13C-NMR study of the interaction of bacterial alginate with bivalent cations.

The effect of bivalent cations on solutions of extracellular polymeric substances (EPS) isolated from Pseudomonas aeruginosa was monitored by means of solid-state nuclear magnetic resonance. In particular, the binding of Ca2+ and Mg2+ to the alginate in aqueous solution was studied by determining the spin-lattice relaxation rates, line widths and line shapes of 13C nuclei under variation of the ion concentration. Both cations differ strongly in their affinity towards bacterial alginate. Spectral data indicate that the strong binding capacity of calcium is connected to the formation of a chelate complex, in which binding occurs particularly with the monomer units in alternating mannuronate-guluronate blocks. In contrast to this, binding of magnesium ions was found to be much weaker and non-specific.

[1]  A. Leis,et al.  Isolation and biochemical characterization of extracellular polymeric substances from Pseudomonas aeruginosa. , 2001, Methods in enzymology.

[2]  E. Morris,et al.  Biological interactions between polysaccharides and divalent cations: The egg‐box model , 1973 .

[3]  D. Day,et al.  Role of acetylation on metal induced precipitation of alginates , 1996 .

[4]  Jost Wingender,et al.  What are Bacterial Extracellular Polymeric Substances , 1999 .

[5]  J. Wingender,et al.  Characterization of mucoid Pseudomonas aeruginosa strains isolated from technical water systems. , 1995, The Journal of applied bacteriology.

[6]  J. Costerton,et al.  Bacterial biofilms in nature and disease. , 1987, Annual review of microbiology.

[7]  M. C. Jarvis,et al.  Acetylation and methylation of homogalacturonans 2: effect on ion-binding properties and conformations , 1999 .

[8]  C. Mayer,et al.  13C nuclear magnetic resonance studies on selectively labeled bacterial biofilms , 2001, Journal of Industrial Microbiology and Biotechnology.

[9]  S. Pérez,et al.  Conformational and configurational features of acidic polysaccharides and their interactions with calcium ions: a molecular modeling investigation. , 1999, Carbohydrate research.

[10]  C. Mayer,et al.  Monomer composition and sequence of alginates from Pseudomonas aeruginosa. , 2002, International journal of biological macromolecules.

[11]  C. Kirschner,et al.  The role of intermolecular interactions: studies on model systems for bacterial biofilms. , 1999, International journal of biological macromolecules.

[12]  K. Cooksey.  Extracellular Polymers in Biofilms , 1992 .

[13]  J. Nauss,et al.  13C NMR and molecular modeling studies of alginic acid binding with alkaline earth and lanthanide metal ions , 1997 .

[14]  E. Fenton,et al.  Interactions of calcium and aluminium ions with alginate , 1996 .

[15]  Bjørn Larsen,et al.  13C-n.m.r. studies of monomeric composition and sequence in alginate , 1981 .