| [study of the hydrolysis process in blue-green algae using a mathematical experimental design method]. | | 1976 | 820947 |
| nitrogen fixation in bacteria and higher plants. | | 1975 | 820962 |
| isolation and characterization of a cyanophage infecting the unicellular blue-green algae a. nidulans and s. cedrorum. | | 1976 | 821247 |
| photooxidation of cyanobacteria in natural conditions. | photodynamic effects were demonstrated and assayed under field conditions in a number of different laboratory strains and pond isolates of cyanobacteria; parameters assayed for resistance to photooxidation were viable count, turbidity of the cyanobacterial suspension, and protein and pigment contents. the effects of density, colonial structure, and internal gas vacuoles on the lethal outcome were investigated. the stability and formation of superoxide dismutase under photooxidative conditions in ... | 1976 | 821394 |
| atp pools and transientss in the blue-green alga, anabaena cylindrica. | anabaena cylindrica grown in steady state continuous culture has an extractable atp pool, measured on the basis of the luciferin-luciferase assay of 165 +/- 35 nmoles atp mg chla-1. this pool is maintained by a dynamic balance between the rate of atp synthesis and the rate of atp utilization. phosphorylating mechanisms which can maitain the pool in the short term are total photophosphorylation, cyclic photophosphorylation and oxidative phosphorylation. the alga can maintain its atp pool by switc ... | 1976 | 821448 |
| pathway of nitrogen metabolism after fixation of 13n-labeled nitrogen gas by the cyanobacterium, anabaena cylindrica. | methods have been developed for identifying the pathway of assimilation of n2-derived nitrogen. the products of fixation of 13n-labeled nitrogen gas ([13n]n2), and the distribution of 13n within glutamine, were determined after short periods of labeling (approximately 1 to 120 s) and also in pulse-chase experiments. ammonia, the amide nitrogen of glutamine, and the alpha-amino nitrogen of glutamate, in that order, were the first observed products of fixation of n2 by the cyanobacterium (blue-gre ... | 1976 | 821946 |
| thiosulphate as electron donor in the blue-green alga anacystis nidulans. | | 1976 | 822124 |
| uptake and release of some radionuclides by fresh water phytoplankton in batch culture. | | 1976 | 822154 |
| symbiotic theory of the origin of eukaryotic organelles; criteria for proof. | the purpose of a scientific theory is to unite apparently disparate observations into a coherent set of generalizations with predictive power. historical theories, which necessarily treat complex irreversible events, can never be directly tested. however they certainly can lead to predictions. the 'extreme' version of the serial endosymbiotic theory argues that three classes of eukaryotic organelles had free-living ancestors: mitochondria, basal bodies/flagella/cilia [(9 + 2) homologues] and ph ... | 1975 | 822529 |
| conversion of acetylene reduction rates to nitrogen fixation rates in natural populations of blue-green algae. | | 1976 | 822744 |
| photoregulation of biologically active macromolecules. | a broad view is given of photoregulated processes as they occur in algae, fungi, halophilic bacteria, higher plants, invertebrates, and higher animals. emphasis is on the following: the organs, tissues, and organelles that participate; the nature of the photoreceptor pigments; the light-induced structural changes that occur in the photopigments; and the way in which the photochemical events are believed to be translated into the physiological response. an attempt is made to show that there exist ... | 1976 | 822780 |
| 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 |
| autochton blue-green alga (oscillatoria sp.) with high protein content and self-aggregation properties. | | 1976 | 822900 |
| neutron diffraction studies of biological membranes and membrane components. | in this paper the methods and techniques of neutron diffraction studies of biological membranes and membrane components have been described and demonstrated. foremost among these are the methods of deuterium exchange and deuterium labeling, since they can directly provide locations of membrane components. in addition, the methods of contrast variation with h2o-d2o mixtures, swelling, direct scaling of data from deuterium-labeled structures, and magnetic orientation have provided useful informati ... | 1976 | 822920 |
| the use of cellulose products to reduce agar concentration in microbiological media. | the use of agar in media for culturing microorganisms is fundamental to microbiological investigations. shortages of agar have caused increased costs and difficulty in obtaining media. evidence is presented for the use of carboxymethylcellulose (cmc), an inert compound, in conjunction with agar to reduce the concentration of agar necessary to achieve a solid plating surface. a variety of bacteria, blue-green bacteria, fungi, and a yeast were tested for growth on cmc agar media. t-2 bacteriophage ... | 1976 | 822928 |
| nitrogen fixation in the muskeg ecosystem of the james bay lowlands, northern ontario. | the acetylene-reduction assay was used for in situ and laboratory assessment of biological nitrogen fixation in the acidic, waterlogged, muskeg ecosystem of the southern james bay area, in the region of moosonee, ontario. in situ assays and subsequent laboratory experimentation revealed that nitrogenase activity was predominately a function of the activities of heterocystic blue-green bacteria associated with surface water, with the phyllosphere of mosses, and with at least one lichen, a species ... | 1976 | 822930 |
| 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 |
| photosynthetic activities of membrane preparations of the blue-green alga phormidium luridum. | techniques have been developed for the isolation of whole spheroplaste and membrane preparations from the blue-green alga phormidium luridum which are active in photosystem-ii-sensitized and photosystem-i-sensitized electron-transport reactions and in photophosphorylation. attention is called to the necessity of supplying magnesium and phosphate throughout the preparative and assay procedures for obtaining active membranes. selective washing of a proper membrane preparation is shown to remove a ... | 1976 | 823011 |
| allophycocyanin i-a second cyanobacterial allophycocyanin? isolation, characterization and comparison with allophycocyanin ii from the same alga. | | 1976 | 823047 |
| 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 |
| [blue-green algae aquatic flower (nocularia) in the baltic sea in august, 1974]. | | 1976 | 823723 |
| [ribosomes of the blue-green alga anabaena variabilis. sedimentation, density characteristics and analysis of ribosomal rna]. | ribosomes and rrnas were isolated from cells of green-blue alga anabaena variabilis. the sedimentation properties of the ribosomes as well as density, molecular weights and nucleotide composition of rrnas were determined. the ribosomes were found to have the s20,w value equal to 67.2+/-0.4s, whereas those of the ribosome subunits were 48.6+/-0.8 and 29.5+/-1.1s. the buoyant density of the ribosomes in cscl was 1.641+/-+/-0.002 g/cm3; a calculated relative protein content was 35%. the molecular w ... | 1976 | 823982 |
| ribonucleotide reductase activity in ether-treated cells of agmenellum quadruplicatum. | ribonucleotide (cytidine 5'-diphosphate) reductase activity can be detected in situ in cells of the blue-green alga agmenellum quadruplicatum, strain pr-6, after the cells are made permeable by treatment with ether. the agmenellum reductase resembles the enzyme from escherichia coli. | 1976 | 824283 |
| heterocyst and nitrogenase development in anabaena cylindrica. | the differentiation of filaments of a continuous culture of anabaena cylindrica after removal of fixed nitrogen has been examined. rapid development of proheterocysts (4-5 h) and mature heterocysts (14 h) in an ordered sequence was observed; the development of the latter was concomitant with the onset of nitrogenase activity. commitment times of 2-3 h (proheterocyst) and 5-0 (heterocyst) were measured. evidence is presented that shows that heterocyst development, rather than any product of heter ... | 1976 | 824402 |
| [hydrogen metabolism in anabaena variabilis in the dark]. | cells and extracts of the cyanobacterium anabaena variabilis are capable of hydrogen absorption in the dark in the presence of h-acceptors with various redox potentials. preliminary adaptation of the cells to anaerobic conditions has no effect on the process. a. variabilis can also evolve hydrogen in the dark. reduced methylviologen (rmv), formiate, pyruvate, and glucose may be substrates for hydrogen evolution by the cells. the extracts evolve hydrogen in the presence of rmv, benzylviologen, az ... | 1976 | 824526 |
| growth and nitrogen fixation of mutants defective in heterocyst differentiation in the blue-green alga cylindrospermum sp. | three classes of spontaneous and n-methyl-n'-nitro-n-nitrosoguanidine (ntg)-induced mutants of the blue-green alga cylindrospermum sp. were isolated in the presence of combined nitrogen. mutants with complete loss of heterocyst differentiation formed longer filaments than the parent alga and were unable to grow in nitrogen-free medium and to fix nitrogen. the second type of mutants formed long filaments with terminal heterocysts. in the third type of mutants, paired proheterocyst differentiation ... | 1976 | 824870 |
| [production and characteristic constituents of the algae spirulina platensis and maxima]. | microscopic blue-green spirulina algae, such as have been consumed since ancient times, are algae having a very high protein content (70 p. 100 of dry matter). at present the spirulina platensis species in the kanem region in chad is gathered by primitive methods, sold in the marketplace and consumed by the local population. the spirulina maxima species exists in a seminatural state in mexico city, and an industrial pilot plant harvests and produces one ton per day. both species, sp. platensis a ... | 1975 | 824992 |
| [biological characteristics of the spirulines]. | the biological characteristics of spirulina are reported in this study. the cellular structure and photosynthetic membrane structure of spirulina (cyanoschizophyta) were viewed by electron microscopy after freeze-etching. special characteristics of the alga, its ecological behavior in natural carbonated water and its energetic behaviou in the laboratory cultures are also reported. | 1975 | 824993 |
| [consumption and nutritional contribution of the blue algae (oscillatoria platensis) among some populations of kanem (tchad)]. | two food surveys determined the areas of consumption and the ethnic groups involved as well as the way and motivations for using spirulina algae (oscillatoria platensis) in chad. more than 400 homes were visited in february (dry season) and october (end of the rainy season and period after the millet harvest). consumption is limited to a restricted proportion of the population in the kanem region. among the kanembu group (the leading consumers of spirulina), frequencies of use vary between one a ... | 1975 | 824994 |
| [food value of the spiruline algae to man]. | the acceptability of various culinary products based on the algae spirulina was tested by questionaire: formulas rich in proteins, soups, omelets, desserts. spirulina are little appreciated in france due to offensive color, smell and taste. tomato and chocolate are the most acceptable flavors. lyophilisation is preferable to atomisation, and discoloration using alcohol is preferable to the acetone method. the hydrolysate obtained, having neither the smell nor the taste of algae, is excellent. ni ... | 1975 | 824995 |
| [protein and energy value of spiruline blue algae supplemented by amino acids: digestive and metabolic utilization by the growing rat]. | protein and energy value of 6 samples of "spirulina" was studied on growing rats in 1972 and 1973. sample rl 1(spirulina platensis, originating from tchad) was grown in artifical conditions in a laboratory. others samples (spirulina maxima) were grown in the solar evaporator near mexico, washed and dried either on heated rollers (mr8, mr13) or by spraying (ma 7, ma10). sample ma10 d corresponds to sample ma10, bleached by ethanol plus acetone (baron, 1975). each spirulina sample was the only pro ... | 1975 | 824996 |
| [carbohydrates synthesized by the spirulines]. | carbohydrates roughly constitute 15 p. 100 of the dry matter of sirulina. they are extracted after complete delipidation, by successive exhaustions: first with ethanol of decreasing title, then with cold water slightly acidified by chlorhydric acid in order to drain out the calcium of the phytate; then by neutral boiling water; at last by alkaline or acidic warm solutions. after neutralization, suitable defecation and concentration, carbohydrates are either purified by a slow cristalization or h ... | 1975 | 824997 |
| [hydrocarbons of the spiruline algae: nature, metabolism of heptadecane by rats and swine]. | hydrocarbons represent about half of the insaponifiable fraction of spirulina algae (0.1 to 0.3 p. 100 of the dry alga); n-heptadecane is the major component (65 p. 100). the retention of this paraffin has been measured in animals receiving these algae as the main or partial protein source. rats fed with a diet containing 280 ppm n-heptadecane (25 p. 100 alga meal) from weaning show an accumulation of this hydrocarbon in the carcass the retention levels off after 4 months and seems related to th ... | 1975 | 824998 |
| [determination of 3, 4-benzopyrene in spiruline algae produced and treated by various procedures]. | spirulina algae grow in highly salted natural lakes. artificial cultivation in tanks with addition of carbon dioxide (natural gas, burned gases) has been studied in order to improve the biosynthesis. a possible 3, 4-benzopyrene (bap) contamination must be then considered. several bap determinations have been performed in batches of algae from bath origins, prepared following different processes (filtration, spray, cylinder drying). bap contents are very low (2 to 3 ppb) and comparable between ba ... | 1975 | 824999 |
| [determination of various toxic minerals in spiruline algae of different origins, and evaluation of long-term toxicity in the rat of a lot of spiruline algae of mexican origin]. | a detailed analytical study made on samples of spirulines algae of various origins showed that these microorganisms may present an important telluric contamination, especially demonstrated by high levels of fluorine and arsenic they contain. a long term animal experimentation has been achieved with spirula maxima, obtained from the sosa texcoco solar evaporator. a diet contained in total proteins 25 p. 100 of dried atomized algae and was given for 75 weeks to wistar rats. all along the experimen ... | 1975 | 825000 |
| [microflora of spiruline preparations]. | a study, by direct microscopic examination and cultures, shows that the microflore which accompanies the spirulines preparations, varies as the origin and the technologie treatment quality. the main species are bacillacees; then, come faecal streptococcus which are the best contaminations indicators; enterobacteries, yeasts, moulds spores, are exceptional. dry products as getting old, entail a great decrease of all the species, the anaerobies being more resistant. | 1975 | 825001 |
| [changes in the lysine of spiruline algae samples after various heat treatments]. | the spirulina algae are microorganisms which are cultivated on mexican lakes for feeding use. after drying, they contain about 52 per cent of proteins, with 4 per cent of lysine and 1, 7 per cent of methionine. in the studied samples, ph is 6, 2; they are partially autolysed and contain 4 to 18 per cent of free lysine and methionine and 6, 5 per cent of soluble carbohydrates. during heating treatments, the spiurlina lysine reacts as the same as oilcak meal lysine; it resists rather well to autoc ... | 1975 | 825002 |
| [decolorization of spirulines]. | spirulinae algae are available as a high protein content food (60 p. 100 at least) but as a very colored one. colored matters of spirulinae may be subdivided in three classes: chlorophyll-a complexes carotenoïds and xanthophylls-phycocyanin and phycoerythrin. obtaining a "decolored spirulinae meal" has been studied first at laboratory level, then at microindustrial level (20 kg). dry spirulinae decoloration with ethanol and acetone lead to a pale-yellow spirulinae meal with 80 p. 100 efficiency; ... | 1975 | 825003 |
| [incorporation of a spiruline (spirulina maxima) in swine food]. | two experiments on early weaned piglets and one experiment on sows during the first two reproductive cycles were made to determine the nutritive value of spirulina maxima algae in the pig, taken as a "nutritional model" for man. the algae were introduced into the diets of the piglets, between 12 and 42 days of age, in a proportion representing 12 p. 100 of the total proteins. this level corresponded to 12 p. 100 algae in the first age feed (up to 21 days) in replacement of skim milk, and 8 p. 10 ... | 1975 | 825004 |
| [food value of spiruline algae for growth of the broiler-type chicken]. | five trials were carried out during the growth (0-8 weeks) of the broiler type chicken. the weight increase was always depressed when spiruline algae replaced traditional protein sources (soybean meal, fish meal, ...) in a complete and well balanced diet (trials 1 and 2). the delay in growth was small and non significant for 5 p. 100 or less of spirulines in the diet. however, for the highest levels of spirulines the delay in growth was more pronounced, especially during the starting period (0-4 ... | 1975 | 825005 |
| [food value of spiruline algae for the laying hen]. | the three diets (composition in table i) were isonitrogenous (16,4 p. 100 crude protein), similar in their content of lysine and sulfur amino acids, but with different levels of spiruline algae : 0 (control); 7.5 or 15 p. 100. each diet was used for the feeding of 48 hybrid pullets of medium size during a 24-week test period (32 to 56 weeks). egg production (table ii) was slightly better (47.1 g/hen/day) with 7.5 p. 100 of spirulines, compared to the control (45.3 g/hen/day), the difference bein ... | 1975 | 825006 |
| endonucleases for apurinic sites in plants. | | 1976 | 825386 |
| the fine structure of striated microtubules and sleeve bodies in several species of anabaena. | | 1976 | 825659 |
| cyanophage analysis as a biological pollution indicator--bacterial and viral. | | 1976 | 825660 |
| protein evolution in cyanobacteria. | | 1976 | 825785 |
| simultaneous measurement of oxygen concentration and absorbance changes. | | 1976 | 826185 |
| mutation to resistance for virus n-1 in the blue-green alga nostoc muscorum. | the spontaneous and nitrosoguanidine induced n-1 virus resistant mutants of the blue-green alga nostoc muscorum were isolated with the average mutation frequency of 3.55 x 10(-5) and 6.08 x 10(-4) respectively. of the surviving colonies 8 per cent became virus sensitive,whereas out of the remaining 92 per cent 9.3 per cent showed lysogenic behaviour and 13.3 per cent showed poor or no nitrogen fixing ability. mutation to virus-resistance was independent of the presence of the virus.spontaneous h ... | 1976 | 826239 |
| amino acid sequence of the major component of nostoc muscorum ferredoxin. | the amino acid sequence of the major component of ferredoxin isolated from a blue-green alga, nostoc muscorum, grown under n2 as the sole nitrogen source has been studied. the use of a combination of sequence analyzer, carboxypeptidases, and manual edman degradations on tryptic and chymotryptic peptides of carboxymethylferredoxin has established the amino acid seuqence, which consists of 98 amino acid residues. only four cysteine residues were present, located at positions 41, 46, 49, and 79. th ... | 1976 | 826526 |
| [characteristics of different growth stages of the blue-green alga anacystis nidulans (synechococcus)]. | the rate of growth of the blue-green alga anacystis nidulans is highest during the first 5--8 days but the number of the cells increases up to 30 days when the stationary phase takes place (30--60 days). the content of chlorophyll is almost constant during the first 20 days of growth while the content of phycocyanin increases; then the content of the both pigments decreases. the rate of o2 evolution and the rate of electron transport to ferricyanide decrease exponentionally during the first 10 d ... | 1976 | 826762 |
| [metabolism and destruction of the blue-green alga anabaena variablis in the dark]. | anabaena variabilis remains viable in the dark, which is accompanied with intensive utilization of the reserve polysaccharide by the cells. the content of protein and rna increases in the cells and incomplete cellular division occurs at the beginning of the culture incubation in the dark. destruction of the intracellular protein and rna begins before all the reserve polysaccharide has been utilized. during the whole period of incubation of the alga in the dark, structural integrity of the cells ... | 1976 | 826765 |
| evolution of phix174 iii. restriction map of s13 and its alignment with that of phix174. | | 1976 | 827112 |
| 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 |
| the blue-green alga agmenellum quadruplicatum contains covalently closed dna circles. | this paper reports the first direct visualization of covalently closed, circular dna from a blue-green alga. agmenellum quadruplicatum lysates, fractionated on cscl-ethidium bromide density gradients, yield a minor band of covalently closed dna circles which we have analyzed by electron microscopy and agarose gel electrophoresis. the dna consists of a number of a discrete classes of dna circles ranging in molecular weight from 3 x 10(6) daltons to 65-80 x 10(6) daltons. the function of these cir ... | 1976 | 827332 |
| [characteristics of surface structures of unicellular blue-green algae, revealed by electron microscopic cryofractography]. | | 1976 | 827429 |
| [photodestruction of the blue-green alga anabaena variablis]. | the effect of light on the cells was studied with the obligate phototrophic blue-green alga anabaena variabilis after its incubation in the dark. incubation of the alga in the dark during two weeks was not essential for the cell reproduction systems in the light. incubation in the dark during 3-4 weeks caused damages in the systems which were however reversible and repaired in the light. longer incubation of the cells in the dark results in irreversible damages of the systems protecting them fro ... | 1976 | 827666 |
| [hydrogen production by the cyanobacterium anabaena variablis in the light]. | light of low intensity (less than or equal to 25-10(5) erg-cm(-2)-sec(-1)) stimulates hydrogen production by cell suspensions of anabaena variabilis in the presence of glucose, pyruvate or formate. the maximum rate of hydrogen production in the presence of these substrates was observed at light intensities of 650, 1400 and 2250 erg-cm(-2)-sec(-1), respectively. the rate of oxygen production by the cells increases while the rate of hydrogen evolution decreases with increase in light intensity (2. ... | 1976 | 827669 |
| the postmaturational cleavage of 23 s ribosomal rna in anacystis nidulans is inhibited by infection with cyanophage as-1. | the 23s (1.1 x 10(6) mol.wt.) rrna of anacystis nidulans undergoes postmaturational cleavage to produce 0.9 x 10(6) and 0.2 x 10(6) molecular species. we have provided evidence in double labelling experiments, in which we could distinguish between the fate of molecules synthesized before and after infection, respectively, that infection with cyanophage as-1 abruptly and completely inhibits the cleavage of 23s rrna in anacystis cells. | 1976 | 827688 |
| [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 |
| effect of some environmental factors on cyanophage as-1 development in anacystis nidulans. | the development cycle of the cyanophage as-1 was studied in the host blue-green alga, anacystis nidulans, under conditions that impair photosynthesis and under various light/dark regimes. under standard conditions of incubation the 16-h development cycle consisted of a 5-h eclipse period and an 8-h latent period. burst size was decreased by dark incubation to 2% of that observed in the light. an inhibitor of photosystem ii, 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (dcmu), reduced the burst size ... | 1976 | 828019 |
| characterization and structural properties of the major biliproteins of anabaena sp. | studies are presented of the biliproteins of anabaena sp. this filamentous cyanobacterium contains three major biliproteins. whereas two of these, c-phycocyanin and allophycocyanin, are common to all cyanobacteria, the third, phycoerythrocyanin (gammamax approximately 568 nm) has hitherto not been described and its distribution among cyanobacteria appears to be limited. anabaena variabilis and anabaena sp. 6411 allophycocyanin, c-phycocyanin, and phycoerythrocyanin were purified to homogeneity a ... | 1976 | 828020 |
| heterotrophic capacities of plectonema boryanum. | acquisition of the dark heterotrophic growth capacity on glucose in plectonema boryanum involves both adaptation and enrichment of a fast-growing genotype. the adaptation includes induction of functions involved in glucose incorporation and increase in glucose-6-phosphate dehydrogenase activity. photosynthetic products are implicated in the control of both systems. efficient energy conversion in the dark, as measured by cyanophage multiplication, correlates in time with the increase in potential ... | 1976 | 828021 |
| heterotrophic micro- and macrocultures of a nitrogen-fixing cyanobacterium. | anabaena variabilis can be cloned in the dark from fragments with one and few cells, with an efficiency of about 40%, on the nitrogen-free medium of allen and arnon solidified with 0.5% agarose and supplemented with 5 mm fructose. the organism can be grown exponentially (tau2 approximately or equal to 36 h) in fermentor cultures in the dark, fixing n2, to a density of greater than 10 g dry weight/l. | 1976 | 828022 |
| further evidence for the electron pool hypothesis. the effect of kcn and dspd on the photophobic reaction in the filamentous blue-green alga phormidium uncinatum. | in continuation of experiments with photo-system ii inhibitors [3-(3,4-dichlorophenyl)-1,1-dimethylurea and 2,5-dibromo-3-methyl-6-isopropylbenzo-quinone] the effect of photosystem i inhibitors was studied. 1. neither the plastocyanin inhibitor, potassium cyanide, nor the ferredoxin antagonist, disalicyliden propandiamin, markedly affected those phobic reactions which are mediated by the electron transport via photosystem ii into the electron pool. 2. on the other hand those phobic reactions, wh ... | 1976 | 828026 |
| the fine structure of a microplate-microtubule array, microfilaments and polyhedral body associated microtubules in several species of anabaena. | a microplate-microtubule array was observed in anabaena sp. (b-378). this structure consists of an arched plate, about 8 nm thick, and various microtubules, 12 nm in diameter and 50 nm long, arranged in rows. the microtubules project at right angles from one side of the plate into the cytoplasm or towards the plasma membrane. up to twelve microplate-microtubule arrays were observed in a single section of a cell. microfilaments, about 2.8 nm in diameter and of undetermined length, were observed i ... | 1976 | 828027 |
| 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 |
| accumulation, mobilization and turn-over of glycogen in the blue-green bacterium anacystis nidulans. | 1. accumulation of glycogen up to a constant amount per cell was observed during the postexponential phase of growth, in the presence of an excess of a utilizable carbon source. cell multiplication was reproducibly controlled by growth of the organism in a nitrogen-limiting medium under photoautotrophic conditions (presence of light, air plus co2). 2. temporary starvation, i.e. by removal of light or by the addition to an illuminated culture of dcmu, 3-(3',4'-dichlorophenyl)-1,1'-dimethylurea, a ... | 1976 | 828031 |
| enzymatic modification for improving nutritional qualities and acceptability of proteins extracted from photosynthetic microorganisms spirulina maxima and rhodopseudomonas capsulatus. | the present study attempts to improve the proteins from a blue-green alga spirulina maxima and a non-sulfur purple bacterium rhodopseudomonas capsulatus through their peptic hydrolysis followed by plastein synthesis with papain. the former enzymatic process was effective in removing some photosynthetic pigments and flavors originating in the raw materials. the latter process was successful in incorporating limited amounts of methionine, lysine, and tryptophan, and thus to synthesize plasteins wh ... | 1976 | 828668 |
| isolation, growth and nitrogen fixation of a gas vacuole-less mutant of the blue-green alga anabaena aphanizomenoides. | mutants with loss of gas vacuoles (gvl-) were isolated from a clonal population of the gas vacuole containing (gvl+) blue-green alga anabaena aphanizomenoides with a spontaneous mutation frequency of 1.7 x 10(-3) in nitrogen-free media. growth and nitrogen fixation of the mutant were slow when compared to the gvl+ parent. both the parent and mutant filaments tolerated 0.02 microgram/ml of streptomycin, and higher concentrations were lethal. the reversion of the mutant towards the parent did not ... | 1976 | 829596 |
| [preliminary experiments in purification of waste water by means of algal filters]. | | 1976 | 829658 |
| the organization of chlorophyll in the plant photosynthetic unit. | | 1976 | 830042 |
| identification of a phosphorus-containing storage granule in the cyanobacterium plectonema boryanum by electron microscope x-ray microanalysis. | transmission electron microscopy of cyanobacteria couple with x-ray microanalysis has confirmed that dense deposits within these cells are composed of phosphorous. | 1977 | 845121 |
| occurrence and nature of chromatic adaptation in cyanobacteria. | forty-four axenic strains of cyanobacteria that synthesize phycoerythrin were screened to ascertain the effect of light quality on pigment synthesis. cellular pigment compositions were determined after photoautotrophic growth with low light fluxes (7.0 x 10(2) ergs/cm2 per s) of green, red, and white light, and in the case of facultative heterotrophs, after dark growth at the expense of sugars. twelve strains did not adapt chromatically: the cells contained fixed proportions of phycoerythrin, ph ... | 1977 | 856789 |
| 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 |
| origins of the nucleate organisms. | a theory regarding the early evolution of the eukaryotes is presented. it is proposed that the eukaryotes evolved through the successive stages: amoeba, flagellate, sexual flagellate. it postulated that sexuality emerged only once. a scheme relating evolution of the whiplash and tinsel forms of the flagellum to the evolution of sexuality is presented. it is suggested that sexuality first appeared in organisms capable of producing both forms of the flagellum. the phylogeny supports the hypotheses ... | 1977 | 905503 |
| seasonal distribution of vitamin b12 in lake kinneret. | vitamin b12 is formed in lake kinneret in the hypolimnion and in the sediment. the highest value of b12 recorded in the lake water was about 100 ng/liter in november and december of 1975 at a 40-m depth. the vitamin was liberated from the hypolimnion during the turnover period. this supply of the vitamin to the photic zone was accompanied by increasing biomass of dinoflagellates, bacillariophyta, and chlorophyta. the decrease in the vitamin concentration, followed by an increase, is correlated w ... | 1977 | 907339 |
| 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 |
| 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 |
| on the prokaryotic nature of red algal chloroplasts. | the sequences of oligonucleotides released by t1 ribonuclease digestion of 32-p-labeled 16s (chloroplast) and 18s (cytoplasmic) ribosomal rnas from a marine species of porphyridium (rhodophyta) have been determined. the resultant catalogs have been compared to those obtained for three prokaryotes:escherichia coli, bacillus subtilis, and anacystis nidulans (a blud-green alga). there is extensive sequence homology between the porphyridium chloroplast 16s ribosomal rna and each of the prokaryotic 1 ... | 1975 | 1056032 |
| on the origin of plastids. | the buoyant density in cscl of ribosomes from chloroplasts of the green alga chlorella pyrenoidosa and two species of higher plants, pisum sativum and chenopodium album, has been studied. from the relative protein content it was calculated that 70s ribosomes from chloroplasts are much smaller than 80s cytoplasmic ribosomes (3.0-3.1 x 10(6) and 4.0 x 10(6) daltons) and slightly larger than 70s ribosomes from bacteria (e. coli 2.5 x 10(6) daltons). chloroplast ribosomes from pea seedlings were ana ... | 1975 | 1103046 |
| the begginning of photosynthesis. | there is no evolutionary continuity between photochemical abiosynthesis and bacterial photosynthesis. rather, the photosynthetic bacteria are descendants of fermenters that did not use light. photosynthesis and respiration, both using electron flow coupled with phosphorylation, have a common origin ('conversion hypothesis'), but photosynthesis came first. anaerobic (nitrate or sulphate) respiration cannot have preceded photosynthesis as neither nitrate nor sulphate existed on the early earth. su ... | 1975 | 1153184 |
| toxic effects of omega chrome red me and its treatment by adsorption. | toxic effects of omega chrome red me, a popular textile dye, on the nitrogen fixing cyanobacterium nostoc calcicola were studied. the growth of n. calcicola was found to be suppressed at 10 and 20 mg liter-1 initial concentrations of dye, whereas a low initial concentration of 5 mg liter-1 slightly favors growth. removal of the dye was carried out by adsorption using some cheap and unconventional adsorbents like coal, fly ash, wollastonite, and china clay. it has been observed that, in all cases ... | 1992 | 1280581 |
| analysis of the gene encoding the rna subunit of ribonuclease p from cyanobacteria. | the genes encoding the rna subunit of ribonuclease p from the unicellular cyanobacterium synechocystis sp. pcc 6803, and from the heterocyst-forming strains anabaena sp. pcc 7120 and calothrix sp. pcc 7601 were cloned using the homologous gene from anacystis nidulans (synechococcus sp. pcc 6301) as a probe. the genes and the flanking regions were sequenced. the genes from anabaena and calothrix are flanked at their 3'-ends by short tandemly repeated repetitive (strr) sequences. in addition, two ... | 1992 | 1282240 |
| uncultivated cyanobacteria, chloroflexus-like inhabitants, and spirochete-like inhabitants of a hot spring microbial mat. | analysis of 16s rrna sequences retrieved as cdna (16s rcdna) from the octopus spring cyanobacterial mat has permitted phylogenetic characterization of some uncultivated community members, expanding our knowledge or diversity within this microbial community. two new cyanobacterial 16s rrna sequences were discovered, raising to four the number of cyanobacterial sequence types known to occur in the mat. none of the sequences found is that of the cultivated thermophilic cyanobacterium synechococcus ... | 1992 | 1282313 |
| a specific stain for the detection of nonheme iron proteins in polyacrylamide gels. | nonheme iron proteins can be visualized as blue bands in native polyacrylamide gels using a staining method that is both simple and rapid. the reaction of potassium ferricyanide with protein-bound iron atoms to form royal blue complexes occurs almost instantaneously and is sensitive enough to detect 1 microgram of analytical-grade ferritin and 2 micrograms of purified ferredoxin from cyanobacteria. no special treatment of reagents or apparatus was necessary. on comparison, this stain was found t ... | 1992 | 1282787 |
| cyanobiont diversity within and among cycads of one field site. | limited diversity was found among cyanobionts from a cultivated population of cycads at a field site in florida. all isolates were classified as nostoc but were different from the one nostoc species found in the soil. these cyanobacteria were root endophytes of several plants of zamia integrifolia and one of dioon. the isolates were similar morphologically and in their reactions to four fluorescein isothiocyanate conjugated lectins. electrophoretic protein profiles and zymograms distinguished on ... | 1992 | 1288849 |
| synthesis of chimeric rnas between u6 small nuclear rna and (-)strsv and analysis of their cleavage activities against the substrate rna. | u6 small nuclear rna (u6 snrna) is one of the spliceosomal rnas essential for pre-mrna splicing. highly conserved region of u6 snrna shows a structural similarity with the catalytic center of the negative strand of the satellite rna of tobacco ring spot virus [(-)strsv], supporting the hypothesis that u6 snrna has a catalytic role in pre-mrna splicing. to test this hypothesis, we examined in vitro whether synthetic rnas consisting of the sequence of the highly conserved region of u6 snrna or var ... | 1992 | 1289815 |
| gene phylogenies and the endosymbiotic origin of plastids. | the endosymbiotic origin of chloroplasts from cyanobacteria has long been suspected and has been confirmed in recent years by many lines of evidence. debate now is centered on whether plastids are derived from a single endosymbiotic event or from multiple events involving several photosynthetic prokaryotes and/or eukaryotes. phylogenetic analysis was undertaken using the inferred amino acid sequences from the genes psba, rbcl, rbcs, tufa and atpb and a published analysis (douglas and turner, 199 ... | 1992 | 1292669 |
| iron bioavailability from spirulina platensis, whole egg and whole wheat. | bioavailability of iron from spirulina was assessed in comparison with whole egg, whole wheat and standard ferrous sulphate using haemoglobin depletion repletion assay. haemoglobin regeneration efficiency of spirulina and whole egg was similar and significantly higher than that of whole wheat. the absorption of iron from spirulina was significantly lower than that of ferrous sulphate and whole egg but significantly greater than that from whole wheat. | 1992 | 1293017 |
| [study on the medium (balm) for isolation of legionella pneumophila]. | l. pneumophila was apparently using blue algae (cyanobacteria) extracellular products as carbon and energy sources for its proliferation. based on this observation, a medium (balm) in which all chemicals and reagents were made in china for isolation of l. pneumophila was developed. the recoveries of l. pneumophila serogroups 1 and 6 standard strains from contaminated air-conditional water and infected guinea pig spleens were evaluated by using two culture media: balm and bcye (buffered charcoal ... | 1992 | 1300253 |
| [cloning and expression of the clostridium thermocellum gene in cyanobacteria anacystis nidulans r2 cells]. | the xhoi-salgi fragment of the plasmid pci dna was inserted into the salgi site of the cyanobacterium anacystis nidulans r2 integrative vector plasmid piah4. the fragment incorporates the endoglucanase gene of clostridium thermocellum cloned earlier within the 6.7 kb dna sequence. the recombinant plasmid dna was transformed into anacystis nidulans r2 cells. the cloned endoglucanase gene was shown to express in the cyanobacterium cells. the enzyme synthesized is accumulated within the cytoplasm o ... | 1992 | 1301503 |
| [continuous biological test procedures for monitoring waste water and event controlled sampling techniques]. | | 1992 | 1307793 |
| protein phosphorylation in regulation of photosynthesis. | | 1992 | 1310622 |
| oxygen-evolving photosystem ii preparation from wild type and photosystem ii mutants of synechocystis sp. pcc 6803. | we present here a simple and rapid method which allows relatively large quantities of oxygen-evolving photosystem ii- (ps-ii-) enriched particles to be obtained from wild-type and mutants of the cyanobacterium synechocystis 6803. this method is based on that of burnap et al. [burnap, r., koike, h., sotiropoulou, g., sherman, l. a., & inoue, y. (1989) photosynth. res. 22, 123-130] but is modified so that the whole preparation, from cells to ps-ii particles, is achieved in 10 h and involves only o ... | 1992 | 1311205 |
| absorption of color additives and settling volume in water of blue-green alga, ishikurage (nostoc commune). | the properties of ishikurage (nostoc commune) and other algae were compared. ishikurage and suizenji nori (aphanothece sacrum) absorbed much more amaranth than others. they have a high settling volume (sv) in water. the high sv of ishikurage is attributable to its neutral detergent fiber (ndf). the acid detergent fiber (adf) from the alga had a high amaranth absorption. however the absorption by the adf did not explain the absorption by ishikurage. the results suggest that ishikurage may have a ... | 1992 | 1312238 |
| characterization of the multiple epr line shapes of iron-semiquinones in photosystem 2. | we have compared the temperature-dependence characteristics of the epr signals of qa and qb iron-semiquinones from both purple bacterial and plant photosystems. the data obtained were analyzed and estimates of the splitting parameters of the non-heme fe2+ spin sublevels obtained. the study confirms the similarities of the g = 1.8 qa iron-semiquinone signal (d/k = 15.6 k, e/k = 3.3 k) formed in formate-treated plant photosystem 2 to the signal found in purple bacteria. however, the g = 1.9 qa iro ... | 1992 | 1312858 |
| the yf161d1 mutant of synechocystis 6803 exhibits an epr signal from a light-induced photosystem ii radical. | the currently accepted model for the location of the redox-active tyrosines, d and z, in photosystem ii suggests that they are symmetrically located on the d1 and d2 polypeptides, which are believed to form the heterodimer core of the reaction center. z, the electron conduit from the manganese catalytic site to the primary chlorophyll donor, has been identified with tyrosine-161 of d1. the yf161d1 mutant of synechocystis 6803 [debus, r. j., barry, b. a., sithole, i., babcock, g. t., & mcintosh, ... | 1992 | 1313291 |
| nmr studies on na+ transport in synechococcus pcc 6311. | the freshwater cyanobacterium synechococcus pcc 6311 is able to adapt to grow after sudden exposure to salt (nacl) stress. we have investigated the mechanism of na+ transport in these cells during adaptation to high salinity. na+ influx under dark aerobic conditions occurred independently of delta ph or delta psi across the cytoplasmic membrane, atpase activity, and respiratory electron transport. these findings are consistent with the existence of na+/monovalent anion cotransport or simultaneou ... | 1992 | 1314538 |
| stoichiometric association of extrinsic cytochrome c550 and 12 kda protein with a highly purified oxygen-evolving photosystem ii core complex from synechococcus vulcanus. | a highly purified, native photosystem ii (ps ii) core complex was isolated from thylakoids of synechococcus vulcanus, a thermophilic cyanobacterium by lauryldimethylamine n-oxide (ldao) and dodecyl beta-d-maltoside solubilization. this native ps ii core complex contained, in addition to the proteins that have been well characterized in the core complex previously purified by ldao and triton x-100, two more extrinsic proteins with apparent molecular weights of 17 and 12 kda. these two proteins we ... | 1992 | 1314738 |
| site-directed conversion of a cysteine to aspartate leads to the assembly of a [3fe-4s] cluster in psac of photosystem i. the photoreduction of fa is independent of fb. | the terminal electron acceptors fa and fb exist as two [4fe-4s] clusters located on the 8.9-kda psac protein in photosystem i. we have used site-directed mutagenesis to produce a complementary pair of mutant psac proteins in which specific cysteine ligands to the [4fe-4s] clusters were changed to aspartic acid residues. the mutant proteins, denoted c14d and c51d, were overproduced in escherichia coli; the iron-sulfur clusters were inserted in vitro; and the reconstituted proteins were rebound to ... | 1992 | 1318744 |
| evidence from directed mutagenesis that aspartate 170 of the d1 polypeptide influences the assembly and/or stability of the manganese cluster in the photosynthetic water-splitting complex. | to identify amino acid residues that influence the assembly or stability of the manganese cluster in photosystem ii, we have generated site-directed mutations in the d1 polypeptide of the cyanobacterium, synechocystis sp. pcc 6803. indirect evidence has suggested that the d1 polypeptide provides some of the ligands that are required for metal binding. mutations at position 170 of d1 were selected for characterization, since an aspartate to asparagine mutation (dn170d1) at this position completel ... | 1992 | 1322168 |