The Influence Of Sulfur Cycling On Community Diversity In Hypersaline Mars Analogue Environments

Extremophilic microbes thrive in conditions at the limits of life. They are thought to have been the first life on Earth and may have played a key role in its subsequent diversification. Studying extremophilic microorganisms is important in order to: 1) characterise the physical and chemical boundaries of life on Earth; 2) identify the keystone processes that underpin life in these extreme environments; 3) identify metabolites and proteins produced by these extremophiles that have industrial applications; 4) better develop the concept of habitability and an understanding of the potential for life in extraterrestrial environments.
Extremophiles are also believed to be critical to the evolution of the Earth's biogeochemical cycles, including the sulfur cycle, with sulfur metabolisms having evolved early after the origination of life. Sulfur metabolising species continue to play a key role in extreme environments today, for example in saline environments where they are often the most abundant electron donors and acceptors. In turn, microbes with sulfur metabolisms often dominate and drive primary production. This project will focus on developing our understanding of the processes underpinning the survival of these extremophilic microbes as well as characterising interactions that fuel the persistence of microbes in extreme environments at the community level.
This studentship will focus on samples collected from a series of hypersaline lakes in Spain that undergo annual drying-rewetting cycles and are exposed to high levels of ultraviolet radiation. It will involve: 1) understanding the metabolic strategies that enable survival in this environment, using a metagenomic approach; 2) assessing the interactions between distinct functional clades of microbes via metatranscriptomics; 3) further definition of these interactions and dependencies through a series of growth experiments using type strain representatives of these functional clades. The project will use a combination of state-of-the-art molecular techniques and culture-based microbiology.