A mechanistic Individual-based Model of microbial communities

Jayathilake, Pahala Gedara and Gupta, Prashant and Li, Bowen and Madsen, Curtis and Oyebamiji, Oluwole and González-Cabaleiro, Rebeca and Rushton, Steve and Bridgens, Ben and Swailes, David and Allen, Ben and McGough, A. Stephen and Zuliani, Paolo and Ofiteru, Irina Dana and Wilkinson, Darren and Chen, Jinju and Curtis, Tom (2017) A mechanistic Individual-based Model of microbial communities. PLoS ONE. ISSN 1932-6203

Abstract

Accurate predictive modelling of the growth of microbial communities requires the credible representation of the interactions of biological, chemical and mechanical processes. How-ever, although biological and chemical processes are represented in a number of Individual-based Models (IbMs) the interaction of growth and mechanics is limited. Conversely, there are mechanically sophisticated IbMs with only elementary biology and chemistry. This study focuses on addressing these limitations by developing a flexible IbM that can robustly com-bine the biological, chemical and physical processes that dictate the emergent properties of a wide range of bacterial communities. This IbM is developed by creating a microbiological adaptation of the open source Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). This innovation should provide the basis for " bottom up " prediction of the emer-gent behaviour of entire microbial systems. In the model presented here, bacterial growth, division, decay, mechanical contact among bacterial cells, and adhesion between the bacte-ria and extracellular polymeric substances are incorporated. In addition, fluid-bacteria inter-action is implemented to simulate biofilm deformation and erosion. The model predicts that the surface morphology of biofilms becomes smoother with increased nutrient concentra-tion, which agrees well with previous literature. In addition, the results show that increased shear rate results in smoother and more compact biofilms. The model can also predict shear rate dependent biofilm deformation, erosion, streamer formation and breakup.