Extended Data Fig. 5: Numerical simulations of the sensor-actuator circuit (see Supplementary Discussion 2 for modeling details).
From: Genetically engineered control of phenotypic structure in microbial colonies
a, Activation of the stress sensor upon growth arrest in numerical simulations of a well-mixed batch culture of cells. The promoter strength of the sensor is modeled to increase with the NaCl concentration in the media (cf. Figure 1e). b, Actuator and population dynamics in batch culture upon IPTG induction. The arrow marks the start of induction. The production rate of the actuator protein is proportional to the IPTG induction level, halting growth earlier for higher IPTG (cf. Figure 2a). c, Spatiotemporal simulations of actuator protein induction and population dynamics in a microfluidic trap. 1 h and 5 h pulses of IPTG (amplitudes 0.5) lead to reversible growth resumption in the growth arrested region of the simulated microcolony (cf. Figure 2b and Extended Data Fig. 4). d, Numerical simulations of the full spatiotemporal model of the sensor-actuator circuit coupled with population and nutrient dynamics. Oscillations near the growth interface are observed for sufficiently high induction (NaCl) levels of the sensor promoter. e, In the oscillatory layer of the microcolony (compare d), induction of the actuator protein is followed by growth resumption, which is followed by growth arrest and induction of the actuator protein from the stress sensor, restarting the cycle (cf. Figure 2g).
