| identification of an atp-binding cassette transporter involved in bicarbonate uptake in the cyanobacterium synechococcus sp. strain pcc 7942. | exposure of cells of cyanobacteria (blue-green algae) grown under high-co(2) conditions to inorganic c-limitation induces transcription of particular genes and expression of high-affinity co(2) and hco(3)(-) transport systems. among the low-co(2)-inducible transcription units of synechococcus sp. strain pcc 7942 is the cmpabcd operon, encoding an atp-binding cassette transporter similar to the nitrate/nitrite transporter of the same cyanobacterium. a nitrogen-regulated promoter was used to selec ... | 1999 | 10557362 |
| separation and identification of hydrocarbons and other volatile compounds from cultured blue-green alga nostoc sp. by gas chromatography-mass spectrometry using serially coupled capillary columns with consecutive nonpolar and semipolar stationary phases. | the complex hydrocarbons and volatile compounds produced by cultured blue-green alga nostoc sp. were separated by serially coupled capillary columns with consecutive nonpolar and semipolar stationary phases. more than 130 metabolites including, cyclohexane, cyclopentane, normal saturated hydrocarbons (c7-c30), fatty acids and benzene derivatives were identified by gc-ms. the most abundant family of hydrocarbons identified were derivatives of cyclohexane (41) and cyclopentane (11). most of these ... | 1999 | 10596980 |
| cyanobacterial toxins: removal during drinking water treatment, and human risk assessment. | cyanobacteria (blue-green algae) produce toxins that may present a hazard for drinking water safety. these toxins (microcystins, nodularins, saxitoxins, anatoxin-a, anatoxin-a(s), cylindrospermopsin) are structurally diverse and their effects range from liver damage, including liver cancer, to neurotoxicity. the occurrence of cyanobacteria and their toxins in water bodies used for the production of drinking water poses a technical challenge for water utility managers. with respect to their remov ... | 2000 | 10698727 |
| anti-hiv activity of extracts and compounds from algae and cyanobacteria. | the human immunodeficiency virus (hiv) is the retrovirus that causes the acquired immune deficiency disease syndrome (aids). this review discusses the anti-hiv activity of extracts and compounds isolated from freshwater and marine algae, and cyanobacteria (formerly called "blue-green algae"). compounds and extracts with anti-hiv activity are also active against other retroviruses such as herpes simplex virus (hsv), but the amount of antiviral activity varies with the compound and the virus. most ... | 2000 | 10702339 |
| isolation and characterization of a mannan-binding lectin from the freshwater cyanobacterium (blue-green algae) microcystis viridis. | microcystis viridis nies-102 strain, a unicellular freshwater bloom-forming cyanobacterium, showed transient hemagglutinating activity in laboratory culture during stationary phase under nonaeration conditions. however, the hemagglutinating activity which was inhibited with yeast mannan could not be observed during culture with aeration. a mannan-binding lectin named mvl was isolated with the assay of the hemagglutinating activity against rabbit erythrocytes from the cyanobacterium by successive ... | 1999 | 10600484 |
| desert bighorn sheep mortality due to presumptive type c botulism in california. | during a routine telemetry flight of the mojave desert (california, usa) in august 1995, mortality signals were detected from two of 12 radio-collared female desert bighorn sheep (ovis canadensis) in the vicinity of old dad peak in san bernardino county (california). a series of field investigations determined that at least 45 bighorn sheep had died near two artificial water catchments (guzzlers), including 13 bighorn sheep which had presumably drowned in a guzzler tank. samples from water conta ... | 2000 | 10682765 |
| assessing potential health risks from microcystin toxins in blue-green algae dietary supplements. | the presence of blue-green algae (bga) toxins in surface waters used for drinking water sources and recreation is receiving increasing attention around the world as a public health concern. however, potential risks from exposure to these toxins in contaminated health food products that contain bga have been largely ignored. bga products are commonly consumed in the united states, canada, and europe for their putative beneficial effects, including increased energy and elevated mood. many of these ... | 2000 | 10811570 |
| catalase-peroxidases in cyanobacteria--similarities and differences to ascorbate peroxidases. | cyanobacteria (blue-green algae) are oxygenic phototrophic bacteria carrying out plant-type photosynthesis. the only hydrogen peroxide scavenging enzymes in at least two unicellular species have been demonstrated to be bifunctional cytosolic catalase-peroxidases (catpxs) having considerable homology at the active site with plant ascorbate peroxidases (apxs). in this paper we examined optical and kinetic properties of catpxs from the cyanobacteria anacystis nidulans and synechocystis pcc 6803 and ... | 1999 | 10694066 |
| microcystin-lr toxicodynamics, induced pathology, and immunohistochemical localization in livers of blue-green algae exposed rainbow trout (oncorhynchus mykiss). | with this retrospective study, we investigated the temporal pattern of toxin exposure and pathology, as well as the topical relationship between hepatotoxic injury and localization of microcystin-lr, a potent hepatotoxin, tumor promoter, and inhibitor of protein phosphatases-1 and -2a (pp), in livers of mc-gavaged rainbow trout (oncorhynchus mykiss) yearlings, using an immunohistochemical detection method and mc-specific antibodies. h&e stains of liver sections were used to determine pathologica ... | 2000 | 10774818 |
| structural organization of microcystin biosynthesis in microcystis aeruginosa pcc7806: an integrated peptide-polyketide synthetase system. | blooms of toxic cyanobacteria (blue-green algae) have become increasingly common in the surface waters of the world. of the known toxins produced by cyanobacteria, the microcystins are the most significant threat to human and animal health. these cyclic peptides are potent inhibitors of eukaryotic protein phosphatases type 1 and 2a. synthesized nonribosomally, the microcystins contain a number of unusual amino acid residues including the beta-amino polyketide moiety adda (3-amino-9-methoxy-2,6, ... | 2000 | 11033079 |
| using an enzyme linked immunosorbent assay (elisa) and a protein phosphatase inhibition assay (ppia) for the detection of microcystins and nodularins. | cyanotoxins produced by cyanobacteria (blue-green algae) include potent neurotoxins and hepatotoxins. the hepatotoxins include cyclic peptide microcystins and nodularins plus the alkaloid cylindrospermopsins. among the cyanotoxins the microcystins have proven to be the most widespread, and are most often implicated in animal and human poisonings. this paper presents a practical guide to two widely used methods for detecting and quantifying microcystins and nodularins in environmental samples-the ... | 1999 | 11122533 |
| use of recombinant aequorin to study calcium homeostasis and monitor calcium transients in response to heat and cold shock in cyanobacteria. | we investigated the possibility of ca(2+) signaling in cyanobacteria (blue-green algae) by measuring intracellular free ca(2+) levels ([ca(2+)](i)) in a recombinant strain of the nitrogen fixing cyanobacterium anabaena strain sp. pcc7120, which constitutively expresses the ca(2+)-binding photoprotein apoaequorin. the homeostasis of intracellular ca(2+) in response to increasing external ca(2+) has been studied in this strain. the resting level of free ca(2+) in anabaena was found to be between 1 ... | 2000 | 10806234 |
| complex dynamics of adaptation in a nonaxenic microcystis culture. 2. computer simulation of dinotrophenol effects. | a hypothesis was modeled to account for complex 20-day dynamics in a culture of blue-green algae microcystis and heterotrophic bacteria exposed to 2,4-dinitrophenol (dnp). in trials with little or no added dnp, a limiting factor (light or co(2)) may cause algal density to fluctuate after 14 days of increase. such factors may be unimportant at levels of dnp that restrict photosynthesis. bacterial growth may be limited by organic substrate, and bacteria may be more resistant to dnp than blue-green ... | 2001 | 11222033 |
| effects of organic and inorganic fertilisers on mosquito populations in rice fields of southern india. | the effects of nitrogenous (inorganic) fertilisers, organic manures and blue-green algae (bga) biofertiliser on mosquito populations (diptera: culicidae) were studied in rice fields of madurai, tamil nadu, south india, with particular attention to culex vishnui theobald, cx. pseudovishnui colless and cx. tritaeniorhynchus giles, the vectors of japanese encephalitis (je). the application of urea, a nitrogenous fertiliser, in rice fields significantly increased the grain yield and the population d ... | 2000 | 11129699 |
| [the postradiation use of vitamin-containing complexes and a phycocyanin extract in a radiation lesion in rats]. | wistar rats have been exposed to x-rays with a dose of 5 gy. significant decrease in dehydrogenase activity, energy-rich phosphate level and efficiency of antioxidant defence and significant increase in pyruvate amount were observed within 4 weeks. it was also found that the feeding of exposed rats with phycocyanin extract from blue-green algae spirulina platensis lead to correcting effect. the same result was observed after injections of tocopherol or complex of six water-soluble vitamins. the ... | 2000 | 10907410 |
| the application of powdered activated carbon for mib and geosmin removal: predicting pac doses in four raw waters. | blooms of blue-green algae in reservoirs often produce the musty-earthy taste and odour algal metabolites 2-methylisoborneol (mib) and geosmin. mib and geosmin are not removed by conventional water treatment and their presence in the distribution system, even at low ng l-1 levels, can result in consumer complaints. powdered activated carbon (pac) can effectively remove mib and geosmin when the correct dose is applied. the homogeneous surface diffusion model (hsdm) was used to predict pac doses r ... | 2001 | 11268853 |
| the use of bioluminescent biotests for study of natural and laboratory aquatic ecosystems. | a set of bioluminescent tests was developed to monitor water quality in natural and laboratory ecosystems. it consisted of four bioluminescent systems: luminous bacteria, coupled enzyme system nadh:fmn-oxidoreductase-luciferase and triplet enzyme systems with alcohol dehydrogenase and trypsin. the set of biotests was applied for a small forest pond (siberia, russia), laboratory microecosystems polluted with benzoquinone and a batch culture of blue-green algae. thereby effects of natural water co ... | 2001 | 11272913 |
| algal growth inhibition effects and inducement modes by plant-producing phenols. | evaluated here are the inhibitory effects on blue-green algae (microcystis aeruginosa) produced by nine plant-producing phenols (caffeic, p-coumaric, ferulic, protocatechuic, sinapic, syringic, and vanillic acids, catechol, and hydroquinone), two plant-produced acids (quinic and shikimic acid), phenol, resorcinol, hydroxy hydroquinone, and phloroglucinol. algal assays confirmed growth inhibition of m. aeruginosa by polyphenols, i.e., caffeic/protocatechuic acid, catechol, hydroquinone, hydroxy h ... | 2001 | 11329689 |
| ultrasonic irradiation for blue-green algae bloom control. | a novel application of ultrasonic irradiation for rapid control of blue-green algae (bga) bloom was investigated. potassium iodide (ki) experiments demonstrated that frequency and input power are the major factors that affect the ultrasonic irradiation intensity. short exposure (3 s) to ultrasonic irradiation (120 w input power, 28 khz) effectively settled naturally growing bga suspension. electron microscopy reconfirmed that sedimentation was caused by the disruption and collapse of gas vacuole ... | 2001 | 11329801 |
| vegetative survival, akinete formation and germination in three blue-green algae and one green alga in relation to light intensity, temperature, heat shock and uv exposure. | the mere vegetative survival was not sufficient but suitable growth conditions were required for akinete formation to occur in the blue-green algae anabaena iyengarii, westiellopsis prolifica, nostochopsis lobatus and in the green alga pithophora oedogonia. in all algae, akinetes were neither formed nor germinated in darkness, and while dim light of 300 lx was sufficient for most of akinetes to germinate and also to maintain vegetative survival, it was not adequate for optimum akinete formation. ... | 2000 | 11347271 |
| production and specificity of mono and polyclonal antibodies against microcystins conjugated through n-methyldehydroalanine. | microcystins (mcs) are a group of closely related toxic cyclic heptapeptides produced by common cyanobacteria (blue-green algae). their toxicity is associated with specific inhibition of intracellular protein phosphatases type-1 and type-2a (pp1 and pp2a, respectively). we have developed a battery of antibodies to microcystins using chemical modification (aminoethylation) of one of its core amino acids, n-methyl-dehydroalanine. the developed antibodies displayed different reactivities to closely ... | 2001 | 11024487 |
| gelation of edible blue-green algae protein isolate (spirulina platensis strain pacifica): thermal transitions, rheological properties, and molecular forces involved. | proteins isolated from blue-green algae spirulina platensis strain pacifica were characterized by visible absorption, differential scanning calorimetry (dsc), viscometry, and dynamic oscillatory rheological measurements. unique thermal unfolding, denaturation, aggregation, and gelation of the algal protein isolate are presented. dsc analysis showed that thermal transitions occur at about 67 and 109 degrees c at neutral ph. calcium chloride stabilized the quaternary structure against denaturation ... | 2001 | 11262046 |
| ozonation of nom and algal toxins in four treated waters. | the occurrence of cyanobacteria (blue-green algae) blooms and the possibility of production of cyanotoxins (algal toxins) have become major concerns for drinking water providers worldwide. ozone has been shown to be effective for the destruction of some classes of toxins under specific conditions, although most researchers agree that the dose and contact time required will depend on water quality. the clarification of the relative effects of water quality parameters such as dissolved organic car ... | 2001 | 11257877 |
| antioxidant activity of different fractions of spirulina platensis protean extract. | spirulina platensis, planktonic blue-green algae, is gaining increasing attention because of its nutritional and medicinal properties. this microalgae contains phycobiliproteins (phycocyanin and allophycocyanin). previous reports from our laboratory have shown that a protean extract of s. platensis is a potent free-radical scavenger (hydroxyl and peroxyl radicals) and inhibits microsomal lipid peroxidation. the aim of this study was to purify and characterize phycocyanin of s. platensis. besides ... | 2001 | 11482785 |
| metal levels in feathers of cormorants, flamingos and gulls from the coast of namibia in southern africa. | arsenic, cadmium, chromium, lead, manganese, mercury, selemium, and tin concentrations were measured in the feathers of cape cormorant (phalacrocorax capensis), hartlaub's gull (larus hartlaubii), kelp gull (larus dominicanus), and lesser flamingo (phoeniconaias minor) from the coast of namibia in southern africa. metal concentrations in feathers represent the concentrations in the blood supply at the time of feather formation. cape cormorants are piscivores; kelp gulls are primarily piscivores; ... | 2001 | 11465667 |
| crystal structure of a light-harvesting protein c-phycocyanin from spirulina platensis. | the crystal structure of c-phycocyanin, a light-harvesting phycobiliprotein from cyanobacteria (blue-green algae) spirulina platensis has been solved by molecular replacement technique. the crystals belong to space group p2(1) with cell parameters a = 107.20, b = 115.40, c = 183.04 a; beta = 90.2 degrees. the structure has been refined to a crystallographic r factor of 19.2% (r(free) = 23.9%) using the x-ray diffraction data extending up to 2.2 a resolution. the asymmetric unit of the crystal ce ... | 2001 | 11352634 |
| identification of anatoxins in blue-green algae food supplements using liquid chromatography-tandem mass spectrometry. | blue-green algae (cyanobacteria) in tablets and capsules, which are marketed as health food supplements, were investigated for the presence of neurotoxins related to anatoxin-a. these neurotoxins, which are nicotinic agonists, were investigated using isocratic micro-liquid chromatograph-tandem mass spectrometry (micro-lc-ms-ms). the investigated compounds were anatoxin-a and homoanatoxin-a, together with their degradation products, dihydroanatoxin-a, epoxyanatoxin-a, dihydrohomoanatoxin-a and ep ... | 2001 | 11407751 |
| the toxins of cyanobacteria. | cyanobacteria, formerly called "blue-green algae", are simple, primitive photosynthetic microorganism wide occurrence in fresh, brackish and salt waters. forty different genera of cyanobacteria are known and many of them are producers of potent toxins responsible for a wide array of human illnesses, aquatic mammal and bird morbidity and mortality, and extensive fish kills. these cyanotoxins act as neurotoxins or hepatotoxins and are structurally and functionally diverse, and many are derived fro ... | 2001 | 11488138 |
| determination of microcystins in blue-green algae, fish and water using liquid chromatography with ultraviolet detection after sample clean-up employing immunoaffinity chromatography. | anti-microcystin lr immunnoaffinity cartridges were evaluated for their ability to selectively remove microcystins from extracts of blue-green algae, fish and water samples for subsequent analysis by liquid chromatography with uv absorbance detection at 238 nm. blue-green algae and fish samples were extracted with 75% methanol in water. a portion of the extract was diluted and passed through an immunoaffinity cartridge. water samples were applied directly to the cartridge. the cartridge was rins ... | 2001 | 11486855 |
| on the origin of mitosing cells. 1967 | a theory of the origin of eukaryotic cells ("higher" cells which divide by classical mitosis) is presented. by hypothesis, three fundamental organelles: the mitochondria, the photosynthetic plastids and the (9+2) [9(2)+2] basal bodies [kinetosomes] of flagella [undulipodia] were themselves once free-living (prokaryotic) cells. the evolution of photosynthesis under the anaerobic [anoxic] conditions of the early atmosphere to form anaerobic bacteria, photosynthetic bacteria and eventually blue-gre ... | 1993 | 11541390 |
| on the origin of mitosing cells | a theory of the origin of eukaryotic cells ("higher" cells which divide by classical mitosis) is presented. by hypothesis, three fundamental organelles: the mitochondria, the photosynthetic plastids and the (9+2) basal bodies of flagella were themselves once free-living (prokaryotic) cells. the evolution of photosynthesis under the anaerobic conditions of the early atmosphere to form anaerobic bacteria, photosynthetic bacteria and eventually blue-green algae (and protoplastids) is described. the ... | 1967 | 11541392 |
| anopheles albimanus (diptera: culicidae) and cyanobacteria: an example of larval habitat selection. | northern belize has extensive herbaceous wetlands. those dominated by sparse emergent macrophytes, rushes (eleocharis spp.) and sawgrass (cladium jamaicense crantz), often develop floating mats of cyanobacteria (blue-green algae). these mats provide suitable habitat for larvae of the malaria transmitting mosquito anopheles albimanus wiedemann. presence/absence of a. albimanus larvae and cyanobacterial mats was assessed in marshes located throughout northern belize. of the 21 marshes examined dur ... | 1996 | 11540613 |
| comparison of liquid chromatography/mass spectrometry, elisa, and phosphatase assay for the determination of microcystins in blue-green algae products. | more than 100 samples of blue-green algae products (consisting of aphanizomenon, spirulina, and unidentified blue-green algae) in the form of pills, capsules, and powders were collected from retail outlets from across canada. the samples were extracted with 75% methanol in water and centrifuged to remove solids. aliquots of the extracts along with spiked blank sample extracts were sent to each participating laboratory and independently analyzed for microcystins by enzyme-linked immunosorbent ass ... | 2001 | 11501902 |
| development of a fluorescence based high throughput assay for antagonists of the human chorionic gonadotropin receptor extracellular domain: analysis of peptide inhibitors. | a simple method for prompt fluorescent detection of inhibitors of human chorionic gonadotropin (hcg) binding to the extracellular domain of the human luteinizing hormone/chorionic gonadotropin (hlh/cg) receptor was developed for high throughput screening (hts). construction and analysis of a recombinant phage that displays the extracellular binding domain of the hlh/cg receptor on its surface and specifically binds hcg was previously described. to facilitate the identification of molecules that ... | 2001 | 11689111 |
| water-quality control, monitoring and wastewater treatment in lithuania 1950 to 1999. | the lithuanian water-management system developed on the basis of soviet regulations in 1950-1990. surface-water quality monitoring started in the 1950s, and the system was improved in the 1960s. today, 48 rivers are being monitored using up to 70 parameters. statutory monitoring of discharges started in 1962, wastewater standards were issued in 1957 and 1966, and then revised in 1996. wastewater-treatment plants were built first in rural areas, in factories since the 1950s, and later in towns. s ... | 2001 | 11697266 |
| elevated co2: impact on diurnal patterns of photosynthesis in natural microbial ecosystems. | algae, including blue-green algae (cyanobacteria), are the major source of fixed carbon in many aquatic ecosystems. previous work has shown that photosynthetic carbon fixation is often enhanced in the presence of additional carbon dioxide (co2). this study was undertaken to determine if this co2 fertilization effect extended to microbial mats, and, if so, at what times during the day might the addition of co2 affect carbon fixation. four microbial mats from diverse environments were selected, in ... | 1994 | 11538022 |
| critical role of reactive oxygen species formation in microcystin-induced cytoskeleton disruption in primary cultured hepatocytes. | cyanobacteria (blue-green algae)-contaminated water is a worldwide public health problem. microcystins are a group of liver-specific toxins generated by cyanobacteria. it is generally believed that the protein phosphorylation that leads to the disruption of intermediate filaments plays an important role in microcystin-induced hepatotoxicity. however, the mechanisms that contribute to the microcystin-induced alterations of microtubules and microfilaments are not fully understood. in the present s ... | 2001 | 11732701 |
| spatial impact of the oder river plume on water quality along the south-western baltic coast. | the oder (odra) river is the most important nutrient source and pollutant for the south-western baltic sea. adjacent german-polish coastal waters, the oder (szczecin) lagoon and the oder (pomeranian) bight therefore suffer from severe eutrophication and water quality problems. at the same time, summer (bathing) tourism is the most important economical factor in this coastal zone, especially on the islands of usedom and wolin. on the basis of model simulations and remote sensing data we analysed ... | 2001 | 11759158 |
| analysis of cyanobacterial toxins by physicochemical and biochemical methods. | cyanobacteria (blue-green algae) produce a wide range of low molecular weight metabolites that include potent neurotoxins, hepatotoxins, and cytotoxins. the accumulation of such toxins in freshwaters, and in brackish and marine waters presents hazards to human and animal health by a range of exposure routes. a review is presented of developments in the detection and analysis of cyanobacterial toxins, other than bioassays, including application of physicochemical, immunoassays, and enzyme-based m ... | 2001 | 11601485 |
| [effect of blue-green alga (cyanobacteria) and their exometabolites on formation of resting forms and variability of yersinia pseudotuberculosis]. | research, carried out with the use of bacteriological methods and polymerase chain reaction, revealed that the transformation of y. pseudotuberculosis, associated with blue-green algae anabaena variabilis, into resting (noncultivable) forms took shorter time than in soil extract containing no algae. the exometabolites of "old" cultures of these algae sharply accelerated the formation of resting y. pseudotuberculosis forms. the influence of the algae and the products of their metabolism was manif ... | 2001 | 11550552 |
| partitioning of monomethylmercury between freshwater algae and water. | phytoplankton-water monomethylmercury (mehg) partition constants (kpi) have been determined in the laboratory for two green algae selenastrum capricornutum and cosmarium botrytis, the blue-green algae schizothrix calcicola, and the diatom thallasiosira spp., algal species that are commonly found in natural surface waters. two methods were used to determine kpi, the freundlich isotherm method and the flow-through/dialysis bag method. both methods yielded kpi values of about 10(6.6) for s. caprico ... | 2001 | 11718342 |
| acyl group specificity at the active site of tetrahydridipicolinate n-succinyltransferase. | tetrahydrodipicolinate n-succinyltransferase (dapd) catalyzes the succinyl-coa-dependent acylation of l-2-amino-6-oxopimelate to 2-n-succinyl-6-oxopimelate as part of the succinylase branch of the meso-diaminopimelate/lysine biosynthetic pathway of bacteria, blue-green algae, and plants. this pathway provides meso-diaminopimelate as a building block for cell wall peptidoglycan in most bacteria, and is regarded as a target pathway for antibacterial agents. we have solved the x-ray crystal structu ... | 2002 | 11910040 |
| effect of various foods on biomphalaria alexandrina and bulinus truncatus and their susceptibility to schistosome miracidia. | the tested foods are tropical fish food (tetramine), rat food, blue green algae, dried lettuce leaves and a mixture of all these foods. the results indicated that feeding of b. alexandrina on a mixture of foods increased their growth and survival rates and their susceptibility to s. mansoni. tetramine elevated the egg-laying capacity of snails compared to other tested foods. the hatchability of eggs of b. alexandrina fed on algae for a period of 16 weeks showed the highest rate followed by snail ... | 2001 | 11775118 |
| factors influencing the abundance of japanese encephalitis vectors in ricefields in india--ii. biotic. | the relationship of insect predators and phytoplankton with the abundance of culex tritaeniorhynchus giles, cx. vishnui theobald and cx. pseudovishnui colless mosquito larvae and pupae (diptera: culicidae) in ricefields was investigated during three rice growing seasons. notonectids were the most abundant insect predators, whereas diatoms dominated among phytoplankton. multiple regression analysis showed that the occurrence of notonectids (both nymphs and adults) was negatively associated with l ... | 2002 | 11963972 |
| congener-independent immunoassay for microcystins and nodularins. | cyanobacteria (blue-green algae) (e.g., microcystis and nodularia spp.) capable of producing toxic peptides are found in fresh and brackish water worldwide. these toxins include the microcystin (mc) heptapeptides (>60 congeners) and the nodularin pentapeptides (ca. 5 congeners). cyanobacterial cyclic peptide toxins are harmful to man, other mammals, birds, and fish. acute exposure to high concentrations of these toxins causes liver damage, while subchronic or chronic exposure may promote liver t ... | 2001 | 11775161 |
| integration of aquatic fate and ecological responses to linear alkyl benzene sulfonate (las) in model stream ecosystems. | an integrated model stream ecosystem fate and effect study of dodecyl linear alkylbenzene sulfonate (c(12)las) was performed in the summer and fall of 1996. the study addressed responses of periphytic microbes, immature benthic fauna including abundance, drift, and emergence of adult insects in a 56-day exposure. exposures ranged from 126 to 2978 microg/l and were continuously presented in a single-pass, flow-through test system. microbial heterotrophs acclimated to c(12)las exposure quickly (14 ... | 2002 | 12061833 |
| free and total amino acid composition in blue-green algae. | a simple, accurate and reproducible analytical method is described for the extraction and the simultaneous determination of 18 amino acids in different for geographical origin spirulina alga samples using phenylisothiocianate as derivatizating agent in natural feed. the best experimental hydrolysis conditions have been studied varying the temperature, the time and the hydrolyzing reagent. the separation and the quantitative analysis of the by-products have been carried out by hplc analysis and u ... | 2002 | 12073880 |
| sources of the eutrophication problems associated with toxic algae: an overview. | blooms of cyanobacteria (toxic blue-green algae) can produce health and environmental hazards in water, including water used for drinking or recreational purposes. how, why, and when these blooms are produced, as well as how to deal with them, are questions whose answers are vital to the safeguarding of public health in regions where the algae occur. the blooms are linked to eutrophication of water, and this paper discusses the eutrophication problems, their nature, and their relevance to the pr ... | 2001 | 11764678 |
| experimental substantiation of the possibility of developing selenium- and iodine-containing pharmaceuticals based on blue-green algae spirulina platensis. | the great potential of using blue-green algae spirulina platensis as a matrix for the production of selenium- and iodine-containing pharmaceuticals is shown experimentally. the background levels of 31 major, minor and trace elements (na, mg, al, cl, k, ca, sc, v, cr, mn, fe, co, ni (using (n,p) reaction), as, br, zn, rb, mo, ag, sb, i, ba, sm, tb, tm, hf, ta, w, au, hg, th) in s. platensis biomass were determined by means of epithermal neutron activation analysis. the dependence of selenium and ... | 2002 | 12151068 |
| effects of enteric bacterial and cyanobacterial lipopolysaccharides, and of microcystin-lr, on glutathione s-transferase activities in zebra fish (danio rerio). | cyanobacteria (blue-green algae) can produce a variety of toxins including hepatotoxins e.g. microcystins, and endotoxins such as lipopolysaccharides (lps). the combined effects of such toxins on fish are little known. this study examines the activities of microsomal (m) and soluble (s) glutathione s-transferases (gst) from embryos of the zebra fish, danio rerio at the prim six embryo stage, which had been exposed since fertilisation to lps from different sources. a further aim was to see how ac ... | 2002 | 12200087 |
| geographic information system based manure application plan. | a geographic information system (gis) based manure application plan has been developed for the site-specific application of animal waste to agricultural fields in the westbrook sub-catchment of the murray-darling basin, south-east queensland, australia. sites suitable for animal waste application were identified using a gis based weighted linear combination (wlc) model. the degree of land suitability for animal waste application was determined using a range of social, economic, environmental, an ... | 2002 | 11995243 |
| structures of the complexes of a potent anti-hiv protein cyanovirin-n and high mannose oligosaccharides. | the development of anti-human immunodeficiency virus (hiv) microbicides for either topical or ex vivo use is of considerable interest, mainly due to the difficulties in creating a vaccine that would be active against multiple clades of hiv. cyanovirin-n (cv-n), an 11-kda protein from the cyanobacterium (blue-green algae) nostoc ellipsosporum with potent virucidal activity, was identified in the search for such antiviral agents. the binding of cv-n to the heavily glycosylated hiv envelope protein ... | 2002 | 12110688 |
| involvement of the hap gene (mucinase) in the survival of vibrio cholerae o1 in association with the blue-green alga, anabaena sp. | mucinase is a soluble haemagglutinin protease, which may be important for the survival of vibrio cholerae in association with mucilaginous blue-green algae (cyanobacteria). a comparative survival study was carried out with an anabaena sp. and a wild-type v. cholerae o1 strain hap+ gene (haemagglutinin-protease), together with its isogenic mutant hap (hap-deleted gene). a simple spread plate technique was followed to count culturable v. cholerae o1 on taurocholate tellurite gelatin agar plate. th ... | 2002 | 12455611 |
| [ultrastructure of yersinia pseudotuberculosis in the process of their reversible transition into the dormant (non-culturable) state in association with blue-green algae]. | the ultrastructural organization of y. pseudotuberculosis in the process of the transition of vegetative cells into the dormant (noncultivable) state in interaction with blue-green algae of the species anabaena variabilis was studied by the method of transmission electron microscopy. the use of type specific y. pseudotuberculosis serum made it possible to identify y. pseudotuberculosis cells in the bacterial association and to find out whether their antigenic properties remained intact in time. ... | 2002 | 11949247 |
| trophic relations in two lakes from the bulgarian black sea coast and possibilities for their restoration. | based on quantitative data on nutrients, light penetration, phytoplankton, zooplankton and zoobenthos obtained in the period 1992-1994 the relations between trophic levels were studied by means of statistical analysis. the two lakes are distinguished by relatively high transfer efficiency between phytoplankton and zooplankton, which depends on the size distribution among zooplankton and percentage of blue-green algae. the bottom up influence seems to prevail over the top-down influence, water su ... | 2002 | 12420960 |
| kinetics and uptake mechanisms for monomethylmercury between freshwater algae and water. | uptake kinetics of monomethylmercury chloride (mehgcl) were measured for two species of green algae (selenastrum capricomutum and cosmarium botrytis), one blue-green algae (schizothrix calcicola), and one diatom (thalassiosira weissflogii), algal species that are commonly found in natural surface waters. species differences were found with the two green algae giving the highest uptake rates, and one of them (cosmarium) showing differences between cultures having widely different cell age (expone ... | 2002 | 12214648 |
| a butyrylcholinesterase in the early development of the brine shrimp (artemia salina) larvae: a target for phthalate ester embryotoxicity? | the phthalate ester insensitive blue-green algae (synechococcus lividus) were used as a food source to extend the survival of synchronously hatched brine shrimp (artemia salina) larvae allowing measurement of a reduced toxic response to phthalate esters at late post-hatching stages of development. the maximum acute toxicity due to di-n-butyl phthalate (dnbp) correlated with the expression of a phthalate ester-hydrolyzing enzyme. the purified enzyme was identified as a butyrylcholinesterase due t ... | 2002 | 12459190 |
| toxins and bioactive compounds from cyanobacteria and their implications on human health. | many species of cyanobacteria (blue-green algae) produce secondary metabolites with potent biotoxic or cytotoxic properties. these metabolites differ from the intermediates and cofactor compounds that are essential for cell structural synthesis and energy transduction. the mass growth of cyanobacteria which develop in fresh, brackish and, marine waters commonly contain potent toxins. cyanobacterial toxins or cyanotoxins are responsible for or implicated in animal poisoning, human gastroenteritis ... | 2002 | 12597562 |
| the insecticidal activity of cyanobacteria against four insects, two of medical importance and two agricultural pests with reference to the action on albino mice. | acute lethal toxicity of cyanobacteria (blue-green algae) was investigated against 3rd larval stages of musca domestica, and culex pipiens, and 4th larval stages of spodoptera littoralis and agrotis ipsilon. the ld50s were 1.94, 2.33, 7.59 and 9.10 microg for m. domestica, c. pipiens, s. littoralis and a. ipsilon respectively. the slope functions were 4,045 +/- 0.332 (m. domestica), 4.122 +/- 0.336 (c. pipiens), 4.15 +/- 0.35 (s. littoralis) and 3.72 +/- 0.34 (a. ipsilon). these ld50s markedly a ... | 1999 | 12561932 |
| inhibition of enterovirus 71-induced apoptosis by allophycocyanin isolated from a blue-green alga spirulina platensis. | enterovirus 71 infection causes significant morbidity and mortality in children, yet there is no effective treatment. in this study, a protein-bound pigment, allophycocyanin purified from blue-green algae is first reported to exhibit anti-enterovirus 71 activity. allophycocyanin neutralized the enterovirus 71-induced cytopathic effect in both human rhabdomyosarcoma cells and african green monkey kidney cells. the 50% inhibitory concentration of allophycocyanin for neutralizing the enterovirus 71 ... | 2003 | 12629652 |
| cyst-based toxicity tests. xi. influence of the type of food on the intrinsic growth rate of the rotifer brachionus calyciflorus in short-chronic toxicity tests. | as important members of zooplankton communities worldwide, rotifers are used extensively in ecotoxicological research. chronic rotifer tests are, however, dependent on live algal food which adds to the complexity, the variability and the costs of these bioassays. to bypass the former problem, experiments have been undertaken with the freshwater rotifer brachionus calyciflorus, to determine their intrinsic growth rate (r) when fed for 48 h on a mixture of green algae (raphidocelis subcapitata rec ... | 2003 | 12656256 |
| on the natural diet of daphnia laevis in the eutrophic pampulha reservoir (belo horizonte, minas gerais). | the aim of this study was to assess the major food items ingested by adult specimens of daphnia laevis within the eutrophic pampulha reservoir in belo horizonte, minas gerais, brazil. the gut content was analyzed after addition of sodium hypochlorite and also through the examination of dissected guts under scanning electron microscopy. the results showed that chlorophyceae was the main food item ingested, representing c. 80.5% of the total ingested food. moreover, eutetramorus fottii, coelastrum ... | 2002 | 12530180 |
| c-phycocyanin, a selective cyclooxygenase-2 inhibitor, induces apoptosis in lipopolysaccharide-stimulated raw 264.7 macrophages. | c-phycocyanin (c-pc) is one of the major biliproteins of spirulina platensis, a blue green algae, with antioxidant and radical scavenging properties. it is also known to exhibit anti-inflammatory and anti-cancer properties. however, the mechanism of action of c-pc is not clearly understood. previously, we have shown that c-pc selectively inhibits cyclooxygenase-2 (cox-2), an inducible isoform that is upregulated during inflammation and cancer. in view of the reported induction of apoptosis in ca ... | 2003 | 12711327 |
| interaction between microcystins of different hydrophobicities and lipid monolayers. | microcystins (mc) are a group of amphiphatic peptide hepatotoxins and protein phosphatase inhibitors produced by certain cyanobacteria (blue-green algae). microcystins are believed to require an active transport mechanism to penetrate the plasma membranes of animal cells. in this study the surface barostat technique showed that two more hydrophobic microcystins mc-lf, containing leu and phe, and mc-lw, containing leu and trp, had a higher surface activity on an egg phosphatidylcholine-cholestero ... | 2003 | 12565758 |
| harmful freshwater algal blooms, with an emphasis on cyanobacteria. | suspended algae, or phytoplankton, are the prime source of organic matter supporting food webs in freshwater ecosystems. phytoplankton productivity is reliant on adequate nutrient supplies; however, increasing rates of nutrient supply, much of it manmade, fuels accelerating primary production or eutrophication. an obvious and problematic symptom of eutrophication is rapid growth and accumulations of phytoplankton, leading to discoloration of affected waters. these events are termed blooms. bloom ... | 2001 | 12805693 |
| multiple splice variants encode a novel adenylyl cyclase of possible plastid origin expressed in the sexual stage of the malaria parasite plasmodium falciparum. | we report the characterization of an unusual adenylyl cyclase gene from plasmodium falciparum, here designated pfacalpha. the level of mrna expression is maximum during development of gametocytes (the sexual blood stage of the parasite life cycle). the gene is highly interrupted by 22 introns, and reverse transcriptase-pcr analysis revealed that there are multiple mrna splice variants. one intron has three alternative 3'-splice sites that confer the potential to encode distinct forms of the enzy ... | 2003 | 12668669 |
| cyanopeptide analogues: new lead structures for the design and synthesis of new thrombin inhibitors. | this contribution deals with the structure-based design and syntheses of the new serine protease inhibitors ra-1001 and ra-1002, which are analogues of the blue-green algae derived cyanopeptide aeruginosin 98-b. both compounds inhibit thrombin with ki values of 5.6 microm and 8.7 microm, respectively. | 2002 | 12611274 |
| cyanobacterial toxins: a growing environmental concern. | unusual blooms of toxic cyanobacteria in water bodies have drawn attention of environmentalists world over. major blooms of anabaena, microcystis and nodularia in water storage reservoirs, rivers and lakes leading to adverse health effects have been reported from australia, england and many other parts of the world. an overview of the morphology and taxonomy of these toxic blue-green algae; their possible sources of contamination including dietary supplements and their potential to cause hepatot ... | 2003 | 12729683 |
| cutaneous sensitization to blue-green algae. | | 1953 | 13084359 |
| development of toxicity in blue-green algae. | | 1953 | 13094595 |
| relation between pigment content and photosynthetic characteristics in a blue-green algae. | 1. the blue-green alga anacystis nidulans was cultured under steady state conditions at 25 and 39 degrees c. and under several different light intensities to give five different types of cells. 2. cells were submitted to pigment analysis based upon acetone extracts and aqueous extracts obtained by sonic disintegration. the different cell types show a threefold range of chlorophyll content and a fourfold range of phycocyanin content with only minor changes in the chlorophyll/phycocyanin ratio. ce ... | 1955 | 13252232 |
| delayed light production by blue-green algae, red algae, and purple bacteria. | 1. blue-green algae, red algae, and purple bacteria all show the emission of delayed light. 2. the action spectra for the production of delayed light by three species of blue-green algae have one broad band with a peak at 620 mmicro. 3. the action spectrum for production of delayed light by the red algae has one peak at 550 mmicro with a shoulder from 600 to 660 mmicro. 4. the emission spectra of the delayed light from both the blue-green and red algae were the same as from the green algae, chlo ... | 1956 | 13286450 |
| the comparative physiology and biochemistry of the blue-green algae. | | 1956 | 13363770 |
| periodic phenomena in photosynthesis as reflected by oxygen exchange of blue-green algae. | | 1957 | 13436453 |
| light-dark transients in oxygen exchange of blue-green algae. | | 1957 | 13436454 |
| a simple method of staining nuclei-like bodies in bacteria and blue-green algae with celestine blue b-iron. | | 1957 | 13451200 |
| the nature and distribution of carotenoids in some blue-green algae. | | 1957 | 13481328 |
| delayed light action spectra of several algae in visible and ultraviolet light. | action spectra for delayed light production by several algae were determined from 250 to 750 mmicro incident light. in the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. blue-green algae had a maximum at 620 mmicro, red algae at 550 mmicro, whereas green and brown algae have action spectra corresponding to chlorophyll and carotenoid absorption. in the ultraviolet portion of the spectrum delayed light is emitte ... | 1958 | 13587909 |
| effects of extracts of blue-green algae on pigment production by serratia marcescens. | | 1959 | 13664907 |
| electron microscope studies on blue-green algae. | several species of blue-green algae were studied in thin sections with the electron microscope. our electron micrographs confirm the view that the cell of blue-green algae is different and simpler in organization than the typical plant or animal cell. on the other hand, the general pattern of ultrastructure is the same as that found in bacteria and streptomyces. the cell boundary is formed by a double membrane which consists of two typical unit membranes. situated in between these membranes is t ... | 1961 | 13741827 |
| isolation of bacteria-free cultures from hormogone-producing blue-green algae. | | 1961 | 13874676 |
| preliminary note on a new phycobilin pigment isolated from blue-green algae. | | 1962 | 13895764 |
| [studies on morphologically-differentiated cells in developing cultures of blue-green algae with the aid of triphenyl-tetrazolium chloride]. | | 1962 | 13903104 |
| physiological and biochemical studies on nitrogen fixing blue-green algae. i. on the nature of cellular and extracellular nitrogenous substances formed by nostoc commune. | | 1962 | 13918955 |
| physiological and biochemical studies on nitrogen fixing blue-green algae. | | 1962 | 13918956 |
| use of antibiotics to purify blue-green algae. | | 1961 | 13920023 |
| laboratory studies on the toxins produced by waterblooms of blue-green algae. | | 1962 | 13949274 |
| photochemical reduction of triphosphopyridine nucleotide by cell-free extracts of blue-green algae. | | 1963 | 13971359 |
| algal virus: isolation. | freshwater blue-green algae of the genera lyngbya, plectonema, and phormidium are susceptible to a virus recently isolated from a waste-stabilization pond. electron micrographs of a partially purified preparation show that the viral particle has an icosahedral structure about 66 mmicro in diameter. | 1963 | 13976026 |
| physiological and biochemical studies on nitrogen fixation by blue-green algae. iii. the growth and nitrogen fixation of nostoc commune as influenced by culture conditions. | | 1963 | 13980209 |
| morphology of representative blue-green algae. | | 1963 | 14018053 |
| a study of several blue-green algae in the electron microscope. | | 1962 | 14020147 |
| the action of lysozyme on several blue-green algae. | | 1962 | 14023796 |
| characteristics of marine blue-green algae with uric acid as nitrogen source. | | 1963 | 14058996 |
| [the effect of concentration of different components of the medium on the growth and nitrogen fixation by blue-green algae]. | | 1963 | 14074532 |
| ultrastructural studies on the blue-green algal symbiont in cyanophora paradoxa korschikoff. | studies conducted on the ultrastructure of cyanophora paradoxa korschikoff (a cryptomonad) have shown that its intracellular symbiont is closely related to unicellular blue-green algae. due to its peculiar habitat, the intracellular symbiont lacks the characteristic cyanophycean double-layered cell wall, but is surrounded by a thin protoplasmic membrane. the protoplasm itself is differentiated into a lamellated chromatoplasm containing photosynthetic pigments, polyphosphate granules, and possibl ... | 1963 | 14086136 |
| intramitochondrial fibers with dna characteristics. i. fixation and electron staining reactions. | chick embryo mitochondria, studied with the electron microscope, show crista-free areas of low electron opacity. these areas are observable after fixation with osmium tetroxide, calcium permanganate, potassium permanganate, formaldehyde, acrolein, acrolein followed by osmium tetroxide, uranyl acetate followed by calcium permanganate, and acetic acid-alcohol. staining of sections with lead hydroxide or uranyl acetate, or with both, resulted in an increased density of a fibrous material within the ... | 1963 | 14086138 |
| [nitrogen fixation in blue-green algae]. | | 1963 | 14093557 |
| liberation of extracellular nitrogen by 2 nitrogen-fixing blue-green algae. | | 1963 | 14097731 |
| [the effect of hydrogen-ion concentration (ph) in the medium and temperature on the growth and nitrogen fixation of blue-green algae]. | | 1963 | 14137792 |