The deep seafloor covers about 70% of the Earth’s surface and is home to a diversity of life, mainly microorganisms. To survive in this extreme environment where there is no sunlight, often extremely cold and at very high hydrostatic pressures (e.g. >10 MPa at 1000 meter depth), the microbes that live there have special adaptations. In particular, billions of bacteria per millilitre of seafloor thrive under these conditions, and their role in global nutrient cycles is pivotal as they convert a significant fraction of the organic matter that sinks to the bottom of the oceans back into nutrients that is feed into the food chain. Some of the carbon from this organic matter is buried in the deep ocean for almost eternity, which contributes significantly to the removal of carbon dioxide from the atmosphere on geological time scales. These processes are of great importance for marine life and our climate. Despite this, and due to the logistics, costs and other challenges that limit doing studies in the deep seafloor, such as down several kilometres below the sea surface, very little is known about the types of bacteria, how they make a living and how they interact in this extreme environment. This PhD project will investigate this with a focus on a deep-sea region of the Pacific, down to 4 km depth, where there is very little vertical flux of organic matter from the sea surface. With such little organic matter feeding the deep benthos, the project will employ a powerful combination of cutting-edge microbial and molecular biology tools aiming to improve our understanding of the bacteria (and other microbes) that thrive in this environment, and how they do this. Key research objectives are: 1) Determine the taxonomic, genetic and functional diversity of the microbiota, as well as the mechanisms of energy and carbon transfer, and 2) Identify the predominant metabolic pathways in individual taxa and which are shared by communities, and identify the main energy sources driving chemoautotrophic production.

For questions about the project, please contact Dr. Tony Gutierrez: tony.gutierrez@hw.ac.uk

All applicants must have or expect to have a 1st class MSci or equivalent degree by Summer 2023, or at the very least a 1st class Honours degree.  Selection will be based on academic excellence and research potential, and all short-listed applicants will be interviewed (in person or via Teams).

Closing Date: 31st March 2023.  All successful candidates must commence studies by 1st October 2023.

How to Apply

Apply Online

When applying through the Heriot-Watt on-line system please ensure you provide the following information:

(a) In ‘Study Option’, you will need to select ‘Edinburgh’ and ‘Postgraduate Research’.  ‘Programme’ presents you with a drop-down menu. Choose Bio-engineering and Bio-sciences PhD for study option.

(b) In ‘Research Project Information’, you will be provided with a free text box for details of your research project.  Enter Title of the project for which you are applying and also enter the supervisor’s name, who is Dr. Tony Gutierrez.

This information will greatly assist us in tracking your application.

For questions about the application process, please contact pgr.eps@hw.ac.uk

Application deadline:
Start date:
Location: Heriot-Watt University, Edinburgh, Scotland