FIG 5.

Effect of methylglyoxal on competitive fitness of a Δpcm mutant. (A) Effect of methylglyoxal on survival of stationary-phase cells. Cultures of JV1120 (wild type; ■) and JV1168 (Δpcm; □) were grown to stationary phase, methylglyoxal was added to the indicated concentration, and cultures were incubated 24 h longer before measuring survival by viable counts. (B) JV1120 (wild type) and JV1168 (Δpcm mutant) were grown individually to stationary phase, mixed at 1:10, 1:1, or 10:1 ratios, and allowed to compete for 10 days in the presence of 1.5 mM methylglyoxal. Samples were quantitated by viable counts on the indicated days and the relative competitive index (RCI) calculated as described in the text. Open circles (○) represent the RCI of individual samples; closed squares (■) indicate mean RCI, with error bars representing one standard deviation in each direction.