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| Simon-colin, Christelle; Alain, Karine; Colin, Sebastien; Cozien, Joelle; Costa, B; Guezennec, Jean; Raguenes, Gerard. |
| Aims: The aim of the present study was to describe an aerobic, mesophilic and heterotrophic bacterium, designated RA26, able to produce a medium-chain-length polyhydroxyalkanoate (PHA). It was isolated from a French Polynesian bacterial mat located in the atoll of Rangiroa. Methods and Results: This micro-organism, on the basis of the phenotypical features and genotypic investigations can be clearly assigned to the Pseudomonas genus and the name of Pseudomonas guezennei is proposed. Optimal growth occurs between 33 and 37 degrees C, at a pH between 6 4 and 7 1 and at ionic strength of 15 g 1(-1) of sea salts. The G+C content of DNA is 63.2%. Under laboratory conditions, this bacterium produced a novel, medium-chain-length PHA, mainly composed of... |
| Tipo: Text |
Palavras-chave: Pseudomonas; Polyhydroxyalkanaote; Microbial mat; Kopara. |
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-3858.pdf |
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| Richert, Laurent; Golubic, Stjepko; Le Guedes, Roland; Herve, Annie; Payr, Claude. |
| Cyanobacterial populations, the primary producers and builders of 'kopara' microbial mats were studied in four selected ponds along the rim of the Rangiroa Atoll, French Polynesia using a polyphasic approach. Seven isolates were maintained in uni-cyanobacterial cultures, characterized morphotypically and phylogenetically by evaluating sequences of the 16S rRNA gene of about 620 base pairs in length. Cyanobacteria in natural populations were analyzed microscopically, characterized morphotypically, and compared with cultured strains. Three of the isolates were identified in the field samples: Lyngbya aestuarii, Johannesbaptistia pellucida and Chroococcus submarinus were present in the mats only as minor components, whereas the species of Schizothrix that... |
| Tipo: Text |
Palavras-chave: 16S rRNA; Polyphasic approach; Phylogeny; Microbial mats; Microbial ecology; Kopara; Diversity; Cyanobacteria; Culture. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2050.PDF |
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| 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 |
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