|Abstract or Summary
- Pseudomonas aeruginosa is a bacterial pathogen that can cause grave and sometimes chronic infections in patients with weakened immune systems and cystic fibrosis. It is suspected that specialized sodium pumps in the cellular membrane are crucial for the organism’s survival and growth, since many cellular processes rely on the maintenance of Na+ and H+ trans-membrane gradients. This study focuses on the primary and secondary proton and/or sodium pumps Mrp, Nuo, NhaB, NhaP, and NQR for study in P. aeruginosa. Using P. aeruginosa mutants with gene deletions for the listed sodium pumps, we investigated the impact of each sodium pump’s absence on the overall growth, biofilm formation, motility, and weak acid tolerance of the organism. We found that the absence of some, but not all, of the sodium pumps have a deleterious effect on the different phenotypes of P. aeruginosa. The absence of the Mrp sodium pump was clearly significant in the organism’s ability to survive and function in environments of higher pH and sodium concentrations, while the absence of Complex I, which is encoded by the nuo gene, had some consistent impact on the organism’s growth regardless of the pH and sodium concentration of the environment. The sodium pumps Nqr, NhaB, and NhaP had minimal or no significance.