Publications

regulation of arginine biosynthesis in azotobacter vinelandii nq [proceedings].		1979	428667
two crystal forms of azotobacter ferredoxin.	two crystal forms of azotobacter vinelandii (4fe-4s)2 ferredoxin i (fd i) have been grown which are suitable for high resolution x-ray diffraction studies. tetragonal crystals grow as square bipyramids from ammonium sulfate and tris buffer using a temperature gradient. the space group is p41212 (or p43212) with a = 55.3, c = 95.9 a and 1 molecule/asymmetric unit. triclinic crystals grow as plates or laths from ammonium sulfate and phosphate buffer at constant temperature. the space group is p1 w ...	1979	429371
fatty acids in phospholipids of cells, cysts, and germinating cysts of azotobacter vinelandii.	cyclopropane fatty acids constitute 25% of the phospholipid acyl groups in cysts of azotobacter vinelandii. these are lost by dilution during germination when the synthesis of the fatty acids characteristic of vegetative cell phospholipids commences.	1979	438125
polyamines as activators of amp nucleosidase from azotobacter vinelandii.	polyamines at physiological concentrations activate amp nucleosidase from azotobacter vinelandii. biological significance of the activation is discussed in relation to the control of adenylate energy charge and the purine nucleotide synthesis in prokaryotes.	1979	446646
azotobacter cytochrome b557.5 is a bacterioferritin.		1979	450081
structure of the iron-sulphur clusters in azotobacter ferredoxin at 4.0 a resolution.		1979	450082
5-n-alkylresorcinols from encysting azotobacter vinelandii: isolation and characterization.	azotobacter vinelandii was found to form novel lipid compounds when encystment was initiated by 0.2% beta-hydroxybutyrate. an examination of these compounds led to the isolation and characterization of 5-n-heneicosylresorcinol, 5-n-tricosylresorcinol, and their galactoside derivatives.	1979	457611
phosphate-limited culture of azotobacter vinelandii.	batch cultures of azotobacter vinelandii grown in phosphate-deficient media were compared with control cultures grown in phosphate-sufficient media. phosphate limitation was assessed by total cell yield and by growth kinetics. although cell protein, nucleic acids, and early growth rate were unaffected by phosphate deficiency, cell wall structure, oxygen uptake, and cell viability were significantly affected. also, phosphate-limited cells contained much larger amounts of poly-beta-hydroxybutyric ...	1979	457614
isolation and properties of a glycohydrolase specific for nicotinamide mononucleotide from azotobacter vinelandii.	a glycohydrolase that catalyzes the irreversible conversion of nmn to nicotinamide and ribose 5-phosphate has been partially purified from a sonic extract of azotobacter vinelandii. the enzyme is highly specific for nmn. nad, nadp, nicotinic acid-adenine dinucleotide, nicotinamide riboside and alpha-nmn are not significantly hydrolyzed by this enzyme, nor do they compete with nmn. the enzyme also exhibits an absolute dependence on guanylic acid derivatives with following order of relative effect ...	1979	457634
effect of aldicarb on the growth, respiration and (14c) - glucose metabolism of axotobacter chroococcum beij.	aldicarb [2-methyl-2(methyl thio) propionaldehyde-o-methyl carbamoyl oxime], which forms the active ingredient of a systemic oximic carbamate insecticide, at 2 ppm level did not affect the in vitro growth and respiration of azotobacter chroococcum beij, while concentrations at 5 ppm and 10 ppm levels were inhibitory. the insecticide treatment at 10 ppm level suppressed the assimilation of (14c) - glucose in the whole cells and in the cellular constitutents viz., cold - tca soluble, hot tca solub ...	1979	469177
nitrogen fixers in the rhizosphere of certain desert plants.	six species of common desert range plants; achillea sp., aristida plumosa, artemisia herba-alba, haloxylon articulatum, and heliotropium ramosissimum were colleted from western desert in iraq. counts of azotobacter spp. and total bacteria were estimated in both rhizosphere and non-rhizosphere soils. biomass and total nitrogen content of the plants were determined. the r/n ratio (ratio between rhizosphere to non-rhizosphere) for azotobacter sp. ranged between 1 to 19.5 with an average of 4.96. th ...	1979	473956
effect of some pesticides on certain micro-organisms, contributing to soil fertility.	a pot experiment was run for studying the effect of temik (insecticide and nematocide), orthocide (fungicide), and treflan (herbicide) on certain desirable soil micro-organisms. total counts of bacteria, actinomycetes or fungi were mostly lower in the treated than in the untreated soil. aerobic cellulose-decomposers were either stimulated or depressed. despite the temporarily slight stimulation, observed in some instances at the initial periods, the effect of the pesticides on counts of azotobac ...	1979	473959
associative symbiosis of azotobacter chroococcum and higher plants.	the association between a selected strain of azotobacter chroococcum and seven plants was investigated in water cultures under sterile conditions. azotobacter population progressively increased in the nutrient solution and on the rhizoplane. microbial propagation depends on the type of plant, being much higher in presence of wheat, followed by barley, maize, broad bean, and cotton, while in presence of fenugreek and lentil lower rates of multiplication were recorded. inoculation increased the dr ...	1979	473964
effect of azotobacter inoculation on plant growth and soil nitrogen.	the validity of seed bacterization with azotobacter chroococcum in soils of variable densities of naturally present azotobacters was studied. inoculation of barley grains had no effect on counts of total microflora, neither in rhizosphere nor in root-free soil, but significantly increased azotobacter population, especially in the rhizosphere. the rate of colonization in the root region was much higher when soil initially harboured low azotobacter densities. bacterization improved plant growth an ...	1979	473965
optimal conditions for transformation of azotobacter vinelandii.	optimal transformation of azotobacter vinelandii op required a 20-min incubation of the competent cells with deoxyribonucleic acid at 30 degrees c in buffer (ph 6.0 to 8.0) containing 8 mm magnesium sulfate. nitrogen-fixing transformants of nitrogen fixation-deficient recipients could be plated immediately on selective medium, but transformants acquiring rifampin and streptomycin resistance required preincubation in nonselective medium. the three phenotypes achieved an approximately equal and st ...	1979	479104
effects of monovalent cations on amp nucleosidase from azotobacter vinelandii.	the effect of monovalent cations on the purified amp nucleosidase (amp phosphoribohydrolase, ec 3.2.2.4) from azotobacter vinelandii was investigated. all the monovalent cations were activators of the enzyme: rb+ and cs+ were the most effective, followed by k+, na+, nh4+ and li+ in that order. the apparent ka for mgatp and nh values (hill's interaction coefficient) decreased from 0.9 to 0.1 mm, and from 4 to 1, respectively, with the increase in k+ concentration, suggesting that the cation effec ...	1979	486499
respiratory-chain characteristics of mutants of azotobacter vinelandii negative to tetramethyl-p-phenylenediamine oxidase.		1979	488089
effect of organic matter supplementation on nitrogen transformations in soils. i. chemical and bacteriological changes.	the effect of supplementation with different organic materials on nitrogen transformations and on certain bacterial groups in soil was studied. addition of wide c/n ratio organic matter, sawdust and maize stalks prevented no3-n from being lost through leaching out or dentrification and favoured the development of azotobacter and n2-fixing clostridia that in turn resulted in marked gains in nitrogen through n2-fixation. nitrifying bacteria were adversely affected. application of such materials to ...	1979	494849
quantitative effects of some pesticides on certain physiological groups of micro-organisms in soil.	quantitative effects of temik (insecticide and nematocide), orthocide (fungicide), or treflan (herbicide), added to soil at field rate application, on counts of certain desirable soil microorganisms were studied. in the presence of any of the pesticides, counts of aerobic cellulose-decomposers were either stimulated or depressed. despite the temporarily slight stimulation, observed in some instances of the initial periods, the effect of any pesticide on counts of azotobacter, n-fixing clostridia ...	1979	494851
seed inoculation with azotobacter chroococcum in sand cultures and its effect on nitrogen balance.	the effect of bacterization of barley grains with a selected strain of azotobacter chroococcum was studied. in nitrogen-deficient sand, seed inoculation increased plant length, dry weight, nitrogen content in addition to a significant increase in soil nitrogen. the density of the organism on grains had a slight positive effect. irrigation with kno3-containing nutrient solution suppressed nitrogen fixation, but inoculation still had a pronounced stimulating effect on plants. in presence of mixed ...	1979	494854
characterization of an oxygen-stable nitrogenase complex isolated from azotobacter chroococcum.	in crude cell-free extracts of azotobacter chroococcum, nitrogenase was much less sensitive to irreversible inactivation by o2 than was the purified enzyme. when nitrogenase was partially purified by anaerobic discontinuous sucrose-density-gradient centrifugation, o2-tolerance was retained. this preparation was considerably enriched in four polypeptides, three of which were derived from the mo-fe(molybdenum-iron) protein and fe (iron) protein of nitrogenase. the fourth was purified to homogeneit ...	1979	518541
the oxidation-reduction potentials of cytochrome o + c4 and cytochrome o purified from azotobacter vinelandii.	oxidation-reduction titrations of azotobacter vinelandii cytochrome o + c4 and cytochrome o were performed with simultaneous potential and absorbance measurements under anaerobic conditions. cytochrome c4 has a midpoint potential (em, 7.4) of 260mv and purified cytochrome o has an em, 7.4 of -18mv. little change in the midpoint potential of cytochrome o was observed when titrated in the ph range 6.2--9.8.	1979	518554
[transformation of the herbicide 2,4-d in an azotobacter culture].	transformation of the herbicide 2,4-d[14c] was studied in the cultures of azotobacter chroococcum, azotobacter vinelandii and azotobacter agile. these cultures assimilated 2,4-d and metabolized it. the products of transformation included phenol derivatives, water-soluble products, and carbon dioxide. about 15% of the herbicide taken up by the cells was bound to protein.	1979	530139
induction of haemorrhagic necrosis in a murine tumour by products from the culture fluid of azotobacter.	macromolecules in the supernatant from cultures of the nitrogen-fixing bacterium azotobacter chroococcum when given systemically induce permanent regression of established grafts of a syngeneic murine lymphoma. the effect mimics that produced by endotoxin in that haemorrhagic necrosis is induced in the tumour, but the ratio of the toxic dose to the dose needed to cause tumour regression is greater than for this culture supernatant than for endotoxin.	1979	534677
effects of oxygen tension on the lipid composition of azotobacter chroococcum.	lipid content and composition were determined in azotobacter chroococcum grown, under nitrogen-fixing conditions, in continuous culture with intense aeration under atmospheres containing between 5 and 40% o2. total lipid content remained almost constant at approximately 9% of dry weight. phospholipid content was maximal at 20% o2 where it accounted for 92% of total lipid, and was minimal at 40% o2. phosphatidylethanolamine was the only species of phosphatide detected in this fraction. neutral li ...	1979	540251
association between azotobacter and other soil bacteria and its effect on nitrogen fixation.	the association between a. vinelandii and either agrobacterium sp. or micrococcus sp., which are usually found as contaminants in azotobacter cultures, was investigated. in comparison with pure cultures, association increased the microbiol counts in addition to increasing nitrogen fixation rates and efficiency. in liquid cultures higher azotobacter densities were observed in the top 5 cm of the column concomitant with lowering the economic coefficient of utilization of carbonaceous compounds, wh ...	1979	543344
nitrogen-fixing capacity of azotobacter as affected by the type and depth of substrate.	sixty isolates, representing the different types of azotobacters in egyptian soils, were studied for their n2-fixing capacity. when a. chroococcum and a. vinelandii were grown in shallow layers of n-deficient liquid medium, nitrogen gains ranged from 48 to 92 and from 20 to 120 ppm with efficiencies of n2-fixation from 15.8 to 50.0 and from 16.6 to 21.2 mg n fixed/g c oxidized, respectively. culturing in deep layers generally lowered the nitrogen gains and the oxidation of carbon, but at differe ...	1979	543345
occurrence of certain physiological groups of soil micro-organisms in the rhizosphere and rhizoplane of watermelon, cucumber, and cowpea.	a field experiment was run for studying the occurrence of ammonifiers, azotobacter, aerobic cellulose-decomposers, and nitrifiers in rhizosphere soils as well as in rhizoplane samples of watermelon, cucumber, or cowpea at different stages of growth. in unamended soil, all the heterotrophs were generally stimulated in the rhizosphere of each plant, especially the leguminous one, resulting in positive rhizosphere effects. in amended soil, on the other hand, both negative and positive (but lower th ...	1979	545941
studies on azotobacters prevailing in egyptian soils.	soil samples from different locations in egypt, representing various types of soils, different degrees of fertility and under various standing crops, were used for isolating azotobacter strains. sixty azotobacter isolates were obtained, and a. chroococcum was found to be the most predominant species (56 isolates), while a. vinclandii was sporadically found (4 isolates). other species of the genus azotobacter were not detected in the examined soil samples. isolates were studied for their morpholo ...	1979	549386
studies on the aerobic non-symbiotic nitrogen-fixing bacteria, other than azotobacter, in egyptian soils.	twenty isolates of micro-organisms capable of growing on nitrogen-deficient medium and found as contaminants in azotobacter cultures were isolated from egyptian soils and studied for their morphological, cultural, and physiological properties. these micro-organisms s are members of rhizobiaceae, pseudomonadaceae, achromobacteriaceae, enterobacteriaceae, micrococcaceae, bacillaceae, and streptomycetaceae as well as some yeasts. in nitrogen-free medium the micro-organism fixed only small amounts o ...	1979	549387
a preliminary crystallographic study of isocitrate dehydrogenase from azotobacter vinelandii.		1977	592382
[monosaccharide composition of the exopolysaccharides of oligonitrophilic bacteria].	exopolysaccharides from ten strains of oligonitrophilic bacteria were found to contain galactose, glucose and mannose. strains belonging to the genus mycobacterium contained also fucose, ramnose and three sugars that had not been identified: two of them were lipophilic and one had a lower rf than ramnose. a correlation has been established between the composition of monosaccharides, their molar ratios in exocellular polysaccharides of oligonitrophilic bacteria, and the taxonomy of these microorg ...	1977	600103
a convenient apparatus and tracking dye for anaerobic analytical polyacrylamide-gel electrophoresis.		1977	603027
influence of partial pressures of acetylene and nitrogen upon nitrogenase activity of species of beijerinckia.	acetylene reduction and nitrogen fixation by strains of beijerinckia indica and b. lacticogenes increased with increased partial pressures of acetylene and nitrogen up to 80 kpa. the optical emission spectrophotometric method was used for the determination of 14n:15n ratios. the molar ratios of acetylene to nitrogen varied greatly from the theoretical value.	1977	614010
kinetics of adenosine monophosphate nucleosidase inactivation by phosphate and protection by substrate and allosteric activator.		1978	632260
transformation of azotobacter vinelandii strains unable to fix nitrogen with rhizobium spp. dna.	the phenotypes of azotobacter vinelandii atcc 12837 strains defective in nitrogen fixation (nif-) were characterized by intrageneric transformation with known nif- strains of a. vinelandii op. these former mutant strains were used as recipients for intergeneric transformation by deoxyribonucleic acid (dna) prepared from rhizobium spp. to determine if the rhizobia would transform the azotobacter nif- phenotypes to nif+. the frequency of nif+ transformants using rhizobium dna was always less than ...	1978	647476
oxygen and the enzymes of obligate aerobes.		1978	648715
isolation and partial characterization of two different subunits from the molybdenum-iron protein of azotobacter vinelandii nitrogenase.	the molybdenum-iron protein of azotobacter vinelandii nitrogenase was separated into two subunits of equal concentration by ion exchange chromatography on sulfopropyl (sp) sephadex at ph 5.4 in 7 m urea. better than 90% yield of each subunit was obtained on a preparative scale if the reduced carboxymethylated molybdenum-iron protein was incubated at 45 degrees c for 45 min prior to chromatography. without the heating step low yields of the subunits were obtained. although the amino acid composit ...	1978	649581
acetylene reduction by the iron-molybdenum cofactor from nitrogenase.		1978	656098
transfer from rhizobium japonicum to azotobacter vinelandii of genes required for nodulation.	a mutant strain of azotobacter vinelandii that is unable to fix n2 (nif-) was transformed to nif+ with dna from rhizobium japonicum. of 50 nif+ transformants tested, 3 contained the o antigen-related polysaccharide that is present on the cell surface of a nodulating r. japonicum strain, but is absent from a non-nodulating mutant strain.	1978	659367
[biological activity of the soils of the rice irrigation systems in the southern ukraine].	the biological activity of soils was studied in the irrigation systems of the southern ukraina. aerobic microorganisms were found to be widely distributed in all these soils. the cell number of azotobacter and the activity of nitrogen fixation differed among various irrigation systems. active nitrogen-fixing microbial associations were isolated from the soils; some of them were capable of fixation of 19.4 mg n per 1 g of assimilated glucose. the microbiological processes of certain irragation sy ...	1978	661642
studies on the red oxidase (cytochrome o) of azotobacter vinelandii.		1978	666783
the hydrogen cycle in nitrogen-fixing azotobacter chroococcum.	h2 will support nitrogenase activity (c2h2 reduction) in azotobacter chroococcum with or without added carbon substrate. results show that h2 is metabolised to transfer electrons to nitrogenase and to the respiratory chain to produce atp. h2-supported nitrogenase activity is most significant at low carbon substrate concentrations, but also occurs at saturating concentration. continuous cultures of n2-fixing a. chroococcum evolved h2 from nitrogenase under o2-n2- and c-limited conditions. this h2 ...	1978	667178
membrane energization in relation with nitrogen fixation in azotobacter vinelandii and rhizobium leguminosarum bacteroids.	nitrogen fixation in a. vinelandii and r. leguminosarum bacteroides shows identical characteristics with respect to the dependence on membrane energization, the sensitivity to uncouplers, the atp/adp-ratio, and the dependences on flavodoxinhydroquinone as electrondonor. although we have been successful in preparing inside-out vesicles which can be energized, attempts to couple these membranes to n2-ase were still unsuccessful. one of the major problems could be the failure to energize these vesi ...	1978	667180
direct mass-spectrometric determination of the relationship between respiration, hydrogenase and nitrogenase activities in azotobacter chroococcum.		1978	667186
involvement of the cytoplasmic membrane in nitrogen fixation by rhizobium leguminosarum bacteroids.	1. the nitrogen-fixing efficiency of freshly prepared suspensions of rhizobium leguminosarum bacteroids from pea root nodules was considerably enhanced by addition of bovine serum albumin. evidence was found that during preparation of bacteroids the cell membrane is exposed to the uncoupling effect of free fatty acids and to plant phospholipase d activity. both effects could be counteracted by bovine serum albumin. 2. a technique was developed by which concentrations of free o2 and nitrogenase a ...	1978	668685
effect of high pressure, detergents and phospholipase on the break in the arrhenius plot of azotobacter nitrogenase.	it is shown that lipids are responsible for the breaks in the arrhenius plots of azotobacter nitrogenase. the physical evidence is that temperature at which the break occurs increases with increasing pressure by 20 k/1000 atm. this is in agreement with the pressure dependence of the transition temperature of several synthetic phospholipids. we also find the same pressure dependence for the broad transitions observed in escherichia coli phosphatidylethanolamine and in the membrane lipids from azo ...	1978	668700
microbial changes in clover rhizosphere after foliar and soil application of cobalt.	application of cobalt(ii) nitrate to the leaves of red clover (trifolium pratense l.) resulted in a pronounced increase of dry weight and the number of root nodules. counts of bacteria in the rhizosphere, content of ammonia and production of carbon dioxide in rhizosphere soil were also higher, whereas the content of nitrates decreased. differences in the counts of bacteria, actinomycetes, azotobacter, anaerobic bacteria and cellulose decomposing bacteria in the rhizosphere of control and treated ...	1978	669491
regulatory properties of the nitrogenase from rhodopseudomonas palustris.	ammonium salts, glutamine, asparagine, and urea cause an immediate inactivation (switch-off) of light-dependent acetylene reduction in intact cells of the photosynthetic bacterium rhodopseudomonas palustris. this effect is reversible showing the same kinetic pattern of inactivation and reactivation with all effector compounds. its duration depends on the amount of effector added to the cells. both nitrogenase components are found catalytically active in a cell-free preparation after enzyme switc ...	1978	678011
pseudomonas ovalis ferredoxin: similarity to azotobacter and chromatium ferredoxins.		1978	680138
ultrastructural and physiological changes occurring upon germination and outgrowth of azotobacter vinelandii cysts.	dormant cysts of azotobacter vinelandii germinated at 30 degrees c in burk nitrogen-free media containing 1% glucose. samples taken at intervals and examined by electron microscopy revealed that as germination progressed, vesicle-like and fibrillar structures became visible in the intine region. lamellae associated with the cell membrane appeared in the central body at 6 h post-initiation of germination. both electron micrographic and chemical analysis showed that the poly-beta-hydroxybutyrate c ...	1978	681284
reactions of phosphorothioate compounds catalyzed by adenylosuccinate synthetase. steady state and pre-steady state kinetic studies.		1978	681347
effect of uranyl and molybdate ions on microbial fixation of nitrogen.	the addition of molybdate in presence of uranyl acetate causes a considerable increase in nitrogen fixation in all the species of nitrogen-fixing azotobacter, studied in this paper, as compared to the case in which these ions are taken separately (4, 3).	1978	685534
the role of adenosine monophosphate nucleosidase in the regulation of adenine nucleotide levels in azotobacter vinelandii during aerobic-anaerobic transitions.		1978	708078
kinetic studies on electron transfer and interaction between nitrogenase components from azotobacter vinelandii.	kinetic properties of electron transfer by nitrogenase of azotobacter vinelandii are dependent on the concentration of the two components of nitrogenase. an excess of the mofe protein inhibits electron transfer in a distinctive manner, and the inhibition is reversed by increasing levels of reductant. the saturation curve for fe protein is hyperbolic, indicating that only one fe protein molecule per mofe protein is required for full activity in atp hydrolysis and electron transfer. these results ...	1978	708696
potentiometric titration of the high- and low-potential 4fe-4s* centers of azotobacter vinelandii ferredoxin i.	the high-potential 4fe-4s* center ofazotobacter vinelandii ferredoxin i has been titrated potentiometrically by a reductive procedure. the absorbance decrease at 510 nm accompanying the reduction of the high-potential center titrated with an em of 320 mv (n = 1). the low-potential 4fe-4s* center was titrated by using the absorbance decrease at 410 nm to monitor its reduction. this center exhibited an em of -424 mv (n = 1).	1978	711680
[studies on the effects of atrazine and simazine on the n-binding bacteria azotobacter and beijerinckia in the ferralitic soils of cuba].	in two cuban locations (santiago de las vegas and jovellanos) the effect was investigated of increasing atrazin and simazin applications (0, 4, 8, 16 kg/ha) to the number of azotobacter and beijerinckia colonies in weakly ferrallitic soils 7 and 15 days after their application during the rainy and dry seasons. the results were as follows: 1. the number of the beijerinckia colonies is higher in all variants than that of azotobacter. 2. beijerinckia and azotobacter are stimulated up to 7 days, par ...	1978	728049
nitrate reductase from azotobacter chroococcum. inactivation by oxidizing agents and reactivation with dithioerythritol.		1978	728161
nitrogenase: properties of the catalytically inactive complex between the azotobacter vinelandii mofe protein and the clostridium pasteurianum fe protein.	the catalytically inactive complex generated by the combination of the azotobacter vinelandii mofe protein (av1) and the clostridium pasteurianum fe protein (cp2) inhibits n2 reduction, c2h3 reduction, h+ reduction and atp hydrolysis catalyzed by the homologous nitrogenases. kinetic data indicate that the inactive complex consists of two molecules of cp2 to one molecule of av1, with values for the inhibitor constant in the range of 1--10 nm. inhibition of c. pasteurianum nitrogenase by av1 produ ...	1978	728444
induction of transformation competence in azotobacter vinelandii iron-limited cultures.	azotobacter vinelandii strains uw (nif+) or uw1 (nif-) were induced to form competent cells by growing cultures in burk medium without added iron. competent cells were generated in either liquid or solid medium. the competent culture was highly colored by the characteristic fluorescent green pigment of a. vinelandii but all pigmented cultures were not competent. in liquid culture, competent cells required a fixed nitrogen source (ammonia, nitrate, or urea) that was also a nitrogenase repressor. ...	1978	747819
microbial fixation of nitrogen in presence of sodium tungstate.	the effect of sodium tungstate in the culture media of three different species of azotobacter, isolated from allahabad soil, was studied. it was observed that the presence of tungstate in the culture media of bacterial sample a2 and a3 decreased the fixation of nitrogen, except in the bacterial sample a1.	1978	749407
microbial fixation of nitrogen in presence of lanthanum sulphate with sodium molybdate.	the effect of lanthanum sulphate together with 100 micrometer of sodium molybdate show that there is considerable increase in nitrogen fixation and carbon consumption in the culture medium of nitrogen-fixing azotobacter species a1 and a2, isolated from allahabad soil. but these combination decrease the nitrogen fixation and carbon consumption in case of another species, azotobacter a3, of the same soil.	1978	749409
nitrogenase xi: mössbauer studies on the cofactor centers of the mofe protein from azotobacter vinelandii op.	we have studied the mofe protein from azotobacter vinelandii op with mössbauer spectroscopy in applied magnetic fields up to 50 kg. the results are as follows. (1) the mössbauer spectra of the s = 3/2 centers, which reside on the cofactor of nitrogenase, have been decomposed into six subcomponents. this suggests that each center contains 5-7, most probably 6, fe atoms, thus confirming our earlier conclusions which were based on the quantitation of epr data and on the assumption that the mofe pro ...	1979	760805
[technics for isolation of atp from microorganisms].	a technique for isolation of atp from microorganisms is suggested. the technique is based on increasing permeability of the cell membrane for substances of low molecular weight during dehydration. treatment of the dry biomass with boiling water gives a higher yield of atp from the cells of eukaryote and prokaryote microorganisms as compared with other techniques, and permits to register the amount of apt at the moment of experiment.	1975	765686
expression of klebsiella nitrogen fixation genes (nif) in azotobacter.		1976	768779
kinetic studies of bacillus polymyxa nitrogenase.	nitrogenase from the facultative anaerobe bacillus polymxa was separated into its component proteins, which were recombined in the ratio that produced optimal specific activity (125 to 175 nmol of c2h2 reduced/min per mg of total protein). the apparent michaelis constants (km)for the magnesium adenosine triphosphate complex, reducible substrates azide, acetylene, and n2 and the nonphysiological electron donor hydrosulfite (s2o42-) were determined to be 0.7, 0.7, 0.2, 0.06, and 0.03 mm, respectiv ...	1976	770451
the molybdenum--iron protein of klebsiella pneumoniae nitrogenase. evidence for non-identical subunits from peptide 'mapping'.	the molybdenum- and iron-containing protein components of nitrogenase purified from klebsiella pneumoniae, azotobacter vinelandii, azotobacter chroococcum and rhizobium japonicum bacteroids all gave either one or two protein-staining bands after sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, depending on the commercial brand of sodium dodecyl sulphate used. the single band obtained with k. pneumoniae mo-fe protein when some commercial brands of sodium dodecyl sulphate were used in t ...	1976	779772
energetics of low affinity amino acid transport into brain slices.	it appears possible to dissect and study some of the potential energy sources for amino acid transport in brain slices despite the apparent complexity of the tissue in comparison to that of isolated bacterial vesicles23. the uptake capability of the tissue may be inadvertently damaged in some experimental protocols so that very special controls must be used to ensure that the treatment did not somehow inactivate the very mechanism that thereafter will be tested. we have presented some evidence t ...	1976	782193
the apparent atp requirement for nitrogen fixation in growing klebsiella pneumoniae.	the apparent atp requirement for n2 fixation in klebsiella pneumoniae was high (the atp/n2 molar ratio was 29 when estimated in anaerobic glucose-limited chemostat cultures) compared with that determined previously in azotobacter chroococcum and in clostridium pasteurianum. the high value was probably not due to unfavourable temperature, phosphate concentration or ph. the apparent atp requirement for n2 fixation was probably no lower in 02-limited chemostat cultures than in anaerobic glucose-lim ...	1976	784906
symmetry and asymmetry of the pyruvate dehydrogenase complexes from azotobacter vinelandii and escherichia coli as reflected by fluorescence and spin-label studies.	fluorescence-lifetime measurements of fad bound to lipoamide dehydrogenase from azotobacter vinelandii and escherichia coli were performed. it is shown from these results that the two fad groups in the isolated dimeric enzyme, as well as in the enzyme in the intact complex of e. coli, are in non-equivalent surroundings. this contrasts with the near equivalence of the fad groups of both the enzyme and complex isolated from a. vinelandii. reduction of the complex with mg2+, thiamine pyrophosphate ...	1976	795671
[regulation of nitrogenase biosynthesis in microorganisms].		1975	803994
[biochemistry and genetics of organic acid transport in bacteria].		1975	804772
adenine nucleotide pool variations in intact nitrobacter winogradskyi cells.	1. the atp pool in nitrobacter winogradskyi cells was determined by means of the luciferin-luciferase enzyme system and the adp and amp pools were measured after enzymatic conversion into atp. 2. in the first 10 min after addition of nitrite to endogenously respiring cells, which had stood for 5--16 days after completion of the nitrite oxidation, the atp pool dropped about 60%. 3. during the log phase the atp pool was approx. 20--40 pmoles/5 mug cell-n. during growth it increased exponentially b ...	1975	808183
binding and oxidation-reduction of monoamine oxidase-type 8alpha-(s-peptidyl) flavins with azotobacter (shethna) flavodoxin.		1975	809042
the effect of cooling and warming rates on the survival of a variety of bacteria.	cooling and warming rates affect bacterial survival profoundly with all bacteria tested (azotobacter chroococcum, klebsiella aerogenes, salmonella typhimurium, pseudomonas aeruginosa, streptococcus faecalis) behaving similarly. most bacteria were sensitive to salt on freezing and thawing. viabilities of population frozen and thawed in saline were always less (by at least 20%) than comparable ones frozen in water alone. under these conditions, s. faecalis was resistant to the presence of sodium c ...	1976	814981
aquatic acetylene-reduction techniques: solutions to several problems.	previous methods of performing aquatic acetylene-reduction assays are described and several problems associated with them are discussed. a refinement of these older techniques is introduced and problems that it overcomes are also discussed. a depth profile of nitrogen fixation (c2h4 production), obtained by the refined technique, is shown for a fertilized canadian shield lake in the experimental lakes area of northwestern ontario.	1976	814983
specificity of bacterial ribosomes and messenger ribonucleic acids in protein synthesis reactions in vitro.	ribosomes from two gram-negative bacteria translated f2 rna, t4 early mrna, mrna from three gran-negative bacteria, and mrna from six gram-positive bacteria; ribosomes from three gram-positive bacteria translated mrna from the gram-positive strains, but did not translate the other mrnas. ribosomes from the gram-negative bacterium escherichia coli translated synthetic poly(u,g) but ribosomes from the gram-positive bacterium clostridium pasteurianum translated poly(u,g) very poorly, mrna from gram ...	1976	816792
kinetics of dithionite ion utilization and atp hydrolysis for reactions catalyzed by the nitrogenase complex from azotobacter vinelandii.	the kinetics of s2o42-utilization and atp hydrolysis during the nitrogenase-catalyzed h2 evolution and acetylene and nitrogen-reducing reactions were studied using a polarographic technique to monitor-s2o42-concentration. rate constants for both s2o42-utilization and atp hydrolysis were determined as a function of temperature and corresponding activation energies determined. the activation energy for atp hydrolysis differs from that for product formation or s2o42-utilization by 5 kcal/mol above ...	1977	836787
generation of a transmembrane electric potential during respiration by azotobacter vinelandii membrand vesicles.	membrane vesicles isolated from azotobacter vinelandii strain o by lysis of spheroplasts in potassium of sodium phosphate buffer develop a transmembrane electric potential during respiration. the magnitude of this potential was determined by three independent methods: (i) fluorescence of 3,3'-dipropylthiodicarbocyanine and 3,3'-dihexyloxacarbocyanine; (ii) uptake of 86rb+ in the presence of valinomycin; and (iii) uptake of [3h]triphenylmethyl phosphonium. in method (i), the relative fluorescence ...	1977	838687
influence of oxygen on phospholipid production and colony formation in a nitrogen-fixing mutant of azotobacter vinelandii.	colony dimorphism in a conditional nitrogen-fixing mutant of azotobacter vinelandii was directly influenced by fixed nitrogen and oxygen partial pressure and may be related to the production of internal peripheral membrane.	1977	863859
technique for isolating phage for azotobacter vinelandii.	an enrichment technique was developed whereby azotophage could readily be isolated after inoculation of soil sites with azotobacter vinelandii.	1977	869522
[the effect of biocides on the microflora of soils and their degradation. 4. the influence of substances inhibiting the straw decomposition on the nitrogen transformation (author's transl)].	1. active ingredients retarding the carbon-transformation of straw (tcp, thiuram, tbto) also retard the nitrification. their active period depends on the concentration and on the presence of organic matter. high doses of urea can inhibit the nitrification as well. 2. the activity of urease and the ammonification could not be influenced by adequate doses of the tested active ingredients. 3. the species of bacterium azotobacter fixing the nitrogen from the air were inhibited by tcp, urea and d-chl ...	1977	878709
the molecular weight of, and evidence for two types of subunits in, the molybdenum-iron protein of azotobacter vinelandii nitrogenase.	the weight-average molecular weight of the mo-fe protein isolated from azotobacter vinelandii has been determined by sedimentation-equilibrium techniques. in buffer, the value is 245000+/-5000; in 8m-urea, the value is 61000+/-1000. the protein was separated into two components by chromatography on cm-cellulose in 7m-urea, ph 4.5. these components have similar molecular weights but were shown to differ in charge, amino acid content and arginine-containing peptides. it is proposed that the tetra ...	1977	880213
inhibition of azotobacter vinelandii rna polymerase by cibacron blue f3ga.	cibacron blue f3ga is a potent inhibitor of the azotobacter vinelandii dna-directed rna polymerase. addition of 8 micrometer cibacron blue f3ga prior to initiation results in a greater than 90% inhibition of the poly[d(a-t]-directed synthesis of poly[r(a-u)] while addition of the dye during the course of the reaction is without effect on chain elongation. binding of rna polymerase to [3h]poly[d(a-t)] is inhibited by only 15% in the presence of 8 micrometer cibacron blue f3ga. inhibition by cibac ...	1977	885877
complete amino acid sequence of azotoflavin, a flavodoxin from azotobacter vinelandii.		1977	889809
a unique envelope protein in azotobacter vinelandii.		1977	901546
involvement of the cytoplasmic membrane in nitrogen fixation by azotobacter vinelandii.		1977	908330
[microbiological characteristics of lake turali].	the turali lake is a salt-water reservoir. the high salt content of water and ooze determine the microflora of the lake. the total bacterial number is lower in the summer than in the winter when the salt concentration in the lake decreases. the highest number of bacteria and sapropnytes is found in the spring. as a result of the high salt concentration in the water and ooze of the turali lake, the following physiological bacterial groups are partly or entirely absent: azotobacter, clostridium pa ...	1977	909476
a correlation between the dissipation of insecticides and rhizosphere microflora of abelmoschus esculentus (l.) moench.	a study to understand the relationship between the dissipation of aldicarb and disulfoton in the rhizosphere region of bhendi and the microbial population revealed a negative correlation between the fungal and azotobacter population and the residues of both insecticides. however, no definite correlation could be recorded between the populations of bacteria and actinomycetes and the residues of the insecticides.	1977	910573
studies on the rhizosphere and rhizoplane microflora of common-bean and barley.	both broad bean and barley plants stimulated bacteria (total), n-fixing clostridia, azotobacter ammonifiers, and aerobic cellulose-decomposers in their rhizosphere zone. the rhizosphere effects were generally positive until the 8th week of either plant growth. however, the rhizosphere effect differed according to type of plant, growth phase of each single plant, and type of micro-organism under study. the presence of high numbers of micro-organisms in the rhizoplane samples (washed ruptured root ...	1977	910574
transformation of the 4-component pyruvate dehydrogenase complex from azotobacter vinelandii into a 3-component complex.		1977	913582
transformation of nitrogen fixation genes in azotobacter.		1977	921701
intergeneric transfer of genes involved in the rhizobium-legume symbiosis.	genes that seem to be involved in the initial steps of infection of a legume by rhizobium have been transferred, by transformation, to mutant strains of azotobacter vinelandii that are unable to fix nitrogen. these genes code for a surface antigen that binds specifically to a protein from the host plant.	1977	929179
comparison of initial velocity and binding data for allosteric adenosine monophosphate nucleosidase.	adensine monophosphate nucleosidase (amp nucleosidase) from azotobacter vinelandii is composed of six subunits with similar or identical charge and size and has a molecular weight of approximately 320,000. binding studies with tritiated tubercidin 5' -po4 (4-amino-7-(beta-d-ribofuranosyl)pyrrolo[2,3-d]pyrimidine-5' -monophosphate), a competitive inhibitor with respect to the substrate, amp, indicate the presence of three independent, identical binding sites for the substrate analog. the binding ...	1976	931993
letter: chemical probes of nitrogenase. 1. cyclopropene. nitrogenase-catalyzed reduction to propene and cyclopropane.		1976	932370
iron-sulfur clusters and cysteine distribution in a ferredoxin from azotobacter vinelandii.		1976	938514
[the effect of several inhibitors on the hydrogenase activity of azotobacter chroococcum].		1976	940503
a study on the effect of certain phenolic acids and fumarie acid in soil on the development of paddy seedlings and nitrogen-fixing bacteria.		1976	947114
effect of uranyl acetate on microbial fixation of nitrogen in presence of lanthanum sulphate.		1976	947115
use of immunoadsorbent affinity chromatography to purify component i of nitrogenase from extracts of azotobacter vinelandii.		1976	955078