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2018-09-13 - Colloque/Présentation - poster - Anglais - 1 page(s)

Van Camp Camille , Wattiez Ruddy , "The exopolysaccharide production by Cyanothece sp. PCC 7822 through an adapted metabolism" in Workshop-Summer School UMONS-ALPO INTERREG FWVL : nouveaux matériaux polymères issus de la biomasse micro-algale, Mons, Belgique, 2018

  • Codes CREF : Biochimie (DI3112), Biologie moléculaire (DI3111), Microbiologie et protistologie [bacteriol.,virolog.,mycolog.] (DI3130)
  • Unités de recherche UMONS : Protéomie et Microbiologie (S828)
  • Instituts UMONS : Institut des Biosciences (Biosciences)
Texte intégral :

Abstract(s) :

(Anglais) The present research is a part of the Algotech project based on high-added value compounds production by Microalgae/Cyanobacteria. In this context, we investigate exopolysaccharide production by Cyanobacteria because of their properties and applications in cosmetics, medicine or food industries. In addition, the use of these organisms for EPS production has numerous positive aspects compared to microalgae or plants as high growth rate, easier manipulation by genetic engineering or economical costs of production. Cyanothece sp. PCC 7822, an unicellular diazotrophic cyanobacterium, was selected due to its ability to produce high rate of EPS. This study focuses on the impact of culture conditions on the bacterium metabolism and EPS production. Four different N sources (NaNO3, NH4Cl, Urea and atmospheric N2 at 17 mM in term of N) are tested in continuous light or in 12h/12h light/dark cycle. First results indicate that NaNO3 as N source induces the best growth in the 2 light conditions tested. The strain is also able to growth in presence of ammonium but not urea even if urease genes are presents in the genome. Observation of EPS by alcian blue staining indicates the presence of carboxylic and sulphated groups in their composition. Variation of EPS configuration according light parameters and N sources is highlighted which could be related to changes in exopolysaccharide composition. Moreover, EPS configuration seems also to change over the growth in a same condition. Furthermore, pigments profile has been done in order to characterize the strain PCC 7822 and standardize EPS concentration. In the frame of a project implicated in microalgal energetics and biomass promotion, this work targets the EPS production by Cyanothece sp. PCC 7822 by using innovative processes. This bacterium Cyanothece sp. PCC 7822 shows its full potential by its EPS composed of carboxylic and especially sulphated group which is not the case with microalgae. In fine, this particular composition leads to saccharides with interesting industrial properties.


Mots-clés :
  • (Anglais) nitrogen source
  • (Anglais) Cyanobacteria
  • (Anglais) exopolysaccharide