FIG. 8.

Effects of ArcA, FNR, cAMP, and CRP on dctA-lacZ expression. Cultures were grown anaerobically (A) or aerobically (B to D) at 37°C in L broth plus 0.4% glycerol and 50 mM fumarate (A), in L broth only (B and D), or in L broth with and without 1% glucose (Glu) and 5 mM cAMP (C). The strains were JRG3351 (wild type [wt]), JRG4011 (arcA), JRG4013 (fnr), and JRG4016 (crp) and the corresponding transformants containing plasmids pRB38 (arcA⁺), pCH21 (fnr⁺), and pGS279 (crp⁺). Note that JRG4017 (the corresponding crp⁺ control for JRG4016) gave very similar results to those obtained with JRG3351 (data not shown). Other details are as for Fig. 7.