Extracellular Fluorescence Recording of BacFlash Dynamics Reveals Two Distinct Modes of Proton Extrusion

protons per cell per second-a parameter not previously reported. Further analysis under alkaline conditions uncovered two kinetically distinct forms of BacFlash, differing by over an order of magnitude in proton efflux rates and durations. These dynamic patterns were further modulated by ultraviolet stimulation. Our findings demonstrate that BacFlash is not a stochastic fluctuation but a tunable, metabolically linked signaling process. Moreover, our ability to quantify proton translocation at single-cell resolution opens new avenues for mechanistic studies of bacterial bioenergetics and antimicrobial strategies targeting proton-driven physiological processes.