Publications

TitleAbstractYear
Filter
PMID
Filter
effect of nadp on light-induced cytochrome changes in membrane fragments from a blue-green alga.the effect of nadp+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragements prepared from the blue-green algae nostoc muscorum (strain 7119) that had high rates of electron transport from water to nadp+ and from an artificial electron donor, reduced dichlorophenolindophenol (dciph2) to ndap+. the membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. with dciph2 as the elec ...19762320
some thermodynamic and kinetic properties of the primary photochemical reactants in a complex from a green photosynthetic bacterium.we have examined the bacteriochlorophyll reaction-center complex of chlorobium limicola f. thiosulfatophilum, strain tassajara. our results indicate that the midpoint potential of the primary electron donor bacteriochlorophyll of the reaction center is +250 mv at ph 6.8, while that of cytochrome c-553 is +165 mv. there are two cytochrome c-553 hemes per reaction center, and the light-induced oxidation of each is biphasic (t1/2 of less than 5 mus and approximately 50 mus). we belive that this ind ...19762322
presence of two subunit types in ribulose-1,5-bisphosphate carboxylase from blue-green algae. 19763179
influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in kaneohe bay, hawaii.nitrogen fixation was investigated in kaneohe bay, oahu, hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. no active, planktonic, n2-fixing blue-green algae or bacteria were observed. however, calothrix and nostoc capable of fixing n2 were cultured from navigational buoys and dead coral heads. nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. experiments demon ...19767198
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 ...197715530
role of phycobilin pigments in photosynthesis.experimental data on possible role of phicobilliprotein (phbp) in photosynthesis are analysed. it is concluded that the widely spread notion about phbp only as the light-gathering pigments which transfer the energy to chlorophyll, turned to be insufficiently substantiated experimentally until recently. at the same time the discovered ability of phbp for reversible redox transformations together with the new data on the nature of fluorescence of blue-green algae and phbp localization in the cell ...197719089
[characteristics of the proteins of unicellular organisms as potential components of ecological life-support systems].a comparative characterization of the biological value of proteins from green and blue-green algae, bacteria, and microbial coenosis of straw mineralizing active sludge is given with respect to the fractional composition of total protein, its amino acid composition, and affinity for proteolytic enzymes in vitro. the above microorganisms have an adequate amino acid composition, a high content of essential amino acids, and differ in their content of readily soluble proteins. the presence of protei ...197936502
from extracellular to intracellular: the establishment of mitochondria and chloroplasts.paracoccus and rhodopseudomonas are unusual among bacteria in having a majority of the biochemical features of mitochondria; blue-green algae have many of the features of chloroplasts. the theory of serial endosymbiosis proposes that a primitive eukaryote successively took up bacteria and blue-green algae to yield mitochondria and chloroplasts respectively. possible characteristics of transitional forms are indicated both by the primitive amoeba, pelomyxa, which lacks mitochondria but contains a ...197936620
phosphate metabolism in blue-green algae. iii. the effect of fixation and post-staining on the morphology of polyphosphate bodies in plectonema boryanum. 197770323
estimation of internal ph in cells of blue-green algae in the dark and under illumination.carbonylcyanide m-chlorophenylhydrazone (cccp) or nigericin induced translocation of h+ in the dark across the cell membrane of blue-green algae plectonema boryanum and anacystis nidulans. the direction of the h+ flux depended on the ph of the suspending medium. at acidic ph, an influx of h+ and at alkaline ph an efflux of h+ were observed. it is suggested that the influx takes place at ph's higher than the "internal" ph and the efflux at ph's lower than that. the internal ph was estimated to be ...197772067
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 ...197880890
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.197881602
hydrogen metabolism in blue-green algae.this manuscript reviews the literature on hydrogen metabolism in blue-green algae and reports some new data from this laboratory. h2-formation by intact cells is found to be catalyzed exclusively by nitrogenase. its rate appears to be variable from strain to strain used byt is--in our hands--very small. therefore, blue-green algae are presumably of limited value in projects of solar energy conversion to form molecular hydrogen. these organisms are also able to consume the gas in a reaction catal ...197896876
biosynthesis of delta-aminolevulinic acid by blue-green algae (cyanobacteria).when levulinic acid, a competitive inhibitor of delta-aminolevulinic acid dehydratase, was added to growing cultures of blue-green algae (cyanobacteria), delta-aminolevulinic acid was excreted into the medium and cell growth was inhibited.197897274
the blue-green algae in nuclear power plant cooling water.a study was undertaken to determine the effects of passage through the cooling system of the zion nuclear plant, illinois, u.s.a., on the blue-green algae present in lake water. the blue-green algae were isolated by means of membrane filtration, enumerated and identified to genera. as a result of cooling system passage there was a definite reduction in the numbers of blue-green algae. this reduction appeared to be due to mechanical, as well as elevated temperature, damage. a few genera showed on ...197897496
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 ...197897869
effects of mosquito control insecticides on nitrogen fixation and growth of blue-green algae in natural plankton associations. 197898184
immunological relationship between phycoerythrins from various blue-green algae. 1978100412
excitation energy transfer between pigment system ii units in blue-green algae.efficiency in excitation energy transfer from closed to open reaction center ii in blue-green and red algae was estimated by the method developed by joliot and joliot (c.r. acad. sci. (1964) 258, 4622--4625) after slight modification; the number of open reaction centers ii was counted from the mean o2 yield of repetitive short flashes. the efficiency in energy transfer in chlorella pyrenoidosa was the same in our measurement as that reported by joliot and joliot (0.55 +/- 0.02). however, the val ...1978102343
microtubules and microfilaments as major components of a phagocytic apparatus: the cytopharyngeal basket of the ciliate pseudomicrothorax dubius.the cytopharyngeal basket of pseudomicrothorax dubius, through which filamentous blue-green algae are ingested, consists of 22 (+/- 3) nemadesmata and nemadesmal lamellae, in the form of a tube. a cytostome, delimited by the cell membrane and surrounded by 22 (+/- 3) major and minor cortical corrugations, covers the end of the basket where the latter is attached to the cell cortex. each nemadesm, at its greatest diameter, consists of about 200 microtubules which are joined together by sheet-like ...1978102557
effects of some inorganic elements on nitrogen-fixation in blue-green algae and some ecological aspects of pollution.nitrogen-fixation by two species of nostoc, one of them a lichen phycobiont, was generally stimulated by low concentrations of arsenic, cadmium, nickel, lead, palladium, and zinc. higher concentrations (0.025 to 0.125 ppm) of arsenic, nickel, and palladium were also stimulatory; however, higher concentrations of cadmium, lead, and zinc tended to inhibit fixation. with the exception of palladium and zinc at low concentrations these six tested elements tended to inhibit nitrogen-fixation in chloro ...1978104450
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.1978104451
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 ...1979104734
characterization of hydrogenases from blue--green algae [proceedings]. 1978105955
[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 b12.1978106945
[amino acid composition and transaminase activity in fish tissues, in a medium containing cyanophyceae].the content of free amino acids, activity of aspartate and alanine transaminase, number of sulphydryl groups in fish tissues were studied as affected by lethal amounts (3.2 g/l) of blue-green algae. blue-green algae have a certain affect on fishes not only by excreting biologically active substances in the process of vital activity and decay but also changing the gas regime of the medium (the oxygen content lowers, the amount of carbon dioxide increases). under the algae effect the total content ...1978107639
studies on allergenic algae of delhi area: botanical aspects.to study distribution of algae in and around delhi aerobiological surveys were undertaken for two consecutive years (september, 1972, to august, 1974). the surveys were accomplished by (a) slide exposure method and (b) culture plate exposure method. a total of 850 slides were exposed using durham's gravity sampling device. of these, 560 slides were exposed during 1973 (272 slides at two meter and 288 at ten meter height) and the rest (290 slides) were exposed during 1974 at ten meter height. a t ...1979107835
[some physico-chemical properties of the compact chromosome of ananbaena variabilis].it was shown that total dna of the blue-green algae a. variabilis can be isolated as a compact particle with the sedimentation constant of 2700--2900s by lysis of the cells with the tritonx-100--sodium deoxycholate mixture in 1.0 m nacl. the structure isolated is sensitive to ribonuclease and the hydrodynamic shift. it was found that within a compact chromosome a. variabilis dna is circular and negatively superhelicized. the density of superturns of the dna in 0,2 m nacl at 20 degrees c is 0,061 ...1979107975
application of a new bioassay to screen the toxicity of polychlorinated biphenyls on blue-green algae. 1978107989
histidine sensitive variant of the blue-green alga nostoc muscorum: response to corepressors of histidine biosynthesis.a model has been proposed to account for growth inhibition by l-histidine in a variant strain of nostoc muscorum. this strain has been characterized for its response to 3-amino-1,2,4-triazole and 1,2,4-triazole-3-alanine known to act as false core-pressors of the histidine biosynthesis genes. the histidine sensitive strain retained its sensitivity to triazole alanine while the inhibitory effects of aminotriazole were much reduced indicating a change in regulation of his genes. the probable inter ...1979108514
sulfide inhibition of photosystem ii in cyanobacteria (blue-green algae) and tobacco chloroplasts.the present study shows that in the presence of 600 nm light, sulfide acts as a specific inhibitor of photosynthetic electron transport between water and photosystem ii in the cyanobacteria aphanothece halophytica and synechococcus 6311 as well as in tobacco chloroplasts. in the presence of 600 nm light sulfied affects the fast fluorescence transients as does a low concentration (10 mm) of hydroxylamine; the fluorescence yield decreases in the presence of either chemical and can be restored by t ...1979109120
tolerance of aureofungin and streptocycline by n-fixing blue-green algae. 1978109422
resonance raman spectroscopy of chlorophyll-protein complexes.resonance raman spectra of chlorophyll a (chl a) and of chl b were selectively obtained, at low temperature, from chlorophyll-protein complexes prepared from green and blue-green algae and from higher plants. antenna chl a in the chl a-p700-protein complexes (cp i) and in the light-harvesting chl a/b-protein complexes (cp ii gives resonance raman spectra extremely close in all their features to those previously obtained from intact cells and chloroplasts. in particular, the same multiplicity of ...1978110567
spectra of cells in flow cytometry using a vidicon detector.a tv type vidicon detector was interfaced to a flow cytometer (fcm) to obtain spectra of fluorophores in cells during flow. the normal operations of the fcm are undisturbed. a spectrograph spreads 320 nm of the fluorophore fluorescence emission across the 500 channels of the detector. spectra of fluorescamine (a surface labeling agent) and of propidium iodide (a nuclear stain) were obtained from balb 3t3 cells, and the chlorophyll and phycobilin peaks were resolved from flowing blue-green algae ...1979110874
the electrophoretic isolation and partial characterization of three chlorophyll-protein complexes from blue-green algae.three chlorophyll-protein complexes have been resolved from blue-green algae using an improved procedure for membrane solubilization and electrophoretic fractionation. one complex has a red absorbance maximum of 676 nm and a molecular weight equivalency of 255 000 +/- 15 000. a second complex has an absorbance maximum of 676 nm, a molecular weight equivalency of 118 000 +/- 8000, and resembles the previously described p-700-chlorophyll a-protein (cpi) of higher plants and algae. the third chloro ...1979111710
[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 ...1979111718
herbicidins c and e, two new necleoside antibiotics.streptomyces saganonensis no. 4075 used for production of herbicidins a and b has also produced other two antibiotics, herbicidins c and e in submerged culture. isolation of the antibiotics was performed by adsorption on resinous adsorbent followed by elution with aqueous meoh and completed by silica-gel chromatography. physico-chemical characteriation revealed that herbicidins c and e are new nucleoside antibiotics having an adenine moiety in their structures. herbicidins c and e indicated inhi ...1979117003
[extracellular metabolites and the satellite bacteria of blue-green algae]. 1979117285
[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
influence of pesticides on the growth of cyanobacteria.two unicellular and two filamentous cyanobacteria (blue-green algae) were exposed under conditions optimal for photoautotrophic growth to eleven pesticides. low concentrations (0.01 to 5 ppm) of diuron, atrazine, and paraquat inhibited growth. with mcpa, mcpp, 2,4-d, milstem and ethrel, marked inhibitory effects were achieved only at concentrations above 100 ppm. growth was inhibited by glyphosate, ddt, and thiram at intermediate concentrations. in some cases, the effective concentration of the ...1979120640
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.1979121000
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 ...1979121545
[amino acid content in some blue-green algae of moldavia]. 1976133734
[skin lesions caused by contact with blue-green algae]. 1979156475
[reduction paths of reaction centers of photosystem i of photosynthesis].the behaviour of esr signal i in blue-green algae and chloroplasts is considered under various illumination and with various previous treatment. it is shown that the main process determining the kinetics of p700 plus reduction is the reaction with reduced components of the electron transfer chain between the two photosystems. if the accumulation of the products is inhibited by any way, then the reduction rate depends on the reactions with reducing agents in the incubation medium accumulated unde ...1975167869
midpoint redox potentials of plant and algal ferredoxins.midpoint potentials of plant-type ferredoxins from a range of sources were measured by redox titrations combined with electron-paramagnetic-resonance spectroscopy. for ferredoxins from higher plants, green algae and most red algae, the midpoint potentials (at ph 8.0) were between --390 and --425 mv. values for the major ferredoxin fractions from blue-green algae were less negative (between --325 and --390 mv). in addition, spirulina maxima and nostoc strain mac contain second minor ferredoxin co ...1977202262
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 ...1977205391
[redox potentials of some metalloproteins].the standard redox potentials of soluble cytochromes c isolated from the green alga chlorella and the blue-green algae spirulina and aphanezomenon were determined by potentiometric titration and found to be equal to +380 mb, +330 mb and +357 ab, respectively. the standard redox potentials of plastocyanin preparations from pisum sativum and atriplex leaves were also determined and found close to those of soluble cytochromes c, i. e. +395 mb and +375 mb, respectively. the metalloproteins studied w ...1978207361
[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 ...1978212674
distribution of adenosine 5'-triphosphate (atp)-dependent hexose kinases in microorganisms.a systematic study of adenosine triphosphate (atp)-dependent hexose kinases among microorganisms has been undertaken. sixteen hexose kinases of five major types were partially purified from 12 microorganisms and characterized with respect to specificity for sugar and nucleotide substrates and michaelis constants for the sugar substrates. glucokinase activities that phosphorylate glucose and glucosamine are inhibited by n-acetyl-glucosamine and xylose, were found to be present in the non-sulphur ...1978214181
glutamate synthase in blue-green algae. 1975236957
fructose-diphosphate aldolase from blue-green algae. 1975237181
identification of chlorophyll b in extracts of prokaryotic algae by fluorescence spectroscopy.solvent extracts of three different prokaryotic algae from three species of didemnid ascidians contained pigments identified, on the basis of their fluorescence excitation (e)and fluorescence emission (f)spectral maxima (measured in nm) at 77k, as chlorophyll a (e 449, f 678) and chlorophyll b (e 478, f 658). the release of algae on cutting or freezing diplosoma virens was accompanied by a strong unidentified acid that converted these pigments to pheophytins. this unexpected finding provided fur ...1977265523
pathways of assimilatory sulphate reduction in plants and microorganisms.assimilatory sulphate reduction, largely restricted to plants and microorganisms where it provides reduced sulphur for the formation of amino acids and proteins, nucleic acids, and various sulphur-containing coenzymes, begins with the activation of sulphate through reaction with atp to form adenosine 5'-phosphosulphate (aps) and adenosine 3'-phosphate 5'-phosphosulphate (paps). two pathways of assimilatory sulphate reduction are known. one, found in some blue-green algae (cyanobacteria) and in a ...1979398767
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 ...1977402109
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 ...1977403943
[effect of metalloproteins on the photochemical activity of chloroplasts treated with polyene antibiotics].the effects of various metall-containing proteins (plastocyanin, plantacyanin, azurine and cytochromes of the f type) on the activity of photosystem i of chloroplasts, treated with polyene antibiotics, were studied. the inhibiting effect of the polyenes, surgumycin and philipin, was completely removed by an addition of copper-containing protein plastocyanin. no similar effect was exerted by other cu-containing proteins--azurine and plantacyanin. the cytochromes of the f type isolated from the gr ...1977403963
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
[amino acid composition of polynucleotide-peptide complexes isolated from algae].the amino acid composition of the peptide moiety of sulphur containing polynucleotide-peptide complexes (s-pnpc) was studied with four species of green algae and two species of blue-green algae. s-pnpc contained almost all amino acids which were usually encountered in acid hydrolysates of proteins, and also unidentified ninhydrin-positive compounds. the amino acid composition of the peptide moiety of s-pnpc was rather similar in the case of different algae, and was characterized by the prevailen ...1977404512
accumulation of aldrin and dieldrin by blue-green algae and related effects on photosynthetic pigments. 1977405060
[structure and cell division of the blue-green alga plectonema boryanum].our data on the structure of the blue-green alga plectonema boryanum, as well as the analysis of the data of other authors, show that its cells resemble bacterial cells in the basic features of their fine structure (the cell wall, cytoplasmic membrane, nucleoid, membraneous formations, ribosomal apparatus). besides the organelles typical of blue-green algae, organelles similar to mesosomes and formations looking like lysosomes were found in pl. boryanum. data obtained in the course of the format ...1977408585
physical properties of blue-green algae: ultracentrifugation and electron microscope studies. 1977410073
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
[toxicity of natural populations of several blue-green algae]. 1977411017
[several methods of isolation and purification of toxic substances from blue-green algae]. 1977411018
the colonial rock-forming microfossils of the bohemian upper proterozoic (czechoslovakia), 'bohemipora pragensis' n.g., n.sp.large amounts of well preserved microfossils have been reported from the cherts of the upper proterozoic of the bohemian massif (middle europe). they resemble those described by cayeux (1894) from the upper proterozoic (brioverian) of bretagne (france). it is shown, unlike the views of cayeux and his followers (deflandre, 1955, and graindor 1957), that the observed structures did not belong to individuals but to colonies of filamentous prokaryotic organisms, most probably blue-green algae (cyano ...1977411095
hydrogen formation by marine blue-green algae. 1977411686
identification of a non-magnetic iron centre and an iron-storage or -transport material in blue--green algal membranes by mössbauer spectroscopy.at least two species of iron were identified in crude membrane preparations of the blue-green algae chlorogloea fritschii and anacystis nidulans by mössbauer spectroscopy. one species was non-magnetic with chemical shift more characteristic of a ferredoxin-like centre than of any known low-spin fe(ii) biological compounds. studies on cells grown under depleted-iron conditions show the other iron species to be part of the system for iron metabolic transport and/or storage.1977413540
hydrogen metabolism in the facultative anoxygenic cyanobacteria (blue-green algae) oscillatoria limnetica and aphanothece halophytica.two facultative anoxygenic photoautotrophic cyanobacteria, oscillatoria limnetica and aphanothece halophytica were found capable of co2 photoassimilation using molecular hydrogen as electron donor in a photosystem i driven reaction. a. halophytica was also capable of evolving hydrogen from na-dithionite reduced methylviologen in a light independent reaction.1978414684
anilines: selective toxicity to blue-green algae.the blue-green alga agmenellum quadruplicatum (strain pr6) was very sensitive to aniline and p-toluidine (potential environmental toxicants) in an algal lawn assay (the growth of the algal lawn was inhibited with as little as 1 microgram of p-toluidine per disk). assays with seven other species of blue-green algae showed that they had varying sensitivities ranging from 1 to 100 micrograms of p-toluidine. under comparable conditions, 0.5 milligram or more of p-toluidine was needed to inhibit a gr ...1978415361
changes in photosynthetic rate and pigment content of blue-green algae in lake mendota.blue-green algal blooms were present in lake mendota (dane county, wis.) from june to november 1976. concentrations of total algal biomass and of particular algal species were monitored and compared with the pigment contents (chlorophyll a and phycocyanin) and photosynthetic rate of the algal populations. the specific photosynthetic rate (micrograms of c fixed per microgram of chlorophyll a per hour) was a good measure of the physiological state of the algae because this quantity increased just ...1978416753
isolation and properties of fungi that lyse blue-green algae.of 70 pure microbial cultures isolated from aquatic habitats, soil, and air according to the ability to lyse live blue-green algae, 62 were fungi representing the genera acremonium, emericellopsis, and verticillium. algal-lysing fungi were isolated from all habitat types sampled. the remaining isolates comprised four bacteria and four streptomycetes. all isolates lysed anabaena flos-aquae and, in most cases, several other filamentous and unicellular blue-green algae. the fungi generally showed g ...1978418740
sheep mortalities associated with the blue green alga nodularia spumigena.in 2 field mortalities studied, sheep died and showed haemorrhage and diffuse liver necrosis after drinking water from dams containing growths of the blue green algae nodularia. sheep dosed with water containing n. spumigena mert 5, 9 and 18 days after collection from one of the farm dams developed pyrexia and leucopenia before death. at necropsy, these sheep showed extensive haemorrhage, accumulations of yellow fluid in body cavitis and acute hepatic necrosis. guinea pigs dosed with the water 9 ...1977418760
archean photoautotrophy: some alternatives and limits.from the archean geological record, one can infer that photoautotrophy evolved early in earth history; however the nature of this photosynthesis -- whether it was predominately or cyanobacterial -- is less clearly understood. general agreement tht the earth's atmosphere did not become oxygen rich before the early proterozoic era places constraints on theories concerning more ancient biotas. accommodating this limitation in various ways, different workers have hypothesized (1) that blue-green alg ...1979503457
thermal pollution consequences of the implementation of the president's energy message on increased coal utilization.the thermal consequences of coal utilization are most meaningfully assessed in comparison with the form of power generation replaced by coal which is most likely nuclear. the different effects are influenced by siting decisions and the intrinsic thermal efficiencies of the two fuel systems. nuclear power plants discharge 50% more waste rheat to the atmosphere through cooling towers or to a water body than coal-fired plants. coal-fired plants require about 2/3 as much water as nuclear power plant ...1979540623
porphyrins and phycobilins in precambrian rocks.samples of precambrian rocks (1.7-2.6 billion years, u.s.s.r.) contain metalloporphyrins and linear tetrapyrrole pigment similar to phycobilin 655 from modern blue-green algae microystis (according to data of phosphorescence spectroscopy). the detection of ancient phycobilin makes it possible to relate the data on pigment paleobiochemistry with the evolution of photosynthetic system.1977611431
effects of low concentrations of bisulfite-sulfite and nitrite on microorganisms.a wide range of microorganisms was tested to determine their sensitivity to low concentrations of bisulfite-sulfite and nitrite, solubility products of so2 and no2, respectively. photosynthesis by blue-green algae (cyanobacteria) was more strongly inhibited by 0.1 mm bisulfite-sulfite and 1 mm nitrite at ph 6.0 than photosynthesis by eucaryotic algae and respiration of bacteria, fungi, and protozoa. at ph 7.7, blue-green algae were still more sensitive to bisulfite-sulfite and nitrite than eucar ...1978646357
evolution of 5srna.the evolution of 5srna of 17 organisms ranging from human to bacteria has been studied using a sequence homology analysis. the evolutionary rate of 5srna genes has been estimated to be 2.2x10(-10) replacement per one nucleotide site per year. this value is about the same as that of cytochrome c or trna's (congruent to 2x10(-10)). a phylogenic tree of these organisms including both eukaryotes and prokaryotes has been constructed from the evolutionary distances (the rate of nucleotide substitution ...1975765486
control of gene expression in blue-green algae. 1975803643
nitrogen fixation and the heterocyst in blue-green algae. 1975805725
nucleic acid synthesis and regulation in blue-green algae. 1975805726
phylogenetic origin of the chloroplast and prokaryotic nature of its ribosomal rna.the 16s ribosomal rna of the euglena gracilis chloroplast has been characterized in terms of its two-dimensional electrophoretic "fingerprint" (t1 ribonuclease). results show it to be a typically prokaryotic 16 s rrna. by the present criterion, different chloroplasts are shown to be related to one another and at least distantly to blue-green algae and perhaps to bacillaceae. these results argue in favor of an endosymbiont origin of the chloroplast.1975806081
photoreactivation of uv-irradiated blue-green algae and algal virus lpp-1.ultraviolet (uv) sensitivity and photoreactivation of blue-green algae cylindrospermum sp., plectonema boryanum, spores of fischerella muscicola and algal virus (cyanophage) lpp-1 were studied. the survival value after uv irradiation of filaments of cylindrospermum sp. and virus lpp-1 showed exponential trend and these were comparatively sensitive towards uv than f.muscicola and p.boryanum. photoreactivation of uv-induced damage occurred in black, blue, green, yellow, red and white light in cyli ...1975807175
structures of biogenic origin from early precambrian rocks of euro-asia.spheroidal microfossils mainly 20 to 100 mug in diameter and exhibiting granular surface textures have been recovered from early precambrian rocks by applying a new method of water separation in combination with thin chemical preparation. in contrast to the acritarcha, these microfossils are characterized by a relatively low specific weight (close to one) and considerable fragility due to impregnation by mineral matter. they occur in archean sediments of hindustan, in rocks of the baltic and ald ...1975807898
effect of pesticides on blue-green algae and nitrogen-fixation.the effects of the pesticides, amitrol, a derivative of amitrol (viz. 3,5-diamino-1,2,4-triazole), diquat, paraquat, linuron, mcpa, malathion, and monuron, were studied on the nitrogen-fixing algae, anabaena cylindrica, aulosira sp., calothrix elenkenii. chlorogloeae frischii, cylindrospermum muscicola, nostoc sp. from collema tenax, nostoc muscorum tolypothrix tenuis, and westiellopsis sp. in general, two types of response were discernible; an initial period of depression succeeded by an increa ...1975808179
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
x-ray induced inactivation of the capacity for photosynthetic oxygen evolution and nitrate reduction in blue-green algae. 1975808826
[decomposition of simazine herbicide in algal cultures].the possibility of simazine accumulation and detoxication in the cultures of some species of green, yellow-green, and blue-green algae was investigated. it has been shown that the algae can accumulate simazine in amounts hundred times exceeding its concentration in the cultural medium. the protein fraction contained up to 28.8% of simazine accumulated by the algae. the accumulation of water-soluble products of simazine metabolism in the cultural medium is indicative of the partial transformation ...1975809645
the heterocysts of blue-green algae (myxophyceae). 1975810188
formation of one-dimensional patterns by stochastic processes and by filamentous blue-green algae. 1975810378
molecular mechanisms for dna repair in the blue-green algae. 1975811209
report on a biochemical red tide repressive agent.organisms were isolated from the november 1973 red tide outbreak in a search for a naturally occurring predator organism. two organisms were found which look promising as a means of biocontrol: a tintinnideae spp., ciliate and gomphosphaeria aponina kutzing, a blue-green algae. this report characterizes a blue-green algal toxin found to be lethal to the florida red tide organism gymnodinium breve davis.1975812692
carbon dioxide assimilation in blue-green algae: initial studies on the structure of ribulose 1,5-bisphosphate carboxylase.d-ribulose 1,5-bisphosphate carboxylase was purified from the blue-green alga anabaena cylindrica (lemm) by procedures involving acid precipitation, ammonium sulfate fractionation, and sephadex g-200 gel filtration. the enzyme was homogeneous by the criterion of polyacrylamide disc gel electrophoresis and was a multimer of a single-size polypeptide chain of 54,000 daltons. the carboxylases from four species of blue-green algae (anabaena, nostoc strain mac, agmenellum quadruplicatum strain pr-6, ...1976812868
photosynthetically-linked oxidation of diaminobenzidine in blue-green algae. 1975813016
[detection of the blue-green algae virus with octahedral type of symmetry]. 1975813091
[comparison of histone-like proteins from blue-green algae with ribosomal basic proteins of alga and wheat germ histones].histone-like proteins was found in blue-green alga anacystis nidulans, which has no nucleus. f2b2, f2a2, f2a1 fractions were found in histone-like algae proteins and no fraction f1. content of basic amino acids (arginine being prevailing in algae protein) is quite identical in histone-like algae proteins and in wheat germs histones, while the content of acid amino acids is considerably higher in algae. the presence in procaryotic cells of basic proteins similar in a number of properties to histo ...1975813782
[problems of toxin formation in blue-green algae]. 1975814388
[cultivation of candida tropicalis k-41 on blue-green algae hydrolysates]. 1975814391
halophilic-blue-green algae.the isolation of a halophilic blue-green alga, aphanothece halophytica, from great salt lake is described. the organism was cultured from waters with salinities up to saturated nac1 (about 30% w/v). it has an optimum salinity for growth of about 16% nac1, but can grow very slowly even in saturated nac1. based on the study of the great salt lake organism, and on a review of the earlier literature, it is concluded that despite recent reports to the contrary, true halophilic blue-green algae do exi ...1976814875
letter: toxicity to livestock of the blue-green algae anabaena circinalis. 1975816341
Displaying items 1 - 100 of 908