FIG 4.

Overexpression of the ptb gene restores growth of the pta mutant in S. aureus. (A) Growth curves of the wild-type (wt) strain UAMS-1, the mutant strain UAMS-1-pta, and UAMS-1-pta with the plasmid pMRS183, containing the ptb gene from B. anthracis, grown aerobically in TSB containing 0.25% glucose. The OD₆₀₀ and the pH of the culture medium were determined at the indicated times. (B) Temporal depletion of glucose from the culture medium of strains UAMS-1, UAMS-1-pta, and UAMS-1-pta with the plasmid pMRS183. (C) Temporal accumulation and depletion of acetic acid in the culture medium of strains UAMS-1, UAMS-1-pta, and UAMS-1-pta with the plasmid pMRS183. In the experiments, the wild-type strain and the pta mutant contain pCN51 (empty vector) plasmid. The results are representative of at least three independent experiments.