| nitrogen and ammonia assimilation in the cyanobacteria: purification of glutamine synthetase from anabaena sp. strain ca. | glutamine synthetase was purified from the cyanobacterium anabaena sp. strain ca, a newly isolated marine organism. this organism grows rapidly under nitrogen-fixing conditions and therefore is ideally suited for studies concerning cyanobacterial nitrogen metabolism. studies were conducted to optimize the production of glutamine synthetase by anabaena ca. the highest specific activities were obtained from cells grown in the presence of atmospheric n(2) or kno(3) (13 mm); when nh(4)cl was used as ... | 1977 | 21167 |
| [selective effects of lindane (gamma-1,2,3,4,5,6 hexachlorocyclohexane) on photosynthesis, membrane transport of amino acids and protein synthesis in anacystis nidulans (author's transl)]. | effects of the chlorinated hydrocarbon insecticide lindane on membrane transport of two neutrale amino acids in the cyanobacterium anacystis nidulans (synechococcus an) were measured. in white light the l-leucine incorporation into the protein fraction was inhibited, increasing with time. after 30 minutes the degree of inhibition was the same as the effect of dcmu (5 x 10(-6) m) on l-leucine incorporation. 14co2-fixation was also reduced at this time. at 717 nm, which enables ps i activity allon ... | 1979 | 94199 |
| molybdenum independence of nitrogenase component synthesis in the non-heterocystous cyanobacterium plectonema. | the cyanobacterium plectonema boryanum (iu 594-utex 594) fixes n2 only in the absence of combined n and of o2. we induced nitrogenase by transfer to anaerobic n-free medium and studied the effect of mo starvation on nitrogenase activity and synthesis. activity was first detected within 3 h after transfer by the acetylene reduction assay in controls, increasing for at least 25 h. cells grown on nitrate and mo and then transferred to n-free, mo-free medium produced 8% of the control nitrogenase ac ... | 1978 | 96092 |
| comparative studies on two ferredoxins from the cyanobacterium nostoc strain mac. | two ferredoxins were isolated from the cyanobacterium nostoc strain mac grown autotrophically in the light or heterotrophically in the dark. in either case approximately three times as much ferredoxin i as ferredoxin ii was obtained. both ferredoxins had absorption maxima at 276, 282 (shoulder), 330, 423 and 465 nm in the oxidized state, and each possessed a single 2 fe-2s active centre. their isoelectric points were approx. 3.2. the midpoint redox potentials of the ferredoxins differed markedly ... | 1978 | 99139 |
| energy transduction in the photosynthetic membranes of the cyanobacterium (blue-green alga) p-lectonema boryanum. | membrane preparations isolated from the photosynthetic lamellae of the cyanobacterium plectonema boryanum generate upon illumination a transmembrane ph gradient of approximately 2 to 3 ph units (acid inside), as determined from the distribution of either fluorescent or radioactive amines (9 aminoacridine and 14cmethylamine, respectively). using the distribution of permeant ions to measure the electrical potential across the membrane, it was found that the latter is practically nil under conditi ... | 1978 | 25283 |
| cyanobacterial phycobilisomes. characterization of the phycobilisomes of synechococcus sp. 6301. | a procedure is described for the preparation of stable phycobilisomes from the unicellular cyanobacterium synechococcus sp. 6301 (also known as anacystis nidulans). excitation of the phycocyanin in these particles at 580 nm leads to maximum fluorescence emission, from allophycocyanin and allophycocyanin b, at 673 nm. electron microscopy shows that the phycobilisomes are clusters of rods. the rods are made up of stacks of discs which exhibit the dimensions of short stacks made up primarily of phy ... | 1978 | 101538 |
| effect of levulinic acid on pigment biosynthesis in agmenellum quadruplicatum. | when levulinic acid was added to a growing culture of the cyanobacterium (blue-green alga) agmenellum quadruplicatum pr-6, delta-aminoelevulinic acid accumulated in the medium and chlorophyll a synthesis and cell growth were inhibited, but there was a small amount of c-phycocyanin synthesis. the amount of delta-aminolevulinic acid produced in the treated culture did not fully account for the amount of pigment synthesized in the untreated control. levulinic acid and either sodium nitrate or ammon ... | 1979 | 104956 |
| isolation and characterization of the hydrogenase activity from the non-heterocystous cyanobacterium spirulina maxima. | | 1979 | 105936 |
| computer method for predicting the secondary structure of single-stranded rna. | we present a computer method utilizing published values for base pairing energies to compute the most energetically favorable secondary structure of an rna from its primary nucleotide sequence. after listing all possible double-helical regions, every pair of mutally incompatible regions (whose nucleotides overlap) is examined to determine whether parts of those two regions can be combined by branch migration to form a pair of compatible new subregions which together are more stable than either o ... | 1978 | 100768 |
| a glucan from the cell wall of the cyanobacterium spirulina platensis. | a polysaccharide was isolated from the cell wall of the cyanobacterium spirulina platensis. hydrolysis of the polysaccharide only yielded glucose. curie-point pyrolysis mass spectrometry of the polysaccharide resulted in a spectrum very similar to that of beta-1,2-glucan. probably the glucan originates from the fibrillar inner layer of the cell wall. | 1978 | 110253 |
| [effect of lysozyme, ethylenediaminetetraacetate, magnesium and mannittol on spheroplast formation in anacystis nidulans]. | three periods (the lag period and periods of intensive and decelerated spheroplast formation) can be detected in the action of lysozyme on the cells of anacystis nidulans; this seems to be due to peculiarities in the cell wall structure of the cyanobacterium and heterogeneity of the culture. edta at concentrations of 0.175--0.7 mm has effect on the duration of the lag period but increases the rate of spheroplast formation during the subsequent periods. however, the action of edta in complex with ... | 1979 | 113653 |
| effects of 5-hydroxylysine on acetylene reduction and nh4+-assimilation in the cyanobacterium anabaena cylindrica. | | 1978 | 100112 |
| composition and biological properties of lipopolysaccharides isolated from schizothrix calcicola (ag.) gomont (cyanobacteria). | the most common cyanobacterium contaminating drinking water systems in southwestern pennsylvania is schizothrix calcicola. lipoplysaccharides (lps) were isolated from this species by hot phenol-water extraction. the polysaccharide moiety was composed of glucosamine, galactose, glucose, mannose, xylose and rhamnose. the lipid a part contained beta-hydroxylauric, myristic, pentadecanoic, palmitic, beta-hydroxypalmitic, stearic, oleic, and linoleic acids. in contrast to many lps isolated from enter ... | 1979 | 119486 |
| effect of tryptophan analogues on lipid metabolism in the cyanobacterium anabaena cylindrica [proceedings]. | | 1979 | 119656 |
| the site of inhibition of photosystem ii by 3-(3,4-dichlorophenyl)-n-n'-dimethylurea in thylakoids of the cyanobacterium anabaena cylindrica. | | 1978 | 100110 |
| changes in thylakoid structure associated with the differentiation of heterocysts in the cyanobacterium, anabaena cylindrica. | the thylakoids of vegetative cells of the filamentous cyanobacterium, anabaena cylindrica, are capable of oxygen-evolving photosynthesis and contain both photosystems i and ii (psi and psii). the heterocysts, cells specialized for nitrogen fixation, do not produce oxygen and lack photosystem ii activity, the major accessory pigments, and perhaps the chlorophyll a associated with psii. freeze-fracture replicas of vegetative cells and of heterocysts reveal differences in the structure of the thyla ... | 1979 | 110342 |
| measurement in vivo of hydrogenase-catalysed hydrogen evolution in the presence of nitrogenase enzyme in cyanobacteria. | a method was devised that allows measurement in vivo of hydrogenase-catalysed h2 evolution from the cyanobacterium anabaena cylindrica, independent of nitrogenase activity, which is also present. addition of low concentrations of reduced methyl viologen (1-10mm) to intact heterocystous filaments of the organism resulted in h2 evolution, but produced conditions giving total inhibition of nitrogenase (acetylene-reducing and h2-evolving) activity. that the h2 formed under these conditions was not c ... | 1979 | 106842 |
| effect of light on the attachment of cyanophage as-1 to anacystis nidulans. | the effect of illumination on the extent and kinetics of the adsorption of cyanophage as-1 to the blue-green alga (cyanobacterium) anacystis nidulans was studied by using 32p-labeled phage. the initial rate of adsorption was not significantly affected by light. however, at na+ levels used ordinarily to culture the alga ([na+] = 11.7 mm), the total amount of phage adsorbed was doubled in the illuminated cultures, as compared with the dark-grown ones, over a wide range of multiplicities of infecti ... | 1979 | 104977 |
| the complete amino acid sequence of both subunits of c-phycocyanin from the cyanobacterium mastigocladus laminosus. | the amino acid sequences of both subunits of the c-phycocyanin from the thermophilic cyanobacterium mastigocladus laminosus have been determined. the alpha-chain consists of 162 amino acid residues and has a molecular weight of 18000, whereas the beta-chain consists of 172 residues and has a molecular weight of 19400. for the first three quarters of their length the polypeptide chains are 31% homologous, whereas there is no significant homology in the final quarter up to the c-terminus. this cou ... | 1978 | 103794 |
| sporulation in the filamentous cyanobacterium anabaena cylindrica. the course of spore formation. | sporulation in the filamentous cyanobacterium anabaena cylindrica involves the transformation of a vegetative cell into a thick-walled resistant structure. because this process occurs at predictable loci in each filament and involves a significant increase in cell size, the course of sporulation in a culture can be quantitatively determined. sporulation occurs during the late logarithmic phase of a culture, a time of slow but unbalanced growth. under the conditions employed here, sporulation is ... | 1977 | 402126 |
| ultraviolet light-induction and photoreactivation of thymine dimers in a cyanobacterium, anacystis nidulans. | partially photoreactivable mutant of anacystis nidulans demonstrates partial photorepair of thymine dimers. the wild type which is completely photoreactivable at the conditions studied shows higher level of thymine dimer photolysis. | 1978 | 100072 |
| arginine catabolism in aphanocapsa 6308. | the catabolic products of arginine metabolism were observed in aphanocapsa 6308, a unicellular cyanobacterium, by thin layer chromatography of growth media, by limiting growth conditions, and by enzymatic analysis. of the organic, nitrogenous compounds examined, only arginine supported growth in co2-free media. the excretion of ornithine at a concentration level greater than citrulline suggested the existence in aphanocapsa 6308 of the arginine dihydrolase pathway which produced ornithine, co2,n ... | 1978 | 100070 |
| dark hexose metabolism by photoautotrophically and heterotrophically grown cells of the blue-green alga (cyanobacterium) nostoc sp. strain mac. | photoautotrophically grown cells of the blue-green alga (cyanobacterium) nostoc sp. strain mac assimilated and oxidized both glucose and fructose in the dark at different rates. the rate of fructose metabolism in these cells could be stimulated by casein hydrolysate, the effect being most pronounced at low sugar concentrations. this stimulation was not seen in cells grown heterotrophically in the dark, suggesting that it is a transitory phenomenon which disappears during the autotrophy-heterotro ... | 1978 | 99438 |
| a zoogloea sp. associated with blooms of anabaena flos-aquae. | bacteria were found attached to the heterocysts of aphanizomenon flos-aquae and embedded within the mucilage of both anabaena flos-aquae and microcystis aeruginosa in freshwater plankton. electron microscopy of thin sections preceding the peak of an anabaena flos-aquae bloom showed that the density of bacterial cells was 7.4 x 10(5) cells/ml in the planktonic macroenvironment and 2.6 x 10(11) cells/ml within the microenvironment of cyanobacterial mucilage. the bacteria occurred in aggregates and ... | 1978 | 99218 |
| polyamines of anacystis nidulans and metabolism of exogenous spermidine and spermine. | several biochemical parameters, including that of polyamine content, accompanying the growth of the cyanobacterium anacystis nidulans were studied. at all stages of growth under autotrophic conditions, the organisms were found to be rich in spermidine and lacking in spermine, as is typical of procaryotic organisms. the cells were quite low in putrescine, and no unusual polyamine was observed to be present as a major component. conjugated polyamines were not detected in the cultures. at maximal c ... | 1978 | 96100 |
| studies on the flavodoxins from a cyanobacterium and a red alga [proceedings]. | | 1977 | 411701 |
| a unique crystalline wall layer in the cyanobacterium microcystis marginata. | | 1978 | 77331 |
| modifiers of heterocyst repression and spacing and formation of heterocysts without nitrogenase in the cyanobacterium anabaena variabilis. | twelve amino acid analogs and related compounds were screened for their ability to induce heterocysts in ammonia-repressed, undifferential filaments of anabaena variabilis. as has been previously described, 1-methionine-dl-sulfoximine induces both heterocysts and nitrogenase. in contrast, dl-7-azatryptophan and beta-2-thienyl-dl-alanine were found to induce heterocysts but not nitrogenase activity (measured as acetylene reduction) even under microaerobic conditions. when the initial ammonium con ... | 1979 | 40953 |
| transport of d-glucose and 3-o-methyl-d-glucose in the cyanobacteria aphanocapsa 6714 and nostoc strain mac. | 1. the cyanobacterium aphanocapsa 6714 which grow in the dark on d-glucose, will take up d-glucose and the analogue 3-o-methyl-d-glucose; uptake of each of these compounds was inhibited competitively by the other and by 6-deoxy-d-glucose. 2. this cyanobacterium accumulated 3-o-methyl-d-glucose up to 100-fold relative to the medium but did not modify or metabolize it to a significant degree. 3. intracellular 3-o-methyl-d-glucose was rapidly displaced from aphanocapsa 6714 by exogenous d-glucose a ... | 1978 | 413715 |
| induction of anaerobic, photoautotrophic growth in the cyanobacterium oscillatoria limnetica. | anaerobic photoautotrophic growth of the cyanobacterium oscillatoria limnetica was demonstrated under nitrogen in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (5micron), a constant concentration of na2s (2.5 mm), and constant ph (7.3). the photoanaerobic growth rate (2 days doubling time) was similar to that obtained under oxygenic photoautotrophic growth conditions. the potential of oxygenic photosynthesis is constitutive in the cells; that of anoxygenic photosynthesis is rapidly (2 ... | 1978 | 415043 |
| mechanism of toxicity of putrescine in anacystis nidulans. | putrescine is lethal to the cyanobacterium anacystis nidulans at extracellular ph values at which significant concentrations of the nonprotonated diamine rapidly diffuse into the cell and accumulate as the charged form. although over 98% of the accumulated putrescine is not metabolized, a small fraction is rendered trichloroacetic acid-insoluble, and about 90% of this is bound as putrescinie to proteins and cell structures. various synthetic functions were studied in the presence of a bacteriost ... | 1979 | 40229 |
| distinctive properties of glutamine synthetase from the cyanobacterium anacystis nidulans. | the intracellular levels of glutamine synthetase (gs) in anacystis nidulans grown under different conditions were determined using a whole-cell assay. nitrate-grown cells have 64% more gs than cells grown in ammonium sulfate. nitrogen starvation does not affect gs levels appreciably. incubation of nitrate-grown cells with ammonium sulfate does not change the ratio of gamma-glutamyl transferase activities stimulated by mg2+ and mn2+ ions. an in vitro test of adenylylation indicates that algae do ... | 1979 | 38892 |
| virus infection affects the molecular properties and activity of glucose-6-p dehydrogenase in anacystis nidulans, a cyanobacterium. novel aspect of metabolic control in a phage-infected cell. | | 1979 | 114419 |
| purification and properties of nitrogenase from the cyanobacterium, anabaena cylindrica. | the nitrogenase complex was isolated from nitrogen-starved cultures of anabaema cylindrica. sodium dithionite, photochemically reduced ferredoxin, and nadph were found to be effective election donors to nitro genase in crude extracts whereas hydrogen and pyruvate were not. the km for acetylene in vivo is ten-fold higher than the km in vitro, whereas this pattern does not hold for the non-heterocystous cyanobacterium, plectonema boryanum. this indicates that at least one mechanism of oxygen prote ... | 1979 | 111934 |
| metabolic aspects of lpp cyanophage replication in the cyanobacterium plectonema boryanum. | cyanophage lpp1g is reproduced at the same yield in heterotrophic conditions (dark, glucose) as in photoautotrophic conditions; aerobiosis is required for dark cyanophage replication. exogenous glucose is not required for the cyanophage replication in the dark in heterotrophically grown cells. in photoautotrophically grown cells, the maximum burst size in dark and glucose is delayed for a period corresponding to glucose uptake induction. cyanophage lpp2spi replication occurs in conditions where ... | 1976 | 816372 |
| hydrogen evolution from immobilized cultures of the cyanobacterium anabaena cylindrica b629. | | 1979 | 109313 |
| characteristics of a new cyanophage lysing unicellular cyanobacteria of the genus synechococcus. | a new cyanophage s-2l growing on three strains of the cyanobacterium belonging to the synechococcus genus has been isolated. the cyanophage has an icosahedral head, 56 nm in diameter, and flexible tail with a non-contracting sheath, 120 nm long. over 95 per cent of the cyanophage particles are adsorbed within 10 min, the rate constant of adsorption being 3.2-10(-9) ml/min. the latent period lasts 5 hours, the yield is 100 particles per cell. the intracellular growth is characterized by the accum ... | 1977 | 19685 |
| the biosynthesis of multi-l-arginyl-poly(l-aspartic acid) in the filamentous cyanobacterium anabaena cylindrica. | the cyanobacteria produce multi-l-arginyl-poly (aspartic acid), a high molecular weight (mr=25 000-125 000) branched polypeptide consisting of a poly(aspartic acid) core with l-arginyl residues peptide bonded to each free carboxyl group of the poly(aspartic acid). an enzyme which will elongate arg-poly(asp) has been isolated and purified 92-fold from the filamentous cyanobacterium anabaena cylindrica. the enzyme incorporates arginine and aspartic acid into arg-poly(asp) in a reaction which requi ... | 1976 | 2311 |
| regulation of uridylic acid biosynthesis in the cyanobacterium anabaena variabilis. | the pathway of uridylic acid biosynthesis established by leiberman, kornberg, and simms has been shown to be operative in the filamentous cyanobacterium anabaena variabilis. the only enzyme of uridylic acid biosynthesis found to be lacking in two uracil-requiring strains of a. variabilis was aspartate transcarbamylase, the first enzyme in the pathway of de novo biosynthesis of uridvlic acid. neither uracil-limited growth of a uracil-requiring mutant nor growth of the wild type in high concentrat ... | 1978 | 30757 |
| isolation and characterization of a membrane-bound, low-potential c-type cytochrome from purple photosynthetic bacteria, with special reference to rhodospirillum rubrum. | other investigators have isolated soluble, low-potential, c-type cytochromes (cytochrome c3) from a few photosynthetic procaryotes, i.e., a cyanobacterium and two species of purple nonsulfur bacteria. however, such cytochromes appeared to be absent from other purple bacteria, including rhodospirillum rubrum and chromatium vinosum. we now report evidence for the presence of low-potential c-type cytochromes in these two species, in which they were found to be bound to the photosynthetic membranes. ... | 1978 | 214418 |
| purification and primary structure of cytochrome f from the cyanobacterium, plectonema boryanum. | the amino acid sequence of the soluble c-type cytochrome, cytochrome f, from the cyanobacterium plectonema boryanum (also called phormidium luridum or schizothrix calcicola) has been determined. the proposed sequence consists of one polypeptide chain of 85 residues and has three asn-gly linkages. partly due to the presence of these asn-gly bonds, which readily undergo rearrangement, proteolytic digestion on the small amount of protein available was unsatisfactory. the structure was determined pa ... | 1977 | 199428 |
| uptake of iron by gomphosphaeria aponina, a possible control organism for the florida red tide pytochodiscus brevis. | the assimilation of iron, a growth-limiting metal ion of the cytotoxic marine cyanobacterium, gomphosphaeria aponina, has been examined in both static and steady-state cultures using 59fe (iii). uptake of iron by cells followed first-order kinetics, and biphasic (absorption and uptake) behavior was observed as suggested by noted differences between cultures incubated in the light and in the dark. iron removal in illuminated cultures was rapid, occurring at rates comparable to exponential growth ... | 1979 | 162148 |
| regulation of phosphate accumulation in the unicellular cyanobacterium synechococcus. | the phosphorus contents of acid-soluble pools, lipid, ribonucleic acid, and acid-insoluble polyphosphate were lowered in synechococcus in proportion to the reduction in growth rate in phosphate-limited but not in nitrate-limited continuous culture. phosphorus in these cell fractions was lost proportionately during progressive phosphate starvation of batch cultures. acid-insoluble polyphosphate was always present in all cultural conditions to about 10% of total cell phosphorus and did not turn ov ... | 1979 | 227842 |
| [interferometric studies of the dynamics of hydration and dry matter content during light-dependent germination of the anabaena variabilis kützing akinetes]. | calculations following interference-microscopical measurements performed on akinetes (a), heterocyts (h), and "vegetative" cells (f) of the cyanobacterium (blue-green alga) anabaena variabilis resulted in significant higher values of mean absolute dry matter content of the akinetes (2.06 . 10(-10) g; as compared to 0.46 . 10(-10) g and 0.31 . 10(-10) g for h and f, respectively). tthe water content of these resting cells (63%) was significantly lower than in the other two types of cells (h: 85%, ... | 1979 | 120999 |
| [hydrogen production by the cyanobacterium anabaena variablis in the light]. | light of low intensity (less than or equal to 25-10(5) erg-cm(-2)-sec(-1)) stimulates hydrogen production by cell suspensions of anabaena variabilis in the presence of glucose, pyruvate or formate. the maximum rate of hydrogen production in the presence of these substrates was observed at light intensities of 650, 1400 and 2250 erg-cm(-2)-sec(-1), respectively. the rate of oxygen production by the cells increases while the rate of hydrogen evolution decreases with increase in light intensity (2. ... | 1976 | 827669 |
| [cloning and expression of the clostridium thermocellum gene in cyanobacteria anacystis nidulans r2 cells]. | the xhoi-salgi fragment of the plasmid pci dna was inserted into the salgi site of the cyanobacterium anacystis nidulans r2 integrative vector plasmid piah4. the fragment incorporates the endoglucanase gene of clostridium thermocellum cloned earlier within the 6.7 kb dna sequence. the recombinant plasmid dna was transformed into anacystis nidulans r2 cells. the cloned endoglucanase gene was shown to express in the cyanobacterium cells. the enzyme synthesized is accumulated within the cytoplasm o ... | 1992 | 1301503 |
| the dark respiration of anacystis nidulans. production of hcn from histidine and oxidation of basic amino acids. | the basic amino acids, l-arginine, l-lysine, lo-irnithine, and to a lesser extent l-histidine, strongly stimulate the o2 uptake of cell suspensions of the blue-green alga or cyanobacterium anacystis nidulans. in the case of l-histidine, the extra o2 consumption is associated with the formation in vivo of small amounts of hcn, particularly in an atmosphere of o2. the enzyme responsible for both the stimulated o2 uptake with the basic amino acids and the formation of hcn from histidine has been is ... | 1979 | 223652 |
| effect of nitrogen starvation on the level of adenosine 3',5'-monophosphate in anabaena variabilis. | low levels of adenosine 3',5'-monophosphate (cyclic amp) were detected in the cyanobacterium anabaena variabilis using a protein binding assay and two radioisotopic labelling methods. the basal concentration of intracellular cyclic amp ranged from 0.27 pmol/mg protein in a. variabilis kutz grown under heterotrophic conditions to 1.0--2.7 pmol/mg protein in a. variabilis strain 377 grown autotrophically. extracellular cyclic amp was found to comprise as much as 90% of the total cyclic amp in rapi ... | 1979 | 228756 |
| isolation and characterization of a coupling factor i atpase of the thermophilic blue-green alga (cyanobacterium) mastigocladus laminosus. | | 1979 | 157885 |
| the ultrastructure of spirulina platensis in relation to temperature and light intensity. | the ultrastructure of spirulina platensis, a cyanobacterium with a helical morphology, has been studied in relation to temperature and light intensity. an increase in temperature gives rise to a more tightly coiled trichome, an increase in sheath material formation and a decrease in cyanophycin (above 17 degrees c) and polyglucan (above 20 degrees c) granule concentration. an increase in light intensity leads to an increase in gas vesicle concentration while the phycobilisome content decreases. ... | 1979 | 233414 |
| macromolecular composition of spores from the filamentous cyanobacterium a nabaena cylindrica. | spores were isolated from the filamentous cyanobacterium anabaena cylindrica, and their deoxyribonucleic acid, ribonucleic acid, and protein compositions were determined. | 1977 | 402350 |
| [morphologic heterogeneity under different conditions of living and destruction in anabaena variabilis cyanobacteria]. | the proportion between various morphological forms of the cyanobacterium anabaena variabilis was studied under different conditions of its growth and destruction. when the cells lost viability at the stationary phase of cultural growth under the optimal conditions of illumination (1500--2000 lx), in the dark or when nitrogen was deficient, the filaments became shorter (4 to 2.2 cells per filament on the average), the cells larger, 4.5x6 microns). under the conditions of nitrogen deficiency, the ... | 1979 | 116116 |
| transcriptional regulation of the plastocyanin and cytochrome c553 genes from the cyanobacterium anabaena species pcc 7937. | the effect of copper on the levels of plastocyanin (pc) and cytochrome c553 (cyt-c)-specific transcripts from anabaena sp. pcc 7937 was investigated. the addition of copper resulted in a marked increase in pc mrna levels, and a decrease in cyt c mrna levels. thus the functional exchange between pc and cyt c seems to be regulated at the mrna level. the copper-dependent increase in pc and decrease in cyt c mrna levels was abolished when chloramphenicol was added to the cells. this suggests that de ... | 1992 | 1320727 |
| amino and carboxy terminal sequences of the dna-binding protein hu from the cyanobacterium synechocystis pcc 6701 (atcc 27170). | | 1979 | 229851 |
| studies on ultrastructure and composition of cell walls of the cyanobacterium anacystis nidulans. | | 1977 | 410379 |
| the pathways of assimilation of 13nh4+ by the cyanobacterium, anabaena cylindrica. | the principal initial product of metabolism of 13n-labeled ammonium by anabaena cylindrica grown with either nh4+ or n2 as nitrogen source is amide-labeled glutamine. the specific activity of glutamine synthetase is approximately half as great in nh4+-grown as in n2-grown filaments. after 1.5 min of exposure to 13nh4+, the ratio of 13n in glutamate to 13n in glutamine reaches a value of approximately 0.1 for n2- and 0.15 for nh4+-grown filaments, whereas after the same period of exposure to [13n ... | 1977 | 410809 |
| purification and primary structure of cytochrome c-552 from the cyanobacterium, synechococcus pcc 6312. | cytochrome c-552 (soluble 'cytochrome f') from the unicellular cyanobacterium synechococcus pcc 6312 (atcc 27167) was purified and the primary structure determined. the proposed sequence consists of one polypeptide chain of 87 residues. the sequence was determined by a combination of chemical and enzymatic cleavage, manual and automatic sequencing and mass spectroscopy. this is the first amino acid sequence of this cytochrome from a unicellular cyanobacterium to be determined in a study of the v ... | 1979 | 228936 |
| isolation and preliminary characterization of auxotrophs of a filamentous cyanobacterium. | auxotrophic mutants of the filamentous cyanobacterium anabaena variabilis were isolated by a method in which, after mutagenesis and before penicllin enrichment, mutant and wild-type cells were separated by cavitation. auxotrophs were identified by their inability to grow on minimal medium, and they were partially characterized by replica plating to media supplemented with single nutrients or specific groups of nutrients. of the 83 auxotrophs isolated, 65 required an inorganic source of nitrogen ... | 1977 | 403180 |
| active transport of glucose and alpha-methylglucoside in the cyanobacterium plectonema boryanum. | | 1978 | 417083 |
| [age-related changes in the ultrastructure of anabaena variabilis cells]. | the growth and death of the obligate phototrophic cyanobacterium anabaena variabilis kütz, strain lefevre, were studied under stationary conditions in the light. each growth stage can be characterized by physiological and ultrastructural peculiarities. the following changes have been found in the cells with aging: the rate of oxygen evolution decreases, the photosynthetic lamellae untwist and separate with the formation of intrathylakoid vacuoles, the number of inclusions increases. irreversible ... | 1977 | 407428 |
| effect of temperature on the adsorption and one-step growth of the nostoc virus n-1. | this study was an attempt to observe the effects of temperature on adsorption and one-step growth of the virus n-1 infecting the nitrogen-fixing cyanobacterium nostoc muscorum. adsorption rate was found to maximum at 40 degrees c whereas no adsorption occurred at 10 degrees c. the q10 value was about 2.03 and the energy of activation, ea was 16.3 kcal/mole for the adsorption process. the development cycle of the virus was temperature sensitive. with increase in temperature, a gradual increase in ... | 1977 | 413522 |
| changes in photosynthetic activity in the cyanobacterium chlorogloea fritschii following transition from dark to light growth. | the cyanobacterium chlorogloea fritschii loses photosystem ii activity, measured by delayed fluorescence and oxygen evolution, during dark heterotrophic growth, but retains photosystem i, measured as light induced epr signals. following transition to the light, photosystem ii recovers in two stages, the first of which does not require protein synthesis. new photosystem i reaction centres are not synthesised until after net chlorophyll synthesis has commenced. carbon dioxide fixation recovery com ... | 1978 | 413576 |
| synthesis of nitrogenase in mutants of the cyanobacterium anabaena sp. strain pcc 7120 affected in heterocyst development or metabolism. | mutants of anabaena sp. strain pcc 7120 that are incapable of sustained growth with air as the sole source of nitrogen were generated by using tn5-derived transposons. nitrogenase was expressed only in mutants that showed obvious morphological signs of heterocyst differentiation. even under rigorously anaerobic conditions, nitrogenase was not synthesized in filaments that were unable to develop heterocysts. these results suggest that competence to synthesize nitrogenase requires a process that l ... | 1992 | 1328150 |
| identification of a phosphorus-containing storage granule in the cyanobacterium plectonema boryanum by electron microscope x-ray microanalysis. | transmission electron microscopy of cyanobacteria couple with x-ray microanalysis has confirmed that dense deposits within these cells are composed of phosphorous. | 1977 | 845121 |
| purification and determination of glutamine synthetase by high-performance immunoaffinity chromatography. | high-performance immunoaffinity chromatography (hpiac) with anti-glutamine synthetase polyclonal antibodies bound to epoxy-activated silica was used to purify and determine this enzyme from the cyanobacterium synechocystis. a single-step hpiac procedure with cell-free extracts yielded electroporetically homogeneous glutamine synthetase. in the determination of glutamine synthetase by hpiac a linear response in the range 10-60 micrograms of enzyme was observed. recoveries of 70% of the loaded enz ... | 1992 | 1347294 |
| characterization and structural properties of the major biliproteins of anabaena sp. | studies are presented of the biliproteins of anabaena sp. this filamentous cyanobacterium contains three major biliproteins. whereas two of these, c-phycocyanin and allophycocyanin, are common to all cyanobacteria, the third, phycoerythrocyanin (gammamax approximately 568 nm) has hitherto not been described and its distribution among cyanobacteria appears to be limited. anabaena variabilis and anabaena sp. 6411 allophycocyanin, c-phycocyanin, and phycoerythrocyanin were purified to homogeneity a ... | 1976 | 828020 |
| heterotrophic micro- and macrocultures of a nitrogen-fixing cyanobacterium. | anabaena variabilis can be cloned in the dark from fragments with one and few cells, with an efficiency of about 40%, on the nitrogen-free medium of allen and arnon solidified with 0.5% agarose and supplemented with 5 mm fructose. the organism can be grown exponentially (tau2 approximately or equal to 36 h) in fermentor cultures in the dark, fixing n2, to a density of greater than 10 g dry weight/l. | 1976 | 828022 |
| [connection of thylakoids with plasmalemma in the synechococcus cyanobacterium]. | the edges of the thylakoids are connected with the plasmalemma in the cyanobacterium synechococcus sp., strain 715, this leading to partial compartmentalization of the cytoplasm in the cell. | 1976 | 1004281 |
| [isolation, fractionation and comparative analysis of the cell membranes of the cyanobacterium, anabaena variabilis]. | a homogenate prepared from the protoplasts of anabaena variabilis was fractionated by differential centrifugation and zonal electrophoresis. four subcellular fractions were isolated and characterized with respect to their composition and morphology, two of them being of the membranous nature. membrane visicles from the light, chlorophyll-containing fraction were identified as small fragments of thylakoids while the pigment-deficient, heavy membrane fraction seemed to be represented by fragments ... | 1978 | 672686 |
| structure of the oxidized long-chain flavodoxin from anabaena 7120 at 2 a resolution. | the structure of the long-chain flavodoxin from the photosynthetic cyanobacterium anabaena 7120 has been determined at 2 a resolution by the molecular replacement method using the atomic coordinates of the long-chain flavodoxin from anacystis nidulans. the structure of a third long-chain flavodoxin from chondrus crispus has recently been reported. crystals of oxidized a. 7120 flavodoxin belong to the monoclinic space group p2(1) with a = 48.0, b = 32.0, c = 51.6 a, and beta = 92 degrees, and one ... | 1992 | 1303762 |
| toxic effects of omega chrome red me and its treatment by adsorption. | toxic effects of omega chrome red me, a popular textile dye, on the nitrogen fixing cyanobacterium nostoc calcicola were studied. the growth of n. calcicola was found to be suppressed at 10 and 20 mg liter-1 initial concentrations of dye, whereas a low initial concentration of 5 mg liter-1 slightly favors growth. removal of the dye was carried out by adsorption using some cheap and unconventional adsorbents like coal, fly ash, wollastonite, and china clay. it has been observed that, in all cases ... | 1992 | 1280581 |
| analysis of the gene encoding the rna subunit of ribonuclease p from cyanobacteria. | the genes encoding the rna subunit of ribonuclease p from the unicellular cyanobacterium synechocystis sp. pcc 6803, and from the heterocyst-forming strains anabaena sp. pcc 7120 and calothrix sp. pcc 7601 were cloned using the homologous gene from anacystis nidulans (synechococcus sp. pcc 6301) as a probe. the genes and the flanking regions were sequenced. the genes from anabaena and calothrix are flanked at their 3'-ends by short tandemly repeated repetitive (strr) sequences. in addition, two ... | 1992 | 1282240 |
| uncultivated cyanobacteria, chloroflexus-like inhabitants, and spirochete-like inhabitants of a hot spring microbial mat. | analysis of 16s rrna sequences retrieved as cdna (16s rcdna) from the octopus spring cyanobacterial mat has permitted phylogenetic characterization of some uncultivated community members, expanding our knowledge or diversity within this microbial community. two new cyanobacterial 16s rrna sequences were discovered, raising to four the number of cyanobacterial sequence types known to occur in the mat. none of the sequences found is that of the cultivated thermophilic cyanobacterium synechococcus ... | 1992 | 1282313 |
| stoichiometric association of extrinsic cytochrome c550 and 12 kda protein with a highly purified oxygen-evolving photosystem ii core complex from synechococcus vulcanus. | a highly purified, native photosystem ii (ps ii) core complex was isolated from thylakoids of synechococcus vulcanus, a thermophilic cyanobacterium by lauryldimethylamine n-oxide (ldao) and dodecyl beta-d-maltoside solubilization. this native ps ii core complex contained, in addition to the proteins that have been well characterized in the core complex previously purified by ldao and triton x-100, two more extrinsic proteins with apparent molecular weights of 17 and 12 kda. these two proteins we ... | 1992 | 1314738 |
| nmr studies on na+ transport in synechococcus pcc 6311. | the freshwater cyanobacterium synechococcus pcc 6311 is able to adapt to grow after sudden exposure to salt (nacl) stress. we have investigated the mechanism of na+ transport in these cells during adaptation to high salinity. na+ influx under dark aerobic conditions occurred independently of delta ph or delta psi across the cytoplasmic membrane, atpase activity, and respiratory electron transport. these findings are consistent with the existence of na+/monovalent anion cotransport or simultaneou ... | 1992 | 1314538 |
| complex formation between ferredoxin and ferredoxin-nadp+ reductase from anabaena pcc 7119: cross-linking studies. | ferredoxin-nadp+ reductase and ferredoxin from the cyanobacterium anabaena pcc 7119 have been covalently cross-linked by incubation with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. the covalent adduct, which shows a molecular mass consistent with a 1:1 stoichiometry of the two proteins, maintains nearly 60% of the nadph-cytochrome c reductase activity of the enzyme saturated with ferredoxin and this value is considerably higher than when equimolar amounts of both proteins are assayed. no ter ... | 1992 | 1314539 |
| oxygen-evolving photosystem ii preparation from wild type and photosystem ii mutants of synechocystis sp. pcc 6803. | we present here a simple and rapid method which allows relatively large quantities of oxygen-evolving photosystem ii- (ps-ii-) enriched particles to be obtained from wild-type and mutants of the cyanobacterium synechocystis 6803. this method is based on that of burnap et al. [burnap, r., koike, h., sotiropoulou, g., sherman, l. a., & inoue, y. (1989) photosynth. res. 22, 123-130] but is modified so that the whole preparation, from cells to ps-ii particles, is achieved in 10 h and involves only o ... | 1992 | 1311205 |
| isolation and sequence analysis of a gene encoding a basic cytochrome c-553 from the cyanobacterium anabaena sp. pcc 7937. | | 1992 | 1320427 |
| cytoskeletal changes in hepatocytes induced by microcystis toxins and their relation to hyperphosphorylation of cell proteins. | the heptapeptide toxins produced by the blue-green alga (cyanobacterium) microcystis aeruginosa are selectively hepatotoxic in mammals. the characteristic post-mortem pathology of the liver is extensive lobular disruption due to sinusoidal breakdown, leakage of blood into the tissue and hepatocyte disintegration. isolated hepatocytes incubated with toxin show severe structural deformity and surface blebbing. this paper demonstrates the effects of microcystis toxins on the contraction and aggrega ... | 1992 | 1370395 |
| a nitrate reductase gene of the cyanobacterium synechococcus pcc6301 inferred by heterologous hybridization, cloning and targeted mutagenesis. | dna probes from the narg gene of escherichia coli, which encodes the large polypeptide of respiratory nitrate reductase, show cross-hybridization at low stringency to a single region of the genome of the cyanobacterium synechococcus pcc6301. this segment of cyanobacterial dna was cloned as the insert of plasmid pdn1 and characterized. rna complementary to pdn1 was shown to be substantially more abundant in nitrate grown cells of synechococcus pcc6301 than in ammonium grown cells, thus parallelli ... | 1992 | 1378036 |
| copper-mediated regulation of cytochrome c553 and plastocyanin in the cyanobacterium synechocystis 6803. | in certain cyanobacteria and algae, cytochrome c553 or plastocyanin can serve to carry electrons from the cytochrome bf complex to photosystem i. the availability of copper in the growth medium regulates which protein is present. to investigate copper induced control of gene expression we isolated these proteins from the cyanobacterium synechocystis 6803. using immunodetection and optical spectroscopy, the steady state levels of cytochrome c553 and plastocyanin were measured in cells grown at di ... | 1992 | 1326543 |
| involvement of arginine residues in the allosteric activation and inhibition of synechocystis pcc 6803 adpglucose pyrophosphorylase. | adpglucose pyrophosphorylase (ec 2.7.7.27) from the cyanobacterium synechocystis pcc 6803 was desensitized to the effects of allosteric ligands by treatment with the arginine reagent, phenylglyoxal. enzyme modification by phenylglyoxal resulted in inactivation when the enzyme was assayed under 3p-glycerate-activated conditions. there was little loss of the catalytic activity assayed in the absence of activator. pi, 3p-glycerate, and pyridoxal-p were able to protect the enzyme from inactivation, ... | 1992 | 1326983 |
| evidence from directed mutagenesis that aspartate 170 of the d1 polypeptide influences the assembly and/or stability of the manganese cluster in the photosynthetic water-splitting complex. | to identify amino acid residues that influence the assembly or stability of the manganese cluster in photosystem ii, we have generated site-directed mutations in the d1 polypeptide of the cyanobacterium, synechocystis sp. pcc 6803. indirect evidence has suggested that the d1 polypeptide provides some of the ligands that are required for metal binding. mutations at position 170 of d1 were selected for characterization, since an aspartate to asparagine mutation (dn170d1) at this position completel ... | 1992 | 1322168 |
| allophycocyanin b (lambdamax 671, 618 nm): a new cyanobacterial phycobiliprotein. | a hitherto undescribed red fluorescent phycobiliprotein (maximum emission at congruent to 680 nm), characterized by long wavelength absorption maxima in the visible region at 671 nm (xi = 172000 m(-1).cm(-1) per monomer of mol. wt. 30600)and 618 nm, has been purified to homogeneity from unicellular cyanobacterium, synechococcus sp., and from a filamentous cyanobacterium, anabaena variabilis. the name allophycocyanin b has been proposed for the new protein. a. variabilis allophycocyanin b is ch ... | 1975 | 808186 |
| ultrastructural and chemical assessment of poly-beta-hydroxybutyric acid in the marine cyanobacterium trichodesmium thiebautii. | we report here on the occurrence and quantities of poly-beta-hydroxybutyric acid (phb) in natural populations of the marine cyanobacterium trichodesmium thiebautii. a diurnal variation in the shape and size of phb granules and in phb content was observed. the highest phb levels (2.3 +/- 0.8 mg g-1 dry wt) were recorded in the early morning and the values decreased thereafter with a minimum at night (1.6 +/- 0.9 mg g-1 dry wt). our data suggest that phb is a prominent cell constituent in t. thieb ... | 1992 | 1325936 |
| pathway of nitrogen metabolism after fixation of 13n-labeled nitrogen gas by the cyanobacterium, anabaena cylindrica. | methods have been developed for identifying the pathway of assimilation of n2-derived nitrogen. the products of fixation of 13n-labeled nitrogen gas ([13n]n2), and the distribution of 13n within glutamine, were determined after short periods of labeling (approximately 1 to 120 s) and also in pulse-chase experiments. ammonia, the amide nitrogen of glutamine, and the alpha-amino nitrogen of glutamate, in that order, were the first observed products of fixation of n2 by the cyanobacterium (blue-gre ... | 1976 | 821946 |
| [hydrogen metabolism in anabaena variabilis in the dark]. | cells and extracts of the cyanobacterium anabaena variabilis are capable of hydrogen absorption in the dark in the presence of h-acceptors with various redox potentials. preliminary adaptation of the cells to anaerobic conditions has no effect on the process. a. variabilis can also evolve hydrogen in the dark. reduced methylviologen (rmv), formiate, pyruvate, and glucose may be substrates for hydrogen evolution by the cells. the extracts evolve hydrogen in the presence of rmv, benzylviologen, az ... | 1976 | 824526 |
| identification, genetic analysis and characterization of a sugar-non-specific nuclease from the cyanobacterium anabaena sp. pcc 7120. | a nuclease that could be recovered from the supernatant of cultures, as well as from cell-free extracts, of the cyanobacterium anabaena sp. pcc 7120 was identified as a 29 kda polypeptide by its ability to degrade dna after electrophoresis in dna-containing sds-polyacrylamide gels. some clones of a gene library of strain pcc 7120 established in escherichia coli were found to produce the 29 kda nuclease. the nuca gene encoding this nuclease was subcloned and sequenced. the deduced polypeptide, nu ... | 1992 | 1343821 |
| molecular cloning and expression of the gene encoding adp-glucose pyrophosphorylase from the cyanobacterium anabaena sp. strain pcc 7120. | previous studies have indicated that adp-glucose pyrophosphorylase (adpglc ppase) from the cyanobacterium anabaena sp. strain pcc 7120 is more similar to higher-plant than to enteric bacterial enzymes in antigenicity and allosteric properties. in this paper, we report the isolation of the anabaena adpglc ppase gene and its expression in escherichia coli. the gene we isolated from a genomic library utilizes gtg as the start codon and codes for a protein of 48,347 da which is in agreement with the ... | 1992 | 1325205 |
| growth response of the nitrogen-fixing cyanobacterium westiellopsis prolifica janet to fertilizer factory effluents. | | 1992 | 1327314 |
| facultative anoxygenic photosynthesis in the cyanobacterium oscillatoria limnetica. | an isolate from h2s-rich layers of the solar lake, the cyanobacterium oscillatoria limnetica, exhibits both oxygenic and anoxygenic photosynthesis. it can use na2s as an electron donor for co2 photoassimilation (photosystem i supplies the energy) in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea or 700-nm light. a stoichiometric ratio of approximately 2 is observed between the na2s consumed and the photoassimilated co2. the anoxygenic phototrophic capability of this cyanobacterium expla ... | 1975 | 808537 |
| traveller's diarrhoea associated with cyanobacterium-like bodies. | | 1992 | 1354313 |
| heat shock protein synthesis of the cyanobacterium synechocystis pcc 6803: purification of the groel-related chaperonin. | synechocystis pcc 6803 cells could be induced to synthesize four major hsps with apparent molecular sizes of 70, 64, 15 and 14 kda. heat stress at 42.5 degrees c appeared to be the optimum temperature for hsp formation in cells grown at 30 degrees c. the relative rate of synthesis of hsp70 and hsp15 reached a maximum at 30 min after the temperature shift-up whereas the capability of cells to accumulate hsp64 and hsp14 continued through 2 h. the two most abundant hsps, hsp70 and hsp64, were recog ... | 1992 | 1346251 |
| thermally-induced delayed fluorescence of photosystem i and ii chlorophyll in thermophilic cyanobacterium synechococcus elongatus. | stationary delayed fluorescence (df) of chlorophyll in isolated membrane preparations from thermophilic cyanobacterium synechococcus elongatus was investigated as a function of temperature. two peaks at different temperatures were observed. the low-temperature peak (54-60 degrees c) coincided with the main maximum of the thermally-induced delayed fluorescence of chlorophyll in intact cells and psii-particles with active oxygen-evolving system. the high-temperature peak (78 degrees c) coincided w ... | 1992 | 1426973 |
| glutamine synthetase and nitrogen cycling in colonies of the marine diazotrophic cyanobacteria trichodesmium spp. | we examined freshly collected samples of the colonial planktonic cyanobacterium trichodesmium thiebautii to determine the pathways of recently fixed n within and among trichomes. high concentrations of glutamate and glutamine were found in colonies. glutamate and glutamine uptake rates and concentrations in cells were low in the early morning and increased in the late morning to reach maxima near midday; then uptake and concentration again fell to low values. this pattern followed that previousl ... | 1992 | 1359837 |
| structure determination and toxicity of a new microcystin from microcystis aeruginosa strain 205. | a new hepatotoxic microcystin was isolated from the cyanobacterium microcystis aeruginosa strain 205. its structure was found to be [dha7]microcystin-rr as determined by amino acid analysis, mass spectrometry and 1h nmr spectroscopy. ld50 value (i.p. mouse) of this toxin was 180 micrograms/kg. the 48 hr lethal concentration (48-hr-lc50) of the toxin for larvae of the yellow fever mosquito, aedes aegypti, was 14.9 micrograms/ml. | 1992 | 1440646 |
| molecular characterization of the gene encoding glutamine synthetase in the cyanobacterium calothrix sp. pcc 7601. | in order to study the regulation of the synthesis of glutamine synthetase in response to changes in environmental parameters (light and nitrogen sources), we have cloned and sequenced the glna gene from the filamentous cyanobacterium calothrix pcc 7601. this gene consists of 472 codons and encodes a polypeptide of m(r) 52,290 highly homologous to that from anabaena pcc 7120, but more distant from those identified from other procaryotes. the relative abundance of the two glna transcripts (1.6 and ... | 1992 | 1362348 |
| elucidation and optimization of the medium constituents controlling antibiotic production by the cyanobacterium nostoc muscorum. | a study has been made to determine which nutrient factors control antibiotic production by the cyanobacterium, nostoc muscorum. a two-phase approach was employed using a factorial method to explore the response surface and a steepest ascent method to climb the response surface to the region of the optimum. it was found that nitrate and iron were the factors significantly affecting antibiotic production; 26.4 mm nitrate and 6 microm iron were the optimal concentrations for maximizing antibiotic p ... | 1991 | 1367529 |
| structure and expression of a plastid-encoded groel homologous heat-shock gene in a thermophilic unicellular red alga. | a gene homologous to the e. coli groel locus was identified on the plastid genome of the unicellular red alga cyanidium caldarium strain 14-1-1 (synonym: galdieria sulphuraria). the complete nucleotide sequence was determined and compared to bacterial- and nuclear-encoded counterparts of higher plants. at the amino-acid level the c. caldarium gene shows 70% homology to the corresponding gene of the cyanobacterium synechococcus and 52% homology to nuclear-encoded counterparts of higher plants, re ... | 1992 | 1352188 |
| cloning and characterization of the secy gene from the cyanobacterium synechococcus pcc7942. | the secy gene product is an essential component of the escherichia coli cytoplasmic membrane, which mediates the protein translocation across the membrane. we found a gene homologous to secy in the genome of the cyanobacterium synechococcus pcc7942. the deduced amino acid sequence, 439 amino acids long, shows 43% homology with that of the e. coli secy. the hydrophobic profile suggests that the synechococcus secy protein is an integral membrane protein containing ten membrane-spanning segments, w ... | 1992 | 1420358 |