Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| crystal structure of the glur0 ligand-binding core from nostoc punctiforme in complex with l-glutamate: structural dissection of the ligand interaction and subunit interface. | glur0 from nostoc punctiforme (npglur0) is a bacterial homologue of the ionotropic glutamate receptor (iglur). we have solved the crystal structure of the ligand-binding core of npglur0 in complex with l-glutamate at a resolution of 2.1 a. the structure exhibits a noncanonical ligand interaction and two distinct subunit interfaces. the side-chain guanidium group of arg80 forms a salt bridge with the gamma-carboxyl group of bound l-glutamate: in glur0 from synechocystis (sglur0) and other iglurs, ... | 2008 | 18164033 |
| [studies on evaluation of natural products for antiviral effects and their applications]. | in the search for novel antiviral molecules from natural products, we have discovered various antiviral molecules with characteristic mechanisms of action. scopadulciol (sdc), isolated from the tropical medicinal plant scoparia dulcis l., showed stimulatory effects on the antiviral potency of acyclovir (acv) or ganciclovir (gcv). this effect of sdc was exerted via the activation of viral thymidine kinase (hsv-1 tk) and, as a result, an increase in the cellular concentration of the active form of ... | 2008 | 18176057 |
| the odd behaviour of carbonic anhydrase in the terrestrial cyanobacterium nostoc flagelliforme during hydration-dehydration cycles. | the terrestrial cyanobacterium nostoc flagelliforme, inhabiting arid areas, withstands prolonged periods of dehydration. how dehydration and occasional wetting affect inorganic c acquisition in this organism is not well known. as inorganic c acquisition in cyanobacteria often involves carbonic anhydrases (ca), we studied the effect of cycles of hydration and dehydration on the extracellular and intracellular ca activities, at the ph values presumably associated with dew or rain wetting. the exte ... | 2008 | 18177372 |
| identification of hepatotoxin-producing cyanobacteria by dna-chip. | we developed a new tool to detect and identify hepatotoxin-producing cyanobacteria of the genera anabaena, microcystis, planktothrix, nostoc and nodularia. genus-specific probe pairs were designed for the detection of the microcystin (mcye) and nodularin synthetase genes (ndaf) of these five genera to be used with a dna-chip. the method couples a ligation detection reaction, in which the polymerase chain reaction (pcr)-amplified mcye/ndaf genes are recognized by the probe pairs, with a hybridiza ... | 2008 | 18190512 |
| quorum quenching activity in anabaena sp. pcc 7120: identification of aiic, a novel ahl-acylase. | many bacteria use quorum sensing (qs) to coordinate responses to environmental changes. in gram-negative bacteria, the most extensively studied qs systems rely on the use of n-acylhomoserine lactones (ahls) signal molecules. some bacteria produce enzymes that are able to inactivate ahl signals produced by other bacteria and hence interfere with qs-mediated processes via a phenomenon known as quorum quenching. acylase-type ahl degradation activity has been found in the biomass of the filamentous ... | 2008 | 18194337 |
| effects of nitrogen source on the synthesis of the uv-screening compound, scytonemin, in the cyanobacterium nostoc punctiforme pcc 73102. | the effects of nitrogen source (n(2), no(3)(-) and nh(4)(+)) on scytonemin synthesis were investigated in the heterocystous cyanobacterium nostoc punctiforme pcc 73102. with the required uva radiation included, nostoc synthesized three to seven times more scytonemin while fixing nitrogen than when utilizing nitrate or ammonium. a similar increase in scytonemin synthesis occurred when nitrate or ammonium became depleted by growth and nostoc switched to diazotrophic metabolism with the differentia ... | 2008 | 18218026 |
| genes of cyanobacterial origin in plant nuclear genomes point to a heterocyst-forming plastid ancestor. | plastids are descended from a cyanobacterial symbiosis which occurred over 1.2 billion years ago. during the course of endosymbiosis, most genes were lost from the cyanobacterium's genome and many were relocated to the host nucleus through endosymbiotic gene transfer (egt). the issue of how many genes were acquired through egt in different plant lineages is unresolved. here, we report the genome-wide frequency of gene acquisitions from cyanobacteria in 4 photosynthetic eukaryotes--arabidopsis, r ... | 2008 | 18222943 |
| selectivity in the heavy metal removal by exopolysaccharide-producing cyanobacteria. | the aim of this study was to assess the selective removal of cu(ii), cr(iii) and ni(ii) by strains of exopolysaccharide (eps)-producing cyanobacteria, and to investigate the interaction of sorption in solutions with multiple-metals. | 2008 | 18248368 |
| isolation and characterization of thylakoid membranes from the filamentous cyanobacterium nostoc punctiforme. | nostoc punctiforme strain pasteur culture collection (pcc) 73102, a sequenced filamentous cyanobacterium capable of nitrogen fixation, is used as a model organism for characterization of bioenergetic processes during nitrogen fixation in nostoc. a protocol for isolating thylakoid membranes was developed to examine the biochemical and biophysical aspects of photosynthetic electron transfer. thylakoids were isolated from filaments of n. punctiforme by pneumatic pressure-drop lysis. the activity of ... | 2007 | 18251853 |
| mechanisms to avoid photoinhibition in a desiccation-tolerant cyanobacterium, nostoc commune. | a desiccation-tolerant cyanobacterium, nostoc commune, shows unique responses to dehydration. these responses are: (i) loss of psii activity in parallel with the loss of photosynthesis; (ii) loss of psi activity; and (iii) dissipation of light energy absorbed by pigment-protein complexes. in this study, the deactivation of psii is shown to be important in avoiding photoinhibition when the calvin-benson cycle is repressed by dehydration. furthermore, our evidence suggests that dissipation of ligh ... | 2008 | 18252733 |
| a common transport system for methionine, l-methionine-dl-sulfoximine (msx), and phosphinothricin (ppt) in the diazotrophic cyanobacterium nostoc muscorum. | we present evidence, for the first time, of the occurrence of a transport system common for amino acid methionine, and methionine/glutamate analogues l-methionine-dl-sulfoximine (msx) and phosphinothricin (ppt) in cyanobacterium nostoc muscorum. methionine, which is toxic to cyanobacterium, enhanced its nitrogenase activity at lower concentrations. the cyanobacterium showed a biphasic pattern of methionine uptake activity that was competitively inhibited by the amino acids alanine, isoleucine, l ... | 2008 | 18266032 |
| cyanobacteria-bryophyte symbioses. | cyanobacteria are a large group of photosynthetic prokaryotes of enormous environmental importance, being responsible for a large proportion of global co(2) and n(2) fixation. they form symbiotic associations with a wide range of eukaryotic hosts including plants, fungi, sponges, and protists. the cyanobacterial symbionts are often filamentous and fix n(2) in specialized cells known as heterocysts, enabling them to provide the host with fixed nitrogen and, in the case of non-photosynthetic hosts ... | 2008 | 18267939 |
| nitrogen fixation by phyllosphere bacteria associated with higher plants and their colonizing epiphytes of a tropical lowland rainforest of costa rica. | leaf surfaces (phyllospheres) have been shown to provide appropriate conditions for colonization by microorganisms including diazotrophic bacteria that are able to fix atmospheric nitrogen (n(2)). in this study, we determined leaf-associated n(2) fixation of a range of rainforest plants in costa rica, under different environmental conditions, by tracing biomass n incorporation from (15)n(2). n(2)-fixing bacterial communities of the plant species carludovica drudei, grias cauliflora and costus la ... | 2008 | 18273066 |
| sequestration of chromium by exopolysaccharides of nostoc and gloeocapsa from dilute aqueous solutions. | this article reports the chromium removal potential of exopolysaccharides (eps) of two indigenously isolated cyanobacterial strains, gloeocapsa calcarea and nostoc punctiforme. the biosorption was studied by varying ph from 2 to 6 and initial chromium concentration from 5 to 20mg/l to find out the optimized conditions for maximum chromium removal by eps. two equilibrium models, langmuir and freundlich, were used to explain these results. the freundlich model was found to be better applicable to ... | 2008 | 18280649 |
| excision of the nifd element in the heterocystous cyanobacteria. | heterocyst differentiation in cyanobacteria is accompanied by developmentally regulated dna rearrangements that occur within the nifd, fdxn, and hupl genes. these genetic elements are excised from the genome by site-specific recombination during the latter stages of differentiation. the nifd element is excised by the recombinase, xisa, located within the element. our objective was to examine the xisa-mediated excision of the nifd element. to accomplish this, we observed the ability of xisa to ex ... | 2008 | 18283436 |
| lipid extract of nostoc commune var. sphaeroides kutzing, a blue-green alga, inhibits the activation of sterol regulatory element binding proteins in hepg2 cells. | nostoc commune var. sphaeroides kützing (n. commune), a blue-green alga, has been used as both a food ingredient and in medicine for centuries. to determine the effect of n. commune on cholesterol metabolism, n. commune lipid extract was incubated at increasing concentrations (25-100 mg/l) with hepg2 cells, a human hepatoma cell line. the addition of n. commune lipid extract markedly reduced mrna abundance of 3-hydroxy-3-methylglutaryl-coa reductase (hmgr) and ldl receptor (ldlr) (p < 0.05), wit ... | 2008 | 18287352 |
| identification and quantification of microcystins from a nostoc muscorum bloom occurring in oukaïmeden river (high-atlas mountains of marrakech, morocco). | health risks generated by cyanobacterial toxins in drinking and recreational waters are clearly recognised. during the monitoring programme on the distribution of toxic freshwater cyanobacteria in various water bodies including reservoirs, ponds and rivers of morocco, many toxigenic cyanobacteria bloom-forming species have been identified. particular attention was given to the investigation of the toxicology of a benthic nostoc species-nostoc muscorum ag. (cyanobacteria, nostocales, nostocaceae) ... | 2009 | 18288580 |
| quantitative shotgun proteomics of enriched heterocysts from nostoc sp. pcc 7120 using 8-plex isobaric peptide tags. | the filamentous cyanobacterium nostoc sp. strain pcc 7120 is capable of fixing atmospheric nitrogen. the labile nature of the core process requires the terminal differentiation of vegetative cells to form heterocysts, specialized cells with altered cellular and metabolic infrastructure to mediate the n2-fixing process. we present an investigation targeting the cellular proteomic expression of the heterocysts compared to vegetative cells of a population cultured under n2-fixing conditions. new 8- ... | 2008 | 18290607 |
| 5s rrna-recognition module of ctc family proteins and its evolution. | the effects of amino acid replacements in the rna-binding sites of homologous ribosomal proteins tl5 and l25 (members of the ctc family) on ability of these proteins to form stable complexes with ribosomal 5s rna were studied. it was shown that even three simultaneous replacements of non-conserved amino acid residues by alanine in the rna-binding site of tl5 did not result in noticeable decrease in stability of the tl5-5s rrna complex. however, any replacement among five conserved residues in th ... | 2008 | 18298371 |
| differential patterns of evolution and distribution of the symbiotic behaviour in nostocacean cyanobacteria. | many cyanobacteria commonly identified as belonging to the genus nostoc are well-known cyanobionts (symbionts) of a wide variety of plants and fungi. they form symbioses with bryophytes, pteridophytes, gymnosperms and angiosperms that are considerably different in the type of reciprocal interaction between the host and the cyanobiont. the phylogenetic and taxonomic relationships among cyanobionts isolated from different hosts and nostoc strains isolated from free-living conditions are still not ... | 2008 | 18319454 |
| biosorption of lead(ii) from aqueous solutions by non-living algal biomass oedogonium sp. and nostoc sp.--a comparative study. | industrial wastewaters containing heavy metals pose a major environmental problem that needs to be remedied. the present study reports the ability of two non-living (dried) fresh water algae, oedogonium sp. and nostoc sp. to remove lead(ii) from aqueous solutions in batch system under varying range of ph (2.99-7.04), contact time (5-300 min), biosorbent dose (0.1-0.8 g/l), and initial metal ion concentrations (100 and 200mg/l). the optimum conditions for lead biosorption are almost same for the ... | 2008 | 18321684 |
| genetic diversity in cyanobacterial symbionts of thalloid bryophytes. | two species of thalloid liverworts, blasia pusilla and cavicularia densa, form stable symbioses with nitrogen-fixing cyanobacteria. both bryophytes promote the persistence of their cyanobacterial associations by producing specialized gemmae, which facilitate the simultaneous dispersal of the host and its nitrogen-fixing symbionts. here the genetic diversity of cyanobacterial symbionts of blasia and cavicularia is examined. the results indicate that the primary symbionts of both bryophytes are cl ... | 2008 | 18325923 |
| analysis of the cryptophycin p450 epoxidase reveals substrate tolerance and cooperativity. | cryptophycins are potent anticancer agents isolated from nostoc sp. atcc 53789 and nostoc sp. gsv 224. the most potent natural cryptophycin analogues retain a beta-epoxide at the c2'-c3' position of the molecule. a p450 epoxidase encoded by c rpe recently identified from the cryptophycin gene cluster was shown to install this key functional group into cryptophycin-4 (cr-4) to produce cryptophycin-2 (cr-2) in a regio- and stereospecific manner. here we report a detailed characterization of the cr ... | 2008 | 18366166 |
| tyrosine-induced heterocyst division in nostoc muscorum. | heterocyst size variation in nostoc muscorum has been surveyed in the presence and absence of tyrosine. the heterocyst size exhibited two major peaks under both conditions but one of the peaks shifted towards larger size in tyrosine-containing medium. heterocysts of larger volume exhibited division in the latter medium which was not observed in medium lacking tyrosine. it is suggested that signals for cell division did not decay following differentiation of heterocyst in the presence of tyrosine ... | 1987 | 18425684 |
| properties of a mini 9r-lipoxygenase from nostoc sp. pcc 7120 and its mutant forms. | lipoxygenases (loxs) consist of a class of enzymes that catalyze the regio- and stereospecific dioxygenation of polyunsaturated fatty acids. current reports propose that a conserved glycine residue in the active site of r-lipoxygenases and an alanine residue at the corresponding position in s-lipoxygenases play a crucial role in determining the stereochemistry of the product. recently, a bifunctional lipoxygenase with a linoleate diol synthase activity from nostoc sp. pcc7120 with r stereospecif ... | 2008 | 18439634 |
| transcription of the extended hyp-operon in nostoc sp. strain pcc 7120. | the maturation of hydrogenases into active enzymes is a complex process and e.g. a correctly assembled active site requires the involvement of at least seven proteins, encoded by hypabcdef and a hydrogenase specific protease, encoded either by hupw or hoxw. the n2-fixing cyanobacterium nostoc sp. strain pcc 7120 may contain both an uptake and a bidirectional hydrogenase. the present study addresses the presence and expression of hyp-genes in nostoc sp. strain pcc 7120. | 2008 | 18442387 |
| [structure and antiviral activity of an acidic polysaccharide from an edible blue-green alga, nostoc flagelliforme]. | recently, the development of antiviral agents with novel mechanisms of action has been required since many types of infectious disease have become a serious problem in our society. in the present study, we isolated a novel acidic polysaccharide, nostoflan (nsf), from a terrestrial blue-green alga, nostoc flagelliforme, and examined its structure and antiviral activity. the sugar composition and methylation analyses of nsf revealed that it is mainly composed of (-->4)- d-glcp-(1-->, -->6,4)-d-glc ... | 2008 | 18451619 |
| production of the neurotoxin bmaa by a marine cyanobacterium. | diverse species of cyanobacteria have recently been discovered to produce the neurotoxic non-protein amino acid beta-methylamino-l-alanine (bmaa). in guam, bmaa has been studied as a possible environmental toxin in the diets of indigenous chamorro people known to have high levels of amyotrophic lateral sclerosis/ parkinsonism dementia complex (als/pdc). bmaa has been found to accumulate in brain tissues of patients with progressive neurodegenerative illness in north america. in guam, bmaa was fo ... | 2007 | 18463731 |
| genetic diversity among and within cultured cyanobionts of diverse species of azolla. | the cyanobionts isolated from 10 azolla accessions belonging to 6 species (azolla mexicana, a. microphylla, a. rubra, a. caroliniana, a. filiculoides, a. pinnata) were cultured under laboratory conditions and analyzed on the basis of whole cell protein profiles and molecular marker dataset generated using repeat sequence primers (strr(mod) and hiptg). the biochemical and molecular marker profiles of the cyanobionts were compared with those of the free-living cyanobacteria and symbiotic nostoc st ... | 2008 | 18481216 |
| in vitro characterization of a carotenoid cleavage dioxygenase from nostoc sp. pcc 7120 reveals a novel cleavage pattern, cytosolic localization and induction by highlight. | carotenoid oxygenases catalyse the cleavage of c-c double bonds forming apocarotenoids, a diverse group of compounds, including retinoids and the precursors of some phytohormones. some apocarotenoids, like beta-ionone (c(13)), are ecologically important volatiles released by plants and cyanobacteria. in this work, we elucidated the activity of the nostoccarotenoid cleavage dioxygenase (nosccd, previously named nsc1) using synthetic and cyanobacterial substrates. nosccd converted bicyclic and mon ... | 2008 | 18485074 |
| cyanobacteria (nostoc commune) used as a dietary item in the peruvian highlands produce the neurotoxic amino acid bmaa. | in the mountains of peru, globular colonies of nostoc commune (nostocales) are collected in the highland lakes by the indigenous people, who call them llullucha. they are consumed locally, traded for maize, or sold, eventually entering the folk markets of cusco and other neighboring cities. throughout highland peru, nostoc commune is highly salient as a seasonal dietary item, being eaten alone, or in picante -- a local stew -- and is said to be highly nutritious. nostoc commune has been known to ... | 2008 | 18495396 |
| mutation of a gene for thyroid transcription factor-1 (titf1) in a patient with clinical features of resistance to thyrotropin. | resistance to tsh (rtsh [mim 275200]) is a heterogeneous condition defined by variable degree of insensitivity to biologically active tsh. while this condition is classically caused by loss-of-function mutations of the tsh receptor gene (tshr), several patients have exhibited rtsh-like phenotype in the apparent absence of tshr mutations, and some of them have mutations of pax8 or gnas1. we identified a japanese boy with congenital hypothyroidism who suffered from recurrent lower respiratory infe ... | 2008 | 18506088 |
| [cyanobacterium nostoc paludosum kütz as a basis of creation of agriculturally useful microbial associations by the example of bacteria of the genus rhizobium]. | different species of rhizobium were successfully introduced into the extracellular slime of nostoc paludosum (kütz) elenk, strain 18; cyanobacteria did not eliminate them and exhibited no specificity to the introduced species. both partners were shown to exist in a self-sufficient manner in an artificial consortium, the stability of which is determined by the technology of growing the cultures in collections. cyanobacteria act as carriers of introduced satellites, providing contact with the inoc ... | 2008 | 18522330 |
| a novel photoactive gaf domain of cyanobacteriochrome anpixj that shows reversible green/red photoconversion. | we report the discovery of a novel cyanobacteriochrome, the green/red photoreceptor anpixj (all1069), isolated from the heterocyst-forming cyanobacterium anabaena (nostoc) sp. pcc 7120. cyanobacteriochromes are a recently emerging tetrapyrrole-based photoreceptor superfamily that are distantly related to the conventional red/far-red photoreceptor phytochromes (phys). the chromophore-binding domains of anpixj produced in cyanobacterial and escherichia coli cells both showed a reversible and full ... | 2008 | 18571200 |
| endosulfan induced biochemical changes in nitrogen-fixing cyanobacteria. | pesticide contamination in aquatic ecosystem including paddy fields is a serious global environmental concern. cyanobacteria are also affected by pesticides as non- target organism. for better exploitation of cyanobacteria as biofertiliser, it is indispensable to select tolerant strains along with understanding of their tolerance. three cyanobacterial strains viz. aulosira fertilissima, anabaena variabilis and nostoc muscorum were studied for their stress responses to an organochlorine pesticide ... | 2008 | 18584851 |
| very small mobile repeated elements in cyanobacterial genomes. | mobile dna elements play a major role in genome plasticity and other evolutionary processes, an insight gained primarily through the study of transposons and retrotransposons (generally approximately 1000 nt or longer). these elements spawn smaller parasitic versions (generally >100 nt) that propagate through proteins encoded by the full elements. highly repeated sequences smaller than 100 nt have been described, but they are either nonmobile or their origins are not known. we have surveyed the ... | 2008 | 18599681 |
| treatment of influenza a (h1n1) virus infections in mice and ferrets with cyanovirin-n. | cyanovirin-n (cv-n), a protein derived from nostoc ellipsosporum, neutralizes influenza virus infectivity by binding to specific high-mannose oligosaccharides (oligomannose-8 and -9) at glycosylation sites on the viral hemagglutinin ha1 subunit. mouse-adapted viruses lose sensitivity to cv-n due to ha1 mutations that eliminate these glycosylation sites. recently we created a hybrid (reassortant) influenza a/wsn/33 (h1n1) virus containing the ha gene of a/new caledonia/20/99 (h1n1) with an asp225 ... | 2008 | 18601954 |
| potent and selective antiplasmodial activity of the cyanobacterial alkaloid nostocarboline and its dimers. | the quaternary beta-carbolinium alkaloid nostocarboline from the cyanobacterium nostoc 78-12a and 10 bis-cationic dimeric derivatives were evaluated against four protozoan parasites and low micromolar values against trypanosoma brucei, submicromolar values against leishmania donovani and low nanomolar values against plasmodium falciparum k1 were determined. selectivity against rat myoblasts (l6 cells) was found to be up to >2500-fold. | 2008 | 18606541 |
| differential sensitivity of five cyanobacterial strains to ammonium toxicity and its inhibitory mechanism on the photosynthesis of rice-field cyanobacterium ge-xian-mi (nostoc). | effects of two fertilizers, nh(4)cl and kcl, on the growth of the edible cyanobacterium ge-xian-mi (nostoc) and four other cyanobacterial strains were compared at ph 8.3+/-0.2 and 25 degrees c. their growth was decreased by at least 65% at 10 mmol l(-1) nh(4)cl but no inhibitory effect was observed at the same level of kcl. meanwhile, the strains exhibited a great variation of sensitivity to nh(4)(+) toxicity in the order: ge-xian-mi>anabaena azotica fachb 118>microcystis aeruginosa fachb 905>m. ... | 2008 | 18640729 |
| identification of sesquiterpene synthases from nostoc punctiforme pcc 73102 and nostoc sp. strain pcc 7120. | cyanobacteria are a rich source of natural products and are known to produce terpenoids. these bacteria are the major source of the musty-smelling terpenes geosmin and 2-methylisoborneol, which are found in many natural water supplies; however, no terpene synthases have been characterized from these organisms to date. here, we describe the characterization of three sesquiterpene synthases identified in nostoc sp. strain pcc 7120 (terpene synthase ns1) and nostoc punctiforme pcc 73102 (terpene sy ... | 2008 | 18658271 |
| growth kinetics of 1-2 mm and 3-4 mm colonies of nostoc sphaeroides (cyanophyta) in outdoor culture. | nostoc sphaeroides kützing was cultivated in paddlewheel-driven raceway ponds and the growth kinetics of 1-2 mm and 3-4 mm colonies of n. sphaeroides was studied. the biomass productivities in 2.5 m(2) raceway ponds inoculated with 1-2 mm and 3-4 mm colonies were 5.2 and 0.25 g dry wt m(-2) d(-1), respectively. furthermore, differently sized colonies showed different relative water content, total soluble carbohydrates, chlorophyll a content and density of filaments. this is the first report on m ... | 2008 | 18661109 |
| only plant-type (glyk) glycerate kinases produce d-glycerate 3-phosphate. | d-glycerate kinases (gk) occur in three phylogenetically distinct classes. class ii gks produce glycerate 2-phosphate, while both class i gk and class iii gk (glyk) are thought to produce glycerate 3-phosphate. we report on the identification of a bacterial-type class i gk in the unicellular cyanobacterium synechocystis sp. strain pcc 6803 and of a plant-type glyk in the filamentous cyanobacterium nostoc sp. strain pcc 7120. the comparison with other prokaryotic and eukaryotic gks of both classe ... | 2008 | 18675808 |
| substrate specificities and availability of fucosyltransferase and beta-carotene hydroxylase for myxol 2'-fucoside synthesis in anabaena sp. strain pcc 7120 compared with synechocystis sp. strain pcc 6803. | to elucidate the biosynthetic pathways of carotenoids, especially myxol 2'-glycosides, in cyanobacteria, anabaena sp. strain pcc 7120 (also known as nostoc sp. strain pcc 7120) and synechocystis sp. strain pcc 6803 deletion mutants lacking selected proposed carotenoid biosynthesis enzymes and gdp-fucose synthase (wcag), which is required for myxol 2'-fucoside production, were analyzed. the carotenoids in these mutants were identified using high-performance liquid chromatography, field desorption ... | 2008 | 18708496 |
| effect of exogenous extracellular polysaccharides on the desiccation and freezing tolerance of rock-inhabiting phototrophic microorganisms. | two major stresses that threaten rock-inhabiting microbial communities are desiccation and freezing; both result in a loss of liquid water in the cells. the mechanisms necessary to tolerate these extremes may be similar, but are not well understood. in both cases extracellular polysaccharides (eps) seem to play an important role. this study examines whether the eps released by a rock-inhabiting phototroph can have a protective effect on other members of similar and neighboring microbial communit ... | 2008 | 18710394 |
| withdrawal. 'genetically modified cyanobacterium nostoc muscorum overproducing proline in response to salinity and osmotic stresses' by santosh bhargava (journal of biosciences, volume 31, no. 2, pages 265-272, june 2006). | 2008 | 18754157 | |
| morphological variability in selected heterocystous cyanobacterial strains as a response to varied temperature, light intensity and medium composition. | the effect of temperature, light and nutrient composition on morphological traits was determined in seven nostocacean cyanobacteria (anabaena planctonica, a. sphaerica var. conoidea, a. spiroides, aphanizomenon gracile, nostoc sp., scytonema sp., and tolypothrix sp.). their morphological variability was high but only some of the features showed changes reflecting varied growth conditions. the frequency of heterocyst occurrence decreased with increasing nitrogen concentration. within the range st ... | 2008 | 18759118 |
| dna microarray comparisons of plant factor- and nitrogen deprivation-induced hormogonia reveal decision-making transcriptional regulation patterns in nostoc punctiforme. | hormogonia are nongrowing filaments, motile by means of a gliding mechanism, that are produced by certain cyanobacteria. their differentiation is induced by positive and negative factors for growth, such as deprivation of combined nitrogen (nitrogen stress induction [nsi]). in nostoc punctiforme, they are also induced by the exudate (hormogonium-inducing factor [hif]) of a symbiotic plant partner. time course (0.5 to 24 h) transcription profiles were determined by dna microarray assays for hormo ... | 2008 | 18790872 |
| [purification and characterization of extracellular polysaccharides from nostoc flagelliforme]. | the extracellular polysaccharides (eps) of n. flagelliforme were purified by deae anion exchange chromatography and sephadex g100 gel filtration chromatography. and two main components named nfps1 and nfps2 were obtained respectively. the physico-chemical characteristics of nfps2 were analyzed and compared with nfps0, which was obtained from field colony of n. flagelliforme. these results showed that both of nfps2 and nfpso were composed of four monosaccharides: glucose, xylose, galactose and ma ... | 2008 | 18807987 |
| antibacterial, antifungal and cytotoxic activity of terrestrial cyanobacterial strains from serbia. | cyanobacteria are known to be a rich source of biologically active compounds some of which can have pharmaceutical importance. in this work we present the screening results of cyanobacterial strains for their antibacterial, antifungal, and cytotoxic activity. cyanobacterial strains were isolated from various soil types in province of vojvodina and central serbia, republic of serbia. the screening included 9 strains of anabaena and 9 strains of nostoc. both, extracellular products (from the cultu ... | 2008 | 18815758 |
| aerophytic cyanophyceae (cyanobacteria) from some cairo districts, egypt. | twenty three aerophytic blue-green algal species were isolated and identified from 5 districts in cairo, namely: nasr city, abassiya, downtown, maadi and tebbin. downtown contained the highest numbers of total algal species (13 species) during the study throughout the years 2004-2005 in comparison to other districts. the composition of aeroalgal taxa varied with seasonal changes. chroococcus limenticus, lyngbya lagerheimii, phormidium ambigum and schizothrix purpurascens have been isolated durin ... | 2008 | 18817259 |
| nbla, a key protein of phycobilisome degradation, interacts with clpc, a hsp100 chaperone partner of a cyanobacterial clp protease. | when cyanobacteria are starved for nitrogen, expression of the nbla protein increases and thereby induces proteolytic degradation of phycobilisomes, light-harvesting complexes of pigmented proteins. phycobilisome degradation leads to a color change of the cells from blue-green to yellow-green, referred to as bleaching or chlorosis. as reported previously, nbla binds via a conserved region at its c terminus to the alpha-subunits of phycobiliproteins, the main components of phycobilisomes. we demo ... | 2008 | 18818204 |
| chromium (vi) tolerance in two halotolerant strains of nostoc. | the present study reports on chromium (vi) tolerance of two cyanobacterial strains nostoc linckia and nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (vi) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. while phycobilins and carotenoids also increased in nostoc linckia with total dissolved salts (tds) as well as metal, a decline was ob ... | 2008 | 18831365 |
| widespread distribution and identification of eight novel microcystins in antarctic cyanobacterial mats. | the microcystin (mc) content and cyanobacterial community structure of antarctic microbial mat samples collected from 40 ponds, lakes, and hydroterrestrial environments were investigated. samples were collected from bratina island and four of the dry valleys, wright, victoria, miers, and marshall. enzyme-linked immunosorbent assays (elisas), liquid chromatography-mass spectrometry (lc-ms), and protein phosphatase 2a (pp-2a) inhibition assays resulted in the identification of low levels (1 to 16 ... | 2008 | 18849457 |
| new peptolides from the cyanobacterium nostoc insulare as selective and potent inhibitors of human leukocyte elastase. | eight new cyanopeptolins (insulapeptolides a-h) were obtained from the cyanobacterium nostoc insulare. their isolation was guided by their bioactivity toward the target enzyme human leukocyte elastase, molecular biological investigations, and maldi-tof analysis. these peptides are selective inhibitors of human leukocyte elastase with activities in the nanomolar range. insulapeptolide d was the most potent compound with an ic(50) value of 85 nm (k(i) value of 36 nm). | 2008 | 18924217 |
| new insights into the role of fur proteins: furb (all2473) from anabaena protects dna and increases cell survival under oxidative stress. | fur (ferric uptake regulator) is a prokaryotic transcriptional regulator that controls a large number of genes mainly related to iron metabolism. several fur homologues with different physiological roles are frequently found in the same organism. the genome of the filamentous cyanobacterium anabaena (nostoc) sp. pcc 7120 codes for three different fur genes. fura is an essential protein involved in iron homoeostasis that also modulates dinitrogen fixation. fura interacts with haem, impairing its ... | 2009 | 18945213 |
| screening for acetylcholinesterase inhibitory activity in cyanobacteria of the genus nostoc. | fifty-four cyanobacterial strains of the genus nostoc from different habitats were screened for acetylcholinesterase inhibitory activity. water-methanolic extracts from freeze-dried biomasses were tested for inhibitory activity using ellman's spectrophotometric method. acetylcholinesterase inhibitory activity higher than 90% was found in the crude extracts of nostoc sp. str. lukesova 27/97 and nostoc ellipsosporum rabenh. str. lukesova 51/91. extracts from nostoc ellipsosporum str. lukesova 52/9 ... | 2009 | 18951237 |
| the 2a resolution crystal structure of hetl, a pentapeptide repeat protein involved in regulation of heterocyst differentiation in the cyanobacterium nostoc sp. strain pcc 7120. | the hetl gene from the cyanobacterium nostoc sp. pcc 7120 encodes a 237 amino acid protein (25.6kda) containing 40 predicted tandem pentapeptide repeats. nostoc sp. pcc 7120 is a filamentous cyanobacterium that forms heterocysts, specialized cells capable of fixing atmospheric n(2) during nitrogen starvation in its aqueous environment. under these conditions, heterocysts occur in a regular pattern of approximately one out of every 10-15 vegetative cells. heterocyst differentiation is highly regu ... | 2009 | 18952182 |
| gobase: an organelle genome database. | the organelle genome database gobase, now in its 21st release (june 2008), contains all published mitochondrion-encoded sequences (approximately 913,000) and chloroplast-encoded sequences (approximately 250,000) from a wide range of eukaryotic taxa. for all sequences, information on related genes, exons, introns, gene products and taxonomy is available, as well as selected genome maps and rna secondary structures. recent major enhancements to database functionality include: (i) addition of an in ... | 2009 | 18953030 |
| an evaluation of four phylogenetic markers in nostoc: implications for cyanobacterial phylogenetic studies at the intrageneric level. | the success of some phylogenetic markers in cyanobacteria owes to the design of cyanobacteria-specific primers, but a few studies have directly investigated the evolution "behavior" of the loci. in this study, we performed a case study in nostoc to evaluate rpoc1, hetr, rbclx, and 16s rrna-trna(ile)-trna(ala)-23s rrna internal transcribed spacer (its) as phylogenetic markers. the results indicated that the gene trees of these loci are not congruent with the phylogeny based on 16s rrna gene. the ... | 2009 | 18972163 |
| the role of the c-terminal region of cyanophycin synthetase from nostoc ellipsosporum ne1 in its enzymatic activity and thermostability: a key function of glu(856). | the biosynthesis of cyanophycin granule polypeptides is catalyzed by cyanophycin synthetase, cpha. in this study, the role of the c-terminal region of cpha from nostoc ellipsosporum ne1, cpha(ne1), was analyzed using a tailor-made c-terminus truncated library. the expression level of truncated cpha(ne1) in e. coli depended on the stop codons that were used. the expression vector that had the amber stop codon tag produced more than twice amount of cpha(ne1) as a vector that contained the ochre co ... | 2009 | 18977318 |
| characterization of cyanobacterial carotenoid ketolase crtw and hydroxylase crtr by complementation analysis in escherichia coli. | the pathway from beta-carotene to astaxanthin is a crucial step in the synthesis of astaxanthin, a red antioxidative ketocarotenoid that confers beneficial effects on human health. two enzymes, a beta-carotene ketolase (carotenoid 4,4'-oxygenase) and a beta-carotene hydroxylase (carotenoid 3,3'-hydroxylase), are involved in this pathway. cyanobacteria are known to utilize the carotenoid ketolase crtw and/or crto, and the carotenoid hydroxylase crtr. here, we compared the catalytic functions of c ... | 2008 | 18987067 |
| characterization of a novel debranching enzyme from nostoc punctiforme possessing a high specificity for long branched chains. | a novel debranching enzyme from nostoc punctiforme pcc73102 (npde) exhibits hydrolysis activity toward both alpha-(1,6)- and alpha-(1,4)-glucosidic linkages. the action patterns of npde revealed that branched chains are released first, and the resulting maltooligosaccharides are then hydrolyzed. analysis of the reaction with maltooligosaccharide substrates labeled with (14)c-glucose at the reducing end shows that npde specifically liberates glucose from the reducing end. kinetic analyses showed ... | 2009 | 19010304 |
| bioinformatic and expression analyses of genes mediating zinc homeostasis in nostoc punctiforme. | zinc homeostasis was investigated in nostoc punctiforme. cell tolerance to zn(2+) over 14 days showed that zncl(2) levels above 22 microm significantly reduced cell viability. after 3 days in 22 microm zncl(2), ca. 12% of the zn(2+) was in an edta-resistant component, suggesting an intracellular localization. zinquin fluorescence was detected within cells exposed to concentrations up to 37 microm relative to 0 microm treatment. radiolabeled (65)zn showed zn(2+) uptake increased over a 3-day peri ... | 2009 | 19011078 |
| quantitative overview of n2 fixation in nostoc punctiforme atcc 29133 through cellular enrichments and itraq shotgun proteomics. | nostoc punctiforme atcc 29133 is a photoautotrophic cyanobacterium with the capacity to fix atmospheric n 2. its ability to mediate this process is similar to that described for nostoc sp. pcc 7120, where vegetative cells differentiate into heterocysts. quantitative proteomic investigations at both the filament level and the heterocyst level are presented using isobaric tagging technology (itraq), with 721 proteins at the 95% confidence interval quantified across both studies. observations from ... | 2009 | 19012430 |
| accumulation of exopolysaccharides in liquid suspension culture of nostoc flagelliforme cells. | the liquid suspension culture of dissociated nostoc flagelliforme cells was investigated. it was found that the growth rate of n. flagelliforme cells and the accumulation of exopolysaccharides (eps) increased prominently when nano(3) and kh(2)po(4) were added in the liquid bg-11culture medium though phosphate had little effect on eps yield for specific mass of cells. n. flagelliforme cells grew well at 25 degrees c and neutral ph, however, a lower or higher temperature and weak alkaline can prom ... | 2010 | 19018481 |
| novel thermostable glycosidases in the extracellular matrix of the terrestrial cyanobacterium nostoc commune. | the cyanobacterium nostoc commune is adapted to the terrestrial environment and forms a visible colony in which the cells are embedded in extracellular polysaccharides (epss), which play a crucial role in the extreme desiccation tolerance of this organism. when natural colonies were immersed in water, degradation of the colonies occurred within 2 days and n. commune cells were released into the water. the activities that hydrolyze glycoside bonds in various n. commune fractions were examined usi ... | 2008 | 19029765 |
| isolation and characterization of the gene associated with geosmin production in cyanobacteria. | geosmin is a secondary metabolite responsible for earthy tastes and odors in potable water supplies. geosmin continues to be a challenge to water utility management regimes and remains one of the most common causes of consumer complaints, as the taste of "dirty" water may suggest a failed disinfection regime and that the water may be unsafe to drink. although cyanobacteria have been reported to be largely responsible for these taste and odor events, the answer as to how or why geosmin is produce ... | 2008 | 19031897 |
| role of ntca, a cyanobacterial global nitrogen regulator, in the regulation of sucrose metabolism gene expression in anabaena sp. pcc 7120. | in the heterocyst-forming cyanobacterium anabaena sp. pcc 7120 (also known as nostoc sp. pcc 7120), it has been shown that spsb and susa, the genes coding for proteins related to sucrose synthesis and cleavage, respectively, exhibit converse expression regarding the nitrogen source. in the nitrogen-fixing filament, spsb expression is mostly localized to the heterocysts and susa is only expressed in vegetative cells. the aim of this work was to investigate the participation of ntca, a global nitr ... | 2009 | 19082579 |
| repression of proinflammatory gene expression by lipid extract of nostoc commune var sphaeroides kützing, a blue-green alga, via inhibition of nuclear factor-kappab in raw 264.7 macrophages. | we investigated whether lipid extract from a blue-green alga, n commune, modulates proinflammatory gene expression in raw 264.7 macrophages. the cells were incubated with n commune lipid extract (0-100 microg/ml) and subsequently activated by lps (100 ng/ml). quantitative real-time pcr analysis showed that mrna abundance of proinflammatory mediators, including tnf-alpha, cox-2, il-1beta, il-6, and inos, was significantly reduced by n commune lipid extract in a dose-dependent manner. secretion of ... | 2008 | 19083393 |
| crystal structure of npun_r1517, a putative negative regulator of heterocyst differentiation from nostoc punctiforme pcc 73102. | 2009 | 19089958 | |
| biological control of faba bean pathogenic fungi by three cyanobacterial filtrates. | the aim of the present study is to evaluate the biological control aptitude of the cyanobacteria, anabaena subcylindrica, nostoc muscorum and oscillatoria angusta filtrates on the growth of the isolated pathogenic fungi from the different organs of faba bean. three caynobacterial (anabaena subcylindrica, nostoc muscorum and oscillatoria angusta) filtrates were prepared in different concentrations and their effects on the isolated pathogenic fungi from leaves, stems and roots of faba bean were st ... | 2007 | 19090096 |
| preliminary survey of edaphic algae in al-hasa region, saudi arabia. | five soil samples were taken from different cultivated sites from the north villages of al-hasa. three algal groups were recorded throughout this study, bacillariophyta, cyanophyta and chlorophyta. fifty-two genera of algae were identified in all the soils sampled during this investigation. out of these, 11 genera belonged to the chlorophyta; 16 genera belong to bacillariophyta and 25 genera to cyanophyta. penniate bacillariophyta (nitzschia, gyrosigma), oscillatorid cyanophyta (osillatoria, pho ... | 2007 | 19090128 |
| solid-phase/supercritical-fluid extraction for liquid chromatography of phenolic compounds in freshwater microalgae and selected cyanobacterial species. | in the present paper a new extraction technique based on the combination of solid-phase/supercritical-fluid extraction (spe/sfe) with subsequent reversed-phase hplc is described. the spe/sfe extractor was originally constructed from spe-cartridge incorporated into the sfe extraction cell. selected groups of benzoic acid derivatives (p-hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acid), hydroxybenzaldehydes (4-hydroxybenzaldehyde and 3,4-dihydroxybenzaldehyde) and cinnamic acid d ... | 2009 | 19111311 |
| structure of the biliverdin radical intermediate in phycocyanobilin:ferredoxin oxidoreductase identified by high-field epr and dft. | the cyanobacterial enzyme phycocyanobilin:ferredoxin oxidoreductase (pcya) catalyzes the two-step four-electron reduction of biliverdin ixalpha to phycocyanobilin, the precursor of biliprotein chromophores found in phycobilisomes. it is known that catalysis proceeds via paramagnetic radical intermediates, but the structure of these intermediates and the transfer pathways for the four protons involved are not known. in this study, high-field electron paramagnetic resonance (epr) spectroscopy of f ... | 2009 | 19159240 |
| structure-function, stability, and chemical modification of the cyanobacterial cytochrome b6f complex from nostoc sp. pcc 7120. | the crystal structure of the cyanobacterial cytochrome b(6)f complex has previously been solved to 3.0-a resolution using the thermophilic mastigocladus laminosus whose genome has not been sequenced. several unicellular cyanobacteria, whose genomes have been sequenced and are tractable for mutagenesis, do not yield b(6)f complex in an intact dimeric state with significant electron transport activity. the genome of nostoc sp. pcc 7120 has been sequenced and is closer phylogenetically to m. lamino ... | 2009 | 19189962 |
| structural basis of murein peptide specificity of a gamma-d-glutamyl-l-diamino acid endopeptidase. | the crystal structures of two homologous endopeptidases from cyanobacteria anabaena variabilis and nostoc punctiforme were determined at 1.05 and 1.60 a resolution, respectively, and contain a bacterial sh3-like domain (sh3b) and a ubiquitous cell-wall-associated nlpc/p60 (or chap) cysteine peptidase domain. the nlpc/p60 domain is a primitive, papain-like peptidase in the ca clan of cysteine peptidases with a cys126/his176/his188 catalytic triad and a conserved catalytic core. we deduced from st ... | 2009 | 19217401 |
| immunolocalization of the uptake hydrogenase in the marine cyanobacterium lyngbya majuscula ccap 1446/4 and two nostoc strains. | in n(2)-fixing cyanobacteria, the reduction of n(2) to nh(3) is coupled with the production of molecular hydrogen, which is rapidly consumed by an uptake hydrogenase, an enzyme that is present in almost all diazotrophic cyanobacteria. the cellular and subcellular localization of the cyanobacterial uptake hydrogenase remains uncertain, and it is definitely strain dependent. previous studies focused mainly on heterocystous cyanobacteria and used heterologous antisera. the present work represents t ... | 2009 | 19222582 |
| biosynthesis of a linoleic acid allylic epoxide: mechanistic comparison with its chemical synthesis and leukotriene a biosynthesis. | biosynthesis of the leukotriene a (lta) class of epoxide is a lipoxygenase-catalyzed transformation requiring a fatty acid hydroperoxide substrate containing at least three double bonds. here, we report on biosynthesis of a dienoic analog of lta epoxides via a different enzymatic mechanism. beginning with homolytic cleavage of the hydroperoxide moiety, a catalase/peroxidase-related hemoprotein from anabaena pcc 7120, which occurs in a fusion protein with a linoleic acid 9r-lipoxygenase, dehydrat ... | 2009 | 19244216 |
| nitrogen fixation in mixed hylocomium splendens moss communities. | the pleurocarpus feather moss, hylocomium splendens, is one of two co-dominant moss species in boreal forest ecosystems and one of the most common mosses on earth, yet little is known regarding its capacity to host cyanobacterial associates and thus contribute total ecosystem n. in these studies, we evaluated the n-fixation potential of the h. splendens-cyanobacteria association and contrasted the n-fixation activity with that of the putative n-fixing moss-cyanobacteria association of pleurozium ... | 2009 | 19252932 |
| directed biosynthesis of phytotoxic alkaloids in the cyanobacterium nostoc 78-12a. | nostocarboline, a chlorinated and n-methylated carbolinium alkaloid, displays potent and selective inhibition of photoautotrophic organisms as well as the malaria parasite plasmodium falciparum, while showing very low toxicity to bacterial and fungal pathogens, rat myoblasts and crustaceans. new derivatives of nostocarboline incorporating br, f or methyl substituents have been obtained through precursor-directed biosynthesis in nostoc 78-12a (identical to nostoc sp. atcc 43238) by feeding this c ... | 2009 | 19263450 |
| diversity and transcription of proteases involved in the maturation of hydrogenases in nostoc punctiforme atcc 29133 and nostoc sp. strain pcc 7120. | the last step in the maturation process of the large subunit of [nife]-hydrogenases is a proteolytic cleavage of the c-terminal by a hydrogenase specific protease. contrary to other accessory proteins these hydrogenase proteases are believed to be specific whereby one type of hydrogenases specific protease only cleaves one type of hydrogenase. in cyanobacteria this is achieved by the gene product of either hupw or hoxw, specific for the uptake or the bidirectional hydrogenase respectively. the f ... | 2009 | 19284580 |
| characterization of the hupsl promoter activity in nostoc punctiforme atcc 29133. | in cyanobacteria three enzymes are directly involved in the hydrogen metabolism; a nitrogenase that produces molecular hydrogen, h2, as a by-product of nitrogen fixation, an uptake hydrogenase that recaptures h2 and oxidize it, and a bidirectional hydrogenase that can both oxidize and produce h2.nostoc punctiforme atcc 29133 is a filamentous dinitrogen fixing cyanobacterium containing a nitrogenase and an uptake hydrogenase but no bidirectional hydrogenase. generally, little is known about the t ... | 2009 | 19284581 |
| removal of colour from textile effluent using cyanobacterial biomass. | the cyanobacterial species were isolated from fresh water pond of gura-vishnoiyan and were tested for their ability to decolourise the textile effluent. the reduction in colour of textile effluent with the use of dry biomass of cylindrospermum indicum, nostoc calcicola, calothrix weberi was comparatively observed after 2, 4 and 6 days, but maximum colour absorption was observed after 6 days. calothrix weberi was found the most effective species of cyanobacteria, which can remove the colour inten ... | 2008 | 19295090 |
| growth and periodicity of cyanobacterial bloom in a polluted pond of agra city. | periodical changes in physico-chemical properties and cyanophycean bloom in a pond ofagra city during the year 2005 and 2006 were studied. it was recorded that the pond water was polluted throughout the study period and this was closely associated with cyanobacterial bloom. during summer (march to june), the pond water was highly polluted, as it was rich in various nutrients and phosphates in particular. the ph of pond water was high with low do and this was associated with the highest peak of w ... | 2008 | 19297980 |
| the naturally split npu dnae intein exhibits an extraordinarily high rate in the protein trans-splicing reaction. | we have studied the naturally split alpha subunit of the dna polymerase iii (dnae) intein from nostoc punctiforme pcc73102 (npu) using purified proteins and determined an apparent first-order rate constant of (1.1+/-0.2)x10(-2) s(-1) at 37 degrees c. this represents the highest rate reported for the protein trans-splicing reaction so far (t(1/2) of approximately 60s). furthermore, the reaction was very robust and high-yielding with respect to different extein sequences, temperatures from 6 to 37 ... | 2009 | 19302791 |
| comparative toxicity of bentazon and molinate on growth, photosynthetic pigments, photosynthesis, and respiration of the portuguese ricefield cyanobacterium nostoc muscorum. | bentazon and molinate are selective herbicides recommended for integrated weed management in rice. their toxicity on growth and some biochemical and physiological parameters of nostoc muscorum, an abundant cyanobacterium in portuguese rice fields, was evaluated under laboratory conditions during time- and concentration-dependent exposure for 72 h. results showed that toxic concentrations (0.75-2 mm) of both herbicides have pleiotropic effects on the cyanobacterium. molinate was more toxic than b ... | 2010 | 19319991 |
| physiological characterization and electron microscopic investigation of cyanobacteria associated with wheat rhizosphere. | physiological attributes of a set of cyanobacterial strains, isolated from the rhizosphere of wheat (var. hd 2687), identified as belonging to the genera calothrix (n = 3), westiellopsis (1), hapalosiphon (2) and nostoc (2), were axenized and evaluated. the concentrated culture filtrates of three cyanobacterial strains - c. ghosei, h. intricatus and nostoc sp. were able to enhance germination percentage, radicle and coleoptile length in inhibition experiments with wheat seeds. indole-3-acetic ac ... | 2009 | 19330544 |
| molecular characterization and the effect of salinity on cyanobacterial diversity in the rice fields of eastern uttar pradesh, india. | salinity is known to affect almost half of the world's irrigated lands, especially rice fields. furthermore, cyanobacteria, one of the critical inhabitants of rice fields have been characterized at molecular level from many different geographical locations. this study, for the first time, has examined the molecular diversity of cyanobacteria inhabiting indian rice fields which experience various levels of salinity. | 2009 | 19344531 |
| solution structure of dnae intein from nostoc punctiforme: structural basis for the design of a new split intein suitable for site-specific chemical modification. | naturally split dnae intein from nostoc punctiforme (npu) has robust protein trans-splicing activity and high tolerance of sequence variations at the splicing junctions. we determined the solution structure of a single chain variant of npudnae intein by nmr spectroscopy. based on the nmr structure and the backbone dynamics of the single chain npudnae intein, we designed a functional split variant of the npudnae intein having a short c-terminal half (c-intein) composed of six residues. in vivo an ... | 2009 | 19344715 |
| current trends in high throughput proteomics in cyanobacteria. | advancements in genome sequencing and high throughput proteomics of cyanobacterial strains led to 13 published reports, from a small number of laboratories. these successful studies focused on synechocystis, nostoc and anabaena strains, prochlorococcus, and halotolerant euhalothece. the implications of emerging quantitative aspects developed and applied in these large-scale studies are assessed in the wake of advanced cyanobacterial research. furthermore, contributions from traditional and early ... | 2009 | 19345218 |
| endothelial cell-based methods for the detection of cyanobacterial anti-inflammatory and wound-healing promoting metabolites. | acute lung injury is accompanied by an increased endothelial chemokine production and adhesion molecule expression, which may result in an extensive neutrophil infiltration. moreover, a destruction of the alveolar epithelium and capillary endothelium may result in permeability edema. as such, the search for novel anti-inflammatory substances, able to downregulate these parameters as well as the tissue damage holds therapeutic promise. we therefore describe here the use of human endothelial cell- ... | 2007 | 19356051 |
| in vivo and in vitro protein ligation by naturally occurring and engineered split dnae inteins. | protein trans-splicing by naturally occurring split dnae inteins is used for protein ligation of foreign peptide fragments. in order to widen biotechnological applications of protein trans-splicing, it is highly desirable to have split inteins with shorter c-terminal fragments, which can be chemically synthesized. | 2009 | 19365564 |
| electron transfer protein complexes in the thylakoid membranes of heterocysts from the cyanobacterium nostoc punctiforme. | filamentous, heterocystous cyanobacteria are capable of nitrogen fixation and photoautotrophic growth. nitrogen fixation takes place in heterocysts that differentiate as a result of nitrogen starvation. heterocysts uphold a microoxic environment to avoid inactivation of nitrogenase, e.g. by downregulation of oxygenic photosynthesis. the atp and reductant requirement for the nitrogenase reaction is considered to depend on photosystem i, but little is known about the organization of energy convert ... | 2009 | 19366613 |
| hypocholesterolemic effect of nostoc commune var. sphaeroides kützing, an edible blue-green alga. | intake of an edible blue-green alga nostoc commune var. sphaeroides kützing (n. commune) has been shown to lower plasma total cholesterol concentration, but the mechanisms behind the hypocholesterolemic effect have not been elucidated. | 2009 | 19404563 |
| diversity of 23s rrna genes within individual prokaryotic genomes. | the concept of ribosomal constraints on rrna genes is deduced primarily based on the comparison of consensus rrna sequences between closely related species, but recent advances in whole-genome sequencing allow evaluation of this concept within organisms with multiple rrna operons. | 2009 | 19415112 |
| gene expression patterns associated with the biosynthesis of the sunscreen scytonemin in nostoc punctiforme atcc 29133 in response to uva radiation. | under exposure to uv radiation, some cyanobacteria synthesize sunscreen compounds. scytonemin is a heterocyclic indole-alkaloid sunscreen, the synthesis of which is induced upon exposure to uva (long-wavelength uv) radiation. we previously identified and characterized an 18-gene cluster associated with scytonemin biosynthesis in the cyanobacterium nostoc punctiforme atcc 29133; we now report on the expression response of these genes to a step-up shift in uva exposure. using quantitative pcr on c ... | 2009 | 19429608 |
| water-stress induced trehalose accumulation and control of trehalase in the cyanobacterium nostoc punctiforme iam m-15. | we investigated the biochemical properties of the enzymes involved in trehalose metabolism in the cyanobacterium nostoc punctiforme strain iam m-15 to elucidate the mechanism of trehalose accumulation in response to desiccation and salt stress. there was no detectable trehalose in fully hydrated n. punctiforme cells; however, these cells accumulated trehalose upon desiccation. moreover, nacl treatment also induced trehalose accumulation. the three genes for trehalose metabolism, trez (maltooligo ... | 2009 | 19436130 |
| microcystin production in the tripartite cyanolichen peltigera leucophlebia. | we show that the cyanobacterial symbionts of a tripartite cyanolichen can produce hepatotoxic microcystins in situ. microcystins were detected with high-performance liquid chromatography mass spectrometry both from cephalodia of the tripartite cyanolichen peltigera leucophlebia and from a symbiotic nostoc strain isolated from the same lichen specimen. genetic identities of symbiotic nostoc strains were studied by amplifying and sequencing the 16s rrna gene. also, the presence of the microcystin ... | 2009 | 19445594 |
| a versatile photoactivatable probe designed to label the diphosphate binding site of farnesyl diphosphate utilizing enzymes. | farnesyl diphosphate (fpp) is a substrate for a diverse number of enzymes found in nature. photoactive analogues of isoprenoid diphosphates containing either benzophenone, diazotrifluoropropionate or azide groups have been useful for studying both the enzymes that synthesize fpp as well as those that employ fpp as a substrate. here we describe the synthesis and properties of a new class of fpp analogues that links an unmodified farnesyl group to a diphosphate mimic containing a photoactive benzo ... | 2009 | 19447628 |
| alteration of the gastrointestinal microbiota of mice by edible blue-green algae. | to characterize the effect of edible blue-green algae (cyanobacteria) on the gastrointestinal microbiota of mice. | 2009 | 19486425 |