| 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 |
| 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 |
| "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 |
| isolation and characterization of two sequence-specific endonucleases from anabaena variabilis. | two endonucleases, avai and avaii, were isolated from anabaena variabilis on the basis of their ability to make a limited number of breaks at specific points in bacteriophage lambda dna. neither enzyme has cofactor requirements beyond mg2+. endonuclease avai makes eight breaks in the phage lambda chromosome at which the 5'-terminal sequence is ppy-c-g-n. avaii endonuclease cuts phage lambda dna more extensively, yielding fragments with the 5'-terminal sequence g-t-c-n or g-a-c-n. neither enzyme ... | 1976 | 11780 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| interaction of the nitrogenase components of anabaena cylindrica with those of clostridium pasteurianum. | | 1978 | 96817 |
| [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 |
| 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 |
| 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 |
| 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 |
| the site of inhibition of photosystem ii by 3-(3,4-dichlorophenyl)-n-n'-dimethylurea in thylakoids of the cyanobacterium anabaena cylindrica. | | 1978 | 100110 |
| effects of 5-hydroxylysine on acetylene reduction and nh4+-assimilation in the cyanobacterium anabaena cylindrica. | | 1978 | 100112 |
| [photoevolution of hydrogen by anabaena cylindrica cyanobacteria]. | | 1978 | 100667 |
| 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 |
| 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 |
| [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 |
| 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 new sequence-specific endonuclease from anabaena cylindrica. | | 1978 | 103749 |
| effect of rifampicin (3-(4-methylpiperazinyl-iminomethyl)rifamycin) on heterocyst differentiation in the blue-green algae anabaena and calothrix. | chains of multiple heterocysts form in anabaena und calothrix filaments on treatment with rifampicin. the multiple heterocysts form irrespective of whether the rifampicin treatment is given in combined nitrogen-free or supplemented medium. this suggests the possibility of involvement of a species of rna or of protein as intracellular heterocyst inhibitor and indicates that some latent pattern-determining mechanism may operate in the combined nitrogen medium. | 1978 | 104451 |
| effect of growth temperature on lipid and fatty acid compositions in the blue-green algae, anabaena variabilis and anacystis nidulans. | the lipid composition was affected by growth temperature in anacystis nidulans, but was not in anabaena variabilis. a. variabilis contained fatty acids of 18 and 16 carbon atoms, which were localized at 1- and 2-positions, respectively, of the glycerol moiety of lipids. desaturation of c18 acids was affected by the growth temperature. a. nidulans contained fatty acids of 14, 16 and 18 carbon atoms. monounsaturated and saturated acids were esterified mainly to 1- and 2-position, respectively. des ... | 1979 | 104734 |
| the polysaccharides from heterocyst and spore envelopes of a blue-green alga. structure of the basic repeating unit. | the polysaccharides from the envelopes of heterocysts and spores of anabaena cylindrica consist of repeating units containing 1 mannosyl and 3 glucosyl residues, all linked by beta(1 yields 3) glycosidic bonds, with glycosidic bonds, with glucose, xylose, galactose, and mannose present in side branches. degradation of the polysaccharides with specific glycosidases has permitted identification of the linkages to almost all of the branches. when the polysaccharides, from which all but two types of ... | 1979 | 104995 |
| 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 |
| [production of vitamin b 12 by a blue-green alga]. | in this study, we have been able to demonstrate the production and liberation of vitamin b12 (up to 16.5 pg/ml after 31 days of growth) by a blue green alga. anabaena flos-aquae, in non-axenic and axenic cultures. this finding has a relevant ecological significance since it shows that, like bacteria, blue green algae may play a role as producers of vitamin b12. | 1978 | 106945 |
| the differential action of metronidazole on nitrogen fixation, hydrogen metabolism, photosynthesis and respiration in anabaena and scenedesmus. | metronidazole (2-methyl-5-nitroimidazole-1-ethanol) at 1--2 mm levels has been shown to be a selective inhibitor of nitrogenase activity in anabanena. two constitutive hydrogenases and photosynthesis are insensitive to metronidazole at these same concentrations. at higher concentrations metronidazole inhibits photosynthesis in anabaena while photoreduction and to a lesser extent photohydrogen production are retarded in scenedesmus. respiration is slightly stimulated at high metronidazole levels ... | 1979 | 109115 |
| hydrogen evolution from immobilized cultures of the cyanobacterium anabaena cylindrica b629. | | 1979 | 109313 |
| two sequence-specific endonucleases from anabaena oscillariodes. | | 1979 | 109315 |
| 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 |
| photosynthetic vesicles with bound phycobilisomes from anabaena variabilis. | photosynthetically active vesicles with attached phycobilisomes from anabaena variabilis, were isolated and shown to transfer excitation energy from phycobiliproteins to f696 chlorophyll (photosystem ii). the best results were obtained when cells were disrupted in a sucrose/phosphate/citrate mixture (0.3 : 0.5 : 0.3 m, respectively) containing 1.5% serum albumin. the vesicles showed a phycocyanin/chlorophyll ratio essentially identical to that of whole cells, and oxygen evolution rates of 250 mu ... | 1979 | 110343 |
| effect of carbamoyl phosphate on nitrogenase in anabaena cylindrica lemm. | carbamoyl phosphate inhibited acetylene reduction by whole cells and cell-free extracts of anabaena cylindrica. higher levels of both endogenous carbamoyl phosphate and carbamoyl phosphate synthase activity were present in nh4+-grown cells (in which acetylene reduction was absent) than in n2-grown cells (in which acetylene reduction was present). however, inhibition of acetylene reduction was observed also with cyanate, the main initial decomposition product under the conditions used. it is conc ... | 1979 | 110775 |
| characteristics of anabaena variabilis influencing plaque formation by cyanophage n-1. | phage n-1 grown in anabaena strain 7120 [n-1 . 7120] forms plaques on a. variabilis about 10(-7) to 10(-6) as efficiently as on anabaena 7120. by manipulating different characteristics of the interaction between phage and host, it was possible to increase the relative efficiency of plaque formation to 0.38. growth of a. variabilis at 40 degrees c for at least three generations resulted in an increase in the rate of phage adsorption and a 10-fold increase in the efficiency of plaque formation. th ... | 1979 | 110787 |
| [resolution of the structure of the absorption spectrum of blue-green algae by a method of measuring the 2d derivative at -196 degrees c]. | by measuring the 2nd derivative at -196 degrees c the thin structure of the absorption spectrum of intact cells, isolated in phycobilisomes and pure pigments of blue-green algae anabaena variabilis and aphanizomanon flos-aquae is shown. 8 absorption bands in the region 669--710 nm pertaining to chlorophyll a in different aggregation region were found. almost the same number of bands were found in the region 550--660 nm. the latter were conditioned by the absorption of allophycocyanin, phycocyani ... | 1979 | 111718 |
| 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 |
| pharmacology of anatoxin-a, produced by the freshwater cyanophyte anabaena flos-aquae nrc-44-1. | | 1979 | 112722 |
| average thickness of the gas vesicle wall in anabaena flos-aquae. | | 1979 | 113551 |
| a mutant of anabaena sp. ca with oxygen-sensitive nitrogenase activity. | | 1979 | 114179 |
| accumulation of ppgpp and pppgpp during nitrogen deprivation of the cyanophyte anabaena cylindrica. | | 1979 | 115718 |
| mutants of anabaena strain ca altered in their ability to grow under nitrogen-fixing conditions. | mutants of anabaena strain ca impaired in nitrogenase activity and growth on n2 were isolated and characterized. one mutant was selected for resistance to l-methionine-dl-sulfoximine, and others were selected for resistance to dl-7-azatryptophan or for requirements for combined nitrogen. the mutants varied in sensitivity of growth and nitrogenase activity to atmospheric 02. several of the mutants whose growth on n2 was impaired under aerobic conditions could grow and reduce acetylene at rates co ... | 1979 | 115843 |
| [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 |
| synthesis of nitrogenase and heterocysts by anabaena sp. ca in the presence of high levels of ammonia. | anabaena sp. ca fails to synthesize heterocysts and nitrogenase when grown with kno3 as the nitrogen source. by contrast, both heterocysts and proheterocysts are synthesized in nh4cl-containing media to a level nearly commensurate with cells grown in the absence of combined nitrogen. the growth rate of the organism in nh4cl-containing media was similar to that obtained with kno3 as the nitrogen source and was independent of the presence of n2 in the atmosphere. thus, our results indicate that th ... | 1979 | 118162 |
| [blooming and destruction of cyanobacteria in the drainage bassin of the hydrogen sulfide spring of staraya matsesty]. | the growth of cyanobacteria belonging to the genera oscillatoria and anabaena (up to 2.1 x 10(7) filaments per 1 g of wet sample) was found in a water reservoir with a high content of sulfides (up to 9 mm) in staraya matsesta throughout the year. the spots of oscillatoria are located in the spring in more illuminated areas as compared to anabaena. in the spring, not only spots of actively growing cells were detected, but also accumulations of oscillatoria cells being destroyed (blue spots). wate ... | 1979 | 119145 |
| effect of mercuric ion on the growth, photosynthesis, and nitrogenase activity of anabaena inaequalis. | anabaena inaequalis was sensitive to mercuric ion (hg2+) in the ppb (nanogram per milliliter) range. growth was inhibited significantly at concentrations of metal ion as low as 2 ppb, and 100 ppb was required to inhibit photosynthesis and acetylene reduction. low levels of hg2+ stimulated acetylene reduction and photosynthesis. the lysis of vegetative cells was the primary action of mercuric ions, resulting in the inhibition of growth, photosynthesis, and nitrogenase activity. there was a linear ... | 1979 | 119487 |
| effect of tryptophan analogues on lipid metabolism in the cyanobacterium anabaena cylindrica [proceedings]. | | 1979 | 119656 |
| dissolved organic matter utilization and oxygen uptake in algal-bacterial microcosms. | under closed laboratory conditions, at non-limiting nutrient levels, the biomass of anabaena variabilis, anacystis nidulans, chlorella pyrenoidosa, and selanastrum capricornutum increased with increasing levels of dissolved organic matter (dom) as a result of bacterially produced carbon dioxide (co2) and (or) cofactors. oxygen (o2) produced as a result of algal photosynthesis was sufficient to supply the najority of o2 required by the bacterial community. the percentage of dom utilized by bacter ... | 1979 | 120219 |
| the effect of nickel on the growth, photosynthesis, and nitrogenase activity of anabaena inaequalis. | anabaena inaequalis was sensitive to nickel ion in the order of decreasing sensitivity of growth, photosynthesis, and acetylene reduction. at a culture density of 9 x 10(4) cells per millilitre, growth after 12 days was completely inhibited by 0.125 ppm (microgram/ml) ni2+. nickel caused the increase of both the lag phase of growth and the culture doubling time, and caused the retardation phase to be sooner. photosynthesis and acetylene reduction were completely inhibited by 10 and 20 ppm ni2+, ... | 1979 | 120221 |
| [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 |
| biochemical studies on sporulation in blue-green algae. i. glycogen accumulation. | glycogen accumulation in vegetative cells of anabaena sp. is demonstrated to be a light-dependent process. no glycogen accumulation is found in dark or in cultures supplemented with 10(-5) m dcmu in light. large quantities of glycogen accumulate in cells undergoing sporulation and the amount increased with the onset of maturation of spores. | 1979 | 121000 |
| phycobilisomes from the blue-green algae aphanizomenon flos-aquae and anabaena variabilis. | phycobilisomes (pbs) were isolated from aphanizomenon flos-aquae and anabaena variabilis. the absorption spectra and second derivative of the absorption spectra of isolated pbs indicate the presence of phycoerythrocyanin, and allophycocyanin. the fluorescence spectra of pbs were measured at room temperature and -196 degrees c. undamaged pbs have the principal fluorescence maximum in the region of 660 nm at room temperature and in the region of 685-690 nm at -196 degrees. when the pbs were heated ... | 1979 | 121545 |
| [molecular nitrogen fixation in eutrophic beloye ozero]. | the rate of production and mineralization of organic matter and the rate of fixation of molecular nitrogen were assayed in th eutrophic lake beloye (near moscow) at the end of summer stagnation (1976). the content of hydrogen sulphide reached 6.8 mg per litre which resulted in a change of the ecological environment in the lake. the fixation of molecular nitrogen in water layers was characterized by three maxima: 5.0 mcg n per litre per 4 hours (surface); 4.2 mcg n per litre per 4 hours (metalimn ... | 1978 | 148551 |
| crystalline structure of the gas vesicle wall from anabaena flos-aquae. | | 1976 | 184286 |
| the fine structure of a tri-lamellar body in various species of anabaena. | | 1976 | 184493 |
| epr spectra of photosystem i constituents in heterocyst preparations from anabaena cylindrica. | | 1976 | 186323 |
| fine structure of wall bodies in large cells of an anabaena species. | a new type of inclusion in blue-green algae termed a wall body is described. these are elongate bodies of medium electron density, from 6 to 70 nm in thickness and at least 0.2 micrometer in depth found in large cells of anabaena sp. b387. the bodies are up to 12 micrometer long, extending the complete length of the cell in some cases. some of the bodies are bifurcated and the ends appeared to come in contact with the plasma membrane. the wall bodies lie at various angles in the cells. up to six ... | 1977 | 205391 |
| [electron microscopic data on the mesosomelike and myelinlike structures of blue-green algae]. | the mesosome-like structures of blue-green algae were studied by freeze-etching without preliminary fixation and, in parallel, by a technique of ultrathin sections. these structures were found mainly in synechococcus elongatus and synechocystis aquatilis, less often, in anacystis nidulans and anabaena variabilis, and were not detected in plectonema boryanum. the following types of membrane structures were encountered: (1) formation consisting of three- and five-layered membranes and resembling t ... | 1978 | 212674 |
| paracrystalline inclusions in various isolates of the blue-green bacteria nostoc and anabaena. | a number of different crystalline inclusions were observed in various isolates of anabaena and nostoc. membrane-limited crystalline bodies were observed in 7 of 20 isolates of anabaena and 19 of 29 isolates of nostoc. these are spherical, single membrane-limited bodies from 0.6 to 0.1 micron in diameter. in most of the isolates they contained needle-like crystals 20 a in thickness and up to 80 nm in length. in 9 of the isolates the inclusions contained granular and fibrillar material. the number ... | 1978 | 223816 |
| a new specific endonuclease from anabaena variabilis. | | 1979 | 225204 |
| epr spectra of photosystem i and other iron protein components in intact cells of cyanobacteria. | electron paramagnetic resonance (epr) spectra were recorded of whole filaments of the cyanobacteria nostoc muscorum and anabaena cylindrica. signals due to manganese were removed by freezing and thawing the cells in edta. epr spectra were assigned on the basis of their g values, linewidths, temperature dependence and response to dithionite and light treatments. the principal components identified were: (i) rhombic fe3+ (signal at g = 4.3), probably a soluble storage form of iron; (ii) iron-sulfu ... | 1979 | 228708 |
| 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 |
| effects of l-methionine-dl-sulphoximine on the assimilation of newly fixed nh3, acetylene reduction and heterocyst production in anabaena cylindrica. | | 1975 | 239712 |
| hydrogen production by nitrogen-starved cultures of anabaena cylindrica. | nitrogen-starved cultures of the alga anabaena cylindrica 629 produced hydrogen and oxygen continuously for 7 to 19 days. hydrogen production attained a maximum level after 1 to 2 days of starvation and was followed by a slow decline. the maximum rates were 30 ml of h2 evolved per liter of culture per h or 32 mul of h2 per mg of dry weight per h. in 5 to 7 days the rate of h2 evolution by the more productive cultures fell to one-half its maximum value. the addition of 10(-4) to 5 x 10(-4) m ammo ... | 1977 | 402109 |
| 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 |
| 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 |
| the cell content and secretion of water-soluble vitamins by several freshwater algae. | three green algae, chlamydomonas reinhardii, chlorella vulgaris and scenedesmus obliquus, and one blue-green alga, anabaena cyclindrica, were grown in chemically defined media. all the algae examined contained folates, beta-carotene and vitamins c and e; several of the b-vitamins and vitamin a were found in varying amounts in some but not in all the algae examined. all the green algae secreted significant amounts of folate and biotin and all but scenedesmus secreted pantothenate into their growt ... | 1977 | 402897 |
| composition of a photosystem i chlorophyll protein complex from anabaena flos-aquae. | the use of triton x-100 to solubilize membrane fragments from anabaena flos-aquae in conjunction with deae cellulose chromatography allows the separation of three green fractions. fraction 1 is detergent-solubilized chlorophyll, and fraction 2 contains one polypeptide in the 15 kdalton area. fraction 3, which contains most of the chlorophyll and shows p-700 and photosystem i activity, shows by sds gel electrophoresis varying polypeptide profiles which reflect the presence of four fundamental ban ... | 1977 | 402941 |
| action of alkylating agents on nitrogen fixation by clones of anabaena doliolum bharadwaja. | | 1977 | 403090 |
| 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 |
| isolation and characterization of gas vesicles from microcyclus aquaticus. | intact gas vesicles of microcyclus aquaticus s1 were isolated by using centrifugally accelerated flotation of vesicles and molecular sieve chromatography. isolated gas vesicles were cylindrical organelles with biconical ends and measured 250x100nm. the gas vesicle membrane was composed almost entirely of protein; neither lipid nor carbohydrate was detected, although one mole of phosphate per mole of protein was found. amino acid analysis indicated that the protein contained 54.6% hydrophobic ami ... | 1977 | 403898 |
| temperature dependence on the delayed fluorescence of chlorophyll a in blue-green algae. | 1. the delayed fluorescence of chlorophyll a was measured with a phosphoroscope by changing the temperature in a range of room temperatures in intact cells of blue-green algae, anacystis nidulans, two strains of anabaena variabilis and plectonema boryanum, and other kinds of algae, cyanidium caldarium and chlorella pyrenoidosa. the induction of delayed fluorescence remarkably depended on the temperature of measurment. nevertheless, the induction pattern was characterized by three levels of inten ... | 1977 | 403943 |
| two laboratory case studies on the oral toxicity to calves of the freshwater cyanophyte (blue-green alga) anabaena flos-aquae nrc-44-1. | | 1977 | 404019 |
| chemical analysis of the phenol-water-extractable materials from anabaena flos-aquae. | the high molecular-weight carbohydrate substances extracted in the aqueous and phenol phases by phenol-water extraction of anabaena flos-aquae a-37 were found to be polysaccharides without lipid attached. | 1977 | 404287 |
| [electron microscopic study of dark and photo-oxidative degradation of the blue-green alga anabaena variabilis]. | changes in the cell ultrastructure were studied during incubation of the obligate phototrophic blue-green alga anabaena variabilis in the dark for a long time. the cells lost viability though their cell wall and cytoplasmic membrane were preserved; however, certain regions of the mureine layer were thickened in some cells. the membranes of the photosynthetic apparatus separate forming intrathylakoid spaces and the cytoplasm density decreases revealing phycobilisomes. during incubation in the dar ... | 1977 | 404506 |
| induction of phycoerythrin in anabaena ambigua rao and its strains. | | 1977 | 405243 |
| effects of adenine nucleotides and phosphate on adenosine triphosphate sulphurylase from anabaena cylindrica. | production of adenosine 5'-[35s]sulphatophosphate by a partially purified atp sulphurylase from anabaena cylindrica was inhibited by amp, adp and p1. decreases in enzyme activity in the presence of these inhibitors were reversed by increasing the concentrations of atp. the adenine nucleotides inhibited the enzyme competitively with respect to atp. in the presence of p1, atp showed a positive co-operative effect on enzyme activity. the inhibition by p1 was enhanced by increasing concentrations of ... | 1977 | 406902 |
| [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 |
| [epiphase carotenoids of the blue-green alga anabaena variabilia]. | epiphase carotenoids were studied in the cells of the obligate phototrophous blue-green alga anabaena variabilis. ten pigment zones were detected by column chromatography on alumina and by tlc on cellulose and silufol uv-254 plates. tlc in the b layer and paper chromatography did not reveal all pigment zones obtained on a column. the data of tlc on cellulose and on silufol plates confirmed the purity and individual character of the fractions obtained on a column. these data showed also that the ... | 1977 | 408584 |
| [hypophase carotenoids and the structure of epiphase carotenoids of anabaena variabilis]. | four major and three minor carotenoids of the glucoside nature were isolated by column and thin-layer chromatography on cellulose from the hypophase fraction of the pigment extract of anabaena variabilis growing for 8 days. one of these major pigment components was supposed to be myxoxanthophyll. the structure of some epiphase carotenoids of anabaena variabilis was established. the following pigments were also found to be present in the cell: beta-carotene, echinenone, neoechinenone u, and 3'-hy ... | 1977 | 409908 |
| [relation of the growth of anabaena variabilis cyanophages to photosynthesis and respiration]. | cyanophages a-1 (l) and a-4c (l) grow within the cells of anabaena variabilis under aerobic conditions in the dark in the presence of endogenous or exogenous (surcose) sources of energy. dnp inhibits the growth of cyanophages in the light and almost completely supresses it in the dark, o-phenanthroline entirely supresses the growth in both cases. dcmu has almost no effect on the yield of the virus in the light. virus particles can apparently be synthesized at the account of the energy of both ox ... | 1977 | 409909 |
| the utilization of molecular hydrogen by the blue-green alga anabaena cylindrica. | | 1977 | 410380 |
| 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 |
| preliminary crystallographic investigations of two phycobiliproteins. | single crystal x-ray diffraction investigations are in progress on two phycobiliproteins. c-phycocyanin from anabaena variabilis crystallizes in space group p63 with a = b = 154 a and c = 40 a. the crystallographic asymmetric unit is (alphabeta)2 with a total molecular mass of 7.0-10(4) daltons. b-phycoerythrin from porphyridium cruentum crystallizes in space group r3 with a = b = 189 a and c = 60 a. this molecule has the unusual molecular stoichiometry (alphabeta)6gamma and the crystallographic ... | 1977 | 410813 |
| anaerobic and aerobic hydrogen gas formation by the blue-green alga anabaena cylindrica. | an investigation was made of certain factors involved in the formation of hydrogen gas, both in an anaerobic environment (argon) and in air, by the blue-green alga anabaena cylindrica. the alga had not been previously adapted under hydrogen gas and hence the hydrogen evolution occurred entirely within the nitrogen-fixing heterocyst cells; organisms grown in a fixed nitrogen source, and which were therefore devoid of heterocysts, did not produce hydrogen under these conditions. use of the inhibit ... | 1977 | 412467 |
| effects of long-term treatment with acetylene on nitrogen-fixing microorganisms. | long periods of experimental incubation with acetylene led to a multifold enhancement of acetylene-reducing activity in anabaena cylindrica, anabaenopsis circularis, rhodospirillum rubrum, and azotobacter vinelandii. rates of acetylene reduction showed a gradual increase and reached a peak after 2 to 6 h of continuous incubation under acetylene. thereafter, enzyme activity rapidly declined. a similar enhancement of ethylene production was observed when pretreatment with acetylene was interrupted ... | 1977 | 413480 |
| [metabolism of carotenoids during dark and photooxidative degradation in anabaena variabilis]. | changes of carotenoids were studied in the cells of the blue-green alga anabaena variabilis incubated in dark for a long period of time in a phosphate buffer, and also upon photooxidative degradation of the "dark" culture, i. e. a culture that had been grown for 8 days and incubated in the darkness for a certain period of time. incubation in the dark resulted in the formation and accumulation in the cells of two new pigments, xanthophyll-450 and beta,beta-carotene-4,4'-dione, whose content decre ... | 1977 | 414056 |