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cloning and biochemical characterization of the hectochlorin biosynthetic gene cluster from the marine cyanobacterium lyngbya majuscula.cyanobacteria, or blue-green algae, are a rich source of novel bioactive secondary metabolites that have potential applications as antimicrobial or anticancer agents or useful probes in cell biology studies. a jamaican collection of the cyanobacterium lyngbya majuscula has yielded several unique compounds including hectochlorin ( 1) and the jamaicamides a-c ( 5- 7). hectochlorin has remarkable antifungal and cytotoxic properties. in this study, we have isolated the hectochlorin biosynthetic gene ...200718001088
the recombinant beta subunit of c-phycocyanin inhibits cell proliferation and induces apoptosis.c-phycocyanin (c-pc) from blue-green algae has been reported to have various pharmacological characteristics, including anti-inflammatory and anti-tumor activities. in this study, we expressed the beta-subunit of c-pc (ref to as c-pc/beta) in escherichia coli. we found that the recombinant c-pc/beta has anti-cancer properties. under the treatment of 5 microm of the recombinant c-pc/beta, four different cancer cell lines accrued high proliferation inhibition and apoptotic induction. substantially ...200716740358
the zebrafish (danio rerio) embryo as a model system for identification and characterization of developmental toxins from marine and freshwater microalgae.the zebrafish (danio rerio) embryo has emerged as an important model of vertebrate development. as such, this model system is finding utility in the investigation of toxic agents that inhibit, or otherwise interfere with, developmental processes (i.e. developmental toxins), including compounds that have potential relevance to both human and environmental health, as well as biomedicine. recently, this system has been applied increasingly to the study of microbial toxins, and more specifically, as ...200717020820
the structure of a cyanobacterial bicarbonate transport protein, cmpa.cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. to compensate for the low selectivity of rubisco for co2 over o2, cyanobacteria have developed highly efficient co2-concentrating machinery of which the abc transport system cmpabcd from synechocystis pcc 6803 is one component. here, we have described the structure of the bicarbonate-binding protein cmpa in the absence ...200717121816
benthic cyanobacteria (oscillatoriaceae) that produce microcystin-lr, isolated from four reservoirs in southern california.cyanobacteria that produce the toxin microcystin have been isolated from many parts of the world. most of these organisms are planktonic; however, we report on several microcystin-producing benthic filamentous cyanobacterial isolates from four drinking-water reservoirs in southern california (usa): lake mathews, lake skinner, diamond valley lake (dvl), and lake perris. some samples of benthic material from these reservoirs tested positive for microcystin by an elisa tube assay, and all the posit ...200717126876
a long-term copper exposure on freshwater ecosystem using lotic mesocosms: primary producer community responses.copper is commonly used as an algicide and plant herbicide in the aquatic environment. despite of its frequent application in rivers, ponds and lakes, few studies have been performed at the ecosystem level on primary producers' communities. a long-term lotic mesocosms study was carried on, in 20m long channels, under environmentally realistic concentrations of copper (0, 5, 25 and 75 microgl(-1)) delivered continuously for 18 months. results showed significant effects at the 25 and 75 microgl(-1 ...200717239970
addressing public health risks for cyanobacteria in recreational freshwaters: the oregon and vermont framework.toxigenic cyanobacteria, commonly known as blue green algae, are an emerging public health issue. the toxins produced by cyanobacteria have been detected across the united states in marine, freshwater and estuarine systems and associated with adverse health outcomes. the intent of this paper is to focus on how to address risk in a recreational freshwater scenario when toxigenic cyanobacteria are present. several challenges exist for monitoring, assessing and posting water bodies and advising the ...200717283602
vertical profile of algal distribution during aeration prior to intake tower for safe drinking water.blue-green algae or cyanobacteria comprise a diverse group of organisms, all of which generate potent natural toxins, as well as characteristic odours. in particular, blue-green algae, such as microcystis and anabaena, are often detected abundantly in surface water used as a drinking water resource. in order to confirm our ability to provide safe drinking water even during a water bloom, we have conducted an investigation into the vertical distribution of algae during aeration prior to entry int ...200717305156
[cyanobacterial toxins in bank filtrate. under which conditions is their elimination reliable?].cyanobacterial toxins are substances produced by cyanobacteria or blue-green algae. they can occur in surface waters worldwide and have to be reliably removed when using affected surface waters as a drinking water source. bank filtration has been used for 150 years for drinking water (pre-)treatment. it utilizes natural elimination processes like sorption and degradation in the sub-surface. retention of cells on the sediment surface is the most prominent process for eliminating these primarily c ...200717334885
toxins of cyanobacteria.blue-green algae are found in lakes, ponds, rivers and brackish waters throughout the world. in case of excessive growth such as bloom formation, these bacteria can produce inherent toxins in quantities causing toxicity in mammals, including humans. these cyanotoxins include cyclic peptides and alkaloids. among the cyclic peptides are the microcystins and the nodularins. the alkaloids include anatoxin-a, anatoxin-a(s), cylindrospermopsin, saxitoxins (stxs), aplysiatoxins and lyngbyatoxin. both b ...200717195276
anatoxin-a and its metabolites in blue-green algae food supplements from canada and portugal.blue-green algae and spirulina are marketed in health food stores and over the internet as food supplements in canada, the united states, and europe. the reported benefits of consuming these products include improved digestion, strengthening of the immune system, and relief from the symptoms of attention deficit disorder. some of these products have been found to contain elevated concentrations of microcystins, which are known hepatotoxins. in addition to producing microcystins, anabaena sp. and ...200717388076
steroidal constituents of rice (rryza sativa) hulls with algicidal and herbicidal activity against blue-green algae and duckweed.two new compounds, 14-methyl stigmast-9(11)-en-3alpha-ol-3beta-d-glucopyranoside (1) and cholest-11-en-3beta, 6beta, 7alpha, 22beta-tetraol-24-one-3beta-palmitoleate (2), along with the known compound beta-sitosteryl-3beta-d-glucopyranosyl-6'-linoleiate (3), were isolated from the methanolic extract of rice (oryza sativa) hulls. the structures of the two new compounds were elucidated using one- and two-dimensional nmr in combination with ir, ei/ms, fab/ms, hr-ei/ms and hr-fab/ms. in bioassays wi ...200717439014
biomedicinals from the phytosymbionts of marine invertebrates: a molecular approach.marine invertebrate animals such as sponges, gorgonians, tunicates and bryozoans are sources of biomedicinally relevant natural products, a small but growing number of which are advancing through clinical trials. most metazoan and anthozoan species harbour commensal microorganisms that include prokaryotic bacteria, cyanobacteria (blue-green algae), eukaryotic microalgae, and fungi within host tissues where they reside as extra- and intra-cellular symbionts. in some sponges these associated micro ...200717560324
[effect of nitrogen and phosphorus on growth and competition of m. aeruginosa and s. quadricauda].in order to disclosure the formation rule of predominant species in different nutrition conditions, three kinds of nutrition concentration were selected for the competition experiments with the common species of blue-green algae bloom microcystis aeruginosa and the common species of green algae bloom scenedesmus quadricauda. the competition relation was analysed by the competition parameters. the results indicate, in low nutrition, scenedesmus quadricauda can stimulate the growth of microcystis ...200717674727
hepatoprotective efficacy of certain flavonoids against microcystin induced toxicity in mice.toxic cyanobacteria (blue-green algae) water blooms have become a serious problem in several industrialized areas of the world. microcystin-lr (mc-lr) is a cyanobacterial heptapeptide that represents acute and chronic hazards to animal and human health. identification of suitable chemprotectants against microcystin is essential considering human health hazards. in the present study, we have evaluated the protective efficacy of three flavanoids namely quercetin (200 mg/kg), silybin (400 mg/kg), a ...200717696131
[application of elisa for microcystins detection].microcystins (mcs) may be group of closely related toxic cyclic heptapeptides produced by common cyanobacteria (blue-green algae). their toxicity could be associated with specific inhibition of intracellular protein phosphatases type-1 and type-2a (pp1 and pp2a, respectively). there are some methods for analyzing and detecting mcs in aquatic environment, such as hplc, lc-ms, ppia, and elisa. this review introduces advances on mcs determined by enzyme-linked immunosorbent assay (elisa), and estim ...200717712969
a comprehensive immunoassay for the detection of microcystins in waters based on polyclonal antibodies.microcystins (mcs) are a group of closely related toxic cyclic heptapeptides produced by common cyanobacteria (blue-green algae), and microcystin-leucine-arginine (mc-lr) is among the most frequent and most toxic microcystin congeners. in this study, a free amino group was introduced to mc-lr at its seventh amino acid residue with 2-mercaptoethylamine, and the product aminoethyl-mc-lr was coupled to bovine serum albumin (bsa) and horseradish peroxidise (hrp) by glutaraldehyde to be complete anti ...200617723494
water quality and phytoplankton characteristics in the palk bay, southeast coast of india.the present study was carried out to determine the water quality in terms of physicochemical characteristics and plankton distribution in the coastal waters of kattumavadi, palk bay for a period of one year from april 2002 to march 2003. air and surface water temperatures varied from 28 degrees c to 32.50 degrees c and from 27.5 to 32.0 degrees c while light extinction coefficient (lec) varied between 0.95 and 1.85. salinity ranged from 26.0 to 34.5 per thousand and the ph ranged between 7.95 an ...200617402250
structural and functional characterization of microcystin detoxification-related liver genes in a phytoplanktivorous fish, nile tilapia (oreochromis niloticus).liver genes related to phase i and phase ii detoxification, as well as inhibition of reactive oxygen species (ros) production, were cloned, and their response to microcystin-lr (mc-lr) and lipopolysaccharide (lps) exposure via intraperitoneal injection, was determined in a phytoplanktivorous fish, nile tilapia (oreochromis niloticus). the cloned full-length cdna of tilapia soluble glutathione s-transferase (sgst) was classified as alpha-class gst based on their amino acid sequence identity with ...200617045849
petroleum pollutant degradation by surface water microorganisms.it is well known that the composition of petroleum or some of its processing products changes in the environment mostly under the influence of microorganisms. a series of experiments was conducted in order to define the optimum conditions for an efficient biodegradation of petroleum pollutant, or bioremediation of different segments of the environment. the aim of these investigations was to show to what extent the hydrocarbons of a petroleum pollutant are degraded by microbial cultures which wer ...200617067026
renoprotective effect of spirulina fusiformis on cisplatin-induced oxidative stress and renal dysfunction in rats.cisplatin is an effective chemotherapeutic agent used in the treatment of a wide array of both pediatric and adult malignancies. dose-dependent and cumulative nephrotoxicity is the major toxicity of this compound, sometimes requiring a reduction in dose or discontinuation of treatment. recent evidences have implicated oxidative and nitrosative stress in cisplatin-induced nephrotoxicity. spirulina fusiformis, blue-green algae, is claimed to be a potential antioxidant. the present study was design ...200616703798
monitoring algal toxins in lake water by liquid chromatography tandem mass spectrometry.microcystins (mcs) and cylindrospermopsin (cyl) are potent natural toxins produced by cyanobacteria (blue-green algae) that grow worldwide in eutrophic freshwaters and cause animal and human water-based toxicoses. the main purpose of this work has been assessing the contamination levels of some mcs and cyl in eutrophic italian lake (albano) water. to do this, we have developed an original analytical method involving mc extraction with a sorbent (carbograph 4) cartridge. cyl is a highly polar com ...200616719091
elisa and lc-ms/ms methods for determining cyanobacterial toxins in blue-green algae food supplements.the use of natural products as a diet supplement is increasing worldwide but sometimes is not followed by adequate sanitary controls and analyses. twenty samples of pills and capsules of lyophilised cyanobacteria (blue-green algae), commercialised in italy as dietary supplements, were found positive at the vibrio fischeri bioassay. further analyses with elisa and lc-ms/ms methods revealed the presence of four microcystin (mc) analogues, mc-lr, -yr, -la, -rr and two demethylated forms of mc-rr. t ...200616753920
low-pressure membrane (mf/uf) fouling associated with allochthonous versus autochthonous natural organic matter.natural organic matter (nom) isolates/fractions; organic colloids, and hydrophobic (hpo), transphilic (tpi), and hydrophilic (hpi) fractions; isolated from a natural surface water as an allochthonous source, and in the form of algal organic matter (aom) derived from blue green algae as an autochthonous source, were investigated in low-pressure membrane filtration. the most significant flux decline was caused by organic colloids, with an intermediate flux decline caused by aom derived (isolated) ...200616777172
atomic structure of a nitrate-binding protein crucial for photosynthetic productivity.cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of all aquatic food chains by fixing carbon and nitrogen into cellular biomass. the single most important nutrient for photosynthesis and growth is nitrate, which is severely limiting in many aquatic environments particularly the open ocean. it is therefore not surprising that nrta, the solute-binding component of the high-affinity nitrate abc transporter, is the single-most abundant prote ...200616777960
molecular cloning and characterization of alpha-class glutathione s-transferase gene from the liver of silver carp, bighead carp, and other major chinese freshwater fishes.two full-length cdnas encoding glutathione s-transferase (gst) were cloned and sequenced from the hepatopancreas of planktivorous silver carp (hypophthalmichthys molitrix) and bighead carp (aristichthys nobilis). the silver carp and bighead carp gst cdna were 920 and 978 bp in length, respectively, and both contained an open reading frame that encoding 223 amino acids. partial gst cdna sequences were also obtained from the liver of grass carp (ctenopharyngodon idellus), crucian carp (carassius a ...200616788955
survival of blue-green and green algae under stress conditions.terrestrial blue-green algae scytonema millei, phormidium bohneri and lyngbya mesotricha survived to 100 % at atmospheric temperatures of 5-36 degrees c and relative humidity 55-100 % in rainy, winter and spring seasons but the survival was 15-25 % in summer when atmospheric temperature reached 48 degrees c and relative humidity was < or =23 %. microcoleus chthonoplastes maximum survival was =80 % in rainy season followed by a decrease to =1/2 and 1/4 level in winter and spring, respectively; it ...200616821721
spirulina attenuates cyclosporine-induced nephrotoxicity in rats.cyclosporine (csa) causes a dose-related decrease in renal function in experimental animals and humans. the generation of reactive oxygen species (ros) has been implicated in csa-induced nephrotoxicity. it was previously shown that spirulina, a blue-green algae, with antioxidant properties effectively attenuated the doxorubicin-induced cardiotoxicity in mice and cisplatin-induced nephrotoxicity in rat. the present study investigated the nephroprotective role of spirulina against csa-induced neph ...200616858688
isolation and identification of antialgal compounds from the leaves of vallisneria spiralis l. by activity-guided fractionation.vallisneria spiralis linn., a common submerged macrophyte, is widely available in quiet waters of lakes, ponds, marshes and streams in southeast asia. v. spiralis plays a significant role not only in decreasing eutrophication of water body for its productivity, but also in inhibiting the growth of blue-green algae? the aim of the paper involves the isolation and identification of allelochemicals from extracts of v. spiralis by activity-guided fractionation and column chromatography.200616910120
[study progress on pollution and liver cancer promotion of microcystins].eutrophication of fresh water lakes and ponds has caused the occurrence of cyanobacteria. microcystins (mcs) is a class of toxic cyclic heptapeptide, which may be produced by some strains of various blue-green algae. it has become potential hazardous material in aquatic environments for its toxic, distribution and stability. mcs has been showed to be extremely potent hepatotoxins and been viewed as a promoter of liver tumor. in this review, the pollution condition of mcs and its hepatotoxins as ...200616921774
photodynamic action of c-phycocyanins obtained from marine and fresh water cyanobacterial cultures: a comparative study using epr spin trapping technique.c-phycocyanins, major biliproteins of blue green algae (cyanobacteria), widely used as colourants in food and cosmetics are known for their antioxidant as well as therapeutic potential. recent claims indicating phycobiliproteins exert stronger photodynamic action on tumor cells than clinically approved hematoporphyrin derivatives motivate us to investigate the photodynamic action of two newly isolated c-phycocyanins from phormidium [phr] and lyngbya [ly] spp, respectively in comparison with know ...200617015260
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 ...200616099074
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 ...200616304634
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 ...200616445613
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 ...200616455146
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 ...200616465560
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 ...200616556970
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 ...200616568763
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. ...200616573712
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 ...200616623944
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 ...200616626770
antioxidant properties of recombinant allophycocyanin expressed in escherichia coli.allophycocyanin (apc) is the main core component of phycobilisome found in blue-green algae. the apo-allophycocyanin and its subunits were expressed in escherichia coli and their antioxidant properties were evaluated using deoxyribose assay. the result showed that both recombinant allophycocyanin fused with maltose binding protein (mbp) tag and 6 x his-tag and their alpha or beta subunits can scavenge hydroxyl radicals successfully, and the separated alpha or beta subunits had a higher inhibitio ...200616647860
generation and characterization of polyclonal antibodies against microcystins-application to immunoassays and immunoaffinity sample preparation prior to analysis by liquid chromatography and uv detection.polyclonal antibodies against microcystin-lr (mc-lr), a cyclic heptapeptide toxin, were generated in rabbits using mc-lr-bsa. an enzyme-linked immunosorbent assay (elisa) was developed for the characterization of the antibodies and their potential use for analytical purposes. the concentration of mc-lr that inhibits 50% of antibody-antigen binding (ic(50)) was 0.5mugl(-1) for the indirect elisa format and 0.9mugl(-1) for the direct elisa, using mc-lr-horseradish peroxidase conjugate. the limit o ...200618970757
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 ...200516526457
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 ...200516372368
[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 ...200516400983
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 ...200516305143
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 ...200516114457
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 ...200516127666
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 ...200516291202
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 ...200516294828
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 ...200515863101
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 ...200515869202
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 ...200515892069
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 ...200515993924
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 ...200515698647
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 ...200515712332
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 ...200515737677
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 ...200515804520
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 ...200515820106
environmental impacts of cooling system on abou qir bay.this study was conducted to evaluate the impacts of cooling water on cooling system of abou qir power plant and on the receiving abou qir bay. abou qir power plant is a conventional steam electric power plant located in alexandria governorate, egypt. water and biota samples were collected monthly from cooling water and abou qir bay over a year. heavy metals, radionuclide, anions and total hydrocarbons were analyzed in the samples using instrumental neutron activation analysis (inaa), gamma-ray s ...200517187744
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
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 ...200414706513
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 ...200414710884
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 ...200415450932
[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 ...200415481916
[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 ...200415481938
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 ...200415491661
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 ...200415553464
[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 ...200415586902
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 ...200414987858
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 ...200415016519
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 ...200415032833
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 ...200415053526
[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.200415098475
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 ...200415217247
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.200415234278
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 ...200415237637
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 ...200415367629
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.200415369755
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 ...200415388760
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 ...200314502757
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 ...200314509843
inhibition of enterovirus 71-induced apoptosis by allophycocyanin isolated from a blue-green alga spirulina platensis.enterovirus 71 infection causes significant morbidity and mortality in children, yet there is no effective treatment. in this study, a protein-bound pigment, allophycocyanin purified from blue-green algae is first reported to exhibit anti-enterovirus 71 activity. allophycocyanin neutralized the enterovirus 71-induced cytopathic effect in both human rhabdomyosarcoma cells and african green monkey kidney cells. the 50% inhibitory concentration of allophycocyanin for neutralizing the enterovirus 71 ...200312629652
cyst-based toxicity tests. xi. influence of the type of food on the intrinsic growth rate of the rotifer brachionus calyciflorus in short-chronic toxicity tests.as important members of zooplankton communities worldwide, rotifers are used extensively in ecotoxicological research. chronic rotifer tests are, however, dependent on live algal food which adds to the complexity, the variability and the costs of these bioassays. to bypass the former problem, experiments have been undertaken with the freshwater rotifer brachionus calyciflorus, to determine their intrinsic growth rate (r) when fed for 48 h on a mixture of green algae (raphidocelis subcapitata rec ...200312656256
multiple splice variants encode a novel adenylyl cyclase of possible plastid origin expressed in the sexual stage of the malaria parasite plasmodium falciparum.we report the characterization of an unusual adenylyl cyclase gene from plasmodium falciparum, here designated pfacalpha. the level of mrna expression is maximum during development of gametocytes (the sexual blood stage of the parasite life cycle). the gene is highly interrupted by 22 introns, and reverse transcriptase-pcr analysis revealed that there are multiple mrna splice variants. one intron has three alternative 3'-splice sites that confer the potential to encode distinct forms of the enzy ...200312668669
c-phycocyanin, a selective cyclooxygenase-2 inhibitor, induces apoptosis in lipopolysaccharide-stimulated raw 264.7 macrophages.c-phycocyanin (c-pc) is one of the major biliproteins of spirulina platensis, a blue green algae, with antioxidant and radical scavenging properties. it is also known to exhibit anti-inflammatory and anti-cancer properties. however, the mechanism of action of c-pc is not clearly understood. previously, we have shown that c-pc selectively inhibits cyclooxygenase-2 (cox-2), an inducible isoform that is upregulated during inflammation and cancer. in view of the reported induction of apoptosis in ca ...200312711327
cyanobacterial toxins: a growing environmental concern.unusual blooms of toxic cyanobacteria in water bodies have drawn attention of environmentalists world over. major blooms of anabaena, microcystis and nodularia in water storage reservoirs, rivers and lakes leading to adverse health effects have been reported from australia, england and many other parts of the world. an overview of the morphology and taxonomy of these toxic blue-green algae; their possible sources of contamination including dietary supplements and their potential to cause hepatot ...200312729683
microalgal metabolites.the extraordinary chemical diversity seen in the cyanobacteria (blue-green algae) is especially pronounced in the ubiquitous tropical marine species, lyngbya majuscula. the gene clusters responsible for the production of some of the secondary metabolites have recently been elucidated. the dinoflagellates, which are lower eukaryotic algae, also demonstrate chemical diversity and produce unique polycyclic ethers of polyketide origin. a new mechanism for the formation of the truncated polyketide ba ...200312831899
simulation of carbon reserve dynamics in microcystis and its influence on vertical migration with yoyo model.blue-green algae control their buoyancy depending upon the surrounding conditions. this process is essential for cyanobacteria development and can account for their dominance in eutrophic waters in summer. in order to determine the main regulating factors of those movements, we developed a mechanistic and deterministic model, based on differential equations, that simulates the vertical migration of microcystis sp. in microcystis, buoyancy regulation results from the dynamics of the carbohydrate ...200312876887
bio-diversity: an effective safety net against environmental pollution.biodiversity is the feedstock for the biotechnology industry. hence, the conservation, enhancement and sustainable and equitable use of biodiversity should be accorded high priority in all national environment protection programmes. lichens serve as useful indicators of environmental health. similarly, several blue green algae help to sequester salt from water. there is need for the more widespread use of such biomonitoring and bioremediation agents. bioprospecting research designed to identify ...200312963289
interaction between microcystins of different hydrophobicities and lipid monolayers.microcystins (mc) are a group of amphiphatic peptide hepatotoxins and protein phosphatase inhibitors produced by certain cyanobacteria (blue-green algae). microcystins are believed to require an active transport mechanism to penetrate the plasma membranes of animal cells. in this study the surface barostat technique showed that two more hydrophobic microcystins mc-lf, containing leu and phe, and mc-lw, containing leu and trp, had a higher surface activity on an egg phosphatidylcholine-cholestero ...200312565758
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 ...200314733387
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 ...200314617790
water treatment plants assessment at talkha power plant.talkha power plant is the only power plant located in el-mansoura. it generates electricity using two different methods by steam turbine and gas turbine. both plants drew water from river nile (208 m3 /h). the nile raw water passes through different treatment processes to be suitable for drinking and operational uses. at talkha power plant, there are two purification plants used for drinking water supply (100 m3/h) and for water demineralization supply (108 m3/h). this study aimed at studying th ...200217216967
toxins and bioactive compounds from cyanobacteria and their implications on human health.many species of cyanobacteria (blue-green algae) produce secondary metabolites with potent biotoxic or cytotoxic properties. these metabolites differ from the intermediates and cofactor compounds that are essential for cell structural synthesis and energy transduction. the mass growth of cyanobacteria which develop in fresh, brackish and, marine waters commonly contain potent toxins. cyanobacterial toxins or cyanotoxins are responsible for or implicated in animal poisoning, human gastroenteritis ...200212597562
cyanopeptide analogues: new lead structures for the design and synthesis of new thrombin inhibitors.this contribution deals with the structure-based design and syntheses of the new serine protease inhibitors ra-1001 and ra-1002, which are analogues of the blue-green algae derived cyanopeptide aeruginosin 98-b. both compounds inhibit thrombin with ki values of 5.6 microm and 8.7 microm, respectively.200212611274
acyl group specificity at the active site of tetrahydridipicolinate n-succinyltransferase.tetrahydrodipicolinate n-succinyltransferase (dapd) catalyzes the succinyl-coa-dependent acylation of l-2-amino-6-oxopimelate to 2-n-succinyl-6-oxopimelate as part of the succinylase branch of the meso-diaminopimelate/lysine biosynthetic pathway of bacteria, blue-green algae, and plants. this pathway provides meso-diaminopimelate as a building block for cell wall peptidoglycan in most bacteria, and is regarded as a target pathway for antibacterial agents. we have solved the x-ray crystal structu ...200211910040
[ultrastructure of yersinia pseudotuberculosis in the process of their reversible transition into the dormant (non-culturable) state in association with blue-green algae].the ultrastructural organization of y. pseudotuberculosis in the process of the transition of vegetative cells into the dormant (noncultivable) state in interaction with blue-green algae of the species anabaena variabilis was studied by the method of transmission electron microscopy. the use of type specific y. pseudotuberculosis serum made it possible to identify y. pseudotuberculosis cells in the bacterial association and to find out whether their antigenic properties remained intact in time. ...200211949247
factors influencing the abundance of japanese encephalitis vectors in ricefields in india--ii. biotic.the relationship of insect predators and phytoplankton with the abundance of culex tritaeniorhynchus giles, cx. vishnui theobald and cx. pseudovishnui colless mosquito larvae and pupae (diptera: culicidae) in ricefields was investigated during three rice growing seasons. notonectids were the most abundant insect predators, whereas diatoms dominated among phytoplankton. multiple regression analysis showed that the occurrence of notonectids (both nymphs and adults) was negatively associated with l ...200211963972
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