FIG. 3.

Nutrient downshifts. (A) E. coli MG1655 cells grown to mid-log phase in LB were downshifted by resuspension in MOPS medium without a carbon source or amino acids. (B) E. coli MG1655 cells grown to mid-log phase in LB were downshifted as above and then upshifted by resuspension in LB. Growth in rich medium (LB) or SM (MOPS medium without a carbon source or amino acids) is indicated by dark or light bars, respectively. (C) E. coli MG1655 cells grown to mid-log phase in LB were downshifted to MOPS medium with low phosphate (0.1 mM) and without amino acids. PolyP was assayed as described in Materials and Methods.