Effects of carbonylcyanide-m-chlorophenylhydrazone (CCCP) and acetate on Escherichia coli O157:H7 and K-12: uncoupling versus anion accumulation.
Non-growing cells of Escherichia coli O157:H7 and K-12 that were incubated anaerobically in sodium phosphate buffer at pH 6.5 consumed glucose at a rate of approximately 8 mumol.(mg protein)-1.h-1 and had intracellular pH values of 7.3 and 7.5, respectively. The uncoupler, carbonylcyanide-m-chlorophenylhydrazone (CCCP), caused a marked decrease in intracellular pH, ATP and potassium of both strains. Low concentrations of CCCP stimulated glucose consumption rate, but higher concentrations were inhibitory. Acetate also caused a decrease in intracellular pH, but it never caused a large decrease in glucose consumption rate. Acetate decreased the intracellular ATP of E. coli K-12, but it had no effect on the ATP of O157:H7. Acetate had no effect on the intracellular potassium of E. coli O157:H7, and acetate-treated K-12 cells had even more potassium than untreated controls. Based on these results, acetate and CCCP appear to have different effects on E. coli. The comparison of E. coli O157:H7 and K-12 indicated that intracellular pH, acetate accumulation and intracellular potassium were related. E. coli K-12 maintained a higher intracellular pH than O157:H7, accumulated more acetate and had a greater intracellular potassium.
Diez-Gonzalez
F
F
Section of Microbiology, Cornell University, Ithaca, NY 14853, USA.
Russell
J B
JB
D000085:Acetates / Q000494:pharmacology*; D000255:Adenosine Triphosphate / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001692:Biological Transport; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D019453:Escherichia coli O157 / Q000187:drug effects* / Q000378:metabolism*; D005947:Glucose / Q000032:analysis; D011188:Potassium / Q000032:analysis; D014475:Uncoupling Agents / Q000494:pharmacology*
D000085:Acetates; D000900:Anti-Bacterial Agents; D014475:Uncoupling Agents; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D000255:Adenosine Triphosphate; D005947:Glucose; D011188:Potassium