Dynamics of AHL mediated quorum sensing under flow and non-flow conditions
Dynamics of AHL mediated quorum sensing under flow and non-flow conditions
复制标题
DOI：
10.1088/1478-3975/9/2/026007
复制
发表时间：
2012-04-01
期刊：
影响因子：
2
通讯作者：
Raedler, Joachim O.
中科院分区：
文献类型：
--
作者：
Meyer, Andrea;Megerle, Judith A.;Raedler, Joachim O.
群体感应（QS）描述了微生物借助小分子相互通讯的能力。在这里，我们研究了含有基于绿色荧光蛋白的 AHL 报告基因的恶臭假单胞菌 IsoF 中酰基高丝氨酸内酯 (AHL) 诱导的 QS 调节基因表达的动态。在向先前在不含 AHL 的培养基中达到 QS 非活性状态的细胞中外部添加规定的 AHL 浓度后，监测各个集落的荧光时间进程。使用微流体设置，实验在流动和非流动条件下进行。我们发现，在不提供外部的情况下，AHL 基因表达在没有流动的情况下被诱导，而流动则抑制诱导。无论没有流动还是有流动，在低 AHL 浓度下，荧光起始均显着延迟，而在添加高浓度 AHL 后，荧光开始直接增加。无流量和流量之间的差异可以使用二室模型来解释。这表明 AHL 在不受流量影响的体积中累积。此外，实验还显示出显着的细胞间和菌落间变异性，这在区室化 QS 机制的背景下进行了讨论。
Quorum sensing (QS) describes the capability of microbes to communicate with each other by the aid of small molecules. Here we investigate the dynamics of QS-regulated gene expression induced by acylhomoserine lactones (AHLs) in Pseudomonas putida IsoF containing a green fluorescent protein-based AHL reporter. The fluorescence time course of individual colonies is monitored following the external addition of a defined AHL concentration to cells which had previously reached the QS-inactive state in AHL-free medium. Using a microfluidic setup the experiment is performed both under flow and non-flow conditions. We find that without supplying external AHL gene expression is induced without flow while flow suppresses the induction. Both without and with flow, at a low AHL concentration the fluorescence onset is significantly delayed while fluorescence starts to increase directly upon the addition of AHL at a high concentration. The differences between no flow and flow can be accounted for using a two-compartment model. This indicates AHL accumulation in a volume which is not affected by the flow. The experiments furthermore show significant cell-to-cell and colony-to-colony variability which is discussed in the context of a compartmentalized QS mechanism.