Joint effect of nisin, CO2, and EDTA on the survival of Pseudomonas aeruginosa and Enterococcus faecium in a food model system.
A study on the joint effect of either nisin or Nisaplin, headspace CO2 levels, and EDTA on the survival of Pseudomonas aeruginosa and Enterococcus faecium was carried out in a water-soluble fish muscle extract at 3 degrees C using a second-order rotatable factorial design. E. faecium was completely deactivated by all processing after 2 days of storage. In contrast, P. aeruginosa was much less susceptible to treatments, and cell death was satisfactorily described by two models. Nisin increased cell death, whereas Nisaplin (commercial form of nisin) was not suitable, as it caused undesirable interference, presumably due to its co-compounds. Interactions between Nisaplin or nisin and either EDTA or CO2 were found to be nonstatistically significant. Factors that could account for this unexpected lack of synergism are discussed. However, a statistically significant positive interaction was found between CO2 and EDTA. This finding could allow CO2 levels to be decreased and hence to reduce the main disadvantages of CO2 application, namely, exudation and acidification.
Cabo
M L
ML
Instituto de Investigacións Mariñas (CSIC), Vigo, Pontevedra, Spain. marta@iim.csic.es
Pastoriza
L
L
Sampedro
G
G
González
M P
MP
Murado
M A
MA
D000818:Animals; D000900:Anti-Bacterial Agents; D002245:Carbon Dioxide / Q000494:pharmacology*; D004357:Drug Synergism; D004492:Edetic Acid / Q000494:pharmacology*; D016984:Enterococcus faecium / Q000187:drug effects / Q000254:growth & development*; D005503:Food Additives; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods; D008954:Models, Biological; D009561:Nisin / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development*; D017747:Seafood / Q000382:microbiology*
D000900:Anti-Bacterial Agents; D005503:Food Additives; D009561:Nisin; D002245:Carbon Dioxide; D004492:Edetic Acid