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Chen CT, Carlotti F, Harmelin-Vivien M, Letourneur Y, Savoye N, Guillou G, Lebreton B, Tesán-Onrubia JA, Barani A, Cornet V, Guilloux L, Esposito A, Ré C, Bănaru D. Isotopic and biochemical trophic markers reveal the complexity of interactions at the base of pelagic food webs (Mediterranean sea). Mar Environ Res 2023; 190:106123. [PMID: 37567088 DOI: 10.1016/j.marenvres.2023.106123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 08/01/2023] [Accepted: 08/02/2023] [Indexed: 08/13/2023]
Abstract
To gain insight into the impact of bottom-up changes in the plankton community on planktivorous fish in the context of the decline of small pelagic fisheries in the Northwestern Mediterranean Sea, we have conducted an extensive year-long study. The investigation combined biochemical analyses (proteins, carbohydrates, and lipids) with C and N stable isotope analyses (SIA) to simultaneously study phytoplankton, zooplankton, and eight planktivorous fish species (Engraulis encrasicolus, Sardina pilchardus, Sardinella aurita, Sprattus sprattus, Cepola macrophthalma, Chromis chromis, Boops boops, and Spicara maena). This study is the first to analyze both stable isotope and biochemical compositions in coastal particulate organic matter (POM) size classes (0.7-2.7 μm, 2.7-20 μm, and 20-200 μm), zooplankton size classes (200-300 μm, 300-500 μm, 500-1000 μm, 1000-2000 μm, and >2000 μm), and taxonomic groups. We demonstrated that: (1) POM stable isotope compositions varied based on its spatial origin, the taxonomic composition of its biota, and its biochemical content; (2) δ15N values increased with zooplankton size classes and groups, indicating different trophic levels; (3) Phytoplankton exhibited a lipid-rich composition (∼55%), while zooplankton and fish muscles were protein-rich (∼61% and ∼66%, respectively). Bayesian stable isotope mixing models revealed that, on average: (1) POM from oceanic waters contributed the most to the POM in the bay (>51%), with a dominance of pico-POM (∼43%); (2) The 200-1000 μm zooplankton primarily consumed nano-POM, the 1000-2000 μm zooplankton mostly consumed micro-POM (∼64%), and the >2000 μm zooplankton also mostly consumed micro-POM; (3) Mesozooplankton (200-2000 μm) constituted the main portion (∼42%) of the diet for planktivorous fish species, while macrozooplankton organisms (>2000 μm) were the primary food resource (∼43%) for both B. boops and S. sprattus. Our study underscores the complexity of the pelagic food web and highlights the bottom-up transfer of organic matter from the smallest phytoplankton size fractions to planktivorous fish.
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Affiliation(s)
- Chia-Ting Chen
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - François Carlotti
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Mireille Harmelin-Vivien
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Yves Letourneur
- Université de La Nouvelle-Calédonie, UMR Entropie (UR/IRD/CNRS/IFREMER/UNC), LabEx-CORAIL, BP R4, 98851, Nouméa cedex, New Caledonia.
| | - Nicolas Savoye
- UMR 5805 EPOC, Université de Bordeaux/CNRS, Pessac, Arcachon, France.
| | - Gaël Guillou
- UMR 7266 Littoral, Environnement et Sociétés (CNRS - Université de la Rochelle), 2 rue Olympe de Gouges, 17000, La Rochelle, France.
| | - Benoit Lebreton
- UMR 7266 Littoral, Environnement et Sociétés (CNRS - Université de la Rochelle), 2 rue Olympe de Gouges, 17000, La Rochelle, France.
| | - Javier A Tesán-Onrubia
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Aude Barani
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Véronique Cornet
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Loïc Guilloux
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Anaïs Esposito
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France; UMR 6134 UMR CNRS SPE 6134, Université de Corse Pascal Paoli, F-20250, Corte, France.
| | - Christian Ré
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
| | - Daniela Bănaru
- Aix-Marseille Université et Université de Toulon, Mediterranean Institute of Oceanography (MIO), CNRS/INSU, IRD, UM 110, Campus Universitaire de Luminy, case 901, 13288, Marseille cedex 9, France.
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Tesán-Onrubia JA, Tedetti M, Carlotti F, Tenaille M, Guilloux L, Pagano M, Lebreton B, Guillou G, Fierro-González P, Guigue C, Chifflet S, Garcia T, Boudriga I, Belhassen M, Zouari AB, Bănaru D. Spatial variations of biochemical content and stable isotope ratios of size-fractionated plankton in the Mediterranean Sea (MERITE-HIPPOCAMPE campaign). Mar Pollut Bull 2023; 189:114787. [PMID: 36878021 DOI: 10.1016/j.marpolbul.2023.114787] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 02/20/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
Plankton represents the main source of carbon in marine ecosystems and is consequently an important gateway for contaminants into the marine food webs. During the MERITE- HIPPOCAMPE campaign in the Mediterranean Sea (April-May 2019), plankton was sampled from pumping and net tows at 10 stations from the French coast to the Gulf of Gabès (Tunisia) to obtain different size fractions in contrasted regions. This study combines various approaches, including biochemical analyses, analyses of stable isotope ratios (δ13C, δ15N), cytometry analyses and mixing models (MixSiar) on size-fractions of phyto- and zooplankton from 0.7 to >2000 μm. Pico- and nanoplankton represented a large energetic resource at the base of pelagic food webs. Proteins, lipids, and stable isotope ratios increased with size in zooplankton and were higher than in phytoplankton. Stable isotope ratios suggest different sources of carbon and nutrients at the base of the planktonic food webs depending on the coast and the offshore area. In addition, a link between productivity and trophic pathways was shown, with high trophic levels and low zooplankton biomass recorded in the offshore area. The results of our study highlight spatial variations of the trophic structure within the plankton size-fractions and will contribute to assess the role of the plankton as a biological pump of contaminants.
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Affiliation(s)
| | - Marc Tedetti
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - François Carlotti
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Melissa Tenaille
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Loïc Guilloux
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Marc Pagano
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Benoit Lebreton
- UMR 7266 Littoral Environnement et Sociétés (CNRS - La Rochelle Université), La Rochelle, France
| | - Gaël Guillou
- UMR 7266 Littoral Environnement et Sociétés (CNRS - La Rochelle Université), La Rochelle, France
| | - Pamela Fierro-González
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Catherine Guigue
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Sandrine Chifflet
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Théo Garcia
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France
| | - Ismail Boudriga
- Institut National des Sciences et Technologies de la Mer (INSTM), 28, rue 2 mars 1934, 24, Salammbô 2025, Tunisia
| | - Malika Belhassen
- Institut National des Sciences et Technologies de la Mer (INSTM), 28, rue 2 mars 1934, 24, Salammbô 2025, Tunisia
| | - Amel Bellaaj Zouari
- Institut National des Sciences et Technologies de la Mer (INSTM), 28, rue 2 mars 1934, 24, Salammbô 2025, Tunisia
| | - Daniela Bănaru
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France.
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van der Heijden LH, Graeve M, Asmus R, Rzeznik-Orignac J, Niquil N, Bernier Q, Guillou G, Asmus H, Lebreton B. Trophic importance of microphytobenthos and bacteria to meiofauna in soft-bottom intertidal habitats: A combined trophic marker approach. Mar Environ Res 2019; 149:50-66. [PMID: 31153060 DOI: 10.1016/j.marenvres.2019.05.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/22/2019] [Accepted: 05/20/2019] [Indexed: 06/09/2023]
Abstract
Meiofauna can play an important role in the carbon fluxes of soft-bottom coastal habitats. Investigation of their feeding behavior and trophic position remains challenging due to their small size. In this study, we determine and compare the food sources used by nematodes and benthic copepods by using stable isotope compositions, fatty acid profiles and compound specific isotope analyses of fatty acids in the mudflats, seagrass beds and a sandflat of the Marennes-Oléron Bay, France, and the Sylt-Rømø Bight, Germany. Suspended particulate organic matter was much more 13C-depleted than other food sources and meiofauna, highlighting its poor role in the different studied habitats. The very low proportions of vascular plant fatty acid markers in meiofauna demonstrated that these consumers did not rely on this food source, either fresh or detrital, even in seagrass beds. The combined use of stable isotopes and fatty acids emphasized microphytobenthos and benthic bacteria as the major food sources of nematodes and benthic copepods. Compound specific analyses of a bacteria marker confirmed that bacteria mostly used microphytobenthos as a substrate.
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Affiliation(s)
- L H van der Heijden
- UMR 7266 Littoral, Environment et Societies (CNRS - University of La Rochelle), Institute du littoral et de l'environnement, 2 rue Olympe de Gouges, 17000, La Rochelle, France; Alfred Wegener Institute Helmholtz Centre for Polar- and Marine Research, Wattenmeerstation Sylt, Hafenstraße 43, 25992, List, Sylt, Germany.
| | - M Graeve
- Alfred Wegener Institut Helmholtz Centre for Polar- and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany
| | - R Asmus
- Alfred Wegener Institute Helmholtz Centre for Polar- and Marine Research, Wattenmeerstation Sylt, Hafenstraße 43, 25992, List, Sylt, Germany
| | - J Rzeznik-Orignac
- UMR 8222 Laboratoire d'Ecogéochimie des Environnements Benthiques, (CNRS - Sorbonne Université), Observatoire Océanologique de Banyuls, 1 avenue Pierre Fabre, 66650, Banyuls-sur-Mer, France
| | - N Niquil
- UMR 7208 Unité Biologie des Organismes et Ecosystèmes Aquatiques (MNHN - CNRS - IRD - Sorbonne Université - Université de Caen Normandie - Université des Antilles), Esplanade de la Paix, 14000, CAEN, France
| | - Q Bernier
- UMR 7266 Littoral, Environment et Societies (CNRS - University of La Rochelle), Institute du littoral et de l'environnement, 2 rue Olympe de Gouges, 17000, La Rochelle, France
| | - G Guillou
- UMR 7266 Littoral, Environment et Societies (CNRS - University of La Rochelle), Institute du littoral et de l'environnement, 2 rue Olympe de Gouges, 17000, La Rochelle, France
| | - H Asmus
- Alfred Wegener Institute Helmholtz Centre for Polar- and Marine Research, Wattenmeerstation Sylt, Hafenstraße 43, 25992, List, Sylt, Germany
| | - B Lebreton
- UMR 7266 Littoral, Environment et Societies (CNRS - University of La Rochelle), Institute du littoral et de l'environnement, 2 rue Olympe de Gouges, 17000, La Rochelle, France
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Rubio KS, Ajemian M, Stunz GW, Palmer TA, Lebreton B, Beseres Pollack J. Dietary composition of black drum Pogonias cromis in a hypersaline estuary reflects water quality and prey availability. J Fish Biol 2018; 93:250-262. [PMID: 29935002 DOI: 10.1111/jfb.13654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
The Baffin Bay estuary is a hypersaline system in the Gulf of Mexico that supports an important recreational and commercial fishery for black drum Pogonias cromis, a benthic predator. Seasonal measurements of water quality variables, benthic macrofauna densities and biomass, and determination of P. cromis food sources using stomach-content and stable-isotope analyses were carried out to determine how P. cromis food sources change with water quality and how this may affect P. cromis diet. Gut-content analysis indicated P. cromis selectively consumed bivalves Mulinia lateralis and Anomalocardia auberiana. Isotope compositions demonstrated that P. cromis relied on these benthic food resources produced in the Baffin Bay estuary year-round. Biomass and densities of these bivalves were influenced by changes in water quality variables, particularly salinity and dissolved oxygen. Thus, this paper demonstrates the relationship between water quality variables, benthic macrofauna, and their use as food resources by a carnivorous fish species, and emphasizes the need for integrated assessments when studying the effects of water quality on ecosystem function. Holistic approaches such as these can provide important information for management and conservation of fishery resources and can improve predictions of ecosystem response to climate variability.
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Affiliation(s)
- Kathryn S Rubio
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas
| | - Matthew Ajemian
- Florida Atlantic University, Harbor Branch Oceanographic Institute, Fort Pierce, Florida
| | - Gregory W Stunz
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas
- Harte Research Institute for Gulf of Mexico Studies, Texas A&M University, Corpus Christi, Texas
| | - Terence A Palmer
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas
| | - Benoit Lebreton
- UMR Littoral, Environment et Societies, CNRS - University of La Rochelle, Institut du littoral et de l'environnement, La Rochelle, France
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Rezek RJ, Lebreton B, Sterba-Boatwright B, Beseres Pollack J. Ecological structure and function in a restored versus natural salt marsh. PLoS One 2017; 12:e0189871. [PMID: 29261795 PMCID: PMC5736197 DOI: 10.1371/journal.pone.0189871] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 12/04/2017] [Indexed: 11/18/2022] Open
Abstract
Habitat reconstruction is commonly employed to restore degraded estuarine habitats and lost ecological functions. In this study, we use a combination of stable isotope analyses and macrofauna community analysis to compare the ecological structure and function between a recently constructed Spartina alterniflora salt marsh and a natural reference habitat over a 2-year period. The restored marsh was successful in providing habitat for economically and ecologically important macrofauna taxa; supporting similar or greater density, biomass, and species richness to the natural reference during all but one sampling period. Stable isotope analyses revealed that communities from the natural and the restored marshes relied on a similar diversity of food resources and that decapods had similar trophic levels. However, some generalist consumers (Palaemonetes spp. and Penaeus aztecus) were more 13C-enriched in the natural marsh, indicating a greater use of macrophyte derived organic matter relative to restored marsh counterparts. This difference was attributed to the higher quantities of macrophyte detritus and organic carbon in natural marsh sediments. Reduced marsh flooding frequency was associated with a reduction in macrofaunal biomass and decapod trophic levels. The restored marsh edge occurred at lower elevations than natural marsh edge, apparently due to reduced fetch and wind-wave exposure provided by the protective berm structures. The lower elevation of the restored marsh edge mitigated negative impacts in sampling periods with low tidal elevations that affected the natural marsh. The results of this study highlight the importance of considering sediment characteristics and elevation in salt marsh constructions.
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Affiliation(s)
- Ryan J. Rezek
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas, United States of America
| | - Benoit Lebreton
- Littoral Environnement et Sociétés, CNRS - Université de La Rochelle, La Rochelle, France
| | - Blair Sterba-Boatwright
- Department of Mathematics and Statistics, Texas A&M University - Corpus Christi, Corpus Christi, Texas, United States of America
| | - Jennifer Beseres Pollack
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, Texas, United States of America
- * E-mail:
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Blomberg BN, Lebreton B, Palmer TA, Guillou G, Beseres Pollack J, Montagna PA. Does reef structure affect oyster food resources? A stable isotope assessment. Mar Environ Res 2017; 127:32-40. [PMID: 28336052 DOI: 10.1016/j.marenvres.2017.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 03/02/2017] [Accepted: 03/10/2017] [Indexed: 06/06/2023]
Abstract
As ecosystem engineers, oysters create and maintain structured habitat and can influence trophodynamics and benthic-pelagic coupling in the surrounding landscape. The physical reef structure and associated biotic parameters can affect the availability of food resources for oysters. Oysters and potential composite food sources - suspended particulate organic matter (SPOM) and surface sediment organic matter (SSOM) - were assessed using a dual stable isotope (δ13C, δ15N) approach at three reef types (natural, restored, and unconsolidated) seasonally for two years to determine if changes in physical and/or biotic parameters affected the relative availability and/or use of food resources by oysters. SPOM was more depleted in 13C (-24.2 ± 0.6‰, mean ± SD) than SSOM (-21.2 ± 0.8‰). SPOM composition is likely dominated by autochthonous phytoplankton production, while SSOM includes trapped phytoplankton and benthic microalgae. SSOM was used by oysters in increasing proportions relative to SPOM over time at all reef types. This temporal trend is likely due to increased oyster biomass over time, promoting enhanced microphytobenthos growth through feedback effects related to oyster biodeposits. Structural differences between reef types observed in this study had no effect on food resource availability and use by oysters, indicating strong bentho-pelagic coupling likely due to shallow depths as well as strong and consistent winds. This study provides insights for restoration of oyster reefs as it highlights that food resources used by oysters remain similar among reef types despite changes in abiotic and biotic parameters among habitats and over time.
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Affiliation(s)
- Brittany N Blomberg
- Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA.
| | - Benoit Lebreton
- Institut du Littoral et de l'Environnement, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France.
| | - Terence A Palmer
- Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA.
| | - Gaël Guillou
- Institut du Littoral et de l'Environnement, Université de La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France.
| | - Jennifer Beseres Pollack
- Department of Life Sciences, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5800, Corpus Christi, TX 78412-5800, USA.
| | - Paul A Montagna
- Harte Research Institute for Gulf of Mexico Studies, Texas A&M University - Corpus Christi, 6300 Ocean Drive, Unit 5869, Corpus Christi, TX 78412-5869, USA.
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Rezek RJ, Lebreton B, Roark EB, Palmer TA, Pollack JB. How does a restored oyster reef develop? An assessment based on stable isotopes and community metrics. Mar Biol 2017; 164:54. [PMID: 0 DOI: 10.1007/s00227-017-3084-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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de la Vega C, Lebreton B, Siebert U, Guillou G, Das K, Asmus R, Asmus H. Seasonal Variation of Harbor Seal's Diet from the Wadden Sea in Relation to Prey Availability. PLoS One 2016; 11:e0155727. [PMID: 27176227 PMCID: PMC4866785 DOI: 10.1371/journal.pone.0155727] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 05/03/2016] [Indexed: 11/21/2022] Open
Abstract
The Wadden Sea has an important role for marine mammals in terms of resting, nursing and foraging. Harbor seal is the most abundant marine mammal species in this area. The use of the food resources of the Wadden Sea by seals is not clear, and previous studies showed that this species can travel kilometers away from their haul-outs to forage in the North Sea. In this study, we analyzed the stable isotopes of vibrissae from 23 dead harbor seals found on the island of Sylt to investigate their diet. The predator´s carbon and nitrogen isotope compositions were compared to the compositions of different potential prey items from the Sylt-Rømø Bight and from the North Sea in order to study seasonal pattern in the diet and in the foraging location. In parallel, seasonal variation of abundance and biomass of the potential prey items from the Sylt-Rømø Bight were studied and compare to their contribution to the seal´s diet. The results revealed a change in the seal´s diet from pelagic sources in spring to a benthic based diet in summer, and an increasing use of the North Sea resources in fall and winter in accordance with the seasonal variation of the availability of prey in the Sylt-Rømø Bight.
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Affiliation(s)
- Camille de la Vega
- AlfredWegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Wattenmeerstation Sylt Hafenstr. 43, D-25992 List/ Sylt, Germany
- * E-mail:
| | - Benoit Lebreton
- Littoral Environnement et Sociétés (LIENSs), CNRS-Université de la Rochelle, Bâtiment ILE 2, rue Olympe de Gouges 17 000 La Rochelle, France
| | - Ursula Siebert
- Stiftung Tierärztliche Hochschule Hannover Institut für Terrestrische und Aquatische Wildtierforschung Werftstr. 6, 25761 Büsum, Germany
| | - Gael Guillou
- Littoral Environnement et Sociétés (LIENSs), CNRS-Université de la Rochelle, Bâtiment ILE 2, rue Olympe de Gouges 17 000 La Rochelle, France
| | - Krishna Das
- Laboratory of oceanology—MARE center, Université de Liège, Allée de la Chimie 3, Bât. B6c, 4000 Liège (Sart-Tilman), Belgium
| | - Ragnhild Asmus
- AlfredWegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Wattenmeerstation Sylt Hafenstr. 43, D-25992 List/ Sylt, Germany
| | - Harald Asmus
- AlfredWegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Wattenmeerstation Sylt Hafenstr. 43, D-25992 List/ Sylt, Germany
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Masbou J, Point D, Guillou G, Sonke JE, Lebreton B, Richard P. Carbon Stable Isotope Analysis of Methylmercury Toxin in Biological Materials by Gas Chromatography Isotope Ratio Mass Spectrometry. Anal Chem 2015; 87:11732-8. [DOI: 10.1021/acs.analchem.5b02918] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jeremy Masbou
- Observatoire
Midi-Pyrénées, Géosciences Environnement Toulouse, UMR CNRS 5563/IRD 234/Université Paul Sabatier Toulouse 3, 14 avenue
Edouard Belin, 31400 Toulouse, France
| | - David Point
- Observatoire
Midi-Pyrénées, Géosciences Environnement Toulouse, UMR CNRS 5563/IRD 234/Université Paul Sabatier Toulouse 3, 14 avenue
Edouard Belin, 31400 Toulouse, France
| | - Gaël Guillou
- UMR
Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Jeroen E. Sonke
- Observatoire
Midi-Pyrénées, Géosciences Environnement Toulouse, UMR CNRS 5563/IRD 234/Université Paul Sabatier Toulouse 3, 14 avenue
Edouard Belin, 31400 Toulouse, France
| | - Benoit Lebreton
- UMR
Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Pierre Richard
- UMR
Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, 17000 La Rochelle, France
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Nguetseng R, Fliedner A, Knopf B, Lebreton B, Quack M, Rüdel H. Retrospective monitoring of mercury in fish from selected European freshwater and estuary sites. Chemosphere 2015; 134:427-434. [PMID: 25989521 DOI: 10.1016/j.chemosphere.2015.04.094] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/23/2015] [Accepted: 04/28/2015] [Indexed: 06/04/2023]
Abstract
Levels and trends of total mercury (THg) and methylmercury (MeHg) compounds in bream (Abramis brama) from different European sites were compared. Bream were collected between 2007 and 2013 in the estuaries of the rivers Scheldt (Netherlands), Rhône (France), Göta älv (Sweden), Tees (United Kingdom), and Mersey (UK), and in Lake Belau (Germany). A direct mercury analyzer was used to determine THg concentrations while MeHg was measured by gas chromatography/inductively coupled plasma-mass spectrometry applying stable isotope dilution. THg and MeHg in annual pool samples of bream ranged between 15.9 and 251 μg kg(-1) wet weight (ww) with lowest concentrations found at the reference site Lake Belau and highest in samples from the river Rhône. The EU environmental quality standard (EQS) of 20 μg kg(-1) ww was exceeded at all sites and in all years except at Lake Belau in 2012. Significantly decreasing trends over time were observed only in bream from the Rhône, while THg increased in bream from the Western Scheldt. The MeHg fractions of THg were always >80% and a significant difference between sites was detected only in one case (Rhône vs. Lake Belau).
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Affiliation(s)
- Regine Nguetseng
- Fraunhofer Institute for Molecular Biology and Applied Ecology (Fraunhofer IME), 57392 Schmallenberg, Germany
| | - Annette Fliedner
- Fraunhofer Institute for Molecular Biology and Applied Ecology (Fraunhofer IME), 57392 Schmallenberg, Germany
| | - Burkhard Knopf
- Fraunhofer Institute for Molecular Biology and Applied Ecology (Fraunhofer IME), 57392 Schmallenberg, Germany.
| | - Benoit Lebreton
- UMR Littoral, Environnement et Sociétés (LIENSs), CNRS - Université de La Rochelle, Institut du littoral et de l'environnement, 17000 La Rochelle, France
| | - Markus Quack
- Department of Biogeography, Trier University, 54286 Trier, Germany
| | - Heinz Rüdel
- Fraunhofer Institute for Molecular Biology and Applied Ecology (Fraunhofer IME), 57392 Schmallenberg, Germany
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Paar M, Voronkov A, Hop H, Brey T, Bartsch I, Schwanitz M, Wiencke C, Lebreton B, Asmus R, Asmus H. Temporal shift in biomass and production of macrozoobenthos in the macroalgal belt at Hansneset, Kongsfjorden, after 15 years. Polar Biol 2015. [DOI: 10.1007/s00300-015-1760-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Sardenne F, Ménard F, Degroote M, Fouché E, Guillou G, Lebreton B, Hollanda SJ, Bodin N. Methods of lipid-normalization for multi-tissue stable isotope analyses in tropical tuna. Rapid Commun Mass Spectrom 2015; 29:1253-1267. [PMID: 26395609 DOI: 10.1002/rcm.7215] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 04/13/2015] [Accepted: 04/17/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE The bias associated with lipid contents in fish tissues is a recalcitrant topic for trophic studies using stable isotopes. Lipids are depleted in the heavy carbon isotope ((13)C) and the lipid content varies considerably among species, tissues and in both time and space. We have applied and assessed different correction methods for tropical tuna tissues. METHODS We tested two types of normalization methods to deal with variable lipid content in liver, gonads, and white and red muscles of yellowfin, bigeye and skipjack tuna: a chemical extraction using dichloromethane and a mathematical correction based on three modeling approaches (linear, non-linear and mass balance models). We measured isotopic ratios of bulk and lipid-free tissues and assessed the predictive ability of the correction models with the lipid-free measurements. The parameters of the models were estimated from our dataset and from results from published studies on other species. RESULTS Comparison between bulk, lipid-free and lipid-corrected isotopic ratios demonstrated that (1) chemical extraction using dichloromethane did not affect δ(15)N values; (2) the change in δ(13)C values after extraction was tissue-specific; (3) lipid-normalization models using published parameter estimates failed to predict lipid-corrected δ(13)C values; and (4) linear and non-linear models using parameters estimated for each tissue from our dataset provided accurate δ(13)C predictions for all tissues, and mass balance model for white muscle only. CONCLUSIONS Models using published estimates for parameters from other species cannot be used. Based on a range of lipid content that do not exceed 45%, we recommend the linear model to correct the bulk δ(13)C values in the investigated tissues but the parameters have to be estimated from a proportion of the original data for which chemical extraction is required and the isotopic values of bulk and lipid-free tissues are measured.
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Affiliation(s)
- Fany Sardenne
- IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Avenue Jean Monnet, Sète, France
- IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles
| | - Frédéric Ménard
- IRD, Mediterranean Institute of Oceanography (MIO), Aix-Marseille Université/CNRS/IRD/Université de Toulon, 13288, Marseille, France
| | - Maxime Degroote
- IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Avenue Jean Monnet, Sète, France
| | - Edwin Fouché
- IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Avenue Jean Monnet, Sète, France
- INRA, UMR TOXALIM (Research Centre in Food Toxicology), Toulouse, France
| | - Gaël Guillou
- CNRS-Université de la Rochelle, UMR Littoral Environnement et Sociétés (LIENSs), 2 rue Olympe de Gouges, 17000, La Rochelle, France
| | - Benoit Lebreton
- CNRS-Université de la Rochelle, UMR Littoral Environnement et Sociétés (LIENSs), 2 rue Olympe de Gouges, 17000, La Rochelle, France
| | | | - Nathalie Bodin
- IRD, UMR MARine Biodiversity Exploitation and Conservation (MARBEC), Fishing Port, Victoria, Seychelles
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Lebreton B, Richard P, Guillou G, Blanchard GF. Trophic shift in young-of-the-year Mugilidae during salt-marsh colonization. J Fish Biol 2013; 82:1297-1307. [PMID: 23557307 DOI: 10.1111/jfb.12069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 01/18/2013] [Indexed: 06/02/2023]
Abstract
This study investigated the trophic shift of young-of-the-year (YOY) thinlip grey mullet Liza ramada and golden grey mullet Liza aurata during their recruitment in a salt marsh located on the European Atlantic Ocean coast. Stable-isotope signatures (δ(13) C and δ(15) N) of the fishes followed a pattern, having enrichments in (13) C and (15) N with increasing fork length (LF ): δ(13) C in fishes < 30 mm ranged from -19.5 to -15.0‰, whereas in fishes > 30 mm δ(13) C ranged from -15.8 to -12.7‰, closer to the level in salt-marsh food resources. Large differences between the δ(15) N values of mugilids and those of food sources (6·0‰ on average) showed that YOY are secondary consumers, similar to older individuals, when feeding in the salt marsh. YOY mugilids shift from browsing on pelagic prey to grazing on benthic resources from the salt marsh before reaching 30 mm LF. The results highlight the role of European salt marshes as nurseries for juvenile mugilids.
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Affiliation(s)
- B Lebreton
- UMR Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, Bâtiment Marie Curie, Avenue Michel Crépeau, 17042, La Rochelle Cedex 1, France.
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Bonnefoy M, Laville M, Ecochard R, Jusot JF, Normand S, Maillot S, Lebreton B, Jauffret M. Effects of branched amino acids supplementation in malnourished elderly with catabolic status. J Nutr Health Aging 2010; 14:579-84. [PMID: 20818474 DOI: 10.1007/s12603-010-0090-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Among various nutrients branched amino acids (BCAAS) have been shown to be the most responsible for the stimulation of protein synthesis in various situations including catabolic states. OBJECTIVES We evaluated the effect of a small amount of proteins enriched with BCAAs (0.4 g/kg/day and 0.2 g/kg/day BCAAs) on body weight and composition; nitrogen balance, energy intake and inflammation after 2 weeks of supplementation in acute elderly with catabolic status. DESIGN Two weeks randomized controlled trial. SETTING Geriatric department of teaching hospital. SUBJECTS Thirty patients with malnutrition and inflammatory process (MNA < 24, albumin < 30 g/l and CRP > or = 20 mg/l) who agreed to participate in the study were consecutively included. METHODS Body composition was determined by labelled water dilution method; resting energy expenditure (REE) was determined by indirect calorimetry; energy intake was calculated for a 3 days period at D1 and D12. Nutritional and inflammatory proteins and cytokines (IL-6 and TNF) were measured at day 1 and 14. RESULTS No difference was observed at day 14 between supplemented (S) and control (C) group for weight (S: 58.0 +/- 11.8 kg and C: 60.0 +/- 15.9 kg); fat free mass (S: 40.7 +/- 8.3 kg and C: 40 +/- 8.2 kg); nitrogen balance (S: 1.34 +/- 2.21 g/day and C: 0.59 +/- 4.47 g/day); and energy intake (S: 20 +/- 3.6 kcal/day and C: 20.5 +/- 8.6 kcal/day). Energy intake was at similar level than REE and clearly less than energy requirement in C and S. A significant decrease was observed for orosomucoid and Prognostic Inflammatory and Nutritional Index (PINI) in S. CONCLUSION Our results do not confirm improvement of nutritional status with enriched BCAAs supplementation as suggested in the literature. Persistence of inflammatory condition may be an explanation despite an improvement of inflammatory status was observed in the supplemented group. Those results show clearly that energy requirements are not covered in acute hospitalized elderly people. The fact that not only energy intake but also REE are decreased brings a new insight on catabolic situations.
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Affiliation(s)
- M Bonnefoy
- Service universitaire de médecine gériatrique, Centre Hospitalier Lyon-Sud, 69495 Pierre Bénite Cedex
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Ottens M, Lebreton B, Zomerdijk M, Rijkers MPWM, Bruinsma OSL, van der Wielen LAM. Impurity Effects on the Crystallization Kinetics of Ampicillin. Ind Eng Chem Res 2004. [DOI: 10.1021/ie0307028] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Ottens
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - B. Lebreton
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - M. Zomerdijk
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - M. P. W. M. Rijkers
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - O. S. L. Bruinsma
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - L. A. M van der Wielen
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
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Roman H, Verspyck E, Auliac JB, Lebreton B, Lemoine JP, Marpeau L. [Pregnancy, tuberculosis and inappropriate antidiuretic hormone secretion]. Gynecol Obstet Fertil 2002; 30:299-302. [PMID: 12043505 DOI: 10.1016/s1297-9589(02)00319-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report a pregnant woman presenting with seizure secondary to hyponatremia by inappropriate antidiuretic hormone secretion. Aetiology was unknown urinary and lung tuberculosis. This case report presents diagnosis strategy of inappropriate antidiuretic hormone secretion and the arguments for its aetiology.
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Affiliation(s)
- H Roman
- Clinique de gynécologie-obstétrique, CHU Charles Nicolle, 1, rue de Germont, 76031 Rouen, France.
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Affiliation(s)
- M. Ottens
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - B. Lebreton
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - M. Zomerdijk
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - M. P. W. M. Rijkers
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - O. S. L. Bruinsma
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
| | - L. A. M. van der Wielen
- Kluyver Laboratory for Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands, DSM Research, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Laboratory for Process Equipment, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands
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Lebreton B, Lyddiatt A. Application of aqueous two-phase partition to the production of homogeneous preparations of fluorescently labelled human serum albumin. J Chromatogr B Biomed Sci Appl 2000; 743:263-9. [PMID: 10942296 DOI: 10.1016/s0378-4347(99)00517-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The development of a traceable molecular probe was investigated for the monitoring of partition behaviour of biomolecules in aqueous two-phase systems. This work was based upon the selective labelling of the free thiol group of human serum albumin (i.e. Cys34) with the fluorophore N-(iodoacetylaminoethyl)-5-naphthylamine-1-sulphonic acid. The preparation of homogeneously labelled protein required purification operations. A succession of five processes was successfully applied, comprising two size-exclusion chromatographic operations by gel filtration and a series of three appropriately manipulated aqueous two-phase systems comprising PEG 1450 and phosphate salt. Aqueous two-phase partitioning is herein presented as an alternative to difficult separation and could be applied for 'fine' purifications.
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Affiliation(s)
- B Lebreton
- Kluyver Laboratory for Biotechnology, TU Delft, The Netherlands
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Lebreton B, Huddleston J, Lyddiatt A. Polymer-protein interactions in aqueous two phase systems: fluorescent studies of the partition behaviour of human serum albumin. J Chromatogr B Biomed Sci Appl 1998; 711:69-79. [PMID: 9699976 DOI: 10.1016/s0378-4347(98)00102-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study describes the partitioning of fluorescent macromolecules in aqueous two-phase systems (ATPS) comprising phosphate salt and poly(ethylene glycol) of three different molecular masses (i.e. 1000, 1450 and 2000 Da). The impact of system assembly was studied with fluorescent macromolecules introduced in contact with either (i) first salt, then polymer or (ii) first polymer, then salt, or (iii) with both salt and polymer simultaneously. Native human serum albumin (HSA) and derivatives labelled with N-(iodoacetylaminoethyl)-5-naphthylamine-1-sulphonic acid (1,5-IAEDANS) were partitioned using selected ATPS. Partitioning behaviour was characterised by molecular rotational studies of recovered proteins based upon changes of depolarisation. Measurements were undertaken by steady-state fluorescence or time-decay fluorescence using a single-photon counting system. In addition, circular dichroism was used as a tool for the study of macromolecular secondary structure. Two discrete categories of stable molecular structure have been identified that exist irrespective of the phase environment. The findings form the basis for a discussion of polymer protein interactions and the molecular micro-environment of proteins in ATPS.
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Affiliation(s)
- B Lebreton
- Biochemical Recovery Group, School of Chemical Engineering, University of Birmingham, UK
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Abstract
When yeast FLP recombinase is expressed from the phage lambda PR promoter in a Salmonella host, it cannot efficiently repress an operon controlled by an operator/promoter region that includes a synthetic, target FLP site. On the basis of this phenotype, we have identified four mutant FLP proteins that function as more efficient repressors of such an operon. At least two of these mutant FLP proteins bind better to the FLP site in vivo and in vitro. One mutant changes the presumed active site tyrosine residue of FLP protein to phenylalanine, is blocked in recombination, and binds the FLP site about five-fold better than the wild-type protein. A second mutant protein that functions as a more efficient repressor retains catalytic activity. We conclude that the eukaryotic yeast FLP recombinase, when expressed in a heterologous prokaryotic host, can function as a repressor, and that mutant FLP proteins that bind DNA more tightly may be selected as more efficient repressors.
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Affiliation(s)
- B Lebreton
- Department of Biological Sciences, University of Southern California, Los Angeles 90089-1481
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Bernard JM, Pinaud M, Bodinier F, Lebreton B, Prouteau P, Souron R. [Prevention of peroperative hypothermia]. Ann Fr Anesth Reanim 1986; 5:625-6. [PMID: 3826799 DOI: 10.1016/s0750-7658(86)80078-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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