FIG 1.

Inactivation of the Pta-AckA pathway affects growth characteristics of B. anthracis. (A) Growth curves of the wild-type (wt) strain V770-NP1-R and mutant strains V770-ackA and V770-pta grown aerobically in TSB containing 0.25% glucose. The OD₆₀₀ and the pH of the culture medium were determined at the indicated times. (B) Growth rate of the wild-type strain V770-NP1-R and mutant strains V770-ackA and V770-pta grown aerobically in TSB containing 0.25% glucose, determined between 0 and 3 h of growth. (C) Temporal accumulation and depletion of acetic acid in the culture medium of strains V770-NP1-R, V770-ackA, and V770-pta. (D) Acetate excretion rate determined for strains V770-NP1-R, V770-ackA, and V770-pta between 0 and 3 h of growth. (E) Temporal depletion of glucose from the culture medium of strains V770-NP1-R, V770-ackA, and V770-pta. (F) Glucose consumption rate determined for strains V770-NP1-R, V770-ackA, and V770-pta between 0 and 3 h of growth. For panels A, C, and E, the results are representative of at least three independent experiments. For panels B, D, and F, the results are presented as the means plus standard errors of the means of duplicate determinations for at least three independent experiments. Statistical significance between the wild-type strain and the pta and ackA mutants was determined by using Student's t test. *, P <0.005.