FIG 5.

IPTG-dependent activation of malA-lacZ by a lac promoter-controlled malR in B. thailandensis. Cells were grown with 15 μg/ml trimethoprim (solid symbols) or without trimethoprim (open symbols) and IPTG as indicated. Shown is the growth-adjusted activity of a malA-lacZ chromosomal reporter in the native malR deletion with a lac promoter-controlled malR strain (TT08) (circles) and an isogenic strain with the lac promoter but no malR (TT07) (squares). The values are the means ± ranges from the results of two independent experiments. Statistical analysis was done by t test of the trimethoprim-treated strain compared to the identical strain grown without trimethoprim; *, P ≤ 0.05.