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| Registros recuperados: 38 | |
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| Bougaran, Gael; Le Dean, Loic; Loizel, Céline; Lukomska, Ewa; Picquet, Marie-lise; Kaas, Raymond; Muller-feuga, Arnaud. |
| La prymnésiophycée Isochrysis galbana affinis Tahiti (T -iso) est classiquement utilisée comme nourriture de larves de mollusques et de proies vivantes de poissons d'aquaculture dans la plupart des écloseries produisant des juvéniles de ces espèces. La solution d'enrichissement de Conway (SEC), élaborée en 1966 par Walne, est largement utilisée pour la production de T -iso en batch. Cependant, les apports nutritifs de cette solution d'enrichissement ne sont pas spécifiquement optimisés pour la culture de cette algue, participant à engendrer des coûts de production élevés (Valenzuala-Espinoza et al., 1999 ; Fabregas et al., 1986) et des effluents inépuisés. Dans les 15 dernières années, plusieurs auteurs sont parvenus à réduire le coût de solutions... |
| Tipo: Text |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00304/41519/40727.pdf |
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| Bougaran, Gael; Le Dean, Loic; Lukomska, Ewa; Picquet, Marie-lise; Kaas, Raymond; Muller-feuga, Arnaud. |
| La prymnésiophycée Isochrysis galbana affinis Tahiti (T -iso) est une micro algue marine classiquement utilisée comme nourriture de larves de mollusques et de proies vivantes de poissons d'aquaculture dans la plupart des écloseries produisant des juvéniles de ces espèces. Aujourd'hui, de nombreuses écloseries de mollusques et de poissons l'utilisent en association avec d'autres espèces telles que Pavlova lutheri, Chaetoceros calcitrans et Skeletonema costatum. Isolée à Tahiti par JL Martin en 1975 (comm. pers.), cette algue s'est rapidement imposée dans la nutrition larvaire des crevettes et des mollusques en raison de sa croissance rapide en conditions tropicales et de ses qualités nutritionnelles, en relation avec sa forte teneur en acides gras... |
| Tipo: Text |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00304/41508/40716.pdf |
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| Bougaran, Gael; Le Dean, Loic; Lukomska, Ewa; Kaas, Raymond; Baron, Regis. |
| Starting microalgae continuous culture generally includes a preliminary batch culture to obtain sufficient cell density. It is possible to apply continuous regime from the beginning of the culture (IC mode) rather than to begin by an initial batch (IB mode). It is our purpose to check that both initial modes lead to identical steady-state cell characteristics. The microalga Isochrysis galbana affinis Tahiti was used for this comparative study. With an initial cell density of 5 x 10(5) cell ml(-1) and a dilution rate of about 1.0 d(-1), both IB and IC modes led to identical cell density once steady-state is reached between 6 and 8 d after inoculation in the two cases. Cell concentration of chlorophyll a and pheopigment a were found to be similar for IB and... |
| Tipo: Text |
Palavras-chave: Isochrysis; Cell quota; Photosynthesis; Steady state; Continuous culture. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-597.pdf |
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| Angeri, S.; Bougaran, Gael; Connan, Jean-paul; Jouin, Jean-claude; Kaas, Raymond; Le Dean, Loic; Legrand, J.; Loubiere, K.; Lukomska, Ewa; Olivo, Erell; Picquet, Marie-lise; Pruvost, J.; Robert, Rene. |
| Les travaux présentés dans le cadre de ce rapport d'activité rendent compte des avancées réalisées sur le plan (1) biologique, avec d'une part une étude sur le comportement du genre Chaetoceros en culture continue et, d'autre part, les résultats d'expérimentations sur les performances d'élevages larvaires réalisés sur la base de cultures de microalgues en continu, et (2) technologique, avec la continuité des actions de développement du photobioréacteur destiné aux écloseries commerciales ainsi que des périphériques indispensables à son intégration dans le secteur aquacole. |
| Tipo: Text |
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| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00304/41518/40726.pdf |
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| Bougaran, Gael; Bernard, Olivier; Sciandra, Antoine. |
| It is well documented that the combination of low nitrogen and phosphorus resources can lead to situations where colimitation of phytoplankton growth arises, yet the underlying mechanisms are not fully understood. Here, we propose a Droop-based model built on the idea that colimitation by nitrogen and phosphorus arises from the uptake of nitrogen. Indeed, since N-porters are active systems, they require energy that could be related to the phosphorus status of the cell. Therefore, we assumed that N uptake is enhanced by the P quota. Our model also accounts for the biological observations that uptake of a nutrient can be down-regulated by its own internal quota, and succeeds in describing the strong contrast for the non-limiting quotas under N-limited and... |
| Tipo: Text |
Palavras-chave: Colimitation; Phytoplankton; Mathematical model; Quota. |
| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00011/12216/9060.pdf |
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| Mimouni, Virginie; Ulmann, Lionel; Pasquet, Virginie; Mathieu, Marie; Picot, Laurent; Bougaran, Gael; Cadoret, Jean-paul; Morant-manceau, Annick; Schoefs, Benoit. |
| Through the photosynthetic activity, microalgae process more than 25% of annual inorganic carbon dissolved in oceans into carbohydrates that ultimately, serve to feed the other levels of the trophic networks. Besides, microalgae synthesize bioactive molecules such as pigments and lipids that exhibit health properties. In addition, abiotic stresses, such as high irradiance, nutrient starvation, UV irradiation, trigger metabolic reorientations ending with the production of other bioactive compounds such as omega-3 fatty acids or carotenoids. Traditionally, these compounds are acquired through the dietary alimentation. The increasing, and often unsatisfied, demand for compounds from natural sources, combined with the decrease of the halieutic resources,... |
| Tipo: Text |
Palavras-chave: Bioactive compound; Alga; Pigment; Lipid; Health benefit; Abiotic stress; Metabolic reorientation; Diatom. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00118/22894/20847.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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| Marchetti, Julie; Bougaran, Gael; Le Dean, Loic; Megrier, Cyril; Lukomska, Ewa; Kaas, Raymond; Olivo, Erell; Baron, Regis; Robert, Rene; Cadoret, Jean-paul. |
| Optimal culture conditions were investigated for the continuous culture of Isochrysis affinis galbana (T-Iso) by assessing the effects of irradiance, temperature, pH and nitrogen and phosphorus requirements. Assessment of the growth rate-irradiance relationship in a turbidostat experiment highlighted that an optimum irradiance efficiency for growth (E-mu) occurred at irradiance much lower than the saturating level. Furthermore, our modeling approach for productivity pointed out that an optimal set of irradiance and dilution rate could be achieved in order to maximize irradiance efficiency. Optimal conditions for growth were assessed for temperature, pH and irradiance by means of a factorial design experiment. The resulting model predicted that optimal... |
| Tipo: Text |
Palavras-chave: Isochrysis affinis galbana; Irradiance efficiency; Factor interaction; Nutrient limitation; Microalgae cultures. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00076/18736/16465.pdf |
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| Bougaran, Gael; Rouxel, Catherine; Dubois, Nolwenn; Kaas, Raymond; Grouas, Sophie; Lukomska, Ewa; Le Coz, Jean-rene; Cadoret, Jean-paul. |
| Microalgae offer a high potential for energetic lipid storage as well as high growth rates. They are therefore considered promising candidates for biofuel production, with the selection of high lipid-producing strains a major objective in projects on the development of this technology. We developed a mutation-selection method aimed at increasing microalgae neutral lipid productivity. A two step method, based on UVc irradiation followed by flow cytometry selection, was applied to a set of strains that had an initial high lipid content and improvement was assessed by means of Nile-red fluorescence measurements. The method was first tested on Isochrysis affinis galbana (T-Iso). (...) |
| Tipo: Text |
Palavras-chave: Strain selection; Isochrysis; Neutral lipid; Ultra violet; Flux cytometry; Biofuel. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00085/19643/17418.pdf |
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| Marchetti, Julie; Bougaran, Gael; Jauffrais, Thierry; Lefebvre, Sebastien; Rouxel, Catherine; Saint-jean, Bruno; Lukomska, Ewa; Robert, Rene; Cadoret, Jean-paul. |
| In aquaculture, particularly in bivalve hatcheries, the biochemical composition of algal diets has a strong influence on larval and post-larval development. Biochemical composition is known to be related to culture conditions, among which light represents a major source of variation. The effects of blue light on biochemical composition and photosynthetic rate of Isochrysis sp. (T-iso) CCAP 927/14 were assessed in chemostat at a single irradiance (300 μmol photons m−2 s−1) and compared with white light. Two different dilution (renewal) rates were also tested: 0.7 and 0.2 d−1. Relative carbohydrate content was lower under blue light than under white light at both dilution rates, whereas chlorophyll a and photosynthesis activity were higher. In contrast,... |
| Tipo: Text |
Palavras-chave: Isochrysis; Blue light; Photosynthesis; Proximate composition; Chemostat. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00085/19599/17237.pdf |
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| Le Chevanton, Myriam; Garnier, Matthieu; Bougaran, Gael; Schreiber, Nathalie; Lukomska, Ewa; Berard, Jean-baptiste; Fouilland, E.; Bernard, Olivier; Cadoret, Jean-paul. |
| Previous studies have demonstrated that bacteria influence microalgal metabolism, suggesting that the selection and characterization of growth-promoting bacteria should offer a new strategy for improving industrial algal cultivation. In the present study, 48 cultivable bacteria were isolated from marine microalgae species and identified using 16S rRNA phylogenetic analysis. The recovered bacteria were found to be members of the α- and γ-Proteobacteria, Cytophaga–Flavobacterium–Bacteroides (CFB) and gram-positive monophyletic clusters. To address the effect of these bacteria on the growth of Dunaliella sp. individually, an experimental high-throughput tool was developed to simultaneously compare replicated associations. A two-step approach was used to... |
| Tipo: Text |
Palavras-chave: Microalgae; Dunaliella; Bacteria; Interaction; Bacterial diversity. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00142/25334/24768.pdf |
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| Garnier, Matthieu; Carrier, Gregory; Rogniaux, Helene; Nicolau, Elodie; Bougaran, Gael; Saint-jean, Bruno; Cadoret, Jean-paul. |
| Microalgae are photosynthetic microorganisms that have an extraordinary diversity which biotechnological potential is just beginning to be explored. Microalgae in biotechnology are presently the focus of an unprecedented surge in interest and investment worldwide. Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for feedstocks, food and biofuel production. Although studies have been performed in model species, to this day it is critical to understand through particular mechanisms of biotechnological species. Tisochrysis lutea is traditionally used for aquaculture feed and presents advantages for lipid production. The wild type strain and a lipid over-accumulating selected mutant were used to perform the first... |
| Tipo: Text |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28735/27203.pdf |
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| Bougaran, Gael. |
| Interactions between nitrogen (N) and phosphorus (P) on the growth of phytoplankton are not fully elucidated. Here, we propose the hypothesis that, since phosphorus plays a central role in energy, it can control the active transport of NO3. Our model for N-P co-limitation provides an asymmetric structure which reflects the respective roles of both nutrients and the differences in the control of absorption. The model succeeds in describing the different trends observed for N and P cell content in data sets taken from the literature. We further conducted experiments in batch and chemostat under different N: P ratios. Our results highlighted that P-limited cells were characterized by a low content of ATP and a low net absorption of NO3. When PO4 was... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00293/40397/38912.pdf |
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| Garnier, Matthieu; Carrier, Gregory; Rogniaux, Helene; Nicolau, Elodie; Bougaran, Gael; Saint-jean, Bruno; Cadoret, Jean-paul. |
| Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for biomass feedstock, food and biofuel production. Using a domesticated oleaginous algae Tisochrysis lutea, we performed the first comparative proteomic analysis on the wild type strain and a selected lipid over-accumulating mutant. 2-DE analysis was made on these strains cultured in two metabolic conditions, with and without nitrogen deprivation, which revealed significant differences in proteomes according to both strain and nitrogen availability. Mass spectrometry allowed us to identify 37 proteins that were differentially expressed between the two strains, and 17 proteins regulated by nitrogen starvation concomitantly with lipid accumulation. The proteins... |
| Tipo: Text |
Palavras-chave: Microalgae; Biotechnology; Lipid; Nitrogen; Proteomic; Selection. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00179/29012/27470.pdf |
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| Bougaran, Gael; Saint-jean, Bruno. |
| Pour nos sociétés modernes, en quête de nouveaux procédés et de molécules actives innovantes, les microalgues représentent un formidable potentiel. Leurs nombreuses espèces et leur biodiversité constituent un réservoir de métabolites et de propriétés biochimiques quasi-inexploré, pour le développement de nouvelles applications biotechnologiques. |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00252/36321/34885.pdf |
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| Carrier, Gregory; Garnier, Matthieu; Le Cunff, Loic; Bougaran, Gael; Probert, Ian; De Vargas, Colomban; Corre, E; Cadoret, Jean-paul; Saint-jean, Bruno. |
| The applied exploitation of microalgae cultures has to date almost exclusively involved the use of wild type strains, deposited over decades in dedicated culture collections. Concomitantly, the concept of improving algae with selection programs for particular specific purposes is slowly emerging. Studying since a decade an economically and ecologically important haptophyte Tisochrysis lutea (Tiso), we took advantage of the availability of wild type (Tiso-Wt) and selected (Tiso-S2M2) strains to conduct a molecular variations study. This endeavour presented substantial challenges: the genome assembly was not yet available, the life cycle unknown and genetic diversity of Tiso-Wt poorly documented. This study brings the first molecular data in order to set up... |
| Tipo: Text |
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| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28662/27089.pdf |
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| Rumin, Judith; Bonnefond, Hubert; Saint-jean, Bruno; Rouxel, Catherine; Sciandra, Antoine; Bernard, Olivier; Cadoret, Jean-paul; Bougaran, Gael. |
| Microalgae are currently emerging as one of the most promising alternative sources for the next generation of food, feed, cosmetics and renewable energy in the form of biofuel. Microalgae constitute a diverse group of microorganisms with advantages like fast and efficient growth. In addition, they do not compete for arable land and offer very high lipid yield potential. Major challenges for the development of this resource are to select lipid-rich strains using high-throughput staining for neutral lipid content in microalgae species. For this purpose, the fluorescent dyes most commonly used to quantify lipids are Nile red and BODIPY 505/515. Their fluorescent staining for lipids offers a rapid and inexpensive analysis tool to measure neutral lipid content,... |
| Tipo: Text |
Palavras-chave: Nile red; BODIPY 505/515; Microalgae; Neutral lipid; Fluorescence; Biodiesel. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00257/36823/35451.pdf |
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| Registros recuperados: 38 | |
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