Spatio-temporal dynamics of reactive oxygen species in mixed biofilms

Bacterial cells typically live in a spatially structured community known as a biofilm. Understanding of how cells in a mixed biofilm modify micro-environments and generate complex temporal environmental variations is still poor. Of particular interest is to better understand the generation, degradation and diffusion of metabolites associated with the oxygen metabolism. These are short-lived and highly mutagenic metabolites known as reactive oxygen species (ROS). ROS can act as signalling molecules, but typically, they damage proteins and mutate DNA. Therefore, bacteria tightly control ROS with different antioxidant enzymes, such as superoxide dismutases, catalases and peroxidases, and with small molecule antioxidants.

Main goal is to carry out a detailed analysis of ROS generation/degradation rates across a mixed biofilm. We will study cell-to-cell variation in ROS generation/degradation rates and identify molecular factors that drive these rates. Using single cell and single molecule approaches we will also test how antibiotics and antioxidants affect ROS.

This is important for the fundamental understanding of ROS-generated mutations and antimicrobial resistance in mixed biofilms. Identifying conditions that favour low rates of mutations and increased killing by antibiotics can extend the usefulness of existing and effective antibiotics.