Effect of salt concentrations on the growth of heat-stressed and unstressed escherichia coli

S.M. Abdulkarim, A.B. Fatimah, J.G. Anderson

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The effect sodium chloride (NaCl) and potassium chloride (KCl) concentration on the growth of Escherichia coli cells cultivated at 37 and 44°C was studied in an effort to understand the importance of the salts and glucose in medium to the growth of E. coli. A turbidimetric method was used to measure the growth of E. coli after a 24 hours incubation period. The turbidimetric method used gave a high correlation (R2 = 0.9606) with the traditional surface colony count method. Four sets of salt concentrations, 0, 0.5, 1.0 and 1.5% (w/v), were employed throughout this study. Absence of NaCl in the medium was found to slightly decrease the growth of E. coli at 37°C. E. coli grew optimally at 0.5% (w/v) NaCl concentration. Addition of 0.5% KCl was found to have less beneficial effect on the growth of E. coli at 37°C compared to cells grown in medium with 0.5% NaCl. Increase in the concentrations of both salts above 0.5% decreased growth at 37°C. The extent to which growth was suppressed was directly proportional to the concentration of salts. At zero concentration of both salts, growth of E. coli was very low at 44°C. Increase in the concentrations of both NaCl and KCl from 0.5% to 1.5% resulted in growth enhancement. Glucose affected significantly the growth of E. coli at 37°C. Addition of 140 mM (w/ v) of glucose to the medium increased the growth of E. coli at 37°C to a greater extent than was obtained by salt addition. However, the addition of the same concentration of glucose was found to have only a very slight effect on growth at 44°C.
LanguageEnglish
Pages51-54
Number of pages3
JournalJournal of Food Agriculture and Environment
Volume7
Issue number3-4
Publication statusPublished - Jul 2009

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salt concentration
Salts
Hot Temperature
Escherichia coli
salt
heat
sodium chloride
Growth
glucose
Glucose
salts
effect
potassium chloride
Potassium Chloride
culture media
methodology
Sodium Chloride
cells
incubation

Keywords

  • heat-stressed escherichia coli
  • salt concentration
  • growth

Cite this

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abstract = "The effect sodium chloride (NaCl) and potassium chloride (KCl) concentration on the growth of Escherichia coli cells cultivated at 37 and 44°C was studied in an effort to understand the importance of the salts and glucose in medium to the growth of E. coli. A turbidimetric method was used to measure the growth of E. coli after a 24 hours incubation period. The turbidimetric method used gave a high correlation (R2 = 0.9606) with the traditional surface colony count method. Four sets of salt concentrations, 0, 0.5, 1.0 and 1.5{\%} (w/v), were employed throughout this study. Absence of NaCl in the medium was found to slightly decrease the growth of E. coli at 37°C. E. coli grew optimally at 0.5{\%} (w/v) NaCl concentration. Addition of 0.5{\%} KCl was found to have less beneficial effect on the growth of E. coli at 37°C compared to cells grown in medium with 0.5{\%} NaCl. Increase in the concentrations of both salts above 0.5{\%} decreased growth at 37°C. The extent to which growth was suppressed was directly proportional to the concentration of salts. At zero concentration of both salts, growth of E. coli was very low at 44°C. Increase in the concentrations of both NaCl and KCl from 0.5{\%} to 1.5{\%} resulted in growth enhancement. Glucose affected significantly the growth of E. coli at 37°C. Addition of 140 mM (w/ v) of glucose to the medium increased the growth of E. coli at 37°C to a greater extent than was obtained by salt addition. However, the addition of the same concentration of glucose was found to have only a very slight effect on growth at 44°C.",
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Effect of salt concentrations on the growth of heat-stressed and unstressed escherichia coli. / Abdulkarim, S.M.; Fatimah, A.B.; Anderson, J.G.

In: Journal of Food Agriculture and Environment , Vol. 7, No. 3-4, 07.2009, p. 51-54.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of salt concentrations on the growth of heat-stressed and unstressed escherichia coli

AU - Abdulkarim, S.M.

AU - Fatimah, A.B.

AU - Anderson, J.G.

PY - 2009/7

Y1 - 2009/7

N2 - The effect sodium chloride (NaCl) and potassium chloride (KCl) concentration on the growth of Escherichia coli cells cultivated at 37 and 44°C was studied in an effort to understand the importance of the salts and glucose in medium to the growth of E. coli. A turbidimetric method was used to measure the growth of E. coli after a 24 hours incubation period. The turbidimetric method used gave a high correlation (R2 = 0.9606) with the traditional surface colony count method. Four sets of salt concentrations, 0, 0.5, 1.0 and 1.5% (w/v), were employed throughout this study. Absence of NaCl in the medium was found to slightly decrease the growth of E. coli at 37°C. E. coli grew optimally at 0.5% (w/v) NaCl concentration. Addition of 0.5% KCl was found to have less beneficial effect on the growth of E. coli at 37°C compared to cells grown in medium with 0.5% NaCl. Increase in the concentrations of both salts above 0.5% decreased growth at 37°C. The extent to which growth was suppressed was directly proportional to the concentration of salts. At zero concentration of both salts, growth of E. coli was very low at 44°C. Increase in the concentrations of both NaCl and KCl from 0.5% to 1.5% resulted in growth enhancement. Glucose affected significantly the growth of E. coli at 37°C. Addition of 140 mM (w/ v) of glucose to the medium increased the growth of E. coli at 37°C to a greater extent than was obtained by salt addition. However, the addition of the same concentration of glucose was found to have only a very slight effect on growth at 44°C.

AB - The effect sodium chloride (NaCl) and potassium chloride (KCl) concentration on the growth of Escherichia coli cells cultivated at 37 and 44°C was studied in an effort to understand the importance of the salts and glucose in medium to the growth of E. coli. A turbidimetric method was used to measure the growth of E. coli after a 24 hours incubation period. The turbidimetric method used gave a high correlation (R2 = 0.9606) with the traditional surface colony count method. Four sets of salt concentrations, 0, 0.5, 1.0 and 1.5% (w/v), were employed throughout this study. Absence of NaCl in the medium was found to slightly decrease the growth of E. coli at 37°C. E. coli grew optimally at 0.5% (w/v) NaCl concentration. Addition of 0.5% KCl was found to have less beneficial effect on the growth of E. coli at 37°C compared to cells grown in medium with 0.5% NaCl. Increase in the concentrations of both salts above 0.5% decreased growth at 37°C. The extent to which growth was suppressed was directly proportional to the concentration of salts. At zero concentration of both salts, growth of E. coli was very low at 44°C. Increase in the concentrations of both NaCl and KCl from 0.5% to 1.5% resulted in growth enhancement. Glucose affected significantly the growth of E. coli at 37°C. Addition of 140 mM (w/ v) of glucose to the medium increased the growth of E. coli at 37°C to a greater extent than was obtained by salt addition. However, the addition of the same concentration of glucose was found to have only a very slight effect on growth at 44°C.

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KW - salt concentration

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SP - 51

EP - 54

JO - Journal of Food Agriculture and Environment

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JF - Journal of Food Agriculture and Environment

SN - 1459-0255

IS - 3-4

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