Culture-averaged secretion of Tyr and Trp in mono-culture growth experiments.
Over the course of growth, W3 secretes more Tyr per cell with the addition of arabinose and Y3 secretes more Trp per cell with the addition of NaProp. Supernatants were harvested at the early, middle stages, and the end of the exponential growth phase. Note the different units of Trp and Tyr (i.e. μg/L*OD vs. mg/L*OD), which reflect the vast difference between the metabolite secretion capacities of the two strains.