Publications

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 ...	1979	108514
[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 ...	1979	107975
from extracellular to intracellular: the establishment of mitochondria and chloroplasts.	paracoccus and rhodopseudomonas are unusual among bacteria in having a majority of the biochemical features of mitochondria; blue-green algae have many of the features of chloroplasts. the theory of serial endosymbiosis proposes that a primitive eukaryote successively took up bacteria and blue-green algae to yield mitochondria and chloroplasts respectively. possible characteristics of transitional forms are indicated both by the primitive amoeba, pelomyxa, which lacks mitochondria but contains a ...	1979	36620
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 ...	1979	398767
the pattern of sporulation in anabaena circinalis and comments on the role of heterocysts in sporulation in blue-green algae.	cells between two intercalary heterocysts differentiate at random into spores in a. circinalis. one or more cells, which fail to transform into spores, are present between the two adjacent spores, and these cells disorganize later. a critical c:n ratio regulates sporulation and heterocyst formation. during sporulation the reductive ability of the heterocyst gradually diminishes. it is concluded on the basis of this and other evidence that sporulation is regulated by interactions between heterocy ...	1978	97869
hydrogen metabolism in blue-green algae.	this manuscript reviews the literature on hydrogen metabolism in blue-green algae and reports some new data from this laboratory. h2-formation by intact cells is found to be catalyzed exclusively by nitrogenase. its rate appears to be variable from strain to strain used byt is--in our hands--very small. therefore, blue-green algae are presumably of limited value in projects of solar energy conversion to form molecular hydrogen. these organisms are also able to consume the gas in a reaction catal ...	1978	96876
[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 ...	1978	107639
excitation energy transfer between pigment system ii units in blue-green algae.	efficiency in excitation energy transfer from closed to open reaction center ii in blue-green and red algae was estimated by the method developed by joliot and joliot (c.r. acad. sci. (1964) 258, 4622--4625) after slight modification; the number of open reaction centers ii was counted from the mean o2 yield of repetitive short flashes. the efficiency in energy transfer in chlorella pyrenoidosa was the same in our measurement as that reported by joliot and joliot (0.55 +/- 0.02). however, the val ...	1978	102343
immunological relationship between phycoerythrins from various blue-green algae.		1978	100412
[electron microscopic data on the mesosomelike and myelinlike structures of blue-green algae].	the mesosome-like structures of blue-green algae were studied by freeze-etching without preliminary fixation and, in parallel, by a technique of ultrathin sections. these structures were found mainly in synechococcus elongatus and synechocystis aquatilis, less often, in anacystis nidulans and anabaena variabilis, and were not detected in plectonema boryanum. the following types of membrane structures were encountered: (1) formation consisting of three- and five-layered membranes and resembling t ...	1978	212674
[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 ...	1978	207361
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 ...	1978	214181
characterization of hydrogenases from blue--green algae [proceedings].		1978	105955
[production of vitamin b 12 by a blue-green alga].	in this study, we have been able to demonstrate the production and liberation of vitamin b12 (up to 16.5 pg/ml after 31 days of growth) by a blue green alga. anabaena flos-aquae, in non-axenic and axenic cultures. this finding has a relevant ecological significance since it shows that, like bacteria, blue green algae may play a role as producers of vitamin b12.	1978	106945
application of a new bioassay to screen the toxicity of polychlorinated biphenyls on blue-green algae.		1978	107989
tolerance of aureofungin and streptocycline by n-fixing blue-green algae.		1978	109422
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 ...	1978	110567
pesticide (hexachlorocyclohexane) inhibition of growth and nitrogen fixation in blue-green algae anabaenopsis raciborskii and anabaena aphanizomenoides.	the effects of the pesticide hexachlorocyclohexane (hch) on the nitrogen fixing blue-green algae anabaenopsis raciborskii and anabaena aphanizomenoides commonly found as blooms in fish ponds were studied. these algae were very sensitive to hch, and a distinct decrease in growth rate was observed on prolonged incubation. lower concentrations (10 microgram/ml) were algistatic and higher concentrations (60 microgram/ml) were algicidal. the inhibition of nitrogen fixation indicated that the presence ...	1978	80890
extracellular release of organic products and growth of bacteria in anabaena cylindrica (blue-green alga) culture.	the studies were made with stationary cultures of anabaena cylindrica (blue-green alga). the bacterial microflora accompanying blue-green algae is subject to succession and elimination in the course of growth. the bacteria are able to utilize organic products released by the blue-green algae. the products released by a. cylindrica to the environment are peptide-like compounds.	1978	81602
biosynthesis of delta-aminolevulinic acid by blue-green algae (cyanobacteria).	when levulinic acid, a competitive inhibitor of delta-aminolevulinic acid dehydratase, was added to growing cultures of blue-green algae (cyanobacteria), delta-aminolevulinic acid was excreted into the medium and cell growth was inhibited.	1978	97274
the blue-green algae in nuclear power plant cooling water.	a study was undertaken to determine the effects of passage through the cooling system of the zion nuclear plant, illinois, u.s.a., on the blue-green algae present in lake water. the blue-green algae were isolated by means of membrane filtration, enumerated and identified to genera. as a result of cooling system passage there was a definite reduction in the numbers of blue-green algae. this reduction appeared to be due to mechanical, as well as elevated temperature, damage. a few genera showed on ...	1978	97496
effects of mosquito control insecticides on nitrogen fixation and growth of blue-green algae in natural plankton associations.		1978	98184
microtubules and microfilaments as major components of a phagocytic apparatus: the cytopharyngeal basket of the ciliate pseudomicrothorax dubius.	the cytopharyngeal basket of pseudomicrothorax dubius, through which filamentous blue-green algae are ingested, consists of 22 (+/- 3) nemadesmata and nemadesmal lamellae, in the form of a tube. a cytostome, delimited by the cell membrane and surrounded by 22 (+/- 3) major and minor cortical corrugations, covers the end of the basket where the latter is attached to the cell cortex. each nemadesm, at its greatest diameter, consists of about 200 microtubules which are joined together by sheet-like ...	1978	102557
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 ...	1978	104450
effect of rifampicin (3-(4-methylpiperazinyl-iminomethyl)rifamycin) on heterocyst differentiation in the blue-green algae anabaena and calothrix.	chains of multiple heterocysts form in anabaena und calothrix filaments on treatment with rifampicin. the multiple heterocysts form irrespective of whether the rifampicin treatment is given in combined nitrogen-free or supplemented medium. this suggests the possibility of involvement of a species of rna or of protein as intracellular heterocyst inhibitor and indicates that some latent pattern-determining mechanism may operate in the combined nitrogen medium.	1978	104451
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.	1978	414684
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 ...	1978	416753
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 ...	1978	646357
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 ...	1978	415361
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 ...	1978	418740
blue-green algal inhibition of diatom growth: transition from mesotrophic to eutrophic community structure.	cell-free filtrates of axenic or bacterized cultures of the dominant blue-green algae from a freshwater lake inhibited the growth of diatoms isolated from the same lake. lake waters, collected during blue-green algal blooms, also inhibited diatom growth. in situ observations over a 5-year period indicate that diatom bloom populations vary inversely with the levels of the preceding blue-green algal populations. blue-green algal dominance of eutrophic lakes is attributed to this allelopathy, and d ...	1978	17752367
effects of no. 2 fuel oil, nigerian crude oil, and used crankcase oil on attached algal communities: acute and chronic toxicity of water-soluble constituents.	water extracts of a no. 2 fuel oil, a nigerian crude oil, and used crankcase oil were examined for their effects on algal communities in experiments lasting several weeks conducted under near-natural conditions. no. 2 fuel oil extracts depressed algal biomass (chlorophyll a) and resulted in blue-green algal (cyanobacterial) dominance and decreased diatom occurrence. changes in concentrations of chlorophyll c, which was specific for diatoms in this work, and phycocyanin, which was specific for bl ...	1978	16345329
nitrogen fixation (acetylene reduction) by epiphytes of freshwater macrophytes.	the involvement of epiphytic microorganisms in nitrogen fixation was investigated in a shallow freshwater pond near ithaca, n.y. the acetylene reduction technique was used to follow diel and seasonal cycles of nitrogen fixation by epiphytes of myriophyllum spicatum. acetylene-reducing activity was maximal between noon and 6 p.m., but substantial levels of activity relative to daytime rates continued through the night. experiments with the seasonal course of activity showed a gradual decline duri ...	1978	16345301
effect of temperature on blue-green algae (cyanobacteria) in lake mendota.	the temperature optimum for photosynthesis of natural populations of blue-green algae (cyanobacteria) from lake mendota was determined during the period of june to november 1976. in the spring, when temperatures ranged from 0 to 20 degrees c, there were insignificant amounts of blue-green algae in the lake (less than 1% of the biomass). during the summer and fall, when the dominant phytoplankton was blue-green algae, the optimum temperature for photosynthesis was usually between 20 and 30 degree ...	1978	16345318
diurnal variation in n(2) fixation and photosynthesis by aquatic blue-green algae.	rates of (14)co(2) fixation, o(2) evolution, and n(2) fixation (acetylene reduction) by natural populations of blue-green algae recovered from lake mendota were measured at frequent intervals between sunrise and sunset. photosynthesis and n(2) fixation were depressed during midday when light intensity was greatest. as the light intensity rose, most of the algal population migrated to deeper, light-limited waters where radiation damage would be diminished. as the relative rate of n(2) fixation co ...	1977	16659792
uptake and utilization of sugar phosphates by anabaena flos-aquae.	the effect of various sugar phosphates on co(2) fixation in anabaena flos-aquae was investigated and found to be very similar to that found for isolated spinach chloroplasts. one exception, glucose 6-phosphate, has a stimulatory effect on co(2) fixation in anabaena but not in isolated chloroplasts.further examination of the role of glucose 6-phosphate metabolism in anabaena indicates that: (a) this sugar phosphate can be taken up; (b) its uptake is greater in the light than the dark; (c) turnove ...	1977	16660103
allelopathic influence on blue-green bloom sequence in a eutrophic lake.	the bloom sequence in a eutrophic lake, linsley pond, over a period of 3 years is correlated to the effects of cell-free filtrates of dominant blue-green algae on both their successors and their predecessors. there is unbroken correspondence between the effects of heat-labile probiotic and antibiotic filtrates and the rise and fall of bloom populations in situ. all organisms in vitro were axenic or unialgal (bacterized) isolates from linsley pond.	1977	17821808
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.	1977	611431
accumulation of aldrin and dieldrin by blue-green algae and related effects on photosynthetic pigments.		1977	405060
muramic acid as a measure of microbial biomass in estuarine and marine samples.	muramic acid, a component of the muramyl peptide found only in the cell walls of bacteria and blue-green algae, furnishes a measure of detrital or sedimentary procaryotic biomass. a reproducible assay involving acid hydrolysis, preparative thin-layer chromatographic purification, and colorimetric analysis of lactate released from muramic acid by alkaline hydrolysis is described. comparison of semitropical estuarine detritus, estuarine muds, and sediments from anaerobic black sea cores showed mur ...	1977	869528
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 ...	1977	202262
phosphate metabolism in blue-green algae. iii. the effect of fixation and post-staining on the morphology of polyphosphate bodies in plectonema boryanum.		1977	70323
[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 ...	1977	408585
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 ...	1977	265523
hydrogen production by nitrogen-starved cultures of anabaena cylindrica.	nitrogen-starved cultures of the alga anabaena cylindrica 629 produced hydrogen and oxygen continuously for 7 to 19 days. hydrogen production attained a maximum level after 1 to 2 days of starvation and was followed by a slow decline. the maximum rates were 30 ml of h2 evolved per liter of culture per h or 32 mul of h2 per mg of dry weight per h. in 5 to 7 days the rate of h2 evolution by the more productive cultures fell to one-half its maximum value. the addition of 10(-4) to 5 x 10(-4) m ammo ...	1977	402109
temperature dependence on the delayed fluorescence of chlorophyll a in blue-green algae.	1. the delayed fluorescence of chlorophyll a was measured with a phosphoroscope by changing the temperature in a range of room temperatures in intact cells of blue-green algae, anacystis nidulans, two strains of anabaena variabilis and plectonema boryanum, and other kinds of algae, cyanidium caldarium and chlorella pyrenoidosa. the induction of delayed fluorescence remarkably depended on the temperature of measurment. nevertheless, the induction pattern was characterized by three levels of inten ...	1977	403943
[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 ...	1977	403963
estimation of internal ph in cells of blue-green algae in the dark and under illumination.	carbonylcyanide m-chlorophenylhydrazone (cccp) or nigericin induced translocation of h+ in the dark across the cell membrane of blue-green algae plectonema boryanum and anacystis nidulans. the direction of the h+ flux depended on the ph of the suspending medium. at acidic ph, an influx of h+ and at alkaline ph an efflux of h+ were observed. it is suggested that the influx takes place at ph's higher than the "internal" ph and the efflux at ph's lower than that. the internal ph was estimated to be ...	1977	72067
penicillinase (beta-lactamase) formation by blue-green algae.	beta-lactamase (penicillinase) activity was found in a number of strains of blue-green algea. in some cases, this enzyme permitted algae to overcome the inhibitory effects of penicillin. production and localization of beta-lactamase were studied in a unicellular species, coccochloris elabens (strain 7003), and in a filamentous, nitrogen-fixing anabaena species (strain 7120). when cells were grown in a neutral medium with nano3 as n source, the ph rose during growth; at a ph of about 10, most of ...	1977	15530
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 ...	1977	410383
[toxicity of natural populations of several blue-green algae].		1977	411017
[several methods of isolation and purification of toxic substances from blue-green algae].		1977	411018
fine structure of wall bodies in large cells of an anabaena species.	a new type of inclusion in blue-green algae termed a wall body is described. these are elongate bodies of medium electron density, from 6 to 70 nm in thickness and at least 0.2 micrometer in depth found in large cells of anabaena sp. b387. the bodies are up to 12 micrometer long, extending the complete length of the cell in some cases. some of the bodies are bifurcated and the ends appeared to come in contact with the plasma membrane. the wall bodies lie at various angles in the cells. up to six ...	1977	205391
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 ...	1977	418760
role of phycobilin pigments in photosynthesis.	experimental data on possible role of phicobilliprotein (phbp) in photosynthesis are analysed. it is concluded that the widely spread notion about phbp only as the light-gathering pigments which transfer the energy to chlorophyll, turned to be insufficiently substantiated experimentally until recently. at the same time the discovered ability of phbp for reversible redox transformations together with the new data on the nature of fluorescence of blue-green algae and phbp localization in the cell ...	1977	19089
[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 ...	1977	404512
physical properties of blue-green algae: ultracentrifugation and electron microscope studies.		1977	410073
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 ...	1977	411095
hydrogen formation by marine blue-green algae.		1977	411686
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.	1977	413540
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 ...	1977	404280
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 ...	1976	814875
influence of sewage discharge on nitrogen fixation and nitrogen flux from coral reefs in kaneohe bay, hawaii.	nitrogen fixation was investigated in kaneohe bay, oahu, hawaii, a subtropical eutrophic estuary, by using the acetylene reduction technique on algal samples. no active, planktonic, n2-fixing blue-green algae or bacteria were observed. however, calothrix and nostoc capable of fixing n2 were cultured from navigational buoys and dead coral heads. nitrogen fixation associated with these structures was greater in the middle sector than in the south and north sectors of the estuary. experiments demon ...	1976	7198
[amino acid content in some blue-green algae of moldavia].		1976	133734
some thermodynamic and kinetic properties of the primary photochemical reactants in a complex from a green photosynthetic bacterium.	we have examined the bacteriochlorophyll reaction-center complex of chlorobium limicola f. thiosulfatophilum, strain tassajara. our results indicate that the midpoint potential of the primary electron donor bacteriochlorophyll of the reaction center is +250 mv at ph 6.8, while that of cytochrome c-553 is +165 mv. there are two cytochrome c-553 hemes per reaction center, and the light-induced oxidation of each is biphasic (t1/2 of less than 5 mus and approximately 50 mus). we belive that this ind ...	1976	2322
effect of nadp on light-induced cytochrome changes in membrane fragments from a blue-green alga.	the effect of nadp+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragements prepared from the blue-green algae nostoc muscorum (strain 7119) that had high rates of electron transport from water to nadp+ and from an artificial electron donor, reduced dichlorophenolindophenol (dciph2) to ndap+. the membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. with dciph2 as the elec ...	1976	2320
presence of two subunit types in ribulose-1,5-bisphosphate carboxylase from blue-green algae.		1976	3179
observations on the feeding mechanism, diet and digestive physiology of histriobdella homari van beneden 1858: an aberrant polychaete symbiotic with north american and european lobsters.	1. the aberrant annelid histriobdella homari (polychaeta:eunicida) lives in the branchial chambers of the marine lobsters homarus americanus and h. vulgaris where it feeds on the rich microflora of bacteria, blue-green algae and related organisms which grow on the inner surface of the branchial chamber, the setae fringing the edges of the carapace, the gill filaments and, especially, the surfaces and setae of the epipodite plates between the gills. h. homari, therefore, is to be regarded as an e ...	1976	1016663
ion metabolism in a halophilic blue-green alga, aphanothece halophytica.	the intracellular ion content of the halophilic blue-green alga, aphanthece halophytica was studied as a function of age, external sodium and external potassium concentration. intracellular na+ was found to be about 0.38 millimoles/g dry mass. intracellular k+ concentrations were as high as 1 m and varied directly with external salinity. intracellular ca++ and mg++ were in the range previously reported for fresh water blue-green algae despite their extremely high extracellular concentrations. av ...	1976	828029
reliability of elements and systems in enzymology.	the applications of the elements of reliability to the description of the stability and aging processes of enzymes and polyenzyme systems have been considered. the inactivation of individual enzymes or polyenzyme systems whose activity varies on the molecular level according to the "all-or-nothing" principle is described by an exponential reliability law. systems of enzymes which are inactivated according to an exponential law have been considered. it has been shown that in the case of enzymes f ...	1976	1023047
comment of egami's concept of the evolution of nitrate respiration.	recent results suggest that the presence of common nitrogen salts (sodium nitrite and nitrate) in the irradiation medium can markedly protect filamentous blue green algae from potentially lethal ultraviolet light irradiation. our results as well as general biologica-l arguments as presented by egami (above) support and extend egami's original view that anaerobic respiratory pathways using nitrite and nitrate as terminal electron acceptors evolved prior to oxygen requiring aerobic respiratory pat ...	1976	823508
factors influencing dark nitrogen fixation in a blue-green alga.	nitrogen-fixing activity declines first rapidly and then more gradually when anabaenopsis circularis is transferred from light into dark conditions. the rate and duration of dark acetylene reduction (nitrogen fixation) depend upon conditions prevailing during the preceding light period. factors (such as light intensity, co2 concentration, and supply of glucose), which in the light affect photosynthesis and the accumulation of reserve carbon, have a profound effect on dark nitrogen fixation. gluc ...	1976	820251
speculations on a possible essential function of the gelatinous sheath of blue-green algae.	voluminous and often fluffy sheaths surrounding blue-green algal cells are observed (a) in productive natural waters, (b) in bacteria-containing laboratory cultures growing in inorganic nutrient media with added bacteria-assimilable organic matter, and (c) in axenic cultures in the same inorganic media even without added organic matter. the sheaths of bacteria-associated species in inorganic media without added organic matter are, by comparison, thin, and growth is meager. repeated observations ...	1976	822932
[blue-green algae aquatic flower (nocularia) in the baltic sea in august, 1974].		1976	823723
[characteristics of surface structures of unicellular blue-green algae, revealed by electron microscopic cryofractography].		1976	827429
[ultrastructure of spirulina in comparison with oscillatoria].	the following filamentous blue-green algae: s. platensis, s. platensis f. minor and s. princeps were observed under electronmicroscope and were compared with two species of the related genera oscillatoria: o. rubescens and o. chalybea. from our research it was resulted that spirulina is characterized by a more dense cellular content and by a more wide thylakoid system. the protoplasm shows various types of inclusions: polyglucan granules, lipid droplets, eyanophycin granules, polyhedral bodies, ...	1976	827871
isolation and characterization of a cyanophage infecting the unicellular blue-green algae a. nidulans and s. cedrorum.		1976	821247
phylogenetic origin of the chloroplast.	the 16s ribosomal rna of the chloroplast of euglena gracilis strain z has been characterized in terms of its 2-dimensional electrophoretic "fingerprint" (t1 ribonuclease). over 100 spots were resolved on the "fingerprint" and each spot was characterized as to which rna oligonucleotide fragment(s) is contained. when compared to similar analyses of prokaryotic 16s rrnas and eukaryotic cytoplasmic 18s rrnas, the chloroplast 16s rrna was a typically prokaryotic rna, but bore little if any relationsh ...	1976	818370
[a genetic transfer system in a cyanophyte of the genus aphanocapsa].	the possibility of a genetic transfer, through a process of transformation, has been shown in a unicellular, facultative chemoheterotroph blue-green algae, aphanocapsa 6714. similarly to the process described with anacystis nidulans, the recipient strain becomes competent when the growth reaches its second, slower, exponential phase. the genetic marker conferring resistance to p-f-phenylalanine has been transferred with a frequency 20 to 100 times higher than that of the spontaneous mutations. t ...	1976	817846
[biologically active metabolites of blue-green algae and their effect on experimental animals].		1976	817985
functional 70s hybrid ribosomes from blue-green algae and bacteria.	hybrid 70s ribosomes were produced by combing anacystis nidulans and escherichia coli 30s and 50s subunits. both the a. nidulans 30se. coli 50s and e. coli 30s- a. nidulans 50s hybrids were functional in synthesizing protein when tested in a standard in vitro amino acid incorporating system. both 70s hybrids were inhibited by streptomycin but the degree of inhibition was dependent upon the source of the 30s subunit. the ability to form functional 70s ribosomes from subunits of blue-green algae a ...	1976	822798
viability of lyophilized cyanobacteria (blue-green algae).	lyophilizatin of 13 cyanobacterial cultures belonging to seven genera was attempted in a variety of suspending substances. all organisms survived lyophilization when suspended in lamb serum. some of the organisms could be successfully lyophilized in horse serum, beef serum, fetal bovine serum, or human ascites fluid. with the exception of nostoc muscorium, none of the organisms survived lyophilization in skim milk medium, egg albumin medium, or jansen salts medium.	1976	827240
[study of the hydrolysis process in blue-green algae using a mathematical experimental design method].		1976	820947
conversion of acetylene reduction rates to nitrogen fixation rates in natural populations of blue-green algae.		1976	822744
blue-green algae: their excretion of iron-selective chelators enables them to dominate other algae.	during blue-green algal blooms, other algae can be completely suppressed. this ability of blue-green algae to suppress other algae may be determined by the abailability of iron. iron deprivation induces the production of hydroxamate chelators, which appear to be the agent suppressing other algae.	1976	818707
ribonucleotide reductase in blue-green algae: dependence on adenosylcobalamin.	ten species of freshwater blue-green algae exhibit an adenosylcobalamin-dependent ribonucleotide reductase, thuse explaining the requirement for cobalt by these organisms. the evidence suggests a phylogenetic affinity between the cyanophytes and bacteria, such as clostridium and rhizobium, and the euglenoid flagellates, which also use the cofactor-dependent reductase. in contrast, the ribonucleotide reductase reaction in the few green algae surveyed shows no dependence on cobalamins.	1976	818711
partial sequences of 16s rrna and the phylogeny of blue-green algae and chloroplasts.		1976	819841
cyanobacterial dna-binding protein related to escherichia coli hu.	a dna-binding protein has been isolated from two cyanobacteria (blue-green algae): anabaena sp and aphanocapsa sp. it has a molecular weight as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis of about 10,000, is rich in lysine and arginine, and lacks tyrosine, tryptophan, and cysteine. the proteins from both strains show immunological identity with a similar dna-binding protein from escherichia coli, when tested by immunodiffusion with an antiserum prepared against the e. ...	1976	819928
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, ...	1976	812868
endolithic blue-green algae in the dry valleys: primary producers in the antarctic desert ecosystem.	endolithic unicellular blue-green algae occur under the surface of orthoquartzite rocks in the dry valleys of southern victoria land, antarctica. this report of primary producers in the antarctic desert ecosystem suggests that, in future efforts to detect life in extraterrestrial (for example, martian) environments, scientists should consider the possible existence of endolithic life forms.	1976	17837022
fossil microorganisms from the approximately 2800 to 2500 million-year-old bulawayan stromatolite: application of ultramicrochemical analyses.	microfossils, probably representing members of precambrian photosynthetic communities of bacteria and blue-green algae, have been found in the approximately 2800-2500 million-year-old bulawayan stromatolites from rhodesia. several populations of coccoid and elongate microfossils have been observed in the dark, carbon-rich stromatolite laminae. some of these elongate forms are morphologically similar to modern bacterial spores. these microfossils were studied in petrographic thin sections and ide ...	1976	16592348
metabolism of delta-aminolevulinic acid in red and blue-green algae.	delta-aminolevulinic acid was incorporated in vivo into c-phycocyanin and b-phycoerythrin in two species of the rhodophyta (cyanidium caldarium, porphyridium cruentum) and three species of the cyanophyta (anacystis nidulans, plectonema boryanum, phormidium luridum). amino acid analysis of phycocyanin-(14)c from c. caldarium cells which had been incubated with delta-aminolevulinate-4-(14)c showed that 84% of the radioactivity incorporated was present in the phycocyanobilin chromophore and less th ...	1975	16659103
biochemical effects of technetium-99-pertechnetate on microorganisms.	the biochemical effects of technetium-99 as pertechnetate (tco(4) (-)) were investigated in a variety of microorganisms (a nonsulfur purple bacterium, five blue-green algae, a protozoan, a diatom, two heterotrophic bacteria, a red alga and two green algae). sensitivity to pertechnetate as measured by growth ranged from marked inhibition at 1 mug tc/ml (nonsulfur purple bacterium) to no effect at 600 mug tc ml (both green algae). no correlation between organism type and growth susceptibility to p ...	1975	16659059
regulation of glucose 6-phosphate dehydrogenase in blue-green algae.	glucose 6-phosphate dehydrogenase (ec 1.1.1.49) has been partially purified from anacystis nidulans and anabaena flos-aquae by means of ammonium sulfate fractionation and exclusion gel chromatography and the kinetic properties determined.glucose 6-phosphate dehydrogenase from these blue-green algae exhibits michaelis-menten kinetics at ph 6.7. at this ph, km values of 0.37 mm for glucose 6-phosphate and 10 mum for nadp were determined. at a ph above 7.4, the enzyme exhibits sigmoidal kinetics wi ...	1975	16659143
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 ...	1975	808187
formation of one-dimensional patterns by stochastic processes and by filamentous blue-green algae.		1975	810378
[detection of the blue-green algae virus with octahedral type of symmetry].		1975	813091
[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 ...	1975	813782
evolutionary information involved in primary structures of chloroplast-type ferredoxins.	the complete amino acid sequence of a chloroplast-type ferredoxin from a fresh water prokaryote, aphanothece sacrum, was determined. the sequence consisted of 96 amino acid residues and was homologous to those of ferredoxins of higher plants. comparison of eight ferredoxins, including one from a green alga and three from blue-green algae, suggested that the sequences of algal ferredoxins were as different from one another as from those of higher plants. the relationship between the numbers of di ...	1975	818076
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 ...	1975	808179