Explaining Bacterial Dispersion on Leaf Surfaces with an Individual-Based Model (PHYLLOSIM)

Research output: Contribution to journalArticlepeer-review


Colleges, School and Institutes

External organisations

  • University of California, Davis
  • Department of Plant Pathology
  • University of California Davis
  • Laboratory of Environmental Toxicology and Aquatic Ecology, Faculty of Bioscience Engineering, Department of Applied Ecology and Environmental Biology, Ghent University (UGent), Jozef Plateaustraat 22, B-9000 Gent, Belgium. karen.vanhoecke@ugent.be
  • Department of Microbial Ecology
  • Netherlands Institute of Ecology
  • Department of Aquatic Ecology and Water Quality Management
  • Wageningen University and Research Centre


We developed the individual-based model PHYLLOSIM to explain observed variation in the size of bacterial clusters on plant leaf surfaces (the phyllosphere). Specifically, we tested how different 'waterscapes' impacted the diffusion of nutrients from the leaf interior to the surface and the growth of individual bacteria on these nutrients. In the 'null' model or more complex 'patchy' models, the surface was covered with a continuous water film or with water drops of equal or different volumes, respectively. While these models predicted the growth of individual bacterial immigrants into clusters of variable sizes, they were unable to reproduce experimentally derived, previously published patterns of dispersion which were characterized by a much larger variation in cluster sizes and a disproportionate occurrence of clusters consisting of only one or two bacteria. The fit of model predictions to experimental data was about equally poor (<5%) regardless of whether the water films were continuous or patchy. Only by allowing individual bacteria to detach from developing clusters and re-attach elsewhere to start a new cluster, did PHYLLOSIM come much closer to reproducing experimental observations. The goodness of fit including detachment increased to about 70-80% for all waterscapes. Predictions of this 'detachment' model were further supported by the visualization and quantification of bacterial detachment and attachment events at an agarose-water interface. Thus, both model and experiment suggest that detachment of bacterial cells from clusters is an important mechanism underlying bacterial exploration of the phyllosphere.


Original languageEnglish
Article numbere75633
JournalPLoS ONE
Issue number10
Publication statusPublished - 4 Oct 2013