Fig. 1.

(a) Growth of environmental isolates in rich media. ABB02 from beach sand, ECA03 from beach water, and ECA08 from beach water have RpoS-positive catalase and succinate growth phenotypes. ECF09 from untreated combined sewer overflow sewage, ECG09 from beach water, and ECC08 from beach water have RpoS-negative, Suc⁺⁺ phenotypes but are catalase positive. Samplings are indicated as exponential phase (E), early stationary phase (S), and 24 h postinoculation (24). (b) Immunoblot detection of RpoS protein levels in environmental E. coli isolates.