Suppression of Listeria monocytogenes Scott A in Fluid Milk by Free and Liposome-Entrapped Nisin. Academic Article uri icon

abstract

  • Nisin is an antimicrobial polypeptide inhibitory toward Gram-positive bacterial pathogens, including Listeria monocytogenes. Encapsulating nisin in lipid nanocapsules (i.e., liposomes) has been shown to protect antimicrobial functionality in complex food matrices. The capacity of liposomes to encapsulate a fluorescent reporter was determined via spectroscopy. Survival and growth of L. monocytogenes incubated in fluid milk containing 50IU/ml free or liposome-entrapped nisin was assayed via periodic enumeration of survivors. Liposomes were formulated from phosphatidylcholine (PC) and phosphatidyl-DL-glycerol (PG) and prepared as PC, PC/PG 7/3 or PC/PG 6/4 (mol. fraction). Antilisterial activity of nisin-loaded liposomes was determined in ultra-high temperature processed fluid milk containing approximately 4.0 log10CFU/ml L. monocytogenes Scott A plus liposomal or free nisin at 50IU/mL. Samples were aerobically held at 5 or 20C; L. monocytogenes were enumerated via plating after 0, 1, 3, 6, 12, 24, 48, and 72 incubation hours. Liposome entrapment did not enhance pathogen inhibition when compared to free nisin as a function of storage temperature or incubation duration.

published proceedings

  • Probiotics Antimicrob Proteins

author list (cited authors)

  • Schmidt, S. E., Holub, G., Sturino, J. M., & Matthew Taylor, T.

citation count

  • 17

complete list of authors

  • Schmidt, Shannon E||Holub, Glenn||Sturino, Joseph M||Matthew Taylor, T

publication date

  • December 2009