FIG. 7.

Effect of pH on the ability of acetate to increase transcription of cidABC and lrgAB in S. aureus UAMS-1. Total cellular RNA was isolated from UAMS-1 cells grown to the mid-exponential growth phase (4 h postinoculum) in NZY at increasing pH values (from 4.5 to 7.5, as indicated above each lane of the blot), containing either 30 mM sodium acetate or 30 mM sodium chloride as indicated. Five micrograms of each sample was separated through a 1% (wt/vol) agarose-formaldehyde gel, transferred to a nylon membrane, and hybridized to cidA- and lrgA-specific DIG-labeled probes. The sizes of each transcript were determined by comparison to an RNA ladder (Invitrogen) run on the same gel.