Sodium Energetic Cycle in the Natronophilic Bacterium Thioalkalivibrio versutusстатьяИсследовательская статья
Статья опубликована в высокорейтинговом журнале
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 4 марта 2022 г.
Аннотация:As inhabitants of soda lakes, Thioalkalivibrio versutus are halo- and alkaliphilic bacteria previously shown to respire with the first-demonstrated Na+-translocating cytochrome-c oxidase (CO). The enzyme generates a sodium-motive force (delta s) as high as -270 mV across the bacterial plasma membrane. However, in these bacteria, operation of the possible delta s consumers has not been proven. We obtained motile cells and used them to study the supposed Na+-energetic cycle in these bacteria. The resulting motility was activated in the presence of the protonophore 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), in line with the same effect on cell respiration, and was fully blocked by amiloride - an inhibitor of Na+-motive flagella. In immotile starving bacteria, ascorbate triggered CO-mediated respiration and motility, both showing the same dependence on sodium concentration. We concluded that, in T. versutus, Na+-translocating CO and Na+-motive flagella operate in the Na+-energetic cycle mode. Our research may shed light on the energetic reason for how these bacteria are confined to a narrow chemocline zone and thrive in extreme conditions of soda lakes.