Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157: H7 cells protected by a biofilm

Nam Hee Kim, Min-Suk Rhee

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22 °C for 6 days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p <0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4%) (p <0.05); indeed, the combination of 0.4% PA plus 3-4% NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a > 6.5 log CFU/cm2 reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7 log CFU/cm2 reduction; NaCl, 2 reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments.

Original languageEnglish
Pages (from-to)17-21
Number of pages5
JournalInternational Journal of Food Microbiology
Volume227
DOIs
Publication statusPublished - 2016 Jun 16

Fingerprint

Phytic Acid
Escherichia coli O157
Biofilms
Sodium chloride
phytic acid
Sodium Chloride
sodium chloride
biofilm
Escherichia coli
Acids
Food processing
Food Handling
cells
food processing
Antimicrobial agents
Food safety
sanitizers
Propidium
antibacterial properties
Food Safety

Keywords

  • Biofilm
  • Control
  • Escherichia coli O157:H7
  • Phytic acid
  • Sodium chloride

ASJC Scopus subject areas

  • Food Science
  • Microbiology
  • Safety, Risk, Reliability and Quality

Cite this

@article{496e62762a904e8cada5bd4a6711b794,
title = "Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157: H7 cells protected by a biofilm",
abstract = "The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22 °C for 6 days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p <0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4{\%}) (p <0.05); indeed, the combination of 0.4{\%} PA plus 3-4{\%} NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a > 6.5 log CFU/cm2 reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7 log CFU/cm2 reduction; NaCl, 2 reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4{\%}) plus NaCl (2-4{\%}) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments.",
keywords = "Biofilm, Control, Escherichia coli O157:H7, Phytic acid, Sodium chloride",
author = "Kim, {Nam Hee} and Min-Suk Rhee",
year = "2016",
month = "6",
day = "16",
doi = "10.1016/j.ijfoodmicro.2016.03.026",
language = "English",
volume = "227",
pages = "17--21",
journal = "International Journal of Food Microbiology",
issn = "0168-1605",
publisher = "Elsevier",

}

TY - JOUR

T1 - Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157

T2 - H7 cells protected by a biofilm

AU - Kim, Nam Hee

AU - Rhee, Min-Suk

PY - 2016/6/16

Y1 - 2016/6/16

N2 - The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22 °C for 6 days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p <0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4%) (p <0.05); indeed, the combination of 0.4% PA plus 3-4% NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a > 6.5 log CFU/cm2 reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7 log CFU/cm2 reduction; NaCl, 2 reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments.

AB - The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22 °C for 6 days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p <0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4%) (p <0.05); indeed, the combination of 0.4% PA plus 3-4% NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a > 6.5 log CFU/cm2 reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7 log CFU/cm2 reduction; NaCl, 2 reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments.

KW - Biofilm

KW - Control

KW - Escherichia coli O157:H7

KW - Phytic acid

KW - Sodium chloride

UR - http://www.scopus.com/inward/record.url?scp=84961878063&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84961878063&partnerID=8YFLogxK

U2 - 10.1016/j.ijfoodmicro.2016.03.026

DO - 10.1016/j.ijfoodmicro.2016.03.026

M3 - Article

C2 - 27043385

AN - SCOPUS:84961878063

VL - 227

SP - 17

EP - 21

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

ER -