Do bacteria use electricity?
Yes. Bacteria are tiny living cells, but they still rely on electrical differences across their membranes. We study how these electrical states change, what they do, and whether they can be measured and controlled.
What is bioelectricity?
Electricity in living things is not limited to nerves, brains or muscles. Every living cell keeps different charged particles, called ions, at different concentrations inside and outside its membrane. This creates an electrical voltage across the membrane.
This voltage is called the membrane potential. It is a basic feature of life. Cells use it to move nutrients, produce energy, sense changes in their surroundings and control many other processes.
Bacteria have membrane potentials too. Because bacteria provide a useful system for asking a broad question: what do living cells do with electricity?
Why does electricity matter?
A bacterial cell is separated from the outside world by a thin membrane. The cell actively moves ions across this membrane and controls which ions are allowed to cross. The resulting electrical and chemical differences store energy.
Bacteria use this stored energy to make ATP, transport molecules, move, maintain their internal environment and respond to changing conditions. The electrical state of the membrane is therefore not just a side effect of life: it is closely connected to how the cell functions.
This links to important processes in our society - including biofilm formation, antimicorbial resistance and biotechnology.
Can bacteria communicate electrically?
Bacteria are often imagined as isolated single cells, but many live in communities. They can influence one another using chemicals, metabolites, direct contact and changes to their shared environment.
Electrical interactions provide another possibility. In some bacterial biofilms, ion movements can alter the local electrical environment and affect neighbouring cells. Work on Bacillus subtilis, for example, has shown that potassium-channel activity can contribute to signals that travel across a community.
This does not mean that bacteria have brains or neurons. The comparison is useful only at a more basic level: both bacterial cells and neurons use ions and membrane voltage. The interesting scientific question is how far similar physical principles can produce very different biological behaviours.
Can we measure and control bacterial electricity?
Measuring electrical activity in a bacterium is difficult because bacterial cells are much smaller than the cells usually studied in classical electrophysiology. Instead of placing an electrode inside every cell, researchers often use fluorescent molecules, microscopy and controlled perturbations to infer changes in membrane potential.
We are also interested in going beyond measurement. If an electrical state is important for cell behaviour, can we deliberately change that state? We use electrical, chemical and optical approaches to perturb membrane potential and observe how cells respond.
This connects fundamental biophysics with engineering biology: understanding a biological state is one step, but being able to measure, predict and control it opens the possibility of using that state as an engineering variable.
What do we still not understand?
Many basic questions remain open. How is membrane voltage generated and regulated in different bacteria? Which ions carry electrical responses? When does an electrical change contain useful information for the cell? How does one cell's electrical state affect another? And can these dynamics be used to detect or control bacterial behaviour?
These questions sit between microbiology, biophysics and engineering biology. Bacteria give us a comparatively simple living system in which to test them experimentally.
A few useful terms
Bioelectricity is the study of electrical phenomena in living systems. Membrane potential is the voltage difference across a cell membrane. Electrophysiology is the study of electrical properties and electrical activity in living cells and tissues. When we study these phenomena in bacteria, we often use the term bacterial electrophysiology.
Want to go deeper?
The papers below discuss bacterial membrane potential and electrical signalling in more technical detail.