Fig. 1.

Construction and characterization of the SLC. (a) The circuit contains an activator¹³ and lysis plasmid. When the population reaches the quorum threshold at a critical AHL concentration, the luxI promoter drives the transcription of gene E for lysis, LuxI, and sfGFP or luxCDABE as the reporter module. The luxI or the ptac promoter also drives the transcription of the therapeutic gene for the stabilized circuit used in vivo. LuxR in this system is driven by the native pLuxR promoter. (b) A schematic that illustrates the main stages of each lysis cycle from seeding to quorum ‘firing’. Shown below are typical time series images of the circuit-harboring cells undergoing the three main stages of quorum firing in a microfluidic growth chamber¹². (c) Fluorescence profile of a typical microfludic experiment. The estimated cell population trajectory reveals that lysis events correspond to peaks of sfGFP fluorescence. (d) Period as a function of estimated flow velocity in the media channel of the microfluidic device and environmental temperature. Error bars indicate ±1 standard deviation for 13 - 50 peaks. The above experiments were performed with Strain 1, see Supplementary Information for complete strain information.