Publications

purification and properties of a four iron-four sulfur protein from a pseudomonas species.	we have isolated an iron-sulfur proteins from a pseudomonas species grown on glucose. this protein has different properties from the two known iron-sulfur proteins isolated from other pseudomonas species: rubredoxin and putidaredoxin. the iron-sulfur protein was purified to homogeneity by deae-cellulose column chromatography and sephadex g-75 gel filtration. the absorption spectrum of the oxidized iron-sulfur protein shows a peak at 283 nm with shoulders at about 290, 320, and 410 nm. the protei ...	1976	956144
repression, derepression and activation of nitrogenase in azotobacter vinelandii.	ammonium ion repressed nitrogenase in cells fixing n2 gas. immunological tests and electrophoresis in various gels show that components i (fe-mo-s protein) was completely repressed by ammonium, whereas component ii (fe-s protein) apoprotein was not markedly affected. component ii from ammonium-grown cells, however, was inactive since it did not cross react with component i to reduce c2h2 to c2h4. the inactive component ii apoprotein is immunologically identical to its active counterpart from cel ...	1976	962720
dihydrodiols from anthracene and phenanthrene.		1976	965633
selective inactivation of nitrogenase in azotobacter vinelandii batch cultures.	when the exhaustion of sucrose or sulfate or the induction of encystment (by incubation in 0.2% beta-hydroxybutyrate) leads to termination of growth in azotobacter vinelandii batch cultures, the nitrogenase levels in the organisms decreased rapidly, whereas glutamate synthase and glutamine synthetase levels remained unaltered. glutamate dehydrogenase activities were low during the whole culture cycle, indicating that ammonia assimilation proceeds via glutamine. toward depletion of sucrose or dur ...	1976	977536
[synthesis of the nitrogen-fixing enzyme system in oligonitrophilic bacteria].	oligonitrophilic bacteria were cultivated on a medium containing only 2.5--10.0 mg/litre of nitrogen compounds. they assimilated elementary nitrogen only after utilization of these nitrogen compounds during growth and formation of nitrogen-fixing enzyme system. their cells grown on a medium containing high concentrations of bound nitrogen did not fix nitrogen during further incubation in the atmosphere of 15n; therefore, the enzymes involved in nitrogen fixation were induced. these organisms are ...	1976	979681
nitrogen fixation by microbial cultures with sodium salt of organic acids as carbon source.	the best source of carbon, when used as the sodium salt of organic acids, is sodium salicylate which shows highest nitrogen fixation and also appreciably large amounts of nitrogen fixed per g carbon consumed. next in order is sodium benzoate, then oxalate. sodium citrate is followed by sowium acetate in the order of decreasing efficiency.	1976	989656
[primary electron donors for azotobacter chroococcum nitrogenase].		1976	994866
chemical modification by trinitrobenzenesulfonate of a lipid and proteins of intracytoplasmic membranes isolated from chromatium vinosum and azotobacter vinelandii.	1. the structure of intracytoplasmic membranes of a photosynthetic bacterium chromatium vinosum and a nitrogen-fixing bacterium azotobacter vinelandii was studied by chemical modification of amino groups of phosphatidylethanolamine and proteins with trinitrobenzenesulfonate. 2. almost all the constituents of intracytoplasmic membranes of c. vinosum were solubilized in a mixture of chloroform, methanol and trichloroacetic acid. one-third of proteins in the intracytoplasmic membranes of c. vinosum ...	1976	999930
stability, induction & localization of nitrate reductase in azotobacter vinelandii.		1976	1010564
flavodoxin: an allosteric inhibitor of amp nucleosidase from azotobacter vinelandii.	flavodoxin, which participates in nitrogen fixation, was found to be a potent allosteric inhibitor of amp nucleosidase [ec 3.2.2.4] from azotobacter vinelandii. it inhibited the enzyme by decreasing its affinity for atp without affecting the maximum velocity. the inhibition constant for flavodoxin was estimated to be 10 mum, which is within the range of physiological concentration in the cells. the concentration of flavodoxin able to alter the activity in vitro suggests that this phenomenon coul ...	1976	1010848
effect of anionic detergents on azotobacter.		1976	1037180
interactions of heterologous nitrogenase components that generate catalytically inactive complexes.	a unique method is described for inhibiting nitrogenase. when clostridium pasteurianum nitrogenase is assayed in the presence of the mo-fe protein of azotobacter vinelandii, all the characteristic activities of nitrogenase are inhibited. c. pasteurianum nitrogenase is unaffected by the fe protein of a. vinelandii. the fe protein, but not the mo-fe protein of c. pasteurianum, inhibits a. vinelandii nitrogenase. both inhibitions described result from the formation of an inactive complex of a. vine ...	1976	1069989
[microbiological study of a saline soil, el salitre].		1976	1071222
polysaccharide production and the possible occurrence of gdp-d-mannose dehydrogenase in azotobacter vinelandii.	during the growth of azotobacter vinelandii in batch culture in burk's 2% glucose medium supplemented with 50 mg edta per litre, water-insoluble capsular polysaccaride material accumulated in cultures prior to the appearance of water-soluble polysaccharide in the culture medium. on isolation, hydrolysis and chromatography, both these polysaccharides were observed to be composed of carbohydrate monomers having the same chromatographic mobilities as glucose, rhamnos, guluronic acid and mannuronic ...	1975	1080387
[effect of the enzyme polynucleotide phosphorylase in a protein-carbohydrate coacervate system].		1975	1089512
transcription of bacteriophage deoxyribonucleic acid. comparison of escherichia coli and azotobacter vinelandii sigma subunits.	the effect of the sigma subunit of rna polymerase on the rate and asymmetry of the in vitro transcription of escherichia coli and azotobacter vinelandii phage dnas has been studied with purified e. coli and a. vinelandii rna polymerases and hybrid enzymes containing the core subunits of one enzyme and sigma from the other. the effect of sigma on the rate of transcription is characteristic of the template and not of the enzyme and depends on ionic strength. the rate of transcription of a. vinelan ...	1975	1091642
transcription of azotobacter phage deoxyribonucleic acid. salt-dependent equilibrium between steps in initiation.	the transcription of azotobacter phage a21 dna by escherichia coli or azotobacter vinelandii rna polymerase differs from that of some other dnas in its inhibition by moderate concentrations of kcl. this characteristic results in an apparent low template activity for this dna as compared with t4 dna under standard assay conditions. from an analysis of the dependence of the various steps in initiation on kcl it is concluded that the effect is exerted on an equilibrium between an inactive polymeras ...	1975	1091643
effect of nitrogen source on carbon metabolism by azotobacter vinelandii op grown in chemostat and batch culture.	azotobacter vinelandii growing under nitrogen-fixing conditions has higher specific activities of isocitric and malic dehydrogenase than do cells growing on nitrate or ammonia. results show that the source of nitrogen has an effect on carbon metabolism.	1975	1097063
temperature and salt effects on the formation of preinitiation complexes between rna polymerase and phage dna.	the influence of temperature and kcl concentration on the formation of rifampicin-resistant preinitiation complexes by holo rna polymerase has been compared for t4 dna and azotobacter phage a21 dna. the sharp transition with respect to temperature between an inactive complex of polymerase and dna and a preinitiation complex reflects an equilibrium between the two complexes, the position of which depends on the temperature and the salt concentration. the transition is shifted to higher temperatur ...	1975	1100115
nitrogenases of klebsiella pneumoniae and azotobacter chroococum. complex formation between the component proteins.	1. sedimentation velocity analyses of mixtures of highly purified component proteins of azotobacter chroococcum are consistent with the formation of a tight 1 : 1 complex in the absence of na2 s2 o4. 1 : 1 complex formation between complementary proteins from a. chroococcum and klebsiella pneumoniae was also observed. the addition of 5 mm na2 s2 o4 weakened the interaction between the a. chroococcum proteins and also the interaction between complementary proteins of a. chroococcum and k. pneumon ...	1975	1101961
nitrogenase in azotobacter chroococcum and klebsiella pneumoniae.		1975	1102367
an assay system for localisation of pyruvate and phosphoenolpyruvate carboxylase activity on polyacrylamide gels and its application to detection of these enzymes in tissue and cell extracts.		1975	1108699
molybdenum and iron as functional consitituents of the enzymes of the nitrate-reducing system of azotobacter chroococcum.	the roles of molybdenum and iron in the enzymes of the assimilatory nitrate-reducing system from azotobacter chroococcum have been investigated. 1. by adding 99 mo-molybdate to a cell culture of a. chrocococcum with nitrate as the nitrogen source, it has been possible to incroporate the radioactive metal into a purified preparation of the enzyme nitrate reductase. 2. when 185 w-tungstate was supplied to a culture medium lacking added molybdate, a 185 w-labelled nitrate reductase preparation with ...	1975	1115563
[a study of the quaternary structure of nitrogenase by the stereophotographic method through an electron microscope].		1975	1117084
studies on the product binding sites of the azotobacter vinelandii ribonucleic acid polymerase.	during chain elongation rna polymerase exists as a ternary dna-enzyme-rna complex in which a discrete length of the nascent rna chain proximal to the 3'-oh terminus will be bound to the product binding site (krakow, j. s., and fronk, e. (1969) j. biol. chem. 244, 5988). we have utilized the poly[d(a-t)]-directed reaction to determine the length of the nascent poly[r(a-u)] protected from attack by pancreatic ribonuclease. following release of the ribonuclease resistant oligo[r(a-u)] from the tern ...	1975	1123330
oxidation of the carcinogens benzo [a] pyrene and benzo [a] anthracene to dihydrodiols by a bacterium.	a mutant strain of beijerinckia, after growth with succinate plus biphenyl, contains an enzyme system that oxidizes benzo [a] pyrene and benzo [a] anthracene to mixtures of vicinal dihydrodiols. the major dihydrodiol formed from benzo [a] pyrene was identified as cis-9, 10-dihydroxy-9, 10-dihydrobenzo [a] pyrene by comparison with a synthetic sample. benzo [a] anthracene was metabolized to four dihydrodiols, the major isomer being cis-1, 2-dihydroxy-1, 2-dihydroxy-1, 2-dihydrobenzo [a] anthracen ...	1975	1145203
cell size as an indicator of changes in intracellular composition of azotobacter vinelandii.	cell size, measured electronically, was correlated to changes in cellular composition, number, and morphology of azotobacter vinelandii op during batch growth. the effect of a changing abiotic environment on these features of the cell is discussed. for this organism exponential growth was unbalanced growth and cell-size change was a sensitive indicator of this growth pattern. cell-size measurements have the potential to give a rapid assessment of intracellular compositional changes.	1975	1148938
continuous non-destructive determination of nitrogenase activity in microbiol cultures.	the dinitrogen fixing enzyme nitrogenase (nitrogen:(acceptor) oxidoreductase)(ec 1.7.99.2) is monitored by its ability to reduce acetylene to ethylene. low, non-inhibitory concentrations of acetylene (approximately 10(-7)mol/litre) are mixed with the gas flow aerating microbiol cultures, and acetylene and ethylene in the effluent gas are determined by gas chromatography. the procedure is safe, simple and carried out in situ without disturbing the growing culture. transient changes in nitrogenase ...	1975	1148948
nitrogenase in synchronized azotobacter vinelandii op.	azotobacter vinelandii op was synchronized by the continuous phased culture technique. the nitrogenase (nitrogen:(acceptor)oxidoreductase)(ec 1.7.99.2) activity of the culture was determined continuously within the fermentor by acetylene reduction. addition of nh4+ in excess of 5 x 10(-3)m to the culture lowered nitrogenase activity immediately. other sources of fixed nitrogen had no immediate effect on nitrogenase activity, but nitrogenase synthesis decreased in the cell cycle following the ...	1975	1148949
interactions among substrates and inhibitors of nitrogenase.	examination of interactions among various substrates and inhibitors reacting with a partially purified nitrogenase from azotobacter vinelandii has shown that: nitrous oxide is competitive with n2; carbon monixide and acetylene are noncompetitive with n2; carbon monoxide, cyanide, and nitrous oxide are noncompetitive with acetylene, whereas n2 is competitive with acetylene; carbon monoxide is noncompetitive with cyanide, whereas azide is competitive with cyanide; acetylene and nitrous oxide incre ...	1975	1150625
influence of pesticides on the presence and activity of nitrogenase in azotobacter vinelandii.		1975	1150985
[growth of azotobacter chroococcum strains on different substrates].	azotobacter chroococcum 34, actively growing on alpha-ketoglutaric acid, and azotobacter chroococcum b and kl, which almost do not assimilate this acid, can grow on the majority of substrates of the tricarboxylic acid cycle and on glucose, with and without nitrogen. the rate of assimilation of alpha-ketoglutaric acid is several times higher in the cells cultivated in the presence of this acid than in the cells grown on other substrates. this difference seems to involve the mechanism of transport ...	1975	1160641
[effect of lyophilization on the nitrogenase activity of azotobacter vinelandii].	the activity of nitrogenase in the cells of azobacter vinelandii grown from lyophilized and non-lyophilized cultures depends on the donor of hydrogen and the concentration of oxygen in the gaseous phase. the lyophilized cells are more sensitive to oxygen (o2 optimum for nitrogen fixation is ca. 1 percent) than the non-lyophilized cells (ca. 5 percent). the determination of acetylene reduction in the course of the culture growth has shown that nitrogen fixation in the lyophilized cells takes plac ...	1975	1160659
dimerization of azotobacter vinelandii flavodoxin (azotoflavin).		1975	1164036
interactions between azotobacter and "phosphobacteria" and their establishment in the rhizosphere as affected by soil fertility.	the effects on plant growth of "bacterial fertilizers" prepared from azotobacter spp. and phosphate-solubilizing bacteria ("phosphobacteria") have been the subject of much controversy. cases where no plant-growth stimulation occurred may often be accounted for by the failure to establish the bacterial inocula in the rhizosphere. three factors that may influence inocula establishment, i.e. soil fertility, manuring, and interactions between azotobacter and "phosphobacteria," were examined in pot e ...	1975	1164695
the pathway of adenylate catabolism in azotobacter vinelandii. evidence for adenosine monophosphate nucleosidase as the regulatory enzyme.	cell-free, dialyzed extracts from azotobacter vinelandii rapidly dephosphorylate [u-14c]atp to labeled adp and amp, which is then degraded to hypoxanthine, the end product of amp catabolism under the experimental conditions which were used. the intermediates of the pathway from atp to hypoxanthine have been identified by thin layer chromatography and quantitated by the 14-c content. the concentrations of intermediates present during the production of hypoxanthine are consistent with amp nucleosi ...	1975	1167548
nitrogenase. vi. acetylene reduction assay: dependence of nitrogen fixation estimates on component ratio and acetylene concentration.	acetylene reduction, an assay for nitrogenase activity (nitrogen:(acceptor) oxidoreductase, ec 1.7.99.2), is dependent on the ratio of the two protein components of nitrogenase as well as on c2h2 concentration. as the component i : component ii ratio (based on activity) is increased, the c2h2 reduction : n2 fixation ratio decreases to a minimum of 3.4 and then increases. the minimum is found at a ratio near 1 : 1. at a component i : component ii ratio of 20 : 1, the c2h2 reduction : n2 fixation ...	1975	1168506
involvement of oxyleghaemoglobin and cytochrome p-450 in an efficient oxidative phosphorylation pathway which supports nitrogen fixation in rhizobium.	cellular atp level, atp/adp ratio and nitrogenase activity rise when oxyleghaemoglobin is added to respiring suspensions of rhizobium japonicum bacteroids from soybean root nodules. increased gaseous o2 tension is much less efficient than oxyleghaemoglobin in stimulation of bacteroid atp production. studies with the inhibitor carbonyl cyanide m-chlorophenylhydrazone show this atp to be generated as a consequence of oxidative phosphorylation. n-phenylimidazole, a specific cytochrome p-450 inhibit ...	1975	1169973
nitrogenase. vii. effect of component ratio, atp and h2 on the distribution of electrons to alternative substrates.	some kinetic properties of purified component i (mo-fe protein) and component ii (fe protein) of nitrogenase (ec 1.7.99.2) from azotobacter vinelandii have been examined. the apparent km values for reducible substrates (0.1 atm for n2, 0.01 atm for acetylene) and dithionite (0.5 mm) are similar for osmotically shocked cell lysates and purified components. however, the atp dependence of acetylene and n2 reduction varies sigmoidally with atp concentration and as a function of the relative and abso ...	1975	1174550
mode of action of the macrolide-type antibiotic, chlorothricin. effect of the antibiotic on the catalytic activity and some structural parameters of pyruvate carboxylases purified from rat and chicken liver.	the macrolide-type antibiotic chlorothricin inhibits pyruvate carboxylases purified from rat liver, chicken liver and azotobacter vinelandii. under standard assay conditions the concentration of chlorothricin required for half-maximal inhibition of oxalacetate synthesis is 0.26 mm (rat liver), 0.12 mm (chicken liver), and 0.5 mm (azobacter vinelandii). inhibition by chlorothricin appears non-competitive in character when measured as a function of the concentration of the substrates of the pyruva ...	1975	1175611
the amino acid sequence of the azotobacter vinelandii flavodoxin.		1975	1180929
stoichiometry, atp/2e values, and energy requirements for reactions catalyzed by nitrogenase from azotobacter vinelandii.	the stoichiometry of the nitrogenase atp-dependent h2 evolution and ecetylene reduction reactions using s2o4(2-) as an electron source was studied by various techniques. for each mole of s2o4(2-) oxidized to 2so3(2-) by the enzyme-catalyzed reactions at 25 degrees and ph 8, 1 mol of h2 (1 mol of ethylene for acetylene reduction) and two protons are produced. under these conditions, 4.5 mol of atp was hydrolyzed to adp and inorganic phosphate for each s2o4(2-) oxidized. atp/s2o4(2-) (atp/2e) valu ...	1975	1182100
study of nitrogenase activity in the mycorrhizal rhizosphere of pine and oak.	no nitrogenase activity was observed in the rhizosphere of pine and oak having mycorrhizal associations. it is concluded that mycorrhiza did not play any role in stimulating the nitrogen fixing system. more work with pine and oak mycorrhiza by isotopic method is suggested.	1975	1190634
molecular weights of nitrogenase components from azotobacter vinelandii.		1975	1191303
the azotobacter flora of some czechoslovakian watercourses.	the occurrence of azotobacter in some szechoslovakian watercourses has been investigated. several strains belonging to a. chroococcum and a. beijerinckii were isolated from 7 out of 18 samples. a. insignis has been isolated from the flowing water of lake machovo at doksy. this is first report of this strictly aquatic azotobacter species in czechoslovakian watercourses. the taxonomy of the genus azotobacter was discussed against the background of the existing knowledge resulting mainly from other ...	1975	1193494
the pyruvate-dehydrogenase complex from azotobacter vinelandii.	the pyruvate dehydrogenase complex from axotobacter vinelandii was isolated in a five-step procedure. the minimum molecular weight of the pure complex is 600,000, as based on an fad content of 1.6 nmol-mg protein-1. the molecular weight is 1.0-1.2 x 10(6), indicating 1 mole of lipoamide dehydrogenase dimer per complex molecule. sodium dodecylsulphate gel electrophoretical patterns show that apart from pyruvate dehydrogenase (mr89,000) and lipoamide dehydrogenase (mrmonomer 56,000) two active tra ...	1975	1204621
[concentration and purification of methane fermented mash by ultrafiltration].		1975	1207526
[effect of mineral fertilizers on the microflora of corn roots].	the paper describes studies of the density of microorganisms grown on meat-peptone agar, fungi, nitrifiers, cellulose degraders, actinomycetes and azotobacter in the soil of the radical area of corn grown in field experiments with various doses and ratios of mineral fertilizers. in the forest-steppe zone (leached chernozem) of the krasnoyarsk region mineral fertilizers activated proliferation of radical microorganisms grown on meat-peptone agar, fungi, nitrifiers and cellulose degraders. the eff ...	1975	1208381
[effect of rotting corn straw on the development of bacteria of the azotobacter group].	the effects of the addition of ground maize straw, nitrogen compounds, ground lucern and water to soils incubated at 30 degrees c in erlenmeyer flasks, on azotobacter chroococcum growth have been studied. the results showed that the highest number of azotobacter in soils treated with different percentage of ground maize straw without addition of nitrogen compounds and with water at 100% field capacity appeared as soon as the 5th day, reaching a maximun on the 20th day when the following numbers ...	1975	1208902
encystment and germination in azotobacter vinelandii.		1975	1212151
[assimilation of alpha-ketoglutaric acid by azotobacter chroococcum].	labelled alpha-ketoglutaric acid was used to study the inability (complete or partial) of some strains of azobacter chroococcum to grow on this substrate. this inability is interpreted by the absence, or a lower rate, of induced synthesis of the transport system specific of alpha-ketoglutaric acid.	1975	1214616
[respiration of oligonitrophilic bacteria].	the respiration rate of 25 studied oligonitrophilous strains belonging to various genera and species of bacteria varied within wide limits depending on their taxonomy, conditions of cultivation, substrates, and other factors. no strict correlation was established between the respiration rate and the activity of nitrogen fixation. one of the typical properties of oligonitrophilous bacteria is a high rate of endogeneous respiration --50% and more of the respiration rate during assimilation of exog ...	1975	1214617
[activity of microorganisms decomposing cholesterol].	the rates of cholesterol decomposition was compared among cell suspensions of different microorganisms. fifty seven cultures were studied: 2 strains of actinomycetes, 23 strains of proactinomycetes, 22 strains of mycobacteria, and 10 strains of bacteria. during four hours of incubation, 11 strains virtually did not decompose cholesterol at all, 10 strains decomposed it by up to 20 per cent, 21 strains by 20 to 70 per cent, and 15 strains by 70 to 100 per cent. the highest activity was displayed ...	1975	1226133
variation in the azotobacter population from several habitats in the botanical garden in poznań.	the abundance of azotobacter was estimated in the rhizosphere of 13 plant species from four habitats in the botanical garden in poznań. the results have shown that within the particular habitats the plant exerts a pronounced influence on the abundance of azotobacter. the morphological differences between azotobacter populations obtained from various habitats confirm the specific effect of the plant on this bacterium.	1975	1227252
respiration-linked proton translocation in azotobacter vinelandii.		1975	1227958
absolute sterochemistry of the dihydroanthracene-cis- and -trans-1,2-diols produced from anthracene by mammals and bacteria.		1975	1239455
radiation studies on azotobacter chroococcum. ii. delayed photo-reactivation.		1975	1242265
radiation studies on azotobacter chroococcum. iii. photoreactivation and mutagenicity.		1975	1242559
radiation studies on azotobacter chroococcum iv. effect of a temporary block of dna replication on excision repair.		1975	1242560
influence of pelleting cabbage seedlings (var. k.k.) with azotobacter chroococcum in the presence of different phosphate fertilizers on their yield.		1975	1242846
scanning electron microscopic studies on the external morphology of azotobacter vinelandii during encystment and germination.	aspects of the external morphology of azotobacter vinelandii cells during encystment and germination processes were observed with scanning electron microscopy. most of the vegetative cells have a smooth surface but some have warty surfaces. the intact cysts have wrinkled surfaces and occasional small heaves. mucoid materials are present on the surface of the cysts. during the encystment process, an extensive peeling-off of coat materials was noted, then the excretion and aggregation of new capsu ...	1975	1243112
availability of soil ammoniacal nitrogen to azotobacter and its effect on nitrogen fixation.		1975	1243715
studies on some environmental factors, affecting denitrification in soil.		1975	1243717
[long lasting effect of organic and inorganic fertilizers in the soil (author's transl)].		1975	1243843
diacridines: bifunctional intercalators. iii. definition of the general site of action.	electron microscopy of hela cells exposed to spermine diacridine shows nucleolar distortions which disappear after several days despite the persistence of the metabolic changes promoted by spermine diacridine. this compound inhibits ribosomal rna synthesis and appears to act independently of any particular phase of the cell cycle. the dna content of the hela cells remains unchanged and the cell distribution is not significantly disturbed from its normal distribution in the various phases of the ...	1976	1247547
the electron transport to nitrogenase in mycobacterium flavum.	1. two ferredoxin-type iron-sulfur proteins have been isolated from mycobacterium flavum 301 grown under nitrogen-fixing, iron-sufficient conditions. no flavodoxin was observed. 2. these ferredoxins are apparently soluble: they were present in the supernatant fraction after disrupting by decompression. only small amounts were present in particulate fractions. 3. the two ferredoxins were separated by chromatography on deae-cellulose, sephadex or electrophoresis. 4. both ferredoxins mediated the t ...	1976	1252086
protozoan feeding and bacterial wall growth.	monod's model is often assumed to describe the kinetics of feeding of a protozoan population on a bacterial population in a chemostat. an earlier study (j. l. jost et al., j. bacteriol., 113, 84 (1973)) of the feeding of tetrahymena pyriformis on either escherichia coli or azotobacter vinelandii found that this model correctly predicted the occurrence of sustained oscillations of population densities but made predictions of minimum bacterial population densities that were much smaller than those ...	1976	1267931
the growth of nitrogen-fixing azotobacter chroococcum in continuous culture under intense aeration.	azotobacter chroococcum (atcc 7493) was grown in continuous culture with intense vortex aeration (stirring rate 1750 rpm) with up to 50% o2 in the gas phase. under these conditions the dissolved o2 generally remained at zero while the cell growth rose to about twice the normally accepted value. the meaning of the term "o2-limitation" in n2-fixing a. chroococcum cultures is critically examined.	1976	1276993
characterization of transcripts expressed from nitrogenase-3 structural genes of azotobacter vinelandii.	five major anfh-hybridizing mrna species accumulated in azobacter vinelandii cells derepressed for nitrogenase-3 (an alternative nitrogenase, which appears to lack mo and v). using anfh-, anfd-, anfg-, anfk-, and orflorf2-specific probes and mutant strains of a. vinelandii these mrna species have been identified as encoding anfhdgkorflorf2 (6.0 kb), anfhdgk (4.3 kb), anfhd (2.6 kb), vnfhorffd (1.3 kb), and vnfh and (or) anfh (1.0 kb). a 0.6-kb mrna species, which hybridized only to the orflorf2- ...	1992	1281443
nucleotide sequences of membrane-bound hydrogenase gene in alcaligenes hydrogenophilus.	the nucleotide sequences of membrane-bound hydrogenase small (hups) and large (hupl) subunit genes of hydrogen bacterium alcaligenes hydrogenophilus were determined. the hups and hupl genes encoded polypeptides of 363 and 619 amino acids, respectively. the hups was located upstream of hupl with 35bp of intergenic region. the consensus ribosome-binding sequences were identified upstream of the start codons of hups and hupl. amino acid sequence of hups is very similar to that of rhodobacter capsul ...	1992	1294332
kinetic and spectroscopic analysis of the inactivating effects of nitric oxide on the individual components of azotobacter vinelandii nitrogenase.	the effects of nitric oxide (no) on the individual components of azotobacter vinelandii nitrogenase have been examined by kinetic and spectroscopic methods. incubation of the fe protein (av2) for 1 h with stoichiometries of 4- and 8-fold molar excesses of no to av2 dimer resulted in a complete loss of activity of av2 in c2h2-reduction assays. the kinetics of inactivation indicated that the minimum stoichiometry of no to av2 required to fully inactivate av2 lies between 1 and 2. the rate of inact ...	1992	1312859
mapping the site(s) of mgatp and mgadp interaction with the nitrogenase of azotobacter vinelandii. lysine 15 of the iron protein plays a major role in mgatp interaction.	nitrogenase binds and hydrolyzes 2mgatp yielding 2mgadp and 2pi for each electron that is transferred from the iron protein to the mofe protein. the iron protein alone binds but does not hydrolyze 2mgatp or 2mgadp and the binding of these nucleotides is competitive. iron protein amino acid sequences all contain a putatitive mononucleotide-binding region similar to a region found in other mononucleotide-binding proteins. to examine the role of this region in mgatp interaction, we have substituted ...	1992	1313018
nmr studies of azotobacter vinelandii and pseudomonas putida seven-iron ferredoxins. direct assignment of beta-cysteinyl carbon nmr resonances and further proton nmr assignments of cysteinyl and aromatic resonances.	ferredoxins are proteins which contain iron and inorganic sulfide and are capable of electron transport. they are found in a wide range of organisms, from anaerobic bacteria, to plants and mammals. although nmr spectroscopy has been used to study ferredoxins since the 1970s, little important structural or biochemical information has resulted from these investigations. the major difficulty has been the effect of the paramagnetic iron-sulfur clusters on the peptide resonances, hindering nuclear ov ...	1992	1314816
the refined crystal structure of pseudomonas putida lipoamide dehydrogenase complexed with nad+ at 2.45 a resolution.	the three-dimensional structure of one of the three lipoamide dehydrogenases occurring in pseudomonas putida, lipdh val, has been determined at 2.45 a resolution. the orthorhombic crystals, grown in the presence of 20 mm nad+, contain 458 residues per asymmetric unit. a crystallographic 2-fold axis generates the dimer which is observed in solution. the final crystallographic r-factor is 21.8% for 18,216 unique reflections and a model consisting of 3,452 protein atoms, 189 solvent molecules and 4 ...	1992	1325638
a reinvestigation of the pre-steady-state atpase activity of the nitrogenase from azotobacter vinelandii.	the pre-steady-state atpase activity of nitrogenase has been reinvestigated. the exceptionally high burst in the hydrolysis of mgatp by the nitrogenase from azotobacter vinelandii communicated by cordewener et al. (1987) [cordewener j., ten asbroek a., wassink h., eady r. r., haaker h. & veeger c. (1987) eur. j. biochem. 162, 265-270] was found to be caused by an apparatus artefact. a second possible artefact in the determination of the stoichiometry of the pre-steady-state atpase activity of ni ...	1992	1325902
e.p.r. and magnetic circular dichroism spectroscopic characterization of bacterioferritin from pseudomonas aeruginosa and azotobacter vinelandii.	the e.p.r. and magnetic circular dichroism (m.c.d.) spectra of bacterioferritin (bfr) extracted from pseudomonas aeruginosa and azotobacter vinelandii have been studied over a wide temperature range down to liquid-helium temperature. the e.p.r. spectra show the presence of low-spin fe3+ haem with g values of 2.86, 2.32, 1.48 (p. aeruginosa) and 2.88, 2.31, 1.46 (a. vinelandii), in both the presence and absence of the bfr core. together with evidence from the porphyrin-to-fe3+ charge-transfer ban ...	1992	1326939
nitrogenase-catalyzed ethane production and co-sensitive hydrogen evolution from mofe proteins having amino acid substitutions in an alpha-subunit femo cofactor-binding domain.	unlike wild type, certain mo-dependent nitrogenases, which are expressed in non-n2-fixing mutant strains of azotobacter vinelandii and have single amino acid substitutions within a region of the mofe protein alpha-subunit proposed to encompass an femo cofactor-binding domain, are able to catalyze the reduction of acetylene by both two and four electrons to yield ethylene and ethane, respectively (scott, d. j., may, h. d., newton, w. e., brigle, k. e., and dean, d. r. (1990) nature 343, 188-190). ...	1992	1328190
iron-sulphur clusters with labile metal ions.	a study has been carried out of the redox-linked metal ion uptake processes of the iron-sulphur cluster [3fe-4s] in the bacterial ferredoxin, fd iii from desulphovibrio africanus using a combination of electron paramagnetic resonance (epr) and low-temperature magnetic circular dichroism (mcd) spectroscopy and direct, unmediated electrochemistry of the fd in a film deposited at a pyrolytic graphite electrode. reduction of the three-iron cluster is required before a divalent metal ion becomes boun ...	1992	1331321
gene dosage analysis in azotobacter vinelandii.	for more than a decade, azotobacter vinelandii has been considered a polyploid bacterium on the basis of physical studies of chromosome size and dna content per cell. however, as described in the present work, many genetic operations can be performed in a. vinelandii without the constraints expected in a polyploid bacterium: (i) reversion of transposon-induced mutations is usually associated with loss of the transposable element; (ii) revertants retaining the transposon always carry secondary tr ...	1992	1334019
correction for creatine interference with the direct indophenol measurement of nh3 in steady-state nitrogenase assays.	creatine was identified as a major source of interference with the direct phenol/hypochlorite colorimetric determination of ammonia in nitrogenase reaction mixtures. a method is described for removing other compounds which inhibit color development and for compensating for the interference produced by creatine. this method avoids time-consuming microdiffusion and also routinely makes available the efficiency of atp hydrolysis coupled to substrate reduction (atp/2e ratio) with n2 as a reducible s ...	1992	1336937
dihydrolipoamide dehydrogenase from haloferax volcanii: gene cloning, complete primary structure, and comparison to other dihydrolipoamide dehydrogenases.	we used the n-terminal amino acid sequence of dihydrolipoamide dehydrogenase from haloferax volcanii, to design and synthesize two oligonucleotide probes that were used to identify and clone a 4.3 kilobase pair (kbp) fragment from mboi restriction endonuclease digestion of hf. volcanii genomic dna. the nucleotide sequence of a 1.5-kbp region of this clone was determined and this revealed an open reading frame that translated into a protein with good homology to dihydrolipoamide dehydrogenase fro ...	1992	1339281
nucleotide-iron-sulfur cluster signal transduction in the nitrogenase iron-protein: the role of asp125.	electron transfer in nitrogenase involves a gating process initiated by mgatp (magnesium adenosine triphosphate) binding to fe-protein. the redox site, an 4fe:4s cluster, is structurally separated from the mgatp binding site. for mgatp hydrolysis to be coupled to electron transfer, a signal transduction mechanism is proposed that is similar to that in guanosine triphosphatase proteins. based on the three-dimensional structure of fe-protein, asp125 is likely to be part of a putative transduction ...	1992	1359643
electroporation and expression of the broad host-range plasmid prk2501 in azotobacter vinelandii.	azotobacter vinelandii cells were transformed via high-voltage electroporation, with the broad host-range plasmid prk2501. the number of transformants was dependent on the applied voltage, capacitance, and recovery procedure after electroporation. for example, log, 4.44 transformants microgram-1 dna were recovered in the a. vinelandii cell suspension electroporated at 1500 v and 25 microf capacitance (time constant 29.0 ms) and recovered on lb agar amended with 0.5 microgram/ml-1 kanamycin (prk2 ...	1990	1366807
identification of acor, a regulatory gene for the expression of genes essential for acetoin catabolism in alcaligenes eutrophus h16.	two hundred thirty-nine base pairs upstream from acoxabc, which encodes the alcaligenes eutrophus h16 structural genes essential for cleavage of acetoin, the 2,004-bp acor gene was identified. acor encodes a protein of 668 amino acids with a molecular mass of 72.9 kda. the amino acid sequence deduced from acor exhibited homologies to the primary structures of transcriptional activators such as nifa of azotobacter vinelandii, ntrc of klebsiella pneumoniae, and hoxa of a. eutrophus. striking simil ...	1992	1378052
abscisic acid and its synthetic analog in relation to growth and nitrogenase activity of azotobacter chroococcum and nostoc muscorum.	the plant hormone abscisic acid as well as its synthetic analog lab 173711 significantly increased the nitrogenase activity of the bacterium azotobacter chroococcum and the cyanobacterium nostoc muscorum. the effect depended on the concentration of the substances (0.001-10 mg/l) and the age of the cultures. the biomass of the organisms was not significantly influenced.	1992	1387101
cloning and molecular analysis of the poly(3-hydroxyalkanoic acid) gene locus of pseudomonas aeruginosa pao1.	from genomic libraries, the polyhydroxyalkanoate gene locus of pseudomonas aeruginosa pao1 was cloned and characterised at the molecular level. two genes coding for polyhydroxyalkanoate synthases, phac1pa and phac2pa, a polyhydroxyalkanoate depolymerase gene, phadpa, and four adjacent open reading frames (orf1, orf2, orf3 and orf4) were identified from the nucleotide sequence. two transcriptional start sites, which were preceded by sequences resembling the escherichia coli consensus sequences fo ...	1992	1396693
femo cofactor synthesis by a nifh mutant with altered mgatp reactivity.	we have characterized a nif- mutant of azotobacter vinelandii, designated uw91 (shah, v. k., davis, l. c., gordon, j. k., orme-johnson, w. h., and brill, w. j. (1973) biochim. biophys. acta 292, 246-255). the specific fe protein mutation giving rise to the nif- phenotype was shown by dna sequencing and site-directed mutagenesis to be the substitution of a conserved alanine at position 157 by a serine. the uw91 fe protein was purified and shown to have a normal [4fe-4s] cluster and normal mgatp b ...	1992	1400428
conformational dynamics and intersubunit energy transfer in wild-type and mutant lipoamide dehydrogenase from azotobacter vinelandii. a multidimensional time-resolved polarized fluorescence study.	time-resolved fluorescence and fluorescence anisotropy data surfaces of flavin adenine dinucleotide bound to lipoamide dehydrogenase from azotobacter vinelandii in 80% glycerol have been obtained by variation of excitation energy and temperature between 203 and 303 k. the fluorescence kinetics of a deletion mutant lacking 14 cooh-terminal amino acids were compared with the wild-type enzyme to study a possible interaction of the cooh-terminal tail with the active site of the enzyme. the flavin ad ...	1992	1420917
evidence of reduced poly-b-hydroxybutyrate biosynthesis in free-living nitrogen-fixing bacteria, azotobacter chroococcum, following acquired resistance to the fungicide captan.	some biological activities of azotobacter chroococcum, strain azcap 1, (spontaneous mutant, captan resistant up to 300 micrograms/ml) were assayed on rm medium with and without the presence of the fungicide. comparisons were also carried out with az. chroococcum sensitive strains azwt, azcan 10 and 14. the hydrolysis of captan, incorporated in agar plates of rm at 100 micrograms/ml, was rapid, since on 4-day plates, no effect was found on the strain azwt, while on freshly prepared ones its growt ...	1992	1439737
formation of poly(hydroxybutyrate-co-hydroxyvalerate) by azotobacter vinelandii uwd.	azotobacter vinelandii uwd formed polyhydroxyalkanoate (pha) copolymers containing beta-hydroxybutyrate and beta-hydroxyvalerate (hv) when grown in a medium containing glucose as the primary c source and valerate (pentanoate) as a precursor. copolymer was not formed when propionate was added to the glucose medium but was formed when heptanoate, nonanoate, or trans-2-pentenoate was present. optimal levels of hv were formed when valerate was added at the time of maximum pha synthesis, although hv ...	1992	1444399
protein control of iron-sulfur cluster redox potentials.	the relationship between the three-dimensional structures of iron-sulfur proteins and the redox potentials of their iron-sulfur clusters is of fundamental importance. we report calculations of the redox potentials of the [fe4s4(s-cys)4]-2/-3 couple in four crystallographically characterized proteins: azotobacter vinelandii ferredoxin i, peptococcus aerogenes ferredoxin, bacillus thermoproteolyticus ferredoxin, and chromatium vinosum high potential iron protein (hipip). our calculations use the " ...	1992	1464583
nucleotide sequence and organization of an h2-uptake gene cluster from rhizobium leguminosarum bv. viciae containing a rubredoxin-like gene and four additional open reading frames.	the nucleotide sequence of a 3.2 kb region following the hydrogenase structural operon (hupslcdef) in the h2-uptake gene cluster from rhizobium leguminosarum by viciae strain 128c53 has been determined. five closely linked genes encoding products of 16.3 (hupg), 30.5 (huph), 8.0 (hupi), 18.4 (hupj) and 38.7 (hupk) kda were identified 166 bp downstream from hupf. transposon insertions into hupg, huph, hupj and hupk suppress the h2-oxidizing capability of the wild-type strain. the amino acid seque ...	1992	1469733
organization and regulation of the bacillus subtilis odhab operon, which encodes two of the subenzymes of the 2-oxoglutarate dehydrogenase complex.	the primary structure of bacillus subtilis 105 kda 2-oxoglutarate dehydrogenase (e10) was deduced from the nucleotide sequence of the odha gene and confirmed by n-terminal sequence analysis. the protein is highly homologous to e1o of azotobacter vinelandii and escherichia coli and of bakers' yeast cells. the 5' end of the odhab mrna was determined and the promoter region for the odhab operon was localized to a 375 bp dna fragment. the cellular concentration of the 4.5 kb odhab transcript was fou ...	1992	1508153
carboxyl-terminal processing may be essential for production of active nife hydrogenase in azotobacter vinelandii.	the nife hydrogenase from azotobacter vinelandii is a membrane-bound alpha beta heterodimer that can oxidize h2 to protons and electrons and thereby provide energy. genes encoding the alpha and beta subunits, hoxg and hoxk respectively, followed by thirteen contiguous accessory genes potentially involved in h2 oxidation, have been previously sequenced. mutations in some of these accessory genes give rise to inactive enzyme containing an alpha subunit with decreased electrophoretic mobility. mass ...	1992	1516712
temperature effects on the mgatp-induced electron transfer between the nitrogenase proteins from azotobacter vinelandii.	the temperature dependence of the pre-steady-state mgatp-dependent electron transfer from the mofe protein to the fe protein of the nitrogenase from azotobacter vinelandii has been investigated between 6 degrees c and 31 degrees c by stopped-flow spectrophotometry. below 14 degrees c, the data are consistent with a model in which interaction of mgatp with nitrogenase is fast and irreversible, and is followed by reversible electron transfer. from the extent and from the rate of the absorbance cha ...	1992	1521527
characterization of two genes (hupd and hupe) required for hydrogenase activity in azotobacter chroococcum.	in azotobacter chroococcum the hydrogenase structural genes (hupsl) cover about 2.8 kb of a 15-kb region associated with hydrogen-uptake (hup) activity. two other genes in this region, hupd and hupe, were located 8.9 kb downstream of hupl and were shown to be essential for hydrogenase activity by insertion mutagenesis. a fragment of dna beginning 3.4 kb downstream of hupl was able to complement the hupe mutant, supporting earlier evidence for a promoter downstream of hupsl. hybridization experim ...	1992	1526470
taxonomic relationship of some members of azotobacteraceae based on their protein profiles.	analysis of protein profiles of the members of azotobacteraceae suggests that the genus azotobacter consists of a heterogeneous group of bacteria, of which azotobacter beijerinekii should possibly be separated to a new genus. azomonas agilis and azomonas macrocytogenes are only 26 percent related to each other.	1992	1527705
nitrogenase structure: where to now?		1992	1529351
crystallographic structure of the nitrogenase iron protein from azotobacter vinelandii.	the nitrogenase enzyme system catalyzes the atp (adenosine triphosphate)-dependent reduction of dinitrogen to ammonia during the process of nitrogen fixation. nitrogenase consists of two proteins: the iron (fe)-protein, which couples hydrolysis of atp to electron transfer, and the molybdenum-iron (mofe)-protein, which contains the dinitrogen binding site. in order to address the role of atp in nitrogen fixation, the crystal structure of the nitrogenase fe-protein from azotobacter vinelandii has ...	1992	1529353
structural models for the metal centers in the nitrogenase molybdenum-iron protein.	structural models for the nitrogenase femo-cofactor and p-clusters are proposed based on crystallographic analysis of the nitrogenase molybdenum-iron (mofe)-protein from azotobacter vinelandii at 2.7 angstrom resolution. each center consists of two bridged clusters; the femo-cofactor has 4fe:3s and 1mo:3fe:3s clusters bridged by three non-protein ligands, and the p-clusters contain two 4fe:4s clusters bridged by two cysteine thiol ligands. six of the seven fe sites in the femo-cofactor appear to ...	1992	1529354