Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 physical map of plasmid pdu1 from the cyanobacterium nostoc pcc 7524. | 1982 | 6283572 | |
| new anabaena and nostoc cyanophages from sewage settling ponds. | 1981 | 6269286 | |
| 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 |
| 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 |
| 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 |
| [fixation of molecular nitrogen by some representatives of the genera aanbaena and nostoc]. | 1966 | 5995733 | |
| biosynthesis of alkanes in nostoc muscorum. | 1969 | 5798100 | |
| induction by ultraviolet irradiation of mutation in the blue-green alga nostoc linckia (roth) born. et flah. | 1969 | 5782614 | |
| possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction. | 1969 | 5779919 | |
| fixation of elementary nitrogen by nostoc punctiforme (kütz.) hariot and scytonema bohneri schmidle in pure and unialgal cultures. | 1970 | 5412270 | |
| nitrogen metabolism of nostoc muscorum & phormidiu phormidium fragile. | 1971 | 5004444 | |
| 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 |
| 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 |
| 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 |
| [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 | |
| heterotrophic growth of the nitrogen fixing blue-green alga nostoc muscorum. | 1974 | 4212052 | |
| 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 |
| 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 |
| 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 |
| ultrastructural development of nostoc muscorum a. | 1973 | 4198641 | |
| 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 |
| possible respiratory sites in a blue-green alga nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction. | 1969 | 4181442 | |
| 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 | |
| isolation and characterization of a virus infecting the blue-green alga nostoc muscorum. | 1971 | 4108613 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| effect of insecticides and phenolics on nitrogen fixation by nostoc linckia. | 1988 | 3145048 | |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| analysis of fluorescence kinetics and energy transfer in isolated alpha subunits of phycoerythrin from nostoc sp. | 1986 | 3081920 | |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| distinct fractions of genomic dna from cyanobacterium nostoc commune that differ in the degree of methylation. | 1988 | 2854807 | |
| 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 |
| 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 |
| 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 |
| phycotoxicity of linear alkylbenzene sulfonate. | dose- and time-dependent effects of linear alkylbenzene sulfonate, a major component of synthetic detergent, to the blue-green alga nostoc muscorum, were studied under laboratory conditions. toxicity was evident, at doses above 0.001%, from the decrease in biomass, heterocyst number, and protein content and pathomorphological alterations. | 1988 | 2837383 |
| an analysis of restriction endonuclease sites in cyanophages infecting the heterocystous cyanobacteria anabaena and nostoc. | an analysis of restriction endonuclease cleavage of dna isolated from cyanophages that infect anabaena and nostoc species of cyanobacteria has provided evidence for counter-selection of restriction endonuclease sites. these include sites containing subsequences which are methylated by host (anabaena pcc 7120) methylase(s) akin to the dam and dcm enzymes of escherichia coli. other sites which are counter-selected have no common sequence structure. the latter include those of the endogenous restri ... | 1988 | 2832536 |
| comparison of dna restriction fragment length polymorphisms of nostoc strains in and from cycads. | dna was prepared from cyanobacteria freshly isolated from coralloid roots of natural populations of five cycad species: ceratozamia mexicana mexicana (mexico), c. mexicana robusta (mexico), dioon spinulosum (mexico), zamia furfuraceae (mexico) and z. skinneri (costa rica). using the southern blot technique and cloned anabaena pcc 7120 nifk and glna genes as probes, restriction fragment length polymorphisms of these cyanobacterial symbionts were compared. the five cyanobacterial preparations show ... | 1989 | 2569858 |
| nitrogen fixation (nif) genes of the cyanobacterium anabaena species strain pcc 7120. the nifb-fdxn-nifs-nifu operon. | a second nitrogen fixation (nif) operon in the cyanobacterium (blue-green alga) anabaena (nostoc) sp. strain pcc 7120 has been identified and sequenced. it is located just upstream of the nifhdk operon and consists of four genes in the order nifb, fdxn, nifs, and nifu. the three nif genes were identified on the basis of their similarity with the corresponding genes from other diazotrophs. the fourth gene, fdxn, codes for a bacterial type ferredoxin (mulligan, m. e., buikema, w. j., and haselkorn ... | 1989 | 2553733 |
| nostoc commune utex 584 gene expressing indole phosphate hydrolase activity in escherichia coli. | a gene encoding an enzyme capable of hydrolyzing indole phosphate was isolated from a recombinant gene library of nostoc commune utex 584 dna in lambda gt10. the gene (designated iph) is located on a 2.9-kilobase ecori restriction fragment and is present in a single copy in the genome of n. commune utex 584. the iph gene was expressed when the purified 2.9-kilobase dna fragment, free of any vector sequences, was added to a cell-free coupled transcription-translation system. a polypeptide with an ... | 1989 | 2536677 |
| photosynthetic co2 fixation and ribulose bisphosphate carboxylase/oxygenase activity of nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | the cyanobacterium nostoc sp. strain ucd 7801, immediately after separation from pure cultures of a reconstituted symbiotic association with the bryophyte anthoceros punctatus, exhibited a rate of light-dependent co2 fixation that was eightfold lower than that measured in the free-living growth state. ribulose bisphosphate carboxylase/oxygenase (rubpc/o) specific activity was also eightfold lower in cell extracts of symbiotic strain 7801 relative to that in free-living cultures. the in vitro act ... | 1989 | 2509431 |
| effects of three pesticides on msx-induced ammonia photoproduction by the cyanobacterium nostoc linckia. | three pesticides (2,4-d, basalin, aldrin) inhibited l-methionine-dl-sulfoximine (msx)-induced photoproduction of ammonia by the nitrogen-fixing cyanobacterium nostoc linckia. combinations of pesticides and msx were inhibitory except at low concentrations (100 and 500 micrograms/ml) of 2,4-d which stimulated nh+4 production. similar results were obtained when pesticides were added 6 hr after the addition of msx, but the inhibition was weaker. when msx was added to the culture 6 hr after the addit ... | 1989 | 2509191 |
| novel water stress protein from a desiccation-tolerant cyanobacterium. purification and partial characterization. | a desiccation-tolerant cyanobacterium nostoc commune accumulates a novel group of acidic proteins when colonies are subjected to repeated cycles of drying and rehydration. the proteins occur in high concentrations; they have isoelectric points between 4.3 and 4.8 and apparent molecular masses between 30 and 39 kda. the purification of three of these proteins with molecular masses of 33, 37, and 39 kda is described. the amino-terminal sequence of the 39-kda protein is ala-leu-tyr-gly-tyr-thr-ile- ... | 1989 | 2501307 |
| toxicity of three herbicides to some nitrogen-fixing cyanobacteria. | the effects of some common rice field herbicides, such as 2,4-dichlorophenoxyacetic acid (2,4-d), machete, and saturn, on the paddy field nitrogen-fixing cyanobacteria nostoc linckia, nostoc calcicola, nostoc sp., and anabaena doliolum were studied. these cyanobacteria were found to be more tolerant to 2,4-d (lethal doses 1500-2000 micrograms/ml) than to machete and saturn (lethal doses 6-8 micrograms/ml). the effects of these three herbicides on some physiological processes of n. linckia were s ... | 1989 | 2500323 |
| effect of bimetallic combinations of ni, cr, and pb on growth, uptake of nitrate and ammonia, 14co2 fixation, and nitrogenase activity of nostoc muscorum. | the toxicity of cr, ni, and pb individually as well as in combination (cr + ni, cr + pb, ni + pb) on growth, final yield, uptake of no3- and nh4+, photosynthesis, and nitrogenase activity of nostoc muscorum has been studied. all test metals, when used individually, depicted toxicity against the above-mentioned processes of test cyanobacterium. however, their interactive effect was found to be mostly of antagonistic type. antagonism was more prevalent in those combinations containing nickel. in a ... | 1989 | 2496971 |
| cyanobacterial rna polymerase genes rpoc1 and rpoc2 correspond to rpoc of escherichia coli. | the dna-dependent rna polymerase (ribonucleoside triphosphate:rna nucleotidyltransferase, ec 2.7.7.6) of cyanobacteria contains a unique core component, gamma, which is absent from the rna polymerases of other eubacteria (g. j. schneider, n. e. tumer, c. richaud, g. borbely, and r. haselkorn, j. biol. chem. 262:14633-14639, 1987). we present the complete nucleotide sequence of rpoc1, the gene encoding the gamma subunit, from the heterocystous cyanobacterium nostoc commune utex 584. the derived a ... | 1989 | 2495268 |
| polysome turnover in immobilized cells of nostoc commune (cyanobacteria) exposed to water stress. | water stress induced changes in the polysome content of immobilized cells of the desiccation-tolerant cyanobacterium nostoc commune utex 584. cells maintained an intact protein synthesis complex during 2 h of drying at -99.5 mpa. polysomes were not recovered from cells subjected to extended periods of desiccation. | 1986 | 2430937 |
| cytotoxic, antiviral indolocarbazoles from a blue-green alga belonging to the nostocaceae. | 6-cyano-5-methoxy-12-methylindolo[2,3-alpha]carbazole and 6-cyano-5-methoxyindolo[2,3-alpha]carbazole are responsible for most of the cytotoxicity and antiviral activity associated with the blue-green alga nostoc sphaericum ex-5-1. the compounds are active against hsv ii and show weak cytotoxicity against kb and lovo human carcinoma cell lines. | 1990 | 2175302 |
| chemical composition, in vitro protein digestibility and in vitro available iron of blue green alga, nostoc commune. | blue-green alga, nostoc commune, contained moderate amounts of protein and iron. its in vitro protein digestibility was 43.50%. the soluble and ionic iron from the alga was extractable to some extent at ph 1.5 but was not detectable at ph 8.0. the digestion by protease did not affect the iron detection. heat processing at 100 and 120 degrees c failed to increase the digestibility and the content of available iron. the dietary fiber in the alga may be responsible for low protein digestion and low ... | 1990 | 2170966 |
| identification of a periplasmic c-type cytochrome as electron donor to the plasma membrane-bound cytochrome oxidase of the cyanobacterium nostoc mac. | photoautotrophically grown cyanobacterium nostoc sp. strain mac (pcc 8009) released up to about 10 nmol of a c-type cytochrome per ml packed cells after treatment with edta under conditions that left the plasma membrane absolutely intact as judged from the absence of cytosolic proteins in the supernatant. spectra of the ascorbate reduced cytochrome revealed peaks at 553, 522 and 416 nm. the protein was purified to an a-553/a-275 ratio of 0.8. midpoint potential (at ph 7), isoelectric point and a ... | 1990 | 2162667 |
| isolation and characterization of hepatotoxic microcystin homologs from the filamentous freshwater cyanobacterium nostoc sp. strain 152. | a strain of the filamentous cyanobacterium nostoc sp. isolated from a lake in finland was found to produce at least nine hepatotoxic peptides with chemical and toxicological properties similar to those of the hepatotoxic hepta- and pentapeptides produced by other cyanobacteria. toxins were isolated and purified by high-performance liquid chromatography. amounts available for five of the purified toxins (p6, p14, p15, p16, and p18) were adequate for high-performance liquid chromatography amino ac ... | 1990 | 2125813 |
| reconstitution of electron transport in photosystem i with psac and psad proteins expressed in escherichia coli. | a fusion protein, denoted psac1, which contains an amino-terminal extension of five amino acids (mehsm...) and is derived from an in vitro modified form of the psac gene of synechococcus sp. pcc 7002, has been over-expressed in escherichia coli. the product of the psad gene of nostoc sp. pcc 8009 has similarly been over-expressed. the psac1 and psad proteins can be combined with the photosystem i core protein of synechococcus sp. pcc 6301 to reconstitute electron transport from p700 to the termi ... | 1990 | 2125006 |
| immunologically cross-reactive and redox-competent cytochrome b6/f-complexes in the chlorophyll-free plasma membrane of cyanobacteria. | plasma and thylakoid membranes were separated and purified from cell-free extracts of the cyanobacteria anacystis nidulans, synechocystis 6714, anabaena variabilis and nostoc sp. strain mac. immunoblots of the membrane proteins using antisera raised against subunits i-iv of the chloroplast b6/f-complex gave evidence for the presence of a homologous complex in both plasma and thylakoid membranes from the four species of cyanobacteria investigated. both plasma and thylakoid membranes catalyzed the ... | 1990 | 2121543 |
| structural and chemical properties of a flavodoxin from anabaena pcc 7119. | structural and chemical properties of a flavodoxin from anabaena pcc 7119 are described. the first 36 residues of the amino-terminal amino acid sequence have been determined and show extensive homology with flavodoxins isolated from other sources. anabaena flavodoxin exhibits a net negative change (-3) in the helix-1 segment as found with other cyanobacterial flavodoxins synechococcus 6301 (anacystis nidulans) and nostoc mac, but in contrast to the net positive charge found in this region in the ... | 1990 | 2119231 |
| genetic transformation of glutamine auxotrophy to prototrophy in the cyanobacterium nostoc muscorum. | glutamine auxotrophic (gln-) and l-methionine d,l-sulfoximine (msx) resistant (msxr) mutants of n. muscorum were isolated and characterized for nitrogen nutrition, nitrogenase activity, glutamine synthetase (gs) activity and glutamine amide, alpha-keto-glutarate amido transferase (gogat) activity. the glutamine auxotroph was found to the gogat-containing gs-defective, incapable of growth with n2 or nh4+ but capable of growth with glutamine as nitrogen source, thus, suggesting gs to be the primar ... | 1990 | 1978772 |
| effect of four heavy metals on the biology of nostoc muscorum. | this study presents the effects of cr, pb, ni and ag on growth, pigments, protein, dna, rna, heterocyst frequency, uptake of nh4+ and no3-, loss of electrolytes (na+ and k+), nitrate reductase and glutamine synthetase activities of nostoc muscorum. the statistical tests revealed a direct positive correlation between the metal concentration and inhibition of different processes. ni was found to be more toxic against growth, pigments and heterocyst differentiation compared to the other metals. inh ... | 1990 | 1975195 |
| binding of cadmium by cyanobacterial growth media: free ion concentration as a toxicity index to the cyanobacterium nostoc uam 208. | a quantitative study of cadmium binding to three different growth media for nitrogen-fixing cyanobacteria was done with the aid of a solid state ion-specific electrode. kratz and myers modified medium and arnon medium bound large amounts of cd2+, bg11o medium had less binding capacity. of the media components, phosphate ion showed the greatest ability to bind cd2+. different phs, the size of cell inoculum and two buffers (tricine and hepes, 25 mm) also changed the availability of free cadmium io ... | 1991 | 1953030 |
| physiological sources of reductant for nitrogen fixation activity in nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | pure cultures of the symbiotic cyanobacterium-bryophyte association with anthoceros punctatus were reconstituted by using nostoc sp. strain ucd 7801 or its 3-(3,4-dichlorophenol)-1,1-dimethylurea (dcmu)-resistant mutant strain, ucd 218. the cultures were grown under high light intensity with co2 as the sole carbon source and then incubated in the dark to deplete endogenous reductant pools before measurements of nitrogenase activities (acetylene reduction). high rates of light-dependent acetylene ... | 1991 | 1938924 |
| growth, chlorophyll a content, nitrogen-fixing ability, and certain metabolic activities of nostoc muscorum: effect of methylparathion and benthiocarb. | 1991 | 1932863 | |
| the amino-acid sequence of three proteins of photosystem i of the cyanobacterium fremyella diplosiphon (calothrix sp pcc 7601). | three proteins containing 138 amino acids (psad protein), 80 amino acids (psac protein) and 66 amino acids (psae protein) of the photosystem i (ps i) complex of the cyanobacterium fremyella diplosiphon (calothrix sp pcc 7601) were isolated and sequenced. comparison with previously known sequences showed a close relationship to homologous proteins of nostoc, another filamentous cyanobacterium. | 1991 | 1930733 |
| response of enzymes involved in the processes of antioxidation towards benthiocarb and methylparathion in cyanobacteria nostoc muscorum. | 1991 | 1912703 | |
| orientation and linear dichroism of mastigocladus laminosus phycocyanin trimer and nostoc sp. phycocyanin dodecamer in stretched poly(vinyl alcohol) films. | the linear dichroism (ld) spectra of the c-phycocyanin (c-pc) trimer disks oriented in poly(vinyl alcohol) films (pva) at room temperature and at 95 k were determined. utilizing the known atomic coordinates of the chromophores (schirmer, t., bode, w. and huber, r. (1987) j. mol. biol. 196, 677-695) and theoretical estimates of the orientations of the transition dipole moments relative to the molecular framework, the ld spectra were simulated using the pairwise exciton interaction model of sauer ... | 1991 | 1905956 |
| cadmium toxicity to photosynthesis and associated electron transport system of nostoc linckia. | 1991 | 1900451 | |
| gene cluster rpobc1c2 in cyanobacteria does not constitute an operon. | the core enzyme of the cyanobacterial dna-dependent rna polymerase contains a unique component, gamma, which is absent from the corresponding enzymes of other eubacteria. in the heterocystous cyanobacterium nostoc commune the gene encoding gamma, rpoc1, is immediately adjacent to, and downstream of, rpob. the rpoc1 gene, and a 3' adjacent gene, rpoc2, correspond to the single rpoc gene found in escherichia coli with respect to those domains conserved within their translational products. northern ... | 1991 | 1899176 |
| sequence-specific endonucleases from the cyanobacterium nostoc sp. atcc 29132. | the nitrogen-fixing cyanobacterium nostoc sp. atcc 29132 was shown to contain two sequence-specific endonucleases. nsp(29132) i was an isoschizomer of asuii, and nsp(29132) ii was an isoschizomer of bamhi. nsp(29132) ii was shown to generate ends that could be ligated to those generated by bamhi. | 1991 | 1840140 |
| [production of the antibiotic-algicide cyanobacterin lu-2 by a filamentous cyanobacterium nostoc sp]. | a strain of cyanobacterium of nostoc has been isolated, and found to produce a new antibiotic cyanobacterin lu-2. the antibiotic is synthesized by the cyanobnacterium under intensive cultivation conditions in a liquid mineral medium. cyanobacterin lu-2 is an exometabolite; its maximum accumulation in the medium is achieved at 34 degrees. cyanobacterin lu-2 is active against many cyanobacteria tested, including those of microcystis and aphanizomenon which are principals to give rise to blooms in ... | 1991 | 1819038 |
| effect of lead on nitrogenase and enzymes of nitrogen assimilation in a cyanobacterium nostoc muscorum. | lead decreased the growth rates, total cell mass, heterocyst frequency, total cell protein, nitrogenase activity, glutamine synthetase (gs) and glutamate synthase (gogat) activities in n:muscorum. however, lead at 0.01 and 10 micrograms ml-1 conc. enhanced nitrogenase as well as gs activity of the cells. on transfer to excess lead (100 micrograms ml-1), nitrogenase and gs activities ceased almost after 24 hr in the cyanobacterium. it is deduced that lead has a two step effect on stimulation and ... | 1991 | 1816095 |
| evidence for energy-dependent copper efflux as a mechanism of cu2+ resistance in the cyanobacterium nostoc calcicola. | wild-type nostoc calcicola carried out oxygenic photosynthesis extremely sensitive to copper. a cu(2+)-resistant mutant (cu-r1) of the cyanobacterium grew normally at high concentrations of cu2+. its ability to grow under such conditions was found to be due to mutational acquisition of an energy-dependent efficient system of cu(2+)-efflux, which rendered cu(2+)-inhibited oxygenic photosynthesis fully reversible. | 1991 | 1804762 |
| evidence for a role of glutamine synthetase in assimilation of amino acids as nitrogen source in the cyanobacterium nostoc muscorum. | methylammonium/ammonium ion, glutamine, glutamate, arginine and proline uptake, and their assimilation as nitrogen sources, was studied in nostoc muscorum and its glutamine synthetase-deficient mutant. glutamine served as nitrogen source independent of glutamine synthetase activity. glutamate was not metabolised as a nitrogen source but still inhibited nitrogenase activity and diazotrophic growth. glutamine synthetase activity was essential for the assimilation of n2, ammonia, arginine and proli ... | 1991 | 1687107 |
| influence of different forms of nitrogen on uptake of ammonium, glutamate and glutamine in the cyanobacterium nostoc muscorum. | effect of various types of nitrogen nutrition was studied on the uptake of ammonium, glutamate and glutamine by nostoc muscorum and its het-nif- mutant. ammonium nitrogen acted as a potent inhibitor/repressor of ammonium, glutamate and glutamine transport. nitrate nitrogen was found to be a strong inhibitor/repressor of ammonium transport, a partial inhibitor/repressor of glutamate transport but, caused a partial stimulation of glutamine transport. | 1991 | 1684351 |
| psad is required for the stable binding of psac to the photosystem i core protein of synechococcus sp. pcc 6301. | the psac gene product from synechococcus sp. pcc 7002 and the psad gene product from nostoc sp. pcc 8009 were synthesized in escherichia coli and purified to homogeneity. incubation of the psac apoprotein with the synechoccus sp. pcc 6301 photosystem i core protein in the presence of fecl3, na2s, and beta-mercaptoethanol resulted in a time-dependent transition in the flash-induced absorption change from a 1.2-ms, p700+ fx- back-reaction to a long-lived, p700+ [fa/fb]- back-reaction. esr studies ... | 1991 | 1651109 |
| [2 site-specific endonucleases of the cyanobacterium nostoc linckia]. | two restrictases nli387/7 i and nli387/7 ii have been isolated from cyanobacterium nostoc linckia using chromatography on phosphocellulose, "mono q" column, and heparin sepharose 4b. the preparations are described by the method of electrophoresis in polyacrylamide gel under denaturing conditions. catalytic properties of restrictases are determined: optimal ph of the action--9.0--9.5, optimal concentration of na+--5 mm, that of mg2+--6 mm, optimal temperature--37 degrees c. the isolated enzymes a ... | 1991 | 1650423 |
| myoglobin in a cyanobacterium. | myoglobin was found in the nitrogen-fixing cyanobacterium nostoc commune. this cyanobacterial myoglobin, referred to as cyanoglobin, was shown to be a soluble hemoprotein of 12.5 kilodaltons with an amino acid sequence that is related to that of myoglobins from two lower eukaryotes, the ciliated protozoa paramecium caudatum and tetrahymena pyriformis. cyanoglobin is encoded by the glbn gene, which is positioned between nifu and nifh-two genes essential for nitrogen fixation-in the genome of nost ... | 1992 | 1609281 |
| molecular cloning and sequencing of the beta-isopropylmalate dehydrogenase gene from the cyanobacterium spirulina platensis. | the gene for beta-isopropylmalate dehydrogenase (ec 1.1.1.85) of spirulina platensis (leub) was cloned from a lambda embl3 genomic library by heterologous hybridization using the nostoc ucd 7801 leub gene as a probe. the sequence of the entire leub coding region was determined as well as 645 bp of 5' flanking region and 956 bp of 3' flanking region. dna sequencing revealed an open reading frame of 1065 nucleotides capable of encoding a polypeptide of 355 amino acids. homologies between the amino ... | 1992 | 1593261 |
| construction of insertion mutants of synechocystis sp. pcc 6803: evidence for an essential function of subunit iv of the cytochrome b6/f complex. | the gene encoding subunit iv of the cytochrome b6/f complex (petd) has been isolated from a genomic library of the unicellular cyanobacterium synechocystis sp. pcc 6803. the coding region consists of 480 nucleotides and can code for a polypeptide with a molecular weight of 17.5 kda. the deduced amino acid sequence shows high identity with the corresponding sequences of both the photoautotrophic prokaryote nostoc sp. pcc 7906 as well as of lower and higher photoautotrophic eukaryotes (e.g. chlore ... | 1992 | 1590707 |
| differentiation of free-living anabaena and nostoc cyanobacteria on the basis of fatty acid composition. | the cellular fatty acids of free-living, nitrogen-fixing cyanobacteria belonging to the genera anabaena and nostoc were analyzed to differentiate the genera. the fatty acid compositions of 10 anabaena strains and 10 nostoc strains that were grown for 12 days on bg-11o medium were determined by gas-liquid chromatography-mass spectroscopy. of the 53 fatty acids detected, 17 were major components; the average level for each of these 17 fatty acids was at least 0.9% of the total fatty acids (in at l ... | 1992 | 1581185 |
| differential effect of ultraviolet-b radiation on certain metabolic processes in a chromatically adapting nostoc. | the impact of uv-b radiation on growth, pigmentation and certain physiological processes has been studied in a n2-fixing chromatically adapting cyanobacterium, nostoc spongiaeforme. a brownish form (phycoerythrin rich) was found to be more tolerant to uv-b than the blue-green (phycocyanin rich) form of n. spongiaeforme. continuous exposure to uv-b (5.5 w m-2) for 90 min caused complete killing of the blue-green strain whereas the brown strain showed complete loss of survival after 180 min. pigme ... | 1992 | 1561238 |
| identification of a second psac gene in the cyanobacterium synechocystis sp. pcc6803. | the psac gene encodes the 9 kda protein subunit of photosystem i that carries the iron-sulfur centers fa and fb. the paper describes the sequence and transcription analysis of a second psac gene (psac2) from synechocystis sp. pcc6803. thepsac2 gene is transcribed into an abundant monocistronic mrna. the deduced amino acid sequence of psi-c2 is very similar to the protein sequences from two other cyanobacteria (synechococcus sp. pcc7002 and nostoc sp. pcc8009). in contrast, the recently isolated ... | 1992 | 1463835 |
| semipreparative isolation of individual cyanobacterial heterocyst-type glycolipids by reverse-phase high-performance liquid chromatography. | procedures are described for the quantitative, semi-preparative isolation of individual cyanobacterial heterocyst-type glycolipids (hgs) by reverse-phase hplc (rp-hplc) and the modifications to conventional techniques necessary to prevent significant hg losses during sample preparation. total lipids are obtained from cultures of nitrogen-fixing cyanobacteria by triplicate extraction with 200 packed-cell volumes of chloroform/methanol (1/1, v/v), filtered, and redissolved in chloroform for loadin ... | 1992 | 1443590 |
| cloning and sequencing of the petbd operon from the cyanobacterium synechococcus sp. pcc 7002. | the genes encoding the photosynthetic cytochrome b6 (petb) and subunit 4 (petd) have been cloned and sequenced from the unicellular, photoheterotrophic, transformable cyanobacterium synechococcus sp. pcc 7002, formerly designated agmenellum quadruplicatum. the gene arrangement was found to be similar to that reported in the cyanobacterium nostoc pcc 7906. the dna and derived protein sequences were compared to chloroplast and the other cyanobacterial sequences. by pulsed-field electrophoresis, th ... | 1992 | 1421151 |
| nucleotide sequence of the replication region of the nostoc pcc 7524 plasmid pdu1. | 1992 | 1408769 |