Speaker
Description
Synthetic Biology aims at the design and implementation of novel, and more reliable, genetic circuits by employing engineering principles, with applications ranging from health treatments to bioremediation and production of drugs or biofuels. The use of biomolecular PID controllers is particularly appealing in this field as it allows achieving perfect robust adaptation via the integral action as well as to exploit the proportional and derivative actions to modulate the steady-state and transient dynamics of the controlled process . However, embedding all the required circuits to implement a PID controller in a single cell could cause excessive metabolic burden and be cumbersome to implement in vivo; also requiring a complete redesign if the target process to be regulated changes or the parameters of the control action need to be varied. To overcome these problems we present a multicellular implementation of the classical PID feedback controller to regulate gene expression in a microbial consortium. Specifically, we propose to distribute the proportional, derivative and integral control actions between different cellular populations in a microbial consortium comprising a target population whose output needs to be regulated. By engineering communication among the different cellular populations via appropriate orthogonal quorum sensing molecules, we are able to close the feedback loop across the consortium. We derive analytical conditions on the biological parameters and the control gains that can be used to tune the static and dynamical properties of the closed-loop system, guaranteeing the regulation of the output of the target population. Finally, we evaluate the performance and robustness of the proposed multicellular control strategy via extensive in silico experiments in BSim, a realistic agent-based simulator of bacterial populations.
| Department | Electrical Engineering and Information Technology |
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