Macromolecular and solution properties of Cepacian: the exopolysaccharide produced by a strain of Burkholderia cepacia isolated from a cystic fibrosis patient

• Published in: Carbohydrate research Vol. 338; no. 18; pp. 1861 - 1867
• Main Authors: Sist, Paola, Cescutti, Paola, Skerlavaj, Silvia, Urbani, Ranieri, Leitão, Jorge H., Sá-Correia, Isabel, Rizzo, Roberto
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.09.2003
• Subjects: Acetates - chemistry; Bacterial polysaccharide; Burkholderia cepacia - chemistry; Burkholderia cepacia - metabolism; Carbohydrate Conformation; Chlorates - chemistry; Circular Dichroism; Cystic fibrosis; Cystic Fibrosis - complications; Cystic Fibrosis - microbiology; Humans; Hydrogen-Ion Concentration; Light scattering; Magnetic Resonance Spectroscopy; Molecular Weight; Polysaccharides, Bacterial - chemistry; Polysaccharides, Bacterial - isolation & purification; Potentiometric titration; Scattering, Radiation; Sodium Hydroxide - chemistry; Temperature; Titrimetry; Viscosity; Viscosity; Cystic fibrosis; Light scattering; Bacterial polysaccharide; Potentiometric titration
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/S0008-6215(03)00306-9

Light scattering and viscosity measurements were carried out on the previously chemically characterised exopolysaccharide produced by a strain of Burkholderia cepacia isolated from a cystic fibrosis patient. The same exopolysaccharide was also produced by other clinical strains in different laboratories. Therefore, the name Cepacian is now proposed for this exopolysaccharide. Experiments performed as a function of the ionic strength on the native polymer revealed a change in the overall shape of the polymer at low ionic strength. This behaviour was absent in the de-acetylated sample. Potentiometric titrations and light scattering experiments carried out on the acidic form of the native polymer revealed the formation of macromolecular aggregates with a stoichiometry n and 2 n stabilised by interactions involving the uronic acid residues. Light scattering, viscosity and potentiometric titration experiments defined the aggregation properties of the exopolysaccharide produced by a bacterial strain involved in cystic fibrosis pulmonary infections.