FIG. 4.

hag-lacZ levels during growth of reporter strain LMB24 in supplemented minimal media. For each panel, the y axis is β-galactosidase activity expressed in Miller units. The x axis is percent CAA in panel A and absorbance at 600 nm in panel B. (A) β-Galactosidase specific activity during growth in S7 minimal medium supplemented with increasing concentrations of CAA; (B) hag-lacZ expression in S7 (open squares), S7 plus 1.6% nutrient broth (closed triangles), S7 plus 0.32% CAA (closed squares), and S7 plus 0.32% amino acids (closed circles). The results of a typical experiment for S7, S7 plus 1.6% nutrient broth, and S7 plus 0.32% CAA are given, and for S7 plus 0.32% amino acids the data presented are the means and standard errors of values from two experiments.