Supervisors: Simon Avery (PI) (Life Sciences, UK), Paul Dyer (Life Sciences, UK), Rebecca Ford (Biosciences, UK), Cormac O’Shea (Biosciences, UK).
Based in School of Life Sciences, University Park Campus, UK
Developing novel, sustainable sources of high quality, digestible protein for food represents a major challenge in combatting both malnutrition and metabolic disease in the face of population growth and climate change. It is not only the quantity of protein available that is important but also its quality, which can be deficient in many diets. Protein quality is defined by its essential amino acid (EAA) content and digestibility. This PhD studentship will manipulate the error-rate of translation, a key step in protein synthesis by organisms, as a novel tool to improve the EAA composition of future dietary-protein sources. Work to date in our laboratories has focused on fungi and this project will capitalise on industry involvement of Quorn Foods by focusing on mycoprotein from Fusarium venenatum as the main exemplar. The Quorn fungus has a high protein content and bioavailability and is also amenable to genetic and physiological manipulation. It should be possible to extrapolate the principles established with this system to other protein sources.
The main project tasks will be:
1. Assess the effects on EAA composition of genetic and physiological manipulations known to affect translation error, utilising the model fungus (yeast) Saccharomyces cerevisiae. These will include manipulations known to increase general translation error-rate as well as manipulations tailored to alter frequency of particular EAA substitutions. Impacts on growth and protein yields will be monitored, including in parallel studies where protein EAA composition will be altered by simple growth in EAA supplemented media, to which fungi are very amenable.
2. The above approaches will allow successful manipulations to be selected and prioritised for application to the Quorn fungus. Impacts on this organism’s EAA composition and protein yield will be compared for the different manipulations. In addition, the project will investigate potential for improving Quorn texture. Currently, the hydrophobic properties of the fungus demand the addition of egg albumen as a binding agent, making most Quorn products non-vegan. The project will compare the impacts of tailored translation-fidelity manipulations with targeted mutations on fungal hydrophobicity, with the prospect of a truly vegan mycoprotein product without the need for other additives.
3. The impacts of the above research on nutritional quality will be assessed according to the match between achieved EAA profiles and human EAA requirements. This will be complemented with measurements of digestibility/bioavailability and sensory perception of the modified mycoprotein.
As the molecular machinery governing translation fidelity is highly conserved through evolution, it is anticipated that success in this project will pave the way for extending the novel approach to improve quality of other future-protein sources. This will help support food security through sustainable production of dietary protein into the future.
The project will provide outstanding training opportunities for the successful candidate, with supervision by a cross-disciplinary and cross-sector team. Training will be provided in molecular genetics tools as applied to yeast and the Quorn fungus, interrogation of translation fidelity and EAA profiling, complemented by bioavailability and sensory perception of modified protein sources. The student will benefit from access to state-of-the-art facilities and involvement in a dynamic research environment. There will be opportunities for travel and training credits for transferable skills relevant to diverse future-career destinations.
This PhD will be based primarily in the School Life Sciences, University of Nottingham. For further information, please contact Professor Simon Avery: [email protected]