This project will involve collaboration with Jannie Hofmeyr (SU) on, amongst others the principles of supply and demand as driving force of metabolic activity, and incorporating them: 1) into existing experimental data sets to explore adaptive behavior amongst bacteria as a basis for the maintenance of microbial community function in environmental processes, and 2) a state-of-science review related to microbiological considerations for repository engineering and long-term safety of deep geological repositories of nuclear waste, as well as formulating recommendations for the way forward to predict the potential impact of microbial activity on the stability of these repositories.