| 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 |
| effect of nadp on light-induced cytochrome changes in membrane fragments from a blue-green alga. | the effect of nadp+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragements prepared from the blue-green algae nostoc muscorum (strain 7119) that had high rates of electron transport from water to nadp+ and from an artificial electron donor, reduced dichlorophenolindophenol (dciph2) to ndap+. the membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. with dciph2 as the elec ... | 1976 | 2320 |
| some thermodynamic and kinetic properties of the primary photochemical reactants in a complex from a green photosynthetic bacterium. | we have examined the bacteriochlorophyll reaction-center complex of chlorobium limicola f. thiosulfatophilum, strain tassajara. our results indicate that the midpoint potential of the primary electron donor bacteriochlorophyll of the reaction center is +250 mv at ph 6.8, while that of cytochrome c-553 is +165 mv. there are two cytochrome c-553 hemes per reaction center, and the light-induced oxidation of each is biphasic (t1/2 of less than 5 mus and approximately 50 mus). we belive that this ind ... | 1976 | 2322 |
| presence of two subunit types in ribulose-1,5-bisphosphate carboxylase from blue-green algae. | | 1976 | 3179 |
| alanine dehydrogenase of the n2-fixing blue-green alga, anabaena cylindrica. | the l-alanine dehydrogenase (adh) of anabaena cylindrica has been purified 700-fold. it has a molecular weight of approximately 270,000, has 6 sub-units, each of molecular weight approximately 43,000, and shows activity both in the aminating and deaminating directions. the enzyme is nadh/nad+ specific and oxaloacetate can partially substitute for pyruvate. the kampp for nad+ is 14 mum and 60 mum at low and high nad concentrations respectively. | 1975 | 4043 |
| properties of heterocysts isolated with colloidal silica. | a method is described for the isolation of heterocysts that are virtually free of contaminating cell debris after sonication of aerobically grown anabaena 7120. isolated heterocysts reduced acetylene in a light-dependent process in the absence of exogenously provided atp; heterocysts supplied with atp and na2s2o4 reduced acetylene slowly in the dark but still showed a marked light activation. nitrogenase activity was greatest in fractions containing intact heterocysts. up to 13% of the activity ... | 1976 | 5981 |
| influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in kaneohe bay, hawaii. | nitrogen fixation was investigated in kaneohe bay, oahu, hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. no active, planktonic, n2-fixing blue-green algae or bacteria were observed. however, calothrix and nostoc capable of fixing n2 were cultured from navigational buoys and dead coral heads. nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. experiments demon ... | 1976 | 7198 |
| "synthetical" aiptasia mutabilis rapp (coelenterata) (author's transl). | after being cultivated in the dark for some months and after being fed with food free of carotenoids during the time aiptasia mutabilis (coelenterata) loses its symbiontic algae (rich in brown fucoxanthin) and becomes transparent white. this disarranged symbiosis may be regenerated under light cultivation by adding different species of chlorophyceae (chlorella, dunaliella) and chrysophyceae (ochromonas, cyclotella), but not of cyanophyceae (anabaena, nostoc, oscillatoria, anacystis). - this chan ... | 1976 | 8888 |
| photolysis of water coupled to nitrate reduction by nostoc muscorum subcellular particles. | | 1976 | 9086 |
| photosystem ii regulation of macromolecule synthesis in the blue-green alga aphanocapsa 6714. | polymers synthesized by heterotrophically growing (glucose as carbon source) cultures of aphanocapsa 6714 were compared with polymers synthesized in photosynthetically grown cultures. loss of photosystem ii by dark incubation, or inhibition of light-grown cells with the photosystem ii-specific inhibitor dichlorophenylmethylurea, caused an 80 to 90% reduction in the rate of lipid and total ribonucleic acid synthesis, and more than a 90% reduction in the rate of protein synthesis. in contrast, gl ... | 1976 | 10279 |
| formation of glutamine from 13nammonia, 13ndinitrogen, and 14cglutamate by heterocysts isolated from anabaena cylindrica. | a method is described for the isolation of metabolically active heterocysts from anabaena cylindrica. these isolated heterocysts accounted for up to 34% of the acetylene-reducing activity of whole filaments and had a specific activity of up to 1,560 nmol of c2h4 formed per mg of heterocyst chlorphyll per min. activity of glutamine synthetase was coupled to activity of nitrogenase in isolated heterocysts as shown by acetylene-inhibitable formation of 13nnh3 and of amidelabeled 13nglutamine form 1 ... | 1977 | 14927 |
| penicillinase (beta-lactamase) formation by blue-green algae. | beta-lactamase (penicillinase) activity was found in a number of strains of blue-green algea. in some cases, this enzyme permitted algae to overcome the inhibitory effects of penicillin. production and localization of beta-lactamase were studied in a unicellular species, coccochloris elabens (strain 7003), and in a filamentous, nitrogen-fixing anabaena species (strain 7120). when cells were grown in a neutral medium with nano3 as n source, the ph rose during growth; at a ph of about 10, most of ... | 1977 | 15530 |
| acetate uptake by the unicellular cyanobacteria synechococcus and aphanocapsa. | | 1977 | 18124 |
| effect of physical and chemical agents on the blue-green algal virus n-1. | the stability of the blue-green algal virus n-1, infecting the blue-green alga nostoc muscorum, against temperature, edta and ph was studied. ninety per cent thermal inactivation of virus occured at 55 degrees c in 20 minutes with an average inactivation rate constant of 0.07 per minute; at 60 degrees c the virus was completely inactivated within 5 minutes. 10(-4) m edta inactivated 30 per cent of free virus in 60 minutes; 10(-3) m edta was completely lethal. intracellular virus was comparativel ... | 1977 | 18927 |
| role of phycobilin pigments in photosynthesis. | experimental data on possible role of phicobilliprotein (phbp) in photosynthesis are analysed. it is concluded that the widely spread notion about phbp only as the light-gathering pigments which transfer the energy to chlorophyll, turned to be insufficiently substantiated experimentally until recently. at the same time the discovered ability of phbp for reversible redox transformations together with the new data on the nature of fluorescence of blue-green algae and phbp localization in the cell ... | 1977 | 19089 |
| dependence of sulphate uptake by anacystis nidulans on energy, on osmotic shock and on sulphate stravation. | sulphate uptake by anacystis nidulans under aerobic conditions in the light was found to be sensitive to metabolic poisons, such as n,n'-dicyclohexylcarbodiimide and carbonyl cyanide m-chlorophenyl hydrazone. it was also depressed by darkness. the sulphate absorption is an energy-dependent process. sulphate uptake was also inhibited by chromate and selenate. osmotic shock strongly affected sulphate uptake. this effect could be interpreted by a loss of a binding protein involved in the absorption ... | 1977 | 20862 |
| 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 |
| the azolla-anabaena azzolae symbiosis. | | 1977 | 21650 |
| hydrogenase in n2-fixing cyanobacteria. | | 1978 | 23725 |
| glucose-6-phosphate dehydrogenase of anabaena sp. kinetic and molecular properties. | the kinetic and molecular properties of cyanobacterial glucose-6-phosphate dehydrogenase, partly purified from anabaena sp. atcc 27893, show that it undergoes relatively slow, reversible transitions between different aggregation states which differ in catalytic activity. sucrose gradient centrifugation and polyacrylamide gel electrophoresis reveal three pincipal forms, with approximate molecular weights of 120 000 (m1), 240 000 (m2) and 345 000 (m3). the relative catalytic activities are: m1 les ... | 1978 | 23737 |
| hydrogen production by anabaena cylindrica: effects of varying ammonium and ferric ions, ph, and light. | anabaena cylindrica sparged with argon gas produced h2 continuously for 30 days under limited light conditions (6.0 w/m2) and for 18 days under elevated light conditions (32 w/m2) in the absence of exogenous nitrogen. the efficiency of converting visible light energy (32 w/m2) into chemical energy that is trapped as h2 ranged between 0.35 and 0.85% (approximately 13 microliter of h2 per mg drywt per h). ammonium additions (0.2 mm nh4+) at various times destabilized the system and eventually supp ... | 1978 | 25622 |
| effects of host aging, ions, and ph on the adsorption of the cyanovirus n-1 to nostoc muscorum. | the adsorption rate of the cyanovirus n-1 infecting the nitrogen-fixing blue-green alga nostocmuscorum decreased with aging of algal cultures and the virus failed to adsorb to the dead host cells. the adsorption rate declined in saline magnesium chloride solution compared to that in algal growth medium. the addition of amino acids like l-tryptophan and l-phenylalanine failed to enhance the adsorption rate of the virus. optimal ph of adsorption was 7.6 to 8;1. | 1978 | 25636 |
| modes of reduction of nitrogen in heterocysts isolated from anabaena species. | n2 fixation (acetylene reduction) has been studied with heterocysts isolated from anabaena cylindrica and anabaena 7120. in the presence of atp and at very low concentrations of sodium dithionite, reducing equivalents for activity of nitrogenase in these cells can be derived from several compounds. in the dark, d-glucose 6-phosphate, 6-phosphogluconate and dl-isocitrate support acetylene reduction via nadph. in the light, reductant can be generated by photosystem i. | 1978 | 26392 |
| photosynthetic electron transport and phosphorylation reactions in thylakoid membranes from the blue-green alga anacystis nidulans. | thylakoid membranes were prepared from the blue-green alga, anacystis nidulans with lysozyme treatment and a short period of sonic oscillation. the thylakoid membrane preparation was highly active in the electron transport reactions such as the hill reactions with ferricyanide and with 2,6-dichlorophenolindophenol, the mehler reaction mediated by methyl viologen and the system 1 reaction with methyl viologen as an electron acceptor and 2,6-dichlorophenolindophenol and ascorbate as an electron do ... | 1978 | 26396 |
| 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 |
| effects of amino acids, adenine nucleotides and inorganic pyrophosphate on glutamine synthetase from anabaena cylindrica. | glutamine synthetase (l-glutamate:ammonia ligase (adp-forming), ec 6.3.1.2) from anabaena cylindrica was inhibited by alanine, glycine, serine and aspartate. the effects of alanine and serine were uncompetitive with respect to glutamate, while those of glycine and asparatate were uncompetitive with respect to glutamate, while those of glycine and aspartate were non-competitive and mixed type respectively. different pairs of amino acids and their various combinations caused a cumulative inhibitio ... | 1978 | 31917 |
| [characteristics of the proteins of unicellular organisms as potential components of ecological life-support systems]. | a comparative characterization of the biological value of proteins from green and blue-green algae, bacteria, and microbial coenosis of straw mineralizing active sludge is given with respect to the fractional composition of total protein, its amino acid composition, and affinity for proteolytic enzymes in vitro. the above microorganisms have an adequate amino acid composition, a high content of essential amino acids, and differ in their content of readily soluble proteins. the presence of protei ... | 1979 | 36502 |
| from extracellular to intracellular: the establishment of mitochondria and chloroplasts. | paracoccus and rhodopseudomonas are unusual among bacteria in having a majority of the biochemical features of mitochondria; blue-green algae have many of the features of chloroplasts. the theory of serial endosymbiosis proposes that a primitive eukaryote successively took up bacteria and blue-green algae to yield mitochondria and chloroplasts respectively. possible characteristics of transitional forms are indicated both by the primitive amoeba, pelomyxa, which lacks mitochondria but contains a ... | 1979 | 36620 |
| utilization of seawater-urea as a culture medium for spirulina maxima. | the possibilities of utilization of seawater enriched with ureas as the culture medium for a blue-green alga, spirulina maxima, were investigated. pretreatment by precipitation with nahco3 and (or) na2co3 was found essential to remove the excess amounts of ca2+ and mg2+ present in seawater prior to cultivation. a culture medium as good as the synthetic medium reported in the literature for the growth of s. maxima was obtained after treating seawater with nahco3 (19.2 g/l) at ph 9.2 and 35 degree ... | 1979 | 38896 |
| the purification of glutamine synthetase from azotobacter and other procaryotes by blue sepharose chromatography. | we report the facile purification of glutamine synthetase (l-glutamate: ammonia ligase (adenosine 5'-diphosphate-forming), ec 6.3.1.2) in both the adenylylated and unadenylylated form, from azotobacter vinelandii atcc 12837. a general affinity column, which used as an affinity ligand reactive blue 2 dye (cibacron blue) covalently linked to agarose, was employed as an efficient first step of purification. further purification to electrophoretic homogeneity employed deae-cellulose chromatography a ... | 1979 | 39606 |
| 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 |
| carbon dioxide assimilation in cyanobacteria: regulation of ribulose, 1,5-bisphosphate carboxylase. | cyanobacteria assimilate carbon dioxide through the calvin cycle and therefore must regulate the activity of ribulose 1,5-bisophosphate carboxylase. using an in situ assay, as well as measuring the activity in crude, partially purified, and homogeneous preparations, we can show that a number of phosphorylated intermediates exert a regulatory role. three diverse organisms, agmenellum quadruplicatum, aphanocapsa 6714, and anabaena sp. ca, were studied, and it was found that the in situ and cell-fr ... | 1979 | 40958 |
| regulatory characteristics of a fructose bisphosphatase from the blue-green bacterium anacystis nidulans. | | 1979 | 41483 |
| measurement of the aquatic toxicity of volatile nitrosamines. | the acute toxicity of n-nitrosodimethylamine (dmn) and n-nitrosodiethylamine (den) was determined for three groups of aquatic organisms: algae, invertebrates, and fish. toxicity of dmn and den to algae was assessed as a repression in the growth rate of either selenastrum capricornutum or anabaena flos-aquae in static bioassay tests. dmn and den concentrations of 1-10 ppm depressed algal growth in all cases. invertebrate toxicity was determined in 96-h static bioassay tests with dugesia dorotocep ... | 1979 | 43403 |
| a phenomenon of photoenhancement of acridine orange-induced fluorescence. | it is a common experience that, with exposure to exciting radiation of the fluorescence microscope, the acridine orange-induced red fluorescence of the nucleus, produced by feulgen hydrolysis, fades with a concomitant shift to green. the present investigation reports a phenomenon of photoenhancement observed in the hydrolyzed cytoplasm where pale green fluorescence increases in intensity with exposure to exciting radiation. the phenomenon has been noticed in rhizobium, oscillatoria, tomato root ... | 1976 | 58929 |
| estimation of chlorophyll a distribution in the photosynthetic pigment systems i and ii of the blue-green alga anabaena variabilis. | chlorophyll a distribution in pigment systems i and ii was estimated with the blue-green alga anabaena variabilis by two methods: first, with intact cells using delayed light emission as an index reaction; second, by measuring the 2,6-dichlorophenolindophenol-hill reaction and the cytochrome c photooxidation in membrane fragments. the first estimation indicated that 0.053+/-0.014 of total chlorophyll a functions as a component of pigment system ii, and the second method 0.086+/-0.012. though the ... | 1977 | 66064 |
| phosphate metabolism in blue-green algae. iii. the effect of fixation and post-staining on the morphology of polyphosphate bodies in plectonema boryanum. | | 1977 | 70323 |
| estimation of internal ph in cells of blue-green algae in the dark and under illumination. | carbonylcyanide m-chlorophenylhydrazone (cccp) or nigericin induced translocation of h+ in the dark across the cell membrane of blue-green algae plectonema boryanum and anacystis nidulans. the direction of the h+ flux depended on the ph of the suspending medium. at acidic ph, an influx of h+ and at alkaline ph an efflux of h+ were observed. it is suggested that the influx takes place at ph's higher than the "internal" ph and the efflux at ph's lower than that. the internal ph was estimated to be ... | 1977 | 72067 |
| [polysaccharides of microorganisms]. | | 1978 | 78432 |
| pesticide (hexachlorocyclohexane) inhibition of growth and nitrogen fixation in blue-green algae anabaenopsis raciborskii and anabaena aphanizomenoides. | the effects of the pesticide hexachlorocyclohexane (hch) on the nitrogen fixing blue-green algae anabaenopsis raciborskii and anabaena aphanizomenoides commonly found as blooms in fish ponds were studied. these algae were very sensitive to hch, and a distinct decrease in growth rate was observed on prolonged incubation. lower concentrations (10 microgram/ml) were algistatic and higher concentrations (60 microgram/ml) were algicidal. the inhibition of nitrogen fixation indicated that the presence ... | 1978 | 80890 |
| extracellular release of organic products and growth of bacteria in anabaena cylindrica (blue-green alga) culture. | the studies were made with stationary cultures of anabaena cylindrica (blue-green alga). the bacterial microflora accompanying blue-green algae is subject to succession and elimination in the course of growth. the bacteria are able to utilize organic products released by the blue-green algae. the products released by a. cylindrica to the environment are peptide-like compounds. | 1978 | 81602 |
| [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 |
| [gas-vacuole-containing blue algae and their toxicity to animals]. | | 1978 | 95943 |
| 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 |
| continuous cultivation in a chemostat of the phototrophic procaryote, anacystis nidulans, under nitrogen-limiting conditions. | anacystis nidulans was grown photoautotrophically in a chemostat in the presence of light, air and co2 as the sole carbon source. either the amount of the nitrogen source in the medium or light intensity were used as growth-limiting parameters. 1. cells of high glycogen content obtained by pre-incubation under nitrogen starvation conditions maintained their glycogen content during continuous cultivation. both growth rate and the amount of cell-mass and of glycogen depended on the nitrate content ... | 1978 | 96328 |
| isolation of a sulphate reductase-less mutant of the blue-green alga nostoc muscorum. | the wild type nostoc muscorum (uw strain) has yielded various physiological mutants altered in utilization of sulphate, following mutagenic treatments with n-methyl, n'-nitro n-nitrosoguanidine (ntg). one of the mutant strains designated as sat-20 failed to grow in a medium containing sulphate (mgso4.7 h2o). however, the mutant strain could grow when supplemented with thiosulphate (na2s2o3.5 h2o), while methionine could fulfil the sulphur requirement only partially. on comparative reasons, the w ... | 1978 | 96618 |
| interaction of the nitrogenase components of anabaena cylindrica with those of clostridium pasteurianum. | | 1978 | 96817 |
| excitation energy transfer in anacystis nidulans. | | 1978 | 96822 |
| characterization of chromophoric peptides from c-phycocyanin. | | 1978 | 96831 |
| stimulation of nitrogenase by acetylene: fresh synthesis or conformational chance? | | 1978 | 96835 |
| 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 |
| effect of nutrients on the toxicity of pesticides carbofuran and hexachlorocyclohexane to blue-green alga nostoc muscorum. | the effects of various levels of nutrients like potassium phosphate (dibasic), calcium nitrate, and calcium chloride individually and in combinations were studied on the toxicity of the commonly used pesticides carbofuran and hexachlorocyclohexane (hch) in growth medium to the n2-fixing blue-green alga nostoc muscorum. it was observed that all these chemicals had some effects on toxicity. the toxicity of both carbofuran and hch was reduced to some extent in the presence of higher concentrations ... | 1979 | 94720 |
| [kinetics, mechanism and thermodynamics of cyanophage a-1 adsorption onto algal host cells]. | it is found that adsorption kinetics of cyanophage a-1 on algae anabaena variabilis cells is more complex than the reaction kinetics of the first order. an analysis of virus adsorption curves on cells and some other characteristics of this process have shown that virus a-1 is absorved on the algae-host cells according to adsorption concurrent model. some thermodynamic characteristics of the process studied are calculated. their values point to enzymatic character of the reaction of virus fasteni ... | 1978 | 96874 |
| hydrogen metabolism in blue-green algae. | this manuscript reviews the literature on hydrogen metabolism in blue-green algae and reports some new data from this laboratory. h2-formation by intact cells is found to be catalyzed exclusively by nitrogenase. its rate appears to be variable from strain to strain used byt is--in our hands--very small. therefore, blue-green algae are presumably of limited value in projects of solar energy conversion to form molecular hydrogen. these organisms are also able to consume the gas in a reaction catal ... | 1978 | 96876 |
| biological nitrogen fixation in the terrestrial environment of a high arctic ecosystem (truelove lowland, devon island, n.w.t.). | arranged in descending order of nitrogen-fixing (acetylene-reducing) potential the sites examined were mesic meadow and peat polygon troughs (equal rank), transition zone between mesic meadow and gravel ridge, gravel ridge, polar dessert, and peat polygon tops. the dominant nitrogen-fixing microorganisms, as in other arctic areas, were blue-green bacteria, especially those epiphytic on arctic mosses. the epiphytic association exhibited an optimum temperature for fixation of 20 degrees c. other b ... | 1978 | 96927 |
| biosynthesis of delta-aminolevulinic acid by blue-green algae (cyanobacteria). | when levulinic acid, a competitive inhibitor of delta-aminolevulinic acid dehydratase, was added to growing cultures of blue-green algae (cyanobacteria), delta-aminolevulinic acid was excreted into the medium and cell growth was inhibited. | 1978 | 97274 |
| the blue-green algae in nuclear power plant cooling water. | a study was undertaken to determine the effects of passage through the cooling system of the zion nuclear plant, illinois, u.s.a., on the blue-green algae present in lake water. the blue-green algae were isolated by means of membrane filtration, enumerated and identified to genera. as a result of cooling system passage there was a definite reduction in the numbers of blue-green algae. this reduction appeared to be due to mechanical, as well as elevated temperature, damage. a few genera showed on ... | 1978 | 97496 |
| [intracellular oxygen and the radiosensitization of cells of the blue-green alaga, anacystis nidulans]. | the photosynthetic system of the blue-green alga anacystis nidulans was inactivated by 30% at a dose of 100 krad of gamma irradiation in n2. if the cells were irradiated in n2+2% co2 in the light, their radiation sensitivity was increased with an oxygen enhancement ratio of 2.0. neither light nor co2 taken separately affected radiosensitization of the cells which increased almost to the same extent as under aerobic conditions in the presence of both light and co2. the intracellular oxygen of the ... | 1978 | 97503 |
| the cleavage site of the restriction endonuclease ava ii. | we have determined that the type ii restriction enzyme ava ii, isolated from anabaena variabilis, recognizes and cuts the sequence (formula: see article). the eight ava ii sites of pbr322 have been mapped, as well as a unique site for ava i. | 1978 | 97636 |
| the pattern of sporulation in anabaena circinalis and comments on the role of heterocysts in sporulation in blue-green algae. | cells between two intercalary heterocysts differentiate at random into spores in a. circinalis. one or more cells, which fail to transform into spores, are present between the two adjacent spores, and these cells disorganize later. a critical c:n ratio regulates sporulation and heterocyst formation. during sporulation the reductive ability of the heterocyst gradually diminishes. it is concluded on the basis of this and other evidence that sporulation is regulated by interactions between heterocy ... | 1978 | 97869 |
| thermophilic methanogenesis in a hot-spring algal-bacterial mat (71 to 30 degrees c). | algal-bacterial mats which grow in the effluent channels of alkaline hot springs provided an environment suitable for studying natural thermophilic methane producing bacteria. methane was rapidly produced in cores taken from the meat and appeared to be an end product of decomposition of the algal-bacterial organic matter. formaldehyde prevented production of methane. initial methanogenic rate was lower and methanogenesis became exponential when samples were permitted to cool before laboratory in ... | 1978 | 98110 |
| intermittent illumination increases biophotolytic hydrogen yield by anabaena cylindrica. | intermittent illumination increased h2 and c2h4 yields per unit of light from growing cells and from nitrogren-starved cells by 1.7- and 1.35-fold, respectively, as compared with continuous illumination. | 1978 | 98111 |
| transient change in the atp pool of anabaena cylindrica associated with ammonia assimilation. | when n2-grown cells of anabaena cylindrica were exposed to ammonia (50 micron to 5 mm) in the dark, the size of the atp pool was reduced by 40% within 1 min, but restored after 5 or 6 min. the decrease in atp was accompanied by increases in adp and amp, while the total adenylate content remained unaltered. the ammonia-induced change in the atp pool was completely eliminated when algal cells were treated with l-methionine-dl-sulfoximine, an inhibitor of glutamine synthesis. these results suggest ... | 1978 | 98124 |
| effects of mosquito control insecticides on nitrogen fixation and growth of blue-green algae in natural plankton associations. | | 1978 | 98184 |
| the chemistry and biochemistry of nitrogen. | | 1978 | 98424 |
| 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 |
| physico-chemical and immunological properties of allophycocyanins. | allophycocyanins were purified from diverse cyanobacteria and one rhodophytan alga (cyanidium caldarium). the native proteins are trimeric molecules with the structure (alpha beta)3. representative native allophycocyanins and their alpha and beta subunits were characterized with respect to molecular weight, amino acid composition, isoelectric point, absorption and fluorescence spectra and immunological properties. all of the allophycocyanins studied were strikingly similar with respect to each o ... | 1977 | 65163 |
| inhibition of photosynthetic electron transport in tobacco chloroplasts and thylakoids of the blue green alga oscillatoria chalybea by an antiserum to synthetic zeaxanthin. | an antiserum to synthetic zeaxanthin inhibits photosynthetic electron transport on the oxygen-evolving side of photosystem ii in tobacco chloroplasts and thylakoids of the filamentous blue-green alga oscillatoria chalybea. the inhibition site lies for both species between the site of electron donation of water or tetramethyl benzidine and that of diphenyl carbazide or manganese ii ions. typical photosystem i reactions are not impaired by the antiserum. the effect of the antiserum concerning the ... | 1979 | 44593 |
| 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 |
| nitrogen-fixing communities in an intertidal ecosystem. | nitrogen gixation (acetylene reduction) associated with various communities in the intertidal sand and mud flat was measured in situ. areas which were colonized by algae, plants, and animals generally had significantly higher activities than areas which were visibly uncolonized. the highest activities were measured at sites colonized by a mixed bloom of oscillatoria-euglena-photosynthetic bacteria. these areas occupied only about 1% of the surface of the sediments, yet contributed nearly 50% of ... | 1978 | 99219 |
| 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 |
| uptake and accumulation of putrescine and its lethality in anacystis nidulans. | the rate of uptake of putrescine by anacystis nidulans has been shown to depend on the external ph and the extracellular concentration of putrescine. accumulation of exogenous putrescine was also proportional to the concentration of putrescine in the medium, suggesting that putrescine uptake was not subject to cellular regulation. an equation was derived to test the hypothesis that putrescine accumulation was due to ion trapping. comparison of the predicted and observed intracellular concentrati ... | 1979 | 40225 |
| 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 |
| effect of ph, light intensity and population on the toxicity of the pesticide carbofuran to the blue-green alga nostoc muscorum. | the effect of ph, light intensity and population on the toxicity of the pesticide furadan (containing 3% carbofuran as the active ingredient) was studied on the nitrogen fixing blue-green alga nostoc muscorum. it was observed that all these factors had effects on the toxicity of the pesticide. the blue-green alga grew better in the ph range of 7.5-10, whereas the acidic ph of 5-6 retarded growth. the pesticide was more toxic to alga in the medium of ph 5-6, whereas reduction in toxicity was noti ... | 1978 | 36544 |
| the site of inhibition of photosystem ii by 3-(3,4-dichlorophenyl)-n-n'-dimethylurea in thylakoids of the cyanobacterium anabaena cylindrica. | | 1978 | 100110 |
| a rapid and convenient method for purification and isolation of chlorophyll-a from porphyra yezoensis. | | 1978 | 100111 |
| effects of 5-hydroxylysine on acetylene reduction and nh4+-assimilation in the cyanobacterium anabaena cylindrica. | | 1978 | 100112 |
| immunological relationship between phycoerythrins from various blue-green algae. | | 1978 | 100412 |
| [photoevolution of hydrogen by anabaena cylindrica cyanobacteria]. | | 1978 | 100667 |
| 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 |
| superoxide dismutase and catalase in the protection of the proton-donating systems of nitrogen fixation in the blue-green alga anabaena cylindrica. | 1. superoxide dismutase activity was present in the heterocysts and vegetative cells of anabaena cylindrica, but was always lower in the heterocysts. 2. no qualitative differences were found in the superoxide dismutase from the two cellular types. 3. catalase activity was also present in both cellular types. 4. most of the nadp reductase activity, as assayed with menadione or ferredoxin as electron acceptor, was localized within the heterocysts. 5. studies on h2 consumption showed that most of t ... | 1978 | 101210 |
| nitrogen and ammonia assimilation in the cyanobacteria: regulation of glutamine synthetase. | | 1979 | 36043 |
| automated acquisition and analysis of data from the photoelectric scanner of the model e analytical ultracentrifuge. | | 1978 | 26284 |
| differential elimination of phenol by diatoms and other unicellular algae from low concentrations. | | 1978 | 101258 |
| survey of extrachromosomal dna found in the filamentous cyanobacteria. | cleared lysates of 13 species of filamentous cyanobacteria were examined for the presence of extrachromosomal dna by using agarose gel electrophoresis and ethidium bromide staining. seven of the 13 species contained extrachromosomal covalently closed circular dna, and all but 1 species contained multiple elements. there was no correlation between the presence of extrachomosomal dna and either the range of metabolic activities found in the cyanobacteria or the differentiated cell types or structu ... | 1978 | 101520 |
| classes of anabaena variabilis mutants with oxygen-sensitive nitrogenase activity. | mutants of anabaena variabilis deficient in the envelope glycolipids of heterocysts have no or very low nitrogenase activity when assayed aerobically. revertants capable of aerobic growth on n2 have increased quantities of these glycolipids. among mutants which require fixed nitrogen for growth in air and which have a normal complement of glycolipids, one expresses high nitrogenase activity at low oxygen tension. three others show high nitrogenase activity only in the presence of dithionite and ... | 1978 | 101529 |
| phosphate metabolism in blue-green bacteria. v. factors affecting phosphate uptake in plectonema boryanum. | plectonema boryanum requires approximately 5 days of exposure to a culture medium lacking phosphorus to induce the "polyphosphate overplus" phenomenon. at ph9, phosphate uptake is greatest both from normal culture medium and from dilute salt solutions. phosphate uptake from dilute salt solutions was greatest when na+ or k+ are combined with ca2+ or ca2+ and mg2+. cells starved of phosphorus in the presence of a high concentration of k+ or ca2+ in the medium, and then allowed to take up phosphoru ... | 1978 | 25703 |
| 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 |
| h+ translocation in lysozyme-treated cells of the blue-green alga plectonema boryanum. difference between isotonically and hypotonically treated preparations and effects of divalent cations. | lysozyme-treated cells of a blue-green alga, plectonema boryanum, had an internal ph of 7.3+/-0.2 under isotonic and hypotonic conditions. this value was similar to that of untreated cells. the cccp-induced biphasic h+ change seen in the isotonic cells was not observed in the hypotonically treated cells. the biphasic time course remained in the hypotonic preparation if cacl2 or mgcl2 was added prior to the osmotic shock. it is suggested that the cells have two compartments of h+ concentration. t ... | 1977 | 21172 |
| [effect of sulfur-containing nucleotide peptide on the morphology and nucleic acid content in anabaena culindrica]. | the exogenous action of a sulphur-containing nucleotidepeptide on anabaena cylindrica caused an increase in the biomass of the alga by 76% as a result of acceleration of growth and larger dimensions of cells. the content of nucleic acids per cell also increased: that of dna by 40%, that of rna, by 11%. | 1978 | 101744 |
| [characteristics of the cellular ultrastructural organization of the chemoheterotrophic blue-green alga, chlorogloea fritschii]. | cellular ultrastructural organization was compared in photoautotrophic and chemoheterotrophic cultures of the blue-green alga chlorogloea fritschii mitra. cells at the fourth stage of the life cycle of the culture in the phase of growth were studied in both cases. the structure of thylakoids was the main object of investigation. the cells of investigation. the cells of chl. fritschii had a peculiar organization when they were cultivated in the dark on a medium containing glucose as a source of c ... | 1978 | 101746 |
| 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 |
| calcium and photosynthetic oxygen evolution in cyanobacteria. | calcium activation of oxygen evolution from french-press preparations of phormidium luridum is largely reversible upon removal of added ca(2+). activation occurs via a first-order binding with a dissociation constant of 2.8 mm. an 8-fold increase in oxygen evolution rate observed upon ca(2+) addition is accounted for by a 4-fold increase in the number of active photosynthetic units, and a doubling of turnover rate. while both ca(2+) and mg(2+) stimulate turnover, unit activation is ca(2+) specif ... | 1978 | 102341 |
| a high-potential redox component located within cyanobacterial photosystem ii. | the calcium-dependent oxygen evolution activity of preparations of phormidium luridum shows a marked selectivity in favor of ferricyanide over benzoquinone as hill oxidant. in addition, the rate of oxygen evolution increases with increasing solution redox potential over the range +350 to +550 mv vs. the standard hydrogen electrode. these properties pertain to both 3-(3,4-dichlorophenyl)-1,1-dimethylurea-sensitive and -insensitive fractions of the total oxygen evolution activity. neither changes ... | 1978 | 102342 |
| excitation energy transfer between pigment system ii units in blue-green algae. | efficiency in excitation energy transfer from closed to open reaction center ii in blue-green and red algae was estimated by the method developed by joliot and joliot (c.r. acad. sci. (1964) 258, 4622--4625) after slight modification; the number of open reaction centers ii was counted from the mean o2 yield of repetitive short flashes. the efficiency in energy transfer in chlorella pyrenoidosa was the same in our measurement as that reported by joliot and joliot (0.55 +/- 0.02). however, the val ... | 1978 | 102343 |
| homocysteine biosynthesis in green plants: studies of the homocysteine-forming sulfhydrylase. | | 1977 | 16903 |
| microtubules and microfilaments as major components of a phagocytic apparatus: the cytopharyngeal basket of the ciliate pseudomicrothorax dubius. | the cytopharyngeal basket of pseudomicrothorax dubius, through which filamentous blue-green algae are ingested, consists of 22 (+/- 3) nemadesmata and nemadesmal lamellae, in the form of a tube. a cytostome, delimited by the cell membrane and surrounded by 22 (+/- 3) major and minor cortical corrugations, covers the end of the basket where the latter is attached to the cell cortex. each nemadesm, at its greatest diameter, consists of about 200 microtubules which are joined together by sheet-like ... | 1978 | 102557 |
| affinity chromatography of anacystis nidulans ferredoxin nitrate reductase and nadp reductase on reduced ferredoxin-sepharose. | | 1978 | 103462 |
| specific enzymatic determinations of adenosine triphosphate. | | 1978 | 103463 |
| glyceraldehyde-3-phosphate dehydrogenase of scenedesmus obliquus. effects of dithiothreitol and nucleotide on coenzyme specificity. | nadh-dependent glyceraldehyde-3-phosphate dehydrogenase (ec 1.2.1.--) of the photosynthetic alga scenedesmus obliquus is converted to an nadph specific form by incubation with dithiothreitol. the change in nucleotide specificity is accompanied by a reduction in the molecular weight of the enzyme from 550 000 to 140 000. prolonged incubation with dithiothreitol results in the further dissociation of the enzyme to an inactive 70 000 dalton species. the 140 000 dalton, nadph-specific enzyme is stab ... | 1977 | 15603 |