Parent Mary E, Snyder Charles E, Kopp Nathaniel D, Velegol Darrell
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, United States.
Colloids Surf B Biointerfaces. 2008 Apr 1;62(2):180-7. doi: 10.1016/j.colsurfb.2007.09.031. Epub 2007 Oct 2.
Quorum sensing is almost always regarded as a population density effect in three-dimensional bulk samples of bacteria. Here we create two-dimensional samples of Vibrio fischeri cells adhered onto glass surfaces to examine the effect of local population densities on quorum sensing. This is done by measuring the luminescent response. The 2-D bacterial populations enable us to simultaneously account for time and distance effects on quorum sensing, which were previously very challenging to access in typical three-dimensional bulk samples. Thus, we are able to consider quorum sensing in terms of signal diffusion. A diffusion model of quorum sensing signals guides the experiments and shows that for a given cell spacing (density) and diffusion time there exists a "true quorum"- a number of cells necessary for quorum sensing. We find that quorum sensing can occur locally in 2-D surface samples and is a function of cell population density as well as signal diffusion time.
群体感应几乎总是被视为细菌三维大量样本中的一种群体密度效应。在这里，我们创建了附着在玻璃表面的费氏弧菌细胞的二维样本，以研究局部群体密度对群体感应的影响。这是通过测量发光响应来实现的。二维细菌群体使我们能够同时考虑时间和距离对群体感应的影响，而这在典型的三维大量样本中以前是很难实现的。因此，我们能够从信号扩散的角度来考虑群体感应。群体感应信号的扩散模型指导了实验，并表明对于给定的细胞间距（密度）和扩散时间，存在一个“真正的群体感应阈值”——群体感应所需的细胞数量。我们发现群体感应可以在二维表面样本中局部发生，并且是细胞群体密度以及信号扩散时间的函数。
