TY - JOUR
T1 - Inactivation of Escherichia coli O157
T2 - H7 on stainless steel upon exposure to Paenibacillus polymyxa biofilms
AU - Kim, Seonhwa
AU - Bang, Jihyun
AU - Kim, Hoikyung
AU - Beuchat, Larry R.
AU - Ryu, Jee Hoon
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MEST) (No. 2009-0069681 ). We thank the Korea University Food Safety Center and the Institute of Food and Biomedicine Safety for providing equipment and facilities.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2013/11/1
Y1 - 2013/11/1
N2 - We investigated the potential use of biofilm formed by a competitive-exclusion (CE) microorganism to inactivate Escherichia coli O157:H7 on a stainless steel surface. Five microorganisms showing inhibitory activities against E. coli O157:H7 were isolated from vegetable seeds and sprouts. The microorganism with the greatest antimicrobial activity was identified as Paenibacillus polymyxa (strain T5). In tryptic soy broth (TSB), strain T5 reached a higher population at 25. °C than at 12 or 37. °C without losing inhibitory activity against E. coli O157:H7. When P. polymyxa (6. log. CFU/mL) was co-cultured with E. coli O157:H7 (2, 3, 4, or 5. log. CFU/mL) in TSB at 25. °C, the number of E. coli O157:H7 decreased significantly within 24. h. P. polymyxa formed a biofilm on stainless steel coupons (SSCs) in TSB at 25. °C within 24. h, and cells in biofilms, compared to attached cells without biofilm formation, showed significantly increased resistance to a dry environment (43% relative humidity [RH]). With the exception of an inoculum of 4. log. CFU/coupon at 100% RH, upon exposure to biofilm formed by P. polymyxa on SSCs, populations of E. coli O157:H7 (2, 4, or 6. log. CFU/coupon) were significantly reduced within 48. h. Most notably, when E. coli O157:H7 at 2. log. CFU/coupon was applied to SSCs on which P. polymyxa biofilm had formed, it was inactivated within 1. h, regardless of RH. These results will be useful when developing strategies using biofilms produced by competitive exclusion microorganisms to inactivate foodborne pathogens in food processing environments.
AB - We investigated the potential use of biofilm formed by a competitive-exclusion (CE) microorganism to inactivate Escherichia coli O157:H7 on a stainless steel surface. Five microorganisms showing inhibitory activities against E. coli O157:H7 were isolated from vegetable seeds and sprouts. The microorganism with the greatest antimicrobial activity was identified as Paenibacillus polymyxa (strain T5). In tryptic soy broth (TSB), strain T5 reached a higher population at 25. °C than at 12 or 37. °C without losing inhibitory activity against E. coli O157:H7. When P. polymyxa (6. log. CFU/mL) was co-cultured with E. coli O157:H7 (2, 3, 4, or 5. log. CFU/mL) in TSB at 25. °C, the number of E. coli O157:H7 decreased significantly within 24. h. P. polymyxa formed a biofilm on stainless steel coupons (SSCs) in TSB at 25. °C within 24. h, and cells in biofilms, compared to attached cells without biofilm formation, showed significantly increased resistance to a dry environment (43% relative humidity [RH]). With the exception of an inoculum of 4. log. CFU/coupon at 100% RH, upon exposure to biofilm formed by P. polymyxa on SSCs, populations of E. coli O157:H7 (2, 4, or 6. log. CFU/coupon) were significantly reduced within 48. h. Most notably, when E. coli O157:H7 at 2. log. CFU/coupon was applied to SSCs on which P. polymyxa biofilm had formed, it was inactivated within 1. h, regardless of RH. These results will be useful when developing strategies using biofilms produced by competitive exclusion microorganisms to inactivate foodborne pathogens in food processing environments.
KW - Biofilm
KW - Competitive-exclusion
KW - Escherichia coli O157:H7
KW - Paenibacillus polymyxa
KW - Stainless steel surface
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U2 - 10.1016/j.ijfoodmicro.2013.10.004
DO - 10.1016/j.ijfoodmicro.2013.10.004
M3 - Article
C2 - 24184611
AN - SCOPUS:84886520330
VL - 167
SP - 328
EP - 336
JO - International Journal of Food Microbiology
JF - International Journal of Food Microbiology
SN - 0168-1605
IS - 3
ER -