Evidence of Chemical Wave–Electric Field Interaction in Bacterial Cells

Jie-Pan Shen^1*, Chia-Fu Chou¹

¹Institute of Physics, Academia Sinica, Taipei City, Taiwan

* Presenter:Jie-Pan Shen, email:jpshen@as.edu.tw

The validity of charge neutrality assumption in living bacteria is questioned due to imbalanced charge distribution and bounded cellular space. Based on Poisson-Nernst-Planck equations, we provide numerical evidence that the diffuse layer may extend up to 200 nm, far larger than that given by charge neutrality assumption, subject to the intracellular cation/anion ratio, and substantial intracellular field strength of 10 ~ 15 mV⁄μm may arise. Accordingly, chemical waves, such as Min-protein oscillator in E. coli, traversing across the intracellular field are considered to undergo chemical wave–electric field interaction. Experiments using bacteria expressing Min-protein system is employed to confirm the derived dispersion relation, which explains the oscillation frequency modulations constraining the permitted wave modes, and further verified through the experiments of nucleoid perturbations via antibiotic treatments. The implications of an indispensable role of wave–field interactions may go beyond the formation and modulation of bacterial Min-protein oscillator to other chemical wave systems.

Keywords: extension of diffuse layer, chemical wave–electric field interaction, biological oscillator, dynamic pattern, single cell biophysics