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| Mancuso Nichols, Carol; Guezennec, Jean; Bowman, John. |
| Exopolysaccharides (EPSs) are high molecular weight carbohydrate polymers that make up a substantial component of the extracellular polymers surrounding most microbial cells in the marine environment. EPSs constitute a large fraction of the reduced carbon reservoir in the ocean and enhance the survival of marine bacteria by influencing the physicochemical environment around the bacterial cell. Microbial EPSs are abundant in the Antarctic marine environment, for example, in sea ice and ocean particles, where they may assist microbial communities to endure extremes of temperature, salinity, and nutrient availability. The microbial biodiversity of Antarctic ecosystems is relatively unexplored. Deep-sea hydrothermal vent environments are characterized by high... |
| Tipo: Text |
Palavras-chave: Ecosystems Hydrothermal Microbial; Polymers EPSs. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-624.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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| 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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| Nichols, Carol Mancuso; Bowman, John; Guezennec, Jean. |
| A Gram-negative, aerobic, gliding, orange-yellow marine bacterium was isolated from particulate material sampled from the Southern Ocean. This strain produced an exopolysaccharide in liquid culture. 16S rRNA gene sequence analysis showed that this isolate was a member of the family Flavobacteriaceae, but represented a separate lineage. Major whole-cell fatty acids included i15:1 omega 10c, i15:0, beta-OH i15:0, a15:1 omega 10c, 15:0 and alpha-OH i15:0. The G+C content of the DNA was 49 mol%. Based on phylogenetic, phenotypic, chemotaxonomic and genotypic analyses, this bacterium was placed in a novel taxon as Olleya marilimosa gen. nov., sp. nov. with type strain CAM030(T) (=ACAM 1065(T)=CIP 108537(T)). |
| Tipo: Text |
Palavras-chave: Microbiology; Classification; Identification; Bacterie. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-457.pdf |
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