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

University of East Anglia - School of Environmental Sciences

Primary Supervisor: Prof Thomas Mock

Scientific background

Microbial rhodopsins (RHOs) are common in eukaryotic plankton including diatoms, which contribute ca. 45% of annual oceanic primary production. They represent an alternative energy system (proton pumping RHOs – ppRHOs) to support growth under unfavourable conditions (e.g., iron limitation). Hence, since ppRHOs play a key role in enhancing oceanic primary production in the face of limited nutrients, they can be considered as a ‘climate-change coping mechanism’, because nutrient limitations are expected to become more prevalent in the future. The aim of this project is to determine how ppRHOs underpin this ecosystem service. Thus, the PhD candidate will physiologically characterise ppRHO knock-in diatom cell lines and investigate how those results align with the abundance and expression of diatom ppRHO genes in the surface oceans.

Research methodology

Objective 1: Identify the subcellular localisation of two different ppRHOs isolated from the polar diatom Fragilariopsis cylindrus. This work will be done at UEA and IOCAS. To label the two ppRHO variants for TEM, synthetic peptides matching the C-termini have already been synthesized. A diatom-specific TEM protocol will be used to reveal their subcellular localisation. This work will be done at UEA and IOCAS (Prof. Shan Gao).

Objective 2: Using the genetically tractable model diatom Phaeodactylum tricornutum, which does not naturally encode a ppRHO, to generate knock-in cell lines for both ppRHO variants from F. cylindrus and subject them to warming, iron limitation, and acidification. Phenotyping (e.g., photosynthesis measurements, growth rates) will reveal how RHOs contribute to the resilience of diatoms. This work will be done at UEA.

Objective 3: Homologs of both F. cylindrus ppRHO variants will be retrieved from MOSAiC and TARA Oceans omics sequence datasets and their normalised abundance and expression will be analysed in the context of environmental (e.g., concentrations of essential nutrients, temperature, CO2) conditions from pole-to-pole. This work will be done at UEA.

Training

The PhD candidate will acquire skills from the bench (e.g., PCR, cloning, phenotyping) to bioinformatics (e.g., Phython) to integrate data.

Person specification

We are looking for an enthusiastic individual who is excited about applying diverse techniques (e.g., Molecular Microbiology, Bioinformatics).

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).

Acceptable first degree: Biological Science or equivalent.

Start date:1st October 2026

Funding

ARIES studentships are subject to UKRI terms and conditions. Successful candidates who meet UKRI’s eligibility criteria will be awarded a fully-funded studentship, which covers fees, maintenance stipend (£20,780 p.a. for 2025/26) and a research training and support grant (RTSG). A limited number of studentships are available for international applicants, with the difference between 'home' and 'international' fees being waived by the registering university. Please note, however, that ARIES funding does not cover additional costs associated with relocation to, and living in, the UK, such as visa costs or the health surcharge.