Optimal Tuning of Bacterial Quorum Sensing Potential
Anand Pai, Biomedical Engineering, Duke University, Pratt School of Engineering, Science Drive, Durham, NC 27708 and Lingchong You, Biomedical Engineering, Institute for Genome Sciences and Policy, Duke University, Pratt School of Engineering, Science Drive, Durham, NC 27708.
Through production and sensing of small signaling molecules, quorum sensing (QS) enables bacteria to detect changes in their density and act accordingly. A salient characteristic of QS systems is their tremendous diversity in terms of specific sensory components used in each system and their target phenotypes. Cutting across this diversity, however, the central architecture of QS is universal, which includes signal synthesis, secretion, degradation and detection. Exploiting this universality, we define a metric “sensing potential” that quantifies the ability of a single bacterium to measure the dimensions of its microenvironment. Importantly, the sensing potential provides a critical linkage between single-cell properties of a QS module and the resulting population-level outcome. In particular, tuning of the key parameters associated with QS converges in tuning of the sensing potential, which then uniquely determines whether QS is advantageous to the host bacterium. Our work provides a simple, quantitative framework to analyze the dynamics and evolution of quorum sensing.