THE INFLUENCE OF METALLIC SURFACE WETTABILITY ON BACTERIAL ADHESION

The wettability of AISI 304 stainless steel with 2B and 2RB surface fi nishes expressed in terms of the solid surface free energy (gamma(S)) was investigated with respect to the cleaning process. It was shown th at cleaning affects the wettability of a solid surface. Depending on t he cleaning method, gamma(S) ranged from 43.4 to 277.8 mJ m-2 for the 2RB surface and from 34.4 to 122.8 mJ m-2 for the 2B surface. There wa s no direct relationship between the number of adhering bacteria and g amma(S) or the wettability of solids. However, it was found that the a dhesion of Streptococcus thermophilus was driven by a balance between gamma(S)d and gamma(S)P. The experimental results are as expected base d on thermodynamic predictions when the spreading pressure (pi(c)) is accounted for in the surface free energy of bacteria, gamma(B), determ ination.