Influence of surface chemistry of the substrate on the adsorption of Escherichia coli.

The adsorption of Escherichia coli as influenced by the surface chemistry of different absorbents was studied with microbeads of (1) polystyrene, hydroxymethylated, chloromethylated and aminomethylated polystyrene, (2) cation and anion exchange resins, (3) glass and siliconized glass using a shake test. The adsorption kinetics can be described by a first order rate law for all materials. The specific surface free energy is not even a rough correlation parameter for the adsorption effect. Polar groups with the exception of those with a negative charge (cation exchange resin) favour adsorption of Escherichia coli, but the type of the polar surface group plays a dominating role. Adsorption was maximum with protonated aminomethylated polystyrene which is attributed to the interaction of the positive charge with the negatively charged bacterial surface.