Chemical characterization of exopolysaccharides from the marine fouling diatom Amphora coffeaeformis

Amphora coffeaeformis cells were grown in batch cultures under continuous illumination at 18 degrees C for 10 d. Algal cells were removed by centrifugation, lyophilized and used for the extraction of exopolysaccharides using either 0.05 M EDTA, 1 M NaOH or 1.5 M NaCl. The 1.5 M NaCl treatment removed most exopolysaccharides. Glucose (81%) was the most abundant monosaccharide in the exopolysaccharides. The chemical composition data suggest that the exopolymers were acidic sulphated polysaccharides containing high concentrations of pyruvate (22%) and uronic acids (18%). These polysaccharides may play an important role in metal complexation and protection from desiccation in A. coffeaeformis.