| morphology of representative blue-green algae. | | 1963 | 14018053 |
| a study of several blue-green algae in the electron microscope. | | 1962 | 14020147 |
| absence of sterols in blue-green algae. | | 1964 | 14168239 |
| light-induced absorption-change transients in some blue-green algae. | | 1964 | 14197380 |
| studies on photosynthesis using cell free preparations of blue-green algae. | | 1964 | 14211158 |
| [the effect of nitrogen compounds on the growth of blue-green algae and their fixation of molecular nitrogen]. | | 1964 | 14237035 |
| the relationship between blue-green algae and bacteria. | | 1965 | 14296764 |
| spectrophotometric evidence for the participation of a quinone in photosynthesis of intact blue-green algae. | | 1964 | 14163511 |
| [nitrogen fixation in blue-green algae]. | | 1963 | 14093557 |
| new cyanopeptide-derived low molecular weight thrombin inhibitors. | thrombosis is the result of defective regulation of the hemostasis system. this cardiovascular disorder may lead to deep vein thrombosis, myocardial infarction, and stroke. the majority of current drug research is focused on finding inhibitors of thrombin - the global player in hemostasis. in our work, we emphasize investigation of the marine environment to yield new lead structures from marine organisms like blue-green algae (cyanobacteria). this article deals with the design, syntheses, and in ... | 2003 | 14502757 |
| aquatic macrophytes as feeding site for small fishes in the rosana reservoir, paranapanema river, southeastern brazil. | in the present investigation we studied the feeding habits of the fishes associated with aquatic macrophytes in the rosana reservoir, southeastern brazil. twenty fish species were collected during four field trips, regularly distributed across the dry and wet seasons. focal snorkeling observations of the fishes were made over a total of six hours. nine species were present in abundances of more than 1% and, therefore, had their feeding habits analyzed. hemigrammus marginatus, roeboides paranensi ... | 2003 | 14509843 |
| biotechnological uses of cyanobacteria. | cyanobacteria (blue-green algae) are o(2)-evolving photosynthesizing prokaryotes that have an extensive history of use as a human food source and as a fertilizer in rice fields. they have also been recognized as an excellent source of vitamins and proteins and as such are found in health food stores in north america and elsewhere. cyanobacteria have a great deal of potential as a source of fine chemicals, as a biofertilizer and as a source of renewable fuel. this potential is being realized as d ... | 1985 | 14544049 |
| phycocyanin-mediated apoptosis in ak-5 tumor cells involves down-regulation of bcl-2 and generation of ros. | c-phycocyanin, which is a major biliprotein of the blue-green algae, has been shown to possess cyclooxygenase-2 inhibitory activity. we have studied the effect of phycocyanin on a rat histiocytic tumor line. ak-5 cells are induced into apoptotic death program when treated with phycocyanin, which involves the activation of caspase-3. phycocyanin-mediated apoptotic death is induced through the generation of reactive oxygen radicals. free radical scavengers inhibited phycocyanin-induced apoptotic d ... | 2003 | 14617790 |
| genotoxicity of microcystin-lr in human lymphoblastoid tk6 cells. | toxic cyanobacteria (blue-green algae) water blooms have become a serious problem in several industrialized areas of the world. microcystin-lr (mclr) is a cyclic heptapeptidic toxin produced by the cyanobacteria. in the present study, we used human lymphoblastoid cell line tk6 to investigate the in vitro genotoxicity of mclr. in a standard 4h treatment, mclr did not induce a significant cytotoxic response at <80 microg/ml. in a prolonged 24h treatment, in contrast, it induced cytotoxic as well a ... | 2004 | 14706513 |
| hypomagnesemia among cows in a confinement-housed dairy herd. | between january and march 2002, 55 cows in a 1,200-cow commercial dairy herd in south florida died. most of the cows that were found dead did not have any clinical signs of disease prior to death. because of a history of a feed change, a bloom of blue-green algae in cow cooling ponds, and initial necropsy findings of moderate enteritis, the preliminary differential diagnosis included clostridial enteritis, blue-green algae toxicosis, and mycotoxicosis. rumen acidosis, hypomagnesemia, and heavy m ... | 2004 | 14710884 |
| chlorination for degrading saxitoxins (paralytic shellfish poisons) in water. | chlorination was investigated as a treatment option for degrading and thus removing saxitoxins (paralytic shellfish poisons, psps) produced by cyanobacteria (blue-green algae) from water. it was found to be effective with the order of ease of degradation of the saxitoxins being gtx5 (b1) approximately dcstx > stx > gtx3 approximately c2 > c1 > gtx2. however the effectiveness of chlorine was ph dependent. degradation as a function of ph was not linear with the degree of degradation increasing rap ... | 2003 | 14733387 |
| aqueous chlorophyll preparations from blue-green algae. | | 1950 | 14791538 |
| extracellular polysaccharides of algae: effects on life-support systems. | the amount of extracellular polysaccharide produced by eight species of green and blue-green algae ranges from 174 milligrams per liter to 557 milligrams per liter. most of the polymers are composed of four monosaccharides: a hexose, a pentose, a methyl pentose, and uronic acid. the production of excessive amounts of these photosynthetic end products will undoubtedly influence the effective recycling time of growth media in life-support systems. | 1964 | 14163784 |
| light-induced changes in absorbancy and fluorescence of chlorophyllous pigments associated with the pigment systems 1 and 2 in blue-green algae. | | 1965 | 14314345 |
| revegetating fly ash landfills with prosopis juliflora l.: impact of different amendments and rhizobium inoculation. | a revegetation trial was conducted to evaluate the feasibility of growing a legume species, prosopis juliflora l., on fly ash ameliorated with combination of various organic amendments, blue-green algal biofertilizer and rhizobium inoculation. significant enhancements in plant biomass, photosynthetic pigments, protein content and in vivo nitrate reductase activity were found in the plants grown on ameliorated fly ash in comparison to the plants growing in unamended fly ash or garden soil. higher ... | 2004 | 14987858 |
| characterizing algogenic organic matter (aom) and evaluating associated nf membrane fouling. | occasional algal blooms, comprised of blue-green algae and/or green algae, cause significant challenges in drinking water treatment due to the release of algogenic organic matter (aom) into water extracellularly and, upon cell lysis, intracellularly. aom has been extracted from blue-green algae (cyanobacteria) by various means and analyzed by uv absorbance scanning, hpsec-uv-fluorescence-doc, uv absorbance ratio index (uri), ftir, and fluorescence excitation emission matrix (eem). aom extracted ... | 2004 | 15016519 |
| the respiratory chain of blue-green algae (cyanobacteria). | electron transport components on the way from reduced substrates to the terminal respiratory oxidase(s) are discussed in relation to analogous and/or homologous enzymes and electron carriers in the generally much better known bacteria, mitochondria and chloroplasts. the kinetic behaviour of the components, their localization within the cell and their evolutionary position are given special attention. pertinent results from molecular genetics are also mentioned. the unprecedented role of cyanobac ... | 2004 | 15032833 |
| synthesis of pyrazole derivatives and their evaluation as photosynthetic electron transport inhibitors. | two series of new pyrazoles, namely six pyrazolo[1,5-a][1,3,5]triazine-2,4-dione and four pyrazolo[1,5-c][1,3,5]thiadiazine-2-one derivatives, were synthesized as potential inhibitors of the photosynthetic electron transport chain at the photosystem ii level. the compounds were confirmed by 1h nmr, elemental, and ir analyses. their biological activity was evaluated in vivo upon both the growth of blue-green algae and the photosynthetic oxygen evolution by eukaryotic algae and in vitro as the abi ... | 2004 | 15053526 |
| use of freshwater plants for phytotoxicity testing: a review. | phytotoxicity data for aquatic plants have served a relatively minor role in regulatory decisions concerning the environmental hazard of most potential contaminants. a variety of phytotoxicity tests have been conducted with freshwater green algae, duckweed, blue-green algae, diatoms and rooted macrophytes (whole plants and seeds). several test methods have been standardized for microalgae which are used primarily with chemicals, effluents, contaminated sediment elutriates and hazardous waste lea ... | 1995 | 15091582 |
| effects of pulp mill chlorate on baltic sea algae. | the long-term effects of pulp mill chlorate on different algal species of the baltic sea were studied in land-based model ecosystems simulating the littoral zone. brown algae (phaeophyta) exhibited an extraordinarily high sensitivity to chlorate and pulp mill effluents containing chlorate. all brown algal species ceased growth or showed major signs of toxicity at all concentrations tested, down to microgram per litre levels. ec50 levels for growth of fucus vesiculosus were about 80-100 microg cl ... | 1994 | 15091680 |
| seasonal changes in an intertidal community affected by sewage pollution. | seasonal changes in structure of a rocky intertidal community affected by sewage pollution at quequén (argentina) were studied over a period of 2 years. most species showed a decrease in cover values in the polluted area. on the other hand, a small proportion of organisms favoured by organic enrichment predominated around the outfall during the period of study. community structure was not significantly altered by frosts or windstorms. desiccation is identified as the main physical stress. a comb ... | 1993 | 15091785 |
| uptake of dieldrin, dimethoate and permethrin by cyanobacteria, anabaena sp. and aulosira fertilissima. | blue-green algae showed a poor ability to pick up and concentrate dieldrin and dimethoate. however, the uptake and bioconcentration factor for permethrin was very high. the uptake of dieldrin by anabaena and aulosira ranged from 5.1 to 73.2 and 5.5 to 17.4 microg g(-1) (ppm), respectively. the uptake of permethrin was from 9.0 to 249.7 and 4.6 to 1422.5 microg g(-1) by anabaena and aulosira, respectively. the highest bioconcentration factors for permethrin in anabaena and aulosira were 813 and 2 ... | 1988 | 15092535 |
| interaction of endosulfan and malathion with blue-green algae anabaena and aulosira fertilissima. | the growth of anabaena and aulosira fertilissima was adversely affected by endosulfan even at 1 microg ml(-1). the inhibition was significantly above 50% at 20 microg ml(-1) throughout the incubation. anabaena survived up to 500 microg ml(-1) of malathion, but was completely bleached in the presence of 50 microg ml(-1) of endosulfan. aulosira was more sensitive to malathion than anabaena and recovered to control levels only at 10 microg ml(-1). the morphology and hetercyst frequency were not alt ... | 1988 | 15092614 |
| bioconcentration and metabolism of ddt, fenitrothion and chlorpyrifos by the blue-green algae anabaena sp. and aulosira fertilissima. | anabaena and aulosira fertilissima showed a marked ability to accumulate ddt, fenitrothion and chlorpyrifos. although the maximum accumulation of ddt was almost the same in both organisms, there were significant differences in their abilities to accumulate fenitrothion and chlorpyrifos. patterns of uptake of ddt under different treatments were also similar in both anabaena and aulosira, but there were significant differences in the patterns of accumulation of fenitrothion between these two organ ... | 1987 | 15092729 |
| effect of nitrogen-fixing blue-green algae on the growth of rice plants. | | 1951 | 14882339 |
| sediment toxicity and community composition of benthos and colonized periphyton in the everglades-florida bay transitional zone. | this survey provides information on sediment toxicity and structural characteristics of the macrobenthic and periphytic algal communities at 10 locations in northeast florida bay. whole sediments were not acutely toxic to mysidopsis bahia (marine invertebrate) and hyalella azteca (freshwater invertebrate) relative to reference sediment. survival was between 80% and 100%. community structure of the macrobenthos and algal-periphyton varied spatially. a total of 116 benthic species were identified ... | 2004 | 15217247 |
| a randomized, placebo-controlled, crossover clinical trial of super blue-green algae in patients with essential blepharospasm or meige syndrome. | to evaluate the effectiveness of super blue-green algae (sbga) supplements on the severity of essential blepharospasm treated with botulinum toxin a injections. | 2004 | 15234278 |
| treatment of taste and odor material by oxidation and adsorption. | massive blooms of blue-green algae in reservoirs produce the musty-earthy taste and odor, which are caused by compounds such as 2-mib and geosmin. 2-mib and geosmin are rarely removed by conventional water treatment. their presence in the drinking water, even at low levels (ng/l), can be detected and it creates consumer complaints. so those concentrations have to be controlled as low as possible in the drinking water. the removals by oxidation (o3, cl2, clo2) and adsorption (pac, filter/adsorber ... | 2004 | 15237637 |
| [dynamics of the development of blue-green algae and bacteria in ponds in the environment of kiev]. | | 1964 | 14301125 |
| salubrious effect of c-phycocyanin against oxalate-mediated renal cell injury. | c-phycocyanin, a biliprotein pigment found in some blue green algae (spirulina platensis) with nutritional and medicinal properties, was investigated for its efficacy on sodium oxalate-induced nephrotoxicity in experimentally induced urolithic rats. | 2004 | 15369755 |
| a proposal for further integration of the cyanobacteria under the bacteriological code. | this taxonomic note reviews the present status of the nomenclature of the cyanobacteria under the bacteriological code. no more than 13 names of cyanobacterial species have been proposed so far in the international journal of systematic and evolutionary microbiology (ijsem)/international journal of systematic bacteriology (ijsb), and of these only five are validly published. the cyanobacteria (cyanophyta, blue-green algae) are also named under the botanical code, and the dual nomenclature system ... | 2004 | 15388760 |
| internal conversion in the photosynthetic mechanism of blue-green algae. | 1. in chroococcus a quantum of light absorbed by phycocyanin has 90 per cent the chance of doing photosynthesis that a quantum absorbed by chlorophyll has. 2. by a process analogous to internal conversion in radioactivity (but with the linear dimensions and the wave length 10(4) times larger) there will be transferred from phycocyanin to chlorophyll see pdf for equation (a number of the order of 100) quanta for every one emitted as fluorescent light by the phycocyanin in the chroococcus cell. 3. ... | 1950 | 15410487 |
| detection and analysis of the cyanobacterial peptide hepatotoxins microcystin and nodularin using seldi-tof mass spectrometry. | surface-enhanced laser desorption ionization mass spectrometry (seldi-tofms) was used to develop a new and useful method for determination and identification of the cyanobacterial (blue-green algae) toxins: microcystin and nodularin. the technique, combining chromatography and ms, enables microcystin/nodularin capture, purification, analysis, and processing from complex biological mixtures directly onto a hydrophobic chip. factors affecting ion intensities, including matrix concentration and las ... | 2004 | 15450932 |
| [variability of the clonal structure of yersinia pseudotuberculosis population under different conditions]. | in a series of experiments the dynamics of the clonal structure of y. pseudotuberculosis population was evaluated by cytopathogenicity in soil extract, as well as in associations with blue-green algae (cyanobacteria) and infusoria, under different temperature conditions. in all variants of experiments made at low environmental temperature (10 degrees c) a considerable part of y. pseudotuberculosis clones (25-40%) was found to be cytopathogenic, while at 22 degrees c such clones were absent or ha ... | 2004 | 15481916 |
| [biocenosis of the natural foci of sapronotic infections (the results of 15-year observations)]. | the summarized results of original studies, carried out in 1988-2003 by scientists of the gamaleya research institute of epidemiology and microbiology, are discussed. the part dealing with the regularity and mechanisms of the circulation of pathogenic bacteria in the biocenosis of soil and water reservoirs includes the following subjects: population and intracellular interactions with protozoa; the evaluation of different representatives of hydrobios as hosts and the transmission along trophic b ... | 2004 | 15481938 |
| isolation and characterization of a bacterium capable of removing taste- and odor-causing 2-methylisoborneol from water. | 2-methylisoborneol (mib), a metabolite of blue-green algae, has been implicated in causing unpalatable drinking water throughout the world. current non-biological water treatment technologies are ineffective in removing mib from potable water or are cost-prohibitive, and biological applications may address these problems. we have isolated and characterized a bacterium derived from lake water and capable of aerobically degrading mib. light microscopy and transmission electron microscopy revealed ... | 2004 | 15491661 |
| six years of operation of a fluidised bed reactor for denitrification. | at himmerfjärden wastewater treatment plant, a fluidised bed reactor for nitrogen removal has been operated since 1997. despite its small footprint, the system enables a far-reaching nitrogen removal. the current nitrate reduction in the reactor is 95%. the reduction of total nitrogen at the wastewater treatment plant is 80-90% at normal operation. the concentration of nitrate in the effluent is easily controlled by changing the dose of carbon. as part of a series of full-scale experiments, the ... | 2004 | 15553464 |
| [investigation of microcystin pollution on dong lake, wuhan city]. | to investigate the level of pollution of microcystin and its changing in freshwater lake and fish. | 2004 | 15098475 |
| profile of resistance of human immunodeficiency virus to mannose-specific plant lectins. | the mannose-specific plant lectins from the amaryllidaceae family (e.g., hippeastrum sp. hybrid and galanthus nivalis) inhibit human immunodeficiency virus (hiv) infection of human lymphocytic cells in the higher nanogram per milliliter range and suppress syncytium formation between persistently hiv type 1 (hiv-1)-infected cells and uninfected cd4(+) t cells. these lectins inhibit virus entry. when exposed to escalating concentrations of g. nivalis and hippeastrum sp. hybrid agglutinin, a variet ... | 2004 | 15367629 |
| acute skin irritant effects of cyanobacteria (blue-green algae) in healthy volunteers. | to assess the skin irritant potential of a range of laboratory grown cyanobacterial species using skin-patch testing on human volunteers. | 2004 | 15707167 |
| overview of key phytoplankton toxins and their recent occurrence in the north and baltic seas. | the frequency and intensity of harmful algal blooms (habs) appear to be on the rise globally. there is also evidence of the geographic spreading of toxic strains of these algae. consequently, methods had to be established and new ones are still needed for the evaluation of possible hazards caused by increased algal toxin production in the marine food chain. different clinical effects of algae-related poisoning have attracted scientific attention; paralytic shellfish poisoning, diarrhetic shellfi ... | 2005 | 15712332 |
| occurrence and elimination of cyanobacterial toxins in drinking water treatment plants. | toxin-producing cyanobacteria (blue-green algae) are abundant in surface waters used as drinking water resources. the toxicity of one group of these toxins, the microcystins, and their presence in surface waters used for drinking water production has prompted the world health organization (who) to publish a provisional guideline value of 1.0 mug microcystin (mc)-lr/l drinking water. to verify the efficiency of two different water treatment systems with respect to reduction of cyanobacterial toxi ... | 2005 | 15737677 |
| toxic potential of five freshwater phormidium species (cyanoprokaryota). | among the cyanoprokaryota (blue-green algae), the genus phormidium has thus far rarely been studied with respect to toxin production and potentially resulting human and environmental health effects. we here show that five previously unexplored freshwater species of this genus (ph. bijugatum, ph. molle, ph. papyraceum, ph. uncinatum, ph. autumnale) are indeed capable of producing bioactive compounds. phormidium extracts caused weight loss as well as neuro/hepatotoxic symptoms in mice, and in the ... | 2005 | 15804520 |
| toxic cyanobacterial cells containing microcystins induce oxidative stress in exposed tilapia fish (oreochromis sp.) under laboratory conditions. | the effects of microcystins from cyanobacterial cells on various oxidative stress biomarkers in liver, kidney and gill tissues in freshwater tilapia fish (oreochromis sp.) were investigated under laboratory conditions. microcystins are a family of cyclic peptide toxins produced by species of freshwater cyanobacteria (blue-green algae). fish were exposed to the cyanobacterial cells in two ways: mixed with a commercial fish food or crushed into a commercial fish food so that the toxins were releas ... | 2005 | 15820106 |
| macromolecule metabolism and photosynthetic functions in blue-green algae treated with virginiamycin, an inhibitor of protein synthesis. | the m component of virginiamycin inhibited growth of plectonema boryanum under both photoautotrophic and heterotrophic conditions. though the s component of this antibiotic had no apparent activity per se, it enhanced the inhibitory action of its partner. cells incubated with suitable concentrations of either m or m + s stopped growing and lysed. loss of the colony-forming capacity occurred quickly in the presence of m + s and slowly in the presence of m alone. virginiamycin m inhibited protein ... | 1974 | 15828183 |
| production in cultural solution of some amino acids by the atmospheric nitrogen-fixing blue-green algae. | | 1951 | 14904032 |
| fly-ash-induced oxidative stress and tolerance in prosopis juliflora l. grown on different amended substrates. | field experiments were conducted to study the impact of metal accumulation on malondialdehyde (mda), cysteine and non-protein thiol (npsh) contents in the plants of prosopis juliflora grown on the fly ash (fa) amended with soil, blue green algae (bga) biofertilizer, farm yard manure, press mud and rhizobium inoculation. the analysis of data revealed that the level of mda, cysteine and npsh was higher in the roots of the plant than leaves, which was found positively correlated with metal accumula ... | 2005 | 15869202 |
| biosorption of cr3+, cd2+ and cu2+ ions by blue-green algae spirulina sp.: kinetics, equilibrium and the mechanism of the process. | the process of biosorption of heavy metal ions (cr3+, cd2+, cu2+) by blue-green algae spirulina sp. is discussed in this paper. spirulina sp. was found to be a very efficient biosorbent. the aim of the present study was to investigate quantitatively the potential binding sites present at the surface of spirulina sp., using both potentiometric titrations and adsorption isotherms. the kinetic experiments showed that the process equilibrium was reached quickly, in less than 5-10 min. it was found t ... | 2005 | 15698647 |
| cyanobacteria and earthy/musty compounds found in commercial catfish (ictalurus punctatus) ponds in the mississippi delta and mississippi--alabama blackland prairie. | the compounds responsible for earthy and musty "off-flavors" in farm-raised channel catfish (ictalurus punctatus) in the southeastern united states of america are geosmin and 2-methylisoborneol (mib), respectively. these compounds are produced by certain species of cyanobacteria (blue-green algae) that grow in the aquaculture ponds. previous research has focused on the species of cyanobacteria found in catfish ponds in west mississippi (the leading region of catfish production in the usa), while ... | 2005 | 15993924 |
| optimization of anabaenopeptin extraction from cyanobacteria and the effect of methanol on laboratory manipulation. | anabaenopeptins are commonly occurring bioactive peptides of cyanobacterial origin. cyanobacteria (blue-green algae) are known to be capable of producing a large number of biologically active peptides, but the widespread occurrence of anabaenopeptins in particular, makes them ideal candidates for investigating the reasons that cyanobacteria produce such a complex spectrum of peptides and the wider implications of their natural function(s). despite the identification of these peptides in cyanobac ... | 2006 | 16099074 |
| fresh water blue green algae from three agro-climatic zones of uttar pradesh, india: distribution pattern with seasonal variation. | the paper deals with 45 species of 21 genera of fresh water blue green algae (bga) from three different agro-climatic zones of uttar pradesh. samples were collected from different habitats varying in physico-chemical properties. out of 45 species, 13 species belonged to order chroococcales, 31 to order nostocales, while only 1 species belonged to order stigonimatales i.e. fischerella mucicola. the physico-chemical parameters like ph, temperature, dissolved oxygen, electrical conductivity, nitrat ... | 2005 | 16114457 |
| potential developmental toxicity of anatoxin-a, a cyanobacterial toxin. | some 2000 species of cyanobacteria (blue-green algae) occur globally in aquatic habitats. they are able to survive under a wide range of environmental conditions and some produce potent toxins. toxin production is correlated with periods of rapid growth (blooms) and 25%-70% of blooms may be toxic. anatoxin-a is an alkaloid neurotoxin that acts as a potent neuro-muscular blocking agent at the nicotinic receptor. acute toxicity, following consumption of contaminated water, is characterized by rapi ... | 2005 | 16127666 |
| comparative effects of the blue green algae nodularia spumigena and a lysed extract on detoxification and antioxidant enzymes in the green lipped mussel (perna viridis). | nodularia spumigena periodically proliferates to cause toxic algal blooms with some aquatic animals enduring and consuming high densities of the blue green algae or toxic lysis. n. spumigena contains toxic compounds such as nodularin and lipopolysaccharides. this current work investigates physiological effects of exposure from bloom conditions of n. spumigena cells and a post-bloom lysis. biochemical and antioxidative biomarkers were comparatively studied over an acute 3-day exposure. in general ... | 2005 | 16291202 |
| bioactive compounds from cyanobacteria and microalgae: an overview. | cyanobacteria (blue-green algae) are photosynthetic prokaryotes used as food by humans. they have also been recognized as an excellent source of vitamins and proteins and as such are found in health food stores throughout the world. they are also reported to be a source of fine chemicals, renewable fuel and bioactive compounds. this potential is being realized as data from research in the areas of the physiology and chemistry of these organisms are gathered and the knowledge of cyanobacterial ge ... | 2005 | 16294828 |
| cyanobacterial toxins--occurrence, biosynthesis and impact on human affairs. | mass developments of cyanobacteria ("blue-green algae") in lakes and brackish waters have repeatedly led to serious concerns due to their frequent association with toxins. among these are the widespread hepatotoxins microcystin (mc) and nodularin (nod). here, we give an overview about the ecostrategies of the diverse toxin-producing species and about the genes and enzymes that are involved in the biosynthesis of the cyclic peptides. we further summarize current knowledge about toxicological mech ... | 2006 | 16304634 |
| removal of microcystins by phototrophic biofilms. a microcosm study. | microcystins (mcs) are a family of natural toxins produced by cyanobacteria (blue-green algae). as a result of eutrophication, massive cyanobacterial blooms occur more frequently and mcs represent important contaminants of freshwater ecosystems. bacterial biodegradation is considered a main mechanism for mc breakdown in environmental conditions. while existing studies were mostly focused on mc biodegradation by planktonic bacteria, our experiments examined the fate and kinetics of mc degradation ... | 2005 | 16305143 |
| nitrogen fixation (acetylene reduction) by epiphytes of freshwater macrophytes. | the involvement of epiphytic microorganisms in nitrogen fixation was investigated in a shallow freshwater pond near ithaca, n.y. the acetylene reduction technique was used to follow diel and seasonal cycles of nitrogen fixation by epiphytes of myriophyllum spicatum. acetylene-reducing activity was maximal between noon and 6 p.m., but substantial levels of activity relative to daytime rates continued through the night. experiments with the seasonal course of activity showed a gradual decline duri ... | 1978 | 16345301 |
| effect of temperature on blue-green algae (cyanobacteria) in lake mendota. | the temperature optimum for photosynthesis of natural populations of blue-green algae (cyanobacteria) from lake mendota was determined during the period of june to november 1976. in the spring, when temperatures ranged from 0 to 20 degrees c, there were insignificant amounts of blue-green algae in the lake (less than 1% of the biomass). during the summer and fall, when the dominant phytoplankton was blue-green algae, the optimum temperature for photosynthesis was usually between 20 and 30 degree ... | 1978 | 16345318 |
| effects of no. 2 fuel oil, nigerian crude oil, and used crankcase oil on attached algal communities: acute and chronic toxicity of water-soluble constituents. | water extracts of a no. 2 fuel oil, a nigerian crude oil, and used crankcase oil were examined for their effects on algal communities in experiments lasting several weeks conducted under near-natural conditions. no. 2 fuel oil extracts depressed algal biomass (chlorophyll a) and resulted in blue-green algal (cyanobacterial) dominance and decreased diatom occurrence. changes in concentrations of chlorophyll c, which was specific for diatoms in this work, and phycocyanin, which was specific for bl ... | 1978 | 16345329 |
| nitrogen fixation by thermophilic blue-green algae (cyanobacteria): temperature characteristics and potential use in biophotolysis. | thermophilic, nitrogen-fixing, blue-green algae (cyanobacteria) were investigated for use in biophotolysis. three strains of mastigocladus laminosus were tested and were found to be equally effective in biophotolysis as judged by nitrogenase activity. the alga, m. laminosus nz-86-m, which was chosen for further study, grew well in the temperature range from 35 to 50 degrees c, with optimum growth at 45 degrees c, at which temperature acetylene reduction activity was also greatest. the maximum to ... | 1979 | 16345353 |
| nitrogen-fixing (acetylene redution) activity and population of aerobic heterotrophic nitrogen-fixing bacteria associated with wetland rice. | nitrogen-fixing activity associated with different wetland rice varieties was measured at various growth stages by an in situ acetylene reduction method after the activities of blue-green algae (cyanobacteria) in the flood water and on the lower portion of the rice stem were eliminated. nitrogen-fixing activities associated with rice varieties differed with plant growth stages. the activities increased with plant age, and the maximum was about at heading stage. the nitrogen fixed during the whol ... | 1979 | 16345379 |
| decomposition of blue-green algal (cyanobacterial) blooms in lake mendota, wisconsin. | decomposition of natural populations of lake mendota phytoplankton dominated by blue-green algae (cyanobacteria) was monitored by using oxygen uptake and disappearance of chlorophyll, algal volume (fluorescence microscopy), particulate protein, particulate organic carbon, and photosynthetic ability (co(2) up-take). in some experiments, decomposition of c-labeled axenic cultures of anabaena sp. was also measured. in addition to decomposition, mineralization of inorganic nitrogen and phosphorus we ... | 1979 | 16345380 |
| effect of ultraviolet-b (280 to 320 nm) radiation on blue-green algae (cyanobacteria), possible biological indicators of stratospheric ozone depletion. | the effect of ultraviolet-b (280 to 320 nm) irradiation on physiological activities of anabaena flos-aquae and the water fern azolla caroliniana has been studied under conditions where lethal effects of irradiation are absent. nitrogenase activity, measured as acetylene reduction, specifically declined during irradiation with low levels of ultraviolet-b, whereas other physiological activities were unaffected. these findings indicate that measurement of acetylene reduction by cyanobacteria may se ... | 1979 | 16345396 |
| lytic organisms and photooxidative effects: influence on blue-green algae (cyanobacteria) in lake mendota, wisconsin. | the effects of exposure to high light intensities on blue-green algal (cyanobacterial) populations were examined in lake mendota, wis. the algal populations were shown to be susceptible to inhibition of photosynthetic activity and pigment bleaching as a result of exposure. these effects generally influence only a small percentage of the lake population and thus are probably not important in causing major declines in chlorophyll a. lytic organisms were shown to increase in numbers in the lake in ... | 1979 | 16345436 |
| effect of interactions among algae on nitrogen fixation by blue-green algae (cyanobacteria) in flooded soils. | nitrogen fixation (c(2)h(2) reduction) by algae in flooded soil was limited by interactions within the algal community. nitrogen fixation by either indigenous algae or tolypothrix tenuis was reduced severalfold by a dense suspension of the green alga nephrocytium sp. similarly, interactions between the nitrogen-fixing alga (cyanobacterium) aulosira 68 and natural densities of indigenous algae limited nitrogen-fixing activity in one of two soils examined. this was demonstrated by developing a var ... | 1979 | 16345463 |
| nitrogen fixation by photosynthetic bacteria in lowland rice culture. | propanil (3',4'-dichloropropionanilide) was a potent inhibitor of the nitrogenase activity of blue-green algae (cyanobacteria) in flooded soil, but the herbicide at comparable concentrations was not toxic to rice, protozoa, and nitrogen-fixing bacteria. ethanol-amended flooded soils treated with propanil exhibited higher rates of nitrogenase activity than those not treated with the herbicide. the enhanced nitrogenase activity in propanil-treated soils was associated with a rise in the population ... | 1980 | 16345507 |
| effect of rice plants on nitrogenase activity of flooded soils. | in samples of flooded soil containing blue-green algae (cyanobacteria), the presence of rice plants did not influence the nitrogenase activity of the algae. nitrogenase activity of heterotrophic bacteria was enhanced by the presence of rice plants, but this activity was not affected by changes in plant density. the rate of nitrogen fixation in the rhizosphere, however, varied significantly among the 16 rice varieties tested. a simple method was devised to test the nitrogen-fixing activity in the ... | 1980 | 16345630 |
| microplate technique for determining accumulation of metals by algae. | a microplate technique was developed to determine the conditions under which pure cultures of algae removed heavy metals from aqueous solutions. variables investigated included algal species and strain, culture age (11 and 44 days), metal (mercury, lead, cadmium, and zinc), ph, effects of different buffer solutions, and time of exposure. plastic, u-bottomed microtiter plates were used in conjunction with heavy metal radionuclides to determine concentration factors for metal-alga combinations. th ... | 1981 | 16345764 |
| pseudomonas aeruginosa chemotaxis associated with blooms of n(2)-fixing blue-green algae (cyanobacteria). | pseudomonas aeruginosa (schroeter) migula, a numerically significant bacterium found during n(2)-fixing blooms of the blue-green algae (cyanobacteria) anabaena sp. in the chowan river, north carolina, was chemotactically attracted to amino acids when tested in a radioassay. the bacterium was labeled with p(i), and the disintegrations per minute determined by liquid scintillation counting were proportional to the number of cells accumulating in microcapillaries containing amino acids. positive ch ... | 1983 | 16346204 |
| estimating bacterioplankton production by measuring [h]thymidine incorporation in a eutrophic swedish lake. | bacterioplankton abundance, [h]thymidine incorporation, co(2) uptake in the dark, and fractionated primary production were measured on several occasions between june and august 1982 in eutrophic lake norrviken, sweden. bacterioplankton abundance and carbon biomass ranged from 0.5 x 10 to 2.4 x 10 cells liter and 7 to 47 mug of c liter, respectively. the average bacterial cell volume was 0.185 mum. [h]thymidine incorporation into cold-trichloroacetic acid-insoluble material ranged from 12 x 10 to ... | 1983 | 16346304 |
| enumeration, isolation, and characterization of n(2)-fixing bacteria from seawater. | marine pelagic n(2)-fixing bacteria have not, in general, been identified or quantified, since low or negligible rates of n(2) fixation have been recorded for seawater when blue-green algae (cyanobacteria) are absent. in the study reported here, marine n(2)-fixing bacteria were found in all samples of seawater collected and were analyzed by using a most-probable-number (mpn) method. two different media were used which allowed growth of microaerophiles, as well as that of aerobes and facultative ... | 1985 | 16346855 |
| coupling of solar energy to hydrogen peroxide production in the cyanobacterium anacystis nidulans. | hydrogen peroxide production by blue-green algae (cyanobacteria) under photoautotrophic conditions is of great interest as a model system for the bioconversion of solar energy. our experimental system was based on the photosynthetic reduction of molecular oxygen with electrons from water by anacystis nidulans 1402-1 as the biophotocatalyst and methyl viologen as a redox intermediate. it has been demonstrated that the metabolic conditions of the algae in their different growth stages strongly inf ... | 1989 | 16347855 |
| deoxyribonucleic acid of the blue-green algae (cyanophyta). | | 1967 | 16350207 |
| thermophilic blue-green algae and the thermal environment. | [this corrects the article on p. 485 in vol. 33.]. | 1970 | 16350215 |
| protective effect of spirulina against doxorubicin-induced cardiotoxicity. | the generation of reactive oxygen species and mitochondrial dysfunction has been implicated in doxorubicin (dox)-induced cardiotoxicity. the aim of the present study was to determine whether spirulina, a blue-green algae, could serve as a cardioprotective agent during dox treatment in a mouse model. mice were treated with dox (4 mg/kg bw, intraperitoneally), weekly, for 4 weeks. spirulina was administered orally for 3 days twice daily, then for 7 weeks along with the four equal injections of dox ... | 2005 | 16372368 |
| [role of sodium ions and their uptake by cells of cultured blue-green algae, spirulina platensis and spirulina maxima]. | the growth of the blue-green algae spirulina platensis and spirulina maxima, cultured in complete mineral zarouk medium containing na+ or na+-deficient medium, was studied over a period of 24 h. the optical densities of s. platensis and s. maxima cells, determined during the last hour of exposure to sodium deficiency, amounted to 55.6 and 32.6%, respectively, of the optical densities of the same cells grown in complete zarouk medium. moreover, the cultures grown in na+-deficient medium exhibited ... | 2005 | 16400983 |
| a multicenter phase ii study of the cryptophycin analog ly355703 in patients with platinum-resistant ovarian cancer. | ly355703 is a synthetic product structurally related to the cryptophycin family isolated from the blue-green algae, which exerts a potent destabilization of microtubules during mitosis. this study was performed to determine the activity of ly355703 in patients with platinum-resistant advanced ovarian cancer and to characterize its toxicity profile. twenty-six patients were enrolled in this study. resistant disease was defined as a platinum-free interval of <6 months from primary treatment or rec ... | 2006 | 16445613 |
| differential oxidative stress responses to microcystins lr and rr in intraperitoneally exposed tilapia fish (oreochromis sp.). | increasing evidence suggests that oxidative stress may play a significant role in causing microcystin (mcs) toxicity not only in mammals, but also in fish. mcs are a family of cyclic peptide toxins produced by some species of freshwater cyanobacteria (blue-green algae). among the microcystins, mc-lr is the most extensively studied. in the present study the differential response of the antioxidant enzymes superoxide dismutase (sod), catalase (cat), glutathione peroxidase (gpx) and glutathione red ... | 2006 | 16455146 |
| the acute and chronic toxicity of hexadecyl and heptadecyl sulfate to aquatic organisms. | hsas (high-solubility alkyl sulfate) is a new anionic surfactant composed predominantly of methyl and ethyl branched hexadecyl and heptadecyl sulfate. effects of hsas on a wide range of fish, algae, and invertebrates were investigated in conventional laboratory toxicity tests as well as in exposures conducted as part of an experimental stream model ecosystem study. for invertebrates and fish, c(16.7)hsas (average alkyl chain length 16.7) acute lc(50) values ranged from 0.23 (channel catfish) to ... | 2006 | 16465560 |
| improved method for the determination of anatoxin-a and two of its metabolites in blue-green algae using liquid chromatography with fluorescence detection. | anatoxin-a, a neurotoxin produced by blue-green algae (bga) species, can cause death to exposed organisms. in north america, bga are harvested and sold as food supplements, some of which contain elevated levels of other algal toxins, such as microcystins. concern that elevated levels of anatoxin-a also may be present in bga food supplements has led to the development of a simple method to determine the presence of anatoxin-a in bga. some researchers have successfully analyzed this compound using ... | 2005 | 16526457 |
| the bioenergetic role of dioxygen and the terminal oxidase(s) in cyanobacteria. | owing to the release of 13 largely or totally sequenced cyanobacterial genomes (see and ), it is now possible to critically assess and compare the most neglected aspect of cyanobacterial physiology, i.e., cyanobacterial respiration, also on the grounds of pure molecular biology (gene sequences). while there is little doubt that cyanobacteria (blue-green algae) do form the largest, most diversified and in both evolutionary and ecological respects most significant group of (micro)organisms on our ... | 2005 | 15863101 |
| [hepatotoxicity of the microcystin cyanotoxin]. | at public health, there is increasingly interest on evaluating the possibility of human intoxication by biotoxins from blue-green algae, mainly the hepatotoxins from the microcystin group. microcystin, a monocyclic heptapeptide, is mainly produced by a cyanobacteria called microcistis aeruginosa. it is characterized by a few variable amino acids, from which two of them have an unusual structure and play an important role in the hepatotoxicity of the microcystin. although human illnesses include ... | 2004 | 15586902 |
| occurrence of toxic blue-green algae in the kucukcekmece lagoon (istanbul, turkey). | the concentration of microcystin (mc) in the kucukcekmece lagoon, istanbul, turkey, and the physicochemical and biological parameters of water quality were investigated from october 2000 to june 2003. water samples were collected from surface waters at three sites. most bloom samples were dominated by microcystis aeruginosa. the major microcystin variants detected by hplc-pda were microcystin-yr and microcystin-lr. microcystin concentration increased dramatically from early summer to early autum ... | 2005 | 15892069 |
| regulatory system for light-responsive gene expression in photosynthesizing bacteria: cis-elements and trans-acting factors in transcription and post-transcription. | cyanobacteria (blue-green algae) are photosynthesizing organisms that can be used as a model for analyzing light-responsive gene expression. the regulatory system of the light-responsive psba gene with cis-elements and trans-acting factors was studied at both transcriptional and post-transcriptional levels. positive regulation comprises dna curvatures (cit and rib), upstream elements (upe and promoter), and a light-induced sigma factor (sigd) of rna polymerase in transcription. on the other hand ... | 2006 | 16556970 |
| feedback regulation of arginine biosynthesis in blue-green algae and photosynthetic bacteria. | hoare, d. s. (the university of texas, austin), and s. l. hoare. feedback regulation of arginine biosynthesis in blue-green algae and photosynthetic bacteria. j. bacteriol. 92:375-379. 1966.-a number of blue-green algae and photosynthetic bacteria synthesize arginine from glutamate via acetylated intermediates. cell-free extracts of these photosynthetic microorganisms contain an n-acetyl glutamate phosphokinase, which is specifically inhibited by arginine. they also contain a transacetylase whic ... | 1966 | 16562123 |
| oxidation of the cyanobacterial hepatotoxin microcystin-lr by chlorine dioxide: influence of natural organic matter. | cyanobacteria (blue-green algae) are known producers of cytotoxic, hepatotoxic, and neurotoxic compounds with severe acute and chronic effects on vertebrates. successful removal of these toxins in drinking water treatment is therefore of importance for public health. in the present work the oxidation of the cyanobacterial hepatotoxin microcystin-lr (mc-lr) by chlorine dioxide (clo2) was studied at natural microcystin concentrations (10 microg l(-1)) and normal clo2 dosages (1 mg l(-1)) in the ab ... | 2006 | 16568763 |
| effect of spirulina, a blue green algae, on gentamicin-induced oxidative stress and renal dysfunction in rats. | gentamicin (gm), an aminoglycoside, is widely employed in clinical practice for the treatment of serious gram-negative infections. the clinical utility of gm is limited by the frequent incidence of acute renal failure. experimental evidences suggest that oxidative and nitrosative stress play an important role in gm nephrotoxicity. spirulina fusiformis is a blue green algae with potent free radical scavenging properties. the present study was designed to investigate renoprotective potential of s. ... | 2006 | 16573712 |
| causes of color change in blue-green algae. | | 1934 | 16587880 |
| temperature and manganese as determining factors in the presence of diatom or blue-green algal floras in streams. | diatoms are usually the major component of the algal flora in many streams, although green and blue-green algae may be present. these experiments were designed to determine if high temperature or a shift in the chemical composition of the water might bring about a dominance of blue-green algae and/or green algae rather than a dominance of diatoms in the algal flora.the results of these experiments indicate that an average temperature of 34 degrees to 38 degrees c results in a shift of dominance ... | 1969 | 16591790 |
| fossil microorganisms from the approximately 2800 to 2500 million-year-old bulawayan stromatolite: application of ultramicrochemical analyses. | microfossils, probably representing members of precambrian photosynthetic communities of bacteria and blue-green algae, have been found in the approximately 2800-2500 million-year-old bulawayan stromatolites from rhodesia. several populations of coccoid and elongate microfossils have been observed in the dark, carbon-rich stromatolite laminae. some of these elongate forms are morphologically similar to modern bacterial spores. these microfossils were studied in petrographic thin sections and ide ... | 1976 | 16592348 |
| "living electrode" as a long-lived photoconverter for biophotolysis of water. | living blue-green algae (mastigocladus laminosus), immobilized on an sno(2) optically transparent electrode with calcium alginate, functioned as an anodic photoelectrode on continuous illumination for periods of time adequate for use in a conventional electrochemical cell. this "living electrode" shows promise of use as a long-lived photoconverter of solar radiant energy to electric energy and as a suitable replacement for unstable chloroplast systems. | 1980 | 16592817 |
| formation of hybrid phycobilisomes by association of phycobiliproteins from nostoc and fremyella. | formation of phycobilisomes has been accomplished in vitro from isolated phycobiliprotein fractions obtained from the same blue-green alga (intrageneric) and from different blue-green algae (intergeneric). phycobilisomes, which are supra-molecular complexes of phycobiliproteins, serve as major light-harvesting antennae for photosynthesis in blue-green and red algae. intrageneric association into energetically functional phycobilisomes, previously reported to occur with nostoc sp. allophycocyanin ... | 1982 | 16593223 |
| sequence of the gene coding for the beta-subunit of dinitrogenase from the blue-green alga anabaena. | the nitrogen fixation nif k gene of the blue-green alga anabaena, which codes for the beta-subunit of dinitrogenase, has been subjected to sequence analysis. the nif k protein is predicted to be 512 amino acids long, to have a m(r) or 57,583, and to contain six cysteine residues. three of these cysteines are within peptides homologous to fes cluster-binding cysteinyl peptides from ferredoxins and from a high potential iron protein and, thus, may be ligands to which fes clusters bind in dinitroge ... | 1982 | 16593247 |
| cyanobacteria toxins in the salton sea. | the salton sea (ss) is the largest inland body of water in california: surface area 980 km2, volume 7.3 million acre-feet, 58 km long, 14-22 km wide, maximum depth 15 m. located in the southeastern sonoran desert of california, it is 85 m below sea level at its lowest point. it was formed between 1905 and 1907 from heavy river flows of the colorado river. since its formation, it has attracted both people and wildlife, including flocks of migratory birds that have made the salton sea a critical s ... | 2006 | 16623944 |
| lc/esi/ms method development for the analysis of hepatotoxic cyclic peptide microcystins in animal tissues. | microcystins (mcysts) are a family of related cyclic heptapeptides produced by several genera and species of blue-green algae (cyanobacteria). mcysts are potent and specific inhibitors of the serine threonine family of protein phosphatases, especially pp1 and pp2a. mcysts inhibit a liver's protein phosphatase by forming a covalent linkage between mcysts' mdha residue and the phosphatase's cysteine residue. due to the covalent linkage, analysis of mcysts in animal tissues has been limited to dete ... | 2006 | 16626770 |