Photo-controlled bacteria – Project EOS. Credit: Politecnico di Milano – Department of Physics. CC BY-NC-ND.
New research is looking to control bacteria with light, leading to improvements in tackling antibiotic resistance and developing ‘bacterial robots’.
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.
Photo-transducing molecules
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.
Department of Physics professor and EOS project scientific co-ordinator Giuseppe Maria Paternò said: “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.”
The team’s initial findings, demonstrate that optomodulation, which is the light-induced modulation of electrical signals, directly affects the absorption of antibiotics.
Paternò said: “Using a photosensitive molecule called Ziapin2, the researchers altered the membrane potential of Bacillus subtilis, modulating the action of antibiotics such as Kanamycin (which acts within the cell) and Ampicillin (which targets the cell wall).
“Under blue light (470 nm), the effectiveness of Kanamycin was significantly reduced, suggesting that membrane potential plays a crucial role in the drug’s uptake.
“Ampicillin, on the other hand, retained much of its efficacy under illumination.”
The research is published in The European Physical Journal Plus.
