The effect of surfactants on the attachment of estuarine and marine bacteria to surfaces

Abstract

The effect of dilute surfactants on bacterial attachment to hydrophilic and hydrophobic substrata has been investigated. Triton X-100 at 0.002% completely inhibited attachment to polystyrene, a hydrophobic surface, for 10 of 11 isolates and all isolates at 0.01%. This concentration of surfactant also caused displacement of previously attached Vibrio proteolytica cells. Attachment to glass, a hydrophilic substratum, was far less sensitive to surfactants, and one isolate showed no inhibition at 0.1%, the highest concentration employed. Concentrations of surfactant sufficient to completely inhibit attachment had no effect on growth. In view of these results, it is thought that toxicity is not the mode of action of the surfactants, but rather disruption of hydrophobic interactions between the cell surface and polystyrene. The results imply the existence of a separate, surfactant-independent adhesion mechanism for hydrophilic surfaces in several isolates.