In Vivo Multicellular Feedback Control in Synthetic Microbial Consortia

: In this paper, we present a biomolecular control architecture able to guarantee stable and precise regulation of gene expression. Specifically, we engineer a microbial consortium comprising a cellular population, named controllers, that is tasked to regulate the expression of a gene in a second population, termed targets. Traditional biomolecular control strategies, while effective, are predominantly confined to single-cell applications, limiting their complexity and adaptability due to factors such as competition for limited cell resources and incompatible chemical reactions. Our approach overcomes these limitations by employing a distributed multicellular feedback loop between two strains of Escherichia coli, allowing for division of labor across the consortium. In vivo experiments demonstrate that this control system maintains precise and robust gene expression in the target population, even amid variations in consortium composition. Our study fills a critical gap in synthetic biology and paves the way for more complex and reliable applications in the field.