In infiltration basins, such as in any kind of porous media, bacteria may form biofilms. When conditions induce destabilization of this biofilm, resulting colloids are transported by the hydraulic flow. Some studies have focused on the role played by these bacterial colloids in pollutants transport in soil. This study deals with the ability of Pseudomonas putida to retain zinc and investigates the facilitated transport of this metal. Batch and columns experiments have been carried out. Bacteria display a great affinity for zinc in batch experiments and facilitated transport have been highlighted in a small extent, for the moment. A scenario of stabilization/destabilization of the biofilm has been designed and may be employed for further investigations.