| occurrence of l-lysine epsilon-dehydrogenase in agrobacterium tumefaciens. | a novel amino acid dehydrogenase catalyzing the oxidative deamination of the epsilon-amino group of l-lysine was found in the crude extract of agrobacterium tumefaciens icr 1660. the enzyme required nad(+) and was specific for l-lysine. the enzyme was optimally active at about ph 9.7. | 1982 | 6801024 |
| r68.45 mediated chromosomal gene transfer in agrobacterium tumefaciens. | a large plasmid enables its host agrobacterium tumefaciens to cause tumorous condition in a wide variety of dicotyledonous plants[see ooms et al. gene 14:33--50 (1981) )). the location and role of chromosomal genes in this phenomenon are not known. as the first stage in studying this aspect, a project was initiated to investigate the chromosomal genetics of the bacterium. r68.45, a p group plasmid, was chosen as a transmission agent. after a preliminary assessment it was decided to use c58 as a ... | 1982 | 6808964 |
| lytic effects of edta & lysozyme on virulent & avirulent strains of agrobacterium tumefaciens. | | 1982 | 6809600 |
| requirement for carbon dioxide for nonsymbiotic expression of rhizobium japonicum nitrogenase activity. | the expression and maintenance of nitrogenase (c(2)h(2)) activity in growing, microaerobic liquid cultures of rhizobium japonicum 3i1b110 was found to be stringently dependent on the sustained supply of co(2). this requirement for co(2) appeared to exceed the basal requirement for growth and was not related to effects on ph. | 1982 | 6811563 |
| enhancement of specific nitrogenase activity in azospirillum brasilense and klebsiella pneumoniae, inhibition in rhizobium japonicum under air by phenol. | specific nitrogenase activity in azospirillum brasilense atcc 29145 in surface cultures under air is enhanced from about 50 nmol c2h4 x mg protein -1 x h-1 to 400 nmol c2h4 by the addition of 1 mm phenol. 0.5 and 2 mm phenol added increase the rate 5-fold and 4-fold. this enhancement effect is observed only between 2 and 3 days after inoculation, with only a small reduction of the growth of the cells by the phenol added. in surface cultures under 1% o2, nitrogenase activity is slightly reduced b ... | 1982 | 6812526 |
| fate in model ecosystems of microbial species of potential use in genetic engineering. | the changes in populations of staphylococcus aureus, bacillus subtilis, salmonella typhimurium, klebsiella pneumoniae, agrobacterium tumefaciens, rhizobium meliloti, and saccharomyces cerevisiae were measured after their introduction into samples of sewage, lake water, and soil. enumeration of small populations was possible because the strains used were resistant to antibiotics in concentrations and combinations such that few species native to these ecosystems were able to grow on agar containin ... | 1982 | 6814361 |
| pleomorphism and acetylene-reducing activity of free-living rhizobia. | cowpea-type rhizobium sp. strain 32h1 and rhizobium japonicum usda 26 and 110 grown on a glutamate-mannitol-gluconate agar medium showed increases in the number of pleomorphic cells coincident with their acetylene-reducing activity. pleomorphs appeared to be inhibited in growth nonuniformly, because acetylene-reducing cultures were mixtures of rod, branched (v, y, and t), and other irregularly shaped cells. in contrast, strain usda 10 consistently failed to reduce acetylene, even though it also ... | 1983 | 6822472 |
| methylammonium uptake by rhizobium sp. strain 32h1. | we present evidence that methylammonium is transported into cowpea rhizobium sp. strain 32h1 cells by a membrane carrier whose natural substrate is ammonium. after growth in low (0.2%) oxygen, which is necessary for nitrogen fixation by these cells, respiring rhizobial cells took up [14c]methylammonium to high intracellular levels. cells grown in atmospheric (21%) oxygen did not take up methylammonium. uptake (transport plus metabolism) was maximal in cells harvested in the early stationary phas ... | 1983 | 6826521 |
| a soybean lectin having 4-o-methyl-d-glucuronic acid specificity. | evidence is presented for the presence of a new lectin activity in soybean seeds [glycine max (l.) merrill] that has specificity towards the 4-o-methyl-d-glucurono-l-rhamnan exopolysaccharide produced by certain strains of rhizobium japonicum. bacterial agglutination and precipitin reactions revealed the lectin activity in phosphate-buffered saline extracts of seeds of all cultivars tested, including the "lectinless" varieties. reaction of such extracts with carbohydrate haptens demonstrated tha ... | 1983 | 6838587 |
| genetic analysis of t-dna transcripts in nopaline crown galls. | plant crown gall tumor cells result from the insertion and expression of a defined dna sequence, called t-dna, which is derived from the ti plasmid, harbored by agrobacterium tumefaciens strains. to study the function of the genes of the t-dna of the nopaline ti plasmid, ptic58, a collection of mutants was isolated so that t-dna genes are inactivated either separately or in various combinations. it was found that no single t-dna gene or t-region border is absolutely essential for stable tumor fo ... | 1983 | 6839358 |
| protoporphyrin formation in rhizobium japonicum. | the obligately aerobic soybean root nodule bacterium rhizobium japonicum produces large amounts of heme (iron protoporphyrin) only under low oxygen tensions, such as exist in the symbiotic root nodule. aerobically incubated suspensions of both laboratory-cultured and symbiotic bacteria (bacteroids) metabolize delta-aminolevulinic acid to uroporphyrin, coproporphyrin, and protoporphyrin. under anaerobic conditions, suspensions of laboratory-cultured bacteria form greatly reduced amounts of protop ... | 1983 | 6841317 |
| plant tumors. | | 1983 | 6842759 |
| detection of antibacterial substances in some plant residues and their effect on certain micro-organisms. | the effect of dry residues from several plants, belonging to different families on certain microorganisms in vitro and in vivo, was studied. dry residues of paprica leaves, tomato tops, egg plant leaves, guava leaves, onion peels, garlic tops, wheat straw, sugar cane leaves, cotton leaves, egyptian clover tops, field bean tops or pea tops were examined for the presence of antibacterial substances, using successive extractions with hexane, ethyl ether, ethanol, and water, respectively, for each p ... | 1983 | 6845904 |
| stereochemistry of an alpha, beta-elimination reaction by d-glucosaminate dehydratase. | the proton nmr analysis of d-glucosaminate dehydratase reaction in d2o revealed the incorporation of a deuterium atom at c-3 carbon of the product, 2-keto-3-deoxy-d-gluconate. based on the chemical shift of c-3 proton of the product and the coupling constant characteristic for the c-3 and c-4 axial-axial coupling in the 2c5 pyranose conformation, the deuterium is in the pro-s position. thus, the dehydration of d-glucosaminate by the enzyme proceeds in a retention mode at c-3 carbon. kinetic para ... | 1983 | 6852253 |
| symbiotic properties of c4-dicarboxylic acid transport mutants of rhizobium leguminosarum. | the transport of succinate was studied in bacteroids of an effective, streptomycin-resistant strain (gf160) of rhizobium leguminosarum. high levels of succinate transport occurred, and the kinetics, specificity, and sensitivity to metabolic inhibitors were similar to those previously described for free-living cells. the symbiotic properties of two transposon (tn5)-mediated c4-dicarboxylate transport mutants (strains gf31 and gf252) were determined. strain gf31 formed ineffective nodules, and bac ... | 1983 | 6853448 |
| biosynthesis of amino acids from sucrose and krebs cycle metabolites by rhizobium lupini bacteroids. | the possibility of amino acids biosynthesis from sucrose, metabolites of krebs cycle or glyoxylate and ammonium by intact bacteroids has been studied. the suspension of intact rhizobium lupini bacteroids in phosphate buffer solution ph 7.8 was shown to catalyse the biosynthesis from sucrose and ammonium of some amino acids, such as alanine, aspartic and glutamic acids, glycine and serine. the yield of alanine and aspartic acid was 2.5-3 times higher than that of other amino acids, which were for ... | 1983 | 6855750 |
| a new opine derived from nopaline. | nopaline (n-[4-[(aminoiminomethyl)amino-]-1s-carboxybutyl]-2r-aminopentanedioic acid and isonopaline (n-[4-[(aminoiminomethyl)amino-1s-carboxybutyl]- 2s-aminopentanedioic acid) have been synthesized and separated by crystallization. in addition, a derivative of each of these compounds that forms spontaneously from the parent compounds under the usual crystallization conditions was isolated and characterized. the chemical properties, elemental analysis, 1h-nmr spectrum, and electrophoretic behavi ... | 1983 | 6863246 |
| [demonstration of a metabolic property of rhibozium meliloti usable for its classification]. | fast-growing rhizobium and agrobacterium strans were studied for their behaviour towards two carbohydrates (glucose and fructose) according to the following criteria: acidification and soluble exopolysaccharide production by resting cells. r. meliloti and agrobacterium spp. showed a similar behaviour: in glucose-containing medium, acidification occurred and few exopolysaccharides were produced, whereas in medium supplemented with fructose, a neutral ph was maintained and large amounts of exopoly ... | 1983 | 6870083 |
| involvement of cytochromes and a flavoprotein in hydrogen oxidation in rhizobium japonicum bacteroids. | electron transport components involved in h2 oxidation were studied in membranes from rhizobium japonicum bacteroids. hydrogen oxidation in membranes was inhibited by antimycin a and 2-n-heptyl-4-hydroxyquinoline-n-oxide with ki values of 39.4 and 5.6 microm, respectively. the inhibition of h2 uptake by cyanide was triphasic with ki values of 0.8, 9.9, and 93.6 microm. this result suggested that three cyanide-reactive components were involved in h2 oxidation. h2-reduced minus o2-oxidized absorpt ... | 1983 | 6874637 |
| nif- hup- mutants of rhizobium japonicum. | two h2 uptake-negative (hup-) rhizobium japonicum mutants were obtained that also lacked symbiotic n2 fixation (acetylene reduction) activity. one of the mutants formed green nodules and was deficient in heme. hydrogen oxidation activity in this mutant could be restored by the addition of heme plus atp to crude extracts. bacteroid extracts from the other mutant strain lacked hydrogenase activity and activity for both of the nitrogenase component proteins. hup+ revertants of the mutant strains re ... | 1983 | 6874648 |
| structure of t-dna in roots transformed by agrobacterium rhizogenes. | dna isolated from hairy roots incited on daucus carota by agrobacterium strains harboring the ri plasmid was probed with ri plasmid fragments to identify plasmid sequences transferred and integrated into the plant genome. one hairy root line was incited by an a. rhizogenes natural isolate strain harboring two large plasmids in addition to the ri plasmid. dna from hairy roots incited by this strain contained a total of five nonidentical copies of t-dna which together comprised a t-dna complement ... | 1983 | 6875427 |
| [induced resistance to kanamycin and tetracycline in rhizobium japonicum]. | spontaneous mutants km-r and tc-r of r. japonicum with various levels of resistance to kanamycin (0.8-20 mg/ml) and tetracycline (130-210 micrograms/ml) were isolated. no cross resistance in the mutants was observed. plasmid r68.45 transferred to the wild strains resistance to 210 micrograms/ml of tetracycline and to 20 mg/ml of kanamycin. this plasmid did not practically increase the resistance to tetracycline in mutants tc-r. at the same time it markedly increased the resistance to kanamycin i ... | 1983 | 6881945 |
| morphology of root nodules and nodule-like structures formed by rhizobium and agrobacterium strains containing a rhizobium meliloti megaplasmid. | we examined expression of the megaplasmid prme41b of rhizobium meliloti in two different rhizobium sp. strains and in agrobacterium tumefaciens. transfer of prme41b into these bacteria was facilitated by insertion of a recombinant plasmid coding for mobilization functions of rp4 into the nif region (kondorosi, a., e. kondorosi, c.e. pankhurst, w. j. broughton, and z. banfalvi, 1982, mol. gen. genet., 188:433-439). in all cases, transconjugants formed nodule-like structures on the roots of medica ... | 1983 | 6885919 |
| 3-o-methyl-l-rhamnose from a rhizobium capsular polysaccharide. | | 1980 | 6893167 |
| isolation of cofactor common to molybdenum-containing enzymes: nitrate reductase from lupine bacteroids and xanthine oxidase from milk. | a quantitative method for the anaerobic isolation of a molybdenum cofactor from two molybdenum-containing enzymes, nitrate reductase from the bacteroids of lupine nodules and xanthine oxidase from milk, is described. it was established that the cofactor consists of an aromatic component and a number of amino acid residues bound to it. the structural and catalytic function of the molybdenum cofactor in the enzyme was established. | 1980 | 6895606 |
| short-term effect of ammonium chloride on nitrogen fixation by azotobacter vinelandii and by bacteroids of rhizobium leguminosarum. | | 1980 | 6928406 |
| foreign dna sequences in crown gall teratomas and their fate during the loss of the tumorous traits. | | 1980 | 6929944 |
| the effect of waterlogging on the synthesis of the nitrogenase components in bacteroids of rhizobium leguminosarum in root nodules of pisum sativum. | | 1980 | 6930267 |
| generalized transduction in rhizobium meliloti. | the phage 11 of r. meliloti performs generalized transduction. this was confirmed by the variety of single markers transferred and by separating transducing particles containing budr-labelled bacterial dna. the transduction frequencies depended on the marker. linked alleles were mapped by cotransduction on fragments of bacterial dna equal in size to the phage dna. with crosses between antibiotic resistancy and auxotrophic markers a partial map was constructed with str, cml, pur-19, and leu-44 si ... | 1980 | 6930536 |
| screening for mutants of rhizobium japonicum with defects in nitrogen fixing ability. | mutants of rhizobium japonicum with reduced ex planta nitrogenase activity could be isolated with high frequency by direct screening of ultra-violet mutagenized bacteria growing as spots on the surface of an appropriate agar medium permitting derepression of nitrogenase synthesis. small glass chambers fitted with a serum cap were pushed into the agar around each spot of growth, forming a small enclosed gas space which was made to 10% acetylene, permitting assessment of nitrogenase activity by th ... | 1980 | 6934662 |
| plasmid dna of agrobacterium tumefaciens detected in a presumed habituated tobacco cell line. | 'tabac anergié' tissue has been used by many investigators as a habituated tobacco cell line. in this study, we have found sequences which are homologous to approximately 9 megadaltons of an agrobacterium octopine-type plasmid in dna isolated from 'tabac anergié' tissue. these t-dna sequences were shown to be the same 'core dna' sequences found to be present in several other unorganized tumor lines which have been studied in our laboratory. the t-dna was also shown to be integrated into plant dn ... | 1980 | 6935494 |
| turnover of nitrogenase and leghemoglobin in root nodules of pisum sativum. | turnover rates of the two nitrogenase components and leghemoglobin in root nodules of pea plants nodulated with rhizobium leguminosarum were determined with three different methods: 1, kinetics of 35s incorporation into protein; 2, pulse-chase experiments; 3, chloramphenicol inhibition of bacteroid protein synthesis. methods 1 and 3 revealed that the turnover rates of the two nitrogenase components and leghemoglobin are identical to the average rate of bacteroid and plant nodule protein turnover ... | 1980 | 6938244 |
| effect of nh4+ on nitrogenase activity in nodule breis and bacteroides from pisum sativum l. | nodule breis and bacteroid preparations were made from pisum sativum l. (cv. trapper) inoculated with a single strain of rhizobium leguminosarum. the detached nodules were triturated under helium flow. the resultant breis could support c2h2 reduction in n-tris[hydroxymethyl]methyl-2-aminoethane-sulfonic acid buffer (tes) without any additions for over an hour. nh4+ was found to inhibit c2h2 reduction and h2 evolution. the inhibition was not dependent on the counterion and was evident immediately ... | 1981 | 6938248 |
| potential effects of thiram on medicago - r. meliloti symbiotic association. | the effects of thiram and 2 commercial thiram formulations on the growth and respiration of rhizobia were tested to compare the extent of bacteriostasis under controlled conditions. although bacteriostasis was measurable at all concentrations tested, liquid cultures grew to maximum optical density in thiram suspensions containing less than 10 micrograms/ml. percentage germination, root elongation, and subsequent nodulation by r. meliloti of 2 cultivars of alfalfa, were determined in thiram suspe ... | 1981 | 6942046 |
| the crown-gall potato disk bioassay as a primary screen for compounds with antitumor activity. | a variety of samples consisting of purified compounds (of various origins) and ethanol extracts from plants were assayed for their activity on the growth and initiation of crown-gall tumors on potato disks. the results demonstrated a high correlation between the ability of these compounds to inhibit the initiation and growth of crown-gall tumors on potato disks and their corresponding activity on the mouse p388 leukemia protocol. of the 21 compounds tested to date, there were two false-positives ... | 1981 | 6944538 |
| nuclear and polysomal transcripts of t-dna in octopine crown gall suspension and callus cultures. | to establish a detailed map of the transcribed parts of the t-dna in two octopine crown gall lines grown in suspension culture, t-dna-derived steady-state nuclear and polysomal rna as well as rna synthesized in isolated nuclei purified from the crown gall tissues, was analyzed by southern blot hybridization to specific fragments of the t-region of the octopine plasmid pti ach5. in addition total rna isolated from the same lines grown as callus tissue on solid agar, was analyzed for t-dna specifi ... | 1981 | 6945473 |
| use of plasmid r68.45 for constructing a circular linkage map of the rhizobium trifolii chromosome. | plasmid r68.45 was used to promote conjugal transfer of chromosomal markers in rhizobium trifolii rs55. analysis of two-factor and three-factor crosses among r. trifolii strains enabled construction of a circular linkage map of the r. trifolii chromosome, containing 17 nutritional and resistance markers. | 1982 | 6947977 |
| mendelian transmission of genes introduced into plants by the ti plasmids of agrobacterium tumefaciens. | insertion of the bacterial transposon tn7 was used to obtain mutants of an octopine ti plasmid. crown gall tumours induced on tobacco by an agrobacterium tumefaciens strain carrying a particular mutant ti plasmid (pgv2100) were found to give rise to shoots. these shoots were grown in vitro and one of them (rgv-1) was found to contain the t-dna specific enzyme lysopine dehydrogenase (lpdh) and to form roots. after transfer to soil, rgv-1 developed into a morphologically and functionally normal to ... | 1981 | 6948997 |
| location of nodulation and nitrogen fixation genes on a high molecular weight plasmid of r. meliloti. | r. meliloti strain 41 (rm41) was shown to harbour two indigenous plasmids with molecular weights of 140 mdal (prme41a) and more than 300 mdal (prme41b), respectively. using a heat-treatment procedure, derivatives of rm41 defective in nodulation (nod-) or nitrogen fixation (fix-) have been readily obtained. in some nod- mutants the deletion of a segment of plasmid prme41b was found. based on the demonstrated homology between the nitrogen fixation (nif) genes of klebsiella pneumoniae and of r. mel ... | 1981 | 6949000 |
| genes controlling early and late functions in symbiosis are located on a megaplasmid in rhizobium meliloti. | large plasmids of molecular weight varying from 90 to around 200 x 10(6) have earlier been detected in most rhizobium meliloti strains using an alkaline denaturation - phenol extraction procedure. with a less destructive method (eckardt 1978) it was possible additionally to detect one plasmid of molecular weight clearly greater than 300 x 10(6) (= megaplasmid) in all of twenty-seven r. meliloti strains of various geographical origins and nodulation groupings investigated. four strains (rcr 2011, ... | 1981 | 6949001 |
| root exudates in relation to growth and nitrogenase activity of rhizobium japonicum. | root exudates of cowpea and soybean were collected in aerated water cultures. the ability of these exudates to support nitrogenase activity of r. japonicum was studied on defined media. when a complete nitrogenase-inducing medium was supplemented with concentrated root exudate, there was an increased nitrogenase activity. when the cowpea root exudate was substituted for glutamine or sodium succinate in the medium, nitrogenase activity was not detected. growth was good when the root exudate was s ... | 1981 | 6949404 |
| induction of nitrogenase in moong bean rhizobium under cultural conditions. | | 1981 | 6951806 |
| site-specific insertion of genes into t-dna of the agrobacterium tumor-inducing plasmid: an approach to genetic engineering of higher plant cells. | this paper presents a method for insertion of genetic material into a specific site in t-dna, the portion of agrobacterium tumor-inducing (ti) plasmid that becomes incorporated into the nuclear dna of transformed plant cells when crown gall tumors are incited by this plant pathogen. the three stages of our procedure are as follows: 1. a t-dna subfragment cloned in pbr322 is cleaved by a restriction endonuclease at a unique central site and target dna (a kanamycin resistance marker) is ligated in ... | 1981 | 6955419 |
| rhizobium japonicum mutants defective in symbiotic nitrogen fixation. | rhizobium japonicum strains 3i1b110 and 61a76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. the proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. all of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wil ... | 1982 | 6956566 |
| indoleacetic acid complementation and its relation to host range specifying genes on the ti plasmid of agrobacterium tumefaciens. | host range variations were noted when 23 wild-type strains of agrobacterium tumefaciens were tested on 27 different plant species. because we have shown previously that host range specificity is conferred by the pti plasmid, these variations in host specificity implicated genetic differences among pti plasmids within the a. tumefaciens population that was tested. host specificity was independent of the type of opine utilized and biotype of the strain used. these data suggested that separate gene ... | 1982 | 6962315 |
| em5400, a family of monobactam antibiotics produced by agrobacterium radiobacter. i. taxonomy, fermentation and biological properties. | | 1982 | 6978878 |
| isolation and characterization of an r-prime plasmid from rhizobium meliloti. | using a simple enrichment procedure, we isolated an r-prime derivative of plasmid r68.45 carrying a 17.8-megadalton segment of the rhizobium meliloti 41 chromosome. the chromosomal segment carried on this plasmid (pgy1) includes the markers cys-24+, cys-46+, and att16-3. plasmid pgy1 mobilized the chromosome in a polarized way starting from the region of homology, but cannot promote chromosome transfer from other sites. the att16-3 site on pgy1 allowed the integration of phage 16-3 into pgy1, an ... | 1980 | 6986354 |
| interspecies homology of nitrogenase genes. | cloned nitrogen fixation (nif) genes from klebsiella pneumoniae hybridize to dna from 19 out of 19 widely divergent nitrogen-fixing bacterial strains but do not hybridize to dna from 10 different non-nitrogen-fixing species. k. pneumoniae nif dna fragments that hybridize to dna from other species contain part of the three structural genes that code for nitrogenase polypeptides. we have utilized this homology to clone an ecori restriction endonuclease fragment from rhizobium meliloti that hybridi ... | 1980 | 6987649 |
| autotransmissible resident plasmid of rhizobium meliloti. | a resident plasmid of wild-type strains of rhizobium meliloti of 59.6 megadaltons has been shown to be transferred at a high frequency to "cured" strains of this bacterial species. this plasmid, named pez1, that confers phage-sensitivity to cells carrying it is also transmissible to escherichia coli and from it to "cured" r. meliloti strains. | 1980 | 6988674 |
| indirect methods of determination of activity of root-nodule bacteria. | significant correlations exist between the ability of root-nodule bacteria to fix molecular nitrogen and some of their properties (accumulation of riboflavin, cobalamine, atp, cell pyrolysis, effect on plant vegetation characteristics) which can be used for quickly assessing the activity of the process in individual strains of rhizobia. | 1980 | 6991379 |
| biochemical genetics of nitrogen fixation. | | 1980 | 6999325 |
| a strain marker in rhizobium trifolii based on the absorption of congo-red. | it is widely recognized that most rhizobia absorb congo-red weakly when grown on agar media containing this dye. in contrast to this generalized behaviour, an ineffective strain of rhizobium trifolii (coryn) has been found which strongly absorbs the dye, producing growth of a very deep-red colour on yeast-extract mannitol agar, supplemented with congo-red (0.025 g/l). assays for dye absorption characteristics on this medium with 21 strains of r. trifolii showed that coryn could be readily differ ... | 1980 | 6999774 |
| a simple device of an improvised fermentor for production of rhizobial culture. | a simple new batch fermentor, suitable for both laboratory and industrial small scale cultivation of micro-organisms, particularly rhizobia, was designed and constructed. it was found to operate as a conventional stirring tank reactor. the device reliably ensures the sterility of cultivation, irrespective of its duration. its installation costs are relatively low, it does not show a high consumption of energy for stirring, the operation is very simple and does not require maintenance of complica ... | 1980 | 6999775 |
| chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton. | lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed. their pulmonary toxicity to animals was tested in inhalation tests. lipopolysaccharides from agrobacterium and xanthomonas were shown to differ from the others in that they contained no heptose and no non-hydroxylated fatty acids with a chain length of 12, 14, or 16 carbon atoms. lipopolysaccharides from pseudomonas putida, enterobacter agglomerans, and klebsiella oxytoca were found to cause a ... | 1980 | 7000706 |
| expression of large plasmids in the endosymbiotic form of rhizobium leguminosarum. | isolated plasmid dna from rhizobium leguminosarum was hybridised with cellular rna from broth-cultured bacteria and endosymbiotic bacteroids. from these hybridisation, experiments it is concluded that plasmid genes are strongly expressed in bacteroids and only weakly or not at all in bacteria. from the hybridisation of plasmid dna with the cloned structural nif genes of klebsiella pneumoniae it is shown that at least part of the nif genes are located on a plasmid. | 1980 | 7001365 |
| [testing the virulence of nodule bacteria cultivated on the embryos of leguminous plants]. | | 1980 | 7003326 |
| plasmid transfer within and between serologically distinct strains of rhizobium japonicum, using antibiotic resistance mutants and auxotrophs. | methionine-requiring and pantothenic acid-requiring auxotrophs of rhizobium japanicum usda 31, as well as highly antibiotic-resistant mutants of r. japonicum strains usda 31, usda 110, usda 138, and webster 48, were isolated. these mutants were used to transfer the p-1 group plasmids r68.45 and rp4 within and between strains usda 31, usda 110, and webster 48. attempts to demonstrate transfer of either plasmid to strain usda 138 were unsuccessful. | 1981 | 7007335 |
| large plasmids of fast-growing rhizobia: homology studies and location of structural nitrogen fixation (nif) genes. | a single large plasmid was isolated from multiplasmid-harboring strains rhizobium leguminosarum 1001 and r. trifolii 5. these single plasmids, as well as the largest plasmid detectable in r. phaseoli 3622, hybridized with part of the nif structural genes of klebsiella pneumoniae. in contrast, the plasmids of r. meliloti strains v7 and l5-30 did not show hybridization with the nif genes of k. pneumoniae, indicating that these genes might be located either on the chromosome or on a much larger pla ... | 1981 | 7009569 |
| rapid procedure for detection and isolation of large and small plasmids. | procedures are described for the detection and isolation of plasmids of various sizes (2.6 to 350 megadaltons) that are harbored in species of agrobacterium, rhizobium, escherichia, salmonella, erwinia, pseudomonas, and xanthomonas. the method utilized the molecular characteristics of covalently closed circular deoxyribonucleic acid (dna) that is released from cells under conditions that denature chromosomal dna by using alkaline sodium dodecyl sulfate (ph 12.6) at elevated temperatures. protein ... | 1981 | 7009583 |
| broad host range dna cloning system for gram-negative bacteria: construction of a gene bank of rhizobium meliloti. | a broad host range cloning vehicle that can be mobilized at high frequency into gram-negative bacteria has been constructed from the naturally occurring antibiotic resistance plasmid rk2. the vehicle is 20 kilobase pairs in size, encodes tetracycline resistance, and contains two single restriction enzyme sites suitable for cloning. mobilization is effected by a helper plasmid consisting of the rk2 transfer genes linked to a cole1 replicon. by use of this plasmid vehicle, a gene bank of the dna f ... | 1980 | 7012838 |
| kinetic mechanism of the hydrogen-oxidizing hydrogenase from soybean nodule bacteroids. | the kinetic mechanism of the unidirectional h2-oxidizing hydrogenase from soybean nodule bacteroids has been investigated with highly purified enzyme. measurements of the km for h2 vary from 0.97 to 2.6 microm, and the km for methylene blue varies from 6 to 17 microm. with h2 and methylene blue as substrates, the initial velocity patterns are intersecting. high levels of methylene blue are inhibitory (ki =2.4 mm): the inhibition is competitive vs. h2. co is a competitive inhibitor of h2 (ki = 15 ... | 1981 | 7016176 |
| agricultural microbiology. | | 1981 | 7025197 |
| genetics and regulation of nitrogen fixation. | | 1981 | 7027900 |
| plasmids specifying plant hyperplasias. | | 1981 | 7027906 |
| presence of trifoliin a, a rhizobium-binding lectin, in clover root exudate. | trifoliin a, a rhizobium-binding glycoprotein from white clover, was detected in sterile clover root exudate by a sensitive immunofluorescence assay employing encapsulated cells of rhizobium trifolii 0403 heat-fixed to microscope slides. its presence in root exudate was further examined by immunoaffinity chromatography. the binding of trifoliin a to cells was specifically inhibited by the hapten, 2-deoxyglucose. significantly higher quantities of trifoliin a were detected in root exudate of seed ... | 1981 | 7029001 |
| a simple and sensitive method for assay of a ribonuclease reductase system. | | 1981 | 7030133 |
| phenotypic expression of mutations in a wide-host-range r plasmid in escherichia coli and rhizobium meliloti. | eight different derivatives of r plasmid rp1 with thermosensitive mutations affecting maintenance in escherichia coli and pseudomonas aeruginosa were introduce into rhizobium meliloti. none of the plasmids showed a thermosensitive character in r. meliloti. on the other hand, a certain deletion mutation in rp1 was found to cause plasmid instability in rhizobia and agrobacteria, but not in e. coli. | 1982 | 7037750 |
| a coupled transcription-translation system from agrobacterium tumefaciens and its application to study ti plasmid expression in vitro. | a coupled transcription-translation system was isolated from a. tumefaciens. expression of plasmids pbr322 and pkt212 from e.coli, cloned fragments of ti plasmid (plasmids pss155 and pss156) and ti plasmid derivatives pal2802, pal2811, pal2821 and pal2832 was analysed in an a. tumefaciens cell-free system and compared with their expression in an e.coli cell-free system. new proteins of 41k and 44k appeared in a tumefaciens extracts, as the result of ti plasmid expression. these proteins were not ... | 1981 | 7038628 |
| uptake hydrogenase activity and atp formation in rhizobium leguminosarum bacteroids. | the role of uptake hydrogenase was studied in rhizobium leguminosarum bacteroids from the nodules of pisum sativum l. cv. homesteader. uptake hydrogenase activity, measured by the 3h2 uptake method, was dependent on o-consumption and was similar to h2 uptake measured by gas chromatography. km for o2 of 0.0007 atm (0.0709 kpa) and a km for h2 of 0.0074 atm (0.7498, kpa) were determined. h2 increased the rate of endogenous respiration by isolates with uptake hydrogenase (hup+) but had no effect on ... | 1982 | 7047503 |
| characterization and structural study of the dna-binding protein hrm from rhizobium meliloti. | | 1982 | 7049166 |
| site-specific mutagenesis of agrobacterium ti plasmids and transfer of genes to plant cells. | a general method is described for the use of tumor-inducing (ti) plasmids as experimental gene-vectors for plant cells. intermediate vectors, containing specific ti plasmid sequences and capable of replication in both e. coli and agrobacterium strains, were constructed and used for the in vitro introduction of isolated dna fragments into predetermined sites of the t-region derived fragments. site-specific inserts and/or deletions-substitutions in ti plasmids were produced by exchange of the modi ... | 1981 | 7050279 |
| ultrastructure of gram-negative cotton bacteria with different pulmonary toxicities. | the shedding of outer membrane material was observed by electron microscopy in typical gram-negative cotton bacteria, except agrobacterium sp. this finding is in accordance with the relative pulmonary toxicities of these bacteria. the presence of capsules did not seem to be correlated with the acute pulmonary toxicity of the bacteria. | 1982 | 7054127 |
| pulmonary toxicity of endotoxins: comparison of lipopolysaccharides from various bacterial species. | lipopolysaccharides from three gram-negative bacteria isolated from bale cotton and piggery air were analyzed for their chemical composition, and their pulmonary toxicity for guinea pigs, lethal toxicity for mice, and pyrogenicity for rabbits were measured. lipopolysaccharides from enterobacter agglomerans and citrobacter freundii had closely related chemical compositions; both were pyrogenic for rabbits and caused a dose-dependent influx of polymorphonuclear leukocytes into the airways of guine ... | 1982 | 7056574 |
| ferrisiderophore reductase activity in agrobacterium tumefaciens. | reduction of the iron in ferriagrobactin by the cytoplasmic fraction of agrobacterium tumefaciens strictly required nadh as the reductant. addition of flavin mononucleotide and anaerobic conditions were necessary for the reaction; when added with flavin mononucleotide, magnesium was stimulatory. this ferrisiderophore reductase activity may be a part of the iron assimilation process in a. tumefaciens. | 1982 | 7056702 |
| reconstitution of h2 oxidation activity from h2 uptake-negative mutants of rhizobium japonicum bacteroids. | an in vitro reconstitution of both methylene blue and oxygen-dependent h2 uptake activity from extracts of hup- (h2 uptake-negative) mutant strains of rhizobium japonicum bacteroids is described. cell-free extracts prepared from bacteroids formed from two different hup- mutants were mixed, and active h2 oxidizing particles formed. extracts from each mutant alone did not oxidize h2. the source of the components required for the complementation were soluble. mixing of membrane particles from the t ... | 1982 | 7056758 |
| relationship between nif plasmids of fast-growing rhizobium species and ti plasmids of agrobacterium tumefaciens. | by use of the southern blot hybridization technique the extent of dna homology was determined between the nif plasmid of a number of fast-growing rhizobium species and ti plasmids of the octopine (ptiach5) and nopaline (ptic58) type. dna sequences common to these plasmids were located on functional maps of the ti plasmids. no homology between nif plasmids and the t region of ti plasmids was detected. | 1982 | 7061382 |
| regulation of tryptophan genes in rhizobium leguminosarum. | twelve tryptophan auxotrophs of rhizobium leguminosarum were characterized biochemically. they were grown in complex and minimal media with several carbon sources, in both limiting and excess tryptophan. missing enzyme activities allowed assignment of all mutant to the trpe, trpd, trpb, or trpa gene, confirming earlier results with the same mutants (johnston et al., mol. gen. genet. 165:323-330, 1978). in regulatory experiments, only the first enzyme of the pathway, anthranilate synthase, respon ... | 1982 | 7061383 |
| mechanism of regulation of glucose transport in rhizobium leguminosarum. | multiple glucose transport systems were distinguished in rhizobium leguminosarum. we found nonlinear lineweaver-burk plots for the uptake of glucose, 2-deoxy-d-glucose, and alpha-methyl-d-glucoside, and this implied the existence of at least two uptake mechanisms. different patterns of inhibition of 2-deoxy-d-glucose uptake and alpha-methyl-d-glucoside uptake at 0.1 mm by various carbohydrates revealed differences in the stereospecificities of the transport systems. osmotic shock treatment aboli ... | 1982 | 7061388 |
| complementation analysis of agrobacterium tumefaciens ti plasmid mutations affecting oncogenicity. | a wide host range cosmid vector has been constructed by insertion of the lambda cos site into the plasmid prk2501. this cosmid, which is maintained in agrobacterium tumefaciens and is compatible with the ti plasmid, has been used to make a clone bank of the a. tumefaciens ptia6 plasmid. several ptia6 cosmids have been used to complement tn5-induced ti plasmid mutations. five avirulent mutations which map outside of the region of the plasmid maintained in plant tumours (t-dna) could be complement ... | 1982 | 7061395 |
| megaplasmids in the plant-associated bacteria rhizobium meliloti and pseudomonas solanacearum. | using analytical and preparative methods, we demonstrated the presence of megaplasmids with molecular weight larger than 450 x 10(6) in the two plant-associated bacteria rhizobium meliloti and pseudomonas solanacearum. such giant plasmids were found in 8 of 9 p. solanacearum strains tested and in all of the 18 r. meliloti strains tested. | 1982 | 7061401 |
| genetic transformation of rhizobium leguminosarum by plasmid dna. | we demonstrated the genetic transformation of rhizobium leguminosarum by r68.45 plasmid dna by freezing and thawing cell suspensions in the presence of r68.45 plasmid dna and 20 mm mgcl2. clones resistant to kanamycin and tetracycline were recovered at a frequency of 10(-8) per recipient cell. no colonies that were doubly drug resistant were recovered in parallel control experiments. | 1982 | 7061403 |
| d-glucosaminate dehydratase from agrobacterium radiobacter. physicochemical and enzymological properties. | the bacterial distribution of d-glucosaminate dehydratase [ec 4.2.1.26] was investigated and agrobacterium radiobacter (iam 1526) was found to have the highest enzyme activity. the enzyme was formed inducibly in a glycerol-urea medium by d-glucosamine, d-galactosamine, and d-glucosamine, but not by d-mannosamine. the enzyme purified from the cells grown in the glucosamine-glycerol-urea medium was shown to be homogeneous by ultracentrifugation. the molecular weight was determined to be about 66,0 ... | 1982 | 7068563 |
| [physiological and biochemical characteristics of the cells of a carrot gall tumor developing in weightlessness]. | the paper presents the results of experiments with the carrot tissues infected with agrobacterium tumefaciens flown onboard the biosatellite cosmos-1129 in cooperation with the us scientists. postflight, the respiratory activity of tumour cells was determined and k+ and na+ permeability of cell membranes was measured. the resulting data give evidence that in weightlessness the development of the carrot gall tumour is accompanied by changes in the above physiological and biochemical parameters. t ... | 1982 | 7070038 |
| secretion of trans-zeatin by agrobacterium tumefaciens: a function determined by the nopaline ti plasmid. | | 1982 | 7073755 |
| em5400, a family of monobactam antibiotics produced by agrobacterium radiobacter. ii. isolation and structure determination. | | 1982 | 7076578 |
| molecular mechanism for loss of nodulation properties of rhizobium trifolii. | of 18 rhizobium trifolii strains tested, 12 showed a high frequency of loss of nodulation ability after incubation in cultures at elevated temperatures. a correlation between loss of nodulation ability and loss of a large plasmid was demonstrated for r. trifolii. in some nonnodulating (nod-) mutants, deletions occurred instead of total elimination of the plasmid molecule. the maximum curing effect was observed in bacteria incubated at 35 degrees c. after 4 or more days of incubation at this temp ... | 1982 | 7076625 |
| ti plasmids as gene carriers. | | 1982 | 7079762 |
| characteristics of ti plasmids from broad-host-range and ecologically specific biotype 2 and 3 strains of agrobacterium tumefaciens. | agrobacterium tumefaciens strains isolated from crown gall tumors on grapevines in california were consistently of the biotype 3 group. all 11 of these strains were limited in their host range and harbored ti plasmids with molecular masses between 119 and 142 megadaltons (mdal) as well as a larger cryptic plasmid of greater than 200 mdal; occasionally a smaller cryptic plasmid of 65 mdal was also present. ti plasmids o these strains have dna sequences in common with ti plasmids of octopine and n ... | 1982 | 7085561 |
| identification and mobilization by cointegrate formation of a nodulation plasmid in rhizobium trifolii. | a nodulation plasmid, prtr-514a, of molecular size 180 megadaltons (mdal) was identified in rhizobium trifolii strain nzp514. this plasmid was absent in both spontaneous and heat-cured nod- derivatives of nzp514, and these strains were unable to induce root hair curling. the ability to nodulate clover was transferred from the wild-type strain to a nod- derivatives, pn104, with the broad-host-range plasmid r68.45 (39 megadaltons) at a cotransfer frequency of about 4 x 10(-3). most of the nod+ tra ... | 1982 | 7085562 |
| structural studies of alfalfa roots infected with nodulation mutants of rhizobium meliloti. | alfalfa roots infected with four nodulation defective (nod-) mutants of rhizobium meliloti which were generated by transposon tn5 mutagenesis were examined by light and electron microscopy. in one class of nod- mutants, which we can nonreactive, the bacteria did not induce root hair curling or penetrate host cells. in a second class of nod- mutants, which we call reactive, the bacteria induced some root hair curling and entered root epidermal cells, although no infection threads were formed. in ... | 1982 | 7085566 |
| positive selection of nodulation-deficient rhizobium phaseoli. | a high proportion of rhizobium phaseoli mutants that survived infection with phage f1 were found to be nodulation deficient. two that were examined in detail had internal defects in addition to the expected surface defects. one internal defect was in the enzyme phosphoglucose isomerase. the use of phages to select appropriate mutants should apply generally in any system in which surface components are involved. | 1982 | 7085572 |
| lipid-bound saccharides in rhizobium meliloti. | the lipid-bound saccharides formed by incubation of uridine diphosphate glucose with a particulate enzyme of rhizobium meliloti were studied. they behaved like polyprenyl diphosphate saccharides when treated with ammonia or hot phenol, when catalytically hydrogenated, and on deae-cellulose chromatography. the saccharide moieties obtained after heating at ph 2 for 10 min at 100 degrees c were separated with a gel filtration column. the following compounds were detected: galactose, glucosyl beta 1 ... | 1982 | 7085601 |
| regions of homology between tumorigenic plasmids from agrobacterium rhizogenes and agrobacterium tumefaciens. | | 1982 | 7089090 |
| plasmids and stability of symbiotic properties of rhizobium trifolii. | a conjugal plasmid which encodes both peak nodulation genes and nitrogenase genes, and which is labeled with the transposon tn5, was transferred to a wild-type rhizobium trifolii strain to examine the stability and expression of the host range and fixation (fix+) phenotypes. transconjugates were isolated which were shown to initially form nitrogen-fixing nodules (nod+ fix+) on both clovers and peas. these hybrid strains were then repeatedly passaged through either pea or clover nodules or onto a ... | 1982 | 7096265 |
| heme biosynthesis in rhizobium. identification of a cloned gene coding for delta-aminolevulinic acid synthetase from rhizobium meliloti. | a symbiotically important gene system in rhizobial species is the heme biosynthetic pathway. a mutant having reduced levels of delta-aminolevulinic acid synthetase, the first unique enzyme in this pathway, was obtained in rhizobium meliloti 102f34 by n-methyl-n'-nitro-n-nitrosoguanidine mutagenesis. enzyme activity ranged from 3-13% of the wild type. alfalfa plants inoculated with the rhizobium synthetase mutant grew no better than uninoculated controls and formed only small white nodules which ... | 1982 | 7096330 |
| structural analysis of complex carbohydrates using high-performance liquid chromatography, gas chromatography, and mass spectrometry. | | 1982 | 7098937 |
| properties of rhizobium leguminosarum isolated from various regions of morocco. | twenty-eight isolates of rhizobium leguminosarum capable of nodulating broad-bean (vicia faba l. var. major) were collected throughout morocco and characterized by using morphological, physiological, biochemical and serological tests. the properties of isolates from within a given climatic zone varied as much as the properties of isolates from different zones. the isolates were adapted to desiccation, but were not adapted to temperatures higher than 37 degrees c. a high degree of heterogeneity w ... | 1982 | 7103311 |
| tumor induction by agrobacterium tumefaciens: analysis of the boundaries of t-dna. | molecular cloning has been used to isolate the ends of that portion of the tumor-inducing (ti) plasmid of agrobacterium tumefaciens which has been designated t-dna and which has been transferred to the genome of tobacco crown gall tumor cells. analysis of the dna sequences of the plant border clones compared with the corresponding sequences of the ti plasmid suggests that the mechanism of transferred dna integration and subsequent stabilization is precise at the right border and imprecise on the ... | 1982 | 7108407 |
| [antibiotic resistance of nodular bacteria]. | the effect of several antibiotics on 4 rapid-growing rhizobia, i. e. r. phaseoli, r. leguminosarum, r. trifolii and r. meliloti and 3 slow growing rhizobia, i. e. r. vigna, r. japonicum and r. lupini was studied. it was shown that 4 of the species, i. e. r. meliloti, r. japonicum, r. vagna and r. lupini had multiple drug resistance. a tetracycline resistant mutant mc of r. japonicum was isolated. | 1982 | 7114827 |
| tumor reversal in plants. | | 1982 | 7122580 |