Intracellular pH and survival of Listeria monocytogenes scott a in tryptic soy broth containing acetic, lactic, citric, and hydrochloric acids

Polla S. Ita, Robert W Hutkins

Research output: Contribution to journalArticle

91 Citations (Scopus)

Abstract

To study the effect of citric, acetic, lactic, and hydrochloric acids on Listeria monocytogenes Scott A, growth, survival, and intracellular pH (pHin) values were determined during growth in a pH-controlled fermentation vessel. Under the experimental conditions, L. monocytogenes Scott A grown in tryptic soy (plus yeast extract) broth survived even when the pH was reduced to 3.5. For most acids, L, monocytogenes maintained a pH gradient (intracellular pH-external pH) of about 1.0 pH unit and a pHin near 5.0. When the citric and lactic acid-treated cells at pH values 3.5, 4.0, and 4.5 were incubated for a longer time (24 h), both the pH gradient and the pHin values decreased. Although citric and lactic acids were more effective in lowering the pHin, acetic acid had the greatest effect on cell survival. A greater than 4-log reduction in cell number occurred when L. monocytogenes was held in acetic acid-treated broth for 24 h at pH 3.5 even though the pHin was 5.0. The results suggest that inhibition of L. monocytogenes by acids is caused not by a decrease in the intracellular pH, per se, but rather by specific effects of undissociated acid species on metabolic or other physiological activities.

Original languageEnglish (US)
Pages (from-to)15-19
Number of pages5
JournalJournal of Food Protection
Volume54
Issue number1
DOIs
StatePublished - Jan 1 1991

Fingerprint

Hydrochloric Acid
hydrochloric acid
Listeria monocytogenes
Citric Acid
citric acid
Acetic Acid
lactic acid
Lactic Acid
Proton-Motive Force
Acids
acetic acid
acids
trypticase-soy broth
Growth
Fermentation
yeast extract
Cell Survival
Cell Count
Yeasts
cell viability

ASJC Scopus subject areas

  • Food Science
  • Microbiology

Cite this

@article{67a9b93358844e748b5c0c8d2c52f786,
title = "Intracellular pH and survival of Listeria monocytogenes scott a in tryptic soy broth containing acetic, lactic, citric, and hydrochloric acids",
abstract = "To study the effect of citric, acetic, lactic, and hydrochloric acids on Listeria monocytogenes Scott A, growth, survival, and intracellular pH (pHin) values were determined during growth in a pH-controlled fermentation vessel. Under the experimental conditions, L. monocytogenes Scott A grown in tryptic soy (plus yeast extract) broth survived even when the pH was reduced to 3.5. For most acids, L, monocytogenes maintained a pH gradient (intracellular pH-external pH) of about 1.0 pH unit and a pHin near 5.0. When the citric and lactic acid-treated cells at pH values 3.5, 4.0, and 4.5 were incubated for a longer time (24 h), both the pH gradient and the pHin values decreased. Although citric and lactic acids were more effective in lowering the pHin, acetic acid had the greatest effect on cell survival. A greater than 4-log reduction in cell number occurred when L. monocytogenes was held in acetic acid-treated broth for 24 h at pH 3.5 even though the pHin was 5.0. The results suggest that inhibition of L. monocytogenes by acids is caused not by a decrease in the intracellular pH, per se, but rather by specific effects of undissociated acid species on metabolic or other physiological activities.",
author = "Ita, {Polla S.} and Hutkins, {Robert W}",
year = "1991",
month = "1",
day = "1",
doi = "10.4315/0362-028X-54.1.15",
language = "English (US)",
volume = "54",
pages = "15--19",
journal = "Journal of Food Protection",
issn = "0362-028X",
publisher = "International Association for Food Protection",
number = "1",

}

TY - JOUR

T1 - Intracellular pH and survival of Listeria monocytogenes scott a in tryptic soy broth containing acetic, lactic, citric, and hydrochloric acids

AU - Ita, Polla S.

AU - Hutkins, Robert W

PY - 1991/1/1

Y1 - 1991/1/1

N2 - To study the effect of citric, acetic, lactic, and hydrochloric acids on Listeria monocytogenes Scott A, growth, survival, and intracellular pH (pHin) values were determined during growth in a pH-controlled fermentation vessel. Under the experimental conditions, L. monocytogenes Scott A grown in tryptic soy (plus yeast extract) broth survived even when the pH was reduced to 3.5. For most acids, L, monocytogenes maintained a pH gradient (intracellular pH-external pH) of about 1.0 pH unit and a pHin near 5.0. When the citric and lactic acid-treated cells at pH values 3.5, 4.0, and 4.5 were incubated for a longer time (24 h), both the pH gradient and the pHin values decreased. Although citric and lactic acids were more effective in lowering the pHin, acetic acid had the greatest effect on cell survival. A greater than 4-log reduction in cell number occurred when L. monocytogenes was held in acetic acid-treated broth for 24 h at pH 3.5 even though the pHin was 5.0. The results suggest that inhibition of L. monocytogenes by acids is caused not by a decrease in the intracellular pH, per se, but rather by specific effects of undissociated acid species on metabolic or other physiological activities.

AB - To study the effect of citric, acetic, lactic, and hydrochloric acids on Listeria monocytogenes Scott A, growth, survival, and intracellular pH (pHin) values were determined during growth in a pH-controlled fermentation vessel. Under the experimental conditions, L. monocytogenes Scott A grown in tryptic soy (plus yeast extract) broth survived even when the pH was reduced to 3.5. For most acids, L, monocytogenes maintained a pH gradient (intracellular pH-external pH) of about 1.0 pH unit and a pHin near 5.0. When the citric and lactic acid-treated cells at pH values 3.5, 4.0, and 4.5 were incubated for a longer time (24 h), both the pH gradient and the pHin values decreased. Although citric and lactic acids were more effective in lowering the pHin, acetic acid had the greatest effect on cell survival. A greater than 4-log reduction in cell number occurred when L. monocytogenes was held in acetic acid-treated broth for 24 h at pH 3.5 even though the pHin was 5.0. The results suggest that inhibition of L. monocytogenes by acids is caused not by a decrease in the intracellular pH, per se, but rather by specific effects of undissociated acid species on metabolic or other physiological activities.

UR - http://www.scopus.com/inward/record.url?scp=0002956630&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0002956630&partnerID=8YFLogxK

U2 - 10.4315/0362-028X-54.1.15

DO - 10.4315/0362-028X-54.1.15

M3 - Article

VL - 54

SP - 15

EP - 19

JO - Journal of Food Protection

JF - Journal of Food Protection

SN - 0362-028X

IS - 1

ER -