Physico-chemical studies on the bacterial polysaccharide-surfactant aggregates with special reference to their hydrodynamic behaviors Abstract

Capsular polysaccharides (SPS) are the integral components of gram-negative bacteria, and also have potential uses as vaccines. In this paper, interaction of anionic SPS, isolated from Klebsiella K28, K43, K51 and K20, with cationic surfactants and cationicnonionic mixed surfactants were investigated by turbidimetric titration, viscometric method. Variation of size and zeta-potential was measured using dynamic light scattering method. Due to binding of the surfactants size enhancement and charge reversal takes place. The interaction between oppositely charged polymer-surfactants are governed by the nature of the charged head group and of the counter ion, charge density and rigidity of the polymer architecture, CMC of the surfactant systems, concentrations of surfactant (Cs). The binding is influenced both by electrostatic and hydrophobic interaction. Communicated to Colloids Surf. B: Biointerfaces