on the peaks of mutations of the genes. the time of r. trifolii chromosome replication was estimated using inhibitors of the initiation of dna replication: rifampicin, chloramphenicol and phenylethanol. the replicative map of r. trifol ... | 1978 | 86278 |
| restoration of effectiveness of r. meliloti ineffective mutants by transduction of high level streptomycin resistance. | rhizobium meliloti lysine dependent mutant, l5-30lys, was ineffective and this mutation was not cotransducible to lys. transduction of chloramphenicol and linked temperature sensitive mutations did not change its symbiotic properties. subsequent transduction of high level streptomycin resistance restored its effectiveness. streptomycin resistance marker was linked to chloramphenicol resistance and temperature sensitive markers. | 1978 | 86281 |
| bacterial polysaccharide which binds rhizobium trifolii to clover root hairs. | immunofluorescence, quantitative immunoprecipitation, and inhibition of bacterial agglutination and passive hemagglutination indicate that cross-reactive antigenic determinants are present on the surface of rhizobium trifolii and clover roots. these determinants are immunochemically unique to this rhizobium-legume cross-inoculation group. the multivalent lectin trifoliin and antibody to the clover root antigenic determinants bind competitively to two acidic heteropolysaccharides isolated from ca ... | 1979 | 86535 |
| bacteriocinogeny of rhizobium trifolii. | rhizobium trifolii strains differing in cell and colony morphology, streptomycin resistance, phage sensitivity pattern and infectivity to clover plants produced bacteriocins sensitive to proteases. elimination of bacteriocin production ability wtih sds and rifampicin treatment indicates that this feature is plasmid controlled. elimination of bacteriocinogenic plasmid did not influence other features of r. trifolii. | 1979 | 87113 |
| the effect of stra mutation on symbiotic nitrogen fixation by rhizobium meliloti. | studies on 3h-dihydrostreptomycin accumulation and binding to ribosomes showed that ineffective strain cmts17 carries strb type mutation changing its membrane permeability to the drug. introduction of high level streptomycin resistance of stra type into strain cmts17 was correlated with acquisition of effectiveness and membrane permeability to the drug. this suggests that changes in membrane permeability, responsible for ineffectiveness of strain cmts17, can be reversed by stra mutation. | 1979 | 87114 |
| strain-specific antigens in rhizobium leguminosarum. | fifty strains of rhizobium leguminosarum, isolated from five species of host plant (pisum sativum, p. arvense, vicia sativa, v. faba, and a lathyrus sp.) were examined for the presence of strain-specific somatic antigens by immune-diffusions against 13 antisera. thirty eight strains (76 per cent) were found to belong to the same sero-group and were serologically indistinguishable from each other, but four of these strains also exhibited non-reciprocal cross reactivity with other antisera. in con ... | 1979 | 89766 |
| transfer of rp4 and r68.45 factors to rhizobium. | two r factor were introduced by conjugation into rhizobium trifolii and rhizobium meliloti strains at a frequency of 10(-5) to 10(-6). plasmids rp4 from escherichia coli j53 and r68.45 from pseudomonas aeruginosa pao.25 were maintained stably in rhizobium hosts and could be retransferred to other rhizobium recipients. some of the transconjugants were able to mobilize chromosome and transfer his or met genes in intra-, and interspecies matings. | 1979 | 92171 |
| sequence of the haem-binding region of cytochrome c-556 from agrobacterium tumefaciens, strain b2a [proceedings]. | | 1979 | 93467 |
| occurrence and distribution of rhizobiophages in indian soils. | soil samples from 30 fields in neighbouring districts of varanasi were screened for rhizobiophages on 60 rhizobium strains. plaques were observed on five strains: p1, p5, su391 (r. leguminosarum), cb756 and 32h1 (rhizobium sp.). rhizobiophages infective on one or more of the five strains were present in all fields. there seems to be no correlation between presence of phage and the standing crop or the ph (7.1-8.2) of the soil. eight distinct rhizobiophages have been isolated and characterized fo ... | 1979 | 94751 |
| studies on regulatory functions of malic enzymes. v. comparative studies of malic enzymes in bacteria. | screening of four malic enzymes--nad-linked enzyme [ec 1.1.1.38], nad, nadp-linked enzyme [ec 1.1.1.39], nadp-linked enzyme [ec 1.1.1.40], and d-malic enzyme--was carried out with cell-free extracts of the following 16 strains of bacteria by the aid of sepharose 6b column chromatography: 9 strains of enteric bacteria, 3 strains of pseudomonas, alcaligenes faecalis, agrobacterium tumefaciens, rhodospirillum rubrum, and clostridium tetanomorphum. all the strains tested contained at least one malic ... | 1978 | 96110 |
| isolation of large bacterial plasmids and characterization of the p2 incompatibility group plasmids pmg1 and pmg5. | large plasmids from agrobacterium tumefaciens, salmonella typhimurium, escherichia coli, pseudomonas putida, and pseudomonas aeruginosa were routinely and consistently isolated using a procedure which does not require ultracentrifugation but includes steps designed to separate large-plasmid dna from the bacterial folded chromosome. it also selectively removes fragments of broken chromosome. a variety of large plasmids was readily visualized with agarose gel electorphoresis, including five betwee ... | 1978 | 97269 |
| tryptophan genes in rhizobium--their organization and their transfer to other bacterial genera. | r. leguminosarum trp alleles mapped by r68.45-mediated recombination were located in three distinct chromosomal regions. we isolated three derivatives of r68.45 that carried different trp genes of r. meliloti. each of the plasmids suppressed all of the r. leguminosarum trp alleles in a particular region. the r-primes were transferred to strains of p. aeruginosa carrying mutations in different trp genes. the plasmid paj24ji suppressed trpa, b and f mutants, paj73ji suppressed trpc and d and paj88 ... | 1978 | 105238 |
| separation of algal mixtures and bacterial mixtures with flow-microfluorometer using chlorophyll and ethidium bromide fluorescence. | the applicability of flow-microfluorometer to separate microbial cells was demonstrated with algal and bacterial cells. algal mixtures were sorted according to the natural chlorophyll fluorescence and the bacterial mixtures were sorted according to the fluorescence of ethidium bromide-stained nucleic acid. | 1979 | 109060 |
| increased synthesis of ribonucleotide reductase after deoxyribonucleic acid inhibition in various species of bacteria. | the specific activity of ribonucleotide reductase was found to increase significantly after deoxyribonucleic acid inhibition in seven species of bacteria investigated. this group of bacteria includes species with b12-dependent ribonucleotide reductase as well as some with an escherichia coli-type ribonucleotide reductase. | 1979 | 110794 |
| [stimulation of induction or inhibition of crown-gall tumor development by rna-fragments u2. interference by auxin]. | rna-fragments u2 obtained by mild degradation with rnase u2 of ribosomal rna containing a and g nucleotides in excess are capable of exhibiting either a stimulatory effect on the induction of crown-gall tumors or an inhibitory action on their subsequent development. these different effects are dependent on the moment at which rna-fragments were introduced into wounded pea seedlings infected by agrobacterium tumefaciens b6. the results obtained in vitro and in vivo suggest that an interaction bet ... | 1979 | 111819 |
| 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 ... | 1979 | 114109 |
| nitrogenase activity of rhizobium sp. strains in pure culture in relation to extracellular polysaccharide composition and antigenic affinity. | five strains of slow-growing rhizobium sp. (strains cb756, 32hi, cb562, cb627 and qa549) out of seventy examined developed appreciable nitrogenase activity in pure culture. cb756 and 32hi were serologically indistinguishable and each produced 6-deoxy-l-talose as a major component of its extracellular polysaccharide. they did not share these properties with cb562, cb627 or qa549. | 1978 | 117284 |
| construction and characterization of e. coli promoter-probe plasmid vectors. i. cloning of promoter-containing dna fragments. | derivatives of the escherichia coli drug-resistance plasmid pbr316 have been constructed which act as molecular probes for promoter-containing dna restriction fragments from various prokaryotic genomes. the plasmids, designated pbrh1 and pbrh3b, contain a unique ecori restriction site located within the promoter for the tetracycline resistance (tcr) gene. this site was created by the insertion of a chemically synthesized octanucleotide, containing the ecori cleavage sequence, into the hindiii si ... | 1979 | 118083 |
| some antigenic properties of cultured cell and bacteroid forms of fast- and slow-growing strains of lotus rhizobia. | immunodiffusion cross-reactions of 62 fast- and 76 slow-growing of lotus rhizobia with antisera to four of the fast-growing and five of the slow-growing strains were studied. no sharing of antigens by both fast- and slow-growing strains was found. somatic antigens were very strain specific with only eight of the fast-growing and five of the slow-growing strains tested having somatic antigens identical to those of one or more of the strains of the same group used for antisera production. in contr ... | 1979 | 119129 |
| 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 ... | 1979 | 119573 |
| re-examination of transformation within different species of rhizobium. | investigations of the phenomenon of transformation in rhizobium were carried out. streptomycin resistance (str) was the genetic marker used in all experiments, with the exception of auxotrophic strains. twenty-one experiments were performed on nine different rhizobium strains. some of these strains were previously reported to be transformed, while others had no prior history of transformation. different conditions which are thought to affect the development of competence were used. in these expe ... | 1979 | 121002 |
| growth yields, polysaccharide production and energy conservation in chemostat cultures of rhizobium trifolii. | rhizobium trifolii was grown in a defined medium in chemostat cultures. extracellular polysaccharide production was found in carbon-sufficient as well as in carbon-limited cultures. extracellular polysaccharide production in carbon-limited cultures was strongly dependent on the growth rate. in mannitol-limited cultures, asparagine was always totally depleted from the culture medium. only when the asparagine supply was not sufficient to meet the nitrogen need of the culture, ammonia assimilation ... | 1979 | 122050 |
| [symbiotic efficiency in spontaneous mutants of rhizobium legumino-sarum resistant to streptomyocin, spectinomycin, or kanamycin]. | symbiotic effectiveness of 45 mutant strains selected from four wild effective strains of rhizobium leguminosarum for resistance to streptomycin, spectinomycin or kanamycin was determined on vicia faba. loss of effectiveness occurred in twenty of these mutants; distribution of ineffective mutants was uniform among the three types of antibiotic resistant mutants but varied with the parent strain from which mutants have been derived. | 1975 | 125155 |
| carbohydrate catabolism of selected strains in the genus agrobacterium. | radiorespirometric and enzyme analyses were used to reveal the glucose-catabolizing mechanisms functioning in single strains of seven presumed agrobacterium species. the entner-doudoroff and pentose cycle pathways functioned in a. radiobacter, a. tumefaciens, a. rubi, and a. rhizogenes. whereas both catabolic pathways were utilized to an almost equal degree in the a. radiobacter and a. tumefaciens strains, use of the entner-doudoroff pathway predominated in the a. rubi and a. rhizogenes strains. ... | 1975 | 128316 |
| 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. | 1975 | 130001 |
| [nucleic acids during tumorous transformation in plants]. | crown-gall, one of the "plant cancer" is induced in the presence of a soil bacterium agrobacterium tumefaciens which elaborates a tumor inducing principle (t.i.p.), the nature of which is unknown. several informations suggest that some dna sequences of bacterial origin are included in tumorous cells of tissue cultures. a ribonuclease inhibits induction. an rna extracted from agrobacterium induces some hyperplasia transplantable by graft. | 1975 | 130189 |
| [tumorous nature of hyperplasia obtained experimentally]. | the determination of the tumorous nature of an overgrowth provides one of the most essential information for all research concerning animal and plant cancerisation. the experimental procedure which will be described here answers to this imperative: it allows to prove the tumorous characteristics of proliferations obtained by inoculation of agrobacterium tumefaciens rna fractions to datura stems. | 1975 | 130191 |
| [competing ability of rhizobium trifolii strains and efficiency of clover nitraginization on spent peat mosses]. | the competing ability of active strains of clover nodule bacteria was assayed in vegetation and field experiments. the competing ability of the industrial strains 311a and 347a was found to be sufficiently high. these strains increased the yield of clover on exhausted turf peats of the kirovsk region by 26--29%. the stimulating effect was observed also with new strains 313b and 329b. the optimal dose for inoculation of clover seeds in these conditions is 50,000 nodule bacteria per one seed. inoc ... | 1976 | 135915 |
| 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 ... | 1978 | 149461 |
| in vivo transfer of the ti-plasmid of agrobacterium tumefaciens to escherichia coli. | the ti-plasmids are naturally self-transmissible from their normal host agrobacterium to e. coli. they are however unable to stably establish themselves as a replicon in e. coli. it is nevertheless possible to study the ti-plasmids in e. coli with the help of ti::rp4 cointegrate plasmids that transfer and maintain themselves very efficiently in e. coli. an e. coli harbouring such a ti::rp4 plasmid is unable to catabolize octopine and unable to induce crown-gall tumours on plants. | 1978 | 150536 |
| isolation and characterization of the membrane envelope enclosing the bacteroids in soybean root nodules. | the membrane envelope enclosing the bacteroids in soybean root nodules is shown by ultrastructural and biochemical studies to be derived from, and to retain the characteristics of, the host cell plasma membrane. during the early stages of the infection process, which occurs through an invagination, rhizobium becomes surrounded by the host cell wall and plasma membrane, forming the infection thread. the cell wall of the infection thread is degraded by cellulolytic enzyme(s), leaving behind the en ... | 1978 | 151688 |
| 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 ... | 1978 | 154223 |
| nitrogenase activity in pure cultures of spectinomycin-resistant fast and slow-growing rhizobium. | | 1979 | 155455 |