Publications

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
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
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, 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
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
[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
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
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
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
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
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
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
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
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 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
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
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
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
degradation of polysaccharides by oxidation and beta-elimination.		1978	26834
effect of oxygen tension on nitrogenase and on glutamine synthetases i and ii in rhizobium jaonicum 61a76.		1978	26344
glutamate synthase of rhizobium lupini bacteroids.		1978	25752
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
diversity of rhizobium leguminosarum in the palouse of eastern washington.	serology, antibiotic resistance, litmus milk reaction, and ability to fix nitrogen in peas were methods employed in studying the diversity of rhizobium leguminosarum. the two serogroups identified were related to the position on the soil slope where isolated were taken.	1978	16345331
persistence of rhizobium japonicum on the soybean seed coat under controlled temperature and humidity.	when rhizobium japonicum strain 61a68 was added to surface-sterilized soybean (glycine max) seed along with 12 different coating materials, a definite effect of temperature upon survival was observed both with and without coating materials. at a storage temperature of 15 degrees c and 50 +/- 5% relative humidity, from 0.9 to 14.1% of the original inoculum survived for 3 weeks. at 22.5 degrees c, from 0.5 to 7.2% of the original inoculum survived. at 30 degrees c, from 0.1 to 1.6% of the original ...	1978	16345264
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
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
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
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
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
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
expression of hydrogenase activity in free-living rhizobium japonicum.	a medium is described on which selected rhizobium japonicum strains express hydrogenase (h(2) uptake) activity under free-living conditions. low concentrations of carbon substrates, decreased oxygen tension, and the quantity of combined nitrogen in the medium were major factors influencing hydrogenase expression. hydrogenase activity was dependent upon a preincubation period in the presence of h(2) under conditions such that the cells did not exhibit nitrogenase activity. h(2) uptake rates were ...	1978	16592544
mutant strains of clover rhizobium (rhizobium trifolii) that form nodules on soybean (glycine max).	mutant strains of rhizobium trifolii that induce nitrogenase activity in the free-living state were isolated. these strains, unlike the wild type, nodulated soybean and mungbean plants, producing effective nodules. one of the strains, strain dt72, also nodulated clover but the nodules were ineffective. strain dt125 consumed hydrogen gas from the gas phase, which can be coupled to nitrogenase activity under appropriate conditions.	1978	16592529
further examination of presumptive rhizobium trifolii mutants that nodulate glycine max.	two recent reports described the isolation of derivatives of a rhizobium trifolii strain that had gained the ability to nodulate glycine max and vigna radiata and that had demonstrated altered patterns of carbon source utilization, free-living nitrogen fixation, and hydrogen uptake. more extensive characterization of these strains now supports the conclusion that these strains are r. japonicum and are not derived from the putative parent r. trifolii.	1979	16592695
effect of bentazon, a hill reaction inhibitor, on symbiotic nitrogen-fixing capability and apparent photosynthesis.	symbiotic associations of bean plants (phaseolus vulgaris l. cv. blue lake) and rhizobium phaseoli strain 127k17 were treated with the hill reaction inhibitor bentazon (3-isopropyl-1 h-2,1,3-benzothiadiazin-4-(3h)-one-2,2-dioxide). plants receiving foliar and root treatments of 1.8 kilograms per hectare bentazon were assayed at 6 hour intervals for n(2)-fixing capacity by measuring c(2)h(2)-dependent c(2)h(4) production and h(2) evolution and for co(2) exchange rates. in foliar treated plants gr ...	1979	16660682
in vitro binding of agrobacterium tumefaciens to plant cells from suspension culture.	in vitro binding experiments were carried out using (32)p-labeled cells of the virulent agrobacterium tumefaciens strain b6 and datura innoxia cells from suspension culture. binding kinetics showed that adherence of bacteria to datura cells increased gradually during the first 60 minutes and attained a maximum level within 120 minutes of incubation. maximum binding occurred at ph 6.0. the presence of ca(2+) and mg(2+) reduced binding slightly and edta had little effect at concentrations of 0.1 t ...	1979	16660732
dna content of free living rhizobia and bacteroids of various rhizobium-legume associations.	the dna content of bacteroids from 22 different rhizobium-legume associations was compared to that of the corresponding free living rhizobium species using laser flow microfluorometry. in all 18 effective associations, the bacteroids had either similar or higher dna content than the free living rhizobia. bacteroid populations isolated from effective clover (trifolium repens) and alfalfa (medicago sativa) nodules had an average dna content of >1.5-fold higher than free living r. trifolii and r. m ...	1979	16660736
environmental and genotypic effects on the respiration associated with symbiotic nitrogen fixation in peas.	estimated values for the respiration associated with symbiotic nitrogen fixation in pisum sativum l. were independent of irradiance, temperature, plant age, and co(2) concentration, despite large variation in the total rates of c(2)h(2) reduction and root + nodule respiration. similar values were also found in phaseolus vulgaris l., vicia faba l. and glycine max (l.) merr. among all combinations of four pisum cultivars with four rhizobium leguminosarum inoculants only the plant genotype signific ...	1979	16660833
economy of photosynthate use in nitrogen-fixing legume nodules: observations on two contrasting symbioses.	the economy of c use by root nodules was examined in two symbioses, vigna unguiculata (l.) walp. (cv. caloona):rhizobium cb756 and lupinus albus l. (cv. ultra):rhizobium wu425 over a 2-week period in early vegetative growth. plants were grown in minus n water culture with cuvettes attached to the nodulated zone of their primary roots for collection of evolved co(2) and h(2). increments in total plant n and in c and n of nodules, and c:n weight ratios of xylem and phloem exudates were studied by ...	1979	16661076
variation in nitrogenase and hydrogenase activity of alaska pea root nodules.	hydrogenase activity of root nodules in the symbiotic association between pisum sativum l. and rhizobium leguminosarum was determined by incubating unexcised nodules with tritiated h(2) and measuring tissue hto. hydrogenase activity saturated at 0.50 millimolar h(2) and was not inhibited by the presence of 0.10 atmosphere c(2)h(2), which prevented h(2) evolution from nitrogenase. total h(2) production from nitogenase was estimated as net h(2) evolution in air plus h(2) exchange in 0.10 atmospher ...	1979	16660819
inhibition of soybean cell growth by the adsorption of rhizobium japonicum.	soybean cells in suspension culture were inhibited in their growth by mixed culture with rhizobium japonicum 5033. rhizobium cells had the ability to adsorb on the surface of soybean cells. cell envelope prepared from rhizobium by sonic oscillation inhibited the growth of soybean cells. the growth-inhibiting activity of the cell envelope was depressed by beta-glucosidase, kio(4), urea, sodium cholate, and triton x-100, but was stable on heating at 120 c for 15 minutes. adsorption of the cell env ...	1979	16660916
a nodule-specific plant protein (nodulin-35) from soybean.	nodulin-35, a 35,000-molecular-weight protein, is present in soybean root nodules developed by different strains of rhizobium japonicum, irrespective of their effectiveness in fixing atmospheric nitrogen. this protein is not detected in uninfected plants and bacteroids or in free-living rhizobium and appears to be synthesized by the plant during the formation of root nodules.	1979	17750321
hydrogenase in rhizobium japonicum increases nitrogen fixation by nodulated soybeans.	some rhizobium strains synthesize a unidirectional hydrogenase system in legume nodule bacteroids; this system participates in the recycling of hydrogen that otherwise would be lost as a by-product of the nitrogen fixation process. soybeans inoculated with rhizobium japonicum strains that synthesized the hydrogenase system fixed significantly more nitrogen and produced greater yields than plants inoculated with strains lacking hydrogen-uptake capacity. rhizobium strains used as inocula for legum ...	1979	17841140
histological responses of four leguminous crops infected with meloidogyne incognita.	histological responses to meloidogyne incognita infection in rhizobium nodules of clover, horsebean, lupine, and pea were investigated. the formation of giant cells in vascular bundles of nodules and roots, and the basal connection of the nodule, were usually associated with abnormal xylem and/or deformed xylem strands. however, giant cells did not disturb or prevent the development of nodular tissues. areas in which galls formed, wall thickness of giant cells, and number of giant cells around t ...	1979	19300661
binding characteristics of n(2)-fixing bacteria to cereal roots.	the attachment of rhizobium japonicum 61a89 and rhizobium spp. 32h1 to the roots of wheat and rice seedlings is analyzed in terms of an equilibrium model. a langmuir adsorption isotherm describes the binding. strain 61a89 binds to a greater extent than does strain 32h1, and the equilibrium constants for each strain binding to wheat are strongly temperature dependent. both time-dependent dissociation and association, predicted by an equilibrium model, have been found. the dissociation rate consta ...	1979	16345433
hydrolytic enzyme production by rhizobium.	cellulase and hemicellulase activity was detected in temperate (infective and noninfective) and tropical strains (infective) of rhizobium. hydrolytic enzymes were initially detected by a cup-plate assay. the presence of cellulase and hemicellulase was confirmed by viscometric assay. implications of the presence of these enzymes in rhizobium are discussed.	1979	16345483
hydrogen evolution from alfalfa and clover nodules and hydrogen uptake by free-living rhizobium meliloti.	a series of rhizobium meliloti and rhizobium trifolii strains were used as inocula for alfalfa and clover, respectively, grown under bacteriologically controlled conditions. replicate samples of nodules formed by each strain were assayed for rates of h(2) evolution in air, rates of h(2) evolution under ar and o(2), and rates of c(2)h(2) reduction. nodules formed by all strains of r. meliloti and r. trifolii on their respective hosts lost at least 17% of the electron flow through nitrogenase as e ...	1979	16345361
colorimetric enzyme-linked immunosorbent assay for the identification of strains of rhizobium in culture and in the nodules of lentils.	an indirect enzyme-linked immunosorbent assay has been developed to identify strains of rhizobium in culture and in lentil nodules. the test can be used on cells from both fresh and frozen nodules obtained from plants grown either in a growth chamber or in the field. test results were confirmed by immunofluorescence. the enzyme-linked immunosorbent assay technique can be used for field studies and requires less antisera than other serological techniques.	1979	16345362
survival of rhizobium phaseoli in coal-based legume inoculants.	the long-term survival of rhizobium phaseoli strains 127k17, 127k26, and 127k35 in legume inoculants prepared with eight different coals (one strain and one coal per inoculant) was studied. the coals used were pennsylvania anthracite, bituminous coals from illinois, pennsylvania, and utah, lignite from north dakota and texas, and subbituminous coals from new mexico and wyoming; they ranged in ph from 4.7 to 7.5 all coals, with the exceptions of illinois bituminous coal and texas lignite (ph's of ...	1979	16345443
nondividing, bacteroid-like rhizobium trifolii: in vitro induction via nutrient enrichment.	rhizobium trifolii 0403 maintained in exponential phase via periodic dilution doubled in 210 min in mannitol-salts medium and doubled in 244 min in glycerolsalts. in both media, cell number and optical density increased in parallel. when exponentially growing cells in either medium were supplemented with a mixture of glucose, casamino acids, succinate, and yeast extract, optical density continued to increase but within less than the time required for one doubling, division ceased. the increase i ...	1979	16345481
polyacrylamide-entrapped rhizobium as an inoculant for legumes.	pot experiments showed that rhizobium japonicum cells entrapped in a polyacrylamide gel could be used as an inoculant for soybeans and compared favorably to laboratory-made peat base inoculant containing the same bacterial strain.	1979	16345370
population densities of rhizobium japonicum strain 123 estimated directly in soil and rhizospheres.	rhizobium japonicum serotype 123 was enumerated in soil and rhizospheres by fluorescent antibody techniques. counting efficiency was estimated to be about 30%. indigenous populations of strain 123 ranged from a few hundred to a few thousand per gram of field soil before planting. rhizosphere effects from field-grown soybean plants were modest, reaching a maximum of about 2 x 10 cells of strain 123 per g of inner rhizosphere soil in young (16-day-old) plants. comparably slight rhizosphere stimula ...	1979	16345383
modified fluorescent technique, using rhodamine, for studies of rhizobium japonicum-soybean symbiosis.	rhodamine-conjugated capsular polysaccharides isolated from rhizobium japonicum 61a76ns were used to examine binding between the labeled polysaccharides and soybean roots. fluorescein-labeled polysaccharides were not satisfactory because soybean root hairs autofluoresce in the fluorescein region.	1979	16345405
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
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
[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
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
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
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
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
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
nitrogenase activity in pure cultures of spectinomycin-resistant fast and slow-growing rhizobium.		1979	155455
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
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
sequence of the haem-binding region of cytochrome c-556 from agrobacterium tumefaciens, strain b2a [proceedings].		1979	93467
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
[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
on the efficiency of oxidative phosphorylation in membrane vesicles of azotobacter vinelandii and of rhizobium leguminosarum bacteroids.		1979	223842
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
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
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
agrobacterium ti plasmids as a tool for genetic engineering in plants.		1979	233066
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
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
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
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
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
autotrophic growth of h2-uptake-positive strains of rhizobium japonicum in an atmosphere supplied with hydrogen gas.	previous research from this laboratory has demonstrated co(2)-fixing and h(2)-uptake capacities of certain strains of rhizobium japonicum. in this report we have shown that sr, a h(2)-uptake-positive (hup(+)) strain of r. japonicum, is capable of autotrophic growth with h(2) as the energy source. growth occurred on mineral salts/vitamins/noble agar, mineral salts/vitamins liquid medium (0.27 mug of c as vitamins per ml), and in mineral salts liquid medium with no added vitamins when cultures wer ...	1979	287019
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
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
[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