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Table 8 The Effects of pH and heat treatment on antimicrobial activity of potential lactic acid bacteria (LAB) probiotic strains

From: Isolation, characterization, and assessment of lactic acid bacteria toward their selection as poultry probiotics

TreatmentIndicator StrainInhibition zone by
 I2I5I8I13c3c14
UntreatedE. coli+++++++++++++++
E. coli O157: H7++++++++++++
E. faecalis++++++++++++
S. Typhimurium++++++++++
S. Enteritidis++++++++++
L. monocytogenes++++++++++++
NeutralizedE. coli̶̶̶̶+++̶̶̶̶
E. coli O157: H7̶̶̶̶̶̶+̶̶̶̶
E. faecalis̶̶̶̶+++̶̶̶̶
S. Typhimurium̶̶̶̶̶̶+̶̶̶̶
S. Enteritidis̶̶̶̶̶̶+̶̶̶̶
L. monocytogenes̶̶̶̶̶̶̶̶̶̶̶̶
Heat treatedE. coli +++++++++++++++
E. coli O157: H7+++++++++++++
E. faecalis+++++++++++++
S. Typhimurium++++++++++++
S. Enteritidis++++++++++++
L. monocytogenes++++++++++++++
Catalase treatedE. coli +++++++++++++++
E. coli O157: H7++++++++++++
E. faecalis++++++++++++
S. Typhimurium++++++++++
S. Enteritidis++++++++++
L. monocytogenes++++++++++++
  1. Symbols show zones of inhibition (mm): ̶̶, no inhibition; +, weak (< 14); ++, good (15–19); +++, strong (> 20), Neutralized; supernatant treated with 6 N NaOH to obtained a pH 7, heat treated; Supernatants boiled for 10 min, Catalase treated; supernatant treated with 0.5 mg/ml catalase