A three-dimensional, stochastic simulation of biofilm growth and transport-related factors that affect structure
A three-dimensional, stochastic simulation of biofilm growth and transport-related factors that affect structure
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DOI：
10.1099/mic.0.26211-0
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发表时间：
2003-10-01
期刊：
影响因子：
2.8
通讯作者：
Keasling, JD
中科院分区：
文献类型：
--
作者：
Chang, I;Gilbert, ES;Keasling, JD
生物膜结构的异质性影响了广泛的微生物催化过程。溶质运输限制和自动抑制剂的生产，两个因素，有助于异质性生物膜的发展，使用BacMIST，计算机模拟模型进行了研究。BacMIST将用于生物膜生长的元胞自动机算法与用于溶质运输的布朗扩散相结合。该模拟表示在恒定深度膜发酵罐的重复部分之后建模的三维域中微生物单位细胞的生长。模拟实施，以分析不同水平的运输限制对一个不断增长的单一物种生物膜的影响。在具有快速溶质扩散的系统中，整个生物膜中的细胞以其最大速率生长，并且在生物膜厚度上没有形成溶质梯度。在越来越多的运输限制系统中，生物膜人口的快速增长的部分下降，并发现专门在生物膜-液体界面。跨生物膜生长基质梯度也加深增加运输限制。自动抑制生物膜生长模拟微生物产生的抑制剂运输的各种速率。抑制剂的运输速率影响生物膜的人口动态和由此产生的生物膜结构。在缓慢生长的区域的生物膜和快速生长的区域中的列的发展的空隙空间的网络的形成提出了一个可能的机制，显微镜下观察到的生物膜中的通道的演变。
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.