- Identify extremophile microorganisms that fix greenhouse gases from the atmosphere
- Establish biocatalytic tools for Carbon Capture and Storage
- Develop new approaches for designing biohybrid catalysts for Carbon Capture and Catalytic Hydrogenation
Global warming caused by greenhouse gases like CO2 is a major global concern. Understanding the complex natural cycling of greenhouse gases is crucial to address the urgent climate crisis. The cycling of key greenhouse gases, like CO2, involves microorganisms that fix CO2 and release methane. Some microorganisms also utilise intermediates like carbon monoxide (CO) and dihydrogen (H2) in their metabolism. The metabolic pathways of these microorganisms involve specialised gas-processing enzymes, which are key to understand how greenhouse gases can be fixed from the atmosphere, and directly related to biogeochemical cycles, global warming, and climate change.
This project aims to develop new biohybrid catalysts by utilising biological scaffolds to host or bind synthetic catalysts. Biohybrid catalysts hold a lot of potential to fix greenhouse gases from the atmosphere and for carbon capture and storage (CCS). They are sustainable, as they are biodegradable and produced from naturally abundant materials. Biohybrid catalysts combine the advantages of synthetic chemistry with the benefits of natural enzymes (specificity/selectivity). However, biohybrid catalysts based on protein scaffolds from ‘regular’ organisms are generally restricted to ambient conditions, limiting their scope for application in biotechnology.
Extremophiles are organisms that live under extreme environments, such as under high pressures and extremes of temperature and pH. Evolution of organisms under extreme conditions has optimised their enzymes for exquisite performance under harsh conditions. This project aims to make use of the unique properties of extremophiles by mining their genomes in search of ideal scaffolds for synthetic catalysts to build biohybrid catalysts that can work under non-ambient conditions.
This project will encompass three main stages. Stage 1 will focus on searching for (i) small metalloproteins from extremophiles including enzymes active for CO2 reduction and/or H2 conversion and (ii) small proteins like ferredoxins and cytochromes. In Stage 2, the identified enzymes/proteins will be produced and characterised to test their stability under extreme conditions. In Stage 3, the produced enzymes will be tested as candidates for binding synthetic catalysts. Overall, this project will develop new approaches for environmental biotechnology to fix greenhouse gases from the atmosphere and for CCS by building biohybrid catalysts using biological scaffolds from extremophiles.
Figure 1: Extremophilic microbes have developed several physiological and molecular strategies to survive and grow in extreme environments. This figure is a graphical abstract describing the key steps of the project.
HostUniversity of Leicester
- Climate and Environmental Sustainability
The research plan breaks down as follows: 1) Analysis of databases (e.g. metagenomic databases) will be done to identify homologues of well–known hydrogenases (enzyme that catalyse H2 conversion in nature), CO dehydrogenases (enzyme that catalyse the CO2/CO interconversion in nature), as well as ferredoxins and cytochromes that are present in extremophiles. 2) The organisms of interests will be obtained and cultured in the lab to purify the enzymes. 3) In parallel with the step 2, the enzymes will be produced heterologously (e.g. inside E. coli or other hosts). 4) The structure/function of the enzymes will be studied via an integrated approach combining electrochemical, spectroscopic, structural and computational methods. 5) The produced enzymes will be tested as candidates for binding/hosting synthetic catalysts and the reactivity of the biohybrid catalysts will be explored.
Training and skills
Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.
The student will benefit from this highly multidisciplinary project co-supervised by Rodriguez-Macia and Kilpatrick. The student will acquire crucial lab-based and interpersonal skills from the supervisory team and their research group members. They will be trained in molecular biology, reconstitution strategies, structural biology, spectroscopy, electrochemistry and synthetic chemistry.
The student will also be able to attend various modules available in the Chemistry degree, e.g. Earth System Science by Dr Ball, and Advanced Structure Determination by the PIs Dr Rodriguez-Macia and Dr Kilpatrick.
The supervisors will encourage participation at conferences and outreach activities.
Further details on how to contact the supervisor for this project and how to apply for this project can be found here:
To apply to this project:
- You must include a CENTA studentship application form, downloadable from: CENTA Studentship Application Form 2024.
- You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.
- Please submit your application and complete the host institution application process via: https://le.ac.uk/study/research-degrees/funded-opportunities/centa-phd-studentships. Please scroll to the bottom of the page and click on the “Apply for NERC CENTA Studentship” button. Your CV can uploaded to the Experience section of the online form, the CENTA application form 2024 can be uploaded to the Personal Statement section of the online form. Please quote CENTA 2024-L3-CENTA2-CHEM3-RODR when completing the application form.
Applications must be submitted by 23:59 GMT on Wednesday 10th January 2024.
More information about the supervisory team and the School of Chemistry at the University of Leicester can be found here: https://le.ac.uk/chemistry; https://rodriguezmacia.wixsite.com/labgroup; https://www.kilpatrickgroup.uk/
Analysis of databases to identify proteins of interest, order cultures, genes, cloning, initial protein production attempts.
Purify the enzymes from native and heterologous hosts. The structure/function of the produced enzymes will be studied.
Synthetic catalysts produced, enzymes tested for binding/hosting catalysts, reactivity explored. Write a paper/s (possible two papers, one about the new identified proteins from extremophiles and one with the biohybrid catalysts) with the student as first named author.
The results of this project will provide new insights into the microbial processes driving the biogeochemical cycling of CO and H2 and contribute to develop new environmental biotechnological approaches to overcome the global warming and climate change.
Stein, LY. (2020) ‘The long-term relationship between microbial metabolism and greenhouse gases’ Trends Microbiology 28 (6), pp. 500-511.
Tiedje, JM, Bruns, MA, Casadevall, A, Criddle, CS, Eloe-Fadrosh, E, Karl, DM, Nguyen, NK, Zhou, J. (2022) ‘Microbes and climate change: a research prospectus for the future’ mBio 13 (3), e0080022.
Greening, C, Boyd, E. (2020) ‘Editorial: Microbial hydrogen metabolism’ Frontiers in Microbiology 11, pp. 56.
Diender, M, Stams, AJM, Sousa, DZ. (2015) ‘Pathways and bioenergetics of anaerobic carbon monoxide fermentation’ Frontiers in Microbiology 6, pp. 1275.