Publications

transfer of rp4::mu plasmids to agrobacterium tumefaciens.		1978	372975
spontaneous formation of cointegrates of the oncogenic ti-plasmid and the wide-host-range p-plasmid rp4.		1978	372976
some aspects of fermentation of rhizobium leguminosarum with reference to economy of ingredients in the substrate.	incremental feeding of nutrients was found to be beneficial in mass cultivation of r. leguminosarum. similarly, semi-continuous fermentation of r. leguminosarum up to 4 days was also found to be useful in maintaining the viable number of cells.	1978	373307
electron microscopy and computerized evaluation of some partially denatured group p resistance plasmids.	dna of the r plasmids rp1, rp4 and rp8 was isolated from various hosts. the lengths of these plasmid molecules were determined by electron microscopy: rp1 and rp4 were about 19 micron long, rp8 measured 31 micron. an rp4 plasmid mutant, designated rp4a, was isolated from escherichai coli; it was about 1 micron shorter than normal rp4 dna. to investigate the molecular relationship between rp4, rp4a and rp8 dnas of these plasmids were partially denatured and examined in the electron microscope. me ...	1978	416173
[ethylmethane sulfonate induction of auxotrophic mutants of rhizobium meliloti and their characteristics].	ethylmethanesulfonate was used as a mutagen to induce auxotrophic mutants in rhizobium meliloti l5-30. survival of the culture depended on the period of time during which it was treated with the mutagen. thirteen auxotrophic mutants were isolated as a result of screening 1404 clones, and their requirements in growtn factors were determined. ethylmethanesulfonate induced mainly those mutants which required sulfur-containing amino acids. the activity of nitrogen fixation of the auxotrophic mutants ...	1978	212672
dna modifying enzymes of agrobacterium tumefaciens: effect of dna topoisomerase, restriction endonuclease, and unique dna endonuclease on plasmid and plant dna.	extracts from agrobacterium tumefaciens strain id135 contain three enzymes that have been characterized and partially purified. the first enzyme, a dna topoisomerase, appeared to relax only negatively twisted dna. the second enzyme, atu i, a type ii restriction endonuclease, generated the identical dna digestion pattern as ecorii when several dnas were used. the third enzyme, endonuclease a, showed a preference for superhelical dnas as substrates. when plasmid pck135dna, obtained from the virule ...	1978	212732
catabolite-repression-like phenomenon in rhizobium meliloti.	we report a phenomenon similar to catabolite repression in rhizobium meliloti. succinate, which allows the highest observed rate of growth of r. meliloti, caused an immediate reduction of beta-galactosidase activity when added to cells growing in lactose. a lac- mutant was unaltered in nodulation and nitrogen fixation capacities, but a pleiotropic mutant deficient in several catabolic properties was unable to produce effective nitrogen-fixing nodules.	1978	214420
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 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
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
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
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
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
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 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
mutant strains of rhizobium japonicum with increased ability to fix nitrogen for soybean.	a strain of rhizobium japonicum used in commercial inoculants was mutagenized and screened by a rapid effectiveness assay with soybean plants. two mutant strains nodulated the roots earlier than the wild type and also expressed greater symbiotic nitrogen-fixing activity than the wild type in the presence and absence of fixed nitrogen. in addition, one of the mutants formed more root nodules than the wild type. plants inoculated with these strains had increased dry weights ( approximately 60 perc ...	1978	17729899
soybean lines lacking the 120,000-dalton seed lectin.	seeds of 102 lines of glycine max (l.) merr., the soybean, were screened quantitatively for the presence of the 120,000-dalton soybean lectin. wide variation in the content of this lectin was noted, and five lines of soybean whose seed totally lacked the lectin were identified. roots of all five lines were effectively nodulated by several strains of rhizobium japonicum, thus indicating that the 120,000-dalton soybean seed lectin is probably not required for the initiation of soybean-rhizobium sy ...	1978	17738723
hydrogen reactions of nodulated leguminous plants: ii. effects on dry matter accumulation and nitrogen fixation.	the interaction between the atp-dependent evolution of h(2) catalyzed by nitrogenase and the oxidation of h(2) via a hydrogenase has been postulated to influence the efficiency of the n(2)-fixing process in nodulated legumes. a comparative study using soybean (glycine max l. merr.) cv. anoka inoculated with either rhizobium japonicum strain usda 31 or usda 110 and cowpea (vigna unguiculata l. walp.) cv. whippoorwill inoculated with rhizobium strain 176a27 or 176a28 cultured on a n-free medium wa ...	1978	16660301
hydrogen (h(2)) evolution by rhizobia after synergetic culture with soybean cell suspensions.	rhizobium japonicum cells were grown in liquid suspension cultures and separated from soybean plant cells by two to three bacterial membrane filters. under these conditions, the plant cells elaborated materials into the medium which aided in the expression of a major rhizobial phenotype, namely, nitrogenase activity (acetylene reduction). the evolution of h(2) was also measured and this activity relative to acetylene reduction, was influenced by: (a) o(2); (b) the quantity of conditioned plant m ...	1978	16660378
organic acid metabolism by isolated rhizobium japonicum bacteroids.	rhizobium japonicum bacteroids isolated from soybean (glycine max l.) nodules oxidized (14)c-labeled succinate, pyruvate, and acetate in a manner consistent with operation of the tricarboxylic acid cycle and a partial glyoxylate cycle. substrate carbon was incorporated into all major cellular components (cell wall + membrane, nucleic acids, and protein).	1978	16660386
interdependence of nitrogen nutrition and photosynthesis in pisum sativum l: i. effect of combined nitrogen on symbiotic nitrogen fixation and photosynthesis.	photosynthesis, primary productivity, n content, and n(2) fixation were determined as a function of applied nh(4) (+) in peas (pisum sativum l. cv. alaska) which were inoculated or not inoculated with rhizobium leguminosarum. cabon dioxide exchange rate (cer) increased 10-fold, total n content 7-fold, and total dry weight 3-fold in 26-day-old uninoculated plants as applied nh(4) (+) was increased from 0 to 16 millimolar. in inoculated plants of the same age cer and dry weight were maximal at 2 m ...	1978	16660450
interdependence of nitrogen nutrition and photosynthesis in pisum sativum l: ii. host plant response to nitrogen fixation by rhizobium strains.	physiological responses to infection by strains of rhizobium leguminosarum which differed in their capacity to reduce n(2) were determined in 26-day-old pea plants (pisum sativum l. cv. alaska) grown under uniform environmental conditions in the absence of combined n. the highest n(2) reduction rates, calculated from h(2) evolution and c(2)h(2)-dependent c(2)h(4) production measurements, were approximately 6-fold greater than the lowest. higher n(2) fixation rates were associated with greater co ...	1978	16660451
regulation by fixed nitrogen of host-symbiont recognition in the rhizobium-clover symbiosis.	either no(3) (-) (16 millimolar) or nh(4) (+) (1 millimolar) completely inhibited infection and nodulation of white clover seedlings (trifoliin repens) inoculated with rhizobium trifolii. the binding of r. trifolii to root hairs and the immunologically detectable levels of the plant lectin, trifoliin, on the root hair surface had parallel declining slopes as the concentration of either no(3) (-) or nh(4) (+) was increased in the rooting medium. this supports the role of trifoliin in binding r. t ...	1978	16660460
role of lectins in plant-microorganism interactions: iii. influence of rhizosphere/rhizoplane culture conditions on the soybean lectin-binding properties of rhizobia.	the influence of rhizosphere/rhizoplane culture conditions on the ability of various rhizobia to bind soybean seed lectin (sbl) was examined. eleven strains of the soybean symbiont, rhizobium japonicum, and six strains of various heterologous rhizobium species were cultured in root exudate of soybean (glycine max [l.] merr.) and in association with roots of soybean seedlings which were growing either hydroponically or in montmorillonite clay soil amendment (turface). all 11 of the r. japonicum s ...	1978	16660472
determination of hydrogenase in free-living cultures of rhizobium japonicum and energy efficiency of soybean nodules.	a sensitive tritium exchange assay was applied to the rhizobium system for measuring the expression of uptake hydrogenase in free-living cultures of rhizobium japonicum. hydrogenase was detected about 45 hours after inoculation of cultures maintained under microaerophilic conditions (about 0.1% o(2)). the tritium exchange assay was used to screen a variety of different strains of r. japonicum (including major production strains) with the findings that about 30% of the strains expressed hydrogena ...	1978	16660568
host-symbiont interactions: iii. purification and partial characterization of rhizobium lipopolysaccharides.	the lipopolysaccharides of three strains each of rhizobium leguminosarum, r. phaseoli, and trifolii have been purified and partially characterized. the last step in the purification procedure is gel filtration column chromatography using sepharose 4b with an elution buffer consisting of ethylenediaminetetraacetic acid and triethylamine. each of the lipopolysaccharides reported in this paper elutes as a symmetrical peak in the partially included volume of this sepharose 4b column. the ratio of 2- ...	1978	16660637
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
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
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
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
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
[production of soy bean inoculants. behavior of supports based on peat from tierra del fuego sterilized by vapor and ethylene oxide].	the survival of rhizobium japonicum was studied in neutralized and sterilized peats from ushuaia and rio grande. the carriers were sterilized by ethylene oxide and by autoclaving. similar counts for rhizobium (5 x 10(8) cel/g) were obtained in peat-cultures sterilized by both methods, after eight months. a good nodulation and nitrogen fixation capacity was observed with inoculated soybean plants. using the strain rhizobium japonicum e-45, no appreciable difference in symbiotic effectiveness was ...	1979	263653
nitrogenase activity in pure cultures of spectinomycin-resistant fast and slow-growing rhizobium.		1979	155455
thymidine incorporation into rhizobium meliloti.	thymidine is rapidly catabolized to thymine, beta-aminoisobutyric acid, and carbon dioxide by rhizobium meliloti cells. the incorporation of labelled thymidine into the dna of r. meliloti cells can be enhanced by the addition of low concentrations (10-20 micrograms/ml) of deoxyadenosine or other nucleosides (adenosine, uridine, guanosine). however, at high concentrations ( greater than 50 micrograms/ml) these compounds inhibit thymidine incorporation. conditions to obtain highly radioactive dna ...	1979	157797
changes in the nih guidelines for recombinant dna research (appendix 2: june-august, 1979).		1979	161243
differential toxicities of mercury to bacteria and bacteriophages in sea and in lake water.	mixtures of anionic hgcl3-/hgcl4(2)-complexes were less toxic to terrestrial bacteria (erwinia herbicola, agrobacterium tumefaciens), to marine bacteria (acinetobacter sp., aeromonas sp.), and to bacteriophages (phi 11 m 15 of staphylococcus aureus and p1 of escherichia coli) than were equivalent concentrations of hg as cationic hg2+. the toxicity of 1 ppm hg to a. tumefaciens. aeromonas sp., and phi 11 m 15 was less in seawater than in lake water. inasmuch as the hg-cl species are formed in env ...	1979	161510
polymyxin resistance in agrobacterium tumefaciens and its effect on crown gall tumor induction.	polymyxin-resistant (pblr) mutants of agrobacterium tumefaciens a6, b6, and b6m were isolated from polymyxin-sensitive (pbls) parent strains in a defined medium containing 600 microgram of polymyxin b sulfate per millilitre. the weight and number of tumors induced by pblr mutants on a variety of host plants such as carrot, potato, and pinto bean were 45--75% less than those induced by pbls wild types. the crude cell envelopes (cce) prepared from both pbls and pblr bacteria were inhibitory for tu ...	1979	219950
a c-terminal haem-bound cytochrome c-556 from agrobacterium tumefaciens, strain b-2a. amino acid composition and n-terminal sequence analysis.		1979	221262
regulation of hydrogen utilisation in rhizobium japonicum by cyclic amp.	utilisation (uptake) of hydrogen gas by whole cells of rhizobium japonicum was found to be influenced by the carbon source(s) present in the growth medium, with activity being highest in a medium containing sugars. tricarboxylic acid cycle intermediates, such as malate, significantly reduced h2 utilisation. no reduction in the hydrogenase activity is observed when the enzyme is assayed directly by the tritium exchange method, indicating that the decrease in hydrogen uptake activity is not due to ...	1979	222344
on the efficiency of oxidative phosphorylation in membrane vesicles of azotobacter vinelandii and of rhizobium leguminosarum bacteroids.		1979	223842
genetic engineering of symbiotic nitrogen fixation.		1979	227398
[metlegoglobin reductase from lupine nodules. purification and properties].	the purification procedure and properties of metlegoglobin reductase from the soluble fraction of lupine (lupinus luteus l.) nodules and from the proteins secreted by bacteroids rhizobium lupini in vitro are described. the properties of both forms of enzyme were found to be similar. a metlegoglobin reductase preparation purified 125-fold with a yield of 21% was obtained. the enzyme is strictly specific to the cofactor (nadh). no substrate specificity was revealed. the enzyme reduces oxidized cyt ...	1979	227483
iron-sulfur clusters in the molybdenum-iron protein component of nitrogenase. electron paramagnetic resonance of the carbon monoxide inhibited state.	carbon monoxide inhibits reduction of dinitrogen (n2) by purified nitrogenase from azotobacter vinelandii and clostridium pasteurianum in a noncompetitive manner (kii and kis = 1.4 x 10(-4) and 4.5 x 10(-4) and 7 x 10(-4) atm and 14 x 10(-4) atm for the two enzymes, respectively). the onset of inhibition is within the turnover time of the enzyme, and co does not affect the electron flux to the h2-evolving site. the kinetics of co inhibition of n2 reduction are simple, but co inhibition of acetyl ...	1979	228701
involvement of a plasmid in the hairy root disease of plants caused by agrobacterium rhizogenes.		1979	231271
rapid mapping of transposon insertion and deletion mutations in the large ti-plasmids of agrobacterium tumefaciens.	a procedure is presented, that has allowed the rapid assignment of transposon tn1 and tn7 insertion sites in the large (130 md) nopaline ti-plasmid ptic58, to specific restriction enzyme fragments. total bacterial dna is isolated from agrobacterium tumefaciens strain c58 mutants that carry a transposon in their ti-plasmid, and digested with an appropriate restriction endonuclease. the fragments are separated on an agarose gel, denatured and transferred to nitrocellulose filters. these are hybrid ...	1979	231764
agrobacterium ti plasmids as a tool for genetic engineering in plants.		1979	233066
small-scale techniques for the analysis of recombinant plasmids.	using the cloning of part of the t-dna of ptic58 from agrobacterium tumefaciens as an example, techniques are described which enable recombinant plasmids to be mapped and used as hybridization probes. in all cases the starting material is a colony of cells grown on an agar plate which is then subjected to lysis by lysozyme and triton x-100 in volumes of the order of 300 microliters thus eliminating the need for handling and centrifuging liquid cultures under restrictive containment conditions.	1979	233238
tumor induction by agrobacterium tumefaciens prevented in vigna sinensis seedlings systemically infected by ribonucleic acid viruses.	cowpea (vigna sinensis) seedlings failed to develop tumors after being inoculated with crown gall bacteria (agrobacterium tumefaciens) if, at times earlier than 1 day later, they were inoculated on the primary leaves with a cowpea mosaic virus that systemically infects them. inoculation with buffer or with a virus that is restricted to a localized infection, or to which the cowpea is immune, did not interfere with the subsequent development of tumors. the virus infection did not appear to affect ...	1979	422243
crown gall teratoma formation is plasmid and plant controlled.	experiments using different species of the plant nicotiana and strains of the bacterium agrobacterium tumefaciens showed that teratoma formation from crown galls was dependent on the combination of bacterial ti plasmid and host plant used.	1979	422509
regulation of hydrogenase in rhizobium japonicum.	factors that regulate the expression of an h2 uptake system in free-living cultures of rhizobium japonicum have been investigated. rapid rates of h2 uptake by r. japonicum were obtained by incubation of cell suspensions in a mg-phosphate buffer under a gas phase of 86.7% n2, 8.3% h2, 4.2% co2, and 0.8% o2. cultures incubated under conditions comparable with those above, with the exception that ar replaced h2, showed no hydrogenase activity. when h2 was removed after initiation of hydrogenase der ...	1979	422513
hydrogenase system in legume nodules: a mechanism of providing nitrogenase with energy and protection from oxygen damage.		1979	426786
fatty acid composition of rhizobium spp.	the fatty acid composition of 42 isolates belonging to the major plant affinity groups of rhizobium has been determined and found to vary reproducible with culture age. numerical taxonomic techniques applied to the 15 major fatty acid components of log-phase cultures of comparable physiological age showed that the rhizobia constitute a uniform group. however, two clusters comprising soybean-cowpea isolates and pea-bean isolates were evident. these observations, based on a simple analysis of only ...	1979	427657
[lysogeny of rhizobium japonicum and the sensitivity of these cultures to phages isolated from soil].	twenty cultures of rhizobium japonicum of various origin were tested for lysogeny using a cross technique with a preliminary uv induction and without it as well as by electron microscopy. none of the cultures was found in the lysogenic state. phages active against rh. japonicum were detected in four soil samples on which soybean plants were grown; 27 phages were isolated by the enrichment method and 3 phages without enrichment. the phages were capable of lysis of only rh. japonicum cultures and ...	1979	440166
[deformation of lucerne root hairs caused by the growth substances and culture broth filtrates of rhizobium meliloti].	deformation of lucerne root hairs caused by the action of beta-indolylacetic acid (iaa) and alpha-naphthylacetic acid (naa) differs from deformation induced by rhizobium meliloti. high concentrations of iaa brought about abnormal deformation of root hairs wherease the action of average concentrations of iaa resulted in corkscrew-like winding and wavy structures. no deformation was observed under the action of low iaa concentrations or the cultural broth of rhizobium. infective filaments in root ...	1979	440167
transcription in nuclei isolated from tobacco tissues.		1979	446760
development of the nitrogen-fixing and protein-synthesizing apparatus of bacteroids in pea root nodules.	some aspects of root nodule development of pisum sativum inoculated with rhizobium leguminosarum were examined. 1. nitrogenase activity (measured as acetylene reduction) appears to be preceded by leghemoglobin synthesis (measured immunologically). 2. syntheses of component i and component ii of nitrogenase are not strictly coordinated. synthesis of component i starts before component ii. 3. plant and bacteroid protein synthesis (measured by [35s]sulfate labeling) in root nodules declines rapidly ...	1979	454614
isolation of a non-tumor-inducing mutant of the ti plasmid of agrobacterium tumefaciens strain b6.	a nonpathogenic mutant of agrobacterium tumefaciens strain b6 was isolated and its properties compared with the parental strain in an effort to localize the mutation. both b6 and its mutant (b6-95) had similar colony color and morphology, were ketolactose positive, utilized octopine, and contained plasmid dna. kinetic analysis of dna reannealing showed that total dna homology and plasmid dna homology between b6 and b6-95 was at least 90%. the length of both plasmids was found to be 58 micrometer ...	1979	455147
phenotypic reversion of nitrogenase in pleiotropic mutants of rhizobium meliloti.	in two out of three pleiotropic mutants of rhizobium meliloti, defective in nitrate reductase induced by amino acid utilization in vegetative bacteria and in symbiotic nitrogen fixation, nitrogenase activity could be restored completely by purines and partially by the amino acids l-glutamate, l-aspartate, l-glutamine, and l-asparagine. the compounds restoring effectiveness in nitrogen fixation did not restore nitrate reductase activity in vegetative bacteria. the restoration of effectiveness sup ...	1979	455148
nitrogen fixation by rhizobium sp. 32h1. a morphological and ultrastructural comparison of asymbiotic and symbiotic nitrogen-fixing forms.	the induction of nitrogenase (c2h2) activity in asymbiotically cultured rhizobium sp. 32h1 was found to be associated with morphological changes in the cells which were more pronounced than those seen in bacteroids. polyphosphate granules were found in both bacteroids and cultured cells, but poly-beta-hydroxybutyrate vesicles were almost absent in bacteroids but were present in cultured cells. freeze-etching techniques revealed no differences between the asymbiotically cultured nitrogen-fixing f ...	1979	455150
genetic mapping of the bacteriophage ps8 of agrobacterium tumefaciens.	genetic mapping of the chromosome of the bacteriophage ps8 of agrobacterium tumefaciens using temperature sensitive (ts) mutants of the bacteriophage is described.	1979	456950
r-plasmid-mediated chromosomal gene transfer in agrobacterium tumefaciens.	although several techniques are available for transferring the ti plasmids from one strain of agrobacterium tumefaciens to another, there are no reproducible methods for analysis of chromosomal markers in this phytopathogen. the r plasmid, r68.45, is known to show chromosomal mobilizing ability in several bacterial genera including the closely related rhizobia. r68.45 was transferred into the prototrophic a. tumefaciens strain 15955. ten kanamycin-resistant transconjugant clones were tested for ...	1979	457601
general transduction in rhizobium meliloti by a thermosensitive mutant of bacteriophage df2.	a simiplified version of bacteriophage df2 transduction, using the thermosensitive mutant df2tsc, is described. the transduction frequencies of rhizobium meliloti markers by df1tsc are of about 10(-6) or higher. the development of transductants at 34 degrees c does not require the addition of antiserum for phage neutralization.	1979	457604
negative control of octopine degradation and transfer genes of octopine ti plasmids in agrobacterium tumefaciens.	the regulatory system that controls the expression of the ti plasmid-borne octopine degradation (uad) and transfer (tra) genes in agrobacterium tumefaciens was studied. a deletion mutant derived from the cointegrate plasmid r702::ti-b6s3 was isolated, which was compatible with a wild-type ti plasmid and which had retained the uad genes. by means of this mutant plasmid pal116, it was possible to make cells diploid for the uad genes. pal116 was introduced into rec- strains that contained different ...	1979	457610
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 ...	1979	457613
the involvement of the membrane potential in nitrogen fixation by bacteroids of rhizobium leguminosarum.		1979	467678