Probing the dynamics of the proton-motive force in *E. coli*


Flagellar motility in Escherichia coli is driven by the proton motive force (PMF); exogenous control of PMF could allow the use of flagellated bacteria as microactuators. Following recent work, we have engineered cells to express a fluorescent membrane protein (proteorhodopsin optical proton sensor, PROPS) to report PMF, allowing real-time monitoring of the membrane potential and its periodic depolarizations. We show that the timing characteristics of these fluctuations can be controlled by adjusting the availability of oxygen, suggesting a potential scheme of PMF control.

Proceedings of IEEE SENSORS Conference