Development of a lacticin 3147-enriched whey powder with inhibitory activity against foodborne pathogens.
The broad-spectrum bacteriocin lacticin 3147, produced by Lactococcus lactis DPC3147, is inhibitory to a wide range of gram-positive food spoilage and pathogenic organisms. A 10% solution of demineralized whey powder was fermented with DPC3147 at a constant pH of 6.5. The fermentate was spray dried, and the resulting powder exhibited inhibitory activity. The ability of the lacticin 3147-enriched powder to inhibit Listeria monocytogenes Scott A and Staphylococcus aureus 10 was assessed in buffer at both acidic (pH 5) and neutral (pH 7) pH. In addition, the ability of the powder to inhibit L. monocytogenes Scott A in an infant milk formulation was assessed. Resuspension of approximately 10(8) midexponential phase L. monocytogenes Scott A cells in a 10% solution of the lacticin 3147-enriched powder resulted in a 1,000-fold reduction in viable cells at pH 5 and pH 7 after 3 h at 30 degrees C. In the case of S. aureus 10, resuspension of 2.5 x 10(7) midexponential phase cells in a 15% solution of the lacticin 3147-enriched powder at pH 5 resulted in only a 10-fold reduction in viable cell counts, compared with a 1,000-fold reduction at pH 7, following incubation for 3 h at 30 degrees C. The use of the lacticin 3147 powder in an infant milk formulation resulted in greater than a 99% kill of L. monocytogenes within 3 h at 30 degrees C. These results suggest that this bioactive lacticin 3147 food ingredient may find applications in many different foods, including those with pH close to neutrality.
Morgan
S M
SM
Dairy Products Research Centre, Teasgasc, Moorepark, Fermoy, Co. Cork, Republic of Ireland.
Galvin
M
M
Kelly
J
J
Ross
R P
RP
Hill
C
C
D000818:Animals; D001426:Bacterial Proteins / Q000494:pharmacology; D001430:Bacteriocins / Q000494:pharmacology*; D003470:Culture Media; D005516:Food Microbiology; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000472:pathogenicity; D006863:Hydrogen-Ion Concentration; D008089:Listeria monocytogenes / Q000187:drug effects / Q000472:pathogenicity; D008892:Milk / Q000382:microbiology; D008894:Milk Proteins / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity; D000067816:Whey Proteins
D001426:Bacterial Proteins; D001430:Bacteriocins; D003470:Culture Media; D008894:Milk Proteins; D000067816:Whey Proteins; C082508:lacticin 481