Resilience and metabolic adaptation in extremophilic archaea: insights into microbial function under abiotic stress relevant to environmental health and agricul
Supervisors:
Bobby Graham, School of Biological Sciences, Queen’s University Belfast
Nick Robinson, Biomedical and Life Sciences, Lancaster University
Ciaren Graham, Queen’s University Belfast
Summary:
Rapid climate change is accelerating soil salinisation and episodic drought, undermining crop productivity, soil function and food security. At the same time, oxyhalide contaminants (e.g., chlorate/perchlorate) and saline brines affect environmental health and water quality. Extremophilic archaea provide powerful models for understanding how cells maintain proteome integrity, energy balance and redox homeostasis under intense abiotic stress (high salt, chaotropic ions, oxidative stress, desiccation). Mechanisms evolved by halophiles such as ionic homeostasis (K⁺ accumulation), salt-adapted enzymes and chaperones, specialized membranes and carotenoid antioxidant, offer principles for engineering resilient microbiomes, discovering robust biocatalysts, and stabilising bio-based processes in stressed agricultural environments.
This PhD explores the resilience and metabolic adaptation of extremophilic archaea, using Haloferax mediterranei (with H. volcanii as comparator) as a model. We will grow these organisms in carefully defined environmental brines, and deploy state-of-the-art proteomics and mass spectrometry to map the proteins, pathways and post-translational modifications that enable survival. By integrating systems analysis with Haloferax genetics and enzyme biochemistry, we will pinpoint the key mediators that stabilise proteomes, maintain energy balance and control oxidative stress under low-water-activity, high-salt conditions.
Outputs-
- A mechanistic atlas of proteome stability and metabolic plasticity in extreme brines.
- A shortlist of salt-stable enzymes with translational potential for agri-biotech and water applications.
Training in microbial physiology, mass spectrometry-based proteomics, bioinformatics, molecular biology, and biochemistry aligned with UK bioscience and agri-tech needs