Microbial interactions and processes modelling (Contact: Brian Merkey / Barth F. Smets)
Mathematical models are useful to develop an understanding of systems that are governed by microbial dynamics. They are used to check the consistency of a set of assumptions with real observations or to predict the behavior and the performance of a complex system. Depending on the system and question, different modelling approaches are used: mass-balance models, spatially structured mass-balance models, or individual-based models.
Mass-balance models are the analytical translation of conservation laws: These models can be analysed using standard differential equation methods, by characterizing the existence and stability of steady-state solutions, and by optimal parameter identification procedures. Spatially-structured mass-balance (continuum) models are based on the same principle but without assuming a homogenous distribution of the conditions: These models, generally based on partial differential equations, are used to assess the dynamics of biofilm growth in different hydrodynamic and substrate-availability conditions. Individual-based models simulate interactions of reactive entities in a 2D or 3D environment. The individual agents may represent individual bacteria or even clumps of bacteria. These models are well-suited to assess problems where cell-cell interactions play an important role or where the behaviour of different cells cannot be summarized by an average behaviour. We are also the host for the cross-institutional Individual-based modelling platform iDynoMicS.
All of these models can be used to assess problems in microbial ecology: Individual-based models are currently used to study the dynamics of gene transfer and the stability of metabolic stratification in biofilms, while spatial mass-balance models are used to explore optimal conditions needed to maintain N-removing stratified biofilms on membrane surfaces.
In each modelling effort, we try to use relevant experimental observations: CSLM and image analysis for individual-based models, micro-sensors for 2D PDE-models, and respirometry for mass-balance models.