Fig. 4
From: Direct conversion of theophylline to 3-methylxanthine by metabolically engineered E. coli

Effect of cell and substrate concentrations on 3MX production by E. coli pDdA. Resting cell assays were performed using 5 (open triangle), 10 (open square), 15 (open triangle), 30 (open diamond), and 60 (open circle) mg/mL wet cells. TP concentrations were 1Â mM (a), 2Â mM (b), and 4Â mM (c). Concentrations of TP (left), 3MX (middle), and 1MX (right) are shown as means with standard deviations of triplicate reactions