The dependence of quorum sensing on the depth of a growing biofilm |
| |
Authors: | D L Chopp M J Kirisits B Moran M R Parsek |
| |
Institution: | (1) Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, IL 60208-3125, USA;(2) Department of Civil and Environmental Engineering, Northwestern University, USA;(3) Department of Mechanical Engineering, Northwestern University, USA |
| |
Abstract: | In a process called quorum sensing, bacteria monitor their population density via extracellular signaling molecules and modulate
gene expression accordingly. In this paper, a one-dimensional model of a growing Pseudomonas aeruginosa biofilm is examined. Quorum sensing has been included in the model through equations describing the production, degradation,
and diffusion of the signaling molecules, acyl-homoserine lactones, in the biofilm. From this model, we are able to make some
important observations about quorum sensing. First, in order for quorum sensing to initiate near the substratum, in accordance
with experimental observations, the model suggests that cells in oxygen-deficient regions of the biofilm must still be synthesizing
the signal compound. Second, the induction of quorum sensing is related to a critical biofilm depth; once the biofilm grows
to the critical depth, quorum sensing is induced. Third, the critical biofilm depth varies with the pH of the surrounding
fluid. Of particular interest is the prediction of a critical pH threshold, above which quorum sensing is not possible at
any depth. These results highlight the importance of careful study of the relationship among metabolic activity of the bacterium,
signal synthesis, and the chemistry of the surrounding environment. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|