Expression of the acs reporter in different chemostat environments at D = 0.15 h-1. Fluorescence measurements report the expression of Pacs-gfp in chemostat environments supplied with minimal media supplemented with only D-glucose, only sodium acetate or D-glucose plus sodium acetate. Background fluorescence is the fluorescence of the promoterless strain depicted in black. The error bars on the plots for mean log expression of Pacs-gfp are standard errors of the mean. The expression of the acs reporter was down-regulated to the greatest extent in chemostats with high concentration of glucose (11.2 mM Glc in the feed).