Characterization of the Bacillus subtilis motile system driven by an artificially created proton motive force.
Transient swimming was induced in energy-depleted cells of Bacillus subtilis by an artificial proton motive force, which was created by valinomycin addition and a pH reduction. This system did not require any ions except protons in the medium. The size of the induced motility was strongly influenced by changes in the size of either the K+ diffusion potential or the pH gradient. A rough estimation indicated that a proton motive force higher than -100 mV was required for induction of translational swimming of the cell. Corresponding with the transient appearance of swimming, a rapid but transient efflux of K+ and influx of H+ were observed. With decreases in the rate of H+ influx, the amount of motility decreased. A rate of H+ influx higher than 0.2 mumol/s per ml of cell water gave translational swimming. These results suggest direct coupling of H+ influx to rotation of bacterial flagella.
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D001412:Bacillus subtilis / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology; D006859:Hydrogen / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009068:Movement; D011188:Potassium / Q000378:metabolism*; D011522:Protons; D014634:Valinomycin / Q000494:pharmacology
D011522:Protons; D014634:Valinomycin; D006859:Hydrogen; D000255:Adenosine Triphosphate; D011188:Potassium; D002118:Calcium