Consulta: creatorFacets:"Panagiotopoulos, Christos"
Registros recuperados: 7
Data/hora: 01/06/2024 08:19:52

When riverine dissolved organic matter (DOM) meets labile DOM in coastal waters: changes in bacterial community activity and composition
Provedor de dados: 5
Autores: Blanchet, Marine; Pringault, Olivier; Panagiotopoulos, Christos; Lefevre, Dominique; Charriere, Bruno; Ghiglione, Jean-francois; Fernandez, Camila; Aparicio, Fran L.; Marrase, Celia; Catala, Philippe; Oriol, Louise; Caparros, Jocelyne; Joux, Fabien.
Heterotrophic bacterial communities in marine environments are exposed to a heterogeneous mixture of dissolved organic compounds with different bioreactivity that may control both their activity and composition. The coastal environment is an example of a mixing area where recalcitrant allochthonous organic matter from rivers can encounter labile organic matter from marine phytoplanktonic blooms. The objective of this study was to explore the effects of mixed qualities of dissolved organic matter (DOM) on bacterial community activity (BCA) and bacterial community composition (BCC) and to test for a priming effect when DOM sources are added in combination. Coastal marine bacterial communities were incubated separately with a mixture of amino acids and with...
Tipo: Text
Palavras-chave: Dissolved organic matter; Biodegradation; Coastal waters; Bacterial community composition; Priming effect.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00625/73737/74701.pdf

Modulation of the vertical particle transfer efficiency in the oxygen minimum zone off Peru
Provedor de dados: 5
Autores: Bretagnon, Marine; Paulmier, Aurelien; Garcon, Veronique; Dewitte, Boris; Illig, Serena; Leblond, Nathalie; Coppola, Laurent; Campos, Fernando; Velazco, Federico; Panagiotopoulos, Christos; Oschlies, Andreas; Martin Hernandez-ayon, J.; Maske, Helmut; Vergara, Oscar; Montes, Ivonne; Martinez, Philippe; Carrasco, Edgardo; Grelet, Jacques; Desprez-de-gesincourt, Olivier; Maes, Christophe; Scouarnec, Lionel.
The fate of the organic matter (OM) produced by marine life controls the major biogeochemical cycles of the Earth's system. The OM produced through photosynthesis is either preserved, exported towards sediments or degraded through remineralisation in the water column. The productive eastern boundary upwelling systems (EBUSs) associated with oxygen minimum zones (OMZs) would be expected to foster OM preservation due to low O-2 conditions. But their intense and diverse microbial activity should enhance OM degradation. To investigate this contradiction, sediment traps were deployed near the oxycline and in the OMZ core on an instrumented moored line off Peru. Data provided high-temporal-resolution O-2 series characterising two seasonal steady states at the...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00486/59764/62889.pdf

The composition and distribution of semi-labile dissolved organic matter across the southwest Pacific
Provedor de dados: 5
Autores: Panagiotopoulos, Christos; Pujo Pay, Mireille; Benavides, Mar; Van Wambeke, France; Sempéré, Richard.
The distribution and dynamics of dissolved organic carbon (DOC) and dissolved combined neutral sugars (DCNS) were studied across an increasing oligotrophic gradient (−18 to −22°N latitude) spanning from the Melanesian Archipelago (MA) area to the western part of the south Pacific gyre (WGY), in austral summer, as a part of the OUTPACE project. Our results showed DOC and DCNS concentrations exhibited little differences among the MA and WGY areas (0–200m: 55–78µMC for DOC and 1.5–2µMC for DCNS), however, a deeper penetration of DOC was noticeable at 150m depth at the WGY area. This finding was also reflected to the DOC and semi-labile DOC (DOCSL) stocks values (integration 0–200m) for which we found higher values in the WGY than the MA area. The high excess...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00448/56008/57517.pdf

One-Single Extraction Procedure for the Simultaneous Determination of a Wide Range of Polar and Nonpolar Organic Contaminants in Seawater
Provedor de dados: 5
Autores: Fauvelle, Vincent; Castro-jimenez, Javier; Schmidt, Natascha; Carlez, Benoit; Panagiotopoulos, Christos; Sempere, Richard.
A rapid analytical method including one-single solid-phase extraction (SPE) procedure followed by gas and liquid chromatography coupled with high resolution mass spectrometry detection (GC-MS and LC-HRMS respectively) was developed for the quantification of 40 organic compounds (1.6 &lt; log K-ow &lt; 9.5) in seawater including both legacy and emerging contaminants, with a focus on the most common plastic organic additives. This new method allowed for the analyses of nine organophosphate esters (OPEs), seven phthalates (PAEs), six bisphenols (BPs), five perfluorinated compounds (PFCs), and thirteen legacy organochlorinated compounds (OCs, including polychlorobiphenyles and pesticides) with recoveries in the ranges of 57-124% for OPEs, 52-163% for PAEs,...
Tipo: Text
Palavras-chave: Plastic additive; Seawater; Organic contaminants; Legacy contaminants; Phtalates; Bisphenol; Organophosphate esters.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00645/75716/76697.pdf

Potential bioavailability of organic matter from atmospheric particles to marine heterotrophic bacteria
Provedor de dados: 5
Autores: Djaoudi, Kahina; Van Wambeke, France; Barani, Aude; Bhairy, Nagib; Chevaillier, Servanne; Desboeufs, Karine; Nunige, Sandra; Labiadh, Mohamed; Des Tureaux, Thierry Henry; Lefevre, Dominique; Nouara, Amel; Panagiotopoulos, Christos; Tedetti, Marc; Pulido-villena, Elvira.
The surface ocean receives important amounts of organic carbon from atmospheric deposition. The degree of bioavailability of this source of organic carbon will determine its impact on the marine carbon cycle. In this study, the potential availability of dissolved organic carbon (DOC) leached from both desert dust and anthropogenic aerosols to marine heterotrophic bacteria was investigated. The experimental design was based on 16 d incubations, in the dark, of a marine bacterial inoculum into artificial seawater amended with water-soluble Saharan dust (D treatment) and anthropogenic (A treatment) aerosols, so that the initial DOC concentration was similar between treatments. Glucose-amended (G) and non-amended (control) treatments were run in parallel. Over...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00677/78941/81326.pdf

Sugar dynamics in large particles during in vitro incubation experiments
Provedor de dados: 5
Autores: Panagiotopoulos, Christos; Sempere, Richard.
Large particles (&gt; 60 mu m) were collected using in situ pumps deployed at 30 and 200 m depth at 2 typical stations in the southern Indian Ocean (Polar Front Zone [PFZ] and Sub-Antarctic Area [SAr]). The samples were incubated in vitro with their own bacterial assemblages for 7 to 17 days in batches under oxic conditions in the dark. Particulate organic carbon (POC) and sugars were monitored over time. Particulate sugars (PCHO-C) accounted for 5 to 20% of POC in the SAr, while they represented 5 to 8% of POC in the PFZ station at the beginning of the experiments. Molecular level analysis indicated that at the time of collection, ribose was among the most abundant sugars (18 to 30 wt% of PCHO-C) at the PFZ station and was rapidly degraded (k = 0.051 to...
Tipo: Text
Palavras-chave: Sinking particles; In vitro incubation experiments; Sugar degradation; Southern Indian Ocean.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00236/34737/33181.pdf

Green Edge ice camp campaigns: understanding the processes controlling the under-ice Arctic phytoplankton spring bloom
Provedor de dados: 5
Autores: Massicotte, Philippe; Amiraux, Rémi; Amyot, Marie-pier; Archambault, Philippe; Ardyna, Mathieu; Arnaud, Laurent; Artigue, Lise; Aubry, Cyril; Ayotte, Pierre; Bécu, Guislain; Bélanger, Simon; Benner, Ronald; Bittig, Henry C; Bricaud, Annick; Brossier, Eric; Bruyant, Flavienne; Chauvaud, Laurent; Christiansen-stowe, Debra; Claustre, Hervé; Cornet-barthaux, Véronique; Coupel, Pierre; Cox, Christine; Delaforge, Aurélie; Dezutter, Thibault; Dimier, Céline; Dominé, Florent; Dufour, Francis; Dufresne, Christiane; Dumont, Dany; Ehn, Jens; Else, Brent; Ferland, Joannie; Forget, Marie-hélène; Fortier, Louis; Gali, Marti; Galindo, Virginie; Gallinari, Morgane; Garcia, Nicole; Gerikas-ribeiro, Catherine; Gourdal, Margaux; Gourvil, Priscilla; Goyens, Clemence; Grondin, Pierre-luc; Guillot, Pascal; Guilmette, Caroline; Houssais, Marie-noëlle; Joux, Fabien; Lacour, Léo; Lacour, Thomas; Lafond, Augustin; Lagunas, José; Lalande, Catherine; Laliberté, Julien; Lambert-girard, Simon; Larivière, Jade; Lavaud, Johann; Lebaron, Anita; Leblanc, Karine; Le Gall, Florence; Legras, Justine; Lemire, Mélanie; Levasseur, Maurice; Leymarie, Edouard; Leynaert, Aude; Lopes Dos Santos, Adriana; Lourenço, Antonio; Mah, David; Marec, Claudie; Marie, Dominique; Martin, Nicolas; Marty, Constance; Marty, Sabine; Massé, Guillaume; Matsuoka, Atsushi; Matthes, Lisa; Moriceau, Brivaela; Muller, Pierre-emmanuel; Mundy, Christopher-john; Neukermans, Griet; Oziel, Laurent; Panagiotopoulos, Christos; Pangazi, Jean-jacques; Picard, Ghislain; Picheral, Marc; Pinczon Du Sel, France; Pogorzelec, Nicole; Probert, Ian; Queguiner, Bernard; Raimbault, Patrick; Ras, Joséphine; Rehm, Eric; Reimer, Erin; Rontani, Jean-françois; Rysgaard, Soren; Saint-béat, Blanche; Sampei, Makoto; Sansoulet, Julie; Schmidt, Sabine; Sempere, Richard; Sevigny, Caroline; Shen, Yuan; Tragin, Margot; Tremblay, Jean-eric; Vaulot, Daniel; Verin, Gauthier; Vivier, Frédéric; Vladoiu, Anda; Whitehead, Jeremy; Babin, Marcel.
The Green Edge initiative was developed to investigate the processes controlling the primary productivity and the fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797N, 63.7895W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea ice cover from the surface to the bottom at 360 m depth to better understand the factors driving the PSB. Key variables such as temperature, salinity, radiance, irradiance, nutrient concentrations, chlorophyll-a concentration,...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00598/71000/69266.pdf