Electrochemical Communication in Bacterial Biofilms: A Study on Potassium Stimulation and Signal Transmission

TL;DR

This work investigates the response of bacterial biofilms to artificial potassium concentration stimulation, and analyzes the output signals when biofilm regions are subjected to different input signal types and explore their impact on biofilm growth.

Abstract

Electrochemical communication is a mechanism that enables intercellular interaction among bacteria within communities. Bacteria achieves synchronization and coordinates collective actions at the population level through the utilization of electrochemical signals. In this work, we investigate the response of bacterial biofilms to artificial potassium concentration stimulation. We introduce signal inputs at a specific location within the biofilm and observe their transmission to other regions, facilitated by intermediary cells that amplify and relay the signal. We analyze the output signals when biofilm regions are subjected to different input signal types and explore their impact on biofilm growth. Furthermore, we investigate how the temporal gap between input pulses influences output signal characteristics, demonstrating that an appropriate gap yields distinct and well-defined output signals. Our research sheds light on the potential of bacterial biofilms as communication nodes in electrochemical communication networks.

Figures (6)

• Figure 1: Signal propagation in bacterial biofilm.
• Figure 2: Potassium oscillations due to metabolic stress. Supplementing glutamate to the interior cells of biofilm quenches the oscillation.
• Figure 3: Channel impulse response in terms of membrane potential and extracellular potassium concentration with time when an impulse of potassium signal with magnitude $K_\mathrm{input}= 100\ mM$ is given at $x=0$ at time $t=5$ hour.
• Figure 4: Extracellular potassium concentration in biofilm at $x=10 mm$ when the input to the biofilm is a series of impulses at time $t=5,\ 10$ and $15$ hour.
• Figure 5: Variation of the extracellular potassium concentration across space and time. We can also see that potassium signals from the interior cells stop the biofilm's growth for some time. The white line represents the boundary of the biofilm.