Behaviour of Listeria monocytogenes during the maturation of naturally and artificially contaminated salami: effect of lactic-acid bacteria starter cultures.
The antimicrobial activity of a bacteriocin-producing Lactobacillus plantarum MCS strain against Listeria monocytogenes in naturally and artificially contaminated salami was evaluated in comparison with that of other non bacteriocin-producing lactic-acid bacteria (i.e., L. plantarum MCS1 mutant strain and two commercial starter cultures). In salami not inoculated with lactic-acid bacteria, moderate L. monocytogenes growth was observed after 7-14 days. The addition of the starter cultures prevented growth, but not always the survival of Listeria. During the maturation of artificially-contaminated salami, Listeria counts tended to decrease, but no significant differences were observed between samples inoculated with L. plantarum MCS or with the MCS1 bacteriocin-negative mutant strain. However, at the end of the maturation period, in naturally-contaminated salami, differences in the survival of Listeria (recovered by enrichment) were observed in the batches inoculated with the different lactic-acid bacteria: Listeria appeared to be absent only in salami inoculated with the L. plantarum MCS strain.
Campanini
M
M
Stazione Sperimentale per l'Industria delle Conserve Alimentari, Parma, Italy.
Pedrazzoni
I
I
Barbuti
S
S
Baldini
P
P
D001430:Bacteriocins / Q000096:biosynthesis / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007778:Lactobacillus / Q000378:metabolism / Q000502:physiology*; D008089:Listeria monocytogenes / Q000254:growth & development*; D008461:Meat Products / Q000382:microbiology*
D001430:Bacteriocins