Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| toxicity assessment of heavy metals with nostoc muscorum l. | heavy metals in aquatic ecosystem (mn, ni, zn, cu) were tested for their toxicity against nostoc muscorum l., a common fresh water phytoplankton, with respect to chlorophyll, protein, total carbohydrate and starch contents along with growth (od). mn showed stimulatory effect up to 1.5 ppm for all the observed parameters. however, ni, zn and cu (0.1, 0.2, 0.3, 0.4 and 0.5 ppm) showed adverse effects even at 0.1 ppm. chlorophyll was most sensitive parameter followed by carbohydrate, protein and st ... | 2005 | 16114473 |
| laser flash-induced kinetic analysis of cytochrome f oxidation by wild-type and mutant plastocyanin from the cyanobacterium nostoc sp. pcc 7119. | oxidation of the soluble, truncated form of cytochrome f by wild-type and mutant species of plastocyanin has been analyzed by laser flash absorption spectroscopy in the cyanobacterium nostoc (formerly, anabaena) sp. pcc 7119. at low ionic strengths, the apparent electron transfer rate constant of cytochrome f oxidation by wild-type plastocyanin is 1.34 x 10(4) s(-)(1), a value much larger than those determined for the same proteins from other organisms. upon site-directed mutagenesis of specific ... | 2005 | 16114897 |
| the application of micro-ftir spectroscopy to analyze nutrient stress-related changes in biomass composition of phytoplankton algae. | micro-fourier transform infrared (ftir) spectroscopy was used to study changes in spectral features of three species of cyanobacteria (microcystis aeruginosa, croococcus minutus, and nostoc sp.) and two bacillariophyceae (cyclotella meneghiniana, and phaeodactylum tricornutum) in response to nutrient stress. the change of physiological state of the cells was followed during a 4-week starvation period on the basis of physiological key parameters and by means of ftir spectroscopy. changes in the i ... | 2005 | 16122937 |
| clustered genes required for synthesis and deposition of envelope glycolipids in anabaena sp. strain pcc 7120. | photoreduction of dinitrogen by heterocyst-forming cyanobacteria is of great importance ecologically and for subsistence rice agriculture. their heterocysts must have a glycolipid envelope layer that limits the entry of oxygen if nitrogenase is to remain active to fix dinitrogen in an oxygen-containing milieu (the fox+ phenotype). genes alr5354 (hgld), alr5355 (hglc) and alr5357 (hglb) of the filamentous cyanobacterium, anabaena sp. strain pcc 7120, and hgle of nostoc punctiforme are required fo ... | 2005 | 16164561 |
| crystallization and preliminary x-ray crystallographic analysis of the glur0 ligand-binding core from nostoc punctiforme. | glur0 from nostoc punctiforme (npglur0) is a bacterial homologue of the ionotropic glutamate receptor. the ligand-binding core of npglur0 was crystallized at 294 k using the hanging-drop vapour-diffusion method. the l-glutamate-complexed crystal belongs to space group c222(1), with unit-cell parameters a = 78.0, b = 145.1, c = 132.1 a. the crystals contain three subunits in the asymmetric unit, with a vm value of 2.49 a3 da(-1). the diffraction limit of the l-glutamate complex data set was 2.1 a ... | 2005 | 16511224 |
| poly-beta-hydroxybutyrate accumulation in nostoc muscorum and spirulina platensis under phosphate limitation. | nostoc muscorum and spirulina platensis were grown under phosphate deficiency in order to investigate the role of internal phosphate pool and activity of alkaline phosphatase on poly-beta-hydroxybutyrate (phb) accumulation. phb accumulation in n. muscorum increased to 22.7% of dry weight (dw) after 4 day of phosphate deficiency, while the internal phosphate pool reduced to the level of 0.02 microm mg dw(-1) at a maximum apase activity of 2.57nm pnp mg dw(-1) h(-1). in contrary, s. platensis depi ... | 2005 | 16425456 |
| growth and heavy metals removal efficiency of nostoc muscorum and anabaena subcylindrica in sewage and industrial wastewater effluents. | the growth of nostoc muscorum and anabaena subcylindrica in sterilized sewage wastewater and n. muscorum in sterilized wastewater of el-soda company was higher than those grown in allen synthetic medium. whereas, the growth of a. subcylindrica in el-soda company sterilized wastewater and n. muscorum as well as a. subcylindrica grown in verta company sterilized wastewater was slightly lower than that grown in the standard synthetic medium. the contents of chlorophyll a, carotenoids and protein of ... | 2005 | 21783496 |
| sequence based data supports a single nostoc strain in individual coralloid roots of cycads. | the genetic diversity of cyanobacteria associated with cycads was examined using the trna(leu) (uaa) intron as a genetic marker. coralloid roots of both natural populations of the cycad macrozamia riedlei (fischer ex gaudichaud-beaupré) c.a. gardner growing in perth, australia and cycads growing in greenhouses, also in perth, were used and their respective cyanobionts analyzed. several nostoc strains were found to be involved in this symbiosis, both in natural populations and greenhouse-originat ... | 2004 | 19712296 |
| first documented cure of a suggestive exogenous reinfection in polymyositis with same but multidrug resistant m. tuberculosis. | mdr mycobacterium tuberculosis is the major cause of treatment failure in tuberculosis patients, especially in immunosuppressed. we described a young polymyositis patient on immunosuppressive therapy who was started with antituberculosis therapy as a susceptible strain of m. tuberculosis was isolated from a single cutaneous abscess in his neck and from regional lymph nodes. | 2004 | 15617569 |
| a cyanobacterial protein with similarity to phytochelatin synthases catalyzes the conversion of glutathione to gamma-glutamylcysteine and lacks phytochelatin synthase activity. | phytochelatins are glutathione-derived, non-translationally synthesized peptides essential for cadmium and arsenic detoxification in plant, fungal and nematode model systems. recent sequencing programs have revealed the existence of phytochelatin synthase-related genes in a wide range of organisms that have not been reported yet to produce phytochelatins. among those are several cyanobacteria. we have studied one of the encoded proteins (alr0975 from nostoc sp. strain pcc 7120) and demonstrate h ... | 2004 | 15561184 |
| cyanobacteria in antarctica: ecology, physiology and cold adaptation. | cyanobacterial species composition of fresh water and terrestrial ecosystems and chemical environment of water in schirmacher oasis in continental antarctica was investigated. over 35 species of cyanobacteria were recorded. diazotrophic species both heterocystous and unicellular contributed more than half to the count except in lake ecosystem. the species composition varied among the fresh water as well as terrestrial ecosystems. the physico-chemical analyses of water revealed its poor nurient c ... | 2004 | 15559974 |
| isolation and structure determination of cryptophycins 38, 326, and 327 from the terrestrial cyanobacterium nostoc sp. gsv 224. | cryptophycin-38 (2), -326 (3), and -327 (4) are three new trace constituents of the terrestrial cyanobacterium nostoc sp. gsv 224. cryptophycin-38 is a stereoisomer of cryptophycin-1 (1) and to date is the only naturally occurring analogue that possesses a s,s epoxide group in unit a. cryptophycin-327 is a geometric isomer that differs from 1 in having a cis delta(2)-double bond in unit a. cryptophycin-326 is related to cryptophycin-21, but has two chlorines ortho to the methoxy group in unit b. ... | 2004 | 15332864 |
| 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 |
| decomposition of microcystin-lr, microcystin-rr, and microcystin-yr in water samples submitted to in vitro dissolution tests. | the presence of cyanobacterial toxins (microcystins) in waters and food increases the risk of toxicity to animal and human health. these toxins can degrade in the human gastrointestinal tract before they are absorbed. to evaluate this possible degradation, water samples spiked with known concentrations of microcystins mc-lr, mc-rr, and mc-yr, which are the toxins most commonly produced by such toxic cyanobacteria as microcystis aeruginosa, oscillatoria spp., and nostoc spp., were submitted to a ... | 2004 | 15366845 |
| construction and use of gfp reporter vectors for analysis of cell-type-specific gene expression in nostoc punctiforme. | two transcriptional reporter shuttle vectors were constructed for the filamentous cyanobacterium nostoc punctiforme using the green fluorescence protein (gfp) reporter. both the ampicillin- and kanamycin-resistant versions of the plasmid allow promoters to be directionally cloned into a multiple cloning site preceding a promoterless gfp gene using an escherichia coli host. the ability of the self-replicating shuttle plasmids to report cell-type-specific gene expression in n. punctiforme was test ... | 2004 | 15369854 |
| [effect of cadmium on the absorption and excitation energy transfer in cyanobacterium nostoc muscorum]. | the absorption and energy transfer between pigments in nostoc muscorum by the action of 10(-4) m cd2+, when the cyanobacterium remains viable, and in the presence of 10(-3) m cd2+, which causes the death of cells during 3-4 weeks of incubation, were studied. a comparative study by the methods of absorption and fluorescence spectrophotometry at 295 and 77 k, including derivative spectroscopy and deconvolution of emission spectra into a number of gaussian components, showed that, in the presence o ... | 2004 | 15458254 |
| discovery of rare and highly toxic microcystins from lichen-associated cyanobacterium nostoc sp. strain io-102-i. | the production of hepatotoxic cyclic heptapeptides, microcystins, is almost exclusively reported from planktonic cyanobacteria. here we show that a terrestrial cyanobacterium nostoc sp. strain io-102-i isolated from a lichen association produces six different microcystins. microcystins were identified with liquid chromatography-uv mass spectrometry by their retention times, uv spectra, mass fragmentation, and comparison to microcystins from the aquatic nostoc sp. strain 152. the dominant microcy ... | 2004 | 15466511 |
| [bioinformatics studies on photosynthetic system genes in cyanobacteria and chloroplasts]. | this study compared homology of base sequences in genes encoding photosynthetic system proteins of cyanobacteria (synechocystics sp. pcc6803, nostoc sp. pcc7120) with these of chloroplasts (from marchantia polymorpha, nicotiana tobacum, oryza sativ, euglena gracilis, pinus thunbergii, zea mays, odentella sinesis, cyanophora paradoxa, porphyra purpurea and arabidopsis thaliana) by blast method. while the gene sequence of synechocystics sp. pcc6803 was considered as the criterion (100%) the homolo ... | 2004 | 15490883 |
| identification and analysis of a siderophore biosynthetic gene cluster from agrobacterium tumefaciens c58. | using the complete genome sequence from agrobacterium tumefaciens c58, the authors identified a secondary metabolite gene cluster that encodes the biosynthesis of a metabolite with siderophore activity. support for this conclusion came from genetic and regulatory analysis of the gene cluster, along with the purification of a metabolite from a. tumefaciens c58 with iron-chelating activity. genetic analysis of mutant strains disrupted in this gene cluster showed that these strains grew more slowly ... | 2004 | 15528670 |
| novel classes of mutants of the cyanobacterium nostoc muscorum showing absolute requirement of cs1 or rb1 for diazotrophy. | 2004 | 15248149 | |
| a mechanism for slow release of biomagnified cyanobacterial neurotoxins and neurodegenerative disease in guam. | as root symbionts of cycad trees, cyanobacteria of the genus nostoc produce beta-methylamino-l-alanine (bmaa), a neurotoxic nonprotein amino acid. the biomagnification of bmaa through the guam ecosystem fits a classic triangle of increasing concentrations of toxic compounds up the food chain. however, because bmaa is polar and nonlipophilic, a mechanism for its biomagnification through increasing trophic levels has been unclear. we report that bmaa occurs not only as a free amino acid in the gua ... | 2004 | 15295100 |
| combined directed ortho and remote metalation-cross-coupling strategies. general method for benzo[a]carbazoles and the synthesis of an unnamed indolo[2,3-a]carbazole alkaloid. | [reaction: see text] an efficient route to benzo[a]carbazoles via a metalation-cross-coupling sequence has been demonstrated and its application to the synthesis of the antitumor and antiviral alkaloid 6-cyano-5-methoxy-12-methylindolo[2,3-a]carbazole has been achieved. | 2004 | 15228262 |
| comparative toxicological evaluation of untreated and treated tannery effluent with nostoc muscorum l. (algal assay) and microtox bioassay. | the relative sensitivity of tannery effluent before and after treatment was compared by employing nostoc muscorum and microtox assay in laboratory. the effect on chlorophyll, protein and biomass content of nostoc muscorum was studied with the luminescent property inhibition of photobacterium phosphorium and compared with algal bioassay. the results of microtox assay after 5, 15 and 30 min of exposure were compared with data obtained from algal bioassay. it was observed that the luminescent prope ... | 2004 | 15195832 |
| accumulation of poly-beta-hydroxybutyrate in nostoc muscorum: regulation by ph, light-dark cycles, n and p status and carbon sources. | accumulation of poly-beta-hydroxybutyrate (phb) in nostoc muscorum was studied. cells harvested at stationary phase of growth depicted maximum accumulation i.e. 8.6% (w/w) of dry cells as compared to lag (4.1%) or logarithmic (6.1%) phases of cultures. in contrast to alkaline ph, acidic ph, continuous illumination and cells grown in presence of combined nitrogen sources, such as nh(4)cl and kno(3), were found to affect phb accumulation negatively. however, p-deficiency and addition of exogenous ... | 2004 | 15734319 |
| cloning, sequencing, and biochemical characterization of the nostocyclopeptide biosynthetic gene cluster: molecular basis for imine macrocyclization. | nostocyclopeptides a1 and a2 are novel cyclic heptapeptides produced by the terrestrial cyanobacterium nostoc sp. atcc53789 that possess a unique imino linkage in the macrocyclic ring. herein we report the cloning, sequencing, annotation, and biochemical analysis of the 33-kb nostocyclopeptide (ncp) biosynthetic gene cluster, which includes seven open reading frames predicted to be involved in the biosynthesis and transport of these natural products. the genetic architecture and domain organizat ... | 2004 | 14697508 |
| a correlation matrix of alkaline phosphatase and sporulation in diazotrophic cyanobacteria and its thermo-tolerant mutant. | alkaline phosphatase (phosphomonoesterase i.e. pmease) activity in heterocystous cyanobacteria anabaena flos-aquae, nostoc calcicola, calothrix brevissima, scytonema javanicum and hapalosiphon intricatus is known to be temperature and ph dependent. maximum level of enzyme activity was recorded at either 35 degrees c or 37.5 degrees c. also, the cell bound phosphomonoesterase enzyme was shown to exhibit ph optima of 10.0 or 10.2. a thermo-tolerant (tr) mutant isolated after mnng (n-methyl-n'-nitr ... | 2004 | 15790075 |
| generation of reactive oxygen species undergoing redox cycle of nostocine a: a cytotoxic violet pigment produced by freshwater cyanobacterium nostoc spongiaeforme. | nostocine a (1) is an extracellular cytotoxic violet pigment produced by the freshwater cyanobacterium, nostoc spongiaeforme tistr 8169. treatment with 1 was found to accelerate the generation of reactive oxygen species (ros) in the green alga, chlamydomonas reinhardtii, in the light. in vitro analysis revealed that 1 specifically eliminated superoxide radical anion (o(2)(-)) among several ros tested. during the course of the reaction, oxygen (o(2)) was simultaneously synthesized and the o(2) sy ... | 2004 | 15099903 |
| evaluation of nostoc strain atcc 53789 as a potential source of natural pesticides. | the cyanobacterium nostoc strain atcc 53789, a known cryptophycin producer, was tested for its potential as a source of natural pesticides. the antibacterial, antifungal, insecticidal, nematocidal, and cytotoxic activities of methanolic extracts of the cyanobacterium were evaluated. among the target organisms, nine fungi (armillaria sp., fusarium oxysporum f. sp. melonis, penicillium expansum, phytophthora cambivora, p. cinnamomi, rhizoctonia solani, rosellinia, sp., sclerotinia sclerotiorum, an ... | 2004 | 15184126 |
| response of desert biological soil crusts to alterations in precipitation frequency. | biological soil crusts, a community of cyanobacteria, lichens, and mosses that live on the soil surface, occur in deserts throughout the world. they are a critical component of desert ecosystems, as they are important contributors to soil fertility and stability. future climate scenarios predict alteration of the timing and amount of precipitation in desert environments. because biological soil crust organisms are only metabolically active when wet, and as soil surfaces dry quickly in deserts du ... | 2004 | 14689292 |
| a preliminary investigation of the nostoc punctiforme proteome. | nostoc punctiforme atcc 29133 is a filamentous terrestrial cyanobacterium (prokaryote) that expresses several different phenotypes in response to environmental cues. when grown in nitrogen-deficient media the most abundant proteins in addition to phycobiliproteins were superoxide dismutase, atp synthase, and peptidyl-prolyl cis-trans isomerases. a methylated peptide from an akinete marker protein was also identified, suggesting that methylation could potentially play a regulatory role through si ... | 2004 | 15094385 |
| bacterial life and dinitrogen fixation at a gypsum rock. | the organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. the cyanobacterial consortium consisted almost exclusively of chroococcidiopsis spp. the organisms of the shards expressed nitrogenase activity (c2h2 reduction) aerobically and in light. after a prolonged period of drought at the rock, the cells were inactive, but they resumed nitrogenase activity 2 to 3 days after the addition of water. in a suspension culture of chroococcidiops ... | 2004 | 15574902 |
| 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 |
| ecosystems on ice: the microbial ecology of markham ice shelf in the high arctic. | microbial communities occur throughout the cryosphere in a diverse range of ice-dominated habitats including snow, sea ice, glaciers, permafrost, and ice clouds. in each of these environments, organisms must be capable of surviving freeze-thaw cycles, persistent low temperatures for growth, extremes of solar radiation, and prolonged dormancy. these constraints may have been especially important during global cooling events in the past, including the precambrian glaciations. one analogue of these ... | 2004 | 15094087 |
| comparison of light and dark nitrogenase activity in selected soil cyanobacteria. | frequency of heterocytes and nitrogenase activity (na) under light and dark cultivation conditions was determined in 12 cyanobacterial strains isolated from various soil habitats. in spite of a high variability, significant differences in na among the strains were found in response of light and dark cultivation. relatively high na (9.9-15.3 micromol/h c2h4 per g fresh mass) under light conditions and basal na after 12 h of dark cultivation were detected in anabaena, nodularia, tolypothrix, and 1 ... | 2004 | 15530010 |
| gas exchange in the filamentous cyanobacterium nostoc punctiforme strain atcc 29133 and its hydrogenase-deficient mutant strain nhm5. | nostoc punctiforme atcc 29133 is a nitrogen-fixing, heterocystous cyanobacterium of symbiotic origin. during nitrogen fixation, it produces molecular hydrogen (h(2)), which is recaptured by an uptake hydrogenase. gas exchange in cultures of n. punctiforme atcc 29133 and its hydrogenase-free mutant strain nhm5 was studied. exchange of o(2), co(2), n(2), and h(2) was followed simultaneously with a mass spectrometer in cultures grown under nitrogen-fixing conditions. isotopic tracing was used to se ... | 2004 | 15066806 |
| devr-devs is a bona fide two-component system of mycobacterium tuberculosis that is hypoxia-responsive in the absence of the dna-binding domain of devr. | two-component systems play a central role in the adaptation of pathogenic bacteria to the environment prevailing within host tissues. the genes encoding the response regulator devr (rv3133c/dosr) and the cytoplasmic portion (devs(201)) of the histidine kinase devs (rv3132c/doss), a putative two-component system of mycobacterium tuberculosis, were cloned and the protein products were overexpressed, purified and refolded as n-terminally his(6)-tagged proteins from escherichia coli. devs(201) under ... | 2004 | 15073296 |
| molecular evolution of pas domain-containing proteins of filamentous cyanobacteria through domain shuffling and domain duplication. | when the entire genome of a filamentous heterocyst-forming n2-fixing cyanobacterium, anabaena sp. pcc 7120 (anabaena) was determined in 2001, a large number of pas domains were detected in signal-transducing proteins. the draft genome sequence is also available for the cyanobacterium, nostoc punctiforme strain atcc 29133 (nostoc), that is closely related to anabaena. in this study, we extracted all pas domains from the nostoc genome sequence and analyzed them together with those of anabaena. clu ... | 2004 | 15449540 |
| expression of cyanobacterial genes involved in heterocyst differentiation and dinitrogen fixation along a plant symbiosis development profile. | members of the cyanobiont genus nostoc, forming an endosymbiosis with members of the angiosperm genus gunnera, undergo a number of characteristic phenotypic changes during the development of the symbiosis, the genetic background of which is largely unknown. transcription patterns of genes related to heterocyst differentiation and dinitrogen fixation and corresponding protein profiles were examined, using reverse transcription-polymerase chain reaction and western blots, along a developmental (ap ... | 2004 | 15077676 |
| role of cyanobacteria in the persistence of vibrio cholerae o139 in saline microcosms. | recently, a new strain of cholera, vibrio cholerae o139, has emerged as an epidemic strain, but there is little information about its environmental reservoir. the present investigation was aimed to determine the role of cyanobacteria in the persistence of v. cholerae o139 in microcosms. an environmental isolate of v. cholerae o139 and three cyanobacteria (anabaena sp., nostoc sp., and hapalosiphon sp.) were used in this study. survival of culturable v. cholerae o139 in microcosms was monitored u ... | 2004 | 15052315 |
| [phagoresistance of filamentous cyanobacteria clones]. | the paper deals with formation regularities of phagoresistant clones of cyanobacteria in two productive virus-cell systems: heterocyst cyanobacterium nostoc linckia--cyanophage n-2, and mutant in heterocysts strain of anabaena variabilis--cyanophage a-1. frequency of spontaneous formation of phagoresistant clones of cyanobacterium n. linckia varies within 1.0-8.0 x 10(-6) per a cell, a. variabilis--5.0 x 10(-6)-7.0 x 10(-7) per cell. all the studied phagoresistant clones of n. linckia have ident ... | 2004 | 15104055 |
| cross talk between devs sensor kinase homologue, rv2027c, and devr response regulator of mycobacterium tuberculosis. | rv2027c is a putative orphan histidine sensor kinase that bears strong homology to devs of the hypoxia-responsive devr-devs two-component system in m. tuberculosis. the cytosolic c-terminal domain of rv2027c protein (rv2027c(194)) was overexpressed in e. coli and biochemically characterized. rv2027c(194) underwent autophosphorylation at a conserved his(392) residue and engaged in phosphotransfer with devr response regulator. the rates of autophosphorylation and the stabilities of the phosphoryla ... | 2004 | 15135056 |
| impact of nitrophenols on the photosynthetic electron transport chain and atp content in nostoc muscorum and chlorella vulgaris. | concentration-dependent inhibition of the photosynthetic electron transport chain (photosystem i (ps i), photosystem ii (ps ii) and whole chain reaction) and atp content was observed in nostoc muscorum and chlorella vulgaris grown with o-nitrophenol, m-nitrophenol, or 2,4-dinitrophenol. although the extents of inhibition of the photosynthetic electron transport chain in both organisms were similar, ps ii was more sensitive than ps i and whole chain reaction to the nitrophenols. depletion of the ... | 2004 | 15157580 |
| light-induced intramolecular charge movements in microbial rhodopsins in intact e. coli cells. | microbial rhodopsins undergo cyclic photochemical reactions (photocycles) in which proton transfers and conformational changes result in charge displacements during transitions between photocycle intermediates. we report a new photoelectric method to monitor charge movements during rhodopsin photocycling with fast kinetic resolution in suspensions of intact e. coli cells. the method monitors electrical currents resulting from asymmetric photoexcitation of microbial rhodopsins by a unilateral las ... | 2004 | 15170484 |
| diazotrophic community structure and function in two successional stages of biological soil crusts from the colorado plateau and chihuahuan desert. | the objective of this study was to characterize the community structure and activity of n2-fixing microorganisms in mature and poorly developed biological soil crusts from both the colorado plateau and chihuahuan desert. nitrogenase activity was approximately 10 and 2.5 times higher in mature crusts than in poorly developed crusts at the colorado plateau site and chihuahuan desert site, respectively. analysis of nifh sequences by clone sequencing and the terminal restriction fragment length poly ... | 2004 | 14766579 |
| characterization of phytochelatin synthase-like protein encoded by alr0975 from a prokaryote, nostoc sp. pcc 7120. | phytochelatins (pcs) are well known as the heavy metal-detoxifying peptides in higher plants, eukaryotic algae, fungi, and nematode. in contrast, neither pcs nor pc synthase genes have ever been identified in any prokaryotes. the genome sequences for the cyanobacterium nostoc sp. pcc 7120 were recently completed and allowed us to identify a gene encoding a pc synthase-like protein, termed alr0975. the predicted product of alr0975 contains the conserved n-terminal domain but not the variable c-te ... | 2004 | 14975765 |
| cloning of two carotenoid ketolase genes from nostoc punctiforme for the heterologous production of canthaxanthin and astaxanthin. | for the heterologous synthesis of keto-carotenoids such as astaxanthin, two carotenoid ketolase genes crtw38 and crtw148, were cloned from the cyanobacterium, nostoc punctiforme pcc 73102 and functionally characterized. upon expression in escherichia coli, both genes mediated the conversion of beta-carotene to canthaxanthin. however in a zeaxanthin-producing e. coli, only the gene product of crtw148 introduced 4-keto groups into the 3,3'-dihydroxy carotenoid zeaxanthin yielding astaxanthin. the ... | 2004 | 15269553 |
| deactivation of photosynthetic activities is triggered by loss of a small amount of water in a desiccation-tolerant cyanobacterium, nostoc commune. | changes in photosynthetic activities under hypertonic conditions were studied in a terrestrial, highly desiccation-tolerant cyanobacterium, nostoc commune, and in some desiccation-sensitive cyanobacteria. the amounts of water sustained in the colony matrix outside the n. commune cells and the cellular solute concentration were estimated by measuring the water potential, and the solute concentration was supposed to correspond to around 0.22 m sorbitol. incubation of the colonies in 0.8 m sorbitol ... | 2004 | 15295070 |
| sensor domain of the mycobacterium tuberculosis receptor ser/thr protein kinase, pknd, forms a highly symmetric beta propeller. | diverse pathogenic bacteria produce transmembrane receptor ser/thr protein kinases (stpks), but little is known about the signals mediated by these "eukaryotic-like" proteins. to explore the basis for signaling in the bacterial stpk receptor family, we determined the structure of the sensor domain of mycobacterium tuberculosis pknd. in two crystal forms, the pknd sensor domain forms a rigid, six-bladed beta-propeller with a flexible tether to the transmembrane domain. the pknd sensor domain is t ... | 2004 | 15136047 |
| the iron superoxide dismutase from the filamentous cyanobacterium nostoc pcc 7120. localization, overexpression, and biochemical characterization. | the nitrogen-fixing filamentous cyanobacterium nostoc pcc 7120 (formerly named anabaena pcc 7120) possesses two genes for superoxide dismutase, a unique membrane-associated manganese superoxide dismutase (mnsod) and a soluble iron superoxide dismutase (fesod). a phylogenetic analysis of fesods shows that cyanobacterial enzymes form a well separated cluster with filamentous species found in one subcluster and unicellular species in the other. activity staining, inhibition patterns, and immunogold ... | 2004 | 15302891 |
| evidence for multiple lateral transfers of the circadian clock cluster in filamentous heterocystic cyanobacteria nostocaceae. | cyanobacteria are the first prokaryotes reported to show circadian rhythmicity, which is regulated by a cluster of three genes: kaia, kaib, and kaic. phylogenetic analysis of the kaibc cluster in filamentous cyanobacteria of the family nostocaceae including nodularia spumigena and nostoc linckia from arubotaim cave, mt. sedom, israel, indicated that this cluster has experienced multiple lateral transfers. the transfers have occurred in different periods of the species' evolution. the data obtain ... | 2004 | 15045489 |
| studies on phosphate uptake, accumulation and activity of alkaline phosphatase of nostoc muscorum under cd stress. | 2004 | 15057710 | |
| biotransformation of hydrocortisone by a natural isolate of nostoc muscorum. | hydrocortisone was converted in the culture of an isolated strain of the cyanobacterium nostoc muscorum ptcc 1636 into some androstane and pregnane derivatives. the microorganism was, isolated during a screening program from soil samples collected from paddy fields of north of iran. the bioproducts obtained were purified using chromatographic methods and identified as 11beta-hydroxytestosterone, 11beta-hydroxyandrost-4-en-3,17-dione and 11beta,17alpha,20beta,21-tetrahydroxypregn-4-en-3-one on th ... | 2004 | 15587704 |
| real-time studies on microalgae under microgravity. | using remote sensing technique, we investigated real-time nostoc sphaeroides kütz (cyanobacterium) in closed system under microgravity by shenzhou-2 spacecraft in january 2001. the experiments had 1 g centrifuges in space for control and ground control group experiments were also carried out in the same equipments and under the same controlled condition. the data about the population growth of nostoc sp. of experiments and temperature changes of system were got from spacecraft every minute. from ... | 2004 | 15791730 |
| [cloning and analysis of cdna encoding key enzyme gene (dxr) of the non-mva pathway in taxus chinensis cells]. | two distinct routes (classical mevalonate pathway and a novel mevalonate-independent pathway) are utilized by plants for the biosynthesis of isopentenyl diphosphate, the universal precursor of isoprenoids (fig. 1). present researches indicated that taxol was synthesized mainly via non-mevalonate pathway, but not genetic evidence was showed. the second step in non-mevalonate pathway involves an intramolecular rearrangement and subsequent reduction of deoxyxylulose phosphate to yield 2-c-methyl-d- ... | 2004 | 15968987 |
| a dna adenine methyltransferase of escherichia coli that is cell cycle regulated and essential for viability. | dna sequence analysis revealed that the putative yhdj dna methyltransferase gene of escherichia coli is 55% identical to the nostoc sp. strain pcc7120 gene encoding dna methyltransferase avaiii, which methylates adenine in the recognition sequence, atgcat. the yhdj gene was cloned, and the enzyme was overexpressed and purified. methylation and restriction analysis showed that the dna methyltransferase methylates the first adenine in the sequence atgcat. this dna methylation was found to be regul ... | 2004 | 15028690 |
| comprehensive analysis system using liquid chromatography-mass spectrometry for the biosynthetic study of peptides produced by cyanobacteria. | microcystins are hepatotoxic heptapeptides and general tumor promoters produced by several species of the genera microcystis, anabaena, oscillatoria and nostoc. they are non-ribosomally synthesized via a mixed polyketide synthase/non-ribosomal peptide synthetase system called microcystin synthetase. we have carried out the detection, isolation and structural determination of non-toxic peptides produced together with microcystins by toxic cyanobacteria, which are classified into several groups on ... | 2004 | 15072295 |
| biosynthesis of 4-methylproline in cyanobacteria: cloning of nose and nosf genes and biochemical characterization of the encoded dehydrogenase and reductase activities. | the biosynthesis of the unusual amino acid 4-methylproline in the nostoc genus of cyanobacteria was investigated on the genetic and enzymatic level. two genes involved in the biosynthesis were cloned and the corresponding enzymes, a zinc-dependent long-chain dehydrogenase and a delta(1)-pyrroline-5-carboxylic acid (p5c) reductase homologue, were overexpressed in escherichia coli and biochemically characterized. putative substrates were synthesized to test enzyme substrate specificities, and deut ... | 2003 | 12515465 |
| relation between domain evolution, specificity, and taxonomy of the alpha-amylase family members containing a c-terminal starch-binding domain. | the alpha-amylase family (glycoside hydrolase family 13; gh 13) contains enzymes with approximately 30 specificities. six types of enzyme from the family can possess a c-terminal starch-binding domain (sbd): alpha-amylase, maltotetraohydrolase, maltopentaohydrolase, maltogenic alpha-amylase, acarviose transferase, and cyclodextrin glucanotransferase (cgtase). such enzymes are multidomain proteins and those that contain an sbd consist of four or five domains, the former enzymes being mainly hydro ... | 2003 | 12581203 |
| cloning and expression of a putative cyclodextrin glucosyltransferase from the symbiotically competent cyanobacterium nostoc sp. pcc 9229. | a polymerase chain reaction-based method was used to isolate a nostoc sp. pcc 9229 cdna from infected glands of gunnera chilensis. the complete gene sequence was isolated from a genomic nostoc sp. pcc 9229 library. sequence analysis showed 84% amino acid similarity to a putative cyclodextrin glycosyltransferase from nostoc sp. pcc 7120 and the gene was therefore termed cgt. southern blot revealed that the cgt gene was present in symbiotically competent cyanobacteria. the cgt gene was expressed i ... | 2003 | 12620618 |
| raman spectroscopic detection of biomolecular markers from antarctic materials: evaluation for putative martian habitats. | the vital uv-protective and photosynthetic pigments of cyanobacteria and lichens (microbial symbioses) that dominate primary production in antarctic desert ecosystems auto-fluoresce at short-wavelengths. a long wavelength (1064 nm) near infra-red laser has been used for non-intrusive raman spectroscopic analysis of their ecologically significant compounds. there is now much interest in the construction of portable raman systems for the analysis of cyanobacterial and lichen communities in the fie ... | 2003 | 12909141 |
| unusual water flux in the extracellular polysaccharide of the cyanobacterium nostoc commune. | the speed of water uptake by desiccated nostoc commune was found to depend upon the duration of desiccation. the rehydration of desiccated colonies led to marked, time-dependent changes in structure and ultrastructure and fluctuations in the composition of the transcriptome. physical evaporative water loss is an active process that was influenced by inhibitors of transcription and translation. | 2003 | 12957961 |
| [the accumulation and degradation dynamics of cyanophycin in cyanobacteria grown in symbiotic associations with plant tissues and cells]. | five different artificial associations of cyanobacterial cells with the cells or tissues of nightshade and rauwolfia were studied. the associations grown on nitrogen-containing media produced heterocysts. cyanobacterial cells in the associations retained their ability to take up bound nitrogen from the medium, to store it in the form of cyanophycin granules, and to use them in the process of symbiotic growth. the synthesis and degradation of cyanophycin granules in cyanobacterial cells were more ... | 2003 | 12901011 |
| commercial development of microalgal biotechnology: from the test tube to the marketplace. | while humans have taken limited advantage of natural populations of microalgae for centuries (nostoc in asia and spirulina in africa and north america for sustenance), it is only recently that we have come to realize the potential of microalgal biotechnology. microalgal biotechnology has the potential to produce a vast array of products including foodstuffs, industrial chemicals, compounds with therapeutic applications and bioremediation solutions from a virtually untapped source. from an indust ... | 2003 | 12919832 |
| differentiation of nostoc flagelliforme and its neighboring species using fatty-acid profiling as a chemotaxonomic tool. | in this study, fatty-acid content and patterns were analyzed in order to distinguish nostoc flagelliforme, an edible terrestrial cyanobacterium, from other nostoc species and representatives typical of its close neighbors (genera anabaena, microcystis, and synechococcus). according to the kenyon-murata classification system, all the nostoc species were assigned to group ii due to the presence of c18:2n3 and c18:3n3, and the absence of c18:3n6. hierarchical cluster analysis was also employed to s ... | 2003 | 14756530 |
| a two-component regulator of universal stress protein expression and adaptation to oxygen starvation in mycobacterium smegmatis. | we identified a response regulator in mycobacterium smegmatis which plays an important role in adaptation to oxygen-starved stationary phase. the regulator exhibits strong sequence similarity to devr/rv3133c of m. tuberculosis. the structural gene is present on a multigene locus, which also encodes a sensor kinase. a devr mutant of m. smegmatis was adept at surviving growth arrest initiated by either carbon or nitrogen starvation. however, its culturability decreased several orders of magnitude ... | 2003 | 12591871 |
| cyanovirin-n: a sugar-binding antiviral protein with a new twist. | cyanovirin-n (cv-n), an 11-kda protein from the cyanobacterium nostoc ellipsosporum, is a highly potent virucidal agent that has generated interest as a lead natural product for the prevention and chemotherapy of human immunodeficiency virus infection. the antiviral activity of cv-n is mediated through specific, high-affinity interactions with the viral surface envelope glycoproteins. a number of structures of wild-type, mutant and sequence-shuffled cv-n have been solved by nuclear magnetic reso ... | 2003 | 12678493 |
| extracellular polysaccharide synthesis by nostoc strains as affected by n source and light intensity. | a study on the effect of two of the main factors affecting energy flux in n(2)-fixing cyanobacteria, i.e. light intensity and availability of combined nitrogen, on the synthesis of soluble exopolysaccharides was carried out with three strains of the genus nostoc (pcc 7413, pcc 7936, and pcc 8113) presenting different capsular polysaccharidic morphologies and released polysaccharide productions. strains acclimated to diazotrophic and non-diazotrophic conditions were cultured at high and low light ... | 2003 | 12697392 |
| pcr-based identification of microcystin-producing genotypes of different cyanobacterial genera. | microcystins are harmful hepatotoxins produced by many, but not all strains of the cyanobacterial genera anabaena, microcystis, anabaena, planktothrix, and nostoc. waterbodies have to be monitored for the mass development of toxic cyanobacteria; however, because of the close genetic relationship of microcystin-producing and non-producing strains within a genus, identification of microcystin-producers by morphological criteria is not possible. the genomes of microcystin-producing cells contain mc ... | 2003 | 14551674 |
| slr2013 is a novel protein regulating functional assembly of photosystem ii in synechocystis sp. strain pcc 6803. | the synechocystis sp. strain pcc 6803, which has a t192h mutation in the d2 protein of photosystem ii, is an obligate photoheterotroph due to the lack of assembled photosystem ii complexes. a secondary mutant, rg2, has been selected that retains the t192h mutation but is able to grow photoautotrophically. restoration of photoautotrophic growth in this mutant was caused by early termination at position 294 in the slr2013 protein. the t192h mutant with truncated slr2013 forms fully functional phot ... | 2003 | 14594835 |
| anabaena sp. strain pcc 7120 hety gene influences heterocyst development. | the filamentous cyanobacterium anabaena (nostoc) sp. strain pcc 7120 responds to starvation for fixed nitrogen by producing a semiregular pattern of nitrogen-fixing cells called heterocysts. overexpression of the hety gene partially suppressed heterocyst formation, resulting in an abnormal heterocyst pattern. inactivation of hety increased the time required for heterocyst maturation and caused defects in heterocyst morphology. the 489-bp hety gene (alr2300), which is adjacent to pats (asl2301), ... | 2003 | 14617665 |
| the cyanobiont in an azolla fern is neither anabaena nor nostoc. | the cyanobacterial symbionts in the fern azolla have generally been ascribed to either the anabaena or nostoc genera. by using comparisons of the sequences of the phycocyanin intergenic spacer and a fragment of the 16s rrna, we found that the cyanobiont from an azolla belongs to neither of these genera. | 2003 | 14659541 |
| prokaryotic origins for the mitochondrial alternative oxidase and plastid terminal oxidase nuclear genes. | the mitochondrial alternative oxidase is a diiron carboxylate quinol oxidase (dox) found in plants and some fungi and protists, but not animals. the plastid terminal oxidase is distantly related to alternative oxidase and is most likely also a dox protein. database searches revealed that the alpha-proteobacterium novosphingobium aromaticivorans and the cyanobacteria nostoc sp. pcc7120, synechococcus sp. wh8102 and prochlorococcus marinus subsp. pastoris ccmp1378 each possess a dox homolog. each ... | 2003 | 14675750 |
| molecular characterization of endolithic cyanobacteria inhabiting exposed dolomite in central switzerland. | the phototrophic microbial community inhabiting exposed dolomite in the alpine piora valley (switzerland) forms a distinct endolithic bilayer that features adjacent red dolomite (exterior) and green dolomite (interior) layers that are c. 0.5-1 mm below the rock surface. characterization of the community, with an emphasis on cyanobacteria, was conducted with culture-dependent and -independent approaches. direct microscopy of green dolomite revealed four distinct morphotypes consistent with chloro ... | 2003 | 12823194 |
| lateral gene transfer and ancient paralogy of operons containing redundant copies of tryptophan-pathway genes in xylella species and in heterocystous cyanobacteria. | tryptophan-pathway genes that exist within an apparent operon-like organization were evaluated as examples of multi-genic genomic regions that contain phylogenetically incongruous genes and coexist with genes outside the operon that are congruous. a seven-gene cluster in xylella fastidiosa includes genes encoding the two subunits of anthranilate synthase, an aryl-coa synthetase, and trpr. a second gene block, present in the anabaena/nostoc lineage, but not in other cyanobacteria, contains a near ... | 2003 | 12620124 |
| demonstration of a sensory rhodopsin in eubacteria. | we report the first sensory rhodopsin observed in the eubacterial domain, a green light-activated photoreceptor in anabaena (nostoc) sp. pcc7120, a freshwater cyanobacterium. the gene encoding the membrane opsin protein of 261 residues (26 kda) and a smaller gene encoding a soluble protein of 125 residues (14 kda) are under the same promoter in a single operon. the opsin expressed heterologously in escherichia coli membranes bound all-trans retinal to form a pink pigment (lambda max 543 nm) with ... | 2003 | 12622809 |
| a two-component system mediates developmental regulation of biosynthesis of a heterocyst polysaccharide. | some cyanobacteria couple oxygenic photosynthesis in vegetative cells with o2-sensitive n2 fixation in differentiated cells called heterocysts. heterocyst differentiation involves extensive biochemical and structural changes that collectively permit heterocysts to assimilate n2 aerobically and supply the products of n2 fixation to vegetative cells. hepk and devr are required for the development of functional heterocysts in anabaena and nostoc, respectively. we show that hepk is an autokinase and ... | 2003 | 12637541 |
| heterocyst-specific expression of patb, a gene required for nitrogen fixation in anabaena sp. strain pcc 7120. | the patb gene product is required for growth and survival of the filamentous cyanobacterium anabaena sp. strain pcc 7120 in the absence of combined nitrogen. a patb::gfp fusion demonstrated that this gene is expressed exclusively in heterocysts. patb mutants have a normal initial pattern of heterocyst spacing along the filament but differentiate excess heterocysts after several days in the absence of combined nitrogen. expression of hetr and pats, two critical regulators of the heterocyst develo ... | 2003 | 12644502 |
| genetic polymorphism of cyanobacteria under permanent natural stress: a lesson from the "evolution canyons". | cyanobacteria have high adaptive potential and occur in the most extreme habitats. the available literature data indicate that the versatility of cyanobacteria is related to their higher polymorphism under stress. the studies of a filamentous cyanobacterium, nostoc linckia, from the ecological microsite models known as "evolution canyons" showed that, among the evolutionary forces maintaining the higher polymorphism and genome diversity under permanent natural stress, the various types of natura ... | 2003 | 12648721 |
| [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 |
| presence and expression of hydrogenase specific c-terminal endopeptidases in cyanobacteria. | hydrogenases catalyze the simplest of all chemical reactions: the reduction of protons to molecular hydrogen or vice versa. cyanobacteria can express an uptake, a bidirectional or both nife-hydrogenases. maturation of those depends on accessory proteins encoded by hyp-genes. the last maturation step involves the cleavage of a ca. 30 amino acid long peptide from the large subunit by a c-terminal endopeptidase. until know, nothing is known about the maturation of cyanobacterial nife-hydrogenases. ... | 2003 | 12735794 |
| effect of three nitrophenols on carbon metabolism in nostoc muscorum and chlorella vulgaris. | carbon metabolism in selected strains of nostoc muscorum and chlorella vulgaris grown in the presence of three nitrophenols [o-nitrophenol, m-nitrophenol and 2,4-dinitrophenol] was assessed by examining activities of the enzymes such as amylase, starch phosphorylase, fructose 1,6-biphosphatase, sucrose phosphate synthase, and invertase. marked alterations were observed in activities of the enzymes involved in starch metabolism. the cellular content of starch in nitrophenol-grown cultures was sig ... | 2003 | 12742367 |
| ultrastructure of the cyanobacterium nostoc muscorum and exploitation of the culture for hydrogen production. | an effect of various physico-chemical parameters on nitrogenase-catalyzed oxygen-free hydrogen production by nostoc muscorum was demonstrated. more hydrogen was produced in the light than in the dark. optimum temperature was 40 degrees c various sugars increased hydrogen production whereas on easily metabolized nitrogen sources it was inhibited. the production was sensitive to salinity and fe3+, cu2+, zn2+ and ni2+ ions. ultrastructural study revealed many electron-dense layers outside the cell- ... | 2003 | 12744079 |
| fatty acid composition of six freshwater wild cyanobacterial species. | hydroxy, n-saturated, branched, dioic, and unsaturated fatty acids in six freshwater wild cyanobacteria (chroococcus minutus, lyngbya ceylanica, merismopedia glauca, nodularia sphaerocarpa, nostoc linckia, and synechococcus aeruginosus) collected from different lakes and springs of israel have been identified by gas chromatography-mass spectrometry (gc-ms). | 2003 | 12744080 |
| protective role of certain chemicals against uv-b-induced damage in the nitrogen-fixing cyanobacterium, nostoc muscorum. | the protective effects of l-cysteine, ascorbic acid, reduced glutathione, l-tryptophan, and sodium pyruvate against uv-b-induced damages were studied in the nitrogen-fixing cyanobacterium, nostoc muscorum. when added to the culture suspension during uv-b treatment, these chemicals caused a significant protective effect on survival and growth of the organism. sodium pyruvate conferred the strongest protection whereas the weakest effect was elicited by tryptophan. a 20 min exposure of a culture su ... | 2003 | 12746856 |
| [role of the heterotrophic bacteria associated with the cyanobacterium nostoc muscorum in cadmium sulfide synthesis]. | 2003 | 12751257 | |
| mutational engineering of the cyanobacterium nostoc muscorum for resistance to growth-inhibitory action of licl and nacl. | the effect of nacl on two vital processes of cyanobacterial metabolism, viz. n(2) fixation and oxygenic photosynthesis, was studied in the cyanobacterium nostoc muscorum grown diazotrophically. an increase in nacl concentration suppressed the formation of heterocyst and adversely affected the nitrogenase activity in the parent, whereas in li(+)-r and na(+)-r mutants nacl stress did not cause any adverse effect. the rate of photosynthetic o(2)-evolution was also adversely affected by the nacl str ... | 2003 | 12783185 |
| sequence analysis and biochemical characterization of the nostopeptolide a biosynthetic gene cluster from nostoc sp. gsv224. | the cloning, sequencing, annotation and biochemical analysis of the nostopeptolide (nos) biosynthetic gene cluster from the terrestrial cyanobacterium nostoc sp. gsv224 is described. nostopeptolides a1 and a2 are cyclic peptide-polyketide hybrid natural products possessing nine amino acid residues, a butyric acid group, and an internal acetate-derived unit that are linked by peptide and ester bonds. the nos gene cluster includes eight orfs encompassing 40 kb and includes most of the genes predic ... | 2003 | 12853152 |
| plma, a new member of the gntr family, has plasmid maintenance functions in anabaena sp. strain pcc 7120. | the filamentous cyanobacterium anabaena (nostoc) sp. strain pcc 7120 maintains a genome that is divided into a 6.4-mb chromosome, three large plasmids of more that 100 kb, two medium-sized plasmids of 55 and 40 kb, and a 5.5-kb plasmid. plasmid copy number can be dynamic in some cyanobacterial species, and the genes that regulate this process have not been characterized. here we show that mutations in an open reading frame, all1076, reduce the numbers of copies per chromosome of several plasmids ... | 2003 | 12867439 |
| lipid metabolism in cultured lichen photobionts with different phosphorus status. | lipid metabolism was studied in different photobiont species from lichens by following incorporation of radiolabel from [1-14c]acetate. in four algal photobionts, coccomyxa mucigena, c. peltigera variolosae, trebouxia aggregata, t. erici, polar lipids were mainly (73-90%) labelled while triacylglycerols were the most highly labelled non-polar lipid class. a rhamnose-containing lipid was found in two coccomyxa species, representing about 11% of the polar lipids of c. mucigena. all the major algal ... | 2003 | 12946419 |
| biodiversity of algae and protozoa in a natural waste stabilization pond: a field study. | a field study was carried out on the biodiversity of protozoa and algae from a natural waste stabilization pond during november, 1996 to april, 1997. the raw waste and pond samples were analysed for physico-chemical and biological parameters. high dissolved oxygen (do) coinciding with phytoplankton peak was recorded. the algae--chlorella vulgaris, scenedesmus acuminatus, oscillatoria brevis and nostoc piscinale and protozoa--paramecium caudatum, acanthamoeba sp., bodo saltans and oikomonas termo ... | 2003 | 12974463 |
| wavelength-dependent induction of a mycosporine-like amino acid in a rice-field cyanobacterium, nostoc commune: role of inhibitors and salt stress. | wavelength-dependent induction of a mycosporine-like amino acid (maa) was studied in a nitrogen-fixing rice-field cyanobacterium, nostoc commune. hplc studies showed the presence of shinorine, a bisubstituted maa containing both glycine and serine groups and having an absorption maximum at 334 nm. exposure of cultures to simulated solar radiation in combination with various cut-off filters (wg 280, 295, 305, 320, 335, 345, gg 400, 420, 455, 475, og 515, 530, 570, rg 645, 665; all schott filter s ... | 2003 | 12664980 |
| bioactivities of nostocine a produced by a freshwater cyanobacterium nostoc spongiaeforme tistr 8169. | a freshwater cyanobacterium, nostoc spongiaeforme tistr 8169, synthesizes and releases a violet pigment, nostocine a, into medium. we examined the bioactivity of nostocine a to several model organisms breeding with n. spongiaeforme in the natural environment. to microalgae, nostocine a exhibited growth inhibitory activity comparable to paraquat, and the activity tended to be stronger to green algae than to cyanobacteria. nostocine a also exhibited strong inhibitory activity to the root elongatio ... | 2003 | 16233448 |
| cell differentiation and colony alteration of an edible terrestrial cyanobacterium nostoc flagelliforme, in liquid suspension cultures. | morphological characteristics of an edible terrestrial cyanobacterium nostoc flagelliforme in liquid suspension cultures under photoautotrophic conditions are presented. different cell forms alternated in a regular manner during the experimentation period (30 d). n. flagelliforme exhibited a very complex life cycle in terms of colony morphology, including mainly 4 different colony morphological forms, viz. hormogonia, filaments, seriate colonies and aseriate colonies. under laboratory conditions ... | 2003 | 14976718 |
| phylogenetic analysis of symbiotic and free-living cyanobacterial cultures using dna amplification fingerprinting. | dna amplification fingerprinting (daf) of 17 cyanobacterial isolates belonging to symbiotic and free-living forms of 6 different genera was done. the dendrogram analysis of 17 cyanobacterial cultures revealed three major clusters. all westiellopsis cultures formed the first major cluster and their nucleotide relatedness ranged between 71-93%. in the second major cluster, the symbiotic cyanobacterium anabaena sp dominated and all anabaena cultures showed 60-75% similarity with each other. nostoc ... | 2003 | 15248486 |
| horizontal gene transfer of "prototype" nramp in bacteria. | eukaryotic nramp genes encode divalent metal ion permeases important for nutrition and resistance to microbial infection. bacterial homologs encode proton-dependent transporters of manganese (mnth), and other divalent metal ions. bacterial mnth were classified in three homology groups (a, b, c) and mnth c further subdivided in calpha, cbeta, cgamma. the proteins from c. tepidum (mnth b) and e. faecalis (mnth cbeta1, 2), divergent in sequence and hydropathy profile, conferred increased metal sens ... | 2003 | 14708570 |
| dna binding properties of the hrmr protein of nostoc punctiforme responsible for transcriptional regulation of genes involved in the differentiation of hormogonia. | nostoc punctiforme is an example of a filamentous cyanobacterium that is capable of differentiating non-growing cells that constitute gliding filaments termed hormogonia. these gliding filaments serve in short distance dispersal and as infective units in establishing a symbiosis with plants, such as the bryophyte anthoceros punctatus. mutants of n. punctiforme exist which show elevated levels of initial infection of a. punctatus as a consequence of repeated cycles of hormogonium differentiation. ... | 2003 | 12519206 |
| genomic dna of nostoc commune (cyanobacteria) becomes covalently modified during long-term (decades) desiccation but is protected from oxidative damage and degradation. | genomic dna of nostoc commune (cyanobacteria) became covalently modified during decades of desiccation. amplification of gene loci from desiccated cells required pretreatment of dna with n-phenacylthiazolium bromide, a reagent that cleaves dna- and protein-linked advanced glycosylation end-products. dna from 13 year desiccated cells did not show any higher levels of the commonly studied oxidatively modified dna damage biomarkers 8-hydroxyguanine, 8-hydroxyadenine and 5-hydroxyuracil, compared to ... | 2003 | 12799425 |
| solution nmr structure and backbone dynamics of the psae subunit of photosystem i from synechocystis sp. pcc 6803. | psae is a small peripheral subunit of photosystem i (psi) that is very accessible to the surrounding medium. it plays an essential role in optimizing the interactions with the soluble electron acceptors of psi, ferredoxin and flavodoxin. the solution structure of psae from the cyanobacterium synechocystis sp. pcc 6803 has been investigated by nmr with a special emphasis on its protein dynamic properties. psae is characterized by a well-defined central core that consists of a five-stranded beta-s ... | 2002 | 12437347 |
| toxicity of a rice field herbicide in some nitrogen-fixing algae. | the incorporation of diquat into cultures of nostoc muscorum and cylindrospermum sp. proved to be highly toxic. the range of various concentrations employed varies from 1 microgram/ml 15 micrograms/ml. relatively higher does (above 5 micrograms/ml) reduced the chlorophyll a content and a progressive decrease in algal growth and ultimately complete lysis of the cells was recorded with the increasing level of the herbicide. a concentration of 15 micrograms/ml has been found to be algicidal for bot ... | 2002 | 13677067 |
| [formation of giant and ultramicroscopic forms of nostoc muscorum calu 304 during cocultivation with rauwolfia tissues]. | the study of heteromorphic nostoc muscorum calu 304 cells, whose formation was induced by 6- to 7-week cocultivation with the rauwolfia callus tissues under unfavorable conditions, revealed the occurrence of giant cell forms (gcfs) with a volume which was 35-210 times greater than that of standard cyanobacterial cells. some gcfs had an impaired structure of the murein layer of the cell wall, which resulted in the degree of impairment of the cell wall ranging from the mere loss of its rigidity to ... | 2002 | 12449632 |