Adsorption of Flavobacterium breve and Pseudomonas fluorescens p17 on different metals:: Electrochemical polarization effect

The electrochemical polarization effect on early adsorption of Flavobacterium breve and Pseudomonas fluorescens P17 to platinum, titanium, stainless steel, copper, aluminium alloy and mild steel was studied. A welldefined peak characterized the bacterial adsorption dependence on externally applied potential. Maximal adsorption occurred in the potential range of -0.5 to 0.5V (SCE) for all tested metals. A shift of applied potential towards both a positive and a negative direction from the maximal adsorption potential (E-max,E-ad) was accompanied by a gradual decrease in bacterial adsorption. The extent of bacterial adsorption strongly depended on the nature of the metallic substratum and decreased accordingly as follows: platinum > titanium > stainless steel > aluminum alloy > carbon steel > copper. Adsorption on all tested metals was approximately two orders of magnitude higher with the relatively more hydrophobic F breve compared to the less hydrophobic P. fluorescens P17. The effect of electrochemical polarization on the initial stages of bacterial adsorption onto metallic substrata is further discussed.