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the effect of inhibitors on the electron flow triggering photo-phobic reactions in cyanophyceae.1. since photo-phobic reactions in the blue green alga phormidium uncinatum seem to be triggered by changes of electron flow rates into or out of an electron pool situated in the electron transport chain between photo-system ii and i, the effect of inhibitors affecting the electron transport chain has been studied. 2. dose response curves of the phobic reaction have been measured by varying the trap energy in double beam light trap experiments with constant pairs of monochromatic light. from the ...1975808185
requirement of low oxidation-reduction potential for photosynthesis in a blue-green alga (phormidium sp.).photosynthesis in a phormidium species which forms dense conical-shaped structures in thermal springs is strongly inhibited by aeration but is stimulated by sulfide and other agents (cysteine, thioglycolate, sulfite) which lower the oxidation-reduction potential. the compact structures which this alga forms in nature may restrict oxygen penetration from the enviroment so that the anaerobic or microaerophilic conditions necessary ofr photosynthesis can develop. the alga may be defective in a re ...1975808187
stoichiometric association of extrinsic cytochrome c550 and 12 kda protein with a highly purified oxygen-evolving photosystem ii core complex from synechococcus vulcanus.a highly purified, native photosystem ii (ps ii) core complex was isolated from thylakoids of synechococcus vulcanus, a thermophilic cyanobacterium by lauryldimethylamine n-oxide (ldao) and dodecyl beta-d-maltoside solubilization. this native ps ii core complex contained, in addition to the proteins that have been well characterized in the core complex previously purified by ldao and triton x-100, two more extrinsic proteins with apparent molecular weights of 17 and 12 kda. these two proteins we ...19921314738
occurrence of a photosystem ii polypeptide in non-photosynthetic membranes of cyanobacteria.cytoplasmic and thylakoid membranes have been purified from the cyanobacteria anacystis nidulans r2 and phormidium laminosum by sucrose density gradient centrifugation. probing of western blots of proteins from these purified membrane fractions with antibodies directed against the 33 kda polypeptide of photosystem ii from pea indicates that this protein is present in both the thylakoid and cytoplasmic membranes, rather than just the thylakoid membranes. this has been confirmed by immunogold labe ...19921630319
carotenoid composition in the cyanobacterium phormidium laminosum. effect of nitrogen starvation.when pigments of the non-n2-fixing cyanobacterium phormidium laminosum were carefully extracted and analyzed in a completely o2-free atmosphere, by either high performance liquid chromatography (hplc) or thin layer chromatography (tlc), the presence of only two carotenoids (namely, beta-carotene and nostoxanthin) was detected. however, exposure of pigments to an air atmosphere during their manipulation led to the rapid appearance in the organic extracts of at least three additional carotenoids ( ...19911903716
modulation of fibroblast motility by a cytosolic extract of cyanobacteria.proliferation and migratory behavior of l929 murine fibroblasts were shown to be modified in the presence of a cytosolic extract of phormidium sp. (cyanobacteria). the addition of phormidium extract to the growth medium (dulbecco's modified eagle's medium) supplemented with 0.5% newborn calf serum increased cell proliferation. the effect was shown to be cell line specific. a quantitative analysis performed according to de laat, tertoolen, and bluemink (1981, eur. j. cell biol., 23, 273-279), sho ...19911910290
further evidence for the electron pool hypothesis. the effect of kcn and dspd on the photophobic reaction in the filamentous blue-green alga phormidium uncinatum.in continuation of experiments with photo-system ii inhibitors [3-(3,4-dichlorophenyl)-1,1-dimethylurea and 2,5-dibromo-3-methyl-6-isopropylbenzo-quinone] the effect of photosystem i inhibitors was studied. 1. neither the plastocyanin inhibitor, potassium cyanide, nor the ferredoxin antagonist, disalicyliden propandiamin, markedly affected those phobic reactions which are mediated by the electron transport via photosystem ii into the electron pool. 2. on the other hand those phobic reactions, wh ...1976828026
allophycocyanin from the filamentous cyanophyte, phormidium luridum.allophycocyanin from the filamentous cyanophyte, phormidium luridum, was purified by ammonium sulfate fractionation and ion exchange chromatography on brushite columns. the specific absorption coefficient (e 0.1% 1cm) of purified allophycocyanin was 6.1 in distilled water and 7.3 in 0.05 m potassium phosphate buffer (ph 7). absorption maxima of allophycocyanin occurred at 650, 618 (shoulder), 350, and 275 nm. circular dichroic spectra displayed positive ellipticity bands at 655 and 625 nm, and a ...1975809053
antialgal substances for iodine-disinfected swimming pools.forty substances were tested for antialgal activity against chlorella pyrenoidosa (wis. 2005) and phormidium inundatum (wis. 1093). c. pyrenoidosa exhibited greater resistance to adverse effects of test compounds than did p. inundatum. although several structurally unrelated compounds were inhibitory to both alga species, even at an initial concentration of 1.0 mg/liter, methylthio-s-triazines, ametryne, prometryne, and terbutryne, at 0.1 mg/liter, restricted growth to less than 25% of control ( ...1977596878
ordered arrays of the photosystem i reaction centre after reconstitution: projections and surface reliefs of the complex at 2 nm resolution.we present an electron microscopical analysis of the photosystem i reaction centre, the membrane complex involved in the second light-driven step of photosynthetic electron transfer in plants and cyanobacteria. to this end, ordered two-dimensional arrays were reconstituted from detergent solubilized photosystem i reaction centres and phospholipids, and studied by electron microscopy and digital image processing. small (p1) and large (p3) hexagonal lattices obtained with reaction centres of the t ...19902120036
influence of electric fields on photophobic reactions in blue-green algae.the effect of external electric fields on photo-accumulations of phormidium uncinatum in light traps has been studied. 1. in direct current fields the phobic reaction of trichoms leaving the light field is not impaired if a voltage of 2.5 v is not exceeded. with voltages between 3 and 7 v the trichoms are motile, but phobic reactions are cancelled, provided the organisms are oriented more or less parallel to the electric field lines. higher voltages cause the algae to die within minutes. 2. only ...1977410383
isolation and characterization of lipopolysaccharides from cell walls of blue-green algae of the genus phormidium.lipopolysaccharide (lps) fractions were isolated from three species of blue-green algae of the genus phormidium, namely, p. africanum, p. laminosum, and p. uncinatum, by using a phenol-water procedure followed by exhaustive extraction with ammonium oxalate. the materials obtained were shown to be closely related biochemically. nearly 60% of the lps consisted of the polysaccharides galactose, glucose, mannose, xylose, arabinose, and rhamnose and an unidentified, fast-moving sugar residue. in addi ...1977404280
the photochemical and fluorescence properties of whole cells, spheroplasts and spheroplast particles from the blue-green alga phormidium luridum.the photochemical activities and fluorescence properties of cells, spheroplasts and spheroplast particles from the blue-green alga phormidium luridum were compared. the photochemical activities were measured in a whole range of wavelengths and expressed as quantum yield spectra (quantum yield vs. wavelength). the following reactions were measured. photosynthesis (o2 evolution) in whole cells; hill reaction (o2 evolution) with fe(cn)63- and nadp as electron acceptors (photosystem ii and photosyst ...1977402150
the epr spectrum of iron--sulphur centre b in photosystem 1 of phormidium laminosum. 1979228979
purification and primary structure of cytochrome f from the cyanobacterium, plectonema boryanum.the amino acid sequence of the soluble c-type cytochrome, cytochrome f, from the cyanobacterium plectonema boryanum (also called phormidium luridum or schizothrix calcicola) has been determined. the proposed sequence consists of one polypeptide chain of 85 residues and has three asn-gly linkages. partly due to the presence of these asn-gly bonds, which readily undergo rearrangement, proteolytic digestion on the small amount of protein available was unsatisfactory. the structure was determined pa ...1977199428
glutamine synthetase from a cyanobacterium, phormidium lapideum: purification, characterization, and comparison with other cyanobacterial enzymes.glutamine synthetase has been purified to homogeneity from cell extracts of a non-n2-fixing filamentous cyanobacterium, phormidium lapideum. the subunit molecular weight of the enzyme was determined as about 59,000 by sodium dodecyl sulfate gel electrophoresis. electron micrographs of the phormidium enzyme revealed a two-layered structure of regular hexagons (12 subunits per molecule), which markedly resembles the three-dimensional polypeptide backbone structure of the salmonella typhimurium glu ...19882907514
energy transfer among the chromophores in phycocyanins measured by picosecond kinetics.energy-transfer processes in the algal light-harvesting proteins, the phycocyanins, have been studied by means of picosecond absorption spectroscopy. after excitation at 530 nm, the absorption at several wavelengths in the range 480--669 nm decayed with a short time constant (picosecond) and a long time constant (greater than 1 ns). for c-phycocyanin, energy transfer from the beta to the alpha subunits is interpreted as being a likely candidate for the short time constant; the long time constant ...1979115492
preparation of active fractions enriched in photosystem i and photosystem ii from the thermophilic blue-green alga phormidium laminosum. 1978105942
influence of cypermethrin and fenvalerate on a green alga and three cyanobacteria isolated from soil.the effects of two pyrethroid insecticides, cypermethrin and fenvalerate, on a green alga (scenedesmus bijugatus) and three species of cyanobacteria (synechococcus elongatus, nostoc linckia, and phormidium tenue), all isolated from a black cotton soil, were studied using either cell number or chlorophyll a as toxicity criterion. all the four species were either unaffected or stimulated at 5 micrograms ml-1. of the two insecticides, cypermethrin, at 10 to 50 micrograms ml-1, inhibited s. bijugatu ...19873121278
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 ...1978102342
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 ...1978102341
power transmission along biological membranes.hypothesis on long-distance power transmission along extended energy-transducing membranes (skulachev, 1969, 1971, 1980), has been experimentally proven in four different systems, namely, (i) trichomes of filamentous cyanobacterium phormidium uncinatum; (ii) filamentous mitochondria and mitochondrial network in fibroblasts; (iii) clusters of roundish heart muscle mitochondria interconnected with mitochondrial junctions; (iv) mixed animal cell cultures interconnected with gap junctions. in all ca ...19902111408
participation of two photosystems in the photo-phobotaxis of phormidium uncinatum. 19744209298
respiration in blue-green algae.the low rate of endogenous respiration exhibited by the blue-green algae anacystis nidulans and phormidium luridum was not increased by the addition of respiratory substrates. however, endogenous respiration was inhibited by low concentrations of cyanide and by high carbon monoxide tensions. in addition, the uncouplers dinitrophenol and carbonyl cyanide p-trifluoromethoxyphenylhydrazone both stimulated the respiratory rate. the transition of cells from the aerobic steady state to anaerobiosis wa ...19694390093
c-phycocyanin from phormidium luridum. isolation of subunits. 19724627355
light effect on the internal osmotic pressure of the blue-green algae plectonema boryanum and phormidium luridum. 19724629378
interactive image analysis system to determine the motility and velocity of cyanobacterial filaments.an interactive image analysis system has been developed to analyse and quantify the percentage of motile filaments and the individual linear velocities of organisms. the technique is based on the "difference" image between two digitized images taken from a time-lapse video recording 80 s apart which is overlaid on the first image. the bright lines in the difference image represent the paths along which the filaments have moved and are measured using a crosshair cursor controlled by the mouse. ev ...19911908871
photosynthetic activities of membrane preparations of the blue-green alga phormidium luridum.techniques have been developed for the isolation of whole spheroplaste and membrane preparations from the blue-green alga phormidium luridum which are active in photosystem-ii-sensitized and photosystem-i-sensitized electron-transport reactions and in photophosphorylation. attention is called to the necessity of supplying magnesium and phosphate throughout the preparative and assay procedures for obtaining active membranes. selective washing of a proper membrane preparation is shown to remove a ...1976823011
on the linkages between chromophore and protein in biliproteins, vii. amino acid sequence in the chromophore regions of c-phycoerythrin from pseudanabaena w 1173 and phormidium persicinum.bilipeptides from all chromophore regions were prepared by trypsin digestion of c-phycoerythrin from pseudanabaena w 1173 and phormidium persicinum. analytical separation and quantitative determination of bilipeptides was achieved by isoelectric focusing, preparative isolation by gel chromatography and ion-exchange chromatography. amino acid analysis revealed cysteine as the only amino acid common to all chromopeptides. amino acid sequences were determined by edman degradation and the dansyl-edm ...1978417013
the reaction specificities of the pea and a cyanobacterial thylakoid processing peptidase are similar but not identical.the thylakoid processing peptidase from the cyanobacterium phormidium laminosum has been extracted from thylakoid membranes by solubilization with triton x-100. its reaction specificity has been compared with the analogous pea peptidase by processing in vitro of radiolabelled wheat and p. laminosum thylakoid lumenal precursor polypeptides. the cyanobacterial polypeptide is processed to the mature size through an intermediate by the p. laminosum peptidase, but to a polypeptide that has a slightly ...19902121534
[immunostimulating activity of the lipopolysaccharides of blue-green algae].the whole cells of blue-gree algae and lipopolysaccharides isolated from these cells were shown to stimulate the production of macro-(mainly) and microglobulin antibodies in rabbits. the macro- and microphage indices in rabbits increased significantly after the injection of lps isolated from blue-green algae 24--48 hours before infecting the animals with a virulent y. pseudotuberculosis strain. besides, the inhibiting action of this strain on the migration of phagocytes to the site of infection ...1979117655
freeze-fracture analysis of thylakoid membranes and photosystem i and ii enriched fractions from phormidium laminosum.thylakoid membranes of the thermophilic cyanobacterium phormidium laminosum have been fractionated into photosystem ii and photosystem i particles. these fractions have been characterized by their partial electron transport activities, and biochemical and spectral properties. exoplasmic fracture face and protoplasmic fracture face particles in the unfractionated thylakoid membranes were shown to correspond in size to particles in freeze-fractured photosystem ii and photosystem i fractions, respe ...19863088002
sensitivity and resistance of a blue-green alga phormidium mucicola to streptomycin and penicillin. 19704990326
3-(3,4-dichlorophenyl)-1, 1-dimethylurea-insensitive oxygen production in a cell-free preparation from phormidium luridum that shows redox potential dependent coupling to one-electron oxidants. 19714995803
nitrogen metabolism of nostoc muscorum & phormidiu phormidium fragile. 19715004444
increase effected by calcium ion in the rate of oxygen evolution from preparations of phormidium luridum.the presence of ca2+ causes a twentyfold or greater increase in the rate of oxygen evolution by cell-free preparations of phormidium luridum. the requirement for ca2+ is specific; other divalent cations are much less effective or are inhibitory. the rate of the hill reaction is maximal at 30 mm cacl2 in both detergent-free and brij 35 preparations. the 3-(3,4-dichlorophenyl)-1,1-dimethylurea-insensitive component of oxygen-evolving activity in each preparation also shows the requirement for adde ...19761259961
[stimulation of the natural self-purification of soil].connected with the elaboration of the sanitary norm of cadmium in soil were performed examinations to appoint the self-purification index. this index is the highest permissible concentration of a noxious chemical substance in soil not yet injuring irreversible the process of natural self-purification. as criterions of the self-purification were selected normal and potential respiration, quantity of bacteria, actinomyceta, fungi, proteolytic, nitrifying, and cellulolytic micro-organisms, inhibiti ...19836422669
generation of lysoglyceroglycolipids in the cyanobacterium, phormidium tenue.two kinds of lysoglycolipids, monogalactosyl 1-monoacylglycerol and digalactosyl 1-monoacylglycerol were generated in the cyanobacterium, phormidium tenue, when it was stored at -20 degrees for more than 1 month. by comparison of the compositions of fatty acid residues between monogalactosyl 1-monoacylglycerol and monogalactosyl diacylglycerol, digalactosyl 1-monoacylglycerol and digalactosyl diacylglycerol, respectively, the 1-monoacylgalactolipids were presumed to be formed by regioselective d ...19921368418
linear dichroism of microalgae, developing thylakoids and isolated pigment-protein complexes in stretched poly(vinyl alcohol) films at 77 k.a variety of unicellular algae, thylakoids from higher plants in different stages of maturity and isolated pigment-protein complexes were oriented in stretched polyvinyl alcohol films. low temperature linear dichroism (ld) spectra of chlorella pyrenoidosa and higher plant thylakoids in the films were very similar to those obtained after orientation of similar samples using magnetic or electric fields. positive ld bands corresponding to chl a (670) and (682) and negative bands due to chl a (658) ...19806774749
protein aggregation in c-phycocyanin. studies at very low concentrations with the photoelectric scanner of the ultracentrifuge.solutions of c-phycocyanin of very low concentrations were examined by sedimentation-velocity studies in the spinco model e ultracentrifuge equipped with a photoelectric scanning system and a monochromator. at sufficiently low concentrations complete disaggregation from the hexamer to the monomer was observed. the equilibrium constant of monomer to hexamer was estimated to be approx. 10(30). for studies of aggregation over the complete range of concentration, c-phycocyanins from phormidium lurid ...19715123877
coupling membranes as energy-transmitting cables. ii. cyanobacterial trichomes.power transmission along trichomes of filamentous cyanobacteria phormidium uncinatum has been studied with the use of ethylrhodamine fluorescence as a probe for the transmembrane electric potential difference (delta psi). it is found that agents preventing the light-induced delta psi formation (photosynthetic redox chain inhibitor dibromothymoquinone) or dissipating delta psi (uncoupler tetrachlorotrifluoromethylbenzimidazole) strongly decrease the fluorescence of the ethyl-rhodamine-stained tri ...19883138245
generation and isolation of cyanobacterial inside-out thylakoid vesicles.a method has been designed to prepare inside-out thylakoid vesicles from a cyanobacterial species (phormidium laminosum). everted thylakoid vesicles could be generated by yeda press treatment after induced membrane pairing. membrane pairing was induced either by addition of high concentrations of mg2+ ions or by lowering the ph of the fragmentation media. the inside-out vesicles were isolated by aqueous polymer two-phase partition. the membrane orientation was determined by proton translocation ...19883138947
gliding motility in aphanothece halophytica: analysis of wall proteins in mot mutants.the unicellular cyanobacterium aphanothece halophytica (pcc 7418) is motile, and spontaneous nonmotile (mot) mutants accumulate when the organism is subcultured. analysis of mot mutants suggests that a glycoprotein in the cell wall is involved in the motility mechanism. proteins from the wall fraction of the wild type and five mot clones were analyzed by gradient sodium dodecyl sulfate-acrylamide gel electrophoresis. four clones were similar to the wild type, and one clone, mot-3, was missing a ...19816793555
epr characteristics of oxygen-evolving photosytem ii particles from phormidium laminosum.the epr characteristics of oxygen evolving particles prepared from phormidium laminosum are described. these particles are enriched in photosystem ii allowing epr investigation of signals which were previously small or masked by those from photosystem i in other preparations. epr signals from a signal ii species and high potential cytochrome beta-559 appear as they are photooxidised at cryogenic temperatures by photosystem ii. the signal ii species is a donor close to the photosystem ii reaction ...19816263334
electrical nature of the taxis signal in cyanobacteria.electrical events after a light-dark stimulus were studied in the multicellular organism phormidium uncinatum. normally, such a stimulus causes the gliding trichome to reverse direction. by directing a large light spot on the end of a batch of trichomes and then switching it off, we achieved synchronization of the trichomes, since the "head" is much more sensitive than the "tail." the abrupt disappearance of a uniform light produced a depolarization wave which initiated at the head, as registere ...19826801020
pami and pamii restriction endonucleases from phormidium ambiguum. 19921741304
utilization of energy stored in the form of na+ and k+ ion gradients by bacterial cells.the hypothesis that na+ and k+ gradients have an energy storing function [v. p. skulachev (1978) febs lett. 87, 171-176] has been tested in experiments with escherichia coli, the marine bacterium vibrio harveyi, an extremely halophilic halobacterium halobium and a fresh-water cyanobacterium phormidium uncinatum from lake baikal living at an extremely low salt concentration. the capability of these microorganisms to maintain delta microh was compared using motility as a delta microh-supported fun ...19836307692
studies on a toxin produced by the cyanobacterium phormidium persicinum. 19911794548
composition of the ferredoxin-nitrite reductase from the cyanobacterium phormidium laminosum. 19902125945
isolation and identification of the restriction endonuclease ptai from phormidium tadzschicicum, an isoschizomer of bspmii. 19921480496
assembly of 2-d membrane protein crystals: dynamics, crystal order, and fidelity of structure analysis by electron microscopy.membrane protein reconstitution into two-dimensional (2-d) ordered arrays is described. the assembly of 2-d crystals may be modeled as a two-step process: the membrane protein is first integrated in the lipid bilayer and then crystallized by removal of excess detergent or lipid and/or by precipitating agents. lipid-detergent, protein-detergent, and lipid-protein interactions are critical during the first step, while lipid-protein and protein-protein interactions dominate events in the second ste ...19921296757
photosynthetic electron transport in a cell-free preparation from the thermophilic blue-green alga phormidium laminosum.1. a cell-free preparation of membrane fragments was prepared from the thermophilic blue-green alga phormidium laminosum by lysozyme treatment of the cells followed by osmotic shock to lyse the spheroplasts. the membrane fragments showed high rates of photosynthetic electron transport and o2 evolution (180-250 mumol of o2/h per mg of chlorophyll a with 2,6-dimethyl-1,4-benzoquinone as electron acceptor). o2-evolution activity was stable provided that cations (e.g. 10mm-mg2+ or 100mm-na+) or glyc ...19806772163
distribution of phototrophic microbes in the flat laminated microbial mat at laguna figueroa, baja california, mexico.the microbial mat community in the saltmarsh/evaporate flat interface at laguna figueroa involved in the deposition of laminated sediments was investigated. pigment analysis, light microscopy and transmission electron microscopy were used to determine the relative abundance and distribution of phototrophic species. the community is vertically stratified into four distinct phototrophic populations. the layering could be distinguished by pigment and species composition. the two layers closest to t ...19902108737
partial characterization of six chlorophyll a-protein complexes isolated from a blue-green alga by a nondetergent method.the chlorophyll a-protein complexes of a blue-green alga, phormidium luridum, are resolved in the absence of detergent, by the combination of a sepharose 4b column and sucrose density gradient centrifugation, into six chlorophyll a-containing zones. these six complexes are termed here as f15, f25, f35, f40, f60, and f65, according to their appearance in the sucrose density gradient after centrifugation. the absorption spectra of these six isolated complexes are reported, as well as the fluoresce ...19836402982
sterols: isolation from a blue-green alga.a crystalline mixture of sterols was isolated from the filamentous blue-green alga phormidium luridum. the mixture consisted of unsaturated 24-ethylcholesterols possessing delta(7)-, delta(5,7)-, and delta(5)-bonds together with their delta(22)-derivatives and a small amount of cholesterol. the major component was 24-ethyl-delta(7)-cholestenol. squalene and phytol were also evident.19685677529
[effect of redox systems on the motility and the phototactic reactions of phormidium uncinatum]. 19685709367
[propagation of electrical potential changes in filamentous cyanobacteria].possible energy transmission along conjugating membranes was investigated. it was found by extracellular electrodes that under local illumination of blue-green algae phormidium uncinatum the electrical current propagated along trichomes. the form and sign of the responses show that e. m. f. appears in the illumination region, which generates on the cellular membrane the potential difference with a negative charge inside the cell. the initiated transmembrane potential difference propagates along ...19826803847
purification and some properties of the nitrite reductase from the cyanobacterium phormidium laminosum.assimilatory ferredoxin-nitrite reductase (ec 1.7.7.1, ammonia: ferredoxin oxidoreductase) has been purified 5300-fold with a specific activity of 625 units/mg protein from the filamentous non-heterocystous cyanobacterium phormidium laminosum. the enzyme was soluble and consisted of a single polypeptidic chain of 54 kda. it catalyzed the reduction of nitrite to ammonia using ferredoxin or flavodoxin as electron donor. methyl and benzyl viologens were also effective as electron donors but neither ...19902119228
[on the antagonism of atabrine and flavine nucleotides in the behavior of movement and reaction to light of phormidium uncinatum]. 19665992184
studies on glycolipids. iii. glyceroglycolipids from an axenically cultured cyanobacterium, phormidium tenue.seven new monogalactosyl diacylglycerols (1-7) and six new digalactosyl diacylglycerols (11-16) were isolated from an axenically cultured cyanobacterium, p. tenue. their structures were elucidated on the basis of physicochemical evidence and the results of enzymatic hydrolysis using a lipase (from rhizopus arrhizus). comparison of antialgal activity for p. tenue between monogalactosyl diacylglycerols (1-8) and digalactosyl diacylglycerols (11-19) revealed that the former showed more potent activ ...19911804541
envelope structure of four gliding filamentous cyanobacteria.the cell walls of four gliding filamentous oscillatoriaceae species comprising three different genera were studied by freeze substitution, freeze fracturing, and negative staining. in all species, the multilayered gram-negative cell wall is covered with a complex external double layer. the first layer is a tetragonal crystalline s-layer anchored on the outer membrane. the second array is formed by parallel, helically arranged surface fibrils with diameters of 8 to 12 nm. these fibrils have a ser ...19957730269
an autolytic substance in a freshwater cyanobacterium phormidium tenue.an autolytic substance in an axenic cyanobacterium, phormidium tenue, was identified as a mixture of fatty acids, by use of cultured cells in the laboratory. among them, linoleic acid and linolenic acid were potent growth inhibitors.19902112049
[analysis of the cable structure of blue-green algae].peculiarities of electrical responses under local illumination of filamentous cyanobacteria (blue-green algae). phormidium uncinatum were studied by means of extracellular electrodes. recording of electrical responses at different distances from the exposure place and comparison of these data with the results obtained on physical model of ph. uncinatum end expected response parameters computed made it possible to estimate the parameters of the cable which can serve as the object model: rc=440 c/ ...19826812650
characterization of a small cryptic plasmid, ppf1, from phormidium foveolarum and vector construction.the 1509 bp cryptic plasmid, ppf1, from phormidium foveolarum, a strain of filamentous cyanobacteria of the lpp group, was completely sequenced. the ppf1 nucleotide sequence had 97.8% overall similarity with that of a small plasmid from plectonema boryanum. the structural organization of ppf1 and vector construction are discussed.19937764277
dismutation of hydroxylamine to ammonia and nitrite by a novel, membrane-bound enzyme from the cyanobacterium phormidium uncinatum.extracts from ammonium-grown phototrophic cultures of phormidium uncinatum exhibited a catalytic and stoichiometric formation of nitrite and ammonia from hydrogen peroxide and hydroxylamine. this reaction was due to a novel enzyme (referred to as hydroxylamine dismutase), which was bound to the heavier thylakoid membranes. the enzyme was solubilized from the membranes by detergent treatment and further purified by ion-exchange chromatography. on the basis of inhibitor studies, the involvement of ...19902121280
replication of filamentous cyanobacterial plasmids, ppf1 from phormidium foveolarum and ppb1 from plectonema boryanum.single-stranded plasmid dna of ppf1 from phormidium foveolarum that was specifically degraded by s1 nuclease was detected by southern hybridization. this is also the case of the homologous plasmid ppb1 from plectonema boryanum. these observations suggest that such small cryptic plasmids as ppf1 and ppb1, both from gram-negative and filamentous cyanobacteria, replicate by a rolling circle mechanism in their living cells.19947764871
lateral transport of energy along the coupling membranes of cyanobacteria.the light-induced electric potential changes brought about local illumination of trichomes of cyanobacteria phormidium uncinatum have been studied by means of extracellular electrodes. responses of several electrodes located at various distances from the illuminated area of the trichome were monitored simultaneously. they turned out to be similar in shape: a rapid increase to the maximum value was followed by a slow decay toward a nonzero residual level. the results offer strong evidence in favo ...19826813322
properties of oxygen-evolving photosystem-ii particles from phormidium laminosum, a thermophilic blue--green alga.1. o2-evolving photosystem-ii particles from the thermophilic blue--green alga phormidium laminosum contained 1 mol of mn/13--17 mol of chlorophyll a compared with 1 mol of mn/65--75 mol of chlorophyll a in unfractionated membranes. 2. at least two-thirds of the mn in the photosystem-ii particles was removed by mild heating and by treatment with tris or edta, with concomitant loss of o2 evolution. however, irreversible inactivation was also caused by washing in buffers without mgcl2, and this in ...19816796068
kinetics of reduction of the primary donor of photosystem ii. influence of ph in various preparations.the kinetics of reduction of p-680, oxidized by a flash, have been measured with chloroplasts treated with tris, hydroxylamine or cholate, with ps-ii particles from phormidium (tris-treated) and with subchloroplast particles prepared with digitonin or triton. in all cases the electron transfer from d1 to p-680+ has similar rates, influenced similarly by ph and d1 has a one-electron capacity.19816786346
gene sequence for the 9 kda component of photosystem ii from the cyanobacterium phormidium laminosum indicates similarities between cyanobacterial and other leader sequences.a 9 kda polypeptide which is loosely attached to the inner surface of the thylakoid membrane and is important for the oxygen-evolving activity of photosystem ii in the thermophilic cyanobacterium phormidium laminosum has been purified, a partial amino acid sequence obtained and its gene cloned and sequenced. the derived amino acid sequence indicates that the 9 kda polypeptide is initially synthesised with an n-terminal leader sequence of 44 amino acids to direct it across the thylakoid membrane. ...19892501648
isolation and identification of anti-tumor-promoting principles from the fresh-water cyanobacterium phormidium tenue.bioassay-directed fractionation of the extract of the cyanobacterium p. tenue led to the isolation of the three classes of glycolipids, viz., monogalactosyl diacylglycerol (mgdg), digalactosyl diacylglycerol (dgdg), and sulfoquinovosyl diacylglycerol (sqdg) as anti-tumor-promoters. in comparing the anti-tumor-promoting effect of the three classes of glycolipids with various acyl residues, mgdg and dgdg inhibited tumor promotion more intensely than sqdg. with respect to mgdg and dgdg, the inhibit ...19938221980
characterization of photosystem ii electron acceptors in phormidium laminosum.chlorophyll a fluorescence has been used to monitor the redox state of the primary electron acceptor of photosystem ii (ps ii) in the blue-green alga phormidium laminosum during equilibrium titrations. the shape of induction curves measured in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (dcmu) have been analyzed. the induction curves were very similar in unfractionated thylakoid membranes and ps ii particles. in both, the fast (alpha) phase was sigmoidal, and was followed by a slow ...19836412632
a low potential iron-sulfur cluster bound to membranes in blue-green algae.a new low temperature epr signal at g = 1.92 was found in photoreduced membrane fractions prepared from blue-green algae, nostoc muscorum, tolypothrix tenuis, phormidium persicinum, and anabaena variabilis. the signal also appeared when the sample was chemically reduced in the dark. judging from the spectrum, the signal was probably due to the reduced form of a membrane-bound iron-sulfur cluster, tentatively designated as cluster d. the midpoint potential of cluster d was determined to be -0.27 ...19852987203
cloning and sequencing of the nitrate transport system from the thermophilic, filamentous cyanobacterium phormidium laminosum: comparative analysis with the homologous system from synechococcus sp. pcc 7942.a genomic region from the filamentous, thermophilic non-n2-fixing cyanobacterium phormidium laminosum was cloned and sequenced. it includes the nitrite reductase gene (nira) and three other genes (nrta, b and c) located downstream of nira, which are related to the nitrate transport system on the basis of a comparison with the homologous system from synechococcus sp. pcc 7942. no additional nitrate assimilation-related genes were identified in about 5 kb sequenced downstream of nrtc. all four gen ...19957647306
purification and properties of glutamine synthetase from the non-n2-fixing cyanobacterium phormidium laminosum.soluble glutamine synthetase activity (l-glutamate:ammonia ligase, adp forming, ec 6.3.1.2) was purified to electrophoretic homogeneity from the filamentous non-n2-fixing cyanobacterium phormidium laminosum (oh-1-p.cl1) by using conventional purification procedures in the absence of stabilizing ligands. the pure enzyme showed a specific activity of 152 mumol of gamma-glutamylhydroxamate formed.min-1 (transferase activity), which corresponded to 4.4 mumol of pi released.min-1 (biosynthetic activi ...19892563365
induction, isolation, and some properties of the nadph-dependent glutamate dehydrogenase from the nonheterocystous cyanobacterium phormidium laminosum.the level of the nadph-dependent glutamate dehydrogenase activity (ec 1.4.1.4) from nitrate-grown cells of the thermophilic non-n2-fixing cyanobacterium phormidium laminosum oh-1-p.cl1 could be significantly enhanced by the presence of ammonium or nitrite, as well as by l-methionine-dl-sulfoximine and other sources of organic nitrogen (l-glu, l-gln, and methylamine). the enzyme was purified more than 4,400-fold by ultracentrifugation, ion-exchange chromatography, and affinity chromatography, and ...19883139639
accumulation of arsenic in blue-green alga, phormidium sp.the behavior of a blue-green alga, phormidium sp., against inorganic arsenic dissolved in media was studied. the phormidium sp. was shown to have capabilities of endurance against a high concentration stress of arsenic and of accumulation of arsenic. studies on excretion of arsenic by the alga showed that there were two excretion modes, each of which had a characteristic rate constant and it could be attributed to two types of binding situations between arsenic and the tissues of the alga. the a ...19846149084
purification and characterization of alanine dehydrogenase from a cyanobacterium, phormidium lapideum.alanine dehydrogenase (aladh) was purified to homogeneity from cell-free extracts of a non-n2-fixing filamentous cyanobacterium, phormidium lapideum. the molecular mass of the native enzyme was 240 kda, and sds-page revealed a minimum molecular mass of 41 kda, suggesting a six-subunit structure. the nh2 terminal amino acid residues of the purified aladh revealed marked similarity with that of other aladhs. the enzyme was highly specific for l-alanine and nad+, but showed relatively low amino-acc ...19947896761
protochlorophyllide reductase in photosynthetic prokaryotes and its role in chlorophyll synthesis.1. dna sequences hybridizing with the wheat protochlorophyllide reductase gene have been detected during genomic southern blots of various cyanobacterial dna samples. no such hybridization was observed with dna from photosynthetic bacteria. 2. a fragment amplified from phormidium laminosum dna has been characterized and shown to be 73% similar to the corresponding wheat sequence. at the protein level the similarity is 91%. when used as a probe for southern blotting the phormidium dna fragment co ...19957487876
[amino acid composition of the blue-green algae phormidium uncinatum (ag) gom]. 19655865402
effects of a homoanatoxin-a-containing extract from oscillatoria formosa (cyanophyceae/cyanobacteria) on neuromuscular transmission.experimental investigations were carried out with cultured and lyophilized material of the toxigenic strain oscillatoria niva-cya 92. this organism is classified as phormidium formosum (boryex gom.) anagnet kom. aqueous extracts of the algal material, containing the bioactive secondary amine alkaloid 2-(propan-1-oxo-1-yl)-9-azabicyclo(4,2,1)non-2ene (homoanatoxin-a) in an amount of 2.57 micrograms/mg lyophilized material, were tested for acute in vivo toxicity in mice, and for toxicity on neurom ...19979278976
the dark stable tyrosine radical of photosystem 2 studied in three species using endor and epr spectroscopies.the dark stable neutral tyrosine radical yd. of photosystem 2 (ps2) has been studied using electron nuclear double-resonance (endor) and electron paramagnetic resonance (epr) spectroscopies. the proton hyperfine coupling constants of all four ring protons and both beta-methylene protons have been determined for yd. in three species covering the range of oxygenic organisms; a higher plant (spinach), an alga (chlamydomonas reinhardtii), and a cyanobacterium (phormidium laminosum). it has generally ...19948110776
purification and characterization of two restriction endonucleases isolated from phormidium inundatum.we have isolated two restriction endonucleases, pinbi and pinbii, from the cyanobacterial strain phormidium inundatum, and identified them as isoschizomers of avaiii and bspmii, respectively.19957607516
some characteristics of cytochrome f in the cyanobacterium phormidium laminosum: its sequence and charge properties in the reaction with plastocyanin.part of the petca operon was cloned and the sequence of the cytochrome f gene from the moderately thermophilic cyanobacterium phormidium laminosum determined. a partial sequence of the petc gene encoding the rieske iron-sulphur protein was also obtained. the cytochrome f gene encodes a mature protein of 385 residues and a leader sequence of 45 residues. the mature protein contains several acidic or neutral residues corresponding to basic residues in the turnip protein. some of the latter are tho ...19968856106
mechanism of an early lysis by fatty acids from axenic phormidium tenue (musty odor-producing cyanobacterium) and its growth prolongation by bacteria.we have previously demonstrated that bacteria-containing phormidium tenue, a cyanobacterium which produces musty odor 2-methylisoborneol, grew beyond 8 weeks, whereas axenic alga perished suddenly between the 3rd week and the 4th week while being cultured in the laboratory. this mechanism was investigated. it is assumed that when algal cells grow beyond a certain level, the supply of co2 becomes inadequate and results in the rapid lysis of axenic alga. at that time, inhibitory substances liberat ...19947841953
subfractional analysis of cyanobacterial membranes and isolation of plasma membranes by aqueous polymer two-phase partitioning.the present work demonstrates that partition in aqueous polymer two-phase systems offers a rapid method for separation and isolation of thylakoid, plasma, and outer membranes from cyanobacteria. pure plasma membranes from phormidium laminosum can be isolated by this method within 3 h, starting with total membranes obtained by french press treatment of the cyanobacterial cells. the isolated plasma membranes have a broad density profile, giving rise to three subpopulations. the main fraction has t ...19947519833
effective detergent/chlorophyll ratio and detergent concentration in the aqueous phase during solubilization of phormidium laminosum membranes.experiments of turbidity decrease induced by detergents were systematically performed to characterize the solubilization of phormidium laminosum membrane fragments. sds, triton x-100 and a mixture of octyl glucoside/decyl maltoside/lithium dodecyl sulfate (og/dm/lids, in a molar ratio of 4.19:2.54:1) were used. the detergent concentration in the aqueous phase (dw) and the effective detergent/chlorophyll ratio in mixed aggregates (re) were determined. both parameters increased during the solubili ...19958541292
growth of phormidium sp. in aerobic secondary piggery waste-water.the potential of a cyanobacterium phormidium sp., for the tertiary treatment of piggery waste-water chemical oxygen demand > or = 3000 mg.l-1, using an aerobically stabilized secondary effluent, was studied. batch cultures were carried out in 2-l glass reactors and in a 30-l glass-fibre carousel reactor. the nutrient removal efficiency as well as biomass production were compared in synthetic mineral medium and in different concentrations of aerobically stabilized piggery effluent. the best perfo ...19947765784
components of the protein translocation machinery in the thermophilic cyanobacterium phormidium laminosum.cyanobacteria possess cytoplasmic membranes, which are common to all eubacteria, and an additional internal network of thylakoid membranes. we have investigated the distribution of the protein translocation machinery between the two membrane systems. we have demonstrated that leader peptidase activity exists in both membrane systems, suggesting that newly synthesized protein precursors are targeted directly rather than sorted after translocation. southern blot analysis suggests that the leader p ...19938267627
isolation, sequence and expression in escherichia coli of the nitrite reductase gene from the filamentous, thermophilic cyanobacterium phormidium laminosum.the nitrite reductase (nir) gene (nira) has been isolated and sequenced from the filamentous, thermophilic non-n2-fixing cyanobacterium phormidium laminosum. putative promoter-like and shine-dalgarno sequences appear at the 5' end of the 1533 bp long nir-coding region. the deduced amino acid sequence of nir from p. laminosum corresponds to a 56 kda polypeptide, a size identical to the molecular mass previously determined for the pure enzyme, and shows a high identity with amino acid sequences fr ...19957766873
strain characterization and classification of oxyphotobacteria in clone cultures on the basis of 16s rrna sequences from the variable regions v6, v7, and v8.a major problem in development of a polyphasic taxonomy is that the identification of oxyphotobacterial strains (cyanobacteria and prochlorophytes) in culture collections may be incorrect. we have therefore developed a diagnostic system using the dna sequence polymorphism in the 16s rrna regions v6 to v8 for individual strain characterization and identification. pcr primers amplifying v6 to v8 from oxyphotobacteria in unialgal cultures were constructed. direct solid-phase or cyclic sequencing wa ...19979212409
[the isolation, purification and cloning of the psm1 plasmid from the cyanobacterium plectonema boryanum].three methods of plasmids isolation from the cells of cyanobacteria: plectonema boryanum 465, p. nostocorum 636, p. nostocorum 638, p. edaphicum 262, plectonema sp. 456, phormidium uncinatum 528, anabaena variabilis 458 and synechococcus cedrorum 750 have been approved. the method of plasmids isolation by 1 m nacl salting out was used for plasmid screening. all the strains studied contained large, above 55 kb plasmids, small plasmids (1.5 kb) were found in the cells of p. boryanum 465 and p. nos ...200010872285
auto-growth inhibitory substance from the fresh-water cyanobacterium phormidium tenue.an extract of the cyanobacterium p. tenue showed a significant inhibitory effect on its own growth. bioassay-directed fractionation has led to the identification of the auto-growth inhibitory substance as a mixture of fatty acids. unsaturated fatty acids such as linoleic and linolenic acids appear to be predominantly responsible for the auto-growth inhibitory effect.19938281581
horizontal and vertical migration patterns of phormidium corallyticum and beggiatoa spp. associated with black-band disease of coralsan in situ field study of the motility patterns exhibited by phormidium corallyticum and beggiatoa spp. in black-band disease of corals was conducted over a 5-day period. measurements were made at a spatial resolution of 50 &mgr;m to document the horizontal migration of black-band across living coral tissue, while vertical migrations within the band were documented by observation and macrophotography of the black-band surface. it was determined that horizontal migration occurred both day and nig ...19968849426
isolation and characterization of the restriction endonuclease ppei from phormidium persicinum.ppei is a type ii restriction endonuclease isolated from cyanobacterial strain phormidium persicinum. the endonuclease ppei, an isoschizomer of apai, recognizes the hexanucleotide sequence (5'-gggcc/c-3') and cleaves, after the second c, producing four nucleotide 3'-cohesive ends.19968734423
sequence of morphological alterations in blue-green algae in the course of cyanophage infection.electron microscopic studies were performed on the sequence of morphological alterations induced by the cyanophage pp-1 in the blue-green algae phormidium sp. and plectonema boryanum. the following phases of virus infection were made evident: virus adsorption onto the host cell; the presence of virus "ghosts", suggesting the penetration of viral dna into the cell and its multiplication in the nucleoplasm; invagination of thylakoids and formation of the "virogenic stroma"; virus maturation within ...19816787795
sensitivity of macrophyte-dominated freshwater microcosms to chronic levels of the herbicide linuron. i. primary producers.effects of chronic concentrations of linuron (0, 0.5, 5, 15, 50, and 150 micrograms/l) were studied in indoor, macrophyte dominated, freshwater microcosms. the concentrations were kept at a constant level for 4 weeks. this paper is the first in a series of two and summarizes the course of the linuron concentrations in time and its effects on macrophytes, periphyton, and phytoplankton. these endpoints were studied from 3 weeks before the start of the treatment until 11 weeks after the start. the ...19979352210
investigations on the presence of cyanophages in fresh and sea waters of romania.investigations on the presence of cyanophages in the fresh and sea waters of romania resulted in the isolation of 31 strains. the host range of the cyanophage isolates showed some particularities as compared with classical cyanophages types. the electron optic study of the cyanophage strains grown in phormidium sp. revealed the presence of three types of virus particles, differing as regards their tail length, with a morphology similar to that of t-odd coliphages.19816787794
cloning and sequence analysis of a signal peptidase i from the thermophilic cyanobacterium phormidium laminosum.type i signal peptidases are a widespread family of enzymes which remove the presequences from proteins translocated across cell membranes, including thylakoid and cytoplasmic membranes of cyanobacteria and thylakoid membranes of chloroplasts. we have cloned and sequenced a signal peptidase gene from the thermophilic cyanobacterium phormidium laminosum which is believed to encode an enzyme common to both membrane systems. the deduced amino acid sequence is 203 residues long and although the over ...19957865790
microcystins in slovene freshwaters (central europe)--first report.cyanobacterial blooms are frequent in the north-eastern region of slovenia, where the agricultural activities are intensive, resulting in higher water eutrophication. in a two year monitoring program we identified eighteen blooms of cyanobacteria, fifteen being hepatotoxic by intraperitoneal mouse bioassay. the approximate ld100 varied from 50-1000 mg/kg (dry cell weight/animal weight) and gross pathological signs were characteristic of cyanobacterial hepatotoxins. frequently the blooms were dom ...19979131592
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