PhD Studentship - The Role of Light-driven Proton Pumps in Sustaining Oceanic Primary Production

This PhD project at the University of East Anglia investigates the role of microbial rhodopsins (RHOs), specifically proton pumping rhodopsins (ppRHOs), in diatoms—key contributors to global oceanic primary production. Diatoms are responsible for approximately 45% of annual oceanic primary production, and ppRHOs provide an alternative energy system that supports growth under challenging conditions such as iron limitation. As nutrient limitations are expected to increase due to climate change, understanding how ppRHOs enhance diatom resilience is crucial for predicting future ocean productivity. The research aims to physiologically characterize ppRHO knock-in diatom cell lines and correlate these findings with the abundance and expression of diatom ppRHO genes in surface oceans. The methodology includes three main objectives: (1) identifying the subcellular localization of two ppRHOs from the polar diatom Fragilariopsis cylindrus using transmission electron microscopy (TEM) at UEA and IOCAS; (2) generating knock-in cell lines in the model diatom Phaeodactylum tricornutum and subjecting them to environmental stressors such as warming, iron limitation, and acidification to assess phenotypic responses; and (3) analyzing homologs of ppRHO variants from global omics datasets (MOSAiC and TARA Oceans) to study their abundance and expression in relation to environmental variables. The successful candidate will receive comprehensive training in molecular biology techniques (PCR, cloning, phenotyping) and bioinformatics (Python), preparing them for interdisciplinary research. Applicants should have a strong background in biological sciences, meet the English language requirements (IELTS 6.5 overall, 6 in each category), and hold at least a UK equivalent Bachelors (Honours) 2:1 degree. The position is fully funded through the ARIES DTP, covering tuition, a maintenance stipend (£20,780 p.a. for 2025/26), and a research training grant, with fee waivers available for international students. The project is supervised by Professor Thomas Mock, an expert in marine microbiology and diatom research. The start date is October 1, 2026.