| quantitative analysis of the elemental composition and the mass of bacterial polyphosphate bodies using stem edx. | the quantitative analysis of laboratory grown organisms (plectonema boryanum and staphylococcus aureus) revealed that a typical in vivo polyphosphate body (ppb) contains o (4.3 x 10(-8) microg), c (1.2 x 10(-8) microg), p (6.7 x 10(-9) microg), mg (1.3 x 10(-9) microg), ca (6.7 x 10(-10) microg), k (6.7 x 10(-10) microg), fe (6.0 x 10(-10) microg), s (5.4 x 10(-10) microg) and al (5.9 x 10(-10) microg). quantitative x-ray analysis of samples from nature showed ppb contain o (1.63 x 10(-8) microg ... | 2001 | 11522129 |
| the evolution of glutathione metabolism in phototrophic microorganisms. | of the many roles ascribed to glutathione (gsh) the one most clearly established is its role in the protection of higher eucaryotes against oxygen toxicity through destruction of thiol-reactive oxygen byproducts. if this is the primary function of gsh then gsh metabolism should have evolved during or after the evolution of oxygenic photosynthesis. that many bacteria do not produce gsh is consistent with this view. in the present study we have examined the low-molecular-weight thiol compositio ... | 1987 | 11542078 |
| [physical mapping of plasmid psm1 of the cyanobacterium plectonema boryanum gom. strain calu 465]. | a physical map of plasmid psm1 has been compiled as a result of restriction analysis of pbsmi isolated from the cells of cyanobacterium plectonema boryanum 465. a comparative analysis of the restriction sites localization in dna of plasmid psm1 with site topology of plasmids pgl3 of p. boryanum and ppf1 of phormidium foveolarum indicates to high degree of these plasmids homology. | 2001 | 11692681 |
| [construction of the shuttle vector psts1 and development of the method of its introduction into the cells of the cyanbacterium plectonema boryanum calu 465]. | it has been shown that cells of trichoma cyanobacterium plectonema boryanum g o m. strain calu 465 do not possess natural resistance to antibiotics ampicyllin, chloramphenicol, streptomycin and canamycin. a shuttle vector psts1 has been constructed on the basis of cyanobacterial plasmid psm1 and vector pbr 322. conditions have been developed and conjugative transfer of psts1 to the cells of cyanobacterium p. boryanum has been performed. as the result of expression of beta-lactamase gene psts1 th ... | 2001 | 11785421 |
| the presence of an iron-sulfur cluster in adenosine 5'-phosphosulfate reductase separates organisms utilizing adenosine 5'-phosphosulfate and phosphoadenosine 5'-phosphosulfate for sulfate assimilation. | it was generally accepted that plants, algae, and phototrophic bacteria use adenosine 5'-phosphosulfate (aps) for assimilatory sulfate reduction, whereas bacteria and fungi use phosphoadenosine 5'-phosphosulfate (paps). the corresponding enzymes, aps and paps reductase, share 25-30% identical amino acids. phylogenetic analysis of aps and paps reductase amino acid sequences from different organisms, which were retrieved from the genbank(tm), revealed two clusters. the first cluster comprised know ... | 2002 | 11940598 |
| [development of the method of rna labeling in vitro using the terminal transferase with the purpose to obtain hybridization probes]. | a possibility to use terminal transferase to obtain hybridized rna-probes has been investigated. optimal conditions of the reaction proceeding were elaborated on the model objects--rna of the phage ms2: 200 mm of potassium cacodylate, ph 7.2, 1 mm cocl2, 1 mm dtt, under the considerable surplus of the enzyme. the elaborated method was used to determine the area of early genes of cyanophage lpp-3. with this purpose total rna preparations were isolated from cyanobacterium plectonema boryanum calu ... | 2002 | 11944348 |
| stoichiometry of the photosynthetic apparatus and phycobilisome structure of the cyanobacterium plectonema boryanum utex 485 are regulated by both light and temperature. | the role of growth temperature and growth irradiance on the regulation of the stoichiometry and function of the photosynthetic apparatus was examined in the cyanobacterium plectonema boryanum utex 485 by comparing mid-log phase cultures grown at either 29 degrees c/150 micromol m(-2) s(-1), 29 degrees c/750 micromol m(-2) s(-1), 15 degrees c/150 micromol m(-2) s(-1), or 15 degrees c/10 micromol m(-2) s(-1). cultures grown at 29 degrees c/750 micromol m(-2) s(-1) were structurally and functionall ... | 2002 | 12428006 |
| [use of cyanobacteria for indication of toxic action of stachybotrys toxins]. | screening of cyanobacteria cultures for their sensitivity to the action of complex preparations of toxins from 18 strains of stachybotrys chartarum has been carried out with the purpose to search for new test-organisms to create a reliable system of biotesting of stachibotryotoxines. in contrast to other cultures of unicell (anacystis nidulans) and filamentous (anabaena sp., anabaena variabilis, nostoc linckia, plectonema boryanum) cyanobacteria used in the experiment, only one culture of unicel ... | 2002 | 12436869 |
| arrest of chlorophyll synthesis and differential decrease of photosystems i and ii in a cyanobacterial mutant lacking light-independent protochlorophyllide reductase. | the chll gene encodes one subunit of the light-independent protochlorophyllide reductase. a chll-lacking mutant of the cyanobacterium plectonema boryanum is unable to synthesize chlorophyll (chl) in the dark, causing chl synthesis to become light-dependent as in angiosperms. when the mutant cells were cultivated heterotrophically in the dark, chl synthesis was arrested and the chl content decreased exponentially in reverse profile to cell propagation, indicating that most of the pre-existing chl ... | 2003 | 12602881 |
| an alternate photosynthetic electron donor system for psi supports light dependent nitrogen fixation in a non-heterocystous cyanobacterium, plectonema boryanum. | plectonema boryanum exhibits temporal separation of photosynthesis and nitrogen fixation under diazotrophic conditions. during nitrogen fixation, the photosynthetic electron transport chain becomes impaired, which leads to the uncoupling of the psii and psi activities. a 30-40% increase in psi activity and continuous generation of atp through light-dependent processes seem to support the nitrogen fixation. the use of an artificial electron carrier that shuttles electrons between the plastoquinon ... | 2003 | 12685043 |
| [associative cyanobacteria isolated from the roots of epiphytic orchids]. | associative cyanobacteria were isolated from the rhizoplane and velamen of the aerial roots of the epiphytic orchids acampe papillosa, phalaenopsis amabilis, and dendrobium moschatum and from the substrate roots of acampe papillosa and dendrobium moschatum. cyanobacteria were isolated on complete and nitrogen-free variants of bg-11 medium. on all media and in all samples, cyanobacteria of the genus nostoc predominated. nostoc, anabaena, and calothrix were isolated from the surface of the a. papi ... | 2003 | 12698800 |
| [comparative characteristics of native proteinases of the cyanobacteria plectonema boryanum and anabaena variabilis and those induced by cyanophages]. | physico-chemical and catalytic properties of proteinases of native and induced cells of cyanobacteria plectonema boryanum have been comparatively studied. it has been established that at early stages of reproduction of cyanophage lpp-3 in cyanobacteria p. boryanum is formed de novo proteinase complex consisting at least of five enzymes. proteinases induced by the virus are distinguished from those of native cells by a series of physico-chemical characteristics and possess higher catalytic activi ... | 2003 | 12945190 |
| [construction of vector plasmids for the plectonema boryanum cyanobacterium and creation, on such basis, of the vector-host system]. | the plasmid composition of the plectonema boryanum gom. cyanobacterium, strain calu 465, was analyzed. a small psm1 plasmid, size 1.5, was chosen for genetic engineering. the physical map, constructed for the plasmid, was used to create the psts series, i.e. vector construction for the p. boryanum cyanobacterium. a method was selected and tested for the introduction of the vector into host cells. the needed orientation of psm1 cyanobacterium plasmid within the vector as well as a possible role o ... | 2003 | 12966925 |
| algal virus: isolation. | freshwater blue-green algae of the genera lyngbya, plectonema, and phormidium are susceptible to a virus recently isolated from a waste-stabilization pond. electron micrographs of a partially purified preparation show that the viral particle has an icosahedral structure about 66 mmicro in diameter. | 1963 | 13976026 |
| [comparative characteristics of physico-chemical and regulating properties of aspartate kinases from three species of cyanobacteria]. | aspartokinases have been isolated from the cell-free extracts of plectonema boryanum, anabaena variabilis and synechococcus cedrorum. their physico-chemical characteristics and peculiarities of retroregulation by amino acids were studied. it has been shown that in p. boryanum cells aspartokinase reaction is catalyzed by only one enzyme, which is similar to the previously described bacterial origin enzymes. three izoenzymes, which differ in their main properties and amino acids-effectors, have be ... | 2002 | 14964871 |
| determination of nitrogen-fixing phylotypes in lyngbya sp. and microcoleus chthonoplastes cyanobacterial mats from guerrero negro, baja california, mexico. | in many environments, biological nitrogen fixation can alleviate nitrogen limitation. the high rates of n(2) fixation often observed in cyanobacterial mats suggest that n(2) fixation may be an important source of n. in this study, organisms expressing nifh were identified in a lyngbya sp.- and two microcoleus chthonoplastes-dominated cyanobacterial mats. the pattern of nitrogenase activity was determined for the lyngbya sp. mat and a microcoleus chthonoplastes mat sampled directly in guerrero ne ... | 2004 | 15066804 |
| [localization of dnaase activity in cyanobacterium plectonema boryanum calu 465]. | it was shown in experiments carried out on cyanobacterium p. boryanum, that when cells are incubated in a buffer with low concentrations of nonion detergent (0.1%, triton x-100) one can observe the dnase activity release into the medium. the methods of supersound desintegration of cells and following gradient centrifugation of the cell-free extracts were used to obtain three fractions of the cell membranes identified by means of spectrophotometric analysis. it has been established that p. boryan ... | 2003 | 15077546 |
| [isolation and purification of nonspecific nuclease of cyanobacterium plectonema boryanum calu 465]. | nonspecific nuclease has been isolated from the cells of cyanobacterium plectonema boryanum and purified to homogenic state. it has been established that the method of centrifugation of cell-free culture extract in the sucrose density gradient is efficient for the separation of pigment proteins and enzyme concentration. under the successive use of two ion-exchangers the nuclease activity was determined in the concentration range of nacl 0.065-0.085 m after separation of the cell-free cyanobacter ... | 2004 | 15104052 |
| volatile organic compound (voc) analysis and sources of limonene, cyclohexanone and straight chain aldehydes in axenic cultures of calothrix and plectonema. | the volatile organic compounds (vocs) in four standing cultures of axenic benthic cyanobacteria (calothrix and plectonema) were studied by gc/ms analysis. to verify the biogenic origin of the vocs, 13c-labelling experiments were performed, and the differences in labelling were used to differentiate between biogenic and non-biogenic sources. strongly labelled biogenic compounds were derived from the shikimate (cresol, skatole), isoprenoid (beta-cyclocitral, beta-ionone, geosmin) and fatty acid pa ... | 2004 | 15237606 |
| [the nucleotide sequence of the rep gene of cyanobacterial plasmid psm1]. | the nucleotide sequence was established for the rep gene of plasmid psm1 isolated from cyanobacterium plectonema boryanum calu 465. both nucleotide sequence and the encoded amino acid sequences showed 98% homology to the corresponding sequences of small plasmids ppf1, pgl3, ppbs1, pblx, and ppb1. an active center was identified in the replicative protein sequences. | 2004 | 15458212 |
| [psts4--a new shuttle vector for cyanobacterium plectonema boryanum calu 465]. | three vector constructions--psts2, psts3 and psts4 have been obtained on the basis of the standard vector for escherichia coli pbr 322, cyanobacterial plasmid psm1 and its separate fragments. the structure of psts4, carrying the full-size plasmid psm1 (cloned by the restriction site hpa ii), replicated both in the cells of e. coli and in the cells-transconjugants of the trichomal cyanobacterium plectonema boryanum. under these conditions resistance of p. boryanum cells to ampicillin increases th ... | 2004 | 15515899 |
| common freshwater cyanobacteria grow in 100% co2. | cyanobacteria and similar organisms produced most of the oxygen found in earth's atmosphere, which implies that early photosynthetic organisms would have lived in an atmosphere that was rich in co2 and poor in o2. we investigated the tolerance of several cyanobacteria to very high (>20 kpa) concentrations of atmospheric co2. cultures of synechococcus pcc7942, synechocystis pcc7942, plectonema boryanum, and anabaena sp. were grown in liquid culture sparged with co2-enriched air. all four strains ... | 2005 | 15711170 |
| macromolecule metabolism and photosynthetic functions in blue-green algae treated with virginiamycin, an inhibitor of protein synthesis. | the m component of virginiamycin inhibited growth of plectonema boryanum under both photoautotrophic and heterotrophic conditions. though the s component of this antibiotic had no apparent activity per se, it enhanced the inhibitory action of its partner. cells incubated with suitable concentrations of either m or m + s stopped growing and lysed. loss of the colony-forming capacity occurred quickly in the presence of m + s and slowly in the presence of m alone. virginiamycin m inhibited protein ... | 1974 | 15828183 |
| growth, photosynthesis, active oxygen species and antioxidants responses of paddy field cyanobacterium plectonema boryanum to endosulfan stress. | the present paper deals with the insecticide endosulfan (5, 10 and 20 microg/ml)-induced changes in physiological and biochemical parameters related to photosynthesis and defense systems in paddy field cyanobacterium plectonema boryanum grown under laboratory conditions. growth and photosynthetic pigments, i.e., chlorophyll a, carotenoids and phycocyanin, were adversely affected by endosulfan treatment and the inhibition was found to be dose dependent. the toxic effect of endosulfan was more pro ... | 2005 | 15942872 |
| solenoids and plectonemes in stretched and twisted elastomeric filaments. | we study the behavior of a naturally straight highly extensible elastic filament subjected to large extensional and twisting strains. we find that two different phases can coexist for a range of parameter values: the plectoneme and the solenoid. a simple theory based on a neo-hookean model for the material of the filament and accounting for the slender geometry suffices to explain these observations, and leads to a phase diagram that is consistent with observations. extension and relaxation expe ... | 2005 | 16090920 |
| morphology of gold nanoparticles synthesized by filamentous cyanobacteria from gold(i)-thiosulfate and gold(iii)--chloride complexes. | plectonema boryanum utex 485, a filamentous cyanobacterium, has been reacted with aqueous au(s(2)o(3))(2)(3)(-) and aucl(4)(-) solutions ( approximately 400-550 mg/l au) at 25-100 degrees c for up to 1 month and at 200 degrees c for 1 day. the interaction of cyanobacteria with aqueous au(s(2)o(3))(2)(3)(-) promoted the precipitation of cubic (100) gold nanoparticles (<10-25 nm) at membrane vesicles and admixed with gold sulfide within cells and encrusted on the cyanobacteria, whereas reaction wi ... | 2006 | 16519482 |
| degradation of crude oil by marine cyanobacteria. | the marine cyanobacteria oscillatoria salina biswas, plectonema terebrans bornet et flahault and aphanocapsa sp. degraded bombay high crude oil when grown in artificial seawater nutrients as well as in plain natural seawater. oil removal was measured by gravimetric and gas chromatographic methods. around 45-55% of the total fractions of crude oil (containing 50% aliphatics, 31% waxes and bitumin, 14% aromatics and 5% polar compounds) were removed in the presence of these cultures within 10 days. ... | 2001 | 11759698 |
| therapeutical effect of modified adamantane copolymer compounds: study of molecular mechanisms. | copolymers of n-polyvinylpyrrolidone-acrylic acid (ab-1) and adamantane derivatives are known to possess marked antiviral activity in in vitro and in ovo models. among the constructed preparations of ab-1 modified by adamantane derivatives some, especially ab-4 (modified by deitiforin), were found to show more extended antiviral activity and to inhibit markedly virus reproduction in susceptible permissive cell cultures and chicken embryos. in ab-4 treated cells and allantoic sacs, virus titers ( ... | 2001 | 11440176 |
| dna sequence and shuttle vector construction of plasmid pgl3 from plectonema boryanum pcc 6306. | | 1993 | 8441688 |
| physiological aspects of alkaline phosphatase in selected cyanobacteria. | the alkaline phosphatase of plectonema boryanum shows a considerable increase in activity following placement of the cells in a phosphate free medium. five days of phosphate starvation result in a 14-fold increase of alkaline phosphatase activity. growth in the presence of inhibitors of transcription and translation indicate that the synthesis of the enzyme is de novo. orthophosphate causes an immediate inhibition of enzyme activity. enzyme was extracted from p. boryanum with lysozyme or polymyx ... | 1980 | 6793813 |
| sequence of morphological alterations in blue-green algae in the course of cyanophage infection. | electron microscopic studies were performed on the sequence of morphological alterations induced by the cyanophage pp-1 in the blue-green algae phormidium sp. and plectonema boryanum. the following phases of virus infection were made evident: virus adsorption onto the host cell; the presence of virus "ghosts", suggesting the penetration of viral dna into the cell and its multiplication in the nucleoplasm; invagination of thylakoids and formation of the "virogenic stroma"; virus maturation within ... | 1981 | 6787795 |
| short-trichome mutant of plectonema boryanum. | | 1969 | 5773043 |
| lpp-1 infection of the blue-green alga plectonema boryanum. ii. viral deoxyribonucleic acid synthesis and host deoxyribonucleic acid breakdown. | host and viral deoxyribonucleic acid (dna) metabolism in lpp-1-infected plectonema boryanum was studied by equilibrium centrifugation in cscl gradients. approximately 50% of the host dna is degraded to acid-soluble material between 3 and 7 hr after infection. most of the acid-soluble product is reincorporated into viral dna. incorporation of exogenous (3)h-adenine into viral dna can be detected very early after infection (within the first 2 hr), but the bulk of viral dna synthesis occurs between ... | 1970 | 4992999 |
| lpp-1 infection of the blue-green alga plectonema boryanum. i. electron microscopy. | one-step growth and intracellular growth experiments were performed at high multiplicities of the virus lpp-1 during the infection of the blue-green alga plectonema boryanum. the eclipse period lasts until 4 hr after infection, the latent period terminates at 6 hr, and the rise period continues until 14 to 16 hr after infection. the burst size was independent of multiplicity of infection over the ranges from 1 to 50. the burst size was 3,000 to 5,000 plaque-forming units (pfu) per infectious cen ... | 1970 | 4992998 |
| restriction analysis and quantitative estimation of methylated bases of filamentous and unicellular cyanobacterial dnas. | the dnas of strains of three cyanobacterial genera (anabaena, plectonema, and synechococcus) were found to be partially or fully resistant to many restriction endonucleases. this could be due to the absence of specific sequences or to modifications, rendering given sequences resistant to cleavage. the latter explanation is substantiated by the content of n6-methyladenine and 5-methylcytosine in these genomes, which is high in comparison with that in other bacterial genomes. dcm- and dam-like met ... | 1988 | 2832390 |
| lysogeny of blue-green alga plectonema boryanum by long tailed virus. | lysogeny and its induction with mitomycin c by the long tailed virus is reported. the active virus was liberated in the medium during the growth period and ability of trichomes to produce virus was not reduced by treatment with edta. | 1975 | 810657 |
| [effect of several plant growth regulators on various prokaryotes and their viruses]. | 26 plant growth regulators including herbicides were investigated in their effect on the multiplication of escherichia coli, bacillus subtilis, and the blue-green alga plectonema boryanum as well as the rna phages m 12 and qbeta and the dna phages lambda, phi 105, and lpp-1 employing the agar diffusion method. nearly all of the compounds inhibited and/or stimulated one or some of the prokaryotes tested. the most frequent and strongest effects occurred in pl. boryanum, the least effects in e. col ... | 1975 | 809932 |
| photoreactivation of uv-irradiated blue-green algae and algal virus lpp-1. | ultraviolet (uv) sensitivity and photoreactivation of blue-green algae cylindrospermum sp., plectonema boryanum, spores of fischerella muscicola and algal virus (cyanophage) lpp-1 were studied. the survival value after uv irradiation of filaments of cylindrospermum sp. and virus lpp-1 showed exponential trend and these were comparatively sensitive towards uv than f.muscicola and p.boryanum. photoreactivation of uv-induced damage occurred in black, blue, green, yellow, red and white light in cyli ... | 1975 | 807175 |
| the geomicrobiology of gold. | microorganisms capable of actively solubilizing and precipitating gold appear to play a larger role in the biogeochemical cycling of gold than previously believed. recent research suggests that bacteria and archaea are involved in every step of the biogeochemical cycle of gold, from the formation of primary mineralization in hydrothermal and deep subsurface systems to its solubilization, dispersion and re-concentration as secondary gold under surface conditions. enzymatically catalysed precipita ... | 2007 | 18043665 |
| ethionine-resistant mutants of the filamentous blue-green alga plectonema boryanum. | plectonema boryanum mutants that are resistant to ethionine are unable to incorporate ethionine into acid-precipitable material. ethionine causes bleaching of chlorophyll in sensitive cells. | 1978 | 417071 |
| inhibition of lytic induction in lysogenic cyanophyces. | when the lysogenic strain spicts1 of the blue-green alga plectonema boryanum carrying a temperature-sensitive mutation in the lpp2 prophage was heated at a nonpermissive temperature in the light, a lytic cycle occurred, with production of infectious viral particles. inhibitors of transcription, translation, and photosynthetic functions interfered with this process and produced different effects when administered at different phases of the viral cycle. the presence of the inhibitors during the te ... | 1977 | 408514 |
| assembly site of cyanophage lpp-2-spi in plectonema boryanum. | electron microscope studies of infection by the temperature cyanophage spi show two possible assembly sites within the host plectonema boryanum: the nucleoplasm and a phage-created space, the "virogenic stroma". induced prophages appear to develop preferentially in the nucleoplasm. | 1977 | 402745 |
| 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 |
| Cyanobacteria-mediated phenylpropanoids and phytohormones in rice (Oryza sativa) enhance plant growth and stress tolerance. | Phenylpropanoids, flavonoids and plant growth regulators in rice (Oryza sativa) variety (UPR 1823) inoculated with different cyanobacterial strains namely Anabaena oryzae, Anabaena doliolum, Phormidium fragile, Calothrix geitonos, Hapalosiphon intricatus, Aulosira fertilissima, Tolypothrix tenuis, Oscillatoria acuta and Plectonema boryanum were quantified using HPLC in pot conditions after 15 and 30-ádays. Qualitative analysis of the induced compounds using reverse phase HPLC and further confirm ... | 2011 | 21732035 |
| observations on the mechanisms of attachment of some marine fouling blue-green algae. | using scanning electron microscopy (sem), differential interference contrast microscopy (dicm) and cytochemical staining techniques, preliminary observations have been made on the mechanisms of attachment of some common, marine, benthic fouling blue-green algae ("cyanobacteria") isolated into culture from various toxic and non-toxic surfaces in langstone harbour, south coast of england. blue-green algae investigated included species of calothrix, dermocarpa, plectonema, phormidium and xenococcus ... | 1996 | 22115109 |
| h+ translocation in lysozyme-treated cells of the blue-green alga plectonema boryanum. difference between isotonically and hypotonically treated preparations and effects of divalent cations. | lysozyme-treated cells of a blue-green alga, plectonema boryanum, had an internal ph of 7.3+/-0.2 under isotonic and hypotonic conditions. this value was similar to that of untreated cells. the cccp-induced biphasic h+ change seen in the isotonic cells was not observed in the hypotonically treated cells. the biphasic time course remained in the hypotonic preparation if cacl2 or mgcl2 was added prior to the osmotic shock. it is suggested that the cells have two compartments of h+ concentration. t ... | 1977 | 21172 |
| toxicity of ammonia to algae in sewage oxidation ponds. | ammonia, at concentrations over 2.0 mm and at ph values over 8.0, inhibits photosynthesis and growth of scenedesmus obliquus, a dominant species in high-rate sewage oxidation ponds. photosynthesis of chlorella pyrenoidosa, anacystis nidulans, and plectonema boryanum is also susceptible to ammonia inhibition. dark respiration and cell morphology were unaffected by any combination of ph and ammonia concentrations tested, thus limiting the apparent effect to inhibition of the normal function of the ... | 1976 | 7192 |
| 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 |
| accumulation of trehalose and sucrose in cyanobacteria exposed to matric water stress. | the drought-resistant cyanobacteria phormidium autumnale, strain lpp(4), and a chroococcidiopsis sp. accumulated trehalose, sucrose, and both trehalose and sucrose, respectively, in response to matric water stress. accumulated sugar concentrations reached values of up to 6.2 mug of trehalose per mug of chlorophyll in p. autumnale, 6.9 mug of sucrose per mug of chlorophyll in lpp(4), and 4.1 mug of sucrose and 3.2 mug of trehalose per mug of chlorophyll in the chroococcidiopsis sp. the same sugar ... | 1991 | 16348431 |
| laboratory comparison of the effectiveness of several algicides on isolated swimming pool algae. | the most frequently encountered species of algae found in swimming pools in the phoenix metropolitan area were used to evaluate the laboratory effectiveness of five commercially available pool chemicals used for algal control. the pool algae used were the xanthophyte pleurochloris pyrenoidosa, the chlorophyte oocystis sp., and the cyanophytes phormidium minnesotense and plectonema sp. pad algae kill (a chlorine derivative) was effective in the control of all test organisms. algaedyn, a silver-co ... | 1980 | 16345508 |
| genetic potential for secondary metabolite production in stromatolite communities. | the cyanobacterial communities associated with stromatolites surviving in extreme habitats are a potentially rich source of bioactive secondary metabolites. we screened for the potential for production of bioactive metabolites in diverse species of cyanobacteria isolated from stromatolites in hamelin pool, shark bay, australia. using degenerate primer sets, putative peptide synthetase and polyketide synthase genes were detected from strains of symploca, leptolyngybya, microcoleus, pleuorocapsa, ... | 2005 | 15668032 |
| microbial diversity of extant stromatolites in the hypersaline marine environment of shark bay, australia. | stromatolites have been present on earth, at various levels of distribution and diversity, for more than 3 billion years. today, the best examples of stromatolites forming in hypersaline marine environments are in hamelin pool at shark bay, western australia. despite their evolutionary significance, little is known about their associated microbial communities. using a polyphasic approach of culture-dependent and culture-independent methods, we report the discovery of a wide range of microorganis ... | 2004 | 15344935 |
| periphyton as an indicator of water quality in the st lawrence river (québec, canada). | the performance of various algal indices to document improvements in water quality across a low nutrient concentration gradient was assessed during 2 years in the st lawrence river (quebec, canada). water-quality variables and periphyton samples were collected on navigational buoys near montreal during the spring, summer and fall of 1994 and 1995. exposure to urban wastewater varied widely within the sector surrounding the island of montreal, with some areas upstream receiving no direct effluent ... | 1998 | 15093094 |
| [construction of shuttle expression vector and expression of thymosin alpha 1 in synechococcus sp. pcc7942]. | the shutter expression vector ppreut was constructed from the plasmid pprs-1 containing the endogenous small plasmid of plectonema boryanum. the expression elements such as heat shock gene groesl promoter, foreign gene ub-thymosin alpha 1, rbcs polya terminator and kanamycin resistance gene were all included. the shutter plasmid ppreut was directly transferred into synechococcus sp. pcc7942. the transformants were obtained through kanamycin screening. southern blotting analysis showed that the s ... | 2003 | 12751202 |
| temperature dependence of chlorophyll a fluorescence in relation to the physical phase of membrane lipids algae and higher plants. | the temperature dependence of the yield of chlorophyll a fluorescence was measured at room temperatures in living algal cells and higher plant chloroplasts. 3-(3',4'-dichlorophenyl)-1, 1-dimethylurea was added to the samples during the measurements in order to eliminate the influence of photosynthetic photochemical reactions on the fluorescence yield.in anacystis nidulans the maximum in the curve for the fluorescence yield versus temperature occurred near the temperatures at which the transition ... | 1975 | 16659396 |
| kinetic variance of ribulose-1,5-bisphosphate carboxylase/oxygenase isolated from diverse taxonomic sources : ii. analysis by two dual label methods. | two dual label methods were used to investigate kinetic variability of ribulose 1,5-bisphosphate (rubp) carboxylase/oxygenase (ec 4.1.1.39). in addition to using [1-(14)c,5-(3)h]rubp (method 1), we describe here the detailed assay with (14)co(2) and [5-(3)h]rubp (method 2), which generates [(3)h,(14)c]3-phosphoglyceric acid and unlabeled (noncontaminating) phosphoglycolate; the carboxylase/oxygenase activity ratio (v(c)/v(o)) is calculated from (3)h/(14)c ratios of substrates and products. v(c)/ ... | 1984 | 16663680 |
| effect of betaine on enzyme activity and subunit interaction of ribulose-1,5-bisphosphate carboxylase/oxygenase from aphanothece halophytica. | the presence of betaine, a quaternary ammonium compound, at a concentration (0.5 molar) reported to accumulate inside aphanothece halophytica in response to increasing external salinity, slightly promoted ribulose-1,5-bisphosphate (rubp) carboxylase activity. kcl at 0.25 molar inhibited rubp carboxylase about 55%. betaine relieved the inhibition by 0.25 m kcl and the original uninhibited activity was restored at 1 m betaine. other osmoregulatory solutes such as sucrose and glycerol also reduced ... | 1986 | 16664941 |
| boron requirement in cyanobacteria : its possible role in the early evolution of photosynthetic organisms. | the effect of boron on heterocystous and nonheterocystous dinitrogen fixing cyanobacteria was examined. the absence of boron in culture media inhibited growth and nitrogenase activity in nodularia sp., chlorogloeopsis sp., and nostoc sp. cultures. examinations of boron-deficient cultures showed changes in heterocyst morphology. however, cultures of nonheterocystous cyanobacteria, gloeothece sp. and plectonema sp., grown in the absence of boron did not show any alteration in growth or nitrogenase ... | 1990 | 16667889 |
| chromophores of allophycocyanin and r-phycocyanin. | the biliprotein allophycocyanin was purified from phormidium luridum, anabaena variabilis and plectonema boryanum. r-phycocyanin was purified from rhodymenia palmata. the chromophores were cleaved from the denatured protein by methanol hydrolysis. they were purified and crystallized as the dimethyl esters. chromatographic and absorption-spectral (visible-ultraviolet and infrared) comparisons with reference material have established phycocyanobilin as the chromophore of allophycocyanin. phycocyan ... | 1967 | 16742564 |
| synthesis of platinum nanoparticles by reaction of filamentous cyanobacteria with platinum(iv)-chloride complex. | interaction of cyanobacteria (plectonema boryanum utex 485) with aqueous platinum(iv)-chloride (ptcl(4) degrees ) has been investigated at 25-100 degrees c for up to 28 days, and 180 degrees c for 1 day. the addition of ptcl(4) degrees to the cyanobacteria culture initially promoted the precipitation of pt(ii)-organic material as amorphous spherical nanoparticles (< or =0.3 microm) in solutions and dispersed nanoparticles within bacterial cells. the spherical pt(ii)-organic nanoparticles were co ... | 2006 | 16893232 |
| differential operation of dual protochlorophyllide reductases for chlorophyll biosynthesis in response to environmental oxygen levels in the cyanobacterium leptolyngbya boryana. | most oxygenic phototrophs, including cyanobacteria, have two structurally unrelated protochlorophyllide (pchlide) reductases in the penultimate step of chlorophyll biosynthesis. one is light-dependent pchlide reductase (lpor) and the other is dark-operative pchlide reductase (dpor), a nitrogenase-like enzyme assumed to be sensitive to oxygen. very few studies have been conducted on how oxygen-sensitive dpor operates in oxygenic phototrophic cells. here, we report that anaerobic conditions are re ... | 2006 | 17028153 |
| mechanisms of gold bioaccumulation by filamentous cyanobacteria from gold(iii)-chloride complex. | the mechanisms of gold bioaccumulation by cyanobacteria (plectonema boryanum utex 485) from gold(iii)-chloride solutions have been studied at three gold concentrations (0.8,1.7, and 7.6 mm) at 25 degrees c, using both fixed-time laboratory and real-time synchrotron radiation absorption spectroscopy (xas) experiments. interaction of cyanobacteria with aqueous gold(iii)-chloride initially promoted the precipitation of nanoparticles of amorphous gold(i)-sulfide at the cell walls, and finally deposi ... | 2006 | 17120557 |
| biosynthesis of silver nanoparticles by filamentous cyanobacteria from a silver(i) nitrate complex. | the biosynthesis of silver nanoparticles has been successfully conducted using plectonema boryanum utex 485, a filamentous cyanobacterium, reacted with aqueous agno3 solutions (approximately 560 mg/l ag) at 25-100 degrees c for up to 28 days. the interaction of cyanobacteria with aqueous agno3 promoted the precipitation of spherical silver nanoparticles and octahedral (111) silver platelets (of up to 200 nm) in solutions. the mechanisms of silver nanoparticles via cyanobacteria could involve met ... | 2007 | 17309217 |
| synthesis of palladium nanoparticles by reaction of filamentous cyanobacterial biomass with a palladium(ii) chloride complex. | the interaction of cyanobacterial biomass (plectonema boryanum utex 485) with aqueous palladium(ii) chloride (pdcl2 degrees ) has been investigated at 25-100 degrees c for up to 28 days. we report that the release of organic materials from the cyanobacteria promoted the precipitation of pd(0) as crystalline spherical and elongate nanoparticles (< or =30 nm), both in solution and as dispersed and encrusted nanoparticles on cyanobacterial cells. in contrast, under abiotic conditions at 100 degrees ... | 2007 | 17658865 |
| dissolution of dead corals by euendolithic microorganisms across the northern great barrier reef (australia). | spatial and temporal variabilities in species composition, abundance, distribution, and bioeroding activity of euendolithic microorganisms were investigated in experimental blocks of the massive coral porites along an inshore-offshore transect across the northern great barrier reef (australia) over a 3-year period. inshore reefs showed turbid and eutrophic waters, whereas the offshore reefs were characterized by oligotrophic waters. the euendolithic microorganisms and their ecological characteri ... | 2008 | 17690835 |
| chromatin fiber structure and plectonemic model of chromosome condensation in drosophila cells. | reversible permeable cells have been used to isolate chromatin structures during the process of chromosome condensation. analysis of individual structures slipping out from nuclei after reversal of permeabilization revealed that chromosomes of drosophila cells consist of small units called rodlets. the fluorescent images of chromatin fibers were subjected to computer analysis allowing the computer-aided visualization of chromatin fibers. the zig-zag array of fibers consisting of 12-15 nucleosome ... | 2008 | 18171101 |
| oxygen sensitivity of a nitrogenase-like protochlorophyllide reductase from the cyanobacterium leptolyngbya boryana. | dark-operative protochlorophyllide (pchlide) oxido-reductase (dpor) is a nitrogenase-like enzyme that catalyzes pchlide reduction, the penultimate step of chlorophyll a biosynthesis. dpor is distributed widely among oxygenic phototrophs such as cyanobacteria, green algae and gymnosperms. to determine how dpor operates in oxygenic photosynthetic cells, we constructed two shuttle vectors for overexpression of strep-tagged l-protein (chll) and strep-tagged nb-protein (chln-chlb) in leptolyngbya bor ... | 2009 | 19643808 |
| hydrogen generation through indirect biophotolysis in batch cultures of the nonheterocystous nitrogen-fixing cyanobacterium plectonema boryanum. | the nitrogen-fixing nonheterocystous cyanobacterium plectonema boryanum was used as a model organism to study hydrogen generation by indirect biophotolysis in nitrogen-limited batch cultures that were continuously illuminated and sparged with argon/co(2) to maintain anaerobiosis. the highest hydrogen-production rate (i.e., 0.18 ml/mg day or 7.3 micromol/mg day) was observed in cultures with an initial medium nitrate concentration of 1 mm at a light intensity of 100 micromol/m(2) s. the addition ... | 2010 | 19697159 |
| nitrate assimilatory genes and their transcriptional regulation in a unicellular red alga cyanidioschyzon merolae: genetic evidence for nitrite reduction by a sulfite reductase-like enzyme. | cyanidioschyzon merolae is a unicellular red alga living in acid hot springs, which is able to grow on ammonium, as well as nitrate as sole nitrogen source. based on the complete genome sequence, proteins for nitrate utilization, nitrate transporter (nrt) and nitrate reductase (nr), were predicted to be encoded by the neighboring nuclear genes cmg018c and cmg019c, respectively, but no typical nitrite reductase (nir) gene was found by similarity searches. on the other hand, two candidate genes fo ... | 2010 | 20375110 |