Abstract
Summary Quantitative descriptions of biofilm growth and dynamics at the individual cell level are largely missing from the literature. To fill this gap, research was done to describe growth, accumulation and displacement patterns in developing Pseudomonas aeruginosa biofilms. A parent strain of PAO1 was labelled with either a cyan or yellow fluorescent protein. These were then grown in a flow cell biofilm together so that pockets of dividing cells could be identified and their accumulation and displacement tracked. This analysis revealed a pattern of exponential accumulation for all clusters followed by a stationary accumulation phase. A background ‘carpet’ layer of cells uniformly colonizing the surface exhibited zero net accumulation of bio‐volume. The individual clusters were found to have a mean accumulation rate of 0.34 h −1 with a range of 0.28–0.41 h −1 . Cluster accumulation rates were negatively correlated with cluster size; larger clusters accumulated volume at a slower rate ( P