Microbial survival in the energy-limited deep biosphere

The deep subsurface biosphere contains a vast proportion of Earth’s microbial life and organic carbon. In deep, energy-limited settings, microorganisms persist over extraordinarily long timescales with very slow metabolisms – constituting an important analogue to the potential for life beyond Earth. However, the subsurface is notoriously difficult to study because of its remoteness and limited access, as well as the low biomass concentrations and energy fluxes associated with microbial activity. Therefore, numerical models are pivotal in addressing how microorganisms endure, proliferate, and assemble in deep subsurface settings, and understanding the selective environmental pressures that determine energetic trade-offs between growth and maintenance activities. This PhD project provides the opportunity to work at the frontier of deep biosphere science by developing a microbially-explicit model for the subsurface. This model will provide quantitative insight into microbial and geochemical coupling in deep marine or terrestrial settings, and insight into the energetic limit of life. The project would suit a computational and numerate student with an interest in life in extreme environments, biogeochemistry, and microbial-biogeochemical modelling.

Policy Impact of Research
Understanding the impact of microorganisms on the subseafloor stores of organic carbon will be a powerful tool for policy makers and stakeholders. The project will produce methods and software that will be released on an open source and freely available platform that can be applied by anybody. The analysis and understanding of complex interactions and feedbacks between microorganisms and their environment will inform management decisions including conservation strategies, the designation of marine protected area implementations and subseafloor exploration.

Research Relating to this Project
Slow Microbial Life in the Seabed
Survival of the fewest: Microbial dormancy and maintenance in marine sediments through deep time
The biomass and biodiversity of the continental subsurface

How to apply
Opportunities for funding include London NERC DTP and QMUL Principal’s Postgraduate Research Studentships. For further information about the project, eligibility and future application deadlines in 2019/20, please contact Dr James Bradley.