EFFECTS OF SUBSTRATUM HYDROPHOBICITY AND STERIC HINDRANCE ON ADHESION OF A MARINE PSEUDOMONAS SP.

Many studies on the adhesion of microorganisms and eucaryotic cells to inanimate surfaces have focused on the chemical and physical properties of the substratum. Several general trends have been observed, such as higher levels of bacterial adhesion and protein adsorption on hydrophobic surfaces as compared to hydrophilic substrata (Marshall, 1985; Pringle and Fletcher, 1983). However, there is enough conflicting evidence to prevent the prediction of bacterial adhesion based solely on substratum hydrophobicity (Dexter et al., 1975; Pedersen et al., 1986). Steric repulsion may retard adhesion of proteins (Lee, et al., 1988; Prime and Whitesides, 1991), eucaryotic cells (Owens et al., 1987), and bacteria (Humphries et al., 1987) to surfaces. Molecular mobility of flexible molecules on the substratum surface sterically hinders the adhesion of bacteria, regardless of the chemical composition of cell surface adhesives. To investigate the effects of substratum molecular mobility and chemical composition on the kinetics and strength of adhesion, we have initiated studies using substrata which exhibit a homogenous surface consisting of specific functional groups.