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severe hepatotoxicity caused by the tropical cyanobacterium (blue-green alga) cylindrospermopsis raciborskii (woloszynska) seenaya and subba raju isolated from a domestic water supply reservoir.cylindrospermopsis raciborskii, a tropical blooming species of cyanobacterium (blue-green alga), was isolated from the domestic water supply reservoir on palm island, a continental island off the tropical northeast coast of australia. this species, not previously known to be toxic, was shown to be severely hepatotoxic for mice. the 50% lethal dose at 24 h after injection was found to be 64 +/- 5 mg of freeze-dried culture per kg of mouse. the principal lesion produced was centrilobular to massiv ...19853937492
beyond the barcoo--probable human tropical cyanobacterial poisoning in outback australia.to determine the cause of a disease known variously as "barcoo fever, barcoo spews, barcoo sickness", or simply "the barcoo", once prevalent in outback northern and central australia.19921454012
isolation of cylindrospermopsin from a cyanobacterium umezakia natans and its screening method.in 1987 a cyanobacterium (blue-green alga) umezakia natans was isolated from lake mikata, fukui, japan, as a new member of the family of stigonemataceae. the crude extract of u. natans showed hepatotoxicity to mice, from which a toxic compound was isolated. the toxin was identical in all respects to a recently reported hepatotoxin, cylindrospermopsin, isolated from an australian tropical cyanobacterium cylindrospermopsis raciborskii. because cylindrospermopsin causes fatty liver and central necr ...19949237339
the role of glutathione in the toxicity of a novel cyanobacterial alkaloid cylindrospermopsin in cultured rat hepatocytes.cylindrospermopsin (cy) is a newly isolated alkaloid produced by the cyanobacterium cylindrospermopsis raciborskii, which has been linked to an outbreak of hepatoenteritis in man. the current work examined the suitability of primary cultures of rat hepatocytes as an in vitro model for studying the cytotoxicity of cy. we found that cy (3.3-5.0 microm) caused significant cell death (40-67% of cells by ldh release) in cultured hepatocytes after 18 hr incubation. while investigating possible mechani ...19948198579
inhibition of reduced glutathione synthesis by cyanobacterial alkaloid cylindrospermopsin in cultured rat hepatocytes.cylindrospermopsin (cy) is a naturally occurring alkaloid produced by the cyanobacterium cylindrospermopsis raciborskii, which has been linked to an outbreak of hepatoenteritis in humans. we previously showed that cy is cytotoxic to primary cultures of rat hepatocytes and that cy lowers cell reduced glutathione (gsh) at nontoxic doses. lower cell gsh also potentiates cy-induced cytotoxicity (runnegar et al., biochem biophys res commun 201: 235-241, 1994). our current work examined the mechanism ...19957840799
isolation and toxicity of cylindrospermopsis raciborskii from an ornamental lake.in australia, the tropical/subtropical cyanobacterium cylindrospermopsis raciborskii forms substantial blooms in some drinking water supply reservoirs, rivers and recreational water bodies during the warmer months of the year. this paper describes the isolation, culture and toxicity characterisation of cylindrospermopsis from a water bloom in a small lake in nsw, australia. the cyanobacterium grew as straight trichomes terminating with a characteristic heterocyst. the toxic alkaloid cylindrosper ...19979080590
antibacterial properties of extracts from selected planktonic freshwater cyanobacteria--a comparative study of bacterial bioassays.aqueous and methanol extracts from five selected cyanobacteria were examined for antibacterial properties in six different bacterial bioassays. all five cyanobacteria revealed antibacterial properties. methanol extracts made from tychonema bourrellyi, aphanizomenon flos-aquae and cylindrospermopsis raciborskii showed the most pronounced inhibitory effects, aqueous extracts made from microcystis aeruginosa and t. bourrellyi possessed evident antibacterial properties. the bacterial bioassays were ...19989717298
insect (locusta migratoria migratorioides) test monitoring the toxicity of cyanobacteria.an insect test was developed to investigate the toxicity of cyanobacteria. the african locust, locusta migratoria migratorioides r.f. was used as a test animal instead of mouse. the cyanobacteria tested were aphanizomenon flos-aque, anabaena aphanizomenoides, cylindrospermopsis raciborskii, microcystis aeruginosa. the toxicity of authentic microcystin-lr was also tested. cyanobacteria producing toxins killed the animals when the homogenized cell suspension was injected into the animals. the locu ...19989745918
cyanobacterium cylindrospermopsis raciborskii as a probable cause of death in cattle in northern queensland. 19989791706
the accumulation of cylindrospermopsin from the cyanobacterium cylindrospermopsis raciborskii in tissues of the redclaw crayfish cherax quadricarinatus.redclaw crayfish, cherax quadricarinatus harvested from an aquaculture pond infested by a bloom of the cyanobacterium cylindrospermopsis raciborskii (order: nostocales), were shown to accumulate the toxic alkaloid cylindrospermopsin. pond water samples collected during the bloom contained 589 microg l(-1) of the toxin (93% in the cyanobacterial cells, 7% in the water). crayfish from the pond contained cylindrospermopsin at concentrations of 4.3 microg g freeze dried hepatopancreas tissue and 0.9 ...199910484741
the first evidence of paralytic shellfish toxins in the fresh water cyanobacterium cylindrospermopsis raciborskii, isolated from brazil.the blooms of toxic cyanobacteria (blue-green algae) are causing problems in many countries. during a screening of toxic freshwater cyanobacteria in brazil, three strains isolated from the state of sao paulo were found toxic by the mouse bioassay. they all were identified as cylindrospermopsis raciborskii by a close morphological examination. extracts of cultured cells caused acute death to mice when injected intraperitoneally after developing neurotoxic symptoms which resembled to those caused ...199910414862
degradation of the cyanobacterial toxin cylindrospermopsin, from cylindrospermopsis raciborskii, by chlorination.cylindrospermopsin, a potent cyanobacterial toxin produced by cylindrospermopsis raciborskii and other cyanobacteria, is regularly found in water supplies of queensland, australia. this study focussed on the effectiveness of chlorination as a water treatment procedure for cylindrospermopsin degradation. the results demonstrate that relatively low chlorine doses (<1 mg l(-1)) are sufficient for degradation of cylindrospermopsin, when the dissolved organic carbon content is low. however, if organi ...200010736474
the tolerance of cyanobacterium cylindrospermopsis raciborskii to low-temperature photo-inhibition affected by the induction of polyunsaturated fatty acid synthesis.acyl-lipid desaturation introduces double bonds (unsaturated bonds) at specifically defined positions of fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. desaturation patterns of the glycerolipids of cylindrospermopsis raciborskii, a filamentous cyanobacterium, were determined in cells grown at 35 degrees c and 25 degrees c. the lowering of the growth temperature from 35 degrees c to 25 degrees c resulted in a considerable accumulation of polyunsaturated octade ...200011171248
micronucleus induction and chromosome loss in transformed human white cells indicate clastogenic and aneugenic action of the cyanobacterial toxin, cylindrospermopsin.cylindrospermopsin (cyn) is a potent inhibitor of protein synthesis produced by a number of cyanobacterial species, the most common being cylindrospermopsis raciborskii. cyn contains a uracil moiety attached to a sulphated guanidino moiety, suggesting that it may have carcinogenic activity. this report describes the use of the wil2-ns lymphoblastoid cell-line in the well-validated cytokinesis-block micronucleus (cbmn) assay to test this hypothesis. centromeres (cens) were identified in micronucl ...200011113708
biosynthesis of cylindrospermopsin.studies on the biosynthesis of cylindrospermopsin (1), a potent hepatotoxin associated with the cyanobacterium cylindrospermopsis raciborskii, indicate that 1 is an acetogenin with guanidinoacetic acid serving as the starter unit of the polyketide chain. feeding experiments show that c14 and c15 of 1 are derived from c1 and c2 of glycine, respectively, and c4 through c13 arise from five contiguous acetate units attached head to tail. the methyl carbon on c13 originates from the c(1) pool. the st ...200010813909
molecular characterization of the toxic cyanobacterium cylindrospermopsis raciborskii and design of a species-specific pcr.cylindrospermopsis raciborskii is a toxic-bloom-forming cyanobacterium that is commonly found in tropical to subtropical climatic regions worldwide, but it is also recognized as a common component of cyanobacterial communities in temperate climates. genetic profiles of c. raciborskii were examined in 19 cultured isolates originating from geographically diverse regions of australia and represented by two distinct morphotypes. a 609-bp region of rpoc1, a dna-dependent rna polymerase gene, was ampl ...200010618244
induction of polyunsaturated fatty-acid synthesis enhances tolerance of a cyanobacterium, cylindrospermopsis raciborskii, to low-temperature photoinhibition.acyl-lipid desaturation introduces double bonds (unsaturated bonds) at specifically defined positions of fatty acids that are esterified to the glycerol backbone of membrane glycerolipids. desaturation pattern of the glycerolipids of cylindrospermopsis raciborskii (c. raciborskii), a filamentous cyanobacterial strain, was determined in cells grown at 35 degrees c and 25 degrees c. the lowering of the growth temperature from 35 degrees c to 25 degrees c resulted in a considerable accumulation of ...200011355635
preliminary evidence for in vivo tumour initiation by oral administration of extracts of the blue-green alga cylindrospermopsis raciborskii containing the toxin cylindrospermopsin.new reports indicate that the toxic alkaloid cylindrospermopsin occurs in cyanobacteria in israel, florida, south america, and australia in drinking water sources. this toxin is now recognised as a potential threat to human health. furthermore, we have recently demonstrated the mutagenicity of cylindrospermopsin in vitro in a human lymphoblastoid cell-line. therefore it is essential to determine whether cylindrospermopsin is also carcinogenic in vivo. in this preliminary study, 53 mice were trea ...200111339720
varied diazotrophies, morphologies, and toxicities of genetically similar isolates of cylindrospermopsis raciborskii (nostocales, cyanophyceae) from northern australia.the potentially toxic freshwater cyanobacterium cylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. this paper investigates the effects of different nitrogen sources (no3-, nh4+, and omission of a fixed form of nitrogen) on the growth rates, morphologies, and cylindrospermopsin (cyl) concentrations (expressed as a percentage of the freeze-dried weight) of seven c. raciborskii isolates obtained from a range of water bodies in northern ...200111282641
photocatalytic degradation of the cyanotoxin cylindrospermopsin, using titanium dioxide and uv irradiation.cylindrospermopsis raciborskii produces the cyanotoxin cylindrospermopsin, which is commonly found in southeast queensland water reservoirs, and has been responsible for the closure of these reservoirs as a source of drinking water in recent times. thus, alternative more effective treatment methods need to be investigated for the removal of toxins such as cylindrospermopsin. this study examined the effectiveness of two brands of titanium dioxide under uv photolysis for the degradation of cylindr ...200111268845
factors influencing lake recovery from eutrophication--the case of basin 1 of lake balaton.lake balaton is a large, shallow, and calcareous lake that was subject to a rapid eutrophication during the 1970s. management measures taken from the mid-1980s decreased the phosphorus load to the lake from 0.5 to 0.3 g p m-2 yr-1. using long-term load and water quality data, we analyse the response of the formerly hypertrophic basin 1 of the lake by the means of simple empirical models. several factors that are commonly neglected during studies of lake recovery modified the apparent settling ve ...200111228971
isolation and identification of the cyanotoxin cylindrospermopsin and deoxy-cylindrospermopsin from a thailand strain of cylindrospermopsis raciborskii (cyanobacteria).a strain of cylindrospermopsis (cyanobacteria) isolated from a fishpond in thailand was examined for its taxonomy based upon morphology and 16s rrna gene sequence. it was also examined for production of the hepatotoxic cyanotoxin called cylindrospermopsin (cyn) and deoxycylindrospermopsin (deoxy-cyn). the strain (cy-thai) was identified as c. raciborskii (woloszynska) seenaya and subba raju based upon morphological examination which was confirmed by 16s rrna gene sequences and phylogenetic compa ...200111223086
the effects of the ciliate paramecium cf. caudatum ehrenberg on toxin producing cylindrospermopsis isolated from the fitzroy river, australia.the large ciliate paramecium cf. caudatum ehrenberg was found to be a successful grazer of toxin producing cylindrospermopsis in the laboratory. the feeding rate increased with increasing cell concentration to 1367 cell animal hr-1 at 4.1 x 10(5) cells ml-1 but declined slightly at cell concentrations greater than this. preliminary studies on the effects of this grazing on toxin concentrations in cultures of both straight and coiled forms of cylindrospermopsis resulted in the production of diffe ...200111769246
phenotypical variation in a toxic strain of the phytoplankter, cylindrospermopsis raciborskii (nostocales, cyanophyceae) during batch culture.a nonaxenic strain of cylindrospermopsis raciborskii woloszynska (awt 205) was grown in batch culture, with and without nitrate as the primary n source. rapid log-phase growth with nitrate was 1.0 doubling/day versus 0.3 doubling/day without nitrate. cylindrospermopsin (cyn) production was measured by hplc. the rate of intracellular cyn production matched cell division rate for both the diazotrophies at cell densities less than 10(7) cell/ml. at cell density > 10(7) cell/ml, additional resource ...200111769242
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 ...200112805693
cell-free protein synthesis inhibition assay for the cyanobacterial toxin cylindrospermopsin.the cyanobacterial toxin cylindrospermopsin (cyn) is known to be a potent inhibitor of protein synthesis. this paper describes the use of a rabbit reticulocyte lysate translation system as a protein synthesis inhibition assay for cyn. a dose response curve for protein synthesis inhibition by cyn was constructed and was modeled to a sigmoidal dose response curve with variable slope (r2 = 0.98). in this assay, cyn has an ic50 of 120 nm [95% confidence limits (cl) = 111-130 nm] with a detection lim ...200111594027
identification of genes implicated in toxin production in the cyanobacterium cylindrospermopsis raciborskii.cylindrospermopsis raciborskii is a bloom-forming cyanobacterium found in both tropical and temperate climates which produces cylindrospermopsin, a potent hepatotoxic secondary metabolite. this organism is notorious for its association with a significant human poisoning incident on palm island, australia, which resulted in the hospitalization of 148 people. we have screened 13 c. raciborskii isolates from various regions of australia and shown that both toxic and nontoxic strains exist within th ...200111594028
allergenic (sensitization, skin and eye irritation) effects of freshwater cyanobacteria--experimental evidence.many studies have been published on the human health effects of cyanobacterial toxicity. as a public health concern, we have to mention that the development of contact dermatitis, asthmalike symptoms, and symptoms resembling hay fever during bathing in cyanobacterial blooms have been also described. microcystis aeruginosa, anabaena flos-aquae, aphanizomenon flos-aquae, and cylindrospermopsis raciborskii are the most common species found in hungarian freshwaters. a sensitization test on albino gu ...200111769249
extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from cylindrospermopsis raciborskii.the hepatotoxin cylindrospermopsin (cyn) has been isolated from the cyanobacterium cylindrospermopsis raciborskii (c. raci.). efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. it is usually extracted from lyophilized cells collected from a laboratory culture. our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. we have therefore investigated the u ...200111594025
genotoxicity investigation of a cyanobacterial toxin, cylindrospermopsin.cylindrospermopsin (cyn), a potent cyanobacterial hepatotoxin produced by cylindrospermopsis raciborskii and other cyanobacteria, is regularly found in water supplies in many parts of the world, and has been associated with the intoxication of humans and livestock. in this study, balb/c mice were injected via the intraperitoneal (ip) route with a single dose of 0.2 mg/kg cyn. animals were sacrificed at 6, 12, 24, 48 and 72 h. dna was isolated from the mouse livers, and examined for strand breaka ...200212368121
effects of organic solvents on the high performance liquid chromatographic analysis of the cyanobacterial toxin cylindrospermopsin and its recovery from environmental eutrophic waters by solid phase extraction.the effect of organic solvents on the high performance liquid chromatography (hplc) analysis of cylindrospermopsin using photodiode array detection was examined since organic solvents are commonly used to extract this toxin from cyanobacteria and in the mobile phase compositions used in hplc. increasing concentrations of methanol resulted in an increase in the uv absorbance of purified cylindrospermopsin according to spectrometry, but to a marked decrease during hplc analysis when the concentrat ...200212435497
hplc-pda detection of cylindrospermopsin--opportunities and limits.the cyanobacterial hepatotoxic alkaloid cylindrospermopsin (cyl) is of increased concern to public health due to the spreading of its main producer, cylindrospermopsis raciborskii, around the globe. here we present results of an evaluation of the possibility to analyse environmental samples for their content of cyl based on hplc with photo diode array detection as an alternative to costly lc-ms approaches. a gradient from 0% to 50% aqueous methanol (+0.05% trifluoroacetic acid) in 20 min proved ...200212418670
rdna analyses of planktonic heterocystous cyanobacteria, including members of the genera anabaenopsis and cyanospira.the taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rrna operon, the 16s rrna gene (rrns) and the internal transcribed spacer (its) located between the 16s rrna and 23s rrna genes. the rrns sequences were determined for five strains, including representatives of anabaena flos-aquae, aphanizomenon flos-aquae, nodularia sp. and two alkaliphilic planktonic members of the genera anabaenopsis and ...200211832512
genetic characterization of cylindrospermopsis raciborskii (cyanobacteria) isolates from diverse geographic origins based on nifh and cpcba-igs nucleotide sequence analysis.isolates of the toxic, n(2)-fixing species cylindrospermopsis raciborskii from various geographic locations were analyzed with respect to their genetic diversity based on the nifh and cpcba-igs genes. gene sequences clustered according to their geographic origin, with the nifh sequences separating into european, australian, and american groups and the cpcba-igs sequences separating into american and european or australian groups. pcr primers for both genes were designed to exclusively amplify dn ...200211976136
salinity effects on growth, photosynthetic parameters, and nitrogenase activity in estuarine planktonic cyanobacteria.salinity has been suggested as being a controlling factor for blooms of n2-fixing cyanobacteria in estuaries. we tested the effect of salinity on the growth, n2 fixation, and photosynthetic activities of estuarine and freshwater isolates of heterocystous bloom-forming cyanobacteria. anabaena aphanizomenoides and anabaenopsis sp. were isolated from the neuse river estuary, north carolina, and cylindrospermopsis raciborskii from lakes dora and griffin, central florida. salinity tolerance of these ...200212043002
toxicity of cylindrospermopsin to the brine shrimp artemia salina: comparisons with protein synthesis inhibitors and microcystins.the artemia salina bioassay was successfully applied to the analysis of the hepatotoxic cyanobacterial alkaloid and protein synthesis inhibitor, cylindrospermopsin. a dose-dependent response in mortality was observed for purified cylindrospermopsin and lc(50) values decreased with time from 8.1 to 0.71 microg/ml(-1), between 24 and 72 h, respectively. cylindrospermopsin was slightly less potent than micro cystin-lr, with similar lc(50) values on a gravimetric basis, but was more toxic to a.salin ...200212165313
cyanobacteria-mediated internal eutrophication in shallow lake balaton after load reduction.nutrient loads to large, shallow lake balaton have been reduced by 45-50% since mid-1980s. while a delayed, but still surprisingly fast recovery was observed in the hypertrophic western areas of the lake, eutrophication followed sewage diversion from the mesotrophic northern basins. we assessed factors that could lead to this unusual response. the prime reason of the observed biomass increase might be a trend of increasing mean water temperature during late summers and the concurrent invasion of ...200212188130
environmental context of cylindrospermopsis raciborskii (cyanobacteria) blooms in a shallow pond in france.cylindrospermopsis raciborskii, a potentially toxic blooming cyanobacterium (blue-green alga), responsible for public health problems in australia, was identified in france in 1994 in a shallow pond south of paris. a program monitoring the occurrence of c. raciborskii in this pond was conducted from july 1998 to october 1999. the phytoplankton assemblages were studied, and limnological parameters (water temperature, dissolved oxygen, ph, conductivity, and dissolved inorganic nutrients) were meas ...200212188114
membrane effects of toxins isolated from a cyanobacterium, cylindrospermopsis raciborskii, on identified molluscan neurones.the effect of anatoxin (antx), the crude extract (algtx) and purified fraction (f1) isolated from cyanobacterium c. raciborskii was studied on the neurones of two snail species. antx and algtx exerted excitatory, inhibitory and biphasic effects on the spontaneous activity of identified neurones. both antx and algtx elicited an inward current, which could be decreased by curare or amiloride. on the contrary, f1 had no direct effect on the spontaneous activity; it was not able to induce conductanc ...200211879784
capillary electrophoretic assay and purification of cylindrospermopsin, a cyanobacterial toxin from aphanizomenon ovalisporum, by plant test (blue-green sinapis test).toxic cyanobacteria are known to produce cyanotoxins, toxic secondary metabolites. in recent years the cylindrospermopsin (tricyclic guanidinyl hydroxymethyluracil)-producing organisms aphanizomenon ovalisporum, cylindrospermopsis raciborskii, and umezakia natans have been inhabiting polluted fresh waters. cylindrospermopsin, a potent hepatotoxic cyanotoxin, has been implicated in cases of human poisoning as well. this study describes the isolation and purification of cylindrospermopsin from a. ...200211846381
hepatic xenobiotic metabolism of cylindrospermopsin in vivo in the mouse.cylindrospermopsin (cyn) is a hepatotoxin isolated from the blue-green alga cylindrospermopsis raciborskii. the role of both glutathione (gsh) and the cytochrome p450 enzyme system (p450) in the mechanism of toxicity of cyn has been previously investigated in in vitro systems. we have investigated the role of gsh and p450 in vivo in mice. mice pre-treated with buthionine sulphoximine and diethyl maleate to deplete hepatic gsh prior to dosing with 0.2mg/kg cyn showed a seven-day survival rate of ...200211738241
low-temperature-induced accumulation of xanthophylls and its structural consequences in the photosynthetic membranes of the cyanobacterium cylindrospermopsis raciborskii: an ftir spectroscopic study.the effects of the growth temperature on the lipids and carotenoids of a filamentous cyanobacterium, cylindrospermopsis raciborskii, were studied., the relative amounts of polyunsaturated glycerolipids and myxoxanthophylls in the thylakoid membranes increased markedly when this cyanobacterium was grown at 25 degrees c instead of 35 degrees c. fourier transform infrared spectroscopy was used to analyze the low-temperature-induced structural alterations in the thylakoid membranes. despite the high ...200211842219
multiplex pcr assay for cylindrospermopsis raciborskii and cylindrospermopsin-producing cyanobacteria.water bodies are routinely monitored for the presence of potentially toxic cyanobacteria; however, the methodology for confirming toxicity is currently complex and expensive. here we describe the application of gene-based technology to rapidly identify cylindrospermopsin-producing cyanobacteria, specifically, cylindrospermopsis raciborskii. a multiplex polymerase chain reaction (pcr) test was developed that simultaneously identified polyketide synthase (pks) and peptide synthetase (ps) determina ...200312635100
first report and toxicological assessment of the cyanobacterium cylindrospermopsis raciborskii from portuguese freshwaters.the freshwater cyanobacterium cylindrospermopsis raciborskii has become increasingly prevalent in freshwaters worldwide. this species is a concern from a water quality perspective due to its known ability to produce a potent hepatotoxic alkaloid cylindrospermopsin, which has been implicated in outbreaks of human sickness and cattle mortality. c. raciborskii strains isolated from brazil have also been found to produce the highly toxic paralytic shellfish poisons (psps). this article reports the t ...200312742375
effects of saxitoxin (stx) and veratridine on bacterial na+ -k+ fluxes: a prokaryote-based stx bioassay.saxitoxin (stx) is a potent natural sodium channel blocker and represents a significant health concern worldwide. we describe here the antagonistic effects of stx and veratridine (vtd), an na+ channel activator, on three gram-negative bacteria and their application to an stx bioassay. stx reduced the total cellular levels of both na+ and k+, as measured by flame photometry, whereas vtd increased the cellular concentrations relative to control ion fluxes in the cyanobacterium cylindrospermopsis r ...200314660387
phylogeography of the invasive cyanobacterium cylindrospermopsis raciborskii.cylindrospermopsis raciborskii is a planktonic freshwater cyanobacterium that has become increasingly prevalent in tropical and temperate water bodies world-wide. this species is of concern from a water-quality perspective because of its known ability to produce toxins that can affect the health of humans and other animals. this study investigates genetic variation between strains of c. raciborskii isolated from freshwater rivers and reservoirs in australia, brazil, germany, hungary, portugal an ...200312492883
the palm island mystery disease 20 years on: a review of research on the cyanotoxin cylindrospermopsin.poisoning of humans resulting from consumption of water affected by the toxic cyanobacterium cylindrospermopsis raciborskii was first reported almost 20 years ago from palm island, northern queensland, australia. since that time a great deal has been learned about this organism and cylindrospermopsin (cyn), the toxin it produces. this article reviews the information now available to us. it summarizes aspects of the chemistry of the toxin-now known to be produced by some cyanobacterial species ot ...200312635096
morphological characteristics of cylindrospermopsis raciborskii (wołoszyńska) seenayya et subba raju in laboratory cultures.the freshwater cyanoprokaryote cylindrospermopsis raciborskii has become increasingly prevalent in tropical and temperate water bodies worldwide. the morphological characteristics of this species were investigated under different growth rates in continuous cultures (at steady state) and in batch (phosphorus starved) cultures with different mineral nitrogen forms. the species displays an enormous morphological variability under controlled condition. the occurrence of extreme long twisted filament ...200312705328
toxicological comparison of diverse cylindrospermopsis raciborskii strains: evidence of liver damage caused by a french c raciborskii strain.the freshwater cyanobacterium cylindrospermopsis raciborskii is known to produce toxic effects in several countries. acute and chronic exposures to c. raciborskii in australia have been linked to liver damage (hepatotoxicity) with concomitant effects on the kidneys, adrenal glands, small intestine, lungs, thymus, and heart. the alkaloid cylindrospermopsin, which produces these toxic effects, is thought to be a potent inhibitor of protein synthesis. c. raciborskii strains producing cylindrospermo ...200312740803
cylindrospermopsin occurrence in two german lakes and preliminary assessment of toxicity and toxin production of cylindrospermopsis raciborskii (cyanobacteria) isolates.cylindrospermopsis raciborskii, a freshwater cyanobacterium of tropical origin, is not only increasingly found in (sub) tropical water bodies, but also in temperate regions. since this species may produce potent toxins such as cylindrospermopsin (cyn) and paralytic shellfish poisons, its massive occurrence in water bodies used as drinking water sources or for recreation is of major concern. the proliferation of c. raciborskii in german water bodies has been documented for the past decade. we inv ...200314559084
molecular detection of genes responsible for cyanobacterial toxin production in the genera microcystis, nodularia, and cylindrospermopsis.cyanobacteria are ubiquitous in the freshwater environment. their success as a group in a wide range of aquatic habitats has been attributed to their unique physiological characteristics and their high adaptive ability over a wide range of environmental conditions. they are capable of reaching very high biomass levels, often dominating the other aquatic biota, and under some circumstances can accumulate near the water surface, producing scums. such cyanobacterial "blooms" are of particular conce ...200415156033
evidence for differences in the metabolism of saxitoxin and c1+2 toxins in the freshwater cyanobacterium cylindrospermopsis raciborskii t3.the activity of paralytic shellfish poisoning (psp) toxins biosynthetic enzymes was assayed in the cyanobacterium cylindrospermopsis raciborskii t3 after inhibiting protein synthesis with chloramphenicol (cam). the production of c1+2 and saxitoxin (stx) was sensitive to cam with stx levels decreasing by 70% after 24-h exposure to the antibiotic. psp toxin production was strongly promoted by arginine supplementation, with a maximum 476% increase in intracellular stx concentrations after 24-h expo ...200415342114
first report of cyanobacterium cylindrospermopsis raciborskii from algerian freshwaters.this study investigated the first report of the cyanobacterium cylindrospermopsis raciborskii in algerian freshwaters. the morphological characteristics of the two morphotypes observed in lake oubeira (algeria) conformed to those of natural populations of c. raciborskii species described in the literature. the two morphotypes produced only straight trichomes. during the study (february 2000-september 2001), this species occurred as a codominant with microcystis spp., and a peak was observed duri ...200415352271
occurrence and elimination of cyanobacterial toxins in two australian drinking water treatment plants.in australian freshwaters, anabaena circinalis, microcystis spp. and cylindrospermopsis raciborskii are the dominant toxic cyanobacteria. many of these surface waters are used as drinking water resources. therefore, the national health and medical research council of australia set a guideline for mc-lr toxicity equivalents of 1.3 microg/l drinking water. however, due to lack of adequate data, no guideline values for paralytic shellfish poisons (psps) (e.g. saxitoxins) or cylindrospermopsin (cyn) ...200415109885
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.200415707167
interactions between intracellular na+ levels and saxitoxin production in cylindrospermopsis raciborskii t3.saxitoxin (stx) is the most potent representative among the paralytic shellfish poisoning (psp) toxins, which are highly selective na(+) channel-blocking alkaloids. this study investigated, in cultures of the cyanobacterium cylindrospermopsis raciborskii t3, the effects of ph, salt, amiloride and lidocaine hydrochloride on total cellular levels of na(+) and k(+) ions and stx accumulation. both na(+) levels and intracellular stx concentrations increased exponentially in response to rising alkalin ...200414766924
analysis of cyanobacterial toxins by hydrophilic interaction liquid chromatography-mass spectrometry.the combination of hydrophilic interaction liquid chromatography with electrospray mass spectrometry (hilic-ms) has been investigated as a tool for the analysis of assorted toxins produced by cyanobacteria. toxins examined included saxitoxin and its various analogues (1-18), anatoxin-a (atx-a, 19), cylindrospermopsin (cyn, 20), deoxycylindrospermopsin (docyn, 21), and microcystins-lr (22) and -rr (23). the saxitoxins could be unequivocally detected in one isocratic analysis using a tsk gel amide ...200414969289
[phytoplankton community in a recreational fishing lake, brazil].the assessment of water quality and phytoplankton community in recreational environments allows to setting management programs aiming at preventing potential harm to human health. the purpose of the present study was to describe phytoplankton seasonal changes in a freshwater system and their relation to water quality.200415499439
development of a universal microarray based on the ligation detection reaction and 16s rrna gene polymorphism to target diversity of cyanobacteria.the cyanobacteria are photosynthetic prokaryotes of significant ecological and biotechnological interest, since they strongly contribute to primary production and are a rich source of bioactive compounds. in eutrophic fresh and brackish waters, their mass occurrences (water blooms) are often toxic and constitute a high potential risk for human health. therefore, rapid and reliable identification of cyanobacterial species in complex environmental samples is important. here we describe the develop ...200415574913
the effect of temperature on growth and production of paralytic shellfish poisoning toxins by the cyanobacterium cylindrospermopsis raciborskii c10.cylindrospermopsis raciborskii is a cyanobacterium which produces either cylindrospermopsine or paralytic shellfish poisoning (psp) toxins. we studied the effect of temperature on growth and production of psp toxins by c. raciborskii c10, isolated from a freshwater reservoir in brazil. we analyzed the extracellular and intracellular content of psp toxins at two different temperatures: 19 and 25 degrees c. c. raciborskii c10 produces stx, gtx2, and gtx3 at both temperatures. dcstx was also detect ...200415450922
accumulation and depuration of the cyanobacterial toxin cylindrospermopsin in the freshwater mussel anodonta cygnea.cylindrospermopsin (cyn) is a toxic alkaloid produced by several genera of freshwater cyanobacteria. this compound has been implicated in outbreaks of human sickness and the death of domestic and wild animals. given that several of the cyanobacterial genera known to produce cyn are common components of the phytoplankton of freshwaters including aquaculture facilities, we studied the accumulation of cyn in the freshwater mussel (swan mussel) anodonta cygnea. anodonta were exposed to cyn-producing ...200415019478
filamentous cyanobacteria, temperature and daphnia growth: the role of fluid mechanics.viscosity increases significantly with a fall in water temperature, thus temperature change affects not only the metabolic rates of aquatic suspension feeders, but also the physical properties of the surrounding fluid. this mechanistic effect of water temperature change on growth was separated from the effect of metabolism by using culture media with modified viscosity, while the temperature was kept constant. the effect of water viscosity on growth rate and feeding of four daphnia species (d. m ...200415375688
toxicity of the cyanobacterium cylindrospermopsis raciborskii to daphnia magna.the effect of two strains of cylindrospermopsis raciborskii on the survivorship, somatic growth, and detoxification processes of juvenile daphnia magna were investigated. both strains of c. raciborskii (and also ankistrodesmus falcatus, used as the control) were given to newborn d. magna at equivalent biovolumes. the survival curves for d. magna subjected to the two c. raciborskii treatments differed from those of the starved and fed treatments. after 48 h of exposure, the percentage of d. magna ...200415352261
effects of algicide (copper sulfate) application on short-term fluctuations of phytoplankton in lake paranoá, central brazil.short-term fluctuations and structure of phytoplankton were examined for two months in the dry season (august-september/1997) in a eutrophic reservoir of central brazil. algicide treatment for the control of microcystis aeruginosa bloom influenced the short-term variation pattern of the phytoplankton community. algicide treatment was effective in controlling m. aeruginosa bloom, but it also influenced the cylindrospermopsis raciborskii population. these species retained low densities, showing sm ...200415744422
morphology, genetic diversity, temperature tolerance and toxicity of cylindrospermopsis raciborskii (nostocales, cyanobacteria) strains from thailand and japan.cylindrospermopsis raciborskii is a planktonic, nostocalean cyanobacterium, which produces an alkaloid heptatoxin, cylindrospermopsin. we performed morphological observations, 16s rdna sequence analysis, pcr fingerprint analysis of short tandemly repeated repetitive (strr) sequences, temperature tolerances and toxin analysis to characterize 24 strains of this toxic cyanobacterium isolated from thailand and japan. all strains shared common morphological traits characteristic of c. raciborskii and ...200419712304
genetic diversity of cylindrospermopsis strains (cyanobacteria) isolated from four continents.the genetic diversity of cylindrospermopsis strains (cyanobacteria) was examined using mainly the 16s-23s internally transcribed spacer (its1) sequences. strains were grouped in three clusters: (i) america, (ii) europe, and (iii) africa and australia. these results suggested a recent spread of cylindrospermopsis across the american and european continents from restricted warm refuge areas instead of exchanges between continents. on the other hand, they also suggested a recent colonization of aus ...200515691973
a new simply and effective fractionation method for cylindrospermopsin analyses.a new simply and effective fractionation method for cylindrospermopsin (cyn) analyses was developed. the extract from cells of cylindrospermopsis raciborskii was resuspended with 0.1 m carbonate buffer at ph 10.5, and pass through the double-cartridges column which was consisted of a styrene polymer cartridge and an anion exchange cartridge. cyn and deoxy-cyn were adsorbed with the anion exchange cartridge. after separation of the anion exchange cartridge, adsorbed compounds were eluted from the ...200515922389
analysis of cyanobacterial-derived saxitoxins using high-performance ion exchange chromatography with chemical oxidation/fluorescence detection.a single run hplc method utilizing ion exchange as the separation mode with a novel mobile phase system coupled to chemical postcolumn oxidation and fluorescence detection has been developed and demonstrated to be applicable to the quantitative analysis of paralytic shellfish poisons (psps) produced by australian cyanobacteria (anabaena circinalis) and other cyanobacteria. both the cyanobacterial matrix and natural water constituents did not significantly affect the performance of this method. t ...200516302175
effects of cyanobacterium fischerella ambigua isolates and cell free culture media on zebrafish (danio rerio) embryo development.the toxic effects of several species of fresh water cyanobacteria, notably microcystis species and associated toxins, the microcystins, anabaena species (anatoxin), nodularia sp. (nodularin), and cylindrospermopsis raciborskii (cylindrospermopsin), are well known. little, however, is known about the effects of secondary metabolites other than alkaloids. early life stage tests with zebrafish (danio rerio) were used to detect bioactive properties of compounds released by healthy cyanobacteria (fis ...200616554083
primary irritant and delayed-contact hypersensitivity reactions to the freshwater cyanobacterium cylindrospermopsis raciborskii and its associated toxin cylindrospermopsin.freshwater cyanobacteria are common inhabitants of recreational waterbodies throughout the world; some cyanobacteria can dominate the phytoplankton and form blooms, many of which are toxic. numerous reports in the literature describe pruritic skin rashes after recreational or occupational exposure to cyanobacteria, but there has been little research conducted on the cutaneous effects of cyanobacteria. using the mouse ear swelling test (mest), we sought to determine whether three toxin-producing ...200616573840
comparative gene expression of psp-toxin producing and non-toxic anabaena circinalis strains.blooms of the freshwater cyanobacterium anabaena circinalis are recognised as an important health risk worldwide due to the production of a range of toxins such as saxitoxin (stx) and its derivatives, also known as paralytic shellfish poisoning (psp) toxins. in this study the transcriptional profile of psp toxin-producing and non-toxic strains of a. circinalis was investigated by means of a dna microarray approach. additionally, gene expression was studied after exposure of toxic a. circinalis c ...200616650472
plankton food web responses to experimental nutrient additions in a subtropical lake.during two controlled enclosure experiments using water from a subtropical lake, the plankton food web displayed a highly variable response to combined addition of nitrogen and phosphorus. in july, the nutrients stimulated growth of cylindrospermopsis raciborskii, and the biomass of macrozooplankton and microbial food web components did not increase. in october, the same addition of nutrients stimulated growth of small edible lyngbya spp., and there were coincident increases in biomass of macroz ...200616862351
selection on protein-coding genes of natural cyanobacterial populations.we examined the distribution of synonymous and non-synonymous changes in 12 protein-coding genes of natural populations of cyanobacteria to infer changes in gene functionality. by comparing mutation distributions within and across species using the mcdonald-kreitman test, we found data sets to contain evidence for purifying selection (hetr of trichodesmium, nifh of cylindrospermopsis raceborskii and rpoc1 of anabaena lemmermannii) and positive selection (kaic of microcoleus chthonoplastes and rb ...200616913914
metabolites produced by cyanobacteria belonging to several species of the family nostocaceae.this paper provides a comprehensive overview of metabolites, including lipids and lipid-like compounds, nitrogen metabolites, oligopeptides and amino acid derivatives, produced by cyanobacteria of the genera anabaenopsis, aphanizomenon, aulosira, cylindrospermopsis, cylindrospermum, nodularia, and richelia of the family nostocaceae.200617004647
influence of intracellular toxin concentrations on cylindrospermopsin bioaccumulation in a freshwater gastropod (melanoides tuberculata).scant information is available regarding the bioaccumulation of cylindrospermopsin (cyn) in aquatic organisms, particularly in invertebrates. this study examined toxin bioconcentration and bioaccumulation in the aquatic snail, melanoides tuberculata, following exposure to freeze-thawed whole cell extracts and a live cylindrospermopsis raciborskii culture containing cyn. both bioconcentration and bioaccumulation were evident, but exposure to toxin in the freeze-thawed solutions resulted in minor ...200616564064
occurrence of toxin-producing cyanobacteria blooms in a brazilian semiarid reservoir.we report the occurrence of cyanobacterial blooms and the presence of cyanotoxins in water samples from the armando ribeiro gonçalves reservoir (06 degrees 08 s and 37 degrees 07 w), located in the state of rio grande do norte, in the semiarid region of northeastern brazil. the cyanobacterial species were identified and quantified during the rainy and dry seasons in the year 2000. cyanotoxins such as microcystins, saxitoxins and cylindrospermopsins were analyzed and quantified using hplc and eli ...200616710515
cyanobacterial (blue-green algal) toxins in water supplies: cylindrospermopsins.the toxic alkaloid cylindrospermopsin is produced by a range of cyanobacterial species worldwide. it was first identified in the species cylindrospermopsis raciborskii from tropical waters, and has since been isolated from four other genera in locations ranging from israel to japan. high concentrations of the organisms and toxin have been identified in reservoirs, natural lakes, and rivers in summer in the usa and in australia. the toxin is a particular problem in drinking water sources as conce ...200616841306
seasonal dynamics and toxicity of cylindrospermopsis raciborskii in lake guiers (senegal, west africa).cylindrospermopsis raciborskii is a toxic bloom-forming cyanobacterium that occurs at tropical and temperate latitudes. despite several reports from africa, no data were previously available about its dynamics or toxic potential there. we therefore carried out a 1-year survey of the dynamics of c. raciborskii in the main water reservoir in senegal, lake guiers. cylindrospermopsis raciborskii never formed a bloom in this lake during the period studied, but was dominant during the dry season. the ...200616907750
effects of cylindrospermopsis raciborskii and aphanizomenon ovalisporum (cyanobacteria) ingestion on daphnia magna midgut and associated diverticula epithelium.this article reports a light and electron microscopy investigation of the effects of cylindrospermopsis raciborskii and aphanizomenon ovalisporum ingestion on midgut and associated digestive diverticula of daphnia magna. additionally, survivorship and growth effects caused by feeding on cyanobacteria were assessed. three cyanobacteria were used in the experiments: cylindrospermopsin (cyn)-producing c. raciborskii, cyn-producing a. ovalisporum and non-cyn-producing c. raciborskii. in order to dis ...200617010452
a rapid microbiotest for the detection of cyanobacterial toxins.cyanobacteria occur widely in lakes, reservoirs, ponds, and slow flowing rivers. many species are known to produce toxins (cyanotoxins), a number of which are of concern for health. cyanotoxins vary in chemical structure and may be found intracellular or released into water. there is not only a wide variation in the toxicity of known cyanotoxins but a substantial number of toxins have to date not been identified chemically. chemical analysis of cyanotoxins is nowadays not used for routine monito ...200717295262
mortality and toxin bioaccumulation in bufo marinus following exposure to cylindrospermopsis raciborskii cell extracts and live cultures.cylindrospermopsis raciborskii is a cyanobacterium responsible for the production of the toxin, cylindrospermopsin (cyn). tadpoles of the cane toad bufo marinus were exposed to freeze-thawed whole cell extracts or live cultures of c. raciborskii containing maximum cyn concentrations of 400 microg l-1 or 232 microg l-1, respectively. exposure to live culture treatment solutions resulted in up to 66% mortality of b. marinus, whereas tadpoles exposed to whole cell extracts containing similar toxin ...200717046128
first report of toxic cylindrospermopsis raciborskii and raphidiopsis mediterranea (cyanoprokaryota) in egyptian fresh waters.cylindrospermopsis raciborskii, a potentially toxic and highly adaptable freshwater cyanobacterium, was believed to have been misidentified in the nile at the end of the 19th century. this study reports the presence of cylindrospermopsis raciborskii and raphidiopsis mediterranea for the first time in egyptian fresh waters since that time. cylindrospermopsis raciborskii appeared in the el-dowyrat fish pond during may 2002, when bottom waters reached, as a result of climatic change, sufficiently h ...200717069621
multiple-organ toxicity resulting from cylindrospermopsin exposure in tadpoles of the cane toad (bufo marinus).histological examinations were made of cane toad (bufo marinus) tadpoles after exposure to freeze-thawed cylindrospermopsis raciborskii whole cell extracts and live c. raciborskii cultures containing sublethal concentrations of the blue-green algal toxin, cylindrospermopsin (cyn). toxin exposure resulted in tissue injuries to multiple organs, with particular severity noted in the liver, intestine, nephric ducts and gill epithelia. the extent of cellular damage was similar across trials exposing ...200718000853
abundance and diversity of phytoplankton in the paraná river (argentina) 220 km downstream of the yacyretá reservoir.patterns in the temporal composition, abundance and diversity of the phytoplankton community of the paraná river prior to and after the initial filling phase of the yacyretá reservoir are analyzed. the study site is located 220 km downstream from the yacyretá reservoir and 30 km downstream from the confluence with the paraguay river. because both rivers remain separate and unmixed at the study site, we compared the possible effects of the impoundment on both river banks (left and right banks) in ...200717505750
studies of the comparative in vitro toxicology of the cyanobacterial metabolite deoxycylindrospermopsin.cyanobacteria are capable of producing metabolites that are in some cases toxic to humans and other animals. of these metabolites, the toxin cylindrospermopsin (cyn) is produced by a number of species of cyanobacteria including cylindrospermopsis raciborskii, and its toxicity has been documented. the cyn analog deoxycylindrospermopsin (deoxycyn) is commonly produced in varying proportions by the cyanobacteria that produce cyn. the toxicological profile of cyn suggests that it is primarily a hepa ...200717763086
climate change affects timing and size of populations of an invasive cyanobacterium in temperate regions.cylindrospermopsis raciborskii, an invasive freshwater cyanobacterium, originated from the tropics but has spread to temperate zones over the last few decades. its northernmost populations in europe occur in north german lakes. how such dramatic changes in its biogeography are possible and how its population dynamics in the newly invaded habitats are regulated are still unexplained. we therefore conducted a long-term (1993-2005) study of two german lakes to elucidate the mechanisms behind c. rac ...200717375336
cylindrospermopsin determination using 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (hepes) as the internal standard.cylindrospermopsin (cyn) was determined by liquid chromatography/electrospray ionization-mass spectrometry (lc/esi-ms) using 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (hepes) as the internal standard. in the selected ion monitoring of lc/esi-ms, m/z 414 for cyn and 237 for hepes were monitored using the negative mode; the retention times of cyn and hepes were 12.41 and 14.21 min, respectively. cyn was determined from peak area ratios of m/z 414/237. by the treatment of an anion exc ...200717386536
correlations between watershed and reservoir characteristics, and algal blooms in subtropical reservoirs.this study examined the correlations between watershed and reservoir characteristics, and water quality parameters related to algal blooms in seven subtropical reservoirs. analysis of the dissimilarity of physico-chemical parameters resulted in separation of the reservoirs into three main groups: four reservoirs with the highest proportion of agriculture and/or urban land use in their watersheds; two reservoirs with a high proportion of forest cover; and one small reservoir with a relatively pri ...200717632205
occurrence of the cyanobacterial toxin cylindrospermopsin in northeast germany.the frequent occurrence of the cyanobacterial toxin cylindrospermopsin (cyn) in the (sub)tropics has been largely associated with cyanobacteria of the order nostocales of tropical origin, in particular cylindrospermopsis raciborskii. c. raciborskii is currently observed to spread northwards into temperate climatic zones. in addition, further cyanobacteria of the order nostocales typically inhabiting water bodies in temperate regions are being identified as cyn-producers. therefore, data on the d ...200717295278
concentrations of particulate and dissolved cylindrospermopsin in 21 aphanizomenon-dominated temperate lakes.the cyanobacterial toxin cylindrospermopsin (cyn) is widely distributed in german lakes, but volumetric data for risk assessment are lacking and it is unclear which cyanobacterial species produce cyn in europe. we therefore analyzed cyn concentration and cyanobacterial composition of 21 german lakes in 2005. cyn was detected in 19 lakes (102 of 115 samples). in total, 45 samples contained particulate cyn only, and 57 contained both dissolved and particulate cyn. the concentrations were 0.002-0.4 ...200717804031
a comparative study of florida strains of cylindrospermopsis and aphanizomenon for cylindrospermopsin production.the toxin cylindrospermopsin (cyn) is produced by a variety of cyanobacterial genera. one of these, cylindrospermopsis raciborskii, is generally assumed to be the source of cyn in lakes and rivers in florida, usa. however, in this study, none of the eight florida isolates of this species tested contained the genetic determinants involved in toxin production nor did they produce cyn. we show for the first time that aphanizomenon ovalisporum isolated from a pond in this state has the genes putativ ...200817928021
rapid preparation of cyanobacterial dna for real-time pcr analysis.to develop a rapid preparation method for real-time pcr analysis of cyanobacteria from cultures or field samples.200818086195
development and field testing of a real-time pcr assay for cylindrospermopsin-producing cyanobacteria.to develop and test a real-time pcr assay to detect and quantify genes specific to cylindrospermopsis sp. and cylindrospermopsin-producing cyanobacteria.200818179541
variable growth responses of water thyme (hydrilla verticillata) to whole-cell extracts of cylindrospermopsis raciborskii.static-renewal ecotoxicity trials monitored growth of hydrilla verticillata in conjunction with exposure to cylindrospermopsis raciborskii whole-cell extracts containing the cyanotoxin cylindrospermopsin (cyn). maximum exposure concentrations were 400 microg l(-1) cyn over 14 days. the responses of hydrilla to the treatments were variable according to the toxin concentrations and lengths of exposure. plant deaths, chlorosis, and necrosis were not recorded from treated plants. however, hydrilla e ...200817762906
toxic cyanobacteria in florida waters.the occurrence of toxic cyanobacterial blooms in florida waters have become more prominent following increased growth, declining groundwater supplies, and identification of impaired surface waters as future drinking water sources. cyanobacterial toxins have been identified in source waters used for drinking water supply and in post-treated drinking water during algal bloom events. algal toxin concentrations in post-treated drinking water have exceeded existing and proposed world health organizat ...200818461767
characterization of the gene cluster responsible for cylindrospermopsin biosynthesis.toxic cyanobacterial blooms cause economic losses and pose significant public health threats on a global scale. characterization of the gene cluster for the biosynthesis of the cyanobacterial toxin cylindrospermopsin (cyr) in cylindrospermopsis raciborskii awt205 is described, and the complete biosynthetic pathway is proposed. the cyr gene cluster spans 43 kb and is comprised of 15 open reading frames containing genes required for the biosynthesis, regulation, and export of the toxin. biosynthes ...200818065631
phytoplankton growth control and risk of cyanobacterial blooms in the lower senegal river delta region.eutrophication, and the resulting proliferation of phytoplankton can affect water quality. although environmental and ecological processes that lead to phytoplankton proliferations in temperate areas have received considerable attention, scientific background regarding this topic in tropical areas, especially west africa, are scarce. in this study, bioassays in batch cultures were carried out in order to identify factors that may be stimulating or limiting the biomass of phytoplankton at various ...200817959218
elucidating the factors influencing the biodegradation of cylindrospermopsin in drinking water sources.the cyanotoxin cylindrospermopsin (cyn) is produced by several species of cyanobacteria and can be persistent in drinking waters supplies, which is of major concern to water authorities because of its potential to severely compromise human health. consequently, there is a need to fully understand the persistence of cyn in water supplies, in particular, to determine whether this toxin is readily degraded by endemic aquatic organisms. this study provides insights into the environmental factors tha ...200818214886
effects of a saxitoxin-producer strain of cylindrospermopsis raciborskii (cyanobacteria) on the swimming movements of cladocerans.this study evaluated the effects of a saxitoxin-producer strain (t3) of the cyanobacteria species cylindrospermopsis raciborskii on the swimming movements of three cladoceran species (daphnia gessneri, d. pulex, and moina micrura). acute toxicity bioassays were designed to access the effects of t3 strain, of a nonsaxitoxin producer strain (nplp-1) of the same species and of a raw water sample from funil reservoir (rio de janeiro, brazil), that contained this and other cyanobacteria. in the acute ...200818214915
an examination of the antibiotic effects of cylindrospermopsin on common gram-positive and gram-negative bacteria and the protozoan naegleria lovaniensis.the importance of the toxin cylindrospermopsin to the function and fitness of the cyanobacteria that produce it remains a matter of conjecture. given that the structure of cylindrospermopsin has commonalities with other antibacterial protein synthesis inhibitors, such as streptomycin, authors tested the possibility that the toxin might act as an antibacterial compound that can kill competing microbes. escherichia coli, bacillus subtilis, staphylococcus aureus, and pseudomonas aeruginosa were tes ...200818214928
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