Alexander Scott

How does low-temperature plasma damage the bacterial outer membrane?

About me

I did my undergraduate degree at the University of York, completing the 4-year Integrated Masters programme in Physics. Throughout my time as an undergrad, my main interests were split between biophysics and plasma physics. After a summer internship with Mark Leake and Adam Wollman in York, looking at molecular biosensors, and my Masters project with Howard Wilson (YPI) – “Stability analysis of small scale spherical tokamaks for component testing”, I decided a future in either biophysics or low-temperature plasmas was for me. With York excelling in both research areas, and already in love with the city, it was the perfect place to stay for my PhD. I thrive on the challenge of working in an interdisciplinary research area, and a PhD research project based in Biology will provide the challenge I am looking for.

My project

Global challenges include microbial infections and bacterial contamination of surfaces and the environment. With antimicrobial resistance becoming an increasing concern, alternative approaches need to be developed to combat infection. One of these is Low-Temperature Plasmas (LTPs) – formed when high voltage is applied to a gas flow. The chemical properties of the LTP offers great promise as an antibiotic-free therapeutic for combating bacterial infection associated with wounds and skin ulcers, and are another potential weapon in the arsenal to combat antimicrobial resistance. However, there are key biological and physical questions remaining that need to be addressed to enhance the development of LTP for use in society. For example, the physical mechanisms whereby the reactive oxygen and nitrogen species in LTP damage the bacterial envelope and render a cell non-viable is very poorly understood. To further develop and optimise the use of LTP, a greater understanding of the molecular mechanisms whereby LTP imparts its bactericidal effect is required, and this will be the focus of this project.

My project will investigate how an oxygen-based LTP affects the outer-membrane (OM) of E.coli using a single-cell level approach. I will be using different strains of E.coli to determine which components of the OM are affected by the LTP (such as the lipopolysaccharide or OM porin proteins). After fluorescently labelling specific OM targets in the cell envelope, I will employ time-lapse imaging post LTP exposure to determine if any morphological differences can be observed, and to identify potential phenotypic traits of non-viable cells and viable persister cells.  With knowledge of these processes, the ability to customise a plasma treatment to prevent damage to abiotic surfaces whilst rendering the microbes non-viable is possible.


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