Enterococcus faecium WHE 81, a multi-bacteriocin producer, is effective as an antimicrobial against Listeria monocytogenes in Munster cheese, a red smear soft cheese, according to a French study.
The authors of the study, which was published in the journal Food Microbiology, said that it is well established that soft cheese is amongst the products that pose the highest risk with regard to human listeriosis.
The researchers said that this present study, along with their previous research provides strong evidence that, in case of smear soft cheese, bacteriocin-producing lactic acid bacteria can perform efficiently to control L. monocytogenes when used as surface cultures.
The purpose of the current research, according to the scientists involved, was to investigate the antilisterial effectiveness of E. faecium WHE 81 used as culture for surface smear in Munster cheese.
E. faecium WHE 81, isolated from Munster cheese has been reported to be a reputed multi-bacteriocin producer with up to four independent antimicrobial peptides produced, two of which are enterocins A and B, which are known to be effective antilisterial agents, claims the report.
The researchers said that, during the ripening period, L. monocytogenes rapidly initiated growth in control samples, with counts of approximately 104 CFU g−1 on day 17 and of approximately 105 CFU g−1 on day 21.
Conversely, in the test samples limited increases or no increase at all in L. monocytogenes counts was recorded during the cheese ripening. At the term of the ripening period, L. monocytogenes often remained below enumeration levels and most of the samples analyzed were free from the pathogen, claims the study.
And, according to the published findings, the inoculation of the cheese with E. faecium WHE 81 did not result in any perceivable change in pH, fungal flora or pigmented bacteria in the cheese rind during ripening.
Source: FoodProductionDaily.com