IR study of self-assembly of capsular exopolymers from Pseudomonas sp NCIMB 2021 on hydrophilic and hydrophobic surfaces

Capsular exopolymers (EPS) of the bacterium Pseudomonas sp. NCIMB 2021 are allowed to self-assemble on hydrophilic and hydrophobic gold surfaces. Tapp ing mode atomic force microscopy confirms the differences in the surface to pography between EPS adsorbed on both surfaces. Fourier-transform IR spectr oscopy indicates that the EPS surface coverage is much greater on the hydro phobic surface. Furthermore, an increased contribution is observed from hyd rophobic (i.e., methyl and tyrosyl residues) and electrostatic (i.e., carbo xylate residues) groups at the hydrophobic surface, but there is relatively less neutral polymer compared to the hydrophilic surface. The behavior of this EPS is in agreement with the behavior of cells of Pseudomonas sp. NCIM B 2021 at hydrophilic and hydrophobic surfaces. (C) 2000 John Wiley & Sons, Inc.