The enigma of the alkaliphile

Alkaliphilic bacteria provide a model system in which to test the basic principles of the chemiosmotic theory. The proton-motive force (delta mu H +) in these bacteria under alkaline conditions appears to be too low to power ATP synthesis assuming normal stoichiometry and a normal H+/F1F0 ATPase. Current data suggest that these bacteria might obviate the problems by harnessing a sodium-motive force (delta mu Na+).