Inhibition of Listeria monocytogenes by enterocin 4 during the manufacture and ripening of Manchego cheese.
The inhibitory effect of enterocin 4, a bacteriocin produced by Enterococcus faecalis INIA 4, on Listeria monocytogenes strains Ohio and Scott A during the manufacture and ripening of Manchego cheese was investigated. Raw ewe's milk was inoculated with ca 10(5) cfu ml-1 of L. monocytogenes and with 1% of a commercial lactic starter, 1% of an Ent. faecalis INIA 4 culture, or 1% of each culture. Manchego cheeses were manufactured according to usual procedures. Listeria monocytogenes Ohio counts decreased by 3 log units after 8 h and by 6 log units after 7 d in cheese made from milk inoculated with Ent. faecalis INIA 4 or with both cultures, whereas no inhibition was recorded after 60 d in cheese made from milk inoculated with commercial lactic starter. Listeria monocytogenes Scott A was not inhibited by enterocin 4 during cheese manufacture, but decreases of 1 log unit after 7 d and of 2 log units after 60 d were achieved in cheese made from milk inoculated with both commercial lactic starter and Ent. faecalis INIA 4.
Nuñez
M
M
Departamento de Tecnología de Alimentos, CIT-INIA, Madrid, Spain.
Rodríguez
J L
JL
García
E
E
Gaya
P
P
Medina
M
M
D001430:Bacteriocins / Q000494:pharmacology*; D002611:Cheese / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects*
D001430:Bacteriocins