Figure 8. Viability of E. coli triple amidase mutant is dependent on the Cpx and Rcs stress responses.

Cultures of AAY14 [ΔamiA ΔamiB ΔamiC (P_BAD::^ssdsbA-amiA)], and its derivatives lacking cpxR, rcsB, or both of these genes were grown overnight in LB supplemented with 0.2% arabinose, washed with 1x M9 salts, diluted 1:10 in M9 minimal medium supplemented with 0.2% maltose and 0.002% arabinose, and allowed to grow for 2h at 30°C. Cells were then normalized to OD₆₀₀ of 0.5 and serial dilutions were prepared, 5µL aliquots of which were spotted onto M9 plates supplemented either with 0.2% glucose or 0.2% arabinose. Plates were incubated at 30°C for 2d and then photographed.