FIG. 2.

Effect of the purine source on the growth rate of B. subtilis purine auxotrophs (purF), which also are defective in purine base uptake (pbuG) and express PbuE at high levels (pbuE1). The wild-type (wt) strain is ED182, the pbuG strain is ED181, the pbuE1 strain is ED464, and the pbuG pbuE strain is ED463. White columns, cells grown with adenine (Ade); light grey columns, cells grown with hypoxanthine (Hyp); dark grey columns, cells grown with adenosine (Ado); black columns, cells grown with inosine (Ino). Purine bases and nucleosides were added at a concentration of 10 μg/ml.