TY - JOUR
T1 - Effects of carbonylcyanide-m-chlorophenylhydrazone (CCCP) and acetate on Escherichia coli O157:H7 and K-12
T2 - Uncoupling versus anion accumulation
AU - Diez-Gonzalez, Francisco
AU - Russell, James B.
N1 - Funding Information:
This research was supported by the U.S. Dairy Forage Research Center, Madison, WI, USA.
PY - 1997/6/1
Y1 - 1997/6/1
N2 - 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 μmol · (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.
AB - 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 μmol · (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.
KW - Acetate
KW - Escherichia coli O157:H7
KW - Intracellular pH
KW - Potassium
KW - Uncoupling
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U2 - 10.1016/S0378-1097(97)00140-7
DO - 10.1016/S0378-1097(97)00140-7
M3 - Article
C2 - 9198284
AN - SCOPUS:0030787461
SN - 0378-1097
VL - 151
SP - 71
EP - 76
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
IS - 1
ER -