Аннотация:Natronophilic bacteria Thioalkalivibrio versutus are the soda lake extremoalkaliphiles. They are the first living organisms which were recently demonstrated to dispose of the operative sodium (Na+)-translocating cytochrome-c oxidase. We found experimental conditions to monitor motility of the bacterial cells on the semi-fluid agar plates. Amiloride was shown to have an inhibitory effect on the bacterial motility that suggests the bacteria motile by the Na+-motive flagella. We conclude that in Tv. versutus the energetic Na+-cycle operates which is presented at least by the electrochemical potential generator, Na+-translocating cytochrome oxidase, and the electrochemical potential consumer, Na+-motive flagella.