Effect of growth parameters on circuit behavior. Effect of medium composition on GFP expression in no-feedback (black) and weak feedback cells (promoter m4_5 and weak RBS, grey). GFP levels (Fluorescence per OD600) are shown. (A) M9 0.4% glucose (B) M9 0.4% glycerol and (C) LB medium. Values represent averages +/- standard error of the mean.