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Sample records for chemolithoautotrophic marine magnetotactic

  1. Magnetotactic bacteria in marine sediments: clues from recent cores from Brazilian Coast

    Science.gov (United States)

    Jovane, L.; Pellizari, V. H.; Brandini, F. P.; Braga, E. D. S.; Freitas, G. R.; Benites, M.; Rodelli, D.; Giorgioni, M.; Iacoviello, F.; Ruffato, D. G.; Lins, U.

    2014-12-01

    The magnetic properties (first order reversal curves, ferromagnetic resonance and decomposition of saturation remanent magnetization acquisition) of marine magnetotactic bacteria, in conjunction with geophysical, geochemical and oceanographic data from the Brazilian Coast, provide interesting insights regarding the primary productivity distribution in oceans. This finding suggests that magnetite produced by some magnetotactic bacteria retains magnetic properties in relation to the crystallographic structure of the magnetic phase produced and thus might represent a "magnetic fingerprint" for the presence of magnetotactic bacteria. The use of those magnetic properties is a non-destructive, new technology that might allow for the identification and presence of specific species or types of magnetotactic bacteria in certain environments such as sediment. We will also show some preliminary results on the biogeochemical factors that control magnetotactic bacterial populations, documenting the environment and the preservation of bacterial magnetite, which dominates the palaeomagnetic signal throughout recent sediments from Brazilian Coast. We searched for magnetotactic bacteria in order to understand the ecosystems and environmental change related to their presence in sediments. We studied magnetotactic bacterial concentration and geophysical, geochemical and oceanographic results in marine settings measuring crucially nutrients availability in the water column and in sediments, on particulate delivery to the seafloor, to understand the environmental condition that allow the presence of magnetotactic bacteria and magnetosomes in sediments.

  2. Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

    Science.gov (United States)

    Gao, Jun; Pan, Hongmiao; Yue, Haidong; Song, Tao; Zhao, Yong; Chen, Guanjun; Wu, Longfei; Xiao, Tian

    2006-12-01

    Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in diameter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gram stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

  3. Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

    Institute of Scientific and Technical Information of China (English)

    GAO Jun; PAN Hongmiao; YUE Haidong; SONG Tao; ZHAO Yong; CHEN Guanjun; Wu Longfei; XIAO Tian

    2006-01-01

    Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in dimeter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gran stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

  4. Calcium-ion mediated assembly and function of glycosylated flagellar sheath of marine magnetotactic bacterium

    OpenAIRE

    Lefèvre, Christopher T; Santini, Claire-Lise; Bernadac, Alain; Zhang, Wei-Jia; Ying LI; Wu, Long-Fei

    2010-01-01

    Abstract Flagella of some pathogens or marine microbes are sheathed by an apparent extension of the outer cell membrane. Although flagellar sheath has been reported for almost 60 years, little is known about its function and the mechanism of its assembly. Recently, we have observed a novel type of sheath that encloses a flagellar bundle, instead of a single flagellum, in a marine magnetotactic bacterium MO-1. Here, we reported isolation and characterization of the sheath which can ...

  5. Population dynamics of marine magnetotactic bacteria in a meromictic salt pond described with qPCR.

    Science.gov (United States)

    Simmons, Sheri L; Bazylinski, Dennis A; Edwards, Katrina J

    2007-09-01

    Magnetotactic bacteria (MTB) contain membrane-bound magnetic iron minerals and are globally abundant in the suboxic/anoxic portions of chemically stratified marine and freshwater environments. However, their population dynamics and potential quantitative contribution to the biogeochemical cycles that they influence (iron, sulfur, carbon) have not been previously considered. Here we report the first quantitative description of the distribution of individual species of magnetite- and greigite-producing MTB in a natural system. We developed a quantitative polymerase chain reaction assay targeting 16s rRNA genes to enumerate four major groups of marine MTB, and applied the assay to samples collected with respect to geochemical parameters during summer 2003 in seasonally stratified Salt Pond, MA. Using catalysed reporter deposition-fluorescent in situ hybridization, we also show that a large greigite-producing bacterium is distantly related to Thiomicrospira pelophila in the Gammaproteobacteria. Ribosomal RNA copy numbers obtained with quantitative polymerase chain reaction indicate that MTB comprise up to 10% of total Bacteria and that each organism has a characteristic distributional profile with respect to the chemocline. PMID:17686015

  6. The Complete Genome Sequence of the Marine, Chemolithoautotrophic, Ammonia-Oxidizing Bacterium Nitrosococcus oceani ATCC19707

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, M G; Arp, D J; Chain, P S; El-Sheikh, A F; Hauser, L J; Hommes, N G; Larimer, F W; Malfatti, S A; Norton, J M; Poret-Peterson, A T; Vergez, L M; Ward, B B

    2006-08-03

    The Gammaproteobacterium, Nitrosococcus oceani (ATCC 19707), is a Gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. Sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; 50.4% G+C) and a plasmid (40,420 bp) that contain 3052 and 41 candidate protein-encoding genes, respectively. The genes encoding proteins necessary for the function of known modes of lithotrophy and autotrophy were identified. In contrast to betaproteobacterial nitrifier genomes, the N. oceani genome contained two complete rrn operons. In contrast, only one copy of the genes needed to synthesize functional ammonia monooxygenase and hydroxylamine oxidoreductase, as well as the proteins that relay the extracted electrons to a terminal electron acceptor were identified. The N. oceani genome contained genes for 13 complete two-component systems. The genome also contained all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle and the Embden-Meyerhof-Parnass and pentose phosphate pathways. The N. oceani genome contains the genes required to store and utilize energy from glycogen inclusion bodies and sucrose. Polyphosphate and pyrophosphate appear to be integrated in this bacterium's energy metabolism, stress tolerance and the ability to assimilate carbon via gluconeogenesis. One set of genes for type I RuBisCO was identified, while genes necessary for methanotrophy and for carboxysome formation were not identified. The N. oceani genome contains two copies each of the genes or operons necessary to assemble functional complexes I and IV as well as ATP synthase (one H{sup +}-dependent F{sub 0}F{sub 1}-type, one Na{sup +}-dependent V-type).

  7. Spatiotemporal Distribution of Marine Magnetotactic Bacteria in a Seasonally Stratified Coastal Salt Pond†

    OpenAIRE

    Simmons, S. L.; Sievert, S. M.; Frankel, R B; Bazylinski, D. A.; Edwards, K. J.

    2004-01-01

    The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displaye...

  8. Spatiotemporal distribution of marine magnetotactic bacteria in a seasonally stratified coastal salt pond.

    Science.gov (United States)

    Simmons, S L; Sievert, S M; Frankel, R B; Bazylinski, D A; Edwards, K J

    2004-10-01

    The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion that was present in relatively constant abundance over the course of the season. This rod is the first MB that appears to belong to the gamma-Proteobacteria, which may suggest an iron- rather than sulfur-based respiratory metabolism. Its distribution and phylogenetic identity suggest that an alternative model for the ecological and physiological role of magnetotaxis is needed for greigite-producing MB. PMID:15466570

  9. Structure and morphology of magnetite anaerobically-produced by a marine magnetotactic bacterium and a dissimilatory iron-reducing bacterium

    Science.gov (United States)

    Sparks, N.H.C.; Mann, S.; Bazylinski, D.A.; Lovley, D.R.; Jannasch, H.W.; Frankel, R.B.

    1990-01-01

    Intracellular crystals of magnetite synthesized by cells of the magnetotactic vibroid organism, MV-1, and extracellular crystals of magnetite produced by the non-magnetotactic dissimilatory iron-reducing bacterium strain GS-15, were examined using high-resolution transmission electron microscopy, electron diffraction and 57Fe Mo??ssbauer spectroscopy. The magnetotactic bacterium contained a single chain of approximately 10 crystals aligned along the long axis of the cell. The crystals were essentially pure stoichiometric magnetite. When viewed along the crystal long axis the particles had a hexagonal cross-section whereas side-on they appeared as rectangules or truncated rectangles of average dimension, 53 ?? 35 nm. These findings are explained in terms of a three-dimensional morphology comprising a hexagonal prism of {110} faces which are capped and truncated by {111} end faces. Electron diffraction and lattice imaging studies indicated that the particles were structurally well-defined single crystals. In contrast, magnetite particles produced by the strain, GS-15 were irregular in shape and had smaller mean dimensions (14 nm). Single crystals were imaged but these were not of high structural perfection. These results highlight the influence of intracellular control on the crystallochemical specificity of bacterial magnetites. The characterization of these crystals is important in aiding the identification of biogenic magnetic materials in paleomagnetism and in studies of sediment magnetization. ?? 1990.

  10. Structure and morphology of magnetite anaerobically-produced by a marine magnetotactic bacterium and a dissimilatory iron-reducing bacterium

    Science.gov (United States)

    Sparks, N. H. C.; Mann, S.; Bazylinski, D. A.; Lovley, D. R.; Jannasch, H. W.; Frankel, R. B.

    1990-04-01

    Intracellular crystals of magnetite synthesized by cells of the magnetotactic vibroid organism, MV-1, and extracellular crystals of magnetite produced by the non-magnetotactic dissimilatory iron-reducing bacterium strain GS-15, were examined using high-resolution transmission electron microscopy, electron diffraction and 57Fe Mo¨ssbauer spectroscopy. The magnetotactic bacterium contained a single chain of approximately 10 crystals aligned along the long axis of the cell. The crystals were essentially pure stoichiometric magnetite. When viewed along the crystal long axis the particles had a hexagonal cross-section whereas side-on they appeared as rectangules or truncated rectangles of average dimension, 53 × 35 nm. These findings are explained in terms of a three-dimensional morphology comprising a hexagonal prism of 110 faces which are capped and truncated by 111 end faces. Electron diffraction and lattice imaging studies indicated that the particles were structurally well-defined single crystals. In contrast, magnetite particles produced by the strain, GS-15 were irregular in shape and had smaller mean dimensions (14 nm). Single crystals were imaged but these were not of high structural perfection. These results highlight the influence of intracellular control on the crystallochemical specificity of bacterial magnetites. The characterization of these crystals is important in aiding the identification of biogenic magnetic materials in paleomagnetism and in studies of sediment magnetization.

  11. Motility of magnetotactic bacteria/MTB to Geomagnetic fields

    Science.gov (United States)

    Hidajatullah-Maksoed, Fatahillah

    2016-03-01

    Bacteria with motility directed by a local geomagnetic fields have been observed in marine sediments'' discussed by R. Blakemore, 1975. Magnetotactic bacteria/MTB discovered in 1963 by Salvatore Bellini. For ``off-axis electron holography in the transmission electron microscope was used to correlates the physical & magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria'' sought ``single-domain magnetite in hemopelagic sediments'' from JF Stolz. Otherwise, for potential source of bioproducts- product meant from result to multiplier -of magnetotactic bacteria[ACV Araujo, et.al, 2014 ] of marine drugs retrieved the `measurement of cellular chemotaxis with ECIS/Taxis, from KM Pietrosimone, 2012, whereas after ``earth magnetic field role on small living models'' are other interpretation of ``taxis'' as a movement of a cell instead usual ``tax'' for yew's taxus cuspidate, hired car & taxes in financial realms. Acknowledgements to HE. Mr. H. TUK SETYOHADI, Jl. Sriwijaya Raya 3, South-Jakarta, INDONESIA.

  12. Subcellular localization of the magnetosome protein MamC in the marine magnetotactic bacterium Magnetococcus marinus strain MC-1 using immunoelectron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Valverde-Tercedor, C [Universidad de Granada; Abada-Molina, F [Universidad de Granada; Martinez-Bueno, M [Universidad de Granada; Pineda-Molina, Estela [Laboratorio de Estudios Cristalograficos; Chen, Lijun [Ohio State University; Oestreicher, Zachery [Ohio State University; Lower, Brian H [Ohio State University; Lower, Steven K [Ohio State University; Bazylinski, Dennis A [Ames Laboratory; Jimenez-Lopez, C [Universidad de Granada

    2014-04-24

    Magnetotactic bacteria are a diverse group of prokaryotes that biomineralize intracellular magnetosomes, composed of magnetic (Fe3O4) crystals each enveloped by a lipid bilayer membrane that contains proteins not found in other parts of the cell. Although partial roles of some of these magnetosome proteins have been determined, the roles of most have not been completely elucidated, particularly in how they regulate the biomineralization process. While studies on the localization of these proteins have been focused solely on Magnetospirillum species, the goal of the present study was to determine, for the first time, the localization of the most abundant putative magnetosome membrane protein, MamC, in Magnetococcus marinus strain MC-1. MamC was expressed in Escherichia coli and purified. Monoclonal antibodies were produced against MamC and immunogold labeling TEM was used to localize MamC in thin sections of cells of M. marinus. Results show that MamC is located only in the magnetosome membrane of Mc. marinus. Based on our findings and the abundance of this protein, it seems likely that it is important in magnetosome biomineralization and might be used in controlling the characteristics of synthetic nanomagnetite.

  13. A biogeographic distribution of magnetotactic bacteria influenced by salinity

    OpenAIRE

    Lin, Wei; Wang, Yinzhao; Li, Bi; Pan, Yongxin

    2011-01-01

    Magnetotactic bacteria (MTB), which synthesize intracellular ferromagnetic magnetite and/or greigite magnetosomes, have significant roles in global iron cycling in aquatic systems, as well as sedimentary magnetism. The occurrence of MTB has been reported in aquatic environments from freshwater to marine ecosystems; however, the distribution of MTB across heterogeneous habitats remains unclear. Here we examined the MTB communities from diverse habitats across northern and southern China, using...

  14. Magnetotactic Bacteria from Extreme Environments

    OpenAIRE

    Lefèvre, Christopher T; Dennis A. Bazylinski

    2013-01-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI) in water columns or sediments of aqu...

  15. Characterization of Mediterranean Magnetotactic Bacteria

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Magnetotactic bacteria are a diverse group of motile prokaryotes that are ubiquitous in aquatic habitats and cosmopolitan in distribution. In this study, we collected magnetotactic bacteria from the Mediterranean Sea. A remarkable diversity of morphotypes was observed, including muiticellular types that seemed to differ from those previously found in North and South America. Another interesting organism was one with magnetosomes arranged in a six-stranded bundle which occupied one third of the cell width. The magnetosome bundle was evident even under optic microscopy. These cells were connected together and swam as a linear entire unit. Magnetosomes did not always align up to form a straight linear chain. A chain composed of rectangle magnetosomes bent at a position with an oval crystal. High resolution transmission electron microscopy analysis of the crystal at the pivotal position suggested uncompleted formation of the crystal. This is the first report of Mediterranean magnetotactic bacteria, which should be useful for studies of biogeochemical cycling and geohistory of the Mediterranean Sea.

  16. Velocity condensation for magnetotactic bacteria

    CERN Document Server

    Rupprecht, Jean-Francois; Bocquet, Lydéric

    2015-01-01

    Magnetotactic swimmers tend to align along magnetic field lines against stochastic reorientations. We show that the swimming strategy, e.g. active Brownian motion versus run-and-tumble dynamics, strongly affects the orientation statistics. The latter can exhibit a velocity condensation whereby the alignment probability density diverges. As a consequence, we find that the swimming strategy affects the nature of the phase transition to collective motion, indicating that L\\'evy run-and-tumble walks can outperform active Brownian processes as strategies to trigger collective behavior.

  17. Velocity Condensation for Magnetotactic Bacteria.

    Science.gov (United States)

    Rupprecht, Jean-François; Waisbord, Nicolas; Ybert, Christophe; Cottin-Bizonne, Cécile; Bocquet, Lydéric

    2016-04-22

    Magnetotactic swimmers tend to align along magnetic field lines against stochastic reorientations. We show that the swimming strategy, e.g., active Brownian motion versus run-and-tumble dynamics, strongly affects the orientation statistics. The latter can exhibit a velocity condensation whereby the alignment probability density diverges. As a consequence, we find that the swimming strategy affects the nature of the phase transition to collective motion, indicating that Lévy run-and-tumble walks can outperform active Brownian processes as strategies to trigger collective behavior. PMID:27152825

  18. Magnetotactic Bacteria from Extreme Environments

    Science.gov (United States)

    Bazylinski, Dennis A.; Lefère, Christopher T.

    2013-03-01

    Magnetotactic bacteria (MTB) represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4) or greigite (Fe3S4) and cause cells to align along the Earth's geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic-anoxic interface (OAI) in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC) bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  19. Magnetotactic Bacteria from Extreme Environments

    Directory of Open Access Journals (Sweden)

    Christopher T. Lefèvre

    2013-03-01

    Full Text Available Magnetotactic bacteria (MTB represent a diverse collection of motile prokaryotes that biomineralize intracellular, membrane-bounded, tens-of-nanometer-sized crystals of a magnetic mineral called magnetosomes. Magnetosome minerals consist of either magnetite (Fe3O4 or greigite (Fe3S4 and cause cells to align along the Earth’s geomagnetic field lines as they swim, a trait called magnetotaxis. MTB are known to mainly inhabit the oxic–anoxic interface (OAI in water columns or sediments of aquatic habitats and it is currently thought that magnetosomes function as a means of making chemotaxis more efficient in locating and maintaining an optimal position for growth and survival at the OAI. Known cultured and uncultured MTB are phylogenetically associated with the Alpha-, Gamma- and Deltaproteobacteria classes of the phylum Proteobacteria, the Nitrospirae phylum and the candidate division OP3, part of the Planctomycetes-Verrucomicrobia-Chlamydiae (PVC bacterial superphylum. MTB are generally thought to be ubiquitous in aquatic environments as they are cosmopolitan in distribution and have been found in every continent although for years MTB were thought to be restricted to habitats with pH values near neutral and at ambient temperature. Recently, however, moderate thermophilic and alkaliphilic MTB have been described including: an uncultured, moderately thermophilic magnetotactic bacterium present in hot springs in northern Nevada with a probable upper growth limit of about 63 °C; and several strains of obligately alkaliphilic MTB isolated in pure culture from different aquatic habitats in California, including the hypersaline, extremely alkaline Mono Lake, with an optimal growth pH of >9.0.

  20. A biogeographic distribution of magnetotactic bacteria influenced by salinity.

    Science.gov (United States)

    Lin, Wei; Wang, Yinzhao; Li, Bi; Pan, Yongxin

    2012-02-01

    Magnetotactic bacteria (MTB), which synthesize intracellular ferromagnetic magnetite and/or greigite magnetosomes, have significant roles in global iron cycling in aquatic systems, as well as sedimentary magnetism. The occurrence of MTB has been reported in aquatic environments from freshwater to marine ecosystems; however, the distribution of MTB across heterogeneous habitats remains unclear. Here we examined the MTB communities from diverse habitats across northern and southern China, using comprehensive transmission electron microscopy and comparison of 16S rRNA gene analyses. A total of 334 16S rRNA gene sequences were analyzed, representing the most comprehensive analysis on the diversity and distribution of MTB to date. The majority (95%) of sequences belong to the Alphaproteobacteria, whereas a population of giant magnetotactic rod is affiliated with the Nitrospirae phylum. By a statistical comparison of these sequence data and publicly available MTB sequences, we infer for the first time that the composition of MTB communities represents a biogeographic distribution across globally heterogeneous environments, which is influenced by salinity. PMID:21866181

  1. DMTB: the magnetotactic bacteria database

    Science.gov (United States)

    Pan, Y.; Lin, W.

    2012-12-01

    Magnetotactic bacteria (MTB) are of interest in biogeomagnetism, rock magnetism, microbiology, biomineralization, and advanced magnetic materials because of their ability to synthesize highly ordered intracellular nano-sized magnetic minerals, magnetite or greigite. Great strides for MTB studies have been made in the past few decades. More than 600 articles concerning MTB have been published. These rapidly growing data are stimulating cross disciplinary studies in such field as biogeomagnetism. We have compiled the first online database for MTB, i.e., Database of Magnestotactic Bacteria (DMTB, http://database.biomnsl.com). It contains useful information of 16S rRNA gene sequences, oligonucleotides, and magnetic properties of MTB, and corresponding ecological metadata of sampling sites. The 16S rRNA gene sequences are collected from the GenBank database, while all other data are collected from the scientific literature. Rock magnetic properties for both uncultivated and cultivated MTB species are also included. In the DMTB database, data are accessible through four main interfaces: Site Sort, Phylo Sort, Oligonucleotides, and Magnetic Properties. References in each entry serve as links to specific pages within public databases. The online comprehensive DMTB will provide a very useful data resource for researchers from various disciplines, e.g., microbiology, rock magnetism and paleomagnetism, biogeomagnetism, magnetic material sciences and others.

  2. Magnetotactic bacteria and microjets: A comparative study

    NARCIS (Netherlands)

    Khalil, Islam S.M.; Magdanz, Veronika; Sanchez, Samuel; Schmidt, Oliver G.; Misra, Sarthak

    2013-01-01

    We provide a comparative study between two self-propelled microrobots, i.e., magnetotactic bacteria and microjets. This study includes characterization of their fluidic properties (linear and rotational drag coefficients) based on their morphologies and characterization of their magnetic properties

  3. Magnetotactic bacteria: nanodrivers of the future.

    Science.gov (United States)

    Mathuriya, Abhilasha Singh

    2016-10-01

    Magnetotactic bacteria (MTB) represent a heterogeneous group of Gram-negative aquatic prokaryotes with a broad range of morphological types, including vibrioid, coccoid, rod and spirillum. MTBs possess the virtuosity to passively align and actively swim along the magnetic field. Magnetosomes are the trademark nano-ranged intracellular structures of MTB, which comprise magnetic iron-bearing inorganic crystals enveloped by an organic membrane, and are dedicated organelles for their magnetotactic lifestyle. Magnetosomes endue high and even dispersion in aqueous solutions compared with artificial magnetites, claiming them as paragon nanomaterials. MTB and magnetosomes offer high technological potential in modern science, technology and medicines. This review focuses on the applicability of MTB and magnetosomes in various areas of modern benefits. PMID:26287367

  4. The chemical formula of a magnetotactic bacterium.

    Science.gov (United States)

    Naresh, Mohit; Das, Sayoni; Mishra, Prashant; Mittal, Aditya

    2012-05-01

    Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio-derived products by regulating intra-cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as CH(2.06)O(0.13)N(0.28)Fe(1.74×10(-3)). Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life.

  5. High Diversity of Magnetotactic Deltaproteobacteria in a Freshwater Niche

    OpenAIRE

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-01-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes.

  6. High diversity of magnetotactic deltaproteobacteria in a freshwater niche.

    Science.gov (United States)

    Wang, Yinzhao; Lin, Wei; Li, Jinhua; Pan, Yongxin

    2013-04-01

    Knowledge of the diversity of magnetotactic bacteria in natural environments is crucial for understanding their contribution to various biological and geological processes. Here we report a high diversity of magnetotactic bacteria in a freshwater site. Ten out of 18 operational taxonomic units (OTUs) were affiliated with the Deltaproteobacteria. Some rod-shaped bacteria simultaneously synthesized greigite and magnetite magnetosomes. PMID:23377941

  7. Design and application of the method for isolating magnetotactic bacteria

    Institute of Scientific and Technical Information of China (English)

    XIAO Zhijie; LIAN Bin; CHEN Jun; H. Henry Teng

    2007-01-01

    A simple apparatus was designed to effectively isolate magnetotactic bacteria from soils or sediments based on their magnetotaxis. Through a series of processes including sample incubation, MTB harvesting, isolation, purification and identification, several strains of bacteria were isolated from the samples successfully. By Transmission Electron Microscopy (TEM) and Energy-Dispersive X-ray Analysis (EDXA), these bacteria were certificated to be magnetotactic bacteria. The phylogenetic relationship between the isolated magnetic strains and some known magnetotactic bacteria was inferred by the construction of phylogenetic tree based on 16SrDNA sequences. This apparatus has been proven to have the advantages of being inexpensive, simple to assemble, easy to perform and highly efficient to isolate novel magnetotactic bacteria. The research indicated that the combined approach of harvesting MTB by home-made apparatus and the method of plate colony isolation could purify and isolate magnetotactic bacteria effectively.

  8. Magnetic fingerprint in marine sediments: clues from cultivated Magnetovibrio blakemorei and recent cores from Brazilian Coast

    Science.gov (United States)

    Jovane, L.; Florindo, F.; Bazylinski, D. A.; Pellizari, V. H.; Brandini, F. P.; de Almeida, L. A.; Carneiro, F. R.; Braga, E. D.; Lins, U.

    2013-12-01

    The magnetic properties (first order reversal curves, ferromagnetic resonance and decomposition of saturation remanent magnetization acquisition) of Magnetovibrio blakemorei strain MV-1, a marine magnetotactic bacterium, differ from those of other magnetotactic species from sediments deposited in lakes and marine habitats previously studied. This finding suggests that magnetite produced by some magnetotactic bacteria retains magnetic properties in relation to the crystallographic structure of the magnetic phase produced and thus might represent a 'magnetic fingerprint' for a specific magnetotactic bacterium. The technique used to determine this fingerprint is a non-destructive, new technology that might allow for the identification and presence of specific species or types of magnetotactic bacteria in certain environments such as sediment. We also show some preliminary results on the biogeochemical factors that control magnetotactic bacterial populations, documenting the environment and the preservation of bacterial magnetite, which dominates the palaeomagnetic signal throughout recent sediments from Brazilian Coast. We searched for magnetotactic bacteria in order to understand the ecosystems and environmental change related to their presence in sediments. We focused on studying the environmental conditions that allow for the presence of magnetotactic bacteria and magnetosomes in sediments including determining magnetotactic bacterial populations in marine settings, measuring crucial nutrient availability in the water column and in sediments, and examining particulate delivery to the seafloor.

  9. Magnetotactic bacteria and magnetosomes - Scope and challenges.

    Science.gov (United States)

    Jacob, Jobin John; Suthindhiran, K

    2016-11-01

    Geomagnetism aided navigation has been demonstrated by certain organisms which allows them to identify a particular location using magnetic field. This attractive technique to recognize the course was earlier exhibited in numerous animals, for example, birds, insects, reptiles, fishes and mammals. Magnetotactic bacteria (MTB) are one of the best examples for magnetoreception among microorganisms as the magnetic mineral functions as an internal magnet and aid the microbe to move towards the water columns in an oxic-anoxic interface (OAI). The ability of MTB to biomineralize the magnetic particles (magnetosomes) into uniform nano-sized, highly crystalline structure with uniform magnetic properties has made the bacteria an important topic of research. The superior properties of magnetosomes over chemically synthesized magnetic nanoparticles made it an attractive candidate for potential applications in microbiology, biophysics, biochemistry, nanotechnology and biomedicine. In this review article, the scope of MTB, magnetosomes and its challenges in research and industrial application have been discussed in brief. This article mainly focuses on the application based on the magnetotactic behaviour of MTB and magnetosomes in different areas of modern science. PMID:27524094

  10. Isolation, cultivation and genomic analysis of magnetosome biomineralization genes of a new genus of South-seeking magnetotactic cocci within the Alphaproteobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Morillo, Viviana [Universidade Federal do Rio de Janeiro; Abreu, Fernanda [Universidade Federal do Rio de Janeiro; Araujo, Ana C [Universidade Federal do Rio de Janeiro; de Almeida, Luiz G [Laboratorio Nacional de Computacao Cientifica; Enrich-Prast, Alex [Universidade Federal do Rio de Janeiro; Farina, Marcos [Universidade Federal do Rio de Janeiro; de Vasconcelos, Ana T [Laboratorio Nacional de Computacao Cientifica; Bazylinski, Dennis A [Ames Laboratory; Lins, Ulysses [Universidade Federal do Rio de Janeiro

    2014-01-01

    Although magnetotactic bacteria (MTB) are ubiquitous in aquatic habitats, they are still considered fastidious microorganisms with regard to growth and cultivation with only a relatively low number of axenic cultures available to date. Here, we report the first axenic culture of an MTB isolated in the Southern Hemisphere (Itaipu Lagoon in Rio de Janeiro, Brazil). Cells of this new isolate are coccoid to ovoid in morphology and grow microaerophilically in semi-solid medium containing an oxygen concentration ([O2]) gradient either under chemoorganoheterotrophic or chemolithoautotrophic conditions. Each cell contains a single chain of approximately 10 elongated cuboctahedral magnetite (Fe3O4) magnetosomes. Phylogenetic analysis based on the 16S rRNA gene sequence shows that the coccoid MTB isolated in this study represents a new genus in the Alphaproteobacteria; the name Magnetofaba australis strain IT-1 is proposed. Preliminary genomic data obtained by pyrosequencing shows that M. australis strain IT-1 contains a genomic region with genes involved in biomineralization similar to those found in the most closely related magnetotactic cocci Magnetococcus marinus strain MC-1. However, organization of the magnetosome genes differs from M. marinus.

  11. Birefringence Determination of Magnetic Moments of Magnetotactic Bacteria

    OpenAIRE

    Rosenblatt, Charles; de Araujo, F. Flavio Torres; Frankel, Richard B.

    1982-01-01

    A birefringence technique is used to determine the average magnetic moments of magnetotactic bacteria in culture. Differences in are noted between live and dead bacteria, as well as between normal density and high density samples of live bacteria.

  12. Enhanced fatty acid production in engineered chemolithoautotrophic bacteria using reduced sulfur compounds as energy sources

    DEFF Research Database (Denmark)

    Beller, Harry R.; Zhou, Peng; Jewell, Talia N.M.;

    2016-01-01

    Chemolithoautotrophic bacteria that oxidize reduced sulfur compounds, such as H2S, while fixing CO2 are an untapped source of renewable bioproducts from sulfide-laden waste, such as municipal wastewater. In this study, we report engineering of the chemolithoautotrophic bacterium Thiobacillus...

  13. Magnetotactic bacteria. Promising biosorbents for heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Wei; Zhang, Yanzong; Ding, Xiaohui; Liu, Yan; Shen, Fei; Zhang, Xiaohong; Deng, Shihuai; Xiao, Hong; Yang, Gang; Peng, Hong [Sichuan Agricultural Univ., Chengdu (China). Provincial Key Lab. of Agricultural Environmental Engineering

    2012-09-15

    Magnetotactic bacteria (MTB), which can orient and migrate along a magnetic line of force due to intracellular nanosized magnetosomes, have been a subject of research in the medical field, in dating environmental changes, and in environmental remediation. This paper reviews the recent development of MTB as biosorbents for heavy metals. Ultrastructures and taxis of MTB are investigated. Adsorptions in systems of unitary and binary ions are highlighted, as well as adsorption conditions (temperature, pH value, biomass concentration, and pretreatments). The separation and desorption of MTB in magnetic separators are also discussed. A green method to produce metal nanoparticles is provided, and an energy-efficient way to recover precious metals is put forward during biosorption. (orig.)

  14. Oxidation of Molecular Hydrogen by a Chemolithoautotrophic Beggiatoa Strain

    Science.gov (United States)

    2016-01-01

    ABSTRACT A chemolithoautotrophic strain of the family Beggiatoaceae, Beggiatoa sp. strain 35Flor, was found to oxidize molecular hydrogen when grown in a medium with diffusional gradients of oxygen, sulfide, and hydrogen. Microsensor profiles and rate measurements suggested that the strain oxidized hydrogen aerobically when oxygen was available, while hydrogen consumption under anoxic conditions was presumably driven by sulfur respiration. Beggiatoa sp. 35Flor reached significantly higher biomass in hydrogen-supplemented oxygen-sulfide gradient media, but hydrogen did not support growth of the strain in the absence of reduced sulfur compounds. Nevertheless, hydrogen oxidation can provide Beggiatoa sp. 35Flor with energy for maintenance and assimilatory purposes and may support the disposal of internally stored sulfur to prevent physical damage resulting from excessive sulfur accumulation. Our knowledge about the exposure of natural populations of Beggiatoaceae to hydrogen is very limited, but significant amounts of hydrogen could be provided by nitrogen fixation, fermentation, and geochemical processes in several of their typical habitats such as photosynthetic microbial mats and submarine sites of hydrothermal fluid flow. IMPORTANCE Reduced sulfur compounds are certainly the main electron donors for chemolithoautotrophic Beggiatoaceae, but the traditional focus on this topic has left other possible inorganic electron donors largely unexplored. In this paper, we provide evidence that hydrogen oxidation has the potential to strengthen the ecophysiological plasticity of Beggiatoaceae in several ways. Moreover, we show that hydrogen oxidation by members of this family can significantly influence biogeochemical gradients and therefore should be considered in environmental studies. PMID:26896131

  15. From Magnetotactic Bacteria to Sediment Magnetizations: new insights

    Science.gov (United States)

    Egli, R.; Mao, X.; Zhao, X.

    2015-12-01

    Magnetotactic bacteria (MTB) represent one of the most intriguing examples of iron biomineralization and magnetic navigation in nature. MTB synthesize magnetic nanocrystals, called magnetosomes, which act as an incorporated compass for navigation purposes (magnetotaxis). MTB are ubiquitous organisms living in chemically stratified freshwater and marine environments, where they contribute significantly to the Fe cycle. Magnetosomes accumulate as fossil MTB remains in sediment (magnetofossils). The recent development of magnetic measurement protocols enabling to detect small magnetosome concentrations among complex iron mineral mixtures led to the discovery that magnetofossil preservation over geological times is not uncommon. Therefore, magnetofossils can play an important role in sedimentary records of the Earth's magnetic field, as well as conveying selective information about past environmental conditions (e.g. redox conditions and nutrient concentration). Paleomagnetic and environmental applications require us to understand the processes that control MTB occurrence, magnetofossil formation and preservation, and the final alignment with the Earth's magnetic field. Our current knowledge relies mostly on experiments performed with cultured MTB in aqueous solutions, under physical and chemical conditions that do not necessarily reproduce those encountered in sediment. These experiments have been pivotal for understanding magnetosome growth and the fundaments of magnetotaxis. On the other hand, recent investigations of living MTB populations in sediment with specially developed observation techniques led to unexpected findings, with important implications for magnetotaxis models, MTB ecology, and, indirectly, for modeling the acquisition of natural magnetizations in bioturbated sediments. Ludwig, P. et al. (2013), Global Planet. Change 110, 321-339. Mao, X. et al. (2014), Geochem. Geophys. Geosys. 15, doi:10.1002/2013GC005034. Mao, X. et al. (2014). PLoS ONE 9, doi

  16. On the swimming motion of spheroidal magnetotactic bacteria

    International Nuclear Information System (INIS)

    We investigate, via both theoretical and experimental methods, the swimming motion of magnetotactic bacteria having the shape of an elongated prolate spheroid in a viscous liquid under the influence of an imposed magnetic field. A fully three-dimensional Stokes flow, driven by the translation and rotation of a swimming bacterium, exerts a complicated viscous drag/torque on the motion of a non-spherical bacterium. By assuming that the body of the bacterium is non-deformable and that the interaction between different bacteria is weak and hence negligible, we have derived a system of 12 coupled nonlinear ordinary differential equations that govern both the motion and the orientation of a swimming spheroidal magnetotactic bacterium. The focus of the study is on how the shape of a non-spherical magnetotactic bacterium, marked by the size of its eccentricity, affects the pattern of its swimming motion. It is revealed that the pattern/speed of a swimming spheroidal magnetotactic bacterium is highly sensitive not only to the direction of its magnetic moment but also to its shape. We also compare the theoretical pattern obtained from the solutions of the 12 coupled differential equations with that observed in the laboratory experiments using the magnetotactic bacteria found in Lake Miyun near Beijing, China, showing that the observed pattern can be largely reproduced with an appropriate set of parameters in our theoretical model. (paper)

  17. Magnetotactic bacteria on Earth and on Mars.

    Science.gov (United States)

    McKay, Christopher P; Friedmann, E Imre; Frankel, Richard B; Bazylinski, Dennis A

    2003-01-01

    Continued interest in the possibility of evidence for life in the ALH84001 Martian meteorite has focused on the magnetite crystals. This review is structured around three related questions: is the magnetite in ALH84001 of biological or non-biological origin, or a mixture of both? does magnetite on Earth provide insight to the plausibility of biogenic magnetite on Mars? could magnetotaxis have developed on Mars? There are credible arguments for both the biological and non-biological origin of the magnetite in ALH84001, and we suggest that more studies of ALH84001, extensive laboratory simulations of non-biological magnetite formation, as well as further studies of magnetotactic bacteria on Earth will be required to further address this question. Magnetite grains produced by bacteria could provide one of the few inorganic traces of past bacterial life on Mars that could be recovered from surface soils and sediments. If there was biogenic magnetite on Mars in sufficient abundance to leave fossil remains in the volcanic rocks of ALH84001, then it is likely that better-preserved magnetite will be found in sedimentary deposits on Mars. Deposits in ancient lakebeds could contain well-preserved chains of magnetite clearly indicating a biogenic origin.

  18. Magnetotactic Bacteria as Potential Sources of Bioproducts

    Directory of Open Access Journals (Sweden)

    Ana Carolina V. Araujo

    2015-01-01

    Full Text Available Magnetotactic bacteria (MTB produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4 or greigite (Fe3S4 enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.

  19. Magnetotactic bacteria as potential sources of bioproducts.

    Science.gov (United States)

    Araujo, Ana Carolina V; Abreu, Fernanda; Silva, Karen Tavares; Bazylinski, Dennis A; Lins, Ulysses

    2015-01-01

    Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4) enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species. PMID:25603340

  20. Magnetic Torque of Microfabricated Elements and Magnetotactic Bacteria

    CERN Document Server

    Zondervan, Lars; Khalil, Islam S M; Pichel, Marc P; Misra, Sarthak; Abelmann, Leon

    2014-01-01

    We present a thorough theoretical analysis of the magnetic torque on microfabricated elements with dimensions in the range of 100 to 500 {\\mu}m and magneto-somes of magnetotactic bacteria of a few {\\mu}m length. We derive simple equations for field dependent torque and magnetic shape anisotropy that can be readily used to replace the crude approximations commonly used. We illustrate and verify the theory on microfabricated elements and magnetotactic bacteria, by field depedent torque magnetometry and by observing their rotation in water under application of a rotating magnetic field. The maximum rotation frequency of the largest microfabricated elements agrees within error boundaries with theory. For smaller, and especially thinner, elements the measured frequencies are a factor of three to four too low. We suspect this is caused by incomplete saturation of the magnetisation in the elements, which is not incorporated in our model. The maximum rotation frequency of magnetotactic bacteria agrees with our model ...

  1. Manganese in biogenic magnetite crystals from magnetotactic bacteria.

    Science.gov (United States)

    Keim, Carolina N; Lins, Ulysses; Farina, Marcos

    2009-03-01

    Magnetotactic bacteria produce either magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4)) crystals in cytoplasmic organelles called magnetosomes. Whereas greigite magnetosomes can contain up to 10 atom% copper, magnetite produced by magnetotactic bacteria was considered chemically pure for a long time and this characteristic was used to distinguish between biogenic and abiogenic crystals. Recently, it was shown that magnetosomes containing cobalt could be produced by three strains of Magnetospirillum. Here we show that magnetite crystals produced by uncultured magnetotactic bacteria can incorporate manganese up to 2.8 atom% of the total metal content (Fe+Mn) when manganese chloride is added to microcosms. Thus, chemical purity can no longer be taken as a strict prerequisite to consider magnetite crystals to be of biogenic origin. PMID:19187208

  2. Genetic manipulation of the obligate chemolithoautotrophic bacterium Thiobacillus denitrificans

    Energy Technology Data Exchange (ETDEWEB)

    Beller, H.R.; Legler, T.C.; Kane, S.R.

    2011-07-15

    Chemolithoautotrophic bacteria can be of industrial and environmental importance, but they present a challenge for systems biology studies, as their central metabolism deviates from that of model organisms and there is a much less extensive experimental basis for their gene annotation than for typical organoheterotrophs. For microbes with sequenced genomes but unconventional metabolism, the ability to create knockout mutations can be a powerful tool for functional genomics and thereby render an organism more amenable to systems biology approaches. In this chapter, we describe a genetic system for Thiobacillus denitrificans, with which insertion mutations can be introduced by homologous recombination and complemented in trans. Insertion mutations are generated by in vitro transposition, the mutated genes are amplified by the PCR, and the amplicons are introduced into T. denitrificans by electroporation. Use of a complementation vector, pTL2, based on the IncP plasmid pRR10 is also addressed.

  3. Productivity-Diversity Relationships from Chemolithoautotrophically Based Sulfidic Karst Systems

    Directory of Open Access Journals (Sweden)

    Porter Megan L.

    2009-01-01

    Full Text Available Although ecosystems thriving in the absence of photosynthetic processes are no longer considered unique phenomena, we haveyet to understand how these ecosystems are energetically sustained via chemosynthesis. Ecosystem energetics were measuredin microbial mats from active sulfidic caves (Movile Cave, Romania; Frasassi Caves, Italy; Lower Kane Cave, Wyoming, USA; andCesspool Cave, Virginia, USA using radiotracer techniques. We also estimated bacterial diversity using 16S rRNA sequences torelate the productivity measurements to the composition of the microbial communities. All of the microbial communities investigatedwere dominated by chemolithoautotrophic productivity, with the highest rates from Movile Cave at 281 g C/m2/yr. Heterotrophicproductivities were at least one order of magnitude less than autotrophy from all of the caves. We generated 414 new 16S rRNAgene sequences that represented 173 operational taxonomic units (OTUs with 99% sequence similarity. Although 13% of theseOTUs were found in more than one cave, the compositions of each community were significantly different from each other (P≤0.001.Autotrophic productivity was positively correlated with overall species richness and with the number of bacterial OTUs affiliated withthe Epsilonproteobacteria, a group known for sulfur cycling and chemolithoautotrophy. Higher rates of autotrophy were also stronglypositively correlated to available metabolic energy sources, and specifically to dissolved sulfide concentrations. The relationship ofautotrophic productivity and heterotrophic cycling rates to bacterial species richness can significantly impact the diversity of highertrophic levels in chemolithoautotrophically-based cave ecosystems, with the systems possessing the highest productivity supportingabundant and diverse macro-invertebrate communities.

  4. Magnetic studies of magnetotactic bacteria by soft x-ray STXM and ptychography

    Science.gov (United States)

    Zhu, X. H.; Tyliszczak, T.; Shiu, H.-W.; Shapiro, D.; Bazylinski, D. A.; Lins, U.; Hitchcock, A. P.

    2016-01-01

    Magnetotactic bacteria (MTB) biomineralize chains of nanoscale magnetite single crystals which align the cell with the earth's magnetic field and assist the cell to migrate to, and maintain its position at, the oxic-anoxic transition zone, their preferred habitat. Here we describe use of multi-edge scanning transmission X-ray microscopy (STXM) to investigate the chemistry and magnetism of MTB on an individual cell basis. We report measurements of the orientation of the magnetic vector of magnetosome chains relative to the location of the single flagellum in marine vibrio, Magnetovibrio blakemorei strain MV-1 cells from both the southern and northern hemisphere. We also report a major improvement in both spatial resolution and spectral quality through the use of spectro-ptychography at the Fe L3 edge.

  5. Uncultivated Magnetotactic Cocci from Yuandadu Park in Beijing, China▿

    Science.gov (United States)

    Lin, Wei; Pan, Yongxin

    2009-01-01

    In the present study, we investigated a group of uncultivated magnetotactic cocci, which was magnetically isolated from a freshwater pond in Beijing, China. Light and transmission electron microscopy showed that these cocci ranged from 1.5 to 2.5 μm and contained two to four chains of magnetite magnetosomes, which sometimes were partially disorganized. Overall, the size of the disorganized magnetosomes was significantly smaller than that arranged in chains. All characterized magnetosome crystals were elongated (shape factor = 0.64) and fall into the single-domain size range (30 to 115 nm). Comparative 16S rRNA gene sequence analysis and fluorescence in situ hybridization showed that the enriched bacteria were a virtually homogeneous population and represented a novel lineage in the Alphaproteobacteria. The closest cultivated relative was magnetotactic coccoid strain MC-1 (88% sequence identity). First-order reversal curve diagrams revealed that these cocci had relatively strong magnetic interactions compared to the single-chain magnetotactic bacteria. Low-temperature magnetic measurements showed that the Verwey transition of them was ∼108 K, confirming magnetite magnetosomes, and the delta ratio δFC/δZFC was >2. Based on the structure, phylogenetic position and magnetic properties, the enriched magnetotactic cocci of Alphaproteobacteria are provisionally named as “Candidatus Magnetococcus yuandaducum.” PMID:19376904

  6. Magnetotactic Bacterial Cages as Safe and Smart Gene Delivery Vehicles

    KAUST Repository

    Alsaiari, Shahad K.

    2016-07-27

    In spite of the huge advances in the area of synthetic carriers, their efficiency still poorly compares to natural vectors. Herein, we report the use of unmodified magnetotactic bacteria as a guidable delivery vehicle for DNA functionalized gold nanoparticles (AuNPs). High cargo loading is established under anaerobic conditions (bacteria is alive) through endocytosis where AuNPs are employed as transmembrane proteins mimics (facilitate endocytosis) as well as imaging agents to verify and quantify loading and release. The naturally bio-mineralized magnetosomes, within the bacteria, induce heat generation inside bacteria through magnetic hyperthermia. Most importantly after exposing the system to air (bacteria is dead) the cell wall stays intact providing an efficient bacterial vessel. Upon incubation with THP-1 cells, the magnetotactic bacterial cages (MBCs) adhere to the cell wall and are directly engulfed through the phagocytic activity of these cells. Applying magnetic hyperthermia leads to the dissociation of the bacterial microcarrier and eventual release of cargo.

  7. Destabilization of a flow focused suspension of magnetotactic bacteria

    Science.gov (United States)

    Waisbord, Nicolas; Lefèvre, Christopher T.; Bocquet, Lydéric; Ybert, Christophe; Cottin-Bizonne, Cécile

    2016-09-01

    Active matter is a new class of intrinsically out-of equilibrium material with intriguing properties. The recent upsurge of studies in this field has mostly focused on the spontaneous behavior of these systems. Yet, many systems evolve under external constraints and driving forces, being subjected to both flow and various taxis. We present a new experimental system based on the directional control of magnetotactic bacteria which enables quantitative investigations to complement the challenging theoretical description of such systems. We explore the behavior of self-propelled magnetotactic bacteria as a particularly rich and versatile class of driven matter, whose behavior can be studied under a range of hydrodynamic and magnetic field stimuli. In particular we demonstrate that the competition between cell orientation toward a magnetic field and hydrodynamic flow lead not only to jetting, but to a new pearling instability. This model system illustrates new structuring capabilities of driven active matter.

  8. Molecular Mechanisms of Compartmentalization and Biomineralization in Magnetotactic Bacteria

    OpenAIRE

    Komeili, Arash

    2012-01-01

    Magnetotactic bacteria are remarkable organisms with the ability to exploit the earth’s magnetic field for navigational purposes. To do this, they build specialized compartments called magnetosomes that consist of a lipid membrane and a crystalline magnetic mineral. These organisms have the potential to serve as models for the study of compartmentalization as well as biomineralization in bacteria. Additionally, they offer the opportunity to design applications that take advantage of the parti...

  9. The identification and biogeochemical interpretation of fossil magnetotactic bacteria

    OpenAIRE

    Kopp, Robert E.; Kirschvink, Joseph L

    2008-01-01

    Magnetotactic bacteria, which most commonly live within the oxic-anoxic transition zone (OATZ) of aquatic environments, produce intracellular crystals of magnetic minerals, specifically magnetite or greigite. The crystals cause the bacteria to orient themselves passively with respect to the geomagnetic field and thereby facilitate the bacteria’s search for optimal conditions within the sharp chemical gradients of the OATZ. The bacteria may also gain energy from the redox cycling of their ...

  10. Diversity of magnetotactic bacteria from a French Pristine Mediterranean Area

    OpenAIRE

    Fuduche, M.; A. Postec; Davidson, Sylvain; Chauvin, J P; Gales, G.; Hirschler-Rea, A.; Ollivier, Bernard; Wu, L F; Pradel, Nathalie

    2015-01-01

    Magnetotactic bacteria synthesize intracellular magnetite and/or greigite magnetosome crystals. They play a significant role in both iron and sulfur cycles in sedimentary aquatic environments. To get insight into the bio-geochemical contribution of MTB, more studies concerning their ecology and their distribution in diverse habitats are necessary. The MTB community of an oil-industry polluted area of the French Mediterranean coast has been previously investigated. Here, we investigate the MTB...

  11. REMANENCE MEASUREMENTS ON INDIVIDUAL MAGNETOTACTIC BACTERIA USING A PULSED MAGNETIC-FIELD

    NARCIS (Netherlands)

    PENNINGA, [No Value; DEWAARD, H; MOSKOWITZ, BM; BAZYLINSKI, DA; FRANKEL, RB

    1995-01-01

    We describe pulsed-magnetic-field remanence measurements of individual, killed, undisrupted cells of three different types of magnetotactic bacteria. The measurement technique involved the observation of aligned, individual magnetotactic bacteria with a light microscope as they were subjected to mag

  12. DIVERSITY AND MAGNETISM OF MAGNETOTACTIC BACTERIA IN LAKE WEIYANG NEAR XI'AN CITY%西安未央湖趋磁细菌多样性与磁学研究

    Institute of Scientific and Technical Information of China (English)

    陈海涛; 林巍; 王寅炤; 李金华; 陈冠军; 潘永信

    2013-01-01

    对西安郊区未央湖趋磁细菌的生物多样性和磁学性质进行了系统研究.光学和透射电子显微镜分析发现,未央湖趋磁细菌主要为杆菌,它们的磁小体多为子弹头形状并呈链状排列;磁学分析表明这些磁小体颗粒以单畴磁铁矿为主;并发现一类同时含有磁铁矿和胶黄铁矿磁小体的趋磁杆菌.基于16S rRNA基因的系统发育分析发现,未央湖趋磁细菌主要分布在变形菌门的δ-变形菌纲(75%)和α-变形菌纲(25%).本研究结果还有助于为利用趋磁细菌群落指示环境变化提供依据.%Magnetotactic bacteria are a group of morphologically and phylogenetically heterogenous prokaryotes which synthesize intracellular nano-sized magnetic crystals of magnetite ( Fe3O4) and/or greigite ( Fe3S4). Magnetotactic bacteria are ubiquitous in freshwater and marine environments. Most observed magnetotactic bacteria are affiliated with the Alphaproteobacteria, while bacteria in the Deltaproteobacteria, Gammaproteobacteria, phylum Nitrospira, and the candidate division OP3 are also discovered. In this study,the diversity and magnetic properties of magnetotactic bacteria collected from Lake Weiyang in Xi'an city (34°24′23. 96"N, 108°58′55. 51"E) , Shaanxi Province, were analyzed and characterized. Surface sediments ( 5cm to 10cm) were collected, and magnetotactic bacteria were magnetically enriched using the capillary racetrack method. Transmission electron microscopy analyses have revealed that rod-shaped bacteria containing bullet-shaped magnetsomes were the dominant group of magnetotactic bacteria in Lake Weiyang. Other kinds of magnetotactic bacteria,such as cocci and spirilla,were also observed. Interestingly, the energy dispersive x-rayspectrometer of transmission electron microscopy showed some rod-shaped bacteria were able to simultaneously biomineralize magnetite and greigite magnetosomes in a single cell, which is unusual in magnetotactic bacteria. The

  13. Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

    Science.gov (United States)

    Loehr, Johannes; Pfeiffer, Daniel; Schüler, Dirk; Fischer, Thomas M

    2016-04-21

    Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain. PMID:26972517

  14. Occurrence and microscopic analyses of multicellular magnetotactic prokaryotes from coastal sediments in the Yellow Sea

    Science.gov (United States)

    Zhou, Ke; Pan, Hongmiao; Zhang, Shengda; Yue, Haidong; Xiao, Tian; Wu, Longfei

    2011-03-01

    Multicellular magnetotactic prokaryotes (MMPs) are a group of aggregates composed of 7-45 gram-negative cells synthesizing intracellular magnetic crystals. Although they are thought to be globally distributed, MMPs have been observed only in marine environments in America and Europe. Most MMPs share a rosette-like morphology and biomineralize iron sulfide crystals. In the present study, abundant MMPs were observed, with a density of 26 ind./cm3, in the sediments of a coastal lagoon, Lake Yuehu, in the Yellow Sea. Optical microscopy showed that all of them were rosette shaped with a diameter of 5.5±0.8 μm. Transmission electron microscopy revealed that these MMPs were composed of 10-16 ovoid cells and flagellated peritrichously. High-resolution transmission electron microscopy and energy dispersive X-ray analysis indicated that they biomineralized bullet-shaped magnetite crystals in highly organized parallel chains within which the magnetosomes were oriented in the same direction. This is the first report of MMPs from Asia and demonstrates the ubiquitous distribution of MMPs.

  15. Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle

    Science.gov (United States)

    Chen, A. P.; Berounsky, V. M.; Chan, M. K.; Blackford, M. G.; Cady, C.; Moskowitz, B. M.; Kraal, P.; Lima, E. A.; Kopp, R. E.; Lumpkin, G. R.; Weiss, B. P.; Hesse, P.; Vella, N. G. F.

    2014-09-01

    Of the two nanocrystal (magnetosome) compositions biosynthesized by magnetotactic bacteria (MTB), the magnetic properties of magnetite magnetosomes have been extensively studied using widely available cultures, while those of greigite magnetosomes remain poorly known. Here we have collected uncultivated magnetite- and greigite-producing MTB to determine their magnetic coercivity distribution and ferromagnetic resonance (FMR) spectra and to assess the MTB-associated iron flux. We find that compared with magnetite-producing MTB cultures, FMR spectra of uncultivated MTB are characterized by a wider empirical parameter range, thus complicating the use of FMR for fossilized magnetosome (magnetofossil) detection. Furthermore, in stark contrast to putative Neogene greigite magnetofossil records, the coercivity distributions for greigite-producing MTB are fundamentally left-skewed with a lower median. Lastly, a comparison between the MTB-associated iron flux in the investigated estuary and the pyritic-Fe flux in the Black Sea suggests MTB play an important, but heretofore overlooked role in euxinic marine system iron cycle.

  16. Unexpected diversity in populations of the many-celled magnetotactic prokaryote.

    Science.gov (United States)

    Simmons, Sheri L; Edwards, Katrina J

    2007-01-01

    The many-celled magnetotactic prokaryote (MMP) is an uncultivated, highly motile aggregate of 10-30 cells containing numerous chains of greigite (Fe(3)S(4)) magnetosomes. It is unique to marine environments and is abundant in slightly sulfidic sediments of the Little Sippewissett salt marsh (Falmouth, MA). We sequenced 16s rDNA genes from a natural population of MMP and found five lineages separated by at least 5% sequence divergence. Fluorescent in situ hybridization probes for three of these lineages showed significant variation in their relative abundances across a seasonal cycle in marsh productivity. The MMP should therefore be considered a separate genus in the delta-proteobacteria rather than a single species as previously thought. All cells in each aggregate express identical SSU rRNAs, suggesting that the aggregates are composed of a single MMP phylotype. This observation supports a model of the MMP as comprised of clonal cells which reproduce by binary fission of the aggregate. PMID:17227425

  17. Diversity analysis of magnetotactic bacteria in Lake Miyun, northern China, by restriction fragment length polymorphism.

    Science.gov (United States)

    Lin, Wei; Li, Jinhua; Schüler, Dirk; Jogler, Christian; Pan, Yongxin

    2009-08-01

    Magnetotactic bacteria (MTB) synthesize intracellular nano-scale crystals of magnetite or greigite within magnetosomes. MTB are ubiquitous in limnic and marine environments. In order to understand the diversity of MTB better, sediment samples were examined from Lake Miyun near Beijing by restriction fragment length polymorphism (RFLP). First, in silico analysis was used to evaluate the effectiveness of 12 sets of restriction endonucleases for distinguishing MTB sequences retrieved from the GenBank database. It was found that the tested restriction endonucleases had different power in the ability to differentiate the operational taxonomic units (OTUs) of MTB. Specifically, of the 12 sets of enzymes, MspI plus RsaI was found to be the most effective for correctly differentiating the OTUs of selected MTB sequences and it could detect 16 OTUs with appropriate OTUmin and OTUmax values (96.7% and 97.7%, respectively). The MspI plus RsaI RFLP analysis was then utilized to investigate the diversity of MTB in Lake Miyun sediment and it identified 8 OTUs (74.5% of the whole library) as MTB. Among these, 5 were affiliated to Alphaproteobacteria, while the rest belonged to the Nitrospira phylum. Interestingly, OTUs C, D and I displayed 91.8-98.4% similarity to "Magnetobacterium bavaricum". Together, these results demonstrated that the MspI plus RsaI RFLP analysis was useful for studying the diversity and change in community composition of uncultivated MTB from environmental samples. PMID:19168303

  18. Occurrence and microscopic analyses of multicellular magnetotactic prokaryotes from coastal sediments in the Yellow Sea

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ke; PAN Hongmiao; ZHANG Shengda; YUE Haidong; XIAO Tian; WU Longfei

    2011-01-01

    Multicellular magnetotactic prokaryotes (MMPs) are a group of aggregates composed of 7-45 gram-negative cells synthesizing intracellular magnetic crystals. Although they are thought to be globally distributed, MMPs have been observed only in marine environments in America and Europe. Most MMPs share a rosette-like morphology and biomineralize iron sulfide crystals. In the present study, abundant MMPs were observed, with a density of 26 ind./cm3, in the sediments of a coastal lagoon, Lake Yuehu, in the Yellow Sea. Optical microscopy showed that all of them were rosette shaped with a diameter of 5.5±0.8 μm. Transmission electron microscopy revealed that these MMPs were composed of 10-16 ovoid cells and flagellated peritrichously. High-resolution transmission electron microscopy and energy dispersive X-ray analysis indicated that they biomineralized bullet-shaped magnetite crystals in highly organized parallel chains within which the magnetosomes were oriented in the same direction. This is the first report of MMPs from Asia and demonstrates the ubiquitous distribution of MMPs.

  19. Engineering the iron-oxidizing chemolithoautotroph Acidithiobacillus ferrooxidans for biochemical production.

    Science.gov (United States)

    Kernan, Timothy; Majumdar, Sudipta; Li, Xiaozheng; Guan, Jingyang; West, Alan C; Banta, Scott

    2016-01-01

    There is growing interest in developing non-photosynthetic routes for the conversion of CO2 to fuels and chemicals. One underexplored approach is the transfer of energy to the metabolism of genetically modified chemolithoautotrophic bacteria. Acidithiobacillus ferrooxidans is an obligate chemolithoautotroph that derives its metabolic energy from the oxidation of iron or sulfur at low pH. Two heterologous biosynthetic pathways have been expressed in A. ferrooxidans to produce either isobutyric acid or heptadecane from CO2 and the oxidation of Fe(2+). A sevenfold improvement in productivity of isobutyric acid was obtained through improved media formulations in batch cultures. Steady-state efficiencies were lower in continuous cultures, likely due to ferric inhibition. If coupled to solar panels, the photon-to-fuel efficiency of this proof-of-principle process approaches estimates for agriculture-derived biofuels. These efforts lay the foundation for the utilization of this organism in the exploitation of electrical energy for biochemical synthesis. PMID:26174759

  20. Engineering the iron-oxidizing chemolithoautotroph Acidithiobacillus ferrooxidans for biochemical production.

    Science.gov (United States)

    Kernan, Timothy; Majumdar, Sudipta; Li, Xiaozheng; Guan, Jingyang; West, Alan C; Banta, Scott

    2016-01-01

    There is growing interest in developing non-photosynthetic routes for the conversion of CO2 to fuels and chemicals. One underexplored approach is the transfer of energy to the metabolism of genetically modified chemolithoautotrophic bacteria. Acidithiobacillus ferrooxidans is an obligate chemolithoautotroph that derives its metabolic energy from the oxidation of iron or sulfur at low pH. Two heterologous biosynthetic pathways have been expressed in A. ferrooxidans to produce either isobutyric acid or heptadecane from CO2 and the oxidation of Fe(2+). A sevenfold improvement in productivity of isobutyric acid was obtained through improved media formulations in batch cultures. Steady-state efficiencies were lower in continuous cultures, likely due to ferric inhibition. If coupled to solar panels, the photon-to-fuel efficiency of this proof-of-principle process approaches estimates for agriculture-derived biofuels. These efforts lay the foundation for the utilization of this organism in the exploitation of electrical energy for biochemical synthesis.

  1. Common ancestry of iron oxide- and iron-sulfide-based biomineralization in magnetotactic bacteria

    OpenAIRE

    Abreu, Fernanda; Cantão, Mauricio E; Nicolás, Marisa F; Barcellos, Fernando G; Morillo, Viviana; Almeida, Luiz GP; do Nascimento, Fabrícia F; Lefèvre, Christopher T; Dennis A. Bazylinski; R de Vasconcelos, Ana Tereza; Lins, Ulysses

    2011-01-01

    Magnetosomes are prokaryotic organelles produced by magnetotactic bacteria that consist of nanometer-sized magnetite (Fe3O4) or/and greigite (Fe3S4) magnetic crystals enveloped by a lipid bilayer membrane. In magnetite-producing magnetotactic bacteria, proteins present in the magnetosome membrane modulate biomineralization of the magnetite crystal. In these microorganisms, genes that encode for magnetosome membrane proteins as well as genes involved in the construction of the magnetite magnet...

  2. Construction of a microrobot system using magnetotactic bacteria for the separation of Staphylococcus aureus.

    Science.gov (United States)

    Chen, Chang-You; Chen, Chuan-Fang; Yi, Yong; Chen, Lin-Jie; Wu, Long-Fei; Song, Tao

    2014-10-01

    Magnetotactic bacteria exhibit superiority over other bacteria in fabricating microrobots because of their high motility and convenient controllability. In this study, a microrobot system is constructed using magnetotactic bacteria MO-1 and applied in pathogenic separation. The feasibility of this approach is demonstrated using Staphylococcus aureus. The MO-1 magnetotactic bacterial microrobots are fabricated by binding magnetotactic bacteria MO-1 with their rabbit anti-MO-1 polyclonal antibodies. The efficient binding of MO-1 magnetotactic bacterial microrobots to Staphylococcus aureus is corroborated by phase contrast microscopic and transmission electron microscopic analyses. Further, a microfluidic chip is designed and produced, and the MO-1 microrobots are magnetically guided toward a sample pool in the chip. In the sample pool, Staphylococcus aureus samples are loaded on the microrobots and then carried away to a detection pool in the chip, suggesting the microrobots have successfully carried and separated pathogen. This study is the first to demonstrate bacterial microrobots carrying pathogens and more importantly, it reflects the great potential of using magnetotactic bacteria to develop magnetic-guided, auto-propelled microrobots for pathogen isolation.

  3. Diffusion of magnetotactic bacterium in rotating magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Cebers, A., E-mail: aceb@tesla.sal.l [Department of Physics, University of Latvia, Zellu 8, Ri-bar ga, LV-1002 (Latvia)

    2011-02-15

    Swimming trajectory of a magnetotactic bacterium in a rotating magnetic field is a circle. Random reversals of the direction of the bacterium motion induces a random walk of the curvature center of the trajectory. In assumption of the distribution of the switching events according to the Poisson process the diffusion coefficient is calculated in dependence on the frequency of the rotating field and the characteristic time between the switching events. It is confirmed by the numerical simulation of the random walk of the bacterium in the rotating magnetic field. - Research highlights: Random switching of the flagella leads to diffusion of a bacterium in the field. Mean square displacement of the curvature center is proportional to time. Diffusion coefficient depends on the period of a rotating field. At zero frequency diffusion coefficient is the same as for a tumbling bacterium.

  4. Diversity of magnetotactic bacteria from a French pristine Mediterranean area.

    Science.gov (United States)

    Fuduche, Maxime; Postec, Anne; Davidson, Sylvain; Chauvin, Jean-Paul; Galès, Grégoire; Hirschler-Réa, Agnès; Ollivier, Bernard; Wu, Long-Fei; Pradel, Nathalie

    2015-04-01

    Magnetotactic bacteria synthesize intracellular magnetite and/or greigite magnetosome crystals. They play a significant role in both iron and sulfur cycles in sedimentary aquatic environments. To get insight into the bio-geochemical contribution of MTB, more studies concerning their ecology and their distribution in diverse habitats are necessary. The MTB community of an oil-industry polluted area of the French Mediterranean coast has been previously investigated. Here, we investigate the MTB community from coastal sediments of a Mediterranean pristine area using optical and transmission electron microscopy and phylogenetic analysis based on 16S rRNA gene sequences. A particularly high diversity of MTB was observed, with cocci phylogenetically distributed across the order Magnetococcales, including a novel cluster with sequences from the Mediterranean Sea designated as "Med group", and novel morphotypes. PMID:25487117

  5. Life with compass: diversity and biogeography of magnetotactic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei [Institute of Geology and Geophysics; Bazylinski, Dennis A [Ames Laboratory; Xiao, Tian [Chinese Academy of Sciences; Wu, Long-Fei [v; Pan, Yongxin [Institute of Geology and Geophysics

    2013-11-12

    Magnetotactic bacteria (MTB) are unique in their ability to synthesize intracellular nano-sized minerals of magnetite and/or greigite magnetosomes for magnetic orientation. Thus, they provide an excellent model system to investigate mechanisms of biomineralization. MTB play important roles in bulk sedimentary magnetism and have numerous versatile applications in paleoenvironmental reconstructions, and biotechnological and biomedical fields. Significant progress has been made in recent years in describing the composition of MTB communities and distribution through innovative cultivation-dependent and -independent techniques. In this review, the most recent contributions to the field of diversity and biogeography of MTB are summarized and reviewed. Emphasis is on the novel insights into various factors/processes potentially affecting MTB community distribution. An understanding of the present-day biogeography of MTB, and the ruling parameters of their spatial distribution, will eventually help us predict MTB community shifts with environmental changes and assess their roles in global iron cycling.

  6. Life with compass: diversity and biogeography of magnetotactic bacteria.

    Science.gov (United States)

    Lin, Wei; Bazylinski, Dennis A; Xiao, Tian; Wu, Long-Fei; Pan, Yongxin

    2014-09-01

    Magnetotactic bacteria (MTB) are unique in their ability to synthesize intracellular nano-sized minerals of magnetite and/or greigite magnetosomes for magnetic orientation. Thus, they provide an excellent model system to investigate mechanisms of biomineralization. MTB play important roles in bulk sedimentary magnetism and have numerous versatile applications in paleoenvironmental reconstructions, and biotechnological and biomedical fields. Significant progress has been made in recent years in describing the composition of MTB communities and distribution through innovative cultivation-dependent and -independent techniques. In this review, the most recent contributions to the field of diversity and biogeography of MTB are summarized and reviewed. Emphasis is on the novel insights into various factors/processes potentially affecting MTB community distribution. An understanding of the present-day biogeography of MTB, and the ruling parameters of their spatial distribution, will eventually help us predict MTB community shifts with environmental changes and assess their roles in global iron cycling. PMID:24148107

  7. Metagenome of a Versatile Chemolithoautotroph from Expanding Oceanic Dead Zones

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, David A.; Zaikova, Elena; Howes, Charles L.; Song, Young; Wright, Jody; Tringe, Susannah G.; Tortell, Philippe D.; Hallam, Steven J.

    2009-07-15

    Oxygen minimum zones (OMZs), also known as oceanic"dead zones", are widespread oceanographic features currently expanding due to global warming and coastal eutrophication. Although inhospitable to metazoan life, OMZs support a thriving but cryptic microbiota whose combined metabolic activity is intimately connected to nutrient and trace gas cycling within the global ocean. Here we report time-resolved metagenomic analyses of a ubiquitous and abundant but uncultivated OMZ microbe (SUP05) closely related to chemoautotrophic gill symbionts of deep-sea clams and mussels. The SUP05 metagenome harbors a versatile repertoire of genes mediating autotrophic carbon assimilation, sulfur-oxidation and nitrate respiration responsive to a wide range of water column redox states. Thus, SUP05 plays integral roles in shaping nutrient and energy flow within oxygen-deficient oceanic waters via carbon sequestration, sulfide detoxification and biological nitrogen loss with important implications for marine productivity and atmospheric greenhouse control.

  8. The biomineralization and fossilization of magnetotactic bacteria: Insights from experimental and field studies

    Science.gov (United States)

    Pan, Y.; LI, J.; Menguy, N.; Deng, C.; Kissel, C.; Liu, Q.; Zhu, R.

    2015-12-01

    Magnetotactic bacteria (MTB) are widespread prokaryotes which can navigate along the Earth's magnetic field lines and produce tens to hundreds of nanocrystals of magnetite (Fe3O4) or/and greigite (Fe3S4) aligned in chain(s) within a cell. The remains of MTB (i.e. magnetofossils) within geological records have therefore been considered as potential recorders of paleomagnetic, paleoenvironmental and ancient-life signals. These intracellularly-formed nanocrystals, called magnetosomes, generally have distinctively physical, chemical and crystallographic features from those magnetic minerals produced by abiotic or extracellular mineralization processes, and therefore could be distinguished by rock magnetic and electron microscopic approaches. However, identification and quantification of magnetofossils from sediments or sedimentary rocks are nevertheless not straightforward not only due to their tiny sizes, relatively low concentration, always mixing with abiotic magnetic minerals, but also the chain collapse and crystal maghemization during post-depositional processes. Comprehensive studies on the biomineralization and fossilization of magnetosomes are therefore essential for unambiguously identifying and quantitating magnetofossils from geologic samples. In this presentation, we summarize the biomineralization processes and magnetic properties of magnetosome chains within modern cultured and uncultured MTB. Experimental studies on the effects of the chain aligning and collapsing on the magnetic properties of magnetosomes are discussed, which give useful clues to understand the possible occurrence of magnetofossils within natural materials and their corresponding magnetic changes. Recent findings in magnetofossils from marine and lake sediments, showing how to identify magnetofossils from sediments by using the comprehensive rock magnetism, ferromagnetic resonance, and transmission electron microscopy approaches, as well as their implications for sedimentary magnetism

  9. Diversity and biogeography of present-day magnetotactic bacteria in eastern China

    Science.gov (United States)

    Lin, W.; Wang, Y.; Pan, Y.

    2012-12-01

    A number of microorganisms are able to biomineralize iron minerals. Among them, magnetotactic bacteria (MTB) mineralize intracellular membrane-enveloped magnetite and/or greigite, known as magnetosomes that help cells to swim along the Earth's magnetic field. In recent years, MTB have become an attractive model system for investigating the biogeomagnetism. The occurrence of MTB has been reported in aquatic environments from freshwater to marine ecosystems. And, fossil magnetosomes are found to be potential carriers of natural remanent magnetization and indicators of paleoenvironmental changes. However, their distribution across heterogeneous habitats remains unclear. Here we report the diversity and biogeography of MTB from more than 20 locations from freshwater to saline habitats in eastern China. Great morphological variability was observed in MTB communities through light and transmission electron microscope observation. Phylogenetic analysis based on 16S rRNA genes has revealed that identified MTB belonged to the Alphaproteobacteria, Deltaproteobacteria, Gammaproteobacteria, and the phylum Nitrospirae. The overall composition of MTB communities was compared, and we found a restricted distribution of MTB communities across a large spatial scale with pronounced endemicity. Variation partitioning analyses indicated that the biogeography of MTB is relatively more influenced by environmental factors (e.g., salinity, sulfate, total iron, Eh, and temperature) than geographic distance. More interestingly, we found, for the first time, that the strength of the Earth's magnetic field appears to influence the biogeography of MTB, implying an impact of geophysical effects on these microorganisms. Our results infer that MTB community represents a biogeographic distribution across the studied heterogeneous environments. Knowledge of the present-day MTB biogeography may be applied towards the reconstruction of paleo-environments and assessment of contribution of bacterial

  10. Killing of Staphylococcus aureus via Magnetic Hyperthermia Mediated by Magnetotactic Bacteria.

    Science.gov (United States)

    Chen, Changyou; Chen, Linjie; Yi, Yong; Chen, Chuanfang; Wu, Long-Fei; Song, Tao

    2016-01-01

    Staphylococcus aureus is a common hospital and household pathogen. Given the emergence of antibiotic-resistant derivatives of this pathogen resulting from the use of antibiotics as general treatment, development of alternative therapeutic strategies is urgently needed. Here, we assess the feasibility of killing S. aureus cells in vitro and in vivo through magnetic hyperthermia mediated by magnetotactic bacteria that possess magnetic nanocrystals and demonstrate magnetically steered swimming. The S. aureus suspension was added to magnetotactic MO-1 bacteria either directly or after coating with anti-MO-1 polyclonal antibodies. The suspensions were then subjected to an alternating magnetic field (AMF) for 1 h. S. aureus viability was subsequently assessed through conventional plate counting and flow cytometry. We found that approximately 30% of the S. aureus cells mixed with uncoated MO-1 cells were killed after AMF treatment. Moreover, attachment between the magnetotactic bacteria and S. aureus increased the killing efficiency of hyperthermia to more than 50%. Using mouse models, we demonstrated that magnetic hyperthermia mediated by antibody-coated magnetotactic MO-1 bacteria significantly improved wound healing. These results collectively demonstrated the effective eradication of S. aureus both in vitro and in vivo, indicating the potential of magnetotactic bacterium-mediated magnetic hyperthermia as a treatment for S. aureus-induced skin or wound infections. PMID:26873320

  11. Common ancestry of iron oxide- and iron-sulfide-based biomineralization in magnetotactic bacteria.

    Science.gov (United States)

    Abreu, Fernanda; Cantão, Mauricio E; Nicolás, Marisa F; Barcellos, Fernando G; Morillo, Viviana; Almeida, Luiz Gp; do Nascimento, Fabrícia F; Lefèvre, Christopher T; Bazylinski, Dennis A; R de Vasconcelos, Ana Tereza; Lins, Ulysses

    2011-10-01

    Magnetosomes are prokaryotic organelles produced by magnetotactic bacteria that consist of nanometer-sized magnetite (Fe(3)O(4)) or/and greigite (Fe(3)S(4)) magnetic crystals enveloped by a lipid bilayer membrane. In magnetite-producing magnetotactic bacteria, proteins present in the magnetosome membrane modulate biomineralization of the magnetite crystal. In these microorganisms, genes that encode for magnetosome membrane proteins as well as genes involved in the construction of the magnetite magnetosome chain, the mam and mms genes, are organized within a genomic island. However, partially because there are presently no greigite-producing magnetotactic bacteria in pure culture, little is known regarding the greigite biomineralization process in these organisms including whether similar genes are involved in the process. Here using culture-independent techniques, we now show that mam genes involved in the production of magnetite magnetosomes are also present in greigite-producing magnetotactic bacteria. This finding suggest that the biomineralization of magnetite and greigite did not have evolve independently (that is, magnetotaxis is polyphyletic) as once suggested. Instead, results presented here are consistent with a model in which the ability to biomineralize magnetosomes and the possession of the mam genes was acquired by bacteria from a common ancestor, that is, the magnetotactic trait is monophyletic. PMID:21509043

  12. Mass-dependent and -independent signature of Fe isotopes in magnetotactic bacteria.

    Science.gov (United States)

    Amor, Matthieu; Busigny, Vincent; Louvat, Pascale; Gélabert, Alexandre; Cartigny, Pierre; Durand-Dubief, Mickaël; Ona-Nguema, Georges; Alphandéry, Edouard; Chebbi, Imène; Guyot, François

    2016-05-01

    Magnetotactic bacteria perform biomineralization of intracellular magnetite (Fe3O4) nanoparticles. Although they may be among the earliest microorganisms capable of biomineralization on Earth, identifying their activity in ancient sedimentary rocks remains challenging because of the lack of a reliable biosignature. We determined Fe isotope fractionations by the magnetotactic bacterium Magnetospirillum magneticum AMB-1. The AMB-1 strain produced magnetite strongly depleted in heavy Fe isotopes, by 1.5 to 2.5 per mil relative to the initial growth medium. Moreover, we observed mass-independent isotope fractionations in (57)Fe during magnetite biomineralization but not in even Fe isotopes ((54)Fe, (56)Fe, and (58)Fe), highlighting a magnetic isotope effect. This Fe isotope anomaly provides a potential biosignature for the identification of magnetite produced by magnetotactic bacteria in the geological record.

  13. A cultured greigite-producing magnetotactic bacterium in a novel group of sulfate-reducing bacteria.

    Science.gov (United States)

    Lefèvre, Christopher T; Menguy, Nicolas; Abreu, Fernanda; Lins, Ulysses; Pósfai, Mihály; Prozorov, Tanya; Pignol, David; Frankel, Richard B; Bazylinski, Dennis A

    2011-12-23

    Magnetotactic bacteria contain magnetosomes--intracellular, membrane-bounded, magnetic nanocrystals of magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4))--that cause the bacteria to swim along geomagnetic field lines. We isolated a greigite-producing magnetotactic bacterium from a brackish spring in Death Valley National Park, California, USA, strain BW-1, that is able to biomineralize greigite and magnetite depending on culture conditions. A phylogenetic comparison of BW-1 and similar uncultured greigite- and/or magnetite-producing magnetotactic bacteria from freshwater to hypersaline habitats shows that these organisms represent a previously unknown group of sulfate-reducing bacteria in the Deltaproteobacteria. Genomic analysis of BW-1 reveals the presence of two different magnetosome gene clusters, suggesting that one may be responsible for greigite biomineralization and the other for magnetite. PMID:22194580

  14. Importance of Chemolithoautotrophic Production to Mobile Benthic Predators in the Gulf of Mexico

    Science.gov (United States)

    Morgan, E.; Macavoy, S.; Carney, R.

    2005-05-01

    The continental slope of the Gulf of Mexico is characterized by substantial hydrocarbon seepage which provides reduced energy sources, both CH4 and H2S, for chemolithoautotrophs existing as endosymbionts within mussels and tubeworms found in dense colonies that provide habitat for an array of endemic and colonial fauna. The extent of trophic export of chemosynthetic biomass to the seep communities and the surrounding benthic communities in the Gulf, however, remains an open question. To elucidate the nutritional associations between seep residents and the surrounding benthos the carbon, nitrogen and sulfur stable isotope values of the hagfish Eptatretus sp., the giant isopod Bathynomus giganteus and the predatory snail Phymorhyncus sp. were interpreted through a three source, dual isotope mixing model. The model was able to assess the contributions of different isotopic signals to a mixture and thus could distinguish between photosynthetic/phytodetritus based sources, methanotrophic sources and thiotrophic sources. Incorporation of chemosynthetic based food sources was minimal on the whole and species specific; however some of the organisms considered in this study did incorporate nutrition from chemolithoautotrophic sources.

  15. The Genome of Deep-Sea Vent Chemolithoautotroph Thiomicrospira crunogena XCL-2

    Energy Technology Data Exchange (ETDEWEB)

    Scott, K M; Sievert, S M; Abril, F N; Ball, L A; Barrett, C J; Blake, R A; Boller, A J; Chain, P G; Clark, J A; Davis, C R; Detter, C; Do, K F; Dobrinski, K P; Faza, B I; Fitzpatrick, K A; Freyermuth, S K; Harmer, T L; Hauser, L J; Hugler, M; Kerfeld, C A; Klotz, M G; Kong, W W; Land, M; Lapidus, A; Larimer, F W; Longo, D L; Lucas, S; Malfatti, S A; Massey, S E; Martin, D D; McCuddin, Z; Meyer, F; Moore, J L; Ocampo Jr., L H; Paul, J H; Paulsen, I T; Reep, D K; Ren, Q; Ross, R L; Sato, P Y; Thomas, P; Tinkham, L E; Zerugh, G T

    2007-01-10

    Presented here is the complete genome sequence of Thiomicrospira crunogena XCL-2, representative of ubiquitous chemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-sea hydrothermal vents. This gammaproteobacterium has a single chromosome (2,427,734 bp), and its genome illustrates many of the adaptations that have enabled it to thrive at vents globally. It has 14 methyl-accepting chemotaxis protein genes, including four that may assist in positioning it in the redoxcline. A relative abundance of CDSs encoding regulatory proteins likely control the expression of genes encoding carboxysomes, multiple dissolved inorganic nitrogen and phosphate transporters, as well as a phosphonate operon, which provide this species with a variety of options for acquiring these substrates from the environment. T. crunogena XCL-2 is unusual among obligate sulfur oxidizing bacteria in relying on the Sox system for the oxidation of reduced sulfur compounds. A 38 kb prophage is present, and a high level of prophage induction was observed, which may play a role in keeping competing populations of close relatives in check. The genome has characteristics consistent with an obligately chemolithoautotrophic lifestyle, including few transporters predicted to have organic allocrits, and Calvin-Benson-Bassham cycle CDSs scattered throughout the genome.

  16. Comparing chemolithoautotrophic subseafloor communities across geochemical gradients using meta-omics and RNA-SIP

    Science.gov (United States)

    Fortunato, C. S.; Huber, J. A.

    2015-12-01

    The chemolithoautotrophic microbial community of the rocky subseafloor potentially provides a large amount of organic carbon to the deep ocean, yet our understanding of the activity and metabolic complexity of subseafloor organisms remains poorly described. Past studies have shown that the taxonomic structure of subseafloor communities differs based on the geochemical signatures of individual vents. In this study, we expanded beyond phylogeny and used a combination of metagenomic, metatranscriptomic, and RNA-based stable isotope probing (RNA-SIP) analyses to identify the metabolic potential, expression patterns, and the active autotrophic players and genomic pathways present in venting fluids from Axial Seamount, an active submarine volcano off the coast of Oregon, USA. Low-temperature diffuse vent fluids from three hydrothermal vents, Marker 113, Marker 33, and Anemone, were filtered and preserved on the seafloor for metagenome and metatranscriptome analyses. Fluid for RNA-SIP was also collected and incubated shipboard with 13C-labeled sodium bicarbonate at 30ºC, 55ºC, and 80ºC for each vent. Taxonomically, Epsilonproteobacteria comprised a significant proportion of the community at all three vents, but each vent also had distinct groups that were abundant including SUP05 at Anemone and Methanococcus at Marker 113. Functionally, vents shared many metabolic processes including genes for denitrification, sulfur reduction and sulfur, hydrogen, and ammonium oxidation, which were present and expressed in similar abundance across all three vents. One metabolic difference between vents was the presence and expression of genes for methanogenesis, which were highly abundant and expressed at Marker 113, in lower abundance and expression at Marker 33, and not present at Anemone. RNA-SIP analysis is ongoing but initial results from Marker 113 revealed that at mesophilic, thermophilic, or hyperthemophilic temperatures, different genera and autotrophic metabolisms dominated

  17. Control of magnetite nanocrystal morphology in magnetotactic bacteria by regulation of mms7 gene expression.

    Science.gov (United States)

    Yamagishi, Ayana; Tanaka, Masayoshi; Lenders, Jos J M; Thiesbrummel, Jarla; Sommerdijk, Nico A J M; Matsunaga, Tadashi; Arakaki, Atsushi

    2016-01-01

    Living organisms can produce inorganic materials with unique structure and properties. The biomineralization process is of great interest as it forms a source of inspiration for the development of methods for production of diverse inorganic materials under mild conditions. Nonetheless, regulation of biomineralization is still a challenging task. Magnetotactic bacteria produce chains of a prokaryotic organelle comprising a membrane-enveloped single-crystal magnetite with species-specific morphology. Here, we describe regulation of magnetite biomineralization through controlled expression of the mms7 gene, which plays key roles in the control of crystal growth and morphology of magnetite crystals in magnetotactic bacteria. Regulation of the expression level of Mms7 in bacterial cells enables switching of the crystal shape from dumbbell-like to spherical. The successful regulation of magnetite biomineralization opens the door to production of magnetite nanocrystals of desired size and morphology. PMID:27417732

  18. Draft Genome Sequences of Two Magnetotactic Bacteria, Magnetospirillum moscoviense BB-1 and Magnetospirillum marisnigri SP-1

    Science.gov (United States)

    Koziaeva, Veronika V.; Dziuba, Marina V.; Ivanov, Timophey M.; Kuznetsov, Boris B.; Skryabin, Konstantin G.

    2016-01-01

    We report here the draft genome sequences of two recently isolated magnetotactic species, Magnetospirillum moscoviense BB-1 and Magnetospirillum marisnigri SP-1. The genome of M. moscoviense BB-1 has 4,164,497 bp, 65.2% G+C content, and comprises 207 contigs. The genome of M. marisnigri SP-1 consists of 131 contigs and has a length of 4,619,819 bp and 64.7% G+C content. PMID:27516508

  19. Draft Genome Sequences of Two Magnetotactic Bacteria, Magnetospirillum moscoviense BB-1 and Magnetospirillum marisnigri SP-1.

    Science.gov (United States)

    Koziaeva, Veronika V; Dziuba, Marina V; Ivanov, Timophey M; Kuznetsov, Boris B; Skryabin, Konstantin G; Grouzdev, Denis S

    2016-01-01

    We report here the draft genome sequences of two recently isolated magnetotactic species, Magnetospirillum moscoviense BB-1 and Magnetospirillum marisnigri SP-1. The genome of M. moscoviense BB-1 has 4,164,497 bp, 65.2% G+C content, and comprises 207 contigs. The genome of M. marisnigri SP-1 consists of 131 contigs and has a length of 4,619,819 bp and 64.7% G+C content. PMID:27516508

  20. Navigation with magnetic nanoparticles: magnetotactic bacteria and magnetic micro-robots

    Science.gov (United States)

    Klumpp, Stefan; Kiani, Bahareh; Vach, Peter; Faivre, Damien

    2015-10-01

    Magnetotactic bacteria navigate in the magnetic field of the Earth by aligning and swimming along field lines with the help of special magnetic organelles called magnetosomes. These organelles contain magnetic nanoparticles and are organized into chain structures in cells. Here we review recent work on the formation of these chains and provide some estimates of the magnetic interaction energies and the corresponding forces involved in this process. In addition, we briefly discuss the propulsion of synthetic micro- or nanopropellers based on magnetic nanoparticles.

  1. Magnetotactic bacteria in microcosms originating from the french mediterranean coast subjected to oil industry activities

    OpenAIRE

    A. Postec; Tapia, N.; A. Bernadac; Joseph, Manon; Davidson, Sylvain; Wu, L F; Ollivier, Bernard; Pradel, Nathalie

    2012-01-01

    Magnetotactic bacteria (MTB) mineralize nanosized magnetite or greigite crystals within cells and thus play an important role in the biogeochemical process. Despite decades of research, knowledge of MTB distribution and ecology, notably in areas subjected to oil industry activities, is still limited. In the present study, we investigated the presence of MTB in the Gulf of Fos, French Mediterranean coast, which is subjected to intensive oil industry activities. Microcosms containing sediments/...

  2. Production, Modification and Bio-Applications of Magnetic Nanoparticles Gestated by Magnetotactic Bacteria

    OpenAIRE

    Xie, Jin; Chen, Kai; Chen, Xiaoyuan

    2009-01-01

    Magnetotactic bacteria (MTB) were first discovered by Richard P. Blakemore in 1975, and this led to the discovery of a wide collection of microorganisms with similar features i.e., the ability to internalize Fe and convert it into magnetic nanoparticles, in the form of either magnetite (Fe3O4) or greigite (Fe3S4). Studies showed that these particles are highly crystalline, monodisperse, bioengineerable and have high magnetism that is comparable to those made by advanced synthetic methods, mak...

  3. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

    OpenAIRE

    Woehl, Taylor J.; Sanjay Kashyap; Emre Firlar; Teresa Perez-Gonzalez; Damien Faivre; Denis Trubitsyn; Dennis A. Bazylinski; Tanya Prozorov

    2014-01-01

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment....

  4. Short-term effects of temperature on the abundance and diversity of magnetotactic cocci

    OpenAIRE

    Lin, Wei; Wang, Yinzhao; Pan, Yongxin

    2012-01-01

    Temperature is one of the most important climate factors that can regulate the activity and growth of organisms. However, it is so far unclear how temperature influences the abundance and community composition of magnetotactic bacteria (MTB) that mineralize intracellular magnetite and/or greigite magnetosomes and play significant roles in the global iron cycling and sediment magnetization. To address this specific problem, in this study we have assessed the impact of temperature on freshwater...

  5. Crystal growth of bullet-shaped magnetite in magnetotactic bacteria of the Nitrospirae phylum

    OpenAIRE

    Li, Jinhua; Menguy, Nicolas; Gatel, Christophe; Boureau, Victor; Snoeck, Etienne; Patriarche, Gilles; Leroy, Eric; Pan, Yongxin

    2015-01-01

    Magnetotactic bacteria (MTB) are known to produce single-domain magnetite or greigite crystals within intracellular membrane organelles and to navigate along the Earth's magnetic field lines. MTB have been suggested as being one of the most ancient biomineralizing metabolisms on the Earth and they represent a fundamental model of intracellular biomineralization. Moreover, the determination of their specific crystallographic signature (e.g. structure and morphology) is essential for palaeoenvi...

  6. Magnetic microstructure of iron sulfide crystals in magnetotactic bacteria from off-axis electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, T. [Frontier Research System, Institute of Physical and Chemical Research (Japan); Department of Materials Science and Metallurgy, University of Cambridge (United Kingdom); Posfai, M. [Department of Earth and Environmental Sciences, University of Veszprem (Hungary); Chong, R.K.K. [Department of Materials Science and Metallurgy, University of Cambridge (United Kingdom); Finlayson, A.P. [Department of Materials Science and Metallurgy, University of Cambridge (United Kingdom); Dunin-Borkowski, R.E. [Department of Materials Science and Metallurgy, University of Cambridge (United Kingdom); Frontier Research System, Institute of Physical and Chemical Research (Japan); Frankel, R.B. [Department of Physics, California Polytechnic State University, San Luis Obispo, CA 93407 (United States)]. E-mail: rfrankel@calpoly.edu

    2006-10-01

    Transmission electron microscopy, off-axis electron holography and energy-selected imaging were used to study the crystallography, morphology, and magnetic microstructure of nanoscale greigite (Fe{sub 3}S{sub 4}) magnetosomes in magnetotactic bacteria from a sulfidic habitat. The greigite magnetosomes were organized in chains, but were less ordered than magnetite magnetosomes in other bacteria. Nevertheless, the magnetosomes comprise a permanent magnetic dipole, sufficient for magnetotaxis.

  7. Single-cell analysis reveals a novel uncultivated magnetotactic bacterium within the candidate division OP3.

    Science.gov (United States)

    Kolinko, Sebastian; Jogler, Christian; Katzmann, Emanuel; Wanner, Gerhard; Peplies, Jörg; Schüler, Dirk

    2012-07-01

    Magnetotactic bacteria (MTB) are a diverse group of prokaryotes that orient along magnetic fields using membrane-coated magnetic nanocrystals of magnetite (Fe(3) O(4) ) or greigite (Fe(3) S(4) ), the magnetosomes. Previous phylogenetic analysis of MTB has been limited to few cultivated species and most abundant members of natural populations, which were assigned to Proteobacteria and the Nitrospirae phyla. Here, we describe a single cell-based approach that allowed the targeted phylogenetic and ultrastructural analysis of the magnetotactic bacterium SKK-01, which was low abundant in sediments of Lake Chiemsee. Morphologically conspicuous single cells of SKK-01 were micromanipulated from magnetically collected multi-species MTB populations, which was followed by whole genome amplification and ultrastructural analysis of sorted cells. Besides intracellular sulphur inclusions, the large ovoid cells of SKK-01 harbour ∼175 bullet-shaped magnetosomes arranged in multiple chains that consist of magnetite as revealed by TEM and EDX analysis. Sequence analysis of 16 and 23S rRNA genes from amplified genomic DNA as well as fluorescence in situ hybridization assigned SKK-01 to the candidate division OP3, which so far lacks any cultivated representatives. SKK-01 represents the first morphotype that can be assigned to the OP3 group as well as the first magnetotactic member of the PVC superphylum. PMID:22003954

  8. Bacterial community succession during the enrichment of chemolithoautotrophic arsenite oxidizing bacteria at high arsenic concentrations

    Institute of Scientific and Technical Information of China (English)

    Nguyen Ai Le; Akiko Sato; Daisuke Inoue; Kazunari Sei; Satoshi Soda; Michihiko Ike

    2012-01-01

    To generate cost-effective technologies for the removal of arsenic from water,we developed an enrichment culture of chemolithoautotrophic arsenite oxidizing bacteria (CAOs) that could effectively oxidize widely ranging concentrations of As(Ⅲ) to As(Ⅴ).In addition,we attempted to elucidate the enrichment process and characterize the microbial composition of the enrichment culture.A CAOs enrichment culture capable of stably oxidizing As(Ⅲ) to As(Ⅴ) was successfully constructed through repeated batch cultivation for more than 700 days,during which time the initial As(Ⅲ) concentrations were increased in a stepwise manner from l to 10-12 mmol/L.As(Ⅲ) oxidation activity of the enrichment culture gradually improved,and 10-12 mmol/L As(Ⅲ) was almost completely oxidized within four days.Terminal restriction fragment length polymorphism analysis showed that the dominant bacteria in the enrichment culture varied drastically during the enrichment process depending on the As(Ⅲ) concentration.Isolation and characterization of bacteria in the enrichment culture revealed that the presence of multiple CAOs with various As(Ⅲ) oxidation abilities enabled the culture to adapt to a wide range of As(Ⅲ) concentrations.The CAOs enrichment culture constructed here may he useful for pretreatment of water from which arsenic is being removed.

  9. How Magnetotactic Bacteria Respond to Radiation Induced Stress and Damage: Comparative Genomics Evidences for Evolutionary Adaptation

    Science.gov (United States)

    Wang, Y.; Pan, Y.

    2015-12-01

    Solar radiation and galactic cosmic radiation is believed to be major restriction factors influencing survival and evolution of life. On planet earth, geomagnetic field along with atmosphere protect living beings from the harmful radiation. During a geomagnetic reversal or excursion, however, the efflux of charged particles on earth surface would increase as the shielding effect of magnetic field decrease. The stratospheric ozone can also be partially stripped away by solar wind when the strength of the field is weak, leading to an increasing ultraviolet radiation penetration to the earth surface. However, studies on the mechanism of radiation induced stress and damage are focused only on bacteria that have no response to magnetic field. This study was motivated by the need to fill the gap upon knowledge of that on magnetic field sensitive microorganism. Magnetotactic bacteria (MTB) are a group of microbes that are able to synthesis intracellular nano-sized magnetic particles (named magnetosomes). These chain-arranged magnetosomes help MTB sense and swim along the magnetic field to find their optimal living environment efficiently. In this paper, in silico prediction of stress and damage repair genes in response to different radiation were carried out on the complete genome of four nonmagnetotactic and four magnetotactic spirilla. In silico analyses of the genomes of magnetic field sensitive and non-sensitive spirilla revealed: 1) all strains contain genes for regulate responses superoxide and peroxide stress, DNA pyrimidine dimer and string breaks; 2) non-magnetotactic spirilla have more genes dealing with oxidative stress, while magnetotactic spirilla may benefit from magnetotaxis by swimming into oxic-anoxic zone away from oxidative stress and direct radiation damage; yet, the lipid hydroperoxide peroxidase gene in MTB may be responsible for possible ROS generated by the membrane enveloped magnetite magnetosome; 3) magnetotactic spirilla possess SOS rec

  10. Short-term effects of temperature on the abundance and diversity of magnetotactic cocci.

    Science.gov (United States)

    Lin, Wei; Wang, Yinzhao; Pan, Yongxin

    2012-03-01

    Temperature is one of the most important climate factors that can regulate the activity and growth of organisms. However, it is so far unclear how temperature influences the abundance and community composition of magnetotactic bacteria (MTB) that mineralize intracellular magnetite and/or greigite magnetosomes and play significant roles in the global iron cycling and sediment magnetization. To address this specific problem, in this study we have assessed the impact of temperature on freshwater magnetotactic cocci through laboratory microcosm simulations. Microcosms containing MTB were exposed to four constant temperatures ranging from 9°C to 37°C. After 10 days and 28 days of incubation, no significant differences in abundance were detected in microcosms at 9°C, 15°C, and 26°C (Student's t-test, P > 0.05); however, microcosms exposed to 37°C exhibited a significant decrease of magnetotactic cocci abundance (P < 0.05). Dendrogram analysis of community-amplified ribosomal DNA restriction analysis (community ARDRA) banding patterns distinguished the 37°C samples from samples at lower temperatures regardless of incubation periods. Furthermore, clone library analysis revealed that most of the operational taxonomic units (OTUs) detected in samples from 9°C to 26°C were absent from the 37°C microcosms, whereas six OTUs were exclusively detected in the 37°C samples. Community compositions from four incubation temperatures were further compared using statistical phylogenetic methods (UniFrac and LIBSHUFF), which revealed that the 37°C samples harbored phylogenetically distinct MTB communities compared to those found in 9°C, 15°C, and 26°C samples. Taken together, our results indicate that elevated temperature can influence the abundance and diversity of dominant members of magnetotactic cocci. This linkage further infers that the abundance and diversity of MTB (e.g., based on the fossil magnetosomes) may be useful in reconstruction of paleotemperature. PMID

  11. Collection, Isolation and Enrichment of Naturally Occurring Magnetotactic Bacteria from the Environment

    OpenAIRE

    Oestreicher, Zachery; Lower, Steven K.; Lin, Wei; Lower, Brian H.

    2012-01-01

    Magnetotactic bacteria (MTB) are aquatic microorganisms that were first notably described in 19751 from sediment samples collected in salt marshes of Massachusetts (USA). Since then MTB have been discovered in stratified water- and sediment-columns from all over the world2. One feature common to all MTB is that they contain magnetosomes, which are intracellular, membrane-bound magnetic nanocrystals of magnetite (Fe3O4) and/or greigite (Fe3S4) or both3, 4. In the Northern hemisphere, MTB are t...

  12. Coupled RNA-SIP and metatranscriptomics of active chemolithoautotrophic communities at a deep-sea hydrothermal vent.

    Science.gov (United States)

    Fortunato, Caroline S; Huber, Julie A

    2016-08-01

    The chemolithoautotrophic microbial community of the rocky subseafloor potentially provides a large amount of organic carbon to the deep ocean, yet our understanding of the activity and metabolic complexity of subseafloor organisms remains poorly described. A combination of metagenomic, metatranscriptomic, and RNA stable isotope probing (RNA-SIP) analyses were used to identify the metabolic potential, expression patterns, and active autotrophic bacteria and archaea and their pathways present in low-temperature hydrothermal fluids from Axial Seamount, an active submarine volcano. Metagenomic and metatranscriptomic results showed the presence of genes and transcripts for sulfur, hydrogen, and ammonium oxidation, oxygen respiration, denitrification, and methanogenesis, as well as multiple carbon fixation pathways. In RNA-SIP experiments across a range of temperatures under reducing conditions, the enriched (13)C fractions showed differences in taxonomic and functional diversity. At 30 °C and 55 °C, Epsilonproteobacteria were dominant, oxidizing hydrogen and primarily reducing nitrate. Methanogenic archaea were also present at 55 °C, and were the only autotrophs present at 80 °C. Correspondingly, the predominant CO2 fixation pathways changed from the reductive tricarboxylic acid (rTCA) cycle to the reductive acetyl-CoA pathway with increasing temperature. By coupling RNA-SIP with meta-omics, this study demonstrates the presence and activity of distinct chemolithoautotrophic communities across a thermal gradient of a deep-sea hydrothermal vent. PMID:26872039

  13. Genomic Insights into the Biomineralization and Environmental Function of Magnetotactic Bacteria

    Science.gov (United States)

    Lin, W.; Pan, Y.

    2015-12-01

    Microorganisms have populated the Earth for billions of years and their activities are important biologic forces shaping our planetary environments. Microbial biomineralization that selectively take up environmental elements (e.g., C, S, P, Fe) and synthesize minerals either intracellularly or extracellularly is of great interest. One of the most interesting examples of these types of organisms are magnetotactic bacteria (MTB), a polyphyletic group of prokaryotes that uptake iron from aquatic habitats and biomineralize intracellular nano-sized iron minerals of magnetite (Fe3O4) and/or greigite (Fe3S4), known as magnetosomes, and orientate and swim along the Earth's magnetic field. However, our knowledge on the biomineralization mechanisms of MTB and their environmental function remains very limited because the genomic information of most MTB is still not fully understood. By using metagenomic approaches, we have acquired genomic sequences of environmental MTB communities and discovered several conserved genomic fragments containing gene operons for magnetite or greigite biomineralization from Proteobacteria and Nitrospirae MTB. The comparison of these gene clusters has provided valuable insights into the origin and evolution of magnetosome biomineralization. We further obtained several draft genomes of uncultivated MTB belonging to the phylum Nitrospirae, which reveals a metabolic flexibility of this poorly understood magnetotactic group and indicates their considerable roles in the biogeochemical cycles of iron and sulfur.

  14. 趋磁细菌研究进展%Progress in studies on magnetotactic bacterium

    Institute of Scientific and Technical Information of China (English)

    孙秀兰; 刘伟伟; 张银志; 樊惠良; 陈文君

    2011-01-01

    Study on the magnetotactic bacterium in our country has a late start, with rare relevant reports.This paper mainly describes the research in this field at home and abroad, and the role of magnetotactic bacterium in food detection is also referred.The paper aims to help to promote the ongoing work in our country.It will lay a great basis for better development and utilization of this new environmental microorganism resources in the rapid and diversified detection methods of food.%趋磁细菌的研究在我国起步较晚,也少见有相关报道,本文主要介绍国内外这一领域的研究进展,并提到了趋磁细菌在食品检测中的应用,旨在促进国内此工作的开展,以便更好的开发利用这一新的环境微生物资源,为食品检测方法的快速化多样化奠定基础.

  15. Anomalous magnetic orientations of magnetosome chains in a magnetotactic bacterium: Magnetovibrio blakemorei strain MV-1.

    Directory of Open Access Journals (Sweden)

    Samanbir S Kalirai

    Full Text Available There is a good deal of published evidence that indicates that all magnetosomes within a single cell of a magnetotactic bacterium are magnetically oriented in the same direction so that they form a single magnetic dipole believed to assist navigation of the cell to optimal environments for their growth and survival. Some cells of the cultured magnetotactic bacterium Magnetovibrio blakemorei strain MV-1 are known to have relatively wide gaps between groups of magnetosomes that do not seem to interfere with the larger, overall linear arrangement of the magnetosomes along the long axis of the cell. We determined the magnetic orientation of the magnetosomes in individual cells of this bacterium using Fe 2p X-ray magnetic circular dichroism (XMCD spectra measured with scanning transmission X-ray microscopy (STXM. We observed a significant number of cases in which there are sub-chains in a single cell, with spatial gaps between them, in which one or more sub-chains are magnetically polarized opposite to other sub-chains in the same cell. These occur with an estimated frequency of 4.0±0.2%, based on a sample size of 150 cells. We propose possible explanations for these anomalous cases which shed insight into the mechanisms of chain formation and magnetic alignment.

  16. Synthesis of cellular organelles containing nano-magnets stunts growth of magnetotactic bacteria.

    Science.gov (United States)

    Naresh, Mohit; Hasija, Vivek; Sharma, Megha; Mittal, Aditya

    2010-07-01

    Magnetotactic bacteria are unique prokaryotes possessing the feature of cellular organelles called magnetosomes (membrane bound 40-50 nm vesicles entrapping a magnetic nano-crystal of magnetite or greigite). The obvious energetic impact of sophisticated eukaryotic-like membrane-bound organelle assembly on a presumably simpler prokaryotic system is not addressed in literature. In this work, while presenting evidence of direct coupling of carbon source consumption to synthesis of magnetosomes, we provide the first experimentally derived estimate of energy for organelle synthesis by Magnetospirillum gryphiswaldense as approximately 5 nJoules per magnetosome. Considering our estimate of approximately 0.2 microJoules per bacterial cell as the energy required for growth, we show that the energetic load of organelle synthesis results in stunting of cell growth. We also show that removal of soluble iron or sequestration by exogenous compounds in the bacterial cell cultures reverses the impact of the excess metabolic load exerted during magnetosomal synthesis. Thus, by taking advantage of the magnetotactic bacterial system we present the first experimental evidence for the presumed energy consumption during assembly of naturally occurring sub-100 nm intra-cellular organelles. PMID:21128392

  17. Magnetotactic bacteria in microcosms originating from the French Mediterranean Coast subjected to oil industry activities.

    Science.gov (United States)

    Postec, Anne; Tapia, Nicolas; Bernadac, Alain; Joseph, Manon; Davidson, Sylvain; Wu, Long-Fei; Ollivier, Bernard; Pradel, Nathalie

    2012-01-01

    Magnetotactic bacteria (MTB) mineralize nanosized magnetite or greigite crystals within cells and thus play an important role in the biogeochemical process. Despite decades of research, knowledge of MTB distribution and ecology, notably in areas subjected to oil industry activities, is still limited. In the present study, we investigated the presence of MTB in the Gulf of Fos, French Mediterranean coast, which is subjected to intensive oil industry activities. Microcosms containing sediments/water (1:2, v/v) from several sampling sites were monitored over several weeks. The presence of MTB was revealed in five of eight sites. Diverse and numerous MTB were revealed particularly from one site (named CAR), whilst temporal variations of a homogenous magnetotactic cocci population was shown within the LAV site microcosm over a 4-month period. Phylogenetic analysis revealed that they belonged to Alphaproteobacteria, and a novel genus from the LAV site was evidenced. Among the physicochemical parameters measured, a correlation was shown between the variation of MTB abundance in microcosms and the redox state of sulphur compounds. PMID:21766218

  18. Temporal variation of magnetotactic bacterial communities in two freshwater sediment microcosms.

    Science.gov (United States)

    Lin, Wei; Pan, Yongxin

    2010-01-01

    Magnetotactic bacteria (MTB), which can mineralize nanosized magnetite or greigite crystals within cells, play important roles in biogeochemical processes, for example iron and sulfur cycling, and depositional remanent magnetization acquisitions. Despite decades of research, the knowledge of MTB distribution and ecology is still limited. In the present study, we investigated the temporal variation of MTB communities in freshwater sediment microcosms based on 16S rRNA genes and unifrac analyses. Two microcosms (MY8 and MY11) collected from two separate sites in Lake Miyun (Beijing, China) were analyzed. The majority of retrieved sequences belonged to alphaproteobacterial magnetotactic cocci in both microcosms (representing 64.29% of clones from MY8 and 100% of clones from MY11), whereas so-called 'Magnetobacterium bavaricum'-like MTB affiliated within Nitrospira phylum were exclusively found in microcosm MY8. Over a 3-month period, the temporal variation of MTB communities was evident in both microcosms. In addition, the phylogenetic discrepancy of MTB communities between two microcosms is more prominent than that of the same microcosm at different times, implying adaptation of MTB phylogenetic lineages to specific microenvironments. Among the physical-chemical parameters measured, a strong correlation was shown between nitrate and the main genetic variability of MTB communities, indicating that nitrate may influence the occurrence of MTB phylogenetic lineages in natural environments. PMID:19909346

  19. Correlative Electron and Fluorescence Microscopy of Magnetotactic Bacteria in Liquid: Toward In Vivo Imaging

    Science.gov (United States)

    Woehl, Taylor J.; Kashyap, Sanjay; Firlar, Emre; Perez-Gonzalez, Teresa; Faivre, Damien; Trubitsyn, Denis; Bazylinski, Dennis A.; Prozorov, Tanya

    2014-10-01

    Magnetotactic bacteria biomineralize ordered chains of uniform, membrane-bound magnetite or greigite nanocrystals that exhibit nearly perfect crystal structures and species-specific morphologies. Transmission electron microscopy (TEM) is a critical technique for providing information regarding the organization of cellular and magnetite structures in these microorganisms. However, conventional TEM can only be used to image air-dried or vitrified bacteria removed from their natural environment. Here we present a correlative scanning TEM (STEM) and fluorescence microscopy technique for imaging viable cells of Magnetospirillum magneticum strain AMB-1 in liquid using an in situ fluid cell TEM holder. Fluorescently labeled cells were immobilized on microchip window surfaces and visualized in a fluid cell with STEM, followed by correlative fluorescence imaging to verify their membrane integrity. Notably, the post-STEM fluorescence imaging indicated that the bacterial cell wall membrane did not sustain radiation damage during STEM imaging at low electron dose conditions. We investigated the effects of radiation damage and sample preparation on the bacteria viability and found that approximately 50% of the bacterial membranes remained intact after an hour in the fluid cell, decreasing to ~30% after two hours. These results represent a first step toward in vivo studies of magnetite biomineralization in magnetotactic bacteria.

  20. Research on Sewage Treatment by Magnetotactic Microorganism%趋磁微生物处理污水研究

    Institute of Scientific and Technical Information of China (English)

    马伟

    2015-01-01

    指出了趋磁性微生物能够在缺氧和厌氧条件下,以硝酸盐作为最终电子受体,产生反硝化反应,进行脱氮处理。趋磁微生物可以利用硫酸盐、硫代硫酸盐为电子受体,进行硫化反应,去除污水中的硫。趋磁微生物在磁场的作用下,可以定向移动。增加污泥的沉淀速度,减少沉淀池的容积及沉淀时间。趋磁微生物处理重金属污水,能够很好地解分选,回收有用的重金属。对趋磁微生物处理污水进行了研究。%T he application research of magnetotactic microorganism has been paid more and more attention . Although the study of magnetotactic microorganism has a history of nearly 30 years ,there's no in -depth study on its function in sewage treatment ,the mechanism of removing pollutants and reaction conditions . Magnetotactic microorganism can use nitrate as the terminal electron acceptor under micro aerobic and anae‐robic conditions for denitrification and nitrogen removal .Magnetotactic microorganism can use sulfate and thiosulfate as electron acceptor for sulfuration reaction and the removal of sulfur in polluted water .Magne‐totactic microorganism ,under the effect of magnetic field ,can move directionally ,increase precipitation of pollutants and reduce the precipitation volume and time .The magnetotactic microorganism can deal with the sewage with heavy metal which can be decomposed effectively and then the useful part will be recycled .

  1. Whole-Genome Transcriptional Analysis of Chemolithoautotrophic Thiosulfate Oxidation by Thiobacillus denitrificans Under Aerobic vs. Denitrifying Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Beller, H R; Letain, T E; Chakicherla, A; Kane, S R; Legler, T C; Coleman, M A

    2006-04-22

    Thiobacillus denitrificans is one of the few known obligate chemolithoautotrophic bacteria capable of energetically coupling thiosulfate oxidation to denitrification as well as aerobic respiration. As very little is known about the differential expression of genes associated with ke chemolithoautotrophic functions (such as sulfur-compound oxidation and CO2 fixation) under aerobic versus denitrifying conditions, we conducted whole-genome, cDNA microarray studies to explore this topic systematically. The microarrays identified 277 genes (approximately ten percent of the genome) as differentially expressed using Robust Multi-array Average statistical analysis and a 2-fold cutoff. Genes upregulated (ca. 6- to 150-fold) under aerobic conditions included a cluster of genes associated with iron acquisition (e.g., siderophore-related genes), a cluster of cytochrome cbb3 oxidase genes, cbbL and cbbS (encoding the large and small subunits of form I ribulose 1,5-bisphosphate carboxylase/oxygenase, or RubisCO), and multiple molecular chaperone genes. Genes upregulated (ca. 4- to 95-fold) under denitrifying conditions included nar, nir, and nor genes (associated respectively with nitrate reductase, nitrite reductase, and nitric oxide reductase, which catalyze successive steps of denitrification), cbbM (encoding form II RubisCO), and genes involved with sulfur-compound oxidation (including two physically separated but highly similar copies of sulfide:quinone oxidoreductase and of dsrC, associated with dissimilatory sulfite reductase). Among genes associated with denitrification, relative expression levels (i.e., degree of upregulation with nitrate) tended to decrease in the order nar > nir > nor > nos. Reverse transcription, quantitative PCR analysis was used to validate these trends.

  2. Comparative genomic analysis of magnetotactic bacteria from the Deltaproteobacteria provides new insights into magnetite and greigite magnetosome genes required for magnetotaxis.

    Science.gov (United States)

    Lefèvre, Christopher T; Trubitsyn, Denis; Abreu, Fernanda; Kolinko, Sebastian; Jogler, Christian; de Almeida, Luiz Gonzaga Paula; de Vasconcelos, Ana Tereza R; Kube, Michael; Reinhardt, Richard; Lins, Ulysses; Pignol, David; Schüler, Dirk; Bazylinski, Dennis A; Ginet, Nicolas

    2013-10-01

    Magnetotactic bacteria (MTB) represent a group of diverse motile prokaryotes that biomineralize magnetosomes, the organelles responsible for magnetotaxis. Magnetosomes consist of intracellular, membrane-bounded, tens-of-nanometre-sized crystals of the magnetic minerals magnetite (Fe3O4) or greigite (Fe3S4) and are usually organized as a chain within the cell acting like a compass needle. Most information regarding the biomineralization processes involved in magnetosome formation comes from studies involving Alphaproteobacteria species which biomineralize cuboctahedral and elongated prismatic crystals of magnetite. Many magnetosome genes, the mam genes, identified in these organisms are conserved in all known MTB. Here we present a comparative genomic analysis of magnetotactic Deltaproteobacteria that synthesize bullet-shaped crystals of magnetite and/or greigite. We show that in addition to mam genes, there is a conserved set of genes, designated mad genes, specific to the magnetotactic Deltaproteobacteria, some also being present in Candidatus Magnetobacterium bavaricum of the Nitrospirae phylum, but absent in the magnetotactic Alphaproteobacteria. Our results suggest that the number of genes associated with magnetotaxis in magnetotactic Deltaproteobacteria is larger than previously thought. We also demonstrate that the minimum set of mam genes necessary for magnetosome formation in Magnetospirillum is also conserved in magnetite-producing, magnetotactic Deltaproteobacteria. Some putative novel functions of mad genes are discussed. PMID:23607663

  3. Production, Modification and Bio-Applications of Magnetic Nanoparticles Gestated by Magnetotactic Bacteria.

    Science.gov (United States)

    Xie, Jin; Chen, Kai; Chen, Xiaoyuan

    2009-04-01

    Magnetotactic bacteria (MTB) were first discovered by Richard P. Blakemore in 1975, and this led to the discovery of a wide collection of microorganisms with similar features i.e., the ability to internalize Fe and convert it into magnetic nanoparticles, in the form of either magnetite (Fe(3)O(4)) or greigite (Fe(3)S(4)). Studies showed that these particles are highly crystalline, monodisperse, bioengineerable and have high magnetism that is comparable to those made by advanced synthetic methods, making them candidate materials for a broad range of bio-applications. In this review article, the history of the discovery of MTB and subsequent efforts to elucidate the mechanisms behind the magnetosome formation are briefly covered. The focus is on how to utilize the knowledge gained from fundamental studies to fabricate functional MTB nanoparticles (MTB-NPs) that are capable of tackling real biomedical problems. PMID:20631916

  4. Greigite-producing Magnetotactic Bacteria in the Freshwater Moat of Xi'an City, China

    Science.gov (United States)

    Wang, Y.; Lin, W.; Li, J.; Pan, Y.

    2012-12-01

    Magnetotactic bacteria (MTB) are a group of morphologically and phylogentically heterogenous prokaryotes which usually mineralize intracellular membrane-enclosed and nano-sized magnetic crystals of magnetite (Fe3O4). In this study, we investigated the MTB diversity in a freshwater moat of Xi'an city, northwest of China based on transmission electron microscopy (TEM),16S rRNA gene analysis, and fluorescence in situ hybridization. TEM observation revealed different morphologies of MTB cells including cocci, spirilla, helical to vibrioid bacteria, and rod-shaped bacteria. Among these MTB, novel rod-shaped magnetotactic bacteria, which synthesized solely irregular rectangular greigite (Fe3S4), or both irregular rectangular greigite magnetosomes and bullet shaped magnetite magnetosomes in an individual cell, were identified for the first time in a freshwater environment with a large number of populations. Phylogenetic analysis of 16S rRNA genes and fluorescence in situ hybridization revealed that these specific MTB belong to sulfate reducing bacteria in the Deltaproteobacteria. Compositions of magnetosome crystals were analyzed by energy dispersive X-ray spectroscopy, high resolution TEM, and fast Fourier transform patterns analyses. Although it is unknown at this stage the biologically controlled mineralization mechanism within these greigite-producing MTB, we hypothesize that these MTB may have two different magnetosome gene clusters and distinct mineralization mechanisms. The presence of greigite-producing MTB in freshwater environments implies that these bacteria can play important roles in the iron and sulfur biogeochemical cycling in habitats, and magnetosome greigite, if preserved, can be potential carriers of magnetic signals in sediments.

  5. MamA as a Model Protein for Structure-Based Insight into the Evolutionary Origins of Magnetotactic Bacteria

    OpenAIRE

    Zeytuni, Natalie; Cronin, Samuel; Lefèvre, Christopher T; Arnoux, Pascal; Baran, Dror; Shtein, Zvi; Davidov, Geula; Zarivach, Raz

    2015-01-01

    International audience MamA is a highly conserved protein found in magnetotactic bacteria (MTB), a diverse group of prokaryotes capable of navigating according to magnetic fields - an ability known as magnetotaxis. Questions surround the acquisition of this magnetic navigation ability; namely, whether it arose through horizontal or vertical gene transfer. Though its exact function is unknown, MamA surrounds the magnetosome, the magnetic organelle embedding a biomineralised nanoparticle and...

  6. Analysis of Magnetosome Chains in Magnetotactic Bacteria by Magnetic Measurements and Automated Image Analysis of Electron Micrographs

    OpenAIRE

    Katzmann, E.; Eibauer, M.; Lin, W.; Pan, Y.; Plitzko, J. M.; D. Schuler

    2013-01-01

    Magnetotactic bacteria (MTB) align along the Earth's magnetic field by the activity of intracellular magnetosomes, which are membrane-enveloped magnetite or greigite particles that are assembled into well-ordered chains. Formation of magnetosome chains was found to be controlled by a set of specific proteins in Magnetospirillum gryphiswaldense and other MTB. However, the contribution of abiotic factors on magnetosome chain assembly has not been fully explored. Here, we first analyzed the effe...

  7. Single-cell genomics reveals potential for magnetite and greigite biomineralization in an uncultivated multicellular magnetotactic prokaryote.

    Science.gov (United States)

    Kolinko, Sebastian; Richter, Michael; Glöckner, Frank-Oliver; Brachmann, Andreas; Schüler, Dirk

    2014-10-01

    For magnetic orientation, magnetotactic bacteria biosynthesize magnetosomes, which consist of membrane-enveloped magnetic nanocrystals of either magnetite (Fe3 O4 ) or greigite (Fe3 S4 ). While magnetite formation is increasingly well understood, much less is known about the genetic control of greigite biomineralization. Recently, two related yet distinct sets of magnetosome genes were discovered in a cultivated magnetotactic deltaproteobacterium capable of synthesizing either magnetite or greigite, or both minerals. This led to the conclusion that greigite and magnetite magnetosomes are synthesized by separate biomineralization pathways. Although magnetosomes of both mineral types co-occurred in uncultured multicellular magnetotactic prokaryotes (MMPs), so far only one type of magnetosome genes could be identified in the available genome data. The MMP Candidatus Magnetomorum strain HK-1 from coastal tidal sand flats of the North Sea (Germany) was analysed by a targeted single-cell approach. The draft genome assembly resulted in a size of 14.3 Mb and an estimated completeness of 95%. In addition to genomic features consistent with a sulfate-reducing lifestyle, we identified numerous genes putatively involved in magnetosome biosynthesis. Remarkably, most mam orthologues were present in two paralogous copies with highest similarity to either magnetite or greigite type magnetosome genes, supporting the ability to synthesize magnetite and greigite magnetosomes. PMID:25079475

  8. Genes and pathways for CO2 fixation in the obligate, chemolithoautotrophic acidophile, Acidithiobacillus ferrooxidans, Carbon fixation in A. ferrooxidans

    Directory of Open Access Journals (Sweden)

    Esparza Mario

    2010-08-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is chemolithoautotrophic γ-proteobacterium that thrives at extremely low pH (pH 1-2. Although a substantial amount of information is available regarding CO2 uptake and fixation in a variety of facultative autotrophs, less is known about the processes in obligate autotrophs, especially those living in extremely acidic conditions, prompting the present study. Results Four gene clusters (termed cbb1-4 in the A. ferrooxidans genome are predicted to encode enzymes and structural proteins involved in carbon assimilation via the Calvin-Benson-Bassham (CBB cycle including form I of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO, EC 4.1.1.39 and the CO2-concentrating carboxysomes. RT-PCR experiments demonstrated that each gene cluster is a single transcriptional unit and thus is an operon. Operon cbb1 is divergently transcribed from a gene, cbbR, encoding the LysR-type transcriptional regulator CbbR that has been shown in many organisms to regulate the expression of RubisCO genes. Sigma70-like -10 and -35 promoter boxes and potential CbbR-binding sites (T-N11-A/TNA-N7TNA were predicted in the upstream regions of the four operons. Electrophoretic mobility shift assays (EMSAs confirmed that purified CbbR is able to bind to the upstream regions of the cbb1, cbb2 and cbb3 operons, demonstrating that the predicted CbbR-binding sites are functional in vitro. However, CbbR failed to bind the upstream region of the cbb4 operon that contains cbbP, encoding phosphoribulokinase (EC 2.7.1.19. Thus, other factors not present in the assay may be required for binding or the region lacks a functional CbbR-binding site. The cbb3 operon contains genes predicted to encode anthranilate synthase components I and II, catalyzing the formation of anthranilate and pyruvate from chorismate. This suggests a novel regulatory connection between CO2 fixation and tryptophan biosynthesis. The presence of a form II Rubis

  9. Thiocyanate hydrolase, the primary enzyme initiating thiocyanate degradation in the novel obligately chemolithoautotrophic halophilic sulfur-oxidizing bacterium Thiohalophilus thiocyanoxidans.

    Science.gov (United States)

    Bezsudnova, Ekaterina Yu; Sorokin, Dimitry Yu; Tikhonova, Tamara V; Popov, Vladimir O

    2007-12-01

    Thiohalophilus thiocyanoxidans is a first halophilic sulfur-oxidizing chemolithoautotrophic bacterium capable of growth with thiocyanate as an electron donor at salinity up to 4 M NaCl. The cells, grown with thiocyanate, but not with thiosulfate, contained an enzyme complex hydrolyzing thiocyanate to sulfide and ammonia under anaerobic conditions with carbonyl sulfide as an intermediate. Despite the fact of utilization of the , high cyanase activity was also detected in thiocyanate-induced cells. Three-stage column chromotography resulted in a highly purified thiocyanate-hydrolyzing protein with an apparent molecular mass of 140 kDa that consists of three subunits with masses 17, 19 and 29 kDa. The enzyme is a Co,Fe-containing protein resembling on its function and subunit composition the enzyme thiocyanate hydrolase from the Betaproteobacterium Thiobacillus thioparus. Cyanase, copurified with thiocyanate hydrolase, is a bisubstrate multisubunit enzyme with an apparent subunit molecular mass of 14 kDa. A possible role of cyanase in thiocyanate degradation by T. thiocyanoxidans is discussed.

  10. Thiobacter subterraneus gen. nov., sp. nov., an obligately chemolithoautotrophic, thermophilic, sulfur-oxidizing bacterium from a subsurface hot aquifer.

    Science.gov (United States)

    Hirayama, Hisako; Takai, Ken; Inagaki, Fumio; Nealson, Kenneth H; Horikoshi, Koki

    2005-01-01

    A novel, thermophilic, obligately chemolithoautotrophic, sulfur/thiosulfate-oxidizing bacterium was isolated from subsurface geothermal aquifer water (temperature approximately 70 degrees C) in the Hishikari gold mine, Japan. Cells of the isolate, designated strain C55T, were motile, straight rods with a single polar flagellum. Growth was observed at temperatures between 35 and 62 degrees C (optimum 50-55 degrees C; 60 min doubling time) and pH between 5.2 and 7.7 (optimum pH 6.5-7.0). High growth rate of strain C55T was observed on either thiosulfate or elemental sulfur as a sole energy source, with molecular oxygen as the only electron acceptor. None of the organic compounds tested supported or stimulated growth of strain C55T. The G+C content of the genomic DNA was 66.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain C55T was affiliated to the beta-Proteobacteria, but was distantly related to recognized genera. On the basis of its physiological and molecular properties, strain C55T (=JCM12421T=DSM 16629T=ATCC BAA-941T) is proposed as the type strain of Thiobacter subterraneus gen. nov., sp. nov.

  11. Complete genome sequence of the facultatively chemolithoautotrophic and methylotrophic alpha Proteobacterium Starkeya novella type strain (ATCC 8093T)

    Energy Technology Data Exchange (ETDEWEB)

    Kappler, Ulrike [University of Queensland, The, Brisbane, Queensland, Australia; Davenport, Karen W. [Los Alamos National Laboratory (LANL); Beatson, Scott [University of Queensland, The, Brisbane, Queensland, Australia; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Berry, Kerrie W. [U.S. Department of Energy, Joint Genome Institute; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Hammon, Nancy [U.S. Department of Energy, Joint Genome Institute; Dalin, Eileen [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Richardson, P M [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Tapia, Roxanne [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute

    2012-01-01

    Starkeya novella (Starkey 1934) Kelly et al. 2000 is a member of the family Xanthobacteraceae in the order Rhizobiales , which is thus far poorly characterized at the genome level. Cultures from this spe- cies are most interesting due to their facultatively chemolithoautotrophic lifestyle, which allows them to both consume carbon dioxide and to produce it. This feature makes S. novella an interesting model or- ganism for studying the genomic basis of regulatory networks required for the switch between con- sumption and production of carbon dioxide, a key component of the global carbon cycle. In addition, S. novella is of interest for its ability to grow on various inorganic sulfur compounds and several C1- compounds such as methanol. Besides Azorhizobium caulinodans, S. novella is only the second spe- cies in the family Xanthobacteraceae with a completely sequenced genome of a type strain. The cur- rent taxonomic classification of this group is in significant conflict with the 16S rRNA data. The ge- nomic data indicate that the physiological capabilities of the organism might have been underestimat- ed. The 4,765,023 bp long chromosome with its 4,511 protein-coding and 52 RNA genes was se- quenced as part of the DOE Joint Genome Institute Community Sequencing Program (CSP) 2008.

  12. Paracoccus bengalensis sp. nov., a novel sulfur-oxidizing chemolithoautotroph from the rhizospheric soil of an Indian tropical leguminous plant.

    Science.gov (United States)

    Ghosh, Wriddhiman; Mandal, Sukhendu; Roy, Pradosh

    2006-07-01

    Paracoccus versutus-like isolates from the rhizosphere of Clitoria ternatea, a slender leguminous herb (family--Papilionaceae), found ubiquitously in waste places and village forests of the Lower Gangetic plains of India, presented a case of graduated infraspecific variation that was capped by the identification of a new species Paracoccus bengalensis (type strain JJJ(T) = LMG 22700(T) = MTCC 7003(T)). The diverged phenetic and genetic structure of these sulfur-oxidizing chemolithoautotrophs presented a case of apparent nonconformity of 16S rRNA gene sequence similarities with results of DNA-DNA hybridization. Despite high 16S rRNA gene sequence similarity with P. versutus one of the newly isolated strains, viz., JJJ(T) was identified as a new species of Paracoccus by virtue of its explicitly low DNA-DNA hybridization (42-45%) with the type strain of the closest species P. versutus (), distinct G + C content (65.3 mol%), physiological and biochemical differences amounting to <60% phenetic similarity with strains of P. versutus as well as new isolates akin to the species. The newly described species also had a unique fatty acid profile that was distinguished by the absence of 18:1 omega9c, unique possession of Summed feature 3 (16:1omega7c & 15:0 iso 2-OH), 19:0 10 methyl, and a much higher concentration of 19:0 cycloomega8c. PMID:16824961

  13. Mesorhizobium thiogangeticum sp. nov., a novel sulfur-oxidizing chemolithoautotroph from rhizosphere soil of an Indian tropical leguminous plant.

    Science.gov (United States)

    Ghosh, Wriddhiman; Roy, Pradosh

    2006-01-01

    The bacterial strain SJT(T), along with 15 other mesophilic, neutrophilic and facultatively sulfur-oxidizing chemolithotrophic isolates, was isolated by enrichment on reduced sulfur compounds as the sole energy and electron source from soils immediately adjacent to the roots of Clitoria ternatea, a slender leguminous herb of the Lower Gangetic plains of India. Strain SJT(T) was able to oxidize thiosulfate and elemental sulfur for chemolithoautotrophic growth. 16S rRNA and recA gene sequence-based phylogenetic analyses showed that the Gram-negative rod-shaped bacterium belonged to the genus Mesorhizobium and was most closely related to Mesorhizobium loti, Mesorhizobium plurifarium, Mesorhizobium amorphae and Mesorhizobium chacoense. Unequivocally low 16S rRNA (<97 %) and recA (< or =88 %) gene sequence similarities to all existing species of the most closely related genera, a unique fatty acid profile, a distinct G+C content (59.6 mol%) and phenotypic characteristics all suggested that strain SJT(T) represents a novel species. DNA-DNA hybridization and SDS-PAGE analysis of whole-cell proteins also confirmed the taxonomic uniqueness of SJT(T). It is therefore proposed that isolate SJT(T) (= LMG 22697T = MTCC 7001T) be classified as the type strain of a novel species, Mesorhizobium thiogangeticum sp. nov. PMID:16403872

  14. From invagination to navigation: The story of magnetosome-associated proteins in magnetotactic bacteria.

    Science.gov (United States)

    Barber-Zucker, Shiran; Keren-Khadmy, Noa; Zarivach, Raz

    2016-02-01

    Magnetotactic bacteria (MTB) are a group of Gram-negative microorganisms that are able to sense and change their orientation in accordance with the geomagnetic field. This unique capability is due to the presence of a special suborganelle called the magnetosome, composed of either a magnetite or gregite crystal surrounded by a lipid membrane. MTB were first detected in 1975 and since then numerous efforts have been made to clarify the special mechanism of magnetosome formation at the molecular level. Magnetosome formation can be divided into several steps, beginning with vesicle invagination from the cell membrane, through protein sorting, followed by the combined steps of iron transportation, biomineralization, and the alignment of magnetosomes into a chain. The magnetosome-chain enables the sensing of the magnetic field, and thus, allows the MTB to navigate. It is known that magnetosome formation is tightly controlled by a distinctive set of magnetosome-associated proteins that are encoded mainly in a genomically conserved region within MTB called the magnetosome island (MAI). Most of these proteins were shown to have an impact on the magnetism of MTB. Here, we describe the process in which the magnetosome is formed with an emphasis on the different proteins that participate in each stage of the magnetosome formation scheme. PMID:26457474

  15. Characterization of a Single Magnetotactic Bacterial Species from Devil's Bathtub, Mendon Ponds Park, Honeoye Falls, NY

    Science.gov (United States)

    Wagner, C.; Tarduno, J. A.; Stein, A.; Sia, E.

    2015-12-01

    Magnetotactic bacteria (MTB) belong to a lineage of prokaryotic bacteria that synthesize magnetosomes, single domain magnetic particles (typically magnetite or greigite) with an average size of 50 nanometers. MTB utilize magnetosomes through magnetotaxis, the alignment and movement along magnetic field lines to navigate towards preferred environmental conditions. MTB are sensitive to different environments and are thought to exhibit varying magnetosome morphologies, compositions, sizes, and quantities in regards to the environments which they inhabit. These characteristics allow MTB and magnetofossils (preserved magnetosomes) to be used as modern/paleoenvironmental recorders and biomarkers for environmental change(s). Devil's Bathtub (Mendon Ponds Park, Honeoye Falls, NY) is a meromictic glacial kettle pond surrounded by deciduous tree cover. Here we examine one species of MTB based on prominence of this particular morphology at this locale. Magnetotaxis and morphology of this species have been observed using light microscopy. Micrographs have also been taken using Transmission Electron Microscopy (TEM) to verify cell morphology and to determine magnetosome morphology. TEM and magnetic hysteresis measurements were done to find and test the composition of magnetosomes. In this study we also focus on DNA sequencing and characterization of this MTB, as there are few MTB species which have been DNA sequenced successfully. Data from these experiments are directly applicable to this up-and-coming area of research as it will aid in the understanding and correlation of magnetosome and magnetofossils with environmental characteristics.

  16. Micrometric periodic assembly of magnetotactic bacteria and magnetic nanoparticles using audio tapes

    Science.gov (United States)

    Godoy, M.; Moreno, A. J.; Jorge, G. A.; Ferrari, H. J.; Antonel, P. S.; Mietta, J. L.; Ruiz, M.; Negri, R. M.; Pettinari, M. J.; Bekeris, V.

    2012-02-01

    We report micrometric periodic assembly of live and dead magnetotactic bacteria, Magnetospirillum magneticum AMB-1, which synthesize chains of magnetic nanoparticles inside their bodies, and of superparamagnetic Fe3O4 and ferromagnetic CoFe2O4 nanoparticles in aqueous suspensions using periodically magnetized audio tapes. The distribution of the stray magnetic field at the surface of the tapes was determined analytically and experimentally by magneto-optic imaging. Calculations showed that the magnetic field close to the tape surface was of the order of 100 mT, and the magnetic field gradient was larger than 1 T mm-1. Drops of aqueous solutions were deposited on the tapes, and bacteria and particles were trapped at locations where magnetic energy is minimized, as observed using conventional optical microscopy. Suspensions of M. magneticum AMB-1 treated with formaldehyde and kanamycin were studied, and patterns of trapped dead bacteria indicated that magnetic forces dominate over self-propelling forces in these experiments, in accordance with calculated values. The behavior of the different types of samples is discussed.

  17. The detection of magnetotactic bacteria in deep sea sediments from the east Pacific Manganese Nodule Province.

    Science.gov (United States)

    Dong, Yi; Li, Jinhua; Zhang, Wuchang; Zhang, Wenyan; Zhao, Yuan; Xiao, Tian; Wu, Long-Fei; Pan, Hongmiao

    2016-04-01

    Magnetotactic bacteria (MTB) are distributed ubiquitously in sediments from coastal environments to the deep sea. The Pacific Manganese Nodule Province contains numerous polymetallic nodules mainly composed of manganese, iron, cobalt, copper and nickel. In the present study we used Illumina MiSeq sequencing technology to assess the communities of putative MTB in deep sea surface sediments at nine stations in the east Pacific Manganese Nodule Province. A total of 402 sequence reads from MTB were classified into six operational taxonomic units (OTUs). Among these, OTU113 and OTU759 were affiliated with the genus Magnetospira, OTU2224 and OTU2794 were affiliated with the genus Magnetococcus and Magnetovibrio, respectively, OTU3017 had no known genus affiliation, and OTU2556 was most similar to Candidatus Magnetananas. Interestingly, OTU759 was widely distributed, occurring at all study sites. Magnetism measurements revealed that all sediments were dominated by low coercivity, non-interacting single domain magnetic minerals. Transmission electron microscopy confirmed that the magnetic minerals were magnetosomes. Our data suggest that diverse putative MTB are widely distributed in deep sea surface sediments from the east Pacific Manganese Nodule Province. PMID:26742990

  18. A novel species of ellipsoidal multicellular magnetotactic prokaryotes from Lake Yuehu in China.

    Science.gov (United States)

    Chen, Yi-Ran; Zhang, Rui; Du, Hai-Jian; Pan, Hong-Miao; Zhang, Wen-Yan; Zhou, Ke; Li, Jin-Hua; Xiao, Tian; Wu, Long-Fei

    2015-03-01

    Two morphotypes of multicellular magnetotactic prokaryotes (MMPs) have been identified: spherical (several species) and ellipsoidal (previously one species). Here, we report novel ellipsoidal MMPs that are ∼ 10 × 8 μm in size, and composed of about 86 cells arranged in six to eight interlaced circles. Each MMP was composed of cells that synthesized either bullet-shaped magnetite magnetosomes alone, or both bullet-shaped magnetite and rectangular greigite magnetosomes. They showed north-seeking magnetotaxis, ping-pong motility and negative phototaxis at a velocity up to 300 μm s(-1) . During reproduction, they divided along either their long- or short-body axes. For genetic analysis, we sorted the ellipsoidal MMPs with micromanipulation and amplified their genomes using multiple displacement amplification. We sequenced the 16S rRNA gene and found 6.9% sequence divergence from that of ellipsoidal MMPs, Candidatus Magnetananas tsingtaoensis and > 8.3% divergence from those of spherical MMPs. Therefore, the novel MMPs belong to different species and genus compared with the currently known ellipsoidal and spherical MMPs respectively. The novel MMPs display a morphological cell differentiation, implying a potential division of labour. These findings provide new insights into the diversity of MMPs in general, and contribute to our understanding of the evolution of multicellularity among prokaryotes. PMID:24725306

  19. Cell adhesion, multicellular morphology, and magnetosome distribution in the multicellular magnetotactic prokaryote Candidatus Magnetoglobus multicellularis.

    Science.gov (United States)

    Abreu, Fernanda; Silva, Karen Tavares; Leão, Pedro; Guedes, Iame Alves; Keim, Carolina Neumann; Farina, Marcos; Lins, Ulysses

    2013-06-01

    Candidatus Magnetoglobus multicellularis is an uncultured magnetotactic multicellular prokaryote composed of 17-40 Gram-negative cells that are capable of synthesizing organelles known as magnetosomes. The magnetosomes of Ca. M. multicellularis are composed of greigite and are organized in chains that are responsible for the microorganism's orientation along magnetic field lines. The characteristics of the microorganism, including its multicellular life cycle, magnetic field orientation, and swimming behavior, and the lack of viability of individual cells detached from the whole assembly, are considered strong evidence for the existence of a unique multicellular life cycle among prokaryotes. It has been proposed that the position of each cell within the aggregate is fundamental for the maintenance of its distinctive morphology and magnetic field orientation. However, the cellular organization of the whole organism has never been studied in detail. Here, we investigated the magnetosome organization within a cell, its distribution within the microorganism, and the intercellular relationships that might be responsible for maintaining the cells in the proper position within the microorganism, which is essential for determining the magnetic properties of Ca. M. multicellularis during its life cycle. The results indicate that cellular interactions are essential for the determination of individual cell shape and the magnetic properties of the organism and are likely directly associated with the morphological changes that occur during the multicellular life cycle of this species. PMID:23551897

  20. Different Species of Magnetotactic Bacteria Produce Magnetosomes in Surprisingly Diverse Ways

    Science.gov (United States)

    Rahn-Lee, L.; Komeili, A.

    2015-12-01

    Magnetotactic Bacteria (MTB) are major participants in bio-geomagnetism and serve as models for understanding magneto-reception by animals. These single-cell organisms construct magnetosome organelles consisting of chains of membrane-bound single-domain nano-crystals of magnetite or greigite that are uniform in size and shape. How are these organelles and crystals constructed? Our current model is based on studying the alpha-proteobacterial MTB, which produce magnetosomes containing cubo-octahedral magnetite crystals. However, different species of MTB synthesize crystals of different shapes and sizes that are arranged within the cell in different ways. For example, the delta-proteobacterial MTB Desulfovibrio magneticus RS-1 produces elongated, bullet-shaped magnetite crystals. By comparing the genes required for a magnetic response in RS-1 to our alpha-proteobacterial model, I identify new genes that are required for synthesizing these different magnetosomes. Surprisingly, the phenotypes of mutants that have a limited magnetic response indicate that the fundamental way that magnetosomes are produced and organized within the cell are different between the delta- and alpha-protobacterial MTBs. Upon closer examination of the properties of RS-1 magnetosomes, I suggest that we need to expand our understanding of what a magnetosome is.

  1. Crystal growth of bullet-shaped magnetite in magnetotactic bacteria of the Nitrospirae phylum.

    Science.gov (United States)

    Li, Jinhua; Menguy, Nicolas; Gatel, Christophe; Boureau, Victor; Snoeck, Etienne; Patriarche, Gilles; Leroy, Eric; Pan, Yongxin

    2015-02-01

    Magnetotactic bacteria (MTB) are known to produce single-domain magnetite or greigite crystals within intracellular membrane organelles and to navigate along the Earth's magnetic field lines. MTB have been suggested as being one of the most ancient biomineralizing metabolisms on the Earth and they represent a fundamental model of intracellular biomineralization. Moreover, the determination of their specific crystallographic signature (e.g. structure and morphology) is essential for palaeoenvironmental and ancient-life studies. Yet, the mechanisms of MTB biomineralization remain poorly understood, although this process has been extensively studied in several cultured MTB strains in the Proteobacteria phylum. Here, we show a comprehensive transmission electron microscopy (TEM) study of magnetic and structural properties down to atomic scales on bullet-shaped magnetites produced by the uncultured strain MYR-1 belonging to the Nitrospirae phylum, a deeply branching phylogenetic MTB group. We observed a multiple-step crystal growth of MYR-1 magnetite: initial isotropic growth forming cubo-octahedral particles (less than approx. 40 nm), subsequent anisotropic growth and a systematic final elongation along [001] direction. During the crystal growth, one major {111} face is well developed and preserved at the larger basal end of the crystal. The basal {111} face appears to be terminated by a tetrahedral-octahedral-mixed iron surface, suggesting dimensional advantages for binding protein(s), which may template the crystallization of magnetite. This study offers new insights for understanding magnetite biomineralization within the Nitrospirae phylum. PMID:25566884

  2. Salinity dependence of the distribution of multicellular magnetotactic prokaryotes in a hypersaline lagoon.

    Science.gov (United States)

    Martins, Juliana L; Silveira, Thaís S; Silva, Karen T; Lins, Ulysses

    2009-09-01

    Candidatus Magnetoglobus multicellularis is an unusual magnetotactic multicellular microorganism composed of a highly organized assemblage of gram-negative bacterial cells. In this work, the salinity dependence of Ca. M. multicellularis and its abundance in the hypersaline Araruama Lagoon, Brazil were studied. Viability experiments showed that Ca. M. multicellularis died in salinities upper than 55 per thousand and lower than 40 per thousand. Low salinities were also observed to modify the cellular assemblage. In microcosms prepared with different salinities, the microorganism grew better at intermediate salinities whereas in high or low salinities, the size of the population did not increase over time. The concentrations of Ca. M. multicellularis in the lagoon were related to salinity; sites with lower and higher salinities than the lagoon average contained less Ca. M. multicellularis. These results demonstrate the influence of salinity on the survival and distribution of Ca. M. multicellularis in the environment. In sediments, the abundance of Ca. M. multicellularis ranged from 0 to 103 microorganisms/ml, which represented 0.001% of the counts of total bacteria. The ability of Ca. M. multicellularis to accumulate iron and sulfur in high numbers of magnetosomes (up to 905 per microorganism) suggests that its impact on the sequestration of these elements (0.1% for biogenic bacterial iron) is not proportional to its abundance in the lagoon.

  3. Assemblies of magnetite nanoparticles extracted from magnetotactic bacteria: A magnetic study

    Science.gov (United States)

    Huízar-Félix, A. M.; Muñoz, D.; Orue, I.; Magén, C.; Ibarra, A.; Barandiarán, J. M.; Muela, A.; Fdez-Gubieda, M. L.

    2016-02-01

    Self-assembly has emerged as a suitable technique for tuning the properties of nanoparticles. In this work, we report the self-assembly of magnetosomes assisted by an external magnetic field. The magnetosomes are magnetite nanoparticles biomineralized by magnetotactic bacteria Magnetospirillum gryphiswaldense. These nanoparticles present truncated cubo-octahedral morphology with a mean diameter of ≈36 nm and are surrounded by a lipid bilayer membrane with a thickness ≈2-4 nm. The use of the appropriate preparation conditions, such as initial colloidal concentration and magnetic fields applied during deposition allowed us to obtain very reproducible self-assembled 2D patterns. Homogeneous ensembles of magnetosomes onto silicon and carbon surfaces are composed of elongated structures in the form of wide chains that cover a large area of the substrates. Transmission electron microscopy image and off-axis electron holography showed the map of the stray magnetic fields produced by these assemblies. The induced magnetic anisotropy was analyzed by measuring the hysteresis loops of the assemblies at different angles in a magneto-optical Kerr effect magnetometer. The evolution of the coercive field and remanence verified the presence of well-defined patterns. The experimental results were analyzed on the based of a biaxial model.

  4. Controlled Biomineralization of Magnetite (Fe(inf3)O(inf4)) and Greigite (Fe(inf3)S(inf4)) in a Magnetotactic Bacterium

    OpenAIRE

    Bazylinski, D. A.; Frankel, R B; Heywood, B. R.; Mann, S.; King, J. W.; Donaghay, P. L.; Hanson, A. K.

    1995-01-01

    A slowly moving, rod-shaped magnetotactic bacterium was found in relatively large numbers at and below the oxic-anoxic transition zone of a semianaerobic estuarine basin. Unlike all magnetotactic bacteria described to date, cells of this organism produce single-magnetic-domain particles of an iron oxide, magnetite (Fe(inf3)O(inf4)), and an iron sulfide, greigite (Fe(inf3)S(inf4)), within their magnetosomes. The crystals had different morphologies, being arrowhead or tooth shaped for the magne...

  5. 趋磁细菌多样性及其环境意义%DIVERSITY OF MAGNETOTACTIC BACTERIA AND ITS IMPLICATIONS FOR ENVIRONMENT

    Institute of Scientific and Technical Information of China (English)

    林巍; 潘永信

    2012-01-01

    趋磁细菌是一类特殊的微生物,它们在体内合成有生物膜包裹、粒度均一(35 ~ 120 nm)、结晶程度高、晶形特殊、呈链状排列的磁小体,其化学成分主要是磁铁矿( Fe3O4)或胶黄铁矿(Fe3S4),因此,它们能沿地磁场磁力线定向游弋.研究表明,趋磁细菌广泛分布在淡水和海洋环境中,细胞数量可达105~ 107个/ml,其多样性和地理分布与环境有密切关系.磁小体在趋磁细菌死后可以保存在沉积物中,化石磁小体对沉积物磁学性质有重要贡献,而且趋磁细菌活动在全球铁元素循环和维持生态系统功能等方面发挥重要作用.本文综述了近年来趋磁细菌多样性、地理分布格局、环境磁学以及古环境重建等方面的研究进展.值得指出的是,化石磁小体可作为重构古环境的生物标志物,应予以重视.%Magnetotactic bacteria ( MTB ) are a phylogenetically and morphologically diverse group of microorganisms which synthesize iron minerals of magnetite ( Fe3O4 ) and/or greigite( Fe3S4 ) within complex subcellular structures, the magnetosomes. It is widely accepted that, under the influence of the Earth's magnetic field, magnetosomes facilitate the navigation of MTB to their preferred microenvironments in chemically stratified aquatic environments. MTB are ubiquitous in various limnic and marine environments, including freshwater lakes, salt ponds, intertidal zones,mangrove swamps,and even hot springs. These bacteria are able to accumulate up to 2% ~ 4% iron by dry weight and therefore have been attributed as an important role in global iron cycling. 16S rRNA gene-based community analysis has revealed a great deal about the diversity of MTB. So far all known MTB are affiliated within the phylum Proteobacteria, phylum Nitrospirae, and candidate division 0P3. Recent studies have shown that the distribution and community structures of MTB represent a biogeographic distribution across heterogeneous environments

  6. Sub-micrometer-scale mapping of magnetite crystals and sulfur globules in magnetotactic bacteria using confocal Raman micro-spectrometry.

    Directory of Open Access Journals (Sweden)

    Stephan H K Eder

    Full Text Available The ferrimagnetic mineral magnetite Fe3O4 is biomineralized by magnetotactic microorganisms and a diverse range of animals. Here we demonstrate that confocal Raman microscopy can be used to visualize chains of magnetite crystals in magnetotactic bacteria, even though magnetite is a poor Raman scatterer and in bacteria occurs in typical grain sizes of only 35-120 nm, well below the diffraction-limited optical resolution. When using long integration times together with low laser power (<0.25 mW to prevent laser induced damage of magnetite, we can identify and map magnetite by its characteristic Raman spectrum (303, 535, 665 cm(-1 against a large autofluorescence background in our natural magnetotactic bacteria samples. While greigite (cubic Fe3S4; Raman lines of 253 and 351 cm(-1 is often found in the Deltaproteobacteria class, it is not present in our samples. In intracellular sulfur globules of Candidatus Magnetobacterium bavaricum (Nitrospirae, we identified the sole presence of cyclo-octasulfur (S8: 151, 219, 467 cm(-1, using green (532 nm, red (638 nm and near-infrared excitation (785 nm. The Raman-spectra of phosphorous-rich intracellular accumulations point to orthophosphate in magnetic vibrios and to polyphosphate in magnetic cocci. Under green excitation, the cell envelopes are dominated by the resonant Raman lines of the heme cofactor of the b or c-type cytochrome, which can be used as a strong marker for label-free live-cell imaging of bacterial cytoplasmic membranes, as well as an indicator for the redox state.

  7. Catabolic and anabolic energy for chemolithoautotrophs in deep-sea hydrothermal systems hosted in different rock types

    Science.gov (United States)

    Amend, Jan P.; McCollom, Thomas M.; Hentscher, Michael; Bach, Wolfgang

    2011-10-01

    Active deep-sea hydrothermal vents are hosted by a range of different rock types, including basalt, peridotite, and felsic rocks. The associated hydrothermal fluids exhibit substantial chemical variability, which is largely attributable to compositional differences among the underlying host rocks. Numerical models were used to evaluate the energetics of seven inorganic redox reactions (potential catabolisms of chemolithoautotrophs) and numerous biomolecule synthesis reactions (anabolism) in a representative sampling of these systems, where chemical gradients are established by mixing hydrothermal fluid with seawater. The wide ranging fluid compositions dictate demonstrable differences in Gibbs energies (Δ G r) of these catabolic and anabolic reactions in three peridotite-hosted, six basalt-hosted, one troctolite-basalt hybrid, and two felsic rock-hosted systems. In peridotite-hosted systems at low to moderate temperatures (10), hydrogen oxidation yields the most catabolic energy, but the oxidation of methane, ferrous iron, and sulfide can also be moderately exergonic. At higher temperatures, and consequent SW:HF mixing ratios anabolism in chemolithoautotrophs—represented here by the synthesis of amino acids, nucleotides, fatty acids, saccharides, and amines—were generally most favorable at moderate temperatures (22-32 °C) and corresponding SW:HF mixing ratios (˜15). In peridotite-hosted and the troctolite-basalt hybrid systems, Δ G r for primary biomass synthesis yielded up to ˜900 J per g dry cell mass. The energetics of anabolism in basalt- and felsic rock-hosted systems were far less favorable. The results suggest that in peridotite-hosted (and troctolite-basalt hybrid) systems, compared with their basalt (and felsic rock) counterparts, microbial catabolic strategies—and consequently variations in microbial phylotypes—may be far more diverse and some biomass synthesis may yield energy rather than imposing a high energetic cost.

  8. Genome-enabled studies of anaerobic, nitrate-dependent iron oxidation in the chemolithoautotrophic bacterium Thiobacillus denitrificans

    Directory of Open Access Journals (Sweden)

    Harry R Beller

    2013-08-01

    Full Text Available Thiobacillus denitrificans is a chemolithoautotrophic bacterium capable of anaerobic, nitrate-dependent U(IV and Fe(II oxidation, both of which can strongly influence the long-term efficacy of in situ reductive immobilization of uranium in contaminated aquifers. We previously identified two c-type cytochromes involved in nitrate-dependent U(IV oxidation in T. denitrificans and hypothesized that c-type cytochromes would also catalyze Fe(II oxidation, as they have been found to play this role in anaerobic phototrophic Fe(II-oxidizing bacteria. Here we report on efforts to identify genes associated with nitrate-dependent Fe(II oxidation, namely (a whole-genome transcriptional studies [using FeCO3, Fe2+, and U(IV oxides as electron donors under denitrifying conditions], (b Fe(II oxidation assays performed with knockout mutants targeting primarily highly expressed or upregulated c-type cytochromes, and (c random transposon-mutagenesis studies with screening for Fe(II oxidation. Assays of mutants for 26 target genes, most of which were c-type cytochromes, indicated that none of the mutants tested were significantly defective in nitrate-dependent Fe(II oxidation. The non-defective mutants included the c1-cytochrome subunit of the cytochrome bc1 complex (complex III, which has relevance to a previously proposed role for this complex in nitrate-dependent Fe(II oxidation and to current concepts of reverse electron transfer. A transposon mutant with a disrupted gene associated with NADH:ubiquinone oxidoreductase (complex I was ~35% defective relative to the wild-type strain; this strain was similarly defective in nitrate reduction with thiosulfate as the electron donor. Overall, our results indicate that nitrate-dependent Fe(II oxidation in T. denitrificans is not catalyzed by the same c-type cytochromes involved in U(IV oxidation, nor have other c-type cytochromes yet been implicated in the process.

  9. Statistical approach for the culture conditions optimization of magnetotactic bacteria for magnetic cells production

    Institute of Scientific and Technical Information of China (English)

    Li Wenbing; Yu Longjiang; Zhou Pengpeng

    2006-01-01

    The culture of Magnetospirillum magneticum WM-1 depends on several control factors that have great effect on the magnetic cells concentration. Investigation into the optimal culture conditions needs a large number of experiments. So it is desirable to minimize the number of experiments and maximize the information gained from them. The orthogonal design of experiments and mathematical statistical method are considered as effective methods to optimize the culture condition of magnetotactic bacteria WM-1 for high magnetic cells concentration. The effects of the four factors, such as pH value of medium, oxygen concentration of gas phase in the serum bottle, C:C (mtartaric acid: msuccinic acid) ratio and NaNO3 concentration, are simultaneously investigated by only sixteen experiments through the orthogonal design L16(44) method. The optimal culture condition is obtained. At the optimal culture condition ( pH 7.0, an oxygen concentration 4.0%, C: C (mtartaric acid:msuccinic acid) ratio 1:2 and NaNO3 100 mg l-1), the magnetic cells concentration is promoted to 6.5×107 cells ml-1, approximately 8.3% higher than that under the initial conditions. The pH value of medium is a very important factor for magnetic cells concentration. It can be proved that the orthogonal design of experiment is of 90% confidence. Ferric iron uptake follows Michaelis-Menten kinetics with a Km of 2.5 μM and a Vmax of 0.83 min-1.

  10. Dynamic Model and Motion Mechanism of Magnetotactic Bacteria with Two Lateral Flagellar Bundles

    Institute of Scientific and Technical Information of China (English)

    Cenyu Yang; Chuanfang Chen; Qiufeng Ma; Longfei Wu; Tao Song

    2012-01-01

    Magnetotactic Bacteria (MTB) propel themselves by rotating their flagella and swim along the magnetic field lines.To analyze the motion of MTB,MTB magneto-ovoid strain MO-1 cells,each with two bundles of flagella,were taken as research object.The six-degrees-of-freedom (6-DoF) dynamic model of MO-1 was established based on the Newton-Euler dynamic equations.In particular,the interaction between the flagellum and fluid was considered by the resistive force theory.The simulated motion trajectory of MTB was found to consist of two kinds of helices:small helices resulting from the imbalance of force due to flagellar rotation,and large helices arising from the different directions of the rotation axis of the cell body and the propulsion axis of the flagellum.The motion behaviours of MTB in various magnetic fields were studied,and the simulation results agree well with the experiment results.In addition,the rotation frequency of the flagella was estimated at 1100 Hz,which is consistent with the average rotation rate for Na+-driven flagellar motors.The included angle of the magnetosome chain was predicted at 40° that is located within 20° to 60° range of the observed results.The results indicate the correctness of the dynamic model,which may aid research on the operation and control of MTB-propelled micro-actuators.Meanwhile,the motion behaviours of MTB may inspire the development of micro-robots with new driving mechanisms.

  11. Biogeography of magnetotactic bacteria and its implications for the global iron cycle

    Science.gov (United States)

    Lin, W.; Pan, Y.

    2013-12-01

    A number of microorganisms biomineralize intracellular or extracellular iron minerals and play essential roles in the global iron cycling. One of the most interesting examples of these types of organisms are the magnetotactic bacteria (MTB), a polyphyletic group of prokaryotes that are able to uptake iron from environments and biomineralize intracellular nano-sized iron minerals of magnetite (Fe3O4) and/or greigite (Fe3S4), known as magnetosomes. Knowledge on their potential contributions to the biogeochemical cycle of iron remains unknown because the diversity and biogeography of MTB in nature are not fully understood. Over the past years, we have extensively investigated the diversity and distribution of MTB communities from freshwater to saline habitats. Several novel yet uncultivated MTB populations were identified and characterized. By comparing our results with publicly available dataset of MTB, we revealed that the composition of MTB communities represents a biogeographic distribution across globally heterogeneous environments, and both environmental heterogeneity and geographic distance play significant roles in shaping their community composition. Building on the knowledge on MTB biogeography, we could estimate the potential contributions of MTB to the global iron cycling, e.g., the annual yield of magnetite by lacustrine MTB is estimated to be no less than 5 × 10^6 kg; while, this estimate would pronouncedly increase to an order of 10^8 kg of magnetite per year if we consider MTB communities distributed in the oceans. Our results strongly suggest that MTB communities play important roles in the present-day global iron cycling and the deposition of iron formation through geological history. On the other hand, since magnetosomes are strain-specific and could be preserved in sediments (magnetofossils), biogeography of MTB will open new avenue to paleoenvironmental studies. More research involving the ecology of natural MTB will help us better understand the

  12. Collection, isolation and enrichment of naturally occurring magnetotactic bacteria from the environment.

    Science.gov (United States)

    Oestreicher, Zachery; Lower, Steven K; Lin, Wei; Lower, Brian H

    2012-01-01

    Magnetotactic bacteria (MTB) are aquatic microorganisms that were first notably described in 1975 from sediment samples collected in salt marshes of Massachusetts (USA). Since then MTB have been discovered in stratified water- and sediment-columns from all over the world. One feature common to all MTB is that they contain magnetosomes, which are intracellular, membrane-bound magnetic nanocrystals of magnetite (Fe3O4) and/or greigite (Fe3S4) or both. In the Northern hemisphere, MTB are typically attracted to the south end of a bar magnet, while in the Southern hemisphere they are usually attracted to the north end of a magnet. This property can be exploited when trying to isolate MTB from environmental samples. One of the most common ways to enrich MTB is to use a clear plastic container to collect sediment and water from a natural source, such as a freshwater pond. In the Northern hemisphere, the south end of a bar magnet is placed against the outside of the container just above the sediment at the sediment-water interface. After some time, the bacteria can be removed from the inside of the container near the magnet with a pipette and then enriched further by using a capillary racetrack and a magnet. Once enriched, the bacteria can be placed on a microscope slide using a hanging drop method and observed in a light microscope or deposited onto a copper grid and observed using transmission electron microscopy (TEM). Using this method, isolated MTB may be studied microscopically to determine characteristics such as swimming behavior, type and number of flagella, cell morphology of the cells, shape of the magnetic crystals, number of magnetosomes, number of magnetosome chains in each cell, composition of the nanomineral crystals, and presence of intracellular vacuoles. PMID:23183960

  13. Sub-micrometer-scale mapping of magnetite crystals and sulfur globules in magnetotactic bacteria using confocal Raman micro-spectrometry.

    Science.gov (United States)

    Eder, Stephan H K; Gigler, Alexander M; Hanzlik, Marianne; Winklhofer, Michael

    2014-01-01

    The ferrimagnetic mineral magnetite Fe3O4 is biomineralized by magnetotactic microorganisms and a diverse range of animals. Here we demonstrate that confocal Raman microscopy can be used to visualize chains of magnetite crystals in magnetotactic bacteria, even though magnetite is a poor Raman scatterer and in bacteria occurs in typical grain sizes of only 35-120 nm, well below the diffraction-limited optical resolution. When using long integration times together with low laser power (greigite (cubic Fe3S4; Raman lines of 253 and 351 cm(-1)) is often found in the Deltaproteobacteria class, it is not present in our samples. In intracellular sulfur globules of Candidatus Magnetobacterium bavaricum (Nitrospirae), we identified the sole presence of cyclo-octasulfur (S8: 151, 219, 467 cm(-1)), using green (532 nm), red (638 nm) and near-infrared excitation (785 nm). The Raman-spectra of phosphorous-rich intracellular accumulations point to orthophosphate in magnetic vibrios and to polyphosphate in magnetic cocci. Under green excitation, the cell envelopes are dominated by the resonant Raman lines of the heme cofactor of the b or c-type cytochrome, which can be used as a strong marker for label-free live-cell imaging of bacterial cytoplasmic membranes, as well as an indicator for the redox state. PMID:25233081

  14. Characterization and phylogenetic identification of a species of spherical multicellular magnetotactic prokaryotes that produces both magnetite and greigite crystals.

    Science.gov (United States)

    Zhang, Rui; Chen, Yi-Ran; Du, Hai-Jian; Zhang, Wen-Yan; Pan, Hong-Miao; Xiao, Tian; Wu, Long-Fei

    2014-09-01

    Magnetotactic bacteria (MTB) are a group of Gram-negative bacteria synthesizing magnetic crystals that allow them aligning along magnetic field lines. They have diverse morphologies including cocci, rods, vibrio, spirilla, and multicellular magnetotactic prokaryotes (MMPs). MMPs are composed of 10-57 cells with peritrichous flagella on their outer surfaces and swim as an entire unit. Here, we describe a species of spherical MMPs isolated from intertidal sediments of Lake Yuehu (Yellow Sea, China). They were mainly found in the subsurface layer of gray-black sediments. Microscopy revealed that these spherical MMPs were 5.6 ± 0.9 μm in diameter and composed of approximately 16-32 ovoid cells with a helical arrangement and peritrichous flagellation. High-resolution transmission electron microscopy showed that the MMPs contained both bullet-shaped magnetite and irregular greigite magnetosomes that were arranged in chains or clusters. These MMPs displayed typical escape motility and negative phototaxis. The 16S rRNA genes of micromanipulation-purified spherical MMPs were cloned and sequenced. Phylogenetic analysis revealed that the MMP species was affiliated with Deltaproteobacteria and displayed >2.8% sequence divergence with respect to previously reported MMPs. This is the first phylogenetic identification of a spherical MMP that produces both magnetite and greigite magnetosomes. PMID:25086260

  15. Comparative genomic analysis provides insights into the evolution and niche adaptation of marine Magnetospira sp. QH-2 strain.

    Science.gov (United States)

    Ji, Boyang; Zhang, Sheng-Da; Arnoux, Pascal; Rouy, Zoe; Alberto, François; Philippe, Nadège; Murat, Dorothée; Zhang, Wei-Jia; Rioux, Jean-Baptiste; Ginet, Nicolas; Sabaty, Monique; Mangenot, Sophie; Pradel, Nathalie; Tian, Jiesheng; Yang, Jing; Zhang, Lichen; Zhang, Wenyan; Pan, Hongmiao; Henrissat, Bernard; Coutinho, Pedro M; Li, Ying; Xiao, Tian; Médigue, Claudine; Barbe, Valérie; Pignol, David; Talla, Emmanuel; Wu, Long-Fei

    2014-02-01

    Magnetotactic bacteria (MTB) are capable of synthesizing intracellular organelles, the magnetosomes, that are membrane-bounded magnetite or greigite crystals arranged in chains. Although MTB are widely spread in various ecosystems, few axenic cultures are available, and only freshwater Magnetospirillum spp. have been genetically analysed. Here, we present the complete genome sequence of a marine magnetotactic spirillum, Magnetospira sp. QH-2. The high number of repeats and transposable elements account for the differences in QH-2 genome structure compared with other relatives. Gene cluster synteny and gene correlation analyses indicate that the insertion of the magnetosome island in the QH-2 genome occurred after divergence between freshwater and marine magnetospirilla. The presence of a sodium-quinone reductase, sodium transporters and other functional genes are evidence of the adaptive evolution of Magnetospira sp. QH-2 to the marine ecosystem. Genes well conserved among freshwater magnetospirilla for nitrogen fixation and assimilatory nitrate respiration are absent from the QH-2 genome. Unlike freshwater Magnetospirillum spp., marine Magnetospira sp. QH-2 neither has TonB and TonB-dependent receptors nor does it grow on trace amounts of iron. Taken together, our results show a distinct, adaptive evolution of Magnetospira sp. QH-2 to marine sediments in comparison with its closely related freshwater counterparts. PMID:23841906

  16. From Chemolithoautotrophs to Electrolithoautotrophs: CO2 Fixation by Fe(II-Oxidizing Bacteria Coupled with Direct Uptake of Electrons from Solid Electron Sources

    Directory of Open Access Journals (Sweden)

    Takumi eIshii

    2015-09-01

    Full Text Available At deep-sea vent systems, hydrothermal emissions rich in reductive chemicals replace solar energy as fuels to support microbial carbon assimilation. Until recently, all the microbial components at vent systems have been assumed to be fostered by the primary production of chemolithoautotrophs; however, both the laboratory and on-site studies demonstrated electrical current generation at vent systems and have suggested that a portion of microbial carbon assimilation is stimulated by the direct uptake of electrons from electrically conductive minerals. Here we show that chemolithoautotrophic Fe(II-oxidizing bacterium, Acidithiobacillus ferrooxidans, switches the electron source for carbon assimilation from diffusible Fe2+ ions to an electrode under the condition that electrical current is the only source of energy and electrons. Site-specific marking of a cytochrome aa3 complex (aa3 complex and a cytochrome bc1 complex (bc1 complex in viable cells demonstrated that the electrons taken directly from an electrode are used for O2 reduction via a down-hill pathway, which generates proton motive force that is used for pushing the electrons to NAD+ through a bc1 complex. Activation of carbon dioxide fixation by a direct electron uptake was also confirmed by the clear potential dependency of cell growth. These results reveal a previously unknown bioenergetic versatility of Fe(II-oxidizing bacteria to use solid electron sources and will help with understanding carbon assimilation of microbial components living in electronically conductive chimney habitats.

  17. Cetia pacifica gen. nov., sp. nov., a chemolithoautotrophic, thermophilic, nitrate-ammonifying bacterium from a deep-sea hydrothermal vent.

    Science.gov (United States)

    Grosche, Ashley; Sekaran, Hema; Pérez-Rodríguez, Ileana; Starovoytov, Valentin; Vetriani, Costantino

    2015-04-01

    A thermophilic, anaerobic, chemolithoautotrophic bacterium, strain TB-6(T), was isolated from a deep-sea hydrothermal vent located on the East Pacific Rise at 9° N. The cells were Gram-staining-negative and rod-shaped with one or more polar flagella. Cell size was approximately 1-1.5 µm in length and 0.5 µm in width. Strain TB-6(T) grew between 45 and 70 °C (optimum 55-60 °C), 0 and 35 g NaCl l(-1) (optimum 20-30 g l(-1)) and pH 4.5 and 7.5 (optimum pH 5.5-6.0). Generation time under optimal conditions was 2 h. Growth of strain TB-6(T) occurred with H2 as the energy source, CO2 as the carbon source and nitrate or sulfur as electron acceptors, with formation of ammonium or hydrogen sulfide, respectively. Acetate, (+)-d-glucose, Casamino acids, sucrose and yeast extract were not used as carbon and energy sources. Inhibition of growth occurred in the presence of lactate, peptone and tryptone under a H2/CO2 (80 : 20; 200 kPa) gas phase. Thiosulfate, sulfite, arsenate, selenate and oxygen were not used as electron acceptors. The G+C content of the genomic DNA was 36.8 mol%. Phylogenetic analysis of the 16S rRNA gene of strain TB-6(T) showed that this organism branched separately from the three most closely related genera, Caminibacter , Nautilia and Lebetimonas , within the family Nautiliaceae . Strain TB-6(T) contained several unique fatty acids in comparison with other members of the family Nautiliaceae . Based on experimental evidence, it is proposed that the organism represents a novel species and genus within the family Nautiliaceae , Cetia pacifica, gen. nov., sp. nov. The type strain is TB-6(T) ( = DSM 27783(T) = JCM 19563(T)). PMID:25604337

  18. Experimental investigation of magneto-aerotaxis on wild-type magnetotactic bacteria in sediment

    Science.gov (United States)

    Mao, X.; Egli, R.

    2012-12-01

    Magnetotactic bacteria (MB) synthesize chains of magnetic particles, called magnetosomes, which provide a magnetic dipole that passively aligns the cells along the geomagnetic field. Flagellar propulsion allows MB to swim straight along field lines in what is known as magnetotaxis. The flagellum rotation sense is controlled by the chemical environment, so that MB can efficiently move across chemically stratified environments to reach the so-called oxic-anoxic interface (OAI). This combination of oriented swimming controlled by chemical (oxygen) sensing is called magneto-aerotaxis (Frankel 1997). Experiments with MB cultures show that magnetic spirilla can change instantaneously the swimming direction, while the behaviour of cocci depends on a sort of 'internal state' dictated by their original location with respect to the OAI. Here, we present first results the magneto-aerotactic behaviour of wild-type MB living in microcosms created with sediment retrieved from lake Chiemsee (Bavaria, Germany). In these microcosms, a stable population of MB (mainly unidentified strains of cocci, and Magnetobacterium Bavaricum) occur in the upmost few cm below the sediment surface, with maximum concentrations just below the OAI. We tested the reaction of this MB population to changes in chemical conditions by putting the microcosm inside a glove box with controlled oxygen-free atmospheres (N2 and CO2). A new equilibrium was reached within few weeks, with the OAI first moving upward and then disappearing. The depth distribution and swimming direction of MB was tested during and after the formation of a new equilibrium. We were never able to observe swimming directions consistent with bacteria moving upward in the sediment, as it was the case with cultured cocci in Frankel [1997], even long time after the entire sediment column became completely anoxic. Nevertheless, the disappearance of the OAI was accompanied by a slight but significant decrease of the total MB population

  19. Elemental sulfur and thiosulfate disproportionation by Desulfocapsa sulfoexigens sp. nov., a new anaerobic bacterium isolated from marine surface sediment

    DEFF Research Database (Denmark)

    Finster, Kai; Liesack, Werner; Thamdrup, Bo

    1998-01-01

    A mesophilic, anaerobic, gram-negative bacterium, strain SB164P1, was enriched and isolated from oxidized marine surface sediment with elemental sulfur as the sole energy substrate in the presence of ferrihydrite. Elemental sulfur was disproportionated to hydrogen sulfide and sulfate. Growth...... chemolithoautotrophically exclusively by the disproportionation of inorganic sulfur compounds. Comparative 16S rDNA sequencing analysis placed strain SB164P1 into the delta subclass of the class Proteobacteria. Its closest relative is Desulfocapsa thiozymogenes, and slightly more distantly related are Desulfofustis...

  20. Flagellated Magnetotactic Bacteria as Controlled MRI-trackable Propulsion and Steering Systems for Medical Nanorobots Operating in the Human Microvasculature.

    Science.gov (United States)

    Martel, Sylvain; Mohammadi, Mahmood; Felfoul, Ouajdi; Lu, Zhao; Pouponneau, Pierre

    2009-04-01

    Although nanorobots may play critical roles for many applications in the human body such as targeting tumoral lesions for therapeutic purposes, miniaturization of the power source with an effective onboard controllable propulsion and steering system have prevented the implementation of such mobile robots. Here, we show that the flagellated nanomotors combined with the nanometer-sized magnetosomes of a single Magnetotactic Bacterium (MTB) can be used as an effective integrated propulsion and steering system for devices such as nanorobots designed for targeting locations only accessible through the smallest capillaries in humans while being visible for tracking and monitoring purposes using modern medical imaging modalities such as Magnetic Resonance Imaging (MRI). Through directional and magnetic field intensities, the displacement speeds, directions, and behaviors of swarms of these bacterial actuators can be controlled from an external computer.

  1. Magnetotactic bacterial response to Antarctic dust supply during the Palaeocene-Eocene thermal maximum

    NARCIS (Netherlands)

    Larrasoaña, J.C.; Roberts, A.P.; Chang, L.; Schellenberg, S.A.; Fitz Gerald, J.D.; Norris, R.D.; Zachos, J.C.

    2012-01-01

    Distinct magnetic properties of marine sediments that record the Palaeocene–Eocene thermal maximum (PETM) have been suggested to be due to a bacterial magnetofossil signal that is linked to enhanced weathering conditions during the PETM. We document the dominance of bacterial magnetite in deep-sea s

  2. Switching between Magnetotactic and Aerotactic Displacement Controls to Enhance the Efficacy of MC-1 Magneto-Aerotactic Bacteria as Cancer-Fighting Nanorobots

    Directory of Open Access Journals (Sweden)

    Sylvain Martel

    2016-05-01

    Full Text Available The delivery of drug molecules to tumor hypoxic areas could yield optimal therapeutic outcomes. This suggests that effective cancer-fighting micro- or nanorobots would require more integrated functionalities than just the development of directional propelling constructs which have so far been the main general emphasis in medical micro- and nanorobotic research. Development of artificial agents that would be most effective in targeting hypoxic regions may prove to be a very challenging task considering present technological constraints. Self-propelled, sensory-based and directionally-controlled agents in the form of Magnetotactic Bacteria (MTB of the MC-1 strain have been investigated as effective therapeutic nanorobots in cancer therapy. Following computer-based magnetotactic guidance to reach the tumor area, the microaerophilic response of drug-loaded MC-1 cells could be exploited in the tumoral interstitial fluid microenvironments. Accordingly, their swimming paths would be guided by a decreasing oxygen concentration towards the hypoxic regions. However, the implementation of such a targeting strategy calls for a method to switch from a computer-assisted magnetotactic displacement control to an autonomous aerotactic displacement control. In this way, the MC-1 cells will navigate to tumoral regions and, once there, target hypoxic areas through their microaerophilic behavior. Here we show not only how the magnitude of the magnetic field can be used for this purpose but how the findings could help determine the specifications of a future compatible interventional platform within known technological and medical constraints.

  3. Paleo-environmental study on the growth of magnetotactic bacteria and precipitation of magnetosomes in Chinese loess-paleosol sequences

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    405 samples were collected from L5-S5-L6 in consideration of obvious variations in susceptibility of the geological sections, which are section Xifeng in Gansu Province and section Duanjiapo in Shaanxi Province for study of magnetotactic bacteria (MB) and magnetosomes (MS)in Chinese loess-paleosol sequences. MB in each sample were observed by TEM after being cultured under 8-18℃, room temperature (RT), 25℃, 26℃ and 30℃ conditions. In general, MB are distributed widely in loess-paleosol sequences, fewer in loess layers with predomination of vibriod in shape. However, there are more MB in paleosol layers with morphological varieties such as roddish, vibriod and occasionally approximately coccus. The magnetosomes (MS) in MB of paleosol are usually arranged in chains along the cells. It was also found that MB growth and MS formation are associated with the environment in which MB live. It can be inferred from the distributions of MB and MS that the paleoclimates fluctuated during the formation of loess-paleosol sequences in the Chinese Loess Plateau. The climate became gradually warmer but displayed more frequent fluctuations from the northwest to the southeast of the Plateau.

  4. Analysis of magnetosome chains in magnetotactic bacteria by magnetic measurements and automated image analysis of electron micrographs.

    Science.gov (United States)

    Katzmann, E; Eibauer, M; Lin, W; Pan, Y; Plitzko, J M; Schüler, D

    2013-12-01

    Magnetotactic bacteria (MTB) align along the Earth's magnetic field by the activity of intracellular magnetosomes, which are membrane-enveloped magnetite or greigite particles that are assembled into well-ordered chains. Formation of magnetosome chains was found to be controlled by a set of specific proteins in Magnetospirillum gryphiswaldense and other MTB. However, the contribution of abiotic factors on magnetosome chain assembly has not been fully explored. Here, we first analyzed the effect of growth conditions on magnetosome chain formation in M. gryphiswaldense by electron microscopy. Whereas higher temperatures (30 to 35°C) and high oxygen concentrations caused increasingly disordered chains and smaller magnetite crystals, growth at 20°C and anoxic conditions resulted in long chains with mature cuboctahedron-shaped crystals. In order to analyze the magnetosome chain in electron microscopy data sets in a more quantitative and unbiased manner, we developed a computerized image analysis algorithm. The collected data comprised the cell dimensions and particle size and number as well as the intracellular position and extension of the magnetosome chain. The chain analysis program (CHAP) was used to evaluate the effects of the genetic and growth conditions on magnetosome chain formation. This was compared and correlated to data obtained from bulk magnetic measurements of wild-type (WT) and mutant cells displaying different chain configurations. These techniques were used to differentiate mutants due to magnetosome chain defects on a bulk scale. PMID:24096429

  5. Spatiotemporal distribution of the magnetotactic multicellular prokaryote Candidatus Magnetoglobus multicellularis in a Brazilian hypersaline lagoon and in microcosms.

    Science.gov (United States)

    Martins, Juliana L; Silveira, Thais S; Abreu, Fernanda; de Almeida, Fernando P; Rosado, Alexandre S; Lins, Ulysses

    2012-09-01

    Candidatus Magnetoglobus multicellularis is an unusual morphotype of magnetotactic prokaryotes. These microorganisms are composed of a spherical assemblage of gram-negative prokaryotic cells capable of swimming as a unit aligned along a magnetic field. While they occur in many aquatic habitats around the world, high numbers of Ca. M. multicellularis have been detected in Araruama Lagoon, a large hypersaline lagoon near the city of Rio de Janeiro, in Brazil. Here, we report on the spatiotemporal distribution of one such population in sediments of Araruama Lagoon, including its annual distribution and its abundance compared with the total bacterial community. In microcosm experiments, Ca. M. multicellularis was unable to survive for more than 45 days: the population density gradually decreased coinciding with a shift to the upper layers of the sediment. Nonetheless, Ca. M. multicellularis was detected throughout the year in all sites studied. Changes in the population density seemed to be related to the input of organic matter as well as to salinity. The population density of Ca. M. multicellularis did not correlate with the total bacterial counts; instead, changes in the microbial community structure altered their counts in the environment.

  6. Marine genomics

    DEFF Research Database (Denmark)

    Oliveira Ribeiro, Ângela Maria; Foote, Andrew D.; Kupczok, Anne;

    2016-01-01

    Marine ecosystems occupy 71% of the surface of our planet, yet we know little about their diversity. Although the inventory of species is continually increasing, as registered by the Census of Marine Life program, only about 10% of the estimated two million marine species are known. This lag...

  7. Insight into the assembly properties and functional organisation of the magnetotactic bacterial actin-like homolog, MamK.

    Directory of Open Access Journals (Sweden)

    Sanjiv Sonkaria

    Full Text Available Magnetotactic bacteria (MTB synthesize magnetosomes, which are intracellular vesicles comprising a magnetic particle. A series of magnetosomes arrange themselves in chains to form a magnetic dipole that enables the cell to orient itself along the Earth's magnetic field. MamK, an actin-like homolog of MreB has been identified as a central component in this organisation. Gene deletion, fluorescence microscopy and in vitro studies have yielded mechanistic differences in the filament assembly of MamK with other bacterial cytoskeletal proteins within the cell. With little or no information on the structural and behavioural characteristics of MamK outside the cell, the mamK gene from Magnetospirillium gryphiswaldense was cloned and expressed to better understand the differences in the cytoskeletal properties with its bacterial homologues MreB and acitin. Despite the low sequence identity shared between MamK and MreB (22% and actin (18%, the behaviour of MamK monitored by light scattering broadly mirrored that of its bacterial cousin MreB primarily in terms of its pH, salt, divalent metal-ion and temperature dependency. The broad size variability of MamK filaments revealed by light scattering studies was supported by transmission electron microscopy (TEM imaging. Filament morphology however, indicated that MamK conformed to linearly orientated filaments that appeared to be distinctly dissimilar compared to MreB suggesting functional differences between these homologues. The presence of a nucleotide binding domain common to actin-like proteins was demonstrated by its ability to function both as an ATPase and GTPase. Circular dichroism and structural homology modelling showed that MamK adopts a protein fold that is consistent with the 'classical' actin family architecture but with notable structural differences within the smaller domains, the active site region and the overall surface electrostatic potential.

  8. Marine biology

    International Nuclear Information System (INIS)

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index

  9. Marine biology

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  10. Marine Biomedicine

    Science.gov (United States)

    Bang, Frederik B.

    1977-01-01

    Describes early scientific research involving marine invertebrate pathologic processes that may have led to new insights into human disease. Discussed are inquiries of Metchnikoff, Loeb, and Cantacuzene (immunolgic responses in sea stars, horseshoe crabs, and marine worms, respectively). Describes current research stemming from these early…

  11. Magnet-Facilitated Selection of Electrogenic Bacteria from Marine Sediment

    Directory of Open Access Journals (Sweden)

    Larisa Kiseleva

    2015-01-01

    Full Text Available Some bacteria can carry out anaerobic respiration by depositing electrons on external materials, such as electrodes, thereby creating an electrical current. Into the anode chamber of microbial fuel cells (MFCs having abiotic air-cathodes we inoculated microorganisms cultured from a magnetic particle-enriched portion of a marine tidal sediment, reasoning that since some external electron acceptors are ferromagnetic, electrogenic bacteria should be found in their vicinity. Two MFCs, one inoculated with a mixed bacterial culture and the other with an axenic culture of a helical bacterium isolated from the magnetic particle enrichment, termed strain HJ, were operated for 65 d. Both MFCs produced power, with production from the mixed culture MFC exceeding that of strain HJ. Strain HJ was identified as a Thalassospira sp. by transmission electron microscopic analysis and 16S rRNA gene comparisons. An MFC inoculated with strain HJ and operated in open circuit produced 47% and 57% of the maximal power produced from MFCs inoculated with the known electrogen Geobacter daltonii and the magnetotactic bacterium Desulfamplus magnetomortis, respectively. Further investigation will be needed to determine whether bacterial populations associated with magnetic particles within marine sediments are enriched for electrogens.

  12. Pathways of carbon assimilation and ammonia oxidation suggested by environmental genomic analyses of marine Crenarchaeota.

    Directory of Open Access Journals (Sweden)

    Steven J Hallam

    2006-04-01

    Full Text Available Marine Crenarchaeota represent an abundant component of oceanic microbiota with potential to significantly influence biogeochemical cycling in marine ecosystems. Prior studies using specific archaeal lipid biomarkers and isotopic analyses indicated that planktonic Crenarchaeota have the capacity for autotrophic growth, and more recent cultivation studies support an ammonia-based chemolithoautotrophic energy metabolism. We report here analysis of fosmid sequences derived from the uncultivated marine crenarchaeote, Cenarchaeum symbiosum, focused on the reconstruction of carbon and energy metabolism. Genes predicted to encode multiple components of a modified 3-hydroxypropionate cycle of autotrophic carbon assimilation were identified, consistent with utilization of carbon dioxide as a carbon source. Additionally, genes predicted to encode a near complete oxidative tricarboxylic acid cycle were also identified, consistent with the consumption of organic carbon and in the production of intermediates for amino acid and cofactor biosynthesis. Therefore, C. symbiosum has the potential to function either as a strict autotroph, or as a mixotroph utilizing both carbon dioxide and organic material as carbon sources. From the standpoint of energy metabolism, genes predicted to encode ammonia monooxygenase subunits, ammonia permease, urease, and urea transporters were identified, consistent with the use of reduced nitrogen compounds as energy sources fueling autotrophic metabolism. Homologues of these genes, recovered from ocean waters worldwide, demonstrate the conservation and ubiquity of crenarchaeal pathways for carbon assimilation and ammonia oxidation. These findings further substantiate the likely global metabolic importance of Crenarchaeota with respect to key steps in the biogeochemical transformation of carbon and nitrogen in marine ecosystems.

  13. Marine Mammals.

    Science.gov (United States)

    Meith, Nikki

    Marine mammals have not only fascinated and inspired human beings for thousands of years, but they also support a big business by providing flesh for sea-borne factories, sustaining Arctic lifestyles and traditions, and attracting tourists to ocean aquaria. While they are being harpooned, bludgeoned, shot, netted, and trained to jump through…

  14. Marine localities

    NARCIS (Netherlands)

    Wagenaar Hummelinck, P.

    1977-01-01

    Some twenty-five years have passed since short descriptions were published of marine and saltpond habitats sampled in the Caribbean during three zoological collecting trips made by the author in 1930, 1936/37 and 1948/49 (these Studies, vol. 4, no. 17, 1953). Sampling of the shallow coastal waters o

  15. Interventional procedure based on nanorobots propelled and steered by flagellated magnetotactic bacteria for direct targeting of tumors in the human body.

    Science.gov (United States)

    Martel, Sylvain; Felfoul, Ouajdi; Mohammadi, Mahmood; Mathieu, Jean-Baptiste

    2008-01-01

    Flagellated bacteria used as bio-actuators may prove to be efficient propulsion mechanisms for future hybrid medical nanorobots when operating in the microvasculature. Here, we briefly describe a medical interventional procedure where flagellated bacteria and more specifically MC-1 Magnetotactic Bacteria (MTB) can be used to propel and steer micro-devices and nanorobots under computer control to reach remote locations in the human body. In particular, we show through experimental results the potential of using MTB-tagged robots to deliver therapeutic agents to tumors even the ones located in deep regions of the human body. We also show that such bacterial nanorobots can be tracked inside the human body for enhanced targeting under computer guidance using MRI as imaging modality. MTB can not only be guided and controlled directly towards a specific target, but we also show experimentally that these flagellated bacterial nanorobots can be propelled and steered in vivo deeply through the interstitial region of a tumor. The targeting efficacy is increased when combined with larger ferromagnetic micro-carriers being propelled by magnetic gradients generated by a MRI platform to carry and release nanorobots propelled by a single flagellated bacterium near the arteriocapillar entry. Based on the experimental data obtained and the experience gathered during several experiments conducted in vivo with this new approach, a general medical interventional procedure is briefly described here in a biomedical engineering context.

  16. Active Marine Station Metadata

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Active Marine Station Metadata is a daily metadata report for active marine bouy and C-MAN (Coastal Marine Automated Network) platforms from the National Data...

  17. Marine fungi: A critique

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, S.; Raghukumar, C.

    Obligate marine fungi, those which grow and sporulate exclusively under marine conditions, have received all the attention from marine mycologists. Fungi originating from freshwater, or terrestrial environment and capable of growth and sporulation...

  18. Marine Lubricants

    Science.gov (United States)

    Carter, B. H.; Green, D.

    Marine diesel engines are classified by speed, either large (medium speed) or very large (slow speed) with high efficiencies and burning low-quality fuel. Slow-speed engines, up to 200 rpm, are two-stroke with separate combustion chamber and sump connected by a crosshead, with trunk and system oil lubricants for each. Medium-speed diesels, 300-1500 rpm, are of conventional automotive design with one lubricant. Slow-speed engines use heavy fuel oil of much lower quality than conventional diesel with problems of deposit cleanliness, acidity production and oxidation. Lubricants are mainly SAE 30/40/50 monogrades using paraffinic basestocks. The main types of additives are detergents/dispersants, antioxidants, corrosion inhibitors, anti-wear/load-carrying/ep, pour-point depressants and anti-foam compounds. There are no simple systems for classifying marine lubricants, as for automotive, because of the wide range of engine design, ratings and service applications they serve. There are no standard tests; lubricant suppliers use their own tests or the Bolnes 3DNL, with final proof from field tests. Frequent lubricant analyses safeguard engines and require standard sampling procedures before determination of density, viscosity, flash point, insolubles, base number, water and wear metal content.

  19. Intra-field variability in microbial community associated with phase-separation-controlled hydrothermal fluid chemistry in the Mariner field, the southern Lau Basin

    Science.gov (United States)

    Takai, K.; Ishibashi, J.; Lupton, J.; Ueno, Y.; Nunoura, T.; Hirayama, H.; Horikoshi, K.; Suzuki, R.; Hamasaki, H.; Suzuki, Y.

    2006-12-01

    A newly discovered hydrothermal field called the Mariner field at the northernmost central Valu Fa Ridge (VFR) in the Lau Basin was explored and characterized by geochemical and microbiological surveys. The hydrothermal fluid (max. 365 u^C) emitting from the most vigorous vent site (Snow chimney) was boiling just beneath the seafloor at a water depth of 1908 m and two end-members of hydrothermal fluid were identified. Mineral and fluid chemistry of typical brine-rich (Snow chimney and Monk chimney) and vapor-rich (Crab Restaurant chimney) hydrothermal fluids and the host chimney structures were analyzed. Microbial community structures in three chimney structures were also investigated by culture-dependent and - independent analyses. The 16S rRNA gene clone analysis revealed that both bacterial and archaeal rRNA gene communities at the chimney surface zones were different among three chimneys. The bacterial and archaeal rRNA gene communities of the Snow chimney surface were very similar with those in the dead chimneys, suggesting concurrence of metal sulfide deposition at the inside and weathering at the surface potentially due to its large structure and size. Cultivation analysis demonstrated the significant variation in culturability of various microbial components, particularly of thermophilic H2- and/or S-oxidizing chemolithoautotrophs such as the genera Aquifex and Persephonella, among the chimney sites. The culturability of these chemolithoautotrophs might be associated with the input of gaseous energy and carbon sources like H2S, H2 and CH4 from the hydrothermal fluids, and might be affected by phase-separation- controlled fluid chemistry. In addition, inter-fields comparison of microbial community structures determined by cultivation analysis revealed novel characteristics of the microbial communities in the Mariner field of the Lau Basin among the global deep-sea hydrothermal systems.

  20. Dynamic Analysis of Magnetotactic Bacteria and Construction of Bacterial Microrobot%趋磁细菌动力学分析及细菌机器人的构建

    Institute of Scientific and Technical Information of China (English)

    陈昌友; 宋涛; 杨岑玉; 马秋峰; 吴龙飞

    2015-01-01

    利用具有磁场响应特性的趋磁细菌构建了一种趋磁细菌微机器人系统.首先建立了趋磁细菌MO-1的动力学模型,仿真分析了趋磁细菌在不同磁场条件下的运动特性,结果与实验结果吻合.然后,利用兔抗MO-1多克隆抗体与MO-1细胞反应,构建趋磁细菌MO-1机器人,其可借助抗体Fc段的亲和特性与金黄色葡萄球菌连接.通过搭建的磁场控制系统,在微流控芯片中实现了趋磁细菌机器人对金黄色葡萄球菌的捕获与分离.研究结果显示,构建的趋磁细菌机器人系统可以有效实现对特异细菌的分离,在医学检测分析方面将发挥重要的作用.%A magnetotactic bacterial microrobot system is fabricated using magnetotactic bacteria with magnetic respon-siveness. Firstly, a dynamic model of magnetotactic bacteria MO-1 is established and the dynamic features of MO-1 cells in different magnetic fields are analyzed through simulation. The simulation results agree with the experimental ones. Then MO-1 cells are coated by rabbit anti-MO-1 polyclonal antibodies to construct MO-1 bacterial microrobots. The microrobots can bind Staphylococcus aureus based on the affinity of Fc fragment of antibody. Staphylococcus aureus can be captured and separated in microfluidic chip by MO-1 microrobots through a fabricated magnetic controlling system. The experimental re-sults show that the magnetotactic bacterial microrobot system constructed here can achieve the separation of Staphylococcus aureus effectively, suggesting its important role in medical detection and analysis.

  1. Marine lakes of Indonesia

    NARCIS (Netherlands)

    Becking, Leontine Elisabeth

    2012-01-01

    The objective of this thesis was to obtain insight into the processes that play a role in biodiversity patterns of tropical marine species by using marine lakes as a model. Marine lakes are landlocked water bodies that maintain a marine character through narrow submarine connections to the sea. Two

  2. Thiogranum longum gen. nov., sp. nov., an obligately chemolithoautotrophic, sulfur-oxidizing bacterium of the family Ectothiorhodospiraceae isolated from a deep-sea hydrothermal field, and an emended description of the genus Thiohalomonas.

    Science.gov (United States)

    Mori, Koji; Suzuki, Ken-ichiro; Yamaguchi, Kaoru; Urabe, Tetsuro; Hanada, Satoshi

    2015-01-01

    A novel, obligately chemolithoautotrophic, sulfur-oxidizing bacterial strain, designated strain gps52(T), was isolated from a rock sample collected near the hydrothermal vents of the Suiyo Seamount in the Pacific Ocean. The cells possessed a Gram-stain-negative-type cell wall and contained menaquinone-8(H4) and menaquinone-9(H4) as respiratory quinones, and C16 : 1ω7c, C16 : 0 and C18 : 1ω7c as major cellular fatty acids. Neither storage compounds nor extensive internal membranes were observed in the cells. Strain gps52(T) grew using carbon dioxide fixation and oxidation of inorganic sulfur compounds with oxygen as electron acceptor. Optimal growth was observed at 32 °C, pH 6.5 and with 3 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain gps52(T) belongs to the family Ectothiorhodospiraceae and is different from any other known bacteria, with sequence similarities of less than 93 %. Based on phenotypic and phylogenetic findings, the isolate is considered to represent a novel genus and species in the family Ectothiorhodospiraceae, and the name Thiogranum longum gen. nov., sp. nov. is proposed. The type strain is gps52(T) ( = NBRC 101260(T) = DSM 19610(T)). An emended description of the genus Thiohalomonas is also proposed.

  3. Sulfurovum aggregans sp. nov., a hydrogen-oxidizing, thiosulfate-reducing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent chimney, and an emended description of the genus Sulfurovum.

    Science.gov (United States)

    Mino, Sayaka; Kudo, Hideaki; Arai, Takayuki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi

    2014-09-01

    A novel mesophilic, strictly hydrogen-oxidizing, sulfur-, nitrate- and thiosulfate-reducing bacterium, designated strain Monchim33(T), was isolated from a deep-sea hydrothermal vent chimney at the Central Indian Ridge. The non-motile, rod-shaped cells were Gram-stain-negative and non-sporulating. Growth was observed between 15 and 37 °C (optimum 33 °C; 3.2 h doubling time) and between pH 5.4 and 8.6 (optimum pH 6.0). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. The G+C content of the genomic DNA was 42.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurovum and was closely related to Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum 42BK(T) (95.6 and 95.4 % similarity, respectively). DNA-DNA hybridization demonstrated that the novel isolate could be differentiated genotypically from Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum. On the basis of the molecular and physiological traits of the new isolate, the name Sulfurovum aggregans sp. nov. is proposed, with the type strain Monchim33(T) ( = JCM 19824(T) = DSM 27205(T)).

  4. Marine lakes of Indonesia

    OpenAIRE

    Becking, Leontine Elisabeth

    2012-01-01

    The objective of this thesis was to obtain insight into the processes that play a role in biodiversity patterns of tropical marine species by using marine lakes as a model. Marine lakes are landlocked water bodies that maintain a marine character through narrow submarine connections to the sea. Two regions in Indonesia were studied: Berau (East Kalimantan) and Raja Ampat (West Papua). The following questions were addressed: 1. What are the different types of marine lakes in Indonesia? 2. Are ...

  5. Magnetospirillum caucaseum sp. nov., Magnetospirillum marisnigri sp. nov. and Magnetospirillum moscoviense sp. nov., freshwater magnetotactic bacteria isolated from three distinct geographical locations in European Russia.

    Science.gov (United States)

    Dziuba, Marina; Koziaeva, Veronika; Grouzdev, Denis; Burganskaya, Ekaterina; Baslerov, Roman; Kolganova, Tatjana; Chernyadyev, Alexander; Osipov, Georgy; Andrianova, Ekaterina; Gorlenko, Vladimir; Kuznetsov, Boris

    2016-05-01

    Three strains of helical, magnetotactic bacteria, SO-1T, SP-1T and BB-1T, were isolated from freshwater sediments collected from three distinct locations in European Russia. Phylogenetic analysis showed that the strains belong to the genus Magnetospirillum. Strains SO-1T and SP-1T showed the highest 16S rRNA gene sequence similarity to Magnetospirillum magnetotacticum MS-1T (99.3 and 98.1 %, respectively), and strain BB-1T with Magnetospirillum gryphiswaldense MSR-1T (97.3 %). The tree based on concatenated deduced amino acid sequences of the MamA, B, K, M, O, P, Q and T proteins, which are involved in magnetosome formation, was congruent with the tree based on 16S rRNA gene sequences. The genomic DNA G+C contents of strains SO-1T, SP-1T and BB-1T were 65.9, 63.0 and 65.2 mol%, respectively. As major fatty acids, C18 : 1ω9, C16 : 1ω7c, C16 : 0 and C18 : 0 were detected. DNA-DNA hybridization values between the novel strains and their closest relatives in the genus Magnetospirillum were less than 51.7 ± 2.3 %. In contrast to M. magnetotacticum MS-1T, the strains could utilize butyrate and propionate; strains SO-1T and BB-1T could also utilize glycerol. Strain SP-1T showed strictly microaerophilic growth, whereas strains SO-1T and BB-1T were more tolerant of oxygen. The results of DNA-DNA hybridization and physiological tests allowed genotypic and phenotypic differentiation of the strains from each other as well as from the two species of Magnetospirillum with validly published names. Therefore, the strains represent novel species, for which we propose the names Magnetospirillum caucaseum sp. nov. (type strain SO-1T = DSM 28995T = VKM B-2936T), Magnetospirillum marisnigri sp. nov. (type strain SP-1T = DSM 29006T = VKM B-2938T) and Magnetospirillum moscoviense sp. nov. (type strain BB-1T = DSM 29455T = VKM B-2939T). PMID:26921147

  6. Supermarket Marine Biology.

    Science.gov (United States)

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  7. Marine Jurisdiction Boundaries

    Data.gov (United States)

    Department of Homeland Security — The NOAA Coastal Services Center's Marine Jurisdiction dataset was created to assist in marine spatial planning and offshore alternative energy sitting. This is a...

  8. Frontiers of marine science

    OpenAIRE

    Webb, T. J.; Poloczanska, E. S.

    2011-01-01

    On 9–13 October 2010 early career scientists from the UK and Australia across marine research fields were given the opportunity to come together in Perth, Australia to discuss the frontiers of marine research and exchange ideas.

  9. Mariner 10 Image Archive

    Data.gov (United States)

    National Aeronautics and Space Administration — The Mariner 10 Image Archive includes tools to view shaded relief maps of the surface of Mercury, a 3D globe, and all images acquired by NASA's Mariner 10 mission.

  10. Marine Mammal Protection Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Mammal Protection Act (MMPA or Act) prohibits, with certain exceptions, the "take" of marine mammals in U.S. waters and by U.S. citizens on the high...

  11. MarineCadastre.gov

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — MarineCadastre.gov is a marine information system that provides authoritative ocean data, offshore planning tools, and technical support to the offshore renewable...

  12. Tsunamis and marine life

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, D.V.S.; Ingole, B.S.; Tang, D.; Satyanarayan, B.; Zhao, H.

    The 26 December 2004 tsunami in the Indian Ocean exerted far reaching temporal and spatial impacts on marine biota. Our synthesis was based on satellite data acquired by the Laboratory for Tropical Marine Environmental Dynamics (LED) of the South...

  13. Carotenoids in Marine Animals

    OpenAIRE

    Takashi Maoka

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine a...

  14. Marine Education Knowledge Inventory.

    Science.gov (United States)

    Hounshell, Paul B.; Hampton, Carolyn

    This 35-item, multiple-choice Marine Education Knowledge Inventory was developed for use in upper elementary/middle schools to measure a student's knowledge of marine science. Content of test items is drawn from oceanography, ecology, earth science, navigation, and the biological sciences (focusing on marine animals). Steps in the construction of…

  15. Isolation of a Microaerobic Magnetotactic Bacterium TH-1 and Studies on the Magnetosome%一株微好氧趋磁细菌TH-1的分离及其磁小体研究

    Institute of Scientific and Technical Information of China (English)

    刘伟伟; 孙秀兰; 张银志; 王进; 樊惠良; 陈文君

    2012-01-01

    In order to study the properties of biomagnetism, a kind of magnetotactic bacteria TH-1 which is able to respond and orient along the lines of terrestrial or artificial magnmetic fields was isolated from Taihu lake. TH-1 is the first reported magnetotactic bacterium isolated from Taihu lake. Morphological observation was carried out using the transmission electron microscope and the results showed that magnetic cells each possess several magnetosomes that is circular-shaped and 10 nm-100 nm in diameter, which distributed in cytoplasm and the front cell wall. The Energy dispersive X-ray spectrum of magnetosome indicates that stain TH-1 consists of three mineral elements Fe,S and O. The magnetic properties both of the bacteria and magnetosomes were studied and a preliminary biochemical identification of the bacteria -was carried out . All the above results demonstrated that strain TH-1 is magnetotactic bacteria.%研究生物磁学的性质,从无锡太湖水域中分离到了一株沿着磁力线运动的微好氧细菌-趋磁细菌TH-1.尽管在其他淡水中曾经分离过到过趋磁细菌,但却从未在太湖中分离到过,因此TH-1是目前所见报道的第一株分离自太湖的趋磁细菌.采用透射电镜的方法对细菌进行了形态学观察,结果表明,每个细胞内含多个磁小体,呈圆形,直径范围在10~100 nm,分布在细胞质以及细胞壁前端.能谱结果显示,该菌磁小体的元素组成为铁(Fe)、硫(S)和氧(O).还对该菌以及磁小体的磁性进行了分析并且对菌株做了初步的生化鉴定.结果表明,分离得到的菌株隶属于趋磁细菌.

  16. Carotenoids in Marine Animals

    Directory of Open Access Journals (Sweden)

    Takashi Maoka

    2011-02-01

    Full Text Available Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade.

  17. Marine Robot Autonomy

    CERN Document Server

    2013-01-01

    Autonomy for Marine Robots provides a timely and insightful overview of intelligent autonomy in marine robots. A brief history of this emerging field is provided, along with a discussion of the challenges unique to the underwater environment and their impact on the level of intelligent autonomy required.  Topics covered at length examine advanced frameworks, path-planning, fault tolerance, machine learning, and cooperation as relevant to marine robots that need intelligent autonomy.  This book also: Discusses and offers solutions for the unique challenges presented by more complex missions and the dynamic underwater environment when operating autonomous marine robots Includes case studies that demonstrate intelligent autonomy in marine robots to perform underwater simultaneous localization and mapping  Autonomy for Marine Robots is an ideal book for researchers and engineers interested in the field of marine robots.      

  18. Marine Environmental History

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2012-01-01

    This essay provides an overview of recent trends in the historiography of marine environmental history, a sub-field of environmental history which has grown tremendously in scope and size over the last c. 15 years. The object of marine environmental history is the changing relationship between...... human society and natural marine resources. Within this broad topic, several trends and objectives are discernable. The essay argue that the so-called material marine environmental history has its main focus on trying to reconstruct the presence, development and environmental impact of past fisheries...... and whaling operations. This ambition often entails a reconstruction also of how marine life has changed over time. The time frame rages from Paleolithicum to the present era. The field of marine environmental history also includes a more culturally oriented environmental history, which mainly has come...

  19. Marine Indole Alkaloids

    Directory of Open Access Journals (Sweden)

    Natalie Netz

    2015-08-01

    Full Text Available Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed.

  20. Risks In Marine Insurance

    OpenAIRE

    Jelena Grdinic

    2008-01-01

    The author of this paper elaborates risks in marine insurance. Firstly, the author primarily specifies the concept, types and basic characteristics of risks, emphasizing specifics of marine risk in relation to general risks. The author particularly considers determination of risk according to our legal regulations and English Marine Insurance Act, as the most important act in this matter. Special attention is paid to insured risk according to the most recent standard conditions for insurance ...

  1. Marine Current Energy Conversion

    OpenAIRE

    Lundin, Staffan

    2016-01-01

    Marine currents, i.e. water currents in oceans and rivers, constitute a large renewable energy resource. This thesis presents research done on the subject of marine current energy conversion in a broad sense. A review of the tidal energy resource in Norway is presented, with the conclusion that tidal currents ought to be an interesting option for Norway in terms of renewable energy. The design of marine current energy conversion devices is studied. It is argued that turbine and generator cann...

  2. Marine electrical practice

    CERN Document Server

    Watson, G O

    1991-01-01

    Marine Engineering Series: Marine Electrical Practice, Sixth Edition focuses on changes in the marine industry, including the application of programmable electronic systems, generators, and motors. The publication first ponders on insulation and temperature ratings of equipment, protection and discrimination, and AC generators. Discussions focus on construction, shaft-drive generators, effect of unbalanced loading, subtransient and transient reactance, protection discrimination, fault current, measurement of ambient air temperature, and basis of machine ratings. The text then examines AC switc

  3. Coastal & Marine Issues Survey

    OpenAIRE

    Sidman, Charles; Fik, Tim; Havens, Karl

    2008-01-01

    Florida Sea Grant management and extension specialists developed a questionnaire to solicit information regarding the recipient’s county of residence, occupation, and primary coastal activities. Survey recipients were also asked to select from a list the top five marine-related topics that defined prior strategic plan themes (i.e., marine bio-technology, fisheries, aquaculture, seafood safety, coastal communities, ecosystem health, coastal hazards, and marine education). In add...

  4. Marine Ecological Regions 2000

    Data.gov (United States)

    California Department of Resources — This shapefile was screen digitized from 'Calecoregions1.jpg' a georectified digital image of the original map of California's ecoregions, including the marine...

  5. iMarine project

    OpenAIRE

    Castelli, Donatella; Ellebroek, Anton; Taconet, Narc; Pagano, Pasquale (ISTI-CNR)

    2012-01-01

    The state-of-art of the iMarine project is presented. The project aim is establishing and operating an e‐infrastructure contributing to the implementation of the principles of the Ecosystem Approach to Fisheries Management and Conservation of Marine Living Resources

  6. Cultivation of marine sponges

    Institute of Scientific and Technical Information of China (English)

    QU Yi; ZHANG Wei; LI Hua; YU Xingju; JIN Meifang

    2005-01-01

    Sponges are the most primitive of multicellular animals, and are major pharmaceutical sources of marine secondary metabolites. A wide variety of new compounds have been isolated from sponges. In order to produce sufficient amounts of the compounds of the needed, it is necessary to obtain large amount of sponges.The production of sponge biomass has become a focus of marine biotechnology.

  7. Marine functional food

    NARCIS (Netherlands)

    Luten, J.B.

    2009-01-01

    This book reviews the research on seafood and health, the use and quality aspects of marine lipids and seafood proteins as ingredients in functional foods and consumer acceptance of (marine) functional food. The first chapter covers novel merging areas where seafood may prevent disease and improve h

  8. High Performance Marine Vessels

    CERN Document Server

    Yun, Liang

    2012-01-01

    High Performance Marine Vessels (HPMVs) range from the Fast Ferries to the latest high speed Navy Craft, including competition power boats and hydroplanes, hydrofoils, hovercraft, catamarans and other multi-hull craft. High Performance Marine Vessels covers the main concepts of HPMVs and discusses historical background, design features, services that have been successful and not so successful, and some sample data of the range of HPMVs to date. Included is a comparison of all HPMVs craft and the differences between them and descriptions of performance (hydrodynamics and aerodynamics). Readers will find a comprehensive overview of the design, development and building of HPMVs. In summary, this book: Focuses on technology at the aero-marine interface Covers the full range of high performance marine vessel concepts Explains the historical development of various HPMVs Discusses ferries, racing and pleasure craft, as well as utility and military missions High Performance Marine Vessels is an ideal book for student...

  9. Marin Tsunami (video)

    Science.gov (United States)

    Filmed and edited by: Loeffler, Kurt; Gesell, Justine

    2010-01-01

    Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. The Marin coast could be struck by a tsunami. Whether you live in Marin County, visit the beaches, or rent or own a home near the coast, it is vital to understand the tsunami threat and take preparation seriously. Marin Tsunami tells the story of what several West Marin communities are doing to be prepared. This video was produced by the US Geological Survey (USGS) in cooperation with the Marin Office of Emergency Services.

  10. Marine fragrance chemistry.

    Science.gov (United States)

    Hügel, Helmut M; Drevermann, Britta; Lingham, Anthony R; Marriott, Philip J

    2008-06-01

    The main marine message in perfumery is projected by Calone 1951 (7-methyl-2H-1,5-benzodioxepin-3(4H)-one). Kraft (Givaudan) and Gaudin (Firmenich) further maximized the marine fragrance molecular membership by extending the carbon chain of the 7-Me group. Our research targeted the polar group of the benzodioxepinone parent compound to investigate how this region of molecular makeup resonates with the dominant marine fragrance of the Calone 1951 structure. The olfactory evaluation of analogues prepared by chemical modification or removal of the CO group resulted in the introduction of aldehydic, sweet and floral-fruity notes with a diluted/diminished potency of the marine odor. To further analyze the olfactory properties of benzodioxepinones containing a diverse range of aromatic ring substituents, a novel synthesis route was developed. We found that a 7-alkyl group in Calone 1951 was essential for the maintenance of the significant marine odor characteristic, and our studies support the concept that the odorant structure occupying the hydrophobic binding pocket adjacent to the aromatic ring-binding site of the olfactory receptor is pivotal in the design and discovery of more potent and characteristic marine fragrances. How the structure of benzodioxepinones connects to marine sea-breeze fragrances is our continuing challenging research focus at the chemistry-biology interface. PMID:18618392

  11. Marine Pollution and Ecotoxicology

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    of ocean water in relation to air–sea flux variable. 4. Persistent organic pollutants In view of the ever-increasing load of persistent organic contaminants in the marine environment, it is of great significance to assess the state of pollution due... problem of marine pollution, it is indeed a prime need of the hour to assess the state of pollution of the marine environment. environmental data off Cundapoor and Kasargod along the coast of Karnataka that can be utilized for comprehensive interpretation...

  12. LA POLLUTION MARINE

    OpenAIRE

    Goeury, David; Goeury, D

    2014-01-01

    National audience La pollution marine est définie comme l'introduction directe ou indirecte de déchets, de substances, ou d'énergie, y compris de sources sonores sous-marines d'origine humaine, qui entraîne ou qui est susceptible d'entraîner des effets nuisibles pour les ressources vivantes et les écosystèmes marins, avec pour conséquence, un appauvrissement de la biodiversité, des risques pour la santé humaine, des obstacles pour les activités maritimes, et notamment la pêche, le tourisme...

  13. 77 FR 2512 - Marine Mammals

    Science.gov (United States)

    2012-01-18

    ... National Oceanic and Atmospheric Administration RIN 0648-XA905 Marine Mammals AGENCY: National Marine...; receipt of application. SUMMARY: Notice is hereby given that Dorian Houser, Ph.D., National Marine Mammal... under the authority of the Marine Mammal Protection Act of 1972, as amended (MMPA; 16 U.S.C. 1361 et...

  14. 75 FR 68605 - Marine Mammals

    Science.gov (United States)

    2010-11-08

    ... Register (75 FR 39915) that a request for a permit to conduct research on gray whales (Eschrictius robustus... National Oceanic and Atmospheric Administration RIN 0648-XX23 Marine Mammals AGENCY: National Marine... Marine Science Center, Newport, OR has been issued a permit to conduct research on marine...

  15. 77 FR 9627 - Marine Mammals

    Science.gov (United States)

    2012-02-17

    ... National Oceanic and Atmospheric Administration RIN 0648-XB005 Marine Mammals AGENCY: National Marine.../2\\ W. 4th Avenue, Olympia, WA 98501, has applied in due form for a permit to take marine mammals in... subject permit is requested under the authority of the Marine Mammal Protection Act of 1972, as...

  16. Marine turtle capture data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — To estimate abundance, growth, and survival rate and to collect tissue samples, marine turtles are captured at nesting beaches and foraging grounds through various...

  17. Marine Pollution Prevention Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Pollution Prevention Act of 2008 implements the International Convention for the Prevention of Pollution from Ships, including related Protocols (MARPOL)...

  18. Marine Natural Products Revisited.

    Science.gov (United States)

    Chang, Clifford W. J.

    1978-01-01

    Reports the chemistry of saxitoxin, a paralytic shellfish poison, and other toxins, including the structure of aplysiatoxins. Discusses the chemical signals and defense agents used in intra- and inter- species communication; anticancer agents; and organometallics in the marine environment. (MA)

  19. Marine prostanoids - a review

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; DeSouza, L.

    The occurrence and structure of prostaglandins including clavulones, punaglandins and claviridenones in marine organisms is reviewEd. by comparison of the spectral data reported the identity of 20-acetoxy claviridenones b and c with 20 acetoxy...

  20. WMO Marine Final Reports

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Final reports of the World Meteorological Organization (WMO) Commission for Marine Meteorology, Commission for Synoptic Meteorology, and Commission for Basic...

  1. Mariner Outreach Data

    Data.gov (United States)

    Department of Transportation — This dataset provides MARAD with the ability to determine available personnel and resources in a time of emergency. It also provides a portal for mariners to update...

  2. Marine meteorology and fisheries

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.

    importance migrate in response to changes in sea temperature storms of shorter duration also influence the distribution of fish in shallow coastal waters as they set up turbulent conditions to which some species are unable to withstand. Therefore marine...

  3. The marine cyanobacterium

    NARCIS (Netherlands)

    Pade, N.; Compaoré, J.; Klähn, S.; Stal, L.J.; Hagemann, M.

    2012-01-01

    Compatible solutes are small organic molecules that are involved in the acclimation to various stresses such as temperature and salinity. Marine or moderate halotolerant cyanobacteria accumulate glucosylglycerol, while cyanobacteria with low salt tolerance (freshwater strains) usually accumulate suc

  4. LEGACY - EOP Marine Debris

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contains towed diver surveys of and weights of marine debris removed from the near shore environments of the NWHI.

  5. Exopolysaccharides from Marine Bacteria

    Institute of Scientific and Technical Information of China (English)

    CHI Zhenming; FANG Yan

    2005-01-01

    Microbial polysaccharides represent a class of important products of growing interest for many sectors of industry. In recent years, there has been a growing interest in isolating new exopolysaccharides (EPSs)-producing bacteria from marine environments, particularly from various extreme marine environments. Many new marine microbial EPSs with novel chemical compositions, properties and structures have been found to have potential applications in fields such as adhesives,textiles, pharmaceuticals and medicine for anti-cancer, food additives, oil recovery and metal removal in mining and industrial waste treatments, etc This paper gives a brief summary of the information about the EPSs produced by marine bacteria,including their chemical compositions, properties and structures, together with their potential applications in industry.

  6. Marine Reference Materials

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various publications and other instructions for taking marine weather observations. includes Weather Service Observing Handbook No. 1, Weather Bureau Circular M,...

  7. Marine & hydrokinetic technology development.

    Energy Technology Data Exchange (ETDEWEB)

    LiVecchi, Al (National Renewable Energy Laboratory); Jepsen, Richard Alan

    2010-06-01

    The Wind and Water Power Program supports the development of marine and hydrokinetic devices, which capture energy from waves, tides, ocean currents, the natural flow of water in rivers, and marine thermal gradients, without building new dams or diversions. The program works closely with industry and the Department of Energy's national laboratories to advance the development and testing of marine and hydrokinetic devices. In 2008, the program funded projects to develop and test point absorber, oscillating wave column, and tidal turbine technologies. The program also funds component design, such as techniques for manufacturing and installing coldwater pipes critical for ocean thermal energy conversion (OTEC) systems. Rigorous device testing is necessary to validate and optimize prototypes before beginning full-scale demonstration and deployment. The program supports device testing by providing technology developers with information on testing facilities. Technology developers require access to facilities capable of simulating open-water conditions in order to refine and validate device operability. The program has identified more than 20 tank testing operators in the United States with capabilities suited to the marine and hydrokinetic technology industry. This information is available to the public in the program's Hydrodynamic Testing Facilities Database. The program also supports the development of open-water, grid-connected testing facilities, as well as resource assessments that will improve simulations done in dry-dock and closed-water testing facilities. The program has established two university-led National Marine Renewable Energy Centers to be used for device testing. These centers are located on coasts and will have open-water testing berths, allowing researchers to investigate marine and estuary conditions. Optimal array design, development, modeling and testing are needed to maximize efficiency and electricity generation at marine and

  8. Magnetic properties of pelagic marine carbonates

    Science.gov (United States)

    Roberts, Andrew P.; Florindo, Fabio; Chang, Liao; Heslop, David; Jovane, Luigi; Larrasoaña, Juan C.

    2013-12-01

    Pelagic carbonates are deposited far from continents, usually at water depths of 3000-6000 m, at rates below 10 cm/kyr, and are a globally important sediment type. Recent advances, with recognition of widespread preservation of biogenic magnetite (the inorganic remains of magnetotactic bacteria), have fundamentally changed our understanding of the magnetic properties of pelagic carbonates. We review evidence for the magnetic minerals typically preserved in pelagic carbonates, the effects of magnetic mineral diagenesis on paleomagnetic and environmental magnetic records of pelagic carbonates, and what magnetic properties can tell us about the open-ocean environments in which pelagic carbonates are deposited. We also discuss briefly late diagenetic remagnetisations recorded by some carbonates. Despite recent advances in our knowledge of these phenomena, much remains undiscovered. We are only at early stages of understanding how biogenic magnetite gives rise to paleomagnetic signals in sediments and whether it carries a poorly understood biogeochemical remanent magnetisation. Recently developed techniques have potential for testing how different magnetotactic bacterial species, which produce different magnetite morphologies, respond to changing nutrient and oxygenation conditions. Future work needs to test whether it is possible to develop proxies for ancient nutrient conditions from well-calibrated modern magnetotactic bacterial occurrences. A tantalizing link between giant magnetofossils and Paleogene hyperthermal events needs to be tested; much remains to be learned about the relationship between climate and the organisms that biomineralised these large and novel magnetite morphologies. Rather than being a well-worn subject that has been studied for over 60 years, the magnetic properties of pelagic carbonates hold many secrets that await discovery.

  9. Marine Ecosystem Services

    DEFF Research Database (Denmark)

    Hasler, Berit; Ahtiainen, Heini; Hasselström, Linus;

    MARECOS (Marine Ecosystem Services) er et tværfagligt studie, der har haft til formål at tilvejebringe information vedrørende kortlægning og værdisætning af økosystemtjenester, som kan anvendes i forbindelse med udformning af regulering på det marine område såvel nationalt, som regionalt og...

  10. Marine Energy in Chile

    OpenAIRE

    Antonio Levy

    2012-01-01

    This is the first issue of a new series dedicated to deliver concise information on energy innovation published by the Energy Innovation Center at the IDB. This issue offers a primer on the potential for marine energy in Chile. The ocean is increasingly recognized as a viable source of renewable energy, and Chile, with its long coastline, powerful waves and tidal currents, has captured the attention of marine energy proponents. While harvesting this source of energy would increase sustainabil...

  11. Marine Anthropogenic Litter

    OpenAIRE

    Bergmann, Melanie; Gutow, Lars; Klages, Michael

    2015-01-01

    This book describes how manmade litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers co...

  12. A Marine Traffic Flow Model

    OpenAIRE

    Tsz Leung Yip

    2013-01-01

    A model is developed for studying marine traffic flow through classical traffic flow theories, which can provide us with a better understanding of the phenomenon of traffic flow of ships. On one hand, marine traffic has its special features and is fundamentally different from highway, air and pedestrian traffic. The existing traffic models cannot be simply extended to marine traffic without addressing marine traffic features. On the other hand, existing literature on marine traffic focuses on...

  13. Variability in the microbial communities and hydrothermal fluid chemistry at the newly discovered Mariner hydrothermal field, southern Lau Basin

    Science.gov (United States)

    Takai, Ken; Nunoura, Takuro; Ishibashi, Jun-Ichiro; Lupton, John; Suzuki, Ryohei; Hamasaki, Hiroshi; Ueno, Yuichiro; Kawagucci, Shinsuke; Gamo, Toshitaka; Suzuki, Yohey; Hirayama, Hisako; Horikoshi, Koki

    2008-06-01

    A newly discovered hydrothermal field called the Mariner field on the Valu Fa Ridge in the southern Lau Basin was explored and characterized with geochemical and microbiological analyses. The hydrothermal fluid discharging from the most vigorous vent (Snow Chimney, maximum discharge temperature 365°C) was boiling at the seafloor at a depth of 1908 m, and two distinct end-member hydrothermal fluids were identified. The fluid chemistry of the typical Cl-enriched and Cl-depleted hydrothermal fluids was analyzed, as was the mineralogy of the host chimney structures. The variability in the fluid chemistry was potentially controlled by the subseafloor phase-separation (vapor loss process) and the microbial community activities. Microbial community structures in three chimney structures were investigated using culture-dependent and -independent techniques. The small subunit (SSU) rRNA gene clone analysis revealed that both bacterial and archaeal rRNA gene communities on the chimney surfaces differed among three chimneys. Cultivation analysis demonstrated significant variation in the culturability of various microbial components among the chimneys, particularly of thermophilic H2-oxidizing (and S-oxidizing) chemolithoautotrophs such as the genera Aquifex and Persephonella. The physical and chemical environments of chimney surface habitats are still unresolved and do not directly extrapolate the environments of possible subseafloor habitats. However, the variability in microbial community found in the chimneys also provides an insight into the different biogeochemical interactions potentially affected by the phase separation of the hydrothermal fluids in the subseafloor hydrothermal habitats. In addition, comparison with other deep-sea hydrothermal systems revealed that the Mariner field microbial communities have unusual characteristics.

  14. Metagenomic analysis of microbial consortium from natural crude oil that seeps into the marine ecosystem offshore Southern California

    Energy Technology Data Exchange (ETDEWEB)

    Hawley, Erik R.; Piao, Hailan; Scott, Nicole M.; Malfatti, Stephanie; Pagani, Ioanna; Huntemann, Marcel; Chen, Amy; del Rio, Tijana G.; Foster, Brian; Copeland, A.; Jansson, Janet K.; Pati, Amrita; Gilbert, Jack A.; Tringe, Susannah G.; Lorenson, Thomas D.; Hess, Matthias

    2014-01-02

    Crude oils can be major contaminants of the marine ecosystem and microorganisms play a significant role in the degradation of the main constituents of crude oil. To increase our understanding of the microbial hydrocarbon degradation process in the marine ecosystem, we collected crude oil from an active seep area located in the Santa Barbara Channel (SBC) and generated a total of about 52 Gb of raw metagenomic sequence data. The assembled data comprised ~500 Mb, representing ~1.1 million genes derived primarily from chemolithoautotrophic bacteria. Members of Oceanospirillales, a bacterial order belonging to the Deltaproteobacteria, recruited less than 2% of the assembled genes within the SBC metagenome. In contrast, the microbial community associated with the oil plume that developed in the aftermath of the Deepwater Horizon (DWH) blowout in 2010, was dominated by Oceanospirillales, which comprised more than 60% of the metagenomic data generated from the DWH oil plume. This suggests that Oceanospirillales might play a less significant role in the microbially mediated hydrocarbon conversion within the SBC seep oil compared to the DWH plume oil. We hypothesize that this difference results from the SBC oil seep being mostly anaerobic, while the DWH oil plume is aerobic. Within the Archaea, the phylum Euryarchaeota, recruited more than 95% of the assembled archaeal sequences from the SBC oil seep metagenome, with more than 50% of the sequences assigned to members of the orders Methanomicrobiales and Methanosarcinales. These orders contain organisms capable of anaerobic methanogenesis and methane oxidation (AOM) and we hypothesize that these orders and their metabolic capabilities may be fundamental to the ecology of the SBC oil seep.

  15. Bioprospecting marine plankton.

    Science.gov (United States)

    Abida, Heni; Ruchaud, Sandrine; Rios, Laurent; Humeau, Anne; Probert, Ian; De Vargas, Colomban; Bach, Stéphane; Bowler, Chris

    2013-11-01

    The ocean dominates the surface of our planet and plays a major role in regulating the biosphere. For example, the microscopic photosynthetic organisms living within provide 50% of the oxygen we breathe, and much of our food and mineral resources are extracted from the ocean. In a time of ecological crisis and major changes in our society, it is essential to turn our attention towards the sea to find additional solutions for a sustainable future. Remarkably, while we are overexploiting many marine resources, particularly the fisheries, the planktonic compartment composed of zooplankton, phytoplankton, bacteria and viruses, represents 95% of marine biomass and yet the extent of its diversity remains largely unknown and underexploited. Consequently, the potential of plankton as a bioresource for humanity is largely untapped. Due to their diverse evolutionary backgrounds, planktonic organisms offer immense opportunities: new resources for medicine, cosmetics and food, renewable energy, and long-term solutions to mitigate climate change. Research programs aiming to exploit culture collections of marine micro-organisms as well as to prospect the huge resources of marine planktonic biodiversity in the oceans are now underway, and several bioactive extracts and purified compounds have already been identified. This review will survey and assess the current state-of-the-art and will propose methodologies to better exploit the potential of marine plankton for drug discovery and for dermocosmetics. PMID:24240981

  16. Bioprospecting Marine Plankton

    Directory of Open Access Journals (Sweden)

    Chris Bowler

    2013-11-01

    Full Text Available The ocean dominates the surface of our planet and plays a major role in regulating the biosphere. For example, the microscopic photosynthetic organisms living within provide 50% of the oxygen we breathe, and much of our food and mineral resources are extracted from the ocean. In a time of ecological crisis and major changes in our society, it is essential to turn our attention towards the sea to find additional solutions for a sustainable future. Remarkably, while we are overexploiting many marine resources, particularly the fisheries, the planktonic compartment composed of zooplankton, phytoplankton, bacteria and viruses, represents 95% of marine biomass and yet the extent of its diversity remains largely unknown and underexploited. Consequently, the potential of plankton as a bioresource for humanity is largely untapped. Due to their diverse evolutionary backgrounds, planktonic organisms offer immense opportunities: new resources for medicine, cosmetics and food, renewable energy, and long-term solutions to mitigate climate change. Research programs aiming to exploit culture collections of marine micro-organisms as well as to prospect the huge resources of marine planktonic biodiversity in the oceans are now underway, and several bioactive extracts and purified compounds have already been identified. This review will survey and assess the current state-of-the-art and will propose methodologies to better exploit the potential of marine plankton for drug discovery and for dermocosmetics.

  17. Marine biodiversity in Colombia

    International Nuclear Information System (INIS)

    One decade ago, the seas and oceans were considered biologically less diverse that the terrestrial environment. Now it is known that it is on the contrary; 33 of the 34 categories of animals (phylum), they are represented in the sea, compared with those solely 15 that exist in earth. The investigation about the diversity of life in the sea has been relatively scorned, but there are big benefits that we can wait if this is protected. The captures of fish depend on it; the species captured by the fisheries are sustained of the biodiversity of their trophic chains and habitats. The marine species are probably the biggest reservoir of chemical substances that can be used in pharmaceutical products. The genetic material of some species can be useful in biotechnical applications. The paper treats topics like the current state of the knowledge in marine biodiversity and it is done a diagnostic of the marine biodiversity in Colombia

  18. Marine-Design Education

    DEFF Research Database (Denmark)

    Andersen, Poul; Birmingham, R.; Sortland, B.;

    2006-01-01

    This report addresses Marine-Design Education in view of present and forecasted demands of the maritime industry, determined by a drastically transforming economic and technological maritime environment. In this framework, this report discusses in depth IT-based Marine Design education (par. 4......) and reveals innovative educational concepts and initiatives, such as the EiT (Experts in a Team) concept (par. 3), the SFS (Student Friendly Software) initiative (par. 5), Education Driven Research (EDR, par. 6) and Research Based Education (RBE, par. 6). Nevertheless, the paper stresses the need...... for continuity between traditional and modern ways of teaching (par. 4) and points out that Marine Design education is not only about Design, but should also address project/business administration and decision making issues (par. 7)....

  19. Marine biosurfaces research program

    Science.gov (United States)

    The Office of Naval Research (ONR) of the U.S. Navy is starting a basic research program to address the initial events that control colonization of surfaces by organisms in marine environments. The program “arises from the Navy's need to understand and ultimately control biofouling and biocorrosion in marine environments,” according to a Navy announcement.The program, “Biological Processes Controlling Surface Modification in the Marine Environment,” will emphasize the application of in situ techniques and modern molecular biological, biochemical, and biophysical approaches; it will also encourage the development of interdisciplinary projects. Specific areas of interest include sensing and response to environmental surface (physiology/physical chemistry), factors controlling movement to and retention at surfaces (behavior/hydrodynamics), genetic regulation of attachment (molecular genetics), and mechanisms of attachment (biochemistry/surface chemistry).

  20. Marine nitrogen cycle

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.

    and particulate organic forms, respectively) and atmospheric deposition (~50 Tg N a -1 ), a substantial fraction of which is believed to be of anthropogenic (human-made) origin. Of the various loss terms of combined nitrogen from the ocean, emission of N 2 O... and nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci. Mar., 65, 85-105, 2001. Page 2 of 3Marine nitrogen cycle - Encyclopedia of Earth 11/20/2006http://www.eoearth.org/article/Marine_nitrogen_cycle square6 Gruber, N.: The dynamics...

  1. The Danish Marine Monitoring System

    DEFF Research Database (Denmark)

    Ærtebjerg, G.

    1997-01-01

    Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996.......Indeholder abstracts fra Workshop on Marine Monitoring Systems and Technology, Risø, 17-18 April 1996....

  2. Empowering marine science through genomics

    NARCIS (Netherlands)

    Volckaert, F.A M J; Barbier, M.; Canario, A; Olsen, J.L.; Wesnigk, J; Clark, M; Boyen, C

    2008-01-01

    Marine scientists in Europe summarize their successes with genome technologies in the marine sciences and make a plea for a concerted international effort to raise greater public education for support. (C) 2008 Elsevier B.V. All rights reserved.

  3. Marin miljøhistorie

    OpenAIRE

    Poulsen, Bo

    2012-01-01

    This essay provides an overview of recent trends in the historiography of marine environmental history, a sub-field of environmental history which has grown tremendously in scope and size over the last c. 15 years. The object of marine environmental history is the changing relationship between human society and natural marine resources. Within this broad topic, several trends and objectives are discernable. The essay argue that the so-called material marine environmental history has its main ...

  4. Neuroprotective Effects of Marine Algae

    OpenAIRE

    Se-Kwon Kim; Ratih Pangestuti

    2011-01-01

    The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae including antioxidant, anti-neuroinflammatory, choline...

  5. 76 FR 76949 - Marine Mammals

    Science.gov (United States)

    2011-12-09

    ... endangered and threatened species (50 CFR 222-226). Permit No. 14534, issued on July 2, 2010 (75 FR 39665... National Oceanic and Atmospheric Administration RIN 0648-XR52 Marine Mammals AGENCY: National Marine... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing...

  6. 75 FR 77616 - Marine Mammals

    Science.gov (United States)

    2010-12-13

    ... endangered and threatened species (50 CFR parts 222-226). Permit No. 14334, issued on August 17, 2009 (74 FR... National Oceanic and Atmospheric Administration RIN 0648-XP18 Marine Mammals AGENCY: National Marine... Marine Mammal Protection Act of 1972, as amended (16 U.S.C. 1361 et seq.), the regulations governing...

  7. 76 FR 72680 - Marine Mammals

    Science.gov (United States)

    2011-11-25

    ... December 9, 2010, notice was published in the Federal Register (75 FR 76703) that a request for a permit... National Oceanic and Atmospheric Administration RIN 0648-XA078 Marine Mammals AGENCY: National Marine.... Environmental Research and Services, Fairbanks, AK, to conduct research on marine mammals in Alaska....

  8. 77 FR 14352 - Marine Mammals

    Science.gov (United States)

    2012-03-09

    ... published in the Federal Register (76 FR 30919) that a request for a permit to conduct research on humpback... National Oceanic and Atmospheric Administration RIN 0648-XB065 Marine Mammals AGENCY: National Marine... permit has been issued under the authority of the Marine Mammal Protection Act of 1972, as amended (16...

  9. 76 FR 25308 - Marine Mammals

    Science.gov (United States)

    2011-05-04

    ... in the Federal Register (76 FR 4091) that Dr. Burns had requested a permit to collect/receive, import... National Oceanic and Atmospheric Administration RIN 0648-XA165 Marine Mammals AGENCY: National Marine... ] scientific research on marine mammal parts. ADDRESSES: The permit and related documents are available...

  10. Marine Science Sourcebook, First Edition.

    Science.gov (United States)

    Raimist, Roger J.

    This manual was prepared for a teacher workshop in marine science. It includes information on when, where, and how to collect marine mollusks, and how to prepare a shell collection; a partial key to the classes, subclasses, and orders of the mollusca; notes on the ecology and physiology of marine bivalves and snails, and recipes for solutions…

  11. Mafia marine resources in peril

    OpenAIRE

    Mndeme, Y.E.S.

    1995-01-01

    The rich marine resource of the Mafia District, Tanzania, especially its coral reefs and mangroves, are in danger of collapse. The proposed marine park faces chronic problems of dynamite fishing and coral mining. The Mafia fisheries resources and the importance of coral reefs are presented together with proposed measures to rescue the Mafia marine environment.

  12. Cultivation of marine sponges

    NARCIS (Netherlands)

    Osinga, R.; Tramper, J.; Wijffels, R.H.

    1999-01-01

    There is increasing interest in biotechnological production of marine sponge biomass owing to the discovery of many commercially important secondary metabolites in this group of animals. In this article, different approaches to producing sponge biomass are reviewed, and several factors that possibly

  13. Marine Mineral Exploration

    DEFF Research Database (Denmark)

    The past 20 years have seen extensive marine exploration work by the major industrialized countries. Studies have, in part, been concentrated on Pacific manganese nodule occurrences and on massive sulfides on mid-oceanic ridges. An international jurisdictional framework of the sea-bed mineral...

  14. Aspects of Marine Ecology.

    Science.gov (United States)

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations to impart ocean science understanding, specifically, aspects of marine ecology, to high school students. The course objectives include the ability of…

  15. Safety of Marine Structures

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    1990-01-01

    of a "future safe" design code for exposed marine structures like breakwaters should be different from the ones usually applied in modern design standards for conventional structures within civil engineering. Moreover, results from ongoing development of a design code for rubble mound breakwaters are presented....

  16. Marine Renewable Energies

    DEFF Research Database (Denmark)

    Azzellino, Arianna; Conley, Daniel; Vicinanza, Diego;

    2013-01-01

    Countries with coastlines may have valuable renewable energy resources in the form of tides, currents, waves, and offshorewind.The potential to gather energy from the sea has recently gained interest in several nations, so Marine Renewable Energy Installations (hereinafter MREIs) will likely beco...

  17. Thai marine fungal diversity

    Directory of Open Access Journals (Sweden)

    Rattaket Choeyklin

    2006-07-01

    Full Text Available The marine fungal diversity of Thailand was investigated and 116 Ascomycota, 3 Basidiomycota, 28 anamorphic fungi, 7 Stramenopiles recorded, with 30 tentatively identified. These species have primarily been collected from driftwood and attached decayed wood of mangrove trees. The holotype number of 15 taxa is from Thailand and 33 are new records from the country.

  18. Influence of marine engine simulator training to marine engineer's competence

    Science.gov (United States)

    Wang, Peng; Cheng, Xiangxin; Ma, Qiang; Song, Xiufu; Liu, Xinjian; Wang, Lianhai

    2012-01-01

    Marine engine simulator is broadly used in maritime education and training. Maritime education and training institutions usually use this facility to cultivate the hands-on ability and fault-treat ability of marine engineers and students. In this study, the structure and main function of DMS-2005 marine engine simulator is briefly introduced, several teaching methods are discussed. By using Delphi method and AHP method, a comprehensive evaluation system is built and the competence of marine engineers is assessed. After analyzing the calculating data, some conclusions can be drawn: comprehensive evaluation system could be used to assess marine engineer's competence; the training of marine engine simulator is propitious to enhance marine engineers' integrated ability, especially on the aspect of judgment of abnormal situation capacity, emergency treatment ability and safe operation ability.

  19. Marine Science, Back Ocean Exploring Marine Mysteries and Utilizing Marine Resources

    OpenAIRE

    Editorial Team

    2011-01-01

    Marine science, fusing biology, physics, chemistry, geology, and engineering together, has become a comprehensive and interdisciplinary sciences. Since the 1950's, many new technologies have bloomed along with the rapid development of marine science. In the twenty first century, human beings are facing severe challenges, such as food and energy shortages, climate warming, environmental degradation, and resource depletion, back to the ocean exploring marine mysteries and utilizing marine resou...

  20. Marine04 Marine radiocarbon age calibration, 26 ? 0 ka BP

    Energy Technology Data Exchange (ETDEWEB)

    Hughen, K; Baille, M; Bard, E; Beck, J; Bertrand, C; Blackwell, P; Buck, C; Burr, G; Cutler, K; Damon, P; Edwards, R; Fairbanks, R; Friedrich, M; Guilderson, T; Kromer, B; McCormac, F; Manning, S; Bronk-Ramsey, C; Reimer, P; Reimer, R; Remmele, S; Southon, J; Stuiver, M; Talamo, S; Taylor, F; der Plicht, J v; Weyhenmeyer, C

    2004-11-01

    New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration datasets extend an additional 2000 years, from 0-26 ka cal BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically dated tree-ring samples, converted with a box-diffusion model to marine mixed-layer ages, cover the period from 0-10.5 ka cal BP. Beyond 10.5 ka cal BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific {sup 14}C reservoir age information to provide a single global marine mixed-layer calibration from 10.5-26.0 ka cal BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the radiocarbon age to calculate the underlying calibration curve. The marine datasets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring datasets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al.

  1. Ubiquity and diversity of heterotrophic bacterial nasA genes in diverse marine environments.

    Directory of Open Access Journals (Sweden)

    Xuexia Jiang

    Full Text Available Nitrate uptake by heterotrophic bacteria plays an important role in marine N cycling. However, few studies have investigated the diversity of environmental nitrate assimilating bacteria (NAB. In this study, the diversity and biogeographical distribution of NAB in several global oceans and particularly in the western Pacific marginal seas were investigated using both cultivation and culture-independent molecular approaches. Phylogenetic analyses based on 16S rRNA and nasA (encoding the large subunit of the assimilatory nitrate reductase gene sequences indicated that the cultivable NAB in South China Sea belonged to the α-Proteobacteria, γ-Proteobacteria and CFB (Cytophaga-Flavobacteria-Bacteroides bacterial groups. In all the environmental samples of the present study, α-Proteobacteria, γ-Proteobacteria and Bacteroidetes were found to be the dominant nasA-harboring bacteria. Almost all of the α-Proteobacteria OTUs were classified into three Roseobacter-like groups (I to III. Clone library analysis revealed previously underestimated nasA diversity; e.g. the nasA gene sequences affiliated with β-Proteobacteria, ε-Proteobacteria and Lentisphaerae were observed in the field investigation for the first time, to the best of our knowledge. The geographical and vertical distributions of seawater nasA-harboring bacteria indicated that NAB were highly diverse and ubiquitously distributed in the studied marginal seas and world oceans. Niche adaptation and separation and/or limited dispersal might mediate the NAB composition and community structure in different water bodies. In the shallow-water Kueishantao hydrothermal vent environment, chemolithoautotrophic sulfur-oxidizing bacteria were the primary NAB, indicating a unique nitrate-assimilating community in this extreme environment. In the coastal water of the East China Sea, the relative abundance of Alteromonas and Roseobacter-like nasA gene sequences responded closely to algal blooms, indicating

  2. Marine pollution: an overview

    Science.gov (United States)

    Valentukevičienė, Marina; Brannvall, Evelina

    2008-01-01

    This overview of marine pollution follows the methodology as proposed below. Firstly, well-known databases (Science Direct, GeoRef, SpringerLINK, etc.) on technological research were studied. All collected references were divided into 27 sections following the key words associated with marine pollution, oil spills, alien species migration, etc. The most commercially promising research and development (R & D) activities seem to be market-oriented sections: detection of oil spills at sea, containment and recovery of floating oil at sea, detection of oil spills on land, disposal of oil and debris on land, alien species migration prevention from ballast water and underwater hull cleaning in water, NOx and SOx emissions, pollutions from ship-building and repair, and biogeochemical modelling. Great market demands for commercially patented innovations are very attractive for initiating new R & D projects.

  3. OCEANOGRAPHY & MARINE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20110729 Bai Youcheng(Laboratory of Marine Ecosystem and Biogeochemistry,SOA,Second Institute of Oceanography,Hangzhou 310012,China);Chen Jianfang Biomarker Records in Sediment Core of R12a from the Chukchi Sea during the Last 500 Years(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,28(4),2010,p.768-775,6 illus.,40 refs.)Key words:biomarkers,marine sediments,paleoproductivity,Arctic region This paper used multi-biomarkers to study the R12a core’s top 40 cm samples’ phytoplankton and community sampled during the Second Chinese Arctic expedition from the Chukchi Sea in summer,2003,and to obtain the information of the phytoplankton production and community change since 500 a.The results indicate the total and individual primary productivity increased over the last 500 a.The phytoplankton community structure mostly shows the contributions of

  4. Marine Bacterial Genomics

    DEFF Research Database (Denmark)

    Machado, Henrique

    For decades, terrestrial microorganisms have been used as sources of countless enzymes and chemical compounds that have been produced by pharmaceutical and biotech companies and used by mankind. There is a need for new chemical compounds, including antibiotics,new enzymatic activities and new...... microorganisms to be used as cell factories for production. Therefore exploitation of new microbial niches and use of different strategies is an opportunity to boost discoveries. Even though scientists have started to explore several habitats other than the terrestrial ones, the marine environment stands out...... as a hitherto under-explored niche. This thesis work uses high-throughput sequencing technologies on a collection of marine bacteria established during the Galathea 3 expedition, with the purpose of unraveling new biodiversity and new bioactivities. Several tools were used for genomic analysis in order...

  5. Marine cage fish farming

    OpenAIRE

    Espeut, P.; Harache, Yves; Lemarie, Gilles; Ricard, Jean-marc

    1993-01-01

    Les pêcheries de captage marin en Jamaïque sont principalement de nature artisanale et elles sont dirigées principalement par les pêcheurs qui travaillent depuis des canoës. Environ 95 % de ces pêcheurs travaillent sur la plaine côtière et ses bancs associés. Les espèces commerciales récoltées comprennent les espèces benthiques, les espèces de corail et les espèces de poisson marin de nage libre. D'autres ressources de pêcheries de valeur commerciale comprennent la crevette, la conque et le h...

  6. New marine community

    Science.gov (United States)

    While exploring the West Florida Escarpment, a steep slope in the Gulf of Mexico several hundred kilometers off the Florida coast, the deep submergence research vessel Alvin chanced upon a well-developed community of marine life akin to that found 7 years ago in the eastern Pacific Ocean.According to the Woods Hole Oceanographic Institution, which operates the submersible and its new tender, the Atlantis II (Eos, November 1, 1983, p. 619), the marine community contains large clams, mussels, crabs, fish, and tube worms like those found at hydrothermal vents in the eastern Pacific. While the east Pacific communities exist at spreading centers, the newly discovered group, which may stretch for almost 2 km at a depth of roughly 3200 km, lies in a passive continental margin. Also, whereas the water around the Pacific hydrothermal vents is much warmer than the surrounding seawater, the water around the new found community is apparently the same temperature as the ambient waters.

  7. Marine Cloud Brightening

    Energy Technology Data Exchange (ETDEWEB)

    Latham, John; Bower, Keith; Choularton, Tom; Coe, H.; Connolly, P.; Cooper, Gary; Craft, Tim; Foster, Jack; Gadian, Alan; Galbraith, Lee; Iacovides, Hector; Johnston, David; Launder, Brian; Leslie, Brian; Meyer, John; Neukermans, Armand; Ormond, Bob; Parkes, Ben; Rasch, Philip J.; Rush, John; Salter, Stephen; Stevenson, Tom; Wang, Hailong; Wang, Qin; Wood, Robert

    2012-09-07

    The idea behind the marine cloud-brightening (MCB) geoengineering technique is that seeding marine stratocumulus clouds with copious quantities of roughly monodisperse sub-micrometre sea water particles might significantly enhance the cloud droplet number concentration, and thereby the cloud albedo and possibly longevity. This would produce a cooling, which general circulation model (GCM) computations suggest could - subject to satisfactory resolution of technical and scientific problems identified herein - have the capacity to balance global warming up to the carbon dioxide-doubling point. We describe herein an account of our recent research on a number of critical issues associated with MCB. This involves (i) GCM studies, which are our primary tools for evaluating globally the effectiveness of MCB, and assessing its climate impacts on rainfall amounts and distribution, and also polar sea-ice cover and thickness; (ii) high-resolution modelling of the effects of seeding on marine stratocumulus, which are required to understand the complex array of interacting processes involved in cloud brightening; (iii) microphysical modelling sensitivity studies, examining the influence of seeding amount, seedparticle salt-mass, air-mass characteristics, updraught speed and other parameters on cloud-albedo change; (iv) sea water spray-production techniques; (v) computational fluid dynamics studies of possible large-scale periodicities in Flettner rotors; and (vi) the planning of a three-stage limited-area field research experiment, with the primary objectives of technology testing and determining to what extent, if any, cloud albedo might be enhanced by seeding marine stratocumulus clouds on a spatial scale of around 100 km. We stress that there would be no justification for deployment of MCB unless it was clearly established that no significant adverse consequences would result. There would also need to be an international agreement firmly in favour of such action.

  8. Lipids in Marine Ecosystems

    OpenAIRE

    Christopher C Parrish

    2013-01-01

    Lipids provide the densest form of energy in marine ecosystems. They are also a solvent and absorption carrier for organic contaminants and thus can be drivers of pollutant bioaccumulation. Among the lipids, certain essential fatty acids and sterols are considered to be important determinants of ecosystem health and stability. Fatty acids and sterols are also susceptible to oxidative damage leading to cytotoxicity and a decrease in membrane fluidity. The physical characteristics of biological...

  9. Streptomyces avermitilis from marine

    Institute of Scientific and Technical Information of China (English)

    XIONG Li-xia; LI Jian-zhong; WANG Hui-li

    2005-01-01

    The insecticidal strain 173 was isolated from marine source and its activity was explored by the bioassay of brine shrimp and Helicoverpa armigera. Based on morphological, physiological and molecular properties, the insecticidal strain 173 was identified as Streptonycetes avermitilis, which is the best insecticidal microorganism found in the terrestrial environment. The taxonomy of the strain173, insecticidal spectrum and properties of the corresponding insecticidal antibiotics are reported.

  10. Marine Microbiology: Facets & Opportunities

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.

    doctrine: ?the role of infinitely small is infinitely great?, this branch of science was at its infancy. Though it rapidly expanded its repertoire in the nineteenth and twentieth centuries, its marine facet began to reveal in the late 1940s with Claude E... contamination and their adverse effects on commerce and trade. For example, presence of infectious agents in seafood results in rejection of bulk consignments leading to major economic losses to exporting countries in general, and to seafood processing...

  11. 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...

  12. OCEANOGRAPHY & MARINE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20141271Chang Fengming(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China);Li Tiegang Progress in the Paleoceanography of the Western Pacific Warm Pool:A Review(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(8),2013,p.847-858,3 illus.,108 refs.)Key words:paleooceanography,West Pacific

  13. Marine botany. Second edition

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, C.J. [Univ. of South Florida, Tampa, FL (United States)

    1998-12-01

    Marine plants are a diverse group that include unicellular algae, seaweeds, seagrasses, salt marshes, and mangrove forests. They carry out a variety of ecological functions and serve as the primary producers in coastal wetlands and oceanic waters. The theme that connects such a wide variety of plants is their ecology, which was also emphasized in the 1981 edition. The goal of this revision is to present taxonomic, physiological, chemical, and ecological aspects of marine plants, their adaptations, and how abiotic and biotic factors interact in their communities. The data are presented in a concise, comparative manner in order to identify similarities and differences between communities such as salt marsh and mangroves or subtidal seaweeds and seagrasses. To accomplish this, the text is organized into five chapters that introduce the marine habitats, consider abiotic and biotic factors, and anthropogenic influences on the communities followed by seven chapters that deal with microalgae, seaweeds, salt marshes, mangroves, seagrasses, and coral reefs. Two appendixes are included; one presents simple field techniques and the other is a summary of seaweed uses.

  14. Marine natural products sourced from marine-derived Penicillium fungi.

    Science.gov (United States)

    Ma, Hong-Guang; Liu, Qiang; Zhu, Guo-Liang; Liu, Hai-Shan; Zhu, Wei-Ming

    2016-01-01

    Marine micro-organisms have been proven to be a major source of marine natural products (MNPs) in recent years, in which filamentous fungi are a vital source of bioactive natural products for their large metagenomes and more complex genetic backgrounds. This review highlights the 390 new MNPs from marine-derived Penicillium fungi during 1991 to 2014. These new MNPs are categorized based on the environment sources of the fungal hosts and their bioactivities are summarized.

  15. The Evolution of Marine Reptiles

    OpenAIRE

    Motani, Ryosuke

    2009-01-01

    Reptiles have repeatedly invaded marine environments despite their physiological constraints as air breathers. Marine reptiles were especially successful in the Mesozoic as major predators in the sea. There were more than a dozen groups of marine reptiles in the Mesozoic, of which four had more than 30 genera, namely sauropterygians (including plesiosaurs), ichthyopterygians, mosasaurs, and sea turtles. Medium-sized groups, such as Thalattosauria and Thalattosuchia, had about ten genera, wher...

  16. Anticancer agents from marine sponges.

    Science.gov (United States)

    Ye, Jianjun; Zhou, Feng; Al-Kareef, Ammar M Q; Wang, Hong

    2015-01-01

    Marine sponges are currently one of the richest sources of anticancer active compounds found in the marine ecosystems. More than 5300 different known metabolites are from sponges and their associated microorganisms. To survive in the complicated marine environment, most of the sponge species have evolved chemical means to defend against predation. Such chemical adaptation produces many biologically active secondary metabolites including anticancer agents. This review highlights novel secondary metabolites in sponges which inhibited diverse cancer species in the recent 5 years. These natural products of marine sponges are categorized based on various chemical characteristics. PMID:25402340

  17. Guidance Value of Marine Functional Zoning System to Allocation of China’s Marine Resources

    Institute of Scientific and Technical Information of China (English)

    Yingzhi; CAO; Guanshun; HE

    2015-01-01

    The issue of marine resources is receiving closer and closer attention of national marine management authorities. For this issue,it is necessary to seek basis from legal institutions of marine functional zoning system. This paper analyzed basic connotation,development process and basic characteristics of marine functional zoning system,discussed internal relation between marine functional zoning system and marine resource allocation,and studied guidance value of marine functional zoning system to allocation of marine resources.

  18. Marine Science, Back Ocean Exploring Marine Mysteries and Utilizing Marine Resources

    Directory of Open Access Journals (Sweden)

    Editorial Team

    2011-11-01

    Full Text Available Marine science, fusing biology, physics, chemistry, geology, and engineering together, has become a comprehensive and interdisciplinary sciences. Since the 1950's, many new technologies have bloomed along with the rapid development of marine science. In the twenty first century, human beings are facing severe challenges, such as food and energy shortages, climate warming, environmental degradation, and resource depletion, back to the ocean exploring marine mysteries and utilizing marine resources is an option to solve human dilemma. This launched journal, International Journal of Marine Science, is an open access, peer reviewed journal published online by BioPublisher in British Columbia of Canada. The aim of this journal is to be a platform for the marine science community to share knowledge as well as to disseminate discoveries in this field to help human benefitting from the ocean.

  19. Biotechnology of marine fungi

    Digital Repository Service at National Institute of Oceanography (India)

    Damare, S.; Singh, P.; Raghukumar, S.

    of the antioxidant enzyme, superoxide dismutase was found to increase as a defensive mechanism against high concentration of CuSO 4 in Cryptococcus sp., isolated from deep-sea sediments of 13    the Japan Trench (Abe et al. 2001).  Marine fungi deserve... different. All 14    the three polysaccharides showed good antioxidant properties, especially scavenging abilities on superoxide radicals and hydroxyl radicals.   *5.1 Production of omega-3 polyunsaturated fatty acids: The omega-3 polyunsaturated fatty...

  20. RATES OF SULFATE REDUCTION AND THIOSULFATE CONSUMPTION IN A MARINE MICROBIAL MAT

    NARCIS (Netherlands)

    VISSCHER, PT; PRINS, RA; VANGEMERDEN, H

    1992-01-01

    The sulfur cycle in a microbial mat was studied by determining viable counts of sulfate-reducing bacteria, chemolithoautotrophic sulfur bacteria and anoxygenic phototrophic bacteria. All three functional groups of sulfur bacteria revealed a maximum population density in the uppermost 5 mm of the mat

  1. 75 FR 19670 - Marine Highway Projects

    Science.gov (United States)

    2010-04-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Maritime Administration Marine Highway Projects ACTION: Solicitation of applications for Marine highway projects. SUMMARY: The Department of Transportation is soliciting applications for Marine Highway...

  2. A global census of marine microbes

    Digital Repository Service at National Institute of Oceanography (India)

    Amaral-Zettler, L.; Artigas, L.F.; Baross, J.; LokaBharathi, P.A; Boetius, A; Chandramohan, D.; Herndl, G.; Kogure, K.; Neal, P.; Pedros-Alio, C.; Ramette, A; Schouten, S.; Stal, L.; Thessen, A; De Leeuw, J.; Sogin, M.

    In this chapter we provide a brief history of what is known about marine microbial diversity, summarize our achievements in performing a global census of marine microbes, and reflect on the questions and priorities for the future of the marine...

  3. A novel marine silk.

    Science.gov (United States)

    Kronenberger, Katrin; Dicko, Cedric; Vollrath, Fritz

    2012-01-01

    The discovery of a novel silk production system in a marine amphipod provides insights into the wider potential of natural silks. The tube-building corophioid amphipod Crassicorophium bonellii produces from its legs fibrous, adhesive underwater threads that combine barnacle cement biology with aspects of spider silk thread extrusion spinning. We characterised the filamentous silk as a mixture of mucopolysaccharides and protein deriving from glands representing two distinct types. The carbohydrate and protein silk secretion is dominated by complex β-sheet structures and a high content of charged amino acid residues. The filamentous secretion product exits the gland through a pore near the tip of the secretory leg after having moved through a duct, which subdivides into several small ductules all terminating in a spindle-shaped chamber. This chamber communicates with the exterior and may be considered the silk reservoir and processing/mixing space, in which the silk is mechanically and potentially chemically altered and becomes fibrous. We assert that further study of this probably independently evolved, marine arthropod silk processing and secretion system can provide not only important insights into the more complex arachnid and insect silks but also into crustacean adhesion cements.

  4. Study of marine magnetic field

    Digital Repository Service at National Institute of Oceanography (India)

    Bhattacharya, G.C.

    of presenting marine magnetic data. The Generic Mapping Tools (GMT) software package (Wessel, P. and Smith, W. H. F.,1995), which can be downloaded over the internet is a very useful software package for presentation of marine magnetic data. This software...

  5. 76 FR 72681 - Marine Mammals

    Science.gov (United States)

    2011-11-25

    ... (75 FR 27300), authorizes the permit holder to take ribbon seals (Phoca fasciata), spotted seals (P... National Oceanic and Atmospheric Administration RIN 0648-XU87 Marine Mammals AGENCY: National Marine... Mammal Laboratory, (Responsible Party: Dr. John Bengtson, Director), Seattle, WA, has applied for...

  6. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

    Jørgensen, Christian; Peck, Myron A.; Antognarelli, Fabio;

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology...

  7. Ancient DNA from marine mammals

    DEFF Research Database (Denmark)

    Foote, Andrew David; Hofreiter, Michael; Morin, Philip A

    2012-01-01

    Marine mammals have long generation times and broad, difficult to sample distributions, which makes inferring evolutionary and demographic changes using field studies of extant populations challenging. However, molecular analyses from sub-fossil or historical materials of marine mammals such as b...

  8. Drug discovery from marine microbes.

    Science.gov (United States)

    Gerwick, William H; Fenner, Amanda M

    2013-05-01

    The marine environment has been a source of more than 20,000 inspirational natural products discovered over the past 50 years. From these efforts, 9 approved drugs and 12 current clinical trial agents have been discovered, either as natural products or as molecules inspired from the natural product structure. To a significant degree, these have come from collections of marine invertebrates largely obtained from shallow-water tropical ecosystems. However, there is a growing recognition that marine invertebrates are oftentimes populated with enormous quantities of "associated" or symbiotic microorganisms and that microorganisms are the true metabolic sources of these most valuable of marine natural products. Also, because of the inherently multidisciplinary nature of this field, a high degree of innovation is characteristic of marine natural product drug discovery efforts.

  9. Marine Casualty and Pollution Data for Researchers

    Data.gov (United States)

    Department of Homeland Security — The Marine Casualty and Pollution Data files provide details about marine casualty and pollution incidents investigated by Coast Guard Offices throughout the United...

  10. On China's Marine Safety

    Institute of Scientific and Technical Information of China (English)

    Wang Xianglin

    2010-01-01

    @@ The rising incidence of Somalian and Malaccan piracy has sounded an alarm bell for countries around the world.In order to ensure the safety of global shipping lanes,at least in the short term,it is necessary for countries to unite to combat these pirates.However,dealing with pirate activities is not easy.All countries know that competition for maritime rights and interests between various international powers lay behind the piracy.As a major developing country,China should understand the Somalian and Malaccan piracy from a national security perspective,while at the same time combating piracy and safeguarding world peace.In order to protect China's legitimate maritime rights,we should enact a long-term strategy for marine safety.By so doing,national security,as well as the uninterrupted use of the international sea lanes can be guaranteed.

  11. Why marine phytoplankton calcify.

    Science.gov (United States)

    Monteiro, Fanny M; Bach, Lennart T; Brownlee, Colin; Bown, Paul; Rickaby, Rosalind E M; Poulton, Alex J; Tyrrell, Toby; Beaufort, Luc; Dutkiewicz, Stephanie; Gibbs, Samantha; Gutowska, Magdalena A; Lee, Renee; Riebesell, Ulf; Young, Jeremy; Ridgwell, Andy

    2016-07-01

    Calcifying marine phytoplankton-coccolithophores- are some of the most successful yet enigmatic organisms in the ocean and are at risk from global change. To better understand how they will be affected, we need to know "why" coccolithophores calcify. We review coccolithophorid evolutionary history and cell biology as well as insights from recent experiments to provide a critical assessment of the costs and benefits of calcification. We conclude that calcification has high energy demands and that coccolithophores might have calcified initially to reduce grazing pressure but that additional benefits such as protection from photodamage and viral/bacterial attack further explain their high diversity and broad spectrum ecology. The cost-benefit aspect of these traits is illustrated by novel ecosystem modeling, although conclusive observations remain limited. In the future ocean, the trade-off between changing ecological and physiological costs of calcification and their benefits will ultimately decide how this important group is affected by ocean acidification and global warming. PMID:27453937

  12. OCEANOGRAPHY & MARINE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    <正>20102130 A.M.Gorodnitskiy(Shirshov Institute of Oceanology,Moscow);A.M.Filin Southern Barents Sea Anomalous Magnetic Field and Its Correlation with Bottom Geological Structure(Earth Science Frontiers,ISSN1005-2321,CN11-3370/P,16(6),2009,p.240-247,12 illus.,10 refs.)Key words:magnetic anomaly,submarine fracture zones,Barents Sea The results of data processing of marine magnetic surveys in a southern part of Barents Sea,executed from 1986 to 2001 are considered.The geomagnetic investigation of Southern Barents Sea bottom points on its complicated many-stage geologic-tectonic structures in which two disjunctive structures prevail:Riphean-Vendian inherited rift structures with north-west s

  13. iMarine - iMarine Data Management Software

    OpenAIRE

    Coro, Gianpaolo; Lelii, Lucio; Manzi, Andrea; Drakopoulos, Nikolaos; Marioli, Valentina; Cirillo, Roberto; Simeoni, Fabio; Antoniadis, Alexandros; Brito, Fabrice; Caumont, Herve

    2014-01-01

    The iMarine Data Management Software comprises a number of components and subsystems offering facilities for accessing, transferring and harmonising a rich array of data typologies. This document describes the novelties within the iMarine Data Management Software from M12 (Oct.'12) to M27 (Jan.'14). It complements D9.2 [10] which describes iMarine Data Management Software up to M11 (Sept.'12). This deliverable is intended for documentation purposes only. The actual deliverable is represented ...

  14. iMarine - iMarine Data Management Software

    OpenAIRE

    Coro, Gianpaolo; De Faveri, Federico; Lelii, Lucio; Manzi, Andrea; Drakopoulos, Nikolaos; Marioli, Valentina; Simeoni, Fabio; Antoniadis, Alexandros

    2012-01-01

    The iMarine Data Management Software comprises a number of components and subsystems offering facilities for accessing, transferring and harmonising a rich array of data typologies. This document describes the novelties within the iMarine Data Management Software from M7 (May.'12) to M11 (Sept.'12). It complements D9.1 [10] which describes iMarine Data Management Software up to M6 (Apr.'12). This deliverable is intended for documentation purposes only. The actual deliverable is represented by...

  15. Microbial iron mats at the Mid-Atlantic Ridge and evidence that Zetaproteobacteria may be restricted to iron-oxidizing marine systems.

    Directory of Open Access Journals (Sweden)

    Jarrod J Scott

    Full Text Available Chemolithoautotrophic iron-oxidizing bacteria play an essential role in the global iron cycle. Thus far, the majority of marine iron-oxidizing bacteria have been identified as Zetaproteobacteria, a novel class within the phylum Proteobacteria. Marine iron-oxidizing microbial communities have been found associated with volcanically active seamounts, crustal spreading centers, and coastal waters. However, little is known about the presence and diversity of iron-oxidizing communities at hydrothermal systems along the slow crustal spreading center of the Mid-Atlantic Ridge. From October to November 2012, samples were collected from rust-colored mats at three well-known hydrothermal vent systems on the Mid-Atlantic Ridge (Rainbow, Trans-Atlantic Geotraverse, and Snake Pit using the ROV Jason II. The goal of these efforts was to determine if iron-oxidizing Zetaproteobacteria were present at sites proximal to black smoker vent fields. Small, diffuse flow venting areas with high iron(II concentrations and rust-colored microbial mats were observed at all three sites proximal to black smoker chimneys. A novel, syringe-based precision sampler was used to collect discrete microbial iron mat samples at the three sites. The presence of Zetaproteobacteria was confirmed using a combination of 16S rRNA pyrosequencing and single-cell sorting, while light micros-copy revealed a variety of iron-oxyhydroxide structures, indicating that active iron-oxidizing communities exist along the Mid-Atlantic Ridge. Sequencing analysis suggests that these iron mats contain cosmopolitan representatives of Zetaproteobacteria, but also exhibit diversity that may be uncommon at other iron-rich marine sites studied to date. A meta-analysis of publically available data encompassing a variety of aquatic habitats indicates that Zetaproteobacteria are rare if an iron source is not readily available. This work adds to the growing understanding of Zetaproteobacteria ecology and suggests

  16. Marine biodiversity in Japanese waters.

    Directory of Open Access Journals (Sweden)

    Katsunori Fujikura

    Full Text Available To understand marine biodiversity in Japanese waters, we have compiled information on the marine biota in Japanese waters, including the number of described species (species richness, the history of marine biology research in Japan, the state of knowledge, the number of endemic species, the number of identified but undescribed species, the number of known introduced species, and the number of taxonomic experts and identification guides, with consideration of the general ocean environmental background, such as the physical and geological settings. A total of 33,629 species have been reported to occur in Japanese waters. The state of knowledge was extremely variable, with taxa containing many inconspicuous, smaller species tending to be less well known. The total number of identified but undescribed species was at least 121,913. The total number of described species combined with the number of identified but undescribed species reached 155,542. This is the best estimate of the total number of species in Japanese waters and indicates that more than 70% of Japan's marine biodiversity remains un-described. The number of species reported as introduced into Japanese waters was 39. This is the first attempt to estimate species richness for all marine species in Japanese waters. Although its marine biota can be considered relatively well known, at least within the Asian-Pacific region, considering the vast number of different marine environments such as coral reefs, ocean trenches, ice-bound waters, methane seeps, and hydrothermal vents, much work remains to be done. We expect global change to have a tremendous impact on marine biodiversity and ecosystems. Japan is in a particularly suitable geographic situation and has a lot of facilities for conducting marine science research. Japan has an important responsibility to contribute to our understanding of life in the oceans.

  17. Databases of the marine metagenomics

    KAUST Repository

    Mineta, Katsuhiko

    2015-10-28

    The metagenomic data obtained from marine environments is significantly useful for understanding marine microbial communities. In comparison with the conventional amplicon-based approach of metagenomics, the recent shotgun sequencing-based approach has become a powerful tool that provides an efficient way of grasping a diversity of the entire microbial community at a sampling point in the sea. However, this approach accelerates accumulation of the metagenome data as well as increase of data complexity. Moreover, when metagenomic approach is used for monitoring a time change of marine environments at multiple locations of the seawater, accumulation of metagenomics data will become tremendous with an enormous speed. Because this kind of situation has started becoming of reality at many marine research institutions and stations all over the world, it looks obvious that the data management and analysis will be confronted by the so-called Big Data issues such as how the database can be constructed in an efficient way and how useful knowledge should be extracted from a vast amount of the data. In this review, we summarize the outline of all the major databases of marine metagenome that are currently publically available, noting that database exclusively on marine metagenome is none but the number of metagenome databases including marine metagenome data are six, unexpectedly still small. We also extend our explanation to the databases, as reference database we call, that will be useful for constructing a marine metagenome database as well as complementing important information with the database. Then, we would point out a number of challenges to be conquered in constructing the marine metagenome database.

  18. Databases of the marine metagenomics.

    Science.gov (United States)

    Mineta, Katsuhiko; Gojobori, Takashi

    2016-02-01

    The metagenomic data obtained from marine environments is significantly useful for understanding marine microbial communities. In comparison with the conventional amplicon-based approach of metagenomics, the recent shotgun sequencing-based approach has become a powerful tool that provides an efficient way of grasping a diversity of the entire microbial community at a sampling point in the sea. However, this approach accelerates accumulation of the metagenome data as well as increase of data complexity. Moreover, when metagenomic approach is used for monitoring a time change of marine environments at multiple locations of the seawater, accumulation of metagenomics data will become tremendous with an enormous speed. Because this kind of situation has started becoming of reality at many marine research institutions and stations all over the world, it looks obvious that the data management and analysis will be confronted by the so-called Big Data issues such as how the database can be constructed in an efficient way and how useful knowledge should be extracted from a vast amount of the data. In this review, we summarize the outline of all the major databases of marine metagenome that are currently publically available, noting that database exclusively on marine metagenome is none but the number of metagenome databases including marine metagenome data are six, unexpectedly still small. We also extend our explanation to the databases, as reference database we call, that will be useful for constructing a marine metagenome database as well as complementing important information with the database. Then, we would point out a number of challenges to be conquered in constructing the marine metagenome database.

  19. iMarine - iMarine Data Consumption Software

    OpenAIRE

    Antoniadis, Alex; Brito, Fabrice; Coro, Gianpaolo; Gerbesiotis, John; Laskaris, Nikolas; Marketakis, Yannis

    2014-01-01

    This document describes the novelties within the iMarine Data Consumption Software which were achieved from the 13th to the 27th month of the project and provide pointers to the documentation and artifacts of the related components.

  20. iMarine - iMarine Data management software

    OpenAIRE

    Coro, Gianpaolo; De Faveri, Federico; Lelii, Lucio

    2012-01-01

    This deliverable describes the novelties within the iMarine Data Management Software up to M6 (Apr. '12), which include: Data Access, Data Transfer, Assessment,Harmonization and Certification facilities.

  1. Climate change and marine life

    DEFF Research Database (Denmark)

    Richardson, Anthony J.; Brown, Christopher J.; Brander, Keith;

    2012-01-01

    A Marine Climate Impacts Workshop was held from 29 April to 3 May 2012 at the US National Center of Ecological Analysis and Synthesis in Santa Barbara. This workshop was the culmination of a series of six meetings over the past three years, which had brought together 25 experts in climate change...... ecology, analysis of large datasets, palaeontology, marine ecology and physical oceanography. Aims of these workshops were to produce a global synthesis of climate impacts on marine biota, to identify sensitive habitats and taxa, to inform the current Intergovernmental Panel on Climate Change (IPCC......) process, and to strengthen research into ecological impacts of climate change...

  2. Innovation Educational Programme “Marine Engineer”

    OpenAIRE

    Zainutdinova, Larisa; Korablin, Anatoly; Goryayev, Roman

    2008-01-01

    The urgency of the problem of realizing the principles of open education for training engineers of marine specialities is shown. The innovation educational programme “Marine engineer” has been offered by the Marine technologies, power engineering and transport institute of Astrakhan State technical university [ASTU]. The structure of the Innovation educational center “Marine engineer” has been developed.

  3. Disease in marine aquaculture

    Science.gov (United States)

    Sindermann, C. J.

    1984-03-01

    It has become almost a truism that success in intensive production of animals must be based in part on development of methods for disease diagnosis and control. Excellent progress has been made in methods of diagnosis for major pathogens of cultivated fish, crustacean and molluscan species. In many instances these have proved to be facultative pathogens, able to exert severe effects in populations of animals under other stresses (marginal physical or chemical conditions; overcrowding). The concept of stress management as a critical prophylactic measure is not new, but its significance is being demonstrated repeatedly. The particular relationship of water quality and facultative pathogens such as Vibrio, Pseudomonas and Aeromonas species has been especially apparent. Virus diseases of marine vertebrates and invertebrates — little known two decades ago — are now recognized to be of significance to aquaculture. Virus infections of oysters, clams, shrimps and crabs have been described, and mortalities have been attributed to them. Several virus diseases of fish have also been recognized as potential or actual problems in culture. In some instances, the pathogens seem to be latent in natural populations, and may be provoked into patency by stresses of artificial environments. One of the most promising approaches to disease prophylaxis is through immunization. Fish respond well to various vaccination procedures, and new non-stressing methods have been developed. Vibriosis — probably the most severe disease of ocean-reared salmon — has been controlled to a great extent through use of a polyvalent bacterin, which can be modified as new pathogenic strains are isolated. Prophylactic immunization for other bacterial diseases of cultivated fish has been attempted, especially in Japan, with some success. There is also some evidence that the larger crustaceans may be immunologically responsive, and that at least short-term protection may be afforded to cultured

  4. Australia's marine virtual laboratory

    Science.gov (United States)

    Proctor, Roger; Gillibrand, Philip; Oke, Peter; Rosebrock, Uwe

    2014-05-01

    In all modelling studies of realistic scenarios, a researcher has to go through a number of steps to set up a model in order to produce a model simulation of value. The steps are generally the same, independent of the modelling system chosen. These steps include determining the time and space scales and processes of the required simulation; obtaining data for the initial set up and for input during the simulation time; obtaining observation data for validation or data assimilation; implementing scripts to run the simulation(s); and running utilities or custom-built software to extract results. These steps are time consuming and resource hungry, and have to be done every time irrespective of the simulation - the more complex the processes, the more effort is required to set up the simulation. The Australian Marine Virtual Laboratory (MARVL) is a new development in modelling frameworks for researchers in Australia. MARVL uses the TRIKE framework, a java-based control system developed by CSIRO that allows a non-specialist user configure and run a model, to automate many of the modelling preparation steps needed to bring the researcher faster to the stage of simulation and analysis. The tool is seen as enhancing the efficiency of researchers and marine managers, and is being considered as an educational aid in teaching. In MARVL we are developing a web-based open source application which provides a number of model choices and provides search and recovery of relevant observations, allowing researchers to: a) efficiently configure a range of different community ocean and wave models for any region, for any historical time period, with model specifications of their choice, through a user-friendly web application, b) access data sets to force a model and nest a model into, c) discover and assemble ocean observations from the Australian Ocean Data Network (AODN, http://portal.aodn.org.au/webportal/) in a format that is suitable for model evaluation or data assimilation, and

  5. Marine archeology: The hidden history

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.

    Chandore, Gopakapattana, and Ela, which were the port capitals at different times of the long history. Four stone anchors from Goa waters indicate an active maritime activity during the pre-Portuguese period. An important aspect of marine archaeology...

  6. Seagrasses - The forgotton marine habitat

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.; Rodrigues, R.S.

    Seagrasses, a specialized group of flowering plants, submerged in the marine, estuarine, bay and backwater regions of the world. Though seagrass beds are of great ecological and socio economic importance, they are mostly unknown to Indians. Seagrass...

  7. Marine archaeological research in India

    Digital Repository Service at National Institute of Oceanography (India)

    Tripati, S.; Sundaresh; Vora, K.H.; Bandodkar, S.N.

    of this activity. All the developed countries have made tremendous progress in this field and substantial progress has been made in India in marine archaeology. Over the years the National Institute of Oceanography in collaboration with other Government agencies...

  8. NGDC Marine Trackline Geophysics Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains bathymetry, magnetic, gravity and seismic shot point navigation data collected during marine cruises from 1939 to the present. Coverage is...

  9. The elements of marine life

    Science.gov (United States)

    Planavsky, Noah J.

    2014-12-01

    Today, the ratio of carbon to nitrogen and phosphorus in marine organic matter is relatively constant. But this ratio probably varied during the Earth's history as a consequence of changes in the phytoplankton community and ocean oxygen levels.

  10. NCEI Marine Geology Data Archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine Geologic data compilations and reports in the NCEI archive are from academic and government sources around the world. Over ten terabytes of analyses,...

  11. Seaweed Aquaculture and Marine Biotechnology

    OpenAIRE

    Gonçalves Pereira, Rui

    2016-01-01

    Macroscopic marine algae, typically known as macroalgae or seaweeds, form an important living resource of the oceans, as primary producers. People have collected seaweeds for food, both for humans and animals for millennia. They also have been a source of nutrient rich fertilizers, as well as a source of gelling agents known as phycocolloids. More recently macroalgae are playing significant roles in medicine and biotechnology. Although Biotechnology and in particular marine biotechnology may ...

  12. Origin of marine planktonic cyanobacteria

    OpenAIRE

    Sanchez-Baracaldo, Patricia

    2015-01-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stoch...

  13. Kinase Inhibitors from Marine Sponges

    Directory of Open Access Journals (Sweden)

    Ana Zivanovic

    2011-10-01

    Full Text Available Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included.

  14. Marine Structures with Heavy Overtopping

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Frigaard, Peter

    2000-01-01

    An investigation of wave overtopping of marine structures is described. Focus is put on structures with realtively low crest levels and various slope layouts subjected to non-breaking waves. Influence of slope draught and angle is investigated.......An investigation of wave overtopping of marine structures is described. Focus is put on structures with realtively low crest levels and various slope layouts subjected to non-breaking waves. Influence of slope draught and angle is investigated....

  15. Cobalt and marine redox evolution

    Science.gov (United States)

    Swanner, Elizabeth D.; Planavsky, Noah J.; Lalonde, Stefan V.; Robbins, Leslie J.; Bekker, Andrey; Rouxel, Olivier J.; Saito, Mak A.; Kappler, Andreas; Mojzsis, Stephen J.; Konhauser, Kurt O.

    2014-03-01

    Cobalt (Co) is a bio-essential trace element and limiting nutrient in some regions of the modern oceans. It has been proposed that Co was more abundant in poorly ventilated Precambrian oceans based on the greater utilization of Co by anaerobic microbes relative to plants and animals. However, there are few empirical or theoretical constraints on the history of seawater Co concentrations. Herein, we present a survey of authigenic Co in marine sediments (iron formations, authigenic pyrite and bulk euxinic shales) with the goal of tracking changes in the marine Co reservoir throughout Earth's history. We further provide an overview of the modern marine Co cycle, which we use as a platform to evaluate how changes in the redox state of Earth's surface were likely to have affected marine Co concentrations. Based on sedimentary Co contents and our understanding of marine Co sources and sinks, we propose that from ca. 2.8 to 1.8 Ga the large volume of hydrothermal fluids circulating through abundant submarine ultramafic rocks along with a predominantly anoxic ocean with a low capacity for Co burial resulted in a large dissolved marine Co reservoir. We tentatively propose that there was a decrease in marine Co concentrations after ca. 1.8 Ga resulting from waning hydrothermal Co sources and the expansion of sulfide Co burial flux. Changes in the Co reservoir due to deep-water ventilation in the Neoproterozoic, if they occurred, are not resolvable with the current dataset. Rather, Co enrichments in Phanerozoic euxinic shales deposited during ocean anoxic events (OAE) indicate Co mobilization from expanded anoxic sediments and enhanced hydrothermal sources. A new record of marine Co concentrations provides a platform from which we can reevaluate the role that environmental Co concentrations played in shaping biological Co utilization throughout Earth's history.

  16. Why marine phytoplankton calcify

    Science.gov (United States)

    Monteiro, Fanny M.; Bach, Lennart T.; Brownlee, Colin; Bown, Paul; Rickaby, Rosalind E. M.; Poulton, Alex J.; Tyrrell, Toby; Beaufort, Luc; Dutkiewicz, Stephanie; Gibbs, Samantha; Gutowska, Magdalena A.; Lee, Renee; Riebesell, Ulf; Young, Jeremy; Ridgwell, Andy

    2016-01-01

    Calcifying marine phytoplankton—coccolithophores— are some of the most successful yet enigmatic organisms in the ocean and are at risk from global change. To better understand how they will be affected, we need to know “why” coccolithophores calcify. We review coccolithophorid evolutionary history and cell biology as well as insights from recent experiments to provide a critical assessment of the costs and benefits of calcification. We conclude that calcification has high energy demands and that coccolithophores might have calcified initially to reduce grazing pressure but that additional benefits such as protection from photodamage and viral/bacterial attack further explain their high diversity and broad spectrum ecology. The cost-benefit aspect of these traits is illustrated by novel ecosystem modeling, although conclusive observations remain limited. In the future ocean, the trade-off between changing ecological and physiological costs of calcification and their benefits will ultimately decide how this important group is affected by ocean acidification and global warming. PMID:27453937

  17. Marine stratocumulus structure

    Science.gov (United States)

    Cahalan, Robert F.; Snider, Jack B.

    1989-01-01

    Thirty-three Landsat TM scenes of California stratocumulus cloud fields were acquired as part of the FIRE Marine Stratocumulus Intensive Field Observations in July 1987. They exhibit a wide variety of stratocumulus structures. Analysis has so far focused upon the July 7 scene, in which aircraft from NASA, NCAR, and the British Meteorological Office repeatedly gathered data across a stratocumulus-fair weather cumulus transition. The aircraft soundings validate the cloud base temperature threshold determined by spatial coherence analysis of the TM thermal band. Brightness variations in the stratocumulus region exhibit a -5/3 power-law decrease of the wavenumber spectra for scales larger than the cloud thickness, about 200 m, changing to a -3 power at smaller scales. Observations by an upward-looking three-channel microwave radiometer on San Nicolas Island also show the -5/3 power-law in total integrated liquid water, suggesting that the largest-scale TM brightness variations are primarily due to variations in the liquid water. The Kolmogorov 5/3 power suggests that for some purposes liquid water in turbulent stratocumulus clouds may be treated as a passive scalar, simply reflecting variations in vertical velocity. This may be tested using the velocities measured by the aircraft.

  18. Faunistics (marine animals)

    DEFF Research Database (Denmark)

    2009-01-01

    These PowerPoint files are compiled from various sources: Internet, field guides, scientific monographs, textbooks, my own photos and drawings, etc. I have no copyright or permission to use most of the illustrations. The file is therefore only intended for internal use within the Marine Biology...... course. Please, do not put it on Internet or distribute it by any means.     The reason for me to create this file is to facilitate the learning of species. We do not have enough time for field and laboratory work to allow students to learn to know the most important species by that method. We hope...... that the students will use the files as a preparation before the practicals.     Each slide in the files contain text, references to two books (see below), illustration(s) of a species and the name of that species. You are recommended to run the file in the slide show mode (Slide Show menue: View Show; or press...

  19. Origin of marine planktonic cyanobacteria.

    Science.gov (United States)

    Sánchez-Baracaldo, Patricia

    2015-01-01

    Marine planktonic cyanobacteria contributed to the widespread oxygenation of the oceans towards the end of the Pre-Cambrian and their evolutionary origin represents a key transition in the geochemical evolution of the Earth surface. Little is known, however, about the evolutionary events that led to the appearance of marine planktonic cyanobacteria. I present here phylogenomic (135 proteins and two ribosomal RNAs), Bayesian relaxed molecular clock (18 proteins, SSU and LSU) and Bayesian stochastic character mapping analyses from 131 cyanobacteria genomes with the aim to unravel key evolutionary steps involved in the origin of marine planktonic cyanobacteria. While filamentous cell types evolved early on at around 2,600-2,300 Mya and likely dominated microbial mats in benthic environments for most of the Proterozoic (2,500-542 Mya), marine planktonic cyanobacteria evolved towards the end of the Proterozoic and early Phanerozoic. Crown groups of modern terrestrial and/or benthic coastal cyanobacteria appeared during the late Paleoproterozoic to early Mesoproterozoic. Decrease in cell diameter and loss of filamentous forms contributed to the evolution of unicellular planktonic lineages during the middle of the Mesoproterozoic (1,600-1,000 Mya) in freshwater environments. This study shows that marine planktonic cyanobacteria evolved from benthic marine and some diverged from freshwater ancestors during the Neoproterozoic (1,000-542 Mya).

  20. DETOXIFICATION BY MAGNETOTACTIC BACTERIA IN SEDIMENTS

    Science.gov (United States)

    The ability of certain bacteria to take up iron in the environment and biosynthesis magnetic materials such as magnetite (Fe3O4) and greigite (Fe3S4) has been recognized (Blakemore, 1982; Bazylinski and Frankel, 2000). Two different mechanisms, biologically induced mineralizat...

  1. Food enrichment with marine phospholipid emulsions

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline P.;

    . The main objective of this study was to explore the possibilities of using marine PL for food enrichment. In order to achieve the objective, the study was divided into 4 stages: i) evaluation of physico-chemical properties of marine PL emulsions, ii) evaluation of hydrolytic and oxidative stability...... of marine PL emulsions, iii) evaluation of non-enzymatic browning reactions in marine PL emulsions, iv) evaluation of sensory properties and oxidative stability of yoghurt enriched with marine PL. The obtained results showed that marine PL have good emulsifying properties and it was feasible to prepare...... marine PL emulsions with and without addition of fish oil. The oxidative stability of marine PL emulsions was significantly influenced by the chemical composition of marine PL used for emulsions preparation. For instance, emulsions with good oxidative stability could be obtained when using raw materials...

  2. Implementing Marine XML for Observed CTD Data in a Marine Data Exchange Platform

    Institute of Scientific and Technical Information of China (English)

    JIANG Yongguo; FENG Yuan; CHE Zhaodong; ZHU Tieyi

    2008-01-01

    In order to archive,quality control and disseminate a large variety of marine data in a marine data exchange platform,a marine XML has been developed to encapsulate marine data,which provides an efficient means to store,transfer and display marine data.This paper first presents the details of the main marine XML elements and then gives an example showing how to transform CTD-observed data into Marine XML format,which illustrates the XML encapsulation process of marine observed data.

  3. Marine oil spill response organizations

    International Nuclear Information System (INIS)

    The obligations under the law relative to the prevention of marine oil spills and the type of emergency plans needed to mitigate any adverse effects caused by a marine oil spill were discussed. The organizational structure, spill response resources and operational management capabilities of Canada's newly created Response Organizations (ROs) were described. The overall range of oil spill response services that the RO provides to the domestic oil handling, oil transportation and the international shipping industries were reviewed. Amendments to the Canada Shipping Act which require that certain ships and oil handling facilities take oil spill preparedness and response measures, including having an arrangement with an RO certified by the Canadian Coast Guard, were outlined. Canadians now benefit from five ROs established to provide coast-to-coast oil spill response coverage. These include the Western Canada Marine Response Corporation, the Canadian Marine Response Management Corporation, the Great Lakes Response Corporation, the Eastern Canada Response Corporation and the Atlantic Emergency Response Team Ltd. ROs have the expertise necessary to organize and manage marine oil spill response services. They can provide equipment, personnel and operational management for the containment, recovery and cleanup of oil spilled on water

  4. International laboratory of marine radioactivity

    International Nuclear Information System (INIS)

    The director's report presents the overall aims and objectives of the laboratory, and some of the significant findings to date. Among these is the different behaviour in oceans of Pu and Am. Thus, fallout Pu, in contrast to Am, tends to remain in the soluble form. The vertical downward transport of Am is much quicker than for Pu. Since 1980, uptake and depuration studies of sup(95m)Tc have been carried out on key marine species. Marine environmental behaviour of Tc is being evaluated carefully in view of its being a significant constituent of nuclear wastes. Growing demands are being made on the laboratory for providing intercalibration and instrument maintenance services, and for providing training for scientists from developing countries. The body of the report is divided into 5 sections dealing with marine biology, marine chemistry, marine geochemistry/sedimentation, environmental studies, and engineering services, respectively. Appendices list laboratory staff, publications by staff members, papers and reports presented at meetings or conferences, consultants to the laboratory from 1967-1980, fellowships, trainees and membership of committees, task forces and working groups

  5. Chitin Degradation In Marine Bacteria

    DEFF Research Database (Denmark)

    Paulsen, Sara; Machado, Henrique; Gram, Lone

    2015-01-01

    Introduction: Chitin is the most abundant polymer in the marine environment and the second most abundant in nature. Chitin does not accumulate on the ocean floor, because of microbial breakdown. Chitin degrading bacteria could have potential in the utilization of chitin as a renewable carbon...... and nitrogen source in the fermentation industry.Methods: Here, whole genome sequenced marine bacteria were screened for chitin degradation using phenotypic and in silico analyses.Results: The in silico analyses revealed the presence of three to nine chitinases in each strain, however the number of chitinases...... chitin regulatory system.Conclusions: This study has provided insight into the ecology of chitin degradation in marine bacteria. It also served as a basis for choosing a more efficient chitin degrading production strain e.g. for the use of chitin waste for large-scale fermentations....

  6. Climate change and marine vertebrates.

    Science.gov (United States)

    Sydeman, William J; Poloczanska, Elvira; Reed, Thomas E; Thompson, Sarah Ann

    2015-11-13

    Climate change impacts on vertebrates have consequences for marine ecosystem structures and services. We review marine fish, mammal, turtle, and seabird responses to climate change and discuss their potential for adaptation. Direct and indirect responses are demonstrated from every ocean. Because of variation in research foci, observed responses differ among taxonomic groups (redistributions for fish, phenology for seabirds). Mechanisms of change are (i) direct physiological responses and (ii) climate-mediated predator-prey interactions. Regional-scale variation in climate-demographic functions makes range-wide population dynamics challenging to predict. The nexus of metabolism relative to ecosystem productivity and food webs appears key to predicting future effects on marine vertebrates. Integration of climate, oceanographic, ecosystem, and population models that incorporate evolutionary processes is needed to prioritize the climate-related conservation needs for these species. PMID:26564847

  7. Colour vision in marine organisms.

    Science.gov (United States)

    Marshall, Justin; Carleton, Karen L; Cronin, Thomas

    2015-10-01

    Colour vision in the marine environment is on average simpler than in terrestrial environments with simple or no colour vision through monochromacy or dichromacy. Monochromacy is found in marine mammals and elasmobranchs, including whales and sharks, but not some rays. Conversely, there is also a greater diversity of colour vision in the ocean than on land, examples being the polyspectral stomatopods and the many colour vision solutions found among reef fish. Recent advances in sequencing reveal more opsin (visual pigment) types than functionally useful at any one time. This diversity arises through opsin duplication and conversion. Such mechanisms allow pick-and-mix adaptation that tunes colour vision on a variety of very short non-evolutionary timescales. At least some of the diversity in marine colour vision is best explained as unconventional colour vision or as neutral drift. PMID:25725325

  8. European Research in Marine Structures

    DEFF Research Database (Denmark)

    Soares, C.Guedes; Jensen, Jørgen Juncher; Incecik, A.;

    2012-01-01

    An overview is presented of the results obtained in Europe by a network with a large number of research groups in the field of Marine Structures during a period of 6 years. The European Union has funded a project aimed at improving the collaboration among European research groups specialized...... in marine structures, which has led, among other results to a number of benchmark studies organized in 6 main topical areas, namely, Methods and Tools for Loads and Load Effects, Methods and Tools for Strength Assessment, Experimental Analysis of Structures, Materials and Fabrication of Structures, Methods...

  9. Marine injuries. Prevention and treatment.

    Science.gov (United States)

    Frey, C

    1994-08-01

    Penetrating wounds, stings, and inoculation of venom are common marine injuries to unwary walkers during the summer season. In many circumstances, foreign bodies such as wood splinters or small shards of glass can be removed readily with fine-pointed forceps. Other times, objects may not be noticed until radiographic examination of the injured area. With deeply penetrated foreign bodies, attempts at removal must often be weighed against the likelihood of continued symptoms and damage should the object be left in the foot. This review presents methods of prevention and treatment for common sources of marine foot injuries. PMID:7997347

  10. Recent Advances on Lipid Biomarkers in Marine Sediments

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-lin

    2014-01-01

    This paper reviews the recent advances of marine biomarker. Biomarkers of marine microorganisms are also included. It is important to the origin of marine biological and the monitor and evaluation of marine environment.

  11. 77 FR 53224 - Coastal and Marine Ecological Classification Standard

    Science.gov (United States)

    2012-08-31

    ...: Ecosystem inventory and mapping Coastal and marine spatial planning ] Marine Protected Area selection... Geological Survey Coastal and Marine Ecological Classification Standard AGENCY: Department of the Interior, U.S. Geological Survey. ACTION: Notice of endorsement of coastal and marine ecological...

  12. Metabolites from marine fungus Aspergillus sp.

    Digital Repository Service at National Institute of Oceanography (India)

    Wahidullah, S.; Rajmanickam, R.; DeSouza, L.

    Chemical examination of a methanolic extract of the marine fungus, Aspergillus sp., isolated from marine grass environment, yielded a steroid, ergosterol peroxide (1), and a mixture of known glyceride esters (2,3) of unsaturated fatty acids...

  13. Marine conservation strategies for Maharashtra Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Dhargalkar, V.K.

    Marine biodiversity is threatened in India because of several developmental pressures. Marine biologists of India are identifying the coastal and offshore areas of India for conservation. Some of these areas have been declared as Biosphere Reserves...

  14. Lessons from Vietnam's first marine park

    OpenAIRE

    Cheung, C

    1994-01-01

    The recent establishment of a marine park in Vietnam offers lessons for future marine reserves in the country as well as for other countries considering their establishment. These lessons are contained in this brief article.

  15. Computerizing marine biota: a rational approach

    Digital Repository Service at National Institute of Oceanography (India)

    Chavan, V.S.; Chandramohan, D.; Parulekar, A.H.

    Data on marine biota while being extensive are also patchy and scattered; thus making retrieval and dissemination of information time consuming. This emphasise the need for computerizing information on marine biota with the objective to collate...

  16. Southeast US Historical Marine Mammal Stranding Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data on marine mammal strandings are collected by the Southeast Marine Mammal Stranding Network. Basic data on the location, species identification, animal...

  17. Marine environment news. Vol. 2, no. 1

    International Nuclear Information System (INIS)

    In this issue of the IAEA's Marine Environment Newsletter topics including radiotracers as new barometers of ocean-climate coupling, bio-indicatos species in detecting marine radioactvity and pollution as well as training activities are covered

  18. Marine Debris Research, Prevention, and Reduction Act

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Debris Research, Prevention, and Reduction Act legally establishes the National Oceanic and Atmospheric Administration's (NOAA) Marine Debris Program....

  19. Emulsifying activity of hydrocarbonoclastic marine yeasts

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.

    Marine yeast growth on four petroleum hydrocarbons induced the production of extracellular emulsifying agents (biosurfactants). Out of the 17 marine yeast isolates tested, 7 isolates, i.e., Candida parapsilosis, C. cantarelli, C. membranae...

  20. Whale Multi-Disciplinary Studies: A Marine Education Infusion Unit. Northern New England Marine Education Project.

    Science.gov (United States)

    Maine Univ., Orono. Coll. of Education.

    This multidisciplinary unit deals with whales, whaling lore and history, and the interaction of the whale with the complex marine ecosystem. It seeks to teach adaptation of marine organisms. It portrays the concept that man is part of the marine ecosystem and man's activities can deplete and degrade marine ecosystems, endangering the survival of…

  1. 78 FR 25703 - Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Fisheries Research

    Science.gov (United States)

    2013-05-02

    ... species and stocks, ecosystem process changes, and marine ecological research. The SWFSC is the research... National Oceanic and Atmospheric Administration RIN 0648-XC336 Taking and Importing Marine Mammals; Taking Marine Mammals Incidental to Fisheries Research AGENCY: National Marine Fisheries Service...

  2. Marine Yeasts and Their Applications in Mariculture

    Institute of Scientific and Technical Information of China (English)

    CHI Zhenming; LIU Zhiqiang; GAO Lingmei; GONG Fang; MA Chunling; WANG Xianghong; LI Haifeng

    2006-01-01

    The terrestrial yeasts have been receiving great attention in science and industry for over one hundred years because they can produce many kinds of bioactive substances. However, little is known about the bioactive substances of marine yeasts. In recent years, it has been found that marine yeasts have wide applications in mariculture and other fields.Therefore, marine yeasts, the bioactive substances from them and the applications of marine yeasts themselves and the bioactive substances they produced are reviewed in this paper.

  3. Les Biotechnologies Marines dans le Grand Ouest

    OpenAIRE

    Boyen, Catherine; Jaouen, Pascal; Blanchard, Gilbert; Compere, Chantal; Dufour, Alain; Durand, Patrick; Guerard, Fabienne; Hallouin, Florence; Jebbar, Mohamed; Le Blay, Gwenaelle; Le Deit, Hervé; Le Seyec, Jocelyne; Monks, Brian; Portal-sellin, Rachel; Probert, Ian

    2015-01-01

    Marine (= blue) biotechnology, i.e. the utilization of marine bio-resources as a target or source of biotechnological applications, is a field with massive potential for innovation and economic growth. In a context of rapid climate change and increasing pressure on natural resources, renewed interest in marine biotechnology has been promoted by application of recent methodological and technological advances, notably in bioprocessing and in the various –omics domains, to the study of marine bi...

  4. Biomarkers of marine pollution and bioremediation

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    species of marine organisms and their bio-magnification across the food chain leading to serious threat to human health. In recent years, levels of contaminants in the marine environment have increased to a large extent as a consequence of vari- ous... anthropogenic activities. Most of the coastal areas around the world are reported to be damaged due to pol- lution, significantly affecting marine resources. In view of the stringent situation caused by marine pollution there is an urgent need of the hour...

  5. The sulfur cycle in the marine atmosphere

    Science.gov (United States)

    Toon, Owen B.; Kasting, James F.; Turco, Richard P.; Liu, May S.

    1987-01-01

    The simulation of the sulfur cycle in the marine atmosphere using a one-dimensional photochemical model is described and evaluated. Theoretical uncertainties concerning the operation of the marine sulfur cycle are examined, and measurements of sulfur gases in the marine atmosphere necessary for developing the model are derived. Previous modeling studies are reviewed, and the data from these studies are compared to the model simulations. Recommendations for improving the simulation of the sulfur cycle in the marine atmosphere are discussed.

  6. Structure of the marine economy complex of Ukraine

    OpenAIRE

    Trunin, Kostiantyn S.

    2014-01-01

    An interest to develop the marine resources and the World Ocean’s water space has increased in recent years. Within the processes of international integration and geopolitics the development of marine activities is getting a great significance more and more. There are such concepts as marine region, marine industry, region’s marine economy complex, marine cluster.  The scientific problem of structuring and classification of marine economy complex and regional marine uses is insufficiently dev...

  7. NODC Standard Format Marine Mammals of Coastal Alaska Data (1975-1981): Marine Mammal Specimens (F025) (NODC Accession 0014150)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC maintains data in three NODC Standard Format Marine Mammal Data Sets: Marine Mammal Sighting and Census (F127); Marine Mammal Specimens (F025); Marine Mammal...

  8. Bioactive Terpenes from Marine-Derived Fungi

    Directory of Open Access Journals (Sweden)

    Ahmed M. Elissawy

    2015-04-01

    Full Text Available Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years’ reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities.

  9. 50 CFR 14.18 - Marine mammals.

    Science.gov (United States)

    2010-10-01

    ... with the Marine Mammal Protection Act of 1972 and implementing regulations (50 CFR parts 18 and 216... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Marine mammals. 14.18 Section 14.18....18 Marine mammals. Any person subject to the jurisdiction of the United States who has lawfully...

  10. Climate change and marine top predators

    DEFF Research Database (Denmark)

    Climate change affects all components of marine ecosystems. For endothermic top predators, i.e. seabirds and marine mammals, these impacts are often complex and mediated through trophic relationships. In this Research Topic, leading researchers attempt to identify patterns of change among seabirds...... and marine mammals, and the mechanisms through which climate change drives these changes....

  11. 49 CFR 172.322 - Marine pollutants.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Marine pollutants. 172.322 Section 172.322... SECURITY PLANS Marking § 172.322 Marine pollutants. (a) For vessel transportation of each non-bulk packaging that contains a marine pollutant— (1) If the proper shipping name for a material which is a...

  12. Marine Functional Foods and Functional Ingredients

    OpenAIRE

    Hurst, D.

    2006-01-01

    This briefing paper gives insights into the issues surrounding marine functional foods and highlights opportunities for researchers in the marine sciences and food sciences areas to engage in collaborative research. It will be used as the basis for further consultation with the research community and firms in the marine and food sectors and to assist in exploring and prioritising research themes.

  13. Corrosion Failures in Marine Environment

    Directory of Open Access Journals (Sweden)

    R. Krishnan

    1985-04-01

    Full Text Available This paper gives a brief description of typical marine environments and the most common form of corrosion of materials used in this environment. Some typical case histories of failures pertaining to pitting, bimetallic corrosion, dealloying, cavitation and stress corrosion cracking are illustrated as typical examples of corrosion failures.

  14. 75 FR 76399 - Marine Mammals

    Science.gov (United States)

    2010-12-08

    ... (75 FR 68757), notice of receipt of an application to amend Permit No. 781-1824 was published... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XZ66 Marine Mammals AGENCY: National...

  15. Marine Picoeukaryotes in Cold Water

    DEFF Research Database (Denmark)

    Sørensen, Nikolaj

    Picoeukaryotes form an important part of marine ecosystems, both as primary producers, bacterial grazers and parasites. The Arctic is experiencing accelerated global warming and picoeukaryotes may thus be considered to be at the forefront of climate change. This PhD thesis sets out to investigate...

  16. Black carbon in marine sediments

    NARCIS (Netherlands)

    Middelburg, J.J.; Nieuwenhuize, J.; Van Breugel, P.

    1999-01-01

    Concentrations of black carbon were determined for a number of marine sediments. A comparison of black carbon based on thermal oxidation and hot concentrated nitric acid pretreatments revealed that the latter significantly overestimates combustion derived carbon phases. Black carbon accounts for abo

  17. The marine renewable energies file

    International Nuclear Information System (INIS)

    A set of articles addresses several aspects and issues related to the development of renewable marine energies: the objectives defined by the French government and the European Union in terms of share of renewable energies in energy consumption, some existing projects, the definition and assessment of the different renewable marine energies (offshore wind energy, sea thermal energy, sea current energy, sea tide energy, sea wave energy, marine biomass, osmotic energy), the need for a national strategy according to two researchers belonging to IFREMER, the implementation of the first offshore test platform by the Ecole Centrale de Nantes, the role of the ADEME (financial support, marketing studies, legislation, definition of a national programme), the recommendation by the European Commission of a large scale offshore wind energy development, the activities of EDF and Total in the field of marine energy, the problems faced by the first French offshore wind generator project, the actions undertaken in La Reunion in the field of sea thermal energy, and the opportunities in the use of micro-algae for hydrogen, bio-fuel or biogas production

  18. Perspectives in Marine Citizen Science

    Directory of Open Access Journals (Sweden)

    Michael Bear

    2015-11-01

    Full Text Available Citizen science can be defined as the process by which any non-scientist collects data or uses the scientific method under the guidance or mentorship of a scientist. This article presents an overview of several marine citizen-science projects as practiced by three non-profit organizations.

  19. Marine fuels and hydrogen sulphide

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, N.; Antunez Martel, F.J.; Bonini, A.; Buhaug, O.; Chevallier, F.; Heyberger, B.; Hovius, H.; Jansen, L.; Pocek, V.; Ramos, A.P.; Sasloglou, S.; Seppaalaa, K.; Steernberg, K.; Terschek, R.; Vermeire, M.; Rose, K.D.

    2013-10-15

    The safe handling of petroleum cargoes and refined products that may contain hydrogen sulphide (H2S) is an important issue for the marine and inland fuel industries. Attention has refocused recently on H2S due to the revision of the ISO 8217:2012 specification for marine fuels which limited the maximum content of H2S in the liquid fuel to 2.00 mg H2S/kg fuel (2.00 ppmw). This report summarizes issues associated with the presence of H2S in residual marine fuels including: Sources of H2S in petroleum products; Exposure levels for H2S in the vapour phase and the effects of exposure; Relationship between the H2S concentration in liquid fuel and in the vapour phase; Measurement methods for H2S in marine fuel and in the vapour phase; Interpretation of results and guidance on maximum H2S levels; and Guidelines for the safe handling of liquid petroleum products that may contain H2S. Importantly, the report reinforces the need for safe handling procedures , training, and personnel protection when transferring or storing fuels that may contain H2S, rather than relying only on a measured H2S level in the liquid product.

  20. Kvalitetsvurderingssystem for habitatdirektivets marine naturtyper

    DEFF Research Database (Denmark)

    Dahl, K.; Larsen, M. M.; Rasmussen, M. B.;

    26. marts 2004 er der udgivet en engelsk version (bl.a udvidet med en længere beskrivelse af overvågningsprogrammet) i NERI Technical Report no. 488: Tools to assess the conservation status of marine Annex 1 habitats in Special Areas of Conservation. Phase 1: Identification of potential indicators...

  1. Perspectives in Marine Citizen Science

    OpenAIRE

    Michael Bear

    2015-01-01

    Citizen science can be defined as the process by which any non-scientist collects data or uses the scientific method under the guidance or mentorship of a scientist. This article presents an overview of several marine citizen-science projects as practiced by three non-profit organizations.

  2. Sunnyvale Marine Climate Deep Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Siddiqui, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, B. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2014-11-01

    The Alliance for Residential Building Innovation (ARBI) and Allen Gilliland of One Sky Homes collaborated on a marine climate retrofit project designed to meet both Passive House (PH) and Building America program standards. The scope included sealing, installing wall, roof and floor insulation (previously lacking), replacing windows, upgrading the heating and cooling system, and installing mechanical ventilation.

  3. Sunnyvale Marine Climate Deep Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    German, A.; Siddiqui, A.; Dakin, B.

    2014-11-01

    The Alliance for Residential Building Innovation (ARBI) and Allen Gilliland of One Sky Homes collaborated on a marine climate retrofit project designed to meet both Passive House (PH) and Building America (BA) program standards. The scope included sealing, installing wall, roof and floor insulation (previously lacking), replacing windows, upgrading the heating and cooling system, and installing.

  4. Perspectives in Marine Citizen Science.

    Science.gov (United States)

    Bear, Michael

    2016-03-01

    Citizen science can be defined as the process by which any non-scientist collects data or uses the scientific method under the guidance or mentorship of a scientist. This article presents an overview of several marine citizen-science projects as practiced by three non-profit organizations. PMID:27047591

  5. Investigating the Marine Environment and Its Resources, Part II.

    Science.gov (United States)

    Lien, Violetta F.

    This is the second of two volumes comprising a resource unit designed to help students become more knowledgeable about the marine environment and its resources. Included in this volume are discussions of changes in the human and marine environment, human needs, marine resources, living marine resources, marine transportation, marine energy…

  6. Petroleum biodegradation in marine environments.

    Science.gov (United States)

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  7. Global marine radioactivity database (GLOMARD)

    International Nuclear Information System (INIS)

    The GLOMARD stores all available data on marine radioactivity in seawater, suspended matter, sediments and biota. The database provides critical input to the evaluation of the environmental radionuclide levels in regional seas and the world's oceans. It can be used as a basis for the assessment of the radiation doses to local, regional and global human populations and to marine biota. It also provides information on temporal trends of radionuclide levels in the marine environment and identifies gaps in available information. The database contains information on the sources of the data; the laboratories performing radionuclide analysis; the type of samples (seawater, sediment, biota) and associated details (such as volume and weight); the sample treatment, analytical methods, and measuring instruments; and the analysed results (such as radionuclide concentrations, uncertainties, temperature, salinity, etc.). The current version of the GLOMARD allows the input, maintenance and extraction of data for the production of various kinds of maps using external computer programs. Extracted data are processed by these programs to produce contour maps representing radionuclide distributions in studied areas. To date, development work has concentrated on the Barents and Kara Seas in the Arctic and the Sea of Japan in the northwest Pacific Ocean, in connection with the investigation of radioactive waste dumping sites, as well as on marine radioactivity assessment of the Mururoa and Fangataufa nuclear weapons tests sites in French Polynesia. Further data inputs and evaluations are being carried out for the Black and Mediterranean Seas. In the framework of the project on Worldwide Marine Radioactivity Studies, background levels of 3H, 90Sr, 137Cs and 239,240Pu in water, sediment and biota of the world's oceans and seas will be established

  8. Proceedings of the 2008 marine biodiesel symposium

    International Nuclear Information System (INIS)

    In addition to producing lower hydrocarbon emissions, marine biodiesel is biodegradable and does not harm fish. This symposium was held to discuss current marine biodiesel applications and examine methods of increasing the use of biodiesel in marine environments in British Columbia (BC). Biofuel policies and mandates in the province were reviewed, and methods of expanding the biodiesel market were explored. Updates on the use of biodiesel in ferries, tugboats, and smaller marine diesel engine applications were provided. Biodiesel projects in the United States were discussed. The environmental impacts of marine biodiesel were evaluated, and federal policies and standards for biodiesel were also outlined. The symposium was divided into the following 5 main sessions: (1) policy, (2) overviews, (3) using biodiesel in marine engines, (4) biodiesel in larger marine vessels, and (5) biodiesel quality and environmental considerations. The conference featured 13 presentations, of which 4 have been catalogued separately for inclusion in this database. tabs., figs

  9. China Lags behind in Marine Resources Technology

    Institute of Scientific and Technical Information of China (English)

    卢布; 杨瑞珍; 陈印军; 吴凯; 张燕卿

    2007-01-01

    With the growing need for resources brought about by economic development, countries throughout the world have attached greater importance to the development and exploitation of marine resources.However,the scope and sphere of marine resources development are limited by the development level of marine resources technology.This paper introduces the achievements and problems of China’s marine resources development and exploitation,as well as the achievements,advantages and disadvantages in the scientific and technological development of our marine resources.It also discusses the general aims,key fields,preferred options and advanced techniques in the development of marine resources technology during the 11th Five-Year Plan,and offers policy suggestions for enhancing the creative abilities of marine resources technology.

  10. Marine (Brander-Smith report) and non-marine spills

    International Nuclear Information System (INIS)

    Current activities related to Canada's Green Plan are reviewed in the area of research on, and response to, marine and non-marine spills. The Emergency Response section of Environment Canada's Conservation and Protection Service has had a 130% increase in funding and 50% increase in personnel resources. Two thirds of these resources are assigned to regional operations where spill incidents occur and the rest to research. The section's first priority is to improve its spill prevention program. A national standard for emergency planning for industry has been prepared and thousands of copies have been sold. A Canada-USA joint inland pollution contingency plan will be established and training programs on response to oil and hazardous chemical spills has been implemented. Resources applied to spill response have also increased 150%; a computerized communications network has been provided for spill response personnel, with the aim to develop a single national spill reporting system. In terms of policy initiatives, amendments are being made to the Canada Shipping Act that will require on-board pollution emergency plans for ships operating in Canadian waters. A liability and compensation regime for chemical spills is being considered, as well as reimposition of a levy on petroleum products that resulted in creation of a ship-source oil pollution fund. Radar-based traffic control systems for heavily congested marine areas, electronic charting, and increased inspection of ships are among the spill prevention initiatives in progress. Research is being conducted on mapping environmentally sensitive shorelines and in oil spill cleanup methods

  11. Problems of toxicants in marine food products. 1. Marine biotoxins.

    Science.gov (United States)

    Bagnis, R; Berglund, F; Elias, P S; van Esch, G J; Halstead, B W; Kojima, K

    1970-01-01

    The expansion of marine fisheries into tropical waters, which is now occurring, will increase the risks of widespread poisonings because of the abundance of biotoxins in warm-water organisms. However, toxic marine organisms are not only a health hazard but also a possible source of new pharmaceutical products.A classification of marine intoxicants is given in this paper with special reference to the oral biotoxins which will be of primary concern in the expansion of warm-water fisheries. The biotoxins are both invertebrate (e.g., molluscs, arthropods) and vertebrate (mostly fishes) in origin. Biotoxications of vertebrate origin may be caused by the muscles, the gonads or the blood of certain fishes or by special poison glands not equipped with traumagenic devices. (Venomous fishes, having poison glands and traumagenic spines, etc., are of no direct concern as oral intoxicants.)The ichthyosarcotoxic fishes, in which the flesh is poisonous, appear to constitute the most significant health hazard. A list of fishes reported as causing ciguatera poisoning (one of the most serious and widespread forms of ichthyosarcotoxism) is included in this paper.

  12. The Genome of the Epsilonproteobacterial Chemolithoautotroph Sulfurimonas dentrificans

    Energy Technology Data Exchange (ETDEWEB)

    USF Genomics Class; Sievert, Stefan M.; Scott, Kathleen M.; Klotz, Martin G.; Chain, Patrick S.G.; Hauser, Loren J.; Hemp, James; Hugler, Michael; Land, Miriam; Lapidus, Alla; Larimer, Frank W.; Lucas, Susan; Malfatti, Stephanie A.; Meyer, Folker; Paulsen, Ian T.; Ren, Qinghu; Simon, Jorg

    2007-08-08

    Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This genome has many features, including a larger size (2.2 Mbp), that suggest a greater degree of metabolic versatility or responsiveness to the environment than seen for most of the other sequenced epsilonproteobacteria. A branched electron transport chain is apparent, with genes encoding complexes for the oxidation of hydrogen, reduced sulfur compounds, and formate and the reduction of nitrate and oxygen. Genes are present for a complete, autotrophic reductive citric acid cycle. Many genes are present that could facilitate growth in the spatially and temporally heterogeneous sediment habitat from where Sulfurimonas denitrificans was originally isolated. Many resistance-nodulation-development family transporter genes (10 total) are present; of these, several are predicted to encode heavy metal efflux transporters. An elaborate arsenal of sensory and regulatory protein-encoding genes is in place, as are genes necessary to prevent and respond to oxidative stress.

  13. Protection Of Chemolithoautotrophic Bacteria Exposed To Simulated Mars Environmental Conditions

    OpenAIRE

    Gómez, Felipe; Mateo-Martí, Eva; Prieto-Ballesteros, Olga; Martín-Gago, Jose; Amils, Ricardo

    2010-01-01

    Abstract Current surface conditions (strong oxidative atmosphere, UV radiation, low temperatures and xeric conditions) on Mars are considered extremely challenging for life. The question is whether there are any features on Mars that could exert a protective effect against the sterilizing conditions detected on its surface. Potential habitability in the subsurface would increase if the overlaying material played a protective role. With the aim of evaluating this possibility we stud...

  14. Cavitation simulation on marine propellers

    DEFF Research Database (Denmark)

    Shin, Keun Woo

    Cavitation on marine propellers causes thrust breakdown, noise, vibration and erosion. The increasing demand for high-efficiency propellers makes it difficult to avoid the occurrence of cavitation. Currently, practical analysis of propeller cavitation depends on cavitation tunnel test, empirical...... developed in the last decade. They show the potential for the simulation of propeller cavitation with robustness, but they are still to be more proved for practical applications. In the present work, hydrodynamic and numerical characteristics of several cavitation models developed for a viscous flow solver...... are investigated, and one of the cavitation models is verified for the cavitation simulation on marine propellers. Three cavitation models with a vapor transport equation and a cavitation model with a barotropic state law are implemented in the in-house RANS solver, EllipSys. The numerical results for cavitating...

  15. Parasites in marine food webs

    Science.gov (United States)

    Lafferty, Kevin D.

    2013-01-01

    Most species interactions probably involve parasites. This review considers the extent to which marine ecologists should consider parasites to fully understand marine communities. Parasites are influential parts of food webs in estuaries, temperate reefs, and coral reefs, but their ecological importance is seldom recognized. Though difficult to observe, parasites can have substantial biomass, and they can be just as common as free-living consumers after controlling for body mass and trophic level. Parasites have direct impacts on the energetics of their hosts and some affect host behaviors, with ecosystem-level consequences. Although they cause disease, parasites are sensitive components of ecosystems. In particular, they suffer secondary extinctions due to biodiversity loss. Some parasites can also return to a system after habitat restoration. For these reasons, parasites can make good indicators of ecosystem integrity. Fishing can indirectly increase or decrease parasite populations and the effects of climate change on parasites are likely to be equally as complex.

  16. Paleoecologic Megatrends in Marine Metazoa

    Science.gov (United States)

    Bush, Andrew M.; Bambach, Richard K.

    2011-05-01

    Since their appearance in the Neoproterozoic, marine metazoan ecosystems have increased in ecological diversity, complexity, energy use, motility, predation, infaunality, and biological disturbance. A common theme is an increase in organismal control over internal physiology and the external environment. Often, these changes have been examined in the context of discrete events (e.g., the Cambrian Explosion, Mesozoic Marine Revolution), but they may represent linked, ongoing megatrends. This review examines changes in ecological composition in the context of changes in taxonomic composition, as represented by a more detailed version of Sepkoski's evolutionary fauna analysis. Ecological change occurred during major radiations and extinctions, as well as between them. Due to its ecological selectivity, the Permian-Triassic extinction had particularly significant ecological effects on the biota. Recoveries from mass extinctions may be important episodes of ecological change. Further research could help elucidate the fundamental causes of long-term ecological change, including any role played by the environment.

  17. Biological importance of marine algae

    OpenAIRE

    Ali A. El Gamal

    2009-01-01

    Marine organisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. Algae can be classified into two main groups; first one is the microalgae, which includes blue green algae, dinoflagellates, bacillariophyta (diatoms)… etc., and second one is macroalgae (seaweeds) which includes green, brown and red algae. The microalgae phyla have been recognized to provide chemical and pharmacological...

  18. Eutrophication, marine biotoxins, human health.

    Science.gov (United States)

    Viviani, R

    1992-01-01

    Eutrophication phenomena in marine coastal waters can today be explained on the basis of natural or anthropogenic causes. Undesirable effects and also sanitary problems in both types of eutrophication are often produced, but they may differ greatly in frequency and significance. Some algal biotoxins can affect both marine animals and man, whilst others affect man alone. From data currently available it appears that the sanitary state of man can be affected through the digestive, respiratory and cutaneous apparatus. Four main dinoflagellate biointoxications are now recognized: paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), diarrhoetic shellfish poisoning (DSP), and venerupin poisoning. Other biointoxications are due to a diatom bloom responsible for amnesic shellfish poisoning (ASP) and to blue algae blooms which have effects on the skin and the respiratory tract. All these marine toxins are considered and particular attention is paid to: producing organisms, chemistry of the components, compromised sea foods, methods of analysis, occurrence worldwide, human intoxications, toxicology and mechanism of action on a molecular level, therapeutical notes, tolerance levels and remarks on safety. Attention is also paid to the relationship between the anthropogenic eutrophication and PSP and DSP since these are the most widespread biointoxications from toxic marine dinoflagellates in the world today and for which the European Economic Community (EEC) is proposing health legislation such as tolerance limits and methods for official analysis. In view of the harmful potential of coastal anthropogenic eutrophication, the main current committment of various countries concerns control. Finally, it is important to develop a suitable monitor research system using all the specific standards of allowed toxic substances, and also research on effective antiodotes against all biotoxins.

  19. Cobalt and marine redox evolution

    OpenAIRE

    Swanner, Elizabeth D.; Planavsky, Noah J.; Lalonde, Stefan; Robbins, Leslie J.; Bekker, Andrey; Rouxel, Olivier; Saito, Mak A.; Kappler, Andreas; Mojzsis, Stephen J.; Konhauser, Kurt O.

    2014-01-01

    Cobalt (Co) is a bio-essential trace element and limiting nutrient in some regions of the modern oceans. It has been proposed that Co was more abundant in poorly ventilated Precambrian oceans based on the greater utilization of Co by anaerobic microbes relative to plants and animals. However, there are few empirical or theoretical constraints on the history of seawater Co concentrations. Herein, we present a survey of authigenic Co in marine sediments (iron formations, authigenic pyrite and b...

  20. Mixotrophy in the Marine Plankton

    DEFF Research Database (Denmark)

    Stoecker, Diane K.; Hansen, Per Juel; Caron, David;

    2016-01-01

    Mixotrophs are important components of the bacterioplankton, phytoplankton, microzooplankton, and (sometimes) zooplankton in coastal and oceanic waters. Bacterivory among the phytoplankton may be important for alleviating inorganic nutrient stress and may increase primary production in oligotroph....... Modeling has indicated that mixotrophy has a profound impact on marine planktonic ecosystems and may enhance primary production, biomass transfer to higher trophic levels, and the functioning of the biological carbon pump....

  1. Sulfated compounds from marine organisms.

    Science.gov (United States)

    Kornprobst, J M; Sallenave, C; Barnathan, G

    1998-01-01

    More than 500 sulfated compounds have been isolated from marine organisms so far but most of them originate from two phyla only, Spongia and Echinodermata. The sulfated compounds are presented according to the phyla they have been identified from and to their chemical structures. Biological activities, when available, are also given. Macromolecules have also been included in this review but without structural details. PMID:9530808

  2. Stemming Epigenetics in Marine Stramenopiles

    OpenAIRE

    Maumus, Florian; Rabinowicz, Pablo; Bowler, Chris; Rivarola, Maximo

    2011-01-01

    Epigenetics include DNA methylation, the modification of histone tails that affect chromatin states, and small RNAs that are involved in the setting and maintenance of chromatin modifications. Marine stramenopiles (MAS), which are a diverse assemblage of algae that acquired photosynthesis from secondary endosymbiosis, include single-celled organisms such as diatoms as well as multicellular forms such as brown algae. The recent publication of two diatom genomes that diverged ~90 million years ...

  3. Collocations in Marine Engineering English

    Directory of Open Access Journals (Sweden)

    Mirjana Borucinsky

    2016-05-01

    Full Text Available Collocations are very frequent in the English language (Hill, 2000, and they are probably the most common and most representative of English multi-word expressions (Lewis, 2000. Furthermore, as a subset of formulaic sequences, collocations are considered to be a central aspect of communicative competence (Nation, 2001. Hence, the importance of teaching collocations in General English (GE as well as in English for Specific Purposes (ESP is undeniable. Understanding and determining the relevant collocations and their mastery are of “utmost importance to a ME instructor” (Cole et al., 2007, p. 137, and collocations are one of the most productive ways of enriching vocabulary and terminology in modern ME. Vişan & Georgescu (2011 have undertaken a relevant study on  collocations and “collocational competence” on board ships, including mostly nautical terminology. However, no substantial work on collocations in Marine Engineering English as a sub-register of ME has been carried out. Hence, this paper tries to determine the most important collocations in Marine Engineering English, based on a small corpus of collected e-mails. After determining the most relevant collocations, we suggest how to implement these in the language classroom and how to improve the collocational competence of marine engineering students.

  4. Secondary metabolites from marine microorganisms

    Directory of Open Access Journals (Sweden)

    KELECOM ALPHONSE

    2002-01-01

    Full Text Available After 40 years of intensive research, chemistry of marine natural products has become a mature field. Since 1995, there are signals of decreased interest in the search of new metabolites from traditional sources such as macroalgae and octocorals, and the number of annual reports on marine sponges stabilized. On the contrary, metabolites from microorganisms is a rapidly growing field, due, at least in part, to the suspicion that a number of metabolites obtained from algae and invertebrates may be produced by associated microorganisms. Studies are concerned with bacteria and fungi, isolated from seawater, sediments, algae, fish and mainly from marine invertebrates such as sponges, mollusks, tunicates, coelenterates and crustaceans. Although it is still to early to define tendencies, it may be stated that the metabolites from microorganisms are in most cases quite different from those produced by the invertebrate hosts. Nitrogenated metabolites predominate over acetate derivatives, and terpenes are uncommon. Among the latter, sesquiterpenes, diterpenes and carotenes have been isolated; among nitrogenated metabolites, amides, cyclic peptides and indole alkaloids predominate.

  5. Marine geomorphometry: Overview and opportunities.

    Science.gov (United States)

    Micallef, Aaron; Lecours, Vincent; Dolan, Margaret; Lucieer, Vanessa

    2016-04-01

    Multibeam echosounder data comprise the primary source for digital terrain models of the seafloor. Recent advances in seafloor surveying technologies have resulted in a dramatic increase in the quantity and resolution of multibeam echosounder data, prompting a renewed interest in employing geomorphometric techniques to investigate the seafloor. Marine geomorphometric techniques are not as varied and as extensively applied as in terrestrial environments. This is due to the difficultly with capturing terrain variability underwater, since changes in topography are more subdued in comparison to terrestrial landscapes. Issues related to scale are also relevant in submarine settings, but they manifest themselves differently due to the differences in input data. In the last decade, a suite of marine geomorphometric techniques have been developed - terrain attributes, feature-based quantitative representation, automated classification - and employed to investigate a wide range of phenomena - seafloor landforms and geomorphic processes, geohazards, hydrodynamics, habitats. This contribution provides an overview of progress made in marine geomorphometry in the last decade as well as highlights the opportunities and challenges faced by this thriving field of research in the near future.

  6. Theory and Practice of Marine Regional Management in China

    OpenAIRE

    JI, Shangjie; Qu, Qunzhen

    2014-01-01

    With the development of marine economy in coastal provinces and cities, there comes a series of environmental problems. Marine regional management, as a completely new marine management mode, transforms traditional management mode and can protect marine ecosystem. Thus, the marine regional management is feasible and applicable in China. This paper firstly discussed connotation and development of the marine regional management in China and pointed that the marine regional management is integra...

  7. SUSTAINABLE DEVELOPMENT OF MARINE ECONOMY IN CHINA

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yao-guang; DONG Li-jing; YANG Jun; WANG Sheng-yun; SONG Xin-ru

    2004-01-01

    China is a large marine country. Developing marine economy is an effective way to solve a series of problems with which man is faced, such as the want of natural resources, space limitation, the environmental deterioration, etc. This article analyzes the rich resources of marine biology, harbor, offshore oil and natural gas and coastal tourism resources in China and describes the developing features and regional differences of marine economy. To realize the sustainable development of marine economy in China, what we need to do are as follows: 1) to list exploiting ocean into national development strategy; 2) to realize integrated economy of sea and land; 3) to develop ocean by science and technology; 4) to perfect legal institution of marine environment; 5) to establish new idea of sea defending.

  8. Nutraceutical and pharmacological implications of marine carbohydrates.

    Science.gov (United States)

    Pallela, Ramjee

    2014-01-01

    Current day's research has been focusing much on the potential pharmacological or nutraceutical agents of selective health benefits with less toxicity. As a consequence of increased demand of nutritional supplements of great medicinal values, development of therapeutic agents from natural sources, in particular, marine environment are being considered much important. A diverse array of marine natural products containing medicinally useful nutritional substances, i.e., marine nutraceuticals have been focused to the benefit of mankind. Carbohydrates, by being constituted in considerable amount of many marine organisms display several nutraceutical and pharmaceutical behavior to defend from various diseases. Moreover, the carbohydrates from algae as well as from shellfish wastes, like chitosan and its derivatives, showed tremendous applications in biology and biomedicine. In the current chapter, several of marine carbohydrates from various marine flora and fauna have been covered with their applications and prospects in the development of nutraceuticals and pharmaceuticals.

  9. Marine Model Trout Farms: developments in marine RAS

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg

    2011-01-01

    . This development and demonstration unit in commercial scale will during the next four years hopefully provide scientific and practical basis and support for further development in coming generations of Marine Model Trout Farms for large salmonids. The unit consist in the recirculation loop of one large fish tank...... will be focussed on rainbow trout production, mimicking the typical Danish net cage farming cycle, where the cages are stocked with fish of 750 – 1,000 g in April/May and all harvested before Christmas weighing some 4 kg/pcs. During these two years important production parameters such as growth-rate, feed...

  10. Theory and Practice of Marine Regional Management in China

    Institute of Scientific and Technical Information of China (English)

    Shangjie; JI; Qunzhen; QU

    2014-01-01

    With the development of marine economy in coastal provinces and cities,there comes a series of environmental problems. Marine regional management,as a completely new marine management mode,transforms traditional management mode and can protect marine ecosystem. Thus,the marine regional management is feasible and applicable in China. This paper firstly discussed connotation and development of the marine regional management in China and pointed that the marine regional management is integrated management of a certain marine region. Next,it summarized characteristics of the marine regional management at current stage,for example,land-based pollution of trans-geographic system and marine management under regional government cooperative mechanism. Finally,it came up with recommendations including combining theory and practice of the marine regional management,and establishing marine regional management system as soon as possible,to realize benign interaction and sustainable development of marine economy and ecological environment.

  11. A Marine Spatial Planning Framework for the Optimal Sitting of Marine Renewable Energy Installations

    DEFF Research Database (Denmark)

    Azzelino, A.; Kofoed, Jens Peter; Lanfredi, C.;

    2013-01-01

    considered through set of multiple indicators (e.g. sea bottom topography and characteristics, marine biodiversity, presence of vulnerable species). Environmental indicators are aggregated into environmental impact indexes that constitute the basis for evaluating the site suitability for Marine Renewable...

  12. Distribution and diversity of marine natural products from Indonesian marine organisms

    Institute of Scientific and Technical Information of China (English)

    MasteriaYunovilsa Putra; Tutik Murniasih

    2016-01-01

    Objective: To study the distribution and diversity of species and isolated molecules, according to their structure classes, from Indonesian marine organisms. Methods: This study was performed by using the SciFinder® database, MarinLit and references from relevant articles from 1980 to 2014 which collected all the scientific publications dealing with the isolation of chemical compounds from Indonesian marine macroorganisms and microorganisms. Results: The discovery of novel compounds from Indonesian marine organisms gave us a result of a total of 78 papers. Alkaloids, terpenoids and peptides (84, 67 and 15 new compounds, respectively) represented the three main chemical classes of compounds discovered from Indonesian marine organisms, and together with the other chemical classes showed a range of biological activities. Conclusions: The new marine compounds are mainly from sponges and soft corals. Alkaloids, terpenoids and peptides are the most prolific compounds isolated from Indonesian marine organisms. Most marine natural products from Indonesian organisms have been screened for anticancer or cytotoxicity activities.

  13. Marine Habitat Mapping for the Norwegian Sea

    OpenAIRE

    Noji, Thomas; Thorsnes, Terje; Fosså, Jan Helge

    2000-01-01

    An initiative is currently being taken by several Norwegian organizations to obtain funds to intensify ongoing investigations on marine sea-floor mapping off Norway. Led by the Geological Survey of Norway and Institute of Marine Research, planning during the last two years has led to the inception of a large-scale mapping project entitled “MAREANO - Marine Areal Database for the Norwegian Sea”. The investigation area covers 270 000 km2 of the shelf and deep sea off the central ...

  14. Swedish marine insurance between the World Wars

    OpenAIRE

    Petersson, Gustav Jakob

    2010-01-01

    The present licentiate thesis analyses developments in Swedish marine insurance during the interwar period, including both direct marine insurance and marine reinsurance. This is done in order to provide insights on how companies of a highly internationalised and vulnerable line of insurance were affected by and responded to new risks during a period of far-reaching international financial and economic crises. Finally, the consequences of new risks and strategies are assessed. This thesis arg...

  15. A General Business Model for Marine Reserves

    OpenAIRE

    Sala, Enric; Costello, Christopher; Dougherty, Dawn; Heal, Geoffrey; Kelleher, Kieran

    2013-01-01

    Marine reserves are an effective tool for protecting biodiversity locally, with potential economic benefits including enhancement of local fisheries, increased tourism, and maintenance of ecosystem services. However, fishing communities often fear short-term income losses associated with closures, and thus may oppose marine reserves. Here we review empirical data and develop bioeconomic models to show that the value of marine reserves (enhanced adjacent fishing + tourism) may often exceed the...

  16. Marine Litter as Habitat and Dispersal Vector

    OpenAIRE

    Kiessling, Tim; Gutow, Lars; THIEL Martin

    2015-01-01

    Floating anthropogenic litter provides habitat for a diverse community of marine organisms. A total of 387 taxa, including pro- and eukaryotic micro-organisms, seaweeds and invertebrates, have been found rafting on floating litter in all major oceanic regions. Among the invertebrates, species of bryozoans, crustaceans, molluscs and cnidarians are most frequently reported as rafters on marine litter. Microorganisms are also ubiquitous on marine litter although the composition of the microbial ...

  17. Marine Biotechnology: A New Vision and Strategy for Europe

    NARCIS (Netherlands)

    Querellou, J.; Børresen, T.; Boyen, C.; Dobson, A.; Höfle, M.; Ianora, A.; Jaspars, M.; Kijjoa, A.; Olafsen, J.; Rigos, G.; Wijffels, R.H.

    2010-01-01

    Marine Board-ESF The Marine Board provides a pan-European platform for its member organisations to develop common priorities, to advance marine research, and to bridge the gap between science and policy in order to meet future marine science challenges and opportunities. The Marine Board was establi

  18. Therapeutically Active Biomolecules from Marine Actinomycetes

    Directory of Open Access Journals (Sweden)

    Mani Jayaprakashvel

    2012-09-01

    Full Text Available For the past few centuries, the biological sources of terrestrial origin have been explored and exploited for bioactive metabolites. This has resulted in the stagnancy of discovering either novel compounds or compounds with novel bioactivities. Thus, researchers across the globe have started exploring our big Oceans, for the search of bioactive metabolites. During the past few decades, the research on bioactive metabolites from marine biological resources has geared up and among the sources marine actinomycetes are proved to be best. Marine actinomycetes, the filamentous bacteria from marine environment have been intensively studied for bioactive metabolites. The biological diversity of marine actinomycetes was found to be enormous, thanks to culture dependent and culture independent biodiversity approaches. This great diversity of marine actinomycetes has offered greater chemical diversity. The diverse chemical compounds of marine actinomycetes have been found to have various biological activities such as antimicrobial, anti-tumor, anti-malarial, anti-algal, antioxidant, anti-inflammatory etc. These various bioactive metabolites of marine actinomycetes are having scope for developing as potent therapeutic agents. The potential of marine actinomycetes is rightly realized though the current biological wealth of these organisms isrelatively unexplored.

  19. Marine habitat mapping at Labuan Marine Park, Federal Territory of Labuan, Malaysia

    Science.gov (United States)

    Mustajap, Fazliana; Saleh, Ejria; Madin, John; Hamid, Shahimah Abdul

    2015-06-01

    Marine habitat mapping has recently become essential in coastal marine science research. It is one of the efforts to understand marine ecosystems, and thus to protect them. Habitat mapping is integral to marine-related industries such as fisheries, aquaculture, forestry and tourism. An assessment of marine habitat mapping was conducted at Labuan Marine Park (LMP), a marine protected area in the Federal Territory of Labuan. It is surrounded by shallow water within its islands (Kuraman, Rusukan Kecil and Rusukan Besar) with an area of 39.7 km2. The objectives of the study are to identify the substrate and types of marine habitat present within the park. Side scan sonar (SSS) (Aquascan TM) was used to determine the substrates and habitat while ground truthings were done through field observation and SCUBA diving survey. Seabed classification and marine habitat was based on NOAA's biogeography program. Three substrate types (sand, rock, silt) were identified in this area. The major marine habitats identified are corals, macro algae and small patches of sea grass. The study area is an important refuge for spawning and juvenile fish and supports the livelihood of the coastal communities on Labuan Island. Therefore, proper management is crucial in order to better maintain the marine protected area. The findings are significant and provide detailed baseline information on marine habitat for conservation, protection and future management in LMP.

  20. 75 FR 49759 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to...

    Science.gov (United States)

    2010-08-13

    ... inducing mild temporary threshold shift (TTS), the mildest form of hearing impairment (a non-injurious... to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral... FR 32379). That notice described, in detail, Statoil's proposed activity, the marine mammal...

  1. Marine oil spill contingency planning

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    According to the practice researching and formulating "The Oil Spill Contingency Plan of South Chinese Sea", this paper analyses and discusses the structure, functions and main contents of marine oil spill contingency planning, programs the organizing and commanding system and emergency response system, and advances the planning and researching method to coordinate comprehensively and to design practically the detailed emergency response steps until to formulate the ease operating programs for the plan implementation (PPI) and the PPI to apply high-techniques supporting emergency administrations and response.

  2. Australian developments in marine science

    Science.gov (United States)

    Coffin, Millard F.

    2012-07-01

    Australia is an island nation with about two thirds of its jurisdiction underwater. On 25 May 2012, Australia instituted the Seas and Submerged Lands (Limits of Continental Shelf) Proclamation 2012, confirming areas of seabed where Australia has exclusive rights to explore and exploit marine resources. This proclamation follows recommendations by the Commission on the Limits of the Continental Shelf, a body established under the United Nations Convention on the Law of the Sea, confirming Australia's entitlement to extended continental shelf, i.e., that beyond 200 nautical miles from the coastline, of some 2.56 million square kilometers, excluding Australian Antarctic Territory [Symonds et al., 2009] (Figure 1a).

  3. Marine & Hydrokinetic Technologies (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-04-01

    This fact sheet describes the U.S. Department of Energy's Water Power Program. The program supports the development of advanced water power devices that capture energy from waves, tides, ocean currents, rivers, streams, and ocean thermal gradients. The program works to promote the development and deployment of these new technologies, known as marine and hydrokinetic technologies, to assess the potential extractable energy from rivers, estuaries, and coastal waters, and to help industry harness this renewable, emissions-free resource to generate environmentally sustainable and cost-effective electricity.

  4. Chemical ecology of marine plankton.

    Science.gov (United States)

    Schwartz, Emily R; Poulin, Remington X; Mojib, Nazia; Kubanek, Julia

    2016-07-28

    Covering: January 2013 to online publication December 2014This review summarizes recent research in the chemical ecology of marine pelagic ecosystems, and aims to provide a comprehensive overview of advances in the field in the time period covered. In order to highlight the role of chemical cues and toxins in plankton ecology this review has been organized by ecological interaction types starting with intraspecific interactions, then interspecific interactions (including facilitation and mutualism, host-parasite, allelopathy, and predator-prey), and finally community and ecosystem-wide interactions. PMID:27090772

  5. Ancient advice for modern mariners

    Science.gov (United States)

    Brooks, David A.

    Some unusual preparations may be advised for persons anticipating voyages in sailing research vessels. For example, cooking facilities on sailing ships tend to be of modest means, and a scientist embarking on such a vessel may wonder whether he should bring his own essential provisions. Casting about for ideas, I happened on some relevant advice from Benjamin Franklin, who was seldom reluctant to sermonize on matters at hand. In spite of his numerous Atlantic crossings, Franklin was humble about offering advice to mariners, who he realized were generally suspicious of landlubbers.

  6. A new marine propulsion system

    Institute of Scientific and Technical Information of China (English)

    HAN Wei-shi; LIU Tao

    2003-01-01

    A new marine propulsion system is proposed . A small liquid sodium cooled reactor acts as prime mover; alkali-metal thermal-to-electric conversion (AMTEC) cells are employed to convert the heat energy to electricity; superconducting magneto-hydrodynamic thruster combined with spray-water thruster works as propulsion. The configuration and characteristics of this system are described. Such a nuclear-powered propulsion system is not only free of noise, but also has high reliability and efficiency. It would be a preferable propulsion system for ships in the future.

  7. 33 CFR 151.3000 - Definition of marine debris for the purposes of the Marine Debris Research, Prevention, and...

    Science.gov (United States)

    2010-07-01

    ... the purposes of the Marine Debris Research, Prevention, and Reduction Act. 151.3000 Section 151.3000... Definition of Marine Debris for the Purposes of the Marine Debris Research, Prevention, and Reduction Act § 151.3000 Definition of marine debris for the purposes of the Marine Debris Research, Prevention,...

  8. Freshwater savings from marine protein consumption

    International Nuclear Information System (INIS)

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr−1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr−1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture. (paper)

  9. 76 FR 16434 - Merchant Marine Personnel Advisory Committee

    Science.gov (United States)

    2011-03-23

    ... SECURITY Coast Guard Merchant Marine Personnel Advisory Committee AGENCY: Coast Guard, DHS. ACTION... determined that the establishment of the Merchant Marine Personnel Advisory Committee (MERPAC) is necessary... of Committee: Merchant Marine Personnel Advisory Committee. ADDRESSES: If you desire to...

  10. 77 FR 65570 - Merchant Marine Personnel Advisory Committee: Intercessional Meeting

    Science.gov (United States)

    2012-10-29

    ... SECURITY Coast Guard Merchant Marine Personnel Advisory Committee: Intercessional Meeting AGENCY: Coast... of the Merchant Marine Personnel Advisory Committee (MERPAC) will meet to discuss Task Statement 80....S. merchant marine, including but not limited to training, qualifications,...

  11. Data categories for marine planning

    Science.gov (United States)

    Lightsom, Frances L.; Cicchetti, Giancarlo; Wahle, Charles M.

    2015-01-01

    The U.S. National Ocean Policy calls for a science- and ecosystem-based approach to comprehensive planning and management of human activities and their impacts on America’s oceans. The Ocean Community in Data.gov is an outcome of 2010–2011 work by an interagency working group charged with designing a national information management system to support ocean planning. Within the working group, a smaller team developed a list of the data categories specifically relevant to marine planning. This set of categories is an important consensus statement of the breadth of information types required for ocean planning from a national, multidisciplinary perspective. Although the categories were described in a working document in 2011, they have not yet been fully implemented explicitly in online services or geospatial metadata, in part because authoritative definitions were not created formally. This document describes the purpose of the data categories, provides definitions, and identifies relations among the categories and between the categories and external standards. It is intended to be used by ocean data providers, managers, and users in order to provide a transparent and consistent framework for organizing and describing complex information about marine ecosystems and their connections to humans.

  12. Marine living thing processing system

    International Nuclear Information System (INIS)

    Marine living things collected upon cleaning of a seawater intake channel are sent to a solid/liquid separator. Discharged liquids containing separated sludges enter a coagulation/precipitation vessel. Condensed sludges precipitated in the vessel are sent to a dehydrator and converted into dehydrated cakes. On the other hand, supernatants discharged from the coagulation/precipitation vessel are sent to an ultra-filtration vessel and an active carbon vessel and then discharged to the sea area at improved the water quality. Further, the dehydrated cakes comprising condensed sluges are dried by a dryer, burnt in an incinerator and then processed as wastes. On the other hand, solid materials separated by the solid/liquid separator such as shells, are crushed finely by the crusher, then dried by an air stream dryer, baked in a high temperature baking furnace to form quick lime. The quick lime is sent to a digester and modified by hydration into slaked lime and it is shipped as slaked lime products. This can simplify the control for the operation and reduce the running cost. Further, resources of marine living (shells) can be utilized. (I.N.)

  13. DNA Barcoding of Marine Metazoa

    Science.gov (United States)

    Bucklin, Ann; Steinke, Dirk; Blanco-Bercial, Leocadio

    2011-01-01

    More than 230,000 known species representing 31 metazoan phyla populate the world's oceans. Perhaps another 1,000,000 or more species remain to be discovered. There is reason for concern that species extinctions may outpace discovery, especially in diverse and endangered marine habitats such as coral reefs. DNA barcodes (i.e., short DNA sequences for species recognition and discrimination) are useful tools to accelerate species-level analysis of marine biodiversity and to facilitate conservation efforts. This review focuses on the usual barcode region for metazoans: a ˜648 base-pair region of the mitochondrial cytochrome c oxidase subunit I (COI) gene. Barcodes have also been used for population genetic and phylogeographic analysis, identification of prey in gut contents, detection of invasive species, forensics, and seafood safety. More controversially, barcodes have been used to delimit species boundaries, reveal cryptic species, and discover new species. Emerging frontiers are the use of barcodes for rapid and increasingly automated biodiversity assessment by high-throughput sequencing, including environmental barcoding and the use of barcodes to detect species for which formal identification or scientific naming may never be possible.

  14. Submersible Generator for Marine Hydrokinetics

    Energy Technology Data Exchange (ETDEWEB)

    Cinq-Mars, Robert S; Burke, Timothy; Irish, James; Gustafson, Brian; Kirtley, James; Alawa, Aiman

    2011-09-01

    A submersible generator was designed as a distinct and critical subassembly of marine hydrokinetics systems, specifically tidal and stream energy conversion. The generator is designed to work with both vertical and horizontal axis turbines. The final product is a high-pole-count, radial-flux, permanent magnet, rim mounted generator, initially rated at twenty kilowatts in a two-meter-per-second flow, and designed to leverage established and simple manufacturing processes. The generator was designed to work with a 3 meter by 7 meter Gorlov Helical Turbine or a marine hydrokinetic version of the FloDesign wind turbine. The team consisted of experienced motor/generator design engineers with cooperation from major US component suppliers (magnetics, coil winding and electrical steel laminations). Support for this effort was provided by Lucid Energy Technologies and FloDesign, Inc. The following tasks were completed: Identified the conditions and requirements for MHK generators. Defined a methodology for sizing and rating MHK systems. Selected an MHK generator topology and form factor. Completed electromechanical design of submersible generator capable of coupling to multiple turbine styles. Investigated MHK generator manufacturing requirements. Reviewed cost implications and financial viability. Completed final reporting and deliverables

  15. Alexandru A. Marin (1945 - 2005)

    CERN Document Server

    S. Ahlen; G. Mikenberg; F. Taylor; B. Zhou

    It is with great sorrow that we report that ATLAS Physicist Alexandru (Alex) A. Marin passed away November 14, 2005 in Geneva. He died after a courageous two-week struggle against necrotizing fasciitis, a very rare and rapidly progressing destructive infection. Employed by Boston University and working at Harvard University, Alex was a productive and popular member of the ATLAS muon detector group. He had been playing a leading role in the installation of end-cap muon chambers in Building 180 at CERN and was a long-term member of the ATLAS Muon Collaboration. After the Boston Muon Consortium (BMC) MDT chambers were constructed and commissioned, Marin relocated to CERN in May 2005 to take on installation and commissioning responsibilities of the US MDT endcap chambers. He had spent the previous seven years employed by Boston University as a physicist with the BMC, and had worked with Steve Ahlen, Peter Hurst, Rick Haggerty and many others to assemble and integrate end-cap muon chambers. His work was of th...

  16. The Carolina conference on marine biotechnology: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Frankenberg, D.

    1985-01-01

    This report summarizes proceedings of a Carolina Conference on Marine Biotechnology held March 24-26, 1985, at the University of North Carolina at Chapel Hill. This report consists of the responders' summary of each topic discussed. The topics presented were General Prospects for Marine Biotechnology, Bioactive Substances from Marine Organisms, Fundamental Processes in Marine Organisms as Guides for Biotechnology Development, Genetic Manipulation of Potential Use to Mariculture, Organisms Interactions with Marine Surfaces: Marine Glues, and Biomolecular Engineering Materials Applications.

  17. Future marine zooplankton research - a perspective

    DEFF Research Database (Denmark)

    Bathmann, U.; Bundy, M.H.; Clarke, M.E.;

    2001-01-01

    During the Second Marine Zooplankton Colloquium (MZC2) 3 issues were added to those developed 11 yr ago during the First Marine Zooplankton Colloquium (MZC1). First, we focused on hot spots, i.e., locations where zooplankton occur in higher than regular abundance and/or operate at higher rates, W...

  18. Does terrestrial epidemiology apply to marine systems?

    Science.gov (United States)

    McCallum, Hamish I.; Kuris, Armand M.; Harvell, C. Drew; Lafferty, Kevin D.; Smith, Garriet W.; Porter, James

    2004-01-01

    Most of epidemiological theory has been developed for terrestrial systems, but the significance of disease in the ocean is now being recognized. However, the extent to which terrestrial epidemiology can be directly transferred to marine systems is uncertain. Many broad types of disease-causing organism occur both on land and in the sea, and it is clear that some emergent disease problems in marine environments are caused by pathogens moving from terrestrial to marine systems. However, marine systems are qualitatively different from terrestrial environments, and these differences affect the application of modelling and management approaches that have been developed for terrestrial systems. Phyla and body plans are more diverse in marine environments and marine organisms have different life histories and probably different disease transmission modes than many of their terrestrial counterparts. Marine populations are typically more open than terrestrial ones, with the potential for long-distance dispersal of larvae. Potentially, this might enable unusually rapid propagation of epidemics in marine systems, and there are several examples of this. Taken together, these differences will require the development of new approaches to modelling and control of infectious disease in the ocean.

  19. 49 CFR 171.4 - Marine pollutants.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Marine pollutants. 171.4 Section 171.4... pollutants. (a) Except as provided in paragraph (c) of this section, no person may offer for transportation or transport a marine pollutant, as defined in § 171.8, in intrastate or interstate commerce...

  20. 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...

  1. A Marine Fisheries Program for the Nation.

    Science.gov (United States)

    Department of Commerce, Washington, DC.

    This government publication describing the national plan for marine fisheries is divided into two parts. The first part contains a statement by the Secretary of Commerce, Elliot L. Richardson; the goals for the national marine fisheries plan; a description of the six parts of the plan; and a cost estimate for the program. The goals for the plan…

  2. Marine microalgae attack and feed on metazoans

    DEFF Research Database (Denmark)

    Berge, Terje; Poulsen, Louise K.; Moldrup, Morten;

    2012-01-01

    and Karlodinium veneficum have caused fast paralysis and mortality of finfish and copepods in the laboratory, and have been associated with reduced metazooplankton biomass in-situ. Here we show that a strain of K. armiger (K-0688) immobilises the common marine copepod Acartia tonsa in a densitydependent manner...... in causing mortalities at several trophic levels in the marine food web...

  3. Construction and screening of marine metagenomic libraries

    DEFF Research Database (Denmark)

    Weiland, Nancy; Löscher, Carolin; Metzger, Rebekka;

    2010-01-01

    microbial consortia on marine tissues of multicellular organisms are rich sources for isolating novel bioactive compounds and genes. Here we describe the sampling, construction of large-insert metagenomic libraries from marine habitats and exemplarily one function based screen of metagenomic clones....

  4. Crustacean biodiversity through the marine fossil record

    NARCIS (Netherlands)

    Sepkoski Jr., J. John

    2000-01-01

    Approximately 2,600 genera of marine crustaceans have been recognized in the fossil record, and crustaceans constitute the major component of marine arthropod diversity from the mid-Paleozoic to the Recent. Despite problems of sporadic fossil preservation and/or taxonomic ambiguity, some general sta

  5. Science Ⅲ marine research ship delivered

    Institute of Scientific and Technical Information of China (English)

    Gong Wei

    2006-01-01

    @@ On August 18, China's most advanced marine research ship Science Ⅲ was commissioned into operation at Qingdao and became an official member of China's marine research fleet. Designed and built by CSIC, the ship was delivered at Shanghai to the Institute of Oceanology, Chinese Academy of Sciences.

  6. Career Education: The Marine Science Occupations Cluster.

    Science.gov (United States)

    Farning, Maxwell

    This paper discusses career opportunities in eight broad groups of marine science occupations: (1) harbor construction and maintenance, (2) ship construction, (3) merchant marine activities, (4) towboating, (5) longshoring, (6) fishing and fish farming, (7) petroleum and natural gas exploration and extraction, and (8) research activities. The…

  7. Marine Science Activities for Visually Impaired.

    Science.gov (United States)

    Schatz, Dennis; And Others

    These marine education materials are based on the approach that students learn best when given a multisensory experience. The activities are intended to develop such experiences for the visually impaired child. Activities are intended to supplement an upper-elementary science curriculum or be the basis of a unit on marine biology. The guide is…

  8. Strengthened enforcement enhances marine sanctuary performance

    Directory of Open Access Journals (Sweden)

    Brendan P. Kelaher

    2015-01-01

    Full Text Available Marine sanctuaries are areas where the extraction of biota is not permitted. Although most marine sanctuaries have a positive influence on biotic communities, not all sanctuaries are meeting their conservation objectives. Amidst possible explanations (e.g., size, age and isolation, insufficient enforcement is often speculated to be a key driver of marine sanctuary underperformance. Despite this, there are few studies directly linking quantitative enforcement data to changes in biotic communities within marine sanctuaries. Here, we used an asymmetrical-BACI experimental design from 2006–2012 to test whether new enforcement initiatives enhanced abundances of target fishes and threatened species in an existing large sub-tropical marine sanctuary relative to areas open to fishing. Implementation of the new enforcement initiatives in 2010 was associated with a 201% increase in annual fine rate and a significant increase in target fish and elasmobranch abundance, as well as sightings of a critically-endangered shark, in the marine sanctuary relative to areas open to fishing. Overall, these results demonstrate that strengthening enforcement can have a rapid positive influence on target fish and perhaps threatened species in a subtropical marine sanctuary. From this, we contend that increased enforcement guided by risk-based compliance planning and operations may be a useful first step for improving underperforming marine sanctuaries.

  9. Reliability Based Management of Marine Fouling

    DEFF Research Database (Denmark)

    Faber, Michael Havbro; Hansen, Peter Friis

    1999-01-01

    obtained by the present model taking into account seasonal effects with those inherent in the current design specifications are made and criteria are formulated for removal of marine fouling taking into account seasonal differences in marine fouling. A methodology is outlined on how to establish new......The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification...... of uncertainties of a set of parameters. These are the seasonal variation of marine fouling parameters, the wave loading (taking into account the seasonal variation in sea-state statistics), and the effects of spatial variations and seasonal effects of marine fouling parameters. Comparison of design values...

  10. Intertemporal Choice of Marine Ecosystem Exploitation

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars

    the ability of an ecosystem to sustain total volume of harvest. Given the two aspects of intertemporal choice revealed by the model, the conclusion must be that the Fishing Down Marine Food Webs is probably driven by the current management's inability to conduct adequate intertemporal balancing; therefore......The term ``Fishing Down Marine Food Webs'' describes the gradual transition in landing from marine ecosystems towards organisms lower in the food web. To address this issue and the need to manage the marine ecosystem in a broader perspective, Ecosystem Management is recommended. Ecosystem...... empirically before drawing the conclusion that Fishing Down Marine Food Webs is economically detrimental can be established directly. Nevertheless, the model does reveal a need for intertemporal balance with respect to both fish size and harvest volume. These aspects are not addressed in any systematic way...

  11. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J;

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...... in planning the use of marine resources.......Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...... Sanctuaries. High variation in underlying species and cumulative impact distributions means that neither alone is sufficient for effective spatial management. Instead, comprehensive management approaches accounting for both cumulative human impacts and trade-offs among multiple stressors must be applied...

  12. Oxidative stability of marine phospholipids

    DEFF Research Database (Denmark)

    Lu, Henna Fung Sieng; Nielsen, Nina Skall; Baron, Caroline Pascale;

    Many studies have shown that marine phospholipids (MPL) provide more advantages than fish oil. They have better bioavailability, better resistance towards oxidation and higher content of eicosapentaenoic acids (EPA) and docosahexaenoic acids (DHA) than oily triglycerides (fish oil). The objective...... prepared in the form of emulsions by high pressure homogenizer. Then, the oxidative and hydrolytic stability of phospholipids was investigated by measurement of simple chemical analyses such as Peroxide Value and Free Fatty Acids, and 31PNMR after 32 days storage at 2ºC. The oxidative stability of MPL...... was further investigated through measurement of secondary volatile compounds by Solid Phase Microextraction at several time intervals. On the other hand, the Maillard reaction was investigated through the measurement of color changes and pyrrole content before and after 32 days storage. Preliminary result...

  13. Radionuclide interactions with marine sediments

    International Nuclear Information System (INIS)

    A critical review of the literature on the subject of the interactions of radionuclides with marine sediments has been carried out. On the basis of the information available, an attempt has been made to give ranges and 'best estimates' for the distribution ratios between seawater and sediments. These estimates have been based on an understanding of the sediment seawater system and the porewater chemistry and mineralogy. Field measurements, laboratory measurements and estimates based on stable-element geochemical data are all taken into account. Laboratory measurements include distribution-ratio and diffusion-coefficient determinations. The elements reviewed are carbon, chlorine, calcium, nickel, selenium, strontium, zirconium, niobium, technetium, tin, iodine, caesium, lead, radium, actinium, thorium, protactinium, uranium, neptunium, plutonium, americium and curium. (author)

  14. Marine Invertebrates: Communities at Risk

    Directory of Open Access Journals (Sweden)

    Jennifer Mather

    2013-06-01

    Full Text Available Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  15. Marine invertebrates: communities at risk.

    Science.gov (United States)

    Mather, Jennifer

    2013-01-01

    Our definition of the word 'animal' centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them.

  16. Marine invertebrates: communities at risk.

    Science.gov (United States)

    Mather, Jennifer

    2013-01-01

    Our definition of the word 'animal' centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical impact and chemical changes on the water severely damage these reefs, and may lead to the removal of these important habitats. Tiny pteropod molluscs live in huge numbers in the polar seas, and their fragile shells are particularly vulnerable to ocean acidification. Their removal would mean that fishes on which we depend would have a hugely diminished food supply. In the North Sea, warming is leading to replacement of colder water copepods by warmer water species which contain less fat. This is having an effect on the birds which eat them, who enrich the otherwise poor land on which they nest. Conversely, the warming of the water and the loss of top predators such as whales and sharks has led to an explosion of the jumbo squid of the Pacific coast of North America. This is positive in the development of a squid fishery, yet negative because the squid eat fish that have been the mainstay of the fishery along that coast. These examples show how invertebrates are key in the oceans, and what might happen when global changes impact them. PMID:24832811

  17. Fronts in Large Marine Ecosystems

    Science.gov (United States)

    Belkin, Igor M.; Cornillon, Peter C.; Sherman, Kenneth

    2009-04-01

    Oceanic fronts shape marine ecosystems; therefore front mapping and characterization are among the most important aspects of physical oceanography. Here we report on the first global remote sensing survey of fronts in the Large Marine Ecosystems (LME). This survey is based on a unique frontal data archive assembled at the University of Rhode Island. Thermal fronts were automatically derived with the edge detection algorithm of Cayula and Cornillon (1992, 1995, 1996) from 12 years of twice-daily, global, 9-km resolution satellite sea surface temperature (SST) fields to produce synoptic (nearly instantaneous) frontal maps, and to compute the long-term mean frequency of occurrence of SST fronts and their gradients. These synoptic and long-term maps were used to identify major quasi-stationary fronts and to derive provisional frontal distribution maps for all LMEs. Since SST fronts are typically collocated with fronts in other water properties such as salinity, density and chlorophyll, digital frontal paths from SST frontal maps can be used in studies of physical-biological correlations at fronts. Frontal patterns in several exemplary LMEs are described and compared, including those for: the East and West Bering Sea LMEs, Sea of Okhotsk LME, East China Sea LME, Yellow Sea LME, North Sea LME, East and West Greenland Shelf LMEs, Newfoundland-Labrador Shelf LME, Northeast and Southeast US Continental Shelf LMEs, Gulf of Mexico LME, and Patagonian Shelf LME. Seasonal evolution of frontal patterns in major upwelling zones reveals an order-of-magnitude growth of frontal scales from summer to winter. A classification of LMEs with regard to the origin and physics of their respective dominant fronts is presented. The proposed classification lends itself to comparative studies of frontal ecosystems.

  18. Analysis on the Development of Low-Carbon Marine Economy

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    From the perspective of low-carbon economy,the paper analyzes the factors that influencing the development of low carbon economy.It is showed that the damage of marine ecological environment results in the low ability of oceans in absorbing green gas;environmental pollution leads to lowering capacity of ocean to deal with the wastes;development of related marine industries brings deterioration of marine environment;changes of climate threat the healthy development of marine economy.The paper points out the development routines of marine low carbon economy:accelerating the innovation of energy techniques,exploring marine renewable green energies;planning scientifically and strengthening the protection and repairmen of marine environment;developing marine recycle economy,upgrading resources using efficiency;adjusting marine industrial structures and exploring greatly the marine low carbon industries;guiding industries to chase chances and accelerating the development of low-carbon marine economy.

  19. Marine Web Portal as an Interface between Users and Marine Data and Information Sources

    Science.gov (United States)

    Palazov, A.; Stefanov, A.; Marinova, V.; Slabakova, V.

    2012-04-01

    Fundamental elements of the success of marine data and information management system and an effective support of marine and maritime economic activities are the speed and the ease with which users can identify, locate, get access, exchange and use oceanographic and marine data and information. There are a lot of activities and bodies have been identified as marine data and information users, such as: science, government and local authorities, port authorities, shipping, marine industry, fishery and aquaculture, tourist industry, environmental protection, coast protection, oil spills combat, Search and Rescue, national security, civil protection, and general public. On other hand diverse sources of real-time and historical marine data and information exist and generally they are fragmented, distributed in different places and sometimes unknown for the users. The marine web portal concept is to build common web based interface which will provide users fast and easy access to all available marine data and information sources, both historical and real-time such as: marine data bases, observing systems, forecasting systems, atlases etc. The service is regionally oriented to meet user needs. The main advantage of the portal is that it provides general look "at glance" on all available marine data and information as well as direct user to easy discover data and information in interest. It is planned to provide personalization ability, which will give the user instrument to tailor visualization according its personal needs.

  20. Perceptions of ecological risk associated with introduced marine species in marine protected areas

    Directory of Open Access Journals (Sweden)

    Amy L. Trenouth

    2013-01-01

    Full Text Available The perception of ecological risks (impact and acceptability associated with introduced marine species (IMS, what demographic variablesinfluence those perceptions, respondent’s knowledge of IMS, and people’s support for controlling introduced marine species impacts on themarine environment was explored at three locations in Western Australia: Ningaloo Reef Marine Park, Rottnest Island Marine Reserve, andHamelin Bay. Recognition that introduced marine species are an issue at state, national and international levels exists; yet often marineprotected area management plans do not reflect this recognition. Therefore, we hypothesise that there is a lack of translation of concernregarding introduced marine species as a risk into tactical objectives within marine protected area management plans. This may be due to lowstakeholder perceptions of the risk posed by introduced marine species. Survey respondents had a high level (89% of self-rated awareness ofintroduced marine species and they also indicated (93% a willingness to support management interventions to prevent, or control the spreadof introduced marine species in Western Australia.Our results also indicate that gender (males and age (18–45 age group influenced respondents’ perception of risk (impact of IMS, yet noexamined demographic variables influenced respondents acceptability of risk. Furthermore, knowledge of introduced marine species,education level, and income variables did not influence respondents’ perception of risk (impact or acceptability. Understandingdemographic characteristics that influence participants perceptions related to introduced marine species can be useful for targeted,educational initiatives to reduce the likelihood of IMS incursions. This begins to smooth the way for management to proactively develop andimplement policies that are necessary to more fully protect the Western Australian marine environment.

  1. Marine Ecological Footprint of Italian Mediterranean Fisheries

    Directory of Open Access Journals (Sweden)

    Federica de Leo

    2014-10-01

    Full Text Available The capacity of marine and coastal ecosystems to sustain seafood production and consumption is seldom accounted for and is not included in the signals that guide economic development. In this article, we review estimates of marine and coastal areas aimed at sustaining catches for seafood consumption. The aim of this paper is the assessment of the interactions between the environment, intended as a set of ecological subsystems in natural equilibrium, including the marine ecosystem, and the process of fisheries systems. In particular we analyze fisheries in Italy, which is the third biggest economy and the greatest consumer of seafood in the Eurozone, conducting an in-depth analysis of the Marine Ecological Footprint (MEF that evaluates the marine ecosystem area exploited by human populations to supply seafood and other marine products and services. The positioning of Italian fisheries shows a level of sustainability next to the threshold value. The analysis in the present study highlights the importance of absolute indicators in providing rough estimates about human dependence on ecological systems and recognizes the importance of those indicators, such as the Marine Footprint (expressed in % of Primary Production Required/Primary Production, in ensuring a high level of precision and accuracy in quantifying human activity impact on the environment.

  2. Molecular ecology studies of marine Synechococcus

    Institute of Scientific and Technical Information of China (English)

    MA Ying; JIAO Nianzhi

    2004-01-01

    Cyanobacteria of the genus Synechococcus is a dominant component of microbial community in the world's oceans, and is a major contributor to marine primary productivity and thus plays an important role in carbon cycling in the oceans. Besides the ecological importance, the cultivability also made Synechococcus a very special group of marine microorganisms, which has attracted great attention from oceanographers and biologists. Great progress in the physiology, biochemistry and phylogeny of Synechococcus has been made since its discovery. We here review the current status of molecular ecology of marine Synechococcus and give a perspective into the future based on our understanding of the literature and our own work.

  3. Ecological Research Division, Marine Research Program

    Energy Technology Data Exchange (ETDEWEB)

    1980-05-01

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States.

  4. Smart Query Answering for Marine Sensor Data

    Directory of Open Access Journals (Sweden)

    Paulo de Souza

    2011-03-01

    Full Text Available We review existing query answering systems for sensor data. We then propose an extended query answering approach termed smart query, specifically for marine sensor data. The smart query answering system integrates pattern queries and continuous queries. The proposed smart query system considers both streaming data and historical data from marine sensor networks. The smart query also uses query relaxation technique and semantics from domain knowledge as a recommender system. The proposed smart query benefits in building data and information systems for marine sensor networks.

  5. Ecological Research Division, Marine Research Program

    International Nuclear Information System (INIS)

    This report presents program summaries of the various projects sponsored during 1979 by the Marine Research Program of the Ecological Research Division. Program areas include the effects of petroleum hydrocarbons on the marine environment; a study of the baseline ecology of a proposed OTEC site near Puerto Rico; the environmental impact of offshore geothermal energy development; the movement of radionuclides through the marine environment; the environmental aspects of power plant cooling systems; and studies of the physical and biological oceangraphy of the continental shelves bordering the United States

  6. Marine renewable energies. Stakes and technical solutions

    International Nuclear Information System (INIS)

    Marine renewable energies are able to supply carbon free energy from various ocean resources (tides, waves, currents, winds, salinity and temperature gradients). This sector, currently at an early stage of deployment, has good prospects of development in the coming years. ENEA releases a report on marine renewable energies giving a transversal vision of the associated stakes and prospects of development. Technical and economic characteristics, maturity level and specificities of each marine energy are analyzed. French and European sources of funding, regulatory framework and potential environmental and social impacts are also reported

  7. Marine mammals from the Miocene of Panama

    Science.gov (United States)

    Uhen, Mark D.; Coates, Anthony G.; Jaramillo, Carlos A.; Montes, Camilo; Pimiento, Catalina; Rincon, Aldo; Strong, Nikki; Velez-Juarbe, Jorge

    2010-12-01

    Panama has produced an abundance of Neogene marine fossils both invertebrate (mollusks, corals, microfossils etc.) and vertebrate (fish, land mammals etc.), but marine mammals have not been previously reported. Here we describe a cetacean thoracic vertebra from the late Miocene Tobabe Formation, a partial cetacean rib from the late Miocene Gatun Formation, and a sirenian caudal vertebra and rib fragments from the early Miocene Culebra Formation. These finds suggest that Central America may yet provide additional fossil marine mammal specimens that will help us to understand the evolution, and particularly the biogeography of these groups.

  8. 76 FR 34053 - Marine Mammals; File No. 16314

    Science.gov (United States)

    2011-06-10

    ... National Oceanic and Atmospheric Administration Marine Mammals; File No. 16314 AGENCY: National Marine.... SUPPLEMENTARY INFORMATION: The subject permit is requested under the authority of the Marine Mammal Protection... importing of marine mammals (50 CFR part 216). The applicant requests a five-year permit to conduct...

  9. Policy analysis for tropical marine reserves: challenges and directions

    NARCIS (Netherlands)

    Rudd, M.A.; Tupper, M.H.; Folmer, H.; Kooten, van G.C.

    2003-01-01

    Marine reserves are considered to be a central tool for marine ecosystem-based management in tropical inshore fisheries. The arguments supporting marine reserves are often based on both the nonmarket values of ecological amenities marine reserves provide and the pragmatic cost-saving advantages rela

  10. 46 CFR 199.145 - Marine evacuation system launching arrangements.

    Science.gov (United States)

    2010-10-01

    ... from any projections of the vessel's structure or equipment. (4) The marine evacuation system's passage... 46 Shipping 7 2010-10-01 2010-10-01 false Marine evacuation system launching arrangements. 199.145....145 Marine evacuation system launching arrangements. (a) Arrangements. Each marine evacuation...

  11. 46 CFR 4.03-2 - Serious marine incident.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Serious marine incident. 4.03-2 Section 4.03-2 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-2 Serious marine incident. The term serious marine incident includes...

  12. 49 CFR 176.70 - Stowage requirements for marine pollutants.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Stowage requirements for marine pollutants. 176.70... VESSEL General Handling and Stowage § 176.70 Stowage requirements for marine pollutants. (a) Marine pollutants must be properly stowed and secured to minimize the hazards to the marine environment...

  13. Marine Biology and Oceanography, Grades Nine to Twelve. Part II.

    Science.gov (United States)

    Kolb, James A.

    This unit, one of a series designed to develop and foster an understanding of the marine environment, presents marine science activities for students in grades 9-12. The unit, focusing on sea plants/animals and their interactions with each other and the non-living environment, has sections dealing with: marine ecology; marine bacteriology;…

  14. 22 CFR 228.23 - Eligibility of marine insurance.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Eligibility of marine insurance. 228.23 Section...-Related Services for USAID Financing § 228.23 Eligibility of marine insurance. The eligibility of marine... a cooperating country discriminates against marine insurance companies authorized to do business...

  15. Planning Marine Protected Areas: A Multiple Use Game

    NARCIS (Netherlands)

    Punt, M.J.; Weikard, H.P.; Groeneveld, R.A.; Ierland, van E.C.; Stel, J.

    2010-01-01

    The EU Marine Strategy Directive (MSD) has a regional focus in its implementation. The directive obliges countries to take multiple uses and the marine strategies of neighboring countries into account when formulating marine strategies and when designating marine protected areas (MPAs). We use game

  16. Marine conservation in the republic of South Africa with special reference to marine parks and reserves

    Directory of Open Access Journals (Sweden)

    G.A. Robinson

    1977-01-01

    Full Text Available Conservation in the Republic of South Africa (RSA is dominated by big game and terrestrial reserves. Protecting these, have been in existence for many years. Recently Man has turned his attention more and more to the sea and due to adverse effects of pollution, overexploitation and habitat destruction the marine environment is threatened. However, conservationists have learnt lessons about both terrestrial and marine ecosystem-destruction and are now demanding with increasing persistence the establishment of marine parks and reserves.

  17. Distribution and diversity of marine natural products from Indonesian marine organisms

    OpenAIRE

    Masteria Yunovilsa Putra; Tutik Murniasih

    2016-01-01

    Objective: To study the distribution and diversity of species and isolated molecules, according to their structure classes, from Indonesian marine organisms. Methods: This study was performed by using the SciFinder® database, MarinLit and references from relevant articles from 1980 to 2014 which collected all the scientific publications dealing with the isolation of chemical compounds from Indonesian marine macroorganisms and microorganisms. Results: The discovery of novel c...

  18. National Marine Recreational Fishing Expenditure Survey 2006

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine recreational fishing is a popular pastime across the United States that generates significant economic impacts to both local economies and to the nation. In...

  19. Marine biological data and information management system

    Digital Repository Service at National Institute of Oceanography (India)

    Sarupria, J.S.

    Indian National Oceanographic Data Centre (INODC) is engaged in developing a marine biological data and information management system (BIODIMS). This system will contain the information on zooplankton in the water column, zoobenthic biomass...

  20. A marine meteorological data acquisition system

    Digital Repository Service at National Institute of Oceanography (India)

    Desai, R.G.P.; Desa, E.; Vithayathil, G.

    A marine meteorological data acquisition system has been developed for long term unattended measurements at remote coastal sites, ocean surface platforms and for use on board research vessels. The system has an open and modular configuration...

  1. USCG Local Notice to Mariners: 2004

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  2. USCG Local Notice to Mariners: 2005

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  3. USCG Local Notice to Mariners: 2003

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  4. USCG Local Notice to Mariners: 2002

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  5. USCG Local Notice to Mariners: 2006

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  6. USCG Local Notice to Mariners: 1995

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  7. USCG Local Notice to Mariners: 1997

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  8. USCG Local Notice to Mariners: 2008

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  9. USCG Local Notice to Mariners: 2010

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  10. USCG Local Notice to Mariners: 1996

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  11. USCG Local Notice to Mariners: 2011

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  12. USCG Local Notice to Mariners: 1999

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  13. USCG Local Notice to Mariners: 2013

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  14. USCG Local Notice to Mariners: 2001

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  15. USCG Local Notice to Mariners: 1998

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  16. USCG Local Notice to Mariners: 2000

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  17. USCG Local Notice to Mariners: 2007

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  18. USCG Local Notice to Mariners: 2009

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  19. Atlantic Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in South Atlantic (Florida to Maryland) waters from 1994 to the...

  20. Marine information technology - Indian Ocean scenario

    Digital Repository Service at National Institute of Oceanography (India)

    Nayak, M.R.; Gouveia, A.D.; Navelkar, G.S.; Singh, K.

    the state of art and the need for the establishment of compatible means of high quality data collection, and exchange of marine information related to the Indian Ocean area. Oceanographic data visualisation-cum-analysis based sustainable decision making...

  1. Internet vis-a-vis marine biology

    Digital Repository Service at National Institute of Oceanography (India)

    Chavan, V.S.

    Internet is an amalgum of networks which reaches to more than 100 million people across the globe. The satellite-telecommunication based computer network web hosts information on every aspect of life. Marine biology related information too is being...

  2. Marine mammal observations, Amchitka Island, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Three marine mammals were regularly observed at Amchitka Island: sea otters (Enhydra lutris), Steller's sea lions (Eumetopias jubata), and harbor seals (Phoca...

  3. Grays Reef National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and othermanaged areas around the country. The legal boundaries of These sanctuaries are...

  4. Fagatele Bay National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  5. Thunder Bay National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and othermanaged areas around the country. The legal boundaries of These sanctuaries...

  6. Olympic Coast National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  7. Cordell Bank National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  8. Monitor National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  9. Florida Keys National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  10. Monterey Bay National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  11. Local Notice to Mariners by USCG District

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  12. 75 FR 18095 - America's Marine Highway Program

    Science.gov (United States)

    2010-04-09

    ...; integrate the marine highway into the transportation planning process; and research improvements in... highway into the transportation planning process, and research to improve efficiencies and environmental... organizations representing maritime and environmental interests and 12 State departments of transportation....

  13. SE Marine Mammal Histology/Tissue data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples are collected from stranded marine mammals in the Southeastern United States. These tissue samples are examined histologically and evaluated to...

  14. Population dynamics of marine birds: Annual report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The characteristic dynamics of Alaskan marine bird populations are being described from studies conducted at 12 OCSEAP-funded and 6nonOCSEAP-funded U. S. Fish and...

  15. Bacterial bioluminescence in marine pollution assessment

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Chandramohan, D.

    Warm water marine luminous bacterial species, particularly Vibrio harveyi, V. fischeri and Photobacterium leiognathi, are easy to isolate, maintain and handle in the laboratories without strict temperature requirements, which is an important...

  16. Geotechnical properties of Karwar marine clay

    Digital Repository Service at National Institute of Oceanography (India)

    Bhat, S.T.; Nayak, B.U.; Naik, R.L.

    Karwar marine clay possesses high plasticity characteristics with natural water content higher than the liquid limit. Liquidity index was as high as 1.7. Predominant clay mineral was kaolinite. Undrained shear strength showed an increasing trend...

  17. Preface to: Special issue on Marine mycology

    Digital Repository Service at National Institute of Oceanography (India)

    Raghukumar, C.

    Mycology for Indian Journal of Marine Sciences (IJMS). Dr. Vikram Agadi, Editor IJMS, agreed to bring out this issue and cooperated exceedingly well for bringing it out as scheduled. Dr. Chandralata Raghukumar National Institute of Oceanography...

  18. Channel Islands National Marine Sanctuary Boundary (polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of these sanctuaries are...

  19. Marine Geology Reports in the NGDC Archive

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Historic Marine Geologic data reports available are from academia, government, and non-U.S. sources. These reports were originally in paper or film form and were...

  20. Marine governance of European Seas: Introduction

    NARCIS (Netherlands)

    Raakjaer, J.; Tatenhove, van J.P.M.

    2014-01-01

    This introduction explains the context and structure of a block of articles developed as part of the governance work packages of the FP7 project: “Options for Delivering Ecosystem-based Marine management” (ODEMM).

  1. Marine Mammal Food Habits Reference Collections

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Marine Mammal Laboratory (NMML) Food Habits Reference Collection, containing over 8000 specimens of cephalopod beaks and fish bones and otoliths, is...

  2. BOEM Marine Hydrokinetic (MHK) Planning Areas

    Data.gov (United States)

    Bureau of Ocean Energy Management, Department of the Interior — This data set represents the most recent changes for the Marine Hydrokinetic (MHK Development Planning Areas in the Atlantic. )MHK Planning Areas in this dataset...

  3. Alaska Marine Mammal Strandings/Entanglements

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This database represents a summary of information on stranded marine mammals reported to NMFS throughout the State of Alaska in fulfillment of Title IV of the...

  4. Alaska Arctic marine fish ecology catalog

    Science.gov (United States)

    Thorsteinson, Lyman K.; Love, Milton S.

    2016-08-08

    The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation. 

  5. Marine bird and mammal data integration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuary Program (ONMS) updates and revises the management plans for each of its 13 sanctuaries. This process, which is open to the...

  6. National Marine Sanctuary Digital Boundary Files

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of these sanctuaries are...

  7. iMarine - data infrastructure enabling software ?

    OpenAIRE

    Simi, Manuele

    2012-01-01

    iMarine Data Infrastructure Enabling Software contains the description of software and pointers to the documentation and artifacts of the related components that comprise the e-Infrstructure Management suite delivered from M7 to M10 ?

  8. iMarine - Management report, November 2013

    OpenAIRE

    Candela, Leonardo; Castelli, Donatella; Coro, Gianpaolo; Ellenbroek, Anton; Fabriani, Paolo; Garavelli, Sara; Gerbesiotis, John; Kakaletris, George; Manzi, Andrea; Michel Assoumou, Jessica; Pagano, Pasquale (ISTI-CNR)

    2013-01-01

    This deliverables is a project management report describing the developments, achievement and identified risks of the iMarine project across all activities performed in the period July '13 (M21)-November '13 (M24).

  9. The technical aspect of iMarine

    OpenAIRE

    Pagano, Pasquale (ISTI-CNR)

    2014-01-01

    The presentation describes how iMarine is exploiting a Hybrid Data Infrastructure combining over 500 software components into a coherent and centrally managed system of hardware, software, and data resources

  10. iMarine - data infrastructure enabling software ?

    OpenAIRE

    Simi, Manuele; Farantatos, Gerasimos

    2012-01-01

    iMarine Data Infrastructure Enabling Software contains the description of software and pointers to the related documentation and artifacts of the components that comprise the e-Infrastructure Management suite delivered up to M6. ? ? ? ?

  11. Alabama 4-H Marine Pilot Manual.

    Science.gov (United States)

    Rawson, Mac; Trussell, Gale

    Brief descriptions and eight activities related to zooplankton, sharks, dune ecology, ocean currents, and sea products comprise this manual. Among the activities are harvesting seafood, making Japanese fish prints, and tracing marine currents with drift bottles. (WB)

  12. Alaska Arctic marine fish ecology catalog

    Science.gov (United States)

    2016-01-01

    The marine fishes in waters of the United States north of the Bering Strait have received new and increased scientific attention over the past decade (2005–15) in conjunction with frontier qualities of the region and societal concerns about the effects of Arctic climate change. Commercial fisheries are negligible in the Chukchi and Beaufort Seas, but many marine species have important traditional and cultural values to Alaska Native residents. Although baseline conditions are rapidly changing, effective decisions about research and monitoring investments must be based on reliable information and plausible future scenarios. For the first time, this synthesis presents a comprehensive evaluation of the marine fish fauna from both seas in a single reference. Although many unknowns and uncertainties remain in the scientific understanding, information presented here is foundational with respect to understanding marine ecosystems and addressing dual missions of the U.S. Department of the Interior for energy development and resource conservation. 

  13. NOAA and MMS Marine Minerals Geochemical Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Minerals Geochemical Database was created by NGDC as a part of a project to construct a comprehensive computerized bibliography and geochemical database...

  14. Marine outfall location off South Chennai

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Jayakumar, S.; AshokKumar, K.

    Disposal of industrial effluents into open sea envisages a through study of the marine environment in the vicinity of the outfall. Sufficient dilution and dispersion of the effluent has to take place before it reaches the shore. The required...

  15. Stellwagen Bank National Marine Sanctuary Boundary (polygon)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of National Marine Sanctuaries manages a system of sanctuaries and other managed areas around the country. The legal boundaries of These sanctuaries are...

  16. Seaweed: A valuable marine plant source

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.; Pereira, N.

    Seaweed, one of the components of seashore, is the most unique and important marine living resource. Its multi-ranged applications are of economic as well as ecological importance. These plants have been a source of food, feed and medicine...

  17. National Marine Recreational Fishing Expenditure Survey 2011

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine recreational fishing is a popular pastime across the United States that generates significant economic impacts to both local economies and to the nation. In...

  18. NCEP Real-time Marine Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly surface marine data gathered by NOAA's National Centers for Environmental Prediction. The basic observational data are edited, using a "trimming" procedure...

  19. USCG Local Notice to Mariners: 2012

    Data.gov (United States)

    Department of Homeland Security — The LNM is the primary means for disseminating information concerning aids to navigation, hazards to navigation, and other items of marine information of interest...

  20. Caribbean Marine Mammal Assessment Vessel Surveys

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets are a compilation of large vessel surveys for marine mammal stock assessments in Caribbean waters conducted during 2000-2001. These surveys were...