26 results on '"Ratiskol, J."'
Search Results
2. Free-radical depolymerization with metallic catalysts of an exopolysaccharide produced by a bacterium isolated from a deep-sea hydrothermal vent polychaete annelid
- Author
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Petit, A.-C., Noiret, N., Sinquin, C., Ratiskol, J., Guézennec, J., and Colliec-Jouault, S.
- Published
- 2006
- Full Text
- View/download PDF
3. Polysaccharide labelling: impact on structural and biological properties
- Author
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Roger, O, Colliec-Jouault, S, Ratiskol, J, Sinquin, C, Guezennec, J, Fischer, A.M, and Chevolot, L
- Published
- 2002
- Full Text
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4. Biofunctional microassemblies on an exopolysaccharide produced by a deep sea hydrothermal bacterium for tissue engineering applications
- Author
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Zykwinska, Agata, Marquis, Mélanie, Davy, Joëlle, Sinquin, C., Ratiskol, J., Cuenot, S., Renard, Denis, Colliec-Jouault, S., Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER). Nantes, FRA., and ProdInra, Migration
- Subjects
[SDV.IB.BIO] Life Sciences [q-bio]/Bioengineering/Biomaterials ,Biopolymer ,Microfluidic ,[SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics ,[SDV.IB.BIO]Life Sciences [q-bio]/Bioengineering/Biomaterials ,ComputingMilieux_MISCELLANEOUS - Abstract
National audience
- Published
- 2014
5. Bioinformatic analysis of the Vibrio diabolicus genome for an exopolysaccharide biosynthesis locus
- Author
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Boursicot, V., primary, LaPointe, G., additional, Sinquin, C., additional, Ratiskol, J., additional, Colliec-Jouault, S., additional, and Delbarre-Ladrat, C., additional
- Published
- 2012
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6. Les polysaccharides microbiens d’origine marine et leur potentiel en thérapeutique humaine
- Author
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Colliec-Jouault, S, primary, Zanchetta, P, additional, Helley, D, additional, Ratiskol, J, additional, Sinquin, C, additional, Fischer, A.M, additional, and Guezennec, J, additional
- Published
- 2004
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7. Sulfation and depolymerization of a bacterial exopolysaccharide of hydrothermal origin
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Guezennec, J, primary, Pignet, P, additional, Lijour, Y, additional, Gentric, E, additional, Ratiskol, J, additional, and Colliec-Jouault, S, additional
- Published
- 1998
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8. Preliminary report on fractionation of fucans by ion-exchange displacement centrifugal partition chromatography
- Author
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Chevolot, L., primary, Colliec-Jouault, S., additional, Foucault, A., additional, Ratiskol, J., additional, and Sinquin, C., additional
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- 1998
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9. A disaccharide repeat unit is the major structure in fucoidans from two species of brown algae
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Chevolot, L., Mulloy, B., Ratiskol, J., Foucault, A., and Colliec-Jouault, S.
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- 2001
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10. Improvement purification of sulfated oligofucan by ion-exchange displacement centrifugal partition chromatography
- Author
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Chevolot, L., Foucault, A., Colliec-Jouault, S., Ratiskol, J., and Sinquin, C.
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- 2000
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11. Exopolysaccharides produced by bacteria isolated from deep-sea hydrothermal vents: new agents with therapeutic potential
- Author
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Colliec-Jouault, S., Zanchetta, P., Helley, D., Ratiskol, J., Sinquin, C., Fischer, A.M., and Guezennec, J.
- Subjects
- *
MICROBIAL exopolysaccharides , *POLYSACCHARIDES , *ANTICOAGULANTS , *PHARMACEUTICAL industry - Abstract
Bacterial polysaccharides offer fascinating potential applications for the pharmaceutical industry. Although many known marine bacteria produce exopolysaccharides (EPS), continuation in looking for new polysaccharide-producing micro-organisms is promising. Marine bacteria, isolated from deep-sea hydrothermal vents, have demonstrated their ability to produce in aerobic conditions, unusual EPS. With the aim of discovering biological activities, EPS presenting different structural features were studied. An EPS secreted by Vibrio diabolicus was evaluated on the restoration of bone integrity in experimental model and was demonstrated to be a strong bone-healing material. Another EPS produced by Alteromonas infernus was modified in order to obtain new heparin-like compounds. Unlike the native EPS, the resulting EPS presented anticoagulant properties as heparin. These EPS could provide biochemical entities with suitable functions for obtaining new drugs. They present original structural feature that can be modified to design compounds and improve their specificity. [Copyright &y& Elsevier]
- Published
- 2004
- Full Text
- View/download PDF
12. Purification of the exopolysaccharide produced by Alteromonas infernus: identification of endotoxins and effective process to remove them.
- Author
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Du AG, Zykwinska A, Sinquin C, Ratiskol J, Weiss P, Vinatier C, Guicheux J, Delbarre-Ladrat C, and Colliec-Jouault S
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- Alteromonas drug effects, Detergents pharmacology, Endotoxins chemistry, Endotoxins deficiency, Endotoxins isolation & purification, Fermentation, Glycolipids chemistry, Glycolipids metabolism, Hydrothermal Vents microbiology, Lipopolysaccharides chemistry, Lipopolysaccharides deficiency, Molecular Weight, Monosaccharides pharmacology, Polysaccharides, Bacterial biosynthesis, Polysaccharides, Bacterial metabolism, Alteromonas metabolism, Endotoxins metabolism, Polysaccharides, Bacterial chemistry, Polysaccharides, Bacterial isolation & purification
- Abstract
Alteromonas infernus bacterium isolated from deep-sea hydrothermal vents can produce by fermentation a high molecular weight exopolysaccharide (EPS) called GY785. This EPS described as a new source of glycosaminoglycan-like molecule presents a great potential for pharmaceutical and biotechnological applications. However, this unusual EPS is secreted by a Gram-negative bacterium and can be therefore contaminated by endotoxins, in particular the lipopolysaccharides (LPS). Biochemical and chemical analyses of the LPS extracted from A. infernus membranes have shown the lack of the typical LPS architecture since 3-deoxy-D-manno-oct-2-ulopyranosonic acid (Kdo), glucosamine (GlcN), and phosphorylated monosaccharides were not present. Unlike for other Gram-negative bacteria, the results revealed that the outer membrane of A. infernus bacterium is most likely composed of peculiar glycolipids. Furthermore, the presence of these glycolipids was also detected in the EPS batches produced by fermentation. Different purification and chemical detoxification methods were evaluated to efficiently purify the EPS. Only the method based on a differential solubility of EPS and glycolipids in deoxycholate detergent showed the highest decrease in the endotoxin content. In contrast to the other tested methods, this new protocol can provide an effective method for obtaining endotoxin-free EPS without any important modification of its molecular weight, monosaccharide composition, and sulfate content.
- Published
- 2017
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13. Anti-Metastatic Properties of a Marine Bacterial Exopolysaccharide-Based Derivative Designed to Mimic Glycosaminoglycans.
- Author
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Heymann D, Ruiz-Velasco C, Chesneau J, Ratiskol J, Sinquin C, and Colliec-Jouault S
- Subjects
- Animals, Aquatic Organisms chemistry, Bone Neoplasms drug therapy, Bone Neoplasms metabolism, Bone Neoplasms pathology, Cell Line, Tumor, Cell Movement drug effects, Cell Proliferation drug effects, Cell Survival drug effects, Glycosaminoglycans pharmacology, Humans, Lung Neoplasms prevention & control, Lung Neoplasms secondary, Male, Matrix Metalloproteinases metabolism, Mice, Mice, Inbred C3H, Mice, Nude, Molecular Mimicry, Neoplasm Invasiveness prevention & control, Osteosarcoma drug therapy, Osteosarcoma pathology, Osteosarcoma secondary, Tissue Inhibitor of Metalloproteinases metabolism, Antineoplastic Agents isolation & purification, Antineoplastic Agents pharmacology, Polysaccharides, Bacterial pharmacology
- Abstract
Osteosarcoma is the most frequent malignant primary bone tumor characterized by a high potency to form lung metastases. In this study, the effect of three oversulfated low molecular weight marine bacterial exopolysaccharides (OS-EPS) with different molecular weights (4, 8 and 15 kDa) were first evaluated in vitro on human and murine osteosarcoma cell lines. Different biological activities were studied: cell proliferation, cell adhesion and migration, matrix metalloproteinase expression. This in vitro study showed that only the OS-EPS 15 kDa derivative could inhibit the invasiveness of osteosarcoma cells with an inhibition rate close to 90%. Moreover, this derivative was potent to inhibit both migration and invasiveness of osteosarcoma cell lines; had no significant effect on their cell cycle; and increased slightly the expression of MMP-9, and more highly the expression of its physiological specific tissue inhibitor TIMP-1. Then, the in vivo experiments showed that the OS-EPS 15 kDa derivative had no effect on the primary osteosarcoma tumor induced by osteosarcoma cell lines but was very efficient to inhibit the establishment of lung metastases in vivo. These results can help to better understand the mechanisms of GAGs and GAG-like derivatives in the biology of the tumor cells and their interactions with the bone environment to develop new therapeutic strategies.
- Published
- 2016
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14. A Direct Sulfation Process of a Marine Polysaccharide in Ionic Liquid.
- Author
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Chopin N, Sinquin C, Ratiskol J, Zykwinska A, Weiss P, Cérantola S, Le Bideau J, and Colliec-Jouault S
- Subjects
- Alteromonas chemistry, Aquatic Organisms chemistry, Ionic Liquids chemistry, Polysaccharides chemistry, Regenerative Medicine, Sulfates chemistry, Tissue Engineering, Chondrogenesis drug effects, Ionic Liquids administration & dosage, Mesenchymal Stem Cells drug effects, Polysaccharides administration & dosage
- Abstract
GY785 is an exopolysaccharide produced by a mesophilic bacterial strain Alteromonas infernus discovered in the deep-sea hydrothermal vents. GY785 highly sulfated derivative (GY785 DRS) was previously demonstrated to be a promising molecule driving the efficient mesenchymal stem cell chondrogenesis for cartilage repair. This glycosaminoglycan- (GAG-) like compound was modified in a classical solvent (N,N'-dimethylformamide). However, the use of classical solvents limits the polysaccharide solubility and causes the backbone degradation. In the present study, a one-step efficient sulfation process devoid of side effects (e.g., polysaccharide depolymerization and/or degradation) was developed to produce GAG-like derivatives. The sulfation of GY785 derivative (GY785 DR) was carried out using ionic liquid as a reaction medium. The successful sulfation of this anionic and highly branched heteropolysaccharide performed in ionic liquid would facilitate the production of new molecules of high specificity for biological targets such as tissue engineering or regenerative medicine.
- Published
- 2015
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15. Characterization of haloglycan, an exopolysaccharide produced by Halomonas stenophila HK30.
- Author
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Amjres H, Béjar V, Quesada E, Carranza D, Abrini J, Sinquin C, Ratiskol J, Colliec-Jouault S, and Llamas I
- Subjects
- Biofilms growth & development, Emulsions chemistry, Flocculation, Genes, Bacterial, Kinetics, Molecular Weight, Phylogeny, Polysaccharides, Bacterial ultrastructure, RNA, Ribosomal, 16S genetics, Rheology, Solutions, Viscosity, Halomonas chemistry, Polysaccharides, Bacterial biosynthesis
- Abstract
We have conducted a thorough study of the exopolysaccharide (EPS) produced by strain HK30 of Halomonas stenophila, which we have named haloglycan. This strain was chosen during an ongoing research programme aimed at finding novel exopolysaccharide-producing halophilic bacteria in unexplored hypersaline habitats. Strain HK30 was isolated from a saline-wetland in Brikcha (Morocco) and identified as belonging to the species H. stenophila. It produced EPS mainly during the exponential growth phase and to a lesser extent during the stationary phase. Culture parameters influenced both bacterial growth and EPS production, EPS yield always being directly related to the quantity of biomass. Under optimum culture conditions, strain HK30 produced 3.89 g of EPS per litre of medium. The polymer was a sulphated heteropolysaccharide composed of two fractions, with molecular masses of 8.2 × 10(4) and 1.4 × 10(6). The crude EPS contained 44 ± 0.1% w/w carbohydrates and the following monosaccharide composition: glucose (24 ± 1.73), glucuronic acid (7.5 ± 0.37), mannose (5.5 ± 0.17), fucose (4.5 ± 0.36), galactose (1.2 ± 0.17) and rhamnose (1 ± 0.05) (%, w/w). It produced solutions of high viscosity and pseudoplastic behaviour that showed interesting flocculating and emulsifying activities and was also involved in forming biofilm., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2015
- Full Text
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16. Genome sequence of Vibrio diabolicus and identification of the exopolysaccharide HE800 biosynthesis locus.
- Author
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Goudenège D, Boursicot V, Versigny T, Bonnetot S, Ratiskol J, Sinquin C, LaPointe G, Le Rous F, and Delbarre-Ladrat C
- Subjects
- Cluster Analysis, DNA, Bacterial chemistry, Molecular Sequence Data, Phylogeny, Seawater microbiology, Sequence Homology, Vibrio isolation & purification, Biosynthetic Pathways, DNA, Bacterial genetics, Genetic Loci, Genome, Bacterial, Polysaccharides biosynthesis, Sequence Analysis, DNA, Vibrio genetics
- Abstract
Vibrio diabolicus, a marine bacterium originating from deep-sea hydrothermal vents, produces the HE800 exopolysaccharide with high value for biotechnological purposes, especially for human health. Its genome was sequenced and analyzed; phylogenetic analysis using the core genome revealed V. diabolicus is close to another deep-sea Vibrio sp. (Ex25) within the Harveyi clade and Alginolyticus group. A genetic locus homologous to the syp cluster from Vibrio fischeri was demonstrated to be involved in the HE800 production. However, few genetic particularities suggest that the regulation of syp expression may be different in V. diabolicus. The presence of several types of glycosyltransferases within the locus indicates a capacity to generate diversity in the glycosidic structure, which may confer an adaptability to environmental conditions. These results contribute to better understanding exopolysaccharide biosynthesis and for developing new efficient processes to produce this molecule for biotechnological applications.
- Published
- 2014
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17. Unusual glycosaminoglycans from a deep sea hydrothermal bacterium improve fibrillar collagen structuring and fibroblast activities in engineered connective tissues.
- Author
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Senni K, Gueniche F, Changotade S, Septier D, Sinquin C, Ratiskol J, Lutomski D, Godeau G, Guezennec J, and Colliec-Jouault S
- Subjects
- Biocompatible Materials isolation & purification, Biocompatible Materials pharmacology, Biotechnology methods, Cell Proliferation drug effects, Connective Tissue metabolism, Fibrillar Collagens chemistry, Fibroblasts metabolism, Glycosaminoglycans isolation & purification, Humans, Polysaccharides, Bacterial isolation & purification, Vibrio chemistry, Fibroblasts drug effects, Glycosaminoglycans pharmacology, Polysaccharides, Bacterial pharmacology, Tissue Engineering methods
- Abstract
Biopolymers produced by marine organisms can offer useful tools for regenerative medicine. Particularly, HE800 exopolysaccharide (HE800 EPS) secreted by a deep-sea hydrothermal bacterium displays an interesting glycosaminoglycan-like feature resembling hyaluronan. Previous studies demonstrated its effectiveness to enhance in vivo bone regeneration and to support osteoblastic cell metabolism in culture. Thus, in order to assess the usefulness of this high-molecular weight polymer in tissue engineering and tissue repair, in vitro reconstructed connective tissues containing HE800 EPS were performed. We showed that this polysaccharide promotes both collagen structuring and extracellular matrix settle by dermal fibroblasts. Furthermore, from the native HE800 EPS, a low-molecular weight sulfated derivative (HE800 DROS) displaying chemical analogy with heparan-sulfate, was designed. Thus, it was demonstrated that HE800 DROS mimics some properties of heparan-sulfate, such as promotion of fibroblast proliferation and inhibition of matrix metalloproteinase (MMP) secretion. Therefore, we suggest that the HE800EPS family can be considered as an innovative biotechnological source of glycosaminoglycan-like compounds useful to design biomaterials and drugs for tissue engineering and repair.
- Published
- 2013
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18. Screening of enzymatic activities for the depolymerisation of the marine bacterial exopolysaccharide HE800.
- Author
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Rigouin C, Delbarre-Ladrat C, Ratiskol J, Sinquin C, Colliec-Jouault S, and Dion M
- Subjects
- Hydrolysis, Molecular Weight, Oligosaccharides chemistry, Oligosaccharides metabolism, Polysaccharides, Bacterial chemistry, Enterococcus faecalis enzymology, Hexosaminidases isolation & purification, Hexosaminidases metabolism, Mass Screening methods, Polysaccharides, Bacterial metabolism, Vibrio metabolism
- Abstract
The exopolysaccharide (EPS) HE800 is a marine-derived polysaccharide (from 8 × 10(5) to 1.5 × 10(6) g mol(-1)) produced by Vibrio diabolicus and displaying original structural features close to those of glycosaminoglycans. In order to confer new biological activities to the EPS HE800 or to improve them, structural modifications need to be performed. In particular, depolymerisation is required to generate low-molecular-weight derivatives. To circumvent the use of chemical methods that lack specificity and reproducibility, enzymes able to perform such reaction are sought. This study reports the screening for enzymes capable of depolymerising the EPS HE800. A large diversity of enzyme sources has been studied: commercially available glycoside hydrolases with broad substrate specificity, lyases, and proteases as well as growing microorganisms. Interestingly, we found that the genus Enterococcus and, more particularly, the strain Enterococcus faecalis were able to depolymerise the EPS HE800. Partial characterization of the enzymatic activity gives evidence for a random and incomplete depolymerisation pattern that yields low-molecular-weight products of 40,000 g mol(-1). Genomic analysis and activity assays allowed the identification of a relevant open reading frame (ORF) which encodes an endo-N-acetyl-galactosaminidase. This study establishes the foundation for the development of an enzymatic depolymerisation process.
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- 2012
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19. Sterilization of exopolysaccharides produced by deep-sea bacteria: impact on their stability and degradation.
- Author
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Rederstorff E, Fatimi A, Sinquin C, Ratiskol J, Merceron C, Vinatier C, Weiss P, and Colliec-Jouault S
- Subjects
- Animals, Beta Particles, Biological Products chemistry, Carbohydrate Sequence, Ethylene Oxide chemistry, Ethylene Oxide toxicity, Gamma Rays, Hot Temperature, Molecular Sequence Data, Molecular Weight, Oceans and Seas, Plasma Gases chemistry, Polysaccharides, Bacterial isolation & purification, Polysaccharides, Bacterial radiation effects, Polysaccharides, Bacterial toxicity, Rabbits, Spectroscopy, Fourier Transform Infrared, Viscosity, Alteromonas chemistry, Polysaccharides, Bacterial chemistry, Sterilization methods, Vibrio chemistry
- Abstract
Polysaccharides are highly heat-sensitive macromolecules, so high temperature treatments are greatly destructive and cause considerable damage, such as a great decrease in both viscosity and molecular weight of the polymer. The technical feasibility of the production of exopolysaccharides by deep-sea bacteria Vibrio diabolicus and Alteromonas infernus was previously demonstrated using a bioproduct manufacturing process. The objective of this study was to determine which sterilization method, other than heat sterilization, was the most appropriate for these marine exopolysaccharides and was in accordance with bioprocess engineering requirements. Chemical sterilization using low-temperature ethylene oxide and a mixture of ionized gases (plasmas) was compared to the sterilization methods using gamma and beta radiations. The changes to both the physical and chemical properties of the sterilized exopolysaccharides were analyzed. The use of ethylene oxide can be recommended for the sterilization of polysaccharides as a weak effect on both rheological and structural properties was observed. This low-temperature gas sterilizing process is very efficient, giving a good Sterility Assurance Level (SAL), and is also well suited to large-scale compound manufacturing in the pharmaceutical industry.
- Published
- 2011
- Full Text
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20. Marine polysaccharides: a source of bioactive molecules for cell therapy and tissue engineering.
- Author
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Senni K, Pereira J, Gueniche F, Delbarre-Ladrat C, Sinquin C, Ratiskol J, Godeau G, Fischer AM, Helley D, and Colliec-Jouault S
- Subjects
- Alginates pharmacology, Animals, Cyanobacteria metabolism, Glucuronic Acid pharmacology, Glycosaminoglycans chemistry, Glycosaminoglycans pharmacology, Glycosaminoglycans therapeutic use, Hexuronic Acids pharmacology, Humans, Oceans and Seas, Polysaccharides therapeutic use, Cell- and Tissue-Based Therapy, Polysaccharides pharmacology, Tissue Engineering
- Abstract
The therapeutic potential of natural bioactive compounds such as polysaccharides, especially glycosaminoglycans, is now well documented, and this activity combined with natural biodiversity will allow the development of a new generation of therapeutics. Advances in our understanding of the biosynthesis, structure and function of complex glycans from mammalian origin have shown the crucial role of this class of molecules to modulate disease processes and the importance of a deeper knowledge of structure-activity relationships. Marine environment offers a tremendous biodiversity and original polysaccharides have been discovered presenting a great chemical diversity that is largely species specific. The study of the biological properties of the polysaccharides from marine eukaryotes and marine prokaryotes revealed that the polysaccharides from the marine environment could provide a valid alternative to traditional polysaccharides such as glycosaminoglycans. Marine polysaccharides present a real potential for natural product drug discovery and for the delivery of new marine derived products for therapeutic applications.
- Published
- 2011
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21. Characterization of exopolysaccharides produced by cyanobacteria isolated from Polynesian microbial mats.
- Author
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Richert L, Golubic S, Guédès RL, Ratiskol J, Payri C, and Guezennec J
- Subjects
- Bacterial Capsules chemistry, Chromatography, Gas, Colorimetry, Cyanobacteria isolation & purification, Elements, Monosaccharides analysis, Polynesia, Spectrophotometry, Infrared, Sulfates analysis, Cyanobacteria chemistry, Polysaccharides, Bacterial chemistry, Water Microbiology
- Abstract
Six cyanobacterial isolates recovered from Polynesian microbial mats, called "kopara," were cultured using laboratory-closed photobioreactors and were shown to produce exopolymers as released and capsular exopolysaccharides (EPS). These polymers have been chemically characterized using colorimetric and elemental assays, infrared spectrometry, and gas chromatography. Both capsular and released EPS consisted of 7 to 10 different monosaccharides with neutral sugars predominating. Interestingly, four isolates exhibited sulfate contents ranging from 6% to 19%. On the basis of preliminary data, cyanobacteria from this unusual ecosystem appear to be an important source of novel EPS of a great interest in terms of their biological activities.
- Published
- 2005
- Full Text
- View/download PDF
22. Effect of an oversulfated exopolysaccharide on angiogenesis induced by fibroblast growth factor-2 or vascular endothelial growth factor in vitro.
- Author
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Matou S, Colliec-Jouault S, Galy-Fauroux I, Ratiskol J, Sinquin C, Guezennec J, Fischer AM, and Helley D
- Subjects
- Cell Differentiation drug effects, Cell Movement drug effects, Cell Proliferation drug effects, Cells, Cultured, Drug Synergism, Endothelial Cells cytology, Endothelial Cells drug effects, Humans, Fibroblast Growth Factor 2 pharmacology, Neovascularization, Physiologic drug effects, Polysaccharides, Bacterial pharmacology, Vascular Endothelial Growth Factors pharmacology
- Abstract
The aim of this study was to determine the angiogenic properties of an oversulfated exopolysaccharide (OS-EPS) derived from a polysaccharide secreted by the mesophilic bacterium Alteromonas infernus. We compared the effect of this OS-EPS with that of a non-oversulfated exopolysaccharide (EPS) on human umbilical vein endothelial cell (HUVEC) proliferation, migration and differentiation induced by basic fibroblast growth factor (FGF-2) or vascular endothelial growth factor (VEGF). OS-EPS enhanced HUVEC proliferation by 58% when used alone, and by respectively 30% and 70% in the presence of FGF-2 and VEGF. OS-EPS also increased the density of tubular structures on Matrigel in the presence of FGF-2 or VEGF. Vascular tube formation was related to alpha(6) integrin subunit expression, which was enhanced by 50% in the presence of the growth factors. Indeed, a monoclonal anti-alpha(6) blocking antibody abolished this vascular tube formation. EPS had no effect in any of the experimental conditions, underlying the importance of sulfation in the angiogenic effects of exopolysaccharide. By potentiating the angiogenic activity of FGF-2 and/or VEGF, OS-EPS, which possesses low anticoagulant activity and thus a low hemorrhagic risk, could potentially be used to accelerate vascular wound healing or to promote the growth of collateral blood vessels in ischemic tissues.
- Published
- 2005
- Full Text
- View/download PDF
23. Structural studies of the main exopolysaccharide produced by the deep-sea bacterium Alteromonas infernus.
- Author
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Roger O, Kervarec N, Ratiskol J, Colliec-Jouault S, and Chevolot L
- Subjects
- Carbohydrate Sequence, Molecular Sequence Data, Molecular Structure, Polysaccharides, Bacterial biosynthesis, Polysaccharides, Bacterial isolation & purification, Alteromonas metabolism, Polysaccharides, Bacterial chemistry
- Abstract
The structure of the extracellular polysaccharide produced by the mesophilic species, Alteromonas infernus, found in deep-sea hydrothermal vents and grown under laboratory conditions, has been investigated using partial depolymerization, methylation analysis, mass spectrometry and NMR spectroscopy. The repeating units of this polysaccharide is a nonasaccharide with the following structure: [carbohydrate: see text].
- Published
- 2004
- Full Text
- View/download PDF
24. A novel exopolymer-producing bacterium, Paracoccus zeaxanthinifaciens subsp. payriae, isolated from a "kopara" mat located in Rangiroa, an atoll of French Polynesia.
- Author
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Raguénès G, Moppert X, Richert L, Ratiskol J, Payri C, Costa B, and Guezennec J
- Subjects
- Base Composition, DNA, Bacterial chemistry, DNA, Bacterial genetics, Ecosystem, Genotype, Marine Biology, Paracoccus classification, Paracoccus genetics, Phenotype, Phylogeny, Polynesia, Polysaccharides, Bacterial chemistry, Spectroscopy, Fourier Transform Infrared, Paracoccus isolation & purification, Paracoccus metabolism, Polysaccharides, Bacterial biosynthesis
- Abstract
An aerobic, mesophilic and heterotrophic marine bacterium designated RA19, able to produce two different exocellular polymers and zeaxanthin, was isolated from a French polynesian bacterial mat (localy named "kopara") situated in the atoll of Rangiroa. This microorganism, on the basis of its phenotypical features and the genotypic investigations, can be clearly assigned to the Parococcus zeaxanthinifaciens species and the name Parococcus zeaxanthinifaciens subsp. payriae is proposed. Optimal growth occurs between 30 degrees C and 35 degrees C, at pH between 6.5 and 7.5 and at ionic strength between 20 and 40 g/L of NaCl. The guanine-plus-cytosine content of DNA was 65.6%. This bacterium excreted, under laboratory conditions, two different polymers: a water-soluble exopolysaccharide (EPSI) consisting of 5 different sugars and a non-water-soluble macromolecule assumed to be of a glycoproteinic nature. The high sulfate content of the EPS1 and preliminary biological tests clearly showed that applications could be found in the very near future for both polymers in the cosmetic area. Their contribution to the viscous laminated microbial mat locally called "kopara" can be also mentioned.
- Published
- 2004
- Full Text
- View/download PDF
25. [Microbial polysaccharides of marine origin and their potential in human therapeutics].
- Author
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Colliec-Jouault S, Zanchetta P, Helley D, Ratiskol J, Sinquin C, Fischer AM, and Guezennec J
- Subjects
- Alteromonas chemistry, Animals, Anticoagulants isolation & purification, Anticoagulants therapeutic use, Dogs, Drug Evaluation, Preclinical, Humans, Marine Biology, Polysaccharides, Bacterial chemistry, Polysaccharides, Bacterial isolation & purification, Polysaccharides, Bacterial therapeutic use, Rats, Sheep, Skull Fractures drug therapy, Vibrio chemistry, Water Microbiology, Wound Healing drug effects, Polysaccharides, Bacterial physiology
- Abstract
Bacterial polysaccharides offer fascinating potential applications for the pharmaceutical industry. Although many known marine bacteria produce exopolysaccharides (EPS), continuation in looking for new polysaccharide-producing micro-organisms is promising. Marine bacteria, isolated from deep-sea hydrothermal vents, have demonstrated their ability to produce in aerobic conditions, unusual EPS. With the aim of discovering biological activities, EPS presenting different structural features were studied. An EPS secreted by Vibrio diabolicus was evaluated on the restoration of bone integrity in experimental model and was demonstrated to be a strong bone-healing material. Another EPS produced by Alteromonas infernus was modified in order to obtain new heparin-like compounds. Unlike the native EPS, the resulting EPS presented anticoagulant properties as heparin. These EPS could provide biochemical entities with suitable functions for obtaining new drugs. They present original structural feature that can be modified to design compounds and improve their specificity.
- Published
- 2004
- Full Text
- View/download PDF
26. Characterization, chemical modifications and in vitro anticoagulant properties of an exopolysaccharide produced by Alteromonas infernus.
- Author
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Colliec Jouault S, Chevolot L, Helley D, Ratiskol J, Bros A, Sinquin C, Roger O, and Fischer AM
- Subjects
- Magnetic Resonance Spectroscopy, Methylation, Molecular Weight, Polysaccharides, Bacterial chemistry, Serpins chemistry, Thrombin, Alteromonas chemistry, Anticoagulants chemistry, Polysaccharides, Bacterial isolation & purification
- Abstract
A new low-molecular-weight 'heparin-like' component was obtained from an exopolysaccharide produced by a mesophilic strain found in deep-sea hydrothermal vents. Data concerning the structure of the native high-molecular-weight exopolysaccharide (10(6) g/mol, 10% sulfate content) are reported for the first time. Two depolymerization processes were used to obtain low-molecular-weight (24-35x10(3) g/mol) oversulfated fractions (sulfate content 20 or 40%). Nuclear magnetic resonance studies indicated that after sulfation (40%), the low-molecular-weight fraction obtained by free radical depolymerization was less sulfated in the 6-O-position than the fraction depolymerized by acid hydrolysis. The free radical depolymerized product also had sulfated residues in the 4-O-position and disulfated ones in the 2,3-O-positions. Moreover, the compounds generated by the free radical process were more homogeneous with respect to molecular mass. Also for the first time, the anticoagulant activity of the low-molecular-weight exopolysaccharide fractions is reported. When the fractions obtained after sulfation and depolymerization were compared with heparins, anticoagulant activity was detected in oversulfated fractions, but not in native exopolysaccharide. The free radical depolymerized fraction inhibited thrombin generation in both contact-activated and thromboplastin-activated plasma, showing a prolonged lag phase only in the contact-activated assay. Affinity co-electrophoresis studies suggested that a single population of polysaccharide chains binds to antithrombin and that only a subpopulation strongly interacts with heparin cofactor II.
- Published
- 2001
- Full Text
- View/download PDF
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