FIG. 3.

Pigment production during the stationary phase is dependent on the relA gene product. Bacteria were grown to an OD₆₀₀ of 3 (14 to16 h of growth, starting from an OD₆₀₀ of 0.1), and after this (zero time) pigment production (A) and bacterial density (B) were measured at intervals of 2 h. Pigment production was measured by determining the OD₅₅₀ after centrifugation, and bacterial density was measured by determining the OD₆₀₀. Symbols: ◊, wild-type strain JR32 containing the vector pMMB207αb; ▪, RelA mutant strain GS-RelA containing the vector pMMB207αb; ▴, GS-RelA complemented with plasmid pGS-RelA-05. The experiment was done three times, and similar results were obtained in all of the experiments. The largest standard deviation for the pigment production measurements was ±0.015.