| 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 |
| abscisic acid and its synthetic analog in relation to growth and nitrogenase activity of azotobacter chroococcum and nostoc muscorum. | the plant hormone abscisic acid as well as its synthetic analog lab 173711 significantly increased the nitrogenase activity of the bacterium azotobacter chroococcum and the cyanobacterium nostoc muscorum. the effect depended on the concentration of the substances (0.001-10 mg/l) and the age of the cultures. the biomass of the organisms was not significantly influenced. | 1992 | 1387101 |
| protective effects of ca2+, mg2+, cu2+, and ni2+ on mercury and methylmercury toxicity to a cyanobacterium. | toxicological investigations of the impact of inorganic mercury (hg2+) and methylmercury (ch3hg+) in terms of growth, nh4+ uptake, in vivo glutamine synthetase (transferase) activity, and regulation of toxicity by ca2+, mg2+, cu2+ and ni2+ in the diazotrophic cyanobacterium nostoc calcicola bréb. have been completed. photoautotrophic growth of the cyanobacterium was extremely sensitive to both mercury compounds, ch3hg+ being 2.5 times more toxic than hg2+. although nh4+ uptake was 6 times more s ... | 1992 | 1375141 |
| 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 |
| 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 |
| 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 |
| 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 |
| cadmium toxicity to photosynthesis and associated electron transport system of nostoc linckia. | | 1991 | 1900451 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |