pH homeostasis predictions by Francisella model i RS605. Robustness diagrams depict the effect of proton flux and ammonium ion flux on growth rates of Francisella as a function of the environment. Left panels show H+ ion effects, while the panels on the right show NH4+ ion effects. Distinct trajectory types are observed in all media. Media used were Chamberlain minimal medium (Chamberlain), Chamberlain medium supplemented with glucose (Chamberlain +glu), and host cell conditions (as described in Additional file 1 [S3]).