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Registros recuperados: 12 | |
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Gobet, Angelique; Barbeyron, Tristan; Matard-mann, Maria; Magdelenat, Ghislaine; Vallenet, David; Duchaud, Eric; Michel, Gurvan. |
About half of seaweed biomass is composed of polysaccharides. Most of these complex polymers have a marked polyanionic character. For instance, the red algal cell wall is mainly composed of sulfated galactans, agars and carrageenans, while brown algae contain alginate and fucose-containing sulfated polysaccharides (FCSP) as cell wall polysaccharides. Some marine heterotrophic bacteria have developed abilities to grow on such macroalgal polysaccharides. This is the case of Pseudoalteromonas carrageenovora 9(T) (ATCC 43555(T)), a marine gammaproteobacterium isolated in 1955 and which was an early model organism for studying carrageenan catabolism. We present here the genomic analysis of P. carrageenovora. Its genome is composed of two chromosomes and of a... |
Tipo: Text |
Palavras-chave: Carrageenan; CAZymes; Alginate; Gammaproteobacteria; Pseudoalteromonas; Marine bacteria; Algal holobiont; Biofilm. |
Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00489/60070/63377.pdf |
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Le Norcy, Tiffany; Niemann, Hendrik; Proksch, Peter; Linossier, Isabelle; Vallee-rehel, Karine; Hellio, Claire; Fay, Fabienne. |
Dibromohemibastadin-1 (DBHB) is an already known potent inhibitor of blue mussel phenoloxidase (which is a key enzyme involved in bioadhesion). Within this study, the potentiality of DBHB against microfouling has been investigated. The activity of DBHB was evaluated on key strains of bacteria and microalgae involved in marine biofilm formation and bioassays assessing impact on growth, adhesion and biofilm formation were used. To assess the efficiency of DBHB when included in a matrix, DBHB varnish was prepared and the anti-microfouling activity of coatings was assessed. Both in vitro and in situ immersions were carried out. Confocal Laser Scanning Microscopy (CLSM) was principally used to determine the biovolume and average thickness of biofilms developed... |
Tipo: Text |
Palavras-chave: Antifouling; Biodegradable coating; Hemibastadin; Sponges; Marine bacteria; Microalgae. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00616/72812/72626.pdf |
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Nichols, Carol; Bowman, John; Guezennec, Jean. |
The sea ice microbial community plays a key role in the productivity of the Southern Ocean. Exopolysaccharide (EPS) is a major component of the exopolymer secreted by many marine bacteria to enhance survival and is abundant in sea ice brine channels, but little is known about its function there. This study investigated the effects of temperature on EPS production in batch culture by CAM025, a marine bacterium isolated from sea ice sampled from the Southern Ocean. Previous studies have shown that CAM025 is a member of the genus Pseudoalteromonas and therefore belongs to a group found to be abundant in sea ice by culture-dependent and -independent techniques. Batch cultures were grown at -2 degrees C, 10 degrees C, and 20 degrees C, and cell number, optical... |
Tipo: Text |
Palavras-chave: EPS yield; Psychrotolerant; Sea ice; Marine bacteria; Antarctica; Exopolymer; Exopolysaccharides. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-625.pdf |
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Delbarre-ladrat, Christine; Salas, Marcia Leyva; Sinquin, Corinne; Zykwinska, Agata; Colliec-jouault, Sylvia. |
Many bacteria biosynthesize structurally diverse exopolysaccharides (EPS) and excrete them into their surrounding environment. The EPS functional features have found many applications in industries such as cosmetics and pharmaceutics. In particular, some EPS produced by marine bacteria are composed of uronic acids, neutral sugars, and N-acetylhexosamines, and may also bear some functional sulfate groups. This suggests that they can share common structural features with glycosaminoglycans (GAG) like the two EPS (HE800 and GY785) originating from the deep sea. In an attempt to discover new EPS that may be promising candidates as GAG-mimetics, fifty-one marine bacterial strains originating from deep-sea hydrothermal vents were screened. The analysis of the... |
Tipo: Text |
Palavras-chave: Exopolysaccharides; GAG; Marine bacteria; Glycopolymers; Sulfate; Production. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00399/51090/51873.pdf |
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Fourquez, Marion; Obernosterer, Ingrid; Blain, Stephane. |
Heterotrophic bacteria are key players in the biogeochemical cycle of iron (Fe) in the ocean, but the capability of different bacterial groups to access this micronutrient is ignored thus far. The aim of our study was to develop a protocol for the combined application of microautoradiography (MICRO) and catalyzed reporter depositionfluorescence in situ hybridization (CARD-FISH) using the radioisotope 55Fe. Among the different washing solutions tested, Ti-citrate-EDTA was the most efficient for the removal of extracellular 55Fe providing sufficiently low background values. We further demonstrate that the washing of cells with Ti-citrate-EDTA and the fixation with paraformaldehyde or formaldehyde do not induce leakage of intracellular 55Fe. Incubating... |
Tipo: Text |
Palavras-chave: Microautoradiography; 55Fe; CARD-FISH; Marine bacteria. |
Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00143/25403/23555.pdf |
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Senni, Karim; Pereira, Jessica; Gueniche, Farida; Delbarre-ladrat, Christine; Sinquin, Corinne; Ratiskol, Jacqueline; Godeau, Gaston; Fischer, Anne-marie; Helley, Dominique; Colliec-jouault, Sylvia. |
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... |
Tipo: Text |
Palavras-chave: Marine bacteria; Marine algae; Exopolysaccharides; Sulfated polysaccharides; Structure; Chemical modification; Biological activity; Blue biotechnology; Cell therapy; Tissue engineering. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00048/15894/13316.pdf |
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Nichols, Carol; Lardiere, Sandrine; Bowman, John; Nichols, Peter; Gibson, John; Guezennec, Jean. |
Exopolysaccharides (EPS) may have an important role in the Antarctic marine environment, possibly acting as ligands for trace metal nutrients such as iron or providing cryoprotection for growth at low temperature and high salinity. Ten bacterial strains, isolated from Southern Ocean particulate material or from sea ice, were characterized. Whole cell fatty acid profiles and 16S rRNA gene sequences showed that the isolates included representatives of the genera Pseudoalteromonas, Shewanella, Polaribacter, and Flavobacterium as well as one strain, which constituted a new bacterial genus in the family Flavobacteriaceae. The isolates are, therefore, members of the "Gammaproteobacteria" and Cytophaga-Flexibacter-Bacteroides, the taxonomic groups that have been... |
Tipo: Text |
Palavras-chave: Marine particulates; Sea ice; Marine bacteria; Antarctica; Exopolysaccharides. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-623.pdf |
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Dufourcq, R.; Chalkiadakis, Eletherios; Fauchon, M.; Deslandes, Eric; Kerjean, V.; Chanteau, S.; Petit, Elodie; Guezennec, Jean; Dupont-rouzeyrol, M.. |
Marine bacteria are a rich source of bioactive metabolites. However, the microbial diversity of marine ecosystem still needs to be explored. The aim of this study was to isolate and characterize bacteria with antimicrobial activities from various marine coastal environment of New Caledonia. We obtained 493 marine isolates from various environments and samples of which 63 (12.8%) presented an antibacterial activity against a panel of reference pathogenic strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis). Ten out of the most promising strains were cultured, fractionated and screened for antibacterial activity. Four of them (NC282, NC412, NC272 and NC120) showed at least an activity against reference and... |
Tipo: Text |
Palavras-chave: Antibacterial activity; Characterization; Marine bacteria; New Caledonia; Screening. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00174/28552/26994.pdf |
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Wei,Shiping; Cui,Hongpeng; Jiang,Zhenglong; Liu,Hao; He,Hao; Fang,Nianqiao. |
Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these species, Sporosarcina sp. dominated the cultured isolates. B. lentus CP28 generated higher urease activity and facilitated more efficient precipitation of calcium carbonate at 3.24 ± 0.25 × 10−4 mg/cell. X-ray diffraction indicated that the dominant calcium carbonate phase was calcite. Scanning electron microscopy showed that morphologies of the minerals were dominated by cubic, rhombic and polygonal... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Calcium carbonate precipitation; Calcite; Marine bacteria; Urease. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000200455 |
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Registros recuperados: 12 | |
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