Controlling bacteria with light
A groundbreaking technique developed by Politecnico di Milano researchers is enabling scientists to control specific bacterial functions using light-sensitive materials. The Engineering Of bacteria to See light (EOS) project has pioneered a system that allows bacteria to sense light and convert light energy into electrical signals across their membranes without the need for any genetic modification.
This method is being explored as a promising solution to the growing global challenge of antibiotic resistance.
Its potential applications include developing next-generation antimicrobial platforms, where light is used to target resistant pathogens, and biocompatible, light-guided “bacterial robots” capable of delivering drugs to specific areas of the body, even those that are typically difficult to reach, such as the gastrointestinal tract.
Politecnico di Milano’s research team uses special photo-transducing molecules that irreversibly attach to the bacterial surface. When exposed to light, these molecules alter the electrical potential of the bacterial membrane.
This interplay between light and electrical signalling allows us to control key biological processes such as movement, biofilm formation, and antibiotic sensitivity. By manipulating the membrane potential on demand, we can influence antibiotic uptake and restore or even enhance the effectiveness of treatments against resistant strains.
Giuseppe Maria Paternò, Department of Physics, EOS project scientific coordinator
The team’s initial findings, published in The European Physical Journal Plus (Springer Nature), demonstrate that optomodulation, which is the light-induced modulation of electrical signals, directly affects the absorption of antibiotics.
The EOS project was funded under the Horizon Europe program with an ERC Starting Grant of 1.5 million euros.
Bertolotti, P., Gallinardi, F., Ghidoli, M. et al.
Photocontrol of bacterial membrane potential regulates antibiotic persistence in B. subtilis.
Eur. Phys. J. Plus 140, 336 (2025).