Effect of surface shear stress on the attachment of Pseudomonas fluorescens to stainless steel under defined flow conditions

The application of the radial-flow growth chamber to the study of the initial stages of bacterial adhesion to surfaces under flowing conditions is reported. The adhesive properties of the bacterium Pseudomonas fluorescens (NCIB 9046) to stainless steel (type AISI 316) were found to be highly dependent on surface shear stress and the time and concentration of cells used in the incubation procedure. Maximum levels of adhesion occurred in zones of lowest surface shear stress, particularly less than 6-8 Nm(-2). Adhesion was still noticeable at shear stresses even up to 130 Nm(-2). Significant detachment of cells from a monolayer attached under static conditions was found to occur at surface shear stresses in excess of 10-12 Nm(-2).