Thermal inactivation of Bacillus cereus spores formed at different temperatures

Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods

“…The thermal inactivation pattern of spores of B. cereus cultures observed in most of the earlier studies have revealed that D-values differ very much depending primarily on the strains used and to a lesser extent the extrinsic and intrinsic factors. Earlier studies have reported varying D-values for ATCC strains of B. cereus 4342, 7004 and 9818 in buffers and substrates similar to culture broth and those containing food constituents (Mazas et al 1995(Mazas et al , 1999aGonzález et al 1999;Montville et al 2005;Moussa-Boudjemma et al 2006). A similar situation was also reported for a strain of Bacillus anthracis Sterne (Novak et al 2005).…”

“…Although pasteurization is known to inactivate the vegetative cells, spores of B. cereus are known to be highly heat resistant and are usually unaffected by physical, chemical and biological factors (Gaillard et al 1998;González et al 1999). In general, investigations have addressed these aspects relating to either vegetative cells or spores and not both the phases together of one and the same species, except for a not very recent study (Byrne et al 2006).…”

Growth and Sporulation of Bacillus cereus ATCC 14579 under Defined Conditions: Temporal Expression of Genes for Key Sigma Factors

“…It has been well established that bacterial spore properties are affected by the conditions during sporulation (2,11,12,23,33), but in most studies spores are routinely produced from fortified agar or rich liquid media, which results in heterogeneous sporulation conditions for the individual cells. Homogeneous sporulation conditions and precise regulation of growth and sporulation parameters are of great importance for obtaining reproducible and homogeneous spore batches.…”

Bacillus cereus growth and biofilm formation: the impact of substratum, iron sources, and transcriptional regulator Sigma 54

“…Heat resistance properties of spores are of key importance to their survival of food processing and the impact on quality and safety issues. Extrinsic factors such as medium composition, sporulation temperature and water activity may influence spore properties (Gaillard et al 1998, González et al 1999, Palop et al 1999. The sporulation response to environmental conditions is species and strain specific (Mazas et al 1995, González et al 1999, sometimes even displaying opposite responses for the same factor, as reported for spores of different Bacillus species formed in rich and poor sporulation media (Baril et al 2012).…”

“…Extrinsic factors such as sporulation conditions affect spore properties to a lesser degree. Sporulation temperature has a large effect on spore heat resistance of B. cereus with a 10 fold difference in decimal reduction time (D 100°C ) for spores formed at 20 compared to 45⁰C (González et al 1999). Most studies show lower impact of different factors such as sporulation medium, level of nutrients or pH on spore heat resistance, reporting between 1.3 to 6 fold changes in decimal reduction values (D-values) (Mazas et al 1995, Baweja et al 2008, Baril et al 2012).…”