FIG. 7.

Viability of starved cells shifted to anaerobiosis. Strains ENZ535 (wt) (○) and ENZ1565 (pflB) (▵) were inoculated 1:500 (time zero) into MOPS medium with a limited amount of glucose (A), ammonium (B), or P_i (C). The media with limited amounts of ammonium and P_i contained 20 mM glucose. The cultures were incubated with aeration for 7 h until the OD₆₀₀ was ∼0.2, and then 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 for glucose and ammonium starvation are from one culture, and the data for P_i starvation are the means ± standard deviations for two independent cultures representative of several determinations.