|
|
|
|
|
Ortega Morales, Benjamín Otto; Santiago Garcia, J.l; Chan Bacab, M.j.; Moppert, Xavier; Miranda Tello, E; Fardeau, M.l.; Carrero, J.c.; Bartolo Perez, P.; Valadez Gonzalez, A; Guezennec, Jean. |
Aims: This study was performed to determine the potential of tropical intertidal biofilm bacteria as a source of novel exopolymers (EPS). Methods and Results: A screening procedure was implemented to detect EPS-producing biofilm bacteria. Isolates MC3B-10 and MC6B-22, identified respectively as a Microbacterium species and Bacillus species by 16S rDNA and cellular fatty acids analyses, produced different EPS, as evidenced by colorimetric and gas chromatographic analyses. The polymer produced by isolate MC3B-10 displays significant surfactant activity, and may chelate calcium as evidenced by spectroscopic analysis. Conclusions: Polymer MC3B-10 appears to be a glycoprotein, while EPS MC6B-22 seems to be a true polysaccharide dominated by neutral sugars... |
Tipo: Text |
Palavras-chave: Tropical intertidal biofilm bacteria; Surfactants; Microbacterium sp; Exopolymers; Bacillus sp; Anionic. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-2530.pdf |
| |
|
|
Moppert, Xavier; Le Costaouec, Tinaig; Raguenes, Gerard; Courtois, Anthony; Simon-colin, Christelle; Crassous, Philippe; Costa, Bernard; Guezennec, Jean. |
A bacterium isolated from microbial mats located on a polynesian atoll produced a high molecular weight (3,000 kDa) and highly sulphated exopolysaccharide. Previous studies showed that the chemical structure of this EPS consisted of neutral sugars, uronic acids, and high proportions of acetate and sulphate groups. The copper- and iron-binding ability of the purified pre-treated native EPS was investigated. Results showed that this EPS had a very high affinity for both copper (9.84 mmol g(-1) EPS) and ferrous iron (6.9 mmol g(-1) EPS). Amazingly, this EPS did not show any affinity for either ferric ions or selenium salts. This finding is one of the first steps in assessing the biotechnological potential of this polysaccharide. |
Tipo: Text |
Palavras-chave: Sulphated exopolysaccharide; Microbial mats; Iron; Copper; Binding capacity. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6397.pdf |
| |
|
|
Guezennec, Jean; Moppert, Xavier; Raguenes, Gerard; Richert, Laurent; Costa, Bernard; Simon-colin, Christelle. |
It is well known that microorganisms well-adapted to survival in extreme ecosystems could be considered as new sources of biomolecules that have biotechnological importance. On French Polynesian atolls, microbial mats are developing in water ponds exposed to fluctuations in physical and chemical parameters. In these microbial mats, which are called "kopara" by the inhabitants, bacteria coexist with cyanobacteria, and a synergistic relationship may exist between these two types of living microorganisms. A large number of cyanobacteria and bacteria have been isolated from different mats. Under laboratory conditions, these microorganisms were shown to produce various exopolymers, including exopolysaccharides and poly-beta-hydroxyalkanoates, along with... |
Tipo: Text |
Palavras-chave: Microbial mats; Kopara; Biopolymers; Exopolysaccharides; Poly-beta-hydroxyalkanoates. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00029/14058/11423.pdf |
| |
|
|
|