Publications

physiological adaptations in response to environmental stress during an n(2)-fixing anabaena bloom.	anabaena spiroides has the ability to maintain intense biomass production for extensive periods in the epilimnion of a small eutrophic lake characterized by conditions shown to cause photooxidative death in a number of other phytoplankton. by the enhancement of carotenoid synthesis chlorophyll a was protected from photooxidation and prevented from catalyzing other photooxidative reactions within the cells. by temporally separating co(2) and n(2) fixation, maximum utilization of photosyntheticall ...	1980	16345637
identification of blue-green algal nitrogen fixation genes by using heterologous dna hybridization probes.	in the filamentous blue-green alga anabaena 7120, aerobic nitrogen fixation is linked to the differentiation of specialized cells called heterocysts. in order to study control of heterocyst development and nitrogen fixation in anabaena, we have used cloned fragments of the klebsiella pneumoniae nitrogen fixation (nif) genes as probes in dna.dna hybridizations with restriction endonuclease fragments of anabaena dna. using this technique, we were able to identify and clone anabaena nif genes, demo ...	1980	16592748
nucleotide sequence of a cyanobacterial nifh gene coding for nitrogenase reductase.	the nucleotide sequence of nifh, the structural gene for nitrogenase reductase (component ii or fe protein of nitrogenase) from the cyanobacterium anabaena 7120 has been determined. also reported are 194 bases of the 5'-flanking sequence and 170 bases of the 3'-flanking sequence. the predicted amino acid sequence was compared with that determined for the complete nitrogenase reductase of clostridium pasteurianum and the cysteine-containing peptides of the protein from azotobacter vinelandii. ami ...	1980	16592916
the isolation and characterization of a sequence-specific endonuclease from anabaena subcylindrica.	an endonuclease, asui, was isolated from extracts of anabaena subcylindrica on the basis of gel-electrophoretic analysis of digests of bacteriophage-lambda dna with the paritally purified extracts. the enzyme requires mg2+, but no other cofactors. endonuclease asui recognizes the interrupted tetranucleotide sequence: (formula: see tex), and breaks the phosphodiester bonds indicated by the arrows to leave single-stranded trinucleotide projections at the 5'-termini of the dna fragments.	1980	6246880
the nucleotide sequences recognized by endonucleases avai and avaii from anabaena variabilis.	determination of the 5'-terminal sequences flanking all the individual cleavage sites for endonuclease avai in bacteriophage-lambda dna has shown that this enzyme recognizes the hexanucleotide sequences: (formula: see text), this sequence is cut as shown by the arrows to give single-stranded 5'-tetranucleotide protrusions (cohesive ends). endonucleases smai, xhoi and xmai recognize different symmetrical subsets of this sequence and provide independent evidence for the occurrence of these subsets ...	1980	6246881
novel mutant of anabaena sp. strain ca which growns on n2 but not on combined nitrogen.	a mutant has been isolated from anabaena sp. strain ca by treatment with n-methyl-n'-nitro-n-nitrosoguanidine, which has the unusual phenotypic characteristic of growth only under n2-fixing conditions. growth of the mutant was completely inhibited by no3- or nh4+ at concentrations routinely used for growth of the wild type, and sensitivity to nh4+ was especially pronounced. the inhibitory effect of nh4+ could not be overcome by glutamine, glutamate, or casein hydrolysate. ammonia had no immediat ...	1980	6106012
regulation of glutamine synthetase in the blue-green alga anabaena flos-aquae.		1980	6107080
regulation of glutamine synthetase in the blue-green alga anabaena l-31.	in n2-grown cultures of anabaena l-31, in which protein synthesis was prevented by chloramphenicol, presence of nh+4 caused a drastic decrease of glutamine synthetase (l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2) activity indicating nh+4-mediated inactivation or degradation of the enzyme. the half-life of glutamine synthetase was more than 24 h, whereas that of nitrogenase (reduced ferredoxin:dinitrogen oxidoreductase (atp-hydrolysing), ec 1.18.2.1) was less than 4 h, suggesting that gl ...	1980	6108785
approach to recognition of regulatory mutants of cyanobacteria.	antimetabolite analogs of essential amino acids are useful as selective agents for isolation of regulatory mutants of cyanobacteria, although we observed striking microbiological differences from other widely used eubacterial systems. regulatory mutants shown to overproduce and excrete tryptophan, phenylalanine, tyrosine, methionine, or arginine were isolated from four cyanobacteria: anabaena sp. 29151, synechococcus sp. 602, synechococcus sp. an tx20, and synechocystis sp. 29108. surprisingly, ...	1980	6782084
strategies of response to copper, cadmium, and lead by a blue-green and a green alga.	the toxic metal ions cu2+, cd2+, and pb2+ inhibited growth of the green alga ankistrodesmus braunii and the blue-green alga (cyanobacterium) anabaena, strain 7120. some concentrations of cu lysed anabaena 7120 at early, but not late, stages of growth. the other metals inhibited growth without causing lysis. adding the chelating agent nitrilotriacetic acid (nta) did not reduce, and in some cases increased, metal toxicity to anabaena 7120. this suggests that these metals do not act on this alga on ...	1980	6783279
[composition of the folded chromosome from anabaena variabilis].	a "heavy" nucleoid (folded chromosome) from a. variabilis has been isolated in preparative amounts. the composition of the folded chromosome and that of a more simple dna--protein complex isolated from the "heavy" nucleoid of a. variabilis by chromatography on a column with methylated albumin (mak) were studied. it was shown that the "heavy" nucleoids contain total cell dna in a complex with the definite membrane fragment, which can be discovered by a large number of membrane proteins, phospholi ...	1980	6788095
biochemical studies on sporulation in blue-green algae. iii. effect of amino acids on glycogen accumulation.	the effect of 21 amino acids was studied on glycogen accumulation during sporulation in the blue-green alga anabaena sp. all the amino acids enhanced the initial level of glycogen on the 4th day. the maximum amount of glycogen, on the 20th day, was noticed from l-methionine, l-tyrosine, glycine, and l-histidine supplemented cultures. others like l-serine, l-valine, l-asparagine, dl-alanine, l-glutamic acid, l-phenylalanine, l-aspartic acid, l-arginine, and dl-lysine come next in the order. on th ...	1980	6784355
[comparative study of the oxygen reduction in photosystem ii of the cyanobacteria, anacystis nidulans and anabaena variabilis].	oxygen reduction in the photosystem ii (ps ii) of thylakoid membranes from the cyanobacteria anacystis nidulans and anabaena variabilis was studied in the system simo + dcmu in whose presence competitive electron transport to simo and o2 in possible. the reagents of the mehler reaction were used; these reagents activate oxygen uptake by interacting with the reduced forms of oxygen (malonate and oxalate with o2; glyoxylate and catalase + ethanol with h2o2). the use of the reagents as shown that t ...	1980	6782430
structural characterization of the cyanophycin granule polypeptide of anabaena cylindrica by circular dichroism and raman spectroscopy.	the cyanophycin granule polypeptide, or multi-l-arginyl-poly(l-aspartic acid), from the filamentous cyanobacterium anabaena cylindrica has been examined by circular dichroism and laser raman spectroscopy. the polypeptide exhibits defined secondary structure in acidic solution, but not in alkaline medium. raman spectra show the structure of the insoluble (storage?) form of the polypeptide is similar but not identical to that of the acid soluble form. analysis of the cd spectra suggests that beta- ...	1980	6783080
[photosynthetic oxygen evolution and co2 photoassimilation by cyanobacteria that form water-bloom spots in a sulfur spring with a high sulfide content].	cyanobacteria belonging mainly to the genera anabaena and oscillatoria were isolated from water-bloom spots of a sulfur spring in staraya matsesta. their suspensions evolved o2 at a rate of 6--8 nm/min per 1 mg of dry cell weight at an intensity of solar radiation being 60--75 mv/cm2 per 1 sec. the cells were also capable of co2 photoassimilation in the presence of solfide at a rate of 10(-4) mg c per mg per hour. dcmu at a concentration of 10(-5) m completely inhibited o2 evolution and inhibite ...	1980	6446661
structure and composition of cyanophycin granules in the cyanobacterium aphanocapsa 6308.	cyanophycin granules in the unicellular cyanobacterium aphanocapsa 6308 were examined with the electron microscope in both thin section and by freeze-fracture techniques. purified granules were examined with the electron microscope, by arginine determinations, by chromatography, and by elemental analysis. they are similar in ultrastructure and composition to those isolated from the nitrogen-fixing cyanobacterium anabaena cylindrica, consisting of equal molar quantities of l-arginine and l-aspart ...	1980	6767696
control of phycobiliprotein proteolysis and heterocyst differentiation in anabaena.	phycobiliprotein degradation can be initiated in cultures of the cyanobacterium anabaena by removal of combined nitrogen from the medium. certain strains of anabaena differentiate cells specialized for aerobic nitrogen fixation (heterocysts) under such conditions. we describe here a procedure for the preparation of extracts from heterocysts or vegetative cells that contain an activity capable of degrading only the phycobiliproteins in a mixture of soluble anabaena proteins in vitro. this activit ...	1980	6767709
three-dimensional structures of c-phycocyanin and b-phycoerythrin at 5-a resolution.	single crystal x-ray diffraction studies are proceeding on two phycobiliproteins: c-phycocyanin from anabaena variabilis and b-phycoerythrin from porphyridium cruentum. c-phycocyanin consists of six alpha and six beta subunits. a three-dimensional x-ray diffraction study of this light-harvesting protein (p6(3); a = b = 154.1 a, c = 40.1 a) at 5-a resolution shows that the molecule is 110 a in diameter, 40 a thick, with a 20-a diameter central channel. it can be divided into three separate domain ...	1980	6768730
developmental mutants of anabaena doliolum defective in repair of uv-damage.		1980	6768968
protein-transients during heterocyst differentiation in anabaena circularis and cylindrospermum sp.	the programme of protein synthesis accompanying cellular differentiation to the heterocyst following transfer of the blue-green algae anabaena circularis and cylindrospermum sp. (cbsc 1755) from ammonia-enriched medium to nitorgen-free medium was determined by polyacrylamide gel electrophoresis of whole proteins during successive intervals of differentiation. besides this, total proteins and soluble amino acids were determined quantitatively. at least 4 sets of proteins can be distinguished on t ...	1980	6769261
biosynthesis of 5-aminolevulinate from glutamate in anabaena variabilis.	anabaena variabilis filaments excrete 5-aminolevulinate into the medium when incubated in the presence of levulinic acid, a competitive inhibitor of the 5-aminolevulinate utilizing enzyme, 5-aminolevulinate dehydratase (5-aminolevulinate hydro-lyase, ec 4.2.1.24). although 5-aminolevulinate accumulation is independent of an external supply of substrate, the accumulating 5-aminolevulinate can be readily labeled by [14c]glutamate or alpha-[14c]ketoglutarate. glycine and succinate, substrates of th ...	1980	6769487
tungsten-induced inactivation of molybdoenzymes in anabaena.	the effect of tungsten on growth and activity of two molybdoenzymes has been studied in a nitrogen-fixing heterocystous cyanobacterium, anabaena. sodium tungstate inhibited growth and inactivated nitrogenase and nitrate reductase. the activity of both enzymes was restored by the addition of molybdenum. tungstate treatment caused increase in heterocyst frequency both in no3- medium and in medium free of combined nitrogen. these results suggest that tungstate treatment inactivates the molybdoenzym ...	1980	6769488
interactions between the solvent acetone and the pyrethroid insecticide permethrin on activities of the blue-green alga anabaena.		1980	6769524
kinetic properties of ribulose 1,5-bisphosphate carboxylase/oxygenase from anabaena variabilis.		1980	6772105
adenosylcobalamin-dependent ribonucleotide reductase from the blue-green alga, anabaena sp. purification and partial characterization.	the ribonucleotide reductase from anabaena 7119 has been purified approximately 60- to 80-fold by conventional techniques and adsorption to the affinity medium, matrix gel red a. the enzyme from anabaena resembles the adenosylcobalamin-dependent reductase from lactobacillus leichmannii, in that it is a small molecule (molecular weight 72,000) with no subunit structure as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. unlike its prototype, the anabaena reductase is absol ...	1980	6772640
[regulation of the differentiation processes in an anabaena cylindrica culture].	the maximal frequency of heterocysts in the culture of anabaena cylindrica grown in a nitrogen-free medium was found after 6 days of growth (6%); the number of heterocysts decreased to 1.8% with aging. the quantity of heterocysts in the culture decreased (they could even disappear completely) in the presence of ammonium salts as the source of nitrogen. the index of the shape (the length-to-width ratio of cells, %) decreased under these conditions though it increased in the other variants of the ...	1980	6772929
heterocyst differentiation and tryptophan metabolism in the chanobacterium anabaena sp. ca.		1980	6773477
temperature shift-induced responses in lipids in the blue-green alga, anabaena variabilis: the central role of diacylmonogalactosylglycerol in thermo-adaptation.	changes in fatty acids and lipid molecular species after shift of growth temperature were studied in the blue-green alga, anabaena variabilis. in the first 10 h after a temperature shift from 38 to 22 degrees c, lipid synthesis was markedly suppressed. during this period most of the palmitic acid of the diacylmonogalactosylglycerol was desaturated to palmitoleic acid. thereafter lipid synthesis resumed, and, in the following hours, the relative contents of palmitic and palmitoleic acids were alm ...	1980	6773583
[interaction of cyanobacteria cells with methyl viologen].	oxygen absorption instead of its evolution is induced in cell suspensions of the cyanobacteria anacystis nidulans and anabaena variabilis in the presence of methylviologen, an autoxidable electron acceptor, and triphenyltetrazolium chloride which is irreversibly reduced in the cells. the process occurs without addition of exogenous donors and does not depend on dcmu. dichlorophenolindophenol and ascorbate do not stimulate the absorption. the blue colour of reduced methylviologen was not observed ...	1980	6774211
biochemical studies on sporulation in blue-green algae. ii. factors affecting glycogen accumulation.	inorganic nitrogens sources like nitrate, nitrite enhanced sporulation and glycogen accumulation in anabaena sp. but ammonium chloride neither influenced sporulation nor glycogen accumulation. acetate and citrate also stimulated early sporulation and glycogen level was higher over nitrogen free control. nitrogen and carbon sources in combination proved to be useful in inducing early sporulation and increased content of glycogen. phosphate and calcium also affected glycogen accumulation significa ...	1980	6776695
effect of certain herbicides on survival, growth, and nitrogen fixation of blue-green alga anabaena doliolum bharadwaja.	growth and fixation of nitrogen were retarded in anabaena doliolum when grown on elemental nitrogen in presence of four different herbicides. the alga was found to be intolerant to these chemicals under nitrogen fixing conditions even in low concentrations. an inhibition of photosynthesis has been regarded as the main basis of herbicidal activity besides other interactions.	1980	6776696
[reactions of cyanobacteria to certain heavy metals].	the effect of zinc and cobalt chlorides on cellular growth, n2 fixation, photosynthesis and changes in the content of na+ and k+ ions in cells was studied with the blue-green alga (cyanobacterium) anabaena spheroides. the cells were most susceptible to the action of cobalt ions at the beginning of the logarithmic growth phase, and least sensitive by the end of the phase. cobalt ions were more toxic than zinc ions. the salts of heavy metals inhibited active transport of ions into the algal cells.	1980	6777649
components of the proton electrochemical potential gradient in anabaena variabilis.		1980	6780388
potassium ion transport and electrogenesis in anabaena variabilis.		1980	6780389
discrimination between rubidium and potassium ions in anabaena variabilis.		1980	6780390
[molecular nitrogen fixation in the waters of eutrophic and polyhuic lakes of the estonian ssr].	a modified acetylene technique was used to assay the rate of molecular nitrogen fixation in estonian lakes containing methane in the hypolimnion. methods were elaborated to eliminate ethylene cooxidation by methane oxidizing bacteria. methane oxidation and nitrogen fixation were found in a narrow microaerobic zone in lakes with the stratification of temperature in the water mass; these biochemical processes occurred when the content of dissolved oxygen varied within the range of 0.1 to 0.8 mg o2 ...	1980	7412622
regulation of nitrate reductase levels in the cyanobacteria anacystis nidulans, anabaena sp. strain 7119, and nostoc sp. strain 6719.	the effect of the nitrogen source on the cellular activity of ferredoxin-nitrate reductase in different cyanobacteria was examined. in the unicellular species anacystis nidulans, nitrate reductase was repressed in the presence of ammonium but de novo enzyme synthesis took place in media containing either nitrate or not nitrogen source, indicating that nitrate was not required as an obligate inducer. nitrate reductase in a. nidulans was freed from ammonium repression by l-methionine-d,l-sulfoximi ...	1981	6780511
energy transfer from phycobiliproteins to photosystem i in vegetative cells and heterocysts of anabaena variabilis.	the presence of phycobilins in heterocysts of anabaena variabilis is established on the basis of absorption and fluorescence spectroscopy. at 77 k heterocysts exhibit fluorescence emission bands at 645 and 661 nm indicative of phycocyanin and allophycocyanin, respectively. both allophycocyanin levels and fluorescence emission at 695 nm were low in heterocysts relative to whole filaments. in situ fluorescence microscopy confirmed the presence of phycobilins in individual heterocysts, but the pigm ...	1981	6781539
molecular heterogeneity of ferredoxin:nadp+ oxidoreductase from the cyanobacterium anabaena cylindrica.	the enzyme ferredoxin:nadp+ oxidoreductase (ec 1.18.1.2) from whole filaments of anabaena cylindrica can be separated into four major fractions by chromatography on phosphocellulose; chromatography using ferredoxin-sepharose 4b proved to be less satisfactory in separating the fractions. the purified fractions, designated 1, 2, 3 and 4, all showed diaphorase and ferredoxin-dependent cytochrome c reductase activity. the major fractions present were 2 and 3 which were each obtained in an electropho ...	1981	6783100
correspondence of the larger subunit of the mofe-protein in clostridial nitrogenase to the nif d gene products of other n2-fixing organisms.	the amino(n)-terminal sequence of the larger subunit (alpha) of the mofe-protein from clostridium pasteurianum was determined up to 179 amino acid residues by analyses of brcn and tryptic peptides of the original subunit. apparent similarities exist among the sequence of the clostridial alpha-subunit, that of the smaller subunit (beta) of the azotobacter vinelandii mofe protein, and those predicted from the nucleotide sequences of nif d genes in klebsiella pneumoniae and anabaena 7120. in compar ...	1981	7026551
biological nitrogen fixation: primary structure of the klebsiella pneumoniae nifh and nifd genes.	a dna fragment carrying the klebsiella pneumoniae nifk, d, and h genes was isolated from the nif- strain unf841 (tn5::nifk) by molecular cloning into the escherichia coli plasmid pbr325. the nucleotide sequences of both the nifh gene, which encodes the fe protein of the nitrogenase enzyme complex, and 622 nucleotides of the nifd gene, which encodes the alpha-subunit of the mo-fe protein, were determined by direct dna sequencing by both the chemical and chain termination methods. a comparison of ...	1981	6809876
isolated heterocysts of anabaena variabilis synthesize envelope polysaccharide.	isolated heterocysts, incubated for 1 h at 30 degrees c [14c]mannose, synthesize [14c]arabinose and [14c]glucose, and incorporate the three 14c-labeled sugars into their envelopes with glycosidic linkages characteristic of their envelope polysaccharide. in extracts of metabolic intermediates with hot 80% methanol, [14c]mannose is associated with the nucleotide gdp and [14c]glucose and [14c]arabinose with udp. chloroform/methanolic extracts of the heterocysts contain phosphoglycolipids in which 1 ...	1981	6786363
nitrogenase activity and membrane electrogenesis in the cyanobacterium anabaena variabilis kütz.	relationships between nitrogenase activity and individual components of the proton electrochemical potential gradient (delta microh+) in anabaena variabilis have been investigated. the ionophore nigericin was found to collapse delta ph in favour of the membrane potential (delta psi); hyperpolarization of delta psi was correlated with an increase in nitrogenase activity. a positive relationship between nitrogenase activity and membrane potential was also observed using the ionophore valinomycin a ...	1981	6786885
metabolism of sulfur compounds by whole filaments and heterocysts of anabaena variabilis.	filaments of the heterocyst-forming cyanobacterium anabaena variabilis reproduced 35so4(2)-, incorporating 35s into cysteine, methionine, glutathione, sulfolipid, and several unidentified metabolites. the majority of the incorporated label accumulated in reduced glutathione. heterocysts isolated from labeled filaments contained the same major labeled products. isolated, metabolically active heterocysts were unable to reduce 35so4(2)-, but were able to incorporate 35s2- into cysteine and glutathi ...	1981	6787010
fructose uptake and influence on growth of and nitrogen fixation by anabaena variabilis.	fructose is specifically taken up by nitrogen-fixing cultures of anabaena variabilis in the light and lowers the doubling time from 24 to 8 h. the kinetics for both fructose-dependent growth and fructose uptake are exponential. the apparent km for fructose uptake in n2-fixing cultures is 160 microm for cells not previously exposed to fructose and 50 microm in cells adapted to fructose. picomolar amounts of [14c]fructose are scavenged from the medium and accumulate in filaments. heterocysts of fr ...	1981	6787026
hemagglutination method for detection of freshwater cyanobacteria (blue-green algae) toxins.	strains of the freshwater cyanobacteria (blue-green algae) anabaena flosaquae and microcystis aeruginosa produced toxins that caused intermittent but repeated cases of livestock, waterfowl, and other animal deaths. they also caused illness, especially gastrointestinal, in humans. the most common group of toxins produced by these two species were peptide toxins termed microcystin, m. aeruginosa type c, and anatoxin-c. a method was found to detect the toxins which utilizes their ability to cause a ...	1981	6787984
heterotrophic growth and nitrogen fixation in the filamentous blue-green alga anabaena sp.	experiments were conducted to study the effect of five different organic substrates viz. lactose, fructose, mannose, xylose and sodium acetate on the heterotrophic growth characteristics with emphasis on growth, pigment composition, heterocyst frequency and nitrogen fixation of anabaena sp. under light and dark conditions. lactose was found to be the best carbon source to support the heterotrophic growth of the alga. phycoerythrin pigments were synthesized in photoheterotrophic cultures but pigm ...	1981	6801875
characterization of the transport of potassium ions in the cyanobacterium anabaena variabilis kütz.	interrelationships between potassium-ion transport and transplasmalemma electrical-potential difference (delta psi m) have been investigated in anabaena variabilis (atcc 29413) by measuring k+ translocation and membrane potential in parallel. at ph 7.0, 5 mmol . dm-3 external k+, there was a thirtyfold accumulation of k+. the k+ equilibrium potential was lower (more negative) than the measured membrane potential by up to 20 mv, (delta psi k+ = -90 mv; delta psi m = -70 mv to -75 mv, respectively ...	1981	6788551
a phytohaemahglutinin from the azolla-anabaena symbiosis.		1981	6789831
isolation and characterization of thioredoxin from the cyanobacterium, anabaena sp.	thioredoxin from anabaena sp. has been purified 800-fold with an assay based on the reduction of insulin disulfides by nadph and the heterologous calf thymus thioredoxin reductase. the final material was homogeneous on polyacrylamide gel electrophoresis and had a molecular weight of 12,000; the nh2-terminal residue was serine and the cooh-terminal was leucine. anabaena thioredoxin-(sh)2 is a hydrogen donor for the adenosylcobalamin-dependent anabaena ribonucleotide reductase and is equally activ ...	1981	6790538
response of a wild type and a non-nitrogen-fixing mutant of anabaena doliolum towards different amino acids.	the effects of various amino acids on growth and heterocyst differentiation have been studied on wild type and a heterocystous, non-nitrogen-fixing (het+ nif-) mutant of anabaena doliolum. glutamine, arginine and asparagine showed maximum stimulation of growth. serine, proline and alanine elicited slight stimulation of growth of wild type but failed to show any stimulatory effect on mutant strain. valine, glutamic acid, iso-leucine and leucine at a concentration of as low as 0.1 mm were inhibito ...	1981	6792797
the amino acid sequence of the beta subunit of allophycocyanin.	the complete amino acid sequence of the beta subunit of anabaena variabilis allophycocyanin is: h2n-ala-gln-asp-ala-ile-thr-ala-val-ile-asn-ser-ala-asp-val-gln-gly-lys-tyr-leu-asp-thr-ala-ala-leu-glu-lys-leu-lys-ala-tyr-phe-ser-thr-gly-glu-leu-arg-val-arg-ala-ala-thr-thr-ile-ser-ala-asn-ala-ala-ala-ile-val-lys-glu-ala-val-ala-lys-ser-leu-leu-tyr-ser-asp-ile-thr-arg-pro-gly-gly-asn-met-tyr-thr-thr-arg-arg-tyr-ala-ala-cys-ile-arg-asp-leu-asp-tyr-tyr-leu-arg-tyr-ala-thr-tyr-ala-met-leu-ala-gly-asp- ...	1981	6793571
effect of rifampicin on the heterocyst pattern in anabaena arm 314.	alteration in the pattern of heterocysts is observed when suspending ammonia-grown filaments of anabaena arm 314 in a medium devoid of combined nitrogen source but supplemented with rifampicin. paired as well as strings of 3--9 heterocysts were noticed. the electrophoretic protein pattern of non-heterocystous, heterocystous and multiple heterocystous filaments revealed that multiple heterocystous filaments are characterized by the presence of two additional protein transients. it is speculated t ...	1981	6794228
effect of growth-promoting chemicals on growth, nitrogen fixation and heterocyst frequency of a blue-green alga.	iaa was found to stimulate growth, nitrogen fixation and pigment synthesis in anabaena doliolum in all concentrations tested. heterocyst frequency was stimulated up to a concentration of 50 ppm iaa. naa stimulated growth and nitrogen fixation up to 10 ppm. ga promoted growth, pigment synthesis, heterocyst frequency and nitrogen fixation only up to a concentration of 2 ppm. kinetin promoted growth up to 100 ppm and synthesis of pigments, while nitrogen fixation was stimulated up to 5 ppm.	1981	6794229
hydrogen uptake by the nitrogen-starved cyanobacterium anabaena cylindrica.		1981	6795997
cyanobacterial phycobilisomes. phycocyanin assembly in the rod substructures of anabaena variabilis phycobilisomes.	phycocyanin complexes with "linker" polypeptides (lundell, d. j., williams, r. c., and glazer, a. n. (1981) j. biol. chem. 256, 3580-3592) of 27 and 32.5 kilodaltons have been isolated from dissociated anabaena variabilis phycobilisomes. in 0.05 m phosphate at ph 7.0, these "trimeric" complexes have the molar composition (alpha beta)3 . 27,000 and (alpha beta)3 . 32,500, where alpha and beta are the subunits of phycocyanin and 27,000 and 32,500 denote single copies of the linker polypeptides. th ...	1981	6796581
heterocyst differentiation and cell division in the cyanobacterium anabaena cylindrica: effect of high light intensity.	heterocyst differentiation in the cyanobacterium anabaena cylindrica is initiated by the removal of fixed nitrogen from the medium. these specialized cells occur singly at regular intervals within filaments of vegetative cells. incubation of cultures for periods of up to 12 h immediately prior to or following removal of fixed nitrogen, at a light intensity (500 mi einsteins cm-2 s-1) approximately 10-fold higher than that required for optimum growth, resulted in the differentiation of pairs of a ...	1981	6796596
occurrence and localization of two distinct hydrogenases in the heterocystous cyanobacterium anabaena sp. strain 7120.	two distinct types of hydrogenase occur in anabaena 7120 and are distinguishable in whole filaments by the application of selective assay methods. a reversible hydrogenase occurs both in heterocysts and vegetative cells and can be selectively assayed by measuring h2 evolution from reduced methyl viologen. activities in aerobically grown filaments were low but could be increased by 2 to 3 orders of magnitude by growing cells microaerobically. the presence of the reversible hydrogenase was indepen ...	1981	6783614
comparative characterization of two distinct hydrogenases from anabaena sp. strain 7120.	two distinct hydrogenases, hereafter referred to as "uptake" and "reversible" hydrogenase, were extracted from anabaena sp. strain 7120 and partially purified. the properties of the two enzymes were compared in cell-free extracts. uptake hydrogenase was largely particulate, and although membrane bound, it could catalyze an oxyhydrogen reaction. particulate and solubilized uptake hydrogenase could catalyze h2 uptake with a variety of artificial electron acceptors which had midpoint potentials abo ...	1981	6783615
absorption spectrum of allophycocyanin isolated from anabaena cylindrica: variation of the absorption spectrum induced by changes of the physico-chemical environment.	the absorption spectrum of allophycocyanin of anabaena cylindrica was studied. the extinctions of the main absorption bands (650 and 620 nm) varied depending on the protein concentration, ionic strength, and ph. at higher protein concentrations or higher ionic strength, the 650 nm band became stronger and the 620 nm band became weaker. at ph values lower than 6.0, reverse changes occurred in association with protein dissociation into monomer. similar spectral variation was also induced by sugars ...	1981	6783641
[conditions for cyanobacteria l-transformation].	anabaena variabilis and chlorogloea fritschii can easily form l-like colonies that are characterized by their appearance and the morphology of component structures. the colonies consist of morphological elements typical of the l-variants of chemoheterotrophic bacteria: filaments, "grains", ring-shaped cells, etc. data are presented pertinent to the functional activity of the photosynthetic apparatus of these organisms subjected to l-transformation.	1981	6783818
effect of acetone on the toxicity of atrazine towards photosynthesis in anabaena.	the effect of acetone on the toxicity of atrazine towards photosynthesis in the blue-green algae anabaena inaequalis, a. variabilis and a. cylindrica was investigated. the order of sensitivity to atrazine was a. inaequalis greater than a. variabilis greater than a. cylindrica. acetone and atrazine interacted additively, antagonistically, and synergistically, depending upon the concentrations of acetone and atrazine used. the ec50 of atrazine towards photosynthesis was dependent upon the type of ...	1981	6782150
in vivo regulation of glutamine synthetase by ammonium in the cyanobacterium anabaena l-31.		1981	6111293
a cloned cyanobacterial gene for glutamine synthetase functions in escherichia coli, but the enzyme is not adenylylated.	the coding sequence for anabaena 7120 glutamine synthetase [l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.1] are shown to be contained within a 7.5-kilobase-pair (kbp) hindiii fragment that has been cloned by plaque hybridization. the hybridization probe for the cyanobacterial gene was a recombinant plasmid containing the glna gene from escherichia coli k-12. evidence that the cloned anabaena fragment contains the glna gene includes complementation of a glna deletion mutant of e. coli and i ...	1981	6115380
regulatory isozymes of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase in the cyanobacterium anabaena sp. strain atcc 29151.	two regulatory isozymes of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase from the cyanobacterium anabaena sp. strain atcc 29151 were separated via gel filtration. one isozyme (mr = 205,000) was sensitive to phenylalanine inhibition, and the other (mr = 60,000) was sensitive to tyrosine inhibition. the tyrosine-sensitive isozyme from wild-type cells was unstable to gel filtration, whereas the corresponding isozyme from an analog-resistant mutant was insensitive to tyrosine inhibition and wa ...	1981	6116697
detection of glutamate synthase in heterocysts of anabaena sp. strain 7120.	the formation of [(14)c]glutamate from [(14)c]glutamine in the presence of alpha-oxoglutarate was observed in extracts of heterocysts of anabaena sp. strain 7120 under conditions that indicate the operation of glutamate synthase.	1981	6118357
purification, physical characterization, and nh2-terminal sequence of glutamine synthetase from the cyanobacterium anabaena 7120.	a procedure for the complete purification of glutamine synthetase (l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2) from the cyanobacterium (blue-green alga) anabaena 7120 is described. the enzyme has structural characteristics in common with glutamine synthetases from other sources: a subunit molecular weight of approximately 50,000 and a native structure, determined by low dose exposure electron microscopy, consisting of a two-layered regular hexagon made up of 12 subunits. sequence analy ...	1981	6118370
kinetic and inhibition studies of glutamine synthetase from the cyanobacterium anabaena 7120.	a number of biochemical parameters of glutamine synthetase (ec 6.3.1.2) isolated from the cyanobacterium anabaena 7120 were determined. apparent michaelis constants for glutamate and atp were found to be 2.1 and 0.32 mm, respectively; that for ammonia was found to be below 20 microm, significantly lower than that reported for glutamine synthetases from other species. serine, alanine, glycine, cysteine, aspartic acid, methionine sulfone, and methionine sulfoximine were found to inhibit the enzyme ...	1981	6118371
new anabaena and nostoc cyanophages from sewage settling ponds.		1981	6269286
[carbon dioxide fixation and its regulation in synechococcus (anacystis nidulans) cyanobacteria].	the bulk of 14co2 assimilated in photosynthesis by the growing culture of synechococcus was incorporated in the cell via the reductive pentose phosphate cycle. up to 70% of the label was incorporated into phosphoglyceric acid and phosphoric esters of sugars at all stages of the active cultural growth after 1 min of exposition in the light in the presence of nah14co3. the relative proportion of the label in phosphorylated compounds of the reductive pentose phosphate cycle decreased if the exposit ...	1981	6163951
specific adhesion of bacteria to heterocysts of anabaena spp. and its ecological significance.	two bacterial isolates, pseudomonas sp. sl10 and zoogloea sp. sl20, attach to heterocysts of anabaena spp. with a high degree of selectivity, and this attachment can be expressed quantitatively in terms of adsorption isotherms. adhesion of pseudomonas sp. sl10 was restricted to a monolayer and exhibited a type i (langmuir) isotherm, whereas adhesion of zoogloea sp. sl20 involved multilayer attachment and exhibited a type ii isotherm. the degree of adhesion by the bacteria to heterocysts of diffe ...	1981	16345901
photosynthetic response to alkaline ph in anabaena variabilis.	the rate of o(2) evolution and alkalization of the medium in low co(2(-) ) grown anabaena variabilis was observed as affected by the ph in the medium. both rates are severely inhibited by ph values higher than 9.5, but the latter is more sensitive to this treatment. this finding, as well as the lag observed in alkalization of the medium, but not in o(2) evolution, following the addition of hco(3) (-) indicates that the transport of hco(3) and oh(-) (or h(+)) are not compulsorily coupled. the inh ...	1981	16661646
phycobilisome-thylakoid topography on photosynthetically active vesicles of porphyridium cruentum.	conditions are described for isolating functional phycobilisome-thylakoid vesicles from the red alga porphyridium cruentum. phycobilisome-thylakoid vesicles were prepared by brief sonication and centrifugation in a medium containing 0.5 molar sucrose, 0.5 molar potassium phosphate, and 0.3 molar sodium citrate (ph 7.0). they required ferricyanide as an oxidant and had o(2) evolution rates (about 450 micromoles o(2) per hour per milligram chlorophyll) higher than whole cells (about 250 micromoles ...	1981	16661723
light and dark reactions of the uptake hydrogenase in anabaena 7120.	reactions of the uptake hydrogenase from anabaena 7120 (a.t.c.c. 27893, nostoc muscorum) were examined in whole filaments, isolated heterocysts, and membrane particles. whole filaments or isolated heterocysts that contained nitrogenase consumed h(2) in the presence of c(2)h(2) or n(2) in a light-dependent reaction. if nitrogenase was inactivated by o(2) shock, filaments catalyzed h(2) uptake to an unidentified endogenous acceptor in the light. addition of no(3) (-) or no(2) (-) enhanced these ra ...	1981	16661985
physiological reactions of the reversible hydrogenase from anabaena 7120.	the reversible hydrogenase from anabaena 7120 appeared when o(2) was continuously removed from a growing culture. activity increased further when cells were incubated under argon in the dark or in the light plus 3-(3,4-dichlorophenyl)-1,1-dimethylurea. hydrogenase existed in an inactive state during periods of o(2) evolution. it could be reductively activated by exposure to reduced methyl viologen or by dark, anaerobic incubation. hydrogenase-containing cells evolved h(2) slowly during dark anae ...	1981	16661986
the azolla-anabaena azollae relationship : xi. phycobiliproteins in the action spectrum for nitrogenase-catalyzed acetylene reduction.	visible absorption spectra are presented for the azolla caroliniana willd.-anabaena azollae strass. association and the individual partners. although absorption by the phycobiliproteins of the endophytic cyanobacterium clearly complements the absorption by the fern pigments, their contribution to the absorption spectrum of the association is effectively concealed by the preponderance of the azolla pigments. action spectra for nitrogenase-catalyzed c(2)h(2) reduction in both the azolla-anabaena a ...	1981	16662130
chilling-susceptibility of the blue-green alga anacystis nidulans: iii. lipid phase of cytoplasmic membrane.	the lipid phase of cytoplasmic membrane was studied by freeze-fracture electron microscopy in the chilling-susceptible blue-green alga, anacystis nidulans. at growth temperatures, intramembrane particles were distributed at random in the fracture faces of cytoplasmic membrane, whereas, at chilling temperatures, the fracture faces were composed of particle-free and particle-containing regions. these findings indicate that lipids of the cytoplasmic membrane were in the liquid-crystalline state at ...	1982	16662143
oxidation of c-type cytochromes by the membrane-bound cytochrome oxidase (cytochrome aa(3)) of blue-green algae.	respiratory particles containing an aa(3)-type cytochrome oxidase were prepared from anacystis nidulans, synechocystis 6714, synechococcus lividus, anabaena variabilis, nostoc sp. strain mac, nostoc muscorum, and mastigocladus laminosus. oxidation of c-type cytochromes by membrane preparations of the different blue-green algae was observed using purified cytochromes from horse heart, candida krusei, tuna, saccharomyces oviformis, rhodospirillum rubrum, rhodospirillum molischianum, rhodopseudomon ...	1982	16662253
involvement of a primary electrogenic pump in the mechanism for hco(3) uptake by the cyanobacterium anabaena variabilis.	the response of the membrane potential to hco(3) (-) supply has been studied in the cyanobacterium anabaena variabilis strain m-3 under various conditions. changes in potential were followed with the aid of the lipophilic cation tetraphenyl phosphonium bromide.addition of hco(3) (-) to co(2)-depleted cells resulted in rapid hyperpolarization. the rate and extent of hyperpolarization were greater in low-co(2)-adapted than in high-co(2)-adapted cells. addition of the electron acceptor p-nitrosodim ...	1982	16662330
induction of hco(3) transporting capability and high photosynthetic affinity to inorganic carbon by low concentration of co(2) in anabaena variabilis.	the apparent affinity of photosynthesis for inorganic carbon in anabaena variabilis strain m-3 increased during the course of adaptation from high to low co(2) concentration (5% and 0.03% v/v co(2) in air, respectively). this was attributed to an increased ability of the cells to accumulate inorganic carbon during the course of adaptation to low co(2) conditions. the release of phycobiliproteins was used to evaluate the sensitivity of the cells to lysozyme treatment followed by osmotic shock. hi ...	1982	16662334
mutual flocculation of algae and clay: evidence and implications.	algae-clay aggregates were formed when algal and clay suspensions were mixed in the presence of an electrolyte. the maximum ratio of clay to algae in the aggregates was 1.7, 0.2, and 0.03 milligrams of clay per milligram of algae (wet weight) for anabaena, chlamydomonas, and chlorella sp., respectively. the aggregates formed at ca(2+) concentrations higher than 5 x 10(-4)m or na(+) concentrations higher than 2 x 10(-2). the mutualf flocculation and subsequent sedimentation have many practical an ...	1982	17809801
feasibility of fe autoradiography as performed on n(2)-fixing anabaena spp. populations and associated bacteria.	fe emits low-energy x rays and auger electrons by electron capture decay. auger electrons are useful for autoradiographic examination of fe incorporation among microbial communities. attainable resolution, in terms of silver grain deposition, is excellent and comparable to h. two known fe-demanding processes, photosynthetic co(2) fixation and n(2) fixation, were examined by autoradiography of anabaena populations. during photosynthetically active (illuminated) n(2)-fixing periods, biological inc ...	1982	16345922
localized tetrazolium reduction in relation to n(2) fixation, co(2) fixation, and h(2) uptake in aquatic filamentous cyanobacteria.	the aquatic filamentous cyanobacteria anabaena oscillarioides and trichodesmium sp. reveal specific cellular regions of tetrazolium salt reduction. the effects of localized reduction of five tetrazolium salts on n(2) fixation (acetylene reduction), co(2) fixation, and h(2) utilization were examined. during short-term (within 30 min) exposures in a. oscillarioides, salt reduction in heterocysts occurred simultaneously with inhibition of acetylene reduction. conversely, when salts failed to either ...	1982	16345923
geosmin and 2-methylisoborneol from cyanobacteria in three water supply systems.	three oscillatoria strains and one anabaena species were isolated from three different water supply systems in california that experienced earthy-musty taste and odor problems in their drinking water. unialgal cultures, free of actinomycetes, were purged using the grob closed-loop stripping analysis method, and the resulting methylene chloride extracts were analyzed on a gas chromatograph/mass spectrometer. geosmin was produced by oscillatoria simplicissima and anabaena scheremetievi, and 2-meth ...	1982	16345978
ecological consequences of long-term exposure of anabaena variabilis (cyanophyceae) to shifts in environmental factors.	cultures of anabaena variabilis were exposed to different light intensities, and the time course of photoadaptation was measured by photosynthetic rate and changes in pigmentation. a shift down in intensity of 284 muein . m . sec caused a temporary decrease in the photosynthetic response followed by gradual adaptation to the new conditions. final chlorophyll a and carotenoid concentrations were reached after 1 day, although other physiological indicators showed that adaptation required 4 days. t ...	1982	16346050
synergistic interaction between anabaena and zoogloea spp. in carbon dioxide-limited continuous cultures.	flocs consisting of anabaena and zoogloea spp. were used as a model system for the study of planktonic phototroph-heterotroph interactions. in co(2)-limited continuous culture (3.2 mumol of nahco(3) liter h, 1.5 mumol of glucose liter h, ph 8.5, d = 0.026 h), the biomass of the phototroph increased 8.6-fold due to association. however, direct co(2) exchange accounted for only a 3.8-fold increase. when the glucose supply rate was increased to 7.5 mumol liter h, there was a 26-fold increase in bio ...	1982	16346070
sequence of the gene coding for the beta-subunit of dinitrogenase from the blue-green alga anabaena.	the nitrogen fixation nif k gene of the blue-green alga anabaena, which codes for the beta-subunit of dinitrogenase, has been subjected to sequence analysis. the nif k protein is predicted to be 512 amino acids long, to have a m(r) or 57,583, and to contain six cysteine residues. three of these cysteines are within peptides homologous to fes cluster-binding cysteinyl peptides from ferredoxins and from a high potential iron protein and, thus, may be ligands to which fes clusters bind in dinitroge ...	1982	16593247
antigenic similarity among anabaena azollae separated from different species of azolla.		1982	6186252
isolation and physical mapping of nitrogen fixation genes from the cyanobacterium anabaena 7120.		1982	6290496
cytochrome b/c complexes with polyprenyl quinol:cytochrome c oxidoreductase activity from anabaena variabilis and rhodopseudomonas sphaeroides ga: comparison of preparations from chloroplasts and mitochondria.		1982	6292024
biochemical diversity for biosynthesis of aromatic amino acids among the cyanobacteria.	we examined the enzymology and regulatory patterns of the aromatic amino acid pathway in 48 strains of cyanobacteria including representatives from each of the five major grouping. extensive diversity was found in allosteric inhibition patterns of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase, not only between the major groupings but also within several of the generic groupings. unimetabolite inhibition by phenylalanine occurred in approximately half of the strains examined; in the other s ...	1982	6119309
regulation of glutamine synthetase activity and synthesis in free-living and symbiotic anabaena spp.	regulation of the synthesis and activity of glutamine synthetase (gs) in the cyanobacterium anabaena sp. strain 7120 was studied by determining gs transferase activity and gs antigen concentration under a variety of conditions. extracts prepared from cells growing exponentially on a medium supplemented with combined nitrogen had a gs activity of 17 mumol of gamma-glutamyl transferase activity per min per mg of protein at 37 degrees c. this activity doubled in 12 h after transfer of cells to a ni ...	1982	6127334
production and properties of cyanobacterial endotoxins.	lipopolysaccharides (lps) were isolated from four species of cyanobacteria (anabaena flos-aquae utex 1444. a. cylindrica, oscillatoria tenuis, and o. brevis) frequently occurring in drinking-water supplies. the cyanobacterial lps contained glucose, xylose, mannose, and rhamnose, but differed from the lps derived from most gram-negative bacteria because of the variable presence of 2-keto-3-deoxyoctonate, heptose, galactose, and glucosamine. cyanobacterial lipid a is characterized by long-chain sa ...	1982	6798930
synthesis of nitrogenase by isolated heterocysts.	heterocysts isolated from anabaena variabilis incorporate [14c]leucine and [35s]methionine into trichloroacetic acid-precipitable material in the light. analysis by polyacrylamide gel electrophoresis shows that the radioactivity is present in polypeptides of discrete sizes. however, the relative proportions of different proteins synthesized by isolated heterocysts differ from the relative proportions of those proteins incorporated by the heterocysts in intact filaments. the two components of nit ...	1982	6800406
cyanobacterial phycobilisomes. role of the linker polypeptides in the assembly of phycocyanin.	the phycocyanin-containing segments of the rod substructures of anabaena variabilis phycobilisomes consist of complexes of phycocyanin with "linker" polypeptides of 27,000 and 32,500 daltons (yu, m.-h., glazer, a. n., and williams, r. c. (1981) j. biol. chem. 256, 13130-13136). complexes (alpha beta)3.27,000, (alpha beta)3.32,500, (alpha beta)6.27,000, [(alpha beta)6.32,500]n, (alpha beta)6.27,000 - (alpha beta)6.32,500 were prepared, where alpha beta represents a monomer of phycocyanin, and 27, ...	1982	6801045
active transport of ferric schizokinen in anabaena sp.	the cyanobacterium anabaena sp. strain atcc 27898 was found to utilize the siderophore schizokinen to accumulate iron from the environment. this organism had previously been shown to produce schizokinen under low-iron conditions, and we observed that the iron-transport capability is also increased in response to iron limitation. uptake activity was specific for ferric schizokinen displayed kinetics typical of a protein-mediated process with an apparent km of 0.04 microm and saturation at high co ...	1982	6806241
studies on spectral characteristics of allophycocyanin isolated from anabaena cylindrica: curve-fitting analysis.		1982	6807208
effect of light intensity and inhibitors of nitrogen assimilation on nh4+ inhibition of nitrogenase activity in rhodospirillum rubrum and anabaena sp.	nitrogenase activity in rhodospirillum rubrum was inhibited by nh4+ more rapidly in low light than in high light. furthermore, the nitrogenase of cells exposed to phosphorylation uncouplers was inhibited by nh4+ more rapidly than was the nitrogenase of controls without an uncoupler. these observations suggest that high levels of photosynthate inhibit the nitrogenase inactivation system. l-methionine-dl-sulfoximine, a glutamine synthetase inhibitor, prevented nh4+ from inhibiting nitrogenase acti ...	1982	6807962
effects of methionine sulphoximine on protein transients during heterocyst differentiation in anabaena and cylindrospermum spp.	heterocystous blue-green algae normally do not develop heterocysts if grown in the medium enriched with ammonium compounds. if such cultures are resuspended in a medium lacking combined nitrogen, the heterocysts differentiate within 24 h. l-methionine-dl-sulphoximine (mso) has been reported to induce heterocysts even in the presence of ammonium chloride. the changes in gel electrophoresis protein profiles of cultures developing heterocysts, in the ammonium chloride enriched medium supplemented w ...	1982	6810560
the pyruvate: ferredoxin oxidoreductase in heterocysts of the cyanobacterium anabaena cylindrica.	heterocyst preparations have been obtained which actively perform nitrogen fixation (c2h2 reduction) and contain the enzymes of glycolysis and some of the tricarboxylic acid cycle. pyruvate: ferredoxin oxidoreductase has been unambiguously demonstrated in extracts from heterocysts by the formation of acetylcoenzyme a, co2 and reduced methyl viologen (ferredoxin) from pyruvate, coenzyme a and oxidized methyl viologen (ferredoxin) as well as by the synthesis of pyruvate from co2, acetylcoenzyme a ...	1982	6810949