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22 results on '"IFREMER - Nantes"'

1. Characterization of New Oligosaccharides Obtained by An Enzymatic Cleavage of the Exopolysaccharide Produced by the Deep-Sea Bacterium Alteromonas infernus Using its Cell Extract

Author

Hélène Rogniaux, Katy Akoumany, David Ropartz, Sylvia Colliec-Jouault, Christine Delbarre-Ladrat, Laëtitia Marchand, Mathieu Fanuel, Muriel Pipelier, Corinne Sinquin, Agata Zykwinska, Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies [IFREMER, Nantes], Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), and Institut National de la Recherche Agronomique (INRA)

Subjects
glycosaminoglycan-mimetic, Pharmaceutical Science, Polysaccharide, Cleavage (embryo), Alteromonas infernus, 01 natural sciences, Analytical Chemistry, lcsh:QD241-441, Glycosaminoglycan, 03 medical and health sciences, lcsh:Organic chemistry, deep-sea bacterium, Drug Discovery, [CHIM]Chemical Sciences, structural analysis, Physical and Theoretical Chemistry, Lyase activity, 030304 developmental biology, mass spectrometry, chemistry.chemical_classification, 0303 health sciences, biology, 010405 organic chemistry, Depolymerization, Chemistry, exopolysaccharides, Organic Chemistry, Oligosaccharide, biology.organism_classification, 0104 chemical sciences, Enzyme, Biochemistry, 13. Climate action, Chemistry (miscellaneous), wild-type strain, enzymatic depolymerization, Molecular Medicine, Bacteria
Abstract

Bacteria from deep-sea hydrothermal vents constitute an attractive source of bioactive molecules. In particular, exopolysaccharides (EPS) produced by these bacteria become a renewable source of both biocompatible and biodegradable molecules. The low molecular weight (LMW) derivatives of the GY785 EPS produced by the deep-sea hydrothermal vent strain Alteromonas infernus have previously displayed some biological properties, similar to those of glycosaminoglycans (GAG), explored in cancer and tissue engineering. These GAG-mimetic derivatives are obtained through a free radical depolymerization process, which could, however, affect their structural integrity. In a previous study, we have shown that A. infernus produces depolymerizing enzymes active on its own EPS. In the present study, an enzymatic reaction was optimized to generate LMW derivatives of the GY785 EPS, which could advantageously replace the present bioactive derivatives obtained by a chemical process. Analysis by mass spectrometry of the oligosaccharide fractions released after enzymatic treatment revealed that mainly a lyase activity was responsible for the polysaccharide depolymerization. The repeating unit of the GY785 EPS produced by enzyme cleavage was then fully characterized.

Published
2019
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2. 3,4-Dideoxy-3,3,4,4-tetrafluoro- and 4-OH epimeric 3-deoxy-3,3-difluoro-α-GalCer analogues: Synthesis and biological evaluation on human iNKT cells stimulation

Author

Arnaud Tessier, Jézabel Rocher, Katy Akoumany, Allan Patinec, Virginie Blot, Didier Dubreuil, Jacques Le Pendu, Jean-Yves Le Questel, Bruno Linclau, Samuel Golten, Jérôme Graton, Muriel Pipelier, Denis Jacquemin, J.Y. Douillard, Jacques Lebreton, Chimie Et Interdisciplinarité : Synthèse, Analyse, Modélisation (CEISAM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Host-Pathogen Interactions in the Regulation of Immune Responses (CRCINA-ÉQUIPE 5), Centre de Recherche en Cancérologie et Immunologie Nantes-Angers (CRCINA), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Nantes - UFR de Médecine et des Techniques Médicales (UFR MEDECINE), Université de Nantes (UN)-Université de Nantes (UN)-Centre hospitalier universitaire de Nantes (CHU Nantes)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA), Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies [IFREMER, Nantes], and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)

Subjects
Models, Molecular, Stereochemistry, [SDV]Life Sciences [q-bio], Molecular Conformation, Receptors, Antigen, T-Cell, Galactosylceramides, 01 natural sciences, Work related, 03 medical and health sciences, chemistry.chemical_compound, Interferon-gamma, Amide, Drug Discovery, Electronic effect, [CHIM]Chemical Sciences, Humans, Receptor, Deoxygenation, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, Pharmacology, 0303 health sciences, Interleukin-13, biology, 010405 organic chemistry, Hydrogen bond, Organic Chemistry, T-cell receptor, Hydrogen Bonding, Stereoisomerism, General Medicine, 0104 chemical sciences, chemistry, CD1D, biology.protein, Natural Killer T-Cells, Antigens, CD1d, HeLa Cells, Protein Binding
Abstract

20 iNKT cells recognize CD1d/-galactosylceramide (-GalCer) complexes via their invariant 21 TCR receptor and stimulate the immune response. Many -GalCer analogues have been 22 investigated to interrogate this interaction. Following our previous work related to the 23 modification of the hydrogen bond network between -GalCer and CD1d, we have now 24 focused our attention on the synthesis of 3-deoxy-3,3-difluoro-and 3,4-dideoxy-3,3,4,4-25 tetrafluoro-α-GalCer analogues, and studied their ability to stimulate human iNKT cells. In 26 2 each case, deoxygenation at the indicated positions was accompanied by difluoro introduction 1 in order to evaluate the resulting electronic effect on the stability of the ternary 2 CD1d/Galcer/TCR complex which has been rationalized by modeling study. With deoxy-3 difluorination at the 3-position, the two epimeric 4-OH analogues were investigated to establish 4 their capacity to compensate for the lack of the hydrogen bond donating group at the 3-position. 5 The 3,4-dideoxytetrafluoro analogue was of interest to highlight the amide NH-bond hydrogen 6 bond properties. 7 8

Published
2019
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3. Modelling paralytic shellfish toxins (PST) accumulation in Crassostrea gigas by using Dynamic Energy Budgets (DEB)

Author

Yoann Thomas, Eric Rannou, Jonathan Flye-Sainte-Marie, Philippe Soudant, Emilien Pousse, Marianne Alunno-Bruscia, Hélène Hégaret, Caroline Fabioux, Ludovic Hermabessiere, Zouher Amzil, Gonçalo M. Marques, Justine Castrec, Malwenn Lassudrie, Laure Pecquerie, Fred Jean, Marc Long, Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Mathématiques de Bretagne Atlantique (LMBA), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD), Instituto Superior Técnico, Technical University of Lisbon, School of Chemistry [Wollongong], University of Wollongong [Australia], Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), ANR-10-LABX-0019,LabexMER,LabexMER Marine Excellence Research: a changing ocean(2010), ANR-13-CESA-0019,ACCUTOX,De la caractérisation des déterminants de l'accumulation des toxines paralysantes (PST) chez l'huître (Crassostrea gigas) au risque sanitaire pour l'homme dans son contexte sociétal(2013), Institut de Recherche pour le Développement (IRD)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Université de Brest (UBO)-Université de Bretagne Sud (UBS)-Centre National de la Recherche Scientifique (CNRS), Marine, Environment and Technology Center (MARATEC), School of Chemistry, University of Wollongong, Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université de Brest (UBO)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and ANR-11-LABX-0020,LEBESGUE,Centre de Mathématiques Henri Lebesgue : fondements, interactions, applications et Formation(2011)

Subjects
0106 biological sciences, Oyster, Alexandrium minutum, Dynamic energy budget, Paralytic shellfish toxins (PST), Zoology, Aquatic Science, Oceanography, 010603 evolutionary biology, 01 natural sciences, Modelling, chemistry.chemical_compound, biology.animal, medicine, Pacific oyster, 14. Life underwater, Ecology, Evolution, Behavior and Systematics, Shellfish, ComputingMilieux_MISCELLANEOUS, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography, Saxitoxin, [SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, biology, 010604 marine biology & hydrobiology, ACL, fungi, Dinoflagellate, food and beverages, Dynamic Energy Budget (DEB), biology.organism_classification, medicine.disease, [INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation, Shellfish poisoning, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, chemistry, [SDE]Environmental Sciences, Crassostrea, [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology, Clearance rate
Abstract

International audience; As other filter-feeders, Crassostrea gigas can concentrate paralytic shellfish toxins (PST) by consuming dino-flagellate phytoplankton species like Alexandrium minutum. Intake of PST in oyster tissues mainly results from feeding processes, i.e. clearance rate, pre-ingestive sorting and ingestion that are directly influenced by environmental conditions (trophic sources, temperature). This study aimed to develop a mechanistic model coupling the kinetics of PST accumulation and bioenergetics in C. gigas based on Dynamic Energy Budget (DEB) theory. For the first time, the Synthesizing Units (SU) concept was applied to formalize the feeding preference of oysters between non-toxic and toxic microalgae. Toxin intake and accumulation were both dependent on the physiological status of oysters. The accumulation was modelled through the dynamics of two toxin compartments: (1) a compartment of ingested but non-assimilated toxins, with labile toxins within the digestive gland eliminated via faeces production; (2) a compartment of assimilated toxins with a rapid detoxification rate (within a few days). Firstly, the DEB-PST model was calibrated using data from two laboratory experiments where oysters have been exposed to A. minutum. Secondly, it was validated using data from another laboratory experiment and from three field surveys carried out in the Bay of Brest (France) from 2012 to 2014. To account for the variability in PST content of A. minutum cells, the saxitoxin (STX) amount per energy units in a toxic algae (ppsT) was adjusted for each dataset. Additionally, the effects of PST on the oyster bioenergetics were calibrated during the first laboratory experiment. However, these effects were shown to depend on the strain of A. minutum. Results of this study could be of great importance for monitoring agencies and decision makers to identify risky conditions (e.g. production areas, seawater temperature), to properly assess detoxification step (e.g. duration, modalities) before any commercialization or to improve predictions regarding closing of shellfish areas.

Published
2019
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4. Oceanic mercury concentrations on both sides of the Strait of Gibraltar decreased between 1989 and 2012

Author

Bastien Thomas, Francesca Sprovieri, Philippe Courau, Daniel Cossa, Marie Boye, Nicolas Marusczak, Joël Knoery, Institut des Sciences de la Terre (ISTerre), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Science et Technologie de la Biomasse Marine, Nantes (IFREMER), Laboratoire de Science et Technologie de la Biomasse Marine, Biogéochimie et Ecotoxicologie (IFREMER BE), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institute of Atmospheric Pollution Research (IIA), Consiglio Nazionale delle Ricerche [Roma] (CNR), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Département Biogéochimie et Ecotoxicologie, Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire Biogéochimie des Contaminants Métalliques (LBCM), Biogéochimie et Ecotoxicologie (BE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and European Project: 265113,EC:FP7:ENV,FP7-ENV-2010,GMOS(2010)

Subjects
Mediterranean climate, 010504 meteorology & atmospheric sciences, Natural cycle, chemistry.chemical_element, North east, 010501 environmental sciences, 01 natural sciences, Earth and Planetary Sciences (miscellaneous), Mediterranean Sea, Ecosystem, 14. Life underwater, Atlantic Ocean, 0105 earth and related environmental sciences, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Global and Planetary Change, Gibraltar, Ecology, Aquatic ecosystem, Pelagic zone, Mercury, Mercury (element), Oceanography, chemistry, 13. Climate action, [SDU]Sciences of the Universe [physics], Bioaccumulation, [SDE]Environmental Sciences, Environmental science
Abstract

Mercury (Hg) is a toxic metal that threatens the health of aquatic ecosystems and fish consumers. Its natural cycle has been deeply perturbed by Anthropogenic Hg emissions have deeply perturbed its natural cycle, especially since the start of the Industrial Revolution circa 1850 CE. Anthropogenic Hg emissions from North America and Europe have decreased by a factor of two in the last decades following the implementation of strict regulations. The response of North Atlantic Ocean and Mediterranean waters to this decrease remains poorly documented by field observations. A comparison of results obtained between 1989 and 2012 shows a significant decrease of Hg concentrations in waters on both sides of the Strait of Gibraltar. West of Gibraltar, the Hg decrease ranges from ∼35 % in the upper North East Atlantic Deep Water to ∼50 % in the North East Atlantic Central Water. East of Gibraltar, the observed decrease is ∼30 % in the Western Mediterranean Deep Water. No decrease is observed in the deep Atlantic Ocean layer that formed before the industrial era. These results strongly substantiate the effectiveness of global anti-pollution policies on Hg contamination in oceanic waters. A consequent decline of Hg bioaccumulation in Northeastern Atlantic and Western Mediterranean pelagic ecosystems still requires verification.

Published
2019
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5. Unique Biosynthetic Pathway in Bloom-Forming Cyanobacterial Genus Microcystis Jointly Assembles Cytotoxic Aeruginoguanidines and Microguanidines

Author

Christian Hertweck, Claire Pancrace, Muriel Gugger, Enora Briand, Arthur Guljamow, Keishi Ishida, Nathalie Sassoon, Annika R. Weiz, Thibault Scalvenzi, Douglas Gatte Pichi, Elke Dittmann, Collection des Cyanobactéries, Institut Pasteur [Paris], Institut d'écologie et des sciences de l'environnement de Paris (iEES Paris), Institut National de la Recherche Agronomique (INRA)-Sorbonne Université (SU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Leibniz-Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Leibniz Institute for Natural Product Research and Infection Biology (Hans Knoell Institute), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), University of Potsdam, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], DFG-fundedCollaborative Research Centre ChemBioSys (SFB 1127, Institut Pasteur [Paris] (IP), University of Potsdam = Universität Potsdam, Institut d'écologie et des sciences de l'environnement de Paris (IEES (UMR_7618 / UMR_D_242 / UMR_A_1392 / UM_113) ), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), and Friedrich Schiller University Jena [Jena, Germany]

Subjects
0301 basic medicine, Cyanobacteria, Microcystis, Metabolite, [SDV]Life Sciences [q-bio], 01 natural sciences, Biochemistry, Genome, Guanidines, METABOLITES, 03 medical and health sciences, chemistry.chemical_compound, Nonribosomal peptide, ddc:570, RESOURCE, Gene cluster, Axenic, Institut für Biochemie und Biologie, chemistry.chemical_classification, biology, 010405 organic chemistry, Biological activity, PEPTIDES, General Medicine, Eutrophication, biology.organism_classification, [SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology, 6. Clean water, 0104 chemical sciences, 3. Good health, Biosynthetic Pathways, 030104 developmental biology, chemistry, 13. Climate action, ESCHERICHIA-COLI, DISCOVERY, Molecular Medicine, GENOMICS
Abstract

International audience; The cyanobacterial genus Microcystis is known to produce an elaborate array of structurally unique and biologically active natural products, including hazardous cyanotoxins. Cytotoxic aeruginoguanidines represent a yet unexplored family of peptides featuring a trisubstituted benzene unit and farnesylated arginine derivatives. In this study, we aimed at assigning these compounds to a biosynthetic gene cluster by utilizing biosynthetic attributes deduced from public genomes of Microcystis and the sporadic distribution of the metabolite in axenic strains of the Pasteur Culture Collection of Cyanobacteria. By integrating genome mining with untargeted metabolomics using liquid chromatography with mass spectrometry, we linked aeruginoguanidine (AGD) to a nonribosomal peptide synthetase gene cluster and coassigned a significantly smaller product to this pathway, microguanidine (MGD), previously only reported from two Microcystis blooms. Further, a new intermediate class of compounds named microguanidine amides was uncovered, thereby further enlarging this compound family. The comparison of structurally divergent AGDs and MGDs reveals an outstanding versatility of this biosynthetic pathway and provides insights into the assembly of the two compound subfamilies. Strikingly, aeruginoguanidines and microguanidines were found to be as widespread as the hepatotoxic microcystins, but the occurrence of both toxin families appeared to be mutually exclusive. M icrocystis is a dominant bloom-forming cyanobacterium occurring in temperate freshwater ecosystems. 1 The genus is infamous for the production of the well-known hepatotoxin microcystin. 2 Both blooms and toxins cause ecosystem disturbance and public health threats and constitute a growing concern in the frame of freshwater eutrophication and global warming. Microcystis has also been described as a producer of a multitude of bioactive natural products, some of interest for biotechnological and pharmaceutical application. 3−5 Cytotoxic aeruginoguanidines (AGDs) represent one of the most remarkable families of compounds described for Microcystis. 6 The three AGD congeners reported for strain Microcystis aeruginosa NIES-98 feature highly unprecedented characteristics such as a 1-(4-hydroxy-3-hydroxymethyl)-phenyl-1-hydroxy-2-propylamine-4′,3′,1-triO -sulfate (Hphpa trisulfate) moiety, along with geranylation and prenylation of arginines (Figure 1A). While bloom-forming Microcystis belong to the most intensively studied cyanobacteria, AGDs were reported only twice from a bloom in Czech Republic and an isolate in Brazil, 7,8 never from any other cyanobacteria. Their intricate features confine AGDs into a unique compound family. 3 Our recent genomic analysis of ten Microcystis strains revealed that the different genotypes share a highly similar core genome, while their biosynthetic gene clusters (BGCs) involved in natural product (NP) formation show a sporadic distribution. Moreover, we uncovered three cryptic BGCs not

Published
2019
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6. Marine Polysaccharide-Collagen Coatings on Ti6Al4V Alloy Formed by Self-Assembly

Author

Andrei Koptioug, Stéphane Cuenot, Roman A. Surmenev, Corinne Sinquin, Jemma G. Kerns, Sylvia Colliec-Jouault, Oksana I Mishukova, Timothy E.L. Douglas, Agata Zykwinska, Maria A. Surmeneva, Karl Norris, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies [IFREMER, Nantes], and Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)

Subjects
collagen, lcsh:Mechanical engineering and machinery, 02 engineering and technology, macromolecular substances, engineering.material, marine exopolysaccharide, Fibril, Polysaccharide, Maskinteknik, Article, 03 medical and health sciences, Coating, lcsh:TJ1-1570, Electrical and Electronic Engineering, Cell adhesion, ComputingMilieux_MISCELLANEOUS, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Chemistry, Mechanical Engineering, Ti6Al4V, Biomaterial, 021001 nanoscience & nanotechnology, Chemical engineering, Control and Systems Engineering, Self-healing hydrogels, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], engineering, Surface modification, Self-assembly, 0210 nano-technology, surface modification
Abstract

Polysaccharides of marine origin are gaining interest as biomaterial components. Bacteria derived from deep-sea hydrothermal vents can produce sulfated exopolysaccharides (EPS), which can influence cell behavior. The use of such polysaccharides as components of organic, collagen fibril-based coatings on biomaterial surfaces remains unexplored. In this study, collagen fibril coatings enriched with HE800 and GY785 EPS derivatives were deposited on titanium alloy (Ti6Al4V) scaffolds produced by rapid prototyping and subjected to physicochemical and cell biological characterization. Coatings were formed by a self-assembly process whereby polysaccharides were added to acidic collagen molecule solution, followed by neutralization to induced self-assembly of collagen fibrils. Fibril formation resulted in collagen hydrogel formation. Hydrogels formed directly on Ti6Al4V surfaces, and fibrils adsorbed onto the surface. Scanning electron microscopy (SEM) analysis of collagen fibril coatings revealed association of polysaccharides with fibrils. Cell biological characterization revealed good cell adhesion and growth on bare Ti6Al4V surfaces, as well as coatings of collagen fibrils only and collagen fibrils enhanced with HE800 and GY785 EPS derivatives. Hence, the use of both EPS derivatives as coating components is feasible. Further work should focus on cell differentiation.

Published
2019
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7. Investigation of interactions between the marine GY785 exopolysaccharide and transforming growth factor-β1 by atomic force microscopy

Author

Mélanie Marquis, Corinne Sinquin, Stéphane Cuenot, Agata Zykwinska, Laëtitia Marchand, Sylvia Colliec-Jouault, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Centre de Recherche Épidémiologie et Statistique Sorbonne Paris Cité (CRESS (U1153 / UMR_A_1125 / UMR_S_1153)), Institut National de la Recherche Agronomique (INRA)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris Descartes - Paris 5 (UPD5)-Université Sorbonne Paris Cité (USPC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), ANR, French National Research Agency [ANR-17-CE08-0001], Pays de la Loire region, and Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique)

Subjects
0301 basic medicine, Polymers and Plastics, 02 engineering and technology, Plasma protein binding, Nanoassemblies, Glycosaminoglycan, 03 medical and health sciences, chemistry.chemical_compound, Sulfation, [SDV.IDA]Life Sciences [q-bio]/Food engineering, Materials Chemistry, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, AFM imaging, Sulfate, ComputingMilieux_MISCELLANEOUS, Glycosaminoglycans, Sulfated polysaccharides, Atomic force microscopy, Organic Chemistry, Force spectroscopy, 021001 nanoscience & nanotechnology, 030104 developmental biology, chemistry, Single-molecule force spectroscopy, Biophysics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Macromolecule, Transforming growth factor
Abstract

International audience; Sulfated polysaccharides, such as glycosaminoglycans (GAG) regulate various biological activities through their interactions with growth factors. Investigating these interactions becomes the key to understand the structurefunction relationship of GAG. Highly sulfated derivatives prepared from the marine GY785 exopolysaccharide (EPS) produced by the deep-sea hydrothermal vent bacterium Alteromonas infernus have previously shown to stimulate the chondrogenic differentiation of mesenchymal stem cells in the presence of Transforming Growth Factor-beta 1 (TGF-beta 1). Here, the interactions between the GAG-mimetic GY785 EPS derivatives and TGF-beta 1 were investigated by Atomic Force Microscopy (AFM). The affinity between slightly sulfated or highly sulfated derivatives and TGF-beta 1 was explored by AFM imaging and single-molecule force spectroscopy experiments. The number of measured interactions and the interaction strength were both higher for highly sulfated derivative compared to the slightly sulfated one. These results clearly emphasize the involvement of sulfate groups in the protein binding and open new ways to tune cellular processes by designing macromolecules with adjustable sulfate charge density.

Published
2018
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8. Concentration and purification of Porphyridium cruentum exopolysaccharides by membrane filtration at various cross-flow velocities

Author

Marthe Gilbert, Corinne Sinquin, Benjamin Le Gouic, Anthony Massé, Nicolas Brodu, Sophie Le Gall, Romain Le Balc’h, Rafik Balti, Bioprocédés Appliqués aux Microalgues (GEPEA-BAM), Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Ifremer, French Regional Council of the 'Pays de la Loire', and Nantes University

Subjects
0106 biological sciences, 0301 basic medicine, Exopolysaccharides, Concentration, Bioengineering, Polysaccharide, Diafiltration, 01 natural sciences, Applied Microbiology and Biotechnology, Biochemistry, 03 medical and health sciences, [SPI]Engineering Sciences [physics], 010608 biotechnology, Monosaccharide, Dry matter, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, ComputingMilieux_MISCELLANEOUS, chemistry.chemical_classification, Chromatography, biology, Permeation, biology.organism_classification, 6. Clean water, 030104 developmental biology, Ceramic membrane, Membrane, chemistry, Porphyridium cruentum, Membrane filtration, Microalga
Abstract

International audience; Exopolysaccharides (EPS) from cell-free Porphyridiwn cruentum media were concentrated then purified (diafiltration) on a 0.14 ism ceramic membrane. The influence of cross-flow velocities on filtration performances was investigated. Mean permeate fluxes equal to 49.8, 68.9 and 81.9 L h(-1). m(-2) were obtained during the concentration at 4 bars for respectively cross-flow velocities inside the membrane lumen equal to 2.5, 3.3 and 4.2 m s(-1); 49.7 Lm(-1). M-2 for the diafiltration at 3.3 m s(-1). Permeate fluxes were correctly predicted from polysaccharide concentrations (10% deviation). Volume reduction factors higher than 7.8 were reached. Rejection rates of polysaccharides and proteins varied according to the cross-flow velocities. Thus, the EPS recovery rate or time of filtration could be modulated following the cross-flow velocity. Polysaccharides were concentrated 6.3 to 10.4 times in such a way that the final sugars concentration reached 1.74-2.26 g L-1. Rheological behavior of filtered solutions changed following the concentration progress. More than 80% (w/w) of polysaccharides were recovered while 49% and 99% of proteins and salts were removed respectively. The filtrations allowed reaching a final monosaccharide content of dry matter equal to 48.9% against 0.6% (w/w) initially.

Published
2018
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9. A multiscale study of mercury transformations and dynamics at the chemocline of the Petit-Saut tropical reservoir (French Guiana)

Author

Didier Jézéquel, Daniel Cossa, Edouard Metzger, Bogdan Muresan, Laboratoire de Planétologie et Géodynamique - Angers (LPG-ANGERS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Centre d'Enseignement et de Recherche Eau Ville Environnement (CEREVE), AgroParisTech-École des Ponts ParisTech (ENPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire de Planétologie et Géodynamique - Bio-Indicateurs Actuels et Fossiles (LPG-BIAF), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS)

Subjects
Biogeochemical cycle, Environmental Engineering, 010504 meteorology & atmospheric sciences, chemistry.chemical_element, 010501 environmental sciences, Chemocline, 01 natural sciences, Pollution, Redox, Mercury (element), Nutrient, Water column, chemistry, Environmental chemistry, Epilimnion, Dissolved organic carbon, [SDE]Environmental Sciences, Environmental Chemistry, Waste Management and Disposal, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

This study investigated, on both metric and centimetric scales, mercury (Hg) transformations and dynamics within a water column chemocline of a tropical reservoir. Data collected included conventional measurement of Hg in water samples, diffusive gradients in thin-films (DGT) assessments, and thermodynamic speciation modeling in order to portray the biogeochemical processes that control elemental Hg (EM) and dissolved monomethylated Hg (MeHgD) production. The primary contribution of this study is demonstration that the DGT technique can be successfully implemented to examine labile Hg compound mobilization, and estimation of how local substratum facilitates Hg reduction and methylation reactions. DGT profiles with a resolution of 1 cm revealed a fine sequence of prominent Hg reduction/oxidation reactions at the chemocline level. This is interpreted as a manifestation of both: i) kinetic effects capable of arising inside the diffusive layer of DGT devices, and ii) extremely localized production or consumption of reducible and methylable Hg. Another key result obtained at the metric scale is that EM and MeHgD production at a water column chemocline are intricately linked, as both are fueled by nutrients episodically released during the decomposition of falling epilimnetic organic particles or inhibited by dissolved organic matter and inorganic compounds continuously transported from the deeper monimolimnion. Finally, it is worth noting that the chemocline acts as an accumulation and recycling domain for falling MeHg-loaded organic particles, whereas the high primary productivity layer in the epilimnion represents the principal reactor with respect to Hg methylation and reduction.

Published
2018
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10. Full-scale validation of an algal productivity model including nitrogen limitation

Author

Olivier Bernard, Quentin Béchet, Noémie Coulombier, Thomas Lasserre, Christophe Vasseur, Loic Le Dean, Université Côte d'Azur (UCA), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), La Compagnie du Vent, Université de Nantes (UN)-Université de Nantes (UN), Biological control of artificial ecosystems (BIOCORE), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de la Recherche Agronomique (INRA)-Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'océanographie de Villefranche (LOV), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Gouzé, Jean-Luc, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire d'océanographie de Villefranche (LOV), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
0106 biological sciences, 0301 basic medicine, Full scale, Photobioreactor, Biomass, chemistry.chemical_element, 01 natural sciences, 7. Clean energy, 03 medical and health sciences, 010608 biotechnology, [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, Raceway, Productivity model, Quota model, 2. Zero hunger, Environmental engineering, Modeling, Nitrogen, Carotenoids, Raceway ponds, Outdoor cultivation, 030104 developmental biology, chemistry, Productivity (ecology), 13. Climate action, Biofuel, Biofuels, Environmental science, Dunaliella salina, [INFO.INFO-AU] Computer Science [cs]/Automatic Control Engineering, Agronomy and Crop Science
Abstract

International audience; Accurate predictions of algal productivity under nutrient-limiting conditions are needed to assess the economics of full-scale algal cultivation for the developing markets of food, feed, and at longer term, green chemistry and biofuel. In particular, predicting pigments production from micro-algae is a critical milestone in the assessments of high-value chemicals production from micro-algae. This study validates a mathematical model predicting algal biomass productivity in outdoor raceway ponds under nitrogen-limiting conditions. The model was first validated from experimental data collected during Dunaliella salina cultivation in indoor photobioreactors and accounts for the impact of light, temperature, and nitrogen concentration on algal productivity (overall accuracy on algal concentration of ±2.7 mg L−1, N = 48). The model was then validated against data collected in outdoor raceway ponds over a period of 2 years, representing a total of 111 days of cultivation. Biomass and extracellular nitrogen concentrations predictions were accurate within ±0.055 g L−1 (N = 69) and ±0.0024 g L−1 (N = 26), respectively. Model inaccuracies were mostly due to measurement errors and uncertainties on model inputs. Measured carotenoids concentrations were found proportional to the biomass concentrations in the outdoor raceway ponds. By coupling this linear correlation to the productivity model, predicted carotenoids concentrations were in good agreement with experimental data (accuracy within ±0.0046 g L−1, N = 55). The mathematical model developed in this study has therefore the potential to refine previous assessments of algal cultivation for biofuels and pigments production.

Published
2018
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11. Modeling the influence of eutrophication and redox conditions on mercury cycling at the sediment-water interface in the Berre Lagoon

Author

Joël Knoery, Elizaveta Protsenko, Raoul-Marie Couture, Alice Newton, Olivier Radakovitch, Dominika Krzeminska, Svetlana Pakhomova, Daniel Cossa, Evgeniy Yakushev, Shamil Yakubov, Sylvain Rigaud, Norwegian Institute for Air Research (NILU), Norwegian University of Science and Technology [Trondheim] (NTNU), P.P. Shirshov Institute of Oceanology (SIO), Russian Academy of Sciences [Moscow] (RAS), Norwegian Institute for Water Research (NIVA), Détection, évaluation, gestion des risques CHROniques et éMErgents (CHROME) / Université de Nîmes (CHROME), Université de Nîmes (UNIMES), Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Département de Chimie, Université Laval, Université Laval, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Helmholtz-Zentrum Geesthacht (GKSS), Norwegian Institute of Bioeconomy Research (NIBIO), Centro de Investigação Marinha e Ambiental (CIMA), Universidade do Algarve (UAlg), Norwegian University of Science and Technology (NTNU), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université Laval [Québec] (ULaval), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), PSE-ENV/SRTE/LRTA, Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (IRSN/PSE-ENV/SRTE/LRTA), Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), and Norsk institutt for bioøkonomi=Norwegian Institute of Bioeconomy Research (NIBIO)

Subjects
mercury, lcsh:QH1-199.5, 010504 meteorology & atmospheric sciences, biogeochemical modeling, BROM, chemistry.chemical_element, Ocean Engineering, lcsh:General. Including nature conservation, geographical distribution, 010501 environmental sciences, Aquatic Science, Oceanography, 01 natural sciences, VDP::Matematikk og Naturvitenskap: 400::Kjemi: 440::Miljøkjemi, naturmiljøkjemi: 446, Bottom water, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Water column, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Sediment–water interface, 14. Life underwater, lcsh:Science, 0105 earth and related environmental sciences, Water Science and Technology, Global and Planetary Change, anoxia, Sediment, methylmercury, Eutrophication, Anoxic waters, 6. Clean water, lagoon, Mercury (element), eutrophication, chemistry, 13. Climate action, Bioaccumulation, Environmental chemistry, Mercury Cycling, Environmental science, lcsh:Q, Sediment-Water Interface, Berre Lagoon
Abstract

This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(O)), divalent mercury (Hg(II)) and methylmercury (MeHg). The behavior of mercury species in the model is interconnected with changes of oxygen, hydrogen sulfide, iron oxides, organic matter, and biota. We simulated the transformation and transport of Hg species in the water column and upper sediment layer under five different scenarios, combining various levels of oxygenation and trophic state in the Berre lagoon, a shallow eutrophic lagoon of the French Mediterranean coast subjected to seasonal anoxia. The first scenario represents the conditions in the lagoon that are compared with experimental data. The four other scenarios were produced by varying the biological productivity, using low and high nutrient (N and P) concentrations, and by varying the redox conditions using different intensity of vertical mixing in the water column. The results of the simulation show that both oxidized and reduced sediments can accumulate Hg, but any shifts in redox conditions in bottom water and upper sediment layer lead to the release of Hg species into the water column. Eutrophication and/or restricted vertical mixing lead to reducing conditions and intensify MeHg formation in the sediment with periodic release to the water column. Oxygenation of an anoxic water body can lead to the appearance of Hg species in the water column and uptake by organisms, whereby Hg may enter into the food web. The comparison of studied scenarios shows that a well-oxygenated eutrophic system favors the conditions for Hg species bioaccumulation with a potential adverse effect on the ecosystem. The research is relevant to the UN Minimata convention, EU policies on water, environmental quality standards and Mercury in particular. VISTA - a basic research program Norwegian Academy of Science and Letters 6164 Statoil 6164 project PREDHYPO A*MIDEX project - Investissements d'Avenir French Government program ANR-11-IDEX-0001-02 Norwegian Research Council SKATTEfunn project Aquatic Modeling Tools 272749 NILU CIMA IMBER Future Earth Coasts Future Earth Ocean KAN info:eu-repo/semantics/publishedVersion

Published
2018
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12. Low-Molecular-Weight Fucoidan Induces Endothelial Cell Migration via the PI3K/AKT Pathway and Modulates the Transcription of Genes Involved in Angiogenesis

Author

Sophie Gandrille, Isabelle Galy-Fauroux, Wassila Carpentier, Sylvia Colliec-Jouault, Anna Lokajczyk, Claire Bouvard, Anne-Marie Fischer, Dominique Helley, Françoise Grelac, Thrombose : Épidémiologie, Physiopathologie et Thérapeutiques Innovantes (UMR_S 765), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Université Paris Diderot - Paris 7 (UPD7), Université Paris Descartes - Paris 5 (UPD5), Paris-Centre de Recherche Cardiovasculaire (PARCC - UMR-S U970), Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Plateforme Post-génomique de la Pitié-Salpêtrière (P3S), UMS omique (OMIQUE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), Innovations thérapeutiques en hémostase (IThEM - U1140), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), French Ministry of Research and Education, French Society of Hematology, Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hôpital Européen Georges Pompidou [APHP] (HEGP), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpitaux Universitaires Paris Ouest - Hôpitaux Universitaires Île de France Ouest (HUPO), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Thrombose : Épidémiologie, Physiopathologie et Thérapeutiques Innovantes ( UMR_S 765 ), Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Université Paris Diderot - Paris 7 ( UPD7 ), Université Paris Descartes - Paris 5 ( UPD5 ), Paris-Centre de Recherche Cardiovasculaire ( PARCC - U970 ), Hôpital Européen Georges Pompidou [APHP] ( HEGP ) -Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Plateforme Post-génomique de la Pitié-Salpêtrière ( P3S ), UMS omique ( OMIQUE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Innovations thérapeutiques en hémostase ( IThEM - U1140 ), Hôpital Européen Georges Pompidou [APHP] ( HEGP ), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes ( IFREMER Nantes ), Université de Nantes ( UN ), and HAL-UPMC, Gestionnaire

Subjects
Vascular Endothelial Growth Factor A, Cell signaling, fucoidan, angiogenesis, vasculogenesis, migration, signaling, transcriptomics, Cytoskeleton organization, Angiogenesis, Neovascularization, Physiologic, Pharmaceutical Science, Biology, Article, chemistry.chemical_compound, Vasculogenesis, Cell Movement, Polysaccharides, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Drug Discovery, Human Umbilical Vein Endothelial Cells, Humans, lcsh:QH301-705.5, Pharmacology, Toxicology and Pharmaceutics (miscellaneous), Cytoskeleton, PI3K/AKT/mTOR pathway, Cell migration, Cell biology, Molecular Weight, Endothelial stem cell, Vascular endothelial growth factor, Gene Expression Regulation, lcsh:Biology (General), chemistry, [ SDV.BBM.GTP ] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Phosphatidylinositol 3-Kinase, Proto-Oncogene Proteins c-akt
Abstract

International audience; Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF's mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair.

Published
2015
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13. Effect of vacuum and modified atmosphere packaging on the microbiological, chemical and sensory properties of tropical red drum (Sciaenops ocellatus) fillets stored at 4°C

Author

Christine Chopin, Adèle Silbande, Katia Rochefort, Sandra Adenet, Françoise Leroi, Juliette Smith-Ravin, Josiane Cornet, Département Scientifique Interfacultaire (DSI), Université des Antilles (Pôle Martinique), Université des Antilles (UA)-Université des Antilles (UA), Pôle Agroalimentaire Régional de la Martinique (PARM), Ifremer Nantes, STBM, Nantes, France, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), and Laboratoire Ecosystèmes Microbiens et Molécules Marines pour les Biotechnologies (EM 3 B)

Subjects
Biogenic Amines, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Vacuum, Nitrogen, Organoleptic, Food spoilage, VP, Colony Count, Microbial, Trimethylamine, [SDV.CAN]Life Sciences [q-bio]/Cancer, [SDV.BC.BC]Life Sciences [q-bio]/Cellular Biology/Subcellular Processes [q-bio.SC], Chryseobacterium, Carnobacterium, Microbiology, chemistry.chemical_compound, 0404 agricultural biotechnology, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], [SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB], Animals, 14. Life underwater, Food science, ComputingMilieux_MISCELLANEOUS, Cadaverine, biology, Bacteria, Microbiota, Fishes, Food Packaging, [SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology, 04 agricultural and veterinary sciences, General Medicine, biology.organism_classification, Biogenic amine, 040401 food science, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], Kocuria, [SDV.GEN.GH]Life Sciences [q-bio]/Genetics/Human genetics, chemistry, Seafood, Modified atmosphere, NGS, MAP, Food Microbiology, 16S rRNA gene, Metagenomics, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Food Science
Abstract

Aims The effect of vacuum (VP – 4 °C) and CO2/N2–atmosphere (MAP – 4 °C) packaging on the quality of red drum fillets compared with whole gutted iced fish was investigated. Methods and results A metagenomic approach, bacterial enumeration and isolation, biochemical and sensory analyses were carried out. The organoleptic rejection of whole fish was observed at day 15 whereas VP and MAP fillets appeared unacceptable only after 29 days. At these dates, total mesophilic counts reached 107–108 CFU g− 1. According to Illumina MiSeq sequencing, Arthrobacter, Chryseobacterium, Brevibacterium, Staphylococcus and Kocuria were the main genera of the fresh red drum fillets. At the sensory rejection time, lactic acid bacteria (LAB), particularly Carnobacterium sp., dominated the microbiota of both types of packaging. The pH value of fresh samples was between 5.96 and 6.37 and did not vary greatly in all trials. Total volatile basic nitrogen (TVBN) and trimethylamine (TMA) concentrations were low and not represent reliable indicators of the spoilage, contrary to some biogenic amines (cadaverine, putrescine and tyramine). Conclusion Chilled packed fillets of red drum have an extended shelf-life compared to whole gutted iced fish. Overall, few differences in sensory and microbial quality were observed between the VP and MAP samples. Significance and impact of the study Next-Generation Sequencing (NGS) provided data on the microbiota of a tropical fish.

Published
2017
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14. Betaine lipid and neutral lipid production under nitrogen or phosphorus limitation in the marine microalga Tisochrysis lutea (Haptophyta)

Author

Gaël Bougaran, Justine Marchand, Annick Morant-Manceau, Bing Huang, Gregory Carrier, Stanislas Thiriet-Rupert, Virginie Mimouni, Bruno Saint-Jean, Ewa Lukomska, Brigitte Moreau, Mer, molécules et santé EA 2160 (MMS), Le Mans Université (UM)-Université de Nantes - UFR des Sciences Pharmaceutiques et Biologiques, Université de Nantes (UN)-Université de Nantes (UN), Amélioration génétique et adaptation des plantes méditerranéennes et tropicales (UMR AGAP), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro), Physiologie et biotechnologie des Algues (PBA), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de l’Élevage, Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Le Mans Université (UM)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Université de Nantes - UFR des Sciences Pharmaceutiques et Biologiques, Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), and Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique)

Subjects
0106 biological sciences, 0301 basic medicine, Betaine lipid, Nitrogen, [SDV]Life Sciences [q-bio], Phospholipid, Photosynthesis, 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Betaine, Lipid remodeling, Tisochrysis lutea, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, ComputingMilieux_MISCELLANEOUS, Chemistry, Carbon fixation, Phosphorus, Photosynthetic capacity, Chloroplast, Polyunsaturated fatty acid, 030104 developmental biology, Membrane, Biochemistry, Thylakoid, lipids (amino acids, peptides, and proteins), Agronomy and Crop Science, 010606 plant biology & botany
Abstract

Nitrogen (N) and phosphorus (P) limitations induce neutral lipid accumulation and membrane lipid remodeling in the domesticated oleaginous microalga Tisochrysis lutea. This study compared growth, photosynthetic activity, biochemical and transcriptional responses of T. lutea throughout batch cultures under N or P limitation compared with non-limiting nutrient condition (NP). The results show that, under N limitation, the breakdown and re-use of cellular N-containing compounds contributed to carbohydrates and further triacylglycerol (TAG) accumulation, where the accumulation of docosahexaenoic acid (DHA) in neutral lipids might mainly be derived from the recycling of membrane polar lipids. Conversely, P limitation did not hinder the photosynthetic capacity; a higher efficiency of carbon fixation fueled the allocation of carbon fluxes to the reserves of carbohydrates and neutral lipids. These latter accumulated without massive degradation of essential cellular compounds. Betaine lipids constitute the major compounds of non-plastidial membranes in T. lutea. Given an extremely low constitutive phospholipid level, phospholipids might not be involved in the regulation of P storage. However, transfer of P from non-plastidial to chloroplast membranes might occur, keeping a stable lipid composition of thylakoid membranes and maintaining a relatively high photosynthetic capacity under P deprivation.

Published
2019
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15. Assembly of HE800 exopolysaccharide produced by a deep-sea hydrothermal bacterium into microgels for protein delivery applications

Author

Corinne Sinquin, Sylvia Colliec-Jouault, Mélanie Marquis, Stéphane Cuenot, Agata Zykwinska, Institut des Matériaux Jean Rouxel (IMN), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), EU Interreg IVA 2 Seas 'Bio-Care Marine', Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), and Université de Nantes (UN)

Subjects
0301 basic medicine, business.product_category, Polymers and Plastics, Microfluidics, Nanotechnology, 02 engineering and technology, Polysaccharide, Hydrothermal circulation, Divalent, 03 medical and health sciences, Marine exopolysaccharide, Microfiber, Materials Chemistry, Animals, Microparticle, Bovine serum albumin, Microencapsulation, Protein release, ComputingMilieux_MISCELLANEOUS, Glycosaminoglycans, Vibrio, chemistry.chemical_classification, Drug Carriers, biology, Chemistry, Organic Chemistry, Polysaccharides, Bacterial, Microcarrier, Polychaeta, Serum Albumin, Bovine, Microfluidic Analytical Techniques, 021001 nanoscience & nanotechnology, 030104 developmental biology, Microfluidic, Microfibers, biology.protein, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Cattle, Microgel particles, 0210 nano-technology, business, Gels
Abstract

International audience; Assembly of biopolymers into microgels is an elegant strategy for bioencapsulation with various potential biomedical applications. Such biocompatible and biodegradable microassemblies are developed not only to protect the encapsulated molecule but also to ensure its sustained local delivery. The present study describes the fabrication of microassemblies from a marine HE800 exopolysaccharide (EPS), which displays a glycosaminoglycan (GAG)-like structure and biological properties. HE800 EPS was assembled, through physical cross-linking with divalent ions, into microgel particles and microfibers using microfluidics. The microparticle morphology was highly affected by the polysaccharide concentration and its molecular weight. A model protein, namely Bovine Serum Albumin (BSA) was subsequently encapsulated within HE800 microparticles in one-step process using microfluidics. The protein release was tuned by the microparticle morphology with a lower protein amount released from the most homogeneous structures. Our findings demonstrate the high potential of HE800 EPS based microassemblies as innovative protein microcarriers for further biomedical applications.

Published
2016
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16. The fate of river organic carbon in coastal areas: A study in the Rhône River delta using multiple isotopic (δ 13 C, Δ 14 C) and organic tracers

Author

Ming-Yi Sun, Claire Treignier, Nadine Tisnérat-Laborde, K. Loftis, Tommaso Tesi, S. Azoury, Bruno Lansard, Roselyne Buscail, Jacek Tronczynski, Philippe Kerhervé, L. Pastor, Christophe Rabouille, Cecile Cathalot, Flora Toussaint, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Océan et Interfaces (OCEANIS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Géochrononologie Traceurs Archéométrie (GEOTRAC), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Georgia [USA], Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de géochimie des Eaux (LGE), Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris), Department of Applied Environmental Science [Stockholm] (ITM), Stockholm University, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris, Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), and Université de Nantes (UN)

Subjects
0106 biological sciences, Delta, 010504 meteorology & atmospheric sciences, [SDE.MCG]Environmental Sciences/Global Changes, Fraction (chemistry), 01 natural sciences, Physics::Geophysics, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Geochemistry and Petrology, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, Organic matter, 14. Life underwater, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Carbon flux, chemistry.chemical_classification, Total organic carbon, geography, River delta, geography.geographical_feature_category, [CHIM.ORGA]Chemical Sciences/Organic chemistry, 010604 marine biology & hydrobiology, [SDE.ES]Environmental Sciences/Environmental and Society, Oceanography, chemistry, 13. Climate action, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, [SDU.STU.ST]Sciences of the Universe [physics]/Earth Sciences/Stratigraphy, [SHS.ENVIR]Humanities and Social Sciences/Environmental studies, Geology
Abstract

A significant fraction of the global carbon flux to the ocean occurs in River-dominated Ocean Margins (RiOMar) although large uncertainties remain in the cycle of organic matter (OM) in these systems. In particular, the OM sources and residence time have not been well clarified. Surface (0-1 cm) and sub-surface (3-4 cm) sediments and water column particles (bottom and intermediate depth) from the Rhone River delta system were collected in June 2005 and in April 2007 for a multi-proxy study. Lignin phenols, black carbon (BC), proto-kerogen/BC mixture, polycyclic aromatic hydrocarbons (PAHs), carbon stable isotope (delta C-13(OC)), and radiocarbon measurements (delta C-14(OC)) were carried out to characterize the source of sedimentary organic material and to address degradation and transport processes. The bulk OM in the prodelta sediment appears to have a predominantly modern terrigenous origin with a significant contribution of modern vascular C-3 plant detritus (Delta C-14(OC) = 27.9 parts per thousand, delta C-13(OC) = -27.4 parts per thousand). In contrast, the adjacent continental shelf, below the river plume, seems to be dominated by aged OM (Delta C-14(OC) = -400 parts per thousand, delta C-13(OC) = -24.2 parts per thousand), and shows no evidence of dilution and/or replacement by freshly produced marine carbon. Our data suggest an important contribution of black carbon (50% of OC) in the continental shelf sediments. Selective degradation processes occur along the main dispersal sediment system, promoting the loss of a modern terrestrial OM but also proto-kerogen-like OM. In addition, we hypothesize that during the transport across the shelf, a long term resuspension/deposition loop induces efficient long term degradation processes able to rework such refractory-like material until the OC is protected by the mineral matrix of particles.

Published
2013
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17. Occurrence of priority and emerging organic compounds in fishes from the Rhone River (France)

Author

A. Peretti, Pierre Labadie, B. Le Bizec, Katrin Vorkamp, Cecile Miege, Jacek Tronczynski, Marc Babut, Hélène Budzinski, Marina Coquery, Henri Persat, Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Structure et fonctionnement des systèmes hydriques continentaux (SISYPHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE)-MINES ParisTech - École nationale supérieure des mines de Paris-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'étude des Résidus et Contaminants dans les Aliments (LABERCA), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS), Aarhus University [Aarhus], Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Laboratoire d'Ecologie des Hydrosystèmes Fluviaux (EHF), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université Pierre et Marie Curie - Paris 6 (UPMC)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), and Institut National de la Recherche Agronomique (INRA)-École nationale vétérinaire, agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)

Subjects
PRIORITY COMPOUNDS, SUBSTANCE PRIORITAIRE, 0211 other engineering and technologies, 02 engineering and technology, POLLUTION DE L'EAU, 010501 environmental sciences, 01 natural sciences, Biochemistry, Analytical Chemistry, chemistry.chemical_compound, Priority compounds, SUBSTANCE EMERGENTE, Emerging compounds, 14. Life underwater, 0105 earth and related environmental sciences, RIVER WATERS, 021110 strategic, defence & security studies, Barbel, EMERGING COMPOUNDS, biology, Squalius, Common bream, Blicca bjoerkna, Fishes, Hexachlorobenzene, biology.organism_classification, Barbus barbus, Contamination level, 6. Clean water, Hexachlorobutadiene, CONTAMINATION, CONTAMINATION LEVEL, chemistry, 13. Climate action, River waters, Environmental chemistry, [SDE]Environmental Sciences, Freshwater fish, FISHES, POISSON, IMPACT SUR L'ENVIRONNEMENT
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA; The main objective of this study was to collect new data on the occurrence and levels of priority and emerging organic compounds in freshwater fishes sampled in the Rhone River. The 34 studied contaminants included alkylphenols (AP), bisphenol A (BPA), polybromodiphenylethers (PBDE), perfluorinated compounds (PFC), hexabromocyclododecanes (HBCD), hexachloro-benzene (HCB) and hexachloro-butadiene (HCBD). About 50 fish samples (individual specimens or pooled fishes) were collected from 3 sites located upstream and downstream of the Lyon metropolitan area in the Rhone River (France). Four species were caught at each site, namely: the barbel (Barbus barbus), the common bream (Abramis brama), the white bream (Blicca bjoerkna) and the chub (Squalius cephalus). Some contaminants were quantified in all the 32 fish samples analysed: 4-nonylphenol, Α-HBCD, the 6 PBDE congeners (28, 47, 99, 100, 153, 154), perfluorooctanesulfonate (PFOS) and perfluorodecanoic acid. And 23 of the 32 samples had concentration of PFOS above the Environmental Quality Standards (up to 6 times higher the EQS); and all the 32 samples had concentrations of PBDE above the EQS (up to 4000 times higher, with the sum of 6 PBDE varying from 4.5 to 182 ng/g dw). Clearly, the interest to consider PFOS and HBCD as new priority substances is confirmed. In contrast, the pertinence of a priority status for HCBD, which was never quantified in our study, might have to be reconsidered in the future.

Published
2012
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18. Methylmercury in tailings ponds of Amazonian gold mines (French Guiana): Field observations and an experimental flocculation method for in situ remediation

Author

Stéphane Guédron, Daniel Cossa, Michel Grimaldi, Laurent Charlet, Géochimie, Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Supported mainly by the CNRS as a part of the Mercury in French Guiana research program and by the Boulanger Mine Company (CMB)., Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), and Université de Nantes (UN)

Subjects
010504 meteorology & atmospheric sciences, 010501 environmental sciences, engineering.material, 01 natural sciences, Water column, Decantation, Geochemistry and Petrology, parasitic diseases, Environmental Chemistry, Organic matter, Turbidity, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology, 0105 earth and related environmental sciences, Lime, chemistry.chemical_classification, Hydrology, fungi, 15. Life on land, Pollution, Tailings, Anoxic waters, 6. Clean water, Soil structure, chemistry, engineering, Geology
Abstract

Sites of monomethylmercury (MMHg) production in Amazonian regions have been identified in hydraulic reservoirs, lake sediments and wetlands, but tailings ponds have not yet received sufficient attention for this purpose. This work evidenced high MMHg production within the water column and the interstitial water of two tailings ponds of French Guiana Au mines located; (i) in a small scale exploitation (Combat) where Hg was used for Au amalgamation, and (ii) in an industrial on-going Au mine (Yaoni) processing without Hg. The (MMHg)(D) maximum (2.5 ng L-1) occurred in the oxic water column above the sediment-water interface (SWI) of the most recent tailings pond (Combat), where the substrate was fresh, the redox transition was sharp and the pool of total Hg was large. In the Yaoni pond, the (MMHg)(D) maximum concentration (1.4 ng L-1) was located at the SWI where suboxic conditions prevailed. Using the (MMHg)(D) concentration as a proxy for Hg methylation rates, the present results show that Hg methylation may occur in various redox conditions in tailings ponds, and are favored in areas where the organic matter regeneration is more active. A 3-month long laboratory experiment was performed in oxic and anoxic boxes filled with high turbidity waters from the Combat Au mine to simulate tailings ponds. Slaked lime was added in an experimental set (2 mg L-1)and appeared to be very efficient for the reduction of suspended particulate matter (SPM) to environmentally acceptable concentrations. However, at the end of the experiment, large (MMHg)(D) concentrations were monitored under treated anoxic conditions with the (MMHg)(D) maximum located at the SWI above the Fe-reducing zones. No (MMHg)(D) was detected in oxic experiments. The use of slaked lime for SPM decantation appears to be an efficient and non-onerous process for Au miners to avoid Hg methylation in tailings ponds when it is combined with rapid drainage of the mine waters. A subsequent human intervention is however necessary for the recovery of soil structure through the cover of dried ponds with organic rich materials and reforestation to avoid the stagnation of rain waters and the occurrence of anoxia. (C) 2010 Elsevier Ltd. All rights reserved.

Published
2011
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19. Aromas potentiality of tuna cooking juice concentrated by nanofiltration

Author

Pascal Jaouen, Mireille Cardinal, Anthony Massé, Patrick Bourseau, Josiane Cornet, Carole Prost, Raja Ben Amar, Khaled Walha, Univ Sfax, Fac Sci Sfax, Lab Sci Mat & Environm, Sfax 3018, Tunisia., Université de Sfax - University of Sfax, Laboratoire de génie des procédés - environnement - agroalimentaire (GEPEA), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Ecole Polytechnique de l'Université de Nantes (EPUN), Université de Nantes (UN)-Université de Nantes (UN)-Institut Universitaire de Technologie - Nantes (IUT Nantes), Université de Nantes (UN)-Institut Universitaire de Technologie Saint-Nazaire (IUT Saint-Nazaire), Université de Nantes (UN)-Institut Universitaire de Technologie - La Roche-sur-Yon (IUT La Roche-sur-Yon), Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Université Bretagne Loire (UBL), Laboratoire d'Ingénierie des Matériaux de Bretagne (LIMATB), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université de Brest (UBO), Ifremer Nantes, STBM, Nantes, France, Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Food Quality Aroma, École nationale d'ingénieurs des techniques des industries agricoles et alimentaires (ENITIAA), Mines Nantes (Mines Nantes)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Microfiltration, Membrane separation, 02 engineering and technology, Aromas concentration, Membrane technology, 0404 agricultural biotechnology, 020401 chemical engineering, Organic matter, 14. Life underwater, Food science, 0204 chemical engineering, Effluent, Aroma, chemistry.chemical_classification, biology, food and beverages, 04 agricultural and veterinary sciences, Permeation, Sensory analysis, biology.organism_classification, 040401 food science, Nanofiltration, chemistry, 13. Climate action, Tuna cooking juice, Tuna, Food Science
Abstract

International audience; Tuna cooking juices contain high organic load preventing the rejection in the environment without treatment. But the effluents present an interesting fishy odour and it is worth recovering aroma compounds. In this work, two industrial tuna cooking juices were concentrated by nanofiltration. Nanofiltration performance was discussed in terms of permeation fluxes, organic matter retention and impact on the aromatic properties of juices. NF sharply decreases the global intensity of juices and modifies their aromatic equilibrium. However, the main characteristics and the marine nature of juices were kept. A pre-treatment by microfiltration (MF) induces a marked increase in permeation fluxes during NF concentration while it slightly affects the aromatic properties of juice. (C) 2010 Elsevier Ltd. All rights reserved.

Published
2011
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20. Amazonian former gold mined soils as a source of methylmercury: Evidence from a small scale watershed in French Guiana

Author

Stéphane Guédron, Delphine Tisserand, Daniel Cossa, Catherine Grimaldi, Michel Grimaldi, Laurent Charlet, Géochimie, Institut des Sciences de la Terre (ISTerre), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Biogéochimie et écologie des milieux continentaux (Bioemco), Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Sol Agro et hydrosystème Spatialisation (SAS), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), This research was supported mainly by the CNRS, FNS, FEDER, MATE/DIREN, and ANR as a part of the Mercury in French Guiana research program and by the Boulanger Mine Company (CMB)., Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS)

Subjects
Biogeochemical cycle, Environmental Engineering, Watershed, 010504 meteorology & atmospheric sciences, Rain, chemistry.chemical_element, Hydromorphic soils, 010501 environmental sciences, 01 natural sciences, Mining, Sink (geography), Stream water, Rivers, Soil Pollutants, Gold placers, Tropical watershed, [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, Oxisols, Waste Management and Disposal, 0105 earth and related environmental sciences, Water Science and Technology, Civil and Structural Engineering, Hydrology, geography, geography.geographical_feature_category, Ecological Modeling, Methylmercury, Mercury, Methylmercury Compounds, 15. Life on land, Particulates, Throughfall, Pollution, 6. Clean water, French Guiana, Mercury (element), Wilderness, chemistry, 13. Climate action, Oxisol, Soil water, Environmental science, Gold, Seasons, Water Pollutants, Chemical, Environmental Monitoring
Abstract

Agrohydrologie; International audience; Total mercury (HgT) and monomethylmercury (MMHg) were investigated in a tropical head watershed (1 km2) of French Guiana. The watershed includes a pristine area on the hill slopes and a former gold mined flat in the bottomland. Concentrations of dissolved and particulate HgT and MMHg were measured in rain, throughfall, soil water and at three points along the stream. Samples were taken in-between and during 14 storm events at the beginning and middle of the 2005 and 2006 rainy seasons. Dissolved and particulate HgT concentrations in the stream slightly increased downstream, while dissolved and particulate MMHg concentrations were low at the pristine sub-watershed outlet (median = 0.006 ng L−1 and 1.84 ng g−1, respectively) and sharply increased at the gold mined flat outlet (median = 0.056 ng L−1 and 6.80 ng g−1, respectively). Oxisols, which are dominant in the pristine area act as a sink of HgT and MMHg from rain and throughfall inputs. Hydromorphic soils in the flat are strongly contaminated with Hg (including Hg0 droplets) and their structure has been disturbed by former gold-mining processes, leading to multiple stagnant water areas where biogeochemical conditions are favorable for methylation. In the former gold mined flat high dissolved MMHg concentrations (up to 0.8 ng L−1) were measured in puddles or suboxic soil pore waters, whereas high dissolved HgT concentrations were found in lower Eh conditions. Iron-reducing bacteria were suggested as the main methylators since highest concentrations for dissolved MMHg were associated with high dissolved ferrous iron concentrations. The connection between saturated areas and stagnant waters with the hydrographic network during rain events leads to the export of dissolved MMHg and HgT in stream waters, especially at the beginning of the rainy season. As both legal and illegal gold-mining continues to expand in French Guiana, an increase in dissolved and particulate MMHg emissions in the hydrographic network is expected. This will enhance MMHg bio-amplification and present a threat to local populations, whose diet relies mainly on fish.

Published
2011
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21. Synergic effect of gold mining and damming on mercury contamination in fish

Author

Gilles Durrieu, Marina Coquery, Régine Maury-Brachet, Alain Boudou, Daniel Cossa, UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Milieux aquatiques, écologie et pollutions (UR MALY), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire de Mathématiques de Bretagne Atlantique (LMBA), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Université de Bordeaux (UB), Qualité des eaux et prévention des pollutions (UR QELY), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), Irstea Publications, Migration, Durrieu, Gilles, Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), and Université de Nantes (UN)

Subjects
[SDE] Environmental Sciences, Gold mining, 010504 meteorology & atmospheric sciences, CEMAGREF, chemistry.chemical_element, Food Contamination, 010501 environmental sciences, 01 natural sciences, Mining, Fish diet, Rivers, [STAT.AP] Statistics [stat]/Applications [stat.AP], GUYANE FRANCAISE, Environmental Chemistry, Hydroelectric reservoir, Animals, MIC, Mercury contamination, QELY, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [STAT.AP]Statistics [stat]/Applications [stat.AP], business.industry, Environmental engineering, Fishes, General Chemistry, Mercury, Particulates, Contamination, 6. Clean water, Mercury (element), chemistry, 13. Climate action, Environmental chemistry, Soil water, [SDE]Environmental Sciences, Environmental science, France, Gold, business, Water Pollutants, Chemical, Environmental Monitoring, CHI
Abstract

International audience; Since the late 1980s, several studies have shown that human populations in the Amazon basin are exposed to high mercury levels in their fish diet. Gold mining, which releases the metal during the amalgamation process and erodes soils naturally rich in mercury, is regarded as the main contamination source. Here, we present the results of a comparative study of mercury distribution in the water and fish of two adjacent rivers in French Guiana, with and without gold mining activities. As a consequence of a marked difference in suspended particulate matter between the two systems, total mercury concentrations in unfiltered water samples were higher in the mined river (25.4-34.9 ng L-1) as compared to the reference one (2.1- 5.4 ng L-1). Surprisingly, no significant differences were observed in mercury concentrations between 13 common fish species at upstream sites. In sharp contrast, mercury concentration of fish caught downstream a hydroelectric reservoir, where the two rivers flow, was up to 8-fold higher than that upstream. Mercury speciation measurements allowed one to relate these differences in fish to the water distribution of monomethylmercury, the mercury chemical species that biomagnifies along aquatic foodwebs. Indeed, mean dissolved monomethylmercury concentrations were low and similar in both rivers (0.03-0.06 ng L-1), while they were 10 times higher (up to 0.56 ng L-1) in the water outflowing the hydroelectric dam. Dissolved monomethylmercury determinations along a water column profile suggest that methylation of inorganic mercury occurs in the deep anoxic part in reservoir. We conclude that mercury mobilization related to gold mining is not solely sufficient to account for high concentrations in fish and that environmental conditions that favor mercury methylation, such as anoxia, are needed.

Published
2005

22. Comparison Between NaCl Tolerance Response and Acclimation to Cold Temperature in Shewanella putrefaciens

Author

Yanick Auffray, Françoise Leroi, Céline Leboeuf, Laurence Leblanc, Axel Hartke, Institut universitaire de formation des maîtres - Nord-Pas-de-Calais (IUFM Nord-Pas-de-Calais), Université d'Artois (UA), Interactions cellulaires et moléculaires (ICM), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Microbiologie de l’Environnement (LME), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-IFR140-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Institut Français de Recherche pour l'Exploitation de la Mer - Nantes (IFREMER Nantes), Université de Nantes (UN), Institut National de la Recherche Agronomique (INRA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), and Institut Français de Recherche pour l'Exploitation de la Mer - Atlantique (IFREMER Atlantique)

Subjects
Acclimatization, [SDV]Life Sciences [q-bio], Molecular Sequence Data, Shewanella putrefaciens, Reductase, Sodium Chloride, Applied Microbiology and Biotechnology, Microbiology, 03 medical and health sciences, Bacterial Proteins, Vibrionaceae, Osmotic Pressure, Electrophoresis, Gel, Two-Dimensional, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Amino Acid Sequence, Incubation, 030304 developmental biology, Northern Blot Analysis, chemistry.chemical_classification, 0303 health sciences, Strain (chemistry), biology, Osmotic concentration, 030306 microbiology, General Medicine, Peroxiredoxins, biology.organism_classification, Hydroperoxide, Cold Temperature, Enzyme, chemistry, Biochemistry, Peroxidases, 13. Climate action, Polypeptide, Northern Blot, Sequence Alignment
Abstract

International audience; Two strains of the spoiling bacterium S. putrefaciens showed an adaptation capacity to hyperosmotic shock when they were pretreated with a sublethal concentration of NaCl. The maximal tolerance factor for the CIP 69.29 strain was obtained when cells were incubated for 1 h in the presence of 1.5% NaCl, whereas for the J13.1 strain, an incubation of 15 min in the presence of 1% NaCl seemed to be the optimal conditions to harden the cells against a subsequent lethal salt treatment. During NaCl adaptation and growth at low temperatures (2°C), 37 and 32 polypeptides were induced respectively. Interestingly, 11 proteins were common between the two different stress responses. These proteins and the corresponding genes seem to play a key role in the observed cross-protection towards the NaCl challenge induced by growth of the cultures at 2°C. One of the overlapping proteins has been identified to correspond to the alkyl hydroperoxide reductase (AhpC) of S. putrefaciens. Northern blot analysis showed that induction of this enzyme was accompanied by accumulation of the corresponding transcript under both conditions.

Published
2003
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