Microbiology. 2003 Oct;149(Pt 10):2859-71.

A three-dimensional, stochastic simulation of biofilm growth and
transport-related factors that affect structure.

Chang I, Gilbert ES, Eliashberg N, Keasling JD.

Department of Chemical Engineering, University of California, Berkeley, CA
94720-1462, USA.

Biofilm structural heterogeneity affects a broad range of microbially catalysed
processes. Solute transport limitation and autoinhibitor production, two factors
that contribute to heterogeneous biofilm development, were investigated using
BacMIST, a computer simulation model. BacMIST combines a cellular automaton
algorithm for biofilm growth with Brownian diffusion for solute transport. The
simulation represented the growth of microbial unit cells in a three-dimensional
domain modelled after a repeating section of a constant depth film fermenter.
The simulation was implemented to analyse the effects of various levels of
transport limitation on a growing single-species biofilm. In a system with rapid
solute diffusion, cells throughout the biofilm grew at their maximum rate, and
no solute gradient was formed over the biofilm thickness. In increasingly
transport-limited systems, the rapidly growing fraction of the biofilm
population decreased, and was found exclusively at the biofilm-liquid interface.
Trans-biofilm growth substrate gradients also deepened with increasing transport
limitation. Autoinhibitory biofilm growth was simulated for various rates of
microbially produced inhibitor transport. Inhibitor transport rates affected
both the biofilm population dynamics and the resulting biofilm structures. The
formation of networks of void spaces in slow-growing regions of the biofilm and
the development of columns in the fast-growing regions suggested a possible
mechanism for the microscopically observed evolution of channels in biofilms.

Publication Types:
    Research Support, Non-U.S. Gov't 

PMID: 14523118 [PubMed - indexed for MEDLINE]