What does life need to exist? We all need to be able to make energy to grow and reproduce. Humans make energy by breathing air and eating food, but this is not the case for all of life on Earth, nor would it necessarily be possible on other planets. How do organisms survive in extreme Earth environments? For example, microorganisms live where there is no oxygen or air, they also live in ice, boiling springs, salt, acidic waters, and even in rocks buried thousands of metres below the Earth’s surface. Understanding the diversity and limits of life on Earth helps us to define our search for signs of life on other planets including possible chemical and geological signatures.
We work in the Geomicrobiology research group at the University of Manchester. We investigate how the activity of microorganisms influences geological and geochemical processes in the natural environment. For example, we study how bacteria contribute to the release of toxic arsenic from sediments into drinking water supplies in Southeast Asia, and how we can stimulate beneficial microbial activity to help obtain valuable metals from rocks. We examine the composition of microbial communities and how they function in extreme environments, such as those affected by radioactive waste or metal contamination. This understanding will help develop innovative approaches to clean up land and water contaminated by metals, radioactive waste or toxic organics.