Fig. 6: Feedforward controller promotes persistent GOI expression in a co-culture with a competitor strain.

a The OL strain consists of P_OL in CF945. This strain expresses RFP using the AHL inducible Plux promoter. b The CL strain consists of P_IFFL_1 in CF945. This strain co-expresses RFP and SpoTH using the AHL inducible Plux promoter. c The competitor strain has P_BFP in TOP10. This strain constitutively expresses BFP. d Temporal responses of growth rate for the OL and CL strains grown in isolation post activation of the RFP gene (GOI) through AHL induction. The growth rate of the competitor strain grown in isolation is shown with a blue line (see Supplementary Fig. 8 for raw data). e, f Temporal responses of RFP (red) and BFP (blue) fluorescence normalized by the total OD of the co-culture (OD_total) for the OL and competitor strains co-culture in e, and for the CL and competitor strains co-culture in f. AHL+ denotes media containing the AHL inducer at 27.5 nM concentration. The growth rate and fluorescence of each strain for all biological replicates was simultaneously tracked in isolation (Supplementary Fig. 8). Data are shown as the mean ± one standard deviation (N = 3, three biological replicates). Individual experimental values are presented as black dots. All experiments were performed in media with glycerol as the sole carbon source. The complete experimental protocol is provided in the Materials and Methods section. Plasmid description, plasmid map, and essential DNA sequences are provided in the Supplementary Information section Plasmid maps and DNA sequences.