Metallome of Pseudomonas aeruginosa: a role for siderophores.

In this paper, we describe the total metal composition (metallome) of Pseudomonas aeruginosa. Inductively coupled plasma atomic emission spectroscopy analyses showed that P. aeruginosa cells concentrate each metal of the metallome from the extracellular media with different efficiencies. Growth in nutrient-restricted media did not substantially affect the overall profile of the metallome; however, the uptake of some metals was strongly stimulated, showing the high potential of some metal acquisition pathways to adapt to changing growth conditions. We also investigated the role of the two major siderophores produced by P. aeruginosa, pyoverdine and pyochelin, in iron uptake and more generally in metallome homeostasis. In addition to their role in iron acquisition, siderophore production also significantly prevented the accumulation of toxic metals in P. aeruginosa cells, thus preserving the equilibrium of the metallome in a polluted environment.