THERMAL-STABILITY OF SUCCINATE GROUPS IN THE EXOPOLYSACCHARIDE MARGINALAN

An investigation on the possible effect of temperature on the conforma tion of the exocellular polysaccharide marginalan, produced by Pseudom onas marginalis strain HT041B, in aqueous solutions led to the observa tion that 30% of the succinate groups were peeled off from the polymer ic backbone when polymeric solutions were heated at 70 degrees C. This desuccinylation effect was investigated by means of NMR, circular dic hroism and viscosity measurements. The experimental findings were comp ared with those obtained for a sample of chemically desuccinylated mar ginalan. A possible mechanism for the temperature-induced hydrolysis o f succinate groups is discussed.