Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts 02118.
Appl Environ Microbiol. 1987 Apr;53(4):782-6. doi: 10.1128/aem.53.4.782-786.1987.
H conductance in de-energized cells of Clostridium thermoaceticum and Clostridium acetobutylicum was determined from the rate of realkalinization of the medium after an acid pulse. In both organisms, cell membrane proton permeability was increased by fermentation end products and ionophores. In C. thermoaceticum, H conductance was increased by Na ions compared with K as counterions. In these cells, addition of Na, but not K, elicited efflux of H; H efflux was stimulated by SCN and decreased by various ionophores. We concluded that C. thermoaceticum possesses an electrogenic Na/H antiporter. In contrast, C. acetobutylicum cells did not have an electrogenic Na/H antiporter.
产醋热梭菌和丙酮丁醇梭菌去极化细胞中的 H 电导可通过酸脉冲后介质的再碱化速率来测定。在这两种生物体中，细胞膜质子通透性都可被发酵终产物和离子载体增加。与反离子 K 相比，产醋热梭菌中的 H 电导可被 Na 离子增加。在这些细胞中，Na 的添加而非 K 的添加会引起 H 的外排；H 的外排可被 SCN 刺激并可被各种离子载体抑制。我们得出结论，产醋热梭菌具有生电性 Na/H 反向转运蛋白。相比之下，丙酮丁醇梭菌细胞没有生电性 Na/H 反向转运蛋白。
