FIG. 10.
CadA activity protects P-starved cells shifted to anaerobiosis. Strains ENZ535 (wt) (○ and •) and ENZ1607 (cadBA) (□ and ▪) were inoculated 1:500 (time zero) into MOPS medium with a limited amount of Pi containing 20 mM glucose. The cultures were incubated with aeration for ∼7 h until the OD600 was ∼0.2 and then supplemented (solid symbols) or not supplemented (open symbols) with 20 mM lysine (+ LYS), and 13-ml fractions were transferred into 15-ml tubes, which were tightly closed and incubated with gentle agitation. Parentheses indicate that no CFU were detected when 20-μl portions of the cultures were directly plated. The data are the means ± standard deviations for two independent cultures representative of several determinations. On day 7 of incubation, the cultures of the wt strain that were not supplemented with lysine (○) contained 5.1 ± 0.1 mM glucose and 9.3 ± 0.4 mM formate (pH 4.39 ± 0.01), whereas the cultures of the wt strain that were supplemented with 20 mM lysine (•) contained 0.01 ± 0.01 mM glucose and 14.5 ± 0.5 mM formate (pH 5.18 ± 0.01).