Altered ability of Bacillus cereus spores to grow under unfavorable conditions (presence of nisin, low temperature, acidic pH, presence of NaCl) following heat treatment during sporulation.
The effect of thermal treatment on the heat resistance of Bacillus cereus spores and their ability to germinate and grow under more or less adverse conditions during sporulation was investigated. Spores produced by sporulating cells subjected to a mild heat treatment (at a temperature 15 degrees C higher than the growth temperature) were more resistant to heat than were spores produced by untreated cells. Spore germination and growth (the lag time, the maximal growth rate, and the occurrence of a decrease in population) may be greatly affected by adverse environmental conditions brought about by the addition of nisin, low temperatures, acidic pHs, and, to a lesser extent, the addition of NaCl. Furthermore, heat treatments applied to sporulating cells or to mature spores induced a modification of the lag time (interaction of both treatments). Therefore, mild heat treatments applied during sporulation may affect the heat resistance of spores and the ability of these spores to germinate under adverse conditions and may thus increase the risk associated with the presence of spores in lightly processed foods.
Faille
Christine
C
Institut National de la Recherche Agronomique, Laboratoire de Geénie des Procédés et Technologie Alimentaires, Rue Jules Guesde, B.P.39, F-59651 Villeneuve d'Ascq cedex, France. faille@lille.inra.fr
Membre
Jeanne Marie
JM
Kubaczka
Martine
M
Gavini
Françoise
F
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001409:Bacillus cereus / Q000254:growth & development* / Q000502:physiology*; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009561:Nisin / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013171:Spores, Bacterial / Q000254:growth & development / Q000502:physiology*; D013997:Time Factors
D000900:Anti-Bacterial Agents; D009561:Nisin; D012965:Sodium Chloride