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Registros recuperados: 30 | |
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Maheswari, Uma; Jabbari, Kamel; Petit, Jean-louis; Porcel, Betina M.; Allen, Andrew E.; Cadoret, Jean-paul; De Martino, Alessandra; Heijde, Marc; Kaas, Raymond; La Roche, Julie; Lopez, P.; Martin-jezequel, Veronique; Meichenin, Agnes; Mock, Thomas; Parker, Micaela Schnitzler; Vardi, Assaf; Armbrust, E. Virginia; Weissenbach, Jean; Katinka, Michael; Bowler, Chris. |
Background: Diatoms represent the predominant group of eukaryotic phytoplankton in the oceans and are responsible for around 20% of global photosynthesis. Two whole genome sequences are now available. Notwithstanding, our knowledge of diatom biology remains limited because only around half of their genes can be ascribed a function based onhomology-based methods. High throughput tools are needed, therefore, to associate functions with diatom-specific genes. Results: We have performed a systematic analysis of 130,000 ESTs derived from Phaeodactylum tricornutum cells grown in 16 different conditions. These include different sources of nitrogen, different concentrations of carbon dioxide, silicate and iron, and abiotic stresses such as low temperature and low... |
Tipo: Text |
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Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00017/12810/9758.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... |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00176/28735/27203.pdf |
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Serive, Benoit; Nicolau, Elodie; Berard, Jean-baptiste; Kaas, Raymond; Pasquet, Virginie; Picot, Laurent; Cadoret, Jean-paul. |
Phytoplankton, with an estimated 30 000 to 1 000 000 species clustered in 12 phyla, presents a high taxonomic and ecophysiological diversity, reflected by the complex distribution of pigments among the different algal classes. High performance liquid chromatography is the gold standard method for qualitative and quantitative analysis of phytoplankton pigments in seawater and culture samples, but only a few pigments can be used as robust chemotaxonomic markers. A major challenge is thus to identify new ones, characteristic of a strain, species, class or taxon that cannot be currently identified on the basis of its pigment signature. Using an optimized extraction process coupled to a HPLC de-replication strategy, we examined the pigment composition of 37... |
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Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00373/48416/48627.pdf |
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Le Chevanton, Myriam; Garnier, Matthieu; Lukomska, Ewa; Schreiber, Nathalie; Cadoret, Jean-paul; Saint-jean, Bruno; Bougaran, Gael. |
Interactions between photosynthetic and non-photosynthetic microorganisms play an essential role in natural aquatic environments and the contribution of bacteria and microalgae to the nitrogen cycle can lead to both competitive and mutualistic relationships. Nitrogen is considered to be, with phosphorus and iron, one of the main limiting nutrients for primary production in the oceans and its availability experiences large temporal and geographical variations. For these reasons, it is important to understand how competitive and mutualistic interactions between photosynthetic and heterotrophic microorganisms are impacted by nitrogen limitation. In a previous study performed in batch cultures, the addition of a selected bacterial strain of Alteromonas sp.... |
Tipo: Text |
Palavras-chave: Interactions; Nitrogen limitation; Microalgae; Bacteria; Chemostat; Dissolved organic matter (DOM); Dunaliella. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00344/45529/45087.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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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... |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28662/27089.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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Pasquet, Virginie; Cherouvrier, Jean-rene; Farhat, Firas; Thiery, Valerie; Piot, Jean-marie; Berard, Jean-baptiste; Kaas, Raymond; Serive, Benoit; Patrice, Thierry; Cadoret, Jean-paul; Picot, Laurent. |
The performance of microwaves irradiation (MAE and VMAE) to extract pigments from two marine microalgae was compared to conventional processes (cold and hot soaking and ultrasound-assisted extraction). Pigments were quantified by RP-HPLC and extraction performance was assessed regarding rapidity, reproducibility and extraction yields. Scanning electron microscopy was used at all extraction steps to assess the impact of the process on microalgal cell integrity. Freeze-drying and pigments extraction preserved microalgae cell integrity (except sonication) and evoked agglutination in superposed cells layers. All processes performed on Dunaliella tertiolecta (chlorophyte) lead to rapid pigments extraction, and equivalent pigments extraction yields, the absence... |
Tipo: Text |
Palavras-chave: Pigments; Microalgae; Microwave; Extraction; Chlorophyll; Fucoxanthin; Carotene; MAE; VMAE. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14059/11533.pdf |
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Bowler, C; Allen, A; Badger, J; Grimwood, J; Jabbari, K; Kuo, A; Maheswari, U; Martens, C; Maumus, F; Otillar, R; Rayko, E; Salamov, A; Vandepoele, K; Beszteri, B; Gruber, A; Heijde, M; Katinka, M; Mock, T; Valentin, K; Verret, F; Berges, J; Brownlee, C; Cadoret, Jean-paul; Chiovitti, A; Choi, C; Coesel, S; De Martino, A; Detter, J; Durkin, C; Falciatore, A; Fournet, J; Haruta, M; Huysman, M; Jenkins, B; Jiroutova, K; Jorgensen, R; Joubert, Y; Kaplan, A; Kroger, N; Kroth, P; La Roche, J; Lindquist, E; Lommer, M; Martin Jezequel, V; Lopez, P; Lucas, S; Mangogna, M; Mcginnis, K; Medlin, L; Montsant, A; Oudot Le Secq, M; Napoli, C; Obornik, M; Parker, M; Petit, J; Porcel, B; Poulsen, N; Robison, M; Rychlewski, L; Rynearson, T; Schmutz, J; Shapiro, H; Siaut, M; Stanley, M; Sussman, M; Taylor, A; Vardi, A; Von Dassow, P; Vyverman, W; Willis, A; Wyrwicz, L; Rokhsar, D; Weissenbach, J; Armbrust, E; Green, B; Van De Peer, Y; Grigoriev Iv,. |
Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one- fifth of the primary productivity on Earth(1,2). The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology(3-5). Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a... |
Tipo: Text |
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Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-4809.pdf |
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Da Costa, Fiz; Le Grand, Fabienne; Quere, Claudie; Bougaran, Gael; Cadoret, Jean-paul; Robert, Rene; Soudant, Philippe. |
Standard and mutant Tisochrysis lutea strains were grown in batch culture for 10 days under nitrogen (N)-replete and N-reduced conditions to determine the effects of N supply in culture medium and growth phase on microalgal physiology and biochemistry. These two T. lutea strains were compared in terms of growth, morphology, associated free-living bacterial community, viability, intracellular lipid content (as measured by Bodipy staining), chlorophyll autofluorescence, and biochemical composition, with a focus on lipid class and fatty acid compositions. The standard strain (T) reached higher cell counts regardless of N supply in culture medium. In both T. lutea strains, microalgal final cell density was significantly lower in N-reduced medium. Carbohydrates... |
Tipo: Text |
Palavras-chave: Tisochrysis lutea; Nitrogen limitation; Growth phase; Flow cytometry; Fatty acids; Lipid classes. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00399/51074/51936.pdf |
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Cadoret, Jean-paul; Garnier, Matthieu; Saint-jean, Bruno. |
Microalgae have been studied for decades, but a new wave of research has recently begun as part of the search for renewable and sustainable energy sources. For economic optimization, microalgal biomass is being considered as a whole (main products and co-products) in an overall 'biorefinery' concept Applications of microalgae cover a broad spectrum, including the food and (livestock) feed industries, bio-energy, cosmetics, healthcare and environmental restoration or protection. In the field of biotechnology, the access to genomic data is playing a growing role. As the cost of sequencing strategies has fallen, studies of gene function at the transcript, protein and biosynthesis pathway levels have multiplied. Notably, sequencing and mass spectrometry... |
Tipo: Text |
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Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00125/23602/21477.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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Garnier, Matthieu; Bougaran, Gael; Pavlovic, Marija; Berard, Jean-baptiste; Carrier, Gregory; Charrier, Aurelie; Le Grand, Fabienne; Lukomska, Ewa; Rouxel, Catherine; Schreiber, Nathalie; Cadoret, Jean-paul; Rogniaux, Helene; Saint-jean, Bruno. |
Haptophytes are a diverse monophyletic group with a worldwide distribution, known to be significantly involved in global climate regulation in their role as a carbon sink. Because nitrogen is a major limiting macronutrient for phytoplankton in oceans and for cultures of microalgae, understanding the involvement of nitrogen availability in haptophyte carbon partitioning is of global and biotechnological importance. Here, we made an ecophysiological study coupled with comprehensive large scale proteomic analysis to examine differences of behavior in reaction to nitrogen availability changes between a wild type strain of Tisochrysis lutea (WTc1) and a mutant strain (2Xc1) known to accumulate more storage lipids. Strains were grown in chemostats and studied... |
Tipo: Text |
Palavras-chave: Algae; Isochrysis; Lipids; Nitrogen; Reverse genomic: proteomic. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00356/46702/46904.pdf |
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Baudelet, Paul-hubert; Gagez, Anne-laure; Berard, Jean-baptiste; Juin, Camille; Bridiau, Nicolas; Kaas, Raymond; Thiery, Valerie; Cadoret, Jean-paul; Picot, Laurent. |
The glaucophyte Cyanophora paradoxa (Cp) was chemically investigated to identify pigments efficiently inhibiting malignant melanoma, mammary carcinoma and lung adenocarcinoma cells growth. Cp water and ethanol extracts significantly inhibited the growth of the three cancer cell lines in vitro, at 100 mu g.mL(-1). Flash chromatography of the Cp ethanol extract, devoid of c-phycocyanin and allophycocyanin, enabled the collection of eight fractions, four of which strongly inhibited cancer cells growth at 100 mu g.mL(-1). Particularly, two fractions inhibited more than 90% of the melanoma cells growth, one inducing apoptosis in the three cancer cells lines. The detailed analysis of Cp pigment composition resulted in the discrimination of 17 molecules, ten of... |
Tipo: Text |
Palavras-chave: Pigments; Microalgae; Cyanophora paradoxa; Melanoma; Cancer; Apoptosis; Zeaxanthin; Cryptoxanthin. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00177/28818/27289.pdf |
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Pasquet, Virginie; Morisset, Perrine; Ihammouine, Said; Chepied, Amandine; Aumailley, Lucie; Berard, Jean-baptiste; Serive, Benoit; Kaas, Raymond; Lanneluc, Isabelle; Thiery, Valerie; Lafferriere, Mathieu; Piot, Jean-marie; Patrice, Thierry; Cadoret, Jean-paul; Picot, Laurent. |
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT dichloromethane extract exhibited a strong anti-proliferative activity on MCF-7 and LNCaP cells, and was further fractionated and sub-fractionated by RP-HPLC. High resolution mass spectrometry and spectrophotometric analysis unequivocally identified violaxanthin as the most antiproliferative molecule present in DT DCM extract. Violaxanthin purified from DT induced MCF-7 dose- dependent growth inhibition in continuous and discontinuous treatments, at... |
Tipo: Text |
Palavras-chave: Pigments; Microalgae; Dunaliella; Violaxanthin; Carotenoid; Cancer; Apoptosis. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00040/15142/12575.pdf |
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Thiriet-rupert, Stanislas; Carrier, Gregory; Chenais, Benoit; Trottier, Camille; Bougaran, Gael; Cadoret, Jean-paul; Schoefs, Benoit; Saint-jean, Bruno. |
Background: Studying transcription factors, which are some of the key players in gene expression, is of outstanding interest for the investigation of the evolutionary history of organisms through lineage-specific features. In this study we performed the first genome-wide TF identification and comparison between haptophytes and other algal lineages. Results: For TF identification and classification, we created a comprehensive pipeline using a combination of BLAST, HMMER and InterProScan software. The accuracy evaluation of the pipeline shows its applicability for every alga, plant and cyanobacterium, with very good PPV and sensitivity. This pipeline allowed us to identify and classified the transcription factor complement of the three haptophytes... |
Tipo: Text |
Palavras-chave: Algae; Endosymbiotic gene transfer; Haptophytes; Prediction pipeline; Stramenopiles; Tisochrysis lutea; Transcription factors. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00333/44403/44072.pdf |
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Montagne, Xavier; Porot, Pierre; Aymard, Caroline; Querleu, Cecile; Bouter, Anne; Lorne, Daphne; Cadoret, Jean-paul; Lombaert-valot, Isabelle; Petillon, Odile. |
A strong interest has been focused from several years on the algae pathway for energy production, especially for transportation fuels called third generation biofuel or G3 biofuel, and mainly from microalgae route, considering it could be a high potential alternative strategy for renewable energy and fuel production. Algae, and especially microalgae, present significant advantages compared with land resources, such as much higher productivity and lack of competition with food applications. Nevertheless, based on current knowledge, the production of an algae biomass for energy remains a difficult target to reach, due to the numerous existing hurdles such as the energetic yield and the economic positioning, without neglecting the environmental and societal... |
Tipo: Text |
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Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00174/28565/26941.pdf |
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Registros recuperados: 30 | |
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