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Sample records for alga cryptomonas paramecium

  1. Paramecium

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    Gortz, H.D.

    1988-01-01

    This book presents a survey of the current knowledge and research on Paramecium. Scientists find Paramecium a most useful object for the study of basic biological enigmas. To cover all aspects on the cell biology, cell physiology, genetics, developmental biology, ecology, endocytobiology, and molecular biology of Paramecium, specialists were asked to review their own fields. They have also included quite recent studies on the cytoskeleton, endo- and exocytosis, aging, sensory and membrane physiology, electrophysiology and motility.

  2. Isolation and characterization of a virus (CvV-BW1 that infects symbiotic algae of Paramecium bursaria in Lake Biwa, Japan

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    Kasahara Masahiro

    2010-09-01

    Full Text Available Abstract Background We performed an environmental study of viruses infecting the symbiotic single-celled algae of Paramecium bursaria (Paramecium bursaria Chlorella virus, PBCV in Lake Biwa, the largest lake in Japan. The viruses detected were all Chlorella variabilis virus (CvV = NC64A virus. One of them, designated CvV-BW1, was subjected to further characterization. Results CvV-BW1 formed small plaques and had a linear DNA genome of 370 kb, as judged by pulsed-field gel electrophoresis. Restriction analysis indicated that CvV-BW1 DNA belongs to group H, one of the most resistant groups among CvV DNAs. Based on a phylogenetic tree constructed using the dnapol gene, CvV was classified into two clades, A and B. CvV-BW1 belonged to clade B, in contrast to all previously identified virus strains of group H that belonged to clade A. Conclusions We conclude that CvV-BW1 composes a distinct species within C. variabilis virus.

  3. Morphological examination and phylogenetic position of two newly recorded freshwater Cryptomonas species (Cryptophyceae) from China

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    Shuang XIA; Guo-Xiang LIU; Zheng-Yu HU

    2013-01-01

    Two freshwater cryptomonads,Cryptomonas obovata Skuja and Cryptomonas curvata Ehrenberg,are reported for the first time in China.Identification was based on light microscopy and scanning electron microscopy.Cryptomonas obovata was characterized by its obovoid cell shape,lobed cell subapex,and a large number of starch grains.Cryptomonas curvata was characterized by its sigmoid cell shape,rostrate cell apex,and numerous pyrenoids.Nuclear and nucleomorph small subunit rDNA phylogenetic analyses revealed Cryptomonas curvata collected from China was very similar to C.curvata strains cultivated in Germany,and the closest relative of C.obovata was found to be C.pyrenoidifera Geitler.Controversially,some quite morphologically different members of the genus Cryptomonas Ehrenberg were clustered into the same group in phylogeny analyses,which emphasized the complexity of the genus Cryptomonas.

  4. Is paramecium swimming autonomic?

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    Bandyopadhyay, Promode R.; Toplosky, Norman; Hansen, Joshua

    2010-11-01

    We seek to explore if the swimming of paramecium has an underlying autonomic mechanism. Such robotic elements may be useful in capturing the disturbance field in an environment in real time. Experimental evidence is emerging that motion control neurons of other animals may be present in paramecium as well. The limit cycle determined using analog simulation of the coupled nonlinear oscillators of olivo-cerebellar dynamics (ieee joe 33, 563-578, 2008) agrees with the tracks of the cilium of a biological paramecium. A 4-motor apparatus has been built that reproduces the kinematics of the cilium motion. The motion of the biological cilium has been analyzed and compared with the results of the finite element modeling of forces on a cilium. The modeling equates applied torque at the base of the cilium with drag, the cilium stiffness being phase dependent. A low friction pendulum apparatus with a multiplicity of electromagnetic actuators is being built for verifying the maps of the attractor basin computed using the olivo-cerebellar dynamics for different initial conditions. Sponsored by ONR 33.

  5. Paramecium aurelia revisited.

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    Coleman, A W

    2005-01-01

    The species Paramecium aurelia sensu latu, containing 15 sexually isolated subspecies (syngens), is the classic example of a sibling species complex in the ciliates. Using DNA sequence comparison, it is now possible to see whether this example parallels other studied sibling species complexes. We sequenced the internal transcribed spacer (ITS) region of the nuclear ribosomal cistron for 13 of the syngens plus two other Paramecium species and several Tetrahymena spp. Using available spirotrich sequences of the internal transcribed spacer 2 (ITS2), we established the RNA transcript folding pattern for ciliates. Ciliates exhibit the two highly conserved helices in their RNA transcript folding pattern in common with other eukaryotes, despite their unusual nuclear behavior and their presumed low copy number of micronuclear ribosomal repeats. Consequently, the set of 111-116 ITS2 nucleotide positions that are relatively conserved in evolution can be derived and used for comparative analysis. Mating behavior (i.e. gamete agglutination and fusion) is the character showing greatest correlation with the degree of ITS2 evolution in the P. aurelia complex, as also found in other eukaryotes. The degree of change in the ITS2 relatively conserved sequences found among the sibling species of P. aurelia is the same degree as found among the sibling species of the Drosophila melanogaster-mauritania-sechellia-simulans-yakuba species complex. The relatively conserved subregion of ITS2, determined from transcript secondary structure, is a tool for identifying the level of the biological species in the absence of knowledge of sexual compatibility in both micro- and macro-eukaryote species complexes.

  6. Effects of light intensity and temperature on Cryptomonas ovata (Cryptophyceae) growth and nutrient uptake rates

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    Cloern, James E.

    1977-01-01

    Specific growth rate of Cryptomonas ovata var. palustris Pringsheim was measured in batch culture at 14 light-temperature combinations. Both the maximum growth rate (μm) and optimum light intensity (Iopt) fit an empirical function that increases exponentially with temperature up to an optimum (Topt), then declines rapidly as temperature exceeds Topt. Incorporation of these functions into Steele's growth equation gives a good estimate of specific growth rate over a wide range of temperature and light intensity. Rates of phosphate, ammonium and nitrate uptake were measured separately at 16 combinations of irradiance and temperature and following a spike addition of all starved cells initially took up nutrient at a rapid rate. This transitory surge was followed by a period of steady, substrate-saturated uptake that persisted until external nutrient concentration fell. Substrate-saturated NO3−-uptake proceeded at very slow rates in the dark and was stimulated by both increased temperature and irradiance; NH4+-uptake apparently proceeded at a basal rate at 8 and l4 C and was also stimulated by increased temperature and irradiance. Rates of NH4−-uptake were much higher than NO3−-uptake at all light-temperature combinations. Below 20 C, PO4−3-uptake was more rapid in dark than in light, but was light enhanced at 26 C.

  7. Paramecium tredecaurelia of the Paramecium aurelia complex in Israel.

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    Przyboś, Ewa; Nevo, Eviatar; Pavlicek, Tomas

    2002-01-01

    The paper concerns the finding of a new habitat (Kiryat Motzkin, north of Haifa, Israel) of Paramecium tredecaurelia from the P. aurelia complex. This is only the forth known locality of the species in the world. Previously, its strains were obtained from widely separated localities: the River Seine, Paris, France; Benenitra, Madagascar, and the Cuernavaca Valley, Taxco, Mexico. The studied strain originating from Israel was identified as P. tredecaurelia on the basis of the strong (90%) conjugation between the complementary mating type of the examined clones with the appropriate standard strain 209 of P. tredecaurelia from Paris, France (restricted to odd mating type). However, the strain from Israel is restricted to the even mating type.

  8. ParameciumDB: a community resource that integrates the Paramecium tetraurelia genome sequence with genetic data.

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    Arnaiz, Olivier; Cain, Scott; Cohen, Jean; Sperling, Linda

    2007-01-01

    ParameciumDB (http://paramecium.cgm.cnrs-gif.fr) is a new model organism database associated with the genome sequencing project of the unicellular eukaryote Paramecium tetraurelia. Built with the core components of the Generic Model Organism Database (GMOD) project, ParameciumDB currently contains the genome sequence and annotations, linked to available genetic data including the Gif Paramecium stock collection. It is thus possible to navigate between sequences and stocks via the genes and alleles. Phenotypes, of mutant strains and of knockdowns obtained by RNA interference, are captured using controlled vocabularies according to the Entity-Attribute-Value model. ParameciumDB currently supports browsing of phenotypes, alleles and stocks as well as querying of sequence features (genes, UniProt matches, InterPro domains, Gene Ontology terms) and of genetic data (phenotypes, stocks, RNA interference experiments). Forms allow submission of RNA interference data and some bioinformatics services are available. Future ParameciumDB development plans include coordination of human curation of the near 40 000 gene models by members of the research community.

  9. ACUTE TOXICITY OF METALS: NICKEL AND ZINC TO PARAMECIUM BURSARIA AND ITS ENDOSYMBIONTS

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    Patrycja Zagata

    2015-02-01

    Full Text Available Paramecium bursaria is an unicellular organism, widely distributed in the freshwater environment, where heavy metals are common contaminants. The ciliates, also including Paramecium bursaria, are a very abundant group in aquatic ecosystems, what makes them effective biological indicators of water pollutants. Paramecium bursaria is the only Paramecium which has evolved a mutualistic relationship with algae and it harbors these endosymbionts in its own cytoplasm. The algae are also very effective bioindicators of some pollutants because of their ability to biosorption and bioaccumulation of heavy metals. The aim of this study was to determine the acute toxicity of two metals’ compounds: nickel chloride (NiCl2 and zinc chloride (ZnCl2 to Paramecium bursaria and its endosymbionts. The ciliates were incubated in solutions with 5x10-8 to 5x10-2g/dm3 of NiCl2 and with 5x10-8 to 5x10-2g/dm3 of ZnCl2, at the temperature of 180C, in the light/dark conditions (12L/12D. Microscopic observations of cell divisions rate, cell shape changes as well as the swimming behavior, were conducted after 24, 48, 72 and 120 hours of incubation in the tested solutions and were compared to the control sample. Microscopic observations revealed the lethal doses for both compounds, for nickel chloride 5x10-5g/dm3 and for zinc chloride 5x10-3. These observations also revealed that in lesser concentrations than the lethal one, the slowdown and characteristic movements occur after metal addition. The PEA measurements of Fv/Fm parameter were carried out within 4 days, the first one after 24 hours of incubations. The results of this investigation has given us a view of a fluorescence efficiency by revealing that both compounds solutions can have the stimulating effect on Photosystem II, because the lowest fluorescence efficiency was measured in control samples.

  10. The actin multigene family of Paramecium tetraurelia

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    Wagner Erika

    2007-03-01

    Full Text Available Abstract Background A Paramecium tetraurelia pilot genome project, the subsequent sequencing of a Megabase chromosome as well as the Paramecium genome project aimed at gaining insight into the genome of Paramecium. These cells display a most elaborate membrane trafficking system, with distinct, predictable pathways in which actin could participate. Previously we had localized actin in Paramecium; however, none of the efforts so far could proof the occurrence of actin in the cleavage furrow of a dividing cell, despite the fact that actin is unequivocally involved in cell division. This gave a first hint that Paramecium may possess actin isoforms with unusual characteristics. The genome project gave us the chance to search the whole Paramecium genome, and, thus, to identify and characterize probably all actin isoforms in Paramecium. Results The ciliated protozoan, P. tetraurelia, contains an actin multigene family with at least 30 members encoding actin, actin-related and actin-like proteins. They group into twelve subfamilies; a large subfamily with 10 genes, seven pairs and one trio with > 82% amino acid identity, as well as three single genes. The different subfamilies are very distinct from each other. In comparison to actins in other organisms, P. tetraurelia actins are highly divergent, with identities topping 80% and falling to 30%. We analyzed their structure on nucleotide level regarding the number and position of introns. On amino acid level, we scanned the sequences for the presence of actin consensus regions, for amino acids of the intermonomer interface in filaments, for residues contributing to ATP binding, and for known binding sites for myosin and actin-specific drugs. Several of those characteristics are lacking in several subfamilies. The divergence of P. tetraurelia actins and actin-related proteins between different P. tetraurelia subfamilies as well as with sequences of other organisms is well represented in a phylogenetic

  11. Micro-particle transporting system using galvanotactically stimulated apo-symbiotic cells of Paramecium bursaria.

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    Furukawa, Shunsuke; Karaki, Chiaki; Kawano, Tomonori

    2009-01-01

    It is well known that Paramecium species including green paramecia (Paramecium bursaria) migrate towards the anode when exposed to an electric field in a medium. This type of a cellular movement is known as galvanotaxis. Our previous study revealed that an electric stimulus given to P bursaria is converted to a galvanotactic cellular movement by involvement of T-type calcium channel on the plasma membrane [Aonuma et al. (2007), Z. Naturforsch. 62c, 93-102]. This phenomenon has attracted the attention of bioengineers in the fields of biorobotics or micro-robotics in order to develop electrically controllable micromachineries. Here, we demonstrate the galvanotactic controls of the cellular migration of P bursaria in capillary tubes (diameter, 1-2 mm; length, 30-240 mm). Since the Paramecium cells take up particles of various sizes, we attempted to use the electrically stimulated cells of P bursaria as the vehicle for transportation of micro-particles in the capillary system. By using apo-symbiotic cells of P bursaria obtained after forced removal of symbiotic algae, the uptake of the particles could be maximized and visualized. Then, electrically controlled transportations of particle-filled apo-symbiotic P bursaria cells were manifested. The particles transported by electrically controlled cells (varying in size from nm to /m levels) included re-introduced green algae, fluorescence-labeled polystyrene beads, magnetic microspheres, emerald green fluorescent protein (EmGFP)-labeled cells of E. coli, Indian ink, and crystals of zeolite (hydrated aluminosilicate minerals with a micro-porous structure) and some metal oxides. Since the above demonstrations were successful, we concluded that P bursaria has a potential to be employed as one of the micro-biorobotic devices used in BioMEMS (biological micro-electro-mechanical systems).

  12. Magnetic field influence on paramecium motility

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    Rosen, M.F.; Rosen, A.D. (State Univ. of New York, Stony Brook (USA))

    1990-01-01

    The influence of a moderately intense static magnetic field on movement patterns of free swimming Paramecium was studied. When exposed to fields of 0.126 T, these ciliated protozoa exhibited significant reduction in velocity as well as a disorganization of movement pattern. It is suggested that these findings may be explained on the basis of alteration in function of ion specific channels within the cell membrane.

  13. [Epigenetics: Paramecium as a model system].

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    Meyer, Eric; Beisson, Janine

    2005-04-01

    Since the middle of the last century, Paramecium has appeared as an intriguing genetic model, displaying a variety of heritable characters which do not follow the Mendel laws but are cytoplasmically inherited. The analysis of the hereditary mechanisms at play in this eukaryotic unicellular organism has provided new insight into epigenetics mechanisms. Interestingly, the revealing phenomena concern two pecularities of Paramecium, its highly elaborate surface structure (with thousands of ciliary basal bodies as cytoskeleton organizers), and its nuclear dualism (coexistence of a diploid "germline" micronucleus and a highly polyploid somatic macronucleus devoted to transcription, which contains a rearranged version of the germline genome). Analysis of variant cortical organization has led to the concept of structural inheritance, implying that assembly of new organelles and supramolecular protein complexes is guided by pre-existing organization. Analysis of other cytoplasmically inherited characters revealed that the developing macronucleus is epigenetically programmed by the maternal macronucleus through RNA-mediated, homology-dependent effects, suggesting the transcriptome should be recognized as a third actor in cellular inheritance, along with the "structurome" and the genome.

  14. Lineage-specific variations of congruent evolution among DNA sequences from three genomes, and relaxed selective constraints on rbcL in Cryptomonas (Cryptophyceae

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    Tran Hoang-Dung

    2005-10-01

    Full Text Available Abstract Background Plastid-bearing cryptophytes like Cryptomonas contain four genomes in a cell, the nucleus, the nucleomorph, the plastid genome and the mitochondrial genome. Comparative phylogenetic analyses encompassing DNA sequences from three different genomes were performed on nineteen photosynthetic and four colorless Cryptomonas strains. Twenty-three rbcL genes and fourteen nuclear SSU rDNA sequences were newly sequenced to examine the impact of photosynthesis loss on codon usage in the rbcL genes, and to compare the rbcL gene phylogeny in terms of tree topology and evolutionary rates with phylogenies inferred from nuclear ribosomal DNA (concatenated SSU rDNA, ITS2 and partial LSU rDNA, and nucleomorph SSU rDNA. Results Largely congruent branching patterns and accelerated evolutionary rates were found in nucleomorph SSU rDNA and rbcL genes in a clade that consisted of photosynthetic and colorless species suggesting a coevolution of the two genomes. The extremely accelerated rates in the rbcL phylogeny correlated with a shift from selection to mutation drift in codon usage of two-fold degenerate NNY codons comprising the amino acids asparagine, aspartate, histidine, phenylalanine, and tyrosine. Cysteine was the sole exception. The shift in codon usage seemed to follow a gradient from early diverging photosynthetic to late diverging photosynthetic or heterotrophic taxa along the branches. In the early branching taxa, codon preferences were changed in one to two amino acids, whereas in the late diverging taxa, including the colorless strains, between four and five amino acids showed changes in codon usage. Conclusion Nucleomorph and plastid gene phylogenies indicate that loss of photosynthesis in the colorless Cryptomonas strains examined in this study possibly was the result of accelerated evolutionary rates that started already in photosynthetic ancestors. Shifts in codon usage are usually considered to be caused by changes in functional

  15. Symbiotic Chlorella variabilis incubated under constant dark conditions for 24 hours loses the ability to avoid digestion by host lysosomal enzymes in digestive vacuoles of host ciliate Paramecium bursaria.

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    Kodama, Yuuki; Fujishima, Masahiro

    2014-12-01

    Endosymbiosis between symbiotic Chlorella and alga-free Paramecium bursaria cells can be induced by mixing them. To establish the endosymbiosis, algae must acquire temporary resistance to the host lysosomal enzymes in the digestive vacuoles (DVs). When symbiotic algae isolated from the alga-bearing paramecia are kept under a constant dark conditions for 24 h before mixing with the alga-free paramecia, almost all algae are digested in the host DVs. To examine the cause of algal acquisition to the host lysosomal enzymes, the isolated algae were kept under a constant light conditions with or without a photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea for 24 h, and were mixed with alga-free paramecia. Unexpectedly, most of the algae were not digested in the DVs irrespective of the presence of the inhibitor. Addition of 1 mM maltose, a main photosynthetic product of the symbiotic algae or of a supernatant of the isolated algae kept for 24 h under a constant light conditions, did not rescue the algal digestion in the DVs. These observations reveal that unknown factors induced by light are a prerequisite for algal resistance to the host lysosomal enzymes.

  16. Genetic diversity in the Paramecium aurelia species complex.

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    Catania, Francesco; Wurmser, François; Potekhin, Alexey A; Przybos, Ewa; Lynch, Michael

    2009-02-01

    Current understanding of the population genetics of free-living unicellular eukaryotes is limited, and the amount of genetic variability in these organisms is still a matter of debate. We characterized-reproductively and genetically-worldwide samples of multiple Paramecium species belonging to a cryptic species complex, Paramecium aurelia, whose species have been shown to be reproductively isolated. We found that levels of genetic diversity both in the nucleus and in the mitochondrion are substantial within groups of reproductively compatible P. aurelia strains but drop considerably when strains are partitioned according to their phylogenetic groupings. Our study reveals the existence of discrepancies between the mating behavior of a number of P. aurelia strains and their multilocus genetic profile, a controversial finding that has major consequences for both the current methods of species assignment and the species problem in the P. aurelia complex.

  17. Cloning of two genes encoding Rab7 in Paramecium.

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    Surmacz, Liliana; Wiejak, Jolanta; Wyroba, Elzbieta

    2006-01-01

    Rab7 is a small GTPase that plays a crucial role in the regulation of transport from early to late endosomes and lysosomes, phagosome maturation and in lysosomal biogenesis in mammalian cells. It contains conserved and unique sequence elements that mediate its function. Two Rab7 genes, Rab7a (703 bp) and Rab7b (707 bp) were identified in the unicellular eukaryote Paramecium by PCR amplification. They contain three short introns of different lengths (28-32 bp) and sequence located at identical positions in both genes. The presence of two Rab7 genes in the Paramecium genome was confirmed by Southern hybridization analysis performed with six different restriction enzymes. Expression of both genes was assessed by Northern blot and RT-PCR. Two transcripts of 1.8 and 2.2 kb were identified by hybridization analysis. The cloned complementary DNAs, both of 618 nucleotides in length, encode polypeptides of 206 amino acids that are 97.6% identical and differ in their C-termini. The predicted protein sequences of Rab7a and Rab7b contain all characteristic domains essential for Rab function: the effector domain (YRATVGADF) and four GTP-binding consensus sequences (GDSGVGKT, WDTAGQ, NKLD, SAK) as well as the prenylation motif (-CC) at the C-terminus indispensable for Rab binding to the membrane. Similarity searches revealed 81.6-82.1% homology of Paramecium Rab7 isoforms to human Rab7 and a lack of an insert typical for the Kinetoplastida - the species that appeared earlier in evolution. Paramecium is the first free-living lower eukaryote in which homologues of Rab7 have been identified that exhibit features similar to those of mammalian Rab7.

  18. Effects of static magnetic fields on growth of Paramecium caudatum.

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    Elahee, Khouaildi B; Poinapen, Danny

    2006-01-01

    Little is known about the influence of magnetic fields on growth of primitive eukaryotes such as the ciliate Paramecium. The latter are known to exhibit interesting characteristics such as electrotaxis, gravitaxis, and membrane excitability not commonly encountered in higher organisms. This preliminary study reports the effects of static magnetic fields on growth of Paramecium caudatum. The microorganisms were either permanently or 24 h on-and-off exposed to North and South polarity magnetic fields of average field gradient 4.3 T/m, for a period of 96 h. The growth rate and lag phase of all exposed populations were not significantly different from control ones exposed to normal geomagnetic field (P > .05). However, a significant negative shift in t(max) (time taken for maximum growth) of 10.5%-12.2% and a significant decrease (P fields, irrespective of polarity and exposure period reduce Paramecium growth by triggering early senescence of the population. The mechanisms underlying the small changes in population growth are unknown at this level, but various hypotheses have been suggested, including disorganization of swimming patterns resulting from (i) changes in cell membrane electric potential due to high speed movement through a gradient magnetic field and (ii) thermodynamic effect of anisotropic magnetic energies on cell membrane components affecting functioning of calcium channels. Altered swimming movements could in turn affect highly orchestrated processes such as conjugation, essential for survival of the organisms during development of adverse environmental conditions as thought to occur in the closed culture system used in this study.

  19. Fine oral filaments in Paramecium: a biochemical and immunological analysis.

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    Clerot, J; Iftode, F; Budin, K; Jeanmaire-Wolf, R; Coffe, G; Fleury-Aubusson, A

    2001-01-01

    In Paramecium, several kinds of the oral networks of fine filaments are defined at the ultrastructural level. Using the sodium chloride-treated oral apparatus of Paramecium as an antigen to produce monoclonal antibodies, we have begun to identify the proteins constituting these networks. Immunoblotting showed that all positive antibodies were directed against three bands (70-, 75-and 83-kD), which corresponded to quantitatively minor components of the antigen; there was no antibody specific for the quantitatively major components (58- and 62-kD). Immunolocalization with four of these antibodies directed against one or several of these three bands showed that these proteins are components of the fine filaments supporting the oral area; a decoration of the basal bodies and the outer lattice was also observed on the cortex. Immunofluorescence on interphase cells suggested that the three proteins colocalized on the left side of the oral apparatus, whereas only the 70-kD band was detected on the right side. During division, the antigens of the antibodies were detected at different stages after oral basal body assembly. The antibodies cross-reacted with the tetrins, which are oral filament-forming proteins in Tetrahymena, demonstrating that tetrin-related proteins are quantitatively minor components of the oral and the somatic cytoskeleton of Paramecium.

  20. Species of the Paramecium aurelia complex in Russia: new stands and overall distribution.

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    Potekhin, Alexey; Przyboś, Ewa; Nekrasova, Irina; Yashchenko, Varvara; Rautian, Maria

    2010-01-01

    New stands of Paramecium biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. novaurelia, and P. dodecaurelia were recorded in Russia. Especially interesting is the record of P. novaurelia in Vladivostok, Russian Far East, as it is a very rare species outside of Europe. The distribution of species of the Paramecium aurelia complex in Eurasia with emphasis on findings in Russia is discussed.

  1. Algae Resources

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    None

    2016-06-01

    Algae are highly efficient at producing biomass, and they can be found all over the planet. Many use sunlight and nutrients to create biomass, which contain key components—including lipids, proteins, and carbohydrates— that can be converted and upgraded to a variety of biofuels and products. A functional algal biofuels production system requires resources such as suitable land and climate, sustainable management of water resources, a supplemental carbon dioxide (CO2) supply, and other nutrients (e.g., nitrogen and phosphorus). Algae can be an attractive feedstock for many locations in the United States because their diversity allows for highpotential biomass yields in a variety of climates and environments. Depending on the strain, algae can grow by using fresh, saline, or brackish water from surface water sources, groundwater, or seawater. Additionally, they can grow in water from second-use sources such as treated industrial wastewater; municipal, agricultural, or aquaculture wastewater; or produced water generated from oil and gas drilling operations.

  2. ParameciumDB in 2011: new tools and new data for functional and comparative genomics of the model ciliate Paramecium tetraurelia.

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    Arnaiz, Olivier; Sperling, Linda

    2011-01-01

    ParameciumDB is a community model organism database built with the GMOD toolkit to integrate the genome and biology of the ciliate Paramecium tetraurelia. Over the last four years, post-genomic data from proteome and transcriptome studies has been incorporated along with predicted orthologs in 33 species, annotations from the community and publications from the scientific literature. Available tools include BioMart for complex queries, GBrowse2 for genome browsing, the Apollo genome editor for expert curation of gene models, a Blast server, a motif finder, and a wiki for protocols, nomenclature guidelines and other documentation. In-house tools have been developed for ontology browsing and evaluation of off-target RNAi matches. Now ready for next-generation deep sequencing data and the genomes of other Paramecium species, this open-access resource is available at http://paramecium.cgm.cnrs-gif.fr.

  3. Deep RNA sequencing reveals hidden features and dynamics of early gene transcription in Paramecium bursaria chlorella virus 1.

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    Guillaume Blanc

    Full Text Available Paramecium bursaria chlorella virus 1 (PBCV-1 is the prototype of the genus Chlorovirus (family Phycodnaviridae that infects the unicellular, eukaryotic green alga Chlorella variabilis NC64A. The 331-kb PBCV-1 genome contains 416 major open reading frames. A mRNA-seq approach was used to analyze PBCV-1 transcriptomes at 6 progressive times during the first hour of infection. The alignment of 17 million reads to the PBCV-1 genome allowed the construction of single-base transcriptome maps. Significant transcription was detected for a subset of 50 viral genes as soon as 7 min after infection. By 20 min post infection (p.i., transcripts were detected for most PBCV-1 genes and transcript levels continued to increase globally up to 60 min p.i., at which time 41% or the poly (A+-containing RNAs in the infected cells mapped to the PBCV-1 genome. For some viral genes, the number of transcripts in the latter time points (20 to 60 min p.i. was much higher than that of the most highly expressed host genes. RNA-seq data revealed putative polyadenylation signal sequences in PBCV-1 genes that were identical to the polyadenylation signal AAUAAA of green algae. Several transcripts have an RNA fragment excised. However, the frequency of excision and the resulting putative shortened protein products suggest that most of these excision events have no functional role but are probably the result of the activity of misled splicesomes.

  4. Beta-adrenergic stimulation of phagocytosis in the unicellular eukaryote Paramecium aurelia.

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    Wyroba, E

    1989-08-01

    Bete-adrenergic agonists isoproterenol and norepinephrine enhanced phagocytosis in Paramecium. Stimulation was stereospecific, dose-dependent and inhibited by the beta-agonists propranolol and alprenolol. Phorbol ester and forskolin potentiated the stimulatory effect of catecholamines on Paramecium phagocytosis. The dansyl analogue of propranolol (DAPN) was used for fluorescent visualization of the beta-adrenergic receptor sites in Paramecium which have been found to be localized at the cell membrane and within the membrane of the nascent digestive vacuoles. The appearance of the characteristic fluorescent pattern has been blocked by 1-propranolol.

  5. Pharmacological attenuation of Paramecium fluid-phase endocytosis.

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    Wiejak, Jolanta; Surmacz, Liliana; Wyroba, Elzbieta

    2007-01-01

    Spectrophotometric quantification of fluid phase endocytosis in the presence of different pharmacological compounds was performed in the model unicellular eukaryote Paramecium. The kinetics of Lucifer Yellow Carbohydrazide (LY) uptake in cells exposed to forskolin and isoproterenol--known to stimulate phagocytosis in this cell--was analyzed. Reduction in both the rate of endocytosis and total accumulation of fluid phase marker was observed following the treatment. Forskolin diminished total LY accumulation by 11% and 21% after 5 min and 25 min of incubation, respectively, whereas the rate of uptake was lowered by 21% in comparison to control cells. The inhibitory effect ofisoproterenol was less pronounced than that of forskolin. The total accumulation of LY was decreased by 11% in 5 min as compared to the untreated cells and this effect was persistent upon further exposition to this reagent up to 25 min. To better understand these observations, the effect of inhibitors of PKA and cAMP phosphodiesterase on fluid phase uptake was tested. 3-isobutyl-1-methyl xanthine (IBMX) caused 12% decrease in LY accumulation after 5 min of incubation. In combination with isoproterenol or forskolin, IBMX enhanced their inhibitory effect on fluid endocytosis, which was lowered by 25% and 29%, respectively. The strongest inhibitory effect on fluid endocytosis was exerted by the 10 microM PKA inhibitor, which diminished endocytosis by 35% in 5 min. These results suggest that Paramecium fluid phase uptake may be regulated through activation of PKA, although the precise mechanism of this process has not yet been elucidated.

  6. Binding of concanavalin A by the cell membrane of a unicellular organism, Paramecium aurelia.

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    Wyroba, E

    1975-01-01

    As demonstrated by electron microscopy, Concanavalin A receptors exist on the cell membrane of Paramecium aurelia. The interpretation of the cytochemical detection of Con A binding is not very precise because of a slight, unspecific peroxidase adsorption.

  7. Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

    Energy Technology Data Exchange (ETDEWEB)

    Hooftman, R.N.

    1983-08-01

    The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of those that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

  8. Mutagenicity of fly ash samples in a test with the protozoan Paramecium tetraurelia. Onderzoek naar de mutageniteit van een aantal vliegasmonsters in een toets met het pantoffeldiertje Paramecium tetraurelia

    Energy Technology Data Exchange (ETDEWEB)

    Hooftman, R.N.

    1983-08-01

    The mutagenicity of fly ash derived from combustion of coal was investigated in a test with the protozoan Paramecium tetraurelia. This unicellular organism is able to ingest particles of the size of these that are ingested and removed by the alveolar macrophages in the lung of man and other animals: in Paramecium, as in the macrophage, ingestion is followed by intracellular extraction. Both ash from the electrostatic filter and stack-ash were mutagenic in Paramecium. The results showed similarities with and some differences from those obtained in the Ames test. There are indications that the test with Paramecium is a sensitive test for the mutagenicity of complex wastes.

  9. Stimulation of Paramecium phagocytosis by phorbol ester and forskolin.

    Science.gov (United States)

    Wyroba, E

    1987-09-01

    Phorbol ester (PMA) exerted a dose- and time- dependent stimulating effect on phagocytosis in axenic Paramecium aurelia. When cells were exposed to 200-800 nM PMA in the presence of latex beads, the phagocytic coefficient was enhanced 2.25 to 3.14 times, during 10 min of continuous treatment and then rapidly declined. A similar effect was observed when the cells were exposed to a forskolin treatment, which resulted in nearly a twofold increase in phagocytic activity after a 10 min pulse. Both PMA and forskolin strongly stimulated phagocytosis (i.e. fivefold and threefold, respectively) in cells in which such activity had been completely inhibited by pre-exposure to the beta-receptor antagonist 1-propranolol.

  10. Sex recombination, and reproductive fitness: an experimental study using Paramecium

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, D.

    1982-08-01

    The effect of sex and recombination on reproductive fitness are measured using five wild stocks of Paramecium primaurelia. Among the wild stocks there were highly significant differences in growth rates. No hybrid had as low a fitness as the least fit parental stock. Recombination produced genotypes of higher fitness than those of either parent only in the cross between the two stocks of lowest fitness. The increase in variance of fitness as a result of recombination was almost exclusively attributable to the generation lines with low fitness. The fitness consequences of sexuality and mate choice were stock specific; some individuals leaving the most descendants by inbreeding, others by outcrossing. For most crosses the short-term advantage of sex, if any, accrue from the fusion of different gametes (hybrid vigor) and not from recombination. Since the homozygous genotype with the highest fitnes left the most progeny by inbreeding (no recombination), the persistence of conjugation in P. primaurelia is paradoxical. (JMT)

  11. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    Energy Technology Data Exchange (ETDEWEB)

    Kozai, Naofumi, E-mail: kozai.naofumi@jaea.go.jp [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Ohnuki, Toshihiko [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, JAEA, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-10-15

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  12. Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium

    Directory of Open Access Journals (Sweden)

    Lynch Michael

    2010-05-01

    Full Text Available Abstract Background In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa remains a virtually unexplored issue. Results By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Conclusions Our observations 1 shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2 are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3 reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.

  13. The activity of parafusin is distinct from that of phosphoglucomutase in the unicellular eukaryote Paramecium.

    Science.gov (United States)

    Andersen, A P; Wyroba, E; Reichman, M; Zhao, H; Satir, B H

    1994-05-16

    In this paper we identified the presence of a Paramecium phosphoglucomutase enzymatic activity which is clearly distinct from that of parafusin-the exocytosis-related phosphoglycoprotein. Since the recently cloned parafusin showed homology to rabbit muscle phosphoglucomutase, we have designed a specific peptide parafusin antibody-generated to a region not present in any known sequenced phosphoglucomutases-to distinguish parafusin from the Paramecium phosphoglucomutase. Separation of these two proteins was obtained using liquid chromatography, enzymatic activity assay and immunoblotting analysis with the specific parafusin peptide antibody. Parafusin fractions incorporated [B35S]UDP-Glc but not [35S]Glc-1-P whereas Paramecium phosphoglucomutase fractions incorporated [35S]Glc-1-P but not [B35S]UDP-Glc. This indicates that these two proteins are separate entities exhibiting different properties and most likely distinct functions in the cell.

  14. Magnetic separation of algae

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  15. Developmentally programmed excision of internal DNA sequences in Paramecium aurelia.

    Science.gov (United States)

    Gratias, A; Bétermier, M

    2001-01-01

    The development of a new somatic nucleus (macronucleus) during sexual reproduction of the ciliate Paramecium aurelia involves reproducible chromosomal rearrangements that affect the entire germline genome. Macronuclear development can be induced experimentally, which makes P. aurelia an attractive model for the study of the mechanism and the regulation of DNA rearrangements. Two major types of rearrangements have been identified: the fragmentation of the germline chromosomes, followed by the formation of the new macronuclear chromosome ends in association with imprecise DNA elimination, and the precise excision of internal eliminated sequences (IESs). All IESs identified so far are short, A/T rich and non-coding elements. They are flanked by a direct repeat of a 5'-TA-3' dinucleotide, a single copy of which remains at the macronuclear junction after excision. The number of these single-copy sequences has been estimated to be around 60,000 per haploid genome. This review focuses on the current knowledge about the genetic and epigenetic determinants of IES elimination in P. aurelia, the analysis of excision products, and the tightly regulated timing of excision throughout macronuclear development. Several models for the molecular mechanism of IES excision will be discussed in relation to those proposed for DNA elimination in other ciliates.

  16. Correlation between thermotolerance and membrane properties in Paramecium aurelia.

    Science.gov (United States)

    Sasaki, Toshiaki; Konoha, Yoshimi; Toyoda, Taichi; Yasaka, Yuta; Przybos, Eva; Nakaoka, Yasuo

    2006-09-01

    The relationship between thermotolerance and membrane properties was studied by using a ciliated protozoan, Paramecium aurelia. P. aurelia is a complex of sibling species termed ;syngens' whose cell morphology appear similar on microscopic examination. From the comparison of tolerance to increasing temperature among 14 syngens of P. aurelia, we selected syngens 2 and 3 as low thermotolerant examples, and syngens 8 and 10 as high thermotolerant examples. The membrane resistance of high thermotolerant syngens measured by injection of a constant inward current was greater than that of low thermotolerant syngens. Membrane fluidity measurements of living cells using the fluorescent dye, 6-lauroyl-2-dimethylaminonaphtalene (laurdan) showed that the fluidity at the cultured temperature was decreased in high thermotolerant syngens compared to that of low thermotolerant syngens. However, when the temperature was increased to the killing temperature of each syngens, the fluidity was increased to almost the same level irrespective of syngen. Furthermore, analysis of fatty acids extracted from whole cells showed that the ratios of unsaturated to saturated fatty acids was smaller in high thermotolerant syngens than in low thermotolerant syngens. These results suggest that the thermotolerance of P. aurelia syngens is determined by the membrane fluidity which is related to the fatty acids composition.

  17. Ciliate Paramecium is a natural reservoir of Legionella pneumophila

    Science.gov (United States)

    Watanabe, Kenta; Nakao, Ryo; Fujishima, Masahiro; Tachibana, Masato; Shimizu, Takashi; Watarai, Masahisa

    2016-04-01

    Legionella pneumophila, the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment.

  18. Alteration of Paramecium candatum germinal nucleus morphology after UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Fokin, S.I. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

    1982-09-01

    A study was made on morphologic changes of micronucleus (Mi) after whole-body ultraviolet (UV) irradiation of paramecia as well as after local irradiation of this nucleus or the area of macronucleus (Ma). The whole-body irradiation of its Ma part leads to generative nucleus growth in sizes and chromatin structure change, which is expressed in occurence of large chromatin bodies. Aftereffects of local action on Mi for viable descendants are expressed in nucleus size transformation (usually in reduction), gaining ''comet-shaped'' form and probably in reduction of dna amount. Irradiation of Ma and total effect on cell cause Mi changes of reversible character. All morphologic changes of Mi after local ultraviolet irradiation are conserved in descendants and are not photoreactivated. Possible reasons for this phenomenon are discussed. The results obtained make it possible to speak about different mechanisms of action on Mi in the case of local and whole-body UV irradiation of cell. The effect of irradiated Ma on generative nucleus, but not direct damage of this nucleus is the reason for Mi morphologic reconstruction after whole-body action on paramecium.

  19. BIOLOGICAL EVALUATION OF CHLORELLA RESINOID VIA PARAMECIUM CAUDATUM

    Directory of Open Access Journals (Sweden)

    Mitishev, A.V.

    2016-04-01

    Full Text Available Цель: исследование действия резиноида хлореллы на культуру инфузорий Paramecium caudatum. Материалы и методы. Объектом исследования являлась культура клеток Paramecium caudatum.  Получение резиноида осуществляли согласно а. с.  1638157 (СССР. Результаты. Исследования показали, что после добавления резиноида хлореллы глубинная культура Paramecium caudatum в течение первых 3 часов, в основном, была расположена во всей толще, с преимуществом на поверхности среды. При концентрации резиноида хлореллы  1928 мкг/мл в конце эксперимента (через 24 часа скорость движения Paramecium caudatum по сравнению с контролем не изменилась, при этом наблюдался наименьший % гибели (15%. При других испытанных концентрациях резиноида в культуральной жидкости (241, 482, 989 мкг/мл выживаемость тест-культуры составила 50%.  Показано отсутствие в составе резиноида токсических веществ.

  20. Proliferation kinetics of paramecium tetraurelia in balloon-borne experiments

    Energy Technology Data Exchange (ETDEWEB)

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Rousseille, R.; Planel, H.

    1982-06-01

    Experiments were carried out to demonstrate the effect of cosmic radiation, at a balloon-flight ceiling of about 36,500 m (120,000 ft) on single-cell organism proliferation. Paramecium tetraurelia were placed in air-tight containers and maintained at 25 degrees +/- 0.1 degrees C. Cellular growth was determined by cell count, either after recovery or during the flight, by means of an automatic fixation device. Dosimetry was performed by a tissue equivalent proportional counter and was of about 0.5 mrad/h. Flight ceiling duration ranged from 48 min - 22 h. A secondary stimulating effect of growth rate, preceded by a temporary decrease, was observed after recovery. Because of the high bacterial concentration in the trans-Mediterranean flight culture medium, the temporary drop of the growth rate, due to the radiolysis products, disappears. Researchers consider that the stimulating effect can be the result of enzymatic intracellular scavenging of radiolysis products generated in the cell.

  1. Ciliate Paramecium is a natural reservoir of Legionella pneumophila

    Science.gov (United States)

    Watanabe, Kenta; Nakao, Ryo; Fujishima, Masahiro; Tachibana, Masato; Shimizu, Takashi; Watarai, Masahisa

    2016-01-01

    Legionella pneumophila, the causative agent of Legionnaires’ disease, replicates within alveolar macrophages and free-living amoebae. However, the lifestyle of L. pneumophila in the environment remains largely unknown. Here we established a novel natural host model of L. pneumophila endosymbiosis using the ciliate Paramecium caudatum. We also identified Legionella endosymbiosis-modulating factor A (LefA), which contributes to the change in life stage from endosymbiosis to host lysis, enabling escape to the environment. We isolated L. pneumophila strains from the environment, and they exhibited cytotoxicity toward P. caudatum and induced host lysis. Acidification of the Legionella-containing vacuole (LCV) was inhibited, and enlarged LCVs including numerous bacteria were observed in P. caudatum infected with L. pneumophila. An isogenic L. pneumophila lefA mutant exhibited decreased cytotoxicity toward P. caudatum and impaired the modification of LCVs, resulting in the establishment of endosymbiosis between them. Our results suggest that L. pneumophila may have a mechanism to switch their endosymbiosis in protistan hosts in the environment. PMID:27079173

  2. Evolutionary conservancy of the endocytic and trafficking machinery in the unicellular eukaryote Paramecium.

    Science.gov (United States)

    Surmacz, Liliana; Wiejak, Jolanta; Wyroba, Elzbieta

    2003-01-01

    Molecular search for the homologues of the mammalian proteins in the unicellular eukaryote Paramecium involved in endocytosis and membrane trafficking is discussed. We cloned and sequenced the gene fragments encoding the following components participating in endosome formation, sorting and maturation of the proprotein precursors, respectively, dynamin 2, Rab7 and furin. There is a proof that all these genes are expressed in this unicellular organism. The function of the identified immunoanalogues of the above described components of Paramecium endocytic machinery as well as a high degree of sequence homology to the respective human counterparts points to the evolutionary conservancy of these pathways.

  3. Effects of non-steroidal anti-inflammatory drugs on cyanobacteria and algae in laboratory strains and in natural algal assemblages.

    Science.gov (United States)

    Bácsi, István; B-Béres, Viktória; Kókai, Zsuzsanna; Gonda, Sándor; Novák, Zoltán; Nagy, Sándor Alex; Vasas, Gábor

    2016-05-01

    In recent years measurable concentrations of non-steroidal anti-inflammatory drugs (NSAIDs) have been shown in the aquatic environment as a result of increasing human consumption. Effects of five frequently used non-steroidal anti-inflammatory drugs (diclofenac, diflunisal, ibuprofen, mefenamic acid and piroxicam in 0.1 mg ml(-1) concentration) in batch cultures of cyanobacteria (Synechococcus elongatus, Microcystis aeruginosa, Cylindrospermopsis raciborskii), and eukaryotic algae (Desmodesmus communis, Haematococcus pluvialis, Cryptomonas ovata) were studied. Furthermore, the effects of the same concentrations of NSAIDs were investigated in natural algal assemblages in microcosms. According to the changes of chlorophyll-a content, unicellular cyanobacteria seemed to be more tolerant to NSAIDs than eukaryotic algae in laboratory experiments. Growth of eukaryotic algae was reduced by all drugs, the cryptomonad C. ovata was the most sensitive to NSAIDs, while the flagellated green alga H. pluvialis was more sensitive than the non-motile green alga D. communis. NSAID treatments had weaker impact in the natural assemblages dominated by cyanobacteria than in the ones dominated by eukaryotic algae, confirming the results of laboratory experiments. Diversity and number of functional groups did not change notably in cyanobacteria dominated assemblages, while they decreased significantly in eukaryotic algae dominated ones compared to controls. The results highlight that cyanobacteria (especially unicellular ones) are less sensitive to the studied, mostly hardly degradable NSAIDs, which suggest that their accumulation in water bodies may contribute to the expansion of cyanobacterial mass productions in appropriate environmental circumstances by pushing back eukaryotic algae. Thus, these contaminants require special attention during wastewater treatment and monitoring of surface waters.

  4. Recent data on the occurrence of species of the Paramecium aurelia complex in Europe.

    Science.gov (United States)

    Przyboś, Ewa

    2005-01-01

    Among 15 species of the Paramecium aurelia complex known world-wide, 10 have been found in Europe, namely: P. primaurelia, P. biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. sexaurelia, P. septaurelia, P. novaurelia, P. dodecaurelia, and P. tredecaurelia. Recent data on the frequency of occurrence of the species in Europe are given in the paper.

  5. Pdsg1 and Pdsg2, novel proteins involved in developmental genome remodelling in Paramecium.

    Directory of Open Access Journals (Sweden)

    Miroslav Arambasic

    Full Text Available The epigenetic influence of maternal cells on the development of their progeny has long been studied in various eukaryotes. Multicellular organisms usually provide their zygotes not only with nutrients but also with functional elements required for proper development, such as coding and non-coding RNAs. These maternally deposited RNAs exhibit a variety of functions, from regulating gene expression to assuring genome integrity. In ciliates, such as Paramecium these RNAs participate in the programming of large-scale genome reorganization during development, distinguishing germline-limited DNA, which is excised, from somatic-destined DNA. Only a handful of proteins playing roles in this process have been identified so far, including typical RNAi-derived factors such as Dicer-like and Piwi proteins. Here we report and characterize two novel proteins, Pdsg1 and Pdsg2 (Paramecium protein involved in Development of the Somatic Genome 1 and 2, involved in Paramecium genome reorganization. We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny. Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs and chromatin modification patterns during development. Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

  6. Paramecium aurelia species complex in the catchment area of the River Raba mountain course (the Carpathians).

    Science.gov (United States)

    Komala, Z

    2001-01-01

    In the water bodies of the Beskid Wyspowy Mts three species of the Paramecium aurelia complex have been found, i.e. P. biaurelia, P. tetraurelia and P. novaurelia. P. tetraurelia, which in Europe is a very rare species, was for the first time recorded in this region of the Carpathians.

  7. Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues

    Directory of Open Access Journals (Sweden)

    E Wyroba

    2009-08-01

    Full Text Available Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein and LAMP-2 (lysosomal membrane protein 2 as well as a7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2 in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100 000 x g of equal load were quantified by immunoblotting. LAMP-2 crossreacting polypeptide of ~106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The a7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILPrelated polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

  8. Phagosome maturation in unicellular eukaryote Paramecium: the presence of RILP, Rab7 and LAMP-2 homologues.

    Science.gov (United States)

    Wyroba, E; Surmacz, L; Osinska, M; Wiejak, J

    2007-01-01

    Phagosome maturation is a complex process enabling degradation of internalised particles. Our data obtained at the gene, protein and cellular level indicate that the set of components involved in this process and known up to now in mammalian cells is functioning in unicellular eukaryote. Rab7-interacting partners: homologues of its effector RILP (Rab-interacting lysosomal protein) and LAMP-2 (lysosomal membrane protein 2) as well as alpha7 subunit of the 26S proteasome were revealed in Paramecium phagolysosomal compartment. We identified the gene/transcript fragments encoding RILP-related proteins (RILP1 and RILP2) in Paramecium by PCR/RT-PCR and sequencing. The deduced amino acid sequences of RILP1 and RILP2 show 60.5% and 58.3% similarity, respectively, to the region involved in regulating of lysosomal morphology and dynein-dynactin recruitment of human RILP. RILP colocalised with Rab7 in Paramecium lysosomes and at phagolysosomal membrane during phagocytosis of both the latex beads and bacteria. In the same compartment LAMP-2 was present and its expression during latex internalisation was 2.5-fold higher than in the control when P2 protein fractions (100,000 x g) of equal load were quantified by immunoblotting. LAMP-2 cross-reacting polypeptide of approximately106 kDa was glycosylated as shown by fluorescent and Western analysis of the same blot preceded by PNGase F treatment. The alpha7 subunit of 26S proteasome was detected close to the phagosomal membrane in the small vesicles, in some of which it colocalised with Rab7. Immunoblotting confirmed presence of RILP-related polypeptide and a7 subunit of 26S proteasome in Paramecium protein fractions. These results suggest that Rab7, RILP and LAMP-2 may be involved in phagosome maturation in Paramecium.

  9. Alkaloids in Marine Algae

    OpenAIRE

    Ekrem Sezik; Aline Percot; Kasım Cemal Güven

    2010-01-01

    This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review...

  10. IDENTIFICATION OF PARAMECIUM BURSARIA SYNGENS THROUGH MOLECULAR MARKERS – COMPARATIVE ANALYSIS OF MITOCHONDRIAL CYTOCHROME C OXIDASE SUBUNIT I (COI

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    Patrycja Zagata

    2014-08-01

    Full Text Available The aim of this study is an identification of Paramecium bursaria syngens originating from different geographical locations and proving the correlation between distributions and belonging to any of five syngens. Ten strains of Paramecium bursaria belonging to five different syngens and strain of Paramecium multimicronucleatum were investigated using molecular marker — mitochondrial cytochrome c oxidase subunit I (COI. According to results, obtained in this study, using phylogenetic methods like Neighbor Joining (NJ and Maximum Likelihood (ML, relationship between analyzing strains through their clustering in clusters and correlation between strains belonging to any syngen and syngen’s distribution was confirmed. Phylograms constructed using NJ and ML methods revealed strains’ grouping in five clusters. Results which were obtained revealed usefulness of COI as a biomarker, which is important in identification of Paramecium bursaria syngens. This reports to a great potential of COI as a molecular marker and obtaining dependable results through combination of molecular methods with classical ones.

  11. Let them eat algae

    Energy Technology Data Exchange (ETDEWEB)

    Ciferri, O.

    1981-09-24

    The blue-green alga, Spirulina appears to be one of the candidates for the solution of the global problems of energy, food and chemical feedstock supplies. The harvesting of algae from Lake Texcoco, Mexico for the making of bread was noted in the 16th century by the Spanish and over 400 years later, dried biscuits made from algae were noted in Chad. Recent investigations have shown that the alga contains a very high proportion of protein - even higher than soya beans and is of high quality. A pilot plant covering 2 hectares for culturing Spirulina in a closed system is under construction in Italy. The polyethylene tubes will function as solar collectors and so extend the production season of the algae in more temperate regions.

  12. Algae Derived Biofuel

    Energy Technology Data Exchange (ETDEWEB)

    Jahan, Kauser [Rowan Univ., Glassboro, NJ (United States)

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  13. The mitochondrial genome sequence of the ciliate Paramecium caudatum reveals a shift in nucleotide composition and codon usage within the genus Paramecium

    Directory of Open Access Journals (Sweden)

    Berendonk Thomas U

    2011-05-01

    Full Text Available Abstract Background Despite the fact that the organization of the ciliate mitochondrial genome is exceptional, only few ciliate mitochondrial genomes have been sequenced until today. All ciliate mitochondrial genomes are linear. They are 40 kb to 47 kb long and contain some 50 tightly packed genes without introns. Earlier studies documented that the mitochondrial guanine + cytosine contents are very different between Paramecium tetraurelia and all studied Tetrahymena species. This raises the question of whether the high mitochondrial G+C content observed in P. tetraurelia is a characteristic property of Paramecium mtDNA, or whether it is an exception of the ciliate mitochondrial genomes known so far. To test this question, we determined the mitochondrial genome sequence of Paramecium caudatum and compared the gene content and sequence properties to the closely related P. tetraurelia. Results The guanine + cytosine content of the P. caudatum mitochondrial genome was significantly lower than that of P. tetraurelia (22.4% vs. 41.2%. This difference in the mitochondrial nucleotide composition was accompanied by significantly different codon usage patterns in both species, i.e. within P. caudatum clearly A/T ending codons dominated, whereas for P. tetraurelia the synonymous codons were more balanced with a higher number of G/C ending codons. Further analyses indicated that the nucleotide composition of most members of the genus Paramecium resembles that of P. caudatum and that the shift observed in P. tetraurelia is restricted to the P. aurelia species complex. Conclusions Surprisingly, the codon usage bias in the P. caudatum mitochondrial genome, exemplified by the effective number of codons, is more similar to the distantly related T. pyriformis and other single-celled eukaryotes such as Chlamydomonas, than to the closely related P. tetraurelia. These differences in base composition and codon usage bias were, however, not reflected in the amino

  14. Genetic differentiation of the mitochondrial cytochrome oxidase C subunit I gene in genus Paramecium (Protista, Ciliophora.

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    Full Text Available BACKGROUND: The mitochondrial cytochrome c oxidase subunit I (COI gene is being used increasingly for evaluating inter- and intra-specific genetic diversity of ciliated protists. However, very few studies focus on assessing genetic divergence of the COI gene within individuals and how its presence might affect species identification and population structure analyses. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the genetic variation of the COI gene in five Paramecium species for a total of 147 clones derived from 21 individuals and 7 populations. We identified a total of 90 haplotypes with several individuals carrying more than one haplotype. Parsimony network and phylogenetic tree analyses revealed that intra-individual diversity had no effect in species identification and only a minor effect on population structure. CONCLUSIONS: Our results suggest that the COI gene is a suitable marker for resolving inter- and intra-specific relationships of Paramecium spp.

  15. Alveolar system of Paramecium. I. Trapping polycationic dye as a result of membrane impairment.

    Science.gov (United States)

    Wyroba, E

    1981-01-01

    The function of Paramecium alveolar system underlying the cell membrane has been studied. Permeability and structure of cell membrane, alveolar membranes and alveoli following alpha-amylase, beta-amylase, phospholipase C and hyaluronidase treatment has been examined. It is demonstrated that droplets of polycationic dye, ruthenium red, have been trapped within the alveoli whereas the dye was also bound by the outer and inner alveolar membrane. This suggest the presence of anionic sites capable to bind cationic compounds within the alveoli. It may be concluded that the alveolar system in Paramecium is functioning as a barrier protecting the cell against the chemicals added from the outside when the cell membrane separating the cytoplasm from the medium is impaired.

  16. Optical Manipulation of Symbiotic Chlorella in Paramecium Bursaria Using a Fiber Axicon Microlens

    Science.gov (United States)

    Taguchi, K.; Hirota, S.; Nakayama, H.; Kunugihara, D.; Mihara, Y.

    2012-03-01

    In this paper, chemically etched axicon fiber was proposed for laser trapping of symbiotic chlorella from paramecium bursaria. We fabricated axicon micro lenses on a single-mode bare optical fiber by selective chemical etching technique. The laser beam from fiber axicon microlens was strongly focused and optical forces were sufficient to move a symbiotic chlorella. From experimental results, it was found that our proposed fiber axicon microlens was a promising tool for cell trapping without physical contact.

  17. Synthesis of chiral phosphonoacetamides and their toxic effects on paramecium sp

    Directory of Open Access Journals (Sweden)

    Samia Guezane Lakoud

    2015-02-01

    Full Text Available Three chiral phosphonoacetamides were prepared by an alternative method . For this purpose, 2-(diethoxyphosphorylacetic acid was prepared from ethyl 2-bromoacetate by treatment of P(OEt 3 followed by saponification of the ester with K 2CO 3. BOP activated amidation of the 2-(diethoxyphosphorylacetic acid with (S-amino acids gave the corresponding phosphonoaceteamides. Growth inhibition of two phosphonoacetamides on Paramecium sp. were studied.

  18. Passage of selected heavy metals from Sphaerotilus (bacteria: Chlamydobacteriales) to Paramecium caudatum (protozoa: Ciliata)

    Energy Technology Data Exchange (ETDEWEB)

    Mansouri-Aliabadi, M.; Sharp, R.E.

    1985-01-01

    Sphaerotilus, a bacterium occurring in polluted waters, was found to take up Zn, Pb, Ni and Mn. Metal-containing cultures of this bacterium were employed to feed the protozoan Paramecium caudatum, and analytical results revealed the accumulation of Zn, Pb and Ni. Since Sphaerotilus wa the only food source for paramecia during this study, the results indicate that trace amounts of metal were passed from bacteria to protozoa in a predator-prey relationship.

  19. Comparative study of proliferation kinetics of paramecium tetraurelia aboard a satellite and a balloon flight

    Energy Technology Data Exchange (ETDEWEB)

    Tixador, R.; Richoilley, G.; Gasset, G.; Planel, H. (Faculte de Medecine, Toulouse-Purpan (France))

    1982-05-17

    A possible effect of cosmic rays on cell proliferation was investigated in cultures of Paramecium tetraurelia during a stratospheric balloon flight, with the techniques already used for the CYTOS experiments, performed aboard the orbital station Salyut 6. The results show that the stimulating effect of space on cell proliferation, reported in the CYTOS experiments, also occurs in the balloon flight. The respective roles of cosmic rays and weightlesness in the biological responses are discussed.

  20. Gene expression in a paleopolyploid: a transcriptome resource for the ciliate Paramecium tetraurelia

    Directory of Open Access Journals (Sweden)

    Kapusta Aurélie

    2010-10-01

    Full Text Available Abstract Background The genome of Paramecium tetraurelia, a unicellular model that belongs to the ciliate phylum, has been shaped by at least 3 successive whole genome duplications (WGD. These dramatic events, which have also been documented in plants, animals and fungi, are resolved over evolutionary time by the loss of one duplicate for the majority of genes. Thanks to a low rate of large scale genome rearrangement in Paramecium, an unprecedented large number of gene duplicates of different ages have been identified, making this organism an outstanding model to investigate the evolutionary consequences of polyploidization. The most recent WGD, with 51% of pre-duplication genes still in 2 copies, provides a snapshot of a phase of rapid gene loss that is not accessible in more ancient polyploids such as yeast. Results We designed a custom oligonucleotide microarray platform for P. tetraurelia genome-wide expression profiling and used the platform to measure gene expression during 1 the sexual cycle of autogamy, 2 growth of new cilia in response to deciliation and 3 biogenesis of secretory granules after massive exocytosis. Genes that are differentially expressed during these time course experiments have expression patterns consistent with a very low rate of subfunctionalization (partition of ancestral functions between duplicated genes in particular since the most recent polyploidization event. Conclusions A public transcriptome resource is now available for Paramecium tetraurelia. The resource has been integrated into the ParameciumDB model organism database, providing searchable access to the data. The microarray platform, freely available through NimbleGen Systems, provides a robust, cost-effective approach for genome-wide expression profiling in P. tetraurelia. The expression data support previous studies showing that at short evolutionary times after a whole genome duplication, gene dosage balance constraints and not functional change are

  1. Enhanced membrane fluorescence of CDC-labelled paramecium subsequent to removal of surface components.

    Science.gov (United States)

    Wyroba, E; Bottiroli, G; Giordano, P

    1983-01-01

    Cytofluorimetric analysis of cycloheptaamylose-dansyl chloride (CDC) labelled Paramecium indicates that after mild trypsin removal of surface components the localization of CDC on the outer surface of living cells was not modified by the treatment. After such treatment the intensity of fluorescence emission was found about 3-fold higher in treated single cell than in the untreated one. These findings indicate that CDC labelling can be used to follow alteration occurred on the membrane of the living cell prior to labelling.

  2. Effect of novel phosphoramidate on growth and respiratory metabolism of Paramecium aurelia.

    Science.gov (United States)

    Houneida, Benbouzid; Berrebah, H; Berredjem, M; Djebar, M R

    2012-01-01

    The continuous increase in the number of new chemicals as well as the discharges of solid and liquid wastes triggered the need for simple and inexpensive bioassays for routine testing. In recent years, there has been increasing development of methods (particularly rapid tests) for testing environmental samples. This paper describes the quick toxic evaluation of a novel synthetic compound: Phosphoramidate derivative B at different concentrations (2, 4 and 8 μM) for 72 h on Paramecium aurelia. We showed that B concentrations affect the growth of Paramecium in concentration- dependent manner; also it decreases the growth rate and increases response percentage in concentration- dependent manner. The value of LC50 obtained for these protozoa was estimated at 4.9693 μM after 24 hours of exposure. The respiratory metabolism of protozoan is perturbed at three concentrations, noting that the oxygen consumption was significantly increased at high concentrations after 18 hours of exposure. The results indicate that the Paramecium toxicity assay could be used as a complementary system to rapidly elucidate the cytotoxic potential of insecticides. The major advantages associated with these tests are: inexpensive, simple, rapid and seem to be attractive alternatives to conventional bioassays.

  3. Genetic and epigenetic factors affecting meiosis induction in eukaryotes revealed in paramecium research.

    Science.gov (United States)

    Prajer, Małgorzata

    2008-01-01

    This review presents studies of the induction of meiosis undertaken on the ciliate Paramecium, a unicellular model eukaryotic organism. Meiosis in Paramecium, preceding the process of fertilization, appears in starved cells after passing a defined number of divisions (cell generations), starting from the last fertilization. Investigations were performed on clones of cells entering autogamy, a self-fertilization process. Genetic as well as epigenetic factors, i.e. endo- and exogenous factors, affecting the induction ofmeiosis and changing the duration of the interautogamous interval (IAI), were analyzed. The results show that: (1) Meiosis induction is controlled genetically by the somatic macronucleus. However, besides the nuclear factors, the cytoplasmic protein immaturin also affects this process (Haga & Hiwatashi 1981); (2) Epigenetic factors, such as non-genetically disturbed cytoskeleton structures and changes in the cell architecture observed in doublet Paramecium cells, exert internal mechanical stress (Ingber 2003), which constitutes the endogenous impulse accelerating meiosis; (3) Mild osmotic stress, acting as an exogenous factor, can initiate the specific MAP kinases signaling pathway resulting in earlier meiosis induction, as in other unicellular eukaryotes (Seet & Pawson 2004).

  4. Uptake and distribution of haematoporphyrin derivative in the unicellular eukaryote Paramecium.

    Science.gov (United States)

    Croce, A C; Wyroba, E; Bottiroli, G

    1990-08-01

    Haematoporphyrin derivative (HpD) uptake, intracellular distribution and turnover were examined in a free-living protozoan cell, Paramecium aurelia, which had been demonstrated to internalize lipoproteins. A 10 min incubation in HpD completed with low-density lipoprotein (LDL) resulted in the appearance of distinct red-fluorescing vesicles, together with a diffuse fluorescence of the cytoplasm. Fluorescein labelling of LDL demonstrated the intracellular localization of HpD and LDL within the same vesicles. Pretreatment of Paramecium with the β-adrenergic antagonist l-propranolol, which blocked its phagocytotic activity, resulted in an absence of red-fluorescing vesicles; thus these were proved to be endosomes. Fluorescence emission recorded in the endosomes was characterized by a band at about 660-670 nm which was attributed to the partially unfolded oligomers; this emission was present during maintenance of the cells in drug-free culture medium for up to 120 min. Propranolol-pretreated cells exhibited only a diffuse cytoplasmic fluorescence characterized by an emission band at 630 nm, which was attributed to the monomers; this disappeared rapidly on washing. These results suggest the following: (i) HpD monomers enter Paramecium via transmembrane influx and/or fluid phase uptake; (ii) HpD oligomers are mainly internalized via receptor-mediated endocytosis; (iii) the extent of the endocytotic process is increased when HpD is completed with LDL; (iv) after internalization, aggregate species undergo a disaggregating process which accounts for the persistence of the intracellular fluorescence.

  5. Immunoanalogue of vertebrate beta-adrenergic receptor in the unicellular eukaryote Paramecium.

    Science.gov (United States)

    Wiejak, Jolanta; Surmacz, Liliana; Wyroba, Elzbieta

    2002-01-01

    Cell fractionation, SDS-PAGE, quantitative Western blot, confocal immunolocalization and immunogold labelling were performed to find an interpretation of the physiological response of the unicellular eukaryote Paramecium to beta-adrenergic ligands. The 69 kDa polypeptide separated by SDS-PAGE in S2 and P2 Paramecium subcellular fractions cross-reacted with antibody directed against human beta2-adrenergic receptor. This was detected by Western blotting followed by chemiluminescent detection. Quantitative image analysis showed that beta-selective adrenergic agonist (-)-isoproterenol--previously shown to enhance phagocytic activity--evoked redistribution of the adrenergic receptor analogue from membraneous (P2) to cytosolic (S2) fraction. The relative increase in immunoreactive band intensity in S2 reached 80% and was paralleled by a 59% decrease in P2 fraction. Confocal immunofluorescence revealed beta2-adrenergic receptor sites on the cell surface and at the ridge of the cytopharynx--where nascent phagosomes are formed. This localization was confirmed by immunoelectron microscopy. These results indicate that the 69 kDa Paramecium polypeptide immunorelated to vertebrate beta2-adrenergic receptor appeared in this evolutionary ancient cell as a nutrient receptor.

  6. Wastewater treatment with algae

    Energy Technology Data Exchange (ETDEWEB)

    Wong Yukshan [Hong Kong Univ. of Science and Technology, Kowloon (China). Research Centre; Tam, N.F.Y. [eds.] [City Univ. of Hong Kong, Kowloon (China). Dept. of Biology and Chemistry

    1998-05-01

    Immobilized algal technology for wastewater treatment purposes. Removal of copper by free and immobilized microalga, Chlorella vulgaris. Biosorption of heavy metals by microalgae in batch and continuous systems. Microalgal removal of organic and inorganic metal species from aqueous solution. Bioaccumulation and biotransformation of arsenic, antimony and bismuth compounds by freshwater algae. Metal ion binding by biomass derived from nonliving algae, lichens, water hyacinth root and spagnum moss. Metal resistance and accumulation in cyanobacteria. (orig.)

  7. Delimiting Species Boundaries within a Paraphyletic Species Complex: Insights from Morphological, Genetic, and Molecular Data on Paramecium sonneborni (Paramecium aurelia species complex, Ciliophora, Protozoa).

    Science.gov (United States)

    Przyboś, Ewa; Tarcz, Sebastian; Rautian, Maria; Sawka, Natalia

    2015-09-01

    The demarcation of boundaries between protist species is often problematic because of the absence of a uniform species definition, the abundance of cryptic diversity, and the occurrence of convergent morphology. The ciliates belonging to the Paramecium aurelia complex, consisting of 15 species, are a good model for such systematic and evolutionary studies. One member of the complex is P. sonneborni, previously known only from one stand in Texas (USA), but recently found in two new sampling sites in Cyprus (creeks running to Salt Lake and Oroklini Lake near Larnaca). The studied Paramecium sonneborni strains (from the USA and Cyprus) reveal low viability in the F1 and F2 generations of interstrain hybrids and may be an example of ongoing allopatric speciation. Despite its molecular distinctiveness, we postulate that P. sonneborni should remain in the P. aurelia complex, making it a paraphyletic taxon. Morphological studies have revealed that some features of the nuclear apparatus of P. sonneborni correspond to the P. aurelia spp. complex, while others are similar to P. jenningsi and P. schewiakoffi. The observed discordance indicates rapid splitting of the P. aurelia-P. jenningsi-P. schewiakoffi group, in which genetic, morphological, and molecular boundaries between species are not congruent.

  8. Hierarchical paramecium-like hollow and solid Au/Pt bimetallic nanostructures constructed using goethite as template

    Energy Technology Data Exchange (ETDEWEB)

    Liu Wei; Repo, Eveliina; Sillanpaeae, Mika [Laboratory of Applied Environmental Chemistry, University of Eastern Finland, Patteristonkatu 1, FI-50100 Mikkeli (Finland); Heikkilae, Mikko; Leskelae, Markku, E-mail: weiliuzk@yahoo.cn, E-mail: mika.sillanpaa@uef.fi [Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, PO Box 55 (A.I. Virtasen aukio 1), FI-00014, Helsinki (Finland)

    2010-10-01

    Novel hollow and solid paramecium-like hierarchical Au/Pt bimetallic nanostructures were constructed using goethite as template via a seed-mediated growth method. Transmission electron microscopy (TEM), {xi}-potential measurement, UV-vis spectroscopy, energy dispersive x-ray spectroscopy (EDS), ICP-AES measurement, x-ray powder diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) were utilized to systematically characterize the bimetallic nanostructures. It is found that the core structure of the paramecium-like bimetallic nanomaterial is closely related to reducing agent. When ascorbic acid is used as reducing agent, goethite serves as in situ sacrificed template and hollow paramecium-like bimetallic structure is obtained. When NH{sub 2}OH{center_dot}HCl is used, solid nanostructure with preserved goethite core is produced. Heating the reaction solution is necessary to obtain the paramecium-like morphology with rough interconnected Pt cilia shell. The thickness of Pt cilia layer can be controlled by adjusting the molar ratio of H{sub 2}PtCl{sub 6} to Au nanoseeds. The overgrowth of the rough Pt cilia is proposed to be via an autocatalytic and three-dimensional heterogeneous nucleation process first through flower-like morphology. Both the hollow and solid hierarchical paramecium-like Au/Pt bimetallic nanostructures show good catalytic activities.

  9. Algae fuels : a tantalizing alternative

    Energy Technology Data Exchange (ETDEWEB)

    Granson, E.

    2010-11-15

    This article surveyed the current state of research and development in the area of algae use as a basis for fuel and as a feedstock for the chemical industry. The constraints inhibiting the commercialization of algae-related processes were discussed and a brief overview of the history of algae research was presented. Interest in algae research has ebbed and flowed in conjunction with economic and social concerns. It is unknown whether algae can be grown on a scale and cost that is commercially viable. A bench-scale algae cultivation system involving photobioreactors was described. Algae are increasingly being used in treating wastewater from industrial processes, as algae can reduce ammonia and phosphate loads in effluent. Exhaust carbon dioxide is being used to feed algae crops. Advances are needed to make turning algae oil into fuel cost effective. A bench-stage process for extracting algae oil from water for biofuel conversion was described. The process results in easier-to-dry biomass without using chemical solvents or centrifuges. Algae biomass is also being explored for used as a polymer feedstock. Algae can be grown anywhere there is sun, but the challenge is in developing a large enough supply of algae biomass. Second generation algae plastic products will be more complex and may involve the creation of a monomer out of algae itself, which could make algae competitive with oil in the plastics industry. Skeptics doubt that algae processes can be commercialized, but some within the industry believe that algae biomass will eventually work within the norms of industrial processes. 5 figs.

  10. Calcium-release channels in paramecium. Genomic expansion, differential positioning and partial transcriptional elimination.

    Directory of Open Access Journals (Sweden)

    Eva-Maria Ladenburger

    Full Text Available The release of Ca²⁺ from internal stores is a major source of signal Ca²⁺ in almost all cell types. The internal Ca²⁺ pools are activated via two main families of intracellular Ca²⁺-release channels, the ryanodine and the inositol 1,4,5-trisphosphate (InsP₃ receptors. Among multicellular organisms these channel types are ubiquitous, whereas in most unicellular eukaryotes the identification of orthologs is impaired probably due to evolutionary sequence divergence. However, the ciliated protozoan Paramecium allowed us to prognosticate six groups, with a total of 34 genes, encoding proteins with characteristics typical of InsP₃ and ryanodine receptors by BLAST search of the Paramecium database. We here report that these Ca²⁺-release channels may display all or only some of the characteristics of canonical InsP₃ and ryanodine receptors. In all cases, prediction methods indicate the presence of six trans-membrane regions in the C-terminal domains, thus corresponding to canonical InsP₃ receptors, while a sequence homologous to the InsP₃-binding domain is present only in some types. Only two types have been analyzed in detail previously. We now show, by using antibodies and eventually by green fluorescent protein labeling, that the members of all six groups localize to distinct organelles known to participate in vesicle trafficking and, thus, may provide Ca²⁺ for local membrane-membrane interactions. Whole genome duplication can explain radiation within the six groups. Comparative and evolutionary evaluation suggests derivation from a common ancestor of canonical InsP₃ and ryanodine receptors. With one group we could ascertain, to our knowledge for the first time, aberrant splicing in one thoroughly analyzed Paramecium gene. This yields truncated forms and, thus, may indicate a way to pseudogene formation. No comparable analysis is available for any other, free-living or parasitic/pathogenic protozoan.

  11. Cytochrome b sequence data suggest rapid speciation within the Paramecium aurelia species complex.

    Science.gov (United States)

    Barth, Dana; Przyboś, Ewa; Fokin, Sergei I; Schlegel, Martin; Berendonk, Thomas U

    2008-11-01

    We investigated mitochondrial Cytochrome b sequences from all 15 members of the enigmatic Paramecium aurelia species complex (Ciliophora). The analysis revealed high genetic distances between the different P. aurelia species (6.1-19.8%) and a largely unresolved, star-like phylogenetic tree. This result strongly supports a rapid radiation in the evolutionary history of this species complex and it correlates well with the hypothesis that the extant species diversity may have originated from the neutral consequences of a whole genome duplication in the common ancestor of P. aurelia.

  12. The ciliate Paramecium shows higher motility in non-uniform chemical landscapes.

    Directory of Open Access Journals (Sweden)

    Carl Giuffre

    Full Text Available We study the motility behavior of the unicellular protozoan Paramecium tetraurelia in a microfluidic device that can be prepared with a landscape of attracting or repelling chemicals. We investigate the spatial distribution of the positions of the individuals at different time points with methods from spatial statistics and Poisson random point fields. This makes quantitative the informal notion of "uniform distribution" (or lack thereof. Our device is characterized by the absence of large systematic biases due to gravitation and fluid flow. It has the potential to be applied to the study of other aquatic chemosensitive organisms as well. This may result in better diagnostic devices for environmental pollutants.

  13. The Gravikinetic Response of Paramecium is Based on Orientation-Dependent Mechanotransduction

    Science.gov (United States)

    Gebauer, Manuel; Watzke, Daniela; Machemer, Hans

    Paramecium generates persistent shifts of the membrane potential of a few millivolts depending on its orientation with respect to the gravity vector. The resulting potential-induced modulation of the speed of propulsion is called gravikinesis because it acts to neutralize, fully or in part, sedimentation. Gravisensitivity is maximal at neutral orientation, i.e., in horizontally swimming cells, when the gravitational force per unit membrane area is at minimum. Stimulus-response relationships and energetic considerations show that sensing of the gravity vector by a nonspecialized, single-cell organism ranks among the most sensitive mechanoreceptors known in nature.

  14. Release of Paramecium immobilization antigen to the non-nutrient medium.

    Science.gov (United States)

    Wyroba, E

    1980-01-01

    The instability of Paramecium aurelia surface components has been shown: after 60 min incubation of dense cell suspension ((1-2 . 10(6) cells per ml) in Tris-Ca buffer at 4 degrees C or 23 degrees C the surface coat was partially stripped off and the proteins were released to the medium. The electrophoretic analysis of the released proteins shows one major band of mol. wt. 280,000--300,000 and some minor bands. The major released protein is the immobilization antigen as proved using immunodiffusion test and antibody precipitation technique.

  15. Studies on the surface coat of Paramecium aurelia. II. Relationship to the immobilization antigen.

    Science.gov (United States)

    Wyroba, E

    1977-07-11

    Correlations between the presence of surface coat and immobilization antigen of Paramecium tetraurelia were studied. Supravital, partial removal of the surface coat resulted in accelerated response of monobacterially and axenically grown cells to the homologous antiserum. Ciliates pretreated with trypsin or pronase (0.5 mg/ml for 45 min at 0-4 degrees C) were immobilized approximately twice as fast as untreated control cells. The probable localization of at least part, of the immobilization antigen within the surface coat of P. tetraurelia is discussed.

  16. The ciliate Paramecium shows higher motility in non-uniform chemical landscapes.

    Science.gov (United States)

    Giuffre, Carl; Hinow, Peter; Vogel, Ryan; Ahmed, Tanvir; Stocker, Roman; Consi, Thomas R; Strickler, J Rudi

    2011-04-11

    We study the motility behavior of the unicellular protozoan Paramecium tetraurelia in a microfluidic device that can be prepared with a landscape of attracting or repelling chemicals. We investigate the spatial distribution of the positions of the individuals at different time points with methods from spatial statistics and Poisson random point fields. This makes quantitative the informal notion of "uniform distribution" (or lack thereof). Our device is characterized by the absence of large systematic biases due to gravitation and fluid flow. It has the potential to be applied to the study of other aquatic chemosensitive organisms as well. This may result in better diagnostic devices for environmental pollutants.

  17. New stands of species of the Paramecium aurelia complex (Ciliophora, Protozoa) in the Mediterranean region (Italy, Greece, Morocco).

    Science.gov (United States)

    Przyboś, Ewa; Rautian, Maria

    2012-01-01

    New stands of species of the Paramecium aurelia complex are presented in the paper, P. primaurelia recorded in Italy (Pisa) and in Morocco (Marrakesh), P. biaurelia in Italy (Calabria), P. triaurelia in Morocco (Ifrane), P. pentaurelia in Greece (Kastorya), and P. dodecaurelia in Italy (Padua).

  18. Paramecium tetraurelia pre-screen for hazardous chemicals: a rapid detector system for health hazards. 1977-1983 report

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Sonneborn, J.

    1983-01-01

    The purpose was to develop and validate a new eukaryotic bioassay system applicable to rapid identification of environmental toxins, mutagens, and carcinogens. The ability of Paramecium to detect potential health hazards, associated with complex environmental mixtures, was demonstrated in association with the finest coal fly ash particles and aqueous waste streams from both oil shale and coal gasification developing technologies. In Paramecium, the cytotoxicity of an agent was determined by altering the survival and/or growth rate of single cells in test agents. Genotoxicity was assayed by a two-tiered approach, utilizing both the Paramecium system and the more established Ames Salmonella assay for mutagen/carcinogen detection. An agent was considered genotoxic in Paramwecium if altered phenotypes were induced in the fertilization progeny of treated parent cells. Since others had shown a significant correlation between agents which were photodynamically active in Paramecium and carcinogenic in mammals, the photodynamic activity versus carcinogenicity of agents was reviewed. Photodynamically active compounds are defined by the immobilization of cells when exposed to both the test agent and black light; neither the agent alone nor light alone affects swimming activity.

  19. Metabolic engineering of Saccharomyces cerevisiae for production of eicosapentaenoic acid, using a novel δ5-desaturase from Paramecium tetraurelia

    DEFF Research Database (Denmark)

    de Andrade Pereira Tavares, Sabina; Grotkjær, Thomas; Obsen, Thomas;

    2011-01-01

    protozoan Paramecium tetraurelia and from the microalgae Ostreococcus tauri and Ostreococcus lucimarinus were identified via a BLAST search, and their substrate preferences and desaturation efficiencies were assayed in a yeast strain producing the ω6 and ω3 fatty acid substrates for Δ5-desaturation. The Δ5...

  20. Effects of pond partition on characteristics of algae and water quality in pond located at high latitudes; Anteichi wo secchishita kanreichiike no suishitsu henka to sorui tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Li, J. [Yamato Setsubi Construction Co. Ltd., Gunma (Japan); Kuroda, M. [Gunma University, Gunma (Japan). Faculty of Engineering; Wang, B. [Harbin Architectural and Civil Engineering Institute, Harbin (China). Water Pollution Control Research Center

    1995-10-10

    Characteristics of algae and water quality were studied at a pond located in high latitudes. Domestic and industrial wastewaters discharged are treated through different type stabilization ponds made by enclosing a part of the pond to remove BOD{sub 5}, COD{sub cr} and nutrients. Effects of the pond partition on the dominance species of algae and water quality were studied. During the cold term (-20{degree}C - -5{degree}C), Cryptomonas, Chlamydomonas and Euglena were dominance species in the pond. While Euglena, which may be grown by uptaking organic material was the dominance one in the stabilization pond, and its population increased in falling temperature. It plays an important role for removal of BOD{sub 5} and COD{sub cr}. On the other hand, during the warm term (15{degree}C - 30{degree}C), dominance species were Cyclotella, Chlorella and Microcystis in the pond and Scenedesmus obliqnus in facultative ponds of the stabilization ponds. Microcystis and Scenedesmus obliqnus would uptake NH4{sup +}-N truly. Removal of NH4{sup +}-N and PO4{sup 3-}-P depends on the concentration of Chl.a. The relationship between NH4{sup +}-N and PO4{sup 3-}-P removal and the concentrations of Chl.a was obtained. 11 refs., 8 figs., 3 tabs.

  1. New stands of species of the Paramecium aurelia complex in Africa and Europe.

    Science.gov (United States)

    Rautian, Maria; Przyboś, Ewa; Surmacz, Marta; Lebedeva, Natalia

    2014-01-01

    The relevance of geographical distribution and the roles of dispersal and spatial isolation during the speciation of microorganisms are nowadays of great interest. The Paramecium aurelia species complex is a perfect model system to explore these questions given its long history as a study subject and broad distribution. However, the world-wide distribution of the Paramecium aurelia complex (Ciliophora, Protista) still needs study, e.g., sampling in the southern hemisphere has been quite limited, while Europe has been investigated for years, with the majority of aurelia species isolated from here. Recently, new stands of species of the P. aurelia complex were found in southern Europe (Malta, Bulgaria, Cyprus) and in the Czech Republic (P. primaurelia, P. triaurelia, P. octaurelia). In Africa (Republic of South Africa), new stands of P. primaurelia, P. triaurelia, and P. octaurelia were found. Interestingly, the rare species P. triaurelia, and P. octaurelia were found to co-occur both in South Africa (SA 13) and the Czech Republic (CKV 8). Newly established strains were identified to species by crossing with the test strains (the reference strains for the particular species).

  2. New Stands of Species of the Paramecium aurelia Complex in Yakutia, Russia.

    Science.gov (United States)

    Rautian, Maria; Przyboś, Ewa; Beliavskaia, Alexandra

    2015-01-01

    Paramecium is one of the most studied genera among ciliates. In particular, it is a model organism for investigation of the sibling species problem (also known as the cryptic species problem), spatial distribution, and its role in speciation. The global distribution of Paramecium species and of sibling species belonging to the P. aurelia species complex (Ciliophora, Protista) still need study, e.g. sampling in some territories has been quite limited, while Europe has been investigated for years with the majority of the P. aurelia species isolated from here. The large territory of Yakutia (republic Sakha in the Russian Federation), known for its climate extremes and continuous permafrost that extended over several glacial and interglacial cycles of the Pleistocene, has not been studied before. In the present study we collected paramecia in the central part of Yakutia. Newly established strains were identified to species according to morphology and, in case of the P. aurelia complex, by crossing with the test strains (the reference strains for the particular species). New stands of P. primaurelia, P. biaurelia and P. novaurelia were described from the territory of Yakutia.

  3. Dynamin- and clathrin-dependent endocytic pathway in unicellular eukaryote Paramecium.

    Science.gov (United States)

    Wiejak, Jolanta; Surmacz, Liliana; Wyroba, Elzbieta

    2004-10-01

    The first evidence of dynamin presence and its colocalization with clathrin in the compartment involved in Paramecium receptor-mediated endocytosis is presented. We identified dynamin by cloning, Western blotting, and immunodetection in confocal and electron microscopy. The partial genes, which we have designated ParDyn1 and ParDyn2, are 1091 bp long, 90% identical to one another and encode the N-terminal and middle domains of Paramecium dynamin isoform 1 and isoform 2. The deduced amino acid sequences contain all three guanosine 5'-triphosphate (GTP)-binding motifs and show 67% homology to mammalian dynamins. Antibodies generated against the cloned GTPase domain revealed dynamin association with endosomes containing transferrin, the marker of receptor-mediated endocytosis. In Western blotting a strong immunoreactive polypeptide of approximately 116 kDa, which seems to be phosphorylated, was accompanied by a faint one of approximately 90 kDa in cytosolic fraction (S2). Dynamin level was correlated with internalization of transferrin and it was significantly decreased upon inhibition of this process. Immunogold labeling in electron microscopy revealed colocalization of dynamin and clathrin in coated pits and endocytic vesicles. Moreover, the polypeptide cross-reaction with 2 different antibodies against mammalian clathrin was identified by immunoblotting. These results indicate that dynamin- and clathrin-dependent pathway exists in this evolutionary ancient cell.

  4. Alterations in the protein pattern of subcellular fractions isolated from Paramecium cells suppressed in phagocytosis.

    Science.gov (United States)

    Surmacz, L; Wiejak, J; Wyroba, E

    2001-01-01

    SDS-PAGE and quantitative densitometric analysis revealed alterations in the protein pattern of subcellular fractions (100,000 x g) isolated from Paramecium aurelia (299s axenic) cells suppressed in phagocytosis as compared with the control. Two different agents were used to block phagocytosis: the beta-adrenergic antagonist-1-propranolol (200 microM) and inhibitor of calmodulin-dependent processes--trifluoperazine (20 microM). More than 40 polypeptides were identified in the cytosolic (soluble) fractions S1 and S2. A considerable decrease in band intensity was found for three polypeptides: by 60% for 87 kDa band, 52% for 75 kDa and 37% for 42 kDa in comparison to the control, when S2 fractions from propranolol-treated cells of equal load were quantified. TFP treatment evoked only a small decrease in the intensity of the same bands: 9%, 10% and 6%, respectively. The 42 kDa band was identified by Western blot analysis and chemiluminiscent detection to be actin. This result suggests that actin may be a primary target of pharmacological agents used in this study to inhibit Paramecium phagocytic activity.

  5. Insights into three whole-genome duplications gleaned from the Paramecium caudatum genome sequence.

    Science.gov (United States)

    McGrath, Casey L; Gout, Jean-Francois; Doak, Thomas G; Yanagi, Akira; Lynch, Michael

    2014-08-01

    Paramecium has long been a model eukaryote. The sequence of the Paramecium tetraurelia genome reveals a history of three successive whole-genome duplications (WGDs), and the sequences of P. biaurelia and P. sexaurelia suggest that these WGDs are shared by all members of the aurelia species complex. Here, we present the genome sequence of P. caudatum, a species closely related to the P. aurelia species group. P. caudatum shares only the most ancient of the three WGDs with the aurelia complex. We found that P. caudatum maintains twice as many paralogs from this early event as the P. aurelia species, suggesting that post-WGD gene retention is influenced by subsequent WGDs and supporting the importance of selection for dosage in gene retention. The availability of P. caudatum as an outgroup allows an expanded analysis of the aurelia intermediate and recent WGD events. Both the Guanine+Cytosine (GC) content and the expression level of preduplication genes are significant predictors of duplicate retention. We find widespread asymmetrical evolution among aurelia paralogs, which is likely caused by gradual pseudogenization rather than by neofunctionalization. Finally, cases of divergent resolution of intermediate WGD duplicates between aurelia species implicate this process acts as an ongoing reinforcement mechanism of reproductive isolation long after a WGD event.

  6. A forward genetic screen reveals essential and non-essential RNAi factors in Paramecium tetraurelia.

    Science.gov (United States)

    Marker, Simone; Carradec, Quentin; Tanty, Véronique; Arnaiz, Olivier; Meyer, Eric

    2014-06-01

    In most eukaryotes, small RNA-mediated gene silencing pathways form complex interacting networks. In the ciliate Paramecium tetraurelia, at least two RNA interference (RNAi) mechanisms coexist, involving distinct but overlapping sets of protein factors and producing different types of short interfering RNAs (siRNAs). One is specifically triggered by high-copy transgenes, and the other by feeding cells with double-stranded RNA (dsRNA)-producing bacteria. In this study, we designed a forward genetic screen for mutants deficient in dsRNA-induced silencing, and a powerful method to identify the relevant mutations by whole-genome sequencing. We present a set of 47 mutant alleles for five genes, revealing two previously unknown RNAi factors: a novel Paramecium-specific protein (Pds1) and a Cid1-like nucleotidyl transferase. Analyses of allelic diversity distinguish non-essential and essential genes and suggest that the screen is saturated for non-essential, single-copy genes. We show that non-essential genes are specifically involved in dsRNA-induced RNAi while essential ones are also involved in transgene-induced RNAi. One of the latter, the RNA-dependent RNA polymerase RDR2, is further shown to be required for all known types of siRNAs, as well as for sexual reproduction. These results open the way for the dissection of the genetic complexity, interconnection, mechanisms and natural functions of RNAi pathways in P. tetraurelia.

  7. Spiruline, a virtuous algae

    OpenAIRE

    Various, Authors

    2015-01-01

    A short video about a local development practice focusing on the production and commercialization of spiruline, an algae used as an nutritional integrator. The practice was one of six prize winners resulting from a national competition for innovative practices of local development, launched by the Senegalese Ministry of local governance, development and territorial planning, with funding from the Italian Cooperation and technical support from the KIP International School.

  8. Imaging of Ca2+ transients induced in Paramecium cells by a polyamine secretagogue.

    Science.gov (United States)

    Klauke, N; Plattner, H

    1997-04-01

    In Paramecium tetraurelia cells analysis of transient changes in Ca2+ concentration, [Ca2+]i, during aminoethyldextran (AED) stimulated synchronous ( or =20 seconds. Because of cell dislocation during vigorous trichocyst exocytosis, 7S cells could be reasonably analysed only by CLSM after Fluo-3 injection. In 7S cells cortical [Ca2+]i transients are strictly parallelled by trichocyst exocytosis, i.e. in the subsecond time range and precisely at the site of AED application. Injection of Ca2+ is a much less efficient trigger for exocytosis. Ca2+-buffer injections suggest a requirement of [Ca2+]i >1 to 10 microM for exocytosis to occur in response to AED. In conclusion, our data indicate: (i) correlation of cortical [Ca2+]i transients with exocytosis, as well as (ii) occurrence of a similar signal transduction mechanism in mutant cells where target structures may be defective or absent.

  9. Attempts to retreat from a dead-ended long capillary by backward swimming in Paramecium.

    Science.gov (United States)

    Kunita, Itsuki; Kuroda, Shigeru; Ohki, Kaito; Nakagaki, Toshiyuki

    2014-01-01

    We have observed how the ciliate Paramecium attempts to retreat from the dead-end of a long capillary that is too narrow for turning. After many trial-and-error episodes of short-term backward swimming (SBS), which is the conventional avoidance behavior exhibited in free swimming when an obstacle is faced, long-term backward swimming (LBS) that lasted five to ten times longer was developed. LBS may have a beneficial effect for complete withdrawal from the capillary space, although in our experiment it was impossible for the organism to do so due to the capillary length. In order to identify a physically possible mechanism for LBS, we propose model equations for the membrane potential of Hodgkin-Huxley type, which describe the control of ciliary movement. The physiological implications and physical mechanism of the development of LBS are discussed.

  10. Attempts to retreat from a dead-ended long capillary by backward swimming in Paramecium

    Directory of Open Access Journals (Sweden)

    Itsuki eKunita

    2014-06-01

    Full Text Available We have observed how the ciliate Paramecium attempts to retreat from the dead-end of a long capillary that is too narrow for turning. After many trial-and-error episodes of short-term backward swimming (SBS, which is the conventional avoidance behavior exhibited in free swimming when an obstacle is faced, long-term backward swimming (LBS that lasted five to ten times longer was developed. LBS may have a beneficial effect for complete withdrawal from the capillary space, although in our experiment it was impossible for the organism to do so due to the capillary length. In order to identify a physically possible mechanism for LBS, we propose model equations for the membrane potential of Hodgkin-Huxley type, which describe the control of ciliary movement. The physiological implications and physical mechanism of the development of LBS are discussed.

  11. A comparative hybridization analysis of yeast DNA with Paramecium parafusin- and different phosphoglucomutase-specific probes.

    Science.gov (United States)

    Wyroba, E; Satir, B H

    2000-01-01

    Molecular probes designed for the parafusin (PFUS), the Paramecium exocytic-sensitive phosphoglycoprotein, gave distinct hybridization patterns in Saccharomyces cerevisiae genomic DNA when compared with different phosphoglucomutase specific probes. These include two probes identical to segments of yeast phosphoglucomutase (PGM) genes 1 and 2. Neither of the PGM probes revealed the 7.4 and 5.9 kb fragments in Bgl II-cut yeast DNA digest detected with the 1.6 kb cloned PFUS cDNA and oligonucleotide constructed to the PFUS region (insertion 3--I-3) not found in other species. PCR amplification with PFUS-specific primers generated yeast DNA-species of the predicted molecular size which hybridized to the I-3 probe. A search of the yeast genome database produced an unassigned nucleotide sequence that showed 55% identity to parafusin gene and 37% identity to PGM2 (the major isoform of yeast phosphoglucomutase) within the amplified region.

  12. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, L.M.; Forney, J.D.

    1984-08-01

    A screening procedure was devised for the isolation of X-ray-induced mutations affecting the expression of the A immobilization antigen (i-antigen) in Paramecium tetraurelia. Two of the mutations isolated by this procedure proved to be in modifier genes. The two genes are unlinked to each other and unlinked to the structural A i-antigen gene. These are the first modifier genes identified in a Paramecium sp. that affect surface antigen expression. Another mutation was found to be a deletion of sequences just downstream from the A i-antigen gene. In cells carrying this mutation, the A i-antigen gene lies in close proximity to the end of a macronuclear chromosome. The expression of the A i-antigen is not affected in these cells, demonstrating that downstream sequences are not important for the regulation and expression of the A i-antigen gene. A stable cell line was also recovered which shows non-Mendelian inheritance of a macronuclear deletion of the A i-antigen gene. This mutant does not contain the gene in its macronucleus, but contains a complete copy of the gene in its micronucleus. In the cytoplasm of wild-type animals, the micronuclear gene is included in the developing macronucleus; in the cytoplasm of the mutant, the incorporation of the A i-antigen gene into the macronucleus is inhibited. This is the first evidence that a mechanism is available in ciliates to control the expression of a gene by regulating its incorporation into developing macronuclei.

  13. Miocene Coralline algae

    Energy Technology Data Exchange (ETDEWEB)

    Bosence, D.W.J.

    1988-01-01

    The coralline algae (Order Corallinales) were sedimentologically and ecologically important during the Miocene, a period when they were particularly abundant. The many poorly described and illustrated species and the lack of quantitative data in coralline thalli make specific determinations particularly difficult, but some species are well known and widespread in the Tethyan area. The sedimentologic importance of the Miocene coralline algae is reflected in the abundance of in-situ coralline buildups, rhodoliths, and coralline debris facies at Malta and Spain; similar sequences are known throughout the Tethyan Miocene. In-situ buildups vary from leafy crustose biostromes to walled reefs with dense coralline crusts and branches. Growth forms are apparently related to hydraulic energy. Rhodoliths vary from leafy, crustose, and open-branched forms in muddy sediments to dense, crustose, and radial-branching forms in coarse grainstones. Rhodolith form and internal structure correlate closely with hydraulic energy. Coralline genera are conservative and, as such, are useful in paleoenvironmental analysis. Of particular interest are the restricted depth ranges of recent coralline genera. More research is needed on the sedimentology, paleoecology, and systematics of the Cenozoic corallines, as they have particular value in paleoenvironmental analysis.

  14. Novel Insights into the Development and Function of Cilia Using the Advantages of the Paramecium Cell and Its Many Cilia

    Directory of Open Access Journals (Sweden)

    Junji Yano

    2015-07-01

    Full Text Available Paramecium species, especially P. tetraurelia and caudatum, are model organisms for modern research into the form and function of cilia. In this review, we focus on the ciliary ion channels and other transmembrane proteins that control the beat frequency and wave form of the cilium by controlling the signaling within the cilium. We put these discussions in the context of the advantages that Paramecium brings to the understanding of ciliary motility: mutants for genetic dissections of swimming behavior, electrophysiology, structural analysis, abundant cilia for biochemistry and modern proteomics, genomics and molecular biology. We review the connection between behavior and physiology, which allows the cells to broadcast the function of their ciliary channels in real time. We build a case for the important insights and advantages that this model organism continues to bring to the study of cilia.

  15. Differences in infectivity between endosymbiotic Chlorella variabilis cultivated outside host Paramecium bursaria for 50 years and those immediately isolated from host cells after one year of reendosymbiosis

    Directory of Open Access Journals (Sweden)

    Y. Kodama

    2016-01-01

    Full Text Available Chlorella variabilis strain NC64A is an intracellular photobiont of the ciliate Paramecium bursaria. NC64A was isolated from P. bursaria nearly 50 years ago and was thereafter cultivated outside the host. This study was undertaken to detect changes in its infectivity to P. bursaria and its auxotrophy for growth outside the host induced during long-term cultivation. NC64A can grow in Modified Bold's Basal Medium but not in C medium, whereas another symbiotic Chlorella variabilis strain, 1N, that was recently isolated from the host grew in C medium but not in Modified Bold's Basal Medium. With regards infectivity, NC64A in the logarithmic phase of growth showed low infectivity to alga-removed P. bursaria cells, whereas those in the early stationary phase showed high infectivity of about 30%. Those in the decay phase of growth showed no infectivity. Results show that NC64A has infectivity, but the infection rate depends on their culture age in the growth curve. Furthermore, NC64A that had been re-infected to P. bursaria for more than one year and isolated from the host showed a nearly 100% infection rate, which indicates that NC64A can recover its infectivity by re-infection to P. bursaria.

  16. Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation. [Paramecium tetraurelia; Synechococcus lividus

    Energy Technology Data Exchange (ETDEWEB)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

    1987-05-01

    Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y.

  17. Cross-study analysis of genomic data defines the ciliate multigenic epiplasmin family: strategies for functional analysis in Paramecium tetraurelia

    Directory of Open Access Journals (Sweden)

    Ravet Viviane

    2009-06-01

    Full Text Available Abstract Background The sub-membranous skeleton of the ciliate Paramecium, the epiplasm, is composed of hundreds of epiplasmic scales centered on basal bodies, and presents a complex set of proteins, epiplasmins, which belong to a multigenic family. The repeated duplications observed in the P. tetraurelia genome present an interesting model of the organization and evolution of a multigenic family within a single cell. Results To study this multigenic family, we used phylogenetic, structural, and analytical transcriptional approaches. The phylogenetic method defines 5 groups of epiplasmins in the multigenic family. A refined analysis by Hydrophobic Cluster Analysis (HCA identifies structural characteristics of 51 epiplasmins, defining five separate groups, and three classes. Depending on the sequential arrangement of their structural domains, the epiplasmins are defined as symmetric, asymmetric or atypical. The EST data aid in this classification, in the identification of putative regulating sequences such as TATA or CAAT boxes. When specific RNAi experiments were conducted using sequences from either symmetric or asymmetric classes, phenotypes were drastic. Local effects show either disrupted or ill-shaped epiplasmic scales. In either case, this results in aborted cell division. Using structural features, we show that 4 epiplasmins are also present in another ciliate, Tetrahymena thermophila. Their affiliation with the distinctive structural groups of Paramecium epiplasmins demonstrates an interspecific multigenic family. Conclusion The epiplasmin multigenic family illustrates the history of genomic duplication in Paramecium. This study provides a framework which can guide functional analysis of epiplasmins, the major components of the membrane skeleton in ciliates. We show that this set of proteins handles an important developmental information in Paramecium since maintenance of epiplasm organization is crucial for cell morphogenesis.

  18. Differential distribution of calcium stores in paramecium cells. Occurrence of a subplasmalemmal store with a calsequestrin-like protein.

    Science.gov (United States)

    Plattner, H; Habermann, A; Kissmehl, R; Klauke, N; Majoul, I; Söling, H D

    1997-04-01

    We have analyzed in Paramecium cells the occurrence and intracellular distribution of the high capacity/low affinity calcium-binding proteins, calsequestrin (CS) and calreticulin (CR) using antibodies against CS from rat skeletal muscle and against CR from rat liver, respectively. As revealed by Western blots, a CS-like protein isolated by affinity chromatography from Paramecium cells comigrated with CS isolated from rat skeletal muscle. The immunoreactivity of this 53 kDa protein band was blocked when the antibodies had been preadsorbed with purified rat CS. A band of identical molecular size was shown to bind 45Ca in overlays. By immunofluorescence and immunogold labeling this CS-like protein was localized selectively to the extended subplasmalemmal calcium stores, the "alveolar sacs", which cover almost the entire cell surface. Concomitantly the 53 kDa 45Ca-binding band became increasingly intense in overlays as we increasingly enriched alveolar sacs. Antibodies against rat CR react with a 61 kDa band but do not cross-react with CS-like protein in Paramecium. These antibodies selectively stained intracellular reticular structures, identified bona fide as endoplasmic reticulum.

  19. The membrane skeleton in Paramecium: Molecular characterization of a novel epiplasmin family and preliminary GFP expression results.

    Science.gov (United States)

    Pomel, Sébastien; Diogon, Marie; Bouchard, Philippe; Pradel, Lydie; Ravet, Viviane; Coffe, Gérard; Viguès, Bernard

    2006-02-01

    Previous attempts to identify the membrane skeleton of Paramecium cells have revealed a protein pattern that is both complex and specific. The most prominent structural elements, epiplasmic scales, are centered around ciliary units and are closely apposed to the cytoplasmic side of the inner alveolar membrane. We sought to characterize epiplasmic scale proteins (epiplasmins) at the molecular level. PCR approaches enabled the cloning and sequencing of two closely related genes by amplifications of sequences from a macronuclear genomic library. Using these two genes (EPI-1 and EPI-2), we have contributed to the annotation of the Paramecium tetraurelia macronuclear genome and identified 39 additional (paralogous) sequences. Two orthologous sequences were found in the Tetrahymena thermophila genome. Structural analysis of the 43 sequences indicates that the hallmark of this new multigenic family is a 79 aa domain flanked by two Q-, P- and V-rich stretches of sequence that are much more variable in amino-acid composition. Such features clearly distinguish members of the multigenic family from epiplasmic proteins previously sequenced in other ciliates. The expression of Green Fluorescent Protein (GFP)-tagged epiplasmin showed significant labeling of epiplasmic scales as well as oral structures. We expect that the GFP construct described herein will prove to be a useful tool for comparative subcellular localization of different putative epiplasmins in Paramecium.

  20. Transposon Invasion of the Paramecium Germline Genome Countered by a Domesticated PiggyBac Transposase and the NHEJ Pathway

    Directory of Open Access Journals (Sweden)

    Emeline Dubois

    2012-01-01

    Full Text Available Sequences related to transposons constitute a large fraction of extant genomes, but insertions within coding sequences have generally not been tolerated during evolution. Thanks to their unique nuclear dimorphism and to their original mechanism of programmed DNA elimination from their somatic nucleus (macronucleus, ciliates are emerging model organisms for the study of the impact of transposable elements on genomes. The germline genome of the ciliate Paramecium, located in its micronucleus, contains thousands of short intervening sequences, the IESs, which interrupt 47% of genes. Recent data provided support to the hypothesis that an evolutionary link exists between Paramecium IESs and Tc1/mariner transposons. During development of the macronucleus, IESs are excised precisely thanks to the coordinated action of PiggyMac, a domesticated piggyBac transposase, and of the NHEJ double-strand break repair pathway. A PiggyMac homolog is also required for developmentally programmed DNA elimination in another ciliate, Tetrahymena. Here, we present an overview of the life cycle of these unicellular eukaryotes and of the developmentally programmed genome rearrangements that take place at each sexual cycle. We discuss how ancient domestication of a piggyBac transposase might have allowed Tc1/mariner elements to spread throughout the germline genome of Paramecium, without strong counterselection against insertion within genes.

  1. Dynamin-association with agonist-mediated sequestration of beta-adrenergic receptor in single-cell eukaryote Paramecium.

    Science.gov (United States)

    Wiejak, Jolanta; Surmacz, Liliana; Wyroba, Elzbieta

    2004-04-01

    Evidence that dynamin is associated with the sequestration of the Paramecium beta(2)-adrenergic receptor (betaAR) immunoanalogue is presented. We previously reported a dramatic change in the distribution of betaAR analogue in the subcellular fractions upon isoproterenol treatment: it is redistributed from the membraneous to the cytosolic fraction, as revealed by quantitative image analysis of western blots. Here we confirm and extend this observation by laser scanning confocal and immunogold electron microscopy. In the presence of isoproterenol (10 micro mol l(-1)) betaAR translocated from the cell surface into dynamin-positive vesicles in the cytoplasmic compartment, as observed by dual fluorochrome immunolabeling in a series of the confocal optical sections. Colocalization of betaAR and dynamin in the tiny endocytic vesicles was detected by further electron microscopic studies. Generally receptor sequestration follows its desensitization, which is initiated by receptor phosphorylation by G-protein-coupled receptor kinase. We cloned and sequenced the gene fragment of 407 nucleotides homologous to the beta-adrenergic receptor kinase (betaARK): its deduced amino acid sequence shows 51.6% homology in 126 amino acids that overlap with the human betaARK2 (GRK3), and may participate in Paramecium betaAR desensitization. These results suggest that the molecular machinery for the desensitization/sequestration of the receptor immunorelated to vertebrate betaAR exists in unicellular PARAMECIUM:

  2. Gulf ring algae

    Science.gov (United States)

    Although they rank among the tiniest of the microspcopic phytoplankton, coccolithophore algae aid oceanographers studying the Gulf Stream rings and the ring boundaries. The algal group could help to identify more precisely the boundary of the warm rings of water that spin off from the Gulf Stream and become independent pools of warm water in the colder waters along the northeastern U.S. coast.Coccolithophore populations in the Gulf Stream rings intrigue oceanographers for two reasons: The phytoplankton are subjected to an environment that changes every few days, and population explosions within one coccolithophore species seem to be associated with changes in the characteristics of ocean water, said Pat Blackwelder, an associate professor at the Nova Oceanographic Center in Dania, Fla. She is one of many studying the physics, chemistry, and biology of warm core rings. A special oceanography session on these rings was held at the recent AGU Fall Meeting/ASLO Winter Meeting.

  3. Transgenic algae engineered for higher performance

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, Pat J; Anderson, Penelope S; Knight, Thomas J

    2014-10-21

    The present disclosure relates to transgenic algae having increased growth characteristics, and methods of increasing growth characteristics of algae. In particular, the disclosure relates to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and to transgenic algae comprising a glutamine phenylpyruvate transaminase transgene and a glutamine synthetase.

  4. Paramecium BBS genes are key to presence of channels in Cilia

    Directory of Open Access Journals (Sweden)

    Valentine Megan

    2012-09-01

    Full Text Available Abstract Background Changes in genes coding for ciliary proteins contribute to complex human syndromes called ciliopathies, such as Bardet-Biedl Syndrome (BBS. We used the model organism Paramecium to focus on ciliary ion channels that affect the beat form and sensory function of motile cilia and evaluate the effects of perturbing BBS proteins on these channels. Methods We used immunoprecipitations and mass spectrometry to explore whether Paramecium proteins interact as in mammalian cells. We used RNA interference (RNAi and swimming behavior assays to examine the effects of BBS depletion on ciliary ion channels that control ciliary beating. Combining RNA interference and epitope tagging, we examined the effects of BBS depletion of BBS 7, 8 and 9 on the location of three channels and a chemoreceptor in cilia. Results We found 10 orthologs of 8 BBS genes in P. tetraurelia. BBS1, 2, 4, 5, 7, 8 and 9 co-immunoprecipitate. While RNAi reduction of BBS 7 and 9 gene products caused loss and shortening of cilia, RNAi for all BBS genes except BBS2 affected patterns of ciliary motility that are governed by ciliary ion channels. Swimming behavior assays pointed to loss of ciliary K+ channel function. Combining RNAi and epitope tagged ciliary proteins we demonstrated that a calcium activated K+ channel was no longer located in the cilia upon depletion of BBS 7, 8 or 9, consistent with the cells’ swimming behavior. The TRPP channel PKD2 was also lost from the cilia. In contrast, the ciliary voltage gated calcium channel was unaffected by BBS depletion, consistent with behavioral assays. The ciliary location of a chemoreceptor for folate was similarly unperturbed by the depletion of BBS 7, 8 or 9. Conclusions The co-immunoprecipitation of BBS 1,2,4,5,7,8, and 9 suggests a complex of BBS proteins. RNAi for BBS 7, 8 or 9 gene products causes the selective loss of K+ and PKD2 channels from the cilia while the critical voltage gated calcium channel and a

  5. Electrophoretic karyotype polymorphism of sibling species of the Paramecium aurelia complex.

    Science.gov (United States)

    Nekrasova, Irina V; Przyboś, Ewa; Rautian, Maria S; Potekhin, Alexey A

    2010-01-01

    Variability of karyotypes is one of the main mechanisms of speciation in organisms. Electrophoretic karyotypes of the macronucleus (MAC) obtained by pulsed-field gel electrophoresis were compared for 86 strains of all 15 sibling species of the Paramecium aurelia complex in order to determine if karyotype differences corresponded to biological species boundaries. Because the electrophoretic karyotype of the MAC reflects indirectly the frequency and distribution of fragmentation sites in the micronuclear (MIC) chromosomes, any change in MAC electrophoretic karyotype may be a marker of certain chromosomal mutations in the MIC. Thirteen main variants of electrophoretic MAC karyotypes were observed in this species complex. Ten of them appeared to correspond to biological species, while the three other variants characterized several species each. Intraspecific polymorphism was observed for several species: in some cases a certain variant of MAC karyotype was specific for all strains from the same part of the world. Distribution of the MAC karyotype variants along molecular phylogenetic trees of the P. aurelia complex shows that isolation of each species or group of species of this complex was accompanied by divergence in the molecular organization of the genome.

  6. Photoreactivation in Paramecium tetraurelia under conditions of various degrees of ozone layer depletion.

    Science.gov (United States)

    Takahashi, Akihisa; Kumatani, Toshihiro; Usui, Saori; Tsujimura, Ryoko; Seki, Takaharu; Morimoto, Kouichi; Ohnishi, Takeo

    2005-01-01

    Photoreactivation (PR) is an efficient survival mechanism that helps protect cells against the harmful effects of solar-ultraviolet (UV) radiation. The PR mechanism involves photolyase, just one enzyme, and can repair DNA damage, such as cyclobutane-pyrimidine dimers (CPD) induced by near-UV/blue light, a component of sunlight. Although the balance of near-UV/blue light and far-UV light reaching the Earth's surface could be altered by the atmospheric ozone layer's depletion, experiments simulating this environmental change and its possible effects on life have not yet been performed. To quantify the strength of UVB in sunlight reaching the Earth's surface, we measured the number of CPD generated in plasmid DNA after UVB irradiation or exposure to sunlight. To simulate the increase of solar-UV radiation resulting from the ozone layer depletion, Paramecium tetraurelia was exposed to UVB and/or sunlight in clear summer weather. PR recovery after exposure to sunlight was complete at a low dose rate of 0.2 J/m2 x s, but was less efficient when the dose rate was increased by a factor of 2.5 to 0.5 J/m2 x s. It is suggested that solar-UV radiation would not influence the cell growth of P. tetraurelia for the reason of high PR activity even when the ozone concentration was decreased 30% from the present levels.

  7. Epiplasmins and epiplasm in paramecium: the building of a submembraneous cytoskeleton.

    Science.gov (United States)

    Aubusson-Fleury, Anne; Bricheux, Geneviève; Damaj, Raghida; Lemullois, Michel; Coffe, Gérard; Donnadieu, Florence; Koll, France; Viguès, Bernard; Bouchard, Philippe

    2013-07-01

    In ciliates, basal bodies and associated appendages are bound to a submembrane cytoskeleton. In Paramecium, this cytoskeleton takes the form of a thin dense layer, the epiplasm, segmented into regular territories, the units where basal bodies are inserted. Epiplasmins, the main component of the epiplasm, constitute a large family of 51 proteins distributed in 5 phylogenetic groups, each characterized by a specific molecular design. By GFP-tagging, we analyzed their differential localisation and role in epiplasm building and demonstrated that: 1) The epiplasmins display a low turnover, in agreement with the maintenance of an epiplasm layer throughout the cell cycle; 2) Regionalisation of proteins from different groups allows us to define rim, core, ring and basal body epiplasmins in the interphase cell; 3) Their dynamics allows definition of early and late epiplasmins, detected early versus late in the duplication process of the units. Epiplasmins from each group exhibit a specific combination of properties. Core and rim epiplasmins are required to build a unit; ring and basal body epiplasmins seem more dispensable, suggesting that they are not required for basal body docking. We propose a model of epiplasm unit assembly highlighting its implication in structural heredity in agreement with the evolutionary history of epiplasmins.

  8. Silencing-associated and meiosis-specific small RNA pathways in Paramecium tetraurelia

    Science.gov (United States)

    Lepère, Gersende; Nowacki, Mariusz; Serrano, Vincent; Gout, Jean-François; Guglielmi, Gérard; Duharcourt, Sandra; Meyer, Eric

    2009-01-01

    Distinct small RNA pathways are involved in the two types of homology-dependent effects described in Paramecium tetraurelia, as shown by a functional analysis of Dicer and Dicer-like genes and by the sequencing of small RNAs. The siRNAs that mediate post-transcriptional gene silencing when cells are fed with double-stranded RNA (dsRNA) were found to comprise two subclasses. DCR1-dependent cleavage of the inducing dsRNA generates ∼23-nt primary siRNAs from both strands, while a different subclass of ∼24-nt RNAs, characterized by a short untemplated poly-A tail, is strictly antisense to the targeted mRNA, suggestive of secondary siRNAs that depend on an RNA-dependent RNA polymerase. An entirely distinct pathway is responsible for homology-dependent regulation of developmental genome rearrangements after sexual reproduction. During early meiosis, the DCL2 and DCL3 genes are required for the production of a highly complex population of ∼25-nt scnRNAs from all types of germline sequences, including both strands of exons, introns, intergenic regions, transposons and Internal Eliminated Sequences. A prominent 5′-UNG signature, and a minor fraction showing the complementary signature at positions 21–23, indicate that scnRNAs are cleaved from dsRNA precursors as duplexes with 2-nt 3′ overhangs at both ends, followed by preferential stabilization of the 5′-UNG strand. PMID:19103667

  9. A Ca sup 2+ influx associated with exocytosis is specifically abolished in a Paramecium exocytotic mutant

    Energy Technology Data Exchange (ETDEWEB)

    Kerboeuf, D.; Cohen, J. (Centre National de la Recherche Scientifique, Gif-sur-Yvette (France))

    1990-12-01

    A Paramecium possesses secretory organelles called trichocysts which are docked beneath the plasma membrane awaiting an external stimulus that triggers their exocytosis. Membrane fusion is the sole event provoked by the stimulation and can therefore be studied per se. Using 3 microM aminoethyl dextran as a vital secretagogue, we analyzed the movements of calcium (Ca{sup 2+}) during the discharge of trichocysts. We showed that (a) external Ca{sup 2+}, at least at 3 X 10(-7) M, is necessary for AED to induce exocytosis; (b) a dramatic and transient influx of Ca{sup 2+} as measured from {sup 45}Ca uptake is induced by AED; (c) this influx is independent of the well-characterized voltage-operated Ca{sup 2+} channels of the ciliary membranes since it persists in a mutant devoid of these channels; and (d) this influx is specifically abolished in one of the mutants unable to undergo exocytosis, nd12. We propose that the Ca{sup 2+} influx induced by AED reflects an increase in membrane permeability through the opening of novel Ca{sup 2+} channel or the activation of other Ca{sup 2+} transport mechanism in the plasma membrane. The resulting rise in cytosolic Ca{sup 2+} concentration would in turn induce membrane fusion. The mutation nd12 would affect a gene product involved in the control of plasma membrane permeability to Ca{sup 2+}, specifically related to membrane fusion.

  10. Putative DNA-dependent RNA polymerase in Mitochondrial Plasmid of Paramecium caudatum Stock GT704

    Directory of Open Access Journals (Sweden)

    Trina Ekawati Tallei

    2015-10-01

    Full Text Available Mitochondria of Paramecium caudatum stock GT704 has a set of four kinds of linear plasmids with sizes of 8.2, 4.1, 2.8 and 1.4 kb. The plasmids of 8.2 and 2.8 kb exist as dimers consisting of 4.1- and 1.4-kb monomers, respectively. The plasmid 2.8 kb, designated as pGT704-2.8, contains an open reading frame encodes for putative DNA-dependent RNA polymerase (RNAP. This study reveals that this RNAP belongs to superfamily of DNA/RNA polymerase and family of T7/T3 single chain RNA polymerase and those of mitochondrial plasmid of fungi belonging to Basidiomycota and Ascomycota. It is suggested that RNAP of pGT704-2.8 can perform transcription without transcription factor as promoter recognition. Given that only two motifs were found, it could not be ascertained whether this RNAP has a full function independently or integrated with mtDNA in carrying out its function.

  11. Growth retardation of Paramecium and mouse cells by shielding them from background radiation.

    Science.gov (United States)

    Kawanishi, Masanobu; Okuyama, Katsuyuki; Shiraishi, Kazunori; Matsuda, Yatsuka; Taniguchi, Ryoichi; Shiomi, Nobuyuki; Yonezawa, Morio; Yagi, Takashi

    2012-01-01

    In the 1970s and 1980s, Planel et al. reported that the growth of paramecia was decreased by shielding them from background radiation. In the 1990s, Takizawa et al. found that mouse cells displayed a decreased growth rate under shielded conditions. The purpose of the present study was to confirm that growth is impaired in organisms that have been shielded from background radiation. Radioprotection was produced with a shielding chamber surrounded by a 15 cm thick iron wall and a 10 cm thick paraffin wall that reduced the γ ray and neutron levels in the chamber to 2% and 25% of the background levels, respectively. Although the growth of Paramecium tetraurelia was not impaired by short-term radioprotection (around 10 days), which disagreed with the findings of Planel et al., decreased growth was observed after long-term (40-50 days) radiation shielding. When mouse lymphoma L5178Y cells were incubated inside or outside of the shielding chamber for 7 days, the number of cells present on the 6th and 7th days under the shielding conditions was significantly lower than that present under the non-shielding conditions. These inhibitory effects on cell growth were abrogated by the addition of a ¹³⁷Cs γ-ray source disk to the chamber. Furthermore, no growth retardation was observed in XRCC4-deficient mouse M10 cells, which display impaired DNA double strand break repair.

  12. Anomalies of autogamy in Paramecium tetraurelia temperature sensitive mutant induced by heat treatment.

    Science.gov (United States)

    Prajer, M; Iftode, F

    2001-01-01

    The run of autogamy in temperature sensitive mutant ts401, carrying also the mutation of trichocysts nd3a, at permissive (26 degrees C) and non-permissive temperature (35 degrees C) was studied and compared with this process in wild d4-2 stock of Paramecium tetraurelia. The effect of heat treatment on programmed nuclear and cortical events was investigated using cytological silver impregnation Fernandez-Galiano method and immunofluorescence technique with the application of two anti-alpha-tubulin antibodies. The appearance of cells with some large macronuclear fragments and an excess number of micronuclei suggests that nuclear differentiation is inhibited at restrictive temperature and that macronuclear regeneration takes place in this thermosensitive mutant. In such cells impaired oral reorganization was observed. After slight refeeding at the late autogamy, cells stopped at first postautogamous division were induced by heat treatment. The most striking feature of these abnormal divisions was the lack of a basal body duplication wave, which suggests that production of gamma-tubulin, structural protein being the essential component of the microtubule organizing centres, is disturbed at high temperature.

  13. The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

    Directory of Open Access Journals (Sweden)

    Olivier Arnaiz

    Full Text Available Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a

  14. The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

    Science.gov (United States)

    Arnaiz, Olivier; Mathy, Nathalie; Baudry, Céline; Malinsky, Sophie; Aury, Jean-Marc; Denby Wilkes, Cyril; Garnier, Olivier; Labadie, Karine; Lauderdale, Benjamin E; Le Mouël, Anne; Marmignon, Antoine; Nowacki, Mariusz; Poulain, Julie; Prajer, Malgorzata; Wincker, Patrick; Meyer, Eric; Duharcourt, Sandra; Duret, Laurent; Bétermier, Mireille; Sperling, Linda

    2012-01-01

    Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES) from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a fraction of the

  15. Internalization of cycloheptaamylose-dansyl chloride complex during labelling of surface membrane in living Paramecium aurelia cells.

    Science.gov (United States)

    Giordano, P A; Wyroba, E; Bottiroli, G

    1985-01-01

    Internalization of cycloheptaamylose-dansyl chloride complex during surface labelling of living long-term starved Paramecium aurelia cells has been observed. This process may be inhibited by pretreatment of the ciliates with dichloroisoproterenol. Uptake of cycloheptaamylose-dansyl chloride may be visualized only after UV preirradiation: the appearance of orange-fluorescing vacuoles of diameter 2.3-4.5 micron may then be observed. Microspectrographic analysis performed on the cells and dansyl derivatives indicates that this fluorescence is produced by a photochemical reaction of dansyl chloride - released from CDC complex inside the digestive vacuoles-under the influence of UV irradiation.

  16. Algae Bloom in a Lake

    Directory of Open Access Journals (Sweden)

    David Sanabria

    2008-01-01

    Full Text Available The objective of this paper is to determine the likelihood of an algae bloom in a particular lake located in upstate New York. The growth of algae in this lake is caused by a high concentration of phosphorous that diffuses to the surface of the lake. Our calculations, based on Fick's Law, are used to create a mathematical model of the driving force of diffusion for phosphorous. Empirical observations are also used to predict whether the concentration of phosphorous will diffuse to the surface of this lake within a specified time and under specified conditions.

  17. Cyanobacteria: algas productoras de toxinas

    OpenAIRE

    Echenique, Ricardo Omar; Giannuzzi, Leda; Andrinolo, Darío

    2007-01-01

    El de las Cyanobacteria es un grupo de algas con características particulares. Por su coloración, dada por los pigmentos que posee, comúnmente se las conoce como algas verde-azules. Según registros fósiles, son los primeros organismos fotosintéticos aparecidos en nuestro planeta (3000-3500 millones de años), por esto se los consideran los responsables de originar la atmósfera inicial que posibilitó la evolución del resto de los seres vivos habitantes de la Tierra. Estos organismos, desde micr...

  18. Formation of algae growth constitutive relations for improved algae modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Gharagozloo, Patricia E.; Drewry, Jessica Louise.

    2013-01-01

    This SAND report summarizes research conducted as a part of a two year Laboratory Directed Research and Development (LDRD) project to improve our abilities to model algal cultivation. Algae-based biofuels have generated much excitement due to their potentially large oil yield from relatively small land use and without interfering with the food or water supply. Algae mitigate atmospheric CO2 through metabolism. Efficient production of algal biofuels could reduce dependence on foreign oil by providing a domestic renewable energy source. Important factors controlling algal productivity include temperature, nutrient concentrations, salinity, pH, and the light-to-biomass conversion rate. Computational models allow for inexpensive predictions of algae growth kinetics in these non-ideal conditions for various bioreactor sizes and geometries without the need for multiple expensive measurement setups. However, these models need to be calibrated for each algal strain. In this work, we conduct a parametric study of key marine algae strains and apply the findings to a computational model.

  19. The Paramecium aurelia species complex, frequency and co-occurrence across Europe.

    Science.gov (United States)

    Przyboś, Ewa; Barth, Dana; Berendonk, Thomas U

    2008-01-01

    In Europe, 10 among the 15 known species of the Paramecium aurelia complex have been recorded including P. primaurelia, P. biaurelia, P. triaurelia, P. tetraurelia, P. pentaurelia, P. sexaurelia, P. septaurelia, P. novaurelia, P. dodecaurelia, and P. tredecaurelia. The occurrence of species of this complex in Europe has been estimated on the basis of the number of habitats and the ratio value (r.v.), i.e. the number of habitats for a defined species to the total number of habitats with species of the P. aurelia complex. The r.v. presents the relative frequency of the particular species to others of the complex. In total, 483 habitats were considered. The dominant species is P. novaurelia (r.v. 0.38, found in 186 habitats), followed by P. biaurelia (r.v. 0.26 in 125 habitats) and P. primaurelia (0.23 in 113 habitats). Other species are less frequent, such as P. tetraurelia (r.v. 0.06 found in 29 habitats), P. triaurelia (r.v. 0.04 in 22 habitats), or rare such as P. septaurelia (r.v. 0.025 found in 12 habitats), as well as P. pentaurelia and P. sexaurelia (r.v. 0.02 for both, found in 11 and 10 habitats, respectively). P. dodecaurelia was found in three localities in Europe (r.v. 0.006) and P. tredecaurelia is known from a single habitat (r.v. 0.002). This paper presents new populations, found at present, of species of the P. aurelia complex in Europe (Germany, Italy, Spain, Iceland, Poland, Great Britain) and one new from the USA.

  20. Highly precise and developmentally programmed genome assembly in Paramecium requires ligase IV-dependent end joining.

    Directory of Open Access Journals (Sweden)

    Aurélie Kapusta

    2011-04-01

    Full Text Available During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs, each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs, which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5' overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ, are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi-mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5'-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3' ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a "cut-and-close" mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new

  1. Role of delta-tubulin and the C-tubule in assembly of Paramecium basal bodies

    Directory of Open Access Journals (Sweden)

    Beisson Janine

    2001-03-01

    Full Text Available Abstract Background A breakthrough in the understanding of centriole assembly was provided by the characterization of the UNI3 gene in Chlamydomonas. Deletion of this gene, found to encode a novel member of the tubulin superfamily, delta-tubulin, results in the loss of the C-tubule, in the nine microtubule triplets which are the hallmark of centrioles and basal bodies. Delta-tubulin homologs have been identified in the genomes of mammals and protozoa, but their phylogenetic relationships are unclear and their function is not yet known. Results Using the method of gene-specific silencing, we have inactivated the Paramecium delta-tubulin gene, which was recently identified. This inactivation leads to loss of the C-tubule in all basal bodies, without any effect on ciliogenesis. This deficiency does not directly affect basal body duplication, but perturbs the cortical cytoskeleton, progressively leading to mislocalization and loss of basal bodies and to altered cell size and shape. Furthermore, additional loss of B- and even A-tubules at one or more triplet sites are observed: around these incomplete cylinders, the remaining doublets are nevertheless positioned according to the native ninefold symmetry. Conclusions The fact that in two distinct phyla, delta-tubulin plays a similar role provides a new basis for interpreting phylogenetic relationships among delta-tubulins. The role of delta-tubulin in C-tubule assembly reveals that tubulins contribute subtle specificities at microtubule nucleation sites. Our observations also demonstrate the existence of a prepattern for the ninefold symmetry of the organelle which is maintained even if less than 9 triplets develop.

  2. A calcium-dependent potassium current is increased by a single-gene mutation in Paramecium.

    Science.gov (United States)

    Hennessey, T M; Kung, C

    1987-01-01

    The membrane currents of wild type Paramecium tetraurelia and the behavioral mutant teaA were analyzed under voltage clamp. The teaA mutant was shown to have a greatly increased outward current which was blocked completely by the combined use of internally delivered Cs+ and external TEA+. This, along with previous work (Satow, Y., Kung, C., 1976, J. Exp. Biol. 65:51-63) identified this as a K+ current. It was further found to be a calcium-activated K+ current since this increased outward K+ current cannot be elicited when the internal calcium is buffered with injected EGTA. The mutation pwB, which blocks the inward calcium current, also blocks this increased outward K+ current in teaA. This shows that this mutant current is activated by calcium through the normal depolarization-sensitive calcium channel. While tail current decay kinetic analysis showed that the apparent inactivation rates for this calcium-dependent K+ current are the same for mutant and wild type, the teaA current activates extremely rapidly. It is fully activated within 2 msec. This early activation of such a large outward current causes a characteristic reduction in the amplitude of the action potential of the teaA mutant. The teaA mutation had no effect on any of the other electrophysiological parameters examined. The phenotype of the teaA mutant is therefore a general decrease in responsiveness to depolarizing stimuli because of a rapidly activating calcium-dependent K+ current which prematurely repolarizes the action potential.

  3. 21 CFR 184.1120 - Brown algae.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Brown algae. 184.1120 Section 184.1120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1120 Brown algae. (a) Brown algae are seaweeds of the species...

  4. Ultrastructural changes of the UV-irradiated micronucleus in vegetative cells of Paramecium bursaria and its functional importance

    Energy Technology Data Exchange (ETDEWEB)

    Borkhsenius, O.N.; Fokin, S.I. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

    1982-01-01

    Ultrastructural micronucleus (MI) changes of vegetative cells in Paramecium bursaria in 0.5-7 h after MI ultraviolet irradiation and cell posterity with irradiated MI after different periods (2.6 and 30 days, three years) after ultraviolet irradiation have been studied. It is established that MI irradiation at a dose of 306J/m/sup 2/ doesn't result in its loss in postradiation generations however in posterity MI considerable ultrastructural changes occur. In two days after operation the shell of descendant MI of irradiated Paramecium bursaria forms multiple blades; small chromatin blocks considerably increase in sizes and, as a rule, occupy the central position in a nucleus. During later periods after irradiation (6 days) density of chromatin elements in MI begins to change. By the 30th day in MI fine-fibrillar karyoplasm detected are only not numerous chromatin structures scattered in disorder. The results obtained point to the existence of the ''cryptic'' type MIs are not revealed at the light-optical level but preserved in a series of postradiation generations. The presence of such MIs in viable cultures of P. bursaria confirms indirectly MI significance in vegetatic life of P. bursaria.

  5. RT-PCR and Northern blot analysis in search for a putative Paramecium beta-adrenergic receptor.

    Science.gov (United States)

    Płatek, A; Wiejak, J; Wyroba, E

    1999-01-01

    RT-PCR and Northern blot analysis were performed in order to search for a putative beta-adrenergic receptor (beta-AR) in Paramecium using several beta2-adrenergic-specific molecular probes. Under strictly defined RT-PCR conditions DNA species of expected molecular size about 360 bp were generated with the primers corresponding to the universal mammalian beta2-AR sequence tagged sites (located within the 4th and the 6th transmembrane regions of the receptor). This RT-PCR product hybridized in Southern blot analysis with the oligonucleotide probe designed to the highly conservative beta2-AR region involved in G-proteins interaction and located within the amplified region. Northern hybridization was performed on Paramecium total RNA and mRNA with human beta2-AR cDNA and two oligonucleotide probes: the first included Phe 290 involved in agonist binding (Strader et al., 1995) and the second was the backward RT-PCR primer. All these probes revealed the presence of about 2 kb mRNA which is consistent with the size of beta2-AR transcripts found in higher eukaryotes.

  6. Primary and secondary siRNA synthesis triggered by RNAs from food bacteria in the ciliate Paramecium tetraurelia.

    Science.gov (United States)

    Carradec, Quentin; Götz, Ulrike; Arnaiz, Olivier; Pouch, Juliette; Simon, Martin; Meyer, Eric; Marker, Simone

    2015-02-18

    In various organisms, an efficient RNAi response can be triggered by feeding cells with bacteria producing double-stranded RNA (dsRNA) against an endogenous gene. However, the detailed mechanisms and natural functions of this pathway are not well understood in most cases. Here, we studied siRNA biogenesis from exogenous RNA and its genetic overlap with endogenous RNAi in the ciliate Paramecium tetraurelia by high-throughput sequencing. Using wild-type and mutant strains deficient for dsRNA feeding we found that high levels of primary siRNAs of both strands are processed from the ingested dsRNA trigger by the Dicer Dcr1, the RNA-dependent RNA polymerases Rdr1 and Rdr2 and other factors. We further show that this induces the synthesis of secondary siRNAs spreading along the entire endogenous mRNA, demonstrating the occurrence of both 3'-to-5' and 5'-to-3' transitivity for the first time in the SAR clade of eukaryotes (Stramenopiles, Alveolates, Rhizaria). Secondary siRNAs depend on Rdr2 and show a strong antisense bias; they are produced at much lower levels than primary siRNAs and hardly contribute to RNAi efficiency. We further provide evidence that the Paramecium RNAi machinery also processes single-stranded RNAs from its bacterial food, broadening the possible natural functions of exogenously induced RNAi in this organism.

  7. Algae -- a poor man's HAART?

    Science.gov (United States)

    Teas, Jane; Hebert, James R; Fitton, J Helen; Zimba, Paul V

    2004-01-01

    Drawing inferences from epidemiologic studies of HIV/AIDS and in vivo and in vitro HIV inhibition by algae, we propose algal consumption as one unifying characteristic of countries with anomalously low rates. HIV/AIDS incidence and prevalence in Eastern Asia ( approximately 1/10000 adults in Japan and Korea), compared to Africa ( approximately 1/10 adults), strongly suggest that differences in IV drug use and sexual behavior are insufficient to explain the 1000-fold variation. Even in Africa, AIDS/HIV rates vary. Chad has consistently reported low rates of HIV/AIDS (2-4/100). Possibly not coincidentally, most people in Japan and Korea eat seaweed daily and the Kanemba, one of the major tribal groups in Chad, eat a blue green alga (Spirulina) daily. Average daily algae consumption in Asia and Africa ranges between 1 and 2 tablespoons (3-13 g). Regular consumption of dietary algae might help prevent HIV infection and suppress viral load among those infected.

  8. Scenario studies for algae production

    NARCIS (Netherlands)

    Slegers, P.M.

    2014-01-01

    Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass producti

  9. Macro algae as substrate for biogas production

    DEFF Research Database (Denmark)

    Møller, Henrik; Sarker, Shiplu; Gautam, Dhan Prasad

    Algae as a substrate for biogas is superior to other crops since it has a much higher yield of biomass per unit area and since algae grows in the seawater there will be no competition with food production on agricultural lands. So far, the progress in treating different groups of algae as a source...... of energy is promising. In this study 5 different algae types were tested for biogas potential and two algae were subsequent used for co-digestion with manure. Green seaweed, Ulva lactuca and brown seaweed Laminaria digitata was co-digested with cattle manure at mesophilic and thermophilic condition...

  10. Allelopatrhic effect of Acorus tatarinowii upon algae

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Besides competing with algae for light and mineralnutrients (i.e. N, P, etc.), the root system of Acorus tatarinowii excretes some chemical substances, which injure and eliminate alga cells, to inhibit the growth of the algae. When the algae cells were treated in "A. tatarinowii water", some of the chlorophyll a were destroyed and the photosynthetic rate of algae decreased markedly and the ability of alga cells to deoxidize triphenyltetrazolium chloride (TTC) reduced greatly. Then alga cells turned from bright red to bluish green under fluorescence microscope. These showed that the allelopathic effects of A.tatarinowii on algae were obvious and planting A. tatarinowii can control some green algae. The experiment on the extractions of the secretions of the root system showed that the inhibitory effect had a concentration effect. If the concentration of the root secretion was below 30 /disc, the inhibitory rate was negative; if it was over 45 /disc, the inhibitory rate was positive. This proved that the influence of the root secretion on the same acceptor was a kind of concentration effect. When the concentration of the root secretion was low, it promoted the growth of algae; when the concentration reached a definite threshold value, it restrained the growth of algae. In present case, the threshold value was between 30 /disc and 45 u?disc.

  11. Complete sequence of the mitochondrial genome of Tetrahymena pyriformis and comparison with Paramecium aurelia mitochondrial DNA.

    Science.gov (United States)

    Burger, G; Zhu, Y; Littlejohn, T G; Greenwood, S J; Schnare, M N; Lang, B F; Gray, M W

    2000-03-24

    We report the complete nucleotide sequence of the Tetrahymena pyriformis mitochondrial genome and a comparison of its gene content and organization with that of Paramecium aurelia mtDNA. T. pyriformis mtDNA is a linear molecule of 47,172 bp (78.7 % A+T) excluding telomeric sequences (identical tandem repeats of 31 bp at each end of the genome). In addition to genes encoding the previously described bipartite small and large subunit rRNAs, the T. pyriformis mitochondrial genome contains 21 protein-coding genes that are clearly homologous to genes of defined function in other mtDNAs, including one (yejR) that specifies a component of a cytochrome c biogenesis pathway. As well, T. pyriformis mtDNA contains 22 open reading frames of unknown function larger than 60 codons, potentially specifying proteins ranging in size from 74 to 1386 amino acid residues. A total of 13 of these open reading frames ("ciliate-specific") are found in P. aurelia mtDNA, whereas the remaining nine appear to be unique to T. pyriformis; however, of the latter, five are positionally equivalent and of similar size in the two ciliate mitochondrial genomes, suggesting they may also be homologous, even though this is not evident from sequence comparisons. Only eight tRNA genes encoding seven distinct tRNAs are found in T. pyriformis mtDNA, formally confirming a long-standing proposal that most T. pyriformis mitochondrial tRNAs are nucleus-encoded species imported from the cytosol. Atypical features of mitochondrial gene organization and expression in T. pyriformis mtDNA include split and rearranged large subunit rRNA genes, as well as a split nad1 gene (encoding subunit 1 of NADH dehydrogenase of respiratory complex I) whose two segments are located on and transcribed from opposite strands, as is also the case in P. aurelia. Gene content and arrangement are very similar in T. pyriformis and P. aurelia mtDNAs, the two differing by a limited number of duplication, inversion and rearrangement events

  12. Tolerance of ciliated protozoan Paramecium bursaria (Protozoa,Ciliophora) to ammonia and nitrites

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The tolerance to ammonia and nitrites in freshwater ciliate Paramecium bursaria was measured in a conventional open system. The ciliate was exposed to different concentrations of ammonia and nitrites for 2h and 12h in order to determine the lethal concentrations. Linear regression analysis revealed that the 2h-LC50 value for ammonia was 95.94 mg/L and for nitrite 27.35 mg/L using probit scale method (with 95% confidence intervals). There was a linear correlation between the mortality probit scale and logarithmic concentration of ammonia which fit by a regression equation y=7.32x-9.51 (R2=0.98; y, mortality probit scale; x, logarithmic concentration of ammonia), by which 2 h-LC50 value for ammonia was fotnd to be 95.50 mg/L. A linear correlation between mortality probit scales and logarithmic concentration of nitrite is also followed the regression equation y=2.86x+0.89 (R2=0.95; y, mortality probit scale; x, logarithmic concentration of nitrite). The regression analysis of toxicity curves showed that the linear correlation between exposed time of ammonia-N LC50 value and ammonia-N LC50 value followed the regression equation y=2862.85e-0.0ax (R2=0.95; y, duration of exposure to LC50 value; x, LC50 value), and that between exposed time of nitrite-N LC50 value and nitrite-N LC50 value followed the regression equation y = 127.15e-0.13x (R2=0.91; y, exposed time of LC50 value; x, LC50 value). The results demonstrate that the tolerance to ammonia in P. bursaria is considerably higher than that of the larvae or juveniles of some metozoa, e.g. cultured prawns and oysters. In addition, ciliates, as bacterial predators, are likely to play a positive role in maintaining and improving water quality in aquatic environments with high-level ammonium, such as sewage treatment systems.

  13. Synthetic polyester from algae oil.

    Science.gov (United States)

    Roesle, Philipp; Stempfle, Florian; Hess, Sandra K; Zimmerer, Julia; Río Bártulos, Carolina; Lepetit, Bernard; Eckert, Angelika; Kroth, Peter G; Mecking, Stefan

    2014-06-23

    Current efforts to technically use microalgae focus on the generation of fuels with a molecular structure identical to crude oil based products. Here we suggest a different approach for the utilization of algae by translating the unique molecular structures of algae oil fatty acids into higher value chemical intermediates and materials. A crude extract from a microalga, the diatom Phaeodactylum tricornutum, was obtained as a multicomponent mixture containing amongst others unsaturated fatty acid (16:1, 18:1, and 20:5) phosphocholine triglycerides. Exposure of this crude algae oil to CO and methanol with the known catalyst precursor [{1,2-(tBu2 PCH2)2C6H4}Pd(OTf)](OTf) resulted in isomerization/methoxycarbonylation of the unsaturated fatty acids into a mixture of linear 1,17- and 1,19-diesters in high purity (>99 %). Polycondensation with a mixture of the corresponding diols yielded a novel mixed polyester-17/19.17/19 with an advantageously high melting and crystallization temperature.

  14. Parasites in algae mass culture

    Directory of Open Access Journals (Sweden)

    Todd William Lane

    2014-06-01

    Full Text Available Parasites are now known to be ubiquitous across biological systems and can play an important role in modulating algal populations. However, there is a lack of extensive information on their role in artificial ecosystems such as algal production ponds and photobioreactors. Parasites have been implicated in the demise of algal blooms. Because individual mass culture systems often tend to be unialgal and a select few algal species are in wide scale application, there is an increased potential for parasites to have a devastating effect on commercial scale monoculture. As commercial algal production continues to expand with a widening variety of applications, including biofuel, food and pharmaceuticals, the parasites associated with algae will become of greater interest and potential economic impact. A number of important algal parasites have been identified in algal mass culture systems in the last few years and this number is sure to grow as the number of commercial algae ventures increases. Here, we review the research that has identified and characterized parasites infecting mass cultivated algae, the techniques being proposed and or developed to control them, and the potential impact of parasites on the future of the algal biomass industry.

  15. Molecular analysis (RAPD-PCR) of inter-strain hybrids of the Paramecium aurelia species complex (Ciliophora, Protozoa).

    Science.gov (United States)

    Przyboś, Ewa; Prajer, Małgorzata; Greczek-Stachura, Magdalena

    2005-01-01

    RAPD-PCR analysis showed that species of the Paramecium aurelia complex possessed characteristic band patterns and that the majority were also polymorphic intra-specifically. A comparison of band patterns was performed for some inter-strain hybrids within P. primaurelia, P. tetraurelia, P. pentaurelia, P. septaurelia, P. octaurelia, P. decaurelia, P. dodecaurelia, P. tredecaurelia, and P. quadecaurelia to band patterns characteristic for the parental strains. The investigations, however, did not reveal a close correlation between the degree of inbreeding characteristic for the species and similarity of genotypes. A low similarity of hybrid and parental band patterns was observed in P. octaurelia, P. dodecaurelia, P. quadecaurelia and also P. primaurelia. A high similarity of band patterns of hybrid and parental strains was found in P. tetraurelia, P. septaurelia, P. decaurelia, and P. tredecaurelia.

  16. New stands of species of the Paramecium aurelia complex (Ciliophora, Protozoa) in Europe and South America (Ecuador).

    Science.gov (United States)

    Przybós, Ewa; Rautian, Maria; Surmacz, Marta

    2014-01-01

    The occurrence of species of the P. aurelia complex has been studied at a large scale in Europe and the majority of known species of the complex have been found there. However, a different number of habitats were studied in particular zones of Europe, the greatest number in the central zone. Herein new stands of several species of the Paramecium aurelia complex are presented from Europe including P. primaurelia, P. biaurelia, P. triaurelia, P. octaurelia, P. novaurelia, and P. dodecaurelia. In South America, studies concerning the distribution of the P. aurelia species complex were carried out only occasionally and the presence of some cosmopolitan species of the complex has been recorded, i.e. P. primaurelia, P. biaurelia, and P. tetraurelia. Recently, new stands of P. primaurelia and P. septaurelia were found in Ecuador. Ciliate biogeography and distribution is also discussed.

  17. X-ray microanalysis in cryosections of natively frozen Paramecium caudatum with regard to ion distribution in ciliates

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, M.; Meyer, R.; Zierold, K.

    1985-01-01

    Cells of Paramecium caudatum were shock-frozen without pretreatment for cryoultramicrotomy and freeze-dried for subsequent X-ray microanalysis. Na, Mg, P, S, Cl, K, and Ca were detected in different amounts in several subcellular compartments. In particular, calcium was localized below the cell surface (pellicle). Trichocysts were found to contain significant amounts of Na in their base but not in the tip. Na, Mg, P, S, Cl, K, Ca were found in electron dense deposits within the lumen of the contractile vacuole. A small K concentration was found in the cytoplasm and in the mitochondria. X-ray microanalysis of the element distribution in different subcellular compartments provides information for the understanding of cellular functions such as exocytosis, locomotion, and ion regulation.

  18. Effect of wortmannin and phorbol ester on Paramecium fluid-phase uptake in the presence of transferrin

    Directory of Open Access Journals (Sweden)

    J Wiejak

    2009-12-01

    Full Text Available The kinetics of the uptake of the fluid phase marker Lucifer Yellow (LY, and its alteration by wortmannin, an inhibitor of phosphatidylinositol-3 kinase (PI-3K, and the PKC modulators: GF 109203 X, an inhibitor, and phorbol ester, an activator was studied in eukaryotic model Paramecium aurelia. Spectrophotometric quantification of LY accumulation was performed in the presence or absence of transferrin, a marker of receptor-mediated endocytosis. Internalization of LY showed a curvilinear kinetics: the high initial rate of LYuptake (575 ng LY/ mg protein /hr decreased almost 5-fold within 15 min, reaching plateau at 126 ng/ mg protein /hr. Transferrin induced a small increase (7.5% in the fluid phase uptake rate (after 5 min followed by a small decrease at longer incubation times. Lucifer Yellow and transferrin (visualized by streptavidin– FITC were localized in Paramecium by 3-D reconstruction by confocal microscopy. LY showed a scattered, diffuse fluorescence typical of fluid phase uptake whereas transferrin accumulated in membrane-surrounded endosomes. Wortmannin did not affect LY accumulation but decreased it when transferrin was present in the incubation medium. This suggests an effect on the transferrin uptake pathway, presumably on the stage of internalization in “mixing” endosomes to which transferrin and LY were targeted. Phorbol ester diminished LY accumulation by 22% and this effect persisted up to 25 min of incubation. PKC inhibitor did not affect LY uptake. However, in the presence of transferrin, the LY uptake increased within the first 15 minutes followed by a rapid 20% decrease in comparison to the control. Such an effect of PKC modulators suggests that PMA action on fluid phase uptake is not directly mediated by PKC.

  19. Effect of wortmannin and phorbol ester on Paramecium fluid-phase uptake in the presence of transferrin.

    Science.gov (United States)

    Wiejak, J; Surmacz, L; Wyroba, E

    2001-01-01

    The kinetics of the uptake of the fluid phase marker Lucifer Yellow (LY), and its alteration by wortmannin, an inhibitor of phosphatidylinositol-3 kinase (PI-3K), and the PKC modulators: GF 109203 X, an inhibitor, and phorbol ester, an activator was studied in eukaryotic model Paramecium aurelia. Spectrophotometric quantification of LY accumulation was performed in the presence or absence of transferrin, a marker of receptor-mediated endocytosis. Internalization of LY showed a curvilinear kinetics: the high initial rate of LY uptake (575 ng LY/mg protein/hr) decreased almost 5-fold within 15 min, reaching plateau at 126 ng/mg protein/hr. Transferrin induced a small increase (7.5%) in the fluid phase uptake rate (after 5 min) followed by a small decrease at longer incubation times. Lucifer Yellow and transferrin (visualized by streptavidin-FITC) were localized in Paramecium by 3-D reconstruction by confocal microscopy. LY showed a scattered, diffuse fluorescence typical of fluid phase uptake whereas transferrin accumulated in membrane-surrounded endosomes. Wortmannin did not affect LY accumulation but decreased it when transferrin was present in the incubation medium. This suggests an effect on the transferrin uptake pathway, presumably on the stage of internalization in "mixing" endosomes to which transferrin and LY were targeted. Phorbol ester diminished LY accumulation by 22% and this effect persisted up to 25 min of incubation. PKC inhibitor did not affect LY uptake. However, in the presence of transferrin, the LY uptake increased within the first 15 minutes followed by a rapid 20% decrease in comparison to the control. Such an effect of PKC modulators suggests that PMA action on fluid phase uptake is not directly mediated by PKC.

  20. Toxic Effects of Phthalates on Ocean Algae

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This article discusses the interaction of phthalates and ocean algae based on the standard appraisal method of chemical medicine for algae toxicity. Through the experiments on the toxic effects of dimethyl (o-) phthalate (DMP), diethyl (o-) phthalate (DEP), dibutyl (o-)phthalate (DBP) on ocean algae, the 50 % lethal concentration of the three substances in 48 h and 96 h for plaeodectylum tricornutum, platymonas sp, isochrysis galbana, and skeletonema costatum is obtained. Tolerance limits of the above ocean algae of DMP, DEP, and DBP are discussed.

  1. Photobioreactors for mass cultivation of algae.

    Science.gov (United States)

    Ugwu, C U; Aoyagi, H; Uchiyama, H

    2008-07-01

    Algae have attracted much interest for production of foods, bioactive compounds and also for their usefulness in cleaning the environment. In order to grow and tap the potentials of algae, efficient photobioreactors are required. Although a good number of photobioreactors have been proposed, only a few of them can be practically used for mass production of algae. One of the major factors that limits their practical application in algal mass cultures is mass transfer. Thus, a thorough understanding of mass transfer rates in photobioreactors is necessary for efficient operation of mass algal cultures. In this review article, various photobioreactors that are very promising for mass production of algae are discussed.

  2. 草履虫对四尾栅藻的生长抑制性研究%Degradation of Growing Scenedesmus quadricauda by Paramecium

    Institute of Scientific and Technical Information of China (English)

    张琨; 王图锦; 吴睿若; 陈珊; 吉芳英

    2011-01-01

    为探究原生生物在治理富营养化水体水华方面的潜在作用,使用一种原生生物一草履虫与生长期和成熟期四尾栅藻混合培养,研究草履虫的吞噬性对栅藻的生长抑制作用.结果表明,在繁殖旺盛、生长活跃的时期,草履虫通过其在捕食过程中的吞噬作用,能够对栅藻产生吞噬.在栅藻生长稳定期,草履虫对栅藻具有一定的吞噬效率,最大吞噬效率达到8.93%.在栅藻繁殖较为迅速的对数生长期,草履虫对其具有明显抑制效果,显著延迟栅藻的生长.%To explore the potential function of the protozoa in preventing algal blooms, the experiment of degradation of growing Scenedesmus quadricauda by Paramecium was done. Results indicated that Paramecium has the ability of degrading Scenedesmus quadricauda in predation process. When cells entered the stable stage, part of Scenedesmus quadricauda could be degraded by Paramecium, with the maximum degradation rate up to 8.93%. In logarithmic stage, Paramecium significantly inhibited the growth of Scenedesmus quadricauda, and prolonged the logarithmic stage.

  3. Community feature of planktonic algae in artificial beach lake, Dishui Lake%人工滩涂湖泊滴水湖浮游藻类群落特征

    Institute of Scientific and Technical Information of China (English)

    陈立婧; 景钰湘; 吴艳芳; 李娟英; 陈冲; 张饮江

    2012-01-01

    于2009年3月-2010年2月逐月对中国最大人工滩涂湖泊——滴水湖的浮游藻类群落特征进行研究.利用CANOCO 4.5软件对浮游藻类数据和环境因子数据进行典范对应分析(CCA),以揭示浮游藻类对生态环境的响应.结果表明:全年共检测到浮游藻类186种及变种,隶属于8门92属,其中绿藻门种类最多,其次是蓝藻门和硅藻门;主要优势种为小席藻、微小平裂藻、银灰平裂藻、不定微囊藻、弱细颤藻、啮蚀隐藻、四尾栅藻、扁圆卵形藻;藻类的年均丰度和年均生物量分别为(4552.29±4591.33) ×104 cells·L-1和8.15±6.63 mg·L-1,藻类现存量各月份间差异极显著(P<0.01),但站点间差异不显著;多样性分析显示,藻类物种多样性较好;典范对应分析表明,水温、总氮等是影响滴水湖藻类群落结构的主要因素.%Dishui Lake is the largest artificial beach lake in China. From March 2009 to February 2010, a monthly investigation was conducted on the community feature of planktonic algae in the Lake. Canonical correspondence analysis (CCA) was applied to study the correlations between the algae species diversity and environmental factors by using software CANOCO 4. 5, aimed to reveal the responses of the algae community to the ecological environment of the Lake. A total of 186 species and varieties of planktonic algae were detected, belonging to 92 genera of 8 phyla. Chlorophyta had the most species, followed by Cyanophyta and Bacillariophyta. Phorimid-ium tenus, Merismopedia tenuissima, M. glauca, Microcystis incerta, Oscillatoria tenuis, Crypto-monas erosa, Scenedesmus quadricauda, and Cocconeis placentula were the dominant species. The mean annual abundance and biomass of the planktonic algae were (4552. 29±4591.33) × 104 cells · L-1 and 8. 15±6. 63 mg · L-1, respectively. There was a significant difference (P<0.01) in the standing crop of the algae between months, but no remarkable difference was

  4. Cultivation of macroscopic marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Ryther, J.H.

    1982-11-01

    The red alga Gracilaria tikvahiae may be grown outdoors year-round in central Florida with yields averaging 35.5 g dry wt/m/sup 2/.day, greater than the most productive terrestrial plants. This occurs only when the plants are in a suspended culture, with vigorous aeration and an exchange of 25 or more culture volumes of enriched seawater per day, which is not cost-effective. A culture system was designed in which Gracilaria, stocked at a density of 2 kg wet wt/m/sup 2/, grows to double its biomass in one to two weeks; it is then harvested to its starting density, and anaerobically digested to methane. The biomass is soaked for 6 hours in the digester residue, storing enough nutrients for two weeks' growth in unenriched seawater. The methane is combusted for energy and the waste gas is fed to the culture to provide mixing and CO/sub 2/, eliminating the need for aeration and seawater exchange. The green alga Ulva lactuca, unlike Gracilaria, uses bicarbonate as a photosynthesis carbon source, and can grow at high pH, with little or no free CO/sub 2/. It can therefore produce higher yields than Gracilaria in low water exchange conditions. It is also more efficiently converted to methane than is Gracilaria, but cannot tolerate Florida's summer temperatures so cannot be grown year-round. Attempts are being made to locate or produce a high-temperature tolerant strain.

  5. Modeling and optimization of algae growth

    NARCIS (Netherlands)

    Thornton, Anthony; Weinhart, Thomas; Bokhove, Onno; Zhang, Bowen; Sar, van der Dick M.; Kumar, Kundan; Pisarenco, Maxim; Rudnaya, Maria; Savceno, Valeriu; Rademacher, Jens; Zijlstra, Julia; Szabelska, Alicja; Zyprych, Joanna; Schans, van der Martin; Timperio, Vincent; Veerman, Frits; Frank, J.; van der Mei, R.; den Boer, A.; Bosman, J.; Bouman, N.; van Dam, S.; Verhoef, C.

    2010-01-01

    The wastewater from greenhouses has a high amount of mineral contamination and an environmentally-friendly method of removal is to use algae to clean this runo water. The algae consume the minerals as part of their growth process. In addition to cleaning the water, the created algal bio-mass has a v

  6. Vanadium in marine mussels and algae

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, K.R.; Bahr, B. [Alfred-Wegener-Institut fuer Polar- und Meeresforschung, Bremerhaven (Germany); Ott, J. [Fachhochschule Hamburg (Germany). Fachbereich Naturwissenschaftliche Technik, Studiengang Biotechnologie

    2000-01-01

    A method is presented which is sensitive enough for the determination of vanadium (V) in marine organisms such as mussels and algae. It was sufficiently checked by a reference material and it was applied to V determination in blue mussels and brown algae from the German Bight. (orig.)

  7. Take a Dip! Culturing Algae Is Easy.

    Science.gov (United States)

    James, Daniel E.

    1983-01-01

    Describes laboratory activities using algae as the organisms of choice. These include examination of typical algal cells, demonstration of alternation of generations, sexual reproduction in Oedogonium, demonstration of phototaxis, effect of nitrate concentration on Ankistrodesmus, and study of competition between two algae in the same environment.…

  8. Composting of waste algae: a review.

    Science.gov (United States)

    Han, Wei; Clarke, William; Pratt, Steven

    2014-07-01

    Although composting has been successfully used at pilot scale to manage waste algae removed from eutrophied water environments and the compost product applied as a fertiliser, clear guidelines are not available for full scale algae composting. The review reports on the application of composting to stabilize waste algae, which to date has mainly been macro-algae, and identifies the peculiarities of algae as a composting feedstock, these being: relatively low carbon to nitrogen (C/N) ratio, which can result in nitrogen loss as NH3 and even N2O; high moisture content and low porosity, which together make aeration challenging; potentially high salinity, which can have adverse consequence for composting; and potentially have high metals and toxin content, which can affect application of the product as a fertiliser. To overcome the challenges that these peculiarities impose co-compost materials can be employed.

  9. Algae inhibition experiment and load characteristics of the algae solution

    Science.gov (United States)

    Xiong, L.; Gao, J. X.; Zhang, Y. X.; Yang, Z. K.; Zhang, D. Q.; He, W.

    2016-08-01

    It is necessary to inhibit microbial growth in an industrial cooling water system. This paper has developed a Monopolar/Bipolar polarity high voltage pulser with load adaptability for an algal experimental study. The load characteristics of the Chlorella pyrenoidosa solution were examined, and it was found that the solution load is resistive. The resistance is related to the plate area, concentration, and temperature of the solution. Furthermore, the pulser's treatment actually inhibits the algae cell growth. This article also explores the influence of various parameters of electric pulses on the algal effect. After the experiment, the optimum pulse parameters were determined to be an electric field intensity of 750 V/cm, a pulse width per second of 120μs, and monopolar polarity.

  10. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia.

    Directory of Open Access Journals (Sweden)

    Antoine Marmignon

    2014-08-01

    Full Text Available During somatic differentiation, physiological DNA double-strand breaks (DSB can drive programmed genome rearrangements (PGR, during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES. IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium

  11. Ku-mediated coupling of DNA cleavage and repair during programmed genome rearrangements in the ciliate Paramecium tetraurelia.

    Science.gov (United States)

    Marmignon, Antoine; Bischerour, Julien; Silve, Aude; Fojcik, Clémentine; Dubois, Emeline; Arnaiz, Olivier; Kapusta, Aurélie; Malinsky, Sophie; Bétermier, Mireille

    2014-08-01

    During somatic differentiation, physiological DNA double-strand breaks (DSB) can drive programmed genome rearrangements (PGR), during which DSB repair pathways are mobilized to safeguard genome integrity. Because of their unique nuclear dimorphism, ciliates are powerful unicellular eukaryotic models to study the mechanisms involved in PGR. At each sexual cycle, the germline nucleus is transmitted to the progeny, but the somatic nucleus, essential for gene expression, is destroyed and a new somatic nucleus differentiates from a copy of the germline nucleus. In Paramecium tetraurelia, the development of the somatic nucleus involves massive PGR, including the precise elimination of at least 45,000 germline sequences (Internal Eliminated Sequences, IES). IES excision proceeds through a cut-and-close mechanism: a domesticated transposase, PiggyMac, is essential for DNA cleavage, and DSB repair at excision sites involves the Ligase IV, a specific component of the non-homologous end-joining (NHEJ) pathway. At the genome-wide level, a huge number of programmed DSBs must be repaired during this process to allow the assembly of functional somatic chromosomes. To understand how DNA cleavage and DSB repair are coordinated during PGR, we have focused on Ku, the earliest actor of NHEJ-mediated repair. Two Ku70 and three Ku80 paralogs are encoded in the genome of P. tetraurelia: Ku70a and Ku80c are produced during sexual processes and localize specifically in the developing new somatic nucleus. Using RNA interference, we show that the development-specific Ku70/Ku80c heterodimer is essential for the recovery of a functional somatic nucleus. Strikingly, at the molecular level, PiggyMac-dependent DNA cleavage is abolished at IES boundaries in cells depleted for Ku80c, resulting in IES retention in the somatic genome. PiggyMac and Ku70a/Ku80c co-purify as a complex when overproduced in a heterologous system. We conclude that Ku has been integrated in the Paramecium DNA cleavage

  12. Algae Biofuel in the Nigerian Energy Context

    Science.gov (United States)

    Elegbede, Isa; Guerrero, Cinthya

    2016-05-01

    The issue of energy consumption is one of the issues that have significantly become recognized as an important topic of global discourse. Fossil fuels production reportedly experiencing a gradual depletion in the oil-producing nations of the world. Most studies have relatively focused on biofuel development and adoption, however, the awareness of a prospect in the commercial cultivation of algae having potential to create economic boost in Nigeria, inspired this research. This study aims at exploring the potential of the commercialization of a different but commonly found organism, algae, in Nigeria. Here, parameters such as; water quality, light, carbon, average temperature required for the growth of algae, and additional beneficial nutrients found in algae were analysed. A comparative cum qualitative review of analysis was used as the study made use of empirical findings on the work as well as the author's deductions. The research explored the cultivation of algae with the two major seasonal differences (i.e. rainy and dry) in Nigeria as a backdrop. The results indicated that there was no significant difference in the contribution of algae and other sources of biofuels as a necessity for bioenergy in Nigeria. However, for an effective sustainability of this prospect, adequate measures need to be put in place in form of funding, provision of an economically-enabling environment for the cultivation process as well as proper healthcare service in the face of possible health hazard from technological processes. Further studies can seek to expand on the potential of cultivating algae in the Harmattan season.

  13. DGDG and Glycolipids in Plants and Algae.

    Science.gov (United States)

    Kalisch, Barbara; Dörmann, Peter; Hölzl, Georg

    2016-01-01

    Photosynthetic organelles in plants and algae are characterized by the high abundance of glycolipids, including the galactolipids mono- and digalactosyldiacylglycerol (MGDG, DGDG) and the sulfolipid sulfoquinovosyldiacylglycerol (SQDG). Glycolipids are crucial to maintain an optimal efficiency of photosynthesis. During phosphate limitation, the amounts of DGDG and SQDG increase in the plastids of plants, and DGDG is exported to extraplastidial membranes to replace phospholipids. Algae often use betaine lipids as surrogate for phospholipids. Glucuronosyldiacylglycerol (GlcADG) is a further glycolipid that accumulates under phosphate deprived conditions. In contrast to plants, a number of eukaryotic algae contain very long chain polyunsaturated fatty acids of 20 or more carbon atoms in their glycolipids. The pathways and genes for galactolipid and sulfolipid synthesis are largely conserved between plants, Chlorophyta, Rhodophyta and algae with complex plastids derived from secondary or tertiary endosymbiosis. However, the relative contribution of the endoplasmic reticulum- and plastid-derived lipid pathways for glycolipid synthesis varies between plants and algae. The genes for glycolipid synthesis encode precursor proteins imported into the photosynthetic organelles. While most eukaryotic algae contain the plant-like galactolipid (MGD1, DGD1) and sulfolipid (SQD1, SQD2) synthases, the red alga Cyanidioschyzon harbors a cyanobacterium-type DGDG synthase (DgdA), and the amoeba Paulinella, derived from a more recent endosymbiosis event, contains cyanobacterium-type enzymes for MGDG and DGDG synthesis (MgdA, MgdE, DgdA).

  14. 21 CFR 73.275 - Dried algae meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Dried algae meal. 73.275 Section 73.275 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.275 Dried algae meal. (a) Identity. The color additive dried algae meal is a dried mixture of algae cells (genus Spongiococcum, separated from its culture...

  15. New Stands of Species of the Paramecium aurelia Complex; is the Occurrence of Particular Species Limited by Temperature Barriers?

    Science.gov (United States)

    Przyboś, Ewa; Prajer, Małgorzata

    2015-01-01

    The occurrence of ciliates, especially the Paramecium aurelia complex, has not yet been studied in many parts of the world, or sampling was done only occasionally. Generally, the southern hemisphere still awaits investigation. In North America only the USA was studied in greater detail; the majority of species of the complex were there recorded. In Asia, more frequent sampling was performed only in Japan and Asiatic Russia. Europe was studied more carefully, however, a different number of habitats was studied in particular zones of Europe, the least in the southern zone. New stands of P. tetraurelia , P. sexaurelia, P. octaurelia, and P. novaurelia were revealed as a result of the present investigations carried out in Africa (Mozambique--P. tetraurelia, P. sexaurelia), Asia (Indonesia--P. sexaurelia), borderland of Asia and Europe (Georgia--P. octaurelia), and Europe (Macedonia--P. tetraurelia and Romania--P. novaurelia). Are climatic zones the main factor limiting the occurrence of species of the P. aurelia complex? Analysis of data on the distribution of the P. aurelia species complex in warm "tropical" zones on different continents may suggest such preferences for some species, including P. sexaurelia, P. octaurelia, P. tredecaurelia, P. quadecaurelia. The first two of these species were recorded herein in warm or "tropical" zone.

  16. The first European stand of Paramecium sonneborni (P. aurelia complex), a species known only from North America (Texas, USA).

    Science.gov (United States)

    Przyboś, Ewa; Tarcz, Sebastian; Rautian, Maria; Lebedeva, Natalia

    2014-06-01

    P. aurelia is currently defined as a complex of 15 sibling species including 14 species designated by Sonneborn (1975) and one, P. sonneborni, by Aufderheide et al. (1983). The latter was known from only one stand (Texas, USA). The main reason for the present study was a new stand of Paramecium in Cyprus, with strains recognized as P. sonneborni based on the results of strain crosses, cytological slides, and molecular analyses of three loci (ITS1-5.8S-ITS2-5'LSU rDNA, COI, CytB). The new stand of P. sonneborni in Europe shows that the species, previously considered endemic, may have a wider range. This demonstrates the impact of under-sampling on the knowledge of the biogeography of microbial eukaryotes. Phylogenetic trees based on all the studied fragments revealed that P. sonneborni forms a separate cluster that is closer to P. jenningsi and P. schewiakoffi than to the other members of the P. aurelia complex.

  17. New Paramecium quadecaurelia strains (P. aurelia spp. complex, Ciliophora) identified by molecular markers (rDNA and mtDNA).

    Science.gov (United States)

    Przyboś, Ewa; Tarcz, Sebastian; Dusi, Eike

    2013-08-01

    Paramecium quadecaurelia is a rare species (previously known only from two locations) belonging to the P. aurelia species complex. In the present paper, fragments of an rDNA gene (ITS1-5.8S-ITS2-5' rDNA) and mtDNA genes (cytochrome oxidase subunit I and cytochrome b regions) were employed to assist in the identification and characterization of three new strains collected from Ecuador and Thailand. Molecular data were confirmed by mating reactions. In rDNA and mtDNA trees constructed for species of the P. aurelia complex, all P. quadecaurelia strains, including the three new strains discussed in this study and two known previously from Australia and Africa, form a monophyletic but differentiated clade. The present study shows that genetic differentiation among the strains of P. quadecaurelia is equal to or even greater than the distances between some other P. aurelia species, e.g., P. primaurelia and P. pentaurelia. Such great intra-specific differentiation may indicate a future splitting of the P. quadecaurelia species into reproductively isolated lines.

  18. Purification, in vitro reassembly, and preliminary sequence analysis of epiplasmins, the major constituent of the membrane skeleton of Paramecium.

    Science.gov (United States)

    Coffe, G; Le Caer, J P; Lima, O; Adoutte, A

    1996-01-01

    The epiplasmic layer, a continuous rigid granulo-fibrillar sheet directly subtending the surface membranes of Paramecium, is one of the outermost of the various cytoskeletal networks that compose it cortex. We have previously shown that the epiplasm consists of a set of 30 to 50 protein bands on SDS-PAGE in the range 50 to 33 kDa, the epiplasmins. We report a purification procedure for the set of epiplasmic proteins, a description of their physicochemical and reassembly properties, and a preliminary characterization of their sequence. The conditions for solubilization of the epiplasm and for in vitro reassembly of its purified constituents ar described. Reassembly of the entire set of proteins and of some (but not all) subsets are shown to yield filamentous aggregates. Microsequences of two purified bands of epiplasmins reveal a striking amino acid sequence consisting of heptad repeats of only three main amino acids, P, V, and Q. These repeats were confirmed by DNA sequencing of polymerase chain reaction products. The motif is QPVQ-h, in which h is a hydrophobic residue. This may constitute the core of the epiplasmin sequence and, in view of the tendency of such a sequence to form a coiled-coil, may account for the remarkable self-aggregation properties of epiplasmins.

  19. Paramecium tetraurelia growth stimulation under low-level chronic irradiation: investigations on a possible mechanism. [/sup 60/Co

    Energy Technology Data Exchange (ETDEWEB)

    Croute, F.; Soleilhavoup, J.P.; Vidal, S.; Dupouy, D.; Planel, H.

    1982-12-01

    Experiments were carried out to demonstrate the effects of low-level chronic irradiation on Paramecium tetraurelia proliferation. Biological effects were strongly dependent on the bacterial density of culture medium and more exactly on the catalase content of the medium. Significant growth stimulation was found under /sup 60/Co chronic irradiation at a dose rate of 2 rad/year when paramecia were grown in a medium containing a high bacterial concentration (2.5 x 10/sup 2/ cells/m) or supplemented with catalase (300 U/ml). In a medium with a low bacterial density (1 x 10/sup 6/ cell/ml) or supplemented with a catalase activity inhibitor, growth simulation was preceded by a transitory inhibiting effect which could be correlated with extracellularly radioproduced H/sub 2/O/sub 2/. H/sub 2/O/sub 2/ addition appeared to be able to simulate the biological effects of chronic irradiation. A possible mechanism is discussed.We proposed that the stimulating effects were the result of intracellular enzymatic scavenging of radioproduced H/sub 2/O/sub 2/.

  20. Stage-specific appearance of cytoplasmic microtubules around the surviving nuclei during the third prezygotic division of Paramecium

    Institute of Scientific and Technical Information of China (English)

    Yiwen WANG; Jinqiang YUAN; Xin GAO; Xianyu YANG

    2012-01-01

    There are six micronuclear divisions during conjugation of Paramecium caudatum: three prezygotic and three postzygotic divisions.Four haploid nuclei are formed during the first two meiotic prezygotic divisions.Usually only one meiotic product is located in the paroral cone (PC) region at the completion of meiosis,which survives and divides mitotically to complete the third prezygotic division to yield a stationary and a migratory pronucleus.The remaining three located outside of the PC degenerate.The migratory pronuclei are then exchanged between two conjugants and fuse with the stationary pronuclei to form synkarya,which undergo three successive divisions (postzygotic divisions).However,little is known about the surviving mechanism of the PC nuclei.In the current study,stage-specific appearance of cytoplasmic microtubules (cMTs) was indicated during the third prezygotic division by immunofluorescence labeling with anti-alpha tubulin antibodies surrounding the surviving nuclei,including the PC nuclei and the two types of prospective pronuclei.This suggested that cMTs were involved in the formation of a physical barrier,whose function may relate to sequestering and protecting the surviving nuclei from the major cytoplasm,where degeneration of extra-meiotic products occurs,another important nuclear event during the third prezygotic division.

  1. Dipeptides from the red alga Acanthopora spicifera

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; DeSouza, L.; Kamat, S.Y.

    An investigation of red alga Acanthophora spicifera afforded the known peptide, aurantiamide acetate and a new diastereoisomer of this dipeptide (dia-aurantiamide acetate). This is a first report of aurantiamide acetate from a marine source...

  2. 2011 Biomass Program Platform Peer Review: Algae

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Joyce [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Algae Platform Review meeting.

  3. THE SOIL ALGAE OF CIBODAS FOREST RESERVE

    Directory of Open Access Journals (Sweden)

    Anne Johnson

    2014-01-01

    Full Text Available Three species of green algae and one blue-green alga were recorded from eight samples of soil found associated with bryophytes in the Cibodas Forest Reserve. Chemical analysis of the soil showed severe leaching of soluable mineral substances associated with a low pH. The low light intensity under forest conditions and the low pH may account for the limited algal flora.

  4. Antioxidant Activity of Hawaiian Marine Algae

    Directory of Open Access Journals (Sweden)

    Anthony D. Wright

    2012-02-01

    Full Text Available Marine algae are known to contain a wide variety of bioactive compounds, many of which have commercial applications in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. Natural antioxidants, found in many algae, are important bioactive compounds that play an important role against various diseases and ageing processes through protection of cells from oxidative damage. In this respect, relatively little is known about the bioactivity of Hawaiian algae that could be a potential natural source of such antioxidants. The total antioxidant activity of organic extracts of 37 algal samples, comprising of 30 species of Hawaiian algae from 27 different genera was determined. The activity was determined by employing the FRAP (Ferric Reducing Antioxidant Power assays. Of the algae tested, the extract of Turbinaria ornata was found to be the most active. Bioassay-guided fractionation of this extract led to the isolation of a variety of different carotenoids as the active principles. The major bioactive antioxidant compound was identified as the carotenoid fucoxanthin. These results show, for the first time, that numerous Hawaiian algae exhibit significant antioxidant activity, a property that could lead to their application in one of many useful healthcare or related products as well as in chemoprevention of a variety of diseases including cancer.

  5. Evolution of the α-Subunit of Na/K-ATPase from Paramecium to Homo sapiens: Invariance of Transmembrane Helix Topology.

    Science.gov (United States)

    Morrill, Gene A; Kostellow, Adele B; Liu, Lijun; Gupta, Raj K; Askari, Amir

    2016-05-01

    Na/K-ATPase is a key plasma membrane enzyme involved in cell signaling, volume regulation, and maintenance of electrochemical gradients. The α-subunit, central to these functions, belongs to a large family of P-type ATPases. Differences in transmembrane (TM) helix topology, sequence homology, helix-helix contacts, cell signaling, and protein domains of Na/K-ATPase α-subunit were compared in fungi (Beauveria), unicellular organisms (Paramecia), primitive multicellular organisms (Hydra), and vertebrates (Xenopus, Homo sapiens), and correlated with evolution of physiological functions in the α-subunit. All α-subunits are of similar length, with groupings of four and six helices in the N- and C-terminal regions, respectively. Minimal homology was seen for protein domain patterns in Paramecium and Hydra, with high correlation between Hydra and vertebrates. Paramecium α-subunits display extensive disorder, with minimal helix contacts. Increases in helix contacts in Hydra approached vertebrates. Protein motifs known to be associated with membrane lipid rafts and cell signaling reveal significant positional shifts between Paramecium and Hydra vulgaris, indicating that regional membrane fluidity changes occur during evolution. Putative steroid binding sites overlapping TM-3 occurred in all species. Sites associated with G-protein-receptor stimulation occur both in vertebrates and amphibia but not in Hydra or Paramecia. The C-terminus moiety "KETYY," necessary for the Na(+) activation of pump phosphorylation, is not present in unicellular species indicating the absence of classical Na(+)/K(+)-pumps. The basic protein topology evolved earliest, followed by increases in protein domains and ordered helical arrays, correlated with appearance of α-subunit regions known to involve cell signaling, membrane recycling, and ion channel formation.

  6. 草履虫毒性实验的研究进展%Research Development of the Toxicity Text to Paramecium

    Institute of Scientific and Technical Information of China (English)

    焦迪

    2012-01-01

    This text reviewed the toxicity text of the heavy metal ions and pesticides to Paramecium, for protection of the ecological environment to provide valuable material. And recommendations for the future research work.%综述了重金属离子和农药对草履虫的毒性实验的研究现状,为保护生态环境提供有价值的参考资料.并对今后草履虫毒性实验的研究工作提出了建议.

  7. Algae production for energy and foddering

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Attila; Jobbagy, Peter; Durko, Emilia [University of Debrecen, Faculty of Applied Economics and Rural Development (UD-FAERD), Centre for Agricultural and Applied Economic Sciences, Debrecen (Hungary)

    2011-09-15

    This study not only presents the results of our own experiments in alga production, but also shows the expected economic results of the various uses of algae (animal feed, direct burning, pelleting, bio-diesel production), the technical characteristics of a new pelleting method based on literature, and also our own recommended alga production technology. In our opinion, the most promising alternative could be the production of alga species with high levels of oil content, which are suitable for utilization as by-products for animal feed and in the production of bio-diesel, as well as for use in waste water management and as a flue gas additive. Based on the data from our laboratory experiments, of the four species we analyzed, Chlorella vulgaris should be considered the most promising species for use in large-scale experiments. Taking expenses into account, our results demonstrate that the use of algae for burning technology purposes results in a significant loss under the current economic conditions; however, the utilization of algae for feeding and bio-diesel purposes - in spite of their innovative nature - is nearing the level needed for competitiveness. By using the alga production technology recommended by us and described in the present study in detail, with an investment of 545 to 727 thousand EUR/ha, this technology should be able to achieve approximately 0-29 thousand EUR/ha net income, depending on size. More favorable values emerge in the case of the 1-ha (larger) size, thanks to the significant savings on fixed costs (depreciation and personnel costs). (orig.)

  8. Algae Biofuel in the Nigerian Energy Context

    Directory of Open Access Journals (Sweden)

    Elegbede Isa

    2016-05-01

    Full Text Available The issue of energy consumption is one of the issues that have significantly become recognized as an important topic of global discourse. Fossil fuels production reportedly experiencing a gradual depletion in the oil-producing nations of the world. Most studies have relatively focused on biofuel development and adoption, however, the awareness of a prospect in the commercial cultivation of algae having potential to create economic boost in Nigeria, inspired this research. This study aims at exploring the potential of the commercialization of a different but commonly found organism, algae, in Nigeria. Here, parameters such as; water quality, light, carbon, average temperature required for the growth of algae, and additional beneficial nutrients found in algae were analysed. A comparative cum qualitative review of analysis was used as the study made use of empirical findings on the work as well as the author’s deductions. The research explored the cultivation of algae with the two major seasonal differences (i.e. rainy and dry in Nigeria as a backdrop. The results indicated that there was no significant difference in the contribution of algae and other sources of biofuels as a necessity for bioenergy in Nigeria. However, for an effective sustainability of this prospect, adequate measures need to be put in place in form of funding, provision of an economically-enabling environment for the cultivation process as well as proper healthcare service in the face of possible health hazard from technological processes. Further studies can seek to expand on the potential of cultivating algae in the Harmattan season.

  9. Biological toxicity of lanthanide elements on algae.

    Science.gov (United States)

    Tai, Peidong; Zhao, Qing; Su, Dan; Li, Peijun; Stagnitti, Frank

    2010-08-01

    The biological toxicity of lanthanides on marine monocellular algae was investigated. The specific objective of this research was to establish the relationship between the abundance in the seawater of lanthanides and their biological toxicities on marine monocellular algae. The results showed that all single lanthanides had similar toxic effects on Skeletonema costatum. High concentrations of lanthanides (29.04+/-0.61 micromol L(-1)) resulted in 50% reduction in growth of algae compared to the controls (0 micromol L(-1)) after 96 h (96 h-EC50). The biological toxicity of 13 lanthanides on marine monocellular algae was unrelated with the abundance of different lanthanide elements in nature, and the "Harkins rule" was not appropriate for the lanthanides. A mixed solution that contained equivalent concentrations of each lanthanide element had the same inhibition effect on algae cells as each individual lanthanide element at the same total concentration. This phenomenon is unique compared to the groups of other elements in the periodic table. Hence, we speculate that the monocellular organisms might not be able to sufficiently differentiate between the almost chemically identical lanthanide elements.

  10. Oil from algae; salvation from peak oil?

    Science.gov (United States)

    Rhodes, Christopher J

    2009-01-01

    A review is presented of the use of algae principally to produce biodiesel fuel, as a replacement for conventional fuel derived from petroleum. The imperative for such a strategy is that cheap supplies of crude oil will begin to wane within a decade and land-based crops cannot provide more than a small amount of the fuel the world currently uses, even if food production were allowed to be severely compromised. For comparison, if one tonne of biodiesel might be produced say, from rape-seed per hectare, that same area of land might ideally yield 100 tonnes of biodiesel grown from algae. Placed into perspective, the entire world annual petroleum demand which is now provided for by 31 billion barrels of crude oil might instead be met from algae grown on an area equivalent to 4% of that of the United States. As an additional benefit, in contrast to growing crops it is not necessary to use arable land, since pond-systems might be placed anywhere, even in deserts, and since algae grow well on saline water or wastewaters, no additional burden is imposed on freshwater-a significant advantage, as water shortages threaten. Algae offer the further promise that they might provide future food supplies, beyond what can be offered by land-based agriculture to a rising global population.

  11. Coping with temperature at the warm edge--patterns of thermal adaptation in the microbial eukaryote Paramecium caudatum.

    Directory of Open Access Journals (Sweden)

    Sascha Krenek

    Full Text Available BACKGROUND: Ectothermic organisms are thought to be severely affected by global warming since their physiological performance is directly dependent on temperature. Latitudinal and temporal variations in mean temperatures force ectotherms to adapt to these complex environmental conditions. Studies investigating current patterns of thermal adaptation among populations of different latitudes allow a prediction of the potential impact of prospective increases in environmental temperatures on their fitness. METHODOLOGY/PRINCIPAL FINDINGS: In this study, temperature reaction norms were ascertained among 18 genetically defined, natural clones of the microbial eukaryote Paramecium caudatum. These different clones have been isolated from 12 freshwater habitats along a latitudinal transect in Europe and from 3 tropical habitats (Indonesia. The sensitivity to increasing temperatures was estimated through the analysis of clone specific thermal tolerances and by relating those to current and predicted temperature data of their natural habitats. All investigated European clones seem to be thermal generalists with a broad thermal tolerance and similar optimum temperatures. The weak or missing co-variation of thermal tolerance with latitude does not imply local adaptation to thermal gradients; it rather suggests adaptive phenotypic plasticity among the whole European subpopulation. The tested Indonesian clones appear to be locally adapted to the less variable, tropical temperature regime and show higher tolerance limits, but lower tolerance breadths. CONCLUSIONS/SIGNIFICANCE: Due to the lack of local temperature adaptation within the European subpopulation, P. caudatum genotypes at the most southern edge of their geographic range seem to suffer from the predicted increase in magnitude and frequency of summer heat waves caused by climate change.

  12. Complementary specificity of restriction endonucleases of Diplococcus pneumoniae with respect to DNA methylation. [Haemophilus influenzae, Escherichia coli, Paramecium aurelia

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.; Greenberg, B.

    1977-01-01

    Restriction endonucleases Dpn I and Dpn II are produced by two distinct strains of Diplococcus pneumoniae. The two enzymes show complementary specificity with respect to methylation of sites in DNA. From the identity of its cleavage site with that of Mbo I, it appears that Dpn II cleaves at the unmodified sequence 5'-G-A-T-C-3'. Dpn I cleaves at the same sequence when the adenine residue is methylated. Both enzymes produce only double-strand breaks in susceptible DNA. Their susceptibility to Dpn I and not Dpn II shows that essentially all the G-A-T-C sequences are methylated in DNA from the pneumococcal strain that produces Dpn II as well as in DNA from Hemophilus influenzae and Escherichia coli. In the dam-3 mutant of E. coli none of these sequences appear to be methylated. Residual adenine methylation in the dam-3 mutant DNA most likely occurs at different sites. Different but characteristic degrees of methylation at G-A-T-C sites are found in the DNA of bacterial viruses grown in E. coli. DNAs from mammalian cells and viruses are not methylated at this sequence. Mitochondrial DNA from Paramecium aurelia is not methylated, but a small proportion of G-A-T-C sequences in the macronuclear DNA of this eukaryote appear to be methylated. Possible roles of sequence-specific methylation in the accommodation of plasmids, in the replication of DNA, in the regulation of gene function and in the restriction of viral infection are discussed.

  13. “Candidatus Gortzia shahrazadis”, a novel endosymbiont of Paramecium multimicronucleatum and a revision of the biogeographical distribution of Holospora-like bacteria

    Directory of Open Access Journals (Sweden)

    Valentina Serra

    2016-11-01

    Full Text Available Holospora spp. and Candidatus Gortzia infectiva, known as Holospora-like bacteria (HLB, are commonly found as nuclear endosymbionts of ciliates, especially the Paramecium genus. HLB are related by phylogenetic relationships, morphological features, and life cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF. In this paper we describe a novel species belonging to the Ca. Gortzia genus, detected in P. multimicronucleatum, a ciliate for which infection by an HLB has not been reported, discovered in India. This novel endosymbiont shows unusual and surprising features with respect to other HLB, such as large variations in IF morphology and the occasional ability to reproduce in the host cytoplasm. We propose the name of Candidatus Gortzia shahrazadis for this novel HLB . Moreover, we report two additional species of HLB from Indian Paramecium populations: Ca. Gortzia infectiva (from P. jenningsi, and H. obtusa (from P. caudatum; the latter is the first record of Holospora from a tropical country. Although tropical, we retrieved H. obtusa at an elevation of 706 m. corresponding to a moderate climate not unlike conditions where Holospora are normally found, suggesting the genus Holospora does exist in tropical countries, but restricted to higher elevations.

  14. An ion-current mutant of Paramecium tetraurelia with defects in the primary structure and post-translational N-methylation of calmodulin

    Energy Technology Data Exchange (ETDEWEB)

    Wallen-Friedman, M.A.

    1988-01-01

    My work on pantophobiac A{sup 2} (pntA{sup 2}), a behavioral mutant of Paramecium tetraurelia, suggest that the Ca{sup ++}-binding protein calmodulin (CaM), and post-translation N-methylation of CaM, are important for Ca{sup ++}-related ion-current function. Calmodulin from wild-type Paramecium has two sites of lysine-N-methylation. Both of these sites are almost fully methylated in vivo; thus wild-type calmodulin is a poor substrate for N-methylation in vitro. In contrast, pntA/{sup 2} CaM can be heavily N-methylated in vitro, suggesting that the mutant calmodulin is under-methylated in vivo. Amino-acid composition analysis showed that CaM lysine 115 is undermethylated in pntA{sup 2}. Once pntA{sup 2} CaM is N-methylated, the (methyl-{sup 3}H) group does not turn over in either wild-type or pntA{sup 2} cytoplasmic fractions. The methylating enzymes in pntA{sup 2} high-speed supernatant fractions are active, but may be less robust than those of the wild type, suggesting a possible control of these enzymes by CaM.

  15. Freshwater algae of the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, W.D.; Giles, K.R.

    1979-06-01

    Fifty-two species of freshwater algae were identified in samples collected from the eight known natural springs of the Nevada Test Site. Although several species were widespread, 29 species were site specific. Diatoms provided the greatest variety of species at each spring. Three-fifths of all algal species encountered were diatoms. Well-developed mats of filamentous green algae (Chlorophyta) were common in many of the water tanks associated with the springs and accounted for most of the algal biomass. Major nutrients were adequate, if not abundant, in most spring waters - growth being limited primarily by light and physical habitat. There was some evidence of cesium-137 bioconcentration by algae at several of the springs.

  16. Algae a promising alternative for biofuel

    Directory of Open Access Journals (Sweden)

    M.H. Sayadi

    2011-08-01

    Full Text Available Research on renewable and environmentally friendly fuel is growing rapidly and many scientists and governments are interested to grow it fast due to limitation of conventional fuel sources and their harmful effects on the environment. Biofuels are not only the best and reliably available fuels attained from renewable sources which are environment friendly. Besdies biofuels are abundantly available in all the locations easily accessible and highly sustainable. In the present review, the authors present a brief highlight of challenges that necessitates to be covered in order to make both, micro as well as macro algae a viable option to produce renewable biofuels. It is interesting to note that algae are varied, pervasive, and productive and also having less impact with plants as a food for human and animals. Further research is required to a high quantity of product innovation because most dedicated algae are faced uneconomically high costs.

  17. Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, P.; Wang, J.; Li, X.; Zhu, J. E-mail: iamzhu@hotmail.com; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T

    2000-03-01

    Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd{sup 3+} by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 {mu}m size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores (<10 {mu}m) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation.

  18. Microspectroscopy of the photosynthetic compartment of algae.

    Science.gov (United States)

    Evangelista, Valtere; Frassanito, Anna Maria; Passarelli, Vincenzo; Barsanti, Laura; Gualtieri, Paolo

    2006-01-01

    We performed microspectroscopic evaluation of the pigment composition of the photosynthetic compartments of algae belonging to different taxonomic divisions and higher plants. The feasibility of microspectroscopy for discriminating among species and/or phylogenetic groups was tested on laboratory cultures. Gaussian bands decompositions and a fitting algorithm, together with fourth-derivative transformation of absorbance spectra, provided a reliable discrimination among chlorophylls a, b and c, phycobiliproteins and carotenoids. Comparative analysis of absorption spectra highlighted the evolutionary grouping of the algae into three main lineages in accordance with the most recent endosymbiotic theories.

  19. Serpins in plants and green algae

    DEFF Research Database (Denmark)

    Roberts, Thomas Hugh; Hejgaard, Jørn

    2008-01-01

    . Serpins have been found in diverse species of the plant kingdom and represent a distinct clade among serpins in multicellular organisms. Serpins are also found in green algae, but the evolutionary relationship between these serpins and those of plants remains unknown. Plant serpins are potent inhibitors...... of mammalian serine proteinases of the chymotrypsin family in vitro but, intriguingly, plants and green algae lack endogenous members of this proteinase family, the most common targets for animal serpins. An Arabidopsis serpin with a conserved reactive centre is now known to be capable of inhibiting...

  20. Foresight Brief: Seaweed & Algae as Biofuels Feedstocks

    OpenAIRE

    Institute, Marine

    2008-01-01

    Seaweed is a known potential carbon-dioxide (CO2) neutral source of second generation biofuels. When seaweed grows it absorbs CO2 from the atmosphere and this CO2 is released back to the atmosphere during combustion. What makes seaweed, and in particular micro algae, so promising as a fuel source is their growth rates and high lipid (oil) content. Algae are among the fastest-growing plants in the world. Energy is stored inside the cell as lipids and carbohydrates, and can be converted into fu...

  1. Association of thraustochytrids and fungi with living marine algae

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Nagarkar, S.; Raghukumar, S.

    only in C. clavulatum, Sargassum cinereum and Padina tetrastromatica whilst mycelial fungi occurred in all. Growth experiments in the laboratory indicated that the growth of thraustochytrids was inhibited on live algae, whereas killed algae supported...

  2. An Overview of Algae Biofuel Production and Potential Environmental Impact

    Science.gov (United States)

    Algae are among the most potentially significant sources of sustainable biofuels in the future of renewable energy. A feedstock with virtually unlimited applicability, algae can metabolize various waste streams (e.g., municipal wastewater, carbon dioxide from industrial flue gas)...

  3. Novel Fiber Optic Fluorometer for the Measurement of Alga Concentration

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A novel fluorometer based on fiber optics is briefly introduced for the measurement of alga concentration. Both the exciting light and the fluorescence from alga chlorophyll are transmitted along a fiber cable. By this way, we can get alga concentration by measuring its chlorophyll-a fluorescence intensity. The experiment results show that this instrument is characterized by good sensitivity, linearity and accuracy.

  4. Inventory of North-West European algae initiatives

    NARCIS (Netherlands)

    Spruijt, J.

    2015-01-01

    In 2012 an inventory of North-West European (NWE) algae initiatives was carried out to get an impression of the market and research activities on algae production and refinery, especially for bioenergy purposes. A questionnaire was developed that would provide the EnAlgae project with information on

  5. New methodologies for integrating algae with CO2 capture

    NARCIS (Netherlands)

    Hernandez Mireles, I.; Stel, R.W. van der; Goetheer, E.L.V.

    2014-01-01

    It is generally recognized, that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient fe

  6. How to Identify and Control Water Weeds and Algae.

    Science.gov (United States)

    Applied Biochemists, Inc., Mequon, WI.

    Included in this guide to water management are general descriptions of algae, toxic algae, weed problems in lakes, ponds, and canals, and general discussions of mechanical, biological and chemical control methods. In addition, pictures, descriptions, and recommended control methods are given for algae, 6 types of floating weeds, 18 types of…

  7. 21 CFR 73.185 - Haematococcus algae meal.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Haematococcus algae meal. 73.185 Section 73.185... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.185 Haematococcus algae meal. (a) Identity. (1) The color additive haematococcus algae meal consists of the comminuted and dried cells of the...

  8. Research and development for algae-based technologies in Korea: a review of algae biofuel production.

    Science.gov (United States)

    Hong, Ji Won; Jo, Seung-Woo; Yoon, Ho-Sung

    2015-03-01

    This review covers recent research and development (R&D) activities in the field of algae-based biofuels in Korea. As South Korea's energy policy paradigm has focused on the development of green energies, the government has funded several algae biofuel R&D consortia and pilot projects. Three major programs have been launched since 2009, and significant efforts are now being made to ensure a sustainable supply of algae-based biofuels. If these R&D projects are executed as planned for the next 10 years, they will enable us to overcome many technical barriers in algae biofuel technologies and help Korea to become one of the leading countries in green energy by 2020.

  9. Fucoidans - sulfated polysaccharides of brown algae

    Energy Technology Data Exchange (ETDEWEB)

    Usov, Anatolii I; Bilan, M I [N.D.Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    2009-08-31

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  10. Fucoidans — sulfated polysaccharides of brown algae

    Science.gov (United States)

    Usov, Anatolii I.; Bilan, M. I.

    2009-08-01

    The methods of isolation of fucoidans and determination of their chemical structures are reviewed. The fucoidans represent sulfated polysaccharides of brown algae, the composition of which varies from simple fucan sulfates to complex heteropolysaccharides. The currently known structures of such biopolymers are presented. A variety of the biological activities of fucoidans is briefly summarised.

  11. Pheromone signaling during sexual reproduction in algae.

    Science.gov (United States)

    Frenkel, Johannes; Vyverman, Wim; Pohnert, Georg

    2014-08-01

    Algae are found in all aquatic and many terrestrial habitats. They are dominant in phytoplankton and biofilms thereby contributing massively to global primary production. Since algae comprise photosynthetic representatives of the various protoctist groups their physiology and appearance is highly diverse. This diversity is also mirrored in their characteristic life cycles that exhibit various facets of ploidy and duration of the asexual phase as well as gamete morphology. Nevertheless, sexual reproduction in unicellular and colonial algae usually has as common motive that two specialized, sexually compatible haploid gametes establish physical contact and fuse. To guarantee mating success, processes during sexual reproduction are highly synchronized and regulated. This review focuses on sex pheromones of algae that play a key role in these processes. Especially, the diversity of sexual strategies as well as of the compounds involved are the focus of this contribution. Discoveries connected to algal pheromone chemistry shed light on the role of key evolutionary processes, including endosymbiotic events and lateral gene transfer, speciation and adaptation at all phylogenetic levels. But progress in this field might also in the future provide valid tools for the manipulation of aquaculture and environmental processes.

  12. Spirulina: The Alga That Can End Malnutrition.

    Science.gov (United States)

    Fox, Ripley D.

    1985-01-01

    One approach to eliminating malnutrition worldwide is to grow spirulina in recycled village wastes. Spirulina is a blue-green alga and a natural concentrated food. Spirulina can give poor villages a nutritional food supplement they can grow themselves and can reduce infectious disease at the same time. (Author/RM)

  13. Research for Developing Renewable Biofuels from Algae

    Energy Technology Data Exchange (ETDEWEB)

    Black, Paul N. [Univ. of Nebraska, Lincoln, NE (United States)

    2012-12-15

    Task A. Expansion of knowledge related to lipid production and secretion in algae A.1 Lipid biosynthesis in target algal species; Systems biology approaches are being used in combination with recent advances in Chlorella and Chlamydomonas genomics to address lipid accumulation in response to defined nutrient regimes. The UNL Algal Group continues screening additional species of Chlorella and other naturally occurring algae for those with optimal triglyceride production; Of the strains examined by the DOE's Aquatic Species Program, green algae, several species of Chlorella represent the largest group from which oleaginous candidates have been identified; A.1.1. Lipid profiling; Neutral lipid accumulation is routinely monitored by Nile red and BODIPY staining using high throughput strategies to screen for naturally occurring algae that accumulate triglyceride. These strategies complement those using spectrofluorometry to quantify lipid accumulation; Neutral lipid accumulation is routinely monitored by high performance thin-layer chromatography (HPTLC) and high performance liquid chromatography (HPLC) of lipid extracts in conjunction with; Carbon portioning experiments have been completed and the data currently are being analyzed and prepared for publication; Methods in the Black lab were developed to identify and quantify triacylglycerol (TAG), major membrane lipids [diacylglycerol trimethylhomoserine, phosphatidylethanolamine and chloroplast glycolipids], biosynthetic intermediates such as diacylglycerol, phosphatidic acid and lysophospholipids and different species of acyl-coenzyme A (acyl CoA).

  14. Bromophenols in Marine Algae and Their Bioactivities

    DEFF Research Database (Denmark)

    Ming, Liu; Hansen, Poul Erik; Lin, Xiukun

    2011-01-01

    Marine algae contain various bromophenols that have been shown to possess a variety of biological activities, including antioxidant, antimicrobial, anticancer, anti-diabetic, and anti-thrombotic effects. Here, we briefly review the recent progress of these marine algal biomaterials, with respect...

  15. Isolation of glycoproteins from brown algae

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

  16. Design your own Algae Photobioreactor Facade

    NARCIS (Netherlands)

    Juarez Ortiz, T.V.; Choi, Z.F.

    2014-01-01

    This "designers' manual" is made during the TIDO-course AR0533 Innovation & Sustainability. There are several reasons why to implement algae in the building facade. Imagine our future buildings covered with photosynthetic skins and vertical gardens, collecting the sun’s energy and making buildings

  17. THE USE OF ALGAE CONCENTRATES, DRIED ALGAE AND ALGAL SUBSTITUTES TO FEED BIVALVES

    Directory of Open Access Journals (Sweden)

    Ludi Parwadani Aji

    2011-01-01

    Full Text Available Microalgae have high nutritional value and are used to feed adult and larval stages of bivalves, the larvae of some fish and crustaceans and zooplankton. However, microalgae production for aquaculture animal is very expensive. To overcome this, the use of preserved microalgae such as algae concentrate and dried algae, or algal substitutes has been developed. There are both advantages and disadvantages to this alternative food. For example, even though the cost production for algal substitute yeast-based diet is cheaper, their nutritional value is much lower compared to fresh microalgae. Moreover, there is no significant difference in nutritional value between preserved (concentrated or dried and fresh microalgae; however, preserving microalgae for long periods will affect their nutritional value. In spite of this problem, preserved microalgae such as algal concentrate and dried algae seem to be more effective to feed bivalves than algal substitutes yeast based diet due to their availability and relatively high nutritional value. Furthermore, algae concentrates are more suitable to replace fresh algae than dried algae.

  18. Componentes funcionales en aceites de pescado y de alga Functional components in fish and algae oils

    Directory of Open Access Journals (Sweden)

    A. Conchillo

    2006-06-01

    Full Text Available Buena parte del desarrollo de nuevos alimentos funcionales está encaminada al descubrimiento o aplicación de componentes de los alimentos que favorezcan la instauración de un perfil lipídico saludable en el organismo. El objetivo del trabajo fue realizar la caracterización de la fracción lipídica de dos tipos de aceites, de pescado y de alga, para valorar su potencial utilización como ingredientes funcionales, tanto en relación con el contenido en ácidos grasos de alto peso molecular como con la presencia de esteroles y otros componentes de la fracción insaponificable. Ambos aceites presentaron una fracción lipídica muy rica en ácidos grasos poliinsaturados ω-3 de alto peso molecular, con un 33,75% en el caso del aceite de pescado y un 43,97% en el de alga, siendo el EPA el ácido graso mayoritario en el pescado y el DHA en el alga. La relación ω-6/ω-3 fue en ambos aceites inferior a 0,4. En cuanto a la fracciσn insaponificable, el aceite de alga presentσ un contenido 3 veces menor de colesterol y una mayor proporciσn de escualeno. El contenido en fitosteroles fue significativamente superior en el aceite de alga.An important area of the development of new functional foods is facussed on finding or applying food components which favour achieving a healthier lipid profile in the organism. The objective of this work was to carry out the characterisation of the lipid fraction of two oils, fish oil and algae oil, to evaluate their potential use as functional ingredients, in relation to the high molecular weight fatty acid content and the presence of sterols and other components of the unsaponificable fraction. Both oils showed a lipid fraction rich in high molecular weight polyunsaturated ω-3 fatty acids, containing a 33.75% in the fish oil and a 43.97% in the algae oil. Eicosapentaenoic acid was the major fatty acid in fish oil, whereas docosahexaenoic was the most abundant fatty acid in algae oil. The ω-6/ω-3 ratio was lower

  19. Photodegradation of Norfloxacin in aqueous solution containing algae

    Institute of Scientific and Technical Information of China (English)

    Junwei Zhang; Dafang Fu; Jilong Wu

    2012-01-01

    Photodegradation of Norfloxacin in aqueous solution containing algae under a medium pressure mercury lamp (15 W,λmax =365 nm) was investigated.Results indicated that the photodegradation of Norfloxacin could be induced by the algae in the heterogeneous algaewater systems.The photodegradation rate of Norfloxacin increased with increasing algae concentration,and was greatly influenced by the temperature and pH of solution.Meanwhile,the cooperation action of algae and Fe(Ⅲ),and the ultrasound were beneficial to photodegradation of Norfloxaciu.The degradation kinetics of Norfloxacin was found to follow the pseudo zero-order reaction in the suspension of algae.In addition,we discussed the photodegradation mechanism of Norfloxacin in the suspension of algae.This work will be helpful for understanding the photochemical degradation of antibiotics in aqueous environment in the presence of algae,for providing a new method to deal with antibiotics pollution.

  20. Microdomain Ca2+ Activation during Exocytosis in Paramecium Cells. Superposition of Local Subplasmalemmal Calcium Store Activation by Local Ca2+ Influx

    Science.gov (United States)

    Erxleben, Christian; Klauke, Norbert; Flötenmeyer, Matthias; Blanchard, Marie-Pierre; Braun, Claudia; Plattner, Helmut

    1997-01-01

    In Paramecium tetraurelia, polyamine-triggered exocytosis is accompanied by the activation of Ca2+-activated currents across the cell membrane (Erxleben, C., and H. Plattner. 1994. J. Cell Biol. 127:935– 945). We now show by voltage clamp and extracellular recordings that the product of current × time (As) closely parallels the number of exocytotic events. We suggest that Ca2+ mobilization from subplasmalemmal storage compartments, covering almost the entire cell surface, is a key event. In fact, after local stimulation, Ca2+ imaging with high time resolution reveals rapid, transient, local signals even when extracellular Ca2+ is quenched to or below resting intracellular Ca2+ concentration ([Ca2+]e ⩽ [Ca2+]i). Under these conditions, quenched-flow/freeze-fracture analysis shows that membrane fusion is only partially inhibited. Increasing [Ca2+]e alone, i.e., without secretagogue, causes rapid, strong cortical increase of [Ca2+]i but no exocytosis. In various cells, the ratio of maximal vs. minimal currents registered during maximal stimulation or single exocytotic events, respectively, correlate nicely with the number of Ca stores available. Since no quantal current steps could be observed, this is again compatible with the combined occurrence of Ca2+ mobilization from stores (providing close to threshold Ca2+ levels) and Ca2+ influx from the medium (which per se does not cause exocytosis). This implies that only the combination of Ca2+ flushes, primarily from internal and secondarily from external sources, can produce a signal triggering rapid, local exocytotic responses, as requested for Paramecium defense. PMID:9024690

  1. Algae-Derived Dietary Ingredients Nourish Animals

    Science.gov (United States)

    2015-01-01

    In the 1980s, Columbia, Maryland-based Martek Biosciences Corporation worked with Ames Research Center to pioneer the use of microalgae as a source of essential omega-3 fatty acids, work that led the company to develop its highly successful Formulaid product. Now the Nutritional Products Division of Royal DSM, the company also manufactures DHAgold, a nutritional supplement for pets, livestock and farm-raised fish that uses algae to deliver docosahexaenoic acid (DHA).

  2. Cytoskeleton and Early Development in Fucoid Algae

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Cell polarization and asymmetric cell divisions play important roles during development in many multicellular eukaryotes.Fucoid algae have a long history as models for studying early developmental processes, probably because of the ease with which zygotes can be observed and manipulated in the laboratory. This review discusses cell polarization and asymmetric cell divisions in fucoid algal zygotes with an emphasis on the roles played by the cytoskeleton.

  3. Flavonoids from the Red Alga Acanthophora spicifera

    Institute of Scientific and Technical Information of China (English)

    ZENG Long-Mei(曾陇梅); 曾陇梅; WANG Chao-Jie(王超杰); 王超杰; SU Jing-Yu(苏镜娱); 苏镜娱; LI Du(李笃); 李笃; OWEN Noel L.; OWEN Noel L; LU Yang(吕扬); 吕扬; LU Nan(鲁南); 鲁南; ZHENG Qi-Tai(郑启泰); 郑启泰

    2001-01-01

    Two new flavonoids, acanthophorin A (1) and acanthophorin B (2), along with three known compounds tiliroside (3),( - )-catechin (4) and quercetin (5) were isolated from the red alga Acanthophora spicifera. The structures of 1 and 2were determined to be kaempferol 3-O-α-L-fucopyranoside (1) and quercetin 3-O-α-L-fucopyranoside (2) by spectroscopic methods. Both 1 and 2 showed significant anfioxidant activity.

  4. Selenium Uptake and Volatilization by Marine Algae

    Science.gov (United States)

    Luxem, Katja E.; Vriens, Bas; Wagner, Bettina; Behra, Renata; Winkel, Lenny H. E.

    2015-04-01

    Selenium (Se) is an essential trace nutrient for humans. An estimated one half to one billion people worldwide suffer from Se deficiency, which is due to low concentrations and bioavailability of Se in soils where crops are grown. It has been hypothesized that more than half of the atmospheric Se deposition to soils is derived from the marine system, where microorganisms methylate and volatilize Se. Based on model results from the late 1980s, the atmospheric flux of these biogenic volatile Se compounds is around 9 Gt/year, with two thirds coming from the marine biosphere. Algae, fungi, and bacteria are known to methylate Se. Although algal Se uptake, metabolism, and methylation influence the speciation and bioavailability of Se in the oceans, these processes have not been quantified under environmentally relevant conditions and are likely to differ among organisms. Therefore, we are investigating the uptake and methylation of the two main inorganic Se species (selenate and selenite) by three globally relevant microalgae: Phaeocystis globosa, the coccolithophorid Emiliania huxleyi, and the diatom Thalassiosira oceanica. Selenium uptake and methylation were quantified in a batch experiment, where parallel gas-tight microcosms in a climate chamber were coupled to a gas-trapping system. For E. huxleyi, selenite uptake was strongly dependent on aqueous phosphate concentrations, which agrees with prior evidence that selenite uptake by phosphate transporters is a significant Se source for marine algae. Selenate uptake was much lower than selenite uptake. The most important volatile Se compounds produced were dimethyl selenide, dimethyl diselenide, and dimethyl selenyl sulfide. Production rates of volatile Se species were larger with increasing intracellular Se concentration and in the decline phase of the alga. Similar experiments are being carried out with P. globosa and T. oceanica. Our results indicate that marine algae are important for the global cycling of Se

  5. [Pharmacology and toxicology of Spirulina alga].

    Science.gov (United States)

    Chamorro, G; Salazar, M; Favila, L; Bourges, H

    1996-01-01

    Spirulina, a unicellular filamentous blue-green alga has been consumed by man since ancient times in Mexico and central Africa. It is currently grown in many countries by synthetic methods. Initially the interest in Spirulina was on its nutritive value: it was found almost equal to other plant proteins. More recently, some preclinical testing suggests it has several therapeutic properties such as hypocholesterolemic, immunological, antiviral and antimutagenic. This has led to more detailed evaluations such as nucleic acid content and presence of toxic metals, biogenic toxins and organic chemicals: they have shown absence or presence at tolerable levels according to the recommendations of international regulatory agencies. In animal experiments for acute, subchronic and chronic toxicity, reproduction, mutagenicity, and teratogenicity the algae did not cause body or organ toxicity. In all instances, the Spirulina administered to the animals were at much higher amounts than those expected for human consumption. On the other hand there is scant information of the effects of the algae in humans. This area needs more research.

  6. Screening for bioactive compounds from algae.

    Science.gov (United States)

    Plaza, M; Santoyo, S; Jaime, L; García-Blairsy Reina, G; Herrero, M; Señoráns, F J; Ibáñez, E

    2010-01-20

    In the present work, a comprehensive methodology to carry out the screening for novel natural functional compounds is presented. To do that, a new strategy has been developed including the use of unexplored natural sources (i.e., algae and microalgae) together with environmentally clean extraction techniques and advanced analytical tools. The developed procedure allows also estimating the functional activities of the different extracts obtained and even more important, to correlate these activities with their particular chemical composition. By applying this methodology it has been possible to carry out the screening for bioactive compounds in the algae Himanthalia elongata and the microalgae Synechocystis sp. Both algae produced active extracts in terms of both antioxidant and antimicrobial activity. The obtained pressurized liquid extracts were chemically characterized by GC-MS and HPLC-DAD. Different fatty acids and volatile compounds with antimicrobial activity were identified, such as phytol, fucosterol, neophytadiene or palmitic, palmitoleic and oleic acids. Based on the results obtained, ethanol was selected as the most appropriate solvent to extract this kind of compounds from the natural sources studied.

  7. Environmental life cycle comparison of algae to other bioenergy feedstocks.

    Science.gov (United States)

    Clarens, Andres F; Resurreccion, Eleazer P; White, Mark A; Colosi, Lisa M

    2010-03-01

    Algae are an attractive source of biomass energy since they do not compete with food crops and have higher energy yields per area than terrestrial crops. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from a life cycle perspective. In this work, the impacts associated with algae production were determined using a stochastic life cycle model and compared with switchgrass, canola, and corn farming. The results indicate that these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location. Only in total land use and eutrophication potential do algae perform favorably. The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO(2) and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae. To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus. Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops.

  8. Electro-coagulation-flotation process for algae removal.

    Science.gov (United States)

    Gao, Shanshan; Yang, Jixian; Tian, Jiayu; Ma, Fang; Tu, Gang; Du, Maoan

    2010-05-15

    Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation-flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal parameters determined were: current density=1 mA/cm(2), pH=4-7, water temperature=18-36 degrees C, algae density=0.55 x 10(9)-1.55 x 10(9) cells/L. Under the optimal conditions, 100% of algae removal was achieved with the energy consumption as low as 0.4 kWh/m(3). The ECF performed well in acid and neutral conditions. At low initial pH of 4-7, the cell density of algae was effectively removed in the ECF, mainly through the charge neutralization mechanism; while the algae removal worsened when the pH increased (7-10), and the main mechanism shifted to sweeping flocculation and enmeshment. The mechanisms for algae removal at different pH were also confirmed by atomic force microscopy (AFM) analysis. Furthermore, initial cell density and water temperature could also influence the algae removal. Overall, the results indicated that the ECF technology was effective for algae removal, from both the technical and economical points of view.

  9. Functional and fluorochrome analysis of an exocytotic mutant yields evidence of store-operated Ca2+ influx in Paramecium.

    Science.gov (United States)

    Mohamed, I; Klauke, N; Hentschel, J; Cohen, J; Plattner, H

    2002-05-01

    A non-discharge mutant of Paramecium tetraurelia (nd12-35 degrees C, lacking exocytotic response upon stimulation with the nonpermeable polycationic secretagogue aminoethyldextran, AED), in the pawnA genetic context (d4-500r, lacking ciliary voltage-dependent Ca2+ influx), was shown to lack (45)Ca2+ entry from outside upon AED stimulation. In contrast, cells grown at 25 degrees C behave like the wildtype. To check the functional properties in more detail, fluorochrome-loaded 35 degrees C cells were stimulated, not only with AED (EC(100) = 10(-6) M in wildtype cells), but also with 4-chloro-meta-cresol, (4CmC, 0.5 mM), a permeable activator of ryanodine receptor-type Ca2+ release channels, usually at extracellular [Ca2+] of 50 microM, and eventually with a Ca2+ chelator added. We confirm that pwA-nd12(35 degrees C) cells lack any Ca2+ influx and any exocytosis of trichocysts in response to any stimulus. As we determined by x-ray microanalysis, total calcium content in alveolar sacs (subplasmalemmal stores) known to be mobilized upon exocytosis stimulation in wild-type cells, contain about the same total calcium in 35 degrees C as in 25 degrees C cells, and Ca2+ mobilization from alveoli by AED or 4CmC is also nearly the same. Due to the absence of any AED-induced Ca2+ influx in 35 degrees C cells and normal Ca2+ release from stores found by x-ray microanalysis one can exclude a "CICR"-type mechanism (Ca2+-induced Ca2+ release) and imply that normally a store-operated Ca2+ ("SOC") influx would occur (as in 25 degrees C cells). Furthermore, 35 degrees C cells display a significantly lower basal intracellular [Ca2+], so that any increase upon stimulation may be less expressed or even remain undetected. Under these conditions, any mobilization of Ca2+ from stores cannot compensate for the lack of Ca2+ influx, particularly since normally both components have to cooperate to achieve full exocytotic response. Also striking is our finding that 35 degrees C cells are unable

  10. Eradication of algae in ships' ballast water by electrolyzing

    Institute of Scientific and Technical Information of China (English)

    DANG Kun; SUN Pei-ting; XIAO Jing-kun; SONG Yong-xin

    2006-01-01

    In order to verify the effectiveness of electrolytic treatment on ships' ballast water,experiments are carried out by a pilot system in laboratory. The raw seawater and seawater with different concentrations of different algae are simulated as ships' ballast water. The algae in the raw seawater can be killed if it is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L. If the seawater with one kind of algae (Nitzschia closterum, Dicrateria spp., or Pyramidomonnas sp.105cells/mL) is treated by electrolysis with an initial residual chlorine concentration of 5 mg/L, the alga can be sterilized. If the seawater with one kind of algae (Dunaliella sp., Platymonas or Chlorella spp.)is directly treated by electrolyzing with an initial residual chlorine concentration of 4 mg/L, the instant mortality changes with the concentration of different algae. However, after 72 hours, in all treated samples, there are no live algal cells found.

  11. Bromophenols from Marine Algae with Potential Anti-Diabetic Activities

    Institute of Scientific and Technical Information of China (English)

    LIN Xiukun; LIU Ming

    2012-01-01

    Marine algae contain various bromophenols with a variety of biological activities,including antimicrobial,anticancer,and anti-diabetic effects.Here,we briefly review the recent progress in researches on the biomaterials from marine algae,emphasizing the relationship between the structure and the potential anti-diabetic applications.Bromophenols from marine algae display their hyperglycemic effects by inhibiting the activities of protein tyrosine phosphatase 1B,α-glucosidase,as well as other mechanisms.

  12. Freshwater Cyanobacteria (Blue-Green Algae) Toxins: Isolation and Characterization

    Science.gov (United States)

    1989-01-15

    exclusively caused by strains of species that are members of the L division Cyanophyta , commonly called blue -green algae or cyanobacteria . Although...0 0 Lfl (NAD FRESHWATER CYANOBACTERIA ( BLUE -GREEN ALGAE ) TOXINS: ISOLATION AND CHARACTERIZATION ANNCUAL REPORT Wayne W. Carmichael Sarojini Bose...Frederick, Maryland 21701-5012 62770A 6277GA871 AA 378 11 TITLE &who* Secwn~y C11mrfaon) Freshwater Cyanobacteria ( blue -green algae ) Toxins: Isolation

  13. Effects of triphenyltin exposure on the red alga Eucheuma denticulatum

    OpenAIRE

    Rumampuk, Natalie D. C.; Grevo, Gerung S.; Rumengan, Inneke F. M.; Ohji, Madoka; Arai, Takaomi; Miyazaki, Nobuyuki

    2004-01-01

    Toxic effects of triphenyltin (TPT) on the marine alga Eucheuma denticulatum obtained from Nain Island, North Sulawesi, Indonesia have been examined in laboratory condition. The algal samples were first acclimated in laboratory prepared seawater for three days. The algae were then divided into 12 culture chambers for treatments with different concentrations of TPT between 5-30 μgl^ with 5μgl^ interval, and in another container for control. After two-week experimentation, some samples of algae...

  14. Method and apparatus for iterative lysis and extraction of algae

    Energy Technology Data Exchange (ETDEWEB)

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  15. Overall Energy Considerations for Algae Species Comparison and Selection in Algae-to-Fuels Processes

    Energy Technology Data Exchange (ETDEWEB)

    Link, D.; Kail, B.; Curtis, W.; Tuerk,A.

    2011-01-01

    The controlled growth of microalgae as a feedstock for alternative transportation fuel continues to receive much attention. Microalgae have the characteristics of rapid growth rate, high oil (lipid) content, and ability to be grown in unconventional scenarios. Algae have also been touted as beneficial for CO{sub 2} reuse, as algae can be grown using CO{sub 2} emissions from fossil-based energy generation. Moreover, algae does not compete in the food chain, lessening the 'food versus fuel' debate. Most often, it is assumed that either rapid production rate or high oii content should be the primary factor in algae selection for algae-to-fuels production systems. However, many important characteristics of algae growth and lipid production must be considered for species selection, growth condition, and scale-up. Under light limited, high density, photoautotrophic conditions, the inherent growth rate of an organism does not affect biomass productivity, carbon fixation rate, and energy fixation rate. However, the oil productivity is organism dependent, due to physiological differences in how the organisms allocate captured photons for growth and oil production and due to the differing conditions under which organisms accumulate oils. Therefore, many different factors must be considered when assessing the overall energy efficiency of fuel production for a given algae species. Two species, Chlorella vulgaris and Botryococcus braunii, are popular choices when discussing algae-to-fuels systems. Chlorella is a very robust species, often outcompeting other species in mixed-culture systems, and produces a lipid that is composed primarily of free fatty acids and glycerides. Botryococcus is regarded as a slower growing species, and the lipid that it produces is characterized by high hydrocarbon content, primarily C28-C34 botryococcenes. The difference in growth rates is often considered to be an advantage oiChlorella. However, the total energy captured by each algal

  16. Exploring the potential of using algae in cosmetics.

    Science.gov (United States)

    Wang, Hui-Min David; Chen, Ching-Chun; Huynh, Pauline; Chang, Jo-Shu

    2015-05-01

    The applications of microalgae in cosmetic products have recently received more attention in the treatment of skin problems, such as aging, tanning and pigment disorders. There are also potential uses in the areas of anti-aging, skin-whitening, and pigmentation reduction products. While algae species have already been used in some cosmetic formulations, such as moisturizing and thickening agents, algae remain largely untapped as an asset in this industry due to an apparent lack of utility as a primary active ingredient. This review article focuses on integrating studies on algae pertinent to skin health and beauty, with the purpose of identifying serviceable algae functions in practical cosmetic uses.

  17. Acetone, butanol, and ethanol production from wastewater algae.

    Science.gov (United States)

    Ellis, Joshua T; Hengge, Neal N; Sims, Ronald C; Miller, Charles D

    2012-05-01

    Acetone, butanol, and ethanol (ABE) fermentation by Clostridium saccharoperbutylacetonicum N1-4 using wastewater algae biomass as a carbon source was demonstrated. Algae from the Logan City Wastewater Lagoon system grow naturally at high rates providing an abundant source of renewable algal biomass. Batch fermentations were performed with 10% algae as feedstock. Fermentation of acid/base pretreated algae produced 2.74 g/L of total ABE, as compared with 7.27 g/L from pretreated algae supplemented with 1% glucose. Additionally, 9.74 g/L of total ABE was produced when xylanase and cellulase enzymes were supplemented to the pretreated algae media. The 1% glucose supplement increased total ABE production approximately 160%, while supplementing with enzymes resulted in a 250% increase in total ABE production when compared to production from pretreated algae with no supplementation of extraneous sugar and enzymes. Additionally, supplementation of enzymes produced the highest total ABE production yield of 0.311 g/g and volumetric productivity of 0.102 g/Lh. The use of non-pretreated algae produced 0.73 g/L of total ABE. The ability to engineer novel methods to produce these high value products from an abundant and renewable feedstock such as algae could have significant implications in stimulating domestic energy economies.

  18. Algae Bioreactor Using Submerged Enclosures with Semi-Permeable Membranes

    Science.gov (United States)

    Trent, Jonathan D (Inventor); Gormly, Sherwin J (Inventor); Embaye, Tsegereda N (Inventor); Delzeit, Lance D (Inventor); Flynn, Michael T (Inventor); Liggett, Travis A (Inventor); Buckwalter, Patrick W (Inventor); Baertsch, Robert (Inventor)

    2013-01-01

    Methods for producing hydrocarbons, including oil, by processing algae and/or other micro-organisms in an aquatic environment. Flexible bags (e.g., plastic) with CO.sub.2/O.sub.2 exchange membranes, suspended at a controllable depth in a first liquid (e.g., seawater), receive a second liquid (e.g., liquid effluent from a "dead zone") containing seeds for algae growth. The algae are cultivated and harvested in the bags, after most of the second liquid is removed by forward osmosis through liquid exchange membranes. The algae are removed and processed, and the bags are cleaned and reused.

  19. Importance of algae oil as a source of biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, Ayhan [Sirnak University, Dean of Engineering Faculty, Sirnak (Turkey); Fatih Demirbas, M. [Sila Science, University Mah., Mekan Sok No. 24, Trabzon (Turkey)

    2011-01-15

    Algae are the fastest-growing plants in the world. Industrial reactors for algal culture are open ponds, photobioreactors and closed systems. Algae are very important as a biomass source. Algae will some day be competitive as a source for biofuel. Different species of algae may be better suited for different types of fuel. Algae can be grown almost anywhere, even on sewage or salt water, and does not require fertile land or food crops, and processing requires less energy than the algae provides. Algae can be a replacement for oil based fuels, one that is more effective and has no disadvantages. Algae are among the fastest-growing plants in the world, and about 50% of their weight is oil. This lipid oil can be used to make biodiesel for cars, trucks, and airplanes. Microalgae have much faster growth-rates than terrestrial crops. the per unit area yield of oil from algae is estimated to be from 20,000 to 80,000 l per acre, per year; this is 7-31 times greater than the next best crop, palm oil. The lipid and fatty acid contents of microalgae vary in accordance with culture conditions. Most current research on oil extraction is focused on microalgae to produce biodiesel from algal oil. Algal-oil processes into biodiesel as easily as oil derived from land-based crops. (author)

  20. Interactions between arsenic species and marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, J.G.

    1978-01-01

    The arsenic concentration and speciation of marine algae varies widely, from 0.4 to 23 ng.mg/sup -1/, with significant differences in both total arsenic content and arsenic speciation occurring between algal classes. The Phaeophyceae contain more arsenic than other algal classes, and a greater proportion of the arsenic is organic. The concentration of inorganic arsenic is fairly constant in macro-algae, and may indicate a maximum level, with the excess being reduced and methylated. Phytoplankton take up As(V) readily, and incorporate a small percentage of it into the cell. The majority of the As(V) is reduced, methylated, and released to the surrounding media. The arsenic speciation in phytoplankton and Valonia also changes when As(V) is added to cultures. Arsenate and phosphate compete for uptake by algal cells. Arsenate inhibits primary production at concentrations as low as 5 ..mu..g.1/sup -1/ when the phosphate concentration is low. The inhibition is competitive. A phosphate enrichment of > 0.3 ..mu..M alleviates this inhibition; however, the As(V) stress causes an increase in the cell's phosphorus requirement. Arsenite is also toxic to phytoplankton at similar concentrations. Methylated arsenic species did not affect cell productivity, even at concentrations of 25 ..mu..g.1/sup -1/. Thus, the methylation of As(V) by the cell produces a stable, non-reactive compound which is nontoxic. The uptake and subsequent reduction and methylation of As(V) is a significant factor in determining the arsenic biogeochemistry of productive systems, and also the effect that the arsenic may have on algal productivity. Therefore, the role of marine algae in determining the arsenic speciation of marine systems cannot be ignored. (ERB)

  1. Pheromones in marine algae: A technical approach

    Science.gov (United States)

    Gassmann, G.; Müller, D. G.; Fritz, P.

    1995-03-01

    It is now well known that many marine organisms use low-molecular volatile substances as signals, in order to coordinate activities between different individuals. The study of such pheromones requires the isolation and enrichment of the secretions from undisturbed living cells or organisms over extended periods of time. The Grob-Hersch extraction device, which we describe here, avoids adverse factors for the biological materials such as strong water currents, rising gas bubbles or chemical solvents. Furthermore, the formation of sea-water spray is greatly reduced. The application of this technique for the isolation of pheromones of marine algae and animals is described.

  2. Energy from algae using microbial fuel cells

    KAUST Repository

    Velasquez-Orta, Sharon B.

    2009-08-15

    Bioelectricity production froma phytoplankton, Chlorella vulgaris, and a macrophyte, Ulva lactuca was examined in single chamber microbial fuel cells (MFCs). MFCs were fed with the two algae (as powders), obtaining differences in energy recovery, degradation efficiency, and power densities. C. vulgaris produced more energy generation per substrate mass (2.5 kWh/kg), but U. lactuca was degraded more completely over a batch cycle (73±1% COD). Maximum power densities obtained using either single cycle or multiple cycle methods were 0.98 W/m2 (277 W/m3) using C. vulgaris, and 0.76 W/m2 (215 W/m3) using U. lactuca. Polarization curves obtained using a common method of linear sweep voltammetry (LSV) overestimated maximum power densities at a scan rate of 1 mV/s. At 0.1 mV/s, however, the LSV polarization data was in better agreement with single- and multiple-cycle polarization curves. The fingerprints of microbial communities developed in reactors had only 11% similarity to inocula and clustered according to the type of bioprocess used. These results demonstrate that algae can in principle, be used as a renewable source of electricity production in MFCs. © 2009 Wiley Periodicals, Inc.

  3. Algae-based oral recombinant vaccines.

    Science.gov (United States)

    Specht, Elizabeth A; Mayfield, Stephen P

    2014-01-01

    Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for "molecular pharming" in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae could be poised to become the next candidate in recombinant subunit vaccine production, as they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered - from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and systemic immune reactivity.

  4. Algae-based oral recombinant vaccines

    Directory of Open Access Journals (Sweden)

    Elizabeth A Specht

    2014-02-01

    Full Text Available Recombinant subunit vaccines are some of the safest and most effective vaccines available, but their high cost and the requirement of advanced medical infrastructure for administration make them impractical for many developing world diseases. Plant-based vaccines have shifted that paradigm by paving the way for recombinant vaccine production at agricultural scale using an edible host. However, enthusiasm for molecular pharming in food crops has waned in the last decade due to difficulty in developing transgenic crop plants and concerns of contaminating the food supply. Microalgae are poised to become the next candidate in recombinant subunit vaccine production, and they present several advantages over terrestrial crop plant-based platforms including scalable and contained growth, rapid transformation, easily obtained stable cell lines, and consistent transgene expression levels. Algae have been shown to accumulate and properly fold several vaccine antigens, and efforts are underway to create recombinant algal fusion proteins that can enhance antigenicity for effective orally-delivered vaccines. These approaches have the potential to revolutionize the way subunit vaccines are made and delivered – from costly parenteral administration of purified protein, to an inexpensive oral algae tablet with effective mucosal and system immune reactivity.

  5. 苯甲酸钠对草履虫的毒性作用研究%Research on the Toxicity of Sodium Benzoate against Paramecium

    Institute of Scientific and Technical Information of China (English)

    刘俊; 李霖; 张晓燕

    2011-01-01

    The acute and chronic toxicity of sodium benzoate (SB) against paramecium was studied in this article. The one-hour acute toxicity experiment showed that the higher SB concentration was, the greater was the toxic effect. LC50 was 14.14g·L^-1 while the maximum totally-lethal concentration and minimum lethal con-centration was 19g·L^-1 and 8g·L^-1, respectively. The chronic toxicity experiment indicated that there existed significant dose-response-effect as well as time-response effect between the population growth rate and SB concentration. When the SB concentration was less than the minimum lethal concentration, an increased population growth rate was observed with the higher SB concentration when treated with a certain range of SB con- centration within a certain time. This promotion effect of sodium benzoate on the reproduction of paramecium might be due to the effect of environmental estrogens.%本文研究了苯甲酸钠对草履虫的急性和慢性毒性作用。结果表明:1h急性毒性实验显示,浓度越大,死亡率越高。1h急性毒性作用LC50为14.14g·L^-1,绝对致死剂量为19g·L^-1,最小致死剂量为8g·L^-1。慢性毒性实验显示,种群增长率与苯甲酸钠浓度间具有显著的反应-剂量效应和反应-时间效应,在小于绝对致死剂量情况下,一定时间、一定浓度范围内呈现出浓度越大,种群增长率越高的现象。苯甲酸钠对草履虫生殖的促进作用有可能是环境雌激素的效应。

  6. Sustainability of algae derived biodiesel: a mass balance approach.

    Science.gov (United States)

    Pfromm, Peter H; Amanor-Boadu, Vincent; Nelson, Richard

    2011-01-01

    A rigorous chemical engineering mass balance/unit operations approach is applied here to bio-diesel from algae mass culture. An equivalent of 50,000,000 gallons per year (0.006002 m3/s) of petroleum-based Number 2 fuel oil (US, diesel for compression-ignition engines, about 0.1% of annual US consumption) from oleaginous algae is the target. Methyl algaeate and ethyl algaeate diesel can according to this analysis conceptually be produced largely in a technologically sustainable way albeit at a lower available diesel yield. About 11 square miles of algae ponds would be needed with optimistic assumptions of 50 g biomass yield per day and m2 pond area. CO2 to foster algae growth should be supplied from a sustainable source such as a biomass-based ethanol production. Reliance on fossil-based CO2 from power plants or fertilizer production renders algae diesel non-sustainable in the long term.

  7. Reduction of water and energy requirement of algae cultivation using an algae biofilm photobioreactor.

    Science.gov (United States)

    Ozkan, Altan; Kinney, Kerry; Katz, Lynn; Berberoglu, Halil

    2012-06-01

    This paper reports the construction and performance of an algae biofilm photobioreactor that offers a significant reduction of the energy and water requirements of cultivation. The green alga Botryococcus braunii was cultivated as a biofilm. The system achieved a direct biomass harvest concentration of 96.4 kg/m(3) with a total lipid content 26.8% by dry weight and a productivity of 0.71 g/m(2) day, representing a light to biomass energy conversion efficiency of 2.02%. Moreover, it reduced the volume of water required to cultivate a kilogram of algal biomass by 45% and reduced the dewatering energy requirement by 99.7% compared to open ponds. Finally, the net energy ratio of the cultivation was 6.00 including dewatering. The current issues of this novel photobioreactor are also identified to further improve the system productivity and scaleup.

  8. Phycobiliproteins: A Novel Green Tool from Marine Origin Blue-Green Algae and Red Algae.

    Science.gov (United States)

    Chandra, Rashmi; Parra, Roberto; Iqbal, Hafiz M N

    2017-01-01

    Marine species are comprising about a half of the whole global biodiversity; the sea offers an enormous resource for novel bioactive compounds. Several of the marine origin species show multifunctional bioactivities and characteristics that are useful for a discovery and/or reinvention of biologically active compounds. For millennia, marine species that includes cyanobacteria (blue-green algae) and red algae have been targeted to explore their enormous potential candidature status along with a wider spectrum of novel applications in bio- and non-bio sectors of the modern world. Among them, cyanobacteria are photosynthetic prokaryotes, phylogenetically a primitive group of Gramnegative prokaryotes, ranging from Arctic to Antarctic regions, capable of carrying out photosynthesis and nitrogen fixation. In the recent decade, a great deal of research attention has been paid on the pronouncement of bio-functional proteins along with novel peptides, vitamins, fine chemicals, renewable fuel and bioactive compounds, e.g., phycobiliproteins from marine species, cyanobacteria and red algae. Interestingly, they are extensively commercialized for natural colorants in food and cosmetics, antimicrobial, antioxidant, anti-inflammatory, neuroprotective, hepatoprotective agents and fluorescent neo-glycoproteins as probes for single particle fluorescence imaging fluorescent applications in clinical and immunological analysis. However, a comprehensive knowledge and technological base for augmenting their commercial utilities are lacking. Therefore, this paper will provide an overview of the phycobiliproteins-based research literature from marine cyanobacteria and red algae. This review is also focused towards analyzing global and commercial activities with application oriented-based research. Towards the end, the information is also given on the potential biotechnological and biomedical applications of phycobiliproteins.

  9. The globins of cyanobacteria and algae.

    Science.gov (United States)

    Johnson, Eric A; Lecomte, Juliette T J

    2013-01-01

    Approximately, 20 years ago, a haemoglobin gene was identified within the genome of the cyanobacterium Nostoc commune. Haemoglobins have now been confirmed in multiple species of photosynthetic microbes beyond N. commune, and the diversity of these proteins has recently come under increased scrutiny. This chapter summarizes the state of knowledge concerning the phylogeny, physiology and chemistry of globins in cyanobacteria and green algae. Sequence information is by far the best developed and the most rapidly expanding aspect of the field. Structural and ligand-binding properties have been described for just a few proteins. Physiological data are available for even fewer. Although activities such as nitric oxide dioxygenation and oxygen scavenging are strong candidates for cellular function, dedicated studies will be required to complete the story on this intriguing and ancient group of proteins.

  10. An assessment of haplotype variation in ribosomal and mitochondrial DNA fragments suggests incomplete lineage sorting in some species of the Paramecium aurelia complex (Ciliophora, Protozoa).

    Science.gov (United States)

    Tarcz, Sebastian; Przyboś, Ewa; Surmacz, Marta

    2013-04-01

    The Paramecium aurelia complex (Ciliophora, Protozoa) Sonneborn (1975) is composed of 15 sibling species, which are morphologically indistinguishable but sexually isolated. Therefore, the P. aurelia complex seems to be an ideal model for testing hypotheses about recent speciation events. Here we present two-locus (ITS1-5.8S-ITS2-5'LSU rDNA and COI mtDNA) analyses using over 120 strains collected from around the world and representing all currently known species of the complex. According to our findings, the studied species show different levels of haplotype variability. Some of them appear on the obtained trees as polyphyletic (e.g., P. dodecaurelia), while others as monophyletic (e.g., P. quadecaurelia), clusters. The revealed discrepancies, which are manifested by different mating behavior and haplotypes not characteristic of particular species, may be explained by incomplete lineage sorting. Furthermore, the phenomena of hybridization and introgression are considered as another explanation for our results. Despite the above discrepancies, "polyphyletic taxa" should be considered true biological species based on the results of genetic crosses. Using a combination of both strain crosses (the biological species concept) and molecular methods (the phylogenetic species concept) seems to be the appropriate way of delimiting species in closely related eukaryotic microorganisms such as the P. aurelia complex.

  11. Green fluorescent protein-tagged sarco(endo)plasmic reticulum Ca2+-ATPase overexpression in Paramecium cells: isoforms, subcellular localization, biogenesis of cortical calcium stores and functional aspects.

    Science.gov (United States)

    Hauser, K; Pavlovic, N; Klauke, N; Geissinger, D; Plattner, H

    2000-08-01

    We have followed the time-dependent transfection of Paramecium cells with a vector containing the gene of green fluorescent protein (GFP) attached to the C-terminus of the PtSERCA1 gene. The outlines of alveolar sacs (ASs) are labelled, as is the endoplasmic reticulum (ER) throughout the cell. When GFP fluorescence is compared with previous anti-PtSERCA1 antibody labelling, the much wider distribution of GFP (ER+ASs) indicates that only a small amount of SERCA molecules is normally retained in the ER. A second isoform, PtSERCA2, also occurs and its C-terminal GFP-tagging results in the same distribution pattern. However, when GFP is inserted in the major cytoplasmic loop, PtSERCA1 and two fusion proteins are mostly retained in the ER, probably because of the presence of the overt C-terminal KKXX ER-retention signal and/or masking of a signal for transfer into ASs. On the overall cell surface, new SERCA molecules seem to be permanently delivered from the ER to ASs by vesicle transport, whereas in the fission zone of dividing cells ASs may form anew. In cells overexpressing PtSERCA1 (with C-terminal GFP) in ASs, [Ca2+]i regulation during exocytosis is not significantly different from controls, probably because their Ca2+ pump has to mediate only slow reuptake.

  12. One-way calcium spill-over during signal transduction in Paramecium cells: from the cell cortex into cilia, but not in the reverse direction.

    Science.gov (United States)

    Husser, Marc R; Hardt, Martin; Blanchard, Marie-Pierre; Hentschel, Joachim; Klauke, Norbert; Plattner, Helmut

    2004-11-01

    We asked to what extent Ca(2+) signals in two different domains of Paramecium cells remain separated during different stimulations. Wild-type (7S) and pawn cells (strain d4-500r, without ciliary voltage-dependent Ca(2+)-channels) were stimulated for trichocyst exocytosis within 80 ms by quenched-flow preparation and analysed by energy-dispersive X-ray microanalysis (EDX), paralleled by fast confocal fluorochrome analysis. We also analysed depolarisation-dependent calcium signalling during ciliary beat rerversal, also by EDX, after 80-ms stimulation in the quenched-flow mode. EDX and fluorochrome analysis enable to register total and free intracellular calcium concentrations, [Ca] and [Ca(2+)], respectively. After exocytosis stimulation we find by both methods that the calcium signal sweeps into the basis of cilia, not only in 7S but also in pawn cells which then also perform ciliary reversal. After depolarisation we see an increase of [Ca] along cilia selectively in 7S, but not in pawn cells. Opposite to exocytosis stimulation, during depolarisation no calcium spill-over into the nearby cytosol and no exocytosis occurs. In sum, we conclude that cilia must contain a very potent Ca(2+) buffering system and that ciliary reversal induction, much more than exocytosis stimulation, involves strict microdomain regulation of Ca(2+) signals.

  13. pH值对草履虫种群增长的影响%Effects of pH on Population Growth of Paramecium Caudatum

    Institute of Scientific and Technical Information of China (English)

    黄林

    2005-01-01

    用群体累积培养法研究了pH值对草履虫(paramecium caudatum)种群增长的影响.在酸性较强(pH为3.0和4.0)的环境下草履虫均死亡.pH为4.0-10.0时草履虫均能正常生长.方差分析结果表明pH值对草履虫的密度和种群增长率均无显著影响(P>0.05).草履虫对酸的耐受范围在5.0-7.0之间;而在弱碱性环境下,pH在8.0时草履虫的密度和种群增长率较大,并随着pH的增大而减小.

  14. Timing of initiation of macronuclear DNA synthesis is set during the preceding cell cycle in Paramecium tetraurelia: analysis of the effects of abrupt changes in nutrient level

    Energy Technology Data Exchange (ETDEWEB)

    Ching, A.S.L.; Berger, J.D.

    1986-11-01

    In many eukaryotic organisms, initiation of DNA synthesis is associated with a major control point within the cell cycle and reflects the commitment of the cell to the DNA replication-division portion of the cell cycle. In paramecium, the timing of DNA synthesis initiation is established prior to fission during the preceding cell cycle. DNA synthesis normally starts at 0.25 in the cell cycle. When dividing cells are subjected to abrupt nutrient shift-up by transfer from a chemostat culture to medium with excess food, or shift-down from a well-fed culture to exhausted medium, DNA synthesis initiation in the post-shift cell cycle occurs at 0.25 of the parental cell cycle and not at either 0.25 in the post-shift cell cycle or at 0.25 in the equilibrium cell cycle produced under the post-shift conditions. The long delay prior to initiation of DNA synthesis following nutritional shift-up is not a consequence of continued slow growth because the rate of protein synthesis increases rapidly to the normal level after shift-up. Analysis of the relation between increase in cell mass and initiation of DNA synthesis following nutritional shifts indicates that increase in cell mass, per se, is neither a necessary nor a sufficient condition for initiation of DNA synthesis, in spite of the strong association between accumulation of cell mass and initiation of DNA synthesis in cells growing under steady-state conditions.

  15. 对草履虫培养和观察实验的改进%Improvement in culture and observation experiment on paramecium

    Institute of Scientific and Technical Information of China (English)

    马惠钦; 周洪显; 石玉珍

    2006-01-01

    尾草履虫Paramecium caudatum Ehrenberg,又称草履虫、大草履虫,属原生动物门,纤毛纲,是动物界中较原始、较低等、较典型的单细胞动物。其个体较大、结构典型、繁殖快、观察方便、容易采集和培养,不仅生物学教学中以它做代表动物,也用作一种研究模型,在遗传学、细胞生物学、生物化学及生理学等领域广泛应用,在揭示生命的一些基本规律中显示出极大的科学价值。尽管草履虫很容易采集到,但培养和观察草履虫的实验多安排在初冬季节,此时室外温度一般在10℃左右,天然水体中的草履虫密度远远不能满足实验的要求,必须提前进行人工培养。

  16. Shewanella alga bacteremia in two patients with lower leg ulcers

    DEFF Research Database (Denmark)

    Domínguez, H.; Vogel, Birte Fonnesbech; Gram, Lone;

    1996-01-01

    The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source of infec......The first Danish cases of Shewanella alga bacteremia in two patients with chronic lower leg ulcers are reported. Both patients were admitted to the hospital during the same month of a very warm summer and had been exposed to the same marine environment, thereby suggesting the same source......'Etoile, France), but further genetic and physiological analyses identified them as Shewanella alga....

  17. Macro-economics of algae products : Output WP2A7.02

    NARCIS (Netherlands)

    Voort, van der M.P.J.; Vulsteke, E.; Visser, de C.L.M.

    2015-01-01

    This report is part of the EnAlgae Workpackage 2, Action 7, directed at the economics of algae production. The goal of this report is to highlight potential markets for algae. Per type of algae market the market size, product alternatives, constraints and prices are highlighted. Based on these marke

  18. Effects of elevated CO2 on sensitivity of six species of algae and interspecific competition of three species of algae

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Effects of elevated CO2 (5000 μl/L) on sensitivity comparison of six species of algae and interspecific competition of three species of algae were investigated. The results showed that, the cell densities of six species of algae grown in elevated CO2significantly increased compared to those in ambient CO2 (360 μl/L), and with the time prolonged, the increasing extent increased.Therefore, elevated CO2 can promote the growth of six species of algae. However, there were differences in sensitivity between six species of algae. Based on the effects of elevated CO2 on biomass, the sensitive order (from high to low) was Platymanas sp.,Platymanas subcordiformis, Nitzschia closterium, Isochrysis galbana Parke 8701, Dunaliella salina, Chlorella sp., on the condition of solitary cultivation. Compared to ambient CO2, elevated CO2 promoted the growth of three species of algae, Platymanas subcordiformis, Nitzschia closterium and Isochrysis galbana Parke 8701 under the condition of mixed cultivation. The sensitivity of the three species to elevated CO2 in mixed cultivation changed a lot compared to the condition of solitary cultivation. When grown in elevated CO2 under the condition of mixed cultivation, the sensitive order from high to low were Nitzschia clostertium, Platymonas subcordiformis and Isochrysis galbana Parke 8701. However, under the condition of solitary cultivation, the sensitive order in elevated CO2 was Isochrysis galbana Parke 8701, Nitzschia clostertium, Platymonas subcordiformis, from sensitive to less sensitive. On the day 21, the dominant algae, the sub-dominant algae and inferior algae grown in elevated CO2 did not change. However, the population increasing dynamic and composition proportion of three algal species have significantly changed.

  19. 两种典型持久性有机污染物对草履虫急性毒性初探%Initial Study on Acute Toxicity of Two Typical Persistent Organic Pollutants (POPs) against Paramecium caudatum

    Institute of Scientific and Technical Information of China (English)

    周海龙; 李国锋; 黄仁良; 崔嵩; 刁晓平

    2011-01-01

    Dichlorodiphenyltrichloroethane (DDT) and Benzo[a]pyrene (BaP) are ubiquitous contaminants in the environment. Acute toxic effects of DDT and BaP on a model unicellular eukaryotic organism Paramecium caudatum were studied and a dose-dependent increase in toxicities was observed. The median lethal concentration (LC50) of DDT in 1h is 126.012 mg·L- 1 and that of BaP is 180.167 mg·L- 1. There exists a good linear relationship between probit and logarithm of concentrations of contaminants. Exposed to DDT and BaP at different concentrations, Paramecia caudatum exhibited some shapes. Comparably, DDT is more toxic to Paramecium caudatum than that of BaP. Sensitive to both DDT and BaP suggests that Paramecium caudatum can be used as a sensitive indicator for early risk assessment of longterm hazards of POPs. These results provide a novel approach for developing a strategy for the abatement of water pollution and maintenance of ecosystem viability. Finally, the toxicity mechanism of two typical POPs in Paramecium caudatum is discussed.%滴滴涕和苯并芘这两种典型持久性有机污染物在环境中已广泛分布,因此,本研究利用单细胞真核模式生物-草履虫来研究其急性毒性效应,结果发现其毒性效应存在显著的剂量效应关系.DDT和BaP的半数致死浓度分别为126.012 mg·L-1和180.167 mg·L-1,且这两种污染物的浓度和概率间存在很好的线性关系.不同浓度的DDT和BaP对草履虫进行毒性作用时,草履虫呈现出不同的形态;比较而言,DDT的毒性作用更大.由于草履虫对这两种毒性物质作用的敏感性,因此,草履虫可作为一种敏感指示生物来评估POPs的长期危害.本研究为水污染的减排和生境的保护提供了一种新途径.最后,就这两种典型POPs对草履虫的毒性机理进行了讨论.

  20. Sterol composition of the Adriatic Sea algae Ulva lactuca, Codium dichotomum, Cystoseira adriatica and Fucus virsoides

    Directory of Open Access Journals (Sweden)

    RADOMIR KAPETANOVIC

    2005-12-01

    Full Text Available The sterol composition of two green algae and two brown algae from the South Adriatic was determined. In the green alga Ulva lactuca, the principal sterols were cholesterol and isofucosterol. In the brown alga Cystoseira adriatica, the main sterols were cholesterol and stigmast-5-en-3ß-ol, while the characteristic sterol of the brown algae, fucosterol, was found only in low concentration. The sterol fractions of the green alga Codium dichotomum and the brown alga Fucus virsoides contained practically only one sterol each, comprising more than 90 % of the total sterols (clerosterol in the former and fucosterol in the latter.

  1. Exploration of the gasification of Spirulina algae in supercritical water.

    Science.gov (United States)

    Miller, Andrew; Hendry, Doug; Wilkinson, Nikolas; Venkitasamy, Chandrasekar; Jacoby, William

    2012-09-01

    This study presents non-catalytic gasification of Spirulina algae in supercritical water using a plug flow reactor and a mechanism for feeding solid carbon streams into high pressure (>25 MPa) environments. A 2(III)(3-1) factorial experimental design explored the effect of concentration, temperature, and residence time on gasification reactions. A positive displacement pump fed algae slurries into the reactor at a temperature range of 550-600°C, and residence times between 4 and 9s. The results indicate that algae gasify efficiently in supercritical water, highlighting the potential for a high throughput process. Additional experiments determined Arrhenius parameters of Spirulina algae. This study also presents a model of the gasification reaction using the estimated activation energy (108 kJ/mol) and other Arrhenius parameters at plug flow conditions. The maximum rate of gasification under the conditions studied of 53 g/Ls is much higher than previously reported.

  2. Application of synthetic biology in cyanobacteria and algae

    Directory of Open Access Journals (Sweden)

    Bo eWang

    2012-09-01

    Full Text Available Cyanobacteria and algae are becoming increasingly attractive cell factories for producing renewable biofuels and chemicals due to their ability to capture solar energy and CO2 and their relatively simple genetic background for genetic manipulation. Increasing research efforts from the synthetic biology approach have been made in recent years to modify cyanobacteria and algae for various biotechnological applications. In the article, we critically review recent progresses in developing genetic tools for characterizing or manipulating cyanobacteria and algae, the applications of genetically modified strains for synthesizing renewable products such as biofuels and chemicals. In addition, the emergent challenges in the development and application of synthetic biology for cyanobacteria and algae are also discussed.

  3. Lab on a chip technologies for algae detection: a review.

    Science.gov (United States)

    Schaap, Allison; Rohrlack, Thomas; Bellouard, Yves

    2012-08-01

    Over the last few decades, lab on a chip technologies have emerged as powerful tools for high-accuracy diagnosis with minute quantities of liquid and as tools for exploring cell properties in general. In this paper, we present a review of the current status of this technology in the context of algae detection and monitoring. We start with an overview of the detection methods currently used for algae monitoring, followed by a review of lab on a chip devices for algae detection and classification, and then discuss a case study based on our own research activities. We conclude with a discussion on future challenges and motivations for algae-oriented lab on a chip technologies.

  4. Bicarbonate produced from carbon capture for algae culture.

    Science.gov (United States)

    Chi, Zhanyou; O'Fallon, James V; Chen, Shulin

    2011-11-01

    Using captured CO(2) to grow microalgae is limited by the high cost of CO(2) capture and transportation, as well as significant CO(2) loss during algae culture. Moreover, algae grow poorly at night, but CO(2) cannot be temporarily stored until sunrise. To address these challenges, we discuss a process where CO(2) is captured as bicarbonate and used as feedstock for algae culture, and the carbonate regenerated by the culture process is used as an absorbent to capture more CO(2). This process would significantly reduce carbon capture costs because it does not require additional energy for carbonate regeneration. Furthermore, not only would transport of the aqueous bicarbonate solution cost less than for that of compressed CO(2), but using bicarbonate would also provide a superior alternative for CO(2) delivery to an algae culture system.

  5. Kalaärimeeste kohus algas venitamisega / Hindrek Riikoja

    Index Scriptorium Estoniae

    Riikoja, Hindrek

    2007-01-01

    Harju maakohtus algas kohtuprotsess veterinaar- ja toiduameti endise asejuhi Vladimir Razumovski väidetava altkäemaksuvõtmise üle, kus on süüdistavaid eraisikuid ja ettevõtjaid. Lisa: Kes on kohtu all?

  6. Evaluation of filamentous green algae as feedstocks for biofuel production.

    Science.gov (United States)

    Zhang, Wei; Zhao, Yonggang; Cui, Binjie; Wang, Hui; Liu, Tianzhong

    2016-11-01

    Compared with unicellular microalgae, filamentous algae have high resistance to grazer-predation and low-cost recovery in large-scale production. Green algae, as the most diverse group of algae, included numerous filamentous genera and species. In this study, records of filamentous genera and species in green algae were firstly censused and classified. Then, seven filamentous strains subordinated in different genera were cultivated in bubbled-column to investigate their growth rate and energy molecular (lipid and starch) capacity. Four strains including Stigeoclonium sp., Oedogonium nodulosum, Hormidium sp. and Zygnema extenue were screened out due to their robust growth. And they all could accumulate triacylglycerols and starch in their biomass, but with different capacity. After nitrogen starvation, Hormidium sp. and Oedogonium nodulosum respectively exhibited high capacity of lipid (45.38% in dry weight) and starch (46.19% in dry weight) accumulation, which could be of high potential as feedstocks for biodiesel and bioethanol production.

  7. Colourful Cultures: Classroom Experiments with the Unicellular Alga Haematococcus pluvialis.

    Science.gov (United States)

    Delpech, Roger

    2001-01-01

    Describes an investigation into the photosynthetic potential of the different developmental stages of the green unicellular alga Haematococcus pluvialis. Reviews the biotechnological applications of astaxanthin, the red pigment which can be extracted from Haematococcus pluvialis. (Author/MM)

  8. Scenario analysis of large scale algae production in tubular photobioreactors

    NARCIS (Netherlands)

    Slegers, P.M.; Beveren, van P.J.M.; Wijffels, R.H.; Straten, van G.; Boxtel, van A.J.B.

    2013-01-01

    Microalgae productivity in tubular photobioreactors depends on algae species, location, tube diameter, biomass concentration, distance between tubes and for vertically stacked systems, the number of horizontal tubes per stack. A simulation model for horizontal and vertically stacked horizontal tubul

  9. Chemical examination of the Red alga Acanthophora spicifera

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Kamat, S.Y.

    Analyses of petroleum ether and chloroform extracts of the marine alga Acanthophora spicifera exhibiting antifertility activity led to the isolation of sterols and fatty acids as well as the rare dipeptides aurantiamides. All the compounds were...

  10. Calculating the global contribution of coralline algae to carbon burial

    Directory of Open Access Journals (Sweden)

    L. H. van der Heijden

    2015-05-01

    Full Text Available The ongoing increase in anthropogenic carbon dioxide (CO2 emissions is changing the global marine environment and is causing warming and acidification of the oceans. Reduction of CO2 to a sustainable level is required to avoid further marine change. Many studies investigate the potential of marine carbon sinks (e.g. seagrass to mitigate anthropogenic emissions, however, information on storage by coralline algae and the beds they create is scant. Calcifying photosynthetic organisms, including coralline algae, can act as a CO2 sink via photosynthesis and CaCO3 dissolution and act as a CO2 source during respiration and CaCO3 production on short-term time scales. Long-term carbon storage potential might come from the accumulation of coralline algae deposits over geological time scales. Here, the carbon storage potential of coralline algae is assessed using meta-analysis of their global organic and inorganic carbon production and the processes involved in this metabolism. Organic and inorganic production were estimated at 330 g C m−2 yr−1 and 880 g CaCO3 m−2 yr−1 respectively giving global organic/inorganic C production of 0.7/1.8 × 109 t C yr−1. Calcium carbonate production by free-living/crustose coralline algae (CCA corresponded to a sediment accretion of 70/450 mm kyr−1. Using this potential carbon storage by coralline algae, the global production of free-living algae/CCA was 0.4/1.2 × 109 t C yr−1 suggesting a total potential carbon sink of 1.6 × 109 t C yr−1. Coralline algae therefore have production rates similar to mangroves, saltmarshes and seagrasses representing an as yet unquantified but significant carbon store, however, further empirical investigations are needed to determine the dynamics and stability of that store.

  11. Biomethanation of Red Algae from the Eutrophied Baltic Sea

    OpenAIRE

    Biswas, Rajib

    2009-01-01

    In the semi-enclosed Baltic Sea, excessive filamentous macro-algal biomass growth as a result of eutrophication is an increasing environmental problem. Drifting huge masses of red algae of the genera Polysiphonia, Rhodomela, and Ceramium accumulate on the open shore, up to five tones of algae per meter beach. During the aerobic decomposition of these algal bodies, large quantities of red colored effluents leak into the water what are toxic for the marine environment. In this study, feasibilit...

  12. Lipid constituents of the red alga Acantophora spicifera

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; De; Govenkar, M.B.

    solitary reference on the pollution of marine alga Stoechospermum marginatum \\[13\\] by the esters. Ortho-phthalic esters are being reported here for the first time as pollutants of marine red alga Acantophora spic(\\['era. The presence of para... compounds in the order designated as 1 2, 3 and 4. All these compounds were purified by repeated chromatography over silica gel. Acknowledgements--The authors wish to thank Dr. E. DeSa, Director, National Institute of Ocean- ography, for his keen...

  13. Biodiesel Fuel Production from Algae as Renewable Energy

    OpenAIRE

    Sharif Hossain, A.B.M.; Aishah Salleh; Amru Nasrulhaq Boyce; Partha chowdhury; Mohd Naqiuddin

    2008-01-01

    Biodiesel is biodegradable, less CO2 and NOx emissions. Continuous use of petroleum sourced fuels is now widely recognized as unsustainable because of depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Algae have emerged as one of the most promising sources for biodiesel production. It can be inferred that algae grown in CO...

  14. Feeding preferences of mesograzers on aquacultured Gracilaria and sympatric algae

    Science.gov (United States)

    Cruz-Rivera, Edwin; Friedlander, Michael

    2011-01-01

    While large grazers can often be excluded effectively from algal aquaculture operations, smaller herbivores such as small crustaceans and gastropods may be more difficult to control. The susceptibility of three Gracilaria species to herbivores was evaluated in multiple-choice experiments with the amphipod Ampithoe ramondi and the crab Acanthonyx lunulatus. Both mesograzers are common along the Mediterranean coast of Israel. When given a choice, the amphipod preferred to consume Gracilaria lemaneiformis significantly more than either G. conferta or G. cornea. The crab, however, consumed equivalent amounts of G. lemaneiformis and G. conferta, but did not consume G. cornea. Organic content of these algae, an important feeding cue for some mesograzers, could not account for these differences. We further assessed the susceptibility of a candidate species for aquaculture, G. lemaneiformis, against local algae, including common epiphytes. When given a choice of four algae, amphipods preferred the green alga Ulva lactuca over Jania rubens. However, consumption of U. lactuca was equivalent to those of G. lemaneiformis and Padina pavonica. In contrast, the crab showed a marked and significant preference for G. lemaneiformis above any of the other three algae offered. Our results suggest that G. cornea is more resistant to herbivory from common mesograzers and that, contrary to expectations, mixed cultures or epiphyte growth on G. lemaneiformis cannot reduce damage to this commercially appealing alga if small herbivores are capable of recruiting into culture ponds. Mixed cultures may be beneficial when culturing other Gracilaria species. PMID:22711945

  15. Development of Green Fuels From Algae - The University of Tulsa

    Energy Technology Data Exchange (ETDEWEB)

    Crunkleton, Daniel; Price, Geoffrey; Johannes, Tyler; Cremaschi, Selen

    2012-12-03

    The general public has become increasingly aware of the pitfalls encountered with the continued reliance on fossil fuels in the industrialized world. In response, the scientific community is in the process of developing non-fossil fuel technologies that can supply adequate energy while also being environmentally friendly. In this project, we concentrate on green fuels which we define as those capable of being produced from renewable and sustainable resources in a way that is compatible with the current transportation fuel infrastructure. One route to green fuels that has received relatively little attention begins with algae as a feedstock. Algae are a diverse group of aquatic, photosynthetic organisms, generally categorized as either macroalgae (i.e. seaweed) or microalgae. Microalgae constitute a spectacularly diverse group of prokaryotic and eukaryotic unicellular organisms and account for approximately 50% of global organic carbon fixation. The PI's have subdivided the proposed research program into three main research areas, all of which are essential to the development of commercially viable algae fuels compatible with current energy infrastructure. In the fuel development focus, catalytic cracking reactions of algae oils is optimized. In the species development project, genetic engineering is used to create microalgae strains that are capable of high-level hydrocarbon production. For the modeling effort, the construction of multi-scaled models of algae production was prioritized, including integrating small-scale hydrodynamic models of algae production and reactor design and large-scale design optimization models.

  16. Study on Algae Removal by Immobilized Biosystem on Sponge

    Institute of Scientific and Technical Information of China (English)

    PEI Haiyan; HU Wenrong

    2006-01-01

    In this study, sponges were used to immobilize domesticated sludge microbes in a limited space, forming an immobilized biosystem capable of algae and microcystins removal. The removal effects on algae, microcystins and UV260 of this biosystem and the mechanism of algae removal were studied. The results showed that active sludge from sewage treatment plants was able to remove algae from a eutrophic lake's water after 7 d of domestication. The removal efficiency for algae,organic matter and microcystins increased when the domesticated sludge was immobilized on sponges. When the hydraulic retention time (HRT) was 5h, the removal rates of algae, microcystins and UV260 were 90%, 94.17% and 84%, respectively.The immobilized biosystem consisted mostly of bacteria, the Ciliata and Sarcodina protozoans and the Rotifer metazoans.Algal decomposition by zoogloea bacteria and preying by microcreatures were the two main modes of algal removal, which occurred in two steps: first, absorption by the zoogloea; second, decomposition by the zoogloea bacteria and the predacity of the microcreatures.

  17. Detection of Cyanotoxins in Algae Dietary Supplements

    Directory of Open Access Journals (Sweden)

    Audrey Roy-Lachapelle

    2017-02-01

    Full Text Available Algae dietary supplements are marketed worldwide as natural health products. Although their proprieties have been claimed as beneficial to improve overall health, there have been several previous reports of contamination by cyanotoxins. These products generally contain non-toxic cyanobacteria, but the methods of cultivation in natural waters without appropriate quality controls allow contamination by toxin producer species present in the natural environment. In this study, we investigated the presence of total microcystins, seven individual microcystins (RR, YR, LR, LA, LY, LW, LF, anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine in 18 different commercially available products containing Spirulina or Aphanizomenon flos-aquae. Total microcystins analysis was accomplished using a Lemieux oxidation and a chemical derivatization using dansyl chloride was needed for the simultaneous analysis of cylindrospermopsin, saxitoxin, and β-methylamino-l-alanine. Moreover, the use of laser diode thermal desorption (LDTD and ultra-high performance liquid chromatography (UHPLC both coupled to high resolution mass spectrometry (HRMS enabled high performance detection and quantitation. Out of the 18 products analyzed, 8 contained some cyanotoxins at levels exceeding the tolerable daily intake values. The presence of cyanotoxins in these algal dietary supplements reinforces the need for a better quality control as well as consumer’s awareness on the potential risks associated with the consumption of these supplements.

  18. Coccolithophorid algae culture in closed photobioreactors.

    Science.gov (United States)

    Moheimani, Navid R; Isdepsky, Andreas; Lisec, Jan; Raes, Eric; Borowitzka, Michael A

    2011-09-01

    The feasibility of growth, calcium carbonate and lipid production of the coccolithophorid algae (Prymnesiophyceae), Pleurochrysis carterae, Emiliania huxleyi, and Gephyrocapsa oceanica, was investigated in plate, carboy, airlift, and tubular photobioreactors. The plate photobioreactor was the most promising closed cultivation system. All species could be grown in the carboy photobioreactor. However, P. carterae was the only species which grew in an airlift photobioreactor. Despite several attempts to grow these coccolithophorid species in the tubular photobioreactor (Biocoil), including modification of the airlift and sparger design, no net growth could be achieved. The shear produced by turbulence and bubble effects are the most likely reasons for this failure to grow in the Biocoil. The highest total dry weight, lipid and calcium carbonate productivities achieved by P. carterae in the plate photobioreactors were 0.54, 0.12, and 0.06 g L(-1) day(-1) respectively. Irrespective of the type of photobioreactor, the productivities were P. carterae > E. huxleyi > G. oceanica. Pleurochrysis carterae lipid (20-25% of dry weight) and calcium carbonate (11-12% of dry weight) contents were also the highest of all species tested.

  19. Caffeine-induced Ca2+ transients and exocytosis in Paramecium cells. A correlated Ca2+ imaging and quenched-flow/freeze-fracture analysis.

    Science.gov (United States)

    Klauke, N; Plattner, H

    1998-01-01

    Caffeine causes a [Ca2+]i increase in the cortex of Paramecium cells, followed by spillover with considerable attenuation, into central cell regions. From [Ca2+]resti approximately 50 to 80 nm, [Ca2+]acti rises within /=2 sec. Chelation of Ca2+o considerably attenuated [Ca2+]i increase. Therefore, caffeine may primarily mobilize cortical Ca2+ pools, superimposed by Ca2+ influx and spillover (particularly in tl cells with empty trichocyst docking sites). In nd cells, caffeine caused trichocyst contents to decondense internally (Ca2+-dependent stretching, normally occurring only after membrane fusion). With 7S cells this usually occurred only to a small extent, but with increasing frequency as [Ca2+]i signals were reduced by [Ca2+]o chelation. In this case, quenched-flow and ultrathin section or freeze-fracture analysis revealed dispersal of membrane components (without fusion) subsequent to internal contents decondensation, opposite to normal membrane fusion when a full [Ca2+]i signal was generated by caffeine stimulation (with Ca2+i and Ca2+o available). We conclude the following. (i) Caffeine can mobilize Ca2+ from cortical stores independent of the presence of Ca2+o. (ii) To yield adequate signals for normal exocytosis, Ca2+ release and Ca2+ influx both have to occur during caffeine stimulation. (iii) Insufficient [Ca2+]i increase entails caffeine-mediated access of Ca2+ to the secretory contents, thus causing their decondensation before membrane fusion can occur. (iv) Trichocyst decondensation in turn gives a signal for an unusual dissociation of docking/fusion components at the cell membrane. These observations imply different threshold [Ca2+]i-values for membrane fusion and contents discharge.

  20. 草履虫活体观察--体积定量法的进一步完善%A Method for obervation of Living Paramecium

    Institute of Scientific and Technical Information of China (English)

    林盈; 高欣; 杨仙玉

    2009-01-01

    @@ 尾草履虫Paramecium caudatun,属于原生动物纤毛纲,一直是动物学实验中不可缺少的实验材料.由于虫体游动快速,给活体观察实验带来了困难.近年来有一些关于草履虫观察方法的报导(黄丽清,2000;龚军辉,2003;吴美仙,2003;马惠钦等,2006;杨丽红,魏开,2007),但是这些方法仍具有一定的局限性.本研究室在前人工作的基础上,总结并报告了活体观察草履虫的一套方法,包括体积定量法、矿物油封闭法和脱纤毛法(杨仙玉等,2008).体积定量法中,使用了22×22 mm2规格的盖玻片,观察效果良好.但是利用体积定量法对草履虫进行观察时,使用不同规格的盖玻片所需草履虫培养液的体积不同.本文针对4种规格的盖玻片,对所需最适草履虫培养液的体积进行了研究,扩充了体积定量法,为观察活体草履虫带来了更大的方便.

  1. Toxic effects of Cd++ on the population of Paramecium caudatum%Cd++对草履虫种群的毒性作用

    Institute of Scientific and Technical Information of China (English)

    胡好远; 郝家胜; 靳璐

    2006-01-01

    通过研究20℃培养条件下Cd++对草履虫(Paramecium caudatum)种群毒性影响,结果表明:Cd++对草履虫的24hLC50为0.3294mg/L,Cd++浓度对草履虫的种群增长率有极显著影响,多重比较结果显示高浓度组(0.25和0.30mg/L)下草履虫的种群增长率显著小于低浓度下(0.05、0.15和0.20mg/L)的值.回归分析结果表明草履虫种群增长率(Y,/d)与Cd++浓度(X,mg/L)之间呈曲线相关.在一定浓度范围内,草履虫种群增长率随Cd++浓度的升高而呈增大,但高的Cd++浓度显著地降低了草履虫的种群增长率;当Cd++浓度为0.1179mg/L时,草履虫种群有最大增长率1.5442/d.各浓度组与对照组之间的t-检验结果表明在较低的Cd++浓度范围内(0.05、0.10和0.15mg/L)草履虫的种群增长率显著大于对照组的值,而Cd++浓度为0.30mg/L时的草履虫种群增长率显著小于对照组的值.

  2. SOIL ALGAE OF BLADE OF COIL IN DONETSK REGION

    Directory of Open Access Journals (Sweden)

    Maltseva I.A.

    2011-12-01

    Full Text Available On territory of Donbass for more than 200 years the underground coal mining has produced, accompanied by the formation of the mine dumps. Finding ways to reduce their negative impact on the environment should be based on their comprehensive study. The soil algae are active participants in the syngenetic processes in industrial dumps of different origin. The purpose of this paper is to identify the species composition and dominant algae groups in dump mine SH/U5 “Western” in the western part of Donetsk.The test blade is covered with vegetation to the middle from all sides, and on the north side of 20-25 m to the top. The vegetation cover of the lower and middle tiers of all the exposures range in 70-80%. Projective vegetation cover of upper tiers of the northern, north-eastern and north-western exposures are in the range of 20-40%, other – 5-10%. We revealed some 38 algae species as a result of our research in southern, northern, western, and eastern slopes of the blade “Western”. The highest species diversity has Chlorophyta - 14 species (36.8% of the total number of species, then Cyanophyta - 9 (23,7%, Bacillariophyta - 7 (18,4%, Xantophyta - 5 (13.2%, and Eustigmatophyta - 3 (7.9%. The dominants are represented by Hantzschia amphyoxys (Ehrenberg Grunow in Cleve et Grunow, Bracteacoccus aerius, Klebsormidium flaccidum (Kützing Silva et al., Phormidium autumnale, Pinnularia borealis Ehrenberg, Planothidium lanceolatum (Brebisson in Kützing Bukhtiyarova, Xanthonema exile (Klebs Silva.It should be noted that the species composition of algae groups in different slopes of the blade was significantly different. Jacquard coefficient was calculated for algae communities varied in the range of 15,4-39,1%. The smallest number of algae species was observed on the southern slope of the blade (14 species, maximum was registered in the areas of north and west slopes. Differences in the species composition of algae were also observed in three

  3. Characterization of Meiotic Nuclear Degeneration in Paramecium tetraurelia%第四双小核草履虫减数分裂产物的退化特征分析

    Institute of Scientific and Technical Information of China (English)

    高欣; 徐川梅; 杨仙玉

    2011-01-01

    During the conjugation of Paramecium tetraurelia, one meiotic nucleus which enters the paroral region survives and undergoes mitotic division to form gametic pronuclei, while the remaining seven degenerate. To clarify if these meiotic outcomes degenerate in an apoptotic way, two kinds of vital fluorescence dyes, acridine orange and Hoechst 33342 were used. The observation showed that the degenerating nuclei outside the paroral region stained yellow-orange or greenish which indicates a programmed nuclear degeneration.%通过吖啶橙和Hoechst 33342两种活体荧光染料双染的方法对第四双小核草履虫(Paramecium tetraurelia)接合生殖过程中小核减数分裂产物进行观察,结果发现位于口旁锥外的小核分裂产物呈蓝绿色或黄绿色,表明它们以凋亡的方式发生退化.

  4. Utilisation des protozoaires ciliés (Paramecium africanum, Colpidium uncinatum, Neobursaridium gigas pour l'épuration bactériologique des eaux polluées en microcosme

    Directory of Open Access Journals (Sweden)

    Nguedji, JBT.

    2003-01-01

    Full Text Available An Microcosm Use of Ciliate Protozoa (Paramecium africanum, Colpidium uncinatum, Neobursaridium gigas for Bacterial Purification of Polluted Water. Tests on the grazing of ciliated protozoa Paramecium africanum, Colpidium uncinatum and Neobursaridium gigas on the bacteria Escherichia coli and Staphylococcus sp. were carried out in an microcosm aquatic environment. These tests aimed at assessment of the role of these predators protozoa in the bacterial purification of polluted water. The evolution of the feeding kinetics of these protozoa shows a phase of adaptation of the predator to the prey, with a slow feeding rate and a phase of accelerate of feeding. The two phases are separated by a short period of recognition. The polynomial functions of the kinetics of predation show that C. uncinatum and P. africanum graze faster on E. coli than on Staphylococcus sp., meanwhile N. gigas feeds slowly on E. coli than on Staphylococcus sp. The time of contact between the ciliated protozoa and the bacteria, the predatory protozoa specie and the specie of the bacteria, should be considered simultaneously when evaluating the variation of bacterial concentrations in aquatic environment being purified.

  5. KIN241: a gene involved in cell morphogenesis in Paramecium tetraurelia reveals a novel protein family of cyclophilin-RNA interacting proteins (CRIPs) conserved from fission yeast to man.

    Science.gov (United States)

    Krzywicka, A; Beisson, J; Keller, A M; Cohen, J; Jerka-Dziadosz, M; Klotz, C

    2001-10-01

    In this study, we report cloning, by functional complementation of the KIN241 gene involved in Paramecium cell morphogenesis, cortical organization and nuclear reorganization. This gene is predicted to encode a protein of a novel type, comprising a cyclophilin-type, peptidyl-prolyl isomerase domain, an RNA recognition motif, followed by a region rich in glutamate and lysine (EK domain) and a C-terminal string of serines. As homologues of this protein are present in the genomes of Schizosaccharomyces pombe, Caenorhabditis elegans, Drosophila melanogaster, Arabidopsis thaliana and Homo sapiens, the Kin241p predicted sequence defines a new family of proteins that we propose to call 'CRIP', for cyclophilin-RNA interacting protein. We demonstrate that, in Paramecium, Kin241p is localized in the nucleus and that deletion of some nuclear localization signals (NLSs) decreases transport of the protein into the nucleus. No Kin241-1 protein is present in mutant cells, suggesting that the C-terminal serine-rich region is responsible for protein stability.

  6. Two-Step Evolution of Endosymbiosis between Hydra and Algae

    KAUST Repository

    Ishikawa, Masakazu

    2016-07-09

    In the Hydra vulgaris group, only 2 of the 25 strains in the collection of the National Institute of Genetics in Japan currently show endosymbiosis with green algae. However, whether the other non-symbiotic strains also have the potential to harbor algae remains unknown. The endosymbiotic potential of non-symbiotic strains that can harbor algae may have been acquired before or during divergence of the strains. With the aim of understanding the evolutionary process of endosymbiosis in the H. vulgaris group, we examined the endosymbiotic potential of non-symbiotic strains of the H. vulgaris group by artificially introducing endosymbiotic algae. We found that 12 of the 23 non-symbiotic strains were able to harbor the algae until reaching the grand-offspring through the asexual reproduction by budding. Moreover, a phylogenetic analysis of mitochondrial genome sequences showed that all the strains with endosymbiotic potential grouped into a single cluster (cluster γ). This cluster contained two strains (J7 and J10) that currently harbor algae; however, these strains were not the closest relatives. These results suggest that evolution of endosymbiosis occurred in two steps; first, endosymbiotic potential was gained once in the ancestor of the cluster γ lineage; second, strains J7 and J10 obtained algae independently after the divergence of the strains. By demonstrating the evolution of the endosymbiotic potential in non-symbiotic H. vulgaris group strains, we have clearly distinguished two evolutionary steps. The step-by-step evolutionary process provides significant insight into the evolution of endosymbiosis in cnidarians.

  7. Plasticity predicts evolution in a marine alga.

    Science.gov (United States)

    Schaum, C Elisa; Collins, Sinéad

    2014-10-22

    Under global change, populations have four possible responses: 'migrate, acclimate, adapt or die' (Gienapp et al. 2008 Climate change and evolution: disentangling environmental and genetic response. Mol. Ecol. 17, 167-178. (doi:10.1111/j.1365-294X.2007.03413.x)). The challenge is to predict how much migration, acclimatization or adaptation populations are capable of. We have previously shown that populations from more variable environments are more plastic (Schaum et al. 2013 Variation in plastic responses of a globally distributed picoplankton species to ocean acidification. Nature 3, 298-230. (doi:10.1038/nclimate1774)), and here we use experimental evolution with a marine microbe to learn that plastic responses predict the extent of adaptation in the face of elevated partial pressure of CO2 (pCO2). Specifically, plastic populations evolve more, and plastic responses in traits other than growth can predict changes in growth in a marine microbe. The relationship between plasticity and evolution is strongest when populations evolve in fluctuating environments, which favour the evolution and maintenance of plasticity. Strikingly, plasticity predicts the extent, but not direction of phenotypic evolution. The plastic response to elevated pCO2 in green algae is to increase cell division rates, but the evolutionary response here is to decrease cell division rates over 400 generations until cells are dividing at the same rate their ancestors did in ambient CO2. Slow-growing cells have higher mitochondrial potential and withstand further environmental change better than faster growing cells. Based on this, we hypothesize that slow growth is adaptive under CO2 enrichment when associated with the production of higher quality daughter cells.

  8. Method and apparatus using an active ionic liquid for algae biofuel harvest and extraction

    Science.gov (United States)

    Salvo, Roberto Di; Reich, Alton; Dykes, Jr., H. Waite H.; Teixeira, Rodrigo

    2012-11-06

    The invention relates to use of an active ionic liquid to dissolve algae cell walls. The ionic liquid is used to, in an energy efficient manner, dissolve and/or lyse an algae cell walls, which releases algae constituents used in the creation of energy, fuel, and/or cosmetic components. The ionic liquids include ionic salts having multiple charge centers, low, very low, and ultra low melting point ionic liquids, and combinations of ionic liquids. An algae treatment system is described, which processes wet algae in a lysing reactor, separates out algae constituent products, and optionally recovers the ionic liquid in an energy efficient manner.

  9. Application of algae-biosensor for environmental monitoring.

    Science.gov (United States)

    Umar, Lazuardi; Alexander, Frank A; Wiest, Joachim

    2015-01-01

    Environmental problems including water and air pollution, over fertilization, insufficient wastewater treatment and even ecological disaster are receiving greater attention in the technical and scientific area. In this paper, a method for water quality monitoring using living green algae (Chlorella Kessleri) with the help of the intelligent mobile lab (IMOLA) is presented. This measurement used two IMOLA systems for measurement and reference simultaneously to verify changes due to pollution inside the measurement system. The IMOLA includes light emitting diodes to stimulate photosynthesis of the living algae immobilized on a biochip containing a dissolved oxygen microsensor. A fluid system is used to transport algae culture medium in a stop and go mode; 600s ON, 300s OFF, while the oxygen concentration of the water probe is measured. When the pump stops, the increase in dissolved oxygen concentration due to photosynthesis is detected. In case of a pollutant being transported toward the algae, this can be detected by monitoring the photosynthetic activity. Monitoring pollution is shown by adding emulsion of 0,5mL of Indonesian crude palm oil and 10mL algae medium to the water probe in the biosensor.

  10. THE FAMILY CALCIFOLIACEAE EMEND.,MISSISSIPPIAN-EARLY PENNSYLVANIAN ALGAE

    Directory of Open Access Journals (Sweden)

    DANIEL VACHARD

    2006-03-01

    Full Text Available The family Fasciellaceae was created as a group of red algae. It was emended as a tribe Fascielleae of incertae sedis algae, and related to the tribe Calcifolieae Shuysky emend. Vachard & Cózar. The tribes Fascielleae and Calcifolieae both constitute the family Calcifoliaceae emend. This family is actually a homogeneous group, and could be more or less closely related with some questionable Moravamminales and Aoujgaliales: Claracrustaceae, Labyrinthoconaceae and Donezellaceae. All these microfossils were successively considered as green algae, red algae, "phylloid" algae, or fibres of calcispongia. The genera included in Fascielleae are: Fasciella, Praedonezella, and ?Kulikaella. The genera Calcifolium, Falsocalcifolium and Frustulata are included in the Calcifolieae. The phylogeny of the Calcifoliaceae is reconstructed. Thus, the family appears to be ancestrally linked, in the early Mississippian and even earlier in the Devonian, to Kulikaella, Stacheoidella, Pseudostacheoides, Pokorninella and Precorninella. The Calcifoliaceae are important for the zonation of the Late Mississippian-earliest Pennsylvanian (early Bashkirian interval (Asbian to Siuransky in the carbonate platform facies from western Palaeotethys and Ural Oceans.

  11. Method to transform algae, materials therefor, and products produced thereby

    Science.gov (United States)

    Dunahay, Terri Goodman; Roessler, Paul G.; Jarvis, Eric E.

    1997-01-01

    Disclosed is a method to transform chlorophyll C-containing algae which includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae.

  12. Boron uptake, localization, and speciation in marine brown algae.

    Science.gov (United States)

    Miller, Eric P; Wu, Youxian; Carrano, Carl J

    2016-02-01

    In contrast to the generally boron-poor terrestrial environment, the concentration of boron in the marine environment is relatively high (0.4 mM) and while there has been extensive interest in its use as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the relatively depth independent, and the generally non-nutrient-like concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the ocean. Among the marine plant-like organisms the brown algae (Phaeophyta) are one of only five lineages of photosynthetic eukaryotes to have evolved complex multicellularity. Many of unusual and often unique features of brown algae are attributable to this singular evolutionary history. These adaptations are a reflection of the marine coastal environment which brown algae dominate in terms of biomass. Consequently, brown algae are of fundamental importance to oceanic ecology, geochemistry, and coastal industry. Our results indicate that boron is taken up by a facilitated diffusion mechanism against a considerable concentration gradient. Furthermore, in both Ectocarpus and Macrocystis some boron is most likely bound to cell wall constituent alginate and the photoassimilate mannitol located in sieve cells. Herein, we describe boron uptake, speciation, localization and possible biological function in two species of brown algae, Macrocystis pyrifera and Ectocarpus siliculosus.

  13. Ocean acidification weakens the structural integrity of coralline algae.

    Science.gov (United States)

    Ragazzola, Federica; Foster, Laura C; Form, Armin; Anderson, Philip S L; Hansteen, Thor H; Fietzke, Jan

    2012-09-01

    The uptake of anthropogenic emission of carbon dioxide is resulting in a lowering of the carbonate saturation state and a drop in ocean pH. Understanding how marine calcifying organisms such as coralline algae may acclimatize to ocean acidification is important to understand their survival over the coming century. We present the first long-term perturbation experiment on the cold-water coralline algae, which are important marine calcifiers in the benthic ecosystems particularly at the higher latitudes. Lithothamnion glaciale, after three months incubation, continued to calcify even in undersaturated conditions with a significant trend towards lower growth rates with increasing pCO2 . However, the major changes in the ultra-structure occur by 589 μatm (i.e. in saturated waters). Finite element models of the algae grown at these heightened levels show an increase in the total strain energy of nearly an order of magnitude and an uneven distribution of the stress inside the skeleton when subjected to similar loads as algae grown at ambient levels. This weakening of the structure is likely to reduce the ability of the alga to resist boring by predators and wave energy with severe consequences to the benthic community structure in the immediate future (50 years).

  14. Are anti-fouling effects in coralline algae species specific?

    Directory of Open Access Journals (Sweden)

    Alexandre Bigio Villas Bôas

    2004-03-01

    Full Text Available The crustose coralline algae are susceptible to be covered by other algae, which in turn can be affected by anti-fouling effects. In this study the hypothesis tested was that these algae can inhibit the growth of epiphytes in a species specific way. In the laboratory, propagules of Sargassum furcatum and Ulva fasciata were liberated and cultivated on pieces of coralline algae and slide covers (controls and their survival and growth were compared. Spongites and Hydrolithon significantly inhibited the growth of U. fasciata but not Sargassum. In the field, pieces of three species of live and dead coralline algae and their copies in epoxy putty discs were fixed on the rock. After one month epiphytic algae were identified and their dry mass quantified. Lithophyllum did not affect the epiphyte growth. In contrast Spongites and an unidentified coralline significantly inhibited the growth of Enteromorpha spp., Ulva fasciata and Hincksia mitchelliae. Colpomenia sinuosa was absent on all living crusts, but present on controls. Results show that the epiphyte-host relation depends on the species that are interacting. The sloughing of superficial cells of coralline crusts points to the possible action of physical anti-fouling effect, though a chemical one is not rejected.As algas calcárias crostosas são susceptíveis ao recobrimento por outras algas, entretanto, estas podem ser afetadas por efeitos anti-incrustantes. Neste estudo foi testada a hipótese de que estas algas possam inibir o crescimento somente de algumas espécies de epífitas. No laboratório, propágulos de Sargassum furcatum e Ulva fasciata foram liberados e cultivados sobre pedaços de algas calcárias e lamínulas de microscopia (controle e as suas sobrevivência e crescimento comparadas. Spongites e Hydrolithon inibiram significativamente o crescimento de U. fasciata, mas não de Sargassum. No campo, pedaços de três espécies de algas calcárias vivas, mortas e cópias destas em

  15. An updated comprehensive techno-economic analysis of algae biodiesel.

    Science.gov (United States)

    Nagarajan, Sanjay; Chou, Siaw Kiang; Cao, Shenyan; Wu, Chen; Zhou, Zhi

    2013-10-01

    Algae biodiesel is a promising but expensive alternative fuel to petro-diesel. To overcome cost barriers, detailed cost analyses are needed. A decade-old cost analysis by the U.S. National Renewable Energy Laboratory indicated that the costs of algae biodiesel were in the range of $0.53-0.85/L (2012 USD values). However, the cost of land and transesterification were just roughly estimated. In this study, an updated comprehensive techno-economic analysis was conducted with optimized processes and improved cost estimations. Latest process improvement, quotes from vendors, government databases, and other relevant data sources were used to calculate the updated algal biodiesel costs, and the final costs of biodiesel are in the range of $0.42-0.97/L. Additional improvements on cost-effective biodiesel production around the globe to cultivate algae was also recommended. Overall, the calculated costs seem promising, suggesting that a single step biodiesel production process is close to commercial reality.

  16. Cycloartane triterpenes from marine green alga Cladophora fascicularis

    Institute of Scientific and Technical Information of China (English)

    HUANG Xinping; ZHU Xiaobin; DENG Liping; DENG Zhiwei; LIN Wenhan

    2006-01-01

    Six cycloartanes were isolated from ethanol extract of marine green alga Cladophora fascicularis by column chromatography. Procedure of isolation and description of these compounds are given in this paper. The structures were elucidated as (1). 24-hydroperoxycycloart-25- en-3β-ol; (2).cycloart-25-en-3β 24-diol; (3). 25-hydroperoxycycloart-23-en-3β-ol; (4). cycloart-23-en-3β, 25-diol; (5).cycloart-23, 25-dien-3β-ol; and (6). cycloart-24-en-3β-ol by spectroscopic (MS, 1D and 2D NMR) data analysis. Cycloartane derivatives are widely distributed in terrestrial plants, but only few were obtained in the alga. All these compounds that have been isolated from terrestrial plants, were found in the marine alga for the first time.

  17. Benefits of using algae as natural sources of functional ingredients.

    Science.gov (United States)

    Ibañez, Elena; Cifuentes, Alejandro

    2013-03-15

    Algae have been suggested as a potential source of bioactive compounds to be used in the food and pharmaceutical industries. With the strong development of functional foods as a method to improve or maintain health, the exploration of new compounds with real health effects is now an intense field of research. The potential use of algae as source of functional food ingredients, such as lipids, proteins, polysaccharides, phenolics, carotenoids, etc., is presented, together with the different possibilities of improving valuable metabolites production either using the tools and the knowledge provided by marine biotechnology or improving the different factors involved in the production on a large scale of such metabolites. The bio-refinery concept is also presented as a way to improve the efficient use of algae biomass while favouring process sustainability.

  18. [Nutritive value of the spirulina algae (Spirulina maxima)].

    Science.gov (United States)

    Tejada de Hernández, I; Shimada, A S

    1978-06-01

    Nine experiments were conducted, five of them in vivo to determine the limiting amino acids and digestibility of spiruline algae for the rat, and four in vitro to determine the digestibility of the product in pepsin and ruminal liquid. None of the amino acids studied (lysine, methionine, histidine) added alone or in combination to 10% protein (either crude or true) diets provided exclusively by spiruline, seems to be limiting although the results could be masked by the low palatability and acceptability of the product by the rats. The apparent digestibility of the algae was 67.4%. For the in vitro tests, the algae were subjected to several physical or chemical treatments, and the digestibility of the resulting product determined by four different techniques. In no case did the tested treatments have any effect on its digestibility.

  19. GROWTH-REGULATORY ACTIVITY OF THE ALGAE EXTRACT

    Directory of Open Access Journals (Sweden)

    О. V. Кyrychenkо

    2013-10-01

    Full Text Available The growth-regulatory activity of the complex algae extract from Spirogira sp. at pre-so wing treatment of soybean seeds was studied in green-house and field experiments. It was shown that phytoextract has stimulated seeds germination on 12%, plants growth on 11–37%, soybean productivity increased on 6–27% as well as activated the development and functional ability of rhizospheric nitrogen-fixing microorganisms. The quantity of oligoazotrophes increased in 1,5–6,3 times, nitrogenase activity in 1,5–1,7 times. The possibility aspects of growth-regulatory activity of the algae extract in both plants and rhizospheric microorganisms is under discussion. Our results have confirmed the perspectives of practical use of the biological activity substances from the algae at soybean growing in order to increase plants productivity and improve microbiological indexes of soil.

  20. A look at diacylglycerol acyltransferases (DGATs) in algae.

    Science.gov (United States)

    Chen, Jit Ern; Smith, Alison G

    2012-11-30

    Triacylglycerols (TAGs) from algae are considered to be a potentially viable source of biodiesel and thereby renewable energy, but at the moment very little is known about the biosynthetic pathway in these organisms. Here we compare what is currently known in eukaryotic algal species, in particular the characteristics of algal diacylglycerol acyltransferase (DGAT), the last enzyme of de novo TAG biosynthesis. Several studies in plants and mammals have shown that there are two DGAT isoforms, DGAT1 and DGAT2, which catalyse the same reaction but have no clear sequence similarities. Instead, they have differences in functionality and spatial and temporal expression patterns. Bioinformatic searches of sequenced algal genomes reveal that most algae have multiple copies of putative DGAT2s, whereas other eukaryotes have single genes. Investigating whether these putative isoforms are indeed functional and whether they confer significantly different phenotypes to algal cells will be vital for future efforts to genetically modify algae for biofuel production.

  1. Extremophilic micro-algae and their potential contribution in biotechnology.

    Science.gov (United States)

    Varshney, Prachi; Mikulic, Paulina; Vonshak, Avigad; Beardall, John; Wangikar, Pramod P

    2015-05-01

    Micro-algae have potential as sustainable sources of energy and products and alternative mode of agriculture. However, their mass cultivation is challenging due to low survival under harsh outdoor conditions and competition from other, undesired, species. Extremophilic micro-algae have a role to play by virtue of their ability to grow under acidic or alkaline pH, high temperature, light, CO2 level and metal concentration. In this review, we provide several examples of potential biotechnological applications of extremophilic micro-algae and the ranges of tolerated extremes. We also discuss the adaptive mechanisms of tolerance to these extremes. Analysis of phylogenetic relationship of the reported extremophiles suggests certain groups of the Kingdom Protista to be more tolerant to extremophilic conditions than other taxa. While extremophilic microalgae are beginning to be explored, much needs to be done in terms of the physiology, molecular biology, metabolic engineering and outdoor cultivation trials before their true potential is realized.

  2. Designer proton-channel transgenic algae for photobiological hydrogen production

    Science.gov (United States)

    Lee, James Weifu

    2011-04-26

    A designer proton-channel transgenic alga for photobiological hydrogen production that is specifically designed for production of molecular hydrogen (H.sub.2) through photosynthetic water splitting. The designer transgenic alga includes proton-conductive channels that are expressed to produce such uncoupler proteins in an amount sufficient to increase the algal H.sub.2 productivity. In one embodiment the designer proton-channel transgene is a nucleic acid construct (300) including a PCR forward primer (302), an externally inducible promoter (304), a transit targeting sequence (306), a designer proton-channel encoding sequence (308), a transcription and translation terminator (310), and a PCR reverse primer (312). In various embodiments, the designer proton-channel transgenic algae are used with a gas-separation system (500) and a gas-products-separation and utilization system (600) for photobiological H.sub.2 production.

  3. Algae from the arid southwestern United States: an annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, W.H.; Gaines, S.R.

    1983-06-01

    Desert algae are attractive biomass producers for capturing solar energy through photosynthesis of organic matter. They are probably capable of higher yields and efficiencies of light utilization than higher plants, and are already adapted to extremes of sunlight intensity, salinity and temperature such as are found in the desert. This report consists of an annotated bibliography of the literature on algae from the arid southwestern United States. It was prepared in anticipation of efforts to isolate desert algae and study their yields in the laboratory. These steps are necessary prior to setting up outdoor algal culture ponds. Desert areas are attractive for such applications because land, sunlight, and, to some extent, water resources are abundant there. References are sorted by state.

  4. Importance of algae as a potential source of biofuel.

    Science.gov (United States)

    Singh, A K; Singh, M P

    2014-12-24

    Algae have a great potential source of biofuels and also have unique importance to reduce gaseous emissions, greenhouse gases, climatic changes, global warming receding of glaciers, rising sea levels and loss of biodiversity. The microalgae, like Scenedesmus obliquus, Neochloris oleabundans, Nannochloropsis sp., Chlorella emersonii, and Dunaliella tertiolecta have high oil content. Among the known algae, Scenedesmus obliquus is one of the most potential sources for biodiesel as it has adequate fatty acid (linolenic acid) and other polyunsaturated fatty acids. Bio—ethanol is already in the market of United States of America and Europe as an additive in gasoline. Bio—hydrogen is the cleanest biofuel and extensive efforts are going on to bring it to market at economical price. This review highlights recent development and progress in the field of algae as a potential source of biofuel.

  5. Characteristics of Red Algae Bioplastics/Latex Blends under Tension

    Directory of Open Access Journals (Sweden)

    M. Nizar Machmud

    2013-10-01

    Full Text Available Cassava, corn, sago and the other food crops have been commonly used as raw materials to produce green plastics. However, plastics produced from such crops cannot be tailored to fit a particular requirement due to their poor water resistance and mechanical properties. Nowadays, researchers are hence looking to get alternative raw materials from the other sustainable resources to produce plastics. Their recent published studies have reported that marine red algae, that has been already widely used as a raw material for producing biofuels, is one of the potential algae crops that can be turned into plastics. In this work, Eucheuma Cottonii, that is one of the red alga crops, was used as raw material to produce plastics by using a filtration technique. Selected latex of Artocarpus altilis and Calostropis gigantea was separately then blended with bioplastics derived from the red algae, to replace use of glycerol as plasticizer. Role of the glycerol and the selected latex on physical and mechanical properties of the red algae bioplastics obtained under a tensile test performed at room temperature are discussed. Tensile strength of some starch-based plastics collected from some recent references is also presented in this paperDoi: 10.12777/ijse.5.2.81-88 [How to cite this article: Machmud, M.N., Fahmi, R.,  Abdullah, R., and Kokarkin, C.  (2013. Characteristics of Red Algae Bioplastics/Latex Blends under Tension. International Journal of Science and Engineering, 5(2,81-88. Doi: 10.12777/ijse.5.2.81-88

  6. Homogeneity of Danish environmental and clinical isolates of Shewanella algae

    DEFF Research Database (Denmark)

    Vogel, Birte Fonnesbech; Holt, H.M.; Gerner-Smidt, P.;

    2000-01-01

    Danish isolates of Shewanella algae constituted by whole-cell protein profiling a very homogeneous group, and no clear distinction was seen between strains from the marine environment and strains of clinical origin. Although variation between all strains was observed by ribotyping and random...... amplified polymorphic DNA analysis, no clonal relationship between infective strains was found. From several patients, clonally identical strains of S. algae were reisolated up to 8 months after the primary isolation, indicating that the same strain may be able to maintain the infection....

  7. 大草履虫总DNA的提取方法比较%Comparation of DNA Extraction Methods of Paramecium Caudatum

    Institute of Scientific and Technical Information of China (English)

    朱艳芳; 胡建; 段永波

    2014-01-01

    快速而稳定地提取大草履虫的基因组DNA是进行后续分子生物学研究的前提。文章通过比较传统SDS法、CTABⅠ法和CTABⅡ法等提取大草履虫DNA的效果,进一步优化提取方法,获得快速稳定地提取大草履虫基因组DNA的方法。结果表明:用CTAB I法提取的DNA浓度低,杂质较多;CTABII提取的DNA电泳时检测不出条带;而SDS法提取的DNA在电泳时带型较整齐,无降解,且DNA的得率和纯度较高,但仍有蛋白质污染。针对蛋白质的去除,用SDS-蛋白酶K法和SDS-NaAc法来提取DNA,经过试验发现这2种方法都能够很好地去除蛋白质,所获DNA样品的纯度和得率都能用于进一步分子试验,而SDS-NaAc法更经济适用。%Isolation of genomic DNA is the precondition for molecular research on Paramecium caudatum. Traditional SDS method,CTABⅠmethod and CTABⅡmethod were employed to extract the genomic DNA from P. caudatum,Based on the experimental results,an optimized extraction procedure was established. The results showed that the DNA extracted by CTAB I method was poor in both purity and yield. The DNA extracted by CTABⅡ method was even undetectable,and the DNA extracted by the traditional SDS method performed better in yield and purity,but there were also protein impurities in DNA samples. In order to re-move protein impurities,proteinase K and NaAc were separately added to treat the DNA samples extracted by the traditional SDS method. These two reagents could effectively remove protein impurities,and the yield-ed DNA could satisfy the requirements of molecular research in both purity and yield. Considering the experi-mental cost,the SDS-NaAc method was more economical and can be used to extract the genomic DNA from P. caudatum.

  8. Effects of diuron and carbofuran pesticides in their pure and commercial forms on Paramecium caudatum: The use of protozoan in ecotoxicology.

    Science.gov (United States)

    Mansano, Adrislaine S; Moreira, Raquel A; Pierozzi, Mayara; Oliveira, Thiessa M A; Vieira, Eny M; Rocha, Odete; Regali-Seleghim, Mirna H

    2016-06-01

    Toxic effects of diuron and carbofuran on Paramecium caudatum were evaluated. Acute and chronic tests were conducted with diuron and carbofuran active ingredients and their commercial formulations, Diuron Nortox(®) 500 SC and Furadan(®) 350 SC, respectively. The sensitivity range of P. caudatum to reference substance sodium chloride was established. A preliminary risk assessment of diuron and carbofuran for Brazilian water bodies was performed. The tests indicated that toxicity of pure diuron and its commercial formulation was similar, while the commercial product carbofuran was more toxic than its pure form. In acute tests, readings were carried out at 2, 3, 4 and 6 h and showed an increase of mortality with increasing exposure time. The sensitivity of P. caudatum to NaCl ranged from 3.31 to 4.44 g L(-1), averaging 3.88 g L(-1). For diuron, the 6 h LC50 was 64.6 ± 3.3 mg L(-1) for its pure form and 62.4 ± 2.5 mg L(-1) for its commercial formulation. Carbofuran active ingredient was less toxic than that of diuron, presenting a 6 h LC50 of 142.0 ± 2.4 mg L(-1) for its pure form and 70.4 ± 2.2 mg L(-1) for its commercial product. Chronic tests showed that these pesticides cause significant decrease on population growth, generation number and biomass of P. caudatum. The 24 h IC50 was 7.10 ± 0.58 mg L(-1) for pure diuron, 6.78 ± 0.92 mg L(-1) for commercial diuron, 22.95 ± 3.57 mg L(-1) for pure carbofuran and 4.98 ± 0.62 mg L(-1) for commercial carbofuran. Preliminary risk assessment indicated that diuron and carbofuran present potential ecological risks for Brazilian water bodies. P. caudatum was a suitable and sensitive test organism to evaluate diuron and carbofuran toxicity to freshwater protozooplankton and, taking into account the relevant role of protozoans in aquatic environments, we strongly recommend its inclusion in ecotoxicological studies.

  9. Value of crops: Quantity, quality and cost price. [algae as a nutritional supplement

    Science.gov (United States)

    Meyer, C.

    1979-01-01

    Possibilities of using algae as a nutritional supplement are examined. The nutritional value and protein content of spirulines of blue algae are discussed. A cost analysis of growing them artificially is presented.

  10. Polyamine triggering of exocytosis in Paramecium involves an extracellular Ca(2+)/(polyvalent cation)-sensing receptor, subplasmalemmal Ca-store mobilization and store-operated Ca(2+)-influx via unspecific cation channels.

    Science.gov (United States)

    Klauke, N; Blanchard, M; Plattner, H

    2000-03-15

    The polyamine secretagogue, aminoethyldextran (AED), causes a cortical [Ca(2+)] transient in Paramecium cells, as analyzed by fluorochrome imaging. Our most essential findings are: (i) Cortical Ca(2+) signals also occur when AED is applied in presence of the fast Ca(2+) chelator, BAPTA. (ii) Extracellular La(3+) application causes within seconds a rapid, reversible fluorescence signal whose reversibility can be attributed to a physiological [Ca(2+)](i) transient (while injected La(3+) causes a sustained fluorescence signal). (iii) Simply increasing [Ca(2+)](o) causes a similar rapid, short-lived [Ca(2+)](i) transient. All these phenomena, (i-iii), are compatible with activation of an extracellular "Ca(2+)/(polyvalent cation)-sensing receptor" known from some higher eukaryotic systems, where this sensor (responding to Ca(2+), La(3+) and some multiply charged cations) is linked to cortical calcium stores which, thus, are activated. In Paramecium, such subplasmalemmal stores ("alveolar sacs") are physically linked to the cell membrane and they can also be activated by the Ca(2+) releasing agent, 4-chloro-m-cresol, just like in Sarcoplasmic Reticulum. Since this drug causes a cortical Ca(2+) signal also in absence of Ca(2+)(o) we largely exclude a "Ca(2+)-induced Ca(2+) release" (CICR) mechanism. Our finding of increased cortical Ca(2+) signals after store depletion and re-addition of extracellular Ca(2+) can be explained by a "store-operated Ca(2+) influx" (SOC), i.e., a Ca(2+) influx superimposing store activation. AED stimulation in presence of Mn(2+)(o) causes fluorescence quenching in Fura-2 loaded cells, indicating involvement of unspecific cation channels. Such channels, known to occur in Paramecium, share some general characteristics of SOC-type Ca(2+) influx channels. In conclusion, we assume the following sequence of events during AED stimulated exocytosis: (i) activation of an extracellular Ca(2+)/polyamine-sensing receptor, (ii) release of Ca(2+) from

  11. Epilithic algae from caves of the Krakowsko-Częstochowska Upland (Southern Poland)

    OpenAIRE

    Joanna Czerwik-Marcinkowska; Teresa Mrozińska

    2011-01-01

    This paper describes the first study of algae assemblages in 20 caves in the Krakowsko-Częstochowska Upland (Southern Poland), in the period between 2005-2006. The investigations showed mostly on epilithic algae and their subaeric habitats (rock faces within caves and walls at cave entrances). The morphological and cytological variability of algae were studied in fresh samples, in cultures grown on agar plates and in SPURR preparations. A total of 43 algae species was identified, mostly epili...

  12. Research of Influence of Aniline on the Growth of Ocean Algae

    Institute of Scientific and Technical Information of China (English)

    QIU Haiyuan; WANG Xian

    2005-01-01

    This article discusses the interaction of aniline and ocean algae based on the standard appraisal method of chemical medicine for algae toxicity. It is showed by experimental results that aniline has pretty toxic effects on algae. Suspended substances in water can offset some effects of aniline. It also discusses the dynamic constant of first order degradation reaction rate of algae on aniline from the point of view of chemical dynamics.

  13. Where Have All the Algae Gone, or, How Many Kingdoms Are There?

    Science.gov (United States)

    Blackwell, Will H.; Powell, Martha J.

    1995-01-01

    Examined 10 introductory college-level, general biology survey textbooks for the coverage of algae to assess the efficacy of coverage. Describes a proposal of seven kingdoms and discusses the disposition of algae among five of these kingdoms. Contends that textbooks should highlight the concept of algae across the five kingdoms. Contains 59…

  14. A review of the taxonomical and ecological studies on Netherlands’ Algae

    NARCIS (Netherlands)

    Koster, Joséphine Th.

    1939-01-01

    The earliest account of the Netherlands’ Algae appeared in 1781 in D. de Gorter, Flora VII Prov. Belgii foederati indigen. Here, however, in the Algae lichens and liverworts have been incorporated. The true Algae, of which 35 are enumerated, are principally marine, though also aërophytical and fresh

  15. Food and feed products from micro-algae: Market opportunities and challenges for the EU

    NARCIS (Netherlands)

    Vigani, M.; Parisi, C.; Rodriguez-Cerezo, E.; Barbosa, M.J.; Sijtsma, L.; Ploeg, M.; Enzing, C.

    2015-01-01

    Micro-algae are a new and promising source of nutrients. The main products obtainable are dried algae with high nutrients content and high-value compounds such as fatty acids, pigments and anti-oxidants. This paper analyses the market and the economic opportunities of micro-algae-based food and feed

  16. Critical conditions for ferric chloride-induced flocculation of freshwater algae.

    Science.gov (United States)

    Wyatt, Nicholas B; Gloe, Lindsey M; Brady, Patrick V; Hewson, John C; Grillet, Anne M; Hankins, Matthew G; Pohl, Phillip I

    2012-02-01

    The effects of algae concentration, ferric chloride dose, and pH on the flocculation efficiency of the freshwater algae Chlorella zofingiensis can be understood by considering the nature of the electrostatic charges on the algae and precipitate surfaces. Two critical conditions are identified which, when met, result in flocculation efficiencies in excess of 90% for freshwater algae. First, a minimum concentration of ferric chloride is required to overcome the electrostatic stabilization of the algae and promote bridging of algae cells by hydroxide precipitates. At low algae concentrations, the minimum amount of ferric chloride required increases linearly with algae concentration, characteristic of flocculation primarily through electrostatic bridging by hydroxide precipitates. At higher algae concentrations, the minimum required concentration of ferric chloride for flocculation is independent of algae concentration, suggesting a change in the primary flocculation mechanism from bridging to sweep flocculation. Second, the algae must have a negative surface charge. Experiments and surface complexation modeling show that the surface charge of C. zofingiensis is negative above a pH of 4.0 ± 0.3 which agrees well with the minimum pH required for effective flocculation. These critical flocculation criteria can be extended to other freshwater algae to design effective flocculation systems.

  17. New methodologies for the integration of power plants with algae ponds

    NARCIS (Netherlands)

    Schipper, K.; Gijp, S. van der; Stel, R.W van der; Goetheer, E.L.V.

    2013-01-01

    It is generally recognized that algae could be an interesting option for reducing CO2 emissions. Based on light and CO2, algae can be used for the production various economically interesting products. Current algae cultivation techniques, however, still present a number of limitations. Efficient fee

  18. Distribution and biomass estimation of shell-boring algae in the intertidal area at Goa India

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.; Sharma, S.; Lande, V.

    The distribution and frequency of shell-boring green and blue-green algae in the intertidal at Goa, India were studied. The green alga Gomontia sp. and the blue green algae Hyella caespitosa Bornet et Flahault, H. gigas Lucas et Golubic...

  19. Isolasi dan Identifikasi Protein Bioaktif Alga Merah Eucheuma cottonii serta Potensinya Sebagai Antikanker

    OpenAIRE

    Ismail, Ayu Indayanti

    2014-01-01

    Isolasi dan Identifikasi Senyawa Protein Bioaktif dari Alga Merah Eucheuma cottoni dari Teluk Laikang Kabupaten Takalar Sulawesi Selatan telah dilakukan. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi senyawa protein bioaktif dari alga merah Eucheuma cottonii serta potensinya sebagai antikanker. Metode penelitian yang digunakan adalah metode eksperimental dengan tahapan perlakuan yaitu isolasi senyawa protein bioaktif dari alga merah Eucheuma cottonii melalui proses lisis, ...

  20. Effect of sonication frequency on the disruption of algae.

    Science.gov (United States)

    Kurokawa, Masaki; King, Patrick M; Wu, Xiaoge; Joyce, Eadaoin M; Mason, Timothy J; Yamamoto, Ken

    2016-07-01

    In this study, the efficiency of ultrasonic disruption of Chaetoceros gracilis, Chaetoceros calcitrans, and Nannochloropsis sp. was investigated by applying ultrasonic waves of 0.02, 0.4, 1.0, 2.2, 3.3, and 4.3 MHz to algal suspensions. The results showed that reduction in the number of algae was frequency dependent and that the highest efficiency was achieved at 2.2, 3.3, and 4.3MHz for C. gracilis, C. calcitrans, and Nannochloropsis sp., respectively. A review of the literature suggested that cavitation, rather than direct effects of ultrasonication, are required for ultrasonic algae disruption, and that chemical effects are likely not the main mechanism for algal cell disruption. The mechanical resonance frequencies estimated by a shell model, taking into account elastic properties, demonstrated that suitable disruption frequencies for each alga were associated with the cell's mechanical properties. Taken together, we consider here that physical effects of ultrasonication were responsible for algae disruption.

  1. Free Sterols of the red alga Chondria armata (Kutz.) Okamura

    Digital Repository Service at National Institute of Oceanography (India)

    Govenkar, M.B.; Wahidullah, S.

    The free sterols of the red alga, Chondria armata have been identified by means of NMR, EIMS and GCMS analyses. The mixture contained besides cholesterol, C sub(28) and C sub(29) saturated as well as unsaturated components. The major component...

  2. Photo-producing Hydrogen with Marine Green Algae

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Hydrogen is often hailed as a potential source of unlimited clean power.It can be produced with green algae from water and solar energy through a process called "photobiological hydrogen production."Although its efficiency is rather low at present, scientists believe,an increase to 10% would make this process economically feasible.

  3. Alga-lysing bioreactor and the dominant bacteria strain

    Institute of Scientific and Technical Information of China (English)

    PEI Hai-yan; HU Wen-rong; MU Rui-min; LI Xiao-cai

    2007-01-01

    Alga-lysing bacteria have been paid much attention to in recent years. In this study, the alga-lysing strain P05 which was isolated from an immobilizing biosystem was immobilized by coke and elastic filler, forming two biological reactors. The removal efficiencies of algae, NH3-N and organic matter using the two reactors were studied. The results showed that strain P05 was an ideal algal-lysing bacteria strain because it was easy to be immobilized by coke and elastic filler which are of cheap, low biodegradability and the simple immobilization procedure. After 7 d filming, the biological film could be formed and the reactors were used to treat the eutrophic water. These two reactors were of stability and high effect with low cost and easy operation. The optimal hydraulic retention time (HRT) of each reactor was 4 h. The algae removal rates were 80.38% and 82.1% (in term of Chl-a) of coke reactor and filler reactor, respectively. And that of NH3-N were 52.3% and 52.7%. The removal rates of CODMn were 39.03% and 39.64%. The strain P05 was identified as Bacillus sp. by PCR amplification of the 16S rRNA gene, BLAST analysis, and comparison with sequences in the GenBank nucleotide database.

  4. A REVIEW OF HEAVY METAL ADSORPTION BY MARINE ALGAE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Accumulation of heavy metals by algae had been studied extensively for biomonitoring or bioremediation purposes. Having the advantages of low cost raw material, big adsorbing capacity, no secondary pollution, etc., algae may be used to treat industrial water containing heavy metals. The adsorption processes were carried out in two steps: rapid physical adsorption first, and then slow chemical adsorption. pH is the major factor influencing the adsorption. The Freundlich equation fitted very well the adsorption isotherms. The uptake decreased with increasing ionic strength. The principal mechanism of metallic cation sequestration involves the formation of complexes between a metal ion and functional groups on the surface or inside the porous structure of the biological material. The carboxyl groups of alginate play a major role in the complexation. Different species of algae and the algae of the same species may have different adsorption capacity. Their selection affinity for heavy metals was the major criterion for the screening of a biologic adsorbent to be used in water treatment. The surface complex formation model (SCFM) can solve the equilibrium and kinetic problems in the biosorption.

  5. A Novel Lanostanoid Lactone From the Alga Hypnea cerricornis

    Institute of Scientific and Technical Information of China (English)

    XU, Xiao-Hua; CHEN, Xiao; LU, Jian-Hua; YAO, Guang-Min; LI, Yah-Ming; ZE NG, Long-Mei

    2001-01-01

    A novel lanntanoid lactone (1) was first isolated fron the Alga Hypnen cerriconis collected from the Xisha Islands in theSouth China Sea. The structure of 1 was determined on spectral evidence as 5a-tansta-8-en-3β,22ζ-dihydroxy-22 (R), 24(S)-lactone.

  6. Fuzzy Pattern Recognition System for Detection of Alga Distribution

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To realize the on-line measurement and make analysis on the density of algae and their cluster distribution, the fluorescent detection and fuzzy pattern recognition techniques are used. The principle of fluorescent fiber-optic detection is given as well as the method of fuzzy feature extraction using a class of neural network.

  7. Decreased abundance of crustose coralline algae due to ocean acidification

    Science.gov (United States)

    Kuffner, Ilsa B.; Andersson, Andreas J; Jokiel, Paul L.; Rodgers, Ku'ulei S.; Mackenzie, Fred T.

    2008-01-01

    Owing to anthropogenic emissions, atmospheric concentrations of carbon dioxide could almost double between 2006 and 2100 according to business-as-usual carbon dioxide emission scenarios1. Because the ocean absorbs carbon dioxide from the atmosphere2, 3, 4, increasing atmospheric carbon dioxide concentrations will lead to increasing dissolved inorganic carbon and carbon dioxide in surface ocean waters, and hence acidification and lower carbonate saturation states2, 5. As a consequence, it has been suggested that marine calcifying organisms, for example corals, coralline algae, molluscs and foraminifera, will have difficulties producing their skeletons and shells at current rates6, 7, with potentially severe implications for marine ecosystems, including coral reefs6, 8, 9, 10, 11. Here we report a seven-week experiment exploring the effects of ocean acidification on crustose coralline algae, a cosmopolitan group of calcifying algae that is ecologically important in most shallow-water habitats12, 13, 14. Six outdoor mesocosms were continuously supplied with sea water from the adjacent reef and manipulated to simulate conditions of either ambient or elevated seawater carbon dioxide concentrations. The recruitment rate and growth of crustose coralline algae were severely inhibited in the elevated carbon dioxide mesocosms. Our findings suggest that ocean acidification due to human activities could cause significant change to benthic community structure in shallow-warm-water carbonate ecosystems.

  8. New bromotriterpene polyethers from the Indian alga Chondria armata

    Digital Repository Service at National Institute of Oceanography (India)

    Ciavatta, M.L.; Wahidullah, S.; De; Scognamiglio, G.; Cimino, G.

    Six new bromotriterpene polyethers, armatol A-F (1-6), with a rearranged carbon skeleton, were isolated from the Indian Ocean red alga Chondria armata. The structures were characterized by spectroscopic techniques, in particular 1D- and 2D-NMR...

  9. Meteorological effects on variation of airborne algae in Mexico

    Science.gov (United States)

    Rosas, Irma; Roy-Ocotla, Guadalupe; Mosiño, Pedro

    1989-09-01

    Sixteen species of algae were collected from 73.8 m3 of air. Eleven were obtained in Minatitlán and eleven in México City. The data show that similar diversity occurred between the two localities, in spite of the difference in altitude. This suggests that cosmopolitan airborne microorganisms might have been released from different sources. Three major algal divisions (Chlorophyta, Cyanophyta and Chrysophyta) formed the airborne algal group. Also, a large concentration of 2220 algae m-3 was found near sea-level, while lower amounts were recorded at the high altitude of México City. The genera Scenedesmus, Chlorella and Chlorococcum dominated. Striking relationships were noted between the concentration of airborne green and blue-green algae, and meteorological conditions such as rain, vapour pressure, temperature and winds for different altitudes. In Minatitlán a linear relationship was established between concentration of algae and both vapour pressure (mbar) and temperature (° C), while in México City the wind (m s-1) was associated with variations in the algal count.

  10. [Phycobiliproteins of blue-green, red and cryptophytic algae].

    Science.gov (United States)

    Stadnichuk, I N; Gusev, M V

    1979-04-01

    The present-day concepts on phycobiliproteins, the protein pigments of blue-green, red and cryptophyte algae are reviewed. The functions, distribution, localization, physico-chemical, spectral and immunochemical properties of phycobiliproteins are described. The properties of the polypeptide protein subunits and the composition and chemical structure of chromophores as well as their binding to the apoprotein molecules are discussed.

  11. Algas vene kirjanduse nädal / Raimu Hanson

    Index Scriptorium Estoniae

    Hanson, Raimu, 1957-

    2008-01-01

    22. septembril algas Tartu Linnaraamatukogus vene kirjanduse nädal Inga Ivanova raamatu "Kadunud koerte saladus" esitlusega; 24. sept. toimub Igor Kotjuhi autoriõhtu; 26.-28. toimub Tartu Ülikoolis vene kirjandusele pühendatud rahvusvaheline teaduskonverents. Raamatukogust saab osta ka venekeelseid raamatuid

  12. Emulsion properties of algae soluble protein isolate from Tetraselmis sp.

    NARCIS (Netherlands)

    Schwenzfeier, A.; Helbig, A.; Wierenga, P.A.; Gruppen, H.

    2013-01-01

    To study possible applications of microalgae proteins in foods, a colourless, protein-rich fraction was isolated from Tetraselmis sp. In the present study the emulsion properties of this algae soluble protein isolate (ASPI) were investigated. Droplet size and droplet aggregation of ASPI stabilized o

  13. A New Bromophenol from the Brown Alga Leathesia nana

    Institute of Scientific and Technical Information of China (English)

    Xiu Li XU; Xiao FAN; Fu Hang SONG; Jie Lu ZHAO; Li Jun HAN; Jian Gong SHI

    2004-01-01

    A novel bromophenol was isolated from ethanolic extract of the brown alga Leathesia nana S.et G. The structure was elucidated as (E)-3-(2,3-dibromo-4,5-dihydroxyphenyl)-2-methyl- propenal by spectroscopic methods including IR, HREIMS, 1D and 2D NMR techniques.

  14. Study of ecotoxicity of silver nanoparticles using algae

    Science.gov (United States)

    Kustov, L. M.; Abramenko, N. B.

    2016-11-01

    Silver nanoparticles have been prepared and tested for their ecotoxicity using Chlorella vulgaris Beijer. algae as a hydrobiotic test organism and a photometric method of control. The toxicity was supposed to originate from Ag+ ions released into the aqueous solution. Also, the toxicity of the stabilizing agent was found to be comparable to that of silver nanoparticles.

  15. Controlled artificial upwelling in a fjord to combat toxic algae

    Science.gov (United States)

    McClimans, T. A.; Hansen, A. H.; Fredheim, A.; Lien, E.; Reitan, K. I.

    2003-04-01

    During the summer, primary production in the surface layers of some fjords depletes the nutrients to the degree that some arts of toxic algae dominate the flora. We describe an experiment employing a bubble curtain to lift significant amounts of nutrient-rich seawater to the light zone and provide an environment in which useful algae can survive. The motivation for the experiment is to provide a local region in which mussels can be cleansed from the effects of toxic algae. Three 100-m long, perforated pipes were suspended at 40 m depth in the Arnafjord, a side arm of the Sognefjord. Large amounts of compressed air were supplied during a period of three weeks. The deeper water mixed with the surface water and flowed from the mixing region at 5 to 15 m depth. Within a few days, the mixture of nutrient-rich water covered most of the inner portion of Arnafjord. Within 10 days, the plankton samples showed that the artificial upwelling produced the desired type of algae and excluded the toxic blooms that were occurring outside the manipulated fjord arm. The project (DETOX) is supported by the Norwegian ministries of Fisheries, Agriculture and Public Administration.

  16. A review of heavy metal adsorption by marine algae

    Science.gov (United States)

    Pan, Jin-Fen; Lin, Rong-Gen; Ma, Li

    2000-09-01

    Accumulation of heavy metals by algae had been studied extensively for biomonitoring or bioremediation purposes. Having the advantages of low cost raw material, big adsorbing capacity, no secondary pollution, etc., algae may be used to treat industrial water containing heavy metals. The adsorption processes were carried out in two steps: rapid physical adsorption first, and then slow chemical adsorption. pH is the major factor influencing the adsorption. The Freundlich equation fitted very well the adsorption isotherms. The uptake decreased with increasing ionic strength. The principal mechanism of metallic cation sequestration involves the formation of complexes between a metal ion and functional groups on the surface or inside the porous structure of the biological material. The carboxyl groups of alginate play a major role in the complexation. Different species of algae and the algae of the same species may have different adsorption capacity. Their selection affinity for heavy metals was the major criterion for the screening of a biologic adsorbent to be used in water treatment. The surface complex formation model (SCFM) can solve the equilibrium and kinetic problems in the biosorption.

  17. Ecological assessments with algae: a review and synthesis.

    Science.gov (United States)

    Stevenson, Jan

    2014-06-01

    Algae have been used for a century in environmental assessments of water bodies and are now used in countries around the world. This review synthesizes recent advances in the field around a framework for environmental assessment and management that can guide design of assessments, applications of phycology in assessments, and refinements of those applications to better support management decisions. Algae are critical parts of aquatic ecosystems that power food webs and biogeochemical cycling. Algae are also major sources of problems that threaten many ecosystems goods and services when abundances of nuisance and toxic taxa are high. Thus, algae can be used to indicate ecosystem goods and services, which complements how algal indicators are also used to assess levels of contaminants and habitat alterations (stressors). Understanding environmental managers' use of algal ecology, taxonomy, and physiology can guide our research and improve its application. Environmental assessments involve characterizing ecological condition and diagnosing causes and threats to ecosystems goods and services. Recent advances in characterizing condition include site-specific models that account for natural variability among habitats to better estimate effects of humans. Relationships between algal assemblages and stressors caused by humans help diagnose stressors and establish targets for protection and restoration. Many algal responses to stressors have thresholds that are particularly important for developing stakeholder consensus for stressor management targets. Future research on the regional-scale resilience of algal assemblages, the ecosystem goods and services they provide, and methods for monitoring and forecasting change will improve water resource management.

  18. 草履虫的采集分离、培养及保存新方法研究概述%An Overview of the New Methods of Collecting,Separating,Culturing and Preserving Paramecium

    Institute of Scientific and Technical Information of China (English)

    齐建红

    2011-01-01

    对动物学实验教学中的草履虫材料的采集分离、培养方法进行了探讨,同时对草履虫进行了保存方法的研究,随时为高等院校及中学生物学实验课常用的实验材料进行及时培养,为教学科研提供帮助.%This study is an overview of the new methods of collecting,separating culturing and preserving Paramecium in the experimental teaching of zoology.The methods addressed are supposed to be instrumental for easier culture of experimental materials in biology classes both in colleges and middle schools and for teaching and research.

  19. The effect in Sodium Dodecylbenzenesulfonate(DBS) on the population quantity of Paramecium aurelia%十二烷基苯磺酸钠对双小核草履虫种群数量的影响

    Institute of Scientific and Technical Information of China (English)

    李莉; 娄玉乾; 王文彬; 冯金儒; 张茜

    2011-01-01

    在实验条件下,研究了十二烷基苯磺酸钠(DBS)对双小核草履虫(Paramecium aurelia)种群数量的影响.结果表明,较高浓度的DBS对双小核草履虫具有急性毒性效应,其24 h-LC50为9.74 mg/L;仿生活污水的DBS浓度(0.2~1.0 mg/L)和0 mg/L中双小核草履虫增长率之间无显著性差异(P>0.05),说明含有1.0 mg/L以下浓度DBS的生活污水对双小核草履虫的种群数量增长无显著影响.

  20. MORPHOLOGICAL ANATOMICAL AND PHITOCHEMICAL CHARACTERISTICS OF SOME ALGAE

    Directory of Open Access Journals (Sweden)

    N. S. Kaysheva

    2014-01-01

    Full Text Available Morphological and anatomical features of thalluses of brown (Laminaria saccharina, Fucus vesiculosus and red (Ahnfeltia plicata algae, procured at a coastal strip of the Northern basin in gulfs of Ura-Guba and Palkina-Guba at different depths. Compliance of Fucus and Ahnfeltia with pharmacopoeial norms and merchandising indices for Laminaria was established, except for high concentration of sand in Ahnfeltia thalluses. The identity of algae between each other was shown based on the results of qualitative analysis on polysaccharides, alginic acids, reducing sugars, iodine, mannitol, amino acids presence. Quantitative content of polysaccharides, alginic acids, reducing sugars, pentosans, iodine, cellulose, mannitol, proteins, lipids, agar was determined. In comparison with Fucus and Ahnfeltia higher concentration of the following content was noted in Laminaria: alginic acids (1.4 and 5.75 times higher, polysaccharides (1.3 and 1.4 times, iodine (4.5 and 1.8 times, mannatol (1.5 and 2.5 times (data received is statistically reliable. Impropriety of storm algae for processing was shown as law quality raw material. The highest concentration of active substances was revealed in Laminaria thalluses which were procured at the depth of 10 m in a period from September to October. Active accumulation of sodium, potassium, calcium, iron, magnesium, manganese corresponding to similar sea water composition was established in algae. Mathematical equations of regression between protein and manganese, protein and iron content in algae were deduced. Under proper conditions of drying and storage high quality of the materials can be preserved during 3 years. Based on the findings of photochemical researches, taking into account squares of plantations and possible exploitation stocks, the possibility and prospectivity of industrial processing of Fucus vesiculosus and Ahnfeltia plicata together with Laminaria saccharina as plant sources of polysaccharides (mainly

  1. Site‐directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia

    Directory of Open Access Journals (Sweden)

    E. Wyroba

    2016-04-01

    Full Text Available Protein products of the paralogous genes resulting from the whole genome duplication may acquire new function. The role of post‐translational modifications (PTM in proper targeting of Paramecium Rab7b paralogue – distinct from that of Rab7a directly involved in phagocytosis ‐ was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala200 resulted in diminished incorporation of [P32] by 37.4% and of 32 [C14–]UDP‐glucose by 24%, respectively, into recombinant Rab7b_200 in comparison to the non‐mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells contrary to non‐ mutagenized recombinant Rab7b correctly incorporated in the cytostome area. We identified the peptide ion at m/z=677.63+ characteristic for the glycan group attached to Thr200 in Rab7b using nano LC‐MS/MS and comparing the peptide map of this protein with that after deglycosylation with the mixture of five enzymes of different specificity. Based on the mass of this peptide ion and quantitative radioactive assays with [P32]and  [C14‐]UDP‐ glucose, the suggested composition of the adduct attached to Thr200 might be (Hex1(HexNAc1(Phos3 or (HexNAc1 (Deoxyhexose1 (Phos1 (HexA1. These data indicate that PTM of Thr200 located in the hypervariable C‐region of Rab7b in Paramecium is crucial for the proper localization/function of this protein. Moreover, these proteins differ also in other PTM: the number of phosphorylated amino acids in Rab7b is much higher than in Rab7a.   

  2. Site-directed mutagenesis, in vivo electroporation and mass spectrometry in search for determinants of the subcellular targeting of Rab7b paralogue in the model eukaryote Paramecium octaurelia.

    Science.gov (United States)

    Wyroba, E; Kwaśniak, P; Miller, K; Kobyłecki, K; Osińska, M

    2016-01-01

    Protein products of the paralogous genes resulting from the whole genome duplication may acquire new function. The role of post-translational modifications (PTM) in proper targeting of Paramecium Rab7b paralogue - distinct from that of Rab7a directly involved in phagocytosis - was studied using point mutagenesis, proteomic analysis and double immunofluorescence after in vivo electroporation of the mutagenized protein. Here we show that substitution of Thr200 by Ala200 resulted in diminished incorporation of [P32] by 37.4% and of 32 [C14-]UDP-glucose by 24%, respectively, into recombinant Rab7b_200 in comparison to the non-mutagenized control. Double confocal imaging revealed that Rab7b_200 was mistargeted upon electroporation into living cells contrary to non- mutagenized recombinant Rab7b correctly incorporated in the cytostome area. We identified the peptide ion at m/z=677.63+ characteristic for the glycan group attached to Thr200 in Rab7b using nano LC-MS/MS and comparing the peptide map of this protein with that after deglycosylation with the mixture of five enzymes of different specificity. Based on the mass of this peptide ion and quantitative radioactive assays with [P32]and  [C14-]UDP- glucose, the suggested composition of the adduct attached to Thr200 might be (Hex)1(HexNAc)1(Phos)3 or (HexNAc)1 (Deoxyhexose)1 (Phos)1 (HexA)1. These data indicate that PTM of Thr200 located in the hypervariable C-region of Rab7b in Paramecium is crucial for the proper localization/function of this protein. Moreover, these proteins differ also in other PTM: the number of phosphorylated amino acids in Rab7b is much higher than in Rab7a.

  3. Study on the concentration and seasonal variation of inorganic elements in 35 species of marine algae

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Yan, X.J.

    1998-01-01

    The concentrations of five major and 28 trace elements in 35 marine algae collected along the coast of China were determined by instrumental neutron activation analysis. The concentrations of halogens, rare earth elements and many transition metal elements in marine algae are remarkably higher than...... those in terrestrial plants. The concentration factors for 31 elements in all collected algae were calculated, those for tri- and tetra-valent elements were higher than those of the mono- and di-valent elements in marine algae. The biogeochemical characteristics of inorganic elements in marine algae...

  4. Determination of aliphatic hydrocarbons in the alga Himanthalia elongata.

    Science.gov (United States)

    Punín Crespo, M O; Lage Yusty, M A

    2004-02-01

    The algae considered new foods according to Regulation CE 258/97 need a guarantee of their healthfulness before being in the European market. In this work ten samples of the brown alga Himanthalia elongata have been analyzed with the aim of verifying the absence of aliphatic hydrocarbons, due to the ability of the macroalgae to capture lipophilic organic compounds of the marine water coming from accidental or continuous leaks of raw oil and refined products, which happen each year with the growth of the industrialization and the demand of energy. The fat of the samples were Soxhlet extracted using hexane:dichloromethane (1:1) for 7h. The organic fractions were purified using silica microcolumns. The identification and quantification of the aliphatic hydrocarbons have been carried out using gas chromatography (GC) with flame ionization detector (FID). The total hydrocarbon content was between 14.8 and 40.2 microg g(-1) dry weight.

  5. Sodium, potassium-atpases in algae and oomycetes.

    Science.gov (United States)

    Barrero-Gil, Javier; Garciadeblás, Blanca; Benito, Begoña

    2005-08-01

    We have investigated the presence of K(+)-transporting ATPases that belong to the phylogenetic group of animal Na(+),K(+)-ATPases in the Pythium aphanidermatum Stramenopile oomycete, the Porphyra yezoensis red alga, and the Udotea petiolata green alga, by molecular cloning and expression in heterologous systems. PCR amplification and search in EST databases allowed one gene to be identified in each species that could encode ATPases of this type. Phylogenetic analysis of the sequences of these ATPases revealed that they cluster with ATPases of animal origin, and that the algal ATPases are closer to animal ATPases than the oomycete ATPase is. The P. yezoensis and P. aphanidermatum ATPases were functionally expressed in Saccharomyces cerevisiae and Escherichia coli alkali cation transport mutants. The aforementioned cloning and complementary searches in silicio for H(+)- and Na(+),K(+)-ATPases revealed a great diversity of strategies for plasma membrane energization in eukaryotic cells different from typical animal, plant, and fungal cells.

  6. Marine Polysaccharides from Algae with Potential Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Maria Filomena de Jesus Raposo

    2015-05-01

    Full Text Available There is a current tendency towards bioactive natural products with applications in various industries, such as pharmaceutical, biomedical, cosmetics and food. This has put some emphasis in research on marine organisms, including macroalgae and microalgae, among others. Polysaccharides with marine origin constitute one type of these biochemical compounds that have already proved to have several important properties, such as anticoagulant and/or antithrombotic, immunomodulatory ability, antitumor and cancer preventive, antilipidaemic and hypoglycaemic, antibiotics and anti-inflammatory and antioxidant, making them promising bioactive products and biomaterials with a wide range of applications. Their properties are mainly due to their structure and physicochemical characteristics, which depend on the organism they are produced by. In the biomedical field, the polysaccharides from algae can be used in controlled drug delivery, wound management, and regenerative medicine. This review will focus on the biomedical applications of marine polysaccharides from algae.

  7. Green Algae as Model Organisms for Biological Fluid Dynamics.

    Science.gov (United States)

    Goldstein, Raymond E

    2015-01-01

    In the past decade the volvocine green algae, spanning from the unicellular Chlamydomonas to multicellular Volvox, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 μm to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

  8. Bioactivities from Marine Algae of the Genus Gracilaria

    OpenAIRE

    José M. Barbosa-Filho; Maria de Fátima V. de Souza; Rodrigues, Luis C.; Athayde-Filho, Petrônio F.; Lira, Narlize S.; Camila De A. Montenegro; Gedson R. De M. Lima; Batista,Leônia M.; Heloina de S. Falcão; Cynthia Layse F. De Almeida

    2011-01-01

    Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested fo...

  9. Enhanced Genetic Tools for Engineering Multigene Traits into Green Algae

    OpenAIRE

    Rasala, Beth A; Syh-Shiuan Chao; Matthew Pier; Daniel J Barrera; Mayfield, Stephen P.

    2014-01-01

    Transgenic microalgae have the potential to impact many diverse biotechnological industries including energy, human and animal nutrition, pharmaceuticals, health and beauty, and specialty chemicals. However, major obstacles to sophisticated genetic and metabolic engineering in algae have been the lack of well-characterized transformation vectors to direct engineered gene products to specific subcellular locations, and the inability to robustly express multiple nuclear-encoded transgenes withi...

  10. Freshwater Cyanobacteria (Blue-Green Algae) Toxins: Isolation and Characterization

    Science.gov (United States)

    1985-10-01

    9, 1985. Toxic peptides of freshwater cyanobacteria (blue-green algae) from two European Hicr tis aegi and one Canadian &nAnbaflo s- agua were...8217Algal toxin from Potable Water Supplies: A Pilot Plant Investi- gation. p. 26 In Technical papers presented at the Tenth Federal Convention of the...W.H. Watson. Studies on aphantoxin from A12han izomenon flos- aguae in New Hampshire. In: Carmichael, W.W. (ed.) The Water Envir’onment: Algal Toxins and

  11. Toxicity of Fluoranthene and Its Biodegradation by Cyclotella caspia Alga

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Fluoranthene is one of the polynuclear aromatic hydrocarbons with four benzene rings. Because of its toxicity,mutagenicity, and carcinogenicity, fluoranthene is on the black lists of 129 and 68 priority pollutants established by US Environmental Protection Agency and the People's Republic of China, respectively. In recent years, the amount of fluoranthene in the aquatic environment has been increasing with increases in anthropogenic discharge. Based on the biological investigation of tidal water in the Futian mangrove, Cyclotella caspia was selected as the dominant algal species to determine the toxicity of fluoranthene towards C. caspia alga and to investigate the biodegradation of fluoranthene by C. caspia under pure culture. The toxicity experiment showed that the 96-h EC50 vaiue for fluoranthene was 0.2 mg/mL. Four parameters, namely C. caspia algal growth rate,chlorophyll (Chi) a content, cell morphology, and superoxide dismutase (SOD) activity, were chosen as indices of toxicity and were measured at 6 d (144 h). The results showed that: (i) the toxicity of fluoranthene towards C.caspia alga was obvious; (ii) C. caspia algal growth rate and Chi a content decreased with increasing concentrations of fluoranthene; and (iii) the rate of cell deformation and SOD activity increased with increasing concentrations of fluoranthene. The biodegradation experiment showed that: (i) the rate of physical degradation of fluoranthene was only 5.86%; (ii) the rate of biodegradation of fluoranthene on the 1st and 6th days (i.e. at 24 and 144 h) was approximately 35% and 85%, respectively; and (iii) the biodegradation capability of C. caspia alga towards fluoranthene was high. It is suggested that further investigations on the toxicity of fluoranthene towards algae, as well as on algal biodegradation mechanisms, are of great importance to use C. caspia as a biological treatment species in an organic wastewater treatment system.

  12. Subunit structure of the phycobiliproteins of blue-green algae.

    Science.gov (United States)

    Glazer, A N; Cohen-Bazire, G

    1971-07-01

    The phycobiliproteins of the blue-green algae Synechococcus sp. and Aphanocapsu sp. were characterized with respect to homogeneity, isoelectric point, and subunit composition. Each of the biliproteins consisted of two different noncovalently associated subunits, with molecular weights of about 20,000 and 16,000 for phycocyanin, 17,500 and 15,500 for allophycocyanin, and 22,000 and 20,000 for phycoerythrin. Covalently bound chromophore was associated with each subunit.

  13. Rare species of fungi parasitizing on algae. IV

    Directory of Open Access Journals (Sweden)

    Joanna Z. Kadłubowska

    2014-08-01

    Full Text Available The following parasites of the genera Spirogyra Link, Mougeotia Agardh and Oedogonium Link are desribed: Myzocyutium irregulare, Woroninu glomerata, Harpochytrium tenuissimum, Woronina polycystis, Chytridium acuminatu, Myzocytium irregulare and Chytridumm acuminatum are new to Poland. Also, the first information on Woronina polycystis as a parasite on algae is presented. The figure of cystosori in a cell of Mougeotia mysorensis is the first graphic documentation of this species.

  14. Complete Plastid Genome Sequence of the Brown Alga Undaria pinnatifida.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available In this study, we fully sequenced the circular plastid genome of a brown alga, Undaria pinnatifida. The genome is 130,383 base pairs (bp in size; it contains a large single-copy (LSC, 76,598 bp and a small single-copy region (SSC, 42,977 bp, separated by two inverted repeats (IRa and IRb: 5,404 bp. The genome contains 139 protein-coding, 28 tRNA, and 6 rRNA genes; none of these genes contains introns. Organization and gene contents of the U. pinnatifida plastid genome were similar to those of Saccharina japonica. There is a co-linear relationship between the plastid genome of U. pinnatifida and that of three previously sequenced large brown algal species. Phylogenetic analyses of 43 taxa based on 23 plastid protein-coding genes grouped all plastids into a red or green lineage. In the large brown algae branch, U. pinnatifida and S. japonica formed a sister clade with much closer relationship to Ectocarpus siliculosus than to Fucus vesiculosus. For the first time, the start codon ATT was identified in the plastid genome of large brown algae, in the atpA gene of U. pinnatifida. In addition, we found a gene-length change induced by a 3-bp repetitive DNA in ycf35 and ilvB genes of the U. pinnatifida plastid genome.

  15. Unveiling privacy: advances in microtomography of coralline algae.

    Science.gov (United States)

    Torrano-Silva, Beatriz N; Ferreira, Simone Gomes; Oliveira, Mariana C

    2015-05-01

    Marine calcareous algae are widespread in oceans of the world and known for their calcified cell walls and the generation of rhodolith beds that turn sandy bottoms into a complex structured ecosystem with high biodiversity. Rhodoliths are unattached, branching, crustose benthic marine red algae; they provide habitat for a rich variety of marine invertebrates. The resultant excavation is relevant to sediment production, while is common that the fragments or the whole specimens result in vast fossil deposits formed by rich material that can be "mined" for biological and geological data. Accordingly, microtomography (μCT) may enable a detailed investigation of biological and geological signatures preserved within the rhodolith structure in a non-destructive approach that is especially relevant when analyzing herbaria collections or rare samples. Therefore, we prepared coralline algae samples and submitted them to a range of capabilities provided by the SkyScan1176 micro-CT scanner, including reconstruction, virtual slicing, and pinpointing biological and geological signatures. To this end, polychaetes and mollusk shells, or their excavations, coral nucleation, sediment deposits and conceptacles were all observed. Although a similar technique has been applied previously to samples of living rhodoliths in Brazil, we show, for the first time, its successful application to fossil rhodoliths. We also provide a detailed working protocol and discuss the advantages and limitations of the microtomography within the rhodoliths.

  16. Multi-centennial reconstruction of Aleutian climate from coralline algae

    Science.gov (United States)

    Williams, B.; Halfar, J.; DeLong, K. L.; Smith, E.; Steneck, R.; Lebednik, P.; Jacob, D. E.; Fietzke, J.; Moore, K.

    2015-12-01

    Long-lived encrusting coralline algae yield robust reconstructions of mid-to-high latitude environmental change from their annually-banded high-magnesium calcite skeleton. The magnesium to calcium ratio measured in their skeleton reflects ambient seawater temperature at the time of formation. Thus, reconstructions from these algae are important to understanding the role of natural modes of climate variability versus that of external carbon dioxide in controlling climate in data sparse regions such as the northern North Pacific Ocean/southern Bering Sea. Here, we reconstruct regional seawater temperature from the skeletons of nine algae specimens from two islands in the Aleutian Archipelago. We find that seawater temperature increased ~1.4°C degrees over the past 350 years. The detrended seawater reconstruction correlates with storminess because storms moving across the North Pacific Ocean bring warmer water to the archipelago. Comparison of the algal seawater temperature reconstruction with instrumental and terrestrial proxy reconstructions reveals that atmospheric teleconnections to North America via the North Pacific storm tracks are not robust before the 20th century. This indicates that North Pacific climate processes inferred from the instrumental records should be cautiously extrapolated when describing earlier non-analogous climates or future climate change.

  17. Distribution of periphytic algae in wetlands (Palm swamps, Cerrado, Brazil

    Directory of Open Access Journals (Sweden)

    B Dunck

    Full Text Available The distribution of periphytic algae communities depends on various factors such as type of substrate, level of disturbance, nutrient availability and light. According to the prediction that impacts of anthropogenic activity provide changes in environmental characteristics, making impacted Palm swamps related to environmental changes such as deforestation and higher loads of nutrients via allochthonous, the hypothesis tested was: impacted Palm swamps have higher richness, density, biomass and biovolume of epiphytic algae. We evaluated the distribution and structure of epiphytic algae communities in 23 Palm swamps of Goiás State under different environmental impacts. The community structure attributes here analyzed were composition, richness, density, biomass and biovolume. This study revealed the importance of the environment on the distribution and structuration of algal communities, relating the higher values of richness, biomass and biovolume with impacted environments. Acidic waters and high concentration of silica were important factors in this study. Altogether 200 taxa were identified, and the zygnemaphycea was the group most representative in richness and biovolume, whereas the diatoms, in density of studied epiphyton. Impacted Palm swamps in agricultural area presented two indicator species, Gomphonema lagenula Kützing and Oedogonium sp, both related to mesotrophic to eutrophic conditions for total nitrogen concentrations of these environments.

  18. Distribution of periphytic algae in wetlands (Palm swamps, Cerrado), Brazil.

    Science.gov (United States)

    Dunck, B; Nogueira, I S; Felisberto, S A

    2013-05-01

    The distribution of periphytic algae communities depends on various factors such as type of substrate, level of disturbance, nutrient availability and light. According to the prediction that impacts of anthropogenic activity provide changes in environmental characteristics, making impacted Palm swamps related to environmental changes such as deforestation and higher loads of nutrients via allochthonous, the hypothesis tested was: impacted Palm swamps have higher richness, density, biomass and biovolume of epiphytic algae. We evaluated the distribution and structure of epiphytic algae communities in 23 Palm swamps of Goiás State under different environmental impacts. The community structure attributes here analyzed were composition, richness, density, biomass and biovolume. This study revealed the importance of the environment on the distribution and structuration of algal communities, relating the higher values of richness, biomass and biovolume with impacted environments. Acidic waters and high concentration of silica were important factors in this study. Altogether 200 taxa were identified, and the zygnemaphycea was the group most representative in richness and biovolume, whereas the diatoms, in density of studied epiphyton. Impacted Palm swamps in agricultural area presented two indicator species, Gomphonema lagenula Kützing and Oedogonium sp, both related to mesotrophic to eutrophic conditions for total nitrogen concentrations of these environments.

  19. Microwave-enhanced pyrolysis of natural algae from water blooms.

    Science.gov (United States)

    Zhang, Rui; Li, Linling; Tong, Dongmei; Hu, Changwei

    2016-07-01

    Microwave-enhanced pyrolysis (MEP) of natural algae under different reaction conditions was carried out. The optimal conditions for bio-oil production were the following: algae particle size of 20-5 mesh, microwave power of 600W, and 10% of activated carbon as microwave absorber and catalyst. The maximum liquid yield obtained under N2, 10% H2/Ar, and CO2 atmosphere was 49.1%, 51.7%, and 54.3% respectively. The energy yield of bio-products was 216.7%, 236.9% and 208.7% respectively. More long chain fatty acids were converted into hydrocarbons by hydrodeoxygenation under 10% H2/Ar atmosphere assisted by microwave over activated carbon containing small amounts of metals. Under CO2 atmosphere, carboxylic acids (66.6%) were the main products in bio-oil because the existence of CO2 vastly inhibited the decarboxylation. The MEP of algae was quick and efficient for bio-oil production, which provided a way to not only ameliorate the environment but also obtain fuel or chemicals at the same time.

  20. Extraction, Purification, and NMR Analysis of Terpenes from Brown Algae.

    Science.gov (United States)

    Gaysinski, Marc; Ortalo-Magné, Annick; Thomas, Olivier P; Culioli, Gérald

    2015-01-01

    Algal terpenes constitute a wide and well-documented group of marine natural products with structures differing from their terrestrial plant biosynthetic analogues. Amongst macroalgae, brown seaweeds are considered as one of the richest source of biologically and ecologically relevant terpenoids. These metabolites, mostly encountered in algae of the class Phaeophyceae, are mainly diterpenes and meroditerpenes (metabolites of mixed biogenesis characterized by a toluquinol or a toluquinone nucleus linked to a diterpene moiety).In this chapter, we describe analytical processes commonly employed for the isolation and structural characterization of the main terpenoid constituents obtained from organic extracts of brown algae. The successive steps include (1) extraction of lipidic content from algal samples; (2) purification of terpenes by column chromatography and semi-preparative high-performance liquid chromatography; and (3) structure elucidation of the isolated terpenes by means of 1D and 2D nuclear magnetic resonance (NMR). More precisely, we propose a representative methodology which allows the isolation and structural determination of the monocyclic meroditerpene methoxybifurcarenone (MBFC) from the Mediterranean brown alga Cystoseira amentacea var. stricta. This methodology has a large field of applications and can then be extended to terpenes isolated from other species of the family Sargassaceae.

  1. Towards tradable permits for filamentous green algae pollution.

    Science.gov (United States)

    de Lange, W J; Botha, A M; Oberholster, P J

    2016-09-01

    Water pollution permit systems are challenging to design and implement. Operational systems that has maintained functionality remains few and far between, particularly in developing countries. We present current progress towards developing such a system for nutrient enrichment based water pollution, mainly from commercial agriculture. We applied a production function approach to first estimate the monetary value of the impact of the pollution, which is then used as reference point for establishing a reserve price for pollution permits. The subsequent market making process is explained according to five steps including permit design, terms, conditions and transactional protocol, the monitoring system, piloting and implementation. The monetary value of the impact of pollution was estimated at R1887 per hectare per year, which not only provide a "management budget" for filamentous green algae mitigation strategies in the study area, but also enabled the calculation of a reserve price for filamentous green algae pollution permits, which was estimated between R2.25 and R111 per gram filamentous algae and R8.99 per gram at the preferred state.

  2. Bio sorption of copper ions with biomass of algae and dehydrated waste of olives; Biosorcion de iones cobre con biomasa de algas y orujos deshidratados

    Energy Technology Data Exchange (ETDEWEB)

    Tapia, P.; Santander, M.; Pavez, O.; Valderrama, L.; Guzman, D.; Romero, L.

    2011-07-01

    They were carried out experiments of biosorption batch and in continuous to remove copper from aqueous solutions using as adsorbents green algae and olive residues under virgins conditions and chemically activated. The results of batch bio sorption indicate that the algae present mayor elimination capacities than the waste of olives, with uptakes of copper of the order of 96 % using activated algae with dissolution of Na{sub 2}SO{sub 4} under the optimum conditions. The results of the columns tests show that the virgin algae permits the removal of more copper ions than the activate algae, with removal efficiency of 98 % during the firth 20 min, a breakthrough time of 240 min and a saturation at time of 600 min. In the second cycle the regenerated biomass showed a best performance indicating that they can be used for another bio sorption cycle. (Author) 42 refs.

  3. Arsenic and selenium interactive effect on alga Desmodesmus quadricauda.

    Science.gov (United States)

    Kramárová, Zuzana; Fargašová, Agáta; Molnárová, Marianna; Bujdoš, Marek

    2012-12-01

    Substances known to be toxic in one-component solutions often exhibit unexpected effects when present in mixtures. Only a few efforts have been made to assess the effect of As-Se mixture in algae or plants in general. Due to the lack of information on this topic, the aim of this study was to examine the As-Se interactive effect in the alga species Desmodesmus quadricauda. The initial density of algal cells was 1.9×10(4), cultures were permanently illuminated (70μEm(-2)s(-1)) and As and Se adverse effect was expressed as EC (effective concentration) value. For all experiments three EC (EC(10), EC(20), EC(50)) values for both metalloids were used: for As 26.20, 29.05, 35.38mg L(-1) and for Se 1.93, 3.65, 12.24mg L(-1), respectively. During this study algal biomass growth, lipid peroxidation and protein-bound thiol content parameters were used to assess the As-Se interactions. The reciprocal effect of the elements on their uptake by the alga was also determined. The As-treated algae supplemented with Se exhibited impaired growth indicating a synergistic interaction between the two elements. In samples treated with As-Se mixture, the total algal As content showed marked increase depending on the Se concentration in the mixture. Se uptake was also positively affected by rising As concentrations in the mixture. Consequently, the As-Se-treated algae experienced greater damage to membranes, evidenced by marked elevation of the TBARS (thiobarbituric acid reactive substances) content. The TBARS content increased to a maximum level by 29.05mg L(-1) of As and 3.65mg L(-1) of Se, which was around 70 percent higher than that of the control. The thiol content was very close to that of the control treatment over the entire concentration range and for all As and Se combinations tested. Possible explanation for the synergism observed in D. quadricauda, is that the elevated uptake of As and Se upon their interaction and impaired antioxidant system, has added to the toxicity of the

  4. The Effects of Environmental Factors on the Growth and Competition of Algae

    Institute of Scientific and Technical Information of China (English)

    Jing; WANG; Jiazhang; CHEN; Shunlong; MENG

    2013-01-01

    In order to study the effect of environmental factors on the algae growth and competition,the author summarized overseas and domestic related researches in recent years.Most of the researches are about the influence of single factor on growth of algae.However,there is insufficient investment on the interaction of different factors and the competition between algae growth.This paper briefly introduced the classification of algae and the role they played in ecological system and focused on the influence which included temperature,illumination,nitrogen,phosphorus and pH on the growth and competition of algal.In the end,the author proposed key questions which were still needed to be studied in order to know more about the relationship between environment effects and growth and competition of algae.Therefore,people could better improve the community structure of algae and water ecological environment,and improve water primary productivity.

  5. Enhancement of Taihu blue algae anaerobic digestion efficiency by natural storage.

    Science.gov (United States)

    Miao, Hengfeng; Lu, Minfeng; Zhao, Mingxing; Huang, Zhenxing; Ren, Hongyan; Yan, Qun; Ruan, Wenquan

    2013-12-01

    Taihu blue algae after different storage time from 0 to 60 d were anaerobic fermented to evaluate their digestibility and process stability. Results showed that anaerobic digestion (AD) of blue algae under 15 d natural storage led to the highest CH4 production of 287.6 mL g(-1) VS at inoculum substrate ratio 2.0, demonstrating 36.69% improvement comparing with that from fresh algae. Storage of blue algae led to cell death, microcystins (MCs) release and VS reduction by spontaneous fermentation. However, it also played an important role in removing algal cell wall barrier, pre-hydrolysis and pre-acidification, leading to the improvement in CH4 yield. Closer examination of volatile fatty acids (VFA) variation, VS removal rates and key enzymes change during AD proved short storage time (≤ 15 d) of blue algae had higher efficiencies in biodegradation and methanation. Furthermore, AD presented significant biodegradation potential for MCs released from Taihu blue algae.

  6. Recomendations concerning technical research and development with the purpose to industrially exploit marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Hahn-Haegerdal, B.

    1980-10-01

    This report formulates a proposal for a program for technical research and development concerning use of Marine algae.The report is based on a retrospective literature search, an inquiry to potential algae users and producers in Sweden, visits to and correspondence with scientists and industries in Sweden and abroad. Technical research and development concerning marine algae is needed within the following fields: -Development of new sorts of algae offering resistance to parasite and disease adoptation to cultivation and har- vesting systems,and high-yielding concerning technically interesting components. -Development of suitable cultivation systems for Swedish conditions. -Co-cultivation of fish, mussels, oysters and crustaceans with algae. -Development of harvesting systems. -Methane rotting. -Fatty acid/hydrocarbon production as an alternative to methane rotting. -Physical-chemical properties of marine polysaccharides in relation to their technical properties. -Marine algae as fodder supplement.

  7. Anti-diabetic effects of brown algae derived phlorotannins, marine polyphenols through diverse mechanisms.

    Science.gov (United States)

    Lee, Seung-Hong; Jeon, You-Jin

    2013-04-01

    Marine algae are popular and abundant food ingredients mainly in Asian countries, and also well known for their health beneficial effects due to the presence of biologically active components. The marine algae have been studied for biologically active components and phlorotannins, marine polyphenols are among them. Among marine algae, brown algae have extensively studied for their potential anti-diabetic activities. Majority of the investigations on phlorotannins derived from brown algae have exhibited their various anti-diabetic mechanisms such as α-glucosidase and α-amylase inhibitory effect, glucose uptake effect in skeletal muscle, protein tyrosine phosphatase 1B (PTP 1B) enzyme inhibition, improvement of insulin sensitivity in type 2 diabetic db/db mice, and protective effect against diabetes complication. In this review, we have made an attempt to discuss the various anti-diabetic mechanisms associated with phlorotannins from brown algae that are confined to in vitro and in vivo.

  8. Extraction of alginate biopolymer present in marine alga sargassum filipendula and bioadsorption of metallic ions

    Directory of Open Access Journals (Sweden)

    Sirlei Jaiana Kleinübing

    2013-04-01

    Full Text Available This paper studies the bioadsorption of Pb2+, Cu2+, Cd2+ and Zn2+ ions by marine alga Sargassum filipendula and by the alginate biopolymer extracted from this alga. The objective is to evaluate the importance of this biopolymer in removing different metallic ions by the marine alga S. filipendula. In the equilibrium study, the same affinity order was observed for both bioadsorbents: Pb2+ > Cu2+ > Zn2+ > Cd2+. For Pb2+ and Cu2+ ions when the alginate is isolated and acting as bioadsorbents, adsorption capacities greater than those found for the alga were observed, indicating that it is the main component responsible for the removal of metallic ions. For Zn2+ and Cd2+ ions, greater bioadsorption capacities were observed for the alga, indicating that other functional groups of the alga, such as sulfates and amino, are also important in the bioadsorption of these ions.

  9. Effects of Different Wave-length Illumination on the Reproduction Rate of Paramecium aureli and the Cloning of Potential Photosensitive Genes%不同波长光照对草履虫增殖的影响及其感光蛋白基因克隆的初步探究

    Institute of Scientific and Technical Information of China (English)

    彭铎; 张博钧

    2009-01-01

    Objective To investigate the effect of different wavelengths of light on the reproduction rate of Paramecium aureli. To clone genes encoding possible photosensitive receptor proteins. Methods Reproduction of Paramecium aureli was studied under different illumination conditions: yellow light (wave length 578~592 nm), blue light (wave length 446~464 nm), red light (wave length 620~760 nm), white light, and shaded sunlight. Samples were extracted randomly from each group every hour and the the quantity counted under a microscope. RT-PCR was employed to clone genes encoding possible photosensitive receptor proteins. Results Under light of different wavelengths, paramecium in the yellow light group propagated fastest and showed great discrepancy compared to other groups (P0.05). cDNA fragments of about 500 bp were cloned from RNA templates from the yellow and white groups, cDNA fragments of long wave sensitive opsin-like gene, about 195 bp in length, were cloned from 5 different groups. Conclusions Yellow light promoted reproduction of paramecium while red and blue light suppressed reproduction; yellow and white light may up-regulate the expression of gene encoding rhodopsin-like protein in Paramecium aureli; long wave sensitive opsin-like gene might be expressed in paramecium%目的研究不同波长光照对草履虫增殖的影响,克隆草履虫感光蛋白基因.方法以双小核草履虫 Paramecium aureli为研究对象,分别置于黄色光(578~592 nm)、蓝色光(446~464 nm)、红色光(620~760 nm)、白光和自然光下,每隔1 h随机抽样法显微观察并计数;RT-PCR克隆草履虫感光蛋白基因.结果不同波长光的照射下,与自然光比较,第1天黄光组草履虫增殖显著上升(P0.05);第2天,蓝光组、红光组和白光组草履虫增殖仍受到抑制(P0.05).黄光组和白光组草履虫总RNA作为模板,克隆出大小约500 bp的rhodopsin-like基因cDNA片段, 5个不同光照组均克隆出大小约195 bp的Long wave

  10. Toxic Algae and Early Warning Management in Yellow Sea and Bohai Sea of China

    Institute of Scientific and Technical Information of China (English)

    Song; Lun; Song; Guangjun; Song; Yonggang; Xu; Xiaohong

    2014-01-01

    The research status of toxic algae in Yellow Sea and Bohai Sea are reviewed from the aspects of toxicity characteristics,toxic mechanism and early warning management,and the existing toxic algae and their toxicity in Yellow Sea and Bohai Sea are analyzed in the paper. The early warning level of toxic algae in Yellow Sea and Bohai Sea of China is put forward,and the research direction of shellfish poisoning in future is summarized.

  11. Crustose coralline algae can suppress macroalgal growth and recruitment on Hawaiian coral reefs

    OpenAIRE

    Vermeij, M.J.A.; Dailer, M.L.; Smith, C M

    2011-01-01

    Crustose coralline algae are important components of tropical reef communities because they promote successful settlement by corals and contribute to solidification of the reef framework. We show experimentally that crustose coralline algae are also capable of suppressing the growth and recruitment potential of an abundant Hawaiian reef macroalga, Ulva fasciata. When mixed communities of crustose coralline algae were absent, relative growth rates of U. fasciata increased by 54.6%. When experi...

  12. Red coralline algae assessed as marine pH proxies using 11B MAS NMR

    OpenAIRE

    M. Cusack; Kamenos, N. A.; Rollion-Bard, C.; Tricot, G

    2015-01-01

    Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirt...

  13. Soil algae and mesofauna communities in biotopes of forest rehabilitation in zhovti vody (Dnipropetrovsk region

    Directory of Open Access Journals (Sweden)

    A. V. Posrednikova

    2009-03-01

    Full Text Available The variety of soil algae was studied on areas of revegetation and without it in the Zhovti Vody. The systematic and ecological structure of algal flora and algae dominant species were indicated. We counted 28 species of soil algae on the dumps of uranium mining: Chlorophyta – 11 species (39.5 %, Cyanophyta – 11 (39.5 %, Xanthophyta – 2 (7 %, Bacillariophyta – 2 (7 %, Eustigmatohyta – 2 (7 %.

  14. How-to-Do-It: Diatoms: The Ignored Alga in High School Biology.

    Science.gov (United States)

    Hungerford, James J.

    1988-01-01

    Provides historical background, descriptions, uses and basis for identification of diatoms. Explains collection, dry-mount cleaning, and preparation procedures of the algae. Cites additional resources. (RT)

  15. Multispectral sorter for rapid, nondestructive optical bioprospecting for algae biofuels

    Science.gov (United States)

    Davis, Ryan W.; Wu, Hauwen; Singh, Seema

    2014-03-01

    Microalgal biotechnology is a nascent yet burgeoning field for developing the next generation of sustainable feeds, fuels, and specialty chemicals. Among the issues facing the algae bioproducts industry, the lack of efficient means of cultivar screening and phenotype selection represents a critical hurdle for rapid development and diversification. To address this challenge, we have developed a multi-modal and label-free optical tool which simultaneously assesses the photosynthetic productivity and biochemical composition of single microalgal cells, and provides a means for actively sorting attractive specimen (bioprospecting) based on the spectral readout. The device integrates laser-trapping micro-Raman spectroscopy and pulse amplitude modulated (PAM) fluorometry of microalgal cells in a flow cell. Specifically, the instrument employs a dual-purpose epi-configured IR laser for single-cell trapping and Raman spectroscopy, and a high-intensity VISNIR trans-illumination LED bank for detection of variable photosystem II (PSII) fluorescence. Micro-Raman scatter of single algae cells revealed vibrational modes corresponding to the speciation and total lipid content, as well as other major biochemical pools, including total protein, carbohydrates, and carotenoids. PSII fluorescence dynamics provide a quantitative estimate of maximum photosynthetic efficiency and regulated and non-regulated non-photochemical quenching processes. The combined spectroscopic readouts provide a set of metrics for subsequent optical sorting of the cells by the laser trap for desirable biomass properties, e.g. the combination of high lipid productivity and high photosynthetic yield. Thus the device provides means for rapid evaluation and sorting of algae cultures and environmental samples for biofuels development.

  16. The ecology of viruses that infect eukaryotic algae.

    Science.gov (United States)

    Short, Steven M

    2012-09-01

    Because viruses of eukaryotic algae are incredibly diverse, sweeping generalizations about their ecology are rare. These obligate parasites infect a range of algae and their diversity can be illustrated by considering that isolates range from small particles with ssRNA genomes to much larger particles with 560 kb dsDNA genomes. Molecular research has also provided clues about the extent of their diversity especially considering that genetic signatures of algal viruses in the environment rarely match cultivated viruses. One general concept in algal virus ecology that has emerged is that algal viruses are very host specific and most infect only certain strains of their hosts; with the exception of viruses of brown algae, evidence for interspecies infectivity is lacking. Although some host-virus systems behave with boom-bust oscillations, complex patterns of intraspecies infectivity can lead to host-virus coexistence obfuscating the role of viruses in host population dynamics. Within the framework of population dynamics, host density dependence is an important phenomenon that influences virus abundances in nature. Variable burst sizes of different viruses also influence their abundances and permit speculations about different life strategies, but as exceptions are common in algal virus ecology, life strategy generalizations may not be broadly applicable. Gaps in knowledge of virus seasonality and persistence are beginning to close and investigations of environmental reservoirs and virus resilience may answer questions about virus inter-annual recurrences. Studies of algal mortality have shown that viruses are often important agents of mortality reinforcing notions about their ecological relevance, while observations of the surprising ways viruses interact with their hosts highlight the immaturity of our understanding. Considering that just two decades ago algal viruses were hardly acknowledged, recent progress affords the optimistic perspective that future studies

  17. Reclamation with blue-green algae: changes in nucleic acids, protein and nitrogen content of algae exposed to solid waste of a chlor-alkali factory

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, B.B.; Nanda, D.R.; Misra, B.N.

    1985-01-01

    During an attempt at the possible reclamation of solid waste from a chlor-alkali factory by blue-green algae, the effects of the solid waste on biochemical variables were studied. DNA, RNA, protein, and algal nitrogen content of the algal material showed a significant decrease with increase in time and also solid waste concentration. An increase in RNA/DNA ratio and a decrease in protein/RNA ratio were also observed. Algae accumulated appreciable amounts of mercury from the waste, showing dependence on both concentration and time. Significant correlations were obtained between mercury uptake and concentrations of the waste and between different combinations of algae and mercury uptake.

  18. Bioactivities from Marine Algae of the Genus Gracilaria

    Science.gov (United States)

    de Almeida, Cynthia Layse F.; Falcão, Heloina de S.; Lima, Gedson R. de M.; Montenegro, Camila de A.; Lira, Narlize S.; de Athayde-Filho, Petrônio F.; Rodrigues, Luis C.; de Souza, Maria de Fátima V.; Barbosa-Filho, José M.; Batista, Leônia M.

    2011-01-01

    Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted. PMID:21845096

  19. Bioactivities from Marine Algae of the Genus Gracilaria

    Directory of Open Access Journals (Sweden)

    José M. Barbosa-Filho

    2011-07-01

    Full Text Available Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS, inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.

  20. Measuring Oscillatory Velocity Fields Due to Swimming Algae

    CERN Document Server

    Guasto, Jeffrey S; Gollub, J P

    2010-01-01

    In this fluid dynamics video, we present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than four times what steady swimming would require.

  1. The auxin concentration in sixteen Chinese marine algae

    Science.gov (United States)

    Han, Lijun

    2006-09-01

    The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleoptile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1 46.9 ng/g Fw (fresh weight) with FS and 5.3 110.2 ng/g Fw with WCB. The results by the two methods were in the orders of 10-3 103 ng/g Fw reported previously from multiple references.

  2. Multi-scale Characterization of Improved Algae Strains

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Taraka T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-04-01

    This report relays the important role biofuels such as algae could have in the energy market. The report cites that problem of crude oil becoming less abundant while the demand for energy continues to rise. There are many benefits of producing energy with biofuels such as fewer carbon emissions as well as less land area to produce the same amount of energy compared to other sources of renewable fuels. One challenge that faces biofuels right now is the cost to produce it is high.

  3. Study on sterols from brown algae (Sargassum muticum)

    Institute of Scientific and Technical Information of China (English)

    WANG Peirong; XU Guanjun; BIAN Lizeng; ZHANG Shuichang; SONG Fuqing

    2006-01-01

    Various △5-3β-sterenols, whose carbon numbers range from C19-C23 to C26-C30and some compounds have many stereomers maximal up to six,have been detected out from the extract of brown algae (Sargassum muticum), which means that steranes with lower carbon numbers are likely different in the origin, and some corresponding sterol stereoisomers may have already existed in their precursor organisms. This provides some experimental evidence for supplementing and amending the traditional interpretation of the sterol stereoisomer transformation during the deposition and diagenesis of organic matter.

  4. Microsatellite Primers in the Lichen Symbiotic Alga Trebouxia decolorans (Trebouxiophyceae

    Directory of Open Access Journals (Sweden)

    Francesco Dal Grande

    2013-03-01

    Full Text Available Premise of the study: Polymorphic microsatellite markers were developed for the symbiotic green alga Trebouxia decolorans to study fine-scale population structure and clonal diversity. Methods and Results: Using Illumina pyrosequencing, 20 microsatellite primer sets were developed for T. decolorans. The primer sets were tested on 43 individuals sampled from four subpopulations in Germany. The primers amplified di-, tri-, and tetranucleotide repeats with three to 15 alleles per locus, and the unbiased haploid diversity per locus ranged from 0.636 to 0.821. Conclusions: The identified microsatellite markers will be useful to study the genetic diversity, dispersal, and reproductive mode of this common lichen photobiont.

  5. [Epiphytic algae from Bajo Pepito, Isla Mujeres, Quintana Roo, Mexico].

    Science.gov (United States)

    Quan-Young, L I; Díaz-Martín, M A; Espinoza-Avalos, J

    2006-06-01

    A total of 96 epiphytic algae species were identified from Bajo Pepito, Quintana Roo, México. 60.4% (58) belonged to the Rhodophyta, 19.79% (19) to the Phaeophyta, 16.6% (16) to the Chlorophyta and 3.1% (3) to the Cyanophyta; 49 species (50.5%) were found only in one month, while Heterosiphonia crispella was found in all of the sampled months. That species provided the largest contribution to the biomass of epiphytes. During January we registered the greater biommass and richness of epiphytes species, coincidently with high values of host species cover and rainfall.

  6. The auxin concentration in sixteen Chinese marine algae

    Institute of Scientific and Technical Information of China (English)

    HAN Lijun

    2006-01-01

    The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleoptile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1-46.9 ng/g Fw (fresh weight) with FS and 5.3-110.2 ng/g Fw with WCB. The results by the two methods were in the orders of 10-3-103 ng/g Fw reported previously from multiple references.

  7. Global analysis of Chlorella variabilis NC64A mRNA profiles during the early phase of Paramecium bursaria chlorella virus-1 infection.

    Directory of Open Access Journals (Sweden)

    Janet M Rowe

    Full Text Available The PBCV-1/Chlorella variabilis NC64A system is a model for studies on interactions between viruses and algae. Here we present the first global analyses of algal host transcripts during the early stages of infection, prior to virus replication. During the course of the experiment stretching over 1 hour, about a third of the host genes displayed significant changes in normalized mRNA abundance that either increased or decreased compared to uninfected levels. The population of genes with significant transcriptional changes gradually increased until stabilizing at 40 minutes post infection. Functional categories including cytoplasmic ribosomal proteins, jasmonic acid biosynthesis and anaphase promoting complex/cyclosomes had a significant excess in upregulated genes, whereas spliceosomal snRNP complexes and the shikimate pathway had significantly more down-regulated genes, suggesting that these pathways were activated or shut-down in response to the virus infection. Lastly, we examined the expression of C. varibilis RNA polymerase subunits, as PBCV-1 transcription depends on host RNA polymerases. Two subunits were up-regulated, RPB10 and RPC34, suggesting that they may function to support virus transcription. These results highlight genes and pathways, as well as overall trends, for further refinement of our understanding of the changes that take place during the early stages of viral infection.

  8. 不同培养液对大草履虫生长的影响%Effect of different mediums on the Growth of label subsubsec:effect Paramecium caudatum

    Institute of Scientific and Technical Information of China (English)

    李淑梅; 李季平

    2008-01-01

    大草履虫(Paramecium caudatum)是动物学教学和实验生物学的重要材料,不同的培养液对草履虫生长有影响.本试验选取狗尾草、玉米芯、小麦粒,玉米粒、白糖等较为常见材料,制成不同浓度培养液来培养大草履虫.以观察它们对大草履虫种群生长和个体形态的影响,以期找到既分布广泛又理想的培养材料.结果表明:玉米粒和玉米芯是理想的培养大草履虫的材料,其中1%玉米粒培养液的培养效果最好.

  9. Effects of pesticides on Paramecium caudatum individual's growth and population dynamics%农药胁迫对草履虫个体生长和种群动态的影响

    Institute of Scientific and Technical Information of China (English)

    谷艳芳; 柳爱莲; 丁圣彦; 肖保林; 彭玲; 苏江峰

    2007-01-01

    采用连续培养法探讨了草履虫(Paramecium caudatum)在甲胺磷、2,4-D丁酯和甲氰菊酯3种农药胁迫条件下的个体生长和种群动态,并利用Logistic种群增长模型对种群的增长曲线进行了分析.结果表明:甲胺磷和甲氰菊酯农药胁迫能改变草履虫细胞的大小和形态;不同农药不同浓度处理下,草履虫密度增长曲线均具有"S"型生长特点;农药胁迫下草履虫密度增长曲线符合Logistic模型(R2>0.8),3种农药胁迫下K值明显降低;甲胺磷和甲氰菊酯农药胁迫下种群最大增长率低于2,4-D丁酯胁迫和对照.

  10. A Study on the Isoenzymes of Paramecium bursaria Cultured   in Light and Dark%光培养和暗培养绿草履虫中同工酶的比较研究

    Institute of Scientific and Technical Information of China (English)

    张许枚; 田沁; 顾福康

    2001-01-01

    PAGE was used to analyze and compare the variation of composition and content of four isoenzymes , esterase, acid phosphatase, malate dehydrogenase (MDH) and lactate dehydrogenase(LDH), of Paramecium bursaria which cultured in light and dark . Except LDH was not checked up band, the electrophoresis results of other three isoenzymes indicated that the isoenzymes of dark cultivated P. bursaria had more bands and higher content .From these results it can be concluded that the symbiotic Chlorella probably effect the gene expression of the host cell.%作者应用聚丙烯酰胺凝胶电泳技术分析比较了光培养绿草履虫和暗培养绿草履虫中酯酶、酸性磷酸酶、苹果酸脱氢酶和乳酸脱氢酶四种同工酶的组分及含量的变化。除了对乳酸脱氢酶未检出酶蛋白条带外,其它三种酶的电泳图谱都显示暗培养草履虫的同工酶组成条带多、含量高。作者由所得结果推测小球藻共生体可能改变了宿主细胞基因的表达。

  11. Monoclonal antibodies directed to fucoidan preparations from brown algae.

    Science.gov (United States)

    Torode, Thomas A; Marcus, Susan E; Jam, Murielle; Tonon, Thierry; Blackburn, Richard S; Hervé, Cécile; Knox, J Paul

    2015-01-01

    Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance.

  12. Sulfur utilization of corals is enhanced by endosymbiotic algae

    Directory of Open Access Journals (Sweden)

    Ikuko Yuyama

    2016-09-01

    Full Text Available Sulfur-containing compounds are important components of all organisms, but few studies have explored sulfate utilization in corals. Our previous study found that the expression of a sulfur transporter (SLC26A11 was upregulated in the presence of Symbiodinium cells in juveniles of the reef-building coral Acropora tenuis. In this study, we performed autoradiography using 35S-labeled sulfate ions (35SO4 2− to examine the localization and amount of incorporated radioactive sulfate in the coral tissues and symbiotic algae. Incorporated 35SO4 2− was detected in symbiotic algal cells, nematocysts, ectodermal cells and calicoblast cells. The combined results of 35S autoradiography and Alcian Blue staining showed that incorporated 35S accumulated as sulfated glycosaminoglycans (GAGs in the ectodermal cell layer. We also compared the relative incorporation of 35SO4 2− into coral tissues and endosymbiotic algae, and their chemical fractions in dark versus light (photosynthetic conditions. The amount of sulfur compounds, such as GAGs and lipids, generated from 35SO4 2− was higher under photosynthetic conditions. Together with the upregulation of sulfate transporters by symbiosis, our results suggest that photosynthesis of algal endosymbionts contributes to the synthesis and utilization of sulfur compounds in corals.

  13. Solar-driven hydrogen production in green algae.

    Science.gov (United States)

    Burgess, Steven J; Tamburic, Bojan; Zemichael, Fessehaye; Hellgardt, Klaus; Nixon, Peter J

    2011-01-01

    The twin problems of energy security and global warming make hydrogen an attractive alternative to traditional fossil fuels with its combustion resulting only in the release of water vapor. Biological hydrogen production represents a renewable source of the gas and can be performed by a diverse range of microorganisms from strict anaerobic bacteria to eukaryotic green algae. Compared to conventional methods for generating H(2), biological systems can operate at ambient temperatures and pressures without the need for rare metals and could potentially be coupled to a variety of biotechnological processes ranging from desalination and waste water treatment to pharmaceutical production. Photobiological hydrogen production by microalgae is particularly attractive as the main inputs for the process (water and solar energy) are plentiful. This chapter focuses on recent developments in solar-driven H(2) production in green algae with emphasis on the model organism Chlamydomonas reinhardtii. We review the current methods used to achieve sustained H(2) evolution and discuss possible approaches to improve H(2) yields, including the optimization of culturing conditions, reducing light-harvesting antennae and targeting auxiliary electron transport and fermentative pathways that compete with the hydrogenase for reductant. Finally, industrial scale-up is discussed in the context of photobioreactor design and the future prospects of the field are considered within the broader context of a biorefinery concept.

  14. Ecotoxicological effects of carbon nanomaterials on algae, fungi and plants.

    Science.gov (United States)

    Basiuk, Elena V; Ochoa-Olmos, Omar E; De la Mora-Estrada, León F

    2011-04-01

    The ecotoxicological effects of carbon nanomateriales (CNMs), namely fullerenes and carbon nanotubes, on algae, fungi and plants are analyzed. In different toxicity tests, both direct and indirect effects were found. The direct effects are determined by nanomaterial chemical composition and surface reactivity, which might catalyze redox reactions in contact with organic molecules and affect respiratory processes. Some indirect effects of carbon nanoparticles (CNPs) are physical restraints or release of toxic ions. Accumulation of CNPs in photosynthetic organs provokes obstruction in stomata, foliar heating and alteration in physiological processes. The phytotoxicity studies of CNMs should be focused on determining phytotoxicity mechanisms, size distribution of CNPs in solution, uptake and translocation of nanoparticles by plants, on characterization of their physical and chemical properties in rhizosphere and on root surfaces. More studies on plants and algae, as a part of food chain, are needed to understand profoundly the toxicity and health risks of CNMs as ecotoxicological stressors. Correct and detailed physical and chemical characterization of CNMs is very important to establish the exposure conditions matching the realistic ones. Ecotoxicity experiments should include examinations of both short and long-term effects. One must take into account that real carbon nanomaterials are complex mixtures of carbon forms and metal residues of variable chemistry and particle size, and the toxicity reported may reflect these byproducts/residues/impurities rather than the primary material structure. One more recommendation is not only to focus on the inherent toxicity of nanoparticles, but also consider their possible interactions with existing environmental contaminants.

  15. ALGAE PROLIFERATION ON SUBSTRATES IMMERSED IN BIOLOGICALLY TREATED SEWAGE

    Directory of Open Access Journals (Sweden)

    Tomasz Garbowski

    2017-01-01

    Full Text Available Due fast biomass production, high affinity for N and P and possibilities to CO2 sequestration microalgae are currently in the spotlight, especially in renewable energy technologies sector. The majority of studies focus their attention on microalgae cultivation with respect to biomass production. Fuel produced from algal biomass can contribute to reducing consumption of conventional fossil fuels and be a remedy for a rising energy crisis and global warming induced by air pollution. Some authors opt for possibilities of using sewage as a nutrient medium in algae cultivation. Other scientists go one step further and present concepts to introduce microalgal systems as an integral part of wastewater treatment plants. High costs of different microalgal harvesting methods caused introduction of the idea of algae immobilization in a form of periphyton on artificial substrates. In the present study the attention has focused on possibilities of using waste materials as substrates to proliferation of periphyton in biologically treated sewage that contained certain amounts of nitrogen and phosphorus.

  16. SULFOGLYCOLIPID FROM THE MARINE BROWN ALGA SARGASSUM HEMIPHYLLUM

    Institute of Scientific and Technical Information of China (English)

    ZHENG CUI; YU-SHAN LI; HONG-BING LIU; DAN YUAN; BAO-REN LU

    2001-01-01

    One kinds of glycolipid (SBI) have been isolated from the marine brown alga Sargassum hemiphyllum (Turn.) Ag. The structures of SBI have been determined as the sodium salt of 1-0-acyl-3-0-(6′-sulfo-c-D-quinovopyrannosyl) glycerol (acyl: tetradecanoyl, pentadecanoyl, 11-hexadecenoyl, hexadecanoyl, 10,13-octadecadienoyl, 9-octade cenoyl, 15-metylheptadecanoyl and 11-eicosenoyl 17:1.5:19:153:1: 19:1:2) on the basis of chemical and spectral evidence and GC-MS analysis, respectively. Four constituents of the SBI were new compounds [the sodium salt of 1-0-(ll″-hexadecenoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol, the sodium salt of 1-0-(10",13"-octadecadienoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl) glycerol,and the sodium salt of 1-0-(15"-metylhexadecenoyl)-3-0-(6′-sulfo-c-D-quinovopyrannosyl)glycerol, and the sodium salt of 1-0-(ll"-eicosenoyl)-3-0-(6′-sulfo-α-D-quinovopyrannosyl)glycerol]. All compounds were isolated from marine brown alga for the first time.

  17. [Food value of the spiruline algae to man].

    Science.gov (United States)

    Sautier, C; Tremolieres, J

    1975-01-01

    The acceptability of various culinary products based on the algae spirulina was tested by questionaire: formulas rich in proteins, soups, omelets, desserts. Spirulina are little appreciated in France due to offensive color, smell and taste. Tomato and chocolate are the most acceptable flavors. Lyophilisation is preferable to atomisation, and discoloration using alcohol is preferable to the acetone method. The hydrolysate obtained, having neither the smell nor the taste of algae, is excellent. Nitrogen, sodium and potassium balances were recorded in 5 undernourished subjects fed via a gastric tube. The spirulina provided respectively 15 p. 100 (1 subject), 30 p. 100 (2 subjects), and 50 p. 100 (2 subjects) of the protein ration. There were no intestinal problems. The spirulina did not modify the investigated balances. However, faecal nitrogen increased to 2.08 g (compared to control period values, 1.33 g and 1.51 g). The various coefficients: digestibility, nitrogen retention and protein utilization did not vary. In man as in animals, nitrogen retention is satisfactory, but digestibility is diminished. Uric acid did not vary in the urine, but serum values increased slightly. Ingestion of spirulina in small doses even over a long period should be tolerable in the normal subject.

  18. Monoclonal antibodies directed to fucoidan preparations from brown algae.

    Directory of Open Access Journals (Sweden)

    Thomas A Torode

    Full Text Available Cell walls of the brown algae contain a diverse range of polysaccharides with useful bioactivities. The precise structures of the sulfated fucan/fucoidan group of polysaccharides and their roles in generating cell wall architectures and cell properties are not known in detail. Four rat monoclonal antibodies, BAM1 to BAM4, directed to sulfated fucan preparations, have been generated and used to dissect the heterogeneity of brown algal cell wall polysaccharides. BAM1 and BAM4, respectively, bind to a non-sulfated epitope and a sulfated epitope present in the sulfated fucan preparations. BAM2 and BAM3 identified additional distinct epitopes present in the fucoidan preparations. All four epitopes, not yet fully characterised, occur widely within the major brown algal taxonomic groups and show divergent distribution patterns in tissues. The analysis of cell wall extractions and fluorescence imaging reveal differences in the occurrence of the BAM1 to BAM4 epitopes in various tissues of Fucus vesiculosus. In Ectocarpus subulatus, a species closely related to the brown algal model Ectocarpus siliculosus, the BAM4 sulfated epitope was modulated in relation to salinity levels. This new set of monoclonal antibodies will be useful for the dissection of the highly complex and yet poorly resolved sulfated polysaccharides in the brown algae in relation to their ecological and economic significance.

  19. Indefatigable: an erect coralline alga is highly resistant to fatigue.

    Science.gov (United States)

    Denny, Mark; Mach, Katharine; Tepler, Sarah; Martone, Patrick

    2013-10-15

    Intertidal organisms are subjected to intense hydrodynamic forces as waves break on the shore. These repeated insults can cause a plant or animal's structural materials to fatigue and fail, even though no single force would be sufficient to break the organism. Indeed, the survivorship and maximum size of at least one species of seaweed is set by the accumulated effects of small forces rather than the catastrophic imposition of a single lethal force. One might suppose that fatigue would be especially potent in articulated coralline algae, in which the strain of the entire structure is concentrated in localized joints, the genicula. However, previous studies of joint morphology suggest an alternative hypothesis. Each geniculum is composed of a single tier of cells, which are attached at their ends to the calcified segments of the plant (the intergenicula) but have minimal connection to each other along their lengths. This lack of neighborly attachment potentially allows the weak interfaces between cells to act as 'crack stoppers', inhibiting the growth of fatigue cracks. We tested this possibility by repeatedly loading fronds of Calliarthron cheilosporioides, a coralline alga common on wave-washed shores in California. When repeatedly loaded to 50-80% of its breaking strength, C. cheilosporioides commonly survives more than a million stress cycles, with a record of 51 million. We show how this extraordinary fatigue resistance interacts with the distribution of wave-induced water velocities to set the limits to size in this species.

  20. Chemical mediation of coral larval settlement by crustose coralline algae.

    Science.gov (United States)

    Tebben, J; Motti, C A; Siboni, Nahshon; Tapiolas, D M; Negri, A P; Schupp, P J; Kitamura, Makoto; Hatta, Masayuki; Steinberg, P D; Harder, T

    2015-06-04

    The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds--glycoglycerolipids and polysaccharides--as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples.

  1. Halophytes, Algae, and Bacteria Food and Fuel Feedstocks

    Science.gov (United States)

    Hendricks, R. C.; Bushnell, D. M.

    2009-01-01

    The constant, increasing demand for energy, freshwater, and food stresses our ability to meet these demands within reasonable cost and impact on climate while sustaining quality of life. This environmental Triangle of Conflicts between energy, food, and water--while provoked by anthropogenic monetary and power struggles--can be resolved through an anthropogenic paradigm shift in how we produce and use energy, water, and food. With world population (6.6 billion) projected to increase 40 percent in 40 to 60 yr, proper development of saline agriculture and aquaculture is required, as 43 percent of the Earth's landmass is arid or semi-arid and 97 percent of the Earth's water is seawater. In light of this, we seek fuel alternatives in plants that thrive in brackish and saltwater with the ability to survive in arid lands. The development and application of these plants (halophytes) become the primary focus. Herein we introduce some not-so-familiar halophytes and present a few of their benefits, cite a few research projects (including some on the alternatives algae and bacteria), and then set theoretical limits on biomass production followed by projections in terms of world energy demands. Based on diverse arid lands with a total size equivalent to the Sahara Desert (8.6(exp 8) ha, or 2.1(exp 9) acres), these projections show that halophyte agriculture and algae systems can provide for the projected world energy demand.

  2. Biodiesel Fuel Production from Algae as Renewable Energy

    Directory of Open Access Journals (Sweden)

    A. B.M. Sharif Hossain

    2008-01-01

    Full Text Available Biodiesel is biodegradable, less CO2 and NOx emissions. Continuous use of petroleum sourced fuels is now widely recognized as unsustainable because of depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Renewable, carbon neutral, transport fuels are necessary for environmental and economic sustainability. Algae have emerged as one of the most promising sources for biodiesel production. It can be inferred that algae grown in CO2-enriched air can be converted to oily substances. Such an approach can contribute to solve major problems of air pollution resulting from CO2 evolution and future crisis due to a shortage of energy sources. This study was undertaken to know the proper transesterification, amount of biodiesel production (ester and physical properties of biodiesel. In this study we used common species Oedogonium and Spirogyra to compare the amount of biodiesel production. Algal oil and biodiesel (ester production was higher in Oedogonium than Spirogyra sp. However, biomass (after oil extraction was higher in Spirogyra than Oedogonium sp. Sediments (glycerine, water and pigments was higher in Spirogyra than Oedogonium sp. There was no difference of pH between Spirogyra and Oedogonium sp. These results indicate that biodiesel can be produced from both species and Oedogonium is better source than Spirogyra sp.

  3. Photosynthetic Hydrogen and Oxygen Production by Green Algae

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.

    1999-08-22

    Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are: (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of hotosynthesis throughout the entire range of terrestrial solar irradiance-including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transpor;t and (3) constructing real-world bioreactors, including the generation of hydrogen and oxygen against workable back pressures of the photoproduced gases.

  4. Short-term uptake of heavy metals by periphyton algae

    Energy Technology Data Exchange (ETDEWEB)

    Vymazal, J.

    1984-12-31

    The utilization of periphyton for the removal of heavy metals from enriched small streams has been examined. By means of short-term batch laboratory experiments the courses of metal uptake have been studied. For uptake study naturally growing periphyton community and periphytic filamentous algae Cladophora glomerata and Oedogonium rivulare have been used. Uptakes of nine heavy metals (Pb, Cd, Cu, Co, Cr, Ni, Zn, Fe and Mn) have been determined during four hours exposure. In addition the influence of humic substances on heavy metals uptake has been determined. Uptake of all metals increased during four hours exposure but not in the same way. Some metals were removed continuously (Ni, Cr, Fe and Mn), other metals were removed more rapidly during the first hour or first two hours of exposure and then only slight removal continued (Cu, Pb, Cd, Co). Uptake of Zn was rather unambiguous. Results of these experiments suggest that the course of uptake for individual metals could be similar for most periphyton algae. It was established that humic substances significantly reduce heavy metals uptake. The highest decrease of uptake was observed in Cu, Cr, Co and Cd. The results of model experiments are being tested in a pilot scale with respect to the demands of engineering practice. (J.R.)

  5. Predicting toxicity of aromatic ternary mixtures to algae

    Institute of Scientific and Technical Information of China (English)

    LU GuangHua; WANG Chao; WANG PeiFang; YANG ChengZhi

    2009-01-01

    Aquatic ecosystems are often polluted with more than one type of contaminant, and information on the combined toxic effects of mixed pollutants on aquatic organisms is scarce at present. Acute toxicity of aromatic compounds and their ternary mixtures to the alga (Scenedesmus obliquus) was determined by the algae growth inhibition test. The median effective concentration (EC_(50)) value for a single aromatic compound and EC_(50mix) values for mixtures were obtained, the logarithm of n-octanol/water partition coefficient (logP_(mix)) and the frontier orbital energy gap (△E_(mix) for mixtures were calculated. Based on the quantitative structure-activity relationship model for single chemical toxicity log(1/EC_(50)) =0.426logP-1.150△E+12.61 (n=15, R~2=0.917 and Q~2=0.878), the following two-descriptor model was developed for the ternary mixture toxicity of aromatic compounds: log(1/EC_(50mix))=O.68210gP_(mix)-O.367△E_(mix)+ 4.971 (n=44, R~2-0.869 and Q~2=0.843). This model can be used to predict the combined toxicity of mixtures containing toxicants with different mechanisms of action.

  6. Identifying vital effects in Halimeda algae with Ca isotopes

    Directory of Open Access Journals (Sweden)

    C. L. Blättler

    2014-12-01

    Full Text Available Geochemical records of biogenic carbonates provide some of the most valuable records of the geological past, but are often difficult to interpret without a mechanistic understanding of growth processes. In this experimental study, Halimeda algae are used as a test organism to untangle some of the specific factors that influence their skeletal composition, in particular their Ca-isotope composition. Algae were stimulated to precipitate both calcite and aragonite by growth in artificial Cretaceous seawater, resulting in experimental samples with somewhat malformed skeletons. The Ca-isotope fractionation of the algal calcite (−0.6‰ appears to be much smaller than that for the algal aragonite (−1.4‰, similar to the behaviour observed in inorganic precipitates. However, the carbonate from Halimeda has higher Ca-isotope ratios than inorganic forms by approximately 0.25‰, likely because of Rayleigh distillation within the algal intercellular space. In identifying specific vital effects and the magnitude of their influence on Ca-isotope ratios, this study suggests that mineralogy has a first-order control on the marine Ca-isotope cycle.

  7. Photosynthetic hydrogen and oxygen production by green algae

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, E.; Lee, J.W.

    1997-12-31

    An overview of photosynthetic hydrogen and oxygen production by green algae in the context of its potential as a renewable chemical feed stock and energy carrier is presented. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance--including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) the minimum number of light reactions that are required to split water to elemental hydrogen and oxygen. Each of these research topics is being actively addressed by the photobiological hydrogen research community.

  8. Algas: da economia nos ambientes aquáticos à bioremediação e à química analítica Algae: from aquatic environment economy to bioremediation and analytical chemistry

    Directory of Open Access Journals (Sweden)

    Eliane Cristina Vidotti

    2004-02-01

    Full Text Available Algae constitute a large group of many different organisms, essentially aquatic and able to live in all systems giving them sufficient light and humidity. Some algae species have been used in the evaluation or in the bioremediation of aquatic systems. More recently algae have been suggested as interesting tools in the field of analytical chemistry. In this work the most important aspects related to the different uses of algae are presented with a brief discussion.

  9. Salinity dependent hydrogen isotope fractionation in alkenones produced by coastal and open ocean haptophyte algae

    NARCIS (Netherlands)

    M'boule, D.; Chivall, D.; Sinke-Schoen, D.; Sinninghe Damsté, J.S.; Schouten, S.; van der Meer, M.T.J.

    2014-01-01

    The hydrogen isotope fractionation in alkenones produced by haptophyte algae is a promising new proxy for paleosalinity reconstructions. To constrain and further develop this proxy the coastal haptophyte Isochrysis galbana and the open ocean haptophyte alga Emiliania huxleyi were cultured at differe

  10. Closed and continuous algae cultivation system for food production and gas exchange in CELSS

    Science.gov (United States)

    Oguchi, Mitsuo; Otsubo, Koji; Nitta, Keiji; Shimada, Atsuhiro; Fujii, Shigeo; Koyano, Takashi; Miki, Keizaburo

    In CELSS (Controlled Ecological Life Support System), utilization of photosynthetic algae is an effective means for obtaining food and oxygen at the same time. We have chosen Spirulina, a blue-green alga, and have studied possibilities of algae utilization. We have developed an advanced algae cultivation system, which is able to produce algae continuously in a closed condition. Major features of the new system are as follows. o (1)In order to maintain homogeneous culture conditions, the cultivator was designed so as to cause a swirl on medium circulation. (2)Oxygen gas separation and carbon dioxide supply are conducted by a newly designed membrane module. (3)Algae mass and medium are separated by a specially designed harvester. (4)Cultivation conditions, such as pH, temperature, algae growth rate, light intensity and quanlity of generated oxygen gas are controlled by a computer system and the data are automatically recorded. This equipment is a primary model for ground experiments in order to obtain some design data for space use. A feasibility of algae cultivation in a closed condition is discussed on the basis of data obtained by use of this new system.

  11. Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe

    NARCIS (Netherlands)

    Blaas, H.; Kroeze, C.

    2014-01-01

    Biodiesel is increasingly considered as an alternative for fossil diesel. Biodiesel can be produced from rapeseed, palm, sunflower, soybean and algae. In this study, the consequences of large-scale production of biodiesel from micro-algae for eutrophication in four large European seas are analysed.

  12. The current potential of algae biofuels in the United Arab Emirates

    Science.gov (United States)

    In spite of future uncertainties about industrial algae biofuel production, the UAE is planning to become "a world leader in biofuels from the algae industry by 2020;" thus joining major countries which have already started producing renewable energy and biofuels (biodiesel and bioethanol) from rene...

  13. Microbial to reef scale interactions between the reef-building coral Montastraea annularis and benthic algae.

    Science.gov (United States)

    Barott, Katie L; Rodriguez-Mueller, Beltran; Youle, Merry; Marhaver, Kristen L; Vermeij, Mark J A; Smith, Jennifer E; Rohwer, Forest L

    2012-04-22

    Competition between reef-building corals and benthic algae is of key importance for reef dynamics. These interactions occur on many spatial scales, ranging from chemical to regional. Using microprobes, 16S rDNA pyrosequencing and underwater surveys, we examined the interactions between the reef-building coral Montastraea annularis and four types of benthic algae. The macroalgae Dictyota bartayresiana and Halimeda opuntia, as well as a mixed consortium of turf algae, caused hypoxia on the adjacent coral tissue. Turf algae were also associated with major shifts in the bacterial communities at the interaction zones, including more pathogens and virulence genes. In contrast to turf algae, interactions with crustose coralline algae (CCA) and M. annularis did not appear to be antagonistic at any scale. These zones were not hypoxic, the microbes were not pathogen-like and the abundance of coral-CCA interactions was positively correlated with per cent coral cover. We propose a model in which fleshy algae (i.e. some species of turf and fleshy macroalgae) alter benthic competition dynamics by stimulating bacterial respiration and promoting invasion of virulent bacteria on corals. This gives fleshy algae a competitive advantage over corals when human activities, such as overfishing and eutrophication, remove controls on algal abundance. Together, these results demonstrate the intricate connections and mechanisms that structure coral reefs.

  14. The blue water footprint and land use of biofuels from algae

    NARCIS (Netherlands)

    Gerbens-Leenes, P. W.; Xu, L.; De Vries, G. J.; Hoekstra, A. Y.

    2014-01-01

    Biofuels from microalgae are potentially important sources of liquid renewable energy. Algae are not yet produced on a large scale, but research shows promising results. This study assesses the blue water footprint (WF) and land use of algae-based biofuels. It combines the WF concept with an energy

  15. DYNAMICS OF ALGAE NUMBER AND BIOMASS OF STEPPE BIOGEOCOENOSES AND AGROCOENOSES IN KHERSON REGION

    Directory of Open Access Journals (Sweden)

    Shcherbina V.V.

    2011-12-01

    Full Text Available Characteristics of daily dynamics of seaweeds abundance and biomass were determined for steppe biogeocoenosis and agrocoenosis of Biosphere reserve “Askaniya-Nova” in spring of 2011. Fluctuation ranges in seaweeds abundance and biomass have been registered.Analyzing the indices of total number and algae biomass in studied biogeocoenoses it should be noted that the maximal values of alga number in virgin soil steppe exceeded minimal in 3,3 times; biomasses - in 2,1. For virgin soil steppe of post-fire-induced development the relation between maximum and minimal value of total number of algae was up to 2,1; biomass - 2,4. For agrocoenosis we noted the largest ranges in variation of number and biomass. In conditions of dry-land arable land the maximum values of total number of alga exceeded minimal in 21,9 times; biomasses - in 8,7; for irrigated arable land - in 12,5 and 5,6 respectively.In soil samples, selected within the limits of virgin soil biogeocoenoses of biosphere reserve “Askania-Nova” and agrocoenosis of dry-land and irrigated arable land in biosphere reserve by direct count, the algae species of Bacillariophyta, Cyanophyta, Chlorophyta, Xanthophyta and Eustigmatophyta have been found. The largest contribution to number and biomass of algae belonged to Bacillariophyta. The number and biomass of agrocoenosis algae is more dynamic feature, than for algae of virgin soil biogeocoenoses.

  16. Turf algae-mediated coral damage in coastal reefs of Belize, Central America

    KAUST Repository

    Wild, Christian

    2014-09-16

    Many coral reefs in the Caribbean experienced substantial changes in their benthic community composition during the last decades. This often resulted in phase shifts from scleractinian coral dominance to that by other benthic invertebrate or algae. However, knowledge about how the related role of coral-algae contacts may negatively affect corals is scarce. Therefore, benthic community composition, abundance of algae grazers, and the abundance and character of coral-algae contacts were assessed in situ at 13 Belizean reef sites distributed along a distance gradient to the Belizean mainland (12–70 km): Mesoamerican Barrier Reef (inshore), Turneffe Atoll (inner and outer midshore), and Lighthouse Reef (offshore). In situ surveys revealed significantly higher benthic cover by scleractinian corals at the remote Lighthouse Reef (26–29%) when compared to the other sites (4–19%). The abundance of herbivorous fish and the sea urchin Diadema antillarum significantly increased towards the offshore reef sites, while the occurrence of direct coral-algae contacts consequently increased significantly with decreasing distance to shore. About 60% of these algae contacts were harmful (exhibiting coral tissue damage, pigmentation change, or overgrowth) for corals (mainly genera Orbicella and Agaricia), particularly when filamentous turf algae were involved. These findings provide support to the hypothesis that (turf) algae-mediated coral damage occurs in Belizean coastal, near-shore coral reefs.

  17. Crustose coralline algae can suppress macroalgal growth and recruitment on Hawaiian coral reefs

    NARCIS (Netherlands)

    Vermeij, M.J.A.; Dailer, M.L.; Smith, C.M.

    2011-01-01

    Crustose coralline algae are important components of tropical reef communities because they promote successful settlement by corals and contribute to solidification of the reef framework. We show experimentally that crustose coralline algae are also capable of suppressing the growth and recruitment

  18. All Fiber-optic Fluorescent Spectral Measurement and Analysis on Alga Chla/c Characteristics

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The fluorescent principle used for measuring alga characteristic parameters and the optimum structure design of the instrument are discussed. The fluorescent spectrum of Chla/c and the time-resolved different spectrum ΔA(λ,t) are given. The research provides an effective method for considering the density and the classification of algae, which will be helpful to monitor sea pollution.

  19. BEBERAPA MARGA ALGA BENANG DAN HUBUNGANNYA DENGAN KEBERADAAN VEKTOR MALARIA DI BALI UTARA

    Directory of Open Access Journals (Sweden)

    I. G. Seregeg

    2012-09-01

    Full Text Available A study of filamentous algae and its relation to malaria vector control was conducted during the dry season in several lagoons at the north coast of Bali. Floating masses of these algae under the sunshine barricated the spread of solar-triton larvicide, reducing tremendously the effectiveness of the larvicide. Identification of the genera of these algae under the subphyllum of CYANOPHYTA (Blue Algae in the family of Cyanophyceae were Oscillatoria, Spirulina, Phormidium, Rivularia, Nostoc, and Anabaena; under the subphyllum of CHLOROPHYTA (Green Algae in the family of Chlorophyceae were Enteromorpha, Spirogyra, Mougeotia, Zygnema, and Oedogonium. The surface of water in between the floating masses of algae were an exellent breeding place of mosquitoes mainly Anopheles sundaicus. The density of Enteromorpha, the main attractant of An sundaicus compared to other filamantous algae, has no direct relation on the density of An. sundaicus larva. Hence Enteromorpha could only be considered as the indicator of the presence of larvae and not as the indicator of population densities of larvae Lagoons surrounded with mangrove plantations did not harbour filamentous algae and larvae of An. sundaicus were not found.

  20. Defined Media for Growth and Gamete Production by the Green Alga, Oedogonium cardiacum.

    Science.gov (United States)

    Hill, G J; Machlis, L

    1970-08-01

    Defined media consisting of inorganic salts and vitamin B(12) are described for the male and female filaments of the green alga, Oedogonium cardiacum. These media provide for a maximal growth rate and for the induction of oogonia and antheridia under the prescribed conditions. The maximal amounts of growth, based on dry weight measurements, compare favorably with other green algae.

  1. Spatiotemporal associations of reservoir nutrient characteristics and the invasive, harmful alga Prymnesium parvum in West Texas

    Science.gov (United States)

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Southard, Greg M.; Patino, Reynaldo

    2015-01-01

    Golden alga (Prymnesium parvum) is a harmful alga that has caused ecological and economic harm in freshwater and marine systems worldwide. In inland systems of North America, toxic blooms have nearly eliminated fish populations in some systems. Modifying nutrient profiles through alterations to land or water use may be a viable alternative for golden alga control in reservoirs. The main objective of this study was to improve our understanding of the nutrient dynamics that influence golden alga bloom formation and toxicity in west Texas reservoirs. We examined eight sites in the Upper Colorado River basin, Texas: three impacted reservoirs that have experienced repeated golden alga blooms; two reference reservoirs where golden alga is present but nontoxic; and three confluence sites downstream of the impacted and reference sites. Total, inorganic, and organic nitrogen and phosphorus and their ratios were quantified monthly along with golden alga abundance and ichthyotoxicity between December 2010 and July 2011. Blooms persisted for several months at the impacted sites, which were characterized by high organic nitrogen and low inorganic nitrogen. At impacted sites, abundance was positively associated with inorganic phosphorus and bloom termination coincided with increases in inorganic nitrogen and decreases in inorganic phosphorus in late spring. Management of both inorganic and organic forms of nutrients may create conditions in reservoirs unfavorable to golden alga.

  2. Fluorescence action spectra of algae and bean leaves at room and at liquid nitrogen temperatures

    NARCIS (Netherlands)

    Goedheer, J.C.

    1965-01-01

    Fluorescence action spectra were determined, both at room temperature and at liquid nitrogen temperature, with various blue-green, red and green algae, and greening bean leaves. The action spectra of algae were established with samples of low light absorption as well as dense samples. Fluorescence

  3. Uptake of caprolactam and its influence on growth and oxygen production of Desmodesmus quadricauda algae.

    Science.gov (United States)

    Kalinová, Jana Pexová; Tříska, Jan; Vrchotová, Naděžda; Novák, Jan

    2016-06-01

    The consumption of polyamides produced from caprolactam is increasing continuously, and for that reason the danger of environmental contamination by this lactam is also rising. This study's aim was to evaluate the influence of caprolactam on the growth and oxygen production of the green alga Desmodesmus quadricauda and on caprolactam uptake by this alga. The presence of caprolactam in water was observed to cause the algae significantly to increase its oxygen production. Caprolactam concentration of 5,000 mg/L stopped algae growth after 6 days and influenced coenobia structure (seen as disappearance of pyrenoids, deformation of cells) but did not decrease the number of cells in the coenobia. Caprolactam uptake is probably passive but relatively rapid. Maximum concentration in the algae was reached after 18-24 h.

  4. Cars will be fed on algae; Quand nos voitures rouleront aux algues

    Energy Technology Data Exchange (ETDEWEB)

    Peltier, G. [CEA-CNRS, Laboratoire de bioenergetique des bacteries et microalgues, Centre de Cadarache, 13108 Saint-Paul-les-Durance (France)

    2012-02-15

    The development of the first and second generations of bio-fuels has led to a rise in food prices and the carbon balance sheet is less good than expected. Great hopes have been put on unicellular algae for they can synthesize oils, sugar and even hydrogen and the competition with food production is far less harsh than with actual bio-fuels. Moreover, when you grow micro-algae, the loss of water through evaporation is less important than in the case of intensive farm cultures. In 2009 10.000 tonnes of micro-algae were produced worldwide, they were mainly used for the production of fish food and of complements for humane food (fat acids and antioxidants). Different research programs concern unicellular algae: they aim at modifying micro-algae genetically in order to give them a higher productivity or to make them produce an oil more adapted for motor fuel or more easily recoverable. (A.C.)

  5. Antioxidant response of the brown algae Dictyota dichotoma epiphytized by the invasive red macroalgae Lophocladia lallemandii

    Directory of Open Access Journals (Sweden)

    Silvia Tejada

    2014-05-01

    Full Text Available Objective: To evaluate the response of the brown alga Dictyota dichotoma (D. dichotoma epiphytized by the red alga Lophocladia lallemandii in Mallorca coastal waters (Balearic Islands by means of biomarker measures. Methods: Samples of epiphytized and non-epiphytized D. dichotoma were collected in Cala Morlanda (East Mallorca, Balearic Islands. Markers of lipid peroxidation and activities of antioxidant enzymes were measured in D. dichotoma. Results: Lipid peroxidation measured as malondialdehyde and all the antioxidant activities measured were significantly higher in the epiphytized brown algae when compared with the control algae. Conclusions: In conclusion, the invasive algae Lophocladia lallemandii seems to produce a more oxidized status in the epiphytized D. dichotoma and cellular damage that could induce increased mortality.

  6. Paleoecology of Late Carboniferous Phylloid Algae in Southern Guizhou,SW China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Phylloid algae are important reef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County,Guizhou Province. Phylloid algae growing closely packed are attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli are of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine organisms are relatively scarce.Obviously, phylloid algae are stronger competitors for living space than other co-occurring organisms.

  7. The future viability of algae-derived biodiesel under economic and technical uncertainties.

    Science.gov (United States)

    Brownbridge, George; Azadi, Pooya; Smallbone, Andrew; Bhave, Amit; Taylor, Benjamin; Kraft, Markus

    2014-01-01

    This study presents a techno-economic assessment of algae-derived biodiesel under economic and technical uncertainties associated with the development of algal biorefineries. A global sensitivity analysis was performed using a High Dimensional Model Representation (HDMR) method. It was found that, considering reasonable ranges over which each parameter can vary, the sensitivity of the biodiesel production cost to the key input parameters decreases in the following order: algae oil content>algae annual productivity per unit area>plant production capacity>carbon price increase rate. It was also found that the Return on Investment (ROI) is highly sensitive to the algae oil content, and to a lesser extent to the algae annual productivity, crude oil price and price increase rate, plant production capacity, and carbon price increase rate. For a large scale plant (100,000 tonnes of biodiesel per year) the production cost of biodiesel is likely to be £0.8-1.6 per kg.

  8. Cophylogenetics and biogeography reveal a coevolved relationship between sloths and their symbiont algae.

    Science.gov (United States)

    Fountain, Emily D; Pauli, Jonathan N; Mendoza, Jorge E; Carlson, Jenna; Peery, M Zachariah

    2017-05-01

    Specialized species, like arboreal folivores, often develop beneficial relationships with symbionts to exploit ecologically constrained lifestyles. Although coevolution can drive speciation by specialization of a symbiont to a host, a symbiotic relationship is not indicative of coevolution between host and symbiont. We tested for coevolved relationships between highly specialized two- and three-toed sloths (Choloepus spp. and Bradypus spp., respectively) and their symbiotic algae using cophylogenies and phylogeography. Our phylogeographic analysis showed a biogeographic pattern for the sloth distribution that was not found in the algal phylogeny. We found support for congruence between the sloth and algae phylogenies, implying cospeciation, only in the Bradypus lineage. Algae host-switching occurred from Bradypus spp. to Choloepus spp. Our results support a previously hypothesized symbiotic relationship between sloths and the algae in their fur and indicate that coevolution may have played a role in algae diversification. More broadly, convergent evolution may facilitate host switching between deeply diverged host lineages.

  9. Benthic soft-bodied algae as bioindicators of stream water quality

    Directory of Open Access Journals (Sweden)

    Stancheva R.

    2016-01-01

    Full Text Available This review presents the state-of-the-art of benthic soft-bodied algae as biondicators of stream and river water quality, with emphasis on bioassessments set by the legislation (e.g., European Water Framework Directive, USA Clean Water Act to promote the restoration and ensure ecological sustainability of water resources. The advantages and shortcomings of a variety of bioassessment field and laboratory methods for algae are discussed. The increasing use of soft-bodied algae in biotic indices to assess individual anthropogenic stressors, and in multimetric indices of biotic integrity to evaluate ecological condition in streams is summarized. Rapid microscopic and molecular approaches for inferring nutrient supply with heterocystous cyanobacteria and other sensitive algae are proposed. The need of better understanding of soft-bodied algae as bioindicators is discussed and suggestions are made for obtaining meaningful bioassessment information with cost-efficient efforts.

  10. [Hydrocarbons of the spiruline algae: nature, metabolism of heptadecane by rats and swine].

    Science.gov (United States)

    Tulliez, J; Bories, G; Boudene, C; Fevrier, C

    1975-01-01

    Hydrocarbons represent about half of the insaponifiable fraction of spirulina algae (0.1 to 0.3 p. 100 of the dry alga); n-heptadecane is the major component (65 p. 100). The retention of this paraffin has been measured in animals receiving these algae as the main or partial protein source. Rats fed with a diet containing 280 ppm n-heptadecane (25 p. 100 alga meal) from weaning show an accumulation of this hydrocarbon in the carcass the retention levels off after 4 months and seems related to the lipid content; preferential fixation occurs in adipose tissue. Sows receiving a diet with 52 ppm heptadecane (5p. 100 alga meal) during growth, pregnancy and lactation retain comparatively much less hydrocarbon; nevertheless n-heptadecane is excreted in the milk.

  11. Antioxidant response of the brown algae Dictyota dichotoma epiphytized by the invasive red macroalgae Lophocladia lallemandii

    Institute of Scientific and Technical Information of China (English)

    Silvia Tejada; Antoni Sureda

    2014-01-01

    Objective: To evaluate the response of the brown alga Dictyota dichotoma (D. dichotoma) epiphytized by the red alga Lophocladia lallemandii in Mallorca coastal waters (Balearic Islands) by means of biomarker measures. Methods: Samples of epiphytized and non-epiphytized D. dichotoma were collected in Cala Morlanda (East Mallorca, Balearic Islands). Markers of lipid peroxidation and activities of antioxidant enzymes were measured in D. dichotoma. Results: Lipid peroxidation measured as malondialdehyde and all the antioxidant activities measured were significantly higher in the epiphytized brown algae when compared with the control algae. Conclusions:In conclusion, the invasive algae Lophocladia lallemandii seems to produce a more oxidized status in the epiphytized D. dichotoma and cellular damage that could induce increased mortality.

  12. Red coralline algae assessed as marine pH proxies using 11B MAS NMR

    Science.gov (United States)

    Cusack, M.; Kamenos, N. A.; Rollion-Bard, C.; Tricot, G.

    2015-02-01

    Reconstructing pH from biogenic carbonates using boron isotopic compositions relies on the assumption that only borate, and no boric acid, is present. Red coralline algae are frequently used in palaeoenvironmental reconstruction due to their widespread distribution and regular banding frequency. Prior to undertaking pH reconstructions using red coralline algae we tested the boron composition of the red coralline alga Lithothamnion glaciale using high field NMR. In bulk analysed samples, thirty percent of boron was present as boric acid. We suggest that prior to reconstructing pH using coralline algae 1) species-specific boron compositions and 2) within-skeleton special distributions of boron are determined for multiple species. This will enable site selective boron analyses to be conducted validating coralline algae as palaeo-pH proxies based on boron isotopic compositions.

  13. Adsorption Studies of Lead by Enteromorpha Algae and Its Silicates Bonded Material

    Directory of Open Access Journals (Sweden)

    Hassan H. Hammud

    2014-01-01

    Full Text Available Lead adsorption by green Enteromorpha algae was studied. Adsorption capacity was 83.8 mg/g at pH 3.0 with algae (E and 1433.5 mg/g for silicates modified algae (EM. FTIR and thermal analysis of algae materials were studied. Thomas and Yoon-Nelson column model were best for adsorbent (E and algae after reflux (ER and Yan model for (EM with capacity 76.2, 71.1, and 982.5 mg/g, respectively. (ER and (EM show less swelling and better flow rate control than (E. Nonlinear methods are more appropriate technique. Error function calculations proved valuable for predicting the best adsorption isotherms, kinetics, and column models.

  14. Computational Visual Stress Level Analysis of Calcareous Algae Exposed to Sedimentation

    Science.gov (United States)

    Nilssen, Ingunn; Eide, Ingvar; de Oliveira Figueiredo, Marcia Abreu; de Souza Tâmega, Frederico Tapajós; Nattkemper, Tim W.

    2016-01-01

    This paper presents a machine learning based approach for analyses of photos collected from laboratory experiments conducted to assess the potential impact of water-based drill cuttings on deep-water rhodolith-forming calcareous algae. This pilot study uses imaging technology to quantify and monitor the stress levels of the calcareous algae Mesophyllum engelhartii (Foslie) Adey caused by various degrees of light exposure, flow intensity and amount of sediment. A machine learning based algorithm was applied to assess the temporal variation of the calcareous algae size (∼ mass) and color automatically. Measured size and color were correlated to the photosynthetic efficiency (maximum quantum yield of charge separation in photosystem II, ΦPSIImax) and degree of sediment coverage using multivariate regression. The multivariate regression showed correlations between time and calcareous algae sizes, as well as correlations between fluorescence and calcareous algae colors. PMID:27285611

  15. Ecotoxicological evaluation of marine sediments using free and immobilized phytoplanktonic algae

    Directory of Open Access Journals (Sweden)

    E. Giacco

    2011-01-01

    Full Text Available Marine sediments play an important role in the accumulation-storage and/or release of contaminants in seawaters; sedimets bioassays provide for general information on pollutant bioavailability. This work points out the importance to utilize free and immobilised (Na-alginate marine algae for the ecotoxicological evaluation of metals (Cd, Zn, Cu as well as of elutriates and whole sediment samples collected in harbour sites. The bioassay was carried out with the marine microalga Tetraselmis suecica; algal growth inhibition was determined after 24 and 48 hours as percent growth in comparison to controls. After 24 hours a lower toxicity of metals for the immobilised algae than for free algae was observed; this trend decreased in time. Algae exposed to whole sediment ahowed a greater reduction of growth than algae exposed to the relative elutriate. This result emphasizes that the whole sediments seem to be suitable to detect the toxicity of such complex environmental matrix.

  16. Sublethal concentrations of ichthyotoxic alga Prymnesium parvum affect rainbow trout susceptibility to viral haemorrhagic septicaemia virus

    DEFF Research Database (Denmark)

    Andersen, Nikolaj Gedsted; Lorenzen, Ellen; Boutrup, Torsten Snogdal;

    2016-01-01

    concentrations of the ichthyotoxic alga Prymnesium parvum affect the susceptibility of rainbow trout Oncorhynchus mykiss to viral haemorrhagic septicaemia virus (VHSV). During exposure to sublethal algal concentrations, the fish increased production of mucus on their gills. When fish were exposed to the algae...... for 12 h prior to the addition of virus, a marginal decrease in the susceptibility to VHSV was observed compared to fish exposed to VHSV without algae. If virus and algae were added simultaneously, inclusion of the algae increased mortality by 50% compared to fish exposed to virus only, depending...... on the experimental setup. We concluded that depending on the local exposure conditions, sublethal concentrations of P. parvum could affect susceptibility of fish to infectious agents such as VHSV....

  17. Algae of economic importance that accumulate cadmium and lead: a review

    Directory of Open Access Journals (Sweden)

    Priscila O. Souza

    2012-08-01

    Full Text Available Currently, algae and algae products are extensively applied in the pharmaceutical, cosmetic and food industries. Algae are the main organisms that take up and store heavy metals. Therefore, the use of compounds derived from algae by the pharmaceutical industry should be closely monitored for possible contamination. The pollution generated by heavy metals released by industrial and domestic sources causes serious changes in the aquatic ecosystem, resulting in a loss of biological diversity and a magnification and bioaccumulation of toxic agents in the food chain. Since algae are at the bottom of the aquatic food chain, they are the most important vector for transfer of pollution to upper levels of the trophic chain in aquatic environments. Moreover, microalgae are also used for the bioremediation of wastewater, a process that does not produce secondary pollution, that enables efficient recycling of nutrients and that generates biomass useful for the production of bioactive compounds and biofuel.

  18. Canonical Correspondence Analysis of Algae Composition and Its Environmental Factors of Typical Sections in Dongting Lake, China%洞庭湖典型断面藻类组成及其与环境因子典范对应分析

    Institute of Scientific and Technical Information of China (English)

    汪星; 郑丙辉; 刘录三; 李利强; 黄代中; 田琪

    2012-01-01

    This research was performed in 2010 at 6 sections of Dongting Lake, aiming to investigate the algal species. A total of 72 kinds of algal genera( species) belonging to 7 phyla were identified. The algae had an abundance ranging from 67.2×104 cells·L-1 to 161.9×104 and obviously different across the sampling sections in the three seasons, for example, Nanzui had the highest and Wanzi Lake had the lowest mean alga] abundance across the 6 sampling sections. The algal community was dominated by Bacillariophyta and Cryptophyta, and significant difference was found on algal composition across 6 sampling sections. Overall, Margalef values varied from 3.64 to 4.03, while Shannon-Wienner varying from 3.03 to 3.24, both showing well water quality. Canonical correspondence analysis! CCA ) was applied to explore the relationship between algal species and environmental parameters by CANOCO 4.5. The species-environment biplots were drawn based by the result of CCA. The result showed that dissolved oxygenf DO) and total nitrogen(TN) were the most important factors influencing the distribution of algal species across the 6 typical sections, for example, Cymbella sp., Merismopedia sp., Navicula sp., Nitzschia sp., and Gyrosigma sp. were chiefly influenced by DO, while Melosira sp., CycloLella sp., Cryptomonas sp., Euglena sp., Peridinium sp., and Stephanodiscus sp. were chiefly influenced byTN, and Ankistrodesmus sp., Scenedesmus sp. and Synedra sp. were chiefly influenced by both DO and TN. Besides these, the other factors just like biochemical and chemical oxygen demand, total phosphorus(TP) and pH were also important to the algal species.%2010年对洞庭湖6个典型断面进行了浮游藻类生物调查,共鉴定出7门72属(种),浮游藻类的密度范围在67.2×104~161.9×104cell·L-1;各典型断面间浮游藻类组成以硅藻和隐藻占优势,藻类群落结构存在着明显的差异.藻类Margalef指数及Shannon-Wienner指数范围分别为3.64~4.03和3

  19. Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

    Science.gov (United States)

    Reyes-Nivia, C.; Diaz-Pulido, G.; Dove, S.

    2014-09-01

    The susceptibility of crustose coralline algae (CCA) skeletons to dissolution is predicted to increase as oceans warm and acidify. Skeletal dissolution is caused by bioerosion from endolithic microorganisms and by chemical processes associated with undersaturation of carbonate minerals in seawater. Yet, the relative contribution of algal microborers and seawater carbonate chemistry to the dissolution of organisms that cement reefs under projected pCO2 and temperature (pCO2-T) scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes) to four pCO2-T treatments (pre-industrial, present-day, SRES-B1 "reduced" pCO2, and SRES-A1FI "business-as-usual" pCO2 emission scenarios) under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200%) than those colonized by endolithic algae across all pCO2-T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harbouring photosynthetic microborers will be less impacted than those without algal endoliths.

  20. Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

    Directory of Open Access Journals (Sweden)

    C. Reyes-Nivia

    2014-02-01

    Full Text Available The susceptibility of crustose coralline algae (CCA skeletons to dissolution is predicted to increase as oceans warm and acidify. Skeletal dissolution is caused by bioerosion from endolithic microorganisms and by chemical processes associated with undersaturation of carbonate minerals in seawater. Yet, the relative contribution of algal microborers and seawater carbonate chemistry to the dissolution of organisms that cement reefs under projected CO2 and temperature (CO2-T scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes to four CO2-T treatments (pre-industrial, present-day, SRES-B1 reduced CO2 emission scenario, SRES-A1FI business-as-usual CO2 emission scenario under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200% than those colonized by endolithic algae across all CO2-T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harboring photosynthetic microborers will be less impacted than those without algal endoliths.

  1. Muscle antioxidant (vitamin E) and major fatty acid groups, lipid oxidation and retail colour of meat from lambs fed a roughage based diet with flaxseed or algae.

    Science.gov (United States)

    Ponnampalam, Eric N; Burnett, Viv F; Norng, Sorn; Hopkins, David L; Plozza, Tim; Jacobs, Joe L

    2016-01-01

    The effect of feeding flaxseed or algae supplements to lambs on muscle antioxidant potential (vitamin E), major fatty acid groups, lipid oxidation and retail colour was investigated. Lambs (n=120) were randomly allocated to one of 4 dietary treatments according to liveweight and fed the following diets for eight weeks: Annual ryegrass hay [60%]+subterranean clover hay [40%] pellets=Basal diet; Basal diet with flaxseed (10.7%)=Flax; Basal diet with algae (1.8%)=Algae; Basal diet with flaxseed (10.7%) and algae (1.8%)=FlaxAlgae. Flaxseed or algae supplementation significantly affected major fatty acid groups in muscle. The addition of algae (average of Algae and FlaxAlgae) resulted in lower vitamin E concentration in muscle (Pdiet without algae (average of Basal and Flax). Increasing muscle EPA+DHA by algae supplementation significantly increased lipid oxidation, but retail display colour of fresh meat was not affected.

  2. Self-deconstructing algae biomass as feedstock for transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Ryan Wesley [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Biomass Science and Conversion Technologies

    2014-09-01

    The potential for producing biofuels from algae has generated much excitement based on projections of large oil yields with relatively little land use. However, numerous technical challenges remain for achieving market parity with conventional non-renewable liquid fuel sources. Among these challenges, the energy intensive requirements of traditional cell rupture, lipid extraction, and residuals fractioning of microalgae biomass have posed significant challenges to the nascent field of algal biotechnology. Our novel approach to address these problems was to employ low cost solution-state methods and biochemical engineering to eliminate the need for extensive hardware and energy intensive methods for cell rupture, carbohydrate and protein solubilization and hydrolysis, and fuel product recovery using consolidated bioprocessing strategies. The outcome of the biochemical deconstruction and conversion process consists of an emulsion of algal lipids and mixed alcohol products from carbohydrate and protein fermentation for co-extraction or in situ transesterification.

  3. Alternate-Fueled Flight: Halophytes, Algae, Bio-, and Synthetic Fuels

    Science.gov (United States)

    Hendricks, R. C.

    2012-01-01

    Synthetic and biomass fueling are now considered to be near-term aviation alternate fueling. The major impediment is a secure sustainable supply of these fuels at reasonable cost. However, biomass fueling raises major concerns related to uses of common food crops and grasses (some also called "weeds") for processing into aviation fuels. These issues are addressed, and then halophytes and algae are shown to be better suited as sources of aerospace fuels and transportation fueling in general. Some of the history related to alternate fuels use is provided as a guideline for current and planned alternate fuels testing (ground and flight) with emphasis on biofuel blends. It is also noted that lessons learned from terrestrial fueling are applicable to space missions. These materials represent an update (to 2009) and additions to the Workshop on Alternate Fueling Sustainable Supply and Halophyte Summit at Twinsburg, Ohio, October 17 to 18, 2007.

  4. Antithrombotic effects of bromophenol, an alga-derived thrombin inhibitor

    Science.gov (United States)

    Shi, Dayong; Li, Xiaohong; Li, Jing; Guo, Shuju; Su, Hua; Fan, Xiao

    2010-01-01

    Thrombin, the ultimate proteinase of the coagulation cascade, is an attractive target for the treatment of a variety of cardiovascular diseases. A bromophenol derivative named (+)-3-(2,3-dibromo-4, 5-dihydroxy-phenyl)-4-bromo-5,6-dihydroxy-1,3-dihydroiso-benzofuran 1, isolated from the brown alga Leathesia nana exhibited significant thrombin inhibitory activity. In this study, we investigated the inhibition of human thrombin in vitro with this bromophenol derivative, and its antithrombotic efficacy in vivo using the arteriovenous shunt model and the ferric chloride-induced arterial thrombosis model in rats. The results show that the bromophenol derivative is a potential inhibitor of thrombin (IC50=1.03 nmol/L). In antithrombotic experiments in vivo, the bromophenol derivative also shows good effect comparing with the control group. These data indicate that the bromophenol derivative is a potential drug for prophylaxis and the treatment of thrombotic diseases.

  5. Convergence of joint mechanics in independently evolving, articulated coralline algae.

    Science.gov (United States)

    Janot, Kyra; Martone, Patrick T

    2016-02-01

    Flexible joints are a key innovation in the evolution of upright coralline algae. These structures have evolved in parallel at least three separate times, allowing the otherwise rigid, calcified thalli of upright corallines to achieve flexibility when subjected to hydrodynamic stress. As all bending occurs at the joints, stress is amplified, which necessitates that joints be made of material that is both extensible and strong. Data presented here indicate that coralline joints are in fact often stronger and more extensible, as well as tougher, than fleshy seaweed tissues. Corallinoids are particularly strong and tough, which is largely due to the presence of secondary cell walls that strengthen the joint tissue without adding bulk to the joint itself. Cell wall thickness is shown to be a large contributing factor to strength across all groups, with the exception of the corallinoid Cheilosporum sagittatum, which likely possesses distinct chemical composition in its walls to increase strength beyond that of all other species tested.

  6. Effects of the insecticide Zectran (Mexacarbate) on several algae.

    Science.gov (United States)

    Sheridan, R P; Simms, M A

    1975-05-01

    Field samples of freshwater algae were examined to determine the effect of the insecticide Zectran on photosynthesis rate. Concentrations of Zectran between 10 and 10(3) parts per billion (ppb) affected neither O2 production nor NaH14CO3 uptake in any of the seven genera tested. However, Zectran at a concentration of 10(4) ppb after 1 hour effected a reduction in photosynthesis of Chroococcus, Oedogonium and in a mixed sample composed of Zygnema,Mougeotia and Spirogyra. Mougeotia, Spirogyra and Schizogonium were not affected by exposure to 10(4) ppb Zectran after 1 hour, but O2 production was significantly reduced after 24 hours of exposure to this same concentration.

  7. [Gamma-radiation action on cells of algae Euglena gracilis].

    Science.gov (United States)

    Glinkova, E; Zhuchkina, N I; Koltovoĭ, N A; Koltovaia, N A

    2012-01-01

    Considering the potentials of algae Euglena to constitute a part of biological systems of human life support, effects of low radiation doses on algal cells and radiosensitivity dependence on their genotype were studied. In experiments with gamma-irradiation (60Co) of Euglena gracilis, the highest radioresistance was demonstrated by strain Z. OFL; the chloroplasts lacking Z-derived strain showed hypersensitivity to radiation. E. bacillaris and derived chlorophyll-lacking strains W3 and W10 had intermediate radiosensitivity. Irradiation with the doses of up to 10 Gy produced a hormetic effect in the stock strains. Cells death was observed only after irradiation by doses above 100 Gy. The stimulating effect was exerted both on radioresistance and growth rate. Dyes made possible rapid evaluation of the proportion of living and dead cells. Comparison of two survival tests showed that the classic medium inoculation overestimates cell deaths as it disregards the living non-proliferating cells.

  8. A method to extract algae toxin of microcystin-LR

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-ming; PAN Gang; YAN Hai; CHEN Hao

    2004-01-01

    A simple and Iow-cost method to obtain cyanobacterial toxin microcystin-LR(MC-LR) was developed. A new strain of Microcystis aeruginosa, named DC-1, producing microcystin-LR but not microcystin-RR, was separated from the field blooming algae samples of Dianchi Lake, in southwest of China. Following three times'freeze and thaw treatment, the cultivated DC-1 cells were extracted with 40% methanol in water. The extract was centrifuged and the supernatant applied to a Hydrophilic-Lipophilic Balance(HLB) SPE cartridge. Eluted impurities with a certain gradient from 30% to 50% methanol in water, MC-LR was finally eluted from the HLB cartridge with 60 % methanol in water, and samples containing 3.85 % to 14.8 % of MC-LR were obtained. These MC-LR samples may be used in adsorption and biodegradation experiments instead of using expensive standard reagents.

  9. Fucoidans from brown alga Fucus evanescens: structure and biological activity

    Directory of Open Access Journals (Sweden)

    Roza Menshova

    2016-08-01

    Full Text Available Brown alga Fucus evanescens, widespread in the Far Eastern seas of Russia, is valuable source of sulfated polysaccharides – fucoidans with beneficial biological activities. The most homogenous fraction of fucoidan from F. evanescens was shown to be molecule containing linear main chain of alternating 2-sulfated 1,3- and 1,4-linked α-L-fucose residues. Few sulfate groups were found in position 4 of some 1,3-linked fucose residues. Acetyl groups occupied free C-3 of 1,4-linked residues and/or the C-4 of 1,3-linked fucose residues. Enzymatic hydrolysis, mild acid hydrolysis and autohydrolysis of native fucoidan were used for elucidation of the fine structural characteristics of fucoidan from F. evanescens. The aim of this review to summarize published data on biological activities of fucoidan from F. evanescens: antiviral, anticoagulant, thrombolytic, hepatoprotective, immunomodulatory, anticancer, and their practical application.

  10. The cellulose synthase superfamily in fully sequenced plants and algae

    Directory of Open Access Journals (Sweden)

    Xu Ying

    2009-07-01

    Full Text Available Abstract Background The cellulose synthase superfamily has been classified into nine cellulose synthase-like (Csl families and one cellulose synthase (CesA family. The Csl families have been proposed to be involved in the synthesis of the backbones of hemicelluloses of plant cell walls. With 17 plant and algal genomes fully sequenced, we sought to conduct a genome-wide and systematic investigation of this superfamily through in-depth phylogenetic analyses. Results A single-copy gene is found in the six chlorophyte green algae, which is most closely related to the CslA and CslC families that are present in the seven land plants investigated in our analyses. Six proteins from poplar, grape and sorghum form a distinct family (CslJ, providing further support for the conclusions from two recent studies. CslB/E/G/H/J families have evolved significantly more rapidly than their widely distributed relatives, and tend to have intragenomic duplications, in particular in the grape genome. Conclusion Our data suggest that the CslA and CslC families originated through an ancient gene duplication event in land plants. We speculate that the single-copy Csl gene in green algae may encode a mannan synthase. We confirm that the rest of the Csl families have a different evolutionary origin than CslA and CslC, and have proposed a model for the divergence order among them. Our study provides new insights about the evolution of this important gene family in plants.

  11. Evidence for methane production by the marine algae Emiliania huxleyi

    Science.gov (United States)

    Lenhart, Katharina; Klintzsch, Thomas; Langer, Gerald; Nehrke, Gernot; Bunge, Michael; Schnell, Sylvia; Keppler, Frank

    2016-06-01

    Methane (CH4), an important greenhouse gas that affects radiation balance and consequently the earth's climate, still has uncertainties in its sinks and sources. The world's oceans are considered to be a source of CH4 to the atmosphere, although the biogeochemical processes involved in its formation are not fully understood. Several recent studies provided strong evidence of CH4 production in oxic marine and freshwaters, but its source is still a topic of debate. Studies of CH4 dynamics in surface waters of oceans and large lakes have concluded that pelagic CH4 supersaturation cannot be sustained either by lateral inputs from littoral or benthic inputs alone. However, regional and temporal oversaturation of surface waters occurs frequently. This comprises the observation of a CH4 oversaturating state within the surface mixed layer, sometimes also termed the "oceanic methane paradox". In this study we considered marine algae as a possible direct source of CH4. Therefore, the coccolithophore Emiliania huxleyi was grown under controlled laboratory conditions and supplemented with two 13C-labeled carbon substrates, namely bicarbonate and a position-specific 13C-labeled methionine (R-S-13CH3). The CH4 production was 0.7 µg particular organic carbon (POC) g-1 d-1, or 30 ng g-1 POC h-1. After supplementation of the cultures with the 13C-labeled substrate, the isotope label was observed in headspace CH4. Moreover, the absence of methanogenic archaea within the algal culture and the oxic conditions during CH4 formation suggest that the widespread marine algae Emiliania huxleyi might contribute to the observed spatially and temporally restricted CH4 oversaturation in ocean surface waters.

  12. Developing a Forward Model of Encrusting Coralline Algae

    Science.gov (United States)

    Ng, J.; Williams, B.; Thompson, D. M.; Halfar, J.

    2014-12-01

    Climate proxy data has traditionally been interpreted through inverse models, which extract physical climate variables from proxy variables. This approach assumes stationarity of the proxy-climate relationship, typically reduces climate signal to a single variable, and requires extensive observational records. In contrast, forward models reverse the relationship, simulating proxy variables from physical climate variables for comparison to observed proxy variables. Since this approach accounts for multiple climate variables and avoids stationarity issues, forward models have been developed for several climate proxies, including tree ring width and oxygen stable isotopes (δ18O) of corals. Here we develop a basic forward model for the climate archive coralline alga Clathromorphum sp.This long-lived alga grows in mid-to-high latitude regions and forms a solid calcite skeleton with annual growth bands similar to those of trees and tropical corals. Sub-annually resolved δ18O in annual growth bands (δ18Ospec) provide a record of local environmental and climatic factors, notably sea surface temperature (SST) and sea water oxygen stable isotopes (δ18Osw). We model Clathromorphum δ18Ospec in the Aleutian islands from gridded SST and δ18Osw of the growing season from 1960 to 2004. The strongest climate signal is observed in July, likely due to suppressed growth in other months. Initial results suggest no influence of growth rate on the fractionation of oxygen isotopes and indicate that δ18Ospec anomalies are significantly correlated with summer SST anomalies. We run this forward model with observed SST and δ18Osw and compare the resulting simulated δ18Ospec with that measured in live-collected specimens. This foundational model may be adapted to other regions and modified to include other variables influencing coralline isotope records, such as light availability and ice coverage.

  13. Cytofluorometric determination of nuclear DNA in living and preserved algae.

    Science.gov (United States)

    Hull, H M; Hoshaw, R W; Wang, J C

    1982-09-01

    Three DNA-localizing fluorochromes used in conjunction with epi (incident) UV illumination were examined for sensitivity and selectivity for the cytofluorometric determination of nuclear DNA in ten species of six algal genera: Mougeotia, Oedogonium, Sirogonium, Spirogyra and Zygnema among the green algae, and the marine red alga Polysiphonia boldii. In comparison with absorption photometry for the determination of nuclear DNA, the cytofluorometric procedure proved to be simpler and considerably more sensitive. Following staining with 4',6-diamidino-2-phenylindole (DAPI), nuclei fluoresce blue-white, the fluorescence intensity of the DNA-DAPI complex being considerably greater than that of the unbound dye molecule. Algal strains stained with 2,5-bis[4'-aminophenyl(1')]-1,3,4-oxadiazole (BAO) also showed brilliant blue-white nuclear fluorescence. Although the BAO schedule requires the use of freshly prepared dye and sulfite water, and careful control of hydrolysis, nuclear fluorescence of the stained specimens does not fade under irradiation of the UV beam as rapidly as it does with certain other fluorochrome procedures. A more useful fluorochrome was the fungal antibiotic mithramycin. Its staining schedule is simple and the bright orange-yellow fluorescence of the nuclei is associated with an exceptional degree of sensitivity and specificity for DNA. Forty-eight-year-old preserved filaments of Spirogyra jatobae, stained with either BAO or mithramycin, exhibited a fluorescence brilliance of nuclear and chloroplast DNA equal to that of fresh specimens of this species. The three schedules, but particularly the one with mithramycin, have proven useful in providing indirect evidence for variation in ploidy level in several of the above algal genera, and in verifying the assumed ploidy level of the gametophyte (haploid) and tetrasporophyte (diploid) of Polysiphonia boldii.

  14. Effect of Alexandrium tamarense on three bloom-forming algae

    Science.gov (United States)

    Yin, Juan; Xie, Jin; Yang, Weidong; Li, Hongye; Liu, Jiesheng

    2010-07-01

    We investigated the allelopathic properties of Alexandrium tamarense (Laboar) Balech on the growth of Prorocentrum donghaiense Lu, Chattonella marina (Subrahmanyan) Hara et Chihara and Heterosigma akashiwo (Hada) Hada in a laboratory experiment. We examined the growth of A. tamarense, C. marina, P. donghaiense and H. Akashiwo in co-cultures and the effect of filtrates from A. tamarense cultures in various growth phases, on the three harmful algal bloom (HAB)-forming algae. In co-cultures with A. tamarense, both C. marina and H. akashiwo were dramatically suppressed at high cell densities; in contrast, the growth of P. donghaiense varied in different inoculative ratios of A. tamarense and P. donghaiense. When the ratio was 1:1 ( P. donghaiense: A. tamarense), growth of P. donghaiense was inhibited considerably, while the growth of P. donghaiense was almost the same as that of the control when the ratio was 9:1. The growth difference of P. donghaiense, C. marina and H. akashiwo when co-cultured with A. tamarense indicated that the allelopathic effect may be one of the important factors in algal competition and phytoplankton succession involving A. tamarense. In addition, the filtrate from A. tamarense culture had negative impacts on these three HAB algae, and such inhibition varied with different growth phases of A. tamarense in parallel with reported values of PSP toxin content in Alexandrium cells. This implied that PSP toxin was possibly involved in allelopathy of A. tamarense. However, the rapid decomposition and inactivation of PSP toxin above pH 7 weakened this possibility. Further studies on the allelochemicals responsible for the allelopathy of A. tamarense need to be carried out in future.

  15. Natural impacted freshwaters: in situ use of alginate immobilized algae to the assessment of algal response.

    Science.gov (United States)

    Corrêa, A X R; Tamanaha, M S; Horita, C O; Radetski, M R; Corrêa, R; Radetski, C M

    2009-05-01

    The objective of this study was to investigate the feasibility of an in situ phytotoxicity test using alginate-immobilized algae for 60 days, in the assessment of water quality in an impacted small peri-urban stream. After laboratory optimization of algae immobilization/de-immobilization processes, the performance of immobilized/de-immobilized algae was compared to the performance of free algae in terms of specific algal growth and sensitivity. This was done by comparing 72 h EC50 values obtained with zinc and the pesticides clomazone and carbofuran. The results showed a similar performance, which allow us to conclude that immobilization for 60 days do not cause any significant alteration in algae physiology. In the field, immobilized algae were exposed at different times (2, 4 and 7 days) to water samples in both disturbed and undisturbed sites. Both laboratory and field experiments indicated that alginate-immobilized algae for 60 days were sufficiently sensitive for use in the in situ assessment of water quality.

  16. Landfill leachate--a water and nutrient resource for algae-based biofuels.

    Science.gov (United States)

    Edmundson, Scott J; Wilkie, Ann C

    2013-01-01

    There is a pressing need for sustainable renewable fuels that do not negatively impact food and water resources. Algae have great potential for the production of renewable biofuels but require significant water and fertilizer resources for large-scale production. Municipal solid waste (MSW) landfill leachate (LL) was evaluated as a cultivation medium to reduce both water and elemental fertilizer demands of algae cultivation. Daily growth rate and cell yield of two isolated species of algae (Scenedesmus cf. rubescens and Chlorella cf. ellipsoidea) were cultivated in MSW LL and compared with Bold's Basal Medium (BBM). Results suggest that LL can be used as a nutrient resource and medium for the cultivation of algae biomass. S. cf. rubescens grew well in 100% LL, when pH was regulated, with a mean growth rate and cell yield 91.2% and 92.8% of those observed in BBM, respectively. S. cf. rubescens was more adaptable than C. cf. ellipsoidea to the LL tested. The LL used in this study supported a maximum volumetric productivity of 0.55 g/L/day of S. cf. rubescens biomass. The leachate had sufficient nitrogen to supply 17.8 g/L of algae biomass, but was limited by total phosphorus. Cultivation of algae on LL offsets both water and fertilizer consumption, reducing the environmental footprint and increasing the potential sustainability of algae-based biofuels.

  17. Changes of Cellular Superficial Configuration of Symbiotic Algae During Cultivation from Two Anemones Found in the South China Sea

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Symbiotic algae from two anemones, Radianthus macrodactylus and Stichodactyla mertensii, found in the South China Sea, were cultivated in ASP-8A medium in this study. Changes of superficial configuration of symbiotic algae during the cultivation were studied by means of a microscope and a scanning electron microscope (SEM). A number of small cavities appeared on the surfaces of symbiotic algae after they were cultivated for 10 h. The cavities enlarged and the cell contents were lost with extended cultivation. Our data suggested that the presence of cavities on symbiotic algae surfaces may be one of the main reasons for failure to culture symbiotic algae in an artificial medium.

  18. Platinum anniversary: virus and lichen alga together more than 70 years.

    Directory of Open Access Journals (Sweden)

    Karel Petrzik

    Full Text Available Trebouxia aggregata (Archibald Gärtner (phylum Chlorophyta, family Trebouxiaceae, a lichen symbiotic alga, has been identified as host of the well-known herbaceous plant virus Cauliflower mosaic virus (CaMV, family Caulimoviridae. The alga had been isolated from Xanthoria parietina more than 70 years ago and has been maintained in a collection since that time. The CaMV detected in this collection entry has now been completely sequenced. The virus from T. aggregata is mechanically transmissible to a herbaceous host and induces disease symptoms there. Its genome differs by 173 nt from the closest European CaMV-D/H isolate from cauliflower. No site under positive selection was found on the CaMV genome from T. aggregata. We therefore assume that the virus's presence in this alga was not sufficiently long to fix any specific changes in its genome. Apart from this symbiotic alga, CaMV capsid protein sequences were amplified from many other non-symbiotic algae species maintained in a collection (e.g., Oonephris obesa, Elliptochloris sp., Microthamnion kuetzingianum, Chlorella vulgaris, Pseudococcomyxa sp.. CaMV-free Chlorella vulgaris was treated with CaMV to establish virus infection. The virus was still detected there after five passages. The virus infection is morphologically symptomless on Chlorella algae and the photosynthesis activity is slightly decreased in comparison to CaMV-free alga culture. This is the first proof as to the natural presence of CaMV in algae and the first demonstration of algae being artificially infected with this virus.

  19. Energy Productivity of the High Velocity Algae Raceway Integrated Design (ARID-HV)

    Energy Technology Data Exchange (ETDEWEB)

    Attalah, Said; Waller, Peter M.; Khawam, George; Ryan, Randy D.; Huesemann, Michael H.

    2015-06-03

    The original Algae Raceway Integrated Design (ARID) raceway was an effective method to increase algae culture temperature in open raceways. However, the energy input was high and flow mixing was poor. Thus, the High Velocity Algae Raceway Integrated Design (ARID-HV) raceway was developed to reduce energy input requirements and improve flow mixing in a serpentine flow path. A prototype ARID-HV system was installed in Tucson, Arizona. Based on algae growth simulation and hydraulic analysis, an optimal ARID-HV raceway was designed, and the electrical energy input requirement (kWh ha-1 d-1) was calculated. An algae growth model was used to compare the productivity of ARIDHV and conventional raceways. The model uses a pond surface energy balance to calculate water temperature as a function of environmental parameters. Algae growth and biomass loss are calculated based on rate constants during day and night, respectively. A 10 year simulation of DOE strain 1412 (Chlorella sorokiniana) showed that the ARID-HV raceway had significantly higher production than a conventional raceway for all months of the year in Tucson, Arizona. It should be noted that this difference is species and climate specific and is not observed in other climates and with other algae species. The algae growth model results and electrical energy input evaluation were used to compare the energy productivity (algae production rate/energy input) of the ARID-HV and conventional raceways for Chlorella sorokiniana in Tucson, Arizona. The energy productivity of the ARID-HV raceway was significantly greater than the energy productivity of a conventional raceway for all months of the year.

  20. Propriedades bioativas dos polissacarídeos sulfatados da alga comestível Gracilaria birdiae

    OpenAIRE

    Oliveira, Letícia Castelo Branco Peroba de

    2014-01-01

    As algas marinhas vermelhas do gênero gracilaria sintetizam polissacarídeos sulfatados (PS) bioativos. Porém muitos destes PS ainda não foram devidamente avaliados, como é caso dos PS sintetizados pela alga comestível Gracilaria birdiae. Estudos anteriores mostraram que galactanas sulfatadas dessa alga tem efeito antiinflamatorio. Neste trabalho uma galactana (GB) de G. birdiae foi obtida e avaliada por diferentes testes. GB apresentou atividade anticoagulante no teste de APTT. Gb não apresen...

  1. Studies on Biquaternary Ammonium Salt Algaecide for Removing Red Tide Algae

    Institute of Scientific and Technical Information of China (English)

    刘洁生; 张珩; 杨维东; 高洁; 柯琼

    2004-01-01

    The paper deals with the removal and control of red tide algae, Phaeoecystis globosa and Alexandrium tamarense by biquaternary ammonium salt algaecide. The results show that the efficient concentration of biquaternary ammonium salt to control the two algaes in 96 h is 0.8 mg · L-1 and 0.4 mg · L-1, respectively. It is found that biquaternary ammonium salt has high efficiency and longer duration of action in the removal and control of algae.Biquaternary ammonium salt might be an excellent algaecide to control HAB.

  2. Study on the Adsorption of Metal Ions by Immobilized Marine Algae with the Existence of Clay

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay,the adsorption rate increases rapidly with the increasing amount of the marine algae. When pH=5, the best ratio between the clay and the marine algae is 1:4 for Pb2+. The result of in situ handling of the waste water containing heavy metals shows that the average adsorption rates of heavy metal irons Cu2+, Cd2+, Pb2+ and Ni2+ are all over 70 %.

  3. Natural Abundance 14C Content of Dibutyl Phthalate (DBP from Three Marine Algae

    Directory of Open Access Journals (Sweden)

    Kazuyo Ukai

    2006-11-01

    Full Text Available Abstract: Analysis of the natural abundance 14C content of dibutyl phthalate (DBP from two edible brown algae, Undaria pinnatifida and Laminaria japonica, and a green alga, Ulva sp., revealed that the DBP was naturally produced. The natural abundance 14C content of di-(2-ethylhexyl phthalate (DEHP obtained from the same algae was about 50-80% of the standard sample and the 14C content of the petrochemical (industrial products of DBP and DEHP were below the detection limit.

  4. Aquaculture: Algae. (Latest citations from the Life Sciences Collection data base). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The bibliography contains citations concerning the commercial cultivation of algae as a facet of aquaculture. Topics include descriptions and characteristics of algal species, environmental variables affecting productivity, nutritional aspects, infestation and disease, genetic manipulation, and production technology. End product applications examine algae as biomass for energy production, food source for humans, animal feed source, and a source for chemical by-products such as chlorophylls. Harvesting of algae as a source of single-celled protein is referenced in a related bibliography. (Contains a minimum of 171 citations and includes a subject term index and title list.)

  5. Effect of Feeding with Algae on Fatty Acid Profile of Goat’S Milk

    OpenAIRE

    2014-01-01

    The study was conducted to determine whether the inclusion of algae Chlorella vulgaris in dairy goats’ diets would change the fatty acid profile and increase the proportion of unsaturated fatty acids in goat’s milk. White short-haired dairy goats on 2nd and 3rd lactations were fed 5 and 10 g of dried algae supplementation for six weeks. The fatty acids profile of milk was analyzed using gass chromatography (flame ionization detector (FID)). The addition of dried algae caused changes of the pr...

  6. BIOSORPTION OF Cr(III) ION ON ALGAE Eucheuma spinosum BIOMASSA

    OpenAIRE

    Sudiarta, I. Wayan; Diantariani, Ni Putu

    2010-01-01

    Studies on biosorption and desorption of Cr(III) on algae (Eucheuma spinosum) adsorbent have been carried out. These studies included determination of biosorbent acidity, optimum pH, contact time of biosorption, isoterm and biosorption capacity, and mechanisms of interaction between Cr(III) and algae (E. spinosum) biosorben. Mechanisms of interaction were evaluated by sequential desorption of Cr(III) on algae biosorben by using aquadest, 1 M HCl and 0.05 M Na2EDTA. The result showed that the ...

  7. Use of Copper to Selectively Inhibit Brachionus calyciflorus (Predator Growth in Chlorella kessleri (Prey Mass Cultures for Algae Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Vishnupriya Pradeep

    2015-08-01

    Full Text Available A single Brachionus rotifer can consume thousands of algae cells per hour causing an algae pond to crash within days of infection. Thus, there is a great need to reduce rotifers in order for algal biofuel production to become reality. Copper can selectively inhibit rotifers in algae ponds, thereby protecting the algae crop. Differential toxicity tests were conducted to compare the copper sensitivity of a model rotifer—B. calyciflorus and an alga, C. kessleri. The rotifer LC50 was <0.1 ppm while the alga was not affected up to 5 ppm Cu(II. The low pH of the rotifer stomach may make it more sensitive to copper. However, when these cultures were combined, a copper concentration of 1.5 ppm was needed to inhibit the rotifer as the alga bound the copper, decreasing its bioavailability. Copper (X ppm had no effect on downstream fatty acid methyl ester extraction.

  8. Effects of extreme seasonality on community structure and functional group dynamics of coral reef algae in the southern Red Sea (Eritrea)

    NARCIS (Netherlands)

    Ateweberhan, M.; Bruggemann, J. H.; Breeman, A. M.

    2006-01-01

    Spatial and temporal variation in the biomass of four functional groups of coral reef algae (canopy algae, foliose algae, turf algae and crustose corallines) was investigated in the southern Red Sea. This region is characterised by extremely high summer temperatures (ca. 35 degrees C). Strong season

  9. Enhancement of biodiesel production from different species of algae

    Directory of Open Access Journals (Sweden)

    El-Moneim M. R. Afify, Abd

    2010-12-01

    Full Text Available Eight algal species (4 Rhodo, 1 chloro and 1 phaeophycean macroalgae, 1 cyanobacterium and 1 green microalga were used for the production of biodiesel using two extraction solvent systems (Hexane/ether (1:1, v/v and (Chloroform/ methanol (2:1, v/v. Biochemical evaluations of algal species were carried out by estimating biomass, lipid, biodiesel and sediment (glycerin and pigments percentages. Hexane/ ether (1:1, v/v extraction solvent system resulted in low lipid recoveries (2.3-3.5% dry weight while; chloroform/methanol (2: 1, v/v extraction solvent system was proved to be more efficient for lipid and biodiesel extraction (2.5 – 12.5% dry weight depending on algal species. The green microalga Dictyochloropsis splendida extract produced the highest lipid and biodiesel yield (12.5 and 8.75% respectively followed by the cyanobacterium Spirulina platensis (9.2 and 7.5 % respectively. On the other hand, the macroalgae (red, brown and green produced the lowest biodiesel yield. The fatty acids of Dictyochloropsis splendida Geitler biodiesel were determined using gas liquid chromatography. Lipids, biodiesel and glycerol production of Dictyochloropsis splendida Geitler (the promising alga were markedly enhanced by either increasing salt concentration or by nitrogen deficiency with maximum production of (26.8, 18.9 and 7.9 % respectively at nitrogen starvation condition.

    Ocho especies de algas (4 Rhodo, 1 cloro y 1 macroalgas phaeophycean, 1 cianobacteria y 1 microalga verde fueron utilizados para la producción de biodiesel utilizando dos sistemas de extracción con disolventes (hexano/éter (1:1, v/v y (Cloroformo / metanol (2:1, v/v. La evaluación bioquímica de las especies de algas se llevó a cabo mediante la estimación de los porcentajes de biomasa, de lípidos, de biodiesel y de sedimento (glicerina y pigmentos. El sistema extracción con el disolvente hexano/éter (1:1, v

  10. The alga Bryothamnion seaforthii contains carbohydrates with antinociceptive activity

    Directory of Open Access Journals (Sweden)

    L.A.P. Vieira

    2004-07-01

    Full Text Available Bryothamnion seaforthii, a red alga common to the Northeastern coast of Brazil, was used to prepare the protein fraction F0/60 by ammonium sulfate precipitation. The chromatography of F0/60 on DEAE-Sephadel column resulted in two lectin fractions, PI and PII, which have antinociceptive properties in rodents. We determined the antinociceptive activity of the PII fraction and of a carbohydrate-containing fraction (CF in mice. The CF was prepared from the dried algae, after digestion with 100 mM sodium acetate, pH 6.0, containing 5 mM cysteine, EDTA and 0.4% papain, at 60ºC. A 10% cetylpyridinium chloride was added to the filtrate, and the precipitate was dissolved with 2 M NaCl:ethanol (100:15, v/v followed by the carbohydrate precipitation with ethanol. The final precipitate, in acetone, was dried at 25ºC. The PII fraction markedly inhibited acetic acid-induced abdominal writhing after ip administration (control: 27.1 ± 2.20; PII 0.1 mg/kg: 5.5 ± 1.85; 1 mg/kg: 1.6 ± 0.72 writhes/20 min and after oral administration (control: 32.0 ± 3.32; PII 0.1 mg/kg: 13.1 ± 2.50; 1 mg/kg: 9.4 ± 3.96 writhes/20 min. PII was also effective against both phases of pain induced by 1% formalin (control, ip: 48.2 ± 2.40 and 27.7 ± 2.56 s; PII: 1 mg/kg, ip: 34.3 ± 5.13 and 5.6 ± 2.14 s; control, po: 44.5 ± 3.52 and 25.6 ± 2.39 s; PII 5 mg/kg, po: 26.5 ± 4.67 and 15.3 ± 3.54 s for the 1st and 2nd phases, respectively and in the hot-plate test. The CF (ip also displayed significant antinociceptive properties in all tests but at higher doses (1 and 5 mg/kg, ip and po. Thus, CF at the dose of 5 mg/kg significantly inhibited writhes (ip: 7.1 ± 2.47 and po: 14.5 ± 2.40 writhes/20 min as well as the 1st (po: 19.6 ± 1.74 s and 2nd (po: 7.1 ± 2.24 s phases of the formalin test compared to controls ip and po. The antinociceptive effects of both the PII and CF in the formalin and hot-plate tests were prevented at least partially by pretreatment with the

  11. Biological activity of two red algae, Gracilaria salicornia and Hypnea flagelliformis from Persian Gulf.

    Directory of Open Access Journals (Sweden)

    S Saeidnia

    2009-01-01

    Full Text Available Among marine organisms, algae are a large and diverse group of organisms from which a wide range of secondary metabolites have been isolated. A number of these compounds possess biological activity. In this study, we aim to evaluate the cytotoxic, antibacterial and antifungal activity of two red algae, Gracilaria salicornia and Hypnea flagelliformis, collected from Persian Gulf. Ethyl acetate extracts of both algae showed a potent cytotoxic effect against Artemia salina nauplii (LC50 = 3 and 4 μg.ml−1, respectively. Aqueous methanol (50% extracts were also effective. None of the methanol and aqueous methanol extracts of the algae showed antifungal and antibacterial activity against Staphylococcus aureus, Escherichia coli, Candida albicans and Aspergillus niger by the Broth-dilution method. Only the ethyl acetate extracts exhibited antibacterial activity (MIC = 2 μg.ml−1 on S. aureus. In conclusion, G. salicornia and H. flagelliformis could be a promising source of cytotoxic components.

  12. Study on contrast test of PPC pre-oxidation and coagulation for algae removal and deodorization

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The effect of treating algae-bearing water and induced odor by use of permanganate potassium composite (PPC) pre-oxidation was investigated, and was compared with the effect of treatments by pre-chlorination, permanganate potassium pre-oxidation and simple coagulation. The results showed that simple coagulation and pre-chlorination were less effective in removing algae and its odor, whereas PPC pre-oxidation was the most effective in algae removal and deodorization. Upon oxidation with PPC, the cells of Oscillatoria agardhic were inactivated and some intra-cellular and extra-cellular components were released into the water, which may help the coagulation by their bridging effect. The efficient removal of algae by PPC pre-oxidation is believed to be the joint contribution of several mechanisms.

  13. Characteristic and mechanism of inactivating algae with O3 and ClO2

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Both O3 and ClO2 have a high effect on inacti- vating-algae in source water with no forming THMs which do harm to human in producing drinking water, so they will be favorably substituted for Cl2. In order to make certain of the mechanism of inactivating algae with O3 and ClO2, the algal cell number change and its different characteristics of figures and structures in treated and untreated water have been studied by the microscopy and SEM and the mode of inactivating algae has been inferred. The results show that the mechanism of inactivating algae by O3 is not completely identical with that by ClO2. The actual reaction process and efficiency have been controlled by many factors, such as the different characteristics of oxidants and algal cells.

  14. Preliminary observations on the benthic marine algae of the Gorringe seabank (northeast Atlantic Ocean)

    Science.gov (United States)

    Tittley, Ian; da Silva Vaz Álvaro, Nuno Miguel; de Melo Azevedo Neto, Ana Isabel

    2014-06-01

    Examination of marine samples collected in 2006 from the Gettysburg and Ormonde seamounts on the Gorringe seabank southwest of Portugal has revealed 29 benthic Chlorophyta, Phaeophyceae (Ochrophyta), and Rhodophyta that were identified provisionally to genus and to species. Combining lists for the present and a previous expedition brings the total of algae thus far recorded to 48. The brown alga Zonaria tournefourtii and the red alga Cryptopleura ramosa were the most abundant species in the present collections. The kelp Laminaria ochroleuca was present only in the Gettysburg samples while Saccorhiza polyschides was observed only on the Ormonde seamount. Comparisons with the benthic marine algae recorded on seamounts in the mid-Atlantic Azores archipelago show features in common, notably kelp forests of L. ochroleuca at depths below 30 m and Z. tournefortii dominance in shallower waters.

  15. Method and apparatus for detecting phycocyanin-pigmented algae and bacteria from reflected light

    Science.gov (United States)

    Vincent, Robert (Inventor)

    2013-01-01

    The present invention relates to a method of detecting phycocyanin algae or bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  16. Bioactivity of marine organisms. Part 3. Screening of marine algae of Indian coast for biological activity

    Digital Repository Service at National Institute of Oceanography (India)

    Kamat, S.Y.; Wahidullah, S.; Naik, C.G.; DeSouza, L.; Jayasree, V.; Ambiye, V.; Bhakuni, D.S.; Goel, A.K.; Garg, H.S.; Srimal, R.C.

    Ethanolic extracts from Indian marine algae have been tested for anti-viral, anti-bacterial, anti-fungal, anti-fertility, hypoglycaemic and a wide range of pharmacological activities. Of 34 species investigated 17 appeared biologically active. Six...

  17. A new index to assess chemicals increasing the greenhouse effect based on their toxicity to algae.

    Science.gov (United States)

    Wang, Ting; Zhang, Xiaoxian; Tian, Dayong; Gao, Ya; Lin, Zhifen; Liu, Ying; Kong, Lingyun

    2015-11-01

    CO2, as the typical greenhouse gas causing the greenhouse effect, is a major global environmental problem and has attracted increasing attention from governments. Using algae to eliminate CO2, which has been proposed as an effective way to reduce the greenhouse effect in the past decades, can be disturbed by a growing number of artificial chemicals. Thus, seven types of chemicals and Selenastrum capricornutum (algae) were examined in this study, and the good consistency between the toxicity of artificial chemicals to algae and the disturbance of carbon fixation by the chemicals was revealed. This consistency showed that the disturbance of an increasing number of artificial chemicals to the carbon fixation of algae might be a "malware" worsening the global greenhouse effect. Therefore, this study proposes an original, promising index to assess the risk of deepening the greenhouse effect by artificial chemicals before they are produced and marketed.

  18. The effect of temporal variability in salinity on the invasive red alga Gracilaria vermiculophylla

    DEFF Research Database (Denmark)

    Nejrup, Lars Brammer; Pedersen, Morten Foldager

    2012-01-01

    become abundant in many shallow, soft-bottom estuaries. Salinity is important for the local and regional distribution of algae. The distribution of G. vermiculophylla in Europe suggests that it thrives well in hyposaline environments and that it may be more fit than some native algae under...... such conditions. Little, however, is known about the ecophysiology of G. vermiculophylla and it is therefore difficult to predict its spread and future distribution. Laboratory experiments with G. vermiculophylla showed that steady-state salinity above 15 psu was optimal for growth and that the growth rate...... was reduced at salinities below 15 psu. Variable salinity reduced the growth rate and larger oscillations were more stressful than small ones. Exposure to very low salinity (0–5 psu) was stressful for the alga and algae exposed to these low levels for 2–4 days were unable to recover fully. Gracilaria...

  19. Evidence for a photoprotective function for secondary carotenoids of snow algae

    Energy Technology Data Exchange (ETDEWEB)

    Bidigare, R.R.; Ondrusek, M.E. (Univ. of Hawaii, Honolulu, HI (United States)); Kennicutt, M.C. II (Geochemical Environmental Research Group, College Station, TX (United States)); Iturriaga, R. (Univ. of Southern California, Los Angeles, CA (United States)); Harvey, H.R. (Univ. of Maryland, Solomons, MD (United States)); Hoham, R.W. (Colgate Univ., Hamilton, NY (United States)); Macko, S.A. (Univ. of Virginia, Charlottesville, VA (United States))

    1993-08-01

    Snow algae occupy a unique habitat in high altitude and polar environments. These algae are often subject to extremes in nutrient availability, acidity, solar irradiance, desiccation, and ambient temperature. This report documents the accumulation of secondary carotenoids by snow algae in response to the availability of nitrogenous nutrients. Unusually large accumulations of astaxanthin esters in extra-chloroplastic lipid globules produce the characteristic red pigmentation typical of some snow algae (e.g., Chlamydomonas nivalis (Bauer) Wille). Consequently, these compounds greatly reduce the amount of light available for absorption by the light-harvesting pigment-protein complexes, thus potentially limiting photoinhibition and photodamage caused by intense solar radiation. The esterification of astaxanthin with fatty acids represents a possible mechanism by which this chromophore can be concentrated within cytoplasmic globules to maximize its photoprotective efficiency. 53 refs., 2 figs., 4 tabs.

  20. Numerical prediction of algae cell mixing feature in raceway ponds using particle tracing methods.

    Science.gov (United States)

    Ali, Haider; Cheema, Taqi A; Yoon, Ho-Sung; Do, Younghae; Park, Cheol W

    2015-02-01

    In the present study, a novel technique, which involves numerical computation of the mixing length of algae particles in raceway ponds, was used to evaluate the mixing process. A value of mixing length that is higher than the maximum streamwise distance (MSD) of algae cells indicates that the cells experienced an adequate turbulent mixing in the pond. A coupling methodology was adapted to map the pulsating effects of a 2D paddle wheel on a 3D raceway pond in this study. The turbulent mixing was examined based on the computations of mixing length, residence time, and algae cell distribution in the pond. The results revealed that the use of particle tracing methodology is an improved approach to define the mixing phenomenon more effectively. Moreover, the algae cell distribution aided in identifying the degree of mixing in terms of mixing length and residence time.

  1. Statistical significance of biomonitoring of marine algae for trace metal levels in a coral environment

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinath, A.; Muraleedharan, N.S.; Chandramohanakumar, N.; Jayalakshmy, K.V.

    the ability of algae to accumulate a particular metal from among the metals studied. To show the similarity between species and metal uptake, a group linkage clustering technique was used and the results were depicted using dendrogram. The marked similarities...

  2. LIPID BIOMARKER CHARACTERIZATION OF BLOOM-RELATED DINOFLAGELLATES AND OTHER EUKARYOTIC ALGAE

    Science.gov (United States)

    Marine eukaryotic algae synthesize an array of lipids of chemotaxonomic utility that are potentially valuable in characterizing phytoplankton communities. Sterols and photopigments characteristic of dinoflagellates are rarely found in other algal classes. Long chain (C28) highly ...

  3. NOTES ON INDONESIAN FRESHWATER ALGAE II*Ichthyodontum, a new desmid genus from Sumatra.

    Directory of Open Access Journals (Sweden)

    ARTHUR M. SCOTT

    1956-12-01

    Full Text Available Described and figured are Ichthyodontum, a new genus belongingto the desmidiaceous algae, with I.sachlanii, a new species with its newvariety parorthium, showing a peculiar bipolarity. From souther Sumatra.

  4. Algae biodiesel life cycle assessment using current commercial data.

    Science.gov (United States)

    Passell, Howard; Dhaliwal, Harnoor; Reno, Marissa; Wu, Ben; Ben Amotz, Ami; Ivry, Etai; Gay, Marcus; Czartoski, Tom; Laurin, Lise; Ayer, Nathan

    2013-11-15

    Autotrophic microalgae represent a potential feedstock for transportation fuels, but life cycle assessment (LCA) studies based on laboratory-scale or theoretical data have shown mixed results. We attempt to bridge the gap between laboratory-scale and larger scale biodiesel production by using cultivation and harvesting data from a commercial algae producer with ∼1000 m(2) production area (the base case), and compare that with a hypothetical scaled up facility of 101,000 m(2) (the future case). Extraction and separation data are from Solution Recovery Services, Inc. Conversion and combustion data are from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation Model (GREET). The LCA boundaries are defined as "pond-to-wheels". Environmental impacts are quantified as NER (energy in/energy out), global warming potential, photochemical oxidation potential, water depletion, particulate matter, and total NOx and SOx. The functional unit is 1 MJ of energy produced in a passenger car. Results for the base case and the future case show an NER of 33.4 and 1.37, respectively and GWP of 2.9 and 0.18 kg CO2-equivalent, respectively. In comparison, petroleum diesel and soy diesel show an NER of 0.18 and 0.80, respectively and GWP of 0.12 and 0.025, respectively. A critical feature in this work is the low algal productivity (3 g/m(2)/day) reported by the commercial producer, relative to the much higher productivities (20-30 g/m(2)/day) reported by other sources. Notable results include a sensitivity analysis showing that algae with an oil yield of 0.75 kg oil/kg dry biomass in the future case can bring the NER down to 0.64, more comparable with petroleum diesel and soy biodiesel. An important assumption in this work is that all processes are fully co-located and that no transport of intermediate or final products from processing stage to stage is required.

  5. Re-utilization of Industrial CO2 for Algae Production Using a Phase Change Material

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Brian

    2013-12-31

    This is the final report of a 36-month Phase II cooperative agreement. Under this project, Touchstone Research Laboratory (Touchstone) investigated the merits of incorporating a Phase Change Material (PCM) into an open-pond algae production system that can capture and re-use the CO2 from a coal-fired flue gas source located in Wooster, OH. The primary objective of the project was to design, construct, and operate a series of open algae ponds that accept a slipstream of flue gas from a coal-fired source and convert a significant portion of the CO2 to liquid biofuels, electricity, and specialty products, while demonstrating the merits of the PCM technology. Construction of the pilot facility and shakedown of the facility in Wooster, OH, was completed during the first two years, and the focus of the last year was on operations and the cultivation of algae. During this Phase II effort a large-scale algae concentration unit from OpenAlgae was installed and utilized to continuously harvest algae from indoor raceways. An Algae Lysing Unit and Oil Recovery Unit were also received and installed. Initial parameters for lysing nanochloropsis were tested. Conditions were established that showed the lysing operation was effective at killing the algae cells. Continuous harvesting activities yielded over 200 kg algae dry weight for Ponds 1, 2 and 4. Studies were conducted to determine the effect of anaerobic digestion effluent as a nutrient source and the resulting lipid productivity of the algae. Lipid content and total fatty acids were unaffected by culture system and nutrient source, indicating that open raceway ponds fed diluted anaerobic digestion effluent can obtain similar lipid productivities to open raceway ponds using commercial nutrients. Data were also collected with respect to the performance of the PCM material on the pilot-scale raceway ponds. Parameters such as evaporative water loss, temperature differences, and growth/productivity were tracked. The pond with the

  6. [Response of the algae Gymnodinium kovalevskii (Dinophyta) to exposure to synthetic detergents and distillation].

    Science.gov (United States)

    Aĭzdaĭcher, N A

    2000-01-01

    The effects of synthetic detergents and combined effects of synthetic detergents and water freshening on growth characteristics of the alga Gymnodinium kovalevskii (Dinophyta) were studied. Low concentrations of synthetic detergents (0.1 and 1.0 mg/l) stimulated the algal growth. Elevated concentrations inhibited cell division, affected their motility and induced morphological changes. Contamination with synthetic detergents adversely affected the adaptation plasticity of algae with respect to salinity.

  7. Effect of selenium on the lipids of two unicellular marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Gennity, J.M.

    1983-01-01

    The incorporation of selenium into the lipids of two unicellar marine algae has been investigated. Axenic cultures of the green algae Dunaliella primolecta and the red algae Porphyridium cruentum were grown in the presence of sublethal quantities of selenium (10 ppm) as selenite. Both algae were found to contain selenium bound to all purified lipids, except for saturated hydrocarbons. Of the lipids which contain selenium, carotenoid pigments show the greatest selenium concentration (..beta..-carotene: 1.3..mu..gSe/mg lipid; zeaxanthin: 1.1..mu..gSe/mg lipid) in both algae. P. cruentum contains about ten times as much lipid-associated selenium as D. primolecta, even though the lipids of both algae were very similar. This selenium has been shown to be incorporated non-metabolically into the lipid molecule. The lipid-associated selenium is probably non-covalently bound to the lipid molecule and may interact with double bonds. Selenite does not affect the lipid composition of D. primolecta, as compared with algae grown in the absence of added selenium. A selenium-induced 40% decrease in the cell content of eicosapentaenoic acid (20:5omega3) and 20% decrease in arachidonic acid (20:4omega6) in polar lipids (glycolipids plus phospholipids) was observed in P. cruentum. A 25% decrease in the chlorophyll a content of this red algae also occurred. The cell content of other fatty acids, phospholipids and glycolipids was unaltered by selenium. These results are consistent with a selenite-induced oxidation of P. cruentum lipids. Selenium is able to increase the antioxidant potential of algal cells. However, no in vivo selenium-induced protection of algal lipids from oxidation was apparent.

  8. Endolithic algae and micrite envelope formation in Bahamian oolites as revealed by scanning electron microscopy.

    Science.gov (United States)

    Margolis, S.; Rex, R. W.

    1971-01-01

    Examination of Holocene Bahamian ooelites by scanning electron and light microscopy has revealed the morphology and orientation of aragonite crystals in the lamellar ooelitic envelope, and their modification by the boring activities of endolithic algae. The voids produced by these algae are found in progressive stages of being lined and filled with precipitated microcrystalline aragonite, which is similar to the process of micrite envelope formation in molluscan and other skeletal carbonate grains.

  9. [Determination of 3, 4-benzopyrene in spiruline algae produced and treated by various procedures].

    Science.gov (United States)

    Bories, G; Tulliez, J

    1975-01-01

    Spirulina algae grow in highly salted natural lakes. Artificial cultivation in tanks with addition of carbon dioxide (natural gas, burned gases) has been studied in order to improve the biosynthesis. A possible 3, 4-benzopyrene (BaP) contamination must be then considered. Several BaP determinations have been performed in batches of algae from bath origins, prepared following different processes (filtration, spray, cylinder drying). BaP contents are very low (2 to 3 ppb) and comparable between batches.

  10. Coralline Algae from the Neoegne and Pleistocene Sequence of Mersa Alam, Red Sea, Egypt.

    OpenAIRE

    Khalifa, H; Boukhary, M. A.

    1982-01-01

    Ten speciecs of family Corallinaceae (Coralline Algae) are herein recorded and described for the first time from the stratigraphic sequence of Mersa Alam, Red Sea, Egypt. Of these, Amphiroa knolli, Jania johnsoni and Archaeolithothamnium alamensis are described as new. The studied sequence is subdivided according to its coralline algae and larger foraminiferal content into three biozones; which are from top to bottom: 3. Amphiroa knolli Zone, 2. Amphiroa prefragilissima Zone and 1. Borelis...

  11. Reviews and syntheses: Calculating the global contribution of coralline algae to total carbon burial

    Science.gov (United States)

    van der Heijden, L. H.; Kamenos, N. A.

    2015-11-01

    The ongoing increase in anthropogenic carbon dioxide (CO2) emissions is changing the global marine environment and is causing warming and acidification of the oceans. Reduction of CO2 to a sustainable level is required to avoid further marine change. Many studies investigate the potential of marine carbon sinks (e.g. seagrass) to mitigate anthropogenic emissions, however, information on storage by coralline algae and the beds they create is scant. Calcifying photosynthetic organisms, including coralline algae, can act as a CO2 sink via photosynthesis and CaCO3 dissolution and act as a CO2 source during respiration and CaCO3 production on short-term timescales. Long-term carbon storage potential might come from the accumulation of coralline algae deposits over geological timescales. Here, the carbon storage potential of coralline algae is assessed using meta-analysis of their global organic and inorganic carbon production and the processes involved in this metabolism. Net organic and inorganic production were estimated at 330 g C m-2 yr-1 and 900 g CaCO3 m-2 yr-1 respectively giving global organic/inorganic C production of 0.7/1.8 × 109 t C yr-1. Calcium carbonate production by free-living/crustose coralline algae (CCA) corresponded to a sediment accretion of 70/450 mm kyr-1. Using this potential carbon storage for coralline algae, the global production of free-living algae/CCA was 0.4/1.2 × 109 t C yr-1 suggesting a total potential carbon sink of 1.6 × 109 tonnes per year. Coralline algae therefore have production rates similar to mangroves, salt marshes and seagrasses representing an as yet unquantified but significant carbon store, however, further empirical investigations are needed to determine the dynamics and stability of that store.

  12. Drifting algae and fish: Implications of tropical Sargassum invasion due to ocean warming in western Japan

    Science.gov (United States)

    Yamasaki, Mami; Aono, Mikina; Ogawa, Naoto; Tanaka, Koichiro; Imoto, Zenji; Nakamura, Yohei

    2014-06-01

    Evidence is accumulating that the invasion and extinction of habitat-forming seaweed species alters coastal community structure and ecological services, but their effects on the pelagic environment have been largely ignored. Thus, we examined the seasonal occurrence patterns of indigenous temperate and invasive tropical drifting algae and associated fish species every month for 2 years (2009-2011) in western Japan (Tosa Bay), where a rapid shift from temperate to tropical Sargassum species has been occurring in the coastal area since the late 1980s due to rising seawater temperatures. Of the 19 Sargassum species (31.6%) in drifting algae, we found that six were tropical species, whereas a study in the early 1980s found only one tropical species among 12 species (8.3%), thereby suggesting an increase in the proportion of tropical Sargassum species in drifting algae during the last 30 years. Drifting temperate algae were abundantly present from late winter to summer, whereas tropical algal clumps occurred primarily during summer. In the warm season, fish assemblages did not differ significantly between drifting temperate and tropical algae, suggesting the low host-algal specificity of most fishes. We also found that yellowtail juveniles frequently aggregated with drifting temperate algae from late winter to spring when drifting tropical algae were unavailable. Local fishermen collect these juveniles for use as aquaculture seed stock; therefore, the occurrence of drifting temperate algae in early spring is important for local fisheries. These results suggest that the further extinction of temperate Sargassum spp. may have negative impacts on the pelagic ecosystem and associated regional fisheries.

  13. Astaxanthin Accumulation in the Green Alga Haematococcus pluvialis: Effects of Cultivation Parameters

    Institute of Scientific and Technical Information of China (English)

    Ping He; James Duncan; James Barber

    2007-01-01

    The green alga, Haematococcus pluvialis Flotow is used as a source of the ketocarotenoid astaxanthin for application in fish aquaculture, pharmaceutical and cosmetic industries. Cells of the green alga were induced by the application of different light and starvation conditions to evaluate the effect in astaxanthin accumulate. The condiphosphate starvation. The results show that stresses applied in culture, which interfere with cell division, trigger the accumulation of astaxanthin. Notably, sulfur starvation results in a massive accumulation of this commercially important carotenoid.

  14. Epilithic algae from caves of the Krakowsko-Częstochowska Upland (Southern Poland

    Directory of Open Access Journals (Sweden)

    Joanna Czerwik-Marcinkowska

    2011-01-01

    Full Text Available This paper describes the first study of algae assemblages in 20 caves in the Krakowsko-Częstochowska Upland (Southern Poland, in the period between 2005-2006. The investigations showed mostly on epilithic algae and their subaeric habitats (rock faces within caves and walls at cave entrances. The morphological and cytological variability of algae were studied in fresh samples, in cultures grown on agar plates and in SPURR preparations. A total of 43 algae species was identified, mostly epilithic species and tolerant of low light intensities. The largest group was formed by representatives of the division Chlorophyta (24 species, and then the division Chrysophyta (Heterokontophyta - 17 species, with 9 species belonging to the class Bacillariophyceae, 7 species - Xanthophyceae and 1 species representing the class Eustigmatophyceae. Dinophyta (2 species constituted the last and the smallest group. Among the collected algae, the following species deserve special attention: Thelesphaera alpina, Bracteacoccus minor, Trachychloron simplex, Tetracystis intermedia and T. cf. isobilateralis. The last species was not earlier found in Europe. Identification of species was greatly aided by examination of cell ultrastructure, which provided an array of further features, increasing chances of correct species identification. Furthermore, the studies focused that algae, although usually remaining under dominance of cyanobacteria, excellently differentiate this special area and even enrich it.

  15. INTERACTIONS BETWEEN OCEAN ACIDIFICATION AND WARMING ON THE MORTALITY AND DISSOLUTION OF CORALLINE ALGAE(1).

    Science.gov (United States)

    Diaz-Pulido, Guillermo; Anthony, Kenneth R N; Kline, David I; Dove, Sophie; Hoegh-Guldberg, Ove

    2012-02-01

    Coralline algae are among the most sensitive calcifying organisms to ocean acidification as a result of increased atmospheric carbon dioxide (pCO2 ). Little is known, however, about the combined impacts of increased pCO2 , ocean acidification, and sea surface temperature on tissue mortality and skeletal dissolution of coralline algae. To address this issue, we conducted factorial manipulative experiments of elevated CO2 and temperature and examined the consequences on tissue survival and skeletal dissolution of the crustose coralline alga (CCA) Porolithon (=Hydrolithon) onkodes (Heydr.) Foslie (Corallinaceae, Rhodophyta) on the southern Great Barrier Reef (GBR), Australia. We observed that warming amplified the negative effects of high pCO2 on the health of the algae: rates of advanced partial mortality of CCA increased from ocean acidification under warm conditions, suggesting that previous experiments focused on ocean acidification alone have underestimated the impact of future conditions on coralline algae. Given the central role that coralline algae play within coral reefs, these conclusions have serious ramifications for the integrity of coral-reef ecosystems.

  16. The Selective Use of Hypochlorite to Prevent Pond Crashes for Algae-Biofuel Production.

    Science.gov (United States)

    Park, Sichoon; Van Ginkel, Steven W; Pradeep, Priya; Igou, Thomas; Yi, Christine; Snell, Terry; Chen, Yongsheng

    2016-01-01

    Although algae-biofuels have many advantages including high areal productivity, algae can be preyed upon by amoebas, protozoans, ciliates, and rotifers, particularly in open pond systems. Thus, these higher organisms need to be controlled. In this study, Chlorella kessleri was used as the algal culture and Brachionus calyciflorus as the source of predation. The effect of sodium hypochlorite (bleach) was tested with the goal of totally inhibiting the rotifer while causing minor inhibition to the alga. The 24-hr LC(50) for B. calyciflorus in spring water was 0.198 mg Cl/L while the 24-hr LC(50) for C. kessleri was 0.321 mg Cl/L. However, chlorine dissipates rapidly as the algae serves as reductant. Results showed a chlorine dosage between 0.45 to 0.6 mg Cl/L and a dosing interval of two hours created the necessary chlorine concentrations to inhibit predation while letting the algae grow; thus giving algae farmers a tool to prevent pond crashes.

  17. The cell walls of green algae: a journey through evolution and diversity

    Directory of Open Access Journals (Sweden)

    David eDomozych

    2012-05-01

    Full Text Available The green algae represent a large group of morphologically diverse photosynthetic eukaryotes that occupy virtually every photic habitat on the planet. The extracellular coverings of green algae including cell walls are also diverse. A recent surge of research in green algal cell walls fueled by new emerging technologies has revealed new and critical insight concerning these coverings. For example, the late divergent taxa of the Charophycean Green Algae possess cell walls containing assemblages of polymers with notable similarity to the cellulose, pectins, hemicelluloses, arabinogalactan proteins, extensin and lignin present in embryophyte walls. Ulvophycean seaweeds have cell wall components whose most abundant fibrillar constituents may change from cellulose to β-mannans to β-xylans and during different life cycle phases. Likewise, these algae produce complex sulfated polysaccharides, arabinogalactan proteins and extensin. Chlorophycean green algae produce a wide array of walls ranging from cellulose-pectin complexes to ones made of hydroxyproline-rich glycoproteins. Larger and more detailed surveys of the green algal taxa including incorporation of emerging genomic and transcriptomic data are required in order to more fully resolve evolutionary trends within the green algae and in relationship with higher plants as well as potential applications of wall components in the food and pharmaceutical industries.

  18. SOME FACTORS IN THE COMPETITION OR ANTAGONISM AMONG BACTERIA, ALGAE, AND AQUATIC WEEDS.

    Science.gov (United States)

    Filzgerald, G P

    1969-12-01

    Field observations of changes in the populations of aquatic weeds and phytoplankton have confirmed that aquatic weeds have antagonistic activity toward phytoplankton. Nutritional studies in the laboratory indicate that cultures of the aquatic weeds, Myriophyllum sp., Ceratophyllum sp., and duckweed (Lemma minor L.); liquid cultures of barley (Hordeum vulgare L., Dickson variety); and cultures of the filamentous green algae, Cladophora sp. and Pithophora oedogonium (Mont.) Withrock, will remain relatively free of epiphytes or competing phytoplankton if the cultures are nitrogen-limited. Field observations of Cladophora sp. have confirmed that the growth of epiphytes on the Cladophora is related to conditions of surplus available nitrogen compounds. It is proposed that this antagonistic activity may be due to a "nitrogen sink" effect in which the aquatic weeds or filamentous green algae prevent the growth of contaminating algae by competition for the limited nitrogen compounds available. However, the presence of bacteria-sized organisms which have selective toxicity to certain algae indicates that perhaps multiple factors exist. Discussed are the ecological implications of associations of certain algae with bacteria that have selective toxicities for other species of algae under certain environmental conditions such as nitrogen-limited growth.

  19. Predicting the risk of toxic blooms of golden alga from cell abundance and environmental covariates

    Science.gov (United States)

    Patino, Reynaldo; VanLandeghem, Matthew M.; Denny, Shawn

    2016-01-01

    Golden alga (Prymnesium parvum) is a toxic haptophyte that has caused considerable ecological damage to marine and inland aquatic ecosystems worldwide. Studies focused primarily on laboratory cultures have indicated that toxicity is poorly correlated with the abundance of golden alga cells. This relationship, however, has not been rigorously evaluated in the field where environmental conditions are much different. The ability to predict toxicity using readily measured environmental variables and golden alga abundance would allow managers rapid assessments of ichthyotoxicity potential without laboratory bioassay confirmation, which requires additional resources to accomplish. To assess the potential utility of these relationships, several a priori models relating lethal levels of golden alga ichthyotoxicity to golden alga abundance and environmental covariates were constructed. Model parameters were estimated using archived data from four river basins in Texas and New Mexico (Colorado, Brazos, Red, Pecos). Model predictive ability was quantified using cross-validation, sensitivity, and specificity, and the relative ranking of environmental covariate models was determined by Akaike Information Criterion values and Akaike weights. Overall, abundance was a generally good predictor of ichthyotoxicity as cross validation of golden alga abundance-only models ranged from ∼ 80% to ∼ 90% (leave-one-out cross-validation). Environmental covariates improved predictions, especially the ability to predict lethally toxic events (i.e., increased sensitivity), and top-ranked environmental covariate models differed among the four basins. These associations may be useful for monitoring as well as understanding the abiotic factors that influence toxicity during blooms.

  20. Transcriptome-wide evolutionary analysis on essential brown algae (Phaeophyceae) in China

    Institute of Scientific and Technical Information of China (English)

    SUN Jing; LIU Tao; YU Jun; WANG Liang; WU Shuangxiu; WANG Xumin; XIAO Jingfa; CHI Shan; LIU Cui; REN Lufeng; ZHAO Yuhui

    2014-01-01

    Brown algae (Chromista, Ochrophyta, Phaeophyceae) are a large group of multicellular algae that play im-portant roles in the ocean's ecosystem and biodiversity. However, poor molecular bases for studying their phylogenetic evolutions and novel metabolic characteristics have hampered progress in the field. In this study, we sequenced the de novo transcriptome of 18 major species of brown algae in China, covering six orders and seven families, using the high-throughput sequencing platform Illumina HiSeq 2000. From the transcriptome data of these 18 species and publicly available genome data of Ectocarpus siliculosus and Phaeodactylum tricornutum, we identified 108 nuclear-generated orthologous genes and clarified the phy-logenetic relationships among these brown algae based on a multigene method. These brown algae could be separated into two clades:Clade Ishigeales-Dictyotales and Clade Ectocarpales-Laminariales-Desmares-tiale-Fucales. The former was at the base of the phylogenetic tree, indicating its early divergence, while the latter was divided into two branches, with Order Fucales diverging from Orders Ectocarpales, Laminariales, and Desmarestiale. In our analysis of taxonomy-contentious species, Sargassum fusiforme and Saccharina sculpera were found to be closely related to genera Sargassum and Saccharina, respectively, while Petalonia fascia showed possible relation to genus Scytosiphon. The study provided molecular evidence for the phylo-genetic taxonomy of brown algae.

  1. FRESH-WATER GREEN ALGAE (CHLOROPHYTA AS A NATURAL PIGMENT FOR MOJOSARI DUCKS

    Directory of Open Access Journals (Sweden)

    B. Indarsih

    2015-09-01

    Full Text Available An experiment in a completely randomize design was undertaken to study the use of fresh-watergreen algae as a yolk coloring agent in Mojosari ducks during a laying period on productiveperformance and egg quality from 36 to 44 wk of age. A total of 80 thirty-six wk–old laying ducks weredivided into four dietary treatments and each of four replicates with 5 birds. Diets were formulated witha commercial concentrate, rice bran and yellow corn (2:4:4 according to a commercial standard diet asa control, and three other dietary treatments with 2, 4 or 8% of green algae were included. Fresh watergreen algae had a significant effect on the feed uptake, egg production, and feed conversion ratio (FCR(p<0.05. Egg production and FCR improved at added 2 and 4% green algae. No differences wereobserved in egg yolk index, albumen index, Haugh Unit, and egg shell thickness (P>0.05 except eggyolk color. The yolk color increased within 7 days after feeding with the test diets. The present studyindicated that fresh-water green algae could be used as a natural coloring agent in laying ducks and at8% of green algae showed the highest score of (Roche Yellow Color-15.

  2. Growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu, China

    Institute of Scientific and Technical Information of China (English)

    Yuhong Jia; Johnson Dan; Min Zhang; Fanxiang Kong

    2013-01-01

    Three treatments,sediment plus lake water (S+W),sterilized sediment plus lake water (SS+W),and sediment plus filtered lake water (S+FW),were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment.The results showed that in the water column,biomass of all algae increased in all treatments when recruitment was initiated,whereas this tendency differed among treatments with further increment of temperature.The process of algal growth consisted of two stages:Stage Ⅰ,the onset of recruitment and Stage Ⅱ,the subsequent growth of algae.Compared with S+W,in Stage Ⅰ,SS+W significantly increased the biomass of cyanophytes by 178.70%,and decreased the biomass of non-cyanophytes by 43.40%; In Stage Ⅱ,SS+W notably stimulated the growth of all algae,thus incurring the occurrence of phytoplankton bloom.Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS+W,which resulted from the releasing of nutrients from sediment.These results suggest that algal growth in Stage Ⅱ and algal inocula in the water column can be important factors for the formation of phytoplankton bloom.In addition,possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.

  3. The blue water footprint and land use of biofuels from algae

    Science.gov (United States)

    Gerbens-Leenes, P. W.; Xu, L.; Vries, G. J.; Hoekstra, A. Y.

    2014-11-01

    Biofuels from microalgae are potentially important sources of liquid renewable energy. Algae are not yet produced on a large scale, but research shows promising results. This study assesses the blue water footprint (WF) and land use of algae-based biofuels. It combines the WF concept with an energy balance approach to determine the blue WF of net energy. The study considers open ponds and closed photobioreactors (PBRs). All systems have a positive energy balance, with output-input ratios ranging between 1.13 and 1.98. This study shows that the WF of algae-based biofuels lies between 8 and 193 m3/GJ net energy provided. The land use of microalgal biofuels ranges from 20 to 200 m2/GJ net energy. For a scenario in which algae-based biofuels provide 3.5% of the transportation fuels in the European Union in 2030, the system with the highest land productivity needs 17,000 km2 to produce the 850 PJ/yr. Producing all algae-based biofuels through the system with the highest water productivity would lead to a blue WF of 7 Gm3/yr, which is equivalent to 15% of the present blue WF in the EU28. A transition to algae-based transportation fuels will substantially increase competition over water and land resources.

  4. Time course transcriptome changes in Shewanella algae in response to salt stress.

    Directory of Open Access Journals (Sweden)

    Xiuping Fu

    Full Text Available Shewanella algae, which produces tetrodotoxin and exists in various seafoods, can cause human diseases, such as spondylodiscitis and bloody diarrhea. In the present study, we focused on the temporal, dynamic process in salt-stressed S. algae by monitoring the gene transcript levels at different time points after high salt exposure. Transcript changes in amino acid metabolism, carbohydrate metabolism, energy metabolism, membrane transport, regulatory functions, and cellular signaling were found to be important for the high salt response in S. algae. The most common strategies used by bacteria to survive and grow in high salt environments, such as Na+ efflux, K+ uptake, glutamate transport and biosynthesis, and the accumulation of compatible solutes, were also observed in S. algae. In particular, genes involved in peptidoglycan biosynthesis and DNA repair were highly and steadily up-regulated, accompanied by rapid and instantaneous enhancement of the transcription of large- and small-ribosome subunits, which suggested that the structural changes in the cell wall and some stressful responses occurred in S. algae. Furthermore, the transcription of genes involved in the tricarboxylic acid (TCA cycle and the glycolytic pathway was decreased, whereas the transcription of genes involved in anaerobic respiration was increased. These results, demonstrating the multi-pathway reactions of S. algae in response to salt stress, increase our understanding of the microbial stress response mechanisms.

  5. Rapid Evolution of microRNA Loci in the Brown Algae

    Science.gov (United States)

    Liu, Fuli; Duan, Delin; Bourdareau, Simon; Lipinska, Agnieszka P.; Coelho, Susana M.; Tarver, James E.

    2017-01-01

    Stringent searches for microRNAs (miRNAs) have so far only identified these molecules in animals, land plants, chlorophyte green algae, slime molds and brown algae. The identification of miRNAs in brown algae was based on the analysis of a single species, the filamentous brown alga Ectocarpus sp. Here, we have used deep sequencing of small RNAs and a recently published genome sequence to identify miRNAs in a second brown alga, the kelp Saccharina japonica. S. japonica possesses a large number of miRNAs (117) and these miRNAs are highly diverse, falling into 98 different families. Surprisingly, none of the S. japonica miRNAs share significant sequence similarity with the Ectocarpus sp. miRNAs. However, the miRNA repertoires of the two species share a number of structural and genomic features indicating that they were generated by similar evolutionary processes and therefore probably evolved within the context of a common, ancestral miRNA system. This lack of sequence similarity suggests that miRNAs evolve rapidly in the brown algae (the two species are separated by ∼95 Myr of evolution). The sets of predicted targets of miRNAs in the two species were also very different suggesting that the divergence of the miRNAs may have had significant consequences for miRNA function. PMID:28338896

  6. Floristic account of the marine benthic algae from Jarvis Island and Kingman Reef, Line Islands, Central Pacific

    Directory of Open Access Journals (Sweden)

    Vroom, P.S.

    2012-05-01

    Full Text Available The marine benthic algae from Jarvis Island and Kingman Reef were identified from collections obtained from the Whippoorwill Expedition in 1924, the Itasca Expedition in 1935, the U.S. Coast Guard Cutter Taney in 1938, the Smithsonian Institution’s Pacific Ocean Biological Survey Program in 1964 and the U.S. National Oceanic and Atmospheric Administration’s Reef Assessment and Monitoring Program (RAMP in 2000, 2001, 2002, 2004 and 2006. A total of 124 species, representing 8 Cyanobacteria (blue-green algae, 82 Rhodophyta (red algae, 6 Heterokontophyta (brown algae and 28 Chlorophyta (green algae, are reported from both islands. Seventy-nine and 95 species of marine benthic algae are recorded from Jarvis Island and Kingman Reef, respectively. Of the 124 species, 77 species or 62% (4 blue-green algae, 57 red algae, 2 brown algae and 14 green algae have never before been reported from the 11 remote reefs, atolls and low islands comprising the Line Islands in the Central Pacific.

  7. Iron encrustations on filamentous algae colonized by Gallionella-related bacteria in a metal-polluted freshwater stream

    Science.gov (United States)

    Mori, J. F.; Neu, T. R.; Lu, S.; Händel, M.; Totsche, K. U.; Küsel, K.

    2015-09-01

    Filamentous macroscopic algae were observed in slightly acidic to circumneutral (pH 5.9-6.5), metal-rich stream water that leaked out from a former uranium mining district (Ronneburg, Germany). These algae differed in color and morphology and were encrusted with Fe-deposits. To elucidate their potential interaction with Fe(II)-oxidizing bacteria (FeOB), we collected algal samples at three time points during summer 2013 and studied the algae-bacteria-mineral compositions via confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, and a 16S and 18S rRNA gene-based bacterial and algae community analysis. Surprisingly, sequencing analysis of 18S rRNA gene regions of green and brown algae revealed high homologies with the freshwater algae Tribonema (99.9-100 %). CLSM imaging indicated a loss of active chloroplasts in the algae cells, which may be responsible for the change in color in gene-targeted studies revealed that Gallionella-related FeOB dominated the bacterial RNA and DNA communities (70-97 and 63-96 %, respectively), suggesting their capacity to compete with the abiotic Fe-oxidation under the putative oxygen-saturated conditions that occur in association with photosynthetic algae. Quantitative PCR (polymerase chain reaction) revealed even higher Gallionella-related 16S rRNA gene copy numbers on the surface of green algae compared to the brown algae. The latter harbored a higher microbial diversity, including some putative predators of algae. A loss of chloroplasts in the brown algae could have led to lower photosynthetic activities and reduced EPS production, which is known to affect predator colonization. Collectively, our results suggest the coexistence of oxygen-generating algae Tribonema sp. and strictly microaerophilic neutrophilic FeOB in a heavy metal-rich environment.

  8. Plant based phosphorus recovery from wastewater via algae and macrophytes.

    Science.gov (United States)

    Shilton, Andrew N; Powell, Nicola; Guieysse, Benoit

    2012-12-01

    At present, resource recovery by irrigation of wastewater to plants is usually driven by the value of the water resource rather than phosphorus recovery. Expanded irrigation for increased phosphorus recovery may be expected as the scarcity and price of phosphorus increases, but providing the necessary treatment, storage and conveyance comes at significant expense. An alternative to taking the wastewater to the plants is instead to take the plants to the wastewater. Algal ponds and macrophyte wetlands are already in widespread use for wastewater treatment and if harvested, would require less than one-tenth of the area to recover phosphorus compared to terrestrial crops/pastures. This area could be further decreased if the phosphorus content of the macrophytes and algae biomass was tripled from 1% to 3% via luxury uptake. While this and many other opportunities for plant based recovery of phosphorus exist, e.g. offshore cultivation, much of this technology development is still in its infancy. Research that enhances our understanding of how to maximise phosphorus uptake and harvest yields; and further add value to the biomass for reuse would see the recovery of phosphorus via plants become an important solution in the future.

  9. Sesquiterpenes from the Brazilian Red Alga Laurencia dendroidea J. Agardh

    Directory of Open Access Journals (Sweden)

    Fernanda Lacerda da Silva Machado

    2014-03-01

    Full Text Available Two new chamigrane sesquiterpenes 1–2 and three known compounds 3–5 were isolated from a lipophilic extract of the red alga Laurencia dendroidea collected from the Southeastern Brazilian coast. Dendroidone (1 and dendroidiol (2 were isolated from samples collected at Biscaia Inlet, Angra dos Reis, Rio de Janeiro and at Manguinhos Beach, Serra, Espírito Santo, respectively. Debromoelatol (3, obtusane (4 and (1S*,2S*,3S*,5S*,8S*,9S*-2,3,5,9-tetramethyltricyclo[6.3.0.01.5]undecan-2-ol (5 were obtained from specimens collected at Vermelha Beach, Parati, Rio de Janeiro. The structures of new compounds were elucidated by extensive NMR (1H-, 13C-, COSY, HSQC, HMBC and NOESY and high resolution mass spectrometry analysis. Additionally, the absolute configuration of compound 2 was assigned by X-ray analysis. Full spectroscopic data is described for the first time for compound 3. Anti-inflammatory and antimycobacterial activities of compounds 2–5 were evaluated. Compounds 3–5 inhibited the release of inflammatory mediator NO while TNF-α levels were only affected by 3. All compounds tested displayed moderate antimycobacterial action.

  10. Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics

    Energy Technology Data Exchange (ETDEWEB)

    Gobler, C J; Grigoriev, I V; Berry, D L; Dyhrman, S T; Wilhelm, S W; Salamov, A; Lobanov, A V; Zhang, Y; Collier, J L; Wurch, L L; Kustka, A B; Dill, B D; Shah, M; VerBerkomes, N C; Kuo, A; Terry, A; Pangilinan, J; Lindquist, E A; Lucas, S; Paulsen, I; Hattenrath-Lehmann, T K; Talmage, S; Walker, E A; Koch, F; Burson, A M; Marcoval, M A; Tang, Y; LeCleir, G R; Coyne, K J; Berg, G M; Bertrand, E M; Saito, M A; Gladyshev, V N

    2011-03-02

    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements demonstrated that the harmful alga Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the first HAB genome (A. anophagefferens) and compared its gene complement to those of six competing phytoplankton species identified via metaproteomics. Using an ecogenomic approach, we specifically focused on the gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 mbp) and more genes involved in light harvesting, organic carbon and nitrogen utilization, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus has facilitated the proliferation of this and potentially other HABs.

  11. Evidence for the occurrence of photorespiration in synurophyte algae.

    Science.gov (United States)

    Bhatti, Shabana; Colman, Brian

    2011-09-01

    The fluxes of CO(2) and oxygen during photosynthesis by cell suspensions of Tessellaria volvocina and Mallomonas papillosa were monitored mass spectrometrically. There was no rapid uptake of CO(2,) only a slow drawdown to compensation concentrations of 26 μM for T. volvocina and 18 μM for M. papillosa, when O(2) evolution ceased, indicating a lack of active bicarbonate uptake by the cells. Darkening of the cells after a period of photosynthesis did not cause rapid release of CO(2), indicating the absence of an intracellular inorganic carbon pool. However, upon darkening a brief burst of CO(2) was observed similar to the post-illumination burst characteristic of C(3) higher plants. Treatment of the cells of both species with the membrane-permeable carbonic anhydrase inhibitor ethoxyzolamide had no adverse effect on photosynthetic rate, but stimulated the dark CO(2) burst indicating the dark oxidation of a compound formed in the light. In the absence of any active accumulation of inorganic carbon photosynthesis in these species should be inhibited by O(2). This was investigated in four synurophyte species T. volvocina, M. papillosa, Synura petersenii, and Synura uvella: photosynthetic O(2) evolution rates in all four algae, measured by O(2) electrode, were significantly higher (40-50%) in media at low O(2) (4%) than in air-equilibrated (21% O(2)) media, indicating an O(2) inhibition of photosynthesis (Warburg effect) and thus the occurrence of photorespiration in these species.

  12. Factors influencing methane fermentation of micro-algae

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P.H.

    1987-01-01

    The study included both treatment of harvested algae prior to the admission to the fermentation reactor and operational variables within the fermentation reactor. In the case of pretreatment best conversion efficiency was attained with temperature of 100/sup 0/C for 8 hours at a concentration of 3.7% solid and zero NaOH. A mathematical model of the process was then constructed to predict efficiency as a function of all levels of these variables. For digestion conditions the best efficiency was attained at pH 7.0 to 8.1, volatile acid concentration under 500 mg/1 as acetic acid, alkalinity at 3000 to 8000 mg/1 as CaCo/sub 3/, C/N ratio of 30, mixing speed of 100 rpm, retention time of 30 days, feed concentration of 3.5% and temperature of 40/sup 0/C. Greatest gas yield was attained with Dunaliella species and least with Euglena viridis. Based on these data and the mathematical model a computer simulation model was designed to predict the combined influence on efficiency of fermentation on pretreatment time, pretreatment temperature, pretreatment concentration, mixing speed, digestion temperature, feeding concentration, and retention time.

  13. An Improved Method for Karyotype Analyses of Marine Algae

    Institute of Scientific and Technical Information of China (English)

    WANG Juan; DAI Jixun

    2008-01-01

    Modified carbol fuchsin staining method was successfully introduced into the karyotype analyses of marine algae, in-cluding Porphyra, Undaria pinnatifida and Laminaria japonica. Haploid chromosomes were numbered clearly in the vegetative, spermatangial and conchosporangial cells of P. haitanensis and P. yezoensis. Diploid chromosomes were observed and numbered in immature conchosporangial cells of P. haitanensis and P. yezoensis. Pit-connections of Porphyra were also clearly demonstrated. Prophase chromosomes of conchocelis cells were also clearly stained with modified carbol fuchsin. One molar per liter hydrochloric hydrolysis at 60℃ for 7-8min is necessary for getting transparent cytoplasm for conchosporangial karyotype analysis of Porphyra. Staining effects of the three methods using iron alum acetocarmine, aceto-iron-haematoxylin-chloral hydrate and modified carbol fuchsin were compared on the vegetative, sperrnatangial and conchosporangial cells of Porphyra and the gametophytes of U. pinnati-fida and L. japonica. Among the three methods, the modified carbol fuchsin method gave the best result of deep staining and good contrast between nucleus and cytoplasm.

  14. [Food value of spiruline algae for the laying hen].

    Science.gov (United States)

    Blum, J C; Guillaumin, S; Calet, C

    1975-01-01

    The three diets (composition in table I) were isonitrogenous (16,4 p. 100 crude protein), similar in their content of lysine and sulfur amino acids, but with different levels of spiruline algae : 0 (control); 7.5 or 15 p. 100. Each diet was used for the feeding of 48 hybrid pullets of medium size during a 24-week test period (32 to 56 weeks). Egg production (table II) was slightly better (47.1 g/hen/day) with 7.5 p. 100 of spirulines, compared to the control (45.3 g/hen/day), the difference being significant (P less than 0.01). With 15 p. 100 of spirulines egg production was similar to that observed in the control, but the average egg weight was reduced (58.5 vs 60.5 g) as a result of a lower albumen content. The colour of the egg yolk (table IV) was very light in the controls, but was a deep orange (above the maximum in the Roch scale) with 7.5 or 15 p. 100 of spirulines in the laying hen diet. The diet consumption, feed conversion and live weight variations (table III) show that the energy level is no higher in laying hens (about 2 500 kcal M.E./kg spirulines) than in the broiler.

  15. Modeling the dynamic modulation of light energy in photosynthetic algae.

    Science.gov (United States)

    Papadakis, Ioannis A; Kotzabasis, Kiriakos; Lika, Konstadia

    2012-05-01

    An integrated cell-based dynamic mathematical model that take into account the role of the photon absorbing process, the partition of excitation energy, and the photoinactivation and repair of photosynthetic units, under variable light and dissolved inorganic carbon (DIC) availability is proposed. The modeling of the photon energy absorption and the energy dissipation is based on the photoadaptive changes of the underlying mechanisms. The partition of the excitation energy is based on the relative availability of light and DIC to the cell. The modeling of the photoinactivation process is based on the common aspect that it occurs under any light intensity and the modeling of the repair process is based on the evidence that it is controlled by chloroplast and nuclear-encoded enzymes. The present model links the absorption of photons and the partitioning of excitation energy to the linear electron flow and other quenchers with chlorophyll fluorescence emission parameters, and the number of the functional photosynthetic units with the photosynthetic oxygen production rate. The energy allocation to the LEF increases as DIC availability increases and/or light intensity decreases. The rate of rejected energy increases with light intensity and with DIC availability. The resulting rate coefficient of photoinactivation increases as light intensity and/or as DIC concentration increases. We test the model against chlorophyll fluorescence induction and photosynthetic oxygen production rate measurements, obtained from cultures of the unicellular green alga Scenedesmus obliquus, and find a very close quantitative and qualitative correspondence between predictions and data.

  16. Heavy metal accumulation by carrageenan and agar producing algae

    Energy Technology Data Exchange (ETDEWEB)

    Burdin, K.S. [Moscow State Univ. (Russian Federation). Faculty of Biology; Bird, K.T. [North Carolina Univ., Wilmington, NC (United States). Center for Marine Science Research

    1994-09-01

    The accumulation of six heavy metals Cu, Cd, Ni, Zn, Mn and Pb was measured in living and lzophilized algal thalli. The agar producing algae were Gracilaria tikvahiae and Gelidium pusillum. The carrageenan producing macroalgae were Agardhiella subulata and the gametophyte and tetrasporophyte phases of Chondrus crispus. These produce primarily iota, kappa and lambda carrageenans, respectively. At heavy metal concentrations of 0.5 mg L{sup -1}, living thalli of Gracilaria tikvahiae generally showed the greatest amount of accumulation of the 6 heavy metals tested. The accumulation of Pb was greater in the living thalli of all four species than in the lyophilized thalli. Except for Agardhiella subulata, lyophilized thalli showed greater accumulation of Ni, Cu and Zn. There was no difference in heavy metal accumulation between living and lyophilized thalli in the accumulation of Cd. Manganese showed no accumulation at the tested concentration. There did not appear to be a relationship between algal hydrocolloid characteristics and the amounts of heavy metals accumulated. (orig.)

  17. Combined toxicity of pesticide mixtures on green algae and photobacteria.

    Science.gov (United States)

    Liu, Shu-Shen; Wang, Cheng-Lin; Zhang, Jin; Zhu, Xiang-Wei; Li, Wei-Ying

    2013-09-01

    Different organisms have diverse responses to the same chemicals or mixtures. In this paper, we selected the green algae Chlorella pyrenoidosa (C. pyrenoidosa) and photobacteria Vibrio qinghaiensis sp.-Q67 (V. qinghaiensis) as target organisms and determined the toxicities of six pesticides, including three herbicides (simetryn, bromacil and hexazinone), two fungicides (dodine and metalaxyl) and one insecticide (propoxur), and their mixtures by using the microplate toxicity analysis. The toxicities of three herbicides to C. pyrenoidosa are much higher than those to V. qinghaiensis, and the toxicities of metalaxyl and propoxur to V. qinghaiensis are higher than those to C. pyrenoidosa, while the toxicity of dodine to C. pyrenoidosa is similar to those to V. qinghaiensis. Using the concentration addition as an additive reference model, the binary pesticide mixtures exhibited different toxicity interactions, i.e., displayed antagonism to C. pyrenoidosa but synergism to V. qinghaiensis. However, the toxicities of the multi-component mixtures of more than two components are additive and can be predicted by the concentration addition model.

  18. Improved hydrogen photoproduction from photosynthetic bacteria and green algae

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, P.F.; Lien, S.; Seibert, M.

    1979-01-01

    Photosynthetic bacteria evolve hydrogen at much higher rates than do other classes of photosynthetic microorganisms. In addition, they tolerate harsh environments, grow rapidly, and utilize both visible and near infrared light in photosynthesis. They do not split water, but this does not necessarily eliminate their potential use in future applied systems. They are easily manipulated genetically, and thus might be modified to metabolize common biomass waste materials in place of expensive defined organic substrates. Furthermore, the potential for increasing hydrogen photoproduction via genetic techniques is promising. Strains that partially degrade cellulose, have high photoproduction rates, or contain very large amounts of the enzymes associated with hydrogen metabolism have been isolated. Green algae also produce hydrogen but are capable of using water as a substrate. For example, C. reinhardi can evolve hydrogen and oxygen at a molar ratio approaching 2:1. Based upon effect of dichlorophenyl dimethylurea (a specific inhibitor of photosystem II, PSII) on hydrogen photoproduction in the wild type strain and upon results obtained with PSII mutants, one can demonstrate that water is the major source of electrons for hydrogen production. The potential efficiency of in vivo coupling between hydrogenase and the photosynthetic electron transport system is high. Up to 76% of the reductants generated by the electron transport system can be channeled directly to the enzyme for in vivo hydrogen production. Rates exceeding 170 ..mu..moles of H/sub 2/ mg Chl/sup -1/ hr/sup -1/ have been observed.

  19. Coralline algae are global palaeothermometers with bi-weekly resolution

    Science.gov (United States)

    Kamenos, N. A.; Cusack, M.; Moore, P. G.

    2008-02-01

    High resolution palaeoclimate data are required for the Holocene to resolve differences recorded by current proxies. The pole to pole distribution of rhodoliths (coralline algae) with their annual and sub-annual calcite bands make these attractive candidates for such a role. These bands contain climate information in the form of elemental traces. In situ temperature (IST) was recorded at two rhodolith beds for 1.5 years. The concentrations of MgCO 3 and SrCO 3 (mol %) deposited in Lithothamion glaciale and Phymatolithon calcareum over this 18- month period were determined using electron and ion microprobes. Highly significant linear relationships exist between Mg, Sr and IST as well as sea surface temperature. Calibration between Mg concentration and IST was used to obtain a 2-year temperature profile from a subfossil rhodolith thallus indicating half the seasonal peak-to-peak temperature amplitude earlier during the Holocene than the present day. Both slow-growing species (rhodoliths make them unique globally distributed palaeothermometers which may help refine regional climate histories during the Holocene.

  20. Equal Sex Ratios of a Marine Green Alga, Bryopsis plumosa

    Institute of Scientific and Technical Information of China (English)

    Tatsuya Togashi; Paul Alan Cox

    2008-01-01

    By finding some important culture conditions as below, we succeeded in experimentally controlling the whole life history of a dioecious marine green alga, Bryopsis plumosa (Hudson) C. Agardh. In this study, we focused on the primary and secondary sex ratios (i.e. at inception and maturity) using these culture techniques. Gametogenesis was induced by culturing haploid gametophytes with Provasoli's enriched seawater (PES) medium under a 14:10 h light: dark cycle at 14 ℃. Formed zygotes grew into diploid sporophytes, which were cultured for 3 months with PES medium under a 14:10 h light: nbsp;dark cycle at 18℃. Then they were transferred into Schreiber medium and cultured under a 10:14 h light: dark cycle at 22℃. Within 1 week, zoosporogenesis was observed. Zoospores were released within a couple of days. Each zoospore soon germinated and grew into a unisexual gametophyte. The primary sex ratio was examined in gametophytes that originated from a single sporophyte. The secondary sex ratio was studied in the field. Both were estimated as 1:1.Synchronized meiotic cell divisions might occur during zoosporogenesis dividing each sex-determining factor evenly among zoospores. Given the equal sex ratio at maturity, there seems to be no environmental factor that differentially affects the survival of male or female gametophytes in nature.