Bactericidal effect of enterocin 4 on Listeria monocytogenes in a model dairy system.
Enterococcus faecalis INIA 4 produced the bacteriocin enterocin 4 during growth in raw ewe's milk at 30 degrees C. Enterocin activity reached 2,200 to 3,600 AU/ml after 8 h, with a 1 to 8% (vol/vol) level of inoculum from an 18-h culture. An enterocin activity of 500 AU/ml significantly decreased counts of Listeria monocytogenes Ohio when incubated for 6 h in a model system consisting of filtrates from cultures of E. faecalis INIA 4 in raw ewe's milk, at pH 6.0 and 30 degrees C. However, an enterocin activity of 2,400 AU/ml was needed in the same conditions to significantly decrease counts of L. monocytogenes Scott A. All 22 wild L. monocytogenes strains isolated from ewe's milk and tested were inhibited by a filtrate containing 400 AU/ml of enterocin 4. Incubation in the filtrate for 6 h significantly lowered counts of 16 L. monocytogenes strains, and incubation for 24 h, counts of 21 strains.
Rodriguez
J L
JL
Departamento de Tecnología de Alimentos, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera de La Coruña Km 7, Madrid, Spain.
Gaya
P
P
Medina
M
M
Nuñez
M
M
D000818:Animals; D000900:Anti-Bacterial Agents / Q000096:biosynthesis / Q000494:pharmacology*; D001426:Bacterial Proteins; D001430:Bacteriocins / Q000096:biosynthesis / Q000494:pharmacology*; D003612:Dairying; D013293:Enterococcus faecalis / Q000254:growth & development / Q000378:metabolism*; D005260:Female; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D008892:Milk / Q000382:microbiology*; D010455:Peptides; D012756:Sheep
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001430:Bacteriocins; D010455:Peptides; C051034:BacA protein, Enterococcus faecalis