Growth of E. coli W3110 strains during osmotic (inorganic salts and sugars), heat, and pH stresses. Strains were grown for 24 h in M9-2% glucose medium containing NaCl (A), KCl (B), KH2PO4 (C), arabinose (D), glucose (E), mannose (F), or xylose (G). Strain JP20, a trehalose-overproducing derivative (JP10 lacI-Ptac-otsBA), was grown under the same conditions with (▪) and without (□) 0.1 mM IPTG. Strains W3110, JP10, and JP20 were also compared for tolerance to heat (H) and pH (I). Symbols for all panels: ○, W3110 (wild type); ▵, JP10 (trehalose-negative mutant); □, JP20; ▪, JP20 with IPTG.