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A New Process for Extracting Alginates from Laminaria digitata: Reactive Extrusion ArchiMer
Vauchel, Peggy; Kaas, Raymond; Arhaliass, Abdellah; Baron, Regis; Legrand, Julien.
Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The main step in the extraction protocol used in the alginate industry is that of alkaline extraction. A batch process is used for this step, which is time-, water-, and reactant-consuming. The possibility of extracting by reactive extrusion was investigated. The reactive extrusion process appeared to be more efficient than the batch process for the alkaline extraction of alginates from Laminaria digitata in several key ways: Time demand is reduced from about an hour to only few minutes, water and reactant requirements are divided by more than a factor 2, extraction yield is 15% higher (relative enhancement), and the rheological...
Tipo: Text Palavras-chave: Intrinsic viscosity; Reactive extrusion; Laminaria digitata; Alkaline extraction; Alginate.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-6255.pdf
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Amélioration des productions phytoplanctoniques en écloserie de mollusques : caractérisation des microalgues fourrage ArchiMer
Robert, Rene; Chretiennot-dinet, Marie-josèphe; Kaas, Raymond; Martin-jezequel, Véronique; Moal, Jeanne; Le Coz, Jean-rene; Nicolas, Jean-louis; Bernard, Eudes; Connan, Jean-paul; Le Dean, Loic; Le Gourrierec, Gaetane; Leroy, Bertrand; Quere, Claudie.
in mollusc hatcheries. Consequently, we assessed themost commonly used species to establish their growth and size profiles, their cytomorphological, biochemical, biomolecular identification as well as their cytometer signs, and also their ability to grow under extreme conditions of temperature and salinity. This work aimed at matching the conformity of the strains used in Argenton (dispatched to most of the French commercial hatcheries) to those of a referenced culture collection. A previous screening preceded this study, because of the 45 species and/or clones held originally, Argenton kept no more than 15 species. As most of the latter are also represented in referenced collection, our strains are therefore correctly identified. On the other hand, the...
Tipo: Text Palavras-chave: Ecological limits; Biomolecular profile; Flow cytometry; Biochemical composition; Cytomorphology; Phytoplankton; Mollusc; Hatchery; Ecotolérance; Profil biomoléculaire; Cytométrie en flux; Composition biochimique; Cytomorphologie; Phytoplancton; Mollusques; Ecloserie.
Ano: 2004 URL: http://archimer.ifremer.fr/doc/2004/rapport-1546.pdf
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Antiproliferative Activity of Cyanophora paradoxa Pigments in Melanoma, Breast and Lung Cancer Cells ArchiMer
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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Antiproliferative Activity of Violaxanthin Isolated from Bioguided Fractionation of Dunaliella tertiolecta Extracts ArchiMer
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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Community analysis of pigment patterns from 37 microalgae strains reveals new carotenoids and porphyrins characteristic of distinct strains and taxonomic groups ArchiMer
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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Culture en continu de Isochrysis galbana affinis Tahiti ArchiMer
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...
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Ano: 2001 URL: http://archimer.ifremer.fr/doc/00304/41508/40716.pdf
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Decrease in dynamic viscosity and average molecular weight of alginate from Laminaria digitata during alkaline extraction ArchiMer
Vauchel, Peggy; Arhaliass, Abdellah; Legrand, Jack; Kaas, Raymond; Baron, Regis.
Alginates are natural polysaccharides that are extracted from brown seaweeds and widely used for their rheological properties. The central step in the extraction protocol used in the alginate industry is the alkaline extraction, which requires several hours. In this study, a significant decrease in alginate dynamic viscosity was observed after 2 h of alkaline treatment. Intrinsic viscosity and average molecular weight of alginates from alkaline extractions 1-4 h in duration were determined, indicating depolymerization of alginates: average molecular weight decreased significantly during the extraction, falling by a factor of 5 between 1 and 4 h of extraction. These results suggested that reducing extraction time could enable preserving the rheological...
Tipo: Text Palavras-chave: Laminaria digitata; Intrinsic viscosity; Depolymerization; Average molecular weight; Alkaline extraction; Alginate.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-4060.pdf
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Digital expression profiling of novel diatom transcripts provides insight into their biological functions ArchiMer
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...
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Ano: 2010 URL: http://archimer.ifremer.fr/doc/00017/12810/9758.pdf
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Dynamical modelling of a reactive extrusion process: Focus on residence time distribution in a fully intermeshing co-rotating twin-screw extruder and application to an alginate extraction process ArchiMer
Baron, Regis; Vauchel, Peggy; Kaas, Raymond; Arhaliass, Abdellah; Legrand, Jack.
The context of this study is the modelling of reactive extrusion process based on an alginate extraction protocol. Residence Time Distribution (RTD) is one important part to predict the kinetics of reactive compounds. A simple model is proposed to predict RTD in fully intermeshing co-rotating twin-screw extruders without reaction. This model, which can be easily extended to reactive case in a future work, is based on the extension of an axial dispersion model, including control parameters (screw speed and flow rate) and geometrical parameters (screw profile and die design). Simulations were performed for various operating and geometrical conditions so as to illustrate possibilities offered by the proposed model. Validation was conducted for two different...
Tipo: Text Palavras-chave: Alginate; Extraction; Extrusion; Mathematical modelling; Residence time distribution; Simulation; Laminaria digitata.
Ano: 2010 URL: http://archimer.ifremer.fr/doc/00005/11592/8985.pdf
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Elements for optimizing a one-step enzymatic bio-refinery process of shrimp cuticles: Focus on enzymatic proteolysis screening ArchiMer
Baron, Regis; Socol, Marius; Kaas, Raymond; Arhaliass, A.; Rodriguez Del Pino, J.; Le Roux, Karine; Donnay-moreno, Claire; Berge, Jean-pascal.
This article complements an earlier work published in 2015 Baron et al. (2015) that showed the interest of a shrimp shells bio-refining process. We compare here the effect of eleven commercial proteases at pH 3.5 or 4.0 on a residual amount of shrimp shells proteins after 6 hours at 50 °C. The two pH are obtained when respectively 40 and 25 mmol of formic acid are added to 5 g of mild dried shell. Deproteinisation yield above 95% are obtained. Residual amino acids profile in the solid phase was identical for the eleven proteases except for pepsin which was similar to the raw material profile. A significant relative increase in the proportion of Glycine is observed for the ten other cases. Likewise, shapes of size exclusion chromatograms of the dissolved...
Tipo: Text Palavras-chave: Bio-refinery; Shrimp cuticles; Acidic enzymatic proteolysis.
Ano: 2017 URL: https://archimer.ifremer.fr/doc/00388/49957/50530.pdf
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Emergence d'une filière de culture de macro-algues en Bretagne et problème relatif à une espèce non indigène, le wakame (Undaria pinnatifida) ArchiMer
Antoine, Loic; Lemoine, Maud; Boulben, Sylviane; Kaas, Raymond; Laurans, Martial; Viard, Frédérique; Potin, Philippe.
La synthèse de l’expertise collégiale menée par l’Ifremer et la station biologique de Roscoff permet de préconiser le maintien des cultures de Undaria pinnatifida dans les zones déjà mises en culture à condition de se cantonner aux pratiques culturales des exploitants installés depuis longtemps, avec un suivi et sans expérimenter de nouvelles pratiques pour lesquelles il n’y a pas de recul. Là où des essais ont eu lieu en 2010 et 2011 (Projet Chaco), il serait nécessaire de faire rapidement un état des lieux de la présence ou l'absence d'Undaria pinnatifida en milieu naturel afin de mesurer l'impact de ces essais. En l’état actuel des connaissances il n’y a pas de données scientifiques qui permettent de garantir le respect de l’article 24 du R(CE) N°...
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Ano: 2012 URL: http://archimer.ifremer.fr/doc/00086/19740/17380.pdf
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Enhancement of neutral lipid productivity in the microalga Isochrysis affinis Galbana (T-Iso) by a mutation-selection procedure ArchiMer
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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Essai de cryoconservation des gamétophytes de l'algue alimentaire Undaria pinnatifida (Laminariale) ArchiMer
Arbault, Suzanne; Renard, Philippe; Pérez, Rene; Kaas, Raymond.
Low temperature tolerance was determined for gametophytes of food alga Undaria pinnatifida according to various cryopreservation methods. Survival durations after storage in a medium containing 28% glycerol at −80 °C or in a 5-10% glycerol solution at −196 °C were only 9 and 4 days respectively. On the other hand, cooling at 5 °C/min. and storage at −15 °C for 15 minutes, without cryoprotective medium, did not reduce viability but this was highly decreased by storage for 15 minutes at −30 or −196 °C, with or without DMSO. The morphological cooling injuries were depigmentation and/or a contraction of the cells.
Tipo: Text Palavras-chave: Algue; Cryoconservation; Gamétophyte; Undaria pinnatifida; Alga; Cryopreservation; Gametophyte; Undaria pinnatifida.
Ano: 1990 URL: http://archimer.ifremer.fr/doc/00189/30071/28559.pdf
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How haptophytes microalgae mitigate vitamin B-12 limitation ArchiMer
Nef, Charlotte; Jung, Sebastien; Mairet, Francis; Kaas, Raymond; Grizeau, Dominique; Garnier, Matthieu.
Vitamin B-12 (cobalamin) can control phytoplankton development and community composition, with around half of microalgal species requiring this vitamin for growth. B-12 dependency is determined by the absence of cobalamin-independent methionine synthase and is unrelated across lineages. Despite their important role in carbon and sulphur biogeochemistry, little is known about haptophytes utilization of vitamin B-12 and their ability to cope with its limitation. Here we report the first evaluation of B-12 auxotrophy among this lineage based on molecular data of 19 species from 9 families. We assume that all species encode only a B-12-dependent methionine synthase, suggesting ubiquitous B-12 auxotrophy in this phylum. We further address the effect of...
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00504/61523/65398.pdf
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Kinetic study of solid phase demineralization by weak acids in one-step enzymatic bio-refinery of shrimp cuticles ArchiMer
Baron, Regis; Socol, Marius; Arhaliass, A.; Bruzac, Sandrine; Le Roux, Karine; Del Pino, J. Rodriguez; Berge, Jean-pascal; Kaas, Raymond.
We describe a one-step bio-refinery process for shrimp composites by-products. Its originality lies in a simple rapid (6 h) biotechnological cuticle fragmentation process that recovers all major compounds (chitins, peptides and minerals in particular calcium). The process consists of a controlled exogenous enzymatic proteolysis in a food-grade acidic medium allowing chitin purification (solid phase), and recovery of peptides and minerals (liquid phase). At a pH of between 3.5 and 4, protease activity is effective, and peptides are preserved. Solid phase demineralization kinetics were followed for phosphoric, hydrochloric, acetic, formic and citric acids with pKa ranging from 2.1 to 4.76. Formic acid met the initial aim of (i) 99 % of demineralization yield...
Tipo: Text Palavras-chave: Bio-refinery; Acidic enzymatic proteolysis; Shrimp cuticles; Demineralization kinetics and modeling.
Ano: 2015 URL: http://archimer.ifremer.fr/doc/00281/39244/37809.pdf
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Kinetics modeling of alginate alkaline extraction from Laminaria digitata ArchiMer
Vauchel, Peggy; Le Roux, Karine; Kaas, Raymond; Arhaliass, Abdellah; Baron, Regis; Legrand, Jack.
Alginates being depolymerized during their alkaline extraction, reducing extraction time could help producing higher rheological quality alginates. The purpose of the present work is to study fresh Laminaria digitata destructuration during alkaline extraction and its link to extraction kinetics. Both alginate extraction yield and mean diameter of algae particles were followed for different values of agitation level and initial size of algae pieces. Results highlighted the existence of a link between extraction yield and algal destructuration. Those elements and the specificity of L. digitata structure have been taken into account to propose a kinetics model based on a fluid-particle reaction with decreasing size particles. The model parameters have been...
Tipo: Text Palavras-chave: Model; Laminaria digitata; Alkaline extraction kinetics; Alginate.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6315.pdf
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La culture des algues marines dans le monde ArchiMer
Perez, René; Kaas, Raymond; Campello, Francois; Arbault, Suzanne; Barbaroux, Olivier.
Shouldn't Earth, the human planet, be called the algae planet? First appearing 3.5 billion years ago, algae have always been objective allies of life and humans. Brought about by algae, oxygen and the ozone layer allowed plant and animal life to develop in oceans and on continents. They offer spawning grounds and feeding grounds for marine fauna....
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Ano: 1992 URL: http://archimer.ifremer.fr/doc/1992/rapport-4402.pdf
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L'échouement de l'Amoco Cadiz : conséquences sur les peuplements algaux des côtes bretonnes ArchiMer
Kaas, Raymond.
Les 300 km du littoral breton touchés par les hydrocarbures de l'Amoco Cadiz sont parmi les plus productifs quant à l'exploitation des algues. L'ISTPM a suivi l'évolution des peuplements de Laminaria digitata et de Chondrus crispus, algues les plus utilisées par les industries locale et fait état des perturbations physiologiques engendrées par la pollution par les hydrocarbures.
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Ano: 1980 URL: https://archimer.ifremer.fr/doc/00593/70502/68653.pdf
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Les consequences de l'echouement de l'Amoco Cadiz" sur les peuplements algaux exploitables ArchiMer
Kaas, Raymond.
Introduction. The amount of hydrocarbons dumped into the sea is currently estimated at 6 to 16 million tons per year. This pollution comes from various sources: Chronic discharges associated with human activity such as oil tanker deballasting or discharges from coastal petroleum processing facilities; natural chronic discharges; accidental discharges like leaks coming from drilling well heads or oil tanker accidents. Natural spills happen, in general, in a relatively unobtrusive way and their effects are quickly diminished by significant dilution and rapid degradation of the various components. Oil spills, however, are characterised by a massive and occasional supply of hydrocarbons. The "Amoco Cadiz" shipwreck fits in with this last case and has seemed...
Tipo: Text Palavras-chave: Seaweeds; Pollution Effects; Marine Pollution; Oil Spill.
Ano: 1980 URL: http://archimer.ifremer.fr/doc/1980/publication-1950.pdf
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Microwave-assisted extraction of phycobiliproteins from Porphyridium purpureum ArchiMer
Juin, Camille; Cherouvrier, Jean-rene; Thiery, Valerie; Gagez, Anne-laure; Berard, Jean-baptiste; Joguet, Nicolas; Kaas, Raymond; Cadoret, Jean-paul; Picot, Laurent.
In the present study, microwave-assisted extraction was first employed to extract the phycobiliproteins of Porphyridium purpureum (Pp). Freeze-dried Pp cells were subjected to microwave-assisted extraction (MAE) to extract phycoerythin (PE), phycocyanin (PC), and allophycocyanin (APC). MAE combined reproducibility and high extraction yields and allowed a 180- to 1,080-fold reduction of the extraction time compared to a conventional soaking process. The maximal PE extraction yield was obtained after 10-s MAE at 40 A degrees C, and PE was thermally damaged at temperatures higher than 40 A degrees C. In contrast, a flash irradiation for 10 s at 100 A degrees C was the best process to efficiently extract PC and APC, as it combined a high temperature necessary...
Tipo: Text Palavras-chave: Allophycocyanin; MAE; Microalgae; Microwave; Phycobiliprotein; Phycocyanin; Phycoerythrin; Porphyridium; Thylakoid.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00253/36439/35169.pdf
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