THE EFFECT OF ACETYLATION ON CATION-BINDING BY ALGAL AND BACTERIAL ALGINATES

The aims of this study were to compare cation binding by bacterial and algal alginates in solution and to assess the influence of acetylatio n on ion uptake and selectivity. Metal uptake was carried out by equil ibrium dialysis, and samples were analysed by using ion chromatography . The uptake of ions was dependent on the ratio mannuronic acid/guluro nic acid, and a binding selectivity of Sr > Ca > Mg > K > Na > Li was found. The algal alginates showed much greater uptake and selectivity than the native bacterial alginates. Once the bacterial alginates were deacetylated, the uptake and selectivity increased significantly, ind icating the inhibitory role of the O-acetyl groups present on the D-ma nnuronosyl residues.