Thermal inactivation parameters of spores from different phylogenetic groups of Bacillus cereus

Characterization of Bacillus cereus spores isolated from Algerian processed cheese

“…cereus Z value varies from 8 to 12.5°C, according to ANSES (2011); from 8 to 8.6°C according to Byrne et al, (2006) and from 6.7 to 10.1°C, according to Caudrillier (2008). Mayoraz (2006) reported a 15°C Z value, while characteristic group III ZT values are 8.4°C, according to Luu-Thi et al (2014).…”

Impact of microbial variability on food safety and quality

“…Besides strain variability, growth conditions, such as intrinsic and extrinsic parameters of the media, including pH, water activity, temperature, organic acid concentration and type of solute used to lower water activity, were also reported to affect the variability in microbial growth limit Van der Veen et al, 2008). Similar to growth kinetics, the influence of strain variability was also reported for thermal inactivation kinetics of vegetative cells Mackey et al, 1990;Sörqvist, 1994) and spores (Berendsen et al, 2015;Luu-Thi et al, 2014). The effect of each reported influential factor on D-values was analysed in a previous study with a systematic approach to determine global thermal inactivation parameters for various food pathogens .…”

“…Similarly to growth kinetics, strain variability in thermal inactivation kinetics has also been studied for vegetative cells De Jesús and Whiting, 2003;Mackey et al, 1990;Ng et al, 1969;Sörqvist, 1994;Whiting and Golden, 2002) and spores (Berendsen et al, 2015;Luu-Thi et al, 2014). Although differences between strains were reported, strain variability was suggested to be more or less similar to within strain (reproduction) variability in previous studies using L. monocytogenes and Salmonella (De Jesús and Whiting, 2003;.…”

“…In both studies however, the factors reported to influence the D-value were smaller than the variability of all published data, except for the effect of high salt concentration. To date, several studies have focused on investigating the effect of strain variability on thermal resistance of vegetative cells De Jesús and Whiting, 2003;Mackey et al, 1990;Ng et al, 1969;Sörqvist, 1994) and spores (Berendsen et al, 2014;Luu-Thi et al, 2014). However, the results between studies, even those using the same species, were different.…”

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

“…The functions of genes carried on this transposon (SpoVAC, SpoVAD, SpoVAEb and four other unknown genes) are not completely known but the presence of the transposon results in about 50 % higher dipicolinic acid (DPA) content (Berendsen et al 2016). B. cereus strains belonging to various phylogenetic groups displayed lower variability in their heat resistance, having D 95°C values between 2 and 30 min, excluding psychrotolerant strains with low heat resistance (Luu-Thi et al 2014). Extrinsic factors such as sporulation conditions affect spore properties to a lesser degree.…”