Article Abstract:
The role of pediocin production in Pediococcus starter cultures used to control Listeria monocytogenes in turkey summer sausage was determined. The experiments assessed the efficiency of non-pediocin-producing mutants versus the pediocin-producing cultures. The results showed that pediocin-producing starter cultures are associated with more dramatic reduction in counts of L. monocytogenes during fermentation. Further analysis showed that P. acidilactici starter cultures and pediocin-encoding plasmids are genetically related. Not all of the commercially available starter cultures encode pediocin or are equally effective in controlling L. monocytogenes.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
The effects of varying the pH and the sodium chloride (NaCl) concentration on the survival and growth of Escherichia coli O157:H7 in broth was determined. Media with 6.5% or less NaCl or a pH of 4.5 to 9.0 adjusted with hydrochloric acid were conducive to growth. When lactic acid was used to adjust pH, the organism grew at 4.6 but not at 4.5. Commercial sausage batter was inoculated with the E. coli strain, fermented to pH 4.8 and dried, then stored frozen for two months. The E. coli survived after processing but did not grow, and its population decreased after the storage period.
User Contributions:
Comment about this article or add new information about this topic:
Article Abstract:
A study was conducted to analyze the efficacy of Lactococcus lactis subsp. lactis MM217 for controlling L. monocytogenes during the manufacture and ripening of Cheddar cheese. Results indicated that a genetically modified starter culture support pediocin in situ enhanced the microbiological safety of Cheddar cheese contaminated with L. monocytogenes. Findings also showed the declines in pediocin production correlated with the depletion of carbon and energy sources.
User Contributions:
Comment about this article or add new information about this topic: