Fig. 5
Comparison of four different sRNA-based (inner-membrane) stress circuit designs on growth and protein production, in relation to the original SohB(TMD)-sfGFP expressing Escherichia coli cells as a reference. a Total sfGFP results for overexpression of membrane targeted sfGFP (inducer concentrations of 0.1 and 0.2 mM IPTG). The fluorescence of SohB(TMD)-sfGFP producing Escherichia coli (E. coli) MG1656 DE3 cells (Additional file 1: Table S2) without stress circuit was arbitrarily set to one and fluorescence of the same strains with respectively D1-4 was compared to this value (Timepoint: 10 h, early stationary phase). b Bar plots representing the output sfGFP/OD600 for overexpression of membrane targeted sfGFP (inducer concentrations of 0.1 and 0.2 mM IPTG). sfGFP/OD600 values for an equal number (OD600 = 0.2) of E. coli MG1656 DE3 cells were plotted. c Specific growth rate (µmax) for strains (E. coli MG1656 DE3) expressing Ref and D1-4, respectively (inducer concentrations of 0.1 and 0.2 mM IPTG). Error bars represent standard deviations based on 3 biological replications. For statistical comparison, a one-way ANOVA was performed. * = p-value < 0.05, *** = p-value < 0.001, IPTG isopropyl β-D-1-thiogalactopyranoside, TMD transmembrane domain, UTR untranslated region, SohB inner-membrane protein from E. coli, sfGFP superfolder green fluorescent protein