Probing the electrochemical dynamics of germination in Bacillus Subtilis spores

Lead Research Organisation: University of Warwick
Department Name: Warwick Medical School

Abstract

Programme overview:
This MRC-funded doctoral training partnership (DTP) brings together cutting-edge molecular and analytical sciences with innovative computational approaches in data analysis to enable students to address hypothesis-led biomedical research questions. This is a 4-year programme whose first year involves a series of taught modules and two laboratory-based research projects that lead to an MSc in Interdisciplinary Biomedical Research. The first two terms consist of a selection of taught modules that allow students to gain a solid grounding in multidisciplinary science. Students also attend a series of masterclasses led by academic and industry experts in areas of molecular, cellular and tissue dynamics, microbiology and infection, applied biomedical technologies and artificial intelligence and data science. During the third and summer terms students conduct two eleven-week research projects in labs of their choice.


Project:
Several species of bacteria sporulate in harsh conditions but can germinate back to activity when their environment becomes habitable again. These spores have a wide variety of uses ranging from probiotics to bioterror agents causing anthrax, and are problematic to inactivate in the food industry, thus an important topic of biomedical research. The dormant spores have a tough multi-layered shell resistant to heat, radiation, extreme pH, and toxins allowing them to survive in a vegetative state for years.
Nutrients in the environment trigger germination, which recovers the spores to active bacteria. Though there are genes known to be involved in germination, it is unknown how they can sense such stimuli and activate the cascade of mechanisms. We hypothesise that germination is mediated by electrochemical features, including ions (e.g. calcium, sodium, etc.), membrane voltage and pH. A recent paper from the Asally lab demonstrated that spore formation was quality controlled by charged particles. We propose to use the same techniques to investigate the electrophysiology of germination in the bacteria Bacillus subtilis, and improve the quantification by scanning electrochemical probe microscopy (SEPM). This is a multifunctional imaging platform that uses glass probes with a tip diameter of 10-100 nm which scans samples and measure the flow of ions and redox properties with high precision.
This project will require the student to use microbiological techniques to work with the spores as well as investigate mutants with defects in genes involved in germination. The student will be trained to use various the SEPMs and the software used to control the microscopes which requires modifying hardware and software for optimising the setup. Additionally, the student will be using statistical packages to analyse data and simulation packages for interpreting SEPM data. Hence, this project will cover the quantitative and interdisciplinary skills training themes set out by the MRC.

Publications

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