| characterization of the str operon genes from spirulina platensis and their evolutionary relationship to those of other prokaryotes. | a 5.3 kb dna segment containing the str operon (ca. 4.5 kb) of the cyanobacterium spirulina platensis has been sequenced. the str operon includes the structural genes rpsl (ribosomal protein s12), rpsg (ribosomal protein s7), fus (translation elongation factor ef-g) and tuf (translation elongation factor ef-tu). from the nucleotide sequence of this operon, the primary structures of the four gene products have been derived and compared with the available corresponding structures from eubacteria, ... | 1989 | 2505055 |
| identification of two unknown reading frames in synechococcus 6301 as homologues of the 10k and 65k antigen genes of mycobacterium tuberculosis and related heat shock genes in e. coli and coxiella burnetii. | | 1989 | 2505234 |
| radioprotective effect of extract from spirulina platensis in mouse bone marrow cells studied by using the micronucleus test. | the radioprotective effect of an extract of spirulina platensis has been studied using the micronucleus test in polychromatic erythrocytes of bone marrow of mice. in this system the extract caused a significant reduction of the micronucleus frequencies induced by gamma-radiation. | 1989 | 2505406 |
| the biosynthesis of the chromophore of phycocyanin. pathway of reduction of biliverdin to phycocyanobilin. | the later stages in the pathway of biosynthesis of phycocyanobilin, the chromophore of phycocyanin, were studied by using radiolabelled intermediates. three possible pathways from biliverdin ix-alpha to phycocyanobilin were considered. 14c-labelled samples of key intermediates in two of the pathways, 3-vinyl-18-ethyl biliverdin ix-alpha and 3-ethyl-18-vinyl biliverdin ix-alpha, were synthesized chemically and were administered to cultures of cyanidium caldarium that were actively synthesizing ph ... | 1989 | 2505754 |
| purification and partial amino acid sequence of the glutamate 1-semialdehyde aminotransferase of barley and synechococcus. | glutamate-1-semialdehyde aminotransferase (e.c. 5.4.3.8) was purified from barley and the cyanobacteria synechococcus pcc 6301. the purification procedure involved serial affinity chromatography and preparative polyacrylamide gel electrophoresis under non-denaturing conditions. the aminotransferase of these two organisms showed different mobilities in non-denaturing gels. in sds-page the enzyme from both organisms migrated as a single protein with an apparent molecular weight of 46.000 da. an an ... | 1989 | 2505791 |
| structural and functional properties of the cyanobacterial photosystem i complex. | photosystem i (psi) complexes have been isolated from two cyanobacterial strains, synechococcus sp. pcc 7002 and 6301. these complexes contain six to seven low molecular mass subunits in addition to the two high molecular mass subunits previously shown to bind the primary reaction center components. chemical cross-linking of ferredoxin to the complex identified a 17.5-kda subunit as the ferredoxin-binding protein in the synechococcus sp. pcc 6301-psi complex. the amino acid sequence of this subu ... | 1989 | 2505837 |
| a simple method to preserve oceanic phytoplankton for flow cytometric analyses. | a simple method was developed to preserve marine phytoplankton populations so that delayed flow cytometric analyses could be performed. the method consisted of immediate fixation with 1% glutaraldehyde (final concentration) followed by storage in liquid nitrogen. the method was tested on individual algal species and on natural samples from both coastal and pelagic waters. in most cases, it caused little cell loss and preserved well both forward angle light scatter and chlorophyll fluorescence, b ... | 1989 | 2505987 |
| preparation and properties of a cross-linked complex between ferredoxin--nadp+ reductase and flavodoxin. | the electrostatically stabilized complex between anabaena variabilis ferredoxin--nadp+ reductase and azotobacter vinelandii flavodoxin has been covalently cross-linked by treatment with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. the covalent complex exhibits a molecular mass and fmn/fad content consistent with that expected for a 1:1 stoichiometry of the two flavoproteins. immunochemical cross-reactivity is exhibited by the covalent complex with rabbit antisera prepared separately against ea ... | 1989 | 2506011 |
| catechol stimulation of ferricyanide hill reaction by spheroplasts of cyanobacterium, synechococcus cedrorum: effect of temperature on catechol-stimulated oxygen evolution. | catechol(o-dihydroxybenzene) at low concentrations (20-100 microm) stimulates fecn-dependent o2 evolution of spheroplasts isolated from the cyanobacterium synechococcus both in the presence and absence of dbmib, an inhibitor of electron flow from psii to psi, the stimulation being two-fold with saturating concentration of (60 microm) catechol. catechol thus appears to mediate the acceptance of electrons at the reducing side of psii. similarly it may act on the component of electron donor to psii ... | 1989 | 2506124 |
| adaptive eradication of methionine and cysteine from cyanobacterial light-harvesting proteins. | sulphur is unique among the main elements of living cells in that it is covalently bound to biopolymers but does not occur in the biopolymer backbone. indeed, most of the bacterial sulphur content resides in the methionine and cysteine side-chains of proteins. the growth yield of an organism under conditions of sulphur limitation could therefore be greatly enhanced by mutations that substitute met and cys in the organism's proteins for sulphur-free amino acids. because the saving in sulphur woul ... | 1989 | 2506452 |
| the effects of single l-amino acid substitutions on the lethal potencies of the microcystins. | microcystin-lr and -la are more toxic than microcystin-ly and -rr in adult mice. they induce different degrees of thrombocytopenia and leukopenia, and the lethalities of their binary and ternary mixtures are addictive. postnatal mice are resistant to doses of microcystin-lr that are lethal to adults but they are susceptible to higher doses. substitution of a single l-amino acid for another in a microcystin markedly affects the dosimetric potency, but not the pathophysiology of its toxicity. | 1989 | 2506678 |
| production and characterization of antibodies against microcystins. | antibodies against a microcystin (mcyst) leucine-arginine variant (mcyst-lr) were demonstrated 4 weeks after immunization of rabbits with either mcyst-lr-polylysine- or mcyst-lr-ethylenediamine-modified bovine serum albumin. a radioimmunoassay (ria), a direct competitive enzyme-linked immunosorbent assay (elisa), and an indirect competitive elisa were developed for characterization of the antibodies. indirect elisa and ria revealed that mcyst-lr-ethylenediamine-bovine serum albumin was a better ... | 1989 | 2506810 |
| occurrence of the hepatotoxic cyanobacterium nodularia spumigena in the baltic sea and structure of the toxin. | water blooms formed by potentially toxic species of cyanobacteria are a common phenomenon in the baltic sea in late summer. twenty-five cyanobacterial bloom samples were collected from open and coastal waters of the baltic sea during 1985 to 1987, and their toxicity was determined by mouse bioassay. all of 5 bloom samples from the southern baltic sea, 6 of 6 from the open northern baltic sea (gulf of finland), and 7 of 14 finnish coastal samples were found to contain hepatotoxic cyanobacteria. n ... | 1989 | 2506812 |
| in vitro carotenogenesis and characterization of the phytoene desaturase reaction in anacystis. | an in vitro system for carotenogenesis has been developed from the cyanobacterium anacystis. precursor conversion is highly effective and almost no colored intermediates before beta-carotene accumulate. these cell-free reactions have been employed to characterize the phytoene desaturation reaction. phytoene desaturation is dependent on nad(p)+ and oxygen but insensitive to inhibitors of plant-type monooxygenases. this result suggests a hydride/proton transfer as mechanism for insertion of a doub ... | 1989 | 2506858 |
| evolutionary relationship of psba genes from cyanobacteria, cyanelles and plastids. | the psba gene is part of the reaction center of photosystem ii in cyanobacteria and the plastids of higher plants. its primary sequence is highly conserved among all species investigated so far and its sequence shows homologies with the l and m subunits of the reaction center of photosynthetic bacteria. we have analyzed the psba homolog from a eukaryotic alga, cyanophora paradoxa, where the gene is encoded on cyanelle dna. these cyanelles are surrounded by a murein sacculus and resemble cyanobac ... | 1989 | 2507175 |
| regulation of expression and nucleotide sequence of the anabaena variabilis reca gene. | the expression of the cyanobacterial reca gene, isolated from anabaena variabilis, has been examined at the levels of transcript and protein abundance. exposure of the cyanobacterium to a variety of dna-damaging agents, including mitomycin c, methyl methanesulfonate, and uv irradiation, results in a rapid increase in the abundance of the reca transcript above basal levels as determined by northern (rna) blot analysis. a concomitant increase in the abundance of a 37- to 38-kilodalton polypeptide ... | 1989 | 2507530 |
| transformation of a filamentous cyanobacterium by electroporation. | the filamentous cyanobacterium anabaena sp. strain m131 was transformed with the shuttle vector prl6 by electroporation. optimum conditions for electroporation required relatively high field strengths with short time constants. restriction significantly lowered the efficiency of transformation. a plasmid containing a single unmodified avaii restriction site transformed cells with about 100-fold-lower efficiency than did the same plasmid with a modified restriction site. | 1989 | 2507531 |
| molecular and genetical analysis of the fructose-glucose transport system in the cyanobacterium synechocystis pcc6803. | complementation for glucose transport capacity of deficient mutants from synechocystis pcc6803 allowed the cloning of the corresponding gene, glcp. the protein predicted from one open reading frame (orf) in the dna sequence was 468 residues long. it showed 46-60% amino acid sequence homology and similarity in size and predicted structure (including twelve probable membrane-spanning regions) with a group of non-phosphorylating sugar transporters from mammals, yeasts and escherichia coli. a second ... | 1989 | 2507869 |
| nucleotide sequence of the psbk gene of the cyanobacterium, anacystis nidulans 6301. | | 1989 | 2508063 |
| structure and toxicity of a peptide hepatotoxin from the cyanobacterium oscillatoria agardhii. | a peptide hepatotoxin was isolated by reversed phase liquid chromatography from the cyanobacterium oscillatoria agardhii and characterized structurally and toxicologically. amino acid analyses, proton nuclear magnetic resonance and fast atom bombardment mass spectrometry showed that the toxin is a cyclic heptapeptide (mol. wt 1023.5) with the structure cyclo-(ala-arg-asp-arg-adda-glu-n-methyldehydroala) (adda: 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid). in mice the toxic e ... | 1989 | 2508270 |
| characterization of chemically tritiated microcystin-lr and its distribution in mice. | chemically tritiated microcystin-lr (spec. act. 194 mci/mmol), purified to greater than 95% by c-18 reverse-phase high performance liquid chromatography, exhibited the same retention time and ultraviolet absorption profile as unlabeled toxin. acid-hydrolyzed [3h]-toxin yielded tritiated glutamate and beta-methylasparate. stability of the nonexchangeable [3h]-toxin in saline and urine was greater than 93% after 42 days stored at 22 degrees, 4 degrees or -20 degrees c. in blood, the breakdown of t ... | 1989 | 2508271 |
| spectroscopic studies of cyanobacterial phycobilisomes lacking core polypeptides. | synechococcus sp. pcc 7002 (agmenellum quadruplicatum pr6) genes encoding two highly conserved phycobilisome core polypeptides, a small linker polypeptide (lc8, apcc) and the allophycocyanin-b alpha-subunit (alpha apb, apcd), respectively, were interrupted by insertion of restriction fragments carrying the neomycin phosphotransferase gene of tn5. the interrupted genes were used to transform synechococcus sp. pcc 7002 to kanamycin resistance. the apcc- mutant assembled phycobilisomes lacking the ... | 1989 | 2508754 |
| effect of the effluent from a chlor-alkali factory on a blue-green alga: changes in the pigment content. | | 1989 | 2508800 |
| effects of three pesticides on msx-induced ammonia photoproduction by the cyanobacterium nostoc linckia. | three pesticides (2,4-d, basalin, aldrin) inhibited l-methionine-dl-sulfoximine (msx)-induced photoproduction of ammonia by the nitrogen-fixing cyanobacterium nostoc linckia. combinations of pesticides and msx were inhibitory except at low concentrations (100 and 500 micrograms/ml) of 2,4-d which stimulated nh+4 production. similar results were obtained when pesticides were added 6 hr after the addition of msx, but the inhibition was weaker. when msx was added to the culture 6 hr after the addit ... | 1989 | 2509191 |
| physical and genetic maps of the genome of the heterocyst-forming cyanobacterium anabaena sp. strain pcc 7120. | a restriction map of the chromosome of the cyanobacterium anabaena sp. strain pcc 7120 was generated by the determination of the order of restriction fragments of the infrequently cleaving restriction endonucleases avrii, sali, and psti. these restriction fragments were resolved by the pulsed homogeneous orthogonal field gel electrophoresis system of pulsed-field gel electrophoresis (i. bancroft and c. p. wolk, nucleic acids res. 16:7405-7418, 1988). other infrequently cutting restriction endonu ... | 1989 | 2509424 |
| the 5'-flanking region of the gene encoding the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase is crucial for growth of the cyanobacterium synechococcus sp. strain pcc 7942 at the level of co2 in air. | transformation of the high-co2-requiring mutants (hcr) o221 and e1 derived from the cyanobacterium synechococcus sp. strain pcc 7942 by a wild-type dna library restored their ability to grow at the level of co2 in air. a plasmid (pe12) containing a 10-kilobase dna insert was rescued from a o221 heterogenote and proved to transform both o221 and e1 to the wild-type phenotype. the capacity of the pe12 subclones to confer the wild-type phenotype to o221 transformants enabled the mapping of the muta ... | 1989 | 2509426 |
| photosynthetic co2 fixation and ribulose bisphosphate carboxylase/oxygenase activity of nostoc sp. strain ucd 7801 in symbiotic association with anthoceros punctatus. | the cyanobacterium nostoc sp. strain ucd 7801, immediately after separation from pure cultures of a reconstituted symbiotic association with the bryophyte anthoceros punctatus, exhibited a rate of light-dependent co2 fixation that was eightfold lower than that measured in the free-living growth state. ribulose bisphosphate carboxylase/oxygenase (rubpc/o) specific activity was also eightfold lower in cell extracts of symbiotic strain 7801 relative to that in free-living cultures. the in vitro act ... | 1989 | 2509431 |
| some properties and amino acid sequence of plastocyanin from a green alga, ulva arasakii. | plastocyanin was purified from a multicellular, marine green alga, ulva arasakii, by conventional methods to homogeneity. the oxidized plastocyanin showed absorption maxima at 252, 276.8, 460, 595.3, and 775 nm, and shoulders at 259, 265, 269, and 282.5 nm; the ratio a276.8/a595.3 was 1.5. the midpoint redox potential was determined to be 0.356 v at ph 7.0 with a ferri- and ferrocyanide system. the molecular weight was estimated to be 10,200 and 11,000 by sds-page and by gel filtration, respecti ... | 1989 | 2509442 |
| structure and targeted mutagenesis of the gene encoding 8-kda subunit of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | photosystem i reaction center of the cyanobacterium synechocystis sp. pcc 6803 contains seven different polypeptide subunits. the subunit with a molecular mass of about 8 kda was isolated, and the sequence of its amino-terminal residues was determined. oligonucleotide probes corresponding to this sequence were used to isolate the gene encoding this subunit. the gene, termed as psae, codes for a polypeptide with a mass of 8075 da. it is present as a single copy in the genome and is transcribed as ... | 1989 | 2509456 |
| insertional inactivation of the gene encoding subunit ii of photosystem i from the cyanobacterium synechocystis sp. pcc 6803. | the cyanobacterium synechocystis sp. pcc 6803 carries out oxygenic photosynthesis analogous to higher plants. its photosystem i contains seven different polypeptide subunits. the cartridge mutagenesis technique was used to inactivate the psad gene which encodes subunit ii of photosystem i. a mutant strain lacking subunit ii was generated by transforming wild type cells with cloned dna in which psad gene was interrupted by a gene conferring kanamycin resistance. the photoautotrophic growth of mut ... | 1989 | 2509457 |
| toxicity of intraperitoneal doses of microcystin-lr in two strains of male mice. | male balb/c and swiss webster (sw) mice were administered various i.p. doses of microcystin-lr (mclr) to establish dose-response curves and to determine if a sublethal dose of mclr would protect against an approximate ld100 min given 2 or 3 days later. micocystin-lr has an extremely steep dose-lethal response curve in bc mice--ld50 = 32.5 micrograms (micrograms)/kg, approximate ld0 max = 25 micrograms/kg and approximate ld100 min = 40 micrograms/kg. liver weights increased 64% (bc) and 51% (sw) ... | 1989 | 2509678 |
| chemicals halt growth of aids. | | 1989 | 2510105 |
| poisoning at rutland water. | | 1989 | 2510394 |
| directed alteration of the d1 polypeptide of photosystem ii: evidence that tyrosine-161 is the redox component, z, connecting the oxygen-evolving complex to the primary electron donor, p680. | in photosystem ii, electrons are sequentially extracted from water at a site containing mn atoms and transferred through an intermediate carrier (z) to the photooxidized reaction-center chlorophyll (p680+). two polypeptides, d1 and d2, coordinate the primary photoreactants of the reaction center. recently debus et al. [debus, r.j., barry, b.a., babcock, g.t., & mcintosh, l. (1988) proc. natl. acad. sci. u.s.a. 85, 427-430], have suggested that z is a tyrosine residue located at position 161 of t ... | 1989 | 2510819 |
| delta-aminolevulinic acid biosynthesis in escherichia coli and bacillus subtilis involves formation of glutamyl-trna. | cell-free extracts of escherichia coli and bacillus subtilis catalyzed the trna-dependent, rnase a-sensitive formation of delta-aminolevulinic acid (ala) from glutamate. cell extracts prepared from cultures of e. coli grown under aerobic or anaerobic conditions had similar levels of ala biosynthetic activity. both the trna-stimulated conversion of glutamate to ala and the conversion of glutamate-1-semialdehyde to ala were inhibited by gabaculin. however, gabaculin had no effect on the growth of ... | 1989 | 2511063 |
| duplication of the phycocyanin operon in the unicellular cyanobacterium anacystis nidulans r2. | two phycocyanin (pc) operons, each containing alpha- and beta-subunit genes, have been isolated from the unicellular cyanobacterium anacystis nidulans r2. using oligodeoxyribonucleotide probes for the pc-coding regions, three psti fragments were obtained and shown to contain the two operons, which are 2.7 kb apart, with a proposed gene order of 5'-(beta i-alpha i)-(beta ii-alpha ii)-3'. the nucleotide sequences of both alpha-subunit genes are identical, as are the beta-sequences and the 51-bp in ... | 1989 | 2511077 |
| determination of anatoxin-a, the neurotoxin of anabaena flos-aquae cyanobacterium, in algae and water by gas chromatography-mass spectrometry. | | 1989 | 2512321 |
| protein phosphorylation and control of excitation energy transfer in photosynthetic purple bacteria and cyanobacteria. | the function of phosphorylation of light-harvesting polypeptides is well characterised in chloroplasts of green plants, but the prokaryotic cyanobacteria and purple photosynthetic bacteria have quite different light-harvesting polypeptides whose structure and function cannot be controlled in precisely the same way. nevertheless, cyanobacteria show light-dependent phosphorylation of membrane polypeptides associated with photosystem ii and with the light-harvesting phycobilisome, and purple bacter ... | 1989 | 2512993 |
| optimum conditions for growth of cyanobacteria on solid media. | the colony forming ability of single cells or very short filaments of 7 strains of cyanobacteria was tested on media solidified by agar or by agar substitutes (gel gro or gel rite). in addition, the effect of various methods for preparation of agar media on colony forming ability was measured. high efficiency colony formation for most of the strains required that the agar be autoclaved separately from the salts in the medium. the addition of thiosulfate, but not buffer, significantly increased t ... | 1989 | 2513249 |
| interaction of microcystin-lr with superchar: water decontamination and therapy. | activated charcoal (superchar) has been recommended for therapeutic use against poisoning by several toxic agents, but it has not been tested against microcystin-lr toxicosis. microcystin-lr, a cyclic heptapeptide isolated from fresh water blue-green algae, has been shown to be a potent hepatotoxin in animals and in man. studies were performed to determine the degree of in vitro adsorption of microcystin-lr to superchar and to assess the efficacy of superchar as a therapeutic agent against micro ... | 1989 | 2513418 |
| nucleotide sequence of the gene proposed to encode the small subunit of the soluble hydrogenase of the thermophilic unicellular cyanobacterium synechococcus pcc 6716. | | 1989 | 2513553 |
| use of degenerate oligonucleotides for amplification of the nifh gene from the marine cyanobacterium trichodesmium thiebautii. | trichodesmium spp. are marine filamentous, nonheterocystous, nitrogen-fixing cyanobacteria which are an important component of marine ecosystems. this organism has never been maintained in axenic culture, and there has remained some doubt as to the identity of the organism responsible for nitrogen fixation in trichodesmium aggregates. by using degenerate oligonucleotide primers, it has been possible to amplify, clone, and sequence a segment of the nifh gene from a natural assemblage of trichodes ... | 1989 | 2513774 |
| gas vesicle proteins. | | 1989 | 2513809 |
| a mössbauer analysis of the low-potential iron-sulfur center in photosystem i: spectroscopic evidence that fx is a [4fe-4s] cluster. | we report the results of a mössbauer study of the low-potential iron-sulfur cluster fx in the photosystem i core protein of synechococcus 6301. the mössbauer spectrum of fx in the oxidized state shows an isomer shift of 0.42 mm/s, which is in good agreement with the 0.43 mm/s isomer shift found in [4fe-4s] proteins but not with the isomer shift of 0.26 mm/s found in [2fe-2s] proteins. in the reduced state the spectrum is asymmetrically broadened at 80 k, indicating the presence of two very close ... | 1989 | 2513883 |
| molecular evolution of the small subunit of ribulose bisphosphate carboxylase: nucleotide substitution and gene conversion. | the nucleotide sequences encoding the mature portion of 31 ribulose 1.5-bisphosphate carboxylase small subunit (ssu) genes from 17 genera of plants, green algae and cyanobacteria were examined. among the 465 pairwise sequence comparisons, ssu multigene family members within the same species were more similar to each other in nonsynonymous or replacement nucleotide substitutions (rns) than they were to ssu sequences in any other organism. the concerted evolution of independent ssu gene lineages w ... | 1989 | 2515110 |
| a promoter-probe vector-host system for the cyanobacterium, synechocystis pcc6803. | a vector-host system for testing promoters in the cyanobacterium synechocystis pcc6803 has been constructed. it relies on a small escherichia coli promoter-probe plasmid, pff11, which has four unique restriction sites in a polylinker upstream from the cat reporter gene. this plasmid is able to obtain a cyanobacterial origin of replication by homologous recombination with the resident plasmid of the recipient host, generating a new e. coli-synechocystis pcc6803 shuttle vector. this plasmid does n ... | 1989 | 2515116 |
| evolution of antioxidant mechanisms: thiol-dependent peroxidases and thioltransferase among procaryotes. | glutathione peroxidase and glutathione s-transferase both utilize glutathione (gsh) to destroy organic hydroperoxides, and these enzymes are thought to serve an antioxidant function in mammalian cells by catalyzing the destruction of lipid hydroperoxides. only two groups of procaryotes, the purple bacteria and the cyanobacteria, produce gsh, and we show in the present work that representatives from these two groups (escherichia coli, beneckea alginolytica, rhodospirillum rubrum, chromatium vinos ... | 1989 | 2515292 |
| [cloning the alpha-amylase gene of bacillus amyloliquefaciens in cyanobacteria cells]. | the recombinant plasmids of piah4amy series were constructed containing the alpha-amylase gene of bacillus amyloliquefaciens a50 with its own promoter and leading sequence within an integrative vector plasmid piah4 (cmr) for cyanobacterium anacystis nidulans r2. at anacystis nidulans transformation the hybrid plasmids integrate into cyanobacterium chromosome with high efficiency and all cmr transformants produce alpha-amylase. expression of bacillar alpha-amylase gene in cyanobacterium cells is ... | 1989 | 2515431 |
| expression of an anacystis nidulans photolyase gene in escherichia coli; functional complementation and modified action spectrum of photoreactivation. | the anacystis nidulans photolyase gene inserted in an expression vector plasmid was introduced into escherichia coli cells and the production of anacystis photolyase protein was confirmed by reaction with antibodies raised against photolyase purified from a. nidulans cells. the anacystis photolyase functioned in photoreactivation repair defective e. coli cells. the e. coli transformants exhibited an action spectrum with a maximum around 380 nm similar to that of e. coli photolyase in contrast wi ... | 1989 | 2516329 |
| evaluation of automated threshold selection methods for accurately sizing microscopic fluorescent cells by image analysis. | the accurate measurement of bacterial and protistan cell biomass is necessary for understanding their population and trophic dynamics in nature. direct measurement of fluorescently stained cells is often the method of choice. the tedium of making such measurements visually on the large numbers of cells required has prompted the use of automatic image analysis for this purpose. accurate measurements by image analysis require an accurate, reliable method of segmenting the image, that is, distingui ... | 1989 | 2516431 |
| glycosidase inhibitors from algae. | | 1989 | 2516818 |
| characteristics of the methylammonium/ammonium transport systems of the nitrogen-fixing cyanobacterium anabaena 7120 (atcc 27893). | nh4(+)-transport in anabaena 7120 was studied using the nh4+ analogue, 14ch3nh3+. at ph 7, two energy-dependent nh4(+)-transport systems were detected in both n2- and no3(-)-grown cells, but none in nh4(+)-grown cells. both transport systems showed a low and a high affinity mode of operation depending on the substrate concentration. one of the transport systems showed km values of 8 microm (vmax = 1 nmole min-1mg-1protein) and 80 microm (vmax = 7 nmole min-1mg-1protein), and was insensitive to l ... | 1989 | 2516834 |
| a new procedure for the analysis and purification of naturally occurring anatoxin-a from the blue-green alga anabaena flos-aquae. | anabaena flos-aquae produces at least two neurotoxins termed anatoxin-a (antx-a) and -a(s) [antx-a(s)]. antx-a is a potent postsynaptic depolarizing neuromuscular blocking agent. its structure is the secondary amine, 2-acetyl-9-azabicyclo[4.2.1]non-2-ene. known isolation and analysis methods have not always given satisfactory results. therefore, an improved procedure was developed for both isolation and analysis of antx-a which involves four steps; extraction, clean-up, separation and determinat ... | 1989 | 2516923 |
| [poisonings by blue-green algae]. | | 1989 | 2517137 |
| cobalt-induced inhibition of growth in cyanobacteria anabaena doliolum and anacystis nidulans: interaction with sulphur containing amino acids. | cobalt, above 1 microm concentration was growth inhibitory for both a. doliolum and a. nidulans. its toxicity was mitigated by sulphur containing amino acids (cystine and cysteine), however, methionine could not mitigate the cobalt toxicity at all. | 1989 | 2517422 |
| effect of anatoxin-a(s) from anabaena flos-aquae nrc-525-17 on blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity in rats. | the effects of anatoxin-a(s) [antx-a(s)] from the cyanobacterium anabaena flos-aquae nrc-525-17 on mean arterial blood pressure, heart rate, respiratory rate, tidal volume, minute volume, and phrenic nerve activity were evaluated in anesthetized sprague-dawley rats. anatoxin-a(s) was administered by continuous intravenous infusion. the initial effect of the toxin was to slow the heart rate and reduce arterial blood pressure, followed by much more pronounced reductions in these parameters. the ma ... | 1989 | 2517795 |
| toxicity of chromium and tin to anabaena doliolum. interaction with sulphur-containing amino acids and thiols. | toxicity of chromium and tin on growth, heterocyst differentiation, nitrogenase activity and 14co2 uptake of anabaena doliolum and its amelioration by sulphur-containing amino acids and thiols has been studied. the final growth yield was found to be approximately 51% and 58% of control at sublethal concentration of chromium and tin respectively. among various amino acids tested, cysteine (0.05 mm) significantly restored growth, heterocyst differentiation, nitrogenase and 14co2 uptake of test alg ... | 1989 | 2518521 |
| diagnostic and clinically important aspects of cyanobacterial (blue-green algae) toxicoses. | | 1989 | 2518710 |
| [teratogenic study of spirulina in rats]. | the algae spirulina has been considered for use as a supplementary protein to feed and food. any form of single cell protein destined to this purpose should be previously subjected to detailed toxicological investigations in animals or another experimental models. the present study was therefore designed to determine the teratogenic potential of spirulina in rats. the algae was administered in the diet at the levels of 0, 10, 20 and 30 g/100 g on days 7-14, 1-14 and 1-21 of gestation. the dams w ... | 1989 | 2518788 |
| mutations responsible for high light sensitivity in an atrazine-resistant mutant of synechocystis 6714. | the primary target of photoinhibition is the photosystem ii reaction center. the process involves a reversible damage, followed by an irreversible inhibition of photosystem ii activity. during cell exposition to high light intensity, the d1 protein is specially degraded. an atrazine-resistant mutant of synechocystis 6714, azv, reaches the irreversible step of photoinhibition faster than wild-type cells. two point mutations present in the psba gene of azv (coding for d1) lead to the modification ... | 1989 | 2518832 |
| nucleotide sequence of the gene encoding the 33 kda water oxidizing polypeptide in anabaena sp. strain pcc 7120 and its expression in escherichia coli. | the 33 kda extrinsic polypeptide of photosystem ii, also known as the manganese-stabilizing polypeptide (msp), is located on the lumen side of the thylakoid and is involved in water oxidation. the gene for msp, designated woxa, has been cloned from the nitrogen-fixing filamentous cyanobacterium anabaena and sequenced. the woxa open reading frame was found to be 819 bp. the deduced amino acid sequence was 63% and 59% homologous with that of synechococcus and synechocystis, respectively, and 44% c ... | 1989 | 2518833 |
| molecular analysis of psba mutations responsible for various herbicide resistance phenotypes in synechocystis 6714. | mutations conferring herbicide resistance in 3 mutant strains of the cyanobacterium synechocystis 6714 have been characterized by gene cloning and sequencing. the mutants display very different phenotypes: dcmu-iia is dcmu-resistant and atrazine-resistant, dcmu-iib is dcmu-resistant and atrazine-sensitive, and az-v is dcmu-sensitive, atrazine-resistant and presents particular photoinhibition properties. these mutants were originally obtained either by one-step selection (dcmu-iia) or by two-step ... | 1989 | 2518834 |
| influence of light on accumulation of photosynthesis-specific transcripts in the cyanobacterium synechocystis 6803. | transcript accumulation for the psba, psbd, psbd-c, rbcl-s and rrn genes in synechocystis 6803 was followed under different light conditions. psba, psbd, psbd-c and rbcl-s transcripts required light to accumulate and the relative abundance of these transcripts differed between high and low light conditions. under high light conditions, steady-state levels of psba, psbd and psbd-c transcripts were higher while levels of rbcl-s transcripts were lower than under low light conditions. rrn transcript ... | 1989 | 2518835 |
| wide distribution of homologs of escherichia coli kdp k+-atpase among gram-negative bacteria. | we used southern blotting to screen a variety of bacterial genes for homology to the kdp genes of escherichia coli, genes that encode an atp-driven k+ transport system. we found that most enterobacteria have sequences homologous to those of the three kdp structural genes and the kdpd regulatory gene. a number of distantly related species, including some cyanobacteria, have sequences homologous to those of the structural genes but not the regulatory gene. in all cases only a single region of homo ... | 1989 | 2521620 |
| cloning and expression of the branching enzyme gene (glgb) from the cyanobacterium synechococcus sp. pcc7942 in escherichia coli. | using the glgb gene from escherichia coli as a hybridization probe, the gene encoding the branching enzyme of the cyanobacterium synechococcus sp. pcc7942 has been identified on a 3.9-kb psti fragment which was cloned into plasmid puc9. two types of plasmids have been isolated. plasmid pkvn1 was expressing the synechococcus sp. gene as was shown by complementation of the glgb mutation of e. coli kv832. plasmid pkvn2, which carried the same insert in the opposite orientation was unable to complem ... | 1989 | 2527779 |
| nostoc commune utex 584 gene expressing indole phosphate hydrolase activity in escherichia coli. | a gene encoding an enzyme capable of hydrolyzing indole phosphate was isolated from a recombinant gene library of nostoc commune utex 584 dna in lambda gt10. the gene (designated iph) is located on a 2.9-kilobase ecori restriction fragment and is present in a single copy in the genome of n. commune utex 584. the iph gene was expressed when the purified 2.9-kilobase dna fragment, free of any vector sequences, was added to a cell-free coupled transcription-translation system. a polypeptide with an ... | 1989 | 2536677 |
| purification of an acidic plastocyanin from microcystis aeruginosa. | plastocyanin and cytochrome c-553 are two functionally equivalent electron carriers in the photosynthetic chain of cyanobacteria. microcystis aeruginosa, a unicellular cyanobacterium which grows well at a high ph (8.6) and which was not known to possess plastocyanin, has been studied for its ability to synthesize plastocyanin in culture media with and without cu. in the absence of cu, an acidic cytochrome c-553 alone was isolated. with the inclusion of 2 microm cu, cytochrome c-553 synthesis was ... | 1989 | 2537099 |
| purification and properties of the intact p-700 and fx-containing photosystem i core protein. | the intact photosystem i core protein, containing the psaa and psab polypeptides, and electron transfer components p-700 through fx, was isolated from cyanobacterial and higher plant photosystem i complexes with chaotropic agents followed by sucrose density ultracentrifugation. the concentrations of naclo4, nascn, nai, nabr or urea required for the functional removal of the 8.9 kda, fa/fb polypeptide was shown to be inversely related to the strength of the chaotrope. the photosystem i core prote ... | 1989 | 2537101 |
| a region of a cyanobacterial genome required for sulfate transport. | using the cysa locus of salmonella typhimurium as a heterologous probe, we have cloned a region of the anacystis nidulans r2 (synechococcus pcc 7942) genome involved in sulfate assimilation. the 8.3-kilobase-pair region encodes at least five transcripts that cannot be detected unless the cells are deprived of sulfur. one of the genes in this region has been sequenced, and the protein that it encodes is homologous to a polypeptide component of other permease systems of escherichia coli and salmon ... | 1989 | 2538823 |
| the amino acid sequence of cytochrome c553 from microcystis aeruginosa. | cytochrome c553 is an electron donor to p700 in the photosynthetic electron transfer chain of cyanobacteria and eukaryotic algae. we have purified this cytochrome from the cyanobacterium microcystis aeruginosa and determined its amino acid sequence. when the amino acid sequence of this protein is compared to sequences of cytochromes c553 from other organisms, one sees that the evolution of net charge is more pronounced than the evolution of overall structure, further documenting a pronounced shi ... | 1989 | 2539045 |
| characterization of the cytochrome c oxidase in isolated and purified plasma membranes from the cyanobacterium anacystis nidulans. | functionally intact plasma membranes were isolated from the cyanobacterium (blue-green alga) anacystis nidulans through french pressure cell extrusion of lysozyme/edta-treated cells, separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation, and purified by repeated recentrifugation. origin and identity of the chlorophyll-free plasma membrane fraction were confirmed by labeling of intact cells with impermeant protein markers, [35s]diazobenzenesulfonate and fluor ... | 1989 | 2545245 |
| phosphomonoesterase activity of the cyanobacterium (blue-green alga) calothrix parietina. | cellular and extracellular phosphomonoesterase activities were compared in calothrix parietina d550, a strain whose original environment has been studied in detail. activity in both fractions became detectable at about the same stage in batch culture. differences in the influence of environmental factors between the two were slight, suggesting a common origin. the optimum temperatures for cellular and extracellular activities were 40 degrees c and 30 degrees c, respectively, and the upper limits ... | 1989 | 2549342 |
| partial amino acid sequence of fructose-1,6-bisphosphatase from the blue-green algae synechococcus leopoliensis. | purified fructose-1,6-bisphosphatase from the cyanobacterium synechococcus leopoliensis was s-carboxymethylated and cleaved with trypsin. the resulting peptides were purified by reversed-phase high performance liquid chromatography and the amino acid sequence of six of the purified peptides was determined by gas-phase microsequencing. the results revealed sequence homology with other fructose-1,6-bisphosphatases. the obtained sequence data provides information required for the design of oligonuc ... | 1989 | 2550924 |
| calmodulin in heterocystous cyanobacteria: biochemical and immunological evidence. | the occurrence activity and localization of calmodulin in three heterocystous cyanobacteria of the genus anabaena were studied. boiled crude extracts caused a ca2+-dependent stimulation of nad kinase. such a stimulation was blocked by egta and chlorpromazine, sds-page and western blot analysis using antiserum against eukaryotic spinach calmodulin, revealed a polypeptide of about 17 kda. immunogold localization of calmodulin gave a dense gold label in both vegetative cells and heterocysts. the la ... | 1989 | 2551772 |
| tn5 mutagenesis of anabaena sp. strain pcc 7120: isolation of a new mutant unable to grow without combined nitrogen. | methylation by ava methylases in escherichia coli increases the efficiency to transfer of tn5 in pbr322bla:: tn5 from e. coli to anabaena sp. strain pcc 7120 by conjugation. following conjugation, tn5 but not pbr322 sequences were found at many different positions in the anabaena chromosome. this procedure was used to mutagenize, tag, and clone a previously unrecognized gene required for nitrogen fixation in this anabaena sp. | 1989 | 2551892 |
| biosynthesis of 130-kilodalton mosquito larvicide in the cyanobacterium agmenellum quadruplicatum pr-6. | the 130-kilodalton mosquito larvicidal gene, cloned from bacillus thuringiensis var. israelensis, was introduced into the cyanobacterium agmenellum quadruplicatum pr-6 by plasmid transformation. transformed cells synthesized 130-kilodalton delta-endotoxin protein and showed mosquito larvicidal activity. results demonstrate a potential use of a cyanobacterium for biological control of mosquitoes. | 1989 | 2552921 |
| characterization of an insertion sequence (is891) of novel structure from the cyanobacterium anabaena sp. strain m-131. | when recombinant plasmids that were transferred to the cyanobacterium anabaena sp. strain m-131 were transferred back to escherichia coli, some of the transformants contained inserts. one of the insertion sequences (iss) was characterized by sequencing. this 1,351-base-pair is contained an open reading frame that was capable of encoding a peptide of 310 amino acids and had terminal sequences with distinctive structures, but it lacked terminal inverted repeats and did not duplicate target dna upo ... | 1989 | 2553665 |
| nitrogen fixation (nif) genes of the cyanobacterium anabaena species strain pcc 7120. the nifb-fdxn-nifs-nifu operon. | a second nitrogen fixation (nif) operon in the cyanobacterium (blue-green alga) anabaena (nostoc) sp. strain pcc 7120 has been identified and sequenced. it is located just upstream of the nifhdk operon and consists of four genes in the order nifb, fdxn, nifs, and nifu. the three nif genes were identified on the basis of their similarity with the corresponding genes from other diazotrophs. the fourth gene, fdxn, codes for a bacterial type ferredoxin (mulligan, m. e., buikema, w. j., and haselkorn ... | 1989 | 2553733 |
| cloning and sequencing of the fbcf, b and c genes encoding the cytochrome b/c1 complex from rhodopseudomonas viridis. | the complete nucleotide sequence of the genes encoding the rieske fes, the cytochrome b and the cytochrome c1 subunits of the ubiquinol-cytochrome c2 oxidoreductase from the photosynthetic purple bacterium rhodopseudomonas viridis, and the derived amino acid sequences are presented. these three genes, fbcf, fbcb and fbcc, are located at contiguous sites of the genome. the dna-deduced amino acid sequences are compared with known primary structures of corresponding proteins from other purple photo ... | 1989 | 2560136 |
| genetic relationship of two highly studied synechococcus strains designated anacystis nidulans. | the cyanobacteria synechococcus sp. strain pcc 7942 and synechococcus sp. strain pcc 6301 are very closely related and both have been designated by the binomial anacystis nidulans. the only established difference between the two strains is the superior transformation properties of strain pcc 7942. significant homology between the rrna genes of these strains was demonstrated by the ability of an rrna operon from strain pcc 6301, interrupted by a spectinomycin and streptomycin resistance marker, t ... | 1989 | 2563363 |
| purification and properties of glutamine synthetase from the non-n2-fixing cyanobacterium phormidium laminosum. | soluble glutamine synthetase activity (l-glutamate:ammonia ligase, adp forming, ec 6.3.1.2) was purified to electrophoretic homogeneity from the filamentous non-n2-fixing cyanobacterium phormidium laminosum (oh-1-p.cl1) by using conventional purification procedures in the absence of stabilizing ligands. the pure enzyme showed a specific activity of 152 mumol of gamma-glutamylhydroxamate formed.min-1 (transferase activity), which corresponded to 4.4 mumol of pi released.min-1 (biosynthetic activi ... | 1989 | 2563365 |
| impact of chromium and tin on a nitrogen-fixing cyanobacterium anabaena doliolum: interaction with bivalent cations. | the toxicity of chromium and tin on growth, uptake of no3- and nh4+, nitrate reductase and glutamine synthetase activity of anabaena doliolum, and its interaction with bivalent cations, viz. ca2+, mg2+, mn2+, ni2+, co2+, and zn2+, has been studied. some interacting cations, viz. ca, mg, and mn, substantially antagonized the toxic effects of chromium and tin with reference to growth and nutrient (no3- and nh4+) uptake in the hierarchical sequence ca greater than mg greater than mn, whereas the se ... | 1989 | 2565805 |
| comparison of dna restriction fragment length polymorphisms of nostoc strains in and from cycads. | dna was prepared from cyanobacteria freshly isolated from coralloid roots of natural populations of five cycad species: ceratozamia mexicana mexicana (mexico), c. mexicana robusta (mexico), dioon spinulosum (mexico), zamia furfuraceae (mexico) and z. skinneri (costa rica). using the southern blot technique and cloned anabaena pcc 7120 nifk and glna genes as probes, restriction fragment length polymorphisms of these cyanobacterial symbionts were compared. the five cyanobacterial preparations show ... | 1989 | 2569858 |
| a novel ubiquitous protein 'chaperonin' supports the endosymbiotic origin of mitochondrion and plant chloroplast. | the deduced amino acid sequences for a major mitochondrial protein (designated p1, related to the 'chaperonin' family of proteins) from human and chinese hamster cells show extensive similarity (greater than 60% identity observed over the entire length) with a related protein present in evolutionarily as divergent organisms as escherichia coli, coxiella burnetii, mycobacterium species, cyanobacteria as well as in yeast mitochondria and higher plant chloroplasts. of the different groups of bacter ... | 1989 | 2571331 |
| ammonia assimilating enzymes from cyanobacteria: in situ and in vitro assay using high-performance liquid chromatography. | assay systems for ammonia assimilating enzymes in cyanobacteria are reported. glutamine synthetase, glutamate synthase, and glutamate dehydrogenase can be easily assayed in situ, after the cells are made permeable to the reagents, or in vitro. the method is based upon the quantitation of glutamine or glutamate after the separation, when needed, of their o-phthaldialdehyde derivatives by reverse-phase high-performance liquid chromatography on a c18 column. the isocratic elution and the fluorometr ... | 1989 | 2573289 |
| protective effects of certain natural and synthetic complexans on the toxicity of chromium and tin to a n2-fixing cyanobacterium, anabaena doliolum. | the effects of chromium and tin on survival, growth, carbon fixation, nitrate reduction, ammonia assimilation, and nitrogenase activity of a n2-fixing cyanobacterium. anabaena doliolum, and their amelioration by synthetic and natural complexans, viz., edta, nitrilotriacetic acid (nta), pyridine dicarboxylic acid (pda), and citrate, have been studied. chromium proved to be much more toxic than tin, as it inhibited growth yield (49%), carbon fixation (53%), and nitrate reductase (79%), glutamine s ... | 1989 | 2575394 |
| the genes of both subunits of ribulose-1,5-bisphosphate carboxylase constitute an operon on the plastome of a red alga. | plastid (pt) dna from the red alga porphyridium aerugineum was purified by cscl gradient centrifugation. an ecori library of the ptdna was screened with a gene probe specific for the gene encoding the large subunit (lsu) of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco ec 4.1.1.39) from spinach. a 5.8 kb ecori clone containing the lsu gene (rbcl) was isolated and the dna sequence of the porphyridium rbcl gene and its flanking regions was determined. an open reading frame was found 130 ... | 1989 | 2598276 |
| psba genes indicate common ancestry of prochlorophytes and chloroplasts. | it has long been suspected that chloroplasts evolved after an endosymbiotic event involving a photosynthetic prokaryote, presumably a cyanobacterium, and a eukaryotic organism. recent studies have provided strong evidence about the cyanobacterial nature of chloroplasts. since the discovery of prochlorophytes, oxygen-evolving photosynthetic prokaryotes containing chlorophyll a and chlorophyll b and lacking phycobiliproteins, there has been speculation that these represent evolutionary intermediat ... | 1989 | 2643058 |
| amplified expression of ribulose bisphosphate carboxylase/oxygenase in pbr322-transformants of anacystis nidulans. | prior research suggested that the genes for large (l) and small (s) subunits of ribulose bisphosphate carboxylase/oxygenase (rubisco) are amplified in ampicillin-resistant pbr322-transformants of anacystis nidulans 6301. we now report that chromosomal dna from either untransformed or transformed a. nidulans cells hybridizes with nick-translated [32p]-pbr322 at moderately high stringency. moreover, nick-translated [32-p]-pcs75, which is a puc9 derivative containing a psti insert with l and s subu ... | 1989 | 2644909 |
| absence of a bicarbonate-depletion effect in electron transfer between quinones in chromatophores and reaction centers of rhodobacter sphaeroides. | higher plants, algae, and cyanobacteria are known to require bicarbonate ions for electron flow from the first stable electron acceptor quinone qa to the second electron acceptor quinone qb, and to the intersystem quinone pool. it has been suggested that in photosystem ii of oxygenic photosynthesis, bicarbonate ion functions to maintain the reaction center in a proper conformation and, perhaps, to provide the protons needed to stabilize the semiquinone (qb-). in this paper, we show that bicarbon ... | 1989 | 2647143 |
| the evolutionary origins of organelles. | analysis of organellar genomes strongly supports the idea that chloroplasts and mitochondria originated in evolution as eubacteria-like endosymbionts, whose closest contemporaries are cyanobacteria and purple photosynthetic bacteria, respectively. however, there is still much debate about whether a single endosymbiotic event or multiple ones gave rise to each organelle in different eukaryotes, and considerable uncertainty about what has happened to the genomes of chloroplasts and mitochondria si ... | 1989 | 2686121 |
| expressed genes for plant-type ribulose 1,5-bisphosphate carboxylase/oxygenase in the photosynthetic bacterium chromatium vinosum, which possesses two complete sets of the genes. | two sets of genes for the large and small subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase (rubisco) were detected in the photosynthetic purple sulfur bacterium chromatium vinosum by hybridization analysis with rubisco gene probes, cloned by using the lambda fix vector, and designated rbcl-rbcs and rbca-rbcb. rbcl and rbca encode the large subunits, and rbcs and rbcb encode the small subunits. rbcl-rbcs was the same as that reported previously (a. m. viale, h. kobayashi, t. takabe, an ... | 1989 | 2708310 |
| evaluation of the metal uptake of several algae strains in a multicomponent matrix utilizing inductively coupled plasma emission spectrometry. | three freshwater heat-killed, lyophilized blue-green algae strains have been characterized as to their ability to accumulate heavy metals with a focus on the utilization of these algae as an analytical preconcentration technique. this study examines the metal uptake in several multicomponent mixtures by using inductively coupled plasma optical emission spectrometry (icp-oes). six milligrams of a pure strain of algae was added to 20-ml aliquots of buffered (ph 5.5-6.5) multielement solutions cont ... | 1989 | 2729595 |
| the distribution of lipids and sterols in cell types from the marine sponge pseudaxinyssa sp. | the sponge pseudaxinyssa sp., unique in sterol and fatty acid composition, was cellularly dissected into fractions enriched in each of the major cell types present in the sponge: microbial symbionts (cyanobacteria), small sponge cells (pinacocytes and choanocytes), and large sponge cells (archeocytes and cyanophytes). three phototrophic microbial symbionts were also isolated from the cell fractions and grown in culture. an unsymmetrical distribution of fatty acids and sterols was observed for th ... | 1989 | 2761353 |
| shipboard analytical flow cytometry of oceanic ultraphytoplankton. | shipboard analysis of marine ultraphytoplankton by flow cytometry is a powerful method to classify these cells according to in vivo fluorescence characteristics and size. at present, this ataxonomic-allometric approach allows recognition of phycoerythrin-containing cyanobacteria, cryptomonads, very small red-fluorescing cells (presumably prochlorophytes), and eukaryotic algae of various sizes in many open ocean samples. the speed at which flow cytometric analysis can be performed on freshly coll ... | 1989 | 2776573 |
| instability of tn5 inserts in cyanobacterial cloning vectors. | transposon tn5 was used to produce random insertions in two hybrid cloning vectors for the unicellular cyanobacterium anacystis nidulans. the transposon-containing plasmids were used to localize essential replication functions and to characterize the stability of large inserts in these vectors. the effect of the insertions on plasmid function was tested by transformation into a derivative of a. nidulans that had been cured of the endogenous plasmid used to construct the vectors. a region of appr ... | 1987 | 2820923 |
| sequence analysis of the alcaligenes eutrophus chromosomally encoded ribulose bisphosphate carboxylase large and small subunit genes and their gene products. | the nucleotide sequence of the chromosomally encoded ribulose bisphosphate carboxylase/oxygenase (rubpcase) large (rbcl) and small (rbcs) subunit genes of the hydrogen bacterium alcaligenes eutrophus atcc 17707 was determined. we found that the two coding regions are separated by a 47-base-pair intergenic region, and both genes are preceded by plausible ribosome-binding sites. cotranscription of the rbcl and rbcs genes has been demonstrated previously. the rbcl and rbcs genes encode polypeptides ... | 1987 | 2820933 |
| molecular cloning and isolation of a cyanobacterial gene which increases the uv and methyl methanesulphonate survival of reca strains of escherichia coli k12. | the unicellular cyanobacterium gloeocapsa alpicola contains both photoreactivation and excision repair mechanisms for correcting uv-induced damage to its cellular dna. an 11.5 kb ecori fragment was isolated from a cosmid bank of g. alpicola and was shown to complement a reca deletion in escherichia coli s.17 and jc10289. these reca strains showed increased survival to uv and methyl methanesulphonate (mms) when transformed with the cyanobacterial dna fragment, and also showed filamentation in res ... | 1987 | 2821162 |
| immunological and spectral characterization of partly purified cytochrome oxidase from the cyanobacterium synechocystis 6714. | membranes were isolated by french pressure cell extrusion of lysozyme-preincubated cells of the cyanobacterium synechocystis 6714 after growth in the presence of 0.4 m nacl for 4 days. these cells showed up to 6-fold respiratory activity (oxygen uptake) when compared to control cells. separation of plasma and thylakoid membranes revealed that the major part of cytochrome c oxidase was associated with the latter. immunoblotting of sodium dodecylsulfate polyacrylamide gel electrophorized membranes ... | 1987 | 2825695 |
| sulfide-dependent photosynthetic electron flow coupled to proton translocation in thylakoids of the cyanobacterium oscillatoria limnetica. | light-induced proton translocation coupled to sulfide-dependent electron transport has been studied in isolated thylakoids of the cyanobacterium oscillatoria limnetica. the thylakoids are obtained by osmotic shock of washed spheroplasts, prepared with glycine-betaine as the osmotic stabilizer. 13c nmr studies suggests that betaine is the major osmoregulator in o. limnetica. thylakoid preparations obtained from both sulfide-induced anoxygenic cells and noninduced oxygenic cells are capable of pro ... | 1987 | 2827581 |