The Great Escape: Biofilm formation and dispersal
Bacteria form biofilms on almost all surfaces, ranging from ship hulls to cooling towers, to indwelling biomedical devices. Biofilms also play positive roles, for example, floc and granule formation for the biological remediation of contaminated water. Therefore, there is strong drive to understand the processes of biofilm formation, to either eliminate biofilm formation in some industrial processes and human health, or to encourage their formation, for processes such as remediation. To develop innovative, environmentally friendly, biofilm control technologies, it is essential to understand the process of biofilm formation and how bacteria control the process of dispersal.
Bacteria rapidly respond to changes in nutrient conditions, and we have shown that depletion of nutrients, e.g. carbon limitation or nitrogen, can lead to dispersal of bacterial biofilms. This process is mediated via an intracellular second messenger cascade, using cAMP and c-di-GMP and may also be linked to other physiological signals such as nitric oxide mediated dispersal.
We have also shown that biofilm development and dispersal is dependent on a prophage carried by Pseudomonas aeruginosa. The phage plays an important role in multiple aspects of biofilm development and stability and we are beginning to unravel the mechanisms result in phage conversion which ultimately are linked to biofilm development.