Different sugar promoters can be either simultaneously or sequentially expressed in a sugar mixture. a-e) Promoter activity of CRP reporter (black), araB (blue), and a second sugar system promoter (red) in a mixture of sub-saturating arabinose (0.005%) and saturating second sugar (0.2%). The second sugars and promoters are a) lacZ and lactose, b) xylA and xylose, c) srlA and sorbitol, d) rhaB and rhamnose, e) rbsD and ribose. Note that a, b and c show simultaneous expression of the two promoters, whereas d and e show sequential expression. Also shown are optical density OD600
(f-j), and growth rate defined as dlog(OD)/dt panels (k-o) for the corresponding growth conditions. Drop in growth rate at late times is entry to stationary phase. Colors represent the strains as in fig a-e. Promoter activity data is normalized to its maximal value, mean day-day relative errors of growth rate and promoter activity were 8% and 9% respectively.