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| Registros recuperados: 18 | |
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| Krichen, Emna; Rapaport, A.; Fouilland, Eric. |
| We address the problem of determining functional framing from experimental data points in view of robust time-varying predictions, which is of crucial importance in bioprocess monitoring. We propose a method that provides guaranteed functional bounds, instead of sets of parameters values for growth functions such as the classical Monod or Haldane functions commonly used in bioprocess modeling. We illustrate the applicability of the method with bioreactor simulations in batch and continuous mode, as well as on real data. We also present two extensions of the method adding flexibility in its application, and discuss its efficiency in providing guaranteed state estimations. |
| Tipo: Text |
Palavras-chave: Functional estimation; Interval observers; Growth functions; Least square. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72149/73205.pdf |
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| Fouilland, Eric; Le Floc'H, Emilie; Brennan, Debra; Bell, Elanor M.; Lordsmith, Sian L.; Mcneill, Sharon; Mitchell, Elaine; Brand, Tim D.; Garcia-martin, E. Elena; Leakey, Raymond J. G.. |
| Recent observations in polar marine waters have shown that a large fraction of primary production may be lost to respiration by planktonic bacteria due to very low bacterial growth efficiencies in cold waters. Here we report that sea temperature may be a key factor influencing the interaction between bacteria and primary production in North Atlantic and Arctic waters, suggesting that low primary production rates could not sustain bacterial carbon demand in the coldest Arctic waters. The use of freshly produced phytoplankton exudate by bacteria in early- and mid-summer was assessed, together with the bacterial uptake of dissolved inorganic nitrogen (DIN = nitrate and ammonium), in surface waters along a latitudinal gradient from the North Sea to the Arctic... |
| Tipo: Text |
Palavras-chave: Carbon coupling; Arctic waters; Phytoplankton and bacteria interactions; Nitrogen fluxes. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56417/58087.pdf |
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| Li, Meng; Callier, Myriam; Blancheton, Jean-paul; Galès, Amandine; Nahon, Sarah; Triplet, Sebastien; Geoffroy, Thibault; Menniti, Christophe; Fouilland, Eric; Roque D'Orbcastel, Emmanuelle. |
| Integrated multi-trophic aquaculture (IMTA) systems are a promising solution for sustainable aquaculture combining nutrient recycling with increased biomass production. An innovative land-based recirculating aquaculture system (RAS) was studied in France for a 60-day experiment. It combined a European sea bass (Dicentrarchus labrax) RAS with two other production systems: high rate algal ponds (HRAP) with natural marine polyspecific algal assemblages, and oysters in separate open tanks. The objective was the assessment of: 1) the efficiency and the stability of the microalgae bioremediation of the effluent from a fish RAS in spring and summer, 2) the abundance and the diversity patterns of the microalgae biomass for consumption in the oyster compartment of... |
| Tipo: Text |
Palavras-chave: Microalgae; IMTA; Nutrient bioremediation; Community structure; Oysters. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00480/59207/61900.pdf |
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| Vasseur, Christophe; Bougaran, Gael; Garnier, Matthieu; Hamelin, Jérôme; Leboulanger, Christophe; Le Chevanton, Myriam; Mostajir, Behzad; Sialve, Bruno; Steyer, Jean-philippe; Fouilland, Eric. |
| Association of microalgae culture and anaerobic digestion seems a promising technology for sustainable algal biomass and biogas production. The use of digestates for sustaining the growth of microalgae reduces the costs and the environmental impacts associated with the substantial algal nutrient requirements. A natural marine algae–bacteria consortium was selected by growing on a medium containing macro nutrients (ammonia, phosphate and acetate) specific of a digestate, and was submitted to a factorial experimental design with different levels of temperature, light and pH. The microalgal consortium reached a maximum C conversion efficiency (i.e. ratio between carbon content produced and carbon supplied through light photosynthetic C conversion and acetate)... |
| Tipo: Text |
Palavras-chave: Optimization; Nannochloris; Heterotrophic bacteria; Anaerobic digestion; Bioenergy. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00085/19642/17419.pdf |
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| Cadeau, Pierre; Jézéquel, Didier; Leboulanger, Christophe; Fouilland, Eric; Le Floc’h, Emilie; Chaduteau, Carine; Milesi, Vincent; Guélard, Julia; Sarazin, Gérard; Katz, Amandine; D’amore, Sophie; Bernard, Cecile; Ader, Magali. |
| The Proterozoic Era records two periods of abundant positive carbon isotope excursions (CIEs), conventionally interpreted as resulting from increased organic carbon burial and leading to Earth’s surface oxygenation. As strong spatial variations in the amplitude and duration of these excursions are uncovered, this interpretation is challenged. Here, by studying the carbon cycle in the Dziani Dzaha Lake, we propose that they could be due to regionally variable methane emissions to the atmosphere. This lake presents carbon isotope signatures deviated by ~ + 12‰ compared to the modern ocean and shares a unique combination of analogies with putative Proterozoic lakes, interior seas or restricted epireic seas. A simple box model of its Carbon cycle demonstrates... |
| Tipo: Text |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00656/76784/77944.pdf |
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| Brauer, Verena S.; Stomp, Maayke; Bouvier, Thierry; Fouilland, Eric; Leboulanger, Christophe; Confurius-guns, Veronique; Weissing, Franz J.; Stal, Lucas J.; Huisman, Jef. |
| N-2-fixing cyanobacteria represent a major source of new nitrogen and carbon for marine microbial communities, but little is known about their ecological interactions with associated microbiota. In this study we investigated the interactions between the unicellular N-2-fixing cyanobacterium Cyanothece sp. Miami BG043511 and its associated free-living chemotrophic bacteria at different concentrations of nitrate and dissolved organic carbon and different temperatures. High temperature strongly stimulated the growth of Cyanothece, but had less effect on the growth and community composition of the chemotrophic bacteria. Conversely, nitrate and carbon addition did not significantly increase the abundance of Cyanothece, but strongly affected the abundance and... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00253/36435/73426.pdf |
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| Gales, Amandine; Triplet, Sebastien; Geoffroy, Thibault; Roques, Cécile; Carre, Claire; Le Floc'H, Emilie; Lanfranchi, Mélissa; Simier, Monique; Roque D'Orbcastel, Emmanuelle; Przybyla, Cyrille; Fouilland, Eric. |
| Recently, CO2 recycling for the production of valuable microalgae has acquired substantial interest. Most studies investigating CO2 conversion efficiency in algal cultures were based on single species, although a stabilising effect of algal diversity on biomass production was recently highlighted. However, addition of CO2 into polyalgal cultures requires a careful control of pH; performance of CO2 conversion, growth and carbon biomass production are affected by pH differently, depending on the species of microalgae. This study investigates the efficiency of CO2 conversion by natural marine algal assemblage cultivated in open, land-based raceways (4.5 m3, 10 m2), working as high rate algal ponds (HRAP). Ponds were enriched with nitrogen and phosphate, pure... |
| Tipo: Text |
Palavras-chave: Carbon yield; Microalgal diversity; PH; Predators. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00612/72403/71392.pdf |
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| Krichen, Emna; Rapaport, Alain; Le Floc'H, Emilie; Fouilland, Eric. |
| Positive interactions such as facilitation play an important role during the biological colonization and species succession in harsh or changing environments. However, the direct evidence of such ecological interaction in microbial communities remains rare. Using common freshwater microalgae isolated from a High Rate Algal Pond HRAP treating wastewaters, we investigated with both experimental and modeling approaches the direct facilitation between two algal strains during the colonization phase. Our results demonstrate that the first colonization by microalgae under a severe chemical condition arose from the rapid growth of pioneer species such as Chlorella sorokiniana, which facilitated the subsequent colonization of low growth specialists such as... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00592/70434/68528.pdf |
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| Roque D'Orbcastel, Emmanuelle; Boudin, Elyse; Li, Meng; Carcaillet, Frédérique; Fouilland, Eric. |
| Most older methods of fish farming, or aquaculture, have focused on growing only a single species of sea life, for example, salmon. Modern aquaculture systems involve the cultivation of two or more species together, based on what happens normally in the food chain, so that one species can provide a source of food for another species in the farm. This article describes the results of an experiment combining fish culture with algae culture and oyster culture. We show that algae can grow using fish waste, and oysters can eat algae to produce good-quality, healthy food, which reduces the pollution generated by aquaculture. |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70702/68909.pdf |
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| Sarazin, Gérard; Jezequel, Didier; Leboulanger, Christophe; Fouilland, Eric; Le Floc'H, Emilie; Bouvy, Marc; Gerard, Emmanuelle; Agogué, Hélène; Bernard, Cédric; Hugoni, Mylène; Grossi, Vincent; Trousselier, Marc; Ader, Magali. |
| Dziani Dzaha is a maar the age of which is close to 4000 years. While its water is thought to have originated from seawater it is now considered as an extreme environment due to its hypersaline and alkaline characteristics. Those extreme features have led to the simplification of the trophic network. Cyanobacteria account for up to 95% of the photosynthetic biomass. The main biogeochemical processes, i.e. photosynthesis, bacterial sulfate reduction and methanogenesis could explain the current water composition. As far as we know, this ecosystem could be unique on Earth, extending the nature and chemical limits of aquatic inland ecosystems |
| Tipo: Text |
Palavras-chave: Thalassohaline lake; Endorheic ecosystem; Cyanobacteria; Methane emission; Biogeochemistry; Mayotte. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00667/77948/80128.pdf |
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| Trottet, Aurore; Leboulanger, Christophe; Vidussi, Francesca; Pete, Romain; Bouvy, Marc; Fouilland, Eric. |
| The importance of heterotrophic bacteria relative to phytoplankton in the uptake of ammonium and nitrate was studied in Mediterranean coastal waters (Thau Lagoon) during autumn, when the Mediterranean Sea received the greatest allochthonous nutrient loads. Specific inhibitors and size-fractionation methods were used in combination with isotopic N-15 tracers. NO3 (-) and NH4 (+) uptake was dominated by phytoplankton (60 % on average) during the study period, which included a flood event. Despite lower biomass specific NH4 (+) and NO3 uptake rates, free-living heterotrophic bacteria contributed significantly (> 30 %) to total microbial NH4 (+) and NO3 (-) uptake rates in low chlorophyll waters. Under these conditions, heterotrophic bacteria may be... |
| Tipo: Text |
Palavras-chave: Bacteria; Phytoplankton; Inhibitors; Size fractionation; Nitrogen uptake; Dissolved inorganic nitrogen. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00314/42497/41907.pdf |
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| Galès, Amandine; Bonnafous, Anaïs; Carré, Claire; Jauzein, Vincent; Lanouguère, Elodie; Le Floc'H, Emilie; Pinoit, Joanna; Poullain, Clothilde; Roques, Cécile; Sialve, Bruno; Simier, Monique; Steyer, Jean-philippe; Fouilland, Eric. |
| Several studies focused on wastewater treatment in High Rate Algal Ponds (HRAP) suggest that highly variable climatic conditions cause large variations of microalgal biomass productivity. In the present study, we show that similar carbon, nitrogen and phosphorus removal efficiencies were reached in different HRAPs treating urban wastewaters located in two different temperate (Mediterranean and oceanic) climates. Furthermore, similar ecological successions were observed in these HRAPs. During the start-up phase, the consumption of organic matter by detritivores, already present in the wastewater, appears to be necessary for the microalgae to grow within two weeks in spring. The growth of the rapid-growing species, Chlorella sp., followed by the... |
| Tipo: Text |
Palavras-chave: Microalgae; Predators; Bacteria; Urban effluents; Ammonia and phosphate removal. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00490/60210/63713.pdf |
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| Fouilland, Eric; Gales, Amandine; Beaugelin, Ines; Lanouguere, Elodie; Pringault, Olivier; Leboulanger, Christophe. |
| When microalgae are exposed to contaminants, the role of associated bacteria within the phycosphere, the microenvironment surrounding algal cells, remains largely unknown. The present study investigated the importance of algae-associated bacteria on the responses of microalgae growth to metallic and organic toxicant exposure. The effects of a polluted sediment elutriate, and of metal or pesticide mixtures at environmentally relevant concentrations (<10 μg L−1) were assessed on the growth of two microalgae strains: Isochrysis galbana, a prymnesiophyte, and Thalassiosira delicatula, a centric diatom. Both cultures were maintained as axenic or bacterized under similar conditions in batch cultures. In axenic conditions, the metal mixture addition at low... |
| Tipo: Text |
Palavras-chave: Microbial interactions; Metallic and pesticide contaminants; Sediments. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00453/56422/58325.pdf |
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| Villeger, Sebastien; Fouilland, Eric; Argenty, Jeremy; Bouvier, Corinne; Carre, Claire; Bouvier, Thierry. |
| The productivity of most marine ecosystems is limited by the availability of dissolved nitrogen (N) and phosphorus (P). Nutrient recycling is therefore a key process for ecosystem functioning. Fish recycle nutrients through the excretion of ammonia and phosphate and can influence the abundance and community structure of primary producers such as phytoplankton. However, the effect of fish on other plankton compartments, and whether all fish species have similar effects, is largely unknown. We used a tank experiment to test how 2 Mediterranean fish species, gilthead seabream Sparus aurata and golden mullet Chelon auratus, with distinctly different N and P excretion rates, can affect the abundance and community structure of 3 plankton compartments:... |
| Tipo: Text |
Palavras-chave: Marine fish; Nutrient excretion; Protozooplankton; Phytoplankton; Bacteria. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00584/69659/67585.pdf |
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| Leboulanger, Christophe; Agogue, Helene; Bernard, Cecile; Bouvy, Marc; Carre, Claire; Cellamare, Maria; Duval, Charlotte; Fouilland, Eric; Got, Patrice; Intertaglia, Laurent; Lavergne, Celine; Le Floc'H, Emilie; Roques, Cecile; Sarazin, Gerard. |
| This study describes, for the first time, the water chemistry and microbial diversity in Dziani Dzaha, a tropical crater lake located on Mayotte Island (Comoros archipelago, Western Indian Ocean). The lake water had a high level of dissolved matter and high alkalinity (10.614.5 g L-1 eq. CO32-, i.e. 160220 mM compare to around 22.5 in seawater), with salinity up to 52 psu, 1.5 higher than seawater. Hierarchical clustering discriminated Dziani Dzaha water from other alkaline, saline lakes, highlighting its thalassohaline nature. The phytoplankton biomass was very high, with a total chlorophyll a concentration of 524 to 875 mu g chl a L-1 depending on the survey, homogeneously distributed from surface to bottom (4 m). Throughout the whole water column the... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00625/73731/74808.pdf |
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| Mostajir, Behzad; Roques, Cecile; Bouvier, Corinne; Bouvier, Thierry; Fouilland, Eric; Got, Patrice; Le Floc'H, Emilie; Nouguier, Jean; Mas, Sebastien; Sempere, Richard; Sime-ngando, Telesphore; Troussellier, Marc; Vidussi, Francesca. |
| The impact of fish and oysters on components of the pelagic microbial food web (MFW) was studied in a 10 d mesocosm experiment using Mediterranean coastal waters. Two mesocosms contained natural water only ('Controls'), 2 contained natural water with Crassostrea gigas ('Oyster'), and 2 contained natural water with Atherina spp. ('Fish'). Abundances and biomasses of microorganisms (viruses, bacteria, phytoplankton, heterotrophic flagellates, and ciliates) were measured to estimate their contribution to the total microbial carbon biomass. Two MFW indices, the microbial autotroph: heterotroph C biomass ratio (A:H) structural index and the gross primary production: respiration ratio (GPP:R) functional index, were defined. In the Fish mesocosms, selective... |
| Tipo: Text |
Palavras-chave: Microbial food web; Virioplankton; Bacterioplankton; Phytoplankton; Protozooplankton; Crassostrea; Atherina; Autotrophy; Heterotrophy. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00284/39489/73675.pdf |
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| Alves-de-souza, Catharina; Pecqueur, David; Le Floc'H, Emilie; Mas, Sebastien; Roques, Cecile; Mostajir, Behzad; Vidussi, Franscesca; Velo-suarez, Lourdes; Sourisseau, Marc; Fouilland, Eric; Guillou, Laure. |
| Dinoflagellate blooms are frequently observed under temporary eutrophication of coastal waters after heavy rains. Growth of these opportunistic microalgae is believed to be promoted by sudden input of nutrients and the absence or inefficiency of their natural enemies, such as grazers and parasites. Here, numerical simulations indicate that increasing nutrient availability not only promotes the formation of dinoflagellate blooms but can also stimulate their control by protozoan parasites. Moreover, high abundance of phytoplankton other than dinoflagellate hosts might have a significant dilution effect on the control of dinoflagellate blooms by parasites, either by resource competition with dinoflagellates (thus limiting the number of hosts available for... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00274/38478/36938.pdf |
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| Registros recuperados: 18 | |
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