Diffusion-Limited Growth of Microbial Colonies

Authored by Benjamin J Binder, Hayden Tronnolone, Alexander Tam, Zoltan Szenczi, J E F Green, Sanjeeva Balasuriya, Ee Lin Tek, Jennifer M Gardner, Joanna F Sundstrom, Vladimir Jiranek, Stephen G Oliver

Date Published: 2018

DOI: 10.1038/s41598-018-23649-z

Sponsors: Australian Research Council (ARC)

Platforms: No platforms listed

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

The emergence of diffusion-limited growth (DLG) within a microbial colony on a solid substrate is studied using a combination of mathematical modelling and experiments. Using an agent-based model of the interaction between microbial cells and a diffusing nutrient, it is shown that growth directed towards a nutrient source may be used as an indicator that DLG is influencing the colony morphology. A continuous reaction-diffusion model for microbial growth is employed to identify the parameter regime in which DLG is expected to arise. Comparisons between the model and experimental data are used to argue that the bacterium Bacillus subtilis can undergo DLG, while the yeast Saccharomyces cerevisiae cannot, and thus the non-uniform growth exhibited by this yeast must be caused by the pseudohyphal growth mode rather than limited nutrient availability. Experiments testing directly for DLG features in yeast colonies are used to confirm this hypothesis.

Tags

Simulations Yeast Spatiotemporal patterns Bacterial Colonies Fractal Growth Bacillus-subtilis Agar plates Filamentous growth Branching growth Fungi