Quorum-sensing circuit in engineered Escherichia coli Nissle 1917 (null)

The *quorum-sensing circuit in engineered Escherichia coli Nissle 1917* refers to a synthetic or natural regulatory system enabling these bacterial cells to detect specific diffusible chemical signals (autoinducers, such as AI-2), and coordinately alter gene expression in response to changes in population density or the presence of other microbial or host signals. In Nissle 1917, the primary relevant native circuit is the AI-2 quorum-sensing pathway, which uses the LuxS enzyme to produce AI-2 for interspecies communication and regulation of behaviors including colonization and immune modulation. Engineered circuits typically introduce synthetic promoters and response elements, enabling new therapeutic or antimicrobial activities in response to quorum-sensing signals, particularly for programmable probiotic interventions. This is not a canonical molecular target but an engineered regulatory system used in the context of synthetic biology and microbiome therapeutics.

Other names

Quorum-sensing system in Escherichia coli Nissle 1917QS circuit in EcNSynthetic quorum-sensing module (if specifically engineered)null

Regulation of bacterial gene expression by sensing extracellular concentrations of autoinducers (such as AI-2 synthesized via LuxS pathway in Nissle 1917) Activation or repression of downstream synthetic genes, e.g., for therapeutic or antibacterial production in engineered strains Signal integration for population-density dependent behaviors