Inhibition of Listeria monocytogenes by freeze-dried piscicocin CS526 fermentate in food.
OBJECTIVE
The effectiveness of freeze-dried powder, fermented with bacteriocin producing Carnobacterium piscicola CS526, was evaluated for the inhibition of Listeria monocytogenes in a food model.


RESULTS
A 10% solution of milk whey powder was fermented with a bacteriocinogenic C. piscicola CS526 Bac(+) or its nonbacteriocinogenic mutant strain CS526 Bac(-) at 30 degrees C for 12 h and freeze-dried. The freeze-dried piscicocin CS526 Bac(+) fermentate exhibited strong anti-listerial activity even at a concentration of 1% (w/v) in sterile water (pH 7), but the piscicocin CS526 Bac(-) fermentate and nonfermented whey powder had no anti-listerial activity. In the presence of 10% piscicocin CS526 Bac(+) fermentate, L. monocytogenes in ground meat rapidly decreased from 10(5) CFU g(-1) to less than the detection limit (3.0 x 10(3) CFU g(-1)) within 5 and 1 days at 4 and 12 degrees C, and was bacteriostatically inhibited for 25 and 4 days at 4 and 12 degrees C respectively. Furthermore, this inhibitory effect was enhanced at lower temperatures.


CONCLUSIONS
Piscicocin CS526 Bac(+) fermentate was effective for the control of L. monocytogenes in a food model at refrigeration temperatures.


CONCLUSIONS
A freeze-dried bioactive piscicocin CS526 Bac(+) powder can be a powerful tool to ensure food safety against L. monocytogenes contamination in refrigerated foods such as ready-to-eat products.
Azuma
T
T
Laboratory of Food Safety, Faculty of Fisheries Sciences, Hokkaido University, Hakodate 041-8611, Japan.
Bagenda
D K
DK
Yamamoto
T
T
Kawai
Y
Y
Yamazaki
K
K
D001430:Bacteriocins / Q000494:pharmacology*; D005285:Fermentation; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D005612:Freeze Drying; D008089:Listeria monocytogenes / Q000187:drug effects*
D001430:Bacteriocins