Project Outline

Background

Recent publications in high-impact journals indicate growing interest in bacterial electrophysiology (1–4). Studies, including by our group, have shown that bacterial membrane potential can exhibit non-linear spiking and rhythmic oscillations which function as bioelectrical signals during antibiotic exposure, cellular differentiation and biofilm formation (5).

The ability to control bacterial membrane potential, with precision in space and time, will provide a new window to control and engineer bacterial functions. It could also open a new avenue in synthetic biology and engineering biology to control physiological dynamics of cells. However, bacterial electrophysiology is a newly emerging field and there has been limited developments of membrane-potential modulation technologies.

Project Aim

This PhD project will develop genetically encoded optical modulation technology for bacterial electrophysiology. The project will also use a photoswitch azobenzene for modulating bacterial membrane potential. Using the optical modulation tools, we aim to alter biofilm formation, spore formation, antibiotic susceptibility and growth rates.

Methods

The project will offer the interdisciplinary training opportunity for experimental and analytical skills in biophysics, neuroscience and microbiology. We will apply the optogenetic techniques in neuroscience for the application with bacteria. The key methods to be used include molecular biology, microbiology, fluorescence microscopy, patterned optical stimulation, computational modelling, and quantitative image analysis (Python and imageJ). The project offers an aspiring student to pioneer the field of bacterial electrophysiology and bioelectricity.

References

1. K. Kikuchi, et al., Electrochemical potential enables dormant spores to integrate environmental signals. Science (80-. ). 378, 43–49 (2022).
2. A. Prindle, et al., Ion channels enable electrical communication in bacterial communities. Nature 527, 59–63 (2015).
3. X. Jin, et al., Sensitive bacterial V m sensors revealed the excitability of bacterial V m and its role in antibiotic tolerance. Proc. Natl. Acad. Sci. 120, 2017 (2023).
4. J. P. Stratford, et al., Electrically induced bacterial membrane-potential dynamics correspond to cellular proliferation capacity. PNAS 116, 9552–9557 (2019).
5. J. M. Benarroch, M. Asally, The Microbiologist’s Guide to Membrane Potential Dynamics. Trends Microbiol. 28, 304–314 (2020).

Techniques

• Molecular cloning
• Time-lapse Fluorescence microscopy
• Optical stimulation
• Plate reader assays
• Biofilm assay
• Sporulation assay
• Quantitative image analysis
• Computational modelling