New individual-based model links microbial growth to the energy available in the environment

Abstract

A new individual-based model is presented in which we aim to describe microbial growth constrained by the environmental conditions at each point of a 2D space. The model is characterized for a full description of the physico-chemistry of the system and uses thermodynamics to approximate the microbial growth. The growth parameters are estimated using the information of the surroundings and it employs only first principles instead of relying on measurements at the population level. This allows ab initio approximation of the growth parameters, and therefore directly links microbial growth and environmental conditions. For this reason, the model is characterised for its flexibility. We test the model in three very different scenarios: anaerobic digestion, aerobic heterotrophic growth and nitrification. Due to its flexibility, rigorous thermodynamic calculations and the possibility to estimate the parameters ab initio, the model will be further used to hypothesize the presence of new functional groups or microbial species not yet discovered and to model complex microbial populations not well understood. Moreover, it can be used to study the rules that control microbial evolution or/and immigration.