Figure 3.

Effect of glucose in the medium on sdhC-lacZ expression in the strain TSDH00 and its isogenic mutants. (A) Relative levels of sdhC-lacZ expression. TSDH00 (WT) and its indicated mutant derivatives, each carrying the sdhC-lacZ transcriptional fusion gene on their chromosome, were grown in LB medium or LB medium supplemented with 40 mM glucose under aerobic conditions, and β-galactosidase activities were measured as described under ‘Materials and Methods.’ The shaded and open bars indicate β-galactosidase activities in Miller units in cells grown in LB medium with and without glucose, respectively. Activities represent the average of at least four independent experiments. (B) Glucose repression of sdhC-lacZ expression presented as the ratio of β-galactosidase activities in cells grown in LB to those in cells grown in LB + glucose.