Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| organization of the nif genes in cyanobacteria in symbiotic association with azolla and anthoceros. | the sizes of endonuclease digestion fragments of dna from cyanobacteria in symbiotic association with azolla caroliniana or anthoceros punctatus, or in free-living culture, were compared by southern hybridization using cloned nitrogenase (nif) genes from anabaena sp. pcc 7120 as probes. the restriction fragment pattern produced by cyanobacteria isolated from a. caroliniana by culture through symbiotic association with anthoceros differed from that of the major symbiotic cyanobacterium freshly se ... | 1988 | 2841912 |
| primary structure of cotranscribed genes encoding the rieske fe-s and cytochrome f proteins of the cyanobacterium nostoc pcc 7906. | the thylakoid membrane cytochrome b6-f complex (plastoquinol:oxidized-plastocyanin oxidoreductase, ec 1.10.99.1) catalyzes electron-transfer and proton-translocation reactions essential for oxygenic photosynthesis. we have isolated and determined the nucleotide sequences of the petc and peta genes encoding the rieske fe-s and cytochrome f polypeptides from the filamentous cyanobacterium nostoc pcc 7906. these genes occur as single genomic copies, are tightly linked, and, as indicated by hybridiz ... | 1988 | 2842748 |
| characterization of two operons encoding the cytochrome b6-f complex of the cyanobacterium nostoc pcc 7906. highly conserved sequences but different gene organization than in chloroplasts. | we have isolated and determined the nucleotide and derived protein sequences for the four genes, petca and bd, which encode the cytochrome b6-f, electron-transfer complex of the filamentous cyanobacterium, nostoc pcc 7906. the primary structure and cotranscription of the petca genes encoding the rieske-fes (nuclear encoded in plants) and apocytochrome f proteins has been described previously (kallas, t., spiller, s., and malkin, r. (1988) proc. natl. acad. sci. u.s.a., in press). the petbd genes ... | 1988 | 2844767 |
| distinct fractions of genomic dna from cyanobacterium nostoc commune that differ in the degree of methylation. | 1988 | 2854807 | |
| regulation of glutamate dehydrogenase activity and ammonia production in a nitrogen fixing cyanobacterium. | a glutamate auxotroph was obtained in nostoc muscorum by induced mutagenesis with nitrosoguanidine. the metabolic pathway leading to glutamate synthesis was traced by selecting several enzymes. the strain was found to be lacking glutamate dehydrogenase. other enzymes, however, were normal in their activity including isocitric dehydrogenase, glutamine synthetase and glutamate synthase. nitrogen metabolism of the auxotroph and wild type was compared. the strain released exceedingly high amounts of ... | 1986 | 2880448 |
| regulation of expression of glutamine synthetase in a symbiotic nostoc strain associated with anthoceros punctatus. | a characteristic of n2-fixing cyanobacteria in symbiotic associations appears to be release of n2-derived nh4+. the specific activity of the primary ammonium-assimilating enzyme, glutamine synthetase (gs), was found to be three- to fourfold lower in nostoc sp. strain 7801 grown in symbiotic association with the bryophyte anthoceros punctatus than in free-living nostoc sp. strain 7801. quantitative immunological assays with antisera against gs purified from nostoc sp. strain 7801 and from escheri ... | 1987 | 2884210 |
| glutamine synthetase specific activity and protein concentration in symbiotic anabaena associated with azolla caroliniana. | glutamine synthetase (gs) is the primary nh4+ assimilating enzyme of cyanobacteria. the specific activities and cellular protein concentration of gs in symbiotic cyanobacteria associated with the water fern azolla caroliniana were determined and compared to free-living cultures of nostoc sp. strain 7801, a strain originally isolated from symbiotic association with the bryophyte anthoceros punctatus. both the in vitro specific activity and concentration of gs in symbiotic cyanobacteria separated ... | 1988 | 2902827 |
| a low potential iron-sulfur cluster bound to membranes in blue-green algae. | a new low temperature epr signal at g = 1.92 was found in photoreduced membrane fractions prepared from blue-green algae, nostoc muscorum, tolypothrix tenuis, phormidium persicinum, and anabaena variabilis. the signal also appeared when the sample was chemically reduced in the dark. judging from the spectrum, the signal was probably due to the reduced form of a membrane-bound iron-sulfur cluster, tentatively designated as cluster d. the midpoint potential of cluster d was determined to be -0.27 ... | 1985 | 2987203 |
| [role of temperate phage in bacterial dissociation]. | the analysis of literary and own data testifies that the dissociants may appear in bacteria population from spontaneous mutations and transfer of genetic material (conjugation, transformation, transduction). the phage conversion and different dna reorganizations within a cell where prophage plays an active role, probably introduce the largest contribution into the dissociative transitions of variants which occur with high frequency (about 10(-2)-10(-4). the dissociation of various bacteria has b ... | 1986 | 3011128 |
| oxidative phosphorylation and energy buffering in cyanobacteria. | the onset of respiration in the cyanobacteria anacystis nidulans and nostoc sp. strain mac upon a shift from dark anaerobic to aerobic conditions was accompanied by rapid energization of the adenylate pool (owing to the combined action of atp synthase and adenylate kinase) and also the guanylate, uridylate, and cytidylate pools (owing to nucleoside diphosphate and nucleoside monophosphate kinases). rates of the various transphosphorylation reactions were comparable to the rate of oxidative phosp ... | 1986 | 3023299 |
| ferredoxin-thioredoxin reductase, an iron-sulfur enzyme linking light to enzyme regulation in oxygenic photosynthesis: purification and properties of the enzyme from c3, c4, and cyanobacterial species. | ferredoxin-thioredoxin reductase (ftr), an enzyme involved in the light regulation of chloroplast enzymes, was purified to homogeneity from leaves of spinach (a c3 plant) and corn (a c4 plant) and from cells of a cyanobacterium (nostoc muscorum). the enzyme is a yellowish brown iron-sulfur protein, containing four nonheme iron and labile sulfide groups, that catalyzes the activation of nadp-malate dehydrogenase and fructose 1,6-bisphosphatase in the presence of ferredoxin and of thioredoxin m an ... | 1987 | 3028266 |
| analysis of fluorescence kinetics and energy transfer in isolated alpha subunits of phycoerythrin from nostoc sp. | 1986 | 3081920 | |
| effect of tryptophan on 2,4-dichlorophenoxyacetic acid toxicity in the nitrogen-fixing-cyanobacterium nostoc linckia. | the combined effect of a hormone weed killer 2,4-dichlorophenoxyacetic acid (2,4-d) and an amino acid (tryptophan) has been studied on growth and heterocyst differentiation in the cyanobacterium nostoc linckia. 2.4-d at 100 micrograms/ml stimulated growth and heterocyst frequency in combined nitrogen-free medium while its higher concentrations inhibited both. tryptophan under similar conditions promoted much growth yield with 3-4 fold enhanced heterocyst frequency than the control. such heterocy ... | 1986 | 3083089 |
| hydroperoxide metabolism in cyanobacteria. | the enzymes involved in antioxidative activity and the cellular content of the antioxidants glutathione and ascorbate in the cyanobacteria nostoc muscorum 7119 and synechococcus 6311 have been examined for their roles in hydroperoxide removal. high activities of ascorbate peroxidase and catalase were found in vegetative cells of both species and in the heterocysts of n. muscorum. the affinity of ascorbate peroxidase for h2o2 was 15- to 25-fold higher than that of catalase. increased activity of ... | 1986 | 3083778 |
| mutagenesis by ethidium bromide, proflavine and mitomycin c in the cyanobacterium nostoc sp. | ethidium bromide, proflavine, and mitomycin c were strongly lethal but weakly mutagenic to the cyanobacterium nostoc sp. with a view to studying the mode of action of these weak mutagens, their binding to nostoc dna was studied. the spectral changes resulting from the binding of these mutagens to the dna in vitro indicated that probably only electrostatic forces may be involved in the mutagen-dna binding. a similar low level of dna binding in vivo would explain the weakly mutagenic action of the ... | 1986 | 3088444 |
| production, by filamentous, nitrogen-fixing cyanobacteria, of a bacteriocin and of other antibiotics that kill related strains. | colonies of sixty-five filamentous cyanobacteria were screened for the production of temperate phages and/or antibiotics on solid medium. none of them was observed to release phages. however, seven n2-fixing strains were found to produce antibiotics very active against other cyanobacteria. the antibiotic produced by nostoc sp. 78-11a-e represents a bacteriocin of low molecular weight. nostoc sp. atcc 29132 appears to secrete, together with an antibiotic, a protein that inhibits its action. | 1986 | 3094472 |
| influence of cypermethrin and fenvalerate on a green alga and three cyanobacteria isolated from soil. | the effects of two pyrethroid insecticides, cypermethrin and fenvalerate, on a green alga (scenedesmus bijugatus) and three species of cyanobacteria (synechococcus elongatus, nostoc linckia, and phormidium tenue), all isolated from a black cotton soil, were studied using either cell number or chlorophyll a as toxicity criterion. all the four species were either unaffected or stimulated at 5 micrograms ml-1. of the two insecticides, cypermethrin, at 10 to 50 micrograms ml-1, inhibited s. bijugatu ... | 1987 | 3121278 |
| characterization of several tropical strains of anabaena and nostoc: morphological and physiological properties, and plasmid content. | thirty anabaena and nostoc strains isolated from west african soils were characterized for their morphological and physiological properties, and surveyed for plasmids. most strains were found to harbour one to five plasmids whose molecular masses ranged from 1.5 to 120-150 x 10(6) daltons. no relationship between these plasmids and phenotypic properties such as carbon source utilization, antibiotic resistance or cyanophage and toxin production could be established. | 1986 | 3122637 |
| toxicity of nickel and silver to nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids. | exposure of nostoc muscorum to different concentrations of ni and ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (k+, na+). in an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (l-cysteine and l-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for ag than ni. however, metal-induced inhibition o ... | 1987 | 3123194 |
| identification of the region of cyanobacterial plasmid pdu1 necessary for replication in anabaena sp. strain m-131. | shuttle vectors based on plasmid pdu1 from nostoc sp. strain pcc7524 are able to replicate both in escherichia coli and in strains of anabaena and nostoc spp. derivatives partially deleted in the pdu1 portion were tested for their ability to replicate in anabaena sp. strain m-131. plasmid prl6he containing a 1.75-kb hindiii-scai fragment of pdu1 replicated stably in that cyanobacterium and also in anabaena sp. strain pcc7120. plasmid prl6hc, containing an even smaller hpai-scai fragment (1.3 kb) ... | 1988 | 3131190 |
| impact of chromium and lead on nostoc muscorum: regulation of toxicity by ascorbic acid, glutathione, and sulfur-containing amino acids. | nostoc muscorum can be protected from cr and pb toxicity by supplementing 10 micrograms/ml of ascorbic acid, reduced glutathione, and 5 micrograms/ml of sulfur-containing amino acids (l-methionine and l-cysteine). appreciable stimulation of different parameters of nostoc by ascorbic acid and glutathione was noticed in the untreated culture. these substances when used in the presence of metals were found to restore ionic loss, growth, 14co2 uptake, heterocyst production, and nitrogenase activity ... | 1988 | 3132363 |
| cloning of nifhd from nostoc commune utex 584 and of a flanking region homologous to part of the azotobacter vinelandii nifu gene. | the heterocystous cyanobacterium nostoc commune utex 584 contains two nifh-like sequences (nifh1 and nifh2) in addition to nifhd. a region of dna 1 kilobase upstream from the 5' end of nifh showed considerable sequence similarity to part of the published nifu sequences of azotobacter vinelandii and klebsiella pneumoniae. | 1988 | 3133363 |
| antibiotic effects on growth and heterocyst differentiation of the cyanobacterium nostoc muscorum. | in a medium free of combined nitrogen, 1.0-6.0 micrograms/ml chloramphenicol gradually decreased the growth of the nitrogen-fixing cyanobacterium nostoc muscorum; at 2.0 micrograms/ml the culture appeared yellowish, heterocyst frequency was not evident up to 3.0 micrograms/ml, whereas 4.0 micrograms/ml suppressed heterocyst differentiation. lower concentrations (0.0125-0.75 microgram/ml) of rifampicin suppressed the growth but had no significant effect on heterocyst frequency in liquid medium, w ... | 1988 | 3142201 |
| effect of insecticides and phenolics on nitrogen fixation by nostoc linckia. | 1988 | 3145048 | |
| identification of facultatively heterotrophic, n2-fixing cyanobacteria able to receive plasmid vectors from escherichia coli by conjugation. | plasmid vectors transferable by conjugation from escherichia coli to obligately photoautotrophic strains of anabaena spp. are also transferred to and maintained in heterotrophic, filamentous cyanobacteria of the genus nostoc. these organisms can be used for the genetic analysis of oxygenic photosynthesis, chromatic adaptation, nitrogen fixation, and heterocyst development. | 1985 | 3922953 |
| prokaryotic triterpenoids. 1. 3 beta-methylhopanoids from acetobacter species and methylococcus capsulatus. | 3 beta-methylbacteriohopanepolyol derivatives were isolated from three bacteria, acetobacter pasteurianus ssp. pasteurianus, methylococcus capsulatus and nostoc muscorum, and identified by spectroscopic methods and direct comparison with 3 beta-methyldiplopterol and 3 beta-methylhopan-29-ol synthesized from 22-hydroxyhopan-3-one. the 3 beta-methylhopanoid content of a. pasteurianus ssp. pasteurianus could be dramatically increased (up to 60% of the total hopanoid content) by addition of l-methio ... | 1985 | 3926494 |
| prokaryotic triterpenoids. 2. 2 beta-methylhopanoids from methylobacterium organophilum and nostoc muscorum, a new series of prokaryotic triterpenoids. | 2 beta-methylhopanoids, a new series of triterpenoids was identified from two prokaryotes. 2 beta-methyldiplopterol was isolated from the methylotrophic bacterium methylobacterium organophilum, and three different 2 beta-methylbacteriohopanepolyols from the cyanobacterium nostoc muscorum. the structures of these compounds was deduced by direct comparison with 2 beta-methyldiplopterol synthesized from 22-hydroxyhopan-3-one. | 1985 | 3926495 |
| the role of glutathione and ascorbate in hydroperoxide removal in cyanobacteria. | the antioxidative potential of cyanobacteria to scavenge hydroperoxides formed as by-products of photosynthetic activity was investigated in nostoc muscorum 7119 and synechococcus 6311. these cells contained a high concentration of glutathione, 2-5 mm, and a low concentration of ascorbate, 20-100 um. no glutathione peroxidase was detected while the activity of ascorbate peroxidase was high, reacting with hydrogen peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. dehydroascorbate reducta ... | 1985 | 3933503 |
| protein synthesis and proteolysis in immobilized cells of the cyanobacterium nostoc commune utex 584 exposed to matric water stress. | cells of the cyanobacterium nostoc commune utex 584 in exponential growth were subjected to acute water stress by immobilizing them on solid supports and drying them at a matric water potential (psi m) of -99.5 mpa. cells which had been grown in the presence of na235so4 before immobilization and rapid drying continued to incorporate 35s into protein for 90 min. this incorporation was inhibited by chloramphenicol. no unique proteins appeared to be synthesized during this time. upon further drying ... | 1985 | 3934134 |
| isolation and characterization of a virus infecting the blue-green alga nostoc muscorum. | 1971 | 4108613 | |
| light-induced oxidation-reduction reactions in a cell-free preparation from the blue-green alga nostoc muscorum: the role of cytochrome f, cytochrome b558, c550, and p700 in noncyclic electron transport. | 1973 | 4148619 | |
| possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction. | 1969 | 4181442 | |
| role of reduced exogenous organic compounds in the physiology of the blue-green bacteria (algae): photoheterotrophic growth of a "heterotrophic" blue-green bacterium. | nostoc sp. (strain mac) was shown to be capable of using glucose, fructose, or sucrose as a sole source of carbon and energy in the dark. in the light in the absence of exogenously supplied co(2), this strain exhibited a more versatile metabolism. in addition to the three sugars above, glycerol and acetate served as sole sources of carbon. this photoheterotrophic growth in the absence of exogenously supplied co(2) appears to involve o(2)-evolving photosynthesis. the action spectrum for photohete ... | 1973 | 4196252 |
| ultrastructural development of nostoc muscorum a. | 1973 | 4198641 | |
| differentiation in nostoc muscorum: nitrogenase is synthesized in heterocysts. | cellular differentiation can be observed in certain filamentous blue-green algae after transfer of the cells from medium containing nh(4) (+) or no(3) (-) to nitrogen-free medium. the appearance of differentiated cells (heterocysts) is accompanied by an increase in the activity of nitrogenase, an enzyme complex that reduces n(2) to nh(3). we have separated vegetative cells from heterocysts in differentiated filaments of nostoc muscorum, and analyzed their proteins by polyacrylamide-gel electroph ... | 1973 | 4200722 |
| phycobilisomes from a blue-green alga nostoc species. | phycobilisomes were isolated from a nostoc sp. strain mac in phosphate buffer (ph 7.0) by treatment with 1% brij 56 and centrifugation on discontinuous sucrose gradients (2.0, 1.0, 0.5, and 0.25 m in the proportions 6:4:4:10 ml, respectively). absorption spectra of isolated phycobilisomes showed the presence of phycoerythrin, phycocyanin, and allophycocyanin. the phycobilisome pigments were partially resolved by electrophoresis on acrylamide gels. stained gels demonstrated that each main protein ... | 1973 | 4200843 |
| phycobilisomes in blue-green algae. | fifteen species of freshwater blue-green algae, including unicellular, filamentous, and colonial forms, were subjected to a variety of fixatives, fixation conditions, and stains for comparison of the preservation of phycobilisomes. absorption spectra of the corresponding in vivo and released photosynthetic pigments, in 10 of the species that were maintained in culture, demonstrated the presence of phycocyanin in all 10 species and phycoerythrin in only 2 of them. spectroscope and electron micros ... | 1974 | 4204443 |
| heterotrophic growth of the nitrogen fixing blue-green alga nostoc muscorum. | 1974 | 4212052 | |
| [nitrogen excretion by nitrogen fixing blue-green algae. i. growth of anabaena cylindriea and nostoc muscorum in various media, at different temperatures, and under light of different wavelengths (author's transl)]. | 1973 | 4272180 | |
| occurrence of cell lytic enzymes in blue-green bacteria. | detergent extracts of three blue-green bacteria (agmenellum quadruplicatum strain bg1, anacystis nidulans strain tx20, and nostoc sp. strain mac) contained enzymes capable of lysing suspensions of micrococcus lysodeikticus. the enzyme preparation from a. quadruplicatum released soluble reducing fragments from purified peptidoglycan. the lytic activity exhibited a ph optimum between 6 and 7, was relatively heat stable, and was susceptible to attack by proteolytic enzymes. these results extend the ... | 1973 | 4745432 |
| cytophaga that kills or lyses algae. | a myxobacterium (cytophaga n-5) isolated from sewage kills or lyses an array of living green and blue-green algae. when assayed with nostoc muscorum or plectonema boryanum, plaques form like those caused by the blue-green algal virus lpp-1. this isolate lyses or inhibits mutually gram-positive and gram-negative eubacteria. | 1969 | 4891858 |
| purification and properties of glycogen isolated from a blue-green alga, nostoc muscorum. | alpha granules were isolated from a blue-green alga, nostoc muscorum, in large quantities and high purity by sucrose density gradient centrifugation. sodium deoxycholate was used to eliminate membrane contamination. isolated alpha granules from this species have average dimension of 31 nm in width and 65 nm in length. each alpha granule consists of two equal parts. attempts to dissociate the intact granule under mild conditions into relatively large subunits did not succeed. analytical centrifug ... | 1971 | 4993320 |
| nitrogen metabolism of nostoc muscorum & phormidiu phormidium fragile. | 1971 | 5004444 | |
| fixation of elementary nitrogen by nostoc punctiforme (kütz.) hariot and scytonema bohneri schmidle in pure and unialgal cultures. | 1970 | 5412270 | |
| possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction. | 1969 | 5779919 | |
| induction by ultraviolet irradiation of mutation in the blue-green alga nostoc linckia (roth) born. et flah. | 1969 | 5782614 | |
| biosynthesis of alkanes in nostoc muscorum. | 1969 | 5798100 | |
| [fixation of molecular nitrogen by some representatives of the genera aanbaena and nostoc]. | 1966 | 5995733 | |
| the role of na2s in anoxygenic photosynthesis and h2 production in the cyanobacterium nostoc muscorum. | na2s is known to support anoxygenic photosynthesis in some strains of cyanobacteria and to stimulate h2 production in n2 fixing filaments of nostoc muscorum. we have shown electron transfer between na2s and photosystem i to be dependent on cytochrome b559 which was detected only in vegetative cells. an electron mediator was required to support na2s driven nitrogenase activity in isolated heterocysts. na2s was also found to deplete the atp pool, probably by inhibiting electron transfer from photo ... | 1984 | 6091649 |
| 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 |
| polyadenylated rna in two filamentous cyanobacteria. | polyadenylated rna was detected in the cyanobacteria nostoc sp. strain mac and anabaena variabilis by oligodeoxythymidylic acid-cellulose chromatography and by hybridization to [3h]polyuridylic acid. polyadenylate tracts from a. variabilis were located at the 3' end of rna chains and had an estimated length of 15 to 22 nucleotides. | 1983 | 6195149 |
| new anabaena and nostoc cyanophages from sewage settling ponds. | 1981 | 6269286 | |
| a physical map of plasmid pdu1 from the cyanobacterium nostoc pcc 7524. | 1982 | 6283572 | |
| nostoc pcc7524, a cyanobacterium which contains five sequence-specific deoxyribonucleases. | five nucleotide sequence-specific deoxyribonucleases present in cell-free extracts of the filamentous cyanobacterium nostoc pcc7524 have been purified and characterized. one of these enzymes, designated nsp(7524)i cleaves at a new kind of nucleotide sequence, i.e. 5'-pucatg py-3'. the other four restriction enzymes in this organism, designated nsp(7524)ii, nsp(7524)iii, nsp(7524)iv and nsp(7524)v, are isoschizomers of enzymes which have been previously described. the cleavage site of nsp(7524)ii ... | 1982 | 6298063 |
| a restriction map of plasmid pdc1 from the filamentous cyanobacterium nostoc sp. mac pcc 8009. | a plasmid designated pdc1 from the cyanobacterium nostoc sp. mac pcc 8009 was incubated with 16 different restriction enzymes, of which 8 cleaved pdc1. plasmid pdc1 has a single site for clai, two sites for each of bgli, ecori, ecorv, and mlui, three sites for hpai, and four for hindiii. a restriction map of pdc1 for these 7 enzymes was constructed. | 1983 | 6314412 |
| resistance of dna from filamentous and unicellular cyanobacteria to restriction endonuclease cleavage. | chromosomal dna from nine species of filamentous cyanobacteria as diverse as nostoc, gloeotrichia and plectonema is suggested to be extensively modified (methylated) by its resistance to cleavage by a number of restriction endonucleases. a remarkably similar pattern of dna modification in these species contrasts with the known heterogeneity of their type ii restriction endonuclease content. in particular, nostoc pcc 73102, which lacks detectable sequence-specific endonucleases, is shown to posse ... | 1984 | 6320895 |
| thylakoid morphology of the cyanobacteria anabaena variabilis and nostoc mac grown under light and dark conditions. | anabaena variabilis (atcc 29413) and nostoc sp. strain mac were grown photoautotrophically and chemoheterotrophically. thylakoid morphology of cells from both types of culture was investigated by freeze-etching electron microscopy. peripheral and concentric arrays of thylakoid membranes seen in autotrophic cells were replaced, in heterotrophic cells, by numerous vesicular or tubular structures; the changes were reversible. heterotrophic cells showed a reduced overall content of chlorophyll but s ... | 1983 | 6402604 |
| the isocitrate dehydrogenase from cyanobacteria. | the present communication describes the properties of isocitrate dehydrogenase in crude extracts from the unicellular anacystis nidulans and from heterocysts and vegetative cells of nostoc muscorum and anabaena cylindrica. the activity levels of this enzyme are much higher in heterocysts than in vegetative cells of n. muscorum and a. cylindrica. isocitrate dehydrogenase is virtually inactive in vegetative cells of a. cylindrica. the enzyme is negatively regulated by the reduction charge and scar ... | 1983 | 6409049 |
| regulation of nostoc sp. phycobilisome structure by light and temperature. | nostoc sp. strain mac cyanobacteria were green in color when grown in white light at 30 degrees c and contained phycobilisomes that had phycoerythrin and phycocyanin in a molar ratio of 1:1. cells grown for 4 to 5 days in green light at 30 degrees c or white light at 39 degrees c turned brown and contained phycoerythrin and phycocyanin in a molar ratio of greater than 2:1. in addition to the change in pigment composition, phycobilisomes from brown cells were missing a 34.5-kilodalton, rod-associ ... | 1983 | 6411691 |
| metabolic activities of isolated akinetes of the cyanobacterium nostoc spongiaeforme. | intact akinetes (spores) of the cyanobacterium nostoc spongiaeforme can be isolated free of vegetative cells and heterocysts. the akinetes remain viable for at least 2 weeks in distilled water. they do not germinate in water but do so readily when transferred subsequently to cyanobacterial growth medium. isolated, nongerminating akinetes incorporated 35s from na235so4 into protein and lipid. similar incorporation was observed when akinetes were isolated from old cultures (containing primarily ak ... | 1983 | 6413494 |
| isolation of polysomes from nostoc sp. mac and translation of messenger rna in a heterologous cell-free system. | a method has been established which isolated polysomes from the lysozyme/edta-shocked cyanobacterium, nostoc sp. mac. in a typical preparation the total recovery of rna as polysomes was 83%, in which 77% of the polysome fraction was present at sizes greater than 5-mers and 23% as 2-4-mers. messenger rna isolated from such a preparation of polysomes produced a 10-fold stimulation in the incorporation of [35s]methionine into polypeptides by a cell-free system of escherichia coli. the in vitro-synt ... | 1983 | 6415228 |
| transfer of nitrate reductase genes of the cyanobacterium nostoc muscorum into rhizobium japonicum. | transformation of rhizobium japonicum cb1809 was studied using dna from the cyanobacterium nostoc muscorum atcc 27893. a spontaneous nitrate reductase deficient (nar-) mutant (nr-6) of r. japonicum cb1809 was isolated with a frequency of 8.4 x 10(-7). streptomycin (sm) and neomycin (neo) resistance markers were introduced into strain nr-6, and the resulting strain was designated nr-6 smr neor. experiments with cyanobacterial dna and live cells of strain nr-6 smr neor indicated transformation of ... | 1983 | 6415231 |
| inhibition of photosystem ii of nitrogen-fixing blue-green alga nostoc linckia by the rice-field herbicide benthiocarb. | effects of rice-field herbicide benthiocarb (s(4-chlorobenzyl)-n,n-diethyl thiolcarbamate) was studied on the nitrogen-fixing blue-green alga nostoc linckia. the herbicide caused inhibition of growth and heterocyst formation, an increase in intensity of photoacoustic signals, and a four-fold reduction in oxygen evolution, but did not affect dark o2-uptake. the inhibition of growth and heterocyst formation was relieved by 500 micrograms/ml glucose. a het-nif- mutant of nostoc muscorum failed to s ... | 1983 | 6415936 |
| [fractionation of phycobilisomes from the blue-green alga nostoc muscorum]. | phycobilisomes (pbs) isolated from nostoc muscorum contain eight spectral forms of phycobiliproteins. pbs partially dissociated by osmotic or temperature shock, were separated into 42s and 34s particles by centrifugation in sucrose density gradient. the 42s particles are enriched with phycocyanin, the 34s ones--with allophycocyanin. the 42s particles dissociate to free pigments by repeated osmotic or temperature shock and the 34s ones dissociate to subparticles i and ii having the constant pigme ... | 1984 | 6423967 |
| redox potentials of algal and cyanobacterial flavodoxins. | the redox potentials of flavodoxins from the cyanobacteria synechococcus pcc 6301 (formerly anacystis nidulans) and nostoc strain mac, and from the red alga chondrus crispus, were determined by potentiometric titration. for the oxidized-semiquinone interconversion the potentials at ph 7.0 of the three flavodoxins were between -210 and -235 mv, and these were ph-dependent over the range ph 6.9-8.2. for the semiquinone-reduced interconversion the potentials of the cyanobacterial flavodoxins were c ... | 1984 | 6424653 |
| [energy migration in phycobilisomes]. | fluorescence emission and polarization spectra of the phycobilisomes (pbs) of the blue-green alga nostoc muscorum were measured at 20, -73 and -196 degrees c while exciting at the absorption maximum of each pigment in the pbs. the emission spectra were deconvoluted into a number of gaussian components and energy migration coefficients and quantum yields of fluorescence for the 8 forms of the phycobilins constituting the pbs were calculated. the overlap integrals and the critical and real distanc ... | 1984 | 6425643 |
| powerful mutagenicity of a bipyridylium herbicide in a nitrogen-fixing blue-green alga nostoc muscorum. | the herbicide, paraquat (1,1'-dimethyl-4,4'-bipyridylium ion), was found to be toxic and lytic to nostoc muscorum in n2 (at the expense of elemental nitrogen, i.e. unsupplemented with any combined nitrogen source) and no-3 media, without any apparent inhibitory or stimulatory effect on its nitrogen-fixing apparatus, i.e. heterocyst formation. at a dose of paraquat resulting in 20, 50 and 75% survival, induction of reverse mutations (from het- nif- auxotrophy to het+ nif+ prototrophy), forward mu ... | 1984 | 6436694 |
| regulatory effect of hydrogen on nitrogenase activity of the blue-green alga (cyanobacterium) nostoc muscorum. | preincubation of the blue-green alga (cyanobacterium) nostoc muscorum under an atmosphere of argon plus acetylene in the light led to a greater than fourfold increase of light-induced hydrogen evolution and to a 50% increase of acetylene reduction, as compared to cells that had not been preconditioned. the basic and the increased hydrogen evolution were both due to nitrogenase activity. furthermore, after preincubation the hydrogen uptake, usually observed with unconditional cells, was abolished ... | 1980 | 6767700 |
| components and activity of the photosynthetic electron transport system of intact heterocysts isolated from the blue-green alga nostoc muscorum. | heterocysts of the blue-green alga nostoc muscorum have been isolated by prolonged treatment with lysozyme. quantitative data are presented which show the occurrence of cytochromes c-553, f-557 and b-563 in heterocysts in amounts comparable to vegetative cells. particularly the content of the water-soluble cytochrome c-553 can be used to evaluate the intactness of a heterocyst preparation. cytochrome f-557 has been partially purified and found to be a c-type cytochrome corresponding to cytochrom ... | 1980 | 6772215 |
| spectral analysis of allophycocyanin i, ii, iii and b from nostoc sp. phycobilisomes. | low temperature (-196c) and room temperature (25c) absorption spectra of a family of allophycocyanin spectral forms isolated from nostoc sp. phycobilisomes as well as of the phycobilisomes themselves have been analyzed by gaussian curve-fitting. allophycocyanin i and b share long wavelength components at 668 and 679 nm, bands that are absent from allophycocyanin ii and iii. these long wavelength absorption components are apparently responsible for the 20 nm difference between the 680 nm fluoresc ... | 1980 | 6773565 |
| apoflavodoxin aggregation following dissociation of flavin. | flavodoxins were isolated for the cyanobacteria anacystis nidulans and nostoc strain mac, and from the red alga chondrus crispus, and apoflavodoxins prepared by five methods. gel electrophoretic studies showed that whereas the apoproteins of a. nudulans and nostoc strain mac were recovered in monomeric form, the removal of riboflavin 5'-phosphate from c. crispus flavodoxin resulted in extensive aggregation of the apoprotein. in extent and nature this aggregation differed with the dissociating ag ... | 1980 | 6774761 |
| cell size and heterocyst differentiation in nostocacean blue-green algae. | cell size variations in three heterocystous blue-green algae, viz. nostoc muscorum (isu strain), n. muscorum (uw strain) and n. calcicola (a local isolate) have been surveyed under conditions permissive and non-permissive of heterocyst differentiation. a monomodal distribution pattern was observed for the two strains of n. muscorum under conditions not requiring heterocyst differentiation, while elemental nitrogen grown cultures retained a group of relatively larger cells in addition to this mod ... | 1980 | 6775879 |
| increase of nitrogenase activity in the blue-green alga nostoc muscorum (cyanobacterium). | preincubation of the blue-green alga (cyanobacterium) nostoc muscorum under hydrogen or argon (nongrowing conditions, neither co(2) nor n(2) or bound nitrogen present) in the light resulted in a two- to fourfold increase of light-induced hydrogen evolution and a 30% increase of acetylene reduction. preincubation under the same gases in the dark led to a decrease of both activities. cultivation of algae under a hydrogen-containing atmosphere (n(2), h(2), co(2)) increased neither hydrogen nor ethy ... | 1980 | 6777364 |
| 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 |
| atp-dependent uptake of nitrate in nostoc muscorum and inhibition by ammonium ions. | a high rate of nitrate uptake was observed in nostoc muscorum when cells were grown on elemental nitrogen as compared to that when they were grown on nitrate or ammonium. the uptake of nitrate was light dependent. however, supplementation with atp (50 microm) stimulated nitrate uptake both in light and darkness. adp, under similar conditions had no effect. 3-(3,4-dichlorophenyl)-1,1-dimethylurea (dcmu), 2-n-heptyl-4-hydroxyquinoline, (hoqno) and kcn inhibited nitrate uptake in light which could ... | 1981 | 6786358 |
| isolation and preliminary characterization of mutants of the cyanobacterium nostoc muscorum resistant to growth inhibition by methylamine. | the wild-type heterocystous and nitrogen-fixing (het+nif+) n. muscorum and its non-heterocystous non-nitrogen-fixing (het-nif-) mutant strain both fail to grow in different inorganic nitrogen media containing 1 mm methylamine hydrochloride (ma). mutants of the het+nif+ and het-nif- parents resistant to growth inhibition by 5 mm ma and thus designated as mar strains were isolated with a frequency of 2.5(+/- 2.4) x 10(6). a mar strain of the het+nif+ and a mar strain of the het-nif- parent were ch ... | 1981 | 6799749 |
| amino acid sequences of nostoc strain mac ferredoxins i and ii. | the amino acid sequences of ferredoxins i and ii from a blue-green alga, nostoc strain mac were determined. this alga is able to grow autotrophically in the light or heterotrophically in the dark. analyses of tryptic peptides of cm-proteins by conventional methods including solid-phase edman degradation gave the complete amino acid sequences. both molecules consisted of 98 amino acid residues and 34 amino acid differences including two deletions were found between the two. comparing these sequen ... | 1982 | 6818220 |
| efficiency of ferredoxins and flavodoxins as mediators in systems for hydrogen evolution. | 1. the efficiencies of ferredoxins and flavodoxins from a range of sources as mediators in systems for hydrogen evolution were assessed. 2. in supporting electron transfer from dithionite to hydrogenase of the bacterium clostridium pasteurianum, highest activity was shown by the ferredoxin from the cyanobacterium chlorogloeopsis fritschii and flavodoxin from the bacterium megasphaera elsdenii. the latter was some twenty times as active as comparable concentrations of methyl viologen. ferredoxins ... | 1980 | 7016115 |
| allophycocyanin from nostoc sp. phycobilisomes. properties and amino acid sequence at the nh2 terminus of the alpha and beta subunits of allophycocyanins i, ii, and iii. | allophycocyanin from nostoc sp. phycobilisomes was separated into four spectrally distinct components designated allophycocyanin i, b, ii, and iii by adsorption chromatography on brushite columns. allophycocyanins i and b had red-shifted fluorescence emission maxima, and on this basis, may function in transfer of excitation energy from phycobilisomes to chlorophyll a. allophycyanins ii and iii, which together comprise 70% of the total allophycocyanin, have absorption maxima at 648 nm and 650 nm, ... | 1980 | 7410430 |
| a gene encoding a protein related to eukaryotic protein kinases from the filamentous heterocystous cyanobacterium anabaena pcc 7120. | protein kinases play essential roles in the development of eukaryotic cells. these enzymes display various degrees of sequence similarity in their catalytic domains. this conservation has allowed the identification of protein kinases in a variety of organisms, including the gram-negative bacterium myxococcus xanthus. in this study, sequences related to those encoding eukaryotic protein kinases were amplified by pcr from dna of anabaena pcc 7120, a filamentous cyanobacterium that differentiates c ... | 1993 | 7505448 |
| structure and evolution of paramecium hemoglobin genes. | hemoglobin (hb) genes have been cloned from three different species of ciliated protists, p. multimicronucleatum, p. triaurelia and p. jenningsi. southern blotting of the genomic dnas using the p. caudatum hb cdna showed both intraspecies variation in different stocks of p. caudatum and interspecies variation within the genus paramecium. the isolated hb genes were composed of 118, 117 and 117 codons, and interrupted by a short intron with 27, 29 and 29 bp at the same position, in p. multimicronu ... | 1995 | 7578257 |
| two heterocyst-specific dna rearrangements of nif operons in anabaena cylindrica and nostoc sp. strain mac. | two site-specific dna rearrangements occur during heterocyst differentiation in the cyanobacterium anabaena sp. strain pcc 7120: the deletion of an 11 kb element from within the nifd gene and the deletion of a 55 kb element from within the fdxn gene. three nostoc and six anabaena strains were screened for the presence of the nifd and fdxn elements by southern hybridization with anabaena pcc 7120 dna probes. eight of the nine strains contained dna sequences that were similar to the nifd element. ... | 1995 | 7582007 |
| characterization of toxin-producing cyanobacteria by using an oligonucleotide probe containing a tandemly repeated heptamer. | cyanobacteria produce toxins that kill animals. the two main classes of cyanobacterial toxins are cyclic peptides that cause liver damage and alkaloids that block nerve transmission. many toxin-producing strains from finnish lakes were brought into axenic culture, and their toxins were characterized. restriction fragment length polymorphism analysis, probing with a short tandemly repeated dna sequence found at many locations in the chromosome of anabaena sp. strain pcc 7120, distinguishes hepato ... | 1995 | 7592362 |
| genetic evidence of a major role for glucose-6-phosphate dehydrogenase in nitrogen fixation and dark growth of the cyanobacterium nostoc sp. strain atcc 29133. | heterocysts, sites of nitrogen fixation in certain filamentous cyanobacteria, are limited to a heterotrophic metabolism, rather than the photoautotrophic metabolism characteristic of cyanobacterial vegetative cells. the metabolic route of carbon catabolism in the supply of reductant to nitrogenase and for respiratory electron transport in heterocysts is unresolved. the gene (zwf) encoding glucose-6-phosphate dehydrogenase (g6pd), the initial enzyme of the oxidative pentose phosphate pathway, was ... | 1995 | 7592384 |
| characterization of ts-mutants of cyanophage n-1 by their inactivation by physical and chemical agents. | the effect of temperature, ultraviolet (uv) light and ethylenediaminetetraacetic acid (edta) on the stability of cyanophage n-1, infecting the cyanobacterium nostoc muscorum was studied. complete inactivation of the phage occurred at 60 degrees c in 6 mins. all the temperature-sensitive (ts) mutants exhibited faster inactivation at 50 degrees c than the wild type. uv light readily inactivated the particles of the wild giving a survival of 3.44% at a dose of 60 secs. all the ts-mutants were found ... | 1995 | 7676938 |
| a protein-tyrosine/serine phosphatase encoded by the genome of the cyanobacterium nostoc commune utex 584. | protein-tyrosine phosphorylation has long been regarded as an exclusively eukaryotic phenomenon. although some non-eukaryotes, mainly viruses, possess genes encoding protein-tyrosine kinases or protein-tyrosine phosphatases, these were probably appropriated from the eukaryotic hosts that constitute the sites of action of these enzymes. herein we identify a gene, iphp, from the chromosome of the cyanobacterium nostoc commune utex 584 that contains the his-cys-xaa-ala-gly-xaa-xaa-arg sequence char ... | 1993 | 7681825 |
| structure of a novel oligosaccharide-mycosporine-amino acid ultraviolet a/b sunscreen pigment from the terrestrial cyanobacterium nostoc commune. | water-soluble uv-a/b-absorbing pigments are secreted by cells of the cosmopolitan terrestrial cyanobacterium nostoc commune. the pigments constitute a complex mixture of monomers with molecular masses of up to 1801 da. two different chromophores with absorption maxima at 312 and 335 nm are linked to different amino acids and to oligosaccharides consisting of galactose, glucose, xylose, glucuronic acid, and glucosamine. the 335 nm chromophore is a 1,3-diaminocyclohexen derivative, while the chrom ... | 1995 | 7721752 |
| growth and some physiological aspects of nostoc muscorum in response to mixtures of two triazine herbicides. | 1995 | 7742636 | |
| multiple metal resistance in the cyanobacterium nostoc muscorum. | 1995 | 7767039 | |
| plasmid and chromosomal dna recovery by electroextraction of cyanobacteria. | high voltage electroporation has been investigated as a method for rapid recovery of plasmid and chromosomal dna from the cyanobacteria nostoc pcc 7121, synechococcus pcc 7002, and anabaena pcc 7120. pulses of 18 kv/cm and higher applied to concentrated nostoc cells carrying a shuttle plasmid (prl25) resulted in copious release of nucleic acids and phycobiliproteins into the suspending medium. small portions of these supernatants, when electroporated with escherichia coli, gave rise to hundreds ... | 1995 | 7781980 |
| desiccation tolerance of prokaryotes. | the removal of cell-bound water through air drying and the addition of water to air-dried cells are forces that have played a pivotal role in the evolution of the prokaryotes. in bacterial cells that have been subjected to air drying, the evaporation of free cytoplasmic water (vf) can be instantaneous, and an equilibrium between cell-bound water (vb) and the environmental water (vapor) potential (psi wv) may be achieved rapidly. in the air-dried state some bacteria survive only for seconds where ... | 1994 | 7854254 |
| cadmium mediated control of nitrogenase activity and other enzymes in a nitrogen fixing cyanobacterium. | cadmium decreased the specific growth rate and total cell mass at concentrations > 0.001 micrograms ml-1. it also reduced heterocyst frequency, total cell protein, nitrogenase activity (acetylene reduction) and decreased glutamine synthetase (gs) and glutamate synthase (gogat) activities. however, cells grown under low concentration of cadmium (0.001 microgram ml-1) had enhanced nitrogenase as well as gs activity besides showing increased growth rate and heterocyst frequency. cadmium has apparen ... | 1994 | 7866728 |
| nucleotide sequence of an operon in nostoc sp. strain atcc 29133 encoding four genes of the oxidative pentose phosphate cycle. | 1995 | 7870816 | |
| transposon mutagenesis of nostoc sp. strain atcc 29133, a filamentous cyanobacterium with multiple cellular differentiation alternatives. | nostoc sp. strain atcc 29133 (pcc 73102; nostoc 29133) is a symbiotically-competent, facultatively heterotrophic, diazotrophic cyanobacterium with the capacity to differentiate specialized cells such as heterocysts, akinetes and hormogonial filaments. we have optimized several methods for physiological and molecular genetic analysis of nostoc 29133. by use of a tn5 derivative, tn5-1063 (km(r)bm(r)sm(r)), delivered by conjugation from escherichia coli, antibiotic-resistant mutants of nostoc 29133 ... | 1994 | 7881544 |
| sequence of a 2.6-kb cryptic plasmid from a marine cyanobacterium synechococcus sp. | we have shown previously that the copy number of plasmid psy10 from the marine cyanobacterium synechococcus sp. nkbg 042902 is dependent on the salinity of the growth medium. we report here the complete nucleotide sequence (2561 bp) of this plasmid. the longest open reading frame, orf-b (1.08 kb), occurs on a 1.6-kb ecori fragment. this orf encodes a putative protein which is 360 aa residues in length and is 37.8% homologous to the replication protein of plasmid pca2.4 from synechocystis sp. str ... | 1994 | 7899510 |
| biochemical effects of carbaryl on nitrogen assimilating enzymes of cyanobacteria nostoc muscorum. | 1994 | 7912573 | |
| cryptophycin: a new antimicrotubule agent active against drug-resistant cells. | cryptophycin is a cytotoxic dioxadiazacyclohexadecenetetrone isolated from cyanobacteria of the genus nostoc. incubation of l1210 leukemia cells with cryptophycin resulted in dose-dependent inhibition of cell proliferation in parallel with increases in the percentage of cells in mitosis (half-maximal effects at < 10 pm). indirect immunofluorescence studies demonstrated that treatment of a-10 vascular smooth muscle cells with cryptophycin results in marked depletion of cellular microtubules and r ... | 1994 | 7913408 |
| cloning and nucleotide sequence of the gene encoding dinitrogenase reductase (nifh) from the cyanobacterium nostoc 6720. | the nucleotide sequence of the 3' end of the nifu coding sequence, the complete coding sequence of nifh and a substantial part of the 5' end of nifd coding sequence from nostoc 6720 is presented. the coding sequences are highly conserved with those of anabaena 7120 and anabaena sp. l31. however the intergenic region between nifu and nifh contains two segments of short tandemly repetitive repeat sequences (strrs) that differ from the strr that is common to both anabaena7120 and anabaenasp. l31. v ... | 1994 | 7918657 |
| two mutations that block heterocyst differentiation have different effects on akinete differentiation in nostoc ellipsosporum. | evident differentiation of vegetative cells into heterocysts in anabaena sp. strain pcc 7120 is prevented by insertions in genes hetr and hetp. nostoc ellipsosporum possesses single copies of genes that hybridize with hetr and hetp. in mutant ne2 of n. ellipsosporum, in which hetr is interrupted by an insert, and in a double recombinant of wild-type n. ellipsosporum with a plasmid that bears an interrupted copy of hetr, neither heterocysts nor akinetes are formed. when an intact copy of hetr fro ... | 1994 | 7934891 |
| mutational analysis of the nh4+-nitrogen controls that regulate ammonium transport activity, heterocyst differentiation, nitrogenase activity and the heterocyst-spacing pattern in the cyanobacterium nostoc muscorum. | mutational analysis of the genetic determinants mediating nh(4+)-nitrogen regulating effects on nh(4+)-transport activity, heterocyst differentiation, nitrogenase activity and heterocyst pattern formation was carried out in nostoc muscorum. evidence suggested the operation of three separate genetic determinants in such nitrogen control; one mediating nh(4+)-repression control on both heterocyst formation and nh(4+)-transport activity, a second (nif-r) mediating nh(4+)-repression control on nitro ... | 1994 | 8019441 |