FIG 9.

The Pta-AckA system is required for acetate consumption in Vibrio cholerae. (A) Acetate was measured in duplicate cultures of the WT, Δacs, and Δpta-ackA strains at the designated times. The Δpta-ackA strain was incapable of excreting acetate but, upon supplementation with 5.6 mM acetate (NaAc) after the 6-h time point, was able to consume exogenous acetate. (B) In the same assay, acetate concentrations in cultures with the Δpta and ΔackA strains were measured. The Δpta strain was unable to excrete acetate, but the ΔackA strain both excreted and consumed acetate similarly to the WT strain. In both panels A and B, the concentration of acetate in uninoculated LB medium is also depicted, indicating the baseline level. Standard deviations are indicated and are often smaller than the size of the symbol. (C) Strains carrying deletions in the pta-ackA system are not impaired during growth on acetate minimal medium. Averages from at least 3 wells of a 96-well plate are shown; error bars depict standard deviations and are often smaller than the symbol. (D) Survival of Drosophila flies infected with the pta, ackA, or pta-ackA mutant. Survival of flies provided with these mutants does not differ from that of flies fed the WT (P > 0.05 by a log rank test).