Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| increased content of cytochromes 554 and 562 in anabaena variabilis cells grown in the presence of diphenylamine. | 1971 | 4994399 | |
| heterocyst formation and nitrogenase synthesis in anabaena sp. a kinetic study. | 1971 | 4994860 | |
| absence of histone in the blue-green alga anabaena cylindrica. | 1971 | 4996297 | |
| pigment variations in ultraviolet-treated strains of the blue-green alga anabaena doliolum. | 1971 | 4996686 | |
| apparent lack of control by repression of arginine metabolism in blue-green algae. | five anabolic and two catabolic enzymes of arginine metabolism were neither repressed nor induced after inclusion of arginine in the growth medium of anabaena variabilis. | 1971 | 4998248 |
| the effect of caffeine and light on killing of the blue-green alga anabaena doliolum by ultraviolet radiation. | 1971 | 4998568 | |
| complementary functioning of nitrogenase components from a blue-green alga and a photosynthetic bacterium. | nitrogenases from anabaena cylindrica and chloropseudomonas ethylicum were partially purified into two components. a. cylindrica fraction i protein complemented fraction ii protein from c. ethylicum. however, the reciprocal cross between c. ethylicum fraction i and a. cylindrica fraction ii was negative. | 1971 | 5000308 |
| the biosynthesis of tocopherols and related compounds in the blue-green alga anabaena variabilis. | 1971 | 5001421 | |
| relationship between phosphates and alkaline phosphatase of anabaena flos-aquae in continuous culture. | 1971 | 5001948 | |
| localization of nitrogen fixation in anabaena. | 1971 | 5002029 | |
| nitrogenase activity and nitrogen assimilation in anabaena flos-aquae growing in continuous culture. | 1971 | 5002351 | |
| kinetics of synthesis of nitrogenase in batch and continuous culture of anabaena flos-aquae. | 1971 | 5002352 | |
| pyruvate: ferredoxin oxidoreductase and its activation by atp in the blue-green alga anabaena variabilis. | 1971 | 5002355 | |
| physiology of heterocyst production in the blue-gree alga anabaena doliolum. i. nitrate and light controls. | 1971 | 5005055 | |
| physiology of heterocyst production in the blue-green alga anabaena doliolum. ii. effects of ultraviolet light. | 1971 | 5005056 | |
| [a uniform suspension of an inoculum of the blue-green alga anabaena variabilis]. | 1971 | 5005126 | |
| protein aggregation in c-phycocyanin. studies at very low concentrations with the photoelectric scanner of the ultracentrifuge. | solutions of c-phycocyanin of very low concentrations were examined by sedimentation-velocity studies in the spinco model e ultracentrifuge equipped with a photoelectric scanning system and a monochromator. at sufficiently low concentrations complete disaggregation from the hexamer to the monomer was observed. the equilibrium constant of monomer to hexamer was estimated to be approx. 10(30). for studies of aggregation over the complete range of concentration, c-phycocyanins from phormidium lurid ... | 1971 | 5123877 |
| a light-dependent oxygen-reducing system from anabaena variabilis. | 1970 | 5416113 | |
| [hydrogen and electron transfer to nitrate of anabaena variabilis 359]. | 1970 | 5517669 | |
| c-phycocyanin and allophycocyanin in two species of blue-green algae. | 1. the biliproteins c-phycocyanin and allophycocyanin were purified from the blue-green alga anabaena variabilis by ammonium sulphate fractionation and gel filtration. 2. an assay procedure that enabled the proportion of the two pigments, present as a mixture, to be determined was devised by using the data provided by spectrophotometric analysis of the purified biliproteins. 3. the degree of association and relative proportions of the two pigments were analysed by the application of this procedu ... | 1968 | 5637347 |
| the electrodialysis of anabaena flos-aquae a-37. | 1968 | 5641916 | |
| photochemically active chromoprotein isolated from the blue-green alga anabaena cylindrica. | 1968 | 5677430 | |
| threonine deaminase and acetolactate synthetase in anabaena variabilis. | 1968 | 5679382 | |
| studies on morphogenesis in a blue-green alga. i. effect of inorganic niteogen sources on developmental morphology of anabaena doliolum. | 1968 | 5710271 | |
| movement of carbon from vegetative cells to heterocysts in anabaena cylindrica. | radioactive carbon assimilated by vegetative cells of anabaena cylindrica in the light passed via an intrafilamentous route into heterocysts in the dark. after several hours, label per heterocyst approximated label per vegetative cell. much of the label entering heterocysts was not available for diffusional exchange back into vegetative cells. | 1968 | 5724976 |
| properties and structure of fractions prepared from anabaena variabilis by the action triton x-100. | 1969 | 5775692 | |
| the incomplete tricarboxylic acid cycle in the blue-green alga anabaena variabilis. | 1969 | 5783887 | |
| a fraction from anabaena variabilis enriched in the reaction center chlorophyll p700. | 1969 | 5795473 | |
| extracellular nitrogen and the control of arginine biosynthesis in anabaena variabilis. | 1969 | 5810045 | |
| light induced redox reactions of cytochrome c by cell-free preparation of anabaena cylindrica. | 1965 | 5834711 | |
| reduction of phenolindo-2,6-dichlorophenol in dark and light by the blue-green alga, anabaena variabilis. | 1965 | 5864529 | |
| [algicidal properties of aquatic and shore plants of the kremenchug reservoir with respect to the blue-green algae microcystis pulverea and anabaena hassalii]. | 1965 | 5869328 | |
| biosynthesis of extracellular polysaccharides by the blue-green alga anabaena flos-aquae. | 1965 | 5879502 | |
| the 2,6-dichlorophenol indophenol-hill reaction by a cell-free preparation of anabaena cylindrica. | 1965 | 5880152 | |
| light-induced cytochrome c redox reactions by a cell-free preparation of anabaena cylindrica. | 1965 | 5880153 | |
| metabolic activities of isolated heterocysts of the blue-green alga anabaena cylindrica. | 1966 | 5925344 | |
| cytochrome c redox reactions induced by photochemical system 1 in sonicated preparations of anabaena cylindrica. | 1966 | 5944972 | |
| reduction of nitrate and nitrite by subcellular preparations of anabaena cylindrica. i. reduction of nitrite to ammonia. | reduction of nitrite by cell-free preparations of anabaena cylindrica in the dark has been investigated. nitrite-reducing activity was recovered in a supernatant fraction. the nitrite reductase system was partially purified by column chromatography on sephadex g-75. nadph could serve as an h-donor. nadh was completely inactive. the reduction required ferredoxin which mediated the transfer of electrons from nadph to nitrite. ferredoxin was successfully replaced with methyl viologen, benzyl violog ... | 1966 | 5945126 |
| photochemical reduction of elemental nitrogen by anabaena flos-aquae a37. | 1966 | 5970131 | |
| physiological studies on nitrogen fixation in the blue-green alga anabaena cylindrica. | 1966 | 5989525 | |
| [on the mineral nutrition of anabaena variabilis]. | 1966 | 5993609 | |
| ribosomes from the blue-green alga anabaena variabilis. | 1967 | 6049373 | |
| kinetic analysis of light-induced cytochrome c redox reactions in anabaena lamellar fragments. | 1967 | 6052456 | |
| the metabolism of acetate by the blue-green algae, anabaena variabilis and anacystis nidulans. | 1967 | 6077932 | |
| cotranscription of genes encoding the small and large subunits of ribulose-1,5-bisphosphate carboxylase in the cyanobacterium anabaena 7120. | in the filamentous cyanobacterium anabaena, the gene for the small subunit (rbcs) of ribulose-1,5-bisphosphate carboxylase is linked to and transcribed together with the gene encoding the large subunit (rbcl) of the same enzyme. the two genes are separated by a spacer of 545 base pairs (bp) that does not contain an open reading frame. both genes hybridize with a predominant 3.1-kilobase transcript that initiates 414 bp upstream from the rbcl coding region. the nucleotide sequence 14-8 bp precedi ... | 1984 | 6091125 |
| infrequent cleavage of cloned anabaena variabilis dna by restriction endonucleases from a. variabilis. | a cosmid vector has been constructed, using a lambda replicon. a library of cosmids from anabaena variabilis atcc 29413 based on use of this vector is shown to be highly deficient in sites for the two type ii restriction endonucleases found in that organism. | 1984 | 6094490 |
| isolation and characterization of thioredoxin f from the filamentous cyanobacterium, anabaena sp. 7119. | two thioredoxin fractions had previously been reported to occur in anabaena 7119 by buchanan and co-workers (yee, b. c., dela torre, a., crawford, n. a., lara, c., carlson, d. e., and buchanan, b. b. (1981) arch. microbiol. 130, 14-18). these proteins were detected by their ability to activate spinach fructose-1,6-bisphosphatase (fru-p2-ase). the partially purified proteins resembled similar thioredoxins found in spinach chloroplasts and were designated thioredoxin f (tf) for the fraction most e ... | 1984 | 6094540 |
| novel mutant of anabaena sp. strain ca which growns on n2 but not on combined nitrogen. | a mutant has been isolated from anabaena sp. strain ca by treatment with n-methyl-n'-nitro-n-nitrosoguanidine, which has the unusual phenotypic characteristic of growth only under n2-fixing conditions. growth of the mutant was completely inhibited by no3- or nh4+ at concentrations routinely used for growth of the wild type, and sensitivity to nh4+ was especially pronounced. the inhibitory effect of nh4+ could not be overcome by glutamine, glutamate, or casein hydrolysate. ammonia had no immediat ... | 1980 | 6106012 |
| regulation of glutamine synthetase in the blue-green alga anabaena flos-aquae. | 1980 | 6107080 | |
| regulation of glutamine synthetase in the blue-green alga anabaena l-31. | in n2-grown cultures of anabaena l-31, in which protein synthesis was prevented by chloramphenicol, presence of nh+4 caused a drastic decrease of glutamine synthetase (l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2) activity indicating nh+4-mediated inactivation or degradation of the enzyme. the half-life of glutamine synthetase was more than 24 h, whereas that of nitrogenase (reduced ferredoxin:dinitrogen oxidoreductase (atp-hydrolysing), ec 1.18.2.1) was less than 4 h, suggesting that gl ... | 1980 | 6108785 |
| in vivo regulation of glutamine synthetase by ammonium in the cyanobacterium anabaena l-31. | 1981 | 6111293 | |
| a cloned cyanobacterial gene for glutamine synthetase functions in escherichia coli, but the enzyme is not adenylylated. | the coding sequence for anabaena 7120 glutamine synthetase [l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.1] are shown to be contained within a 7.5-kilobase-pair (kbp) hindiii fragment that has been cloned by plaque hybridization. the hybridization probe for the cyanobacterial gene was a recombinant plasmid containing the glna gene from escherichia coli k-12. evidence that the cloned anabaena fragment contains the glna gene includes complementation of a glna deletion mutant of e. coli and i ... | 1981 | 6115380 |
| regulatory isozymes of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase in the cyanobacterium anabaena sp. strain atcc 29151. | two regulatory isozymes of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase from the cyanobacterium anabaena sp. strain atcc 29151 were separated via gel filtration. one isozyme (mr = 205,000) was sensitive to phenylalanine inhibition, and the other (mr = 60,000) was sensitive to tyrosine inhibition. the tyrosine-sensitive isozyme from wild-type cells was unstable to gel filtration, whereas the corresponding isozyme from an analog-resistant mutant was insensitive to tyrosine inhibition and wa ... | 1981 | 6116697 |
| detection of glutamate synthase in heterocysts of anabaena sp. strain 7120. | the formation of [(14)c]glutamate from [(14)c]glutamine in the presence of alpha-oxoglutarate was observed in extracts of heterocysts of anabaena sp. strain 7120 under conditions that indicate the operation of glutamate synthase. | 1981 | 6118357 |
| purification, physical characterization, and nh2-terminal sequence of glutamine synthetase from the cyanobacterium anabaena 7120. | a procedure for the complete purification of glutamine synthetase (l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2) from the cyanobacterium (blue-green alga) anabaena 7120 is described. the enzyme has structural characteristics in common with glutamine synthetases from other sources: a subunit molecular weight of approximately 50,000 and a native structure, determined by low dose exposure electron microscopy, consisting of a two-layered regular hexagon made up of 12 subunits. sequence analy ... | 1981 | 6118370 |
| kinetic and inhibition studies of glutamine synthetase from the cyanobacterium anabaena 7120. | a number of biochemical parameters of glutamine synthetase (ec 6.3.1.2) isolated from the cyanobacterium anabaena 7120 were determined. apparent michaelis constants for glutamate and atp were found to be 2.1 and 0.32 mm, respectively; that for ammonia was found to be below 20 microm, significantly lower than that reported for glutamine synthetases from other species. serine, alanine, glycine, cysteine, aspartic acid, methionine sulfone, and methionine sulfoximine were found to inhibit the enzyme ... | 1981 | 6118371 |
| biochemical diversity for biosynthesis of aromatic amino acids among the cyanobacteria. | we examined the enzymology and regulatory patterns of the aromatic amino acid pathway in 48 strains of cyanobacteria including representatives from each of the five major grouping. extensive diversity was found in allosteric inhibition patterns of 3-deoxy-d-arabinoheptulosonate 7-phosphate synthase, not only between the major groupings but also within several of the generic groupings. unimetabolite inhibition by phenylalanine occurred in approximately half of the strains examined; in the other s ... | 1982 | 6119309 |
| regulation of glutamine synthetase activity and synthesis in free-living and symbiotic anabaena spp. | regulation of the synthesis and activity of glutamine synthetase (gs) in the cyanobacterium anabaena sp. strain 7120 was studied by determining gs transferase activity and gs antigen concentration under a variety of conditions. extracts prepared from cells growing exponentially on a medium supplemented with combined nitrogen had a gs activity of 17 mumol of gamma-glutamyl transferase activity per min per mg of protein at 37 degrees c. this activity doubled in 12 h after transfer of cells to a ni ... | 1982 | 6127334 |
| evidence for ammonia as an inhibitor of heterocyst and nitrogenase formation in the cyanobacterium anabaena cycadeae. | growth and regulation of heterocyst and nitrogenase by fixed nitrogen sources were studied comparatively in parent and glutamine auxotrophic mutant of anabaena cycadeae. the parent strain grew well on n2, nh+4 or glutamine while the mutant strain grew on glutamine but not on n2 or nh+4. the total lack of active glutamine synthetase in the mutant strain thus appears to be the reason for its observed lack of growth in n2 or nh+4, which explains why it is a glutamine auxotroph and at the same time ... | 1983 | 6131672 |
| 14c-labeled metabolites in heterocysts and vegetative cells of anabaena cylindrica filaments and their presumptive function as transport vehicles of organic carbon and nitrogen. | to investigate the transport of primary metabolites in anabaena cylindrica from vegetative cells into heterocysts, intact filaments were labeled with the heterocysts were separated from the vegetative cells after different time intervals, and the labeling patterns were determined. after a 20-s fixation time, a high percentage of labeling of alanine, glutamate and glutamine, and, to a lesser extent, glucose 6-phosphate was found in heterocysts as compared with whole filaments. the results can be ... | 1983 | 6135688 |
| the role of specific cations in regulation of cyanobacterial glutamine synthetase. | purified glutamine synthetase from the cyanobacterium anabaena cylindrica required a divalent cation for activity. maximum biosynthetic activity required mg2+ (25 mm when supplied alone). co2+ and mn2+ each supported up to 20% of this activity; 12 other cations tested were ineffective. at 2.5 - 10 mm mg2+, 0.1 mm co2+ or ethylene glycol-bis-(beta-aminoethyl ether) n,n'-tetraacetic acid (egta) stimulated gs activity to maximum rates; other divalent cations (particularly mn2+) inhibited mg2+-depen ... | 1983 | 6136275 |
| glutamine and glutamate transport by anabaena variabilis. | anabaena variabilis, a dinitrogen-fixing cyanobacterium, has high- and low-affinity systems for the transport of glutamine and glutamate. the high-affinity systems have km values of 13.8 and 100 microm and maximal rates of 13.2 and 14.4 nmol x min-1 x mg of chlorophyll a-1 for glutamine and glutamate, respectively. the low-affinity systems have km values of 1.1 and 1.4 mm and maximal rates of 125 and 100 nmol x min-1 x mg of chlorophyll a-1 for glutamine and glutamate, respectively. glutamine wa ... | 1983 | 6137473 |
| organization and transcription of genes important in anabaena heterocyst differentiation. | the structural genes for nitrogenase and nitrogenase reductase have been cloned from anabaena and physically mapped. the map differs from that of klebsiella in several ways, including the insertion of 11 kbp between nifk and nifd in anabaena. one nif rna transcript has been studied in detail and shown to originate from a site in the anabaena chromosome which lacks good correspondence with a typical prokaryotic strong promoter, suggesting the possibility of a need for positive activation. the nif ... | 1983 | 6139054 |
| purification and characterization of thioredoxin from the n2-fixing cyanobacterium anabaena cylindrica. | thioredoxin has been purified to homogeneity from the cyanobacterium anabaena cylindrica. the protein consists of a single polypeptide chain with a relative molecular mass of about 11 680 which has two cysteine residues (residues 31 and 34) in the sequence-cys-gly-pro-cys- and an isoelectric point at ph 4.55. the n-terminal amino acid sequence of 39 residues shows distinct homologies with the sequences of escherichia coli and corynebacterium nephridii thioredoxins. anti-(a. cylindrica thioredoxi ... | 1984 | 6146520 |
| [carbon dioxide fixation and its regulation in synechococcus (anacystis nidulans) cyanobacteria]. | the bulk of 14co2 assimilated in photosynthesis by the growing culture of synechococcus was incorporated in the cell via the reductive pentose phosphate cycle. up to 70% of the label was incorporated into phosphoglyceric acid and phosphoric esters of sugars at all stages of the active cultural growth after 1 min of exposition in the light in the presence of nah14co3. the relative proportion of the label in phosphorylated compounds of the reductive pentose phosphate cycle decreased if the exposit ... | 1981 | 6163951 |
| antigenic similarity among anabaena azollae separated from different species of azolla. | 1982 | 6186252 | |
| 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 |
| siderophore-mediated iron uptake in different strains of anabaena sp. | anabaena sp. strain 6411, which produces the dihydroxamate siderophore schizokinen to facilitate iron uptake, is also capable of using the related siderophore aerobactin. the two siderophores compete for the same iron transport system, but there is a markedly higher affinity for ferric schizokinen than for ferric aerobactin. the trihydroxamate siderophore ferrioxamine b is far less effective as an iron donor in this organism. anabaena sp. strain 7120 appears to be closely related to strain 6411. ... | 1983 | 6227608 |
| d-erythrose supports nitrogenase activity in isolated anabaena sp. strain 7120 heterocysts. | among organic compounds tested for their ability to support nitrogenase activity in isolated heterocysts of anabaena sp. strain 7120 under argon, d-erythrose (5 mm) was unique in supporting acetylene reduction at 10 times the control rates. higher concentrations of d-erythrose exhibited substrate inhibition. at 50 kpa of h2, all concentrations of d-erythrose inhibited h2-supported acetylene reduction. the effects of d-erythrose on nitrogenase activity were explored. erythrose enhanced 15n2 incor ... | 1984 | 6229527 |
| effects of d-erythrose on nitrogenase activity in whole filaments of anabaena sp. strain 7120. | d-erythrose, which has been shown to enhance nitrogenase activity (acetylene reduction) by isolated heterocysts, was studied for its effects on nitrogenase activity and nitrite uptake by whole filaments of anabaena sp. strain 7120. d-erythrose had little effect on acetylene reduction in the light; however, at a concentration of 10 mm, it could restore 3'-(3,4-dichlorophenyl)-1',1'-dimethyl urea-inhibited or dark-limited levels to light-supported levels. sucrose, glucose, or fructose did not exhi ... | 1984 | 6238947 |
| the isolation and characterization of a sequence-specific endonuclease from anabaena subcylindrica. | an endonuclease, asui, was isolated from extracts of anabaena subcylindrica on the basis of gel-electrophoretic analysis of digests of bacteriophage-lambda dna with the paritally purified extracts. the enzyme requires mg2+, but no other cofactors. endonuclease asui recognizes the interrupted tetranucleotide sequence: (formula: see tex), and breaks the phosphodiester bonds indicated by the arrows to leave single-stranded trinucleotide projections at the 5'-termini of the dna fragments. | 1980 | 6246880 |
| the nucleotide sequences recognized by endonucleases avai and avaii from anabaena variabilis. | determination of the 5'-terminal sequences flanking all the individual cleavage sites for endonuclease avai in bacteriophage-lambda dna has shown that this enzyme recognizes the hexanucleotide sequences: (formula: see text), this sequence is cut as shown by the arrows to give single-stranded 5'-tetranucleotide protrusions (cohesive ends). endonucleases smai, xhoi and xmai recognize different symmetrical subsets of this sequence and provide independent evidence for the occurrence of these subsets ... | 1980 | 6246881 |
| new anabaena and nostoc cyanophages from sewage settling ponds. | 1981 | 6269286 | |
| isolation and physical mapping of nitrogen fixation genes from the cyanobacterium anabaena 7120. | 1982 | 6290496 | |
| cytochrome b/c complexes with polyprenyl quinol:cytochrome c oxidoreductase activity from anabaena variabilis and rhodopseudomonas sphaeroides ga: comparison of preparations from chloroplasts and mitochondria. | 1982 | 6292024 | |
| the structural nif genes of the cyanobacteria gloeothece sp. and calothrix sp. share homology with those of anabaena sp., but the gloeothece genes have a different arrangement. | probes carrying the anabaena sp. strain pcc 7120 nitrogenase reductase (nifh) and nitrogenase (nifk and nifd) genes were hybridized to southern blots of dna from the unicellular, aerobic nitrogen-fixing cyanobacterium gloeothece sp. strain pcc 6909 and from the filamentous cyanobacterium calothrix sp. strain pcc 7601. these data suggest that the gloeothece sp. nif structural proteins must be similar to those of other diazotrophs and that the ability for aerobic nitrogen fixation does not reside ... | 1983 | 6305921 |
| flash spectroscopic characterization of photosynthetic electron transport in isolated heterocysts. | electron transport was studied in heterocysts of the filamentous cyanobacterium anabaena 7120 using spectral and kinetic analysis of absorbance transients elicited by single turnover flashes. consistent photosynthetic turnovers were observed only in the presence of an exogenous source of reductant; therefore measurements were routinely made under a gas phase containing h2. prominent absorbance changes corresponding to the oxidation of cytochrome c (554 nm) and the reduction of cytochrome b563 (5 ... | 1983 | 6307149 |
| genetic and physical map of the structural genes (nifh,d,k) coding for the nitrogenase complex of rhodopseudomonas capsulata. | functional genes coding for the structural components of the nitrogenase complex (nifh,d,k) have been cloned on an 11.8-kilobase-pair hindiii fragment of dna from the photosynthetic bacterium rhodopseudomonas capsulata. the genes were physically mapped by hybridization of individual cloned nif genes from klebsiella pneumoniae and anabaena sp. strain 7120 to southern blots of hindiii digests of the cloned r. capsulata fragment, after introduction of hindiii sites into the latter at specified loca ... | 1983 | 6311797 |
| construction of shuttle vectors capable of conjugative transfer from escherichia coli to nitrogen-fixing filamentous cyanobacteria. | wild-type cyanobacteria of the genus anabaena are capable of oxygenic photosynthesis, differentiation of cells called heterocysts at semiregular intervals along the cyanobacterial filaments, and aerobic nitrogen fixation by the heterocysts. to foster analysis of the physiological processes characteristic of these cyanobacteria, we have constructed a family of shuttle vectors capable of replication and selection in escherichia coli and, in unaltered form, in several strains of anabaena. highly ef ... | 1984 | 6324204 |
| oxygen-dependent proton efflux in cyanobacteria (blue-green algae). | the oxygen-dependent proton efflux (in the dark) of intact cells of anabaena variabilis and four other cyanobacteria (blue-green algae) was investigated. in contrast to bacteria and isolated mitochondria, an h+/e ratio (= protons translocated per electron transported) of only 0.23 to 0.35 and a p/e ratio of 0.8 to 1.5 were observed, indicative of respiratory electron transport being localized essentially on the thylakoids, not on the cytoplasmic membrane. oxygen-induced acidification of the medi ... | 1984 | 6327614 |
| protein hu in the enzymatic replication of the chromosomal origin of escherichia coli. | a protein that stimulates the enzymatic replication of duplex dnas of recombinant phages and plasmids bearing the escherichia coli origin of replication (oric) has been isolated from an extract of e. coli. the isolated protein and the well-known protein hu, a histone-like dna-binding protein, have identical polypeptide molecular weights and saturate the oric replication assay at less than 40 dimers per template dna circle. this level is one-tenth that needed to coat the template. protein hu from ... | 1984 | 6364143 |
| oxygen inactivation and recovery of nitrogenase activity in cyanobacteria. | exposure of nitrogen-fixing cultures of anabaena spp. to 100% oxygen resulted in the rapid decline of nitrogenase activity. when oxygen-treated cells were transferred to 100% argon, nitrogenase activity was quickly restored in a process that required protein synthesis. anaerobiosis was not essential for the recovery process; in fact, cells of anabaena sp. strains ca and 1f will recover nitrogenase activity after prolonged incubation in 100% oxygen. oxygen treatment acted directly on the intracel ... | 1983 | 6401277 |
| 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 |
| effect of retorted-oil shale leachate on a blue-green alga (anabaena flos-aquae). | 1983 | 6403088 | |
| apparent blue-green algae poisoning in swine subsequent to ingestion of a bloom dominated by anabaena spiroides. | 1983 | 6403497 | |
| adenine nucleotide levels in and nitrogen fixation by the cyanobacterium anabaena sp. strain 7120. | adenine nucleotide levels were determined in whole filaments of anabaena sp. 7120 grown under different n2-fixing or non-n2-fixing conditions. these were compared with levels in isolated heterocysts, rhodospirillum rubrum, and azotobacter vinelandii. adenine nucleotides in whole filaments of anabaena sp. do not reflect the energetic expense of n2 fixation as they do in r. rubrum and a. vinelandii. however, adenine nucleotide levels in heterocysts were similar to the levels found in n2-fixing r. ... | 1983 | 6403506 |
| regulation of hydrogenase activity in vegetative cells of anabaena variabilis. | heterocyst-free (nh4+-grown) cultures of the cyanobacterium anabaena variabilis produce a hydrogenase which is reversibly inhibited by light and o2. white or red light at an intensity of 5,000 lx inhibited greater than 95% of the activity. oxygen at concentrations as low as 0.5% inhibited more than 85% of the hydrogenase in the vegetative cells of co2-nh4+-grown cultures. the vegatative cell hydrogenase is also sensitive to strong oxidants like ferricyanide. in the presence of strong reductants ... | 1983 | 6408057 |
| effects of sodium azide on phototaxis of the blue-green alga anabaena variabilis and consequences to the two-photoreceptor systems-hypothesis. | experiments with sodium azide support the earlier report that two different photoreceptor systems participate in the absorption of the phototactically active light in anabaena variabilis. the one of them, represented by the phycobiliproteins and chlorophyll a, is responsible for positive and negative phototaxis around 440 nm and between 580 and 700 nm. this system is sensitive to sodium azide which is able to reverse the negative reaction at high fluence rates to a positive one. the second one w ... | 1983 | 6409048 |
| 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 |
| molecular weight of gas-vesicle protein from the planktonic cyanobacterium anabaena flos-aquae and implications for structure of the vesicle. | the gas vesicle of the planktonic cyanobacterium anabaena flos-aquae is a cylindrical shell made of protein enclosing a gas-filled space. protein sequence analysis shows that the vesicle is made from a single protein. by gel electrophoresis and amino acid analysis its molecular weight was estimated to be 20 600. taken with previously obtained x-ray data, a simple interpretation of its molecular structure is of the polypeptide snaking in six pairs of antiparallel chains, three in each layer. the ... | 1983 | 6409075 |
| high endogenous nitrogenase activity in isolated heterocysts of anabaena sp. strain ca after nitrogen starvation. | metabolically active heterocysts were isolated from a mutant of anabaena sp. strain ca with fragile vegetative cells. heterocysts isolated from cultures grown in 1% co2 in air reduced c2h2 at 57 and 10 nmol of c2h2 per mg (dry weight) per min under h2 and ar, respectively. however, if whole filaments were sparged with 1% co2 in 99% ar for 12 h before heterocyst isolation, these heterocysts showed c2h2 reduction rates of 83 nmol of c2h4 per mg (dry weight) per min under either h2 or ar, or 40% th ... | 1983 | 6409878 |
| permeabilization of isolated heterocysts of anabaena sp. strain 7120 with detergent. | heterocysts isolated from anabaena sp. strain 7120 with lysozyme plus sonication were permeabilized with the cationic detergent cetyltrimethylammonium bromide, and they then exhibited comparable acetylene reduction activity in the light and dark with an atp-regenerating system plus dithionite. the detergent diminished the effect of h2 in enhancing acetylene reduction. | 1983 | 6409890 |
| the effects of acetaldehyde on nitrogenase, hydrogenase and photosynthesis in the cyanobacterium anabaena cylindrica. | acetaldehyde was shown to be an irreversible inhibitor of nitrogenase, hydrogenase, co2 fixation and growth in the cyanobacterium anabaena cylindrica, but had no effect on photosynthetic electron flow as measured by methyl viologen-dependent o2 uptake. the concentration-dependence of the inhibition of nitrogenase and hydrogenase activities was determined, and it was shown that acetaldehyde inhibition poses problems for anaerobic experiments in which the activities of these enzymes are measured i ... | 1983 | 6411074 |
| cyanophages. | the description of cyanophages isolated in the ussr is given. the data presented here primarily concern cyanophages of a(l) and s(l) series developing in the cells of anabaena variabilis strains of synechococcus species strains, respectively. | 1983 | 6416127 |
| some aspects of the ecophysiology of cyanobacteria. | fresh waters rich in nutrients often show mass development of cyanobacteria. the kind of cyanobacteria to be found depends on the properties of the lake. in non-stratified shallow lakes, the most common species oscillatoria agardhii. in stratified lakes, cyanobacteria can be found in restricted zones of the deeper part of the lakes, and always possess cells with very active gas vacuoles. the most common species are microcystis aeruginosa, oscillatoria agardhii var isothrix, oscillatoria "var red ... | 1983 | 6416128 |
| aerobic hydrogen production by the heterocystous cyanobacteria anabaena spp. strains ca and 1f. | aerobic photoproduction of h2 was demonstrated in anabaena spp. strains ca and 1f when cells were growing under nitrogen-fixing conditions. the rates of production, measured either by the hydrogen electrode or in a flow system by gas chromatography, were 10 to 15% of the rate of photosynthetic o2 evolution or 50 to 80% of the rates of acetylene reduction. strains ca and 1f differed in several respects. in strain ca, h2 production was immediately partially sensitive to 3-(3,4-dichlorophenyl)-1,1- ... | 1983 | 6417109 |
| thioredoxins and the redox modulation of glucose-6-phosphate dehydrogenase in anabaena sp. strain pcc 7120 vegetative cells and heterocysts. | glucose-6-phosphate dehydrogenase (g6pdh) was isolated from heterocysts and vegetative cells of anabaena sp. strain pcc 7120. both enzyme preparations proved to be more active in their oxidized than in their reduced forms. at least one protein with thioredoxin activity was found in anabaena sp. which, if reduced with dithiothreitol, deactivated the g6pdh preparations. the deactivated heterocyst g6pdh could be reactivated neither by o2 nor by oxidized thioredoxin. reactivation of the enzyme was, ... | 1984 | 6420395 |
| effect of acetic acid on phycocyanin-phycoerythrocyanin mixture extracted from anabaena variabilis. | exposure of a phycocyanin-phycoerythrocyanin mixture extracted from anabaena variabilis to sodium acetate, ph 3.8, ionic strength of 0.1, results in dissociation of the phycoerythrocyanin's beta subunit from its alpha subunit. the alpha subunit obtained by this method has a strong absorption transition at 508 nm. this transition is a consequence of the subunit's specific conformation, rather than of a new chromophore. the behavior of the phycocyanin-phycoerythrocyanin mixture in acetate buffers ... | 1984 | 6421237 |
| purification and properties of glutathione reductase from the cyanobacterium anabaena sp. strain 7119. | an nadph-glutathione reductase (ec 1.6.4.2) has been purified 6,000-fold to electrophoretic homogeneity from the filamentous cyanobacterium anabaena sp. strain 7119. the purified enzyme exhibits a specific activity of 249 u/mg and is characterized by being a dimeric flavin adenine dinucleotide-containing protein with a ratio of absorbance at 280 nm to absorbance at 462 nm of 5.8, a native molecular weight of 104,000, a stokes radius of 4.13 nm, and a pi of 4.02. the enzyme activity is inhibited ... | 1984 | 6425264 |
| x-ray diffraction studies on photosystem i fragments from a blue-green alga, anabaena variabilis, and spinach. | photosystem i fragments were prepared from thylakoid membranes of a blue-green alga (anabaena variabilis) and spinach by treatment with a detergent, triton x-100. equatorial x-ray diffraction patterns were recorded on films for oriented specimens of thylakoid membranes and photosystem i fragments. the thylakoid membranes and photosystem i fragments gave essentially the same equatorial diffraction patterns in both anabaena variabilis and spinach, indicating that the major x-ray scatterers in thes ... | 1984 | 6425276 |