Project Description

Primary Supervisor - Professor Tom Clarke

Rewiring photosynthetic pathways in a purple bacterium.
There is an increasing need for biological solutions to challenges such as metal recovery and detoxification of organic compounds from industrial waste. Many microorganisms have been engineered to allow these processes to occur, but they typically require additional chemical substrates for energy to maintain the cell culture. Photosynthesis is a potential alternative energy source but rewiring metabolic pathways to use the energy of sunlight is often challenging.
The purple phototrophic bacteria Rhodopseudomonas palustris is a versatile organism that can switch between light driven iron oxidation and dimethylsulfoxide (DMSO) respiration in the absence of light. In principle, expression of these two pathways at the same time should allow for light driven iron and DMSO reduction, bypassing central metabolism. This project aims to deliver on this proof of principle, by engineering R. palustris and characterising the energetics of engineered reaction pathway both in vitro and in vivo. Molecular biology will be used to assemble plasmids for the expression of both pathways under phototrophic conditions. The novel PioAB complex iron oxidising complex will be extracted from R. palustris and characterised by Cryo-EM, while spectroscopy and spectrophotometry will be used to study electron transfer between the different component proteins. Once the pathway is confirmed in vitro, the ability of engineered R. palustris to oxidise both iron and reduce DMSO will be explored.
Once this engineered strain has established as a proof-of-concept, there will be the opportunity to adapt the pathways to utilise other metals and more industrially relevant organic materials, depending on the interests of the student.

Burton JAJ, Edwards MJ, Richardson DJ, Clarke TA
Electron Transport Across Bacterial Cell Envelopes. (2025)
Annu Rev Biochem. 94(1):89-109. doi: 10.1146/annurev-biochem-052621-092202.

The Norwich Research Park Biosciences Doctoral Training Programme (NRPDTP) is offering fully funded studentships for October 2027 entry. The programme offers postgraduates the opportunity to undertake a 4-year PhD research project whilst enhancing professional development and research skills through a comprehensive training programme. You will join a vibrant community of world-leading researchers. All NRPDTP students undertake a three-month professional internship placement (PIPS) during their study. The placement offers exciting and invaluable work experience designed to enhance professional development. Full support and advice will be provided by our Professional Internship team.

This project has been shortlisted for funding by the NRPDTP. Shortlisted applicants will be interviewed on the 2nd, 3rd and 4th February 2027.

Visit our website for further information on eligibility and how to apply: https://biodtp.norwichresearchpark.ac.uk.

Our partners value diverse and inclusive work environments that are positive and supportive. Students are selected for admission without regard to gender, marital or civil partnership status, disability, race, nationality, ethnic origin, religion or belief, sexual orientation, age or social background.

To maximise accessibility and attract students from underrepresented groups to our programme we have introduced bespoke templates for applicant Personal and Research statements which will enable every applicant to fully represent themselves through providing suitable examples and evidence. These forms are on the NRPDTP website and must be used for these sections of the application form.

Entry Requirements

At least UK equivalence Bachelors (Honours) 2:1. English Language requirement (Faculty of Science equivalent: IELTS 6.5 overall, 6 in each category).

Funding

This project is awarded with a 4-year Norwich Research Park Biosciences Doctoral Training Partnership PhD DTP studentship. The studentship includes payment of tuition fees (directly to the University), a stipend to cover living expenses (2026/27 stipend rate: £21,805, and a Research Training Support Grant of £5,000pa for each year of the studentship.

References

Cyanobacterial redox carriers support photosynthesis in a purple phototrophic bacterium.
Bowie AGM, Hitchcock A, Proctor MS, Martin EC, Swainsbury DJK, Hunter CN.
Biochem J. 2025 13:1123-44. doi: 10.1042/BCJ20253114. Electron Transport Across Bacterial Cell Envelopes.
Burton JAJ, Edwards MJ, Richardson DJ, Clarke TA. Annu Rev Biochem. 2025 Jun;94(1):89-109. doi: 10.1146/annurev-biochem-052621-092202. Structures of Rhodopseudomonas palustris RC-LH1 complexes with open or closed quinone channels.
Swainsbury DJK, Qian P, Jackson PJ, Faries KM, Niedzwiedzki DM, Martin EC, Farmer DA, Malone LA, Thompson RF, Ranson NA, Canniffe DP, Dickman MJ, Holten D, Kirmaier C, Hitchcock A, Hunter CN.
Sci Adv. 2021 13: doi: 10.1126/sciadv.abe2631. His/Met heme ligation in the PioA outer membrane cytochrome enabling light-driven extracellular electron transfer by Rhodopseudomonas palustris TIE-1.
Li DB, Edwards MJ, Blake AW, Newton-Payne SE, Piper SEH, Jenner LP, Sokol KP, Reisner E, Van Wonderen JH, Clarke TA, Butt JN. Nanotechnology. 2020 Aug 28;31(35):354002. doi: 10.1088/1361-6528/ab92c7 Protein Interactions in Rhodopseudomonas palustris TIE-1 Reveal the Molecular Basis for Resilient Photoferrotrophic Iron Oxidation.
Trindade IB, Firmino MO, Noordam SJ, Alves AS, Fonseca BM, Piccioli M, Louro RO. Molecules. 2023 Jun 13;28(12):4733. doi: 10.3390/molecules28124733.

Rewiring photosynthetic pathways in a purple bacterium (CLARKE_U27DTP)

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Project Description

Entry Requirements

Funding

References