https://doi.org/10.1140/epjp/s13360-025-06263-7
Regular Article
Photocontrol of bacterial membrane potential regulates antibiotic persistence in B. subtilis
1
Center for Nanoscience and Technology, Istituto Italiano di Tecnologia, Via Rubattino 81, 20134, Milan, Italy
2
Department of Electronics, Information and Bioengineering, Politecnico di Milano, Via Ponzio 34/5, 20133, Milan, Italy
3
Department of Biotechnology and Bioscience, Università di Milano – Bicocca, Building U3 – BIOS, Piazza della Scienza 2, 20126, Milan, Italy
4
Department of Chemistry, Materials and Chemical Engineering, “Giulio Natta” Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133, Milan, Italy
5
Department of Physics, Politecnico di Milano, Piazza Leonardo Da Vinci 32, 20133, Milan, Italy
a
giuseppemaria.paterno@polimi.it
Received:
7
March
2025
Accepted:
24
March
2025
Published online:
24
April
2025
Bacterial persistence and resistance to antibiotics pose critical challenges in healthcare and environmental contexts. Recent studies revealing that bacteria possess a dynamic electrical membrane potential open new avenues for influencing bacterial behaviour and drug susceptibility. In this work, we present a novel light-responsive strategy to modulate bacterial antibiotic persistence using Ziapin2, an azobenzene photoswitch previously shown to alter bacterial membrane potential. We selected two broad-spectrum antibiotics with distinct modes of action: Kanamycin, which requires cytosolic uptake to inhibit protein synthesis, and Ampicillin, which targets cell wall polymerization at the cell envelope, to probe the role of membrane potential in antibiotic efficacy. Our findings show that when Bacillus subtilis is exposed to Kanamycin and Ziapin2, photoactivation (470 nm) significantly impacts bacterial viability: under illumination, the previously lethal effects of Kanamycin are markedly reduced, suggesting that membrane potential changes drive altered antibiotic uptake or intracellular accumulation. In contrast, Ampicillin-treated samples remain largely unaffected by light-induced membrane modulation, consistent with its action at the external cell envelope. Taken together, these results indicate that membrane potential manipulation can selectively influence the activity of antibiotics whose intracellular uptake is critical to their function. This proof-of-concept study underscores the potential of non-genetic, light-based interventions to modulate bacterial susceptibility in real time. Future work will expand this approach by exploring additional antibiotic classes and novel azobenzene derivatives, ultimately advancing our understanding of bacterial bioelectric regulation and its applications in antimicrobial therapies.
© The Author(s) 2025
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