| on the linkages between chromophore and protein in biliproteins, vii. amino acid sequence in the chromophore regions of c-phycoerythrin from pseudanabaena w 1173 and phormidium persicinum. | bilipeptides from all chromophore regions were prepared by trypsin digestion of c-phycoerythrin from pseudanabaena w 1173 and phormidium persicinum. analytical separation and quantitative determination of bilipeptides was achieved by isoelectric focusing, preparative isolation by gel chromatography and ion-exchange chromatography. amino acid analysis revealed cysteine as the only amino acid common to all chromopeptides. amino acid sequences were determined by edman degradation and the dansyl-edm ... | 1978 | 417013 |
| gas vesicle synthesis in the cyanobacterium pseudanabaena sp.: occurrence of a single photoregulated gene. | gas vesicles are subcellular inclusions found in a large number of aquatic prokaryotes. the gvpa gene, which frequently occurs as a multigene family, encodes the major gas vesicle structural protein. in several cyanobacteria, another gene, gvpc, encodes a different protein which might be a dispensable element for gas vesicle formation. we report here the molecular characterization of a gvpa gene in pseudanabaena sp. pcc 6901. in this planktonic cyanobacterium, it is the only gvp gene which could ... | 1991 | 1904525 |
| structure and composition of freshwater microbial mats from a sulfur spring ("font pudosa", ne spain). | different types of microbial mats developing on the wall on a non-thermal sulfur freshwater spring have been studied. both, light and electron microscopy as well as hplc analysis of photosynthetic pigments revealed their structure and composition. prokaryotic chlorophylls and carotenoids helped in the taxonomical assignment of the main photosynthetic groups. "inverted position" mats (mat-i) were dominated by chromatiaceae; they were located closed to the water outlets (0.3 mm sulfide). "normal p ... | 1997 | 9106181 |
| nitrogen control of the glnn gene that codes for gs type iii, the only glutamine synthetase in the cyanobacterium pseudanabaena sp. pcc 6903. | pseudanabaena sp. strain pcc 6903 is the first cyanobacteria lacking the typical prokaryotic glutamine synthetase type i encoded by the glna gene. the glnn gene product, glutamine synthetase type iii, is the only glutamine synthetase activity present in this cyanobacterium. analysis of glnn expression clearly indicated a nitrogen-dependent regulation. pseudanabaena glnn gene expression and gsiii activity were upregulated under nitrogen starvation or using nitrate as a nitrogen source, while low ... | 1998 | 9988484 |
| phototrophs in high iron microbial mats: microstructure of mats in iron-depositing hot springs. | chocolate pots hot springs in yellowstone national park are high in ferrous iron, silica and bicarbonate. the springs are contributing to the active development of an iron formation. the microstructure of photosynthetic microbial mats in these springs was studied with conventional optical microscopy, confocal laser scanning microscopy and transmission electron microscopy. the dominant mats at the highest temperatures (48-54 degrees c) were composed of synechococcus and chloroflexus or pseudanaba ... | 2000 | 10858577 |
| [cyanobacteria as indicators of organic contamination]. | in two costa rican rivers used as receptors for domestic sewage, treated by primary stabilization ponds, were taken a total of 28 samplings located at the pond exit and at three different sites in each river: 100 m before the ponds discharge, at the discharge and 100 m after the discharge. these sampling were done for a five and a half years including dry and rainy seasons. in each sampling site, samples were collected of five different substrates: stones, submerge and semi submerge vegetation, ... | 1999 | 10883326 |
| cyanobacteria diversity and toxicity in a wastewater treatment plant (portugal). | cyanobacteria are common in eutrophic natural waters. being favoured by warm, stable and nutrient-enriched waters they may constitute an important part of the phytoplankton community in wastewater treatment plants (wwtp). the phytoplankton communities of two ponds (facultative and maturation) of the wwtp of esmoriz (north portugal) were studied, with particular importance given to cyanobacteria. mouse bioassays were performed with cyanobacteria samples during some of the blooms and elisa assays ... | 2001 | 11268858 |
| bioactive compounds from pseudanabaena species (cyanobacteria). | bioactive products of the multicellular filamentous benthic cyanobacterium, pseudanabaena species, isolated from wastewater stabilization ponds at marrakech, were tested against some pathogenic micro-organisms. extracellular and intracellular products released by this blue-green alga in the stationary, growth phase, reduced the survival of escherichia coli, salmonella sp., staphylococcus aureus and candida albicans, and stimulated the growth of non-o1 v. cholerae, whereas no significant effect w ... | 2001 | 11549237 |
| establishing a food-chain link between aquatic plant material and avian vacuolar myelinopathy in mallards (anas platyrhynchos). | avian vacuolar myelinopathy (avm) is a neurologic disease primarily affecting bald eagles (haliaeetus leucocephalus) and american coots (fulica americana). the disease was first characterized in bald eagles in arkansas in 1994 and then in american coots in 1996. to date, avm has been confirmed in six additional avian species. attempts to identify the etiology of avm have been unsuccessful to date. the objective of this study was to evaluate dermal and oral routes of exposure of birds to hydrilla ... | 2004 | 15465716 |
| limnothrix redekei (van goor) meffert (cyanobacteria) strains from lake kastoria, greece form a separate phylogenetic group. | three strains of limnothrix (cyanobacteria) isolated from lake kastoria, greece, were characterized based on their morphological features and 16s rrna gene sequences. the limnothrix isolates 007a, 165a, and 165c can morphologically be assigned to limnothrix redekei (van goor) meffert. the 16s rrna gene of the limnothrix strains showed a 99% similarity to the 16s rrna gene of planktothrix sp. fp1. limnothrix redekei strains 165a, 165c, 007a and planktothrix sp. fp1 formed a separate cluster in th ... | 2005 | 15688255 |
| cyanobacteria and prawn farming in northern new south wales, australia--a case study on cyanobacteria diversity and hepatotoxin bioaccumulation. | harmful cyanobacteria pose a hazard to aquatic ecosystems due to toxins (hepatotoxic microcystins, nodularins, and cylindrospermopsin) they produce. the microcystins and nodularins are potent toxins, which are also tumor promoters. the microcystins and nodularins may accumulate into aquatic organisms and be transferred to higher trophic levels, and eventually affect vector animals and consumers. prawn farming is a rapidly growing industry in australia. because information regarding effects of cy ... | 2005 | 15737678 |
| molecular characterization of cyanobacterial diversity in a shallow eutrophic lake. | we have studied the diversity of pelagic cyanobacteria in lake loosdrecht, the netherlands, through recovery and analysis of small subunit ribosomal rna gene sequences from lake samples and cyanobacterial isolates. we used an adapted protocol for specific amplification of cyanobacterial rdna for denaturing gradient gel electrophoresis (dgge) analysis. this protocol enabled direct comparison of cyanobacterial community profiles with overall bacterial profiles. the theoretical amplification specif ... | 2005 | 15683397 |
| detection of prochlorothrix in brackish waters by specific amplification of pcb genes. | prochlorothrix hollandica is the only filamentous chlorophyll b (chlb)-containing oxyphotobacterium that has been found in freshwater habitats to date. chlb serves as a light-harvesting pigment which is bound to special binding proteins (pcb). even though prochlorothrix was initially characterized as a highly salt-sensitive species, we detected it in a brackish water environment that is characterized by salinities of up to 12 practical salinity units. using pcr and reverse transcription, we ampl ... | 2003 | 14532086 |
| the gas vesicle gene (gvp) cluster of the cyanobacterium pseudanabaena sp. strain pcc 6901. | a gene cluster located downstream from gvpa in the cyanobacterium pseudanabaena sp. strain pcc 6901 has been cloned and sequenced. the three genes, orf1, gvpn and gvpj, are consecutive with no intergenic region. in contrast to gvpn and gvpj, which share high similarity at the amino acid level with their counterparts in other cyanobacteria and halophilic archaea, orf1 is only 29% identical to the c-terminal part of gvpc from anabaena flos-aquae and its sequence organization is reminiscent of the ... | 2001 | 11913779 |
| detection and quantification of microcystins from cyanobacteria strains isolated from reservoirs and ponds in morocco. | in morocco, the occurrence of toxic cyanobacteria blooms is confirmed in some water bodies used for recreational and/or as drinking water reservoirs. according to who recommendations, the establishment of a monitoring program for microcystins is a necessity. this paper presents toxicological studies of 19 toxic cyanobacteria strains of microcystis, synechocystis, pseudanabaena, and oscillatoria. these strains were isolated from various water bodies including natural lakes, reservoirs, and ponds ... | 2002 | 11847972 |
| the occurrence of cyanobacteria in pulp and paper waste-treatment systems. | pulp and paper secondary waste-treatment systems in brazil, canada, new zealand, and the u.s.a. contained dynamic cyanobacterial communities, some of which exceeded heterotrophic bacterial biomass. no other viable photoautotrophic populations were detected in the ponds. regardless of geographical location, oscillatoriales including phormidium, geitlerinema, and pseudanabaena were the dominant taxa. as well, chroococcus (chroococcales) was an important genus in brazil and new zealand. the possibl ... | 2001 | 11575503 |
| effects of pyridaphenthion on growth of five freshwater species of phytoplankton. a laboratory study. | the acute toxicity of the insecticide and acaricide pyridaphenthion to five species of freshwater phytoplankton, scenedesmus acutus, scenedesmus subspicatus, chlorella vulgaris, chlorella saccharophila and pseudanabaena galeata was determined. insecticide concentrations eliciting a 50% growth reduction over 96 h (ec50) ranged from 2.2 to 30.9 mg/l. the two species of chlorella and the cyanobacteria p. galeata were more tolerant than the two species of scenedesmus. concentrations of pyridaphenthi ... | 2001 | 11534908 |
| effects of the organophosphorus insecticide fenitrothion on growth in five freshwater species of phytoplankton. | the acute toxicity of the insecticide fenitrothion was measured using four freshwater algae (chlorella saccharophila, chlorella vulgaris, scenedesmus acutus, and scenedesmus subspicatus) and one cyanobacteria (pseudanabaena galeata). insecticide concentrations eliciting 50% growth reduction over 96 hr (ec50) ranged from 0.84 to 11.9 mg/l. fenitrothion was more toxic than other pesticides studied with the same algal species such as chlorsulfuron, molinate, and pyridaphenthion. the transformation ... | 2001 | 11501280 |
| adaptation of cyanobacteria to the sulfide-rich microenvironment of black band disease of coral. | black band disease (bbd) is a cyanobacteria-dominated microbial mat that migrates across living coral colonies lysing coral tissue and leaving behind exposed coral skeleton. the mat is sulfide-rich due to the presence of sulfate-reducing bacteria, integral members of the bbd microbial community, and the sulfide they produce is lethal to corals. the effect of sulfide, normally toxic to cyanobacteria, on the photosynthetic capabilities of five bbd cyanobacterial isolates of the genera geitlerinema ... | 2009 | 19049501 |
| isolation, characterization and quantification of microcystins (heptapeptides hepatotoxins) in microcystis aeruginosa dominated bloom of lalla takerkoust lake-reservoir (morocco). | this paper presents the first data on the identification, characterization and quantification of microcystins isolated from both an extract of a cyanobacteria natural bloom, collected from a eutrophic moroccan reservoir (lalla takerkoust, marrakesh) and an isolated strain cultivated under laboratory conditions. the isolation and purification of toxins was performed by reverse phase hplc and then characterized by amino acid analysis and fast atom bombardment mass spectrometry (fab-ms). chemical c ... | 2001 | 11384726 |
| origin and evolution of group i introns in cyanobacterial trna genes. | many trna(leu)uaa genes from plastids contain a group i intron. an intron is also inserted in the same gene at the same position in cyanobacteria, the bacterial progenitors of plastids, suggesting an ancient bacterial origin for this intron. a group i intron has also been found in the trna(fmet) gene of some cyanobacteria but not in plastids, suggesting a more recent origin for this intron. in this study, we investigate the phylogenetic distributions of the two introns among cyanobacteria, from ... | 1997 | 9352932 |
| strain characterization and classification of oxyphotobacteria in clone cultures on the basis of 16s rrna sequences from the variable regions v6, v7, and v8. | a major problem in development of a polyphasic taxonomy is that the identification of oxyphotobacterial strains (cyanobacteria and prochlorophytes) in culture collections may be incorrect. we have therefore developed a diagnostic system using the dna sequence polymorphism in the 16s rrna regions v6 to v8 for individual strain characterization and identification. pcr primers amplifying v6 to v8 from oxyphotobacteria in unialgal cultures were constructed. direct solid-phase or cyclic sequencing wa ... | 1997 | 9212409 |
| a role for cpeyz in cyanobacterial phycoerythrin biosynthesis. | pigment mutant strain fdr1 of the filamentous cyanobacterium fremyella diplosiphon is characterized by constitutive synthesis of the phycobiliprotein phycoerythrin due to insertional inactivation of the rcac regulatory gene by endogenous transposon tn5469. whereas the parental strain fd33 harbors five genomic copies of tn5469, cells of strain fdr1 harbor six genomic copies of the element; the sixth copy in fdr1 is localized to the rcac gene. electroporation of fdr1 cells yielded secondary pigmen ... | 1997 | 9023176 |
| amino acid transport in taxonomically diverse cyanobacteria and identification of two genes encoding elements of a neutral amino acid permease putatively involved in recapture of leaked hydrophobic amino acids. | the activities of uptake of thirteen 14c-labeled amino acids were determined in nine cyanobacteria, including the unicellular strains synechococcus sp. strain pcc 7942 and synechocystis sp. strain pcc 6803; the filamentous strain pseudanabaena sp. strain pcc 6903, and the filamentous, heterocyst-forming strains anabaena sp. strains pcc 7120 and pcc 7937; nostoc sp. strains pcc 7413 and pcc 7107; calothrix sp. strain pcc 7601 (which is a mutant unable to develop heterocysts); and fischerella musc ... | 1997 | 9006043 |
| an early origin of plastids within the cyanobacterial divergence is suggested by evolutionary trees based on complete 16s rrna sequences. | it is generally accepted that the plastids arose from a cyanobacterial ancestor, but the exact phylogenetic relationships between cyanobacteria and plastids are still controversial. most studies based on partial 16s rrna sequences suggested a relatively late origin of plastids within the cyanobacterial divergence. in order to clarify the exact relationship and divergence order of cyanobacteria and plastids, we studied their phylogeny on the basis of nearly complete 16s rrna gene sequences. the d ... | 1995 | 8524048 |
| general distribution of the nitrogen control gene ntca in cyanobacteria. | the ntca gene from synechococcus sp. strain pcc 7942 encodes a regulatory protein which is required for the expression of all of the genes known to be subject to repression by ammonium in that cyanobacterium. homologs to ntca have now been cloned by hybridization from the cyanobacteria synechocystis sp. strain pcc 6803 and anabaena sp. strain pcc 7120. sequence analysis has shown that these ntca genes would encode polypeptides strongly similar (77 to 79% identity) to the synechococcus ntca prote ... | 1993 | 8366058 |
| seasonal succession and diversity of phytoplankton in a eutrophic lagoon (liman lake). | the seasonal succession, composition and diversity of phytoplankton in a eutrophic lagoon (liman lake) were studied between january 2002 and november 2003. samples were collected from surface water and deeper (1 m depth) at stations and species diversity (shannon-weaver, h) and evenness were calculated. shannon diversty was similar at station 1 and station 2. minimum and maximum diversity values (0.101 and 0.765 bits. mm3) were recorded in june and july 2003 at station 2. cluster analysis and nm ... | 2010 | 21387913 |
| sequence and structure of the rna subunit of rnase p from the cyanobacterium pseudoanabaena sp. pcc6903. | the catalytic rna subunit of ribonuclease p (rnase p) from the cyanobacterium pseudoanabaena sp. pcc6903 has been cloned and sequenced. the rna has a primary and secondary structure with overall similarity to other cyanobacterial rnase p rnas characterized so far but contains some peculiarities of its own. a consensus promoter sequence can be identified at the 5' end of the gene. | 1994 | 7519449 |
| effects of chromatic illumination on cyanobacterial phycobilisomes. evidence for the specific induction of a second pair of phycocyanin subunits in pseudanabaena 7409 grown in red light. | pseudanabaena 7409 is a chromatically cyanobacterium which photocontrols the synthesis of both phycoerythrin and phycocyanin [tandeau de marsac (1977) j. bacteriol. 130, 82--91]. phycobilisomes, isolated from cells grown in either green or red light, have been dissociated and the component biliproteins purified and characterized. phycobilisomes isolated from cells grown in green light were composed of allophycocyanin b, allophycocyanin, two phycocyanin subunits (one alpha-type and one beta-type ... | 1981 | 6796413 |
| phycoerythrins of marine unicellular cyanobacteria. iii. sequence of a class ii phycoerythrin. | the genes for the alpha and beta subunits of a novel six bilin-bearing (class ii) phycoerythrin were cloned from synechococcus sp. wh8020 and sequenced. the cloned genes (mpea and mpeb) were detected by homology with the genes for c-phycoerythrin from pseudanabaena sp. pcc7409. the mpe locus occurs once in the genome and is arranged similarly to that of many other phycobiliproteins, with mpea shortly 3' of mpeb. sequence comparison suggests that this phycoerythrin (and perhaps all class ii phyco ... | 1991 | 1903390 |
| molecular cloning and transcriptional analysis of the cpeba operon of the cyanobacterium pseudanabaena species pcc7409. | the cpeba operon of the group iii chromatically adapting cyanobacterium pseudanabaena species pcc 7409 was cloned, sequenced and characterized. the cpeba genes are transcribed in green-light-grown cells as an abundant 1400-nucleotide mrna which initiates 69 nucleotides upstream from the cpeb translation start. extensive sequence identity, extending 70 nucleotides 5' to the transcription start, occurs among cpeba promoters of group ii and iii chromatic adapters. cell extracts of green-light-grown ... | 1991 | 1809846 |
| Effects of nitrate reduction on the eutrophication of an urban man-made lake (Palácio de Cristal, Porto, Portugal). | The monitoring of phytoplankton is an important component of water quality assessment in artificial and natural lakes. The evolution of eutrophication in an urban man-made lake (Palácio de Cristal, Porto, Portugal) was followed after remediation measures were applied. Nutrients as well as the phytoplankton community were monitored and the results compared with those of a previous study. Sampling was done in four sites of the lake so as to assess the efficiency of NO3 removal by the phytoplankton ... | 2011 | 21882554 |
| conjugative gene transfer in marine cyanobacteria: synechococcus sp., synechocystis sp. and pseudanabaena sp. | versatility of gene transfer by transconjugation in marine cyanobacteria was demonstrated. in this study, seven different marine cyanobacteria were used as recipient cells. first, transconjugation was carried out using the mobilizable transposon (tn5) carrying plasmid psup1021. transconjugates were observed in all marine cyanobacteria tested. second, the broad-host-range vector pkt0230 (incq) was tested for transconjugation. pkt230 has been successfully transferred in a marine cyanobacterium syn ... | 1992 | 1368911 |
| a long-term copper exposure on freshwater ecosystem using lotic mesocosms: primary producer community responses. | copper is commonly used as an algicide and plant herbicide in the aquatic environment. despite of its frequent application in rivers, ponds and lakes, few studies have been performed at the ecosystem level on primary producers' communities. a long-term lotic mesocosms study was carried on, in 20m long channels, under environmentally realistic concentrations of copper (0, 5, 25 and 75 microgl(-1)) delivered continuously for 18 months. results showed significant effects at the 25 and 75 microgl(-1 ... | 2007 | 17239970 |
| determination of cyanobacterial diversity during algal blooms in daechung reservoir, korea, on the basis of cpcba intergenic spacer region analysis. | the detection and prevention of cyanobacterial blooms are important issues in water quality management. as such, the diversity and community dynamics of cyanobacteria during cyanobacterial bloom in the daechung reservoir, korea, were studied by analyzing the intergenic spacer (igs) region between phycocyanin subunit genes cpcb and cpca (cpcba igs). to amplify the cpcba igs from environmental samples, new pcr primers that could cover a wider range of cyanobacteria than previously known primers we ... | 2006 | 16672464 |
| contiguous organization of nitrogenase genes in a heterocystous cyanobacterium. | the organization of the three structural nitrogen fixation (nif) genes that encode nitrogenase (nif k and nif d) and nitrogenase reductase (nif h) have been examined in a number of cyanobacteria. hybridization of anabaena 7120 nif gene probes to restriction endonuclease-digested genomic dna has shown (a) that cyanobacteria incapable of n(2) fixation have no regions of dna with significant homology to the three nif probes, (b) that pseudanabaena sp., a nonheterocystous cyanobacterium, has a conti ... | 1987 | 16665666 |
| the effects of nitrogen deficiency on pigments and lipids of cyanobacteria. | in contrast to what happens in higher plants and eukaryotic algae, a nitrogen deficiency during growth causes a change in pigment composition but no significant changes in whole cell lipid and fatty acid composition of the two cyanobacteria, pseudanabaena sp. (strain m2) and oscillatoria splendida (strain l3). nitrogen deficiency does not affect the cellular content in chlorophyll a, but it causes a selective loss in phycobiliproteins; carotenoid content increases with phycocyanin depletion. the ... | 1987 | 16665349 |
| a comparative study of the thermal stability of plastocyanin, cytochrome c(6) and photosystem i in thermophilic and mesophilic cyanobacteria. | cytochrome c(6) (cyt) from the thermophilic cyanobacterium phormidium laminosum has been purified and characterized. it is a mildly acidic protein, with physicochemical properties very similar to those of plastocyanin (pc). this is in agreement with the functional interchangeability of the two metalloproteins as electron donors to photosystem i (ps i). the kinetic analyses of the interaction of pc and cyt with photosystem i show that both metalloproteins reduce ps i with similar efficiencies, ac ... | 2001 | 16252173 |
| isolation and identification of antifungal and antialgal alkaloids from haplophyllum sieversii. | bioassay-guided fractionation of the hexane/ethyl acetate/water (h/etoac/h2o) crude extract of the aerial parts of haplophyllum sieversii was performed because of preliminary screening data that indicated the presence of growth inhibitory components against colletotrichum fragariae, colletotrichum gloeosporioides, and colletotrichum acutatum. fractionation was directed using bioautographical methods resulting in the isolation of the bioactive alkaloids flindersine, anhydroevoxine, haplamine, and ... | 2005 | 16190626 |
| comparative biochemical and functional studies of family i soluble inorganic pyrophosphatases from photosynthetic bacteria. | soluble inorganic pyrophosphatases (inorganic diphosphatases, ec 3.6.1.1) were isolated and characterized from three phylogenetically diverse cyanobacteria--synechocystis sp. pcc 6803, anabaena sp. pcc 7120, and pseudanabaena sp. pcc 6903--and one anoxygenic photosynthetic bacterium, rhodopseudomonas viridis (purple nonsulfur). these enzymes were found to be family i soluble inorganic pyrophosphatases with c. 20 kda subunits with diverse oligomeric structures. the corresponding ppa genes were cl ... | 2007 | 17635582 |
| plankton community as an indicator of water quality in tropical shrimp culture ponds. | the plankton was examined as an indicator of water quality in 14 shrimp litopenaeus vannamei farms in brazil in 2003. the ponds were categorized by high stocking density (>30 pl m(-2)) of phytoplankton, consisting of 51 species with concentrations ranging from 365,218+/-416,615 cells ml(-1) to 1,961,675+/-3,160,172 cells ml(-1). diatoms contributed to almost 70% of the species number and high densities resulted from cyanophyta blooms, mainly pseudanabaena cf limnetica. forty zooplankton taxa wer ... | 2008 | 18538353 |
| [phytoplankton from tehuantepec river, oaxaca, mexico and some biogeographical relationships]. | phytoplankton species collected from the limnetic to euryhaline sections of tehuantepec river were identified, classified and compared with regional information from mexico and south america. we collected 15 samples every three months from july 1997 through august 1998 with a 20 microm net and a van dorn bottle. indicator values and a code checklist are included. a total of 58 families, 121 genera, 273 species, one subspecies, 75 varieties, 13 forms and one morphotype were identified in the taxa ... | 2008 | 18624226 |
| [identification of two cyanobacterial strains isolated from the kotel'nikovskii hot spring of the baikal rift]. | two cyanobacterial strains, pseudanabaena sp. 0411 and synechococcus sp. 0431, were isolated from a sample collected in the kotel'nikovskii hot spring of the baikal rift. according to the results of light and transmission electron microscopy, as well as of the phylogenetic analysis of the 16s rrna gene, these cyanobacteria were classified as pseudanabaena sp. nov. and synechococcus bigranulatus skuja. the constructed phylogenetic tree shows that the studied strains are positioned in the clades o ... | 2008 | 18683660 |
| phenotypic and genetic diversification of pseudanabaena spp. (cyanobacteria). | pseudanabaena species are poorly known filamentous bloom-forming cyanobacteria closely related to limnothrix. we isolated 28 pseudanabaena strains from the baltic sea (bs) and the albufera de valencia (av; spain). by combining phenotypic and genotypic approaches, the phylogeny, diversity and evolutionary diversification of these isolates were explored. analysis of the in vivo absorption spectra of the pseudanabaena strains revealed two coexisting pigmentation phenotypes: (i) phycocyanin-rich (pc ... | 2009 | 18769459 |
| the timescale of phenotypic plasticity and its impact on competition in fluctuating environments. | although phenotypic plasticity can be advantageous in fluctuating environments, it may come too late if the environment changes fast. complementary chromatic adaptation is a colorful form of phenotypic plasticity, where cyanobacteria tune their pigmentation to the prevailing light spectrum. here, we study the timescale of chromatic adaptation and its impact on competition among phytoplankton species exposed to fluctuating light colors. we parameterized a resource competition model using monocult ... | 2008 | 18828745 |
| [cyanobacteria and their toxic potential in dam water content in northern tunisia]. | in order to get data about toxic cyanobacteria and their potential sanitary risk in 12 waterbodies situated in the north of tunisia, some taxonomic, ecological and toxicological studies were undertaken since 2001. this paper provides the first screening of the potential toxic species of cyanobacteria as well as their geographical distribution. the microscopic examination of the phytoplankton samples show 42 species of cyanobacteria; 9 are frequently quoted by the literature as being potentially ... | 2006 | 19388600 |
| cyanotoxins from black band disease of corals and from other coral reef environments. | many cyanobacteria produce cyanotoxins, which has been well documented from freshwater environments but not investigated to the same extent in marine environments. cyanobacteria are an obligate component of the polymicrobial disease of corals known as black band disease (bbd). cyanotoxins were previously shown to be present in field samples of bbd and in a limited number of bbd cyanobacterial cultures. these toxins were suggested as one of the mechanisms contributing to bbd-associated coral tiss ... | 2009 | 19554362 |
| undirected motility of filamentous cyanobacteria produces reticulate mats. | the roles of biology in the morphogenesis of microbial mats and stromatolites remain enigmatic due to the vast array of physical and chemical influences on morphology. however, certain microbial behaviors produce complex morphological features that can be directly attributed to motility patterns. specifically, laboratory experiments with a strain of the cyanobacteria pseudanabaena demonstrate that distinctive morphologies arise from the undirected gliding and colliding of filaments. when filamen ... | 2010 | 20345889 |
| the apoptosis-inducing activity towards leukemia and lymphoma cells in a cyanobacterial culture collection is not associated with mouse bioassay toxicity. | cyanobacteria (83 strains and seven natural populations) were screened for content of apoptosis (cell death)-inducing activity towards neoplastic cells of the immune (jurkat acute t-cell lymphoma) and hematopoetic (acute myelogenic leukemia) lineage. apoptogenic activity was frequent, even in strains cultured for decades, and was unrelated to whether the cyanobacteria had been collected from polar, temperate, or tropic environments. the activity was more abundant in the genera anabaena and micro ... | 2011 | 20689978 |
| effect of preservatives for food grade c-phycoerythrin, isolated from marine cyanobacteria pseudanabaena sp. | c-phycoerythrin is water soluble red color chromo-protein, which is used as a natural food colorant. the effect of selected edible preservatives like citric acid, sodium chloride, sucrose and calcium chloride on the stability of c-phycoerythrin at 0±5°c and 35±5°c was studied in aqueous solution. experiment was carried out to select a stabilizing agent having hofmeister series behavior acting on hydrophobic interactions. the denaturation of phycoerythrin with urea as denaturant and effect of dif ... | 2010 | 20709098 |
| isolation and molecular characterization of a multicellular cyanobacterium, limnothrix/pseudanabaena sp. strain abrg5-3. | a cyanobacterium, semi-filamentous multicellular strain abrg5-3, was isolated and its unique nature was characterized. this axenic strain formed colonies and was motile on an agarose plate. the 16s rrna gene of abrg5-3 exhibited similarities to those of the limnothrix and pseudanabaena strains, which are known as filamentous and nonheterocystous cyanobacteria. peaks in absorbance for the accumulation of chlorophyll a, phycocyanin, and phycoerythrin were observed in the cell extract. natural sepa ... | 2010 | 20834156 |
| biosynthesis of 2-methylisoborneol in cyanobacteria. | the production of odiferous metabolites, such as 2-methlyisoborneol (mib), is a major concern for water utilities worldwide. although mib has no known biological function, the presence of the earthy/musty taste and odor attributed to this compound result in the reporting of numerous complaints by consumers, which undermines water utility performance and the safe and adequate provision of potable waters. cyanobacteria are the major producers of mib in natural waters, by mechanisms that have heret ... | 2010 | 21174459 |
| genes associated with 2-methylisoborneol biosynthesis in cyanobacteria: isolation, characterization, and expression in response to light. | the volatile microbial metabolite 2-methylisoborneol (2-mib) is a root cause of taste and odor issues in freshwater. although current evidence suggests that 2-mib is not toxic, this compound degrades water quality and presents problems for water treatment. to address these issues, cyanobacteria and actinomycetes, the major producers of 2-mib, have been investigated extensively. in this study, two 2-mib producing strains, coded as pseudanabaena sp. and planktothricoids raciborskii, were used in o ... | 2011 | 21490938 |
| vertical and temporal dynamics of cyanobacteria in the carpina potable water reservoir in northeastern brazil. | this study analysed vertical and temporal variations of cyanobacteria in a potable water supply in northeastern brazil. samples were collected from four reservoir depths in the four months; september and december 2007; and march and june 2008. the water samples for the determination of nutrients and cyanobacteria were collected using a horizontal van dorn bottle. the samples were preserved in 4% formaldehyde for taxonomic analysis using an optical microscope, and water aliquots were preserved in ... | 2011 | 21755163 |
| detection and identification of potentially toxic cyanobacteria in polish water bodies. | the main goal of this study was to determine the distribution of potentially toxic cyanobacteria in 39 selected polish water bodies. from the water bodies with blooms and also from those in which blooms were not visible 87 samples were investigated. for the first time samples from ponds localized in villages with high agricultural activities were included. lakes for which microcystin concentrations had been determined before were included as a reference for the research. the detection of cyanoba ... | 2011 | 21750783 |
| preparation of highly purified c-phycoerythrin from marine cyanobacterium pseudanabaena sp. | c-phycoerythrin was isolated and purified from marine pseudanabaena sp. using two step chromatographic methods. phycobiliproteins in the marine pseudanabaena was extracted in 100mm phosphate buffer (ph 7.2) and precipitated by salting out. the precipitated c-phycoerythrin was purified by gel filtration with sephadex g-150, and then it was purified by ion exchange chromatography on deae cellulose, which was developed by linear ionic strength gradients. purified phycoerythrin showed absorption max ... | 2011 | 21745573 |
| effect of light quality on the c-phycoerythrin production in marine cyanobacteria pseudanabaena sp. isolated from gujarat coast, india. | the isolated cyanobacterium containing biopigments like chlorophyll-a, phycoerythrin, phycocyanin, and carotenoid was cultured under different quality of light modes to ascertain biomass and pigment productivity. on the basis of 16s rrna gene sequence, the isolate was identified as pseudanabaena sp. maximum biomass concentration obtained in white-, blue-, and green-light was 0.82, 0.94, and 0.89 g/l, respectively. it was observed that maximum phycoerythrin production was in green light (39.2 mg/ ... | 2012 | 21906679 |