IAP-25-091
Mineral entrapment within protocells: key to the origin of life?
Before complex cellular life evolved, there must have been something simpler; a transition between geochemistry and biology. Membrane-bound ‘protocells’ (membrane-bound vesicles composed of simple abiotic chemical such as fatty acids that hosted primitive metabolic processes allowing them to grow and replicate and ultimately store and copy genetic information) appear likely candidates to have enabled this transition.
In this project you will investigate the interactions of fatty acid-based vesicles with minerals likely to have been present on the early Earth to gain insight into how the first protocells may have evolved. Prior research has primarily focused on the interactions of fatty acid vesicles with minerals outside their membranes. Here you will entrap relevant redox active minerals within fatty acid vesicles and determine if and how key abiotic reactions and their products relevant to the start of metabolism (carbon fixation, nitrogen cycling, etc) differ when contained in vesicles compared to the bulk environment.
You will have access and training to pressurised hydrothermal reactors to carry out your experiments at relevant environmental conditions, alongside a suite of analytical instrumentation such as gas chromatography-mass spectrometry, nuclear magnetic resonance, wide field light microscopy, cell cytometry and electron microscopy.
Methodology
You will optimise methods for entrapping nanosized redox active minerals within fatty acid vesicles and use hydrothermal reactors to test how the minerals can facilitate or catalyse chemistry relevant to the early metabolic cycles. You will quantify changes in key inorganic and organic molecules using a wide range of complimentary analytical techniques. Key methods could include ion chromatography, gas and liquid chromatography-mass spectrometry, x-ray photoelectron emission spectrometry, and electron and fluorescent light microscopy. You will compare analytical results to geochemical models.
Project Timeline
Year 1
Review of literature, training in experimental design and apparatus, training in analytical methods and geochemical modelling. Method development to entrap minerals within relevant vesicles and initial experiments under early Earth conditions. Presentation of initial results at a UK workshop/conference.
Year 2
Experiments focused on quantifying how rates and products of key reactions (e.g. carbon fixation, nitrogen transformations) differ between vesicles and the bulk environment. Preparation of first manuscript, presentation of results at a UK or international conference.
Year 3
Final experiments and modelling following up on insights/key research gaps identified from Year 2. Presentation of results at a UK or international conference.
Year 3.5
Timeline – Year 3.5 (6 months only)*
Completion of final thesis/further manuscripts.
Training
& Skills
At the start of your studies an analysis of your training requirements will be undertaken and a tailored programme of training and support developed by yourself and their supervisory team. Project specific training will include experimental design, analytical inorganic and organic geochemistry, and geochemical modelling.
References & further reading
Dongyang S. et al Highly reactive and stable nanoscale zero-valent iron prepared within vesicles and its high-performance removal of water pollutants, Applied Catalysis B: Environmental 2018, 221: 610-617. https://doi.org/10.1016/j.apcatb.2017.09.057.
Hanczyc M.M. et al. Mineral Surface Directed Membrane Assembly, Origins of Life and Evolution of the Biosphere 2007, 37:67–82. DOI 10.1007/s11084-006-9018-5
Preiner M et al. A hydrogen-dependent geochemical analogue of primordial carbon and energy metabolism. Nature Ecology & Evolution 2020, 4(4): 534-542. https://doi.org/10.1038/s41559-020-1125-6
