Construction and Characterization of Biological Circuits to Create a Synthetic Bacterial Consortium to Divide Genetic Functions and Reduce the Metabolic Burden

Bacterial quorum sensing (QS) signal synthases, receptors, and cognate promoter elements are important components of a wide variety of engineered biological devices. We employed QS components to construct a bidirectional cell to cell communication network using three compartmentalized circuits to create a synthetic bacterial consortium. This strategy allows us to obtain a better control of gene expression, divide functions of these genes and has the potential to become a powerful biotechnology for various applications. We constructed a synthetic bacterial consortium, in three different Cupriavidus pinatubonensis JMP134 bacterial cell, creating a genetic variant monospecie consortium. luxI gene present in circuits of bacteria A and C and rhlI gene present in circuit of bacterium B, catalyze the synthesis of the acyl homoserine lactone (HSL), 3-oxododecanoyl-HSL and butanoil-HSL, respectively. When HSLs signal accumulate at high enough concentrations these molecules diffuse through the cell membrane and binds to their cognate transcription factor (LuxR in A and C and RhlR in B) and activate respectively promoter. We characterized the promoter activity of each circuit in presence or not of each HSL and in different combinations by flow cytometry. The results suggest that genetic variants strains of C. pinatubonensis, expressing the constructed circuits, seem to have a predictable behavior. The data obtained can be used to model and simulate the consortium dynamics and predict the complex behaviors of bacteria in response to specific environment.

Proyecto FONDECYT postdoctorado Nº 3140031