TABLE 5.

Inducer-independent expression of P_araB-phoB⁺ and P_araB-phoR⁺ fusions

Strain	Relevant genotypea	BAP sp act onb:
		d-Glucose	d-Fructose	Glycerol
BW24803	ParaB-phoB+ ΔphoB phoR+	0.3 ± 0.0	0.4 ± 0.0	0.4 ± 0.0
BW22861	ParaB-phoR+phoB+ ΔphoR	26.4 ± 4.9	47.7 ± 5.1	58.8 ± 4.4

^aStrains are ΔcreABCD Δ(ackA pta) ΔaraBAD; complete genotypes are given in Table 1. The P_araB-phoB⁺ fusion is in single copy at att_λ; the P_araB-phoR⁺ fusion is in single copy at the araCBAD locus. 

^bCells were assayed after 18 h of growth in 0.06% glucose–, 0.06% fructose–, or 0.1% glycerol–MOPS medium containing 0.1 mM P_i without arabinose. Values are nanomoles of p-nitrophenol made per unit of cell culture optical density at 420 nm (means ± standard deviations). Strains were grown and assayed in triplicate.