Dynamic modelling of cell death during biofilm development
Dynamic modelling of cell death during biofilm development
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DOI：
10.1016/j.jtbi.2011.10.007
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发表时间：
2012-02-21
影响因子：
2
通讯作者：
Rice, Scott A.
中科院分区：
文献类型：
--
作者：
Fagerlind, Magnus G.;Webb, Jeremy S.;Rice, Scott A.
生物膜目前被认为是主要的细菌生活方式，并且有人认为生物膜的发育受到许多不同过程的影响，例如粘附、脱离、传质、群体感应、细胞死亡和主动扩散。细胞死亡是人们最不了解的过程及其对生物膜形成的影响之一。然而，实验研究表明，细菌死亡是生物膜形成过程中的一个重要过程，许多研究表明细胞死亡与微生物生物膜中的扩散之间存在关系。我们提出了生物膜发育过程中细胞死亡过程的模型，特别关注细胞死亡或细胞损伤的空间定位。评估了控制细胞死亡或细胞损伤的三个规则，比较了生物膜形成过程中饥饿、损伤积累和活力的影响，并用于设计基于实验室的实验来测试模型。模型模拟的结果表明，活跃生长的生物膜在生物膜内部形成陡峭的营养梯度，影响邻近的微菌落，导致细胞死亡和脱离。其中两条规则表明，高底物浓度会导致加速细胞死亡，而第三条规则则基于损伤的累积，预测低底物浓度下生长的生物膜会更早发生细胞死亡。模型结果与实验结果的比较表明，低营养条件下有利于细胞死亡，损伤的积累可能是生物膜发育过程中细胞死亡的主要原因。 (C) 2011 Elsevier Ltd. 保留所有权利。
Biofilms are currently recognised as the predominant bacterial life-style and it has been suggested that biofilm development is influenced by a number of different processes such as adhesion, detachment, mass transport, quorum sensing, cell death and active dispersal. One of the least understood processes and its effects on biofilm development is cell death. However, experimental studies suggest that bacterial death is an important process during biofilm development and many studies show a relationship between cell death and dispersal in microbial biofilms. We present a model of the process of cell death during biofilm development, with a particular focus on the spatial localisation of cell death or cell damage. Three rules governing cell death or cell damage were evaluated which compared the effects of starvation, damage accumulation, and viability during biofilm development and were also used to design laboratory based experiments to test the model. Results from model simulations show that actively growing biofilms develop steep nutrient gradients within the interior of the biofilm that affect neighbouring microcolonies resulting in cell death and detachment. Two of the rules indicated that high substrate concentrations lead to accelerated cell death, in contrast to the third rule, based on the accumulation of damage, which predicted earlier cell death for biofilms grown with low substrate concentrations. Comparison of the modelling results with experimental results suggests that cell death is favoured under low nutrient conditions and that the accumulation of damage may be the main cause of cell death during biofilm development. (C) 2011 Elsevier Ltd. All rights reserved.