Variable Cell Morphology Approach for Individual-Based Modeling of Microbial Communities

Authored by Tomas Storck, Cristian Picioreanu, Bernardino Virdis, Damien J Batstone

Date Published: 2014

DOI: 10.1016/j.bpj.2014.03.015

Sponsors: Netherlands Organization for Scientific Research (NWO) Australian Research Council (ARC)

Platforms: Java

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

An individual-based, mass-spring modeling framework has been developed to investigate the effect of cell properties on the structure of biofilms and microbial aggregates through Lagrangian modeling. Key features that distinguish this model are variable cell morphology described by a collection of particles connected by springs and a mechanical representation of deformable intracellular, intercellular, and cell-substratum links. A first case study describes the colony formation of a rodshaped species on a planar substratum. This case shows the importance of mechanical interactions in a community of growing and dividing rod-shaped cells (i.e., bacilli). Cell-substratum links promote formation of mounds as opposed to single-layer biofilms, whereas filial links affect the roundness of the biofilm. A second case study describes the formation of flocs and development of external filaments in a mixed-culture activated sludge community. It is shown by modeling that distinct cell-cell links, microbial morphology, and growth kinetics can lead to excessive filamentous proliferation and interfloc bridging, possible causes for detrimental sludge bulking. This methodology has been extended to more advanced microbial morphologies such as filament branching and proves to be a very powerful tool in determining how fundamental controlling mechanisms determine diverse microbial colony architectures.

Tags

Simulation diffusion systems growth Escherichia-coli Transport Multispecies biofilm model Bulking Sludge Detachment