| pathways of assimilation of [13n]n2 and 13nh4+ by cyanobacteria with and without heterocysts. | the principal initial product of metabolism of [13n]n2 and 13nh4+ by five diverse cyanobacteria is glutamine. methionine sulfoximine inhibits formation of [13n]glutamine except in the case of gloeothece sp., an organism with a thick sheath through which the inhibitor may not penetrate. thus, glutamine synthetase appears to catalyze the initial step in the assimilation of n2-derived or exogenous nh4+ by these organisms. [13n]glutamate is, in all cases, the second major product of assimilation of ... | 1978 | 418057 |
| ultrastructural and electron spectroscopic analyses of cyanobacteria and bacteria. | the extracellular sheath material and some intracellular cell components of cyanobacteria and phosphate-accumulating sewage bacteria were analysed by electron spectroscopic imaging (esi) and electron energy-loss spectroscopy (eels). the specimens were embedded in water-soluble nanoplast resin without any previous fixation and ultrathin sections were examined in a zeiss cem 902 microscope. a high sulphur content was detected in the inner sheath of the cyanobacterium gloeothece. the elemental comp ... | 1991 | 1651393 |
| fine-structural and chemical analyses on inner and outer sheath of the cyanobacterium gloeothece sp. pcc 6909. | cells of the unicellular cyanobacterium gloeothece sp. pcc 6909 are surrounded by an inner (enclosing 1-2 cells) and an outer (enclosing cell groups) sheath. using conventional epon-embedding in combination with ruthenium-red staining, the inner and outer sheaths appeared similar and displayed multiple bands of electron-dense subunits. however, embedding in nanoplast resin to avoid shrinkage led to the detection of two distinct zones (inner and outer zone) each with several distinct layers. the ... | 1991 | 1905514 |
| the structural nif genes of the cyanobacteria gloeothece sp. and calothrix sp. share homology with those of anabaena sp., but the gloeothece genes have a different arrangement. | probes carrying the anabaena sp. strain pcc 7120 nitrogenase reductase (nifh) and nitrogenase (nifk and nifd) genes were hybridized to southern blots of dna from the unicellular, aerobic nitrogen-fixing cyanobacterium gloeothece sp. strain pcc 6909 and from the filamentous cyanobacterium calothrix sp. strain pcc 7601. these data suggest that the gloeothece sp. nif structural proteins must be similar to those of other diazotrophs and that the ability for aerobic nitrogen fixation does not reside ... | 1983 | 6305921 |
| dinitrogenase reductase adp-ribosyl transferase and dinitrogenase reductase activating glycohydrolase in gloeothece. | | 1994 | 7821588 |
| detection and characterization of cyanobacterial nifh genes. | the dna sequence of a 359-bp fragment of nifh was determined for the heterocystous strains anabaena sp. strain ca (atcc 33047), nostoc muscorum utex 1933, a nostoc sp., gloeothece sp. strain atcc 27152, lyngbya lagerheimii utex 1930, and plectonema boryanum iu 594. results confirmed that the dna sequence of the 359-bp segment is sufficiently variable to distinguish cyanobacterial nifh genes from other eubacterial and arachaeobacterial nifh genes, as well as to distinguish heterocystous from nonh ... | 1994 | 8161180 |
| nitrogenase-specific proteolytic activity in the unicellular cyanobacterium gloeothece. | | 1996 | 8878945 |
| modification of the iron protein of gloeothece nitrogenase: a mass spectrometric study. | | 1996 | 8879021 |
| phylogeny of cyanobacterial nifh genes: evolutionary implications and potential applications to natural assemblages. | dna sequences of a fragment of nifh from diverse cyanobacteria were amplified, cloned and sequenced to determine the evolutionary relationship of nitrogenase within the cyanobacteria as a group, and to provide a basis for the identification of uncultivated strains of cyanobacteria in the environment. analysis of 30 nitrogenase dna and deduced amino acid sequences from cyanobacteria representing five major taxonomic subdivisions showed great variation in phylogenetic distances between the sequenc ... | 1997 | 9141707 |
| synthesis and proteolytic degradation of nitrogenase in cultures of the unicellular cyanobacterium gloeothece strain atcc 27152. | in cultures of the unicellular cyanobacterium gloeothece sp. atcc 27152 growing under alternating 12 h light and 12 h darkness, nitrogenase activity appears as cultures enter the dark phase. synthesis of both component proteins of nitrogenase commences immediately prior to the appearance of activity and continues until about 8 h into the period of darkness. the two components (fe-protein and mofe-protein) are synthesized in a molar ratio of about 3:1. degradation of the nitrogenase proteins star ... | 1999 | 10439414 |
| a novel covalent modification of nitrogenase in a cyanobacterium. | in extracts of the unicellular cyanobacterium gloeothece, the fe-protein of nitrogenase can be separated by sds-page into two antigenically identifiable components. unlike the situation in photosynthetic bacteria such as rhodospirillum rubrum, these two forms do not arise from covalent modification of the protein by adp-ribosylation. rather, the fe-protein of gloeothece nitrogenase is subjected to modification by palmitoylation. | 2000 | 10692592 |
| multiple evidence for widespread and general occurrence of type-iii pha synthases in cyanobacteria and molecular characterization of the pha synthases from two thermophilic cyanobacteria: chlorogloeopsis fritschii pcc 6912 and synechococcus sp. strain ma19. | eleven different cyanobacteria were investigated with respect to their capabilities to synthesize poly-3-hydroxybutyrate [poly(3hb)] and the type of poly-beta-hydroxyalkanoic acid (pha) synthase accounting for the synthesis of this polyester. several methods, including (i) southern blot analysis using a phac-specific dna probe, (ii) western blot analysis using specific polyclonal anti-phae antibodies raised in this study against phae of synechocystis sp. strain pcc 6803, (iii) generation and seq ... | 2001 | 11700355 |
| nonribosomal peptide synthetase genes occur in most cyanobacterial genera as evidenced by their distribution in axenic strains of the pcc. | previous studies largely carried out with environmental samples or axenic and non-axenic cultures suggested that cyanobacteria may be a rich source of hitherto unexplored bioactive compounds. this has been confirmed in the present study by a screening of 146 axenic strains from the pasteur culture collection (pcc) of cyanobacteria. use of degenerate pcr primers, designed on the basis of conserved sequence motifs in the aminoacyl-adenylation domain of peptide synthetases, revealed the presence of ... | 2001 | 11734889 |
| removal of cadmium and manganese by a non-toxic strain of the freshwater cyanobacterium gloeothece magna. | the ability of both living and dry cells of gloeothece magna, a non-toxic freshwater cyanobacterium, to adsorb cadmium and manganese is demonstrated in this study. chlorophyll a content of living cells was not influenced by either cadmium or manganese concentrations, indicating that adsorption of both cd2+ and mn2+ by living cells of g. magna, was independent of the metabolic state of the organism. moreover, the adsorption of both cd2+ and mn2+ to living cells and dry cells, was dependent on the ... | 2001 | 11763042 |
| characterization and transcriptional analysis of hupslw in gloeothece sp. atcc 27152: an uptake hydrogenase from a unicellular cyanobacterium. | the structural genes (hupsl) encoding an uptake hydrogenase in the unicellular cyanobacterium gloeothece sp. atcc 27152, a strain capable of aerobic n(2) fixation, were identified and sequenced. 3'-race experiments uncovered the presence of an additional orf 184 bp downstream of hupl, showing a high degree of sequence identity with a gene encoding an uptake-hydrogenase-specific endopeptidase (hupw) in other cyanobacteria. in addition, the transcription start point was identified 238 bp upstream ... | 2004 | 15528652 |
| development of a universal microarray based on the ligation detection reaction and 16s rrna gene polymorphism to target diversity of cyanobacteria. | the cyanobacteria are photosynthetic prokaryotes of significant ecological and biotechnological interest, since they strongly contribute to primary production and are a rich source of bioactive compounds. in eutrophic fresh and brackish waters, their mass occurrences (water blooms) are often toxic and constitute a high potential risk for human health. therefore, rapid and reliable identification of cyanobacterial species in complex environmental samples is important. here we describe the develop ... | 2004 | 15574913 |
| does green light influence the fluorescence properties and structure of phototrophic biofilms? | artificial illumination can harm works of art by inducing the development of photosynthetic biofilms. with the aim of preventing biodeterioration or esthetic damage to such surfaces, we evaluated and compared the effects of illuminating biofilms formed by gloeothece membranacea (cyanobacteria) and chlorella sorokiniana (chlorophyta) using exclusively white or green light. | 2006 | 16598012 |
| 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 |
| sheathless mutant of cyanobacterium gloeothece sp. strain pcc 6909 with increased capacity to remove copper ions from aqueous solutions. | the cyanobacterium gloeothece sp. strain pcc 6909 and its sheathless mutant were tested for their abilities to remove copper ions from aqueous solutions, with the aim of defining the role of the various outermost polysaccharidic investments in the removal of the metal ions. microscopy studies and chemical analyses revealed that, although the mutant does not possess a sheath, it releases large amounts of polysaccharidic material (released exocellular polysaccharides [rps]) into the culture medium ... | 2008 | 18326679 |
| diazotrophy under continuous light in a marine unicellular diazotrophic cyanobacterium, gloeothece sp. 68dga. | nitrogenase is extremely sensitive to molecular oxygen (o(2)), and unicellular diazotrophic cyanobacteria separate nitrogen (n(2))-fixation and photosynthesis to protect nitrogenase from o(2) produced by photosynthesis. when grown under 12 h light/12 h dark cycles (ld), the marine unicellular diazotrophic cyanobacterium gloeothece sp. 68dga expressed the nitrogenase protein and its activity (acetylene reduction activity) only during the dark phase. however, this strain was able to grow diazotrop ... | 2008 | 18599815 |
| quorum sensing in cyanobacteria: n-octanoyl-homoserine lactone release and response, by the epilithic colonial cyanobacterium gloeothece pcc6909. | quorum sensing involving acyl homoserine lactones (ahls) is a density-dependent form of intercellular communication that occurs in many different members of the group proteobacteria. however, to date, there have been few investigations of its occurrence in cyanobacteria. here, using both a bioreporter agrobacterium tumefaciens ntl4 (pzlr4) and mass spectrometry, we provide evidence of n-octanoyl homoserine lactone (c8-ahl) production in axenic cultures of the cyanobacterium gloeothece pcc6909 an ... | 2008 | 18633449 |
| determining the specific microbial populations and their spatial distribution within the stromatolite ecosystem of shark bay. | the stromatolites at shark bay, western australia, are analogues of some of the oldest evidence of life on earth. the aim of this study was to identify and spatially characterize the specific microbial communities associated with shark bay intertidal columnar stromatolites. conventional culturing methods and construction of 16s rdna clone libraries from community genomic dna with both universal and specific pcr primers were employed. the estimated coverage, richness and diversity of stromatolite ... | 2009 | 19092864 |
| oxygen and the light-dark cycle of nitrogenase activity in two unicellular cyanobacteria. | cyanobacteria capable of fixing dinitrogen exhibit various strategies to protect nitrogenase from inactivation by oxygen. the marine crocosphaera watsonii wh8501 and the terrestrial gloeothece sp. pcc6909 are unicellular diazotrophic cyanobacteria that are capable of aerobic nitrogen fixation. these cyanobacteria separate the incompatible processes of oxygenic photosynthesis and nitrogen fixation temporally, confining the latter to the dark. although these cyanobacteria thrive in fully aerobic e ... | 2010 | 19691503 |
| using extracellular polymeric substances (eps)-producing cyanobacteria for the bioremediation of heavy metals: do cations compete for the eps functional groups and also accumulate inside the cell? | many cyanobacteria produce extracellular polymeric substances (eps) mainly of polysaccharidic nature. these eps can remain associated to the cell surface as sheaths, capsules and/or slimes, or be liberated into the surrounding environment as released polysaccharides (rps). the ability of eps-producing cyanobacteria to remove heavy metals from aqueous solutions has been widely reported in the literature, focusing mainly on the biotechnological potential. however, the knowledge of the effects of t ... | 2010 | 20966085 |
| itraq-based quantitative proteomic analysis of gloeothece sp. pcc 6909: comparison with its sheathless mutant and adaptations to nitrate deficiency and sulfur limitation. | gloeothece sp. pcc 6909 is a unicellular n(2)-fixing cyanobacterium with a well defined and highly developed sheath surrounding its cells. a sheathless mutant of this strain was previously obtained by chemical mutagenesis and, although lacking the sheath, it releases large amounts of polysaccharides into the culture medium. to provide a global understanding on the metabolic differences between the two phenotypes, the proteomes of the wild type and mutant were analyzed using a cross-species prote ... | 2011 | 21964258 |