FIG. 2.
Survival of E. coli O157:H7 mutants in pH 3.5 apple cider. Cells were grown overnight in LB MES (pH 5.5) and diluted 1:1,000 into Thrifty Maid apple cider with a measured pH of 3.5. The cultures were incubated at 25°C for the times indicated. Survival was measured by diluting the cultures and plating samples onto LB agar. One-hundred percent survival ranged from 1.5 × 106 to 3 × 106 CFU per ml for all cultures. Strains tested include wild-type (EK274), rpoS (EK275), gadC (EF484), and adiA (EF489).