BACTERIAL CHEMOATTRACTANT PROPERTIES OF METAL-IONS FROM DISSOLVING ELECTRODE SURFACES

Bacterial chemotaxis of a marine Pseudomonas induced by transition met al ion concentration gradients has been demonstrated. It is shown that Cu(II) and titanium ions are strong chemo-attractants providing a lon g range recognition mechanism for the colonization of corroding surfac es of engineering materials, The effect of titanium ions is particular ly unusual as strong chemotaxis has also been observed with aqueous so lutions saturated with solid TiO2. A diffusional model using a variabl e bacterial diffusion coefficient has been employed to evaluate the mo vement of bacterial populations. The non-linear diffusional problem ha s been simulated using a simplified finite differences approach. A val ue of 1.5 x 10(-5) cm(2) s(-1) for the apparent bacterial diffusion co efficient (or random motility coefficient) has been calculated.