Characterization of the polysaccharides chemical diversity of the cyanobacteria Arthrospira platensis

Polysaccharides (PS) from photosynthetic microorganisms have gained interest over the last decade, due to very large variety of chemical structures and potential original physico-chemical and/or biological properties. Among them, the cyanobacterium Arthrospira platensis is one of the most studied strains. However, depending on studies, diversity of PS (EPS and glycogen) amounts and compositions are proposed, and no clear link could be established to the culture conditions. The aim of this study was to investigate those effects by performing a bibliographic meta-analysis. The incident light was identified as the most influencing parameter and was investigated experimentally in photobioreactors. The produced PS were quantified and analyzed, confirming that glycogen and EPS amounts are strongly affected by this parameter, with EPS/glycogen ratios decreasing from 3.1 at 100 mu mol(h nu) m(-2)s(-1) to 0.6 at 1200 mu mol(h nu) m(-2)s(-1). Moreover, a significant decrease in uronic acids of EPS was observed for high light fluxes.